bluuebunny/crossref_metadata_2025 huggingface dataset:
Triplet correlation in sheared suspensions of Brownian particles
Authors: Yurkovetsky Yevgeny , Morris Jeffrey F.
Published: May 2006

Triplet microstructure of sheared concentrated suspensions of Brownian monodisperse spherical particles is studied by sampling realizations of a three-dimensional unit cell subject to periodic boundary conditions obtained in accelerated Stokesian dynamics simulations. Triplets are regarded as a bridge between particle pairs and many-particle clusters thought responsible for shear thickening. Triplet-correlation data for weakly sheared near-equilibrium systems display an excluded volume effect of accumulated correlation for equilateral contacting triplets. As the Péclet number increases, there is a change in the preferred contacting isosceles triplet configuration, away from the “closed” triplet where the particles lie at the vertices of an equilateral triangle and toward the fully extended rod-like linear arrangement termed the “open” triplet. This transition is most pronounced for triplets lying in the plane of shear, where the open triplets’ angular orientation with respect to the flow is very similar to that of a contacting pair. The correlation of suspension rheology to observed structure signals onset of larger clusters. An investigation of the predictive ability of Kirkwood’s superposition approximation (KSA) provides valuable insights into the relationship between the pair and triplet probability distributions and helps achieve a better and more detailed understanding of the interplay of the pair and triplet dynamics. The KSA is seen more successfully to predict the shape of isosceles contacting triplet nonequilibrium distributions in the plane of shear than for similar configurations in equilibrium hard-sphere systems; in the sheared case, the discrepancies in magnitudes of distribution peaks are attributable to two interaction effects when pair average trajectories and locations of particles change in response to real, or “hard,” and probabilistically favored (“soft”) neighboring excluded volumes and, in the case of open triplets, due to changes in the correlation of the farthest separated pair caused by the fixed presence of the particle in the middle.
Induction model for molecular electrostatics: Application to the infrared spectroscopy of CO liquid
Authors: Mankoo Parminder K. , Keyes Thomas
Published: May 2006

Far-infrared intermolecular and midinfrared vibrational spectra of CO liquid have been calculated by Fourier transforming the quantum-corrected classical dipole correlation. The time dependence of the coordinates is determined from a standard nonpolarizable force field, and the dipole is determined from the coordinates with a “spectroscopic model” proposed herein. The model includes intramolecular induction and atomic charges, polarizabilities, and permanent dipoles. A good agreement with available experimental spectra is achieved. Our results demonstrate that the use of an anharmonic potential is necessary to reproduce the experimentally observed shift upon going from gas to liquid. The behavior of the simulated dipole time correlation functions suggests that CO liquid at 80K exhibits aspects of both free rotation and solidlike caging. The proposition of some free rotation present in CO liquid supports Ewing’s experimental hypothesis.
Theory and simulation of short intense laser pulse propagation in capillary tubes with wall ablation
Authors: Veysman M. , Cros B. , Andreev N. E. , Maynard G.
Published: May 2006

The theory and simulations of short intense laser pulses propagating in capillary tubes, whose properties are changed in time and space under the action of the laser field, are presented. A hybrid approach has been used in which the dynamics of fields inside the capillary tube is described analytically, whereas the ionization, heating, and expansion of the plasma created at the inner wall of the tube under the action of the transverse energy flux are calculated by numerical simulation. This hybrid method has allowed to determine the behavior of high laser fluxes guided over large distances. The threshold value for the incident intensity at which plasma creation plays a significant role has been estimated analytically and confirmed by numerical results. For intensities above the threshold, the transmission becomes highly sensitive to the energy of the laser pulse, being minimum at the intensity level for which the electron temperature of the capillary wall slightly exceeds the Fermi level and the electron collision frequency has a maximum.
Entropy changes due to the first-order phase transition in the Gd5SixGe4−x system
Authors: Liu G. J. , Sun J. R. , Lin J. , Xie Y. W. , Zhao T. Y. , Zhang H. W. , Shen B. G.
Published: May 2006

Entropy changes due to magnetostructrual phase transition in Gd5SixGe4−x intermetallics have been studied based on a systematic analysis of experiment data and mean-field theory calculations. It is found that the magnetic and lattice entropy changes have the same sign. Further analysis indicates that the main entropy change (∼60%–∼80%) comes from the field-induced change of the magnetic order, while the rest arise from the entropy difference of the two crystallographic modifications joined by the structural transition, probably due to the variation of the lattice vibration mode. The present work reveals the importance of lattice entropy for a system experiencing a first-order transition.
Backward coupling waveguide coupler using left-handed material
Authors: Yuan Yu , Ran Lixin , Chen Hongsheng , Huangfu Jiangtao , Grzegorczyk Tomasz M. , Kong Jin Au
Published: May 2006

An X-band microwave waveguide coupler partially filled with a left-handed material is realized and measured. The electromagnetic wave propagates in the primary branch of the coupler which is filled with the left-handed material and is backward edge coupled into the secondary waveguide, filled with a right-handed material. Near the interface between the left-handed and the right-handed materials, the Poynting vectors have opposite directions, which yields a backward coupling. Such coupler is designed, fabricated, and the backward coupling effect is indeed measured.
Thomson-scattering measurements of high electron temperature hohlraum plasmas for laser-plasma interaction studies
Authors: Froula D. H. , Ross J. S. , Divol L. , Meezan N. , MacKinnon A. J. , Wallace R. , Glenzer S. H.
Published: May 2006

Accurate measurements of the plasma conditions in laser-produced high-temperature plasmas have been achieved using the recently activated 4ω Thomson-scattering diagnostic at the Omega Laser Facility, Soures et al., Laser Part. Beams 11 (1993). These diagnostic measurements were performed in a new hohlraum target platform that will be used to study laser-plasma interaction in a strongly damped regime comparable to those occurring in indirect drive inertial confinement fusion plasmas. The Thomson-scattering spectra show the collective ion-acoustic features that fit the theory for two ion species plasmas allowing us to accurately and independently determine both the electron and ion temperatures. The electron temperature was found to range from 2to4keV as the total heater beam energy deposited into the hohlraum was increased from 8to17kJ. The results are compared to 2D hydrodynamic simulations using flux limited diffusion and nonlocal heat flux models. The target platform presented provides a novel test bed to investigate laser-plasma interaction physics in the strongly damped backscatter regime.
The excitation of extraordinary and ordinary waves in a magnetized plasma medium by a rotating electron beam
Authors: Shokri B. , Khorashadizadeh S. M.
Published: May 2006

The possibility of the excitation of extraordinary and ordinary cyclotron waves by interaction of a rotating electron beam propagating parallel to the external magnetic field with a cold plasma medium is investigated. By obtaining the growth rates, the influence of dissipation on the development of extraordinary and ordinary cyclotron waves are studied. By comparing the development of the cyclotron instability with the dissipative instability in extraordinary and ordinary cyclotron waves excitation in the beam-plasma system, the dependency of the growth rates of these instabilities on the physical parameters is discussed.
Dynamics of electromagnetic solitons in a relativistic plasma
Authors: Mančić Ana , Hadžievski Ljupčo , Škorić Miloš M.
Published: May 2006

Dynamical features of one-dimensional electromagnetic solitons formed in a relativistic interaction of a linearly polarized laser light with underdense cold plasma are investigated. The relativistic Lorentz force in an intense laser light pushes electrons into longitudinal motion, generating coupled longitudinal-transverse waves. In a weakly relativistic approximation these modes are well described by the generalized nonlinear Schrödinger type of equation, with two extra nonlocal terms. Here, an original analytical solution for a moving electromagnetic soliton is derived in an implicit form. For an isolated soliton, our analysis shows that the motion downshifts the soliton eigenfrequency and decreases its amplitude. The effect of the soliton velocity on the stability is analytically predicted and checked numerically. Results show shifting of the stability region toward larger amplitudes in comparison to the standing soliton case. Rich dynamics with examples of (un)stable soliton propagation and breather creation and formation of unstable cusp-type structures is exposed numerically.
Analytical study of spheroidal dust grains in plasma
Authors: Zahed H. , Mahmoodi J. , Sobhanian S.
Published: May 2006

Using the modified spheroidal equations, the potential of a spheroidal conducting grain, floated in a plasma, is calculated. The electric field and capacitance for both prolate and oblate spheroidal grains are investigated. The solutions, obtained up to the second-order approximation, show that the plasma screening causes the equipotential surfaces around the grain to be more elongated or flattened than the potential spheroids of the Laplace equation. This leads to the variation of the plasma concentration around the grain.
Modulated electrostatic modes in pair plasmas: Modulational stability profile and envelope excitations
Authors: Kourakis I. , Esfandyari-Kalejahi A. , Mehdipoor M. , Shukla P. K.
Published: May 2006

A pair plasma consisting of two types of ions, possessing equal masses and opposite charges, is considered. The nonlinear propagation of modulated electrostatic wave packets is studied by employing a two-fluid plasma model. Considering propagation parallel to the external magnetic field, two distinct electrostatic modes are obtained, namely a quasiacoustic lower moddfe and a Langmuir-like, as optic-type upper one, in agreement with experimental observations and theoretical predictions. Considering small yet weakly nonlinear deviations from equilibrium, and adopting a multiple-scale technique, the basic set of model equations is reduced to a nonlinear Schrödinger equation for the slowly varying electric field perturbation amplitude. The analysis reveals that the lower (acoustic) mode is stable and may propagate in the form of a dark-type envelope soliton (a void) modulating a carrier wave packet, while the upper linear mode is intrinsically unstable, and may favor the formation of bright-type envelope soliton (pulse) modulated wave packets. These results are relevant to recent observations of electrostatic waves in pair-ion (fullerene) plasmas, and also with respect to electron-positron plasma emission in pulsar magnetospheres.
ZnO thin-film transistors with polycrystalline (Ba,Sr)TiO3 gate insulators
Authors: Siddiqui J. , Cagin E. , Chen D. , Phillips J. D.
Published: May 2006

The electrical characteristics of ZnO thin-film transistors with high-k (Ba,Sr)TiO3 gate dielectrics are presented. The ZnO and (Ba,Sr)TiO3 thin films were deposited on Pt, exhibiting polycrystalline characteristics. The thin-film devices demonstrated transistor behavior over the range of 0–10V with a stable threshold voltage of approximately 1.2V. The field effect mobility, subthreshold slope, and on/off ratio were measured to be 2.3cm2V−1s−1, 0.25V∕decade, and 1.5×108, respectively. The measured transistor performance characteristics suggest that ZnO∕(Ba,Sr)TiO3 structures are well suited for both polycrystalline thin-film transistors for display applications and future higher performance transistors based on single crystal ZnO.
p
-type electrical conduction in α-AgGaO2 delafossite thin films
Authors: Vanaja K. A. , Ajimsha R. S. , Asha A. S. , Jayaraj M. K.
Published: May 2006

Thin films of delafossites of α-AgGaO2 were prepared on α-Al2O3 (0001) and on Si (100) single crystal substrates by pulsed laser deposition. The films have a band gap of 4.12eV and a transparency of more than 50% in the visible region. The electrical conductivity at 300K was 3.2×10−4Scm−1. The positive sign of Seebeck coefficient (+70μVK−1) demonstrated the p-type conduction in the films. Transparent p-n heterojunctions on a glass substrate having a structure glass/ITO∕n-ZnO∕p-AgGaO2 were fabricated. The ratio of forward to reverse current was more than 100 in the range of −2to+2V.
Wurtzite GaN nanocolumns grown on Si(001) by molecular beam epitaxy
Authors: Cerutti L. , Ristić J. , Fernández-Garrido S. , Calleja E. , Trampert A. , Ploog K. H. , Lazic S. , Calleja J. M.
Published: May 2006

Wurtzite single crystal GaN nanocolumns were grown by plasma-assisted molecular beam epitaxy on bare Si(001) substrates. Nanocolumns with diameters in the range of 20–40nm have no traces of extended defects and they grow aligned along the [0001] direction. Photoluminescence measurements in nanocolumns evidence a very high crystal quality in terms of intense and narrow excitonic emissions. Raman scattering data show that the nanocolumns are strain-free. These results open the way to an efficient integration of optoelectronic devices with the complementary metal oxide semiconductor technology.
Order in vertically aligned carbon nanotube arrays
Authors: Wang H. , Xu Z. , Eres G.
Published: May 2006

We report the direct measurements on the bulk morphology of vertically aligned multiwalled carbon nanotube (CNT) arrays using small angle neutron scattering (SANS). SANS measurements at different heights of CNT arrays corresponding to different stages of the growth reveal increasing alignment order along the thickness and two distinctly different CNT morphologies. The observations suggest that the evolution of the macroscopic CNT morphologies be driven by competing collective growth and spatial constraints.
Self-expanded microcapillary positive column for highly efficient vacuum ultraviolet sources
Authors: Lee Tae Il , Park Ki Wan , Hwang Hyeon Seok , Jegal Jong Pil , Baik Hong Koo
Published: May 2006

We adopted the self-expanded microcapillary positive column from single microhollow cathode discharge as a high efficient vacuum ultraviolet (vuv) sources, employing one power supply circuit with a resistor for easily starting without an additional power supplier and investigated their electrical characteristics and the vuv radiant efficiency, varying the input power. The electrical measurements showed that the discharge passed through two distinct stages: the microhollow cathode discharges stage and the self-expanded microcapillary positive column stage. As a result, the vuv radiant efficiency of the self-expanded microcapillary positive column is about 17 times as high as that of the microhollow cathode discharges at the input power 1.2W.
Quantum logic processor: Implementation with electronic Mach-Zehnder interferometer
Authors: Sarkar Angik , Bhattacharyya T. K. , Patwardhan Ajay
Published: May 2006

An approach for implementation of quantum logic in electronic Mach-Zehnder interferometer (MZI) has been described in this letter. All single qubit gates can be achieved by electron spin manipulation using Rashba spin-orbit coupling. Double qubit gates can also be implemented using the orbital degree of freedom of the electron. The MZI can be realized with intertwined ballistic nanowires. Spin injection and detection in the system can be done by a mesoscopic Stern-Gerlach apparatus. The system can be coupled in an array to form the quantum logic processor.
Magnetic depth profiles from resonant soft x-ray scattering: Application to Dy thin films
Authors: Ott H. , Schüβler-Langeheine C. , Schierle E. , Kaindl G. , Weschke E.
Published: May 2006

We employ the strong variation of the photon penetration depth across an electronic resonance in soft x-ray scattering for a depth resolved study of an antiferromagnetic (AFM) thin film. We directly observed the development of the helical AFM structure in thin Dy(001) films on W(110) across the temperature-induced phase transition from ferromagnetic to helical AFM order.
Purely gain-coupled distributed feedback laser via a bright optical lattice
Authors: Sadeghi S. M. , Li X. , Huang W.-P. , Li W.
Published: May 2006

We utilize degeneracy of Bragg resonance and the intersubband transitions in a quantum well bright optical lattice to propose a coherently induced purely gain-coupled distributed feedback laser. The optical lattice is generated via formation of periodic regions of resonant intersubband gain without inversion in the absence of any refractive index perturbation using a control laser field. We show that longitudinal mode intensity profile and standing wave effects of such an intrinsically single-mode intersubband laser can be coherently controlled. These features allow immunity against spatial hole burning and lasing when modal loss is higher than modal gain.
Ni
2
Si
nanowires of extraordinarily low resistivity
Authors: Zhang Z. , Lu J. , Hellström P.-E. , Östling M. , Zhang S.-L.
Published: May 2006

Ultralong, polycrystalline Ni2Si nanowires are fabricated by combining sidewall transfer lithography with self-aligned silicidation. Upon formation at 500°C, the nanowires that are 400μm long with a rectangular cross section of 37.5 by 25.3nm are characterized by a resistivity of 25±1μΩcm which is similar to the value for Ni2Si thin films. Further annealing at 800°C results in an extraordinarily low wire resistivity of 10μΩcm. Such a drastic decrease in resistivity is attributed to a significant grain growth and a low density of defects in the nanowires.
New stable multiply charged negative atomic ions in linearly polarized superintense laser fields
Authors: Wei Qi , Kais Sabre , Moiseyev Nimrod
Published: May 2006

Singly charged negative atomic ions exist in the gas phase and are of fundamental importance in atomic and molecular physics. However, theoretical calculations and experimental results clearly exclude the existence of any stable doubly-negatively-charged atomic ion in the gas phase, only one electron can be added to a free atom in the gas phase. In this report, using the high-frequency Floquet theory, we predict that in a linear superintense laser field one can stabilize multiply charged negative atomic ions in the gas phase. We present self-consistent field calculations for the linear superintense laser fields needed to bind extra one and two electrons to form He−, He2−, and Li2−, with detachment energies dependent on the laser intensity and maximal values of 1.2, 0.12, and 0.13eV, respectively. The fields and frequencies needed for binding extra electrons are within experimental reach. This method of stabilization is general and can be used to predict stability of larger multiply charged negative atomic ions.
Metabolic regulation of in vitro-produced bovine embryos. II. Effects of phenazine ethosulfate, sodium azide and 2,4-dinitrophenol during post-compaction development on glucose metabolism and lipid accumulation
Authors: De La Torre-Sanchez Jose Fernando , Gardner David K. , Preis Kimberly , Gibbons John , Seidel George E.
Published: May 2006

The objective was to compare effects of three metabolic regulators on development of post-compaction bovine embryos. In-vitro-produced 8- to 16-cell embryos were allocated to treatments for 72 h in G2.2 medium as follows: 0.3 µm phenazine ethosulfate (PES); 27 µm sodium azide (NaN3); 30 µm 2,4-dinitrophenol (DNP); and control, no regulator. Treatments responded similarly for blastocyst rates and embryo quality responses (P > 0.1). The PES treatment resulted in higher glucose metabolism than the NaN3 treatment (18.5 v. 14.5 pmol per embryo per h, P < 0.05), and both did not differ from DNP or the control. The PES treatment tended to result in more flux of glucose through the pentose phosphate pathway (PPP) than the control (50.5 v. 21.5%, P < 0.11). The NaN3 treatment caused more glucose uptake than the PES treatment (38.9 v. 13.1 pmol per embryo per h, P < 0.01), but neither differed from the control or DNP treatment (P > 0.1). Glycolysis for the PES treatment was 187%, which was higher than any of the other groups (88–94%; P < 0.01). There were fewer medium + large lipid granules in the cytoplasm of PES-treated embryos than any other group, including the in vitro control (P < 0.01). However, in vivo control embryos had still fewer large and medium-sized lipid granules (P < 0.01) than the PES treatment. Developmental competence to Day 14 after embryo transfer was similar among treatments. The PES treatment increased glucose metabolism, tended to increase the PPP flux of glucose and clearly reduced accumulation of lipids in embryos produced in the chemically defined media used. Use of PES in culture media may be a promising approach to improving in vitro production of embryos.
Nuclear magnetic resonance spectroscopy of bovine ovarian follicular fluid at four selected times of the oestrous cycle
Authors: Sarty Gordon E. , Kendall Edward J. , Adams Gregg P. , Pierson Roger A.
Published: May 2006

The objective of the study was to determine if nuclear magnetic resonance (NMR) spectral features of ovarian follicular fluid were correlated with the physiological status of follicles so that we could assess the feasibility of using NMR spectroscopy during assisted reproduction therapy. Thirty-five sexually mature, nullparious heifers were monitored by transrectal ultrasonography to assess their follicle wave status during the oestrous cycle. Ovariectomies were performed on Day 3 of wave 1 (D3W1, n = 10), Day 6 of wave 1 (D6W1, n = 9), Day 1 of wave 2 (D1W2, n = 9), or in the immediate preovulatory period of at least 17 days after ovulation (D≥17, n = 9). Follicle status was determined to be dominant or subordinate. Follicular fluid was extracted from the follicles and NMR spectra were collected. Principal components were extracted from ratios of line amplitudes and tested for effects of follicle status (dominant v. subordinate) and cycle time point (D1W3, D1W6, D1W2 and D≥17) using multivariate analysis of variance. For most line ratio combinations, main effects of status, time point and their interaction were found (P < 0.05). We concluded that NMR spectra may be used for the determination of ovarian follicle physiological status.
Alternative splicing in concert with protein intrinsic disorder enables increased functional diversity in multicellular organisms
Authors: Romero Pedro R. , Zaidi Saima , Fang Ya Yin , Uversky Vladimir N. , Radivojac Predrag , Oldfield Christopher J. , Cortese Marc S. , Sickmeier Megan , LeGall Tanguy , Obradovic Zoran , Dunker A. Keith
Published: May 2006

Alternative splicing of pre-mRNA generates two or more protein isoforms from a single gene, thereby contributing to protein diversity. Despite intensive efforts, an understanding of the protein structure–function implications of alternative splicing is still lacking. Intrinsic disorder, which is a lack of equilibrium 3D structure under physiological conditions, may provide this understanding. Intrinsic disorder is a common phenomenon, particularly in multicellular eukaryotes, and is responsible for important protein functions including regulation and signaling. We hypothesize that polypeptide segments affected by alternative splicing are most often intrinsically disordered such that alternative splicing enables functional and regulatory diversity while avoiding structural complications. We analyzed a set of 46 differentially spliced genes encoding experimentally characterized human proteins containing both structured and intrinsically disordered amino acid segments. We show that 81% of 75 alternatively spliced fragments in these proteins were associated with fully (57%) or partially (24%) disordered protein regions. Regions affected by alternative splicing were significantly biased toward encoding disordered residues, with a vanishingly small
P
value. A larger data set composed of 558 SwissProt proteins with known isoforms produced by 1,266 alternatively spliced fragments was characterized by applying the
pondr vsl1
disorder predictor. Results from prediction data are consistent with those obtained from experimental data, further supporting the proposed hypothesis. Associating alternative splicing with protein disorder enables the time- and tissue-specific modulation of protein function needed for cell differentiation and the evolution of multicellular organisms.
The RNA-binding protein Musashi is required intrinsically to maintain stem cell identity
Authors: Siddall Nicole A. , McLaughlin Eileen A. , Marriner Neisha L. , Hime Gary R.
Published: May 2006

A key goal of regenerative medicine is an understanding of the genetic factors that define the properties of stem cells. However, stem cell research in mammalian tissue has been hampered by a paucity of stem cell-specific markers. Although increasing evidence suggests that members of the Musashi (Msi) family of RNA-binding proteins play important functions in progenitor cells, it remains unclear whether there is a stem cell-autonomous requirement for Msi because of an inability to distinguish stem cells from early-lineage cells in mammalian tissues. Here, using the
Drosophila
testis as a model system for the study of stem cell regulation, we show specific evidence for a cell-autonomous requirement for Msi family proteins in regulating stem cell differentiation, leading to the identification of an RNA-binding protein required for spermatogonial stem cell maintenance. We found that loss of Msi function disrupts the balance between germ-line stem cell renewal and differentiation, resulting in the premature differentiation of germ-line stem cells. Moreover, we found that, although Msi is expressed in both somatic and germ cells, Msi function is required intrinsically in stem cells for maintenance of stem cell identity. We also discovered a requirement for Msi function in male meiosis, revealing that Msi has distinct roles at different stages of germ cell differentiation. We describe the complementary expression patterns of the murine Msi paralogues Msi1 and Msi2 during spermatogenesis, which support the idea of distinct, evolutionarily conserved roles of Msi.
Thymic output in aged mice
Authors: Hale J. Scott , Boursalian Tamar E. , Turk Gail L. , Fink Pamela J.
Published: May 2006

Using GFP to mark recent thymic emigrants (RTEs) in mice carrying a GFP transgene driven by the recombination-activating gene 2 promoter, we demonstrate that RTEs are readily detectable even in 2-year-old mice, despite the fact that the proportion of the peripheral T cell pool comprised of RTEs declines with age. Although the number of RTEs decreases after reaching a peak at 6 weeks of age, thymic output as a function of thymic size is surprisingly age-independent. The CD4:CD8 ratio of RTEs declines with age, partly because of a striking decrease in steady-state proliferation of CD4+RTEs in older mice. RTEs in aged mice undergo phenotypic maturation in the lymphoid periphery with delayed kinetics compared with young mice. RTEs from aged mice secrete less IL-2, proliferate less well, and achieve only weak expression of early-activation markers compared with more mature naïve peripheral T cells from the same mice. The proportion of GFP−cells in the CD4+and CD8+thymic compartments increases with age, partly as a result of leakiness in the aged thymus, allowing reentry of naïve peripheral T cells.
Soft-lithographic replication of 3D microstructures with closed loops
Authors: LaFratta Christopher N. , Li Linjie , Fourkas John T.
Published: May 2006

There is growing interest in lithographic technologies for creating 3D microstructures. Such techniques are generally serial in nature, prohibiting the mass production of devices. Soft-lithographic techniques show great promise for simple and rapid replication of arrays of microstructures but have heretofore not been capable of direct replication of structures with closed loops. We demonstrate that 3D microstructures created with multiphoton absorption polymerization can be replicated by using microtransfer molding to afford complex daughter structures containing closed loops. This method relieves many of the topological constraints of soft lithography, paving the way for the large-scale replication of true 3D microstructures.
Effect of zinc supplementation on in vitro copper-induced oxidation of low-density lipoproteins in healthy French subjects aged 55–70 years:the Zenith Study
Authors: Feillet-Coudray Christine , Meunier Nathalie , Bayle Dominique , Brandolini-Bunlon Marion , Andriollo-Sanchez Maud , O'Connor Jacqueline M. , Maiani Giuseppe , Roussel Anne-Marie , Mazur Andrzej , Coudray Charles
Published: May 2006

Zn has been shown to possess antioxidant properties in vitro and in vitro. As inadequate dietary Zn intake has been reported in these populations, Zn supplementation may protect against oxidative stress and thereby limit the progression of degenerative diseases in such populations. We conducted the present study to evaluate the long-term supplementation effects of two moderate doses of Zn on in vitro Cu-induced LDL oxidation in French men and women.Three groups of sixteen healthy subjects aged 55–70 years from each sex participated in this randomized double-blind, placebo-controlled study. Each group received for six months either 0, 15 or 30mg supplemental Zn per d. At the beginning and at the end of the supplementation periods, dietary intakes of Zn, Cu, Fe and vitamin E were estimated using 4d food-intake records (including the weekend) and the GENI program. Zn, Cu, Fe and vitamin E statuswere also determined. In vitro LDL oxidizability (basal conjugated diene level, maximal conjugated diene formation and lag time) and lipid parameters were also determined. Dietary intakes of Zn, Cu, Fe and vitamin E were adequate in this population. Zn supplementation significantly increased serum Zn levels but did not significantly modify Cu, Fe or vitamin E status. However, Zn supplementation had no effect on in vitro LDL oxidation parameters, nor were there any sex-related differences in in vitro LDL oxidizability. The present study showed that long-term Zn supplementation of healthy subjects aged 55–70 years had no effect on in vitro Cu-induced LDL oxidation under the study conditions.
Use of height3:waist circumference3 as an index for metabolic risk assessment?
Authors: Bosy-Westphal Anja , Danielzik Sandra , Geisler Corinna , Onur Simone , Korth Oliver , Selberg Oliver , Pfeuffer Maria , Schrezenmeir Jürgen , Müller Manfred J.
Published: May 2006

Current anthropometric indices for health risk assessment are indirect measures of total or visceral body fat mass that do not consider the inverse relationship of lean body mass to metabolic risk as well as the non-linear relationship between central obesity and insulin resistance.We examined a new anthropometric index that reflects the relationship of waist circumference (WC) as a risk factor to fat-free mass (FFM) as a protective parameter of body composition. In apopulation of 335 adults (191 females and 144 males; mean age 53 (sd 13·9) years) with ahigh prevalence of obesity (27%) and metabolic syndrome (30%) we derived FFM:WC3 from the best fit of the relationship with metabolic risk factors (plasma triacylglycerol levels and insulin resistance by homeostasis model assessment index). Because FFM is known to be proportional to the cube of height, FFM was subsequently replaced by height3 yielding height3:WC3 as an easily applicable anthropometric index. Significant inverse relationships of height3:WC3 to metabolic risk factorswere observed for both sexes. They slightly exceeded those of conventional anthropometric indicessuch as BMI, WC or WC:hip ratio in women but not in men. The exponential character of the denominator WC3 implies that at a given FFM with gradually increasing WC the increasein metabolic risk is lower than proportional. Further studies are needed to evaluate height3:WC3 as an anthropometric index for health risk assessment.
Effects of dietary lipoic acid on plasma lipid,in vivoinsulin sensitivity, metabolic response to corticosterone andin vitrolipolysis in broiler chickens
Authors: Hamano Yoshio
Published: May 2006

The present study consisted of two experiments. The first experiment was conducted to determine the effects of lipoic acid (ALA; 200mg/kg) on plasma lipids and insulin sensitivity of whole-body tissue in broilers treated with or without corticosterone (5mg/kg). Chickens received these agents from 2 to 5 weeks of age in a 2×2 factorial arrangement. Thereafter, from 39 to 42d of age, insulin sensitivity was estimated using the euglycaemic and hyperinsulinaemic clamp technique. Experiment 2 examined whether ALA supplementation for 5 weeks (400mg/kg) would alter short-chain acyl-CoA concentration in the liver andin vitrolipolysis of an adipose tissue slice, in relation to noradrenaline (10μm) supplementation. In experiment 1, ALA had no effect on the corticosterone-induced negative growth performance. ALA lowered plasma glucose level (P<0·05) and, in contrast, increased triacylglycerol level (P<0·05). These responses to ALA had, however, no interrelationship with corticosterone. The rate of glucose uptake of whole-bodyP<0·05) but was not affected by noradrenaline supplementation. This study suggests that ALA stimulates the insulin sensitivity of tissues regardless of corticosterone-dependent metabolism and that the ALA-induced fatty acid metabolism of broilers differs between the liver and adipose tissue.
Basal metabolic rate as a proxy for overnight energy expenditure: the effect of age
Authors: Wouters-Adriaens Mirjam P. E. , Westerterp Klaas R.
Published: May 2006

Recommendations for daily energy requirements use factorial calculations based on BMR. Expressing total energy requirements as a multiple of BMR is based on the assumption that BMR is equal to overnight metabolic rate (OMR). The objective of the present study was to determine if BMR is an appropriate proxy for OMR in children, young adults and elderly. Data are presented of thirty children (11 (sd 2) years), thirty young adults (25 (sd 5) years) and fifty-nine elderly(61 (sd 5) years). OMR was measured in a respiration chamber while sleep was not hindered and BMR was measured directly afterwards with a ventilated hood system under strictly controlled conditions. The mean ratio of OMR:BMR was 0·92 (sd 0·09) for children, which was significantly different from 1·00 (P<0·001), 1·00 (sd 0·07) for young adults and 1·06 (sd 0·09) for elderly whichwas also different from 1·00 (P<0·001). Foradults, BMR is an appropriate measure of OMR. In children, the use of BMR to estimate OMR wouldintroduce an overestimate and for elderly an underestimate.
Comment
Authors: Danziger Kurt
Published: May 2006

For some contributors, “indigenous psychology” seems to involve no more than the introduction of essentially technical modifications that serve to enhance the export value of psychological products imported from the West. For the majority, however, indigenous psychology seems to imply some kind of reaction against the way in which the ideal of universal psychological knowledge is commonly pursued in the major centres. Insofar as this reaction is concerned with fundamental issues, it can be seen as questioning the social and normative framework within which psychological knowledge is produced and evaluated. Certain culture‐bound interpretations of science and scientific method form an important part of this framework. Although complaints about the individualistic bias of Western psychology are common, there is a need for further exploration of the link between this brand of individualism, “Cartesian psychology,” and a certain understanding of the goals of scientific investigation in psychology. These goals, as well as the norms governing their practical pursuit, are embedded in and enforced by disciplinary structures that are now international in scope but were originally the product of quite specific historical circumstances. This imported disciplinary organization of psychological knowledge may not be appropriate at all times and everywhere. It may be particularly inappropriate where the primary task of indigenous psychology is considered to be the generation of locally appropriate knowledge. Another obstacle to the achievement of this task is constituted by the uncritical use of “culture” as an entity. A more promising approach is provided by those contributors for whom indigenous psychology means doing researchwithrather thanonindigenous people. This seems to be an important step towards escaping a tradition in which the human sources and the human beneficiaries of professional psychological knowledge have seldom been the same people.
IFNγ-dependent, spontaneous development of colorectal carcinomas in SOCS1-deficient mice
Authors: Hanada Toshikatsu , Kobayashi Takashi , Chinen Takatoshi , Saeki Kazuko , Takaki Hiromi , Koga Keiko , Minoda Yasumasa , Sanada Takahito , Yoshioka Tomoko , Mimata Hiromitsu , Kato Seiya , Yoshimura Akihiko
Published: May 2006

Approximately 20% of human cancers are estimated to develop from chronic inflammation. Recently, the NF-κB pathway was shown to play an essential role in promoting inflammation-associated cancer, but the role of the JAK/STAT pathway, another important signaling pathway of proinflammatory cytokines, remains to be investigated. Suppressor of cytokine signaling-1 (SOCS1) acts as an important physiological regulator of cytokine responses, and silencing of the SOCS1 gene by DNA methylation has been found in several human cancers. Here, we demonstrated that SOCS1-deficient mice (SOCS1−/−Tg mice), in which SOCS1 expression was restored in T and B cells on a SOCS1−/− background, spontaneously developed colorectal carcinomas carrying nuclear β-catenin accumulation and p53 mutations at 6 months of age. However, interferon (IFN)γ−/−SOCS1−/− mice and SOCS1−/−Tg mice treated with anti-IFNγ antibody did not develop such tumors. STAT3 and NF-κB activation was evident in SOCS1−/−Tg mice, but these were not sufficient for tumor development because these are also activated in IFNγ−/−SOCS1−/− mice. However, colons of SOCS1−/−Tg mice, but not IFNγ−/−SOCS1−/− mice, showed hyperactivation of STAT1, which resulted in the induction of carcinogenesis-related enzymes, cyclooxygenase-2 and inducible nitric oxide synthase. These data strongly suggest that SOCS1 is a unique antioncogene which prevents chronic inflammation-mediated carcinogenesis by regulation of the IFNγ/STAT1 pathways.
A matricial corona theorem
Authors: Trent Tavan , Zhang Xinjun
Published: May 2006

We show that a usual corona-type theorem on a space of functions automatically extends to a matrix version.
Arens-Michael enveloping algebras and analytic smash products
Authors: Pirkovskii A.
Published: May 2006

Let

g

\mathfrak {g}

be a finite-dimensional complex Lie algebra, and let

U
(

g

)

U(\mathfrak {g})

be its universal enveloping algebra. We prove that if

U
^

(

g

)

\widehat {U}(\mathfrak {g})

, the Arens-Michael envelope of

U
(

g

)

U(\mathfrak {g})

is stably flat over

U
(

g

)

U(\mathfrak {g})

(i.e., if the canonical homomorphism

U
(

g

)
→

U
^

(

g

)

U(\mathfrak {g})\to \widehat {U}(\mathfrak {g})

is a localization in the sense of Taylor (1972), then

g

\mathfrak {g}

is solvable. To this end, given a cocommutative Hopf algebra

H
H

and an

H
H

-module algebra

A
A

, we explicitly describe the Arens-Michael envelope of the smash product

A
#
H

A\# H

as an “analytic smash product” of their completions w.r.t. certain families of seminorms.
Covering a Banach space
Authors: Fonf Vladimir , Zanco Clemente
Published: May 2006

A well-known theorem by H. Corson states that if a Banach space admits a locally finite covering by bounded closed convex subsets, then it contains no infinite-dimensional reflexive subspace. We strengthen this result proving that if an infinite-dimensional Banach space admits a locally finite covering by bounded

w
w

-closed subsets, then it is

c
0

c_0

-saturated, thus answering a question posed by V. Klee concerning locally finite coverings of

l
1

l_1

spaces. Moreover, we provide information about massiveness of the set of singular points in (PC) spaces.
Super-Ergodic operators
Authors: Yahdi M.
Published: May 2006

The aim of this work is to study operators naturally connected to Ergodic operators in infinite-dimensional Banach spaces, such as Uniform-Ergodic, Cesaro-bounded and Power-bounded operators, as well as stable and superstable operators. In particular, super-Ergodic operators are introduced and shown to be strictly between Ergodic and Uniform-Ergodic operators, and that any power bounded operator is super-Ergodic in a superreflexive space. New relationships between these operators are shown, others are proven to be optimal or can be ameliorated according to structural properties of the Banach space, such as the superreflexivity or with unconditional basis.
Boundary structure of hyperbolic 3-manifolds admitting annular fillings at large distance
Authors: Lee Sangyop
Published: May 2006

We show that if a hyperbolic

3
3

-manifold

M
M

with

∂
M

\partial M

a union of tori admits two annular Dehn fillings at distance

Δ
≥
3

\Delta \ge 3

, then

M
M

is bounded by at most three tori.
On operators which commute with analytic Toeplitz operators modulo the finite rank operators
Authors: Guo Kunyu , Wang Kai
Published: May 2006

It is shown that an operator

S
S

on the Hardy space

H
2

(

D

n

)

H^2({\mathbb {D}}^n)

(or

H
2

(

B

n

)

H^2({\mathbb {B}}_n)

) commutes with all analytic Toeplitz operators modulo the finite rank operators if and only if

S
=

T
g

+
F

S=T_g+F

. Here

F
F

is a finite rank operator, and in the case

n
=
1

n=1

,

g
g

is a sum of a rational function and a bounded analytic function, and in the case

n
≥
2

n\geq 2

,

g
g

is a bounded analytic function.
The joint weight enumerators and Siegel modular forms
Authors: Choie Y. , Oura M.
Published: May 2006

The weight enumerator of a binary doubly even self-dual code is an isobaric polynomial in the two generators of the ring of invariants of a certain group of order 192. The aim of this note is to study the ring of coefficients of that polynomial, both for standard and joint weight enumerators.
Composition operators with maximal norm on weighted Bergman spaces
Authors: Carswell Brent , Hammond Christopher
Published: May 2006

We prove that any composition operator with maximal norm on one of the weighted Bergman spaces

A

α

2

A^{2}_{\alpha }

(in particular, on the space

A

2

=

A

0

2

A^{2}=A^{2}_{0}

) is induced by a disk automorphism or a map that fixes the origin. This result demonstrates a major difference between the weighted Bergman spaces and the Hardy space

H

2

H^{2}

, where every inner function induces a composition operator with maximal norm.
Extreme contractions on continuous vector-valued function spaces
Authors: Al-Halees Hasan , Fleming Richard
Published: May 2006

An old question asks whether extreme contractions on

C
(
K
)

C(K)

are necessarily nice; that is, whether the conjugate of such an operator maps extreme points of the dual ball to extreme points. Partial results have been obtained. Determining which operators are extreme seems to be a difficult task, even in the scalar case. Here we consider the case of extreme contractions on

C
(
K
,
E
)

C(K,E)

, where

E
E

itself is a Banach space. We show that every extreme contraction

T
T

on

C
(
K
,
E
)

C(K,E)

to itself which maps extreme points to elements of norm one is nice, where

K
K

is compact and

E
E

is the sequence space

c

0

c_{0}

.
Functions 𝑞-orthogonal with respect to their own zeros
Authors: Abreu Luis
Published: May 2006

In 1939, G. H. Hardy proved that, under certain conditions, the only functions satisfying

∫

0

1

f
(

λ

m

t
)
f
(

λ

n

t
)
d
t
=
0
,

\begin{equation*} \int _{0}^{1}f(\lambda _{m}t)f(\lambda _{n}t)dt=0, \end{equation*}

where the

λ

n

\lambda _{n}

are the zeros of

f
f

, are the Bessel functions. We replace the above integral by the Jackson

q
q

-integral and give the

q
q

-analogue of Hardy’s result.
On 𝑝-adic Hermitian Eisenstein series
Authors: Nagaoka Shoyu
Published: May 2006

In this paper we generalize the notion of

p
p

-adic modular form to the Hermitian modular case and prove a formula that shows a coincidence between certain

p
p

-adic Hermitian Eisenstein series and the genus theta series associated with Hermitian matrix with determinant

p
p

.
A landing theorem for periodic rays of exponential maps
Authors: Rempe Lasse
Published: May 2006

For the family of exponential maps

z
↦
exp
⁡
(
z
)
+
κ

z\mapsto \exp (z)+\kappa

, we show the following analog of a theorem of Douady and Hubbard concerning polynomials. Suppose that

g
g

is a periodic dynamic ray of an exponential map with nonescaping singular value. Then

g
g

lands at a repelling or parabolic periodic point. We also show that there are periodic dynamic rays landing at all periodic points of such an exponential map, with the exception of at most one periodic orbit.
Ribbon-moves for 2-knots with 1-handles attached and Khovanov-Jacobsson numbers
Authors: Carter J. , Saito Masahico , Satoh Shin
Published: May 2006

We prove that a crossing change along a double point circle on a

2
2

-knot is realized by ribbon-moves for a knotted torus obtained from the

2
2

-knot by attaching a

1
1

-handle. It follows that any

2
2

-knots for which the crossing change is an unknotting operation, such as ribbon

2
2

-knots and twist-spun knots, have trivial Khovanov-Jacobsson number.
Regularized product expressions of higher Riemann zeta functions
Authors: Momotani Tetsuya
Published: May 2006

As a generalization of recent work by Kurokawa, Matsuda, and Wakayama (2004) we introduce a higher Riemann zeta function for an abstract sequence. Then we explicitly determine its regularized product expression.
The Bedrosian identity for the Hilbert transform of product functions
Authors: Xu Yuesheng , Yan Dunyan
Published: May 2006

We investigate a necessary and sufficient condition which ensures validity of the Bedrosian identity for the Hilbert transform of a product function

f
g

fg

. Convenient sufficient conditions are presented, which cover the classical Bedrosian theorem and provide us with new insightful information.
Linear independence of pseudo-splines
Authors: Dong Bin , Shen Zuowei
Published: May 2006

In this paper, we show that the shifts of a pseudo-spline are linearly independent. This is stronger than the (more obvious) statement that the shifts of a pseudo-spline form a Riesz system. In fact, the linear independence of a compactly supported (refinable) function and its shifts has been studied in several areas of approximation and wavelet theory. Furthermore, the linear independence of the shifts of a pseudo-spline is a necessary and sufficient condition for the existence of a compactly supported function whose shifts form a biorthogonal dual system of the shifts of the pseudo-spline.
A Gâteaux differentiability space that is not weak Asplund
Authors: Moors Warren , Somasundaram Sivajah
Published: May 2006

In this paper we construct a Gâteaux differentiability space that is not a weak Asplund space. Thus we answer a question raised by David Larman and Robert Phelps from 1979.