bluuebunny/crossref_metadata_2025 huggingface dataset:
Over, Under, or About Right: Misperceptions of Body Weight Among Food Stamp Participants
Authors: Ver Ploeg Michele L. , Chang Hung‐Hao , Lin Biing‐Hwan
Published: June 2008

The purpose of this research was to investigate the associations between misperception of body weight and sociodemographic factors such as food stamp participation status, income, education, and race/ethnicity. National Health and Nutrition Examination Survey (NHANES) data from 1999–2004 and multivariate logistic regression are used to estimate how sociodemographic factors are associated with (i) the probability that overweight adults misperceive themselves as healthy weight; (ii) the probability that healthy‐weight adults misperceive themselves as underweight; and (iii) the probability that healthy‐weight adults misperceive themselves as overweight. NHANES data are representative of the US civilian noninstitutionalized population. The analysis included 4,362 men and 4,057 women. BMI derived from measured weight and height was used to classify individuals as healthy weight or overweight. These classifications were compared with self‐reported categorical weight status. We find that differences across sociodemographic characteristics in the propensity to underestimate or overestimate weight status were more pronounced for women than for men. Overweight female food stamp participants were more likely to underestimate weight status than income‐eligible nonparticipants. Among healthy‐weight and overweight women, non‐Hispanic black and Mexican‐American women, and women with less education were more likely to underestimate actual weight status. We found few differences across sociodemographic characteristics for men. Misperceptions of weight are common among both overweight and healthy‐weight individuals and vary across socioeconomic and demographic groups. The nutrition education component of the Food Stamp Program could increase awareness of healthy body weight among participants.
Extracellular point mutations in FGFR2 elicit unexpected changes in intracellular signalling
Authors: Ahmed Zamal , Schüller Annika C. , Suhling Klaus , Tregidgo Carolyn , Ladbury John E.
Published: June 2008

An understanding of cellular signalling from a systems-based approach has to be robust to assess the effects of point mutations in component proteins. Outcomes of these perturbations should be predictable in terms of downstream response, otherwise a holistic interpretation of biological processes or disease states cannot be obtained. Two single, proximal point mutations (S252W and P253R) in the extracellular region of FGFR2 (fibroblast growth factor receptor 2) prolong growth factor engagement resulting in dramatically different intracellular phenotypes. Following ligand stimulation, the wild-type receptor undergoes rapid endocytosis into lysosomes, whereas SWFGFR2 (the S252W FGFR2 point mutation) and PRFGFR2 (the P253R FGFR2 point mutation) remain on the cell membrane for an extended period of time, modifying protein recruitment and elevating downstream ERK (extracellular-signal-regulated kinase) phosphorylation. FLIM (fluorescent lifetime imaging microscopy) reveals that direct interaction of FRS2 (FGFR substrate 2) with wild-type receptor occurs primarily at the vesicular membrane, whereas the interaction with the P253R receptor occurs exclusively at the plasma membrane. These observations suggest that the altered FRS2 recruitment by the mutant receptors results in an abnormal cellular signalling mechanism. In the present study these profound intracellular phenotypes resulting from extracellular receptor modification reveal a new level of complexity which will challenge a systems biology interpretation.
Effect of metal ions on high-affinity binding of pseudosubstrate inhibitors to PKA
Authors: Zimmermann Bastian , Schweinsberg Sonja , Drewianka Stephan , Herberg Friedrich W.
Published: June 2008

Conformational control of protein kinases is an important way of modulating catalytic activity. Crystal structures of the C (catalytic) subunit of PKA (protein kinase A) in complex with physiological inhibitors and/or nucleotides suggest a highly dynamic process switching between open and more closed conformations. To investigate the underlying molecular mechanisms, SPR (surface plasmon resonance) was used for detailed binding analyses of two physiological PKA inhibitors, PKI (heat-stable protein kinase inhibitor) and a truncated form of the R (regulatory) subunit (RIα 92–260), in the presence of various concentrations of metals and nucleotides. Interestingly, it could be demonstrated that high-affinity binding of each pseudosubstrate inhibitor was dependent only on the concentration of divalent metal ions. At low micromolar concentrations of Mg2+ with PKI, transient interaction kinetics with fast on- and off-rates were observed, whereas at high Mg2+ concentrations the off-rate was slowed down by a factor of 200. This effect could be attributed to the second, low-affinity metal-binding site in the C subunit. In contrast, when investigating the interaction of RIα 92–260 with the C subunit under the same conditions, it was shown that the association rate rather than the dissociation rate was influenced by the presence of high concentrations of Mg2+. A model is presented, where the high-affinity interaction of the C subunit with pseudosubstrate inhibitors (RIα and PKI) is dependent on the closed, catalytically inactive conformation induced by the binding of a nucleotide complex where both of the metal-binding sites are occupied.
Protein trafficking to plastids: one theme, many variations
Authors: Inaba Takehito , Schnell Danny J.
Published: June 2008

Plastids are a diverse group of essential organelles in plants that include chloroplasts. The biogenesis and maintenance of these organelles relies on the import of thousands of nucleus-encoded proteins. The complexity of plastid structure has resulted in the evolution of at least four general import pathways that target proteins into and across the double membrane of the plastid envelope. Several of these pathways can be further divided into specialty pathways that mediate and regulate the import of specific classes of proteins. The co-ordination of import by these specialized pathways with changes in gene expression is critical for plastid and plant development. Moreover, protein import is acutely regulated in response to physiological and metabolic changes within the cell. In the present review we summarize the current knowledge of the mechanism of import via these pathways and highlight the regulatory mechanisms that integrate the plastid protein-trafficking pathways with the developmental and metabolic state of the plant.
β-Arrestin multimers: does a crowd help or hinder function?
Authors: Defea Kathryn Anne
Published: June 2008

In this issue of the Biochemical Journal, Xu et al. describe how they use a spot peptide array to identify a unique sequence within β-arrestin-2 that is required for both multimerization and ERK1/2 (extracellular-signal-related kinase 1/2) scaffolding. They provide evidence that dimers may serve as more than just ‘storage forms’ of β-arrestins, incapable of interacting with receptors but, rather, perhaps, adding to the specificity of G-protein-coupled-receptor signalling. They show that key charged residues within this dimerization interface of β-arrestin-2 block association with ERK1/2 and subsequent activation of ERK1/2 by β2-adrenergic receptors, while internalization is unaffected. They suggest that self-association may serve as a means of sheltering scaffolding sites on β-arrestins from specific binding partners to prevent constitutive activation of key signalling pathways. These studies enhance our understanding of how β-arrestins can juggle their roles as scaffolds of multiple pathways in response to diverse signals.
Desire, Duras, and Melancholia: Theorizing Desire after the ‘Affective Turn’
Authors: Gorton Kristyn
Published: June 2008

This article considers how the concept of desire can be theorized in light of recent work on emotion and affect. In so doing, it questions what desire does and how desire can be theorized, particularly within cinema. Instead of arguing that we must move away from a psychoanalytic interpretation of desire, I ask how this approach can be revitalized and reconsidered through work on affect. This article also highlights the way in which Lacanian and Deleuzian models of desire are constantly set in opposition to each other; in so doing, it seeks to move beyond this impasse and gesture towards alternative ways of theorizing desire. One of the central issues foregrounded within psychoanalytic theory is the process of remembering and forgetting: the method through which the subject can ‘let go’ and move forward. This relationship is figured primarily in terms of the discourse between self and other. Marguerite Duras’ work questions this process of ‘letting go’ and offers an alternative conceptualization of desire through her use of melancholia. Beyond an intrinsic interest in her work, because Duras has been admired by psychoanalytic, feminist and Deleuzian scholars, her films present an opportunity to rethink a theorization of desire in light of competing interpretations. In discussing melancholia in terms of Duras’ work, this paper also considers the extent to which her use of Hiroshima as a backdrop to the affair presented in the film colonizes desire and its transformative potential.
Feminist-Nation Building in Afghanistan: An Examination of the Revolutionary Association of the Women of Afghanistan (RAWA)
Authors: Fluri Jennifer L.
Published: June 2008

Women-led political organizations that employ feminist and nationalist ideologies and operate as separate from, rather than associated with, male-dominated or patriarchal nationalist groups are both significant and under-explored areas of gender, feminist, and nationalism studies. This article investigates the feminist and nationalist vision of the Revolutionary Association of the Women of Afghanistan (RAWA). RAWA exemplifies an effective political movement that intersects feminist and nationalist politics, where women are active, rather than symbolic, participants within the organization, and help to shape an ideological construction of the Afghan nation. RAWA subsequently links its struggle for women's rights (through feminism) with its nationalist goals for democracy and secularism. This article also analyses RAWA's use of conservative nationalist methods to reproduce the future of the organization and to develop ‘citizens’ for its idealized nation, while countering existing patriarchal social and familial structures through a re-configuration of women's roles in the family, community, and nation. This inquiry is based on geographic and feminist examinations of RAWA's organizational structure, literature, and political goals obtained through content analyses of RAWA's political literature and through interviews with RAWA members and supporters living as refugees in Pakistan in the summer of 2003 and winter of 2004/05. RAWA is an instructive example of counter-patriarchal and nationalist feminist politics that questions patriarchal definitions of the nation and its citizenry by reconfiguring gender norms and redefining gender relations in the family as a mirror of the nation.
IR and Raman spectra of liquid water: Theory and interpretation
Authors: Auer B. M. , Skinner J. L.
Published: June 2008

IR and Raman (parallel- and perpendicular-polarized) spectra in the OH stretch region for liquid water were measured some years ago, but their interpretation is still controversial. In part, this is because theoretical calculation of such spectra for a neat liquid presents a formidable challenge due to the coupling between vibrational chromophores and the effects of motional narrowing. Recently we proposed an electronic structure/molecular dynamics method for calculating spectra of dilute HOD in liquid D2O, which relied on ab initio calculations on clusters to provide a map from nuclear coordinates of the molecules in the liquid to OH stretch frequencies, transition dipoles, and polarizabilities. Here we extend this approach to the calculation of couplings between chromophores. From the trajectories of the fluctuating local-mode frequencies, transition moments, and couplings, we use our recently developed time-averaging approximation to calculate the line shapes. Our results are in good agreement with experiment for the IR and Raman line shapes, and capture the significant differences among them. Our analysis shows that while the coupling between chromophores is relatively modest, it nevertheless produces delocalization of the vibrational eigenstates over up to 12 chromophores, which has a profound effect on the spectroscopy. In particular, our results demonstrate that the peak in the parallel-polarized Raman spectrum at about 3250 wavenumbers is collective in nature.
Infrared spectroscopy of methanol-hexane liquid mixtures. I. Free OH present in minute quantities
Authors: Max Jean-Joseph , Chapados Camille
Published: June 2008

Methanol and hexane mixtures covering the whole solubility range are studied by Fourier transform infrared attenuated total reflectance spectroscopy in order to evaluate OH groups that are H-bond-free. The mixtures from 0 to 0.25 and from 0.75to1.00mole fractions form homogeneous solutions, whereas those from 0.25to0.75mole fractions are inhomogeneous, forming two phases. Factor analysis (FA) was used to find out if free OH groups were present. These were found in minute quantities at the lowest mole fraction by evaluating the OH stretch absorption. The bulk of the absorption is due to the greater than 99.9% of hydrogen-bonded methanol molecules, with a band maximum situated at 3340cm−1. The stretch band of the free OH groups absorbs at 3654cm−1, with a full width at half maximum of 35cm−1. The concentration is very weak but constant at less than 5mM in the mole fraction between 0.252 and 0.067. Below this range, OH concentrations are even smaller. This represents less than 1% of the amount of methanol at the mole fraction of 0.067 (0.543M). Above 0.25 mole fraction, free methanol OH groups are not observed. Since the free OH band is very weak, almost at the noise level, we verified its presence with mixtures of hexanol in hexane. There, we found a similar free OH band with almost the same band characteristics, but with almost three times the concentrations found with methanol, which we attribute to the difference in the hydrocarbon chain length. The present study indicates clearly that solutions of methanol in hexane contain free OH groups but in minute quantities and only in the low methanol concentrations. This situation is much different from that observed in solutions of methanol in CCl4, where free OH groups are clearly observed at all concentrations except at the concentration limits. Whereas in CCl4, methanol is believed to form H-bonded chains, the situation is different in n-hexane: methanol in the low concentration region would form reverse micelles with the OH groups in the core and the CH3 groups mixed with n-hexane molecules.
Numerical integration of exchange-correlation energies and potentials using transformed sparse grids
Authors: Rodríguez Juan I. , Thompson David C. , Ayers Paul W. , Köster Andreas M.
Published: June 2008

A new numerical integration procedure for exchange-correlation energies and potentials is proposed and “proof of principle” results are presented. The numerical integration grids are built from sparse-tensor product grids (constructed according to Smolyak’s prescription [Dokl. Akad. Nauk. 4, 240 (1963)] ) on the unit cube. The grid on the unit cube is then transformed to a grid over real space with respect to a weight function, which we choose to be the promolecular density. This produces a “whole molecule” grid, in contrast to conventional integration methods in density-functional theory, which use atom-in-molecule grids. The integration scheme was implemented in a modified version of the DEMON2K density-functional theory program, where it is used to evaluate integrals of the exchange-correlation energy density and the exchange-correlation potential. Ground-state energies and molecular geometries are accurately computed. The biggest advantages of the grid are its flexibility (it is easy to change the number and distribution of grid points) and its whole molecule nature. The latter feature is potentially helpful for basis-set-free computational algorithms.
In vitro evaluation of flexible pH and potassium ion-sensitive organic field effect transistor sensors
Authors: Ji Taeksoo , Rai Pratyush , Jung Soyoun , Varadan Vijay K.
Published: June 2008

Acute myocardial ischemia is a state of trauma of the heart muscle caused by occlusion of oxygenated blood supply. It is accompanied by an increase in potassium and hydrogen ion concentrations in the heart muscles. A flexible substrate based ion-sensitive field effect transistor (ISFET) has been designed to measure the concentration of potassium and hydrogen ions with high specificity. Double exponential smoothing technique was used to calculate background noise and explain the dependence of drain current on reference voltage and ion concentration in saturation mode of the ISFET.
Fluorescent glass embedded silver nanoclusters: An optical study
Authors: Karthikeyan B.
Published: June 2008

In this report, the light emitting behavior of silver nanoclusters embedded in sodalime glass through ion-exchange technique is studied. The cluster sizes were varied through thermal annealing. The optical absorption spectra were recorded for all the glasses. The variation of surface plasmon resonance peak with the annealing temperature was found. Fourier transform infrared spectral measurement was utilized to identify the chemical interface damping. Photoluminescence measurements were carried out and time resolved photoluminescence was performed to identify the time evolution of emission.
Effects of d-electrons in pseudopotential screened-exchange density functional calculations
Authors: Lee Byounghak , Wang Lin-Wang , Canning Andrew
Published: June 2008

We report a theoretical study on the role of shallow d states in the screened-exchange local density approximation (sX-LDA) band structure of binary semiconductor systems. We found that inaccurate pseudo-wave functions can lead to (1) an overestimation of the screened-exchange interaction between the localized d states and the delocalized higher energy s and p states, and (2) an underestimation of the screened-exchange interaction between the d states. The resulting sX-LDA band structures have substantially smaller band gaps compared with experiments. We correct the pseudo-wave functions of d states by including the semicore s and p states of the same shell in the valence states. The correction of pseudo-wave functions yields band gaps and d-state binding energies in good agreement with experiments and the full potential linearized augmented plane wave sX-LDA calculations. Compared with the quasiparticle GW method, our sX-LDA results shows not only similar quality on the band gaps but also much better d-state binding energies. Combined with its capability of ground-state structure calculation, the sX-LDA is expected to be a valuable theoretical tool for the II-VI and III-V (especially the III-N) bulk semiconductors and nanostructure studies.
Dichotomy of the exciton wave function in semiconductors under intense laser fields
Authors: Lima F. M. S. , Nunes O. A. C. , Amato M. A. , Fonseca A. L. A. , da Silva E. F.
Published: June 2008

We study the behavior of excitons in a semiconductor irradiated by a monochromatic, linearly polarized, intense laser field. By taking the finiteness of the hole effective mass into account and including the radiation field in a semiclassical manner, we solved the two-body quantum problem in the framework of a nonperturbative theory based upon the Kramers-Henneberger translation transformation for the Schrödinger equation. In the Kramers frame, the rapidly oscillating potential is expanded in a Fourier-Floquet series and, for laser frequencies high enough, only the zeroth-order term survives, the so-called “laser-dressed” potential. By applying the Ehlotzky’s approximation, this potential simplifies to a two-center potential that resembles that for the electronic motion in the H2+ molecule ion. The binding energy for an exciton in bulk GaAs under a nonresonant laser field is then computed by following a variational scheme we recently adapted from the linear combination of atomic orbitals-molecular orbitals method for the H2+ system. Similarly to the binding energy in H2+ in the separated-atoms limit, we found that, instead of vanishing, the exciton binding energy tends to a quarter of the excitonic Rydberg energy with the increase of the laser intensity. We also trace a correlation between this residual binding and the dichotomy of the excitonic wave function in the large dressing parameter limit, which indicates the possibility of excitons becoming stable against ionization.
Thermal behavior of the microstructure and the electrical properties of magnetron-sputtered high-k titanium silicate thin films
Authors: Brassard D. , El Khakani M. A.
Published: June 2008

We report on the high-temperature stability of high-dielectric-constant (high-k) titanium silicate (Ti0.5Si0.5O2) thin films deposited by means of a magnetron sputtering process. We have investigated the effect of substrate deposition temperature Td (in the 20–600°C range) and postdeposition annealing temperature Ta (in the 200–800°C range) on the electrical, microstructural, and optical properties of the films. The Ti-silicate films grown at room temperature were found to exhibit a combination of excellent electrical properties, including a k-value of 16.5, a leakage current as low as 3nA at 1MV∕cm, and a dissipation factor tan(δ)<0.01. On the other hand, when the processing temperature (Td or Ta) is ⩾300°C, the leakage current of the films is found to degrade progressively. The x-ray diffraction, Raman spectroscopy, and transmission electron microscopy characterizations have shown that the Ti-silicate films exhibit an amorphous microstructure up to a temperature of about 600°C. For higher temperatures, (i.e., Td of 600°C or a Ta⩾700°C) some anatase TiO2 nanocrystallites (in the 1.5–5nm size range) formation is evidenced. This TiO2 nanocrystallite precipitation results from a thermally induced phase segregation of TiO2-rich and SiO2-rich environments, which is shown to be initiated at rather low processing temperatures. This progressive phase segregation, which leads to the precipitation of a low band gap and leaky TiO2-rich phase in the films, is believed to be at the origin of the observed degradation of the leakage current of the Ti-silicate films with increasing temperatures (Td or Ta).
Nonlinear dynamics of absorption and photobleaching of dyes
Authors: Serra Francesca , Terentjev Eugene M.
Published: June 2008

The celebrated Lambert–Beer law of light absorption in photochromic media is only valid at low intensities of incident light and low concentration of chromophore. Here we address the generic problem of photoabsorption dynamics, experimentally studying the case of azobenzene isomerization. We show that the nonlinear regime is very common and easy to achieve in many practical situations, especially in thick samples where the light depletes the chromophore in the first layers and can propagate through the medium with a subexponential law. This result holds not only for azobenzene isomerization but for all photochromic processes. Importantly, the crossover into the nonlinear absorption regime only weakly depends on the dye concentration and solution viscosity. We experimentally quantify the characteristics of this peculiar optical response and determine the key transition rate constants.
Structural ordering in CdxPb1−xF2 alloys: A combined molecular dynamics and solid state NMR study
Authors: Picinin Adalberto , Deshpande Rashmi R. , de Camargo Andrea S. S. , Donoso José Pedro , Rino José Pedro , Eckert Hellmut , Silva Maurício A. P.
Published: June 2008

Molecular dynamics (MD) simulations of binary CdxPb1−xF2 alloys have been carried out, using a two-body Buckingham interaction potential, leading to a correct description of structural properties as a function of composition and pointing towards an understanding of the eutectic phenomenon. The simulation data can be analyzed in terms of five local fluorine environments Q(n) (4⩾n⩾0), where n is the number of Pb nearest-neighbor environments. The results suggest a highly nonstatistical population distribution, suggesting an intrinsic phase segregation tendency in the undercooled melt, during the cooling process. This prediction has been tested experimentally for six representative compositions (0.2⩽x⩽0.7) on the basis of high-resolution F19 solid state NMR data, revealing important similarities between theory and experiment. While the NMR data confirm that the population distribution is, indeed, nonstatistical for all compositions, the results are only found to be consistent with an intrinsic segregation tendency of PbF2-rich domains. This tendency manifests itself in substatistical populations of Q(3) units, resulting in preferred Q(2) and Q(4) formations.
Resonance Raman and theoretical investigation of the photodissociation dynamics of benzamide in S3 state
Authors: Pei Ke-Mei , Ma Yufang , Zheng Xuming
Published: June 2008

Resonance Raman spectra were obtained for benzamide in methanol and acetonitrile solutions with excitation wavelengths in resonance with the S3 state. These spectra indicate that the Franck–Condon region photodissociation dynamics have multidimensional character with the motions mainly along the benzene ring CC stretch ν9, the Ph–CO–NH2 and ring benzene stretch ν14, the CCH in plane bend ν17, the Ph–CO–NH2 stretch and NH2 rock ν19, the ring trigonal bend ν23, and the ring deformation and Ph–CO–NH2 stretch ν29. A preliminary resonance Raman intensity analysis was done, and the results were compared to those previously reported for acetophenone to examine the substituent effect. Solvent effect on the short-time photodissociation dynamics of benzamide was also examined. A conical intersection point S2∕S3 between S3 and S2 potential energy surfaces of benzamide was determined by using a complete active space self-consistent field theory computations. The structural differences and similarities between S3∕S2 point and S0 were examined, and the results were used to correlate to the Franck–Condon photodissociation dynamics of benzamide in S3 state.
Localized surface plasmons in Al∕Si structure and Ag∕SiO2∕Ag emitter with different concentric metal rings
Authors: Chang Yi-Tsung , Ye Yi-Han , Tzuang Dah-Ching , Wu Yi-Ting , Yang Chieh-Hung , Chan Chi-Feng , Jiang Yu-Wei , Lee Si-Chen
Published: June 2008

This paper reports the optical properties of Al∕Si structure and trilayer Ag∕SiO2∕Ag plasmonic thermal emitter with different concentric metal rings on top metal film. It is found that when the metal width is smaller than 40% of the period (=gap+metal width), the (1,0) Al∕Si surface plasmon leads to a maximum in the transmission spectra; otherwise, the opposite is observed. The dispersion relations and emission spectra of the plasmonic thermal emitters were investigated. The emission peaks are independent of the gap width and redshift as annular metal width increases. This phenomenon suggests the excitation of Fabry-Pérot type resonance within cavity of Ag∕SiO2∕Ag structure. No (1,0) Ag∕SiO2 surface plasmon was observed.
High frequency measurements on an AlN∕GaN-based intersubband detector at 1550 and 780nm
Authors: Hofstetter D. , Baumann E. , Giorgetta F. R. , Dawlaty J. , George P. A. , Rana F. , Guillot F. , Monroy E.
Published: June 2008

We report on high frequency measurements on an AlN∕GaN-based intersubband detector using mode-locked solid state lasers. Our experiments involving laser wavelengths of 1550 and 780nm demonstrate not only the capability of such devices to work both at the fundamental and at a higher order intersubband transition, but they also allowed us to push the high frequency detection limit up to a value of 13.3GHz. From the shape of the harmonic decay, we conclude that this limit is not due to intrinsic properties of the detector.
Defect-induced degradation of rectification properties of aged Pt∕n-InxZn1−xOy Schottky diodes
Authors: Kim K. H. , Kang B. S. , Lee M.-J. , Ahn S.-E. , Lee C. B. , Stefanovich G. , Xianyu W. X. , Kim K.-K. , Kim J. S. , Yoo I. K. , Park Y.
Published: June 2008

In this study, Pt/IZO (InxZn1−xOy) Schottky diodes were fabricated and the degradation phenomenon was investigated. The Pt/IZO Schottky diodes showed a rectifying ratio of 105, however, the electrical properties were degraded with aging. An increase in defect and carrier concentrations was observed from capacitance-voltage analysis and photoluminescence in the aged Pt/IZO Schottky diode. The degradation of the rectifying properties of the aged diodes originates possibly from the electron tunneling due to the increased defect concentrations.
Luminescence and microstructure of Sm2+ ions reduced by x-ray irradiation in Li2O–SrO–B2O3 glass
Authors: Huang Yanlin , Jiang Chuanfang , Jang Kiwan , Lee Ho Sueb , Cho Eunjin , Jayasimhadri M. , Yi Soung-Soo
Published: June 2008

Sm 3 + -doped Li2O–SrO–B2O3 glass sample was prepared by the conventional melt quenching method in air atmosphere. Sm2+ ions in this borate glass were obtained by x-ray irradiation reduction method. The as-prepared and x-ray-irradiated samples were investigated by photoluminescence spectrum and decay curve measurements. The dependence of Sm2+ luminescence intensity on the x-ray irradiation time was investigated. It is found that the conversion of Sm3+→Sm2+ after x-ray irradiation is efficient in this borate glass. Photostability of Sm2+ ions was evaluated by the photobleaching method. Furthermore, the induced optical absorption spectrum measurement after x-ray irradiation was performed. Thermoluminescence above room temperature was also studied after x-ray irradiation. The different kinds of defect structures and the reduction mechanism of Sm2+ ions in this borate glass were discussed. The microstructure of Sm ions in the Li2O–SrO–B2O3 glass was suggested. The proposed microstructure would be helpful to understand the reduction mechanism of Sm2+ ion in borate glasses.
Layer-by-layer epitaxial growth of Mg on GaN(0001)
Authors: Pezzagna S. , Vézian S. , Brault J. , Massies J.
Published: June 2008

It is shown that Mg deposition at room temperature on a GaN(0001) surface, obtained in situ by molecular beam epitaxy, gives rise to a layer-by-layer epitaxial growth mode. The study by reflection high-energy electron diffraction and scanning tunneling microscopy clearly evidences that a two-dimensional nucleation growth mechanism occurs from the very first Mg monolayer deposited. A complete covering of the GaN surface is obtained from the deposition of the first two monolayers of Mg.
Optical properties and morphology of InAs∕InP (113)B surface quantum dots
Authors: Nakkar A. , Folliot H. , Le Corre A. , Doré F. , Alghoraibi I. , Labbé C. , Elias G. , Loualiche S. , Pistol M.-E. , Caroff P. , Ellström C.
Published: June 2008

We report on long-wavelength photoluminescence (PL) emission at room temperature from self-organized InAs surface quantum dots grown by gas-source molecular beam epitaxy on a GaInAsP∕InP (113)B substrate. The influence of arsenic pressure conditions during growth on the PL emission of surface quantum dots is detailed as well as oxide/contamination layer formation after growth. Experimental results are in good agreement with six-band k⋅p theory in the envelope function approximation.
Influence of molecular weight and conformation on single-photon emission from isolated conjugated polymer chains
Authors: Masuo Sadahiro , Tanaka Tomoya , Machida Shinjiro , Itaya Akira
Published: June 2008

The influence of molecular weight (MW) and chain conformation on single-photon emission from isolated chains of poly[2-methoxy,5-(2′-ethylhexyloxy)-p-phenylene-vinylene] have been investigated. The probability of single-photon emission clearly increased with decreasing MW, and when the polymer chains adopted the “collapsed” conformation, this probability was larger than for the “extended” conformation. Even single polymer chains of high MW behaved as single-photon sources by adopting the collapsed conformation. These results indicate that multi-quantum systems consisting of a large number of chromophores can be made to behave as single-photon sources by appropriately controlling their size.
Dopant-stress synergy in Si solid-phase epitaxy
Authors: Rudawski N. G. , Jones K. S. , Gwilliam R.
Published: June 2008

The influence of dopants on stressed solid-phase epitaxy of Si was studied in B-doped material up to B concentration of ∼3.0×1020cm−3 and stress of 1.0±0.1GPa. As per the generalized Fermi level shifting model of growth enhancement in the presence of electrically active impurities, it is advanced that application of compressive stress may increase the energy difference between intrinsic Fermi and acceptor levels thus making dopant and stress effects synergistic in growth kinetics.
Impact of the electrical connection of spin transfer nano-oscillators on their synchronization: an analytical study
Authors: Georges B. , Grollier J. , Cros V. , Fert A.
Published: June 2008

We analytically study the impact of an electrical connection of spin transfer nano-oscillators (STNOs) on their synchronization. We demonstrate that the phase dynamics of coupled STNO arrays can be described in the framework of the Kuramoto model. The conditions for successful synchronization of an assembly of STNOs are formulated. Synchronizing an assembly of STNOs appears to be the only solution to make the breakthrough on the emitted output power toward frequency synthesizers. In these potential devices, a large number of STNOs will have to be electrically connected, whatever the coupling mechanisms between oscillators.
Emergence of Multidrug Resistance in Bacteria and Impact on Antibiotic Expenditure at a Major Army Medical Center Caring for Soldiers Wounded in Iraq and Afghanistan
Authors: Zapor Michael J. , Erwin Daniel , Erowele Goldina , Wortmann Glenn
Published: June 2008

Since the invasions of Iraq and Afghanistan, the epidemiologic traits of clinical isolates at Walter Reed Army Medical Center have shifted toward drug-resistant strains of microorganisms, particularly among the gram-negative bacteria. Moreover, antibiotic prescribing patterns during this period have changed remarkably and mirror the emergence of these organisms at our institution.
CHARGE-COUPLED DEVICE SPECKLE OBSERVATIONS OF BINARY STARS WITH THE WIYN*
TELESCOPE. V. MEASURES DURING 2001–2006
Authors: Horch Elliott P. , van Altena William F. , Cyr William M. , Kinsman-Smith Lori , Srivastava Amit , Zhou Jing
Published: June 2008

A total of 1067 speckle observations of 345 binary stars are presented. Of these, 161 are double stars first resolved by Hipparcos, 17 are resolved for the first time in the observations presented here, and 21 are stars previously discovered by our program and reported in earlier papers in the series. In 947 cases, a magnitude difference is reported along with the relative astrometry. When comparing to systems with very well-known orbits, we find that the root mean square (rms) deviation in separation residuals is 2.81 ± 0.28 mas, and the rms deviation in position angle residuals is 0.88 ± 0.07°. The magnitude difference measures show no significant deviation from Hipparcos photometry, and have average standard deviation of approximately 0.10 mag as judged from repeat observations. Five important systems discovered by Hipparcos are discussed.
Effects of multimedia and schema induced analogical reasoning on science learning
Authors: Zheng R.Z. , Yang W. , Garcia D. , McCadden E.P.
Published: June 2008

The present study investigates the effects of multimedia and schema induced analogical reasoning on science learning. It involves 89 fourth grade elementary students in the north‐east of the United States. Participants are randomly assigned into four conditions: (a) multimedia with analogy; (b) multimedia without analogy; (c) analogy without multimedia; and (d) non‐multimedia and non‐analogy. The multivariate analyses of covariance reveal significant main effects for multimedia and analogy learning as well as a significant interaction between multimedia and analogy. The findings show that schema induced analogical reasoning can significantly improve science learning and that multimedia becomes more effective when it is integrated with an instructional method such as analogy and less so when it is used only as a visual tool. The study also shows the field dependence/independence as a significant covariate that influences learners' schema induced analogical reasoning in learning. Discussions pertaining to the significance of the findings and their implications for teaching and learning are made. Suggestions for future research are included with an emphasis on developing multimedia supported analogical reasoning for science learning.
Site‐specific receptor methylation of FrzCD in Myxococcus xanthus is controlled by a tetra‐trico peptide repeat (TPR) containing regulatory domain of the FrzF methyltransferase
Authors: Scott Ansley E. , Simon Eric , Park Samuel K. , Andrews Philip , Zusman David R.
Published: June 2008

Myxococcus xanthus is a gliding bacterium with a complex life cycle that includes swarming, predation and fruiting body formation. Directed movements in M. xanthus are regulated by the Frz chemosensory system, which controls cell reversals. The Frz pathway requires the activity of FrzCD, a cytoplasmic methyl‐accepting chemotaxis protein, and FrzF, a methyltransferase (CheR) containing an additional domain with three tetra trico‐peptide repeats (TPRs). To investigate the role of the TPRs in FrzCD methylation, we used full‐length FrzF and FrzF lacking its TPRs (FrzFCheR) to methylate FrzCD in vitro. FrzF methylated FrzCD on a single residue, E182, while FrzFCheR methylated FrzCD on three residues, E168, E175 and E182, indicating that the TPRs regulate site‐specific methylation. E168 and E182 were predicted consensus methylation sites, but E175 is methylated on an HE pair. To determine the roles of these sites in vivo, we substituted each methylatable glutamate with either an aspartate or an alanine residue and determined the impact of the point mutants on single cell reversals, swarming and fruiting body formation. Single, double and triple methylation site mutants revealed that each site played a unique role in M. xanthus behaviour and that the pattern of receptor methylation determined receptor activity. This work also shows that methylation can both activate and inactivate the receptor.
Vascular endothelial growth factor gene polymorphisms in Turkish patients with sarcoidosis
Authors: Seyhan E. C. , Cetinkaya E. , Altin S. , Gunluoglu M. Z. , Demir A. , Koksal V. , Issever H.
Published: June 2008

Polymorphism at +813 locus of vascular endothelial growth factor (VEGF) gene is considered to decrease predisposition to sarcoidosis. Our study aimed to investigate the roles of this polymorphism in the development and extent of sarcoidosis. We examined polymorphisms of the VEGF gene in 90 cases with histopathological diagnosis of sarcoidosis and in 110 healthy subjects. VEGF +813 gene polymorphisms were determined using a polymerase chain reaction‐based method after DNA isolation. A significant increase in the frequency of the T allele was found in healthy subjects (odds ratio 0.55; 95% confidence interval 0.32–0.97,P < 0.05). Our results suggest that increase in rarer T allele at + 813 locus of VEGF gene may diminish susceptibility to sarcoidosis in Turkish population.
Identification of a novel HLA‐B allele, HLA‐B*3713, in a Chinese individual
Authors: Lin W. , Shan X. , Zhang Z.
Published: June 2008

A novel human leukocyte antigen (HLA) class I allele, HLA‐B*3713, has been identified in a Chinese individual. The HLA‐B*3713 allele differs from the closest matching allele B*370101 by one nucleotide substitutions in exon 3 at nt 527(T→A), resulting in an amino acid change from Val (GTG) to Glu (GAG) at codon 152.
Clinical utility of intraductal US to decrease early recurrence rate of common bile duct stones after endoscopic papillotomy
Authors: Tsuchiya Shin , Tsuyuguchi Toshio , Sakai Yuji , Sugiyama Harutoshi , Miyagawa Kaoru , Fukuda Yoshihiro , Ando Takeshi , Saisho Hiromitsu , Yokosuka Osamu
Published: June 2008

Background and Aim:  The aim of the present study was to determine whether additional intraductal ultrasound (IDUS) to confirm complete stone clearance decreases the recurrence rate of common bile duct stones for a 3‐year period after endoscopic papillotomy (EPT).

Methods:  IDUS was carried out with a thin‐caliber ultrasonic probe (diameter 2.0 mm, frequency 20 MHz) via transpapillary route after stone extraction. If IDUS showed evidence of residual stones and/or sludge, endoscopic management was performed until IDUS examination was negative. A prospective study was conducted on 59 consecutive patients undergoing additional IDUS after stone extraction between January 1996 and May 2003 (IDUS group). The recurrence rate of common bile duct stones was compared with a historical control group (August 1988 to December 1995) consisting of cases that did not undergo IDUS (non‐IDUS group). Potential risk factors for recurrence of common bile duct stones were assessed by univariate and multivariate analysis on logistic regression.

Results:  In 14 of 59 patients (23.7%), IDUS detected small residual stones not seen on cholangiography. The recurrence rate was 13.2% (17 of 129 patients) in the non‐IDUS group and 3.4% (two of 59 patients) in the IDUS group (P < 0.05). Multivariate analysis subsequently identified non‐IDUS status as an independent risk factor for recurrence (odds ratio 5.12, 95% CI 1.11–23.52, P = 0.036).

Conclusions:  Additional IDUS to confirm complete stone clearance after EPT decreases the early recurrence rate of common bile duct stones.
Prion disease causes less severe lesions in human hippocampus than other parts of brain
Authors: Kaneko Minoru , Sugiyama Nobuhiro , Sasayama Daimei , Yamaoka Keiko , Miyakawa Tomohiro , Arima Kunimasa , Tsuchiya Kuniaki , Hasegawa Kazuko , Washizuka Shinsuke , Hanihara Tokisi , Amano Naoji , Yagishita Saburo
Published: June 2008

Aim:  The hippocampus can be very sensitive to damage in the scrapie‐infected mouse, a well‐established animal model of prion diseases. Terminally ill scrapie‐infected animals exhibit nearly complete loss of cornu ammonis (CA) 1 pyramidal neurons, but few studies have focused on the neuropathological lesions of the human hippocampus in autopsied brain tissue; in particular, few findings on differences in severity of pathology between the hippocampal and parahippocampal formations have been obtained. The aim of the present paper is to evaluate the human hippocampus of prion disease through neuropathological examination.

Methods:  A systemic, detailed neuropathological study throughout the subdivisions of the hippocampus was carried out in 23 autopsied cases of prion diseases. Prion protein immunohistochemistry was performed in serial brain sections to determine the topography of prion deposits.

Results:  Compared to lesions in other brain regions, hippocampal lesions were mild, despite numerous prion deposits. The distribution of prion deposits did not appear to be correlated with neuropathological changes. The present findings differed from the hippocampal pathology observed in scrapie‐infected mice. In addition, differences in neuropathological severity were observed within the hippocampal formation.

Conclusion:  The human hippocampus may be protected from the neurotoxic effects of prion deposits.
Classification of adult patients with type 2 diabetes using the Temperament and Character Inventory
Authors: Yoda Noriko , Yamashita Tatsuhisa , Wada Yoshihisa , Fukui Michiaki , Hasegawa Goji , Nakamura Naoto , Fukui Kenji
Published: June 2008

Aim:  Adult patients with type 2 diabetes were classified using the Temperament and Character Inventory (TCI). This classification was used to propose effective therapeutic approaches based on subtypes of psychological characteristics.

Methods:  The TCI and various psychological tests were administered to 89 patients (54 men and 35 women). Cluster analysis was performed using three temperament factors of the TCI as variables for subclassification: novelty seeking (NS), harm avoidance (HA) and reward dependence (RD).

Results:  The patients were divided into two clusters based on the TCI results. Cluster 1 had a low NS/high HA/low RD pattern, which indicated resistance to change and lack of cooperativeness, and results of other tests indicated that patients in cluster 1 were obsessional and had weak intention and personality disorder symptoms. In contrast, cluster 2 had a high NS/low HA/high RD pattern, indicating a socially active person who easily becomes dependent on others, and results of other tests indicated that these patients were histrionic and less anxious. In cluster 1 there was a significant negative correlation between hemoglobin A1c (HbA1c) and SD‐1 (TCI self‐directedness) ‘responsibility’ and a significant positive correlation between HbA1c and State anxiety of State–Trait Anxiety Inventory. In cluster 2 there was a significant positive correlation between HbA1c and HA‐2 ‘fear of uncertainty’.

Conclusions:  Patients with type 2 diabetes were classified using the TCI into two subgroups. These two groups differed in psychological characteristics and had a different pattern in correlation with glycemic control.
Development of the Nurse Attitude Scale short form: Factor analysis in a large sample of Japanese psychiatric clinical staff
Authors: Katsuki Fujika , Fukui Satoe , Niekawa Nobuyuki , Oshima Iwao , Setoya Nozomi , Ninomiya Shiori , Moriyama Akiko , Uchino Toshiro , Ito Junichiro , Tsukada Kazumi
Published: June 2008

The Nurse Attitude Scale (NAS) measures nurses' Expressed Emotion. A short form of the NAS was developed and its reliability and validity examined. After performing factor analysis using 1252 samples, three factors were extracted. Cronbach's α for individual subscales was 0.852 for Hostility, 0.846 for Criticism and 0.645 for Positive Remarks. There was a significant correlation between individual subscales in the NAS short form and corresponding subscale in the Maslach Burnout Inventory (P < 0.001). The NAS short form seems to have acceptable reliability and validity.
Prevalences of lifetime histories of self‐cutting and suicidal ideation in Japanese adolescents: Differences by age
Authors: Matsumoto Toshihiko , Imamura Fumi , Chiba Yasuhiko , Katsumata Yotaro , Kitani Masahiko , Takeshima Tadashi
Published: June 2008

We examined differences in the prevalence of a lifetime history of self‐cutting and suicidal ideation by age among junior and senior high‐school students. Histories of self‐cutting and suicidal ideation were reported by 9.9% and 40.4% of the students. Among early teens, females were more likely to report suicidal ideation than males, and among late teens, females were more likely than males to report self‐cutting.