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Sample records for 30s 31cl deduced

  1. Mass of astrophysically relevant 31Cl and the breakdown of the isobaric multiplet mass equation

    NASA Astrophysics Data System (ADS)

    Kankainen, A.; Canete, L.; Eronen, T.; Hakala, J.; Jokinen, A.; Koponen, J.; Moore, I. D.; Nesterenko, D.; Reinikainen, J.; Rinta-Antila, S.; Voss, A.; ńystö, J.

    2016-04-01

    The mass of 31Cl has been measured with the JYFLTRAP double-Penning-trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility. The determined mass-excess value, -7034.7 (34 ) keV, is 15 times more precise than in the Atomic Mass Evaluation 2012. The quadratic form of the isobaric multiplet mass equation for the T =3 /2 quartet at A =31 fails (χn2=11.6 ) and a nonzero cubic term, d =-3.5 (11 ) keV, is obtained when the new mass value is adopted. 31Cl has been found to be less proton-bound, with a proton separation energy of Sp=264.6 (34 ) keV. Energies for the excited states in 31Cl and the photodisintegration rate on 31Cl have been determined with significantly improved precision by using the new Sp value. The improved photodisintegration rate helps to constrain astrophysical conditions where 30S can act as a waiting point in the rapid proton capture process in type-I x-ray bursts.

  2. A dye-sensitized visible light photocatalyst-Bi24O31Cl10

    PubMed Central

    Wang, Liang; Shang, Jun; Hao, Weichang; Jiang, Shiqi; Huang, Shiheng; Wang, Tianmin; Sun, Ziqi; Du, Yi; Dou, Shixue; Xie, Tengfeng; Wang, Dejun; Wang, Jiaou

    2014-01-01

    The p-block semiconductors are regarded as a new family of visible-light photocatalysts because of their dispersive and anisotropic band structures as well as high chemical stability. The bismuth oxide halides belong to this family and have band structures and dispersion relations that can be engineered by modulating the stoichiometry of the halogen elements. Herein, we have developed a new visible-light photocatalyst Bi24O31Cl10 by band engineering, which shows high dye-sensitized photocatalytic activity. Density functional theory calculations reveal that the p-block elements determine the nature of the dispersive electronic structures and narrow band gap in Bi24O31Cl10. Bi24O31Cl10 exhibits excellent visible-light photocatalytic activity towards the degradation of Rhodamine B, which is promoted by dye sensitization due to compatible energy levels and high electronic mobility. In addition, Bi24O31Cl10 is also a suitable photoanode material for dye-sensitized solar cells and shows power conversion efficiency of 1.5%. PMID:25488704

  3. A dye-sensitized visible light photocatalyst-Bi24O31Cl10.

    PubMed

    Wang, Liang; Shang, Jun; Hao, Weichang; Jiang, Shiqi; Huang, Shiheng; Wang, Tianmin; Sun, Ziqi; Du, Yi; Dou, Shixue; Xie, Tengfeng; Wang, Dejun; Wang, Jiaou

    2014-01-01

    The p-block semiconductors are regarded as a new family of visible-light photocatalysts because of their dispersive and anisotropic band structures as well as high chemical stability. The bismuth oxide halides belong to this family and have band structures and dispersion relations that can be engineered by modulating the stoichiometry of the halogen elements. Herein, we have developed a new visible-light photocatalyst Bi24O31Cl10 by band engineering, which shows high dye-sensitized photocatalytic activity. Density functional theory calculations reveal that the p-block elements determine the nature of the dispersive electronic structures and narrow band gap in Bi24O31Cl10. Bi24O31Cl10 exhibits excellent visible-light photocatalytic activity towards the degradation of Rhodamine B, which is promoted by dye sensitization due to compatible energy levels and high electronic mobility. In addition, Bi24O31Cl10 is also a suitable photoanode material for dye-sensitized solar cells and shows power conversion efficiency of 1.5%. PMID:25488704

  4. 31Cl beta decay and the 30P31S reaction rate in nova nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Bennett, Michael; Wrede, C.; Brown, B. A.; Liddick, S. N.; Pérez-Loureiro, D.; NSCL e12028 Collaboration

    2016-03-01

    The 30P31S reaction rate is critical for modeling the final isotopic abundances of ONe nova nucleosynthesis, identifying the origin of presolar nova grains, and calibrating proposed nova thermometers. Unfortunately, this rate is essentially experimentally unconstrained because the strengths of key 31S proton capture resonances are not known, due to uncertainties in their spins and parities. Using a 31Cl beam produced at the National Superconducting Cyclotron Laboratory, we have populated several 31S states for study via beta decay and devised a new decay scheme which includes updated beta feedings and gamma branchings as well as multiple states previously unobserved in 31Cl beta decay. Results of this study, including the unambiguous identification due to isospin mixing of a new l = 0 , Jπ = 3 /2+ 31S resonance directly in the middle of the Gamow Window, will be presented, and significance to the evaluation of the 30P31S reaction rate will be discussed. Work supported by U.S. Natl. Sci. Foundation (Grants No. PHY-1102511, PHY-1404442, PHY-1419765, and PHY-1431052); U.S. Dept. of Energy, Natl. Nucl. Security Administration (Award No. DE-NA0000979); Nat. Sci. and Eng. Research Council of Canada.

  5. Constructing Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing route for achieving enhanced photocatalytic activity and selectivity

    PubMed Central

    Liu, Xiaoyan; Su, Yiguo; Zhao, Qihang; Du, Chunfang; Liu, Zhiliang

    2016-01-01

    This work reports on the construction of a Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing method. The X-ray diffraction (XRD) results indicated that the phase transformation from BiOCl to Bi24O31Cl10 could be realized during the thermal annealing process. The high-resolution transmission electron microscopy (HRTEM) images, X-ray photoelectron spectroscopy (XPS) binding energy shifts, Raman spectra and Fouier transform infrared spectroscopy (FT-IR) spectra confirmed the formation of the Bi24O31Cl10/BiOCl heterojunction. The obtained Bi24O31Cl10/BiOCl photocatalyst showed excellent conversion efficiency and selectivity toward photocatalytic conversion of benzyl alcohol to benzaldehyde under visible light irradiation. The radical scavengers and electron spin resonance (ESR) results suggested that the photogenerated holes were the dominant reactive species responsible for the photocatalytic oxidation of benzyl alcohol and superoxide radicals were not involved in the photocatalytic process. The in-situ generation of Bi24O31Cl10/BiOCl heterojunction may own superior interfacial contact than the two-step synthesized heterojunctions, which promotes the transfer of photogenerated charge carriers and is favorable for excellent photocatalytic activities. PMID:27340032

  6. Constructing Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing route for achieving enhanced photocatalytic activity and selectivity

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoyan; Su, Yiguo; Zhao, Qihang; Du, Chunfang; Liu, Zhiliang

    2016-06-01

    This work reports on the construction of a Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing method. The X-ray diffraction (XRD) results indicated that the phase transformation from BiOCl to Bi24O31Cl10 could be realized during the thermal annealing process. The high-resolution transmission electron microscopy (HRTEM) images, X-ray photoelectron spectroscopy (XPS) binding energy shifts, Raman spectra and Fouier transform infrared spectroscopy (FT-IR) spectra confirmed the formation of the Bi24O31Cl10/BiOCl heterojunction. The obtained Bi24O31Cl10/BiOCl photocatalyst showed excellent conversion efficiency and selectivity toward photocatalytic conversion of benzyl alcohol to benzaldehyde under visible light irradiation. The radical scavengers and electron spin resonance (ESR) results suggested that the photogenerated holes were the dominant reactive species responsible for the photocatalytic oxidation of benzyl alcohol and superoxide radicals were not involved in the photocatalytic process. The in-situ generation of Bi24O31Cl10/BiOCl heterojunction may own superior interfacial contact than the two-step synthesized heterojunctions, which promotes the transfer of photogenerated charge carriers and is favorable for excellent photocatalytic activities.

  7. Constructing Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing route for achieving enhanced photocatalytic activity and selectivity.

    PubMed

    Liu, Xiaoyan; Su, Yiguo; Zhao, Qihang; Du, Chunfang; Liu, Zhiliang

    2016-01-01

    This work reports on the construction of a Bi24O31Cl10/BiOCl heterojunction via a simple thermal annealing method. The X-ray diffraction (XRD) results indicated that the phase transformation from BiOCl to Bi24O31Cl10 could be realized during the thermal annealing process. The high-resolution transmission electron microscopy (HRTEM) images, X-ray photoelectron spectroscopy (XPS) binding energy shifts, Raman spectra and Fouier transform infrared spectroscopy (FT-IR) spectra confirmed the formation of the Bi24O31Cl10/BiOCl heterojunction. The obtained Bi24O31Cl10/BiOCl photocatalyst showed excellent conversion efficiency and selectivity toward photocatalytic conversion of benzyl alcohol to benzaldehyde under visible light irradiation. The radical scavengers and electron spin resonance (ESR) results suggested that the photogenerated holes were the dominant reactive species responsible for the photocatalytic oxidation of benzyl alcohol and superoxide radicals were not involved in the photocatalytic process. The in-situ generation of Bi24O31Cl10/BiOCl heterojunction may own superior interfacial contact than the two-step synthesized heterojunctions, which promotes the transfer of photogenerated charge carriers and is favorable for excellent photocatalytic activities. PMID:27340032

  8. Study of excited states of {sup 31}S through beta-decay of {sup 31}Cl for nucleosynthesis in ONe novae

    SciTech Connect

    Saastamoinen, A.; Jokinen, A.; Aeystoe, J.; Trache, L.; Hardy, J. C.; Iacob, V. E.; McCleskey, M.; Roeder, B.; Simmons, E.; Tabacaru, G.; Tribble, R. E.; Banu, A.; Bentley, M. A.; Davinson, T.; Woods, P. J.

    2011-11-30

    We have produced an intense and pure beam of {sup 31}Cl with the MARS Separator at the Texas A and M University and studied {beta}-decay of {sup 31}Cl by implanting the beam into a novel detector setup, capable of measuring {beta}-delayed protons and {gamma}-rays simultaneously. From our data, we have established decay scheme of {sup 31}Cl, found resonance energies with 1 keV precision, have measured its half-life with under 1% accuracy, found its Isobar Analog State decay and by using the IMME obtained an improved mass excess for its ground state. In this contribution, a description of the used method along with selected preliminary experimental results are given and their relevance for novae nucleosynthesis discussed.

  9. Beta-decay of 31Cl: an indirect probe of the 30P(p,γ)31S reaction. Present status and future perspectives

    NASA Astrophysics Data System (ADS)

    Saastamoinen, Antti; Kankainen, Anu; Trache, Livius

    2016-08-01

    β-decay of 31Cl can be used as a selective tool for studying astrophysically relevant states in 31S. In this article we review the present status of the decay data. The implications for the 30P(p,γ)31S reaction rate at novae temperatures, and future experimental ideas are discussed.

  10. Nuclear structure of 30S and its implications for nucleosynthesis in classical novae

    NASA Astrophysics Data System (ADS)

    Setoodehnia, K.; Chen, A. A.; Kahl, D.; Komatsubara, T.; José, J.; Longland, R.; Abe, Y.; Binh, D. N.; Chen, J.; Cherubini, S.; Clark, J. A.; Deibel, C. M.; Fukuoka, S.; Hashimoto, T.; Hayakawa, T.; Hendriks, J.; Ishibashi, Y.; Ito, Y.; Kubono, S.; Lennard, W. N.; Moriguchi, T.; Nagae, D.; Nishikiori, R.; Niwa, T.; Ozawa, A.; Parker, P. D.; Seiler, D.; Shizuma, T.; Suzuki, H.; Wrede, C.; Yamaguchi, H.; Yuasa, T.

    2013-06-01

    Background: The uncertainty in the 29P(p,γ)30S reaction rate over 0.1 ≤ T ≤ 1.3 GK was previously determined to span approximately four orders of magnitude due to the uncertain location of two previously unobserved 3+ and 2+ resonances in the Ex=4.7-4.8 MeV region in 30S. Therefore, the abundances of silicon isotopes synthesized in novae, which are relevant for the identification of presolar grains of putative nova origin, were uncertain by a factor of 3.Purpose: (a) To investigate the level structure of 30S above the proton threshold [4394.9(7) keV] via charged-particle spectroscopy using the 32S(p,t)30S reaction and in-beam γ-ray spectroscopy using the 28Si(3He, nγ)30S reaction to calculate the 29P(p,γ)30S reaction rate. (b) To explore the impact of this rate on the abundances of silicon isotopes synthesized in novae.Methods: Differential cross sections of the 32S(p,t)30S reaction were measured at 34.5 MeV. Distorted-wave Born approximation calculations were performed to constrain the spin-parity assignments of the observed levels, including the two astrophysically important levels. An energy-level scheme was deduced from γ-γ coincidence measurements using the 28Si(3He, nγ)30S reaction. Spin-parity assignments based on measurements of γ-ray angular distributions and γ-γ directional correlation from oriented nuclei were made for most of the observed levels of 30S.Results: The resonance energies corresponding to the states with 4.5 MeV ≲ Ex ≲ 6 MeV, including the two astrophysically important states predicted previously, are measured with significantly better precision than before. The spin-parity assignments of both astrophysically important resonances are confirmed. The uncertainty in the rate of the 29P(p,γ)30S reaction is substantially reduced over the temperature range of interest. Finally, the influence of this rate on the abundance ratios of silicon isotopes synthesized in novae are obtained via 1D hydrodynamic nova simulations

  11. {sup 30}S Beam Development and X-ray Bursts

    SciTech Connect

    Kahl, D.; Kubono, S.; Binh, D. N.; Hashimoto, T.; Hayakawa, S.; Kurihara, Y.; Ohshiro, Y.; Yamaguchi, H.; Chen, A. A.; Chen, J.; Setoodeh nia, K.; Kaji, D.; Nishimura, S.; Kim, A.; Lee, N. H.; Wakabayashi, Y.

    2010-03-01

    Over the past three years, we have worked on developing a well-characterized {sup 30}S radioactive beam to be used in a future experiment aiming to directly measure to extrapolate the {sup 30}S(alpha,p) stellar reaction rate within the Gamow window of Type I X-ray bursts. The importance of the {sup 30}S(alpha,p) reaction to X-ray bursts is discussed. Given the astrophysical motivation, the successful results of and challenges involved in the production of a low-energy {sup 30}S beam are detailed. Finally, an overview of our future plans regarding this on-going project are presented.

  12. Photoluminescence and photocatalytic properties of BiOCl and Bi{sub 24}O{sub 31}Cl{sub 10} nanostructures synthesized by electrolytic corrosion of metal Bi

    SciTech Connect

    Chen, G.; Fang, G.L.; Tang, G.D.

    2013-03-15

    Highlights: ► We report a facile method to synthesize bismuth oxychlorides. ► The BiOCl nanosheets have both ultraviolet-blue emission zone and visible emission zone. ► The Bi{sub 24}O{sub 31}Cl{sub 10} nanostructure is a direct electron transition semiconductor. ► The broad and intensive UV emission were observed in Bi{sub 24}O{sub 31}Cl{sub 10} nanostructure. - Abstract: Nanostructured BiOCl and Bi{sub 24}O{sub 31}Cl{sub 10} have been synthesized by electrolytic corrosion of metal Bi. The photocatalysis and photoluminescence (PL) properties of BiOCl and Bi{sub 24}O{sub 31}Cl{sub 10} nanostructures have been investigated. Nanosheets with a thickness of ∼10 nm and in-plane size of 30–60 nm were obtained in the as-synthesized BiOCl. The emission spectra excited at 360 nm consist of two broad emission bands: ultraviolet-blue and visible. The visible emission is responsible for the photocatalytic activity of BiOCl under visible light irradiation. The nanostructured Bi{sub 24}O{sub 31}Cl{sub 10}, self-assembled by uniform nanosheets with a thickness of 10–20 nm, exhibits a broad and strong blue shift UV emission at room temperature.

  13. Cross-links between ribosomal proteins of 30S subunits in 70S tight couples and in 30S subunits.

    PubMed

    Lambert, J M; Boileau, G; Cover, J A; Traut, R R

    1983-08-01

    Ribosome 70S tight couples and 30S subunits derived from them were modified with 2-iminothiolane under conditions where about two sulfhydryl groups per protein were added to the ribosomal particles. The 70S and 30S particles were not treated with elevated concentrations of NH4Cl, in contrast to those used in earlier studies. The modified particles were oxidized to promote disulfide bond formation. Proteins were extracted from the cross-linked particles by using conditions to preclude disulfide interchange. Disulfide-linked protein complexes were fractionated on the basis of charge by electrophoresis in polyacrylamide/urea gels at pH 5.5. The proteins from sequential slices of the urea gels were analyzed by two-dimensional diagonal polyacrylamide/sodium dodecyl sulfate gel electrophoresis. Final identification of proteins in cross-linked complexes was made by radioiodination of the proteins, followed by two-dimensional polyacrylamide/urea gel electrophoresis. Attention was focused on cross-links between 30S proteins. We report the identification of 27 cross-linked dimers and 2 trimers of 30S proteins, all but one of which were found in both 70S ribosomes and free 30S subunits in similar yield. Seven of the cross-links, S3-S13, S13-S21, S14-S19, S7-S12, S9-S13, S11-S21, and S6-S18-S21, have not been reported previously when 2-iminothiolane was used. Cross-links S3-S13, S13-S21, S7-S12, S11-S21, and S6-S18-S21 are reported for the first time. The identification of the seven new cross-links is illustrated and discussed in detail. Ten of the dimers reported in the earlier studies of Sommer & Traut (1976) [Sommer, A., & Traut, R. R. (1976) J. Mol. Biol. 106, 995-1015], using 30S subunits treated with high salt concentrations, were not found in the experiments reported here.

  14. Molecular mechanics of 30S subunit head rotation.

    PubMed

    Mohan, Srividya; Donohue, John Paul; Noller, Harry F

    2014-09-16

    During ribosomal translocation, a process central to the elongation phase of protein synthesis, movement of mRNA and tRNAs requires large-scale rotation of the head domain of the small (30S) subunit of the ribosome. It has generally been accepted that the head rotates by pivoting around the neck helix (h28) of 16S rRNA, its sole covalent connection to the body domain. Surprisingly, we observe that the calculated axis of rotation does not coincide with the neck. Instead, comparative structure analysis across 55 ribosome structures shows that 30S head movement results from flexing at two hinge points lying within conserved elements of 16S rRNA. Hinge 1, although located within the neck, moves by straightening of the kinked helix h28 at the point of contact with the mRNA. Hinge 2 lies within a three-way helix junction that extends to the body through a second, noncovalent connection; its movement results from flexing between helices h34 and h35 in a plane orthogonal to the movement of hinge 1. Concerted movement at these two hinges accounts for the observed magnitudes of head rotation. Our findings also explain the mode of action of spectinomycin, an antibiotic that blocks translocation by binding to hinge 2.

  15. Finite pure integer programming algorithms employing only hyperspherically deduced cuts

    NASA Technical Reports Server (NTRS)

    Young, R. D.

    1971-01-01

    Three algorithms are developed that may be based exclusively on hyperspherically deduced cuts. The algorithms only apply, therefore, to problems structured so that these cuts are valid. The algorithms are shown to be finite.

  16. {sup 30}S({alpha}, p) in X-Ray Bursts at CRIB

    SciTech Connect

    Kahl, D.; Kubono, S.; Binh, D. N.; Hashimoto, T.; Hayakawa, S.; Kurihara, Y.; Ohshiro, Y.; Yamaguchi, H.; Chen, A. A.; Chen, J.; Setoodeh nia, K.; Kaji, D.; Nishimura, S.; Kim, A.; Lee, N. H.; Wakabayashi, Y.

    2010-08-12

    Over the past three years, we have worked on developing a well-characterized {sup 30}S radioactive beam to be used in a future experiment aiming to directly measure the {sup 30}S({alpha}, p) stellar reaction rate within the Gamow window of Type I X-ray bursts.

  17. Deducing Reaction Mechanism: A Guide for Students, Researchers, and Instructors

    ERIC Educational Resources Information Center

    Meek, Simon J.; Pitman, Catherine L.; Miller, Alexander J. M.

    2016-01-01

    An introductory guide to deducing the mechanism of chemical reactions is presented. Following a typical workflow for probing reaction mechanism, the guide introduces a wide range of kinetic and mechanistic tools. In addition to serving as a broad introduction to mechanistic analysis for students and researchers, the guide has also been used by…

  18. Goniometer-based femtosecond X-ray diffraction of mutant 30S ribosomal subunit crystals

    SciTech Connect

    Dao, E. Han; Sierra, Raymond G.; Laksmono, Hartawan; Lemke, Henrik T.; Alonso-Mori, Roberto; Coey, Aaron; Larsen, Kevin; Baxter, Elizabeth L.; Cohen, Aina E.; Soltis, S. Michael; DeMirci, Hasan

    2015-04-30

    In this work, we collected radiation-damage-free data from a set of cryo-cooled crystals for a novel 30S ribosomal subunit mutant using goniometer-based femtosecond crystallography. Crystal quality assessment for these samples was conducted at the X-ray Pump Probe end-station of the Linac Coherent Light Source (LCLS) using recently introduced goniometer-based instrumentation. These 30S subunit crystals were genetically engineered to omit a 26-residue protein, Thx, which is present in the wild-type Thermus thermophilus 30S ribosomal subunit. We are primarily interested in elucidating the contribution of this ribosomal protein to the overall 30S subunit structure. To assess the viability of this study, femtosecond X-ray diffraction patterns from these crystals were recorded at the LCLS during a protein crystal screening beam time. During our data collection, we successfully observed diffraction from these difficult-to-grow 30S ribosomal subunit crystals. Most of our crystals were found to diffract to low resolution, while one crystal diffracted to 3.2 Å resolution. These data suggest the feasibility of pursuing high-resolution data collection as well as the need to improve sample preparation and handling in order to collect a complete radiation-damage-free data set using an X-ray Free Electron Laser.

  19. Goniometer-based femtosecond X-ray diffraction of mutant 30S ribosomal subunit crystals

    DOE PAGES

    Dao, E. Han; Sierra, Raymond G.; Laksmono, Hartawan; Lemke, Henrik T.; Alonso-Mori, Roberto; Coey, Aaron; Larsen, Kevin; Baxter, Elizabeth L.; Cohen, Aina E.; Soltis, S. Michael; et al

    2015-04-30

    In this work, we collected radiation-damage-free data from a set of cryo-cooled crystals for a novel 30S ribosomal subunit mutant using goniometer-based femtosecond crystallography. Crystal quality assessment for these samples was conducted at the X-ray Pump Probe end-station of the Linac Coherent Light Source (LCLS) using recently introduced goniometer-based instrumentation. These 30S subunit crystals were genetically engineered to omit a 26-residue protein, Thx, which is present in the wild-type Thermus thermophilus 30S ribosomal subunit. We are primarily interested in elucidating the contribution of this ribosomal protein to the overall 30S subunit structure. To assess the viability of this study, femtosecondmore » X-ray diffraction patterns from these crystals were recorded at the LCLS during a protein crystal screening beam time. During our data collection, we successfully observed diffraction from these difficult-to-grow 30S ribosomal subunit crystals. Most of our crystals were found to diffract to low resolution, while one crystal diffracted to 3.2 Å resolution. These data suggest the feasibility of pursuing high-resolution data collection as well as the need to improve sample preparation and handling in order to collect a complete radiation-damage-free data set using an X-ray Free Electron Laser.« less

  20. Experimental investigation of the 30S(α, p) thermonuclear reaction in x-ray bursts

    NASA Astrophysics Data System (ADS)

    Kahl, D.; Chen, A. A.; Kubono, S.; Yamaguchi, H.; Binh, D. N.; Chen, J.; Cherubini, S.; Duy, N. N.; Hashimoto, T.; Hayakawa, S.; Iwasa, N.; Jung, H. S.; Kato, S.; Kwon, Y. K.; Nishimura, S.; Ota, S.; Setoodehnia, K.; Teranishi, T.; Tokieda, H.; Yamada, T.; Yun, C. C.; Zhang, L. Y.

    2016-02-01

    We performed the first measurement of 30S+α resonant elastic scattering to experimentally examine the 30S(α, p) stellar reaction rate in type I x-ray bursts. These bursts are the most frequent thermonuclear explosions in the galaxy, resulting from thermonuclear runaway on the surface of accreting neutron star binaries. The 30S(α, p) reaction plays a critical role in burst models, yet very little is known about the compound nucleus 34Ar at these energies nor the reaction rate itself. We performed a measurement of alpha elastic scattering with a radioactive beam of 30S to experimentally probe the entrance channel. Utilizing a gaseous active target system and silicon detector array, we extracted the excitation function from 1.8 to 5.5 MeV near 160° in the center-of-mass frame. The experimental data were analyzed with an R-Matrix calculation, and we discovered several new resonances and extracted their quantum properties (resonance energy, width, spin, and parity). Finally, we calculated the narrow resonant thermonuclear reaction rate of 30S(α, p) for these new resonances.

  1. The protein composition of reconstituted 30S ribosomal subunits: the effects of single protein omission.

    PubMed

    Buck, M A; Olah, T V; Perrault, A R; Cooperman, B S

    1991-06-01

    Using reverse phase HPLC, we have been able to quantify the protein compositions of reconstituted 30S ribosomal subunits, formed either with the full complement of 30S proteins in the reconstitution mix or with a single protein omitted. We denote particles formed in the latter case as SPORE (single protein omission reconstitution) particles. An important goal in 30S reconstitution studies is the formation of reconstituted subunits having uniform protein composition, preferably corresponding to one copy of each protein per reconstituted particle. Here we describe procedures involving variation of the protein:rRNA ratio that approach this goal. In SPORE particles the omission of one protein often results in the partial loss in uptake of other proteins. We also describe procedures to increase the uptake of such proteins into SPORE particles, thus enhancing the utility of the SPORE approach in defining the role of specific proteins in 30S structure and function. The losses of proteins other than the omitted protein provide a measure of protein:protein interaction within the 30S subunit. Most of these losses are predictable on the basis of other such measures. However, we do find evidence for several long-range protein:protein interactions (S6:S3, S6:S12, S10:S16, and S6:S4) that have not been described previously.

  2. General Constraints on Cross Sections Deduced from Surrogate Reactions

    SciTech Connect

    Younes, W

    2003-08-14

    Cross sections that cannot be measured in the laboratory, e.g. because the target lifetime is too short, can be inferred indirectly from a different reaction forming the same compound system, but with a more accessible beam/target combination (the ''surrogate-reaction'' technique). The reactions share the same compound system and a common decay mechanism, but they involve different formation processes. Therefore, an implicit constraint is imposed on the inferred cross section deduced from the measured surrogate-reaction data, through the common decay mechanism. In this paper, the mathematical consequences of this implicit constraint are investigated. General formulas are derived from upper and lower bounds on the inferred cross section, estimated from surrogate data in a procedure which does not require any modeling of the common decay process. As an example, the formulas developed here are applied to the case of the {sup 235}U(n,f) cross section, deduced from {sup 234}U(t,pf) surrogate data. The calculated bounds are not very tight in this particular case. However, by introducing a few qualitative assumptions about the physics of the fission process, meaningful bounds on the deduced cross section are obtained. Upper and lower limits for the cross-section ratio of the (n,f) reaction on the {sup 235}U isomer at E{sub x} = 77 eV relative to the (n,f) reaction on the ground state are also calculated. The generalization of this technique to other surrogate reactions is discussed.

  3. The effect of ribosome assembly cofactors on in vitro 30S subunit reconstitution.

    PubMed

    Bunner, Anne E; Nord, Stefan; Wikström, P Mikael; Williamson, James R

    2010-04-23

    Ribosome biogenesis is facilitated by a growing list of assembly cofactors, including helicases, GTPases, chaperones, and other proteins, but the specific functions of many of these assembly cofactors are still unclear. The effect of three assembly cofactors on 30S ribosome assembly was determined in vitro using a previously developed mass-spectrometry-based method that monitors the rRNA binding kinetics of ribosomal proteins. The essential GTPase Era caused several late-binding proteins to bind rRNA faster when included in a 30S reconstitution. RimP enabled faster binding of S9 and S19 and inhibited the binding of S12 and S13, perhaps by blocking those proteins' binding sites. RimM caused proteins S5 and S12 to bind dramatically faster. These quantitative kinetic data provide important clues about the roles of these assembly cofactors in the mechanism of 30S biogenesis.

  4. mRNA bound to the 30S subunit is a HigB toxin substrate.

    PubMed

    Schureck, Marc A; Maehigashi, Tatsuya; Miles, Stacey J; Marquez, Jhomar; Dunham, Christine M

    2016-08-01

    Activation of bacterial toxins during stress results in cleavage of mRNAs in the context of the ribosome. These toxins are thought to function as global translational inhibitors yet recent studies suggest each may have distinct mRNA specificities that result in selective translation for bacterial survival. Here we demonstrate that mRNA in the context of a bacterial 30S subunit is sufficient for ribosome-dependent toxin HigB endonucleolytic activity, suggesting that HigB interferes with the initiation step of translation. We determined the X-ray crystal structure of HigB bound to the 30S, revealing that two solvent-exposed clusters of HigB basic residues directly interact with 30S 16S rRNA helices 18, 30, and 31. We further show that these HigB residues are essential for ribosome recognition and function. Comparison with other ribosome-dependent toxins RelE and YoeB reveals that each interacts with similar features of the 30S aminoacyl (A) site yet does so through presentation of diverse structural motifs.

  5. Binding of 16S rRNA to chloroplast 30S ribosomal proteins blotted on nitrocellulose.

    PubMed

    Rozier, C; Mache, R

    1984-10-11

    Protein-RNA associations were studied by a method using proteins blotted on a nitrocellulose sheet. This method was assayed with Escherichia Coli 30S ribosomal components. In stringent conditions (300 mM NaCl or 20 degrees C) only 9 E. coli ribosomal proteins strongly bound to the 16S rRNA: S4, S5, S7, S9, S12, S13, S14, S19, S20. 8 of these proteins have been previously found to bind independently to the 16S rRNA. The same method was applied to determine protein-RNA interactions in spinach chloroplast 30S ribosomal subunits. A set of only 7 proteins was bound to chloroplast rRNA in stringent conditions: chloroplast S6, S10, S11, S14, S15, S17 and S22. They also bound to E. coli 16S rRNA. This set includes 4 chloroplast-synthesized proteins: S6, S11, S15 and S22. The core particles obtained after treatment by LiCl of chloroplast 30S ribosomal subunit contained 3 proteins (S6, S10 and S14) which are included in the set of 7 binding proteins. This set of proteins probably play a part in the early steps of the assembly of the chloroplast 30S ribosomal subunit.

  6. Microcrack growth parameters for compact bone deduced from stiffness variations.

    PubMed

    Taylor, D

    1998-07-01

    This paper shows how information on the fatigue behaviour of microcracks can be obtained by the analysis of stiffness changes measured during cyclic loading. Relationships between crack length, growth rate and cyclic stress intensity were deduced, and compared with previous empirical equations. Results show that the crack growth rate decreases rapidly with increasing length; this behaviour is typical of short-crack fatigue in many materials and is interpreted in terms of microstructural barriers to growth. Implications for the role of microcracks in remodelling and adaptation phenomena are discussed.

  7. Exploring assembly energetics of the 30S ribosomal subunit using an implicit solvent approach.

    PubMed

    Trylska, Joanna; McCammon, J Andrew; Brooks Iii, Charles L

    2005-08-10

    To explore the relationship between the assembly of the 30S ribosomal subunit and interactions among the constituent components, 16S RNA and proteins, relative binding free energies of the T. thermophilus 30S proteins to the 16S RNA were studied based on an implicit solvent model of electrostatic, nonpolar, and entropic contributions. The late binding proteins in our assembly map were found not to bind to the naked 16S RNA. The 5' domain early kinetic class proteins, on average, carry the highest positive charge, get buried the most upon binding to 16S RNA, and show the most favorable binding. Some proteins (S10/S14, S6/S18, S13/S19) have more stabilizing interactions while binding as dimers. Our computed assembly map resembles that of E. coli; however, the central domain path is more similar to that of A. aeolicus, a hyperthermophilic bacteria.

  8. Growth, Persistence, and Desistance of Alcohol Use for At-Risk Men in Their 30s

    PubMed Central

    Capaldi, Deborah M.; Tiberio, Stacey S.; Washburn, Isaac J.; Yoerger, Karen; Feingold, Alan

    2015-01-01

    Background Little is known about heterogeneity in men's drinking behaviors and their related consequences across midadulthood, and moreover, whether individual or social factors may predict such differences. The present study examined 3 indicators of alcohol use; namely, alcohol volume, heavy episodic drinking (HED), and drinking-related problems for men in their 30s. Methods Participants were 197 at-risk men from the Oregon Youth Study assessed 5 times across ages 29–38 years. Growth mixture modeling with count outcomes was used to examine unobserved heterogeneity in alcohol trajectories. Associations of latent classes of alcohol users with (i) classes for the other alcohol indicators, (ii) alcohol use by peers and romantic partners, (iii) alcohol classes previously extracted from ages 18–29 years, and (iv) past year alcohol use disorder (AUD) diagnostic status at ages 35–36 years was examined. Results A 3-class solution afforded the best fit for each alcohol indicator. Alcohol problems were relatively established in the 30s, with an ascending use class found only for volume. Although relatively few men were in higher classes for all 3 indicators, 45% of the sample was in the highest class on at least 2 indicators of use. Peer drunkenness was a robust predictor of the alcohol classes. Concordance among classes of alcohol users was seen from the 20s to the 30s, with prior desistance likely to be maintained for alcohol volume and HED. AUD diagnoses at ages 35–36 years were more common in the higher classes obtained for alcohol volume and alcohol problems. Conclusions Many men in their 30s engaged in high volume of alcohol without frequent engagement in HED, likely relating to continuing alcohol problems. The convergence of men's alcohol use with that of their peers found at younger ages was maintained into early midadulthood. PMID:26010338

  9. Neutron Scattering and the 30 S Ribosomal Subunit of E. Coli

    DOE R&D Accomplishments Database

    Moore, P. B.; Engelman, D. M.; Langer, J. A.; Ramakrishnan, V. R.; Schindler, D. G.; Schoenborn, B. P.; Sillers, I. Y.; Yabuki, S.

    1982-06-01

    This paper reviews the progress made in the study of the internal organization of the 30 S ribosomal subunit of E. coli by neutron scattering since 1975. A map of that particle showing the position of 14 of the subunit's 21 proteins is presented, and the methods currently used for collecting and analyzing such data are discussed. Also discussed is the possibility of extending the interpretation of neutron mapping data beyond the limits practical today.

  10. Neutron scattering and the 30 S ribosomal subunit of E. coli

    SciTech Connect

    Moore, P.B.; Engelman, D.M.; Langer, J.A.; Ramakrishnan, V.R.; Schindler, D.G.; Schoenborn, B.P.; Sillers, I.Y.; Yabuki, S.

    1982-01-01

    This paper reviews the progress made in the study of the internal organization of the 30 S ribosomal subunit of E. coli by neutron scattering since 1975. A map of that particle showing the position of 14 of the subunit's 21 proteins is presented, and the methods currently used for collecting and analyzing such data are discussed. Also discussed is the possibility of extending the interpretation of neutron mapping data beyond the limits practical today. 30 references, 5 figures.

  11. A purified nucleoprotein fragment of the 30 S ribosomal subunit of Escherichia coli.

    PubMed

    Spitnik-Elson, P; Elson, D; Abramowitz, R

    1979-02-27

    A '13 S' nucleoprotein fragment was isolated from a nuclease digest of Escherichia coli 30-S ribosomal subunits and purified to gel electrophoretic homogeneity. It contained two polynucleotides, of about 1.1 . 10(5) and 2.5 . 10(4) daltons, which separated when the fragment was deproteinized. The major protein components were S4, S7 and S9/11, with S15, S16, S18, S19 and S20 present in reduced amount.

  12. A role for the 30S subunit E site in maintenance of the translational reading frame

    PubMed Central

    Devaraj, Aishwarya; Shoji, Shinichiro; Holbrook, Eric D.; Fredrick, Kurt

    2009-01-01

    The exit (E) site has been implicated in several ribosomal activities, including translocation, decoding, and maintenance of the translational reading frame. Here, we target the 30S subunit E site by introducing a deletion in rpsG that truncates the β-hairpin of ribosomal protein S7. This mutation (S7ΔR77–Y84) increases both −1 and +1 frameshifting but does not increase miscoding, providing evidence that the 30S E site plays a specific role in frame maintenance. Mutation S7ΔR77–Y84 also stimulates +1 programmed frameshifting during prfB′-lacZ translation in many synthetic contexts. However, no effect is seen when the E codon of the frameshift site corresponds to those found in nature, suggesting that E-tRNA release does not normally limit the rate of prfB frameshifting. Ribosomes containing S7ΔR77–Y84 exhibit an elevated rate of spontaneous reverse translocation and an increased K 1/2 for E-tRNA. These effects are of similar magnitude, suggesting that both result from destabilization of E-tRNA. Finally, this mutation of the 30S E site does not inhibit EF-G-dependent translocation, consistent with a primary role for the 50S E site in the mechanism. PMID:19095617

  13. Concurrent Nucleation of 16S Folding and Induced Fit in 30S Ribosome Assembly

    SciTech Connect

    Adilakshmi, T.; Bellur, D; Woodson, S

    2008-01-01

    Rapidly growing cells produce thousands of new ribosomes each minute, in a tightly regulated process that is essential to cell growth. How the Escherichia coli 16S ribosomal RNA and the 20 proteins that make up the 30S ribosomal subunit can assemble correctly in a few minutes remains a challenging problem, partly because of the lack of real-time data on the earliest stages of assembly. By providing snapshots of individual RNA and protein interactions as they emerge in real time, here we show that 30S assembly nucleates concurrently from different points along the rRNA. Time-resolved hydroxyl radical footprinting3 was used to map changes in the structure of the rRNA within 20 milliseconds after the addition of total 30S proteins. Helical junctions in each domain fold within 100 ms. In contrast, interactions surrounding the decoding site and between the 5', the central and the 3' domains require 2-200 seconds to form. Unexpectedly, nucleotides contacted by the same protein are protected at different rates, indicating that initial RNA-protein encounter complexes refold during assembly. Although early steps in assembly are linked to intrinsically stable rRNA structure, later steps correspond to regions of induced fit between the proteins and the rRNA.

  14. Seven theses on pigeon homing deduced from empirical findings

    PubMed

    Wallraff

    1996-01-01

    Experimental findings obtained in recent years make it possible to recognize and distinguish the most relevant components determining homing flights of displaced pigeons. Conclusions deduced from these experiments, more or less compelling or tentative, are presented in the form of seven theses, supplemented by several subtheses along with reference to empirical data. The principal theses are as follows. (1) Passively displaced pigeons find the way home by using location-dependent signals and not by path integration based on recording of motion. Pigeons are able to home, even from unfamiliar areas, without access to potentially useful information during transport to the release site. (2) Home-related orientation of pigeons in unfamiliar areas requires positional information acquired olfactorily from atmospheric trace gases. Empirically deduced details of olfactory navigation are enumerated (connection with winds and the sun, inaccuracy, spatial range, time course of sampling and memorizing spatial information, etc.). The critical gap in our knowledge, i.e. the nature and spatio-temporal distribution of the substances involved, is provisionally filled by speculation. (3) In familiar areas, known from previous flights, the visual landscape is used additionally to find the way home. (4) Initial orientation of pigeons does not exclusively reflect home-related navigation but includes components independent of the position with respect to home. Observed bearings are co-determined by a general preference for a certain compass direction and by distracting features of the nearby landscape. (5) Proportions among components controlling initial orientation according to theses 2-4 are highly variable depending on local, temporal and experimental conditions and on the life histories of the pigeons. This complexity greatly restricts recognition of the navigationally relevant components of behaviour at a given release site. (6) Sensory inputs, being neither olfactory nor visual, do

  15. Crystal Structure of the 30S Ribosomal Subunit from Thermus Thermophilus. Purification, Crystallization and Structure Determination

    SciTech Connect

    Clemons, William M.; Brodersen, Ditlev E.; McCutcheonn, John P.; May, Joanna L.C.; Carter, Andrew P.; Morgan-Warren, Robert J.; Wimberly, Brian T.; Ramakrishnan, Venki

    2009-10-07

    We describe the crystallization and structure determination of the 30 S ribosomal subunit from Thermus thermophilus. Previous reports of crystals that diffracted to 10 {angstrom} resolution were used as a starting point to improve the quality of the diffraction. Eventually, ideas such as the addition of substrates or factors to eliminate conformational heterogeneity proved less important than attention to detail in yielding crystals that diffracted beyond 3 {angstrom} resolution. Despite improvements in technology and methodology in the last decade, the structure determination of the 30 S subunit presented some very challenging technical problems because of the size of the asymmetric unit, crystal variability and sensitivity to radiation damage. Some steps that were useful for determination of the atomic structure were: the use of anomalous scattering from the LIII edges of osmium and lutetium to obtain the necessary phasing signal; the use of tunable, third-generation synchrotron sources to obtain data of reasonable quality at high resolution; collection of derivative data precisely about a mirror plane to preserve small anomalous differences between Bijvoet mates despite extensive radiation damage and multi-crystal scaling; the pre-screening of crystals to ensure quality, isomorphism and the efficient use of scarce third-generation synchrotron time; pre-incubation of crystals in cobalt hexaammine to ensure isomorphism with other derivatives; and finally, the placement of proteins whose structures had been previously solved in isolation, in conjunction with biochemical data on protein-RNA interactions, to map out the architecture of the 30 S subunit prior to the construction of a detailed atomic-resolution model.

  16. Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients

    PubMed Central

    Redwood, W. R.; Rall, E.; Perl, W.

    1974-01-01

    The permeability coefficients of dog red cell membrane to tritiated water and to a series of[14C]amides have been deduced from bulk diffusion measurements through a "tissue" composed of packed red cells. Red cells were packed by centrifugation inside polyethylene tubing. The red cell column was pulsed at one end with radiolabeled solute and diffusion was allowed to proceed for several hours. The distribution of radioactivity along the red cell column was measured by sequential slicing and counting, and the diffusion coefficient was determined by a simple plotting technique, assuming a one-dimensional diffusional model. In order to derive the red cell membrane permeability coefficient from the bulk diffusion coefficient, the red cells were assumed to be packed in a regular manner approximating closely spaced parallelopipeds. The local steady-state diffusional flux was idealized as a one-dimensional intracellular pathway in parallel with a one-dimensional extracellular pathway with solute exchange occurring within the series pathway and between the pathways. The diffusion coefficients in the intracellular and extracellular pathways were estimated from bulk diffusion measurements through concentrated hemoglobin solutions and plasma, respectively; while the volume of the extracellular pathway was determined using radiolabeled sucrose. The membrane permeability coefficients were in satisfactory agreement with the data of Sha'afi, R. I., C. M. Gary-Bobo, and A. K. Solomon (1971. J. Gen. Physiol. 58:238) obtained by a rapid-reaction technique. The method is simple and particularly well suited for rapidly permeating solutes. PMID:4443795

  17. Deducing high-altitude precipitation from glacier mass balance measurements

    NASA Astrophysics Data System (ADS)

    Giesen, Rianne H.; Immerzeel, Walter W.; Wanders, Niko

    2016-04-01

    The spatial distribution of precipitation in mountainous terrain is generally not well known due to underrepresentation of gauge observations at higher elevations. Precipitation tends to increase with elevation, but since observations are mainly performed in the valleys, the vertical precipitation gradient cannot be deduced from these measurements. Furthermore, the spatial resolution of gridded meteorological data is often too coarse to resolve individual mountain chains. Still, a reliable estimate of high-elevation precipitation is required for many hydrological applications. We present a method to determine the vertical precipitation gradient in mountainous terrain, making use of glacier mass balance observations. These measurements have the advantage that they provide a basin-wide precipitation estimate at high elevations. The precipitation gradient is adjusted until the solid precipitation over the glacier area combined with the calculated melt gives the measured annual glacier mass balance. Results for the glacierized regions in Central Europe and Scandinavia reveal spatially coherent patterns, with predominantly positive precipitation gradients ranging from -4 to +28 % (100 m)‑1. In some regions, precipitation amounts at high elevations are up to four times as large as in the valleys. A comparison of the modelled winter precipitation with observed snow accumulation on glaciers shows a good agreement. Precipitation measured at the few high-altitude meteorological stations is generally lower than our estimate, which may result from precipitation undercatch. Our findings will improve the precipitation forcing for glacier modelling and hydrological studies in mountainous terrain.

  18. Venus surface properties deduced from radar and radiometry

    NASA Technical Reports Server (NTRS)

    Ford, P. G.

    1989-01-01

    The brightness of surface features on side looking radar images of Venus is determined by many factors: the angles of incidence and reflection, polarization, surface geometry and composition, and so forth. The contribution from surface properties themselves can only be deduced by combining several types of measurement. For instance, without additional information, it is impossible to distinguish the effects of changes in surface roughness from those in dielectric constant. In common with the Moon and Mars, the surface of Venus appears to scatter radar waves in two ways: small-scale surface inhomogeneities, i.e., those smaller than the incident wavelength, depolarize and scatter the energy over a wide range of angles. The Pioneer Venus radar mapper experiment made three overlapping sets of measurements of the equatorial region of Venus from 15 deg S latitude to 45 deg N; the backscatter cross section at a range of incidence angles, the shape and intensity of radar echoes from the nadir, and the microwave brightness temperature of the surface. These techniques developed during the analysis of Pioneer Venus data will be used during the Magellan mission to extract measurements of surface slopes and dielectric constants over all areas covered by the SAR and altimeter antennae, with a resolution of about 10 km. A knowledge of the mechanisms that govern surface scattering will also be useful in the analysis of higher resolution side looking radar images, particularly in distinguishing the effects of changing roughness from those caused by a long range surface tilt or changing dielectric constant.

  19. RsgA releases RbfA from 30S ribosome during a late stage of ribosome biosynthesis

    PubMed Central

    Goto, Simon; Kato, Shingo; Kimura, Takatsugu; Muto, Akira; Himeno, Hyouta

    2011-01-01

    RsgA is a 30S ribosomal subunit-binding GTPase with an unknown function, shortage of which impairs maturation of the 30S subunit. We identified multiple gain-of-function mutants of Escherichia coli rbfA, the gene for a ribosome-binding factor, that suppress defects in growth and maturation of the 30S subunit of an rsgA-null strain. These mutations promote spontaneous release of RbfA from the 30S subunit, indicating that cellular disorders upon depletion of RsgA are due to prolonged retention of RbfA on the 30S subunit. We also found that RsgA enhances release of RbfA from the mature 30S subunit in a GTP-dependent manner but not from a precursor form of the 30S subunit. These findings indicate that the function of RsgA is to release RbfA from the 30S subunit during a late stage of ribosome biosynthesis. This is the first example of the action of a GTPase on the bacterial ribosome assembly described at the molecular level. PMID:21102555

  20. Does power indicate capacity? 30-s Wingate anaerobic test vs. maximal accumulated O2 deficit.

    PubMed

    Minahan, C; Chia, M; Inbar, O

    2007-10-01

    The purpose of this study was to evaluate the relationship between anaerobic power and capacity. Seven men and seven women performed a 30-s Wingate Anaerobic Test on a cycle ergometer to determine peak power, mean power, and the fatigue index. Subjects also cycled at a work rate predicted to elicit 120 % of peak oxygen uptake to exhaustion to determine the maximal accumulated O (2) deficit. Peak power and the maximal accumulated O (2) deficit were significantly correlated (r = 0.782, p = 0.001). However, when the absolute difference in exercise values between groups (men and women) was held constant using a partial correlation, the relationship diminished (r = 0.531, p = 0.062). In contrast, we observed a significant correlation between fatigue index and the maximal accumulated O (2) deficit when controlling for gender (r = - 0.597, p = 0.024) and the relationship remained significant when values were expressed relative to active muscle mass. A higher anaerobic power does not indicate a greater anaerobic capacity. Furthermore, we suggest that the ability to maintain power output during a 30-s cycle sprint is related to anaerobic capacity.

  1. Atmospheric response to Saharan dust deduced from ECMWF reanalysis increments

    NASA Astrophysics Data System (ADS)

    Kishcha, P.; Alpert, P.; Barkan, J.; Kirchner, I.; Machenhauer, B.

    2003-04-01

    This study focuses on the atmospheric temperature response to dust deduced from a new source of data - the European Reanalysis (ERA) increments. These increments are the systematic errors of global climate models, generated in reanalysis procedure. The model errors result not only from the lack of desert dust but also from a complex combination of many kinds of model errors. Over the Sahara desert the dust radiative effect is believed to be a predominant model defect which should significantly affect the increments. This dust effect was examined by considering correlation between the increments and remotely-sensed dust. Comparisons were made between April temporal variations of the ERA analysis increments and the variations of the Total Ozone Mapping Spectrometer aerosol index (AI) between 1979 and 1993. The distinctive structure was identified in the distribution of correlation composed of three nested areas with high positive correlation (> 0.5), low correlation, and high negative correlation (<-0.5). The innermost positive correlation area (PCA) is a large area near the center of the Sahara desert. For some local maxima inside this area the correlation even exceeds 0.8. The outermost negative correlation area (NCA) is not uniform. It consists of some areas over the eastern and western parts of North Africa with a relatively small amount of dust. Inside those areas both positive and negative high correlations exist at pressure levels ranging from 850 to 700 hPa, with the peak values near 775 hPa. Dust-forced heating (cooling) inside the PCA (NCA) is accompanied by changes in the static stability of the atmosphere above the dust layer. The reanalysis data of the European Center for Medium Range Weather Forecast(ECMWF) suggests that the PCA (NCA) corresponds mainly to anticyclonic (cyclonic) flow, negative (positive) vorticity, and downward (upward) airflow. These facts indicate an interaction between dust-forced heating /cooling and atmospheric circulation. The

  2. Secondary structures of proteins from the 30S subunit of the Escherichia coli ribosome.

    PubMed

    Dzionara, M; Robinson, S M; Wittmann-Liebold, B

    1977-08-01

    The secondary structures of the proteins S4, S6, S8, S9, S12, S13, S15, S16, S18, S20 and S21 from the subunit of the E. coli ribosome were predicted according to four different methods. From the resultant diagrams indicating regions of helix, turn, extended structure and random coil, average values for the respective secondary structures could be calculated for each protein. Using the known relative distances for residues in the helical, turn and sheet or allowed random conformations, estimates are made of the maximum possible lengths of the proteins in order to correlate these with results obtained from antibody binding studies to the 30S subunit as determined by electron microscopy. The influence of amino acid changes on the predicted secondary structures of proteins from a few selected mutants was studied. The altered residues tend to be structurally conservative or to induce only minimal local changes.

  3. Advance of the perihelion of Mercury deduced from QFT

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Guang

    I deduce the new gravitational formula from the variance in mass of QFT and GR (H05-0029-08, E15-0039 -08, E14-0032-08, D31-0054-10) in the partial differential: f (QFT) = f (GR) = delta∂ (m v)/delta∂ t = f _{P} + f _{C} , f _{P} = m delta∂ v / delta∂ t = - ( G m M /r (2) ) r / r, f _{C} = v delta∂ m / delta∂ t = - ( G m M / r (2) ) v / c (1), f (QFT) is the quasi-Casimir pressure of net virtual neutrinos nuν _{0} flux (after counteract contrary direction nuν _{0}). f (GR) is equivalent to Einstein’s equation, Eq. (1) is a new version of GR and can be solved exactly. Its core content is that the gravity produced by particles collide cannot linear addition, i.e., the nonlinearity of Einstein equation had been replaced by the nonlinearity caused by the variable mass in Eq.(1). Einstein equation can be inferred from Eq.(1) thereby from QFT, but QFT cannot be inferred from Eq.(1) or GR. f (QFT) is essential but f (GR) is phenomenological. Eq.(1) is obtained just by to absorb the essence of corpuscule collided gravitation origin ism proposed by Fatio in 1690 and 1920 Majorana’s experiment concept about gravitational shield effect again fuse with QFT. In my paper ‘QFT’S advance of the perihelion of Mercury, China Science &Technology Overview 125 88-90 (2011)’ QFT gravitational potential U = - G M /r is just the distribution density of net nuν _{0} flux, from SR we again get that: f (QFT) = f _{P} + f _{C}, f _{P} = - m ( delta∂ U / delta∂ r) r / r, f _{C} = - m ( delta∂U / delta∂ r) v / c (2), f _{ P} correspond the change rate of three-dimensional momentum p, f _{C} correspond the change rate of fourth dimensional momentum i m c which show directly as a dissipative force of mass change. According to Eq.(2) the circular motion is instability and elliptic motion is in the auto-stability state. In the fluctuation vacuum a particle with mass M neighbor another particle with mass m, the renormalization mass M and m will be less than that when

  4. Switching off the tackiness of a nanocomposite adhesive in 30 s via infrared sintering.

    PubMed

    Gurney, Robert S; Dupin, Damien; Nunes, Juliana S; Ouzineb, Keltoum; Siband, Elodie; Asua, José M; Armes, Steven P; Keddie, Joseph L

    2012-10-24

    Soft adhesives require an optimum balance of viscous and elastic properties. Adhesion is poor when the material is either too solidlike or too liquidlike. The ability to switch tack adhesion off at a desired time has many applications, such as in recycling, disassembly of electronics, and painless removal of wound dressings. Here, we describe a new strategy to switch off the tack adhesion in a model nanocomposite adhesive in which temperature is the trigger. The nanocomposite comprises hard methacrylic nanoparticles blended with a colloidal dispersion of soft copolymer particles. At relatively low volume fractions, the nanoparticles (50 nm diameter) accumulate near the film surface, where they pack around the larger soft particles (270 nm). The viscoelasticity of the nanocomposite is adjusted via the nanoparticle concentration. When the nanocomposite is heated above the glass transition temperature of the nanoparticles (T(g) = 130 °C), they sinter together to create a rigid network that raises the elastic modulus at room temperature. The tackiness is switched off. Intense infrared radiation is used to heat the nanocomposites, leading to a fast temperature rise. Tack adhesion is switched off within 30 s in optimized compositions. These one-way switchable adhesives have the potential to be patterned through localized heating. PMID:22974179

  5. Switching off the tackiness of a nanocomposite adhesive in 30 s via infrared sintering.

    PubMed

    Gurney, Robert S; Dupin, Damien; Nunes, Juliana S; Ouzineb, Keltoum; Siband, Elodie; Asua, José M; Armes, Steven P; Keddie, Joseph L

    2012-10-24

    Soft adhesives require an optimum balance of viscous and elastic properties. Adhesion is poor when the material is either too solidlike or too liquidlike. The ability to switch tack adhesion off at a desired time has many applications, such as in recycling, disassembly of electronics, and painless removal of wound dressings. Here, we describe a new strategy to switch off the tack adhesion in a model nanocomposite adhesive in which temperature is the trigger. The nanocomposite comprises hard methacrylic nanoparticles blended with a colloidal dispersion of soft copolymer particles. At relatively low volume fractions, the nanoparticles (50 nm diameter) accumulate near the film surface, where they pack around the larger soft particles (270 nm). The viscoelasticity of the nanocomposite is adjusted via the nanoparticle concentration. When the nanocomposite is heated above the glass transition temperature of the nanoparticles (T(g) = 130 °C), they sinter together to create a rigid network that raises the elastic modulus at room temperature. The tackiness is switched off. Intense infrared radiation is used to heat the nanocomposites, leading to a fast temperature rise. Tack adhesion is switched off within 30 s in optimized compositions. These one-way switchable adhesives have the potential to be patterned through localized heating.

  6. Assembly of the 30S ribosomal subunit: positioning ribosomal protein S13 in the S7 assembly branch.

    PubMed

    Grondek, Joel F; Culver, Gloria M

    2004-12-01

    Studies of Escherichia coli 30S ribosomal subunit assembly have revealed a hierarchical and cooperative association of ribosomal proteins with 16S ribosomal RNA; these results have been used to compile an in vitro 30S subunit assembly map. In single protein addition and omission studies, ribosomal protein S13 was shown to be dependent on the prior association of ribosomal protein S20 for binding to the ribonucleoprotein particle. While the overwhelming majority of interactions revealed in the assembly map are consistent with additional data, the dependency of S13 on S20 is not. Structural studies position S13 in the head of the 30S subunit > 100 A away from S20, which resides near the bottom of the body of the 30S subunit. All of the proteins that reside in the head of the 30S subunit, except S13, have been shown to be part of the S7 assembly branch, that is, they all depend on S7 for association with the assembling 30S subunit. Given these observations, the assembly requirements for S13 were investigated using base-specific chemical footprinting and primer extension analysis. These studies reveal that S13 can bind to 16S rRNA in the presence of S7, but not S20. Additionally, interaction between S13 and other members of the S7 assembly branch have been observed. These results link S13 to the 3' major domain family of proteins, and the S7 assembly branch, placing S13 in a new location in the 30S subunit assembly map where its position is in accordance with much biochemical and structural data.

  7. Tagging ribosomal protein S7 allows rapid identification of mutants defective in assembly and function of 30 S subunits.

    PubMed

    Fredrick, K; Dunny, G M; Noller, H F

    2000-05-01

    Ribosomal protein S7 nucleates folding of the 16 S rRNA 3' major domain, which ultimately forms the head of the 30 S ribosomal subunit. Recent crystal structures indicate that S7 lies on the interface side of the 30 S subunit, near the tRNA binding sites of the ribosome. To map the functional surface of S7, we have tagged the protein with a Protein Kinase A recognition site and engineered alanine substitutions that target each exposed, conserved residue. We have also deleted conserved features of S7, using its structure to guide our design. By radiolabeling the tag sequence using Protein Kinase A, we are able to track the partitioning of each mutant protein into 30 S, 70 S, and polyribosome fractions in vivo. Overexpression of S7 confers a growth defect, and we observe a striking correlation between this phenotype and proficiency in 30 S subunit assembly among our collection of mutants. We find that the side chain of K35 is required for efficient assembly of S7 into 30 S subunits in vivo, whereas those of at least 17 other conserved exposed residues are not required. In addition, an S7 derivative lacking the N-terminal 17 residues causes ribosomes to accumulate on mRNA to abnormally high levels, indicating that our approach can yield interesting mutant ribosomes.

  8. Advance of the perihelion of Mercury deduced from QFT

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Guang

    I deduce the new gravitational formula from the variance in mass of QFT and GR (H05-0029-08, E15-0039 -08, E14-0032-08, D31-0054-10) in the partial differential: f (QFT) = f (GR) = delta∂ (m v)/delta∂ t = f _{P} + f _{C} , f _{P} = m delta∂ v / delta∂ t = - ( G m M /r (2) ) r / r, f _{C} = v delta∂ m / delta∂ t = - ( G m M / r (2) ) v / c (1), f (QFT) is the quasi-Casimir pressure of net virtual neutrinos nuν _{0} flux (after counteract contrary direction nuν _{0}). f (GR) is equivalent to Einstein’s equation, Eq. (1) is a new version of GR and can be solved exactly. Its core content is that the gravity produced by particles collide cannot linear addition, i.e., the nonlinearity of Einstein equation had been replaced by the nonlinearity caused by the variable mass in Eq.(1). Einstein equation can be inferred from Eq.(1) thereby from QFT, but QFT cannot be inferred from Eq.(1) or GR. f (QFT) is essential but f (GR) is phenomenological. Eq.(1) is obtained just by to absorb the essence of corpuscule collided gravitation origin ism proposed by Fatio in 1690 and 1920 Majorana’s experiment concept about gravitational shield effect again fuse with QFT. In my paper ‘QFT’S advance of the perihelion of Mercury, China Science &Technology Overview 125 88-90 (2011)’ QFT gravitational potential U = - G M /r is just the distribution density of net nuν _{0} flux, from SR we again get that: f (QFT) = f _{P} + f _{C}, f _{P} = - m ( delta∂ U / delta∂ r) r / r, f _{C} = - m ( delta∂U / delta∂ r) v / c (2), f _{ P} correspond the change rate of three-dimensional momentum p, f _{C} correspond the change rate of fourth dimensional momentum i m c which show directly as a dissipative force of mass change. According to Eq.(2) the circular motion is instability and elliptic motion is in the auto-stability state. In the fluctuation vacuum a particle with mass M neighbor another particle with mass m, the renormalization mass M and m will be less than that when

  9. PPARA intron polymorphism associated with power performance in 30-s anaerobic Wingate Test.

    PubMed

    Petr, Miroslav; Stastny, Petr; Št'astný, Petr; Pecha, Ondřej; Šteffl, Michal; Šeda, Ondřej; Kohlíková, Eva

    2014-01-01

    To date, polymorphisms in several genes have been associated with a strength/power performance including alpha 3 actinin, ciliary neurotrophic factor, vitamin D receptor, or angiotensin I converting enzyme, underlining the importance of genetic component of the multifactorial strength/power-related phenotypes. The single nucleotide variation in peroxisome proliferator-activated receptor alpha gene (PPARA) intron 7 G/C (rs4253778; g.46630634G>C) has been repeatedly found to play a significant role in response to different types of physical activity. We investigated the effect of PPARA intron 7 G/C polymorphism specifically on anaerobic power output in a group of 77 elite male Czech ice hockey players (18-36 y). We determined the relative peak power per body weight (Pmax.kg(-1)) and relative peak power per fat free mass (W.kg(-1)FFM) during the 30-second Wingate Test (WT30) on bicycle ergometer (Monark 894E Peak bike, MONARK, Sweden). All WT30s were performed during the hockey season. Overall genotype frequencies were 50.6% GG homozygotes, 40.3% CG heterozygotes, and 9.1% CC homozygotes. We found statistically significant differences in Pmax.kg(-1) and marginally significant differences in Pmax.kg(-1)FFM values in WT30 between carriers and non-carriers for C allele (14.6 ± 0.2 vs. 13.9 ± 0.3 W.kg(-1) and 15.8 ± 0.2 vs. 15.2 ± 0.3 W.kg(-1)FFM, P = 0.036 and 0.12, respectively). Furthermore, Pmax.kg(-1)FFM strongly positively correlated with the body weight only in individuals with GG genotypes (R = 0.55; p<0.001). Our results indicate that PPARA 7C carriers exhibited higher speed strength measures in WT30. We hypothesize that C allele carriers within the cohort of trained individuals may possess a metabolic advantage towards anaerobic metabolism.

  10. Efficient reconstitution of functional Escherichia coli 30S ribosomal subunits from a complete set of recombinant small subunit ribosomal proteins.

    PubMed

    Culver, G M; Noller, H F

    1999-06-01

    Previous studies have shown that the 30S ribosomal subunit of Escherichia coli can be reconstituted in vitro from individually purified ribosomal proteins and 16S ribosomal RNA, which were isolated from natural 30S subunits. We have developed a 30S subunit reconstitution system that uses only recombinant ribosomal protein components. The genes encoding E. coli ribosomal proteins S2-S21 were cloned, and all twenty of the individual proteins were overexpressed and purified. Reconstitution, following standard procedures, using the complete set of recombinant proteins and purified 16S ribosomal RNA is highly inefficient. Efficient reconstitution of 30S subunits using these components requires sequential addition of proteins, following either the 30S subunit assembly map (Mizushima & Nomura, 1970, Nature 226:1214-1218; Held et al., 1974, J Biol Chem 249:3103-3111) or following the order of protein assembly predicted from in vitro assembly kinetics (Powers et al., 1993, J MoI Biol 232:362-374). In the first procedure, the proteins were divided into three groups, Group I (S4, S7, S8, S15, S17, and S20), Group II (S5, S6, S9, Sll, S12, S13, S16, S18, and S19), and Group III (S2, S3, S10, S14, and S21), which were sequentially added to 16S rRNA with a 20 min incubation at 42 degrees C following the addition of each group. In the second procedure, the proteins were divided into Group I (S4, S6, S11, S15, S16, S17, S18, and S20), Group II (S7, S8, S9, S13, and S19), Group II' (S5 and S12) and Group III (S2, S3, S10, S14, and S21). Similarly efficient reconstitution is observed whether the proteins are grouped according to the assembly map or according to the results of in vitro 30S subunit assembly kinetics. Although reconstitution of 30S subunits using the recombinant proteins is slightly less efficient than reconstitution using a mixture of total proteins isolated from 30S subunits, it is much more efficient than reconstitution using proteins that were individually isolated

  11. Developmental Trajectories of Marijuana Use among Men: Examining Linkages with Criminal Behavior and Psychopathic Features into the Mid-30s

    PubMed Central

    Pardini, Dustin; Bechtold, Jordan; Loeber, Rolf; White, Helene

    2015-01-01

    Objectives Examine whether young men who chronically use marijuana are at risk for engaging in drug-related and non-drug-related criminal offending and exhibiting psychopathic personality features in their mid-30s. Methods Patterns of marijuana use were delineated in a sample of predominately Black and White young men from adolescence to the mid-20s using latent class growth curve analysis. Self-report and official records of criminal offending and psychopathic personality features were assessed in the mid-30s. Analyses controlled for multiple factors indicative of a preexisting antisocial lifestyle and co-occurring use of other substances and tested for moderation by race. Results Four latent marijuana trajectory groups were identified: chronic high, adolescence-limited, late increasing, and low/nonusers. Relative to low/nonusers, chronic high and late increasing marijuana users exhibited more adult psychopathic features and were more likely to engage in drug-related offending during their mid-30s. Adolescence-limited users were similar to low/nonusers in terms of psychopathic features but were more likely to be arrested for drug-related crimes. No trajectory group differences were found for violence or theft, and the group differences were not moderated by race. Conclusions Young men who engage in chronic marijuana use from adolescence into their 20s are at increased risk for exhibiting psychopathic features, dealing drugs, and enduring drug-related legal problems in their mid-30s relative to men who remain abstinent or use infrequently. PMID:26568641

  12. Positions of proteins S14, S18 and S20 in the 30 S ribosomal subunit of Escherichia coli.

    PubMed

    Ramakrishnan, V; Capel, M; Kjeldgaard, M; Engelman, D M; Moore, P B

    1984-04-01

    A map of the 30 S ribosomal subunit is presented giving the positions of 15 of its 21 proteins. The components located in the map are S1, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S14, S15, S18 and S20.

  13. Spatial Arrangement of Ribosomal Proteins: Reaction of the Escherichia coli 30S Subunit with bis-Imidoesters

    PubMed Central

    Bickle, T. A.; Hershey, J. W. B.; Traut, R. R.

    1972-01-01

    The 30S ribosomal subunit of E. coli was treated with the bifunctional reagent bis-(methyl)suberimidate. Crosslinked ribosomal proteins were identified as bands with increased molecular weight after electrophoresis in polyacrylamide gels containing sodium dodecyl sulphate. The pattern of crosslinked products was altered when unfolded subunits were used. Free ribosomal protein was not crosslinked. Several of the crosslinked products were cleaved by ammonolysis to form the original monomeric protein constituents. The low yields of the reactions necessitated the use of radioactive proteins and auto-radiographic procedures. The crosslinked proteins were tentatively identified by coelectrophoresis of the radioactive ammonolysis products with carrier 30S protein in sodium dodecyl sulphate, and coelectrophoresis at pH 4.5 in buffers containing urea. Images PMID:4556460

  14. Independent in vitro assembly of all three major morphological parts of the 30S ribosomal subunit of Thermus thermophilus.

    PubMed

    Agalarov, S C; Selivanova, O M; Zheleznyakova, E N; Zheleznaya, L A; Matvienko, N I; Spirin, A S

    1999-12-01

    Fragments of the 16S rRNA of Thermus thermophilus representing the 3' domain (nucleotides 890-1515) and the 5' domain (nucleotides 1-539) have been prepared by transcription in vitro. Incubation of these fragments with total 30S ribosomal proteins of T. thermophilus resulted in formation of specific RNPs. The particle assembled on the 3' RNA domain contained seven proteins corresponding to Escherichia coli ribosomal proteins S3, S7, S9, S10, S13, S14, and S19. All of them have previously been shown to interact with the 3' domain of the 16S RNA and to be localized in the head of the 30S ribosomal subunit. The particle formed on the 5' RNA domain contained five ribosomal proteins corresponding to E. coli proteins S4, S12, S17, S16, and S20. These proteins are known to be localized in the main part of the body of the 30S subunit. Both types of particle were compact and had sedimentation coefficients of 15.5 S and 13 S, respectively. Together with our recent demonstration of the reconstitution of the RNA particle representing the platform of the T. thermophilus 30S ribosomal subunit [Agalarov, S.C., Zheleznyakova, E.N., Selivanova, O.M., Zheleznaya, L.A., Matvienko, N.I., Vasiliev, V.D. & Spirin, A.S. (1998) Proc. Natl Acad. Sci. USA 95, 999-1003], these experiments establish that all three main structural lobes of the small ribosomal subunit can be reconstituted independently of each other and prepared in the individual state.

  15. Haiti: Incentives To Improve Basic Education (IIBE)--Project Bilaterial d'Education (PROBED). Midterm Evaluation.

    ERIC Educational Resources Information Center

    Locher, Uli; And Others

    Haiti's Incentives to Improve Basic Education (IIBE) or Project Bilteral d'Education (PROBED) program seeks to stimulate improvements in educational quality and efficiency in private primary schools. The program surpasses other efforts because of: (1) unusually thorough preparation; (2) rapid assumption of management by Haitians; (3) a…

  16. Deducing the 237U destruction cross-sections using the Surrogate Ratio Method

    SciTech Connect

    Bernstein, L A; Burke, J T; Ahle, L; Church, J A; Escher, J; Dietrich, F S; Lyles, B F; Norman, E B; Phair, L W; Bleuel, D L; Clark, R M; Fallon, P; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Ai, H C; Beausang, C W; Crider, B

    2006-03-31

    We have deduced the destruction cross section of {sup 237}U via the (n, {gamma}) and (n,2n) reactions over an equivalent neutron energy range of 0 to 20 MeV using a new form of the Surrogate Ratio method [1-4] . The relative fission and neutron-evaporation decay probabilities of excited {sup 238}U populated via the ({alpha},{alpha}{prime}) inelastic scattering were measured using the silicon telescope array for reaction studies (STARS) coupled to the Livermore Berkeley array for collaborative experiments (LIBERACE). These relative probabilities were then combined with the {sup 237} U(n,f) cross section deduced by Burke et al., [4] to deduce the (n, {gamma}) and (n,2n) cross sections in a model independent fashion. These cross sections are then compared to the compound reaction cross section calculated using an optical model calculation tuned to reproduce scattering data in the transactinide region. Our results presented and the prospects for using this technique to deduce (n,x) cross sections on radioactive nuclei are discussed.

  17. CONSISTENT USE OF THE KALMAN FILTER IN CHEMICAL TRANSPORT MODELS (CTMS) FOR DEDUCING EMISSIONS

    EPA Science Inventory

    Past research has shown that emissions can be deduced using observed concentrations of a chemical, a Chemical Transport Model (CTM), and the Kalman filter in an inverse modeling application. An expression was derived for the relationship between the "observable" (i.e., the con...

  18. Heterogeneity in men's marijuana use in the 20s: adolescent antecedents and consequences in the 30s.

    PubMed

    Washburn, Isaac J; Capaldi, Deborah M

    2015-02-01

    Adolescent psychopathology is commonly connected to marijuana use. How changes in these adolescent antecedents and in adolescent marijuana use are connected to patterns of marijuana use in the 20s is little understood. Another issue not clearly understood is psychopathology in the 30s as predicted by marijuana use in the 20s. This study sought to examine these two issues and the associations with marijuana disorder diagnoses using a longitudinal data set of 205 men with essentially annual reports. Individual psychopathology and family characteristics from the men's adolescence were used to predict their patterns of marijuana use across their 20s, and aspects of the men's psychopathology in their mid-30s were predicted from these patterns. Three patterns of marijuana use in the 20s were identified using growth mixture modeling and were associated with diagnoses of marijuana disorders at age 26 years. Parental marijuana use predicted chronic use for the men in adulthood. Patterns of marijuana use in the 20s predicted antisocial behavior and deviant peer association at age 36 years (controlling for adolescent levels of the outcomes by residualization). These findings indicate that differential patterns of marijuana use in early adulthood are associated with psychopathology toward midlife.

  19. Studies on the ability of partially iodinated 16S RNA to participate in 30S ribosome assembly.

    PubMed

    Schendel, P L; Craven, G R

    1976-11-01

    Deproteinated 16S RNA was iodinated at pH 5.0 in an aqueous solution containing TlCl3 plus KI for 1-5 hours at 42 degrees C. Under these conditions 33 moles of iodine are incorporated per mole of RNA. As judged by sucrose gradient sedimentation, the iodinated RNA does not exhibit any large alteration in conformation as compared to unmodified 16S. The iodinated RNA was examined for its ability to reconstitute with total 30S proteins. Sedimentation velocity analysis reveals that the reconstituted subunit has a sedimentation constant of approximately 20S. In addition, protein analysis of particles reconstituted with 16S RNA iodinated for 5 hours indicates that proteins S2, S10, S13, S14, S15, S17, S18, S19, and S21 are no longer able to participate in the 30S assembly process and that proteins S6, S16 and S20 are present in reduced amounts. The ramifications of these results concerning protein-RNA and RNA-RNA interactions occurring in ribosome assembly are discussed.

  20. Depletion of Free 30S Ribosomal Subunits in Escherichia coli by Expression of RNA Containing Shine-Dalgarno-Like Sequences

    PubMed Central

    Mawn, Mary V.; Fournier, Maurille J.; Tirrell, David A.; Mason, Thomas L.

    2002-01-01

    We have constructed synthetic coding sequences for the expression of poly(α,l-glutamic acid) (PLGA) as fusion proteins with dihydrofolate reductase (DHFR) in Escherichia coli. These PLGA coding sequences use both GAA and GAG codons for glutamic acid and contain sequence elements (5′-GAGGAGG-3′) that resemble the consensus Shine-Dalgarno (SD) sequence found at translation initiation sites in bacterial mRNAs. An unusual feature of DHFR-PLGA expression is that accumulation of the protein is inversely related to the level of induction of its mRNA. Cellular protein synthesis was inhibited >95% by induction of constructs for either translatable or untranslatable PLGA RNAs. Induction of PLGA RNA resulted in the depletion of free 30S ribosomal subunits and the appearance of new complexes in the polyribosome region of the gradient. Unlike normal polyribosomes, these complexes were resistant to breakdown in the presence of puromycin. The novel complexes contained 16S rRNA, 23S rRNA, and PLGA RNA. We conclude that multiple noninitiator SD-like sequences in the PLGA RNA inhibit cellular protein synthesis by sequestering 30S small ribosomal subunits and 70S ribosomes in nonfunctional complexes on the PLGA mRNA. PMID:11751827

  1. Two-neutron knockout from neutron-deficient {sup 34}Ar, {sup 30}S, and {sup 26}Si

    SciTech Connect

    Yoneda, K.; Obertelli, A.; Bazin, D.; Hoagland, T.; Lecouey, J.-L.; Mueller, W. F.; Gade, A.; Brown, B. A.; Campbell, C. M.; Cook, J. M.; Davies, A. D.; Dinca, D.-C.; Glasmacher, T.; Hansen, P. G.; Terry, J. R.; Zwahlen, H.; Cottle, P. D.; Kemper, K. W.; Reynolds, R. R.; Roeder, B. T.

    2006-08-15

    Two-neutron knockout reactions from nuclei in the proximity of the proton dripline have been studied using intermediate-energy beams of neutron-deficient {sup 34}Ar, {sup 30}S, and {sup 26}Si. The inclusive cross sections, and also the partial cross sections for the population of individual bound final states of the {sup 32}Ar, {sup 28}S and {sup 24}Si knockout residues, have been determined using the combination of particle and {gamma}-ray spectroscopy. Similar to the two-proton knockout mechanism on the neutron-rich side of the nuclear chart, these two-neutron removal reactions from already neutron-deficient nuclei are also shown to be consistent with a direct reaction mechanism.

  2. Escherichia coli rimM and yjeQ null strains accumulate immature 30S subunits of similar structure and protein complement

    PubMed Central

    Leong, Vivian; Kent, Meredith; Jomaa, Ahmad; Ortega, Joaquin

    2013-01-01

    Assembly of the Escherichia coli 30S ribosomal subunits proceeds through multiple parallel pathways. The protein factors RimM, YjeQ, RbfA, and Era work in conjunction to assist at the late stages of the maturation process of the small subunit. However, it is unclear how the functional interplay between these factors occurs in the context of multiple parallel pathways. To understand how these factors work together, we have characterized the immature 30S subunits that accumulate in ΔrimM cells and compared them with immature 30S subunits from a ΔyjeQ strain. The cryo-EM maps obtained from these particles showed that the densities representing helices 44 and 45 in the rRNA were partially missing, suggesting mobility of these motifs. These 30S subunits were also partially depleted in all tertiary ribosomal proteins, particularly those binding in the head domain. Using image classification, we identified four subpopulations of ΔrimM immature 30S subunits differing in the amount of missing density for helices 44 and 45, as well as the amount of density existing in these maps for the underrepresented proteins. The structural defects found in these immature subunits resembled those of the 30S subunits that accumulate in the ΔyjeQ strain. These findings are consistent with an “early convergency model” in which multiple parallel assembly pathways of the 30S subunit converge into a late assembly intermediate, as opposed to the mature state. Functionally related factors will bind to this intermediate to catalyze the last steps of maturation leading to the mature 30S subunit. PMID:23611982

  3. Estimation of uncertainty in isotherms deduced from Hugoniots resulting from shockwave generated defects

    NASA Technical Reports Server (NTRS)

    Ruoff, A. L.

    1980-01-01

    The problem of how defect concentrations produced in a shock experiment affect the isothermal equation of state is considered. From the few experimental results available that bear directly on this question, it appears the effect could be substantial, i.e., the pressure in material free of defects may be 10-25% lower at a given volume than the isothermal pressure deduced from Hugoniot data on the assumption that defects are negligible in the shocked material. This correction caused by the presence of defects is called the defect pressure.

  4. Comparison of selection methods to deduce natural background levels for groundwater units.

    PubMed

    Griffioen, Jasper; Passier, Hilde F; Klein, Janneke

    2008-07-01

    Establishment of natural background levels (NBL) for groundwater is commonly performed to serve as reference when assessing the contamination status of groundwater units. We compare various selection methods to establish NBLs using groundwater quality data for four hydrogeologically different areas in the highly populated and developed subcatchment Western River Rhine, The Netherlands: selection of old groundwater (before 1945), of tritium-free groundwater (i.e., infiltrated before 1950), and of groundwater having no agricultural contamination by NO3 and SO4. Differences as well as similarities in percentile values for Cl, NH4, and SO4 concentrations are observed among the selection methods as well as the spatial units, pointing out that selection of the data setis a crucial step in deducing NBLs. The following general points of attention are deduced: (1) reference to composition of recharge water (rain or river infiltrate) is necessary to confirm the statistical outcomes, (2) old analyses are affected by conservation errors after sampling for redox-sensitive solutes and may be obtained by selective sampling, (3) old analyses are the only direct reference for NBLs for groundwater units having only anthropogenically influenced, young groundwater at present, and (4) establishment of a priori percentile values as maximum NBL is not right and confirmation by additional process-based insight in the controls on water composition is necessary.

  5. Near-Surface Flow Fields Deduced Using Correlation Tracking and Time-Distance Analysis

    NASA Technical Reports Server (NTRS)

    DeRosa, Marc; Duvall, T. L., Jr.; Toomre, Juri

    1999-01-01

    Near-photospheric flow fields on the Sun are deduced using two independent methods applied to the same time series of velocity images observed by SOI-MDI on SOHO. Differences in travel times between f modes entering and leaving each pixel measured using time-distance helioseismology are used to determine sites of supergranular outflows. Alternatively, correlation tracking analysis of mesogranular scales of motion applied to the same time series is used to deduce the near-surface flow field. These two approaches provide the means to assess the patterns and evolution of horizontal flows on supergranular scales even near disk center, which is not feasible with direct line-of-sight Doppler measurements. We find that the locations of the supergranular outflows seen in flow fields generated from correlation tracking coincide well with the locations of the outflows determined from the time-distance analysis, with a mean correlation coefficient after smoothing of bar-r(sub s) = 0.840. Near-surface velocity field measurements can used to study the evolution of the supergranular network, as merging and splitting events are observed to occur in these images. The data consist of one 2048-minute time series of high-resolution (0.6" pixels) line-of-sight velocity images taken by MDI on 1997 January 16-18 at a cadence of one minute.

  6. A combined quantitative mass spectrometry and electron microscopy analysis of ribosomal 30S subunit assembly in E. coli

    PubMed Central

    Sashital, Dipali G; Greeman, Candacia A; Lyumkis, Dmitry; Potter, Clinton S; Carragher, Bridget; Williamson, James R

    2014-01-01

    Ribosome assembly is a complex process involving the folding and processing of ribosomal RNAs (rRNAs), concomitant binding of ribosomal proteins (r-proteins), and participation of numerous accessory cofactors. Here, we use a quantitative mass spectrometry/electron microscopy hybrid approach to determine the r-protein composition and conformation of 30S ribosome assembly intermediates in Escherichia coli. The relative timing of assembly of the 3′ domain and the formation of the central pseudoknot (PK) structure depends on the presence of the assembly factor RimP. The central PK is unstable in the absence of RimP, resulting in the accumulation of intermediates in which the 3′-domain is unanchored and the 5′-domain is depleted for r-proteins S5 and S12 that contact the central PK. Our results reveal the importance of the cofactor RimP in central PK formation, and introduce a broadly applicable method for characterizing macromolecular assembly in cells. DOI: http://dx.doi.org/10.7554/eLife.04491.001 PMID:25313868

  7. Analysis of proteins of mouse sarcoma pseudotype viruses: type-specific radioimmunoassay for ecotropic virus p30's.

    PubMed

    Kennel, S J; Tennant, R W

    1979-06-01

    Murine sarcoma virus pseudotypes were prepared by infection of nonproducer cells (A1-2), which were transformed by the Gazdar strain of mouse sarcoma virus, with Gross (N-tropic), WN1802B (B-tropic), or Moloney (NB-tropic) viruses. The respective host range pseudotype sarcoma viruses were defined by the titration characteristics on cells with the appropriate Fv-1 genotype. Proteins from virus progeny were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Bands present in both the 65,000- and the 10,000- to 20,000- molecular-weight regions of the gel distinguished the pseudotype viruses from their respective helpers. Furthermore, two protein bands were noted in the p30 region of murine sarcoma virus (Gross), one corresponding to Gross virus p30, and another of slightly slower mobility. However, since the mobility of the putative sarcoma p30 is nearly indentical to that of WN1802B, its presence could not be established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Type-specific radioimmunoassays for Gross virus p30 and for WN1802B p30 were applied for analysis of pseudotype preparations, and among several ecotropic viruses tested, only the homologous virus scored in the respective assay. By use of these assays, pseudotype viruses were found to contain only 8 to 48% helper-specific p30's; the remainder is presumably derived from the sarcoma virus.

  8. Characterisation of RNA fragments obtained by mild nuclease digestion of 30-S ribosomal subunits from Escherichia coli.

    PubMed

    Rinke, J; Ross, A; Brimacombe, R

    1977-06-01

    When Escherichia coli 30-S ribosomal subunits are hydrolysed under mild conditions, two ribonucleoprotein fragments of unequal size are produced. Knowledge of the RNA sequences contained in these hydrolysis products was required for the experiments described in the preceding paper, and the RNA sub-fragments have therefore been examined by oligonucleotide analysis. Two well-defined small fragments of free RNA, produced concomitantly with the ribonucleoprotein fragments, were also analysed. The larger ribonucleoprotein fragment, containing predominantly proteins S4, S5, S8, S15, S16 (17) and S20, contains a complex mixture of RNA sub-fragments varying from about 100 to 800 nucleotides in length. All these fragments arose from the 5'-terminal 900 nucleotides of 16-S RNA, corresponding to the well-known 12-S fragment. No long-range interactions could be detected within this RNA region in these experiments. The RNA from the smaller ribonucleoprotein fragment (containing proteins S7, S9 S10, S14 and S19) has been described in detail previously, and consists of about 450 nucleotides near the 3' end of the 16-S RNA, but lacking the 3'-terminal 150 nucleotides. The two small free RNA fragments (above) partly account for these missing 150 nucleotides; both fragments arose from section A of the 16-S RNA, but section J (the 3'-terminal 50 nucleotides) was not found. This result suggests that the 3' region of 16-S RNA is not involved in stable interactions with protein.

  9. A ribonucleoprotein fragment of the 30 S ribosome of E. coli containing two contiguous domains of the 16 S RNA.

    PubMed

    Spitnik-Elson, P; Elson, D; Avital, S; Abramowitz, R

    1982-08-11

    Ribonucleoprotein fragments of the 30 S ribosome of E. coli have been prepared by limited ribonuclease digestion and mild heating of the ribosome in a constant ionic environment. One such fragment has been described previously. A second electrophoretically homogeneous fragment has now been isolated and its RNA and protein moieties have been characterized. It contains the 5' half of the 16 S RNA, encompassing domains I and II except for the extreme 5' terminus and several small gaps. Seven proteins are present: S4, S5, S6, S8, S12, S15 and S20. The RNA binding sites of five of these proteins are known, and all are RNA sequences that are present in the fragment. Published neutron scattering and immuno-electron microscopic data indicate that six of the proteins are clustered together in a cross sectional slice through the center of the subunit. After deproteinization, the RNA moiety gives two bands in gel electrophoresis, one containing domains I and II and the other, essentially only domain II. The former, although larger, migrates faster in gel electrophoresis, indicating that RNA domains I and II interact with each other in such a way as to become more compact than domain II by itself.

  10. Deducing the Kinetics of Protein Synthesis In Vivo from the Transition Rates Measured In Vitro

    PubMed Central

    Rudorf, Sophia; Thommen, Michael; Rodnina, Marina V.; Lipowsky, Reinhard

    2014-01-01

    The molecular machinery of life relies on complex multistep processes that involve numerous individual transitions, such as molecular association and dissociation steps, chemical reactions, and mechanical movements. The corresponding transition rates can be typically measured in vitro but not in vivo. Here, we develop a general method to deduce the in-vivo rates from their in-vitro values. The method has two basic components. First, we introduce the kinetic distance, a new concept by which we can quantitatively compare the kinetics of a multistep process in different environments. The kinetic distance depends logarithmically on the transition rates and can be interpreted in terms of the underlying free energy barriers. Second, we minimize the kinetic distance between the in-vitro and the in-vivo process, imposing the constraint that the deduced rates reproduce a known global property such as the overall in-vivo speed. In order to demonstrate the predictive power of our method, we apply it to protein synthesis by ribosomes, a key process of gene expression. We describe the latter process by a codon-specific Markov model with three reaction pathways, corresponding to the initial binding of cognate, near-cognate, and non-cognate tRNA, for which we determine all individual transition rates in vitro. We then predict the in-vivo rates by the constrained minimization procedure and validate these rates by three independent sets of in-vivo data, obtained for codon-dependent translation speeds, codon-specific translation dynamics, and missense error frequencies. In all cases, we find good agreement between theory and experiment without adjusting any fit parameter. The deduced in-vivo rates lead to smaller error frequencies than the known in-vitro rates, primarily by an improved initial selection of tRNA. The method introduced here is relatively simple from a computational point of view and can be applied to any biomolecular process, for which we have detailed information

  11. Family Planning and Preconception Health Among Men in Their Mid-30s: Developing Indicators and Describing Need.

    PubMed

    Casey, Frances E; Sonenstein, Freya L; Astone, Nan M; Pleck, Joseph H; Dariotis, Jacinda K; Marcell, Arik V

    2016-01-01

    The Centers for Disease Control and Prevention and Healthy People 2020 call for improvements in meeting men's reproductive health needs but little is known about the proportion of men in need. This study describes men aged 35 to 39 in need of family planning and preconception care, demographic correlates of these needs, and contraception use among men in need of family planning. Using data from Wave 4 (2008-2010) of the National Survey of Adolescent Males, men were classified in need of family planning and preconception care if they reported sex with a female in the last year and believed that they and their partner were fecund; the former included men who were neither intentionally pregnant nor intending future children and the latter included men intending future children. Men were classified as being in need of both if they reported multiple sex partners in the past year. About 40% of men aged 35 to 39 were in need of family planning and about 33% in need of preconception care with 12% in need of both. Current partner's age, current union type, and sexually transmitted infection health risk differentiated men in need of family planning and preconception care (all ps < .01) and participants' race/ethnicity further differentiated men in need of preconception care (p < .01). More than half of men in need of family planning reported none of the time current partner hormonal use (55%) or condom use (52%) during the past year. This study identified that many men in their mid-30s are in need of family planning or preconception care.

  12. Martian low-altitude magnetic topology deduced from MAVEN/SWEA observations

    NASA Astrophysics Data System (ADS)

    Xu, Shaosui; Mitchell, David; Liemohn, Michael; Fang, Xiaohua; Ma, Yingjuan; Luhmann, Janet; Brain, David; Steckiewicz, Morgane; Mazelle, Christian; Connerney, Jack; Jacosky, Bruce

    2016-10-01

    The Mars Atmosphere and Volatile Evolution (MAVEN) mission for the first time make regular particle and field measurements down to ~150 km altitude. The Solar Wind Electron Analyzer (SWEA) instrument provides 3-D measurements of the electron energy and angular distributions. This study presents the pitch angle-resolved shape parameters that can separate photoelectrons from solar wind electrons, therefore used to deduce the Martian magnetic topology. The three-dimensional view of the magnetic topology is manifested for the first time. The northern hemisphere is found to be dominated by the crustal closed field lines, instead of draped interplanetary magnetic fields (IMF), on the dayside and more day-night connections through cross-terminator closed field lines than in the south. This study can also single out open field lines attached to the dayside ionosphere, which provide possible passage for ion outflow. Magnetic topology governs energetic electrons' movement, thus necessary to understand nightside ionosphere, and aurora.

  13. Wind speeds in two tornadic storms and a tornado, deduced from Doppler Spectra

    SciTech Connect

    Zrnic, D.; Istok, M.

    1980-12-01

    Doppler spectra of a tornado were collected with a radar having a large unambiguous velocity range, +- 91 m s/sup -1/. Thus for the first time a presentation of nonaliased spectra was possible, showing direct measurement of radial velocities. By fitting the tornado model spectrum to data, the radius of maximum winds and tornado center location are deduced. Tornado spectral signature is defined as a double peak, symmetric with respect to the mean wind spectrum. Histograms of maximum measured wind speeds (from spectrum skirts) for two tornadic storms are obtained, and the histograms of velocity difference (between the left and right spectrum skirt) suggest that smaller scale turbulence (<500 m) is principally responsible for spectrum broadness.

  14. Distribution of atomic oxygen in the upper atmosphere deduced from Ogo 6 airglow observations.

    NASA Technical Reports Server (NTRS)

    Donahue, T. M.; Guenther, B.; Thomas, R. J.

    1973-01-01

    The atomic oxygen distribution as a function of altitude between 80 and 120 km and as a function of latitude has been deduced from Ogo 6 557.7-nm airglow photometer data obtained between August 1969 and April 1970. The results indicate that the density ranges from 15 to 50 billion per cu cm at 120 km; that there is a semiannual variation by a factor of 3 in the global average density near 100 km in phase with the satellite drag semiannual effect; and that large latitudinal variations occur with maximums between 40 and 60 deg in the winter hemisphere and sometimes deep minimums in the tropics. The implication of these results for meridional and vertical transport patterns is discussed.

  15. Temperature structure of active regions deduced from helium-like sulphur lines

    NASA Technical Reports Server (NTRS)

    Watanabe, Tetsuya; Hara, Hirohisa; Shimizu, Toshifumi; Hiei, Eijiro; Bentley, Robert D.; Lang, James; Phillips, Kenneth J. H.; Pike, C. David; Fludra, Andrzej; Bromage, Barbara J. I.

    1995-01-01

    Solar active-region temperatures have been determined from the full-Sun spectra of helium-like sulfur (S XV) observed by the Bragg Crystal Spectrometer on Board the Yohkoh satellite. The average temperature deduced from S XV is demonstrated to vary with the solar activity level: A temperature of 2.5 x 10(exp 6) K is derived from the spectra taken during low solar activity, similar to the general corona, while 4 x 10(exp 6) K is obtained during a higher activity phase. For the latter, the high- temperature tail of the differential emission measure of active regions is found most likely due to the superposition of numerous flare-like events (micro/nano-flares).

  16. Optical pressure deduced from energy relations within relativistic formulations of electrodynamics

    NASA Astrophysics Data System (ADS)

    Sheppard, Cheyenne J.; Kemp, Brandon A.

    2014-01-01

    The analysis of plane waves normally incident upon moving media yields a velocity-dependent net flow of electromagnetic energy within the system such that optical pressures are deduced. Two common formulations (Chu and Minkowski) are employed to model the phenomena with respect to the Abraham-Minkowski debate. Within the framework of relativistic electrodynamics, two perfect reflectors submerged in a dielectric are used to compare the calculated optical work and pressure exerted to the system for both formulations via momentum and energy conservation. The perfect reflectors are represented by having zero electric field and zero magnetic field at the surface of the perfect electrical conductor and the perfect magnetic conductor, respectively. Comparison of these results gives valuable insight into the differences between Abraham and Minkowski momenta and provides theoretical evidence as to observable effects in actual optical moment transfer to media.

  17. Characteristics of middle and upper tropospheric clouds as deduced from rawinsonde data

    NASA Technical Reports Server (NTRS)

    Starr, D. D. O.; Cox, S. K.

    1982-01-01

    The static environment of middle and upper tropospheric clouds is characterized. Computed relative humidity with respect to ice is used to diagnose the presence of cloud layer. The deduced seasonal mean cloud cover estimates based on this technique are shown to be reasonable. The cases are stratified by season and pressure thickness, and the dry static stability, vertical wind speed shear, and Richardson number are computed for three layers for each case. Mean values for each parameter are presented for each stratification and layer. The relative frequency of occurrence of various structures is presented for each stratification. The observed values of each parameter and the observed structure of each parameter are quite variable. Structures corresponding to any of a number of different conceptual models may be found. Moist adiabatic conditions are not commonly observed and the stratification based on thickness yields substantially different results for each group.

  18. Atmospheric density variations at 140 kilometers deduced from precise satellite radar tracking data.

    NASA Technical Reports Server (NTRS)

    Devries, L. L.; Schusterman, L.; Bruce, R. W.

    1972-01-01

    Discussion of the technique of evaluating density values from precise radar-tracking data of satellites in the altitude region from 130 to 140 km. Inclinations of these satellites were between 106 and 112 deg. A detailed examination of all elements of the density-reduction techniques was conducted, and consideration was given to recent advances in geodesy, drag-coefficient modeling, and orbit-determination techniques. Ten days of high-resolution density data deduced from orbital decay of each of three satellites are presented. Three types of density variations at 140 km are discernible in these data: periodic daily density variations with a density amplitude of about 10%; density increases of up to 35% associated with enhanced geomagnetic activity during which the planetary geomagnetic index Kp reached a value of 8 units; and an observed semiannual variation of about 20%, which indicates a total semiannual variation of 35 to 40%.

  19. Behaviour of the Pleistocene marsupial lion deduced from claw marks in a southwestern Australian cave

    PubMed Central

    Arman, Samuel D.; Prideaux, Gavin J.

    2016-01-01

    The marsupial lion, Thylacoleo carnifex, was the largest-ever marsupial carnivore, and is one of the most iconic extinct Australian vertebrates. With a highly-specialised dentition, powerful forelimbs and a robust build, its overall morphology is not approached by any other mammal. However, despite >150 years of attention, fundamental aspects of its biology remain unresolved. Here we analyse an assemblage of claw marks preserved on surfaces in a cave and deduce that they were generated by marsupial lions. The distribution and skewed size range of claw marks within the cave elucidate two key aspects of marsupial lion biology: they were excellent climbers and reared young in caves. Scrutiny of >10,000 co-located Pleistocene bones reveals few if any marsupial lion tooth marks, which dovetails with the morphology-based interpretation of the species as a flesh specialist. PMID:26876952

  20. Behaviour of the Pleistocene marsupial lion deduced from claw marks in a southwestern Australian cave.

    PubMed

    Arman, Samuel D; Prideaux, Gavin J

    2016-02-15

    The marsupial lion, Thylacoleo carnifex, was the largest-ever marsupial carnivore, and is one of the most iconic extinct Australian vertebrates. With a highly-specialised dentition, powerful forelimbs and a robust build, its overall morphology is not approached by any other mammal. However, despite >150 years of attention, fundamental aspects of its biology remain unresolved. Here we analyse an assemblage of claw marks preserved on surfaces in a cave and deduce that they were generated by marsupial lions. The distribution and skewed size range of claw marks within the cave elucidate two key aspects of marsupial lion biology: they were excellent climbers and reared young in caves. Scrutiny of >10,000 co-located Pleistocene bones reveals few if any marsupial lion tooth marks, which dovetails with the morphology-based interpretation of the species as a flesh specialist.

  1. Behaviour of the Pleistocene marsupial lion deduced from claw marks in a southwestern Australian cave.

    PubMed

    Arman, Samuel D; Prideaux, Gavin J

    2016-01-01

    The marsupial lion, Thylacoleo carnifex, was the largest-ever marsupial carnivore, and is one of the most iconic extinct Australian vertebrates. With a highly-specialised dentition, powerful forelimbs and a robust build, its overall morphology is not approached by any other mammal. However, despite >150 years of attention, fundamental aspects of its biology remain unresolved. Here we analyse an assemblage of claw marks preserved on surfaces in a cave and deduce that they were generated by marsupial lions. The distribution and skewed size range of claw marks within the cave elucidate two key aspects of marsupial lion biology: they were excellent climbers and reared young in caves. Scrutiny of >10,000 co-located Pleistocene bones reveals few if any marsupial lion tooth marks, which dovetails with the morphology-based interpretation of the species as a flesh specialist. PMID:26876952

  2. Primary structure of the 5 S subunit of transcarboxylase as deduced from the genomic DNA sequence.

    PubMed

    Thornton, C G; Kumar, G K; Shenoy, B C; Haase, F C; Phillips, N F; Park, V M; Magner, W J; Hejlik, D P; Wood, H G; Samols, D

    1993-09-13

    Transcarboxylase from Propionibacterium shermanii is a complex biotin-containing enzyme composed of 30 polypeptides of three different types. It is composed of six dimeric outer subunits associated with a central cylindrical hexameric subunit through 12 biotinyl subunits; three outer subunits on each face of the central hexamer. Each outer dimer is termed a 5 S subunit which associates with two biotinyl subunits. The enzyme catalyzes a two-step reaction in which methylmalonyl-CoA and pyruvate form propionyl-CoA and oxalacetate, the 5 S subunit specifically catalyzing one of these reactions. We report here the cloning, sequencing and expression of the monomer of the 5 S subunit. The gene was identified by matching amino acid sequences derived from isolated authentic 5 S peptides with the deduced sequence of an open reading frame present on a cloned P. shermanii genomic fragment known to contain the gene encoding the 1.3 S biotinyl subunit. The cloned 5 S gene encodes a protein of 519 amino acids, M(r) 57,793. The deduced sequence shows regions of extensive homology with that of pyruvate carboxylase and oxalacetate decarboxylase, two enzymes which catalyze the same or reverse reaction. A fragment was subcloned into pUC19 in an orientation such that the 5 S open reading frame could be expressed from the lac promoter of the vector. Crude extracts prepared from these cells contained an immunoreactive band on Western blots which co-migrated with authentic 5 S and were fully active in catalyzing the 5 S partial reaction. We conclude that we have cloned, sequenced and expressed the monomer of the 5 S subunit and that the expressed product is catalytically active. PMID:8365490

  3. Function of individual 30S subunit proteins of Escherichia coli. Effect of specific immunoglobulin fragments (Fab) on activities of ribosomal decoding sites.

    PubMed

    Lelong, J C; Gros, D; Gros, F; Bollen, A; Maschler, R; Stöffler, G

    1974-02-01

    Specific anti-30S protein immunoglobulin G fragments (Fab) were used to determine the contribution of each of the 30S ribosomal proteins to: (1) polyphenylalanine synthesis, (2) initiation factor-dependent binding of fMet-tRNA, (3) T-factor-dependent binding of phenylalanyl-tRNA, and (4) fixation of radioactive dihydrostreptomycin. Twenty of the 21 possible antibodies (antibody against S17 excepted) were used. In conditions where all the 30S proteins were accessible to Fabs, all of these monovalent antibodies strongly inhibited polyphenylalanine synthesis in vitro. Antibodies against S4, S6, S7, S12, S15, and S16, however, showed a weaker effect.30S proteins can be classified into four categories by their contributions to the function of sites "A" and "P": class I appears nonessential for tRNA positioning at either site (S4, S7, S15, and S16); class II includes proteins whose role in initiation is critical (S2, S5, S6, S12, and S13); class III (S8, S9, S11, and S18) corresponds to proteins whose blockade prevents internal (elongation factor Tudependent) positioning; and class IV includes entities that are essential for activities of both "A" and "P" sites (S1, S3, S10, S14, S19, S20, and S21). Dihydrostreptomycin fixation to the 30S or 70S ribosomes was inhibited by antibodies against S1, S10, S11, S18, S19, S20, and S21, but only weakly by the anti-S12 (Str A protein) Fab. The significance of these results is discussed in relation to 30S protein function, heterogeneity, and topography.

  4. The identification of spermine binding sites in 16S rRNA allows interpretation of the spermine effect on ribosomal 30S subunit functions

    PubMed Central

    Amarantos, Ioannis; Zarkadis, Ioannis K.; Kalpaxis, Dimitrios L.

    2002-01-01

    A photoreactive analogue of spermine, N1-azidobenzamidino (ABA)-spermine, was covalently attached after irradiation to Escherichia coli 30S ribosomal subunits or naked 16S rRNA. By means of RNase H digestion and primer extension, the cross-linking sites of ABA-spermine in naked 16S rRNA were characterised and compared with those identified in 30S subunits. The 5′ domain, the internal and terminal loops of helix H24, as well as the upper part of helix H44 in naked 16S rRNA, were found to be preferable binding sites for polyamines. Association of 16S rRNA with ribosomal proteins facilitated its interaction with photoprobe, except for 530 stem–loop nt, whose modification by ABA-spermine was abolished. Association of 30S with 50S subunits, poly(U) and AcPhe-tRNA (complex C) further altered the susceptibility of ABA-spermine cross-linking to 16S rRNA. Complex C, modified in its 30S subunit by ABA-spermine, reacted with puromycin similarly to non-photolabelled complex. On the contrary, poly(U)-programmed 70S ribosomes reconstituted from photolabelled 30S subunits and untreated 50S subunits bound AcPhe-tRNA more efficiently than untreated ribosomes, but were less able to recognise and reject near cognate aminoacyl-tRNA. The above can be interpreted in terms of conformational changes in 16S rRNA, induced by the incorporation of ABA-spermine. PMID:12087167

  5. Structural features of cartilage matrix protein deduced from cDNA.

    PubMed Central

    Argraves, W S; Deák, F; Sparks, K J; Kiss, I; Goetinck, P F

    1987-01-01

    cDNAs encoding the Mr 54,000 chicken cartilage matrix protein (CMP) were selected from a cartilage cDNA expression library by immunological means. Antibodies elicited against insert-encoded protein purified from one of the clones reacted specifically with chicken CMP in immunoblots of total cartilage extract, providing positive identification of the cDNA clones isolated. The cDNAs detect a 3.4-kilobase transcript that was present in sternal cartilage and in cartilaginous but not in precartilaginous embryonic limb tissues. The cDNAs code for 416 amino acids of the chicken CMP, including its COOH terminus. There are two striking features in the deduced CMP amino acid sequence: first, it contains a region with significant homologies to repeat sequences in the precursor for epidermal growth factor; and second, it is made up of two large homologous repeat sequences. These results provide the first detailed structural information on the CMP and establish it as a developmentally regulated marker of cartilage differentiation. Images PMID:3025875

  6. Deducing the 237U(n,f) cross-section using the Surrogate Ratio Method

    SciTech Connect

    Burke, J T; Bernstein, L A; Escher, J; Ahle, L; Church, J A; Dietrich, F S; Moody, K J; Norman, E B; Phair, L; Fallon, P; Clark, R M; Deleplanque, M A; Descovich, M; Cromaz, M; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Stephens, F S; Ai, H; Beausang, C; Cridder, B

    2005-12-29

    The authors have deduced the cross section for {sup 237}U(n,f) over an equivalent neutron energy range from 0 to 20 MeV using the Surrogate Ratio method. A 55 MeV {sup 4}He beam from the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions: {sup 238}U({alpha},{alpha}{prime}f) and {sup 236}U({alpha},{alpha}{prime}f). The {sup 238}U reaction was a surrogate for {sup 237}U(n,f) and the {sup 236}U reaction was used as a surrogate for {sup 235}U(n,f). Scattered alpha particles were detected in a fully depleted segmented silicon telescope array (STARS) over an angle range of 35{sup o} to 60{sup o} with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106{sup o} and 131{sup o}.

  7. Chemical composition of the Howardite Parent Body deduced from Kapoeta primary 'mafic' magmas

    NASA Technical Reports Server (NTRS)

    Smith, M. R.; Schmitt, R. A.

    1982-01-01

    Chemical data are presented for three 'mafic' clasts extracted from the Kapoeta howardite. Bulk compositions and petrologic observations suggest that two of these lithic clasts represent olivine-plagioclase bearing orthopyroxenites. Chondrite-relative refractory large ion lithophile abundances of two of the clasts are inferred to represent primary Mg-rich magmas produced by extensive (greater than about 70%) partial melting of a source composition indistinguishable from the silicate fraction of average CH-CL ordinary chondrites, with the exception of the depletion of the alkalis Na and K by a factor of 13 + or - 1 in the source composition. A metal-free and volatile depleted Kapoeta Parent Body (KPB) is subsequently deduced and is shown to compare very well with other similarly derived Achondrite Parent Body and Howardite Parent Body estimates but not to parent body estimates derived from inferences based on eucrite phase equilibrium studies. Other implications suggest that the KPB is heterogeneous with respect to Fe/Mg ratios.

  8. Hysteresis Loop for a No-loaded, Delta-connected Transformer Model Deduced from Measurements

    NASA Astrophysics Data System (ADS)

    Corrodi, Yves; Kamei, Kenji; Kohyama, Haruhiko; Ito, Hiroki

    At a transformer's steady-state condition, whereby a transformer and its load are constantly supplied by a sinusoidal source, the current-flux pair within the transformer core and its windings will cycle along a hysteresis loop. This nonlinear current-flux characteristic becomes important while at transformer gets reenergized. A remaining residual flux and the fact that a transformer is typically used up to its saturation level can lead to high-amplitude magnetizing inrush currents and associated voltage disturbances. These disturbances can be reduced by controlled transformer switching. In order to pre-evaluate the effect of a specific controlled transformer energization, pre-simulations can be applied. In that case the hysteresis loop and its saturation characteristic will become the most important model parameter. If the corresponding manufacturer specifications are not available a standard hysteresis loops can be used, but might come up with an inaccurate simulation result. Therefore, this paper analyses the measured 3-phase currents from two delta-connected power transformers by “Fourier Series” in order to deduce a single-phase hysteresis loop, which can be implemented into a typical 3-phase transformer model. Additionally, the saturation behavior of a power-transformer will be estimated and a comparison of ATP/EMTP simulations will conclude this paper.

  9. Relations between aliphatics and silicate components in 12 stratospheric particles deduced from vibrational spectroscopy

    SciTech Connect

    Merouane, S.; Djouadi, Z.; Le Sergeant d'Hendecourt, L.

    2014-01-10

    Interplanetary dust particles (IDPs) are among the most pristine extraterrestrial samples available in the laboratory for analyses with moderate to high spatial- and spectral-resolution spectroscopic techniques. Their composition can provide precious information on the early stages of the solar nebula as well as on the processes on the surfaces of different small bodies in the solar system from which IDPs originate. In this work, we have analyzed six anhydrous IDPs and six stratospheric particles possibly of cosmic origin through infrared (IR) and Raman micro-spectroscopy to study and investigate their silicate and organic components. We find that the length/ramification of the aliphatic organics given by the CH{sub 2}/CH{sub 3} ratios in the IDPs is closely linked to the silicate family (pyroxene or olivine) present in the samples. Both IR and Raman data suggest that this relation is not correlated with either aqueous (as evidenced by the absence of aqueous related minerals) or thermal processes (as deduced from Raman measurements). Therefore, this observation might be related to the initial path of formation of the organics on the silicate surfaces, thus tracing a possible catalytic role that silicates would play in the formation and/or ramification of organic matter in the primitive nebula.

  10. The Seismic risk perception in Italy deduced by a statistical sample

    NASA Astrophysics Data System (ADS)

    Crescimbene, Massimo; La Longa, Federica; Camassi, Romano; Pino, Nicola Alessandro; Pessina, Vera; Peruzza, Laura; Cerbara, Loredana; Crescimbene, Cristiana

    2015-04-01

    In 2014 EGU Assembly we presented the results of a web a survey on the perception of seismic risk in Italy. The data were derived from over 8,500 questionnaires coming from all Italian regions. Our questionnaire was built by using the semantic differential method (Osgood et al. 1957) with a seven points Likert scale. The questionnaire is inspired the main theoretical approaches of risk perception (psychometric paradigm, cultural theory, etc.) .The results were promising and seem to clearly indicate an underestimation of seismic risk by the italian population. Based on these promising results, the DPC has funded our research for the second year. In 2015 EGU Assembly we present the results of a new survey deduced by an italian statistical sample. The importance of statistical significance at national scale was also suggested by ISTAT (Italian Statistic Institute), considering the study as of national interest, accepted the "project on the perception of seismic risk" as a pilot study inside the National Statistical System (SISTAN), encouraging our RU to proceed in this direction. The survey was conducted by a company specialised in population surveys using the CATI method (computer assisted telephone interview). Preliminary results will be discussed. The statistical support was provided by the research partner CNR-IRPPS. This research is funded by Italian Civil Protection Department (DPC).

  11. Relative stability and magic numbers of nuclei deduced from behavior of cluster emission half-lives

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Seif, W. M.; Abdurrahman, A.

    2016-08-01

    We calculated the half-life times (Tc) of the 14C, 20O, 20Ne, and 24Ne cluster emissions from heavy and superheavy nuclei. The variation of Tc with the neutron and proton numbers of daughter nuclei is studied to determine the minima in log10Tc at each neutron number for different daughter isotones. We found that each minimum for a given isotone corresponds to neutron magicity already indicated by other approaches. The proton numbers at neutron magic numbers were found to be also proton magic numbers or differ slightly from them. We arranged the different isotones at each neutron magic number according to their stability in the sense that the more stable daughter isotone corresponds to the lowest value of log10Tc . The magic neutron numbers predicted by the present study are N =126 , 148, 152, 154, 160, 162, 172, 176, 178, 180, 182, 184, and 200. The predicted magic proton numbers are Z =82 , 98, 100 102, 106, 108, 114, and 116. The values of N and Z mentioned above agree with magic numbers deduced in other studies.

  12. Interplanetary Magnetic Field Line Mixing Deduced from Impulsive Solar Flare Particles.

    PubMed

    Mazur; Mason; Dwyer; Giacalone; Jokipii; Stone

    2000-03-20

    We have studied fine-scale temporal variations in the arrival profiles of approximately 20 keV nucleon-1 to approximately 2 MeV nucleon-1 ions from impulsive solar flares using instrumentation on board the Advanced Composition Explorer spacecraft at 1 AU between 1997 November and 1999 July. The particle events often had short-timescale ( approximately 3 hr) variations in their intensity that occurred simultaneously across all energies and were generally not in coincidence with any local magnetic field or plasma signature. These features appear to be caused by the convection of magnetic flux tubes past the observer that are alternately filled and devoid of flare ions even though they had a common flare source at the Sun. Thus, we have used the particles to study the mixing of the interplanetary magnetic field that is due to random walk. We deduce an average timescale of 3.2 hr for these features, which corresponds to a length of approximately 0.03 AU.

  13. Atmospheric emissions and trends of nitrous oxide deduced from 10 years of ALE-GAGE data

    NASA Technical Reports Server (NTRS)

    Prinn, R.; Cunnold, D.; Alyea, F.; Rasmussen, R.; Simmonds, P.

    1990-01-01

    Long-term measurements of nitrous oxide (N2O) obtained during the Atmospheric Lifetime Experiment (ALE) and the Global Atmospheric Gases Experiment (GAGE) for a period from 1978 to 1988 are presented and interpreted. It is observed that the average concentration in the Northern Hemisphere is 0.75 +/- 0.16 ppbv higher than in the Southern Hemisphere and that the global average linear trend in N2O lies in the range from 0.25 to 0.31 percent/year. The measured trends and latitudinal distributions are shown to be consistent with the hypothesis that stratospheric photodissociation is the major atmospheric sink for N2O, while the cause of the N2O trend is suggested to be a combination of a growing tropical source and a growing Northern mid-latitude source. A 10-year average global N2O emission rate of (20.5 +/- 2.4) x 10 to the 12th g N2O/year is deduced from the ALE/GAGE data.

  14. Stratospheric aerosol acidity, density, and refractive index deduced from SAGE 2 and NMC temperature data

    NASA Technical Reports Server (NTRS)

    Yue, G. K.; Poole, L. R.; Wang, P.-H.; Chiou, E. W.

    1994-01-01

    Water vapor concentrations obtained by the Stratospheric Aerosol and Gas Experiment 2 (SAGE 2) and collocated temperatures provided by the National Meteorological Center (NMC) from 1986 to 1990 are used to deduce seasonally and zonally averaged acidity, density, and refractive index of stratospheric aerosols. It is found that the weight percentage of sulfuric acid in the aerosols increases from about 60 just above the tropopause to about 86 at 35 km. The density increases from about 1.55 to 1.85 g/cu cm between the same altitude limits. Some seasonal variations of composition and density are evident at high latitudes. The refractive indices at 1.02, 0.694, and 0.532 micrometers increase, respectively, from about 1.425, 1.430, and 1.435 just above the tropopause to about 1.445, 1.455, and 1.458 at altitudes above 27 km, depending on the season and latitude. The aerosol properties presented can be used in models to study the effectiveness of heterogeneous chemistry, the mass loading of stratospheric aerosols, and the extinction and backscatter of aerosols at different wavelengths. Computed aerosol surface areas, rate coefficients for the heterogeneous reaction ClONO2 + H2O yields HOCl + HNO3 and aerosol mass concentrations before and after the Pinatubo eruption in June 1991 are shown as sample applications.

  15. Deducing the 237U(n,f) cross-section using the Surrogate Ratio Method

    SciTech Connect

    Burke, J T; Bernstein, L A; Escher, J; Ahle, L; Church, J A; Dietrich, F; Moody, K J; Norman, E B; Phair, L W; Fallon, P; Clark, R; Delaplanque, M; Descovich, M; Cromaz, M; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Stephens, F S

    2005-08-16

    The authors have deduced the {sup 237}U(n,f) cross-section over an equivalent neutron energy range of 0 to 20 MeV using the Surrogate Ratio method. A 55 MeV {sup 4}He{sup 2+} beam from the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions {sup 238}U({alpha},{alpha}'f) and {sup 236}U({alpha},{alpha}'f). The {sup 238}U reaction was a surrogate for {sup 237}U(n,f) and the {sup 236}U reaction was used as a surrogate for {sup 235}U(n,f). The energies of the scattered alpha particles were detected in a fully depleted segmented silicon telescope array (STARS) over an angle range of 35{sup o} to 60{sup o} with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106{sup o} to 131{sup o}.

  16. Thin cirrus clouds - Seasonal distribution over oceans deduced from Nimbus-4 IRIS

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Fraser, R. S.; Dalu, G.; Wu, Man-Li C.; Curran, R. J.

    1988-01-01

    Spectral differences in the extinction of the 10.8- and 12.6-micron bands of the IR window region, due to optically thin clouds, were found in the measurements made by both an airborne broadband IR radiometer and the IR interferometer spectrometer (IRIS) aboard the Nimbus-4 satellite; the extinction at 12.6 microns was significantly larger than that at 10.8 microns; both water and ice particles in the clouds can account for such spectral difference in extinction. Multiple scattering radiative transfer calculations of IRIS data revealed this spectral feature about 100 to 20 km away from the high-altitude cold clouds; it is assumed that this feature is related to the spreading of cirrus clouds. Based on this assumption, mean seasonal maps of the distribution of thin cirrus clouds over the oceans were deduced from the IRIS data. The maps show that such clouds are often present over the convectively active areas, such as ITCZ, SPCZ, and the Bay of Bengal during the summer monsoon.

  17. The use of the experimentally deduced Brunt-Vaisala frequency and turbulent velocity fluctuations to estimate the eddy diffusion coefficient

    NASA Technical Reports Server (NTRS)

    Rottger, J.

    1986-01-01

    The determination of the turbulent energy dissipation rate or the eddy diffusion coefficient from radar observations can be done through the turbulence refractive index structure constant, deduced from calibrated echo power measurements, or through the turbulent velocity fluctuations, deduced from the echo spectrum width. Besides the radar parameters, power and spectrum width, the first approach needs knowledge of profiles of temperature and electron density in the mesosphere and the fraction of the radar volume filled with turbulence. The latter approach needs knowledge of the temperature profile, namely, the Brunt-Vaisala frequency. The use of this latter approach is demonstrated.

  18. Deducing Anomalous Wave Source Regions during the Life Cycles of Persistent Flow Anomalies.

    NASA Astrophysics Data System (ADS)

    Black, Robert X.

    1997-04-01

    Anomalous wave source regions are identified during the life cycles of persistent flow anomalies occurring over the North Pacific and North Atlantic Oceans during boreal winter. These cases project strongly upon the Pacific-North American and Eastern Atlantic teleconnection patterns, respectively, and represent two of the primary modes of intraseasonal low frequency variability in the Northern Hemisphere wintertime circulation. In the upper troposphere, these cases are manifested by wave trains of large-scale and large amplitude flow anomalies extending downstream from key regions near the Aleutian Islands and south of Iceland, respectively. The occurrence of persistent flow anomalies is closely linked to persistent extremes in surface weather and to variations in the skill of extended-range weather forecasts. Black and Dole performed a detailed diagnostic analysis of the onset of persistent cyclonic flow anomalies over the North Pacific. A key result of their study was that wave activity flux diagnoses correctly identified the location of anomalous wave source regions.Black and Dole's study is extended by diagnosing three-dimensional fluxes of wave activity during the onset, maintenance, and decay of cyclonic and anticyclonic persistent flow anomalies over the North Atlantic and North Pacific regions. The flux characterizes large-scale wave propagation, and the flux divergence is used to deduce the location of regional sources and sinks of anomalous wave activity. In all cases there is a marked upward and downstream flux of wave activity emanating from the lower troposphere near the key region. The results are consistent with a local wave source and Rossby-like wave propagation away from the source. There is little evidence that anomalous remote processes directly force persistent flow anomaly life cycles. The diagnostic analyses indicate that the primary anomalous wave sources for both cyclonic and anticyclonic persistent flow anomalies are local to the region of

  19. A novel computational framework for deducing muscle synergies from experimental joint moments

    PubMed Central

    Gopalakrishnan, Anantharaman; Modenese, Luca; Phillips, Andrew T. M.

    2014-01-01

    Prior experimental studies have hypothesized the existence of a “muscle synergy” based control scheme for producing limb movements and locomotion in vertebrates. Such synergies have been suggested to consist of fixed muscle grouping schemes with the co-activation of all muscles in a synergy resulting in limb movement. Quantitative representations of these groupings (termed muscle weightings) and their control signals (termed synergy controls) have traditionally been derived by the factorization of experimentally measured EMG. This study presents a novel approach for deducing these weightings and controls from inverse dynamic joint moments that are computed from an alternative set of experimental measurements—movement kinematics and kinetics. This technique was applied to joint moments for healthy human walking at 0.7 and 1.7 m/s, and two sets of “simulated” synergies were computed based on two different criteria (1) synergies were required to minimize errors between experimental and simulated joint moments in a musculoskeletal model (pure-synergy solution) (2) along with minimizing joint moment errors, synergies also minimized muscle activation levels (optimal-synergy solution). On comparing the two solutions, it was observed that the introduction of optimality requirements (optimal-synergy) to a control strategy solely aimed at reproducing the joint moments (pure-synergy) did not necessitate major changes in the muscle grouping within synergies or the temporal profiles of synergy control signals. Synergies from both the simulated solutions exhibited many similarities to EMG derived synergies from a previously published study, thus implying that the analysis of the two different types of experimental data reveals similar, underlying synergy structures. PMID:25520645

  20. Deducing Electronic Unit Internal Response During a Vibration Test Using a Lumped Parameter Modeling Approach

    NASA Technical Reports Server (NTRS)

    Van Dyke, Michael B.

    2014-01-01

    During random vibration testing of electronic boxes there is often a desire to know the dynamic response of certain internal printed wiring boards (PWBs) for the purpose of monitoring the response of sensitive hardware or for post-test forensic analysis in support of anomaly investigation. Due to restrictions on internally mounted accelerometers for most flight hardware there is usually no means to empirically observe the internal dynamics of the unit, so one must resort to crude and highly uncertain approximations. One common practice is to apply Miles Equation, which does not account for the coupled response of the board in the chassis, resulting in significant over- or under-prediction. This paper explores the application of simple multiple-degree-of-freedom lumped parameter modeling to predict the coupled random vibration response of the PWBs in their fundamental modes of vibration. A simple tool using this approach could be used during or following a random vibration test to interpret vibration test data from a single external chassis measurement to deduce internal board dynamics by means of a rapid correlation analysis. Such a tool might also be useful in early design stages as a supplemental analysis to a more detailed finite element analysis to quickly prototype and analyze the dynamics of various design iterations. After developing the theoretical basis, a lumped parameter modeling approach is applied to an electronic unit for which both external and internal test vibration response measurements are available for direct comparison. Reasonable correlation of the results demonstrates the potential viability of such an approach. Further development of the preliminary approach presented in this paper will involve correlation with detailed finite element models and additional relevant test data.

  1. Deducing growth mechanisms for minerals from the shapes of crystal size distributions

    USGS Publications Warehouse

    Eberl, D.D.; Drits, V.A.; Srodon, J.

    1998-01-01

    Crystal size distributions (CSDs) of natural and synthetic samples are observed to have several distinct and different shapes. We have simulated these CSDs using three simple equations: the Law of Proportionate Effect (LPE), a mass balance equation, and equations for Ostwald ripening. The following crystal growth mechanisms are simulated using these equations and their modifications: (1) continuous nucleation and growth in an open system, during which crystals nucleate at either a constant, decaying, or accelerating nucleation rate, and then grow according to the LPE; (2) surface-controlled growth in an open system, during which crystals grow with an essentially unlimited supply of nutrients according to the LPE; (3) supply-controlled growth in an open system, during which crystals grow with a specified, limited supply of nutrients according to the LPE; (4) supply- or surface-controlled Ostwald ripening in a closed system, during which the relative rate of crystal dissolution and growth is controlled by differences in specific surface area and by diffusion rate; and (5) supply-controlled random ripening in a closed system, during which the rate of crystal dissolution and growth is random with respect to specific surface area. Each of these mechanisms affects the shapes of CSDs. For example, mechanism (1) above with a constant nucleation rate yields asymptotically-shaped CSDs for which the variance of the natural logarithms of the crystal sizes (??2) increases exponentially with the mean of the natural logarithms of the sizes (??). Mechanism (2) yields lognormally-shaped CSDs, for which ??2 increases linearly with ??, whereas mechanisms (3) and (5) do not change the shapes of CSDs, with ??2 remaining constant with increasing ??. During supply-controlled Ostwald ripening (4), initial lognormally-shaped CSDs become more symmetric, with ??2 decreasing with increasing ??. Thus, crystal growth mechanisms often can be deduced by noting trends in ?? versus ??2 of CSDs for

  2. Spokes in Saturn's B Ring: dynamical and physical properties deduced from Voyager Saturn Ring images

    SciTech Connect

    Eplee, R.E.

    1987-01-01

    This project studied dynamical and physical properties of spokes as deduced from Voyage Saturn ring images. Analysis of the orbital motion of two dynamically-anomalous spokes, in particular, set limits on the charge-to-mass ratios of spoke particles at various times during their dynamical evolution. These two spokes have charge-to-mass of at least -60 +/- 3 C kg/sup -1/ while corotating with Saturn, and charge-to-mass ratios of no more than -22 +/- 2 C kg/sup -1/ while orbiting Saturn at Keplerian velocities. Additionally, charge decay on the grains of these spokes, caused by solar UV photoemission, allowed a lower limit of 0.10 +/- 0.03 ..mu..m to be placed on the range of radii for spoke particles. In a study of spoke photometry, a single-scattering analysis of the 0.470-..mu..m phase function for spokes has set a mean radius for the dominant scatterers (at this wavelength) of 0.22 +/- 0.02 /sup +/m. The transport of angular momentum within the rings due to the radial motion of spoke grains is shown to be the most-significant effect of spoke activity on the dynamical evolution of the B Ring, as was predicted by Goertz et al. (1986, Nature 320, 141-143). The radial mass-transport velocity due to highly-charged spokes is -1 x 10/sup -9/m s/sup -1/. The subsequent spreading time for the B Ring is 600 million years, which is significantly less than the 4.6 billion-year age of the solar system.

  3. Deducing logical relationships between spatially registered cortical parcellations under conditions of uncertainty.

    PubMed

    Bezgin, Gleb; Wanke, Egon; Krumnack, Antje; Kötter, Rolf

    2008-10-01

    We propose a new technique, called Spatial Objective Relational Transformation (SORT), as an automated approach for derivation of logical relationships between cortical areas in different brain maps registered in the same Euclidean space. Recently, there have been large amounts of voxel-based three-dimensional structural and functional imaging data that provide us with coordinate-based information about the location of differently defined areas in the brain, whereas coordinate-independent, parcellation-based mapping is still commonly used in the majority of animal tracing and mapping studies. Because of the impact of voxel-based imaging methods and the need to attribute their features to coordinate-independent brain entities, this mapping becomes increasingly important. Our motivation here is not to make vague statements where more precise spatial statements would be better, but to find criteria for the identity (or other logical relationships) between areas that were delineated by different methods, in different individuals, or mapped to three-dimensional space using different deformation algorithms. The relevance of this problem becomes immediately obvious as one superimposes and compares different datasets in multimodal databases (e.g. CARET, http://brainmap.wustl.edu/caret), where voxel-based data are registered to surface nodes exploited by the procedure presented here. We describe the SORT algorithm and its implementation in the Java 2 programming language (http://java.sun.com/, which we make available for download. We give an example of practical use of our approach, and validate the SORT approach against a database of the coordinate-independent statements and inferences that have been deduced using alternative techniques.

  4. Characteristics of F-region dynamo currents deduced from CHAMP magnetic field measurements

    NASA Astrophysics Data System (ADS)

    Park, Jaeheung; Lühr, Hermann; Min, Kyoung Wook

    2010-10-01

    Using magnetic field observations of the CHAMP satellite we provide the first comprehensive study of F-region dynamo currents as a function of season, local time, geographic longitude, and solar activity. From bipolar variations of the zonal magnetic field component the density of vertical current driven by the F-region dynamo is deduced. The current strength is smallest around June solstice, which is attributed to a reduced F-region Pedersen conductance caused by a lower electron density and neutral density at that season. During the hours around noon highest current densities are observed. They are flowing downward over the dip equator. A secondary peak of upward currents appears at dusk. The polarity switch occurs between15 and 16 (local time) independent of season. The noontime F-region dynamo current peaks at longitudes connected to the South Atlantic Anomaly, which can be explained by the enhanced conductivity in the region of reduced B field. The F-region current at dusk exhibits no peak in the longitude sector of the South Atlantic Anomaly. At noon, the F-region dynamo currents exhibit a wave 4 longitudinal structure during equinoxes and June solstice. The wave 4 signature becomes weak during December solstice. At dusk the wave 4 signature of F-region dynamo currents is much reduced in all seasons. This behavior can be explained by the DE3 tidal signature in the zonal wind at CHAMP altitude. F-region dynamo currents increase linearly with the solar flux index, F10.7, during both noon and dusk time sectors. The increase in current strength with increasing F10.7 is slightly higher at dusk than at noon.

  5. High level of skeletal muscle carnosine contributes to the latter half of exercise performance during 30-s maximal cycle ergometer sprinting.

    PubMed

    Suzuki, Yasuhiro; Ito, Osamu; Mukai, Naoki; Takahashi, Hideyuki; Takamatsu, Kaoru

    2002-04-01

    The histidine-containing dipeptide carnosine (beta-alanyl-L-histidine) has been shown to significantly contribute to the physicochemical buffering in skeletal muscles, which maintains acid-base balance when a large quantity of H(+) is produced in association with lactic acid accumulation during high-intensity exercise. The purpose of the present study was to examine the relations among the skeletal muscle carnosine concentration, fiber-type distribution, and high-intensity exercise performance. The subjects were 11 healthy men. Muscle biopsy samples were taken from the vastus lateralis at rest. The carnosine concentration was determined by the use of an amino acid autoanalyzer. The fiber-type distribution was determined by the staining intensity of myosin adenosinetriphosphatase. The high-intensity exercise performance was assessed by the use of 30-s maximal cycle ergometer sprinting. A significant correlation was demonstrated between the carnosine concentration and the type IIX fiber composition (r=0.646, p<0.05). The carnosine concentration was significantly correlated with the mean power per body mass (r=0.785, p<0.01) during the 30-s sprinting. When dividing the sprinting into 6 phases (0-5, 6-10, 11-15, 16-20, 21-25, 26-30 s), significant correlations were observed between the carnosine concentration and the mean power per body mass of the final 2 phases (21-25 s: r=0.694, p<0.05; 26-30 s: r=0.660, p<0.05). These results indicated that the carnosine concentration could be an important factor in determining the high-intensity exercise performance.

  6. Assembly of the 30S subunit from Escherichia coli ribosomes occurs via two assembly domains which are initiated by S4 and S7.

    PubMed

    Nowotny, V; Nierhaus, K H

    1988-09-01

    A protein which initiates assembly of ribosomes is defined as a protein which binds to the respective rRNA without cooperativity (i.e., without the help of other proteins) during the onset of assembly and is essential for the formation of active ribosomal subunits. The number of proteins binding without cooperativity was determined by monitoring the reconstitution output of active particles at various inputs of 16S rRNA, in the presence of constant amounts of 30S-derived proteins (TP30): This showed that only two of the proteins of the 30S subunit are assembly-initiator proteins. These two proteins are still present on a LiCl core particle comprising 16S rRNA and 12 proteins (including minor proteins). The 12 proteins were isolated, and a series of reconstitution experiments at various levels of rRNA excess demonstrated that S4 and S7 are the initiator proteins. Pulse-chase experiments performed during the early assembly with 14C- and 3H-labeled TP30 and the determination of the 14C/3H ratio of the individual proteins within the assembled particles revealed a bilobal structure of the 30S assembly: A group of six proteins headed by S4 (namely, S4, S20, S16, S15, S6, and S18) resisted the chasing most efficiently (S4 assembly domain). None of the proteins depending on S7 during assembly were found in this group but rather in a second group with intermediate chasing stability [S7 assembly domain; consisting of S7, S9, (S8), S19, and S3]. A number of proteins could be fully chased during the early assembly and therefore represent "late assembly proteins" (S10, S5, S13, S2, S21, S1). These findings fit well with the 30S assembly map.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Comparison of transcripts in Phalaenopsis bellina and Phalaenopsis equestris (Orchidaceae) flowers to deduce monoterpene biosynthesis pathway

    PubMed Central

    Hsiao, Yu-Yun; Tsai, Wen-Chieh; Kuoh, Chang-Sheng; Huang, Tian-Hsiang; Wang, Hei-Chia; Wu, Tian-Shung; Leu, Yann-Lii; Chen, Wen-Huei; Chen, Hong-Hwa

    2006-01-01

    Background Floral scent is one of the important strategies for ensuring fertilization and for determining seed or fruit set. Research on plant scents has hampered mainly by the invisibility of this character, its dynamic nature, and complex mixtures of components that are present in very small quantities. Most progress in scent research, as in other areas of plant biology, has come from the use of molecular and biochemical techniques. Although volatile components have been identified in several orchid species, the biosynthetic pathways of orchid flower fragrance are far from understood. We investigated how flower fragrance was generated in certain Phalaenopsis orchids by determining the chemical components of the floral scent, identifying floral expressed-sequence-tags (ESTs), and deducing the pathways of floral scent biosynthesis in Phalaneopsis bellina by bioinformatics analysis. Results The main chemical components in the P. bellina flower were shown by gas chromatography-mass spectrometry to be monoterpenoids, benzenoids and phenylpropanoids. The set of floral scent producing enzymes in the biosynthetic pathway from glyceraldehyde-3-phosphate (G3P) to geraniol and linalool were recognized through data mining of the P. bellina floral EST database (dbEST). Transcripts preferentially expressed in P. bellina were distinguished by comparing the scent floral dbEST to that of a scentless species, P. equestris, and included those encoding lipoxygenase, epimerase, diacylglycerol kinase and geranyl diphosphate synthase. In addition, EST filtering results showed that transcripts encoding signal transduction and Myb transcription factors and methyltransferase, in addition to those for scent biosynthesis, were detected by in silico hybridization of the P. bellina unigene database against those of the scentless species, rice and Arabidopsis. Altogether, we pinpointed 66% of the biosynthetic steps from G3P to geraniol, linalool and their derivatives. Conclusion This systems

  8. Active deformation processes of the Northern Caucasus deduced from the GPS observations

    NASA Astrophysics Data System (ADS)

    Milyukov, Vadim; Mironov, Alexey; Rogozhin, Eugeny; Steblov, Grigory; Gabsatarov, Yury

    2015-04-01

    The Northern Caucasus, as a part of the Alpine-Himalayan mobile belt, is a zone of complex tectonics associated with the interaction of the two major tectonic plates, Arabian and Eurasian. The first GPS study of the contemporary geodynamics of the Caucasus mountain system were launched in the early 1990s in the framework of the Russia-US joint project. Since 2005 observations of the modern tectonic motion of the Northern Caucasus are carried out using the continuous GPS network. This network encompasses the territory of three Northern Caucasian Republics of the Russian Federation: Karachay-Cherkessia, Kabardino-Balkaria, and North Ossetia. In the Ossetian part of the Northern Caucasus the network of GPS survey-mode sites has been deployed as well. The GPS velocities confirm weak general compression of the Northern Caucasus with at the rate of about 1-2 mm/year. This horizontal motion at the boundary of the Northern Caucasus with respect to the Eurasian plate causes the higher seismic and tectonic activity of this transition zone. This result confirms that the source of deformation of the Northern Caucasus is the sub-meridional drift of the Arabian plate towards the adjacent boundary of the Eastern European part of the Eurasian lithospheric plate. The concept of such convergence implies that the Caucasian segment of the Alpine-Himalayan mobile belt is under compression, the layers of sedimentary and volcanic rocks are folded, the basement blocks are subject to shifts in various directions, and the upper crust layers are ruptured by reverse faults and thrusts. Weak deviation of observed velocities from the pattern corresponding to homogeneous compression can also be revealed, and numerical modeling of deformations of major regional tectonic structures, such as the Main Caucasus Ridge, can explain this. The deformation tensor deduced from the velocity field also exhibits the sub-meridional direction of the major compressional axes which coincides with the direction of

  9. A history of chemically and radiatively important gases in air deduced from ALE/GAGE/AGAGE

    NASA Astrophysics Data System (ADS)

    Prinn, R. G.; Weiss, R. F.; Fraser, P. J.; Simmonds, P. G.; Cunnold, D. M.; Alyea, F. N.; O'Doherty, S.; Salameh, P.; Miller, B. R.; Huang, J.; Wang, R. H. J.; Hartley, D. E.; Harth, C.; Steele, L. P.; Sturrock, G.; Midgley, P. M.; McCulloch, A.

    2000-07-01

    We describe in detail the instrumentation and calibrations used in the Atmospheric Lifetime Experiment (ALE), the Global Atmospheric Gases Experiment (GAGE), and the Advanced Global Atmospheric Gases Experiment (AGAGE) and present a history of the majority of the anthropogenic ozone-depleting and climate-forcing gases in air based on these experiments. Beginning in 1978, these three successive automated high-frequency in situ experiments have documented the long-term behavior of the measured concentrations of these gases over the past 20 years, and show both the evolution of latitudinal gradients and the high-frequency variability due to sources and circulation. We provide estimates of the long-term trends in total chlorine contained in long-lived halocarbons involved in ozone depletion. We summarize interpretations of these measurements using inverse methods to determine trace gas lifetimes and emissions. Finally, we provide a combined observational and modeled reconstruction of the evolution of chlorocarbons by latitude in the atmosphere over the past 60 years which can be used as boundary conditions for interpreting trapped air in glaciers and oceanic measurements of chlorocarbon tracers of the deep oceanic circulation. Some specific conclusions are as follows: (1) International compliance with the Montreal Protocol is so far resulting in chlorofluorocarbon and chlorocarbon mole fractions comparable to target levels; (2) mole fractions of total chlorine contained in long-lived halocarbons (CCl2F2, CCl3F, CH3CCl3, CCl4, CHClF2, CCl2FCClF2, CH3Cl, CH2Cl2, CHCl3, CCl2=CCl2) in the lower troposphere reached maximum values of about 3.6 ppb in 1993 and are beginning to slowly decrease in the global lower atmosphere; (3) the chlorofluorocarbons have atmospheric lifetimes consistent with destruction in the stratosphere being their principal removal mechanism; (4) multiannual variations in chlorofluorocarbon and chlorocarbon emissions deduced from ALE/GAGE/AGAGE data are

  10. Assembly of the central domain of the 30S ribosomal subunit: roles for the primary binding ribosomal proteins S15 and S8.

    PubMed

    Jagannathan, Indu; Culver, Gloria M

    2003-07-01

    Assembly of the 30S ribosomal subunit occurs in a highly ordered and sequential manner. The ordered addition of ribosomal proteins to the growing ribonucleoprotein particle is initiated by the association of primary binding proteins. These proteins bind specifically and independently to 16S ribosomal RNA (rRNA). Two primary binding proteins, S8 and S15, interact exclusively with the central domain of 16S rRNA. Binding of S15 to the central domain results in a conformational change in the RNA and is followed by the ordered assembly of the S6/S18 dimer, S11 and finally S21 to form the platform of the 30S subunit. In contrast, S8 is not part of this major platform assembly branch. Of the remaining central domain binding proteins, only S21 association is slightly dependent on S8. Thus, although S8 is a primary binding protein that extensively contacts the central domain, its role in assembly of this domain remains unclear. Here, we used directed hydroxyl radical probing from four unique positions on S15 to assess organization of the central domain of 16S rRNA as a consequence of S8 association. Hydroxyl radical probing of Fe(II)-S15/16S rRNA and Fe(II)-S15/S8/16S rRNA ribonucleoprotein particles reveal changes in the 16S rRNA environment of S15 upon addition of S8. These changes occur predominantly in helices 24 and 26 near previously identified S8 binding sites. These S8-dependent conformational changes are consistent with 16S rRNA folding in complete 30S subunits. Thus, while S8 binding is not absolutely required for assembly of the platform, it appears to affect significantly the 16S rRNA environment of S15 by influencing central domain organization.

  11. CMB and the elementary particles structure deduced from QFT of non-dot model

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Guang

    In my paper ‘Planck Constant Deduced from Metrical Results of Doppler Effect of Moving Particle —Uncertainty Principle Caused by Collision of a Particle with CMB Photons and Virtual Photons (H05-0036-10)’ the absolute velocity is decided by CMB which as a mark of the vacuum. CMB come from the thermal radiation of stars via gravitational redshift about 10 (13) year (E14- 0032-08). In my paper ‘Quanta turn-advance ism, China Science && Technology Overview 131 192-210 (2011)’, QFT four-dimensional uncertainty principle and momentum-energy conservation law had been generalized as a five-dimensional equations: de Broglie wavelength as a position vector \\underline{q}= (i c t, r, s), momentum \\underline{P} = (i E / c, P, U c), \\underline{q} = i h / \\underline{P}, \\underline{q} \\underline{q} = 0, \\underline{P} \\underline{P} = 0, Sigma∑ \\underline{P} = \\underline{P} (0) . The five-dimensional time-space-spin had been quantized as a non-dot model basic cell, the lowest energy state vertical polarized left spin 1/2 neutrino and right spin 1/2 antineutrino are just the left, right advance unit quanta _{0}nuυ, nuυ _{0} and left, right back unit quanta (0) nuυ, nuυ (0) , it again compose into spin 1 unit advance photons _{0}nuυnuυ _{0} and back (0) nuυnuυ (0) , spin 0 unit rest mass nuυ _{0}nuυ (0) and anti-mass _{0}nuυ (0) nuυ, spin 0 unit positive charge _{0}nuυnuυ (0) and negative charge nuυ _{0} (0) nuυ. It accord to the high energy physics experimental results of the transformation among the photons, masses quanta and charges quanta. The physical vacuum is the even collocation of non-combinational nuυ _{0} or _{0}nuυ. QFT is no longer with divergence difficulty by the non-dot model. It is mathematically easy that from five-dimensional equations deduce out the Dirac, Klein-Gordan, Maxwell equations and Lorentz force formula, but appear some new results. The interactions between _{0}nuυ, nuυ _{0}, (0) nuυ, nuυ (0) , i.e., force f

  12. Structural change of E. coli separated and complexed 30S and 50S ribosomal subunits due to Mg 2+ ions: SANS experiments

    NASA Astrophysics Data System (ADS)

    Briganti, G.; Pedone, F.; Giansanti, A.; Giordano, R.

    1995-02-01

    Small-angle neutron-scattering experiments have been performed on E. Coli 70S ribosomes and on 50S and 30S separated subunits in the presence and absence of magnesium ions. In the 70S complex in presence of magnesium, the scattering intensity at Q = 0 ( I(0)) is roughly two times higher than without magnesium, in apparent agreement with the general view of an association-dissociation of the subunits induced by magnesium. But a similar increment is observed in both separated subunits too. The probability distribution functions of the intra-particle distance p( r), obtained by Fourier transforming, the experimental data, indicate that, even at low temperature (5°C) and concentration (0.1 wt%), the 70S and the separated subunits form aggregates. In all samples, the absence of Mg 2+ ions shifts and shrinks p( r) in the single-particle region, below 200 Å, and affects the shape of the curve in the aggregate region. Our results suggest that the presence of Mg 2+ ions does not strongly affect the degree of complexation of the subunits: the 70S complex retains its individuality even in the absence of magnesium, but undergoes structural rearrangements similar to those in 30S and 50S.

  13. On the moment of inertia in deformed Ba-Xe nuclei as deduced from gamma-gamma energy correlation experiments

    NASA Astrophysics Data System (ADS)

    Lindblad, Th.; Hildingsson, L.; Jerrestam, D.; Källberg, A.; Johnson, A.; Herrlander, C. J.; Klamra, W.; Kerek, A.; Lindén, C. G.; Kownacki, J.; kowski, J. Bial; Vertse, T.

    1982-04-01

    The γ-rays following reactions induced by bombarding targets of 114, 116, 118, 120, 122Sn with 118 MeV 12C ions were investigated using six NaI(Tl) detectors in a two-dimensional coincidence arrangement. Experimental energy-correlation spectra were extracted from the original coincidence matrices. The energy-correlation spectra exhibit the features expected for rotational nuclei and were used to deduce information on the moment of inertia I(2) = ΔI/Δω . The gross properties of the behaviour of I(2) in the Ba-Xe region are discussed together with their interpretation within the cranked shell model (CSM).

  14. Structural change induced by removal of magnesium ions on E. coli 70S ribosomes and 30S and 50S separated subunits

    NASA Astrophysics Data System (ADS)

    Briganti, G.; Giansanti, A.; Bonincontro, A.; Mengoni, M.; Giordano, R.

    1996-09-01

    To clarify the intra- and inter-particle effects of magnesium ions on E. coli ribosomes we have performed measurements of light scattering intensity, index of refraction and small-angle neutron scattering on the 70S complex and 30S and 50S subunits with and without magnesium. The results indicate that magnesium has a specific intra-particle effect on the subunits as well as on the 70S complex. Besides, the distance distribution function shows that magnesium has an effect on the supra-ribosomal aggregation. The combination of these intra- and inter-particle effects completely hides, in the scattering experiments, any effect of magnesium on the degree of association of the two subunits into the 70S complex.

  15. A Woman in Her 30s With a Past History of HIV Disease Presented With Recurrent Fever, Night Sweats, and Small Bilateral Pulmonary Nodules.

    PubMed

    Hashmi, Hafiz Rizwan Talib; Niazi, Masooma; Adrish, Muhammad

    2016-06-01

    A woman in her 30s presented with recurrent low-grade fever and cough (onset, 1 week). She reported occasional night sweats and weight loss of approximately 20 pounds over the past 4 months. She denied nausea, vomiting, diarrhea, or any urinary complaints. Her past medical history was significant for chronic hepatitis C and HIV infection, the latter diagnosed in 2001. She was noncompliant with highly active antiretroviral therapy for more than 4 years and had pneumocystis pneumonia 2 years prior to this presentation. She had a 10-pack per year smoking history and reported active use of cocaine and heroin. The patient denied any occupational exposures. PMID:27287594

  16. New RNA-protein crosslinks in domains 1 and 2 of E. coli 30S ribosomal subunits obtained by means of an intrinsic photoaffinity probe.

    PubMed Central

    Hajnsdorf, E; Favre, A; Expert-Bezançon, A

    1989-01-01

    Functionally active 70S ribosomes containing 4-thiouridine (s4U) in place of uridine were prepared by a formerly described in vivo substitution method. Proteins were crosslinked to RNA by 366 nm photoactivation of s4U. We observe the systematic and characteristic formation of 30S dimers; they were eliminated for analysis of RNA-protein crosslinks. M13 probes containing rDNA inserts complementary to domains 1 and 2 of 16S RNA from the 5'end up to nucleotide 868 were used to select contiguous or overlapping RNA sections. The proteins covalently crosslinked to each RNA section were identified as S3, S4, S5, S7, S9, S18, S20 and S21. Several crosslinks are compatible with previously published sites for proteins S5, S18, S20 and S21; others for proteins S3, S4, S7, S9, S18 correspond necessarily to new sites. Images PMID:2646595

  17. Mutations of ribosomal protein S5 suppress a defect in late-30S ribosomal subunit biogenesis caused by lack of the RbfA biogenesis factor

    PubMed Central

    Nord, Stefan; Bhatt, Monika J.; Tükenmez, Hasan; Farabaugh, Philip J.; Wikström, P. Mikael

    2015-01-01

    The in vivo assembly of ribosomal subunits requires assistance by maturation proteins that are not part of mature ribosomes. One such protein, RbfA, associates with the 30S ribosomal subunits. Loss of RbfA causes cold sensitivity and defects of the 30S subunit biogenesis and its overexpression partially suppresses the dominant cold sensitivity caused by a C23U mutation in the central pseudoknot of 16S rRNA, a structure essential for ribosome function. We have isolated suppressor mutations that restore partially the growth of an RbfA-lacking strain. Most of the strongest suppressor mutations alter one out of three distinct positions in the carboxy-terminal domain of ribosomal protein S5 (S5) in direct contact with helix 1 and helix 2 of the central pseudoknot. Their effect is to increase the translational capacity of the RbfA-lacking strain as evidenced by an increase in polysomes in the suppressed strains. Overexpression of RimP, a protein factor that along with RbfA regulates formation of the ribosome's central pseudoknot, was lethal to the RbfA-lacking strain but not to a wild-type strain and this lethality was suppressed by the alterations in S5. The S5 mutants alter translational fidelity but these changes do not explain consistently their effect on the RbfA-lacking strain. Our genetic results support a role for the region of S5 modified in the suppressors in the formation of the central pseudoknot in 16S rRNA. PMID:26089326

  18. Pattern of 4-thiouridine-induced cross-linking in 16S ribosomal RNA in the Escherichia coli 30S subunit.

    PubMed

    Nanda, Kavita; Wollenzien, Paul

    2004-07-20

    The locations of RNA-RNA cross-links in 16S rRNA were determined after in vivo incorporation of 4-thiouridine (s(4)U) into RNA in a strain of Escherichia coli deficient in pyrimidine synthesis and irradiation at >320 nm. This was done as an effort to find RNA cross-links different from UVB-induced cross-links that would be valuable for monitoring the 30S subunit in functional complexes. Cross-linked 16S rRNA was separated on the basis of loop size, and cross-linking sites were identified by reverse transcription, RNase H cleavage, and RNA sequencing. A limited number of RNA-RNA cross-links in nine regions were observed. In five regions-s(4)U562 x C879-U884, s(4)U793 x A1519, s(4)U1189 x U1060-G1064, s(4)U1183 x A1092, and s(4)U991 x C1210-U1212-the s(4)U-induced cross-links are similar to UVB-induced cross-links observed previously. In four other regions-s(4)U960 x A1225, s(4)U820 x G570, s(4)U367 x A55-U56, and s(4)U239 x A120-the s(4)U-induced cross-links are different from UVB-induced cross-links. The pattern of cross-linking is not limited by the distribution of s(4)U, because there are at least 112 s(4)U substitution sites in the 16S rRNA. The relatively small number of s(4)U-mediated cross-links is probably determined by the organization of the RNA in the 30S subunit, which allows RNA conformational flexibility needed for cross-link formation in just a limited region.

  19. The interstellar redding law in the ultraviolet deduced from filter photometry obtained by the OAO-2 satellite

    NASA Technical Reports Server (NTRS)

    Laget, M.

    1972-01-01

    Filter photometry has been obtained of 16 BO stars at ten effective wavelengths in the range 4250-1430 A. The wavelength dependence of the interstellar reddening law, deduced from a least squares fit of the observed values to the reddening line at each band, is found in satisfactory agreement with that derived by Bless and Savage (1972). Toward the shorter wavelengths the increase of the computed probable error of the slope of the mean reddening line suggests that large fluctuations in the law may occur from star to star. Similar computations, separating main-sequence stars and supergiants, indicate that the large fluctuations of the law appear to be well related to the luminosity of the stars; the supergiants show systematically less extinction, this deficiency becoming large toward the far UV. The small number in the sample however, does not allow a general conclusion to be drawn.

  20. Measurements of the magnetic field orientation in the Jovian ionosphere deduced from Pioneer 10 and 11 scintillation observations

    NASA Technical Reports Server (NTRS)

    Woo, R.; Yang, F.-C.

    1978-01-01

    In this paper the S band scintillations observed during the Pioneer 10 and 11 occultation measurements of Jupiter are analyzed. It is found that while the electron density irregularities are isotropic in the collision-dominated lower ionosphere, they are anisotropic in the upper ionosphere because of alignment along the magnetic field. By using Rytov's approximation the frequency spectrum of the log-amplitude scintillations is derived for a wave propagating in an anisotropic turbulent medium. It is shown that the spectrum depends to a large extent on the direction of anisotropy and is therefore useful for measuring the orientation of the magnetic field in regions that have not yet been probed by direct measurements. This new technique is applied to the Pioneer 10 and 11 observations, and is used to deduce the first measurements of magnetic field orientation in the ionosphere of Jupiter.

  1. Submarine paleoseismology of the northern Hikurangi subduction margin of New Zealand as deduced from Turbidite record since 16 ka

    NASA Astrophysics Data System (ADS)

    Pouderoux, Hugo; Proust, Jean-Noël; Lamarche, Geoffroy

    2014-01-01

    Paleoseismic studies seek to characterise the signature of pre-historical earthquakes by deriving quantitative information from the geological record such as the source, magnitude and recurrence of moderate to large earthquakes. In this study, we provide a ˜16,000 yr-long paleo-earthquake record of the 200 km-long northern Hikurangi Margin, New Zealand, using cm-thick deep-sea turbidites identified in sediment cores. Cores were collected in strategic locations across the margin within three distinct morphological re-entrants - the Poverty, Ruatoria and Matakaoa re-entrants. The turbidite facies vary from muddy to sandy with evidence for rare hyperpycnites interbedded with hemipelagites and tephra. We use the Oxal probabilistic software to model the age of each turbidite, using the sedimentation rate of hemipelagite deduced from well-dated tephra layers and radiocarbon ages measurements on planktonic foraminifera.

  2. Field line equipotentiality and ion neutral collision frequencies in the dynamo region deduced from Saint-Santin ion drift measurements

    SciTech Connect

    Taieb, C.; Blanc, M.

    1981-08-01

    We analyze three-dimensional ion drift data from the Saint-Santin incoherent scatter facility to test experimentally the theoretical description of ion transport in the ionospheric dynamo layer, and to deduce electric fields and ion neutral collision frequencies from the observed drifts. Using a geometrical representation of the ion momentum equation, we show that at middle latitudes, because horizontal neutral wind influences ion motions both parallel and orthogonal to the field lines in the ionospheric dynamo layer, the information contained in a three-dimensional ion drift measurement is redundant, thus permitting to check the standard theoretical description of ionospheric electrodynamics in two ways. First, assuming a model ion-neutral collision frequency profile, one can deduce the north-south perpendicular component of the electric field function of height in the E region from Saint-Santin drift data. We find that its altitude variations remain within the experimental uncertainty of the method, in agreement with the theoretical assumption of equipotential field lines. Second, assuming that the electric field is constant in altitude, one can determine the ion collision ratio, or ratio of the ion collision frequency to the ion gyrofrequency, from a comparison of E and F region drift measurements. Daily median values of the ion collision frequencies, thus obtained for each of the three seasons, are found to compare reasonably well with ion collision frequencies derived from the Jacchia neutral atmosphere model for the case of the equinox sample, but determinations for the other seasons are contaminated by a high level of measurement noise.

  3. Changes in force production and stroke parameters of trained able-bodied and unilateral arm-amputee female swimmers during a 30 s tethered front-crawl swim.

    PubMed

    Lee, Casey Jane; Sanders, Ross H; Payton, Carl J

    2014-01-01

    This study examined changes in the propulsive force and stroke parameters of arm-amputee and able-bodied swimmers during tethered swimming. Eighteen well-trained female swimmers (nine unilateral arm amputees and nine able-bodied) were videotaped performing maximal-effort 30 s front-crawl swims, while attached to a load cell mounted on a pool wall. Tether force, stroke rate, stroke phase durations and inter-arm angle were quantified. The able-bodied group produced significantly higher mean and maximum tether forces than the amputee group. The mean of the intra-cyclic force peaks was very similar for both groups. Mean and maximum tether force had significant negative associations with 100 m swim time, for both groups. Both groups exhibited a similar fatigue index (relative decrease in tether force) during the test, but the amputees had a significantly greater stroke rate decline. A significant positive association between stroke rate decline and fatigue index was obtained for the able-bodied group only. Inter-arm angle and relative phase durations did not change significantly during the test for either group, except the recovery phase duration of the arm amputees, which decreased significantly. This study's results can contribute to the development of a more evidence-based classification system for swimmers with a disability.

  4. Lithium- and boron-bearing brines in the Central Andes: exploring hydrofacies on the eastern Puna plateau between 23° and 23°30'S

    NASA Astrophysics Data System (ADS)

    Steinmetz, R. L. López

    2016-04-01

    Internally drained basins of the Andean Plateau are lithium- and boron-bearing systems. The exploration of ionic facies and parental links in a playa lake located in the eastern Puna (23°-23°30'S) was assessed by hydrochemical determinations of residual brines, feed waters and solutions from weathered rocks. Residual brines have been characterized by the Cl- (SO4 =)/Na+ (K+) ratio. Residual brines from the playa lake contain up to 450 mg/l of boron and up to 125 mg/l of lithium, and the Las Burras River supplies the most concentrated boron (20 mg/l) and lithium (3.75 mg/l) inflows of the basin. The hydro-geochemical assessment allowed for the identification of three simultaneous sources of boron: (1) inflow originating from granitic areas of the Aguilar and Tusaquillas ranges; (2) weathering of the Ordovician basement; and (3) boron-rich water from the Las Burras River. Most of the lithium input of the basin is likely generated by present geothermal sources rather than by weathering and leaching of ignimbrites and plutonic rocks. However, XRD analyses of playa lake sediments revealed the presence of lithian micas of clastic origin, including taeniolite and eucriptite. This study is the first to document these rare Li-micas from the Puna basin. Thus, both residual brines and lithian micas contribute to the total Li content in the studied hydrologic system.

  5. Deducing the temporal order of cofactor function in ligand-regulated gene transcription: theory and experimental verification.

    PubMed

    Dougherty, Edward J; Guo, Chunhua; Simons, S Stoney; Chow, Carson C

    2012-01-01

    Cofactors are intimately involved in steroid-regulated gene expression. Two critical questions are (1) the steps at which cofactors exert their biological activities and (2) the nature of that activity. Here we show that a new mathematical theory of steroid hormone action can be used to deduce the kinetic properties and reaction sequence position for the functioning of any two cofactors relative to a concentration limiting step (CLS) and to each other. The predictions of the theory, which can be applied using graphical methods similar to those of enzyme kinetics, are validated by obtaining internally consistent data for pair-wise analyses of three cofactors (TIF2, sSMRT, and NCoR) in U2OS cells. The analysis of TIF2 and sSMRT actions on GR-induction of an endogenous gene gave results identical to those with an exogenous reporter. Thus new tools to determine previously unobtainable information about the nature and position of cofactor action in any process displaying first-order Hill plot kinetics are now available.

  6. Anti-platelet autoantibodies from ITP patients recognize an epitope in GPIIb/IIIa deduced by complementary hydropathy.

    PubMed Central

    De Souza, S J; Sabbaga, J; D'Amico, E; Pasqualini, R; Brentani, R

    1992-01-01

    Idiopathic thrombocytopenic purpura (ITP) is a frequent platelet disorder due to the presence of anti-platelet autoantibodies. Recently a fibronectin/fibrinogen receptor in platelets, integrin GPIIb/IIIa, has been implicated as the antigen in chronic ITP. To examine the epitopes involved in the autoimmune response against GPIIb/IIIa we have used concepts from the complementary hydropathy principle. We used the peptide Trp-Thr-Val-Pro-Thr-Ala, WTVPTA (deduced from the complementary nucleotide sequence to that which codes for the Arg-Gly-Asp, RGD, domain in fibronectin), to test the immunologic activity of ITP sera. Sera from 31 patients with clinically defined ITP were tested in ELISA for reactivity towards WTVPTA and affinity purified GPIIb/IIIa. Seventeen sera (57%) reacted strongly with the glycoprotein complex, five of which reacted with the peptide. By affinity chromatography of one of these sera, we were able to show that antibodies that bind to the peptide are within the population that binds to GPIIb/IIIa. Liquid phase competition experiments revealed that binding of ITP serum to WTVPTA was inhibited only by a hydropathically compatible peptide. Our data indicate that autoantibodies can bind to hydropathically generated antigenic determinants and thus, render these peptides clinically important as diagnostic tools. Images Figure 4 Figure 5 PMID:1371492

  7. Evolutionary relationships of a plant-pathogenic mycoplasmalike organism and Acholeplasma laidlawii deduced from two ribosomal protein gene sequences.

    PubMed Central

    Lim, P O; Sears, B B

    1992-01-01

    The families within the class Mollicutes are distinguished by their morphologies, nutritional requirements, and abilities to metabolize certain compounds. Biosystematic classification of the plant-pathogenic mycoplasmalike organisms (MLOs) has been difficult because these organisms have not been cultured in vitro, and hence their nutritional requirements have not been determined nor have physiological characterizations been possible. To investigate the evolutionary relationship of the MLOs to other members of the class Mollicutes, a segment of a ribosomal protein operon was cloned and sequenced from an aster yellows-type MLO which is pathogenic for members of the genus Oenothera and from Acholeplasma laidlawii. The deduced amino acid sequence data from the rpl22 and rps3 genes indicate that the MLOs are more closely related to A. laidlawii than to animal mycoplasmas, confirming previous results from 16S rRNA sequence comparisons. This conclusion is also supported by the finding that the UGA codon is not read as a tryptophan codon in the MLO and A. laidlawii, in contrast to its usage in Mycoplasma capricolum. PMID:1556079

  8. Deducing the 236Pu(n,f) and 237Pu(n,f) cross sections via the surrogate ratio method

    NASA Astrophysics Data System (ADS)

    Hughes, R. O.; Beausang, C. W.; Ross, T. J.; Burke, J. T.; Casperson, R. J.; McCleskey, M.; Cooper, N.; Escher, J. E.; Gell, K. B.; Good, E.; Humby, P.; Saastimoinen, A.; Tarlow, T. D.

    2013-10-01

    The short half-lives associated with certain minor actinide nuclei that are relevant to stockpile stewardship pursuits and the development of next-generation nuclear reactors make direct neutron measurements very challenging. In certain cases, a stable beam and target ``surrogate reaction'' can be used in lieu of the neutron-induced reaction, and the (n,f) cross section can then be deduced indirectly. Agreement between surrogate and direct measurements for (n,f) cross sections in actinide nuclei is usually within 10%. The present work reports on the measurement of the 236Pu(n,f) and 237Pu(n,f) cross sections via 239Pu(p,tf) and 239Pu(p,df) surrogate reactions, respectively. The experiment was performed at the Texas A&M University Cyclotron Facility using a 28.5 MeV proton beam to bombard 239Pu and 235U targets. Outgoing light ions were detected in coincidence with fission fragments using the STAR-LiTe detector array. Results of the analysis will be presented. This work was supported by DoE Grant Numbers: DE-FG52-09NA29454 and DE-FG02-05ER41379 (Richmond), DE-AC52-07NA27344 (LLNL) and DE-FG52-09NA29467 (TAMU).

  9. New prospects for deducing the evolutionary history of metabolic pathways in prokaryotes: Aromatic biosynthesis as a case-in-point

    NASA Astrophysics Data System (ADS)

    Ahmad, Suhail; Jensen, Roy A.

    1988-03-01

    Metabolic pathways of prokaryotes are more biochemically diverse than is generally recognized. Distinctive biochemical features are shared by phylogenetic clusters. The hierarchical levels of characterstate clustering depends upon evolutionary events which fortuitously became fixed in the genome of a common ancestor. Prokaryotes can now be ordered on a phylogenetic tree. This allows the evolutionary steps that underlie the construction and regulation of appropriately complex biochemical pathways to be traced in an evolutionary progression of prokaryote types that house these pathways. Essentially the approach is to deduce ancestral character states at ever deeper phylogenetic levels, utilizing logical principles of maximum parsimony. The current perspective on the evolution of the biochemical pathway for biosynthesis of aromatic amino acids is developed as a case-in-point model for analyses that should be feasible with many major metabolic systems. Phenylalanine biosynthesis probably arose prior to the addition of branches leading to tyrosine and tryptophan. An evolutionary scenario is developed that begins with non-enzymatic reactions which may have operated in primitive systems, followed by the evolution of an enzymatic system that pre-dated the divergence of major lineages of modern eubacteria (Gram-positive bacteria, Gram-negative purple bacteria, and cyanobacteria).

  10. Neutron spectrum and yield of the Hiroshima A-bomb deduced from radionuclide measurements at one location.

    PubMed

    Rühm, W; Kato, K; Korschinek, G; Morinaga, H; Nolte, E

    1995-07-01

    In this paper measurements of the radionuclides of 36Cl, 41Ca, 60Co, 152Eu and 154Eu in samples from Hiroshima, which were exposed to neutrons of the A-bomb explosion, are interpreted. In order to calculate the neutron spectrum at the sample site, neutron transport calculations using Monte Carlo techniques were carried out. Activation profiles in a granite mock-up irradiated with reactor neutrons could be reproduced by this method using DS86 input parameters. The calculated neutron spectrum at the sample site for non-thermal neutrons is identical to that obtained in DS86, but contains some 50% more thermal neutrons. The influence of parameters like soil composition, source terms and air humidity on the activation of these radioisotopes is discussed. The granite-covered earth at the sample site, for example, hardens the spectrum in comparison with DS86 values. Even when using a fission spectrum pointing downward and neglecting air humidity one cannot explain our 36Cl measurements. If the effective thermal neutron fluences, that have a similar ratio of resonance integral to thermal neutron capture cross sections obtained from 36Cl, 41Ca and 152Eu, are averaged, a bomb yield of about 16 kt is deduced in agreement with a bomb yield of (15 +/- 3) kt estimated in DS86.

  11. Metabolic potential of the organic-solvent tolerant Pseudomonas putida DOT-T1E deduced from its annotated genome

    PubMed Central

    Udaondo, Zulema; Molina, Lazaro; Daniels, Craig; Gómez, Manuel J; Molina-Henares, María A; Matilla, Miguel A; Roca, Amalia; Fernández, Matilde; Duque, Estrella; Segura, Ana; Ramos, Juan Luis

    2013-01-01

    Summary Pseudomonas putida DOT-T1E is an organic solvent tolerant strain capable of degrading aromatic hydrocarbons. Here we report the DOT-T1E genomic sequence (6 394 153 bp) and its metabolic atlas based on the classification of enzyme activities. The genome encodes for at least 1751 enzymatic reactions that account for the known pattern of C, N, P and S utilization by this strain. Based on the potential of this strain to thrive in the presence of organic solvents and the subclasses of enzymes encoded in the genome, its metabolic map can be drawn and a number of potential biotransformation reactions can be deduced. This information may prove useful for adapting desired reactions to create value-added products. This bioengineering potential may be realized via direct transformation of substrates, or may require genetic engineering to block an existing pathway, or to re-organize operons and genes, as well as possibly requiring the recruitment of enzymes from other sources to achieve the desired transformation. Funding Information Work in our laboratory was supported by Fondo Social Europeo and Fondos FEDER from the European Union, through several projects (BIO2010-17227, Consolider-Ingenio CSD2007-00005, Excelencia 2007 CVI-3010, Excelencia 2011 CVI-7391 and EXPLORA BIO2011-12776-E). PMID:23815283

  12. Photoinduced cross-linkage, in situ, of Escherichia coli 30S ribosomal proteins to 16S rRNA: identification of cross-linked proteins and relationships between reactivity and ribosome structure.

    PubMed

    Gorelic, L

    1976-08-10

    The kinetics of photoinduced cross-linkage of Escherichia coli 30S ribosomal proteins to the 16S-rRNA molecule in the intact Escherichia coli 30S ribosomal subunit was studied in this report. All of the 30S ribosomal proteins become cross-linked to the 16S rRNA before changes in the sedimentation characteristics of the 30S ribosomal subunit can be detected. The proteins exhibit different reactivities in the cross-linkage reaction. One group of proteins-S3, S7-S9, S11, S12, and S15-S19-is cross-linked to the 16S rRNA by single-hit kinetics, or by photoprocesses of nonunity but low multiplicities. A second group of proteins--S1, S2, S4-S6, S10, S13, S14, and S21--is cross-linked to the 16S rRNA by photoprocesses of a complex nature. A comparison of these data with other properties of the individual 30S ribosomal proteins related to ribosome structure indicated that most of the 30S ribosomal proteins cross-linked to the 16S rRNA by photoprocesses of low multiplicities had been classified rRNA-binding proteins by nonphotochemical methods, and most of the proteins cross-linked to the 16S rRNA by photoprocesses of large multiplicities had been classified as nonbinding proteins. There were certain exceptions to these correlations. Proteins S4 and S20, both RNA-binding proteins, become cross-linked to the 16S rRNA by photoprocessses of large multiplicities, and proteins S3, S11, S12, and S18, none of which have been classified RNA-binding proteins, exhibited low multiplicities in the cross-linkage reaction. All of these exceptions could be explained in terms of limitations inherent in the photochemical methods used in this study and in other types of methods that have been used to study RNA-protein interactions in the 30S ribosomal subunit. The data presented here also suggest that labile RNA-protein cross-links are present in the uv-irradiated 30S ribosomal subunits, and that neither peptide-bond cleavage nor photoinduced modification of the charged side-chain groups in

  13. Coseismic Slip Distribution of the 2011 off the Pacific Coast of Tohoku Earthquake Deduced from Land and Seafloor Geodesy

    NASA Astrophysics Data System (ADS)

    Iinuma, T.; Kido, M.; Osada, Y.; Inazu, D.; Ohzono, M.; Tsushima, H.; Hino, R.; Ohta, Y.; Suzuki, S.; Fujimoto, H.; Miura, S.; Shinohara, M.

    2011-12-01

    The 2011 off the Pacific coast of Tohoku Earthquake (M9.0) occurred on 11 March 2011 off the Pacific coast of Tohoku district, northeastern Japan, where the Pacific plate is subducting beneath the overriding continental plate. A number of models of the coseismic slip distribution of this earthquake have been already proposed based on seismological, geodetic, and tsunami data. Here, we present comprehensive coseismic slip distribution model based not only on land GPS data but also on seafloor geodetic observations, which are obtained through recent observation cruises. We combined displacements at seafloor sites that are deduced from two different types of seafloor observations with the displacements at land GPS stations. One is the seafloor crustal deformation observation with GPS/Acoustic ranging (GPS/A). Horizontal displacements associated with the 2011 Tohoku earthquake at 2 GPS/A stations are estimated by comparing the station positions deduced from the observations before and after the earthquake. Another type of the seafloor data is seafloor water pressure that is observed by means of ocean bottom pressure gauge (OBP). We analyzed OBP data observed at 2 cabled and 4 self pop-up stations, and estimated vertical displacements due to the main shock. Displacements at 5 GPS/A stations of Japan Coast Guard [Sato et al., 2011, science] are also included to estimate the coseismic slip distribution of the earthquake. Estimated slip distribution of the 2011 Tohoku Earthquake shows following features. 1) The area of large slip ( > 20 m) is about 100 km x 200 km on the plate interface shallower than 30 km in depth. 2) There is no large slip occurred off southern Iwate prefecture on the plate interface throughout shallow to deep. 3) The latitudinal range of the area of large slip almost corresponds to the one of the area of strong interplate coupling zone off Miyagi prefecture. 4) Significant slip is estimated around the rupture area of 1978 M7.4 Miyagi-oki earthquake (40

  14. Utilization of metabonomics to identify serum biomarkers in murine H22 hepatocarcinoma and deduce antitumor mechanism of Rhizoma Paridis saponins.

    PubMed

    Qiu, Peiyu; Man, Shuli; Yang, He; Fan, Wei; Yu, Peng; Gao, Wenyuan

    2016-08-25

    Murine H22 hepatocarcinoma model is so popular to be used for the preclinical anticancer candidate's evaluation. However, the metabolic biomarkers of this model were not identified. Meanwhile, Rhizoma Paridis saponins (RPS) as natural products have been found to show strong antitumor activity, while its anti-cancer mechanism is not clear. To search for potential metabolite biomarkers of this model, serum metabonomics approach was applied to detect the variation of metabolite biomarkers and the related metabolism genes and signaling pathway were used to deduce the antitumor mechanisms of RPS. As a result, ten serum metabolites were identified in twenty-four mice including healthy mice, non-treated cancer mice, RPS-treated cancer mice and RPS-treated healthy mice. RPS significantly decreased tumor weight correlates to down-regulating lactate, acetate, N-acetyl amino acid and glutamine signals (p < 0.05), which were marked metabolites screened according to the very important person (VIP), loading plot and receiver operating characteristic curve (ROC) tests. For the analysis of metabolic enzyme related genes, RPS reversed the aerobic glycolysis through activating tumor suppressor p53 and PTEN, and suppressed FASN to inhibit lipogenesis. What's more, RPS repressed Myc and GLS expression and decreased glutamine level. The regulating PI3K/Akt/mTOR and HIF-1α/Myc/Ras networks also participated in these metabolic changes. Taken together, RPS suppressed ATP product made the tumor growth slow, which indicated a good anti-cancer effect and new angle for understanding the mechanism of RPS. In conclusion, this study demonstrated that the utility of (1)H NMR metabolic profiles taken together with tumor weight and viscera index was a promising screening tool for evaluating the antitumor effect of candidates. In addition, RPS was a potent anticancer agent through inhibiting cancer cellular metabolism to suppress proliferation in hepatoma H22 tumor murine, which promoted the

  15. Light regulation of cGMP metabolism in toad rod outer segments (ROS) deduced from intact photoreceptor and cellfree kinetics

    SciTech Connect

    Dawis, S.M.; Graeff, R.M.; Heyman, R.A.; Walseth, T.F.; Butz, E.A.

    1987-05-01

    The rate of cGMP hydrolysis by phosphodiesterase (PDE) in intact ROS, monitored in dark-adapted isolated toad retina by the rate of /sup 18/O appearance in guanine nucleotide ..cap alpha..-phosphoryls, is 1/360th of that observed in disrupted ROS at a substrate concentration equivalent to the total (cGMP) in ROS. Low to moderate photic stimuli increase this cGMP hydrolytic rate up to 10-fold in intact ROS with little or no change in total (cGMP). G-protein activation determined in intact ROS by the fraction of GDP labeled with /sup 18/O corresponds with light-related increases in cGMP flux. In contrast, relatively high intensities and extended illumination cause attenuation of maximal cGMP hydrolysis with proportionate reductions in total (cGMP). From these observations combined with the effects of activated G-protein on kinetics and cGMP binding of ROS PDE the following model for light-regulation of cGMP metabolism was deduced: cGMP flux in intact ROS is severely restricted in the dark state because approximately 99% of the cGMP is bound to high affinity sites on the non-stimulated form of PDE. This constraint is relieved when activated G-protein converts the cGMP-binding form of PDE to a high K/sub m/ catalytic form. cGMP is then redistributed to a dynamic pool where it is available to PDE catalytic sites and lower affinity allosteric sites. The (cGMP) in the dynamic pool is maintained or further increased or decreased by modulating the activity of an apparently light-sensitive guanylyl cyclase.

  16. Evaluation des programmes de techniques d'education en services de garde (Evaluation of Programs of Educational Methods in Child Care Services. 2410-0521.

    ERIC Educational Resources Information Center

    Vigneau, Paul, Comp.

    In March 1994, Quebec's Commission on the Evaluation of Collegiate Teaching initiated an evaluation of "Techniques d'education en services de garde" (TESG) programs, or educational methods in child care services. This report presents results from the evaluation in three parts. The first section describes the following four stages of the…

  17. SIMMAX: A modern analog technique to deduce Atlantic sea surface temperatures from planktonic foraminifera in deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Pflaumann, Uwe; Duprat, Josette; Pujol, Claude; Labeyrie, Laurent D.

    1996-02-01

    leave the system.) (Paper 95PA01743,SIMMAX: A modern analog technique to deduce Atlantic sea surfacetemperatures from planktonic foraminifera in deep-sea sediments, UwePflaumann, Josette Duprat, Claude Pujol, and Laurent D. Labeyrie).Diskette may be ordered from American Geophysical Union, 2000Florida Avenue, N.W., Washington, DC 20009; Payment mustaccompany order.

  18. 600 yr High-Resolution Climate Reconstruction of the Atlantic Multidecadal Oscillation deduced from a Puerto Rican Speleothem

    NASA Astrophysics Data System (ADS)

    Vieten, Rolf; Winter, Amos; Scholz, Denis; Black, David; Spoetl, Christoph; Winterhalder, Sophie; Koltai, Gabriella; Schroeder-Ritzrau, Andrea; Terzer, Stefan; Zanchettin, Davide; Mangini, Augusto

    2016-04-01

    A multi-proxy speleothem study tracks the regional hydrological variability in Puerto Rico and highlights its close relation to the Atlantic Multidecadal Oscillation (AMO) describing low-frequency sea-surface temperature (SST) variability in the North Atlantic ocean. Our proxy record extends instrumental observations 600 years into the past, and reveals the range of natural hydrologic variability for the region. A detailed interpretation and understanding of the speleothem climate record is achieved by the combination of multi-proxy measurements, thin section petrography, XRD analysis and cave monitoring results. The speleothem was collected in Cueva Larga, a one mile-long cave system that has been monitored since 2012. MC-ICPMS 230Th/U-dating reveals that the speleothem grew constantly over the last 600 years. Trace element ratios (Sr/Ca and Mg/Ca) as well as stable isotope ratios (δ18O and δ13C) elucidate significant changes in atmospheric precipitation at the site. Monthly cave monitoring results demonstrate that the epikarst system responds to multi-annual changes in seepage water recharge. The drip water isotope and trace element composition lack short term or seasonal variability. This hydrological system creates favorable conditions to deduce decadal climate variability from Cueva Larga's climate record. The speleothem time series mimics the most recent AMO reconstruction over the last 200 years (Svendsen et al., 2014) with a time lag of 10-20 years. The lag seems to results from slow atmospheric signal transmission through the epikarst but the effect of dating uncertainties cannot be ruled out. Warm SSTs in the North Atlantic are related to drier conditions in Puerto Rico. During times of decreased rainfall a relative increase in prior calcite precipitation seems to be the main process causing increased Mg/Ca trace element ratios. High trace element ratios correlate to higher δ13C values. The increase in both proxies indicates a shift towards time

  19. 600 yr High-Resolution Climate Reconstruction of the Atlantic Multidecadal Variability deduced from a Puerto Rican Speleothem

    NASA Astrophysics Data System (ADS)

    Winter, A.; Vieten, R.

    2015-12-01

    A multi-proxy speleothem study tracks the regional hydrological variability in Puerto Rico and highlights its close relation to the Atlantic Multidecadal Oscillation. Our proxy record extends instrumental observations 600 years into the past, and reveals the range of natural hydrologic variability for the region. A detailed interpretation and understanding of the speleothem climate record is achieved by the combination of multi-proxy measurements, thin section petrography, XRD analysis and cave monitoring results. The speleothem was collected in Cueva Larga, a one mile-long cave system that has been monitored since 2012. MC-ICPMS 230Th/U-dating reveals that the speleothem grew constantly over the last 600 years. Trace element ratios (Sr/Ca and Mg/Ca) as well as stable isotope ratios (δ18O and δ13C) elucidate significant changes in atmospheric precipitation at the site. Monthly cave monitoring results demonstrate that the epikarst system responds to multi-annual changes in seepage water recharge. The drip water isotope and trace element composition lack short term or seasonal variability. This hydrological system creates favorable conditions to deduce decadal climate variability from Cueva Larga's climate record. The speleothem time series mimics the most-recently published AMO reconstruction over the last 200 years with a time lag of 10-20 years. The time lag seems to results from slow atmospheric signal transmission through the epikarst but the effect of dating uncertainties cannot be ruled out. Warm SSTs in the North Atlantic are related to drier conditions in Puerto Rico. During times of decreased rainfall a relative increase in prior calcite precipitation seems to be the main process causing increased Mg/Ca trace element ratios. High trace element ratios correlate to higher δ13C values. The increase in both proxies indicates a shift towards time periods of decreased rainfall. Over the past 600 years there are two intervals of increased Mg/Ca and δ13C values

  20. Deducing the magma chamber processes of middle Eocene volcanics, Sivas and Tokat regions; NE Turkey: Insights from clinopyroxene chemistry

    NASA Astrophysics Data System (ADS)

    Göçmengil, Gönenç; Karacık, Zekiye; Genç, Ş. Can; Prelevic, Dejan

    2016-04-01

    Middle Eocene Tokat and Sivas volcanic successions occur within the İzmir-Ankara-Erzincan suture zone. Different models are suggested for the development of the middle Eocene volcanism such as post-collisional, delamination and slab-breakoff models as well as the arc magmatism. In both areas, volcanic units cover all the basement units with a regional disconformity and comprise lavas spanning a compositional range from mainly basalt-basaltic andesite to a lesser amount trachyte. Here, we report mineral chemistry of different basaltic lavas through transect from northern continent (Tokat region, Pontides) to southern continent (Sivas region, Kırşehir block) to deduce the characteristics of the magma chamber processes which are active during the middle Eocene. Basaltic lavas include olivine bearing basalts (Ol-basalt: ± olivine + clinopyroxene + plagioclase); amphibole bearing basaltic andesite (Amp-basaltic andesite: amphibole + clinopyroxene + plagioclase ± biotite) and pyroxene bearing basaltic andesite (Px-basaltic andesite: clinopyroxene + plagioclase). Microlitic, glomeroporphyric and pilotaxitic texture are common. Clinopyroxene phenocrystals (macro ≥ 750 μm and micro ≤300 μm) are common in all three lava series which are investigated by transecting core to rim compositional profiles. They are generally augite and diopside; euhedral to subhedral in shape with oscillatory, normal and reverse zoning patterns. Also, all clinopyroxene phenocrystals are marked by moderately high Mg# (for Ol-basalt: 67-91; avg. 80; Amp-basaltic andesite: 76-83, avg: 80; Px -basaltic andesite 68-95, avg: 81). In Ol-basalt, clinopyroxene phenocrystals show normal zonation (high Mg# cores and low Mg# rims). In Amp-basaltic andesite, clinopyroxenes are generally homogenous in composition with minor variation of Mg# towards the rims. On the contrary, in Px-basaltic andesite, clinopyroxene macro phenocrystals show reverse zonation with the core with low Mg# and the rims with

  1. Global significance of a sub-Moho boundary layer (SMBL) deduced from high-resolution seismic observations

    USGS Publications Warehouse

    Fuchs, K.; Tittgemeyer, M.; Ryberg, T.; Wenzel, F.; Mooney, W.

    2002-01-01

    an on-going processes; nevertheless, the derived quantitative estimates of the SMBL properties provide important constraints for any hypothesis on scale-forming processes. Models to be tested by future numerical and field experiments are, for example, repeated subduction-convection stretching of oceanic lithosphere (marble-cake model) and schlieren formation at mid-ocean ridges. It is also proposed that the modeling of the observed blocking of Sn and Pn propagation at active plate margins offers a new tool to study the depth range of tectonics below the crust-mantle boundary. Finally, the deduced schlieren structure of the SMBL closes an important scale gap of three to four orders of magnitude between structural dimensions studied in petrological analysis of mantle samples (xenoliths or outcrop of oceanic lithosphere) and those imaged in classical seismological studies of the lithosphere.

  2. Origin of platinum-group mineral assemblages in a mantle tectonite at Unst deduced from mineral chemistry and osmium isotopes

    NASA Astrophysics Data System (ADS)

    Badanina, Inna Yu.; Lord, Richard A.; Malitch, Kreshimir N.; Meisel, Thomas C.

    2013-04-01

    assemblage is likely to reflect processes such as in-situ serpentinisation, alteration during emplacement or regional greenschist metamorphism. Whole-rock platinum-group element (PGE) concentrations give negatively sloped chondrite-normalized PGE patterns, typical of podiform chromitite, where refractory PGE (Os, Ir and Ru) prevail over less refractory PGE (Rh, Pt and Pd). The osmium isotope results identify similarly 'unradiogenic' 187Os/188Os values for 'primary' and 'secondary' PGM assemblages (with mean 187Os/188Os values of 0.12419 and 0.12464, respectively), being within uncertainty of the chromitite composition (0.1240±0.0006). This implies that the whole-rock Os isotope budget is largely controlled by laurite-dominant assemblages, supporting the conclusion that the 'secondary' PGM assemblage inherited the subchondritic osmium isotope signature of the 'primary' PGM. No evidence for other source contributions during later thermal events has been observed. The Os-isotope data provide further support for an Enstatite Chondrite Reservoir model for the convective upper mantle as defined by Walker et al. (2002) and are consistent with origin of the complex as a Caledonian ophiolite formed in a supra-subduction zone. This study was supported by Russian Foundation for Basic Research (grant 12-05-01166-a to IYuB) and the Uralian Division of Russian Academy of Sciences (project No 12-P-5-1020). References: Andrews, D.R.A., Brenan, J.M. (2002) Phase-equilibrium constraints on the magmatic origin of laurite and Os-Ir alloy. Can. Mineral. 40, 1705-1716. Walker, R.J., Prichard, H.M., Ishiwatari, A., Pimentel, M. (2002) The osmium isotopic composition of convecting upper mantle deduced from ophiolite chromites. Geochim. Cosmochim. Acta 66, 329-345.

  3. Modular design, application architecture, and usage of a self-service model for enterprise data delivery: The Duke Enterprise Data Unified Content Explorer (DEDUCE)

    PubMed Central

    Horvath, Monica M.; Rusincovitch, Shelley A.; Brinson, Stephanie; Shang, Howard C.; Evans, Steve; Ferranti, Jeffrey M.

    2015-01-01

    Purpose Data generated in the care of patients are widely used to support clinical research and quality improvement, which has hastened the development of self-service query tools. User interface design for such tools, execution of query activity, and underlying application architecture have not been widely reported, and existing tools reflect a wide heterogeneity of methods and technical frameworks. We describe the design, application architecture, and use of a self-service model for enterprise data delivery within Duke Medicine. Methods Our query platform, the Duke Enterprise Data Unified Content Explorer (DEDUCE), supports enhanced data exploration, cohort identification, and data extraction from our enterprise data warehouse (EDW) using a series of modular environments that interact with a central keystone module, Cohort Manager (CM). A data-driven application architecture is implemented through three components: an application data dictionary, the concept of “smart dimensions”, and dynamically-generated user interfaces. Results DEDUCE CM allows flexible hierarchies of EDW queries within a grid-like workspace. A cohort “join” functionality allows switching between filters based on criteria occurring within or across patient encounters. To date, 674 users have been trained and activated in DEDUCE, and logon activity shows a steady increase, with variability between months. A comparison of filter conditions and export criteria shows that these activities have different patterns of usage across subject areas. Conclusions Organizations with sophisticated EDWs may find that users benefit from development of advanced query functionality, complimentary to the user interfaces and infrastructure used in other well-published models. Driven by its EDW context, the DEDUCE application architecture was also designed to be responsive to source data and to allow modification through alterations in metadata rather than programming, allowing an agile response to source

  4. Isolation of a human anti-haemophilic factor IX cDNA clone using a unique 52-base synthetic oligonucleotide probe deduced from the amino acid sequence of bovine factor IX.

    PubMed

    Jaye, M; de la Salle, H; Schamber, F; Balland, A; Kohli, V; Findeli, A; Tolstoshev, P; Lecocq, J P

    1983-04-25

    A unique 52mer oligonucleotide deduced from the amino acid sequence of bovine Factor IX was synthesized and used as a probe to screen a human liver cDNA bank. The Factor IX clone isolated shows 5 differences in nucleotide and deduced amino acid sequence as compared to a previously isolated clone. In addition, precisely one codon has been deleted.Images

  5. Concentrations of carbonyl sulfide and hydrogen cyanide in the free upper troposphere and lower stratosphere deduced from ATMOS/Spacelab 3 infrared solar occultation spectra

    NASA Technical Reports Server (NTRS)

    Zander, R.; Rinsland, C. P.; Russell, J. M., III; Farmer, C. B.; Norton, R. H.

    1988-01-01

    This paper presents the results on the volume mixing ratio profiles of carbonyl sulfide and hydrogen cyanide, deduced from the spectroscopic analysis of IR solar absorption spectra obtained in the occultation mode with the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument during its mission aboard Spacelab 3. A comparison of the ATMOS measurements for both northern and southern latitudes with previous field investigations at low midlatitudes shows a relatively good agreement. Southern Hemisphere volume mixing ratio profiles for both molecules were obtained for the first time, as were the profiles for the Northern Hemisphere covering the upper troposphere and the lower stratosphere simultaneously.

  6. A Hypothesis: Life Initiated from Two Genes, as Deduced from the RNA World Hypothesis and the Characteristics of Life-Like Systems.

    PubMed

    Kawamura, Kunio

    2016-08-02

    RNA played a central role in the emergence of the first life-like system on primitive Earth since RNA molecules contain both genetic information and catalytic activity. However, there are several drawbacks regarding the RNA world hypothesis. Here, I briefly discuss the feasibility of the RNA world hypothesis to deduce the RNA functions that are essential for forming a life-like system. At the same time, I have conducted a conceptual analysis of the characteristics of biosystems as a useful approach to deduce a realistic life-like system in relation to the definition of life. For instance, an RNA-based life-like system should possess enough stability to resist environmental perturbations, by developing a cell-like compartment, for instance. Here, a conceptual viewpoint is summarized to provide a realistic life-like system that is compatible with the primitive Earth environment and the capabilities of RNA molecules. According to the empirical and conceptual analysis, I propose the hypothesis that the first life-like system could have initiated from only two genes.

  7. Evolutionary Steps in the Emergence of Life Deduced from the Bottom-Up Approach and GADV Hypothesis (Top-Down Approach).

    PubMed

    Ikehara, Kenji

    2016-01-01

    It is no doubt quite difficult to solve the riddle of the origin of life. So, firstly, I would like to point out the kinds of obstacles there are in solving this riddle and how we should tackle these difficult problems, reviewing the studies that have been conducted so far. After that, I will propose that the consecutive evolutionary steps in a timeline can be rationally deduced by using a common event as a juncture, which is obtained by two counter-directional approaches: one is the bottom-up approach through which many researchers have studied the origin of life, and the other is the top-down approach, through which I established the [GADV]-protein world hypothesis or GADV hypothesis on the origin of life starting from a study on the formation of entirely new genes in extant microorganisms. Last, I will describe the probable evolutionary process from the formation of Earth to the emergence of life, which was deduced by using a common event-the establishment of the first genetic code encoding [GADV]-amino acids-as a juncture for the results obtained from the two approaches.

  8. A Hypothesis: Life Initiated from Two Genes, as Deduced from the RNA World Hypothesis and the Characteristics of Life-Like Systems.

    PubMed

    Kawamura, Kunio

    2016-01-01

    RNA played a central role in the emergence of the first life-like system on primitive Earth since RNA molecules contain both genetic information and catalytic activity. However, there are several drawbacks regarding the RNA world hypothesis. Here, I briefly discuss the feasibility of the RNA world hypothesis to deduce the RNA functions that are essential for forming a life-like system. At the same time, I have conducted a conceptual analysis of the characteristics of biosystems as a useful approach to deduce a realistic life-like system in relation to the definition of life. For instance, an RNA-based life-like system should possess enough stability to resist environmental perturbations, by developing a cell-like compartment, for instance. Here, a conceptual viewpoint is summarized to provide a realistic life-like system that is compatible with the primitive Earth environment and the capabilities of RNA molecules. According to the empirical and conceptual analysis, I propose the hypothesis that the first life-like system could have initiated from only two genes. PMID:27490571

  9. A Hypothesis: Life Initiated from Two Genes, as Deduced from the RNA World Hypothesis and the Characteristics of Life-Like Systems

    PubMed Central

    Kawamura, Kunio

    2016-01-01

    RNA played a central role in the emergence of the first life-like system on primitive Earth since RNA molecules contain both genetic information and catalytic activity. However, there are several drawbacks regarding the RNA world hypothesis. Here, I briefly discuss the feasibility of the RNA world hypothesis to deduce the RNA functions that are essential for forming a life-like system. At the same time, I have conducted a conceptual analysis of the characteristics of biosystems as a useful approach to deduce a realistic life-like system in relation to the definition of life. For instance, an RNA-based life-like system should possess enough stability to resist environmental perturbations, by developing a cell-like compartment, for instance. Here, a conceptual viewpoint is summarized to provide a realistic life-like system that is compatible with the primitive Earth environment and the capabilities of RNA molecules. According to the empirical and conceptual analysis, I propose the hypothesis that the first life-like system could have initiated from only two genes. PMID:27490571

  10. Evolutionary Steps in the Emergence of Life Deduced from the Bottom-Up Approach and GADV Hypothesis (Top-Down Approach)

    PubMed Central

    Ikehara, Kenji

    2016-01-01

    It is no doubt quite difficult to solve the riddle of the origin of life. So, firstly, I would like to point out the kinds of obstacles there are in solving this riddle and how we should tackle these difficult problems, reviewing the studies that have been conducted so far. After that, I will propose that the consecutive evolutionary steps in a timeline can be rationally deduced by using a common event as a juncture, which is obtained by two counter-directional approaches: one is the bottom-up approach through which many researchers have studied the origin of life, and the other is the top-down approach, through which I established the [GADV]-protein world hypothesis or GADV hypothesis on the origin of life starting from a study on the formation of entirely new genes in extant microorganisms. Last, I will describe the probable evolutionary process from the formation of Earth to the emergence of life, which was deduced by using a common event—the establishment of the first genetic code encoding [GADV]-amino acids—as a juncture for the results obtained from the two approaches. PMID:26821048

  11. Structural basis for the methylation of A1408 in 16S rRNA by a panaminoglycoside resistance methyltransferase NpmA from a clinical isolate and analysis of the NpmA interactions with the 30S ribosomal subunit

    PubMed Central

    Husain, Nilofer; Obranić, Sonja; Koscinski, Lukasz; Seetharaman, J.; Babić, Fedora; Bujnicki, Janusz M.; Maravić-Vlahoviček, Gordana; Sivaraman, J.

    2011-01-01

    NpmA, a methyltransferase that confers resistance to aminoglycosides was identified in an Escherichia coli clinical isolate. It belongs to the kanamycin–apramycin methyltransferase (Kam) family and specifically methylates the 16S rRNA at the N1 position of A1408. We determined the structures of apo-NpmA and its complexes with S-adenosylmethionine (AdoMet) and S-adenosylhomocysteine (AdoHcy) at 2.4, 2.7 and 1.68 Å, respectively. We generated a number of NpmA variants with alanine substitutions and studied their ability to bind the cofactor, to methylate A1408 in the 30S subunit, and to confer resistance to kanamycin in vivo. Residues D30, W107 and W197 were found to be essential. We have also analyzed the interactions between NpmA and the 30S subunit by footprinting experiments and computational docking. Helices 24, 42 and 44 were found to be the main NpmA-binding site. Both experimental and theoretical analyses suggest that NpmA flips out the target nucleotide A1408 to carry out the methylation. NpmA is plasmid-encoded and can be transferred between pathogenic bacteria; therefore it poses a threat to the successful use of aminoglycosides in clinical practice. The results presented here will assist in the development of specific NpmA inhibitors that could restore the potential of aminoglycoside antibiotics. PMID:21062819

  12. Guanine nucleotide-binding proteins that enhance choleragen ADP-ribosyltransferase activity: nucleotide and deduced amino acid sequence of an ADP-ribosylation factor cDNA.

    PubMed Central

    Price, S R; Nightingale, M; Tsai, S C; Williamson, K C; Adamik, R; Chen, H C; Moss, J; Vaughan, M

    1988-01-01

    Three (two soluble and one membrane) guanine nucleotide-binding proteins (G proteins) that enhance ADP-ribosylation of the Gs alpha stimulatory subunit of the adenylyl cyclase (EC 4.6.1.1) complex by choleragen have recently been purified from bovine brain. To further define the structure and function of these ADP-ribosylation factors (ARFs), we isolated a cDNA clone (lambda ARF2B) from a bovine retinal library by screening with a mixed heptadecanucleotide probe whose sequence was based on the partial amino acid sequence of one of the soluble ARFs from bovine brain. Comparison of the deduced amino acid sequence of lambda ARF2B with sequences of peptides from the ARF protein (total of 60 amino acids) revealed only two differences. Whether these are cloning artifacts or reflect the existence of more than one ARF protein remains to be determined. Deduced amino acid sequences of ARF, Go alpha (the alpha subunit of a G protein that may be involved in regulation of ion fluxes), and c-Ha-ras gene product p21 show similarities in regions believed to be involved in guanine nucleotide binding and GTP hydrolysis. ARF apparently lacks a site analogous to that ADP-ribosylated by choleragen in G-protein alpha subunits. Although both the ARF proteins and the alpha subunits bind guanine nucleotides and serve as choleragen substrates, they must interact with the toxin A1 peptide in different ways. In addition to serving as an ADP-ribose acceptor, ARF interacts with the toxin in a manner that modifies its catalytic properties. PMID:3135549

  13. Genetic makeup of the Corynebacterium glutamicum LexA regulon deduced from comparative transcriptomics and in vitro DNA band shift assays.

    PubMed

    Jochmann, Nina; Kurze, Anna-Katharina; Czaja, Lisa F; Brinkrolf, Karina; Brune, Iris; Hüser, Andrea T; Hansmeier, Nicole; Pühler, Alfred; Borovok, Ilya; Tauch, Andreas

    2009-05-01

    The lexA gene of Corynebacterium glutamicum ATCC 13032 was deleted to create the mutant strain C. glutamicum NJ2114, which has an elongated cell morphology and an increased doubling time. To characterize the SOS regulon in C. glutamicum, the transcriptomes of NJ2114 and a DNA-damage-induced wild-type strain were compared with that of a wild-type control using DNA microarray hybridization. The expression data were combined with bioinformatic pattern searches for LexA binding sites, leading to the detection of 46 potential SOS boxes located upstream of differentially expressed transcription units. Binding of a hexahistidyl-tagged LexA protein to 40 double-stranded oligonucleotides containing the potential SOS boxes was demonstrated in vitro by DNA band shift assays. It turned out that LexA binds not only to SOS boxes in the promoter-operator region of upregulated genes, but also to SOS boxes detected upstream of downregulated genes. These results demonstrated that LexA controls directly the expression of at least 48 SOS genes organized in 36 transcription units. The deduced genes encode a variety of physiological functions, many of them involved in DNA repair and survival after DNA damage, but nearly half of them have hitherto unknown functions. Alignment of the LexA binding sites allowed the corynebacterial SOS box consensus sequence TcGAA(a/c)AnnTGTtCGA to be deduced. Furthermore, the common intergenic region of lexA and the differentially expressed divS-nrdR operon, encoding a cell division suppressor and a regulator of deoxyribonucleotide biosynthesis, was characterized in detail. Promoter mapping revealed differences in divS-nrdR expression during SOS response and normal growth conditions. One of the four LexA binding sites detected in the intergenic region is involved in regulating divS-nrdR transcription, whereas the other sites are apparently used for negative autoregulation of lexA expression.

  14. New constraints on the rupture process of the 1999 August 17 Izmit earthquake deduced from estimates of stress glut rate moments

    NASA Astrophysics Data System (ADS)

    Clévédé, E.; Bouin, M.-P.; Bukchin, B.; Mostinskiy, A.; Patau, G.

    2004-12-01

    This paper illustrates the use of integral estimates given by the stress glut rate moments of total degree 2 for constraining the rupture scenario of a large earthquake in the particular case of the 1999 Izmit mainshock. We determine the integral estimates of the geometry, source duration and rupture propagation given by the stress glut rate moments of total degree 2 by inverting long-period surface wave (LPSW) amplitude spectra. Kinematic and static models of the Izmit earthquake published in the literature are quite different from one another. In order to extract the characteristic features of this event, we calculate the same integral estimates directly from those models and compare them with those deduced from our inversion. While the equivalent rupture zone and the eastward directivity are consistent among all models, the LPSW solution displays a strong unilateral character of the rupture associated with a short rupture duration that is not compatible with the solutions deduced from the published models. With the aim of understand this discrepancy, we use simple equivalent kinematic models to reproduce the integral estimates of the considered rupture processes (including ours) by adjusting a few free parameters controlling the western and eastern parts of the rupture. We show that the joint analysis of the LPSW solution and source tomographies allows us to elucidate the scattering of source processes published for this earthquake and to discriminate between the models. Our results strongly suggest that (1) there was significant moment released on the eastern segment of the activated fault system during the Izmit earthquake; (2) the apparent rupture velocity decreases on this segment.

  15. Primary structure of the monomer of the 12S subunit of transcarboxylase as deduced from DNA and characterization of the product expressed in Escherichia coli.

    PubMed

    Thornton, C G; Kumar, G K; Haase, F C; Phillips, N F; Woo, S B; Park, V M; Magner, W J; Shenoy, B C; Wood, H G; Samols, D

    1993-09-01

    Transcarboxylase from Propionibacterium shermanii is a complex biotin-containing enzyme composed of 30 polypeptides of three different types: a hexameric central 12S subunit to which 6 outer 5S subunits are attached through 12 1.3S biotinyl subunits. The enzyme catalyzes a two-step reaction in which methylmalonyl coenzyme A and pyruvate serve as substrates to form propionyl coenzyme A (propionyl-CoA) and oxalacetate, the 12S subunit specifically catalyzing one of the two reactions. We report here the cloning, sequencing, and expression of the 12S subunit. The gene was identified by matching amino acid sequences derived from isolated authentic 12S peptides with the deduced sequence of an open reading frame present in a cloned P. shermanii genomic fragment known to contain the gene encoding the 1.3S biotinyl subunit. The cloned 12S gene encodes a protein of 604 amino acids and of M(r) 65,545. The deduced sequence shows regions of extensive homology with the beta subunit of mammalian propionyl-CoA carboxylase as well as regions of homology with acetyl-CoA carboxylase from several species. Two genomic fragments were subcloned into pUC19 in an orientation such that the 12S open reading frame could be expressed from the lac promoter of the vector. Crude extracts prepared from these cells contained an immunoreactive band on Western blots (immunoblots) which comigrated with authentic 12S. The Escherichia coli-expressed 12S was purified to apparent homogeneity by a three-step procedure and compared with authentic 12S from P. shermanii. Their quaternary structures were identical by electron microscopy, and the E. coli 12S preparation was fully active in the reactions catalyzed by this subunit. We conclude that we have cloned, sequenced, and expressed the 12S subunit which exists in a hexameric active form in E.coli. PMID:8366018

  16. Genetic makeup of the Corynebacterium glutamicum LexA regulon deduced from comparative transcriptomics and in vitro DNA band shift assays.

    PubMed

    Jochmann, Nina; Kurze, Anna-Katharina; Czaja, Lisa F; Brinkrolf, Karina; Brune, Iris; Hüser, Andrea T; Hansmeier, Nicole; Pühler, Alfred; Borovok, Ilya; Tauch, Andreas

    2009-05-01

    The lexA gene of Corynebacterium glutamicum ATCC 13032 was deleted to create the mutant strain C. glutamicum NJ2114, which has an elongated cell morphology and an increased doubling time. To characterize the SOS regulon in C. glutamicum, the transcriptomes of NJ2114 and a DNA-damage-induced wild-type strain were compared with that of a wild-type control using DNA microarray hybridization. The expression data were combined with bioinformatic pattern searches for LexA binding sites, leading to the detection of 46 potential SOS boxes located upstream of differentially expressed transcription units. Binding of a hexahistidyl-tagged LexA protein to 40 double-stranded oligonucleotides containing the potential SOS boxes was demonstrated in vitro by DNA band shift assays. It turned out that LexA binds not only to SOS boxes in the promoter-operator region of upregulated genes, but also to SOS boxes detected upstream of downregulated genes. These results demonstrated that LexA controls directly the expression of at least 48 SOS genes organized in 36 transcription units. The deduced genes encode a variety of physiological functions, many of them involved in DNA repair and survival after DNA damage, but nearly half of them have hitherto unknown functions. Alignment of the LexA binding sites allowed the corynebacterial SOS box consensus sequence TcGAA(a/c)AnnTGTtCGA to be deduced. Furthermore, the common intergenic region of lexA and the differentially expressed divS-nrdR operon, encoding a cell division suppressor and a regulator of deoxyribonucleotide biosynthesis, was characterized in detail. Promoter mapping revealed differences in divS-nrdR expression during SOS response and normal growth conditions. One of the four LexA binding sites detected in the intergenic region is involved in regulating divS-nrdR transcription, whereas the other sites are apparently used for negative autoregulation of lexA expression. PMID:19372162

  17. The localization of multiple sites on 16S RNA which are cross-linked to proteins S7 and S8 in Escherichia coli 30S ribosomal subunits by treatment with 2-iminothiolane.

    PubMed

    Wower, I; Brimacombe, R

    1983-03-11

    RNA-protein cross-links were introduced into E. coli 30S ribosomal subunits by reaction with 2-iminothiolane followed by a mild ultraviolet irradiation treatment. After removal of non-reacted protein and partial nuclease digestion of the cross-linked 16S RNA-protein moiety, a number of individual cross-linked complexes could be isolated and the sites of attachment of the proteins to the RNA determined. Protein S8 was cross-linked to the RNA at three different positions, within oligo-nucleotides encompassing positions 629-633, 651-654, and (tentatively) 593-597 in the 16S sequence. Protein S7 was cross-linked within two oligonucleotides encompassing positions 1238-1240, and 1377-1378. In addition, a site at position 723-724 was observed, cross-linked to protein S19, S20 or S21.

  18. Ribonucleic acid-protein cross-linking within the intact Escherichia coli ribosome, utilizing ethylene glycol bis[3-(2-ketobutyraldehyde) ether], a reversible, bifunctional reagent: identification of 30S proteins.

    PubMed

    Brewer, L A; Noller, H F

    1983-08-30

    To obtain detailed topographical information concerning the spatial arrangement of the multitude of ribosomal proteins with respect to specific sequences in the three RNA chains of intact ribosomes, a reagent capable of covalently and reversibly joining RNA to protein has been synthesized [Brewer, L.A., Goelz, S., & Noller, H. F. (1983) Biochemistry (preceding paper in this issue)]. This compound, ethylene glycol bis[3-(2-ketobutyraldehyde) ether] which we term "bikethoxal", possesses two reactive ends similar to kethoxal. Accordingly, it reacts selectively with guanine in single-stranded regions of nucleic acid and with arginine in protein. The cross-linking is reversible in that the arginine- and guanine-bikethoxal linkage can be disrupted by treatment with mild base, allowing identification of the linked RNA and protein components by standard techniques. Further, since the sites of kethoxal modification within the RNA sequences of intact subunits are known, the task of identifying the components of individual ribonucleoprotein complexes should be considerably simplified. About 15% of the ribosomal protein was covalently cross-linked to 16S RNA by bikethoxal under our standard reaction conditions, as monitored by comigration of 35S-labeled protein with RNA on Sepharose 4B in urea. Cross-linked 30S proteins were subsequently removed from 16S RNA by treatment with T1 ribonuclease and/or mild base cleavage of the reagent and were identified by two-dimensional polyacrylamide gel electrophoresis. The major 30S proteins found in cross-linked complexes are S4, S5, S6, S7, S8, S9 (S11), S16, and S18. The minor ones are S2, S3, S12, S13, S14, S15, and S17.

  19. The four hexamerin genes in the honey bee: structure, molecular evolution and function deduced from expression patterns in queens, workers and drones

    PubMed Central

    2010-01-01

    Background Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens. Results The hexamerin genes of the honey bee (hex 70a, hex 70b, hex 70c and hex 110) diverge considerably in structure, so that the overall amino acid identity shared among their deduced protein subunits varies from 30 to 42%. Bioinformatics search for motifs in the respective upstream control regions (UCRs) revealed six overrepresented motifs including a potential binding site for Ultraspiracle (Usp), a target of juvenile hormone (JH). The expression of these genes was induced by topical application of JH on worker larvae. The four genes are highly transcribed by the larval fat body, although with significant differences in transcript levels, but only hex 110 and hex 70a are re-induced in the adult fat body in a caste- and sex-specific fashion, workers showing the highest expression. Transcripts for hex 110, hex 70a and hex70b were detected in developing ovaries and testes, and hex 110 was highly transcribed in the ovaries of egg-laying queens. A phylogenetic analysis revealed that HEX 110 is located at the most basal position among the holometabola hexamerins, and like HEX 70a and HEX 70c, it shares potential orthology relationship with hexamerins from other hymenopteran species. Conclusions Striking differences were found in the structure and developmental expression of the four hexamerin genes in the honey bee. The presence of a potential binding site for Usp in the respective 5' UCRs, and the results of experiments on JH level manipulation in vivo support the hypothesis of regulation by JH. Transcript levels and patterns in the fat body and gonads suggest that

  20. Assessment of volatile compound profiles and the deduced sensory significance of virgin olive oils from the progeny of Picual×Arbequina cultivars.

    PubMed

    Pérez, Ana G; de la Rosa, Raúl; Pascual, Mar; Sánchez-Ortiz, Araceli; Romero-Segura, Carmen; León, Lorenzo; Sanz, Carlos

    2016-01-01

    Volatile compounds are responsible for most of the sensory qualities of virgin olive oil and they are synthesized when enzymes and substrates come together as olive fruit is crushed during the industrial process to obtain the oil. Here we have studied the variability among the major volatile compounds in virgin olive oil prepared from the progeny of a cross of Picual and Arbequina olive cultivars (Olea europaea L.). The volatile compounds were isolated by SPME, and analyzed by HRGC-MS and HRGC-FID. Most of the volatile compounds found in the progeny's oil are produced by the enzymes in the so-called lipoxygenase pathway, and they may be clustered into different groups according to their chain length and polyunsaturated fatty acid origin (linoleic and linolenic acids). In addition, a group of compounds derived from amino acid metabolism and two terpenes also contributed significantly to the volatile fraction, some of which had significant odor values in most of the genotypes evaluated. The volatile compound content of the progeny was very varied, widely transgressing the progenitor levels, suggesting that in breeding programs it might be more effective to consider a larger number of individuals within the same cross than using different crosses with fewer individuals. Multivariate analysis allowed genotypes with particularly interesting volatile compositions to be identified and their flavor quality deduced.

  1. Sequence of cDNA for rat cystathionine gamma-lyase and comparison of deduced amino acid sequence with related Escherichia coli enzymes.

    PubMed Central

    Erickson, P F; Maxwell, I H; Su, L J; Baumann, M; Glode, L M

    1990-01-01

    A cDNA clone for cystathionine gamma-lyase was isolated from a rat cDNA library in lambda gt11 by screening with a monospecific antiserum. The identity of this clone, containing 600 bp proximal to the 3'-end of the gene, was confirmed by positive hybridization selection. Northern-blot hybridization showed the expected higher abundance of the corresponding mRNA in liver than in brain. Two further cDNA clones from a plasmid pcD library were isolated by colony hybridization with the first clone and were found to contain inserts of 1600 and 1850 bp. One of these was confirmed as encoding cystathionine gamma-lyase by hybridization with two independent pools of oligodeoxynucleotides corresponding to partial amino acid sequence information for cystathionine gamma-lyase. The other clone (estimated to represent all but 8% of the 5'-end of the mRNA) was sequenced and its deduced amino acid sequence showed similarity to those of the Escherichia coli enzymes cystathionine beta-lyase and cystathionine gamma-synthase throughout its length, especially to that of the latter. Images Fig. 1. Fig. 2. Fig. 3. Fig. 5. PMID:2201285

  2. Primary structure of human corticosteroid binding globulin, deduced from hepatic and pulmonary cDNAs, exhibits homology with serine protease inhibitors

    SciTech Connect

    Hammond, G.L.; Smith, C.L.; Goping, I.S.; Underhill, D.A.

    1987-08-01

    The authors have isolated and sequenced cDNAs for corticosteroid binding globulin (CBG) prepared from human liver and lung mRNAs. The results indicate that CBG mRNA is relatively abundant in the liver but is also present in the lung, testis, and kidney. The liver CBG cDNA contains an open reading frame for a 405-amino acid (M/sub r/ 45,149) polypeptide. This includes a predominantly hydrophobic, leader sequence of 22 residues that precedes the known NH/sub 2/-terminal sequence of human CBG. We, therefore, predict that the mature protein is composed of 383 amino acids and is a polypeptide of M/sub r/ 42,646. A second, in-frame, 72-base-pair cistron of unknown significance exists between the TAA termination codon for CBG and a possible polyadenylylation signal (AATAAA) located 16 nucleotides before the polyadenylylation site. The deduced amino acid sequence of mature CBG contains two cysteine residues and consensus sequences for the attachment of six possible N-linked oligosaccharide chains. The sequences of the human lung and liver CBG cDNAs differ by only one nucleotide within the proposed leader sequence,and they attribute this to a point mutation. No sequence homology was found between CBG and other steroid binding proteins, but there is a remarkable similarity between the amino acid sequences of CBG and of ..cap alpha../sub 1/-antitrypsin, and this extends to other members of the serpin (serine protease inhibitor) superfamily

  3. Metabolic Switches and Adaptations Deduced from the Proteomes of Streptomyces coelicolor Wild Type and phoP Mutant Grown in Batch Culture*

    PubMed Central

    Thomas, Louise; Hodgson, David A.; Wentzel, Alexander; Nieselt, Kay; Ellingsen, Trond E.; Moore, Jonathan; Morrissey, Edward R.; Legaie, Roxane; Wohlleben, Wolfgang; Rodríguez-García, Antonio; Martín, Juan F.; Burroughs, Nigel J.; Wellington, Elizabeth M. H.; Smith, Margaret C. M.

    2012-01-01

    Bacteria in the genus Streptomyces are soil-dwelling oligotrophs and important producers of secondary metabolites. Previously, we showed that global messenger RNA expression was subject to a series of metabolic and regulatory switches during the lifetime of a fermentor batch culture of Streptomyces coelicolor M145. Here we analyze the proteome from eight time points from the same fermentor culture and, because phosphate availability is an important regulator of secondary metabolite production, compare this to the proteome of a similar time course from an S. coelicolor mutant, INB201 (ΔphoP), defective in the control of phosphate utilization. The proteomes provide a detailed view of enzymes involved in central carbon and nitrogen metabolism. Trends in protein expression over the time courses were deduced from a protein abundance index, which also revealed the importance of stress pathway proteins in both cultures. As expected, the ΔphoP mutant was deficient in expression of PhoP-dependent genes, and several putatively compensatory metabolic and regulatory pathways for phosphate scavenging were detected. Notably there is a succession of switches that coordinately induce the production of enzymes for five different secondary metabolite biosynthesis pathways over the course of the batch cultures. PMID:22147733

  4. Deducing the nature of dark matter from direct and indirect detection experiments in the absence of collider signatures of new physics

    SciTech Connect

    Beltran, Maria; Hooper, Dan; Kolb, Edward W.; Krusberg, Zosia A. C.

    2009-08-15

    Despite compelling arguments that significant discoveries of physics beyond the standard model are likely to be made at the Large Hadron Collider, it remains possible that this machine will make no such discoveries, or will make no discoveries directly relevant to the dark matter problem. In this article, we study the ability of astrophysical experiments to deduce the nature of dark matter in such a scenario. In most dark matter studies, the relic abundance and detection prospects are evaluated within the context of some specific particle physics model or models (e.g., supersymmetry). Here, assuming a single weakly interacting massive particle constitutes the Universe's dark matter, we attempt to develop a model-independent approach toward the phenomenology of such particles in the absence of any discoveries at the Large Hadron Collider. In particular, we consider generic fermionic or scalar dark matter particles with a variety of interaction forms, and calculate the corresponding constraints from and sensitivity of direct and indirect detection experiments. The results may provide some guidance in disentangling information from future direct and indirect detection experiments.

  5. Experimental and data analysis techniques for deducing collision-induced forces from photographic histories of engine rotor fragment impact/interaction with a containment ring

    NASA Technical Reports Server (NTRS)

    Yeghiayan, R. P.; Leech, J. W.; Witmer, E. A.

    1973-01-01

    An analysis method termed TEJ-JET is described whereby measured transient elastic and inelastic deformations of an engine-rotor fragment-impacted structural ring are analyzed to deduce the transient external forces experienced by that ring as a result of fragment impact and interaction with the ring. Although the theoretical feasibility of the TEJ-JET concept was established, its practical feasibility when utilizing experimental measurements of limited precision and accuracy remains to be established. The experimental equipment and the techniques (high-speed motion photography) employed to measure the transient deformations of fragment-impacted rings are described. Sources of error and data uncertainties are identified. Techniques employed to reduce data reading uncertainties and to correct the data for optical-distortion effects are discussed. These procedures, including spatial smoothing of the deformed ring shape by Fourier series and timewise smoothing by Gram polynomials, are applied illustratively to recent measurements involving the impact of a single T58 turbine rotor blade against an aluminum containment ring. Plausible predictions of the fragment-ring impact/interaction forces are obtained by one branch of this TEJ-JET method; however, a second branch of this method, which provides an independent estimate of these forces, remains to be evaluated.

  6. Deduced consensus sequence of Sindbis virus strain AR339: mutations contained in laboratory strains which affect cell culture and in vivo phenotypes.

    PubMed Central

    McKnight, K L; Simpson, D A; Lin, S C; Knott, T A; Polo, J M; Pence, D F; Johannsen, D B; Heidner, H W; Davis, N L; Johnston, R E

    1996-01-01

    The consensus sequence of the Sindbis virus AR339 isolate, the prototype alphavirus, has been deduced. THe results presented here suggest (i) that a substantial proportion of the sequence divergence evident between the consensus sequence and sequences of laboratory strains of AR339 has resulted from selection for efficient growth in cell culture, (ii) that many of these changes affect the virulence of the virus in animal models, and (iii) that such modified genetic backgrounds present in laboratory strains can exert a significant influence on genetic studies of virus pathogenesis and host range. A laboratory strain of Sindbis virus AR339 was sequenced and cloned as a cDNA (pTRSB) from which infectious virus (TRSB) could be derived. The consensus sequence was deduced from the complete sequences of pTRSB and HRsp (E. G. Strauss, C. M. Rice, and J. H. Strauss, Virology 133:92-110, 1984), from partial sequences of the glycoprotein genes of three other AR339 laboratory strains, and by comparison with the sequences of the glycoprotein genes of three other AR339 sequence. HRsp differed form the consensus sequence by eight coding changes, and TRSB differed by three coding changes. In the 5' untranslated region, HRsp differed from the consensus sequence at nucleotide (nt) 5. These differences were likely the result of cell culture passage of the original AR339 isolate. At three of the difference loci (one in TRSB and two in HRsp), selection of cell-culture-adaptive mutations was documented with Sindbis virus or other alphaviruses. Selection in cell culture often results in attenuation of virulence in animals. Considering the TRSB and HRsp sequences together, one noncoding difference from the consensus (an A-for-G substitution in the 5' untranslated region at nt 5) and six coding differences in the glycoprotein genes (at E2 amino acids 1, 3, 70, and 172 and at E1 amino acids 72 and 237) were at loci which, either individually or in combination, significantly affected

  7. The application of striation analysis and focal mechanism stress inversion in deducing the kinematic history of faults: Examples from the Bristol Channel UK and the Ionian Zone Greece

    NASA Astrophysics Data System (ADS)

    Melis, Nikolaos S.; Miliorizos, Marios N.; Oshoano Aipoh, Hilary

    2013-04-01

    The present work compliments the application of a methodology, in reviewing and investigating further the kinematic history of faults, based on striation analysis and stress inversion of earthquake focal mechanisms and combines them to refine tectonic modelling and hence improve further hazard assessment. Two areas are chosen for this application: the Bristol Channel, UK and the Ionian Zone, Greece. Striation analysis is carried out in two complementary fault terranes. The first along the northern margin of the Inner Bristol Channel, UK, offers a natural laboratory to study in detail the reactivation history of the inverted Bristol Channel basin; and, the second along the north western coastline of the Ionian Zone, Greece, presents an opportunity to illustrate the relationship between movement of a framework of faults within the external orogenic zone of the Hellenides and the stress deduced from focal mechanisms of earthquakes in the region. The UK example reveals phases of Mesozoic negative inversion of Late Palaeozoic basement frontal and oblique ramp thrust faults, followed by Caenozoic positive inversions of Mesozoic normal and strike slip faults. The Greek example shows an equally composite history of faulting; Tethyan basement strata contain normal faults that pass up sequence and across unconformities into Mesozoic and Caenozoic strata, with thrusts and positively inverted faults recording typical dextral transpression. The fault framework in older strata and the veneers of Recent strata above them display Neotectonic fault histories of sinistral transtension, in addition to the transpression. Since the Ionian Zone lies suitably in the external zone, deformation favours the reactivation of fault lineaments, rather than the genesis of pristine faults. Both examples are used to demonstrate this structural principle. Focal mechanisms of Greek earthquake data are used in stress inversion and the results are applied upon the inherited fault framework and are

  8. Long term carbon dioxide exchange above a mixed forest in the Belgian Ardennes: evaluation of different approaches to deduce total ecosystem respiration from Eddy covariance measurements

    NASA Astrophysics Data System (ADS)

    Jérôme, Elisabeth; Aubinet, Marc; Heinesch, Bernard

    2010-05-01

    The general aim of this research is to analyze inter annual variability of carbon dioxide (CO2) fluxes exchanged by a mixed forest located at the Vielsalm experimental site in Belgium. At this site, CO2 flux measurements started in 1996 and are still going on. Thirteen complete years of measurements are thus available. Net Ecosystem Exchange (NEE) inter annual variability may be driven by gross primary productivity (GPP) or Total Ecosystem Respiration (TER), which should thus be both quantified. Using flux partitioning methods, TER is deduced from NEE measurements. GPP is then obtained by subtracting TER from NEE. Initially, a robust estimation of TER is required. This work seeks to compare two independent approaches to assess TER in order to quantify the implications on inter-annual variability. The comparison was performed on twelve complete years. TER estimates can be deduced by extrapolating to the whole day NEE measurements taken during selected night or day periods. In both case, the extrapolation is performed by using a respiration response to temperature. The first approach, referred as the night-time approach, consisted in calculating TER using a temperature response function derived from night-time data sets (Reichstein et al., 2005). The second approach, referred as the daytime approach, consisted in assessing TER from the intercept of the NEE/Photosynthetically Photon Flux Density (PPFD) response (Wohlfahrt et al., 2005). For each approach, different modalities were compared: the use of long term (annual) or short term (15 days) data sets for the night-time approach and the use of different types of regression for the daytime approach. In addition, the impact of the temperature choice was studied for each of the approaches. For the night-time approach, main results showed that air temperature sensitivity of ecosystem respiration derived from annual data did not reflect the short-term air temperature sensitivity. Vielsalm is a summer active ecosystem

  9. How to deduce and teach the logical and unambiguous answer, namely L = ∑C, to “What is Life?” using the principles of communication?

    PubMed Central

    De Loof, Arnold

    2015-01-01

    Is it possible to understand the very nature of ‘Life’ and ‘Death’ based on contemporary biology? The usual spontaneous reaction is: “No way. Life is far too complicated. It involves both material- and an immaterial dimensions, and this combination exceeds the capacities of the human brain.” In this paper, a fully contrarian stand is taken. Indeed it will be shown that without invoking any unknown principle(s) unambiguous definitions can be logically deduced. The key? First ask the right questions. Next, thoroughly imbue contemporary biology with the principles of communication, including both its ‘hardware’ and its ‘software’ aspects. An integrative yet simple principle emerges saying that: 1. All living matter is invariably organized as sender-receiver compartments that incessantly handle and transfer information (= communicate); 2. The ‘communicating compartment’ is better suited to serve as universal unit of structure, function and evolution than ‘the (prokaryotic) cell’, the smallest such unit; 3. ‘Living matter’ versus ‘non-living’ are false opposites while ‘still alive’ and ‘just not alive anymore’ are true opposites; 4. ‘Death’ ensues when a given sender-receiver compartment irreversibly loses its ability to handle information at its highest level of compartmental organization; 5. The verb ‘Life’ (L) denotes nothing else than the total sum (∑) of all acts of communication (C) executed by a sender-receiver at all its levels of compartmental organization: L = ∑C; 6. Any act of communication is a problem-solving act; 6. Any Extended Evolutionary Synthesis (EES) should have the definition of Life at its core. PMID:27064373

  10. How to deduce and teach the logical and unambiguous answer, namely L = ∑C, to "What is Life?" using the principles of communication?

    PubMed

    De Loof, Arnold

    2015-01-01

    Is it possible to understand the very nature of 'Life' and 'Death' based on contemporary biology? The usual spontaneous reaction is: "No way. Life is far too complicated. It involves both material- and an immaterial dimensions, and this combination exceeds the capacities of the human brain." In this paper, a fully contrarian stand is taken. Indeed it will be shown that without invoking any unknown principle(s) unambiguous definitions can be logically deduced. The key? First ask the right questions. Next, thoroughly imbue contemporary biology with the principles of communication, including both its 'hardware' and its 'software' aspects. An integrative yet simple principle emerges saying that: 1. All living matter is invariably organized as sender-receiver compartments that incessantly handle and transfer information (= communicate); 2. The 'communicating compartment' is better suited to serve as universal unit of structure, function and evolution than 'the (prokaryotic) cell', the smallest such unit; 3. 'Living matter' versus 'non-living' are false opposites while 'still alive' and 'just not alive anymore' are true opposites; 4. 'Death' ensues when a given sender-receiver compartment irreversibly loses its ability to handle information at its highest level of compartmental organization; 5. The verb 'Life' (L) denotes nothing else than the total sum (∑) of all acts of communication (C) executed by a sender-receiver at all its levels of compartmental organization: L = ∑C; 6. Any act of communication is a problem-solving act; 6. Any Extended Evolutionary Synthesis (EES) should have the definition of Life at its core. PMID:27064373

  11. How to deduce and teach the logical and unambiguous answer, namely L = ∑C, to "What is Life?" using the principles of communication?

    PubMed

    De Loof, Arnold

    2015-01-01

    Is it possible to understand the very nature of 'Life' and 'Death' based on contemporary biology? The usual spontaneous reaction is: "No way. Life is far too complicated. It involves both material- and an immaterial dimensions, and this combination exceeds the capacities of the human brain." In this paper, a fully contrarian stand is taken. Indeed it will be shown that without invoking any unknown principle(s) unambiguous definitions can be logically deduced. The key? First ask the right questions. Next, thoroughly imbue contemporary biology with the principles of communication, including both its 'hardware' and its 'software' aspects. An integrative yet simple principle emerges saying that: 1. All living matter is invariably organized as sender-receiver compartments that incessantly handle and transfer information (= communicate); 2. The 'communicating compartment' is better suited to serve as universal unit of structure, function and evolution than 'the (prokaryotic) cell', the smallest such unit; 3. 'Living matter' versus 'non-living' are false opposites while 'still alive' and 'just not alive anymore' are true opposites; 4. 'Death' ensues when a given sender-receiver compartment irreversibly loses its ability to handle information at its highest level of compartmental organization; 5. The verb 'Life' (L) denotes nothing else than the total sum (∑) of all acts of communication (C) executed by a sender-receiver at all its levels of compartmental organization: L = ∑C; 6. Any act of communication is a problem-solving act; 6. Any Extended Evolutionary Synthesis (EES) should have the definition of Life at its core.

  12. Use of primary deuterium and /sup 15/N isotope effects to deduce the relative rates of steps in the mechanisms of alanine and glutamate dehydrogenases

    SciTech Connect

    Weiss, P.M.; Chen, C.Y.; Cleland, W.W.; Cook, P.F.

    1988-06-28

    The authors have used deuterium and /sup 15/N isotope effects to study the relative rates of the steps in the mechanisms of alanine and glutamate dehydrogenases. The proposed chemical mechanisms for these enzymes involve carbinolamine formation, imine formation, and reduction of the imine to the amino acid. These steps are almost equally rate limiting for V/K/sub ammonia/ with alanine dehydrogenase, while with glutamate dehydrogenase carbinolamine formation, imine formation, and release of glutamate after hydride transfer provide most of the rate limitation of V/K/sub ammonia/. Release of oxidized nucleotide is largely rate limiting for V/sub max/ for both enzymes. When ..beta..-hydroxypyruvate replaces pyruvate, or 3-acetylpyridine NADH (Acpyr-NADH) or thio-NADH replaces NADH with alanine dehydrogenase, nucleotide release no longer limits V/sub max/, and hydride transfer becomes more rate limiting. With glutamate dehydrogenase, replacement of ..cap alpha..-ketoglutarate by ..cap alpha..-ketovalerate makes hydride transfer more rate limiting. Use of Acpyr-NADPH has a minimal effect with ..cap alpha..-ketoglutarate but causes an 8-fold decrease in V/sub max/ with ..cap alpha..-ketovalerate, with hydride transfer the major rate-limiting step. In contrast, thio-NADPH with either ..cap alpha..-keto acid causes carbinolamide formation to become almost completely rate limiting. These studies show the power of multiple isotope effects in deducing details of the chemistry and changes in rate-limiting step(s) in complicated reaction mechanisms such as those of alanine and glutamate dehydrogenases.

  13. Metabolic and evolutionary insights into the closely-related species Streptomyces coelicolor and Streptomyces lividans deduced from high-resolution comparative genomic hybridization

    PubMed Central

    2010-01-01

    Background Whilst being closely related to the model actinomycete Streptomyces coelicolor A3(2), S. lividans 66 differs from it in several significant and phenotypically observable ways, including antibiotic production. Previous comparative gene hybridization studies investigating such differences have used low-density (one probe per gene) PCR-based spotted arrays. Here we use new experimentally optimised 104,000 × 60-mer probe arrays to characterize in detail the genomic differences between wild-type S. lividans 66, a derivative industrial strain, TK24, and S. coelicolor M145. Results The high coverage and specificity (detection of three nucleotide differences) of the new microarrays used has highlighted the macroscopic genomic differences between two S. lividans strains and S. coelicolor. In a series of case studies we have validated the microarray and have identified subtle changes in genomic structure which occur in the Asp-activating adenylation domains of CDA non-ribosomal peptide synthetase genes which provides evidence of gene shuffling between these domains. We also identify single nucleotide sequence inter-species differences which exist in the actinorhodin biosynthetic gene cluster. As the glyoxylate bypass is non-functional in both S. lividans strains due to the absence of the gene encoding isocitrate lyase it is likely that the ethylmalonyl-CoA pathway functions as the alternative mechanism for the assimilation of C2 compounds. Conclusions This study provides evidence for widespread genetic recombination, rather than it being focussed at 'hotspots', suggesting that the previously proposed 'archipelago model' of genomic differences between S. coelicolor and S. lividans is unduly simplistic. The two S. lividans strains investigated differ considerably in genetic complement, with TK24 lacking 175 more genes than its wild-type parent when compared to S. coelicolor. Additionally, we confirm the presence of bldB in S. lividans and deduce that S. lividans 66

  14. Impact delivery of organic matter on the acapulcoite-lodranite parent-body deduced from C, N isotopes and nanostructures of carbon phases in Acapulco and Lodran

    NASA Astrophysics Data System (ADS)

    Charon, E.; Aléon, J.; Rouzaud, J.-N.

    2014-10-01

    Lodran. Carbon phases in Lodran would have been formed by the secondary carbonization of hydrocarbon fluids released during the primary carbonization of IOM. In the framework of this model, the C isotopic compositions can be reproduced using Rayleigh distillation at each carbonization step and the N isotopic compositions can be understood as resulting from the variable loss and preservation of 15N-rich nitriles (δ15N ∼ +800‰) and 15N-poor pyrroles (δ15N = -140‰) during carbonization. The combined interpretation of the temperatures deduced from this model, petrographic cooling rates, and thermochronological indicators suggest that the CI-CM IOM could have been introduced in the parent-body by an impact, about 10 Myr after solar system formation.

  15. Pu236(n,f), Pu237(n,f), and Pu238(n,f) cross sections deduced from (p,t), (p,d), and (p,p') surrogate reactions

    NASA Astrophysics Data System (ADS)

    Hughes, R. O.; Beausang, C. W.; Ross, T. J.; Burke, J. T.; Casperson, R. J.; Cooper, N.; Escher, J. E.; Gell, K.; Good, E.; Humby, P.; McCleskey, M.; Saastimoinen, A.; Tarlow, T. D.; Thompson, I. J.

    2014-07-01

    The Pu236(n,f), Pu237(n,f) and Pu238(n,f) cross sections have been inferred by utilizing the surrogate ratio method. Targets of Pu239 and U235 were bombarded with 28.5-MeV protons, and the light ion recoils, as well as fission fragments, were detected using the STARS detector array at the K150 Cyclotron at the Texas A&M cyclotron facility. The (p, tf) reaction on Pu239 and U235 targets was used to deduce the σ (Pu236(n ,f))/σ(U232(n,f)) ratio, and the Pu236(n,f) cross section was subsequently determined for En=0.5-7.5 MeV. Similarly, the (p,df) reaction on the same two targets was used to deduce the σ(Pu237(n ,f))/σ(U233(n,f)) ratio, and the Pu237(n,f) cross section was extracted in the energy range En=0.5-7 MeV. The Pu238(n,f) cross section was also deduced by utilizing the (p,p') reaction channel on the same targets. There is good agreement with the recent ENDF/B-VII.1 evaluated cross section data for Pu238(n,f) in the range En=0.5-10.5 MeV and for Pu237(n,f) in the range En=0.5-7 MeV; however, the Pu236(n,f) cross section deduced in the present work is higher than the evaluation between 2 and 7 MeV.

  16. Deduced amino acid sequence of the small hydrophobic protein of US avian pneumovirus has greater identity with that of human metapneumovirus than those of non-US avian pneumoviruses.

    PubMed

    Yunus, Abdul S; Govindarajan, Dhanasekaran; Huang, Zhuhui; Samal, Siba K

    2003-05-01

    We report here the nucleotide and deduced amino acid (aa) sequences of the small hydrophobic (SH) gene of the avian pneumovirus strain Colorado (APV/CO). The SH gene of APV/CO is 628 nucleotides in length from gene-start to gene-end. The longest ORF of the SH gene encoded a protein of 177 aas in length. Comparison of the deduced aa sequence of the SH protein of APV/CO with the corresponding published sequences of other members of genera metapneumovirus showed 28% identity with the newly discovered human metapneumovirus (hMPV), but no discernable identity with the APV subgroup A or B. Collectively, this data supports the hypothesis that: (i) APV/CO is distinct from European APV subgroups and belongs to the novel subgroup APV/C (APV/US); (ii) APV/CO is more closely related to hMPV, a mammalian metapneumovirus, than to either APV subgroup A or B. The SH gene of APV/CO was cloned using a genomic walk strategy which initiated cDNA synthesis from genomic RNA that traversed the genes in the order 3'-M-F-M2-SH-G-5', thus confirming that gene-order of APV/CO conforms in the genus Metapneumovirus. We also provide the sequences of transcription-signals and the M-F, F-M2, M2-SH and SH-G intergenic regions of APV/CO.

  17. cDNA cloning and deduced amino acid sequence of a major, glycine-rich cuticular protein from the coleopteran Tenebrio molitor. Temporal and spatial distribution of the transcript during metamorphosis.

    PubMed

    Charles, J P; Bouhin, H; Quennedey, B; Courrent, A; Delachambre, J

    1992-06-15

    In Coleoptera, the elytra (forewings), with a very hard and thick cuticle, protect the membranous and delicate hindwings against mechanical stress. We have isolated and characterized a cDNA encoding a major cuticle protein in Tenebrio molitor, named ACP-20. The deduced amino acid sequence is roughly tripartite, with two terminal glycine-rich domains and a central region showing pronounced similarities with some other hard cuticle proteins. Northern blot and in situ hybridization analyses reveal that ACP-20 gene expression is developmentally regulated since transcript accumulation occurs only in epidermal regions synthesizing hard cuticle and is restricted to the period of preecdysial adult cuticle deposition. Moreover, application of a juvenile hormone analogue prevents the appearance of the transcript, indicating that juvenile hormone, a key molecule involved in the control of insect metamorphosis, negatively regulates the expression of the ACP-20 gene.

  18. On a Riesz basis of exponentials related to the eigenvalues of an analytic operator and application to a non-selfadjoint problem deduced from a perturbation method for sound radiation

    SciTech Connect

    Ellouz, Hanen; Feki, Ines; Jeribi, Aref

    2013-11-15

    In the present paper, we prove that the family of exponentials associated to the eigenvalues of the perturbed operator T(ε) ≔ T{sub 0} + εT{sub 1} + ε{sup 2}T{sub 2} + … + ε{sup k}T{sub k} + … forms a Riesz basis in L{sup 2}(0, T), T > 0, where ε∈C, T{sub 0} is a closed densely defined linear operator on a separable Hilbert space H with domain D(T{sub 0}) having isolated eigenvalues with multiplicity one, while T{sub 1}, T{sub 2}, … are linear operators on H having the same domain D⊃D(T{sub 0}) and satisfying a specific growing inequality. After that, we generalize this result using a H-Lipschitz function. As application, we consider a non-selfadjoint problem deduced from a perturbation method for sound radiation.

  19. Deducing dust emission mechanisms from field measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field observations are needed to both develop and test theories on dust emission for use in global modeling systems. The mechanism of dust emission (aerodynamic entrainment, saltation bombardment, aggregate disintegration) and the amount and particle-size distribution of emitted dust may vary under ...

  20. "Le Theatre d'Education": An Introduction.

    ERIC Educational Resources Information Center

    Levy, Jonathan

    2003-01-01

    Considers how in the past 15 years, with renewed interest in women writers and education for girls, there has been a revival of interest in the Theatre of Education, a large, coherent body of plays for children written in Europe and America between 1750 and 1830. Discusses plays written for children from the 1500s to the early 1900s. (SG)

  1. Primary structure of the T3 gamma subunit of the T3/T cell antigen receptor complex deduced from cDNA sequences: evolution of the T3 gamma and delta subunits.

    PubMed Central

    Krissansen, G W; Owen, M J; Verbi, W; Crumpton, M J

    1986-01-01

    cDNA clones, whose fusion proteins were recognised by an anti-(T3 gamma chain) serum, were isolated from a lambda gt11 expression library prepared from the human T leukaemia cell line J6. The clones encoded a unique sequence related to that of the T3 delta chain, and hybridised to two mRNA transcripts of 0.8 and 3.5 kb in size, whose expression was restricted to T lymphocytes. The 182 amino acid sequence deduced from the cDNA revealed a typical signal peptide, a predominantly hydrophilic 89 amino residue domain with two N-glycosylation sites, a hydrophobic domain with a centrally located glutamic acid residue and a 44-residue domain with at least one potential serine phosphorylation site for protein kinase C. Given this arrangement the T3 gamma polypeptide most probably has a transmembrane orientation with the N-terminal domain exposed on the cell surface. The amino acid and nucleotide sequences showed marked homology with those of the T3 delta chain, suggesting that the respective genes arose by duplication about 200 million years ago. The intracellular and membrane-proximal half of the extracellular domains were especially well conserved. Images Fig. 1. Fig. 5. PMID:2944745

  2. Density functional theory-based simulations of sum frequency generation spectra involving methyl stretching vibrations: effect of the molecular model on the deduced molecular orientation and comparison with an analytical approach

    NASA Astrophysics Data System (ADS)

    Cecchet, F.; Lis, D.; Caudano, Y.; Mani, A. A.; Peremans, A.; Champagne, B.; Guthmuller, J.

    2012-03-01

    The knowledge of the first hyperpolarizability tensor elements of molecular groups is crucial for a quantitative interpretation of the sum frequency generation (SFG) activity of thin organic films at interfaces. Here, the SFG response of the terminal methyl group of a dodecanethiol (DDT) monolayer has been interpreted on the basis of calculations performed at the density functional theory (DFT) level of approximation. In particular, DFT calculations have been carried out on three classes of models for the aliphatic chains. The first class of models consists of aliphatic chains, containing from 3 to 12 carbon atoms, in which only one methyl group can freely vibrate, while the rest of the chain is frozen by a strong overweight of its C and H atoms. This enables us to localize the probed vibrational modes on the methyl group. In the second class, only one methyl group is frozen, while the entire remaining chain is allowed to vibrate. This enables us to analyse the influence of the aliphatic chain on the methyl stretching vibrations. Finally, the dodecanethiol (DDT) molecule is considered, for which the effects of two dielectrics, i.e. n-hexane and n-dodecane, are investigated. Moreover, DDT calculations are also carried out by using different exchange-correlation (XC) functionals in order to assess the DFT approximations. Using the DFT IR vectors and Raman tensors, the SFG spectrum of DDT has been simulated and the orientation of the methyl group has then been deduced and compared with that obtained using an analytical approach based on a bond additivity model. This analysis shows that when using DFT molecular properties, the predicted orientation of the terminal methyl group tends to converge as a function of the alkyl chain length and that the effects of the chain as well as of the dielectric environment are small. Instead, a more significant difference is observed when comparing the DFT-based results with those obtained from the analytical approach, thus indicating

  3. Evaluation of Little Ice Age cooling in Western Central Andes, suggested by paleoELAs, in contrast with global warming since late 19th century deduced from instrumental records

    NASA Astrophysics Data System (ADS)

    Ubeda, Jose; Palacios, David; Campos, Néstor; Giraldez, Claudia; García, Eduardo; Quiros, Tatiana

    2015-04-01

    This paper attempts to evaluate climate cooling (°C) during the glacial expansion phases using the product GTV•ΔELA, where GTV is the vertical air temperature gradient (°C/m) and ΔELA (m) the difference in level observed between the Equilibrium Line Altitude (ELA) reconstructions for current and past glaciers. With this aim the Area x Altitude Balance Ratio-(AABR) method was used to produce reconstructions of present ELAs (2002-2010) and paleoELAs corresponding to the last glacier advance phase. The reconstructions were produced in three study areas located along a N-S transect of the western cordillera in the Central Andes: the south-western sector of the Nevado Hualcán (9°S, 77°W; Giráldez 2011); the southern slope of the Cordillera Pariaqaqa (12°S, 76°W; Quirós, 2013) and the NW, NE, SE and SW quadrants of the Nevado Coropuna (16°S, 72°W; García 2013; Úbeda 2011; Campos, 2012). The three mountains exceed 6000 m altitude, their summit areas are covered by glaciers, and on their slopes there are existing well-conserved moraines deposited by the last advances near the present front of the ice masses. Although there are no absolute dates to confirm this hypothesis, it has been assumed that the last glacial advances occurred during the Little Ice Age (LIA), which the oxygen isotopes of the Nevado Huascarán (9°S, 77°W) date to the period 1500-1890. For the Hualcán and Pariaqaqa the mean global value of the Earth's GTV (6.5°C/km) was used, considered valid for the Tropics. On the Coropuna a GTV=8.4°C/km was used, based on high resolution sensors installed in situ since 2007 (Úbeda 2011). This gradient is approaching the upper limit of the dry adiabatic gradient (9.8°C/km), as the Coropuna region is more arid than the other case study areas. The climate cooling estimates deduced from the product GTV•ΔELA were compared with the global warming shown by the 1880-2012 series, ΔT=0.85°C, and 1850/1900-2003/2012, ΔT=0.78°C. The differences are

  4. Vegetation density as deduced from ERTS-1 MSS response

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L.; Gausman, H. W.; Cuellar, J. A.; Gerbermann, A. H.; Richardson, A. J.

    1974-01-01

    Reflectance from vegetation increases with increasing vegetation density in the 0.75- to 1.35 micron wavelength interval. Therefore, ERTS-1 bands 6 (0.7 to 0.8 micron) and 7 (0.8 to 1.1 micron) contain information that should relate to the probable yield of crops and the animal carrying capacity of rangeland. The results of an experiment designed specifically to test the relations among leaf area index (LAI), plant population, plant cover and plant height, and the ERTS-1 MSS responses for 3 corn, 10 sorghum, and 10 cotton fields are given. Plant population was as useful as LAI for characterizing the sorghum and corn fields, and plant height was as good as LAI for characterizing cotton fields. These findings generally support the utility of ERTS-1 data for explaining variability in green biomass, harvestable forage and other indicators of productivity.

  5. Climate change deduced from isotopes in tree rings

    SciTech Connect

    Pendall, E.G.; Leavitt, S.W.

    1997-11-01

    This paper describes the theory of carbon, hydrogen, and oxygen isotopic signatures in cellulose for the purpose of paleoclimatic reconstruction. Mechanisms governing tree ring cellulose isotopic variability are investigated, and applications to the southwestern United States are delineated. A monitoring program of pinyon trees and comparison to climatic parameters is briefly described. Variables measured included deviations in hydrogen and oxygen-18 isotopic composition in precipitation, soil water, stem and leaf water, and atmospheric vapor. Water from phloem tissue was found to be isotopically identical to the xylem sap, suggesting that cellulose precursors can exchange isotopically with source water before cellulose is made in the trunk, thus removing most of the isotopic signal from the leaves. Overall results suggest that, on arid sites in the southwestern US receiving adequate summer rain, a precipitation seasonality signal may be recorded. 21 refs., 2 figs.

  6. Properties of the lithosphere and asthenosphere deduced from geoid observations

    NASA Technical Reports Server (NTRS)

    Turcotte, D. L.

    1985-01-01

    Data from the GEOS-3 and SEASAT Satellites provided a very accurate geoid map over the oceans. Broad bathymetric features in the oceans such as oceanic swells and plateaus are fully compensated. It is shown that the geoid anomalies due to the density structures of the lithosphere are proportional to the first moment of the density distribution. The deepening of the ocean basins is attributed to thermal isostasy. The thickness of the oceanic lithosphere increases with age due to the loss of heat to the sea floor. Bathymetry and the geoid provide constraints on the extent of this heat loss. Offsets in the geoid across major fracture zones can also be used to constrain this problem. Geoid bathymetry correlations show that the Hawaiian and Bermuda swells and the Cape Verde Rise are probably due to lithospheric thinning.

  7. Preliminary results on interstellar reddening as deduced from filter photometry

    NASA Technical Reports Server (NTRS)

    Laget, M.

    1972-01-01

    Filter photometry has been used to derive the interstellar reddening law from stars through the study of a single spectral type, B0. The deficiency in the far ultraviolet flux of a supergiant relative to a main sequence star is compared with the difference in the flux distribution due to a change of one spectral class. Individual interstellar reddening curves show the general feature reported by Stecher (1969) and by Bless and Savage (1970). There is a large amount of scatter in the far ultraviolet which may be partially due to a real difference in interstellar extinction and partially due to observational inaccuracy.

  8. Habitat-specific foraging of prothonotary warblers: Deducing habitat quality

    USGS Publications Warehouse

    Lyons, J.E.

    2005-01-01

    Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.

  9. High-latitude irregularity spectra deduced from scintillation measurements

    SciTech Connect

    Wernik, A.W.; Gola, M.; Liu, C.H.; Franke, S.J. Illinois Univ., Urbana )

    1990-10-01

    High-latitude scintillation data show that the strength and spectral index of intensity scintillation are dependent on the propagation geometry. It is shown here that anisotropic irregularity spectra, with different indices along and across the magnetic field, lead to geometrical effects similar to those observed. In general, the spectrum along the magnetic field is steeper than that across the field, and the difference is more pronounced for nighttime conditions. Spectral anisotropy can be interpreted as a size-dependent irregularity anisotropy. It is found that large-scale irregularities in the daytime and nighttime ionosphere are almost isotropic, while small-scale irregularities are anisotropic and considerably more so at night than during the day. It is shown that anisotropic irregularity spectra could account for the observed scintillation and in situ temporal spectra with frequency-dependent slope. 26 refs.

  10. Deducing the symmetry of helical assemblies: Applications to membrane proteins.

    PubMed

    Coudray, Nicolas; Lasala, Ralph; Zhang, Zhening; Clark, Kathy M; Dumont, Mark E; Stokes, David L

    2016-08-01

    Helical reconstruction represents a convenient and powerful approach for structure determination of macromolecules that assemble into helical arrays. In the case of membrane proteins, formation of tubular crystals with helical symmetry represents an attractive alternative, especially when their small size precludes the use of single-particle analysis. An essential first step for helical reconstruction is to characterize the helical symmetry. This process is often daunting, due to the complexity of helical diffraction and to the low signal-to-noise ratio in images of individual assemblies. Furthermore, the large diameters of the tubular crystals produced by membrane proteins exacerbates the innate ambiguities that, if not resolved, will produce incorrect structures. In this report, we describe a set of tools that can be used to eliminate ambiguities and to validate the choice of symmetry. The first approach increases the signal-to-noise ratio along layer lines by incoherently summing data from multiple helical assemblies, thus producing several candidate indexing schemes. The second approach compares the layer lines from images with those from synthetic models built with the various candidate schemes. The third approach uses unit cell dimensions measured from collapsed tubes to distinguish between these candidate schemes. These approaches are illustrated with tubular crystals from a boron transporter from yeast, Bor1p, and a β-barrel channel from the outer membrane of E. coli, OmpF.

  11. Deducing protein function by forensic integrative cell biology.

    PubMed

    Earnshaw, William C

    2013-12-01

    Our ability to sequence genomes has provided us with near-complete lists of the proteins that compose cells, tissues, and organisms, but this is only the beginning of the process to discover the functions of cellular components. In the future, it's going to be crucial to develop computational analyses that can predict the biological functions of uncharacterised proteins. At the same time, we must not forget those fundamental experimental skills needed to confirm the predictions or send the analysts back to the drawing board to devise new ones.

  12. Naturally deducing estimate for the coefficient of CELSS closure.

    PubMed

    Bartsev, S I

    2003-01-01

    The term Closed Ecological System (CES) is in wide use. However there is no generally accepted measure of the closure of ecological systems. In order to obtain reproducibility of experiments with natural and man-made CES (with respect to degree of closure) some universal estimate needs to be developed. Understanding ecological systems as a network and closure as the degree of matter recycling allows the use of matrix graphs. Graphs are very natural forms for the presentation of the network of matter flows in ecosystems. An estimate equal to the sum of products of weights of oriented edges that constitute contour is suggested as a measure of the degree of closure in ecosystems. It is shown that this estimate can be uniformly applied to ecosystems of arbitrary size and configuration of flows.

  13. 350 Year Cloud Reconstruction Deduced from Northeast Caribbean Coral Proxies

    NASA Astrophysics Data System (ADS)

    Winter, A.; Sammarco, P. W.; Mikolajewicz, U.; Jury, M.; Zanchettin, D.

    2014-12-01

    Clouds are a major factor influencing the global climate and its response to external forcing through their implications for the global hydrological cycle, and hence for the planetary radiative budget. Clouds also contribute to regional climates and their variability through, e.g., the changes they induce in regional precipitation patterns. There have been very few studies of decadal and longer-term changes in cloud cover in the tropics and sub-tropics, both over land and the ocean. In the tropics, there is great uncertainty regarding how global warming will affect cloud cover. Observational satellite data are too short to unambiguously discern any temporal trends in cloud cover. Corals generally live in well-mixed coastal regions and can often record environmental conditions of large areas of the upper ocean. This is particularly the case at low latitudes. Scleractinian corals are sessile, epibenthic fauna, and the type of environmental information recorded at the location where the coral has been living is dependent upon the species of coral considered and proxy index of interest. Skeletons of scleractinian corals are considered to provide among the best records of high-resolution (sub-annual) environmental variability in the tropical and sub-tropical oceans. Zooxanthellate hermatypic corals in tropical and sub-tropical seas precipitate CaCO3 skeletons as they grow. This growth is made possible through the manufacture of CaCO3crystals, facilitated by the zooxanthellae. During the process of crystallization, the holobiont binds carbon of different isotopes into the crystals. Stable carbon isotope concentrations vary with a variety of environmental conditions. In the Caribbean, d13C in corals of the species Montastraea faveolata can be used as a proxy for changes in cloud cover. In this contribution, we will demonstrate that the stable isotope 13C varies concomitantly with cloud cover for the northeastern Caribbean region. Using this proxy we have been able to reconstruct cloud cover conditions back to the year 1760 and thus determine historical cloud cover prior to the recent use of instrumental records. We will also discuss how our coral proxy record of cloud cover compares to paleo-climate model runs for the same time period.

  14. Deducing the multi-trader population driving a financial market

    NASA Astrophysics Data System (ADS)

    Gupta, Nachi; Hauser, Raphael; Johnson, Neil

    2005-12-01

    We have previously laid out a basic framework for predicting financial movements and pockets of predictability by tracking the distribution of a multi-trader population playing on an artificial financial market model. This work explores extensions to this basic framework. We allow for more intelligent agents with a richer strategy set, and we no longer constrain the distribution over these agents to a probability space. We then introduce a fusion scheme which accounts for multiple runs of randomly chosen sets of possible agent types. We also discuss a mechanism for bias removal on the estimates.

  15. Asteroidal Differentiation Processes Deduced from Ultramafic Achondrite Ureilite Meteorites

    NASA Technical Reports Server (NTRS)

    Downes, Hilary; Mittlefehldt, David W.; Hudson, Pierre; Romanek, Christopher S.; Franchi, Ian

    2006-01-01

    Ureilites are the second largest achondrite group. They are ultramafic achondrites that have experienced igneous processing whilst retaining some degree of nebula-derived chemical heterogeneity. They differ from other achondrites in that they contain abundant carbon and their oxygen isotope compositions are very heterogeneous and similar to those of the carbonaceous chondrite anhydrous mineral line. Their carbonaceous nature and some compositional characteristics indicative of nebular origin suggest that they are primitive materials that form a link between nebular processes and early periods of planetesimal accretion. However, despite numerous studies, the exact origin of ureilites remains unclear. Current opinion is that they represent the residual mantle of an asteroid that underwent silicate and Fe-Ni-S partial melting and melt removal. Recent studies of short-lived chronometers indicate that the parent asteroid of the ureilites differentiated very early in the history of the Solar System. Therefore, they contain important information about processes that formed small rocky planetesimals in the early Solar System. In effect, they form a bridge between nebula processes and differentiation in small planetesimals prior to accretion into larger planets and so a correct interpretation of ureilite petrogenesis is essential for understanding this critical step.

  16. Magmatic Processes and Systems Deduced from Single Crystals

    NASA Astrophysics Data System (ADS)

    Davidson, J.; Bezard, R. C.; Morgan, D. J.; Ginibre, C.

    2014-12-01

    When crystals grow in liquids the composition of their outermost layer will reflect that of the host with which they are in equilibrium and will therefore record the liquid composition, pressure and temperature.. Following separation from their sources, magmas differentiate. This change in liquid composition is driven largely by crystallisation in response to cooling or decompression. Other open system processes such as mixing and contamination are common. These can lead to abrupt changes in trace element and isotopic composition, accompanied by petrographic features, such as dissolution surfaces or zones of melt inclusions. Where such careful mineral-scale studies have been performed, the prevalence of open system processes is clear. In many cases these are shown by core-rim isotopic variations. Crystal-scale compositional variations in the context of whole rock compositions and petrography have allowed us to show crustal assimilation even from regions of supposedly oceanic crust such as the Lesser Antilles. In tandem with tracking magma evolution, core-rim analyses of appropriate crystals have also provided diffusion profiles which reflect timescales of magmatic processes. A key point, long recognised by Bruce Marsh, is that in situ geochemical data should be considered in a petrographic context in order to gain the most (and most credible) insights on the workings of magma systems from hand specimen to whole volcano/pluton scales: The petrographic microscope is not dead yet Identification of magmatic processes from in situ scrutiny allows us to synthesise the architectures and inner workings of magma systems. The evidence for interaction among magmas in many systems is compelling and suggests that many exist as stacked dike-sill arrangements with wall-rock focussed crystal growth and mush zones. These are consistent with many of the systematics suggested some time ago by Bruce Marsh

  17. Hazard estimation deduced from GPS and seismic data of Egypt

    NASA Astrophysics Data System (ADS)

    Sayed Mohamed, Abdel-Monem

    Egypt rapidly growing development is accompanied by increasing levels of standard living particular in its urban areas. However, there is a limited experience in quantifying the sources of risk management in Egypt and in designing efficient strategies to keep away serious impacts of earthquakes. From the historical point of view and recent instrumental records, there are some seismo-active regions in Egypt, where some significant earthquakes had occurred in different places. The special tectonic features in Egypt: Aswan, Greater Cairo, Red Sea and Sinai Peninsula regions are the territories of a high seismic risk, which have to be monitored by up-to date technologies. The investigations of the seismic events and interpretations led to evaluate the seismic hazard for disaster prevention and for the safety of the dense populated regions and the vital national projects as the High Dam. In addition to the monitoring of the recent crustal movements, the most powerful technique of satellite geodesy GPS are used where geodetic networks are covering such seismo-active regions. The results from the data sets are compared and combined in order to determine the main characteristics of the deformation and hazard estimation for specified regions. The final compiled output from the seismological and geodetic analysis threw lights upon the geodynamical regime of these seismo-active regions and put Aswan and Greater Cairo under the lowest class according to horizontal crustal strains classifications. This work will serve a basis for the development of so-called catastrophic models and can be further used for catastrophic risk management. Also, this work is trying to evaluate risk of large catastrophic losses within the important regions including the High Dam, strategic buildings and archeological sites. Studies on possible scenarios of earthquakes and losses are a critical issue for decision making in insurance as a part of mitigation measures.

  18. Deducing the age of the dense Venus atmosphere

    NASA Technical Reports Server (NTRS)

    Kahn, R.

    1982-01-01

    It is shown how crater size-density counts may be used to help constrain the history of the Venus atmosphere, based on the predictions of simple but reasonable models for crater production, surface erosion, and the effects of atmospheric drag and breakup on incident meteors in the Venus atmosphere. In particular, if the atmosphere is young, the old (uneroded) surfaces will have crater densities upward of 0.0001/sq km and a ratio of small (4 km) craters to large (128 km) craters near 1000. If the atmosphere is old and the breakup mechanism is dominant, absolute crater densities on Venus surfaces will be diminished by several orders of magnitude relative to the young atmosphere case. If atmospheric drag is dominant, the absolute crater density will be lowered by perhaps an order of magnitude relative to the young atmosphere case, and the ratio of small to large craters will be reduced to a value near 10 to the 1.5 power. Once a large fraction of Venus surface has been imaged at kilometer resolution, as the VOIR project promises to do, it could be possible to make an early determination of the age of the Venus atmosphere.

  19. Deducing the age of the dense Venus atmosphere

    NASA Technical Reports Server (NTRS)

    Kahn, R.

    1989-01-01

    It is shown how crater size-density counts may be used to help constrain the history of the Venus atmosphere, based on the predictions of simple but reasonable models for crater production, surface erosion, and the effects of atmospheric drag and breakup on incident meteors in the Venus atmosphere. In particular, if the atmosphere is young, the old (uneroded) surfaces will have crater densities upward of 0.0001/sq km and a ratio of small (4 km) craters to large (128 km) craters near 1000. If the atmosphere is old and the breakup mechanism is dominant, absolute crater densities on Venus surfaces will be diminished by several orders of magnitude relative to the young atmosphere case. If atmospheric drag is dominant, the absolute crater density will be lowered by perhaps an order of magnitude relative to the young atmosphere case, and the ratio of small to large craters will be reduced to a value near 10 to the 1.5 power. Once a large fraction of Venus surface has been imaged at kilometer resolution, as the Venus Orbiting Imaging Radar project promises to do, it could be possible to make an early determination of the age of the Venus atmosphere.

  20. Physical properties of conventional explosives deduced from radio frequency emissions

    SciTech Connect

    Harlin, Jeremiah D; Nemzek, Robert

    2008-01-01

    Los Alamos National Laboratory collected broadband radio frequency (RF) electric field change measurements from multiple detonations of high explosives (HE). Three types of HE were used: small cylinders of flake TNT, solid TNT, and PBX-9501. Low frequency signals (<80 MHz) were shot-to-shot repeatable and occurred within the first 100 {mu} s at measured amplitudes of about 2 V m{sup -1} at 35 m distance. High frequency signals (>290 MHz) occurred later, were an order of magnitude lower in signal strength, and were not repeatable. There is a positive correlation between the maximum electric field change and the shock velocity of the HE. The amount of free charge produced in the explosion estimated from the first RF pulse is between 10 and 150 {mu} C. This implies a weakly ionized plasma with temperatures between 2600 and 2900 K.

  1. Deducing Electron Properties from Hard X-Ray Observations

    NASA Technical Reports Server (NTRS)

    Kontar, E. P.; Brown, J. C.; Emslie, A. G.; Hajdas, W.; Holman, G. D.; Hurford, G. J.; Kasparova, J.; Mallik, P. C. V.; Massone, A. M.; McConnell, M. L.; Piana, M.; Prato, M.; Schmahl, E. J.; Suarez-Garcia, E.

    2011-01-01

    X-radiation from energetic electrons is the prime diagnostic of flare-accelerated electrons. The observed X-ray flux (and polarization state) is fundamentally a convolution of the cross-section for the hard X-ray emission process(es) in question with the electron distribution function, which is in turn a function of energy, direction, spatial location and time. To address the problems of particle propagation and acceleration one needs to infer as much information as possible on this electron distribution function, through a deconvolution of this fundamental relationship. This review presents recent progress toward this goal using spectroscopic, imaging and polarization measurements, primarily from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Previous conclusions regarding the energy, angular (pitch angle) and spatial distributions of energetic electrons in solar flares are critically reviewed. We discuss the role and the observational evidence of several radiation processes: free-free electron-ion, free-free electron-electron, free-bound electron-ion, photoelectric absorption and Compton backscatter (albedo), using both spectroscopic and imaging techniques. This unprecedented quality of data allows for the first time inference of the angular distributions of the X-ray-emitting electrons and improved model-independent inference of electron energy spectra and emission measures of thermal plasma. Moreover, imaging spectroscopy has revealed hitherto unknown details of solar flare morphology and detailed spectroscopy of coronal, footpoint and extended sources in flaring regions. Additional attempts to measure hard X-ray polarization were not sufficient to put constraints on the degree of anisotropy of electrons, but point to the importance of obtaining good quality polarization data in the future.

  2. Deducing Electron Properties from Hard X-ray Observations

    NASA Astrophysics Data System (ADS)

    Kontar, E. P.; Brown, J. C.; Emslie, A. G.; Hajdas, W.; Holman, G. D.; Hurford, G. J.; Kašparová, J.; Mallik, P. C. V.; Massone, A. M.; McConnell, M. L.; Piana, M.; Prato, M.; Schmahl, E. J.; Suarez-Garcia, E.

    2011-09-01

    X-radiation from energetic electrons is the prime diagnostic of flare-accelerated electrons. The observed X-ray flux (and polarization state) is fundamentally a convolution of the cross-section for the hard X-ray emission process(es) in question with the electron distribution function, which is in turn a function of energy, direction, spatial location and time. To address the problems of particle propagation and acceleration one needs to infer as much information as possible on this electron distribution function, through a deconvolution of this fundamental relationship. This review presents recent progress toward this goal using spectroscopic, imaging and polarization measurements, primarily from the Reuven Ramaty High Energy Solar Spectroscopic Imager ( RHESSI). Previous conclusions regarding the energy, angular (pitch angle) and spatial distributions of energetic electrons in solar flares are critically reviewed. We discuss the role and the observational evidence of several radiation processes: free-free electron-ion, free-free electron-electron, free-bound electron-ion, photoelectric absorption and Compton backscatter (albedo), using both spectroscopic and imaging techniques. This unprecedented quality of data allows for the first time inference of the angular distributions of the X-ray-emitting electrons and improved model-independent inference of electron energy spectra and emission measures of thermal plasma. Moreover, imaging spectroscopy has revealed hitherto unknown details of solar flare morphology and detailed spectroscopy of coronal, footpoint and extended sources in flaring regions. Additional attempts to measure hard X-ray polarization were not sufficient to put constraints on the degree of anisotropy of electrons, but point to the importance of obtaining good quality polarization data in the future.

  3. Deducing chemical structure from crystallographically determined atomic coordinates

    PubMed Central

    Bruno, Ian J.; Shields, Gregory P.; Taylor, Robin

    2011-01-01

    An improved algorithm has been developed for assigning chemical structures to incoming entries to the Cambridge Structural Database, using only the information available in the deposited CIF. Steps in the algorithm include detection of bonds, selection of polymer unit, resolution of disorder, and assignment of bond types and formal charges. The chief difficulty is posed by the large number of metallo-organic crystal structures that must be processed, given our aspiration that assigned chemical structures should accurately reflect properties such as the oxidation states of metals and redox-active ligands, metal coordination numbers and hapticities, and the aromaticity or otherwise of metal ligands. Other complications arise from disorder, especially when it is symmetry imposed or modelled with the SQUEEZE algorithm. Each assigned structure is accompanied by an estimate of reliability and, where necessary, diagnostic information indicating probable points of error. Although the algorithm was written to aid building of the Cambridge Structural Database, it has the potential to develop into a general-purpose tool for adding chemical information to newly determined crystal structures. PMID:21775812

  4. Deducing effective light transport parameters in optically thin systems

    NASA Astrophysics Data System (ADS)

    Mazzamuto, G.; Pattelli, L.; Toninelli, C.; Wiersma, D. S.

    2016-02-01

    We present an extensive Monte Carlo study on light transport in optically thin slabs, addressing both axial and transverse propagation. We systematically characterize diffusive transport in this intermediate scattering regime, notably in terms of the spatial variance of the transmitted/reflected profile. Focusing on late, multiply scattered light, we test the validity of the prediction cast by diffusion theory that the spatial variance should grow independently of absorption and, to a first approximation, of the sample thickness and refractive index contrast. Based on a large set of simulated data, we build a freely available look-up table routine enabling reliable and precise determination of the microscopic transport parameters starting from robust observables which are independent from absolute intensity measurements. We also present the Monte Carlo software package that was developed for the purpose of this study.

  5. Debris and meteoroid proportions deduced from impact crater residue analysis

    NASA Technical Reports Server (NTRS)

    Berthoud, Lucinda; Mandeville, Jean-Claude; Durin, Christian; Borg, Janet

    1995-01-01

    This study is a further investigation of space-exposed samples recovered from the LDEF satellite and the Franco-Russian 'Aragatz' dust collection experiment on the Mir Space Station. Impact craters with diameters ranging from 1 to 900 micron were found on the retrieved samples. Elemental analysis of residues found in the impact craters was carried out using Energy Dispersive X-ray spectrometry (EDX). The analyses show evidence of micrometeoroid and orbital debris origins for the impacts. The proportions of these two components vary according to particle size and experimental position with respect to the leading edge of the spacecraft. On the LDEF leading edge 17 percent of the impacts were apparently caused by micrometeoroids and 11 percent by debris; on the LDEF trailing edge 23 percent of the impacts are apparently caused by micrometeoroids and 4 percent consist of debris particles - mostly larger than 3 micron in diameter - in elliptical orbits around the Earth. For Mir, the analyses indicate that micrometeoroids form 23 percent of impacts and debris 9 percent. However, we note that 60-70 percent of the craters are unidentifiable, so the definitive proportions of natural v. man-made particles are yet to be determined. Experiments carried out using a light gas gun to accelerate glass spheres and fragments demonstrate the influence of particle shape on crater morphology. The experiments also show that it is more difficult to analyze the residues produced by an irregular fragment than those produced by a spherical projectile. If the particle is travelling above a certain velocity, it vaporizes upon impact and no residues are left. Simulation experiments carried out with an electrostatic accelerator indicate that this limit is about 14 km/s for Fe particles impacting Al targets. This chemical analysis cut-off may bias interpretations of the relative populations of meteoroid and orbital debris. Oblique impacts and multiple foil detectors provide a higher likelihood of detection of residues as the velocities involved are lower.

  6. Deducing the symmetry of helical assemblies: Applications to membrane proteins.

    PubMed

    Coudray, Nicolas; Lasala, Ralph; Zhang, Zhening; Clark, Kathy M; Dumont, Mark E; Stokes, David L

    2016-08-01

    Helical reconstruction represents a convenient and powerful approach for structure determination of macromolecules that assemble into helical arrays. In the case of membrane proteins, formation of tubular crystals with helical symmetry represents an attractive alternative, especially when their small size precludes the use of single-particle analysis. An essential first step for helical reconstruction is to characterize the helical symmetry. This process is often daunting, due to the complexity of helical diffraction and to the low signal-to-noise ratio in images of individual assemblies. Furthermore, the large diameters of the tubular crystals produced by membrane proteins exacerbates the innate ambiguities that, if not resolved, will produce incorrect structures. In this report, we describe a set of tools that can be used to eliminate ambiguities and to validate the choice of symmetry. The first approach increases the signal-to-noise ratio along layer lines by incoherently summing data from multiple helical assemblies, thus producing several candidate indexing schemes. The second approach compares the layer lines from images with those from synthetic models built with the various candidate schemes. The third approach uses unit cell dimensions measured from collapsed tubes to distinguish between these candidate schemes. These approaches are illustrated with tubular crystals from a boron transporter from yeast, Bor1p, and a β-barrel channel from the outer membrane of E. coli, OmpF. PMID:27255388

  7. Transport of trace species deduced from LIMS observations

    NASA Technical Reports Server (NTRS)

    Gille, J. C.; Lyjak, L. V.; Smith, A. K.; Bailey, P. L.; Massie, S. T.; Smythe, C. M.

    1985-01-01

    One of the critical problems in the middle atmosphere at this time is understanding the interaction between atmospheric motions and photochemistry, and the way in which these two processes maintain the distributions of photochemically active species such as ozone. Recent work has shown that a great deal can be learned by considering the zonally averaged distributions and transports, i.e., working in the latitude-altitude plane. This 2-dimensional approach has been used in the past in Eulerian formation. Recent work (DUNKERTON, 1978) has shown that formulating the transport problems in terms of the residual mean circulation, which has similarity to the Lagrangian mean motion, results in a more physical picture of the way in which the transport takes place. Here, data from the Limb Infrared Monitor of the Stratosphere (LIMB) experiment are used to investigate how well the residual mean formulation works with real data, in the sense of asking how well the predicted ozone changes match those in regions of the lower stratosphere in which chemical changes may be neglected. This allows a test of the approximations that are made, and of the strengths and weaknesses of this approach to transport calculation.

  8. A Single 30-s Stretch Is Sufficient to Inhibit Maximal Voluntary Strength

    ERIC Educational Resources Information Center

    Winchester, Jason B.; Nelson, Arnold G.; Kokkonen, Joke

    2009-01-01

    While it has been well established that an acute stretching program can inhibit maximal muscle performance, the amount of stretching needed to produce the deleterious response is unknown. Therefore this study examined the dose-response relationship between acute stretching and strength inhibition. Eighteen college students performed a one…

  9. (1S,5R,7R,30S)-14-De­oxy­isogarcinol

    PubMed Central

    Kaur, Ranjeet; Vasudev, Prema G.; Chattopadhyay, Sunil K.

    2012-01-01

    The title compound, C38H50O5 {systematic name: 10-(3-hy­droxy­benzo­yl)-2,2,7,7-tetra­methyl-3,6,8-tris­(3-methyl­but-2-en­yl)-3,4,4a,5,6,7-hexa­hydro-4a,8-methano-2H-cyclo­octa­[b]pyran-9,11(8H)-dione}, is a polyisoprenylated benzophenone, isolated for the first time from the fruits of Garcinia indica during our investigation of bioactive compounds from this plant and their large-scale extraction. The relative configuration of the title compound was chosen based on comparison of its spectroscopic and optical rotation data with that of the isomorphous and isostructural compound isogarcinol, whose absolute configuration is known. The crystal packing features O—H⋯O hydrogen bonds. A Cambridge Structural Database analysis revealed that the crystal structure reported here is isomorphous and isostructural with that of isogarcinol. PMID:22719626

  10. Protein-RNA Dynamics in the Central Junction Control 30S Ribosome Assembly.

    PubMed

    Baker, Kris Ann; Lamichhane, Rajan; Lamichhane, Tek; Rueda, David; Cunningham, Philip R

    2016-09-11

    Interactions between ribosomal proteins (rproteins) and ribosomal RNA (rRNA) facilitate the formation of functional ribosomes. S15 is a central domain primary binding protein that has been shown to trigger a cascade of conformational changes in 16S rRNA, forming the functional structure of the central domain. Previous biochemical and structural studies in vitro have revealed that S15 binds a three-way junction of helices 20, 21, and 22, including nucleotides 652-654 and 752-754. All junction nucleotides except 653 are highly conserved among the Bacteria. To identify functionally important motifs within the junction, we subjected nucleotides 652-654 and 752-754 to saturation mutagenesis and selected and analyzed functional mutants. Only 64 mutants with greater than 10% ribosome function in vivo were isolated. S15 overexpression complemented mutations in the junction loop in each of the partially active mutants, although mutations that produced inactive ribosomes were not complemented by overexpression of S15. Single-molecule Förster or fluorescence resonance energy transfer (smFRET) was used to study the Mg(2+)- and S15-induced conformational dynamics of selected junction mutants. Comparison of the structural dynamics of these mutants with the wild type in the presence and absence of S15 revealed specific sequence and structural motifs in the central junction that are important in ribosome function. PMID:27192112

  11. Analysis of r-protein and RNA conformation of 30S subunit intermediates in bacteria

    PubMed Central

    Napper, Nathan; Culver, Gloria M.

    2015-01-01

    The ribosome is a large macromolecular complex that must be assembled efficiently and accurately for the viability of all organisms. In bacteria, this process must be robust and tunable to support life in diverse conditions from the ice of arctic glaciers to thermal hot springs. Assembly of the Small ribosomal SUbunit (SSU) of Escherichia coli has been extensively studied and is highly temperature-dependent. However, a lack of data on SSU assembly for other bacteria is problematic given the importance of the ribosome in bacterial physiology. To broaden the understanding of how optimal growth temperature may affect SSU assembly, in vitro SSU assembly of two thermophilic bacteria, Geobacillus kaustophilus and Thermus thermophilus, was compared with that of E. coli. Using these phylogenetically, morphologically, and environmentally diverse bacteria, we show that SSU assembly is highly temperature-dependent and efficient SSU assembly occurs at different temperatures for each organism. Surprisingly, the assembly landscape is characterized by at least two distinct intermediate populations in the organisms tested. This novel, second intermediate, is formed in the presence of the full complement of r-proteins, unlike the previously observed RI* particle formed in the absence of late-binding r-proteins in E. coli. This work reveals multiple distinct intermediate populations are present during SSU assembly in vitro for several bacteria, yielding insights into RNP formation and possible antimicrobial development toward this common SSU target. PMID:25999315

  12. SuhB Associates with Nus Factors To Facilitate 30S Ribosome Biogenesis in Escherichia coli

    PubMed Central

    Singh, Navjot; Bubunenko, Mikhail; Smith, Carol; Abbott, David M.; Stringer, Anne M.; Shi, Ronald; Court, Donald L.

    2016-01-01

    ABSTRACT A complex of highly conserved proteins consisting of NusB, NusE, NusA, and NusG is required for robust expression of rRNA in Escherichia coli. This complex is proposed to prevent Rho-dependent transcription termination by a process known as “antitermination.” The mechanism of this antitermination in rRNA is poorly understood but requires association of NusB and NusE with a specific RNA sequence in rRNA known as BoxA. Here, we identify a novel member of the rRNA antitermination machinery: the inositol monophosphatase SuhB. We show that SuhB associates with elongating RNA polymerase (RNAP) at rRNA in a NusB-dependent manner. Although we show that SuhB is required for BoxA-mediated antitermination in a reporter system, our data indicate that the major function of the NusB/E/A/G/SuhB complex is not to prevent Rho-dependent termination of rRNA but rather to promote correct rRNA maturation. This occurs through formation of a SuhB-mediated loop between NusB/E/BoxA and RNAP/NusA/G. Thus, we have reassigned the function of these proteins at rRNA and identified another key player in this complex. PMID:26980831

  13. "The Little Red Hen," Soap Sculpture, and Analyzing Magazines: Character Education in the 1920s and '30s.

    ERIC Educational Resources Information Center

    Field, Sherry L.; Nickell, Pat

    2000-01-01

    Archival research on character education in the 1920s and 1930s in Washington, DC; Denver, Colorado; Birmingham, Alabama; and Pennsylvania, Iowa, and New York reveals that character education was an accepted goal of public schooling. Learning activities were designed to teach specific character traits. (SK)

  14. Studies of the structure of the Tz = -1 Nuclei 20Na and 30S for explosive astrophysics

    NASA Astrophysics Data System (ADS)

    Wallace, Jennifer Patrita

    Two and three-dimensional seismic data are used to investigate some stratigraphic relationships between sedimentation, deformation and fluid flow at the lateral margin of a gravity detachment system. Three themes were studied. In the Niger Delta, a right-lateral strike-slip fault with a displacement of around 7 km occurs across 75 km. It is interpreted as the lateral strike-slip domain, linked to the updip extensional domain and the downdip compression zone of a gravity detachment system. Structural and kinematic evidence, such as present-day propagating strike-slip faults, for possible future lateral expansions of the lateral strike-slip domain, is described. We expect to observe similar domains at the margins of other preserved gravitational collapse sliding over a detachment whose efficiency in causing downdip slip may vary laterally. Using 3D data from both Mauritania and Nigeria, the interactions between tear faults and deepwater channels are studied. Structural observations combined with channel analysis are performed in four case studies, illustrating that tear faults influence channel development throughout their evolution. Some examples across tear fault zones are presented, and it is expected to find such interactions elsewhere in the world. A simple model of development of vertical fluid flow pipes is established using two examples that are 400 - 600 m wide and ~ 2000 - 2500 m high. Both examples are located at the crest of rollover anticlines and rooted in buried channel-complexes tilted during fold growth. At the crest of the structures and within the connected permeable reservoir intervals of the channel complexes, lateral pressure transfer caused the pore pressure to reach critical levels, leading to hydraulic fracturing of the overburden. Although hydrocarbons may migrate upwards through the consequent chimney systems, the pipes are not necessarily indicators of hydrocarbon charge of the channel complexes.

  15. Metabolic response in type I and type II muscle fibers during a 30-s cycle sprint in men and women.

    PubMed

    Esbjörnsson-Liljedahl, M; Sundberg, C J; Norman, B; Jansson, E

    1999-10-01

    The acute metabolic response to sprint exercise was studied in 20 male and 19 female students. We hypothesized that the reduction of muscle glycogen content during sprint exercise would be smaller in women than in men and that a possible gender difference in glycogen reduction would be higher in type II than in type I fibers. The exercise-induced increase in blood lactate concentration was 22% smaller in women than in men. A considerable reduction of ATP (50%), phosphocreatine (83%), and glycogen (35%) was found in type II muscle fibers, and it did not differ between the genders. A smaller reduction of ATP (17%) and phosphocreatine (78%) was found in type I fibers, and it did not differ between the genders. However, the exercise-induced reduction in glycogen content in type I fibers was 50% smaller in women than in men. The hypothesis was indeed partly confirmed: the exercise-induced glycogen reduction was attenuated in women compared with men, but the gender difference was in type I rather than in type II fibers. Fiber-type-specific and gender-related differences in the metabolic response to sprint exercise might have implications for the design of training programs for men and women.

  16. Tectonic and unroofing history of Neogene Manantiales foreland basin deposits, Cordillera Frontal (32°30'S), San Juan Province, Argentina

    NASA Astrophysics Data System (ADS)

    Pérez, Daniel J.

    2001-12-01

    The Miocene Manantiales foreland basin is located in Cordillera Frontal of San Juan, between 32°30' and 33°S. The unroofing study of the synorogenic Miocene deposits provides information about the structural evolution of Cordón de La Ramada fold-and-thrust belt. These Tertiary deposits are represented by the Chinches Formation and comprise seven members (Tc0-Tc6). They are the result of the uplift of Mesozoic sequences that crop out in La Ramada fold-and-thrust belt of the Cordillera Principal. Quaternary deposits unconformably overlying the Chinches Formation are composed of granitic and rhyolitic blocks, and represent the final uplift of the Cordón del Espinacito and a series of out-of-sequence thrusts. The unroofing studies also provide sufficient information to establish the out-of-sequence timing of the deformation at this latitude. Initial deposition of the Tertiary deposits can be dated at about 20 Ma, or early Miocene. Andesitic lavas dated in 9.2±0.3, 10.7±0.7, and 12.7±0.7 Ma unconformably overlie the structure of La Ramada fold-and-thrust belt. These facts constrain the uplift of the High Andes between 20 and 10 Ma at this latitude. The unconformity between Tertiary and Quaternary deposits suggests final uplift during Pliocene-Pleistocene times.

  17. Lower plate deformation at the Chile Triple Junction from the paleomagnetic record (45°30'S-46°S)

    NASA Astrophysics Data System (ADS)

    Lagabrielle, Yves; Bourgois, Jacques; Dyment, Jerôme; Pelletier, Bernard

    2015-08-01

    During the Chile Triple Junction (CTJ) cruise, geophysical surveys were conducted between 45°S and 48°S, in the region of the Chile Triple Junction (CTJ), where the Nazca and Antarctica Plates are subducting beneath the South American Plate. Near the CTJ, the South Chile Rise (SCR), which separates the Nazca and Antarctica lower plates, consists of three spreading segments trending ~N160°, separated by a series of parallel fracture zones. The active spreading centers of the three segments consist of grabens with various widths and depths, bounded by steep fault scarps. We provide robust data showing that the SCR recorded remote and long-term effects of ridge subduction far from the subduction front. Magnetic profiles, multibeam bathymetric, and seismic data were acquired at intervals of 13 km along a N80°E direction across the SCR during the CTJ cruise of R/V L'Atalante. Deformation of the oceanic lithosphere includes (1) a segmentation of the spreading axes along strike, (2) some ridge jumps, and (3) local constriction and changes in trend of the fracture zone valleys. Off-axis volcanism is observed in places that may suggest a link with an abnormal stress field induced by ridge subduction. The tectonic and volcanic anomalies, which occurred in response to the subduction of the SCR1 axis, may be correlated with geochemical anomalies and slab fragmentation recognized by previous works.

  18. Pu236(n,f) , Pu237(n,f) , and Pu238(n,f) cross sections deduced from (p,t) , (p,d) , and (p,p') surrogate reactions

    SciTech Connect

    Hughes, R. O.; Beausang, C. W.; Ross, T. J.; Burke, J. T.; Casperson, R. J.; Cooper, N.; Escher, J. E.; Gell, K.; Good, E.; Humby, P.; McCleskey, M.; Saastimoinen, A.; Tarlow, T. D.; Thompson, I. J.

    2014-07-01

    The Pu236(n,f), Pu237(n,f) and Pu238(n,f) cross sections have been inferred by utilizing the surrogate ratio method. Targets of Pu239 and U235 were bombarded with 28.5-MeV protons, and the light ion recoils, as well as fission fragments, were detected using the STARS detector array at the K150 Cyclotron at the Texas A&M cyclotron facility. The (p, tf) reaction on Pu239 and U235 targets was used to deduce the σ (Pu236(n,f))/σ(U232(n,f)) ratio, and the Pu236(n,f) cross section was subsequently determined for En=0.5–7.5 MeV. Similarly, the (p,df) reaction on the same two targets was used to deduce the σ(Pu237(n,f))/σ(U233(n,f)) ratio, and the Pu237(n,f) cross section was extracted in the energy range En=0.5–7 MeV. The Pu238(n,f) cross section was also deduced by utilizing the (p,p') reaction channel on the same targets. There is good agreement with the recent ENDF/B-VII.1 evaluated cross section data for Pu238(n,f) in the range En=0.5–10.5 MeV and for Pu237(n,f) in the range En=0.5–7 MeV; however, the Pu236(n,f) cross section deduced in the present work is higher than the evaluation between 2 and 7 MeV.

  19. Petroleum potentialities of central Tunisia as deduced from identification and characterization of oil source rocks

    SciTech Connect

    Saidi, M.; Acheche, M.H.; Inoubli, H. ); Belayouni, H. )

    1991-08-01

    Many potential oil source rocks occur within the Tunisian stratigraphic column, including Silurian-Devonian shales, Albian and upper Albian-Vraconian carbonates, Cenomanian-Turonian black shales and lower Eocene carbonates. This focuses on the inventory of potential oil source rocks in central Tunisia ranging from middle Jurassic to Turonian. The emphasis is on determining their genetic potential and whether they could have generated oil and gas. Geochemical data obtained from the analysis of at least 2,147 samples show this region to be of significant interest as a petroleum prospective area. The main source rocks identified are Toarcian shales, upper Albian-Vraconian carbonates and Cenomanian-Turonian black shales. They contain predominantly type 2 organic matter (oil and gas prone) and are at the low maturity limit of the oil window. The occurrence of those source rocks close to numerous potential reservoir facies supports the conclusion that central Tunisia is a very interesting area for petroleum exploration.

  20. Evolution of green plants as deduced from 5S rRNA sequences.

    PubMed

    Hori, H; Lim, B L; Osawa, S

    1985-02-01

    We have constructed a phylogenic tree for green plants by comparing 5S rRNA sequences. The tree suggests that the emergence of most of the uni- and multicellular green algae such as Chlamydomonas, Spirogyra, Ulva, and Chlorella occurred in the early stage of green plant evolution. The branching point of Nitella is a little earlier than that of land plants and much later than that of the above green algae, supporting the view that Nitella-like green algae may be the direct precursor to land plants. The Bryophyta and the Pteridophyta separated from each other after emergence of the Spermatophyta. The result is consistent with the view that the Bryophyta evolved from ferns by degeneration. In the Pteridophyta, Psilotum (whisk fern) separated first, and a little later Lycopodium (club moss) separated from the ancestor common to Equisetum (horsetail) and Dryopteris (fern). This order is in accordance with the classical view. During the Spermatophyta evolution, the gymnosperms (Cycas, Ginkgo, and Metasequoia have been studied here) and the angiosperms (flowering plants) separated, and this was followed by the separation of Metasequoia and Cycas (cycad)/Ginkgo (maidenhair tree) on one branch and various flowering plants on the other.

  1. Evolution of green plants as deduced from 5S rRNA sequences

    PubMed Central

    Hori, Hiroshi; Lim, Byung-Lak; Osawa, Syozo

    1985-01-01

    We have constructed a phylogenic tree for green plants by comparing 5S rRNA sequences. The tree suggests that the emergence of most of the uni- and multicellular green algae such as Chlamydomonas, Spirogyra, Ulva, and Chlorella occurred in the early stage of green plant evolution. The branching point of Nitella is a little earlier than that of land plants and much later than that of the above green algae, supporting the view that Nitella-like green algae may be the direct precursor to land plants. The Bryophyta and the Pteridophyta separated from each other after emergence of the Spermatophyta. The result is consistent with the view that the Bryophyta evolved from ferns by degeneration. In the Pteridophyta, Psilotum (whisk fern) separated first, and a little later Lycopodium (club moss) separated from the ancestor common to Equisetum (horsetail) and Dryopteris (fern). This order is in accordance with the classical view. During the Spermatophyta evolution, the gymnosperms (Cycas, Ginkgo, and Metasequoia have been studied here) and the angiosperms (flowering plants) separated, and this was followed by the separation of Metasequoia and Cycas (cycad)/Ginkgo (maidenhair tree) on one branch and various flowering plants on the other. PMID:16593540

  2. Features of highly structured equatorial plasma irregularities deduced from CHAMP observations

    NASA Astrophysics Data System (ADS)

    Xiong, C.; Lühr, H.; Ma, S. Y.; Stolle, C.; Fejer, B. G.

    2012-08-01

    In this study five years of CHAMP (Challenging Mini-satellite Payload) fluxgate magnetometer (FGM) data is used to investigate the characteristics of Equatorial Plasma Bubbles (EPBs). We filtered the FGM data by using band-passes with four different cut-off periods to get the EPBs with different maximum spatial scale sizes in the meridional plane ranging from 76-608 km. Associated with the EPB observations at about 400 km, the typical altitude of CHAMP during the year 2000-2005, we also investigate the post-sunset equatorial vertical plasma drift data from ROCSAT-1 (Republic of China Satellite 1). Since the height of the F-layer is highly correlated with the vertical plasma drift and solar flux, we sorted the ROCSAT-1 data into different groups by F10.7. From the integrated vertical drift we have estimated the post-sunset uplift of the ionosphere. By comparing the properties of EPB occurrence for different scale sizes with the global distribution of plasma vertical uplift, we have found that EPBs reaching higher altitudes are more structured than those which are sampled by CHAMP near the top side of the depleted fluxtube. Such a result is in accord with 3-D model simulations (Aveiro and Hysell, 2010). Small-scale EPB structures are observed by CHAMP when the irregularities reach apex heights of 800 km and more. Such events are encountered primarily in the Brazilian sector during the months around November, when the post-sunset vertical plasma drift is high.

  3. Fishing for biodiversity: novel methanopterin-linked C transfer genes deduced from the Sargasso Sea metagenome.

    PubMed

    Kalyuzhnaya, Marina G; Nercessian, Olivier; Lapidus, Alla; Chistoserdova, Ludmila

    2005-12-01

    The recently generated database of microbial genes from an oligotrophic environment populated by a calculated 1800 major phylotypes (the Sargasso Sea metagenome-SSM) presents a great source for expanding local databases of genes indicative of a specific function. In this article we analyse the SSM for the presence of methanopterin-linked C1 transfer genes that are signature for methylotrophy. We conclude that more than 10 phylotypes possessing genes of interest are present in this environment. The sequences representative of these major phylotypes do not appear to belong to any known microbial group capable of methanopterin-linked C1 transfer. Instead, these sequences separate from all known sequences on phylogenetic trees, pointing toward their affiliation with novel microbial phyla. These data imply a broader distribution of methanopterin-linked functions in the microbial world than has been previously known.

  4. Evolution of green plants as deduced from 5S rRNA sequences.

    PubMed

    Hori, H; Lim, B L; Osawa, S

    1985-02-01

    We have constructed a phylogenic tree for green plants by comparing 5S rRNA sequences. The tree suggests that the emergence of most of the uni- and multicellular green algae such as Chlamydomonas, Spirogyra, Ulva, and Chlorella occurred in the early stage of green plant evolution. The branching point of Nitella is a little earlier than that of land plants and much later than that of the above green algae, supporting the view that Nitella-like green algae may be the direct precursor to land plants. The Bryophyta and the Pteridophyta separated from each other after emergence of the Spermatophyta. The result is consistent with the view that the Bryophyta evolved from ferns by degeneration. In the Pteridophyta, Psilotum (whisk fern) separated first, and a little later Lycopodium (club moss) separated from the ancestor common to Equisetum (horsetail) and Dryopteris (fern). This order is in accordance with the classical view. During the Spermatophyta evolution, the gymnosperms (Cycas, Ginkgo, and Metasequoia have been studied here) and the angiosperms (flowering plants) separated, and this was followed by the separation of Metasequoia and Cycas (cycad)/Ginkgo (maidenhair tree) on one branch and various flowering plants on the other. PMID:16593540

  5. The Energy of Olivine Grain Boundaries Deduced from Grain Boundary Frequency Analyses

    NASA Astrophysics Data System (ADS)

    Marquardt, K.; Rohrer, G. S.

    2015-12-01

    The properties of grain boundaries strongly differ from those of the crystal lattice, and there is growing evidence that the presence of grain boundaries influence detected geophysical signals such as electrical conductivity and seismic velocities especially in aggregates with a LPO that favours the alignment of specific grain boundaries. However, neither the anisotropic frequency or energy distribution of grain boundary networks are understood in olivine dominated aggregates, neither with nor without LPO. We used electron backscatter diffraction, EBSD to detect the orientations of over 1.4x104 grains corresponding to roughly 5000mm length of grain boundary separating them. Subsequently we used a stereological approach to determine the grain boundary character distribution, GBCD, defined as the relative areas of grain boundaries of different types, distinguished by their five degrees of freedom (Rohrer, 2007). The grain boundary planes showed a preference for low index planes, which is in agreement with recent findings on other materials (e.g. MgO, TiO2, SrTiO3, MgAl2O4). However, our inferred surface energies are controversial with respect to previously simulated surface energies (Watson et al., 1997; de Leeuw et al., 2000; Gurmani et al., 2011). We find that the principal crystallographic planes have the lowest energies and that at 60° misorientation specific grain boundaries with common [100] axis of misorientation are favored compared to 60° misorientations about random axis of rotation. This seems to support the results of (Faul and Fitz Gerald, 1999), even though our data imply that 90°/[001] (100)(010) should be even less favorable for the propagation of melt films. These differences and similarities will be discussed with respect to the different methods and their limitations. References: Faul U. H. and Fitz Gerald J. D. (1999) Phys. Chem. Miner. 26, 187-197. Gurmani S. F. et al. (2011). J. Geophys. Res. 116, B12209. De Leeuw N. H. et al. (2000) Phys. Chem. Miner. 27, 332-341. Rohrer G. S. et al. (2004) Z. Metallkd. 95, 1-18. Watson G. W., Oliver P. M. and Parker S. C. (1997) Phys. Chem. Miner. 25, 70-78.

  6. Neptune’s global circulation deduced from multi-wavelength observations

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Fletcher, Leigh N.; Luszcz-Cook, Statia; DeBoer, David; Butler, Bryan; Hammel, Heidi B.; Sitko, Michael L.; Orton, Glenn; Marcus, Philip S.

    2014-07-01

    We observed Neptune between June and October 2003 at near- and mid-infrared wavelengths with the 10-m W.M. Keck II and I telescopes, respectively; and at radio wavelengths with the Very Large Array. Images were obtained at near-infrared wavelengths with NIRC2 coupled to the adaptive optics system in both broad- and narrow-band filters between 1.2 and 2.2 μm. In the mid-infrared we imaged Neptune at wavelengths between 8 and 22 μm, and obtained slit-resolved spectra at 8-13 μm and 18-22 μm. At radio wavelengths we mapped the planet in discrete filters between 0.7 and 6 cm. We analyzed each dataset separately with a radiative-transfer program that is optimized for that particular wavelength regime. At southern midlatitudes the atmosphere appears to be cooler at mid-infrared wavelengths than anywhere else on the planet. We interpret this to be caused by adiabatic cooling due to air rising at midlatitudes at all longitudes from the upper troposphere up to ≲0.1 mbar levels. At near-infrared wavelengths we find two distinct cloud layers at these latitudes: a relatively deep layer of clouds (presumably methane) in the troposphere at pressure levels P∼300-≳600 mbar, which we suggest to be caused by the large-scale upwelling and its accompanying adiabatic cooling and condensation of methane; and a higher, spatially intermittent, layer of clouds in the stratosphere at 20-30 mbar. The latitudes of these high clouds encompass an anticyclonic band of zonal flow, which suggests that they may be due to strong, but localized, vertical upwellings associated with local anticyclones, rather than plumes in convective (i.e., cyclonic) storms. Clouds at northern midlatitudes are located at the highest altitudes in the atmosphere, near 10 mbar. Neptune’s south pole is considerably enhanced in brightness at both mid-infrared and radio wavelengths, i.e., from ∼0.1 mbar levels in the stratosphere down to tens of bars in the troposphere. We interpret this to be due to subsiding motions from the stratosphere all the way down to the deep troposphere. The enhanced brightness observed at mid-infrared wavelengths is interpreted to be due to adiabatic heating by compression in the stratosphere, and the enhanced brightness temperature at radio wavelengths reveals that the subsiding air over the pole is very dry; the relative humidity of H2S over the pole is only 5% at altitudes above the NH4SH cloud at ∼40 bar. The low humidity region extends from the south pole down to latitudes of 66°S. This is near the same latitudes as the south polar prograde jet signifying the boundary of the polar vortex. We suggest that the South Polar Features (SPFs) at latitudes of 60-70° are convective storms, produced by baroclinic instabilities expected to be produced at latitudes near the south polar prograde jet. Taken together, our data suggest a global circulation pattern where air is rising above southern and northern midlatitudes, from the troposphere up well into the stratosphere, and subsidence of dry air over the pole and equator from the stratosphere down into the troposphere. We suggest that this pattern extends all the way from ≲0.1 mbar down to pressures of ≳40 bar.

  7. Holocene dynamics of the Rhone Glacier, Switzerland, deduced from ice flow models and cosmogenic nuclides

    NASA Astrophysics Data System (ADS)

    Goehring, Brent M.; Vacco, David A.; Alley, Richard B.; Schaefer, Joerg M.

    2012-10-01

    We describe efforts to model the Holocene extent of the Rhone Glacier, Switzerland, using four paleoclimate records as templates for paleo-equilibrium line altitude to identify candidate driving mechanisms of glaciers in the Alps. We evaluate the success of each paleoclimate template by comparing cosmogenic 10Be and 14C concentrations in pro-glacial bedrock derived from modeled glacier configurations to measured values. An adequate fit can be obtained using mean summer insolation for 46.5°N. However, use of the Dongee Cave, China, speleothem record yields the best fit by accounting for both sub-millennial (e.g. Little Ice Age and Medieval Warm Period) and multi-millennial climate variations (summer insolation). Our result indicates that glaciers in the Alps primarily responded to changes in insolation during the Holocene were smaller than today during the early Holocene when insolation was relatively high, and became larger during the mid to late Holocene. Superimposed on the first-order insolation response were shorter, sometimes large amplitude, length changes in response to short-lived climate events such as the Medieval Warm Period and the LIA.

  8. Influence of solar wind on Jupiter's magnetosphere deduced from currents in the equatorial plane

    NASA Astrophysics Data System (ADS)

    Khurana, Krishan K.

    2001-11-01

    Galileo is the sixth spacecraft to have visited Jupiter's magnetosphere. Among them the six spacecraft have sampled a fairly large expanse of magnetospheric local times and latitudes under varying solar wind conditions. An adequate (though not optimum) database of field and particles now exists that makes it possible to map the current circuits at a global scale. We have used the magnetic field observations from all six of the spacecraft to compute the electric current density in the equatorial plane of Jupiter's magnetosphere by making certain appropriate assumptions. We show that in the middle magnetosphere the azimuthal currents are much stronger on the nightside (~144 MA between the radial distances of 10 and 50RJ) than they are on the dayside (~88 MA in the same distance range). From current continuity considerations we conclude that the nightside partial ring current is fed and emptied by field-aligned currents in the dusk and the dawn sectors, respectively. These currents are similar (but opposite in polarity) to Region 2 field-aligned currents observed in the Earth's magnetosphere. Because the presence of Region 1 or 2 sense field-aligned currents in a magnetosphere indicates the presence of solar wind driven convection in a magnetosphere, a surprising conclusion of the present analysis is that the solar wind influence reaches deep into the heart of Jupiter's magnetosphere. Other findings of this study are that (1) the equatorial field strength is remarkably constant over all local times, (2) the equatorial source of the outward field-aligned currents required for the generation of aurorae is located between the radial distances of 10 and 30RJ with a peak near 20RJ, and (3) the Jovian magnetosphere displays a magnetic field configuration intermediate to a Parker spiral and a magnetosphere driven by solar wind.

  9. Late-glacial to Holocene transition in northern Spain deduced from land-snail shelly accumulations

    NASA Astrophysics Data System (ADS)

    Yanes, Yurena; Gutiérrez-Zugasti, Igor; Delgado, Antonio

    2012-09-01

    Shells of the helicid Cepaea nemoralis were studied using taphonomic, isotopic and morphometric measurements to estimate late glacial-Holocene (~ 12.1-6.3 cal ka BP) environmental conditions in northern Spain. Higher taphonomic alteration among Holocene shells suggests lower sedimentation rates or higher shell-destruction rates than during glacial conditions. Shells preserved the aragonitic composition despite differing degree of skeleton damage. Shell δ13C values were - 10.3 ± 1.1‰, - 8.2 ± 2.3‰, and - 7.3 ± 1.6‰ for modern, Holocene and late-glacial individuals, respectively. Higher δ13C values during the late-glacial and some Holocene periods imply higher water stress of C3 plants and/or higher limestone contribution than today. Intrashell δ13C values were higher during juvenile stages suggesting higher limestone ingestion to promote shell growth. Shell δ18O values were - 1.1 ± 0.7‰, - 0.9 ± 0.8‰ and - 0.1 ± 0.7‰ for modern, Holocene and late-glacial specimens, respectively. A snail flux-balance model suggests that during ~ 12.1 - 10.9 cal ka BP conditions were drier and became wetter at ~ 8.4 - 6.3 cal ka BP and today. Intrashell δ18O profiles reveal that glacial individuals experienced more extreme seasonality than interglacial shells, despite possible larger hibernation periods. Shell size correlated positively with δ18O values, suggesting that growth rates and ultimate adult size of C. nemoralis may respond to climate fluctuation in northern Spain.

  10. Genetic map of the calicivirus rabbit hemorrhagic disease virus as deduced from in vitro translation studies.

    PubMed Central

    Wirblich, C; Thiel, H J; Meyers, G

    1996-01-01

    The 7.5-kb plus-stranded genomic RNA of rabbit hemorrhagic disease virus contains two open reading frames of 7 kb (ORF1) and 351 nucleotides (ORF2) that cover nearly 99% of the genome. The aim of the present study was to identify the proteins encoded in these open reading frames. To this end, a panel of region-specific antisera was generated by immunization of rabbits with bacterially expressed fusion proteins that encompass in total 95% of the ORF1 polyprotein and almost the complete ORF2 polypeptide. The antisera were used to analyze the in vitro translation products of purified virion RNA of rabbit hemorrhagic disease virus. Our studies show that the N-terminal half of the ORF1 polyprotein is proteolytically cleaved to yield three nonstructural proteins of 16, 23, and 37 kDa (p16, p23, and p37, respectively). In addition, a cleavage product of 41 kDa which is composed of VPg and a putative nonstructural protein of approximately 30 kDa was identified. Together with the results of previous studies which identified a trypsin-like cysteine protease (TCP) of 15 kDa, a putative RNA polymerase (pol) of 58 kDa, and the major capsid protein VP60, our data establish the following gene order in ORF1: NH2-p16-p23-p37 (helicase)-p30-VPg-TCP-pol-VP60-COOH. Immunoblot analyses showed that a minor structural protein of 10 kDa is encoded in ORF2. The data provide the first complete genetic map of a calicivirus. The map reveals a remarkable similarity between caliciviruses and picornaviruses with regard to the number and order of the genes that encode the nonstructural proteins. PMID:8892921

  11. Charge rearrangement deduced from nearby electric field measurements of an intracloud flash with K‒changes

    NASA Astrophysics Data System (ADS)

    Hager, William W.; Feng, Wei

    2013-09-01

    An intracloud flash near Langmuir Laboratory is analyzed to determine the net rearrangement of charge. The analysis employed data from a balloon borne electric field sensor, or Esonde, that was within a few hundred meters of the lightning channel, data from a similar Esonde on a mountain about 6.4 km from the balloon, and data from the New Mexico Institute of Mining and Technology Lightning Mapping Array (LMA). The recovery of the charge transport required the solution of Poisson's equation over the mountainous terrain surrounding Langmuir Laboratory and the solution of a vastly under‒determined system of equations. The charge movement is analyzed using a new smooth charge transport model that incorporates constraints in the least squares fitting process through the use of penalty terms to smooth the charge movement and prevent data overfitting. The electric field measurements were consistent with about 26% of the negative charge being transported to the end of the channel, 36% deposited along the channel in the positive region, 8% deposited near the start of the channel in the positive region, and 30% deposited in another positive region several kilometers beneath the main channel. The transport of negative charge to a lower positive region occurred during the K‒processes when some negative charge was also deposited along the main channel in the upper positive region. Hence, the charge transport process during the K‒processes amounted to a tripolar charge rearrangement where the charge from the negative region was transported to two distinct positive regions, the positive region along the main channel and a lower positive region beneath the main channel. High altitude, widely scattered LMA sources beyond the end of the main channel could indicate the existence of streamers which transported the end‒of‒channel charge into the surrounding volume. Although the LMA showed the development of two upper channels, the charge transport analysis showed that measurable charge transport only occurred on one of the channels. The channel that did not transport charge was missing the high altitude, widely scattered LMA sources seen at the end of the channel that carried charge.

  12. Using intramolecular disulfide bonds in tau protein to deduce structural features of aggregation-resistant conformations.

    PubMed

    Walker, Sophie; Ullman, Orly; Stultz, Collin M

    2012-03-16

    Because tau aggregation likely plays a role in a number of neurodegenerative diseases, understanding the processes that affect tau aggregation is of considerable importance. One factor that has been shown to influence the aggregation propensity is the oxidation state of the protein itself. Tau protein, which contains two naturally occurring cysteine residues, can form both intermolecular disulfide bonds and intramolecular disulfide bonds. Several studies suggest that intermolecular disulfide bonds can promote tau aggregation in vitro. By contrast, although there are data to suggest that intramolecular disulfide bond formation retards tau aggregation in vitro, the precise mechanism underlying this observation remains unclear. While it has been hypothesized that a single intramolecular disulfide bond in tau leads to compact conformations that cannot form extended structure consistent with tau fibrils, there are few data to support this conjecture. In the present study we generate oxidized forms of the truncation mutant, K18, which contains all four microtubule binding repeats, and isolate the monomeric fraction, which corresponds to K18 monomers that have a single intramolecular disulfide bond. We study the aggregation propensity of the oxidized monomeric fraction and relate these data to an atomistic model of the K18 unfolded ensemble. Our results argue that the main effect of intramolecular disulfide bond formation is to preferentially stabilize conformers within the unfolded ensemble that place the aggregation-prone tau subsequences, PHF6* and PHF6, in conformations that are inconsistent with the formation of cross-β-structure. These data further our understanding of the precise structural features that retard tau aggregation.

  13. The structure of the magnetosphere as deduced from magnetospherically reflected whistlers

    NASA Technical Reports Server (NTRS)

    Edgar, B. C.

    1972-01-01

    Very low frequency (VLF) electromagnetic wave phenomenon called the magnetospherically reflected (MR) whistler was investigated. VLF (0.3 to 12.5 kHz) data obtained from the Orbiting Geophysical Observatories 1 and 3 from October 1964 to December 1966 were used. MR whistlers are produced by the dispersive propagation of energy from atmospheric lightning through the magnetosphere to the satellite along ray paths which undergo one or more reflections due to the presence of ions. The gross features of MR whistler frequency-time spectrograms are explained in terms of propagation through a magnetosphere composed of thermal ions and electrons and having small density gradients across L-shells. Irregularities observed in MR spectra were interpreted in terms of propagation through field-aligned density structures. Trough and enhancement density structures were found to produce unique and easily recognizable signatures in MR spectra. Sharp cross-field density dropoff produces extra traces in MR spectrograms.

  14. Properties of CIRRUS Overlapping Clouds as Deduced from the GOES-12 Imagery Data

    NASA Technical Reports Server (NTRS)

    Chang, Fu-Lung; Minnis, Patrick; Lin, Bing; Sun-Mack, Sunny; Khaiyer, Mandana

    2006-01-01

    Understanding the impact of cirrus clouds on modifying both the solar reflected and terrestrial emitted radiations is crucial for climate studies. Unlike most boundary layer stratus and stratocumulus clouds that have a net cooling effect on the climate, high-level thin cirrus clouds can have a warming effect on our climate. Many research efforts have been devoted to retrieving cirrus cloud properties due to their ubiquitous presence. However, using satellite observations to detect and/or retrieve cirrus cloud properties faces two major challenges. First, they are often semitransparent at visible to infrared wavelengths; and secondly, they often occur over a lower cloud system. The overlapping of high-level cirrus and low-level stratus cloud poses a difficulty in determining the individual cloud top altitudes and optical properties, especially when the signals from cirrus clouds are overwhelmed by the signals of stratus clouds. Moreover, the operational satellite retrieval algorithms, which often assume only single layer cloud in the development of cloud retrieval techniques, cannot resolve the cloud overlapping situation properly. The new geostationary satellites, starting with the Twelfth Geostationary Operational Environmental Satellite (GOES-12), are providing a new suite of imager bands that have replaced the conventional 12-micron channel with a 13.3-micron CO2 absorption channel. The replacement of the 13.3-micron channel allows for the application of a CO2-slicing retrieval technique (Chahine et al. 1974; Smith and Platt 1978), which is one of the important passive satellite methods for remote sensing the altitudes of mid to high-level clouds. Using the CO2- slicing technique is more effective in detecting semitransparent cirrus clouds than using the conventional infrared-window method.

  15. Metallic abundances of the 2002 Leonid meteor deduced from high-definition TV spectra

    NASA Astrophysics Data System (ADS)

    Kasuga, T.; Yamamoto, T.; Watanabe, J.; Ebizuka, N.; Kawakita, H.; Yano, H.

    2005-05-01

    High-definition TV spectra in the ultraviolet-visible region were obtained during the 2002 Leonid aircraft campaign. We analyze the spectra of the brightest fireball that appeared at 03h 47m 54s UT on Nov. 19, 2002 and identify the neutral atoms, mainly MgI, FeI, CaI, and NaI in the observed wavelengths between 300-650 nm. The singly ionized atomic emissions, CaII and MgII lines, also appeared in the spectrum in several epochs during the series of video frames. From analysis of the spectra, time variation in the abundances of metallic atoms, along with their electronic excitation and blackbody temperatures, were obtained assuming the Local Thermal Equilibrium (LTE) condition. Both Fe and Ca abundances relative to Mg are lower than the solar abundance, while Na is slightly higher. We found correlation between the excitation temperature and the abundance of Ca, which suggests incomplete evaporation of the Ca due to intrinsic refractoriness. A search for bands of CHON-related molecules, such as OH and CN, is not successful in the brightest fireball in this study.

  16. Fishing for biodiversity: Novel methanopterin-linked C1 transfergenes deduced from the Sargasso Sea metagenome

    SciTech Connect

    Kalyuzhnaya, Marina G.; Nercessian, Olivier; Lapidus, Alla; Chistoserdova, Ludmila

    2004-07-01

    The recently generated database of microbial genes from anoligotrophic environment populated by a calculated 1,800 of major phylotypes (the Sargasso Sea metagenome) presents a great source for expanding local databases of genes indicative of a specific function. In this paper we analyze the Sargasso Sea metagenome in terms of the presence of methanopterin-linked C1 transfer genes that are signature for methylotrophy. We conclude that more than 10 phylotypes possessing genes of interest are present in this environment, and a few of these are relatively abundant species. The sequences representative of the major phylotypes do not appear to belong to any known microbial group capable of methanopterin-linked C1 transfer. Instead, they separate from all known sequences on phylogenetic trees, pointing towards their affiliation with a novel microbial phylum. These data imply a broader distribution of methanopterin-linked functions in the microbial world than previously known.

  17. Low Angle Contact Between the Oaxaca and Juárez Terranes Deduced From Magnetotelluric Data

    NASA Astrophysics Data System (ADS)

    Arzate-Flores, Jorge A.; Molina-Garza, Roberto; Corbo-Camargo, Fernando; Márquez-Ramírez, Víctor

    2016-10-01

    We present the electrical resistivity model along a profile perpendicular to the Middle America trench in southern Mexico that reveals previously unrecognized tectonic features at upper to mid-crustal depths. Our results support the hypotheses that the upper crust of the Oaxaca terrane is a residual ~20 km thick crust composed by an ~10 km thick faulted crustal upper layer and an ~10 km thick hydrated and/or mineralized layer. Oaxaca basement overthrust the younger Juárez (or Cuicateco) terrane. The electrical resistivity model supports the interpretation of a slab subducting at a low angle below Oaxaca. Uplift in the Oaxaca region appears to be related to fault reactivation induced by low angle subduction. In the Juárez terrane, isostatic forces may contribute to uplift because it is largely uncompensated. In the Sierra Madre del Sur, closer to the coast, uplift is facilitated by slab-dehydration driven buoyancy. Both gravity and resistivity models are consistent with a thinned upper crust in the northeast end of the profile.

  18. Thermal regimes in the detachment fault environment as deduced from fluid inclusions

    NASA Technical Reports Server (NTRS)

    Beane, R. E.; Wilkins, J., Jr.; Heidrick, T. L.

    1985-01-01

    Extensional tectonism, which dominates middle- and late-Tertiary geology in western Arizona, southeastern California, and southern Nevada, is characterized by normal regionally extensive, low-angle detachment faults. The decollement movement of Fupper plate rocks relative to lower plate assemblages created extensive zones of dilatency, including synthetic and antithetic listric normal faults, tear faults, tectonic crush breccias, shatter breccias, and gash veins in lithologic units above and below the detachment. The tectonically enhanced permeability above and below the detachment fault permitted mass migration of large volumes of hydrothermal solutions along the fault zone during and following upper plate movement. Major quantities of MgO, CaO, K2O, FeO/Fe2O3, SiO2 and CO2 were added to rocks in and near the detachment and related structures. Also introduced were varying amounts of trace elements including Mn, Cu, S, Mo, Ba, Au, Pb, Zn, U and/or Ag. Minerals containing fluid incusions were collected from all of these loci at locations in detachment faulted terranes in western Arizona and southeastern California.

  19. High-frequency Earth rotation variations deduced from altimetry-based ocean tides

    NASA Astrophysics Data System (ADS)

    Madzak, Matthias; Schindelegger, Michael; Böhm, Johannes; Bosch, Wolfgang; Hagedoorn, Jan

    2016-06-01

    A model of diurnal and semi-diurnal variations in Earth rotation parameters (ERP) is constructed based on altimetry-measured tidal heights from a multi-mission empirical ocean tide solution. Barotropic currents contributing to relative angular momentum changes are estimated for nine major tides in a global inversion algorithm that solves the two-dimensional momentum equations on a regular 0.5° grid with a heavily weighted continuity constraint. The influence of 19 minor tides is accounted for by linear admittance interpolation of ocean tidal angular momentum, although the assumption of smooth admittance variations with frequency appears to be a doubtful concept for semi-diurnal mass terms in particular. A validation of the newly derived model based on post-fit corrections to polar motion and universal time (Δ UT1) from the analysis of Very Long Baseline Interferometry (VLBI) observations shows a variance reduction for semi-diurnal Δ UT1 residuals that is significant at the 0.05 level with respect to the conventional ERP model. Improvements are also evident for the explicitly modeled K_1 , Q_1 , and K_2 tides in individual ERP components, but large residuals of more than 15 μ as remain at the principal lunar frequencies of O_1 and M_2 . We attribute these shortcomings to uncertainties in the inverted relative angular momentum changes and, to a minor extent, to violation of mass conservation in the empirical ocean tide solution. Further dedicated hydrodynamic modeling efforts of these anomalous constituents are required to meet the accuracy standards of modern space geodesy.

  20. Identification of widespread pollution in the Southern Hemisphere deduced from satellite analyses

    NASA Technical Reports Server (NTRS)

    Fishman, J.; Fakhruzzaman, K.; Cros, B.; Nganga, D.

    1991-01-01

    Vertical profiles of ozone obtained from ozonesondes in Brazzaville (Congo) and Ascension Island show that large quantities of tropospheric ozone are present over southern Africa and the adjacent eastern tropical South Atlantic Ocean. The origin of this pollution is widespread biomass burning in Africa. These measurements support satellite-derived tropospheric ozone data that demonstrate that ozone originating from this region is transported throughout most of the Southern Hemisphere. Seasonally high levels of CO2 and methane observed at middle- and high-latitude stations in Africa, Australia, and Antarctica likely reflect the effects of this distant biomass burning. These data suggest that even the most remote regions on this planet may be significantly more polluted than previously believed.

  1. Climatological Aspects of Aerosol Physical Characteristics in Tunisia Deduced from Sun Photometric Measurements

    PubMed Central

    Chaâbane, Mabrouk; Azri, Chafai; Medhioub, Khaled

    2012-01-01

    Atmospheric and climatic data measured at Thala site (Tunisia) for a long-time period (1977–2001) are used to analyse the monthly, seasonal, and annual variations of the aerosol optical depth at 1 μm wavelength. We have shown that aerosol and microphysical properties and the dominating aerosol types depend on seasons. A comparison of the seasonal cycle of aerosol optical characteristics at Thala site showed that the contribution of long-range transported particles is expected to be larger in summer as a consequence of the weather stability typical of this season. Also, the winter decrease in atmospheric turbidity may result from increases in relative humidity and decreases in temperature, leading to increased particle size and mass and increased fall and deposition velocities. The spring and autumn weather patterns usually carry fine dust and sand particles for the desert area to Thala region. The annual behaviour of the aerosol optical depth recorded a period of stead increase started in 1986 until 2001. Trends in atmospheric turbidity after 1988 could be explained other ways by the contribution of the eruption of Mount Pinatubo in 1991 and by local or regional changes in climate or in aerosol emissions. PMID:22629150

  2. Climate stability as deduced from an idealized coupled atmosphere-ocean model

    SciTech Connect

    Tang, B.; Weaver, A.J.

    1995-04-01

    The stability of an idealized climate system is investigated using a simple coupled atmosphere-ocean box model. Motivated by the results from general circulation models. the main physical constraint imposed on the system is that the net radiation at the top of the atmosphere is fixed. The specification of an invariant equatorial atmospheric temperature. Consistent with paleoclimatic data, allows the hydrological cycle to be internally determined from the poleward heat transport budget, resulting in a model that has a plausible representation of the hydrological cycle-thermohaline circulation interaction. The model suggests that the stability and variability of the climate system depends fundamentally on the mean climatic state (total heat content of the system). When the total heat content of the climate system is low, a stable present-day equilibrium exists with high-latitude sinking. Conversely, when the total heat content is high, a stable equatorial sinking equilibrium exists. For a range of intermediate values of the total heat content, internal climatic oscillations can occur through a hydrological cycle-thermohaline circulation feedback process. Experiments conducted with the model reveal that under a 100-year 2xCO{sub 2} warming, the thermohaline circulation first collapses but then recovers. Under a 100-year 4 x CO{sub 2} warming, the thermohaline circulation collapses and remains collapsed. Recent paleoclimatic data suggest that the climate system may behave very differently for warmer climate. Our results suggest that this may be attributed to the enhanced poleward freshwater transport, which causes increased instability of the present-day thermohaline circulation. 50 refs., 4 figs., 1 tab.

  3. Domain structure of phage P4 alpha protein deduced by mutational analysis.

    PubMed Central

    Ziegelin, G; Linderoth, N A; Calendar, R; Lanka, E

    1995-01-01

    Bacteriophage P4 DNA replication depends on the product of the alpha gene, which has origin recognition ability, DNA helicase activity, and DNA primase activity. One temperature-sensitive and four amber mutations that eliminate DNA replication in vivo were sequenced and located in the alpha gene. Sequence analysis of the entire gene predicted a domain structure for the alpha polypeptide chain (777 amino acid residues, M(r) 84,900), with the N terminus providing the catalytic activity for the primase and the middle part providing that for the helicase/nucleoside triphosphatase. This model was confirmed experimentally in vivo and in vitro. In addition, the ori DNA recognition ability was found to be associated with the C-terminal third of the alpha polypeptide chain. The type A nucleotide-binding site is required for P4 replication in vivo, as shown for alpha mutations at G-506 and K-507. In the absence of an active DnaG protein, the primase function is also essential for P4 replication. Primase-null and helicase-null mutants retain the two remaining activities functionally in vitro and in vivo. The latter was demonstrated by trans complementation studies, indicating the assembly of active P4 replisomes by a primase-null and a helicase-null mutant. PMID:7635818

  4. The Hengill geothermal area, Iceland: variation of temperature gradients deduced from the maximum depth of seismogenesis

    USGS Publications Warehouse

    Foulger, G.R.

    1995-01-01

    Given a uniform lithology and strain rate and a full seismic data set, the maximum depth of earthquakes may be viewed to a first order as an isotherm. These conditions are approached at the Hengill geothermal area, S. Iceland, a dominantly basaltic area. The temperature at which seismic failure ceases for the strain rates likely at the Hengill geothermal area is determined by analogy with oceanic crust, and is about 650 ?? 50??C. The topographies of the top and bottom of the seismogenic layer were mapped using 617 earthquakes. The thickness of the seismogenic layer is roughly constant and about 3 km. A shallow, aseismic, low-velocity volume within the spreading plate boundary that crosses the area occurs above the top of the seismogenic layer and is interpreted as an isolated body of partial melt. The base of the seismogenic layer has a maximum depth of about 6.5 km beneath the spreading axis and deepens to about 7 km beneath a transform zone in the south of the area. -from Author

  5. Temperature and density dependence of properties of nuclear matter deduced from heavy ion collisions

    SciTech Connect

    Shlomo, Shalom

    2010-11-24

    Heavy-ion collision experiments are often employed to determine properties of nuclear matter under extreme conditions of temperature and density. This has been the subject of many investigations in recent decades, since understanding the equation of state of hot nuclear matter is very important in the study supernovae, neutron stars and nuclei. We present a short and limited review of the theoretical and experimental status of determining the temperature and density of the disassembling hot nucleus from ratios of the yields of emitted fragments.

  6. Deduced amino acid sequence of human pulmonary surfactant proteolipid: SPL(pVal)

    SciTech Connect

    Whitsett, J.A.; Glasser, S.W.; Korfhagen, T.R.; Weaver, T.E.; Clark, J.; Pilot-Matias, T.; Meuth, J.; Fox, J.L.

    1987-05-01

    Hydrophobic, proteolipid-like protein of Mr 6500 was isolated from ether/ethanol extracts of human, canine and bovine pulmonary surfactant. Amino acid composition of the protein demonstrated a remarkable abundance of hydrophobic residues, particularly valine and leucine. The N-terminal amino acid sequence of the human protein was determined: N-Leu-Ile-Pro-Cys-Cys-Pro-Val-Asn-Leu-Lys-Arg-Leu-Leu-Ile-Val4... An oligonucleotide probe was used to screen an adult human lung cDNA library and resulted in detection of cDNA clones with predicted amino acid sequence with close identity to the N-terminal amino acid sequence of the human peptide. SPL(pVal) was found within the reading frame of a larger peptide. SPL(pVal) results from proteolytic processing of a larger preprotein. Northern blot analysis detected in a single 1.0 kilobase SPL(pVal) RNA which was less abundant in fetal than in adult lung. Mixtures of purified canine and bovine SPL(pVal) and synthetic phospholipids display properties of rapid adsorption and surface tension lowering activity characteristic of surfactant. Human SPL(pVal) is a pulmonary surfactant proteolipid which may therefore be useful in combination with phospholipids and/or other surfactant proteins for the treatment of surfactant deficiency such as hyaline membrane disease in newborn infants.

  7. Properties of solar flare electrons, deduced from hard X-ray and spatially resolved microwave observations

    NASA Technical Reports Server (NTRS)

    Marsh, K. A.; Hurford, G. J.; Zirin, H.; Dulk, G. A.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.

    1981-01-01

    An important question concerning an understanding of impulsive solar flares is related to the energetic electrons responsible for the microwave and the hard X-ray emission. A description is presented of an investigation in which spatially resolved microwave observations of an impulsive flare and hard X-ray data from the Solar Maximum Mission (SMM) are used to test the hypothesis that the two types of emission come from the same basic electron population. The considered observations are found to imply that the microwaves and hard X-rays were not produced by a common population of electrons with either a Maxwellian or single power-law energy distribution. It is suggested that the calculations should be repeated when observations of stronger events become available, for which a better determination of the X-ray spectrum is possible. The possibility is considered that microwaves and moderately hard X-rays come from spatially different regions.

  8. Volcanic and glacial evolution of Chachani-Nocarane complex (Southern Peru) deduced from the geomorphologic map.

    NASA Astrophysics Data System (ADS)

    Alcalá, J.; Zamorano, J. J.; Palacios, D.

    2012-04-01

    The Chachani-Nocarane (16°11'S; 71°31'W; 6.057 m asl) is a large volcanic complex located in the western Central-Andean Cordillera, South of Peru. The date of the last eruption is not known and there are no registers of recent volcanic activity. The complex is shaped by glacial forms belonging to different phases, and periglacial forms (several generations of rock glaciers) which alternate with volcanic forms. The aim of this research is to establish the glacio-volcanic evolution of the volcanic complex Chachani-Nocarane. In order to do so, a detailed 1:20.000 scale geomorphological map was elaborated by integrating the following techniques: interpretation of the 1:35.000 scale aerial photographs (Instituto Geográfico Nacional de Perú, 1956) and the analysis of satellite images (Mrsid; NASA, 2000). Finally, the cartography was corrected though field work campaigns. Through the geomorphologic analysis of the landforms and their relative position, we have identified twelve phases, seven volcanic and five glacial phases. The most ancient volcanic phase is locate to the north area of the study area and correspond with Nocarane and Chingana volcanoes, alignment NW-SE. Above those ensemble the rest of the large delimited geomorphological units overlap. The most recent is located to the SW and consists of a complex series of domes, lava cones and voluminous lavas. Within the glacial phases, the most ancient one is related to the Last Glacial Maximum during the Pleistocene. Over this period, glaciers formed moraines from 3150 to 3600 m asl. The most recent glacier pulsation corresponds to the Little Ice Age (LIA). The moraines related to that event are the closest to the summits, located between 5.100 and 5.300 m asl, and they represent the last trace of glacial activity on the volcanic complex. Currently, this tropical mountain does not have glaciers. The only solid-state water reserves are found in the form of permafrost, as shown by various generations of rock glaciers placed in the upper part of the mountain, between 4.300 and 5.400 m asl in Nevado Nocarane and between 4.350 and 5.100 m asl in Nevado Chachani. Most of the delimited rock glaciers were formed under vertical walls where the supply of detritus material is significant. The generation of rock glaciers found at a higher altitude presents geomorphological indicators of current activity. Research funded by CGL2009-7343 project, Government of Spain.

  9. Personality Theories Facilitate Integrating the Five Principles and Deducing Hypotheses for Testing

    ERIC Educational Resources Information Center

    Maddi, Salvatore R.

    2007-01-01

    Comments on the original article "A New Big Five: Fundamental Principles for an Integrative Science of Personality," by Dan P. McAdams and Jennifer L. Pals (see record 2006-03947-002). In presenting their view of personality science, McAdams and Pals (April 2006) elaborated the importance of five principles for building an integrated science of…

  10. Outbreaks of Yuzu Dieback in Goheung Area: Possible Causes Deduced from Weather Extremes

    PubMed Central

    Kim, Kwang-Hyung; Kim, Gyoung Hee; Son, Kyeong In; Koh, Young Jin

    2015-01-01

    Starting in 2012, severe diebacks usually accompanied by abundant gum exudation have occurred on yuzu trees in Goheung-gun, Jeonnam Province, where severely affected trees were occasionally killed. On-farm surveys were conducted at 30 randomly-selected orchards located at Pungyang-myeon, Goheung-gun, and the resulting disease incidences were 18.5% and 39.6% for dieback and gumming symptoms, respectively. Black spots on branches and leaves also appeared on infected trees showing a typical dieback symptom. Morphological and molecular identifications of the isolated fungal organisms from lesions on the symptomatic leaves and branches revealed that they are identical to Phomopsis citri, known to cause gummosis. In order to find the reason for this sudden epidemic, we investigated the weather conditions that are exclusively distinct from previous years, hypothesizing that certain weather extremes might have caused the severe induction of pre-existing disease for yuzu. There were two extreme temperature drops beyond the yuzu’s cold hardiness limit right after an abnormally-warm-temperature-rise during the winter of 2011–12, which could cause severe frost damage resulting in mechanical injuries and physiological weakness to the affected trees. Furthermore, there was an increased frequency of strong wind events, seven times in 2012 compared to only a few times in the previous years, that could also lead to extensive injuries on branches. In conclusion, we estimated that the possible damages by severe frost and frequent strong wind events during 2012 could cause the yuzu trees to be vulnerable to subsequent fungal infection by providing physical entries and increasing plant susceptibility to infections. PMID:26361477

  11. Stratospheric warmings in the Southern Hemisphere deduced from satellite radiation data, 1969-73

    NASA Technical Reports Server (NTRS)

    Quiroz, R. S.

    1974-01-01

    The investigation is largely based on radiation data from the vertical temperature profile radiometers on the satellite NOAA 2. The physical-statistical interpretation of the radiance data is considered. Aspects regarding the nonuniqueness of the minor warming in August 1973 are discussed. It is pointed out that conditions leading to major warmings in the Northern Hemisphere were not satisfied in the Southern Hemisphere during the period from 1969 to 1973.

  12. Influence of Pore Structure on SIP Properties Deduced from Micro-Scale Modelling

    NASA Astrophysics Data System (ADS)

    Volkmann, Jan; Klitzsch, Norbert; Wiens, Eugen; Mohnke, Oliver

    2010-05-01

    In geophysics frequency dependent complex resistivity measurements are called Spectral Induced Polarization (SIP). In other fields this method is known as Impedance Spectroscopy. In the last two decades many empirical relations were proposed which relate the frequency dependent electrical properties of water saturated rocks to structural properties such as pore radius and inner surface area, or to hydraulic conductivity. Unfortunately, these relations are not universal; they apply only for specific rock types and water compositions. In order to quantify the influence of inner rock structure (as well as of electrochemical water and rock properties) on the frequency dependent electrical properties we model the charge transport processes at the pore space using Comsol Multiphysics. In the frequency domain the effect of Induced Polarization (IP) is characterised by a phase shift between a measured electric current and an alternating voltage applied to the ground. A possible origin of this behaviour particularly for nonconducting rock minerals can be seen in the membrane polarization model as proposed by Marshall and Madden. This model describes a system of electrolyte filled pores. Different mobilities of cations and anions in the small pores cause a membrane effect and thus an electrical polarization. We aim to find a more realistic way of modelling the membrane polarization effect than using the simple Marshall and Madden model. The electric double layer, the origin of the Induced Polarization effect, is caused by surface charges located at the electrolyte rock interface. Thus, the EDL as a boundary effect is accounted for by reduced ion mobilities at the inner surface area. The governing equations and boundary conditions for a system of larger and smaller pores with applied voltage are expressed in frequency domain using a time harmonic approach, the electric current is determined to obtain information about amplitude and phase of the complex resistivity. The results are compared to corresponding theoretic and experimental results. The model is applied to study the influence of pore sizes and pore structure as well as of electrolyte properties like ion mobilities and concentrations. We find two characteristic phase minima in the frequency range 1mHz - 100MHz. The dependence of the 'high frequency' minimum (f > 10kHz) on the electrolyte concentration and the dependence of the corresponding relaxation times on variations of the pore geometry are in good agreement with the classical Maxwell-Wagner theory. In contrast to this effective medium approach the simulations confirm the necessity of pore throats to obtain non-vanishing phase values. For large size differences of the smaller and larger pores a second 'low frequency' minimum (f < 10kHz) exists. Its relaxation time mainly depends on the length of the large pores of the system. Furthermore we find a decreasing phase amplitude with increasing electrolyte concentration not predicted by Marshall and Madden and similar models but confirmed by experimental results. This study was conducted within the Transregional Collaborative Research Centre 32 (SFB TR 32; subproject A2), funded by the German Research Foundation (DFG). Present and future studies are supported by the Deutsche Gesellschaft für Erdöl, Erdgas und Kohle e.V. (DGMK).

  13. Hydrology of the Greater Tongonan geothermal system, Philippines, as deduced from geochemical and isotopic data

    SciTech Connect

    Alvis-Isidro, R.R.; Solana, R.R.; D`amore, F.; Nuti, S.; Gonfiantini, R.

    1993-10-01

    Fluids in the Greater Tongonan geothermal system exhibit a large positive {sup 18}O shift from the Leyte meteoric water line. However, there is also a significant shift in {sup 2}H. The {delta}{sup 2}H-{delta}{sup 18}O plot shows that the geothermal fluids may be derived by the mixing of meteoric water with local magmatic water. The most enriched water in the Greater Tongonan system, in terms of {delta}{sup 18}O, {delta}{sup 2}H and Cl, is comprised of approximately 40% magmatic water. Baseline isotope results support a hydrogeochemical model in which there is increasing meteoric water dilution to the southeast, from Mahiao to Sambaloran and towards Malitbog. The Cl-{delta}{sup 18}O plot confirms that the geothermal fluid in Mahanagdong, further southeast, is distinct from that of the Mahiao-Sambaloran-Malitbog system.

  14. Holocene oceanographic and climatic variability of the Vega Drift deduced through foraminiferal interpretation

    USGS Publications Warehouse

    Szymcek, Phillip; Ishman, Scott E.; Domack, Eugene W.; Leventer, Amy

    2007-01-01

    fusiformis assemblages. Most agglutinated forms tend to decrease downcore, and comparisons to modern analogues imply post-depositional disintegration, while calcareous taxa indicate non-corrosive bottom waters. The lower to middle Holocene Vega Drift sediments are characterized by the calcareous S. fusiformis assemblage and glacial plume sediments. This assemblage is characterized by calcareous forms including Globocassidulina biora, G. subglobosa, and Nonionella iridea. The planktic species Neogloboquadrina pachyderma is associated with the S. fusiformis assemblage. The S. fusiformis assemblage is faunally similar to assemblages described in fjords of the western Antarctic Peninsula and indicates non-corrosive bottom water. Sediments of the mid to upper Holocene interval are characterized by the T. wiesneri and M. arenacea assemblages and indicate the presence of Hyper Saline Shelf Water. These assemblages are similar to modern assemblages directly to the south in the Prince Gustav Channel. The upper Holocene is marked by several small intervals with taxonomic characteristics similar to the S. fusiformis assemblage, indicating periodic introduction of non-corrosive bottom water to the Vega Drift

  15. Constructing a folding model for protein S6 guided by native fluctuations deduced from NMR structures

    SciTech Connect

    Lammert, Heiko; Noel, Jeffrey K.; Haglund, Ellinor; Onuchic, José N.; Schug, Alexander

    2015-12-28

    The diversity in a set of protein nuclear magnetic resonance (NMR) structures provides an estimate of native state fluctuations that can be used to refine and enrich structure-based protein models (SBMs). Dynamics are an essential part of a protein’s functional native state. The dynamics in the native state are controlled by the same funneled energy landscape that guides the entire folding process. SBMs apply the principle of minimal frustration, drawn from energy landscape theory, to construct a funneled folding landscape for a given protein using only information from the native structure. On an energy landscape smoothed by evolution towards minimal frustration, geometrical constraints, imposed by the native structure, control the folding mechanism and shape the native dynamics revealed by the model. Native-state fluctuations can alternatively be estimated directly from the diversity in the set of NMR structures for a protein. Based on this information, we identify a highly flexible loop in the ribosomal protein S6 and modify the contact map in a SBM to accommodate the inferred dynamics. By taking into account the probable native state dynamics, the experimental transition state is recovered in the model, and the correct order of folding events is restored. Our study highlights how the shared energy landscape connects folding and function by showing that a better description of the native basin improves the prediction of the folding mechanism.

  16. The optical luminosity function of gamma-ray bursts deduced from ROTSE-III observations

    SciTech Connect

    Cui, X. H.; Wu, X. F.; Wei, J. J.; Yuan, F.; Zheng, W. K.; Liang, E. W.; Akerlof, C. W.; McKay, T. A.; Ashley, M. C. B.; Flewelling, H. A.; Göǧüş, E.; Güver, T.; Kızıloǧlu, Ü.; Pandey, S. B.; Rykoff, E. S.; Rujopakarn, W.; Schaefer, B. E.; Wheeler, J. C.; Yost, S. A. E-mail: xfwu@pmo.ac.cn E-mail: fang.yuan@anu.edu.au E-mail: lew@gxu.edu.cn

    2014-11-10

    We present the optical luminosity function (LF) of gamma-ray bursts (GRBs) estimated from a uniform sample of 58 GRBs from observations with the Robotic Optical Transient Search Experiment III (ROTSE-III). Our GRB sample is divided into two sub-samples: detected afterglows (18 GRBs) and those with upper limits (40 GRBs). We derive R-band fluxes for these two sub-samples 100 s after the onset of the burst. The optical LFs at 100 s are fitted by assuming that the co-moving GRB rate traces the star formation rate. While fitting the optical LFs using Monte Carlo simulations, we take into account the detection function of ROTSE-III. We find that the cumulative distribution of optical emission at 100 s is well described by an exponential rise and power-law decay, a broken power law,and Schechter LFs. A single power-law (SPL) LF, on the other hand, is ruled out with high confidence.

  17. DAX1 mutations map to putative structural domains in a deduced three-dimensional model.

    PubMed Central

    Zhang, Y H; Guo, W; Wagner, R L; Huang, B L; McCabe, L; Vilain, E; Burris, T P; Anyane-Yeboa, K; Burghes, A H; Chitayat, D; Chudley, A E; Genel, M; Gertner, J M; Klingensmith, G J; Levine, S N; Nakamoto, J; New, M I; Pagon, R A; Pappas, J G; Quigley, C A; Rosenthal, I M; Baxter, J D; Fletterick, R J; McCabe, E R

    1998-01-01

    The DAX1 protein is an orphan nuclear hormone receptor based on sequence similarity in the putative ligand-binding domain (LBD). DAX1 mutations result in X-linked adrenal hypoplasia congenita (AHC). Our objective was to identify DAX1 mutations in a series of families, to determine the types of mutations resulting in AHC and to locate single-amino-acid changes in a DAX1 structural model. The 14 new mutations identified among our 17 families with AHC brought the total number of families with AHC to 48 and the number of reported mutations to 42; 1 family showed gonadal mosaicism. These mutations included 23 frameshift, 12 nonsense, and six missense mutations and one single-codon deletion. We mapped the seven single-amino-acid changes to a homology model constructed by use of the three-dimensional crystal structures of the thyroid-hormone receptor and retinoid X receptor alpha. All single-amino-acid changes mapped to the C-terminal half of the DAX1 protein, in the conserved hydrophobic core of the putative LBD, and none affected residues expected to interact directly with a ligand. We conclude that most genetic alterations in DAX1 are frameshift or nonsense mutations and speculate that the codon deletion and missense mutations give insight into the structure and function of DAX1. PMID:9529340

  18. Asymmetric Statistical Properties of the Solar Cycle 23 Deduced from Sunspots, Plages and Flare Occurrences

    NASA Astrophysics Data System (ADS)

    Zharkova, Valentina; Zharkov, S.

    2006-06-01

    The statistical properties of sunspot, active regions (plages) and filament distributions obtained from the automated Solar Feature Catalogues (SFC, http://solar.inf.brad.ac.uk) and their relation to flare distributions are presented for 1996-2005. We present distributions of sunspot numbers with given areas for different phases and the whole solar cycle 23. Statistical sunspot and plage area distributions revealed a strong North-South asymmetry of about 0.2-0.6 for sunspots, plages and flare occurrences with two basic periods of about 9 and 2.5 years. The distributions of sunspot and flare occurrences at different latitudes and longitudes in Northern and Southern hemispheres and their magnetic tilts are compared with their total and excess magnetic fields during the whole period of observations. The application of these results to the solar dynamo models is discussed.

  19. Formation des enseignants dans une perspective d'education permanente au benin

    NASA Astrophysics Data System (ADS)

    Agboton, Sébastien; Moussa, Yaya Mede

    1994-05-01

    The history of teacher training in Benin, which provides evidence of social and cultural change, suggests that a system of lifelong education should be introduced which unites formal, non-formal and informal education, all of which already exist in embryo. The education originally given to every member of society was a continuing progression from initiate to initiator, a lifelong education that involved, among other things, knowledge of agricultural production. This traditional system was disrupted by the reorganization of teacher training after 1945. Recurrent training of teachers remained inadequate because of limited external funding for in-service training, the lack of teachers, the suspension of recruitment and the closure of teacher training colleges. The 1975 reform, through the initiative known as Operation Education and Development, envisaged links between school and social environment, allying intellectual work with production. This meant a radical change in the role of the teacher, who was confronted with technical advance and was obliged to enter a difficult continuing process of self-training. Furthermore, population growth and the restrictions imposed by the World Bank have brought about developments in both lifelong learning and apprenticeship. These two elements are brought together under an initiative known as Production Scolaire Artisanale, designed for out-of-school learners and artisans. The author concludes that the creation of a coherent system of voluntary education would be possible in a society that was itself favourably disposed to education.

  20. Decadal variability in core surface flows deduced from geomagnetic observatory monthly means

    NASA Astrophysics Data System (ADS)

    Whaler, K. A.; Olsen, N.; Finlay, C. C.

    2016-10-01

    Monthly means of the magnetic field measurements at ground observatories are a key data source for studying temporal changes of the core magnetic field. However, when they are calculated in the usual way, contributions of external (magnetospheric and ionospheric) origin may remain, which make them less favourable for studying the field generated by dynamo action in the core. We remove external field predictions, including a new way of characterizing the magnetospheric ring current, from the data and then calculate revised monthly means using robust methods. The geomagnetic secular variation (SV) is calculated as the first annual differences of these monthly means, which also removes the static crustal field. SV time-series based on revised monthly means are much less scattered than those calculated from ordinary monthly means, and their variances and correlations between components are smaller. On the annual to decadal timescale, the SV is generated primarily by advection in the fluid outer core. We demonstrate the utility of the revised monthly means by calculating models of the core surface advective flow between 1997 and 2013 directly from the SV data. One set of models assumes flow that is constant over three months; such models exhibit large and rapid temporal variations. For models of this type, less complex flows achieve the same fit to the SV derived from revised monthly means than those from ordinary monthly means. However, those obtained from ordinary monthly means are able to follow excursions in SV that are likely to be external field contamination rather than core signals. Having established that we can find models that fit the data adequately, we then assess how much temporal variability is required. Previous studies have suggested that the flow is consistent with torsional oscillations (TO), solid body-like oscillations of fluid on concentric cylinders with axes aligned along the Earth's rotation axis. TO have been proposed to explain decadal timescale changes in the length-of-day. We invert for flow models where the only temporal changes are consistent with TO, but such models have an unacceptably large data misfit. However, if we relax the TO constraint to allow a little more temporal variability, we can fit the data as well as with flows assumed constant over three months, demonstrating that rapid SV changes can be reproduced by rather small flow changes. Although the flow itself changes slowly, its time derivative can be locally (temporally and spatially) large, in particular when and where core surface secular acceleration peaks. Spherical harmonic expansion coefficients of the flows are not well resolved, and many of them are strongly correlated. Averaging functions, a measure of our ability to determine the flow at a given location from the data distribution available, are poor approximations to the ideal, even when centred on points of the core surface below areas of high observatory density. Both resolution and averaging functions are noticeably worse for the toroidal flow component, which dominates the flow, than the poloidal flow component, except around the magnetic equator where averaging functions for both components are poor.

  1. Coseismic and Postseismic slip distribution of the 2007 Solomon Islands Earthquake deduced from A Bayesian Inversion

    NASA Astrophysics Data System (ADS)

    Chen, T.; Gong, X.

    2011-12-01

    In inversion of geodetic data for distribution of fault slip minimizing the first or second order derivatives of slip across fault plane is generally employed to smooth slips of neighboring patches.Smoothing parameter is subjective selected to determine the relative weight placed on fitting data versus smoothing the slip distribution.We use the Fully Bayesian Inversion method(Fukuda,2008)to simultaneously estimate the slip distribution and smoothing parameter objectively in a Bayesian framework. The distributed slips,the posterior probability density function and the smoothing parameter is formulated with Bayes' theorem and sampled with a Markov chain Monte Carlo method. Here We will apply this method to Coseismic and Postseismic displacement data from the 2007 Solomon Islands Earthquake and compare the results of this method with generally favored method.

  2. Use of Nanostructure-Initiator Mass Spectrometry to Deduce Selectivity of Reaction in Glycoside Hydrolases.

    PubMed

    Deng, Kai; Takasuka, Taichi E; Bianchetti, Christopher M; Bergeman, Lai F; Adams, Paul D; Northen, Trent R; Fox, Brian G

    2015-01-01

    Chemically synthesized nanostructure-initiator mass spectrometry (NIMS) probes derivatized with tetrasaccharides were used to study the reactivity of representative Clostridium thermocellum β-glucosidase, endoglucanases, and cellobiohydrolase. Diagnostic patterns for reactions of these different classes of enzymes were observed. Results show sequential removal of glucose by the β-glucosidase and a progressive increase in specificity of reaction from endoglucanases to cellobiohydrolase. Time-dependent reactions of these polysaccharide-selective enzymes were modeled by numerical integration, which provides a quantitative basis to make functional distinctions among a continuum of naturally evolved catalytic properties. Consequently, our method, which combines automated protein translation with high-sensitivity and time-dependent detection of multiple products, provides a new approach to annotate glycoside hydrolase phylogenetic trees with functional measurements. PMID:26579511

  3. Firing variability is higher than deduced from the empirical coefficient of variation.

    PubMed

    Ditlevsen, Susanne; Lansky, Petr

    2011-08-01

    A convenient and often used summary measure to quantify the firing variability in neurons is the coefficient of variation (CV), defined as the standard deviation divided by the mean. It is therefore important to find an estimator that gives reliable results from experimental data, that is, the estimator should be unbiased and have low estimation variance. When the CV is evaluated in the standard way (empirical standard deviation of interspike intervals divided by their average), then the estimator is biased, underestimating the true CV, especially if the distribution of the interspike intervals is positively skewed. Moreover, the estimator has a large variance for commonly used distributions. The aim of this letter is to quantify the bias and propose alternative estimation methods. If the distribution is assumed known or can be determined from data, parametric estimators are proposed, which not only remove the bias but also decrease the estimation errors. If no distribution is assumed and the data are very positively skewed, we propose to correct the standard estimator. When defining the corrected estimator, we simply use that it is more stable to work on the log scale for positively skewed distributions. The estimators are evaluated through simulations and applied to experimental data from olfactory receptor neurons in rats.

  4. Wheat - Its growth and disease severity as deduced from ERTS-1

    NASA Technical Reports Server (NTRS)

    Kanemasu, E. T.; Niblett, C. L.; Manges, H.; Lenhert, D.; Newman, M. A.

    1974-01-01

    The spectral reflectance of a cropped surface changes as the plant develops. An indicator of crop growth is leaf area index (ratio of green leaf area to soil area). The leaf area index, disease severity, and yield were determined for several winter wheat fields in Kansas during the 1973 growing season. Multispectral scanner (MSS) data from Earth Resources Technology Satellite-1 (ERTS-1) showed a high correlation (r greater than or equal to 0.90) between crop growth and MSS4/MSS5, and crop growth and MSS5/MSS6. Wheat disease severity and yields were significantly correlated at the 5% level with MSS4/MSS6 and with MSS4/MSS7. Further investigation is required before ERTS imagery can be routinely used detecting and estimating disease severity and yield reduction.

  5. Vertical profiles of dust and ozone in the Martian atmosphere deduced from solar occultation measurements

    NASA Astrophysics Data System (ADS)

    Blamont, J. E.; Chassefiere, E.; Goutail, J. P.; Mege, B.; Nunes-Pinharanda, M.; Souchon, G.; Krasnopolsky, V. A.; Krysko, A. A.; Moroz, V. I.

    1991-02-01

    The vertical distribution of the ozone content and of the aerosols in the Martian atmosphere at the equinox and near the equator was studied with the aid of a biaxial pointing device, a microprocessor-controlled flat mirror of elliptical shape. An upper limit of 5 x 10 to the 7th mol/cu cm for ozone was obtained above an altitude of 30 km. For the aerosols, a semiquantitative distribution has been obtained between 10 and 50 km of altitude. The scale height is nearly equal to the atmospheric scale height in the 10-20 km region where mixing seems to predominate, and falls rapidly to a thickness of about 2 km at 30 km. In 10 percent of the occultations, a stratified haze has been detected between 40 and 50 km. The particle radius of cloud constituents is estimated and optical thickness per kilometer of these hazes at peak extinction are approximated. An eddy diffusion coefficient and a mixing ratio are estimated for clouds assumed to be at equilibrium.

  6. Mean age of rifting and volcanism on Venus deduced from impact crater densities

    NASA Astrophysics Data System (ADS)

    Price, Maribeth; Suppe, John

    1994-12-01

    UNLIKE the extensively cratered highlands of the Moon and Mars, the surface of Venus does not preserve a record of heavy bombard-ment from the early history of the Solar System1-3. Those craters that are found on Venus appear to be statistically indistinguishable from a random spatial population and rarely show modification by folds, faults and lava flows1-3. Although the volcanic and tec-tonic history of Venus is still much debated2-5, there is mounting evidence for near-global resurfacing ˜300-500 Myr ago1,2,6. Moreover, it has recently been noted that the density of impact craters on large volcanic structures is less than the average crater density of the planet, suggestive of significant activity after the resurfacing event7. It is not clear, however, whether these features represent late remnants of the global event or continuing volcanism and tectonism of a still active planet. To address this question, we have used the regional variations in crater density to date volcan-oes, rifts and coronae which, based on stratigraphic evidence, clearly post-date the main resurfacing event8-11. The calculated mean ages of 70-125 Myr exclude the possibility that the majority of these features represent the final stages of the global event.

  7. A new paleointensity result deduced for the Oligocene period fromQatrani basalt, Egypt

    NASA Astrophysics Data System (ADS)

    Saleh, Ahmed; Yamamoto, Yuhji

    2016-04-01

    We have conducted paleodirection and paleointensity measurements of basalt flows from Qatrani basalt, Egypt. Published age of Qatrani basat is 25±2 Ma. Various rock magnetic analyses indicate that the main magnetic carriers of samples are one phase of pure magnetite (Ti-poor titanomagnetites), which have pseudo single domain (PSD) sizes. Directional analysis of the Oligocene basalts is very straightforward and updated mean VGPs have been calculated from the Qatrani (68N, 90E; Kappa=274; A95=1.8) which is coincide with the previous Oligocene paleomagnetic studies. The Tsunakawa-Shaw (LTD-DHT Shaw) method yielded five successful results of 12.9-17.5 μTfrom two sites, giving one acceptable site-mean paleointensityof 15.5 μT with a standard deviation of 1.8 μTat the 25±2Ma. In terms of a dipole moment, an average VDM is calculated to be 2.7×1022A m2with a standard deviation of 1.29×1022Am2. This is the first result from Egypt, and is associated with a reasonably high QPI value (Biggin and Paterson, 2015) of 5. The newly obtained VDM is indistinguishable from an average VDM of 3.55×1022Am2with a standard deviation of 0.67×1022Am2 calculated from theselected 65 site-mean Thellier paleointensity data from the latest paleointensity database, and is about third of the present geomagnetic dipole moment (˜8×1022 Am2).

  8. Deducing Weathering Processes Using Silicon Isotopes in the Ganges Alluvial Plain, India

    NASA Astrophysics Data System (ADS)

    Frings, P.; De La Rocha, C. L.; Fontorbe, G.; Chakrapani, G.; Clymans, W.; Conley, D. J.

    2014-12-01

    The Ganges Alluvial Plain ('GAP') is the sedimentary infill of the foreland basin created during Himalayan orogeny. Freshly eroded material from the Himalaya and southern cratonic tributaries is deposited into a system with long water-sediment interaction times, creating potential for further generation of river weathering fluxes. To quantify weathering processes in the GAP, 51 sites including all major tributaries were sampled in a September 2013 campaign and analysed for major and minor ions, Ge/Si ratios and δ30Si, δ13C and δ18O. Net dissolved Si (DSi) and major cation yields are 2 to 5 times lower in the GAP than the Himalaya, and at a whole basin scale approximate the global average, indicating that the plain apparently moderates the efficiency of Himalayan weathering rates. Mainstem δ30Si spans 0.81 to 1.93‰ (see figure) and gives the impression of a system buffered to moderate DSi and δ30Si. Ge/Si ratios (µmol/mol) are higher than expected in the Himalaya (>3), reflecting input of Ge-enriched water from hot springs, and decline to ~1.4 in the GAP. For the Himalayan sourced rivers, δ30Si increases with distance from the Himalayan front, and can not be explained entirely by conservative mixing with higher δ30Si peninsular and GAP streams. To a first degree, the δ30Si data suggest incorporation of Si into secondary minerals as the key fractionating process, and that this occurs both in situ during initial weathering and progressively in the GAP. Partitioning of solutes between sources is complicated in the GAP. Consistent with previous work, carbonate weathering dominates the ion fluxes, but with substantial contributions from saline/alkaline soil salts, the chlorination of wastewater and highly variable rainfall chemistry. Due to these contributions, precisely inferring the input from silicate weathering is difficult. We introduce a novel method to infer silicate-weathering rates that exploits the fractionation of Si during clay formation to account for the loss of DSi from solution.

  9. Cenozoic marine geochemistry of thallium deduced from isotopic studies of ferromanganese crusts and pelagic sediments

    USGS Publications Warehouse

    Rehkamper, M.; Frank, M.; Hein, J.R.; Halliday, A.

    2004-01-01

    Cenozoic records of Tl isotope compositions recorded by ferromanganese (Fe-Mn) crusts have been obtained. Such records are of interest because recent growth surfaces of Fe-Mn crusts display a nearly constant Tl isotope fractionation relative to seawater. The time-series data are complemented by results for bulk samples and leachates of various marine sediments. Oxic pelagic sediments and anoxic marine deposits can be distinguished by their Tl isotope compositions. Both pelagic clays and biogenic oozes are typically characterized by ??205Tl greater than +2.5, whereas anoxic sediments have ??205Tl of less than -1.5 (??205Tl is the deviation of the 205Tl/203Tl isotope ratio of a sample from NIST SRM 997 Tl in parts per 104). Leaching experiments indicate that the high ??205Tl values of oxic sediments probably reflect authigenic Fe-Mn oxyhydroxides. Time-resolved Tl isotope compositions were obtained from six Fe-Mn crusts from the Atlantic, Indian, and Pacific oceans and a number of observations indicate that these records were not biased by diagenetic alteration. Over the last 25 Myr, the data do not show isotopic variations that significantly exceed the range of Tl isotope compositions observed for surface layers of Fe-Mn crusts distributed globally (??205 Tl=+12.8??1.2). This indicates that variations in deep-ocean temperature were not recorded by Tl isotopes. The results most likely reflect a constant Tl isotope composition for seawater. The growth layers of three Fe-Mn crusts that are older than 25 Ma show a systematic increase of ??205Tl with decreasing age, from about +6 at 60-50 Ma to about +12 at 25 Ma. These trends are thought to be due to variations in the Tl isotope composition of seawater, which requires that the oceans of the early Cenozoic either had smaller output fluxes or received larger input fluxes of Tl with low ??205Tl. Larger inputs of isotopically light Tl may have been supplied by benthic fluxes from reducing sediments, rivers, and/or volcanic emanations. Alternatively, the Tl isotope trends may reflect the increasing importance of Tl fluxes to altered ocean crust through time. ?? 2004 Elsevier B.V. All rights reserved.

  10. Aromatic hydrocarbon emissions in the United States deduced from tall tower measurements

    NASA Astrophysics Data System (ADS)

    Hu, L.; Millet, D. B.; Griffis, T. J.; Tessum, C.; Travis, K.

    2013-12-01

    Aromatic compounds including benzene (C6H6), toluene (C7H8), and xylenes (C8H10) are important anthropogenic precursors of secondary organic aerosol and ground-level ozone. In addition, benzene has been classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC). However, their emissions remain poorly constrained. Here we present a full year (2011) of continuous aromatic hydrocarbon measurements by PTR-MS at the University of Minnesota tall tower Tracer Gas Observatory (KCMP tall tower, 244 m a.g.l, 44.689°N, 93.073°W). We interpret the tall tower data with a 0.5° ×0.667° GEOS-Chem nested grid simulation to constrain US sources of benzene, toluene, and xylenes. The tall tower observations reveal a clear high bias in the model, with model: measurement slopes of 1.8, 5.3, and 2.9 for benzene, toluene, and xylenes, respectively. The high bias reflects an overestimate of aromatic hydrocarbon emissions in the model, which are based on the RETRO emission Inventory. In this work, we employ a Bayesian inversion to interpret the KCMP tall tower measurements in terms of quantitative constraints on US aromatic sources and the importance of sectors such as on-road transportation, waste treatment and disposal, solvent use, etc. We discuss our findings relative to other emission estimates (e.g., the EPA NEI) and in terms of their implications for air quality modeling.

  11. Strain patterns deduced from high-resolution airborne surveys in Namibia

    NASA Astrophysics Data System (ADS)

    Ledru, P.; Garoeb, H.; Kamati, T.; Wackerle, R.; Martelet, G.; Truffert, C.

    2003-04-01

    High-resolution aeromagnetic dataset have been acquired in the framework of a long-term programme that aims at a complete coverage of Namibia in 2008. More than half of the territory has been already flown with a 200m line spacing and 2500m tie lines, at a terrain clearance of 80 to 100 m. The contribution of the interpretation of these datasets to the definition of the strain pattern is presented. The first test zone concerns an orogenic zone, the southern zone of the Damara belt, south of Rehoboth. The different maps of the gradients of the magnetic field reduced to the pole have been used in order to define the regional strain pattern. Following up a limited field work that has characterized the geometry and kinematics of the main discontinuities, it has been shown that this zone is characterized by one single orogenic phase marked by a reverse crustal-scale shear zone system (with a down-dip stretching direction) to which regional-scale NE-SW folding is related. The anastomosed shear zone system is thus traced along more than 200 km. A provisional foliation trajectory map can be drawn, transecting the bedding in the hinges of the folds within sediments and underlined by a magnetite-rich veinlet network within the pre-tectonic granites. Moreover, this strain pattern has been extended under the superficial deposits that cover the eastern half of the studied area. Automatic structural analysis has been performed using Geosoft and ArcView/SynArc. Thus, source edge detection, search of ridges and curvature analysis provide qualitative analysis while the search of discontinuities along the horizontal gradients of the magnetic field using SynArc produces a very satisfactory statistical approach of the structural pattern. A second test zone illustrates an extensional tectonic context, i.e. the northern termination of the NNE-SSW Mesozoic aborted rift, developed synchronously with the opening of the Southern Atlantic ocean at the Jurassic-Cretaceous boundary. A dense dolerite dyke network, poorly outcropping in this zone, is revealed. Its mapping has been performed mainly by using the ridges of the first vertical derivative of the magnetic field reduced to the pole. Up to 4 generations of dykes are differentiated, the apparent chronology suggesting a change from an initial rift to a strike slip environment, characterized by a sinistral component along the main NNE-SSW tectonic line. The magnetic maps also reveal that the emplacement of the alkaline ring complexes postdates this dolerite dyke network.

  12. Students' Dilemmas in Reaction Stoichiometry Problem Solving: Deducing the Limiting Reagent in Chemical Reactions

    ERIC Educational Resources Information Center

    Chandrasegaran, A. L.; Treagust, David F.; Waldrip, Bruce G.; Chandrasegaran, Antonia

    2009-01-01

    A qualitative case study was conducted to investigate the understanding of the limiting reagent concept and the strategies used by five Year 11 students when solving four reaction stoichiometry problems. Students' written problem-solving strategies were studied using the think-aloud protocol during problem-solving, and retrospective verbalisations…

  13. The mechanism of the acclimation of Nannochloropsis oceanica to freshwater deduced from its transcriptome profiles

    NASA Astrophysics Data System (ADS)

    Guo, Li; Yang, Guanpin

    2015-10-01

    In this study, we compared the transcriptomes of Nannochloropsis oceanica cultured in f/2 medium prepared with sea-water and freshwater, respectively, aiming to understand the acclimation mechanism of this alga to freshwater. Differentially expressed genes were mainly assigned to the degradation of cell components, ion transportation, and ribosomal biogenesis. These findings indicate that the algal cells degrade its components (mainly amino acids and fatty acids) to yield excessive energy (ATP) to maintain cellular ion (mainly K+ and Ca2+) homeostasis, while the depletion of amino acids and ATP, and the reduction of ribosomes attenuate the protein translation and finally slow down the cell growth.

  14. How historical seismicity in oceans can be deduced from sailors' testimonies and related to modern tectonics

    NASA Astrophysics Data System (ADS)

    Legrand, Denis; Rouland, Daniel; Cisternas, Armando; Streng, Daniel; Gir, Roopa; Souriau, Annie

    2016-04-01

    Before seismological catalogs were routinely produced, seafarers experienced major seismic events at sea that were documented in their logs. This article analyzes some of these old records - mostly from eighteenth and nineteenth centuries - in the context of plate tectonics. Large shocks that were felt on ships are related either to earthquakes, sub-marine volcanic eruptions, or to sub-marine sliding of rocks and/or sediments. We analyze various related parameters such as the location and size of the shaking, the duration of the shock, and the associated noise. A total of 396 observations have been retained for this study, mostly located in the Atlantic Ocean, reflecting its intense maritime traffic during the period of interest. Some of the detailed accounts allow us to clearly identify the nature of the shocks, including a possible interpretation in terms of focal mechanism. Our results, when compared to historical catalogs, reveal many previously undetected large events. Macroseismic results for a few large historical events occurring near the coasts confirm the validity of our approach, but also reveal its limitations. The good locations of most of the events allow us to relate them to plate boundaries. The Romanche transform zone has deserved particular interest due to the large number of related testimonies. This study particularly illustrates that historical seismicity may be applied to oceans. The collected testimonies also show how impressive and dangerous these large earthquakes at sea are, despite the absence of S-waves.

  15. Eastern Asian Emissions of Anthropogenic Halocarbons Deduced from Aircraft Concentration Data

    NASA Technical Reports Server (NTRS)

    Palmer, Paul I.; Jacob, Daniel J.; Mickle, Loretta, J.; Blake, Donald R.; Sachse, Glen W.; Fuelberg, Henry E.; Kiley, Christopher M.

    2003-01-01

    The Montreal Protocol restricts production of ozone-depleting halocarbons worldwide. Enforcement of the protocol has relied mainly on annual government statistics of production and consumption of these compounds (bottom-up approach). We show here that aircraft observations of ha1ocarbon:CO enhancement ratios on regional to continental scales can be used to infer halocarbon emissions, providing independent verification of the bottom-up approach. We apply this topdown approach to aircraft observations of Asian outflow &om the TRACE-P mission over the western Pacific (March-April 2001) and derive emissions from eastern Asia (China, Japan, and Korea). We derive an eastern Asian carbon tetrachloride (CCl4) source of 21.5 Gg yr(sup -1), several-fold larger than previous estimates and amounting to -30% of the global budget for this gas. Our emission estimate for CFC-11 from eastern Asia is 50% higher than inventories derived from manufacturing records. Our emission estimates for methyl chloroform (CH3CC13) and CFC-12 are in agreement with existing inventories. For halon 1211 we find only a strong local source originating from the Shanghai area. Our emission estimates for the above gases result in a approximately equal to 40% increase in the ozone depletion potential (ODP) of Asian emissions relative to previous estimates, corresponding to a approximately equal to 10% global increase in ODP.

  16. Variability of carbonate diagenesis in equatorial Pacific sediments deduced from radiogenic and stable Sr isotopes

    NASA Astrophysics Data System (ADS)

    Voigt, Janett; Hathorne, Ed C.; Frank, Martin; Vollstaedt, Hauke; Eisenhauer, Anton

    2015-01-01

    The recrystallisation (dissolution-precipitation) of carbonate sediments has been successfully modelled to explain profiles of pore water Sr concentration and radiogenic Sr isotope composition at different locations of the global ocean. However, there have been few systematic studies trying to better understand the relative importance of factors influencing the variability of carbonate recrystallisation. Here we present results from a multi-component study of recrystallisation in sediments from the Integrated Ocean Drilling Program (IODP) Expedition 320/321 Pacific Equatorial Age Transect (PEAT), where sediments of similar initial composition have been subjected to different diagenetic histories. The PEAT sites investigated exhibit variable pore water Sr concentrations gradients with the largest gradients in the youngest sites. Radiogenic Sr isotopes suggest recrystallisation was relative rapid, consistent with modelling of other sediment columns, as the 87Sr/86Sr ratios are indistinguishable (within 2σ uncertainties) from contemporaneous seawater 87Sr/86Sr ratios. Bulk carbonate leachates and associated pore waters of Site U1336 have lower 87Sr/86Sr ratios than contemporaneous seawater in sediments older than 20.2 Ma most likely resulting from the upward diffusion of Sr from older recrystallised carbonates. It seems that recrystallisation at Site U1336 may still be on-going at depths below 102.5 rmcd (revised metres composite depth) suggesting a late phase of recrystallisation. Furthermore, the lower Sr/Ca ratios of bulk carbonates of Site U1336 compared to the other PEAT sites suggest more extensive diagenetic alteration as less Sr is incorporated into secondary calcite. Compared to the other PEAT sites, U1336 has an inferred greater thermal gradient and a higher carbonate content. The enhanced thermal gradient seems to have made these sediments more reactive and enhanced recrystallisation. In this study we investigate stable Sr isotopes from carbonate-rich deep sea sediments for the first time. Pore water δ88/86Sr increases with depth (from 0.428‰ to values reaching up to 0.700‰) at Site U1336 documenting an isotope fractionation process during recrystallisation. Secondary calcite preferentially incorporates the lighter Sr isotope (86Sr) leaving pore waters isotopically heavy. The δ88/86Sr values of the carbonates themselves show more uniform values with no detectable change with depth. Carbonates have a much higher Sr content and total Sr inventory than the pore waters meaning pore waters are much more sensitive to fractionation processes than the carbonates. The δ88/86Sr results indicate that pore water stable Sr isotopes have the potential to indicate the recrystallisation of carbonate sediments.

  17. Inner ear anatomy is a proxy for deducing auditory capability and behaviour in reptiles and birds

    PubMed Central

    Walsh, Stig A.; Barrett, Paul M.; Milner, Angela C.; Manley, Geoffrey; Witmer, Lawrence M.

    2009-01-01

    Inferences of hearing capabilities and audition-related behaviours in extinct reptiles and birds have previously been based on comparing cochlear duct dimensions with those of living species. However, the relationship between inner-ear bony anatomy and hearing ability or vocalization has never been tested rigorously in extant or fossil taxa. Here, micro-computed tomographic analysis is used to investigate whether simple endosseous cochlear duct (ECD) measurements can be fitted to models of hearing sensitivity, vocalization, sociality and environmental preference in 59 extant reptile and bird species, selected based on their vocalization ability. Length, rostrocaudal/mediolateral width and volume measurements were taken from ECD virtual endocasts and scaled to basicranial length. Multiple regression of these data with measures of hearing sensitivity, vocal complexity, sociality and environmental preference recovered positive correlations between ECD length and hearing range/mean frequency, vocal complexity, the behavioural traits of pair bonding and living in large aggregations, and a negative correlation between ECD length/rostrocaudal width and aquatic environments. No other dimensions correlated with these variables. Our results suggest that ECD length can be used to predict mean hearing frequency and range in fossil taxa, and that this measure may also predict vocal complexity and large group sociality given comprehensive datasets. PMID:19141427

  18. The age of the Veritas asteroid family deduced by chaotic chronology

    NASA Astrophysics Data System (ADS)

    Milani, Andrea; Farinella, Paolo

    1994-07-01

    ASTEROID families are groups of objects produced in disruptive collisions of a parent body. Although family members are widely dispersed in real space, they cluster in the parameter space defined by their so-called proper elements, and can thus be distinguished from the background asteroid population1-3. For most asteroids, these parameters are very close to being invariants of motion and families are still apparent billions of years after their formation4'5. But these parameters undergo chaotic diffusion, and in some cases the rate of diffusion might be large enough that a family member exits from the region of proper-element space occupied by the family after a characteristic time which is shorter than the lifetime of the Solar System. In this case, the characteristic time should provide an approximate upper bound to the age of the family. Here we use this 'chaotic chronology' method to estimate the lifetime of the unusually compact Veritas family. Calculations of the evolu-tion of the proper elements of the family show that two members (including the largest, 490 Veritas) wander outside the borders of the family on a timescale of about 50 Myr, indicating that the family has an age of less than this.

  19. Genetic oscillation deduced from Hopf bifurcation in a genetic regulatory network with delays.

    PubMed

    Xiao, Min; Cao, Jinde

    2008-09-01

    To understand how a gene regulatory network functioning as an oscillator is built, a genetic regulatory network with two transcriptional delays is investigated. We show by mathematical analysis and simulation that autorepression of mRNA and protein can provide a mechanism for the intracellular oscillator. Based on the linear stability approach and bifurcation theory, sufficient conditions for the oscillation of the genetic networks are derived, and critical values of Hopf bifurcation are assessed. In particular, the genetic network can exhibit Hopf bifurcation(oscillation appears) as the sum of delays or transcriptional rate passes through some critical values. Moreover, the robustness of amplitudes against change in delay can also be obtained from the delayed genetic network; period of oscillation increases with the total time delay in an almost linear way. While it is exactly opposite for transcriptional rate, the amplitude of oscillations always increases as the transcriptional rate increases; the robustness of period against change in the transcriptional rate occurs. Some simple genetic regulatory networks are used to study the impact of delays and transcriptional rate on the system dynamics where there are delays.

  20. Glycan specificity of myelin-associated glycoprotein and sialoadhesin deduced from interactions with synthetic oligosaccharides.

    PubMed

    Strenge, K; Schauer, R; Bovin, N; Hasegawa, A; Ishida, H; Kiso, M; Kelm, S

    1998-12-01

    Myelin-associated glycoprotein (MAG) and sialoadhesin (Sn) bind to sialylated glycans on cell surfaces and are thought to be involved in cell-cell interactions. In order to investigate how the interactions of these proteins are influenced by the glycan structure, we compared the inhibitory potencies of different synthetic monovalent oligosaccharides and polyvalent polyacrylamide derivatives. Using oligosaccharides with modifications in the sialic acid, galactose or N-acetylglucosamine moieties, we could demonstrate that both MAG and Sn bind with high preference to alpha2,3-linked sialic acid and interact at least with the three terminal monosaccharide units. For MAG, contacts with even more distant monosaccharides are likely, since pentasaccharides are bound better than trisaccharides. Also, an additional sialic acid at position six of the third-terminal monosaccharide unit enhances binding to MAG, whereas it does not influence binding to Sn significantly. Modifications of the sialic acid glycerol side chain demonstrated that the hydroxy groups at positions 8 and 9 are required for binding to both proteins. Surprisingly, MAG binds 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid significantly better than N-acetylneuraminic acid, whereas Sn prefers the latter structure. These results indicate that the interactions of MAG and Sn are mainly with sialic acid and that additional contacts with the subterminal galactose and N-acetylglucosamine residues also contribute to the binding strength, although to a lesser degree. PMID:9874234

  1. Grain Properties of Comet C/1995 O1 (Hale-Bopp) Deduced Through Computational Techniques

    NASA Technical Reports Server (NTRS)

    Harker, David E.; Wooden, Diane H.; Woodward, Charles E.; Lisse, Carey M.

    2001-01-01

    We present the computational analysis of the 7.6 - 13.2 micrometer infrared (IR) spectrophotometry (R approximately equal to 120) of comet C/1995 O1 (Hale-Bopp) in conjunction with concurrent observations which extend the spectral energy distribution from the near-infrared to far-infrared wavelengths. The observations include temporal epochs pre-perihelion, (1996 October UT and 1997 February UT), near perihelion (1997 April UT), and postperihelion (1997 June UT). Through the computational modeling of small amorphous carbon, and crystalline and amorphous silicate grains in Hale-Bopp's coma, we find that as the comet approached perihelion, the grain size distribution (the Hanner modified power law) steepened (N = 3.4 pre-perihelion, to N = 3.7 near and post-perihelion) along with an increase in the fractal porosity of larger (greater than 1 micrometer) grains. The peak of the grain size distribution remained constant (ap = 0.2 micrometer) at each epoch. We attribute the emergence of the 9.3 micrometer peak near perihelion to crystalline orthopyroxeno grains released from inside the nucleus. Crystalline silicates (olivine and orthopyroxene) make up about 30% (by mass) of the submicron sized (less than 1 micrometer) dust grains in Hale-Bopp's coma during each epoch.

  2. Paleoclimate variability during the Blake geomagnetic excursion (MIS 5d) deduced from a speleothem record

    NASA Astrophysics Data System (ADS)

    Rossi, Carlos; Mertz-Kraus, Regina; Osete, María-Luisa

    2014-10-01

    To evaluate possible connections between climate and the Earth's magnetic field, we examine paleoclimate proxies in a stalagmite (PA-8) recording the Blake excursion (˜112-˜116.4 ka) from Cobre cave (N Spain). Trace element, δ13C, δ18O, δ234U, fluorescent lamination, growth rate, and paleomagnetic records were synchronized using a floating lamina-counted chronology constrained by U-Th dates, providing a high-resolution multi-proxy paleoclimate record for MIS 5d. The alpine cave setting and the combination of proxies contributed to improve the confidence of the paleoclimatic interpretation. Periods of relatively warm and humid climate likely favored forest development and resulted in high speleothem growth rates, arguably annual fluorescent laminae, low δ13C and [Mg], and increased [Sr] and [Ba]. Colder periods limited soil activity and drip water availability, leading to reduced speleothem growth, poor development of fluorescent lamination, enhanced water-rock interaction leading to increased [Mg], δ13C, and δ234U, and episodic flooding. In the coldest and driest period recorded, evaporation caused simultaneous 18O and 13C enrichments and perturbed the trace element patterns. The Blake took place in a relatively warm interestadial at the inception of the Last Glacial period, but during a global cooling trend recorded in PA-8 by an overall decrease of δ18O and growth rate and increasing [Mg]. That trend culminated in the cessation of growth between ˜112 and ˜101 ka likely due to the onset of local glaciation correlated with Greenland stadial 25. That trend is consistent with a link between low geomagnetic intensity and climate cooling, but it does not prove it. Shorter term changes in relative paleointensity (RPI) relate to climate changes recorded in PA-8, particularly a prominent RPI low from ˜114.5 to ˜113 ka coincident with a significant cooling indicated by all proxy records, suggesting a link between geomagnetic intensity and climate at millennial time scales. Although the reliability of such inference is limited by the inferior resolution of the paleomagnetic data and a possible contamination of the RPI data by unaccounted changes in magnetite concentration, the agreement of those data with the marine record of cosmogenic Be suggests that the RPI record of PA-8 may reflect truly geomagnetic intensity variations.

  3. Millennial-scale hard rock erosion rates deduced from luminescence-depth profiles

    NASA Astrophysics Data System (ADS)

    Sohbati, R.; Liu, J.; Murray, A. S.; Jain, M.; Pederson, J. L.; Guralnik, B.; Egholm, D. L.; Gupta, S.

    2015-12-01

    Optically stimulated luminescence (OSL) is a well-established Quaternary dating method that is conventionally used to determine the time when sedimentary grains were last exposed to daylight. Recently, a very different approach to this concept has helped develop a new technique to estimate the length of time a rock surface was exposed to daylight. When a rock surface is first exposed to daylight the charge population (and so the latent luminescence signal) trapped in its constituent minerals (e.g. quartz and feldspar) starts to decrease. This charge had accumulated due to previous exposure to natural ionizing radiation. As the surface is exposed to light for longer periods, the latent luminescence signal is reduced farther into the rock. In a rock surface which has been exposed to light for a prolonged period (decades to millennia), the remaining luminescence will be zero (fully bleached) at the surface and then increase, initially exponentially, before approaching saturation at a depth where charge detrapping due to light penetration is negligible compared to the rate of charge trapping due to the environmental dose rate. By modelling the characteristic shape of luminescence resetting with depth into rock surfaces, Sohbati et al. (2012) proposed a new surface-exposure dating technique based on OSL. Here we further develop the current model to include the effect of erosion rate on luminescence-depth profiles. By fitting the model to local known-age calibration samples, we first determine the site-specific resetting rates of the luminescence signal at rock surfaces. We then use the calibration values in a numerical model to derive the steady-state erosion rate for rocks of different mineralogy and different geological settings. The preliminary erosion rates obtained from glacial and landslide granite boulders from the Chinese Pamir Plateau are ~1 mm.ka-1, whereas active streambeds of Permian sandstone in the Grabens district of Canyonlands National Park, Utah, are eroding at rates of >10 mm.ka-1, consistent with the existing denudation rates derived from cosmogenic nuclides.

  4. Mass flux in the ecliptic plane and near the Sun deduced from Doppler scintillation

    NASA Technical Reports Server (NTRS)

    Woo, Richard; Gazis, Paul R.

    1994-01-01

    During the late declining phase of the solar cycle, the tilt of the solar magnetic dipole with respect to the Sun's rotation axis leads to large-scale organization of the solar wind, such that alternating regions of high- and low-speed solar wind are observed in the ecliptic plane. In this paper, we use Doppler scintillation measurements to investigate mass flux of these two types of solar wind in the ecliptic plane and inside 0.3 AU, where in situ measurements have not been possible. To the extent that Doppler scintillation reflects mass flux, we find that mass flux in high-speed streams: (1) is lower (by a factor of approximately 2.2) than the mass flux of the average solar wind in the heliocentric distance range of 0.3-0.5 AU; (2) is lower still (by as much as a factor of about 4) than the mass flux of the slow solar wind associated with the streamer belt; and (3) appears to grow with heliocentric distance. These Doppler scintillation results are consistent with the equator to pole decrease in mass flux observed in earlier spectral broadening measurements, and with trends and differences between high- and low-speed solar wind observed by in situ measurements in the range of 0.3-0.1 AU. The mass flux results suggest that the solar wind flow in high-speed streams is convergent towards the ecliptic near the Sun, becoming less convergent and approaching radial with increasing heliocentric distance beyond 0.3 AU. The variability of mass flux observed within equatorial and polar high-speed streams close to the Sun is strikingly low. This low variability implies that, as Ulysses currently ascends to higher latitudes and spends more time in the south polar high-speed stream after crossing the heliocentric current sheet, it can expect to observe a marked decrease in variations of both mass flux and solar wind speed, a trend that appears to have started already.

  5. Structure-property relationships in major ampullate spider silk as deduced from polarized FTIR spectroscopy.

    PubMed

    Papadopoulos, P; Sölter, J; Kremer, F

    2007-10-01

    Polarized Fourier Transform Infrared (FTIR) spectroscopy is employed to study structure-property relationships in major ampullate spider silk being exposed to an external mechanical strain. From the measured infrared dichroism of aminoacid-residue - specific bands the molecular order parameter, the frequency width at half-maximum (FWHM) and the spectral position of the absorption maximum are determined in dependence on the external strain. For the highly ordered alanine-rich beta sheets a change in the vibrational potential is found for macroscopic strains as low as a few percent. It can be quantitatively described by a quantum-mechanical approach in which the mechanical strain is treated as a weak external perturbation. The immediate microscopic response to the external field proves that beta -sheeted crystals are tightly interconnected by pre-stretched chains as suggested recently (Y. Liu et al., Nat. Mater. 4, 901 (2005)).

  6. Near-zero growth kinetics of Pseudomonas putida deduced from proteomic analysis.

    PubMed

    Panikov, Nicolai S; Mandalakis, Manolis; Dai, Shujia; Mulcahy, Lawrence R; Fowle, William; Garrett, Wendy S; Karger, Barry L

    2015-01-01

    Intensive microbial growth typically observed in laboratory rarely occurs in nature. Because of severe nutrient deficiency, natural populations exhibit near-zero growth (NZG). There is a long-standing controversy about sustained NZG, specifically whether there is a minimum growth rate below which cells die or whether cells enter a non-growing maintenance state. Using chemostat with cell retention (CCR) of Pseudomonas putida, we resolve this controversy and show that under NZG conditions, bacteria differentiate into growing and VBNC (viable but not non-culturable) forms, the latter preserving measurable catabolic activity. The proliferating cells attained a steady state, their slow growth balanced by VBNC production. Proteomic analysis revealed upregulated (transporters, stress response, self-degrading enzymes and extracellular polymers) and downregulated (ribosomal, chemotactic and primary biosynthetic enzymes) proteins in the CCR versus batch culture. Based on these profiles, we identified intracellular processes associated with NZG and generated a mathematical model that simulated the observations. We conclude that NZG requires controlled partial self-digestion and deep reconfiguration of the metabolic machinery that results in the biosynthesis of new products and development of broad stress resistance. CCR allows efficient on-line control of NZG including VBNC production. A well-nuanced understanding of NZG is important to understand microbial processes in situ and for optimal design of environmental technologies.

  7. Average depth of blood vessels in skin and lesions deduced by optical fiber spectroscopy

    NASA Astrophysics Data System (ADS)

    Jacques, Steven L.; Saidi, Iyad S.; Tittel, Frank K.

    1994-09-01

    The average depth of blood vessels in a cutaneous site, either normal or diseased, can be specified by a simple rapid noninvasive optical measurement. An optical fiber spectrophotometer delivers white light via optical fibers to a skin site. The light reflected by tissue scattering and successfully collected by optical fibers is carried to a diode array spectrophotometer for spectral analysis. The reflectance spectrum is analyzed to specify the component of the optical density (OD) spectrum which is attributed to the cutaneous blood. Then the ratio of the OD420 nm/OD585 nm provides a quantitative indication of the average depth of the blood in the skin site. The purple light (420 nm) less easily penetrates the skin to sample the cutaneous blood content than does the yellow light (585 nm). The calibration of the measurement was accomplished by Monte Carlo simulations of measurements on skin with a layer of blood at various depths. In a study of 47 neonates, the amount of blood content ranged from 4 - 12 mg hemoglobin/g tissue (equivalent to 0.8 - 2.4% of the skin volume being whole blood), and the average depth of blood ranged from 250 - 425 micrometers .

  8. Diurnal Variation of Hydration from Lunar Soil Deduced from Albedo Proton Radiation

    NASA Astrophysics Data System (ADS)

    Schwadron, N. A.; Wilson, J. K.; Looper, M.; Jordan, A. P.; Spence, H. E.; Farrell, W. M.; Petro, N.; Stubbs, T. J.; Pieters, C.; Townsend, L. W.

    2016-11-01

    We show first results from CRaTER comparing horizon to nadir observations in morning and evening sectors. Significant differences in the ratio of horizon to nadir protons suggests migration of volatiles may cause observed variations.

  9. Using Measurements of Fill Factor at High Irradiance to Deduce Heterobarrier Band Offsets: Preprint

    SciTech Connect

    Olson, J. M.; Steiner, M. A.; Kanevce, A.

    2011-07-01

    Using a 2D device simulation tool, we examine the high irradiance behavior of a single junction, GaAs concentrator cell as a function of the doping in the back surface confinement layer. The confinement layer is designed to be a barrier for both holes and electrons in the base of the solar cell. For a p-type base we show that the FF of the cell at high concentrations is a strong function of both the magnitude of the valence band offset and the doping level in the barrier. In short, for a given valence band offset (VBO), there is a critical barrier doping, below which the FF drops rapidly with lower doping. This behavior is confirmed experimentally for a GaInP/GaAs double heterostructure solar cell where the critical doping concentration (at 500 suns) in the back surface confinement layer is ~1e18 cm-3 for a VBO of 300 meV.

  10. Properties of rainfall in a tropical volcanic island deduced from UHF wind profiler measurements

    NASA Astrophysics Data System (ADS)

    Réchou, A.; Narayana Rao, T.; Bousquet, O.; Plu, M.; Decoupes, R.

    2014-02-01

    The microphysical properties of rainfall at the island of Réunion are analysed and quantified according to one year of wind profiler observations collected at Saint-Denis international airport. The statistical analysis clearly shows important differences in rain vertical profiles as a function of the seasons. During the dry season, the vertical structure of precipitation is driven by trade wind and boundary-layer inversions, both of which limit the vertical extension of the clouds. The rain rate is lower than 2.5 mm h-1 throughout the lower part of the troposphere (about 2 km) and decreases in the higher altitudes. During the moist season, the average rain rate is around 5 mm h-1 and nearly uniform from the ground up to 4 km. The dynamical and microphysical properties (including drop size distributions) of four distinct rainfall events are also investigated through the analysis of four case studies representative of the variety of rain events occurring on Réunion: summer deep convection, northerly-to-northeasterly flow atmospheric pattern, cold front and winter depression embedded in trade winds. Radar-derived rain parameters are in good agreement with those obtained from collocated rain gauge observations in all cases, which demonstrates that accurate qualitative and quantitative analysis can be inferred from wind profiler data. Fluxes of kinetic energy are also estimated from wind profiler observations in order to evaluate the impact of rainfall on soil erosion. Results show that horizontal kinetic energy fluxes are systematically one order of magnitude higher than vertical kinetic energy fluxes. A simple relationship between the reflectivity factor and vertical kinetic energy fluxes is proposed based on the results of the four case studies.

  11. Multiquasiparticle configuration effects deduced from the very high frequency discrete lines spectroscopy of /sup 165/Yb

    SciTech Connect

    Schuck, C.; Bendjallah, N.; Diamond, R.M.; Ellis-Akovali, Y.; Lindenberg, K.H.; Newton, J.O.; Shih, S.; Stephens, F.S.; Garret, J.D.; Herskind, B.

    1982-01-01

    New experimental data are presented for /sup 165/Yb in which three already known rotational bands are extended up to very high angular frequencies. We do not observe, below h-bar omega/sub c/ approx. 0.45 MeV in any of these three bands the second discontinuity occuring for h-bar omega/sub c/ approx. 0.42 MeV in N = 90 nuclei. Furthermore, we observe in these three sequences a dealignment of high enough amplitude that it cannot be explained in terms of a single quasi-neutron configuration, and must then be due to a collective effect. A gradual decrease of the neutron pairing with increasing angular frequencies is suggested.

  12. Light elements burning reaction rates at stellar temperatures as deduced by the Trojan Horse measurements

    SciTech Connect

    Lamia, L.; Spitaleri, C.; La Cognata, M.; Palmerini, S.; Sergi, M. L.; Puglia, S. M. R.

    2015-02-24

    Experimental nuclear astrophysics aims at determining the reaction rates for astrophysically relevant reactions at their Gamow energies. For charged-particle induced reactions, the access to these energies is usually hindered, in direct measurements, by the presence of the Coulomb barrier between the interacting particles or by electron screening effects, which make hard the determination of the bare-nucleus S(E)-factor of interest for astrophysical codes. The use of the Trojan Horse Method (THM) appears as one of the most suitable tools for investigating nuclear processes of interest for astrophysics. Here, in view of the recent TH measurements, the main destruction channels for deuterium ({sup 2}H), for the two lithium {sup 6,7}Li isotopes, for the {sup 9}Be and the one for the two boron {sup 10,11}B isotopes will be discussed.

  13. Human impacts on groundwater flow and contamination deduced by multiple isotopes in Seoul City, South Korea.

    PubMed

    Hosono, Takahiro; Ikawa, Reo; Shimada, Jun; Nakano, Takanori; Saito, Mitsuyo; Onodera, Shin-ichi; Lee, Kang-Kun; Taniguchi, Makoto

    2009-04-15

    The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes (deltaD, T, delta15N, delta18O, delta34S, and 87Sr/86Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes (deltaD and delta18O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The delta34S and delta15N of SO4(2-) and NO3- data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO4(2-) (>30 ppm as SO4(2-)) and NO3- (>20 ppm as NO3-) of groundwater. The 87Sr/86Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas.

  14. High-frequency Earth rotation variations deduced from altimetry-based ocean tides

    NASA Astrophysics Data System (ADS)

    Madzak, Matthias; Schindelegger, Michael; Böhm, Johannes; Bosch, Wolfgang; Hagedoorn, Jan

    2016-11-01

    A model of diurnal and semi-diurnal variations in Earth rotation parameters (ERP) is constructed based on altimetry-measured tidal heights from a multi-mission empirical ocean tide solution. Barotropic currents contributing to relative angular momentum changes are estimated for nine major tides in a global inversion algorithm that solves the two-dimensional momentum equations on a regular 0.5° grid with a heavily weighted continuity constraint. The influence of 19 minor tides is accounted for by linear admittance interpolation of ocean tidal angular momentum, although the assumption of smooth admittance variations with frequency appears to be a doubtful concept for semi-diurnal mass terms in particular. A validation of the newly derived model based on post-fit corrections to polar motion and universal time (Δ UT1) from the analysis of Very Long Baseline Interferometry (VLBI) observations shows a variance reduction for semi-diurnal Δ UT1 residuals that is significant at the 0.05 level with respect to the conventional ERP model. Improvements are also evident for the explicitly modeled K_1, Q_1, and K_2 tides in individual ERP components, but large residuals of more than 15 μ as remain at the principal lunar frequencies of O_1 and M_2. We attribute these shortcomings to uncertainties in the inverted relative angular momentum changes and, to a minor extent, to violation of mass conservation in the empirical ocean tide solution. Further dedicated hydrodynamic modeling efforts of these anomalous constituents are required to meet the accuracy standards of modern space geodesy.

  15. Molecular evolution of arthropod color vision deduced from multiple opsin genes of jumping spiders.

    PubMed

    Koyanagi, Mitsumasa; Nagata, Takashi; Katoh, Kazutaka; Yamashita, Shigeki; Tokunaga, Fumio

    2008-02-01

    Among terrestrial animals, only vertebrates and arthropods possess wavelength-discrimination ability, so-called "color vision". For color vision to exist, multiple opsins which encode visual pigments sensitive to different wavelengths of light are required. While the molecular evolution of opsins in vertebrates has been well investigated, that in arthropods remains to be elucidated. This is mainly due to poor information about the opsin genes of non-insect arthropods. To obtain an overview of the evolution of color vision in Arthropoda, we isolated three kinds of opsins, Rh1, Rh2, and Rh3, from two jumping spider species, Hasarius adansoni and Plexippus paykulli. These spiders belong to Chelicerata, one of the most distant groups from Hexapoda (insects), and have color vision as do insects. Phylogenetic analyses of jumping spider opsins revealed a birth and death process of color vision evolution in the arthropod lineage. Phylogenetic positions of jumping spider opsins revealed that at least three opsins had already existed before the Chelicerata-Pancrustacea split. In addition, sequence comparison between jumping spider Rh3 and the shorter wavelength-sensitive opsins of insects predicted that an opsin of the ancestral arthropod had the lysine residue responsible for UV sensitivity. These results strongly suggest that the ancestral arthropod had at least trichromatic vision with a UV pigment and two visible pigments. Thereafter, in each pancrustacean and chelicerate lineage, the opsin repertoire was reconstructed by gene losses, gene duplications, and function-altering amino acid substitutions, leading to evolution of color vision. PMID:18217181

  16. Total Vertical Offset for the Beichuan Fault (Longmen Shan, Sichuan, China) Deduced from Metamorphic Minerals

    NASA Astrophysics Data System (ADS)

    Airaghi, L.; de Sigoyer, J.; Vidal, O.; Lanari, P.; Tan, X. B.; Xu, X.; Guillot, S.

    2015-12-01

    The paradox of high topography but low convergence rates in the Longmen Shan mountain belt, at the eastern margin of Tibetan plateau (Sichuan, China) leaded to an underestimation of the seismic hazard prior to the Wenchuan earthquake Mw 7.9 (2008). The rupture affected the crustal Beichuan fault, with both thrusting and dextral slide slip components. This fault is responsible for the exhumation of the basement over Triassic sediments. Several paleoseismological studies have well constrained the Quaternary activity of this fault, and thermochronological data show a rapid exhumation starting from Oligocene. The total offset of the Beichuan fault remains unknown. Samples collected in the hanging wall of the Beichuan fault, yield stable white mica, chlorite, epidote and quartz. Chemical and thermobarometric analyses of metamorphic minerals yield metamorphic peak conditions at 300±50°C and 7-8 kbar. Such P,T conditions suggest burial to 18-20 km depth, and represent the maximum vertical offset of the Beichuan fault. Comparison of results from distant sampled sites along the Beichuan fault reveals the spatial continuity of this offset along the Beichuan fault. The attainment of peak pressure conditions will be dated using in-situ laser ablation 40Ar/39Ar dating of the metamorphic micas. This will help constrain the onset of Beichuan fault activation, which corresponds to the onset of thick skin deformation in the Longmen Shan. [CW1]I deleted all this stuff below because I thought it was too much information for a conference abstract - but you do have space to put it back.

  17. Distribution of buried hydrothermal alteration deduced from high-resolution magnetic surveys in Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Bouligand, Claire; Glen, Jonathan M. G.; Blakely, Richard J.

    2014-04-01

    Yellowstone National Park (YNP) displays numerous and extensive hydrothermal features. Although hydrothermal alteration in YNP has been extensively studied, the volume, geometry, and type of rock alteration at depth remain poorly constrained. In this study, we use high-resolution airborne and ground magnetic surveys and measurements of remanent and induced magnetization of field and drill core samples to provide constraints on the geometry of hydrothermal alteration within the subsurface of three thermal areas in YNP (Firehole River, Smoke Jumper Hot Springs, and Norris Geyser Basin). We observe that hydrothermal zones from both liquid- and vapor-dominated systems coincide with magnetic lows observed in aeromagnetic surveys and with a decrease of the amplitude of short-wavelength anomalies seen in ground magnetic surveys. This suggests a strong demagnetization of both the shallow and deep substratum within these areas associated with the removal of magnetic minerals by hydrothermal alteration processes. Such demagnetization is confirmed by measurements of rock samples from hydrothermal areas which display significantly decreased total magnetization. A pronounced negative anomaly is observed over the Lone Star Geyser and suggests a significant demagnetization of the substratum associated with areas displaying large-scale fluid flow. The ground and airborne magnetic surveys are used to evaluate the distribution of magnetization in the subsurface. This study shows that significant demagnetization occurs over a thickness of at least a few hundred meters in hydrothermal areas at YNP and that the maximum degree or maximum thickness of demagnetization correlates closely with the location of hydrothermal activity and mapped alteration.

  18. Use of Ra isotopes to deduce rapid transfer of sediment-derived inputs off Kerguelen

    NASA Astrophysics Data System (ADS)

    Sanial, V.; van Beek, P.; Lansard, B.; Souhaut, M.; Kestenare, E.; d'Ovidio, F.; Zhou, M.; Blain, S.

    2015-03-01

    The Southern Ocean is known to be the largest high-nutrient, low-chlorophyll (HNLC) region of the global ocean due to iron limitation. However, a large phytoplankton bloom develops annually downstream of the Kerguelen Islands, a bloom which is sustained partly by iron released from the sediments deposited onto the shelves. In the framework of the KEOPS-2 project, we used radium isotopes (224Ra, T1/2 = 3.66 d; 223Ra, T1/2 = 11.4 d; 228Ra, T1/2 = 5.75 yr) to provide information on the origin of iron fertilization and on the timescales of the transfer of sediment-derived inputs (including iron and other micronutrients) towards offshore waters. Significant 224Ra and 223Ra activities were found in the near vicinity of the Kerguelen Islands, in agreement with the short half-lives of these isotopes. Significant 224Ra and 223Ra activities were also detected up to 200 km downstream of the islands and more unexpectedly in offshore waters south of the polar front. These observations thus clearly indicate (i) that the sediment-derived inputs are rapidly transferred towards offshore waters (on timescales on the order of several days up to several weeks) and (ii) that the polar front is not a physical barrier for the chemical elements released from the sediments of the Kerguelen Plateau. The Ra data set suggests that iron and other micronutrients released by the shelves of the Kerguelen Islands may contribute to fueling the phytoplankton bloom downstream of the islands, despite the presence of the polar front. However, the heterogeneous distribution of the 224Ra and 223Ra activities in surface waters suggests that this supply across the front is not a continuous process but rather a process that is highly variable in space and time.

  19. Use of Ra isotopes to deduce rapid transfer of sediment-derived inputs off Kerguelen

    NASA Astrophysics Data System (ADS)

    Sanial, V.; van Beek, P.; Lansard, B.; Souhaut, M.; Kestenare, E.; d'Ovidio, F.; Zhou, M.; Blain, S.

    2014-09-01

    The Southern Ocean is known as the largest High-Nutrient, Low-Chlorophyll (HNLC) region of the global ocean due to iron limitation. However, a large phytoplankton bloom develops annually downstream of the Kerguelen Islands, which is sustained partly by iron released from the sediments deposited onto the margins. In the framework of the KEOPS-2 project, we used radium isotopes (224Ra, T1/2 = 3.66 d; 223Ra, T1/2 = 11.4 d; 228Ra, T1/2 = 5.75 yr) to provide information on the origin of iron fertilization and on the timescales of the transfer of sediment-derived inputs (including iron and other micronutrients) towards offshore waters. Significant 223Ra and 223Ra activities were found in the near vicinity of the Kerguelen Islands, in agreement with the short half-lives of these isotopes. Significant 224Ra and 223Ra activities were also detected up to 200 km downstream of the islands and more unexpectedly in offshore waters south of the Polar Front. These observations thus clearly indicate (i) that the sediment-derived inputs are rapidly transferred towards offshore waters (on timescales in the order of several days up to several weeks) and (ii) that the Polar Front is not a physical barrier for the chemical elements released from the sediments of Kerguelen Plateau. The Ra dataset suggests that iron and other micronutrients released by the shallow sediments of the Kerguelen margins may contribute to fuel the phytoplankton bloom downstream of the islands, despite the presence of the Polar Front. However, the heterogeneous distribution of the 224Ra and 223Ra activities in surface waters suggests that this supply across the front is not a continuous process, but rather a process that is highly variable in space and time.

  20. Error analysis of the converted wave deduced by equivalent velocity assumption

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Wang, Yun; Yin, Junjie; Gao, Xing

    2012-05-01

    Based on the assumption of the equivalent velocity and offset, the converted wave travel-time equation, which has a double square root due to the asymmetric ray-path of the down-going P-wave and the up-coming S-wave, can be transformed into a single square root equation if the common scatterpoint (CSP) gathers are binned. This method simplifies the equation and decreases the errors of converted wave migration transferred by P-wave velocity error, compared to the equivalent offset method (EOM) migration proposed by Bancroft, Geiger and Foltinek . In this paper, the errors caused by the introduction of equivalent velocity for the PS-wave are analysed in detail. The discrete errors and effects introduced by discretization of the equivalent offset are presented, and finally the conditions for applying CSP gathers for PS-wave processing under the control of reasonable error limits are derived.

  1. Mechanism for starch granule ghost formation deduced from structural and enzyme digestion properties.

    PubMed

    Zhang, Bin; Dhital, Sushil; Flanagan, Bernadine M; Gidley, Michael J

    2014-01-22

    After heating in excess water under little or no shear, starch granules do not dissolve completely but persist as highly swollen fragile forms, commonly termed granule "ghosts". The macromolecular architecture of these ghosts has not been defined, despite their importance in determining characteristic properties of starches. In this study, amylase digestion of isolated granule ghosts from maize and potato starches is used as a probe to study the mechanism of ghost formation, through microstructural, mesoscopic, and molecular scale analyses of structure before and after digestion. Digestion profiles showed that neither integral nor surface proteins/lipids were crucial for control of either ghost digestion or integrity. On the basis of the molecular composition and conformation of enzyme-resistant fractions, it was concluded that the condensed polymeric surface structure of ghost particles is mainly composed of nonordered but entangled amylopectin (and some amylose) molecules, with limited reinforcement through partially ordered enzyme-resistant structures based on amylose (for maize starch; V-type order) or amylopectin (for potato starch; B-type order). The high level of branching and large molecular size of amylopectin is proposed to be the origin for the unusual stability of a solid structure based primarily on temporary entanglements. PMID:24382148

  2. Surface currents in the Caribbean Sea as deduced from lagrangian observations

    SciTech Connect

    Molinari, R.L.; Spillane, M.; Brooks, I.; Atwood, D.; Duckett, C.

    1981-07-20

    The results of a satellite tracked drifting buoy experiment conducted in the Caribbean Sea from October 1975 through June 1976 are presented. The buoy trajectories suggest that the Aves Rise, Beata Ridge, and Nicaraguan Rise are regions where considerable mesoscale variability occurs in the surface flow. The variability is in the form of current deflections; small diameter eddies ranging in size from 20 to 100 km; large amplitude meanders, with amplitudes greater than 150 km; and large diameter eddies, with diameters greater than 200 km which form on and near these rises and ridges. In the central Caribbean, where the topographic relief is not as dramatic, the flow is predominantly zonal. Intensifications in the surface flow occur off the coast of Colombia, south of the Nicaraguan Rise, and south of the Yucatan Strait.

  3. Proxy late Holocene climatic record deduced from northwest Alaska beach ridges

    SciTech Connect

    Mason, O.K.; Jordan, J.W.

    1992-03-01

    A climatically sensitive, oscillatory pattern of progradation and erosion is revealed in late Holocene accretionary sand ridge and barrier island complexes of Seward Peninsula, northwest Alaska. Archaeological and geological radiocarbon dates constrain the chronology for the Cape Espenberg beach ridge plain and the Shishmaref barrier islands, 50 km to the southwest. Cape Espenberg, the depositional sink for the northeastward longshore transport system, contains the oldest sedimentary deposits: 3700 +/- 90 B.P. (B-23170) old grass from a paleosol in a low dune. The oldest date on the Shishmaref barrier islands is 1550 +/- 70 B.P. (B-23183) and implies that the modern barrier is a comparatively recent phenomenon. Late Holocene sedimentation along the Seward Peninsula varied between intervals of rapid progradation and erosion. Rapid progradation predominated from 4000-3300 B.P. and from 2000-1200 B.P., with the generation of low beach ridges without dunes, separated by wide swales. During erosional periods higher dunes built atop beach ridges: as between 3300-2000 B.P. and intermittently from 1000 B.P. to the present. Dune formation correlates with the Neoglacial and Little Ice Age glacial advances and increased alluviation in northern and central Alaska, while rapid progradation is contemporaneous with warmer intervals of soil and/or, peat formation atop alluvial terraces, dated to 4000-3500 and 2000-1000 B.P.

  4. Irradiation History of Itokawa Regolith Material Deduced from Noble Gases in the Hayabusa Samples

    NASA Astrophysics Data System (ADS)

    Nagao, Keisuke; Okazaki, Ryuji; Nakamura, Tomoki; Miura, Yayoi N.; Osawa, Takahito; Bajo, Ken-ichi; Matsuda, Shintaro; Ebihara, Mitsuru; Ireland, Trevor R.; Kitajima, Fumio; Naraoka, Hiroshi; Noguchi, Takaaki; Tsuchiyama, Akira; Yurimoto, Hisayoshi; Zolensky, Michael E.; Uesugi, Masayuki; Shirai, Kei; Abe, Masanao; Yada, Toru; Ishibashi, Yukihiro; Fujimura, Akio; Mukai, Toshifumi; Ueno, Munetaka; Okada, Tatsuaki; Yoshikawa, Makoto; Kawaguchi, Junichiro

    2011-08-01

    Noble gas isotopes were measured in three rocky grains from asteroid Itokawa to elucidate a history of irradiation from cosmic rays and solar wind on its surface. Large amounts of solar helium (He), neon (Ne), and argon (Ar) trapped in various depths in the grains were observed, which can be explained by multiple implantations of solar wind particles into the grains, combined with preferential He loss caused by frictional wear of space-weathered rims on the grains. Short residence time of less than 8 million years was implied for the grains by an estimate on cosmic-ray-produced 21Ne. Our results suggest that Itokawa is continuously losing its surface materials into space at a rate of tens of centimeters per million years. The lifetime of Itokawa should be much shorter than the age of our solar system.

  5. Interplanetary dust physical properties deduced from scattered and emitted light simulations

    NASA Astrophysics Data System (ADS)

    Lasue, J.; Levasseur-Regourd, A. C.; Fray, N.; Cottin, H.

    2007-08-01

    In situ studies as well as interplanetary dust particles collections in the earth stratosphere provide important but spatially limited information about the interplanetary dust properties. It is therefore of major importance to complement these studies through remote observations of scattered and emitted light, interpreted through numerical simulations. Physical properties of the interplanetary dust in the near-ecliptic symmetry surface, such as the local polarization, the temperature and its composition, together with their heliocentric variations, may be derived from such observations [1], giving clues to the respective contribution of the particles sources. The size distribution, as well as the shape and the composition of the particles constituting the interplanetary dust cloud are tentatively derived from scattered and emitted light observations through a model of light scattering by a cloud of solid particles constituted by spheroidal grains and aggregates thereof [2]. Considering the same particles cloud, this model allows us to simultaneously interpret the heliocentric variation of the temperature, which is different from the black body one. A good fit of the local polarization phase curve, P(?), near 1.5 AU from the Sun is obtained for a mixture of both silicates and more absorbing organics material (˜40% in mass) and for a realistic particles size distribution, typical of the interplanetary dust (power law a-3 for particles with an equivalent diameter in the 0.2 μm to 20 μm size range and a-4.4 for larger particles). The contribution of un-fragmented dust particles aggregates of cometary origin is at least 20% in mass around 1.5 AU. This size distribution can also explain the variation of temperature with the solar distance. The decrease of P(?=90°) with the solar distance between 1.5 and 0.5 AU is interpreted as a progressive disappearance of solid organics (such as HCN polymers [3] or amorphous carbon) towards the Sun, probably linked with the presence of an extended zone of thermal degradation [4]. The drastic change of P(?=90°) closer to the Sun, below 0.5 AU, could be the result of other minerals (e.g. silicates) degradations in this zone. [1] Levasseur-Regourd et al., In: Interplanetary dust, Grün, Gustafson, Dermott, Fechtig (eds), pp. 57 (2001) [2] Lasue and Levasseur-Regourd, J. Quant. Spectros. Radiat. Transfer 100, 220 (2006) [3] Fray et al., Meteoritics and Planetary Science 39, 581, (2004) [4] Lasue et al., Astron. Astrophys. (submitted)

  6. Education et Developpement. Une Approche aux Interventions d'Education en Milieux Defavorises. MEQ, Mars 1975.

    ERIC Educational Resources Information Center

    Centrale de L'Enseignement du Quebec (Canada).

    This document is a commentary on a report by the Quebec Ministry of Education on the problem of educating the disadvantaged. One basic criticism of the report is that it is not enough to decry the failure of the schools and propose a strategy of compensatory education to solve the problem of disadvantagement. It is necessary to realize that the…

  7. Deducing the Energetic Cost of Protein Folding in Zinc Finger Proteins Using Designed Metallopeptides

    SciTech Connect

    Reddi,A.; Guzman, T.; Breece, r.; Tierney, D.; Gibney, B.

    2007-01-01

    Zinc finger transcription factors represent the largest single class of metalloproteins in the human genome. Binding of Zn(II) to their canonical Cys4, Cys3His1, or Cys2His2 sites results in metal-induced protein folding events required to achieve their proper structure for biological activity. The thermodynamic contribution of Zn(II) in each of these coordination spheres toward protein folding is poorly understood because of the coupled nature of the metal-ligand and protein-protein interactions. Using an unstructured peptide scaffold, GGG, we have employed fluorimetry, potentiometry, and calorimetry to determine the thermodynamics of Zn(II) binding to the Cys4, Cys3His1, and Cys2His2 ligand sets with minimal interference from protein folding effects. The data show that Zn(II) complexation is entropy driven and modulated by proton release. The formation constants for Zn(II)-GGG with a Cys4, Cys3His1, or Cys2His2 site are 5.6 x 1016, 1.5 x 1015, or 2.5 x 1013 M-1, respectively. Thus, the Zn(II)-Cys4, Zn(II)-Cys3His1, and Zn(II)-Cys2His2 interactions can provide up to 22.8, 20.7, and 18.3 kcal/mol, respectively, in driving force for protein stabilization, folding, and/or assembly at pH values above the ligand pKa values. While the contributions from the three coordination motifs differ by 4.5 kcal/mol in Zn(II) affinity at pH 9.0, they are equivalent at physiological pH, ?G = -16.8 kcal/mol or a Ka = 2.0 x 1012 M-1. Calorimetric data show that this is due to proton-based enthalpy-entropy compensation between the favorable entropic term from proton release and the unfavorable enthalpic term due to thiol deprotonation. Since protein folding effects have been minimized in the GGG scaffold, these peptides possess nearly the tightest Zn(II) affinities possible for their coordination motifs. The Zn(II) affinities in each coordination motif are compared between the GGG scaffold and natural zinc finger proteins to determine the free energy required to fold the latter. Several proteins have identical Zn(II) affinities to GGG. That is, little, if any, of their Zn(II) binding energy is required to fold the protein, whereas some have affinities weakened by up to 5.7 kcal/mol; i.e., the Zn(II) binding energy is being used to fold the protein.

  8. Accretion timescale and impact history of Mars deduced from the isotopic systematics of martian meteorites

    NASA Astrophysics Data System (ADS)

    Borg, Lars E.; Brennecka, Gregory A.; Symes, Steven J. K.

    2016-02-01

    High precision Sm-Nd isotopic analyses have been completed on a suite of 11 martian basaltic meteorites in order to better constrain the age of silicate differentiation on Mars associated with the formation of their mantle sources. These data are used to evaluate the merits and disadvantages of various mathematical approaches that have been employed in previous work on this topic. Ages determined from the Sm-Nd isotopic systematics of individual samples are strongly dependent on the assumed Nd isotopic composition of the bulk planet. This assumption is problematic given differences observed between the Nd isotopic composition of Earth and chondritic meteorites and the fact that these materials are both commonly used to represent bulk planetary Nd isotopic compositions. Ages determined from the slope of 146Sm-142Nd whole rock isochrons are not dependent on the assumed 142Nd/144Nd ratio of the planet, but require the sample suite to be derived from complementary, contemporaneously-formed reservoirs. In this work, we present a mathematical expression that defines the age of formation of the source regions of such a suite of samples that is based solely on the slope of a 143Nd-142Nd whole rock isochron and is also independent of any a priori assumptions regarding the bulk isotopic composition of the planet. This expression is also applicable to mineral isochrons and has been used to successfully calculate 143Nd-142Nd model crystallization ages of early refractory solids as well as lunar samples. This permits ages to be obtained using only Nd isotopic measurements without the need for 147Sm/144Nd isotope dilution determinations. When used in conjunction with high-precision Nd isotopic measurements completed on martian meteorites this expression yields an age of formation of the martian basaltic meteorite source regions of 4504 ± 6 Ma. Because the Sm-Nd model ages for the formation of martian source regions are commonly interpreted to record the age at which large scale mantle reservoirs formed during planetary differentiation associated with magma ocean solidification, the age determined here implies that magma ocean solidification occurred several tens of millions of years after the beginning of the Solar System. Recent thermal models, however, suggest that Mars-sized bodies cool rapidly in less than ∼5 Ma after accretion ceases, even in the presence of a thick atmosphere. Assuming these models are correct, an extended period of accretion is necessary to provide a mechanism to keep portions of the martian mantle partially molten until 4504 Ma. Late accretional heating of Mars could either be associated with protracted accretion occurring at a quasi-steady state or alternatively be associated with a late giant impact. If this scenario is correct, then accretion of Mars-sized bodies takes up to 60 Ma and is likely to be contemporaneous with the core formation and possibly the onset of silicate differentiation. This further challenges the concept that isotopic equilibrium is attained during primordial evolution of planets, and may help to account for geochemical evidence implying addition of material into planetary interiors after core formation was completed.

  9. Cosmic-ray source and local interstellar spectra deduced from the isotopes of hydrogen and helium.

    NASA Technical Reports Server (NTRS)

    Comstock, G. M.; Hsieh, K. C.; Simpson, J. A.

    1972-01-01

    A self-consistent model for cosmic-ray hydrogen and helium propagation from the sources in the Galaxy to the orbit of earth is obtained, taking into account experimental information now available on the isotopes H-1, H-2, He-3, and He-4. The only adjustable parameters include the shape of the energy spectra of H-1 and He-4 at the time of source injection, the distribution of particle path lengths in interstellar space, and the solar modulation parameters. It is found that the allowed form of the source differential spectra of the H-1 and He-4 nuclei is dominated by a power law in total energy.

  10. Concentration of methane in the troposphere deduced from 1951 infrared solar spectra

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Levine, J. S.; Miles, T.

    1985-01-01

    The 1-2 percent increase in tropospheric methane determined from gas chromatographic measurements since 1977 has important implications for atmospheric photochemistry and climate. To extend the measurement baseline, solar absorption spectra have been analyzed and mean troposphere CH4 mixing ratios for the years 1951 and 1981, and an average rate of CH4 increase of 1.1 + or - 0.2 percent per year is found for this period.

  11. Surface currents in the Caribbean Sea as deduced from Lagrangian observations

    NASA Astrophysics Data System (ADS)

    Molinari, Robert L.; Spillane, Michael; Brooks, Irving; Atwood, Donald; Duckett, Carol

    1981-07-01

    The results of a satellite tracked drifting buoy experiment conducted in the Caribbean Sea from October 1975 through June 1976 are presented. The buoy trajectories suggest that the Aves Rise, Beata Ridge, and Nicaraguan Rise are regions where considerable mesoscale variability occurs in the surface flow. The variability is in the form of current deflections; small diameter eddies ranging in size from 20 to 100 km; large amplitude meanders, with amplitudes greater than 150 km; and large diameter eddies, with diameters greater than 200 km which form on and near these rises and ridges. In the central Caribbean, where the topographic relief is not as dramatic, the flow is predominantly zonal. Intensifications in the surface flow occur off the coast of Colombia, south of the Nicaraguan Rise, and south of the Yucatan Strait.

  12. Paleoceanography of the Okhotsk Sea During the Last Glacial Cycle Deduced From Radiolarian Record

    NASA Astrophysics Data System (ADS)

    Takahashi, K.; Okazaki, Y.; Yoshitani, H.

    2001-05-01

    Paleoceanographic record contained in the Okhotsk Sea sediments provide pertinent information on global climate change during the late Pleistocene. This stems from its unique oceanographic nature with seasonal sea-ice cover in this relatively low latitude setting resulting in formation of the North Pacific Intermediate Water (NPIW). In order to unravel siliceous microfossil record in the Okhotsk Sea, we have acquired four piston-cores and more than a dozen multiple cores, together with flux materials from four time-series sediment traps at two locations, were obtained in the area during the 1998-1999 periods on board R/V Professor Khromov, Far East Hydrometeological Institute, Russia, as part of "Joint Japanese-Russian-U. S. Study of the Sea of Okhotsk". Seasonal fluxes of radiolarians (No. shells m-2 day-1) showed significant maxima during summer through autumn at both trap stations. The radiolarian fluxes during August to November accounted for 60-87 percent of total annual flux, suggesting that the radiolarian production is significantly controlled by the sea-ice coverage. The radiolarian accumulation rates (RAR: No. shells cm-2 kyr-1) from piston cores, varied substantially, roughly corresponding to the glacial-interglacial cycles. Especially the RAR of Cycladophora davisiana, the dominant radiolarian taxon in the Holocene Okhotsk Sea sediments, contributed much to this trend. The last occurrence (LO) of Lychnocanomma nipponica sakaii in the Okhotsk Sea is at about 50ky BP, which is synchronous with that in the North Pacific. Such a synchronous nature of the LO of this species is important for biostratigraphy of the North Pacific and the northern marginal seas for the late Pleistocene.

  13. Petrographically deduced triassic climate for the Deep River Basin, eastern piedmont of North Carolina

    SciTech Connect

    McCarn, S.T.; Mansfield, C.F.

    1985-01-01

    A petrographic comparison of Triassic, fluvial sandstones from the Deep River Basin in the eastern piedmont of North Carolina with nearby Holocene stream sands (1) indicates that he Triassic climate was more arid than today's and (2) distinguishes an eastern, more plutonic terrane from a western, more metamorphic source terrane. The paleoclimatic interpretation is based on differences in framework composition between modern and ancient sands of the same grain size, derived from the same rock type, transported similar distances and deposited in similar settings. The Triassic sandstones contain more lithic-fragments but less quartz than otherwise equivalent, modern sand in the Deep River Basin. Feldspar content is more complex, controlled by both source-rock composition and climate. Sand from the more plutonic terrane contains more feldspar and plutonic lithic-fragments than sand from the more metamorphic terrane, which contains more quartz and metamorphic lithic-fragments. This petrographic interpretation of the Triassic sandstones along with the presence of coal, limestone, chert and caliche in the middle of the section suggests that the Triassic climate was cyclic, changing from arid to humid and back to arid. Plate-tectonic reconstructions place the Deep River Basin between the Triassic equator and Tropic of cancer, where the easterly trade winds would predominate. Therefore, the arid portions of the cycle could have been due to a periodic, orographic, rain shadow formed as the result of intermittent movement along the Jonesboro Fault, creating a highland area east of the Deep River Basin.

  14. Evolution of geothermal fluids deduced from chemistry plots: Yellowstone National Park (U.S.A.)

    USGS Publications Warehouse

    Mazor, E.; Thompson, J.M.

    1982-01-01

    Large amounts of chemical data, obtained in geothermal fields, may readily be sorted-out by the aid of a simple set of graphs that provide a clear over-all picture and facilitate the understanding of geochemical processes taking place. As a case study, data from several hundred samples of the thermal springs at the well-known Yellowstone National Park are discussed. The pattern obtained seems to indicate: (1) geochemical similarity between the spring groups of Heart Lake, Shoshone, Upper, Midway, Lower and Norris Geyser Basins, i.e., a geochemical uniformity of major spring groups located over 40 km apart; (2) these groups may be described as originating from a common fluid, most resembling the composition of Norris waters, accompanied by CO2, and other volatiles, that react with igneous rocks, forming local variations; (3) the secondary reactions occur at (medium) depth, before the ascent to the surface; (4) extensive concentration-dilution processes occur during the ascent to the surface. The water of the Mammoth group may be described as originating from the same Norris-like fluid that has been diluted (low Na and Cl contents) and intensively reacted with carbonaceous rocks, thus gaining in Ca, Mg, SO4, and HCO3. ?? 1982.

  15. Methanogenic capabilities of ANME-archaea deduced from (13) C-labelling approaches.

    PubMed

    Bertram, Sebastian; Blumenberg, Martin; Michaelis, Walter; Siegert, Michael; Krüger, Martin; Seifert, Richard

    2013-08-01

    Anaerobic methanotrophic archaea (ANME) are ubiquitous in marine sediments where sulfate dependent anaerobic oxidation of methane (AOM) occurs. Despite considerable progress in the understanding of AOM, physiological details are still widely unresolved. We investigated two distinct microbial mat samples from the Black Sea that were dominated by either ANME-1 or ANME-2. The (13) C lipid stable isotope probing (SIP) method using labelled substances, namely methane, bicarbonate, acetate, and methanol, was applied, and the substrate-dependent methanogenic capabilities were tested. Our data provide strong evidence for a versatile physiology of both, ANME-1 and ANME-2. Considerable methane production rates (MPRs) from CO2 -reduction were observed, particularly from ANME-2 dominated samples and in the presence of methane, which supports the hypothesis of a co-occurrence of methanotrophy and methanogenesis in the AOM systems (AOM/MPR up to 2:1). The experiments also revealed strong methylotrophic capabilities through (13) C-assimilation from labelled methanol, which was independent of the presence of methane. Additionally, high MPRs from methanol were detected in both of the mat samples. As demonstrated by the (13) C-uptake into lipids, ANME-1 was found to thrive also under methane free conditions. Finally, C35 -isoprenoid hydrocarbons were identified as new lipid biomarkers for ANME-1, most likely functioning as a hydrogen sink during methanogenesis.

  16. Mining a sea of data: deducing the environmental controls of ocean chlorophyll.

    PubMed

    Irwin, Andrew J; Finkel, Zoe V

    2008-01-01

    Chlorophyll biomass in the surface ocean is regulated by a complex interaction of physiological, oceanographic, and ecological factors and in turn regulates the rates of primary production and export of organic carbon to the deep ocean. Mechanistic models of phytoplankton responses to climate change require the parameterization of many processes of which we have limited knowledge. We develop a statistical approach to estimate the response of remote-sensed ocean chlorophyll to a variety of physical and chemical variables. Irradiance over the mixed layer depth, surface nitrate, sea-surface temperature, and latitude and longitude together can predict 83% of the variation in log chlorophyll in the North Atlantic. Light and nitrate regulate biomass through an empirically determined minimum function explaining nearly 50% of the variation in log chlorophyll by themselves and confirming that either light or macronutrients are often limiting and that much of the variation in chlorophyll concentration is determined by bottom-up mechanisms. Assuming the dynamics of the future ocean are governed by the same processes at work today, we should be able to apply these response functions to future climate change scenarios, with changes in temperature, nutrient distributions, irradiance, and ocean physics. PMID:19043583

  17. Aerosol-Precipitation Responses Deduced from Ship tracks as Observed by CloudSat

    NASA Astrophysics Data System (ADS)

    Christensen, M.; Stephens, G. L.

    2011-12-01

    Ship tracks, produced from the exhaust plumes of ocean going vessels were analyzed using the 94-GHZ cloud profiling radar on the CloudSat satellite to examine the precipitation response of marine stratocumulus to changes in aerosol concentration. Ship tracks provide an ideal laboratory to study this response because the regions of clouds that are heavily contaminated by pollution can be separated from adjacent regions of clouds formed in the clean marine boundary layer. Several hundred ship tracks, coinciding with the radar and lidar observations from CloudSat and Calipso, were identified in MODIS imagery. The results demonstrate that, aerosol plumes from ships tend to decrease the spatial extent of rainfall (rain cover fraction) and intensity compared to the nearby pristine clouds. However, there were a substantial fraction of cases (30%), which exhibited increased rainfall. The sign and strength of the precipitation response was strongly tied to the mesoscale structure of the clouds. When the clouds exhibited closed cellular structures, liquid water amount, rainfall (-63%), and rain cover fraction significantly decreased (-55%). These reductions in rainfall were primarily associated with the decrease in rain cover fraction over the ship track domain. The opposite occurred in the open cell regime. Ship plumes ingested into this regime resulted in deeper, wetter, rainier, and brighter clouds, where rainfall increased by 88% primarily due to changes in intensity and to a lesser extent rain cover fraction. Microphysical changes almost always led to significantly smaller droplet radii in ship tracks, even when precipitation was increased. On the other hand, macrophysical changes (liquid water path) varied in magnitude and sign, and typically followed the direction of the precipitation response. The results presented here underline the need to consider the mesoscale structure of stratocumulus when examining the cloud dynamic response to changes in aerosol concentration.

  18. Atomic oxygen on the Venus nightside: Global distribution deduced from airglow mapping

    NASA Astrophysics Data System (ADS)

    Soret, L.; Gérard, J.-C.; Montmessin, F.; Piccioni, G.; Drossart, P.; Bertaux, J.-L.

    2012-02-01

    The Visible and Infra-Red Thermal Imaging Spectrometer (VIRTIS) instrument on board the Venus Express spacecraft has measured the O 2(a 1Δ) nightglow distribution at 1.27 μm in the Venus mesosphere for more than two years. Nadir observations have been used to create a statistical map of the emission on Venus nightside. It appears that the statistical 1.6 MR maximum of the emission is located around the antisolar point. Limb observations provide information on the altitude and on the shape of the emission layer. We combine nadir observations essentially covering the southern hemisphere, corrected for the thermal emission of the lower atmosphere, with limb profiles of the northern hemisphere to generate a global map of the Venus nightside emission at 1.27 μm. Given all the O 2(a 1Δ) intensity profiles, O 2(a 1Δ) and O density profiles have been calculated and three-dimensional maps of metastable molecular and atomic oxygen densities have been generated. This global O density nightside distribution improves that available from the VTS3 model, which was based on measurements made above 145 km. The O 2(a 1Δ) hemispheric average density is 2.1 × 10 9 cm -3, with a maximum value of 6.5 × 10 9 cm -3 at 99.2 km. The O density profiles have been derived from the nightglow data using CO 2 profiles from the empirical VTS3 model or from SPICAV stellar occultations. The O hemispheric average density is 1.9 × 10 11 cm -3 in both cases, with a mean altitude of the peak located at 106.1 km and 103.4 km, respectively. These results tend to confirm the modeled values of 2.8 × 10 11 cm -3 at 104 km and 2.0 × 10 11 cm -3 at 110 km obtained by Brecht et al. [Brecht, A., Bougher, S.W., Gérard, J.-C., Parkinson, C.D., Rafkin, S., Foster, B., 2011a. J. Geophys. Res., in press] and Krasnopolsky [Krasnopolsky, V.A., 2010. Icarus 207, 17-27], respectively. Comparing the oxygen density map derived from the O 2(a 1Δ) nightglow observations, it appears that the morphology is very different and that the densities obtained in this study are about three times higher than those predicted by the VTS3 model.

  19. Inner ear anatomy is a proxy for deducing auditory capability and behaviour in reptiles and birds.

    PubMed

    Walsh, Stig A; Barrett, Paul M; Milner, Angela C; Manley, Geoffrey; Witmer, Lawrence M

    2009-04-01

    Inferences of hearing capabilities and audition-related behaviours in extinct reptiles and birds have previously been based on comparing cochlear duct dimensions with those of living species. However, the relationship between inner-ear bony anatomy and hearing ability or vocalization has never been tested rigorously in extant or fossil taxa. Here, micro-computed tomographic analysis is used to investigate whether simple endosseous cochlear duct (ECD) measurements can be fitted to models of hearing sensitivity, vocalization, sociality and environmental preference in 59 extant reptile and bird species, selected based on their vocalization ability. Length, rostrocaudal/mediolateral width and volume measurements were taken from ECD virtual endocasts and scaled to basicranial length. Multiple regression of these data with measures of hearing sensitivity, vocal complexity, sociality and environmental preference recovered positive correlations between ECD length and hearing range/mean frequency, vocal complexity, the behavioural traits of pair bonding and living in large aggregations, and a negative correlation between ECD length/rostrocaudal width and aquatic environments. No other dimensions correlated with these variables. Our results suggest that ECD length can be used to predict mean hearing frequency and range in fossil taxa, and that this measure may also predict vocal complexity and large group sociality given comprehensive datasets.

  20. The evolution of the Vahlkampfiidae as deduced from 16S-like ribosomal RNA analysis.

    PubMed

    Hinkle, G; Sogin, M L

    1993-01-01

    The amoebae, a phenotypically diverse, paraphyletic group of protists, have been largely neglected by molecular phylogeneticists. To better understand the evolution of amoebae, we sequenced and analyzed the 16S-like ribosomal RNA genes of three vahlkampfiid amoebae: Paratetramitus jugosus, Tetramitus rostratus and Vahlkampfia lobospinosa. The Vahlkampfiidae lineage is monophyletic, branches early along the eukaryotic line of descent, and is not a close relative of the multicellular amoebae that also reversibly transform from amoebae to flagellates.

  1. Characterization of defensin gene from abalone Haliotis discus hannai and its deduced protein

    NASA Astrophysics Data System (ADS)

    Hong, Xuguang; Sun, Xiuqin; Zheng, Minggang; Qu, Lingyun; Zan, Jindong; Zhang, Jinxing

    2008-11-01

    Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals’ acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides (including six Cys), molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar (70% in common) to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin (hd-def), a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino.

  2. Molecular basis of human body odour formation: insights deduced from corynebacterial genome sequences.

    PubMed

    Barzantny, H; Brune, I; Tauch, A

    2012-02-01

    During the past few decades, there has been an increased interest in the essential role of commensal skin bacteria in human body odour formation. It is now generally accepted that skin bacteria cause body odour by biotransformation of sweat components secreted in the human axillae. Especially, aerobic corynebacteria have been shown to contribute strongly to axillary malodour, whereas other human skin residents seem to have little influence. Analysis of odoriferous sweat components has shown that the major odour-causing substances in human sweat include steroid derivatives, short volatile branched-chain fatty acids and sulphanylalkanols. In this mini-review, we describe the molecular basis of the four most extensively studied routes of human body odour formation, while focusing on the underlying enzymatic processes. Considering the previously reported role of β-oxidation in odour formation, we analysed the genetic repertoire of eight Corynebacterium species concerning fatty acid metabolism. We particularly focused on the metabolic abilities of the lipophilic axillary isolate Corynebacterium jeikeium K411.

  3. The production rate of cosmogenic 21-Ne in chondrites deduced from 81-Kr measurements

    NASA Technical Reports Server (NTRS)

    Schultz, L.; Freundel, M.

    1986-01-01

    Cosmogenic Ne-21 is used widely to calculate exposure ages of stone meteorites. In order to do so, the production rate P(21) must be known. This rate, however, is dependent on the chemical composition of the meteorite as well as the mass of, and position within, the meteoroid during its exposure to the cosmic radiation. Even for a mean shielding the production rates determined from measurments of different radionuclides vary by a factor of two. A method that can be used to determine exposure ages of meteorites that avoids shielding and chemical composition corrections is the -81-Kr-Kr-method. However, for chondrites, in many cases, the direct determination of production rates for the Kr isotopes is prevented by the trapped gases and the neutron effects on bromine. Therefore, this method was applied to four eucrite falls and then their 81-Kr-83-Kr-ages were compared to their cosmogenic Ne-21 and Ar-38 concentrations. The eucrites Bouvante-le-Haut, Juvinas, Sioux County, and Stannern were chosen for these measurements because of their similar chemical composition regarding the major elements.

  4. Deducing Wild 2 Components with a Statistical Dataset of Olivine in Chondrite Matrix

    NASA Technical Reports Server (NTRS)

    Frank, D. R.; Zolensky, M. E.; Le, L.

    2012-01-01

    Introduction: A preliminary exam of the Wild 2 olivine yielded a major element distribution that is strikingly similar to those for aqueously altered carbonaceous chondrites (CI, CM, and CR) [1], in which FeO-rich olivine is preferentially altered. With evidence lacking for large-scale alteration in Wild 2, the mechanism for this apparent selectivity is poorly understood. We use a statistical approach to explain this distribution in terms of relative contributions from different chondrite forming regions. Samples and Analyses: We have made a particular effort to obtain the best possible analyses of both major and minor elements in Wild 2 olivine and the 5-30 micrometer population in chondrite matrix. Previous studies of chondrite matrix either include larger isolated grains (not found in the Wild 2 collection) or lack minor element abundances. To overcome this gap in the existing data, we have now compiled greater than 10(exp 3) EPMA analyses of matrix olivine in CI, CM, CR, CH, Kakangari, C2-ungrouped, and the least equilibrated CO, CV, LL, and EH chondrites. Also, we are acquiring TEM/EDXS analyses of the Wild 2 olivine with 500s count times, to reduce relative errors of minor elements with respect to those otherwise available. Results: Using our Wild 2 analyses and those from [2], the revised major element distribution is more similar to anhydrous IDPs than previous results, which were based on more limited statistics (see figure below). However, a large frequency peak at Fa(sub 0-1) still persists. All but one of these grains has no detectable Cr, which is dissimilar to the Fa(sub 0-1) found in the CI and CM matrices. In fact, Fa(sub 0-1) with strongly depleted Cr content is a composition that appears to be unique to Kakangari and enstatite (highly reduced) chondrites. We also note the paucity of Fa(sub greater than 58), which would typically indicate crystallization in a more oxidizing environment [3]. We conclude that, relative to the bulk of anhydrous IDPs, Wild 2 may have received a larger contribution from the Kakangari and/or enstatite chondrite forming regions. Alternatively, Wild 2 may have undergone accretion in an anomalously reducing region, marked by nebular condensation of this atypical forsterite. In [4], a similar conclusion was reached with an Fe-XANES study. We will also use similar lines of reasoning, and our previous conclusions in [5], to constrain the relative contributions of silicates that appear to have been radially transported from different ordinary and carbonaceous chondrite forming regions to the Kuiper Belt. In addition, the widespread depletion of Cr in these FeO-rich (Fa(sub greater than 20)) fragments is consistent with mild thermal metamorphism in Wild 2.

  5. Use of Nanostructure-Initiator Mass Spectrometry to Deduce Selectivity of Reaction in Glycoside Hydrolases

    PubMed Central

    Deng, Kai; Takasuka, Taichi E.; Bianchetti, Christopher M.; Bergeman, Lai F.; Adams, Paul D.; Northen, Trent R.; Fox, Brian G.

    2015-01-01

    Chemically synthesized nanostructure-initiator mass spectrometry (NIMS) probes derivatized with tetrasaccharides were used to study the reactivity of representative Clostridium thermocellum β-glucosidase, endoglucanases, and cellobiohydrolase. Diagnostic patterns for reactions of these different classes of enzymes were observed. Results show sequential removal of glucose by the β-glucosidase and a progressive increase in specificity of reaction from endoglucanases to cellobiohydrolase. Time-dependent reactions of these polysaccharide-selective enzymes were modeled by numerical integration, which provides a quantitative basis to make functional distinctions among a continuum of naturally evolved catalytic properties. Consequently, our method, which combines automated protein translation with high-sensitivity and time-dependent detection of multiple products, provides a new approach to annotate glycoside hydrolase phylogenetic trees with functional measurements. PMID:26579511

  6. A partially differentiated interior for (1) Ceres deduced from its gravity field and shape

    NASA Astrophysics Data System (ADS)

    Park, R. S.; Konopliv, A. S.; Bills, B. G.; Rambaux, N.; Castillo-Rogez, J. C.; Raymond, C. A.; Vaughan, A. T.; Ermakov, A. I.; Zuber, M. T.; Fu, R. R.; Toplis, M. J.; Russell, C. T.; Nathues, A.; Preusker, F.

    2016-09-01

    Remote observations of the asteroid (1) Ceres from ground- and space-based telescopes have provided its approximate density and shape, leading to a range of models for the interior of Ceres, from homogeneous to fully differentiated. A previously missing parameter that can place a strong constraint on the interior of Ceres is its moment of inertia, which requires the measurement of its gravitational variation together with either precession rate or a validated assumption of hydrostatic equilibrium. However, Earth-based remote observations cannot measure gravity variations and the magnitude of the precession rate is too small to be detected. Here we report gravity and shape measurements of Ceres obtained from the Dawn spacecraft, showing that it is in hydrostatic equilibrium with its inferred normalized mean moment of inertia of 0.37. These data show that Ceres is a partially differentiated body, with a rocky core overlaid by a volatile-rich shell, as predicted in some studies. Furthermore, we show that the gravity signal is strongly suppressed compared to that predicted by the topographic variation. This indicates that Ceres is isostatically compensated, such that topographic highs are supported by displacement of a denser interior. In contrast to the asteroid (4) Vesta, this strong compensation points to the presence of a lower-viscosity layer at depth, probably reflecting a thermal rather than compositional gradient. To further investigate the interior structure, we assume a two-layer model for the interior of Ceres with a core density of 2,460-2,900 kilograms per cubic metre (that is, composed of CI and CM chondrites), which yields an outer-shell thickness of 70-190 kilometres. The density of this outer shell is 1,680-1,950 kilograms per cubic metre, indicating a mixture of volatiles and denser materials such as silicates and salts. Although the gravity and shape data confirm that the interior of Ceres evolved thermally, its partially differentiated interior indicates an evolution more complex than has been envisioned for mid-sized (less than 1,000 kilometres across) ice-rich rocky bodies.

  7. The Building of Continental Crust in the Archean Superior Province, Canada, Deduced from Heat Flow Data

    NASA Astrophysics Data System (ADS)

    Jaupart, C. P.; Mareschal, J.

    2013-12-01

    Making continental crust can be achieved in several different ways, including extraction of melts from a mantle plume or from a subducting slab. Cratonization, i.e. the formation of mature stable continental crust, requires two additional steps, horizontal accretion of a number of terranes and belts and vertical internal differentiation leading to separation of an enriched upper crust from a depleted lower crust. Heat flow and heat production data provide constraints on the bulk crustal composition as well as on the degree of internal differentiation, and hence bring key constraints on crust-building processes. Together with older data, new measurements from the Archean Superior Province, Canadian Shield, are used to document how and with what material this large piece of continental crust was built. The southern Superior Province was assembled out of an old nucleus made of gneisses and tonalite-granodiorite plutons called the North Caribou Super Terrane, and a number of belts and terranes that were sequentially docked to its southern margin. The North Caribou area was subjected to magmatic and metamorphic activity spanning about 1.1 Gy from 3.8 to 2.7 Gy. Alternating belts of metasedimentary and volcanic rocks on the one hand and greenstone and plutonic rocks on the other hand made the craton grow to about twice its initial size in ≈100 My. The average heat flow is much lower in the North Caribou core region than in the younger volcanic/plutonic belts (Wabigoon and Wawa-Abitibi) to the South, 30 versus 44 mW/m2. The heat flux is also slightly higher (48mW/m2) in the metasedimentary (English River and Quetico) than in the plutonic belts. The two volcanic/plutonic belts share the same characteristics, testifying to a remarquable uniformity of crust-building mechanisms on a large-scale. The marked difference between the older craton nucleus and the younger belts requires the operation of two very different processes. The very shape and geological structure of the belts indicate that they were island arcs and associated basins. The craton nucleus was formed in a different way, presumably by melting in a mantle upwelling. In addition, the craton nucleus has an enriched upper crust, in contrast to the younger belts that do not exhibit marked internal differentiation. Late, post-orogenic, magmatism that dots the whole southern Superior Province is probably due to internal heating of the crust by its own radioactive sources.

  8. Mechanisms of flagellar motility deduced from backward-swimming bull sperm.

    PubMed

    Phillips, D M; Kalay, D

    1984-07-01

    Under certain conditions of cryopreservation, bull spermatozoa undergo an interesting structural alteration. The sperm tail becomes bent back on itself to form a hairpin shape. The bend in the tail occurs at a very precise point, 11 microns behind the neck, and it causes the tail to become kinked. Flagellar microtubules and dense fibers become broken and the ninefold symmetry of the flagellum is greatly distored. Although the portion of the flagellum between the kink and the sperm head does not propagate a wave, the distal portion of the flagellum propagates a base-to-tip wave, causing the spermatozoan to progress backward. These observations suggest that the mammalian spermatozoon does not need basal structures to propagate a flagellar wave.

  9. Molecular evolution of arthropod color vision deduced from multiple opsin genes of jumping spiders.

    PubMed

    Koyanagi, Mitsumasa; Nagata, Takashi; Katoh, Kazutaka; Yamashita, Shigeki; Tokunaga, Fumio

    2008-02-01

    Among terrestrial animals, only vertebrates and arthropods possess wavelength-discrimination ability, so-called "color vision". For color vision to exist, multiple opsins which encode visual pigments sensitive to different wavelengths of light are required. While the molecular evolution of opsins in vertebrates has been well investigated, that in arthropods remains to be elucidated. This is mainly due to poor information about the opsin genes of non-insect arthropods. To obtain an overview of the evolution of color vision in Arthropoda, we isolated three kinds of opsins, Rh1, Rh2, and Rh3, from two jumping spider species, Hasarius adansoni and Plexippus paykulli. These spiders belong to Chelicerata, one of the most distant groups from Hexapoda (insects), and have color vision as do insects. Phylogenetic analyses of jumping spider opsins revealed a birth and death process of color vision evolution in the arthropod lineage. Phylogenetic positions of jumping spider opsins revealed that at least three opsins had already existed before the Chelicerata-Pancrustacea split. In addition, sequence comparison between jumping spider Rh3 and the shorter wavelength-sensitive opsins of insects predicted that an opsin of the ancestral arthropod had the lysine residue responsible for UV sensitivity. These results strongly suggest that the ancestral arthropod had at least trichromatic vision with a UV pigment and two visible pigments. Thereafter, in each pancrustacean and chelicerate lineage, the opsin repertoire was reconstructed by gene losses, gene duplications, and function-altering amino acid substitutions, leading to evolution of color vision.

  10. Late stages in the development of folds as deduced from model experiments

    NASA Astrophysics Data System (ADS)

    Dubey, Ashok Kumar

    1980-06-01

    A vein pattern around Bude, England, provides evidence that there has been a change in the direction of bulk extension during progressive development of folds. In the early history of fold development the direction of maximum extension was parallel to the axial surfaces of the folds and normal to the fold hinge whilst during the later stages of fold development the direction of maximum extension was along the fold hinge lines. An attempt has been made to understand the geometric evolution of such folds by performing experiments with plasticine models in the laboratory. Multilayer models were subjected to large deformation and late stages in the folding process have been observed. The experiments also show the effect of surfaces of décollment on fold geometry and the development of second order folds.

  11. Requirements for a marine geoid compatible with geoid deducible from satellite altimetry

    NASA Technical Reports Server (NTRS)

    Fubara, D. M. J.; Mourad, A. G.

    1972-01-01

    Theory deficiencies, data, and potential computational procedures that make the physical determination of the ocean geoid with true scale, shape, and absolute orientation of an elusive target are outlined. Satellite altimetry potential, in combination with adequate ground support and sea truth to resolve accurate global marine geoid and other peripheral benefits associated with ocean physics, are stated. Results are given in tabular form.

  12. Using a Mach-Zehnder interferometer to deduce nitrogen density mapping

    NASA Astrophysics Data System (ADS)

    Boudaoud, F.; Lemerini, M.

    2015-07-01

    This work presents an optical method using the Mach-Zehnder interferometer. We especially diagnose a pure nitrogen gas subjected to a point to plane corona discharge, and visualize the density spatial map. The interelectrode distance equals 6 mm and the variation of the optical path has been measured at different pressures: 220 Torr, 400 Torr, and 760 Torr. The interferograms are recorded with a CCD camera, and the numerical analysis of these interferograms is assured by the inverse Abel transformation. The nitrogen density is extracted through the Gladstone-Dale relation. The obtained results are in close agreement with values available in the literature.

  13. Shallow structure and recent evolution of the Aegean Sea deduced from the seismic reflection analysis

    SciTech Connect

    Laure, M.; Mascle, J.

    1988-08-01

    Together with the Tyrrhenian Sea, the Aegean Sea represents one of two marine basins still developing as a consequence of the subduction of the African lithosphere beneath Europe. Despite many geophysical similarities with the Tyrrhenian Sea, the Aegean displays a specific structural segmentation characterized by two distinct domains separated by the central Aegean. To the north of the basin, the so-called North Aegean trough likely represents the western marine extension of the transtensive Anatolian transform fault zone. The northern margin of this area contains a series of disconnected, often thickly sedimented small basins that probably initiated during the late Miocene as a consequence of a dominantly north-south extension; typical uppermost Miocene (Messinian) formations can be observed on seismic grounds. To the south, the Cretan Sea shows clear evidence of important distensive events occurring during two main episodes and following two main trends; a dominantly north-south-directed extension is responsibile for most of the structural features detected along both the Cretan and southern Cyclades margins.

  14. Use of pharmacologic antagonists to deduce commonalities of biologic activity among clostridial neurotoxins.

    PubMed

    Simpson, L L

    1988-06-01

    The pharmacologic activity of several clostridial neurotoxins was assayed on the mouse phrenic nerve-hemidiaphragm preparation. The substances that were assayed included botulinum neurotoxin types A, B, C and E and tetanus toxin. Experiments were done in the presence or absence of antagonists that inhibit either the internalization of toxins or intracellular expression of toxicity. Ammonium chloride and methylamine hydrochloride, agents that inhibit toxins that enter cells by receptor-mediated endocytosis, antagonized botulinum and tetanus neurotoxins. The magnitude of antagonism was substantial for all toxins. Calcium, 3,4-diaminopyridine and guanidine, agents that alter the intracellular expression of toxicity, produced a variable result. They were effective antagonists of botulinum neurotoxin type A, but they were less effective or inactive against the other neurotoxins. The ability of 3,4-diaminopyridine and guanidine to antagonize botulinum neurotoxin type A was highly calcium dependent. When ambient levels of the cation were reduced from 1.8 to 1.0 mM, the activity of the drugs was substantially reduced. The ability of these drugs to produce antagonism was also time dependent. When added simultaneously with toxin, they were maximally active; when added at later times, activity was diminished. A host of agents that alter intracellular levels of cyclic AMP, including theophylline, forskolin, isobutylmethylxanthine and cholera toxin, were evaluated as potential neurotoxin antagonists. Theophylline and isobutylmethylxanthine produced a transient increase in nerve-evoked muscle twitch. None of the drugs that alter tissue levels of cyclic AMP had a universal effect in antagonizing clostridial toxins. The data here have been compared with published data on drugs that antagonize binding of botulinum toxin and tetanus toxin.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2455038

  15. Constructing a folding model for protein S6 guided by native fluctuations deduced from NMR structures

    NASA Astrophysics Data System (ADS)

    Lammert, Heiko; Noel, Jeffrey K.; Haglund, Ellinor; Schug, Alexander; Onuchic, José N.

    2015-12-01

    The diversity in a set of protein nuclear magnetic resonance (NMR) structures provides an estimate of native state fluctuations that can be used to refine and enrich structure-based protein models (SBMs). Dynamics are an essential part of a protein's functional native state. The dynamics in the native state are controlled by the same funneled energy landscape that guides the entire folding process. SBMs apply the principle of minimal frustration, drawn from energy landscape theory, to construct a funneled folding landscape for a given protein using only information from the native structure. On an energy landscape smoothed by evolution towards minimal frustration, geometrical constraints, imposed by the native structure, control the folding mechanism and shape the native dynamics revealed by the model. Native-state fluctuations can alternatively be estimated directly from the diversity in the set of NMR structures for a protein. Based on this information, we identify a highly flexible loop in the ribosomal protein S6 and modify the contact map in a SBM to accommodate the inferred dynamics. By taking into account the probable native state dynamics, the experimental transition state is recovered in the model, and the correct order of folding events is restored. Our study highlights how the shared energy landscape connects folding and function by showing that a better description of the native basin improves the prediction of the folding mechanism.

  16. Structural Investigations of Afghanistan Deduced from Remote Sensing and Potential Field Data

    NASA Astrophysics Data System (ADS)

    Saibi, Hakim; Azizi, Masood; Mogren, Saad

    2016-08-01

    This study integrates potential gravity and magnetic field data with remotely sensed images and geological data in an effort to understand the subsurface major geological structures in Afghanistan. Integrated analysis of Landsat SRTM data was applied for extraction of geological lineaments. The potential field data were analyzed using gradient interpretation techniques, such as analytic signal (AS), tilt derivative (TDR), horizontal gradient of the tilt derivative (HG-TDR), Euler Deconvolution (ED) and power spectrum methods, and results were correlated with known geological structures. The analysis of remote sensing data and potential field data reveals the regional geological structural characteristics of Afghanistan. The power spectrum analysis of magnetic and gravity data suggests shallow basement rocks at around 1 to 1.5 km depth. The results of TDR of potential field data are in agreement with the location of the major regional fault structures and also the location of the basins and swells, except in the Helmand region (SW Afghanistan) where many high potential field anomalies are observed and attributed to batholiths and near-surface volcanic rocks intrusions. A high-resolution airborne geophysical survey in the data sparse region of eastern Afghanistan is recommended in order to have a complete image of the potential field anomalies.

  17. Volatile and lithophile trace-element geochemistry of Mexican tin rhyolite magmas deduced from melt inclusions

    NASA Astrophysics Data System (ADS)

    Webster, James D.; Burt, Donald M.; Aguillon, R. A.

    1996-09-01

    We have investigated the petrology and geochemistry of whole rocks from two small-volume, Sn- and F-mineralized rhyolitec dome complexes of the Mexican tin rhyolite belt, Cerro el Lobo and Cerro el Pajaro, to determine volcanic degassing and mineralizing processes in felsic igneous systems. The abundance and distribution of volatiles (H2O, B, F, and Cl) and lithophile trace and ore elements (Li, Rb, Cs, Be, Sr, Y, Ce, Th, U, Nb, Sn, and Mo) in the parental liquids were established by analyzing melt inclusions in quartz. The melt inclusions from both rhyolites are variably enriched in Li and the volatile constituents F and Cl, and some are extremely enriched in Li, although whole rocks are not correspondingly enriched. Compositional variations in the melt inclusions from both rhyolites also constrain magmatic differentiation. Melt evolution was dominated by crystal fractionation, modified by mass transport in a Cl- and H2O-rich magmatic-hydrothermal fluid, and resulted in increasing abundances of U, Nb, and Cs (± Li, F, Cl, B, Y, Ce, Be, Rb, Mo, and Sn) in both liquids. The rhyolite liquids apparently were heterogeneous prior to eruption. The Cerro el Lobo liquid contained gradients in volatiles and trace elements; comparatively less Cl, Be, B, Al2O3, and CaO (± Li, F, U, and Th) were present in the early-erupted, H2O-rich fractions of liquid. Comparing compositions of whole rocks with the mean compositions of melt inclusions constrains relative mobilities of magmatic constituents during and after eruption. Sodium, fluorine, lithium, uranium, and yttrium (± H2O, Cl, Sn) were lost from both magmas and the Cerro el Pajaro magma apparently also lost Nb and Al as a result of eruptive and posteruptive degassing. These geochemical relationships and constraints on pre-eruptive abundances and distributions of volatiles in tin rhyolite magmas probably apply to other tin rhyolites and, moreover, the high levels of Cl and Li enrichment maybe representative of other highly-evolved granitic magmas genetically associated with lithophile mineralization.

  18. The rarity of soft gamma-ray repeaters deduced from reactivation of SGR1806-20

    NASA Technical Reports Server (NTRS)

    Kouveliotou, C.; Fishman, G. J.; Meegan, C. A.; Paciesas, W.S.; Paradijs, J. Van; Norris, J. P.; Preece, R. D.; Briggs, M. S.; Horack, J. M.; Pendleton, G. N.; Green, D.A.

    1994-01-01

    Only two different types of gamma-ray transient sources are presently known: over one thousand Gamma-Ray Bursters (GRBs) and only three Soft Gamma-Ray repeaters (SGRs). The latter are distinguished by their propensity for recurrent burst behaviour, in contrast to the nonrepeating GRB sources. Recurrent emission from one of the repeaters, SGR1900 + 14, has been detected earlier by the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray Observatory. Here we report renewed burst activity from SGR1806 - 20, the most prolific of the three known SGRs. This detection of reactivation of this source has been rapidly followed by identification of an X-ray counterpart, which also coincides with a compact radio source now identified as a plerionic (pulsar-powered) supernova remnant. In combination, these results are leading to a convergence of ideas about the nature of SGRs, which can now be firmly identified as neutron stars. That BATSE has detected no new sources in its two and a half years of operation indicates that SGRs are rare in our Galaxy.

  19. Phase lag deduced information in photo-thermal actuation for nano-mechanical systems characterization

    SciTech Connect

    Bijster, R. J. F. Vreugd, J. de; Sadeghian, H.

    2014-08-18

    In photo-thermal actuation, heat is added locally to a micro-cantilever by means of a laser. A fraction of the irradiation is absorbed, yielding thermal stresses and deformations in the structure. Harmonic modulation of the laser power causes the cantilever to oscillate. Moreover, a phase lag is introduced which is very sensitive to the spot location and the cantilever properties. This phase lag is theoretically predicted and experimentally verified. Combined with thermo-mechanical properties of the cantilever and its geometry, the location of the laser spot, the thermal diffusivity, and the layer thicknesses of the cantilever can be extracted.

  20. Lower mantle thermal structure deduced from seismic tomography, mineral physics and numerical modelling

    NASA Technical Reports Server (NTRS)

    Cadek, O.; Yuen, D. A.; Steinbach, V.; Chopelas, A.; Matyska, C.

    1994-01-01

    The long-wavelength thermal anomalies in the lower mantle have been mapped out using several seismic tomographic models in conjunction with thermodynamic parameters derived from high-pressure mineral physics experiments. These parameters are the depth variations of thermal expansivity and of the proportionality factor between changes in density and seismic velocity. The giant plume-like structures in the lower mantle under the Pacific Ocean and Africa have outer fringes with thermal anomalies around 300-400 K, but very high temperatures are found in the center of the plumes near the base of the core-mantle boundary. These extreme values can exceed +1500 K and may reflect large hot thermal anomalies in the lower mantle, which are supported by recent measurements of high melting temperatures of perovskite and iron. Extremely cold anomalies, around -1500 K, are found for anomalies in the deep mantle around the Pacific rim and under South America. Numerical simulations show that large negative thermal anomalies in the mid-lower mantle have modest magnitudes of around -500 K. correlation pattern exists between the present-day locations of cold masses in the lower mantle and the sites of past subduction since the Cretaceous. Results from correlation analysis show that the slab mass-flux in the lower mantle did not conform to a steady-state nature but exhibited time-dependent behavior.

  1. Structural and temporal requirements for geomagnetic field reversal deduced from lava flows.

    PubMed

    Singer, Brad S; Hoffman, Kenneth A; Coe, Robert S; Brown, Laurie L; Jicha, Brian R; Pringle, Malcolm S; Chauvin, Annick

    2005-03-31

    Reversals of the Earth's magnetic field reflect changes in the geodynamo--flow within the outer core--that generates the field. Constraining core processes or mantle properties that induce or modulate reversals requires knowing the timing and morphology of field changes that precede and accompany these reversals. But the short duration of transitional field states and fragmentary nature of even the best palaeomagnetic records make it difficult to provide a timeline for the reversal process. 40Ar/39Ar dating of lavas on Tahiti, long thought to record the primary part of the most recent 'Matuyama-Brunhes' reversal, gives an age of 795 +/- 7 kyr, indistinguishable from that of lavas in Chile and La Palma that record a transition in the Earth's magnetic field, but older than the accepted age for the reversal. Only the 'transitional' lavas on Maui and one from La Palma (dated at 776 +/- 2 kyr), agree with the astronomical age for the reversal. Here we propose that the older lavas record the onset of a geodynamo process, which only on occasion would result in polarity change. This initial instability, associated with the first of two decreases in field intensity, began approximately 18 kyr before the actual polarity switch. These data support the claim that complete reversals require a significant period for magnetic flux to escape from the solid inner core and sufficiently weaken its stabilizing effect. PMID:15800621

  2. Structural Insights into the Role of Architectural Proteins in DNA Looping Deduced from Computer Simulations

    PubMed Central

    Olson, Wilma K.; Grosner, Michael A.; Czapla, Luke; Swigon, David

    2013-01-01

    Bacterial gene expression is regulated by DNA elements that often lie far apart along the genomic sequence but come close together during genetic processing. The intervening residues form loops, which are organized by the binding of various proteins. For example, the Escherichia coli Lac repressor protein binds DNA operators, separated by 92 or 401 base pairs, and suppresses the formation of gene products involved in the metabolism of lactose. The system also includes several highly abundant architectural proteins, such as the histone-like (heat unstable) HU protein, which severely deform the double helix upon binding. In order to gain a better understanding of how the naturally stiff DNA double helix forms the short loops detected in vivo, we have developed new computational methods to study the effects of various non-specifically binding proteins on the three-dimensional configurational properties of DNA sequences. This article surveys the approach that we use to generate ensembles of spatially constrained protein-decorated DNA structures (minicircles and Lac repressor-mediated loops) and presents some of the insights gained from the correspondence between computation and experiment about the potential contributions of architectural and regulatory proteins to DNA looping and gene expression. PMID:23514154

  3. The verification of lightning location accuracy in Finland deduced from lightning strikes to trees

    NASA Astrophysics Data System (ADS)

    Mäkelä, Antti; Mäkelä, Jakke; Haapalainen, Jussi; Porjo, Niko

    2016-05-01

    We present a new method to determine the ground truth and accuracy of lightning location systems (LLS), using natural lightning strikes to trees. Observations of strikes to trees are being collected with a Web-based survey tool at the Finnish Meteorological Institute. Since the Finnish thunderstorms tend to have on average a low flash rate, it is often possible to identify from the LLS data unambiguously the stroke that caused damage to a given tree. The coordinates of the tree are then the ground truth for that stroke. The technique has clear advantages over other methods used to determine the ground truth. Instrumented towers and rocket launches measure upward-propagating lightning. Video and audio records, even with triangulation, are rarely capable of high accuracy. We present data for 36 quality-controlled tree strikes in the years 2007-2008. We show that the average inaccuracy of the lightning location network for that period was 600 m. In addition, we show that the 50% confidence ellipse calculated by the lightning location network and used operationally for describing the location accuracy is physically meaningful: half of all the strikes were located within the uncertainty ellipse of the nearest recorded stroke. Using tree strike data thus allows not only the accuracy of the LLS to be estimated but also the reliability of the uncertainty ellipse. To our knowledge, this method has not been attempted before for natural lightning.

  4. Decadal variability in core surface flows deduced from geomagnetic observatory monthly means

    NASA Astrophysics Data System (ADS)

    Whaler, K. A.; Olsen, N.; Finlay, C. C.

    2016-07-01

    Monthly means of the magnetic field measurements at ground observatories are a key data source for studying temporal changes of the core magnetic field. However, when they are calculated in the usual way, contributions of external (magnetospheric and ionospheric) origin may remain, which make them less favourable for studying the field generated by dynamo action in the core. We remove external field predictions, including a new way of characterising the magnetospheric ring current, from the data and then calculate revised monthly means using robust methods. The geomagnetic secular variation (SV) is calculated as the first annual differences of these monthly means, which also removes the static crustal field. SV time series based on revised monthly means are much less scattered than those calculated from ordinary monthly means, and their variances and correlations between components are smaller. On the annual to decadal timescale, the SV is generated primarily by advection in the fluid outer core. We demonstrate the utility of the revised monthly means by calculating models of the core surface advective flow between 1997 and 2013 directly from the SV data. One set of models assumes flow that is constant over three months; such models exhibit large and rapid temporal variations. For models of this type, less complex flows achieve the same fit to the SV derived from revised monthly means than those from ordinary monthly means. However, those obtained from ordinary monthly means are able to follow excursions in SV that are likely to be external field contamination rather than core signals. Having established that we can find models that fit the data adequately, we then assess how much temporal variability is required. Previous studies have suggested that the flow is consistent with torsional oscillations (TO), solid body-like oscillations of fluid on concentric cylinders with axes aligned along the Earth's rotation axis. TO have been proposed to explain decadal timescale changes in the length-of-day. We invert for flow models where the only temporal changes are consistent with TO, but such models have an unacceptably large data misfit. However, if we relax the TO constraint to allow a little more temporal variability, we can fit the data as well as with flows assumed constant over three months, demonstrating that rapid SV changes can be reproduced by rather small flow changes. Although the flow itself changes slowly, its time derivative can be locally (temporally and spatially) large, in particular when and where core surface secular acceleration peaks. Spherical harmonic expansion coefficients of the flows are not well resolved, and many of them are strongly correlated. Averaging functions, a measure of our ability to determine the flow at a given location from the data distribution available, are poor approximations to the ideal, even when centred on points of the core surface below areas of high observatory density. Both resolution and averaging functions are noticeably worse for the toroidal flow component, which dominates the flow, than the poloidal flow component, except around the magnetic equator where averaging functions for both components are poor.

  5. Miocene to present-day shortening and intermontane basin formation in the Andean Puna Plateau, NW Argentina (24°30'S)

    NASA Astrophysics Data System (ADS)

    Strecker, M. R.; Bookhagen, B.; Alonso, R. N.; Pingel, H.; Freymark, J.

    2015-12-01

    With average elevations of about 3.7 km the Altiplano-Puna Plateau of the southern central Andes constitutes the world's second largest orogenic plateau. The plateau generally consists of internally drained, partly coalesced sedimentary basins bordered by reverse-fault bounded ranges, >5 km high. In the Puna, the Argentine sector of the plateau, active tectonism has been interpreted to be characterized by a low level of strike-slip and normal faulting associated with mafic volcanism. In contrast, the eastern plateau margins and the adjacent foreland record a higher level of seismicity and ongoing contraction. Despite ubiquitous Plio-Pleistocene normal faulting along the eastern plateau margins, our new observations record contraction in the plateau interior. Fanning of E-dipping Miocene sedimentary strata involved in the formation of an anticline in the Pocitos Basin of the central Puna interior indicates growth, which must have begun after 7 Ma; 1.5-m.y.-old lacustrine strata as well as tilted Pleistocene lacustrine shorelines associated with this structure indicate sustained uplift into the Quaternary. Corresponding observations along the eastern border of the Pocitos Basin show that <3.5-m.y.-old strata are involved in contractile deformation and basin compartmentalization. Shortening in the central Puna is compatible with Plio-Pleistocene shortening in the low-elevation Salar de Atacama farther west, and may indicate that low-elevation sectors of the plateau have not yet reached a critical elevation that is conducive to normal faulting as observed elsewhere. The onset of extensional deformation in the Puna is thus highly disparate in space and time. Coeval regional thrusting, strike-slip, and normal faulting do not support a structural and topographic setting that promotes wholesale extension and orogenic collapse of the plateau realm.

  6. In your 20s it's quantity, in your 30s it's quality: the prognostic value of social activity across 30 years of adulthood.

    PubMed

    Carmichael, Cheryl L; Reis, Harry T; Duberstein, Paul R

    2015-03-01

    Social connection, a leading factor in the promotion of health, well-being, and longevity, requires social knowledge and the capacity to cultivate intimacy. Life span development theorists have speculated that social information-seeking goals, emphasized at the beginning of early adulthood, give way to emotional closeness goals in later stages of early adulthood. Drawing on developmental theory (Baltes & Carstensen, 2003; Baltes, 1997), this 30-year prospective study assessed social activity at age 20 and age 30 with experience sampling methods, and psychosocial outcomes (social integration, friendship quality, loneliness, depression, and psychological well-being) at age 50. Results supported the hypothesis that the quantity (but not the quality) of social interactions at age 20, and the quality (but not the quantity) of social interactions at age 30 predict midlife psychosocial outcomes. Longitudinal structural models revealed that age-20 interaction quantity had a direct, unmediated effect on age-50 social and psychological outcomes. The effects of age-20 interaction quality on midlife outcomes, on the other hand, were mediated by age-30 interaction quality. Our findings are consistent with the idea that selection and optimization serve important functions in early adulthood, and that engaging in developmentally appropriate social activity contributes to psychosocial adjustment in the decades that follow.

  7. Paleomagnetism in the Precordillera of northern Chile (22°30'S): implications for the history of tectonic rotations in the Central Andes

    NASA Astrophysics Data System (ADS)

    Somoza, Rubén; Tomlinson, Andrew

    2002-01-01

    Widespread clockwise rotations in Mesozoic and Lower Tertiary rocks of northern Chile have been interpreted as the sum of two rotational events separated in time: an early rotation related to local deformation plus a late rotation related to wholesale rotation of northern Chile linked to Late Cenozoic oroclinal bending in the Central Andes. In this paper we report new paleomagnetic data from Cretaceous, upper Oligocene and Miocene sedimentary rocks in the Precordillera of northern Chile. The results suggest that all these rocks acquired their remanence at or close to the time of deposition. The lack of rotation in undeformed lower Miocene strata clearly indicates that clockwise rotations found in underlying, faulted and folded Cretaceous rocks were completed before the Late Cenozoic. Results from nearby localities in deformed upper Oligocene strata would argue for little (˜5°) rotation since the late Oligocene. Data from widely separated Miocene localities covering an area of about 5000 km 2 in the Calama basin strongly suggest that northern Chile did not undergo significant wholesale rotation during the Late Cenozoic. This, together with previous paleomagnetic evidence against Neogene rigid-body-like rotation of the southern Peruvian forearc, suggests that the curved shape of the Central Andean forearc was not significantly enhanced during the Late Cenozoic. By inference, all of the rotation in most Mesozoic and Lower Tertiary rocks of northern Chile was accomplished in the Cretaceous and/or Early Cenozoic, when the locus of deformation in the Central Andes was localized in the present forearc region.

  8. Quinine, Malaria, and the Cinchona Bureau: Marketing Practices and Knowledge Circulation in a Dutch Transoceanic Cinchona-Quinine Enterprise (1920s-30s).

    PubMed

    Van Der Hoogte, Arjo Roersch; Pieters, Toine

    2016-04-01

    In this study, we will show how a Dutch pharmaceutical consortium of cinchona producers and quinine manufacturers was able to capitalize on one of the first international public health campaigns to fight malaria, thereby promoting the sale of quinine, an antimalarial medicine. During the 1920s and 1930s, the international markets for quinine were controlled by this Dutch consortium, which was a transoceanic cinchona-quinine enterprise centered in the Cinchona Bureau in the Netherlands. We will argue that during the interwar period, the Cinchona Bureau became the decision-making center of this Dutch cinchona-quinine pharmaceutical enterprise and monopolized the production and trade of an essential medicine. In addition, we will argue that capitalizing on the international public health campaign in the fight against malaria by the Dutch cinchona-quinine enterprise via the Cinchona Bureau can be regarded as an early example of corporate colonization of public health by a private pharmaceutical consortium. Furthermore, we will show how commercial interests prevailed over scientific interests within the Dutch cinchona-quinine consortium, thus interfering with and ultimately curtailing the transoceanic circulation of knowledge in the Dutch empire.

  9. Geochemical and Sr-Nd-Pb-O isotope composition of granitoids of the Early Cretaceous Copiapó plutonic complex (27°30'S), Chile

    NASA Astrophysics Data System (ADS)

    Marschik, Robert; Fontignie, Denis; Chiaradia, Massimo; Voldet, Pia

    2003-10-01

    Early Cretaceous plutonic rocks exposed south of Copiapó form part of the Coastal Batholith of northern Chile. These rocks intrude arc-derived volcanic and volcaniclastic rocks and marine limestones that were deposited in the Early Cretaceous Atacama backarc basin. The Copiapó plutonic complex consists mainly of calc-alkaline, medium- to coarse-grained diorite, granodiorite, tonalite, monzodiorite, and quartz monzonite. The plutonic rocks are subalkaline to alkaline, metaluminous, magnetite-series, volcanic arc, I-type granitoids. Batholithic magmas are a heat, potential fluid, metal, and sulphur source for the hydrothermal iron oxide-rich Cu-Au mineralization in the Candelaria-Punta del Cobre district. Ore-related hydrothermal alteration affected large portions of the Copiapó complex. The least altered batholithic rocks have initial 87Sr/ 86Sr of 0.703070-0.703231; initial 143Nd/ 144Nd of 0.512733-0.512781; and 206Pb/ 204Pb, 207Pb/ 204Pb, and 208Pb/ 204Pb of 18.428-18.772, 15.550-15.603, and 38.127-38.401, respectively. The δ18O values for these rocks range from +6.9 to +8.6‰. Isotope signatures and trace element distributions suggest that the magmas are mantle derived. A subduction fluid-modified mantle source may explain the geochemical characteristics of the Copiapó complex. The ascent of magmas occurred along deep-rooted structures without significant crustal contamination, though minor contamination by relatively young (e.g. Jurassic) igneous rocks during ascent is possible. Intrusive rocks with high-K to shoshonitic characteristics probably represent residual liquids of less evolved magmas. The regional geologic context suggests that the plutons of the Copiapó complex were emplaced at a relatively shallow crustal level of 2-3 km.

  10. In Your 20s it’s Quantity, in Your 30s it’s Quality: The Prognostic Value of Social Activity Across 30 Years of Adulthood

    PubMed Central

    Carmichael, Cheryl L.; Reis, Harry T.; Duberstein, Paul R.

    2015-01-01

    Social connection, a leading factor in the promotion of health, well-being, and longevity, requires social knowledge and the capacity to cultivate intimacy. Lifespan development theorists have speculated that social information-seeking goals, emphasized at the beginning of early adulthood, give way to emotional closeness goals in later stages of early adulthood. Drawing on developmental theory (Baltes, 1997; Baltes & Carstensen, 2003), this 30-year prospective study assessed social activity at age-20 and age-30 with experience sampling methods, and psychosocial outcomes (social integration, friendship quality, loneliness, depression, and psychological well-being) at age-50. Results supported the hypothesis that the quantity (but not the quality) of social interactions at age-20, and the quality (but not the quantity) of social interactions at age-30 predict midlife psychosocial outcomes. Longitudinal structural models revealed that age-20 interaction quantity had a direct, unmediated effect on age-50 social and psychological outcomes. The effects of age-20 interaction quality on midlife outcomes, on the other hand, were mediated by age-30 interaction quality. Our findings are consistent with the idea that selection and optimization serve important functions in early adulthood, and that engaging in developmentally appropriate social activity contributes to psychosocial adjustment in the decades that follow. PMID:25774426

  11. Elucidation of echovirus 30's origin and transmission during the 2012 aseptic meningitis outbreak in Guangdong, China, through continuing environmental surveillance.

    PubMed

    Lu, Jing; Zheng, Huanying; Guo, Xue; Zhang, Yong; Li, Hui; Liu, Leng; Zeng, Hanri; Fang, Ling; Mo, Yanling; Yoshida, Hiromu; Yi, Lina; Liu, Tao; Rutherford, Shannon; Xu, Wenbo; Ke, Changwen

    2015-04-01

    An aseptic meningitis outbreak occurred in Luoding City of Guangdong, China, in 2012, and echovirus type 30 (ECHO30) was identified as the major causative pathogen. Environmental surveillance indicated that ECHO30 was detected in the sewage of a neighboring city, Guangzhou, from 2010 to 2012 and also in Luoding City sewage samples (6/43, 14%) collected after the outbreak. In order to track the potential origin of the outbreak viral strains, we sequenced the VP1 genes of 29 viral strains from clinical patients and environmental samples. Sequence alignments and phylogenetic analyses based on VP1 gene sequences revealed that virus strains isolated from the sewage of Guangzhou and Luoding cities matched well the clinical strains from the outbreak, with high nucleotide sequence similarity (98.5% to 100%) and similar cluster distribution. Five ECHO30 clinical strains were clustered with the Guangdong environmental strains but diverged from strains from other regions, suggesting that this subcluster of viruses most likely originated from the circulating virus in Guangdong rather than having been more recently imported from other regions. These findings underscore the importance of long-term, continuous environmental surveillance and genetic analysis to monitor circulating enteroviruses.

  12. Lacustrine records of the June 2011 eruption of the Puyehue-Cordón Caulle Volcanic Complex, Central Chile (40°30'S, 72°10'W)

    NASA Astrophysics Data System (ADS)

    Daga, Romina; Bertrand, Sébastien; Bedert, Robin; Ribeiro Guevara, Sergio; Ghazoui, Zakaria

    2013-04-01

    Present volcanic eruptions offer unique opportunities to study the dispersion and spatial variability of volcanic deposits. The objective of this work is to assess lateral variations of pyroclastic deposits from the June 2011 volcanic eruption of Puyehue-Cordon Caulle Volcanic Complex (PCCVC) by analyzing the sedimentology and geochemistry of tephra layers deposited in different lakes situated in North Patagonia (Chile and Argentina), located along the main dispersion axis of the volcanic cloud. Short sediment cores were extracted from selected lakes in Chile and Argentina using a short Uwitec gravity corer; coarse tephra deposits were collected with a grab sampler. The sediment cores were opened, visually inspected, photographed and described, and the magnetic susceptibility was measured with a Bartington MS3 meter and MS2E sensor. Visual inspection included the identification of the 2011 tephra layer, and the description of colour, grain size, thickness, and sedimentary structures of the sedimentary sequence. Subsequent studies were focused on the tephra layers. Samples were freeze-dried for multi-proxy analyses, including bulk mineralogy analyzed by X-ray diffraction and bulk geochemical characterization by Instrumental Neutron Activation Analysis. In this presentation, the main characterization features of the pyroclastic products will be presented, together with dispersion patterns. Lacustrine tephra deposits clearly reflected the predominance of westerlies, with thin deposits on the Chilean side of the volcano, but much thicker and coarser tephra close to the volcano. Ash dispersion extended hundreds of kilometers towards the east of the volcano, i.e., in Argentinean territory. Tephras deposited in water bodies in Chile are mainly transported from the eruptive center by rivers and watercourses with headwaters located in the volcano area, whereas tephra deposits in Argentinean lakes mainly result from direct ash falls. We also observed in-lakes variations in the sedimentological properties of the 2011 tephra in large lakes located to the West (Lake Puyehue) and to the East (Lake Nahuel Huapi) of the PCCVC. The characterization and precise understanding of this very recent eruption, and the observations of distribution patterns associated to wind directions and precipitation effects help us understand the mechanisms responsible for tephra deposition in lakes. Ultimately, this study will provide important clues to interpret tephra records from longer sediment cores, and improve tephra correlations on longer distances.

  13. Age of the fossil Dali Man in north-central China deduced from chronostratigraphy of the loess?paleosol sequence

    NASA Astrophysics Data System (ADS)

    Xiao, Jule; Jin, Changzhu; Zhu, Yizhi

    2002-11-01

    Dali Man, an archaic type of early Homo sapiens, is of great significance to the origin of Homo sapiens. Achievements have been made during the past decades in the understanding of the fossil human skull as well as the accompanying mammalian fossils and stone artifacts. However, the absolute age of the fossil Dali Man still remains unclear. Based on the magnetic susceptibility of loess sediments and the relationship of terracing process with climatic condition, we correlated the loess sequence and the subjacent terrace alluvium at the Dali Man site with the well-studied loess-paleosol sequence at Luochuan in the central part of the Chinese Loess Plateau. The correlation indicates that the loess-paleosol sequence at the Dali Man site extends down to the paleosol S2, and the underlying fluvial deposits correspond to the loess L3. Because the Dali Man skull appears in the basal gravel layer of the terrace, and because the deposition of the terrace gravels would occur during the transition from S3 paleosol formation to L3 loess accumulation, the age of the fossil Dali Man is inferred to be ca 270 ka, which is equivalent to the age of the boundary between the loess L3 and paleosol S3 on the magnetic susceptibility time series of the Luochuan loess-paleosol sequence.

  14. Pulling Marbles from a Bag: Deducing the Regional Impact History of the SPA Basin from Impact-Melt Rocks

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara A.; Coker, Robert F.

    2010-01-01

    The South Pole Aitken (SPA) basin is the stratigraphically oldest identifiable lunar basin and is therefore one of the most important targets for absolute age-dating to help understand whether ancient lunar bombardment history smoothly declined or was punctuated by a cataclysm. A feasible near-term approach to this problem is to robotically collect a sample from near the center of the basin, where vertical and lateral mixing provided by post-basin impacts ensures that such a sample will be composed of small rock fragments from SPA itself, from local impact craters, and from faraway giant basins. The range of ages, intermediate spikes in the age distribution, and the oldest ages are all part of the definition of the absolute age and impact history recorded within the SPA basin.

  15. Pulling Marbles from a Bag: Deducing the Regional Impact History of the SPA Basin from Impact Melt Rocks

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara A.; Coker, R. F.

    2009-01-01

    The South Pole-Aitken (SPA) basin is an important target for absolute age-dating. Vertical and lateral impact mixing ensures that regolith within SPA will contain rock fragments from SPA itself, local impact craters, and faraway giant basins. About 20% of the regolith at any given site is foreign [1, 2], but much of this material will be cold ejecta, not impact melt. We calculated the fraction of contributed impact melt using scaling laws to estimate the amount and provenance of impact melt, demonstrating that SPA melt is the dominant impact melt rock (>70%) likely to be present. We also constructed a statistical model to illustrate how many randomly-selected impact-melt fragments would need to be dated, and with what accuracy, to confidently reproduce the impact history of a site. A detailed impact history becomes recognizable after a few hundred to a thousand randomly-selected marbles, however, it will be useful to have more information (e.g. compositional, mineralogical, remote sensing) to group fragments. These exercises show that SPA melt has a high probability of being present in a scoop sample and that dating of a few hundred to a thousand impact-melt fragments will yield the impact history of the SPA basin.

  16. Particulate Scavenging and Lateral Transport Processes in the Gaoping Submarine Canyon Deduced From Pb-210 and Po-210 Observations

    NASA Astrophysics Data System (ADS)

    Hung, G.; Wang, P.; Shen, Y.

    2009-05-01

    Pb-210 and Po-210 were measured on the suspended particulate matter(SPM) and filtered water samples collected in profile from five stations in the Gaoping Submarine Canyon (GPSC) during a cruise aboard R/V Ocean Researcher III in late November, 2006. These stations were selected along the axis of the GPSC, and denoted as CW1 through CW5 sequentially from the shallow part near the mouth of the Gaoping River to the deep-water region of the canyon. Except for CW4, the SPM profiles generally show a rapid increase to a maximum near bottom, the value of which is an order of magnitude higher than that observed above, suggesting a significant particulate resuspension or lateral input in the bottom layer. The SPM concentrations obtained at canyon head stations(CW1 to CW3) vary between 0.36 and 19.17 mg/kg. These values are generally higher than those obtained farther outward(CW4 and CW5), which range from 0.01 to 2.13 mg/kg, indicating a decrease away from the shore. The dissolved Pb-210 and Po-210 profiles observed from CW1 and CW2 are fairly uniform for the entire water column, with a mean of about 14 and 12 dpm/100kg, respectively. The other stations show a large variation in dissolved Pb-210 and Po-210 with a mean of about 23 and 14 dpm/100kg, respectively. At stations CW1, CW2 and CW3, the particulate Pb-210 and Po-210 profiles generally display a maximum around 28-38 and 27-48 dpm/100kg, respectively, in the bottom layer, suggesting significant particulate resuspension and scavenging. Variable Pb-210 and Po-210 activities in the particulates at CW4 and CW5 are observed in the surface layer. Both the dissolved and the total (dissolved + particulate) Po-210 to Pb-210 activity ratios vary between 0.1 and 1.7, mostly less than 1.0, with a mean of 0.7 and 0.8, indicating a variable deficiency of Po-210 relative to Pb- 210 in this study area. Total activities of Pb-210 are generally higher than those of Po-210. The Ra-226 profiles show much lower activities than those of the corresponding Pb-210 and Po-210, indicating large excesses of both Pb-210 and Po-210 over its parent , Ra-226. Assuming at steady-state, the mean residence times for the dissolved and particulate Pb-210 in the surface mixed layer are 0.6-1.3 and 0.8-3.9 years, respectively. The residence times of dissolved and particulate Po-210 are 0.4-2.6 and 0.1-0.4 years, respectively. The mean residence times are estimated to be on the order of days if advection terms are taken into account.

  17. Thermal history of the Pan-African/Brasiliano Borborema Province of northeast Brazil deduced from 40Ar/ 39Ar analysis

    NASA Astrophysics Data System (ADS)

    Corsini, M.; de Figueiredo, L. Lambert; Caby, R.; Féraud, G.; Ruffet, G.; Vauchez, A.

    1998-02-01

    Detailed step heating 40Ar/ 39Ar analyses were performed on different minerals from magmatic and metamorphic rocks of the Borborema Province. This region, located in northeast Brazil, belongs to the Pan-African/Brasiliano belt which is about 1000 km wide and 600 km long. Twenty-six single grains of amphibole, muscovite and biotite were extracted from eighteen samples selected in an area of about 17,500 km 2 (250 km by 70 km) in the Patos region. This region has been affected by a continental-scale shear zone system. Well-defined 40Ar/ 39Ar plateau ages and an U sbnd Pb analysis on zircon [Leterrier, J., Jardim de Sà, E.F, Bertrand, J.M. and Pin, C., 1994. Ages U sbnd Pb sur zircon de granitoïdes brasilianos de la ceinture du Serido (Province Borborema, NE brésil). C.R. Acad. Sci., Paris, 318: 1505-1511] allow the definition of a homogeneous and unusual slow cooling history (3-4°C/Ma) and suggest a rather slow uplift rate between 580 and 500 Ma, followed by a fast cooling of the whole studied area around 500 Ma. Rapid cooling is suggested by concordant plateau ages on muscovite and biotite. The existence of such an event at the end of the belt history is in agreement with data obtained on other major belts such as the Alpine-Himalayan system or the Hercynian belt.

  18. Evolution of multicellular animals as deduced from 5S rRNA sequences: a possible early emergence of the Mesozoa.

    PubMed Central

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S

    1984-01-01

    The nucleotide sequences of 5S rRNA from a mesozoan Dicyema misakiense and three metazoan species, i.e., an acorn-worm Saccoglossus kowalevskii, a moss-animal Bugula neritina, and an octopus Octopus vulgaris have been determined. A phylogenic tree of multicellular animals has been constructed from 73 5S rRNA sequences available at present including those from the above four sequences. The tree suggests that the mesozoan is the most ancient multicellular animal identified so far, its emergence time being almost the same as that of flagellated or ciliated protozoans. The branching points of planarians and nematodes are a little later than that of the mesozoan but are clearly earlier than other metazoan groups including sponges and jellyfishes. Many metazoan groups seem to have diverged within a relatively short period. PMID:6539911

  19. Single-Path Sigma and Spatial Correlation of Gmpe Residuals Deduced from a Huge Dataset in Taiwan

    NASA Astrophysics Data System (ADS)

    Sung, C. H.; Lee, C. T.; Gao, J. C.

    2014-12-01

    A strong ground-motion attenuation equation is an essential part in the probability seismic hazard analysis. Therefore, we need to study the strong ground-motion attenuation relationship for earthquakes in Taiwan. In this study, well processed strong ground-motion data from aiwan Strong Motion Instrumentation Program (TSMIP) in Taiwan are used to establish attenuation equations. A total of 158 earthquakes with 18,859 records are selected and nonlinear mixed-effect model with maximum likelihood method is used to accomplish the regression analysis of ground-motion attenuation relationships for peak ground acceleration (PGA), with considering earthquake source, distance, site condition (Vs30), fault mechanism, and tectonic regine. The very much concerned ground-motion variability in PSHA is reviewed and studied with huge amount of data from Taiwan. We analyzed aleatory variability firstly by direct observation on inter-event variability and site-specific variability, and then by two additional simple approaches, the variogram and the standard deviation distribution in single site stady and in single earthquake study and got spatial distribution of single-path sigma as well as their earthquake component and site component. The single-path sigma is ranging from 0.219 to 0.254. These are 58% to 64% smaller than the total sigma (0.601). If we only use aleatory variability in PSHA, then the resultant hazard level would be 20% lower than the traditional one in 2,475 year return-perid.

  20. A comprehensive model of postseismic deformation of the 2004 Sumatra-Andaman earthquake deduced from GPS observations in northern Sumatra

    NASA Astrophysics Data System (ADS)

    Gunawan, Endra; Sagiya, Takeshi; Ito, Takeo; Kimata, Fumiaki; Tabei, Takao; Ohta, Yusaku; Meilano, Irwan; Abidin, Hasanuddin Z.; Agustan; Nurdin, Irwandi; Sugiyanto, Didik

    2014-07-01

    We investigate the postseismic deformation of the 2004 Sumatra-Andaman earthquake (SAE) using 5 years of Global Positioning System (GPS) data located in northern Sumatra. Continuous GPS data from northern Sumatra suggest that the relaxation time in the vertical displacement is longer than horizontal displacements. This implies that there are multiple physical mechanisms that control the postseismic deformation, which refer to afterslip and viscoelastic relaxation. In this study, we introduce an analysis strategy of postseismic deformation to simultaneously calculate multiple mechanisms of afterslip and viscoelastic relaxation. The afterslip inversion results indicate that the distribution of the afterslip and the coseismic slip are compensatory of each other. Also, afterslip has a limited contribution to vertical deformation in northern Sumatra. In our rheology model, we use a gravitational Maxwell viscoelastic response and the result indicates that the elastic layer thickness is 65 ± 5 km and the Maxwell viscosity is 8.0 ± 1.0 × 1018 Pa s. We find that afterslip plus Maxwell viscoelastic relaxation are appropriate to explain the deformation in northern Sumatra. We also find that our rheology model reproduces the long-term features of the GPS time series in Thailand. Applying our rheology model to the data in Andaman Islands our afterslip estimation is located at the down-dip part of the plate boundary. Finally, we showed that our rheology model is applicable to the GPS datasets of postseismic deformation of the 2004 SAE located in northern Sumatra, Thailand, and Andaman-Nicobar, respectively.

  1. Evolution of multicellular animals as deduced from 5S rRNA sequences: a possible early emergence of the Mesozoa.

    PubMed

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S

    1984-06-25

    The nucleotide sequences of 5S rRNA from a mesozoan Dicyema misakiense and three metazoan species, i.e., an acorn-worm Saccoglossus kowalevskii, a moss-animal Bugula neritina, and an octopus Octopus vulgaris have been determined. A phylogenic tree of multicellular animals has been constructed from 73 5S rRNA sequences available at present including those from the above four sequences. The tree suggests that the mesozoan is the most ancient multicellular animal identified so far, its emergence time being almost the same as that of flagellated or ciliated protozoans. The branching points of planarians and nematodes are a little later than that of the mesozoan but are clearly earlier than other metazoan groups including sponges and jellyfishes. Many metazoan groups seem to have diverged within a relatively short period.

  2. Two millennia of forest history deduced from closed depressions in the Lorrain plain (North-eastern, France)

    NASA Astrophysics Data System (ADS)

    Etienne, David; Ruffaldi, Pascale; Ritz, Frederic; Dupouey, Jean Luc; Dambrine, Etienne

    2010-05-01

    Recent archaeological surveys and ecological investigations in large "ancient" forests have shown that these areas had been often cultivated during the Roman or Medieval periods, and that this former land use is still deeply influencing present soil properties and plant biodiversity. This new perspective has boosted the research for sediment archives describing the state of forests across the archaeological and historical periods, especially in low altitude forest. Closed depressions (CD) or small hollows (over 30 000 CDs) are found in many silty plains of North-Western Europe (north-eastern France, Luxemburg and Belgium). They are defined as small (100 to 400 m²) closed wetlands, mostly supplied by rainwater. Their origin is debated. Recent coring campaigns in CDs of Lorraine (north-eastern France), 3 to 5 meters thick sediment cores were retrieved. It opened the way for palynological and pedological reconstruction of former landscapes. Here we present a sediment analysis of four peaty CDs (Assenoncourt, Römersberg, Sarrebourg and St Jean), located in different low altitude beech (Fagus) and oak (Quercus) forests, on silty clay soils, 50km from Nancy. As the oldest available map (Naudins, dated from 1728 to 1739) indicated forest boundaries similar to the present ones, these forests were considered as ancient forests. The sedimentation begins during the second Iron Age or Roman period. By this time, pollen analyses show an open landscape (70% of Non Arboreal Pollen), composed mostly by grassland (Plantago major/media, Poaceae and Asteraceae) and cropland (Cerealia-type, Centaurea cyanus). Around the 5th century AD, coinciding with the collapse of the Roman Empire, the pollen sequences describe rapid afforestation by Betula and Corylus, and later Carpinus forest. From the 8th century AD, Carpinus decreases in favour of Quercus which may reflect an anthropogenic clearing. From the 10th to the 14th century AD, croplands expand again with cultivation of hemp (Cannabis-type) and rye (Secale-type). From the 15th to the 19th century AD, pollen diagrams are similar at three sites and differ from the fourth. At Assenoncourt, St Jean and Römersberg, the contribution of Quercus, Carpinus and Fagus remains almost constant: 40%, 10% and 10%. This pattern may be related to short rotation forestry management applied in order to provide fuel wood to the local salt industry. At the fourth site (Sarrebourg), pollen assemblage varies with successive Quercus and Carpinus phases, following a natural sylvicultural evolution. Finally, the present-day forest extension took place during the 19th century with the replacement of wood by coal in the salt industry and the recent collapse of this salt industry during the 20th century. This study confirms, in the context of low altitude forests with heavy soils, what had been observed on shallow calcareous soils of the Lorrain plateau. Most of our state forests, that were thought to be "very ancient" or "immemorial" forest, have been managed for agriculture in the deep past. Because agriculture lands were often limed, fertilized, and eroded, this former agriculture use may to a large extent explain present soil properties and, as a consequence, present biodiversity.

  3. Probabilistic Appraisal of Earthquake Hazard Parameters Deduced from a Bayesian Approach in the Northwest Frontier of the Himalayas

    NASA Astrophysics Data System (ADS)

    Yadav, R. B. S.; Tsapanos, T. M.; Bayrak, Yusuf; Koravos, G. Ch.

    2013-03-01

    A straightforward Bayesian statistic is applied in five broad seismogenic source zones of the northwest frontier of the Himalayas to estimate the earthquake hazard parameters (maximum regional magnitude M max, β value of G-R relationship and seismic activity rate or intensity λ). For this purpose, a reliable earthquake catalogue which is homogeneous for M W ≥ 5.0 and complete during the period 1900 to 2010 is compiled. The Hindukush-Pamir Himalaya zone has been further divided into two seismic zones of shallow ( h ≤ 70 km) and intermediate depth ( h > 70 km) according to the variation of seismicity with depth in the subduction zone. The estimated earthquake hazard parameters by Bayesian approach are more stable and reliable with low standard deviations than other approaches, but the technique is more time consuming. In this study, quantiles of functions of distributions of true and apparent magnitudes for future time intervals of 5, 10, 20, 50 and 100 years are calculated with confidence limits for probability levels of 50, 70 and 90 % in all seismogenic source zones. The zones of estimated M max greater than 8.0 are related to the Sulaiman-Kirthar ranges, Hindukush-Pamir Himalaya and Himalayan Frontal Thrusts belt; suggesting more seismically hazardous regions in the examined area. The lowest value of M max (6.44) has been calculated in Northern-Pakistan and Hazara syntaxis zone which have estimated lowest activity rate 0.0023 events/day as compared to other zones. The Himalayan Frontal Thrusts belt exhibits higher earthquake magnitude (8.01) in next 100-years with 90 % probability level as compared to other zones, which reveals that this zone is more vulnerable to occurrence of a great earthquake. The obtained results in this study are directly useful for the probabilistic seismic hazard assessment in the examined region of Himalaya.

  4. Storm-induced changes of the topside ionosphere as deduced from incoherent-scatter radars. Master's thesis

    SciTech Connect

    Lunn, K.J.

    1990-01-01

    Incoherent scatter radar observations from Millstone Hill, Saint Santin, and Arecibo are used to illustrate changes of the topside ionosphere during a geomagnetic storm. These observations consist of electron density, electron and ion temperatures, and ion velocity components parallel and perpendicular to the magnetic field. These parameters can further describe changes in ion composition, electric fields, and neutral winds. Attention is given to a specific storm during the Equinox Transition Study (ETS) of September 1984. In order to isolate the storm effects in the topside ionosphere, a comparison will be made between a disturbed and quiet day. A novel result from this study is the finding of correlated oscillations between parallel and perpendicular ion velocity components which are apparently storm induced. Previously, these oscillations have been observed primarily at night, but now it's noticed that during storm conditions there are prominent oscillations during the day.

  5. Mantle flow deduced from geochemical variations in alkaline magmas of HIMU affinity from continent to ocean, northwestern Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Castillo, P. R.; Panter, K. S.; McIntosh, W. C.

    2011-12-01

    Cenozoic alkaline magmatism in the northwestern Ross Sea (NWRS) region has been recently expanded to include numerous volcanic seamounts on the continental shelf and hundreds more located within the oceanic Adare Basin [1]. The seamounts are Pliocene in age and petrogenetically akin to volcanism on land in the West Antarctic rift system. In general, trace element and Sr-Nd-Pb isotopic data resemble those from ocean islands with HIMU affinity. Apart from the well studied Cameroon volcanic line in West Africa, the NWRS is a unique setting for comparing contemporary alkaline volcanism bridging the transition from oceanic to thinned continental lithosphere adjacent to the thick East Antarctic craton. The geochemistry of NWRS basalts, extending to the northeast from the Mariner Glacier to the Adare Peninsula and into the Adare Basin (~168°E 73°S to ~173°E 70°S), shows a remarkable orderly increase in degree of silica-undersaturation, P2O5, Nb, Zr, Sr contents and La/Yb, Nb/Y, 143Nd/144Nd and 206Pb/204Pb ratios, coupled with a decrease in Ba/La and 87Sr/86Sr ratios, suggesting they were generated from a common heterogeneous mantle source at progressively smaller melt fractions from land to sea. Geochemical variations coincide with northward age propagation in magmatism and southward increase in rifting since the middle Miocene [2]. We propose that the HIMU-like signature in both continental and oceanic sectors is derived from metasomatized lithosphere, whereby the most easily fusible components contribute to the smaller degree melts in greater proportions ocean-ward. Melting may have been triggered by influx of warm asthenosphere initially beneath the continent and then northward by edge-driven convection and channelized by focused extension [3] into the Adare Basin where the metasomatized source is more dispersed. [1] Panter & Castillo (2008) USGS Open-File Report 2007-1047, 069. [2] Granot et al. (2010) Geochem. Geophys. Geosyst. 11(8). [3] Huerta & Harry (2007) Earth Planet. Sci. Lett. 255.

  6. Structural evolution of lamprophyric dikes in Lailai, northeastern coast of Taiwan, deduced from mesoscopic structures in dikes and country rocks

    NASA Astrophysics Data System (ADS)

    You, Cian-Siang; Huang, Wen-Jeng; Lo, Wei; Wang, Tzu-Bin; Chen, Chien-Chih

    2015-04-01

    Lamprophyric dikes are standing in right-stepping en echelon up to 2.3 meters high within the Oligocene Tatungshan formation on the Lai-Lai wave-cut platform in the northeastern coast of Taiwan. The marine platform composed mainly of argillite is the extension of Hsuehshan range, which has the tallest peak of 3,886 m high in Taiwan. The dikes formed at depth in the late Miocene of 9±1.1 Ma ago are exposed on the marine platform nowadays due to the exhumation and Penglai orogeny resulting from the collision of Eurasian plate and Philippine Sea plate, which began in Pleistocene of 5-6 Ma ago. In consequence, folds, faults, joints and other structures are associated with them. In this study, the distribution of the dikes and fractures were mapped by conducting accurate surveys with a total station theodolite and orthorectifying aerial images taken by an unmanned aerial vehicle in different elevations. Electrical resistivity exploration was performed to decipher the arrangement of the dikes underground and the characteristics of the faults. The associated mesoscopic structures were delineated by mapping at a scale of 1: 40 in the field. We infer that the dikes was formed at depth of approximately 2.4 kilometers according to the thickness of overlaying sedimentary rocks formed from late Oligocene to late Miocene. Thus, it excludes the possibility that fractures existed before the lamprophyric magma intruded into the country rocks. Our observations help restore the original status of the current 19 dike segments. We conclude that the lamprophyric magma forcedly and vertically intruded into the Oligocene rocks and the direction change of maximum principle stress at depth of 2.4 kilometers resulted in three or more right-stepping en-echelon dikes.

  7. Sedimentary cover in the South Western Desert of Egypt as deduced from Bouguer gravity and drill-hole data

    NASA Astrophysics Data System (ADS)

    Senosy, M. M.; Youssef, M. M.; Abdel Zaher, M.

    2013-06-01

    The Western Desert, Egypt includes the major groundwater aquifer in the country. It is apart from the Major Sahara Nubian Aquifer which is present in Sudan, Chad, Egypt and Libya. Thickness of this aquifer is changed laterally from south to north and also from west to east. The changes may structurally or litheologicalley control. The present study is focused on using of Bouguer gravity anomaly mapped at a scale of 1:500,000 and the lithological logs of about 120 deep wells used to determine the thickness of the sedimentary sequence containing the main Nubian sandstone water aquifer in important area of Egypt. The area is located in the southern part of the Western Desert bounded by the latitudes 22°00'-26°30'N, and longitudes 28°30'-33°00'E. The predominant structures affecting the basement rocks and the sedimentary cover were traced and analyzed. The gravity stripping approach was applied to eliminate the gravity effects caused by sedimentary sequence and to separate density anomalies within the sedimentary fill from the influence of rocks at deeper levels in the crystalline crust. The study indicated that the surface of the basement rocks is highly rugged and mostly controlled by structures which have a direct effect on thickness variation of the sedimentary cover all over the area. Regionally the area is characterized by two major intracratonic basins (the Dahkla Basin and the Nile valley Basin) separated by a NE-SW trending swell of the Kharga uplift and bounded at the south by the Oweinat-Bir Safsaf-Aswan uplift. These major tectonic units are controlled by fault structures trending in N-S, E-W, NE-SW, NW-SE, which cut the basement rocks and extend upward in the sedimentary cover. The maximum thickness of sandstone formations is recorded at west Oweinat, west Kurkur, southwest of Aswan, Gramashin, Dakhla oasis and some localities west of Sohag and Qena towns. At these localities the thickness ranges between 600 and 900 m. As this formation is the main water aquifer in the study area, therefore these localities are characterized by the presence of big amount of ground water. Accordingly, these areas must take the priority in the sustainable development programs of southern Egypt.

  8. Deducing transmissivity from specific capacity in the heterogeneous upper aquifer system of Jifarah Plain, NW-Libya

    NASA Astrophysics Data System (ADS)

    Al Farrah, Nawal; Van Camp, Marc; Walraevens, Kristine

    2013-09-01

    The hydraulic characterisation of aquifer systems is important for the development of exploitation scenarios and management strategies. Especially in lithologically heterogeneous aquifers, local scale variations in transmissivity (T) may not be neglected. Field scale transmissivity values are usually derived from pumping tests, but in most cases their number and availability is rather limited. Therefore T values are often estimated from specific well capacities (SC) which can easily be measured in exploitation wells based on static and dynamic water levels. Empirical relations allow T to be calculated from SC values using a power law relation of the form T = A * SCN. In this paper this relation is investigated for three aquifers in north-west Lybia, using the results from step-drawdown tests which allow determination of well efficiencies, which can be incorporated into the regression analysis. The obtained fitting coefficients of the power law relations were compared with published values from other studies. Both parameters of the power law relation (scale factor and power coefficient) seem to be highly correlated following an exponential relationship (R2 = 0.89), reducing the T-SC relation to a single parameter equation, which is mainly related to lithology.

  9. Gravity anomalies and lithospheric flexure around the Longmen Shan deduced from combinations of in situ observations and EGM2008 data

    NASA Astrophysics Data System (ADS)

    She, Yawen; Fu, Guangyu; Wang, Zhuohua; Liu, Tai; Xu, Changyi; Jin, Honglin

    2016-10-01

    The current work describes the combined data of three field campaigns, spanning 2009-2013. Their joint gravity and GPS observations thoroughly cover the sites of lithospheric flexure between the Sichuan Basin and the Eastern Tibetan Plateau. The study area's free-air gravity anomalies (FGAs) are updated by using a remove-and-restore algorithm which merges EGM2008 data with in situ observations. These new FGAs show pairs of positive and negative anomalies along the eastern edges of the Tibetan Plateau. The FGAs are used to calculate effective elastic thickness ( T e) and load ratios ( F) of the lithosphere. Admittance analysis indicates the T e of Longmen Shan (LMS) to be 6 km, and profile analysis indicates that the T e of the Sichuan Basin excesses 30 km. The load ratio ( F 1 = 1) confirms that the lithospheric flexure of the LMS area can be attributed solely to the surface load of the crust. [Figure not available: see fulltext. Caption: The current work describes the combined data of three field campaigns, spanning 2009-2013. Their joint gravity and GPS observations thoroughly cover the sites of lithospheric flexure between the Sichuan Basin and the Eastern Tibetan Plateau. The study area's free-air gravity anomalies (FGAs) are updated by using a remove-and-restore algorithm which merges EGM2008 data with in situ observations. With the new FGAs data, the lithospheric strength of the study area is studied by the authors, and they also give a combined model to illustrate the uplift mechanism of this area.

  10. cDNA and deduced amino acid sequence of human pulmonary surfactant-associated proteolipid SPL(Phe)

    SciTech Connect

    Glasser, S.W.; Korfhagen, T.R.; Weaver, T.; Pilot-Matias, T.; Fox, J.L.; Whitsett, J.A.

    1987-06-01

    Hydrophobic surfactant-associated protein of M/sub r/ 6000-14,000 was isolated from either/ethanol or chloroform/methanol extracts of mammalian pulmonary surfactant. Automated Edman degradation in a gas-phase sequencer showed the major N-terminus of the human low molecular weight protein to be Phe-Pro-Ile-Pro-Leu-Pro-Try-Cys-Trp-Leu-Cys-Arg-Ala-Leu-. Because of the N-terminal phenylalanine, the surfactant protein was designated SPL(Phe). Antiserum generated against hydrophobic surfactant protein(s) from bovine pulmonary surfactant recognized protein of M/sub r/ 6000-14,000 in immunoblot analysis and was used to screen a lambdagt11 expression library constructed from adult human lung poly(A)/sup +/ RNA. This resulted in identification of a 1.4-kilobase cDNA clone that was shown to encode the N-terminus of the surfactant polypeptide SPL(Phe) (Phe-Pro-Ile-Pro-Leu-Pro-) within an open reading frame for a larger protein. Expression of a fused ..beta..-galactosidase-SPL (Phe) gene in Escherichia coli yielded an immunoreactive M/sub r/ 34,000 fusion peptide. Hybrid-arrested translation with the cDNA and immunoprecipitation of (/sup 35/S)methionine-labeled in vitro translation products of human poly(A)/sup +/ RNA with a surfactant polyclonal antibody resulted in identification of a M/sub r/ 40,000 precursor protein. Blot hybridization analysis of electrophoretically fractionated RNA from human lung detected a 2.0-kilobase RNA that was more abundant in adult lung than in fetal lung. These proteins, and specifically SPL(Phe), may therefore be useful for synthesis of replacement surfactants for treatment of hyaline membrane disease in newborn infants or of other surfactant-deficient states.

  11. Correlation between magnetic and electric field perturbations in the field-aligned current regions deduced from DE 2 observations

    NASA Technical Reports Server (NTRS)

    Ishii, M.; Sugiura, M.; Iyemori, T.; Slavin, J. A.

    1992-01-01

    The satellite-observed high correlations between magnetic and electric field perturbations in the high-latitude field-aligned current regions are investigated by examining the dependence of the relationship between Delta-B and E on spatial scale, using the electric and magnetic field data obtained by DE 2 in the polar regions. The results are compared with the Pedersen conductivity inferred from the international reference ionosphere model and the Alfven wave velocity calculated from the in situ ion density and magnetic field measurements.

  12. Introducing Fourier-domain mobility spectrum analysis (FMSA) to deduce multi-component carrier mobility and density

    NASA Astrophysics Data System (ADS)

    Cui, Boya; Tang, Yang; Grayson, M.

    2015-01-01

    Compounds and heterostructures in optical devices often host multiple carrier species that contribute simultaneously to the total electrical conduction, making it difficult to distinguish the characteristics of each type. Here a Fourier-domain Mobility Spectrum Analysis (FMSA)1 is introduced to sort the conductivity contributions of different carrier species from magnetotransport measurements. Using simulated magnetotransport data from 0 to 15 T of a simple initial trial spectrum, FMSA iteratively adjusts the spectral points in either the mobility domain or its Fourier reciprocal space to fit a mobility range spanning over three orders of magnitude (μ = 670 ~ 1,000,000 cm2/V·s). With its alternating local and global adjustments, FMSA is able to recover the mobility distribution of test data, as verified in convergence plots of the total error as a function of iteration number. This technique resolves the mobility spectra as well or better than competing MSA techniques with a simple and elegant algorithm, while precisely resolving the smoothness and width of mobility peaks without artificial broadening.

  13. Using Arrested Solid-Solid Multiphase Reactions in Geological Materials to Deduce the Rate of Crustal Uplift

    SciTech Connect

    Glassley, W.E.; Meike, A.

    2000-03-13

    The history geological terrains experience can be traced as a series of temperature and pressure changes. Each change drives the system toward a new state of thermodynamic equilibrium. The resultant overprinted rock fabrics, textures and chemical heterogeneities can be difficult to interpret. However, if carefully chosen, features from the scale of kilometers to nanometers can be used to reconstruct the history of mountain systems. Uplift of the Sri Lankan Central Highlands was rapid enough to preserve well-developed symplectite textures, some of which represent arrested solid-state diffusion-controlled reactions of garnet + O{sub 2} to form orthopyroxene + plagioclase + magnetite, as the rocks were exhumed from over 30 km in the earth's crust. Our objective has been to determine the reaction mechanisms responsible for symplectite development, and to establish the time interval over which these reactions occurred, to constrain the rate of mountain uplift. Considering that the most rapid mechanism is solid state grain-boundary diffusion of oxygen, the reaction time can be constrained by bounding the rate of oxygen supply to the reaction site. The solid state grain boundary diffusion rate of oxygen has been inferred to be ca. 10{sup -14}m{sup 2}-sec (Farver and Yund, 1991), but is sensitive to inferred grain boundary width. The range of rates thus determined allows the distinction between rapid uplift similar to that of the Himalayan Mountains, and the slow and progressive erosion of a less dramatic terrain. Further constraints on diffusion control and energetic relationships are determined from crystallographic relationships between the reactant and product phases, and submicron scale microstructure.

  14. Detailed spatial distribution of microearthquakes beneath the Marmara Sea, Turkey, deduced from long-term ocean bottom observation

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yojiro; Takahashi, Narumi; Pinar, Ali; Kalafat, Doǧan; Citak, Seckin; Comoglu, Mustafa; Polat, Remzi; Çok, Özkan; Ogutcu, Zafer; Suvariklı, Murat; Tunc, Suleyman; Gürbüz, Cemil; Turhan, Fatih; Ozel, Nurcan; Kaneda, Yoshiyuki

    2016-04-01

    The North Anatolian Fault (NAF) crosses the Marmara Sea in E-W direction, accommodating about 25 mm/yr of right-lateral motion between Anatolia and the Eurasian plate. There are many large earthquakes along the 1500 km long NAF repeatedly occurred and interacted each other. The recent large northern Aegean earthquake with Mw=6.9 filled one of the last two seismic gaps on NAF that experienced extraordinary seismic moment release cycle during the last century and confirmed a remained blank zone in the Marmara Sea. However, this segment keeps its mystery due to its underwater location. Earthquake hazard and disaster mitigation studies in Marmara region are sensitive to detailed information on fault geometry and its stick-slip behavior beneath the western Marmara Sea. We have started ocean bottom seismographic observations to obtain the detailed information about fault geometry and its stick-slip behavior beneath the western Marmara Sea, as a part of the SATREPS collaborative project between Japan and Turkey namely "Earthquake and Tsunami Disaster Mitigation in the Marmara Region and Disaster Education in Turkey". The target area spans from western Marmara Sea to offshore Istanbul along the NAF. In the beginning of the project, we deployed ten Ocean Bottom Seismographs (OBSs) between the Tekirdag Basin and the Central Basin (CB) in September 2014. Then, we added five Japanese OBSs and deployed them in the western end of the Marmara Sea and in the eastern CB to extend the observed area in March 2015. We retrieved all 15 OBSs in July 2015 and deployed them again in the same locations after data retrieve and battery maintenance. From continuous OBS records, we could detect more than 700 events near the seafloor trace of NAF during 10 months observation period whereas land-seismic network could detect less than 200 events. We estimated the micro-earthquake location using manual-picking arrival times incorporating station corrections. The tentative results show heterogeneous seismicity. The Western High (WH) and CB have relative high seismicity and the seismogenic zone was found to be thicker than the previous estimations done by other researchers. Our result clearly shows that the maximum depth of seismogenic zone is about 24 km beneath the WH and the western half of CB. This depth suddenly decrease to about 15 km in the eastern half of CB, suggesting that there is some structural or frictional boundary on NAF around 28°E. Our results also suggested that the dip angle of NAF is almost vertical beneath WH, whereas it is about 10 degrees southward dipping beneath the eastern CB. We will perform local seismic tomography to obtain more precious hypocenter location and fault geometry.

  15. Chromospheric evaporation flows and density changes deduced from Hinode/EIS during an M1.6 flare

    NASA Astrophysics Data System (ADS)

    Gömöry, P.; Veronig, A. M.; Su, Y.; Temmer, M.; Thalmann, J. K.

    2016-04-01

    Aims: We study the response of the solar atmosphere during a GOES M1.6 flare using spectroscopic and imaging observations. In particular, we examine the evolution of the mass flows and electron density together with the energy input derived from hard X-ray (HXR) in the context of chromospheric evaporation. Methods: We analyzed high-cadence sit-and-stare observations acquired with the Hinode/EIS spectrometer in the Fe xiii 202.044 Å (log T = 6.2) and Fe xvi 262.980 Å (log T = 6.4) spectral lines to derive temporal variations of the line intensity, Doppler shifts, and electron density during the flare. We combined these data with HXR measurements acquired with RHESSI to derive the energy input to the lower atmosphere by flare-accelerated electrons. Results: During the flare impulsive phase, we observe no significant flows in the cooler Fe xiii line but strong upflows, up to 80-150 km s-1, in the hotter Fe xvi line. The largest Doppler shifts observed in the Fe xvi line were co-temporal with the sharp intensity peak. The electron density obtained from a Fe xiii line pair ratio exhibited fast increase (within two minutes) from the pre-flare level of 5.01 × 109 cm-3 to 3.16 × 1010 cm-3 during the flare peak. The nonthermal energy flux density deposited from the coronal acceleration site to the lower atmospheric layers during the flare peak was found to be 1.34 × 1010 erg s-1 cm-2 for a low-energy cut-off that was estimated to be 16 keV. During the decline flare phase, we found a secondary intensity and density peak of lower amplitude that was preceded by upflows of ~15 km s-1 that were detected in both lines. The flare was also accompanied by a filament eruption that was partly captured by the EIS observations. We derived Doppler velocities of 250-300 km s-1 for the upflowing filament material. Conclusions: The spectroscopic results for the flare peak are consistent with the scenario of explosive chromospheric evaporation, although a comparatively low value of the nonthermal energy flux density was determined for this phase of the flare. This outcome is discussed in the context of recent hydrodynamic simulations. It provides observational evidence that the response of the atmospheric plasma strongly depends on the properties of the electron beams responsible for the heating, in particular the steepness of the energy distribution. The secondary peak of line intensity and electron density detected during the decline phase is interpreted as a signature of flare loops being filled by expanding hot material that is due to chromospheric evaporation. A movie is available at http://www.aanda.org

  16. Distribution of star formation rates during the rapid assembly of NGC 1399 as deduced from its globular cluster system

    NASA Astrophysics Data System (ADS)

    Schulz, C.; Hilker, M.; Kroupa, P.; Pflamm-Altenburg, J.

    2016-10-01

    Ultra-compact dwarf galaxies (UCDs) share many properties with globular clusters (GCs) and are found in similar environments. Here, a large sample of UCDs and GCs around NGC 1399, the central giant elliptical of the Fornax galaxy cluster, is used to infer their formation history and also to shed light on the formation of NGC 1399 itself. We assumed that all GCs and UCDs in our sample are the result of star cluster (SC) formation processes and used them as tracers of past star formation activities. After correcting our GC/UCD sample for mass loss, we interpreted their overall mass function to be a superposition of SC populations that formed coevally during different formation epochs. The SC masses of each population were distributed according to the embedded cluster mass function (ECMF), a pure power law with the slope - β. Each ECMF was characterized by a stellar upper mass limit, Mmax, which depended on the star formation rate (SFR). We decomposed the observed GC/UCD mass function into individual SC populations and converted Mmax of each SC population to an SFR. The overall distribution of SFRs reveals under which conditions the GC/UCD sample around NGC 1399 formed. Considering the constraints set by the age of the GCs/UCDs and the present stellar mass of NGC 1399, we found that the formation of the GCs/UCDs can be well explained within our framework with values for β below 2.3. This finding agrees very well with the observation of young SCs where β ≈ 2.0 is usually found. Even though we took into account that some of the most massive objects might not be genuine SCs and applied different corrections for the mass loss, we found that these considerations do not influence much the outcome. We derived the peak SFRs to be between approximately 300 and 3000 M⊙ yr-1, which matches the SFRs observed in massive high-redshift sub-millimeter galaxies and an SFR estimate inferred from NGC 1399 based on the so-called downsizing picture, meaning that more massive galaxies must have formed over shorter periods of time. Our findings give rise to the interpretation that NGC 1399 and its GC/UCD system formed in a relatively short, intense starburst early on.

  17. Membrane fluidity profiles as deduced by saturation-recovery EPR measurements of spin-lattice relaxation times of spin labels

    PubMed Central

    Mainali, Laxman; Feix, Jimmy B.; Hyde, James S.; Subczynski, Witold K.

    2011-01-01

    There are no easily obtainable EPR spectral parameters for lipid spin labels that describe profiles of membrane fluidity. The order parameter, which is most often used as a measure of membrane fluidity, describes the amplitude of wobbling motion of alkyl chains relative to the membrane normal and does not contain explicitly time or velocity. Thus, this parameter can be considered as nondynamic. The spin-lattice relaxation rate (T−11) obtained from saturation-recovery EPR measurements of lipid spin labels in deoxygenated samples depends primarily on the rotational correlation time of the nitroxide moiety within the lipid bilayer. Thus, T−11 can be used as a convenient quantitative measure of membrane fluidity that reflects local membrane dynamics. T−11 profiles obtained for 1-palmitoyl-2-(n-doxylstearoyl)phosphatidylcholine (n-PC) spin labels in dimyristoylphosphatidylcholine (DMPC) membranes with and without 50 mol% cholesterol are presented in parallel with profiles of the rotational diffusion coefficient, R⊥, obtained from simulation of EPR spectra using Freed's model. These profiles are compared with profiles of the order parameter obtained directly from EPR spectra and with profiles of the order parameter obtained from simulation of EPR spectra. It is shown that T−11 and R⊥ profiles reveal changes in membrane fluidity that depend on the motional properties of the lipid alkyl chain. We find that cholesterol has a rigidifying effect only to the depth occupied by the rigid steroid ring structure and a fluidizing effect at deeper locations. These effects cannot be differentiated by profiles of the order parameter. All profiles in this study were obtained at X-band (9.5 GHz). PMID:21868272

  18. Formation age and geomorphologic history of the Lonar impact crater deduced from in- situ cosmogenic 10Be and 26Al

    NASA Astrophysics Data System (ADS)

    Nakamura, A.; Yokoyama, Y.; Sekine, Y.; Goto, K.; Komatsu, G.; Kumar, P.; Matsuzaki, H.; Matsui, T.

    2013-12-01

    Impact cratering is a dominant surface modification process on planetary surfaces. In the inner solar system, the large majority of impacts occur on bodies covered by primitive igneous rocks. However, most of the impacts remaining on Earth surface are on different rock types than that of the inner planet and hence geologic knowledge derived from Earth's surface cannot be translated readily. The Lonar crater is a 1.88-km-diameter crater located on the Deccan basaltic traps in India (ca. 65 Ma), and is one of a few craters on Earth bombarded directly on basaltic lava flows. Thus, the Lonar crater provides a rare opportunity to study impact structures on the basaltic surfaces of other terrestrial planets and the Moon. Since the ages of terrestrial impact structures is a key to understand geomorphological processes after the impact, various dating methods have been applied to the Lonar Crater such as fission track (Storzer and Koeberl, 2004), radiocarbon (Maloof, 2010), thermoluminescence (Sengupta et al., 1997), and 40Ar/39Ar (Jourdan et al., 2011). Yet, a large discrepancy between these methods ranging from ca. 1.79 to 570 ka has been resulted. Here we report surface exposure ages based on in-situ cosmogenic 10Be and 26Al in order to obtain a precise age of the Lonar crater formation as well as to study the geomorphologic evolution. The samples are collected from the topographic highs on the rim of the crater and from the ejecta blanket. Exposure ages together with newly obtained radiocarbon age of pre-impact soil indicate much younger ages than that of obtained from 40Ar/39Ar method. This suggests the potential bias because of inherited 40Ar in impact glass. Systematically young exposure age from the rim samples compared to the samples from the ejecta blanket indicate that the rim of the Lonar crater is being actively eroded. Spatial distributions of geomorphic ages observed from the Lonar creator is not the same as the pattern reported from the well-studied Barringer crater in Arizona (Nishiizumi et al, 1991, Phillips et al., 1991), highlighting the different geomorphologic processes of the two craters due to the different climatic and lithologic settings between the two.

  19. Application of geochemical techniques to deduce the reservoir performance of the Palinpinon Geothermal Field, Philippines - an update

    SciTech Connect

    Ramos-Candelaria, M.N.; Garcia, S.E.; Hermoso, D.Z.

    1997-12-31

    Regular monitoring of various geochemical parameters in the water and vapor phases of the production wells at the Palinpinon I and II sectors of the Southern Negros Geothermal Field have been useful in the identification of the dominant reservoir processes occurring related to the present exploitation strategy. Observed geochemical and physical changes in the output of production wells have dictated production and injection strategies adopted to maximize production to meet the steam requirements of the power plant. Correlation of both physical and chemical data have identified the following reservoir processes: (1) Injection breakthrough via the Ticala Fault of the highly mineralized (Cl {approximately}8,000-10,500 mg/kg), isotopically enriched ({delta}{sup 18}O = -3.00{per_thousand}, {delta}{sup 2} H = -39{per_thousand}), and gas depleted brine for wells in the SW and central Puhagan. Injection breakthrough is also occurring in Palinpinon II and has resulted in temperature drops of 5-10{degrees}C.2. Pressure drawdown enhanced boiling in the liquid reservoir with steam separation of 220-240{degrees}C, feeding wells tapping the natural steam zone. However, enhanced drawdown has induced the entry of shallow acid steam condensate fluids in some wells (e.g. OK-7, PN-29D, PN-18D), which if not arrested could reduce production.

  20. Nanocrystalline tin oxide: Possible origin of its weak ferromagnetism deduced from nuclear magnetic resonance and X-ray photoelectron spectroscopies

    NASA Astrophysics Data System (ADS)

    Zhang, Feng; Lian, Yadong; Gu, Min; Yu, Ji; Tang, Tong B.; Sun, Jian; Zhang, Weiyi

    2016-09-01

    Nanocrystalline tin oxide was fabricated, with molar ratio O/Sn determined as 1.40, 1.55, 1.79, 1.92 and 1.96 from X-ray photoelectron spectroscopy. They displayed weak ferromagnetism, the sample with O/Sn = 1.55 showing the maximum saturation magnetization reaching almost 8 ×10-3 emu /g at room temperature. 119Sn nuclear magnetic resonance allowed the deduction, based on four resolved resonance peaks, that their Sn ions had four possible coordination numbers, namely 3, 4, 5 and 6. The relative fraction of 4-coordinated cations was the one found to bear positive linear correlation with saturation magnetization of the sample. It is surmised that magnetism in tin oxide results mainly from 4-coordination Sn ions, of valance about +3, as estimated from the binding energies of their 3d photoelectron emission levels.

  1. Level and length of cyclic solar activity during the Maunder minimum as deduced from the active-day statistics

    NASA Astrophysics Data System (ADS)

    Vaquero, J. M.; Kovaltsov, G. A.; Usoskin, I. G.; Carrasco, V. M. S.; Gallego, M. C.

    2015-05-01

    Aims: The Maunder minimum (MM) of greatly reduced solar activity took place in 1645-1715, but the exact level of sunspot activity is uncertain because it is based, to a large extent, on historical generic statements of the absence of spots on the Sun. Using a conservative approach, we aim to assess the level and length of solar cycle during the MM on the basis of direct historical records by astronomers of that time. Methods: A database of the active and inactive days (days with and without recorded sunspots on the solar disc) is constructed for three models of different levels of conservatism (loose, optimum, and strict models) regarding generic no-spot records. We used the active day fraction to estimate the group sunspot number during the MM. Results: A clear cyclic variability is found throughout the MM with peaks at around 1655-1657, 1675, 1684, 1705, and possibly 1666, with the active-day fraction not exceeding 0.2, 0.3, or 0.4 during the core MM, for the three models. Estimated sunspot numbers are found to be very low in accordance with a grand minimum of solar activity. Conclusions: For the core MM (1650-1700), we have found that (1) A large portion of no-spot records, which correspond to the solar meridian observations, may be unreliable in the conventional database. (2) The active-day fraction remained low (below 0.3-0.4) throughout the MM, indicating the low level of sunspot activity. (3) The solar cycle appears clearly during the core MM. (4) The length of the solar cycle during the core MM appears for 9 ± 1 years, but this is uncertain. (5) The magnitude of the sunspot cycle during MM is assessed to be below 5-10 in sunspot numbers. A hypothesis of the high solar cycles during the MM is not confirmed.

  2. Secular and earthquake-related vertical crustal movements in Japan as deduced from tidal records (1951 1981)

    NASA Astrophysics Data System (ADS)

    Kato, Teruyuki

    1983-09-01

    Monthly tidal records for the last 31 years from about 100 tidal stations are used to delineate vertical crustal movements in Japan. A new computer-aided processing system was created for this purpose. Its principle is differential use of tidal records in a region, so that the oceanographic disturbances of common causes may be eliminated from the sea-level data. This method enables us to observe nearly absolute vertical land movement at tidal stations with a precision of a few centimeters. The Japanese Islands are divided into nine regions, taking oceanographic conditions into account. General discussion on recent vertical movements has yielded several notable features and trends as follows: (1) Rapid and stationary subsidence in the northeastern part of Japan, presumably of tectonic origin. (2) A complex pattern of uplift and subsidence in the southwestern part of Japan, which seems to reflect subduction of the Philippine Sea plate against the Honshu block. (3) Relatively stable land on the Japan Sea side of Honshu. Movements related to the earthquakes during the period 1951-1981 are also discussed, although few of the cases show clear-cut premonitory movements. If abnormal movements in a coastal area, appeared with an amplitude exceeding 2 or 3 cm, we could detect them by the present system.

  3. The radiated energy budget of chromospheric plasma in a major solar flare deduced from multi-wavelength observations

    SciTech Connect

    Milligan, Ryan O.; Mathioudakis, Mihalis; Keenan, Francis P.; Kerr, Graham S.; Hudson, Hugh S.; Fletcher, Lyndsay; Dennis, Brian R.; Allred, Joel C.; Chamberlin, Phillip C.; Ireland, Jack

    2014-10-01

    This paper presents measurements of the energy radiated by the lower solar atmosphere, at optical, UV, and EUV wavelengths, during an X-class solar flare (SOL2011-02-15T01:56) in response to an injection of energy assumed to be in the form of nonthermal electrons. Hard X-ray observations from RHESSI were used to track the evolution of the parameters of the nonthermal electron distribution to reveal the total power contained in flare accelerated electrons. By integrating over the duration of the impulsive phase, the total energy contained in the nonthermal electrons was found to be >2 × 10{sup 31} erg. The response of the lower solar atmosphere was measured in the free-bound EUV continua of H I (Lyman), He I, and He II, plus the emission lines of He II at 304 Å and H I (Lyα) at 1216 Å by SDO/EVE, the UV continua at 1600 Å and 1700 Å by SDO/AIA, and the white light continuum at 4504 Å, 5550 Å, and 6684 Å, along with the Ca II H line at 3968 Å using Hinode/SOT. The summed energy detected by these instruments amounted to ∼3 × 10{sup 30} erg; about 15% of the total nonthermal energy. The Lyα line was found to dominate the measured radiative losses. Parameters of both the driving electron distribution and the resulting chromospheric response are presented in detail to encourage the numerical modeling of flare heating for this event, to determine the depth of the solar atmosphere at which these line and continuum processes originate, and the mechanism(s) responsible for their generation.

  4. Effects of stress rate and calculation method on subcritical crack growth parameters deduced from constant stress-rate flexural testing

    PubMed Central

    Griggs, Jason A.; Alaqeel, Samer M.; Zhang, Yunlong; Miller, Amp W.; Cai, Zhuo

    2011-01-01

    Objectives To more efficiently determine the subcritical crack growth (SCG) parameters of dental ceramics, the effects of stressing rate and choice of statistical regression model on estimates of SCG parameters were assessed. Methods Two dental ceramic materials, a veneering material having a single critical flaw population (S) and a framework material having partially concurrent flaw populations (PC), were analyzed using constant stress-rate testing, or “dynamic fatigue”, with a variety of testing protocols. For each material, 150 rectangular beam specimens were prepared and tested in four-point flexure according to ISO6872 and ASTM1368. A full-factorial study was conducted on the following factors: material, stress rate assumed vs. calculated, number of stress rates, and statistical regression method. Results The proportion of specimens for which the statistical models over-estimated reliability was not significantly different based on regression method for Material S (P = 0.96, power = 94%) and was significantly different based on regression method for Material PC (P < 0.001). The standard method resulted in SCG parameters, n and ln B, of 35.9 and -11.1 MPa2s for Material S and 12.4 and 9.61 MPa2s for Material PC. Significance The method of calculation that uses only the median strength value at each stress rate provided the most robust SCG parameter estimates. Using only two stress rates resulted in fatigue parameters comparable to those estimated using four stress rates having the same range. The stress rate of each specimen can be assumed to be the target stress rate with negligible difference in SCG parameter estimates. PMID:21167586

  5. Mid-lithospheric Discontinuity Beneath the Malawi Rift, Deduced from Gravity Studies and its Relation to the Rifting Process.

    NASA Astrophysics Data System (ADS)

    Njinju, E. A.; Atekwana, E. A.; Mickus, K. L.; Abdelsalam, M. G.; Atekwana, E. A.; Laó-Dávila, D. A.

    2015-12-01

    The World Gravity Map satellite gravity data were used to investigate the lithospheric structure beneath the Cenozoic-age Malawi Rift which forms the southern extension of the Western Branch of the East African Rift System. An analysis of the data using two-dimensional (2D) power spectrum methods indicates the two distinctive discontinuities at depths of 31‒44 km and 64‒124 km as defined by the two steepest slopes of the power spectrum curves. The shallower discontinuity corresponds to the crust-mantle boundary (Moho) and compares well with Moho depth determined from passive seismic studies. To understand the source of the deeper discontinuity, we applied the 2D power spectrum analysis to other rift segments of the Western Branch as well as regions with stable continental lithospheres where the lithospheric structure is well constrained through passive seismic studies. We found that the deeper discontinuity corresponds to a mid-lithospheric discontinuity (MLD), which is known to exist globally at depths between 60‒150 km and as determined by passive seismic studies. Our results show that beneath the Malawi Rift, there is no pattern of N-S elongated crustal thinning following the surface expression of the Malawi Rift. With the exception of a north-central region of crustal thinning (< 35 km), most of the southern part of the rift is underlain by thick crust (~40‒44 km). Different from the Moho, the MLD is shallower beneath the axis of the Malawi Rift forming a N-S trending zone with depths of 64‒80 km, showing a broad and gentle topography. We interpret the MLD as representing a sharp density contrast resulting from metasomatized lithosphere due to lateral migration along mobile belts of hot mantle melt or fluids from a distant plume and not from an ascending asthenosphere. These fluids weaken the lithosphere enhancing rift nucleation. The availability of satellite gravity worldwide makes gravity a promising technique for determining the MLD globally.

  6. Marine reservoir effect deduced from 14C dates on marine shells and terrestrial remains at archeological sites in Japan

    NASA Astrophysics Data System (ADS)

    Nakamura, Toshio; Nishida, Iwao; Takada, Hideki; Okuno, Mitsuru; Minami, Masayo; Oda, Hirotaka

    2007-06-01

    Paired marine and terrestrial samples were collected at archeological shell mounds in Kagoshima, Saga and Aichi prefectures and selected from sediment samples bored at the Mawaki archeological site in Ishikawa prefecture, to evaluate the local marine reservoir effect in Japan. The local reservoir corrections, ΔR, were evaluated to be 8 ± 110 and -178 ± 113 14C years for Miyasaka shell mound, -125 ± 50 to -45 ± 49 and -86 ± 48 to -21 ± 50 14C years for Higashimyo shell mound, -46 ± 52, 40 ± 44, -136 ± 44 and 100 ± 44 14C years for Yoshigo shell mound, -255 ± 38 and -146 ± 46 14C years for Kuzubasama shell mound, -71 ± 33, -30 ± 85 and -78 ± 74 14C years on average for C4, C5 and C6 cores, respectively, from the Mawaki site. The existing data along with the present results suggest that the ΔR values obtained for central to southern part of Japan are consistent with zero or a bit negative, but are different from the ΔR values of 200 to 500 14C years for the northern parts of the Japanese archipelago.

  7. Limits to the burster repetition rate as deduced from the 2nd catalog of the interplanetary network

    NASA Technical Reports Server (NTRS)

    Atteia, J. L.; Barat, C.; Hurley, K.; Niel, M.; Vedrenne, G.; Evans, W. D.; Fenimore, E. E.; Klebesadel, R. W.; Laros, J. G.; Cline, T. L.

    1985-01-01

    The burster repetition rate is an important parameter in many gamma ray burst models. The localizations of the interplanetary network, which have a relatively small combined surface area, may be used to estimate the average repetition rate. The method consists of (1) estimating the number of random overlaps between error boxes expected in the catalog and comparing this number to that actually observed; (2) modeling the response of the detectors in the network, so that the probability of detecting a burst can be estimated; and (3) simulating the arrival of bursts at the network assuming that burster repetition is governed by a Poisson process. The application of this method for many different burster luminosity functions shows that (1) the lower limit to the burster repetition rate depends strongly upon the assumed luminosity function; (2) the best lower limit to the repetition period obtainable from the data of the network is about 100 months; and (3) that a luminosity function for all bursters similar to that of the 1979 Mar 5 burster is inconsistent with the data.

  8. Two-phase Neogene extension of the northwestern Basin and Range deduced from thermochronology of a single sample

    NASA Astrophysics Data System (ADS)

    Colgan, J. P.; Shuster, D. L.; Reiners, P. W.

    2007-12-01

    We use a combination of apatite 4He/3He, (U-Th)/He, and fission-track thermochronology to date slip on the Surprise Valley Fault in northeastern California by analyzing a single granitic boulder from a conglomerate lens near the base of the adjacent Warner Range. Apatite from this sample yielded a fission-track age of 11.6 ± 1.4 Ma and a (U-Th)/He age of 3.12 ± 0.2 Ma. Regional geologic relationships indicate that this sample was buried to a depth of about 3.3 km prior to exhumation during slip on the Surprise Valley Fault. Apatite fission-track data indicate that the sample was fully reset (>120°C) prior to exhumation, which began sometime after 14 Ma. A single aliquot of nine apatite grains was step-heated for 4He/3He analysis; modeling of the resulting 4He distribution indicates cooling from >80°C to ~20°C between 3 and 1 Ma. Internally consistent time-temperature (t-T) solutions to the combined 4He/3He, (U-Th)/He, and fission-track data require two periods of cooling, consistent with non-continuous slip on the Surprise Valley Fault. Early cooling and fault slip took place between 14 and 8 Ma, and was followed by a more recent pulse of cooling at about 3 Ma. This timing is consistent with both local geologic relationships and with the regional timing of faulting along the western margin of the Basin and Range. These data demonstrate the resolving power of combined fission-track, (U-Th)/He, and 4He/3He thermochronometric data to extract high-resolution and ultra low temperature t-T information from a single sample close to the earth's surface.

  9. Functional groups of sialic acids involved in binding to siglecs (sialoadhesins) deduced from interactions with synthetic analogues.

    PubMed

    Kelm, S; Brossmer, R; Isecke, R; Gross, H J; Strenge, K; Schauer, R

    1998-08-01

    The siglecs, formerly called sialoadhesins, are a family of I-type lectins binding to sialic acids on the cell surface. Five members of this family have been identified: sialoadhesin, myelin-associated glycoprotein (MAG), Schwann cell myelin protein (SMP), CD22 and CD33. We have investigated the relevance of substituents at position C-9 and in the N-acetyl group of N-acetylneuraminic acid, using a series of synthetic sialic-acid analogues either on resialylated human erythrocytes or as free alpha-glycosides in hapten inhibition. All five siglecs require the hydroxy group at C-9 for binding, suggesting hydrogen bonding of this substituent with the binding site. Remarkable differences were found among the proteins in their specificity for modifications of the N-acetyl group. Whereas sialoadhesin, MAG and SMP do not tolerate a hydroxy group as in N-glycolylneuraminic acid, they bind to halogenated acetyl residues. In the case of MAG, N-fluoroacetylneuraminic acid is bound about 17-fold better than N-acetylneuraminic acid. In contrast, human and murine CD22 both show good affinity for N-glycolylneuraminic acid, but only human CD22 bound the halogenated compounds. In conclusion, our data indicate that interactions of the hydroxy group at position 9 and the N-acyl substituent contribute significantly to the binding strength. PMID:9738906

  10. Evolutionary history of larval skeletal morphology in sea urchin Echinometridae (Echinoidea: Echinodermata) as deduced from mitochondrial DNA molecular phylogeny.

    PubMed

    Kinjo, Sonoko; Shirayama, Yoshihisa; Wada, Hiroshi

    2008-01-01

    The larval skeletons of sea urchins show considerable morphological diversity, even between closely related species, although the evolutionary history and functional significance of this diversity are poorly understood. To infer the evolutionary history of the skeletal morphology, we focused on echinometrid species for which the morphological variation in larval skeletons had been investigated qualitatively and quantitatively. We reconstructed the phylogenetic relationships among 14 echinometrid species based on mitochondrial ND1 and ND2 genes and mapped the morphological characters onto the resultant trees. The monophyly of each genus in the Echinometridae was well supported by our results, as was the close affinity between Colobocentrotus, Heterocentrotus, and Echinometra. The mapping of the morphological characters of the larval skeletons indicated that the length, direction, and density of spines on the postoral rods was well conserved in each group of Echinometridae and that the abundance of spines and the size and shape of the body skeleton changed relatively frequently and hence were less conserved. In Echinometrid species, morphological variation in relatively unconserved features tends to be associated with latitudinal distributions, rather than phylogenetic relationships, indicating that the morphological diversity of larval skeletons could have been caused by adaptation to the habitat environment. Some morphological differences, however, seem to be nonfunctional and generated by the constraints on larval skeletogenesis. Thus, echinometrid species can be a good model with which to study the evolutionary history from both ecological and developmental standpoints. PMID:18803780

  11. Culinary Herbs and Spices: Their Bioactive Properties, the Contribution of Polyphenols and the Challenges in Deducing Their True Health Benefits

    PubMed Central

    Opara, Elizabeth I.; Chohan, Magali

    2014-01-01

    Herbs and spices have been used for both culinary and medicinal purposes for centuries. Over the last decade, research into their role as contributors of dietary polyphenols, known to possess a number of properties associated with reducing the risk of developing chronic non-communicable diseases, has increased. However, bearing in mind how these foods are consumed, normally in small quantities and in combination with other foods, it is unclear what their true benefit is from a health perspective. The aim of this review is to use the literature to discuss how preparative and digestive processes, bioavailability and interactions between foods may influence the bioactive properties of these foods, and whether or not polyphenols are responsible for these properties. Furthermore, this review aims to highlight the challenges that need to be addressed so as to determine the true benefits of these foods and the mechanisms of action that underpin their purported efficacy. PMID:25340982

  12. High latitude field aligned light ion flows in the topside ionosphere deduced from ion composition and plasma temperatures

    NASA Technical Reports Server (NTRS)

    Grebowsky, J. M.; Hoegy, W. R.; Chen, T. C.

    1993-01-01

    Using a comprehensive ionospheric data set comprised of all available ion composition and plasma temperature measurements from satellites, the vertical distributions of ion composition and plasma temperatures are defined from middle latitudes up into the polar cap for summer conditions for altitudes below about 1200 km. These data are sufficient to allow a numerical estimation of the latitudinal variation of the light ion outflows from within the plasmasphere to the polar wind regions. The altitude at which significant light ion outflow begins is found to be lower during solar minimum conditions than during solar maximum. The H(+) outward speeds are of the order of 1 km/s near 1100 km during solar maximum but attain several km/s speeds for solar minimum. He(+) shows a similar altitude development of flow but attains polar cap speeds much less than 1 km/s at altitudes below 1100 km, particularly under solar maximum conditions. Outward flows are also found in the topside F-region for noontime magnetic flux tubes within the plasmasphere.

  13. Global characteristics of the cold plasma in the equatorial plasmapause region as deduced from the geos 1 mutual impedance probe

    SciTech Connect

    Decreu, P.M.E.; Beghin, C.; Parrot, M.

    1982-02-01

    Thermal plasma parameters derived by the muntal impedance experiment on GEOS are described. The experiment is well suited to the measurement of the electron density and temperature of the outer plasmasphere (when kT/sub e//N/sub e/<1.6 eV/cm/sup 3/). This investigation of the whole set of data supplied by GEOS 1 (4

  14. Following the Viterbi Path to Deduce Flagellar Actin-Interacting Proteins of Leishmania spp.: Report on Cofilins and Twinfilins

    NASA Astrophysics Data System (ADS)

    Pacheco, Ana Carolina L.; Araújo, Fabiana F.; Kamimura, Michel T.; Medeiros, Sarah R.; Viana, Daniel A.; Oliveira, Fátima de Cássia E.; Filho, Raimundo Araújo; Costa, Marcília P.; Oliveira, Diana M.

    2007-11-01

    For performing vital cellular processes, such as motility, eukaryotic cells rely on the actin cytoskeleton, whose structure and dynamics are tightly controlled by a large number of actin-interacting (AIP) or actin-related/regulating (ARP) proteins. Trypanosomatid protozoa, such as Leishmania, rely on their flagellum for motility and sensory reception, which are believed to allow parasite migration, adhesion, invasion and even persistence on mammalian host tissues to cause disease. Actin can determine cell stiffness and transmit force during mechanotransduction, cytokinesis, cell motility and other cellular shape changes, while the identification and analyses of AIPs can help to improve understanding of their mechanical properties on physiological architectures, such as the present case regarding Leishmania flagellar apparatus. This work conveniently apply bioinformatics tools in some refined pattern recognition techniques (such as hidden Markov models (HMMs) through the Viterbi algorithm/path) in order to improve the recognition of actin-binding/interacting activity through identification of AIPs in genomes, transcriptomes and proteomes of Leishmania species. We here report cofilin and twinfilin as putative components of the flagellar apparatus, a direct bioinformatics contribution in the secondary annotation of Leishmania and trypanosomatid genomes.

  15. Deduced products of C4-dicarboxylate transport regulatory genes of Rhizobium leguminosarum are homologous to nitrogen regulatory gene products.

    PubMed Central

    Ronson, C W; Astwood, P M; Nixon, B T; Ausubel, F M

    1987-01-01

    We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the dctB gene product (DctB) suggested that its N-terminal region may be located in the periplasm and its C-terminal region in the cytoplasm. The C-terminal region of DctB was strongly conserved with similar regions of the products of several regulatory genes that may act as environmental sensors, including ntrB, envZ, virA, phoR, cpxA, and phoM. The N-terminal domains of the products of several regulatory genes thought to be transcriptional activators, including ntrC, ompR, virG, phoB and sfrA. In addition, the central and C-terminal regions of DctD were strongly conserved with the products of ntrC and nifA, transcriptional activators that require the alternate sigma factor rpoN (ntrA) as co-activator. The central region of DctD also contained a potential ATP-binding domain. These results are consistent with recent results that show that rpoN product is required for dctA activation, and suggest that DctB plus DctD-mediated transcriptional activation of dctA may be mechanistically similar to NtrB plus NtrC-mediated activation of glnA in E. coli. PMID:3671068

  16. The Spatial and Temporal Distribution of Lunar Mare Basalts As Deduced From Analysis of Data for Lunar Meteorites

    NASA Technical Reports Server (NTRS)

    Nyquist, Laurence; Basilevsky, A.; Neukum, G.

    2009-01-01

    In this work we analyze chronological data for lunar meteorites with emphasis on the spatial and temporal distribution of lunar mare basalts. The data are mostly from the Lunar Meteorite Compendium (http://www-curator.jsc.nasa.gov/antmet/lmc/contents.cfm cited thereafter as Compendium) compiled by Kevin Righter and from the associated literature.

  17. Concept model of the formation process of humic acid-kaolin complexes deduced by trichloroethylene sorption experiments and various characterizations.

    PubMed

    Zhu, Xiaojing; He, Jiangtao; Su, Sihui; Zhang, Xiaoliang; Wang, Fei

    2016-05-01

    To explore the interactions between soil organic matter and minerals, humic acid (HA, as organic matter), kaolin (as a mineral component) and Ca(2+) (as metal ions) were used to prepare HA-kaolin and Ca-HA-kaolin complexes. These complexes were used in trichloroethylene (TCE) sorption experiments and various characterizations. Interactions between HA and kaolin during the formation of their complexes were confirmed by the obvious differences between the Qe (experimental sorbed TCE) and Qe_p (predicted sorbed TCE) values of all detected samples. The partition coefficient kd obtained for the different samples indicated that both the organic content (fom) and Ca(2+) could significantly impact the interactions. Based on experimental results and various characterizations, a concept model was developed. In the absence of Ca(2+), HA molecules first patched onto charged sites of kaolin surfaces, filling the pores. Subsequently, as the HA content increased and the first HA layer reached saturation, an outer layer of HA began to form, compressing the inner HA layer. As HA loading continued, the second layer reached saturation, such that an outer-third layer began to form, compressing the inner layers. In the presence of Ca(2+), which not only can promote kaolin self-aggregation but can also boost HA attachment to kaolin, HA molecules were first surrounded by kaolin. Subsequently, first and second layers formed (with inner layer compression) via the same process as described above in the absence of Ca(2+), except that the second layer continued to load rather than reach saturation, within the investigated conditions, because of enhanced HA aggregation caused by Ca(2+). PMID:26933902

  18. Wintertime haze deterioration in Beijing by industrial pollution deduced from trace metal fingerprints and enhanced health risk by heavy metals.

    PubMed

    Lin, Yu-Chi; Hsu, Shih-Chieh; Chou, Charles C-K; Zhang, Renjian; Wu, Yunfei; Kao, Shuh-Ji; Luo, Li; Huang, Chao-Hao; Lin, Shuen-Hsin; Huang, Yi-Tang

    2016-01-01

    Airborne particulate matter (PM) was collected in Beijing between 24 February and 12 March 2014 to investigate chemical characteristics and potential industrial sources of aerosols along with health risk of haze events. Results showed secondary inorganic aerosol was the major contributor to PM2.5 during haze days. Utilizing specific elements, including Fe, La, Tl and As, as fingerprinting tracers, four emission sources, namely iron and steel manufacturing, petroleum refining, cement plant, and coal combustion were explicitly identified; their elevated contributions to PM during haze days were also estimated. The average cancer risk from exposure to inhalable PM toxic metals was 1.53 × 10(-4) on haze days, which is one order of magnitude higher than in other developed cities. These findings suggested heavy industries emit large amounts of not only primary PM but also precursor gas pollutants, leading to secondary aerosol formation and harm to human health during haze days. PMID:26277049

  19. The effect of salinization and freshening events in coastal aquifers on nutrient characteristics as deduced from field data

    NASA Astrophysics Data System (ADS)

    Russak, A.; Yechieli, Y.; Herut, B.; Lazar, B.; Sivan, O.

    2015-10-01

    The effect of seawater intrusion and freshening events in coastal aquifers on nutrient (dissolved inorganic nitrogen species, phosphate and silica) dynamics across the fresh-saline groundwater interface (FSI) were quantified using field data. Seasonal vertical profiles revealed a clear transition between nutrient species across the FSI, which is also an oxycline. In view of the results of our experimental simulations, it is clear that the major process controlling the nutrient dynamics at the FSI, besides the mixing that takes place between the two different water bodies, is the seasonal variation between seawater intrusion (salinization) in summer and flushing of the aquifer (freshening) in winter. Aquifer salinization during the summer shifts the FSI and the anaerobic depth-location upwards and leads to the enrichment of NH4+, PO43- and DSi (dissolved silica) in the saline groundwater. NH4+ and PO43- are enriched due to ion exchange, and DSi is enriched either by ion exchange (as PO43-) or as a result of dissolution of biogenic silica. Denitrification occurs at the base of the FSI, as indicated by the slight NO3- depletion and the enrichment in δ15N of NO3-. Aquifer freshening during the winter shifts the FSI downward and the water becomes suboxic with the influence of the oxic fresh groundwater. This leads to nitrification of the NH4+, enrichment of NO2- and depletion of 15N in the residual NO3- in the FSI. These cyclic processes generate a certain depletion of N and enrichment of P in the saline groundwater. Circulation of the saline groundwater below the FSI back to the sea can serve as a partial counterbalance to the high anthropogenic load of N impacting the coastal groundwater system.

  20. Transition state and ground state properties of the helix–coil transition in peptides deduced from high-pressure studies

    PubMed Central

    Neumaier, Sabine; Büttner, Maren; Bachmann, Annett; Kiefhaber, Thomas

    2013-01-01

    Volume changes associated with protein folding reactions contain valuable information about the folding mechanism and the nature of the transition state. However, meaningful interpretation of such data requires that overall volume changes be deconvoluted into individual contributions from different structural components. Here we focus on one type of structural element, the α-helix, and measure triplet–triplet energy transfer at high pressure to determine volume changes associated with the helix–coil transition. Our results reveal that the volume of a 21-amino-acid alanine-based peptide shrinks upon helix formation. Thus, helices, in contrast with native proteins, become more stable with increasing pressure, explaining the frequently observed helical structures in pressure-unfolded proteins. Both helix folding and unfolding become slower with increasing pressure. The volume changes associated with the addition of a single helical residue to a preexisting helix were obtained by comparing the experimental results with Monte Carlo simulations based on a kinetic linear Ising model. The reaction volume for adding a single residue to a helix is small and negative (−0.23 cm3 per mol = −0.38 Å3 per molecule) implying that intrahelical hydrogen bonds have a smaller volume than peptide-water hydrogen bonds. In contrast, the transition state has a larger volume than either the helical or the coil state, with activation volumes of 2.2 cm3/mol (3.7 Å3 per molecule) for adding and 2.4 cm3/mol (4.0 Å3 per molecule) for removing one residue. Thus, addition or removal of a helical residue proceeds through a transitory high-energy state with a large volume, possibly due to the presence of unsatisfied hydrogen bonds, although steric effects may also contribute. PMID:24324160

  1. Saccharomyces cerevisiae phosphoenolpyruvate carboxykinase: physicochemical characteristics of the nucleotide binding site, as deduced from fluorescent spectroscopy measurements.

    PubMed

    Encinas, M V; Quiñones, V; Cardemil, E

    1990-05-15

    Saccharomyces cerevisiae phosphoenolpyruvate carboxykinase [ATP:oxaloacetate carboxy-lyase (transphosphorylating), EC 4.1.1.49] is inactivated by the fluorescent sulfhydryl reagent N-(iodoacetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine (1,5-IAEDANS). The inactivation reaction follows pseudo-first-order kinetics with respect to active enzyme to less than 10% remaining enzyme activity, with a second-order inactivation rate constant of 2.6 min-1 mM-1 at pH 7.5 and 30 degrees C. A stoichiometry of 1.05 mol of reagent incorporated per mole of enzyme subunit was found for the completely inactivated enzyme. Almost complete protection of the enzyme activity and of dansyl label incorporation are afforded by MnADP or MnATP, thus suggesting that 1,5-IAEDANS interacts with an enzyme sulfhydryl group at the nucleotide binding site. The fluorescence decay of the AEDANS attached to the protein shows a single-exponential behavior with a lifetime of 18 ns. A comparison of the fluorescence band position and the fluorescence decay with those of the adduct AEDANS-acetylcysteine indicates a reduced polarity for the microenvironment of the substrate binding site. The quenching of the AEDANS moiety in the protein can be described in terms of a collisional and a static component. The rate constant for the collisional component is much lower than that obtained for the adduct in a medium of reduced polarity. These last results indicate that the AEDANS moiety is considerably shielded from the solvent when it is covalently attached to PEPCK.

  2. Proof of concept study with an HER-2 mimotope anticancer vaccine deduced from a novel AAV-mimotope library platform

    PubMed Central

    Singer, Josef; Manzano-Szalai, Krisztina; Fazekas, Judit; Thell, Kathrin; Bentley-Lukschal, Anna; Stremnitzer, Caroline; Roth-Walter, Franziska; Weghofer, Margit; Ritter, Mirko; Pino Tossi, Kerstin; Hörer, Markus; Michaelis, Uwe; Jensen-Jarolim, Erika

    2016-01-01

    ABSTRACT Background: Anticancer vaccines could represent a valuable complementary strategy to established therapies, especially in settings of early stage and minimal residual disease. HER-2 is an important target for immunotherapy and addressed by the monoclonal antibody trastuzumab. We have previously generated HER-2 mimotope peptides from phage display libraries. The synthesized peptides were coupled to carriers and applied for epitope-specific induction of trastuzumab-like IgG. For simplification and to avoid methodological limitations of synthesis and coupling chemistry, we herewith present a novel and optimized approach by using adeno-associated viruses (AAV) as effective and high-density mimotope-display system, which can be directly used for vaccination. Methods: An AAV capsid display library was constructed by genetically incorporating random peptides in a plasmid encoding the wild-type AAV2 capsid protein. AAV clones, expressing peptides specifically reactive to trastuzumab, were employed to immunize BALB/c mice. Antibody titers against human HER-2 were determined, and the isotype composition and functional properties of these were tested. Finally, prophylactically immunized mice were challenged with human HER-2 transfected mouse D2F2/E2 cells. Results: HER-2 mimotope AAV-vaccines induced antibodies specific to human HER-2. Two clones were selected for immunization of mice, which were subsequently grafted D2F2/E2 cells. Both mimotope AAV clones delayed the growth of tumors significantly, as compared to controls. Conclusion: In this study, a novel mimotope AAV-based platform was created allowing the isolation of mimotopes, which can be directly used as anticancer vaccines. The example of trastuzumab AAV-mimotopes demonstrates that this vaccine strategy could help to establish active immunotherapy for breast-cancer patients. PMID:27622022

  3. Magma plumbing systems deduced from comparison of multiple dike intrusions in an incipientseafloor spreading segment in Afar, Ethiopia

    NASA Astrophysics Data System (ADS)

    Belachew, M.; Ebinger, C. J.; Cote, D. M.; Keir, D.; Rowland, J. V.; Hammond, J. O.; Ayele, A.

    2010-12-01

    Oceanic crust is accreted through the emplacement of dikes at spreading ridges, but the role of dike intrusion in plate boundary deformation during continental rupture remains poorly understood. Since September 2005 the ~70 km-long Dabbahu-Manda Hararo rift segment in Afar, Ethiopia has experienced 14 large volume dike intrusions, including 3 fissural eruptions and a small volume silicic eruption. We present comparisons of 9 dike intrusions recorded by two temporary seismic networks between 2006 and 2009, set within the context of new 3D crustal velocity models of the region. All of the migrating swarms of earthquakes which are interpreted as caused by the dike intrusions and graben formation above the dike started from an ~5 km-radius and > 6 km-deep zone at the middle of the rift segment. The earthquake swarms migrated either to the south or north along the rift. Small magnitude earthquakes associated with the margins of the propagating dike tips are followed by the largest magnitude, mostly low-frequency earthquakes (< 2 Hz) interpreted as slow-slip and/or graben formation above the dike. The seismic moment distributions show > 80% of energy is released during the propagation phase of the dikes with minimal seismic energy release after the dikes ceased to propagate. Thus, for most of the dikes, faulting and graben formation above the dikes occurs hours after the passage of the crack tip, and while the dike continues to lengthen. The dikes that propagated to the north had faster average velocities (0.4 - 0.6m/s) compared to the ones that propagated to the south (0.15 - 0.3 m/s). The propagation velocities of each of the dikes follow a decaying exponential, suggesting pressure drops in the dike feeder zone limit dike volume/length. The small changes in intervals between dike intrusions, and the lack of a decrease in dike length with time both suggest that the magma chamber was regularly recharged over the 4-year period since the onset of the rifting episode in 2005. These observations of the timing and dynamics of dike-induced seismicity shed light on how multiple dike intrusion episodes fed from one or more mid-segment reservoir(s) contribute to the development of a seafloor spreading segment.

  4. Secular crustal deformation and interplate coupling of the Japanese Islands as deduced from continuous GPS array, 1996 2001

    NASA Astrophysics Data System (ADS)

    El-Fiky, Gamal; Kato, Teruyuki

    2006-08-01

    Data from the nation-wide GPS continuous tracking network that has been operated by the Geographical Survey Institute of Japan since April 1996 were used to study crustal deformation in the Japanese Islands. We first extracted site coordinate from daily SINEX files for the period from April 1, 1996 to February 24, 2001. Since raw time series of station coordinates include coseismic and postseismic displacements as well as seasonal variation, we model each time series as a combination of linear and trigonometric functions and jumps for episodic events. Estimated velocities were converted into a kinematic reference frame [Heki, K., 1996. Horizontal and vertical crustal movements from three-dimensional very long baseline interferometry kinematic reference frame: implication for reversal timescale revision. J. Geophys. Res., 101: 3187-3198.] to discuss the crustal deformation relative to the stable interior of the Eurasian plate. A Least-Squares Prediction technique has been used to segregate the signal and noise in horizontal as well as vertical velocities. Estimated horizontal signals (horizontal displacement rates) were then differentiated in space to calculate principal components of strain. Dilatations, maximum shear strains, and principal axes of strain clearly portray tectonic environments of the Japanese Islands. On the other hand, the interseismic vertical deformation field of the Japanese islands is derived for the same GPS data interval. The GPS vertical velocities are combined with 31 year tide gage records to estimate absolute vertical velocity. The results of vertical deformation show that (1) the existence of clear uplift of about 6 mm/yr in Shikoku and Kii Peninsula, whereas pattern of subsidence is observed in the coast of Kyushu district. This might reflect strong coupling between the Philippine Sea plate and overriding plate at the Nankai Trough and weak coupling off Kyushu, (2) no clear vertical deformation pattern exists along the Pacific coast of northeastern Japan. This might be due to the long distance between the plate boundary (Japan trench) and overriding plate where GPS sites are located, (3) significant uplift is observed in the southwestern part of Hokkaido and in northeastern Tohoku along the Japan Sea coast. This is possibly due to the viscoelastic rebound of the 1983 Japan Sea ( Mw 7.7) and the 1993 Hokkaido-Nansei-Oki ( Mw 7.8) earthquakes and/or associated with distributed compression of incipient subduction there. We then estimate the elastic deformation of the Japanese Islands caused by interseismic loading of the Pacific and Philippine Sea subduction plates. The elastic models account for most of the observed horizontal velocity field if the subduction movement of the Philippine Sea Plate is 100% locked and if that of the Pacific Plate is 70% locked. However, the best fit for vertical velocity ranges from 80% to 100% coupling factor in southwestern Japan and only 50% in northeastern Japan. Since horizontal data does not permit the separation of rigid plate motion and interplate coupling because horizontal velocities include both contributions, we used the vertical velocities to discriminate between them. So, we can say there is strong interplate coupling (80%-100%) over the Nankaido subduction zone, whereas it is about 50% only over the Kurile-Japan trench.

  5. 3-D Structure of Arcade Type Flares Deduced from Soft X-Ray Observations of a Homologous Flare Series

    NASA Astrophysics Data System (ADS)

    Morita, S.; Uchida, Y.; Hirose, S.

    2002-01-01

    In the solar flare problems, no ultimate model that matches observations has been established. One of the reasons for this is due to the restrictions in the observational data lacking information about the third dimension. Thus, many researchers have tried to get information about the three dimensional (3-D) coronal structures by using various techniques or ideas; like movie analysis, calculations using vector or line-of-sight components of photospheric magnetic data, and etc.. In the near future, a mission named STEREO which will obtain information about the 3-D coronal structures from two satellites, is planned. In the present paper, we noted the homology in a homologous flare series of February 1992. We derived a 3-D coronal structures by making use of the images obtained from the three different sight-lines at some common phases in them with Yohkoh SXT. The result of this analysis has made it clear that the so-called ``cusped arcade'' at the maximum phase in the well-known 1992 February 21 flare is, contrary to the general views, an ``elongated arch'' seen with a shallow oblique angle. It is not the ``flare arcade'' seen axis-on as widely conceived. This elongated arch coincides roughly with a diagonal of the main body of the "soft X-ray arcade" that came up later. The magnetic structure causing the flare as a whole turned out in this analysis to be a structure with quadruple magnetic sources. The relative locations of these four characteristic sources stayed almost the same throughout the period of this homologous flare series, determining the fundamental shape of this homologous series. We also examined the corresponding features for other similar events, also using information from other satellites, and will report the results.

  6. Molecular cloning, coding nucleotides and the deduced amino acid sequence of P-450BM-1 from Bacillus megaterium.

    PubMed

    He, J S; Ruettinger, R T; Liu, H M; Fulco, A J

    1989-12-22

    The gene encoding barbiturate-inducible cytochrome P-450BM-1 from Bacillus megaterium ATCC 14581 has been cloned and sequenced. An open reading frame in the 1.9 kb of cloned DNA correctly predicted the NH2-terminal sequence of P-450BM-1 previously determined by protein sequencing, and, in toto, predicted a polypeptide of 410 amino acid residues with an Mr of 47,439. The sequence is most, but less than 27%, similar to that of P-450CAM from Pseudomonas putida, so that P-450BM-1 clearly belongs to a new P-450-gene family, distinct especially from that of the P-450 domain of P-450BM-3, a barbiturate-inducible single polypeptide cytochrome P-450:NADPH-P-450 reductase from the same strain of B. megaterium (Ruettinger, R.T., Wen, L.-P. and Fulco, A.J. (1989) J. Biol. Chem. 264, 10987-10995). PMID:2597681

  7. Surface processes on the asteroid deduced from the external 3D shapes and surface features of Itokawa particles

    NASA Astrophysics Data System (ADS)

    Tsuchiyama, A.; Matsumoto, T.

    2015-10-01

    Particles on the surface of S-type Asteroid 25143 Itokawa were successfully recovered by the Hayabusa mission of JAXA (e.g., [1,2]). They are not only the first samples recovered from an asteroid, but also the second extraterrestrial regolith to have been sampled, the first being the Moon by Apollo and Luna missions. The analysis of tiny sample particles (20-200 μm) shows that the Itokawa surface material is consistent with LL chondrites suffered by space weathering as expected and brought an end to the origin of meteorites (e.g., [2-4]). In addition, the examination of Itokawa particles allow studies of surface processes on the asteroid because regolith particles can be regarded as an interface with the space environment, where the impacts of small objects and irradiation by the solar wind and galactic cosmic rays should have been recorded. External 3D shapes and surface features of Itokawa regolith particles were examined. Two kinds of surface modification, formation of space-weathering rims mainly by solar wind implantation and surface abrasion by grain migration, were recognized. Spectral change of the asteroid proceeded by formation of space-weathering rims and refreshment of the regolith surfaces. External 3D shapes and surface morphologies of the regolith particles can provide information about formation and evolution history of regolith particles in relation to asteroidal surface processes. 3D shapes of Itokawa regolith particles were obtained using microtomography [3]. The surface nanomiromorpholgy of Itokawa particles were also observed using FE-SEM [5]. However, the number of particles was limited and genial feature on the surface morphology has not been understood. In this study, the surface morphology of Itokawa regolith particles was systematically investigated together with their 3D structures.

  8. Late Holocene climates of the Near East deduced from Dead Sea level variations and modern regional winter rainfall

    NASA Astrophysics Data System (ADS)

    Enzel, Yehouda; Bookman (Ken Tor), Revital; Sharon, David; Gvirtzman, Haim; Dayan, Uri; Ziv, Baruch; Stein, Mordechai

    2003-11-01

    The Dead Sea is a terminal lake of one of the largest hydrological systems in the Levant and may thus be viewed as a large rain gauge for the region. Variations of its level are indicative of the climate variations in the region. Here, we present the decadal- to centennial-resolution Holocene lake-level curve of the Dead Sea. Then we determine the regional hydroclimatology that affected level variations. To achieve this goal we compare modern natural lake-level variations and instrumental rainfall records and quantify the hydrology relative to lake-level rise, fall, or stability. To quantify that relationship under natural conditions, rainfall data pre-dating the artificial Dead Sea level drop since the 1960s are used. In this respect, Jerusalem station offers the longest uninterrupted pre-1960s rainfall record and Jerusalem rains serve as an adequate proxy for the Dead Sea headwaters rainfall. Principal component analysis indicates that temporal variations of annual precipitation in all stations in Israel north of the current 200 mm yr -1 average isohyet during 1940-1990 are largely synchronous and in phase (˜70% of the total variance explained by PC1). This station also represents well northern Jordan and the area all the way to Beirut, Lebanon, especially during extreme drought and wet spells. We (a) determine the modern, and propose the past regional hydrology and Eastern Mediterranean (EM) climatology that affected the severity and length of droughts/wet spells associated with multiyear episodes of Dead Sea level falls/rises and (b) determine that EM cyclone tracks were different in average number and latitude in wet and dry years in Jerusalem. The mean composite sea level pressure and 500-mb height anomalies indicate that the potential causes for wet and dry episodes span the entire EM and are rooted in the larger-scale northern hemisphere atmospheric circulation. We also identified remarkably close association (within radiocarbon resolution) between climatic changes in the Levant, reflected by level changes, and culture shifts in this region.

  9. Late Quaternary East Asian monsoon evolution deduced from elemental XRF scanning data in the western South China Sea

    NASA Astrophysics Data System (ADS)

    He, Z.; Liu, Z.; Li, J.; Xie, X.

    2010-12-01

    The East Asian monsoon system dominates seasonal patterns of precipitation and runoff and causes monsoon-induced upwelling off middle Vietnam in the western South China Sea. Our investigation is to decipher the evolution of the East Asian monsoon variations during late Quaternary by analyzing high-resolution elemental XRF scanning data from Core MD05-2899 (13°47.66'N, 112°10.89'E, water depth 2393 m), which is located in the western South China Sea upwelling region. Oxygen isotope results indicate that the 38.86 m long core spans over the last 533 ka. The elemental XRF scanning data present clear glacial-interglacial variations for most of elements. We choose K, Ti, and Zr as proxies of terrigenous input, and Ca and Ba as indicators of nutrient and sea surface productivity. Generally, coherent downcore variations in K/Ti, Zr/Ti, Ba/Ti and Ca/Ti ratios indicate obvious glacial-interglacial cyclicity. The highest element ratios occur during interglacial maxima, indicating that both terrigenous input and sea surface productivity increased when the enhanced East Asia summer monsoon causes intensified precipitation, runoff, and upwelling. In contrast, during the glacials the element ratios decreased when the East Asian summer monsoon was weakened. In addition, the Ba/Ti ratio along with the carbonate mass accumulation rate present much higher values in MIS 3 and 9, reflecting the stronger East Asian summer monsoon activity.

  10. Ionospheric Response to the Total Solar Eclipse of 22 July 2009 as Deduced from VLBI and GPS Data

    NASA Technical Reports Server (NTRS)

    Guo, L.; Shu, F. C.; Zheng, W. M.; Kondo, T.; Ichikawa, R.; Hasegawa, S.; Sekido, M.

    2010-01-01

    A total solar eclipse occurred over China at latitudes of about 30 N on the morning of 22 July 2009, providing a unique opportunity to investigate the influence of the sun on the earth's upper ionosphere. GPS observations from Shanghai GPS Local Network and VLBI observations from stations Shanghai, Urumqi, and Kashima were used to observe the response of TEC to the total solar eclipse. From the GPS data reduction, the sudden decrease of TEC at the time of the eclipse, amounting to 2.8 TECU, and gradual increase of TEC after the eclipse were found by analyzing the diurnal variations. More distinctly, the variations of TEC were studied along individual satellite passes. The delay in reaching the minimum level of TEC with the maximum phase of eclipse was 5-10 min. Besides, we also compared the ionospheric activity derived from different VLBI stations with the GPS results and found a strong correlation between them.

  11. Paleoenvironmental conditions and strontium isotope stratigraphy in the Paleogene Gafsa Basin (Tunisia) deduced from geochemical analyses of phosphatic fossils

    NASA Astrophysics Data System (ADS)

    Kocsis, László; Ounis, Anouar; Chaabani, Fredj; Salah, Neili Mohamed

    2013-06-01

    Fossil shark teeth and coprolites from three major phosphorite occurrences in the Gafsa Basin (southwestern Tunisia) were investigated for their geochemical compositions to improve local stratigraphy and to better assess paleoenvironmental conditions. 87Sr/86Sr isotope ratios of shark teeth from the Early Maastrichtian El Haria Formation and from the Early Eocene Métlaoui s.s. Formation yielded Sr isotope ages of 68 ± 1 and 47.9 ± 1.3 Ma, respectively, which accord with the expected stratigraphic positions of these sediments. Conversely, shark teeth from the Paleocene-Eocene Chouabine Formation have large variation in Sr isotope ratios even within individual layers. After statistical treatment and then elimination of certain outlier samples, three age-models are proposed and discussed. The most reasonable solution includes three subsequent Sr ages of 61.8 ± 2.2 Ma, 57.2 ± 1.8 and 54.6 ± 1.6 for layer IX, layers VIII-V and layers IV-0, respectively. Three scenarios are discussed for explanation of the presence of the outliers: (1) diagenesis, (2) re-working and (3) locally controlled seawater Sr isotope ratio. The most plausible account for the higher 87Sr/86Sr ratios relative to the global ocean in some fossils is enhanced intrabasinal re-working due to low sea level. Conversely, the sample with lower 87Sr/86Sr than the global seawater may link to diagenesis or to seawater influenced by weathering of Late Cretaceous marine carbonates, which latter is supported by model calculation as well. The ɛNd values of these fossils are very similar to those reported for Paleogene and Late Cretaceous Tethyan seawater and are compatible with the above interpretations. The relatively low oxygen isotope values in shark teeth from the topmost phosphate bed of the Chouabine Formation, together with the Sr isotope results, point toward recovering better connections with the open sea. These δ18O data reflect elevated ambient temperature, which may link to the Early Eocene Climatic Optimum.

  12. Phosphate mine subsidences deduced from differential interferometry (DInSAR): The Moulares case example (southern Atlas of Tunisia)

    NASA Astrophysics Data System (ADS)

    Ben Hassen, Mehdi; Rebai, Noamen; Deffontaines, Benoit; Turki, Mohamed Moncef; Chaabani, Fredj

    2011-11-01

    Tunisia is submitted to numerous small topographic displacements due to both the geodynamic of the Eurasian-African plates' convergence, and to important anthropic actions such as oil production, underground water pumping, mine extraction and linked post-mining displacements. We propose herein to study the latter and locate, characterize, and quantify small topographic displacement fields due to the production of underground phosphate mines in central Tunisia. After having acquired and processed 17 radar images (ERS 1 and 2) of the central Tunisia (Gafsa area) through Differential Interferometry (DInSAR), we clearly observed local subsidence that we interprete as corresponding to mine exploitation of the underground Moulares Phosphates mines (southern Atlas of Tunisia). Field studies (circular normal faults located above the Phosphate extraction area) confirm the movement revealed by DinSAR. Also, DInSAR allows us to monitor temporal variations of the small vertical displacements on this specific area and since the collapse occurred near an urban area (Moulares city), this problem can be considered a potential anthropic risk.

  13. Proof of concept study with an HER-2 mimotope anticancer vaccine deduced from a novel AAV-mimotope library platform

    PubMed Central

    Singer, Josef; Manzano-Szalai, Krisztina; Fazekas, Judit; Thell, Kathrin; Bentley-Lukschal, Anna; Stremnitzer, Caroline; Roth-Walter, Franziska; Weghofer, Margit; Ritter, Mirko; Pino Tossi, Kerstin; Hörer, Markus; Michaelis, Uwe; Jensen-Jarolim, Erika

    2016-01-01

    ABSTRACT Background: Anticancer vaccines could represent a valuable complementary strategy to established therapies, especially in settings of early stage and minimal residual disease. HER-2 is an important target for immunotherapy and addressed by the monoclonal antibody trastuzumab. We have previously generated HER-2 mimotope peptides from phage display libraries. The synthesized peptides were coupled to carriers and applied for epitope-specific induction of trastuzumab-like IgG. For simplification and to avoid methodological limitations of synthesis and coupling chemistry, we herewith present a novel and optimized approach by using adeno-associated viruses (AAV) as effective and high-density mimotope-display system, which can be directly used for vaccination. Methods: An AAV capsid display library was constructed by genetically incorporating random peptides in a plasmid encoding the wild-type AAV2 capsid protein. AAV clones, expressing peptides specifically reactive to trastuzumab, were employed to immunize BALB/c mice. Antibody titers against human HER-2 were determined, and the isotype composition and functional properties of these were tested. Finally, prophylactically immunized mice were challenged with human HER-2 transfected mouse D2F2/E2 cells. Results: HER-2 mimotope AAV-vaccines induced antibodies specific to human HER-2. Two clones were selected for immunization of mice, which were subsequently grafted D2F2/E2 cells. Both mimotope AAV clones delayed the growth of tumors significantly, as compared to controls. Conclusion: In this study, a novel mimotope AAV-based platform was created allowing the isolation of mimotopes, which can be directly used as anticancer vaccines. The example of trastuzumab AAV-mimotopes demonstrates that this vaccine strategy could help to establish active immunotherapy for breast-cancer patients.

  14. WBN-1 Cycle 10 TPBAR Tritium Release, Deduced From Analysis of RCS Data TTP-1-3046-00, Rev 0

    SciTech Connect

    Shaver, Mark W.; Niehus, Mark T.; Love, Edward F.

    2012-02-19

    This document contains the calculation of the TPBAR tritium release from the Mark 9.2 design TPBARs irradiated in WBN cycle 10. The calculation utilizes the generalized cycle analysis methodology given in TTP-1-3045 Rev. 0.

  15. Nitrate dynamics in agricultural catchments deduced from groundwater dating and long-term nitrate monitoring in surface- and groundwaters.

    PubMed

    Aquilina, L; Vergnaud-Ayraud, V; Labasque, T; Bour, O; Molénat, J; Ruiz, L; de Montety, V; De Ridder, J; Roques, C; Longuevergne, L

    2012-10-01

    Although nitrate export in agricultural catchments has been simulated using various types of models, the role of groundwater in nitrate dynamics has rarely been fully taken into account. We used groundwater dating methods (CFC analyses) to reconstruct the original nitrate concentrations in the groundwater recharge in Brittany (Western France) from 1950 to 2009. This revealed a sharp increase in nitrate concentrations from 1977 to 1990 followed by a slight decrease. The recharge concentration curve was then compared with past chronicles of groundwater concentration. Groundwater can be interpreted as resulting from the annual dilution of recharge water in an uncontaminated aquifer. Two aquifers were considered: the weathered aquifer and the deeper fractured aquifer. The nitrate concentrations observed in the upper part of the weathered aquifer implied an annual renewal rate of 27 to 33% of the reservoir volume while those in the lower part indicated an annual renewal rate of 2-3%. The concentrations in the deep fractured aquifer showed an annual renewal rate of 0.1%. The river concentration can be simulated by combining these various groundwater reservoirs with the recharge. Winter and summer waters contain i) recharge water, or water from the variably saturated zone with rapid transfer and high nitrate concentrations, and ii) a large contribution (from 35 to 80% in winter and summer, respectively) from the lower part of the aquifer (lower weathered aquifer and deep fractured aquifer). This induces not only a relatively rapid response of the catchment to variations in agricultural pressure, but also a potential inertia which has to be taken into account.

  16. Extrapolating surface structures to depth in transpressional systems: the role of rheology and convergence angle deduced from analogue experiments

    NASA Astrophysics Data System (ADS)

    Hsieh, Shang Yu; Neubauer, Franz; Cloetingh, Sierd; Willingshofer, Ernst; Sokoutis, Dimitrios

    2014-05-01

    The internal structure of major strike-slip faults is still poorly understood, particularly how the deep structure could be inferred from its surface expression (Molnar and Dayem, 2011 and references therein). Previous analogue experiments suggest that the convergence angle is the most influential factor (Leever et al., 2011). Further analogue modeling may allow a better understanding how to extrapolate surface structures to the subsurface geometry of strike-slip faults. Various scenarios of analogue experiments were designed to represent strike-slip faults in nature from different geological settings. As such key parameters, which are investigated in this study include: (a) the angle of convergence, (b) the thickness of brittle layer, (c) the influence of a rheological weak layer within the crust, and (d) influence of a thick and rheologically weak layer at the base of the crust. The latter aimed to simulate the effect of a hot metamorphic core complex or an alignment of uprising plutons bordered by a transtensional/transpressional strike-slip fault. The experiments are aimed to explain first order structures along major transcurrent strike-slip faults such as the Altyn, Kunlun, San Andrea and Greendale (Darfield earthquake 2010) faults. The preliminary results show that convergence angle significantly influences the overall geometry of the transpressive system with greater convergence angles resulting in wider fault zones and higher elevation. Different positions, densities and viscosities of weak rheological layers have not only different surface expressions but also affect the fault geometry in the subsurface. For instance, rheological weak material in the bottom layer results in stretching when experiment reaches a certain displacement and a buildup of a less segmented, wide positive flower structure. At the surface, a wide fault valley in the middle of the fault zone is the reflection of stretching along the velocity discontinuity at depth. In models with a thin and rheologically weaker layer in the middle of the brittle layer, deformation is distributed over more faults and the geometry of the fault zone below and above the weak zone shows significant differences, suggesting that the correlation of structures across a weak layer has to be supported by geophysical data, which help constraining the geometry of the deep part. This latter experiment has significantly similar phenomena in reality, such as few pressure ridges along Altyn fault. The experimental results underline the need to understand the role of the convergence angle and the influence of rheology on fault evolution, in order to connect between surface deformation and subsurface geometry. References Leever, K. A., Gabrielsen, R. H., Sokoutis, D., Willingshofer, E., 2011. The effect of convergence angle on the kinematic evolution of strain partitioning in transpressional brittle wedges: Insight from analog modeling and high-resolution digital image analysis. Tectonics, 30(2), TC2013. Molnar, P., Dayem, K.E., 2010. Major intracontinental strike-slip faults and contrasts in lithospheric strength. Geosphere, 6, 444-467.

  17. Direction and timing of uplift propagation in the Peruvian Andes deduced from molecular phylogenetics of highland biotaxa

    NASA Astrophysics Data System (ADS)

    Picard, Damien; Sempere, Thierry; Plantard, Olivier

    2008-07-01

    Physical paleoaltimetric methods are increasingly used to estimate the amount and timing of surface uplift in orogens. Because the rise of mountains creates new ecosystems and triggers evolutionary changes, biological data may also be used to assess the development and timing of regional surface uplift. Here we apply this idea to the Peruvian Andes through a molecular phylogeographic and phylochronologic analysis of Globodera pallida, a potato parasite nematode that requires cool temperatures and thus thrives above 2.0-2.5 km in these tropical highlands. The Peruvian populations of this species exhibit a clear evolutionary pattern with deeper, more ancient lineages occurring in Andean southern Peru and shallower, younger lineages occurring progressively northwards. Genetically diverging G. pallida populations thus progressively colonized highland areas as these were expanding northwards, demonstrating that altitude in the Peruvian Andes was acquired longitudinally from south to north, i.e. in the direction of decreasing orogenic volume. This phylogeographic structure is recognized in other, independent highland biotaxa, and point to the Central Andean Orocline (CAO) as the region where high altitudes first emerged. Moreover, molecular clocks relative to Andean taxa, including the potato-tomato group, consistently estimate that altitudes high enough to induce biotic radiation were first acquired in the Early Miocene. After calibration by geological and biological tie-points and intervals, the phylogeny of G. pallida is used as a molecular clock, which estimates that the 2.0-2.5 km threshold elevation range was reached in the Early Miocene in southernmost Peru, in the Middle and Late Miocene in the Abancay segment (NW southern Peru), and from the latest Miocene in central and northern Peru. Although uncertainties attached to phylochronologic ages are significantly larger than those derived from geochronological methods, these results are fairly consistent with coeval geological phenomena along the Peruvian Andes. They strongly suggest that orogenic volume initially developed in the CAO during most of the Miocene until a breakthrough in the latest Miocene allowed the northward propagation of crustal thickening into central and northern Peru, possibly by ductile crustal flow from the CAO. Such a combined phylogeographic and phylochronologic approach to regional uplift opens perspectives to estimate the direction(s) and timing of acquisition of altitude over other Cenozoic orogens.

  18. Tectonics of the baikal rift deduced from volcanism and sedimentation: a review oriented to the Baikal and Hovsgol lake systems.

    PubMed

    Ivanov, Alexei V; Demonterova, Elena I

    2009-01-01

    As known from inland sedimentary records, boreholes, and geophysical data, the initiation of the Baikal rift basins began as early as the Eocene. Dating of volcanic rocks on the rift shoulders indicates that volcanism started later, in the Early Miocene or probably in the Late Oligocene. Prominent tectonic uplift took place at about 20 Ma, but information (from both sediments and volcanics) on the initial stage of the rifting is scarce and incomplete. A comprehensive record of sedimentation derived from two stacked boreholes drilled at the submerged Akademichesky ridge indicates that the deep freshwater Lake Baikal existed for at least 8.4 Ma, while the exact formation of the lake in its roughly present-day shape and volume is unknown. Four important events of tectonic/environmental changes at about approximately 7, approximately 5, approximately 2.5, and approximately 0.1 Ma are seen in that record. The first event probably corresponds to a stage of rift propagation from the historical center towards the wings of the rift system. Rifting in the Hovsgol area was initiated at about this time. The event of ~5 Ma is a likely candidate for the boundary between slow and fast stages of rifting. It is reflected in a drastic change of sedimentation rate due to isolation of the Akademichesky ridge from the central and northern Lake Baikal basins. The youngest event of 0.1 Ma is reflected by the (87)0Sr/ (86)Sr ratio increase in Lake Baikal waters and probably related to an increasing rate of mountain growth (and hence erosion) resulting from glacial rebounding. The latter is responsible for the reorganization of the outflow pattern with the termination of the paleo-Manzurka outlet and the formation of the Angara outlet. The event of approximately 2.5 Ma is reflected in the decrease of the (87)Sr/(86)Sr and Na/Al ratios in Lake Baikal waters. We suggest that it is associated with a decrease of the dust load due to a reorganization of the atmospheric circulations in Mainland Asia. All these tectonic and climatic events could (and actually did) influence the biota of Lake Baikal. The Hovsgol rift basin was shaped to its recent form between 5.5 and 0.4 Ma. However, freshwater Lake Hovsgol appeared only in the latest pre-Holocene time as a result of meltwater inflow and increase of atmospheric precipitations during the Bølling-Allerød warming. Prior to this, a significantly smaller, saline outflow-free precursor of Lake Hovsgol existed. It explains why two, now connected, lakes of similar water chemistry within similar climatic and tectonic conditions differ so much in their biodiversity.

  19. Collective aspects deduced from time-dependent microscopic mean-field with pairing: Application to the fission process

    NASA Astrophysics Data System (ADS)

    Tanimura, Yusuke; Lacroix, Denis; Scamps, Guillaume

    2015-09-01

    Given a set of collective variables, a method is proposed to obtain the associated conjugated collective momenta and masses starting from a microscopic time-dependent mean-field theory. The construction of pairs of conjugated variables is the first step to bridge microscopic and macroscopic approaches. The method is versatile and can be applied to study a large class of nuclear processes. An illustration is given here with the fission of 258Fm. Using the quadrupole moment and eventually higher-order multipole moments, the associated collective masses are estimated along the microscopic mean-field evolution. When more than one collective variable is considered, it is shown that the off-diagonal matrix elements of the inertia play a crucial role. Using the information on the quadrupole moment and associated momentum, the collective evolution is studied. It is shown that dynamical effects beyond the adiabatic limit are important. Nuclei formed after fission tend to stick together for a longer time leading to a dynamical scission point at a larger distance between nuclei compared to the one anticipated from the adiabatic energy landscape. The effective nucleus-nucleus potential felt by the emitted nuclei is finally extracted.

  20. Multi-scale Holocene Asian monsoon variability deduced from a twin-stalagmite record in southwestern China

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Wang, Yongjin; Cheng, Hai; Edwards, Richard Lawrence; Shen, Chuan-Chou; Liu, Dianbing; Shao, Qingfeng; Deng, Chao; Zhang, Zhenqiu; Wang, Quan

    2016-07-01

    We present two isotopic (δ18O and δ13C) sequences of a twin-stalagmite from Zhuliuping Cave, southwestern China, with 230Th dates from 14.6 to 4.6 ka. The stalagmite δ18O record characterizes orbital- to decadal-scale variability of Asian summer monsoon (ASM) intensity, with the Holocene optimum period (HOP) between 9.8 and 6.8 ka BP which is reinforced by its co-varying δ13C data. The large multi-decadal scale amplitude of the cave δ18O indicates its high sensitivity to climate change. Four centennial-scale weak ASM events during the early Holocene are centered at 11.2, 10.8, 9.1 and 8.2 ka. They can be correlated to cold periods in the northern high latitudes, possibly resulting from rapid dynamics of atmospheric circulation associated with North Atlantic cooling. The 8.2 ka event has an amplitude more than two-thirds that of the Younger Dryas (YD), and is significantly stronger than other cave records in the Asia monsoon region, likely indicating a more severe dry climate condition at the cave site. At the end of the YD event, the δ13C record lags the δ18O record by 300-500 yr, suggesting a multi-centennial slow response of vegetation and soil processes to monsoon enhancement.

  1. Culinary herbs and spices: their bioactive properties, the contribution of polyphenols and the challenges in deducing their true health benefits.

    PubMed

    Opara, Elizabeth I; Chohan, Magali

    2014-10-22

    Herbs and spices have been used for both culinary and medicinal purposes for centuries. Over the last decade, research into their role as contributors of dietary polyphenols, known to possess a number of properties associated with reducing the risk of developing chronic non-communicable diseases, has increased. However, bearing in mind how these foods are consumed, normally in small quantities and in combination with other foods, it is unclear what their true benefit is from a health perspective. The aim of this review is to use the literature to discuss how preparative and digestive processes, bioavailability and interactions between foods may influence the bioactive properties of these foods, and whether or not polyphenols are responsible for these properties. Furthermore, this review aims to highlight the challenges that need to be addressed so as to determine the true benefits of these foods and the mechanisms of action that underpin their purported efficacy.

  2. Towards the kinetics of diagenetic overprint processes deduced from laboratory-based hydrothermal alteration of modern Arctica islandica shell material

    NASA Astrophysics Data System (ADS)

    Casella, Laura A.; Griesshaber, Erika; Mavromatis, Vasileios; Dietzel, Martin; Immenhauser, Adrian; Schmahl, Wolfgang W.

    2016-04-01

    Benthic and nektonic marine biogenic carbonate archives represent the foundation of numerous studies aiming at paleo-environment reconstructions. However, living organisms are not in thermodynamic equilibrium as they form local chemical environments for physiologic processes such as biological mineralization of their hard tissues. This disequilibrium is not sustained after death and all biological tissues are altered by equilibration with the surrounding environment: diagenesis. To understand transformation during diagenesis we performed laboratory-based hydrothermal alteration experiments on Arctica islandica shells at four different temperatures between 100 °C and 175 °C treated in simulated meteoric and burial waters, respectively. We investigated, relative to unaltered shells, the kinetics of Arctica islandica bioaragonite to calcite transition as well as microstructural- and nanostructural characteristics of the altered shells with X-ray diffraction, micro-Raman, high-resolution SEM and EBSD. At hydrothermal treatment at 100 °C bioaragonite - although metastable at 1 bar - does not transform to calcite, even in meteoric fluids and over a time period of 28 days. We noted a drastic recrystallization from the initial fine-grained fractal microstructure and pronounced axial texture to a new and still fine-grained microstructure with an almost randomized orientation distribution. At 175 °C the transformation to coarse-grained calcite is complete after 8 days. Calcite formation starts after a passive incubation period of 4 days; after 6 days the aragonite is almost completely transformed. In solutions simulating meteoric water the grain size of the newly formed calcite reaches 100-150 μm, while in burial fluids the calcite reaches sizes in the 1mm range during 28 days of alteration. Phase transformation proceeds where the hydrothermal fluid is in contact with the aragonite: at shell surfaces, around pores and in growth lines. Our observations lead us to the following conclusions: Surprisingly, we do not only observe transformation of nominally metastable bioaragonite to calcite, we also observe recrystallization of bioaragonite to aragonite and biocalcite to calcite. All these types of recrystallization significantly reduce the crystallographic preferred orientation, which is characteristic for the original biological hard tissue. The newly formed crystals do not nucleate epitaxially on the original material, and this causes the randomized crystallographic orientation after diagenetic overprinting. The driving force for recrystallization is due to internal stresses caused by organic matrices and interface energies related to the nanoscale fabric of the biomineral. The pores left behind by decomposed organic matrix apparently serve as nucleation sites for newly formed mineral.

  3. A UT/LS ozone climatology of the nineteen seventies deduced from the GASP aircraft measurement program

    NASA Astrophysics Data System (ADS)

    Schnadt Poberaj, C.; Staehelin, J.; Brunner, D.; Thouret, V.; Mohnen, V.

    2007-11-01

    We present ozone measurements of the Global Atmospheric Sampling Program (GASP) performed from four commercial and one research aircraft in the late 1970s. The GASP quality assurance and control program was reviewed, and an ozone climatology of the upper troposphere and lower stratosphere (UT/LS) of the years 1975-1979 was built. The data set was estimated to have an overall uncertainty of 9% or 3 ppb whichever is greater for the first two years and 4% or 3 ppb for the remaining years, i.e. after implementation of silicone rubber membranes in the pumps. Two cases of nearly coincident flights of two GASP airliners along the same flight route, and the comparison with independent observations from the literature, including ozonesondes and aircraft campaigns, indicate that the ozone measurements are of high quality. The UT/LS climatology of the GASP data set is in general agreement with that derived from MOZAIC in the 1990s in regions covered by both programmes. GASP provides unique large-scale climatological information on UT/LS ozone above the northern hemisphere Pacific region, which is not covered by MOZAIC. There, the GASP climatology confirms several characteristic features derived from individual research aircraft campaigns and from ozone soundings. In particular, summertime ozone in the UT over the midlatitude eastern Pacific Ocean was significantly lower in the 1970s than over the American continent. The generally lower ozone concentrations in the tropics near the dateline as compared to farther east are indicative of convective uplifting of ozone poor air from the marine boundary layer.

  4. Vegetation history of central Chukotka deduced from permafrost paleoenvironmental records of the El'gygytgyn Impact Crater

    NASA Astrophysics Data System (ADS)

    Andreev, A. A.; Morozova, E.; Fedorov, G.; Schirrmeister, L.; Bobrov, A. A.; Kienast, F.; Schwamborn, G.

    2012-08-01

    Frozen sediments from three cores bored in the permafrost surrounding the El'gygytgyn Impact Crater Lake have been studied for pollen, non-pollen palynomorphs, plant macrofossils and rhizopods. The palynological study of these cores contributes to a higher resolution of time intervals presented in a poor temporal resolution in the lacustrine sediments; namely the Allerød and succeeding periods. Moreover, the permafrost records better reflect local environmental changes, allowing a more reliable reconstruction of the local paleoenvironments. The new data confirm that shrub tundra with dwarf birch, shrub alder and willow dominated the lake surroundings during the Allerød warming. Younger Dryas pollen assemblages reflect abrupt changes to grass-sedge-herb dominated environments reflecting significantly drier and cooler climate. Low shrub tundra with dwarf birch and willow dominate the lake vicinity at the onset of the Holocene. The find of larch seeds indicate its local presence around 11 000 cal yr BP and, thus a northward shift of treeline by about 100 km during the early Holocene thermal optimum. Forest tundra with larch and shrub alder stands grew in the area during the early Holocene. After ca. 3500 cal yr BP similar-to-modern plant communities became common in the lake vicinity.

  5. Grand solar minima and maxima deduced from 10Be and 14C: magnetic dynamo configuration and polarity reversal

    NASA Astrophysics Data System (ADS)

    Inceoglu, F.; Simoniello, R.; Knudsen, M. F.; Karoff, C.; Olsen, J.; Turck-Chiéze, S.; Jacobsen, B. H.

    2015-05-01

    Aims: This study aims to improve our understanding of the occurrence and origin of grand solar maxima and minima. Methods: We first investigate the statistics of peaks and dips simultaneously occurring in the solar modulation potentials reconstructed using the Greenland Ice Core Project (GRIP) 10Be and IntCal13 14C records for the overlapping time period spanning between ~1650 AD to 6600 BC. Based on the distribution of these events, we propose a method to identify grand minima and maxima periods. By using waiting time distribution analysis, we investigate the nature of grand minima and maxima periods identified based on the criteria as well as the variance and significance of the Hale cycle during these kinds of events throughout the Holocene epoch. Results: Analysis of grand minima and maxima events occurring simultaneously in the solar modulation potentials, reconstructed based on the 14C and the 10Be records, shows that the majority of events characterized by periods of moderate activity levels tend to last less than 50 years: grand maxima periods do not last longer than 100 years, while grand minima can persist slightly longer. The power and the variance of the 22-year Hale cycle increases during grand maxima and decreases during grand minima, compared to periods characterized by moderate activity levels. Conclusions: We present the first reconstruction of the occurrence of grand solar maxima and minima during the Holocene based on simultaneous changes in records of past solar variability derived from tree-ring 14C and ice-core 10Be, respectively. This robust determination of the occurrence of grand solar minima and maxima periods will enable systematic investigations of the influence of grand solar minima and maxima episodes on Earth's climate.

  6. Local fluctuations of ozone from 16 km to 45 km deduced from in situ vertical ozone profile

    NASA Technical Reports Server (NTRS)

    Moreau, G.; Robert, C.

    1994-01-01

    A vertical ozone profile obtained by an in situ ozone sonde from 16 km to 45 km, has allowed to observe local ozone concentration variations. These variations can be observed, thanks to a fast measurement system based on a UV absorption KrF excimer laser beam in a multipass cell. Ozone standard deviation versus altitude calculated from the mean is derived. Ozone variations or fluctuations are correlated with the different dynamic zones of the stratosphere.

  7. Concentration of ore elements in magmatic melts and natural fluids as deduced from data on inclusions in minerals

    NASA Astrophysics Data System (ADS)

    Naumov, V. B.; Girnis, A. V.; Dorofeeva, V. A.; Kovalenker, V. A.

    2016-07-01

    Based on intergration of the published data on composition of inclusions in minerals and quenched glasses, the mean concentrations of 24 ore elements have been calculated for magmatic silicate melts formed in main geodynamic settings of the Earth and in natural fluids. The mean glass compositions normalized to the primitive mantle correlate with the partition coefficient between olivine and the basic melt. It is established that the degree of enrichment in ore elements depending on geodynamic setting is controlled by various contribution of fluids to the element transfer and accumulation. The ratios of element contents in each geodynamic setting to the mean concentrations of elements over all settings in the Earth have been calculated.

  8. Local and Catchment-Scale Water Storage Changes in Northern Benin Deduced from Gravity Monitoring at Various Time-Scales

    NASA Astrophysics Data System (ADS)

    Hinderer, J.; Hector, B.; Séguis, L.; Descloitres, M.; Cohard, J.; Boy, J.; Calvo, M.; Rosat, S.; Riccardi, U.; Galle, S.

    2013-12-01

    Water storage changes (WSC) are investigated by the mean of gravity monitoring in Djougou, northern Benin, in the frame of the GHYRAF (Gravity and Hydrology in Africa) project. In this area, WSC are 1) part of the control system for evapotranspiration (ET) processes, a key variable of the West-African monsoon cycle and 2) the state variable for resource management, a critical issue in storage-poor hard rock basement contexts such as in northern Benin. We show the advantages of gravity monitoring for analyzing different processes in the water cycle involved at various time and space scales, using the main gravity sensors available today (FG5 absolute gravimeter, superconducting gravimeter -SG- and CG5 micro-gravimeter). The study area is also part of the long-term observing system AMMA-Catch, and thus under intense hydro-meteorological monitoring (rain, soil moisture, water table level, ET ...). Gravity-derived WSC are compared at all frequencies to hydrological data and to hydrological models calibrated on these data. Discrepancies are analyzed to discuss the pros and cons of each approach. Fast gravity changes (a few hours) are significant when rain events occur, and involve different contributions: rainfall itself, runoff, fast subsurface water redistribution, screening effect of the gravimeter building and local topography. We investigate these effects and present the statistical results of a set of rain events recorded with the SG installed in Djougou since July 2010. The intermediate time scale of gravity changes (a few days) is caused by ET and both vertical and horizontal water redistribution. The integrative nature of gravity measurements does not allow to separate these different contributions, and the screening from the shelter reduces our ability to retrieve ET values. Also, atmospheric corrections are critical at such frequencies, and deserve some specific attention. However, a quick analysis of gravity changes following rain events shows that the values are in accordance with expected ET values (up to about 5mm/day). Seasonal WSC are analyzed since 2008 using FG5 absolute gravity measurements four times a year and since 2010 using the continuous SG time series. They can reach up to 12 microGal (≈270mm) and show a clear interannual variability, as can be expected from rainfall variability in the area. This data set allows some estimates of an average specific yield for the local aquifer, together with a scaling factor for Magnetic Resonance Soundings-derived water content.

  9. Simulation of EAS properties on the basis of high energy interaction model deduced from the accelerator data

    NASA Technical Reports Server (NTRS)

    Kubiak, G.; Szabelski, J.; Wdeyozyk, J.; Wolfendale, A. W.

    1985-01-01

    Calculations of extensive air showers in atmosphere were performed using formulae describing p-p and p-air nucleus interactions. The formulae fitted to the accelerator data were extrapolated taking the same trend up to 10 to the 16 eV. Above that energy it was assumed that the degree of scaling violating/alpha-parameter/ is saturating or even decreasing. The latter assumption follows from earlier work where it was found that without this restriction shower maxima at the highest energies are located too high in the atmosphere. Results of calculations have been compared with experimental data. The comparison was made separately for the curves obtained from the so called equal intensity cuts and for the Cerenkov data.

  10. Relationship between surface and subsurface structures of the northern Atlas foreland of Tunisia deduced from regional gravity analysis

    NASA Astrophysics Data System (ADS)

    Frifita, N.; Arfaoui, M. S.; Zargouni, F.

    2016-08-01

    Gravity data were analyzed in the northern Atlas of Tunisia in order to identify the deep structures of the region and their relationship to the geological outcrop. The analysis based on the Bouguer gravity maps related to upward continuation at 1, 2, 4, 6, 10 and 12 km. The lineaments obtained by the horizontal gradient method were interpreted as deep faults with two global directions NE–SW and NW–SE related to major tectonic corridors. These lineaments were confirmed by the automatic estimation of depth solutions using the Euler deconvolution technique. By separation between the gravity anomaly bodies in different levels, it shows that almost all of the lineaments are oriented in NE–SW and NW–SE directions. The NW–SE-trending lineaments are related to deep faults and the NE–SW-oriented lineaments define the global direction of the surface, and they are related to shallow structures. 2.5D gravity modeling was used to improve the results obtained by the Maxima and the Euler deconvolution techniques. The 2.5D model points out the variation of depths of the NE–SW-trending major faults. In this study, we demonstrate the relationship between the NE–SW and the NW–SE directions. These two major sets of faults have been determined by the statistical study of the lineaments. This study confirms some faults already recognized or supposed by the classical geological studies, and it also detects a new deep fault masked in the surface, and gives information about major fault depths and the relation between different structures.

  11. OBSERVATIONS OF THE INTERPLANETARY HYDROGEN DURING SOLAR CYCLES 23 AND 24. WHAT CAN WE DEDUCE ABOUT THE LOCAL INTERSTELLAR MEDIUM?

    SciTech Connect

    Vincent, Frédéric E.; Quémerais, Eric; Koutroumpa, Dimitra; Ben-Jaffel, Lotfi; Harris, Walter M.; Clarke, John

    2014-06-20

    Observations of interstellar helium atoms by the Interstellar Boundary Explorer (IBEX) spacecraft in 2009 reported a local interstellar medium (LISM) velocity vector different from the results of the Ulysses spacecraft between 1991 and 2002. The interplanetary hydrogen (IPH), a population of neutrals that fills the space between planets inside the heliosphere, carries the signatures of the LISM and its interaction with the solar wind. More than 40 yr of space-based studies of the backscattered solar Lyα emission from the IPH provided limited access to the velocity distribution, with the first temporal evolution map of the IPH line-shift during solar cycle 23. This work presents the results of the latest IPH observations made by the Hubble Space Telescope's Space Telescope Imaging Spectrograph during solar cycle 24. These results have been compiled with previous measurements, including data from the Solar Wind Anisotropies instrument on the Solar and Heliospheric Observatory. The whole set has been compared to physically realistic models to test both sets of LISM physical parameters as measured by Ulysses and IBEX, respectively. This comparison shows that the LISM velocity vector has not changed significantly since Ulysses measurements.

  12. Quantification of diagenetic overprint processes deduced from fossil carbonate shells and laboratory-based hydrothermal alteration experiments

    NASA Astrophysics Data System (ADS)

    Griesshaber, Erika; Casella, Laura; Mavromatis, Vasileios; Dietzel, Martin; Immenhauser, Adrian; Schmahl, Wolfgang

    2016-04-01

    Benthic and nektonic marine biogenic carbonate archives represent the foundation of numerous studies aiming at reconstructions of past climate dynamics and environmental change. However, living organisms are not in thermodynamic equilibrium and create local chemical environments where physiologic processes such as biomineralization takes place. After the death of the organism the former physiologic disequilibrium conditions are not sustained any more and all biological tissues are altered by equilibration according to the surrounding environment: diagenesis. With increasing diagenetic alteration, the biogenic structure and fingerprint fades away and is replaced by inorganic features. Thus, recrystallization of organism-specific microstructure is a clear indicator for diagenetic overprint. Microstructural data, which mirror recrystallization, are of great value for interpreting geochemical proxies for paleo-environment reconstruction. Despite more than a century of research dealing with carbonate diagenesis, many of the controlling processes and factors are only understood in a qualitative manner. One of the main issues is that diagenetically altered carbonates are usually present as the product of a complex preceding diagenetic pathway with an unknown number of intermediate steps. In this contribution we present and discuss laboratory based alteration experiments with the aim to investigate time-series data sets in a controlled manner. We conducted hydrothermal alteration experiments with modern Arctica islandica (bivalvia) and Notosaria nigricans (brachiopoda) in order to mimic diagenetic overprint. We explore first the potential of electron backscattered diffraction (EBSD) measurements together with statistical data evaluation as a tool to quantify diagenetic alteration of carbonate skeletons. Subsequently, we compare microstructural patterns obtained from experimentally altered shell material with those of fossil specimens that have undergone variable degrees of diagenetic overprint. We intend to come up with a process-oriented understanding of alteration parameters and products as the change in microstructure, texture and mineral phase needs a careful action when it comes to the interpretation of paleoclimate reconstruction data.

  13. Primary structure of bovine pituitary secretory protein I (chromogranin A) deduced from the cDNA sequence

    SciTech Connect

    Ahn, T.G.; Cohn, D.V.; Gorr, S.U.; Ornstein, D.L.; Kashdan, M.A.; Levine, M.A.

    1987-07-01

    Secretory protein I (SP-I), also referred to as chromogranin A, is an acidic glycoprotein that has been found in every tissue of endocrine and neuroendocrine origin examined but never in exocrine or epithelial cells. Its co-storage and co-secretion with peptide hormones and neurotransmitters suggest that it has an important endocrine or secretory function. The authors have isolated cDNA clones from a bovine pituitary lambdagt11 expression library using an antiserum to parathyroid SP-I. The largest clone (SP4B) hybridized to a transcript of 2.1 kilobases in RNA from parathyroid, pituitary, and adrenal medulla. Immunoblots of bacterial lysates derived from SP4B lysognes demonstrated specific antibody binding to an SP4B/..beta..-galactosidase fusion protein (160 kDa) with a cDNA-derived component of 46 kDa. Radioimmunoassay of the bacterial lystates with SP-I antiserum yielded parallel displacement curves of /sup 125/I-labeled SP-I by the SP4B lysate and authentic SP-I. SP4B contains a cDNA of 1614 nucleotides that encodes a 449-amino acid protein (calculated mass, 50 kDa). The nucleotide sequences of the pituitary SP-I cDNA and adrenal medullary SP-I cDNAs are nearly identical. Analysis of genomic DNA suggests that pituitary, adrenal, and parathyroid SP-I are products of the same gene.

  14. Evolution of multicellular animals as deduced from 5S rRNA sequences: a possible early emergence of the Mesozoa.

    PubMed

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S

    1984-06-25

    The nucleotide sequences of 5S rRNA from a mesozoan Dicyema misakiense and three metazoan species, i.e., an acorn-worm Saccoglossus kowalevskii, a moss-animal Bugula neritina, and an octopus Octopus vulgaris have been determined. A phylogenic tree of multicellular animals has been constructed from 73 5S rRNA sequences available at present including those from the above four sequences. The tree suggests that the mesozoan is the most ancient multicellular animal identified so far, its emergence time being almost the same as that of flagellated or ciliated protozoans. The branching points of planarians and nematodes are a little later than that of the mesozoan but are clearly earlier than other metazoan groups including sponges and jellyfishes. Many metazoan groups seem to have diverged within a relatively short period. PMID:6539911

  15. The structure of the upper crust in the Alps-Apennines boundary region deduced from refraction seismic data

    NASA Astrophysics Data System (ADS)

    Biella, G. C.; Gelati, R.; Maistrello, M.; Mancuso, M.; Massiotta, P.; Scarascia, S.

    1987-10-01

    Analysis of data gathered during the 1983 European Geotraverse southern segment (EGT-S '83) experiments in the region extending from the Emilia-Liguria Apennines to the western Alpine Arc together with data from seismic profiles in the northwestern Apennines accumulated within the framework of the Alps-Apennines Orogene Study Group indicate new details on the structure of the upper crust east and west of the Alps-Apennines boundary. The main results of this analysis centre on two areas. In the Piedmont Tertiary Basin we could determine the depocenter configurations of the 6-7 km thick terrigenous sequence and differentiate the tectonic units in the Piedmont (Alpine) and the Ligurian (Apennine) domains within the basement. In the other area, the Insubric domain underneath the Ligurian nappes of the northern Apennines, we found indications of tectonic doubling within the terrigenous-carbonate sequence in which thrusting attenuates towards the underlying basement, detected at a depth of 12-15 km. In addition, we found that, on a line from the Emilia Apennines to the Monferrato Hills, displacement of the Ligurian nappes over the Insubric domain diminishes to nearly one-third its original extent.

  16. Land Deformation at the Thessaloniki - Giannitsa Plain (Greece) Deduced from 20- years Radar Observations using Persistent Scatterers Techniques

    NASA Astrophysics Data System (ADS)

    Svigkas, N.; Papoutsis, I.; Loupasakis, K.; Kiratzi, A. A.; Kontoes, C.

    2015-12-01

    We present the detected deformation and interpret the results in the light of ground-truth hydrological data, for the Thessaloniki-Giannitsa plain, the largest deltaic plain in Greece, encircled by Mounts Vermio, Paiko and Pieria. The contemporary morphology was gradually developed from the tectonic variations of the upper Pleistocene. The area has been subjected to many changes due to both natural causes and to human intervention. ERS-1, 2 and Envisat data provided from the European Space Agency were analysed to produce a time-series analysis based on Persistent Scatterer techniques. The mass processing of the 81 satellite images led to the creation of more than 250 Interferograms. The broader area of interest consists primarily of agricultural lands, leading to limited Interferometric coherence, and therefore careful Interferogram filtering and phase unwrapping of the input stack was crucial for reliable velocity generation. Our results show a strong deformation signal in regions of significant lifelines, as the railway and road network. Moreover, the satellite imagery revealed two significantly deforming sites: Kalochori and Sindos. The broader Kalochori region, the locus of the industrial activity of the city of Thessaloniki, is located below sea level. Both sites are suffering from land subsidence for more than 50 years, with several marine invasions reported in the past. Interestingly enough the two datasets -that represent two decades- show a reversed deformation pattern: The period in-between 1993 to 2000 is characterized by subsidence up to 34 mm/y, whereas from 2002 to 2010 there is an uplifting trend (more than 20 mm/yr). This result is crosschecked with hydrogeological data; the interpretation depicts that at Kalochori and Sindos the human factor (i.e. over pumping) is the dominant driver of these surface displacements. Although this was an assumption of previous studies, here we present for the first time, systematic proof that the detected uplift of the second decade acts as a rebound of the ground-water level.

  17. On the Distribution of Ion Density Depletion Along Magnetic Field Lines as Deduced Using C-NOFS

    NASA Technical Reports Server (NTRS)

    Dao, E.; Kelley, M. C.; Hysell, D. L.; Retterer, J. M.; Su, Y.-J.; Pfaff, Robert F.; Roddy, P. A.; Ballenthin, J. O.

    2012-01-01

    To investigate ion density depletion along magnetic field lines, we compare in situ-measured ion density fluctuations as seen from C/NOFS and compare them to the field-line-integrated depletion of the whole bubble as inferred from electric field measurements. Results show that, within C/NOFS' range, local measurement of the normalized density depletion, (Delta)n/n(sub 0), near the apex may be far less than at other points on the same field line. We argue that the distribution of (Delta)n/n(sub 0) is a weighted distribution concentrated at latitudes of the Appleton anomalies and becomes more heavily weighted the closer the field-aligned bubble rises to the peak of the anomalies. A three-dimensional simulation of an ionospheric bubble verifies our arguments.

  18. Andean uplift and climate evolution in the southern Atacama Desert deduced from geomorphology and supergene alunite-group minerals

    NASA Astrophysics Data System (ADS)

    Bissig, Thomas; Riquelme, Rodrigo

    2010-11-01

    Supergene alunite group minerals from the Late Eocene El Salvador porphyry Cu district, the El Hueso epithermal gold deposit and the Coya porphyry Au prospect located in the Precordillera of Northern Chile (~ 26 to 26° 30´ Lat. S) have been dated by the 40Ar/ 39Ar method and analyzed for stable isotopes. These data support published geomorphologic and sedimentologic evidence suggesting that the Precordillera in the Southern Atacama Desert had been uplifted as early as the late Eocene and, thus, significantly prior to the Altiplano which attained its high elevation only in the late Miocene. The oldest supergene alunite from the Damiana exotic deposit at El Salvador was dated at 35.8 ± 1 Ma and yielded a δD (VSMOW) value of -74‰ which indicates elevations of the Precordillera near El Salvador of at least 3000 m in the Late Eocene. In contrast, Miocene supergene alunite from El Salvador, El Hueso, and Coya have less negative δD signatures reaching values as high as -23 to -25‰ at El Hueso and El Salvador between about 8.2 and 14 Ma. Late Miocene to Holocene supergene alunite, jarosite and natroalunite ages are restricted to El Hueso and Coya located near 4000 m above sea level in the Precordillera, roughly 1000 m higher than the present elevation of El Salvador. The δD values of samples younger than ~ 5 Ma vary between -57 and -97‰. The complex evolution of the δD signatures suggests that meteoric waters recorded in supergene alunite group minerals were variably affected by evaporation and provides evidence for climate desiccation and onset of hyper arid conditions in the Central Depression of the southern Atacama Desert after 15 Ma, which agrees well with published constraints from the Atacama Desert at 23-24° Lat. S. Our data also suggest that wetter climatic conditions than at present prevailed in the latest Miocene and early Pliocene in the Precordillera. The new and previously published age constraints for El Salvador indicate that supergene mineralization at the Damiana exotic Cu deposit occurred periodically over 23 Ma in a locally exceptionally stable paleohydrologic and geomorphologic configuration.

  19. Codon usage, genetic code and phylogeny of Dictyostelium discoideum mitochondrial DNA as deduced from a 7.3-kb region.

    PubMed

    Angata, K; Kuroe, K; Yanagisawa, K; Tanaka, Y

    1995-02-01

    We have sequenced a region (7,376-bp) of the mitochondrial (mt) DNA (54 kb) of the cellular slime mold, Dictyostelium discoideum. From the DNA and amino-acid sequence comparisons with known sequences, genes for ATPase subunit 9 (ATP9), cytochrome b (CYTB), NADH dehydrogenase subunits 1, 3 and 6 (ND1, ND3 and ND6), small subunit rRNA (SSU rRNA) and seven tRNAs (Arg, Asn, Cys, Lys, f-Met, Met and Pro) have been identified. The sequenced region of the mtDNA has a high average A + T-content (70.8%). The A + T-content of protein-genes (73.6%) is considerably higher than that of RNA genes (61.3%). Even with the strong AT-bias, the genetic code employed is most probably the universal one. All seven tRNAs are able to form typical clover leaf structures. The molecular phylogenetic trees of CYTB and SSU rRNA suggest that D. discoideum is closer to green plants than to animals and fungi. PMID:7736610

  20. Patterns of fusimotor activity during locomotion in the decerebrate cat deduced from recordings from hindlimb muscle spindles.

    PubMed

    Taylor, A; Durbaba, R; Ellaway, P H; Rawlinson, S

    2000-02-01

    1. Recordings have been made from multiple single muscle spindle afferents from medial gastrocnemius (MG) and tibialis anterior (TA) muscles of one hindlimb in decerebrate cats, together with ankle rotation and EMG signals, during treadmill locomotion. Whilst the other three limbs walked freely, the experimental limb was denervated except for the nerves to MG and TA and secured so that it could rotate only at the ankle joint, without any external load. Each afferent was characterised by succinylcholine testing with regard to its intrafusal fibre contacts. Active movements were recorded and then replayed through a servo mechanism to reproduce the muscle length changes passively after using a barbiturate to suppress gamma-motor firing. 2. The difference in secondary afferent firing obtained by subtracting the discharge during passive movements from that during active movements was taken to represent the profile of static fusimotor activity. This indicated an increase before the onset of movement followed by a strongly modulated discharge in parallel with muscle shortening during locomotion. The pattern of static firing matched the pattern of unloaded muscle shortening very closely in the case of TA and with some phase advance in the case of MG. The same effects were observed in primary afferents. 3. Primary afferents with bag1 (b1) contacts in addition showed higher firing frequencies during muscle lengthening in active than in passive movements. This indicated increased dynamic fusimotor firing during active locomotion. There was no evidence as to whether this fluctuated during the movement cycles. 4. When the mean active minus passive difference profile of firing in bag2-chain (b2c) type primary afferents was subtracted from that for b1b2c afferents, the difference was dominated by a peak centred on the moment of maximum lengthening velocity (v). 5. The component of the active minus passive difference firing due to b1 fibre contacts could be modelled by f(t) = av (where a is a constant) during lengthening and by f(t) = 0.2 av during shortening. The remainder of the difference signal matched the predictions of the static fusimotor signal derived from secondary afferents. 6. The findings are discussed in relation to the concept that the modulated static fusimotor pattern may represent a 'temporal template' of the expected movement, though the relationship of the results to locomotion in the intact animal will require further investigation. The analysis of the data indicates that the combined action of muscle length changes and static and dynamic fusimotor activity to determine primary afferent firing can be understood in terms of the interaction between the b1 and b2c impulse initiation sites.

  1. Towards Evidence-Based Policy for Canadian Education = Vers des politiques candiennes d'education fondees sur la recherche.

    ERIC Educational Resources Information Center

    De Broucker, Patrice, Ed.; Sweetman, Arthur, Ed.

    This book is a collection of 19 essays that broadly treat the use of evidence in informing educational policy and practice in Canada: (1) "Knowledge and Action in Educational Policy and Politics" (Benjamin Levin); (2) "Data, Data Everywhere (and We Don't Know What to Do): Using Data for Wise Decisions in Schools" (Lorna M. Earl); (3) "Do Education…

  2. Relationship between surface and subsurface structures of the northern Atlas foreland of Tunisia deduced from regional gravity analysis

    NASA Astrophysics Data System (ADS)

    Frifita, N.; Arfaoui, M. S.; Zargouni, F.

    2016-08-01

    Gravity data were analyzed in the northern Atlas of Tunisia in order to identify the deep structures of the region and their relationship to the geological outcrop. The analysis based on the Bouguer gravity maps related to upward continuation at 1, 2, 4, 6, 10 and 12 km. The lineaments obtained by the horizontal gradient method were interpreted as deep faults with two global directions NE-SW and NW-SE related to major tectonic corridors. These lineaments were confirmed by the automatic estimation of depth solutions using the Euler deconvolution technique. By separation between the gravity anomaly bodies in different levels, it shows that almost all of the lineaments are oriented in NE-SW and NW-SE directions. The NW-SE-trending lineaments are related to deep faults and the NE-SW-oriented lineaments define the global direction of the surface, and they are related to shallow structures. 2.5D gravity modeling was used to improve the results obtained by the Maxima and the Euler deconvolution techniques. The 2.5D model points out the variation of depths of the NE-SW-trending major faults. In this study, we demonstrate the relationship between the NE-SW and the NW-SE directions. These two major sets of faults have been determined by the statistical study of the lineaments. This study confirms some faults already recognized or supposed by the classical geological studies, and it also detects a new deep fault masked in the surface, and gives information about major fault depths and the relation between different structures.

  3. Convolution theorem for the three-dimensional entangled fractional Fourier transformation deduced from the tripartite entangled state representation

    NASA Astrophysics Data System (ADS)

    Liu, Shu-Guang; Fan, Hong-Yi

    2009-12-01

    We find that constructing the two mutually-conjugate tripartite entangled state representations naturally leads to the entangled Fourier transformation. We then derive the convolution theorem for the threedimensional entangled fractional Fourier transformation in the context of quantum mechanics.

  4. Calcium translocation mechanism in sarcoplasmic reticulum vesicles, deduced from location studies of protein-bound spin labels.

    PubMed Central

    Champeil, P; Rigaud, J L; Gary-Bobo, C M

    1980-01-01

    Sarcoplasmic reticulum vesicles were exposed to various thiol-directed spin labels, and the position of the label on the inner or outer vesicle surface was investigated as a function of the ATPase (adenosinetriphosphatase; ATP phosphohydrolase, EC 3.6.1.3) chemical state. Previous measurements of label accessibility to externally added ascorbate had been considered to suggest an external-internal transition of protein-bound labels, coupled with ion translocation [Tonomura, Y. & Morales, M.F. (1974) Proc. Natl. Acad. Sci. USA 71, 3687-3691]. We show that these ascorbate studies do not lead to convincing conclusions. We demonstrate, on the contrary, that transition ions (nickel and ferricyanide) can be used as selective line-broadening agents for the signals arising from external labels. No significant difference in nickel- or ferricyanide-label interaction can be attributed to a different orientation of the label in any of the enzyme chemical states tested. Our results therefore contradict the current interpretation of ascorbate quenching experiments in terms of calcium ATPase rotatory motion; rather they are consistent with ion transport models involving only limited conformational rearrangements of the pump. PMID:6446710

  5. Postmetamorphic unroofing history deduced from petrology, fluid inclusions, thermochronometry, and thermal modeling: An example from southwestern New England

    SciTech Connect

    Hames, W.E.; Tracy, R.J.; Bodnar, R.J. )

    1989-08-01

    Nonlinear unroofing rates from {approximately}10 to <1 mm/yr following high-pressure Acadian (Devonian) metamorphism have been documented in southwestern New England by using combined petrologic, fluid inclusion, thermochronometric, and thermal modeling techniques. Thermobarometry of pelitic schists from the Rowe-Hawley belt of western Connecticut indicates peak Acadian pressure-temperature conditions of 8.2 kbar and 575C. Densities of CO{sub 2}- and H{sub 2}O-rich fluid inclusions require nearly isothermal decompression followed by more isobaric cooling from these conditions. Comparison of this observed path to those generated by thermal models suggests that decompression was characterized by initial rapid upward en bloc velocity ({approximately}1 cm/yr) of brief duration, followed by much slower unroofing rates ({le}0.3 mm/yr). Published geochronologic ages in this region constrain the rapid uplift to the Middle Devonian, and uplift slowed dramatically by the end of the Devonian. This differential uplift has major implications for interpretation of Devonian igneous activity and sedimentation in southwestern New England.

  6. Evolution of tissue-specific keratins as deduced from novel cDNA sequences of the lungfish Protopterus aethiopicus.

    PubMed

    Schaffeld, Michael; Bremer, Miriam; Hunzinger, Christian; Markl, Jürgen

    2005-03-01

    Lungfishes are possibly the closest extant relatives of the land vertebrates (tetrapods). We report here the cDNA and predicted amino acid sequences of 13 different keratins (ten type I and three type II) of the lungfish Protopterus aethiopicus. These keratins include the orthologs of human K8 and K18. The lungfish keratins were also identified in tissue extracts using two-dimensional polyacrylamide gel electrophoresis, keratin blot binding assays and immunoblotting. The identified keratin spots were analyzed by peptide mass fingerprinting which assigned seven sequences (inclusively Protopterus K8 and K18) to their respective protein spot. The peptide mass fingerprints also revealed the fact that the major epidermal type I and type II keratins of this lungfish have not yet been sequenced. Nevertheless, phylogenetic trees constructed from multiple sequence alignments of keratins from lungfish and distantly related vertebrates such as lamprey, shark, trout, frog, and human reveal new insights into the evolution of K8 and K18, and unravel a variety of independent keratin radiation events. PMID:15819414

  7. Deducing composition and incident electron spectra from ground-based auroral optical measurements: A study of auroral red line processes

    SciTech Connect

    Meier, R.R. ); Strickland, D.J.; Hecht, J.H.; Christensen, A.B. )

    1989-10-01

    We conclude from a study of the production and loss of O({sup 1}{ital D}) in auroras that the traditional'' sources, direct electron impact excitation of atomic oxygen and dissociative recombination of molecular oxygen ions, can account for most of the O I 6300-A emission rate. In a specific application of the model to the comprehensive observation of an auroral event by Sharp et al. (1979), we show that there is no compelling need for the reaction N({sup 2}{ital D})+O{sub 2}{r arrow}NO+O({sup 1}{ital D}). We also present a study of the sensitivity of the red line emission rate to a wide variety of input conditions. {copyright} American Geophysical Union 1989

  8. Programme d'education de Maternelle--Francais Langue Premiere (Kindergarten Education Program--French as a First Language).

    ERIC Educational Resources Information Center

    Alberta Learning, Edmonton. Direction de l'education francaise.

    The materials in this document discuss the Alberta (Canada) public school curriculum for French native language instruction for 5-year olds in preschool, intended for implementation in September 2000. The first part outlines the rationale and organization of the curriculum model and its five guiding principles. The second part describes the seven…

  9. A new estimate of the chondrule cooling rate deduced from an analysis of compositional zoning of relict olivine

    SciTech Connect

    Miura, H.; Yamamoto, T.

    2014-03-01

    Compositional zoning in chondrule phenocrysts records the crystallization environments in the early solar nebula. We modeled the growth of olivine phenocrysts from a silicate melt and proposed a new fractional crystallization model that provides a relation between the zoning profile and the cooling rate. In our model, we took elemental partitioning at a growing solid-liquid interface and time-dependent solute diffusion in the liquid into consideration. We assumed a local equilibrium condition, namely, that the compositions at the interface are equal to the equilibrium ones at a given temperature. We carried out numerical simulations of the fractional crystallization in one-dimensional planar geometry. The simulations revealed that under a constant cooling rate the growth velocity increases exponentially with time and a linear zoning profile forms in the solid as a result. We derived analytic formulae of the zoning profile, which reproduced the numerical results for wide ranges of crystallization conditions. The formulae provide a useful tool to estimate the cooling rate from the compositional zoning. Applying the formulae to low-FeO relict olivine grains in type II porphyritic chondrules observed by Wasson and Rubin, we estimate the cooling rate to be ∼200-2000 K s{sup –1}, which is greater than that expected from furnace-based experiments by orders of magnitude. Appropriate solar nebula environments for such rapid cooling conditions are discussed.

  10. Deep crustal structure off Akita, eastern margin of the Japan Sea, deduced from ocean bottom seismographic measurements

    NASA Astrophysics Data System (ADS)

    Nishizawa, Azusa; Asada, Akira

    1999-06-01

    A seismic exploration was carried out to detect the heterogeneity of the seismic wavespeed structure associated with the plate convergence at the eastern margin of the Japan Sea. Two airgun-OBS (ocean bottom seismograph) profiles were shot off Akita, Japan, where a seismic gap seems to exist but the location of the plate boundary has not been confirmed. One of the profiles was 60 km long, trending NNE-SSW, named Line OBS-9, at the northeastern end of the Yamato Basin and the other was 170 km long, trending WNW-ESE, Line NT95-1, parallel to the direction of the supposed plate convergence. The crustal structure beneath Line OBS-9 consists of six layers. The uppermost layer is sediment. Three layers are identified beneath the top sedimentary layer and their P wavespeeds are estimated to be 3.3-3.4 km/s, 5.1-5.4 km/s and 5.8-6.3 km/s, which corresponds to the upper crust. Underneath these layers, a layer with P wavespeed ranges of 6.3-7.2 km/s comprises the middle and lower crust. The depth of Moho is inferred to be 19 km. These wavespeed values are comparable with those of the present Japanese island arc, while the thickness of the crust is one-half of that of the Japanese arc. The crustal model supports the scenario that the Yamato Basin is formed by extension of the island arc. The crustal model for Line NT95-1 shows a transition from the extended island arc structure beneath the Yamato Basin to a thicker crust similar to the Japanese arc. P wavespeed heterogeneity related to the plate boundary is not detected. However, a significant change in the structural model along the profile is found around the region where the largest change in the seafloor topography exists. In that region, the wavespeeds in the middle crust have lower values than those of the neighboring area and the Moho begins to deepen towards the Japanese island arc. From comparison with the relationship between P wavespeed structure and aftershock distribution of the 1993 Hokkaido-Nansei-Oki earthquake (southwest of Hokkaido, MJMA 7.8), the region may correspond to a possible fault position of the pending earthquake.

  11. Wintertime haze deterioration in Beijing by industrial pollution deduced from trace metal fingerprints and enhanced health risk by heavy metals.

    PubMed

    Lin, Yu-Chi; Hsu, Shih-Chieh; Chou, Charles C-K; Zhang, Renjian; Wu, Yunfei; Kao, Shuh-Ji; Luo, Li; Huang, Chao-Hao; Lin, Shuen-Hsin; Huang, Yi-Tang

    2016-01-01

    Airborne particulate matter (PM) was collected in Beijing between 24 February and 12 March 2014 to investigate chemical characteristics and potential industrial sources of aerosols along with health risk of haze events. Results showed secondary inorganic aerosol was the major contributor to PM2.5 during haze days. Utilizing specific elements, including Fe, La, Tl and As, as fingerprinting tracers, four emission sources, namely iron and steel manufacturing, petroleum refining, cement plant, and coal combustion were explicitly identified; their elevated contributions to PM during haze days were also estimated. The average cancer risk from exposure to inhalable PM toxic metals was 1.53 × 10(-4) on haze days, which is one order of magnitude higher than in other developed cities. These findings suggested heavy industries emit large amounts of not only primary PM but also precursor gas pollutants, leading to secondary aerosol formation and harm to human health during haze days.

  12. Amino acid sequence of rabbit kidney neutral endopeptidase 24.11 (enkephalinase) deduced from a complementary DNA.

    PubMed Central

    Devault, A; Lazure, C; Nault, C; Le Moual, H; Seidah, N G; Chrétien, M; Kahn, P; Powell, J; Mallet, J; Beaumont, A

    1987-01-01

    Neutral endopeptidase (EC 3.4.24.11) is a major constituent of kidney brush border membranes. It is also present in the brain where it has been shown to be involved in the inactivation of opioid peptides, methionine- and leucine-enkephalins. For this reason this enzyme is often called 'enkephalinase'. In order to characterize the primary structure of the enzyme, oligonucleotide probes were designed from partial amino acid sequences and used to isolate clones from kidney cDNA libraries. Sequencing of the cDNA inserts revealed the complete primary structure of the enzyme. Neutral endopeptidase consists of 750 amino acids. It contains a short N-terminal cytoplasmic domain (27 amino acids), a single membrane-spanning segment (23 amino acids) and an extracellular domain that comprises most of the protein mass. The comparison of the primary structure of neutral endopeptidase with that of thermolysin, a bacterial Zn-metallopeptidase, indicates that most of the amino acid residues involved in Zn coordination and catalytic activity in thermolysin are found within highly honmologous sequences in neutral endopeptidase. Images Fig. 1. Fig. 3. PMID:2440677

  13. Palaeoclimatic record in the loess-palaeosol sequence of the Strelitsa type section (Don glaciation area, Russia) deduced from rock magnetic and palynological data

    NASA Astrophysics Data System (ADS)

    Virina, Elena I.; Heller, Friedrich; Faustov, Stanislav S.; Bolikhovskaya, Nathalia S.; Krasnenkov, Robert V.; Gendler, Tatyana; Hailwood, Ernie A.; Hus, Jozeph

    2000-07-01

    Until now, palaeoclimatic reconstructions for the major stages in the development of the Quaternary loess-palaeosol sequence on the Russian Plain have been based on pedological, palynological and faunal (vertebrates and molluscs) analyses. In order to demonstrate the palaeoclimatic influence on the magnetic properties of this sequence, the magnetic susceptibility signature of the Strelitsa type section in the Upper Don basin is compared with a detailed landscape - climate reconstruction of loess and soil from palynological data. Large amplitude fluctuations of palaeoclimate and palaeoenvironment are reflected clearly in the lithology and in the rock magnetic properties, which usually are enhanced in wet and warm interglacial periods, but stay at low levels during cold glacial epochs. Palynological climate zonation, however, is sometimes in conflict with the pedologic-magnetic record. Strong climate fluctuations, as indicated by changing pollen assemblages, are not always paralleled by corresponding changes in lithology and/or rock magnetic properties. Alternatively, light coloured illuvial horizons with low magnetic signal sometimes appear to have formed during early stages of interglacials, and the top parts of some palaeosols apparently formed during glacial stages.

  14. Deducing the functional characteristics of the human selenoprotein SELK from the structural properties of its intrinsically disordered C-terminal domain.

    PubMed

    Polo, Andrea; Colonna, Giovanni; Guariniello, Stefano; Ciliberto, Gennaro; Costantini, Susan

    2016-03-01

    The intrinsically disordered proteins (IDPs) cannot be described by a single structural representation but, due to their high structural fluctuation, through conformational ensembles. Certainly, molecular dynamics (MD) simulations represent a useful tool to study their different conformations capturing the conformational distribution. Our group is focusing on the structural characterization of proteins belonging to the seleno-proteome due to their involvement in cancer. They present disordered domains central for their biological function, and, in particular, SELK is a single-pass transmembrane protein that resides in the endoplasmic reticulum membrane (ER) with a C-terminal domain exposed to the cytoplasm that is known to interact with different components of the endoplasmic reticulum associated to the protein degradation (ERAD) pathway. This protein is found to be up-expressed in hepatocellular carcinoma and in other cancers. In this work we performed a detailed analysis of the C-terminal domain sequence of SELK and discovered that it is characterized by many prolines, and four negatively and eleven positively charged residues, which are crucial for its biological activity. This region can be considered as a weak polyelectrolyte and, specifically, a polycation, with high disordered propensity and different phosphorylation sites dislocated along the sequence. Then, we modeled its three-dimensional structure by performing MD simulations in water at neutral pH to analyze the structural stability as well as to identify the presence of HUB residues that play a key structural role as evidenced by the residue-residue interaction network analysis. Through this approach, we demonstrate that the C-terminal domain of SELK (i) presents a poor content of regular secondary structure elements, (ii) is dynamically stabilized by a network of intra-molecular H-bonds and H-bonds with water molecules, (iii) is highly fluctuating and, therefore, can be described only through a conformational ensemble, where we evidenced a distribution of equilibrium conformers which continuously inter-change their conformations. Finally to verify the specific role played by the negative charges, we also performed MD simulations at acidic pH. Overall, all the obtained results evidenced that SELK has the dynamic structural features to be defined as a HUB protein able to interact with multiple members. Therefore, considering the possible role that this protein can have in cancer development and progression, it can represent a target for drug design studies. PMID:26735936

  15. Possible steps of complete disassembly of post-termination complex by yeast eEF3 deduced from inhibition by translocation inhibitors.

    PubMed

    Kurata, Shinya; Shen, Ben; Liu, Jun O; Takeuchi, Nono; Kaji, Akira; Kaji, Hideko

    2013-01-01

    Ribosomes, after one round of translation, must be recycled so that the next round of translation can occur. Complete disassembly of post-termination ribosomal complex (PoTC) in yeast for the recycling consists of three reactions: release of tRNA, release of mRNA and splitting of ribosomes, catalyzed by eukaryotic elongation factor 3 (eEF3) and ATP. Here, we show that translocation inhibitors cycloheximide and lactimidomycin inhibited all three reactions. Cycloheximide is a non-competitive inhibitor of both eEF3 and ATP. The inhibition was observed regardless of the way PoTC was prepared with either release factors or puromycin. Paromomycin not only inhibited all three reactions but also re-associated yeast ribosomal subunits. On the other hand, sordarin or fusidic acid, when applied together with eEF2/GTP, specifically inhibited ribosome splitting without blocking of tRNA/mRNA release. From these inhibitor studies, we propose that, in accordance with eEF3's known function in elongation, the release of tRNA via exit site occurs first, then mRNA is released, followed by the splitting of ribosomes during the disassembly of post-termination complexes catalyzed by eEF3 and ATP.

  16. The effect of salinization and freshening events in coastal aquifers on nutrient characteristics as deduced from column experiments under aerobic and anaerobic conditions

    NASA Astrophysics Data System (ADS)

    Russak, A.; Sivan, O.; Herut, B.; Lazar, B.; Yechieli, Y.

    2015-10-01

    This study experimentally quantified the effect of seawater intrusion (salinization) and freshening events in coastal aquifers on nutrient (N, P and DSi) dynamics across the fresh-saline groundwater interface. Laboratory column experiments were conducted under aerobic and anaerobic conditions in order to simulate the processes occurring in the fresh-saline interface. They were performed with aquifer sediments, simulating the natural conditions during alterations of natural fresh groundwater to seawater and vice versa. The salinization and freshening experiments showed that NH4+ and PO43- and DSi were affected mainly by ion exchange processes while microbial activity controlled the nitrogen species NO3- and NO2-. Due to the cation exchange, salinization generated enrichment (above the expected conservative behavior) of NH4+, up to 80 μmol L-1 (an order of magnitude higher than in seawater or fresh groundwater). Under anaerobic conditions NO3- was removed by denitrification, as demonstrated by the decrease in NO3- concentrations, the increase in NO2- concentrations, and the increase in δ15N by 15-25‰. Clear evidence was shown for anion exchange of PO43-, which competes with HCO3- and boron on adsorption sites. DSi seems to take part in the exchange process, similar to PO43-.

  17. Oceanic density fronts steering bottom-current induced sedimentation deduced from a 50 ka contourite-drift record and numerical modeling (off NW Spain)

    NASA Astrophysics Data System (ADS)

    Hanebuth, Till J. J.; Zhang, Wenyan; Hofmann, Antonia L.; Löwemark, Ludvig A.; Schwenk, Tilmann

    2015-03-01

    How the various bottom-near hydrographic and sedimentary processes control the formation of contourite drifts, i.e. of bottom-current related confined deep-sea depocenters, usually remains widely speculative. This study uses a transect of six sediment cores and a sediment echosounder profile across a whole contourite system off NW Spain to address the sediment dynamics responsible for the depositional pattern. This "mounded patch"-type contourite drift (18 km long, 20 km wide) with a 150-m deep channel (moat) has formed around an 800-m high structural obstacle. Deposition on the contourite drift in the past was characterized by alternating calm and high-energy bottom-flow conditions. Calm conditions (Last Glacial period: 27-17 cal ka BP; late Holocene times: <4 cal ka BP) led to slightly current-influenced deposition of fine-grained sediments (10 μm) in the entire basin. This regime was interrupted by periods of short-lasting waxing-and-waning high-energy conditions (D/O events during Marine Isotope Stage 3; the Deglacial/early Holocene time interval at 17-4 cal ka BP), resulting in the deposition of coarse sediments (70 μm). Process-based numerical modeling demonstrates that pulse-like oceanic density fronts traveling within the transition zone of two water masses (Labrador Sea Water, Mediterranean Outflow Water) provide a powerful mechanism for contouritic deposition, rather than the core of a water mass itself. These gravity-driven density fronts lead to local re-suspension of sands stored inside the drift's moat and to subsequent upward transport towards the drift's crest. Here, the oceanic density fronts produce additional km-scale eddies. These migrating eddies provide an efficient mechanism for further widespread sediment re-distribution. In comparison with paleoceanographic reconstructions, a downward migration or expansion of the Mediterranean Outflow Water by about 300 m led most probably to such temporary contouritic sand deposition. We finally propose a conceptual model to explain how seafloor obstacles redirect and perturbate bottom currents. This model proposes not only a sharp contact between two water masses but also the transition zone between those as an important high-energy regime, offering oceanic density fronts a travel medium. These fronts are strong enough to distribute fine sands across highly pronounced seabed topography. On the respective time scale, the moat itself seems to act as the main source for those sands, making a remote source and a long-distance sediment transport unnecessary.

  18. Oceanic Density Fronts Steering Bottom-Current Induced Sedimentation Deduced from a 50 ka Contourite-Drift Record and Numerical Modeling (off NW Spain)

    NASA Astrophysics Data System (ADS)

    Hanebuth, T. J. J.; Zhang, W.; Hofmann, A. L.; Lowemark, L. A.; Schwenk, T.

    2015-12-01

    How bottom-near hydrographic and sedimentary processes control the formation of bottom-current related confined deep-sea depocenters remains widely speculative. The geological approach of this study uses a transect of sediment cores and sediment echosounder profiles across a whole contourite system off NW Spain. This "mounded patch"-type contourite drift (18 km long, 20 km wide) with a 150-m deep moat has formed around an 800-m high structural obstacle. Past deposition was characterized by alternating calm and high-energy bottom-flow conditions. Calm conditions (Last Glacial period: 27-17 cal ka BP; late Holocene times: < 4 cal ka BP) led to slightly current-influenced deposition of fine-grained sediments (10 µm) over the entire basin. In contrast, waxing-and-waning high-energy conditions (D/O events during Marine Isotope Stage 3; the Deglacial/early Holocene time interval at 17-4 cal ka BP) resulted in coarse grained (70 µm) deposition. Process-based numerical modelling demonstrates that pulse-like oceanic density fronts travelling within the transition zone of two water masses (Labrador Sea Water, Mediterranean Outflow Water) provide a powerful mechanism for contouritic deposition, rather than the core of a water mass itself. These gravity-driven density fronts lead to local re-suspension of sand from the moat and to subsequent upward transport over the crest. Here, the oceanic density fronts produce additional km-scale eddies. These migrating eddies provide an efficient mechanism for further widespread sediment re-distribution. In comparison with paleoceanographic reconstructions, a downward migration or expansion of the Mediterranean Outflow Water by about 300 m led most probably to such temporary contouritic sand deposition. We finally propose a conceptual model to explain how seafloor obstacles redirect and perturbate bottom currents. This model proposes water mass transition zone as an important high-energy medium, for oceanic density fronts to travel. On the respective time scale, the moat itself seems to act as the main source for those sands, making a remote source and a long-distance sediment transport unnecessary.

  19. Transfer of Learning: Planning Effective Workplace Education Programs = Transfert d'apprentissage: La Planification de programmes d'education efficaces en milieu de travail.

    ERIC Educational Resources Information Center

    Taylor, Maurice

    Given the centrality of the topic of transfer of learning to so many areas of workplace education, this discussion paper (in both English and French versions) draws together research results and practical techniques to help practitioners in the field. Part 1 defines transfer of learning. Part 2 describes factors that influence the transfer of…

  20. Marked longevity of human lung parenchymal elastic fibers deduced from prevalence of D-aspartate and nuclear weapons-related radiocarbon

    SciTech Connect

    Shapiro, S.D.; Endicott, S.K.; Province, M.A.; Pierce, J.A.; Campbell, E.J. )

    1991-05-01

    Normal structure and function of the lung parenchyma depend upon elastic fibers. Amorphous elastin is biochemically stable in vitro, and may provide a metabolically stable structural framework for the lung parenchyma. To test the metabolic stability of elastin in the normal human lung parenchyma, we have (a) estimated the time elapsed since the synthesis of the protein through measurement of aspartic acid racemization and (b) modeled the elastin turnover through measurement of the prevalence of nuclear weapons-related {sup 14}C. Elastin purified by a new technique from normal lung parenchyma was hydrolyzed; then the prevalences of D-aspartate and {sup 14}C were measured by gas chromatography and accelerator-mass spectrometry, respectively. D-aspartate increased linearly with age; Kasp (1.76 x 10{sup {minus} 3} yr{sup {minus} 1}) was similar to that previously found for extraordinarily stable human tissues, indicating that the age of lung parenchymal elastin corresponded with the age of the subject. Radiocarbon prevalence data also were consistent with extraordinary metabolic stability of elastin; the calculated mean carbon residence time in elastin was 74 yr (95% confidence limits, 40-174 yr). These results indicate that airspace enlargement characteristic of 'aging lung' is not associated with appreciable new synthesis of lung parenchymal elastin. The present study provides the first tissue-specific evaluation of turnover of an extracellular matrix component in humans and underscores the potential importance of elastin for maintenance of normal lung structure. Most importantly, the present work provides a foundation for strategies to directly evaluate extracellular matrix injury and repair in diseases of lung (especially pulmonary emphysema), vascular tissue, and skin.

  1. In vitro mutagenesis studies at the arginine residues of adenylate kinase. A revised binding site for AMP in the X-ray-deduced model.

    PubMed

    Kim, H J; Nishikawa, S; Tokutomi, Y; Takenaka, H; Hamada, M; Kuby, S A; Uesugi, S

    1990-02-01

    Although X-ray crystallographic and NMR studies have been made on the adenylate kinases, the substrate-binding sites are not unequivocally established. In an attempt to shed light on the binding sites for MgATP2- and for AMP2- in human cytosolic adenylate kinase (EC 2.7.4.3, hAK1), we have investigated the enzymic effects of replacement of the arginine residues (R44, R132, R138, and R149), which had been assumed by Pai et al. [Pai, E. F., Sachsenheimer, W., Schirmer, R. H., & Schulz, G. E. (1977) J. Mol. Biol. 114, 37-45] to interact with the phosphoryl groups of AMP2- and MgATP2-. With use of the site-directed mutagenesis method, point mutations were made in the artificial gene for hAK1 [Kim, H. J., Nishikawa, S., Tanaka, T., Uesugi, S., Takenaka, H., Hamada, M., & Kuby, S. A. (1989) Protein Eng. 2, 379-386] to replace these arginine residues with alanyl residues and yield the mutants R44A hAK1, R132A hAK1, R138A hAK1, and R149A hAK1. The resulting large increases in the Km,app values for AMP2- of the mutant enzymes, the relatively small increases in the Km,app values for MgATP2-, and the fact that the R132A, R138A, and R149A mutant enzymes proved to be very poor catalysts are consistent with the idea that the assigned substrate binding sites of Pai et al. (1977) have been reversed and that their ATP-binding site may be assigned as the AMP site.

  2. Aging, Maturation and Growth of Sauropodomorph Dinosaurs as Deduced from Growth Curves Using Long Bone Histological Data: An Assessment of Methodological Constraints and Solutions

    PubMed Central

    Griebeler, Eva Maria; Klein, Nicole; Sander, P. Martin

    2013-01-01

    Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates from the growth record preserved in long bones of six sauropod dinosaur individuals (one indeterminate mamenchisaurid, two Apatosaurus sp., two indeterminate diplodocids, and one Camarasaurus sp.) and one basal sauropodomorph dinosaur individual (Plateosaurus engelhardti). Using these estimates, we establish allometries between body mass and each of these traits and compare these to extant taxa. Growth models considered for each dinosaur individual were the von Bertalanffy model, the Gompertz model, and the logistic model (LGM), all of which have inherently fixed inflection points, and the Chapman-Richards model in which the point is not fixed. We use the arithmetic mean of the age at the inflection point and of the age at which 90% of asymptotic mass is reached to assess respectively the age at sexual maturity or the age at onset of reproduction, because unambiguous indicators of maturity in Sauropodomorpha are lacking. According to an AIC-based model selection process, the LGM was the best model for our sauropodomorph sample. Allometries established are consistent with literature data on other Sauropodomorpha. All Sauropodomorpha reached full size within a time span similar to scaled-up modern mammalian megaherbivores and had similar maximum growth rates to scaled-up modern megaherbivores and ratites, but growth rates of Sauropodomorpha were lower than of an average mammal. Sauropodomorph ages at death probably were lower than that of average scaled-up ratites and megaherbivores. Sauropodomorpha were older at maturation than scaled-up ratites and average mammals, but younger than scaled-up megaherbivores. PMID:23840575

  3. Origin of metazoan adhesion molecules and adhesion receptors as deduced from cDNA analyses in the marine sponge Geodia cydonium: a review.

    PubMed

    Müller, W E

    1997-09-01

    The phylogenetic relationships of the kingdom Animalia (Metazoa) have long been questioned. Whether the lowest eukaryotic multicellular organisms, the metazoan phylum Porifera (sponges), independently evolved multicellularity from a separate protist lineage (polyphyly of animals) or whether they were derived from the same protist group as the other animal phyla (monophyly) remains unclear. Analyses of the genes that are typical for multicellularity, e.g. those coding for adhesion molecules (galectin) and adhesion receptors (receptor tyrosine kinase, integrin receptor, receptors featuring scavenger receptor cysteine-rich domains) or elements involved in signal transduction pathways (G-proteins, Ser/Thr protein kinases), especially from the marine sponge Geodia cydonium, indicate that all animals, including sponges, are of monophyletic origin. PMID:9232818

  4. Temporal evolution of surface rupture deduced from coseismic multi-mode secondary fractures: Insights from the October 8, 2005 (Mw 7.6) Kashmir earthquake, NW Himalaya

    NASA Astrophysics Data System (ADS)

    Sayab, Mohammad; Khan, Muhammad Asif

    2010-10-01

    Detailed rupture-fracture analyses of some of the well-studied earthquakes have revealed that the geometrical arrangement of secondary faults and fractures can be used as a geological tool to understand the temporal evolution of slip produced during the mainshock. The October 8, 2005 Mw 7.6 Kashmir earthquake, NW Himalaya, surface rupture provides an opportunity to study a complex network of secondary fractures developed on the hanging wall of the fault scarp. The main fault scarp is clearly thrust-type, rupture length is ~ 75 ± 5 km and the overall trend of the rupture is NW-SE. We present the results of our detailed structural mapping of secondary faults and fractures at 1:100 scale, on the hanging wall of the southern end of the rupture in the vicinity of the Sar Pain. Secondary ruptures can be broadly classified as two main types, 1) normal faults and, (2) right-lateral strike-slip 'Riedel' fractures. The secondary normal faults are NW-SE striking, with a maximum 3.3 meter vertical displacement and 2.5 meter horizontal displacement. Estimated total horizontal extension across the secondary normal faults is 3.1-3.5%. We propose that the bending-moment and coseismic stress relaxation can explain the formation of secondary normal faults on the hanging wall of the thrust fault. The strike-slip 'Riedel' fractures form distinct sets of tension (T) and shear fractures (R', R, Y) with right-lateral displacement. Field observations revealed that the 'Riedel' fractures (T) cut the secondary normal faults. In addition, there is kinematic incompatibility and magnitude mismatch between the secondary normal faults and strike-slip 'Riedel' fractures. The cross-cutting relationship, geometric and magnitude incoherence implies a temporal evolution of slip from dip- to strike-slip during the mainshock faulting. The interpretation is consistent with the thrust fault plane solution with minor right-lateral strike-slip component.

  5. Tectonothermal history in the Mattawa area, Ontario, Canada, deduced from paleomagnetism and Ar-40/Ar-39 dating of a Grenville dike

    NASA Astrophysics Data System (ADS)

    Hyodo, Hironobu; York, Derek; Dunlop, David J.

    1993-10-01

    The paleomagnetic ambient has been determined from samples at various distances from a Grenville diabase dike cutting late Protozoic tonalitic gneiss near Mattawa in the Grenville Province, Canada. Using the Ar-40/Ar-39 technique, the intrusion age of the dike is estimated to be 570 +/- 3 Ma from a 0.5-mm-diameter chilled margin chip. The paleo-ambient temperature of the country rock at the time of intrusion, 184 +/- 40 C was calculated from Jaeger's (1964) one-dimensional heat conduction model. The burial depth of the presently exposed rocks is estimated to be 6.5 +/- 1.7 km, assuming a surface temperature of 15 C and a geothermal gradient of 26 C/km. This depth at 570 Ma is discordant with the presence of Ordovician shallow-water (less than 100 m) limestones about 200 km distant, suggesting that differential uplift may have occurred between the two areas.

  6. Deduced amino acid sequence, gene structure and chromosomal location of a novel human class Mu glutathione S-transferase, GSTM4.

    PubMed Central

    Zhong, S; Spurr, N K; Hayes, J D; Wolf, C R

    1993-01-01

    The Mu-Class glutathione S-transferases (GSTs) are subject to marked inter-individual variation in man, owing to the fact that 40-50% of the population fail to express M1 subunits. Mu-Class GST from two lymphoblastoid cell lines (expressing M1 subunits and the other 'nulled' for M1) have been studied. Both cell lines were found to express a Mu-Class GST that has not been described previously. The cDNA encoding this novel transferase, designated 'GSTM4' has been isolated and the enzyme shown to be comprised of 218 amino acids (including the initiator methionine residue) with an M(r) of approx. 25.5 kDa. Molecular cloning demonstrated that the lymphoblastoid cell line which expressed GSTM1 possessed the b allelic variant (i.e. that with an asparagine residue at position 173). The genes for GSTM4 and GSTM1b have been cloned and found to contain seven introns and eight exons. The coding region of the GSTM4 gene, including the seven introns, encompasses 5.0 kb, whereas the same region of GSTM1b is 5.5 kb; the difference in the size of the two genes is due to the length of intron 7. DNA sequencing allowed a GSTM4-gene-specific oligo-primer to be designed which has been utilized in a PCR-based assay to determine that the GSTM4 gene is located on chromosome 1. Images Figure 1 Figure 3 Figure 6 PMID:8471052

  7. The properties and environment of primitive solar nebulae as deduced from observations of solar-type pre-main sequence stars

    NASA Technical Reports Server (NTRS)

    Strom, Stephen E.; Edwards, Suzan; Strom, Karen M.

    1991-01-01

    The following topics were discussed: (1) current observation evidence for the presence of circumstellar disks associated with solar type pre-main sequence (PMS) stars; (2) the properties of such disks; and (3) the disk environment.

  8. Amino acid sequence homology between N- and C-terminal halves of a carbonic anhydrase in Porphyridium purpureum, as deduced from the cloned cDNA.

    PubMed

    Mitsuhashi, S; Miyachi, S

    1996-11-01

    Carbonic anhydrase (CA) from Porphyridium purpureum, a unicellular red alga, was purified >209-fold to a specific activity of 1,147 units/mg protein. cDNA clones for this CA were isolated. The longest clone, comprising 1,960 base pairs, contained an open reading frame which encoded a 571-amino acid polypeptide with a calculated molecular mass of 62,094 Da. The N- and C-terminal halves of the putative mature Porphyridium CA have amino acid sequence homology to each other (>70%) and to other prokaryotic-type CAs. Both regions contain, at equivalent positions, one set of three possible zinc-liganding amino acid residues conserved among prokaryotic-type CAs. CA purified from Porphyridium contained two atoms of zinc per molecule. We propose that the Porphyridium CA has evolved by duplication of an ancestral CA gene followed by the fusion of the duplicated CA gene. The CA truncated into the putative mature form was overexpressed in Escherichia coli, and the expressed protein was active. Clones expressing separately the N- and C-terminal halves of the CA were constructed. CA activity was present in extracts of E. coli cells expressing the N-terminal half, while no detectable activity was found in cells expressing the C-terminal half.

  9. Slip distribution of the 1952 Tokachi-Oki earthquake (M 8.1) along the Kuril Trench deduced from tsunami waveform inversion

    USGS Publications Warehouse

    Hirata, K.; Geist, E.; Satake, K.; Tanioka, Y.; Yamaki, S.

    2003-01-01

    We inverted 13 tsunami waveforms recorded in Japan to estimate the slip distribution of the 1952 Tokachi-Oki earthquake (M 8.1), which occurred southeast off Hokkaido along the southern Kuril subduction zone. The previously estimated source area determined from tsunami travel times [Hatori, 1973] did not coincide with the observed aftershock distribution. Our results show that a large amount of slip occurred in the aftershock area east of Hatori's tsunami source area, suggesting that a portion of the interplate thrust near the trench was ruptured by the main shock. We also found more than 5 m of slip along the deeper part of the seismogenic interface, just below the central part of Hatori's tsunami source area. This region, which also has the largest stress drop during the main shock, had few aftershocks. Large tsunami heights on the eastern Hokkaido coast are better explained by the heterogeneous slip model than previous uniform-slip fault models. The total seismic moment is estimated to be 1.87 ?? 1021 N m, giving a moment magnitude of Mw = 8.1. The revised tsunami source area is estimated to be 25.2 ?? 103 km2, ???3 times larger than the previous tsunami source area. Out of four large earthquakes with M ??? 7 that subsequently occurred in and around the rupture area of the 1952 event, three were at the edges of regions with relatively small amount of slip. We also found that a subducted seamount near the edge of the rupture area possibly impeded slip along the plate interface.

  10. Recent crustal deformation of İzmir, Western Anatolia and surrounding regions as deduced from repeated GPS measurements and strain field

    NASA Astrophysics Data System (ADS)

    Aktuğ, Bahadır; Kılıçoğlu, Ali

    2006-07-01

    To investigate contemporary neotectonic deformation in İzmir, Western Anatolia and in its neighborhood, a relatively dense Global Positioning System (GPS) monitoring network was established in 2001. Combination of three spatially dense GPS campaigns in 2001, 2003 and 2004 with temporally dense campaigns between 1992 and 2004 resulted in a combined velocity field representing active deformation rate in the region. We computed horizontal and vertical velocity fields with respect to Earth-centered, Earth-fixed ITRF2000, to Eurasia and to Anatolia as well. The rates of principal and shear strains along with rigid-body rotation rates were derived from velocity field. Results show east-west shortening between Karaburun Peninsula and northern part of İzmir Bay together with the extension of İzmir Bay in accordance with general extension regime of Western Anatolia and Eastern Agea. East-west shortening and north-south extension of Karaburun Peninsula are closely related to right-lateral faulting and a clockwise rotation. There exists a block in the middle of the peninsula with a differential motion at a rate of 3-5 ± 1 mm/year and 5-6 ± 1 mm/year to the east and south, respectively. As is in Western Anatolia, north-south extension is dominant in almost all parts of the region despite the fact that they exhibit significantly higher rates in the middle of the peninsula. Extensional rates along Tuzla Fault lying nearly perpendicular to İzmir Bay and in its west are maximum in the region with an extension rate of 300-500 ± 80-100 nanostrain/year and confirm its active state. Extensional rates in other parts of the region are at level of 50-150 nanostrain/year as expected in the other parts of Western Anatolia.

  11. New light on a dark subject: On the use of fluorescence data to deduce redox states of natural organic matter (NOM)

    USGS Publications Warehouse

    MacAlady, Donald L.; Walton-Day, Katherine

    2009-01-01

    This paper reports the use of excitation-emission matrix fluorescence spectroscopy (EEMS), parallel factor statistical analysis (PARAFAC), and oxidation-reduction experiments to examine the effect of redox conditions on PARAFAC model results for aqueous samples rich in natural organic matter. Fifty-four aqueous samples from 11 different geographic locations and two plant extracts were analyzed untreated and after chemical treatments or irradiation were used in attempts to change the redox status of the natural organic matter. The EEMS spectra were generated and modeled using a PARAFAC package developed by Cory and McKnight (2005). The PARAFAC model output was examined for consistency with previously reported relations and with changes expected to occur upon experimental oxidation and reduction of aqueous samples. Results indicate the implied fraction of total sample fluorescence attributed to quinone-like moieties was consistent (0.64 to 0.78) and greater than that observed by Cory and McKnight (2005). The fraction of the quinone-like moieties that was reduced (the reducing index, RI) showed relatively little variation (0.46 to 0.71) despite attempts to alter the redox status of the natural organic matter. The RI changed little after reducing samples using zinc metal, oxidizing at high pH with air, or irradiating with a Xenon lamp. Our results, however, are consistent with the correlations between the fluorescence indices (FI) of samples and the ratio of PARAFAC fitting parameters suggested by Cory and McKnight (2005), though we used samples with a much narrower range of FI values.

  12. Role of pyroclast recycling on style of small basaltic explosions at Stromboli Volcano, Italy, deduced from real-time collected ash samples.

    NASA Astrophysics Data System (ADS)

    Miwa, T.; Kawaguchi, R.; Nishimura, T.; Aoyama, H.; Yamada, T.; Fujita, E.

    2015-12-01

    Understandings of controlling mechanism on the style of volcanic explosion is one of the most important subject not only for volcanology but also for hazard mitigation. Vesiculation, outgassing and crystallization of magma, and interaction with external water have been considered as essential factors for the controlling mechanism (e.g., Houghton and Gonnerman, 2005). In contrast, recent studies suggested that vigorous recyclings of pyroclast into the vent occur at basaltic volcanoes with repeating small explosions (D'Oriano et al., 2014). The recycling of pyroclast that fills the shallow conduit can affect explosion dynamics such as shape and ejection speed of jet cloud (e.g., Ohba et al., 2002). This study examined component, texture and chemical composition of ash samples collected during normal activity at Stromboli to discuss a controlling mechanism of small explosion styles in basaltic volcano. During studied term (14:26-18:29, May 21th, 2014), ash-rich explosion occurred in NE crater, and ash-poor explosion occurred in the central and SW craters. We performed real-time collection of falling ash every 4-18 minutes. The real-time collection permits direct comparison of the ash samples with explosion activity. We classify the ash particles into Juvenile (glassy particles having similar composition with HP magma), Recycled (similar texture with reheated basaltic ash; D'Oriano et al., 2013), Altered, and Crystal particles. Bulk component of recycled particle calculated from componentry variations with grain size and grain size distribution shows that the volume fraction of recycled particles increases with ash falling rate at sampling site. The ash falling rate at sampling site increased after the occurrence of ash rich explosions at NE crater. Our ash observation indicates that burial of eruptive vent by recycled pyroclasts relates with occurrence of ash rich explosion at NE crater. Therefore, we suggest that combination of the amount of gas supplied from a deeper conduit and thickness of the buried sediment in the vent controls the style of small basaltic explosion in Stromboli (Burton et al., 2007; Patrick et al., 2007; Quane et al., 2009). Depositional structure of the vent determined by the pyroclast recycling and history of the explosions are important for understanding the explosion styles.

  13. Energetic Particle Propagation in the Inner Heliosphere as Deduced from Low Frequency (less than 100 kHz) Observations of Type III Radio Bursts

    NASA Technical Reports Server (NTRS)

    Cane, H. V.; Erickson, W. C.

    2003-01-01

    Solar energetic particle (SEP) events are well-associated with solar flares. It is observed that the delay between the time of the flare and the first-arriving particles at a spacecraft increases with increasing difference between the flare longitude and the footpoint of the field line on which the spacecraft is located. This difference we call the "connection angle" and can be as large as approximately 120 deg. Recently it has been found that all SEP events are preceded by type III radio bursts. These bursts are plasma emission caused by the propagation of 2-50 keV flare electrons through the solar corona and into the solar wind. The drift of these type III radio bursts to lower and lower frequencies enables the propagation of the flare electrons to be traced from the Sun to about 1 AU. We have made an extensive analysis of the type III bursts associated with greater than 20 MeV proton events and find that, in most cases, the radio emission extends to the local plasma frequency when the energetic particles arrive within a few hours of the flare. We conclude that this emission at the lowest possible frequency is generated close to the spacecraft. We then use the time from when the burst started at the Sun to when it reached the local plasma frequency to infer the time it took the radio producing electrons to travel to the spacecraft. We find that these delay times are organized by the connection angle and correlate with the proton delay times. We also find that the differences between the radio delays at Wind and Ulysses are matched by differences in the relative arrival times of the energetic particles at the two spacecraft. The consistent timing between the relative arrival times of energetic electrons and protons and the start of the lowest frequency radio emissions suggests that the first arriving particles of both species are accelerated as part of the flare process and that they propagate to the spacecraft along trajectories similar to those of the lower energy flare electrons. To be detected by observers at locations distant from the nominal field lines originating in the flaring regions the particles must undergo lateral transport. The continuity of the radio bursts suggests that the cross-field transport may occur in the interplanetary medium.

  14. Global average concentration and trend for hydroxyl radicals deduced from ALE/GAGE trichloroethane (methyl chloroform) data for 1978-1990

    NASA Technical Reports Server (NTRS)

    Prinn, R.; Cunnold, D.; Simmonds, P.; Alyea, F.; Boldi, R.; Crawford, A.; Fraser, P.; Gutzler, D.; Hartley, D.; Rosen, R.

    1992-01-01

    An optimal estimation inversion scheme is utilized with atmospheric data and emission estimates to determined the globally averaged CH3CCl3 tropospheric lifetime and OH concentration. The data are taken from atmospheric measurements from surface stations of 1,1,1-trichloroethane and show an annual increase of 4.4 +/- 0.2 percent. Industrial emission estimates and a small oceanic loss rate are included, and the OH concentration for the same period (1978-1990) are incorporated at 1.0 +/- 0.8 percent/yr. The positive OH trend is consistent with theories regarding OH and ozone trends with respect to land use and global warming. Attention is given to the effects of the ENSO on the CH3CCl3 data and the assumption of continuing current industrial anthropogenic emissions. A novel tropical atmospheric tracer-transport mechanism is noted with respect to the CH3CCl3 data.

  15. Binding stoichiometry of the gene 32 protein of phage T4 in the complex with single stranded DNA deduced from boundary sedimentation.

    PubMed

    Scheerhagen, M A; Vlaanderen, C A; Blok, J; van Grondelle, R

    1986-04-01

    Short 145 base DNA fragments in complex with the helix destabilizing protein of bacteriophage T4, GP32, have been studied with boundary sedimentation. The sedimentation coefficient was determined as a function of concentration, protein-nucleic acid ratio, temperature and salt concentration. It can be concluded that the measured values reflect the properties of the saturated DNA-GP32 complex. A combination of the earlier obtained translational diffusion coefficient of the complex with the sedimentation coefficient yields its anhydrous molecular weight (Mw = 5.4.10(5) D), which corresponds to a size of the binding site of 10 nucleotides per protein. This procedure is not sensitive to the presence of non-binding protein molecules and to the assumed protein concentration, and therefore, it seems more reliable than a determination from titration experiments. Similar sedimentation measurements were performed with tRNA-complexes containing 76 nucleotides. The translational diffusion coefficient can be calculated from the measured rotational diffusion coefficient and assuming the same hydrodynamic diameter for this complex as obtained for the 145 b DNA complex. The molecular weight derived from the data then also leads to a binding site size of about 10 nucleotides. This suggests that also the short tRNA-complex forms an open, strongly solvated structure, as was proposed for the 145 b DNA-GP32 complex.

  16. Variability in aerosol optical and physical characteristics over the Bay of Bengal and the Arabian Sea deduced from Ångström exponents

    NASA Astrophysics Data System (ADS)

    Kedia, Sumita; Ramachandran, S.

    2009-07-01

    Spectral distribution of aerosol optical depths (AODs) measured in the 0.4-0.875 μm wavelength region using a Sun photometer over Bay of Bengal and Arabian Sea during the 2006 premonsoon season are analyzed to obtain more interesting information on the physical and optical characteristics of aerosols. Examination of spectral AODs measured over the Bay of Bengal and the Arabian Sea by deriving the Ångström exponent (α) for the entire spectral range (0.4-0.875 μm), α for different spectral ranges, and second derivative (α') showed that the aerosol size distribution is of mixed type or bimodal with contributions from fine and coarse modes. The α-AOD relationships in short (0.4-0.5 μm), long (0.65-0.9 μm), and full (0.4-0.9 μm) spectral ranges determined for various aerosol models (urban, maritime clean, maritime polluted, and desert) suggest that the α-AOD relationship can vary depending on whether the size distribution is unimodal, mixed type, or bimodal, similar to the results obtained for measured AOD spectra. Significant curvature in the ln AOD versus ln λ is observed which causes spectral variation in α derived in different spectral ranges. Over the Bay of Bengal for 76% of AOD spectra, α2 - α1 is >1, suggesting the presence of fine-mode aerosols from a wide variety of fine-mode fractions or a mixture of modes, while over the Arabian Sea, α2 - α1 is <1 for 84% of AOD spectra, clearly indicating the dominance of coarse-mode aerosols. These characteristics can be used in modeling the regional and seasonal aerosol radiative effects and in remote sensing.

  17. Primitive Extracellular Lipid Components on the Surface of the Charophytic Alga Klebsormidium flaccidum and Their Possible Biosynthetic Pathways as Deduced from the Genome Sequence

    PubMed Central

    Kondo, Satoshi; Hori, Koichi; Sasaki-Sekimoto, Yuko; Kobayashi, Atsuko; Kato, Tsubasa; Yuno-Ohta, Naoko; Nobusawa, Takashi; Ohtaka, Kinuka; Shimojima, Mie; Ohta, Hiroyuki

    2016-01-01

    Klebsormidium flaccidum is a charophytic alga living in terrestrial and semiaquatic environments. K. flaccidum grows in various habitats, such as low-temperature areas and under desiccated conditions, because of its ability to tolerate harsh environments. Wax and cuticle polymers that contribute to the cuticle layer of plants are important for the survival of land plants, as they protect against those harsh environmental conditions and were probably critical for the transition from aquatic microorganism to land plants. Bryophytes, non-vascular land plants, have similar, but simpler, extracellular waxes and polyester backbones than those of vascular plants. The presence of waxes in terrestrial algae, especially in charophytes, which are the closest algae to land plants, could provide clues in elucidating the mechanism of land colonization by plants. Here, we compared genes involved in the lipid biosynthetic pathways of Arabidopsis thaliana to the K. flaccidum and the Chlamydomonas reinhardtii genomes, and identified wax-related genes in both algae. A simple and easy extraction method was developed for the recovery of the surface lipids from K. flaccidum and C. reinhardtii. Although these algae have wax components, their surface lipids were largely different from those of land plants. We also investigated aliphatic substances in the cell wall fraction of K. flaccidum and C. reinhardtii. Many of the fatty acids were determined to be lipophilic monomers in K. flaccidum, and a Fourier transform infrared spectroscopic analysis revealed that their possible binding mode was distinct from that of A. thaliana. Thus, we propose that K. flaccidum has a cuticle-like hydrophobic layer composed of lipids and glycoproteins, with a different composition from the cutin polymer typically found in land plant cuticles. PMID:27446179

  18. Response of low latitude D-region ionosphere to the Total Solar Eclipse of 22 July 2009, deduced from ELF/VLF analysis

    NASA Astrophysics Data System (ADS)

    Singh, A. K.; Singh, R.; Singh, A. K.

    2011-12-01

    Response of the D-region of the ionosphere to the total solar eclipse of 22 July 2009 at low latitude, Varanasi (geomagnetic lat = 140 55'N, longitude = 1540 E, dip. angle = 37.30) was investigated using ELF/VLF radio signal. The solar eclipse started at 05:30:04.4 hrs IST and lasted up to 07:27 hrs IST with totally from 6.25 IST to 6.27 IST.The changes in D-region ionospheric VLF reflection heights and electron density during eclipse have been estimated from tweek analysis. The reflection height increased from ~90 km from the first occurrence of tweek to about 93-94 km at the totality and then decreased to ~89 km at the end of the eclipse. The reflection heights are lower by 2-3 km as compared to the usual nighttime tweek reflection heights. The electron density is found to vary between 25-27 cm-3 at the reflection heights. The significant increase in tweek reflection height of about 15 km during the eclipse as compared to the daytime (morning) reflection heights of ~ 78 km is observed. Observations suggest that about 30-40% obscuration of solar disc can lead to the tweeks occurrence which otherwise occur only in the nighttime. A significant increase of 3dB in the strength of the amplitude of VLF signal is observed around the time of TSE as compared to a control day. These low latitude ionospheric perturbations on the eclipse day are discussed and compared with other normal days. During a solar eclipse, the decrease in solar flux due to moon's shadow causes sudden change in the D-region physical and chemical processes. During the totality due to blocking of Lyman-α 1215Å (major D-region ionizing radiation) by moon's umbral shadow, the electron density decreases drastically towards the nighttime values [Smith, 1972]. During the TSE, there was no production of ionization in the ionosphere and the ions and electrons in the lowest part of it recombined at a rapid rate resulting a depletion in the electron density in the 'D' region of the Ionosphere and hence an increase in the effective width of the earth-ionosphere waveguide [Clivered et al., 2001] hence VLF reflection height. An increase in the height of this reflecting surface causes the waveguide "cutoff" frequency to decrease with a resulting decrease in phase velocity and increase in phase delay. Thus, the phase of the signal "lags," in accord with the observations. However, because of the 'decrease in "cutoff" frequency, the attenuation in the waveguide decreases, i.e., the amplitude of the signals increases. This is in accordance with the observed enhancement of the atmospherics/tweeks and increased amplitude strength. REFERENCES: Clilverd, M.A., C. J. Rodger, N. R. Thomsone, J. Lichtenberger, P. Steinbach, P. Cannon, and M. J. Angling, Total solar eclipse effects on VLF signals: Observations and modeling, Radio Sci. 36(4), 773 -788, 2001. Smith, L.G. (1972), Rocket observations of solar UV radiation during the eclipse of 7 March 1970, J. Atmos. Terr. Phys., 3(1), 601-611.

  19. On the accuracy of the relativistic parameters beta, gamma, and the solar oblateness coefficient J2, as deduced from ranging data of a drag-free space probe

    NASA Technical Reports Server (NTRS)

    Roth, E. A.

    1971-01-01

    Motion in the general gravity field is described mathematically. A covariance analysis, based on two simple models, is presented. Two drag-free space probes were considered, for which the orbital elements are given.

  20. The evolution of co-orbiting material in the orbit of 2201 Oljato from 1980 to 2012 as deduced from Pioneer Venus Orbiter and Venus Express magnetic records

    NASA Astrophysics Data System (ADS)

    Lai, Hairong; Russell, Christopher T.; Wei, Hanying; Zhang, Tielong

    2014-01-01

    Asteroid 2201 Oljato passed through perihelion inside the orbit of Venus near the time of its conjunction with Venus in 1980, 1983, and 1986. During those three years, many interplanetary field enhancements (IFEs) were observed by the Pioneer Venus Orbiter (PVO) in the longitude sector where the orbit of Oljato lies inside Venus' orbit. We attribute IFEs to clouds of fine-scale, possibly highly charged dust picked up by the solar wind after an interplanetary collision between objects in the diameter range of 10-1000 m. We interpret the increase rate in IFEs at PVO in these years as due to material in Oljato's orbit colliding with material in, or near to, Venus' orbital plane and producing a dust-anchored structure in the interplanetary magnetic field. In March 2012, almost 30 yr later, with Venus Express (VEX) now in orbit, the Oljato-Venus geometry is similar to the one in 1980. Here, we compare IFEs detected by VEX and PVO using the same IFE identification criteria. We find an evolution with time of the IFE rate. In contrast to the results in the 1980s, the recent VEX observations reveal that at solar longitudes in which the Oljato orbit is inside that of Venus, the IFE rate is reduced to the level even below the rate seen at solar longitudes where Oljato's orbit is outside that of Venus. This observation implies that Oljato not only lost its co-orbiting material but also disrupted the "target material," with which the co-orbiting material was colliding, near Venus.

  1. P-wave velocity structure in the southernmost source region of the 2011 Tohoku earthquakes, off the Boso Peninsula, deduced by an ocean bottom seismographic survey

    NASA Astrophysics Data System (ADS)

    Nakahigashi, Kazuo; Shinohara, Masanao; Mochizuki, Kimihiro; Yamada, Tomoaki; Hino, Ryota; Sato, Toshinori; Uehira, Kenji; Ito, Yoshihiro; Murai, Yoshio; Kanazawa, Toshihiko

    2012-12-01

    We present the result of a seismic experiment conducted using ocean bottom seismometers and controlled sources in the region off Ibaraki and the Boso Peninsula. This region is the southern edge of the rupture zone of the 2011 off the Pacific coast of Tohoku Earthquake. We estimated the P-wave seismic velocity structure beneath the profile using a 2-D ray-tracing method. The crustal structure in the southern area is more heterogeneous than that of the northern area. This heterogeneity is thought to be related with subducting the Philippine Sea plate (PHS). The plate boundary between the landward plate and the Pacific plate (PAC) is positioned at depths of 20 km at a distance of 170 km from the southern end of the profile. The subducting PHS is imaged on the southern part of the profile. However, we could not obtain a distinct image of the contact zone of PHS and PAC. The contact zone of PHS and PAC is estimated to have a large heterogeneity resulting from strong deformation due to the collision of the two plates. We infer that the termination of the rupture, and the large afterslip in the collision region, are caused by this strong heterogeneity.

  2. Seismicity near the hypocenter of the 2011 off the Pacific coast of Tohoku earthquake deduced by using ocean bottom seismographic data

    NASA Astrophysics Data System (ADS)

    Suzuki, Kensuke; Hino, Ryota; Ito, Yoshihiro; Yamamoto, Yojiro; Suzuki, Syuichi; Fujimoto, Hiromi; Shinohara, Masanao; Abe, Masao; Kawaharada, Yoshiharu; Hasegawa, Yohei; Kaneda, Yoshiyuki

    2012-12-01

    We relocated hypocenters of the foreshock, mainshock, and aftershocks of the 2011 off the Pacific coast of Tohoku earthquake ( M 9.0) in the middle part of the Japan Trench where the earthquake rupture initiated. Ocean Bottom Seismographs (OBSs), deployed in the area, recorded the earthquakes and these data provide improved images of the hypocenter distribution. The mainshock hypocenter was relocated slightly westward from that reported by Japan Meteorological Agency (JMA), placing it near the intersection between the plate boundary and the Moho of the overriding plate. The foreshock seismicity mainly occurred on the trenchward side of the mainshock hypocenter, where the Pacific slab contacts the island arc crust. The foreshocks were initially activated at the up-dip limit of the seismogenic zone ~30 km trenchward of the largest foreshock ( M 7.3, two days before the mainshock). After the M-7.3 earthquake, intense interplate seismicity, accompanied by epicenters migrating toward the mainshock hypocenter, was observed. The focal depth distribution changed significantly in response to the M-9 mainshock. Earthquakes along the plate boundary were almost non-existent in the area of huge coseismic slip, whereas earthquakes off the boundary increased in numbers in both the upper and the lower plates.

  3. Oceanographic parameters in continental margin of the State of Ceará (northeastern Brazil) deduced from C and O isotopes in foraminifers.

    PubMed

    Marques, Wanessa S; Menor, Eldemar de A; Sial, Alcides N; Manso, Valdir A V; Freire, Satander S

    2007-03-01

    Specimens of Recent foraminifera of Amphistegina radiata, Peneroplis planatus and Globigerinoides ruber, from fifty samples of surface sediments of the continental margin of the State of Ceará, Brazil, have been analyzed for carbon and oxygen isotopes to investigate oceanographic parameters and determine the values of delta18O of the oceanic water. From a comparison between values of delta18O obtained for ocean water using the linear equations by (Craig and Gordon 1965) and the one by Wolff et al. (1998), it became evident that the former yielded a more reliable value (0.2 per thousand SMOW) than the latter. Lower values of delta18O for the ocean water in this continental margin resulted from continental water influence. Values of 18O (-0.3 per thousand to -1.5 per thousand PDB for benthic foraminifera and -0.6 per thousand to -2.4 per thousand PDB for planktic foraminifera), attest to a variation of temperatures of oceanic water masses, in average, between 20 to 22 degrees C in deep water and 24 to 27 degrees C, in surface water. Values of delta13C from +3.2% to -0.2 per thousand PDB (benthic foraminifera) reflect a variation in the apparent oxygen utilization (AOU) in the continental margin and indicate that the environments of bacteriological decomposition of organic matter are not continuous along the investigated area.

  4. Aerial photographic surveys analyzed to deduce oil spill movement during the decay and breakup of fast ice, Prudhoe Bay, Alaska. Final report

    SciTech Connect

    Lissauer, I.M.; Baird, D.A.

    1982-09-01

    During the summers of 1979 and 1980 aerial photographs of the land fast ice north of Prudhoe Bay, Alaska, were taken. These photographs, covering two-week periods, highlight the decay and break-up of the land fast ice sheet. During the period of photography, wind speed, wind direction, barometric pressure, and tidal height measurements were recorded continuously. Several larger ice floes