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Sample records for 30s 31cl deduced

  1. Experimental Investigation of the Stellar Reaction 30S(p,γ)31Cl via Coulomb Dissociation

    NASA Astrophysics Data System (ADS)

    Togano, Y.; Motobayashi, T.; Aoi, N.; Baba, H.; Bishop, S.; Cai, X.; Doornenbal, P.; Fang, D.; Furukawa, T.; Ieki, K.; Iwasa, N.; Kawabata, T.; Kanno, S.; Kobayashi, N.; Kondo, Y.; Kuboki, T.; Kume, N.; Kurita, K.; Kurokawa, M.; Ma, Y. G.; Matsuo, Y.; Murakami, H.; Matsushita, M.; Nakamura, T.; Okada, K.; Ota, S.; Satou, Y.; Shimoura, S.; Shioda, R.; Tanaka, K. N.; Takeuchi, S.; Tian, W.; Wang, H.; Wang, J.; Yamada, K.; Yamada, Y.; Yoneda, K.

    2011-09-01

    Coulomb dissociation of the proton-rich nucleus 31Cl was studied experimentally using a 31Cl beam at 58 MeV/nucleon with a lead target. The relative energy spectrum of 30S+p system was obtained from the measured momentum vectors of the reaction products detected in coincidence by the invariant mass method. The first excited state in 31Cl was observed which is relevant to the resonant capture in the stellar 30S(p,γ)31Cl reaction. Discussion for another observed state is also given.

  2. 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.

  3. 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

  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

    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.

  6. 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

  7. 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

  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. {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.

  11. 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.

  12. {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.

  13. The Cryo-EM structure of a complete 30S translation initiation complex from Escherichia coli.

    PubMed

    Julián, Patricia; Milon, Pohl; Agirrezabala, Xabier; Lasso, Gorka; Gil, David; Rodnina, Marina V; Valle, Mikel

    2011-07-01

    Formation of the 30S initiation complex (30S IC) is an important checkpoint in regulation of gene expression. The selection of mRNA, correct start codon, and the initiator fMet-tRNA(fMet) requires the presence of three initiation factors (IF1, IF2, IF3) of which IF3 and IF1 control the fidelity of the process, while IF2 recruits fMet-tRNA(fMet). Here we present a cryo-EM reconstruction of the complete 30S IC, containing mRNA, fMet-tRNA(fMet), IF1, IF2, and IF3. In the 30S IC, IF2 contacts IF1, the 30S subunit shoulder, and the CCA end of fMet-tRNA(fMet), which occupies a novel P/I position (P/I1). The N-terminal domain of IF3 contacts the tRNA, whereas the C-terminal domain is bound to the platform of the 30S subunit. Binding of initiation factors and fMet-tRNA(fMet) induces a rotation of the head relative to the body of the 30S subunit, which is likely to prevail through 50S subunit joining until GTP hydrolysis and dissociation of IF2 take place. The structure provides insights into the mechanism of mRNA selection during translation initiation. PMID:21750663

  14. The Cryo-EM Structure of a Complete 30S Translation Initiation Complex from Escherichia coli

    PubMed Central

    Julián, Patricia; Milon, Pohl; Agirrezabala, Xabier; Lasso, Gorka; Gil, David; Rodnina, Marina V.; Valle, Mikel

    2011-01-01

    Formation of the 30S initiation complex (30S IC) is an important checkpoint in regulation of gene expression. The selection of mRNA, correct start codon, and the initiator fMet-tRNAfMet requires the presence of three initiation factors (IF1, IF2, IF3) of which IF3 and IF1 control the fidelity of the process, while IF2 recruits fMet-tRNAfMet. Here we present a cryo-EM reconstruction of the complete 30S IC, containing mRNA, fMet-tRNAfMet, IF1, IF2, and IF3. In the 30S IC, IF2 contacts IF1, the 30S subunit shoulder, and the CCA end of fMet-tRNAfMet, which occupies a novel P/I position (P/I1). The N-terminal domain of IF3 contacts the tRNA, whereas the C-terminal domain is bound to the platform of the 30S subunit. Binding of initiation factors and fMet-tRNAfMet induces a rotation of the head relative to the body of the 30S subunit, which is likely to prevail through 50S subunit joining until GTP hydrolysis and dissociation of IF2 take place. The structure provides insights into the mechanism of mRNA selection during translation initiation. PMID:21750663

  15. 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…

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

    PubMed

    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

    2015-07-01

    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. PMID:26798805

  17. 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.

  18. 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.

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

    DOE PAGESBeta

    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. First measurement of the 33Cl(p,α)30S reaction

    NASA Astrophysics Data System (ADS)

    Deibel, C. M.; Rehm, K. E.; Figueira, J. M.; Greene, J. P.; Jiang, C. L.; Kay, B. P.; Lee, H. Y.; Lighthall, J. C.; Marley, S. T.; Pardo, R. C.; Patel, N.; Paul, M.; Ugalde, C.; Woodard, A.; Wuosmaa, A. H.; Zinkann, G.

    2011-10-01

    The 30S(α,p)33Cl reaction may have a significant impact on final elemental abundances and energy output of type I X-ray bursts, as well as influencing observables such as double-peaked luminosity profiles, because it could bypass the 30S waiting point. This reaction has been studied experimentally for the first time in inverse kinematics via the time-inverse reaction 1H(33Cl,30S)α with a 33Cl radioactive ion beam produced at the Argonne Tandem Linac Accelerator System facility by the “in-flight” technique. This reaction was studied at three different beam energies. The experimental method used and the resulting data are discussed.

  1. 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.

  2. Effect of intermittent hypoxic training on 20 km time trial and 30 s anaerobic performance.

    PubMed

    Hamlin, M J; Marshall, H C; Hellemans, J; Ainslie, P N; Anglem, N

    2010-08-01

    This study aimed to verify whether the "live low, train high" approach is beneficial for endurance and/or anaerobic cycling performance. Sixteen well-trained athletes completed 90 min of endurance training (60-70% of heart rate reserve), followed by two 30-s all-out sprints (Wingate test), daily, for 10 consecutive days. Nine subjects [intermittent hypoxic training (IHT) group] trained with an F(I)O(2) set to produce arterial oxygen saturations of approximately 88-82%, while seven subjects (placebo group) trained while breathing a normal gas mixture (F(I)O(2)=0.21). Four performance tests were conducted at sea level including a familiarization and baseline trial, followed by repeat trials at 2 and 9 days post-intervention. Relative to the placebo group, the mean power during the 30-s Wingate test increased by 3.0% (95% confidence limits, CL +/- 3.5%) 2 days, and 1.7% (+/- 3.8%) 9 days post-IHT. Changes in other performance variables (30 s peak power, 20 km mean power and 20 km oxygen cost) were unclear. During the time trial, the IHT participants' blood lactate concentration, respiratory exchange ratio, and SpO(2), relative to the placebo group, was substantially increased at 2 days post-intervention. The addition of IHT to the normal training program of well-trained athletes produced worthwhile gains in 30 s sprint performance possibly through enhanced glycolysis. PMID:19793215

  3. Studies on dissociation and reconstitution of nuclear 30-S ribonucleoprotein particles containing pre-mRNA.

    PubMed

    Kulguskin, V V; Krichevskaya, A A; Lukanidin, E M; Georgiev, G P

    1980-10-17

    Treatment of nuclear 30-S ribonucleoprotein (RNP) particles containing pre-mRNA (precursor of mRNA) with 2 M NaCl leads to dissociation of RNA and protein. The protein component is present either as an aggregate with a sedimentation coefficient close to 30 S (a free informofer) or as a slowly sedimenting material (monomers or oligomers of informatin). Most of the informofers and slowly sedimenting material are in the equilibrium state. Iodination or aging of the 30-S particles stabilizes informofers. Lowering of NaCl concentration in the mixture of RNA with informofers or informatin subunits leads to reconstitution of RNP particles. In both cases, the particles formed have a sedimentation coefficient of about 30 S and a buoyant density equal to 1.4-1.41 g/cm3 but their response to pancreatic RNAase (EC 3.1.27.5) and high salt treatment is very different. Both the particles reconstituted from RNA and informofers and the original particles are very sensitive to pancreatic RNAase and after high salt treatment free informofers are formed. In contrast, the RNA of the particles reconstituted from slowly sedimenting material is much more protected against pancreatic RNAase action. These particles are also rather stable to high salt treatment. Thus, only if a protein in the form of an informofer aggregate is used, faithful reconstitution takes place. The data obtained are discussed in terms of the structure of the nuclear ribonucleoprotein particles containing precursor of messenger RNA. PMID:7437433

  4. Precipitation processes as deduced by combining Doppler radar and disdrometer

    NASA Astrophysics Data System (ADS)

    Thomson, Alan Douglas

    Precipitation processes are investigated in stratiform and convective weather systems by combining Doppler radar and disdrometer measurements. Vertical scans are designed to measure the standard radar data fields and the power spectrum of the vertical Doppler velocities with high spatial and temporal resolution. A new method, based on iterative application of a disdrometer-determined Z-R relation, is developed to estimate vertical winds from the vertical scan data. Using this method, radar-based raindrop size spectra calculated near the surface in light stratiform rain compare well with simultaneous measurements from a collocated disdrometer. A full raindrop size spectrum profile is deduced for a specific steady state case. It is found that the spectrum does not vary with height, suggesting that the spectral shape is mainly controlled by the ice particles occurring above the 0oC level. Vertical scan data are also combined with volume scan data obtained by the Atmospheric Environment Service King City radar to examine the precipitation structure of a hail producing region within a severe squall line. The vertical scan shows a large variation in precipitation structure and also reveals important storm features which, in this case, are not detected by the conventional volume scans, such as a weak echo vault, a downdraught outflow, and streaks of very high downward velocity corresponding to separate hail trajectories. The power spectra were used to identify and locate hailstones, to deduce the growth of descending hailstones, and to qualitatively examine properties of raindrop size spectra. A conceptual model of hail formation is proposed by comparing the deduced storm structure and precipitation processes with the analyses of two somewhat similar storms documented in the literature.

  5. Visualizing ribosome biogenesis: parallel assembly pathways for the 30S subunit.

    PubMed

    Mulder, Anke M; Yoshioka, Craig; Beck, Andrea H; Bunner, Anne E; Milligan, Ronald A; Potter, Clinton S; Carragher, Bridget; Williamson, James R

    2010-10-29

    Ribosomes are self-assembling macromolecular machines that translate DNA into proteins, and an understanding of ribosome biogenesis is central to cellular physiology. Previous studies on the Escherichia coli 30S subunit suggest that ribosome assembly occurs via multiple parallel pathways rather than through a single rate-limiting step, but little mechanistic information is known about this process. Discovery single-particle profiling (DSP), an application of time-resolved electron microscopy, was used to obtain more than 1 million snapshots of assembling 30S subunits, identify and visualize the structures of 14 assembly intermediates, and monitor the population flux of these intermediates over time. DSP results were integrated with mass spectrometry data to construct the first ribosome-assembly mechanism that incorporates binding dependencies, rate constants, and structural characterization of populated intermediates. PMID:21030658

  6. All-atom homology model of the Escherichia coli 30S ribosomal subunit.

    PubMed

    Tung, Chang-Shung; Joseph, Simpson; Sanbonmatsu, Kevin Y

    2002-10-01

    Understanding the structural basis of ribosomal function requires close comparison between biochemical and structural data. Although a large amount of biochemical data are available for the Escherichia coli ribosome, the structure has not been solved to atomic resolution. Using a new RNA homology procedure, we have modeled the all-atom structure of the E. coli 30S ribosomal subunit. We find that the tertiary structure of the ribosome core, including the A-, P- and E-sites, is highly conserved. The hypervariable regions in our structure, which differ from the structure of the 30S ribosomal subunit from Thermus thermophilus, are consistent with the cryo-EM map of the E. coli ribosome. PMID:12244297

  7. Power and peak blood lactate at 5050 m with 10 and 30 s 'all out' cycling.

    PubMed

    Grassi, B; Mognoni, P; Marzorati, M; Mattiotti, S; Marconi, C; Cerretelli, P

    2001-07-01

    Anecdotal observations suggest that the reduction in peak lactate accumulation in blood ([La]b peak) after exhausting exercise, in chronic hypoxia vs. normoxia, may be related to the duration of the exercise protocol, being less pronounced after short supramaximal exercise than after incremental exercise (IE) lasting several minutes. To test this hypothesis, six healthy male Caucasians (age 36.8 +/- 7.3, X +/- SD) underwent three exercise protocols on a cycle ergometer, at sea level (SL) and after 21 +/- 10 days at 5050 m altitude (ALT): (1) 10 s, (2) 30 s 'all out' exercise and (3) IE leading to exhaustion in approximately 20-25 min. 'Average' power output (P) was calculated for 10 or 30 s 'all out'; maximal power output (Pmax) was determined for IE. Lactate concentration in arterialized capillary blood ([La]b) was measured at rest and at different times during recovery; the highest [La]b during recovery was taken as [La]b peak. No significant differences in P were observed between SL and ALT, for either 10 or 30 s 'all out' exercise; Pmax during IE was significantly lower at ALT than at SL. [La]b peak after 10 s 'all out' was unaffected by chronic hypoxia (7.0 +/- 0.9 at ALT vs. 6.3 +/- 1.8 mmol x L(-1) at SL). After 30 s 'all out' the [La]b peak decrease, at ALT (10.6 +/- 0.6 mmol x L(-1)) vs. SL (12.9 +/- 1.4 mmol x L(-1)), was only approximately 50% of that observed for IE (6.7 +/- 1.6 mmol x L(-1) vs. 11.3 +/- 2.8 mmol x L(-1)). Muscle power output and blood lactate accumulation during short supramaximal exercise are substantially unaffected by chronic hypoxia. PMID:11472305

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Detection of mRNA sequences in nuclear 30S ribonucleoprotein subcomplexes.

    PubMed Central

    Kinniburgh, A J; Martin, T E

    1976-01-01

    RNA from nuclear 30S ribonucleoprotein (RNP) complexes of mouse ascites cells has been shows to contain sequences homologous to poly(A) + mRNA by its ability to hybridize with complementary DNA prepared from poly(A) + mRNA template. Analysis of the hybridization kinetics of poly(A) + mRNA with its own complementary DNA revealed several abundancy classes. The total complexity of poly(A) + mRNA from ascites cells was estimated to be approximately 30,000 sequences of average molecular weight (6 X 10(5)). When the hybridization reaction of 30S RNP-RNA with mRNA-specific cDNA was compared to the homologous reaction the majority, and most probably all, of the poly(A) + mRNA sequences were found to be present in the RNA. The kinetics of hybridization suggest that 10-15% of the RNA in this RNP complex is homologous to poly(A) + mRNA. The 30S RNP subcomplexes therefore contain nuclear poly(A) + mRNA sequences as well as the bulk of heterogeneous RNA. PMID:1066686

  13. Polar stratospheric clouds as deduced from MLS and CLAES measurements

    SciTech Connect

    Ricaud, P.D.; Carr, E.S.; Harwood, R.S.; Lahoz, W.A.

    1995-08-01

    From 30 August 1992 to 3 September 1992 a supersaturated area at 465 K potential temperature ({approximately}50 hPa) is deduced from MLS water vapour measurements over western Antarctica, where high extinction coefficients measured by CLAES indicate Polar Stratospheric Clouds (PSCs). These PSCs are attributed partly to the effect of an anticyclone located over South America and partly to localized orographic waves, which raise the isentropes and generate rapid adiabatic cooling. A local minimum in column O{sub 3} ({<=}200DU) is observed in this area, which is believed to be a consequence of the dynamics. Enhanced ClO abundances downstream of the region indicate PSC processing and chlorine activation. 18 refs., 2 figs.

  14. 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.

  15. 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.

  16. Low-latitude field-aligned currents deduced by Swarm

    NASA Astrophysics Data System (ADS)

    Lühr, Hermann; Kervalishvili, Guram; Rauberg, Jan

    2015-04-01

    ESA's constellation mission Swarm was successfully launched on 22 November 2013. The three satellites are orbiting the Earth at 470 km and 520 km altitude. The lower pair Swarm-A and C is flying side-by-side separated by only 1.4° in latitude. Magnetic field readings of this pair are used to determine for the first time field-aligned currents (FAC) uniquely in the ionosphere. Of particular interest for this presentation are FACs at low and equatorial latitudes. Indications for several of such current systems have been deduced from CHAMP observations. Examples to be studied are meridional and vertical currents driven by the F-region dynamo. They are expected to show opposite polarities between noon and sunset. Likewise there are FACs expected to balance the electric potential differences between the foci of the Sq current vortices in the two hemispheres, which should be most prominent during solstice seasons. Another example is the FAC associated with equatorial plasma bubbles. They are expected to flow along the walls of the electron density depleted volume. Due to the limited amount of suitable Swarm data we will focus on June solstice and September equinox 2014 for this presentation.

  17. Characterization of GE82832, a peptide inhibitor of translocation interacting with bacterial 30S ribosomal subunits

    PubMed Central

    Brandi, Letizia; Fabbretti, Attilio; Stefano, Michele Di; Lazzarini, Ameriga; Abbondi, Monica; Gualerzi, Claudio O.

    2006-01-01

    GE82832, a secondary metabolite produced by Streptosporangium cinnabarinum (strain GE82832), has been identified as a translational inhibitor by in vitro screening of a library of natural products. Secondary functional tests specific for individual steps of the translational pathway demonstrated that translocation is the specific target of GE82832. Chemical probing in situ demonstrated that this antibiotic protects bases A1324 and A1333 and exposes C1336 of 16S rRNA, thereby indicating that its binding site is located on the head of the 30S ribosomal subunit. The ribosomal location of GE82832, near ribosomal protein S13 and G1338, two elements of the small subunit that are part of or close to the B1a intrasubunit bridge, suggests that translocation inhibition results from an altered dynamics of 30S–50S ribosomal subunit interaction. PMID:16699167

  18. Anaerobic energy release in working muscle during 30 s to 3 min of exhausting bicycling.

    PubMed

    Medbø, J I; Tabata, I

    1993-10-01

    To examine the anaerobic energy release during intense exercise, 16 healthy young men cycled as long as possible at constant powers chosen to exhaust the subjects in approximately 30 s, 1 min, or 2-3 min. Muscle biopsies were taken before and approximately 10 s after exercise and analyzed for lactate, phosphocreatine (PCr), and other metabolites. O2 uptake was measured for determination of the accumulated O2 deficit (a whole body measure of the anaerobic energy release), and this indirect measure of the anaerobic energy release was compared with a direct value obtained from measured muscle metabolites. Muscle lactate concentration rose by 30.0 +/- 1.2 mmol/kg and muscle PCr concentration fell by 12.4 +/- 0.9 mmol/kg during the 2-3 min of exhausting exercise. The anaerobic ATP production was consequently 58 +/- 2 mmol/kg wet muscle mass, which may be the maximum anaerobic energy release for human muscle during bicycling. Because the anaerobic ATP production was 6 and 32% less for 1 min and 30 s of exercise, respectively, than for 2 min of exercise (P < 0.03), 2 min of exhausting exercise may be required for maximal use of anaerobic sources. Lactate production provided three times more ATP than PCr breakdown for all three exercise durations. There was a close linear relationship between the rates of anaerobic ATP production in muscle and the value estimated for the whole body by the O2 deficit (r = 0.94). This suggests that the accumulated O2 deficit is a valid measure of the anaerobic energy release during bicycling. PMID:8282617

  19. Motives for physical activity among active and inactive persons in their mid-30s.

    PubMed

    Aaltonen, S; Rottensteiner, M; Kaprio, J; Kujala, U M

    2014-08-01

    The purpose of this study was to examine the motives for leisure-time physical activity among active and inactive men and women in their mid-30s. We used both cross-sectional and longitudinal designs. Altogether, 2308 participants (mean age 33.9 years, 53.4% women) were identified from the population-based FinnTwin16 Cohort. Physically active and inactive individuals were identified on the basis of their leisure-time MET h/day. We evaluated participants' physical activity motivation with a modified version of the Recreational Exercise Motivation Measure. Comparisons between active and inactive individuals were analysed using the Wald test for equality of means, and effect sizes were calculated as Cohen's d. Motives related to mastery, physical fitness, social aspect of physical activity, psychological state, enjoyment, willingness to be fitter/look better than others, and appearance were significantly more important for the active than inactive participants. Conforming to others' expectations was the only item on which the inactive persons scored higher than active persons. The longitudinal results for physical activity were parallel to the cross-sectional results. This study supports the view that motivation factors differ between active and inactive persons, and that intrinsic motives are associated with consistent leisure-time physical activity. PMID:23331765

  20. 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

  1. 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

  2. Characteristics of a long-pulse (30-s), high-power (4-MW) ion source for neutral beam injection

    SciTech Connect

    Menon, M.M.; Barber, G.C.; Combs, S.K.; Dagenhart, W.K.; Gardner, W.L.; Haselton, H.H.; Moeller, J.A.; Ponte, N.S.; Ryan, P.M.; Schechter, D.E.

    1983-01-01

    A quasi-steady-state ion source has been developed for neutral beam injection applications. It is of the duoPIGatron type designed for delivering 50 A of hydrogen ions at 80 keV for 30-s-long pulses. Ion beams of 40 A at 75 keV were extracted for pulse lengths up to 30 s, maintaining excellent optical quality in the beam for the entire pulse duration. The design features and operational characteristics of the ion source are elaborated.

  3. 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. PMID:25198533

  4. 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

  5. Conformation of 4.5S RNA in the signal recognition particle and on the 30S ribosomal subunit

    PubMed Central

    GU, SHAN-QING; JÖCKEL, JOHANNES; BEINKER, PHILIPP; WARNECKE, JENS; SEMENKOV, YURI P.; RODNINA, MARINA V.; WINTERMEYER, WOLFGANG

    2005-01-01

    The signal recognition particle (SRP) from Escherichia coli consists of 4.5S RNA and protein Ffh. It is essential for targeting ribosomes that are translating integral membrane proteins to the translocation pore in the plasma membrane. Independently of Ffh, 4.5S RNA also interacts with elongation factor G (EF-G) and the 30S ribosomal subunit. Here we use a cross-linking approach to probe the conformation of 4.5S RNA in SRP and in the complex with the 30S ribosomal subunit and to map the binding site. The UV-activatable cross-linker p-azidophenacyl bromide (AzP) was attached to positions 1, 21, and 54 of wild-type or modified 4.5S RNA. In SRP, cross-links to Ffh were formed from AzP in all three positions in 4.5S RNA, indicating a strongly bent conformation in which the 5′ end (position 1) and the tetraloop region (including position 54) of the molecule are close to one another and to Ffh. In ribosomal complexes of 4.5S RNA, AzP in both positions 1 and 54 formed cross-links to the 30S ribosomal subunit, independently of the presence of Ffh. The major cross-linking target on the ribosome was protein S7; minor cross-links were formed to S2, S18, and S21. There were no cross-links from 4.5S RNA to the 50S subunit, where the primary binding site of SRP is located close to the peptide exit. The functional role of 4.5S RNA binding to the 30S subunit is unclear, as the RNA had no effect on translation or tRNA translocation on the ribosome. PMID:16043501

  6. The French Zones d'Education Prioritaire: Much Ado about Nothing?

    ERIC Educational Resources Information Center

    Benabou, Roland; Kramarz, Francis; Prost, Corinne

    2009-01-01

    We provide an assessment of the French ZEP (Zones d'Education Prioritaire), a program started in 1982 that channels additional resources to schools in disadvantaged areas and encourages the development of new teaching projects. Focusing on middle-schools, we first evaluate the impact of the ZEP status on resources, their utilization (teacher…

  7. 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...

  8. 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…

  9. 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

  10. Differential effects of ribosomal proteins and Mg2+ ions on a conformational switch during 30S ribosome 5'-domain assembly.

    PubMed

    Abeysirigunawardena, Sanjaya C; Woodson, Sarah A

    2015-11-01

    Ribosomal protein S4 nucleates assembly of the 30S ribosome 5' and central domains, which is crucial for the survival of cells. Protein S4 changes the structure of its 16S rRNA binding site, passing through a non-native intermediate complex before forming native S4-rRNA contacts. Ensemble FRET was used to measure the thermodynamic stability of non-native and native S4 complexes in the presence of Mg(2+) ions and other 5'-domain proteins. Equilibrium titrations of Cy3-labeled 5'-domain RNA with Cy5-labeled protein S4 showed that Mg(2+) ions preferentially stabilize the native S4-rRNA complex. In contrast, ribosomal proteins S20 and S16 act by destabilizing the non-native S4-rRNA complex. The full cooperative switch to the native complex requires S4, S16, and S20 and is achieved to a lesser degree by S4 and S16. The resulting thermodynamic model for assembly of the 30S body illustrates how ribosomal proteins selectively bias the equilibrium between alternative rRNA conformations, increasing the cooperativity of rRNA folding beyond what can be achieved by Mg(2+) ions alone. PMID:26354770

  11. Positions of S2, S13, S16, S17, S19 and S21 in the 30 S ribosomal subunit of Escherichia coli.

    PubMed

    Capel, M S; Kjeldgaard, M; Engelman, D M; Moore, P B

    1988-03-01

    Neutron scattering distance data are presented for 33 protein pairs in the 30 S ribosomal subunit from Escherichia coli, along with the methods used for measuring distances between its exchangeable components. When combined with prior data, these new results permit the positioning of S2, S13, S16, S17, S19 and S21 in the 30 S ribosomal subunit, completing the mapping of its proteins by neutron scattering. Comparisons with other data suggest that the neutron map is a reliable guide to the quaternary structure of the 30 S subunit. PMID:3288761

  12. The DEDUCE Guided Query tool: providing simplified access to clinical data for research and quality improvement.

    PubMed

    Horvath, Monica M; Winfield, Stephanie; Evans, Steve; Slopek, Steve; Shang, Howard; Ferranti, Jeffrey

    2011-04-01

    In many healthcare organizations, comparative effectiveness research and quality improvement (QI) investigations are hampered by a lack of access to data created as a byproduct of patient care. Data collection often hinges upon either manual chart review or ad hoc requests to technical experts who support legacy clinical systems. In order to facilitate this needed capacity for data exploration at our institution (Duke University Health System), we have designed and deployed a robust Web application for cohort identification and data extraction--the Duke Enterprise Data Unified Content Explorer (DEDUCE). DEDUCE is envisioned as a simple, web-based environment that allows investigators access to administrative, financial, and clinical information generated during patient care. By using business intelligence tools to create a view into Duke Medicine's enterprise data warehouse, DEDUCE provides a Guided Query functionality using a wizard-like interface that lets users filter through millions of clinical records, explore aggregate reports, and, export extracts. Researchers and QI specialists can obtain detailed patient- and observation-level extracts without needing to understand structured query language or the underlying database model. Developers designing such tools must devote sufficient training and develop application safeguards to ensure that patient-centered clinical researchers understand when observation-level extracts should be used. This may mitigate the risk of data being misunderstood and consequently used in an improper fashion. PMID:21130181

  13. Deducing lightning locations and charge moment change by ELF observations around Japan

    NASA Astrophysics Data System (ADS)

    Inoue, T.; Hobara, Y.; Hayakawa, M.; Shiokawa, K.

    2011-12-01

    The electromagnetic radiations from lightning discharges have been intensively studied for a long time by using different frequency ranges. Recent observations of electromagnetic radiations from lightning in the ELF frequency range so-called ELF transients are recognized as a powerful tool not only to deduce the global lightning distribution but also to obtain one of the most important properties of lightning discharges such as charge moment changes (Qds). Although accurate Qds for the lightning discharges can be deduced from the static electric field measurement by using e.g. electric field mill, the detection ranges of this equipment is significantly limited in space (typically within few decade of km). Therefore Qds distributions of local thunderstorm activities over the spatial scale of Japan (within few thousands km) have not been studied yet. In this paper, we report the initial results of local ELF network observations (i.e. multiple observations over Japan) to deduce the spatio-temporal lightning discharge distributions with a charge moment change of the thunderstorm activity around Japan. The statistical properties of the charge moment changes will be presented as well.

  14. Comparisons of Satellite-Deduced Overlapping Cloud Properties and CALIPSO CloudSat Data

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Introduction to the overlapped cloud properties derived from polar-orbiting (MODIS) and geostationary (GOES-12, -13, Meteosat-8, -9, etc.) meteorological satellites, which are produced at the NASA Langley Research Center (LaRC) cloud research & development team (NASA lead scientist: Dr. Patrick Minnis). Comparison of the LaRC CERES MODIS Edition-3 overlapped cloud properties to the CALIPSO and the CloudSat active sensing data. High clouds and overlapped clouds occur frequently as deduced by CALIPSO (44 & 25%), CloudSat (25 & 4%), and MODIS (37 & 6%). Large fractions of optically-thin cirrus and overlapped clouds are deduced from CALIPSO, but much smaller fractions are from CloudSat and MODIS. For overlapped clouds, the averaged upper-layer CTHs are about 12.8 (CALIPSO), 10.9 (CloudSat) and 10 km (MODIS), and the averaged lower-layer CTHs are about 3.6 (CALIPSO), 3.2 (CloudSat) and 3.9 km (MODIS). Based on comparisons of upper and lower-layer cloud properties as deduced from the MODIS, CALIPSO and CloudSat data, more enhanced passive satellite methods for retrieving thin cirrus and overlapped cloud properties are needed and are under development.

  15. 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

  16. 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

  17. S-adenosylmethionine directly inhibits binding of 30S ribosomal subunits to the SMK box translational riboswitch RNA

    PubMed Central

    Fuchs, Ryan T.; Grundy, Frank J.; Henkin, Tina M.

    2007-01-01

    The SMK box is a conserved riboswitch motif found in the 5′ untranslated region of metK genes [encoding S-adenosylmethionine (SAM) synthetase] in lactic acid bacteria, including Enterococcus, Streptococcus, and Lactococcus sp. Previous studies showed that this RNA element binds SAM in vitro, and SAM binding causes a structural rearrangement that sequesters the Shine–Dalgarno (SD) sequence by pairing with an anti-SD (ASD) element. A model was proposed in which SAM binding inhibits metK translation by preventing binding of the ribosome to the SD region of the mRNA. In the current work, the addition of SAM was shown to inhibit binding of 30S ribosomal subunits to SMK box RNA; in contrast, the addition of S-adenosylhomocysteine (SAH) had no effect. A mutant RNA, which has a disrupted SD-ASD pairing, was defective in SAM binding and showed no reduction of ribosome binding in the presence of SAM, whereas a compensatory mutation that restored SD-ASD pairing restored the response to SAM. Primer extension inhibition assays provided further evidence for SD-ASD pairing in the presence of SAM. These results strongly support the model that SMK box translational repression operates through occlusion of the ribosome binding site and that SAM binding requires the SD-ASD pairing. PMID:17360376

  18. Pollen analyses from a 50 000-yr rodent midden series in the southern Atacama Desert (25° 30 S)

    NASA Astrophysics Data System (ADS)

    Maldonado, Antonio; Betancourt, Julio L.; Latorre, Claudio; Villagran, Carolina

    2005-07-01

    Precipitation in northern Chile is controlled by two great wind belts - the southern westerlies over the southern Atacama and points south (> 24° S) and the tropical easterlies over the northern and central Atacama Desert (16-24° S). At the intersection of these summer and winter rainfall regimes, respectively, is a Mars-like landscape consisting of expansive surfaces devoid of vegetation (i.e. absolute desert) except in canyons that originate high enough to experience runoff once every few years. Pollen assemblages from 39 fossil rodent middens in one of these canyons, Quebrada del Chaco (25° 30 S), were used to infer the history of vegetation and precipitation at three elevations (2670-2800 m; 3100-3200 m; 3450-3500 m) over the past 50 000 years. When compared to modern conditions and fossil records to the north and south, the pollen evidence indicates more winter precipitation at > 52, 40-33, 24-17 k cal. yr BP, more precipitation in both seasons at 17-14 k cal. yr BP, and more summer precipitation from 14-11 k cal.yrBP. Younger middens are scarce at Quebrada del Chaco, and the few Holocene samples indicate hyperarid conditions comparable to today. The only exception is a pollen assemblage that indicates a brief but significant interlude of increased winter precipitation in the last millennium. Copyright

  19. Deduced primary structure of two forms of vitellogenin in Japanese common goby (Acanthogobius flavimanus).

    PubMed

    Ohkubo, N; Andoh, T; Mochida, K; Adachi, S; Hara, A; Matsubara, T

    2004-05-15

    Complete nucleotide sequences of two forms of vitellogenin (Vg) cDNA in Japanese common goby were determined from a liver cDNA library of E(2)-treated male fish. These two Vg cDNAs contained complete open reading frames encoding 1664 and 1238 amino acid residues including signal peptides, respectively. From comparison of the deduced amino acid sequences of both Vgs and the partial amino acid sequences of the yolk proteins, the longer sequence was concluded to be cDNA of the Vg-530 and the shorter one was that of the Vg-320 of the Japanese common goby which were reported in our previous paper. The deduced sequence of Vg-530 without signal peptide was arranged by lipovitellin heavy-chain (LvH), phosvitin (Pv), lipovitellin light-chain (LvL), and beta'-component beta'-c) domains from the N-terminus, and showed a range of 40-45% sequence identity to those of other fish. Furthermore, the deduced sequence of Vg-320 showed no obvious Pv domain, has a shortened C-terminal coding region after the LvH domain, and showed a close similarity to the phosvitin-less Vg of zebrafish. Moreover, biochemical analysis of the yolk proteins verified that Vg-530 cleaves into the Lv-Pv complex (molecular mass: 470 kDa) and beta'-c (33 kDa), while Vg-320 showed no change when incorporated into oocytes. The present study demonstrated the existence of the two different forms of Vgs at both the cDNA and protein level, and showed molecular alteration of the two Vgs during vitellogenesis. Two Vg sequence data will aid in designing nucleotide probes for detecting Vg gene expressions as a biomarker of environmental estrogens. PMID:15094332

  20. Systematics of the deduced fission barriers for the doubly even transactinium nuclei

    SciTech Connect

    Bhandari, B.S.; Bendardaf, Y.B. )

    1992-06-01

    The systematics of the fission barrier shapes of a total of 47 doubly even actinide and transactinide nuclei have been studied using the double-humped fission barrier model. The fission barrier has been parametrized in terms of four smoothly joined parabolic segments. The penetrabilities through such double-humped fission barriers have been calculated in the Wentzel-Kramers-Brillouin approximation, and the various fission half-lives have been determined using the formalism given earlier by Nix and Walker. The various parameters of such fission barriers have been deduced by requiring their simultaneous consistency with the various relevant fission observables, namely, the near-barrier fission cross sections, isomeric energies and isomeric half-lives, where available, and the ground-state spontaneous fission half-lives in the region 90{le}{ital Z}{le}98, and such model calculations with some further justifiable asssumptions have been extended to the region of the still heavier nuclei with {ital Z}{ge}100. The results of our systematic study of the heights of the inner and the outer barriers of the double-humped fission barriers corresponding to such doubly even nuclei suggest that while the height of the inner barrier remains approximately constant in the entire region of such nuclei, the deduced heights of the outer barrier decrease rather sharply and continuously with the increase in the value of the fissility parameter until one reaches the element Rf ({ital Z}=104).

  1. What are the causes for the spread of GLE parameters deduced from NM data?

    NASA Astrophysics Data System (ADS)

    Bütikofer, R.; Flückiger, E.

    2015-08-01

    Investigations have shown that the analysis results of ground level enhancements (GLEs) based on neutron monitor (NM) data for a selected event can differ considerably depending the procedure used. This may have significant consequences e.g. for the assessment of radiation doses at flight altitudes. The reasons for the spread of the GLE parameters deduced from NM data can be manifold and are at present unclear. They include differences in specific properties of the various analysis procedures (e.g. NM response functions, different ways in taking into account the dynamics of the Earth's magnetospheric field), different characterisations of the solar particle flux near Earth as well as the specific selection of NM stations used for the analysis. In the present paper we quantitatively investigate this problem for a time interval during the maximum phase of the GLE on 13 December 2006. We present and discuss the changes in the resulting GLE parameters when using different NM response functions, different model representations of the Earth's magnetospheric field as well as different assumptions for the solar particle spectrum and pitch angle distribution near Earth. The results of the study are expected to yield a basis for the reduction in the spread of the GLE parameters deduced from NM data.

  2. 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.

  3. 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. PMID:25389215

  4. Deducing ink thickness variations of fluorescent print by a spectral prediction model

    NASA Astrophysics Data System (ADS)

    Wang, Qingjuan; Zhang, Yixin; Tian, Dongwen

    2012-01-01

    In the color printing process, the thickness and uniformity of ink have a great affect on the color reproduction. The ink thickness uniformity is an important parameters of measuring the quality of printing. Based on the fluorescent additives may absorb ultraviolet light and exit blue light or visible light and by considering the expansion of the ink, optical properties of paper with fluorescent additives , the internal lateral spread of light in paper with fluorescent additives and the fluorescent Clapper-Yule spectral reflectance prediction model, we introduce two factor parameters which are the initial thickness of the inks and the factor of ink thickness variation. A model for deducing ink thickness variations of printing on the fluorescent substrate is developed by the least square method and the spectrum reflectance of prints which measures the ink thickness variations. The correctness of the conclusions are verified by experiment.

  5. Deducing fast electron density changes in randomly orientated uncrystallized biomolecules in a pump–probe experiment

    PubMed Central

    Pande, K.; Schwander, P.; Schmidt, M.; Saldin, D. K.

    2014-01-01

    We propose a method for deducing time-resolved structural changes in uncrystallized biomolecules in solution. The method relies on measuring the angular correlations of the intensities, when averaged over a large number of diffraction patterns from randomly oriented biomolecules in solution in a liquid solvent. The experiment is somewhat like a pump–probe version of an experiment on small angle X-ray scattering, except that the data expected by the algorithm are not just the radial variation of the averaged intensities. The differences of these correlation functions as measured from a photoexcited and dark structure enable the direct calculation of the difference electron density with a knowledge of only the dark structure. We exploit a linear relation we derive between the difference in these correlation functions and the difference electron density, applicable for small structural changes. PMID:24914159

  6. The work function of n-ZnO deduced from heterojunctions with Si prepared by ALD

    NASA Astrophysics Data System (ADS)

    Quemener, V.; Alnes, M.; Vines, L.; Rauwel, P.; Nilsen, O.; Fjellvåg, H.; Monakhov, E. V.; Svensson, B. G.

    2012-08-01

    Highly doped n-type ZnO films have been grown on n-type and p-type Si substrates by atomic layer deposition (ALD). Transmission electron microscopy shows columnar growth of the ZnO films with randomly oriented grains and a very thin interfacial layer of SiOx(x ⩽ 2) with a thickness below 0.4 nm to the Si substrate. Current-voltage and capacitance-voltage measurements performed at temperatures from 50 to 300 K reveal a strong rectifying behaviour on both types of substrates with an ideality factor close to unity between 180 and 280 K. Using the classical approach of thermionic emission, the barrier heights of the ZnO/n-Si and ZnO/p-Si junctions have been deduced and consistent values are obtained yielding a work function of n-type ZnO close to 4.65 eV.

  7. 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.

  8. Deducing fast electron density changes in randomly orientated uncrystallized biomolecules in a pump-probe experiment.

    PubMed

    Pande, K; Schwander, P; Schmidt, M; Saldin, D K

    2014-07-17

    We propose a method for deducing time-resolved structural changes in uncrystallized biomolecules in solution. The method relies on measuring the angular correlations of the intensities, when averaged over a large number of diffraction patterns from randomly oriented biomolecules in solution in a liquid solvent. The experiment is somewhat like a pump-probe version of an experiment on small angle X-ray scattering, except that the data expected by the algorithm are not just the radial variation of the averaged intensities. The differences of these correlation functions as measured from a photoexcited and dark structure enable the direct calculation of the difference electron density with a knowledge of only the dark structure. We exploit a linear relation we derive between the difference in these correlation functions and the difference electron density, applicable for small structural changes. PMID:24914159

  9. 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

  10. 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.

  11. 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

  12. Oxygen plasma flow properties deduced from laser-induced fluorescence and probe measurements.

    PubMed

    Löhle, Stefan; Eichhorn, Christoph; Steinbeck, Andreas; Lein, Sebastian; Herdrich, Georg; Röser, Hans-Peter; Auweter-Kurtz, Monika

    2008-04-10

    Estimation of the local dissociation degree and the local mass-specific enthalpy of a pure oxygen plasma flow determined mainly from laser-induced fluorescence measurements are reported. Measurements have been conducted for several generator parameters in an inductively heated plasma wind tunnel. Additional probe measurements of total pressure together with the deduced translational temperature are used to estimate the local mass-specific enthalpy. For a reference condition, full dissociation has been measured. The measured translational temperature of atomic oxygen for this condition is T = 3500 K. Subsequently, the local mass-specific enthalpy has been derived using these local density and temperature measurements. For the reference condition the estimated value of h = 27 MJ/kg is in good agreement with the probe measurements and results from diode laser absorption spectroscopy. PMID:18404183

  13. Fission fragment mass yield deduced from density distribution in the pre-scission configuration

    NASA Astrophysics Data System (ADS)

    Warda, M.; Zdeb, A.

    2015-11-01

    Static self-consistent methods usually allow one to determine the most probable fission fragments mass asymmetry. We have applied random neck rupture mechanism to the nuclei in the configuration at the end of fission paths. Fission fragment mass distributions have been deduced from the pre-scission nuclear density distribution obtained from the self-consistent calculations. Potential energy surfaces as well as nuclear shapes have been calculated in the fully microscopic theory, namely the constrained Hartree-Fock-Bogoliubov model with the effective Gogny D1S density-dependent interaction. The method has been applied for analysis of fission of {}{256,258}Fm, 252Cf and 180Hg and compared with the experimental data.

  14. A major protein precursor of zebra mussel (Dreissena polymorpha) byssus: deduced sequence and significance.

    PubMed

    Anderson, K E; Waite, J H

    1998-04-01

    The zebra mussel is a nonindigenous invader of North American lakes and rivers and one of the few freshwater bivalve molluscs having a byssus--a sclerotized organ used by the mussel for opportunistic attachment to hard surfaces. We have sequenced a foot-specific cDNA whose composite protein sequence was deduced from a series of overlapping but occasionally nonidentical cDNA fragments. The overall deduced sequence matches tryptic peptides from a major byssal precursor protein--Dreissena polymorpha foot protein 1 (Dpfp1). The calculated mass of Dpfp1 is 49 kDa; but this is known to be extensively hydroxylated and O-glycosylated during maturation. Purified native Dpfp1 analyzed using matrix-assisted laser-desorption ionization mass spectrometry with time-of-flight indicates that the protein occurs as at least two size variants with masses of 48.6 and 54.5 kDa. In all probability, the sequence variants reported in this study are related to the larger mass variant. Dpfp1 has a block copolymer-like structure defined by two consensus motifs that are sharply segregated into domains. The N-terminal side of Dpfp1 has 22 tandem repeats of a heptapeptide consensus (P-[V/E]-Y-P-[T/S/delta]-[K/Q]-X); the C-terminal side has 16 repeats of a tridecapeptide motif (K-P-G-P-Y-D-Y-D-G-P-Y-D-K). Both consensus repeats are unique, with some limited homology to other proteins functioning in tension: marine mussel adhesives, plant extensins, titin, and trematode eggshell precursors. PMID:9604314

  15. Latitudinal distribution of solar wind as deduced from Lyman alpha measurements - an improved method

    NASA Astrophysics Data System (ADS)

    Summanen, T.; Lallement, R.; Bertaux, J. L.; Kyrola, E.

    1993-08-01

    In this work we examine the possibility of deducing the latitudinal distribution of the solar ionization rate using Prognoz 6 Lyman-alpha data in a more general and flexible way than previously examined. Using a so-called hot model for the hydrogen distribution and the optically thin model for the resonance scattering, theoretical Lyman-alpha intensity for the interstellar hydrogen is calculated and compared with the intensity data measured by Prognoz 6. Varying the latitudinal dependence of the ionization rate, the distributions which produce the best fit with the data are analyzed for four different measuring sessions. As a result, we get four ionization rate distributions that have two common features. The ionization rate is enhanced near the solar equator, and large broad plateaus exist around heliographic latitudes +/- 30 to +/- 70 deg. The latitudinal distribution of the average ionization rate about the solar minimum deviates clearly from the spherically symmetric and sinusoidally with the latitude-varying models used so far. The growth of the solar wind mass flux from the solar polar areas toward the equator corresponds to the earlier results found from Lyman-alpha measurements.

  16. 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.

  17. Using Bayesian Evidence to Deduce the Dust-Attenuation Law at High Redshift

    NASA Astrophysics Data System (ADS)

    Salmon, Brett W.; Papovich, Casey J.; Finkelstein, Steven L.; Closson Ferguson, Henry; Long, James; CANDELS

    2016-01-01

    Although the nature of dust attenuation affects nearly all aspects of galaxy evolution, very little is known about the form of the dust-attenuation law in the distant Universe. Dust enshrouds and obscures UV star formation, convoluting our understanding of galaxy evolution at high redshift. Recent literature has recognized how the inferred physical properties of distant galaxies can be influenced by the non-universality of their attenuation curve shape. In this talk, I will present a Bayesian method to quantitatively constrain the dust-attenuation curve in high-redshift star-forming galaxies. This method is tested on galaxies at z~2 where we have CANDELS UV-to-optical photometry and Spitzer/Herschel IR luminosities. We find that the dust law implied from using only UV/optical data to calculate the full posterior probability densities supports the observed IR luminosities as predicted by that dust law. This method shows promise to deduce the shape of the attenuation curve at higher redshifts (z>4), as supported by our experiments using mock data from a semi-analytic model with qualities like those of the CANDELS GOODS fields.

  18. 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.

  19. 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}.

  20. Relations between Aliphatics and Silicate Components in 12 Stratospheric Particles Deduced from Vibrational Spectroscopy

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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 CH2/CH3 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.

  1. 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}.

  2. 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.

  3. 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.

  4. 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.

  5. Epitopes of human testis-specific lactate dehydrogenase deduced from a cDNA sequence

    SciTech Connect

    Millan, J.L.; Driscoll, C.E.; LeVan, K.M.; Goldberg, E.

    1987-08-01

    The sequence and structure of human testis-specific L-lactate dehydrogenase (LDHC/sub 4/, LDHX; (L)-lactate:NAD/sup +/ oxidoreductase, EC 1.1.1.27) has been derived from analysis of a complementary DNA (cDNA) clone comprising the complete protein coding region of the enzyme. From the deduced amino acid sequence, human LDHC/sub 4/ is as different from rodent LDHC/sub 4/ (73% homology) as it is from human LDHA/sub 4/ (76% homology) and porcine LDHB/sub 4/ (68% homology). Subunit homologies are consistent with the conclusion that the LDHC gene arose by at least two independent duplication events. Furthermore, the lower degree of homology between mouse and human LDHC/sub 4/ and the appearance of this isozyme late in evolution suggests a higher rate of mutation in the mammalian LDHC genes than in the LDHA and -B genes. Comparison of exposed amino acid residues of discrete anti-genic determinants of mouse and human LDHC/sub 4/ reveals significant differences. Knowledge of the human LDHC/sub 4/ sequence will help design human-specific peptides useful in the development of a contraceptive vaccine.

  6. 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).

  7. Rates of intra- and intermolecular electron transfers in hydrogenase deduced from steady-state activity measurements.

    PubMed

    Dementin, Sébastien; Burlat, Bénédicte; Fourmond, Vincent; Leroux, Fanny; Liebgott, Pierre-Pol; Abou Hamdan, Abbas; Léger, Christophe; Rousset, Marc; Guigliarelli, Bruno; Bertrand, Patrick

    2011-07-01

    Electrons are transferred over long distances along chains of FeS clusters in hydrogenases, mitochondrial complexes, and many other respiratory enzymes. It is usually presumed that electron transfer is fast in these systems, despite the fact that there has been no direct measurement of rates of FeS-to-FeS electron transfer in any respiratory enzyme. In this context, we propose and apply to NiFe hydrogenase an original strategy that consists of quantitatively interpreting the variations of steady-state activity that result from changing the nature of the FeS clusters which connect the active site to the redox partner, and/or the nature of the redox partner. Rates of intra- and intermolecular electron transfer are deduced from such large data sets. The mutation-induced variations of electron transfer rates cannot be explained by changes in intercenter distances and reduction potentials. This establishes that FeS-to-FeS rate constants are extremely sensitive to the nature and coordination of the centers. PMID:21615141

  8. Creep Along the North Anatolian Fault at Ismetpasa (Western Turkey) Deduced From InSAR

    NASA Astrophysics Data System (ADS)

    Cakir, Z.; Ergintav, S.; Akoglu, A. M.; Belabbes, S.; Meghraoui, M.

    2004-12-01

    Although creeping along the North Anatolian Fault (NAF) at Ismetpasa (Turkey) was discovered some thirty years ago, about a decade after the first observation of the phenomenon along the San Andreas Fault in California, little is known about its extent and rate. In order to reveal its three dimensional nature and rupture characteristics, we use Synthetic Aperture Radar Interferometry (InSAR) and dislocations on rectangular faults in elastic half space. Interferograms with temporal baselines ranging between 1.25 and 5 years show that creeping starts at the western termination of the 1943 (Mw=7.6) earthquake rupture and continues about 70-km to the west overlapping with the eastern part of the 185-km-long rupture of the 1944 (Mw=7.3) earthquake. Maximum creep rate is 10 mm/year approximately in the mid point of the creeping part of the rupture segment diminishing gradually towards the edges. Near Ismetpasa, InSAR data yield 7.7 mm/year of creep rate, consistent with those deduced from instrumental (triangulation and creepmeters) measurements (i.e. 9 mm/year). Modeling of the InSAR and GPS data suggests that the fault creep occurs most probably at a shallow depth (0-7 km). InSAR data do not support the previous claims of creep events triggered by the 1999 Izmit earthquake.

  9. Possibility to Deduce the Emission Time Sequence of Neutrons and Protons from the Neutron-Proton Correlation Function

    SciTech Connect

    Ghetti, R.; Helgesson, J.; Colonna, N.; Jakobsson, B.; Anzalone, A.; Bellini, V.; Carlen, L.; Cavallaro, S.; Celano, L.; De Filippo, E.

    2001-09-03

    Experimental information has been derived from the neutron-proton correlation function in order to deduce the time sequence of neutrons and protons emitted at 45{sup o} in the E/A=45 MeV {sup 58}Ni+{sup 27}Al reaction.

  10. Zonal currents in the F region deduced from Swarm constellation measurements

    NASA Astrophysics Data System (ADS)

    Lühr, Hermann; Kervalishvili, Guram; Rauberg, Jan; Stolle, Claudia

    2016-01-01

    The Swarm constellation has been used to estimate zonal currents in the topside F region ionosphere at about 500 km. Near-simultaneous magnetic field measurements from two altitudes but the same meridian are used for the current density calculations. We consider the period 15 February to 23 June 2014 for deriving a full 24 h local time coverage of the latitudinal distribution over ±50° in magnetic latitude. Intervals with close orbital phasing at the two heights are considered, which repeat every 6 days. From such days seven successive orbits are used where the epochs of equator crossings differ by less than 2 min. Deduced current densities are predominantly eastward (about 20 nA/m2) on the dayside and westward (about 10 nA/m2) on the nightside. A number of different drivers contribute to the observed total current. We identified the gravity-driven eastward current as the most prominent at low latitudes. Eastward currents in the Northern Hemisphere are clearly stronger than in the south. This is attributed to the proximity of our study period to June solstice, when the solar radiation is stronger in the north. In addition, interhemispheric winds from the Northern (summer) to the Southern (winter) Hemisphere contribute. They cause eastward currents in the north and westward in the south. We find a relatively large variability of the zonal currents both in space and time. The standard deviation is at least twice as large as the mean value of current density. This large variability is suggested to be related to gravity wave forcing from below.

  11. The radiation budget of a Cirrus layer deduced from simultaneous aircraft observations and model calculations

    NASA Technical Reports Server (NTRS)

    Ackerman, Thomas P.; Kinne, Stefan A.; Heymsfield, Andrew J.; Valero, Francisco P. J.

    1990-01-01

    Several aircraft were employed during the FIRE Cirrus IFO in order to make nearly simultaneous observations of cloud properties and fluxes. A segment of the flight data collected on 28 October 1988 during which the NASA Ames ER-2 overflew the NCAR King Air was analyzed. The ER-2 flew at high altitude making observations of visible and infrared radiances and infrared flux and cloud height and thickness. During this segment, the King Air flew just above the cloud base making observations of ice crystal size and shape, local meteorological variables, and infrared fluxes. While the two aircraft did not collect data exactly coincident in space and time, they did make observations within a few minutes of each other. For this case study, the infrared radiation balance of the cirrus layer is of primary concern. Observations of the upwelling 10 micron radiance, made from the ER-2, can be used to deduce the 10 micron optical depth of the layer. The upwelling broadband infrared flux is also measured from the ER-2. At the same time, the upwelling and downwelling infrared flux at the cloud base is obtained from the King Air measurements. Information on cloud microphysics is also available from the King Air. Using this data in conjunction with atmospheric temperature and humidity profiles from local radiosondes, the necessary inputs for an infrared radiative transfer model can be developed. Infrared radiative transfer calculations are performed with a multispectral two-stream model. The model fluxes at the cloud base and at 19 km are then compared with the aircraft observations to determine whether the model is performing well. Cloud layer heating rates can then be computed from the radiation exchange.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. Traveling Wave Packets of Total Electron Content Disturbances As Deduced From Global GPS Network Data

    NASA Astrophysics Data System (ADS)

    Afraimovich, E.; Lesyuta, O.; Lipko, Yu.; Perevalova, N.; Voyeikov, S.; Vodyannikov, V.; Yakovets, A.; Jacobi, Ch.

    This report discusses the experimental research results on the morphology and physi- cal origin of total electron content (TEC) pulsations as measured using the data from the global GPS network. Periodic electron density oscillations of the type of wave packets were investigated previously in terms of the hypothesis of their association with geomagnetic field (GP) pulsations. The greater part of evidence of the association between GP ad periodic electron density oscillations in the ionosphere was obtained by recording the frequency Doppler shift if the ionosphere-reflected radio signal and TEC variations measured using signals from geostationary satellites. However, many years of investigations have not yet provided thorough insight into the mechanisms ac- counting for the linkage between GP and ionospheric variations. One reason for that is the difficulty associated with obtaining statistically significant sets of experimental data. The use of the international ground-based network of two-frequency receivers of the navigation GPS system which comprised no less than 900 site as of August 2001 and is currently placing the data on the Internet, opens up a new era of a global, con- tinuous and fully computerized monitoring of ionospheric disturbances of a different class. This report presents a global morphology of TEC pulsations for 50 days with a different level of geomagnetic activity and the number of stations of the global GPS network from 100 to 300. A total number of the "receiver - GPS satellites" radio paths used in the analysis is about 500,000. Quasi-periodic TEC variations in the range of periods from 10 to 20 min are investigated, which is dictated by the fact that the data from the global GPS network are placed on the Internet with a standard temporal res- olution of 30 s. Most often, the observed TEC pulsations represent wave packets with a duration on the order of 1 hour. It was found that such TEC pulsations are a rela- tively rare event and are

  17. 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

  18. Inflow direction of interstellar neutrals deduced from pickup ion measurements at 1 AU

    NASA Astrophysics Data System (ADS)

    Drews, Christian; Berger, Lars; Wimmer-Schweingruber, Robert F.; Bochsler, Peter; Galvin, Antoinette B.; Klecker, Berndt; Möbius, Eberhard

    2012-09-01

    Observations of interstellar pickup ions inside the heliosphere provide an indirect method to access information on the surrounding interstellar medium. The so-called pickup ion focusing cone and pickup ion crescent, which show an imprint of the related longitudinal distribution of interstellar neutrals in form of two overabundances on the down- and upwind side of the sun, are both believed to be aligned along the inflow vector of the interstellar medium. By finding their longitudinal positions, we can give an accurate value for the inflow direction λISM of interstellar matter. For that we performed an epoch analysis of interstellar pickup ions measured by the PLAsma and SupraThermal Ion Composition instrument (PLASTIC) on the Solar TErrestrial RElations Observatory mission (STEREO) and were able to reveal in situ the longitudinal distribution of interstellar He+, O+, and Ne+ pickup ions in the ecliptic plane at 1 AU. The previously accepted values for the inflow direction of interstellar matter in ecliptic longitude, as obtained with Ulysses/GAS (λ = 75.4° ± 0.5°), Prognoz 6 (λ = 74.5° ± 1°), and ACE/SWICS (λ = 74.43° ± 0.33°), are currently debated, especially in view of recent results from the Interstellar Boundary Explorer (IBEX) mission that show an inflow direction of interstellar neutral helium of λ = 79° + 3.0°(-3.5°). Four years of data collected with PLASTIC aboard STEREO A provided statistics sufficient not only to obtain values for the inflow direction of interstellar helium (λCone = 77.4° ± 1.9° and λCrescent = 80.4° ± 5.4°, deduced from an analysis of the He+ focusing cone and crescent, respectively) but also to derive values for the inflow direction of interstellar neon (λCone = 77.4° ± 5.0° and λCrescent = 79.7° ± 2.6°) and oxygen (λCrescent = 78.9° ± 3.1°). Although our values for He+, O+, and Ne+ are consistent with results from ACE, Ulysses, and Prognoz 6, considering the statistical and systematic

  19. The residual interaction of bound nucleons-two-nucleon matrix elements deduced from transfer experiments

    NASA Astrophysics Data System (ADS)

    Daehnick, W. W.

    1983-07-01

    Matrix elements for the effective two-nucleon interaction have been deduced from the population of multiplets near closed shells as observed in direct transfer reactions. In the evaluation, the limited purity of such multiples was taken into consideration, typically by weighting the observed fractions of the two-nucleon configurations by their spectroscopic strenghts and by using the resulting energy centroids. In a few cases, off-diagonal matrix elements are available from empirical wave funcitons. The systematic errors for particle-particle matrix elements extracted directly and those obtained from Pandya transformations were found to go in opposite directions. In some cases, this feautre of the empirical mehtod could be used to suggest upper and lower “bounds” for the extracted matrix elements. Diagonal matrix elements for the empirical residual interaction show a number of features suggestive of an underlying simplicity in the interaction of bound nucleons. Within experimental uncertainties (of about 10% for T=0 matrix elements) the monopole parts of the matrix elements are fit well with a simple A-0.75 dependence, and the data available to date do not reveal any significant monopole dependence on the quantum numbers of the interacting nucleons. The usefulness of scaling is suggested. Generally, diagonal matrix elements EJ( j1, j2) normalized by the extracted A-dependent monopole strength agree within expected experimental uncertainties whether derived from particle-particle or particle-hole multiples and whether extracted from the beginning or the end of a major shell. For values J≠0, the diagonal EJ( j2) matrix elements seem to follow two universal functions which depend on the semi-classical coupling angles θ 12, but are otherwise independent on j. For j1≠ j2 several “typical” functions ƒ(θ 12) can be constructed which fit subsets of the data and differ in a predictable way. The general features of the bound-nucleon interaction appear

  20. Tropospheric CO vertical profiles deduced from total columns using data assimilation: methodology and validation

    NASA Astrophysics Data System (ADS)

    El Amraoui, L.; Attié, J.-L.; Ricaud, P.; Lahoz, W. A.; Piacentini, A.; Peuch, V.-H.; Warner, J. X.; Abida, R.; Barré, J.

    2013-07-01

    This paper presents a validation of a method to derive the vertical profile of carbon monoxide (CO) from its total column using data assimilation. The main motivation of this study is twofold. First, to deduce both the vertical CO profiles and the assimilated CO fields with good confidence. Second, for chemical species that can be measured only as the total column, this method provides an attractive alternative for estimating their vertical profiles in the troposphere. We choose version 3 (V3) of MOPITT CO total columns to validate the proposed method. MOPITT has the advantage of providing both the vertical profiles and the total columns of CO. Furthermore, this version has been extensively validated by comparison with many independent datasets, and has been used in many scientific studies. The first step of the paper consists in the specification of the observation errors based on the Chi-square (χ2) test. The observations have been binned according to day, night, land and sea (LAND_DAY, LAND_NIGHT and SEA, respectively). The respective optimal observation error values for which the χ2 metric is the closest to 1 are: 7%, 8% and 11% for SEA, LAND_DAY and LAND_NIGHT, respectively. In a second step, the CO total column, with its specified errors, is used within the assimilation system to estimate the vertical profiles. These are validated by comparison with vertical profiles of MOPITT V3 retrievals at global and regional scales. Generally, both datasets show similar patterns and good agreement at both global and regional scales. Nevertheless, the total column analyses (TOTCOL_ANALYSES) slightly overestimate CO concentrations compared to MOPITT observations. In a third step, vertical profiles calculated from TOTCOL_ANALYSES have been compared to those calculated from the assimilation of MOPITT V3 vertical profiles (PROFILE_ANALYSES). Both datasets shows very good agreement, but TOTCOL_ANALYSES tend to slightly overestimate CO concentrations. The mean bias between

  1. The Stress Field of Eastern Africa Deduced From new Focal Mechanisms

    NASA Astrophysics Data System (ADS)

    Barth, A.; Wenzel, F.

    2006-12-01

    The East African Rift intersects the African continent from North to South for over 3000~km. Especially for regions neighbouring the rift only limited information on the stress regime is available. This is primarily due to a lack of earthquake source mechanism information, from which stress orientations can be deduced. Most of strong earthquakes occur within the rift zone, so that for these events focal mechanisms are calculated routinely by the Harvard CMT-group by moment tensor inversion using teleseismic data. However, apart from the rift earthquake magnitudes are often below their threshold of MW ~5.0 and thus CMT-solutions are hardly available. We developed a semi-automatic and frequency sensitive moment tensor inversion that allows us to determine source mechanisms of these light to moderate magnitude events. We present focal mechanism of 40 earthquakes with magnitudes ranging between 4.4~≤ MW ≤~5.4 taken from the years 1995-2002 that were not studied previously. We invert data from permanent recording seismometers with source-receiver distances up to 3000 km within variable frequency bands between 13 mHz and 29 mHz. For the formal stress inversion we use these new results, all 90 CMT-solutions available for Eastern Africa (1977-2005) and 17 focal mechanisms determined by moment tensor inversion from other authors. Finally, we divide Eastern Africa into 11 regions, binning the earthquake source mechanisms to perform the stress inversion. To analyse the dependence of the resulting stress tensors on the binning, we change regional partitioning systematically. We obtain stable stress tensors that show extensional regimes all over Eastern Africa with the maximum horizontal stress SH orientated in North-South direction. Beside this, we observe variations of SH in the vicinity of the Eastern rift branch (Kenya-Rift) towards Lake Victoria, where SH is rotated nearly perpendicular to the rift orientation. Moreover in the high plateau region West of Lake Malawi

  2. Inflow Direction of Interstellar Neutrals deduced from Pickup Ion Measurements at 1 AU

    NASA Astrophysics Data System (ADS)

    Drews, C.; Berger, L.; Wimmer-Schweingruber, R. F.

    2012-04-01

    The, so called, interstellar pickup ions are born from ionization of the interstellar neutral background gas by solar UV radiation or charge exchange with solar wind protons. The low speed of these interstellar particles in respect to the solar wind, forces them - after ionization - on circular orbits around the magnetic field, which is embedded into the solar wind. As a result, interstellar pickup ions show very characteristic velocity spectra with a sharp cut-off at 2·vSW, once they have been picked up by the solar wind. Furthermore, the influence by the Sun's gravitational force and UV radiation results in a very characteristic angular distribution in the eclitpic plane featuring two distinct structures, that are both believed to be aligned along the inflow direction of interstellar matter. Here we present recent observations of interstellar pickup ions with the Plasma and Suprathermal Ion Composition instrument (PLASTIC) mounted on the Solar TErrestrial RElations Observatory A (STEREO A). PLASTIC is a time-of-flight mass spectrometer, that determines the velocity, mass and charge of incoming ions by measuring their energy-per-charge, total energy and time-of-flight. STEREO PLASTIC's big geometric factor and the unusual prolonged solar minimum allows for the first time investigation of heavy pickup ions with unprecedented quality. Within the framework of our analysis we have performed a superposed epoch analysis of four consecutive STEREO A orbits that allowed us to reveal in-situ the angular distribution of He+ as well as heavy pickup ions (O+ and Ne+) at 1 AU. By analysing the interstellar features, namely the interstellar focusing cone and crescent, of the He+, O+ and Ne+ signature, we were able to estimate the inflow direction of interstellar helium as well as interstellar oxygen and neon. Our measurments revealed an inflow direction of λHe+ = 77.37°, λO+ = 78.42°, and λNe+ = 77.44°, which deviates from previously published results, deduced from the

  3. Incorporation of single dinitrophenyl-modified proteins in to the 30S subunit of Escherichia coli ribosomes by total reconstitution for localization by immune electron microscopy

    SciTech Connect

    Olah, T.V.

    1989-01-01

    The ribosome is a structurally defined organelle whose function is central to the existence of all organisms. It is the unique site of protein biosynthesis in all cells. A detailed understanding of ribosome structure is essential in understanding the process of translation. This thesis represents a new approach to the systematic localization of individual proteins contained in the small subunit of Escherichia coli ribosomes using immunoelectron microscopy. All 30S proteins were purified using high performance liquid chromatography (HPLC) and eight isolated proteins (S12,S21,S14,S19,S18,S17,S16 and S13) were derivatized with 2,4-(3,5-{sup 3}H)dinitrofluorobenzene (DNFB). The extent of modification of these proteins was estimated by both radioactivity and integrated peak areas, using dual wavelength monitoring at 214nm to detect protein and 360nm (to detect dinitrophenyl groups). Each dinitrophenylated protein was introduced in place of the corresponding unmodified protein into totally reconstituted 30S subunits. Antibodies raised against the DNP-hapten bound effectively to such reconstituted subunits and did not cause dissociation of the modified protein from the subunit. Electron microscopy of the immune complexes was used to localize the modified protein on the subunit surface. Incorporation of any of the DNP-modified proteins, with the exception of DNP-S18, does not interfere with the functionality of the ribosome as measure by the binding of Phe-tRNA{sup Phe} or the synthesis of poly(Phe) in a poly(U)-dependent manner. Results show that unmodified protein competes with DNP-protein and that DNP-protein can function, as its native counterpart, in stimulating uptake of specific proteins during reconstitution. This data provides evidence that each DNP-protein occupies the same position in 30S subunits as does the corresponding unmodified protein.

  4. DEDUCE Clinical Text: An Ontology-based Module to Support Self-Service Clinical Notes Exploration and Cohort Development.

    PubMed

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

    2013-01-01

    Large amounts of information, as well as opportunities for informing research, education, and operations, are contained within clinical text such as radiology reports and pathology reports. However, this content is less accessible and harder to leverage than structured, discrete data. We report on an extension to the Duke Enterprise Data Unified Content Explorer (DEDUCE), a self-service query tool developed to provide clinicians and researchers with access to data within the Duke Medicine Enterprise Data Warehouse (EDW). The DEDUCE Clinical Text module supports ontology-based text searching, enhanced filtering capabilities based on document attributes, and integration of clinical text with structured data and cohort development. The module is implemented with open-source tools extensible to other institutions, including a Java-based search engine (Apache Solr) with complementary full-text indexing library (Lucene) employed with a negation engine (NegEx) modified by clinical users to include to local domain-specific negation phrases. PMID:24303270

  5. Lu Hf and Ar Ar chronometry supports extreme rate of subduction zone metamorphism deduced from geospeedometry

    NASA Astrophysics Data System (ADS)

    Philippot, Pascal; Blichert-Toft, Janne; Perchuk, Alexei; Costa, Sylvie; Gerasimov, Vladimir

    2001-12-01

    temperatures are equivalent to or in the upper range of peak metamorphic temperatures. With respect to Ar, calculated closure temperatures of 570 °C for the Yukon eclogites and 560-600 °C for the Great Caucasus eclogites are within error of the temperatures of the early stage of cooling and/or exhumation. These results indicate that the eclogitic rocks experienced a minimum cooling and exhumation of about 150 °C and 25 km in a time interval smaller than the errors on the ages. The fact that garnet and phengite yield indistinguishable Lu-Hf and Ar-Ar ages is in good agreement with the observation deduced from geospeedometry that the time elapsed at eclogitic conditions should be extremely short (of the order of 1 Ma). Considering the exceptional precision of the age information obtained on eclogitic garnet using the Lu-Hf technique and that Lu-Hf, Ar-Ar and geospeedometry approaches were carried out the same samples, these results suggest that the time-scale resolution required for unraveling rates of high-pressure metamorphism remains out of reach of current thermochronological methods.

  6. The antibiotic Furvina® targets the P-site of 30S ribosomal subunits and inhibits translation initiation displaying start codon bias

    PubMed Central

    Fabbretti, Attilio; Brandi, Letizia; Petrelli, Dezemona; Pon, Cynthia L.; Castañedo, Nilo R.; Medina, Ricardo; Gualerzi, Claudio O.

    2012-01-01

    Furvina®, also denominated G1 (MW 297), is a synthetic nitrovinylfuran [2-bromo-5-(2-bromo-2-nitrovinyl)-furan] antibiotic with a broad antimicrobial spectrum. An ointment (Dermofural®) containing G1 as the only active principle is currently marketed in Cuba and successfully used to treat dermatological infections. Here we describe the molecular target and mechanism of action of G1 in bacteria and demonstrate that in vivo G1 preferentially inhibits protein synthesis over RNA, DNA and cell wall synthesis. Furthermore, we demonstrate that G1 targets the small ribosomal subunit, binds at or near the P-decoding site and inhibits its function interfering with the ribosomal binding of fMet-tRNA during 30S initiation complex (IC) formation ultimately inhibiting translation. Notably, this G1 inhibition displays a bias for the nature (purine vs. pyrimidine) of the 3′-base of the codon, occurring efficiently only when the mRNA directing 30S IC formation and translation contains the canonical AUG initiation triplet or the rarely found AUA triplet, but hardly occurs when the mRNA start codon is either one of the non-canonical triplets AUU or AUC. This codon discrimination by G1 is reminiscent, though of opposite type of that displayed by IF3 in its fidelity function, and remarkably does not occur in the absence of this factor. PMID:22941660

  7. The antibiotic Furvina® targets the P-site of 30S ribosomal subunits and inhibits translation initiation displaying start codon bias.

    PubMed

    Fabbretti, Attilio; Brandi, Letizia; Petrelli, Dezemona; Pon, Cynthia L; Castañedo, Nilo R; Medina, Ricardo; Gualerzi, Claudio O

    2012-11-01

    Furvina®, also denominated G1 (MW 297), is a synthetic nitrovinylfuran [2-bromo-5-(2-bromo-2-nitrovinyl)-furan] antibiotic with a broad antimicrobial spectrum. An ointment (Dermofural®) containing G1 as the only active principle is currently marketed in Cuba and successfully used to treat dermatological infections. Here we describe the molecular target and mechanism of action of G1 in bacteria and demonstrate that in vivo G1 preferentially inhibits protein synthesis over RNA, DNA and cell wall synthesis. Furthermore, we demonstrate that G1 targets the small ribosomal subunit, binds at or near the P-decoding site and inhibits its function interfering with the ribosomal binding of fMet-tRNA during 30S initiation complex (IC) formation ultimately inhibiting translation. Notably, this G1 inhibition displays a bias for the nature (purine vs. pyrimidine) of the 3'-base of the codon, occurring efficiently only when the mRNA directing 30S IC formation and translation contains the canonical AUG initiation triplet or the rarely found AUA triplet, but hardly occurs when the mRNA start codon is either one of the non-canonical triplets AUU or AUC. This codon discrimination by G1 is reminiscent, though of opposite type of that displayed by IF3 in its fidelity function, and remarkably does not occur in the absence of this factor. PMID:22941660

  8. 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.

  9. Amino-terminal amino acid sequence of the major structural polypeptides of avian retroviruses: sequence homology between reticuloendotheliosis virus p30 and p30s of mammalian retroviruses.

    PubMed Central

    Hunter, E; Bhown, A S; Bennett, J C

    1978-01-01

    The major structural polypeptides, p30 of reticuloendotheliosis virus (REV) (strain T) and p27 of avian sarcoma virus B77, have been compared with regard to amino acid composition. NH2-terminal amino acid sequence, and immunological crossreactions. The amino acid composition of the two polypeptides is distinct, and a comparison of the first 30 NH2-terminal amino acids of REV p30 with that for the first 25 of B77 p27 yields only three homologous residues. In competition radioimmunoassays the polypeptides show no crossreactivity. A comparison of the amino acid composition and NH2-terminal amino acid sequence of REV p30 with those reported for several mammalian retrovirus p30s shows remarkable similarities. Both REV and mammalian p30s contain a large number of polar residues in their amino acid composition and show approximately 40% homology in the first 30 NH2-terminal amino acids. No crossreactivity could be observed, however, in competition radioimmunoassays between Rauscher murine leukemia virus p30 and that of REV. The observations reported here suggest a close evolutionary relationship between REV and the mammalian retroviruses. Images PMID:208072

  10. 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

  11. 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

  12. Serial femtosecond X-ray diffraction of 30S ribosomal subunit microcrystals in liquid suspension at ambient temperature using an X-ray free-electron laser

    PubMed Central

    Demirci, Hasan; Sierra, Raymond G.; Laksmono, Hartawan; Shoeman, Robert L.; Botha, Sabine; Barends, Thomas R. M.; Nass, Karol; Schlichting, Ilme; Doak, R. Bruce; Gati, Cornelius; Williams, Garth J.; Boutet, Sébastien; Messerschmidt, Marc; Jogl, Gerwald; Dahlberg, Albert E.; Gregory, Steven T.; Bogan, Michael J.

    2013-01-01

    High-resolution ribosome structures determined by X-ray crystallography have provided important insights into the mechanism of translation. Such studies have thus far relied on large ribosome crystals kept at cryogenic temperatures to reduce radiation damage. Here, the application of serial femtosecond X-ray crystallography (SFX) using an X-ray free-electron laser (XFEL) to obtain diffraction data from ribosome microcrystals in liquid suspension at ambient temperature is described. 30S ribosomal subunit microcrystals diffracted to beyond 6 Å resolution, demonstrating the feasibility of using SFX for ribosome structural studies. The ability to collect diffraction data at near-physiological temperatures promises to provide fundamental insights into the structural dynamics of the ribosome and its functional complexes. PMID:23989164

  13. 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.

  14. Physical and biochemical nature of the bacterial cytoplasm: movement and localization of mRNA and the 30S subunits of ribosomes.

    PubMed

    Trevors, J T

    2012-05-01

    There is a paucity of knowledge on how mRNA transcripts in the spatially crowded, but molecularly organized bacterial cytoplasm contact the 30S ribosomal subunits. Does simple diffusion in the cytoplasm account for transcript-ribosome interactions given that a large number of ribosomes (e.g., about 72,000 in Escherichia coli during exponential growth) can be present in the cytoplasm? Or are undiscovered mechanisms present where specific transcripts are directed to specific ribosomes at specific cytoplasmic locations, while others are mobilized in a random manner? Moreover, is it possible that cytoplasmic mobilization occurs in bacteria, driven possibly by thermal infrared (IR) radiation and the generation of exclusion zone (EZ) water? These aspects will be discussed in this article and hypotheses presented. PMID:22710107

  15. Deducing the electron-beam diameter in a laser-plasma accelerator using x-ray betatron radiation.

    PubMed

    Schnell, Michael; Sävert, Alexander; Landgraf, Björn; Reuter, Maria; Nicolai, Maria; Jäckel, Oliver; Peth, Christian; Thiele, Tobias; Jansen, Oliver; Pukhov, Alexander; Willi, Oswald; Kaluza, Malte C; Spielmann, Christian

    2012-02-17

    We investigate the properties of a laser-plasma electron accelerator as a bright source of keV x-ray radiation. During the interaction, the electrons undergo betatron oscillations and from the carefully measured x-ray spectrum the oscillation amplitude of the electrons can be deduced which decreases with increasing electron energies. From the oscillation amplitude and the independently measured x-ray source size of (1.8±0.3) μm we are able to estimate the electron bunch diameter to be (1.6±0.3) μm. PMID:22401215

  16. Protein-RNA crosslinking in Escherichia coli 30S ribosomal subunits. Identification of a 16S rRNA fragment crosslinked to protein S12 by the use of the chemical crosslinking reagent 1-ethyl-3-dimethyl-aminopropylcarbodiimide.

    PubMed Central

    Chiaruttini, C; Expert-Bezançon, A; Hayes, D; Ehresmann, B

    1982-01-01

    1-ethyl-3-dimethyl aminopropylcarbodiimide (EDC) was used to cross-link 30S ribosomal proteins to 16S rRNA within the E. coli 3OS ribosomal subunit. Covalently linked complexes containing 30S proteins and 16S rRNA, isolated by sedimentation of dissociated crosslinked 30S subunits through SDS containing sucrose gradients, were digested with RNase T1, and the resulting oligonucleotide-protein complexes were fractionated on SDS containing polyacrylamide gels. Eluted complexes containing 30S proteins S9 and S12 linked to oligonucleotides were obtained in pure form. Oligonucleotide 5'terminal labelling was successful in the case of S12 containing but not of the S9 containing complex and led to identification of the S12 bound oligonucleotide as CAACUCG which is located at positions 1316-1322 in the 16S rRNA sequence. Protein S12 is crosslinked to the terminal G of this heptanucleotide. Images PMID:6760129

  17. Interconversion of active and inactive 30 S ribosomal subunits is accompanied by a conformational change in the decoding region of 16 S rRNA.

    PubMed

    Moazed, D; Van Stolk, B J; Douthwaite, S; Noller, H F

    1986-10-01

    Zamir, Elson and their co-workers have shown that 30 S ribosomal subunits are reversibly inactivated by depletion of monovalent or divalent cations. We have re-investigated the conformation of 16 S rRNA in the active and inactive forms of the 30 S subunit, using a strategy that is designed to eliminate reversible ion-dependent conformational effects that are unrelated to the heat-dependent Zamir-Elson transition. A combination of structure-specific chemical probes enables us to monitor the accessibility of pyrimidines at N-3 and purines at N-1 and N-7. Chemically modified bases are identified by end-labeling followed by analine-induced strand scission (in some cases preceded by hybrid selection), or by primer extension using synthetic DNA oligomers. These studies show the following: The transition from the active to the inactive state cannot be described as a simple loosening or unfolding of native structure, such as that which is observed under conditions of more severe ion depletion. Instead, it has the appearance of a reciprocal interconversion between two differently structured states; some bases become more reactive toward the probes, whilst others become less reactive as a result of inactivation. Changes in reactivity are almost exclusively confined to the "decoding site" centered at positions 1400 and 1500, but significant differences are also detected at U723 and G791 in the central domain. This may reflect possible structural and functional interactions between the central and 3' regions of 16 S rRNA. The inactive form also shows significantly decreased reactivity at positions 1533 to 1538 (the Shine-Dalgarno region), in agreement with earlier findings. The principal changes in reactivity involve the universally conserved nucleotides G926, C1395, A1398 and G1401. The three purines show reciprocal behavior at their N-1 versus N-7 positions. G926 loses its reactivity at N-1, but becomes highly reactive at N-7 as a result of the transition of the inactive

  18. Mutations in the leader region of ribosomal RNA operons cause structurally defective 30 S ribosomes as revealed by in vivo structural probing.

    PubMed

    Balzer, M; Wagner, R

    1998-02-27

    The biogenesis of functional ribosomes is regulated in a very complex manner, involving different proteins and RNA molecules. RNAs are not only essential components of both ribosomal subunits but also transiently interacting factors during particle formation. In eukaryotes snoRNAs act as molecular chaperones to assist maturation, modification and assembly. In a very similar way highly conserved leader sequences of bacterial rRNA operons are involved in the correct formation of 30 S ribosomal subunits. Certain mutations in the rRNA leader region cause severe growth defects due to malfunction of ribosomes which are assembled from such transcription units. To understand how the leader sequences act to facilitate the formation of the correct 30 S subunits we performed in vivo chemical probing to assess structural differences between ribosomes assembled either from rRNA transcribed from wild-type operons or from operons which contain mutations in the rRNA leader region. Cells transformed with plasmids containing the respective rRNA operons were reacted with dimethylsulphate (DMS). Ribosomes were isolated by sucrose gradient centrifugation and modified nucleotides within the 16 S rRNA were identified by primer extension reaction. Structural differences between ribosomes from wild-type and mutant rRNA operons occur in several clusters within the 16 S rRNA secondary structure. The most prominent differences are located in the central domain including the universally conserved pseudoknot structure which connects the 5', the central and the 3' domain of 16 S rRNA. Two other clusters with structural differences fall in the 5' domain where the leader had been shown to interact with mature 16 S rRNA and within the ribosomal protein S4 binding site. The other differences in structure are located in sites which are also known as sites for the action of several antibiotics. The data explain the functional defects of ribosomes from rRNA operons with leader mutations and help to

  19. 30S Subunit-Dependent Activation of the Sorangium cellulosum So ce56 Aminoglycoside Resistance-Conferring 16S rRNA Methyltransferase Kmr

    PubMed Central

    Savic, Miloje; Sunita, S.; Zelinskaya, Natalia; Desai, Pooja M.; Macmaster, Rachel; Vinal, Kellie

    2015-01-01

    Methylation of bacterial 16S rRNA within the ribosomal decoding center confers exceptionally high resistance to aminoglycoside antibiotics. This resistance mechanism is exploited by aminoglycoside producers for self-protection while functionally equivalent methyltransferases have been acquired by human and animal pathogenic bacteria. Here, we report structural and functional analyses of the Sorangium cellulosum So ce56 aminoglycoside resistance-conferring methyltransferase Kmr. Our results demonstrate that Kmr is a 16S rRNA methyltransferase acting at residue A1408 to confer a canonical aminoglycoside resistance spectrum in Escherichia coli. Kmr possesses a class I methyltransferase core fold but with dramatic differences in the regions which augment this structure to confer substrate specificity in functionally related enzymes. Most strikingly, the region linking core β-strands 6 and 7, which forms part of the S-adenosyl-l-methionine (SAM) binding pocket and contributes to base flipping by the m1A1408 methyltransferase NpmA, is disordered in Kmr, correlating with an exceptionally weak affinity for SAM. Kmr is unexpectedly insensitive to substitutions of residues critical for activity of other 16S rRNA (A1408) methyltransferases and also to the effects of by-product inhibition by S-adenosylhomocysteine (SAH). Collectively, our results indicate that adoption of a catalytically competent Kmr conformation and binding of the obligatory cosubstrate SAM must be induced by interaction with the 30S subunit substrate. PMID:25733511

  20. 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.

  1. Parametric model of the Mueller matrix of a Spectralon white reflectance standard deduced by polar decomposition techniques.

    PubMed

    Kildemo, Morten; Maria, Jérôme; Ellingsen, Pål G; Aas, Lars M S

    2013-07-29

    Decomposition methods have been applied to in-plane Mueller matrix ellipsometric scattering data of the Spectralon reflectance standard. Data were measured at the wavelengths 532 nm and 1500 nm, using an achromatic optimal Mueller matrix scatterometer applying a photomultiplier tube and a high gain InGaAs detector for the two wavelengths. A parametric model with physical significance was deduced through analysis of the product decomposed matrices. It is found that when the data are analyzed as a function of the scattering angle, similar to particle scattering, the matrix elements are largely independent of incidence angle. To the first order, we propose that a Guassian lineshape is appropriate to describe the polarization index, while the decomposed diagonal elements of the retardance matrix have a form resembling Rayleigh single scattering. New models are proposed for the off diagonal elements of the measured Mueller matrix. PMID:23938723

  2. Fracture-mechanics data deduced from thermal-shock and related experiments with LWR pressure-vessel material

    SciTech Connect

    Cheverton, R.D.; Canonico, D.A.; Iskander, S.K.; Bolt, S.E.; Holz, P.P.; Nanstad, R.K.; Stelzman, W.J.

    1982-01-01

    Pressurized water reactors (PWRs) are susceptible to certain types of hypothetical accidents that can subject the reactor pressure vessel to severe thermal shock, that is, a rapid cooling of the inner surface of the vessel wall. The thermal-shock loading, coupled with the radiation-induced reduction in the material fracture toughness, introduces the possibility of propagation of preexistent flaws and what at one time were regarded as somewhat unique fracture-oriented conditions. Several postulated reactor accidents have been analyzed to discover flaw behavior trends; seven intermediate-scale thermal-shock experiments with steel cylinders have been conducted; and corresponding materials characterization studies have been performed. Flaw behavior trends and related fracture-mechanics data deduced from these studies are discussed.

  3. 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.

  4. Estimate of carbonyl sulfide (OCS) volcanic source strength deduced from OCS/CO2 ratios in volcanic gases

    NASA Astrophysics Data System (ADS)

    Belviso, S.; Nguyen, B. C.; Allard, P.

    1986-02-01

    Measurements of the concentration ratio of OCS and CO2 were made in fumaroles of several volcanoes in Italy and Nicaragua. The values obtained, together with previous published data, demonstrate that the OCS/CO2 ratio is positively correlated with the emission temperature of the gases. It ranges from 10 to the -7.1 power to 10 to the -2.7 power at the Vulcano (90 C) and Erta'Ale (1130/C) volcanoes, respectively. The global OCS volcanic source strength, deduced from SO2 emission rates, CO2/SO2 and OCS/CO2 ratios in volcanic gases, is estimated to be in the range 6-90 x 10 to the 9th g OCS per year.

  5. 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.

  6. Structural and functional characterization of hBD-1(Ser35), a peptide deduced from a DEFB1 polymorphism.

    PubMed

    Circo, Raffaella; Skerlavaj, Barbara; Gennaro, Renato; Amoroso, Antonio; Zanetti, Margherita

    2002-04-26

    beta-Defensins are mammalian antimicrobial peptides that share a unique disulfide-bonding motif of six conserved cysteines. An intragenic polymorphism of the DEFB1 gene that changes a highly conserved Cys to Ser in the peptide coding region has recently been described. The deduced peptide cannot form three disulfide bonds, as one of the cysteines is unpaired. We have determined the cysteine connectivities of a corresponding synthetic hBD-1(Ser35) peptide, investigated the structure by circular dichroism spectroscopy, and assayed the in vitro antimicrobial activity. Despite a different arrangement of the disulfides, hBD-1(Ser35) proved as active as hBD-1 against the microorganisms tested. This activity likely depends on the ability of hBD-1(Ser35) to adopt an amphipathic conformation in hydrophobic environment, similar to the wild type peptide, as suggested by CD spectroscopy. PMID:12054642

  7. Phenotypic Switching in Candida glabrata Accompanied by Changes in Expression of Genes with Deduced Functions in Copper Detoxification and Stress

    PubMed Central

    Srikantha, Thyagarajan; Zhao, Rui; Daniels, Karla; Radke, Josh; Soll, David R.

    2005-01-01

    Most strains of Candida glabrata switch spontaneously between a number of phenotypes distinguishable by graded brown coloration on agar containing 1 mM CuSO4, a phenomenon referred to as “core switching.” C. glabrata also switches spontaneously and reversibly from core phenotypes to an irregular wrinkle (IWr) phenotype, a phenomenon referred to as “irregular wrinkle switching.” To identify genes differentially expressed in the core phenotypes white (Wh) and dark brown (DB), a cDNA subtraction strategy was employed. Twenty-three genes were identified as up-regulated in DB, four in Wh, and six in IWr. Up-regulation was verified in two unrelated strains, one a and one α strain. The functions of these genes were deduced from the functions of their Saccharomyces cerevisiae orthologs. The majority of genes up-regulated in DB (78%) played deduced roles in copper assimilation, sulfur assimilation, and stress responses. These genes were differentially up-regulated in DB even though the conditions of growth for Wh and DB, including CuSO4 concentration, were identical. Hence, the regulation of these genes, normally regulated by environmental cues, has been usurped by switching, presumably as an adaptation to the challenging host environment. These results are consistent with the suggestion that switching provides colonizing populations with a minority of cells expressing a phenotype that allows them to enrich in response to an environmental challenge, a form of rapid adaptation. However, DB is the most commonly expressed phenotype at sites of host colonization, in the apparent absence of elevated copper levels. Hence, up-regulation of these genes by switching suggests that in some cases they may play roles in colonization and virulence not immediately obvious from the roles played by their orthologs in S. cerevisiae. PMID:16087748

  8. The NMR solution structure of the 30S ribosomal protein S27e encoded in gene RS27_ARCFU of Archaeoglobus fulgidis reveals a novel protein fold

    PubMed Central

    Herve du Penhoat, Catherine; Atreya, Hanudatta S.; Shen, Yang; Liu, Gaohua; Acton, Thomas B.; Xiao, Rong; Li, Zhaohui; Murray, Diana; Montelione, Gaetano T.; Szyperski, Thomas

    2004-01-01

    The Archaeoglobus fulgidis gene RS27_ARCFU encodes the 30S ribosomal protein S27e. Here, we present the high-quality NMR solution structure of this archaeal protein, which comprises a C4 zinc finger motif of the CX2CX14-16CX2C class. S27e was selected as a target of the Northeast Structural Genomics Consortium (target ID: GR2), and its three-dimensional structure is the first representative of a family of more than 116 homologous proteins occurring in eukaryotic and archaeal cells. As a salient feature of its molecular architecture, S27e exhibits a β-sandwich consisting of two three-stranded sheets with topology B(↓), A(↑), F(↓), and C(↑), D(↓), E(↑). Due to the uniqueness of the arrangement of the strands, the resulting fold was found to be novel. Residues that are highly conserved among the S27 proteins allowed identification of a structural motif of putative functional importance; a conserved hydrophobic patch may well play a pivotal role for functioning of S27 proteins, be it in archaeal or eukaryotic cells. The structure of human S27, which possesses a 26-residue amino-terminal extension when compared with the archaeal S27e, was modeled on the basis of two structural templates, S27e for the carboxy-terminal core and the amino-terminal segment of the archaeal ribosomal protein L37Ae for the extension. Remarkably, the electrostatic surface properties of archaeal and human proteins are predicted to be entirely different, pointing at either functional variations among archaeal and eukaryotic S27 proteins, or, assuming that the function remained invariant, to a concerted evolutionary change of the surface potential of proteins interacting with S27. PMID:15096641

  9. Geometrical analysis of the structure in the western flank of the Chilean Andes at 34°15'S-34°30'S

    NASA Astrophysics Data System (ADS)

    Jara, P. P.; Charrier, R.; Arriagada, C.; Farias, M.

    2007-12-01

    We present a structural analysis of strongly deformed Cenozoic volcanic rocks of the western Principal Cordillera between 34°15'S and 34°30'S. Deformation has been related to the inversion of the Abanico Basin occurred between 22 and 16 Ma. The structural array is characterized by a syncline with a very steep western limb and a rather flat slightly folded axial zone. On both sides of this structure, layers dip in directions opposite to the syncline flanks, suggesting disruption of anticlines by faulting. The reconstructed geometry performed on 6 cross- sections indicates that: 1. Deformation occurred by "fault-propagation folding" with considerable fault displacement, and 2. The anticlines were transported by the faults cutting their crests along the axial plane, similar to the anticlinal breakthrough deformation modes. Based on this mechanism and the relations between the axial and cut off angles, we developed a kinematic model using geometric methods and the Trishear program. Results suggests that folding was controlled by two E-vergent faults (western, WF, and eastern, EF). The most important (WF) would have a cutoff angle 40°-60°, which is compatible with inverted normal faults. Indeed, the regional nature of shortening in this region has been interpreted as the result of basin inversion. The EF has a cutoff angle of about 20 degrees, which is compatible with a neoformed thrust and allowing its interpretation as a short cut. These structures have accommodated ca. 30% (2 to 3 km) of shortening in this region. Although our proposition at depth for the main fault geometry is based on the surface analysis, it is quite consistent with the structural array interpreted by seismicity and MT images. Moreover, this structure seems to be the upward prolongation of a W-dipping ramp structure, connecting the subduction zone with the tectonic front of the mountain belt, in a zone where the ramp flattens and forms a detachment at 15-20 km depth beneath the western edge of

  10. 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).

  11. 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

  12. Deducing receptor signaling parameters from in vivo analysis: LuxN/AI-1 quorum sensing in Vibrio harveyi

    PubMed Central

    Swem, Lee R.; Swem, Danielle L.; Wingreen, Ned S.; Bassler, Bonnie L.

    2008-01-01

    Summary Quorum sensing, a process of bacterial cell-cell communication, relies on production, detection, and response to autoinducer signaling molecules. Here we focus on LuxN, a nine transmembrane domain protein from Vibrio harveyi, and the founding example of membrane-bound receptors for acyl-homoserine lactone (AHL) autoinducers. Previously, nothing was known about signal recognition by membrane-bound AHL receptors. We used mutagenesis and suppressor analyses to identify the AHL-binding domain of LuxN, and discovered LuxN mutants that confer decreased and increased AHL sensitivity. Our analysis of dose-response curves of multiple LuxN mutants pins these inverse phenotypes on quantifiable opposing shifts in the free-energy bias of LuxN for its kinase and phosphatase states. To extract signaling parameters, we exploited a strong LuxN antagonist, one of fifteen small-molecule antagonists we identified. We find that quorum-sensing-mediated communication can be manipulated positively and negatively to control bacterial behavior, and that signaling parameters can be deduced from in vivo data. PMID:18692469

  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. 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.

  15. Interseismic strain accumulation across the North Tabriz Fault (NW Iran) deduced from InSAR time series

    NASA Astrophysics Data System (ADS)

    Karimzadeh, Sadra; Cakir, Ziyadin; Osmanoğlu, Batuhan; Schmalzle, Gina; Miyajima, Masakatsu; Amiraslanzadeh, Reza; Djamour, Yahya

    2013-05-01

    We present the surface deformation along the North Tabriz Fault (NTF) deduced from Synthetic Aperture Radar Interferometry (InSAR) technique. The NTF, a major right-lateral strike-slip fault within the active Arabia-Eurasia collision zone, is located 40-45 km southwest of the Mw 6.5 and Mw 6.3, August 11, 2012 earthquake sequence that caused heavy damage and more than 300 deaths in Ahar, NW Iran. InSAR time series analysis of 17 ENVISAT radar images acquired between 2004 and 2010 using combination of the permanent scatterers InSAR (PSI) and the small baseline InSAR (SBAS) approach reveals sub-centimeter interseismic strain accumulation across the NTF and rapid subsidence in the Tabriz basin. Elastic dislocation modeling of the mean line-of-sight velocity field estimated from SBAS time series yields an average slip rate of 8.7 ± 2.5 mm/year with a locking depth of 15.8 ± 10.8 km. This rate is consistent with previous geodetic estimates based on recent Global Positioning System measurements, and suggests a recurrence interval of 250-300 years for major earthquakes of Mw 7.0-7.3 on the NTF, much shorter than those estimated from paleoseismic investigations (821 ± 176 years). This in turn implies a high seismic potential on the NTF taking into account the occurrence of the two last earthquakes on the NTF in 1721 and 1780. SAR time series analysis also reveals three regions of rapid subsidence with a maximum rate of 20 mm/year near the Tabriz thermal power plant in the Tabriz basin. Piezometric data from groundwater wells suggest that accelerated subsidence over the last several years may result from fluctuations in the ground water table.

  16. 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

  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. Tables of Neutron-Induced Fission Cross Section for Various Pu, U, and Th Isotopes, Deduced from Measured Fission Probabilites

    SciTech Connect

    Younes, W; Britt, H C

    2003-03-31

    Cross sections for neutron-induced fission of {sup 231,233}Th, {sup 234,235,236,237,239}U, and {sup 240,241,243}Pu are presented in tabular form for incident neutron energies of 0.1 {le} E{sub n}(MeV) {le} 2.5. The cross sections were obtained by converting measured fission probabilities from (t,pf) reactions on mass-A targets to (n,f) cross sections on mass-A + 1 neutron targets, by using modeling to compensate for the differences in the reaction mechanisms. Data from Britt et al. were used for the {sup 234}U(t,pf) reaction, from Cramer et al. for the {sup 230,232}Th(t,pf), {sup 236,238}U(t,pf), and {sup 240,242}Pu(t,pf) reactions, and from Britt et al. for the {sup 233,235}U(t,pf) and {sup 239}Pu(t,pf) reactions. The fission probabilities P{sub (t,pf)}(E{sub x}), measured as a function of excitation energy E{sub x} of the compound system formed by the (t,p) reaction, are listed in the tables with the corresponding deduced cross sections as a function of incident neutron energy E{sub n}, {sigma}{sub (n,f)}(E{sub n}). The excitation energy and incident neutron energy are related by E{sub x} = E{sub n} + B{sub n}, where B{sub n}, where B{sub n} is the neutron binding energy. Comparison with ENDF/B-VI evaluations of the well-measured {sup 234,235,236}U(n,f) and {sup 240,241}Pu(n,f) cross sections confirms the accuracy of the present results within a 10% standard deviation above E{sub n} = 1 MeV. Below E{sub n} = 1 MeV, localized deviations of at most {+-} 20% are observed.

  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. 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

  1. 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

  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. 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

  4. Vertical ozone distribution characteristics deduced from 44,000 re-evaluated Umkehr profiles (1957-2000)

    NASA Astrophysics Data System (ADS)

    Bojkov, R. D.; Kosmidis, E.; DeLuisi, J. J.; Petropavlovskikh, I.; Fioletov, V. E.; Godin, S.; Zerefos, C.

    maximum. The deduced trends above 33km confirm a strong ozone decline since the mid-1970s of over 5% per decade without significant seasonal differences. In the mid-latitude stations, the decline in the 15-24km layer is nearly twice as strong in the winter-spring season but much smaller in the summer and fall. The effect of including 1998 and 1999 years with relatively high total ozone data reduces the overall-declining trend. The trends estimated from alg-99 retrievals are statistically not significantly different from those in WMO 1998a; however, they are stronger by about 1% per decade in the lower stratosphere and thus closer to the estimates by sondes. Comparisons of the integrated ozone loss from the Umkehr measurements with the total ozone changes for the same periods at stations with good records show complete concurrence. The altitude and latitude appearances of the long-term geophysical signals like solar (1-2%) and QBO (2-7%) are investigated.

  5. Modelling Al-4wt.%Cu as-cast structure using equiaxed morphological parameters deduced from in-situ synchrotron X-ray radiography

    NASA Astrophysics Data System (ADS)

    Ahmadein, M.; Wu, M.; Reinhart, G.; Nguyen-Thi, H.; Ludwig, A.

    2016-03-01

    The as-cast structure of laboratory scale Al-4wt.%Cu was numerically calculated using assumed morphological parameters. Two parameters are identified: The shape factor which correlates the growth velocity of dendrite envelope to that of the tip; and the sphericity of the equiaxed envelope or the circularity of the columnar trunk envelope which is required to calculate the averaged species diffusion flux across the envelope. In the present work, the real-time radiographs of equiaxed solidification experiment carried out on Al-4wt.%Cu at the European Synchrotron Radiation Facility are used to track the development of crystal envelope with time. The growth rate of the equivalent circular envelope was correlated to dendrite tip growth velocity to deduce the shape factor. The sphericity of dendrite envelope is estimated over the time. The average of the deduced morphological parameters is applied to the model to predict the as-cast structure. The results were compared to those obtained by using morphological parameters from literature. The predicted phase quantities, columnar-to- equiaxed transition, and macrosegregation exhibited significant dependence on those parameters. The predicted macrosegregation using the experimentally deduced parameters fits better to the measurements.

  6. Banned on Broadway but coming to a theater near you: the captive and rethinking the breadth of American anti-lesbian hostility in the 1920s and '30s.

    PubMed

    Hurewitz, Daniel

    2013-01-01

    While the 1927 Broadway closing of the lesbian-themed play The Captive has been treated as launching the homophobic culture that dominated mid-twentieth-century America, the show actually continued to play in cities around the country. It was regularly greeted by packed houses and critics who scoffed at the reaction in New York. The opposition that did emerge was often generated by publisher William Randolph Hearst, while leading civil libertarians fought against him. This demonstrates that the homophobic policies of the 1920s and '30s were not the product of a deeply homophobic society, but generated by smaller numbers of moralizing entreprenuers. PMID:23316840

  7. 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.

  8. 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

  9. The NADH-binding subunit of the energy-transducing NADH-ubiquinone oxidoreductase of Paracoccus denitrificans: Gene cloning and deduced primary structure

    SciTech Connect

    Xu, Xuemin; Matsuno-Yagi, Akemi; Yagi, Takao )

    1991-07-02

    The NADH dehydrogenase complex isolated from Paracoccus denitrificans is composed of approximately 10 unlike polypeptides and contains noncovalently bound FMN, non-heme iron, and acid-labile sulfide. The NADH-binding subunit of this enzyme complex was identified by direct photoaffinity labeling with ({sup 32}P)NADH. primers were synthesized on the basis of the N-terminal amino acid sequency of this polypeptide, and these primers were used to synthesize an oligonucleotide probe by the polymerase chain reaction. This probe was utilized to isolate the gene encoding the NADH-binding subunit from a genomic library of P. denitrificans. The nucleotide sequence of the gene and the deduced amino acid sequence of the entire NADH-binding subunit were determined. The NADH-binding subunit has 431 amino acid residues and a calculated molecular weight of 47 191. The encoded protein contains a putative NAD(H)-binding and an iron-sulfur cluster-binding consensus sequence. The deduced amino acid sequence of the Paracoccus NADH-binding subunit shows remarkable similarity to the {alpha} subunit of the NAD-linked hydrogenase of Alcaligenes eutrophus H16. When partial DNA sequencing of the regions surrounding the gene encoding the NADH-binding subunit was carried out, sequences homologous to the 24-, 49-, and 75-kDa polypeptides of bovine complex 1 were detected, suggesting that the structural genes of the Paracoccus NADH dehydrogenase complex constitute a gene cluster.

  10. 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

  11. Nuclear Fluxes in Diatomic Molecules Deduced from Pump-Probe Spectra with Spatiotemporal Resolutions down to 5 pm and 200 asec

    NASA Astrophysics Data System (ADS)

    Manz, Jörn; Pérez-Torres, Jhon Fredy; Yang, Yonggang

    2013-10-01

    When molecules move, their nuclei flow. The corresponding quantum observable, i.e., the nuclear flux density, was introduced by Schrödinger in 1926, but until now, it has not been measured. Here the first experimental results are deduced from high-resolution pump-probe measurements of the time-dependent nuclear densities in a vibrating diatomic molecule or molecular ion. The nuclear densities are converted to flux densities by means of the continuity equation. The flux densities are much more sensitive to time-dependent quantum effects than the densities. Applications to the sodium molecule and the deuterium molecular ion unravel four new effects; e.g., at the turns from bond stretch to compression, the flux of the nuclei exhibits multiple changes of directions, from small to large bond lengths, a phenomenon that we call the “quantum accordion.”

  12. Nucleotide sequence of the phosphoglycerate kinase gene from the extreme thermophile Thermus thermophilus. Comparison of the deduced amino acid sequence with that of the mesophilic yeast phosphoglycerate kinase.

    PubMed Central

    Bowen, D; Littlechild, J A; Fothergill, J E; Watson, H C; Hall, L

    1988-01-01

    Using oligonucleotide probes derived from amino acid sequencing information, the structural gene for phosphoglycerate kinase from the extreme thermophile, Thermus thermophilus, was cloned in Escherichia coli and its complete nucleotide sequence determined. The gene consists of an open reading frame corresponding to a protein of 390 amino acid residues (calculated Mr 41,791) with an extreme bias for G or C (93.1%) in the codon third base position. Comparison of the deduced amino acid sequence with that of the corresponding mesophilic yeast enzyme indicated a number of significant differences. These are discussed in terms of the unusual codon bias and their possible role in enhanced protein thermal stability. Images Fig. 1. PMID:3052437

  13. 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.

  14. 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

  15. 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

  16. Hemispheric asymmetry in transition from equatorial plasma bubble to blob as deduced from 630.0 nm airglow observations at low latitudes

    NASA Astrophysics Data System (ADS)

    Park, Jaeheung; Martinis, Carlos R.; Lühr, Hermann; Pfaff, Robert F.; Kwak, Young-Sil

    2016-01-01

    Transitions from depletions to enhancements of 630.0 nm nighttime airglow have been observed at Arecibo. Numerical simulations by Krall et al. (2009) predicted that they should occur only in one hemisphere, which has not yet been confirmed observationally. In this study we investigate the hemispheric conjugacy of the depletion-to-enhancement transition using multiple instruments. We focus on one event observed in the American longitude sector on 22 December 2014: 630.0 nm airglow depletions evolved into enhancements in the Northern Hemisphere while the evolution did not occur in the conjugate location in the Southern Hemisphere. Concurrent plasma density measured by low Earth orbit (LEO) satellites and 777.4 nm airglow images support that the depletions and enhancements of 630.0 nm nighttime airglow reflect plasma density decreases and increases (blobs), respectively. Characteristics of the airglow depletions, in the context of the LEO satellite data, further suggest that the plasma density depletion deduced from the airglow data represents equatorial plasma bubbles (EPBs) rather than medium-scale traveling ionospheric disturbances from midlatitudes. Hence, the event in this study can be interpreted as EPB-to-blob transition.

  17. Lateral inhomogeneity deduced from 3-D magnetotelluric modeling around the hypocentral area of the 1984 Western Nagano Prefecture earthquake, central Japan

    NASA Astrophysics Data System (ADS)

    Kasaya, T.; Oshiman, N.

    2004-05-01

    Earthquake swarms have been observed since 1976 in the southeastern region of Mt. Ontake, where the 1984 Western Nagano Prefecture earthquake (M6.8) occurred. Most earthquake swarm activities show a dense distribu-tion in a narrow area and at shallow depths. We have carried out forward 3-D magnetotelluric modeling for the data set observed around the focal region of the earthquake swarms. An initial 3-D image was constructed based on previous 2-D magnetotelluric analysis results. The resistivity structure shows remarkable lateral inhomogeneity: a low resistivity zone is located at shallow depth around the center of the study area and the low resistivity zone is surrounded by a high resistive structure and its shape is about a 4-km cube. This feature agrees well with the distribution of the degree of water saturation deduced from seismic information. Hypocenters of recent seismicity are distributed around an area between the resistivity boundary and the relatively high-resistance region. This fact strongly suggests that earthquakes in the study area are triggered by fluid (water) in the crust.

  18. Low-energy tail of the giant dipole resonance in Mo98 and Mo100 deduced from photon-scattering experiments

    NASA Astrophysics Data System (ADS)

    Rusev, G.; Schwengner, R.; Dönau, F.; Erhard, M.; Grosse, E.; Junghans, A. R.; Kosev, K.; Schilling, K. D.; Wagner, A.; Bečvář, F.; Krtička, M.

    2008-06-01

    Dipole-strength distributions in the nuclides Mo98 and Mo100 up to the neutron-separation energies have been studied in photon-scattering experiments at the bremsstrahlung facility of the Forschungszentrum Dresden-Rossendorf. To determine the dipole-strength distributions up to the neutron-emission thresholds, statistical methods were developed for the analysis of the measured spectra. The measured spectra of scattered photons were corrected for detector response and atomic background by simulations using the code GEANT3. Simulations of γ-ray cascades were performed to correct the intensities of the transitions to the ground state for feeding from higher-lying levels and to determine their branching ratios. The photoabsorption cross sections obtained for Mo98 and Mo100 from the present (γ,γ') experiments are combined with (γ,n) data from literature, resulting in a photoabsorption cross section covering the range from 4 to about 15 MeV of interest for network calculations in nuclear astrophysics. Novel information about the low-energy tail of the giant dipole resonance and its energy dependence is derived. The photoabsorption cross sections deduced from the present photon-scattering experiments are compared with existing data from neutron capture and He3-induced reactions.

  19. 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

  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. PMID:26199104

  1. 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.

  2. 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

  3. Excitation of the E2 and W1 "Arched" Filaments Near the Galactic Center as Deduced from Far-Infrared Spectroscopy

    NASA Technical Reports Server (NTRS)

    Colgan, Sean W.J.; Erickson, Edwin F.; Simpson, Janet P.; Haas, Michael R.; Morris, Mark

    1994-01-01

    We present measurements of the far-infrared (FIR) fine structure lines [S III] (33 microns), [Si II] (35 microns), [O III] (51, 88 microns), [O I] (63 microns) and [C II] (158 microns) and the adjacent continua along a scan crossing the E2 and W1 thermal radio filaments in the Galactic center 'Arc'. The deduced electron density and excitation vary along the scan by less than factors of two and three, respectively. The properties of the two filaments are similar: the line and continuum fluxes peak at the radio ridge, and the ridge/off-ridge contrast is greatest for the FIR continuum and ionized lines, lower for the single dish radio measurements (Sofue et al. 1986), and smallest for the low excitation lines. The spatial coincidence of the FIR and radio peaks demonstrates that any excitation mechanism for the radio continuum filaments must also account for the FIR line and continuum emission. The FIR luminosity of approx. 3 x 10(exp 5) Solar Luminosity per beam, and the association of [O III] emission with the filaments poses difficulties for shock and MHD models. Photoionization of molecular cloud edges by a random distribution of stars is the most likely excitation mechanism among those proposed. The continuum and the low excitation line fluxes are consistent with an origin in photodissociated molecular material adjacent to the photoionized gas.

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

    PubMed Central

    Hammond, G L; Smith, C L; Goping, I S; Underhill, D A; Harley, M J; Reventos, J; Musto, N A; Gunsalus, G L; Bardin, C W

    1987-01-01

    We have isolated and sequenced cDNAs for corticosteroid binding globulin (CBG) prepared from human liver and lung mRNAs. Our 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 (Mr 45,149) polypeptide. This includes a predominantly hydrophobic, leader sequence of 22 residues that precedes the known NH2-terminal sequence of human CBG. We, therefore, predict that the mature protein is composed of 383 amino acids and is a polypeptide of Mr 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 we 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 alpha 1-antitrypsin, and this extends to other members of the serpin (serine protease inhibitor) superfamily. Images PMID:3299377

  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. Variation in aspects of cysteine proteinase catalytic mechanism deduced by spectroscopic observation of dithioester intermediates, kinetic analysis and molecular dynamics simulations.

    PubMed

    Reid, J D; Hussain, S; Sreedharan, S K; Bailey, T S; Pinitglang, S; Thomas, E W; Verma, C S; Brocklehurst, K

    2001-07-15

    The possibility of a slow post-acylation conformational change during catalysis by cysteine proteinases was investigated by using a new chromogenic substrate, N-acetyl-Phe-Gly methyl thionoester, four natural variants (papain, caricain, actinidin and ficin), and stopped-flow spectral analysis to monitor the pre-steady state formation of the dithioacylenzyme intermediates and their steady state hydrolysis. The predicted reversibility of acylation was demonstrated kinetically for actinidin and ficin, but not for papain or caricain. This difference between actinidin and papain was investigated by modelling using QUANTA and CHARMM. The weaker binding of hydrophobic substrates, including the new thionoester, by actinidin than by papain may not be due to the well-known difference in their S2-subsites, whereby that of actinidin in the free enzyme is shorter due to the presence of Met211. Molecular dynamics simulation suggests that during substrate binding the sidechain of Met211 moves to allow full access of a Phe sidechain to the S2-subsite. The highly anionic surface of actinidin may contribute to the specificity difference between papain and actinidin. During subsequent molecular dynamics simulations the P1 product, methanol, diffuses rapidly (over<8 ps) out of papain and caricain but 'lingers' around the active centre of actinidin. Uniquely in actinidin, an Asp142-Lys145 salt bridge allows formation of a cavity which appears to constrain diffusion of the methanol away from the catalytic site. The cavity then undergoes large scale movements (over 4.8 A) in a highly correlated manner, thus controlling the motions of the methanol molecule. The changes in this cavity that release the methanol might be those deduced kinetically. PMID:11439083

  10. Variation in aspects of cysteine proteinase catalytic mechanism deduced by spectroscopic observation of dithioester intermediates, kinetic analysis and molecular dynamics simulations.

    PubMed Central

    Reid, J D; Hussain, S; Sreedharan, S K; Bailey, T S; Pinitglang, S; Thomas, E W; Verma, C S; Brocklehurst, K

    2001-01-01

    The possibility of a slow post-acylation conformational change during catalysis by cysteine proteinases was investigated by using a new chromogenic substrate, N-acetyl-Phe-Gly methyl thionoester, four natural variants (papain, caricain, actinidin and ficin), and stopped-flow spectral analysis to monitor the pre-steady state formation of the dithioacylenzyme intermediates and their steady state hydrolysis. The predicted reversibility of acylation was demonstrated kinetically for actinidin and ficin, but not for papain or caricain. This difference between actinidin and papain was investigated by modelling using QUANTA and CHARMM. The weaker binding of hydrophobic substrates, including the new thionoester, by actinidin than by papain may not be due to the well-known difference in their S2-subsites, whereby that of actinidin in the free enzyme is shorter due to the presence of Met211. Molecular dynamics simulation suggests that during substrate binding the sidechain of Met211 moves to allow full access of a Phe sidechain to the S2-subsite. The highly anionic surface of actinidin may contribute to the specificity difference between papain and actinidin. During subsequent molecular dynamics simulations the P1 product, methanol, diffuses rapidly (over<8 ps) out of papain and caricain but 'lingers' around the active centre of actinidin. Uniquely in actinidin, an Asp142-Lys145 salt bridge allows formation of a cavity which appears to constrain diffusion of the methanol away from the catalytic site. The cavity then undergoes large scale movements (over 4.8 A) in a highly correlated manner, thus controlling the motions of the methanol molecule. The changes in this cavity that release the methanol might be those deduced kinetically. PMID:11439083

  11. Molecular cloning and expression of partial cDNAs and deduced amino acid sequence of a carboxyl-terminal fragment of human apolipoprotein B-100.

    PubMed Central

    Wei, C F; Chen, S H; Yang, C Y; Marcel, Y L; Milne, R W; Li, W H; Sparrow, J T; Gotto, A M; Chan, L

    1985-01-01

    Apolipoprotein (apo) B-100 cDNAs were identified in a human liver cDNA library cloned in the expression vector lambda gt11. The beta-galactosidase-apoB-100 fusion protein was detected by two independently produced low density lipoprotein polyclonal antisera and by three apoB-100 monoclonal antibodies that crossreact with apoB-74. It was not recognized by two apoB-100 monoclonal antibodies that crossreact with apoB-26. The longest clone, lambda B8, was completely sequenced. It contains a 2.8-kilobase DNA fragment containing the codons for the carboxyl-terminal 836 amino acid residues of apo-B-100, as well as the 3' untranslated region of apoB-100 mRNA. We have thus mapped apoB-74 to the carboxyl-terminal portion of apoB-100. The deduced amino acid sequence of the cloned DNA matches the sequences of 14 apoB-100 peptides determined in our laboratory. Minor differences in amino acid sequence were noted in three of the peptides, suggesting polymorphism of apoB-100 at the protein and DNA levels. Secondary structure predictions reveal an unusual pattern for apolipoproteins, consisting of beta-structure (24%), alpha-helical content (33%), and random structure (30%). Ten amphipathic helical regions of 10-24 residues were identified. This carboxyl-terminal fragment of apoB-100 is considerably more hydrophobic than other apolipoproteins with known structure. Its lipid binding regions might include stretches of highly hydrophobic beta-sheets as well as amphipathic helices. Our findings on apoB structure might be important for understanding the role of apoB-100-containing lipoproteins in atherosclerosis. PMID:2932736

  12. The integration of gravity, magnetic and seismic data in delineating the sedimentary basins of northern Sinai and deducing their structural controls

    NASA Astrophysics Data System (ADS)

    Selim, El Sayed Ibrahim

    2016-01-01

    The Sinai Peninsula is a part of the Sinai sub-plate that located between the southeast Nubian-Arabian shield and the southeastern Mediterranean northward. The main objectives of this investigation are to deduce the main sedimentary basin and its subdivisions, identify the subsurface structural framework that affects the study area and determine the thickness of sedimentary cover of the basement surface. The total intensity magnetic map, Bouguer gravity map and seismic data were used to achieve the study aims. Structural interpretation of the gravity and magnetic data were done by applying advanced processing techniques. These techniques include; Reduce to the pole (RTP), Power spectrum, Tile derivative and Analytical Signal techniques were applied on gravity and magnetic data. Two dimensional gravity and magnetic modeling and interpretation of seismic sections were done to determine the thickness of sedimentary cover of the study area. The integration of our interpretation suggests that, the northern Sinai area consists of elongated troughs that contain many high structural trends. Four major structural trends have been identified, that, reflecting the influence of district regional tectonic movements. These trends are: (1) NE-SW trend; (2) NNW-SSE trend; (3) ENE-WSW trend and (4) WNW-ESE trend. There are also many minor trends, E-W, NW-SE and N-S structural trends. The main sedimentary basin of North Sinai is divided into four sub-basins; (1) Northern Maghara; (2) Northeastern Sinai; (3) Northwestern Sinai and (4) Central Sinai basin. The sedimentary cover ranges between 2 km and 7 km in the northern part of the study area.

  13. 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

  14. 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

  15. Nucleotide and deduced amino acid sequences of the nucleocapsid protein of the virulent A75/17-CDV strain of canine distemper virus.

    PubMed

    Stettler, M; Zurbriggen, A

    1995-05-01

    Virus persistence is essential in the chronic inflammatory canine distemper virus (CDV)-induced demyelinating disease. In the case of CDV there is a close association between persistence and virulence. Virulent CDV isolated from dogs with distemper shows immediate persistence in primary dog brain cell cultures (DBCC) and in different cell lines. We have evidence that the nucleocapsid (NP) protein plays an important role in the development of persistence. The NP-protein, the most abundant structural virus protein, also influences virus assembly and has some regulatory functions in virus transcription and replication. In this study we compared the nucleotide and deduced amino acid sequence of a virulent CDV strain (A75/17-CDV) to a culture-attenuated non-virulent strain (OP-CDV). Viral RNA was extracted from DBCC infected with virulent CDV. Virulent CDV retains its in vivo properties, such as virulence and ability to cause demyelination, when propagated in these DBCC. The viral RNA was reverse transcribed and the resulting cDNA amplified by polymerase chain reaction for subsequent cloning. The nucleotide sequences of these clones were determined by the dideoxy chain termination method. The number of nucleotides and the putative NP-protein of the virulent strain matched the attenuated CDV strain. We observed a total of 105 nucleotide differences. Three were localised within the 3' and five within the 5' non-coding region of the NP-gene. The 97 nucleotide changes within the coding region resulted in 22 amino acid differences. 10 of these amino acid (AA) modifications were within the N-terminal region (AA 1 to 159) and 12 within the C-terminal area (AA 351 to 523).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8588315

  16. Cross-linking of initiation factor IF3 to Escherichia coli 30S ribosomal subunit by trans-diamminedichloroplatinum(II): characterization of two cross-linking sites in 16S rRNA; a possible way of functioning for IF3.

    PubMed Central

    Ehresmann, C; Moine, H; Mougel, M; Dondon, J; Grunberg-Manago, M; Ebel, J P; Ehresmann, B

    1986-01-01

    The initiation factor IF3 is platinated with trans-diamminedichloroplatinum(II) and cross-linked to Escherichia coli 30S ribosomal subunit. Two cross-linking sites are unambiguously identified on the 16S rRNA: a major one, in the region 819-859 in the central domain, and a minor one, in the region 1506-1529 in the 3'-terminal domain. Specific features of these sequences together with their particular location within the 30S subunit lead us to postulate a role for IF3, that conciliates topographical and functional observations made so far. Images PMID:2425339

  17. Evidence of different ocean responses to atmospheric pressurevariations in the Atlantic, Indian and Pacific Basins as deduced fromERS-2 altimetric data

    NASA Astrophysics Data System (ADS)

    Gómez-Enri, J.; Villares, P.; Bruno, M.; Catalán, M.

    2004-02-01

    . The exponential increase in the use of altimeter data in oceanographic studies in the past two decades has improved the knowledge of the processes that govern the interaction between the ocean and the atmosphere. One of these processes is the response of the ocean to atmospheric pressure variations, which has been deeply analysed in the past. That response is based on the isostatic assumption used to establish a standard correction for altimetric purposes, the Inverse Barometer Correction (IBC). As a general rule, the ocean goes up/down 1cm when the atmospheric pressure goes down/up 1mbar. However, in light of recent works in some oceanic regions, discrepancies arise when the real response is compared to the hypothetical one. It is important to quantify this discrepancy, in order to improve the accuracy of the correction, which is one of the most significant geophysical corrections applied to altimeter records. Some aspects of this response remain unclear, such as the real space-temporal scales where IBC can be applied, the influence of wind, non-isostatic atmospheric pressure-driven signals, and the effect of aliasing from high frequency signals. This paper is an attempt to gain insight into this phenomenon. The data used are the residuals obtained between sea surface heights from the ERS-2 altimeter and the outputs of a global barotropic ocean model. Significant departures from the hypothetical isostatic response in all data series (spatial and temporal domain) have been found, especially in the case of altimeter records. By applying the collinear track method, we observe that the estimated Atlantic Ocean response is quite similar to the one deduced from the isostatic assumption at all latitudinal bands. Nonetheless, the Indian and Pacific Oceans show important departures from the hypothetical value at low latitudes. Results obtained with the crossover track method show important deviations at low latitudes in the three basins. In order to understand why the

  18. H2rs: Deducing evolutionary and functionally important residue positions by means of an entropy and similarity based analysis of multiple sequence alignments

    PubMed Central

    2014-01-01

    Background The identification of functionally important residue positions is an important task of computational biology. Methods of correlation analysis allow for the identification of pairs of residue positions, whose occupancy is mutually dependent due to constraints imposed by protein structure or function. A common measure assessing these dependencies is the mutual information, which is based on Shannon’s information theory that utilizes probabilities only. Consequently, such approaches do not consider the similarity of residue pairs, which may degrade the algorithm’s performance. One typical algorithm is H2r, which characterizes each individual residue position k by the conn(k)-value, which is the number of significantly correlated pairs it belongs to. Results To improve specificity of H2r, we developed a revised algorithm, named H2rs, which is based on the von Neumann entropy (vNE). To compute the corresponding mutual information, a matrix A is required, which assesses the similarity of residue pairs. We determined A by deducing substitution frequencies from contacting residue pairs observed in the homologs of 35 809 proteins, whose structure is known. In analogy to H2r, the enhanced algorithm computes a normalized conn(k)-value. Within the framework of H2rs, only statistically significant vNE values were considered. To decide on significance, the algorithm calculates a p-value by performing a randomization test for each individual pair of residue positions. The analysis of a large in silico testbed demonstrated that specificity and precision were higher for H2rs than for H2r and two other methods of correlation analysis. The gain in prediction quality is further confirmed by a detailed assessment of five well-studied enzymes. The outcome of H2rs and of a method that predicts contacting residue positions (PSICOV) overlapped only marginally. H2rs can be downloaded from http://www-bioinf.uni-regensburg.de. Conclusions Considering substitution frequencies

  19. 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.

  20. The Na(+)-translocating ATPase of Acetobacterium woodii is a F1F0-type enzyme as deduced from the primary structure of its beta, gamma and epsilon subunits.

    PubMed

    Forster, A; Daniel, R; Müller, V

    1995-05-10

    A 4.5 kbp EcoRI fragment hybridizing to a fragment of uncD (coding for subunit beta of F1F0-ATPases) was cloned from chromosomal DNA of Acetobacterium woodii. The nucleotide sequence was determined and revealed five open reading frames (ORF), four of which were identified to code for subunits of the Na(+)-ATPase. The deduced amino acid sequences of these ORF's are homologous to subunit alpha (partial coding sequence, C-terminal end), gamma, beta and epsilon of F1F0-ATPases from various organisms; furthermore, the organization of the genes in the order uncA (alpha), uncG (gamma), uncD (beta), uncC (epsilon) is identical to the structure of unc operon as present in most bacteria. Downstream of uncC is an ORF whose deduced amino acid sequence has 53% sequence homology to AlgD from Pseudomonas aeruginosa. The structure and organization of the unc genes are the final proof that the Na(+)-ATPase from A. woodii is a member of the family of F1F0-ATPases. PMID:7748890

  1. 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.

  2. 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 ...

  3. Long-term changes in UT/LS ozone between the late 1970s and the 1990s deduced from the GASP and MOZAIC aircraft programs and from ozonesondes

    NASA Astrophysics Data System (ADS)

    Schnadt Poberaj, C.; Staehelin, J.; Brunner, D.; Thouret, V.; de Backer, H.; Stübi, R.

    2009-01-01

    We present ozone measurements of the Global Atmospheric Sampling Program (GASP) performed from four commercial and one research aircraft in the late 1970s to compare them with respective measurements of the ongoing MOZAIC project. Climatologies of UT/LS ozone were built using the aircraft data sets (1975-1979 and 1994-2001), and long-term changes between the 1970s and 1990s were derived by comparison. The data were binned relative to the dynamical tropopause to separate between UT and LS air masses. LS data were analysed using equivalent latitudes. In the UT, pronounced increases are found over the Middle East and South Asia in the spring and summer seasons. Increases are also found over Japan, Europe, and the eastern parts of the Unites States depending on season. LS ozone over northern mid- and high latitudes was found to be lower in the 1990s compared to the 1970s in all seasons of the year. In addition, a comparison with long-term changes deduced from ozonesondes is presented. An altitude offset was applied to the sonde data to account for the slow response time of the ozone sensors. The early 1970s European Brewer-Mast (BM) sonde data agree with GASP within the range of uncertainty (UT) or measured slightly less ozone (LS). In contrast, the 1990s BM sensors show consistently and significantly higher UT/LS ozone values than MOZAIC. This unequal behaviour of aircraft/sonde comparisons in the 1970s and 1990s leads to differences in the estimated long-term changes over Europe: while the comparison between GASP and MOZAIC indicates ozone changes of -5% to 10% over Europe, the sondes suggest a much larger increase of 10%-35% depending on station and season, although statistical significance is not conclusive due to data sample limitations. In contrast to the BM sondes, the Electrochemical Cell (ECC) sonde at Wallops Island, USA, measured higher UT ozone than both GASP and MOZAIC. Hence, long-term changes from GASP/MOZAIC agree within the range of uncertainty with

  4. Long-term changes in UT/LS ozone between the late 1970s and the 1990s deduced from the GASP and MOZAIC aircraft programs and from ozonesondes

    NASA Astrophysics Data System (ADS)

    Schnadt Poberaj, C.; Staehelin, J.; Brunner, D.; Thouret, V.; de Backer, H.; Stübi, R.

    2009-07-01

    We present ozone measurements of the Global Atmospheric Sampling Program (GASP) performed from four commercial and one research aircraft in the late 1970s to compare them with respective measurements of the ongoing MOZAIC project. Multi-annual averages of UT/LS ozone were built using the aircraft data sets (1975-1979 and 1994-2001), and long-term changes between the 1970s and 1990s were derived by comparison. The data were binned relative to the dynamical tropopause to separate between UT and LS air masses. LS data were analysed using equivalent latitudes. In the UT, pronounced increases of 20-40% are found over the Middle East and South Asia in the spring and summer seasons. Increases are also found over Japan, Europe, and the eastern parts of the United States depending on season. LS ozone over northern mid- and high latitudes was found to be lower in the 1990s compared to the 1970s in all seasons of the year. In addition, a comparison with long-term changes deduced from ozonesondes is presented. The early 1970s European Brewer-Mast (BM) sonde data agree with GASP within the range of uncertainty (UT) or measured slightly less ozone (LS). In contrast, the 1990s BM sensors show consistently and significantly higher UT/LS ozone values than MOZAIC. This unequal behaviour of aircraft/sonde comparisons in the 1970s and 1990s leads to differences in the estimated long-term changes over Europe: while the comparison between GASP and MOZAIC indicates ozone changes of -5% to 10% over Europe, the sondes suggest a much larger increase of 10%-35% depending on station and season, although statistical significance is not conclusive due to data sample limitations. In contrast to the BM sondes, the Electrochemical Cell (ECC) sonde at Wallops Island, USA, measured higher UT ozone than both GASP and MOZAIC. Hence, long-term changes from GASP/MOZAIC agree within the range of uncertainty with the changes deduced from Wallops Island.

  5. 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

  6. 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

  7. Dual colour fluorescence in situ hybridization to paraffin-embedded samples to deduce the presence of the der(X)t(X;18)(p11.2;q11.2) and involvement of either the SSX1 or SSX2 gene: a diagnostic and prognostic aid for synovial sarcoma.

    PubMed

    Lu, Y J; Birdsall, S; Summersgill, B; Smedley, D; Osin, P; Fisher, C; Shipley, J

    1999-03-01

    Identification of the t(X;18)(p11.2;q11.2) and the fusion gene products, SYT-SSX1 and SYT-SSX2, associated with a high proportion of synovial sarcomas, has been shown to be a useful diagnostic aid. This study demonstrates the application of dual colour fluorescence in situ hybridization to paraffin-embedded samples to deduce the presence of the derivative X chromosome and also the position of the breakpoint on chromosome X at either the SSX1 or the SSX2 gene. This used region specific markers from chromosomes X and 18 and an optimized protocol involving microwave exposure. Novel and rapid scoring criteria were validated which circumvented potential problems of nuclear truncation and defining cell boundaries. This involved blind analysis of two negative sarcoma samples and three synovial sarcomas in which corresponding frozen material had been previously shown to have the translocation involving different SSX genes. Six new cases diagnosed as synovial sarcoma were also analysed; two monophasic and two biphasic case were deduced to have a breakpoint in the SSX1 gene, one monophasic case an SSX2 breakpoint, and one case did not show rearrangement of the region. The ability to analyse formalin-fixed, paraffin-embedded samples in this way has practical implications for aiding the diagnosis of difficult cases, recently ascribed prognostic relevance, and allows further retrospective studies to be carried out. The methodology is also applicable to the identification of other tumour specific translocations in paraffin-embedded material. PMID:10398111

  8. 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.

  9. 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

  10. Emission region size deduced from the AKR dynamical spectrum

    NASA Astrophysics Data System (ADS)

    Schreiber, R.

    2003-04-01

    Simple 3D ray tracing based on Calvert's (1981) formulas has been applied to the modeling of the AKR dynamical spectrum observed during the 20 minutes polar pass of FAST satellite (orbit 1761). General shape of the spectrum can be produced by AKR emission region spread along the auroral oval. Its longitudinal (MLT) and latitudinal (Invariant Latitude) dimensions correspond to the +/- 1 hour and +/- 2 degrees extent with respect to the FAST satellite source crossing position. Varying frequency boundaries of bright patches seen in the dynamical spectrum put the limit on the rays escape angles at the AKR source region. Escape angles measured with respect to the upward direction parallel to the magnetic field at the source region are confined within 60 - 90 degrees range.

  11. The laws of thermodynamics deduced from statistical mechanics

    NASA Astrophysics Data System (ADS)

    Diu, B.; Guthmann, C.; Lederer, D.; Roulet, B.

    Since the advent of statistical mechanics, the laws of thermodynamics are consequences of more fundamental postulates. Nevertheless, the logical link between statistical mechanics and thermodynamics is far from being precisely described in the literature, at an elementary level. The present paper tries to clarify this subject. It is necessary to recall some basic notions and results of statistical mechanics, but also the main definitions concerning thermodynamic transformations (which are partly ignored in too many cases). The laws of thermodynamics, especially the second one, are then derived and analyzed in statistical terms, and the statistical meaning of heat and work is discussed. Depuis l'avènement de la mécanique statistique, les principes de la thermodynamique sont des conséquences de postulats plus fondamentaux. Pourtant, le lien logique entre mécanique statistique et thermodynamique est loin d'etre explicité de façon précise, à un niveau élémentaire, dans la littérature. L'article que voici tente de clarifier le sujet. Il s'avère nécessaire de rappeler quelques notions et résultats de base en mécanique statistique, mais aussi les principales définitions (trop souvent ignorées pour certaines d'entre elles) relatives aux transformations thermodynamiques. Les principes de la thermodynamique, en particulier le second, sont ensuite démontrés et analysés en termes statistiques, et l'interprétation statistique de la chaleur et du travail est discutée.

  12. Tracer transport by the diabatic circulation deduced from satellite observations

    NASA Technical Reports Server (NTRS)

    Solomon, S.; Kiehl, J. T.; Garcia, R. R.; Grose, W.

    1986-01-01

    Nimbus-7 sensor data were used to track the diabatic circulation in the stratosphere to study the advective transport of CH4 and N2O as tracer species. Advective transport by the mean circulation was found to be a function of the temperature field and associated deviations from radiative equilibrium. A photochemical model was applied to account for the disappearance of the tracer species from the stratosphere. Comparisons between the SAMS data and modeling on the basis of the chemical loss rates of the tracers and the LIMS circulation data showed that the model predictions underestimated the resident abundances, although the global distributions and circulations exhibited a good match.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Clusterization of water molecules as deduced from statistical mechanical approach

    NASA Astrophysics Data System (ADS)

    Krasnoholovets, Volodymyr

    2004-12-01

    Using the methods of statistical mechanics we have shown that a homogeneous water network is unstable and spontaneously disintegrates to the nonhomogeneous state (i.e. peculiar clusters), which can be treated as an ordinary state of liquid water. The major peculiarity of the concept is that it separates the paired potential into two independent components—the attractive potential and the repulsive one, which in turn should feature a very different dependence on the distance from the particle (a water molecule in the present case). We choose the interaction potential as a combination of the ionic crystal potential and the vibratory potential associated with the elastic properties of the water system as a whole. The number ℵ of water molecules that enters a cluster is calculated as a function of several parameters, such as the dielectric constant, the mass of a water molecule, the distance between nearest molecules, and the vibrations of nearest molecules in their nodes. The number of H2O molecules that comprise a cluster is estimated as about ℵ ≈ 900, which agrees with the available experimental data.

  19. Inter-relationships of haplosporidians deduced from ultrastructural studies.

    PubMed

    Hine, P M; Carnegie, R B; Burreson, E M; Engelsma, M Y

    2009-02-25

    We reviewed papers reporting haplosporidian ultrastructure to compare inter-relationships based on ultrastructure with those based on molecular data, to identify features that may be important in haplosporidian taxonomy, and to consider parasite taxonomy in relation to host taxonomy. There were links between the following: (1) the plasmodia of an abalone parasite, Haplosporidium nelsoni and Urosporidium crescens in the release of haplosporosomes; (2) H. costale and H. armoricanum in haplosporosome shape and presence and shape of Golgi in spores; (3) basal asporous crustacean haplosporidians which form haplosporosomes from formative bodies (FBs) in vegetative stages--H. nelsoni, which forms haplosporosomes from FBs in plasmodial cytoplasm, and H. louisiana, Minchinia spp. and Bonamia perspora, which form haplosporosomes from FBs in spores; (4) crustacean haplosporidians, Bonamia spp. and M. occulta in the predominance of uni- and binucleate stages; and (5) lipid-like vesicles in sporoplasms of H. costale, H. armoricanum, H. lusitanicum, H. pickfordi, H. montforti, and B. perspora. In general, these relationships reflect phylogenies based on molecular studies. As well as spore form and ornamentation, haplosporogenesis in spores appears to be taxonomically important. Parasite and host taxonomy were linked in the infection of lower invertebrates by Urosporidium spp., the infection of oysters by Bonamia spp., and of molluscs by Minchinia spp. Haplosporidium spp. are patently an artificial, paraphyletic group probably comprising many taxa. Consequently, the taxonomy of haplosporidians needs a thorough revision. PMID:19402456

  20. 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.

  1. 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.

  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 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:24358025

  8. 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.

  9. 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.

  10. Shell structure of potassium isotopes deduced from their magnetic moments

    NASA Astrophysics Data System (ADS)

    Papuga, J.; Bissell, M. L.; Kreim, K.; Barbieri, C.; Blaum, K.; De Rydt, M.; Duguet, T.; Garcia Ruiz, R. F.; Heylen, H.; Kowalska, M.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Rajabali, M. M.; Sánchez, R.; Smirnova, N.; Somà, V.; Yordanov, D. T.

    2014-09-01

    Background: Ground-state spins and magnetic moments are sensitive to the nuclear wave function, thus they are powerful probes to study the nuclear structure of isotopes far from stability. Purpose: Extend our knowledge about the evolution of the 1/2+ and 3/2+ states for K isotopes beyond the N =28 shell gap. Method: High-resolution collinear laser spectroscopy on bunched atomic beams. Results: From measured hyperfine structure spectra of K isotopes, nuclear spins, and magnetic moments of the ground states were obtained for isotopes from N =19 up to N =32. In order to draw conclusions about the composition of the wave functions and the occupation of the levels, the experimental data were compared to shell-model calculations using SDPF-NR and SDPF-U effective interactions. In addition, a detailed discussion about the evolution of the gap between proton 1d3/2 and 2s1/2 in the shell model and ab initio framework is also presented. Conclusions: The dominant component of the wave function for the odd-A isotopes up to K45 is a π1d3/2-1 hole. For K47,49, the main component originates from a π2s1/2-1 hole configuration and it inverts back to the π1d3/2-1 in K51. For all even-A isotopes, the dominant configuration arises from a π1d3/2-1 hole coupled to a neutron in the ν1f7/2 or ν2p3/2 orbitals. Only for K48, a significant amount of mixing with π2s1/2-1⊗ν(pf) is observed leading to a Iπ=1- ground state. For K50, the ground-state spin-parity is 0- with leading configuration π1d3/2-1⊗ν2p3/2-1.

  11. Deducing a Canopy Reduction Factor for Biogenic Emission Modeling

    NASA Astrophysics Data System (ADS)

    Karl, T.; Guenther, A.

    2005-12-01

    The IPCC 2001 report states that "there is a serious discrepancy between the isoprene emissions derived by [Guenther et al., 1995] based on a global scaling of emission" . and "highlights a key uncertainty in global modeling of highly reactive trace gases: namely, what fraction of primary emissions escapes immediate reaction/removal in the vegetation canopy or immediate boundary layer and participates in the chemistry on the scales represented by global models?". A recent modeling study [Makar et al., 1999] suggested that up to 40 % of isoprene can be lost due to in-canopy chemistry. However, up to date only limited experimental datasets have been used to constrain canopy reduction factors (CRF) . Based on our recent CELTIC (Chemistry, Emission, Loss and Transformation in Canopies) initiative we measured VOC emissions above tropical, deciduous and evergreen ecosystems. In this paper we infer a new parameterization for modeling a CRF due to chemically short-lived biogenic compounds of the form: CRF = h/(a x u* x tau +h) (h: canopy height [m], u*: friction velocity [m/s], tau: lifetime [s], a: dimensionless fitting parameter a=1.5 +/- 0.1). This parameterization is based on results obtained during recent field studies in combination with a random walk model. For isoprene we find that the CRF is on the order of 2-5 % for typical daytime conditions. Loss rates for isoprene are somewhat smaller but within the range of previously reported values [Strong et al., 2004], [Stroud et al., 2005]. Many reactive terpenoid compounds (such as beta-caryophellene) with lifetimes on the order of minutes can be substantially reduced (e.g. up to 60-80 %) before they escape the forest canopy. References: Guenther, A., C.N. Hewitt, D. Erickson, and R. Fall, A global model of natural volatile organic compound emissions, Journal of geophysical research, 100 (D/5), 8873-8892, 1995. Makar, P., J. Fuentes, D. Wang, R. Staebler, and H. Wiebe, Chemical processing of biogenic hydrocarbons within and above a temperate deciduous forest, J. geophys. res., 104 (D3), 3581-3603, 1999. Strong, C., J.D. Fuentes, and D. Baldocchi, Reactive hydrocarbon flux footprints during canopy senescence, Agricultural and Forest Meteorology, 127 (3-4), 159-173, 2004. Stroud, C., P.A. Makar, T. Karl, A. Guenther, C. Geron, A.A. Turnipseed, E. Nemitz, B. Baker, M. Potosnak, J.D. Fuentes, H. McCarthy, and R. Oren, Role of Canopy-Scale Photochemistry in Modifying Biogenic-Atmosphere Exchange of Reactive Terpene Species: Results from the CELTIC Field Study, Journal of Geophysical Research-Atmospheres, in press, 2005.

  12. 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

  13. 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…

  14. Low Temperature Physics at Yale in the late 30's through the early 50's

    NASA Astrophysics Data System (ADS)

    Wheeler, Robert

    2006-03-01

    The low temperature program at Yale was initiated by C. T. Lane (1904-1991) in the fall of 1937 when he was appointed to the teaching staff as an instructor in the department of Physics. Following his doctorate from McGill in 1929 he investigated the magnetic susceptibilities of ``soft'' metals supported by the National Research Council of Canada, the Commissioners of the 1851 Exhibition and a Sterling Fellowship at Yale. Arranged by Louis McKeehan, with 5000 from the new George Sheffield research fund, he started the construction of a Kapitza type helium liquefier. The machine was largely completed in the fall of 1939, yet liquid helium was not made until early December 1940 due to the need for extensive on line purification of the gas. Returning in 1945 from war research, Lane and Henry A. Fairbank (Ph.D 1944) continued the metals work along with new thrusts into Second Sound , properties of helium^ three impurities in liquid helium and starting in the 50's on rotating He II. In 1933 both Lane and Onsager were awarded Sterling Fellowships, which initiated a stimulating experimental- theoretical exchange continuing until they both retired. The best-known example was the rediscovery at Yale of the deHaas-van Alphen effect, previously observed only in bismuth, in zinc; where upon Onsager and his students provided new insights into our understanding of the Fermi surface of metals. With the development of new instrumentation one observed vast changes in experimental style during this period. The evolution of the production of liquid helium from Lane's device though the Collins machine to the commodity business of today now makes experiments of huge size and importance possible.

  15. 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

  16. 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

  17. Nucleotide and deduced amino acid sequences of the lacR, lacABCD, and lacFE genes encoding the repressor, tagatose 6-phosphate gene cluster, and sugar-specific phosphotransferase system components of the lactose operon of Streptococcus mutans.

    PubMed Central

    Rosey, E L; Stewart, G C

    1992-01-01

    The complete nucleotide sequences of lacRABCDF and partial nucleotide sequence of lacE from the lactose operon of Streptococcus mutans are presented. Comparison of the streptococcal lac determinants with those of Staphylococcus aureus and Lactococcus lactis indicate exceptional protein and nucleotide identity. The deduced polypeptides also demonstrate significant, but lower, sequence similarity with the corresponding lactose proteins of Lactobacillus casei. Additionally, LacR has sequence homology with the repressor (DeoR) of the Escherichia coli deoxyribonucleotide operon, while LacC is similar to phosphokinases (FruK and PfkB) from E. coli. The primary translation products of the lacRABCDFE genes are polypeptides of 251 (M(r) 28,713), 142 (M(r) 15,610), 171 (M(r) 18,950), 310 (M(r) 33,368), 325 (M(r) 36,495), 104 (M(r) 11,401), and 123 (NH2-terminal) amino acids, respectively. As inferred from their direct homology to the staphylococcal lac genes, these determinants would encode the repressor of the streptococcal lactose operon (LacR), galactose-6-phosphate isomerase (LacA and LacB), tagatose-6-phosphate kinase (LacC), tagatose-1,6-bisphosphate aldolase (LacD), and the sugar-specific components enzyme III-lactose (LacF) and enzyme II-lactose (LacE) of the S. mutans phosphoenolpyruvate-dependent phosphotransferase system. The nucleotide sequence encompassing the S. mutans lac promoter appears to contain repeat elements analogous to those of S. aureus, suggesting that repression and catabolite repression of the lactose operons may be similar in these organisms. Images PMID:1400164

  18. Measurement of proton capture cross sections relevant to rp process with Coulomb dissociation

    SciTech Connect

    Togano, Y.

    2010-08-12

    We have studied proton capture reactions on unstable proton-rich nuclei relevant to rapid proton-capture (rp) process using a Coulomb dissociation method. Using this method, three stellar reactions, {sup 22}Mg(p, {gamma}){sup 23}Al, {sup 26}Si(p, {gamma}){sup 27}P, and {sup 30}S(p, {gamma}){sup 31}Cl were studied at RIKEN Nishina Center. The radiative widths of the first excited state in {sup 23}Al and {sup 27}P, which are relevant to the stellar reactions, were obtained. We discuss the details of the Coulomb dissociation the astrophysical implications obtained from our studies.

  19. Deformation of the Paleozoic metamorphic basement in Tanumé-Pichilemu (34°30' S), Central Chile

    NASA Astrophysics Data System (ADS)

    Palape, C.; Herve, F.; Heredia, N.; Martín-González, F.

    2014-12-01

    We present a new geodynamic evolution for the late Paleozoic accretionary complex of the Chilean coast, located between Tanumé-Pichilemu villages. The accretionary complex has been interpreted as paired metamorphic belt, with continuous exposures along the Coastal Cordillera between 34° and 38°S, was formed during subduction of the paleo-Pacific plate against the southwestern margin of Gondwana. This complex consists of two tectonometamorphic units: (i) a basally accreted HP/LT, the Western Series, formed by metabasites, metacherts, greenschists, blue-schists and marbles, with peak P-T conditions of 7-11 kbar and 350-400°C, that are superimposed on (ii) the frontally accreted Eastern Series, mainly formed by metaturbidites and deformed in HT/LP metamorphic conditions, coeval with the emplacement of the Pennsylvanian Coast Range batholith. The structures observed in the Tanumé-Pichilemu transect has been affected by three deformation episodes related with Gondwanan orogeny (D1, D2, D3), developed in late Carboniferous-Early Permian times. In the Eastern Series, D1 is associated to recumbent isoclinals folds with NW trend and associated (S1) cleavage. The D2 event is related to SW vergent folds which are part of an antiform-synform pair, developing an axial plane cleavage (S2) that dips 30° to the NE. This regional tectonic foliation S2 has intertectonic garnets porphyroblasts. In the Western Series, the first episode (D1) is represented by a foliation (S1) formed under HP-LT metamorphic conditions and preserved in syn-D2 garnet and albite porphyroblast. A NE directed reverse ductile fault system (D2), developed under pressure decreasing conditions, overlaps the HP-LT Western Series, formed about 15-25 km depth, above the shallow HT/LP Eastern Series. In this context the D2 of the Eastern Series are formed previously to D2 episode of the Western Series. The third deformative event D3 is linked to west-verging kilometric-scale antiform, related to a fragile reverse fault that thrust the Eastern Series above the Western Series. This episode is associated with a S3 cleavage. The D3 reverse fault presents a minor sinestral movement, probably related to the Andean orogenic cycle. This work has been supported by FONDECYT grant 1130227, and TORANDES (CGL2012-38396-C03) Spanish I+D+i Plan.

  20. 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.

  1. 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.

  2. Transport in the Region of the Subtropical Jet Deduced From WB-57 Measurements and Mesoscale Modeling

    NASA Astrophysics Data System (ADS)

    Ray, E.; Ray, E.; Rosenlof, K. H.

    2001-12-01

    Recent WB-57 missions have provided a wealth of long-lived tracer and aerosol measurements in the upper troposphere and lower stratosphere. In this study we use in situ water vapor, ozone and meteorological measurements as well as vertical sounding data to investigate transport in the region of the subtopical jet. In addition, mesoscale model simulations from the NCAR MM5 are utilized to attempt to reproduce the observations and help determine possible mechanisms of transport. We focus on the flight of May 7, 1998 since it has several interesting features in the measurements taken as the flight crossed a jet exit region at roughly the 370 K level. On the tropical side of the jet, low water vapor and relatively high ozone mixing ratios were measured suggesting the air in this region had stratospheric characteristics. Yet according to MM5 output this region is well within the troposphere. Within the jet the water vapor mixing ratios are highly variable, with some mixing ratios higher than those measured on either side of the jet at the same isentropic level. This suggests that perhaps there was more vertical mixing within the jet than on either side of the jet. A third interesting feature in the measurements is seen several hundred km north of the jet just as the plane began to rise in altitude. Between 370-390K the water vapor increased sharply and the ozone decreased sharply at the same time the MTP instrument indicated the tropopause level had risen from 345 K to 370 K in less than 50 km. This feature is highly suggestive of a small filament of upper tropospheric air which has been transported to the north side of the jet. Each of these features is compared to MM5 output and trajectory analyses.

  3. 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.

  4. The osmium isotopic composition of convecting upper mantle deduced from ophiolite chromites

    NASA Astrophysics Data System (ADS)

    Walker, Richard J.; Prichard, Hazel M.; Ishiwatari, Akira; Pimentel, Márcio

    2002-01-01

    Chromites separated from the upper mantle or lower crustal portions of 18 ophiolites ranging in age from 900 Ma to 50 Ma are examined for Re-Os isotopic systematics. The ophiolites include both MORB and back arc types, although most are from supra-subduction zone (SSZ) settings. The chromites are robust indicators of the initial Os isotopic compositions of the systems sampled. There is very limited range in calculated initial γ Os values, with the entire group averaging +1.31. Least squares linear regression of the age of chromite formation (in Ga) versus initial 187Os/ 188Os of a filtered suite yields a slope of -0.0058±0.0019 (2σ) and a present day intercept of 0.12809±0.00085 (2σ), equivalent to a γ Os value of +0.9±0.6. Of the suite of 51 samples analyzed, 68% lie within ±1% of this evolution trajectory. Although most of the samples formed in SSZ environments, there is little evidence to suggest modification of the mantle Os isotopic composition via radiogenic melts or fluids derived from subducting slabs. The ophiolite data are interpreted as representative of the convecting upper mantle and suggest that the present isotopic composition of the convecting upper mantle averages approximately 1.2% less radiogenic than the estimated minimum composition of the primitive upper mantle of 0.1296±8 (Meisel et al., 2001). The most likely explanation for the difference is the formation, subduction and isolation of some portion of the mafic oceanic crust. Using models based on the assumption that the convecting upper mantle comprises 50% of the total mass of the mantle, and that the average isolation period for subducted oceanic crust is 1.5 to 2.0 Ga, it is estimated that approximately 2 to 3% of the total mass of the mantle is composed of subducted mafic oceanic crust that remains isolated from the convecting upper mantle. Because the isotopic compositions of the DMM and PUM overlap within uncertainties, however, the results do not require any isolated slab component.

  5. 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

  6. 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.

  7. Two sulphur isotope provinces deduced from ores in the Mount Isa Eastern Succession, Australia

    NASA Astrophysics Data System (ADS)

    Davidson, G. J.; Dixon, G. H.

    1992-01-01

    The sulphur isotopic characteristics of ore deposits in the Australian Mount Isa Eastern Succession are not well known, unlike those of the Western Succession. In this study new detailed analyses are provided for recently discovered Eastern Succession mineralisation, such as the Starra and Osborne BIF-hosted Cu-Au ores, the Dugald River sediment-hosted Pb-Zn prospect, and four vein-hosted Cloncurry-style Cu±Au deposits (Hampden, Mt Elliot/Swan, Mt Cobalt, and the Answer Mine). All of the deposits of the Eastern Succession have δ34Ssulphide between -8 and +9%., regardless of their genesis. Empirically a moderate (δ34S range averaging close to 0%. characterises Starra-style Cu-Au and Pegmont Pb-Zn BIF ores, whereas shear and vein-style Cu mineralisation populations are tighter and do not average close to 0%. This is a particularly surprising result for Dugald River, where a larger isotopic variation more typical of stratiform sediment-hosted Pb-Zn ores in the region might have been expected. By comparison, Western Succession stratiform Pb-Zn and vein-style Cu deposits span a huge range of-15 to 51%. Large sulphur isotope ranges typify sulphate evaporite or organic sulphur-rich sedimentary successions. The lack of such variation in the Eastern Succession in turn suggests that primary evaporite sequences there were halite-dominated but sulphate-poor, and/or contained only limited volumes of organic-sulphur-rich sediment. Eastern Succession sequences were therefore less likely hosts for giant stratiform Pb-Zn deposits, because of their paucity of sulphur, although local sulphur sources permitted small deposits such as Dugald River to develop. Sedimentary conditions were more favourable for the development of sulphur-poor synsedimentary hydrothermal systems such as Starra, Osborne, and Pegmont, although sulphur isotope evidence is equivocal about the origin of these. Epigenetic deposits close to the Williams Batholith (Mt Dore, Hampden) owe their clustering around 0%. to their granitic fluid source.

  8. A 350 Year Cloud Cover Reconstruction Deduced from Caribbean Coral Proxies

    NASA Astrophysics Data System (ADS)

    Winter, Amos; Sammarco, Paul; Mikolajewicz, Uwe; Jury, Mark; Zanchettin, Davide

    2015-04-01

    Clouds are a major factor contributing to climate change with respect to a variety of effects on the earth's climates, primarily radiative effects, amelioration of heating, and regional changes in 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 is so short that it is difficult to discern any temporal trends. The skeletons of scleractinian corals are considered to contain among the best records of high-resolution (sub-annual) environmental variability in the tropical and sub-tropical oceans. 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. Zooxanthellate hermatypic corals in tropical and sub-tropical seas precipitate CaCO3 skeletons as they grow. This growth is made possible through the manufacture of CaCO3 crystals, 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, δ13C 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 and present a new reconstruction of cloud cover over the Caribbean Sea that extends back to the year 1760. We will show that there is good agreement between the main features of our coral proxy record of cloud cover and of reanalysis and climate simulations for the same time period.

  9. Crustal structure of the Hecataeus Rise (eastern Mediterranean) deduced by marine gravity and marine magnetic modelling

    NASA Astrophysics Data System (ADS)

    Dehghani, Ali

    2016-04-01

    In the year 2010 extensive geophysical researches were carried out in the area of Hecataeus Rise using the German research vessel Maria S. Merian. Beside the bathymetry, refraction and reflection seismic data, marine gravity and marine magnetic data were acquired during this cruise. The result of the research along one Wide-Angle reflection/refraction seismic line of this cruise is published 2015 by K. Welford et al.. Based on interpretation of reflection seismic and bathymetry data across the Hecataeus Rise, S. Reiche published 2015 the crustal structure and bathymetric features along some seismic profiles of this cruise. The focus of this work is to use the available sediments and crustal structures inferred by seismic information together with real marine gravity and marine magnetic data in order to produce gravity and magnetic 2-D models along all seismic profiles. While Welford et al. used the altimetry gravity data and magnetic data from EMAG3 database for their modelling, the real gravity and magnetic data measured exactly along the seismic profiles will be used in this work. The advantage of the real marine gravity and real marine magnetic data used for the modelling is that they have higher accuracy in the values as well as in the positions. Furthermore, Welford et al. calculated the gravity and Magnetic models along some seismic profiles, while in this work the result of gravity and magnetic modelling along all seismic profiles of this cruise will be presented. The marine gravity and marine magnetic data along all seismic profiles were recorded continuously. The accuracy of marine gravity data is about ± 1 mGal, while the accuracy of Marine magnetic data is in the range of ± 3 nT. The results of 2-D gravity and magnetic modelling will be presented and discussed in this work.

  10. 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.

  11. 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.

  12. 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

  13. Origins of light trans-Fe and r-process elements deduced from Galactic chemical evolution

    NASA Astrophysics Data System (ADS)

    Ishimaru, Yuhri; Arao, Sachie; Wanajo, Shinya; Prantzos, Nicolas

    2014-09-01

    Compact binary mergers are suggested to be the major site of the r-process elements by recent hydrodynamical and nucleosynthesis studies. It has been pointed out, however, that estimated long lifetimes of compact binaries are in conflict with the presence of large scatters in r-process elements of very metal-poor stars (MPS). To resolve this problem, we examine the role of compact binary mergers in the early Galactic chemical evolution on the assumption that our Galactic halo was formed from clusterings of sub-halos. We find that star-to-star scatters of [r/Fe] in MPS can be well explained with this scenario. Observations of MPS also show large enhancement of Sr relative to Ba, suggesting a distinct site of light trans-Fe elements. Recent nucleosynthesis studies show that electron-capture supernovae (ECSNe) can produce heavy elements up to Zr (Wanajo et al. 2011). Using our inhomogeneous chemical evolution model, we discuss that ECSNe can explain observed enhancement of Zn in MPS as well as of Sr, Y, and Zr.

  14. Temporal Changes in Eruption Dynamics at Tungurahua Volcano Deduced from Infrasonic Measurements, June 2009

    NASA Astrophysics Data System (ADS)

    Parmigiani, A.; Chojnicki, K. N.; Parcheta, C. E.; Christensen, B.; Marcillo, O. E.; Johnson, J. B.

    2009-12-01

    Tungurahua volcano (1.45S, 78.43W, 5023m), located in the heart of the Andes and within Ecuador's Eastern Cordillera, is the most active populated volcano in the region. Since 1999 Tungurahua has affected the communities on its western flanks with a continuous cycle of Strombolian and Vulcanian activity (VEI 0 and 1) that climaxed on August 16th, 2006 with a VEI 2 event. Continuous tracking of Tungurahua eruptive activity presents a challenge as inclement weather often prevents direct observation of eruptive activity and strong volcanic tremor often masks seismic signals associated with explosive events. Infrasound signals have thus proven invaluable in identifying explosive activity and estimating erupted flux at Tungurahua. During a 10-day-long campaign in June 2009, two temporary arrays (a seismo-acoustic array at 6 km and an acoustic array at 11.5 km) were installed to provide insight into temporal changes in eruption dynamics and near-vent conditions. During the deployment interval, explosive activity was dominated by impulsive infrasonic events. Time-lapse camera footage confirmed Strombolian-style eruptions associated with 77 impulsive events, recorded at an average rate of 8 explosions per day. Columns with variable ash content rose from 2-6 km above the crater rim and incandescent blocks were seen to rise up to 800 meters in altitude during some events. Corresponding infrasonic waveforms had peak pressures as great as 74 Pa at 6 km from the vent and the primary pulses lasted 6-10s. Waveform shapes often displayed high levels of self-similarity in contrast to their seismic counterparts, which persisted up to 40-50s and were emergent and dis-similar. Acoustic array beam-forming and semblance analyses have been employed to decompose the infrasonic wave field, verify volcano acoustic sources, construct a volcano acoustic catalogue, and identify apparent variations in the lateral position of the vent(s). The ratio of elastic energy propagated into the atmosphere relative to energy into the earth is also studied and shown to be variable, suggesting a narrow, dynamic conduit whose geometry and/or eruption mechanism changes between eruption pulses. Finally, mass flux is determined from infrasound N-waves at the beginning of the most vigorous cannon-shot eruptions. This analysis provides insight into the volume of gas that is explosively released at the onset of a discrete explosion.

  15. Ozone profiles and chemical loss rates in the tropical stratosphere deduced from backscatter ultraviolet measurements

    NASA Technical Reports Server (NTRS)

    Frederick, J. E.; Hays, P. B.; Guenther, B. W.; Heath, D. F.

    1978-01-01

    Analysis of data obtained by the backscatter ultraviolet (BUV) experiment on the Atmosphere Explorer E satellite has provided equatorial ozone mixing ratio profiles for equinox and solstice conditions. The combination of these results with a pure oxygen chemical model yields the rate of odd oxygen loss due to the sum of the odd hydrogen, nitrogen, and chlorine cycles. Use of recent mid-latitude stratospheric measurements of HO(x), NO(x), and ClO(x) with the BUV data provides an independent calculation of the catalytic loss. Below 45 km the agreement between the two sets of loss rates is satisfactory. At higher altitudes the odd hydrogen cycle provides far more O(x) loss than can be tolerated by the BUV measurements if the photodissociation of O2 is the only source and has the currently accepted magnitude. The results suggest either a tropical HO(x) concentration smaller than is now believed or the presence of a very large source of odd oxygen in the upper stratosphere and lower mesosphere.

  16. 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.

  17. 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.

  18. 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.

  19. Deducing Shape of Anisotropic Particles in Solution from Light Scattering: Spindles and Nanorods

    NASA Astrophysics Data System (ADS)

    Tsuper, Ilona; Terrano, Daniel; Streletzky, Kiril A.; Dement'eva, Olga V.; Semyonov, Sergey A.; Rudoy, Victor M.

    Depolarized Dynamic Light Scattering (DDLS) enables to measure rotational and translational diffusion of nanoparticles suspended in solution. The particle size, shape, diffusion, and interactions can then be inferred from the DDLS data using various models of diffusion. Incorporating the technique of DDLS to analyze the dimensions of easily imaged elongated particles, such as Iron (III) oxyhydroxide (FeOOH) Spindles and gold Nanorods, allows testing of the models for rotational and translational diffusion of elongated particles in solution. This, in turn, can help to better interpret DDLS data on hard-to-image anisotropic wet systems such as micelles, microgels, and protein complexes. This study focused on FeOOH Spindles and gold nanorod particles. The light scattering results on FeOOH analyzed using the basic model of non-interacting prolate ellipsoids yielded dimensions within 17% of the SEM measured dimensions. The dimensions of gold nanorod obtained from the straight cylinder model of DDLS data provided results within 25% of the sizes that were obtained from TEM. The nanorod DDLS data was also analyzed by a spherocylinder model.

  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. Plasma drifts deduced from resonance cone asymmetries: II. Evaluation of COREX data

    NASA Astrophysics Data System (ADS)

    Piel, A.; Rohde, V.; Thiemann, H.; Oyama, K. I.

    The data from the COREX instrument are discussed with respect to non-reciprocities in resonance cones for opposing wave propagation directions. The shift of the maxima has a different symmetry from the case of field aligned drifts. Using a generalized drift model the magnitude and direction of the drift is evaluated. Velocities of the order of up to 38 km/s are found. The drift direction is nearly perpendicular to the magnetic field.

  2. Mining a Sea of Data: Deducing the Environmental Controls of Ocean Chlorophyll

    PubMed Central

    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

  3. 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 .

  4. Properties of solar coronal active regions deduced from X-ray line spectra

    NASA Astrophysics Data System (ADS)

    McKenzie, D. L.

    1987-11-01

    Spectra from the SOLEX B RAP spectrometer have been used to analyze the temperature and density structure of over 100 nonflaring solar active regions. Density measurements that used the R ratio of O VII indicated that few regions have electron densities higher than ≡3×109cm-3. In a few cases, flare-productive regions had measured densities approximately twice this high. Temperature-sensitive line ratios in the helium-like ions O VII, Ne IX, and Mg XI were used to decude the general properties of the differential emission-measure function B(T) for nonflaring regions. B(T) falls off with increasing temperature above a peak temperature that is almost always lower than Tm(O VII) = 1.8×106K.

  5. 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.

  6. 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.

  7. Coronal structures deduced from photospheric magnetic field and He I lambda 10830 observations

    NASA Technical Reports Server (NTRS)

    Harvey, Karen L.

    1995-01-01

    The National Solar Observatory synoptic program provides an extensive and unique data base of high-resolution full-disk observations of the line-of-sight photospheric magnetic fields and of the He I lambda 10830 equivalent width. These data have been taken nearly daily for more than 21 years since 1974 and provide the opportunity to investigate the behavior of the magnetic fields in the photosphere and those inferred for the corona spanning on the time scales of a day to that of a solar cycle. The intensity of structures observed in He I lambda 10830 are strongly modulated by overlying coronal radiation; areas with low coronal emission are generally brighter in He I lambda 10830, while areas with high coronal emission are darker. For this reason, He I lambda 10830 was selected in the mid-1970's as way to identify and monitor coronal holes, magnetic fields with an open configuration, and the sources of high-speed solar wind streams. The He I lambda 10830 spectroheliograms also show a wide variety of other structures from small-scale, short-lived dark points (less than 30 arc-sec, hours) to the large-scale, long-lived two 'ribbon' flare events that follow the filament eruptions (1000 arc-sec, days). Such structures provide clues about the connections and changes in the large-scale coronal magnetic fields that are rooted in concentrations of magnetic network and active regions in the photosphere. In this paper, what observations of the photospheric magnetic field and He I lambda 10830 can tell us about the short- and long-term evolution of the coronal magnetic fields will be discussed, focussing on the quiet Sun and coronal holes. These data and what we infer from them will be compared with direct observations of the coronal structure from the Yohkoh Soft X-ray Telescope.

  8. Dipole-Strength Distributions up to the Giant Dipole Resonance Deduced from Photon Scattering

    NASA Astrophysics Data System (ADS)

    Schwengner, R.; Rusev, G.; Benouaret, N.; Beyer, R.; Dönau, F.; Erhard, M.; Grosse, E.; Junghans, A. R.; Kosev, K.; Klug, J.; Nair, C.; Nankov, N.; Schilling, K. D.; Wagner, A.

    2008-04-01

    Dipole-strength distributions up to the neutron-separation energies of the even-mass Mo isotopes from 92Mo to 100Mo and of the N = 50 isotones 88Sr, 89Y, 90Zr have been investigated in photon-scattering experiments using the bremsstrahlung facility at the superconducting electron accelerator ELBE of the Forschungszentrum Dresden-Rossendorf. A measurement using polarised bremsstrahlung impinging on 88Sr revealed that all resolved transitions with energies greater than 6 MeV in this nuclide except for one are E1 transitions. The intensity distributions obtained from the measured spectra after a correction for detector response and a subtraction of atomic background in the target contain a continuum part in addition to the resolved peaks. It turns out that the dipole strength in the resolved peaks amounts to about 30% of the total dipole strength while the continuum contains about 70%. In order to estimate the distribution of inelastic transitions and to correct the ground-state transitions for their branching ratios simulations of γ-ray cascades were performed. The photoabsorption cross sections obtained in this way connect smoothly to (γ, n) cross sections and give novel information about the strength on the low-energy tails of the Giant Dipole Resonances below the neutron-separation energies. The experimental cross sections are compared with predictions of a Quasiparticle-Random-Phase Approximation in a deformed basis. The calculations describe the experimentally observed increase of the dipole strengths with increasing neutron number of the Mo isotopes as a consequence of increasing nuclear deformation.

  9. Climatological aspects of aerosol physical characteristics in Tunisia deduced from sun photometric measurements.

    PubMed

    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

  10. 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.