bluuebunny/crossref_metadata_2025 huggingface dataset:
GROWTH OF ULTRATHIN Mn FILMS ON Ag(100)
Authors: SCHIEFFER P. , HANF M. C. , KREMBEL C. , TUILIER M. H. , GEWINNER G. , CHANDESRIS D.
Published: December 2003

Mn films with a thickness of one monolayer have been deposited, in ultrahigh vacuum, on a Ag (100) single crystal at room temperature, and analyzed by X-ray photoelectron diffraction (XPD) and surface extended X-ray absorption fine structure (SEXAFS). The strong enhancement of the X-ray photoelectron Mn2p3/2 signal along the Ag[1100] direction indicates that a substantial fraction of the Mn atoms is located within the second topmost atomic layer. The SEXAFS data demonstrate that the Mn – Ag and Mn – Mn first neighbor distances are the same as the Ag – Ag distances in the Ag lattice; as a result, the atoms occupy Ag sites on the fcc lattice. Comparison of the experimental data with FEFF calculations indicates that a superficial Mn – Ag alloy is formed. If the film is mildly (330 K) annealed, the contrast in the XPD Mn 2p 3/2 modulations versus polar angle increases and reaches a maximum value of 60%. As confirmed by single scattering simulations, these results mean that atomic place exchange occurs between Mn and Ag atoms, and eventually the second atomic plane of the sample is constituted mainly by Mn atoms, whereas the first atomic layer is a pure Ag plane, i.e. a buried atomic Mn monolayer is formed.
A SEXAFS STUDY OF ULTRATHIN Cr FILMS
Authors: COOK J. C. , DOWLING M. , SCHWARZACHER W. , McCASH E. M.
Published: December 2003

Three types of Cr films were grown on Pd(100) at different substrate temperatures. The film thickness was found to be the crucial parameter in determining the film structure; substrate temperature was found to make little difference to the surface EXAFS pattern observed. Films with a thickness greater than 6 monolayers (ML) of Cr were body-centered-cubic (bcc); those with a thickness less than 3 ML Cr appear to be face-centered-cubic (fcc) and those in between were initially bcc but after annealing to ~500 K produced an fcc-like SEXAFS pattern. The SEXAFS of both thin and medium films can be interpreted in terms of a Cr–Pd alloy on the surface.
SURFACE AND NEAR SURFACE STRUCTURE OF Fe–Co LAYERS BY SCATTERING-INTERFERENCE OF PRIMARY ELECTRONS
Authors: GAZZADI G. C. , DI BONA A. , BORGATTI F. , ROTA A. , VALERI S.
Published: December 2003

We studied the Co/Fe bi- and multilayer growth on Fe single crystal using the primary-beam diffraction modulated electron emission (PDMEE) technique. This approach enables a chemical selected structural characterization of both surface and buried layers and interfaces to be performed. Co growth on the Fe(001) surface was studied in the 3–70 ML coverage range. The transition from the initial epitaxial bcc phase of the Co film to the stable hcp phase was found to occur rather abruptly at 25–30 ML coverage, a value larger than previously reported in the literature. Subsequent Fe deposition on the Co hcp film recovers the bcc structure in the sandwiched Co layer. However, removal of the Fe epilayer by mild sputtering results again in an hcp Co film.
LEED STRUCTURE ANALYSES OF THE CLEAN AND FULLY HYDROGEN-COVERED W(110) and Mo(110) SURFACES
Authors: ARNOLD M. , SOLOGUB S. , HUPFAUER G. , BAYER P. , FRIE W. , HAMMER L. , HEINZ K.
Published: December 2003

We present a comparative low energy electron diffraction (LEED) structure analysis for the clean as well as hydrogen-saturated (110) surfaces of tungsten and molybdenum. Both clean surfaces exhibit some contraction of the first interlayer spacing, i.e. -3.1% for W and -4.0% for Mo, whereas deeper layer distances remain practically bulklike. The only structural consequence of a hydrogen monolayer adsorbed is the reduction of the first interlayer distance contraction to approximately half its value of the clean surface, i.e. to -1.7% for W and -2.0% for Mo . Our results give no evidence for an adsorbate-induced reconstruction of either surface and thus discard the widely accepted model of a hydrogen-induced lateral shift of the top layer of W (110). Hydrogen itself is found to be adsorbed in threefold-coordinated hollow sites at a height of about 1.2 Å and 1.1 Å above the first substrate layer of W and Mo , respectively.
HYDROGEN ADSORPTION ON THE (100) SURFACES OF RHODIUM, PALLADIUM AND SILVER
Authors: EICHLER A. , HAFNER J. , KRESSE G.
Published: December 2003

The adsorption of atomic hydrogen on the (100) surfaces of face-centered-cubic rhodium, palladium and silver has been studied using ab-initio density-functional calculations (including generalized gradient corrections). At the example of Rh(100) we present detailed investigations of the influence of the nonlocal corrections to the exchange-correlation functional on the stable geometries and the energies of adsorption. We also study the influence of the adsorbate on the relaxation of the substrate. Chemical trends are studied along the series Rh–Pd–Ag.
GROWTH OF Ag–O ROWS DURING OXIDATION OF Ag(110) SURFACE
Authors: PAGNOTTA D. , RUSPONI S. , RODER H. , BORAGNO C. , VALBUSA U.
Published: December 2003

The growth of Ag–O rows on a Ag(110) surface has been studied at room temperature by using a UHV-STM. The evolution of the typical (n×1) (n=8,7,…,2) structures has been analyzed as a function of O2 exposure. At the beginning, the (Ag–O) rows are randomly distributed on the surface. Increasing the exposure, many (n×1) phases coexist. The evolution of the system is due to a global rearrangement of the existing rows, which can move along the [Formula: see text] direction. A model for this mechanism is proposed.
BONDING OF POTASSIUM IN THE Ni(100)-(3×3)-(K+O) COADSORPTION SYSTEM
Authors: FINETTI P. , MURRAY S. J. , MERCER J. , JOHAL T. K. , ROBINSON A. W. , DHANAK V. R. , MCGRATH R. , HARTE S. P. , THORNTON G.
Published: December 2003

The bonding of potassium in the Ni (100)-(3×3)-( K + O ) coadsorption system has been investigated using surface extended X-ray absorption fine structure (SEXAFS). It is found that potassium bonds predominantly to oxygen rather than nickel. This imposes a useful constraint on structural models of this complex system.
REACTION PATH FOR THE DISSOCIATIVE ADSORPTION OF HYDROGEN ON THE (100) SURFACES OF FACE-CENTERED-CUBIC TRANSITION METALS
Authors: EICHLER A. , HAFNER J. , KRESSE G.
Published: December 2003

Detailed ab-initio local-density-functional studies of the potential-energy surfaces for the dissociative adsorption of hydrogen molecules on the (100) surfaces of face-centered-cubic transition and noble metals are presented. We show that the energetically most favorable reaction path is determined by quantum-mechanical steering effects arising from the formation and modification of covalent metal–hydrogen bonds. Variations of the local chemical reactivity with the filling of the d-band are discussed at the example of rhodium, palladium and silver surfaces.
ORGANOMETALLIC MICELLE COMPRISED OF GOLD MULTIPLY TWINNED PARTICLE AND SELF-ASSEMBLED THIOLS
Authors: TAKAMI T. , INO S.
Published: December 2003

We have demonstrated the method to stabilize gold particles by using the technique of self-assembled alkanethiol. Au and S peaks of the X-ray spectroscopy show that it consists of Au particle and alkanethiols. The chemical bond between Au and S is confirmed by the NMR spectrum. The typical size of the particle is less than 30 nm, observed by the scanning electron microscope. The predicted structure of the thiol-adsorbed particle is like a micelle, and we have named this particle the organometallic micelle.
STOCHASTIC RESONANCE IN BISTABLE AND EXCITABLE SYSTEMS: EFFECT OF NON-GAUSSIAN NOISES
Authors: FUENTES M. A. , TESSONE C. J. , WIO H. S. , TORAL R.
Published: November 2003

We analyze stochastic resonance in systems driven by non-Gaussian noises. For the bistable double well we compare the signal-to-noise ratio resulting from numerical simulations with some quasi-analytical results predicted by a consistent Markovian approximation in the case of a colored non-Gaussian noise. We also study the FitzHugh–Nagumo excitable system in the presence of the same noise. In both systems, we find that, as the noise departs from Gaussian behavior, there is a regime (different for the excitable and the bistable systems) in which there is a notable robustness against noise tuning since the signal-to-noise ratio curve broadens and becomes less sensitive to the actual value of the noise intensity. We also compare our results with some experiments in sensory systems.
CALCULATION OF SELECTED HIGHLY EXCITED VIBRATIONAL STATES OF POLYATOMIC MOLECULES BY THE DAVIDSON ALGORITHM
Authors: RIBEIRO FABIENNE , IUNG CHRISTOPHE , LEFORESTIER CLAUDE
Published: December 2003

We described an improved version of a modified Davidson scheme previously introduced (F. Ribeiro, C. Iung and C. Leforestier, Chem. Phys. Lett.362, 199 (2002)), aimed at computing highly excited energy levels of polyatomic molecules. The key ingredient is a prediagonalization-perturbation step performed on a subspace of a curvilinear normal modes basis set (including diagonal anharmonicities). The efficiency of the method is demonstrated by computing the lowest 350 vibrational states of A′ symmetry of the HFCO molecule. Also shown is the possibility to restrict the calculation to selected energy levels, based on their zero-order description. This State Filtered Diagonalization method is illustrated on a high overtone (7ν5) of the OCF bend, and on the few energy levels (20) which have been experimentally assigned up to 5000 cm -1 of excitation energy.
LANCZOS ALGORITHMS AND CROSS CORRELATION FUNCTIONS Cif(E)
Authors: KARLSSON HANS O.
Published: December 2003

Cross correlation (CC) functions Cif(E) play an important role in chemical physics. They appear in the description of reactive scattering, photo-dissociation, photo-electron spectroscopy and electron transfer to mention a few. In this paper, we discuss two methods based on the Lanczos algorithm to compute the CC function for several initial and final states at the same time, without diagonalization. The property of the coupled two-term recursions variant of the Lanczos algorithm that yields a decomposition [Formula: see text] of the tridiagonal Lanczos matrix is crucial. The first method, the quasi minimal-recursive residue generation method (QM-RRGM) is based on solving a set of linear equations whereas the second method is based on a band-Lanczos method. The computational cost is of the same order of magnitude for both methods and is given by the number of matrix-vector multiplications in the underlying Lanczos method. Only a small set of scalars needs to be updated each recursion. The methods are compared for a model problem, the continuum resonance Raman cross section for a collinear model of CH2IBr . Both methods shows similar convergence properties. By adding a pre-conditioner, the rate of convergence can be increased dramatically.
USING LEBEDEV GRIDS, SINE SPHERICAL HARMONICS, AND MONOMER CONTRACTED BASIS FUNCTIONS TO CALCULATE BENDING ENERGY LEVELS OF HF TRIMER
Authors: WANG XIAO-GANG , CARRINGTON TUCKER
Published: December 2003

We calculate energy levels of a six-dimensional bending Hamiltonian for HF trimer using a finite basis representation (FBR) in conjunction with the Lanczos eigensolver. We improve on our previous method [J. Chem. Phys.115, 9781 (2001)] using three techniques: (1) Lebedev's quadrature scheme is used to reduce the size of quadrature grid by a factor of 3.4. (2) Since the barrier separating the two equivalent versions of HF trimer is high and wide, it is a good approximation to confine the bending motion to one well by using sine spherical harmonics basis functions (this reduces the size of the basis by a factor of 8). (3) The sine spherical harmonic basis is contracted for each monomer to generate a very efficient basis. It is shown that the best approach is to combine all the three techniques.
DYNAMICS OF THE N(2D)+H2 REACTION ON THE $\tilde{X}^2 A^{\prime\prime}$ SURFACE, PROPAGATING REAL WAVE PACKETS WITH AN ARCCOS MAPPING OF THE HAMILTONIAN
Authors: DEFAZIO PAOLO , PETRONGOLO CARLO
Published: December 2003

We have investigated the dynamics of the title reaction with the Gray and Balint-Kurti approach, which propagates real wave packets (WP) under an arccos mapping of a scaled and shifted Hamiltonian. We have considered H 2 rotational quanta j=0 and 1 and obtained reaction probabilities using reactant coordinates and the flux analysis. We have calculated accurate reaction probabilities for total angular momentum quantum number J=0, centrifugal-sudden probabilities for J>0, cross sections, and the room temperature rate constant. The present cross sections are in good agreement with previous quasiclassical trajectory (QCT) results and the theoretical rate constant compares rather well with that observed. WP snapshots show that the reaction occurs via a C2v insertion mechanism, confirming previous QCT calculations.
A COMPARATIVE STUDY OF ITERATIVE CHEBYSHEV AND LANCZOS IMPLEMENTATIONS OF THE BOUNDARY INHOMOGENEITY METHOD FOR QUANTUM SCATTERING
Authors: ZHANG HONG , SMITH SEAN C.
Published: December 2003

We have recently developed a scaleable Artificial Boundary Inhomogeneity (ABI) method [Chem. Phys. Lett.366, 390–397 (2002)] based on the utilization of the Lanczos algorithm, and in this work explore an alternative iterative implementation based on the Chebyshev algorithm. Detailed comparisons between the two iterative methods have been made in terms of efficiency as well as convergence behavior. The Lanczos subspace ABI method was also further improved by the use of a simpler three-term backward recursion algorithm to solve the subspace linear system. The two different iterative methods are tested on the model collinear H+H 2 reactive state-to-state scattering.
The Community-Level Consequences of Seed Dispersal Patterns
Authors: Levine Jonathan M. , Murrell David J.
Published: December 2003

▪ Abstract  Because it lays the template from which communities develop, the pattern of dispersed seed is commonly believed to influence community structure. To test the validity of this notion, we evaluated theoretical and empirical work linking dispersal kernels to the relative abundance, distribution, dispersion, and coexistence of species. We found considerable theoretical evidence that seed dispersal affects species coexistence by slowing down exclusion through local dispersal and a competition-dispersal trade-off, yet empirical support was scant. Instead, most empirical investigations examined how dispersal affects species distribution and dispersion, subjects with little theory. This work also relied heavily on dispersal proxies and correlational analyses of community patterns, methods unable to exclude alternative hypotheses. Owing to the overall dichotomy between theory and empirical results, we argue that the importance of dispersal cannot be taken for granted. We conclude by advocating experiments that manipulate the seed dispersal pattern, and models that incorporate empirically documented dispersal kernels.
The Ecology and Evolution of Insect Baculoviruses
Authors: Cory Jenny S. , Myers Judith H.
Published: December 2003

▪ Abstract  Baculoviruses occur widely among Lepidoptera, and in some species of forest and agricultural insects, they cause epizootics in outbreak populations. Here we review recent developments in baculovirus ecology and evolution, in particular focusing on emerging areas of interest and studies relating to field populations. The expanding application of molecular techniques has started to reveal the structure of baculovirus populations and has highlighted how variable these pathogens are both genotypically and phenotypically at all levels from within individual hosts to among host populations. In addition, the detailed molecular knowledge available for baculoviruses has allowed the interpretation of gene functions across physiological and population levels in a way rarely possible in parasite-host systems and showed the diverse mechanisms that these viruses use to exploit their hosts. Analysis of the dynamic interactions between insects and baculoviruses, and their compatibility for laboratory and field experiments, has formed a basis for studies that have made a significant contribution to unraveling disease interactions in insect populations. In particular, manipulative studies on baculoviruses have been instrumental in developing an understanding of disease transmission dynamics. The results so far indicate that baculoviruses have the potential to be an excellent model for investigations of changes in virulence and resistance in fluctuating and stable host populations.
Data, Models, and Decisions in U.S. Marine Fisheries Management: Lessons for Ecologists
Authors: Rose Kenneth A. , Cowan James H.
Published: December 2003

▪ Abstract  Ecological and fisheries approaches to population modeling share many common tools and issues, yet they have developed quite independently over the past decades. The Sustainable Fisheries Act has pushed fisheries modeling into forecasting for management decision-making, which is an area where ecological modeling appears to be headed. We summarize how marine fisheries are managed in the United States, and how data and models are used to make the required forecasts. The recent management deliberations of red grouper in the Gulf of Mexico provide a case study of the sensitive relationship among data, models, and management decisions. We use the U.S. marine fisheries experience and the case study to discuss six lessons that ecologists should consider as they proceed toward forecasting for management. The need for forecasting is accelerating both in ecology and fisheries, while the margin for mistakes is getting smaller.
Partitioning of Time as an Ecological Resource
Authors: Kronfeld-Schor Noga , Dayan Tamar
Published: December 2003

▪ Abstract  Animal species have evolved different diel activity rhythms that are of adaptive value. Theory suggests that diel temporal partitioning may facilitate coexistence between competitors and between predators and prey. However, relatively few studies demonstrate a temporal shift that is predation- or competition-induced. Recorded shifts are usually within the preferred activity phase of animal species (day or night), although there are some inversions to the opposite phase cycle. Temporal partitioning is not perceived as a common mechanism of coexistence. This rarity has been variously ascribed to theoretical considerations and to the rigidity of time-keeping mechanisms, as well as to other physiological and anatomical traits that may constrain activity patterns. Our decade-long study of spiny mice of rocky deserts demonstrates that, while different factors select for activity patterns, endogenous rhythmicity may be an evolutionary constraint.
Extra-Pair Paternity in Birds: Causes, Correlates, and Conflict
Authors: Westneat David F. , Stewart Ian R.K.
Published: December 2003

▪ Abstract  Extra-pair paternity (EPP) is extremely variable among species of birds, both in its frequency and in the behavioral events that produce it. A flood of field studies and comparative analyses has stimulated an array of novel ideas, but the results are limited in several ways. The prevailing view is that EPP is largely the product of a female strategy. We evaluate what is known about the behavioral events leading to EPP and find the justification for this view to be weak. Conflict theory (derived from selection theory) predicts that adaptations in all the players involved will influence the outcome of mating interactions, producing complex and often highly variable patterns of behavior and levels of EPP. Data support some of these predictions, but alternative hypotheses abound. Tests of predictions from conflict theory will require better information on how males and females encounter one another, behave once they have met, and influence fertilization once insemination has occurred.
Genetic Variation in Rare and Common Plants
Authors: Cole Christopher T.
Published: December 2003

▪ Abstract  Isozyme variation in 247 plant species is summarized as 57 generic-level comparisons of rare and common species. All species-level measures of variation (Ps, As, APs, Hes) and mean population-level measures (Pp, Ap, APp, Hep, and Ho) show reductions significant at the p < 0.001 level, but FISand FSTdid not differ significantly, reflecting the similarity of breeding system in congeneric species and disparate ranges often sampled for rare and common species. The reduction in gene flow (Nm) among populations of rare species was significant when estimated from FST, but not when estimated from private alleles. Species monomorphic for isozymes are predominantly endemic and self-fertile. Although census populations of virtually all rare species are higher than levels at which theory would predict genetic erosion, and higher than levels protected by the U.S. Endangered Species Act (ESA), rare plants evidently have more significant reductions in genetic variation and gene flow than have been recognized previously.
Effects of biological variations on platelet count in healthy subjects in China
Authors: Yang Jing , Lu Xiaojun , Okada Tokuhiro , Kondo Tamiaki , Ruan Changgeng , Wu Yun , Xin Xiaomin , Peng Liming
Published: December 2003

The effects of biological variations on platelet counts were investigated in 694 healthy subjects aged 18 to 60 years living in three cities including Chengdu (Sichuan Province), Suzhou (Jiangsu Province) and Harbin (Heilongjang Province) in China. Platelet counts in healthy subjects were significantly lower in Chengdu (52∼202 X 109/L) and Suzhou (60∼259 X 109/L) than in Harbin (154∼348 X 109/L)(p <0.0001), but the mean platelet volume (MPV) determined concurrently was negatively correlated with platelet count, the MPV values were significantly higher in Chengdu (11.8∼15.6 fl) and Suzhou (10.9∼15.8 fl) than in Harbin (9.5∼12.9 fl) (p < 0.0001). Platelet counts were significantly higher in summer (73∼289 X 109/L) than in winter (52∼202 X 109/L) (p <0.0001), but the MPV values were lower in summer (11.2∼14.7 fl) than in winter (11.8∼15.6 fl) (p <0.05) in Chengdu. Platelet associated immunoglobulin (PA-IgG) in Chengdu was revealed to be significantly higher in the low platelet count group (<150 X 109/L, 13.5 ± 7.1 ng/107 PLT) than in the normal platelet count group (≥150 X 109/L, 8.3 ± 2.7 ng/107 PLT)(p <0.0001). Similar results were observed in Suzhou for the reticulated platelet ratio, which was significantly higher in the low platelet count group (19.5 ± 7.1%) than in the normal platelet count group (11.6 ± 2.7%)(p <0.01). The bleeding time in Chengdu showed a significantly longer time in the low platelet count group (8.6 ± 2.3 min) than in the normal platelet count group (6.0 ± 1.2 min)(p <0.01). With regard to the effects of lipids on platelet counts, the HDL values were significantly higher in the normal platelet count group (1.60 ± 0.76 mmol/L) than the low platelet count group (1.23 ± 0.31 mmol/L) (p <0.01); but no significant differences in cholesterol and triglycerides values between the normal and low platelet count groups (p >0.05) were recorded. These findings suggest that the platelet counts could be greatly influenced in healthy subjects by biological variations such as geographical, seasonal, and lipid variations.
Sequence of the rat factor VIII cDNA
Authors: Geisen Christof , Seifried Erhard , Oldenburg Johannes , Watzka Matthias
Published: December 2003

FactorVIII acts as an essential compound of the tenase complex of the coagulation system. Herein we report the cDNA of the rat factor VIII. The rat cDNA comprises 6777 nucleotides and encodes a protein of 2258 amino acids, 61 amino acids less than mouse and 92 amino acids less than human factor VIII. The overall identity compared to human cDNA is 61% on the cDNA and 51% on the amino acid level. In cDNA, highest levels of sequence identity can be observed in the A and C domains (ranging between 68% and 73%), whereas B domain and the small acidic regions are more divergent (34%-49%). Compared to mouse and human most sites for posttranslational modifications such as sulfatation and glycosylation as well as thrombin and protein C cleavage sites are conserved in rat. Alternative transcripts lacking exon 17 and/or comprising additional 26 bp due to alternative splicing of exon 20 were found. Furthermore, 13 polymorphisms (seven in exon 14, one in exon 20, 23, 24, and 25, two in the 3’UTR) three of which lead to an amino acid exchange could be detected. Our findings might provide new insights into the structure-function analysis of the factor VIII protein and might prove useful for future animal models addressing the function of factor VIII.
Use of pharmacogenetics and clinical factors to predict the maintenance dose of warfarin
Authors: Eby Charles , Milligan Paul , Banet Gerald , Duncan Jill , McLeod Howard , Gage Brian
Published: December 2003

Knowledge of pharmacogenetics may help clinicians predict their patients’ therapeutic dose of warfarin, thereby decreasing the risk of bleeding during warfarin initiation. Our goal was to use pharmacogenetics to develop an algorithm that uses genetic, clinical, and demographic factors to estimate the warfarin dose a priori. We collected a blood sample, demographic variables, laboratory values, smoking status, names of medications, and dietary history from 369 patients who were taking a maintenance dose of warfarin. Using polymerase chain reaction, we genotyped each participant for the presence of 8 polymorphisms in the cytochrome P450 2C9 system. Using multiple regression, we quantified the association between warfarin dose and all factors. Advanced age, lower body surface area (BSA), and the presence of cytochrome P450 2C9 *2 or *3 single nucleotide polymorphisms were strongly associated (P < 0.001) with lower warfarin dose: the maintenance dose decreased by 8% per decade of age, by 13% per standard deviation decrease in BSA, by 19% per 2C9*2 allele, and by 30% per 2C9*3 allele. Warfarin doses were 29% lower in patients who took amiodarone, 12% lower in patients who took simvastatin, 21% lower in patients whose target INR was 2.5 rather than 3.0, and 11% lower in white rather than African-American participants (P < 0.05 for these comparisons). An algorithm that included these factors and one of borderline significance (sex), explained 39% of the variance in the maintenance warfarin dose. Use of this pharmacogenetic model had potential to prevent patients from being overdosed when initiating warfarin: we estimate that only 24 (6.5%) patients would have been overdosed by >2 mg/day with pharmacogenetic dosing compared to 59 (16%) patients who would have been overdosed if they had been prescribed the empirical dose of 5 mg/day (P < 0.001). In conclusion, the maintenance warfarin dose can be estimated from demographic, clinical, and pharmacogenetic factors that can be obtained at the time of warfarin initiation.
Plasma membrane Ca2+-ATPase (PMCA) translocates to filopodia during platelet activation
Authors: Whiteheart Sidney , Dean William
Published: December 2003

The plasma membrane Ca2+-ATPase (PMCA) plays an essential role in maintaining low cytosolic Ca2+ in platelets. Recently we demonstrated that PMCA is recruited to the cytoskeleton by interacting with PDZ domains. In the present study we determined the subcellular localization of PMCA using immunofluorescence microscopy. In resting platelets PMCA was distributed over the entire plasma membrane. Upon activation with thrombin, PMCA was found in filopodia adjacent to the actin cytoskeleton. PMCA translocation to filopodia was prevented by a peptide containing the last 10 residues of PMCA4b, the predominate isoform of PMCA in platelets, which contains a known PDZ domain-binding motif and was previously shown to block association of PMCA with the cytoskeleton. Incorporation of the PMCA C-terminal peptide did not affect the rate or extent of platelet aggregation, but significantly enhanced the rate of clot retraction. These results show that PMCA association with the cytoskeleton during platelet activation results in translocation of this Ca2+-pump to filopodia and that this association may affect later stages of platelet activation. The consequence of PMCA translocation to filopodia is likely a reduction in the local concentration of free Ca2+ in these structures resulting in regulation of the rate of clot retraction.
Thioredoxin
Authors: Yamawaki Hideyuki , Haendeler Judith , Berk Bradford C.
Published: November 2003

The thioredoxin (TRX) system (TRX, TRX reductase, and NADPH) is a ubiquitous thiol oxidoreductase system that regulates cellular reduction/oxidation (redox) status. The oxidation mechanism for disease pathogenesis states that an imbalance in cell redox state alters function of multiple cell pathways. In this study, we review the essential role for TRX to limit oxidative stress directly via antioxidant effects and indirectly by protein-protein interaction with key signaling molecules, such as apoptosis signal-regulating kinase 1. We propose that TRX and its endogenous regulators are important future targets to develop clinical therapies for cardiovascular disorders associated with oxidative stress.
Proteomic Approaches to Analyze the Dynamic Relationships Between Nucleocytoplasmic Protein Glycosylation and Phosphorylation
Authors: Whelan Stephen A. , Hart Gerald W.
Published: November 2003

O-linked β-
N
-acetylglucosamine (O-GlcNAc) is both an abundant and dynamic posttranslational modification similar to phosphorylation that occurs on serine and threonine residues of cytosolic and nuclear proteins in all metazoans and cell types examined, including cardiovascular tissue. Since the discovery of O-GlcNAc more than 20 years ago, the elucidation of O-GlcNAc as a posttranslational modification has been slow, albeit similar to the rate of acceptance of phosphorylation, because of the lack of tools available for its study. Identifying O-GlcNAc posttranslational modifications on proteins is a major challenge to proteomics. The recent development of mild β-elimination followed by Michael addition with dithiothreitol has significantly improved the site mapping of both O-GlcNAc and
O
-phosphate in functional proteomics. β-Elimination followed by Michael addition with dithiothreitol facilitates the study of the labile O-GlcNAc modification in the etiology of disease states. We discuss how recent technological innovations will expand our present understanding of O-GlcNAc and what the implications are for diabetes and cardiovascular complications.
Globalization and food security: novel questions in a novel context?
Authors: Young E. M.
Published: December 2003

This paper argues that analyses of food security highlight fundamental contradictions at the heart of the globalization project. It examines the concept of food security and evaluates how national strategies to promote it have been undermined by economic liberalization since the 1980s. It finds that unless current policies are drastically reformed, traditional patterns of food insecurity will continue to hinder development in the South. It also identifies new problems of malnutrition, in the form of obesity, that are set to ravage populations in the North and South. The diffusion of obesogenic environments is allied to globalization and presents a new challenge for public health policy. Globalization and health are inherently linked and, by reconceptualizing the concept of food security, this paper draws attention to this link and argues that such connections should inform national policy in an era of globalization. Imbalances in power throughout the food chain help explain food insecurity in the past and present. The paper concludes that, as in the past, purposeful public intervention is required to promote food security.
A Rapid and Efficient Microwave-Assisted Synthesis of Substituted 3-Phenylpropionic Acids from Benzaldehydes in Minutes
Authors: Sharma Anuj , Joshi Bhupendra P , Sinha Arun K
Published: November 2003

A convenient, inexpensive, and efficient synthesis of 3-phenylpropionic acids (1a–1f) by reacting benzaldehyde (2a–2f) and malonic acid in acetic acid and piperidine into cinnamic acid (3a–3f) in 77 to 89% followed by its reduction with PdCl2 in the biphase of formic acid and aqueous sodium hydroxide is reported under microwave irradiation which utilizes short reaction time ranging 5 to 7 min to provide 1a–1f in moderate to high yield (69–86%) depending upon methoxy, methylenedioxy, and hydroxy groups present at the phenyl ring.
Combined Multiple Claisen Rearrangement and Ring-closing Metathesis as a Route to Naphthalene, Anthracene, and Anthracycline Ring Systems
Authors: Chattopadhyay Shital K , Pal Benoy K , Maity Susama
Published: November 2003

A new route involving double Claisen rearrangement of a suitable 1,4-diallyloxyarene system followed by ring-closing metathesis of the resulting diene has been developed for the synthesis of various benzannulated cyclohexenes. An important demonstration of this methodology is the construction of the tetracyclic quinophenolic ring system of the clinically important anthracyclines.
A Convenient Method for the Synthesis of α-Imidostyrenes from Styrenes and Imides via Diphenylstyrylsulfonium Salts
Authors: Yamanaka Hiroyuki , Mukaiyama Teruaki
Published: November 2003

Styrenes having a hydrogen atom at the α-position reacted with diphenyl(trifluoromethanesulfonyloxy)sulfonium triflate (1) to form diphenylstyrylsulfonium triflates 2 that were in turn converted into the corresponding α-imidostyrenes on treatment with sodium or potassium salts of cyclic imides.
Effects of Surface Passivation on Silicon Nanoparticle Photoluminescence
Authors: Harwell David E , Croney John C , Qin Wenjie , Thornton John T , Day Jason H , Hajime Evan K , Jameson David M
Published: November 2003

Silicon nanoparticles were produced by a relatively low temperature (164 °C), solution-phase synthesis. The particles exhibit UV to blue photoluminescence (PL) which varied with excitation wavelength. The average lifetimes, excited at 300 nm, ranged from 4.4 to 5.9 ns. The mean particle diameter, determined by atomic force microscopy, was ≈1.08 nm. The PL spectra of particles passivated with methoxy or butyl groups were blue-shifted with respect to those passivated with hydroxy groups.
A tele-otology course for primary care providers
Authors: Eikelboom Robert H , Weber Susanna , Atlas Marcus D , Dinh Quan , Mbao Mathew N , Gallop Mark A
Published: December 2003

summary

The shortage of otolaryngologists and the high incidence of ear disease in remote areas are major problems in Australia. We have developed a multimedia course for primary care providers that incorporates material about ear anatomy and physiology, ear disease, video-otoscopy and telemedicine software. The computer-based course was followed by a practical one-day course. A multiple-choice test was given to participants before and at the end of the course and a form was used to record feedback. The course was conducted with 30 aboriginal health workers. The participants were able to obtain images of reasonable to good quality after a short period of training. There was an average improvement of about 25% in the test scores, and the feedback regarding the course was extremely positive. The CD-ROM and the Website provide a valuable resource to assist primary care providers in their care of patients with ear disorders.
Organizational readiness for telemedicine: Implications for success and failure
Authors: Jennett Penny , Yeo Maryann , Pauls Monica , Graham Jennifer
Published: December 2003

summary

The use of telemedicine brings about change in health-care organizations and opens up new possibilities for service delivery. The organizational environment is often crucial in determining whether or not telemedicine applications will be successful. To examine the concept of ‘organizational readiness for telemedicine’ as a factor to explain why telemedicine initiatives succeed or fail, the results were used of interviews with key informants, conducted in two studies: the Alliance for Building Capacity project and the National Initiative for Telehealth guidelines project. The data indicate that organizational readiness for telemedicine is a multifaceted concept that is related to planning and the workplace environment. A greater understanding of the factors within organizational readiness could help to avoid costly implementation errors. ‘Readiness’ needs to be systematically assessed and is important for long-term success.
Managing risk in telemedicine
Authors: Mccrossin Robert
Published: December 2003

summary

Whenever something novel is introduced there are problems of implementation and operation, which may be formally expressed as risks. A comprehensive methodology has been developed to assess these risks, but it has not yet been extensively applied in the health sector. Until now, health has appropriately concentrated on the detection and reduction of clinical incidents in established services. However, there is strategic value in looking more broadly at the process of risk management. This is relevant to risk management in telemedicine.
The diagnostic reliability of Internet-based observational kinematic gait analysis
Authors: Russell Trevor G , Jull Gwendolen A , Wootton Richard
Published: December 2003

summary

We investigated the accuracy and reliability of observational kinematic gait assessments performed via a low-bandwidth Internet link (18 kbit/s) and a higher-speed Internet link (128 kbit/s). Twenty-four subjects were randomized to either bandwidth group. Gait was assessed with the Gait Assessment Rating Scale (GARS) in the traditional manner, which is from video-recordings, and with repeated measurements via the online method. Online assessment was found to provide as accurate a measure of gait performance as the traditional assessment (limits of agreement51 GARS point; intraclass correlation coefficient, ICC= 0.96) regardless of the speed of the Internet connection. The online assessment also demonstrated high intra-rater (ICC= 0.96) and inter-rater (ICC= 0.92) reliability. Low-bandwidth telerehabilitation applications appear to be feasible via the Internet.
International medical education between Hawaii and Thailand over Internet2
Authors: Vincent Dale S , Berg Benjamin W , Hudson Donald A , Chitpatima Suwicha T
Published: December 2003

summary

International medical education sessions have been successfully conducted by videoconferencing using Internet2. The sessions were between two tertiary care medical centres, in Honolulu and Bangkok. However, video quality was lower than for similar sessions using ISDN and audience satisfaction was less. The main reasons for the lower quality were network congestion and bandwidth allocation by the videoconferencing equipment. Software to ensure quality of service is available, but is not easy to implement. There were also network security problems and the costs were high. Our international videoconferences averaged 40–50 hours per year, an activity level at which connection costs were lower for ISDN than for Internet2. It appears that Internet2 videoconferencing for medical education is best reserved for academic institutions that have other high-bandwidth network requirements.
Acting on intentions: The role of anticipated regret
Authors: Abraham Charles , Sheeran Paschal
Published: December 2003

Three studies tested the hypothesis that anticipated regret (AR) increases consistency between exercise intentions and behaviour. Study 1 employed a longitudinal survey design (N = 384). Measures specified by the theory of planned behaviour, past behaviour, and AR were used to predict self‐reported exercise behaviour 2 weeks later. AR moderated the intention‐behaviour relationship such that participants were most likely to exercise if they both intended to exercise and anticipated regret if they failed to exercise. Study 2 used an experimental design to examine the effect of focusing on AR prior to reporting intentions (N = 229). Exercise was measured 2 weeks later and the AR‐focus manipulation was found to moderate the intention‐behaviour relationship in a similar manner to that observed in Study 1. In Study 3 (N = 97), moderation was replicated and was shown to be mediated by the temporal stability of intention.
Committed to (un)equal opportunities?: ‘New ageism’ and the older worker
Authors: McVittie Chris , McKinlay Andy , Widdicombe Sue
Published: December 2003

In recent years the principle of equality of opportunity in employment has been widely promoted as a means of addressing the marginalization of various groups of workers, including older workers. Evidence suggests, however, that equal opportunities have not improved prospects for older workers. The present study employs discourse analysis to examine a variety of accounts of those responsible for employment within a number of organizations. Analysis shows that these accounts are rhetorically oriented towards potential attributions of age discrimination. As evidence of a non‐discriminatory stance, participants attend to possible shortcomings in written policies by making explicit their organizations' equal opportunity practices. In describing their workforces as comprising predominantly younger employees, however, they make only implicit reference to practices involving older workers. When they account for the apparent age imbalances in their workforces, they attribute these imbalances to factors outwith their control so that the organization's practices become completely ‘invisible’. The contrast between this ‘invisibility’ and explicit claims to be committed to equal opportunities allows participants to position themselves as non‐discriminating employers and at the same time justifies the marginalization of older workers.
Feeling bad, but satisfied: The effects of upward and downward comparison upon mood and marital satisfaction
Authors: Buunk Bram P. , Ybema Jan F.
Published: December 2003

This study in a sample of 135 women from rural areas examined the effects of social comparison with the marriage of another woman upon mood, identification and relationship evaluation. The comparison target constituted either an upward or a downward comparison, characterized by either high or low effort. Upward targets evoked a more positive mood, and a less negative mood than downward targets, while, in contrast, the evaluation of one's own relationship was more positive after being exposed to a downward target than after being exposed to an upward target. Upward targets and high‐effort targets instilled more identification than downward and low‐effort targets. A higher level of marital quality led to less identification with the downward targets and to more identification with the upward targets, particularly with targets who put a high degree of effort in the relationship. Identification mediated the association between marital quality and positive mood following upward comparison. The present study suggests that upward and downward comparison may have effects upon mood that are opposite to those upon self‐evaluation, and demonstrates that happily married individuals may through identification with upward targets derive positive affective consequences from exposure to such targets.
Korean Marketing in China: An Exploratory Analysis of Strategy–Performance Relationships
Authors: Han C. Min , Kim Jung Min
Published: December 2003

The authors attempt to identify the types of marketing strategies that Korean marketers employ in China and investigate the strategies’ relationships with market performance. The authors expect Korean marketing strategies in China to differ from those of Western multinational corporations. Data were collected from surveys of managers of 86 Korean firms. The results identify four groups of firms with distinctive marketing strategies, including firms pursuing a localization strategy, those emphasizing product competitiveness, those pursuing a medium price–quality positioning strategy, and those passively selling quality products at high prices. In addition, the analysis suggests that Korean firms emphasizing product competitiveness have superior market performance, whereas firms pursuing localization show poor performance. Conversely, Korean firms pursuing the medium price–quality positioning strategy with an emphasis on value for money exhibit moderately good performance. Finally, the authors also discuss managerial implications pertaining to appropriate marketing strategies and tactics for Korean marketers.
International Standardization Strategies: The Experiences of Australian and New Zealand Firms Operating in the Greater China Markets
Authors: Chung Henry F.L.
Published: December 2003

Drawing on the findings of previous theoretical and empirical studies, this study proposes two frameworks for examining standardization strategies in home–host and intermarket scenarios. For the first time, internal and external factors, extent of standardization, program and process, performance, and home–host/intermarket scenarios are included in one study. In its examination of the proposed research frameworks, the study relies on the experiences of 146 Australian and New Zealand firms operating in the Greater China markets. Factors identified as significantly related to the selection of standardized marketing strategies in the home–host scenario include product type, consumer behavior, marketing infrastructure, political environment, and firm size. Factors suggested by the multivariate regression analysis as significantly related to standardized strategies in the intermarket scenario are product type, international business experience, competitive environment, political and legal aspects, and firm size. For the first time, it is suggested that the standardization of distribution and product strategies has an effect on firm performance in the intermarket scenario.
The Effect of Export Marketing Capabilities on Export Performance: An Investigation of Chinese Exporters
Authors: Zou Shaoming , Fang Eric , Zhao Shuming
Published: December 2003

The primary purpose of this article is to investigate the effect of export marketing capabilities on export performance. Drawing on the resource-based view, the authors develop a model that links an exporter's product development capability, distribution capability, communication capability, and pricing capability with its positional advantages (low-cost advantage and branding advantage) and its performance in the export market. On the basis of a survey of Chinese export ventures, the authors find general support for their proposed model. The authors discuss the theoretical and managerial implications of their findings.
Does the Firm's Technology and Marketing Profile Affect Foreign Market Entry?
Authors: Bradley Frank , Gannon Michael
Published: December 2003

The authors examine the influence of the firm's technology and marketing profile on foreign market entry mode by testing hypotheses based on data from 105 firms in four European countries. Four technology and marketing variables were the most important: (1) the firm's generic marketing strategy—market concentration versus diversification, (2) demand uncertainty—the position in the life cycle of the firm's principal product, (3) transaction costs—transaction uncertainty and research and development, and (4) value added—product patents. The authors suggest ways managers may be assisted in their foreign market entry decisions on the basis of their firms’ technology and marketing profile.