bluuebunny/crossref_metadata_2025 huggingface dataset:
The CRP genotype, serum levels and lung function in men: the Caerphilly Prospective Study
Authors: Bolton Charlotte E. , Schumacher Wiebke , Cockcroft John R. , Timpson Nicholas J. , Smith George Davey , Gallacher John , Rumley Anne , Lowe Gordon D. , Ebrahim Shah , Shale Dennis J. , Ben-Shlomo Yoav
Published: November 2010

Systemic CRP (C-reactive protein) has been associated with impaired lung function. A causal relationship would increase the value of CRP as both a diagnostic and therapeutic tool. We assessed the association between lung function parameters, circulating CRP and CRP polymorphisms using Mendelian randomization in efforts to attribute causality to known associations. Spirometric parameters of FEV1 (forced expiratory volume in 1 s) and FVC (forced vital capacity) were determined in 2173 men participating in the Caerphilly Prospective Study. Lung function measures on 1021 participants were available at follow-up (mean, 16.8 years later). Serum CRP levels were measured at baseline, and three CRP polymorphisms were analysed. Haplotype analysis was performed. Serum CRP levels at baseline were inversely associated with contemporaneous FEV1 and FVC as well as at follow-up (P<0.001) even after adjustment for conventional confounders. Serum CRP was associated with FEV1 decline (P=0.04). All three CRP polymorphisms (rs1800947, rs1130864 and rs1205) predicted serum CRP; however, there were no clear associations of the polymorphisms or haplotypes with lung function or with lung function decline. In conclusion, serum CRP was associated with lung function cross-sectionally; however, CRP polymorphisms were not associated with lung function or decline, suggesting that the CRP–lung function relationship is due to reverse causality, an unmeasured confounding factor or only has a modest causal effect.
Ethical Principles Associated With the Publication of Research in ASHA’s Scholarly Journals: Importance and Adequacy of Coverage
Authors: Ingham Janis C. , Minifie Fred D. , Horner Jennifer , Robey Randall R. , Lansing Charissa , McCartney James H. , Slater Sarah C. , Moss Sharon E.
Published: November 2010

Purpose

The purpose of this 2-part study was to determine the importance of specific topics relating to publication ethics and adequacy of the American Speech-Language-Hearing Association’s (ASHA’s) policies regarding these topics.

Method

A 56-item Web-based survey was sent to (a) ASHA journal editors, associate editors, and members of the Publications Board (Group 1); (b) authors, reviewers, and members of ASHA’s Board of Ethics (Group 2); and (c) a random sample of the ASHA membership, characterized as journal readers (Group 3). The survey contained 4 questions related to ethical principles associated with the publication of research: (a) In regard to scientific integrity in research publications in general, how important is the issue of [topic]? (b)
Should
ASHA publication policies address this issue? (c)
Do
ASHA policies address this issue? (d) If yes, how adequately do ASHA policies address this issue? A second study evaluated the contents of ASHA’s publication policy documents in regard to their coverage of the survey topics.

Results

Results indicated many of the topics deemed most important by all groups were included in ASHA’s publication policy documents; other topics, although included, were not adequately addressed.

Conclusions

ASHA needs a single, unifying publication policy document, and increased education of all groups in the realm of ethics in the publication process is indicated.
Responsible Conduct of Research in Communication Sciences and Disorders: Faculty and Student Perceptions
Authors: Minifie Fred D. , Robey Randall R. , Horner Jennifer , Ingham Janis C. , Lansing Charissa , McCartney James H. , Alldredge Elham-Eid , Slater Sarah C. , Moss Sharon E.
Published: November 2010

Purpose

Two Web-based surveys (Surveys I and II) were used to assess perceptions of faculty and students in Communication Sciences and Disorders (CSD) regarding the responsible conduct of research (RCR).

Method

Survey questions addressed 9 RCR domains thought important to the responsible conduct of research: (a) human subjects protections; (b) research involving animals; (c) publication practices and responsible authorship; (d) mentor/trainee responsibilities; (e) collaborative science; (f) peer review; (g) data acquisition, management, sharing, and ownership; (h) conflicts of interest; and (i) research misconduct. Respondents rated each of 37 topics for importance and for sufficiency of instructional coverage.

Results

Respondents to Survey I were 137 faculty members from 68 (26%) of the 261 graduate programs in CSD. By comparison, 237 students from 39 (15%) programs responded to Survey II. Data about the importance and sufficiency of coverage of each of the 37 items were transformed intozscores to reveal relative ratings among the 37 topics. Data presentations were grouped for topics in each of the 9 RCR domains. Ratings indicated the relatively high importance assigned among the 37 topics by CSD faculty and students. Sufficiency of coverage of those same topics received lower ratings.

Conclusions

The results of these surveys support the notion that students in CSD perceive that they are receiving information about RCR. The data pertaining to sufficiency of coverage provide a basis for improving instruction in this important aspect of research education.
Research Integrity in Communication Sciences and Disorders: Preface
Authors: Moss Sharon E.
Published: November 2010

Purpose

A joint program on Research on Research Integrity sponsored by the National Institute of Neurological Disorders and Stroke and the Office of Research Integrity encouraged the examination of practices and policies promoting the responsible conduct of research (RCR). The authors' grant—Research Integrity in ASHA: Education and Publication—enabled American Speech-Language-Hearing Association’s (ASHA) Research Integrity Grant Group to (a) identify patterns of teaching and learning in Communication Sciences and Disorders graduate programs about specific topics of research integrity on the conduct of science, (b) examine perceptions about concepts of research integrity as they apply to scientific journals within the discipline, and (c) evaluate policies and practices established by ASHA to protect the integrity of published scientific work.

Method

The authors reviewed historical and contemporary literature, conducted surveys, and analyzed ASHA policies.

Conclusion

This supplement of the
Journal of Speech, Language, and Hearing Research
has been written with the aim of informing and inspiring scientists, students, research institutions, and professional societies to practice responsible research in the 21st century and beyond.
Occlusion vs. skin barrier function
Authors: Zhai Hongbo , Maibach Howard I.
Published: November 2010

Background/aims: Skin occlusion may increase percutaneous absorption of applied chemicals, with some exceptions. It also obstructs the normal ventilation of the skin surface and increases stratum corneum hydration and hence compromises skin barrier function.

Methods/results: This review focuses the effects of occlusion on skin barrier function, in particularly, as defined with objective skin bioengineering technology.

Conclusions: The effects of occlusion on skin barrier function have been defined with various techniques. Optimal hydrocolloid materials can absorb excess water and reduce the unfavourable effects of occlusion.
Special 301 of the Trade Act of 1974 and Global Access to Medicines
Authors: Flynn Sean M.
Published: November 2010

Since its inception in 1988, the United States Trade Representative's ‘Special 301’ adjudication of foreign intellectual property law standards has been used to promote policies restricting access to affordable medications around the world. President-elect Obama released a platform promising to ‘break the stranglehold that a few big drug and insurance companies have on these life-saving drugs’ and pledged support for ‘the rights of sovereign nations to access quality-assured, low-cost generic medication to meet their pressing public health needs’. The 2009 and 2010 Special 301 Reports, however, indicate that the Obama Administration has not yet implemented this pledge into administration trade policy. Although the 2010 Report shows some improvement, the Obama Administration continues using Special 301 to pressure developing countries to adopt escalating intellectual property rules that are not required by any international agreement and that will negatively impact access to medicines.
The effect of rim-shroud gap on the spiral rolls formed around a rotating disk
Authors: Watanabe Takashi , Furukawa Hiroyuki
Published: November 2010

In this paper, we use the numerical and empirical approaches and investigate the flow around a finite size disk in a finite size outer cylindrical casing. The disk is located at the center of the stationary casing and it is supported by a driving shaft through the disk and the casing. The disk rotates with the driving shaft. Five sizes of disks with different thicknesses and radii are used. The main purpose of this paper is to estimate the effect of the radial gaps on the entire flows. The combination of the thickness of the disk with smaller radius and the inner side of the casing with larger radius forms Taylor–Couette-like vortex flow in the radial gap. The supercritical instability makes the unsteady wavy vortex flow around the disk rim. When the axial gap between the disk surface and the end-wall of the casing is wide, the unsteady wavy flow is convected along the end-wall of the casing and it makes spiral rolls with negative front angles. When the axial gap is narrower and the Reynolds number is small, the instabilities are confined in the radial gap, and a beadlike flow appears around the disk rim. At higher Reynolds number, the turbulent spirals and the mixed spirals with positive and negative front angles are predicted. It is also shown that the phase velocity of the spiral is about or above the half of the velocity of the rotating disk.
Melting-solidification transition of Zn nanoparticles embedded in SiO2: Observation by synchrotron x-ray and ultraviolet-visible-near-infrared light
Authors: Amekura H. , Tanaka M. , Katsuya Y. , Yoshikawa H. , Ohnuma M. , Matsushita Y. , Kobayashi K. , Kishimoto N.
Published: November 2010

Melting-solidification transition of Zn nanoparticles (NPs) with the mean diameter of 11.5 nm, embedded in silica glass, was investigated by glancing incident x-ray diffraction (GIXRD) at high temperatures using synchrotron radiation (SR). With increasing temperature, 101Zn diffraction peak gradually decreases up to ∼360 °C and then steeply decreases. This is due to the melting of Zn NPs, which completes around 420 °C. With decreasing temperature, the solidification of the NPs begins around ∼310 °C. The temperature hysteresis with a width of ∼110 °C was observed. With temperature, the diffraction angle shows a shift without hysteresis, which is ascribed to thermal expansion of Zn NP lattice. Thermal expansion coefficient of Zn NPs was determined as 24.4×10−6 K−1 along the ⟨101⟩ direction. Optical absorption spectroscopy shows a broad ultraviolet (UV) peak which was observed at even higher temperatures than the melting temperature but shifts to the low-energy side with the melting. The energy shift in the UV peak also shows the temperature hysteresis which resembles with the melting-solidification hysteresis recorded by SR-GIXRD. The melting-solidification transition is also detectable by the optical absorption spectroscopy in the UV-visible-near-infrared region.
High resolution NMR study of T1 magnetic relaxation dispersion. II. Influence of spin-spin couplings on the longitudinal spin relaxation dispersion in multispin systems
Authors: Korchak Sergey , Ivanov Konstantin , Yurkovskaya Alexandra , Vieth Hans-Martin
Published: November 2010

Effects of scalar spin-spin interactions on the nuclear magnetic relaxation dispersion (NMRD) of coupled multispin systems were analyzed. Taking spin systems of increasing complexity we demonstrated pronounced influence of the intramolecular spin-spin couplings on the NMRD of protons. First, at low magnetic fields where there is strong coupling of spins the apparent relaxation times of the coupled spins become equal. Second, there are new features, which appear at the positions of the nuclear spin level anticrossings. Finally, in coupled spin systems there can be a coherent contribution to the relaxation kinetics present at low magnetic fields. All these peculiarities caused by spin-spin interactions are superimposed on the features in NMRD, which are conditioned by changes of the motional regime. Neglecting the effects of couplings may lead to misinterpretation of the NMRD curves and significant errors in determining the correlation times of molecular motion. Experimental results presented are in good agreement with theoretical calculations.
Beam aperture modifier and beam deflector using gradient-index photonic crystals
Authors: Lu Mengqian , Juluri Bala Krishna , Lin Sz-Chin Steven , Kiraly Brian , Gao Tieyu , Huang Tony Jun
Published: November 2010

We designed and simulated a beam aperture modifier and a beam deflector using two-dimensional parabolic gradient-index (GRIN) photonic crystals (PCs). The GRIN PCs are composed of dielectric columns with graded radii along the direction transverse to propagation. Both finite-difference time-domain methods and gradient optics analytical solutions were used to characterize the change in beam width and propagation direction. Multifunctional GRIN PCs combining both beam aperture modification and beam deflection were also designed and simulated. These GRIN PC based designs can be used as optical connectors and bidirectional waveguide couplers in applications such as miniaturized photonic integrated circuits.
Simulation of AlGaN/GaN high-electron-mobility transistor gauge factor based on two-dimensional electron gas density and electron mobility
Authors: Chu Min , Koehler Andrew D. , Gupta Amit , Nishida Toshikazu , Thompson Scott E.
Published: November 2010

The gauge factor of AlGaN/GaN high-electron-mobility transistor was determined theoretically, considering the effect of stress on the two-dimensional electron gas (2DEG) sheet carrier density and electron mobility. Differences in the spontaneous and piezoelectric polarization between the AlGaN and GaN layers, with and without external mechanical stress, were investigated to calculate the stress-altered 2DEG density. Strain was incorporated into a sp3d5–sp3 empirical tight-binding model to obtain the change in electron effective masses under biaxial and uniaxial stress. The simulated longitudinal gauge factor (−7.9±5.2) is consistent with experimental results (−2.4±0.5) obtained from measurements eliminating parasitic charge trapping effects through continuous subbandgap optical excitation.
An atomic-level study of material ablation and spallation in ultrafast laser processing of gold films
Authors: Gan Yong , Chen J. K.
Published: November 2010

Ablation and spallation of gold thin films by an ultrashort laser pulse are simulated by using an integrated two-temperature model and molecular dynamics method with inclusion of the hot electron blast force. The simulation results show that the ultrafast laser-induced nonthermal ablation and spallation both are essentially due to dynamic tensile stress that exceeds the local material strength. It is also demonstrated that a simultaneous use of femtosecond and picosecond laser pulses could induce spallation without causing undesired front-side damage to the film. This may be suited to peel an ultrathin film (1 μm in thickness or less) from its substrate or to improve the material removal rate of precise laser processing.
Hydrogen released from bulk ZnO single crystals investigated by time-of-flight electron-stimulated desorption
Authors: Dierre Benjamin , Yuan Xiaoli , Ueda Kazuyuki , Sekiguchi Takashi
Published: November 2010

Electron beam (e-beam) irradiation effects on ZnO single crystals have been investigated by using time-of-flight electron-stimulated desorption (TOF-ESD). The samples were irradiated by using a continuous 0.5 or 1.5 keV e-beam, while the TOF-ESD spectra were taken by using a pulsed 0.5 keV e-beam. For both the O-terminated and Zn-terminated surfaces, the major desorption is H+ desorption. The main trend of H+ desorption intensity and evolution as a function of irradiation time is similar for both faces. The H+ peak is much higher after 1.5 keV irradiation than after 0.5 keV irradiation. The intensity of the H+ peak decreases exponentially as a function of irradiation time and partially recovers after the irradiation is stopped. These observations suggest that the main contribution of the H+ desorption is hydrogen released from the dissociation of H-related defects and complexes in the bulk region of the ZnO by e-beam irradiation. This finding can be used to explain the reported ultraviolet degradation of ZnO single crystals under electron irradiation observed by cathodoluminescence. The surfaces play a lesser role for the H+ desorption, as there are differences of the decreasing rate between the two faces and additionally the intensity of the H+ peak for both the unclean O-face and Zn-facesis smaller than that for clean faces. While the H+ desorption is mainly dominated by the bulk region, O+ desorption is more influenced by the surfaces. There are two kinds of O+ desorbed from ZnO having 13.0 μs TOF and 14.2 μs TOF. The O+ desorption depends on the surface polarity, the surface conditions and the energy used for irradiation.
Inversed tunneling magnetoresistance in hybrid FePt/Fe3O4 core/shell nanoparticles systems
Authors: Zhang Yunpeng , Xing Hui , Poudyal Narayan , Nandwana Vikas , Rong Chuan-bing , Yan Shi-shen , Zeng Hao , Liu J. P.
Published: November 2010

Magnetotransport studies were performed on hybrid FePt/Fe3O4 core/shell nanoparticle systems. The linear relationship of LnR versus T−1/2 with and without a magnetic field confirms the physical picture of thermally assisted interparticle tunneling. A sign inversion of tunneling magnetoresistance (TMR) from negative to positive with decreasing temperature was observed. In the high temperature region, the core/shell nanoparticles show negative TMR similar to that of Fe3O4 nanoparticles. The magnitude of the TMR in the FePt/Fe3O4 core/shell nanoparticle systems is smaller than that in Fe3O4 nanoparticle systems, likely due to lower spin polarization of conducting electrons in FePt. However the MR becomes positive in the low temperature region. We propose that this behavior originates from the resonance tunneling between the FePt cores via the defect states near the Fermi level in the Fe3O4 shells which dominates the magnetotransport of the FePt/Fe3O4 nanoparticle system at low temperatures.
Effects of ionic liquid electrode on pulse discharge plasmas in the wide range of gas pressures
Authors: Chen Qiang , Kaneko Toshiro , Hatakeyama Rikizo
Published: November 2010

Gas–liquid interfacial pulse discharge plasmas are generated in the wide range of gas pressures, where an ionic liquid is used as the liquid electrode. By analyzing the characteristics of discharge voltage and current, the discharge mechanisms at low and high pressures are found to be dominated by secondary electron emission and first Townsend ionization, respectively. Therefore, the discharge properties at low and high pressures are mainly determined by the cathode material and the discharge gas type, respectively. Furthermore, the plasma properties are investigated by a double Langmuir probe. The density of the positive pulse plasma is found to be much smaller than that of the negative pulse plasma, although the discharge voltage and current of the negative and positive pulse plasmas are of the same order of magnitude. The positive pulse discharge plasma is considered to quickly diffuse onto the chamber wall from the radially central region due to its high plasma potential compared with that in the peripheral region.
Morphology and strain of self-assembled semipolar GaN quantum dots in (112¯2) AlN
Authors: Dimitrakopulos G. P. , Kalesaki E. , Kioseoglou J. , Kehagias Th. , Lotsari A. , Lahourcade L. , Monroy E. , Häusler I. , Kirmse H. , Neumann W. , Jurczak G. , Young T. D. , Dłużewski P. , Komninou Ph. , Karakostas Th.
Published: November 2010

GaN quantum dots (QDs) grown in semipolar (112¯2) AlN by plasma-assisted molecular-beam epitaxy were studied by transmission electron microscopy (TEM) and scanning transmission electron microscopy techniques. The embedded (112¯2)-grown QDs exhibited pyramidal or truncated-pyramidal morphology consistent with the symmetry of the nucleating plane, and were delimited by nonpolar and semipolar nanofacets. It was also found that, in addition to the (112¯2) surface, QDs nucleated at depressions comprising {101¯1} facets. This was justified by ab initio density functional theory calculations showing that such GaN/AlN facets are of lower energy compared to (112¯2). Based on quantitative high-resolution TEM strain measurements, the three-dimensional QD strain state was analyzed using finite-element simulations. The internal electrostatic field was then estimated, showing small potential drop along the growth direction, and limited localization at most QD interfaces.
Organic light emitting diodes using NaCl:N,N′-bis(naphthalene-1-yl)-N,N′-bis(phenyl)benzidine composite as a hole injection buffer layer
Authors: Kim Jeongho , Kim Myungseop , Won Kim Jeong , Yi Yeonjin , Kang Heon
Published: November 2010

Composite buffer layers of N,N′-bis(naphthalene-1-yl)-N,N′-bis(phenyl)benzidine (NPB) and NaCl at the anode/organic interface were found to be very effective on the hole injection enhancement from an indium tin oxide anode to the hole-transport layer (HTL) of NPB. Two maxima of significant current injection with respect to compositional variation were observed, implying multiple injection mechanisms of the tunneling effect and other interfacial effects. From a longer operation lifetime, the enhanced device stability was also confirmed as compared with a standard device with copper phthalocyanine as the hole injection layer. Those results are partly attributed to the better mechanical contact between anode and HTL via the composite buffer, observed from atomic force microscopy measurement.
Chaotic dephasing in a double-slit scattering experiment
Authors: Levnajić Zoran , Prosen Tomaž
Published: November 2010

We design a computational experiment in which a quantum particle tunnels into a billiard of variable shape and scatters out of it through a double-slit opening on the billiard’s base. The interference patterns produced by the scattered probability currents for a range of energies are investigated in relation to the billiard’s geometry which is connected to its classical integrability. Four billiards with hierarchical integrability levels are considered: integrable, pseudointegrable, weak-mixing, and strongly chaotic. In agreement with the earlier result by Casati and Prosen [Phys. Rev. A 72, 032111 (2005)], we find the billiard’s integrability to have a crucial influence on the properties of the interference patterns. In the integrable case, most experiment outcomes are found to be consistent with the constructive interference occurring in the usual double-slit experiment. In contrast to this, nonintegrable billiards typically display asymmetric interference patterns of smaller visibility characterized by weakly correlated wave function values at the two slits. Our findings indicate an intrinsic connection between the classical integrability and the quantum dephasing, which is responsible for the destruction of interference.
Invited Article: Electric solar wind sail: Toward test missions
Authors: Janhunen P. , Toivanen P. K. , Polkko J. , Merikallio S. , Salminen P. , Haeggström E. , Seppänen H. , Kurppa R. , Ukkonen J. , Kiprich S. , Thornell G. , Kratz H. , Richter L. , Krömer O. , Rosta R. , Noorma M. , Envall J. , Lätt S. , Mengali G. , Quarta A. A. , Koivisto H. , Tarvainen O. , Kalvas T. , Kauppinen J. , Nuottajärvi A. , Obraztsov A.
Published: November 2010

The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations.
Rewiring dynamical networks with prescribed degree distribution for enhancing synchronizability
Authors: Dadashi Majid , Barjasteh Iman , Jalili Mahdi
Published: November 2010

In this paper, we present an algorithm for enhancing synchronizability of dynamical networks with prescribed degree distribution. The algorithm takes an unweighted and undirected network as input and outputs a network with the same node-degree distribution and enhanced synchronization properties. The rewirings are based on the properties of the Laplacian of the connection graph, i.e., the eigenvectors corresponding to the second smallest and the largest eigenvalues of the Laplacian. A term proportional to the eigenvectors is adopted to choose potential edges for rewiring, provided that the node-degree distribution is preserved. The algorithm can be implemented on networks of any sizes as long as their eigenvalues and eigenvectors can be calculated with standard algorithms. The effectiveness of the proposed algorithm in enhancing the network synchronizability is revealed by numerical simulation on a number of sample networks including scale-free, Watts–Strogatz, and Erdős–Rényi graphs. Furthermore, a number of network’s structural parameters such as node betweenness centrality, edge betweenness centrality, average path length, clustering coefficient, and degree assortativity are tracked as a function of optimization steps.
Rectifying performance of D-π-A molecules based on cyanovinyl aniline derivatives
Authors: Pan J. B. , Zhang Z. H. , Deng X. Q. , Qiu M. , Guo C.
Published: November 2010

Using the first-principles method, we investigate rectifying performances of D-π-A molecules based on cyanovinyl aniline derivatives. The calculated results show that different functional groups can change the location of molecular orbitals and thus change the rectifying properties of molecules. Interestingly, we find that although the electronic structure for our studied systems is in agreement with that proposed originally by Aviram and Ratner [Chem. Phys. Lett. 29, 277 (1974)], the rectifying direction is opposite from it due to the asymmetric shift of molecular levels under biases of different polarities. Only for model (M4), it shows a forward rectifying performance under larger bias.
Intersubband photoluminescence in InAs quantum wells
Authors: Kaspi R. , Tilton M. L. , Dente G. C. , Barresi R. , Yang C. , Ongstad A. P.
Published: November 2010

We conduct a study of photoluminescence in a series of InAs quantum wells with asymmetric barriers that are designed to generate emission from intersubband transitions near 4 μm wavelength. The results show that optical pumping of the barrier layers can be used to transfer carriers into the upper electron state in the InAs wells to produce photoluminescence.
Photoreflectance analysis of a GaInP/GaInAs/Ge multijunction solar cell
Authors: Cánovas E. , Fuertes Marrón D. , Martí A. , Luque A. , Bett A. W. , Dimroth F. , Philipps S. P.
Published: November 2010

We have analyzed the photoreflectance spectra of a GaInP/GaInAs/Ge triple junction solar cell. The spectra reveal signatures from the window layer and middle and top subcells included in the stack. Additional contributions from the multilayer buffer introduced between the mismatched bottom and middle cells have been detected. Franz–Keldysh oscillations (FKOs) dominate the spectra above the fundamental bandgaps of the GaInP and GaInAs absorbers. From the FKO analysis, we have estimated the dominant electric fields within each subcell. In light of these results, photoreflectance is proposed as a useful diagnostic tool for quality assessment of multijunction structures prior to completion of the device or at earlier stages during its processing.
Photoconductive gain in patterned nanopillar photodetector arrays
Authors: Senanayake Pradeep , Lin Andrew , Mariani Giacomo , Shapiro Joshua , Tu Clayton , Scofield Adam C. , Wong Ping-Show , Liang Baolai , Huffaker Diana L.
Published: November 2010

We report on the photoconductance characteristics of indium tin oxide (ITO)-GaAs photodetectors based on patterned nanopillar (NP) arrays grown by metal-organic chemical vapor deposition. The NPs are partially encapsulated by commercially available polymer to allow transparent ITO contact to exposed NP tips. Under illumination, the NP photodetectors demonstrate photoconductive gain in both forward and reverse bias. The mechanism for photoconductive gain is attributed to both the lowering of the Schottky barrier at the ITO-GaAs interface by photogenerated holes, and also the increase in the conduction volume of the NPs under illumination.
Transcription of domain patterns in near-stoichiometric magnesium-doped lithium niobate
Authors: Zeng Hao , Kong Yongfa , Tian Tian , Chen Shaolin , Zhang Ling , Sun Tongqing , Rupp Romano , Xu Jingjun
Published: November 2010

Recently, light-induced domain reversal has been developed to a promising method for domain engineering, but the depth of reversed domain is only of several tens of microns, which greatly limits its practical applications. In this Letter, we fabricated domain patterns on the –z face of 1.0 mol % Mg doped near-stoichiometric lithium niobate with the assistance of a focal 532 nm laser, and then succeeded to transcribe these domain patterns from the –z to the +z face by applying external field without laser illumination. The transcribed domains have much larger depths, can sustain more than 100 times of the transcription cycles without large deformation, and can be erased by one transcription cycle with illumination of 532 nm laser. Finally, a light-induced ferroelectric domain transcription model was proposed.
Effect of nitrogen on the GaAs0.9−xNxSb0.1 dielectric function from the near-infrared to the ultraviolet
Authors: Ben Sedrine N. , Bouhafs C. , Harmand J. C. , Chtourou R. , Darakchieva V.
Published: November 2010

We study the effect of nitrogen on the GaAs0.9−xNxSb0.1 (x=0.00, 0.65%, 1.06%, 1.45%, and 1.90%) alloy dielectric function by spectroscopic ellipsometry in the energy range from 0.73 to 4.75 eV. The compositional dependences of the critical points energies for the GaAs0.9−xNxSb0.1 are obtained. In addition to the GaAs intrinsic transitions E1, E1+Δ1, and E0′, the nitrogen-induced Γ-point optical transitions E0 and E+, together with a third transition E#, are identified. We find that with increasing the N content, the E0 transition shifts to lower energies while the E+ and E# transitions shift to higher energies. We suggest that the origin of the E0, E+, and E# transitions may be explained by the double band anticrossing (BAC) model, consisting of a conduction BAC model and a valence BAC model.
Cortical colonisation is not an absolute requirement for phosphorus transfer to plants in arbuscular mycorrhizas formed by Scutellospora calospora in a tomato mutant: evidence from physiology and gene expression
Authors: Manjarrez Maria , Christophersen Helle M. , Smith Sally E. , Smith F. Andrew
Published: November 2010

Arbuscules in Arum-type arbuscular mycorrhizas (AM), formed intracellularly in root cortical cells, are generally believed to be the most important and defining characteristics of the symbiosis as sites for phosphorus (P) and carbon (C) exchange. We used a Pen + Coi– phenotype (penetration of epidermal and exodermal root cells but not arbuscule formation) formed in rmc (reduced mycorrhizal colonisation) mutant tomato (Lycopersicon esculentum Mill.) by Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders to determine whether the fungus is capable of transferring P from soil to plant and whether there is concurrent upregulation of AM-inducible orthophosphate (Pi) transporter gene expression in the roots. Our physiological data showed that colonisation of outer root cell layers is sufficient for P transfer from S. calospora to tomato. This transfer of P was supported by increased expression of the Pi transporter genes, LePT3 and LePT5, known to be upregulated in AM interactions. We conclude that cortical colonisation and formation of arbuscules or arbusculate hyphal coils is not an absolute prerequisite for P transfer in this symbiosis.
The role of low molecular weight ligands in nickel hyperaccumulation in Hybanthus floribundus subspecies floribundus
Authors: Kachenko Anthony G. , Singh Balwant , Bhatia Naveen
Published: November 2010

The mechanisms responsible for nickel (Ni) hyperaccumulation in Hybanthus floribundus (Lindl.) F.Muell. subspecies floribundus are obscure. In this study, organic acids and free amino acids (AAs) were quantified in 0.025 M HCl H. floribundus subsp. floribundus shoot extracts using HPLC and ultra performance liquid chromatography (UPLC). In a 20 week pot experiment, plants exposed to five levels of Ni (0–3000 mg kg–1 Ni) accumulated up to 3200 mg Ni kg–1 dry weight in shoots, and the shoot : root Ni concentration ratios were >1.4. Concentration of organic acids followed the order malic acid > citric acid > oxalic acid. Citric acid concentration significantly increased upon Ni exposure, with concentrations between 2.3- and 5.9-fold higher in Ni treated plants that in control plants. Molar ratios of Ni to citric acid ranged from 1.3 : 1 to 1.7 : 1 equivalent to >60% of the accumulated Ni. Malic acid concentration also increased upon exposure to applied Ni. However, concentrations were statistically at par across 0–3000 mg kg–1 Ni treatments, suggesting that the production of malic acid is a constitutive property of the subspecies. Total AA concentrations were stimulated upon exposure to external Ni treatment, with glutamine, alanine and aspartic acids being the predominant acids. These AAs accounted for up to 64% of the total free AA concentration in control plants and up to 75% for the 2000 mg kg–1 Ni treatment plants. These results suggest that citric acid in addition to the aforementioned AAs are synthesised in H. floribundus subsp. floribundus plants following exposure to elevated concentrations of Ni and may act as potential ligands for detoxification and possibly storage of accumulated Ni.
Hexokinase-dependent sugar signaling represses fructan exohydrolase activity in Lolium perenne
Authors: Lothier Jérémy , Lasseur Bertrand , Prud'homme Marie-Pascale , Morvan-Bertrand Annette
Published: November 2010

Defoliation of perennial ryegrass (Lolium perenne L.) by grazing animals leads to fructan mobilisation via an increase of fructan exohydrolase (FEH) activity. To highlight the regulation of fructan metabolism in perennial ryegrass, the role of sugars as signalling molecules for regulation of FEH activity after defoliation was evaluated. We used an original approach in planta by spraying stubble of defoliated plants (sugar starved plants) during 24 h with metabolisable sugars (glucose, fructose, sucrose) and sugar analogues (3-O-methylglucose, mannose, lactulose, turanose, palatinose). Metabolisable sugar (glucose, fructose, sucrose) supply following defoliation led to the repression of FEH activity increase. The supply of mannose, which is phosphorylated by hexokinase but not further metabolisable, led to the same repressive effect, whereas 3-O-methylglucose, which is not a substrate for hexokinase, had no effect. These results indicate that hexoses could be sensed by hexokinase, triggering a chain of events leading to the repression of FEH activity. By contrast, it was not possible to determine the role of sucrose as a signal since the supply of sucrose analogues (lactulose, turanose and palatinose) enhanced internal hexose content.
Dynamics of podosome stiffness revealed by atomic force microscopy
Authors: Labernadie Anna , Thibault Christophe , Vieu Christophe , Maridonneau-Parini Isabelle , Charrière Guillaume M.
Published: November 2010

Podosomes are unique cellular entities specifically found in macrophages and involved in cell–matrix interactions, matrix degradation, and 3D migration. They correspond to a core of F-actin surrounded at its base by matrix receptors. To investigate the structure/function relationships of podosomes, soft lithography, atomic force microscopy (AFM), and correlative fluorescence microscopy were used to characterize podosome physical properties in macrophages differentiated from human blood monocytes. Podosome formation was restricted to delineated areas with micropatterned fibrinogen to facilitate AFM analyses. Podosome height and stiffness were measured with great accuracy in living macrophages (578 ± 209 nm and 43.8 ± 9.3 kPa) and these physical properties were independent of the nature of the underlying matrix. In addition, time-lapse AFM revealed that podosomes harbor two types of overlapping periodic stiffness variations throughout their lifespan, which depend on F-actin and myosin II activity. This report shows that podosome biophysical properties are amenable to AFM, allowing the study of podosomes in living macrophages at nanoscale resolution and the analysis of their intimate dynamics. Such an approach opens up perspectives to better understand the mechanical functionality of podosomes under physiological and pathological contexts.
Numerical analysis of transport and binding of a target analyte and functionalized magnetic microspheres in a microfluidic immunoassay
Authors: Modak Nipu , Datta Amitava , Ganguly Ranjan
Published: November 2010

In situ binding of a target analyte on functionalized magnetic microspheres in a straight microchannel, representing a microfluidic immunoassay, is investigated numerically using an Eulerian–Lagrangian approach. Magnetic particles in the microfluidic channel are transported, using an externally imposed magnetic field, in such a manner that the particle–analyte collision is facilitated. The effects of both-ways momentum coupling between the dispersed and fluid phases on the fluid flow, particle trajectories and the analyte concentration profiles have been investigated. The particle–analyte collision is assumed to result in chemical binding between the analyte and the functionalized magnetic particles. Analyte concentration and fluid velocity fields are found to be influenced by dipole strength (P) and particle loading. In situ target analyte binding on magnetic microspheres has been quantified in terms of binding efficiency (BE), which is found to be functions of the particle loading, particle radius, dipole strength, flow velocity and the fluid viscosity. While particle loading increases, the BE also increases, but the analyte binding per particle slightly decreases. With increase in dipole strength, the BE first increases and then decreases. If the particle loading is increased, the maximum BE occurs at a higher value of P, but at a lower value of viscosity. An increase in flow velocity is found to have strong adverse effect on the BE. The study is important for the selection of optimum operating parameters so that the analyte BE of a magnetic particle-based immunoassay can be maximized.
Frequency-tunable superconducting cloaking
Authors: Li Peining , Liu Youwen , Meng Yunji , Zhu Mingjun
Published: November 2010

We have theoretically suggested a temperature-dependent superconducting cloak whose cloaking frequency can be externally controlled, since the dielectric constant of the superconductor is well tuned with the operating temperature. The results show that this tunable cloak exhibits a fine tunability in the low-temperature range 0–0.3 T
c and a fast tunability in the high-temperature range 0.3T
c–T
c, together with a large reduction in scattering (<−50 dB). It may provide a potential way to design a tunable cloak with considerable flexibility.
The Horofunction boundary of the Heisenberg Group: The Carnot-Carathéodory metric
Authors: Klein Tom , Nicas Andrew
Published: November 2010

We find the horofunction boundary of the(2n+1)(2n+1)-dimensional Heisenberg group with the Carnot-Carathéodory distance and show that it is homeomorphic to a2n2n-dimensional disk and that the Busemann points correspond to the(2n−1)(2n-1)-sphere boundary of this disk. We also show that the compactified Heisenberg group is homeomorphic to a(2n+1)(2n+1)-dimensional sphere. As an application, we find the group of isometries of the Carnot-Carathéodory distance.
Control-free calling of copy number alterations in deep-sequencing data using GC-content normalization
Authors: Boeva Valentina , Zinovyev Andrei , Bleakley Kevin , Vert Jean-Philippe , Janoueix-Lerosey Isabelle , Delattre Olivier , Barillot Emmanuel
Published: November 2010

Summary: We present a tool for control-free copy number alteration (CNA) detection using deep-sequencing data, particularly useful for cancer studies. The tool deals with two frequent problems in the analysis of cancer deep-sequencing data: absence of control sample and possible polyploidy of cancer cells. FREEC (control-FREE Copy number caller) automatically normalizes and segments copy number profiles (CNPs) and calls CNAs. If ploidy is known, FREEC assigns absolute copy number to each predicted CNA. To normalize raw CNPs, the user can provide a control dataset if available; otherwise GC content is used. We demonstrate that for Illumina single-end, mate-pair or paired-end sequencing, GC-contentr normalization provides smooth profiles that can be further segmented and analyzed in order to predict CNAs.

Availability: Source code and sample data are available at http://bioinfo-out.curie.fr/projects/freec/.

Contact:  freec@curie.fr

Supplementary information:  Supplementary data are available at Bioinformatics online.
Observable effects of Ca
2+
buffers on local Ca
2+
signals
Authors: Solovey Guillermo , Ponce Dawson Silvina
Published: November 2010

Calcium signals participate in a large variety of physiological processes. In many instances, they involve calcium entry through inositol 1,4,5-trisphosphate (IP
3
) receptors (IP
3
Rs), which are usually organized in clusters. Recent high-resolution optical experiments by Smith & Parker have provided new information on Ca
2+
release from clustered IP
3
Rs. In the present paper, we use the model recently introduced by Solovey & Ponce Dawson to determine how the distribution of the number of IP
3
Rs that become open during a localized release event may change by the presence of Ca
2+
buffers, substances that react with Ca
2+
, altering its concentration and transport properties. We then discuss how buffer properties could be extracted from the observation of local signals.
Developmental perspectives on personality: implications for ecological and evolutionary studies of individual differences
Authors: Stamps Judy A. , Groothuis Ton G. G.
Published: November 2010

Developmental processes can have major impacts on the correlations in behaviour across contexts (contextual generality) and across time (temporal consistency) that are the hallmarks of animal personality. Personality can and does change: at any given age or life stage it is contingent upon a wide range of experiential factors that occurred earlier in life, from prior to conception through adulthood. We show how developmental reaction norms that describe the effects of prior experience on a given behaviour can be used to determine whether the effects of a given experience at a given age will affect contextual generality at a later age, and to illustrate how variation within individuals in developmental plasticity leads to variation in contextual generality across individuals as a function of experience. We also show why niche-picking and niche-construction, behavioural processes which allow individuals to affect their own developmental environment, can affect the contextual generality and the temporal consistency of personality. We conclude by discussing how an appreciation of developmental processes can alert behavioural ecologists studying animal personality to critical, untested assumptions that underlie their own research programmes, and outline situations in which a developmental perspective can improve studies of the functional significance and evolution of animal personality.
Identification of novel diphenyl urea inhibitors of Mt-GuaB2 active against Mycobacterium tuberculosis
Authors: Usha Veeraraghavan , Gurcha Sudagar S. , Lovering Andrew L. , Lloyd Adrian J. , Papaemmanouil Athina , Reynolds Robert C. , Besra Gurdyal S.
Published: November 2010

In contrast with most bacteria, which harbour a single inosine monophosphate dehydrogenase (IMPDH) gene, the genomic sequence ofMycobacterium tuberculosisH37Rv predicts three genes encoding IMPDH:guaB1,guaB2andguaB3. These three genes were cloned and expressed inEscherichia colito evaluate functional IMPDH activity. Purified recombinant Mt-GuaB2, which uses inosine monophosphate as a substrate, was identified as the only active GuaB orthologue inM. tuberculosisand showed optimal activity at pH 8.5 and 37 °C. Mt-GuaB2 was inhibited significantlyin vitroby a panel of diphenyl urea-based derivatives, which were also potent anti-mycobacterial agents againstM. tuberculosisandMycobacterium smegmatis, with MICs in the range of 0.2–0.5 μg ml−1. When Mt-GuaB2 was overexpressed on a plasmidin transinM. smegmatis, a diphenyl urea analogue showed a 16-fold increase in MIC. Interestingly, when Mt-GuaB orthologues (Mt-GuaB1 and 3) were also overexpressed on a plasmidin transinM. smegmatis, they also conferred resistance, suggesting that although these Mt-GuaB orthologues were inactivein vitro, they presumably titrate the effect of the inhibitory properties of the active compoundsin vivo.
Interventions for disorder and severe intoxication in and around licensed premises, 1989–2009
Authors: Brennan Iain , Moore Simon C. , Byrne Ellie , Murphy Simon
Published: November 2010

Aims  To systematically review rigorous evaluation studies into the effectiveness of interventions in and around licensed premises that aimed to reduce severe intoxication and disorder.

Methods  A systematic search was conducted. Papers that rigorously evaluated interventions based in and around licensed premises to reduce disorder or intoxication were included.

Results  Fifteen studies were identified, three randomized controlled trials and 12 non‐randomized quasi‐experimental evaluations. Outcome measures were intoxication (n = 6), disorder (n = 6) and intoxication and disorder (n = 3). Interventions included responsible beverage service training (n = 5), server violence prevention training (n = 1), enhanced enforcement of licensing regulations (n = 1), multi‐level interventions (n = 5), licensee accords (n = 2) and a risk‐focused consultation (n = 1). Intervention effects varied, even across studies using similar interventions.

Conclusions  Server training courses that are designed to reduce disorder have some potential, although there is a lack of evidence to support their use to reduce intoxication and the evidence base is weak.