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Sample records for superexchange interactions occurred

  1. The superexchange interactions in mixed Co-Fe ludwigite

    Energy Technology Data Exchange (ETDEWEB)

    Kazak, N.V., E-mail: nat@iph.krasn.r [L.V. Kirensky Institute of Physics, SB of RAS, 660036, Akademgorodok 50-38, Krasnoyarsk (Russian Federation); Ivanova, N.B. [Siberian Federal University, 660074, Kirensky str. 26, Krasnoyarsk (Russian Federation); Krasnoyarsk State Agrarian University, 660049, Mira str. 90, Krasnoyarsk (Russian Federation); Bayukov, O.A; Ovchinnikov, S.G [L.V. Kirensky Institute of Physics, SB of RAS, 660036, Akademgorodok 50-38, Krasnoyarsk (Russian Federation); Vasiliev, A.D. [L.V. Kirensky Institute of Physics, SB of RAS, 660036, Akademgorodok 50-38, Krasnoyarsk (Russian Federation); Siberian Federal University, 660074, Kirensky str. 26, Krasnoyarsk (Russian Federation); Rudenko, V.V. [L.V. Kirensky Institute of Physics, SB of RAS, 660036, Akademgorodok 50-38, Krasnoyarsk (Russian Federation); Bartolome, J. [Instituto de Ciencia de Materiales de Aragon. CSIC-Universidad de Zaragoza abd Departamento de Fisica de la Materia Condensada, 50009 Zaragoza (Spain); Arauzo, A. [Servicio de Instrumentacion Cientifica-Area de Medidas Fisicas. Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Knyazev, Yu.V. [Siberian Federal University, 660074, Kirensky str. 26, Krasnoyarsk (Russian Federation)

    2011-03-15

    The crystal structure, cation distribution and exchange interactions in the Co{sub 2.25}Fe{sub 0.75}O{sub 2}BO{sub 3} ludwigite have been explored through X-ray diffraction, electrical resistivity, ac-susceptibility and Mossbauer effect measurements. The crystal data have shown that iron atoms occupy the most symmetric crystallographic sites Fe4 and Fe2. The complex magnetic behavior with two magnetic transitions near 70 and 115 K at low temperatures was found. The Mossbauer data have displayed the trivalent iron states only. The values of superexchange energies have been estimated for Co{sub 3}O{sub 2}BO{sub 3} and Co{sub 2.25}Fe{sub 0.75}O{sub 2}BO{sub 3} yielding a significant role of frustrations in the ludwigite magnetic system. Variable range Mott hopping conductivity law was proved to be valid in the wide temperature region, pointing out a localized character of charge carriers rather than collective. - Research Highlights: The high quality single crystals of Co{sub 2.25}Fe{sub 0.75}O{sub 2}BO{sub 3} ludwigite were synthesized. The orthorhombic crystal symmetry with P{sub bam} space group was found. The Fe{sup 3+} ions predominantly occupy the octahedral positions 2 and 4. The complex magnetic behavior and magnetic transitions at 70 and 115 K were found. The values of superexchange energies have been estimated.

  2. [Combined hopping-superexchange mechanism of charge transfer in DNA; a model with nearest interactions].

    Science.gov (United States)

    Lakhno, V D; Sultanov, V B

    2007-01-01

    In the framework of the earlier developed combined hopping-superexchange mechanism of charge transfer in DNA, a model with all nearest interactions between nucleobases is proposed. It is shown that the transfer rates for various types of nucleotide sequences calculated within this model are in a good agreement with experimental data.

  3. Mössbauer studies on cation distributions and superexchange interactions in Cu0.2Fe2.8O4

    Science.gov (United States)

    Kim, Sam Jin; Choi, Hyunkyung; Lim, Jung Tae; Kim, Chul Sung; Hahn, Eun Joo

    2016-02-01

    The cation distributions and the superexchange interactions of Cu0.2Fe2.8O4 have been studied by Mössbauer spectroscopy and X-ray diffraction. The crystal is found to have a cubic spinel structure with the lattice constant a 0 = 8.4007 ± 0.0004 ˚A. The Mössbauer spectra show line broadening in the octahedral ( B) site, which is interpreted by probability distribution of cations. The dominant superexchange interaction is found to be an antiferromagnetic intersublattice A- O- B superexchange interaction, and its strength is J A- B = -20.7 k B . The intrasublattice A- O- A superexchange interaction is also antiferromagnetic and its strength is J A- A = -9.3 k B . The weakest superexchange interaction is the ferromagnetic B-O-B interaction: J B- B = 0.7 k B . The Debye temperatures of the tetrahedral and the octahedral sites are found to be Θ A = 459 ± 5 K and Θ B = 351 ± 5 K, respectively.

  4. Pressure effect on the energy structure and superexchange interaction in undoped orthorhombic La2CuO4

    Science.gov (United States)

    Gavrichkov, Vladimir A.; Pchelkina, Zlata V.; Nekrasov, Igor A.; Ovchinnikov, Sergey G.

    2016-09-01

    We studied the pressure dependences of the electronic structure and superexchange interaction J(P) = JA - JB (where JA and JB are antiferromagnetic (AFM) and ferromagnetic (FM) contributions) in antiferromagnetic La214 under hydrostatic, uniaxial (along c-axial) 3% compressions and 1% in-plane compressions by the local density approximation with generalized tight-binding method (LDA + GTB cell approach). The changes in J(P) correlated with the experimentally known TC(P) dependence are in accordance with the relation dTC/dP = (∂TC/∂J)(∂J/∂P), where ∂TC/∂J ˜ 0.1. The in-plane pressure more effectively stabilizes the ground singlet two-hole state A1 than the simple hydrostatic pressure, its effect on J and TC is the largest. Within the same cell approach together with the superexchange interaction J(P), the valence band structure was calculated. Its changes with pressure clearly reproduce the k-distribution of the singlet and triplet quasi-particles over the Brillouin zone (BZ).

  5. Effect of super-exchange interaction on ground state magnetic properties of spin-dependent Falicov-Kimball model on a triangular lattice

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sant, E-mail: santkumar1210@gmail.com; Maitra, Tulika; Singh, Ishwar [Department of Physics, Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand (India); Yadav, Umesh K. [Center for Condensed Matter Theory, Indian Institute of Science, Bangalore-560012 (India)

    2015-06-24

    Ground state magnetic properties are studied by incorporating the super-exchange interaction (J{sub se}) in the spin-dependent Falicov-Kimball model (FKM) between localized (f-) electrons on a triangular lattice for half filled case. Numerical diagonalization and Monte-Carlo simulation are used to study the ground state magnetic properties. We have found that the magnetic moment of (d-) and (f-) electrons strongly depend on the value of Hund’s exchange (J), super-exchange interaction (J{sub se}) and also depends on the number of (d-) electrons (N{sub d}). The ground state changes from antiferromagnetic (AFM) to ferromagnetic (FM) state as we decrease (N{sub d}). Also the density of d electrons at each site depends on the value of J and J{sub se}.

  6. Effect of super-exchange interaction on ground state magnetic properties of spin-dependent Falicov-Kimball model on a triangular lattice

    Science.gov (United States)

    Kumar, Sant; Yadav, Umesh K.; Maitra, Tulika; Singh, Ishwar

    2015-06-01

    Ground state magnetic properties are studied by incorporating the super-exchange interaction (Jse) in the spin-dependent Falicov-Kimball model (FKM) between localized (f-) electrons on a triangular lattice for half filled case. Numerical diagonalization and Monte-Carlo simulation are used to study the ground state magnetic properties. We have found that the magnetic moment of (d-) and (f-) electrons strongly depend on the value of Hund's exchange (J), super-exchange interaction (Jse) and also depends on the number of (d-) electrons (Nd). The ground state changes from antiferromagnetic (AFM) to ferromagnetic (FM) state as we decrease (Nd). Also the density of d electrons at each site depends on the value of J and Jse.

  7. The symmetric and antisymmetric superexchange interactions in spin-Peierls system

    Institute of Scientific and Technical Information of China (English)

    Liu Hai-Lian; Wang Zhi-Guo; Yang Cheng-Quan; Huang Xian-Shan; Shi Yun-Long

    2007-01-01

    The influences of Dzyaloshinskii-Moriya (DM) interaction and Kaplan-Shekhtman-Entinwohlman-Aharony (KSEA) interaction on the dimerization of a spin-Peierls system are investigated theoretically by using the Lanczos numerical method. The ground state of the spin-Peierls system is still dimerized phase when both of the DM and the KSEA interactions have the same value with Heisenberg interaction. It is found that the KSEA interaction and uniform DM interaction are always against systemic dimerization, but the staggered DM interaction acts in favour of dimerization. Furthermore, the influences of the DM and the KSEA interactions are also studied in terms of the ground state index rate and the energy gap index rate of the dimerized Heisenberg system. The results show that the DM interaction makes the index rates larger, while the KSEA interaction makes them smaller.

  8. Tuning interaction in dinuclear ruthenium complexes : HOMO versus LUMO mediated superexchange through azole and azine bridges

    NARCIS (Netherlands)

    Browne, Wesley; Hage, R; Vos, Johannes G.

    2006-01-01

    In this review the interaction between metal centers in dinuclear complexes based on azole and azine containing bridging ligands is reviewed. The focus of the review is on the manner in which the interaction pathway can be manipulated by variations in the nature of both the direct bridging unit and

  9. Monte Carlo study of the double and super-exchange model with lattice distortion

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, J R; Vallejo, E; Navarro, O [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, 04510 Mexico D. F. (Mexico); Avignon, M, E-mail: jrsuarez@iim.unam.m [Institut Neel, Centre National de la Recherche Scientifique (CNRS) and Universite Joseph Fourier, BP 166, 38042 Grenoble Cedex 9 (France)

    2009-05-01

    In this work a magneto-elastic phase transition was obtained in a linear chain due to the interplay between magnetism and lattice distortion in a double and super-exchange model. It is considered a linear chain consisting of localized classical spins interacting with itinerant electrons. Due to the double exchange interaction, localized spins tend to align ferromagnetically. This ferromagnetic tendency is expected to be frustrated by anti-ferromagnetic super-exchange interactions between neighbor localized spins. Additionally, lattice parameter is allowed to have small changes, which contributes harmonically to the energy of the system. Phase diagram is obtained as a function of the electron density and the super-exchange interaction using a Monte Carlo minimization. At low super-exchange interaction energy phase transition between electron-full ferromagnetic distorted and electron-empty anti-ferromagnetic undistorted phases occurs. In this case all electrons and lattice distortions were found within the ferromagnetic domain. For high super-exchange interaction energy, phase transition between two site distorted periodic arrangement of independent magnetic polarons ordered anti-ferromagnetically and the electron-empty anti-ferromagnetic undistorted phase was found. For this high interaction energy, Wigner crystallization, lattice distortion and charge distribution inside two-site polarons were obtained.

  10. Influence of polaron effects on superexchange interaction. Isotopic shifts of T sub N , T sub c and T* in laminated copper oxides

    CERN Document Server

    Eremin, M V; Larionov, I A; Terzi, A V

    2002-01-01

    The compact formula for the parameter for the magnetic ions superexchange interaction through intermediate anions with an account of the polaron effects both on the magnetic ions and intermediate anions is obtained. It is applied for the analysis of the basic peculiarities of these types of temperature in the layered cuprates on the HTSC basis: the Neel temperature (T sub N), critical temperatures of the transition into the superconducting state (T sub c) and characteristic temperatures of the normal phases pseudogap state (T*). The calculations are based on the scenario of competition of the superconducting phase with the charge-current waves phase. The agreement of the calculation with the experiment testifies to the benefit of the above scenario

  11. [Hopping and superexchange mechanisms of charge transport to DNA].

    Science.gov (United States)

    Lakhno, V D; Sultanov, V B

    2003-01-01

    A theory for charge transport in nucleobase sequences was constructed in which the hole migration proceeds via hopping between guanines. Each hop over the adenine-thymine (A-T) bridge connecting neighboring guanines occurs by means of the superexchange mechanism. The experimental data and theoretical results for various types of nucleobase sequences are compared.

  12. Superexchange-Driven Magnetoelectricity in Magnetic Vortices

    NARCIS (Netherlands)

    Delaney, Kris T.; Mostovoy, Maxim; Spaldin, Nicola A.

    2009-01-01

    We demonstrate that magnetic vortices in which spins are coupled to polar lattice distortions via superexchange exhibit an unusually large linear magnetoelectric response. We show that the periodic arrays of vortices formed by frustrated spins on kagome lattices provide a realization of this concept

  13. Magnetism in Ca2CoOsO6 and Ca2NiOsO6: Unraveling the mystery of superexchange interactions between 3d and 5d ions

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, Ryan C.; Samanta, Kartik; Dasgupta, Tanusri Saha; Xiong, Jie; Freeland, John W.; Haskel, Daniel; Woodward, Patrick

    2016-06-14

    In order to rationalize and predict the behavior of compounds containing 5d transition metal ions, an understanding of the local moments and superexchange interactions from which their magnetic properties are derived is necessary. The magnetic and electrical properties of the ferrimagnetic double perovskites Ca2CoOsO6 and Ca2NiOsO6 studied here provide critical insight toward that goal. First-principles density functional theory (DFT) calculations indicate, and experimental measurements confirm, that the Os(VI) moments are directed antiparallel to the Co/Ni moments. X-ray magnetic circular dichroism (XMCD) measurements reveal that the orbital moment on osmium has a magnitude that is approximately 30% of the spin moment, and the two contributions oppose each other. Both the size and direction of the orbital moment are confirmed by the DFT calculations. The size of the Os(VI) total moment is predicted to be 0.6-0.7 μB by DFT calculations. The ferrimagnetic ground state is stabilized by strong antiferromagnetic coupling between the d2 Os(VI) ion and the d8/d7 Ni(II)/Co(II) ion. Not only does the observation of antiferromagnetic coupling violate the Goodenough-Kanamori rules, but also it is unusual in that it becomes stronger as the Os-O-Co/Ni bond angle decreases. This unusual behavior is shown to arise predominantly from coupling between Os t2g orbitals and Ni/Co eg orbitals, mediated by the intervening oxide ion. We further find that both compounds are spin-orbit assisted Mott insulators.

  14. Double spin-glass-like behavior and antiferromagnetic superexchange interaction between Fe3+ ions in α-Ga2-xFexO3 (0 ≤ x ≤ 0.4)

    Science.gov (United States)

    Lv, Yi-Fei; Xiang, Jian-Yong; Wen, Fu-Sheng; Lv, Wei-Ming; Hu, Wen-Tao; Liu, Zhong-Yuan

    2015-03-01

    Single phase of Fe3+-doped α-Ga2-xFexO3 (α-GFxO, x = 0.1, 0.2, 0.3, 0.4) is synthesized by treating the β-Ga2-xFexO3 (β-GFxO) precursors at high temperatures and high pressures. Rietveld refinements of the X-ray diffraction data show that the lattice constants increase monotonically with the increase of Fe3+ content. Calorimetric measurements show that the temperature of the phase transition from α-GFxO to β-GFxO increases, while the associated enthalpy change decreases upon increasing Fe3+ content. The optical energy gap deduced from the reflectance measurement is found to decrease monotonically with the increase in Fe3+ content. From the measurements of magnetic field-dependent magnetization and temperature-dependent inverse molar susceptibility, we find that the superexchange interaction between Fe3+ ions is antiferromagnetic. Remnant magnetization is observed in the Fe3+-doped α-GFxO and is attributed to the spin glass in the magnetic sublattice. At high Fe3+ doping level (x = 0.4), two evident peaks are observed in the image part of the AC susceptibility . The frequency dependence in intensity of these two peaks as well as two spin freezing temperatures observed in the DC magnetization measurements of α-GF0.4O is suggested to be the behavior of two spin glasses. Project supported by the National Basic Research Program of China (Grant No. 2010CB731605), the National Science Fund for Distinguished Young Scholars of China (Grant No. 51025103), the National Natural Science Foundation of China (Grant Nos. 51172198 and 51102206), the Natural Science Foundation of Hebei Province, China (Grant No. E2014203144), the Science Foundation for the Excellent Youth Scholars from Universities and Colleges of Hebei Province, China (Grant No. YQ2014009), and the Research Program of the College Science & Technology of Hebei Province, China (Grant No. QN2014047).

  15. Interaction of Siglec-4 with naturally occurring and synthetic glycoconjugates

    OpenAIRE

    Koliwer-Brandl, Hendrik

    2011-01-01

    The aim of this work has been to provide insights into the structure-function relationship of Siglec-4 binding naturally occurring sialic acids as well as synthetic sialic acid derivatives. Structural information of the Siglec binding site and its interactions with glycoconjugates were obtained from homology modeling of the sialic acid binding domain and molecular docking calculations with several sialosides. Furthermore, the interaction of chemically synthesized sialic acid derivatives with ...

  16. Understanding the charge transport and polarities in organic donor-acceptor mixed-stack crystals: molecular insights from the super-exchange couplings.

    Science.gov (United States)

    Geng, Hua; Zheng, Xiaoyan; Shuai, Zhigang; Zhu, Lingyun; Yi, Yuanping

    2015-02-25

    Charge transport and polarity in organic D-A mixed-stack crystals are examined in terms of super-exchange electronic couplings. When the super-exchange coupling is dominated by the interaction between donor HOMO and acceptor LUMO, ambipolar transport is achieved. Otherwise, involvement of other bridge orbitals can lead to unbalanced, even to unipolar transport in a special case that the HOMO-LUMO interaction vanishes.

  17. Quantum treatment of the Anderson–Hasegawa model in the presence of superexchange

    Indian Academy of Sciences (India)

    P A Sreeram; Manidipa Mitra; Sushanta Dattagupta

    2003-09-01

    We revisit the Anderson–Hasegawa double-exchange model and critically examine its exact solution when the core spins are treated quantum mechanically. We show that the quantum effects, in the presence of an additional superexchange interaction between the core spins, yield a term, the significance of which has been hitherto ignored. The importance of this term is further assessed by numerically exact computation for a four-spin system.

  18. Charge Transport by Superexchange in Molecular Host-Guest Systems

    Science.gov (United States)

    Symalla, Franz; Friederich, Pascal; Massé, Andrea; Meded, Velimir; Coehoorn, Reinder; Bobbert, Peter; Wenzel, Wolfgang

    2016-12-01

    Charge transport in disordered organic semiconductors is generally described as a result of incoherent hopping between localized states. In this work, we focus on multicomponent emissive host-guest layers as used in organic light-emitting diodes (OLEDs), and show using multiscale ab initio based modeling that charge transport can be significantly enhanced by the coherent process of molecular superexchange. Superexchange increases the rate of emitter-to-emitter hopping, in particular if the emitter molecules act as relatively deep trap states, and allows for percolation path formation in charge transport at low guest concentrations.

  19. Interactions between plasma proteins and naturally occurring polyphenols.

    Science.gov (United States)

    Li, Min; Hagerman, Ann E

    2013-05-01

    The plant natural products known as polyphenols are found at micronutrient levels in fruits, vegetables, and plant-based beverages such as wine, tea, coffee and cocoa. Consumption of a fruit- and vegetable-rich diet, the "Mediterranean diet", has been epidemiologically related to health benefits especially for chronic diseases including diabetes, cardiovascular disease, and Alzheimer's disease. The abundance of polyphenols in plant-rich diets, and the potent bioactivities of polyphenols, provide indirect evidence for a role for polyphenols in maintaining good health. However, molecular mechanisms for therapeutic or preventative activity have not been demonstrated in vivo. We summarize the chemical classes of natural polyphenols, their bioactivities and bioavailability and metabolism. Because many polyphenols bind protein, we focus on the potential of protein binding to mediate the health-related effects of polyphenols. We discuss interactions with plasma proteins as the first target organ past the digestive tract for these orally-ingested compounds.

  20. Dinuclear Metallacycles with Single M-X-M Bridges (X = Cl(-), Br(-); M = Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II)): Strong Antiferromagnetic Superexchange Interactions.

    Science.gov (United States)

    Reger, Daniel L; Pascui, Andrea E; Foley, Elizabeth A; Smith, Mark D; Jezierska, Julia; Wojciechowska, Agnieszka; Stoian, Sebastian A; Ozarowski, Andrew

    2017-03-06

    A series of monochloride-bridged, dinuclear metallacycles of the general formula [M2(μ-Cl)(μ-L)2](ClO4)3 have been prepared using the third-generation, ditopic bis(pyrazolyl)methane ligands L = m-bis[bis(1-pyrazolyl)methyl]benzene (Lm), M = Cu(II), Zn(II), and L = m-bis[bis(3,5-dimethyl-1-pyrazolyl)methyl]benzene (Lm*), M = Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II). These complexes were synthesized from the direct reactions of M(ClO4)2·6H2O, MCl2, and the ligand, Lm or Lm*, in the appropriate stoichiometric amounts. Three analogous complexes of the formula [M2(μ-Cl)(μ-L)2](BF4)3, L = Lm, M = Cu(II), and L = Lm*, M = Co(II), Cu(II), were prepared from the reaction of [M2(μ-F)(μ-L)2](BF4)3 and (CH3)3SiCl. The bromide-bridged complex [Cu2(μ-Br)(μ-Lm*)2](ClO4)3 was prepared by the first method. Three acyclic complexes, [Co2(μ-Lm)μ-Cl4], [Co2(μ-Lm*)Cl4], and [Co2(μ-Lm*)Br4], were also prepared. The structures of all [M2(μ-X)(μ-L)2](3+) (X = Cl(-), Br(-)) complexes have two ditopic bis(pyrazolyl)methane ligands bridging two metals in a metallacyclic arrangement. The fifth coordination site of the distorted trigonal bipyramidal metal centers is filled by a bridging halide ligand that has an unusual linear or nearly linear M-X-M angle. The NMR spectra of [Zn2(μ-Cl)(μ-Lm*)2](ClO4)3 and especially [Cd2(μ-Cl)(μ-Lm*)2](ClO4)3 demonstrate that the metallacycle structure is maintained in solution. Solid state magnetic susceptibility data for the copper(II) compounds show very strong antiferromagnetic exchange interactions, with -J values of 536 cm(-1) for [Cu2(μ-Cl)(μ-Lm)2](ClO4)3·xCH3CN, 720 cm(-1) for [Cu2(μ-Cl)(μ-Lm*)2](ClO4)3, and 945 cm(-1) for [Cu2(μ-Br)(μ-Lm*)2](ClO4)3·2CH3CN. Smaller but still substantial antiferromagnetic interactions are observed with other first row transition metals, with -J values of 98 cm(-1) for [Ni2(μ-Cl)(μ-Lm*)2](ClO4)3, 55 cm(-1) for [Co2(μ-Cl)(μ-Lm*)2](ClO4)3, and 34 cm(-1) for [Fe2(μ-Cl)(μ-Lm*)2](ClO4

  1. Competition between strain and superexchange mediated magnetism in modified cobalt ferrite

    Science.gov (United States)

    Kumar, Rajnish; Aman, Abhay Kr.; Singh, Rakesh Kr.; Kar, Manoranjan

    2017-05-01

    Co1-xSrxFe2-xTixO4 (x = 0.01, 0.05, 0.1, 0.15, 0.2) has been synthesized using the sol-gel technique. The phase purity of the material has been studied by employing the X-ray powder diffraction (XRD) technique. The obtained XRD pattern shows the characteristic of F d 3 ¯m space group in cubic symmetry. The magnetic hysteresis loop has been recorded using vibrating sample magnetometer (VSM) at room temperature in the field range of ±2T. The loop has been studied using Law of Approach (LA) to saturation to calculate magnetocrystalline anisotropy. The magnetocrystalline anisotropy and saturation magnetization decrease with increase in doping concentration. Competition between strain mediated magnetism and magnetism due to superexchange interactions between cations has been observed.

  2. Verification of Anderson Superexchange in MnO via Magnetic Pair Distribution Function Analysis and ab initio Theory

    Science.gov (United States)

    Frandsen, Benjamin A.; Brunelli, Michela; Page, Katharine; Uemura, Yasutomo J.; Staunton, Julie B.; Billinge, Simon J. L.

    2016-05-01

    We present a temperature-dependent atomic and magnetic pair distribution function (PDF) analysis of neutron total scattering measurements of antiferromagnetic MnO, an archetypal strongly correlated transition-metal oxide. The known antiferromagnetic ground-state structure fits the low-temperature data closely with refined parameters that agree with conventional techniques, confirming the reliability of the newly developed magnetic PDF method. The measurements performed in the paramagnetic phase reveal significant short-range magnetic correlations on a ˜1 nm length scale that differ substantially from the low-temperature long-range spin arrangement. Ab initio calculations using a self-interaction-corrected local spin density approximation of density functional theory predict magnetic interactions dominated by Anderson superexchange and reproduce the measured short-range magnetic correlations to a high degree of accuracy. Further calculations simulating an additional contribution from a direct exchange interaction show much worse agreement with the data. The Anderson superexchange model for MnO is thus verified by experimentation and confirmed by ab initio theory.

  3. Interaction of flavonoids, the naturally occurring antioxidants with different media: A UV-visible spectroscopic study

    Science.gov (United States)

    Naseem, Bushra; Shah, S. W. H.; Hasan, Aurangzeb; Sakhawat Shah, S.

    2010-04-01

    Quantitative parameters for interaction of flavonoids—the naturally occurring antioxidants, with solvents and surfactants are determined using UV-visible absorption spectroscopy. The availability of flavonoids; kaempferol, apigenin, kaempferide and rhamnetin in micelles of sodium dodecyl sulfate (SDS) is reflected in terms of partition coefficient, Kc. Thermodynamic calculations show that the process of transfer of flavonoid molecules to anionic micelles of SDS is energy efficient. A distortion in flavonoid's morphology occurs in case of kaempferol and apigenin in surfactant and water, exhibited in terms of a new band in the UV region of electronic spectra of these flavonoids. The partition coefficients of structurally related flavonoids are correlated with their antioxidant activities.

  4. Investigation on intermolecular interaction between two solutes where one solute occurs in two states

    Science.gov (United States)

    Kang, Xiaoyan; He, Anqi; Guo, Ran; Chen, Jing; Zhai, Yanjun; Xu, Yizhuang; Noda, Isao; Wu, Jinguang

    2016-11-01

    The spectral behavior of a pair of 2D asynchronous spectra generated by using the double asynchronous orthogonal sample design (DAOSD) approach on a chemical system is investigated. Two solutes (P and Q) are dissolved in the solution and intermolecular interaction between P and Q is characterized. In this particular system, P occurs in two exchangeable states when it is dissolved in the solutions. Results on mathematical analysis and computer simulation demonstrated that interference unrelated to the intermolecular interaction can be completely removed. Hence the resultant 2D asynchronous spectra generated by using the DAOSD approach can reflect intermolecular interaction reliably. Moreover, properties of cross peaks in different regions of the pair of asynchronous spectra are discussed. In our previous works, cross peaks generated by using the DAOSD and relevant techniques reflect variations on peak position, bandwidth or absorptivity of the characteristic peaks of solutes caused by intermolecular interaction. However, we find that cross peak can still be produced even if intermolecular interaction do not bring about any changes on the characteristic peaks of solutes. Mathematical analysis demonstrates that cross peaks are related to the variations of chemical systems caused by intermolecular interaction at a network level.

  5. Interaction of flavonoids, the naturally occurring antioxidants with different media: a UV-visible spectroscopic study.

    Science.gov (United States)

    Naseem, Bushra; Shah, S W H; Hasan, Aurangzeb; Sakhawat Shah, S

    2010-04-01

    Quantitative parameters for interaction of flavonoids-the naturally occurring antioxidants, with solvents and surfactants are determined using UV-visible absorption spectroscopy. The availability of flavonoids; kaempferol, apigenin, kaempferide and rhamnetin in micelles of sodium dodecyl sulfate (SDS) is reflected in terms of partition coefficient, K(c). Thermodynamic calculations show that the process of transfer of flavonoid molecules to anionic micelles of SDS is energy efficient. A distortion in flavonoid's morphology occurs in case of kaempferol and apigenin in surfactant and water, exhibited in terms of a new band in the UV region of electronic spectra of these flavonoids. The partition coefficients of structurally related flavonoids are correlated with their antioxidant activities. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Probing the magnetic superexchange couplings between terminal CuII ions in heterotrinuclear bis(oxamidato type complexes

    Directory of Open Access Journals (Sweden)

    Mohammad A. Abdulmalic

    2017-04-01

    Full Text Available The reaction of one equivalent of [n-Bu4N]2[Ni(opboR2] with two equivalents of [Cu(pmdta(X2] afforded the heterotrinuclear CuIINiIICuII containing bis(oxamidato type complexes [Cu2Ni(opboR2(pmdta2]X2 (R = Me, X = NO3– (1; R = Et, X = ClO4– (2; R = n-Pr, X = NO3– (3; opboR2 = o-phenylenebis(NR-substituted oxamidato; pmdta = N,N,N’,N”,N”-pentamethyldiethylenetriamine. The identities of the heterotrinuclear complexes 1–3 were established by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction studies, which revealed the cationic complex fragments [Cu2Ni(opboR2(pmdta2]2+ as not involved in any further intermolecular interactions. As a consequence thereof, the complexes 1–3 possess terminal paramagnetic [Cu(pmdta]2+ fragments separated by [NiII(opboR2]2– bridging units representing diamagnetic SNi = 0 states. The magnetic field dependence of the magnetization M(H of 1–3 at T = 1.8 K has been determined and is shown to be highly reproducible with the Brillouin function for an ideal paramagnetic spin = 1/2 system, verifying experimentally that no magnetic superexchange couplings exists between the terminal paramagnetic [Cu(pmdta]2+ fragments. Susceptibility measurements versus temperature of 1–3 between 1.8–300 K were performed to reinforce the statement of the absence of magnetic superexchange couplings in these three heterotrinuclear complexes.

  7. Reentrant phenomenon and inverse magnetocaloric effect in a generalized spin-(1/2,  s) Fisher’s super-exchange antiferromagnet

    Science.gov (United States)

    Gálisová, Lucia

    2016-11-01

    The thermodynamic and magnetocaloric properties of a generalized spin-(1/2,  s) Fisher’s super-exchange antiferromagnet are investigated precisely by using the decoration-iteration mapping transformation. Besides the critical temperature, sublattice magnetization, total magnetization, entropy and specific heat, the isothermal entropy change and adiabatic temperature change are also rigorously calculated in order to examine the cooling efficiency of the model in the vicinity of the first- and second-order phase transitions. It is shown that an enhanced inverse magnetocaloric effect occurs around the temperature interval {{T}\\text{c}}(B\

  8. Photoinduced electron transfer across molecular bridges: electron- and hole-transfer superexchange pathways.

    Science.gov (United States)

    Natali, Mirco; Campagna, Sebastiano; Scandola, Franco

    2014-06-21

    Photoinduced electron transfer plays key roles in many areas of chemistry. Superexchange is an effective model to rationalize photoinduced electron transfer, particularly when molecular bridges between donor and acceptor subunits are present. In this tutorial review we discuss, within a superexchange framework, the complex role played by the bridge, with an emphasis on differences between thermal and photoinduced electron transfer, oxidative and reductive photoinduced processes, charge separation and charge recombination. Modular bridges are also considered, with specific attention to the distance dependence of donor-acceptor electronic coupling and electron transfer rate constants. The possibility of transition, depending on the bridge energetics, from coherent donor-acceptor electron transfer to incoherent charge injection and hopping through the bridge is also discussed. Finally, conceptual analogies between bridge effects in photoinduced electron transfer and optical intervalence transfer are outlined. Selected experimental examples, instrumental to illustration of the principles, are discussed.

  9. Characteristics of Academic Language Register Occurring in Caretaker-Child Interaction: Development and Validation of a Coding Scheme

    Science.gov (United States)

    Aarts, Rian; Demir, Serpil; Vallen, Ton

    2011-01-01

    This article aims at validating a coding scheme designed to investigate the precursors of academic language occurring in early caretaker-child interactions. Exposure to the academic dimensions of language is an important asset for children to be successful in academic settings. The proposed analytical framework, based on systemic functional…

  10. B cell: T cell interactions occur within hepatic granulomas during experimental visceral leishmaniasis.

    Directory of Open Access Journals (Sweden)

    John W J Moore

    Full Text Available Hepatic resistance to Leishmania donovani infection in mice is associated with the development of granulomas, in which a variety of lymphoid and non-lymphoid populations accumulate. Although previous studies have identified B cells in hepatic granulomas and functional studies in B cell-deficient mice have suggested a role for B cells in the control of experimental visceral leishmaniasis, little is known about the behaviour of B cells in the granuloma microenvironment. Here, we first compared the hepatic B cell population in infected mice, where ≈60% of B cells are located within granulomas, with that of naïve mice. In infected mice, there was a small increase in mIgM(lomIgD(+ mature B2 cells, but no enrichment of B cells with regulatory phenotype or function compared to the naïve hepatic B cell population, as assessed by CD1d and CD5 expression and by IL-10 production. Using 2-photon microscopy to quantify the entire intra-granuloma B cell population, in conjunction with the adoptive transfer of polyclonal and HEL-specific BCR-transgenic B cells isolated from L. donovani-infected mice, we demonstrated that B cells accumulate in granulomas over time in an antigen-independent manner. Intra-vital dynamic imaging was used to demonstrate that within the polyclonal B cell population obtained from L. donovani-infected mice, the frequency of B cells that made multiple long contacts with endogenous T cells was greater than that observed using HEL-specific B cells obtained from the same inflammatory environment. These data indicate, therefore, that a subset of this polyclonal B cell population is capable of making cognate interactions with T cells within this unique environment, and provide the first insights into the dynamics of B cells within an inflammatory site.

  11. Superexchange coupling and electron transfer in globular proteins via polaron excitations.

    Science.gov (United States)

    Chuev, G N; Lakhno, V D; Ustitnin, M N

    2000-06-01

    The polaron approach is used to treat long-range electron transfersbetween globular proteins. A rate expression for the polaron transfer model is given along with a description of appropriate conditions forits use. Assuming that electrons transfer via a superexchange couplingdue to a polaron excitation, we have estimated the distance dependenceof the rate constant for the self-exchange reactions between globularproteins in solutions. The distance dependence of the polaron coupling andsolvent reorganization energy are provided as a basis forunderstanding and interpreting a long-range electron transfer experiment.The difficulties and problems of the polaron treatment of long-rangeelectron transfers are discussed, and suggestions for new experimentsare made.

  12. Multi-function oxidases are responsible for the synergistic interactions occurring between repellents and insecticides in mosquitoes

    Directory of Open Access Journals (Sweden)

    Duchon Stéphane

    2009-04-01

    Full Text Available Abstract Background With the spread of pyrethroid resistance in mosquitoes, the combination of an insecticide (carbamate or organophosphate with a repellent (DEET is considered as a promising alternative strategy for the treatment of mosquito nets and other relevant materials. The efficacy of these mixtures comes from the fact that they reproduce pyrethroid features and that positive interactions occur between insecticides and repellent. To better understand the mechanisms involved and assess the impact of detoxifying enzymes (oxidases and esterases in these interactions, bioassays were carried out in the laboratory against the main dengue vector Aedes aegypti. Methods Topical applications of DEET and propoxur (carbamate, used alone or as a mixture, were carried out on female mosquitoes, using inhibitors of the two main detoxification pathways in the insect. PBO, an inhibitor of multi-function oxidases, and DEF, an inhibitor of esterases, were applied one hour prior to the main treatment. Results Results showed that synergism between DEET and propoxur disappeared in the presence of PBO but not with DEF. This suggests that oxidases, contrary to esterases, play a key role in the interactions occurring between DEET and cholinesterase inhibitors in mosquitoes. Conclusion These findings are of great interest for the implementation of "combination nets" in the field. They support the need to combine insecticide with repellent to overcome insecticide resistance in mosquitoes of public health importance.

  13. Seed trait-mediated selection by rodents affects mutualistic interactions and seedling recruitment of co-occurring tree species.

    Science.gov (United States)

    Zhang, Hongmao; Yan, Chuan; Chang, Gang; Zhang, Zhibin

    2016-02-01

    As mutualists, seed dispersers may significantly affect mutualistic interactions and seedling recruitment of sympatric plants that share similar seed dispersers, but studies are rare. Here, we compared seed dispersal fitness in two co-occurring plant species (Armeniaca sibirica and Amygdalus davidiana) that inhabit warm temperate deciduous forest in northern China. We tested the hypothesis that seed trait-mediated selection by rodents may influence mutualistic interactions with rodents and then seedling establishment of co-occurring plant species. A. davidiana seeds are larger and harder (thick endocarps) than A. sibirica seeds, but they have similar levels of nutrients (crude fat, crude protein), caloric value and tannin. More A. sibirica seedlings are found in the field. Semi-natural enclosure tests indicated that the two seed species were both harvested by the same six rodent species, but that A. sibirica had mutualistic interactions (scatter hoarding) with four rodent species (Apodemus peninsulae, A. agrarius, Sciurotamias davidianus, Tamias sibiricus), and A. davidiana with only one (S. davidianus). Tagged seed dispersal experiments in the field indicated that more A. sibirica seeds were scatter-hoarded by rodents, and more A. sibirica seeds survived to the next spring and became seedlings. A. sibirica seeds derive more benefit from seed dispersal by rodents than A. davidiana seeds, particularly in years with limited seed dispersers, which well explained the higher seedling recruitment of A. sibirica compared with that of A. davidiana under natural conditions. Our results suggest that seed dispersers may play a significant role in seedling recruitment and indirect competition between co-occurring plant species.

  14. Theory of ferromagnetism driven by superexchange in dilute magnetic semi-conductors

    Directory of Open Access Journals (Sweden)

    Simserides C.

    2014-07-01

    Full Text Available Magnetic properties of Ga1−xMnxN are studied theoretically by employing a tight binding approach to determine exchange integrals Jij characterizing the coupling between Mn spin pairs located at distances Rij up to the 16th cation coordination sphere in zinc-blende GaN. It is shown that for a set of experimentally determined input parameters there are no itinerant carriers and the coupling between localized Mn3+ spins in GaN proceeds via superexchange that is ferromagnetic for all explored Rij values. Extensive Monte Carlo simulations serve to evaluate the magnitudes of Curie temperature TC by the cumulant crossing method. The theoretical values of TC(x are in quantitative agreement with the experimental data that are available for Ga1−xMnxN with randomly distributed Mn3+ ions with the concentrations 0.01 ≤ x ≤ 0.1.

  15. Superconductivity in optimally doped cuprates: BZA program works well and superexchange is the glue

    Directory of Open Access Journals (Sweden)

    G. Baskaran

    2006-09-01

    Full Text Available   Resonating valence bond states in a doped Mott insulator was proposed to explain superconductivity in cuprates in January 1987 by Anderson. A challenging task then was proving existence of this unconventional mechanism and a wealth of possibilities, with a rigor acceptable in standard condensed matter physics, in a microscopic theory and develop suitable many body techniques. Shortly, a paper by Anderson, Zou and us (BZA undertook this task and initiated a program. Three key papers that followed, shortly, essentially completed the program, as far as superconductivity is concerned,i a gauge theory approach by Anderson and us, that went beyond mean field theory ii Kotliar’s d -wave solution in BZA theory iii improvement of a renormalized Hamiltonian in BZA theory, using a Gutzwiller approximation by Zhang, Gros, Rice and Shiba. In this article I shall focus on the merits of BZA and gauge theory papers. They turned out to be a foundation for subsequent developments dealing with more aspects that were unconventional - d -wave order parameter with nodal Bogoliubov quasi particles, Affleck-Marston’s π-flux condensed spin liquid phase, unconventional spin-1 collective mode at (π, π, and other fascinating developments. Kivelson, Rokhsar and Sethna’s idea of holons and their bose condensation found expression in the slave boson formalism and lead to results similar to BZA program. At optimal doping, correlated electrons acquire sufficient fermi sea character, at the same time retain enough superexchange inherited from a Mott insulator parentage, ending in a BCS like situation with superexchange as a glue! Not surprisingly, mean field theory works well at optimal doping, even quantitatively. Further, t-J model is a minimal model only around optimal doping, where RVB superconductivity is also at its best.

  16. Soil fertility and disturbance interact to drive contrasting responses of co-occurring native and nonnative species.

    Science.gov (United States)

    Peltzer, Duane A; Kurokawa, Hiroko; Wardle, David A

    2016-02-01

    Some plant functional groups such as nonnative invasive and nitrogen (N)-fixing plants are widely thought to have consistent, coordinated differences in their functional traits relative to other groups such as native and non -N-fixing plants. Recent evidence suggests that these trait differences between groups can be context dependent, varying with environmental factors such as resource availability and disturbance. However, many previous comparisons among plant groups differing in invasion status have not standardized growth form between groups or have compared species that do not co-occur, which could result in invasion status per se being confounded with other factors. We determined growth and leaf functional trait responses of 20 co-occurring woody species, that is, five species within each of four functional groups (native N-fixers, native non -N-fixers, nonnative [invasive] N-fixers and nonnative [invasive] non-N-fixers), to factorial combinations of soil fertility and defoliation treatments in a mesocosm experiment to test each of two hypotheses. First, we hypothesized that nonnative invasive and N-fixing species will have functional traits associated with rapid resource acquisition whereas natives and non -N-fixing species will have traits linked to resource conservation. Second, we hypothesized that plant growth and leaf traits of nonnative and N-fixing species will be more strongly influenced by environmental factors (i.e., soil fertility and disturbance) than will natives and non-N-fixers. Plant growth, foliar nutrients, and leaf structural traits varied among plant functional groups in a manner consistent with our first hypothesis. Support for our second hypothesis was mixed; origin (native vs. nonnative) and soil fertility rarely interacted to determine plant growth or variation in leaf traits whereas interactions involving N-fixing ability and soil fertility were common. Further, there were no consistent interactive effects between plant groupings and

  17. Superexchange interaction enhancement of the quantum transport in a DNA-type molecule

    Institute of Scientific and Technical Information of China (English)

    Wang Rui; Zhang Cun-Xi; Zhou Yun-Qing; Kong Ling-Min

    2011-01-01

    We use the transfer matrix method and the Green function technique to theoretically study the quantum tunnelling through a DNA-type molecule.Ferromagnetic electrodes are used to produce the spin-polarized transmission probability and therefore the spin current.The distance-dependent crossover comes from the topological variation from the onedimensional to the two-dimensional model transform as we switch on the interstrand coupling; a new base pair will present N - 1 extrachannels for the charge and spin as N being the total base pairs.This will restrain the decay of the transmission and improve the stability of the quantum transport.The spin and charge transfer through the DNA-type molecule is consistent with the quantum tunneling barrier.

  18. Doubly TEMPO-coordinated gadolinium(III), lanthanum(III), and yttrium(III) complexes. Strong superexchange coupling across rare earth ions.

    Science.gov (United States)

    Murakami, Rina; Nakamura, Takeshi; Ishida, Takayuki

    2014-04-21

    We prepared crystalline [RE(III)(hfac)3(TEMPO)2] (RE = Gd, La, Y), where TEMPO and hfac stand for 2,2,6,6-tetramethylpiperidin-1-oxyl and 1,1,1,5,5,5-hexafluoropentane-2,4-dionate, respectively. The X-ray crystal structure of TEMPO-coordinated RE compounds was determined for the first time. The Gd and Y analogues are isomorphous, and the La derivative has a similar molecular skeleton. The Gd-O(TEMPO) bond lengths were 2.322(3) and 2.354(3) Å with the O-Gd-O angle of 140.36(11)°. The magnetic study clarified that [Gd(hfac)3(TEMPO)2] behaved as a ground Stotal = 7/2 species. The La and Y analogues showed the superexchange interactions across the diamagnetic ions with 2JTEMPO1-TEMPO2/kB = -14.9(1) and -49.8(2) K, respectively. Assuming the presence of a similar interaction like the Y derivative, the Gd-TEMPO exchange couplings are estimated with 2JGd-TEMPO/kB = -12.9(5) and +8.0(6) K.

  19. Intramolecular Charge Transfer of Carotene-porphyrin-fullerene Triad: Sequential or Superexchange Cechanism

    Institute of Scientific and Technical Information of China (English)

    SUN,Yu; CHEN,Yue-Hui; LI,Yuan-Zuo; LI,Yong-Qing; MA,Feng-Cai

    2008-01-01

    As an excellent artificial photosynthetic reaction center,the carotene (C)-porphyrin (P)-fullerene (F) triad was extensively investigated experimentally.To reveal the mechanism of the intramolecular charge transfer (ICT) on the mimic of photosynthetic solar energy conversion (such as singlet energy transfer between pigments,and photoinduced electron transfer from excited singlet states to give long-lived charge-separated states),the ICT mechanisms of C-P-F triad on the exciton were theoretically studied with quantum chemical methods as well as the 2D and 3D real space analysis approaches.The results of quantum chemical methods reveal that the excited states are the ICT states,since the densities of HOMO are localized in the carotene or porphyrin unit,and the densities of LUMO are localized in the fullerene unit.Furthermore,the excited states should be the intramolecular superexchange charge transfer (ISCT) states for the orbital transition from the HOMO whose densities are localized in the carotene to the LUMO whose densities are localized in the fullerene unit.The 3D charge difference densities can clearly show that some excited states are ISCT excited states,since the electron and hole are resident in the fullerene and carotene units,respectively.From the results of the electron-hole coherence of the 2D transition density matrix,not only 3D results are supported,but also the delocalization size on the exciton can be observed.These phenomena were further interpreted with non-linear optical effect.The large changes of the linear and non-linear polarizabilities on the exciton result in the charge separate states,and if their changes are large enough,the ICT mechanism can become the ISCT on the exciton.

  20. Reentrant phenomenon and inverse magnetocaloric effect in a generalized spin-(1/2,  s) Fisher's super-exchange antiferromagnet.

    Science.gov (United States)

    Gálisová, Lucia

    2016-11-30

    The thermodynamic and magnetocaloric properties of a generalized spin-(1/2,  s) Fisher's super-exchange antiferromagnet are investigated precisely by using the decoration-iteration mapping transformation. Besides the critical temperature, sublattice magnetization, total magnetization, entropy and specific heat, the isothermal entropy change and adiabatic temperature change are also rigorously calculated in order to examine the cooling efficiency of the model in the vicinity of the first- and second-order phase transitions. It is shown that an enhanced inverse magnetocaloric effect occurs around the temperature interval [Formula: see text] for any magnetic-field change [Formula: see text]. The most pronounced inverse magnetocaloric effect can be found nearby the critical field, which corresponds to the zero-temperature phase transition from the long-range ordered ground state to the paramagnetic one. The observed phenomenon increases with an increasing value of decorating spins. Furthermore, sufficiently high values of decorating spins have also been linked to the possibility of observing reentrant phase transitions at finite temperatures.

  1. High temperature susceptibility in electron doped Ca sub 1 sub - sub x Y sub x MnO sub 3 double exchange versus superexchange

    CERN Document Server

    Aliaga, H; Tovar, M; Butera, A; Alascio, B; Vega, D; Leyva, G; Polla, G; König, P

    2003-01-01

    We present a study of the magnetic properties of the electron doped manganites Ca sub 1 sub - sub x Y sub x MnO sub 3 (for 0 sup 450 K and, below this temperature, chi sup - sup 1 (T) shows a ferrimagnetic-like curvature. We approached the discussion of these results in terms of a simple mean-field model where double exchange, approximated by a ferromagnetic Heisenberg-like interaction between Mn sup 3 sup + and Mn sup 4 sup + ions, competes with classical superexchange. For higher levels of doping (x sup>= 0.15), the CW behaviour is observed down to the magnetic ordering temperature (T sub m sub o) and a better description of chi(T) was obtained by assuming full delocalization of the e sub g electrons. In order to explore the degree of delocalization as a function of T and x, we analysed the problem through Monte Carlo simulations. Within this picture we found that at high T the electrons doped are completely delocalized but, when T sub m sub o is approached, they form magnetic polarons of large spin that ca...

  2. Trophic interaction between topmouth gudgeon (Pseudorasbora parva) and the co-occurring species during summer in the Dniprodzerzhynsk reservoir

    OpenAIRE

    Didenko A.V.; Kruzhylina S.V.

    2015-01-01

    Topmouth gudgeon, Pseudorasbora parva is the most common invasive fish in Europe, which can compete with the juveniles of valuable commercial fishes. The goal of this work is to study the diet of topmouth gudgeon and trophic relationships with some native fishes inhabiting the littoral zone of the Dniprodzerzhynsk reservoir. The obtained relatively low values of diet overlaps between topmouth gudgeon and other co-occurring cypri...

  3. Antiferromagnetic superexchange via 3d states of titanium in EuTiO3 as seen from hybrid Hartree-Fock density functional calculations

    Science.gov (United States)

    Akamatsu, Hirofumi; Kumagai, Yu; Oba, Fumiyasu; Fujita, Koji; Murakami, Hideo; Tanaka, Katsuhisa; Tanaka, Isao

    2011-06-01

    A superexchange mechanism between Eu2+ 4f spins via the 3d states of nonmagnetic Ti4+ ions is proposed through first-principles calculations based on a hybrid Hartree-Fock density functional approach to explain G-type antiferromagnetism in EuTiO3. This mechanism is supported by systematic calculations for related Eu2+-based perovskite oxides. In EuTiO3, the competition between the antiferromagnetic superexchange and an indirect ferromagnetic exchange via the Eu 5d states leads to a delicate balance between antiferromagnetic and ferromagnetic phases. The superexchange mechanism involving the Ti 3d states hints at the microscopic origin of the strong spin-lattice coupling in EuTiO3.

  4. Trophic interaction between topmouth gudgeon (Pseudorasbora parva and the co-occurring species during summer in the Dniprodzerzhynsk reservoir

    Directory of Open Access Journals (Sweden)

    Didenko A.V.

    2015-01-01

    Full Text Available Topmouth gudgeon, Pseudorasbora parva is the most common invasive fish in Europe, which can compete with the juveniles of valuable commercial fishes. The goal of this work is to study the diet of topmouth gudgeon and trophic relationships with some native fishes inhabiting the littoral zone of the Dniprodzerzhynsk reservoir. The obtained relatively low values of diet overlaps between topmouth gudgeon and other co-occurring cyprinids such as juvenile roach, Rutilus rutilus; silver bream, Blicca bjoerkna; rudd, Scardinius erythrophthalmus; Prussian carp, Carassius gibelio and bleak, Abramis brama, indicate that it is not a serious food competitor for them, especially commercially valuable ones. On the contrary, high diet overlaps were observed among some native cyprinids such as juvenile roach, silver bream, rudd, and bleak. The major prey items of topmouth gudgeon were Chydorus sphaericus and chironomids, whereas other cyprinids selected Bosmina spp. This peculiarity may be due to different vertical distributions of these fish in the littoral zone of the reservoir, where topmouth gudgeon inhabit near-bottom water layers, where they preyed on near-bottom and benthic zooplankters and chironomids, while juvenile roach, silver bream, rudd, and juvenile and adult bleak live in higher water layers, where they preyed on pelagic zooplankton.

  5. Staphylococcal phenotypes induced by naturally occurring and synthetic membrane-interactive polyphenolic β-lactam resistance modifiers.

    Directory of Open Access Journals (Sweden)

    Lucia Palacios

    Full Text Available Galloyl catechins, in particular (--epicatechin gallate (ECg, have the capacity to abrogate β-lactam resistance in methicillin-resistant strains of Staphylococcus aureus (MRSA; they also prevent biofilm formation, reduce the secretion of a large proportion of the exoproteome and induce profound changes to cell morphology. Current evidence suggests that these reversible phenotypic traits result from their intercalation into the bacterial cytoplasmic membrane. We have endeavoured to potentiate the capacity of ECg to modify the MRSA phenotype by stepwise removal of hydroxyl groups from the B-ring pharmacophore and the A:C fused ring system of the naturally occurring molecule. ECg binds rapidly to the membrane, inducing up-regulation of genes responsible for protection against cell wall stress and maintenance of membrane integrity and function. Studies with artificial membranes modelled on the lipid composition of the staphylococcal bilayer indicated that ECg adopts a position deep within the lipid palisade, eliciting major alterations in the thermotropic behaviour of the bilayer. The non-galloylated homolog (--epicatechin enhanced ECg-mediated effects by facilitating entry of ECg molecules into the membrane. ECg analogs with unnatural B-ring hydroxylation patterns induced higher levels of gene expression and more profound changes to MRSA membrane fluidity than ECg but adopted a more superficial location within the bilayer. ECg possessed a high affinity for the positively charged staphylococcal membrane and induced changes to the biophysical properties of the bilayer that are likely to account for its capacity to disperse the cell wall biosynthetic machinery responsible for β-lactam resistance. The ability to enhance these properties by chemical modification of ECg raises the possibility that more potent analogs could be developed for clinical evaluation.

  6. PIPE: a protein-protein interaction prediction engine based on the re-occurring short polypeptide sequences between known interacting protein pairs

    Directory of Open Access Journals (Sweden)

    Greenblatt Jack

    2006-07-01

    Full Text Available Abstract Background Identification of protein interaction networks has received considerable attention in the post-genomic era. The currently available biochemical approaches used to detect protein-protein interactions are all time and labour intensive. Consequently there is a growing need for the development of computational tools that are capable of effectively identifying such interactions. Results Here we explain the development and implementation of a novel Protein-Protein Interaction Prediction Engine termed PIPE. This tool is capable of predicting protein-protein interactions for any target pair of the yeast Saccharomyces cerevisiae proteins from their primary structure and without the need for any additional information or predictions about the proteins. PIPE showed a sensitivity of 61% for detecting any yeast protein interaction with 89% specificity and an overall accuracy of 75%. This rate of success is comparable to those associated with the most commonly used biochemical techniques. Using PIPE, we identified a novel interaction between YGL227W (vid30 and YMR135C (gid8 yeast proteins. This lead us to the identification of a novel yeast complex that here we term vid30 complex (vid30c. The observed interaction was confirmed by tandem affinity purification (TAP tag, verifying the ability of PIPE to predict novel protein-protein interactions. We then used PIPE analysis to investigate the internal architecture of vid30c. It appeared from PIPE analysis that vid30c may consist of a core and a secondary component. Generation of yeast gene deletion strains combined with TAP tagging analysis indicated that the deletion of a member of the core component interfered with the formation of vid30c, however, deletion of a member of the secondary component had little effect (if any on the formation of vid30c. Also, PIPE can be used to analyse yeast proteins for which TAP tagging fails, thereby allowing us to predict protein interactions that are not

  7. The Dynamics of Genetic Interactions between Vibrio metoecus and Vibrio cholerae, Two Close Relatives Co-Occurring in the Environment.

    Science.gov (United States)

    Orata, Fabini D; Kirchberger, Paul C; Méheust, Raphaël; Barlow, E Jed; Tarr, Cheryl L; Boucher, Yan

    2015-10-09

    Vibrio metoecus is the closest relative of Vibrio cholerae, the causative agent of the potent diarrheal disease cholera. Although the pathogenic potential of this new species is yet to be studied in depth, it has been co-isolated with V. cholerae in coastal waters and found in clinical specimens in the United States. We used these two organisms to investigate the genetic interaction between closely related species in their natural environment. The genomes of 20 V. cholerae and 4 V. metoecus strains isolated from a brackish coastal pond on the US east coast, as well as 4 clinical V. metoecus strains were sequenced and compared with reference strains. Whole genome comparison shows 86-87% average nucleotide identity (ANI) in their core genes between the two species. On the other hand, the chromosomal integron, which occupies approximately 3% of their genomes, shows higher conservation in ANI between species than any other region of their genomes. The ANI of 93-94% observed in this region is not significantly greater within than between species, meaning that it does not follow species boundaries. Vibrio metoecus does not encode toxigenic V. cholerae major virulence factors, the cholera toxin and toxin-coregulated pilus. However, some of the pathogenicity islands found in pandemic V. cholerae were either present in the common ancestor it shares with V. metoecus, or acquired by clinical and environmental V. metoecus in partial fragments. The virulence factors of V. cholerae are therefore both more ancient and more widespread than previously believed. There is high interspecies recombination in the core genome, which has been detected in 24% of the single-copy core genes, including genes involved in pathogenicity. Vibrio metoecus was six times more often the recipient of DNA from V. cholerae as it was the donor, indicating a strong bias in the direction of gene transfer in the environment. © The Author(s) 2015. Published by Oxford University Press on behalf of the

  8. Capturing Earth Science Learning Dynamics: Communication Interactions of ESE Teachers and Children Occurring in Online, Classroom, and Small-Group Environments.

    Science.gov (United States)

    Snyder, C. W.; Prince, B. L.

    2002-12-01

    While the processes of schooling in science are usually measured in the resulting skills and products that students acquire or generate, another way to understand science learning is to explore the interactions and discourse that occur during actual learning activities. To investigate the dynamics of inquiry-based learning of earth science, we have explored the patterns that emerge in several learning environments: when teachers create dialog with other teachers in online ESE courses; when they teach earth science lessons in their classrooms; when they discuss their teaching perspectives in interviews; and when small groups of children engage in learning earth science together. By observing and scoring lesson exchanges, preserving online discussions, and documenting words and interactions in audio or video recordings, we are able to distinguish communication configurations that occur when teachers and children engage in the learning of earth science that would otherwise be invisible.

  9. The effect of uniaxial crystal-field anisotropy on magnetic properties of the superexchange antiferromagnetic Ising model

    Directory of Open Access Journals (Sweden)

    L.Canová

    2006-01-01

    Full Text Available The generalized Fisher super-exchange antiferromagnetic model with uniaxial crystal-field anisotropy is exactly investigated using an extended mapping technique. An exact relation between partition function of the studied system and that of the standard zero-field spin-1/2 Ising model on the corresponding lattice is obtained applying the decoration-iteration transformation. Consequently, exact results for all physical quantities are derived for arbitrary spin values S of decorating atoms. Particular attention is paid to the investigation of the effect of crystal-field anisotropy and external longitudinal magnetic field on magnetic properties of the system under investigation. The most interesting numerical results for ground-state and finite-temperature phase diagrams, thermal dependences of the sublattice magnetization and other thermodynamic quantities are discussed.

  10. Social Learning in the Real-World: ‘Over-Imitation’ Occurs in Both Children and Adults Unaware of Participation in an Experiment and Independently of Social Interaction

    Science.gov (United States)

    Whiten, Andrew; Allan, Gillian; Devlin, Siobahn; Kseib, Natalie; Raw, Nicola; McGuigan, Nicola

    2016-01-01

    The current study avoided the typical laboratory context to determine instead whether over-imitation—the disposition to copy even visibly, causally unnecessary actions—occurs in a real-world context in which participants are unaware of being in an experiment. We disguised a puzzle-box task as an interactive item available to the public within a science engagement zone of Edinburgh Zoo. As a member of the public approached, a confederate acting as a zoo visitor retrieved a reward from the box using a sequence of actions containing both causally relevant and irrelevant elements. Despite the absence of intentional demonstration, or social pressure to copy, a majority of both child and even adult observers included all causally irrelevant actions in their reproduction. This occurred even though causal irrelevance appeared manifest because of the transparency of the puzzle-box. That over-imitation occurred so readily in a naturalistic context, devoid of social interaction and pressure, suggests that humans are opportunistic social learners throughout the lifespan, copying the actions of other individuals even when these actions are not intentionally demonstrated, and their causal significance is not readily apparent. The disposition to copy comprehensively, even when a mere onlooker, likely provides humans, irrespective of their age, with a powerful mechanism to extract maximal information from the social environment. PMID:27466806

  11. Effects of energy correlations and superexchange on charge transport and exciton formation in amorphous molecular semiconductors: An ab initio study

    Science.gov (United States)

    Massé, Andrea; Friederich, Pascal; Symalla, Franz; Liu, Feilong; Meded, Velimir; Coehoorn, Reinder; Wenzel, Wolfgang; Bobbert, Peter A.

    2017-03-01

    In this study, we investigate on the basis of ab initio calculations how the morphology, molecular on-site energies, reorganization energies, and charge transfer integral distribution affect the hopping charge transport and the exciton formation process in disordered organic semiconductors. We focus on three materials applied frequently in organic light-emitting diodes: α -NPD , TCTA, and Spiro-DPVBi. Spatially correlated disorder and, more importantly, superexchange contributions to the transfer integrals, are found to give rise to a significant increase of the electric field dependence of the electron and hole mobility. Furthermore, a material-specific correlation is found between the HOMO and LUMO energy on each specific molecular site. For α -NPD and TCTA, we find a positive correlation between the HOMO and LUMO energies, dominated by a Coulombic contribution to the energies. In contrast, Spiro-DPVBi shows a negative correlation, dominated by a conformational contribution. The size and sign of this correlation have a strong influence on the exciton formation rate.

  12. Does Interaction between the Motor and Regulatory Domains of the Myosin Head Occur during ATPase Cycle? Evidence from Thermal Unfolding Studies on Myosin Subfragment 1.

    Directory of Open Access Journals (Sweden)

    Daria S Logvinova

    Full Text Available Myosin head (myosin subfragment 1, S1 consists of two major structural domains, the motor (or catalytic domain and the regulatory domain. Functioning of the myosin head as a molecular motor is believed to involve a rotation of the regulatory domain (lever arm relative to the motor domain during the ATPase cycle. According to predictions, this rotation can be accompanied by an interaction between the motor domain and the C-terminus of the essential light chain (ELC associated with the regulatory domain. To check this assumption, we applied differential scanning calorimetry (DSC combined with temperature dependences of fluorescence to study changes in thermal unfolding and the domain structure of S1, which occur upon formation of the ternary complexes S1-ADP-AlF4- and S1-ADP-BeFx that mimic S1 ATPase intermediate states S1**-ADP-Pi and S1*-ATP, respectively. To identify the thermal transitions on the DSC profiles (i.e. to assign them to the structural domains of S1, we compared the DSC data with temperature-induced changes in fluorescence of either tryptophan residues, located only in the motor domain, or recombinant ELC mutants (light chain 1 isoform, which were first fluorescently labeled at different positions in their C-terminal half and then introduced into the S1 regulatory domain. We show that formation of the ternary complexes S1-ADP-AlF4- and S1-ADP-BeFx significantly stabilizes not only the motor domain, but also the regulatory domain of the S1 molecule implying interdomain interaction via ELC. This is consistent with the previously proposed concepts and also adds some new interesting details to the molecular mechanism of the myosin ATPase cycle.

  13. Single-cell Hi-C for genome-wide detection of chromatin interactions that occur simultaneously in a single cell.

    Science.gov (United States)

    Nagano, Takashi; Lubling, Yaniv; Yaffe, Eitan; Wingett, Steven W; Dean, Wendy; Tanay, Amos; Fraser, Peter

    2015-12-01

    Hi-C is a powerful method that provides pairwise information on genomic regions in spatial proximity in the nucleus. Hi-C requires millions of cells as input and, as genome organization varies from cell to cell, a limitation of Hi-C is that it only provides a population average of genome conformations. We developed single-cell Hi-C to create snapshots of thousands of chromatin interactions that occur simultaneously in a single cell. To adapt Hi-C to single-cell analysis, we modified the protocol to include in-nucleus ligation. This enables the isolation of single nuclei carrying Hi-C-ligated DNA into separate tubes, followed by reversal of cross-links, capture of biotinylated ligation junctions on streptavidin-coated magnetic beads and PCR amplification of single-cell Hi-C libraries. The entire laboratory protocol can be carried out in 1 week, and although we have demonstrated its use in mouse T helper (TH1) cells, it should be applicable to any cell type or species for which standard Hi-C has been successful. We also developed an analysis pipeline to filter noise and assess the quality of data sets in a few hours. Although the interactome maps produced by single-cell Hi-C are sparse, the data provide useful information to understand cellular variability in nuclear genome organization and chromosome structure. Standard wet and dry laboratory skills in molecular biology and computational analysis are required.

  14. Single-molecule magnet behavior for an antiferromagnetically superexchange-coupled dinuclear dysprosium(III) complex.

    Science.gov (United States)

    Long, Jérôme; Habib, Fatemah; Lin, Po-Heng; Korobkov, Ilia; Enright, Gary; Ungur, Liviu; Wernsdorfer, Wolfgang; Chibotaru, Liviu F; Murugesu, Muralee

    2011-04-13

    A family of five dinuclear lanthanide complexes has been synthesized with general formula [Ln(III)(2)(valdien)(2)(NO(3))(2)] where (H(2)valdien = N1,N3-bis(3-methoxysalicylidene)diethylenetriamine) and Ln(III) = Eu(III)1, Gd(III)2, Tb(III)3, Dy(III)4, and Ho(III)5. The magnetic investigations reveal that 4 exhibits single-molecule magnet (SMM) behavior with an anisotropic barrier U(eff) = 76 K. The step-like features in the hysteresis loops observed for 4 reveal an antiferromagnetic exchange coupling between the two dysprosium ions. Ab initio calculations confirm the weak antiferromagnetic interaction with an exchange constant J(Dy-Dy) = -0.21 cm(-1). The observed steps in the hysteresis loops correspond to a weakly coupled system similar to exchange-biased SMMs. The Dy(2) complex is an ideal candidate for the elucidation of slow relaxation of the magnetization mechanism seen in lanthanide systems.

  15. The magnetic structures of double tungstates, NaM(WO{sub 4}){sub 2}, M=Fe, Cr: Examples for superexchange couplings mediated by [NaO{sub 6}]-octahedra

    Energy Technology Data Exchange (ETDEWEB)

    Nyam-Ochir, L. [School of Physics and Electronics, National University of Mongolia, 210646 Ulaanbaatar (Mongolia); Institute for Materials Science, Darmstadt University of Technology, D-64287 Darmstadt (Germany); Ehrenberg, H. [Institute for Materials Science, Darmstadt University of Technology, D-64287 Darmstadt (Germany); Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany)], E-mail: h.ehrenberg@ifw-dresden.de; Buchsteiner, A. [Hahn Meitner Institute Berlin, D-14092 Berlin (Germany); Senyshyn, A.; Fuess, H. [Institute for Materials Science, Darmstadt University of Technology, D-64287 Darmstadt (Germany); Sangaa, D. [School of Physics and Electronics, National University of Mongolia, 210646 Ulaanbaatar (Mongolia)

    2008-12-15

    The crystal structures of the double tungstates NaM(WO{sub 4}){sub 2} with M=Fe, Cr and their solid solution are similar to the wolframite-type structure in the space group P2/c, but with doubled a lattice parameter. Magnetization and neutron-diffraction data reveal that NaFe(WO{sub 4}){sub 2} orders antiferromagnetically below 5 K with a commensurate propagation vector k=(1/2 ,1/2 ,1/2 ) and magnetic moments of Fe{sup 3+} ions oriented along the a-axis. NaCr(WO{sub 4}){sub 2} is antiferromagnetic below 10 K. Its magnetic structure is based on the propagation vector k=(1/2 ,1/2 ,0), and the magnetic moments of Cr{sup 3+} ions are aligned along the b-axis. The magnetic structure in the bc-plane is explained by a supersuperexchange mechanism. Long-range magnetic superexchange interactions along paths including [NaO{sub 6}]-octahedra are necessary to explain the observed magnetic structures. Mixed NaFe{sub x}Cr{sub 1-x}(WO{sub 4}){sub 2}, with x=0.25, 0.5, 0.75, do not indicate magnetic order, neither in magnetization nor neutron-diffraction data.

  16. Long-range superexchange in Cu2A2O7 (A= P, As, V) as a key element of the microscopic magnetic model

    Science.gov (United States)

    Janson, O.; Tsirlin, A. A.; Sichelschmidt, J.; Skourski, Y.; Weickert, F.; Rosner, H.

    2011-03-01

    A microscopic magnetic model for α-Cu2P2O7 is evaluated in a combined theoretical and experimental study. Despite a dominant intradimer coupling J1, sizable interdimer couplings enforce long-range magnetic ordering at TN=27 K. The spin model for α-Cu2P2O7 is compared to the models of the isostructural β-Cu2V2O7 and α-Cu2As2O7 systems. As a surprise, coupled dimers in α-Cu2P2O7 and alternating chains in α-Cu2As2O7 contrast with a honeycomb lattice in β-Cu2V2O7. We find that the qualitative difference in the coupling regime of these isostructural compounds is governed by the nature of AO4 side groups: d elements (A=V) hybridize with nearby O atoms forming a Cu-O-A-O-Cu superexchange path, while for p elements (A= P, As) the superexchange is realized via O-O edges of the tetrahedron. Implications for a broad range of systems are discussed.

  17. Magnetic interactions in La{sub 0.7}Sr{sub 0.3}Mn{sub 1−x}Me{sub x}O{sub 3} (Me=Ga, Fe, Cr) manganites

    Energy Technology Data Exchange (ETDEWEB)

    Troyanchuk, I.O., E-mail: troyan@physics.by [Scientific-Practical Materials Research Centre of NAS of Belarus, P. Brovki str. 19, 220072 Minsk (Belarus); Bushinsky, M.V.; Karpinsky, D.V.; Tereshko, N.V. [Scientific-Practical Materials Research Centre of NAS of Belarus, P. Brovki str. 19, 220072 Minsk (Belarus); Dobryansky, V.M. [Belarussian State Agrarian Technical University, Nezavisimosti av. 99, 220023 Minsk (Belarus); Többens, D.M. [Helmholt-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Sikolenko, V. [Helmholt-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation); Efimov, V. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation)

    2015-11-15

    Magnetic properties and crystal structure of La{sub 0.7}Sr{sub 0.3}Mn{sub 1−x}Me{sub x}O{sub 3} (Me=Ga, Fe, Cr; x≤0.3) have been studied by neutron powder diffraction and magnetization measurements. It is shown that substitution of manganese ions by chromium or gallium ions (x=0.3) leads to phase separation into antiferromagnetic and ferromagnetic phases whereas replacement by Fe ions stabilizes spin glass state (x=0.3). Ferromagnetic interactions in Cr-substituted compounds are much more pronounced than in Fe- and Ga-doped ones. Magnetic properties are discussed in the model assuming a dominance of superexchange interactions. It is considered that ferromagnetism in the Cr-substituted compositions is associated with nearly equal contributions from positive and negative components of the superexchange interaction between Mn{sup 3+} and Cr{sup 3+} ions as well as to mixed valence of chromium ions. The spin glass state observed for the Fe-doped sample (x=0.3) is associated with strong antiferromagnetic superexchange between Fe{sup 3+}–O–Fe{sup 3+} and Fe{sup 3+}–O–(Mn{sup 3+}, Mn{sup 4+}). - Highlights: • Magnetic structure of the compounds has been clarified by NPD. • Magnetic properties of the compounds has been explained using superexchange scenario. • Mn–O–Fe and Fe–O–Fe superexchange interactions are strongly antiferromagnetic.

  18. ER EXPORT AND SURFACE TARGETING OF THE DOPAMINE TRANSPORTER ARE DEPENDENT ON THE DISTAL C-TERMINUS BUT OCCURS INDEPENDENTLY OF PDZ DOMAIN INTERACTIONS

    DEFF Research Database (Denmark)

    Bjerggaard(Vægter), Christian; Loland, Claus; Hastrup, Hanne

    . Neuron 2001, 30:121-34). As expected, we find that deletion of the PDZ binding sequence (LKV) or substitution with three histidines resulted in retention of hDAT in the ER in both HEK293 and N2A neuroblastoma cells. However, substitution of LKV with the type 2 PDZ binding sequence SLL of the beta2......- adrenergic receptor, which does not bind PICK1, did not affect membrane targeting. In addition, neither C-terminal addition of a tyrosine, an alanine nor the sequence RGS-6XHis affected significantly surface targeting of the hDAT. Since interactions with PDZ domains are dependent on the presence of a free C......-terminal carboxylic acid, these data are inconsistent with involvement of such interactions in ER export/surface targeting of hDAT. Furthermore, progressive substitution of hDAT C-terminus with beta2- adrenergic receptor sequence beyond the tolerated C-terminal SLL-sequence caused intracellular retention suggesting...

  19. Ferromagnetic exchange anisotropy from antiferromagnetic superexchange in the mixed 3d-5d transition-metal compound Sr3CuIrO6.

    Science.gov (United States)

    Yin, Wei-Guo; Liu, X; Tsvelik, A M; Dean, M P M; Upton, M H; Kim, Jungho; Casa, D; Said, A; Gog, T; Qi, T F; Cao, G; Hill, J P

    2013-08-02

    We report a combined experimental and theoretical study of the unusual ferromagnetism in the one-dimensional copper-iridium oxide Sr(3)CuIrO(6). Utilizing Ir L(3) edge resonant inelastic x-ray scattering, we reveal a large gap magnetic excitation spectrum. We find that it is caused by an unusual exchange anisotropy generating mechanism, namely, strong ferromagnetic anisotropy arising from antiferromagnetic superexchange, driven by the alternating strong and weak spin-orbit coupling on the 5d Ir and 3d Cu magnetic ions, respectively. From symmetry consideration, this novel mechanism is generally present in systems with edge-sharing Cu(2+)O(4) plaquettes and Ir(4+)O(6) octahedra. Our results point to unusual magnetic behavior to be expected in mixed 3d-5d transition-metal compounds via exchange pathways that are absent in pure 3d or 5d compounds.

  20. Diffusing wave spectroscopy study of the colloidal interactions occurring between casein micelles and emulsion droplets: comparison to hard-sphere behavior.

    Science.gov (United States)

    Gaygadzhiev, Zafir; Corredig, Milena; Alexander, Marcela

    2008-04-15

    Understanding the underlying processes that govern interparticle interactions in colloidal systems is fundamental to predicting changes in their bulk properties. In this paper we discuss the colloidal behavior of casein micelles and protein-stabilized fat globules individually and in a mixture. The colloidal interactions were observed by transmission diffusing wave spectroscopy. The turbidity parameter, l*, and the diffusion coefficients of the samples studied were measured experimentally and compared to the theoretically calculated parameters for a hard-sphere system. The light scattering properties of casein micelles (volume fraction phi = 0.1-0.2) dispersed in milk permeate showed no deviation from the theoretically predicted model. Whey protein isolate (WPI)-stabilized emulsions (phi = 0.025-0.1) prepared either in milk permeate or in 5 mM imidazole buffer at pH 6.8 showed a behavior identical to that of the hard-sphere model. Similarly to the WPI-stabilized fat globules, the sodium caseinate (NaCas)-stabilized emulsions (phi = 0.025-0.1) prepared in milk permeate also showed resemblance to the theory. In contrast, NaCas-stabilized emulsions prepared in 5 mM imidazole buffer exhibited some discrepancy from the theoretically calculated parameters. The deviation from theory is attributed to the enhanced steric stabilization properties of these droplets in a low ionic strength environment. When recombined milks made from concentrated milk and WPI- and NaCas-stabilized droplets prepared in permeate (phi = 0.125-0.2) were studied, the experimental data showed a significant deviation from the theoretical behavior of a hard-sphere model due to mixing of two different species.

  1. Large-scale impacts of multiple co-occurring invaders on monkey puzzle forest regeneration, native seed predators and their ecological interactions

    Directory of Open Access Journals (Sweden)

    José L. Tella

    2016-04-01

    Full Text Available Most ecosystems of the world are being increasingly invaded by a variety of alien species. However, little is known about the combined ecological impacts of multiple co-occurring invaders. We assessed the impact of a community of exotic mammals (five domestic and four wild on forests of monkey puzzle (Araucaria araucana, a globally endangered tree restricted to ca 400 km2 on the slopes of the Andes in Chile and Argentina. Seeds of monkey puzzles provide food during winter to a small community of native mice and Austral parakeets (Enicognathus ferrugineus. We recorded the number of uneaten seeds and the number of young seedlings at the end of winter under 516 female monkey puzzle trees located across the species’ distribution, and identified the signals of native and exotic species that visited the under-canopy of each tree. Moreover, we studied the diet and foraging behavior of Austral parakeets to explore the potential indirect effects of exotic mammals through the disruption of a key ecosystem service (seed dispersal supposedly provided by parakeets. All but one tree were visited by at least one seed predator species. Austral parakeets and mice predated seeds from 85% and at least 45% of the trees, respectively, and both the number of remaining seeds and seedlings were significantly larger when only parakeets or mice predated seeds than when exotic mammals also visited the trees. At least 90% of trees were visited by one or more exotic species, and the number of seeds and seedlings dropped drastically when at least two and four exotic species visited the tree, respectively. Austral parakeets mostly foraged on monkey puzzle trees during the winter period and dispersed their seeds in most feeding instances once seeds fell to the ground. The proliferation of exotic mammals may reduce the populations of native seed-predators in the long-term as well as the regeneration of monkey puzzle forests, directly through a reduction of seed availability

  2. Entanglement of charge transfer, hole doping, exchange interaction, and octahedron tilting angle and their influence on the conductivity of La1-xSrxFe0.75Ni0.25O3-δ: A combination of x-ray spectroscopy and diffraction

    Science.gov (United States)

    Erat, Selma; Braun, Artur; Piamonteze, Cinthia; Liu, Zhi; Ovalle, Alejandro; Schindler, Hansjürgen; Graule, Thomas; Gauckler, Ludwig J.

    2010-12-01

    Substitution of La by Sr in the 25% Ni doped charge transfer insulator LaFeO3 leads to structural changes that inflect the electrical conductivity, which is caused by small polaron hopping via charge transfer and exchange interactions. The substitution forms electron holes and causes a structural transition from orthorhombic to rhombohedral symmetry, and then to cubic symmetry. The structural crossover is accompanied by a crossover from the Fe3+-O2--Fe3+ superexchange interaction to the Fe3+-O2--Fe4+ double exchange interaction in the course of substitution, as evidenced by a considerable increase in the conductivity at ambient temperature. The charge transfer and exchange interactions depend on the superexchange angle, which approaches 180° upon increasing Sr concentration. An increase in superexchange angle leads to an increase in overlapping between the O 2p and the Fe/Ni 3d orbitals.

  3. Validity and limitations of the superexchange model for the magnetic properties of Sr2IrO4 and Ba2IrO4 mediated by the strong spin-orbit coupling

    Science.gov (United States)

    Solovyev, I. V.; Mazurenko, V. V.; Katanin, A. A.

    2015-12-01

    Layered perovskites Sr2IrO4 and Ba2IrO4 are regarded as the key materials for understanding the properties of magnetic relativistic insulators, mediated by the strong spin-orbit (SO) coupling. One of the most fundamental issues is to which extent these properties can be described by the superexchange (SE) model, formulated in the limit of the large Coulomb repulsion for some appropriately selected pseudospin states, and whether these materials themselves can be classified as Mott insulators. In this work, we address these issues by deriving the relevant models and extracting parameters of these models from the electronic-structure calculations with the SO coupling, based on the density functional theory. First, we construct the effective Hubbard-type model for the magnetically active t2 g bands, by recasting the problem in the language of localized Wannier orbitals. Then, we map the obtained electron model onto the pseudospin model by applying the theory of SE interactions, which is based on the second-order perturbation theory with respect to the transfer integrals. We discuss the microscopic origin of anisotropic SE interactions, inherent to the compass Heisenberg model, and the appearance of the antisymmetric Dzyaloshinskii-Moriya term, associated with the additional rotation of the IrO6 octahedra in Sr2IrO4 . In order to solve the pseudospin Hamiltonian problem and evaluate the Néel temperature (TN), we employ the nonlinear sigma model. We have found that, while for Sr2IrO4 our value of TN agrees with the experimental data, for Ba2IrO4 it is overestimated by a factor of 2. We argue that this discrepancy is related to limitations of the SE model: while for more localized t2 g states in Sr2IrO4 it works reasonably well, the higher-order terms in the perturbation theory expansion play a more important role in the more "itinerant" Ba2IrO4 , giving rise to the new type of isotropic and anisotropic exchange interactions, which are not captured by the SE model. This

  4. When Yawning Occurs in Elephants

    Science.gov (United States)

    Rossman, Zoë T.; Hart, Benjamin L.; Greco, Brian J.; Young, Debbie; Padfield, Clare; Weidner, Lisa; Gates, Jennifer; Hart, Lynette A.

    2017-01-01

    Yawning is a widely recognized behavior in mammalian species. One would expect that elephants yawn, although to our knowledge, no one has reported observations of yawning in any species of elephant. After confirming a behavioral pattern matching the criteria of yawning in two Asian elephants (Elephas maximus) in a zoological setting, this study was pursued with nine captive African elephants (Loxodonta africana) at a private reserve in the Western Cape, South Africa, the Knysna Elephant Park. Observations were made in June–September and in December. In the daytime, handlers managed seven of the elephants for guided interactions with visitors. At night, all elephants were maintained in a large enclosure with six having limited outdoor access. With infrared illumination, the elephants were continuously recorded by video cameras. During the nights, the elephants typically had 1–3 recumbent sleeping/resting bouts, each lasting 1–2 h. Yawning was a regular occurrence upon arousal from a recumbency, especially in the final recumbency of the night. Yawning was significantly more frequent in some elephants. Yawning was rare during the daytime and during periods of standing around in the enclosure at night. In six occurrences of likely contagious yawning, one elephant yawned upon seeing another elephant yawning upon arousal from a final recumbency; we recorded the sex and age category of the participants. The generality of yawning in both African and Asian elephants in other environments was documented in video recordings from 39 zoological facilities. In summary, the study provides evidence that yawning does occur in both African and Asian elephants, and in African elephants, yawning was particularly associated with arousal from nighttime recumbencies. PMID:28293560

  5. Interaction of ubiquitin ligase CBL with LMP2A protein of Epstein-Barr virus occurs via PTB domain of CBL and does not depend on adaptor ITSN1

    Directory of Open Access Journals (Sweden)

    Dergai O. V.

    2013-03-01

    Full Text Available Aim. Previously Latent membrane protein 2A (LMP2A of Epstein-Barr virus was found to be ubiquitylated by CBL ubiquitin ligase but no direct interaction of LMP2A with CBL was reported. We aimed to explore this interaction and study a possibility of adaptor protein involvement. Taking into consideration that both LMP2A and CBL were shown to interact with endocytic adaptor protein intersectin 1 (ITSN1, we assumed that the latter could serve as a scaffold for LMP2A/CBL complex. Methods. We used an immunofluorescence and coimmuno- precipitation approaches to test a mutual complex formation of ITSN1, CBL and LMP2A proteins. Results. LMP2A coimmunoprecipitated with CBL while LMP2A did not interact with CBL G306E mutant harboring inactive phosphotyrosine-binding domain. We observed a triple colocalization of ITSN1, CBL and LMP2A signals in MCF-7 cells as well as coprecipitation of all mentioned proteins. Overexpression of ITSN1 did not affect the efficiency of complex formation of LMP2A with CBL. Moreover, LMP2A mutant unable to interact with ITSN1 was readily precipitated with CBL. Conclusions. LMP2A can be engaged in the complex together with endocytic adaptor ITSN1 and ubiquitin ligase CBL. We show that PTB domain of CBL is responsible for interaction with LMP2A. ITSN1 is not required for LMP2A recruiting to CBL.

  6. Myasis occuring in a neonate

    Science.gov (United States)

    Obasa, Temitope O.; Sowunmi, Funmilola Olusola

    2012-01-01

    Myasis is the infestation of skin by larvae or maggots of a variety of flies. It is a condition that occurs more commonly in adults who are living and/or have visited tropical countries. It rarely occurs in neonates, and even when seen, only few larvae are extracted. This case report describes myasis occurring in an 11-day-old female who had 47 larvae in her skin. PMID:23355934

  7. Myasis occuring in a neonate

    Directory of Open Access Journals (Sweden)

    Temitope O. Obasa

    2012-12-01

    Full Text Available Myasis is the infestation of skin by larvae or maggots of a variety of flies. It is a condition that occurs more commonly in adults who are living and/or have visited tropical countries. It rarely occurs in neonates, and even when seen, only few larvae are extracted. This case report describes myasis occurring in an 11-day-old female who had 47 larvae in her skin.

  8. Unique cellular events occurring during the initial interaction of macrophages with matrix-retained or methylated aggregated low density lipoprotein (LDL). Prolonged cell-surface contact during which ldl-cholesteryl ester hydrolysis exceeds ldl protein degradation.

    Science.gov (United States)

    Buton, X; Mamdouh, Z; Ghosh, R; Du, H; Kuriakose, G; Beatini, N; Grabowski, G A; Maxfield, F R; Tabas, I

    1999-11-05

    A critical event in atherogenesis is the interaction of arterial wall macrophages with subendothelial lipoproteins. Although most studies have investigated this interaction by incubating cultured macrophages with monomeric lipoproteins dissolved in media, arterial wall macrophages encounter lipoproteins that are mostly bound to subendothelial extracellular matrix, and these lipoproteins are often aggregated or fused. Herein, we utilize a specialized cell-culture system to study the initial interaction of macrophages with aggregated low density lipoprotein (LDL) bound to extracellular matrix. The aggregated LDL remains extracellular for a relatively prolonged period of time and becomes lodged in invaginations in the surface of the macrophages. As expected, the degradation of the protein moiety of the LDL was very slow. Remarkably, however, hydrolysis of the cholesteryl ester (CE) moiety of the LDL was 3-7-fold higher than that of the protein moiety, in stark contrast to the situation with receptor-mediated endocytosis of acetyl-LDL. Similar results were obtained using another experimental system in which the degradation of aggregated LDL protein was delayed by LDL methylation rather than by retention on matrix. Additional experiments indicated the following properties of this interaction: (a) LDL-CE hydrolysis is catalyzed by lysosomal acid lipase; (b) neither scavenger receptors nor the LDL receptor appear necessary for the excess LDL-CE hydrolysis; and (c) LDL-CE hydrolysis in this system is resistant to cellular potassium depletion, which further distinguishes this process from receptor-mediated endocytosis. In summary, experimental systems specifically designed to mimic the in vivo interaction of arterial wall macrophages with subendothelial lipoproteins have demonstrated an initial period of prolonged cell-surface contact in which CE hydrolysis exceeds protein degradation.

  9. A network of cancer genes with co-occurring and anti-co-occurring mutations.

    Directory of Open Access Journals (Sweden)

    Qinghua Cui

    Full Text Available Certain cancer genes contribute to tumorigenesis in a manner of either co-occurring or mutually exclusive (anti-co-occurring mutations; however, the global picture of when, where and how these functional interactions occur remains unclear. This study presents a systems biology approach for this purpose. After applying this method to cancer gene mutation data generated from large-scale and whole genome sequencing of cancer samples, a network of cancer genes with co-occurring and anti-co-occurring mutations was constructed. Analysis of this network revealed that genes with co-occurring mutations prefer direct signaling transductions and that the interaction relations among cancer genes in the network are related with their functional similarity. It was also revealed that genes with co-occurring mutations tend to have similar mutation frequencies, whereas genes with anti-co-occurring mutations tend to have different mutation frequencies. Moreover, genes with more exons tend to have more co-occurring mutations with other genes, and genes having lower local coherent network structures tend to have higher mutation frequency. The network showed two complementary modules that have distinct functions and have different roles in tumorigenesis. This study presented a framework for the analysis of cancer genome sequencing outputs. The presented data and uncovered patterns are helpful for understanding the contribution of gene mutations to tumorigenesis and valuable in the identification of key biomarkers and drug targets for cancer.

  10. Angiodysplasia Occurring in Jejunal Diverticulosis

    OpenAIRE

    Edward A Jones; Hugh Chaun; Phillip Switzer; David J Clow; Ronald J Hancock

    1990-01-01

    The first case of angiodysplasia occurring in acquired jejunal diverticulosis is reported. The patient presented with occult gastrointestinal bleeding and chronic anemia, and was created successfully by resection of a 25 cm long segment of jejunum. Possible pathogenetic mechanisms for both angiodysplasia and jejunal diverticulosis are discussed.

  11. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions...... interaction between a human operator and an artificial actor or agent. We can apply insights from puppetry to develop culturally-aware robots. Here we describe the development of a robotic marionette theatre wherein robotic controllers assume the role of human puppeteers. The system has been built, tested...

  12. Naturally Occurring Radioactive Materials (NORM)

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P. [ed.

    1997-02-01

    This paper discusses the broad problems presented by Naturally Occuring Radioactive Materials (NORM). Technologically Enhanced naturally occuring radioactive material includes any radionuclides whose physical, chemical, radiological properties or radionuclide concentration have been altered from their natural state. With regard to NORM in particular, radioactive contamination is radioactive material in an undesired location. This is a concern in a range of industries: petroleum; uranium mining; phosphorus and phosphates; fertilizers; fossil fuels; forestry products; water treatment; metal mining and processing; geothermal energy. The author discusses in more detail the problem in the petroleum industry, including the isotopes of concern, the hazards they present, the contamination which they cause, ways to dispose of contaminated materials, and regulatory issues. He points out there are three key programs to reduce legal exposure and problems due to these contaminants: waste minimization; NORM assesment (surveys); NORM compliance (training).

  13. Arsenic-bridged magnetic interactions in an emerging two-dimensional FeAs nanostructure on MnAs

    Science.gov (United States)

    Helman, Christian; Ferrari, Valeria; Llois, Ana Maria

    2015-08-01

    The extreme case of an Fe monolayer deposited onto a manganese arsenide (MnAs) substrate is analyzed using density functional theory. We find that an FeAs quasi-two-dimensional antiferromagnetic surface nanostructure emerges. This nanostructure, which is magnetically nearly decoupled from the substrate, is due to bonding effects arising from the arsenic atoms bridging the Fe magnetic interactions. These interactions are studied and modeled using a Heisenberg-type Hamiltonian. They display an angular dependence which is characteristic of superexchange-like interactions, which are of the same order of magnitude as those appearing in Fe-based pnictides.

  14. Interactions

    DEFF Research Database (Denmark)

    The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists...... such as Lorentz and Einstein as well as mathematicians such as Poincare, Minkowski, Hilbert and Weyl contributed to this development. They created the new physical theories and the mathematical disciplines that play such paramount roles in their mathematical formulations. These physicists and mathematicians were...

  15. Systemic PCD occurs in TMV-tomato interaction

    Institute of Scientific and Technical Information of China (English)

    ZHOU ShuMin; LIU WenNa; KONG LinAn; WANG Mao

    2008-01-01

    In hypersensitive response (HR), programmed cell death (POD) is reported as a powerful defense mechanism in plant immune responses to pathogen. However, little is known about the POD in sys-temic acquired resistance (SAR). Using tobacco mosaic virus (TMV) to infect the tomato (Lycopersicon esculentum cv. Jiafen 16) we found that localized TMV-infection could induce cell death in the uninoculated parts of the tomatoes, where the enzyme-linked immunosorbent assay (ELISA) showed no spreading virus. The biological and molecular characterization of this cell death was shown as fol-lowing: chromatin condensed and formed peripheral conglomeration in nuclei; cell nucleus were TUNEL positive labeled; genomic DNA was fragmented and showed DNA laddering; mitochondria and chloroplast were disrupted; tonoplast and plasma membrane were shrunk and degradated. These re-suits suggested that with an absence of TMV spread, the local TMV-infection on certain tomato leaves could induce systemic PCD in the root-tips, stem-apices and uninoculated leaves. The systemic PCD has various initiation and synchronization in such tissues and is distinct in inducement and exhibition from HR-PCD and SAR.

  16. Systemic PCD occurs in TMV-tomato interaction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In hypersensitive response (HR), programmed cell death (PCD) is reported as a powerful defense mechanism in plant immune responses to pathogen. However, little is known about the PCD in sys-temic acquired resistance (SAR). Using tobacco mosaic virus (TMV) to infect the tomato (Lycopersicon esculentum cv. Jiafen 16) we found that localized TMV-infection could induce cell death in the uninoculated parts of the tomatoes, where the enzyme-linked immunosorbent assay (ELISA) showed no spreading virus. The biological and molecular characterization of this cell death was shown as fol-lowing: chromatin condensed and formed peripheral conglomeration in nuclei; cell nucleus were TUNEL positive labeled; genomic DNA was fragmented and showed DNA laddering; mitochondria and chloroplast were disrupted; tonoplast and plasma membrane were shrunk and degradated. These re-sults suggested that with an absence of TMV spread, the local TMV-infection on certain tomato leaves could induce systemic PCD in the root-tips, stem-apices and uninoculated leaves. The systemic PCD has various initiation and synchronization in such tissues and is distinct in inducement and exhibition from HR-PCD and SAR.

  17. Systemic PCD occurs in TMV-tomato interaction.

    Science.gov (United States)

    Zhou, ShuMin; Liu, WenNa; Kong, LinAn; Wang, Mao

    2008-11-01

    In hypersensitive response (HR), programmed cell death (PCD) is reported as a powerful defense mechanism in plant immune responses to pathogen. However, little is known about the PCD in systemic acquired resistance (SAR). Using tobacco mosaic virus (TMV) to infect the tomato (Lycopersicon esculentum cv. Jiafen 16) we found that localized TMV-infection could induce cell death in the uninoculated parts of the tomatoes, where the enzyme-linked immunosorbent assay (ELISA) showed no spreading virus. The biological and molecular characterization of this cell death was shown as following: chromatin condensed and formed peripheral conglomeration in nuclei; cell nucleus were TUNEL positive labeled; genomic DNA was fragmented and showed DNA laddering; mitochondria and chloroplast were disrupted; tonoplast and plasma membrane were shrunk and degradated. These results suggested that with an absence of TMV spread, the local TMV-infection on certain tomato leaves could induce systemic PCD in the root-tips, stem-apices and uninoculated leaves. The systemic PCD has various initiation and synchronization in such tissues and is distinct in inducement and exhibition from HR-PCD and SAR.

  18. Tetrahydroberberine, a pharmacologically active naturally occurring alkaloid.

    Science.gov (United States)

    Pingali, Subramanya; Donahue, James P; Payton-Stewart, Florastina

    2015-04-01

    Tetrahydroberberine (systematic name: 9,10-dimethoxy-5,8,13,13a-tetrahydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the molecule is observed, with an angle of 24.72 (5)° between the arene rings at the two ends of the reduced quinolizinium core. The intermolecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole -CH2···OCH3 and -OCH3···OCH3 interactions between neighboring molecules.

  19. Spectroscopic demonstration of a large antisymmetric exchange contribution to the spin-frustrated ground state of a D3 symmetric hydroxy-bridged trinuclear Cu(II) complex: ground-to-excited state superexchange pathways.

    Science.gov (United States)

    Yoon, Jungjoo; Mirica, Liviu M; Stack, T Daniel P; Solomon, Edward I

    2004-10-06

    The magnetic and electronic properties of a spin-frustrated ground state of an antiferromagnetically coupled 3-fold symmetric trinuclear copper complex (TrisOH) is investigated using a combination of variable-temperature variable-field magnetic circular dichroism (VTVH MCD) and powder/single-crystal EPR. Direct evidence for a low-lying excited S = (1)/(2) state from the zero-field split ground (2)E state is provided by the nonlinear dependence of the MCD intensity on 1/T and the nesting of the VTVH MCD isotherms. A consistent zero-field splitting (Delta) value of approximately 65 cm(-1) is obtained from both approaches. In addition, the strong angular dependence of the single-crystal EPR spectrum, with effective g-values from 2.32 down to an unprecedented 1.2, requires in-state spin-orbit coupling of the (2)E state via antisymmetric exchange. The observable EPR intensities also require lowering of the symmetry of the trimer structure, likely reflecting a magnetic Jahn-Teller effect. Thus, the Delta of the ground (2)E state is shown to be governed by the competing effects of antisymmetric exchange (G = 36.0 +/- 0.8 cm(-1)) and symmetry lowering (delta = 17.5 +/- 5.0 cm(-1)). G and delta have opposite effects on the spin distribution over the three metal sites where the former tends to delocalize and the latter tends to localize the spin of the S(tot) = (1)/(2) ground state on one metal center. The combined effects lead to partial delocalization, reflected by the observed EPR parallel hyperfine splitting of 74 x 10(-4) cm(-1). The origin of the large G value derives from the efficient superexchange pathway available between the ground d(x2-y2) and excited d(xy) orbitals of adjacent Cu sites, via strong sigma-type bonds with the in-plane p-orbitals of the bridging hydroxy ligands. This study provides significant insight into the orbital origin of the spin Hamiltonian parameters of a spin-frustrated ground state of a trigonal copper cluster.

  20. Ferromagnetic interactions between transition-metal impurities in topological and 3D Dirac semimetals

    Science.gov (United States)

    Dietl, Tomasz

    The magnitude of ferromagnetic coupling driven by inter-band (Bloembergen-Rowland - BR) and intra-band (Ruderman-Kittel-Kasuya-Yoshida - RKKY) spin polarization is evaluated within kp theory for topological semimetals Hg1-xMnxTe and Hg1-xMnxSe as well as for 3D Dirac semimetal (Cd1-xMnx)3As2. In these systems Mn2+ ions do not introduce any carriers. Since, however, both conduction and valence bands are built from anion p-type wave functions, hybridization of Mn d levels with neighboring anion p states leads to spin-dependent p - d coupling of both electrons and holes to localized Mn spins, resulting in sizable inter-band spin polarization and, thus in large BR interactions. We demonstrate that this ferromagnetic coupling, together with antiferromagnetic superexchange, elucidate a specific dependence of spin-glass freezing temperature on x, determined experimentally for these systems. Furthermore, by employing a multi-orbital tight-binding method, we find that superexchange becomes ferromagnetic when Mn is replaced by Cr or V. Since Cr should act as an isoelectronic impurity in HgTe, this opens a road for realization of ferromagnetic topological insulators based on (Hg,Cr)Te.

  1. Allergies and Asthma: They Often Occur Together

    Science.gov (United States)

    ... you miserable. A lot, as it turns out. Allergies and asthma often occur together. The same substances that trigger your hay fever symptoms, such as pollen, dust mites and pet dander, may also cause asthma signs ...

  2. Multiple Primary Cancers: Simultaneously Occurring Prostate ...

    African Journals Online (AJOL)

    2016-05-20

    May 20, 2016 ... occurring prostate cancer and other primary tumors-our experience and literature ... carcinoma, primary liver cell carcinoma, and thyroid follicular carcinoma in both ..... malignancies in women with papillary thyroid cancer.

  3. ST elevation occurring during stress testing

    Directory of Open Access Journals (Sweden)

    Diana Malouf

    2016-04-01

    Full Text Available A case is presented of significant reversible ST elevation occurring during treadmill testing, and the coronary anatomy and subsequent course are described, indicating that ischemia is a potential cause of this electrocardiographic finding.

  4. Trichotillomania and Co-occurring Anxiety

    Science.gov (United States)

    Grant, Jon E.; Redden, Sarah A.; Leppink, Eric W.; Chamberlain, Samuel R.

    2017-01-01

    Background Trichotillomania appears to be a fairly common disorder, with high rates of co-occurring anxiety disorders. Many individuals with trichotillomania also report that pulling worsens during periods of increased anxiety. Even with these clinical links to anxiety, little research has explored whether trichotillomania with co-occurring anxiety is a meaningful subtype. Methods 165 adults with trichotillomania were examined on a variety of clinical measures including symptom severity, functioning, and comorbidity. Participants also underwent cognitive testing assessing motor inhibition and cognitive flexibility. Clinical features and cognitive functioning were compared between those with current co-occurring anxiety disorders (i.e. social anxiety, generalized anxiety disorder, panic disorder, and anxiety disorder NOS) (n=38) and those with no anxiety disorder (n=127). Results Participants with trichotillomania and co-occurring anxiety reported significantly worse hair pulling symptoms, were more likely to have co-occurring depression, and were more likely to have a first-degree relative with obsessive compulsive disorder. Those with anxiety disorders also exhibited significantly worse motor inhibitory performance on a task of motor inhibition (stop-signal task). Conclusions This study suggests that anxiety disorders affect the clinical presentation of hair pulling behavior. Further research is needed to validate our findings and to consider whether treatments should be specially tailored differently for adults with trichotillomania who have co-occurring anxiety disorders, or more pronounced cognitive impairment. PMID:27668531

  5. Percieved functions of naturally occurring autobiographical memories

    DEFF Research Database (Denmark)

    Treebak, L. S.; Henriksen, J. R.; Lundhus, S.

    2005-01-01

    The main empirical reference on functions of autobiographical memories is still Hyman & Faries (1992) who used the cue-word-method and retrospective judgements. We used diaries to sample naturally occurring autobiographical memories and participants? perceived use of these. Results partly replicate...

  6. Exchange Interaction Effects on the Optical Properties of LuMnO3

    Science.gov (United States)

    Souchkov, A. B.; Simpson, J. R.; Quijada, M.; Ishibashi, H.; Hur, N.; Ahn, J. S.; Cheong, S. W.; Millis, A. J.; Drew, H. D.

    2003-07-01

    We have measured the optical conductivity of single crystal LuMnO3 from 10 to 45 000 cm-1 at temperatures between 4 and 300K. A symmetry allowed on-site Mn d-d transition near 1.7eV is observed to blueshift (˜0.1 eV) in the antiferromagnetic state due to Mn Mn superexchange interactions. Similar anomalies are observed in the temperature dependence of the TO phonon frequencies which arise from spin-phonon interaction. We find that the known anomaly in the temperature dependence of the quasistatic dielectric constant ɛ0 below TN˜90 K is overwhelmingly dominated by the phonon contributions.

  7. Magnetism and exchange interaction of small rare-earth clusters; Tb as a representative

    CERN Document Server

    Peters, Lars; Sanyal, Biplab; van Dijk, Chris; Bowlan, John; de Heer, Walt; Delin, Anna; Di Marco, Igor; Eriksson, Olle; Katsnelson, Mikhail I; Johansson, Börje; Kirilyuk, Andrei

    2016-01-01

    Here we follow, both experimentally and theoretically, the development of magnetism in Tb clusters from the atomic limit, adding one atom at a time. The exchange interaction is, surprisingly, observed to drastically increase compared to that of bulk, and to exhibit irregular oscillations as a function of the interatomic distance. From electronic structure theory we find that the theoretical magnetic moments oscillate with cluster size in exact agreement with experimental data. Unlike the bulk, the oscillation is not caused by the RKKY mechanism. Instead, the inter-atomic exchange is shown to be driven by a competition between wave-function overlap of the 5d shell and the on-site exchange interaction, which leads to a competition between ferromagnetic double-exchange and antiferromagnetic super-exchange. This understanding opens up new ways to tune the magnetic properties of rare-earth based magnets with nano-sized building blocks.

  8. Ethical issues occurring within nursing education.

    Science.gov (United States)

    Fowler, Marsha D; Davis, Anne J

    2013-03-01

    The large body of literature labeled "ethics in nursing education" is entirely devoted to curricular matters of ethics education in nursing schools, that is, to what ought to be the ethics content that is taught and what theory or issues ought to be included in all nursing curricula. Where the nursing literature actually focuses on particular ethical issues, it addresses only single topics. Absent from the literature, however, is any systematic analysis and explication of ethical issues or dilemmas that occur within the context of nursing education. The objective of this article is to identify the spectrum of ethical issues in nursing education to the end of prompting a systematic and thorough study of such issues, and to lay the groundwork for research by identifying and provisionally typologizing the ethical issues that occur within the context of academic nursing.

  9. Molten Metal Explosions are Still Occurring

    Science.gov (United States)

    2009-02-01

    pans which can give rise to Force 2 incidents if unheated or contain foreign matter. Handling hot dross represents a particular hazard. Force 3...explosions have occurred from hot dross transfer, cooling and dumping into storage areas. In one recent incident, an employee reportedly dumped a load of...thermiting dross into a water puddle and was fatally burned. Casting: Incidents continue to be reported for dc casting arising from bleed-outs

  10. Naturally occurring radionuclides and Earth sciences

    Directory of Open Access Journals (Sweden)

    G. Ferrara

    1997-06-01

    Full Text Available Naturally occurring radionuclides are used in Earth sciences for two fundamental purposes: age determination of rocks and minerals and studies of variation of the isotopic composition of radiogenic nuclides. The methodologies that are in use today allow us to determine ages spanning from the Earth's age to the late Quaternary. The variations of isotopic composition of radiogenic nuclides can be applied to problems of mantle evolution, magma genesis and characterization with respect to different geodynamic situations and can provide valuable information not obtainable by elemental geochemistry.

  11. Pilomyxoid Astrocytoma Occurring in the Third Ventricle

    Directory of Open Access Journals (Sweden)

    Sanghyeon Kim

    2015-01-01

    Full Text Available Pilomyxoid astrocytoma (PMA is a rare central nervous system tumor that has been included in the 2007 World Health Organization Classification of Tumors of the Central Nervous System. Due to its more aggressive behavior, PMA is classified as Grade II neoplasm by the World Health Organization. PMA predominantly affects the hypothalamic/chiasmatic region and occurs in children (mean age of occurrence = 10 months. We report a case of a 24-year-old man who presented with headache, nausea, and vomiting. Brain CT and MRI revealed a mass occupying only the third ventricle. We performed partial resection. Histological findings, including monophasic growth with a myxoid background, and absence of Rosenthal fibers or eosinophilic granular bodies, as well as the strong positivity for glial fibrillary acidic protein were consistent with PMA.

  12. Detection of Harmonic Occurring using Kalman Filtering

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar; Shoro, Ghulam Mustafa; Imran, Raja Muhammed

    2014-01-01

    As long as the load to a power system is linear which has been the case before 80's, typically no harmonics are produced. However, the modern power electronic equipment for controlled power consumption produces harmonic disturbances, these devices/equipment possess nonlinear voltage/current chara...... using Kalman filter. This may be very useful for example to quickly switching on certain filters based on the harmonic present. We are using a unique technique to detect the occurrence of harmonics......./current characteristic. These harmonics are not to be allowed to grow beyond a certain limit to avoid any grave consequence to the customer’s main supply. Filters can be implemented at the power source or utility location to eliminate these harmonics. In this paper we detect the instance at which these harmonics occur...

  13. Autoionization of water: does it really occur?

    CERN Document Server

    Artemov, V G; Sysoev, N N; Volkov, A A

    2015-01-01

    The ionization constant of water Kw is currently determined on the proton conductivity sigma1 which is measured at frequencies lower than 10^7 Hz. Here, we develop the idea that the high frequency conductivity sigma2 (~10^11 Hz), rather than sigma1 represents a net proton dynamics in water, to evaluate the actual concentration c of H3O+ and OH- ions from sigma2. We find c to be not dependent on temperature to conclude that i) water electrodynamics is due to a proton exchange between H3O+ (or OH-) ions and neutral H2O molecules rather than spontaneous ionization of H2O molecules, ii) the common Kw (or pH) reflects the thermoactivation of the H3O+ and OH- ions from the potential of their interaction, iii) the lifetime of a target water molecule does not exceed parts of nanosecond.

  14. Introduction to naturally occurring radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.

    1997-08-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose

  15. Introduction to naturally occurring radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Egidi, P.

    1997-08-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose

  16. Analyzing effects of naturally occurring missense mutations.

    Science.gov (United States)

    Zhang, Zhe; Miteva, Maria A; Wang, Lin; Alexov, Emil

    2012-01-01

    Single-point mutation in genome, for example, single-nucleotide polymorphism (SNP) or rare genetic mutation, is the change of a single nucleotide for another in the genome sequence. Some of them will produce an amino acid substitution in the corresponding protein sequence (missense mutations); others will not. This paper focuses on genetic mutations resulting in a change in the amino acid sequence of the corresponding protein and how to assess their effects on protein wild-type characteristics. The existing methods and approaches for predicting the effects of mutation on protein stability, structure, and dynamics are outlined and discussed with respect to their underlying principles. Available resources, either as stand-alone applications or webservers, are pointed out as well. It is emphasized that understanding the molecular mechanisms behind these effects due to these missense mutations is of critical importance for detecting disease-causing mutations. The paper provides several examples of the application of 3D structure-based methods to model the effects of protein stability and protein-protein interactions caused by missense mutations as well.

  17. Chalcogen-height dependent magnetic interactions and magnetic order switching in FeSexTe1-x.

    Science.gov (United States)

    Moon, Chang-Youn; Choi, Hyoung Joon

    2010-02-05

    Magnetic properties of iron chalcogenide superconducting materials are investigated using density-functional calculations. We find that the stability of magnetic phases is very sensitive to the height of chalcogen species from the Fe plane: while FeTe with optimized Te height has the double-stripe (pi, 0) magnetic ordering, the single-stripe (pi, pi) ordering becomes the ground state when Te is lowered below a critical height by, e.g., Se doping. This behavior is understood by opposite Te-height dependences of the superexchange interaction and a longer range magnetic interaction mediated by itinerant electrons. We also demonstrate a linear temperature dependence of the macroscopic magnetic susceptibility in the single-stripe phase in contrast with the constant behavior in the double-stripe phase. Our findings provide a comprehensive and unified view on the magnetism in FeSexTe1-x and iron pnictide superconductors.

  18. Information Needs While A Disaster Is Occurring

    Science.gov (United States)

    Perry, S. C.

    2010-12-01

    that rainfall intensity at their homes might be less than the intensity up in the mountains where the debris flows would start. Nor did they know that debris flows travel too quickly to be outrun. These and many other examples indicate need for social and natural scientists to increase awareness of what to expect when the disaster strikes. This information must be solidly understood before the event occurs - while a disaster is unfolding there are no teachable moments. Case studies indicate that even those who come into a disaster well educated about the phenomenon can struggle to apply what they know when the real situation is at hand. In addition, psychological studies confirm diminished ability to comprehend information at times of stress.

  19. Strong and anisotropic superexchange in the single-molecule magnet (SMM) [MnIII(6)OsIII]3+: promoting SMM behavior through 3d-5d transition metal substitution.

    Science.gov (United States)

    Hoeke, Veronika; Stammler, Anja; Bögge, Hartmut; Schnack, Jürgen; Glaser, Thorsten

    2014-01-06

    The reaction of the in situ generated trinuclear triplesalen complex [(talent-Bu2)MnIII3(solv)n]3+ with (Ph4P)3[OsIII(CN)6] and NaClO4·H2O affords [MnIII6OsIII](ClO4)3 (= [{(talent-Bu2)MnIII3}2{OsIII(CN)6}](ClO4)3) in the presence of the oxidizing agent [(tacn)2NiIII](ClO4)3 (tacn =1,4,7-triazacyclononane), while the reaction of [(talent-Bu2)MnIII3(solv)n]3+ with K4[OsII(CN)6] and NaClO4·H2O yields [MnIII6OsII](ClO4)2 under an argon atmosphere. The molecular structure of [MnIII6OsIII]3+ as determined by single-crystal X-ray diffraction is closely related to the already published [MnIII6Mc]3+ complexes (Mc = CrIII, FeIII, CoIII, MnIII). The half-wave potential of the OsIII/OsII couple is E1/2 = 0.07 V vs Fc+/Fc. The FT-IR and electronic absorption spectra of [MnIII6OsII]2+ and [MnIII6OsIII]3+ exhibit distinct features of dicationic and tricationic [MnIII6Mc]n+ complexes, respectively. The dc magnetic data (μeff vs T, M vs B, and VTVH) of [MnIII6OsII]2+ are successfully simulated by a full-matrix diagonalization of a spin-Hamiltonian including isotropic exchange, zero-field splitting with full consideration of the relative orientation of the D-tensors, and Zeeman interaction, indicating antiferromagnetic MnIII–MnIII interactions within the trinuclear triplesalen subunits (JMn–Mn(1) = −(0.53 ± 0.01) cm–1, Ĥex = −2∑iSMM [MnIII6OsIII]3+ compared to the 3d analogue [MnIII6FeIII]3+ due to the stronger and anisotropic Mc–MnIII exchange interaction.

  20. Manipulating the ferromagnetism in narrow-bandwidth Pr{sub 1-x}Ca{sub x}MnO{sub 3} (0 ≤ x ≤ 0.6) by means of the Mn-Ru t{sub 2g} ferromagnetic super-exchanges

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. L.; Liu, M. F.; Xie, Y. L.; Yan, Z. B. [Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Dong, S. [Department of Physics, Southeast University, Nanjing 211189 (China); Liu, J.-M. [Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Institute for Advanced Materials and Laboratory of Quantum Engineering and Materials, South China Normal University, Guangzhou 510006 (China)

    2015-09-28

    The concurrent ferromagnetic and metal-insulator transitions via the double-exchange route and electronic phase separation scenario represent the core ingredients of the physics of manganites. In this work, a Ca{sup 2+} and Ru{sup 4+} co-substitution of Pr{sup 3+} and Mn{sup 3+} in narrow-bandwidth and insulating PrMnO{sub 3}, namely, Pr{sub 1-x}Ca{sub x}Mn{sub 1-x}Ru{sub x}O{sub 3} (PCMRO, x ≤ 0.6), is carried out in order to investigate an alternative approach to effectively manipulate the ferromagnetism of PrMnO{sub 3}-based manganites. It is revealed that PCMRO over the whole substitution range is homogeneous solid solution with increased lattice distortion. The preference of Ru{sup 4+} valence state and the absence of Mn{sup 4+} valence state disable the Mn{sup 3+}-Mn{sup 4+} e{sub g}-orbital double-exchange, and the random occupation of Ru{sup 4+} in the lattice excludes the charge ordering and electronic phase separation. While all these consequences should favor antiferromagnetic insulating states, nevertheless, a high-temperature ferromagnetic transition is triggered by the co-substitution and the magnetization can reach up to ∼1.0 μ{sub B}/f.u. at x ∼ 0.2–0.3, much bigger than the moment (<0.1 μ{sub B}/f.u.) of Pr{sub 1−x}Ca{sub x}MnO{sub 3} in the weak ferromagnetic insulator state. It is suggested that this strong ferromagnetism is substantially ascribed to the Mn{sup 3+}-Ru{sup 4+} t{sub 2g}-orbital ferromagnetic super-exchange, and a simple geometric network illustration of the magnetism and electrical transport is presented.

  1. A comparison of substorms occurring during magnetic storms with those occurring during quiet times

    Science.gov (United States)

    McPherron, R. L.; Hsu, T.-S.

    2002-09-01

    It has been suggested that there may be a fundamental difference between substorms that occur during magnetic storms and those that occur at other times. [1996] presented evidence that there is no obvious change in lobe field in "quiet time" substorms but that "storm time" substorms exhibit the classic pattern of storage and release of lobe field energy. This result led them to speculate that the former are caused by current sheet disruption, while the latter are caused by reconnection of lobe flux. In this paper we examine their hypothesis with a much larger data set using definitions of the two types of substorms similar to theirs, as well as additional more restrictive definitions of these classes of events. Our results show that the only differences between the various classes are the absolute value of the lobe field and the size of the changes. When the data are normalized to unit field amplitude, we find that the percent change during storm time and non-storm time substorms is nearly the same. The above conclusions are demonstrated with superposed epoch analysis of lobe field (Bt and Bz) for four classes of substorms: active times (Dst -25 nT), and quiet time substorms (no evidence of storm in Dst). Epoch zero for the analysis was taken as the main substorm onset (Pi2 onset closest to sharp break in AL index). Our results suggest that there is no qualitative distinction between the various classes of substorms, and so they are all likely to be caused by the same mechanism.

  2. Tuning magnetic exchange interactions in crystalline thin films of substituted Cobalt Phthalocyanine

    Science.gov (United States)

    Rawat, Naveen; Manning, Lane; Hua, Kim-Ngan; Headrick, Randall; Bishop, Michael; McGill, Stephen; Waterman, Rory; Furis, Madalina

    Magnetic exchange interactions in diluted organometallic crystalline thin film alloys of Phthalocyanines (Pcs) made of a organo-soluble derivatives of Cobalt Pc and metal-free (H2Pc) molecule and is investigated. To this end, we synthesized a organosoluble CoPc and successfully employed a novel solution-based pen-writing deposition technique to fabricate long range ordered thin films of mixtures of different ratios ranging from 1:1 to 10:1 H2Pc:CoPc. Our previous magnetic circular dichroism (MCD) results on the parent CoPc crystalline thin films identified different electronic states mediating exchange interactions and indirect exchange interaction competing with superexchange interaction. This understanding of spin-dependent exchange interaction between delocalized π-electrons with unpaired d spins along with the excitonic delocalization character enabled the further tuning of these interactions by essentially varying the spatial distance between the spins. Furthermore, high magnetic field (B CAREER and EPM program Awards: DMR-0722451, DMR-0821268, DMR-1307017 and DMR-1056589, DMR-1229217.

  3. Discovering Psychological Principles by Mining Naturally Occurring Data Sets.

    Science.gov (United States)

    Goldstone, Robert L; Lupyan, Gary

    2016-07-01

    The very expertise with which psychologists wield their tools for achieving laboratory control may have had the unwelcome effect of blinding psychologists to the possibilities of discovering principles of behavior without conducting experiments. When creatively interrogated, a diverse range of large, real-world data sets provides powerful diagnostic tools for revealing principles of human judgment, perception, categorization, decision-making, language use, inference, problem solving, and representation. Examples of these data sets include patterns of website links, dictionaries, logs of group interactions, collections of images and image tags, text corpora, history of financial transactions, trends in twitter tag usage and propagation, patents, consumer product sales, performance in high-stakes sporting events, dialect maps, and scientific citations. The goal of this issue is to present some exemplary case studies of mining naturally existing data sets to reveal important principles and phenomena in cognitive science, and to discuss some of the underlying issues involved with conducting traditional experiments, analyses of naturally occurring data, computational modeling, and the synthesis of all three methods.

  4. Influence of Clays on Borehole Stability : a Literature Survey Part One: Occurence of Drilling Problems. Physico-Chemical Description of Clays and of Their Interaction with Fluids Influence des argiles sur la stabilité des parois de puits : revue bibliographique. Première partie : les problèmes rencontrés lors du forage dans les argiles. Description physico-chimique des argiles et de leur interaction avec les fluides

    Directory of Open Access Journals (Sweden)

    Forsans T.

    2006-11-01

    Full Text Available This survey of literature was undertaken by ARTEP- the French Research Association for Oil Exploration and Production Techniques- at the beginning of STAR (=STabilité des ARgiles, a project on the influence of clays on borehole stability. Knowledge of theories and laboratory experiments was indeed felt very necessary to help understanding, and thus becoming able to prevent, quite damaging phenomena. During the time spent on this project, ideas and interpretations of all participants underwent some evolution due to the comparison between theories and experiment, and new procedures and interpretations are being proposed elsewhere. The survey is divided in four sections :The first section recalls the specific problems caused by the occurrence of shales during drilling operations for oil or gas : about 90 % of the problems, for about 70% of the drilled formations. The behaviour of the shales leads to a classification in four different classes : dispersive, swelling, heaving and brittle. They are spread all over the world, not only on the Gulf Coast of the USA and in the North Sea, where they have been more extensively studied, but also in former USSR, in Asia and Africa. Due to deposit conditions and diagenetic history, they occur at different depths, with different properties : reactive shales, at shallow depths, under-, over- or normally-compacted formations, and reservoir caps. Besides their mineralogical and textural properties, due to the large proportion of clays, they have damaging properties as the low permeability (10 to the power of (-6 to 10 to the power of (-12 D. The variety of reactions with water extends from a complete dispersion in mud to cavings or swelling of the borehole, with cuttings ranging from less than 1 mm to more than several cm. This has led to use of various empirical solutions to protect the borehole, with mainly mechanical or chemical objectives. However, it is felt that the general solutions can arise only from a

  5. Increasing the Curie temperature of Ca{sub 2}FeMoO{sub 6} double perovskite by introducing near-neighbour antiferromagnetic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Rubi, D [Institut de Ciencia de Materials de Barcelona, CSIC, Campus UAB, 08193, Bellaterra (Spain); Frontera, C [Institut de Ciencia de Materials de Barcelona, CSIC, Campus UAB, 08193, Bellaterra (Spain); Roig, A [Institut de Ciencia de Materials de Barcelona, CSIC, Campus UAB, 08193, Bellaterra (Spain); Nogues, J [Institut Catala de Recerca i Estudis Avancats (ICREA), 08193, Bellaterra, Catalunya (Spain); Munoz, J S [Departament de Fisica, Universitat Autonoma de Barcelona, 08193, Bellaterra, Catalunya (Spain); Fontcuberta, J [Institut de Ciencia de Materials de Barcelona, CSIC, Campus UAB, 08193, Bellaterra (Spain)

    2005-12-21

    We report on the magnetic, magnetotransport and structural characterization of (Ca{sub 1-y}Nd{sub y}){sub 2}Fe{sub 1+x}Mo{sub 1-x}O{sub 6} (x<0.5) ferromagnetic double perovskites. It is found that the presence of an excess (x>0) of Fe ions in the metallic sublattice produces a remarkable increase, by more than 90 K, of the Curie temperature. Moessbauer spectroscopy data indicate a reinforcement of the magnetic interactions. We argue that this dramatic enhancement of the ferromagnetic order is due to the strong antiferromagnetic superexchange coupling between near-neighbour Fe-Fe occupying regular and antisite positions in the structure. Moreover, the results indicate that the excess of magnetic ions (Fe) is essential to overcome the dilution effects caused by antisite defects.

  6. Gas Surface Interactions Occurring on Materials Within Ultrahigh Vacuum. Ph.D. Thesis - va. Polytechnic Inst.

    Science.gov (United States)

    Outlaw, R. A.

    1972-01-01

    The physical adsorption of nitrogen on the chemically cleaned surfaces of Pyrex, 347 stainless steel and polycrystalline nickel was investigated over the pressure range 1 x 10 to the minus 12th power to 3 x 10 to the minus 7th power torr and for temperatures 77.4 and 87.4 K. The adsorption data were linearized by the Dubinin-Radushkevich equation. The metal surfaces were cleaned by electron impact desorption (EID) and the desorbed gases analyzed by mass spectrometry. Work function measurements were also used to indicate changes in the surface condition following an EID dose. At least a monolayer of gas was observed to desorb from the metal surfaces. The isotherms revealed that the metal surfaces were very heterogeneous and that the Pyrex surface had been leached. The calculated isosteric heats of adsorption indicated that the relative order of the physical binding of nitrogen to the solids was 347 stainless steel Pyrex nickel. A relationship was observed to exist in the dynamic technique between the equilibration time and the pressure above the absorbed layer. The slope of the log-log plot of these parameters was found to be sensitive to the surface heterogeneity and may be related to the activation energy for surface diffusion of physically absorbed molecules.

  7. Microbial interactions with naturally occurring hydrophobic sediments: Influence on sediment and associated contaminant mobility.

    Science.gov (United States)

    Droppo, I G; Krishnappan, B G; Lawrence, J R

    2016-04-01

    The erosion, transport and fate of sediments and associated contaminants are known to be influenced by both particle characteristics and the flow dynamics imparted onto the sediment. The influential role of bitumen containing hydrophobic sediments and the microbial community on sediment dynamics are however less understood. This study links an experimental evaluation of sediment erosion with measured sediment-associated contaminant concentrations and microbial community analysis to provide an estimate of the potential for sediment to control the erosion, transport and fate of contaminants. Specifically the paper addresses the unique behaviour of hydrophobic sediments and the role that the microbial community associated with hydrophobic sediment may play in the transport of contaminated sediment. Results demonstrate that the hydrophobic cohesive sediment demonstrates unique transport and particle characteristics (poor settling and small floc size). Biofilms were observed to increase with consolidation/biostabilization times and generated a unique microbial consortium relative to the eroded flocs. Natural oil associated with the flocs appeared to be preferentially associated with microbial derived extracellular polymeric substances. While PAHs and naphthenic acid increased with increasing shear (indicative of increasing loads), they tended to decrease with consolidation/biostabilization (CB) time at similar shears suggesting a chemical and/or biological degradation. PAH and napthenic acid degrading microbes decreased with time as well, which may suggest that there was a reduced pool of PAHs and naphthenic acids available resulting in their die off. This study emphasizes the importance that any management strategies and operational assessments for the protection of human and aquatic health incorporate the sediment (suspended and bed sediment) and biological (biofilm) compartments and the energy dynamics within the system in order to better predict contaminant transport.

  8. Antituberculosis Activity of a Naturally Occurring Flavonoid, Isorhamnetin.

    Science.gov (United States)

    Jnawali, Hum Nath; Jeon, Dasom; Jeong, Min-Cheol; Lee, Eunjung; Jin, Bongwhan; Ryoo, Sungweon; Yoo, Jungheon; Jung, In Duk; Lee, Seung Jun; Park, Yeong-Min; Kim, Yangmee

    2016-04-22

    Isorhamnetin (1) is a naturally occurring flavonoid having anticancer and anti-inflammatory properties. The present study demonstrated that 1 had antimycobacterial effects on Mycobacterium tuberculosis H37Rv, multi-drug- and extensively drug-resistant clinical isolates with minimum inhibitory concentrations of 158 and 316 μM, respectively. Mycobacteria mainly affect the lungs, causing an intense local inflammatory response that is critical to the pathogenesis of tuberculosis. We investigated the effects of 1 on interferon (IFN)-γ-stimulated human lung fibroblast MRC-5 cells. Isorhamnetin suppressed the release of tumor necrosis factor (TNF)-α and interleukin (IL)-12. A nontoxic dose of 1 reduced mRNA expression of TNF-α, IL-1β, IL-6, IL-12, and matrix metalloproteinase-1 in IFN-γ-stimulated cells. Isorhamnetin inhibited IFN-γ-mediated stimulation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase and showed high-affinity binding to these kinases (binding constants: 4.46 × 10(6) M(-1) and 7.6 × 10(6) M(-1), respectively). The 4'-hydroxy group and the 3'-methoxy group of the B-ring and the 5-hydroxy group of the A-ring of 1 play key roles in these binding interactions. A mouse in vivo study of lipopolysaccharide-induced lung inflammation revealed that a nontoxic dose of 1 reduced the levels of IL-1β, IL-6, IL-12, and INF-γ in lung tissue. These data provide the first evidence that 1 could be developed as a potent antituberculosis drug.

  9. First-principles investigation of exchange interactions in quasi-one-dimensional antiferromagnet CaV2O4

    Science.gov (United States)

    Pchelkina, Z. V.; Solovyev, I. V.

    2015-01-01

    The effects of orbital degrees of freedom on the exchange interactions in a quasi-one-dimensional spin-1 antiferromagnet CaV2O4 are systematically studied. For this purpose a realistic low-energy electron model with the parameters derived from the first-principles calculations is constructed in the Wannier basis for the t2g bands. The exchange interactions are calculated using both the theory of infinitesimal spin rotations near the mean-field ground state and the superexchange model, which provide a consistent description. The obtained behaviour of exchange interactions differs substantially from the previously proposed phenomenological picture based on magnetic measurements and structural considerations, namely: (i) despite the quasi-one-dimensional character of the crystal structure, consisting of the zigzag chains of the edge-sharing VO6 octahedra, the electronic structure is essentially three-dimensional, that leads to finite interactions between the chains; (ii) the exchange interactions along the legs of the chains appear to dominate; and (iii) there is a substantial difference in exchange interactions in two crystallographically inequivalent chains. The combination of these three factors successfully reproduces the behaviour of experimental magnetic susceptibility.

  10. Naturally Occuring Brands: a New Perspective on Place Marketing

    National Research Council Canada - National Science Library

    Christine Wright-Isak

    2010-01-01

      Naturally Occurring Brands: A New Perspective on Place Marketing We suggest community types are "natural brands," because their differentiated imagery has meaning that influences consumer housing choices...

  11. Angular cheilitis occurring during orthodontic treatment: a case series.

    Science.gov (United States)

    Cross, David L; Short, Laura J

    2008-12-01

    Clinical experience has shown that angular cheilitis can occur during orthodontic treatment and may persist into retention, but the incidence of the condition is unknown. The purpose of this paper is to increase the awareness among clinicians of angular cheilitis occurring during orthodontic treatment. It also proposes a treatment regime which may be used.

  12. Intermolecular interactions between imidazole derivatives intercalated in layered solids. Substituent group effect

    Energy Technology Data Exchange (ETDEWEB)

    González, M.; Lemus-Santana, A.A. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México, DF (Mexico); Rodríguez-Hernández, J. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México, DF (Mexico); Instituto de Ciencia y Tecnología de Materiales, Universidad de La Habana, Havana (Cuba); Aguirre-Velez, C.I. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México, DF (Mexico); Knobel, M. [Institute of Physics “Gleb Wataghin”, UNICAMP, 13083-970 Campinas, SP (Brazil); Reguera, E., E-mail: edilso.reguera@gmail.com [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México, DF (Mexico)

    2013-08-15

    This study sheds light on the intermolecular interactions between imidazole derive molecules (2-methyl-imidazole, 2-ethyl-imidazole and benzimidazole) intercalated in T[Ni(CN){sub 4}] layers to form a solid of formula unit T(ImD){sub 2}[Ni(CN){sub 4}]. These hybrid inorganic–organic solids were prepared by soft chemical routes and their crystal structures solved and refined from X-ray powder diffraction data. The involved imidazole derivative molecules were found coordinated through the pyridinic N atom to the axial positions for the metal T in the T[Ni(CN){sub 4}] layer. In the interlayers region ligand molecules from neighboring layers remain stacked in a face-to-face configuration through dipole–dipole and quadrupole–quadrupole interactions. These intermolecular interactions show a pronounced dependence on the substituent group and are responsible for an ImD-pillaring concatenation of adjacent layers. This is supported by the structural information and the recorded magnetic data in the 2–300 K temperature range. The samples containing Co and Ni are characterized by presence of spin–orbit coupling and pronounced temperature dependence for the effective magnetic moment except for 2-ethyl-imidazole related to the local distortion for the metal coordination environment. For this last one ligand a weak ferromagnetic ordering ascribed to a super-exchange interaction between T metals from neighboring layers through the ligands π–π interaction was detected. - Graphical abstract: In the interlayers region imidazole derivative molecules are oriented according to their dipolar and quadrupolar interactions and minimizing the steric impediment. Highlights: • Imidazole derivatives intercalation compounds. • Intermolecular interaction between intercalated imidazole derivatives. • Hybrid inorganic–organic solids. • Pi–pi interactions and ferromagnetic coupling. • Dipolar and quadrupolar interactions between intercalated imidazole derivatives.

  13. Comparative Toxicology of Libby Amphibole and Naturally Occurring Asbestos

    Science.gov (United States)

    Summary sentence: Comparative toxicology of Libby amphibole (LA) and site-specific naturally occurring asbestos (NOA) provides new insights on physical properties influencing health effects and mechanisms of asbestos-induced inflammation, fibrosis, and tumorigenesis.Introduction/...

  14. Comparative Toxicology of Libby Amphibole and Naturally Occurring Asbestos

    Science.gov (United States)

    Summary sentence: Comparative toxicology of Libby amphibole (LA) and site-specific naturally occurring asbestos (NOA) provides new insights on physical properties influencing health effects and mechanisms of asbestos-induced inflammation, fibrosis, and tumorigenesis.Introduction/...

  15. Spin-orbit coupling and magnetic interactions in Si(111):{C,Si,Sn,Pb}

    Science.gov (United States)

    Badrtdinov, D. I.; Nikolaev, S. A.; Katsnelson, M. I.; Mazurenko, V. V.

    2016-12-01

    We study the magnetic properties of the adatom systems on a semiconductor surface Si(111):{C,Si,Sn,Pb}-(√{3 }×√{3 }) . On the basis of all-electron density functional theory calculations we construct effective low-energy models taking into account spin-orbit coupling and electronic correlations. The Hartree-Fock simulations for the unit cell with nine correlated orbitals put forward insulating ground states with the noncollinear 120∘-Néel (for C, Si, Sn monolayer coverages) and 120∘-row-wise (for Pb adatom) antiferromagnetic orderings. The corresponding spin Hamiltonians with anisotropic exchange interactions are derived by means of the superexchange theory and the calculated Dzyaloshinskii-Moriya interactions in the systems with Sn and Pb adatoms are revealed to be very strong and compatible with the isotropic exchange couplings. To simulate the excited magnetic states we solve the constructed spin models by means of the Monte Carlo method, where at low temperatures and zero magnetic field we observe complex spin spiral patterns in Sn/Si(111) and Pb/Si(111). On this basis the formation of antiferromagnetic skyrmion lattice states at high magnetic fields in the adatom s p electron systems is discussed.

  16. Skin picking disorder with co-occurring body dysmorphic disorder.

    Science.gov (United States)

    Grant, Jon E; Redden, Sarah A; Leppink, Eric W; Odlaug, Brian L

    2015-09-01

    There is clinical overlap between skin picking disorder (SPD) and body dysmorphic disorder (BDD), but little research has examined clinical and cognitive correlates of the two disorders when they co-occur. Of 55 participants with SPD recruited for a neurocognitive study and two pharmacological studies, 16 (29.1%) had co-occurring BDD. SPD participants with and without BDD were compared to each other and to 40 healthy volunteers on measures of symptom severity, social functioning, and cognitive assessments using the Stop-signal task (assessing response impulsivity) and the Intra-dimensional/Extra-dimensional Set Shift task (assessing cognitive flexibility). Individuals with SPD and BDD exhibited significantly worse picking, significantly worse overall psychosocial functioning, and significantly greater dysfunction on aspects of cognitive flexibility. These results indicate that when SPD co-occurs with BDD unique clinical and cognitive aspects of SPD may be more pronounced. Future work should explore possible subgroups in SPD and whether these predict different treatment outcomes.

  17. Endometrial carcinoma occuring from polycystic ovary disease : A case report

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Su Ok; Jeon, Woo Ki [Inje Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-12-01

    Endometrial carcinoma usually occurs in postmenopausal women ; less than 5% occurs in women under the age of 40. Up to one quarter of endometrial carcinoma patients below this age have PCO(polycystic ovary disease, Stein-Leventhal syndrome). The increased incidence of endometrial carcinoma in patients with PCO is related to chronic estrogenic stimulation. We report MR imaging in one case of endometrial carcinoma occuring in a 23 year old woman with PCO and had complained of hypermenorrhea for about three years. On T2-weighted MR image the endometrial cavity was seen to be distended with protruded endometrial masses of intermediate signal intensity, and the junctional zone was disrupted beneath the masses. Both ovaries were best seen on T2-weighted MR imaging and showed multiple small peripheral cysts and low signal-intensity central stroma.

  18. Why Does Bureaucratic Corruption Occur in the EU?

    DEFF Research Database (Denmark)

    Brandt, Urs Steiner; Svendsen, Gert Tinggaard

    2013-01-01

    Why does bureaucratic corruption occur in the EU system? Several examples suggest that bureaucratic corruption exists and that the Commission’s anti-fraud agency, OLAF, is not a fully independent authority. We thus develop a novel interpretation of the principalsupervisor-agent model to cope...... with non-independent anti-fraud units. This model shows that corruption is likely to occur when the expected value to the client from bribing the agent is larger than the expected value to the principal of truth-telling by the supervisor. Overall, this analysis points to the risks of flawed incentives...

  19. Factors affecting the depth of burns occurring in medical institutions.

    Science.gov (United States)

    Cho, Young Soon; Choi, Young Hwan; Yoon, Cheonjae; You, Je Sung

    2015-05-01

    Most cases of burns occurring in medical institutions are associated with activities involving heat. It is very difficult to detect these burns. To date, there are few reports on burns occurring in medical institutions. The purpose of this paper was to analyze the etiology of burns occurring in medical institutions and to elucidate the factors affecting burn depth. We conducted a retrospective analysis of the medical records of patients who visited our center from April 2008 to February 2013. This study enrolled all patients with burns occurring in the medical institution during or related to treatment. We excluded burn patients whose burns were not related to treatment (for example, we excluded patients with scalding burns that occurred in the hospital cafeteria and pediatric patients with hot water burns from the water purifier). However, patients with burns that occurred in the recovery room after general anesthesia were included. A total of 115 patients were enrolled in this study. The average patient age was 41.5 years, with more women than men (M:F=31:84). There were 29 cases (25.3%) of superficial burns (first-degree and superficial second-degree) and 86 cases (74.7%) of deep burns (deep second-degree and third-degree). Hot packs were the most common cause of burns (27 cases, 23.5%), followed by laser therapy, heating pads, and grounding pads, accounting for 15 cases each. There were 89 cases (77.4%) of contact burns and 26 cases (22.6%) of non-contact burns. The most common site of burns was the lower extremities (41 cases, 35.7%). The burn site and contact burns were both factors affecting burn depth. The rate of deep burns was higher in patients with contact burns than in those with non-contact burns (odds ratio 4.26) and was associated with lower body burns (odds ratio 2.85). In burns occurring in medical institutions, there is a high probability of a deep burn if it is a contact burn or occurs in the lower body. Therefore, safety guidelines are needed

  20. Can spontaneous symmetry breaking occur in potential with one minimum?

    CERN Document Server

    Acus, A

    2000-01-01

    Spontaneous symmetry breaking occurs when the symmetry that a physical system possesses, is not preserved for the ground state of the system. Although the procedure of symmetry breaking is quite clear from the mathematical point of view, the physical interpretation of the phenomenon is worth to be better understood. In this note we present a simple and instructive example of the symmetry breaking in a mechanical system. It demonstrates that the spontaneous symmetry breaking can occur for the spatially extended solutions in a potential characterised by a single minimum.

  1. Skin picking disorder with co-occurring body dysmorphic disorder

    DEFF Research Database (Denmark)

    Grant, Jon E; Redden, Sarah A; Leppink, Eric W

    2015-01-01

    There is clinical overlap between skin picking disorder (SPD) and body dysmorphic disorder (BDD), but little research has examined clinical and cognitive correlates of the two disorders when they co-occur. Of 55 participants with SPD recruited for a neurocognitive study and two pharmacological...... studies, 16 (29.1%) had co-occurring BDD. SPD participants with and without BDD were compared to each other and to 40 healthy volunteers on measures of symptom severity, social functioning, and cognitive assessments using the Stop-signal task (assessing response impulsivity) and the Intra...

  2. What is toxicology and how does toxicity occur?

    Science.gov (United States)

    Mückter, Harald

    2003-03-01

    Toxicology has matured since it was defined as the 'science of poisons'. Modern toxicology is no longer anthropocentric but takes on different views at various biological systems, including ecosystems. Each will interact specifically when exposed to defined chemical agents, including drugs. Adverse effects during drug therapy or after (accidental) poisoning are the result of some negative interactions between the agent and the exposed biological system. Toxicity is no longer a specific property of drugs and chemicals but an operative term to describe the adverse outcome of a specific drugs-host interaction. Newer developments in toxicology have focused on the host. Toxicogenetics continues to provide answers to variations of host response to xenobiotics, including drugs. Clinically relevant genetic polymorphisms and gene defects have been detected, and their number is rapidly growing. The key to understanding is in the host proteins that interact with the drug and mediate the cellular response. Hence, the proteom, i.e. the complete set of proteins of a cell, an individual or a species, determines how an exposed biological system may interact with the manifold of different xenobiotics. Structure-activity studies try to find out useful predictive parameters for risk and toxicity assessment.

  3. CLEARANCE OF INDOMETHACIN OCCURS PREDOMINANTLY BY RENAL GLUCURONIDATION

    NARCIS (Netherlands)

    MOOLENAAR, F; CRANCRINUS, S; VISSER, J; DEZEEUW, D; MEIJER, DKF

    1992-01-01

    In this report we describe the conditions of collection, storage and handling of urine samples, collected after oral dosing with indometacin in man, in order to maintain the integrity of the labile glucuronide formed. We found that the body clearance occurs predominantly by renal metabolism, due to

  4. Disseminated Fusariosis Occurring in Two Patients Despite Posaconazole Prophylaxis▿

    OpenAIRE

    Bose, Prithviraj; Parekh, Hiral D.; Holter, Jennifer L.; Greenfield, Ronald A.

    2011-01-01

    Posaconazole is widely used for prophylaxis against invasive fungal infections in patients undergoing myeloablative therapy. Disseminated fusariosis is a serious invasive mold infection in such patients. Preclinical and clinical studies indicate activity of posaconazole against Fusarium. We describe two cases of disseminated fusariosis that occurred despite posaconazole prophylaxis.

  5. Naturally occurring fatty acids: source, chemistry and uses

    Science.gov (United States)

    Natural occurring fatty acids are a large and complex class of compounds found in plants and animals. Fatty acids are abundant and of interest because of their renewability, biodegradability, biocompatibility, low cost, and fascinating chemistry. Of the many fatty acids, only 20-25 of them are widel...

  6. Selective extraction of naturally occurring radioactive Ra2+

    NARCIS (Netherlands)

    van Leeuwen, F.W.B.; Verboom, Willem; Reinhoudt, David

    2005-01-01

    Organic extractants play a significant role in the selective removal of radioactive cations from waste streams. Although, literature on the selective removal of man-made radioactive material such as Americium (Am) is widespread, the selective removal of naturally occurring radioactive material such

  7. Resolving the Diaporthe species occurring on soybean in Croatia

    NARCIS (Netherlands)

    Santos, J.M.; Vrandečić, K.; Ćosić, J.; Duvnjak, T.; Phillips, A.J.L.

    2012-01-01

    Diaporthe (anamorph = Phomopsis) species are plant pathogens and endophytes on a wide range of hosts including economically important crops. At least four Diaporthe taxa occur on soybean and they are responsible for serious diseases and significant yield losses. Although several studies have extensi

  8. Integrative Priming Occurs Rapidly and Uncontrollably during Lexical Processing

    Science.gov (United States)

    Estes, Zachary; Jones, Lara L.

    2009-01-01

    Lexical priming, whereby a prime word facilitates recognition of a related target word (e.g., "nurse" [right arrrow] "doctor"), is typically attributed to association strength, semantic similarity, or compound familiarity. Here, the authors demonstrate a novel type of lexical priming that occurs among unassociated, dissimilar,…

  9. Botteri's Sparrow (Peucaea botterii) Occurs in Northern Coahuila, Mexico

    NARCIS (Netherlands)

    van Els, Paul; Canales-del-Castillo, Ricardo; Klicka, John

    2011-01-01

    Botteri’s Sparrow (Peucaea botterii) occurs widely in the shrub-grasslands of southern North America. We report a breeding population of the species in the Sierra de la Encantada of northern Coahuila, Mexico, ,80 km from the Big Bend area of Texas and .300 km from the nearest previously known breedi

  10. The characteristics of gas hydrates occurring in natural environment

    Science.gov (United States)

    Lu, H.; Moudrakovski, I.; Udachin, K.; Enright, G.; Ratcliffe, C.; Ripmeester, J.

    2009-12-01

    In the past few years, extensive analyses have been carried out for characterizing the natural gas hydrate samples from Cascadia, offshore Vancouver Island; Mallik, Mackenzie Delta; Mount Elbert, Alaska North Slope; Nankai Trough, offshore Japan; Japan Sea and offshore India. With the results obtained, it is possible to give a general picture of the characteristics of gas hydrates occurring in natural environment. Gas hydrate can occur in sediments of various types, from sands to clay, although it is preferentially enriched in sediments of certain types, for example coarse sands and fine volcanic ash. Most of the gas hydrates in sediments are invisible, occurring in the pores of the sediments, while some hydrates are visible, appearing as massive, nodular, planar, vein-like forms and occurring around the seafloor, in the fractures related to fault systems, or any other large spaces available in sediments. Although methane is the main component of most of the natural gas hydrates, C2 to C7 hydrocarbons have been recognized in hydrates, sometimes even in significant amounts. Shallow marine gas hydrates have been found generally to contain minor amounts of hydrogen sulfide. Gas hydrate samples with complex gas compositions have been found to have heterogeneous distributions in composition, which might reflect changes in the composition of the available gas in the surrounding environment. Depending on the gas compositions, the structure type of a natural gas hydrate can be structure I, II or H. For structure I methane hydrate, the large cages are almost fully occupied by methane molecules, while the small cages are only partly occupied. Methane hydrates occurring in different environments have been identified with almost the same crystallographic parameters.

  11. Immunoregulation by naturally occurring and disease-associated autoantibodies

    DEFF Research Database (Denmark)

    Nielsen, Claus H; Bendtzen, Klaus

    2012-01-01

    -receptors on antigen-presenting cells and thereby regulate T-cell activity. Knowledge of the influence of NAbs against cytokines on immune homeostasis is likely to have wide-ranging implications both in understanding pathogenesis and in treatment of many immunoinflammatory disorders, including a number of autoimmune......The role of naturally occurring autoantibodies (NAbs) in homeostasis and in disease manifestations is poorly understood. In the present chapter, we review how NAbs may interfere with the cytokine network and how NAbs, through formation of complement-activating immune complexes with soluble self......-antigens, may promote the uptake and presentation of self-molecules by antigen-presenting cells. Both naturally occurring and disease-associated autoantibodies against a variety of cytokines have been reported, including NAbs against interleukin (IL)-1α, IL-6, IL-8, IL-10, granulocyte-macrophage colony...

  12. Probiotic properties of yeasts occurring in fermented food and beverages

    DEFF Research Database (Denmark)

    Jespersen, Lene

    Besides being able to improve the quality and safety of many fermented food and beverages some yeasts offer a number of probiotic traits. Especially a group of yeast referred to as "Saccharomyces boulardii", though taxonomically belonging to Saccharomyces cerevisiae, has been claimed to have...... probiotic properties. Besides, yeasts naturally occurring globally in food and beverages will have traits that might have a positive impact on human health....

  13. Sensory-motor transformations for speech occur bilaterally.

    Science.gov (United States)

    Cogan, Gregory B; Thesen, Thomas; Carlson, Chad; Doyle, Werner; Devinsky, Orrin; Pesaran, Bijan

    2014-03-01

    Historically, the study of speech processing has emphasized a strong link between auditory perceptual input and motor production output. A kind of 'parity' is essential, as both perception- and production-based representations must form a unified interface to facilitate access to higher-order language processes such as syntax and semantics, believed to be computed in the dominant, typically left hemisphere. Although various theories have been proposed to unite perception and production, the underlying neural mechanisms are unclear. Early models of speech and language processing proposed that perceptual processing occurred in the left posterior superior temporal gyrus (Wernicke's area) and motor production processes occurred in the left inferior frontal gyrus (Broca's area). Sensory activity was proposed to link to production activity through connecting fibre tracts, forming the left lateralized speech sensory-motor system. Although recent evidence indicates that speech perception occurs bilaterally, prevailing models maintain that the speech sensory-motor system is left lateralized and facilitates the transformation from sensory-based auditory representations to motor-based production representations. However, evidence for the lateralized computation of sensory-motor speech transformations is indirect and primarily comes from stroke patients that have speech repetition deficits (conduction aphasia) and studies using covert speech and haemodynamic functional imaging. Whether the speech sensory-motor system is lateralized, like higher-order language processes, or bilateral, like speech perception, is controversial. Here we use direct neural recordings in subjects performing sensory-motor tasks involving overt speech production to show that sensory-motor transformations occur bilaterally. We demonstrate that electrodes over bilateral inferior frontal, inferior parietal, superior temporal, premotor and somatosensory cortices exhibit robust sensory-motor neural

  14. A Stochastical Model for the Earthquake Occurences in Turkey

    Directory of Open Access Journals (Sweden)

    Gamze ÖZEL

    2009-04-01

    Full Text Available The fields of seismology and earthquake engineering deal with the studies for earthquake predictions, hazard assessments and the prevention of possible damage due to destructive earthquakes. Various kind of statistical models are used for the earthquake occurences. The most familiar model is a Poisson process for random series of events. However, the Poisson process is insufficient if the incorporation of more information about the seismic process is required. Recently, a compound Poisson process has been proposed an alternative to the Poisson process for the earthquake analysis. In this study, the compound Poisson process is introduced and the probabilities of earthquake numbers with magnitude M ³ 5.0 which will occur within 3 and 6 months; 5 and 10 years have been obtained for Turkey from the Poisson process. Then, it is shown that the aftershock sequences follow a geometric distribution. By this way, the probabilities of total number of aftershocks which will occur within one year and two years with magnitude M ³ 4.0 in Turkey are obtained from the compound Poisson process. Finally, the expected values of main shocks and total number of aftershocks which will occur within one year and two years are computed. The results show that the earthquake occurrence probability with magnitude M ³ 5.0 increases, whereas the probability of total number of aftershocks with magnitude M ³ 4.0 decreases in Turkey as the time increases. Besides, the total aftershock number with magnitude M ³ 4.0 , after a main shock with magnitude M ³ 5.0, equals to zero with the probability 0.48 within one year. The findings also indicate that approximately 130 main shocks with M ³ 5.0 , 28 aftershocks with magnitude M ³ 4.0 are expected within 30 years in Turkey.

  15. Filtering, control and fault detection with randomly occurring incomplete information

    CERN Document Server

    Dong, Hongli; Gao, Huijun

    2013-01-01

    This book investigates the filtering, control and fault detection problems for several classes of nonlinear systems with randomly occurring incomplete information. It proposes new concepts, including RVNs, ROMDs, ROMTCDs, and ROQEs. The incomplete information under consideration primarily includes missing measurements, time-delays, sensor and actuator saturations, quantization effects and time-varying nonlinearities. The first part of this book focuses on the filtering, control and fault detection problems for several classes of nonlinear stochastic discrete-time systems and

  16. Naturally occurring pentaoxygenated, hexaoxygenated and dimeric xanthones: a literature survey

    Directory of Open Access Journals (Sweden)

    V. Peres

    1997-08-01

    Full Text Available This review gives information on the chemical study of 71 pentaoxygenated, 11 hexaoxygenated and 9 dimeric and more complex xanthones naturally occurring in 7 families, 29 genus and 62 species of higher plants, and 11 described as fern and fungal metabolites. The value of these groups of substances in the connection with the pharmacological activity and the therapeutic use of some species is shown. The structural formulas of 23 isolated compounds and their distribution in the species studied are given.

  17. The effects of naturally occurring impurities in rock salt

    Indian Academy of Sciences (India)

    Alina-Mihaela Badescu; Alexandra Saftoiu

    2014-09-01

    In this paper we investigate the effect that naturally occurring impurities in salt mines have both on effective permittivity of the medium and on radio wave propagation at ∼200 MHz. The effective permittivity is determined based on the dielectric properties of salt and the characteristics of the main impurities. We conclude that at such frequencies the scattering is negligible compared to absorptions. The effect of trapped water in different forms is also evaluated.

  18. Myelodysplastic Syndrome Occurring in a Patient with Gorlin Syndrome.

    Science.gov (United States)

    Mull, Jamie L; Madden, Lisa M; Bayliss, Susan J

    2016-07-01

    We report a case of myelodysplastic syndrome (MDS) occurring in an African American boy with Gorlin syndrome with a novel PTCH1 mutation. Before developing MDS, the patient had been treated with chemotherapy and radiation for a medulloblastoma. He received a bone marrow transplant for the MDS and eventually died of treatment complications. Secondary hematologic malignancies are a known complication of certain chemotherapeutics, although whether a patient with Gorlin syndrome has a greater propensity for the development of such malignancies is unclear.

  19. Hepatocellular carcinoma occurring in a Crohn’s disease patient

    Institute of Scientific and Technical Information of China (English)

    Mitsuaki; Ishida; Shigeyuki; Naka; Hisanori; Shiomi; Tomoyuki; Tsujikawa; Akira; Andoh; Tamio; Nakahara; Yasuharu; Saito; Yoshi-hide; Fujiyama; Mikiko; Takikita-Suzuki; Fumiyoshi; Kojima; Machiko; Hotta; Tohru; Tani; Yoshimasa; Kurumi; Hidetoshi; Okabe

    2010-01-01

    We report a case of hepatocellular carcinoma (HCC) occurring in a patient with Crohn’s disease (CD) without chronic hepatitis or liver cirrhosis, and review the clinicopathological features of HCC in CD patients. A 37-year-old Japanese man with an 8-year history of CD and a medication history of azathioprine underwent resection of a liver tumor. The histopathology of the liver tumor was pseudoglandular type HCC. In the nonneoplastic liver, focal hepatocyte glycogenosis (FHG) was observed, however, there was...

  20. A computational study of magnetic exchange interactions of 3d and 4f electrons in Ti-Ce co-doped AlN

    Energy Technology Data Exchange (ETDEWEB)

    Majid, Abdul, E-mail: abdulmajid40@yahoo.com [Department of Physics, University of Gujrat, Gujrat (Pakistan); Department of Adaptive Machine Systems, Osaka University, Osaka (Japan); Azmat, Mian [Department of Physics, University of Gujrat, Gujrat (Pakistan); Rana, Usman Ali; Khan, Salah Ud-Din [Sustainable Energy Technologies Center, College of Engineering, King Saud University, PO-Box 800, Riyadh 11421 (Saudi Arabia); Alzahrani, Eman [Department of Chemistry, Faculty of Science, Taif University, 888 Taif (Saudi Arabia)

    2016-08-15

    To investigate the nature of 3d-4f exchange interactions in III-Nitride semiconductors, Ti-Ce co-doped AlN were studied using first principles calculations. The calculations were performed using supercell approach with varying dopant concentration and different inter-dopant separation. The configuration with dopant located as nearest neighbor distance and diluted concentration of 3.125% was found most stable. The results exhibited prominent evidence of 3d-4f-5d strong hybridization suggesting 3d-4f direct exchange interactions which may play valuable role to exploit the system as high Curie temperature ferromagnetic semiconductors for use in spintronics. Moreover, metal to metal charge transfer was also observed in the materials which may be exploited for their use in electrochemical applications. The 4f-5d and 3d-5d hybridizations were observed that predicts excellent luminescence phenomena in the materials. The presence of impurity related deep intermediate bands suggest applications of the materials in opto-electronic and spintronics devices. - Highlights: • Double exchange interaction in Ti:AlN. • Impurity induced narrowing of band gap. • Superexchange interaction in Ce:AlN. • 3d-4f exchange interaction between Ti-3d and Ce-4f states. • High Curie temperature n-type ferromagnetic semiconductors.

  1. Naturally Occurring Anthraquinones: Chemistry and Therapeutic Potential in Autoimmune Diabetes

    Directory of Open Access Journals (Sweden)

    Shih-Chang Chien

    2015-01-01

    Full Text Available Anthraquinones are a class of aromatic compounds with a 9,10-dioxoanthracene core. So far, 79 naturally occurring anthraquinones have been identified which include emodin, physcion, cascarin, catenarin, and rhein. A large body of literature has demonstrated that the naturally occurring anthraquinones possess a broad spectrum of bioactivities, such as cathartic, anticancer, anti-inflammatory, antimicrobial, diuretic, vasorelaxing, and phytoestrogen activities, suggesting their possible clinical application in many diseases. Despite the advances that have been made in understanding the chemistry and biology of the anthraquinones in recent years, research into their mechanisms of action and therapeutic potential in autoimmune disorders is still at an early stage. In this paper, we briefly introduce the etiology of autoimmune diabetes, an autoimmune disorder that affects as many as 10 million worldwide, and the role of chemotaxis in autoimmune diabetes. We then outline the chemical structure and biological properties of the naturally occurring anthraquinones and their derivatives with an emphasis on recent findings about their immune regulation. We discuss the structure and activity relationship, mode of action, and therapeutic potential of the anthraquinones in autoimmune diabetes, including a new strategy for the use of the anthraquinones in autoimmune diabetes.

  2. Evolution of virulence when transmission occurs before disease.

    Science.gov (United States)

    Osnas, Erik E; Dobson, Andrew P

    2010-08-23

    Most models of virulence evolution assume that transmission and virulence are constant during an infection. In many viral (HIV and influenza), bacterial (TB) and prion (BSE and CWD) systems, disease-induced mortality occurs long after the host becomes infectious. Therefore, we constructed a model with two infected classes that differ in transmission rate and virulence in order to understand how the evolutionarily stable strategy (ESS) depends on the relative difference in transmission and virulence between classes, on the transition rate between classes and on the recovery rate from the second class. We find that ESS virulence decreases when expressed early in the infection or when transmission occurs late in an infection. When virulence occurred relatively equally in each class and there was disease recovery, ESS virulence increased with increased transition rate. In contrast, ESS virulence first increased and then decreased with transition rate when there was little virulence early in the infection and a rapid recovery rate. This model predicts that ESS virulence is highly dependent on the timing of transmission and pathology after infection; thus, pathogen evolution may either increase or decrease virulence after emergence in a new host.

  3. Percutaneous treatment of complications occurring during hemodialysis graft recanalization

    Energy Technology Data Exchange (ETDEWEB)

    Sofocleous, Constantinos T. E-mail: constant@pol.net; Schur, Israel; Koh, Elsie; Hinrichs, Clay; Cooper, Stanley G.; Welber, Adam; Brountzos, Elias; Kelekis, Dimitris

    2003-09-01

    Introduction/objective: To describe and evaluate percutaneous treatment methods of complications occurring during recanalization of thrombosed hemodialysis access grafts. Methods and materials: A retrospective review of 579 thrombosed hemodialysis access grafts revealed 48 complications occurring during urokinase thrombolysis (512) or mechanical thrombectomy (67). These include 12 venous or venous anastomotic ruptures not controlled by balloon tamponade, eight arterial emboli, 12 graft extravasations, seven small hematomas, four intragraft pseudointimal 'dissections', two incidents of pulmonary edema, one episode of intestinal angina, one procedural death, and one distant hematoma. Results: Twelve cases of post angioplasty ruptures were treated with uncovered stents of which 10 resulted in graft salvage allowing successful hemodialysis. All arterial emboli were retrieved by Fogarty or embolectomy balloons. The 10/12 graft extravasations were successfully treated by digital compression while the procedure was completed and the graft flow was restored. Dissections were treated with prolonged Percutaneous Trasluminal Angioplasty (PTA) balloon inflation. Overall technical success was 39/48 (81%). Kaplan-Meier Primary and secondary patency rates were 72 and 78% at 30, 62 and 73% at 90 and 36 and 67% at 180 days, respectively. Secondary patency rates remained over 50% at 1 year. There were no additional complications caused by these maneuvers. Discussions and conclusion: The majority of complications occurring during percutaneous thrombolysis/thrombectomy of thrombosed access grafts, can be treated at the same sitting allowing completion of the recanalization procedure and usage of the same access for hemodialysis.

  4. Host Active Defense Responses Occur within 24 Hours after Pathogen Inoculation in the Rice Blast System

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-hua; JIA Yu-lin; LIN Hui; Adair INTERN; Barbara VALENT; J. Neil RUTGER

    2007-01-01

    Phenotypical, cytological and molecular responses of rice to the fungus Magnaporthe grisea were studied using rice cultivars and lesion mimic plants. The cultivar Katy was susceptible to several virulent M. grisea isolates, and a Sekiguchi like-lesion mimic mutant of Katy (LmmKaty) showed enhanced resistance to these isolates. Lesion mimic phenotype of LmmKaty was rapidly induced by virulent M. grisea isolates or by avirulent ones only at high levels of inoculum.Autofluorescence (a sign of an active defense response) was visible under ultraviolet light 24 h after localized inoculation in the incompatible interaction, whereas, not evident in the compatible interaction. Autofluorescence was also observed in LmmKaty 20 h after pathogen inoculation, indicating that rapid cell death is a mechanism of LmmKaty to restrict pathogen invasion. Rapid accumulations of defense related (DR) gene transcripts, phenylalanine ammonia lyase and β-glucanase,were observed beginning at 6 h and were obvious at 16 h and 24 h after inoculation in an incompatible interaction. Rapid transcript accumulations of PR-1 and chitinase had occurred by 24 h after inoculation in an incompatible interaction.Accumulations of these transcripts were delayed in the compatible interaction. These results indicate that host active defense responses occur 24 h after pathogen inoculation and that LmmKaty exhibits enhanced resistance to M. grisea. It is suggested that the autofluorescence and expression of the DR genes after heavy inoculation are important cytological and molecular markers respectively for early determination of the host response to M. grisea in the rice blast system.

  5. Naturally occurring Trichogramma species in olive farms in Egypt

    Institute of Scientific and Technical Information of China (English)

    ESMATMOHAMEDHEGAZI; ANNETTEHERZ; SHERIFHASSAN; ESSAMAGAMY; WEDADKHAFAGI; SANIASHWEIL; AHMEDZAITUN; SAFAAMOSTAFA; MOHAMEDHAFEZ; AHMEDEL-SHAZLY; SOMAIAEL-SAID; LAMIAABO-ABDALA; NOHAKHAMIS; SAMIAEL-KEMNY

    2005-01-01

    A survey of two-year studies (2001-2003) was carried out in two olive groves sited at two representative olive growing areas, namely Paradise Park (arid area) and Burg E1-Arab farm (semi-arid area) to monitor the frequency of endemic Trichogramma species on olive moth (Prays oleae) and jasmine moth (Palpita unionalis). The suspended host bait traps were found to be a more practical and effective tool for collecting Trichogramma wasps than the attached ones. Four naturally occurring Trichogramma species were collected for the first time in Egypt from the olive groves, where releases have never been conducted. T.bourarachae was collected exclusively from Burg El-Arab farm. It seems that this wasp species adapts well to the semi-arid area. Three species, namely T. cordubensis, T. nr.pretiosum and T. cacociae were isolated from Paradise Park farm. All of these wasps were also bred from naturally parasitized host eggs during favorable and even at unfavorable temperature conditions of June-August. However, these endemic species did not occur naturally in sufficient numbers to keep the pest populations from reaching damaging levels.The excessive usage of insecticides and the oophagous predators (e.g., ants and lacewing larvae) are some factors that affect the performance of Trichogramma wasps in olive farms.The presence of warm weather wasp strains suggests the existence of well-adapted wasp species or swains which may be appropriate candidates for the control of target pests in olive groves. Additional study is required to determine the best “habitat-specific” species/strains of Trichogramma for augmentative release of naturally occurring wasps and to incorporate them into integrated pest management programs. Efforts should be made to conserve these endemic species from oophagous predators, hot weather and insecticides.The olive and jasmine moth-larvae and pupae found under tree canopies were bred and emerged parasitoids were listed.

  6. Hemostatic abnormalities in dogs with naturally occurring heatstroke.

    Science.gov (United States)

    Bruchim, Yaron; Kelmer, Efrat; Cohen, Adar; Codner, Carolina; Segev, Gilad; Aroch, Itamar

    2017-05-01

    To investigate hemostatic analyte abnormalities and their association with mortality in dogs with naturally occurring heatstroke. Prospective observational study. University teaching hospital. Thirty client-owned dogs with naturally occurring heatstroke. None. Citrated and EDTA blood samples were collected at presentation and at 4, 12, 24, 36, and 48 hours postpresentation (PP). Hemostatic tests performed included platelet count, prothrombin and activated partial thromboplastin times (PT and aPTT, respectively), antithrombin activity (ATA), total protein C activity (tPCA), fibrinogen, and D-dimer concentrations. The overall survival rate was 60% (18/30 dogs). Older age, higher heart rate and rectal temperature at presentation, and time from onset of clinical signs to presentation were significantly associated with mortality. Hemostatic analytes at presentation were not associated with mortality. Prolonged PT and aPTT at 12-24 hours PP, lower tPCA at 12 hours PP, and hypofibrinogenemia at 24 hours PP were significantly (P ATA were common at all time points, but were not associated with mortality. The frequency of disseminated intravascular coagulation (DIC) increased in nonsurvivors throughout hospitalization, but the development of DIC was not associated with mortality. The number of abnormal coagulation disturbances during the first 24 hours was significantly higher in nonsurvivors (P = 0.04). Hemostatic derangements are common in dogs with naturally occurring heatstroke. Alterations in PT, aPTT, tPCA, and fibrinogen concentrations appear to be associated with the outcome at 12-24 hours PP, exemplifying the need for serial measurement of multiple laboratory hemostatic tests during hospitalization, even when within reference interval on presentation. The development of DIC, as defined in this cohort, was not associated with mortality; however, nonsurvivors had significantly more coagulation abnormalities during the first 24 hours PP. © Veterinary Emergency and

  7. Natural transformation of Campylobacter jejuni occurs beyond limits of growth.

    Directory of Open Access Journals (Sweden)

    Christina S Vegge

    Full Text Available Campylobacter jejuni is a human bacterial pathogen. While poultry is considered to be a major source of food borne campylobacteriosis, C. jejuni is frequently found in the external environment, and water is another well-known source of human infections. Natural transformation is considered to be one of the main mechanisms for mediating transfer of genetic material and evolution of the organism. Given the diverse habitats of C. jejuni we set out to examine how environmental conditions and physiological processes affect natural transformation of C. jejuni. We show that the efficiency of transformation is correlated to the growth conditions, but more importantly that transformation occurs at growth-restrictive conditions as well as in the late stationary phase; hence revealing that growth per se is not required for C. jejuni to be competent. Yet, natural transformation of C. jejuni is an energy dependent process, that occurs in the absence of transcription but requires an active translational machinery. Moreover, we show the ATP dependent ClpP protease to be important for transformation, which possibly could be associated with reduced protein glycosylation in the ClpP mutant. In contrast, competence of C. jejuni was neither found to be involved in DNA repair following DNA damage nor to provide a growth benefit. Kinetic studies revealed that several transformation events occur per cell cycle indicating that natural transformation of C. jejuni is a highly efficient process. Thus, our findings suggest that horizontal gene transfer by natural transformation takes place in various habitats occupied by C. jejuni.

  8. Pseudo-Kaposi sarcoma (acroangiodermatitis): occurring after bullous erysipelas.

    Science.gov (United States)

    Kutlubay, Zekayi; Yardimci, Gürkan; Engin, Burhan; Demirkesen, Cuyan; Aydin, Övgü; Khatib, Rashid; Tuzun, Yalçın

    2015-05-18

    Pseudo-Kaposi sarcoma is a benign reactive vascular proliferative disorder, which can be seen at any age. It occurs when the chronic venous pressure changes result in vascular proliferation in the upper and mid dermis. This disease is divided into two subtypes: the most frequent subtype is the Mali type and seen in early ages. The Mali type is seen in chronic venous insufficiency and in those patients with arteriovenous shunts. The rare subtype is the Stewart-Bluefarb type. This disease must be distinguished from Kaposi sarcoma because of their clinical resemblance. Herein, we present a patient with pseudo-Kaposi sarcoma, which developed after bullous erysipelas.

  9. Naturally occurring crystalline phases: analogues for radioactive waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Haaker, R.F.; Ewing, R.C.

    1981-01-01

    Naturally occurring mineral analogues to crystalline phases that are constituents of crystalline radioactive waste forms provide a basis for comparison by which the long-term stability of these phases may be estimated. The crystal structures and the crystal chemistry of the following natural analogues are presented: baddeleyite, hematite, nepheline; pollucite, scheelite;sodalite, spinel, apatite, monazite, uraninite, hollandite-priderite, perovskite, and zirconolite. For each phase in geochemistry, occurrence, alteration and radiation effects are described. A selected bibliography for each phase is included.

  10. A Rare Occurance with Epidermolysis Bullosa Disease: Dilated Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Derya Cimen

    2014-02-01

    Full Text Available Epidermolysis bullosa is a congenital and herediter vesiculobullous disease. Dystrophic form of this disease is characterized by severe malnutrition, failure to thrive, adhesions at fingers, joint contractures related with the formation of scar tissues, carcinoma of the skin, anemia, hipoalbuminemia, wound enfections and sepsis. Rarely, mortal dilated cardiomyopathy may occur in patients. In this report we present a 13 year-old pediatric patient with dilated cardiomyopathy, clinically diagnosed with Epidermolysis bullosa as well as a review of recent related literature.

  11. Structure and magnetic interactions in (Sr, Sb)-doped lanthanum manganites

    Energy Technology Data Exchange (ETDEWEB)

    Karpinsky, D.V., E-mail: karpinsky@physics.by [National Research University of Electronic Technology “MIET”, 124498 Moscow, Zelenograd (Russian Federation); Scientific-Practical Materials Research Centre of NAS of Belarus, 220072 Minsk (Belarus); Troyanchuk, I.O.; Silibin, M.V.; Gavrilov, S.A. [National Research University of Electronic Technology “MIET”, 124498 Moscow, Zelenograd (Russian Federation); Bushinky, M.V. [Scientific-Practical Materials Research Centre of NAS of Belarus, 220072 Minsk (Belarus); Sikolenko, V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Frontzek, M. [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen (Switzerland)

    2016-05-15

    Ceramic samples La{sub 1−2x}Sr{sub 2x}Mn{sub 1−x}Sb{sub x}O{sub 3} (x≤0.2) have been studied by X-ray and neutron powder diffraction, magnetization measurements and charge density calculations have also been performed. The compounds are characterized by the rhombohedral structure at room temperature; temperature decrease causes structural transition to the orthorhombic structure. La{sub 1−2x}Sr{sub 2x}Mn{sub 1−x}Sb{sub x}O{sub 3} ceramics are characterized by homovalent manganese ions and have long range ferromagnetic order which gradually diminishes with the chemical substitution. It is considered that magnetic properties of the compounds are determined by the dominance of ferromagnetic superexchange interactions stabilized in the orbital disordered orthorhombic phase. Significant covalent component of the Mn–O chemical bonds contributes to the long-range ferromagnetic order of the compounds, the covalency of the chemical bonds is assumed to be isotropically distributed over the orthorhombic phase.

  12. Insights into secondary reactions occurring during atmospheric ablation of micrometeoroids

    Science.gov (United States)

    Court, Richard W.; Tan, Jonathan

    2016-06-01

    Ablation of micrometeoroids during atmospheric entry yields volatile gases such as water, carbon dioxide, and sulfur dioxide, capable of altering atmospheric chemistry and hence the climate and habitability of the planetary surface. While laboratory experiments have revealed the yields of these gases during laboratory simulations of ablation, the reactions responsible for the generation of these gases have remained unclear, with a typical assumption being that species simply undergo thermal decomposition without engaging in more complex chemistry. Here, pyrolysis-Fourier transform infrared spectroscopy reveals that mixtures of meteorite-relevant materials undergo secondary reactions during simulated ablation, with organic matter capable of taking part in carbothermic reduction of iron oxides and sulfates, resulting in yields of volatile gases that differ from those predicted by simple thermal decomposition. Sulfates are most susceptible to carbothermic reduction, producing greater yields of sulfur dioxide and carbon dioxide at lower temperatures than would be expected from simple thermal decomposition, even when mixed with meteoritically relevant abundances of low-reactivity Type IV kerogen. Iron oxides were less susceptible, with elevated yields of water, carbon dioxide, and carbon monoxide only occurring when mixed with high abundances of more reactive Type III kerogen. We use these insights to reinterpret previous ablation simulation experiments and to predict the reactions capable of occurring during ablation of carbonaceous micrometeoroids in atmospheres of different compositions.

  13. On the Mechanical Friction Losses Occurring in Automotive Differential Gearboxes

    Directory of Open Access Journals (Sweden)

    Grégory Antoni

    2014-01-01

    Full Text Available In the automobile industry, the mechanical losses resulting from friction are largely responsible for various kinds of surface damage, such as the scuffing occurring in some mechanical assemblies. These scuffing processes seem to be due to a local loss of lubrication between certain mechanical elements of the same assembly, leading to a sharp increase in the friction, which can lead to a surface and volume damage in some of them, and even can cause, in the worst case, the whole destruction of the mechanical system if it has continued to operate. Predicting and checking the occurrence of this kind of undesirable phenomena, especially in some principal systems of the vehicle, represents nowadays, a crucial challenge in terms of automobile reliability and safety. This study focuses on the mechanical friction losses liable to occur in differential automobile gearboxes, which can lead in the long term to the scuffing of these mechanical systems. The friction losses involved were modeled, using a simple analytical approach, which is presented and discussed.

  14. A naturally-occurring 'cold earth' spot in Northern China.

    Science.gov (United States)

    Niu, Fujun; Cheng, Guodong; Niu, Yonghong; Zhang, Mingyi; Luo, Jing; Lin, Zhanju

    2016-09-29

    Permafrost is determined to a large extent by the Earth's surface temperature, therefore it distributes mainly in high altitude and latitude regions. However, stable, warm (about -1 °C) permafrost occurs within a scree slope in northern China that is more than 600 km south of the southernmost limit of latitudinal permafrost on the Eurasian Continent. It is at an elevation of only 900 m above sea level (ASL). The area has a mean annual air temperature (MAAT) of 6 to 8 °C. Thermal processes of the scree slope, investigated through field monitoring and numerical simulation, showed that the permafrost is caused by winter air convection within the porous rock deposits and is stable as air convection does not occur in summer time. The deposit is covered by a 30-cm-thick peaty soil layer dated (carbon C-14) to between 1,000 to 1,600 years ago. The layer also contributes to the permafrost's existence due to the peat's thermal conductivity offset when frozen and thawed. The existence of permafrost under such warm climatic conditions confirms the effectiveness of using crushed rock layer as basement or slope cover to protect the warm permafrost subgrade of the recently-constructed Qinghai-Tibet Railway (QTR), even under the predicted climate warming conditions.

  15. Multifaceted ability of naturally occurring polyphenols against metastatic cancer.

    Science.gov (United States)

    Zhou, Qingyu; Bennett, Lunawati L; Zhou, Shufeng

    2016-04-01

    Although cancer metastases are known to be the main cause of cancer-related deaths, truly effective antimetastatic therapeutics remain scarce in clinical practice. Naturally occurring polyphenols are the most abundant antioxidants in human diets. Many of them possess chemopreventive and chemotherapeutic properties against various types of cancer. Recent advances in understanding the molecular pathways that mediate cancer development and progression have led to an increase of interest in preclinical investigations on the mechanisms underlying anticancer activity of polyphenols. In particular, an increasing number of preclinical studies using cultured cells and animal models have demonstrated the inhibitory effects of polyphenols on tumour cell invasion and metastasis, thereby highlighting the potential of polyphenols against metastatic cancer. This review specifically addresses growing evidence of the capability of polyphenols to impair the invasion and migration of tumour cells through a diverse set of mechanisms, including downregulation of expression of matrix metalloproteinases, modulation of regulators of epithelial-mesenchymal transition, interference with Met signalling, inhibition of nuclear factor-kappa B mediated transcription, and so on. Given that metastasis occurs through a multistep process in which each step is regulated by a complex network of signalling pathways, the multi-function and multi-target characteristics of polyphenols render those promising candidates for effective adjuvant therapy against metastatic cancer.

  16. Economic losses occurring due to brucellosis in Indian livestock populations.

    Science.gov (United States)

    Singh, B B; Dhand, N K; Gill, J P S

    2015-05-01

    Brucellosis is a serious public health issue in India. Estimation of economic losses occurring due to brucellosis is required to help formulate prevention and control strategies, but has not been done in India. We estimated economic losses due to brucellosis by sourcing prevalence data from epidemiological surveys conducted in India. Data for livestock populations were obtained from official records. Probability distributions were used for many of the input parameters to account for uncertainty and variability. The analysis revealed that brucellosis in livestock is responsible for a median loss of US $ 3.4 billion (5th-95th percentile 2.8-4.2 billion). The disease in cattle and buffalo accounted for 95.6% of the total losses occurring due to brucellosis in livestock populations. The disease is responsible for a loss of US $ 6.8 per cattle, US$18.2 per buffalo, US $ 0.7 per sheep, US $ 0.5 per goat and US $ 0.6 per pig. These losses are additional to the economic and social consequences of the disease in humans. The results suggest that the disease causes significant economic losses in the country and should be controlled on a priority basis.

  17. Genetic and molecular dissection of naturally occurring variations in rice

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Masahiro [National Institute of Agrobiological Sciences, Tsukuba, Ibaraki (Japan)

    2002-02-01

    The progress for structural analysis of the rice genome has allowed us to embark on the sequencing of the whole rice genome. Resources - genetic markers, sequence data, and genomic clones - derived from many efforts will be used for the functional analysis of rice genes in the next decade. Although artificially induced variations, such as mutants, have been used mainly for genetic and physiological studies in rice and other plant species, the development of DNA markers has made possible access to naturally occurring allelic variations underlying complex traits. Such analysis is often referred to as quantitative traits locus (QTL) analysis. Many QTLs have been mapped for many complex traits in rice. During the analyses of several quantitative traits by the DNA marker-assisted strategy, two questions about QTL analysis have been raised: 1) Does a QTL represent a single Mendelian locus or a cluster of multiple loci? 2) Is it possible to precisely map a QTL and identify QTLs at the molecular level using map-based or other strategies? To answer these questions, a series of analyses on heading date, including the identification of putative QTLs, characterization and fine mapping of QTLs using nearly isogenic lines (NILs), and identification of genes at QTLs for heading date by the map-based strategy has been performed. In addition, several primary permanent mapping populations and secondary genetic resources, such as chromosomal segmental substitution lines, have been developed to facilitate the genetic analysis of naturally occurring allelic variation. (M. Suetake)

  18. Ingestion analgesia occurs when a bad taste turns good.

    Science.gov (United States)

    Foo, Hayley; Mason, Peggy

    2011-12-01

    During ingestion of water, chocolate, sucrose, and saccharin, pain-related behaviors are suppressed. This ingestion analgesic effect is reversed when the hedonic valence of a food is switched from "good" to "bad" as occurs during conditioned taste aversion. Here, we tested the converse hedonic shift to determine if ingestion analgesia occurs when 0.3 M NaCl is made palatable by inducing a sodium appetite. In Experiment 1, sham- and sodium-depleted rats were tested for paw withdrawal and lick latencies to brief noxious heat during quiet wake and intraoral NaCl ingestion. Only sodium-depleted rats showed a suppression of heat-evoked reactions during NaCl ingestion. In Experiment 2, we tested whether this analgesic effect is mediated by the brainstem nucleus raphe magnus (NRM). Inactivation of NRM with muscimol blocked ingestion analgesia during NaCl ingestion by sodium-depleted rats. This attenuation was not due to a hyperalgesic effect of NRM inactivation. Muscimol microinjections into a nearby region, the nucleus raphe obscurus (NRO), were ineffective. The present findings demonstrate that the internal milieu of an animal can modify ingestion analgesia, and that the analgesia during NaCl ingestion by sodium hungry rats is mediated by NRM. PsycINFO Database Record (c) 2011 APA, all rights reserved.

  19. Regulation of naturally occurring radioactive materials in Australia.

    Science.gov (United States)

    Jeffries, Cameron; Akber, Riaz; Johnston, Andrew; Cassels, Brad

    2011-07-01

    In order to promote uniformity between jurisdictions, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has developed the National Directory for Radiation Protection, which is a regulatory framework that all Australian governments have agreed to adopt. There is a large and diverse range of industries involved in mining or mineral processing, and the production of fossil fuels in Australia. Enhanced levels of naturally occurring radionuclides can be associated with mineral extraction and processing, other industries (e.g. metal recycling) and some products (e.g. plasterboard). ARPANSA, in conjunction with industry and State regulators, has undertaken a review and assessment of naturally occurring radioactive material (NORM) management in Australian industries. This review has resulted in guidance on the management of NORM that will be included in the National Directory for Radiation Protection. The first NORM safety guide provides the framework for NORM management and addresses specific NORM issues in oil and gas production, bauxite, aluminium and phosphate industries. Over time further guidance material for other NORM-related industries will be developed. This presentation will provide an overview of the regulatory approach to managing NORM industries in Australia.

  20. Cutaneous Tuberculosis Occurring After a Skin Cut in a Child.

    Science.gov (United States)

    Akkoc, Gulsen; Kepenekli Kadayifci, Eda; Karaaslan, Ayse; Atici, Serkan; Yakut, Nurhayat; Ocal Demir, Sevilya; Akbas, Gamze; Zeliha Cinel, Leyla; Soysal, Ahmet; Bakir, Mustafa

    2016-08-01

    Tuberculosis is a common problem in Turkey, and cutaneous tuberculosis is a rare form of extrapulmonary tuberculosis. Herein, the authors describe a case of cutaneous tuberculosis (lupus vulgaris) occurring after contact with a sheep. A 15-year-old boy was admitted to Marmara University School of Medicine Pendik Training and Research Hospital (Istanbul, Turkey) with delayed wound healing on the left index finger and left axillary lymphadenopathy. His medical history was unremarkable except for a wound incurred when he slaughtered a sheep 3 months before. One month after this injury, the patient developed enlargement of the left axillary lymph node on the side of the wounded extremity, and the wound turned a dark black color. The biopsy specimens obtained from the wounded skin and lymph nodes showed granulomatous reaction, but acid-fast bacilli (AFB) could not be shown with Ehrlich-Ziehl Neelsen staining. The patient tested positive in an interferon-gamma release assay. Computerized tomography scans of the thorax were normal, and early morning gastric lavage specimen was negative for AFB. The wound and axillary lymphadenopathy disappeared after institution of anti-tuberculosis therapy. Tuberculosis infection must be considered in chronic skin lesions with granulomatous reaction occurring in countries with high prevalence of tuberculosis.

  1. Layered vanadyl (IV) nitroprusside: Magnetic interaction through a network of hydrogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Gil, D.M. [Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN San Miguel de Tucumán (Argentina); Osiry, H. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México (Mexico); Pomiro, F.; Varetti, E.L. [CEQUINOR (CONICET-UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 and 115, 1900, La Plata (Argentina); Carbonio, R.E. [INFIQC – CONICET, Departamento de Físico Química, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre esq, Medina Allende, Ciudad Universitaria, X5000HUA Córdoba (Argentina); Alejandro, R.R. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, México (Mexico); Ben Altabef, A. [INQUINOA-UNT-CONICET, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN San Miguel de Tucumán (Argentina); and others

    2016-07-15

    The hydrogen bond and π-π stacking are two non-covalent interactions able to support cooperative magnetic ordering between paramagnetic centers. This contribution reports the crystal structure and related magnetic properties for VO[Fe(CN){sub 5}NO]·2H{sub 2}O, which has a layered structure. This solid crystallizes with an orthorhombic unit cell, in the Pna2{sub 1} space group, with cell parameters a=14.1804(2), b=10.4935(1), c=7.1722(8) Å and four molecules per unit cell (Z=4). Its crystal structure was solved and refined from powder X-ray diffraction data. Neighboring layers remain linked through a network of hydrogen bonds involving a water molecule coordinated to the axial position for the V atom and the unbridged axial NO and CN ligands. An uncoordinated water molecule is found forming a triple bridge between these last two ligands and the coordinated water molecule. The magnetic measurements, recorded down to 2 K, shows a ferromagnetic interaction between V atoms located at neighboring layers, with a Curie-Weiss constant of 3.14 K. Such ferromagnetic behavior was interpreted as resulting from a superexchange interaction through the network of strong OH····O{sub H2O}, OH····N{sub CN}, and OH····O{sub NO} hydrogen bonds that connects neighboring layers. The interaction within the layer must be of antiferromagnetic nature and it was detected close to 2 K. - Graphical abstract: Coordination environment for the metals in vanadyl (II) nitroprusside dihydrate. Display Omitted - Highlights: • Crystal structure of vanadyl nitroprusside dehydrate. • Network of hydrogen bonds. • Magnetic interactions through a network of hydrogen bonds. • Layered transition metal nitroprussides.

  2. Complementary Hand Responses Occur in Both Peri- and Extrapersonal Space.

    Directory of Open Access Journals (Sweden)

    Tim W Faber

    Full Text Available Human beings have a strong tendency to imitate. Evidence from motor priming paradigms suggests that people automatically tend to imitate observed actions such as hand gestures by performing mirror-congruent movements (e.g., lifting one's right finger upon observing a left finger movement; from a mirror perspective. Many observed actions however, do not require mirror-congruent responses but afford complementary (fitting responses instead (e.g., handing over a cup; shaking hands. Crucially, whereas mirror-congruent responses don't require physical interaction with another person, complementary actions often do. Given that most experiments studying motor priming have used stimuli devoid of contextual information, this space or interaction-dependency of complementary responses has not yet been assessed. To address this issue, we let participants perform a task in which they had to mirror or complement a hand gesture (fist or open hand performed by an actor depicted either within or outside of reach. In three studies, we observed faster reaction times and less response errors for complementary relative to mirrored hand movements in response to open hand gestures (i.e., 'hand-shaking' irrespective of the perceived interpersonal distance of the actor. This complementary effect could not be accounted for by a low-level spatial cueing effect. These results demonstrate that humans have a strong and automatic tendency to respond by performing complementary actions. In addition, our findings underline the limitations of manipulations of space in modulating effects of motor priming and the perception of affordances.

  3. Electron transfer mechanism and the locality of the system-bath interaction: a comparison of local, semilocal, and pure dephasing models.

    Science.gov (United States)

    Weiss, Emily A; Katz, Gil; Goldsmith, Randall H; Wasielewski, Michael R; Ratner, Mark A; Kosloff, Ronnie; Nitzan, Abraham

    2006-02-21

    We simulate the effects of two types of dephasing processes, a nonlocal dephasing of system eigenstates and a dephasing of semilocal eigenstates, on the rate and mechanism of electron transfer (eT) through a series of donor-bridge-acceptor systems, D-B(N)-A, where N is the number of identical bridge units. Our analytical and numerical results show that pure dephasing, defined as the perturbation of system eigenstates through the system-bath interaction, does not disrupt coherent eT because it induces no localization; electron transfer may proceed through superexchange in a system undergoing only pure dephasing. A more physically reasonable description may be obtained via a system-bath interaction that reflects the perturbation of more local electronic structure by local nuclear distortions and dipole interactions. The degree of locality of this interaction is guided by the structure of the system Hamiltonian and by the nature of the measurement performed on the system (i.e., the nature of the environment). We compare our result from this "semilocal" model with an even more local phenomenological dephasing model. We calculate electron transfer rate by obtaining nonequilibrium steady-state solutions for the elements of a reduced density matrix; a semigroup formalism is used to write down the dissipative part of the equation of motion.

  4. Mechanism of Occurring Over-Voltage Phenomena in Distributed Power System on Energization of Transformers

    Science.gov (United States)

    Nakachi, Yoshiki; Ueda, Fukashi; Kajikawa, Takuya; Amau, Tooru; Kameyama, Hirokazu; Ito, Hisanori

    This paper verifies the mechanism of occurring over voltage phenomena in the distributed power system on energizing the transformer. This over-voltage, which is observed at the actual distributed power system, with heavy inrush current is found to occur at about 0.1-0.2sec after the energizing and continue for a duration of more than 0.1[sec]. There is a concern that this over-voltage may operate the protection relay and deteriorate the insulation of apparatus. It is basically caused by the resonance between the shunt capacitors and saturated/unsaturated magnetizing inductance of transformer, system inductance. By using analytical formulation of a simple equivalent circuit, its mechanism has been verified through simulations carried out by using EMTP. Moreover, the sympathetic interaction between transformers is prolonged the duration of the over-voltage by the field test data is discussed in this paper.

  5. Immune Reconstitution Inflammatory Syndrome Occurring in a Kidney Transplant Patient with Extrapulmonary Tuberculosis

    Science.gov (United States)

    Ledesma, Kandria Jumil; Liu, Jessie

    2017-01-01

    Tuberculosis (TB) occurring in solid organ transplantation (SOT) is associated with significant morbidity and mortality usually due to delays in diagnosis, drug toxicity encountered with antimycobacterial therapy, and drug-drug interactions. TB in SOT patients may mimic other infectious and noninfectious posttransplant complications such as posttransplant lymphoproliferative disorder (PTLD) and systemic cytomegalovirus infection. Immune reconstitution inflammatory syndrome (IRIS) is a host response resulting in paradoxical worsening of an infectious disease which occurs after the employment of effective therapy and reversal of an immunosuppressed state. We describe the development of immune reconstitution inflammatory syndrome (IRIS), a unique complication occurring during the treatment of extrapulmonary tuberculosis occurring after transplant which resulted from decreasing immunosuppression in a patient who received Alemtuzumab induction therapy. Although (IRIS) has been originally described in HIV/AIDS patients receiving highly active antiretroviral therapy (HAART), solid organ transplant recipients with diagnosed or occult TB whose immune system may undergo immune reconstitution during their posttransplant course represent a new high risk group.

  6. Immune Reconstitution Inflammatory Syndrome Occurring in a Kidney Transplant Patient with Extrapulmonary Tuberculosis.

    Science.gov (United States)

    Iglesias, Jose; Ledesma, Kandria Jumil; Couto, Paul J; Liu, Jessie

    2017-01-01

    Tuberculosis (TB) occurring in solid organ transplantation (SOT) is associated with significant morbidity and mortality usually due to delays in diagnosis, drug toxicity encountered with antimycobacterial therapy, and drug-drug interactions. TB in SOT patients may mimic other infectious and noninfectious posttransplant complications such as posttransplant lymphoproliferative disorder (PTLD) and systemic cytomegalovirus infection. Immune reconstitution inflammatory syndrome (IRIS) is a host response resulting in paradoxical worsening of an infectious disease which occurs after the employment of effective therapy and reversal of an immunosuppressed state. We describe the development of immune reconstitution inflammatory syndrome (IRIS), a unique complication occurring during the treatment of extrapulmonary tuberculosis occurring after transplant which resulted from decreasing immunosuppression in a patient who received Alemtuzumab induction therapy. Although (IRIS) has been originally described in HIV/AIDS patients receiving highly active antiretroviral therapy (HAART), solid organ transplant recipients with diagnosed or occult TB whose immune system may undergo immune reconstitution during their posttransplant course represent a new high risk group.

  7. Profiles in patient safety: when an error occurs.

    Science.gov (United States)

    Hobgood, Cherri; Hevia, Armando; Hinchey, Paul

    2004-07-01

    Medical error is now clearly established as one of the most significant problems facing the American health care system. Anecdotal evidence, studies of human cognition, and analysis of high-reliability organizations all predict that despite excellent training, human error is unavoidable. When an error occurs and is recognized, providers have a duty to disclose the error. Yet disclosure of error to patients, families, and hospital colleagues is a difficult and/or threatening process for most physicians. A more thorough understanding of the ethical and social contract between physicians and their patients as well as the professional milieu surrounding an error may improve the likelihood of its disclosure. Key among these is the identification of institutional factors that support disclosure and recognize error as an unavoidable part of the practice of medicine. Using a case-based format, this article focuses on the communication of error with patients, families, and colleagues and grounds error disclosure in the cultural milieu of medial ethics.

  8. Lupus vulgaris occurring in a locus minoris resistentiae.

    Science.gov (United States)

    Long, Richard; Beatch, Anita; Lee, Mao-Cheng; Cheung-Lee, Melody; Wasel, Norman

    2009-01-01

    The pathogenesis of lupus vulgaris, a form of cutaneous tuberculosis, is not always clear, especially in patients who do not have coexistent extracutaneous tuberculosis and in patients with single lesions. To report a case of lupus vulgaris in a locus minoris resistentiae (a site of reduced resistance) and to use a unique set of clinical circumstances and laboratory tests to reconstruct the pathogenesis of the lesion and the response to treatment. Lupus vulgaris can occur in a locus minoris resistentiae; local trauma and possibly other factors, such as increased temperature, topical corticosteroids, and the virulence of the infecting strain, may facilitate the growth of Mycobacterium tuberculosis present at a locus minoris resistentiae as a result of a silent bacillemia.

  9. A huge glandular odontogenic cyst occurring at posterior mandible

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2004-12-15

    The glandular odontogenic cyst is a rare lesion described in 1987. It generally occurs at anterior region of mandible in adults over the age of 40 and has a slight tendency to recur. Histopathologically, a cystic cavity lined by a nonkeratinized, stratified squamous, or cuboidal epithelium varying in thickness is found including a superficial layer with glandular or pseudoglandular structures. A 21-year-old male visited Dankook University Dental Hospital with a chief complaint of swelling of the left posterior mandible. Radiographically, a huge multilocular radiolucent lesion involving impacted 3rd molar at the posterior mandible was observed. Buccolingual cortical expansion with partial perforation of buccal cortical bone was also shown. Histopathologically, this lesion was lined by stratified squamous epithelium with glandular structures in areas of plaque-like thickening. The final diagnosis was made as a glandular odontogenic cyst.

  10. General properties of grapevine viruses occurring in Hungary

    Directory of Open Access Journals (Sweden)

    Eszter Cseh

    2012-03-01

    Full Text Available The past fifty years important advances have been made in the field of grapevine virus research, including characterization of pathogens and control measurements. Still the occurrence of Grapevine fanleaf virus (GFLV, Arabis mosaic virus (ArMV, Tomato black ring virus (TBRV, Grapevine chrome mosaic virus (GCMV, Alfalfa mosaic virus (AMV, Grapevine Bulgarian latent virus (GBLV, Grapevine fleck virus (GFkV, Grapevine leafroll- associated viruses (GLRaV1-4, Grapevine virus A (GVA, Grapevine virus B (GVB and Grapevine rupestris stem pitting- associated virus (GRSPaV have been reported in Hungary and characterized by conventional methods as woody indexing, herbaceous indexing and serological methods. Among grapevine viruses the Grapevine line pattern virus (GLPV seems to be uncial; because it was reported only in Hungary. Causal agents of several grapevine diseases, like enation, vein necrosis and vein mosaic remained undiscovered. These virus-like diseases occurred only sporadically, without economic importance.

  11. Where will tropical cyclogenesis occur around a preexisting tropical cyclone?

    Science.gov (United States)

    Shi, Wenli; Fei, Jianfang; Huang, Xiaogang; Ma, Zhanhong

    2017-01-01

    An observational study focusing on the locations of tropical cyclogenesis induced by tropical cyclone energy dispersion (TCED) in the western North Pacific is conducted. Statistical results indicate that the cyclogenesis cases associated with TCED widely occur around preexisting tropical cyclones (TCs). In addition to the typical scenario of cyclogenesis to the southeast of a preexisting TC, new TCs can even form in the east or southwest directions at distances ranging from 1000 km to 3500 km. Further analyses reveal that the locations of cyclogenesis are mainly governed by large-scale environments via regulating the patterns of Rossby wave trains. The observational relationships between wave train regimes and the structures of environmental flows are revealed, which are broadly consistent with previous idealized numerical simulations. The results in this study provide a valuable reference for the prediction of cyclogenesis considering the TCED mechanism.

  12. Forecasting seizures in dogs with naturally occurring epilepsy.

    Science.gov (United States)

    Howbert, J Jeffry; Patterson, Edward E; Stead, S Matt; Brinkmann, Ben; Vasoli, Vincent; Crepeau, Daniel; Vite, Charles H; Sturges, Beverly; Ruedebusch, Vanessa; Mavoori, Jaideep; Leyde, Kent; Sheffield, W Douglas; Litt, Brian; Worrell, Gregory A

    2014-01-01

    Seizure forecasting has the potential to create new therapeutic strategies for epilepsy, such as providing patient warnings and delivering preemptive therapy. Progress on seizure forecasting, however, has been hindered by lack of sufficient data to rigorously evaluate the hypothesis that seizures are preceded by physiological changes, and are not simply random events. We investigated seizure forecasting in three dogs with naturally occurring focal epilepsy implanted with a device recording continuous intracranial EEG (iEEG). The iEEG spectral power in six frequency bands: delta (0.1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-30 Hz), low-gamma (30-70 Hz), and high-gamma (70-180 Hz), were used as features. Logistic regression classifiers were trained to discriminate labeled pre-ictal and inter-ictal data segments using combinations of the band spectral power features. Performance was assessed on separate test data sets via 10-fold cross-validation. A total of 125 spontaneous seizures were detected in continuous iEEG recordings spanning 6.5 to 15 months from 3 dogs. When considering all seizures, the seizure forecasting algorithm performed significantly better than a Poisson-model chance predictor constrained to have the same time in warning for all 3 dogs over a range of total warning times. Seizure clusters were observed in all 3 dogs, and when the effect of seizure clusters was decreased by considering the subset of seizures separated by at least 4 hours, the forecasting performance remained better than chance for a subset of algorithm parameters. These results demonstrate that seizures in canine epilepsy are not randomly occurring events, and highlight the feasibility of long-term seizure forecasting using iEEG monitoring.

  13. Late Acute Rejection Occuring in Liver Allograft Recipients

    Directory of Open Access Journals (Sweden)

    Eric M Yoshida

    1996-01-01

    Full Text Available To study the effect of immunosuppressive reduction on the incidence and consequence of late acute rejection (LAR in liver allograft recipients, mean daily prednisone dose, mean cyclosporine A (CsA trough and nadir levels were retrospectively reviewed for the nearest 12-week period preceding six episodes of LAR in five liver allograft recipients (group 1. Results were compared with those from a cohort of 12 liver allograft recipients who did not develop LAR (group 2. LAR was defined as acute rejection occurring more than 365 days post-transplantation. Median follow-up for both groups was similar (504 days, range 367 to 1050, versus 511 days, range 365 to 666, not significant. Mean trough CsA levels were lower in patients with LAR compared with those without (224±66 ng/mL versus 233±49 ng/mL but the difference was not statistically significant. In contrast, mean daily prednisone dose (2.5±1.6 mg/ day versus 6.5±2.9 mg/day, P=0.007 and CsA nadir values (129±60 ng/mL versus 186±40 ng/mL, P=0.03 were significantly lower in patients who developed LAR compared with those who did not. Five of six episodes (83% of LAR occurred in patients receiving less than 5 mg/day of prednisone, versus a single LAR episode in only one of 12 patients (8% receiving prednisone 5 mg/day or more (P=0.004. In all but one instance, LAR responded to pulse methylprednisolone without discernible affect on long term graft function. The authors conclude that liver allograft recipients remain vulnerable to acute rejection beyond the first post-transplant year; and reduction of immunosuppressive therapy, particularly prednisone, below a critical, albeit low dose, threshold increases the risk of LAR.

  14. Mud Flow Characteristics Occurred in Izuoshima Island, 2013

    Science.gov (United States)

    Takebayashi, H.; Egashira, S.; Fujita, M.

    2015-12-01

    Landslides and mud flows were occurred in the west part of the Izuoshima Island, Japan on 16 October 2013. The Izuoshima Island is a volcanic island and the land surface is covered by the volcanic ash sediment in 1m depth. Hence, the mud flow with high sediment concentration was formed. The laminar layer is formed in the debris flow from the bed to the fluid surface. On the other hand, the laminar flow is restricted near the bed in the mud flow and the turbulence flow is formed on the laminar flow layer. As a result, the equilibrium slope of the mud flow becomes smaller comparing to the debris flow. In this study, the numerical analysis mud flow model considering the effect of turbulence flow on the equilibrium slope of the mud flow is developed. Subsequently, the model is applied to the mud flow occurred in the Izuoshima Island and discussed the applicability of the model and the flow characteristics of the mud flow. The differences of the horizontal flow areas between the simulated results and the field data are compared and it was found that the outline of the horizontal shape of the flow areas is reproduced well. Furthermore, the horizontal distribution of the erosion and deposition area is reproduced by the numerical analysis well except for the residential area (Kandachi area). Kandachi area is judged as the erosion area by the field observation, but the sediment was deposited in the numerical analysis. It is considered that the 1.5hour heavy rain over 100mm/h after the mud flow makes the discrepancy. The difference of the horizontal distribution of the maximum flow surface elevation between the simulated results and the field data are compared and it was found that the simulated flow depth is overestimated slightly, because of the wider erosion area due to the coarse resolution elevation data. The averaged velocity and the depth of the mud flow was enough large to collapse the houses.

  15. Altered dopamine signaling in naturally occurring maternal neglect.

    Directory of Open Access Journals (Sweden)

    Stephen C Gammie

    , especially within regions involved in reward, is involved in naturally occurring neglect and that MaD1 mice are a useful model for understanding the basis of naturally occurring neglect.

  16. Theoretical investigation of the magnetic exchange interactions in copper(II) oxides under chemical and physical pressures.

    Science.gov (United States)

    Rocquefelte, Xavier; Schwarz, Karlheinz; Blaha, Peter

    2012-01-01

    It remains a challenge to understand the unconventional mechanisms that cause high-T(C) superconductivity in cuprate superconductors, high-T(C) multiferroicity in CuO, or low-dimensional magnetism in the spin-Peierls transition compounds such as CuGeO(3). A common feature of all these copper oxide compounds (containing Cu(2+) ions) is the presence of large magnetic superexchange interactions J. It is a general strategy to apply chemical and/or physical pressure in order to tune these exotic properties. Here we show theoretically, for the first time, the impact of physical pressure on J on CuO, for which we predict a strong enhancement of the low-dimensionality of the magnetic interactions and the spin-frustration at high-pressures. Such modifications are expected to strongly influence the multiferroic properties of CuO. We finally demonstrate that PBE0 hybrid DFT calculations provide reliable J values for a wide range of copper(II) oxides compounds, i.e. CuGeO(3), BaCu(2)Si(2)O(7), BaCu(2)Ge(2)O(7), and La(2)CuO(4).

  17. Intravenous Topiramate: Pharmacokinetics in Dogs with Naturally-Occurring Epilepsy

    Directory of Open Access Journals (Sweden)

    Irene Vuu

    2016-12-01

    Full Text Available Barriers to developing treatments for human status epilepticus (SE include the inadequacy of experimental animal models. In contrast, naturally-occurring canine epilepsy is similar to the human condition and can serve as a platform to translate research from rodents to humans. The objectives of this study were to characterize the pharmacokinetics (PK of an intravenous (IV dose of topiramate (TPM in dogs with epilepsy, and evaluate its effect on intracranial electroencephalographic (iEEG features. Five dogs with naturally occurring epilepsy were used for this study. Three were getting at least one antiseizure drug as maintenance therapy including phenobarbital (PB. Four (ID 1-4 were used for the 10 mg/kg IV TPM + PO TPM study, and three (ID 3-5 were used for the 20 mg/kg IV TPM study. IV TPM was infused over 5 minutes at both doses. The animals were observed for vomiting, diarrhea, ataxia, and lethargy. Blood samples were collected at scheduled pre- and post-dose times. Plasma concentrations were measured using a validated HPLC-MS method. Non-compartmental and population compartmental modeling were performed (Phoenix WinNonLin and NLME using plasma concentrations from all dogs in the study. Intracranial EEG (iEEG was acquired in one dog. The difference between averaged iEEG energy levels at 15 minutes pre- and post-dose was assessed using a Kruskal-Wallis test. No adverse events were noted. Topiramate concentration-time profiles were best fit by a two-compartment model. PB co-administration was associated with a 5.6 fold greater clearance and a ~4 fold shorter elimination half-life. iEEG data showed that TPM produced a significant energy increase at frequencies >4 Hz across all 16 electrodes within 15 minutes of dosing. Simulations suggested that dogs on an enzyme inducer would require 25 mg/kg, while dogs on non-inducing drugs would need 20 mg/kg to attain the target concentration (20-30 µg/mL at 30-minutes post-dose.This study shows that IV

  18. Cortical spreading depression occurs during elective neurosurgical procedures.

    Science.gov (United States)

    Carlson, Andrew P; William Shuttleworth, C; Mead, Brittany; Burlbaw, Brittany; Krasberg, Mark; Yonas, Howard

    2017-01-01

    OBJECTIVE Cortical spreading depression (CSD) has been observed with relatively high frequency in the period following human brain injury, including traumatic brain injury and ischemic/hemorrhagic stroke. These events are characterized by loss of ionic gradients through massive cellular depolarization, neuronal dysfunction (depression of electrocorticographic [ECoG] activity) and slow spread (2-5 mm/min) across the cortical surface. Previous data obtained in animals have suggested that even in the absence of underlying injury, neurosurgical manipulation can induce CSD and could potentially be a modifiable factor in neurosurgical injury. The authors report their initial experience with direct intraoperative ECoG monitoring for CSD. METHODS The authors prospectively enrolled patients undergoing elective craniotomy for supratentorial lesions in cases in which the surgical procedure was expected to last > 2 hours. These patients were monitored for CSD from the time of dural opening through the time of dural closure, using a standard 1 × 6 platinum electrode coupled with an AC or full-spectrum DC amplifier. The data were processed using standard techniques to evaluate for slow potential changes coupled with suppression of high-frequency ECoG propagating across the electrodes. Data were compared with CSD validated in previous intensive care unit (ICU) studies, to evaluate recording conditions most likely to permit CSD detection, and identify likely events during the course of neurosurgical procedures using standard criteria. RESULTS Eleven patients underwent ECoG monitoring during elective neurosurgical procedures. During the periods of monitoring, 2 definite CSDs were observed to occur in 1 patient and 8 suspicious events were detected in 4 patients. In other patients, either no events were observed or artifact limited interpretation of the data. The DC-coupled amplifier system represented an improvement in stability of data compared with AC-coupled systems. Compared

  19. OCCURANCE OF HISTAMINE IN FISH PRODUCTS ON MARKET

    Directory of Open Access Journals (Sweden)

    R. Mancusi

    2012-08-01

    Full Text Available Histamine fish poisoning is quite common and occur in consequence of microbial decarboxylase whose activity begin early in the post-mortem but are triggered in consequence of abuse in the shelf life of fish products. In this study forty-eight samples of tuna, mackerel, anchovies, sardines, fresh or processed were sampled from fish shops and supermarkets in the City of Bologna in the period from January to July 2010. Concentration of histamine was assessed using ELISA quantitative test and presence of psicrotrophic histamine forming bacteria was searched using a modified Niven agar medium which allow detection of suspect colonies that were confirmed by PCR for detecting the presence of the histidine decarboxylase genes in their DNA. The positive colonies were then identified on the basis of their morphology, Gram reaction and biochemical characteristics with API20E. The differential capability of the Niven agar was found to be low and approximately one fifth of the suspect colonies were confirmed by the PCR test, which however included both strong and weak histamine producing strains. The presence of Morganella morganii was associated with concentration of histamine 460 mg∙kg-1 above the allowed limit in a sample of tuna sampled from a fish shop. The same bacterium was found in samples of Atlantic horse mackerel (Trachurus trachurus. High histamine concentration (between 258 and > 300 mg∙kg-1 were observed in salted European pilchard and European anchovy (228 mg∙kg-1 sold loose in supermarkets. Because temperature abuse could occur when Tuna (fresh/defrozen are hold on chopping board to sell fresh cuts and during shelf life of salted pilchard and pickled anchovies held in opened cans in chilled display cabinets for extended period, which might results in very high histamine concentration, controls on time and temperature at the retail, in addition to those done during the harvest and processing are needed. The studies aiming at

  20. Discernible but limited introgression has occurred where Trichinella nativa and the T6 genotype occur in sympatry.

    Science.gov (United States)

    Dunams-Morel, Detiger B; Reichard, Mason V; Torretti, Luigi; Zarlenga, Dante S; Rosenthal, Benjamin M

    2012-04-01

    The genetic diversity within and among parasite populations provides clues to their evolutionary history. Here, we sought to determine whether mitochondrial and microsatellite DNA variation could be used to evaluate the extent of differentiation, gene flow and historical reproductive isolation among the freeze resistant parasites Trichinella nativa and the Trichinella T6 genotype infecting wolverines (Gulo gulo) in Nunavut, Canada. To this end, we genotyped Trichinella isolates derived from the diaphragms of 39 wolverines from this locale to reference strains of T. nativa and the Trichinella T6 genotype. Results showed that among a subset of 13 isolates examined, individuals resembled T. nativa in their mitochondrial DNA, but resembled the Trichinella T6 genotype when assayed at expansion segment V and the internal transcribed spacer of the nuclear rDNA. To adjudicate among these conflicting diagnoses, we further characterized each isolate at several nuclear microsatellite loci and again compared these to data from reference strains. Statistical assignment established that the nuclear genomes of most Nunavut isolates corresponded to those of the Trichinella T6 genotype; however, two isolates corresponded to T. nativa, and one isolate exhibited equal similarity to both reference strains. Taken as a whole, the evidence suggests that these isolates derive from the T. nativa matrilineage, but that their nuclear genomes resemble individuals previously designated as Trichinella T6. Assuming distinct lineages, this argues for cross-hybridization among these genotypes. Although introgression has occurred, recognizable genetic distinctions persist. One possibility is that selection disfavors the survival of hybrid offspring in most instances. Alternatively, the recent disappearance of glacial barriers might have increased contact, and therefore introgression. Broader geographic sampling will be required to determine the extent to which hybridization occurs beyond this

  1. GROWTH OF NATURALLY OCCURING Listeria innocua IN COPPA DI TESTA

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    G. Merialdi

    2010-06-01

    Full Text Available Coppa di testa is a traditional cooked pork salami produced in different Italian regions. The main raw material is deboned meat of pork head with the addition of tongue and rind. After a long (3-5 h high temperature (97°C cooking, additives and flavourings are added and the salami is prepared. After cooling the salami is often portioned and vacuum- packaged. In this study the growth of naturally occurring contamination of Listeria innocua in three batches of vacuum packaged Coppa di testa, stored at 4°C for 80 days, is described. The average max was 0.24 (days-1 and the average doubling time was 2.87 days. The maximum growth level ranged from 4.90 to 8.17 (log10 cfu/g. These results indicate that Coppa di testa definitely supports the growth of Listeria innocua in the considered storage conditions. Taking into account that at 4°C Listeria monocytogenes strains are associated with higher grow rates than L. innocua, these results emphasize the importance of preventing Listeria monocytogenes contamination in the production stages following cooking.

  2. Does Temporal Integration Occur for Unrecognizable Words in Visual Crowding?

    Science.gov (United States)

    Zhou, Jifan; Lee, Chia-Lin; Li, Kuei-An; Tien, Yung-Hsuan; Yeh, Su-Ling

    2016-01-01

    Visual crowding-the inability to see an object when it is surrounded by flankers in the periphery-does not block semantic activation: unrecognizable words due to visual crowding still generated robust semantic priming in subsequent lexical decision tasks. Based on the previous finding, the current study further explored whether unrecognizable crowded words can be temporally integrated into a phrase. By showing one word at a time, we presented Chinese four-word idioms with either a congruent or incongruent ending word in order to examine whether the three preceding crowded words can be temporally integrated to form a semantic context so as to affect the processing of the ending word. Results from both behavioral (Experiment 1) and Event-Related Potential (Experiment 2 and 3) measures showed congruency effect in only the non-crowded condition, which does not support the existence of unconscious multi-word integration. Aside from four-word idioms, we also found that two-word (modifier + adjective combination) integration-the simplest kind of temporal semantic integration-did not occur in visual crowding (Experiment 4). Our findings suggest that integration of temporally separated words might require conscious awareness, at least under the timing conditions tested in the current study.

  3. Conformational Flexibility Differentiates Naturally Occurring Bet v 1 Isoforms.

    Science.gov (United States)

    Grutsch, Sarina; Fuchs, Julian E; Ahammer, Linda; Kamenik, Anna S; Liedl, Klaus R; Tollinger, Martin

    2017-06-03

    The protein Bet v 1 represents the main cause for allergic reactions to birch pollen in Europe and North America. Structurally homologous isoforms of Bet v 1 can have different properties regarding allergic sensitization and Th2 polarization, most likely due to differential susceptibility to proteolytic cleavage. Using NMR relaxation experiments and molecular dynamics simulations, we demonstrate that the initial proteolytic cleavage sites in two naturally occurring Bet v 1 isoforms, Bet v 1.0101 (Bet v 1a) and Bet v 1.0102 (Bet v 1d), are conformationally flexible. Inaccessible cleavage sites in helices and strands are highly flexible on the microsecond-millisecond time scale, whereas those located in loops display faster nanosecond-microsecond flexibility. The data consistently show that Bet v 1.0102 is more flexible and conformationally heterogeneous than Bet v 1.0101. Moreover, NMR hydrogen-deuterium exchange measurements reveal that the backbone amides in Bet v 1.0102 are significantly more solvent exposed, in agreement with this isoform's higher susceptibility to proteolytic cleavage. The differential conformational flexibility of Bet v 1 isoforms, along with the transient exposure of inaccessible sites to the protein surface, may be linked to proteolytic susceptibility, representing a potential structure-based rationale for the observed differences in Th2 polarization and allergic sensitization.

  4. Characteristics of Cherenkov Radiation in Naturally Occuring Ice

    CERN Document Server

    Mikkelsen, R E; Uggerhøj, U I; Klein, S R

    2016-01-01

    We revisit the theory of Cherenkov radiation in uniaxial crystals. Historically, a number of flawed attempts have been made at explaining this radiation phenomenon and a consistent error-free description is nowhere available. We apply our calculation to a large modern day telescope - IceCube. Being located at the Antarctica, this detector makes use of the naturally occuring ice as a medium to generate Cherenkov radiation. However, due to the high pressure at the depth of the detector site, large volumes of hexagonal ice crystals are formed. We calculate how this affects the Cherenkov radiation yield and angular dependence. We conclude that the effect is small, at most about a percent, and would only be relevant in future high precision instruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For radio-Cherenkov experiments which use the presence of a clear Cherenkov cone to determine the arrival direction, any variation in emission angle will directly and linearly translate into a change in ap...

  5. Treatment of spontaneously occurring veterinary tumors with photodynamic therapy

    Science.gov (United States)

    Panjehpour, Masoud; Legendre, Alfred; Sneed, Rick E.; Overholt, Bergein F.

    1992-06-01

    Chloroaluminum phthalocyanine tetrasulfonate was administered intravenously (1.0 mg/kg) to client owned cats and a dog with spontaneously occurring squamous cell carcinoma of head and neck. Light was delivered 48 hours post injection of the photosensitizer. An argon- pumped dye-laser was used to illuminate the lesions with 675 nm light delivered through a microlens fiber and/or a cylindrical diffuser. The light dose was 100 J/cm2 superficially or 300 J/cm interstitially. Eleven photodynamic therapy treatments in seven cats and one dog were performed. Two cats received a second treatment in approximately sixty days after the initial treatment. The superficial dose of light was increased to 200 J/cm2 for the second treatment. While the longest follow-up is twelve months, the responses are encouraging. The dog had a complete response. Among the cats, three showed complete response, three showed partial response and one showed no response. One cat expired two days post treatment. It is early to evaluate the response in two cats that received second treatments. Photodynamic therapy with chloroaluminum phthalocyanine tetrasulfonate was effective in treating squamous cell carcinoma in pet animals.

  6. Hypokalaemia: common things occur commonly – a retrospective survey

    Science.gov (United States)

    Reid, Alasdair; Jones, Gareth; Isles, Chris

    2012-01-01

    Objectives To define the causes of hypokalaemia in an unselected adult population. Design Retrospective survey of biochemistry database. Setting District general hospital in southwest Scotland. Participants and main outcome measures There were 187,704 measurements of urea and electrolytes in 2010. Sixty-one patients had serum potassium feeding syndrome and inadequate potassium supplementation when patients were nil by mouth (37%). In 25% of patients a transient and profound fall in serum potassium appeared to coincide with their acute illness. Acute alcohol intoxication and/or alcohol withdrawal were prominent features in 11% of patients. More than one cause was commonly present. There were no cases of Bartter's, Gitelman's or Liddle's syndromes or of hypokalaemic periodic paralysis in this study. Conclusions Severe hypokalaemia <2.5 mmol/L occurs at least once a week in a district general hospital with a catchment population of around 150,000, suggesting there may be around 300 cases a week in the UK (population around 50,000,000). Diuretics, vomiting and diarrhoea are commonly implicated as are nutritional causes, acute illness and alcohol. Bartter's, Gitelman's, Liddle's syndrome and hypokalaemic period paralysis are all extremely uncommon. PMID:23323198

  7. CooVar: Co-occurring variant analyzer

    Directory of Open Access Journals (Sweden)

    Vergara Ismael A

    2012-11-01

    Full Text Available Abstract Background Evaluating the impact of genomic variations (GV on protein-coding transcripts is an important step in identifying variants of functional significance. Currently available programs for variant annotation depend on external databases or annotate multiple variants affecting the same transcript independently, which limits program use to organisms available in these databases or results in potentially incorrect or incomplete annotations. Findings We have developed CooVar (Co-occurring Variant Analyzer, a database-independent program for assessing the impact of GVs on protein-coding transcripts. CooVar takes GVs, reference genome sequence, and protein-coding exons as input and provides annotated GVs and transcripts as output. Other than similar programs, CooVar considers the combined impact of all GVs affecting the same transcript, generating biologically more accurate annotations. CooVar is operated from the command-line and supports standard file formats VCF, GFF/GTF, and GVF, which makes it easy to integrate into existing computational pipelines. We have extensively tested CooVar on worm and human data sets and demonstrate that it generates correct annotations in only a short amount of time. Conclusions CooVar is an easy-to-use and lightweight variant annotation tool that considers the combined impact of GVs on protein-coding transcripts. CooVar is freely available at http://genome.sfu.ca/projects/coovar/.

  8. Educational utilization of outstanding spherulitic rhyolite occurred in Cheongsong, Korea

    Science.gov (United States)

    Jang, Y. D.; Woo, H.

    2015-12-01

    Cheongsong is located in the central eastern area of South Korea. Unique spherulitic rhyolites occur in this region as dykes formed about 48 to 50 million years ago. Composed of quartz and feldspar these spherulitic rhyolites show various flowerlike shapes, such as chrysanthemum, dandelion, rose, carnation, sunflower, dahlia and so on, so they are called 'flower stones'. The spherulite indicates that it was undercooled caused by very fast cooling at a shallow depth near the surface and the variety of shapes resulted from the difference of crystallizing conditions. According to the condition, minerals start to crystallize homogeneously or heterogeneously and develop as rounded or fibrous shapes, representing beautiful patterns when combined. These spherulitic structures are very rare not only in Korea but also globally, being valuable for research and preservation because of their rarity, beauty and diversity. Cheongsong therefore applies to the UGG (UNESCO Global Geopark) in an attempt to popularize the flower stones and use them as education materials which can also be incorporated in other valuable sites. The exhibition center provides diverse types of flower stones in which visitors could learn about rhyolitic volcanism, crystallization and spherulite and can experience the process of changing a rough stone into a flower stone. A geotrail course has also been created, showing each type of flower stone on the outcrop and providing educational programs about geological mechanisms of the stones with a trained guide.

  9. Naturally occurring regulatory T cells: markers, mechanisms, and manipulation.

    Science.gov (United States)

    Schmetterer, Klaus G; Neunkirchner, Alina; Pickl, Winfried F

    2012-06-01

    Naturally occurring CD4(+)CD25(high) forkhead box protein 3 (FOXP3)(+) regulatory T cells (nTregs) are key mediators of immunity, which orchestrate and maintain tolerance to self and foreign antigens. In the recent 1.5 decades, a multitude of studies have aimed to define the phenotype and function of nTregs and to assess their therapeutic potential for modulating immune mediated disorders such as autoimmunity, allergy, and episodes of transplant rejection. In this review, we summarize the current knowledge on the biology of nTregs. We address the exact definition of nTregs by specific markers and combinations thereof, which is a prerequisite for the state-of-the-art isolation of defined nTreg populations. Furthermore, we discuss the mechanism by which nTregs mediate immunosuppression and how this knowledge might translate into novel therapeutic modalities. With first clinical studies of nTreg-based therapies being finished, questions concerning the reliable sources of nTregs are becoming more and more eminent. Consequently, approaches allowing conversion of CD4(+) T cells into nTregs by coculture with antigen-presenting cells, cytokines, and/or pharmacological agents are discussed. In addition, genetic engineering approaches for the generation of antigen-specific nTregs are described.

  10. Naturally occurring glasses: analogues for radioactive waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C.; Haaker, R.F.

    1979-04-01

    Volcanic glasses are very often altered by weathering and leaching and recrystallize to their fine-grained equivalents (rhyolites, felsites). The oldest volcanic glasses are dated at 40 million years before the present, but the majority are much younger. Devitrification textures was produced experimentally; and hydration rates for volcanic glasses were determined as a function of composition, temperature, and climate. Presence of water and temperature are the most important rate controlling variables. Even material that may still be described as glassy often exhibits evidence of alteration and recrystallization. Of the volcanic glasses that are preserved in the geologic record, it would be rare to describe such a glass as pristine. Despite the common alteration and recrystallization effects observed in volcanic glasses, glasses formed as a result of impact, tektites and lunar glasses, may occur in substantially unaltered form. In the case of tektites, their resistance to alteration is a result of their high SiO/sub 2/ content and low alkali content. Lunar glasses have been preserved for hundreds of millions of years because they exist in an environment with a low oxygen fugacity and an extremely low water vapor partial presssure. Thus one might expect glasses of particular compositions or in specific types of environment to be stable for long periods of time. These conclusions are applied to radioactive waste disposal over several time periods (0-30h, 30h-20y, 20-200y).

  11. Mass transfer trends occurring in engineered ex vivo tissue scaffolds.

    Science.gov (United States)

    Moore, Marc; Sarntinoranont, Malisa; McFetridge, Peter

    2012-08-01

    In vivo the vasculature provides an effective delivery system for cellular nutrients; however, artificial scaffolds have no such mechanism, and the ensuing limitations in mass transfer result in limited regeneration. In these investigations, the regional mass transfer properties that occur through a model scaffold derived from the human umbilical vein (HUV) were assessed. Our aim was to define the heterogeneous behavior associated with these regional variations, and to establish if different decellularization technologies can modulate transport conditions to improve microenvironmental conditions that enhance cell integration. The effect of three decellularization methods [Triton X-100 (TX100), sodium dodecyl sulfate (SDS), and acetone/ethanol (ACE/EtOH)] on mass transfer, cellular migration, proliferation, and metabolic activity were assessed. Results show that regional variation in tissue structure and composition significantly affects both mass transfer and cell function. ACE/EtOH decellularization was shown to increase albumin mass flux through the intima and proximate-medial region (0-250 μm) when compared with sections decellularized with TX100 or SDS; although, mass flux remained constant over all regions of the full tissue thickness when using TX100. Scaffolds decellularized with TX100 were shown to promote cell migration up to 146% further relative to SDS decellularized samples. These results show that depending on scaffold derivation and expectations for cellular integration, specificities of the decellularization chemistry affect the scaffold molecular architecture resulting in variable effects on mass transfer and cellular response.

  12. Franckeite as a naturally occurring van der Waals heterostructure

    Science.gov (United States)

    Molina-Mendoza, Aday J.; Giovanelli, Emerson; Paz, Wendel S.; Niño, Miguel Angel; Island, Joshua O.; Evangeli, Charalambos; Aballe, Lucía; Foerster, Michael; van der Zant, Herre S. J.; Rubio-Bollinger, Gabino; Agraït, Nicolás; Palacios, J. J.; Pérez, Emilio M.; Castellanos-Gomez, Andres

    2017-01-01

    The fabrication of van der Waals heterostructures, artificial materials assembled by individual stacking of 2D layers, is among the most promising directions in 2D materials research. Until now, the most widespread approach to stack 2D layers relies on deterministic placement methods, which are cumbersome and tend to suffer from poor control over the lattice orientations and the presence of unwanted interlayer adsorbates. Here, we present a different approach to fabricate ultrathin heterostructures by exfoliation of bulk franckeite which is a naturally occurring and air stable van der Waals heterostructure (composed of alternating SnS2-like and PbS-like layers stacked on top of each other). Presenting both an attractive narrow bandgap (<0.7 eV) and p-type doping, we find that the material can be exfoliated both mechanically and chemically down to few-layer thicknesses. We present extensive theoretical and experimental characterizations of the material's electronic properties and crystal structure, and explore applications for near-infrared photodetectors. PMID:28194037

  13. Characteristics of Watermelon Mosaic Virus Transmission Occurring in Korean Ginseng

    Directory of Open Access Journals (Sweden)

    Seung-Kook Choi

    2014-09-01

    Full Text Available Korean ginseng (Panax ginseng is the most popular herb for medical purpose in Korea. Recently, viral diseases from Korean ginseng showing various degrees of severe mottling, variegation and mosaic symptoms have caused quantity losses of Korean ginseng in a large number of farms. Watermelon mosaic virus (named WMVgin was identified as a causal agent for the disease of Korean ginseng. Interestingly, WMV-gin failed to infect both Korean ginseng plant and susceptible host species including cucurbitaceous plants by mechanical inoculation. However, WMV-gin could successfully infect Korean ginseng by transmission of two aphid species (Myzus persicae and Aphis gossypii. It is likely that transmission of WMV-gin was done by both the aphid species during feeding behavior of the two aphid species on Korean ginseng, though the aphids dislike feeding in Korea ginseng. Similarly, a strain of WMV (WMV-wm isolated from watermelon was transmitted successfully to Korean ginseng plant by the two aphid species, but not by mechanical inoculations. Transmission assays using M. persicae and A. gossypii clearly showed both WMV-gin and WMV-wm were not transmitted from infected Korean ginseng plant to cucurbit species that are good host species for WMV. These results suggest WMV disease occurring in Korean ginseng plant can be controlled by ecological approaches.

  14. Hemimegalencephaly: a study of abnormalities occurring outside the involved hemisphere.

    Science.gov (United States)

    Sato, N; Yagishita, A; Oba, H; Miki, Y; Nakata, Y; Yamashita, F; Nemoto, K; Sugai, K; Sasaki, M

    2007-04-01

    Hemimegalencephaly is a rare but well-known congenital malformation with ipsilateral enlargement of the hemicerebrum. However, very little is known about changes in structures outside the involved hemisphere in patients with this condition. We investigated morphologic abnormalities occurring outside the affected hemisphere by MR imaging in a large series of patients with hemimegalencephaly. MR imaging findings for 30 patients with hemimegalencephaly were retrospectively reviewed and evaluated for structures outside the involved hemisphere on routine MR images, such as cranial nerves (I, II, V), brain vessels, subdural and subarachnoid spaces, brain stem, and cerebellum, on both the ipsilateral and contralateral sides. The ipsilateral olfactory and optic nerves were enlarged in 8 (26.7%) and 1 (3.3%) of the 30 patients, respectively, without enlargement on the contralateral side. No asymmetry was noted in the trigeminal nerves. Asymmetric vascular dilations in the ipsilateral cerebral hemisphere were observed in 12 of the 30 patients (40%), in deep cerebral vessels in 11 patients (36.7%), and in superficial cerebral vessels in 8 patients (26.7%). Ipsilateral brain stem and hemicerebellar asymmetric enlargement was detected in 2 patients (6.7%) and 14 patients (46.7%), respectively. Abnormal cerebellar folia were observed on the ipsilateral side in 6 patients (20%) and on the contralateral side in 3 patients (10%). Ipsilateral olfactory nerve enlargement, cerebral vascular dilations, cerebellar enlargement, and bilateral or ipsilateral abnormal architecture of the cerebellar folia are often associated with hemimegalencephaly.

  15. Pulsed light inactivation of naturally occurring moulds on wheat grain.

    Science.gov (United States)

    Aron Maftei, Nicoleta; Ramos-Villarroel, Ana Y; Nicolau, Anca I; Martín-Belloso, Olga; Soliva-Fortuny, Robert

    2014-03-15

    Pulsed light (PL) is emerging as a non-thermal technology with excellent prospects for the decontamination of foods and food contact surfaces. Its application for mould inactivation on cereal grains would allow a reduction of storage losses as well as the prevention of mycotoxin contamination at a post-harvest level. The potential of PL for the decontamination of naturally occurring moulds on wheat grain was investigated in this study. Treatments of up to 40 flashes of a fluence of 0.4 J cm⁻² per pulse were applied to both sides of the grain, with an overall energy release ranging from 6.4 to 51.2 J g⁻¹. The most powerful treatment applied to wheat in this study (51.2 J g⁻¹) resulted in a mould reduction of approximately 4 log cycles on samples displaying an initial mould contamination level of 2.2 × 10⁵ CFU g⁻¹. At the same time, the seed germination percentage was only slightly affected. For PL treatments causing an inactivation of 3-4 log cycles, only 14-15% of the germination power of the wheat seeds was lost. The PL treatments attained greater microbial reductions for higher treatment times and lower initial mould loads. The absence of the UV portion of the radiation spectrum was found to significantly reduce the treatment effectiveness. © 2013 Society of Chemical Industry.

  16. Naturally occurring glasses: analogues for radioactive waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C.; Haaker, R.F.

    1979-04-01

    Volcanic glasses are very often altered by weathering and leaching and recrystallize to their fine-grained equivalents (rhyolites, felsites). The oldest volcanic glasses are dated at 40 million years before the present, but the majority are much younger. Devitrification textures was produced experimentally; and hydration rates for volcanic glasses were determined as a function of composition, temperature, and climate. Presence of water and temperature are the most important rate controlling variables. Even material that may still be described as glassy often exhibits evidence of alteration and recrystallization. Of the volcanic glasses that are preserved in the geologic record, it would be rare to describe such a glass as pristine. Despite the common alteration and recrystallization effects observed in volcanic glasses, glasses formed as a result of impact, tektites and lunar glasses, may occur in substantially unaltered form. In the case of tektites, their resistance to alteration is a result of their high SiO/sub 2/ content and low alkali content. Lunar glasses have been preserved for hundreds of millions of years because they exist in an environment with a low oxygen fugacity and an extremely low water vapor partial presssure. Thus one might expect glasses of particular compositions or in specific types of environment to be stable for long periods of time. These conclusions are applied to radioactive waste disposal over several time periods (0-30h, 30h-20y, 20-200y).

  17. Motor sequence learning occurs despite disrupted visual and proprioceptive feedback

    Directory of Open Access Journals (Sweden)

    Boyd Lara A

    2008-07-01

    Full Text Available Abstract Background Recent work has demonstrated the importance of proprioception for the development of internal representations of the forces encountered during a task. Evidence also exists for a significant role for proprioception in the execution of sequential movements. However, little work has explored the role of proprioceptive sensation during the learning of continuous movement sequences. Here, we report that the repeated segment of a continuous tracking task can be learned despite peripherally altered arm proprioception and severely restricted visual feedback regarding motor output. Methods Healthy adults practiced a continuous tracking task over 2 days. Half of the participants experienced vibration that altered proprioception of shoulder flexion/extension of the active tracking arm (experimental condition and half experienced vibration of the passive resting arm (control condition. Visual feedback was restricted for all participants. Retention testing was conducted on a separate day to assess motor learning. Results Regardless of vibration condition, participants learned the repeated segment demonstrated by significant improvements in accuracy for tracking repeated as compared to random continuous movement sequences. Conclusion These results suggest that with practice, participants were able to use residual afferent information to overcome initial interference of tracking ability related to altered proprioception and restricted visual feedback to learn a continuous motor sequence. Motor learning occurred despite an initial interference of tracking noted during acquisition practice.

  18. Naturally-occurring anti-Jka in infant twins.

    Science.gov (United States)

    Rumsey, D H; Nance, S J; Rubino, M; Sandler, S G

    1999-01-01

    Anti-Jka was detected by solid-phase red cell adherence (SPRCA) antibody detection and identification tests in the plasma of a 9-month-old female infant during a routine presurgical evaluation. The patient and her nonidentical twin sister, who also had anti-Jka in her plasma, were products of an uncomplicated in vitro fertilization, full-term pregnancy, and vaginal delivery. Neither twin had been transfused, recently infected, or treated with medication. Their mother had no prior pregnancies or transfusions. Red blood cells (RBCs) from the patient and her sister typed as Jk(a-b+) by direct hemagglutination, and this phenotype was confirmed by negative adsorption and elution studies. Both infants' plasma samples were strongly reactive with 20 examples of Jk(a+) RBCs and nonreactive with 20 examples of Jk(a-) RBCs by SPRCA assays. Anti-Jka was not detected in either twins' plasma by indirect antiglobulin tests by tube method in low-ionic- strength saline solution or polyethylene glycol, or with ficin- or papain-treated RBCs. Monocyte monolayer assays using Jk(a+) RBCs sensitized by either twins' serum were nonreactive (0%). RBCs from both parents typed as Jk(a+b+). Both parents' antibody detection test results by SPRCA assay were negative. The absence of a history of exposure to allogeneic RBCs or possible passive transfer of maternal or other alloantibody classifies these antibodies as naturally-occurring anti-Jka.

  19. Bladder uptake of liposomes after intravesical administration occurs by endocytosis.

    Directory of Open Access Journals (Sweden)

    Bharathi Raja Rajaganapathy

    Full Text Available Liposomes have been used therapeutically and as a local drug delivery system in the bladder. However, the exact mechanism for the uptake of liposomes by bladder cells is unclear. In the present study, we investigated the role of endocytosis in the uptake of liposomes by cultured human UROtsa cells of urothelium and rat bladder. UROtsa cells were incubated in serum-free media with liposomes containing colloidal gold particles for 2 h either at 37°C or at 4°C. Transmission Electron Microscopy (TEM images of cells incubated at 37°C found endocytic vesicles containing gold inside the cells. In contrast, only extracellular binding was noticed in cells incubated with liposomes at 4°C. Absence of liposome internalization at 4°C indicates the need of energy dependent endocytosis as the primary mechanism of entry of liposomes into the urothelium. Flow cytometry analysis revealed that the uptake of liposomes at 37°C occurs via clathrin mediated endocytosis. Based on these observations, we propose that clathrin mediated endocytosis is the main route of entry for liposomes into the urothelial layer of the bladder and the findings here support the usefulness of liposomes in intravesical drug delivery.

  20. Sexual recombination in Colletotrichum lindemuthianum occurs on a fine scale.

    Science.gov (United States)

    Souza, E A; Camargo, O A; Pinto, J M A

    2010-09-08

    Glomerella cingulata f. sp phaseoli is the sexual phase of the fungus Colletotrichum lindemuthianum, the causal agent of common bean anthracnose. This fungus is of great concern, because it causes large economic losses in common bean crops. RAPD markers of five populations of G. cingulata f. sp phaseoli from two Brazilian states were analyzed to determine if this population possesses the sexual reproductive potential to generate the genetic variation that is observed in this phytopathogen. We identified 128 polymorphic bands, amplified by 28 random primers. The estimates of genetic similarity in this analysis ranged from 0.43 to 1.00, and the dendrogram generated from analysis of all genotypes displayed five principal groups, coinciding with the five populations. Genetic differentiation was observed between the populations (GST=0.6455); 69% of the overall observed genetic variation was between individual populations and 31% of the variance was within the sub-populations. We identified significant levels of linkage disequilibrium in all populations. However, the values of the disequilibrium ranged from low to moderate, indicating that this pathogen maintains a genetic structure consistent with sexual reproduction. The mean contribution of sexual reproduction was determined by comparison of the amplitudes of genetic similarity of isolates from sexual and asexual phases. These results support the hypothesis that recombination plays an important role in determining the amplitude of variability in this pathogen population and that this determination occurs on a fine scale.

  1. Characteristics of Cherenkov radiation in naturally occurring ice

    Science.gov (United States)

    Mikkelsen, R. E.; Poulsen, T.; Uggerhøj, U. I.; Klein, S. R.

    2016-03-01

    We revisit the theory of Cherenkov radiation in uniaxial crystals. Historically, a number of flawed attempts have been made at explaining this radiation phenomenon, and a consistent error-free description is nowhere available. We apply our calculation to a large modern day telescope—IceCube. Located in Antarctica, this detector makes use of the naturally occurring ice as a medium to generate Cherenkov radiation. However, due to the high pressure at the depth of the detector site, large volumes of hexagonal ice crystals are formed. We calculate how this affects the Cherenkov radiation yield and angular dependence. We conclude that the effect is small, at most about a percent, and would only be relevant in future high-precision instruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For radio-Cherenkov experiments which use the presence of a clear Cherenkov cone to determine the arrival direction, any variation in emission angle will directly and linearly translate into a change in apparent neutrino direction. In closing, we also describe a simple experiment to test this formalism and calculate the impact of anisotropy on light yields from lead tungstate crystals as used, for example, in the CMS calorimeter at the CERN LHC.

  2. Polyomavirus and Naturally Occuring Neuroglial Tumors in Raccoons (Procyon Lotor).

    Science.gov (United States)

    Pesavento, Patricia A; Brostoff, Terza; Church, Molly E; Dela Cruz, Florante N; Woolard, Kevin D

    2016-01-01

    Polyomavirus (PyV) infections are widespread in human populations and, although generally associated with silent persistence, rarely cause severe disease. Among diseases convincingly associated with natural PyV infections of humans, there are remarkably different tissue tropisms and outcomes, including progressive multifocal leukoencephalopathy, transient or progressive nephropathy, and cancer. The variable character and unpredictable outcomes of infection attest to large gaps in our basic understanding of PyV biology. In particular, the rich history of research demonstrating the oncogenic potential of PyVs in laboratory animals begs the question of why cancer is not more often associated with infection. Raccoon polyomavirus (RacPyV), discovered in 2010, is consistently identified in neuroglial tumors in free-ranging raccoons in the western United States. Exposure to RacPyV is widespread, and RacPyV is detected in tissues of raccoons without tumors. Studying the relationship of RacPyV with its natural host is a unique opportunity to uncover cogent cellular targets and protein interactions between the virus and its host. Our hypothesis is that RacPyV, as an intact episome, alters cellular pathways within neural progenitor cells and drives oncogenesis. © The Author 2016. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. From minisatellites and genes: When do germinal mutations occur

    Energy Technology Data Exchange (ETDEWEB)

    Mohrenweiser, H. [Lawrence Livermore National Lab., CA (United States)

    1997-10-01

    Utilization of molecular techniques has provided insight into the molecular techniques has provided insight into the molecular techniques has provided insight into the molecular character and origins of spontaneous and induced germinal mutations. Review of the variants and disease loci suggests differences among loci in the frequency of nucleotide substitutions and more complex events. Mechanistic features associated with the alterations in DNA structure are observed in each variant class. The spectrum of mutations identified reflects the gene structure and the selective pressure generating disease phenotypes, and the techniques employed to screen for variation. Locus specificity in spectra has the potential to compromise estimates of increases in germinal gene mutation rates. Recent studies have identified mosaicism, rather than de novo mutation, as the explanation for the non-traditional pattern of inheritance of disease in some families. Mosaicism is a concern for studies of induced mutation rates as it reflects embryonic exposure of the parent of the proband. This is in contrast to the {open_quotes}normal expectation{close_quotes} that induced mutations result from parental exposure to genotoxins in the environment. Observations suggest that the germ cell stage sensitivity may reflect interaction of the mutagen and the loci screened. The mosaicism and germ cell stage issues, in conjunction with incomplete ascertainment of mutational events, increase the complexity of efforts to estimate induced germinal mutation rates and associated health consequences in populations exposed to genotoxic agents.

  4. Iron deficiency occurs frequently in children with cystic fibrosis.

    Science.gov (United States)

    Uijterschout, Lieke; Nuijsink, Marianne; Hendriks, Daniëlle; Vos, Rimke; Brus, Frank

    2014-05-01

    In adult CF patients iron deficiency (ID) is common and primarily functional due to chronic inflammation. No recent data are available on the cause of ID and iron deficiency anemia (IDA) in children with CF. Over the last decades onset of inflammation and pulmonary disease in children with CF is delayed by improved nutritional status. We questioned whether ID occurs in the same extent among children with CF as in adult CF patients. We therefore conducted a study to investigate the iron status of children with CF and to determine whether ID and IDA are associated with dietary iron intake, lung disease severity and Pseudomonas aeruginosa (PA) infection. Clinical charts of 53 children with CF aged 0-16 were reviewed. Follow-up varied from 1 to 14 years with 343 annual observations in total. Thirty-two children (60.4%) were iron deficient in at least 1 year and ID was present in 84 of 343 observations (24.5%). In 2011 ID was present in 9 children (17.0%). Ten children (18.9%) were anemic in at least 1 year and anemia was present in 13 of 328 observations (4.0%). IDA was present in at least 1 year in 6 children (11.3%). Ferritin (Fer) was positively associated with age. Higher Fer values found in older children represent an increased state of inflammation, rather than an improved iron status, and might increase the relative contribution of functional ID. This study shows that ID is common in relatively healthy, well-nourished children with CF. The mechanism of ID in children with CF is currently unknown. A prospective study using both soluble transferrin receptor and Fer as indicators for ID will provide more insight in the incidence and causes of ID in children with CF.

  5. Co-occurring disorders: policy and practice in Germany.

    Science.gov (United States)

    Hintz, Thomas; Mann, Karl

    2006-01-01

    The occurrence of substance use disorders (SUD) with other mental disorders-what is often referred to as co-occurring disorders (COD)-is a common phenomenon, but for a long time, little attention has been paid to this problem in Germany. During the last 25 years, however, COD awareness has increased due to a shift toward community-based services. Scientific research has also demonstrated the significance and clinical relevance of COD. High prevalence rates and evidence of poor clinical outcomes were found in German studies. Many practitioners as well as policymakers acknowledge that changes in systems of care are necessary to meet the requirements of COD patients. The traditional German system is currently divided into addiction services and mental health services (predominantly in inpatient settings), often resulting in ineffective sequential treatment for COD patients. Research demonstrates that integrative treatment models are more appropriate, and the division of services should be reorganized to help COD patients appropriately. Efforts have already been made to restructure healthcare systems toward a more flexible approach with improved networking between in- and outpatient services. A further issue is the general attitude toward SUD patients. Many practitioners continue to hold negative opinions (eg, "SUD patients are only weak-minded") or feel insecure when confronted with SUD. This results in SUD problems being frequently ignored or depreciated. Educational programs have been intensive over recent years to address this problem (eg, Fachkunde Sucht, an advanced training program on SUD). In general, treatment conditions for COD patients are improving, but further efforts are necessary. Guidelines and treatment strategies for COD patients have been recently published in Germany.

  6. Naturally occurring radiation sources: existing or planned exposure situation?

    Energy Technology Data Exchange (ETDEWEB)

    Hedemann-Jensen, Per [Danish Decommissioning, DK-4000 Roskilde (Denmark)

    2010-12-01

    After more than fifteen years of application, ICRP Publication 60 has been revised. The revision was based upon the concept of 'controllable dose' as the dose or sum of doses to an individual from a particular source that can reasonably be controlled by whatever means. The new recommendations have been published as ICRP Publication 103. The European Basic Safety Standards as well as the International Basic Safety Standards are currently under revision as a result of the new recommendations from ICRP. According to the ICRP, there have been indications that some changes to the structure and terminology of the system of protection were desirable in order to improve clarity and utility. In particular the distinction between practices and interventions may not have been clearly understood and the ICRP now recognises three types of exposure situations, which replace the previous categorisation into practices and interventions. These exposure situations are intended to cover the entire range of exposure situations: (1) planned exposure, (2) existing exposure and (3) emergency exposure. There are situations of exposure to naturally occurring radiation sources in different occupations, e.g. exposure to radon and radon progeny in workplaces other than where the exposure is required by or is directly related to the work and aircrew exposed to cosmic radiation. In the European (Euratom) and the International Basic Safety Standards, these exposure situations are treated conceptually different-either as a planned exposure situation or as an existing exposure situation. This note reviews the change of exposure situations from Publication 60 to Publication 103 and the implications for the revision of both the International and the European Basic Safety Standards. The paper draws some conclusions on the classification of the exposure situations in the two basic safety standards based on a logical interpretation of the ICRP recommendations. It is recommended that the

  7. Death in pediatric Cushing syndrome is uncommon but still occurs

    Science.gov (United States)

    Gkourogianni, Alexandra; Lodish, Maya B.; Zilbermint, Mihail; Lyssikatos, Charalampos; Belyavskaya, Elena; Keil, Margaret F.; Stratakis, Constantine A.

    2014-01-01

    Cushing syndrome (CS) in children is rare. Delayed diagnosis and treatment of CS may be associated with increased morbidity and, unfortunately, mortality. We performed a retrospective review of all patients with CS under the age of 18 referred to the NIH from 1998 to 2013 in order to describe deceased patients among cases of pediatric CS referred to the National Institutes of Health (NIH). The deaths of 4 children (3 females and 1 male), aged 7.5–15.5 years (mean age 11.2 years) with length of disease 2–4 years were recorded among 160 (2.5%) children seen at, or referred to the NIH over the last 15 years. All died at different institutions, prior to coming to the NIH (two of them) or after leaving NIH (two of them). Presenting symptoms included increasing weight and decreasing height gain, facial plethora, dorsocervical fat pad (webbed neck), striae, headache, vision disturbances and depression and other mood or behavior changes; there were no differences between how these patients presented and the others in our cohort. The causes of CS in the deceased patients were also not different, in fact, they spanned the entire spectrum of CS: pituitary disease (on of them), ectopic corticotropin production (one of them), and primary adrenal hyperplasia (1). In one patient, the cause of CS could not be verified. Three died of sepsis and one due to residual disease and complications of the primary tumor. Conclusions Despite advances in early diagnosis and treatment of pediatric CS, a 2.5% mortality rate was identified in a large cohort of patients with this condition referred to an experienced, tertiary care referral center (although these deaths occurred elsewhere). Pediatricians need to recognize the possibility of death, primarily due to sepsis, in a patient with pediatric CS and act accordingly. PMID:25241829

  8. Why Does REM Sleep Occur? A Wake-up Hypothesis

    Directory of Open Access Journals (Sweden)

    Dr. W. R. eKlemm

    2011-09-01

    Full Text Available Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses REM to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, 1 when first going to sleep, the brain plunges into Stage N3 (formerly called Stage IV, a deep abyss of sleep, and, as the night progresses, the sleep is punctuated by episodes of REM that become longer and more frequent toward morning, 2 conscious-like dreams are a reliable component of the REM state in which the dreamer is an active mental observer or agent in the dream, 3 the last awakening during a night’s sleep usually occurs in a REM episode during or at the end of a dream, 4 both REM and awake consciousness seem to arise out of a similar brainstem ascending arousal system 5 N3 is a functionally perturbed state that eventually must be corrected so that embodied brain can direct adaptive behavior, and 6 corticofugal projections to brainstem arousal areas provide a way to trigger increased cortical activity in REM to progressively raise the sleeping brain to the threshold required for wakefulness. This paper shows how the hypothesis conforms to common experience and has substantial predictive and explanatory power regarding the phenomenology of sleep in terms of ontogeny, aging, phylogeny, abnormal/disease states, cognition, and behavioral physiology. That broad range of consistency is not matched by competing theories, which are summarized herein. Specific ways to test this wake-up hypothesis are suggested. Such research could lead to a better understanding of awake consciousness.

  9. Preparation of metagenomic libraries from naturally occurring marine viruses.

    Science.gov (United States)

    Solonenko, Sergei A; Sullivan, Matthew B

    2013-01-01

    Microbes are now well recognized as major drivers of the biogeochemical cycling that fuels the Earth, and their viruses (phages) are known to be abundant and important in microbial mortality, horizontal gene transfer, and modulating microbial metabolic output. Investigation of environmental phages has been frustrated by an inability to culture the vast majority of naturally occurring diversity coupled with the lack of robust, quantitative, culture-independent methods for studying this uncultured majority. However, for double-stranded DNA phages, a quantitative viral metagenomic sample-to-sequence workflow now exists. Here, we review these advances with special emphasis on the technical details of preparing DNA sequencing libraries for metagenomic sequencing from environmentally relevant low-input DNA samples. Library preparation steps broadly involve manipulating the sample DNA by fragmentation, end repair and adaptor ligation, size fractionation, and amplification. One critical area of future research and development is parallel advances for alternate nucleic acid types such as single-stranded DNA and RNA viruses that are also abundant in nature. Combinations of recent advances in fragmentation (e.g., acoustic shearing and tagmentation), ligation reactions (adaptor-to-template ratio reference table availability), size fractionation (non-gel-sizing), and amplification (linear amplification for deep sequencing and linker amplification protocols) enhance our ability to generate quantitatively representative metagenomic datasets from low-input DNA samples. Such datasets are already providing new insights into the role of viruses in marine systems and will continue to do so as new environments are explored and synergies and paradigms emerge from large-scale comparative analyses.

  10. Does denitrification occur within porous carbonate sand grains?

    Directory of Open Access Journals (Sweden)

    P. L. M. Cook

    2017-09-01

    Full Text Available Permeable carbonate sands form a major habitat type on coral reefs and play a major role in organic matter recycling. Nitrogen cycling within these sediments is likely to play a major role in coral reef productivity, yet it remains poorly studied. Here, we used flow-through reactors and stirred reactors to quantify potential rates of denitrification and the dependence of denitrification on oxygen concentrations in permeable carbonate sands at three sites on Heron Island, Australia. Our results showed that potential rates of denitrification fell within the range of 2–28 µmol L−1 sediment h−1 and were very low compared to oxygen consumption rates, consistent with previous studies of silicate sands. Denitrification was observed to commence at porewater oxygen concentrations as high as 50 µM in stirred reactor experiments on the coarse sediment fraction (2–10 mm and at oxygen concentrations of 10–20 µM in flow-through and stirred reactor experiments at a site with a median sediment grain size of 0.9 mm. No denitrification was detected in sediments under oxic conditions from another site with finer sediment (median grain size: 0.7 mm. We interpret these results as confirmation that denitrification may occur within anoxic microniches present within porous carbonate sand grains. The occurrence of such microniches has the potential to enhance denitrification rates within carbonate sediments; however further work is required to elucidate the extent and ecological significance of this effect.

  11. Neurobiology of mammalian olfactory learning that occurs during sensitive periods

    Directory of Open Access Journals (Sweden)

    Hideto KABA

    2010-12-01

    Full Text Available This review examines the organizational principles underlying olfactory learning in three specialized contexts that occur during sensitive periods of enhanced neural plasticity and emphasizes some of their common features. All three forms of olfactory learning are associated with neural changes in the olfactory bulb (OB at the first stage of sensory processing. These changes require the association of the olfactory and somatosensory signals in the OB. They all depend on somatosensory stimulation-induced release of noradrenaline that induces structural and functional changes at mitral-granule cell reciprocal synapses in the OB, resulting in increases in inhibitory transmission. In the accessory olfactory bulb, this represents the enhanced self-inhibition of mitral cells, which selectively disrupts the transmission of the mating male’s pregnancy-blocking signal at this level. In contrast, an extensive network of secondary dendrites of mitral cells in the main olfactory bulb probably results in a sharpening of the odor-induced pattern of activity, due to increases in lateral inhibition, leading to offspring recognition in sheep and neonatal learning in rats and rabbits. These findings show that inhibitory interneurons play a critical role in olfactory learning. Further work on how these neurons shape olfactory circuit function could provide important clues to understand memory functions of interneurons in other systems. Moreover, recent research has suggested that three forms of olfactory learning are controlled by synergistic, redundant, and distributed neural mechanisms. This has general implications regarding the mechanisms that may contribute to the robustness of memories [Current Zoology 56 (6: 819–833, 2010].

  12. Kidney Damage in Hemorrhagic Vasculitis Occurring in Childhood and Adulthood

    Directory of Open Access Journals (Sweden)

    O.V. Syniachenko

    2016-12-01

    Full Text Available Introduction. Nephropathy is diagnosed in 30–60 % of patients with hemorrhagic vasculitis (HV (Schönlein Henoch puprupa and occurred in each fourth of them in the onset of the disease and with the same incidence at first recurrence of the patho­logical process. In recent years, the relative and absolute number of patients with this form of glomerular disease significantly increased. According to the results of the kidney biopsy in children, Henoch glomerulonephritis (HGN is the most common variant of the secondary immunoglobulin (Ig A nephritis. The nature of the clinical course and morphological manifestations of the HGN in patients with HV, which began in childhood and adulthood, remains unexplored. This was the purpose and objectives of this study. Materials and methods. The study included 174 patients with HV (83 % of men and 47 % of women. In 92 cases, vasculitis debuted in children (on average in 12 years, and in 82 — in the adults (on average in 25 years. I, II and III degree of activity of pathological process are set at a ratio of 1 : 2 : 2. Seropositivity for high levels of IgA occurred in 40 % of cases, by the presence of rheumatoid factor — in 27 %. At the time of the survey, cutaneous syndrome was diagnosed in 68 % of patients in the form of urticarial, hemorrhagic, papule-nodular, papule-necro­tic, pustular-ulcerative, necrotic-ulcerative, nodose-ulcerative and polymorphic forms, and articular syndrome — in 48 %. In 24 cases, kidney biopsy was performed. Results. Renal disease was revealed in 71 % of patients with HV, while on the background of nephropathy the integral index of the severity of extrarenal patho­logy was significantly higher. According to the characteristics of the articular syndrome, patients with nephropathy and without it differed little among themselves. The severity of muscle syndrome has the impact on the development of the HV. In turn, renal pathology significantly influenced the development

  13. Laser-surface interactions

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    This book is about the interaction of laser radiation with various surfaces at variable parameters of radiation. As a basic principle of classification we chose the energetic or intensity level of interaction of laser radiation with the surfaces. These two characteristics of laser radiation are the most important parameters defining entire spectrum of the processes occurring on the surfaces during interaction with electromagnetic waves. This is a first book containing a whole spectrum of the laser-surface interactions distinguished by the ranges of used laser intensity. It combines the surface response starting from extremely weak laser intensities (~1 W cm-2) up to the relativistic intensities (~1020 W cm-2 and higher). The book provides the basic information about lasers and acquaints the reader with both common applications of laser-surface interactions (laser-related printers, scanners, barcode readers, discs, material processing, military, holography, medicine, etc) and unusual uses of the processes on t...

  14. Diachronic Perspective and Interaction

    DEFF Research Database (Denmark)

    Marchetti, Emanuela; Valente, Andrea

    . Although this interaction style may appeal to teachers, as it reminds of school teaching, it has several disadvantages: a dialogue never occurs between adults and children, who listen in silence, hence it becomes hard to evaluate what has being learnt and how deeply, and finally it is not very engaging...

  15. Does egg competition occur in marine broadcast-spawners?

    Science.gov (United States)

    Marshall, D J; Evans, J P

    2005-09-01

    When the availability of sperm limits female reproductive success, competition for sperm, may be an important broker of sexual selection. This is because sperm limitation can increase the variance in female reproductive success, resulting in strong selection on females to compete for limited fertilization opportunities. Sperm limitation is probably common in broadcast-spawning marine invertebrates, making these excellent candidates for investigating scramble competition between broods of eggs and its consequences for female reproductive success. Here, we report our findings from a series of experiments that investigate egg competition in the sessile, broadcast-spawning polychaete Galeolaria caespitosa. We initially tested whether the order in which eggs encounter sperm affects their fertilization success at two ecologically relevant current regimes. We used a split-clutch-split--ejaculate technique to compare the fertilization success of eggs from individual females that had either first access (competition-free treatment) or second access (egg competition treatment) to a batch of sperm. We found that fertilization success depended on the order in which eggs accessed sperm; eggs that were assigned to the competition-free treatment exhibited significantly higher fertilization rates than those assigned to the egg competition treatment at both current speeds. In subsequent experiments we found that prior exposure of sperm to eggs significantly reduced both the quantity and quality of sperm available to fertilize a second clutch of eggs, resulting in reductions in fertilization success at high and low sperm concentrations. These findings suggest that female traits that increase the likelihood of sperm-egg interactions (e.g. egg size) will respond to selection imposed by egg competition.

  16. Committed effective dose from naturally occuring radionuclides in shellfish

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D. A.

    2013-07-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238U (226Ra), 232Th (228Ra) and 40K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg-1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg-1. The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg-1 for 238U (226Ra), 0.16 Bq kg-1 for 232Th (228Ra) and 18 Bq kg-1 for 40K; the respective daily intake values from crustaceans are 0.36 Bq kg-1, 0.16 Bq kg-1 and 23 Bq kg-1. Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226Ra, 19.3 to 39.1 μSv for 228Ra and 17.0 to 40.4 μSv for 40K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values.

  17. Manufactured Home Testing in Simulated and Naturally Occurring High Winds

    Energy Technology Data Exchange (ETDEWEB)

    W. D. Richins; T. K. Larson

    2006-08-01

    A typical double-wide manufactured home was tested in simulated and naturally occurring high winds to understand structural behavior and improve performance during severe windstorms. Seven (7) lateral load tests were conducted on a double-wide manufactured home at a remote field test site in Wyoming. An extensive instrumentation package monitored the overall behavior of the home and collected data vital to validating computational software for the manufactured housing industry. The tests were designed to approach the design load of the home without causing structural damage, thus allowing the behavior of the home to be accessed when the home was later exposed to high winds (to 80-mph). The data generally show near-linear initial system response with significant non-linear behavior as the applied loads increase. Load transfer across the marriage line is primarily compression. Racking, while present, is very small. Interface slip and shear displacement along the marriage line are nearly insignificant. Horizontal global displacements reached 0.6 inch. These tests were designed primarily to collect data necessary to calibrate a desktop analysis and design software tool, MHTool, under development at the Idaho National Laboratory specifically for manufactured housing. Currently available analysis tools are, for the most part, based on methods developed for “stick built” structures and are inappropriate for manufactured homes. The special materials utilized in manufactured homes, such as rigid adhesives used in the connection of the sheathing materials to the studs, significantly alter the behavior of manufactured homes under lateral loads. Previous full scale tests of laterally loaded manufactured homes confirm the contention that conventional analysis methods are not applicable. System behavior dominates the structural action of manufactured homes and its prediction requires a three dimensional analysis of the complete unit, including tiedowns. This project was

  18. Intraclonal mating occurs during tsetse transmission of Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Ferris Vanessa

    2009-09-01

    that many recombinants are non-viable after intraclonal mating. Conclusion We have demonstrated intraclonal mating during fly transmission of T. b. brucei, contrary to previous findings that recombination occurs only when another strain is present. It is thus no longer possible to assume that T. b. brucei remains genetically unaltered after fly transmission.

  19. Changes in the body posture of women occurring with age.

    Science.gov (United States)

    Drzał-Grabiec, Justyna; Snela, Sławomir; Rykała, Justyna; Podgórska, Justyna; Banaś, Agnieszka

    2013-10-12

    A current topic in the field of geriatrics still needing a great deal of study is the changes in body posture occurring with age. Symptoms of these changes can be observed starting between the ages of 40-50 years with a slow progression that increases after 60 years of age. The aims of this study were to evaluate parameters characterizing the posture of women over the age of 60 years compared with a control group and to determine the dynamics of body posture changes in the following decades. The study included 260 randomly selected women. The study group consisted of 130 women between the ages of 60-90 years (Older Women). The control group (Younger Women) consisted of 130 women between the ages of 20-25 years (posture stabilization period). The photogrammetric method was used to evaluate body posture using the phenomenon of the projection chamber. The study was conducted according to generally accepted principles. In the analysis of parameters characterizing individual slope curves, results were varied among different age groups. The lumbar spine slope did not show significant differences between different age groups (p = 0.6952), while statistically significant differences (p = 0.0000) were found in the thoracic-lumbar spine slope (p = 0.0033) and upper thoracic spine slope. Body angle was shown to increase with age (p = 0.0000). Thoracic kyphosis depth significantly deepened with age (p = 0.0002), however, the thoracic kyphosis angle decreased with age (p = 0.0000). An increase in asymmetries was noticed, provided by a significantly higher angle of the shoulder line (p = 0.0199) and the difference in height of the lower shoulder blade angle (p = 0.0007) measurements in the group of older women. Changes in the parameters describing body posture throughout consecutive decades were observed. Therapy for women over the age of 60 years should involve strengthening of the erector spinae muscles and controlling body posture with the aim of reducing trunk inclination

  20. Myofascial force transmission via extramuscular pathways occurs between antagonistic muscles.

    Science.gov (United States)

    Huijing, Peter A; Baan, Guus C

    2008-01-01

    distributions of sarcomere lengths that are consequences of such interaction. If this is done properly, the effects of integrating a muscle fibre, muscle or muscle group into higher levels of organisation of the body will be evident.

  1. Mediated Interactions and Musical Expression - A Survey

    NARCIS (Netherlands)

    Reidsma, Dennis; Radha, Mustafa; Nijholt, Antinus; Lee, Newton

    2014-01-01

    This chapter surveys the field of technologically mediated musical interaction and technologically enhanced musical expression. We look at several new technologies that enable new ways of musical expression and interaction, explore the micro-coordination that occurs in collaborative musical

  2. [Diagnosis of osteoporosis occurring in autoimmune thyroid gland disease].

    Science.gov (United States)

    Radojković, Ivan; Radojković, Jana; Djurica, Snezana

    2005-10-01

    Osteoporosis or porotic bone is a general, systemic bone disease, which is manifested by fracture as its consequence. The main characteristic of this disease is the loss of bone microarchitecture, bone mass reduction, and its increased fragility. The result, thereof, is susceptibility to fracture. Etiology of osteoporosis is polymorph. Its socio-medical importance is enormous, since there is one osteoporotic fracture every 20 sec. worldwide. Million and six hundred thousand osteoporotic fractures occur annualy throughout the world. Thyroid gland is susceptible to autoimmune reactions that lead to autoimmune diseases, just like many other organs. The autoimmune disorder is a final consequence of a failure, in some instance, within the crucial mechanism of regulation of self tissue tolerance. The main goal is to prove the presence of osteoporosis, its inexpensive and quick diagnostics; to make a distinction among the causes that lead to it. In addition, to indicate the importance of osteoporosis that is caused by normal, metabolic processes which are an inevitable part of ageing. Diagnosis of osteoporosis can be done through laboratory, which is a tiresome, time consuming task. Measurements of BMD could be also performed by using new devices. Osteometers could be constructed on the basis of X-ray photon energy or US. Utilization most contemporary one uses laser beam, and it approximates the distance of additional tissue that also absorbs part of energy changing absorption of the reception unit and thus making the measurement results accurate. In diagnosing BMD by osteometer, one faces with certain difficulties. When axial quantitative CT is used, the value may be falsely lower, because of the loss of energy absorbed by aorta which is often calcified in elderly people. In devices with transversal scanning, of the same nature and technology, a part of the energy is being absorbed by transversal and spinal vertebrals. After the research, one may conclude that the most

  3. Infrared monitoring of hydrothermal echanges occurring in a fracture

    Science.gov (United States)

    Neuville, Amélie; Flekkøy, Eirik; Galland, Olivier; Gundersen, Olav; Jørgen Måløy, Knut

    2014-05-01

    We aim to characterize the heat exchange that occurs when water flows through a fracture at a different temperature from that of the surrounding rock. This happens during many man-made or natural processes. For instance, injection of water in the context of geothermal power plants or sudden mechanical movements (e.g. rockfalls, landslides, earthquakes) that transport water. It is presently challenging to estimate the heat transfer and temperature inside a fractured medium where water is flowing, despite various numerical models which have been proposed [Neuville et al, 2010, 2013; Kolditz et Clauser, 1998; Heuer, 1991]. The difficulties arise from the complexity of the fracture network, the fracture topography, as well as complex hydraulic flow (e.g. recirculation) and heat exchanges. As a consequence, various hypotheses were made in the models. More experimental data are required in order to calibrate these models, validate or refute the hypotheses. Our work aims to provide temperature data at the fracture scale, in an experiment where the pressure gradient an fracture topography are controlled, with slow hydraulic flow. This required to develop a setup from scratch. An infrared camera and thermistors are used to monitor the temperature in space and time. Water is injected through a partly natural rough fracture with impermeable walls. The bottom part of the fracture is a larvikite stone with a rough surface (presumably this surface was obtained from mode I fracturing), and the top part is a layer which is transparent in the infrared range. As a consequence the infrared camera is expected to measure the temperature at the interface between this transparent layer and the water. The topography of the surface of the rock was reconstituted using a photogrammetry software [MicMac, IGN], and compared to measurements made with a mechanical profiler. Using this geometry we carefully localize the temperature observations (infrared camera and thermistors) and correlate the

  4. Avoided criticality in near-optimally doped high-temperature superconductors

    Science.gov (United States)

    Haule, Kristjan; Kotliar, Gabriel

    2007-09-01

    We study the crossover from the underdoped to the overdoped regime of the t-J model within a plaquette dynamical mean field approach. We find that the shortest electron lifetime occurs near optimal doping where the superconducting critical temperature is maximal. The mean field theory provides a simple physical picture of this effect. In the underdoped regime, the charge carriers propagate coherently among spin singlets, formed by the superexchange interaction. In the overdoped, large carrier concentration regime, the Kondo effect dominates resulting in spin-charge composite quasiparticles which are also coherent. Separating these two Fermi liquid regimes, there is a critical doping where the superexchange and the Kondo interaction balance each other. At this point, the normal phase is highly incoherent and the optical conductivity exhibits power law behavior at intermediate frequencies. The onset of superconductivity restores coherence, causing the appearance of a resonance in the spin channel.

  5. Food-Drug Interactions

    Directory of Open Access Journals (Sweden)

    Arshad Yar Khan

    2011-03-01

    Full Text Available The effect of drug on a person may be different than expected because that drug interacts with another drug the person is taking (drug-drug interaction, food, beverages, dietary supplements the person is consuming (drug-nutrient/food interaction or another disease the person has (drug-disease interaction. A drug interaction is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on its own. These interactions may occur out of accidental misuse or due to lack of knowledge about the active ingredients involved in the relevant substances. Regarding food-drug interactions physicians and pharmacists recognize that some foods and drugs, when taken simultaneously, can alter the body's ability to utilize a particular food or drug, or cause serious side effects. Clinically significant drug interactions, which pose potential harm to the patient, may result from changes in pharmaceutical, pharmacokinetic, or pharmacodynamic properties. Some may be taken advantage of, to the benefit of patients, but more commonly drug interactions result in adverse drug events. Therefore it is advisable for patients to follow the physician and doctors instructions to obtain maximum benefits with least fooddrug interactions. The literature survey was conducted by extracting data from different review and original articles on general or specific drug interactions with food. This review gives information about various interactions between different foods and drugs and will help physicians and pharmacists prescribe drugs cautiously with only suitable food supplement to get maximum benefit for the patient.

  6. Spectral analysis of naturally occurring methylxanthines (theophylline, theobromine and caffeine) binding with DNA.

    Science.gov (United States)

    Johnson, Irudayam Maria; Prakash, Halan; Prathiba, Jeyaguru; Raghunathan, Raghavachary; Malathi, Raghunathan

    2012-01-01

    Nucleic acids exist in a dynamic equilibrium with a number of molecules that constantly interact with them and regulate the cellular activities. The inherent nature of the structure and conformational integrity of these macromolecules can lead to altered biological activity through proper targeting of nucleic acids binding ligands or drug molecules. We studied the interaction of naturally occurring methylxanthines such as theophylline, theobromine and caffeine with DNA, using UV absorption and Fourier transform infrared (FTIR) spectroscopic methods, and especially monitored their binding affinity in the presence of Mg(2+) and during helix-coil transitions of DNA by temperature (T(m)) or pH melting profiles. The study indicates that all these molecules effectively bind to DNA in a dose dependent manner. The overall binding constants of DNA-theophylline = 3.5×10(3) M(-1), DNA-theobromine = 1.1×10(3) M(-1), and DNA-Caffeine = 3.8×10(3) M(-1). On the other hand T(m)/pH melting profiles showed 24-35% of enhanced binding activity of methylxanthines during helix-coil transitions of DNA rather than to its native double helical structure. The FTIR analysis divulged that theophylline, theobromine and caffeine interact with all the base pairs of DNA (A-T; G-C) and phosphate group through hydrogen bond (H-bond) interaction. In the presence of Mg(2+), methylxanthines altered the structure of DNA from B to A-family. However, the B-family structure of DNA remained unaltered in DNA-methylxanthines complexes or in the absence of Mg(2+). The spectral analyses indicated the order of binding affinity as "caffeine≥theophylline>theobromine" to the native double helical DNA, and "theophylline≥theobromine>caffeine to the denatured form of DNA and in the presence of divalent metal ions.

  7. Spectral analysis of naturally occurring methylxanthines (theophylline, theobromine and caffeine binding with DNA.

    Directory of Open Access Journals (Sweden)

    Irudayam Maria Johnson

    Full Text Available Nucleic acids exist in a dynamic equilibrium with a number of molecules that constantly interact with them and regulate the cellular activities. The inherent nature of the structure and conformational integrity of these macromolecules can lead to altered biological activity through proper targeting of nucleic acids binding ligands or drug molecules. We studied the interaction of naturally occurring methylxanthines such as theophylline, theobromine and caffeine with DNA, using UV absorption and Fourier transform infrared (FTIR spectroscopic methods, and especially monitored their binding affinity in the presence of Mg(2+ and during helix-coil transitions of DNA by temperature (T(m or pH melting profiles. The study indicates that all these molecules effectively bind to DNA in a dose dependent manner. The overall binding constants of DNA-theophylline = 3.5×10(3 M(-1, DNA-theobromine = 1.1×10(3 M(-1, and DNA-Caffeine = 3.8×10(3 M(-1. On the other hand T(m/pH melting profiles showed 24-35% of enhanced binding activity of methylxanthines during helix-coil transitions of DNA rather than to its native double helical structure. The FTIR analysis divulged that theophylline, theobromine and caffeine interact with all the base pairs of DNA (A-T; G-C and phosphate group through hydrogen bond (H-bond interaction. In the presence of Mg(2+, methylxanthines altered the structure of DNA from B to A-family. However, the B-family structure of DNA remained unaltered in DNA-methylxanthines complexes or in the absence of Mg(2+. The spectral analyses indicated the order of binding affinity as "caffeine≥theophylline>theobromine" to the native double helical DNA, and "theophylline≥theobromine>caffeine to the denatured form of DNA and in the presence of divalent metal ions.

  8. Facilitative root interactions in intercrops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Jensen, E.S.

    2005-01-01

    Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We discuss examples of facilitative root interactions in intercropped agroecosystems; including...... intensified cropping systems using chemical and mechanical inputs also show that facilitative interactions definitely can be of significance. It is concluded that a better understanding of the mechanisms behind facilitative interactions may allow us to benefit more from these phenomena in agriculture...

  9. Selection on Mitochondrial Variants Occurs between and within Individuals in an Expanding Invasion.

    Science.gov (United States)

    Rollins, Lee A; Woolnough, Andrew P; Fanson, Benjamin G; Cummins, Michelle L; Crowley, Tamsyn M; Wilton, Alan N; Sinclair, Ron; Butler, Ashleigh; Sherwin, William B

    2016-04-01

    Mitochondria are critical for life, yet their underlying evolutionary biology is poorly understood. In particular, little is known about interaction between two levels of evolution: between individuals and within individuals (competition between cells, mitochondria or mitochondrial DNA molecules). Rapid evolution is suspected to occur frequently in mitochondrial DNA, whose maternal inheritance predisposes advantageous mutations to sweep rapidly though populations. Rapid evolution is also predicted in response to changed selection regimes after species invasion or removal of pathogens or competitors. Here, using empirical and simulated data from a model invasive bird species, we provide the first demonstration of rapid selection on the mitochondrial genome within individuals in the wild. Further, we show differences in mitochondrial DNA copy number associated with competing genetic variants, which may provide a mechanism for selection. We provide evidence for three rarely documented phenomena: selection associated with mitochondrial DNA abundance, selection on the mitochondrial control region, and contemporary selection during invasion.

  10. Drug-drug interactions between rosuvastatin and oral antidiabetic drugs occurring at the level of oatp1b1s

    NARCIS (Netherlands)

    Steeg, E. van de; Greupink, R.; Schreurs, M.; Nooijen, I.H.G.; Verhoeck, K.C.M.; Hanemaaijer, R.; Ripken, D.; Monshouwer, M.; Vlaming, M.L.H.; DeGroot, J.; Verwei, M.; Russel, F.G.M.; Huisman, M.T.; Wortelboer, H.M.

    2013-01-01

    Organic anion-transporting polypeptide 1B1 (OATP1B1) is an important hepatic uptake transporter, of which the polymorphic variant OATP1B1*15 (Asn130Asp and Val174Ala) has been associated with decreased transport activity. Rosuvastatin is an OATP1B1 substrate and often concomitantly prescribed with o

  11. Theoretical Studies Relating to the Interaction of Radiation with Matter: Atomic Collision Processes Occurring in the Presence of Radiation Fields.

    Science.gov (United States)

    1980-10-01

    StellarAtmospheres (Freeman, San Fran- L. Allen, J. Phys. B 11, 3023 (1978). cisco, 1970), Chap. 10. IlJ. C. Gay and W. B. Schneider, Z. Phys. A 278, 211...tho difficulty of di.ver- with .gence. ~- ~ ~ R C.)~A) 6 -1I cosm 3n 7 and E (.. (G. 10) leads to the total exAcitation Cross- wherec v is the active

  12. Theoretical Studies Relating to the Interaction of Radiation with Matter: Atomic Collision Processes Occurring in the Presence of Radiation Fields.

    Science.gov (United States)

    1982-09-15

    kb/)- 𔃻 << I , 12See, e.g., M. S. Child , Molecular Collision Theory (Academic, London, 1974), Chaps. I -S. where the first inequality follows from...3.24) I(3.21b) rf, (k) f d 2 k~rO,(k)o,,2i) .(3.2S) With va locity changing collisions negletted . ph is i he tradi- 9n *V ph tion-1 v.. the collision...as I’M. S. Child , Molecular Collision Theory (Academic, the Internal momentum is linked to the Internuclear London, 1974). Note we follow the notation

  13. Neuronal differentiation and synapse formation occur in space and time with fractal dimension.

    Science.gov (United States)

    Waliszewski, Przemyslaw; Konarski, Jerzy

    2002-03-15

    The analysis of a set of experimental data obtained by an independent team of researchers confirms that neuronal differentiation or synapse formation do occur in time and space with fractal dimension. The interacting cells create first a dynamic system with its own attractor, (i.e., a fragment of time and space where the dynamic processes occur and where no further evolution of the system is possible at all owing to the action of the intrasystemic forces unless some extrasystemic forces act upon it). This attractor is then modified in the active manner by the differentiating cells until the system attains a degenerated stationary state and differentiation ends. The fractal structure of the system is also lost in the course of tumor progression. Our data indicate that the cellular system can attain the degenerated stationary state, leaving the attractor with a fractal dimension directly or undergoing diversification into many attractors and going through the areas of deterministic chaos. Since evolution of the cellular system is driven by the cooperative dynamic processes, as reflected by the changes of the mean fractal dimension between the intervals of the Gompertzian curve, it is likely that cells differentiate into neurons and create synapses with a conjugated probability and non-Gaussian distribution rather than with the classical probability and the Gaussian distribution. These findings can help to optimize features of artificial neural networks. They also define a simple in vitro biological model for biophysical and biochemical studies on natural neural networks.

  14. Static and dynamic properties of interacting spin-1 bosons in an optical lattice

    Science.gov (United States)

    Natu, Stefan S.; Pixley, J. H.; Das Sarma, S.

    2015-04-01

    We study the physics of interacting spin-1 bosons in an optical lattice using a variational Gutzwiller technique. We compute the mean-field ground state wave function and discuss the evolution of the condensate, spin, nematic, and singlet order parameters across the superfluid-Mott transition. We then extend the Gutzwiller method to derive the equations governing the dynamics of low energy excitations in the lattice. Linearizing these equations, we compute the excitation spectra in the superfluid and Mott phases for both ferromagnetic and antiferromagnetic spin-spin interactions. In the superfluid phase, we recover the known excitation spectrum obtained from Bogoliubov theory. In the nematic Mott phase, we obtain gapped, quadratically dispersing particle and hole-like collective modes, whereas in the singlet Mott phase, we obtain a nondispersive gapped mode, corresponding to the breaking of a singlet pair. For the ferromagnetic Mott insulator, the Gutzwiller mean-field theory only yields particle-hole-like modes but no Goldstone mode associated with long-range spin order. To overcome this limitation, we supplement the Gutzwiller theory with a Schwinger boson mean-field theory which captures superexchange-driven fluctuations. In addition to the gapped particle-hole-like modes, we obtain a gapless quadratically dispersing ferromagnetic spin-wave Goldstone mode. We discuss the evolution of the singlet gap, particle-hole gap, and the effective mass of the ferromagnetic Goldstone mode as the superfluid-Mott phase boundary is approached from the insulating side. We discuss the relevance and validity of Gutzwiller mean-field theories to spinful systems, and potential extensions of this framework to include more exotic physics which appears in the presence of spin-orbit coupling or artificial gauge fields.

  15. Explicit Interaction

    DEFF Research Database (Denmark)

    Löwgren, Jonas; Eriksen, Mette Agger; Linde, Per

    2006-01-01

    as an interpretation of palpability, comprising usability as well as patient empowerment and socially performative issues. We present a prototype environment for video recording during physiotherapeutical consultation which illustrates our current thoughts on explicit interaction and serves as material for further......We report an ongoing study of palpable computing to support surgical rehabilitation, in the general field of interaction design for ubiquitous computing. Through explorative design, fieldwork and participatory design techniques, we explore the design principle of explicit interaction...

  16. Floor interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Ludvigsen, Martin;

    2005-01-01

    Within architecture, there is a long tradition of careful design of floors. The design has been concerned with both decorating floors and designing floors to carry information. Ubiquitous computing technology offers new opportunities for designing interactive floors. This paper presents three...... different interactive floor concepts. Through an urban perspective it draws upon the experiences of floors in architecture, and provides a set of design issues for designing interactive floors....

  17. Playful Interaction

    DEFF Research Database (Denmark)

    2003-01-01

    The video Playful Interaction describes a future architectural office, and envisions ideas and concepts for playful interactions between people, materials and appliances in a pervasive and augmented working environment. The video both describes existing developments, technologies and designs...... as well as ideas not yet implemented such as playful modes of interaction with an augmented ball. Playful Interaction has been used as a hybrid of a vision video and a video prototype (1). Externally the video has been used to visualising our new ideas, and internally the video has also worked to inspire...

  18. Transition Metal Donor-Peptide-Acceptor Complexes: From Intramolecular Electron Transfer Reactions to the Study of Reactive Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Isied, Stephan S.

    2003-03-11

    The trans-polyproline (PII) oligomers (Figure 1) are unusually rigid peptide structures which have been extensively studied by our group for peptide mediated intramolecular electron transfer (ET) at long distances. We have previously studied ET across a series of metal ion donor (D) acceptor (A) oligoproline peptides with different distances, driving forces and reorganizational energies. The majority of these experiments involve generating the ET intermediate using pulse radiolysis methods, although more recently photochemical methods are also used. Results of these studies showed that ET across peptides can vary by more than twelve orders of magnitude. Using ruthenium bipyridine donors, ET reaction rate constants across several proline residues (n = 4 - 9) occurred in the millisecond (ms) to {micro}s timescale, thus limiting the proline peptide conformational motions to only minor changes (far smaller than the large changes that occur on the ms to sec timescale, such as trans to cis proline isomerization). The present report describes our large data base of experimental results for D-peptide-A complexes in terms of a model where the involvement of both superexchange and hopping (hole and electron) mechanisms account for the long range ET rate constants observed. Our data shows that the change from superexchange to hopping mechanisms occurs at different distances depending on the type of D and A and their interactions with the peptides. Our model is also consistent with generalized models for superexchange and hopping which have been put forward by a number of theoretical groups to account for long range ET phenomena.

  19. Aesthetic interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Iversen, Ole Sejer; Krogh, Peter;

    2004-01-01

    There is a growing interest in considering aesthetic aspects in the design of interactive systems. A set of approaches are emerging each representing different applications of the terminology as well as different inherent assumptions on the role of the user, designer and interaction ideals....... In this paper, we use the concept of Pragmatist Aesthetics to provide a framework for distinguishing between different approaches to aesthetics. Moreover, we use our own design cases to illustrate how pragmatist aesthetics is a promising path to follow in the context of designing interactive systems......, as it promotes aesthetics of use, rather than aesthetics of appearance. We coin this approach in the perspective of aesthetic interaction. Finally we make the point that aesthetics is not re-defining everything known about interactive systems. We provide a framework placing this perspective among other...

  20. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2012-01-01

    Ready to create rich interactive experiences with your artwork, designs, or prototypes? This is the ideal place to start. With this hands-on guide, you'll explore several themes in interactive art and design-including 3D graphics, sound, physical interaction, computer vision, and geolocation-and learn the basic programming and electronics concepts you need to implement them. No previous experience is necessary. You'll get a complete introduction to three free tools created specifically for artists and designers: the Processing programming language, the Arduino microcontroller, and the openFr

  1. Naturally occurring mentoring in Japan and the United States: social roles and correlates.

    Science.gov (United States)

    Darling, Nancy; Hamilton, Stephen; Toyokawa, Teru; Matsuda, Sei

    2002-04-01

    Although the word "mentor"has traditionally been used to describe a relationship between an older adult and a younger person, recent work has extended its usage to relationships with peers and groups rather than with individuals and uncoupled the instrumental and affective qualities of the role. This paper examines (a) the extent to which adolescents' relationships with significant others in different social roles are characterized by mentoring and (b) the extent to which mentoring and other relationship functions covary. Adolescents' naturally occurring social relationships are explored in two very different contexts-Japan and the United States-that differ in the norms and patterning of social interactions. College students (N = 365) used questionnaires to describe the extent to which relations with significant others were characterized by mentoring. Results indicate striking similarity in the patterning of results in the two countries and support the traditional view of mentoring. Mentoring is most likely to occur in relationships with adults (especially parents), rather than with peers, and with same-gender, rather than other-gender associates. Mentoring by parents appears to covary with other aspects of positive relationships, but be more independent in relationships with unrelated adults or peers. Although more of the variability in experienced mentoring is attributed to differences between associates than to differences between adolescents in both the United States and Japan, this is especially true of the United States. Results suggest that although "classic" mentoring is most common in both countries, mentoring is somewhat less constrained by social role differences in Japan than is in the United States.

  2. Bordetella pertussis naturally occurring isolates with altered lipooligosaccharide structure fail to fully mature human dendritic cells.

    Science.gov (United States)

    Brummelman, Jolanda; Veerman, Rosanne E; Hamstra, Hendrik Jan; Deuss, Anna J M; Schuijt, Tim J; Sloots, Arjen; Kuipers, Betsy; van Els, Cécile A C M; van der Ley, Peter; Mooi, Frits R; Han, Wanda G H; Pinelli, Elena

    2015-01-01

    Bordetella pertussis is a Gram-negative bacterium and the causative agent of whooping cough. Despite high vaccination coverage, outbreaks are being increasingly reported worldwide. Possible explanations include adaptation of this pathogen, which may interfere with recognition by the innate immune system. Here, we describe innate immune recognition and responses to different B. pertussis clinical isolates. By using HEK-Blue cells transfected with different pattern recognition receptors, we found that 3 out of 19 clinical isolates failed to activate Toll-like receptor 4 (TLR4). These findings were confirmed by using the monocytic MM6 cell line. Although incubation with high concentrations of these 3 strains resulted in significant activation of the MM6 cells, it was found to occur mainly through interaction with TLR2 and not through TLR4. When using live bacteria, these 3 strains also failed to activate TLR4 on HEK-Blue cells, and activation of MM6 cells or human monocyte-derived dendritic cells was significantly lower than activation induced by the other 16 strains. Mass spectrum analysis of the lipid A moieties from these 3 strains indicated an altered structure of this molecule. Gene sequence analysis revealed mutations in genes involved in lipid A synthesis. Findings from this study indicate that B. pertussis isolates that do not activate TLR4 occur naturally and that this phenotype may give this bacterium an advantage in tempering the innate immune response and establishing infection. Knowledge on the strategies used by this pathogen in evading the host immune response is essential for the improvement of current vaccines or for the development of new ones.

  3. Embarrassing Interactions

    DEFF Research Database (Denmark)

    Deterding, Sebastian; Lucero, Andrés; Holopainen, Jussi;

    2015-01-01

    Wherever the rapid evolution of interactive technologies disrupts standing situational norms, creates new, often unclear situational audiences, or crosses cultural boundaries, embarrassment is likely. This makes embarrassment a fundamental adoption and engagement hurdle, but also a creative design...

  4. Interaction graphs

    DEFF Research Database (Denmark)

    Seiller, Thomas

    2016-01-01

    Interaction graphs were introduced as a general, uniform, construction of dynamic models of linear logic, encompassing all Geometry of Interaction (GoI) constructions introduced so far. This series of work was inspired from Girard's hyperfinite GoI, and develops a quantitative approach that should...... be understood as a dynamic version of weighted relational models. Until now, the interaction graphs framework has been shown to deal with exponentials for the constrained system ELL (Elementary Linear Logic) while keeping its quantitative aspect. Adapting older constructions by Girard, one can clearly define...... "full" exponentials, but at the cost of these quantitative features. We show here that allowing interpretations of proofs to use continuous (yet finite in a measure-theoretic sense) sets of states, as opposed to earlier Interaction Graphs constructions were these sets of states were discrete (and finite...

  5. Neutrino Interactions

    CERN Document Server

    McFarland, Kevin

    2008-01-01

    This manuscript summarizes a series of three lectures on interactions of neutrinos . The lectures begin with a pedagogical foundation and then explore topics of interest to current and future neutrino oscillation and cross-section experiments.

  6. Interactive Workspaces

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst

    augmented reality, interactive building elements, and mobile devices to support new ways of working in a diversity of application domains with work situations ranging from individual work, through local collaboration, to distributed collaboration. The work situations may take place in offices/project rooms...... or in the field. The types of tasks may range from adhoc to more planned forms of interaction. We involve users from specific application domains and use settings continuously in our research following a participatory design approach....

  7. Exchange interactions in the perovskites Ca1-xSrxMnO3 and RMnO3 (R=La,Pr,Sm)

    Science.gov (United States)

    Zhou, J.-S.; Goodenough, J. B.

    2003-08-01

    Measurement of the variation of the Néel temperature TN with pressure P and the compressibility κ of the orbitally ordered Mn(III)O3 array of the RMnO3 family (R=La,Pr,Sm) and of the Mn(IV)O3 array of the Ca1-xSrxMnO3 system have enabled the determination for each of a systematic increase in κ, the magnitude of the Bloch parameter αB≡d ln TN/d ln V, and TN with decreasing bending of the (180°-φ) Mn-O-Mn bond angles. The data demonstrate that the anomalously high value of -αB=5.5 reported previously for LaMnO3 is not due to orbital order and its attendant anisotropic magnetic order. A higher |αB| than 3.3 and an increasing compressibility characterize a system on the approach from the localized-electron side to a first-order transition from localized to itinerant electronic behavior. Moreover, the puzzling empirical relationship TN˜ for the π-bonding Mn(IV)O3 array is rationalized by dominance of a semicovalent exchange term over the superexchange term in the perturbation theory for the spin-spin interatomic interactions. The data also provide indirect evidence for a transition from in-phase to out-of-phase stacking along the c axis of the (001)-plane orbital ordering that has been predicted by Mizokawa, Khomskii, and Sawatzky.

  8. Dipicolinic Acid Release by Germinating Clostridium difficile Spores Occurs through a Mechanosensing Mechanism

    Science.gov (United States)

    Francis, Michael B.

    2016-01-01

    ABSTRACT Classically, dormant endospores are defined by their resistance properties, particularly their resistance to heat. Much of the heat resistance is due to the large amount of dipicolinic acid (DPA) stored within the spore core. During spore germination, DPA is released and allows for rehydration of the otherwise-dehydrated core. In Bacillus subtilis, 7 proteins are encoded by the spoVA operon and are important for DPA release. These proteins receive a signal from the activated germinant receptor and release DPA. This DPA activates the cortex lytic enzyme CwlJ, and cortex degradation begins. In Clostridium difficile, spore germination is initiated in response to certain bile acids and amino acids. These bile acids interact with the CspC germinant receptor, which then transfers the signal to the CspB protease. Activated CspB cleaves the cortex lytic enzyme, pro-SleC, to its active form. Subsequently, DPA is released from the core. C. difficile encodes orthologues of spoVAC, spoVAD, and spoVAE. Of these, the B. subtilis SpoVAC protein was shown to be capable of mechanosensing. Because cortex degradation precedes DPA release during C. difficile spore germination (opposite of what occurs in B. subtilis), we hypothesized that cortex degradation would relieve the osmotic constraints placed on the inner spore membrane and permit DPA release. Here, we assayed germination in the presence of osmolytes, and we found that they can delay DPA release from germinating C. difficile spores while still permitting cortex degradation. Together, our results suggest that DPA release during C. difficile spore germination occurs though a mechanosensing mechanism. IMPORTANCE Clostridium difficile is transmitted between hosts in the form of a dormant spore, and germination by C. difficile spores is required to initiate infection, because the toxins that are necessary for disease are not deposited on the spore form. Importantly, the C. difficile spore germination pathway

  9. Three-dimensional magnetic interactions in quasi-two-dimensional PdAs2O6

    Science.gov (United States)

    Zhao, Z. Y.; Wu, Y.; Cao, H. B.; Zhou, H. D.; Yan, J.-Q.

    2017-06-01

    Millimeter-sized PdAs2O6 single crystals are grown using the vapor transport technique. The magnetic order at {{T}\\text{N}}=140 K is studied by measuring magnetic properties, specific heat, and neutron single crystal diffraction. The anisotropic magnetic susceptibility and a metamagnetic transition observed in magnetic fields above 20 kOe suggest that the magnetic moment lies in the ab plane, consistent with the magnetic structure determined by neutron single crystal diffraction. Below 140 K, Pd2+ ions order ferromagnetically in the ab plane but antiferromagnetically along the crystallographic c axis. The ordered moment is refined to be 2.09(2) {μ\\text{B}} /Pd2+ using the fitted magnetic form factor of Pd2+ . A weak λ-type anomaly around T N was observed in specific heat and the magnetic entropy change across T N is 1.72 J mol-1 K.This small entropy change and the temperature dependence of the magnetic susceptibility support the presence of short range correlations in a wide temperature range {{T}\\text{N}} 250 K. The comparison with SrRu2O6 suggests that the magnetic interactions in PdAs2O6 are dominated by Pd-(O-\\text{As}\\text{As} -O)-Pd super-superexchange and three dimensional despite the quasi-two-dimensional arrangement of magnetic ions. The comparison with NiAs2O6 suggests that increasing covalency of isostructural compounds is an effective approach to design and to discover new materials with higher magnetic order temperatures in the localized regime.

  10. Acoustic surface perception from naturally occurring step sounds of a dexterous hexapod robot

    Science.gov (United States)

    Cuneyitoglu Ozkul, Mine; Saranli, Afsar; Yazicioglu, Yigit

    2013-10-01

    Legged robots that exhibit dynamic dexterity naturally interact with the surface to generate complex acoustic signals carrying rich information on the surface as well as the robot platform itself. However, the nature of a legged robot, which is a complex, hybrid dynamic system, renders the more common approach of model-based system identification impractical. The present paper focuses on acoustic surface identification and proposes a non-model-based analysis and classification approach adopted from the speech processing literature. A novel feature set composed of spectral band energies augmented by their vector time derivatives and time-domain averaged zero crossing rate is proposed. Using a multi-dimensional vector classifier, these features carry enough information to accurately classify a range of commonly occurring indoor and outdoor surfaces without using of any mechanical system model. A comparative experimental study is carried out and classification performance and computational complexity are characterized. Different feature combinations, classifiers and changes in critical design parameters are investigated. A realistic and representative acoustic data set is collected with the robot moving at different speeds on a number of surfaces. The study demonstrates promising performance of this non-model-based approach, even in an acoustically uncontrolled environment. The approach also has good chance of performing in real-time.

  11. Mobilization of Phosphorus by Naturally Occurring Organic Acids in Oxisols and Ultisols

    Institute of Scientific and Technical Information of China (English)

    HANXING-GUO; C.F.JORDAN; 等

    1995-01-01

    Citric and malic acids at concentrations of 0.1,1.0,10,and 100 mmol/L were added to three Ultisols and one Oxisol,The amount of P in solution increased with increasing organic acid concentrations,while the amount of Fe-and Al-bound P decreased.This result suggested that naturally occurring products of organicmatter decomposition could increase the P availability to plants in soils where there is a relatively large pool of Fe-and Al-bound P.The interactions between citric and malic acids at the above concentrations,and p added at rates of 10,20,40,and 80mg/kg were determined.At zero levels of organic acids,all added P became either labile or bound ,and greater proportions remained soluble as the concentration of orgaic acids increased,which suggested that organic acids reduced fixation of dissolved P in Fe-and AL-rich soils .Agricultural practices which increase organic matter input on P-deficient acid soild could decrease P deficiency,This would be important in many tropical and subtropical regions where these soils are common,and where the costs of fertilizers and lime are relatively high.

  12. The membrane integration of a naturally occurring alpha-helical hairpin.

    Science.gov (United States)

    Nagy, Akos; Turner, R James

    2007-05-04

    Helical hairpins, two closely spaced helical membrane spanning segments separated by a short surface turn, are thought to be common in integral membrane proteins. Here, we study the membrane integration of a naturally occurring helical hairpin from the secretory Na(+)-K(+)-2Cl(-) cotransporter NKCC1. This sequence is only slightly longer and significantly less hydrophobic than a previously identified minimal poly-leucine model hairpin structure. Using site directed mutagenesis we document the importance of the turn propensity of the amino acids in the intervening surface turn but, somewhat surprisingly, our results indicate that the formation of this natural hairpin apparently does not depend on specific helix-helix interactions. Our results suggest that helical hairpins may be formed quite readily from even minimally hydrophobic sequences separated by a short, sufficiently strong, turn signal, and that current methods for predicting integral membrane protein topology may miss many similar short helical hairpin sequences. Thus the occurrence of these structures may be much more common than presently thought.

  13. Mobilization of arsenic and other naturally occurring contaminants in groundwater of the Main Ethiopian Rift aquifers.

    Science.gov (United States)

    Rango, Tewodros; Vengosh, Avner; Dwyer, Gary; Bianchini, Gianluca

    2013-10-01

    This study investigates the mechanisms of arsenic (As) and other naturally occurring contaminants (F(-), U, V, B, and Mo) mobilization from Quaternary sedimentary aquifers of the Main Ethiopian Rift (MER) and their enrichment in the local groundwater. The study is based on systematic measurements of major and trace elements as well as stable oxygen and hydrogen isotopes in groundwater, coupled with geochemical and mineralogical analyses of the aquifer rocks. The Rift Valley aquifer is composed of rhyolitic volcanics and Quaternary lacustrine sediments. X-ray fluorescence (XRF) results revealed that MER rhyolites (ash, tuff, pumice and ignimbrite) and sediments contain on average 72 wt. % and 65 wt. % SiO2, respectively. Petrographic studies of the rhyolites indicate predominance of volcanic glass, sanidine, pyroxene, Fe-oxides and plagioclase. The As content in the lacustrine sediments (mean = 6.6 mg/kg) was higher than that of the rhyolites (mean: 2.5 mg/kg). The lacustrine aquifers of the Ziway-Shala basin in the northern part of MER were identified as high As risk zones, where mean As concentration in groundwater was 22.4 ± 33.5 (range of 0.60-190 μg/L) and 54% of samples had As above the WHO drinking water guideline value of 10 μg/L. Field As speciation measurements showed that most of the groundwater samples contain predominantly (~80%) arsenate-As(V) over arsenite-As(III) species. The As speciation together with field data of redox potential (mean Eh = +73 ± 65 mV) and dissolved-O2 (6.6 ± 2.2 mg/L) suggest that the aquifer is predominantly oxidative. Water-rock interactions, including the dissolution of volcanic glass produces groundwater with near-neutral to alkaline pH (range 6.9-8.9), predominance of Na-HCO3 ions, and high concentration of SiO2 (mean: 85.8 ± 11.3 mg/L). The groundwater data show high positive correlation of As with Na, HCO3, U, B, V, and Mo (R(2) > 0.5; p ~8, reflecting the pH-dependence of their mobilization. Based on the

  14. Interaction Widget

    DEFF Research Database (Denmark)

    Ingstrup, Mads

    2003-01-01

    This pattern describes the idea of making a user interface of discrete, reusable entities---here called interaction widgets. The idea behind widgets is described using two perspectives, that of the user and that of the developer. It is the forces from these two perspectives that are balanced in t...... in the pattern. The intended audience of the pattern is developers and researchers within the field of human computer interaction.......This pattern describes the idea of making a user interface of discrete, reusable entities---here called interaction widgets. The idea behind widgets is described using two perspectives, that of the user and that of the developer. It is the forces from these two perspectives that are balanced...

  15. Hadronic Interactions

    CERN Document Server

    Yamazaki, Takeshi

    2015-01-01

    Understanding hadronic interactions is crucial for investigating the properties of unstable hadrons, since measuring physical quantities for unstable hadrons including the resonance mass and decay width requires simultaneous calculations of final scattering states. Recent studies of hadronic scatterings and decays are reviewed from this point of view. The nuceon-nucleon and multi-nucleon interactions are very important to understand the formation of nucleus from the first principle of QCD. These interactions have been studied mainly by two methods, due originally to L\\"uscher and to HALQCD. The results obtained from the two methods are compared in three channels, $I=2$ two-pion, H-dibaryon, and two-nucleon channels. So far the results from the two methods for the two-nucleon channels are different even at the level of the presence or absence of bound states. We then discuss possible uncertainties in each method. Recent results on the binding energy for helium nuclei are also reviewed.

  16. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy

    Governance has become one of the most commonly used concepts in contemporary political science. It is, however, often used to mean a variety of different things. This book helps to clarify this conceptual muddle by concentrating on one variety of governance-interactive governance. The authors argue...... that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other governments......, but all these forms represent means of governing involving mixtures of state action with the actions of other entities.This book explores thoroughly this meaning of governance, and links it to broader questions of governance. In the process of explicating this dimension of governance the authors also...

  17. Interactive benchmarking

    DEFF Research Database (Denmark)

    Lawson, Lartey; Nielsen, Kurt

    2005-01-01

    distance functions. The frontier is given by an explicit quantile, e.g. “the best 90 %”. Using the explanatory model of the inefficiency, the user can adjust the frontiers by submitting state variables that influence the inefficiency. An efficiency study of Danish dairy farms is implemented......We discuss individual learning by interactive benchmarking using stochastic frontier models. The interactions allow the user to tailor the performance evaluation to preferences and explore alternative improvement strategies by selecting and searching the different frontiers using directional...... in the suggested benchmarking tool. The study investigates how different characteristics on dairy farms influences the technical efficiency....

  18. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2009-01-01

    Make cool stuff. If you're a designer or artist without a lot of programming experience, this book will teach you to work with 2D and 3D graphics, sound, physical interaction, and electronic circuitry to create all sorts of interesting and compelling experiences -- online and off. Programming Interactivity explains programming and electrical engineering basics, and introduces three freely available tools created specifically for artists and designers: Processing, a Java-based programming language and environment for building projects on the desktop, Web, or mobile phonesArduino, a system t

  19. Collocated Interaction

    DEFF Research Database (Denmark)

    E. Fischer, Joel; Porcheron, Martin; Lucero, Andrés

    2016-01-01

    In the 25 years since Ellis, Gibbs, and Rein proposed the time-space taxonomy, research in the ‘same time, same place’ quadrant has diversified, perhaps even fragmented. This one-day workshop will bring together researchers with diverse, yet convergent interests in tabletop, surface, mobile......, and wearable technologies, spaces and spatial interaction, and those interested in the social aspects of interaction, such as conversation analysis and ethnomethodology. These communities have matured considerably, and produced significant exemplars of systems, methods, and studies concerned with collocated...

  20. Kinesthetic Interaction

    DEFF Research Database (Denmark)

    Fogtmann, Maiken Hillerup; Fritsch, Jonas; Kortbek, Karen Johanne

    2008-01-01

    Within the Human-Computer Interaction community there is a growing interest in designing for the whole body in interaction design. The attempts aimed at addressing the body have very different outcomes spanning from theoretical arguments for understanding the body in the design process, to more...... to reveal bodily potential in relation to three design themes – kinesthetic development, kinesthetic means and kinesthetic disorder; and seven design parameters – engagement, sociality, movability, explicit motivation, implicit motivation, expressive meaning and kinesthetic empathy. The framework is a tool...

  1. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy

    that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other governments...... explore some of the more fundamental questions about governance theory. For example, although governance is talked about a great deal political science has done relatively little about how to measure this concept. Likewise, the term multi-level governance has become widely used but its important...

  2. Interactive Storytelling

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions, an...

  3. Interactive Astronomy.

    Science.gov (United States)

    Martin, Jean K.

    1997-01-01

    Presents guiding principles for developing interactive lessons for the World Wide Web. Describes "Amazing Space: Education Online from the Hubble Space Telescope", a program where students study spectacular Hubble Space Telescope images of stars and star-forming regions to learn about the life cycle of stars and the creation of atoms. (JRH)

  4. Interactive Storytelling

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions...

  5. Discovering functional interaction patterns in protein-protein interaction networks

    Directory of Open Access Journals (Sweden)

    Can Tolga

    2008-06-01

    Full Text Available Abstract Background In recent years, a considerable amount of research effort has been directed to the analysis of biological networks with the availability of genome-scale networks of genes and/or proteins of an increasing number of organisms. A protein-protein interaction (PPI network is a particular biological network which represents physical interactions between pairs of proteins of an organism. Major research on PPI networks has focused on understanding the topological organization of PPI networks, evolution of PPI networks and identification of conserved subnetworks across different species, discovery of modules of interaction, use of PPI networks for functional annotation of uncharacterized proteins, and improvement of the accuracy of currently available networks. Results In this article, we map known functional annotations of proteins onto a PPI network in order to identify frequently occurring interaction patterns in the functional space. We propose a new frequent pattern identification technique, PPISpan, adapted specifically for PPI networks from a well-known frequent subgraph identification method, gSpan. Existing module discovery techniques either look for specific clique-like highly interacting protein clusters or linear paths of interaction. However, our goal is different; instead of single clusters or pathways, we look for recurring functional interaction patterns in arbitrary topologies. We have applied PPISpan on PPI networks of Saccharomyces cerevisiae and identified a number of frequently occurring functional interaction patterns. Conclusion With the help of PPISpan, recurring functional interaction patterns in an organism's PPI network can be identified. Such an analysis offers a new perspective on the modular organization of PPI networks. The complete list of identified functional interaction patterns is available at http://bioserver.ceng.metu.edu.tr/PPISpan/.

  6. CONCEPT OF DRUG INTERACTION

    Directory of Open Access Journals (Sweden)

    Singh Nidhi

    2012-07-01

    Full Text Available Drug interaction is an increasingly important cause of adverse reactions (ADR, and is the modification of the effect of one drug (object by the prior or concomitant administration of another drug (precipitant drug. Drug interaction may either enhance or diminish the intended effect of one or both drugs. For example severe haemorrhage may occur if warfarin and salicylates (asprin are combined. Precipitant drugs modify the object drug's absorption, distribution, metabolism, excretion or actual clinical effect. Nonsteroidal anti-inflammatory drugs, antibiotics and, in particular, rifampin are common precipitant drugs prescribed in primary care practice. Drugs with a narrow therapeutic range or low therapeutic index are more likely to be the objects for serious drug interactions. Object drugs in common use include warfarin, fluoroquinolones, antiepileptic drugs, oral contraceptives, cisapride and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Many other drugs, act as precipitants or objects, and a number of drugs act as both. The aim of present review is to throw light on the concept of drug interaction.

  7. Corticosterone regulates both naturally occurring and cocaine-induced dopamine signaling by selectively decreasing dopamine uptake.

    Science.gov (United States)

    Wheeler, Daniel S; Ebben, Amanda L; Kurtoglu, Beliz; Lovell, Marissa E; Bohn, Austin T; Jasek, Isabella A; Baker, David A; Mantsch, John R; Gasser, Paul J; Wheeler, Robert A

    2017-10-01

    Stressful and aversive events promote maladaptive reward-seeking behaviors such as drug addiction by acting, in part, on the mesolimbic dopamine system. Using animal models, data from our lab and others show that stress and cocaine can interact to produce a synergistic effect on reward circuitry. This effect is also observed when the stress hormone corticosterone is administered directly into the nucleus accumbens (NAc), indicating that glucocorticoids act locally in dopamine terminal regions to enhance cocaine's effects on dopamine signaling. However, prior studies in behaving animals have not provided mechanistic insight. Using fast-scan cyclic voltammetry, we examined the effect of systemic corticosterone on spontaneous dopamine release events (transients) in the NAc core and shell in behaving rats. A physiologically relevant systemic injection of corticosterone (2 mg/kg i.p.) induced an increase in dopamine transient amplitude and duration (both voltammetric measures sensitive to decreases in dopamine clearance), but had no effect on the frequency of transient release events. This effect was compounded by cocaine (2.5 mg/kg i.p.). However, a second experiment indicated that the same injection of corticosterone had no detectable effect on the dopaminergic encoding of a palatable natural reward (saccharin). Taken together, these results suggest that corticosterone interferes with naturally-occurring dopamine uptake locally, and this effect is a critical determinant of dopamine concentration specifically in situations in which the dopamine transporter is pharmacologically blocked by cocaine. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  8. Involuntary conscious memory facilitates cued recall performance: further evidence that chaining occurs during voluntary recall.

    Science.gov (United States)

    Mace, John H

    2009-01-01

    Recent studies have shown that conscious recollection of the past occurs spontaneously when subjects voluntarily recall their own past experiences or a list of previously studied words. Naturalistic diary studies and laboratory studies of this phenomenon, often called involuntary conscious memory (ICM), show that it occurs in 2 ways. One is direct ICM retrieval, which occurs when a cue spontaneously triggers a conscious memory; the other is chained ICM retrieval, which occurs when a retrieved conscious memory spontaneously triggers another. Laboratory studies investigating ICM show that chained ICM retrieval occurs on voluntary autobiographical memory tasks. The present results show that chained ICM retrieval also occurs on a voluntary word list memory task (cued recall). These results are among a handful suggesting that ICM retrieval routinely occurs during voluntary recall.

  9. Experimental and modeling evidence of appendicularian-ciliate interactions

    DEFF Research Database (Denmark)

    Lombard, Fabien; Eloire, Damien; Gobet, Angelique

    2010-01-01

    Interactions between appendicularians and ciliates were observed over the life span of Oikopleura dioica in laboratory cultures and clarified with the use of mathematical modeling and microscopic observations. Complex interactions including competition, parasitism, predation, and histophagy occur...

  10. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.

  11. Interacting Electrons

    Science.gov (United States)

    Martin, Richard M.; Reining, Lucia; Ceperley, David M.

    2016-06-01

    Preface; Part I. Interacting Electrons: Beyond the Independent-Particle Picture: 1. The many electron problem: introduction; 2. Signatures of electron correlation; 3. Concepts and models for interacting electrons; Part II. Foundations of Theory for Many-Body Systems: 4. Mean fields and auxiliary systems; 5. Correlation functions; 6. Many-body wavefunctions; 7. Particles and quasi-particles; 8. Functionals in many-particle physics; Part III. Many-Body Green's Function Methods: 9. Many-body perturbation theory: expansion in the interaction; 10. Many-body perturbation theory via functional derivatives; 11. The RPA and the GW approximation for the self-energy; 12. GWA calculations in practice; 13. GWA calculations: illustrative results; 14. RPA and beyond: the Bethe-Salpeter equation; 15. Beyond the GW approximation; 16. Dynamical mean field theory; 17. Beyond the single-site approximation in DMFT; 18. Solvers for embedded systems; 19. Characteristic hamiltonians for solids with d and f states; 20. Examples of calculations for solids with d and f states; 21. Combining Green's functions approaches: an outlook; Part IV. Stochastic Methods: 22. Introduction to stochastic methods; 23. Variational Monte Carlo; 24. Projector quantum Monte Carlo; 25. Path integral Monte Carlo; 26. Concluding remarks; Part V. Appendices: A. Second quantization; B. Pictures; C. Green's functions: general properties; D. Matsubara formulation for Green's functions for T ̸= 0; E. Time-ordering, contours, and non-equilibrium; F. Hedin's equations in a basis; G. Unique solutions in Green's function theory; H. Properties of functionals; I. Auxiliary systems and constrained search; J. Derivation of the Luttinger theorem; K. Gutzwiller and Hubbard approaches; References; Index.

  12. Interactive Governance

    DEFF Research Database (Denmark)

    Bang, Henrik

    2016-01-01

    Governance analysis has exploded in recent years, and it has become nearly impossible to tell what difference the concept and practice of governance makes from those of government and state. In addition governance analysis has been placed more and more in the shadow of the new institutionalisms and...... and growth. However, interactive governance is not a property or effect of institutions; nor does it apply solely to those individuals who seek success above everything else. It is connective more than individualistic or collectivistic in nature; and it manifests a governability capacity which...

  13. Stratigraphic and geochemical controls on naturally occurring arsenic in groundwater, eastern Wisconsin, USA

    Science.gov (United States)

    Schreiber, M. E.; Simo, J. A.; Freiberg, P. G.

    High arsenic concentrations (up to 12,000μg/L) have been measured in groundwater from a confined sandstone aquifer in eastern Wisconsin. The main arsenic source is a sulfide-bearing secondary cement horizon (SCH) that has variable thickness, morphology, and arsenic concentrations. Arsenic occurs in pyrite and marcasite as well as in iron oxyhydroxides but not as a separate arsenopyrite phase. Nearly identical sulfur isotopic signatures in pyrite and dissolved sulfate and the correlation between dissolved sulfate, iron, and arsenic concentrations suggest that sulfide oxidation is the dominant process controlling arsenic release to groundwater. However, arsenic-bearing oxyhydroxides can potentially provide another arsenic source if reducing conditions develop or if they are transported as colloids in the aquifer. Analysis of well data indicates that the intersection of the SCH with static water levels measured in residential wells is strongly correlated with high concentrations of arsenic in groundwater. Field and laboratory data suggest that the most severe arsenic contamination is caused by localized borehole interactions of air, water, and sulfides. Although arsenic contamination is caused by oxidation of naturally occurring sulfides, it is influenced by water-level fluctuations caused by municipal well pumping or climate changes, which can shift geographic areas in which contamination occurs. Résumé De fortes concentrations en arsenic, jusqu'à 12000μg/L, ont été mesurées dans l'eau souterraine d'un aquifère gréseux captif, dans l'est du Wisconsin. La principale source d'arsenic est un horizon à cimentation secondaire (SCH) comportant des sulfures, dont l'épaisseur, la morphologie et les concentrations en arsenic sont variables. L'arsenic est présent dans la pyrite et dans la marcassite, de même que dans des oxy-hydroxydes de fer, mais non pas dans une phase séparée d'arsénopyrite. Les signatures isotopiques du soufre presque identiques dans la

  14. Naturally-occurring changes in social-cognitive factors modify change in physical activity during early adolescence

    Science.gov (United States)

    Dowda, Marsha; McIver, Kerry L.; Saunders, Ruth P.; Pate, Russell R.

    2017-01-01

    Purpose To determine whether naturally-occurring changes in children’s motives and beliefs are associated with the steep decline in physical activity observed from childhood to early adolescence. Methods Latent growth modeling was applied in longitudinal tests of social-cognitive influences, and their interactions, on physical activity in a large cohort of boys and girls evaluated annually between 5th and 7th grades. Results Measurement equivalence of motives and beliefs was confirmed between boys and girls. After adjustment for gender and maturity differences, physical activity declined less in children who reported the least decreases in self-efficacy for overcoming barriers to activity and perceived parental support. Physical activity also declined less in students who persistently felt they had more parental and friend support for activity compared to those who reported the largest decrease in support from friends. After further adjustment for race, the decline in physical activity was less in those who had the largest decrease in perceived barriers and maintained a favorable perception of their neighborhood environment. Changes in enjoyment and social motives were unrelated to change in physical activity. Conclusion Using an objective measure of physical activity, we confirm that naturally-occurring changes in children’s beliefs about barriers to physical activity and their ability to overcome them, as well as perceptions of their neighborhood environment and social support, are concurrent with age-related declines in children’s physical activity. The longitudinal findings confirm these putative social-cognitive mediators as plausible, interacting targets of interventions designed to mitigate the marked decline in physical activity that occurs during the transition between elementary and middle schools. PMID:28187192

  15. Sibling interaction.

    Science.gov (United States)

    Balsam, Rosemary H

    2013-01-01

    Sibling interactions traditionally were conceived psychoanalytically in "vertical" and parentified oedipal terms and overlooked in their own right, for complicated reasons (Colonna and Newman 1983). Important work has been done to right this, from the 1980s and onward, with conferences and writings. Juliet Mitchell's 2000 and, in particular, her 2003 books, for example, have brought "lateral" sibling relations forcefully to the forefront of insights, especially about sex and violence, with the added interdisciplinary impact of illuminating upheaval in global community interactions as well as having implications for clinicians. A clinical example from the analysis of an adult woman with a ten-years-younger sister will show here how we need both concepts to help us understand complex individual psychic life. The newer "lateral" sibling emphasis, including Mitchell's "Law of the Mother" and "seriality," can be used to inform the older "vertical" take, to enrich the full dimensions of intersubjective oedipal and preoedipal reciprocities that have been foundational in shaping that particular analysand's inner landscape. Some technical recommendations for heightening sensitivity to the import of these dynamics will be offered along the way here, by invoking Hans Loewald's useful metaphor of the analytic situation as theater.

  16. Mediated Interactions and Musical Expression - A Survey

    NARCIS (Netherlands)

    Reidsma, Dennis; Radha, Mustafa; Nijholt, Antinus; Lee, Newton

    2014-01-01

    This chapter surveys the field of technologically mediated musical interaction and technologically enhanced musical expression. We look at several new technologies that enable new ways of musical expression and interaction, explore the micro-coordination that occurs in collaborative musical performa

  17. Using Interaction Scenarios to Model Information Systems

    DEFF Research Database (Denmark)

    Bækgaard, Lars; Bøgh Andersen, Peter

    The purpose of this paper is to define and discuss a set of interaction primitives that can be used to model the dynamics of socio-technical activity systems, including information systems, in a way that emphasizes structural aspects of the interaction that occurs in such systems. The primitives...

  18. Biosynthesis of the Escherichia coli K1 group 2 polysialic acid capsule occurs within a protected cytoplasmic compartment.

    Science.gov (United States)

    Steenbergen, Susan M; Vimr, Eric R

    2008-06-01

    Capsular polysaccharides are important virulence determinants in a wide range of invasive infectious diseases. Although capsule synthesis has been extensively investigated, understanding polysaccharide export from the cytoplasm to the external environment has been more difficult. Here we present the results of a novel protection assay indicating that synthesis and export of the Escherichia coli K1 group 2 capsular polysialic acid (K1 antigen) occur within a protected subcellular compartment designated the sialisome. In addition to the polymerase encoded by neuS, localization and complementation analyses indicated that the sialisome includes the accessory membrane protein NeuE. The requirement for NeuE was suppressed by overproducing NeuS, suggesting that NeuE functions by stabilizing the polymerase or facilitating its assembly in the sialisome. Although an interaction between NeuE and NeuS could not be demonstrated with a bacterial two-hybrid system that reconstitutes an intracellular cell-signalling pathway, interactions between NeuS and KpsC as well as other sialisome components were detected. The combined results provide direct evidence for specific protein-protein interactions in the synthesis and export of group 2 capsular polysaccharides under in vivo conditions. The approaches developed here will facilitate further dissection of the sialisome, suggesting similar methodology for understanding the biosynthesis of other group 2 capsules.

  19. Representation, interaction, and intersubjectivity.

    Science.gov (United States)

    Alterman, Richard

    2007-09-10

    What the participants share, their common "sense" of the world, creates a foundation, a framing, an orientation that enables human actors to see and act in coordination with one another. For recurrent activities, the methods the participants use to understand each other as they act change, making the intersubjective space in which actors operate richer and easier to produce. This article works through some of the issues that emerge from a close examination of intersubjectivity as it is managed through representation and interaction. The data that are presented document, in detail, a sequence of related interactions, within and across episodes of cooperation, where continuity and change can be observed. The emergence of conversational structure and coordinating representations are significant milestones in the long-term development of a representational practice that support the runtime co-construction of intersubjective space. Conversational structures emerge interactively to mediate recurrent points of coordination in the domain activity, and only secondarily the conversation itself. Coordinating representations change the representational practice of the participants by making it easier to manage their "shared view" of the collective work, enabling the participants to make progress, expand the field of the common activity, while exhibiting more control of if and when explicit grounding occurs.

  20. Linking express saccade occurance to stimulus properties and sensorimotor integration in the superior colliculus.

    Science.gov (United States)

    Marino, Robert A; Levy, Ron; Munoz, Douglas P

    2015-08-01

    Express saccades represent the fastest possible eye movements to visual targets with reaction times that approach minimum sensory-motor conduction delays. Previous work in monkeys has identified two specific neural signals in the superior colliculus (SC: a midbrain sensorimotor integration structure involved in gaze control) that are required to execute express saccades: 1) previsual activity consisting of a low-frequency increase in action potentials in sensory-motor neurons immediately before the arrival of a visual response; and 2) a transient visual-sensory response consisting of a high-frequency burst of action potentials in visually responsive neurons resulting from the appearance of a visual target stimulus. To better understand how these two neural signals interact to produce express saccades, we manipulated the arrival time and magnitude of visual responses in the SC by altering target luminance and we examined the corresponding influences on SC activity and express saccade generation. We recorded from saccade neurons with visual-, motor-, and previsual-related activity in the SC of monkeys performing the gap saccade task while target luminance was systematically varied between 0.001 and 42.5 cd/m(2) against a black background (∼0.0001 cd/m(2)). Our results demonstrated that 1) express saccade latencies were linked directly to the arrival time in the SC of visual responses produced by abruptly appearing visual stimuli; 2) express saccades were generated toward both dim and bright targets whenever sufficient previsual activity was present; and 3) target luminance altered the likelihood of producing an express saccade. When an express saccade was generated, visuomotor neurons increased their activity immediately before the arrival of the visual response in the SC and saccade initiation. Furthermore, the visual and motor responses of visuomotor neurons merged into a single burst of action potentials, while the visual response of visual-only neurons was

  1. Electromagnetic interactions

    CERN Document Server

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  2. Electromagnetic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bosanac, Slobodan Danko [Ruder Boskovic Institute, Zagreb (Croatia). Physical Chemistry

    2016-07-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  3. Audiovisual Interaction

    DEFF Research Database (Denmark)

    Karandreas, Theodoros-Alexandros

    Product sound quality evaluation aims to identify relevant attributes and assess their influence on the overall auditory impression. This results in an accurate representation of the product in a singular modality - usually the one primarily associated with the product's main function. However, any...... given product is rarely perceived in isolation, but rather judged within a global context which includes information from all modalities (senses). This PhD thesis investigates the relative importance of audio and visual information in subjective evaluations of a product. A multimodal setup was developed...... importance of each modality with respect to the overall quality evaluation. The results show that this was not due to specific interactions between stimuli but rather because the auditory modality dominated over the visual modality. Furthermore, for all experiments where less than optimal stimuli...

  4. 30 CFR 254.46 - Whom do I notify if an oil spill occurs?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Whom do I notify if an oil spill occurs? 254.46... Outer Continental Shelf Facilities § 254.46 Whom do I notify if an oil spill occurs? (a) You must immediately notify the National Response Center (1-800-424-8802) if you observe: (1) An oil spill from...

  5. Segregation of naturally occurring mitochondrial DNA variants in a mini-pig model

    Science.gov (United States)

    Within cells and tissues, the maternally inherited mitochondrial genome (mtDNA) is present in multimeric form and can harbour naturally occurring variants. Whilst high variant load can cause mitochondrial disease, naturally occurring mtDNA variants likely persist at low levels across generations of ...

  6. Consequences of Co-Occurring Attention-Deficit/Hyperactivity Disorder on Children's Language Impairments

    Science.gov (United States)

    Redmond, Sean M.; Ash, Andrea C.; Hogan, Tiffany P.

    2015-01-01

    Purpose: Co-occurring attention-deficit/hyperactivity disorder (ADHD) and communication disorders represent a frequently encountered challenge for school-based practitioners. The purpose of the present study was to examine in more detail the clinical phenomenology of co-occurring ADHD and language impairments (LIs). Method: Measures of nonword…

  7. Two-Electron Transfer Pathways.

    Science.gov (United States)

    Lin, Jiaxing; Balamurugan, D; Zhang, Peng; Skourtis, Spiros S; Beratan, David N

    2015-06-18

    The frontiers of electron-transfer chemistry demand that we develop theoretical frameworks to describe the delivery of multiple electrons, atoms, and ions in molecular systems. When electrons move over long distances through high barriers, where the probability for thermal population of oxidized or reduced bridge-localized states is very small, the electrons will tunnel from the donor (D) to acceptor (A), facilitated by bridge-mediated superexchange interactions. If the stable donor and acceptor redox states on D and A differ by two electrons, it is possible that the electrons will propagate coherently from D to A. While structure-function relations for single-electron superexchange in molecules are well established, strategies to manipulate the coherent flow of multiple electrons are largely unknown. In contrast to one-electron superexchange, two-electron superexchange involves both one- and two-electron virtual intermediate states, the number of virtual intermediates increases very rapidly with system size, and multiple classes of pathways interfere with one another. In the study described here, we developed simple superexchange models for two-electron transfer. We explored how the bridge structure and energetics influence multielectron superexchange, and we compared two-electron superexchange interactions to single-electron superexchange. Multielectron superexchange introduces interference between singly and doubly oxidized (or reduced) bridge virtual states, so that even simple linear donor-bridge-acceptor systems have pathway topologies that resemble those seen for one-electron superexchange through bridges with multiple parallel pathways. The simple model systems studied here exhibit a richness that is amenable to experimental exploration by manipulating the multiple pathways, pathway crosstalk, and changes in the number of donor and acceptor species. The features that emerge from these studies may assist in developing new strategies to deliver multiple

  8. Designing "Interaction": How Do Interaction Design Students Address Interaction?

    Science.gov (United States)

    Karlgren, Klas; Ramberg, Robert; Artman, Henrik

    2016-01-01

    Interaction design is usually described as being concerned with interactions with and through artifacts but independent of a specific implementation. Design work has been characterized as a conversation between the designer and the situation and this conversation poses a particular challenge for interaction design as interactions can be elusive…

  9. Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments.

    Science.gov (United States)

    Trautz, Andrew C; Illangasekare, Tissa H; Rodriguez-Iturbe, Ignacio

    2017-08-29

    Plant performance (i.e., fecundity, growth, survival) depends on an individual's access to space and resources. At the community level, plant performance is reflected in observable vegetation patterning (i.e., spacing distance, density) often controlled by limiting resources. Resource availability is, in turn, strongly dependent on plant patterning mediated by competitive and facilitative plant-plant interactions. Co-occurring competition and facilitation has never been specifically investigated from a hydrodynamic perspective. To address this knowledge gap, and to overcome limitations of field studies, three intermediate-scale laboratory experiments were conducted using a climate-controlled wind tunnel-porous media test facility to simulate the soil-plant-atmosphere continuum. The spacing between two synthetic plants, a design consideration introduced by the authors in a recent publication, was varied between experiments; edaphic and mean atmospheric conditions were held constant. The strength of the above- and belowground plant-plant interactions changed with spacing distance, allowing the creation of a hydrodynamic conceptual model based on established ecological theories. Greatest soil water loss was observed for the experiment with the smallest spacing where competition dominated. Facilitation dominated at the intermediate spacing; little to no interactions were observed for the largest plant spacing. Results suggest that there exists an optimal spacing distance range that lowers plant environmental stress, thus improving plant performance through reduced atmospheric demand and conservation of available soil water. These findings may provide a foundation for improving our understanding of many climatological, ecohydrological, and hydrological problems pertaining to the hydrodynamics of water-limited environments where plant-plant interactions and community self-organization are important.

  10. Bunyavirus-vector interactions.

    Science.gov (United States)

    Beaty, B J; Bishop, D H

    1988-06-01

    Recent advances in the genetics and molecular biology of bunyaviruses have been applied to understanding bunyavirus-vector interactions. Such approaches have revealed which virus gene and gene products are important in establishing infections in vectors and in transmission of viruses. However, much more information is required to understand the molecular mechanisms of persistent infections of vectors which are lifelong but apparently exert no untoward effect. In fact, it seems remarkable that LAC viral antigen can be detected in almost every cell in an ovarian follicle, yet no untoward effect on fecundity and no teratology is seen. Similarly the lifelong infection of the vector would seem to provide ample opportunity for bunyavirus evolution by genetic drift and, under the appropriate circumstances, by segment reassortment. The potential for bunyavirus evolution by segment reassortment in vectors certainly exists. For example the Group C viruses in a small forest in Brazil seem to constitute a gene pool, with the 6 viruses related alternately by HI/NT and CF reactions, which assay respectively M RNA and S RNA gene products (Casals and Whitman, 1960; Shope and Causey, 1962). Direct evidence for naturally occurring reassortant bunyaviruses has also been obtained. Oligonucleotide fingerprint analyses of field isolates of LAC virus and members of the Patois serogroup of bunyaviruses have demonstrated that reassortment does occur in nature (El Said et al., 1979; Klimas et al., 1981; Ushijima et al., 1981). Determination of the genotypic frequencies of viruses selected by the biological interactions of viruses and vectors after dual infection and segment reassortment is an important issue. Should a virus result that efficiently interacts with alternate vector species, the virus could be expressed in different circumstances with serious epidemiologic consequences. Dual infection of vectors with different viruses is not unlikely, because many bunyaviruses are sympatric in

  11. Cloud Interactions

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 1 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere. Image information: VIS instrument. Latitude 68.4, Longitude 258.8 East (101.2 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara

  12. Interactions in an acoustic world

    CERN Document Server

    Simaciu, Ion; Borsos, Zoltan; Bradac, Mariana

    2016-01-01

    The present paper aims to complete an earlier paper where the acoustic world was introduced. This is accomplished by analyzing the interactions which occur between the inhomogeneities of the acoustic medium, which are induced by the acoustic vibrations traveling in the medium. When a wave packet travels in a medium, the medium becomes inhomogeneous. The spherical wave packet behaves like an acoustic spherical lens for the acoustic plane waves. According to the principle of causality, there is an interaction between the wave and plane wave packet. In specific conditions the wave packet behaves as an acoustic black hole.

  13. A Review on Analysis and Synthesis of Nonlinear Stochastic Systems with Randomly Occurring Incomplete Information

    Directory of Open Access Journals (Sweden)

    Hongli Dong

    2012-01-01

    Full Text Available In the context of systems and control, incomplete information refers to a dynamical system in which knowledge about the system states is limited due to the difficulties in modeling complexity in a quantitative way. The well-known types of incomplete information include parameter uncertainties and norm-bounded nonlinearities. Recently, in response to the development of network technologies, the phenomenon of randomly occurring incomplete information has become more and more prevalent. Such a phenomenon typically appears in a networked environment. Examples include, but are not limited to, randomly occurring uncertainties, randomly occurring nonlinearities, randomly occurring saturation, randomly missing measurements and randomly occurring quantization. Randomly occurring incomplete information, if not properly handled, would seriously deteriorate the performance of a control system. In this paper, we aim to survey some recent advances on the analysis and synthesis problems for nonlinear stochastic systems with randomly occurring incomplete information. The developments of the filtering, control and fault detection problems are systematically reviewed. Latest results on analysis and synthesis of nonlinear stochastic systems are discussed in great detail. In addition, various distributed filtering technologies over sensor networks are highlighted. Finally, some concluding remarks are given and some possible future research directions are pointed out.

  14. Modes of interactions between environmental drivers and marine biota

    Directory of Open Access Journals (Sweden)

    Philip eBoyd

    2015-02-01

    Full Text Available The responses of marine biota to global ocean change is characterised by multiple environmental drivers that interact to cause non-linear changes in organismal performance. Characterising interactions is critical for us to predict whether multiple drivers will accelerate or mitigate future biological responses. There is now a large body of evidence that drivers do not act independently, a common null model, but rather have synergistic or antagonistic effects on organisms. We review the literature on interactions among environmental drivers such as ocean acidification and warming, and identify three common modes of interaction: physicochemical interactions in the seawater media outside organisms, interactions that operate on organisms directly, for example by altering physiological rates; and interactions that occur through changes in ecosystems, like predation. Interactions can also occur across these levels increasing the number of permutations for interaction, and point to a diverse range of modes of interplay. Identifying the appropriate mode will help generalise interaction types to unstudied contexts.

  15. Informal Language Learning Setting: Technology or Social Interaction?

    Science.gov (United States)

    Bahrani, Taher; Sim, Tam Shu

    2012-01-01

    Based on the informal language learning theory, language learning can occur outside the classroom setting unconsciously and incidentally through interaction with the native speakers or exposure to authentic language input through technology. However, an EFL context lacks the social interaction which naturally occurs in an ESL context. To explore…

  16. Characteristics and Implication of the Earthquake Swarm Occurred in Fuzhou in September 1999

    Institute of Scientific and Technical Information of China (English)

    Yuan Dingqiang; Wang Jian

    2001-01-01

    On September 23, 1999, an earthquake swarm occurred in Fuzhou. Because the swarm occurred in the region where earthquakes occurred scarcely before and very close to the center of the city as well as shortly after the Jiji earthquake with Ms7.6 in Taiwan, September 21, 1999, has aroused interest broadly. In this paper, we analyzed the characteristics of spatial and temporal distribution of the earthquake swarm and validated magnitude-number constituent of the swarm is special. In present theory, the earthquake swarm means that a small scale macro original rupture has formed in the layer of the crust in Fuzhou region where moderately strong earthquake risk exists.

  17. Predicting Emotions in Facial Expressions from the Annotations in Naturally Occurring First Encounters

    DEFF Research Database (Denmark)

    Navarretta, Costanza

    2014-01-01

    This paper deals with the automatic identification of emotions from the manual annotations of the shape and functions of facial expressions in a Danish corpus of video recorded naturally occurring first encounters. More specifically, a support vector classified is trained on the corpus annotation...... to it are reliable and can be used to model and test emotional behaviours in emotional cognitive infocommunicative systems.......This paper deals with the automatic identification of emotions from the manual annotations of the shape and functions of facial expressions in a Danish corpus of video recorded naturally occurring first encounters. More specifically, a support vector classified is trained on the corpus annotations...... to identify emotions in facial expressions. In the classification experiments, we test to what extent emotions expressed in naturally-occurring conversations can be identified automatically by a classifier trained on the manual annotations of the shape of facial expressions and co-occurring speech tokens. We...

  18. Surfing wavy surfaces: Bacteria-surface interactions in flow

    Science.gov (United States)

    Miño, Gastón L.; Kantsler, Vasily; Stocker, Roman

    2014-11-01

    Complex processes occur when microbes interact with surfaces, from mixture enhancement and motion rectification to biofilm formation. Microbe-surface interactions frequently occur in flowing fluids, and flow has recently been shown to have itself unexpected consequences on the dynamics of motile microbes. Here we report on microfluidic experiments in which the interactions of Escherichia coli bacteria with wavy surfaces was quantified in the presence of fluid flow, a model system for naturally occurring topography of many real surfaces. We quantify surface interactions in terms of incident and scattering angles over a range of flow conditions, and compare results to the observations for a microchannel with straight walls.

  19. Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain

    Science.gov (United States)

    2014-01-01

    Annual Forum, Montreal, Canada, 2002. 3. Samuel, P. D.; Pines, D. J. A Review of Vibration Based Techniques for Helicopter Transmission Diagnostics...Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain by Kelsen E. LaBerge, Eric C. Ames, and Brian D. Dykas...5066 ARL-TR-6795 January 2014 Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain Kelsen E. LaBerge

  20. Autism and Obesity: Co-Occurring Conditions or Drug Side Effects

    Science.gov (United States)

    2015-10-01

    AWARD NUMBER: W81XWH-14-1-0374 TITLE: Autism and Obesity : Co-Occurring Conditions or Drug Side Effects? PRINCIPAL INVESTIGATOR: Zohreh...SUBTITLE Autism and Obesity : Co-Occurring Conditions or Drug Side Effects? 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0374 5c. PROGRAM ELEMENT...on the BMI data into obese , overweight, healthy and underweight categories. [3] Using a rigorous literature search dbSNP search, we collected data on

  1. Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) in the Oil and Gas Industry: A Review.

    Science.gov (United States)

    Doyi, Israel; Essumang, David Kofi; Dampare, Samuel; Glover, Eric Tetteh

    Radiation is part of the natural environment: it is estimated that approximately 80 % of all human exposure comes from naturally occurring or background radiation. Certain extractive industries such as mining and oil logging have the potential to increase the risk of radiation exposure to the environment and humans by concentrating the quantities of naturally occurring radiation beyond normal background levels (Azeri-Chirag-Gunashli 2004).

  2. Descriptions of selected accidents that have occurred at nuclear reactor facilities

    Energy Technology Data Exchange (ETDEWEB)

    Bertini, H.W.

    1980-04-01

    This report was prepared at the request of the President's Commission on the Accident at Three Mile Island to provide the members of the Commission with some insight into the nature and significance of accidents that have occurred at nuclear reactor facilities in the past. Toward that end, this report presents a brief description of 44 accidents which have occurred throughout the world and which meet at least one of the severity criteria that were established.

  3. Conservative Management of Skin Fistula Occurring After Internal Cardioverter Defibrillator Replacement

    OpenAIRE

    2012-01-01

    Skin fistula occurring after cardiac electronic device implantation is frequently related to pocket infection and this condition typically requires removal of device and lead(s). We report on a case of skin fistula occurring 3 weeks after internal cardioverter defibrillator replacement. Conservative management consisted of local care along with oral antibiotics without removal of device; this strategy resulted in complete healing and closure of the fistula.

  4. Hospitalizations and hospital charges for co-occurring substance use and mental disorders.

    Science.gov (United States)

    Ding, Kele; Yang, Jingzhen; Cheng, Gang; Schiltz, Trisha; Summers, Karen M; Skinstad, Anne Helene

    2011-06-01

    Most published studies have examined co-occurring disorders among mental health patients. Our objective was to compare the length of stay and hospital charges between hospitalized patients with alcohol- or substance-related disorders with and without co-occurring disorders. We analyzed nationally representative hospital discharge data (Nationwide Inpatient Sample, 2003-2007) and examined factors associated with length of stay and hospital charges. Forty-four percent of patients who were hospitalized with alcohol- or substance-related disorders were diagnosed with co-occurring mental disorders, representing 979,421 such disorders nationwide between 2003 and 2007. Females, those of White race, those who paid with insurance, and those who stayed in large, rural, nonteaching, and Midwest region hospitals had a high prevalence of co-occurring disorders. Co-occurring disorders were associated with longer hospital stays, but there were mixed results with hospital charges per discharge. An increase in co-occurring disorders among hospitalized patients with substance-related disorder may be due to the improvement in diagnosis and clinical attention.

  5. Unification of Electromagnetic Interactions and Gravitational Interactions

    Institute of Scientific and Technical Information of China (English)

    WUNing

    2002-01-01

    Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle,electromagnetic interactions and gravitational interactions are formulated in the same manner and are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.

  6. Unification of Electromagnetic Interactions and Gravitational Interactions

    Institute of Scientific and Technical Information of China (English)

    WU Ning

    2002-01-01

    Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle, electromagnetic interactions and gravitational interactions are formulated in the same mannerand are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.

  7. The stretch-shortening cycle : a model to study naturally occurring neuromuscular fatigue.

    Science.gov (United States)

    Nicol, Caroline; Avela, Janne; Komi, Paavo V

    2006-01-01

    Neuromuscular fatigue has traditionally been examined using isolated forms of either isometric, concentric or eccentric actions. However, none of these actions are naturally occurring in human (or animal) ground locomotion. The basic muscle function is defined as the stretch-shortening cycle (SSC), where the preactivated muscle is first stretched (eccentric action) and then followed by the shortening (concentric) action. As the SSC taxes the skeletal muscles very strongly mechanically, its influence on the reflex activation becomes apparent and very different from the isolated forms of muscle actions mentioned above. The ground contact phases of running, jumping and hopping etc. are examples of the SSC for leg extensor muscles; similar phases can also be found for the upper-body activities. Consequently, it is normal and expected that the fatigue phenomena should be explored during SSC activities. The fatigue responses of repeated SSC actions are very versatile and complex because the fatigue does not depend only on the metabolic loading, which is reportedly different among muscle actions. The complexity of SSC fatigue is well reflected by the recovery patterns of many neuromechanical parameters. The basic pattern of SSC fatigue response (e.g. when using the complete exhaustion model of hopping or jumping) is the bimodality showing an immediate reduction in performance during exercise, quick recovery within 1-2 hours, followed by a secondary reduction, which may often show the lowest values on the second day post-exercise when the symptoms of muscle soreness/damage are also greatest. The full recovery may take 4-8 days depending on the parameter and on the severity of exercise. Each subject may have their own time-dependent bimodality curve. Based on the reviewed literature, it is recommended that the fatigue protocol is 'completely' exhaustive to reduce the important influence of inter-subject variability in the fatigue responses. The bimodality concept is

  8. Imaging physicochemical reactions occurring at the pore surface in binary bioactive glass foams by micro ion beam analysis.

    Science.gov (United States)

    Jallot, E; Lao, J; John, L; Soulié, J; Moretto, Ph; Nedelec, J M

    2010-06-01

    In this work, the physicochemical reactions occurring at the surface of bioactive sol-gel derived 3D glass scaffolds via a complete PIXE characterization were studied. 3D glass foams in the SiO(2)-CaO system were prepared by sol-gel route. Samples of glass scaffolds were soaked in biological fluids for periods up to 2 days. The surface changes were characterized using particle induced X-ray emission (PIXE) associated to Rutherford backscattering spectroscopy (RBS), which are efficient methods to perform quantitative chemical maps. Elemental maps of major and trace elements at the glass/biological fluids interface were obtained at the micrometer scale for every interaction time. Results revealed interconnected macropores and physicochemical reactions occurring at the surface of pores. The micro-PIXE-RBS characterization of the pores/biological fluids interface shows the glass dissolution and the rapid formation of a Ca rich layer with the presence of phosphorus that came from biological fluids. After 2 days, a calcium phosphate-rich layer containing magnesium is formed at the surface of the glass scaffolds. We demonstrate that quantities of phosphorus provided only by the biological medium have a significant impact on the development and the formation of the phosphocalcic layer.

  9. Electrophysiological correlates of reinforcement learning in young people with Tourette syndrome with and without co-occurring ADHD symptoms.

    Science.gov (United States)

    Shephard, Elizabeth; Jackson, Georgina M; Groom, Madeleine J

    2016-06-01

    Altered reinforcement learning is implicated in the causes of Tourette syndrome (TS) and attention-deficit/hyperactivity disorder (ADHD). TS and ADHD frequently co-occur but how this affects reinforcement learning has not been investigated. We examined the ability of young people with TS (n=18), TS+ADHD (N=17), ADHD (n=13) and typically developing controls (n=20) to learn and reverse stimulus-response (S-R) associations based on positive and negative reinforcement feedback. We used a 2 (TS-yes, TS-no)×2 (ADHD-yes, ADHD-no) factorial design to assess the effects of TS, ADHD, and their interaction on behavioural (accuracy, RT) and event-related potential (stimulus-locked P3, feedback-locked P2, feedback-related negativity, FRN) indices of learning and reversing the S-R associations. TS was associated with intact learning and reversal performance and largely typical ERP amplitudes. ADHD was associated with lower accuracy during S-R learning and impaired reversal learning (significantly reduced accuracy and a trend for smaller P3 amplitude). The results indicate that co-occurring ADHD symptoms impair reversal learning in TS+ADHD. The implications of these findings for behavioural tic therapies are discussed.

  10. Marine ecosystem acoustics (MEA): Quantifying processes in the sea at the spatio-temporal scales on which they occur

    KAUST Repository

    Godøl, Olav Rune

    2014-07-22

    Sustainable management of fisheries resources requires quantitative knowledge and understanding of species distribution, abundance, and productivity-determining processes. Conventional sampling by physical capture is inconsistent with the spatial and temporal scales on which many of these processes occur. In contrast, acoustic observations can be obtained on spatial scales from centimetres to ocean basins, and temporal scales from seconds to seasons. The concept of marine ecosystem acoustics (MEA) is founded on the basic capability of acoustics to detect, classify, and quantify organisms and biological and physical heterogeneities in the water column. Acoustics observations integrate operational technologies, platforms, and models and can generate information by taxon at the relevant scales. The gaps between single-species assessment and ecosystem-based management, as well as between fisheries oceanography and ecology, are thereby bridged. The MEA concept combines state-of-the-art acoustic technology with advanced operational capabilities and tailored modelling integrated into a flexible tool for ecosystem research and monitoring. Case studies are presented to illustrate application of the MEA concept in quantification of biophysical coupling, patchiness of organisms, predator-prey interactions, and fish stock recruitment processes. Widespread implementation of MEA will have a large impact on marine monitoring and assessment practices and it is to be hoped that they also promote and facilitate interaction among disciplines within the marine sciences.

  11. Relationality and social interaction.

    Science.gov (United States)

    Bottero, Wendy

    2009-06-01

    This paper explores Bourdieu's account of a relational social space, and his relative neglect of social interaction within this framework. Bourdieu includes social capital as one of the key relational elements of his social space, but says much less about it than economic or cultural capital, and levels of social capital are rarely measured in his work. Bourdieu is reluctant to focus on the content of social networks as part of his rejection of substantialist thinking. The neglect of substantive networks creates problems for Bourdieu's framework, because many of Bourdieu's core concepts rest upon assumptions about their interactional properties (in particular, the prevalence of homophilous differential association) which are left unexamined. It is argued here that Bourdieu's neglect of the substance of social networks is related to the criticisms that Bourdieu's framework often encounters, and that this neglect bears re-examination, since it is helpful to think of the ways in which differentiated social networks contribute to the development of habitus, help form fields, and so constitute the intersubjective social relations within which sociality, and practice more generally, occur.

  12. PIC. Profile of Interaction in the Classroom. A Quick Feedback of Interaction Analysis.

    Science.gov (United States)

    Brunner, Ellen

    The Profile of Interaction in the Classroom (PIC) is a short-cut method of interaction analysis that can provide the quick feedback essential to effective supervision of instruction. And because the PIC contains a record of all the behaviors that occurred in the classroom, as well as the sequence, the data may be used to build a traditional…

  13. Long-range intramolecular electron transfer in aromatic radical anions and binuclear transition metal complexes

    DEFF Research Database (Denmark)

    Kuznetsov, A. M.; Ulstrup, Jens

    1981-01-01

    Intramolecular electron transfer (ET) over distances up to about 10 Å between states in which the electron is localized on donor and acceptor groups by interaction with molecular or external solvent nuclear motion occurs, in particular, in two classes of systems. The excess electron in anionic...... in the intermediate states. We have furthermore provided criteria for the distinction between direct ET, ET through high-energy (superexchange), and low-energy (''radical'' intermediate mechanism) intermediate states on the basis of experimental rate data and illustrated this with data for organic radical anions...

  14. Quantum simulation with interacting photons

    Science.gov (United States)

    Hartmann, Michael J.

    2016-10-01

    Enhancing optical nonlinearities so that they become appreciable on the single photon level and lead to nonclassical light fields has been a central objective in quantum optics for many years. After this has been achieved in individual micro-cavities representing an effectively zero-dimensional volume, this line of research has shifted its focus towards engineering devices where such strong optical nonlinearities simultaneously occur in extended volumes of multiple nodes of a network. Recent technological progress in several experimental platforms now opens the possibility to employ the systems of strongly interacting photons, these give rise to as quantum simulators. Here we review the recent development and current status of this research direction for theory and experiment. Addressing both, optical photons interacting with atoms and microwave photons in networks of superconducting circuits, we focus on analogue quantum simulations in scenarios where effective photon-photon interactions exceed dissipative processes in the considered platforms.

  15. Quantum Simulation with Interacting Photons

    CERN Document Server

    Hartmann, Michael J

    2016-01-01

    We review the theoretical and experimental developments in recent research on quantum simulators with interacting photons. Enhancing optical nonlinearities so that they become appreciable on the single photon level and lead to nonclassical light fields has been a central objective in quantum optics for many years. After this has been achieved in individual micro-cavities representing an effectively zero-dimensional volume, this line of research has now shifted its focus towards engineering devices where such strong optical nonlinearities simultaneously occur in extended volumes of multiple nodes of a network. Recent technological progress in several experimental platforms now opens the possibility to employ the systems of strongly interacting photons these give rise to as quantum simulators. Here we review the recent development and current status of this research direction for theory and experiment. Addressing both, optical photons interacting with atoms and microwave photons in networks of superconducting c...

  16. Production of personalized protein microarrays : optimized production of protein microarrays and the establishment of processes for the representation of protein conformations that occur in individual patients

    OpenAIRE

    2014-01-01

    Despite remarkable progress in understanding biology and disease at the level of nucleic acids, insights into the relevant biochemical processes frequently remain preliminary, since much regulation and activity occurs at the protein level through control of gene expression and variations of protein conformation. In particular, the effect of such variations on protein interactions is critical for a better description of biology and disease. Protein microarray technology provides a means to suc...

  17. Predicting Emotions in Facial Expressions from the Annotations in Naturally Occurring First Encounters

    DEFF Research Database (Denmark)

    Navarretta, Costanza

    2014-01-01

    This paper deals with the automatic identification of emotions from the manual annotations of the shape and functions of facial expressions in a Danish corpus of video recorded naturally occurring first encounters. More specifically, a support vector classified is trained on the corpus annotations...... to identify emotions in facial expressions. In the classification experiments, we test to what extent emotions expressed in naturally-occurring conversations can be identified automatically by a classifier trained on the manual annotations of the shape of facial expressions and co-occurring speech tokens. We...... also investigate the relation between emotions and the communicative functions of facial expressions. Both emotion labels and their values in a three dimensional space are identified. The three dimensions are Pleasure, Arousal and Dominance. The results of our experiments indicate that the classifiers...

  18. Sclerotic multiple myeloma with an unusual sunburst periosteal reaction occurring in the sternum.

    Science.gov (United States)

    Li, Yuqing; Wu, Wenjuan; Zhang, Zekun; Ding, Yang; Latif, Mahrukh

    2015-05-01

    Multiple myeloma is a disseminated neoplastic monoclonal gammopathy that usually affects the skull, clavicle, rib, pelvis, spinal column, and proximal portions of the humerus and femur. The initial manifestation of multiple myeloma in the sternum is rare. The classic radiological presentations of multiple myeloma are multiple "punched-out" areas of bone destruction, expansile lytic lesions, and generalized osteoporosis. Primary sclerotic presentation is rare and occurs in only 3 % of cases. A sclerotic multiple myeloma with a sunburst periosteal reaction occurring in the sternum has not been reported in the English literature. We report a case of sclerotic multiple myeloma of a 49-year-old woman. In the sternum, the lesion displayed extensive sclerosis mixed with mottled lytic areas with a sunburst periosteal reaction occurring in the periphery, which radiologically mimicked an osteosarcoma. Multiple focal areas of sclerosis were also found in the right clavicle, pelvis, multiple ribs, and vertebrae.

  19. An unusual clinical presentation of eccrine poroma occurring on the auricle

    Directory of Open Access Journals (Sweden)

    Myong Il Bae

    2015-01-01

    Full Text Available Eccrine poromas are benign, slow-growing, solitary tumors originating from the intraepidermal portion of eccrine sweat ducts. Approximately 65% of these tumors occur on the soles of the feet, while 10% occur on the hands where a high concentration of eccrine sweat glands exists. Less frequently it occurs in other sites such as neck, chest, forehead, nose, and scalp with sporadic occurrences. A 43-year-old Korean female presented with a mass on her right auricle, which had been present for 5 years. The mass increased gradually in size with pain, oozing, and bleeding. A biopsy of the mass revealed monomorphic basaloid cells, which may extend into the underlying dermis, in a richly vascularized stroma, with a variable number of cystic or ductal structures. The patient was diagnosed as having eccrine poroma. In this case, the eccrine poroma showed unusual clinical presentation.

  20. Co-occurring disorders in the adolescent mental health and substance abuse treatment systems.

    Science.gov (United States)

    Turner, Win C; Muck, Randolph D; Muck, Rebekah J; Stephens, Robert L; Sukumar, Bhuvana

    2004-12-01

    This article explores the rates of co-occurring disorders in two large federally-funded programs that target youth. In the mental health treatment system, the Substance Abuse and Mental Health Services Administration's (SAMHSA) Center for Mental Health Services (CMHS) supports the Comprehensive Community Mental Health Services for Children and Their Families Program. SAMHSA's Center for Substance Abuse Treatment (CSAT) supports a number of grant programs providing substance abuse treatment for adolescents. The data from these programs underscores the need for the use of systematic, validated, biopsychosocial assessment instruments for all youth entering either the substance abuse or mental health treatment systems. The current evidence base for models of co-occurring treatment for youth is discussed and recommendations made for future activity related to adolescent co-occurring treatment.

  1. Does Parrondo Paradox occur in Scale Free Networks? -A simple Consideration-

    CERN Document Server

    Toyota, Norihito

    2012-01-01

    Parrondo's paradox occurs in sequences of games in which a winning expectation may be obtained by playing the games in a random order, even though each game in the sequence may be lost when played individually. Several variations of Parrondo's games apparently with paradoxical property have been introduced; history dependence, one dimensional line, two dimensional lattice and so on. In this article, we examine whether Parrondo's paradox occurs or not in scale free networks. This is interesting as an empirical study, since scale free networks are ubiquitous in our real world. First some simulation results are given and after that theoretical studies are made. As a result, we mostly confirm that Parrondo's paradox can not occur in the naive case, where the game has the same number of parameters as the original Parrondo's game.

  2. The Interaction Systems Generated by the Teacher's Didactic Imprinting

    Science.gov (United States)

    Peralta, Nadia S.; Roselli, Néstor D.

    2015-01-01

    The current study aimed to identify and analyze the systems of interaction implemented by teachers in university classes, based on their teaching imprints. It focused on the interactions occurred in scholar natural contexts and the construction of knowledge based on said interaction. A form to observe the different behaviors was designed in order…

  3. A typology of affordances: untangling sociomaterial interactions through video analysis

    NARCIS (Netherlands)

    van Osch, W.; Mendelson, O.

    2011-01-01

    In this study we untangle the sociomaterial interactions between developers, users, and artifacts by analyzing what types of affordances occur in the interactions between actors and artifacts in the context of group generativity. Hereto, we conducted an in-depth ethnographic and interaction analysis

  4. The encounter and analysis of naturally occurring radionuclides in gas and oil production and processing

    Energy Technology Data Exchange (ETDEWEB)

    Hartog, F.A.; Jonkers, G.; Knaepen, W.A.I. [Shell Research and Technology Centre, Amsterdam, (Netherlands)

    1996-12-31

    As a result of oil and gas production, radioactive daughter elements from the uranium and thorium decay series can be mobilized and transported away from the reservoir. Due to changes in flow regime, temperature, pressure or chemical environment NORs (Naturally Occurring Radionuclides) may build up in products, by-products or waste streams from gas and oil production and processing facilities. Products containing NORs are commonly denoted by the acronym NORM (Naturally Occurring Radioactive Materials). Main topics of this paper are: E and P (Exploration and Production) NORM characteristics; incentives for NORM analysis; NORM analysis; interlaboratory test programme; analysis techniques; results and conclusions of the test programme. 4 figs., 2 tabs.

  5. Ozone mini-hole occurring over the Tibetan Plateau in December 2003

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    By analyzing the total ozone data from TOMS and ground-based observations, it is found that a large area with extremely low ozone occurred over the Tibetan Plateau during December 14-17, 2003. After correcting the bias in TOMS data, the area with the total ozone < 220 DU is found to be over 2500000 km2, and the minimum value is only 190 DU. It is the first time that an ozone mini-hole or an extremely low ozone event is found to occur over the Tibetan Plateau.

  6. Osteonecrosis of Femoral Head Occurred after Stent Placement of Femoral Artery

    Directory of Open Access Journals (Sweden)

    Akiyoshi Shimatani

    2014-01-01

    Full Text Available We present a case of osteonecrosis of femoral head (ONFH that occurred after stent angiography of femoral artery for the treatment of arteriosclerosis obliterans (ASO of left inferior limb in a 76-year-old woman. No case of late collapse of femoral head as a complication of endovascular procedure such as stent placement has been previously documented. We considered that ONFH occurred after detaining stent at a junction of left deep femoral artery for the treatment of the ischemia of left lateral and medial femoral circumflex artery.

  7. Adaptation-Induced Compression of Event Time Occurs Only for Translational Motion.

    Science.gov (United States)

    Fornaciai, Michele; Arrighi, Roberto; Burr, David C

    2016-03-22

    Adaptation to fast motion reduces the perceived duration of stimuli displayed at the same location as the adapting stimuli. Here we show that the adaptation-induced compression of time is specific for translational motion. Adaptation to complex motion, either circular or radial, did not affect perceived duration of subsequently viewed stimuli. Adaptation with multiple patches of translating motion caused compression of duration only when the motion of all patches was in the same direction. These results show that adaptation-induced compression of event-time occurs only for uni-directional translational motion, ruling out the possibility that the neural mechanisms of the adaptation occur at early levels of visual processing.

  8. Genotoxic activity in vivo of the naturally occurring glucoside, cycasin, in the Drosophila wing spot test.

    Science.gov (United States)

    Kawai, K; Furukawa, H; Hirono, I

    1995-03-01

    Cycasin, methylazoxymethanol-beta-glucoside, is a naturally occurring carcinogenic compound. The genotoxicity of cycasin was assayed in the Drosophila wing spot test. Cycasin induced small single and large single spots on feeding at 10 mumol/g medium. The presence of these spots indicates that cycasin is genotoxic in Drosophila melanogaster. Microorganisms which showed beta-glucosidase activity for cleaving cycasin to toxic aglycon were isolated from gut flora of the Drosophila larvae. Consequently, the Drosophila wing spot test would be useful for mutagenicity screening of other naturally occurring glucosides.

  9. Interactions between the Isolated-Interactive Elements Effect and Levels of Learner Expertise: Experimental Evidence from an Accountancy Class

    Science.gov (United States)

    Blayney, Paul; Kalyuga, Slava; Sweller, John

    2010-01-01

    This study investigated interactions between the isolated-interactive elements effect and levels of learner expertise with first year undergraduate university accounting students. The isolated-interactive elements effect occurs when learning is facilitated by initially presenting elements of information sequentially in an isolated form rather than…

  10. Interactions between the Isolated-Interactive Elements Effect and Levels of Learner Expertise: Experimental Evidence from an Accountancy Class

    Science.gov (United States)

    Blayney, Paul; Kalyuga, Slava; Sweller, John

    2010-01-01

    This study investigated interactions between the isolated-interactive elements effect and levels of learner expertise with first year undergraduate university accounting students. The isolated-interactive elements effect occurs when learning is facilitated by initially presenting elements of information sequentially in an isolated form rather than…

  11. Identification of networks of co-occurring, tumor-related DNA copy number changes using a genome-wide scoring approach.

    Directory of Open Access Journals (Sweden)

    Christiaan Klijn

    2010-01-01

    Full Text Available Tumorigenesis is a multi-step process in which normal cells transform into malignant tumors following the accumulation of genetic mutations that enable them to evade the growth control checkpoints that would normally suppress their growth or result in apoptosis. It is therefore important to identify those combinations of mutations that collaborate in cancer development and progression. DNA copy number alterations (CNAs are one of the ways in which cancer genes are deregulated in tumor cells. We hypothesized that synergistic interactions between cancer genes might be identified by looking for regions of co-occurring gain and/or loss. To this end we developed a scoring framework to separate truly co-occurring aberrations from passenger mutations and dominant single signals present in the data. The resulting regions of high co-occurrence can be investigated for between-region functional interactions. Analysis of high-resolution DNA copy number data from a panel of 95 hematological tumor cell lines correctly identified co-occurring recombinations at the T-cell receptor and immunoglobulin loci in T- and B-cell malignancies, respectively, showing that we can recover truly co-occurring genomic alterations. In addition, our analysis revealed networks of co-occurring genomic losses and gains that are enriched for cancer genes. These networks are also highly enriched for functional relationships between genes. We further examine sub-networks of these networks, core networks, which contain many known cancer genes. The core network for co-occurring DNA losses we find seems to be independent of the canonical cancer genes within the network. Our findings suggest that large-scale, low-intensity copy number alterations may be an important feature of cancer development or maintenance by affecting gene dosage of a large interconnected network of functionally related genes.

  12. Sex Differences in Co-Occurring Conditions of Children with Autism Spectrum Disorders

    Science.gov (United States)

    Stacy, Maria E.; Zablotsky, Benjamin; Yarger, Heather A.; Zimmerman, Andrew; Makia, Barraw; Lee, Li-Ching

    2014-01-01

    This study investigated differences in co-occurring diagnoses made in females compared to males with autism spectrum disorders in 913 children (746 males and 167 females) living in the United States with a current autism spectrum disorder diagnosis identified via caregiver-reported data from the National Survey of Children's Health 2007. The…

  13. Magnolia sulawesiana described, and a key to the species of Magnolia (Magnoliaceae) occurring in Sulawesi

    NARCIS (Netherlands)

    Brambach, F.; Nooteboom, H.P.; Culmsee, H.

    2013-01-01

    Magnolia sulawesiana is described as new species and a modified key of Magnolia subsect. Elmerrillia is included. In addition, a new key of the ten Magnolia species occurring in Sulawesi is provided based on vegetative characters for easy identification in the field.

  14. Effects of Client Bisexuality on Clinical Judgment: When Is Bias Most Likely to Occur?

    Science.gov (United States)

    Mohr, Jonathan J.; Weiner, Jennifer L.; Chopp, Regina M.; Wong, Stephanie J.

    2009-01-01

    In this study, the authors investigated whether psychotherapist bias related to client bisexuality is most likely to occur with respect to judgments about stereotype-relevant clinical issues. Participants were 108 psychotherapists who read a fictitious intake report about a male client who was portrayed as heterosexual, gay, or bisexual. Client…

  15. Determining the parameters at which burnout occurs in the waterwall tubes of drum boilers

    Energy Technology Data Exchange (ETDEWEB)

    I.I. Belyakov [Central Boiler-Turbine Institute Research and Production Association (OAO TsKTI), St. Petersburg (Russian Federation)

    2007-09-15

    Parameters at which burnout occurs are presented that were obtained by measuring the temperature and heat fluxes during experiments carried out directly on a boiler. The results of a comparison between the obtained values and the data of investigations on a test facility are given.

  16. A supplementary list of flowering plants occurring in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    P. Van Wyk

    1971-05-01

    Full Text Available A comprehensive list of the plant species occurring in the Kruger National Park, compiled in the period prior to 1956, was followed by a supplementary list covering additions up to 1960. The present article deals with those species which were discovered from 1960 onwards. Short notes on the habitat and outstanding morphological features of each species are also included.

  17. Drugs, Guns, and Disadvantaged Youths: Co-Occurring Behavior and the Code of the Street

    Science.gov (United States)

    Allen, Andrea N.; Lo, Celia C.

    2012-01-01

    Guided by Anderson's theory of the code of the street, this study explored social mechanisms linking individual-level disadvantage factors with the adoption of beliefs grounded in the code of the street and with drug trafficking and gun carrying--the co-occurring behavior shaping violence among young men in urban areas. Secondary data were…

  18. The Frequency, Nature, and Effects of Naturally Occurring Appearance-Focused Social Comparisons

    Science.gov (United States)

    Leahey, Tricia M.; Crowther, Janis H.; Mickelson, Kristin D.

    2007-01-01

    This research examined the effects of naturally occurring appearance-focused social comparisons on women's affect, body satisfaction, and weight-related cognitions. During their daily activities, women reporting body dissatisfaction (n = 53) and women reporting body satisfaction (n = 34) recorded their reactions to comparison information.…

  19. Pharmacological treatment of schizophrenia and co-occurring substance use disorders.

    Science.gov (United States)

    Smelson, David A; Dixon, Lisa; Craig, Thomas; Remolina, Stephen; Batki, Steven L; Niv, Noosha; Owen, Richard

    2008-01-01

    Substance abuse among individuals with schizophrenia is common and is often associated with poor clinical outcomes. Comprehensive, integrated pharmacological and psychosocial treatments have been shown to improve these outcomes. While a growing number of studies suggest that second-generation antipsychotic medications may have beneficial effects on the treatment of co-occurring substance use disorders, this review suggests that the literature is still in its infancy. Few existing well controlled trials support greater efficacy of second-generation antipsychotics compared with first-generation antipsychotics or any particular second-generation antipsychotic. This article focuses on and reviews studies involving US FDA-approved medications for co-occurring substance abuse problems among individuals with schizophrenia.Comprehensive treatment for individuals with schizophrenia and co-occurring substance use disorders must include specialized, integrated psychosocial intervention. Most approaches use some combination of cognitive-behavioural therapy, motivational enhancement therapy and assertive case management. The research on antipsychotic and other pharmacological treatments is also reviewed, as well as psychosocial treatments for individuals with schizophrenia and co-occurring substance use disorders, and clinical recommendations to optimize care for this population are offered.

  20. First-onset psychosis occurring in the postpartum period: A prospective cohort study

    NARCIS (Netherlands)

    V. Bergink (Veerle); M.P. Lambregtse-van den Berg (Mijke); K.M. Koorengevel (Kathelijne); R.W. Kupka (Ralph ); S.A. Kushner (Steven)

    2011-01-01

    textabstractObjective: To prospectively characterize a cohort of patients for whom first lifetime episode of psychosis occurs in the postpartum period. Method: Included in the study were 51 women admitted to an inpatient facility for postpartum psychosis and a population-based control group (n = 6,9

  1. A library screening approach identifies naturally occurring RNA sequences for a G-quadruplex binding ligand.

    Science.gov (United States)

    Mirihana Arachchilage, Gayan; Morris, Mark J; Basu, Soumitra

    2014-02-07

    An RNA G-quadruplex library was synthesised and screened against kanamycin A as the ligand. Naturally occurring G-quadruplex forming sequences that differentially bind to kanamycin A were identified and characterized. This provides a simple and effective strategy for identification of potential intracellular G-quadruplex targets for a ligand.

  2. 24 CFR 401.502 - Notice requirement when debt restructuring will not occur.

    Science.gov (United States)

    2010-04-01

    ... will not occur. (a) PAE responsibility. If an owner of an eligible project requests a renewal of a section 8 contract without a Restructuring Plan under § 402.4 of this chapter, HUD or the PAE must notify.... The PAE should remove project expense, property valuation, and profit and loss information...

  3. Meiotic behaviour and spermatogenesis in male mice heterozygous for translocation types also occurring in man

    NARCIS (Netherlands)

    Nijhoff, J.H.

    1981-01-01

    In this thesis a start was made with meiotic observations of mouse translocation types - a Robertsonian translocation and a translocation between a metacentric and an acrocentric chromosome - which also occur in man. It is generally accepted that, when no chromosomal rearrangements are involved, man

  4. Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species

    Science.gov (United States)

    Frederick Meinzer; David Woodruff; Danielle Marias; Katherine McCulloh; Sanna Sevanto

    2014-01-01

    Because iso- and anisohydric species differ in stomatal regulation of the rate and magnitude of fluctuations in shoot water potential, they may be expected to show differences in the plasticity of their shoot water relations components, but explicit comparisons of this nature have rarely been made. We subjected excised shoots of co-occurring anisohydric Juniperus...

  5. A One Year Prospective Study of Neurogenic Stuttering Following Stroke: Incidence and Co-Occurring Disorders

    Science.gov (United States)

    Theys, C.; van Wieringen, A.; Sunaert, S.; Thijs, V.; De Nil, L. F.

    2011-01-01

    In this prospective study, data on incidence, stuttering characteristics, co-occurring speech disorders, and recovery of neurogenic stuttering in a large sample of stroke participants were assessed. Following stroke onset, 17 of 319 participants (5.3%; 95% CI, 3.2-8.3) met the criteria for neurogenic stuttering. Stuttering persisted in at least…

  6. Heterogeneity in autism spectrum disorder: clarifying core- and co-occurring characteristics, correlates and course

    NARCIS (Netherlands)

    M.L.J.M. Eussen (Mart)

    2015-01-01

    markdownabstractThe first aim of this thesis is to gain more insight in the phenotypical variance of core and eo-occurring symptoms of ASD. The specific research questions concerning this first aim are: 1. Do symptom profiles on core ASD symptoms support a categorical view with different

  7. Modified Therapeutic Community Treatment for Offenders with Co-Occurring Disorders: Mental Health Outcomes

    Science.gov (United States)

    Sullivan, Christopher J.; Sacks, Stanley; McKendrick, Karen; Banks, Steven; Sacks, Joann Y.; Stommel, Joseph

    2007-01-01

    This paper examines outcomes 12 months post-prison release for offenders with co-occurring disorders (n = 185) randomly assigned to either a mental health control treatment (C) or a modified therapeutic community (E). Significant between-group differences were not found for mental health measures, although improvements were observed for each…

  8. Concentrations of the naturally occurring radionucleides Pb-210, Po-210, and Ra-226 in aquatic fauna

    Science.gov (United States)

    Holtzman, R. B.

    1969-01-01

    Study reveals naturally occurring radionuclides are ubiquitous and contribute a substantial fraction of the natural radiation dose to humans and various biota. Measurements may be useful in ecological and other biological problems such as tracing food chains of animals and study of the metabolism of these elements.

  9. Co-Occurring Psychiatric and Substance Dependence Disorders as Predictors of Parolee Time to Rearrest

    Science.gov (United States)

    Wood, Steven R.

    2011-01-01

    An estimated 500,000-plus people are on parole each year, many with serious co-occurring psychiatric and substance use disorders. Using cross sectional, self-report data this study examined the relationships between parolee time to rearrest, serious mental illnesses, and substance dependency (n = 1,121). Regression analyses indicated that after…

  10. Combinatorics and Probability: Six- to Ten-Year-Olds Reliably Predict Whether a Relation Will Occur

    Science.gov (United States)

    Gonzalez, Michel; Girotto, Vittorio

    2011-01-01

    Young children are able to judge which of two possibilities is more likely to occur when these possibilities are characterized by a simple property, like color ("Is it more likely to draw a red chip or a blue chip?"). Here we ask whether they can do so when the possibilities concern a relation between simple properties ("Is it more likely to draw…

  11. A One Year Prospective Study of Neurogenic Stuttering Following Stroke: Incidence and Co-Occurring Disorders

    Science.gov (United States)

    Theys, C.; van Wieringen, A.; Sunaert, S.; Thijs, V.; De Nil, L. F.

    2011-01-01

    In this prospective study, data on incidence, stuttering characteristics, co-occurring speech disorders, and recovery of neurogenic stuttering in a large sample of stroke participants were assessed. Following stroke onset, 17 of 319 participants (5.3%; 95% CI, 3.2-8.3) met the criteria for neurogenic stuttering. Stuttering persisted in at least…

  12. Drugs, Guns, and Disadvantaged Youths: Co-Occurring Behavior and the Code of the Street

    Science.gov (United States)

    Allen, Andrea N.; Lo, Celia C.

    2012-01-01

    Guided by Anderson's theory of the code of the street, this study explored social mechanisms linking individual-level disadvantage factors with the adoption of beliefs grounded in the code of the street and with drug trafficking and gun carrying--the co-occurring behavior shaping violence among young men in urban areas. Secondary data were…

  13. 42 CFR 433.316 - When discovery of overpayment occurs and its significance.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false When discovery of overpayment occurs and its... and its significance. (a) General rule. The date on which an overpayment is discovered is the... action against a provider without first giving written notification of its intent, a State...

  14. Correlates of Pure and Co-Occurring Proactive and Reactive Aggressors In Hong Kong

    Science.gov (United States)

    Chan, Jacob Yuichung; Fung, Annis L.; Gerstein, Lawrence H.

    2013-01-01

    Research on aggression in the West has focused mainly on the dichotomy between proactive and reactive aggression, but not the co-occurring proactive-reactive aggression subtype, despite its prevalence. The authors investigated the differences in psychological and behavioral correlates among proactive, reactive, and proactive-reactive student…

  15. Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes

    CERN Document Server

    Marinov, A; Kashiv, Y; Halicz, L; Segal, I; Pape, A; Gentry, R V; Miller, H W; Kolb, D; Brandt, R

    2006-01-01

    Evidence for the existence of long-lived neutron-deficient isotopes has been found in a study of naturally-occurring Th using iductively coupled plasma-sector field mass spectrometry. They are interpreted as belonging to the recently discovered class of long-lived high spin super- and hyperdeformed isomers.

  16. Treatment of Co-Occurring Substance Abuse and Suicidality among Adolescents: A Randomized Trial

    Science.gov (United States)

    Esposito-Smythers, Christianne; Spirito, Anthony; Kahler, Christopher W.; Hunt, Jeffrey; Monti, Peter

    2011-01-01

    Objective: This study tested a cognitive-behavioral treatment protocol for adolescents with a co-occurring alcohol or other drug use disorder (AOD) and suicidality in a randomized clinical trial. Method: Forty adolescents (M[subscript age] = 15 years; 68% female, 89% White) and their families recruited from an inpatient psychiatric hospital were…

  17. CBL mutations do not frequently occur in paediatric acute myeloid leukaemia

    NARCIS (Netherlands)

    Coenen, Eva A.; Driessen, Emma M. C.; Zwaan, C. Michel; Stary, Jan; Baruchel, Andre; de Haas, Valerie; de Bont, Eveline S. J. M.; Reinhardt, Dirk; Kaspers, Gertjan J. L.; Arentsen-Peters, Susan T. C. J. M.; Meyer, Claus; Marschalek, Rolf; Pieters, Rob; Stam, Ronald W.; van den Heuvel-Eibrink, Marry M.

    2012-01-01

    RAS-pathway mutations, causing a proliferative advantage, occur in acute myeloid leukaemia (AML) and MLL-rearranged leukaemia. Recently, mutations in the Casitas B lineage lymphoma (CBL) gene were reported to be involved in RAS-pathway activation in various myeloid malignancies, but their role in pa

  18. BIOCONVERSION OF NATURALLY-OCCURRING PRECURSORS AND RELATED SYNTHETIC COMPOUNDS USING PLANT-CELL CULTURES

    NARCIS (Netherlands)

    PRAS, N

    1992-01-01

    The nearly unlimited enzymatic potential of cultured plant cells can basically be employed for bioconversion purposes. Plant enzymes are able to catalyze regio- and stereospecific reactions and can therefore be applied to the production of compounds of pharmaceutical interest. Naturally occurring as

  19. Why Hyperbonding Occurs in the Learning Community Classroom and What to Do about It

    Science.gov (United States)

    Watts, Julie

    2013-01-01

    Hyperbonding can be a disruptive force in the learning community classroom characterized by nonproductive student behaviors. Research has not identified how frequently hyperbonding occurs in learning communities or why. However, studies have begun to link hyperbonding to the presence of cohorts. I explain how cohorts form and develop, and how they…

  20. A case of polymicrobial infective endocarditis involving Neisseria mucosa occurring in an intravenous drug abuser.

    Science.gov (United States)

    Giles, M W; Andrew, J H; Tellus, M M

    1988-12-01

    The incidence of polymicrobial endocarditis has increased markedly in recent years, in association with the increasing level of abuse of intravenous drugs. Neisseria mucosa, an upper respiratory tract commensal, is a rare cause of infective endocarditis. We report the first case of polymicrobial infective endocarditis involving Neisseria mucosa occurring in an intravenous drug abuser.

  1. Naturally occurring products of proglucagon 111-160 in the porcine and human small intestine

    DEFF Research Database (Denmark)

    Buhl, T; Thim, L; Kofod, Hans

    1988-01-01

    Recent studies have revealed that the glucagon gene is expressed in the mammalian intestine. Here it codes for "glicentin" (proglucagon 1-69) and a glucagon-like peptide, proglucagon 78-107, recently isolated from porcine intestine. We studied the fate of the remaining COOH-terminal part of progl...... that this is the structure of the naturally occurring human peptide....

  2. Predictors of suicides occurring within suicide clusters in Australia, 2004-2008.

    Science.gov (United States)

    Derek Cheung, Yee Tak; Spittal, Matthew J; Williamson, Michelle Kate; Tung, Sui Jay; Pirkis, Jane

    2014-10-01

    A number of studies have investigated the presence of suicide clusters, but few have sought to identify risk and protective factors of a suicide occurring within a cluster. We aimed to identify socio-demographic and contextual characteristics of suicide clusters from national and regional analyses of suicide clusters. We searched the National Coroners Information System for all suicides in Australia from 2004 to 2008. Scan statistics were initially used to identify those deaths occurring within a spatial-temporal suicide cluster during the period. We then used logistic regression and generalized estimation equations to estimate the odds of each suicide occurring within a cluster differed by sex, age, marital status, employment status, Indigenous status, method of suicide and location. We identified 258 suicides out of 10,176 suicides during the period that we classified as being within a suicide cluster. When the deceased was Indigenous, living outside a capital city, or living in the northern part of Australia (in particular, Northern Territory, Queensland and Western Australia) then there was an increased likelihood of their death occurring within a suicide cluster. These findings suggest that suicide clustering might be linked with geographical and Indigenous factors, which supported sociological explanations of suicide clustering. This finding is significant for justifying resource allocation for tackling suicide clustering in particular areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Co-Occurring Psychiatric and Substance Dependence Disorders as Predictors of Parolee Time to Rearrest

    Science.gov (United States)

    Wood, Steven R.

    2011-01-01

    An estimated 500,000-plus people are on parole each year, many with serious co-occurring psychiatric and substance use disorders. Using cross sectional, self-report data this study examined the relationships between parolee time to rearrest, serious mental illnesses, and substance dependency (n = 1,121). Regression analyses indicated that after…

  4. Predictors of Competitive Employment among Consumers with Co-Occurring Mental and Substance Use Disorders

    Science.gov (United States)

    Biegel, David E.; Stevenson, Lauren D.; Beimers, David; Ronis, Robert J.; Boyle, Patrick

    2010-01-01

    Objectives: This study examines consumer and agency level predictors of competitive employment for consumers with co-occurring disorders. Methods: The study sample included 191 consumers from mental health agencies receiving Integrated Dual Diagnosis Treatment services, including a subgroup which was referred for Supported Employment Services.…

  5. Investigation of interface boundary occurring during cold gas-dynamic spraying of metallic particles

    CERN Document Server

    Bolesta, A V; Sharafutdinov, M R; Tolochko, B P

    2001-01-01

    An interface boundary occurring during cold gas dynamic spraying of aluminum particles on a nickel substrate has been studied by the method of X-ray grazing diffraction. Presence of boundary phase of the intermetallic compound Ni sub 3 Al was found.

  6. Therapeutic Recreation in the Naturally Occurring Retirement Community (NORC): Benefitting "Aging in Place."

    Science.gov (United States)

    Kunstler, Robin

    2002-01-01

    Describes how therapeutic recreation in naturally occurring retirement communities (neighborhoods where most residents are older) can promote healthy lifestyles, presenting a case report of an in-home therapeutic recreation program offered in conjunction with nursing and social services in a such a community and discussing implications for…

  7. Mining Aboriginal Labour: Examining Capital Reconversion Strategies Occurring on the Risk Management Field

    Science.gov (United States)

    Hodgkins, Andrew P.

    2016-01-01

    This article examines a vocational education and training partnership occurring in the Canadian oil sands mining industry. The case study involves a corporate-sponsored pre-apprenticeship training programme designed to procure aboriginal labour in the province of Alberta. Interviews with members of key partner groups and stakeholders occurred…

  8. Naturally occurring radionuclides in pasture soil, feed ingredients and milk of dairy cattle

    Energy Technology Data Exchange (ETDEWEB)

    Turtiainen, T.; Kostiainen, E.; Solatie, D. [STUK-Radiation and Nuclear Safety Authority (Finland)

    2014-07-01

    Naturally occurring radionuclides are generally considered being respective part of the environment and hence no statutory monitoring of their levels are required in food products. Therefore, limited data are available on the naturally occurring radionuclides in food. Dairy products constitute a significant portion of Finnish diet (400-500 g/d) and hence it is reasonable to study radionuclide levels in milk in more detail. Contrary to caesium, strontium and iodine, few transfer coefficients are available in the literature for naturally occurring radionuclide transfer to cow's milk. The renaissance of mining industry in Finland has raised a question among the public about the baseline values of naturally occurring radionuclides in Finnish agricultural products. The objective of this study was to investigate naturally occurring radionuclides in the components of dairy cattle diet and milk and calculate their transfer to milk. This information is needed for regulating the permitted discharges to the environment and for setting up monitoring programs if any unplanned discharges are released. In modern dairy farming, cattle are fed a precise diet in order to maximize milk production and quality and to achieve cost-effectiveness. Therefore, several different components are found in dairy cattle's diet and pasture grass concentrations are not sufficient for calculating radionuclide transfer to cow's milk. In this study, we carried out comprehensive sampling at four dairy farms each representing different areas of natural radiation background. The pasture soils were characterized and measured for natural radioactivity. Samples were taken from cattle's total diet (including e.g. pasture grass, water, silage, mineral forage) and milk. Document available in abstract form only. (authors)

  9. Why does Amphibian Chytrid (Batrachochytrium dendrobatidis) not occur everywhere? An exploratory study in Missouri ponds.

    Science.gov (United States)

    Strauss, Alex; Smith, Kevin G

    2013-01-01

    The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is a globally emerging pathogen that has caused widespread amphibian population declines, extirpations, and extinctions. However, Bd does not occur in all apparently suitable amphibian populations, even within regions where it is widespread, and it is often unclear why Bd occurs in some habitats but not others. In this study, we rigorously surveyed the amphibian and invertebrate biodiversity of 29 ponds in Missouri, screened resident amphibian larvae (Rana (Lithobates) sp.) for Bd infection, and characterized the aquatic physiochemical environment of each pond (temperature pH, conductivity, nitrogen, phosphorus, and chlorophyll-a). Our goal was to generate hypotheses toward answering the question, "Why does Bd not occur in all apparently suitable habitats?" Bd occurred in assayed amphibians in 11 of the 29 ponds in our study area (38% of ponds). We found no significant relationship between any single biotic or abiotic variable and presence of Bd. However, multivariate analyses (nonmetric multidimensional scaling and permutational tests of dispersion) revealed that ponds in which Bd occurred were a restricted subset of all ponds in terms of amphibian community structure, macroinvertebrate community structure, and pond physiochemistry. In other words, Bd ponds from 6 different conservation areas were more similar to each other than would be expected based on chance. The results of a structural equation model suggest that patterns in the occurrence of Bd among ponds are primarily attributable to variation in macroinvertebrate community structure. When combined with recent results showing that Bd can infect invertebrates as well as amphibians, we suggest that additional research should focus on the role played by non-amphibian biota in determining the presence, prevalence, and pathogenicity of Bd in amphibian populations.

  10. Why does Amphibian Chytrid (Batrachochytrium dendrobatidis not occur everywhere? An exploratory study in Missouri ponds.

    Directory of Open Access Journals (Sweden)

    Alex Strauss

    Full Text Available The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd, is a globally emerging pathogen that has caused widespread amphibian population declines, extirpations, and extinctions. However, Bd does not occur in all apparently suitable amphibian populations, even within regions where it is widespread, and it is often unclear why Bd occurs in some habitats but not others. In this study, we rigorously surveyed the amphibian and invertebrate biodiversity of 29 ponds in Missouri, screened resident amphibian larvae (Rana (Lithobates sp. for Bd infection, and characterized the aquatic physiochemical environment of each pond (temperature pH, conductivity, nitrogen, phosphorus, and chlorophyll-a. Our goal was to generate hypotheses toward answering the question, "Why does Bd not occur in all apparently suitable habitats?" Bd occurred in assayed amphibians in 11 of the 29 ponds in our study area (38% of ponds. We found no significant relationship between any single biotic or abiotic variable and presence of Bd. However, multivariate analyses (nonmetric multidimensional scaling and permutational tests of dispersion revealed that ponds in which Bd occurred were a restricted subset of all ponds in terms of amphibian community structure, macroinvertebrate community structure, and pond physiochemistry. In other words, Bd ponds from 6 different conservation areas were more similar to each other than would be expected based on chance. The results of a structural equation model suggest that patterns in the occurrence of Bd among ponds are primarily attributable to variation in macroinvertebrate community structure. When combined with recent results showing that Bd can infect invertebrates as well as amphibians, we suggest that additional research should focus on the role played by non-amphibian biota in determining the presence, prevalence, and pathogenicity of Bd in amphibian populations.

  11. Intervening to reduce workplace sitting time: how and when do changes to sitting time occur?

    Science.gov (United States)

    Stephens, Samantha K; Winkler, Elisabeth A H; Trost, Stewart G; Dunstan, David W; Eakin, Elizabeth G; Chastin, Sebastien F M; Healy, Genevieve N

    2014-07-01

    To investigate how and when changes in workplace sitting time occurred following a workplace intervention to inform evaluation of intervention success. The 4-week Stand Up Comcare study (June-September 2011) aimed to reduce workplace sitting time via regularly interrupting and replacing sitting time throughout the day. Activity monitor (activPAL3) workplace data from control (n=22) and intervention participants (n=21) were analysed. Differences in the number and usual duration of sitting bouts were used to evaluate how change occurred. To examine when change occurred, intervention effects were compared by hour since starting work and hour of the workday. Change in workplace activity (sitting, standing, stepping) was examined to further inform alignment with intervention messages. Individual variability was examined in how and when the change occurred. Overall, behavioural changes aligned with intervention aims. All intervention participants reduced total workplace sitting time, though there was wide individual variability observed (range -29 to -262 min per 8 h workday). On average, intervention participants reduced number of sitting bouts (-4.6 bouts (95% CI -10.1 to 1.0), p=0.106) and usual sitting bout duration (-5.6 min (95% CI -9.8 to -1.4, p=0.011)) relative to controls. Sitting time reductions were observed across the workday, though intervention effects varied by hour of the day (p=0.015). The intervention group successfully adopted the Stand Up and Sit Less intervention messages across the day. These analyses confirmed that this workplace intervention successfully modified sitting behaviour as intended (ie, fewer and shorter sitting bouts, with changes occurring throughout the day). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. Electron correlation by polarization of interacting densities

    CERN Document Server

    Whitten, Jerry L

    2016-01-01

    Coulomb interactions that occur in electronic structure calculations are correlated by allowing basis function components of the interacting densities to polarize, thereby reducing the magnitude of the interaction. Exchange integrals of molecular orbitals are not correlated. The modified Coulomb interactions are used in single-determinant or configuration interaction calculations. The objective is to account for dynamical correlation effects without explicitly introducing higher spherical harmonic functions into the molecular orbital basis. Molecular orbital densities are decomposed into a distribution of spherical components that conserve the charge and each of the interacting components is considered as a two-electron wavefunction embedded in the system acted on by an average field Hamiltonian plus . A method of avoiding redundancy is described. Applications to atoms, negative ions and molecules representing different types of bonding and spin states are discussed.

  13. Preheating with Trilinear Interactions: Tachyonic Resonance

    CERN Document Server

    Dufaux, J F; Kofman, L; Peloso, M; Podolsky, D

    2006-01-01

    We investigate the effects of bosonic trilinear interactions in preheating after chaotic inflation. A trilinear interaction term allows for the complete decay of the massive inflaton particles, which is necessary for the transition to radiation domination. We found that typically the trilinear term is subdominant during early stages of preheating, but it actually amplifies parametric resonance driven by the four-legs interaction. In cases where the trilinear term does dominate during preheating, the process occurs through periodic tachyonic amplifications with resonance effects, which is so effective that preheating completes within a few inflaton oscillations. We develop an analytic theory of this process, which we call tachyonic resonance. We also study numerically the influence of trilinear interactions on the dynamics after preheating. The trilinear term eventually comes to dominate after preheating, leading to faster rescattering and thermalization than could occur without it. Finally, we investigate the...

  14. A Group Awaiting Death: The Social Systems Perspective on a Naturally Occurring Group Situation.

    Science.gov (United States)

    Starker, Steven; Starker, Joan E.

    1982-01-01

    Uses social systems theory to analyze the interaction of an informal group of family and friends formed around an individual in an intensive care unit. Discusses contributors to dissension including ambiguity of the task structure, fluidity of leadership and power, and failure of a utopian defense. (Author/JAC)

  15. Drug Interaction API

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Interaction API is a web service for accessing drug-drug interactions. No license is needed to use the Interaction API. Currently, the API uses DrugBank for its...

  16. ANALYSIS ON THE DEEP SEATED LANDSLIDE OCCURRED IN SHAOLIN VILLEGE, KAOHSIUNG COUNTY, TAIWAN

    Science.gov (United States)

    Tsutsumi, Daizo; Fujita, Masaharu; Miyamoto, Kuniaki; Imaizumi, Fumitoshi; Fujimoto, Masamitsu; Kokuryo, Hiroshi; Izumiyama, Hiroaki

    In August 2009, the Typhoon Morakot hit Taiwan and caused an extraordinary amount of rainfall. Due to the heavy rainfall, a large number of floods and sediment-related disasters occurred all over the island. In Shaolin Village, Kaohsiung County, a huge landslide occurred around 6 am August 9, destroyed the village completely and killed more than 500 people. After the landslide, authors visited the landslide site and investigated the landslide scour to collect information on factors affecting landslide occurrence such as exposed bedrock and soil layer conditions. GIS analysis using DEM data were also conducted to determine the sliding domain. According to the site investigation and GIS analysis, rainwater infiltration analysis and slope stability analysis were conducted. Results of the analysis suggested that the landslide domain, about 1,200 m long, 500 m wide and 80 m deep was collapsed by multi phased manner.

  17. Prospective trial of metronomic chlorambucil chemotherapy in dogs with naturally occurring cancer.

    Science.gov (United States)

    Leach, T N; Childress, M O; Greene, S N; Mohamed, A S; Moore, G E; Schrempp, D R; Lahrman, S R; Knapp, D W

    2012-06-01

    The purpose of this study was to assess the toxicoses and antitumor activity of metronomic chlorambucil at a dosage of 4 mg m(-2) daily in dogs with naturally occurring cancer. Thirty-six dogs were enrolled in the study. The protocol was well tolerated with no grade 3 or 4 toxicoses noted. Complete remission was achieved, and lasted over 35 weeks in three dogs (mast cell tumour, soft tissue sarcoma and thyroid carcinoma). Partial remission was noted in 1 dog with histiocytic sarcoma (39 weeks duration) for an overall remission rate of 11% (4 of 36). Stable disease was noted in 17 dogs (47%) with various other cancers. The median progression-free interval was 61 days, and the median survival time was 153 days. Chlorambucil given in a metronomic protocol showed antitumor activity in dogs with a variety of naturally occurring cancers.

  18. A cognitive behavioral therapy for co-occurring substance use and posttraumatic stress disorders.

    Science.gov (United States)

    McGovern, Mark P; Lambert-Harris, Chantal; Acquilano, Stephanie; Xie, Haiyi; Alterman, Arthur I; Weiss, Roger D

    2009-10-01

    Co-occurring posttraumatic stress disorder (PTSD) is prevalent in addiction treatment programs and a risk factor for negative outcomes. Although interventions have been developed to address substance use and PTSD, treatment options are needed that are effective, well tolerated by patients, and potentially integrated with existing program services. This paper describes a cognitive behavioral therapy (CBT) for PTSD that was adapted from a treatment for persons with severe mental illnesses and PTSD in community mental health settings. The new adaptation is for patients in community addiction treatment with co-occurring PTSD and substance use disorders. In this study, 5 community therapists delivered the CBT for PTSD. Outcome data are available on 11 patients who were assessed at baseline, post-CBT treatment, and at a 3-month follow-up post-treatment. Primary outcomes were substance use, PTSD severity, and retention, of which all were favorable for patients receiving the CBT for PTSD.

  19. Optimal Control Policy for Environment withScience and Technology Stochastic Occur

    Institute of Scientific and Technical Information of China (English)

    MinggaoXue; ChulinLi; PuGong

    2004-01-01

    In this paper, the control policy for environment with two kinds of irreversibility, which work in opposite directions and uncertainty of cost is regarded as an investment decision. By using real-option theory, the paper presents the model of the optimal control policy for environment under the science and technology that can reduce environment pollution stochastic occur. The paper has discussed the effects of changes in the various parameters on the critical value at which the policy should be adopted. The results show thatthe optimal control policy is quite sensitive to the science and technology which can reduce environment pollution stochastic occur, pointing to the importance of carefully accounting for its impact in determining the control policy for environment.

  20. Left atrial volume and function in dogs with naturally occurring myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Höllmer, M.; Willesen, J. L.; Tolver, A.

    2017-01-01

    of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD. ANIMALS: This prospective study included 205 client-owned dogs of different breeds, 114...... healthy dogs, and 91 dogs with MMVD of different disease severities. METHODS: Using two-dimensional echocardiography, the biplane area-length method was applied to assess LA volume and calculate volumetric indices of LA reservoir, conduit, and contractile function. RESULTS: Left atrial volume and LA...... stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100...

  1. Concurrent cryptococcal meningitis and disseminated tuberculosis occurring in an immunocompetent male.

    Science.gov (United States)

    Musabende, Marcellin; Mukabatsinda, Constance; Riviello, Elisabeth D; Ogbuagu, Onyema

    2016-02-25

    A 61-year-old man living in rural Rwanda presented with a 2-month history of fevers, headaches, dry cough, weight loss and confusion. A cerebrospinal fluid analysis revealed neutrophilic pleocytosis, yeast and a positive cryptococcal antigen (CrAg). An HIV antibody test was negative. The patient's cough worsened while on antifungal induction therapy with intravenous conventional amphotericin B and high-dose oral fluconazole. Computerised tomography (CT) scan of the chest showed extensive miliary infiltrates. Bronchoalveolar lavage revealed acid-fast bacilli on smear and a positive GeneXpert test without rifampicin resistance. The patient improved with the addition of antitubercular therapy. In this case report, we describe an unusual presentation of two opportunistic infections occurring together in an HIV-negative man with no other known immunocompromising conditions. The case highlights the fact that, in disease endemic areas, multiple disseminated infections can occur in individuals without obvious immunocompromise.

  2. Robust stabilisation of 2D state-delayed stochastic systems with randomly occurring uncertainties and nonlinearities

    Science.gov (United States)

    Duan, Zhaoxia; Xiang, Zhengrong; Karimi, Hamid Reza

    2014-07-01

    This paper is concerned with the state feedback control problem for a class of two-dimensional (2D) discrete-time stochastic systems with time-delays, randomly occurring uncertainties and nonlinearities. Both the sector-like nonlinearities and the norm-bounded uncertainties enter into the system in random ways, and such randomly occurring uncertainties and nonlinearities obey certain mutually uncorrelated Bernoulli random binary distribution laws. Sufficient computationally tractable linear matrix inequality-based conditions are established for the 2D nonlinear stochastic time-delay systems to be asymptotically stable in the mean-square sense, and then the explicit expression of the desired controller gains is derived. An illustrative example is provided to show the usefulness and effectiveness of the proposed method.

  3. Recovery curves of the lightning discharges occurring in the dissipation stage of thunderstorms

    Indian Academy of Sciences (India)

    S D Pawar; A K Kamra

    2013-04-01

    Measurements of atmospheric electric field made below two thunderstorms show that all lightning discharges occurring in the dissipating stage of a thunderstorm occur at almost the same value of the predischarge electric field at the ground surface. The observation is explained on the basis of the shielding of the electric fields generated by the positive charge in the downdrafts by the negative charge in the screening layers formed around them in the subcloud layer. Our observations suggest that in the dissipating stage of the thunderstorm, the charge generating mechanisms in cloud have ceased to operate and the charge being transported from the upper to lower regions of cloud by downdrafts is the only in-cloud process affecting the surface electric field and/or enhancing the electric field stress in and below the cloud base to cause yet another lightning discharge.

  4. Monitoring of increased natural occuring radiation exposure; Arbeitsplatzueberwachung bei erhoehter natuerlicher Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Guhr, Andreas [ALTRAC Radon-Messtechnik, Berlin (Germany); Leissring, Nick [Bergtechnisches Ingenieurbuero GEOPRAX, Chemnitz (Germany)

    2015-07-01

    The radiation exposure due to natural occurring sources is a special challenge for the health and safety protection at workplaces. The monitoring of the radon exposure of employees in mines, radon-spa and in water works is regulated by prescription of radiation protection. The relevant compounds of the radiation exposure are the inhalation of radon and radon daughter products; terrestrial irradiation; ingestion of radioactive contaminated materials and the inhalation of contaminated dust. The monitoring of the radiation workers is realized essentially by measurements by radiation safety officer of the performing company, by an external engineering firm as well as by control measurements of experts of local authorities. The experiences in the practice have shown that in the field of operational radiation protection only a combination of personal- and operational dosimetry is suitable to avoid health hazards by work in fields with increased natural occurring radiation exposures.

  5. Estimating the continuous risk of accidents occuring in the mining industry in South Africa

    Directory of Open Access Journals (Sweden)

    Van den Honert, Andrew Francis

    2015-11-01

    Full Text Available This study contributes to the on-going efforts to improve occupational safety in the mining industry by creating a model capable of predicting the continuous risk of occupational accidents occurring. Contributing factors were identified and their sensitivity quantified. The approach included using an Artificial Neural Network (ANN to identify patterns between the input attributes and to predict the continuous risk of accidents occurring. The predictive Artificial Neural Network (ANN model used in this research was created, trained, and validated in the form of a case study with data from a platinum mine near Rustenburg in South Africa. This resulted in meaningful correlation between the predicted continuous risk and actual accidents.

  6. Fibrous dysplasia: rapid malignant transformation into osteogenic sarcoma - A rare occurance

    Directory of Open Access Journals (Sweden)

    S Gon

    2012-09-01

    Full Text Available Malignant transformation of fibrous dysplasia is rare, occurring in less than 1% of cases with a mean lag period of 13.5 years. We report a case of Osteogenic Sarcoma with chondroid differentiation in a pre-existing Fibrous Dysplasia occurring within one year of surgical resection and without any history of exposure to radiation. To the best of our knowledge and extensive search of literature, malignant transformation of Fibrous Dysplasia in such a short period of time, and without history of radiation exposure has never been reported from India.Journal of Pathology of Nepal (2012 Vol. 2, 335-337DOI: http://dx.doi.org/10.3126/jpn.v2i4.6891

  7. Sensitivity, child regulatory processes, and naturally occurring declines in antisocial behavior across childhood.

    Science.gov (United States)

    Buck, Katharine Ann

    2014-12-01

    Despite considerable research on why antisocial behavior develops and interventions that reduce it, aspects of everyday family processes that may promote naturally occurring declines in antisocial behavior or that may result from such declines in most children without intervention are poorly understood. The current study explored family processes that may enable children to replace antisocial tendencies and the effects that declines in antisocial behavior may have on parenting and child regulatory processes. Longitudinal data from 1,022 children (54 months-6th grade) from the NICHD Study of Early Child Care and Youth Development were examined. Findings demonstrated that naturally occurring declines in antisocial behavior both predicted and were predicted by maternal sensitivity, emotion regulation, and social skills. These declines predicted but were not predicted by declines in hostile attributions. The data revealed multiple indirect paths, which highlight the complex nature of these variables across development.

  8. Risk of future offense among probationers with co-occurring substance use and mental health disorders.

    Science.gov (United States)

    Balyakina, Elizabeth; Mann, Christopher; Ellison, Michael; Sivernell, Ron; Fulda, Kimberly G; Sarai, Simrat Kaur; Cardarelli, Roberto

    2014-04-01

    The criminal justice system is the primary service delivery system for many adults with drug and alcohol dependence, mental health, and other health service needs. The purpose of this study was to examine the relationship between risk of future offense, mental health status and co-occurring disorders in a large substance abuse diversion probationer population. A purposive sample of 2,077 probationers completed an assessment to screen for mental health disorders, substance use disorders, risk of future crime and violence, and several demographic characteristics. Probationers who screened positive for co-occurring substance use and mental health disorders were significantly more likely to be at higher risk of future crime and violence compared to probationers who screened positive for only substance use, only a mental health disorder, or no substance use or mental health disorder. Implications for substance use and mental health service delivery are discussed, and recommendations are made for further research.

  9. Extraction and characterization of naturally occurring bioactive peptides from different tissues from Salmon (Salmo salar)

    DEFF Research Database (Denmark)

    Falkenberg, Susan Skanderup; Nielsen, Henrik Hauch

    2011-01-01

    is therefore to extract and identify naturally occurring bioactive peptides from different tissues from salmon. A number of aqueous extracts were made from gills, skin and belly flap. In order to preserve the bioactivity of the peptides mild extraction procedures as acidic, basic and aqueous solutions were...... number of bio-components such as bioactive peptides for this purpose. Tissue and proteins from e.g. fish gills, skin and viscera could be a new source of peptides that could have a nutritional and pharmaceutical value, and be used in health and functional foods and thereby increasing the value adding...... of secondary marine products. Only few naturally occurring bioactive peptides have been characterized such as the antimicrobial polypeptide piscidines from gills. It is therefore hypothesized, that fish tissue also contains numerous other peptides with other bioactive properties. The approach in this project...

  10. The influence of selected socio-demographic variables on symptoms occurring during the menopause

    OpenAIRE

    Marta Makara-Studzińska; Karolina Kryś-Noszczyką; Grzegorz Jakiel

    2015-01-01

    Introduction: It is considered that the lifestyle conditioned by socio-demographic or socio-economic factors determines the health condition of people to the greatest extent. The aim of this study is to evaluate the influence of selected socio-demographic factors on the kinds of symptoms occurring during menopause. Material and methods : The study group consisted of 210 women aged 45 to 65, not using hormone replacement therapy, staying at healthcare centers for rehabilitation treatment...

  11. Recombinant feline leukemia virus genes detected in naturally occurring feline lymphosarcomas.

    OpenAIRE

    Sheets, R L; Pandey, R.; Jen, W C; Roy-Burman, P

    1993-01-01

    Using a polymerase chain reaction strategy aimed at detecting recombinant feline leukemia virus (FeLV) genomes with 5' env sequences originating from an endogenous source and 3' env sequences resulting from FeLV subgroup A (FeLV-A), we detected recombinant proviruses in approximately three-fourths of naturally occurring thymic and alimentary feline lymphosarcomas (LSAs) and one-third of the multicentric LSAs from cats determined to be FeLV capsid antigen positive by immunofluorescence assay. ...

  12. Adaption of an Antarctic lichen to Martian niche conditions can occur within 34 days

    OpenAIRE

    de Vera, J. P.; Schulze-Makuch, D.; Khan, A; Lorek, A.; Möhlmann, D.; T. Spohn

    2014-01-01

    Stresses occurring on the Martian surface were simulated in a Mars Simulation Chamber (MSC) and included high UV fluxes (Zarnecki andCatling,2002), low temperatures, low water activity, high atmospheric CO2 concentrations, and an atmospheric pressure of about 800Pa (Kasting, 1991; Head etal., 2003). The lichen Pleopsidium chlorophanum is an extremophile that lives in very cold, dry, high-altitude habitats, which are Earth's best approximation of the Martian surface. Samples with P.ch...

  13. A cognitive behavioral therapy for co-occurring substance use and posttraumatic stress disorders

    OpenAIRE

    McGovern, Mark P.; Lambert-Harris, Chantal; Acquilano, Stephanie; Xie, Haiyi; Alterman, Arthur I.; Weiss, Roger D.

    2009-01-01

    Co-occurring posttraumatic stress disorder (PTSD) is prevalent in addiction treatment programs and a risk factor for negative outcomes. Although interventions have been developed to address substance use and PTSD, treatment options are needed that are effective, well tolerated by patients, and potentially integrated with existing program services. This paper describes a cognitive behavioral therapy (CBT) for PTSD that was adapted from a treatment for persons with severe mental illnesses and P...

  14. Entrapment of motor nerves in motor neuron disease: does double crush occur?

    OpenAIRE

    Chaudhry, V; Clawson, L L

    1997-01-01

    OBJECTIVE: To investigate whether "diseased nerves" are more prone to entrapment neuropathy than normal nerves. Nerve conduction studies of human neuropathies have shown that electrophysiological abnormalities are often most prominent at potential sites of nerve entrapment, and entrapments are more common in patients with radiculopathies--a concept designated as "double crush". As entrapment neuropathies commonly occur in otherwise healthy subjects, it is unclear whether this relation is coin...

  15. Clarifying Exercise Addiction: Differential Diagnosis, Co-occurring Disorders, and Phases of Addiction

    OpenAIRE

    Marilyn Freimuth; Kim, Shari R.; Sandy Moniz

    2011-01-01

    This paper sets out to clarify the unique features of exercise addiction. It begins by examining how this addiction can be distinguished from compulsions and impulse control disorders both of which, like an addiction, involve excessive behavior that creates adverse effects. Assessment of exercise addiction also requires that clinicians be attuned to other forms of excessive behavior, especially eating disorders that can co-occur with exercise. Finally in an effort to clarify exercise addictio...

  16. Distribution of zero sequence currents for earth faults occurring along a transmission line and proximity effects

    Energy Technology Data Exchange (ETDEWEB)

    Nahman, J. (Belgrade Univ. (Yugoslavia). Elektrotehnicki Fakultet); Dordevic, V. (Energoprojekt, Belgrade (Yugoslavia))

    1993-09-01

    A relatively simple procedure is suggested for the evaluation of the distribution of zero sequence currents, within the earthing system of a substation, for earth faults occurred along a line coming from the substation. The earthing system model derived takes into account all relevant phenomena including the mutual influence among earth electrodes through the soil to cover the proximity effects which were shown to be significant in certain cases. The procedure suggested is applied to a practical case, for illustration. (author)

  17. Pathological changes and local defense reaction occurring in spontaneous hepatic coccidiosis in rabbits (Oryctolagus cuniculus).

    OpenAIRE

    Darzi, M.M.; Mir, M S; Kamil, S.A.; Nashiruddullah, N.; Munshi, Z.H.

    2007-01-01

    Hepatic coccidiosis occurred in 56 rabbits belonging to different ages, sexes and breeds during the years from 2002 to 2005. Clinically, the severely affected rabbits showed decreased growth rate, anorexia, debilitation, listlessness, diarrhea, icterus and rough hair coat. Postmortem examinations revealed increased dirty dull straw colored peritoneal fluid. Hepatomegaly, with presence of discrete yellowish-white nodules of 1mm to 1 cm size on the surface and throughout the parenchyma, was see...

  18. Looking for spectral changes occurring during storage of ultra-cold neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Steyerl, A.; Malik, S.S. [Rhode Island Univ., Kingston, RI (United States); Geltenbort, P. [Institut Max von Laue - Paul Langevin (ILL), 38 -Grenoble (France)

    1997-04-01

    It seems that the spectrum of ultra-cold neutrons does change. The measured data indicate with 5{sigma} reliability, that a small heating by about 2{center_dot}10{sup -10} eV ({approx} 2 mm of rise height against the earth`s gravity) occurred during the initial {approx} 10{sup 3} wall reflections, and no change thereafter. The reason of this effect is searched for. (author). 3 refs.

  19. Natural occurring 2-(2-phenylethyl) chromones, structure elucidation and biological activities.

    Science.gov (United States)

    Ibrahim, Sabrin R M; Mohamed, Gamal A

    2015-01-01

    2-(2-Phenylethyl) chromone (PEC), an uncommon class of chromones, possesses a phenylethyl substituent at the C2 position. They have been isolated from a few plant species. They have promising biological activities such as neuro-protective, cytotoxic, acetylcholinesterase inhibitory, antibacterial and anti-inflammatory. This review focuses on the naturally occurring PEC derivatives, their sources, physical and spectral data, as well as biological activities.

  20. CJDATS CO-OCCURRING DISORDERS SCREENING INSTRUMENT (CODSI) FOR MENTAL DISORDERS (MD): A Validation Study

    OpenAIRE

    SACKS, STANLEY; Melnick, Gerald; Coen, Carrie; Banks, Steve; Friedmann, Peter D.; Grella, Christine; Knight, Kevin; Zlotnick, Caron

    2007-01-01

    Three standardized screening instruments—the Global Appraisal of Individual Needs Short Screener (GSS), the Mini-International Neuropsychiatric Interview–Modified (MINI-M), and the Mental Health Screening Form (MHSF)—were compared to two shorter instruments, the 6-item Co-Occurring Disorders Screening Instrument for Mental Disorders (CODSI-MD) and the 3-item CODSI for Severe Mental Disorders (CODSI-SMD) for use with offenders in prison substance-abuse treatment programs. Results showed that t...

  1. Occurence of a round window membrane rupture in patients with sudden sensorineural hearing loss

    OpenAIRE

    Haubner Frank; Rohrmeier Christian; Koch Christoph; Vielsmeier Veronika; Strutz Jürgen; Kleinjung Tobias

    2012-01-01

    Abstract Background Aim of the present study was to evaluate the occurence of a round window membrane rupture and the effects of hearing restoration after exploratory tympanotomy and sealing of the round window (niche) in patients with unilateral sudden deafness. Methods Retrospective analysis of patients’ charts in a tertiary referral center. Charts of 69 patients with sudden deafness followed by exploratory tympanotomy were retrospectively analyzed. Pure-tone audiometry data before and afte...

  2. Inhibition of the Corrosion of Mild Steel in Acid Media by Naturally Occurring Acacia Senegal

    Directory of Open Access Journals (Sweden)

    Urvija Garg

    2010-01-01

    Full Text Available The inhibition of corrosion of mild steel in HCl solution by naturally occurring Acacia Senegal has been studied in relation to the concentration of inhibitor and concentration of corrosive medium. It has been observed that the Acacia Senegal alcoholic extract acts as a good corrosion inhibitor in hydrochloric acid solution and the adsorption of the extract provides a good protection against mild steel corrosion.

  3. Automatic NMR-based identification of chemical reaction types in mixtures of co-occurring reactions.

    Science.gov (United States)

    Latino, Diogo A R S; Aires-de-Sousa, João

    2014-01-01

    The combination of chemoinformatics approaches with NMR techniques and the increasing availability of data allow the resolution of problems far beyond the original application of NMR in structure elucidation/verification. The diversity of applications can range from process monitoring, metabolic profiling, authentication of products, to quality control. An application related to the automatic analysis of complex mixtures concerns mixtures of chemical reactions. We encoded mixtures of chemical reactions with the difference between the (1)H NMR spectra of the products and the reactants. All the signals arising from all the reactants of the co-occurring reactions were taken together (a simulated spectrum of the mixture of reactants) and the same was done for products. The difference spectrum is taken as the representation of the mixture of chemical reactions. A data set of 181 chemical reactions was used, each reaction manually assigned to one of 6 types. From this dataset, we simulated mixtures where two reactions of different types would occur simultaneously. Automatic learning methods were trained to classify the reactions occurring in a mixture from the (1)H NMR-based descriptor of the mixture. Unsupervised learning methods (self-organizing maps) produced a reasonable clustering of the mixtures by reaction type, and allowed the correct classification of 80% and 63% of the mixtures in two independent test sets of different similarity to the training set. With random forests (RF), the percentage of correct classifications was increased to 99% and 80% for the same test sets. The RF probability associated to the predictions yielded a robust indication of their reliability. This study demonstrates the possibility of applying machine learning methods to automatically identify types of co-occurring chemical reactions from NMR data. Using no explicit structural information about the reactions participants, reaction elucidation is performed without structure elucidation of

  4. A Model for Sequential First Order Phage Transitions Occurring in the Underpotential Deposition of Metals,

    Science.gov (United States)

    1991-04-29

    22217-5000 1 1 1 11. TITLE (incde Securiy Clasicaton) A MODEL FOR SEQUENTIAL FIRST ORDER PHAGE TRANSITIONS OCCURRING IN THE UNDERPOTENTIAL DEPOSITION ...block number) FIELD GROUP SUB-GROUP 3 RACT (Continue on reverse if necessary and identify by block number) A model for the underpotential deposition of...this application we study the underpotential deposition of Cu on a Au(III) surface in the presence of sulfate ions. The voltammogram of the

  5. The Structure of Co-Occurring Bullying Experiences and Associations with Suicidal Behaviors in Korean Adolescents

    OpenAIRE

    Beop-Rae Roh; Yoewon Yoon; Ahye Kwon; Seunga Oh; Soyoung Irene Lee; Kyunghee Ha; Yun Mi Shin; Jungeun Song; Eun Jin Park; Heejung Yoo; Hyun Ju Hong

    2015-01-01

    Objective This study had two main goals: to examine the structure of co-occurring peer bullying experiences among adolescents in South Korea from the perspective of victims and to determine the effects of bullying on suicidal behavior, including suicidal ideation and suicide attempts, among adolescents. Method This study used data gathered from 4,410 treatment-seeking adolescents at their initial visits to 31 local mental health centers in Gyeonggi Province, South Korea. The structure of peer...

  6. A database of naturally occurring human urinary peptides and proteins for use in clinical applications

    OpenAIRE

    Petra Zürbig; Joshua Coon; Hartwig Bauer; Georg Behrens; Mohammed Dakna; Anna Dominiczak; Stephane Decramer; Jochen Ehrich; Danilo Fliser; Moritz Frommberger; Arnold Ganser; Mark Giolami; Igor Golovko; David Good; Wilfried Gwinner

    2007-01-01

    Owing to its availability, ease of collection and correlation with (patho-) physiology, urine is an attractive source for clinical proteomics. However, the lack of comparable datasets from large cohorts has greatly hindered development in this field. Here we report the establishment of a high resolution proteome database of naturally occurring human urinary peptides and proteins - ranging from 800-17,000 Da - from over 3,600 individual samples using capillary electrophoresis coupled to mass s...

  7. Effects of a naturally occurring compatible osmolyte on the internal dynamics of ribonuclease A.

    Science.gov (United States)

    Wang, A; Robertson, A D; Bolen, D W

    1995-11-21

    Osmolytes are small organic solutes accumulated intracellularly by many organisms as they adapt to environmental stresses. Compatible osmolytes, a functional class of osmolytes, increase protein stability while having little or no effect on protein function. To investigate the interrelationships between protein stability, function, and internal dynamics, a hydrogen exchange (HX) quench method was established and used to study the effects of sucrose (a typical compatible osmolyte) on the structural fluctuations of ribonuclease A. It was found that the HX rates of the amide protons with intermediate rates are not affected by 1 M sucrose, but the slow-exchanging amide protons exchange even slower in 1 M sucrose. The protection factors of the slow-exchanging protons fall into a comparatively narrow range while those of the intermediate-exchanging protons vary widely. In agreement with the two-process model [Woodward, C.K., & Hilton, B. D. (1980) Biophys. J. 32, 561-575], we conclude that for those slow-exchanging amide protons, the exchange occurs mainly from the compact unfolded state ensemble of the protein. The internal dynamics leading to slow exchange involve exposure of large protein surface areas, similar to that which occurs upon the unfolding of protein. Because sucrose opposes such an increase in protein surface area exposure, both the slow HX rates and the protein stability are affected by sucrose. For those amide protons with fast and intermediate HX rates, the exchange occurs mainly from the native state ensemble of the protein. The internal dynamics involved in the exchange are localized without much surface area change, and functionally important structural fluctuations are likely to occur within this dynamic range.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Microglial activation in the hippocampus of hypercholesterolemic rabbits occurs independent of increased amyloid production

    Directory of Open Access Journals (Sweden)

    Streit Wolfgang J

    2007-08-01

    Full Text Available Abstract Background Rabbits maintained on high-cholesterol diets are known to show increased immunoreactivity for amyloid beta protein in cortex and hippocampus, an effect that is amplified by presence of copper in the drinking water. Hypercholesterolemic rabbits also develop sporadic neuroinflammatory changes. The purpose of this study was to survey microglial activation in rabbits fed cholesterol in the presence or absence of copper or other metal ions, such as zinc and aluminum. Methods Vibratome sections of the rabbit hippocampus and overlying cerebral cortex were examined for microglial activation using histochemistry with isolectin B4 from Griffonia simplicifolia. Animals were scored as showing either focal or diffuse microglial activation with or without presence of rod cells. Results Approximately one quarter of all rabbits fed high-cholesterol diets showed evidence of microglial activation, which was always present in the hippocampus and not in the cortex. Microglial activation was not correlated spatially with increased amyloid immunoreactivity or with neurodegenerative changes and was most pronounced in hypercholesterolemic animals whose drinking water had been supplemented with either copper or zinc. Controls maintained on normal chow were largely devoid of neuroinflammatory changes, but revealed minimal microglial activation in one case. Conclusion Because the increase in intraneuronal amyloid immunoreactivity that results from administration of cholesterol occurs in both cerebral cortex and hippocampus, we deduce that the microglial activation reported here, which is limited to the hippocampus, occurs independent of amyloid accumulation. Furthermore, since neuroinflammation occurred in the absence of detectable neurodegenerative changes, and was also not accompanied by increased astrogliosis, we conclude that microglial activation occurs because of metabolic or biochemical derangements that are influenced by dietary factors.

  9. Modeling four occurred debris flow events in the Dolomites area (North-Eastern Italian Alps)

    Science.gov (United States)

    Boreggio, Mauro; Gregoretti, Carlo; Degetto, Massimo; Bernard, Martino

    2016-04-01

    Four occurred debris flows in the Dolomites area (North-Eastern Italian Alps) are modeled by back-analysis. The four debris flows events are those occurred at Rio Lazer (Trento) on the 4th of November 1966, at Fiames (Belluno) on the 5th of July 2006, at Rovina di Cancia (Belluno) on the 18th of July 2009 and at Rio Val Molinara (Trento) on the 15th of August 2010. In all the events, runoff entrained sediments present on natural channels and formed a solid-liquid wave that routed downstream. The first event concerns the routing of debris flow on an inhabited fan. The second event the deviation of debris flow from the usual path due to an obstruction with the excavation of a channel in the scree and the downstream spreading in a wood. The third event concerns the routing of debris flow in a channel with an ending the reservoir, its overtopping and final spreading in the inhabited area. The fourth event concerns the routing of debris flow along the main channel downstream the initiation area until spreading just upstream a village. All the four occurred debris flows are simulated by modeling runoff that entrained debris flow for determining the solid-liquid hydrograph. The routing of the solid-liquid hydrograph is simulated by a bi-phase cell model based on the kinematic approach. The comparison between simulated and measured erosion and deposition depths is satisfactory. Nearly the same parameters for computing erosion and deposition were used for all the four occurred events. The maps of erosion and deposition depths are obtained by comparing the results of post-event surveys with the pre-event DEM. The post-event surveys were conducted by using different instruments (LiDAR and GPS) or the combination photos-single points depth measurements (in this last case it is possible obtaining the deposition/erosion depths by means of stereoscopy techniques).

  10. Related factors of co-occurring mood disorders among heroin-dependent patients

    Institute of Scientific and Technical Information of China (English)

    杨梅

    2014-01-01

    Objective To explore related factors of co-occurring mood disorders among heroin-dependent patients.Methods A cross-sectional study was conducted.Subjects were 1002 heroin-dependent patients who were consecutively admitted into three drug rehabilitation institutes in Hunan Province.A questionnaire was developed to get demographic and drug use-related information of the subjects.The Structured Clinical Interview for

  11. Cerebral Post-Transplant Lymphoproliferative Disorder Occurring after Renal Transplantation: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Jang Ho; Byun, Woo Mok; Kim, Hong Chul; Hwang, Min Su [Dept. of Radiology, Yeungnam University College of Medicine, Daegu (Korea, Republic of)

    2012-04-15

    Post-transplant lymphoproliferative disorder (PTLD) is a complication of organ transplantation and immunosuppression. A 36-year-old woman with a history of renal transplantation visited the hospital complaining of headache and on pathology was diagnosed with cerebral PTLD manifesting as multiple rim enhanced masses in both hemispheres. We report here a case of post-transplant lymphoproliferative disorder involving the cerebrum occurring after renal transplantation, and describe the MRI findings for this patient

  12. Modified Therapeutic Community for Co-Occurring Disorders: A Summary of Four Studies

    OpenAIRE

    Sacks, Stanley; Banks, Steven; MCKENDRICK, KAREN; Sacks, JoAnn Y.

    2007-01-01

    This paper summarizes results from four research studies (N=902) that examined the effectiveness of the modified therapeutic community (MTC) for clients with co-occurring disorders (most with severe mental disorders). Significantly better outcomes for MTC were found across four E vs. C comparisons on 23.1% (12 of 52) of primary outcome measures of substance use, mental health, crime, HIV risk, employment and housing. Study limitations included the potential for selection bias, limited measure...

  13. The Structure of Co-Occurring Bullying Experiences and Associations with Suicidal Behaviors in Korean Adolescents

    OpenAIRE

    Beop-Rae Roh; Yoewon Yoon; Ahye Kwon; Seunga Oh; Soyoung Irene Lee; Kyunghee Ha; Yun Mi Shin; Jungeun Song; Eun Jin Park; Heejung Yoo; Hyun Ju Hong

    2015-01-01

    Objective This study had two main goals: to examine the structure of co-occurring peer bullying experiences among adolescents in South Korea from the perspective of victims and to determine the effects of bullying on suicidal behavior, including suicidal ideation and suicide attempts, among adolescents. Method This study used data gathered from 4,410 treatment-seeking adolescents at their initial visits to 31 local mental health centers in Gyeonggi Province, South Korea. The structure of peer...

  14. Microbiological contamination and resistance genes in biofilms occurring during the drinking water treatment process.

    Science.gov (United States)

    Farkas, Anca; Butiuc-Keul, Anca; Ciatarâş, Dorin; Neamţu, Călin; Crăciunaş, Cornelia; Podar, Dorina; Drăgan-Bularda, Mihail

    2013-01-15

    Biofilms are the predominant mode of microbial growth in drinking water systems. A dynamic exchange of individuals occurs between the attached and planktonic populations, while lateral gene transfer mediates genetic exchange in these bacterial communities. Integrons are important vectors for the spread of antimicrobial resistance. The presence of class 1 integrons (intI1, qac and sul genes) was assessed in biofilms occurring throughout the drinking water treatment process. Isolates from general and specific culture media, covering a wide range of environmental bacteria, fecal indicators and opportunistic pathogens were tested. From 96 isolates tested, 9.37% were found to possess genetic determinants of putative antimicrobial resistance, and these occurred in both Gram-positive and Gram-negative bacteria. Class 1 integron integrase gene was present in 8.33% of bacteria, all positive for the qacEΔ1 gene. The sul1 gene was present in 3.12% of total isolates, representing 37.5% of the class 1 integron positive cells. The present study shows that biofilm communities in a drinking water treatment plant are a reservoir of class 1 integrons, mainly in bacteria that may be associated with microbiological contamination. Eight out of nine integron bearing strains (88.8%) were identified based on 16S rRNA gene sequencing as either enteric bacteria or species that may be connected to animal and anthropogenic disturbance. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Topical voriconazole therapy of Purpureocillium lilacinum keratitis that occurred in disposable soft contact lens wearers.

    Science.gov (United States)

    Todokoro, Daisuke; Yamada, Norihiro; Fukuchi, Mariko; Kishi, Shoji

    2014-10-01

    The objective of this study was to describe 2 cases of keratitis caused by Purpureocillium lilacinum (formerly Paecilomyces lilacinus) that occurred in disposable contact lens users, which were successfully treated with topical voriconazole. Case 1 was a healthy 44-year-old woman, who wore weekly disposable contact lenses and had developed a superficial corneal infection in her right eye. For diagnosis, corneal scraping and molecular identification of the cultured pathogen were performed. A corneal smear revealed the presence of fungi. The pathogen was identified as P. lilacinum by traditional morphological identification of fungal culture, and this identification was confirmed by DNA sequencing of the ribosomal internal transcribed spacer (ITS) sequence. Therapy with topical fluconazole, topical pimaricin (natamycin), and oral itraconazole were ineffective. Topical voriconazole showed a significant effect, and the keratitis was successfully treated. Case 2 was a 43-year-old woman with bilateral recurrent peripheral corneal ulcers by meibomian gland dysfunction, who used therapeutic bandage contact lenses on her left eye. However, a corneal abscess with hypopyon occurred in the eye after 3 months. The microbial smear examination showed the presence of fungi and the fungal culture, and the DNA sequence of ITS region revealed that the causative agent was P. lilacinum. The susceptibility testing against antifungal agents showed that voriconazole was effective. The lesion improved gradually by topical voriconazole. As a conclusion, P. lilacinum keratitis can occur in disposable soft contact lens wearer. Early and accurate detection of the pathogenic organism is essential. Topical voriconazole was effective against P. lilacinum keratitis.

  16. Substance Use and Mental Health Stigma in Veterans With Co-Occurring Disorders.

    Science.gov (United States)

    Harnish, Autumn; Corrigan, Patrick; Byrne, Thomas; Pinals, Debra A; Rodrigues, Stephanie; Smelson, David

    2016-01-01

    This pilot study examined whether substance use or mental illness was more stigmatizing among individuals with co-occurring mental health and substance abuse problems. This study included 48 individuals with co-occurring substance use and mental health problems enrolled in a Substance Abuse and Mental Health Services funded treatment program. Subjects received a baseline assessment that included addiction, mental health, and stigma measures. The sample consisted primarily of White males with an average age of 38 years. Substance abuse was found to be more stigmatizing than mental illness, F(1, 47) = 14.213, p stigma varied across four different levels of stigma (Aware, Agree, Apply, and Harm), F(2.099, 98.675) = 117.883, p stigma was also significant, F(2.41, 113.284) = 20.250, p stigma between types varied across levels of stigma. Post hoc tests found a significant difference between all levels of stigma except for the comparison between Apply and Harm. Reported stigma was significantly higher for substance abuse than mental illness at the Aware and Agree levels. In addition, pairwise comparisons found significant differences between all levels of stigma with the exception of the comparison between Apply and Harm, indicating a pattern whereby reported stigma generally decreased from the first level (Aware stage) to subsequent levels. These results have important implications for treatment, suggesting the need to incorporate anti-stigma interventions for individuals with co-occurring disorders with a greater focus on substance abuse.

  17. Fluctuations in species-level protein expression occur during element and nutrient cycling in the subsurface.

    Directory of Open Access Journals (Sweden)

    Michael J Wilkins

    Full Text Available While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measurements. Following carbon amendment, 16S rRNA analysis of temporally separated samples revealed the rapid enrichment of Geobacter-like environmental strains with strong similarity to G. bemidjiensis. Tandem mass spectrometry proteomics measurements suggest high carbon flux through Geobacter respiratory pathways, and the synthesis of anapleurotic four carbon compounds from acetyl-CoA via pyruvate ferredoxin oxidoreductase activity. Across a 40-day period where Fe(III reduction was occurring, fluctuations in protein expression reflected changes in anabolic versus catabolic reactions, with increased levels of biosynthesis occurring soon after acetate arrival in the aquifer. In addition, localized shifts in nutrient limitation were inferred based on expression of nitrogenase enzymes and phosphate uptake proteins. These temporal data offer the first example of differing microbial protein expression associated with changing geochemical conditions in a subsurface environment.

  18. Phytohormonal basis for the plant growth promoting action of naturally occurring biostimulators.

    Science.gov (United States)

    Kurepin, Leonid V; Zaman, Mohammad; Pharis, Richard P

    2014-07-01

    There is increasing interest in the use of naturally occurring 'biostimulators' for enhancing the growth of agricultural and horticultural crops. Bacteria, fungi and protozoa, as well as marine algae-based seaweed extracts, can produce or contain biostimulators. The activity of biostimulators to promote plant growth is often attributed to their ability to directly or indirectly provide mineral nutrients (mostly N, but also P, S and other macro- and micro-nutrients) to plants. Alternatively, biostimulators are postulated to increase the plant's ability to assimilate these mineral nutrients, often in return for photo-assimilates (as occurs with certain bacteria and fungi associations). Although optimal growth of plants depends on the availability of adequate mineral nutritients, that growth (and also development, including reproduction) is also regulated by plant hormones (phytohormones), including gibberellins, auxins and cytokinins. This review describes and discusses the evidence that the presence or application of biostimulators also increases plant growth directly via phytohormone action and also influences the plant's ability to control its own hormone biosynthesis and homeostasis. Finally, it discusses the need for a better understanding of the role(s) that are played by the naturally occurring biostimulators associated with the plant in the crop field. It is suggested that better understanding will allow for optimal crop yield returns, since disruptions of phytohormone homeostasis in plant organs and tissues can yield either beneficial or sub-optimal outcomes.

  19. Nuclear fusion occurs during mating in Candida albicans and is dependent on the KAR3 gene.

    Science.gov (United States)

    Bennett, Richard J; Miller, Mathew G; Chua, Penelope R; Maxon, Mary E; Johnson, Alexander D

    2005-02-01

    It is now well established that mating can occur between diploid a and alpha cells of Candida albicans. There is, however, controversy over when, and with what efficiency, nuclear fusion follows cell fusion to create stable tetraploid a/alpha cells. In this study, we have analysed the mating process between C. albicans strains using both cytological and genetic approaches. Using strains derived from SC5314, we used a number of techniques, including time-lapse microscopy, to demonstrate that efficient nuclear fusion occurs in the zygote before formation of the first daughter cell. Consistent with these observations, zygotes micromanipulated from mating mixes gave rise to mononuclear tetraploid cells, even when no selection for successful mating was applied to them. Mating between different clinical isolates of C. albicans revealed that while all isolates could undergo nuclear fusion, the efficiency of nuclear fusion varied in different crosses. We also show that nuclear fusion in C. albicans requires the Kar3 microtubule motor protein. Deletion of the CaKAR3 gene from both mating partners had little or no effect on zygote formation but reduced the formation of stable tetraploids more than 600-fold, as determined by quantitative mating assays. These findings demonstrate that nuclear fusion is an active process that can occur in C. albicans at high frequency to produce stable, mononucleate mating products.

  20. Nuclear fusion during yeast mating occurs by a three-step pathway.

    Science.gov (United States)

    Melloy, Patricia; Shen, Shu; White, Erin; McIntosh, J Richard; Rose, Mark D

    2007-11-19

    In Saccharomyces cerevisiae, mating culminates in nuclear fusion to produce a diploid zygote. Two models for nuclear fusion have been proposed: a one-step model in which the outer and inner nuclear membranes and the spindle pole bodies (SPBs) fuse simultaneously and a three-step model in which the three events occur separately. To differentiate between these models, we used electron tomography and time-lapse light microscopy of early stage wild-type zygotes. We observe two distinct SPBs in approximately 80% of zygotes that contain fused nuclei, whereas we only see fused or partially fused SPBs in zygotes in which the site of nuclear envelope (NE) fusion is already dilated. This demonstrates that SPB fusion occurs after NE fusion. Time-lapse microscopy of zygotes containing fluorescent protein tags that localize to either the NE lumen or the nucleoplasm demonstrates that outer membrane fusion precedes inner membrane fusion. We conclude that nuclear fusion occurs by a three-step pathway.

  1. Mechanism study of sticking occurring during hot rolling of ferritic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Dae Jin; Sung, Hyo Kyung; Lee, Sung Hak [Pohang University of Science and Technoogy, Pohang (Korea, Republic of); Lee, Jong Seog; Lee, Yong Deuk [Pohang Iron and Steel Co., Pohang (Korea, Republic of)

    2008-11-15

    Mechanisms of sticking phenomena occurring during hot rolling of a modified STS 430J1L ferritic stainless steel have been investigated in this study by using a pilot-plant-scale rolling machine. As the rolling pass proceeds, the Fe-Cr oxide layer formed in a reheating furnace is destroyed, and the destroyed oxides penetrate into the rolled steel to form a thin oxide layer on the surface region. The sticking does not occur on the surface region containing oxides, whereas it occurs on the surface region without oxides by the separation of the rolled steel at high temperatures. This indicates that the resistance to sticking increases by the increase in the surface hardness when a considerable amount of oxides are formed on the surface region, and that the sticking can be evaluated by the volume fraction and distribution of oxides formed on the surface region. The lubrication and the increase of the rolling speed and rolling temperature beneficially affect to the resistance to sticking because they accelerate the formation of oxides on the steel surface region. In order to prevent or minimize the sticking, thus, it is suggested to increase the thickness of the oxide layer formed in the reheating furnace and to homogeneously distribute oxides along the surface region by controlling the hot-rolling process.

  2. Observations of magnetospheric substorms occurring with no apparent solar wind/IMF trigger

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, M.G.; Reeves, G.D.; Belian, R.D. [Los Alamos National Lab., NM (United States); Murphree, J.S. [Univ. of Calgary, Alberta (Canada)

    1996-03-01

    An outstanding topic in magnetospheric physics is whether substorms are always externally triggered by disturbances in either the interplanetary magnetic field or solar wind, or whether they can also occur solely as the result of an internal magnetospheric instability. Over the past decade, arguments have been made on both sides of this issue. Horwitz and McPherron have shown examples of substorm onsets which they claimed were not externally triggered. However, as pointed out by Lyons, there are several problems associated with these studies that make their results somewhat inconclusive. In particular, in the McPherron et al. study, fluctuations in the B{sub y} component were not considered as possible triggers. Furthermore, Lyons suggests that the sharp decreases in the AL index during intervals of steady IMF/solar wind, are not substorms at all but rather that they are just enhancements of the convection driven DP2 current system that are often observed to occur during steady magnetospheric convection events. In the present study, we utilize a much more comprehensive dataset (consisting of particle data from the Los Alamos energetic particle detectors at geosynchronous orbit, IMP 8 magnetometer and plasma data, Viking UV auroral imager data, mid-latitude Pi2 pulsation data, ground magnetometer data and ISEE1 magnetic field and energetic particle data) to show as unambiguously as possible that typical substorms can indeed occur in the absence of an identifiable trigger in the solar wind/IMF.

  3. Differentiation of naturally-occurring vs. artificial hydrocarbons in a landfill groundwater investigation

    Energy Technology Data Exchange (ETDEWEB)

    Beaver, J.L.; Hartness, J.A.; Breeding, L.B.; Buchanan, D.M. [Law Environmental, Inc., Kennesaw, GA (United States)

    1994-12-31

    Interpretation of groundwater sampling data at a large municipal/industrial landfill indicates contamination by both artificial and naturally-occurring hydrocarbons. Site hydrogeology consists of three different water bearing zones. The uppermost (shallow) aquifer is an unconfined unit consisting of silt, clay, and sand deposits. An intermediate depth semiconfined aquifer underlies the unconfined unit, and consists of a chert rubble zone and the upper portion of a fractured and solution-enhanced limestone formation. A regionally-extensive organic-rich shale underlies the semiconfined aquifer and separates it from the deep confined aquifer, which also consists of limestone. Groundwater investigations at the landfill have detected chlorinated and non-chlorinated hydrocarbons in the different aquifer intervals. Chlorinated hydrocarbons detected include tetrachloroethene, dichloroethene, and vinyl chloride and occur almost exclusively in the shallow aquifer. Aromatic hydrocarbons detected include benzene, toluene, ethylbenzene, and xylene (BTEX) and-occur in the intermediate and deep aquifers. The landfill was originally interpreted as the source of the contaminants. The observation of free-phase liquid hydrocarbons in the intermediate aquifer at the site, and high dissolved BTEX levels in the deep and intermediate aquifers upgradient of the landfill suggest that the aromatics were derived from a source other than the landfill. A potential source of BTEX contamination may be abandoned (pre-1930) natural gas wells located near the landfill. An additional BTEX source may be the organic-rich shale formation (a documented petroleum source rock).

  4. Beneficial Plant Microbe Interaction in Adverse Climatic Condition

    OpenAIRE

    Mohammad Oves

    2015-01-01

    There are two well-known old American and Japanese quotes "snug as a bug in a rug” and ‘Tade kuu mushi mo suki-zuki’ which means very comfortable and everyone has their own tastes respectively, both quotes are best fit for beneficial plantmicrobes (PM) interactions. Most of the plants interact largely with diverse microorganisms in their surrounding environment but the question arises why PM interaction exist everywhere in agroecosystem with sustainability? PM interactions were occurred from ...

  5. The geochemistry of naturally occurring methane and saline groundwater in an area of unconventional shale gas development

    Science.gov (United States)

    Harkness, Jennifer S.; Darrah, Thomas H.; Warner, Nathaniel R.; Whyte, Colin J.; Moore, Myles T.; Millot, Romain; Kloppmann, Wolfram; Jackson, Robert B.; Vengosh, Avner

    2017-07-01

    Since naturally occurring methane and saline groundwater are nearly ubiquitous in many sedimentary basins, delineating the effects of anthropogenic contamination sources is a major challenge for evaluating the impact of unconventional shale gas development on water quality. This study investigates the geochemical variations of groundwater and surface water before, during, and after hydraulic fracturing and in relation to various geospatial parameters in an area of shale gas development in northwestern West Virginia, United States. To our knowledge, we are the first to report a broadly integrated study of various geochemical techniques designed to distinguish natural from anthropogenic sources of natural gas and salt contaminants both before and after drilling. These measurements include inorganic geochemistry (major cations and anions), stable isotopes of select inorganic constituents including strontium (87Sr/86Sr), boron (δ11B), lithium (δ7Li), and carbon (δ13C-DIC), select hydrocarbon molecular (methane, ethane, propane, butane, and pentane) and isotopic tracers (δ13C-CH4, δ13C-C2H6), tritium (3H), and noble gas elemental and isotopic composition (helium, neon, argon) in 105 drinking-water wells, with repeat testing in 33 of the wells (total samples = 145). In a subset of wells (n = 20), we investigated the variations in water quality before and after the installation of nearby ( 50 mg/L). The integrated geochemical data indicate that the saline groundwater originated via naturally occurring processes, presumably from the migration of deeper methane-rich brines that have interacted extensively with coal lithologies. These observations were consistent with the lack of changes in water quality observed in drinking-water wells following the installation of nearby shale-gas wells. In contrast to groundwater samples that showed no evidence of anthropogenic contamination, the chemistry and isotope ratios of surface waters (n = 8) near known spills or leaks

  6. RAT EXOCRINE PANCREATIC SECRETION BY VAGAL STIMULATION OCCURS VIA MULTIPLE MEDIATORS

    Institute of Scientific and Technical Information of China (English)

    何晓东; MTimmthyNelson; HaileTDebas

    1996-01-01

    The vagus is a mixed nerve containing cholinerrgic and non-cholinergie neurons. Vagal fibers interact with peptidergic neurons of the enteric nervous system which stain immunohistcchemically for cholecystokinin, vasoactive intestinal polypeptide, and gastrin releasing peptide. The contribution of these pepticdergic neurons in the pancreatic response to vagal stimulation is unknown. We tested the effect of specific inhibitor of these stimulants against vagally mediated exocrine secretion in rats. The response to vagal stimulation was blocked significantly hy each of the following:the ganglionic blocker hexmethoninm (100% inhibition); the muscarinic, cholinergic blocker atropine (85%inhibition) ; the specific cholaeystokinln-A receptor blocker (91% inhibition); and a vasoactive intestinal polypeptide polyclonal antibody (89% inhibition). This observation is consistent with the hypothesis that potentiating interactions among several agonisrs mediate the vagal response. Our study, however, dose not exclude acetylehollne as the final commom mediator.

  7. [The co-occurence of Cryptosporidium parvum, Giardia spp. and helminth infections in small rodent populations].

    Science.gov (United States)

    Bajer, Anna; Behnke, Jerzy M; Bednarska, Małgorzata; Kuliś, Karolina; Siński, Edward

    2004-01-01

    During long-term (1998-2000) studies on rodent parasite populations in Mazury lake district there were collected and analyzed data on co-occurrence of intestinal protozoa (Cryptosporidium parvum, Giardia spp.) and helminths. There were performed 178 autopsies of common vole Microtus arvalis, 85 autopsies of yellow-necked mouse Apodemus flavicollis and 386 autopsies of bank vole Clethrionomys glareolus. Positive effect of helminth infections was found in C. glareolus. Voles infected with nematode Heligmosomum mixtum showed higher prevalence of C. parvum and Giardia spp. than voles infected with Heligmosomoides glareoli. The host age took part in these interactions and positive effect of co-occurrence was mainly observed in voles older than 3 months. The other intrinsic (host sex) or extrinsic (season and year of study) factors influenced interactions between parasites. Presented results revealed that helminth infections may facilitate chronic infections of intestinal protozoa in rodent populations.

  8. Encapsulation of piceatannol, a naturally occurring hydroxylated analogue of resveratrol, by natural and modified cyclodextrins.

    Science.gov (United States)

    Matencio, Adrián; García-Carmona, Francisco; López-Nicolás, José Manuel

    2016-05-18

    In this work, an in-depth study of the interaction between piceatannol (a type of stilbene with high biological activity) and different natural and modified cyclodextrins (CDs) is made, using steady state fluorescence. This bioactive molecule forms a 1 : 1 complex with all the natural (α-CD, β-CD and γ-CD) and modified (HP-β-CD, HE-β-CD and M-β-CD) CDs tested. Among natural CDs, the interaction of piceatannol with β-CD was the most efficient. However, the modified CDs showed higher encapsulation constants (KF) than β-CD, except M-β-CD; the highest KF being found for HP-β-CD (14 048 ± 702 M(-1)). The encapsulation of piceatannol in the internal cavity of CDs showed a strong dependence on pH and temperature. The interaction between HP-β-CD and piceatannol was less effective in the pH region where the stilbene begins to suffer the deprotonation of its hydroxyl group. Moreover, the values of KF decreased as the system temperature increased. To obtain information on the mechanism involved in the piceatannol affinity for CD, the thermodynamic parameters of the complexation (ΔH°, ΔS° and ΔG°) were studied, the results showed a negative entropy (-3.7 ± 0.2 J mol(-1) K(-1)), enthalpy (-24.6 ± 1.2 kJ mol(-1)) and Gibbs free energy change at 25 °C (-23.5 ± 1.2 J mol(-1)). Finally, molecular docking calculations provided further insights into how the different interactions influence the complexation constant. A high degree of correlation was observed between the computed scores and experimental values.

  9. A Naturally Occurring Isoform Inhibits Parathyroid Hormone Receptor Trafficking and Signaling

    OpenAIRE

    Alonso, Ver?nica; Ardura, Juan A; WANG Bin; Sneddon, W Bruce; Peter A Friedman

    2010-01-01

    Parathyroid hormone (PTH) regulates calcium homeostasis and bone remodeling through its cognitive receptor (PTHR). We describe here a PTHR isoform harboring an in-frame 42-bp deletion of exon 14 (?e14-PTHR) that encodes transmembrane domain 7. ?e14-PTHR was detected in human kidney and buccal epithelial cells. We characterized its topology, cellular localization, and signaling, as well as its interactions with PTHR. The C-terminus of the ?e14-PTHR is extracellular, and cell surface expression...

  10. Does chemical aposematic (warning) signaling occur between host plants and their potential parasitic plants?

    OpenAIRE

    Lev-Yadun, Simcha

    2013-01-01

    Aposematism (warning) signaling is a common defensive mechanism toward predatory or herbivorous animals, i.e., interactions between different trophic levels. I propose that it should be considered at least as a working hypothesis that chemical aposematism operates between certain host plants and their plant predators, parasitic plants, and that although they are also plants, they belong to a higher trophic level. Specific host plant genotypes emit known repelling chemical signals toward paras...

  11. Nonverbal synchrony and affect in dyadic interactions.

    Science.gov (United States)

    Tschacher, Wolfgang; Rees, Georg M; Ramseyer, Fabian

    2014-01-01

    In an experiment on dyadic social interaction, we invited participants to verbal interactions in cooperative, competitive, and 'fun task' conditions. We focused on the link between interactants' affectivity and their nonverbal synchrony, and explored which further variables contributed to affectivity: interactants' personality traits, sex, and the prescribed interaction tasks. Nonverbal synchrony was quantified by the coordination of interactants' body movement, using an automated video-analysis algorithm (motion energy analysis). Traits were assessed with standard questionnaires of personality, attachment, interactional style, psychopathology, and interpersonal reactivity. We included 168 previously unacquainted individuals who were randomly allocated to same-sex dyads (84 females, 84 males, mean age 27.8 years). Dyads discussed four topics of general interest drawn from an urn of eight topics, and finally engaged in a fun interaction. Each interaction lasted 5 min. In between interactions, participants repeatedly assessed their affect. Using hierarchical linear modeling, we found moderate to strong effect sizes for synchrony to occur, especially in competitive and fun task conditions. Positive affect was associated positively with synchrony, negative affect was associated negatively. As for causal direction, data supported the interpretation that synchrony entailed affect rather than vice versa. The link between nonverbal synchrony and affect was strongest in female dyads. The findings extend previous reports of synchrony and mimicry associated with emotion in relationships and suggest a possible mechanism of the synchrony-affect correlation.

  12. Nonverbal synchrony and affect in dyadic interactions

    Directory of Open Access Journals (Sweden)

    Wolfgang eTschacher

    2014-11-01

    Full Text Available In an experiment on dyadic social interaction, we invited participants to verbal interactions in cooperative, competitive, and 'fun task' conditions. We focused on the link between interactants' affectivity and their nonverbal synchrony, and explored which further variables contributed to affectivity: interactants' personality traits, sex, and the prescribed interaction tasks. Nonverbal synchrony was quantified by the coordination of interactants' body movement, using an automated video-analysis algorithm (Motion Energy Analysis, MEA. Traits were assessed with standard questionnaires of personality, attachment, interactional style, psychopathology and interpersonal reactivity. We included 168 previously unacquainted individuals who were randomly allocated to same-sex dyads (84 females, 84 males, mean age 27.3 years. Dyads discussed four topics of general interest drawn from an urn of eight topics, and finally engaged in a fun interaction. Each interaction lasted five minutes. In between interactions, participants repeatedly assessed their affect. Using hierarchical linear modeling, we found moderate to strong effect sizes for synchrony to occur, especially in competitive and fun task conditions. Positive affect was associated positively with synchrony, negative affect was associated negatively. As for causal direction, data supported the interpretation that synchrony entailed affect rather than vice versa. The link between nonverbal synchrony and affect was strongest in female dyads. The findings extend previous reports of synchrony and mimicry associated with emotion in relationships and suggest a possible mechanism of the synchrony-affect correlation.

  13. Interactivity vs. fairness in networked linux systems

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenji; Crawford, Matt; /Fermilab

    2007-01-01

    In general, the Linux 2.6 scheduler can ensure fairness and provide excellent interactive performance at the same time. However, our experiments and mathematical analysis have shown that the current Linux interactivity mechanism tends to incorrectly categorize non-interactive network applications as interactive, which can lead to serious fairness or starvation issues. In the extreme, a single process can unjustifiably obtain up to 95% of the CPU! The root cause is due to the facts that: (1) network packets arrive at the receiver independently and discretely, and the 'relatively fast' non-interactive network process might frequently sleep to wait for packet arrival. Though each sleep lasts for a very short period of time, the wait-for-packet sleeps occur so frequently that they lead to interactive status for the process. (2) The current Linux interactivity mechanism provides the possibility that a non-interactive network process could receive a high CPU share, and at the same time be incorrectly categorized as 'interactive.' In this paper, we propose and test a possible solution to address the interactivity vs. fairness problems. Experiment results have proved the effectiveness of the proposed solution.

  14. Differential CCR7 targeting in dendritic cells by three naturally occurring CC-chemokines

    Directory of Open Access Journals (Sweden)

    Gertrud Malene Hjortø

    2016-12-01

    Full Text Available The CCR7 ligands CCL19 and CCL21 are increasingly recognized as functionally different (biased. Using mature human dendritic cells (DCs, we show that CCL19 is more potent than CCL21 in inducing 3D chemotaxis. Intriguingly, CCL21 induces prolonged and more efficient ERK1/2 activation compared to CCL19 and to a C-terminal truncated (tailless CCL21 in DCs. In contrast, tailless-CCL21 displays increased potency in DC chemotaxis compared to native CCL21. Using a CCL21-specific antibody, we show that CCL21, but not tailless-CCL21, accumulates at the cell surface. In addition removal of sialic acid from the cell surface by neuraminidase treatment impairs ERK1/2 activation by CCL21, but not of CCL19 or tailless-CCL21. Using standard laboratory cell-lines, we observe low potency of both CCL21 and tailless-CCL21 in G protein activation and -arrestin recruitment compared to CCL19, indicating that the tail itself does not improve receptor interaction. Chemokines interact with their receptors in a stepwise manner with ultimate docking of their N-terminus into the main binding pocket. Employing site-directed mutagenesis we identify residues in this pocket of selective CCL21 importance. We also identify a molecular switch in the top of TM7 important for keeping CCR7 in an inactive conformation (Tyr312, as introduction of the chemokine receptor-conserved Glu (or Ala induces high constitutive activity. Summarized, we show that the interaction of the tail of CCL21 with polysialic acid is needed for strong ERK-signaling, whereas it impairs CCL21-mediated chemotaxis and has no impact on receptor docking consistent with the current model of chemokine:receptor interaction. This indicates that future selective pharmacological targeting of CCL19 versus CCL21 should focus on a differential targeting of the main receptor pocket, while selective targeting of tailless-CCL21 versus CCL21 and CCL19 requires targeting of the glycosaminoglycan (GAG interaction.

  15. Phosphorylated peptides occur in a non-helical portion of the tail of a catch muscle myosin

    Energy Technology Data Exchange (ETDEWEB)

    Castellani, L.; Elliott, B.W. Jr.; Cohen, C.

    1987-05-01

    Myosin from a molluscan catch muscle (the Anterior Byssus Retractor (ABRM) of Mytilus edulis) is unusual in being phosphorylated in the rod by an endogenous heavy-chain kinase. This phosphorylation enhances myosin solubility at low ionic strength and induces molecular folding of the myosin tail. Papain and chymotryptic cleavage of this myosin, phosphorylated with (..gamma..-/sup 32/P)ATP, indicates that the phosphorylated residues are associated with the carboxy-terminal end of the light meromyosin. Ion-exchange and reverse-phase HPLC of radiolabeled chymotryptic peptides allow the isolation of two different peptides with high specific activity. One of these peptides is rich in lysine and arginine residues, a finding consistent with the observation that basic residues often determine the substrate specificity of protein kinases. The second peptide contains proline residues. Taken together, these results suggest that, as in the case of Acanthamoeba myosin, phosphorylation occurs in a nonhelical portion of the rod that may also control solubility. Identification of the residues that are phosphorylated and their location in the rod may reveal how the phosphorylation-dependent changes observed in the myosin in vitro are related to changes in intermolecular interactions in the thick filaments in vivo.

  16. Teaching points-do they occur and what do they contain? An observation study concerning the general practice rotation.

    Science.gov (United States)

    Duncan, Gertrude Florence; Roth, Lisa Marie; Donner-Banzhoff, Nobert; Boesner, Stefan

    2016-04-18

    A general practice rotation is mandatory in most undergraduate medical education programs. However, little is known about the student-teacher interaction which takes place in this setting. In this study we analyzed occurrence and content of teaching points. From April to December 2012, 410 individual patient consultations were observed in twelve teaching practices associated with the Philipps University Marburg, Germany. Material was collected using structured field-note forms and videotaping. Data analysis was descriptive in form. A teaching point is defined here as a general rule or specific, case-related information divulged by the teaching practitioner. According to the analysis of 410 consultations, teaching points were made in 66.3% of consultations. During these consultations, 74.3% general- and 46.3% case related teaching points occurred; multiple categorizations were possible. Of seven possible topics, therapy was most common, followed, in frequency of occurrence, by patient history, diagnostic procedure, physical examination, disease pathology, differential diagnosis, risk factors and case presentation. The majority of consultations conducted within student presence contained teaching points, most frequently concerning therapy. General teaching points were more common than specific teaching points. Whilst it is encouraging that most consultations included teaching points, faculty development aimed at raising awareness for teaching and learning techniques is important.

  17. Chromatin modification by PSC occurs at one PSC per nucleosome and does not require the acidic patch of histone H2A.

    Science.gov (United States)

    Lo, Stanley M; McElroy, Kyle A; Francis, Nicole J

    2012-01-01

    Chromatin architecture is regulated through both enzymatic and non-enzymatic activities. For example, the Polycomb Group (PcG) proteins maintain developmental gene silencing using an array of chromatin-based mechanisms. The essential Drosophila PcG protein, Posterior Sex Combs (PSC), compacts chromatin and inhibits chromatin remodeling and transcription through a non-enzymatic mechanism involving nucleosome bridging. Nucleosome bridging is achieved through a combination of nucleosome binding and self-interaction. Precisely how PSC interacts with chromatin to bridge nucleosomes is not known and is the subject of this work. We determine the stoichiometry of PSC-chromatin interactions in compact chromatin (in which nucleosomes are bridged) using Scanning Transmission Electron Microscopy (STEM). We find that full compaction occurs with one PSC per nucleosome. In addition to compacting chromatin, we show that PSC oligomerizes nucleosome arrays. PSC-mediated oligomerization of chromatin occurs at similar stoichiometry as compaction suggesting it may also involve nucleosome bridging. Interactions between the tail of histone H4 and the acidic patch of histone H2A are important for chromatin folding and oligomerization, and several chromatin proteins bind the histone H2A acidic patch. However, mutation of the acidic patch of histone H2A does not affect PSC's ability to inhibit chromatin remodeling or bridge nucleosomes. In fact, PSC does not require nucleosomes for bridging activity but can bridge naked DNA segments. PSC clusters nucleosomes on sparsely assembled templates, suggesting it interacts preferentially with nucleosomes over bare DNA. This may be due to the ability of PSC to bind free histones. Our data are consistent with a model in which each PSC binds a nucleosome and at least one other PSC to directly bridge nucleosomes and compact chromatin, but also suggest that naked DNA can be included in compacted structures. We discuss how our data highlight the diversity

  18. Chromatin modification by PSC occurs at one PSC per nucleosome and does not require the acidic patch of histone H2A.

    Directory of Open Access Journals (Sweden)

    Stanley M Lo

    Full Text Available Chromatin architecture is regulated through both enzymatic and non-enzymatic activities. For example, the Polycomb Group (PcG proteins maintain developmental gene silencing using an array of chromatin-based mechanisms. The essential Drosophila PcG protein, Posterior Sex Combs (PSC, compacts chromatin and inhibits chromatin remodeling and transcription through a non-enzymatic mechanism involving nucleosome bridging. Nucleosome bridging is achieved through a combination of nucleosome binding and self-interaction. Precisely how PSC interacts with chromatin to bridge nucleosomes is not known and is the subject of this work. We determine the stoichiometry of PSC-chromatin interactions in compact chromatin (in which nucleosomes are bridged using Scanning Transmission Electron Microscopy (STEM. We find that full compaction occurs with one PSC per nucleosome. In addition to compacting chromatin, we show that PSC oligomerizes nucleosome arrays. PSC-mediated oligomerization of chromatin occurs at similar stoichiometry as compaction suggesting it may also involve nucleosome bridging. Interactions between the tail of histone H4 and the acidic patch of histone H2A are important for chromatin folding and oligomerization, and several chromatin proteins bind the histone H2A acidic patch. However, mutation of the acidic patch of histone H2A does not affect PSC's ability to inhibit chromatin remodeling or bridge nucleosomes. In fact, PSC does not require nucleosomes for bridging activity but can bridge naked DNA segments. PSC clusters nucleosomes on sparsely assembled templates, suggesting it interacts preferentially with nucleosomes over bare DNA. This may be due to the ability of PSC to bind free histones. Our data are consistent with a model in which each PSC binds a nucleosome and at least one other PSC to directly bridge nucleosomes and compact chromatin, but also suggest that naked DNA can be included in compacted structures. We discuss how our data

  19. Offshore Structural Control Considering Fluid Structure Interaction

    Institute of Scientific and Technical Information of China (English)

    Ju Myung KIM; Dong Hyawn KIM; Gyu Won LEE

    2006-01-01

    Tuned Mass Damper (TMD) was applied to an offshore structure to control ocean wave-induced vibration. In the analysis of the dynamic response of the offshore structure, fluid-structure interaction is considered and the errors, which occur in the linearization of the interaction, are investigated. For the investigation of the performance of TMD in controlling the vibration, both regular waves with different periods and irregular waves with different significant wave heights are used. Based on the numerical analysis it is concluded that the fluid-structure interaction should be considered in the evaluation of the capability of TMD in vibration control of offshore structures.

  20. Fundamental trends in fluid-structure interaction

    CERN Document Server

    Galdi, Giovanni P

    2010-01-01

    The interaction of a fluid with a solid body is a widespread phenomenon in nature, occurring at different scales and different applied disciplines. Interestingly enough, even though the mathematical theory of the motion of bodies in a liquid is one of the oldest and most classical problems in fluid mechanics, mathematicians have, only very recently, become interested in a systematic study of the basic problems related to fluid-structure interaction, from both analytical and numerical viewpoints. ""Fundamental Trends in Fluid-Structure Interaction"" is a unique collection of important papers wr

  1. Problem of interactions: electromagnetic particles interaction

    CERN Document Server

    Sannikov-Proskuryakov, S S

    2001-01-01

    The electromagnetic interactions between charged particles are derived on the basis of the particles dynamic theory, proposed in the work of Sannikov. The electromagnetic interactions exist only in the relativistic model of the bihamiltonian system, based on the Heisenberg algebra. Existence of this type of interactions is connected with the U sub e (1)-degeneration of the basic state of the relativistic bihamiltonian system, lying in the basis of the given theory

  2. Comparison of Thoracic Radiography and Computed Tomography in Calves with Naturally Occurring Respiratory Disease

    Directory of Open Access Journals (Sweden)

    Jennifer Fowler

    2017-07-01

    Full Text Available ObjectiveTo evaluate the severity and extent of lung disease using thoracic computed radiography (CR compared to contrast-enhanced multi-detector computed tomography (MDCT of the thorax in calves with naturally occurring respiratory disease and to evaluate the feasibility and safety of performing contrast-enhanced thoracic multi-detector MDCT examinations in sedated calves. Furthermore, to evaluate if combining CR or MDCT with respiratory scoring factors will improve prediction of the chronicity of pulmonary disease in calves.AnimalsThirty Jersey heifer calves ranging in age between 25 and 89 days with naturally occurring respiratory disease.ProceduresAll calves were evaluated via thoracic CR and contrast-enhanced MDCT. All calves were euthanized immediately following thoracic MDCT and submitted for necropsy. Imaging and histopathology results were compared with each other.ResultsThoracic MDCT was superior for evaluation of pneumonia in calves due to the lack of summation in all areas of the lungs. Intravenously administered sedation provided an adequate plane of sedation for acquiring MDCT images of diagnostic quality, without the need for re-scanning. A diagnosis of pneumonia was made with equal rate on both thoracic CR and MDCT. Although mild differences in classification of lung pattern and extent of lung disease were seen when comparing an experienced and a less experienced evaluator, the overall differences were not statistically significant. The best intra- and inter-observer agreement was noted when evaluating the cranioventral aspects of the lungs in either modality. Clinical respiratory scoring is inadequate for diagnosing chronicity of pneumonia in calves with naturally occurring pneumonia.Conclusion and clinical importanceBoth imaging modalities allowed diagnosis of pneumonia in calves. The cranial ventral aspects of the lungs were most commonly affected. Thoracic CR and MDCT provided similar diagnostic effectiveness in diagnosing

  3. Clinical Outcomes and Co-Occurring Mutations in Patients with RUNX1-Mutated Acute Myeloid Leukemia.

    Science.gov (United States)

    Khan, Maliha; Cortes, Jorge; Kadia, Tapan; Naqvi, Kiran; Brandt, Mark; Pierce, Sherry; Patel, Keyur P; Borthakur, Gautam; Ravandi, Farhad; Konopleva, Marina; Kornblau, Steven; Kantarjian, Hagop; Bhalla, Kapil; DiNardo, Courtney D

    2017-07-26

    (1) Runt-related transcription factor 1 (RUNX1) mutations in acute myeloid leukemia (AML) are often associated with worse prognosis. We assessed co-occurring mutations, response to therapy, and clinical outcomes in patients with and without mutant RUNX1 (mRUNX1); (2) We analyzed 328 AML patients, including 177 patients younger than 65 years who received intensive chemotherapy and 151 patients >65 years who received hypomethylating agents. RUNX1 and co-existing mutations were identified using next-generation sequencing; (3) RUNX1 mutations were identified in 5.1% of younger patients and 15.9% of older patients, and were significantly associated with increasing age (p = 0.01) as well as intermediate-risk cytogenetics including normal karyotype (p = 0.02) in the elderly cohort, and with lower lactate dehydrogenase (LDH; p = 0.02) and higher platelet count (p = 0.012) overall. Identified co-occurring mutations were primarily ASXL1 mutations in older patients and RAS mutations in younger patients; FLT3-ITD and IDH1/2 co-mutations were also frequent. Younger mRUNX1 AML patients treated with intensive chemotherapy experienced inferior treatment outcomes. In older patients with AML treated with hypomethylating agent (HMA) therapy, response and survival was independent of RUNX1 status. Older mRUNX1 patients with prior myelodysplastic syndrome or myeloproliferative neoplasms (MDS/MPN) had particularly dismal outcome. Future studies should focus on the prognostic implications of RUNX1 mutations relative to other co-occurring mutations, and the potential role of hypomethylating agents for this molecularly-defined group.

  4. Co-occurring intimate partner violence, mental health, and substance use problems: a scoping review.

    Science.gov (United States)

    Mason, Robin; O'Rinn, Susan E

    2014-12-01

    Background Intimate partner violence (IPV) is a pervasive, serious problem detrimental to the health of untold numbers of women. In addition to physical injuries that may be sustained, IPV has been significantly associated with mental health challenges including substance use problems. The problems are complex, highly correlated with each other, and bidirectional in nature. Although as many as 50% of women in mental health and between 25% and 50% of women in substance abuse treatment programs report IPV, frontline workers in all three sectors state they lack the training to address these co-occurring problems. Objective To determine what frontline IPV, mental health, and substance use workers need to know in order to provide appropriate care to women experiencing co-occurring IPV, mental health and/or substance use problems. Design Using Scholars Portal OVID, Medline and OVID PsycINFO and combinations of significant terms, we conducted a scoping review of articles published between 2005 and 2014. Results An initial 4017 records were retrieved (3484 from Scholars Portal, 272 from Medline, 261 from PsycINFO). After applying inclusion and exclusion criteria, 35 articles were reviewed. Of these, 14 examined the relationships among IPV, mental health, and substance use; 7 focused on IPV and mental health; 14 looked at IPV and substance use. Conclusions Although education and training frequently figured among the recommendations in the reviewed articles, specific content for proposed education or training was lacking. The most frequently occurring recommendations focused on the need to develop better collaboration, coordination, and integration across IPV, mental health and addiction treatment services.

  5. Does conflict control occur without awareness? Evidence from an ERP study.

    Science.gov (United States)

    Wang, Baoxi; Xiang, Ling; Li, Juan

    2013-01-15

    The relationship between conflict control and awareness has attracted extensive interest. Although researchers have investigated the relationship between response conflict and awareness, it still remains unclear whether stimulus conflict can occur outside of awareness. In addition, previous studies on the role of awareness in conflict control have ignored the fact that conflict control includes both conflict detection and resolution. A modified version of the flanker task was used to manipulate stimulus and response conflicts under both masked and unmasked conditions. The masked condition elicited a sequence of distinct event-related potential components that were also observed in the unmasked condition. N2 amplitudes presented the following pattern: incongruent-eligible>incongruent-ineligible>congruent, they did not show any difference under the masked and unmasked conditions, suggesting that detection of stimulus-related conflict revealed by the comparison between incongruent-ineligible and congruent trials, and response-related conflict revealed by the comparison between incongruent-eligible and incongruent-ineligible trials can occur in the absence of awareness, and unconscious conflict detection might involve the same neural network employed for conscious conflict detection. Late positive component (LPC) amplitudes also presented as incongruent-eligible>incongruent-ineligible>congruent at CPz and Pz, irrespective of conscious awareness. However, LPC amplitudes under the masked condition were markedly reduced compared to unmasked trials. These LPC findings suggest that stimulus- and response-related conflict resolution can occur in the absence of awareness; furthermore, unconscious conflict resolution might involve a weaker cognitive control network compared to conscious conflict resolution. These findings have important implications for the theories concerning the relationship between cognitive control and awareness.

  6. Mitochondrial acetoacetyl-CoA thiolase deficiency: basal ganglia impairment may occur independently of ketoacidosis.

    Science.gov (United States)

    Paquay, Stéphanie; Bourillon, Agnès; Pichard, Samia; Benoist, Jean-François; de Lonlay, Pascale; Dobbelaere, Dries; Fouilhoux, Alain; Guffon, Nathalie; Rouvet, Isabelle; Labarthe, François; Mention, Karine; Touati, Guy; Valayannopoulos, Vassili; Ogier de Baulny, Hélène; Elmaleh-Bergès, Monique; Acquaviva-Bourdain, Cécile; Vianey-Saban, Christine; Schiff, Manuel

    2017-05-01

    Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency affects ketone body and isoleucine catabolism. Neurological impairment may occur secondary to ketoacidotic episodes. However, we observed neuromotor abnormalities without ketoacidotic events in two T2-deficient families. We hypothesized that the neurological signs were related to the genetic defect and may occur independently of ketoacidotic episodes. We therefore conducted a retrospective review on a French T2-deficient patient series searching for neuromotor impairment. In total, 26 cases were retrospectively analysed for clinical, biological and neuroimaging data. Neurological findings were observed for 6/26 (23%) patients. Among these, two had never experienced ketoacidotic episodes, though they developed extrapyramidal signs with putamen involvement. Two of the other four patients developed neurological abnormalities before the first ketoacidotic crisis, with putamen involvement in one case. The third patient developed extrapyramidal symptoms more than 10 years after the initial decompensation with globus pallidus involvement. The last patient developed extrapyramidal signs immediately after a severe ketoacidotic crisis with putaminal lesions. Most T2-deficient patients achieved normal neurodevelopment. However, on account of the role of T2 in isoleucine catabolism, these patients are potentially exposed to accumulation of toxic isoleucine-derived metabolites, which may contribute to neurological impairment. Our findings confirm previous observations that neurological symptoms in T2 deficiency may occur unrelated to ketoacidosis. The role of protein restriction as a preventive measure against neurological symptoms could not be established in this study and deserves further evaluation. Long-term follow-up data on children diagnosed by newborn screening may clarify the pathogenesis of this neurometabolic association.

  7. Articular Osteochondrosis: A Comparison of Naturally-Occurring Human and Animal Disease

    Science.gov (United States)

    McCoy, Annette M; Toth, Ferenc; Dolvik, Nils I; Ekman, Stina; Ellermann, Jutta; Olstad, Kristin; Ytrehus, Bjornar; Carlson, Cathy S

    2013-01-01

    Background Osteochondrosis (OC) is a common developmental orthopedic disease affecting both humans and animals. Despite increasing recognition of this disease among children and adolescents, its pathogenesis is incompletely understood because clinical signs are often not apparent until lesions have progressed to end-stage, and examination of cadaveric early lesions is not feasible. In contrast, both naturally-occurring and surgically-induced animal models of disease have been extensively studied, most notably in horses and swine, species in which OC is recognized to have profound health and economic implications. The potential for a translational model of human OC has not been recognized in the existing human literature. Objective The purpose of this review is to highlight the similarities in signalment, predilection sites and clinical presentation of naturally-occurring OC in humans and animals and to propose a common pathogenesis for this condition across species. Study Design Review Methods The published human and veterinary literature for the various manifestations of OC was reviewed. Peer-reviewed original scientific articles and species-specific review articles accessible in PubMed (US National Library of Medicine) were eligible for inclusion. Results A broad range of similarities exists between OC affecting humans and animals, including predilection sites, clinical presentation, radiographic/MRI changes, and histological appearance of the end stage lesion, suggesting a shared pathogenesis across species. Conclusion This proposed shared pathogenesis for OC between species implies that naturally-occurring and surgically-induced models of OC in animals may be useful in determining risk factors and for testing new diagnostic and therapeutic interventions that can be used in humans. PMID:23954774

  8. Language Outcomes at 7 Years: Early Predictors and Co-Occurring Difficulties.

    Science.gov (United States)

    McKean, Cristina; Reilly, Sheena; Bavin, Edith L; Bretherton, Lesley; Cini, Eileen; Conway, Laura; Cook, Fallon; Eadie, Patricia; Prior, Margot; Wake, Melissa; Mensah, Fiona

    2017-03-01

    To examine at 7 years the language abilities of children, the salience of early life factors and language scores as predictors of language outcome, and co-occurring difficulties METHODS: A longitudinal cohort study of 1910 infants recruited at age 8 to 10 months. Exposures included early life factors (sex, prematurity, birth weight/order, twin birth, socioeconomic status, non-English speaking background,family history of speech/language difficulties); maternal factors (mental health, vocabulary, education, and age); and child language ability at 2 and 4 years. Outcomes were 7-year standardized receptive or expressive language scores (low language: ≥1.25 SD below the mean), and co-occurring difficulties (autism, literacy, social, emotional, and behavioral adjustment, and health-related quality of life). Almost 19% of children (22/1204;18.9%) met criteria for low language at 7 years. Early life factors explained 9-13% of variation in language scores, increasing to 39-58% when child language scores at ages 2 and 4 were included. Early life factors moderately discriminated between children with and without low language (area under the curve: 0.68-0.72), strengthening to good discrimination with language scores at ages 2 and 4 (area under the curve: 0.85-0.94). Low language at age 7 was associated with concurrent difficulties in literacy, social-emotional and behavioral difficulties, and limitations in school and psychosocial functioning. Child language ability at 4 years more accurately predicted low language at 7 than a range of early child, family, and environmental factors. Low language at 7 years was associated with a higher prevalence of co-occurring difficulties. Copyright © 2017 by the American Academy of Pediatrics.

  9. [Silica-associated systemic sclerosis occurring after an occupational exposure to arc welding].

    Science.gov (United States)

    Alaya, Zeineb; Kalboussi, Houda; Osman, Walid; Naouar, Nader; Zeglaoui, Héla; Bouajina, Elyès

    2016-01-01

    Crystalline silica-associated systemic sclerosis can occur in people operating arc welding. Diffuse scleroderma was diagnosed in a 57-year old plumber-welder suffering from inflammatory polyarthralgias, Raynaud's phenomenon, sclerodactyly, diffuse cutaneous scleroderma, telangiectasias, esophageal damage, pulmonary arterial hypertension and pulmonary fibrosis associated with the presence of anti-nucleosome antibodies. During his professional activity the patient was frequently exposed to high atmospheric concentrations of crystalline silica generated by arc-welding. The diagnosis of Erasmus syndrome associated with systemic sclerosis and pulmonary silicosis was retained. A report of work-related illness (table 17 in Tunisia) was made.

  10. STRING: a web-server to retrieve and display the repeatedly occurring neighbourhood of a gene.

    Science.gov (United States)

    Snel, B; Lehmann, G; Bork, P; Huynen, M A

    2000-09-15

    The repeated occurrence of genes in each other's neighbourhood on genomes has been shown to indicate a functional association between the proteins they encode. Here we introduce STRING (search tool for recurring instances of neighbouring genes), a tool to retrieve and display the genes a query gene repeatedly occurs with in clusters on the genome. The tool performs iterative searches and visualises the results in their genomic context. By finding the genomically associated genes for a query, it delineates a set of potentially functionally associated genes. The usefulness of STRING is illustrated with an example that suggests a functional context for an RNA methylase with unknown specificity.

  11. A Rare Case of Laparoscopic Repair of Simultaneously Occurring Morgagni and Paraesophageal Hernias.

    Science.gov (United States)

    Zhou, Zu-Li; Li, Hao; Li, Jian-Feng; Liu, Yan-Guo; Wang, Chong; Wang, Jun

    2016-01-01

    Simultaneously occurring Morgagni hernia and paraesophageal hernia is an extremely rare clinical condition with only six case reports in the English-language literature and only two laparoscopic repair reports. We report a 73-year-old woman with both Morgagni hernia and paraesophageal hernia who underwent successful laparoscopic repair of the hernia defects using transabdominal wall suturing. The laparoscopic operation can provide excellent exposure and repair the hernia defect easily with minimal invasiveness and fewer complications. This case report reported the concurring Morgagni and paraesophageal hernias and validated the feasibility of laparoscopic repair both hernias simultaneously.

  12. Leishmanicidal and cytotoxic activities of extracts and naturally-occurring compounds from two Lauraceae species.

    Science.gov (United States)

    Sánchez-Suárez, Jeysson; Coy-Barrera, Ericsson; Cuca, Luis Enrique; Delgado, Gabriela

    2011-02-01

    The in vitro leishmanicidal effects of ethanolic extracts and fifteen naturally-occurring compounds (five lignans, eight neolignans, a diterpene and a dihydrochalcone), obtained from Pleurothyrium cinereum and Ocotea macrophylla, were evaluated on promastigotes of Leishmania panamensis and L. braziliensis. In addition, in order to determine the selective action on Leishmania species as a safety principle, in vitro cytotoxicity on J774 cells was also evaluated for test compounds and extracts. One extract and seven compounds showed activity against Leishmania parasites at different levels. Dihydroflavokawin B (8) was found to be the most potent antileishmanial compound on both parasites, whilst (+)-otobaphenol (14), was found to be the most selective compound on L. panamensis.

  13. Ectomycorrhizal symbiosis in vitro between Tricholoma matsutake and Pinus densiflora seedlings that resembles naturally occurring 'shiro'.

    Science.gov (United States)

    Yamada, Akiyoshi; Maeda, Ken; Kobayashi, Hisayasu; Murata, Hitoshi

    2006-03-01

    We established an in vitro ectomycorrhizal symbiosis between Tricholoma matsutake and Pinus densiflora. Mycorrhiza formed in a substrate of Modified Norkrans' C medium and granite-based soil had features similar to those observed previously only in naturally occurring mycorrhizal system called 'shiro,' and promoted the growth of plants with smaller root/shoot ratios. The in vitro formation of 'shiro' is essential for the development of T. matsutake system to produce mushrooms and is useful for the propagation and plantation of the mycorrhizal seedlings.

  14. Pancreaticoduodenectomy for pancreas carcinoma occurring in the annular pancreas: report of a case.

    Science.gov (United States)

    Kawaida, Hiromichi; Kono, Hiroshi; Watanabe, Mitsuaki; Maki, Akira; Amemiya, Hidetake; Matsuda, Masanori; Fujii, Hideki; Fukasawa, Mitsuharu; Takahashi, Ei; Sano, Katsuhiro; Inoue, Tomohiro

    2015-08-01

    The annular pancreas is a rare congenital anomaly in which a ring of the pancreas parenchyma surrounds the second part of the duodenum. Malignant tumors are extremely rare in patients with an annular pancreas. A 64-year-old man presented with appetite loss and vomiting. Abdominal contrast-enhanced computed tomography (CT) indicated pancreas parenchyma surrounding the second part of the duodenum, and a hypovascular area occupying lesion in the annular pancreas. Subtotal stomach-preserving pancreaticoduodenectomy was performed. Histopathology showed pancreatic carcinoma occurring in the complete annular pancreas.

  15. A naturally-occurring ‘cold earth’ spot in Northern China

    OpenAIRE

    Fujun Niu; Guodong Cheng; Yonghong Niu; Mingyi Zhang; Jing Luo; Zhanju Lin

    2016-01-01

    Permafrost is determined to a large extent by the Earth’s surface temperature, therefore it distributes mainly in high altitude and latitude regions. However, stable, warm (about −1 °C) permafrost occurs within a scree slope in northern China that is more than 600 km south of the southernmost limit of latitudinal permafrost on the Eurasian Continent. It is at an elevation of only 900 m above sea level (ASL). The area has a mean annual air temperature (MAAT) of 6 to 8 °C. Thermal processes of ...

  16. Plasmodium falciparum malaria occurring four years after leaving an endemic area.

    Science.gov (United States)

    Vantomme, B; Van Acker, J; Rogge, S; Ommeslag, D; Donck, J; Callens, S

    2016-04-01

    We present a case of a 52-year-old woman of Ghanaian origin who developed Plasmodium falciparum malaria 4 years after leaving Africa. She had not returned to an endemic area since. We hypothesize several possible scenarios to explain this infection, of which we believe recrudescence of P. falciparum is the most plausible. This occurred most likely as a consequence of waning immunity several years after leaving a high-transmission area. She recovered after a 3-day treatment with atovaquone/proguanil.

  17. Characterization of naturally-occurring and modified fullerenes by Fourier transform mass spectrometry

    Science.gov (United States)

    Hettich, Robert L.; Jin, Changming; Compton, Robert N.; Buseck, Peter R.; Tsipursky, Semeon J.

    1993-10-01

    Fourier transform mass spectrometry (FTMS) employing both laser desorption/ionization and thermal desorption/electron ionization is useful for the detection and structural characterization of fullerenes and chemically-modified fullerenes. Examination of a carbon-rich shungite rock sample from Russia by transmission electron microscopy and FTMS provided evidence of naturally-occurring fullerenes. Ion-molecule reactions can be studied with FTMS to investigate the electron affinities of modified fullerenes. By monitoring charge exchange reactions, the electron affinities of C60Fx (x=44,46) and C70Fy (y=52,54) were found to be substantially higher than the values for the parent fullerenes.

  18. Naturally occurring bioactive Cyclobutane-containing (CBC) alkaloids in fungi, fungal endophytes, and plants.

    Science.gov (United States)

    Dembitsky, Valery M

    2014-10-15

    This article focuses on the occurrence and biological activities of cyclobutane-containing (CBC) alkaloids obtained from fungi, fungal endophytes, and plants. Naturally occurring CBC alkaloids are of particular interest because many of these compounds display important biological activities and possess antitumour, antibacterial, antimicrobial, antifungal, and immunosuppressive properties. Therefore, these compounds are of great interest in the fields of medicine, pharmacology, medicinal chemistry, and the pharmaceutical industry. Fermentation and production of CBC alkaloids by fungi and/or fungal endophytes is also discussed. This review presents the structures and describes the activities of 98 CBC alkaloids.

  19. Nuclear decay data for radionuclides occurring in routine releases from nuclear fuel cycle facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1977-08-01

    This report gives tabulations of the atomic and nuclear radiations emitted by 240 radionuclides. Most of the radionuclides are those expected to occur in routine releases of effluents from nuclear fuel cycle facilities. For each radionuclide are given the half-life and recommended values for the energies, intensities, and equilibrium absorbed-dose constants for each of the atomic and nuclear radiations. Also given are the daughter radionuclides produced and recommended values for decay branching ratios, where applicable. The radioactivity decay chains and branching ratios are displayed in diagram form.

  20. A Review on the Phytochemistry, Pharmacology, and Pharmacokinetics of Amentoflavone, a Naturally-Occurring Biflavonoid

    Directory of Open Access Journals (Sweden)

    Sheng Yu

    2017-02-01

    Full Text Available Amentoflavone (C30H18O10 is a well-known biflavonoid occurring in many natural plants. This polyphenolic compound has been discovered to have some important bioactivities, including anti-inflammation, anti-oxidation, anti-diabetes, and anti-senescence effects on many important reactions in the cardiovascular and central nervous system, etc. Over 120 plants have been found to contain this bioactive component, such as Selaginellaceae, Cupressaceae, Euphorbiaceae, Podocarpaceae, and Calophyllaceae plant families. This review paper aims to profile amentoflavone on its plant sources, natural derivatives, pharmacology, and pharmacokinetics, and to highlight some existing issues and perspectives in the future.

  1. A Statistical Investigation for Determining Fabric Defects That Occur During Weaving Production

    Directory of Open Access Journals (Sweden)

    Deniz Mutlu Ala

    2015-12-01

    Full Text Available Fabric defects that occur during weaving production causes wastage at garment production. If fabric defects can not be detected during garment production, causes separation of the finished product as second quality. In this study, in a weaving mill, raw fabrics were inspected during three weeks for defect detection after weaving operation and results were investigated using statistical methods. Detected fabric defects has been classified and noted on quality control charts. For statistical investigation of number of defects pareto analysis and p control charts were used from statistical process control methods.

  2. Can posterior hip fracture-dislocation occur in indoor football (futsal)? A report of two cases.

    Science.gov (United States)

    Yasin, Faissal Nor; Singh, Vivek Ajit

    2009-01-01

    Hip fracture-dislocation is extremely rare in sports and is most frequently seen after road traffic accidents. This injury is associated with considerable long-term disability and rapidly progressive joint degeneration. This case report illustrates two cases of hip fracture dislocation that occurred while playing recreational indoor football (futsal). Futsal is a fast-emerging recreational sport in Malaysia and we are now beginning to see high-impact injuries rarely encountered in recreational sports. Therefore, futsal cannot be taken lightly and it is important to take adequate precautions to prevent serious injuries when participating in such sports.

  3. Recent occurence of human infection by Rocio arbovirus in Ribeira Valley, Brazil

    Directory of Open Access Journals (Sweden)

    Lygia Busch Iversson

    1989-02-01

    Full Text Available The presence of IgM antibodies to Rocio in sera of two children from rural area of Ribeira Valley, Brazil, was detected by MAC-ELISA. This new arbovirus of the Flaviviridae family was responsible for an extensive encephalitis epidemic that occurred in the region in 1975-1977. Since 1980 no human disease caused by this virus has been diagnosed. An improvement on surveillance of Rocio infections and on the researches for virus identification in suspected vectors and reservoirs is necessary.

  4. Do all hemolytic anemias that occur after mitral valve repair require surgical treatment?

    Science.gov (United States)

    Gungunes, Askin; Akpinar, Ibrahim; Dogan, Mehmet; Baser, Kazim; Yildirim, Ismail Safa; Haznedaroglu, Ibrahim C

    2010-12-01

    We report on a 29-year-old woman with severe hemolytic anemia following mitral valve annuloplasty. Although hemolysis due to mechanical prosthetic mitral valve is well recognized, hemolytic anemia associated with mitral valve repair is an uncommon condition. Reoperation may be considered if the patient has serious and persistent anemia. Although valve replacement is suggested to be a unique intervention, it may not be the solution every time because of mechanical effects. Various mechanisms of hemolysis related to mitral valve repair were suggested, but sufficient and precise data is not available. In this case, we tried to emphasize whether all hemolytic anemias that occur after mitral valve repair require surgical treatment.

  5. Xylem and phloem phenology in co-occurring conifers exposed to drought

    OpenAIRE

    Swidrak, Irene; GRUBER, Andreas; Oberhuber, Walter

    2014-01-01

    Key message Variability in xylem and phloem phenology among years and species is caused by contrasting temperatures prevailing at the start of the growing season and species-specific sensitivity to drought. Abstract The focus of this study was to determine temporal dynamics of xylem and phloem formation in co-occurring deciduous and evergreen coniferous species in a dry inner Alpine environment (750 m a.s.l., Tyrol, Austria). By repeated micro-sampling of the stem, timing of key phenological ...

  6. Naturally occurring phenanthrene degrading bacteria associated with seeds of various plant species.

    Science.gov (United States)

    Fernet, Jennifer L; Lawrence, John R; Germida, James J

    2016-01-01

    Seeds of 11 of 19 plant species tested yielded naturally occurring phenanthrene degrading bacteria when placed on phenanthrene impression plates. Seed associated phenanthrene degrading bacteria were mostly detected on caragana, Canada thistle, creeping red fescue, western wheatgrass, and tall wheat grass. Based on 16S rRNA analysis the most common bacteria isolated from these seeds were strains belonging to the genera Enterobacteria, Erwinia, Burkholderia, Pantoea, Pseudomonas, and Sphingomonas. These plants may provide an excellent source of pre-adapted bacterial-plant associations highly suitable for use in remediation of contaminated soil environments.

  7. Occupational exposure due to naturally occurring radionuclide material in granite quarry industry.

    Science.gov (United States)

    Ademola, J A

    2012-02-01

    The potential occupational exposure in granite quarry industry due to the presence of naturally occurring radioactive material (NORM) has been investigated. The activity concentrations of (40)K, (226)Ra and (232)Th were determined using gamma-ray spectroscopy method. The annual effective dose of workers through different exposure pathways was determined by model calculations. The total annual effective dose varied from 21.48 to 33.69 μSv y(-1). Inhalation dose contributes the highest to the total effective dose. The results obtained were much lower than the intervention exemption levels (1.0 mSv y(-1)) given in the International Commission on Radiological Protection Publication 82.

  8. The new IAEA reference material: IAEA-434 technologically enhanced naturally occurring radioactive materials (TENORM) in phosphogypsum

    Energy Technology Data Exchange (ETDEWEB)

    Shakhashiro, A., E-mail: A.Shakhashiro@iaea.or [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Sansone, U. [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Wershofen, H. [Environmental Radioactivity, PTP, Braunschweig (Germany); Bollhoefer, A. [Environmental Radioactivity, Department of the Environment and Heritage, Darwin (Australia); Kim, C.K. [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Kim, C.S. [Department of Environmental Radioactivity Assessment, Korea Institute of Nuclear Safety, Daejeon, Republic of Korea (Former collaborator) (Korea, Republic of); Kis-Benedek, G. [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Korun, M. [Jozef Stefan Institute, Ljubljana (Slovenia); Moune, M. [LNE-LNHB, Laboratoire National Henri Becquerel, Gif-sur-Yvette Cedex (France); Lee, S.H. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Tarjan, S. [Central Radiological Laboratory, Hungarian Agricultural Authority, Budapest (Hungary); Al-Masri, M.S. [Atomic Energy Commission of Syria, Damascus (Syrian Arab Republic)

    2011-01-15

    A reliable determination of Technologically Enhanced Naturally Occurring Radioactive Materials in phosphogypsum is necessary to comply with radiation protection and environmental regulations. In this respect, a new phosphogypsum reference material was produced and certified to assist in the validation of analytical methods and the quality assurance of produced analytical results. This paper presents the sample preparation methodology, material homogeneity assessment, characterization campaign results and assignment of property values, and associated uncertainties. The reference values and associated uncertainties for Pb-210, Ra-226, Th-230, U-234 and U-238 were established based on consensus values calculated from analytical results reported by three National Metrology Institutes and five expert laboratories.

  9. Activity measurements of technically enhanced naturally occurring radionuclides (TENORM) in phosphogypsum

    Energy Technology Data Exchange (ETDEWEB)

    Luca, A. [Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), 407 Atomistilor Street, P.O. Box MG-6, Postcode 077125, Magurele, Ilfov County (Romania)], E-mail: aluca@ifin.nipne.ro; Margineanu, R.; Sahagia, M.; Waetjen, A.C. [Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), 407 Atomistilor Street, P.O. Box MG-6, Postcode 077125, Magurele, Ilfov County (Romania)

    2009-05-15

    Phosphogypsum is a by-product of the phosphoric acid based fertilizer industry; it can be used in agriculture and to make building materials. Phosphogypsum is radioactive due to the presence of technically enhanced naturally occurring radionuclides (TENORM) and its environmental impact is a major concern of the public authorities. The Radionuclide Metrology Laboratory from IFIN-HH participated at the IAEA-CU-2007-06-CCRI(II)-S5 Supplementary Comparison for the Determination of TENORM in phosphogypsum. The measurement procedures and the discussion of results and problems encountered are presented.

  10. Heat-shock-induced cellular responses to temperature elevations occurring during orthopaedic cutting

    OpenAIRE

    Dolan, E. B.; Haugh, M. G.; Tallon, D.; Casey, C.; McNamara, L.M.

    2012-01-01

    Severe heat-shock to bone cells caused during orthopaedic procedures can result in thermal damage, leading to cell death and initiating bone resorption. By contrast, mild heat-shock has been proposed to induce bone regeneration. In this study, bone cells are exposed to heat-shock for short durations occurring during surgical cutting. Cellular viability, necrosis and apoptosis are investigated immediately after heat-shock and following recovery of 12, 24 h and 4 days, in osteocyte-like MLO-Y4 ...

  11. Bibliography of reports, papers, and presentations on naturally occurring radioactive material (NORM) in petroleum industry wastes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.P.; Wilkey, M.L.; Hames, R.D.

    1997-07-01

    This bibliography was created to support projects conducted by Argonne National Laboratory (ANL) addressing issues related to naturally occurring radioactive material (NORM) in petroleum industry wastes. The bibliography provides citations for many of the available published reports, papers, articles, and presentations on petroleum industry NORM. In the past few years, the rapid expansion of NORM treatment and disposal technologies, the efforts to characterize NORM wastes and their associated potential risks, and the promulgation of state-level NORM regulatory programs have been well-documented in project reports and in papers presented at technical conferences and symposia. There are 221 citations.

  12. The new IAEA reference material: IAEA-434 technologically enhanced naturally occurring radioactive materials (TENORM) in phosphogypsum.

    Science.gov (United States)

    Shakhashiro, A; Sansone, U; Wershofen, H; Bollhöfer, A; Kim, C K; Kim, C S; Kis-Benedek, G; Korun, M; Moune, M; Lee, S H; Tarjan, S; Al-Masri, M S

    2011-01-01

    A reliable determination of Technologically Enhanced Naturally Occurring Radioactive Materials in phosphogypsum is necessary to comply with radiation protection and environmental regulations. In this respect, a new phosphogypsum reference material was produced and certified to assist in the validation of analytical methods and the quality assurance of produced analytical results. This paper presents the sample preparation methodology, material homogeneity assessment, characterization campaign results and assignment of property values, and associated uncertainties. The reference values and associated uncertainties for Pb-210, Ra-226, Th-230, U-234 and U-238 were established based on consensus values calculated from analytical results reported by three National Metrology Institutes and five expert laboratories.

  13. Activity measurements of technically enhanced naturally occurring radionuclides (TENORM) in phosphogypsum.

    Science.gov (United States)

    Luca, A; Margineanu, R; Sahagia, M; Wätjen, A C

    2009-05-01

    Phosphogypsum is a by-product of the phosphoric acid based fertilizer industry; it can be used in agriculture and to make building materials. Phosphogypsum is radioactive due to the presence of technically enhanced naturally occurring radionuclides (TENORM) and its environmental impact is a major concern of the public authorities. The Radionuclide Metrology Laboratory from IFIN-HH participated at the IAEA-CU-2007-06-CCRI(II)-S5 Supplementary Comparison for the Determination of TENORM in phosphogypsum. The measurement procedures and the discussion of results and problems encountered are presented.

  14. Synthesis and anti-cancer activity of naturally occurring 2,5-diketopiperazines.

    Science.gov (United States)

    Mollica, Adriano; Costante, Roberto; Fiorito, Serena; Genovese, Salvatore; Stefanucci, Azzurra; Mathieu, Veronique; Kiss, Robert; Epifano, Francesco

    2014-10-01

    Three naturally occurring oxyprenylated diketopiperazines were synthesized and preliminarily tested as growth inhibitory agents in vitro against various cancer cell lines. The compounds were tested on six human cancer cell lines with different sensitivity to proapoptotic stimuli using the MTT colorimetric assay. The data revealed that of the chemicals under study only deoxymicelianamide (11) displayed the highest activity, recording mean IC50 growth inhibitory values ranging from 2 to 23 μM. A comparative study with the non-geranylated saturated derivative of (11) revealed the importance of the presence of the geranyloxy side chain and the exocyclic 2,5-DPK double bond moiety for the observed activity.

  15. Inflammatory fibroid polyp occurring in the transverse colon diagnosed by endoscopic biopsy

    Institute of Scientific and Technical Information of China (English)

    Shoji Hirasaki; Minoru Matsubara; Fusao Ikeda; Hideaki Taniguchi; Seiyuu Suzuki

    2007-01-01

    A case of an inflammatory fibroid polyp occurring in the transverse colon and diagnosed by endoscopic biopsy is reported. The patient was an 82-year-old man who visited our hospital for further evaluation of occult blood in stool. The Colonoscopy revealed a small,red, and peduncular polyp, about 6 mm in diameter,in the transverse colon. Histological examination of the biopsy specimen obtained from the polyp revealed proliferation of fibroblasts and infiltration of inflammatory cells such as plasma cells and eosinophils. This polyp was diagnosed as an inflammatory fibroid polyp, which can appear in many different locations throughout gastrointestinal tract, though still rare in the transverse colon.

  16. Stereoskooppisen vaha-animaation jälkikäsittely : Case: Nothing Occurred

    OpenAIRE

    2012-01-01

    Tässä opinnäytetyössä keskitytään haasteisiin, joita stereoskooppinen kuva tuo visuaalisten tehosteiden lisäämiseen ja työnkulkuun. Produktiivinen osio on Nothing Occurred -animaatio, joka on opinnäytetyön kirjoittajan voittoa tavoittelematon pienen budjetin stereoskooppinen vaha-animaatio. Sen esikuvana on Coraline-animaatio, joka on maailman ensimmäinen kokoillan stereoskooppinen stop motion -elokuva. Työssä tutkitaan alan teoriaa ja kirjoittajan omia havaintoja 3D-elokuvista sekä empii...

  17. Solar Interactions on Spiral Petroglyphs

    Science.gov (United States)

    Davis, Brian F.; Preston, Robert A.

    2003-11-01

    Like most prehistoric cultures, the ancestors of the native Puebloan people of the Southwest were aware of the yearly cycle of the sun. This and other natural phenomena are fundamental for interpreting their world view, religion, and art. Some researchers have argued that rock art, particularly petroglyphs, displays this focus on the natural world through the distinctive interplay of sunlight on these carvings. However, the question of whether or not these interactions occur by intention or chance has hampered the acceptance of this evidence by the archaeological community. To address this question we have performed a detailed study of a complete sample of over 100 spiral petroglyphs within a limited area (less than 20 km^2) of central New Mexico. We have examined this sample on both solstices and equinoxes, and have observed well-defined and consistent sunlight interactions on about 80This work clearly demonstrates the reality and profusion of this ancient cultural tradition. Several examples will be presented.

  18. PIC: Protein Interactions Calculator.

    Science.gov (United States)

    Tina, K G; Bhadra, R; Srinivasan, N

    2007-07-01

    Interactions within a protein structure and interactions between proteins in an assembly are essential considerations in understanding molecular basis of stability and functions of proteins and their complexes. There are several weak and strong interactions that render stability to a protein structure or an assembly. Protein Interactions Calculator (PIC) is a server which, given the coordinate set of 3D structure of a protein or an assembly, computes various interactions such as disulphide bonds, interactions between hydrophobic residues, ionic interactions, hydrogen bonds, aromatic-aromatic interactions, aromatic-sulphur interactions and cation-pi interactions within a protein or between proteins in a complex. Interactions are calculated on the basis of standard, published criteria. The identified interactions between residues can be visualized using a RasMol and Jmol interface. The advantage with PIC server is the easy availability of inter-residue interaction calculations in a single site. It also determines the accessible surface area and residue-depth, which is the distance of a residue from the surface of the protein. User can also recognize specific kind of interactions, such as apolar-apolar residue interactions or ionic interactions, that are formed between buried or exposed residues or near the surface or deep inside.

  19. Designing for mobile interaction

    DEFF Research Database (Denmark)

    Nazzi, Elena

    2009-01-01

    The theme of this PhD project is designing for mobile interaction with devices and services, for the accessing, making, and sharing of information, taking into account the dynamic physical and social settings that embrace this interaction. To narrow down this theme, the whole project focuses...... on the exploitation of social interaction --- in particular among senior citizens --- to enhance and support mobile interaction....

  20. Interactive pinball business

    DEFF Research Database (Denmark)

    Buur, Jacob; Gudiksen, Sune Klok

    2012-01-01

    Interaction design expands into new fields. Interaction design and business model innovation is a promising meeting of disciplines: Many businesses see the need to rethink their ways of doing business, and, as business models pose highly dynamic and interactive problems, interaction design has much...

  1. Altered lipid composition in cortical lipid rafts occurs at early stages of sporadic Alzheimer's disease and facilitates APP/BACE1 interactions.

    Science.gov (United States)

    Fabelo, Noemí; Martín, Virginia; Marín, Raquel; Moreno, Dolores; Ferrer, Isidre; Díaz, Mario

    2014-08-01

    The presence of lipid alterations in lipid rafts from the frontal cortex in late stages of Alzheimer's disease (AD) has been recently demonstrated. Here, we have isolated and analyzed the lipid composition of lipid rafts from different brain areas from control and AD subjects at initial neuropathologic stages. We have observed that frontal cortex lipid rafts are profoundly altered in AD brains from the earliest stages of AD, namely AD I/II. These changes in the lipid matrix of lipid rafts affected both lipid classes and fatty acids and were also detected in the entorhinal cortex, but not in the cerebellum from the same subjects. Paralleling these changes, lipid rafts from AD frontal and entorhinal cortices displayed higher anisotropy for environment-sensitive probes, indicating that lipid changes in AD lipid rafts increased membrane order and viscosity in these domains. The pathophysiological consequences of these alterations in the development and progression of AD were strengthened by the significant, and specific, accumulation of β-secretase within the lipid rafts of AD subjects even at the earliest stages. Our results provide a mechanistic connection between lipid alterations in these microdomains and amyloidogenic processing of amyloid precursor protein.

  2. Original mechanism of failure initiation revealed through modelling of naturally occurring microstructures

    Science.gov (United States)

    Gorbatikh, Larissa; Lomov, Stepan V.; Verpoest, Ignaas

    2010-05-01

    Motivated to reveal original mechanisms of failure resistance, we developed a material model that encompasses most reoccurring microstructural features of natural composites. The interesting result of the work is a notion that material failure is governed by the quality of interactions between hierarchical levels in the material microstructure. With intelligent use of the structure, these interactions can be tuned to create a powerful synergetic effect on the material failure behaviour. For example, while exploring different mechanisms of failure initiation in composites with bimodal size reinforcements (an indirect way to model two levels of hierarchy simultaneously) we found that failure initiation could be shifted from stress concentration sites of the higher level to the lower level. One could say that the material behaviour became insensitive to the presence of reinforcements on the higher level—a phenomenon that is counterintuitive to what is commonly known. The new mechanism of failure initiation could only be activated in composites with a highly controlled structural organization—in the studied case, reinforcements of the lower level needed to establish lamellar pathways between reinforcements of the higher level. These pathways lead to formation of an intriguing network-like microstructure. Intelligent communication between reinforcements in such a network created the necessary synergy to change the failure initiation mechanism in a discontinuous fashion. Another finding was that by establishing such a network, tensile stresses near dangerous stress concentration sites were locally transformed into compressive stresses. Resemblance of the revealed mechanism to phenomena on the nano-scale was also discussed. In the course of this work a new method was developed to investigate interactions between reinforcements and their collective input into effective and local properties of a composite. The reinforcement phase was modelled with the use of rigid

  3. Plum Fruit Development Occurs via Gibberellin-Sensitive and -Insensitive DELLA Repressors.

    Science.gov (United States)

    El-Sharkawy, Islam; Sherif, Sherif; Abdulla, Mahboob; Jayasankar, Subramanian

    2017-01-01

    Fruit growth depends on highly coordinated hormonal activities. The phytohormone gibberellin (GA) promotes growth by triggering degradation of the growth-repressing DELLA proteins; however, the extent to which such proteins contribute to GA-mediated fruit development remains to be clarified. Three new plum genes encoding DELLA proteins, PslGAI, PslRGL and PslRGA were isolated and functionally characterized. Analysis of expression profile during fruit development suggested that PslDELLA are transcriptionally regulated during flower and fruit ontogeny with potential positive regulation by GA and ethylene, depending on organ and developmental stage. PslGAI and PslRGL deduced proteins contain all domains present in typical DELLA proteins. However, PslRGA exhibited a degenerated DELLA domain and subsequently lacks in GID1-DELLA interaction property. PslDELLA-overexpression in WT Arabidopsis caused dramatic disruption in overall growth including root length, stem elongation, plant architecture, flower structure, fertility, and considerable retardation in development due to dramatic distortion in GA-metabolic pathway. GA treatment enhanced PslGAI/PslRGL interaction with PslGID1 receptors, causing protein destabilization and relief of growth-restraining effect. By contrast, PslRGA protein was not degraded by GA due to its inability to interact with PslGID1. Relative to other PslDELLA-mutants, PslRGA-plants displayed stronger constitutive repressive growth that was irreversible by GA application. The present results describe additional complexities in GA-signalling during plum fruit development, which may be particularly important to optimize successful reproductive growth.

  4. Plum Fruit Development Occurs via Gibberellin–Sensitive and –Insensitive DELLA Repressors

    Science.gov (United States)

    El-Sharkawy, Islam; Sherif, Sherif; Abdulla, Mahboob

    2017-01-01

    Fruit growth depends on highly coordinated hormonal activities. The phytohormone gibberellin (GA) promotes growth by triggering degradation of the growth-repressing DELLA proteins; however, the extent to which such proteins contribute to GA-mediated fruit development remains to be clarified. Three new plum genes encoding DELLA proteins, PslGAI, PslRGL and PslRGA were isolated and functionally characterized. Analysis of expression profile during fruit development suggested that PslDELLA are transcriptionally regulated during flower and fruit ontogeny with potential positive regulation by GA and ethylene, depending on organ and developmental stage. PslGAI and PslRGL deduced proteins contain all domains present in typical DELLA proteins. However, PslRGA exhibited a degenerated DELLA domain and subsequently lacks in GID1–DELLA interaction property. PslDELLA–overexpression in WT Arabidopsis caused dramatic disruption in overall growth including root length, stem elongation, plant architecture, flower structure, fertility, and considerable retardation in development due to dramatic distortion in GA-metabolic pathway. GA treatment enhanced PslGAI/PslRGL interaction with PslGID1 receptors, causing protein destabilization and relief of growth-restraining effect. By contrast, PslRGA protein was not degraded by GA due to its inability to interact with PslGID1. Relative to other PslDELLA–mutants, PslRGA–plants displayed stronger constitutive repressive growth that was irreversible by GA application. The present results describe additional complexities in GA-signalling during plum fruit development, which may be particularly important to optimize successful reproductive growth. PMID:28076366

  5. Interaction for visualization

    CERN Document Server

    Tominski, Christian

    2015-01-01

    Visualization has become a valuable means for data exploration and analysis. Interactive visualization combines expressive graphical representations and effective user interaction. Although interaction is an important component of visualization approaches, much of the visualization literature tends to pay more attention to the graphical representation than to interaction.The goal of this work is to strengthen the interaction side of visualization. Based on a brief review of general aspects of interaction, we develop an interaction-oriented view on visualization. This view comprises five key as

  6. Differential CCR7 Targeting in Dendritic Cells by Three Naturally Occurring CC-Chemokines

    DEFF Research Database (Denmark)

    Hjorto, Gertrud M.; Larsen, Olav; Steen, Anne;

    2016-01-01

    The CCR7 ligands CCL19 and CCL21 are increasingly recognized as functionally different (biased). Using mature human dendritic cells (DCs), we show that CCL19 is more potent than CCL21 in inducing 3D chemotaxis. Intriguingly, CCL21 induces prolonged and more efficient ERK1/2 activation compared...... identify a molecular switch in the top of TM7 important for keeping CCR7 in an inactive conformation (Tyr312), as introduction of the chemokine receptor-conserved Glu (or Ala) induces high constitutive activity. Summarized, we show that the interaction of the tail of CCL21 with polysialic acid is needed...

  7. A Critical Analysis of the Environments, Reasons and Constraints for which Naturalistic Codeswitching Occurs

    Institute of Scientific and Technical Information of China (English)

    HUANG Fei-fei

    2013-01-01

    Naturalistic codeswitching is a normal and powerful communicative feature of formal or informal bilingual interac-tions, which present linguists with part of their most fascinating analytical challenge. People use codeswitching in various commu-nication environments such as in bilingual families or immigrant contexts for effective information exchange. The present article investigates the environments and reasons for occurrence of naturalistic codeswitching and analyzes the linguistic constraints and social constraints on naturalistic codeswitching with examples. A more thorough and authentic assessment of individuals ’linguis-tic knowledge about codeswitching, as well as individuals’codeswitching habits, must include observations of codeswitching be-havior in naturalistic environments.

  8. Correlated interaction fluctuations in photosynthetic complexes

    CERN Document Server

    Vlaming, Sebastiaan M

    2011-01-01

    The functioning and efficiency of natural photosynthetic complexes is strongly influenced by their embedding in a noisy protein environment, which can even serve to enhance the transport efficiency. Interactions with the environment induce fluctuations of the transition energies of and interactions between the chlorophyll molecules, and due to the fact that different fluctuations will partially be caused by the same environmental factors, correlations between the various fluctuations will occur. We argue that fluctuations of the interactions should in general not be neglected, as these have a considerable impact on population transfer rates, decoherence rates and the efficiency of photosynthetic complexes. Furthermore, while correlations between transition energy fluctuations have been studied, we provide the first quantitative study of the effect of correlations between interaction fluctuations and transition energy fluctuations, and of correlations between the various interaction fluctuations. It is shown t...

  9. Dynamical Models of Dyadic Interactions with Delay

    CERN Document Server

    Bielczyk, Natalia; Płatkowski, Tadeusz

    2012-01-01

    When interpersonal interactions between individuals are described by the (discrete or continuous) dynamical systems, the interactions are usually assumed to be instantaneous: the rates of change of the actual states of the actors at given instant of time are assumed to depend on their states at the same time. In reality the natural time delay should be included in the corresponding models. We investigate a general class of linear models of dyadic interactions with a constant discrete time delay. We prove that in such models the changes of stability of the stationary points from instability to stability or vice versa occur for various intervals of the parameters which determine the intensity of interactions. The conditions guaranteeing arbitrary number (zero, one ore more) of switches are formulated and the relevant theorems are proved. A systematic analysis of all generic cases is carried out. It is obvious that the dynamics of interactions depend both on the strength of reactions of partners on their own sta...

  10. A case of adenocarcinoma occurred at site of radiated double-barrel sigmoid colostomy

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Hideaki; Kondo, Yukifumi; Takahashi, Masatoshi [Sapporo-Kosei General Hospital (Japan)] [and others

    1996-10-01

    A 60-year-old female developed an adenocarcinoma at the site of double-barrel sigmoid colostomy. She underwent a total hysterectomy and the subsequent radiation therapy due to carcinoma uteri when she was 34 years old. She had rectal stenosis one year later and underwent sigmoid colostomy. She had been healthy thereafter, however, when she was 58 years old, she noticed an elevated lesion at the site of colostomy. Biopsy revealed well-differentiated adenocarcinoma, so surgery was recommended but she refused it. Two years later, the entire stoma became a carcinoma, which directly invaded the abdominal wall on MRI images. A bow-shaped skin incision was made and en bloc resection of the tumor, colostomy and the surrounding tissues was performed. Finally, descending colostomy in the left upper quadrant of the abdomen was reconstructed. Primary adenocarcinoma occurring at a double-barrel colostomy is very rare, and such a case may never have been reported, although there were some reports of carcinoma occurring at an end colostomy. Since the site of the present carcinoma was radiated, the radiation may contribute to this carcinogenesis, suspecting its late effect. Our surgical procedure enabled simultaneously operation of combined resection and intraabdominal manipulation, and the reconstruction site of the stoma was easily selected. (author)

  11. Space use variation in co-occurring sister species: response to environmental variation or competition?

    Science.gov (United States)

    Dufour, Claire M S; Meynard, Christine; Watson, Johan; Rioux, Camille; Benhamou, Simon; Perez, Julie; du Plessis, Jurie J; Avenant, Nico; Pillay, Neville; Ganem, Guila

    2015-01-01

    Coexistence often involves niche differentiation either as the result of environmental divergence, or in response to competition. Disentangling the causes of such divergence requires that environmental variation across space is taken into account, which is rarely done in empirical studies. We address the role of environmental variation versus competition in coexistence between two rodent species: Rhabdomys bechuanae (bechuanae) and Rhabdomys dilectus dilectus (dilectus) comparing their habitat preference and home range (HR) size in areas with similar climates, where their distributions abut (allopatry) or overlap (sympatry). Using Outlying Mean Index analyses, we test whether habitat characteristics of the species deviate significantly from a random sample of available habitats. In allopatry, results suggest habitat selection: dilectus preferring grasslands with little bare soil while bechuanae occurring in open shrublands. In sympatry, shrubland type habitats dominate and differences are less marked, yet dilectus selects habitats with more cover than bechuanae. Interestingly, bechuanae shows larger HRs than dilectus, and both species display larger HRs in sympatry. Further, HR overlaps between species are lower than expected. We discuss our results in light of data on the phylogeography of the genus and propose that evolution in allopatry resulted in adaptation leading to different habitat preferences, even at their distribution margins, a divergence expected to facilitate coexistence. However, since sympatry occurs in sites where environmental characteristics do not allow complete species separation, competition may explain reduced inter-species overlap and character displacement in HR size. This study reveals that both environmental variation and competition may shape species coexistence.

  12. Space use variation in co-occurring sister species: response to environmental variation or competition?

    Directory of Open Access Journals (Sweden)

    Claire M S Dufour

    Full Text Available Coexistence often involves niche differentiation either as the result of environmental divergence, or in response to competition. Disentangling the causes of such divergence requires that environmental variation across space is taken into account, which is rarely done in empirical studies. We address the role of environmental variation versus competition in coexistence between two rodent species: Rhabdomys bechuanae (bechuanae and Rhabdomys dilectus dilectus (dilectus comparing their habitat preference and home range (HR size in areas with similar climates, where their distributions abut (allopatry or overlap (sympatry. Using Outlying Mean Index analyses, we test whether habitat characteristics of the species deviate significantly from a random sample of available habitats. In allopatry, results suggest habitat selection: dilectus preferring grasslands with little bare soil while bechuanae occurring in open shrublands. In sympatry, shrubland type habitats dominate and differences are less marked, yet dilectus selects habitats with more cover than bechuanae. Interestingly, bechuanae shows larger HRs than dilectus, and both species display larger HRs in sympatry. Further, HR overlaps between species are lower than expected. We discuss our results in light of data on the phylogeography of the genus and propose that evolution in allopatry resulted in adaptation leading to different habitat preferences, even at their distribution margins, a divergence expected to facilitate coexistence. However, since sympatry occurs in sites where environmental characteristics do not allow complete species separation, competition may explain reduced inter-species overlap and character displacement in HR size. This study reveals that both environmental variation and competition may shape species coexistence.

  13. Serum canine pancreatic lipase immunoreactivity in experimentally induced and naturally occurring canine monocytic ehrlichiosis (Ehrlichia canis).

    Science.gov (United States)

    Mylonakis, Mathios E; Xenoulis, Panagiotis G; Theodorou, Konstantina; Siarkou, Victoria I; Steiner, Jörg M; Harrus, Shimon; Leontides, Leonidas; Rallis, Timoleon; Suchodolski, Jan S; Koutinas, Christos K; Koutinas, Alexander F

    2014-03-14

    Ehrlichia canis infection causes multisystemic disease in dogs (canine monocytic ehrlichiosis, CME) which is associated with variable morbidity and mortality. Atypical clinical manifestations, including gastrointestinal signs, may occasionally occur in CME and approximately 10-15% of dogs are presented with historical or clinical evidence of vomiting, diarrhea, and/or abdominal discomfort. The objective of this study was to investigate if there are any alterations in serum canine pancreatic lipase immunoreactivity (cPLI) in dogs with experimentally induced or naturally occurring monocytic ehrlichiosis. Serum samples from 10 Beagle dogs experimentally infected with E. canis and two healthy uninfected Beagles were serially examined; samples from 20 naturally infected dogs (10 with non-myelosuppressive [NME] and 10 with myelosuppressive [ME] ehrlichiosis) were also examined at a given point in time (cross-sectional sampling). None of the experimentally infected Beagles showed gastrointestinal signs or increased cPLI concentrations prior to or following the artificial infection. Three naturally infected dogs with NME and one with ME demonstrated serum cPLI concentrations in the diagnostic range for pancreatitis (>400 μg/L) without showing gastrointestinal signs. The results of the present study indicated that 4/20 (20%) of dogs naturally infected with E. canis demonstrated increased serum cPLI concentrations consistent with mild and clinically inapparent pancreatitis.

  14. Significant skin burns may occur with the use of a water balloon in HIFU treatment

    Science.gov (United States)

    Ritchie, Robert; Collin, Jamie; Wu, Feng; Coussios, Constantin; Leslie, Tom; Cranston, David

    2012-10-01

    HIFU is a minimally-invasive therapy suitable for treating selected intra-abdominal tumors. Treatment is safe although skin burns may occur due to pre-focal heating. HIFU treatment of a renal transplant tumor located in the left lower abdomen was undertaken in our centre. Treatment was performed prone, requiring displacement of the abdominal wall away from the treatment field using a water balloon, constructed of natural rubber latex and filled with degassed water. Intra-operatively, ultrasound imaging and physical examination of the skin directly over the focal region was normal. Immediately post-operative, a full-thickness skin burn was evident at the periphery of the balloon location, outside the expected HIFU path. Three possibilities may account for this complication. Firstly, the water balloon may have acted as a lens, focusing the HIFU to a neo-focus off axis. Secondly, air bubbles may have been entrapped between the balloon and the skin, causing heating at the interface. Finally, heating of the isolated water within the balloon may have been sufficient to cause burning. In this case, the placement of a water balloon caused a significant skin burn. Care should be taken in their use as burns, situated off axis, may occur even if the overlying skin appears normal.

  15. The influence of selected socio-demographic variables on symptoms occurring during the menopause.

    Science.gov (United States)

    Makara-Studzińska, Marta; Kryś-Noszczyka, Karolina; Jakiel, Grzegorz

    2015-03-01

    It is considered that the lifestyle conditioned by socio-demographic or socio-economic factors determines the health condition of people to the greatest extent. The aim of this study is to evaluate the influence of selected socio-demographic factors on the kinds of symptoms occurring during menopause. The study group consisted of 210 women aged 45 to 65, not using hormone replacement therapy, staying at healthcare centers for rehabilitation treatment. The study was carried out in 2013-2014 in the Silesian, Podlaskie and Lesser Poland voivodeships. The set of tools consisted of the authors' own survey questionnaire and the Menopause Rating Scale (MRS). The most commonly occurring symptom in the group of studied women was a depressive mood, from the group of psychological symptoms, followed by physical and mental fatigue, and discomfort connected with muscle and joint pain. The greatest intensity of symptoms was observed in the group of women with the lowest level of education, reporting an average or bad material situation, and unemployed women. An alarmingly high number of reported psychological symptoms in the group of menopausal women was observed, and in particular among the group of low socio-economic status. Career seems to be a factor reducing the risk of occurrence of psychological symptoms. There is an urgent need for health promotion and prophylaxis in the group of menopausal women, and in many cases for implementation of specialist psychological assistance.

  16. Bronchial hyperreactivity occurs in steroid-treated guinea pigs depleted of leukocytes by cyclophosphamide

    Energy Technology Data Exchange (ETDEWEB)

    Murlas, C.; Roum, J.H.

    1985-05-01

    The effects of cyclophosphamide and cortisone acetate treatment on O/sub 3/-induced changes in airway mucosal morphology and bronchial reactivity were assessed in guinea pigs. Animals in groups of four were studied at 2 or 6 h after O/sub 3/ (3.0 ppm, 2 h) and in one control group. Reactivity was determined by measuring specific airway resistance during intravenous acetylcholine infusion in intact, unanesthetized, spontaneously breathing animals. After testing, tracheal tissue was obtained from all animals for light microscopic examination. Another group of 10 drug-treated and 10 normal animals were tested at 2 h, 6 h, 1 day, and 4 days after O/sub 3/. Drug treatment resulted in substantial decreases in both circulating and airway mucosal granulocytes. Two hours after O/sub 3/, a marked decrease in airway mucosal goblet cells as well as ciliated cell damage occurred in both normal and treated animals. However, only in normal animals did neutrophilic infiltration develop thereafter. Nonetheless, hyperreactivity postozone occurred and progressed similarly in both groups. Our results indicate that acute O/sub 3/-induced bronchial hyperreactivity at 2 h is associated with signs of airway mucosal injury but appears independent of granulocyte changes. Airway neutrophilic infiltration and eosinophil depletion seem to be consequences of mucosal injury from O/sub 3/ and not causes of the bronchial hyperreactivity that results.

  17. Cannabis, Cigarettes, and Their Co-Occurring Use: Disentangling Differences in Gray Matter Volume

    Science.gov (United States)

    Jagannathan, Kanchana; Hager, Nathan; Childress, Anna Rose; Rao, Hengyi; Franklin, Teresa R.

    2015-01-01

    Background: Structural magnetic resonance imaging techniques are powerful tools for examining the effects of drug use on the brain. The nicotine and cannabis literature has demonstrated differences between nicotine cigarette smokers and cannabis users compared to controls in brain structure; however, less is known about the effects of co-occurring cannabis and tobacco use. Methods: We used voxel-based morphometry to examine gray matter volume differences between four groups: (1) cannabis-dependent individuals who do not smoke tobacco (Cs); (2) cannabis-dependent individuals who smoke tobacco (CTs); (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (Ts); and (4) healthy controls (HCs). We also explored associations between gray matter volume and measures of cannabis and tobacco use. Results: A significant group effect was observed in the left putamen, thalamus, right precentral gyrus, and left cerebellum. Compared to HCs, the Cs, CTs, and Ts exhibited larger gray matter volumes in the left putamen. Cs also had larger gray matter volume than HCs in the right precentral gyrus. Cs and CTs exhibited smaller gray matter volume than HCs in the thalamus, and CTs and Ts had smaller left cerebellar gray matter volume than HCs. Conclusions: This study extends previous research that independently examined the effects of cannabis or tobacco use on brain structure by including an examination of co-occurring cannabis and tobacco use, and provides evidence that cannabis and tobacco exposure are associated with alterations in brain regions associated with addiction. PMID:26045474

  18. Occurence and implications of radiation dose-rate effects for material aging studies

    Science.gov (United States)

    Gillen, Kenneth T.; Clough, Roger L.

    A number of commercial cable materials, including ethylene propylene rubber and crosslinked polyolefin insulations and chloroprene and chlorosulfonated polyethylene jackets have been radiation aged in air and nitrogen at radiation dose rates ranging from approximately 10 3 to 10 6{rad}/{hr}. Material degradation was followed using ultimate tensile properties (elongation and tensile strength), swelling measurements and infrared spectroscopy. The tensile results indicate that in air environments radiation dose rate effects are important for all four materials, with more mechanical damage occurring as the dose rate is lowered. These results are interpreted as coming from a competition between crosslinking and oxidative scission in which scission becomes more important as the dose rate is lowered. The swelling results offer direct evidence in support of this interpretation. In addition the infrared results show increased carbonyl content at lower dose rates, also indicative of increased oxidation. The conclusions of this study have important implications for the qualification of elastomeric materials for nuclear applications, since they clearly indicate that the mechanism of degradation is quite different (and the amount usually more severe) under low dose rate exposures compared to the mechanism occurring under the high dose rate exposures normally utilized for stimulating the natural aging.

  19. A preliminary retrospective survey of injuries occurring in dogs participating in canine agility.

    Science.gov (United States)

    Levy, M; Hall, C; Trentacosta, N; Percival, M

    2009-01-01

    Little is known about the risks of injury to dogs participating in the relatively new sport of canine agility. The purpose of this study was to identify the factors that put the participating dog at risk as well as determine the anatomical sites that were most commonly injured. A retrospective survey using a paper and web-based data collection instrument was used to evaluate dogs participating in the sport of canine agility. Of the 1627 dogs included in the study, 33% were injured, and of those 58% were injured in competition. Most injuries occurred on dry outdoor surfaces. Border Collies were the most commonly injured, and injuries were in excess of what would be expected from their exposure. For all dogs, soft tissue injuries were most common. The shoulders and backs of dogs were most commonly injured. Dogs were most commonly injured by contact with an obstacle. The A-frame, dogwalk and bar jump obstacles were responsible for nearly two-thirds of injuries that resulted from contact with the obstacle. Border Collies are at higher risk for injury than would be expected from their exposure. The A-frame, dogwalk and bar jump obstacles put the shoulders and backs of dogs at risk. For the first time, this study gives us insight into injuries occurring in dogs participating in canine agility. This will help direct prospective studies that evaluate the safety of individual obstacles, direct rule changes and enable practitioners to understand the risks of the sport.

  20. Auditory stimulus timing influences perceived duration of co-occurring visual stimuli

    Directory of Open Access Journals (Sweden)

    Vincenzo eRomei

    2011-09-01

    Full Text Available There is increasing interest in multisensory influences upon sensory-specific judgements, such as when auditory stimuli affect visual perception. Here we studied whether the duration of an auditory event can objectively affect the perceived duration of a co-occurring visual event. On each trial, participants were presented with a pair of successive flashes and had to judge whether the first or second was longer. Two beeps were presented with the flashes. The order of short and long stimuli could be the same across audition and vision (audiovisual congruent or reversed, so that the longer flash was accompanied by the shorter beep and vice versa (audiovisual incongruent; or the two beeps could have the same duration as each other. Beeps and flashes could onset synchronously or asynchronously. In a further control experiment, the beep durations were much longer (tripled than the flashes. Results showed that visual duration-discrimination sensitivity (d' was significantly higher for congruent (and significantly lower for incongruent audiovisual synchronous combinations, relative to the visual only presentation. This effect was abolished when auditory and visual stimuli were presented asynchronously, or when sound durations tripled those of flashes. We conclude that the temporal properties of co-occurring auditory stimuli influence the perceived duration of visual stimuli and that this can reflect genuine changes in visual sensitivity rather than mere response bias.