bluuebunny/crossref_metadata_2025 huggingface dataset:
A COMPARISON OF EPSTEIN‐BARR VIRUS‐SPECIFIC T‐CELL IMMUNITY IN RHEUMATOID ARTHRITIS AND OSTEOARTHRITIS PATIENTS
Authors: Moss DJ , Klestov A , Burrows S , Kane RG
Published: August 2007

The level of Epstein‐Barr virus (EBV)‐specific T‐cell‐mediated immunity in 20 rheumatoid arthritis (RA) patients was compared with 16 age‐and sex‐matched osteoarthritis (OA) patients using the regression of EBV‐transformation assay. The results show that the level of EBV‐specific T‐cell immunity in RA patients is significantly depressed compared with OA patients (P<.001) or healthy laboratory controls (P<.001). In contrast, lymphocytes from RA and OA patients showed a similar ability to act as a responder population in the mixed leucocyte reaction. It is unlikely that the difference in EBV‐specific immunity is due to a general T‐cell defect in RA patients since there was no correlation between EBV‐specific T‐cell immunity and mixed leucocyte reactivity. There was no correlation between EBV‐specific T‐cell immunity and any of the indicators of disease activity nor was there any difference in the anti‐EBV antibody titre between both groups of patients. These results indicate that RA patients are deficient in the EBV‐specific cytotoxic T‐cell precursor population and may explain some of the reported observations of the involvement of EBV in this disease.
CELL‐MEDIATED IMMUNE RESPONSE TO ROSS RIVER VIRUS IN MICE: EVIDENCE FOR A DEFECTIVE EFFECTOR CELL RESPONSE
Authors: Aaskov JG , Dalglish DA , Davies CEA , Tucker M , Donaldson MD
Published: August 2007

Spleen cells recovered from mice during a primary infection with Ross River virus showed a virus‐specific proliferative response when challenged in vitro. The majority of the proliferating cells were T‐lymphocytes. In contrast, there was liltle detectable migration inhibition factor produclion by these spleen cells and little or no virus‐specific cytotoxic activity. Sub‐cutaneous challenge with virus elicited a weak delayed type hypersensitivity reaction.
THE EFFECT OF CEREBRAL ISCHEMIA ON THE ULTRASTRUCTURE OF THE HYPOTHALAMO‐NEURO‐HYPOPHYSIAL SYSTEM OF THE MONGOLIAN GERBIL. THE NEUROHYPOPHYSIAL AXONS AND PITUICYTES
Authors: Loesch Andrzej
Published: August 2007

The results of ultrastructural studies of the neurohypophysial axons atid pituicytes of male mongolian gerbils subjected to experimental cerebral ischemia induced by 10 min bilateral occlusion of the common carotids are reported. In gerbils with cerebral ischemia some neurohypophysial axons were well preserved and, as regards ultrastructural organization, did not differ from the control animals. Some axons showed ultrastructural changes. They were characterized by depletion of dense cored neurosecretory granules and the appearance of optically empty vesicles. These suggest the increased secretion of neurohypophysial hormones. Moreover, the findings of intra‐axonal large multilamellar bodies and externally lying tightly arranged lamellar whorls (similar to myelin sheath) were linked with simultaneous obliteration of the primary structure of certain axons. The neurohypophysis of the animals subjected to cerebral ischemia revealed the presence of ‘light’ (‘fibrillar’) and ‘dark’ pituicytes. The ‘light’ cells were characterized by large Golgi complex and the presence of fine fibrilles or fibrillar bundles which occupied a large cytoplasmic area of the cell body or of the processes. The finding of accumulated fibrilles suggests the ischemia damage of the cells. The ‘dark’ cells revealed the presence of dense cytoplasmic ground and the lobulated nucleus. In these cells ribosomes were predominant. The mitochondria were swollen in both varieties of pituicytes, arbitrarily designated here as ‘light’ (‘fibrillar’) and ‘dark’. The results of the present study, therefore, indicate a functional susceptibility of neurosecretory axons and pituicytes to haemodynamic disturbances associated with bilateral cerebral ischemia.
ADHERENCE OF MURINE PERIPHERAL BLOOD EOSINOPHILS AND NEUTROPHILS TO THE DIFFERENT PARASITIC STAGES OF NEMATOSPIROIDES DUBIUS
Authors: Penttila IA , Ey PL , Jenkin CR
Published: August 2007

Eosinophils and neutrophils, purified by density gradient centrifugation from the blood of infected mice resistant to reinfection, were tested for their ability to adhere to the different parasitic larval stages of the murine nematode parasite Nematospiroides dubius. Cells were tested for adherence to larvae which had been sensitised with immune mouse serum (IMS) or normal mouse serum (NMS) in the presence of Ca2+ and Mg2+ ions, EDTA, or EGTA. Differences were observed in the degree of cell adherence to the different stages of the parasite. However, the adherence of the two cell types to any given stage of the parasite was similar. Adherence to the sheathed infective third‐stage (L3) larvae, 96 h post‐infective larvae and to adult worms depended to a large degree on conditions suitable for complement activation (viz. fresh serum and the presence of Ca2+ and Mg2+ ions). Complement was activated both via the alternative pathway by the parasite itself and via the classical pathway by parasite‐bound antibodies. In these conditions, cell adherence probably occurred predominantly through the interaction of leucocyte third component of complement (C3) receptors with parasite‐bound C3. In contrast, adherence of cells to exsheathed L3 and to the 48 h and 72 h post‐infective larval stages appeared to involve antibody/Fc receptor as well as C3/C3 receptor interaction. The data indicate that N. dubius may undergo a series of antigenic changes during its life cycle and that antibodies capable of mediating granulocyte attachment are elicited predominantly against the early tissue developmental forms of the parasite.
COMPARISONS BY PEPTIDE MAPPING OF PROTEINS SPECIFIED BY KUNJIN, WEST NILE AND MURRAY VALLEY ENCEPHALITIS VIRUSES
Authors: Wright Peter J , Warr Heather M , Westaway EG
Published: August 2007

The relationships among virus‐specified proteins of Murray Valley encephalitis (MVE), Kunjin (KUN) and West Nile (WN) viruses were investigated by peptide mapping of exhaustive proteolytic digests of radioactively labelled polypeptides. Maps of the three structural proteins (E, C and M) derived from purified virions and of two non‐structural proteins (NV5 and NV4) obtained from infected cells were compared. For each polypeptide considered, the peptide maps of the KUN and WN virus‐specified proteins were more similar to each other than either was to the map of the corresponding MVE virus‐specified protein. Since the polypeptides considered together account for approximately 60% of the coding capacity of the flavivirus genome, our results suggested that, for the three viruses examined, the genomes of KUN and WN viruses are the most closely related.
ENZYME‐LINKED IMMUNOASSAYS FOR ANTIBODIES AGAINST VIBRIO CHOLERAE
Authors: Cooper GN , McNab Christine E , Jackson GDF , Walker Patricia
Published: August 2007

Glutaraldehyde‐treated V. choleras organisms bind firmly to the surfaces of plastic microELISA plates, thus providing a stable immobilized antigen for use in enzyme‐linked immunosorbent assays (ELISA). Serum absorption and ELISA‐inhibition experiments indicate that, in addition to detecting natural antibodies in normal rat serum, the immobilized antigen may be used to quantitate specific anti‐V. cholerae antibodies induced in rats by injection of live organisms. Apart from serotypically specific anti‐lipopolysaccharide (LPS) antibodies, the reaction with immobilized organisms seems to involve antibodies common to Inaba and Ogawa serotypes; it is suggested that these antibodies are primarily directed against antigens of the outer membrane protein complex of V. cholerae cells. These findings have led to the development of an indirect ELISA method which quantitates levels of antibodies that react with heat‐sensitive surface antigens of V. cholerae without involvement of anti‐LPS antibodies. When used in conjunction with the indirect LPS‐ELISA, the test has been found to provide a more detailed description of the serum antibody responses of rats to parenteral injections of live V. cholerae than has been reported previously.
HEPATIC SINUSOIDAL ENDOTHELIUM IN GOATS
Authors: Wright PL , Clemett JA , Smith KF , Day WA , Fraser R
Published: August 2007

The ultrastructure of the hepatic sinusoids of the goat was examined. Contrary to current belief concerning this and other ruminant species, we found the sinusoids to be lined by a smooth, continuous layer of endothelium, broken only by the presence of numerous, unoccluded fenestrae which provide a direct path of communication between the sinusoidal lumen and the space of Disse. Therefore, we suggest that a sieving function similar to that which has been shown to occur in rats may be attributed to the sinusoidal endothelium of the goat.
ISOANTIBODIES TO EPIDIDYMAL SPERM ANTIGENS IN BALB/c STRAIN OF MICE
Authors: Cukier D , Nayudu PRV
Published: August 2007

Female mice of the BALB/c isogenic strain were immunized with epididymal sperm of the male mice. Four antigenic perparations were used: whole sperm (WS), homogenized sperm (HS), protein fraction (PF) and lipid fraction (LF). Antisera were assayed for antibody activity by sperm immobilization and indirect immunofluorescence tests. The differential results between the WS and HS antisera obtained in the two tests suggest that sperm membrane surface antigen(s) may be distinct from intracellular antigen(s). PF‐antiserum showed lower but significant activity with the sperm immobilization test but weak activity with the indirect immunofluorescence test. The lipid fractions showed extremely weak activities with both tests. Indirect immunofluorescent staining was curried out on 10 μm sections of unfertilized and fertilized eggs and 2‐cell embryos. Unfertilized eggs showed no antibody binding and fertilized eggs showed patchy fluorescence of the plasma membrane and cytoplasm. In the 2‐cell embryo the fluorescence was diffuse, suggesting spreading of the sperm antigens. Comparative electrophoresis of aliquots of HS antiserum with and without incubation with washed sperm showed a clear reduction, due to adsorption by sperm, of IgG class of antibodies, on the basis of molecular weight. The differences in antigenicity between the four sperm preparations are discussed in relation to (i) possible localization of the antigens in the spermatozoa and (ii) the conformational differences of the antigens manifested by organic solvent denaturation.
DNALinux Virtual Desktop Edition
Authors: Bassi Sebastian , Gonzalez Virginia
Published: August 2007

The new version of DNALinux (VDE) is presented. DNALinux VDE is a departure from traditional distributions since it uses a virtual machine to bundle together the operating system and bioinformatics applications. The main advantage of this approach is that a virtualized environment doesn't affect a installed system. With a virtual machine a Linux system can be run under a Windows system, provided that the virtual machine player is installed. The included programs are listed and specifications to add more programs are explained. We believe that DNALinux could be used as a standardized virtual machine for learning, using, developing and testing bioinformatics applications.
A diagrammatic formulation of the kinetic theory of fluctuations in equilibrium classical fluids. VI. Binary collision approximations for the memory function for self-correlation functions
Authors: Noah-Vanhoucke Joyce E. , Andersen Hans C.
Published: August 2007

We use computer simulation results for a dense Lennard-Jones fluid for a range of temperatures to test the accuracy of various binary collision approximations for the memory function for density fluctuations in liquids. The approximations tested include the moderate density approximation of the generalized Boltzmann-Enskog memory function (MGBE) of Mazenko and Yip [Statistical Mechanics. Part B. Time-Dependent Processes, edited by B. J. Berne (Plenum, New York, 1977)], the binary collision approximation (BCA) and the short time approximation (STA) of Ranganathan and Andersen [J. Chem. Phys. 121, 1243 (2004); J. Phys. Chem. 109, 21437 (2005)] and various other approximations we derived by using diagrammatic methods. The tests are of two types. The first is a comparison of the correlation functions predicted by each approximate memory function with the simulation results, especially for the self-longitudinal current correlation (SLCC) function. The second is a direct comparison of each approximate memory function with a memory function numerically extracted from the correlation function data. The MGBE memory function is accurate at short times but decays to zero too slowly and gives a poor description of the correlation function at intermediate times. The BCA is exact at zero time, but it predicts a correlation function that diverges at long times. The STA gives a reasonable description of the SLCC but does not predict the correct temperature dependence of the negative dip in the function that is associated with caging at low temperatures. None of the other binary collision approximations is a systematic improvement on the STA. The extracted memory functions have a rapidly decaying short time part, much like the STA, and a much smaller, more slowly decaying part of the type predicted by a mode coupling theory. Theories that use mode coupling commonly include a binary collision term in the memory function but do not discuss in detail the nature of that term. It is clear from the present work that the short time part of the memory function has a behavior associated with brief binary repulsive collisions, such as those described by the STA. Collisions that include attractive as well as repulsive interactions, such as those of the MGBE, have a much longer duration, and theories that include them have memory functions that decay to zero much too slowly to provide a good first approximation of the correlation function. This leads us to speculate that the memory function for density fluctuations can be usefully regarded as a sum of at least three parts: a contribution from repulsive binary collisions (the STA or something similar to it), another short time part that is related to all the other interactions (but whose nature is not understood), and a longer time slowly decaying part that describes caging (of the type predicted by the mode coupling theory).
Magnetic studies of a syn-anti triatomic carboxylate-bridging chainlike copper(II) complex exhibiting ferromagnetic exchange
Authors: Jia L. H. , Liu Z. L. , Zhu L. , Liu W. , Yao Kai-Lun
Published: August 2007

The magnetic properties of triatomic syn-anti carboxylate bridging copper(II) complex, {[Cu(2,2′-bipydine)(maleate)]∙2H2O}∞ (complex 1), were investigated experimentally and theoretically, suggesting weak ferromagnetic intrachain interaction. The magnetic data were analyzed and interpreted in terms of Heisenberg chain model corrected by a mean molecular field. Fitting parameters obtained for J, g, and zJ′ are 3.14cm−1, 2.08, and −0.13, respectively. Density functional theory with generalized gradient approximation was applied to calculate the electronic structure and spin distribution of the present complex. The structural and electronic factors controlling the magnetic interactions were also determined. Ferromagnetic intrachain interactions through triatomic syn-anti carboxylate bridge result from nonplanarity of the bridging network, the exchange pathway involving both the σ and π orbitals of the carboxylate bridge and the spin delocalization of each magnetic orbital on the atoms of the carboxylate bridge from the copper(II) centers.
Role of optical gain broadening in the broadband semiconductor quantum-dot laser
Authors: Tan C. L. , Wang Y. , Djie H. S. , Ooi B. S.
Published: August 2007

The authors present a theoretical model and analysis to gain a further insight of the broadband InGaAs∕GaAs quantum-dot laser characteristics. A detailed analysis of the role of both inhomogeneous and homogeneous optical gain broadenings on the broad lasing emission is incorporated in the theoretical model and compared with the experimental results. The experimental data of broadband laser signature agrees well with theoretical calculation confirming that the broadband stimulated emission from the laser at room temperature is a result of the occurrence of bistate lasing in highly inhomogeneous dots.
Quantification of In clustering in InGaN∕GaN multi-quantum-wells by analysis of x-ray diffraction data
Authors: Krysko M. , Leszczynski M.
Published: August 2007

The authors developed a method of quantification of lateral indium content fluctuations in InGaN∕GaN multi-quantum-wells (MQWs) grown on bulk GaN substrates. The method is based on comparison of intensities of the substrate and the MQW zeroth order peaks in 2θ-ω high resolution x-ray diffraction scans. They use a simulation program based on the kinematical theory of diffraction to fit simulated curves to the measured ones. The program uses the indium composition fluctuation amplitude as a fitting parameter.
Measurement of ultrasonic velocity with improved accuracy in pulse echo setup
Authors: Rajagopalan S. , Sharma S. J. , Dubey P. K.
Published: August 2007

In the present work a personal computer based circuit adopted in pulseecho setup has been developed for the measurement of time-of-flight between the two successive echoes using a differential time measurement with a 16bit counter and an external clock frequency of 32MHz. A control program is developed in C to display the time of flight and wave propagation velocity on a user screen. The technique, so developed, minimizes the errors in time delay measurements due to the variation in threshold trigger points of echoes and improves the ultrasonic velocity measurement.
Internal injection for a microtron driving a terahertz free electron laser
Authors: Kazakevich Grigory M. , Pavlov Viatcheslav M. , Kuznetsov Gennady I. , Jeong Young Uk , Park Seong Hee , Lee Byung Cheol
Published: August 2007

A terahertz free electron laser (FEL) driven by a high-current classical S-band 12-orbit microtron with internal injection and a magnetron-based radio frequency system has been developed. The laboratory-size, inexpensive facility is widely tunable in the terahertz range. This makes it attractive for application in research laboratories and universities. Stability and reliability in operation of such microtron-based FEL is determined generally by the microtron injection system. Operation of the injection system employing a thermionic cathode has been analyzed. The analysis was performed using two-dimensional tracking simulations in which we considered bombardment of the cathode emitting surface with the back-streaming electrons. The analysis showed that the bombardment causes pulse overheating of the emitting surface and, as a result, an increase of beam loading of the accelerating cavity during the macropulse. The phenomenon affects the intrapulse stability of the accelerated current and the FEL operation. The analysis and measurements show how to optimize the microtron operation minimizing affects of the back-streaming electrons. The developed injection system based on LaB6 thermionic cathode provides operation of the widely tunable terahertz FEL in the ordinary regime with radiated macropulse power of 40–50W at the pulse duration of 2–4μs. The standard deviation of the lasing macropulse energy is less than 10% for long-time operation.
Effects of bulk charge and momentum relaxation time scales on ac electrospraying
Authors: Maheshwari Siddharth , Chang Hsueh-Chia
Published: August 2007

The behavior at the liquid meniscus under the application of a high voltage (>4×103Vp-p), high frequency (>10kHz) alternating current (ac) signal is shown to depend very sensitively on the liquid conductivity and the applied frequency. For pure ethanol, after resonance effects become unimportant, the meniscus oscillates and then changes to a growing conical mode with increasing frequency. For ionic-liquid doped samples with higher conductivities, however, this transition to an oscillating mode and a conical mode is delayed and additional tip-streaming and elongated-fast dripping modes are seen. A linear proportionality between the transition frequency and the sample conductivity indicates that the critical period is approximately 20 times the bulk charge relaxation time scale; the mode transition takes place only when a specific and universal fraction of charge in the liquid bulk is unrelaxed. This observation for ac cones is in contrast with direct current cones with complete charge relaxation in the bulk. It also suggests that bulk Coulombic forces due to a cumulative net charge in the liquid bulk are responsible for growth of the much more slender ac cones. The vibration frequency of the oscillating mode and the ejection frequency of the elongated-fast dripping mode are found to be related to the momentum diffusion time scale across the drop and not the applied frequency.
Areal foliation and asymptotically velocity-term dominated behavior in T2 symmetric space-times with positive cosmological constant
Authors: Clausen Adam , Isenberg James
Published: August 2007

We prove a global foliation result, using areal time, for T2 symmetric space-times with a positive cosmological constant. We then find a class of solutions that exhibit asymptotically velocity-term dominated behavior near the singularity.
Cholesterol biosensor based on rf sputtered zinc oxide nanoporous thin film
Authors: Singh S. P. , Arya Sunil K. , Pandey Pratibha , Malhotra B. D. , Saha Shibu , Sreenivas K. , Gupta Vinay
Published: August 2007

Cholesterol oxidase (ChOx) has been immobilized onto zinc oxide (ZnO) nanoporous thin films grown on gold surface. A preferred c-axis oriented ZnO thin film with porous surface morphology has been fabricated by rf sputtering under high pressure. Optical studies and cyclic voltammetric measurements show that the ChOx∕ZnO∕Au bioelectrode is sensitive to the detection of cholesterol in 25–400mg∕dl range. A relatively low value of enzyme’s kinetic parameter (Michaelis-Menten constant) ∼2.1mM indicates enhanced enzyme affinity of ChOx to cholesterol. The observed results show promising application of nanoporous ZnO thin film for biosensing application without any functionalization.
Phase tunable multilevel diffractive optical element based single laser exposure fabrication of three-dimensional photonic crystal templates
Authors: Chanda Debashis , Herman Peter R.
Published: August 2007

The fabrication of diamond-like three-dimensional photonic crystal templates using a single laser exposure through a diffractive optical element has been demonstrated. An orthogonal combination of two linear phasemasks was used to define a two-dimensional diffractive optical element of multiple phase levels. By adjusting the gap between two phasemasks, a variable phase shift is shown by theory and demonstrated experimentally to control the interlacing position of two orthogonally rotated periodic structures. The transition of formation of diamond-like woodpile structures having tetragonal symmetry to structures having body-centered-tetragonal symmetry and variations in between has been demonstrated.
Formation of one-dimensional nanoparticle chains
Authors: Chen Yu , Goldman A. M.
Published: August 2007

The authors report an approach to forming one-dimensional chains of nanoparticles. It is a purely physical process and thus is free from both chemical contamination and residue side products. The size of the dots as well as the interdot spacing can be manipulated by adjusting the conditions of a postannealing process, changing the initial wire width, or using different substrates. Taking advantage of the capability for precise positioning using e-beam lithograpy, this method is a relatively simple route to fabricating one-dimensional nanoparticle chains with precise geometries.
Infrared reflection-absorption spectroscopy of Alq3 thin film on silver surface using synchrotron radiation
Authors: Sakurai Yoko , Kimura Shin-ichi , Seki Kazuhiko
Published: August 2007

Infrared reflection-absorption spectra of Alq3 film on Ag surface have been measured as a function of thickness in the wave number region from 300to500cm−1 using synchrotron radiation to determine which of the geometrical isomers of Alq3 is dominant. The observed spectra of the Al–N stretching modes of Alq3 indicate that Alq3 film predominantly consists of the meridional isomer including the first monolayer adsorbed on the Ag surface. In the spectrum of the monolayer Alq3, the Al–N stretching mode was observed to be located at wave number slightly lower than that of multilayer Alq3 probably due to the charge transfer between Alq3 and the Ag surface.
Surface plasmon leakage in its coupling with an InGaN∕GaN quantum well through an Ohmic contact
Authors: Yeh Dong-Ming , Huang Chi-Feng , Lu Yen-Cheng , Chen Cheng-Yen , Tang Tsung-Yi , Huang Jeng-Jie , Shen Kun-Ching , Yang Ying-Jay , Yang C. C.
Published: August 2007

The authors demonstrate the leakage of surface plasmon (SP) through the Ohmic contact of either p-type or n-type GaN layer in the coupling process between SP and an InGaN∕GaN quantum well (QW). It is shown that the photoluminescence (PL) intensity is significantly reduced when an Ohmic contact is formed, in contrast to the case of significant PL enhancement when an insulating thin layer is applied between the doped semiconductor and metal. The observation implies that, in using the SP-QW coupling for enhancing emission in a light-emitting diode, the metals for Ohmic contact and SP generation must be isolated from each other. A thin dielectric interlayer in the region for SP-QW coupling is useful for avoiding the leakage of SP energy.
Plasma ehnancement of metalorganic chemical vapor deposition and properties of Er2O3 nanostructured thin films
Authors: Giangregorio Maria M. , Losurdo Maria , Sacchetti Alberto , Capezzuto Pio , Bruno Giovanni , Malandrino Graziella , Fragalà Ignazio L. , Lo Nigro Raffaella , Armelao Lidia , Barreca Davide , Tondello Eugenio
Published: August 2007

An O2 remote plasma metal organic chemical vapor deposition (RP-MOCVD) route is presented for tailoring the structural, morphological, and optical properties of Er2O3 thin films grown on Si(100) using the tris(isopropylcyclopentadienyl)erbium precursor. The RP-MOCVD approach produced highly (100)-oriented, dense, and mechanically stable Er2O3 films with columnar structure.
Annealing characteristics of electrically isolated InGaAsP devices
Authors: Ahmed S. , Nawaz R. , Syed W. A. , Taiq R. , Amirov K. , Larsson U.
Published: August 2007

The authors report on the effects of fluorine implants on the sheet resistivity of n-type InGaAsP layers grown lattice matched to InP by metal organic molecular beam epitaxy. Projected range matched fluorine ions are implanted at multiple energies and single MeV energy at room temperature (RT) and 77K in both cases. Hall and resistivity measurements are carried out for the van der Pauw samples and the evolution of sheet resistivity (Rs) as a function of annealing temperature was studied in both cases. Fluorine multienergy implantation at 77K produces higher as-implanted resistivity layers of ∼107Ω∕◻ compared to RT implants. It is further observed that RT and 77K implants recover to their preimplanted sheet resistivity values as soon as they are annealed at temperatures higher than 500°C. Substrate temperature and collision cascade density due to multiple energy implants are found to play an important role to optimize the isolation process.
Zn vacancy induced room-temperature ferromagnetism in Mn-doped ZnO
Authors: Yan Wensheng , Sun Zhihu , Liu Qinghua , Li Zhongrui , Pan Zhiyun , Wang Jie , Wei Shiqiang , Wang Dan , Zhou Yingxue , Zhang Xinyi
Published: August 2007

X-ray absorption fine structure (XAFS) and first-principles calculations were employed to study the structure and ferromagnetism origin of Zn0.97Mn0.03O thin film grown by metal organic chemical vapor deposition. The magnetization measurements indicate that this sample is ferromagnetic at room temperature. The Mn ions are located at the substitutional Zn sites as revealed by the Mn K-edge XAFS spectroscopy. Moreover, the O K-edge XAFS analysis indicated the existence of numerous Zn vacancies. Based on first-principles calculations, the authors propose that the Zn vacancy can induce the room-temperature ferromagnetism in Mn-doped ZnO.
2.5
λ
microcavity InGaN light-emitting diodes fabricated by a selective dry-etch thinning process
Authors: Choi Yong-Seok , Iza Michael , Matioli Elison , Koblmüller Gregor , Speck James S. , Weisbuch Claude , Hu Evelyn L.
Published: August 2007

The authors report on InGaN microcavity light-emitting diodes with an effective thickness of ∼450nm at the emission wavelength of ∼415nm. The starting material for the flip-chip laser lift-off device is a structure with an active region embedding six InGaN∕GaN quantum wells, ∼60-nm-thick AlGaN, and a GaN template grown on a c-plane sapphire substrate. High-precision control of the final microcavity thickness was facilitated by SF6-based selective inductively coupled plasma etching on the flipped material with an etch rate of ⩾5:1 for GaN:AlxGa1−xN, where x⩾0.15. Pronounced microcavity effects were observed by angular measurements, in agreement with the theoretical cavity-mode dispersion characteristics.
Misfit strain relaxation and dislocation formation in supercritical strained silicon on virtual substrates
Authors: Parsons J. , Parker E. H. C. , Leadley D. R. , Grasby T. J. , Capewell A. D.
Published: August 2007

Relaxation of strained silicon on 20% linear graded virtual substrates was quantified using high resolution x-ray diffraction and a defect etching technique. The thickness of strained silicon was varied between 10 and 180nm. Relaxation was observed in layers below the critical thickness but increased to only 2% relaxation in the thickest layers even with annealings up to 950°C. Cross-sectional transmission electron microscopy revealed stacking faults present in layers thicker than 25nm, and nucleated 90° Shockley partial dislocations forming microtwins in the thickest layer. These features are implicated in the impediment of the relaxation process.
Amplitude death in coupled chaotic solid-state lasers with cavity-configuration-dependent instabilities
Authors: Wei Ming-Dar , Lun Jau-Ching
Published: August 2007

In the mutually coupled Nd:YVO4 laser system with cavity-configuration-dependent instability, amplitude death was observed when the frequencies of the relaxation oscillation of the lasers were close to each other. Under asymmetrical coupling, the system followed a route via semiamplitude death to amplitude death. Simulation results support the existence of amplitude death in mutually coupled solid-state lasers with cavity-configuration-dependent instability.
Anomalous thickness and dopant effects on photochemical deposition of Ag on epitaxial TiO2(110)∕Nb:TiO2(110) heterostructures
Authors: Abe T. , Ohsawa T. , Katayama M. , Koinuma H. , Matsumoto Y.
Published: August 2007

The authors have found anomalous thickness and dopant effects on photochemical deposition of Ag on the epitaxial heterostructures of TiO2(110) and V:TiO2(110)∕Nb:TiO2(110). The photodeposition of Ag on TiO2(110)∕Nb:TiO2(110) is limited to a specific film thickness region of about 5nm and the V doping is found to enhance the photoactivity, irrespective of the film thickness, on V:TiO2(110)∕Nb:TiO2(110). They have also found that the film thickness for maximum photoactivity depends on the wavelength of the irradiated light.
What Makes Environmental Performance Differ between Firms? Empirical Evidence from the Spanish Tile Industry
Authors: Picazo-Tadeo Andrés J , García-Reche Andrés
Published: August 2007

Environmental performance is a matter of major concern both for policy makers and for firm managers. In this paper we interpret firms' environmental performance as their ability to reduce polluting wastes while maintaining observed levels of inputs and desirable outputs. Making use of data envelopment analysis techniques, we compute waste-specific environmental efficiency measures for a sample of ceramic-tile producers located in the eastern Spanish region of Valencia. Our results show that there exists substantial room for improving environmental performance, which would have highly beneficial consequences for the local environment. In a second stage of analysis, we find that affiliation to the regional Technological Institute, ITC, which aims to promote technological innovation within the ceramic-tile industry, improves tile firms' environmental efficiency. In addition, firms located in the local industrial district of the Plana Baixa enjoy what we have broadly defined as ‘environmental spillovers’, which enhance their environmental performance. Also, ceramic-tile firms which outsource the management of wastes show better environmental performance.
Elitism, Pluralism, or Resource Dependency: Patterns of Environmental Philanthropy among Private Foundations in California
Authors: Delfin Francisco G , Tang Shui-Yan
Published: August 2007

We map the distribution of environmental grants provided by selected California foundations in 2000 and the degree of dependency of the grantees on foundation support to test theoretical claims about foundations' role in contemporary environmentalism. Contrary to assertions by critics of elitism, there is no consistent favoritism of the so-called ‘mainstream’, ‘flagship’, national environmental organizations as recipients of foundations' grants. Instead, donors support a variety of causes with varying levels of funding based on recipients' perceived expertise and needs—a finding consistent with pluralist and resource-dependency arguments. On the receiving end, we find that the non-governmental organizations (NGOs) that have greater reliance on foundation money are those which are younger, have fewer paying members, and are not involved in local-level or toxics issues. Overall, we find that no single theory can adequately explain the trends in giving and in dependency. Future research building on these findings can proceed along two directions: a theoretical path in search of a more universal theory of foundation giving; or an empirical path focusing on clarifying different types of NGO grantees, the longitudinal patterns of environmental giving, and the impact of foundation funding on NGO grantees.
A Multiregion Model with Capital Accumulation and Endogenous Amenities
Authors: Zhang Wei-Bin
Published: August 2007

The author develops a multiregional growth model with endogenous amenity and capital accumulation for any number of regions. The simulation results demonstrate that the national dynamics have a unique equilibrium. Comparative statics analysis shows that, if environmental improvement occurs in the technologically advanced (less advanced) region, the national output rises (falls). As a region improves its technology, the other two regions' aggregated output levels fall—not only in relative, but also in absolute, terms. This implies that if any region has a high rate of technological change and the other regions remain technologically stationary, then economic activities will tend to be concentrated in the technologically advancing region. It is also shown that technological differences appear to play only a small role in accounting for spatial wage disparities and endowments.
Developing Britain's Port Infrastructure: Markets, Policy, and Location
Authors: Asteris Michael , Collins Alan
Published: August 2007

The authors draw on historical evidence, recent public inquiry documentation and maritime port-capacity forecasts to examine the logic and consistency of British seaport infrastructure development. In light of the rejection of the Dibden Bay (Southampton) container-port proposal, the authors counterpoint the UK government position with the views and evidence presented by key players in the port and shipping industry. The respective standpoints are shown to be markedly divergent in a number of key respects. The principal conclusion is that market forces are of critical importance in determining the nature and location of port developments. Consequently, unless shippers are provided with sufficiently flexible facilities in the locations they prefer, Britain could, as in the 1980s, find itself in danger of becoming little more than an appendage to the major North European continental ports. The delicate balance between interventionist and market-led port development is an issue that will inevitably be encountered in other geographical contexts.
Bacterial sensor kinase TodS interacts with agonistic and antagonistic signals
Authors: Busch Andreas , Lacal Jesús , Martos Ariadna , Ramos Juan L. , Krell Tino
Published: August 2007

The TodS/TodT two-component system controls expression of the toluene dioxygenase (TOD) pathway for the metabolism of toluene in
Pseudomonas putida
DOT-T1E. TodS is a sensor kinase that ultimately controls
tod
gene expression through its cognate response regulator, TodT. We used isothermal titration calorimetry to study the binding of different compounds to TodS and related these findings to their capacity to induce gene expression
in vivo
. Agonistic compounds bound to TodS and induced gene expression
in vivo
. Toluene was a powerful agonist, but
ortho
-substitutions of toluene reduced or abolished
in vivo
responses, although TodS recognized
o
-xylene with high affinity. These compounds were called antagonists. We show that agonists and antagonists compete for binding to TodS both
in vitro
and
in vivo
. The failure of antagonists to induce gene expression
in vivo
correlated with their inability to stimulate TodS autophosphorylation
in vitro
. We propose intramolecular TodS signal transmission, not molecular recognition of compounds by TodS, to be the phenomenon that determines whether a given compound will lead to activation of expression of the
tod
genes. Molecular modeling identified residues F46, I74, F79, and I114 as being potentially involved in the binding of effector molecules. Alanine substitution mutants of these residues reduced affinities (2- to 345-fold) for both agonistic and antagonistic compounds. Our data indicate that determining the inhibitory activity of antagonists is a potentially fruitful alternative to design specific two-component system inhibitors for the development of new drugs to inhibit processes regulated by two-component systems.
Population genetics of the frog-killing fungus
Batrachochytrium dendrobatidis
Authors: Morgan Jess A. T. , Vredenburg Vance T. , Rachowicz Lara J. , Knapp Roland A. , Stice Mary J. , Tunstall Tate , Bingham Rob E. , Parker John M. , Longcore Joyce E. , Moritz Craig , Briggs Cheryl J. , Taylor John W.
Published: August 2007

Global amphibian decline by chytridiomycosis is a major environmental disaster that has been attributed to either recent fungal spread or environmental change that promotes disease. Here, we present a population genetic comparison of
Batrachochytrium dendrobatidis
isolates from an intensively studied region of frog decline, the Sierra Nevada of California. In support of a novel pathogen, we find low diversity, no amphibian-host specificity, little correlation between fungal genotype and geography, local frog extirpation by a single fungal genotype, and evidence of human-assisted fungus migration. In support of endemism, at a local scale, we find some diverse, recombining populations. Therefore neither epidemic spread nor endemism alone explains this particular amphibian decline. Recombination raises the possibility of resistant sporangia and a mechanism for rapid spread as well as persistence that could greatly complicate global control of the pathogen.
Pivotal role for neuronal Toll-like receptors in ischemic brain injury and functional deficits
Authors: Tang Sung-Chun , Arumugam Thiruma V. , Xu Xiangru , Cheng Aiwu , Mughal Mohamed R. , Jo Dong Gyu , Lathia Justin D. , Siler Dominic A. , Chigurupati Srinivasulu , Ouyang Xin , Magnus Tim , Camandola Simonetta , Mattson Mark P.
Published: August 2007

The innate immune system senses the invasion of pathogenic microorganisms and tissue injury through Toll-like receptors (TLR), a mechanism thought to be limited to immune cells. We now report that neurons express several TLRs, and that the levels of TLR2 and -4 are increased in neurons in response to IFN-γ stimulation and energy deprivation. Neurons from both TLR2 knockout and -4 mutant mice were protected against energy deprivation-induced cell death, which was associated with decreased activation of a proapoptotic signaling cascade involving jun N-terminal kinase and the transcription factor AP-1. TLR2 and -4 expression was increased in cerebral cortical neurons in response to ischemia/reperfusion injury, and the amount of brain damage and neurological deficits caused by a stroke were significantly less in mice deficient in TLR2 or -4 compared with WT control mice. Our findings establish a proapoptotic signaling pathway for TLR2 and -4 in neurons that may render them vulnerable to ischemic death.
The Fallacy of Wage Cuts and Keynes's Involuntary Unemployment
Authors: Levendis John
Published: August 2007

The lingering economic problem for economists in the 1920s and 1930s was unemployment. What caused it? More importantly, what could cure it? John Maynard Keynes's work offered new insights regarding both the reasons for, and the cures of, lingering and massive unemployment—what Keynes called “involuntary unemployment.” Keynes's definition of the term evolved as he gradually came to realize the role of the fallacy of composition in explaining why nominal wage rate adjustments might not induce full employment. I argue that it was Richard Kahn's multiplier article, more than anything, which guided Keynes's own understanding of the phenomenon. This paper, then, is a narrative history of how Keynes came to grips with the unprecedented level of unemployment in the 1920s and '30s interpreted through the lens of the Kahnian multiplier.
An evaluation of counselling and rehabilitation courses for Chronic Fatigue Syndrome
Authors: Thomas Marie , Smith Andrew
Published: August 2007

The aim of the current study was to evaluate the services offered by Action for ME to sufferers of Chronic Fatigue Syndrome using measures developed and validated in previous research. Preliminary studies had suggested that clients attending rehabilitation residential courses were benefiting from the service. A further, more in‐depth evaluation process with a greater number of health‐related outcome measures was warranted. In addition, assessment was widened to include other services offered to sufferers of the illness. Data relating to the usefulness and success of the services (rated by the clients) were also collected. Data from client volunteers were collected at baseline (that is, before intervention) and approximately six months later. Quantitative comparative analyses were conducted using within‐group comparisons to assess any improvements in scores at six‐month follow‐up from baseline. Fifty‐six participants completed wide‐ranging questionnaires assessing illness history, psychopathology, psychosocial factors and health and well‐being. Data relating to improvements in illness status and acceptability of treatment were also collected by means of global outcome measures. Both the counselling and residential groups showed improvements in many areas assessed at follow‐up. Most importantly, improvements were indicated in areas such as fatigue and the levels of disability suffered by patients. In addition, there were significant improvements in ratings of mood, anxiety, depression and physical symptoms. Overall, clients reported satisfaction with the care received and most found the services useful. All of the participants who completed the evaluation stated that they would recommend Action for ME services to fellow sufferers. The outcome of the current study is encouraging. The data presented provides evidence of the high level of support and advice Action for ME offers to sufferers of this illness. Furthermore, measurable improvements in scores relating to illness status were accompanied by improvements in mental health and psychosocial variables in the patient group.
A pluralistic framework for counselling and psychotherapy: Implications for research
Authors: Cooper Mick , McLeod John
Published: August 2007

Historically, training, research and practice in counselling and psychotherapy have been dominated by unitary theoretical models. Although integrative and eclectic positions have been developed as alternatives, these have not been successful in generating research and have resulted in a further proliferation of competing models. In this paper we introduce a ‘pluralistic’ framework for counselling and psychotherapy and discuss the implications of this framework for research. The basic principle of this pluralistic framework is that psychological difficulties may have multiple causes and that there is unlikely to be one, ‘right’ therapeutic method that will be appropriate in all situations—different people are helped by different processes at different times. This pluralistic framework operates as a meta‐theory within which it is possible to utilise concepts, strategies and specific interventions from a range of therapeutic orientations. The framework is structured around three domains—goals, task and methods—by which therapeutic processes can be conceptualised, critically examined and empirically investigated. These domains, and the relationships between them, are outlined and the collaborative relationship at the heart of the pluralistic framework is discussed. The pluralistic framework provides a means for empirical research directly to inform practice and potential lines of empirical inquiry are outlined, along with findings from a recent study of counselling in schools.
Online self‐help: Developing a student‐focused website for depression
Authors: Meyer Denise
Published: August 2007

Many depressed people, young men in particular, do not seek professional help. This social constructionist action research project aimed to construct a comprehensive self‐help website for students. Its goal was to give a multi‐layered (‘thick’) account of depression to website users offering empowering perspectives and strategies while challenging barriers to help‐seeking. Thirteen student interviewees, representing diverse demographics and depression experiences, attended semi‐structured interviews to elicit ‘coping’ narratives. Ten of them then formed an ongoing e‐mail focus group. An evaluative action research spiral was used to analyse and act upon public health guidelines, student interviews and student focus group commentary. Triangulation was provided via the specifications and ongoing feedback from the other project stakeholders. These were the funding charity steering group (including heads of university counselling services); the university providing programme/ethical approval; and the expert group offering clinical validation. The final site at www.studentdepression.org has nearly 100 pages of information and self‐help resources cross‐referenced with personal narratives. It provides a rich, complex account of how depression may be tackled and resisted. Both student and expert groups were impressed with final site quality and usefulness. Collaborative development with user‐group representatives is likely to have produced a far richer, more accessible and more comprehensive resource than counsellor authorship alone.1