bluuebunny/crossref_metadata_2025 huggingface dataset:
Using the Self-Select Paradigm to Delineate the Nature of Speech Motor Programming
Authors: Wright David L. , Robin Don A. , Rhee Jooyhun , Vaculin Amber , Jacks Adam , Guenther Frank H. , Fox Peter T.
Published: May 2009

Purpose

The authors examined the involvement of 2 speech motor programming processes identified by S. T. Klapp (1995, 2003) during the articulation of utterances differing in syllable and sequence complexity. According to S. T. Klapp, 1 process, INT, resolves the demands of the programmed unit, whereas a second process, SEQ, oversees the serial order demands of longer sequences.

Method

A modified reaction time paradigm was used to assess INT and SEQ demands. Specifically, syllable complexity was dependent on syllable structure, whereas sequence complexity involved either repeated or unique syllabi within an utterance.

Results

INT execution was slowed when articulating single syllables in the form CCCV compared to simpler CV syllables. Planning unique syllables within a multisyllabic utterance rather than repetitions of the same syllable slowed INT but not SEQ.

Conclusions

The INT speech motor programming process, important for mental syllabary access, is sensitive to changes in both syllable structure and the number of unique syllables in an utterance.
Electric field effect on the emission rate of H4F and H4S hole traps in InP
Authors: Darwich R. , Alek B.
Published: May 2009

The electric field effect on the emission rate enhancement of the H4F and H4S hole trap in highly Zn-doped InP has been examined using the deep level transient spectroscopy (DLTS) and double correlation DLTS (DDLTS). The DLTS and DDLTS results have been found to be in good agreement for low and intermediate electric fields, but they disagree for large field effect. Comparing our emission data with the theory, we have found that H4F obeys the quantum model of phonon-assisted tunneling, while H4S follows the Poole–Frenkel model employing a three-dimensional screening Coulombic potential. Our results show that the H4S defect can be attributed to a charged (Vp–Zn) complex.
Fracture mechanism of some brittle metallic glasses
Authors: Zhao J. X. , Qu R. T. , Wu F. F. , Zhang Z. F. , Shen B. L. , Stoica M. , Eckert J.
Published: May 2009

A systematic study on the fracture surface of brittle Mg-, Fe-, and Co-based metallic glasses under compressive loading is approached and a fracture mechanism is proposed. Experimentally, the metallic glass samples are compressed into many small fragments, displaying an explosion fracture feature. Therefore, an energy equilibrium model is employed to describe the fracture processes of those brittle metallic glasses. Furthermore, some regular nanoscale steps, which were scarcely discovered, are found on the mirror region on their fracture surfaces. It is suggested that such nanoscale steps are associated with the energy distribution in metallic glasses and are created by the shear waves generated by the instability of crack propagation during the explosion rupture processes. Based on the comparison of experimental observations with numerical calculations, we recommend a novel model for interpreting the development of nanoscale steps on the dynamic fracture surfaces of these brittle metallic glasses, which appropriately describes the experimental findings.
A correlation between transport current density and grain connectivity in MgB2/Fe wire made from ball-milled boron
Authors: Xu X. , Kim J. H. , Dou S. X. , Choi S. , Lee J. H. , Park H. W. , Rindfleish M. , Tomsic M.
Published: May 2009

Studies of the magnetic field dependence of the transport critical current density (Jct) and the grain connectivity of MgB2/Fe wires fabricated from ball-milled boron have been conducted in detail, and strong correlations have been found, as evidenced by differences in grain size, critical transition temperature, and resistivity. It was observed that the samples fabricated by ball milling had relatively small grain sizes, resulting in a strong field dependence of the Jct in the high field region. On the other hand, the ball-milled boron was associated with poor connectivity between adjacent grains. It is clearly shown that the observed reduction in low field Jct is related to the reduction in the superconducting area fraction (AF) that is reflected by the connectivity factor. Even if high temperature sintering in all the samples can compensate for the degradation of the Jct in the low field region, the subsequent grain growth is mainly responsible for the degradation of Jct in the high field region.
Energy transfer between Yb3+ and Er3+ in barium gallogermanate glass
Authors: Jiang X. P. , Yang Z. M. , Liu T. , Xu S. H.
Published: May 2009

Spectroscopic properties of Er3+/Yb3+ codoped barium gallogermanate glass demonstrate that an efficient energy transfer from Yb3+ to Er3+ ions occurs while the back energy transfer from Er3+ to Yb3+ ions cannot be ignored. Based on the rate equations of electron transitions, the forward energy transfer Yb3+(F25/2)+Er3+(I415/2)→Yb3+(F27/2)+Er3+(I411/2) and the back transfer Er3+(I411/2)+Yb3+(F27/2)→Er3+(I415/2)+Yb3+(F25/2) coefficients were calculated to be 9.2×10−17 cm3 s−1 and 1.1×10−17 cm3 s−1, respectively. Also the energy transfer upconversion coefficient Yb3+(F25/2)+Er3+(I411/2)→Yb3+(F27/2)+Er3+(F27/2) was determined to be 1.1×10−16 cm3 s−1. The calculated results show that a population inversion between the I413/2 and I415/2 levels can be attained at a low pumping flux of around 1.7×1022 cm−2 s−1, while the inversion threshold between the S43/2 and I415/2 levels is about 30 times higher when pumped by 980 nm laser diode. With increasing pump flux the back energy transfer probability becomes larger and when the pump flux is more than 2.0×1022 cm−2 s−1, the back energy transfer probability dominates the forward energy transfer probability.
Dynamical deformations of three-dimensional Lie algebras in Bianchi classification over the harmonic oscillator
Authors: Paal Eugen , Virkepu Jüri
Published: May 2009

Operadic Lax representations for the harmonic oscillator are used to construct the dynamical deformations of three-dimensional (3D) real Lie algebras in the Bianchi classification. It is shown that the energy conservation of the harmonic oscillator is related to the Jacobi identities of the dynamically deformed algebras. Based on this observation, it is proved that the dynamical deformations of 3D real Lie algebras in the Bianchi classification over the harmonic oscillator are Lie algebras.
Electrophoretic coating of carbon nanotubes for high energy-density capacitor applications
Authors: Bakhoum Ezzat G. , Cheng Marvin H. M.
Published: May 2009

This paper reports the successful coating of carbon nanotubes (CNTs) grown on a metallic surface with particles of a ceramic dielectric material by using the electrophoretic deposition technique. Electrophoretic deposition, which is performed at room temperature, has achieved results that are far superior to chemical vapor deposition in this particular application. In an anticipated new breed of capacitors known as the “three-dimensional capacitors,” conventional metallic electrodes will be replaced by CNTs for substantially larger electrode areas. The development of such capacitors is awaiting a technique for successfully coating CNTs with high dielectric-constant ceramics. Such a development is reported here.

At the request of the authors, this article is being retracted effective 17 May 2022.
Raman spectroscopic study of cyclopentane at high pressure
Authors: Tkachev Sergey N. , Pravica Michael , Kim Eunja , Weck Philippe F.
Published: May 2009

The behavior of cyclopentane with pressure has been investigated to 21.5 GPa using Raman spectroscopy. Various phases were observed with pressure which included liquid, two plastic, and one true crystalline phases of cyclopentane during compression and decompression sequences. Optimized molecular structure and Raman and IR vibrational spectra of the most stable puckered-ring conformation of the cyclopentane molecule were also computed using density functional theory methods. The theoretically calculated values as well as the experimentally determined pressure dependencies of spectral bands are in very good agreement with the low temperature measurements and previous mode assignments. The phase diagram of cyclopentane was analyzed with respect to pressure-induced alterations in Raman spectra across the phase boundaries. The various forms of “frozen-in” conformations in phase III are suggested to explain previous results related to existence of a “new” phase between plastic crystalline phase II and monoclinic phase III in solid cyclopentane.
Dependence of elastic depolarization cross sections on the potential: OH(X Π2)-Ar and NO(X Π2)-Ar
Authors: Dagdigian Paul J. , Alexander Millard H.
Published: May 2009

Elastic tensor and depolarization cross sections are computed for the collision of two exemplary diatomic molecules with Π2 electronic ground states—OH and NO—with argon. The interaction of a diatomic molecule in a Π state with a spherical collision partner must be described by two potential energy surfaces (PESs), corresponding to the two asymptotically degenerate electronic states, of A′ and A″ symmetry. Quantum scattering calculations are most naturally based on the average (Vsum) and half-difference (Vdif) of these two PESs. When Vdif is neglected, the OH(X Π2)-Ar depolarization cross sections are found to be significantly reduced in magnitude, while the NO(X Π2)-Ar cross sections are relatively unaffected. In addition, treating the molecules as closed-shell Σ1+ species with a corresponding rotational level structure and using (Vsum) to model the PES, we predict depolarization cross sections which differ significantly from those based on full inclusion of the electronic degeneracy and fine structure of these Π2 molecules. This indicates that any single-PES-based simulation of the collisional depolarization of these two molecules would be subject to significant error.
Do all wurtzite nanotubes prefer faceted ones?
Authors: Li Yafei , Zhou Zhen , Chen Yongsheng , Chen Zhongfang
Published: May 2009

First-principles computations have been preformed to investigate the stability of one-dimensional (1D) crystalline nanowires, faceted nanotubes, and conventional single-walled nanotubes (SWNTs) with various sizes, as well as the two-dimensional infinitely single layers for several wurtzite materials. Regardless of the diameters, the SWNTs are more stable than sp3-dominated faceted nanotubes and nanowires for BN and C, while for AlN, GaN, ZnO, ZnS, and Si, the faceted nanotubes and nanowires are always more preferred energetically than SWNTs. However, the stability of SiC SWNTs relative to other 1D nanostructures is diameter-dependent: the SiC SWNTs are more stable than thinner faceted nanotubes and nanowires, but less stable than thick ones. This indicates that SiC SWNTs and faceted nanotubes/nanowires preserving wurtzite configuration can coexist in nanoscale. The different stabilities for various nanostructures are attributed to the competition between sp2 and sp3 hybridization of the atoms in wurtzite materials associated with the difference in the atomic radius and electronegativity of the elements involved.
Room-temperature ferromagnetism in dielectric GaN(Gd)
Authors: Litvinov V. I. , Dugaev V. K.
Published: May 2009

We present an explanation of recently observed giant magnetic moment and room-temperature ferromagnetism in the dielectric GaN doped with Gd. Our approach uses the polarization mechanism of exchange interaction, which occurs if the d-level of Gd appears in the bandgap close to the valence band edge. Calculated ferromagnetic critical temperature and the value of the magnetic moment well correspond to experimental findings.
Evolutionary selection between alternative modes of gene regulation
Authors: Gerland Ulrich , Hwa Terence
Published: May 2009

Microorganisms employ a wealth of gene regulatory mechanisms to adjust their growth programs to variations in the environment. It was pointed out long ago [Savageau M (1977)
Proc Natl Acad Sci USA
74
: 5647–5651] that the particular mode of gene regulation employed may be correlated with the “demand” on the regulated gene, i.e., how frequently the gene product is needed in its natural habitat. An evolutionary “use-it-or-lose-it” principle was proposed to govern the choice of gene regulatory strategies. Here, we examine quantitatively the forces selecting for and against two opposing modes of gene regulation, in the context of an evolutionary model that takes genetic drift, mutation, and time-dependent selection into account. We consider the effect of time-dependent selection, with periods of strong selection alternating with periods of neutral evolution. Using a variety of analytical methods, we find the effective population size and the typical time scale of environmental variations to be key parameters determining the fitness advantage of the different modes of regulation. Our results support Savageau's use-it-or-lose-it principle for small populations with long time scales of environmental variations and support a complementary “wear-and-tear” principle for the opposite situation.
Simultaneous inactivation of Par-4 and PTEN in vivo leads to synergistic NF-κB activation and invasive prostate carcinoma
Authors: Fernandez-Marcos Pablo J. , Abu-Baker Shadi , Joshi Jayashree , Galvez Anita , Castilla Elias A. , Cañamero Marta , Collado Manuel , Saez Carmen , Moreno-Bueno Gema , Palacios Jose , Leitges Michael , Serrano Manuel , Moscat Jorge , Diaz-Meco Maria T.
Published: May 2009

Prostate cancer is one of the most common neoplasias in men. The tumor suppressor Par-4 is an important negative regulator of the canonical NF-κB pathway and is highly expressed in prostate. Here we show that Par-4 expression is lost in a high percentage of human prostate carcinomas, and this occurs in association with phosphatase and tensin homolog deleted from chromosome 10 (PTEN) loss. Par-4 null mice, similar to PTEN-heterozygous mice, only develop benign prostate lesions, but, importantly, concomitant Par-4 ablation and PTEN-heterozygosity lead to invasive prostate carcinoma in mice. This strong tumorigenic cooperation is anticipated in the preneoplastic prostate epithelium by an additive increase in Akt activation and a synergistic stimulation of NF-κB. These results establish the cooperation between Par-4 and PTEN as relevant for the development of prostate cancer and implicate the NF-κB pathway as a critical event in prostate tumorigenesis.
Hydrogen bond dynamics in the active site of photoactive yellow protein
Authors: Sigala Paul A. , Tsuchida Mark A. , Herschlag Daniel
Published: May 2009

Hydrogen bonds play major roles in biological structure and function. Nonetheless, hydrogen-bonded protons are not typically observed by X-ray crystallography, and most structural studies provide limited insight into the conformational plasticity of individual hydrogen bonds or the dynamical coupling present within hydrogen bond networks. We report the NMR detection of the hydrogen-bonded protons donated by Tyr-42 and Glu-46 to the chromophore oxygen in the active site of the bacterial photoreceptor, photoactive yellow protein (PYP). We have used the NMR resonances for these hydrogen bonds to probe their conformational properties and ability to rearrange in response to nearby electronic perturbation. The detection of geometric isotope effects transmitted between the Tyr-42 and Glu-46 hydrogen bonds provides strong evidence for robust coupling of their equilibrium conformations. Incorporation of a modified chromophore containing an electron-withdrawing cyano group to delocalize negative charge from the chromophore oxygen, analogous to the electronic rearrangement detected upon photon absorption, results in a lengthening of the Tyr-42 and Glu-46 hydrogen bonds and an attenuated hydrogen bond coupling. The results herein elucidate fundamental properties of hydrogen bonds within the complex environment of a protein interior. Furthermore, the robust conformational coupling and plasticity of hydrogen bonds observed in the PYP active site may facilitate the larger-scale dynamical coupling and signal transduction inherent to the biological function that PYP has evolved to carry out and may provide a model for other coupled dynamic systems.
Mirroring of attention by neurons in macaque parietal cortex
Authors: Shepherd Stephen V. , Klein Jeffrey T. , Deaner Robert O. , Platt Michael L.
Published: May 2009

Macaques, like humans, rapidly orient their attention in the direction other individuals are looking. Both cortical and subcortical pathways have been proposed as neural mediators of social gaze following, but neither pathway has been characterized electrophysiologically in behaving animals. To address this gap, we recorded the activity of single neurons in the lateral intraparietal area (LIP) of rhesus macaques to determine whether and how this area might contribute to gaze following. A subset of LIP neurons mirrored observed attention by firing both when the subject looked in the preferred direction of the neuron, and when observed monkeys looked in the preferred direction of the neuron, despite the irrelevance of the monkey images to the task. Importantly, the timing of these modulations matched the time course of gaze-following behavior. A second population of neurons was suppressed by social gaze cues, possibly subserving task demands by maintaining fixation on the observed face. These observations suggest that LIP contributes to sharing of observed attention and link mirror representations in parietal cortex to a well studied imitative behavior.
The chemodiversity of wines can reveal a metabologeography expression of cooperage oak wood
Authors: Gougeon Régis D. , Lucio Marianna , Frommberger Moritz , Peyron Dominique , Chassagne David , Alexandre Hervé , Feuillat François , Voilley Andrée , Cayot Philippe , Gebefügi Istvan , Hertkorn Norbert , Schmitt-Kopplin Philippe
Published: May 2009

Wine chemical compositions, which result from a complex interplay between environmental factors, genetic factors, and viticultural practices, have mostly been studied using targeted analyses of selected families of metabolites. Detailed studies have particularly concerned volatile and polyphenolic compounds because of their acknowledged roles in the organoleptic and therapeutic properties. However, we show that an unprecedented chemical diversity of wine composition can be unraveled through a nontargeted approach by ultrahigh-resolution mass spectrometry, which provides an instantaneous image of complex interacting processes, not easily or possibly resolvable into their unambiguous individual contributions. In particular, the statistical analysis of a series of barrel-aged wines revealed that 10-year-old wines still express a metabologeographic signature of the forest location where oaks of the barrel in which they were aged have grown.
Structure of toroidal DNA collapsed inside the phage capsid
Authors: Leforestier Amélie , Livolant Françoise
Published: May 2009

The structure of DNA toroids made of individual DNA molecules of various lengths (3,000 to 55,000 bp) was studied, by using partially filled bacteriophage capsids in conjunction with cryoelectron microscopy. The tetravalent cation spermine was diffused through the capsid to condense the DNA under conditions that were chosen to produce a hexagonal packing. Our results demonstrate that the frustration arising between chirality and hexagonal packing leads to the formation of twist walls; the correlation between helices combined with their strong curvature impose variations of the DNA helical pitch.
Essential role for a long-term depression mechanism in ocular dominance plasticity
Authors: Yoon Bong-June , Smith Gordon B. , Heynen Arnold J. , Neve Rachael L. , Bear Mark F.
Published: May 2009

The classic example of experience-dependent cortical plasticity is the ocular dominance (OD) shift in visual cortex after monocular deprivation (MD). The experimental model of homosynaptic long-term depression (LTD) was originally introduced to study the mechanisms that could account for deprivation-induced loss of visual responsiveness. One established LTD mechanism is a loss of sensitivity to the neurotransmitter glutamate caused by internalization of postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs). Although it has been shown that MD similarly causes a loss of AMPARs from visual cortical synapses, the contribution of this change to the OD shift has not been established. Using an herpes simplex virus (HSV) vector, we expressed in visual cortical neurons a peptide (G2CT) designed to block AMPAR internalization by hindering the association of the C-terminal tail of the AMPAR GluR2 subunit with the AP2 clathrin adaptor complex. We found that G2CT expression interferes with NMDA receptor (NMDAR)-dependent AMPAR endocytosis and LTD, without affecting baseline synaptic transmission. When expressed in vivo, G2CT completely blocked the OD shift and depression of deprived-eye responses after MD without affecting baseline visual responsiveness or experience-dependent response potentiation in layer 4 of visual cortex. These data suggest that AMPAR internalization is essential for the loss of synaptic strength caused by sensory deprivation in visual cortex.
Bam and Bgcn antagonize
Nanos
-dependent germ-line stem cell maintenance
Authors: Li Yun , Minor Nicole T. , Park Joseph K. , McKearin Dennis M. , Maines Jean Z.
Published: May 2009

The balance between germ-line stem cell (GSC) self-renewal and differentiation in
Drosophila
ovaries is mediated by the antagonistic relationship between the Nanos (Nos)-Pumilio translational repressor complex, which promotes GSC self-renewal, and expression of Bam, a key differentiation factor. Here, we find that Bam and Nos proteins are expressed in reciprocal patterns in young germ cells. Repression of Nos in Bam-expressing cells depends on sequences in the
nos
3′-UTR, suggesting that Nos is regulated by translational repression. Ectopic Bam causes differentiation of GSCs, and this activity depends on the endogenous
nos
3′-UTR sequence. Previous evidence showed that Bgcn is an obligate factor for the ability of Bam to drive differentiation, and we now report that Bam forms a complex with Bgcn, a protein related to the RNA-interacting DExH-box polypeptides. Together, these observations suggest that Bam-Bgcn act together to antagonize Nos expression; thus, derepressing cystoblast-promoting factors. These findings emphasize the importance of translational repression in balancing stem cell self-renewal and differentiation.
Infochemistry and infofuses for the chemical storage and transmission of coded information
Authors: Thomas Samuel W. , Chiechi Ryan C. , LaFratta Christopher N. , Webb Michael R. , Lee Andrew , Wiley Benjamin J. , Zakin Mitchell R. , Walt David R. , Whitesides George M.
Published: May 2009

This article describes a self-powered system that uses chemical reactions—the thermal excitation of alkali metals—to transmit coded alphanumeric information. The transmitter (an “infofuse”) is a strip of the flammable polymer nitrocellulose patterned with alkali metal ions; this pattern encodes the information. The wavelengths of 2 consecutive pulses of light represent each alphanumeric character. While burning, infofuses transmit a sequence of pulses (at 5–20 Hz) of atomic emission that correspond to the sequence of metallic salts (and therefore to the encoded information). This system combines information technology and chemical reactions into a new area—“infochemistry”—that is the first step toward systems that combine sensing and transduction of chemical signals with multicolor transmission of alphanumeric information.
Single-nucleotide polymorphisms in the p53 pathway regulate fertility in humans
Authors: Kang Hey-Joo , Feng Zhaohui , Sun Yvonne , Atwal Gurinder , Murphy Maureen E. , Rebbeck Timothy R. , Rosenwaks Zev , Levine Arnold J. , Hu Wenwei
Published: May 2009

The tumor suppressor protein p53 plays an important role in maternal reproduction in mice through transcriptional regulation of leukemia inhibitory factor (LIF), a cytokine crucial for blastocyst implantation. To determine whether these observations could be extended to humans, a list of single-nucleotide polymorphisms (SNPs) in the p53 pathway that can modify the function of p53 was assembled and used to study their impact on human fertility. The p53 allele encoding proline at codon 72 (P72) was found to be significantly enriched over the allele encoding arginine (R72) among in vitro fertilization (IVF) patients. The P72 allele serves as a risk factor for implantation failure. LIF levels are significantly lower in cells with the P72 allele than in cells with the R72 allele, which may contribute to the decreased implantation and fertility associated with the P72 allele. Selected alleles in SNPs in LIF, Mdm2, Mdm4, and Hausp genes, each of which regulates p53 levels in cells, are also enriched in IVF patients. Interestingly, the role of these SNPs on fertility was much reduced or absent in patients older than 35 years of age, indicating that other functions may play a more important role in infertility in older women. The association of SNPs in the p53 pathway with human fertility suggests that p53 regulates the efficiency of human reproduction. These results also provide a plausible explanation for the evolutionary positive selection of some alleles in the p53 pathway and demonstrate the alleles in the p53 pathway as a good example of antagonistic pleiotropy.
Kinetic modelling of impurity transport in detached plasma for integrated divertor simulation with SONIC (SOLDOR/NEUT2D/IMPMC/EDDY)
Authors: Shimizu K. , Takizuka T. , Ohya K. , Inai K. , Nakano T. , Takayama A. , Kawashima H. , Hoshino K.
Published: May 2009

A Monte Carlo (MC) impurity code IMPMC has been coupled self-consistently with a divertor code SOLDOR/NEUT2D by overcoming the intrinsic problems of MC modelling for impurity transport. MC modelling is required for impurity transport in order to take into account the kinetic effect and the complex dissociation processes of hydrocarbons. The integrated divertor code SONIC enables us to investigate the details of impurity transport including erosion/redeposition processes on the divertor plates by further coupling of an 3D plasma–surface interaction MC code EDDY. The dynamic evolution of X-point MARFE observed in JT-60U is investigated. The simulation results indicate that the hydrocarbons sputtered from the dome contribute to the enhanced radiation near the X-point. The kinetic effect of thermal force on the He transport is investigated for JT-60SA detached plasmas. Without the recycling, the kinetic effect improves the helium compression, compared with the conventional (fluid) evaluation. This effect is, however, masked by the recycling at the divertor targets.
Study of ion turbulent transport and profile formations using global gyrokinetic full-f Vlasov simulation
Authors: Idomura Y. , Urano H. , Aiba N. , Tokuda S.
Published: May 2009

A global gyrokinetic toroidal full-f five-dimensional Vlasov simulation GT5D (Idomura et al 2008 Comput. Phys. Commun.
179 391)is extended including sources and collisions. Long time tokamak micro-turbulence simulations in open system tokamak plasmas are enabled for the first time based on a full-f gyrokinetic approach with self-consistent evolutions of turbulent transport and equilibrium profiles. The neoclassical physics is implemented using the linear Fokker–Planck collision operator, and the equilibrium radial electric field E
r is determined self-consistently by evolving equilibrium profiles. In ion temperature gradient driven turbulence simulations in a normal shear tokamak with on-axis heating, key features of ion turbulent transport are clarified. It is found that stiff ion temperature T
i profiles are sustained with globally constant L
ti ≡ |T
i/T
i′| near a critical value, and a significant part of the heat flux is carried by avalanches with 1/f type spectra, which suggest a self-organized criticality. The E

r
shear strongly affects the directions of avalanche propagation and the momentum flux. Non-diffusive momentum transport due to the E
r shear stress is observed and a non-zero (intrinsic) toroidal rotation is formed without momentum input near the axis.
Symmetry breaking effects of toroidicity on toroidal momentum transport
Authors: Weiland J. , Singh R. , Nordman H. , Kaw P. , Peeters A.G. , Strinzi D.
Published: May 2009

A derivation of symmetry breaking toroidicity effects on toroidal momentum transport has been made from the stress tensor. This effect is usually stronger than the symmetry breaking caused by the flowshear on the eigenfunction. The model obtained generalizes a recent derivation of diagonal transport elements from the stress tensor to convective elements of turbulent equipartition or thermoelectric types. This makes it possible to interpret the same type of effects previously obtained from a phase space conserving nonlinear gyrokinetic equation.
Observations of suppressed retention and blistering for tungsten exposed to deuterium–helium mixture plasmas
Authors: Miyamoto M. , Nishijima D. , Ueda Y. , Doerner R.P. , Kurishita H. , Baldwin M.J. , Morito S. , Ono K. , Hanna J.
Published: May 2009

Blister formation and D retention in W have been investigated for low energy (∼55 ± 15 eV), high flux (∼1022 m−2 s−1), high fluence (⩽4.5 × 1026 m−2) ion bombardment at moderate temperature (∼573 K) in mixed species D+He plasmas in the linear divertor plasma simulator PISCES-A. The amount of D retained in W is found to decrease significantly when compared with that in W exposed to pure D plasmas, as measured with high resolution thermal desorption spectroscopy. Scanning electron microscopy observations reveal the suppression of the blisters, a surface feature known to drive up retention, in the D + He mixture plasma exposed W samples. Reduced D retention is accompanied by the formation of nano-sized high density He bubbles in the near surface, observed with a transmission electron microscope (TEM). It is believed that the nano-bubbles act as a diffusion barrier to implanted D atoms and consequently reduce the amount of uptake in the W material. This newly observed effect implies that current predictions of D retention in W, in actual fusion devices, may be overestimated, since there will be He ash in fusion plasma. Toughness enhanced, fine-grained (grain size of ∼1 µm) W–TiC samples, exposed to pure D plasma conditions, also show little or no evidence of blistering. The measured D retention in the W–TiC samples was approximately 1 × 1019 D m−2 corresponding to about 2 × 10−7 of the implanted D fluence, and is very low compared with the retention in pure stress relieved W, which exhibited surface blisters and had a D retention of about 1 × 1021 D m−2.
Changes in Attitudes of Japanese Doctors toward Complementary and Alternative Medicine—Comparison of Surveys in 1999 and 2005 in Kyoto
Authors: Fujiwara Kenji , Imanishi Jiro , Watanabe Satoko , Ozasa Kotaro , Sakurada Kumi
Published: May 2009

We surveyed the attitudes of Japanese medical doctors toward complementary and alternative medicine (CAM) in 1999. It is supposed that the situation concerning CAM has been changing recently. The aim of the present study is to survey the attitude of doctors toward CAM again, and to examine changes in attitude over the last 6 years. The attitudes of medical doctors belonging to the Kyoto Medical Association toward CAM were surveyed by a structured, self‐administered questionnaire in 1999 and 2005. The results showed that the doctors familiar with the term “CAM”, practicing CAM therapies, and attending meetings or training courses related with CAM, increased significantly from 1999 to 2005. The doctors who possessed knowledge of CAM also increased significantly from 1999 to 2005. Almost all doctors believed in the effectiveness of Kampo (Japanese traditional herbal medicine) and acupuncture. The number of doctors who believed in the effectiveness of aromatherapy and ayurveda increased significantly in 2005, compared with 1999. In the near future, 58% of doctors desired to practice CAM therapies. In conclusion, the numbers of doctors who practice CAM therapies, possess CAM knowledge and desire to practice such therapies have increased over the last 6 years in Japan.
AdnAB: a new DSB-resecting motor–nuclease from mycobacteria
Authors: Sinha Krishna Murari , Unciuleac Mihaela-Carmen , Glickman Michael S. , Shuman Stewart
Published: May 2009

The resection of DNA double-strand breaks (DSBs) in bacteria is a motor-driven process performed by a multisubunit helicase–nuclease complex: either an Escherichia coli-type RecBCD enzyme or a Bacillus-type AddAB enzyme. Here we identify mycobacterial AdnAB as the founder of a new family of heterodimeric helicase–nucleases with distinctive properties. The AdnA and AdnB subunits are each composed of an N-terminal UvrD-like motor domain and a C-terminal nuclease module. The AdnAB ATPase is triggered by dsDNA with free ends and the energy of ATP hydrolysis is coupled to DSB end resection by the AdnAB nuclease. The mycobacterial nonhomologous end-joining (NHEJ) protein Ku protects DSBs from resection by AdnAB. We find that AdnAB incises ssDNA by measuring the distance from the free 5′ end to dictate the sites of cleavage, which are predominantly 5 or 6 nucleotides (nt) from the 5′ end. The “molecular ruler” of AdnAB is regulated by ATP, which elicits an increase in ssDNA cleavage rate and a distal displacement of the cleavage sites 16–17 nt from the 5′ terminus. AdnAB is a dual nuclease with a clear division of labor between the subunits. Mutations in the nuclease active site of the AdnB subunit ablate the ATP-inducible cleavages; the corresponding changes in AdnA abolish ATP-independent cleavage. Complete suppression of DSB end resection requires simultaneous mutation of both subunit nucleases. The nuclease-null AdnAB is a helicase that unwinds linear plasmid DNA without degrading the displaced single strands. Mutations of the phosphohydrolase active site of the AdnB subunit ablate DNA-dependent ATPase activity, DSB end resection, and ATP-inducible ssDNA cleavage; the equivalent mutations of the AdnA subunit have comparatively little effect. AdnAB is a novel signature of the Actinomycetales taxon. Mycobacteria are exceptional in that they encode both AdnAB and RecBCD, suggesting the existence of alternative end-resecting motor–nuclease complexes.
Automated identification of conserved synteny after whole-genome duplication
Authors: Catchen Julian M. , Conery John S. , Postlethwait John H.
Published: May 2009

An important objective for inferring the evolutionary history of gene families is the determination of orthologies and paralogies. Lineage-specific paralog loss following whole-genome duplication events can cause anciently related homologs to appear in some assays as orthologs. Conserved synteny—the tendency of neighboring genes to retain their relative positions and orders on chromosomes over evolutionary time—can help resolve such errors. Several previous studies examined genome-wide syntenic conservation to infer the contents of ancestral chromosomes and provided insights into the architecture of ancestral genomes, but did not provide methods or tools applicable to the study of the evolution of individual gene families. We developed an automated system to identify conserved syntenic regions in a primary genome using as outgroup a genome that diverged from the investigated lineage before a whole-genome duplication event. The product of this automated analysis, the Synteny Database, allows a user to examine fully or partially assembled genomes. The Synteny Database is optimized for the investigation of individual gene families in multiple lineages and can detect chromosomal inversions and translocations as well as ohnologs (paralogs derived by whole-genome duplication) gone missing. To demonstrate the utility of the system, we present a case study of gene family evolution, investigating the ARNTL gene family in the genomes of Ciona intestinalis, amphioxus, zebrafish, and human.
DWARF27, an Iron-Containing Protein Required for the Biosynthesis of Strigolactones, Regulates Rice Tiller Bud Outgrowth
Authors: Lin Hao , Wang Renxiao , Qian Qian , Yan Meixian , Meng Xiangbing , Fu Zhiming , Yan Cunyu , Jiang Biao , Su Zhen , Li Jiayang , Wang Yonghong
Published: May 2009

Tillering in rice (Oryza sativa) is one of the most important agronomic traits that determine grain yields. Previous studies on rice tillering mutants have shown that the outgrowth of tiller buds in rice is regulated by a carotenoid-derived MAX/RMS/D (more axillary branching) pathway, which may be conserved in higher plants. Strigolactones, a group of terpenoid lactones, have been recently identified as products of the MAX/RMS/D pathway that inhibits axillary bud outgrowth. We report here the molecular genetic characterization of d27, a classic rice mutant exhibiting increased tillers and reduced plant height. D27 encodes a novel iron-containing protein that localizes in chloroplasts and is expressed mainly in vascular cells of shoots and roots. The phenotype of d27 is correlated with enhanced polar auxin transport. The phenotypes of the d27 d10 double mutant are similar to those of d10, a mutant defective in the ortholog of MAX4/RMS1 in rice. In addition, 2′-epi-5-deoxystrigol, an identified strigolactone in root exudates of rice seedlings, was undetectable in d27, and the phenotypes of d27 could be rescued by supplementation with GR24, a synthetic strigolactone analog. Our results demonstrate that D27 is involved in the MAX/RMS/D pathway, in which D27 acts as a new member participating in the biosynthesis of strigolactones.
Calcium Spiking Patterns and the Role of the Calcium/Calmodulin-Dependent Kinase CCaMK in Lateral Root Base Nodulation of Sesbania rostrata
Authors: Capoen Ward , Den Herder Jeroen , Sun Jongho , Verplancke Christa , De Keyser Annick , De Rycke Riet , Goormachtig Sofie , Oldroyd Giles , Holsters Marcelle
Published: May 2009

Nodulation factor (NF) signal transduction in the legume-rhizobium symbiosis involves calcium oscillations that are instrumental in eliciting nodulation. To date, Ca2+ spiking has been studied exclusively in the intracellular bacterial invasion of growing root hairs in zone I. This mechanism is not the only one by which rhizobia gain entry into their hosts; the tropical legume Sesbania rostrata can be invaded intercellularly by rhizobia at cracks caused by lateral root emergence, and this process is associated with cell death for formation of infection pockets. We show that epidermal cells at lateral root bases respond to NFs with Ca2+ oscillations that are faster and more symmetrical than those observed during root hair invasion. Enhanced jasmonic acid or reduced ethylene levels slowed down the Ca2+ spiking frequency and stimulated intracellular root hair invasion by rhizobia, but prevented nodule formation. Hence, intracellular invasion in root hairs is linked with a very specific Ca2+ signature. In parallel experiments, we found that knockdown of the calcium/calmodulin-dependent protein kinase gene of S. rostrata abolished nodule development but not the formation of infection pockets by intercellular invasion at lateral root bases, suggesting that the colonization of the outer cortex is independent of Ca2+ spiking decoding.
Dilemmas in information science (IS) and information retrieval (IR)
Authors: Thornley Clare
Published: May 2009

Purpose

The purpose of this paper is to analyse the extent to which understanding information science (IS) and information retrieval (IR) as disciplines characterised by intractable dilemmas is a useful conceptual framework through reviewing and re‐evaluating an important contribution to the field in light of more recent developments.

Design/methodology/approach

This paper reviews the discussion of central dilemmas within IS and IR, through literature review and conceptual analysis. It assesses the extent to which they remain intractable problems or whether improved solutions have been developed and discusses the implications of these ongoing challenges. The main problem addressed is, in Neill's terminology, “the dilemma of the subjective in information organisation and retrieval” which is understood as the problem of how the meaning of documents can be represented to meet the needs of the user.

Findings

Many of the dilemmas discussed within IS and IR remain fairly intractable primarily because information and meaning have both subjective and objective qualities which often have a complex relationship. Recent technological developments have, however, altered the nature of some of these dilemmas and also created some new dilemmas for the subject.

Research implications/limitations

Historical perspectives within IR and IS should be used when discussing theoretical and technological developments in the subject. The conceptual framework of dilemmas remains a useful theoretical tool for IS and IR in terms of examining the nature of problems in research and practice.

Originality/value

This paper re‐visits an important theme in IS and IR and provides an updated perspective on some central issues.
Effect of temperature and thiosulphate on the corrosion behaviour of 90‐10 copper‐nickel alloys in seawater
Authors: Ezuber Hosni M.
Published: May 2009

Purpose

The purpose of this paper is to evaluate the effect of seawater temperature on the corrosion behaviour of 90‐10 cupronickel alloys. Also, to investigate the effect of thiosulphate additions (one of the major sulphide oxidation products in seawater) on the alloy corrosion rate in seawater.

Design/methodology/approach

Potentiodynamic polarization measurement (DC) was used to estimate the corrosion rate of the cupronickel alloy in seawater with and without thiosulphate species (50‐650 ppm).

Findings

It was observed that the cupronickel alloy suffered accelerated corrosion as the seawater temperature was raised from 25 to 50 or 80°C. The increase in the corrosion rate was found to correspond well with the negative shift in the free corrosion potential. Thiosulphate addition was found to depend on the test temperature. At 25°C, thiosulphate activated the alloy dissolution rate and the higher were the thiosulphate concentrations, the higher was the corrosion rate. At 50 or 80°C, however, thiosulphate promoted the dissolution rate at early stages, but seemed to interfere with the surface film formation later on, producing a black film that effectively decreased the alloy corrosion rate. At higher potentials, however, the film became non‐protective, leading to accelerated corrosion once again.

Originality/value

This paper explains the corrosion behaviour of 90‐10 cupronickel alloys in seawater as a function of test temperature and thiosulphate additions.
Reflections on corporate reputations
Authors: Worcester Robert
Published: May 2009

Purpose

The purpose of this paper is to illustrate the importance of corporate reputation to the management of contemporary organisations.

Design/methodology/approach

The approach takes the form of survey research and case studies. The paper is informed by corporate image and reputation research undertaken for major international corporations, governments and NGOs in the UK and in countries throughout the world dating back to the late 1960s.

Findings

The paper finds that corporate image is an important factor in the success or failure of virtually all major organisations; corporate reputation is the synthesis of many factors: the brand(s) image, the products (and/or services) class image(s), the brand user(s) image, the image of the country of perceived ownership of a corporation, and the corporate culture/personality; corporate reputations can be measured, and changes in corporate reputations can be tracked; and corporate responsibility is replacing corporate social responsibility as an increasingly important factor in how people regard the corporate reputation of organisations.

Practical implications

Policy makers should actively research and manage their corporate reputation. Familiarity breeds favourability, not contempt. All too often senior managers and their advisers (brand and corporate consultants, design consultants, advertising and public relations advisers, etc.), who have responsibility for the organisation's corporate reputation, muddle the distinctions between corporate reputation, corporate image, corporate identity, corporate personality, corporate culture, and other ways by which the elements of the corporate reputation are defined, and therefore used and measured.

Originality/value

The paper shares some of the lessons learned from 40 years' experience of MORI. The paper also marshals insights from the published output, lectures, and image‐modelling work.
Assessment of selenium intake levels through typical Pakistani diet
Authors: Akhter Perveen , Rahman M.K.
Published: May 2009

Purpose

Selenium deficiency in combination with iodine also has profound effect in the generation of thyroid related diseases and on neonatal growth and its survival. In Pakistan, occurrence of thyroid related diseases are common. Low levels of iodine in food have been established and published estimates are available, but data on selenium intake levels were scarce. The purpose of this paper is to generate baseline analytical data on dietary intake of selenium to investigate its impact on occurrence of thyroid related diseases in Pakistani population.

Design/methodology/approach

Food samples were collected from major cities/districts of the country using market basket method. Daily diets were prepared and analyzed by using neutron activation analysis.

Findings

Measured levels varied from 51 to 453ng/g with geometric mean value (GM) × geometric standard deviation (GSD) of 163 × 1.6ng/g. This leads to daily intake variation from 31 to 270 μg/d with GM × GSD value of 97 × 1.6 μg/d. The measured levels were compared with reported values of other countries and recommended estimated safe and adequate daily dietary intake (ESADDI) range of 50‐200 μg/d for adults. The estimated selenium levels are adequate and safe as per international standard.

Originality/value

The paper provides baseline data and indicates that Pakistani diet contains sufficient amount of selenium and may not be cause of concern for thyroid related diseases in our country.
The health effects of black tea and flavonoids
Authors: Ruxton Carrie H.S.
Published: May 2009

Purpose

The purpose of this paper is to review evidence on the impact of black tea on health, highlighting the role of flavonoids.

Design/methodology/approach

This review builds on previous systematic reviews by incorporating new studies on black tea and health published between 2004 and 2009.

Findings

Black tea was strongly associated with heart disease prevention by plausible mechanisms linked to flavonoid bioactivity. In vitro studies suggest that tea has anti‐cancer properties, but this needs to be confirmed by additional long‐term human studies. Emerging research indicates that tea may benefit cognitive function and weight management, although more studies are needed. Tea flavonoids are bioavailable with or without milk.

Originality/value

The benefits of tea drinking are of relevance to public health as tea is the main contributor to dietary flavonoids in Western countries. Consuming one to eight cups of black tea per day is associated with a reduced risk of chronic disease. Caffeine intakes at this level are moderate.