bluuebunny/crossref_metadata_2025 huggingface dataset:
Mass-Dependent and -Independent Fractionation of Hg Isotopes by Photoreduction in Aquatic Systems
Authors: Bergquist Bridget A. , Blum Joel D.
Published: September 2007

Mercury (Hg) isotopes can be used as tracers of Hg biogeochemical pathways in the environment. The photochemical reduction of aqueous Hg species by natural sunlight leads to both mass-dependent fractionation (MDF) of Hg isotopes and mass-independent fractionation (MIF) of the odd-mass isotopes, with the relation between the MIF for the two odd isotopes being distinct for different photoreduction pathways. Large variations in MDF and MIF are observed in fish and provide new insights into the sources and bioaccumulation of Hg in food webs. MIF in fish can also be used to estimate the loss of methylmercury via photoreduction in aquatic ecosytems.
The Flagellar Muramidase from the Photosynthetic Bacterium
Rhodobacter sphaeroides
Authors: de la Mora Javier , Ballado Teresa , González-Pedrajo Bertha , Camarena Laura , Dreyfus Georges
Published: September 2007

We have characterized open reading frame RSP0072, which is located within the
flgG
operon in
Rhodobacter sphaeroides
. The amino acid sequence analysis of this gene product showed the presence of a soluble lytic transglycosylase domain. The deletion of the N-terminal region (90 amino acids) of the product of RSP0072 yields a leaky nonmotile phenotype, as determined by swarm assays in soft agar. Electron micrographs revealed the lack of flagella in mutant cells. The purified wild-type protein showed lytic activity on extracts of
Micrococcus luteus
. In contrast, no lytic activity was observed when the residues E57 or E83 were replaced by alanine. Affinity blotting suggests that the protein encoded by RSP0072 interacts with the flagellar rod-scaffolding protein FlgJ, which lacks the muramidase domain present in FlgJ of many bacteria. We propose that the product of RSP0072 is a flagellar muramidase that is exported to the periplasm via the Sec pathway, where it interacts with FlgJ to open a gap in the peptidoglycan layer for the subsequent penetration of the nascent flagellar structure.
Effect of Viral Load on the Outcome of Herpes Zoster
Authors: Quinlivan M. L. , Ayres K. , Ran H. , McElwaine S. , Leedham-Green M. , Scott F. T. , Johnson R. W. , Breuer J.
Published: September 2007

Varicella-zoster virus (VZV) is a member of the
Herpesviridae
family, primary infection with which causes varicella, more commonly known as chicken pox. Characteristic of members of the alphaherpesvirus subfamily, VZV is neurotropic and establishes latency in sensory neurons. Reactivation of VZV causes herpes zoster, also known as shingles. The most frequent complication following zoster is chronic and often debilitating pain called postherpetic neuralgia (PHN), which can last for months after the disappearance of a rash. During episodes of acute zoster, VZV viremia occurs in some, but not all, patients; however, the effect of the viral load on the disease outcome is not known. Here we describe the development of a highly specific, sensitive, and reproducible real-time PCR assay to investigate the factors that may contribute to the presence and levels of baseline viremia in patients with zoster and to determine the relationship between viremia and the development and persistence of PHN. VZV DNA was detected in the peripheral blood mononuclear cells (PBMCs) of 78% of patients with acute zoster and in 9% of healthy asymptomatic blood donors. The presence of VZV in the PBMCs of patients with acute zoster was independently associated with age and being on antivirals but not with gender, immune status, extent of rash, the age of the rash at the time of blood sampling, having a history of prodromal pain, or the extent of acute pain. Prodromal pain was significantly associated with higher baseline viral loads. Viral load levels were not associated with the development or persistence of PHN at 6, 12, or 26 weeks.
Influenza Virus-Induced Type I Interferon Leads to Polyclonal B-Cell Activation but Does Not Break Down B-Cell Tolerance
Authors: Woods Anne , Monneaux Fanny , Soulas-Sprauel Pauline , Muller Sylviane , Martin Thierry , Korganow Anne-Sophie , Pasquali Jean-Louis
Published: September 2007

The link between infection and autoimmunity is not yet well understood. This study was designed to evaluate if an acute viral infection known to induce type I interferon production, like influenza, can by itself be responsible for the breakdown of immune tolerance and for autoimmunity. We first tested the effects of influenza virus on B cells in vitro. We then infected different transgenic mice expressing human rheumatoid factors (RF) in the absence or in the constitutive presence of the autoantigen (human immunoglobulin G [IgG]) and young lupus-prone mice [(NZB × NZW)F1] with influenza virus and looked for B-cell activation. In vitro, the virus induces B-cell activation through type I interferon production by non-B cells but does not directly stimulate purified B cells. In vivo, both RF and non-RF B cells were activated in an autoantigen-independent manner. This activation was abortive since IgM and IgM-RF production levels were not increased in infected mice compared to uninfected controls, whether or not anti-influenza virus human IgG was detected and even after viral rechallenge. As in RF transgenic mice, acute viral infection of (NZB × NZW)F1mice induced only an abortive activation of B cells and no increase in autoantibody production compared to uninfected animals. Taken together, these experiments show that virus-induced acute type I interferon production is not able by itself to break down B-cell tolerance in both normal and autoimmune genetic backgrounds.
Occurrence of the European Subgroup of Subtype I BK Polyomavirus in Japanese-Americans Suggests Transmission outside the Family
Authors: Yogo Yoshiaki , Zhong Shan , Suzuki Makoto , Shibuya Ayako , Kitamura Tadaichi
Published: September 2007

To examine the mode of transmission of BK polyomavirus (BKV), urine samples were collected from Japanese-Americans in Los Angeles and from other southern Californians. Subtype I was the main subtype found in samples from both groups. The subtype I subgroup Ib-2, which is predominant in Europe, was the primary subgroup detected in second-generation Japanese-Americans and in southern Californians; however, the Ic subgroup prevalent in native Japanese was rare in these populations. Since the European subgroup (Ib-2) predominated in the studied geographic area, the findings demonstrate that transmission outside the family is common in the spread of BKV, unlike previous findings for JC polyomavirus.
Mutations in Envelope gp120 Can Impact Proteolytic Processing of the gp160 Precursor and Thereby Affect Neutralization Sensitivity of Human Immunodeficiency Virus Type 1 Pseudoviruses
Authors: Blay Wendy M. , Kasprzyk Theresa , Misher Lynda , Richardson Barbra A. , Haigwood Nancy L.
Published: September 2007

The design of an efficient human immunodeficiency virus (HIV) immunogen able to generate broad neutralizing antibodies (NAbs) remains an elusive goal. As more data emerge, it is becoming apparent that one important aspect of such an immunogen will be the proper representation of the envelope protein (Env) as it exists on native virions. Important questions that are yet to be fully addressed include what factors dictate Env processing, how different Env forms are represented on the virion, and ultimately how these issues influence the development and efficacy of NAbs. Recent data have begun to illuminate the extent to which changes in gp41 can impact the overall structure and neutralizing sensitivity of Env. Here, we present evidence to suggest that minor mutations in gp120 can significantly impact Env processing. We analyzed the gp120 sequences of 20
env
variants that evolved in multiple macaques over 8 months of infection with simian/human immunodeficiency virus 89.6P. Variant gp120 sequences were subcloned into gp160 expression plasmids with identical cleavage motifs and gp41 sequences. Cells cotransfected with these plasmids and Δ
env
genomes were able to produce competent virus. The resulting pseudoviruses incorporated high levels of Env onto virions that exhibited a range of degrees of virion-associated Env cleavage (15 to 40%). Higher levels of cleavage correlated with increased infectivity and increased resistance to macaque plasma, HIV immunoglobulin, soluble CD4, and human monoclonal antibodies 4E10, 2F5, and b12. Based on these data, we discuss a model whereby changes in gp120 of 89.6P impact Env processing and thereby mediate escape from a range of neutralizing agents.
Suppression of Viremia and Evolution of Human Immunodeficiency Virus Type 1 Drug Resistance in a Macaque Model for Antiretroviral Therapy
Authors: Ambrose Zandrea , Palmer Sarah , Boltz Valerie F. , Kearney Mary , Larsen Kay , Polacino Patricia , Flanary Leon , Oswald Kelli , Piatak Michael , Smedley Jeremy , Shao Wei , Bischofberger Norbert , Maldarelli Frank , Kimata Jason T. , Mellors John W. , Hu Shiu-Lok , Coffin John M. , Lifson Jeffrey D. , KewalRamani Vineet N.
Published: September 2007

Antiretroviral therapy (ART) in human immunodeficiency virus type 1 (HIV-1)-infected patients does not clear the infection and can select for drug resistance over time. Not only is drug-resistant HIV-1 a concern for infected individuals on continual therapy, but it is an emerging problem in resource-limited settings where, in efforts to stem mother-to-child-transmission of HIV-1, transient nonnucleoside reverse transcriptase inhibitor (NNRTI) therapy given during labor can select for NNRTI resistance in both mother and child. Questions of HIV-1 persistence and drug resistance are highly amenable to exploration within animals models, where therapy manipulation is less constrained. We examined a pigtail macaque infection model responsive to anti-HIV-1 therapy to study the development of resistance. Pigtail macaques were infected with a pathogenic simian immunodeficiency virus encoding HIV-1 reverse transcriptase (RT-SHIV) to examine the impact of prior exposure to a NNRTI on subsequent ART comprised of a NNRTI and two nucleoside RT inhibitors. K103N resistance-conferring mutations in RT rapidly accumulated in 2/3 infected animals after NNRTI monotherapy and contributed to virologic failure during ART in 1/3 animals. By contrast, ART effectively suppressed RT-SHIV in 5/6 animals. These data indicate that suboptimal therapy facilitates HIV-1 drug resistance and suggest that this model can be used to investigate persisting viral reservoirs.
Isolation of Avian Paramyxovirus 1 from a Patient with a Lethal Case of Pneumonia
Authors: Goebel Scott J. , Taylor Jill , Barr Bradd C. , Kiehn Timothy E. , Castro-Malaspina Hugo R. , Hedvat Cyrus V. , Rush-Wilson Kim A. , Kelly Cassandra D. , Davis Stephen W. , Samsonoff William A. , Hurst Kelley R. , Behr Melissa J. , Masters Paul S.
Published: September 2007

An unknown virus was isolated from a lung biopsy sample and multiple other samples from a patient who developed a lethal case of pneumonia following a peripheral blood stem cell transplant. A random PCR-based molecular screening method was used to identify the infectious agent as avian paramyxovirus 1 (APMV-1; a group encompassing Newcastle disease virus), which is a highly contagious poultry pathogen that has only rarely been found in human infections. Immunohistochemical analysis confirmed the presence of APMV-1 antigen in sloughed alveolar cells in lung tissue from autopsy. Sequence from the human isolate showed that it was most closely related to virulent pigeon strains of APMV-1. This is the most completely documented case of a systemic human infection caused by APMV-1 and is the first report of an association between this virus and a fatal disease in a human.
DDX3 DEAD-Box RNA Helicase Is Required for Hepatitis C Virus RNA Replication
Authors: Ariumi Yasuo , Kuroki Misao , Abe Ken-ichi , Dansako Hiromichi , Ikeda Masanori , Wakita Takaji , Kato Nobuyuki
Published: September 2007

DDX3, a DEAD-box RNA helicase, binds to the hepatitis C virus (HCV) core protein. However, the role(s) of DDX3 in HCV replication is still not understood. Here we demonstrate that the accumulation of both genome-length HCV RNA (HCV-O, genotype 1b) and its replicon RNA were significantly suppressed in HuH-7-derived cells expressing short hairpin RNA targeted to DDX3 by lentivirus vector transduction. As well, RNA replication of JFH1 (genotype 2a) and release of the core into the culture supernatants were suppressed in DDX3 knockdown cells after inoculation of the cell culture-generated HCVcc. Thus, DDX3 is required for HCV RNA replication.
Virally Delivered Cytokines Alter the Immune Response to Future Lung Infections
Authors: Harker James , Bukreyev Alexander , Collins Peter L. , Wang Belinda , Openshaw Peter J. M. , Tregoning John S.
Published: September 2007

Respiratory syncytial virus (RSV) is an important cause of infant morbidity and mortality worldwide and is increasingly recognized to have a role in the development and exacerbation of chronic lung diseases. There is no effective vaccine, and we reasoned that it might be possible to skew the immune system towards beneficial nonpathogenic responses by selectively priming protective T-cell subsets. We therefore tested recombinant RSV (rRSV) candidates expressing prototypic murine Th1 (gamma interferon [IFN-γ]) or Th2 (interleukin-4 [IL-4]) cytokines, with detailed monitoring of responses to subsequent infections with RSV or (as a control) influenza A virus. Although priming with either recombinant vector reduced viral load during RSV challenge, enhanced weight loss and enhanced pulmonary influx of RSV-specific CD8
+
T cells were observed after challenge in mice primed with rRSV/IFN-γ. By contrast, rRSV/IL-4-primed mice were protected against weight loss during secondary challenge but showed airway eosinophilia. When rRSV/IL-4-primed mice were challenged with influenza virus, weight loss was attenuated but was again accompanied by marked airway eosinophilia. Thus, immunization directed toward enhancement of Th1 responses reduces viral load but is not necessarily protective against disease. Counter to expectation, Th2-biased responses were more beneficial but also influenced the pathological effects of heterologous viral challenge.
IMPROVEMENT OF SIMPLER ALGORITHM FOR INCOMPRESSIBLE FLOW ON STAGGERED GRID SYSTEM
Authors: LEE T. S. , CHENG Y. P. , LOW H. T.
Published: September 2007

In this paper, the updating of the intermediate velocity in the correction stage in SIMPLE-like algorithms on staggered grid is discussed in detail, based on the discussion CLEARER algorithm that is extended from the non-staggered grid to the staggered grid. The performance of SIMPLER and CLEARER algorithms are compared using two numerical examples with reliable solutions. The results show that CLEARER can predict the numerical results as accurately as SIMPLER, and it can also enhance the convergence rate greatly under low under-relaxation factors. In some cases CLEARER algorithm can only need 27% of iteration number required by SIMPLER to reach the same convergence criterion.
MODELING TEMPORAL AND SPATIAL FEATURES OF COLLABORATION NETWORK
Authors: CHANDRA ANJAN KUMAR , HAJRA KAMALIKA BASU , KUMAR DAS PRATAP , SEN PARONGAMA
Published: September 2007

The collaboration network is an example of a social network which has both non-trivial temporal and spatial dependence. Based on the observations of collaborations in Physical Review Letters, a model of collaboration network is proposed which correctly reproduces the time evolution of the link length distributions, clustering coefficients, degree distributions, and assortative property of real data to a large extent.
MASS MODIFIED OUTLET BOUNDARY FOR A FULLY DEVELOPED FLOW IN THE LATTICE BOLTZMANN EQUATION
Authors: TONG C. Q. , HE Y. L. , TANG G. H. , WANG Y. , LIU Y. W.
Published: September 2007

Outlet boundary conditions for fully developed flow are discussed for a two-dimensional lattice Boltzmann BGK model (LBGK), and most of the existing ones are found to be incapable of ensuring mass conservation of the whole flow field. Based on this analysis, a mass modified outlet boundary is proposed, which can completely overcome this shortcoming. Tests were done against a two-dimensional plane channel flow and flow over a backward-facing step. The results show that the present method is of good accuracy, stability, and fast convergence, especially for relatively high relaxation time and relatively small lattice number. It can improve the accuracy of the numerical results as well as save the computational time.
WHY DOES THE STANDARD GARCH(1, 1) MODEL WORK WELL?
Authors: JAFARI G. R. , BAHRAMINASAB A. , NOROUZZADEH P.
Published: September 2007

The AutoRegressive Conditional Heteroskedasticity (ARCH) and its generalized version (GARCH) family of models have grown to encompass a wide range of specifications, each of them is designed to enhance the ability of the model to capture the characteristics of stochastic data, such as financial time series. The existing literature provides little guidance on how to select optimal parameters, which are critical in efficiency of the model, among the infinite range of available parameters. We introduce a new criterion to find suitable parameters in GARCH models by using Markov length, which is the minimum time interval over which the data can be considered as constituting a Markov process. This criterion is applied to various time series and its results support the known idea that GARCH(1, 1) model works well.
CALCULATION OF THE PHOTODECAY WIDTH FOR A METASTABLE MUONIC SYMMETRIC ION WITH AN ADIABATIC REPRESENTATION METHOD
Authors: GHEISARI R.
Published: September 2007

A variational approach using new wave functions to [Formula: see text] and [Formula: see text] muonic symmetric molecular ions is proposed. The present method is based on the calculations of the photodecay widths of muonically excited molecular states and their comparison with recent precise data. The numerical calculations were done with a short computation time. Our results are close to the report.
SCALAR FIELD THEORY IN THE AdS/CFT CORRESPONDENCE: AN OPERATOR FORMULATION
Authors: KERIMOV G. A.
Published: September 2007

Starting with a scalar field theory in Euclidean anti-de Sitter space constructed in an earlier paper, we examine the boundary limit of the quantized bulk field. Our AdS/CFT correspondence is generally valid for interacting fields, and is illustrated by a treatment of three-point function for scalar fields of arbitrary mass.
ESTIMATES FOR PARAMETERS AND CHARACTERISTICS OF THE CONFINING SU(3)-GLUONIC FIELD IN η-MESON FROM TWO-PHOTON DECAY
Authors: GONCHAROV YU. P.
Published: September 2007

On the basis of the confinement mechanism earlier proposed by author, the electric form factor of η-meson is nonperturbatively calculated. The latter is then applied to describe electromagnetic decay η→2γ which entails estimates for parameters of the confining SU(3)-gluonic field in η-meson. The corresponding estimates of the gluon concentrations, electric and magnetic color field strengths are also adduced for the mentioned field.
DUALITY THROUGH THE SYMPLECTIC EMBEDDING FORMALISM
Authors: ABREU E. M. C. , MENDES A. C. R. , NEVES C. , OLIVEIRA W. , TAKAKURA F. I.
Published: September 2007

In this work we show that we can obtain dual equivalent actions following the symplectic formalism with the introduction of extra variables which enlarge the phase space. We show that the results are equal as the one obtained with the recently developed gauging iterative Noether dualization method. We believe that, with the arbitrariness property of the zero mode, the symplectic embedding method is more profound since it can reveal a whole family of dual equivalent actions. We illustrate the method demonstrating that the gauge-invariance of the electromagnetic Maxwell Lagrangian broken by the introduction of an explicit mass term and a topological term can be restored to obtain the dual equivalent and gauge-invariant version of the theory.
MASS-GAPS AND SPIN CHAINS FOR (SUPER)MEMBRANES
Authors: AGARWAL ABHISHEK
Published: September 2007

We present a method for computing the nonperturbative mass-gap in the theory of bosonic membranes in flat background space–times. The analysis is extended to the study of membranes coupled to background fluxes as well. The computation of mass-gaps is carried out using a matrix regularization of the membrane Hamiltonians. The mass gap is shown to be naturally organized as an expansion in a "hidden" parameter, which turns out to be [Formula: see text] being the related to the dimensionality of the background space. We then proceed to develop a large N perturbation theory for the membrane/matrix-model Hamiltonians around the quantum/mass corrected effective potential. The same parameter that controls the perturbation theory for the mass gap is also shown to control the Hamiltonian perturbation theory around the effective potential. The large N perturbation theory is then translated into the language of quantum spin chains and the one-loop spectra of various bosonic matrix models are computed by applying the Bethe ansatz to the one-loop effective Hamiltonians for membranes in flat space–times. The spin chains corresponding to the large N effective Hamiltonians for the relevant matrix models are generically not integrable. However, we are able to find large integrable subsectors for all the spin chains of interest. Moreover, the continuum limits of the spin chains are mapped to integrable Landau–Lifschitz models even if the underlying spin chains are not integrable. Apart from membranes in flat space–times, the recently proposed matrix models (arXiv:hep-th/0607005) for noncritical membranes in plane wave type space–times are also analyzed within the paradigm of quantum spin chains. The bosonic sectors of all the models proposed in arXiv:hep-th/0607005 are diagonalized at the one-loop level and an intriguing connection between the existence of supersymmetric vacua and one-loop integrability is also presented.
FERMIONIC ZERO MODES IN SELF-DUAL VORTEX BACKGROUND ON A SPHERE
Authors: LIU YU-XIAO , ZHAO LI , ZHANG LI-JIE , DUAN YI-SHI
Published: September 2007

We study fermionic zero modes in the self-dual vortex background on an extra two-dimensional Riemann surface in 5+1 dimensions. Using the generalized Abelian Higgs model, we obtain the inner topological structure of the self-dual vortex and establish the exact self-duality equation with topological term. Then we analyze the Dirac operator on an extra sphere and the effective Lagrangian of four-dimensional fermions with the self-dual vortex background. Solving the Dirac equation, the fermionic zero modes on a sphere in two simple cases are obtained.
IRREVERSIBLE SUSCEPTIBILITY OF INITIAL MAGNETIZATION CURVES DEFINED BY ENERGY CONSIDERATION
Authors: GOEV G. , MASHEVA V. , MIKHOV M. , GESHEV J.
Published: September 2007

A method for the estimation of reversible and irreversible susceptibilities of initial magnetization curves has been developed. It deals with the energy necessary for magnetizing and demagnetizing the sample, but neither with the nature of the magnetization processes nor with a specific type of anisotropy, so it could be applied for a wide variety of real materials. A set of minor hysteresis loops of an initially demagnetized sample, plotted with progressively increasing maximum magnetic field, has been used. The obtained results showed excellent agreement with those calculated by the remanence curve method for a Stoner–Wohlfarth model system.
PARTITION FUNCTION OF THE GAS-LIQUID COEXISTENT SYSTEM
Authors: ZHANG SUHONG , LI ZIJING , GUI YUANXING , WANG WEI
Published: September 2007

In this article the equilibrious gas-liquid coexistent system is studied, and a new expression of partition function (PF) corresponding to the two-phase region is derived. Based on this expression, the horizontal line in the isotherm of pressure versus volume is obtained naturally for a finite particle system (i.e., without the necessity of taking the thermodynamic limit). Extending this PF, we can gain a unitive form of the one-component fluid in any system (i.e., one-phase or multi-phase). Then the whole isotherm will have reasonable statistical foundation. The VDW fluid system is discussed as a concrete example.
SIMULTANEOUS EFFECT OF MECHANICAL TENSION ON ELECTRICAL LIFETIME OF SOME INORGANIC COMPOSITES
Authors: ÖZCANLI Y. LENGER , BOYDAǦ F. Ş. , ALEKBEROV V. A. , HIKMET I. , CANTÜRK M.
Published: September 2007

In this work, the simultaneous effect of mechanical tension (σ) and electrical strength (E) on electrical lifetime (τE) for pure low density polyethylene (LDPE)/polypropylene (PP) and composites with different commercial diamond-additive/glass fiber additive percentages is experimentally studied. The role of this effect on degradation mechanisms is investigated. log τE,σ-f(E) and Eσ-f(σ) graphs are drawn, new equations are proposed and determined parameters at constant temperature for pure LDPE and PP, and for optimum composites (LDPE/0.5% diamond, PP/0.5% glass fiber) are listed. The results indicate that the degradation speed decreases more for composites than for pure LDPE and PP. The electrical durability for composites after the simultaneous effect of σ decreases 18–20%, while for pure LDPE and PP, it decreases 50–55%.
EFFECT OF PHOSPHORUS ADDITION ON PHYSICAL AND ELECTRICAL PROPERTIES OF TANTALUM POWDER
Authors: PURUSHOTHAM Y. , GOVINDAIAH R. , KUMAR ARBIND , PRAKASH T. L.
Published: September 2007

The present work is aimed at studying the effect of phosphorus addition on physical and electrical properties of tantalum powder. Tantalum anodes were compacted from tantalum powder, which were doped with different concentrations of phosphorus in the form of phosphoric acid. Anodes were sintered at 1550°C for 30 min. Properties such as density, microstructure, CV (capacitance times voltage constant) and DC leakage were studied. Significant improvement in electrical properties was observed, results of which are presented here.
GROWTH OF GdBa2Cu3Oy FILMS PREPARED BY BaF2 PROCESS WITHOUT WATER VAPOR
Authors: KITA R. , NAKAMURA T. , ICHINOSE A. , MIURA O. , MATSUMOTO K. , YOSHIDA Y. , MUKAIDA M. , HORII S.
Published: September 2007

We have investigated the influences of the heating rate and film thickness on the growth of GdBa 2 Cu 3 O y (GBCO) thin films prepared by the BaF 2ex-situ process without water vapor. Critical current density (J c ) and surface morphology of the GBCO films were improved by increasing the heating rate during growth from 30 to 50°C/min. The GBCO films prepared by the heating rate of 50°C/min had the maximum J c of 2.1 MA/cm2. The J c value of the GBCO films was about 2 MA/cm2 up to 200 nm, and decreased to 0.92 MA/cm2 at 400 nm.
A PILOT STUDY OF PRODUCTIVE VERSUS NONPRODUCTIVE KNOWLEDGE ACQUISITION IN EMBEDDED SOFTWARE DEVELOPMENT
Authors: WINBERG SIMON L. , SCHACH STEPHEN R.
Published: September 2007

Embedded software development involves many knowledge acquisition (KA) tasks that collectively account for a significant proportion of development costs. This paper presents a pilot study that used case studies to investigate the extent to which knowledge acquired in learning tasks was used in developing a final product. Data obtained from the case studies were used to construct event chains, which trace the amount of time spent on KA tasks and the types of knowledge acquired in individual learning tasks. Knowledge acquired was separated into three categories: knowledge of data, knowledge of process, and knowledge of innovation. Each top-level category was further partitioned into productive and nonproductive knowledge depending on whether the knowledge was, or was not used, in the construction of the final product. The event chains were processed to visualize the chronological progression of how knowledge acquired in the separate categories moved between subcategories of productive and nonproductive knowledge as development progressed. Results of this analysis show trends in KA for the case studies investigated, which we plan to use in the design of future work on this topic.
NUMERICAL STABILITY OF THE FINITE ELEMENT IMMERSED BOUNDARY METHOD
Authors: BOFFI DANIELE , GASTALDI LUCIA , HELTAI LUCA
Published: September 2007

The immersed boundary method is both a mathematical formulation and a numerical method. In its continuous version it is a fully nonlinearly coupled formulation for the study of fluid structure interactions.

Many numerical methods have been introduced to reduce the difficulties related to the nonlinear coupling between the structure and the fluid evolution. However numerical instabilities arise when explicit or semi-implicit methods are considered. In this work we present a stability analysis based on energy estimates of the variational formulation of the immersed boundary method.

A two-dimensional incompressible fluid and a boundary in the form of a simple closed curve are considered. We use a linearization of the Navier–Stokes equations and a linear elasticity model to prove the unconditional stability of the fully implicit discretization, achieved with the use of a backward Euler method for both the fluid and the structure evolution, and a CFL condition for the semi-implicit method where the fluid terms are treated implicitly while the structure is treated explicitly.

We present some numerical tests that show good accordance between the observed stability behavior and the one predicted by our results.
OPTIMIZATION OF TRAFFIC ON ROAD NETWORKS
Authors: ANNUNZIATA CASCONE , D'APICE CIRO , BENEDETTO PICCOLI , LUIGI RARITÀ
Published: September 2007

This paper focuses on the optimization of traffic flow on a road network, modeled by a fluid-dynamic approach. Three cost functionals that measure average velocity, average traveling time, and total flux of cars, are considered. First, such functionals are optimized for two simple networks that consist of a single junction: one with two incoming and one outgoing roads (junctions of 2 × 1 type), and the other with one incoming and two outgoing roads (junctions of 1 × 2 type). The optimization is made with respect to right of way parameters and traffic distribution coefficients, obtaining an explicit solution. Then, through simulations, the traffic behavior for complex networks is studied. The main result is that the local optimization ensures a very good result also for the complete network. This is shown by the case study of Re di Roma Square, a big traffic circle of the urban network of Rome.
NUMERICAL SOLUTION OF NONLINEAR ELASTICITY PROBLEMS WITH LAVRENTIEV PHENOMENON
Authors: BAI YU , LI ZHIPING
Published: September 2007

A convergence theory is established for a truncation method in solving polyconvex elasticity problems involving the Lavrentiev phenomenon. Numerical results on a recent example by Foss et al., which has a polyconvex integrand and admits continuous singular minimizers, not only verify our convergence theorems but also provide a sharper estimate on the upper bound of a perturbation parameter for the existence of the Lavrentiev phenomenon in the example.
Environmental Research at Monash University in Malaysia
Authors: Yule Catherine M.
Published: September 2007

This article exhibits the research into environmental issues in Malaysia.
DDBJ — Website to Deposit, Retrieve and Analyze Sequences and Annotations of Genes and Genomes
Authors: Sugawara Hideaki
Published: September 2007

This article gives the short out look about DDBJ website on Deposit, Retrieve and analyze sequences of genes and genomes.
Integrating A- and B-Share Markets in China: The Effects of Regulatory Policy Changes on Market Efficiency
Authors: Lu Changjiang , Wang Kemin , Chen Haiwei , Chong James
Published: September 2007

We investigate the effectiveness of two recent regulatory policy changes on market efficiency in the Chinese A- and B-share markets. Overall, the opening of the B-share market to domestic Chinese investors and the limited opening of the A-share market to foreign investors increase market efficiency. The opening of the B-share market significantly reduces the price differential between A- and B-shares. Furthermore, there is no longer feedback in returns between the two markets in recent years. Our results provide evidence that there is no detrimental effect to market efficiency by integrating Chinese investors to international markets and foreign investors to the Chinese stock markets.
AN ANALYTICAL STUDY ON THE LATERAL-TORSIONAL BUCKLING OF LINEARLY TAPERED CANTILEVER STRIP BEAMS
Authors: CHALLAMEL NOËL , ANDRADE ANÍSIO , CAMOTIM DINAR
Published: September 2007

In this paper, the elastic lateral-torsional buckling of tapered cantilever strip beams acted by a tip load is investigated. Analytical solutions of the buckling problem are derived for cantilevers with a linearly varying depth. It is shown that the corresponding governing differential equation is a particular case of the general confluent equation, whose solution is given in terms of confluent hypergeometric functions. The buckling load corresponds to the lowest positive root of a 4×4 characteristic determinant arising from the introduction of the general solution of the differential equation into the boundary conditions. Finally, one discusses the optimization of the cantilever geometrical shape (for constant volume), as far as its resistance to lateral-torsional buckling is concerned.
A HIGH-RESOLUTION SPACE–TIME CONSERVATIVE METHOD FOR NON-LINEAR HYPERBOLIC CONSERVATION LAWS
Authors: QURRAT-UL-AIN  , QAMAR SHAMSUL , WARNECKE GERALD
Published: September 2007

We present a second-order scheme for the numerical solution of hyperbolic systems which treats space and time in a unified manner. The flow variables and their slopes are the basic unknowns in the scheme. The scheme utilizes the advantages of the space–time conservation element and solution element (CE/SE) method of Chang [1995] as well as central schemes of Nessyahu and Tadmor [1990]. However, unlike the CE/SE method the present scheme is Jacobian-free and hence like the central schemes can also be applied to any hyperbolic system. In Chang's method, a finite difference approach is being used for the slope calculation in case of non-linear hyperbolic equations. We propose to propagate the slopes by a scheme even in the case of non-linear systems. By introducing a suitable limiter for the slopes of flow variables, we can apply the same scheme to linear and non-linear problems with discontinuities. The scheme is simple, efficient and has a good resolution especially at contact discontinuities. We derive the scheme for one- and two-space dimensions. In two-space dimensions we use structured triangular meshes. The second-order accuracy of the scheme has been verified by numerical experiments. Several numerical tests presented in this article validate the accuracy and robustness of the present scheme.
SOLVABILITY OF A QUASI-STEADY ROLLING PROBLEM WITH SLIGHTLY COMPRESSIBLE MATERIAL MODEL
Authors: ANGELOV T. A.
Published: September 2007

A quasi-steady rolling problem with slightly compressible, rigid-viscoplastic and isotropic hardening material model and nonlinear Coulomb friction law are studied. The problem is stated in the form of a nonlinear variational inequality coupled with an equivalent strain evolution equation. Under restrictions on the material characteristics, existence and uniqueness results are obtained and the convergence of a successive linearization method of solution is proved. An algorithm, combining this method with the finite element method, is proposed and applied to solve numerically an example problem.
THE ISSUES OF SOLUTION APPROXIMATION IN HIGHER-ORDER SCHEMES ON DISTORTED GRIDS
Authors: PETROVSKAYA N. B. , WOLKOV A. V.
Published: September 2007

The impact of grid cell geometry on the accuracy of a high order discretization is studied. The issues of solution approximation are investigated on unstructured grids where grid cells are present that are almost degenerate. It will be demonstrated that high-order discretization schemes which employ compact discretization stencil are less sensitive to the geometry of a distorted grid in comparison with those over expanded stencils.
INTRA-ORGANISATIONAL KNOWLEDGE DRIVERS IN THE INPD PROCESS: THE CASE OF WATTYL LIMITED
Authors: RIEGE ANDREAS , O'KEEFFE MATTHEW
Published: September 2007

While several frameworks have attempted to incorporate knowledge management within the principles of innovation, there is still scant evidence of the influence of key drivers that facilitate intra-organisational knowledge transfers to improve international new product development (INPD) processes. We draw on three related literature streams focusing on parts of the organisation, innovation and knowledge management literature and present a conceptualisation of drivers that tend to influence knowledge flows between R&D centres in three international locations. Our results are based on R&D and product managers' experiences and perceptions at Wattyl Limited, a multinational Australian manufacturer of paint and coating products. The findings demonstrate that a value-creating innovation depends on a number of internal knowledge drivers that facilitate the INPD process. They also add to further clarifying some conceptual issues in the extant literature. We also draw attention to specific messages for R&D and product managers involved in INPD processes.
ANALYSING EXPORT INTENSITY OF THE SELECT ELECTRONICS FIRMS IN INDIA
Authors: JAUHARI VINNIE
Published: September 2007

The second half of the 1990s has witnessed almost three-fold increase in the exports of Indian electronics industry. The study proposes a model for analysing the export intensity of 164 electronics firms in India and tests the same empirically. The Tobit model is estimated using firm level panel data for the period 2000–2005 for the electronics industry in India. The results show that both size of the firm, foreign direct investment and capital employed have played an important role in boosting exports in this sector. The study has policy implications to improve the performance of the Indian Electronics sector in India and similar other countries.
UNINHIBITED POINCARÉ SERIES
Authors: DE AZEVEDO PRIBITKIN WLADIMIR
Published: September 2007

We introduce a class of functions that generalize the epoch-making series of Poincaré and Petersson. Our "uninhibited Poincaré series" permits both a complex weight and an arbitrary multiplier system that is independent of the weight. In this initial paper we provide their Fourier expansions, as well as their modular behavior. We show that they are modular integrals that possess interesting periods. Moreover, we establish with relative ease that they "almost never" vanish identically. Along the way we present a seemingly unknown historical truth concerning Kloosterman sums, and also an alternative approach to Petersson's factor systems. The latter depends upon a simple multiplication rule.
THE FIRST NEGATIVE HECKE EIGENVALUE
Authors: IWANIEC H. , KOHNEN W. , SENGUPTA J.
Published: September 2007

We shall improve earlier estimates on the first sign change of the Hecke eigenvalues of a normalized cuspidal newform of level N.
An interpretation of the Variscan tectonics of SW Britain
Authors: Coward M. P. , Smallwood S.
Published: September 2007

The structure of SW Britain is interpreted in terms of thin-skinned tectonics, producing a NNW verging fold and thrust zone. In south Wales the thrusts involve high level imbricate stacks showing some 20–40% shortening with a shallow floor thrust in Namurian-Westphalian strata, cut to the south by deeper level folds and thrusts with a basal decoupling zone in or below the Lower Palaeozoic rocks. In Devon and Cornwall the Upper Palaeozoic rocks show a gently dipping, widespread and locally intense cleavage related to the progressive development of large thrust sheets and associated inclined to recumbent folds. In north Cornwall these northward verging structures have been redeformed and often completely overprinted by a large south verging backthrust. Some of this backthrust movement may be offset, by a lateral ramp, to a much lower decoupling zone, producing a major backfold in south Devon.

The thrust transport direction is to the NNW as determined from mineral lineations, maximum extension directions, fold and thrust traces and tear faults. Fold hinges are generally normal to the transport direction but are locally rotated into the NNW trend in more intensely deformed zones. In north Devon and south Wales, the folds are oblique suggesting a component of differential movement. Considering SW Britain and southern Ireland the fold trends are arcuate and there is often extension parallel to the fold axes. These phenomena are interpreted as due to the obliquity of the thrusting and the Variscan front. Pre-tectonic facies changes along the front hinder lateral fault propagation giving sticking points at lateral tips which become poles of rotation.

Deformation affected only the upper crust; there was no major crustal thickening during Variscan tectonics though the crust has been locally thinned probably by a factor of 2 before onset of compression in Devonian times. Deformation was diachronous with a slow displacement rate. Sedimentation occurred in an advancing series of fore-deeps ahead of the deformed and thickened zone. Estimates of shortening across the thin-skinned zone are about 50%, that is 150 km across SW England. The crust beneath the thin skin must extend back beneath the English Channel and northern France.
Interpretations of seismic and gravity surveys over the eastern part of the Cornubian platform
Authors: Edwards J. W. F.
Published: September 2007

Gravity interpretations suggest that the Cornubian granite batholith continues WSW from Land’s End as far as 8°W, and that the Haig Fras granite is part of a separate, parallel batholith. South-east of the Cornubian batholith there is a zone where seismic sections show dipping reflectors which may be thrusts. The axis of the Cornubian batholith is displaced dextrally between the Scilly Isles and Land’s End. There are dextral displacements of the axes of the Cornubian batholith and of the Haig Fras batholith at about 7°W, and on the line of these two displacements is an intrusion of high density. A deep horizontal reflector underlies the Cornubian batholith near the Scilly Isles.
The Ribblesdale fold belt, NW England—a Dinantian-early Namurian dextral shear zone
Authors: Arthurton Russell S.
Published: September 2007

Folds and faults in various
en échelon
patterns affect the Tournaisian-early Namurian sedimentary rocks of the Craven basin, a rift basin which includes Dinantian and possibly late Devonian strata some 5 km thick. The structures are interpreted as a response to regional dextral shear, which accompanied sedimentation from mid-Dinantian to early Namurian times at least. The principal Ribblesdale folds are viewed as products, in the Carboniferous cover, of primary wrenching on inherited fractures in the Lower Palaeozoic basement. Some
en échelon
sets of minor folds are regarded as products of secondary wrenching in the axial zones of ‘primary’ folds. The block-basin transition zone south of the North Craven fault appears to have been affected by dextral transtension during the late Brigantian (late Dinantian).
The Alleghenian orogeny in eastern North America
Authors: Rast N.
Published: September 2007

The Alleghenian-Variscan-Hercynian orogeny in eastern North America has five structural domains: (1) Newfoundland-Maritime (northern) platform; (2) northern Appalachian Maritime-New England Variscan belt; (3) Alleghenian platform; (4) central-southern Appalachian (Alleghenian) orogen; (5) Ouachita belt. Connections between these domains are generally faulted or unexposed and the domains are heterogeneous.

There is a major discontinuity between the northern Appalachians and central-southern Appalachians. In the northern Appalachians the Variscan orogeny is distinct from the Acadian, but not so in the central-southern Appalachians. The Alleghenian overthrusting of the southern Appalachians is still to be traced to the north where the whole of southern Nova Scotia may be totally allochthonous.

Also, the northern but not the southern belt appears to have suffered in Devonian to Carboniferous times a sinistral strike-slip movement of about 2000 km. By taking this movement into account it is suggested that the four Appalachian domains have been assembled in Devonian-Lower Carboniferous time by transcurrent faulting and deformed in the late Carboniferous-Permian times by subduction-related processes.

The geology of the Ouachita belt is different from the southern Appalachians and their unexposed connection is still enigmatic. The timing of orogenic events in the two domains also differs.

It is possible that the Ouachitas were deformed by collision with the South American plate, while the Appalachians were deformed by collision with the African plate.
The deformation and metamorphism of Carboniferous rocks in Maritime Canada and New England
Authors: Mosher Sharon , Rast Nicholas
Published: September 2007

In the northern Appalachians, rocks showing polyphase Variscan/Alleghenian deformation are found in Nova Scotia, New Brunswick, Rhode Island and Massachusetts. In Canada the deformed succession ranges from Tournaisian to Permian, and in New England from Westphalian to Stephanian.

The same polyphase deformation sequence (F
1
–F
4
) involving the same sequential changes in the geometry and vergence of structures can be recognized in New Brunswick and in Rhode Island. This implies that the Carboniferous rocks in both areas were affected by a similar set of stresses in late Carboniferous-Permian times.

The folded succession in both areas is affected by the essentially post-deformational regional metamorphism which reaches garnet grade in New Brunswick and sillimanite grade in Rhode Island. Granites, probably of anatectic origin, cut through the metamorphic rocks in both areas, but are more prevalent in Rhode Island.

In both areas overthrusting can be related to fold episodes, and late transcurrent and normal faults of a brittle-ductile nature cut earlier structures. Although there are several current plate tectonic interpretations of Variscan events in the northern Appalachians, all are speculative and further data are needed.
A clockwise rotation of Variscan strain orientation in SE New England and regional implications
Authors: Wintsch R. P. , Lefort J.-P.
Published: September 2007

A temperature-time-strain path is described for the Honey Hill fault system in eastern Connecticut, U.S.A. The path is based on
40
Ar-
39
Ar mineral age data, on metamorphic petrology and on the orientation of mineral lineations and other small-scale structures in ductile fault zones. Collectively, the data show that the thrusting direction rotated from ESE at 290 Ma to due south at 250 Ma. These results coincide in the sense of rotation and in the orientation of movement with predictions emerging from hypotheses concerning the collision of Gondwanaland with Laurussia. If southern New England can be shown not to have rotated during this collision, then the data from eastern Connecticut would suggest that the WNW approach of Gondwanaland toward Laurussia turned north only in mid-Permian times.