bluuebunny/crossref_metadata_2025 huggingface dataset:
Spin filtering and spin-polarization reversal in multilayered ferromagnetic metal/semiconductor heterostructures
Authors: Guo Yong , Yu Xiao-Wei , Li Yu-Xian
Published: August 2005

We investigate spin-filtering effect in multilayered ferromagnetic (F)/semiconductor (S) heterostructures within the Landauer framework of ballistic transport. Spin-dependent transmission and polarization are calculated and analyzed for different magnetizations of three ferromagnetic layers in a F∕S∕F∕F structure proposed in this work. The results indicate that in such a multilayered configuration and when the magnetizations of the middle and the right ferromagnetic layers are antiparallel, the transmission for spin-up and spin-down electrons can be separated, which is quite different from the transport properties in the F∕S∕F structure, where electrons of different spin orientations have exactly the same contributions to transmission if the magnetic moments of the two ferromagnetic layers are antiparallel. It is also shown that the F∕S∕F∕F structure can have big values of the polarization than the F∕S∕F structure. The quantum size effect of the length of the middle ferromagnetic layer and that of the semiconductor layer are discussed. Moreover, the polarization can be reversed when we switch the magnetizations of the middle and the right ferromagnetic layers.
Experimental study on thickness-related electrical characteristics in organic/metal-nanocluster/organic systems
Authors: Pyo Seungmoon , Ma Liping , He Jun , Xu Qianfei , Yang Yang , Gao Yongli
Published: August 2005

Organic bistable devices with the trilayer structure, organic/metal-nanocluster/organic, interposed between two electrodes have been systematically studied by varying the thickness of the organic layers and the metal-nanocluster layer. Devices fabricated in this fashion exhibit either electrical bistability or current step, depending on the thickness of the metal-nanocluster layer. Electrical bistable devices have been studied by fixing the metal-nanocluster layer thickness at 20 nm and changing the organic-layer thickness from 20 to 60 nm. Device injection current at the on state shows an exponential decrease with an increasing organic-layer thickness, suggesting that the electron transmission probability of the devices decreases with an increasing thickness of the organic layer. This is in agreement with theoretical calculations based on the single-band Hubbard model. The evolution of the electrical current step is observed for devices fabricated by fixing the organic-layer thickness at 50 nm and changing the metal-nanocluster layer thicknesses (2, 4, and 8 nm). The discontinuous metal-nanocluster layer is believed to lead to the observed current step. When the metal-nanocluster layer is thick enough resonant tunneling occurs between nanoclusters causing positive and negative charges to be stored on the opposite sides of the metal-nanocluster layer inducing electrical bistability. Discussions of the observed phenomena are presented.
Optical and structural investigation of In1−xGaxP free-standing microrods
Authors: Nakaema M. K. K. , Godoy M. P. F. , Brasil M. J. S. P. , Iikawa F. , Silva D. , Sacilotti M. , Decobert J. , Patriarche G.
Published: August 2005

We present a structural and optical characterization of scepterlike micrometer-sized free-standing structures, composed of a long InGaP rod with a metallic sphere on its top, grown on polycrystalline InP substrates. In contrast to the conventional vapor-liquid-solid growth method, no catalyst was deposited on the substrate. Instead, metallic In liberated from the InP substrate by phosphor evaporation works as the catalyst metal. We performed Raman scattering, photoluminescence spectroscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy measurements on individual structures. The alloy composition measured by microscopic techniques is in agreement with the values obtained by the optical measurements considering that the rod is strain free. The InGaP rods present essentially constant Ga composition within a fluctuation of ∼10% and efficient optical emission. We also observed a marked increase in the Raman-scattering signal at rod positions near the metallic sphere (the “neck”), which was attributed to a surface-enhanced Raman-scattering effect. Our results demonstrate the possibility of using InGaP rods for optical device applications.
Aluminum nitride emission from a laser-induced plasma in a dispersed aerosol
Authors: Glumac Nick
Published: August 2005

Emission from gas-phase AlN has been observed from a laser spark in a dilute suspension of AlN and Al nanoparticles in gaseous nitrogen. AlN emits most strongly in the 10–100-μs time period after laser excitation, and the emission is strong enough to be analyzed at moderately high dispersions. Under these high-temperature conditions, the population of high rotational levels results in there being a greater number of transitions than was observed by previous investigators, suggesting that the upper-state predissociation is fairly weak, and transitions over a much wider range of wavelengths are accessible for absorption-based diagnostics. The AlN emission is found to result primarily from the reaction of gas-phase nitrogen with vaporized aluminum.
Thermal stability of diamondlike carbon buried layer fabricated by plasma immersion ion implantation and deposition in silicon on insulator
Authors: Di Zengfeng , Huang Anping , Fu Ricky K. Y. , Chu Paul K. , Shao Lin , Höchbauer T. , Nastasi M. , Zhang Miao , Liu Weili , Shen Qinwo , Luo Suhua , Song Zhitang , Lin Chenglu
Published: August 2005

Diamondlike carbon (DLC) as a potential low-cost substitute for diamond has been extended to microelectronics and we have demonstrated the fabrication of silicon on diamond (SOD) as a silicon-on-insulator structure using plasma immersion ion implantation and deposition in conjunction with layer transfer and wafer bonding. The thermal stability of our SOD structure was found to be better than that expected for conventional DLC films. In the work reported here, we investigate the mechanism of the enhanced thermal stability. We compare the thermal stability of exposed and buried DLC films using Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). Our Raman analysis indicates that the obvious separation of the D and G peaks indicative of nanocrystalline graphite emerges at 500°C in the exposed DLC film. In contrast, the separation appears in the buried DLC film only at annealing temperatures above 800°C. Analysis of the XPS C1s core-level spectra shows that the (sp3+C–H) carbon content of the unprotected DLC film decreases rapidly between 300–700°C indicating the rapid transformation of sp3-bonded carbon to sp2-bonded carbon combined with hydrogen evolution. In comparison, the decrease in the (sp3+C–H) carbon content of the buried DLC film is slower below 800°C. Elastic recoil detection results show that this superior thermal stability is due to the slower hydrogen out diffusion from the buried DLC film thereby impeding the graphitization process. We propose that the SiO2 overlayer retards the graphitization process during annealing by shifting the chemical equilibrium.
Spin collinearity and thermal disorder in ε-Fe2O3
Authors: Tronc E. , Chanéac C. , Jolivet J. P. , Grenèche J. M.
Published: August 2005

Studies of magnetoelectric ε-Fe2O3 nanoparticles (30nm) in silica by Fe57 Mössbauer spectrometry (4.2–600K,0–6T) are reported. They indicate a magnetic/structural transition at ∼130K, a high-temperature collinear ferrimagnetic spin structure similar to FeGaO3 and FeAlO3, and the Curie temperature TC at 585K. Reduced hyperfine field versus T∕TC is (S=5∕2) Brillouin-like or Langevin-like according to the structural site. The magnetization at 300K is estimated to 0.25μB∕Fe in accord with published data.
Properties of electron acceleration by a circularly polarized laser in vacuum
Authors: Xu J. J. , Ho Y. K. , Kong Q. , Chen Z. , Wang P. X. , Wang W. , Lin D.
Published: September 2005

The dynamic characteristics of an electron accelerated by ultraintense circularly polarized laser pulses in vacuum following the capture and acceleration scenario were studied. Comparing them with that from the use of linearly polarized laser pulses, we found (i) that the acceleration channel is wider, leading to greater acceleration efficiency, and (ii) that the maximum energy gains rise much more slowly as the laser intensity increases. This slow rise is caused by the magnetic-field force, which weakens the longitudinal acceleration force at higher laser intensity.
Superresolution and corrections to the diffusion approximation in optical tomography
Authors: Panasyuk George Y. , Markel Vadim A. , Schotland John C.
Published: August 2005

We demonstrate that the spatial resolution of images in optical tomography is not limited to the fundamental length scale of one transport mean free path. This result is facilitated by the introduction of novel corrections to the standard integral equations of scattering theory within the diffusion approximation to the radiative transport equation.
Strong effect of surfaces on resolution limit of negative-index “superlens”
Authors: Bratkovsky A. M. , Cano A. , Levanyuk A. P.
Published: August 2005

We show that a combined effect of surfaces and microscopic structure strongly reduces a resolution limit of an (otherwise perfect) negative-index slab. This effect is illustrated in a model of a sandwich of negative-index materials. As an additional result, we find that the surface electromagnetic modes may have a gap in a spectrum. The gap prevents a resonance between these modes and an incident radiation, and that can make a “subwavelength” imaging less sensitive to losses.
Transient quantum yield evolution of organic light-emitting devices submitted to low-level excitation: A photon counting investigation
Authors: Gherabi Abdellatif , Beaudoin Normand , Gauvin Serge
Published: August 2005

The continuously growing interest in organic light-emitting devices (OLEDs) requires exhaustive experimental investigations to validate the theoretical models. Here, we propose a solution to the problem of the measurement of quantum yield when devices are probed with low-level signals that minimize perturbations. Our approach is based on the wave form recovery methodology. Under pulsed excitation, our results reveal a considerable increase of the quantum yield throughout the excitation pulse. This enhancement persists for 10 ms. The procedure has the capability to reveal features of the transient behaviors and aging that are blurred when OLEDs are operated with normal driving electric field and current density. This approach may provide a complementary way to a thorough investigation of the electronic processes and aging mechanisms of OLEDs.
Interface band gap engineering in InAsSb photodiodes
Authors: Carras M. , Reverchon J. L. , Marre G. , Renard C. , Vinter B. , Marcadet X. , Berger V.
Published: August 2005

The optimization of an InAs0.91Sb0.09 based infrared detector has been performed. The importance of the interfaces between the active region and the contacts in generation recombination phenomena is demonstrated. The two sides of the active region are optimized independently through heterostructure band gap engineering. The use of an Al0.15In0.85As0.91Sb0.09 quaternary makes it possible reach a detectivity of 4.4×109cm√Hz∕W at 290 K and 1.4×1010cm√Hz∕W at 250 K at 3.39μm, offering the perspective of a noncryogenic infrared imaging in the 3–5μm band with quantum detectors.
Experimental evidence of backward waves on terahertz left-handed transmission lines
Authors: Crépin T. , Lampin J. F. , Decoopman T. , Mélique X. , Desplanque L. , Lippens D.
Published: August 2005

Left-handed transmission lines have been characterized by electro-optic sampling. The transmission lines used a coplanar strip technology periodically loaded by series capacitances and shunt inductances printed by electron-beam lithography onto a low-κ substrate. The experiments by optoelectronic sampling were conducted using low-temperature-grown GaAs and AlGaAs patches for probing the time-domain transmission properties. The devices exhibit a high-frequency response above 100 and up to 400 GHz which shows direct evidence of a backward propagation by tracking the time dependence of transmitted signals and phase analysis.
Thermal mapping of defects in AlGaN∕GaN heterostructure field-effect transistors using micro-Raman spectroscopy
Authors: Pomeroy J. W. , Kuball M. , Wallis D. J. , Keir A. M. , Hilton K. P. , Balmer R. S. , Uren M. J. , Martin T. , Heard P. J.
Published: August 2005

We illustrate the use of micro-Raman mapping to study the local effect of defects on device temperature in active AlGaN∕GaN heterostructure field-effect transistors. Significant temperature rises in active devices, 50–100% above average device temperatures, were identified in the vicinity of defects. Measured temperature distributions were compared to finite difference simulations. Reduced thermal conductivity in the defect vicinity was found to be responsible for the local temperature rises in these devices, combined with possible changes in the current flow distribution.
Electron field emission from a single carbon nanotube: Effects of anode location
Authors: Smith R. C. , Cox D. C. , Silva S. R. P.
Published: August 2005

Electron field emission from an isolated carbon nanotube (CNT) was performed in situ in a modified scanning electron microscope, over a range of anode to CNT tip separations, D, of 1–60μm. The threshold field required for an emission current of 100 nA was seen to decrease from a value of 42Vμm−1 at an anode to CNT tip separation of 1μm, asymptotically, to approach 4Vμm−1 at a separation of 60μm. It is proposed that at low D, the electric field enhancement factor (β) reduces as the anode electrode approaches the CNT mimicking a parallel plate configuration. Under “far field” conditions, where D>3h, where h is the CNT height, the CNT enhancement factor is no longer dependant on D, as shown by the asymptotic behavior of the threshold field, and is purely a factor of the CNT height and radius. For each CNT to tip separation, measured emission current data together with the threshold field and enhancement, are consistent with a Fowler-Nordheim analysis for the far field conditions, and dispels the need for a novel emission mechanism to explain the results as has been proposed recently.
Growth of single crystal ZnO nanorods on GaN using an aqueous solution method
Authors: Le H. Q. , Chua S. J. , Koh Y. W. , Loh K. P. , Chen Z. , Thompson C. V. , Fitzgerald E. A.
Published: August 2005

Uniformly distributed ZnO nanorods with diameter 80–120nm and 2μm long have been grown at low temperatures on gallium nitride (GaN) by using the inexpensive aqueous solution method. The formation of the ZnO nanorods and the growth parameters are controlled by reactant concentration, temperature and pH. No catalyst is required. The x-ray diffraction (XRD) and transmission electron microscopy (TEM) studies show that the ZnO nanorods are single crystals and they grow along the c axis of the crystal plane. The room temperature photoluminescence (PL) measurements have shown ultraviolet peaks at 388nm with high intensity, which are comparable to those found in high quality ZnO films. The mechanism of the nanorod growth in the aqueous solution is also proposed.

At the request of the authors, this article is being retracted effective 8 December 2010.
Phase stability and optimum oxygenation conditions for Sr2FeMoO6 formation
Authors: Sharma A. , MacManus-Driscoll J. L. , Branford W. , Bugoslavsky Y. , Cohen L. F. , Rager J.
Published: September 2005

The upper phase stability limit of Sr2FeMoO6 was determined in the temperature range 1140–1220°C using coulometric titration. At 1200°C, the decomposition oxygen partial pressure was determined to be 2.2×10−11atm O2. Hence at 1200°C, and for pO2’s in excess of this value, the phase is thermodynamically unstable. In order to achieve a pO2 just below the upper stability line a precise gas mixture of 2H2:1CO2 in a background carrier gas of Ar was used for the reaction atmosphere. Highly ordered samples, with high low-field magnetoresistance (LFMR) values were produced, and the very strong dependence of the LFMR on reaction time, which occurs with use of Ar∕H2 gas, was eliminated.
Regulation of hunger-driven behaviors by neural ribosomal S6 kinase in
Drosophila
Authors: Wu Qi , Zhang Yan , Xu Jie , Shen Ping
Published: September 2005

Hunger elicits diverse, yet coordinated, adaptive responses across species, but the underlying signaling mechanism remains poorly understood. Here, we report on the function and mechanism of the
Drosophila
insulin-like system in the central regulation of different hunger-driven behaviors. We found that overexpression of
Drosophila
insulin-like peptides (DILPs) in the nervous system of fasted larvae suppressed the hunger-driven increase of ingestion rate and intake of nonpreferred foods (e.g., a less accessible solid food). Moreover, up-regulation of
Drosophila
p70/S6 kinase activity in DILP neurons led to attenuated hunger response by fasted larvae, whereas its down-regulation triggered fed larvae to display motivated foraging and feeding. Finally, we provide evidence that neural regulation of food preference but not ingestion rate may involve direct signaling by DILPs to neurons expressing neuropeptide F receptor 1, a receptor for neuropeptide Y-like neuropeptide F. Our study reveals a prominent role of neural
Drosophila
p70/S6 kinase in the modulation of hunger response by insulin-like and neuropeptide Y-like signaling pathways.
Intestinal inflammation-induced growth retardation acts through IL-6 in rats and depends on the –174 IL-6 G/C polymorphism in children
Authors: Sawczenko Andrew , Azooz Omeia , Paraszczuk Joanna , Idestrom Maja , Croft Nick M. , Savage Martin O. , Ballinger Anne B. , Sanderson Ian R.
Published: September 2005

Inflammatory diseases frequently impair linear growth. Crohn's disease inhibits growth in up to one third of affected children. In rats with trinitrobenzenesulphonic acid-induced colitis, 40% of growth impairment is attributable to inflammation, with the rest being due to undernutrition. In transgenic mice without inflammation, raised IL-6 retards growth, suppressing insulin-like growth factor (IGF)-I. We hypothesized that IL-6, induced by intestinal inflammation, suppresses growth and inhibits IGF-I expression. Therefore, an anti-IL-6 Ab was given to rats with trinitrobenzene-sulphonic acid colitis. The Ab did not improve nutrient intake or decrease inflammation compared with untreated disease controls, but it significantly restored linear growth (P= 0.023) and increased IGF-I (P= 0.05). In humans, the IL-6 -174 G/C promoter polymorphism affects IL-6 transcription, with the GG genotype inducing the greatest IL-6 levels. Because IL-6 is increased in Crohn's disease, we further hypothesized that growth failure would vary with the IL-6 -174 genotype. At diagnosis, among 153 children with Crohn's disease, those with the IL-6 GG genotype were more growth-retarded than those with the GC or CC genotypes (height SD score, -0.51 vs. -0.10;P= 0.031). Also, the patients with the IL-6 GG genotype had higher circulating levels of C-reactive protein, an IL-6-induced product (36 vs. 18 mg/dl,P= 0.028). However, their risk of developing Crohn's disease was similar to other genotypes when compared with 351 healthy controls (P= 0.7). Thus, the IL-6 -174 genotype mediates growth failure in children with Crohn's disease.
Mutation of key residues of RPE65 abolishes its enzymatic role as isomerohydrolase in the visual cycle
Authors: Redmond T. Michael , Poliakov Eugenia , Yu Shirley , Tsai Jen-Yue , Lu Zhongjian , Gentleman Susan
Published: September 2005

RPE65 is essential for isomerization of vitamin A to the visual chromophore. Mutations in RPE65 cause early-onset blindness, and
Rpe65
-deficient mice lack 11-
cis
-retinal but overaccumulate
alltrans
-retinyl esters in the retinal pigment epithelium (RPE). RPE65 is proposed to be a substrate chaperone but may have an enzymatic role because it is closely related to carotenoid oxygenases. We hypothesize that, by analogy with other carotenoid oxygenases, the predicted iron-coordinating residues of RPE65 are essential for retinoid isomerization. To clarify RPE65's role in isomerization, we reconstituted a robust minimal visual cycle in 293-F cells. Only cells transfected with RPE65 constructs produced 11-
cis
-retinoids, but coexpression with lecithin:retinol acyltransferase was needed for high-level production. Accumulation was significant, amounting to >2 nmol of 11-
cis
-retinol per culture. Transfection with constructs harboring mutations in residues of RPE65 homologous to those required for interlinked enzymatic activity and iron coordination in related enzymes abolish this isomerization. Iron chelation also abolished isomerization activity. Mutating cysteines implicated in palmitoylation of RPE65 had generally little effect on isomerization activity. Mutations associated with Leber congenital amaurosis/early-onset blindness cause partial to total loss of isomerization activity in direct relation to their clinical effects. These findings establish a catalytic role, in conjunction with lecithin:retinol acyltransferase, for RPE65 in synthesis of 11-
cis
-retinol, and its identity as the isomerohydrolase.
Vasoactive intestinal peptide induces regulatory dendritic cells with therapeutic effects on autoimmune disorders
Authors: Chorny Alejo , Gonzalez-Rey Elena , Fernandez-Martin Amelia , Pozo David , Ganea Doina , Delgado Mario
Published: September 2005

The induction of antigen-specific tolerance is critical for the prevention of autoimmunity and maintenance of immune tolerance. In addition to their classical role as sentinels of the immune response-inducing T cell reactivity, dendritic cells (DCs) play an important role in maintaining peripheral tolerance through the induction/activation of regulatory T cells (Tr). The possibility to generate tolerogenic DCs opens new therapeutic perspectives in autoimmune/inflammatory diseases. Therefore, the characterization of the endogenous factors that contribute to the development of tolerogenic DCs is highly relevant. In this study, we report on the use of the known immunosuppressive neuropeptide, the vasoactive intestinal peptide, as a new approach to induce tolerogenic DCs with capacity to generate Tr cells, to restore tolerancein vivo, and to reduce the progression of rheumatoid arthritis and experimental autoimmune encephalomyelitis.
Direct observation of thitherto unobservable quantum phenomena by using electrons
Authors: Tonomura Akira
Published: September 2005

Fundamental aspects of quantum mechanics, which were discussed only theoretically as “thought experiments” in the 1920s and 1930s, have begun to frequently show up in nanoscopic regions owing to recent rapid progress in advanced technologies. Quantum phenomena were once regarded as the ultimate factors limiting further miniaturization trends of microstructured electronic devices, but now they have begun to be actively used as the principles for new devices such as quantum computers. To directly observe what had been unobservable quantum phenomena, we have tried to develop bright and monochromatic electron beams for the last 35 years. Every time the brightness of an electron beam improved, fundamental experiments in quantum mechanics became possible, and quantum phenomena became observable by using the wave nature of electrons.
Requirements for induction and maintenance of peripheral tolerance in stringent allograft models
Authors: Sho Masayuki , Kishimoto Koji , Harada Hiroshi , Livak Mauren , Sanchez-Fueyo Alberto , Yamada Akira , Zheng Xin Xiao , Strom Terry B. , Basadonna Giacomo P. , Sayegh Mohamed H. , Rothstein David M.
Published: September 2005

Peripheral tolerance can be achieved in many but not all murine allograft models. The requirements for controlling more aggressive immune responsiveness and generating peripheral tolerance in stringent allograft models are unknown. Understanding these requirements will provide insight toward ultimately achieving tolerance in humans, which are also resistant. We now demonstrate that the combination of donor-specific transfusion, anti-CD45RB, and anti-CD154 uniformly achieves >90-d survival of BALB/c skin allografts on C57BL/6 recipients. Recipients exhibit marked hyporesponsiveness to alloantigenin vitro. In distinct contrast to less rigorous models, engraftment remains absolutely dependent on cytotoxic T lymphocyte antigen 4 signaling, even after grafts are healed, suggesting that prolonged engraftment cannot simply be attributed to more effective depletion of alloreactive T cells but is actively maintained by regulation. Concordantly, we show that both CD4 and CD8 regulatory cells are required and can transfer donor-specific tolerance to naïve recipients. Nonetheless, most recipients ultimately develop gradual graft loss (median survival time = 140 d), suggesting that alloreactive cells emerging from the thymus eventually overwhelm regulatory capacity. In agreement, adding thymectomy to the regimen results in permanent engraftment (>250 d) and donor-specific tolerance not observed previously in this model. These results highlight the potency of both CD4 and CD8 regulatory cells but also suggest that in stringent settings, regulatory T cell longevity and capacity for infectious tolerance compete with prolonged graft immunogenicity and thymic output. These results provide insight into the mechanisms of tolerance in stringent models and provide a rational basis for innovative tolerogenic strategies in humans.
Regulation of synaptic plasticity in a schizophrenia model
Authors: Gisabella Barbara , Bolshakov Vadim Y. , Benes Francine M.
Published: August 2005

The pathology of schizophrenia is characterized by increased hippocampal activity at baseline and during auditory hallucinations. Animal-model studies in which the flow of activity to the hippocampus is increased through decreased amygdalar GABAergic inhibition have shown alterations of hippocampal circuitry similar to schizophrenia, but the functional importance of this phenomenon remains unclear. We provide evidence of decreased hippocampal feed-forward and tonic GABA-mediated inhibition in this animal model, complementing increased hippocampal activity seen in neuroimaging and postmortem studies. We demonstrate that GABA dysfunction increases long-term potentiation through activation of the cholinergic system, offering a new mechanism for pharmacological strategies of this disorder.
Evolutionarily divergent herpesviruses modulate T cell activation by targeting the herpesvirus entry mediator cosignaling pathway
Authors: Cheung Timothy C. , Humphreys Ian R. , Potter Karen G. , Norris Paula S. , Shumway Heather M. , Tran Bonnie R. , Patterson Ginelle , Jean-Jacques Rochelle , Yoon Miri , Spear Patricia G. , Murphy Kenneth M. , Lurain Nell S. , Benedict Chris A. , Ware Carl F.
Published: August 2005

The herpesvirus entry mediator (HVEM), a member of the TNF receptor (TNFR) superfamily, can act as a molecular switch that modulates T cell activation by propagating positive signals from the TNF-related ligand LIGHT (TNFR superfamily 14), or inhibitory signals through the Ig superfamily member B and T lymphocyte attenuator (BTLA). Competitive binding analysis and mutagenesis reveals a unique BTLA binding site centered on a critical lysine residue in cysteine-rich domain 1 of HVEM. The BTLA binding site on HVEM overlaps with the binding site for the herpes simplex virus 1 envelope glycoprotein D, but is distinct from where LIGHT binds, yet glycoprotein D inhibits the binding of both ligands, potentially nullifying the pathway. The binding site on HVEM for BTLA is conserved in the orphan TNFR, UL144, present in human CMV. UL144 binds BTLA, but not LIGHT, and inhibits T cell proliferation, selectively mimicking the inhibitory cosignaling function of HVEM. The demonstration that distinct herpesviruses target the HVEM–BTLA cosignaling pathway suggests the importance of this pathway in regulating T cell activation during host defenses.
Ancient mitochondrial M haplogroups identified in the Southwest Pacific
Authors: Merriwether D. Andrew , Hodgson Jason A. , Friedlaender Françoise R. , Allaby Robin , Cerchio Salvatore , Koki George , Friedlaender Jonathan S.
Published: September 2005

Based on whole mtDNA sequencing of 14 samples from Northern Island Melanesia, we characterize three formerly unresolved branches of macrohaplogroup M that we call haplogroups M27, M28, and M29. Our 1,399 mtDNA control region sequences and a literature search indicate these haplogroups have extremely limited geographical distributions. Their coding region variation suggests diversification times older than the estimated date for the initial settlement of Northern Island Melanesia. This finding indicates that they were among the earliest mtDNA variants to appear in these islands or in the ancient continent of Sahul. These haplogroups from Northern Island Melanesia extend the existing schema for macrohaplogroup M, with many independent branches distributed across Asia, East Africa, Australia, and Near Oceania.
A force-dependent state controls the coordination of processive myosin V
Authors: Purcell Thomas J. , Sweeney H. Lee , Spudich James A.
Published: September 2005

Myosin V is an efficient processive molecular motor. Recent experiments have shown how the structure and kinetics of myosin V are specialized to produce a highly processive motor capable of taking multiple 36-nm steps on an actin filament track. Here, we examine how two identical heads coordinate their activity to produce efficient hand-over-hand stepping. We have used a modified laser-trap microscope to apply a ≈2-pN forward or backward force on a single-headed myosin V molecule, hypothesized to simulate forces experienced by the rear or lead head, respectively. We found that pulling forward produces only a small change in the kinetics, whereas pulling backward induces a large reduction in the cycling of the head. These results support a model in which the coordination of myosin V stepping is mediated by strain-generated inhibition of the lead head.
Ewing′s Sarcoma of the Upper Extremity: Presenting Symptoms, Diagnostic Delay and Outcome
Authors: Simpson Philip M. S. , Reid Robin , Porter Daniel
Published: September 2005

Purpose:To look at the presenting features, Enneking stage, size of primary tumour, method of treatment and patient and
doctor delays in upper extremity Ewing′s sarcoma to observe the effects on local recurrence, metastasis and survival.

Patients and methods:Nineteen patients with upper extremity Ewing′s sarcoma were identified using the Scottish Bone
Tumour Registry over the past 40 years.

Results:With increasing tumour Enneking stage at presentation there was a significantly higher mortality (P=0.02).
Patients with a higher Enneking stage also had an increased trend towards local recurrence (P=0.08). Stage did not
influence the occurrence of metastasis. Patients with larger tumours tended to have a higher mortality (50 vs. 27% dead at 5
years). All patients presented clinically with pain and all but two complained of some sort of swelling. There was a trend
towards a higher Enneking Stage in patients presenting with a longer duration of symptoms (P=0.1). No difference in
survival was noted between patients undergoing surgery and chemotherapy and patients undergoing radiotherapy and
chemotherapy. Disease‐free survival was 100% at both 5 and 10 years for Enneking stage IIA, 56% at 5 and 10 years for
stage IIB and 0% at 5 years for stage III.

Discussion:This study re‐emphasises the potential importance of a diagnostic delay on outcome. Longer symptom duration
is associated with a higher Enneking stage at presentation. In turn a higher presenting stage results in a higher mortality.
Pain and swelling are prominent clinical findings at first presentation in upper extremity Ewing′s.
Universal (Non)service? Water Markets, Household Demand and the Poor in Urban Kenya
Authors: Gulyani Sumila , Talukdar Debabrata , Mukami Kariuki R.
Published: September 2005

Compared with the non-poor, just how inadequately are the urban poor served by the public utilities and private water providers? Based on a survey of 674 households, this paper examines current water use and unit costs in three Kenyan towns and also tests the willingness of the unconnected to pay for piped water or improved kiosk service. By examining the water use behaviour of poor and non-poor households, this study brings into question a long-standing notion in the literature-that only the poor are underserved, use little water and pay a lot for it. It also indicates that the standard prescription to 'price water and create water markets' is in itself insufficient to improve service delivery and that kiosks are not always a good solution for serving the poor.
Professionalisation or Hybridisation? Real Estate Brokers in Metro Cebu, the Philippines, during the Boom of the 1990s
Authors: Sajor Edsel E.
Published: September 2005

This paper addresses a gap in the literature about the effect of the late 20th-century property boom on real estate practitioners in a developing country city in the context of enhanced global integration. Taking a process approach, it examines professionalisation within the brokers' sector in Metro Cebu, the Philippines, by pairing theories on the sociology of professions on one hand and insights from economic sociology and studies of globalisation and local transformations on the other. It is argued that professionalisation initiated by local realtor boards and, to a certain degree, supported by major national property firms with international partners was a social closure, creating opportunities for monopoly for the licensed brokers, while marginalising the unlicensed. As part of their strategy, its advocates employed delegitimising discourses. Certain historical and locality-specific factors, however, seriously constrained it-namely: state weakness in bureaucratic regulation, the indispensability of local knowledge in brokering, the dominant bargaining characteristics of land transactions and clients' greater power in the market over licensed providers. What flourished instead were hybridised brokering networks and partnerships comprised of both professional and unlicensed agents, demonstrating the point that there is nothing intrinsically incompatible between informality, modernisation and a high-performing property market.
The Search for Community Cohesion: Key Themes and Dominant Concepts of the Public Policy Agenda
Authors: Robinson David
Published: September 2005

The community cohesion policy agenda in England emerged from the melee of explanation and advice that abounded in the aftermath of the street disturbances in Bradford, Burnley and Oldham in the summer of 2001. Various reports were published examining issues arising from the disturbances and providing recommendations for action. In 2002, the government responded with the launch of guidance on community cohesion for local authorities and established the Community Cohesion Unit, which was set the twin tasks of reviewing government policy and encouraging new learning and good practice in community cohesion at the local level. Housing was recognised as a key theme within this agenda, having been blamed in the various reports into the disturbances in 2001 for contributing towards high levels of residential segregation in many English towns, which were assumed to lead to different populations living, working and socialising separately. This paper explores this causal story, by first considering the particular conceptualisations of community and multiculturalism informing this new policy agenda, before moving on to question the integrity of four fundamental pillars on which the community cohesion agenda has been built: the assumed self-segregation of South Asian households within certain towns and cities; the role that housing policy and provision have played in reinforcing this process of self-segregation; the potential of housing interventions to reverse this process and to promote residential integration; and the curative benefits that will flow from greater interethnic residential mix.
Knowledge-based Industry Clusters: Evidenced by Geographical Patterns of Patents in Manufacturing
Authors: Koo Jun
Published: September 2005

Since Porter introduced his diamond model of industry clusters, clusters have become a mantra in economic development literature for many academics and professionals alike. There is, however, little consensus on how to define and identify industry clusters. Firms may co-locate looking for high quality suppliers, a large pool of skilled workers or local knowledge stock. Therefore, characteristics of industry clusters may differ according to the type of 'glue' that creates formal and informal ties and binds firms together. Most previous cluster studies investigated the first two factors, but knowledge still remains unexplored. This study presents an exploratory analysis of US industry clusters from the perspective of knowledge and its flows using a common data reduction technique and patent data. The study also examines geographical patterns of knowledge-based clusters in the US in terms of employment and patents. The analysis shows that the distributions of employment and patents are significantly associated. However, the degree of association varies cluster by cluster.
Countering the ‘new orthodoxy’ in educational research: a response to Phil Hodkinson
Authors: Hammersley Martyn
Published: September 2005

In a previous article, Phil Hodkinson argued that there are currently attempts to impose a methodological orthodoxy on educational research, one that is empiricist in character and privileges quantitative method. While agreeing with much of what he says, I take issue with key elements of his argument. I suggest that he presents too rosy a picture of the existing state of educational research, question his apparent advocacy of a laissez‐faire approach to its governance, and argue that he underplays the significant role that methodological rules can play in shaping the practice of research in desirable ways. I suggest that his approach is likely to reinforce paradigmatic fragmentation in the research community, and that this weakens any attempt to resist the internal and external pressures that currently threaten to damage or destroy educational research in the UK, and elsewhere.
Exclusion and excluded pupils
Authors: Munn Pamela , Lloyd Gwynedd
Published: September 2005

The voices of pupils excluded from school for disciplinary reasons are infrequently heard. This article draws together the views of a small sample of pupils, gathered over three separate projects, and identifies common themes. The pupils' voices are reported in the more general context of the role of schools in promoting social inclusion and in a review of patterns of disciplinary exclusion in Scotland. The article concludes that, while many individual schools and teachers try hard to sustain difficult and challenging pupils in mainstream school, the problems faced by both are intractable. The focus on school policy and practice distracts attention from broader social and economic problems requiring solutions.
Early Pathophysiological Features in Canine Renal Papillary Necrosis Induced by Nefiracetam
Authors: Tsuchiya Yoshimi , Yabe Koichi , Takada Sanae , Ishii Yoshikazu , Jindo Toshimasa , Furuhama Kazuhisa , Suzuki Kazuo T.
Published: September 2005

To ascertain the early pathophysiological features in canine renal papillary necrosis (RPN) caused by the neurotransmission enhancer nefiracetam, male beagle dogs were orally administered nefiracetam at 300 mg/kg/day for 4 to 7 weeks in comparison with ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), at 50 mg/kg/day for 5 weeks. During the dosing period, the animals were periodically subjected to laboratory tests, light-microscopic, immunohistochemical, and electron-microscopic examinations and/or cyclooxygenase (COX)-2 mRNA analysis. In laboratory tests, a decrease in urinary osmotic pressure and increases in urine volume and urinary lactate dehydrogenase (LDH) level were early biomarkers for detecting RPN. Light-microscopically, nefiracetam revealed epithelial swelling and degeneration in the papillary ducts in week 7, while ibuprofen displayed degeneration and necrosis in the papillary interstitium in week 5. In immunohistochemical staining with COX-2 antibody, nefiracetam elicited a positive reaction within interstitial cells around the affected epithelial cells in the papillary ducts (upper papilla) in week 7, and ibuprofen positively reacted within interstitial cells adjacent to the degenerative and/or necrotic lesions in week 5. Ultrastructurally, nefiracetam exhibited reductions of intracellular interdigitation and infoldings of epithelial cells in the papillary ducts, whereas ibuprofen showed no changes in the identical portions. Thus, the early morphological change in the papilla brought about by nefiracetam was quite different from that elicited by ibuprofen. By the renal papillary COX-2 mRNA expression analysis, nefiracetam exceedingly decreased its expression in week 4, but markedly increased it in week 7, suggesting an induction of COX-2 mRNA by renal papillary lesions. These results demonstrate that the epithelial cell in the papillary ducts is the primary target site for the onset of RPN evoked by nefiracetam.
Ultrastructural and Morphometrical Evaluation of the Parathyroid Gland in Iron-Lactate-Overloaded Rats
Authors: Matsushima Shuuichi , Tsuchiya Noriko , Fujisawa-Imura Kae , Hoshimoto Maruko , Takasu Nobuo , Torii Mikinori , Ozaki Kiyokazu , Narana Isao , Kotani Takao
Published: September 2005

Iron lactate was given to Sprague–Dawley rats intravenously at the dosage of 10 mg/kg/day and the early effects on the parathyroid gland were examined ultrastructurally along with the blood level of parathyroid hormone (PTH) after single, 3-day or 6-day administration. Blood levels of electrolytes and other parameters related to osteoclast dynamics were also measured by blood chemistry and histopathology. The plasma parathyroid hormone (PTH) level was elevated in the single and 3-day dosing group but was reduced in the 6-day dosing group. Histopathologically, an increase of osteoclasts in the primary spongiosa was observed in the 3- and 6-day dosing groups. Image analysis of the parathyroid gland revealed that the average area of the storage granule decreased during a experimental period, with the number of storage granules decreasing in the 3- and 6-day dosing group. The chief cells of the parathyroid gland were moderately atrophied in the 6-day dosing group. These results demonstrate that iron lactate immediately promotes discharge of PTH from the storage granules after the treatment and induces an increase of osteoclasts in the primary spongiosa. The findings collectively suggest a pathophysiological mechanism of iron lactate-induced osteopenia in rats.
Class & protest in Africa: New waves
Authors: Seddon David , Zeilig Leo
Published: September 2005

This article considers the relationship between working class struggle and popular protest in Africa over the last 40 years. We argue that the form and content of class relations which developed in the period of nationalist struggle and early ‘national development’ have been fundamentally restructured by the process of globalisation. From the late 1970s, a great wave of widespread popular protest and resistance was noted around the world, including Africa (Parfitt & Riley, 1994; Walton and Seddon, 1994). The strikes, marches, demonstrations and riots that characterised this wave of protest and resistance (often termed ‘bread riots’ or ‘IMF riots’) usually involved a variety of social groups and categories and did not always take place under a working class or trade union banner or with working class leadership – if this term is used in its narrow sense. A broader array of popular forces did, however, challenge not only the immediate austerity measures introduced as part of structural adjustment and ‘economic reform’, but also the legitimacy of the reforms themselves and even, sometimes, the governments that introduced them. They also frequently identified the international financial institutions and agencies that led this concerted effort to further enmesh ‘the developing world’ and the ordinary people who live there, into the uneven process of capitalist globalisation in the interests of major transnational corporations and the states that gain most from their operations.
Beating the odds: The quest for justice by South African asbestos mining communities1
Authors: McCulloch Jock
Published: September 2005

In March 2003 a small community group, ‘The Concerned People Against Asbestos (CPA)’ based at Prieska in the Northern Cape, won a court case in a foreign country. That case may change the way in which multinational corporations behave in the developing world. Until now the hidden costs of mining in Southern Africa have been paid for by labour. The CPA's victory may also help to end that injustice. It is usual to depict communities like Prieska as dis-empowered and impoverished. Despite its lack of resources the CPA was able to synchronise an elaborate game of small and big politics. The group's victory suggests that such communities have levels of political and organisation skill which given the right alignments can be irresistible.
E. E. Slutsky on William Petty—A Short Introduction
Authors: Barnett Vincent
Published: September 2005

E. E. Slutsky, the originator of the eponymous equation and part-inventor of the Slutsky-Yule effect, is perhaps the Soviet/Russian/Ukrainian economist most quoted by mainstream economists today, although his fame in the West rests on only two of his articles that have been translated into English. These are the 1915 article on the theory of consumer budgets, and the 1927 article on the random causes of business cycles. Many more papers remain available only in their original Russian versions, although a few were published first in other languages such as German. Presented here is a modest effort to bring more of Slutsky's work to an English-speaking audience. In a chronological bibliography of Slutsky's writings published in 1960, sandwiched between items four and six—“On the Criterion of Goodness of Fit of the Regression Lines” (1914) and “On the Theory of the Budget of the Consumer” (1915)—sits an item originally published in 1914, an “Essay on the Economic Views of William Petty.” This item is translated below.
Relationship of Fungal Vaginitis Therapy to Prior Antibiotic Exposure
Authors: Glover Douglas D. , Larsen Bryan
Published: September 2005

Objective: To address the putative association of antibiotic use and subsequent yeast vaginitis in a population of
non‐pregnant women.

Methods: Three hundred and sixteen women who received medical care in rural family medicine clinics enrolled
in this study. Participants were pre‐menopausal and non‐pregnant and were followed until they used a course of
antifungal therapy for vaginitis, became pregnant or moved from the catchment area. At entry subjects were free
of vaginitis symptoms and had taken no antibiotics for 30 days.
Patients were followed by repeated review of clinic records, hospital records and telephone or personal interviews.
Data collection included documentation of episodes of antifungal treatment for vulvovaginal candidiasis and
confirmed antibiotic treatment or credible history of antibiotic use prior to the use of antifungal therapy.
Physician‐reported uses of antibiotic and antifungal as well as patient‐reported uses of these were recorded.

Results: There were four reported cases of antifungal therapy following within a month of antibiotic use, in
contrast to 484 antibiotic uses not followed by antifungal use. If time of observation was extended to 6 months
from antibiotic use, there were 13 uses of antifungal therapy after antibiotics and 475 uses of antibiotics not
followed by antifungal therapy.

Conclusion: Our results cast doubt on the association of antibiotics as a putative cause of yeast vulvovaginitis.