bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacokinetics and Buccal Mucosal Concentrations of a 15 Milligram per Kilogram of Body Weight Total Dose of Liposomal Amphotericin B Administered as a Single Dose (15 mg/kg), Weekly Dose (7.5 mg/kg), or Daily Dose (1 mg/kg) in Peripheral Stem Cell Transplant Patients
Authors: Gubbins Paul O. , Amsden Jarrett R. , McConnell Scott A. , Anaissie Elias J.
Published: June 2009

The pharmacokinetics and safety of extended-interval dosing of prophylactic liposomal amphotericin B (L-AMB) in peripheral stem cell transplant recipients were evaluated. The patients received L-AMB daily at 1 mg/kg of body weight or weekly at 7.5 mg/kg or received L-AMB as a single dose (15 mg/kg). The buccal mucosal tissue concentrations of L-AMB were measured. Of the 24 patients enrolled, 5 withdrew after the initial dose due to an infusion-related reaction (
n
= 2) or significant increases in the serum creatinine (Scr) levels (
n
= 3). Weekly L-AMB dosing (7.5 mg/kg) produced mean plasma concentrations of >0.300 μg/ml for the first 7 days and >0.220 μg/ml for 7 days after the second dose. A single L-AMB dose (15 mg/kg) produced mean plasma concentrations of >0.491 μg/ml for at least 7 seven days. These concentrations are within the range of the MICs reported in the literature for susceptible strains of
Candida
and are at the lower limits of the MICs for
Aspergillus
spp. Extended-interval dosing produced buccal mucosal tissue concentrations well in excess of the MICs reported in the literature for susceptible strains of
Candida
and
Aspergillus
spp. Infusion-related reactions occurred in 24% of the patients. Baseline and end-of-study Scr, electrolyte (K
+
, Mg
2+
, PO
4
), and serum transaminase levels were similar across the dosage groups. Five (31%) patients met the nephrotoxicity definition prior to completion of the study. Patients in the weekly or single-dose groups experienced nephrotoxicity significantly faster than the patients in the daily dosing cohort. A weekly L-AMB dose (7.5 mg/kg) or a single L-AMB dose (15 mg/kg) produced sufficient concentrations in plasma and highly vascular tissue to warrant further studies of the safety, efficacy, and practicality of the weekly prophylactic administration of L-AMB.
Influence of Recombination on Development of Mutational Resistance to Linezolid in
Enterococcus faecalis
JH2-2
Authors: Boumghar-Bourtchaï Leyla , Dhalluin Anne , Malbruny Brigitte , Galopin Sébastien , Leclercq Roland
Published: June 2009

We compared the propensities of
Enterococcus faecalis
JH2-2 and of the recombination-deficient JH2-2
recA
strain to develop mutational resistance to linezolid. In both organisms, a mutation in a single
rrl
copy conferred resistance to linezolid. Delay in acquisition of the mutation by other
rrl
copies in JH2-2
recA
showed that gene conversion contributed to the acquisition of resistance.
Functional and Immunological Characterization of a Duffy Binding-Like Alpha Domain from
Plasmodium falciparum
Erythrocyte Membrane Protein 1 That Mediates Rosetting
Authors: Mayor Alfredo , Rovira-Vallbona Eduard , Srivastava Anand , Sharma Surya K. , Pati Sudhanshu S. , Puyol Laura , Quinto Llorenç , Bassat Quique , Machevo Sonia , Mandomando Inacio , Chauhan Virander S. , Alonso Pedro L. , Chitnis Chetan E.
Published: June 2009

The Duffy binding-like (DBL) domains are common adhesion modules present in
Plasmodium falciparum
erythrocyte membrane protein 1 (PfEMP1) variants, which are responsible for immune evasion and cytoadherence. Knowledge about how immune responses are acquired against polymorphic DBL domains of PfEMP1 can aid in the development of vaccines for malaria. A recombinant DBLα domain, encoded by R29
var1
, which binds complement receptor 1 to mediate rosetting by the
P. falciparum
laboratory strain R29, was expressed in
Escherichia coli
, renatured by oxidative refolding to its native form, and purified to homogeneity. Antibody levels in 704 plasmas obtained from residents of areas of different levels of malaria endemicity in Orissa (India) and Manhiça (Mozambique) were assessed by enzyme-linked immunosorbent assay. The refolded DBLα domain was pure, homogeneous, and functional in that it bound human erythrocytes with specificity and was capable of inhibiting rosetting. The proportion of individuals who had measurable anti-DBLα immunoglobulin G responses was low in areas of low malaria endemicity in Orissa (6.7%) but high in areas of high endemicity in Orissa (87.5%) and Manhiça (74.5%). Seroprevalence and antibody levels against the recombinant protein increased with the age of inhabitants from areas with high transmission rates (
P
< 0.001). Half of the children in these areas had seroconverted by the age of 5 years. These findings suggest that in spite of the extreme polymorphism of PfEMP1 DBLα domains, the acquisition of specific antibodies is rapid and age related and reflects the reduced risk of malaria in areas with high transmission rates. Further studies are required to elucidate the role of these antibodies in protection from malaria.
Real-Time Observation ofListeria monocytogenes-Phagocyte Interactions in Living Zebrafish Larvae
Authors: Levraud Jean-Pierre , Disson Olivier , Kissa Karima , Bonne Isabelle , Cossart Pascale , Herbomel Philippe , Lecuit Marc
Published: June 2009

The zebrafish,Danio rerio, has become a popular vertebrate model for the study of infections, mainly because of its excellent optical accessibility at the embryonic and larval stages, when the innate immune system is already effective. We have thus tested the susceptibility of zebrafish larvae to the human pathogenListeria monocytogenes, a gram-positive, facultative, intracellular bacterium that is known to survive and multiply in professional phagocytes and that causes fatal meningitis and abortions. Intravenous injection of early zebrafish larvae resulted in a progressive and ultimately fatal infection. Blood-borneL. monocytogenesbacteria were quickly trapped and engulfed by macrophages, an event that, for the first time, could be captured in vivo and in real time. Granulocytes also participated in the innate immune response. As in mammals, bacteria could escape the macrophage phagosome in a listeriolysin-dependent manner and accessed the cytosol; this event was critical for bacterial virulence, as listeriolysin-deficient bacteria were completely avirulent. Actin comet tails and protrusions were observed, suggesting cell-to-cell spread; these phenomena also played a role in virulence in zebrafish larvae, asactA-deficient bacteria were attenuated. These results demonstrate the relevance of the genetically tractable and optically accessible zebrafish model for the study ofL. monocytogenespathogenesis and particularly for the dissection of its interactions with phagocytes in vivo, a key factor ofL. monocytogenesvirulence.
Neisseria gonorrhoeae
Infection Protects Human Endocervical Epithelial Cells from Apoptosis via Expression of Host Antiapoptotic Proteins
Authors: Follows S. A. , Murlidharan J. , Massari P. , Wetzler L. M. , Genco C. A.
Published: June 2009

Several microbial pathogens can modulate the host apoptotic response to infection, which may contribute to immune evasion. Various studies have reported that infection with the sexually transmitted disease pathogen
Neisseria gonorrhoeae
can either inhibit or induce apoptosis.
N. gonorrhoeae
infection initiates at the mucosal epithelium, and in women, cells from the ectocervix and endocervix are among the first host cells encountered by this pathogen. In this study, we defined the antiapoptotic effect of
N. gonorrhoeae
infection in human endocervical epithelial cells (End/E6E7 cells). We first established that
N. gonorrhoeae
strain FA1090B failed to induce cell death in End/E6E7 cells. Subsequently, we demonstrated that stimulation with
N. gonorrhoeae
protected these cells from staurosporine (STS)-induced apoptosis. Importantly, only End/E6E7 cells incubated with live bacteria and in direct association with
N. gonorrhoeae
were protected from STS-induced apoptosis, while heat-killed and antibiotic-killed bacteria failed to induce protection. Stimulation of End/E6E7 cells with live
N. gonorrhoeae
induced NF-κB activation and resulted in increased gene expression of the NF-κB-regulated antiapoptotic genes
bfl-1
,
cIAP-2
, and
c-FLIP
. Furthermore, cIAP-2 protein levels also increased in End/E6E7 cells incubated with gonococci. Collectively, our results indicate that the antiapoptotic effect of
N. gonorrhoeae
in human endocervical epithelial cells results from live infection via expression of host antiapoptotic proteins. Securing an intracellular niche through the inhibition of apoptosis may be an important mechanism utilized by
N. gonorrhoeae
for microbial survival and immune evasion in cervical epithelial cells.
Oligoclonal CD4+T Cells Promote Host Memory Immune Responses to Zwitterionic Polysaccharide ofStreptococcus pneumoniae
Authors: Groneck Laura , Schrama David , Fabri Mario , Stephen Tom Li , Harms Fabian , Meemboor Sonja , Hafke Helena , Bessler Martina , Becker Jürgen C. , Kalka-Moll Wiltrud M.
Published: June 2009

Zwitterionic polysaccharides of the normal flora bacteria represent a novel class of antigens in that they correct systemic CD4+T-cell deficiencies and direct lymphoid organogenesis during colonization of the host. Presentation of these polysaccharides to CD4+T cells depends on major histocompatibility complex class II- and DM-dependent retrograde transport from lysosomes to the cell surface. Yet the phenotype and clonality of the immune response to the polysaccharide in the mature host immune system have not been studied. Using the zwitterionic capsular polysaccharide Sp1 ofStreptococcus pneumoniae, a transient member of the bacterial flora, in an experimental mouse model of cellular immunity, we demonstrated the accumulation of TH1- and TH17-polarized CD4+CD44highCD62lowCD25−memory T cells. Subcutaneous immunization with Sp1 resulted in an increase of serum immunoglobulin G (IgG), predominantly of the IgG1 subclass, and suggested the presence of a humoral memory response to the polysaccharide. CD4+T cells stimulated with polysaccharide in vitro and in vivo showed a nonrestricted pattern for the T-cell receptor (TCR) β-chain variable region, as demonstrated by semiquantitative reverse transcription-PCR and flow cytometry. Clonotype mapping of in vivo and in vitro polysaccharide-activated CD4+T cells revealed clonotypic TCR transcripts. Taken together, the data show the induction of clonal expansion of CD4+T cells by polysaccharides of commensal bacteria. Cellular and humoral memory host responses imply the ability of these polysaccharides to mediate the expansion of T cells via recognition within the CDR3 region of the TCR.
Preparation and structure of some sulfanylpropenylidene derivatives of Meldrum’s acid
Authors: Crawford Lynne A. , McNab Hamish
Published: June 2009

Condensation of Meldrum’s acid with the 3-sulfanylpropenal derivatives 7a and 7b gives the 3-sulfanylpropenylidene derivatives 2a and 2b, respectively. NMR and X-ray analysis of 2a and 2b show that the electron-donating group conjugates with the electron-withdrawing dioxanedione moiety but the effect is much less pronounced than in analogous dialkylamino derivatives 1. There is little or no conjugation of the ortho-alkylsulfanyl group to the dioxanedione moiety in the benzylidene derivatives 4a and 4b.
Prolotherapy injections and eccentric loading exercises for painful Achilles tendinosis: a randomised trial
Authors: Yelland Michael J , Sweeting Kent R , Lyftogt John A , Ng Shu Kay , Scuffham Paul A , Evans Kerrie A
Published: June 2009

Objective

To compare the effectiveness and cost-effectiveness of eccentric loading exercises (ELE) with prolotherapy injections used singly and in combination for painful Achilles tendinosis.

Design

A single-blinded randomised clinical trial. The primary outcome measure was the VISA-A questionnaire with a minimum clinically important change (MCIC) of 20 points.

Setting

Five Australian primary care centres.

Participants

43 patients with painful mid-portion Achilles tendinosis commenced and 40 completed treatment protocols.

Interventions

Participants were randomised to a 12-week program of ELE (n=15), or prolotherapy injections of hypertonic glucose with lignocaine alongside the affected tendon (n=14) or combined treatment (n=14).

Main outcome measurements

VISA-A, pain, stiffness and limitation of activity scores; treatment costs.

Results

At 12 months, proportions achieving the MCIC for VISA-A were 73% for ELE, 79% for prolotherapy and 86% for combined treatment. Mean (95% CI) increases in VISA-A scores at 12 months were 23.7 (15.6 to 31.9) for ELE, 27.5 (12.8 to 42.2) for prolotherapy and 41.1 (29.3 to 52.9) for combined treatment. At 6 weeks and 12 months, these increases were significantly less for ELE than for combined treatment. Compared with ELE, reductions in stiffness and limitation of activity occurred earlier with prolotherapy and reductions in pain, stiffness and limitation of activity occurred earlier with combined treatment. Combined treatment had the lowest incremental cost per additional responder ($A1539) compared with ELE.

Conclusions

For Achilles tendinosis, prolotherapy and particularly ELE combined with prolotherapy give more rapid improvements in symptoms than ELE alone but long-term VISA-A scores are similar.

Trial registration number

ACTRN: 12606000179538
Detection of testosterone administration based on the carbon isotope ratio profiling of endogenous steroids: international reference populations of professional soccer players
Authors: Strahm E , Emery C , Saugy M , Dvorak J , Saudan C
Published: June 2009

Background and objectives:

The determination of the carbon isotope ratio in androgen metabolites has been previously shown to be a reliable, direct method to detect testosterone misuse in the context of antidoping testing. Here, the variability in the13C/12C ratios in urinary steroids in a widely heterogeneous cohort of professional soccer players residing in different countries (Argentina, Italy, Japan, South Africa, Switzerland and Uganda) is examined.

Methods:

Carbon isotope ratios of selected androgens in urine specimens were determined using gas chromatography/combustion/isotope ratio mass spectrometry (GC-C-IRMS).

Results:

Urinary steroids in Italian and Swiss populations were found to be enriched in13C relative to other groups, reflecting higher consumption of C3 plants in these two countries. Importantly, detection criteria based on the difference in the carbon isotope ratio of androsterone and pregnanediol for each population were found to be well below the established threshold value for positive cases.

Conclusions:

The results obtained with the tested diet groups highlight the importance of adapting the criteria if one wishes to increase the sensitivity of exogenous testosterone detection. In addition, confirmatory tests might be rendered more efficient by combining isotope ratio mass spectrometry with refined interpretation criteria for positivity and subject-based profiling of steroids.
Non-steroidal anti-inflammatory drugs in sports medicine: guidelines for practical but sensible use: Table 1
Authors: Paoloni J A , Milne C , Orchard J , Hamilton B
Published: June 2009

Introduction:

Non-steroidal anti-inflammatory drugs (NSAID) are commonly used in sports medicine. NSAID have known anti-inflammatory, analgesic, antipyretic and antithrombotic effects, although their in-vivo effects in treating musculoskeletal injuries in humans remain largely unknown. NSAID analgesic action is not significantly greater than paracetamol for musculoskeletal injury but they have a higher risk profile, with side-effects including asthma exacerbation, gastrointestinal and renal side-effects, hypertension and other cardiovascular diseases.

Discussion:

The authors recommend an approach to NSAID use in sports medicine whereby simple analgesia is preferentially used when analgesia is the primary desired outcome. However, based both on the current pathophysiological understanding of most injury presentations and the frequency that inflammation may actually be a component of the injury complex, it is premature to suppose that NSAID are not useful to the physician managing sports injuries. The prescribing of NSAID should be cautious and both situation and pathology specific. Both dose and duration minimisation should be prioritised and combined with simple principles of protection, rest, ice, compression, elevation (PRICE), which should allow NSAID-sparing. NSAID use should always be coupled with appropriate physical rehabilitation.

Conclusion:

NSAID are probably most useful for treating nerve and soft-tissue impingements, inflammatory arthropathies and tenosynovitis. They are not generally indicated for isolated chronic tendinopathy, or for fractures. The use of NSAID in treating muscle injury is controversial. Conditions in which NSAID use requires more careful assessment include ligament injury, joint injury, osteoarthritis, haematoma and postoperatively.
Validation of the VISA-A questionnaire for Turkish language: the VISA-A-Tr study: Table 1
Authors: Dogramaci Yunus , Kalaci Aydiner , Kücükkübaş Nigar , Inandı Taceddin , Esen Erdinc , Yanat A Nedim
Published: June 2009

Objectives

To evaluate the validity and reliability of the Turkish version of the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire for patients with Achilles tendinopathy.

Design

Fifty-five patients with a diagnosis of Achilles tendinopathy and 55 healthy subjects were included in the study. VISA-A questionnaires were translated and culturally adapted into Turkish. The final Turkish version (VISA-A-Tr) was tested for reliability on healthy individuals and patients. Tests for internal consistency, validity and structure were performed on 55 patients.

Results

The VISA-A-Tr showed good test–retest reliability (Pearson's r=0.99, p<0.001). The patients with Achilles tendinopathy had a significantly lower score (p<0.001) than the healthy individuals. The VISA-A-Tr score correlated significantly with the Stanish tendon grading system (Spearman's r=−0.86; p<0.001).

Conclusion

The VISA-A-Tr is a valid and reliable tool for evaluating the severity of Achilles tendinopathy.
NANOSTRUCTURE TITANIA REINFORCED CONDUCTING POLYMER COMPOSITES
Authors: KONDAWAR S. B. , THAKARE S. R. , KHATI V. , BOMPILWAR S.
Published: June 2009

Composites of polyaniline with synthesized nanostructured titania ( TiO 2) and polyaniline with commercial TiO 2 have been in situ synthesized by oxidative chemical polymerization method. Sulfuric acid was used as dopant during the polymerization process. Sol-gel precipitates of nanostructured titania were synthesized by hydrolyzing the mixture of titanium chloride ( TiCl 3) and colloidal transparent solution of starch. Composite materials were subjected for comparison to spectroscopic and X-ray diffraction analysis. Strong coupling/interaction of titania with the imine nitrogen in polyaniline confirmed by FTIR spectral analysis. XRD shows the composite of synthesized titania with polyaniline have broaden peak as compared to that of commercial titania with polyaniline indicating particle size in the range of nanometer scale which is supported by 40 nm particle size of the synthesized titania from TEM picture. Increase in conductivity with increasing temperature was observed in both the composite materials.
THE DYNAMICS OF GaAs/AlGaAs HETEROSTRUCTURE UNDER THE TRANSVERSE MAGNETIC FIELDS AND MICROWAVE IRRADIATIONS
Authors: YANG GUI , ZHAO HONG-WEI , MENG HAO , ZHOU SHI-PING
Published: June 2009

The numerical results of a set of nonlinear equations for a modulation-doped GaAs/AlGaAs heterostructure under external fields are presented. For pure dc bias at a fixed magnetic field, we observe the self-sustained oscillations due to the traveling high electric field domain in the system. Varying the magnetic field, the width of the domain and the oscillation amplitude will be changed. By imposing the microwave irradiation, the system shows frequency locking, quasiperiodicity, and chaos depending on the amplitude and the frequency of the microwave. It is shown that these interesting oscillations are connected with the high electric field domains.
QUANTUM THEORY OF NEUTRON DIFFRACTION
Authors: WU XIANG-YAO , ZHANG BAI-JUN , LIU XIAO-JING , LIU BING , ZHANG CHUN-LI , LI JING-WU
Published: June 2009

Phenomena of electron, neutron, atomic, and molecular diffraction have been studied in many experiments, and these experiments have been explained by some theoretical works. We study neutron single and double-slit diffraction with a new quantum mechanical approach. The calculation results are compared with the experimental data obtained with cold neutrons.
ENTANGLEMENT OF A GENERAL FORMALISM Λ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES
Authors: OBADA A.-S. F. , EIED A. A. , ABD AL-KADER G. M.
Published: June 2009

We investigate the evolution of the atomic quantum entropy and the atom–field entanglement in a system of a Λ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom–field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium, and the intensity-dependent coupling functional on the entropy are analyzed.
TO THE THEORY OF ELECTROMOTIVE FORCE GENERATED IN POTENTIAL BARRIER AT ULTRAHIGH FREQUENCY FIELD
Authors: AHMETOGLU (AFRAILOV) M. , KAYNAK G. , SHAMIRZAEV S. , GULYAMOV G. , GULYAMOV A. , DADAMIRZAEV M. G. , BOYDEDAYEV S. R. , APRAILOV N.
Published: June 2009

Radio-frequency (HF) quasi-potential Φ in the field of the space charge region of contact of a metal–semiconductor is explored. At the frequency, ω, greater frequency plasma fluctuations ω0 HF quasi-potential is positive, but at frequencies ω < ω0 quasi-potential Ph is negative. VAC and Schottky barrier with provision for HF quasi-potential are calculated. It is shown that HF gives an essential contribution on EMF hot carriers when frequency of wave is less in electronic gas fluctuations in layer potential barrier.
DIRECT COMPUTATION OF STRESSES IN PLANAR LINEARIZED ELASTICITY
Authors: CIARLET PHILIPPE G. , CIARLET PATRICK
Published: June 2009

Given a simply-connected domain Ω in ℝ2, consider a linearly elastic body with [Formula: see text] as its reference configuration, and define the Hilbert space [Formula: see text] Then we recently showed that the associated pure traction problem is equivalent to finding a 2 × 2 matrix field ∊ = (∊αβ) ∈ 𝔼(Ω) that satisfies [Formula: see text] where [Formula: see text] where (Aαβστ) is the elasticity tensor, and ℓ is a continuous linear form over 𝔼(Ω) that takes into account the applied forces. Since the unknown stresses (σαβ) inside the elastic body are then given by σαβ = Aαβστ eστ, this minimization problem thus directly provides the stresses.

We show here how the above Saint Venant compatibility condition ∂11 e22 - 2∂12e12 + ∂22e11 = 0 in H-2(Ω) can be exactly implemented in a finite element space 𝔼h, which uses "edge" finite elements in the sense of J. C. Nédélec. We then establish that the unique solution ϵh of the associated discrete problem, viz., find ϵh ∈ 𝔼h such that [Formula: see text] converges to ϵ in the space [Formula: see text].

We emphasize that, by contrast with a mixed method, only the approximate stresses are computed in this approach.
APPROXIMATING IDEALIZED BOUNDARY DATA OF ELECTRIC IMPEDANCE TOMOGRAPHY BY ELECTRODE MEASUREMENTS
Authors: HYVÖNEN NUUTTI
Published: June 2009

In electric impedance tomography, one tries to recover the spatial admittance distribution inside a body from boundary measurements of current and voltage. In theoretical considerations, it is usually assumed that the available data is the infinite-dimensional Neumann-to-Dirichlet map, i.e. one assumes to be able to use any boundary current and measure the corresponding potential everywhere on the object boundary. However, in practice, the data consists of a finite-dimensional operator mapping the electrode currents onto the corresponding electrode potentials. What is more, the measurements are affected by the contact impedance at the electrode-object interfaces. In this paper, we show that the introduction of a suitable nonorthogonal projection operator makes it possible to approximate the Neumann-to-Dirichlet map by its electrode counterpart in the topology of bounded linear operators on square integrable functions, with the discrepancy depending linearly on the distance between centers of adjacent electrodes. In particular, convergence is proved without assuming that the electrodes cover all of the object boundary. The theoretical results are complemented by two-dimensional numerical experiments.
A RELAXATION METHOD VIA THE BORN–INFELD SYSTEM
Authors: TRAN QUANG HUY , BAUDIN MICHAËL , COQUEL FRÉDÉRIC
Published: June 2009

The semilinear relaxation was introduced by Jin and Xin [Comm. Pure Appl. Math.48, 235, (1995)] in order to approximate the conservation law ∂tu + ∂xf(u) = 0 for any flux function f ∈ 𝒞1 (ℝ;ℝ). In this paper, we propose an alternative relaxation technique for scalar conservation laws of the form ∂tu + ∂xu(1 - u)g(u) = 0, where g ∈ 𝒞1 ([0, 1]; ℝ) and 0 ∉ g(]0, 1[). We extend this new philosophy to an arbitrary flux function f whenever possible. Unlike the semilinear approach, the new relaxation strategy does not involve any tuning parameter, but makes use of the Born–Infeld system. Another advantage of this method is that it enables us to achieve a maximum principle on the velocities w = (1 - u)g and z = -ug, which turns out to be a physically interesting and helpful feature in the context of some two-phase flow problems.
MODELING AND ANALYSIS OF AN ANTIPLANE PIEZOELECTRIC CONTACT PROBLEM
Authors: MIGÓRSKI STANISŁAW , OCHAL ANNA , SOFONEA MIRCEA
Published: June 2009

We study a mathematical model which describes the antiplane shear deformations of a piezoelectric cylinder in frictional contact with a foundation. The process is static, the material behavior is described with a linearly electro-elastic constitutive law, the contact is frictional and the foundation is assumed to be electrically conductive. Both the friction and the electrical conductivity condition on the contact surface are described with subdifferential boundary conditions. We derive a variational formulation of the problem which is in the form of a system of two coupled hemivariational inequalities for the displacement and the electric potential fields, respectively. Then we prove the existence of a weak solution to the model and, under additional assumptions, its uniqueness. The proofs are based on an abstract result on operator inclusions in Banach spaces. Finally, we present concrete examples of friction laws and electrical conductivity conditions for which our results are valid.
PARAMETER EVALUATION OF A SIMPLE MEAN-FIELD MODEL OF SOCIAL INTERACTION
Authors: GALLO IGNACIO , BARRA ADRIANO , CONTUCCI PIERLUIGI
Published: June 2009

The aim of this work is to implement a statistical mechanics theory of social interaction, generalizing econometric discrete choice models. A class of simple mean-field discrete models is introduced and discussed both from the theoretical and phenomenological point of view. We propose a parameter evaluation procedure and test it by fitting the model against three families of data coming from different cases: the estimated interaction parameters are found to have similar positive values, giving a quantitative confirmation of the peer imitation behavior found in social psychology. Furthermore, all the values of the interaction parameters belong to the phase transition regime suggesting its possible role in the study of social systems.
THEORETICAL STUDIES OF STEREODYNAMICS FOR THE H+ + H2 (ν = 0–3, j = 0) → H2 + H+ REACTION
Authors: ZHANG CUIHUA , ZHANG WENQIN , CHEN MAODU
Published: June 2009

The stereodynamics calculation was carried out for the title reaction by quasiclassical trajectory method on the ground surface of KBNN potential energy surface. The vector correlations are determined at initial ground state and vibrational excitation of the reagent H 2. The results show that the rotational polarization is affected lightly by collision energy and strongly by reagent excitation for title reaction. The rotational alignments are almost isotropic at several collision energies on initial ground state of the reagent H 2, which means that the product rotational angular momentum is weakly polarized (or no polarized). Nevertheless, the polarization of product rotational angular momentum is enhanced remarkably at the vibrational excitations of the reagent H 2 in collision energy of 0.524 eV.
THEORETICAL STUDY OF HYDROGEN BONDED CLUSTERS OF WATER AND ISOFULMINIC ACID
Authors: ZABARDASTI ABEDIEN , KAKANEJADIFARD ALI , SALEHNASSAJ MARYAM
Published: June 2009

Ab initio and density functional calculations are used to analyze the interaction between a molecule of isofulminic acid with 1–4 molecules of water at B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) computational levels. Cooperative effect (CE) is increased with increasing size of studied clusters. Red shifts of H – O stretching frequency for complexes involving HONC as H -donor are predicted. Atom in molecules is used to analyse CE on topological parameters. Effect of molecular structure on hydrogen bond (HB) formation could be deduced from comparison of HONC – H2O and HCNO – H2O clusters, former system have more stable HB clusters.
THEORETICAL STUDY ON POTENCY AND SELECTIVITY OF NOVEL NONPEPTIDE INHIBITORS OF MATRIX METALLOPROTEINASES MMP-2 AND MMP-9
Authors: LI DAI-LIN , ZHENG QING-CHUAN , FANG XUE-XUN , JI HAI-TAO , YANG JIN-GANG , ZHANG HONG-XING
Published: June 2009

Two novel matrix metalloproteinase (MMP) inhibitors, myricetin (m) and kaempferol (k), were found and the inhibitory activity is both in decreased order towards MMP-2 and MMP-9. To understand the mechanism during the processes when inhibitors bind to MMP-2 and MMP-9, molecular modeling, docking, and density functional theory (DFT) calculations were performed. The calculated results indicated that the hydroxyls on benzene ring of the inhibitors control the binding modes between inhibitors and MMPs, thus play an important role on the potency and selectivity. Besides coordinating with the N atoms of three His residues, Zn also interacts with a hydroxyl group of inhibitors by O – Zn distances of 2.66–2.78 Å in all of the docked complexes, so that the hydroxyl acts as a weak zinc binding group (ZBG). The DFT calculated results support the above analysis. The binding affinity calculations between inhibitors and MMPs present the total interaction energies in the m-MMP < k-MMP order and the solvation energy of myricetin is less than that of kaempferol, which reflect the experimental inhibitory activity.
STUDY OF IPR FULLERENES BY COUNTING POLYNOMIALS
Authors: ASHRAFI A. R. , GHORBANI M. , JALALI M.
Published: June 2009

Let G be a graph, e = uv ∈ E( G ), nu(e) be the number of vertices of G lying closer to u than to v and nv(e) be the number of vertices of G lying closer to v than to u. The vertex PI and Szeged polynomials of the graph G are defined as PI v( G ,x) = ∑e = uv xnu (e) + nv (e) and Sz ( G ,x) = ∑e = uv xnu (e)nv (e), respectively. In this paper, these counting polynomials for an infinite family of IPR fullerenes are computed.
HOMOLYTIC C–H BOND DISSOCIATION ENERGIES OF HTPB BINDER NETWORK
Authors: LI SONGNIAN , WANG LUOXIN , LIU YONG , TUO XINLIN , WANG XIAOGONG
Published: June 2009

The C – H bond dissociation energies (BDEs) of hydroxyl-terminated polybutadiene (HTPB) binder have been computed using ab initio and density functional theory methods. Five different HTPB carbon radicals were produced by the ruptures of different C – H bonds. The structural analysis of radicals and the calculated BDEs showed that the studied C – H bonds could be divided into three groups. It was found that the weakest C – H bonds were those on the tertiary carbon atom linked to a vinyl function. The next were those on the secondary carbon attached to a vinyl function. The dissociation of these two kinds of C – H bonds determines the structure of the ultimate products during the aging of HTPB binder. The most stable C – H bonds were those in the methylene that were attached to the saturated carbon atoms.
EVALUATING PROJECT ROBUSTNESS THROUGH THE LENS OF THE BUSINESS MODEL
Authors: REGINATO JUSTIN M.
Published: June 2009

The success of large-scale innovative projects is increasingly a function of the marriage of multiple complex technologies and the ability to articulate and capture economic benefits. For corporations, the decision to pursue particular projects often hinges on the creation of, or the ability to appropriate, requisite technologies in a manner that will allow for an adequate return on investment for project shareholders. The business model is a tool that can be used to help determine whether or not a project has the necessary components for successful completion. A business model articulates a business venture's value proposition, market segment, cost and profit structure, value chain, value network, and competitive strategy. While business models are commonly used at the corporate level, they can also be applied to projects in order to convey how the potential of multiple converging technological inputs lead to the creation of sustainable economic value outputs, often in the face of technical and market uncertainty. Empirical observations from the biopharmaceutical and aerospace industries reveal that projects with incomplete business models face considerable complications, while projects with complete business models face less difficulty with respect to execution. As such, companies can use business models as a tool for making project go/no go decisions whereby only projects with complete business models are allowed to progress through the development process.
KNOWLEDGE MANAGEMENT IN A HIGH TECHNOLOGY INDUSTRY
Authors: DOS SANTOS ISABEL CRISTINA , NETO JOÃO AMATO
Published: June 2009

This study aims to contribute to the Knowledge Management Theory under a social perspective. It evaluates the Knowledge Management Cycle applied in a Brazilian high technology-based industry, a former national company which had been privatized in 1994, and passed through a huge organizational transformation and, after few years, became a market leader in one of the most competitive business sectors. Social organization covers Corporative Culture, Human Resources and Leadership aspects seen as knowledge enablers. This research used a qualitative approach and took a Knowledge Management Model developed by the Fraunhoffer Institute researchers and associates as a reference. Conclusions indicated that in order to become competitive in the new Management Model the studied company had to develop a cluster of human and business competencies. These were developed through educational processes which included personnel and leadership development. Organizational Culture had also contributed to KM process nurturing a sense of continuous improvement, customer and shareholder satisfaction.
Synchronous objects with scheduling policies
Authors: Caspi Paul , Colaço Jean-Louis , Gérard Léonard , Pouzet Marc , Raymond Pascal
Published: June 2009

This paper addresses the problem of designing and implementing complex control systems for real-time embedded software. Typical applications involve different control laws corresponding to different phases or
modes
, e.g., take-off, full flight and landing in a fly-by-wire control system. On one hand, existing methods such as the combination of Simulink/Stateflow provide powerful but unsafe mechanisms by means of imperative updates of shared variables. On the other hand, synchronous languages and tools such as Esterel or SCADE/Lustre are too restrictive and forbid to fully separate the specification of modes from their actual instantiation with a particular control automaton.

In this paper, we introduce a conservative extension of a synchronous data-flow language close to Lustre, in order to be able to define systems with modes in a more modular way, while insuring the absence of data-races. We show that such a system can be viewed as an
object
where modes are
methods
acting on a shared memory. The object is associated to a
scheduling policy
which specifies the ways methods can be called to build a valid synchronous reaction. We show that the verification of the proper use of an object reduces to a type inference problem using
row types
introduced by Wand, Rémy and Vouillon. We define the semantics of the extended synchronous language and the type system. The proposed extension has been implemented and we illustrate its use through several examples.
A compiler optimization to reduce soft errors in register files
Authors: Lee Jongeun , Shrivastava Aviral
Published: June 2009

Register file (RF) is extremely vulnerable to soft errors, and traditional redundancy based schemes to protect the RF are prohibitive not only because RF is often in the timing critical path of the processor, but also since it is one of the hottest blocks on the chip, and therefore adding any extra circuitry to it is not desirable. Pure software approaches would be ideal in this case, but previous approaches that are based on program duplication have very significant runtime overheads, and others based on instruction scheduling are only moderately effective due to local scope. We show that the problem of protecting registers inherently requires inter-procedural analysis, and intra-procedural optimization are ineffective. This paper presents a pure compiler approach, based on inter-procedural code analysis to reduce the vulnerability of registers by temporarily writing live variables to protected memory. We formulate the problem as an integer linear programming problem and also present a very efficient heuristic algorithm. Our experiments demonstrate that our proposed technique can reduce the vulnerability of the RF by 33 ~ 37% on average and up to 66%, with a small 2% increase in runtime. In addition, our overhead reduction optimizations can effectively reduce the code size overhead, by more than 40% on average, to a mere 5 ~ 6%, as compared to highly optimized binaries.
Live-range unsplitting for faster optimal coalescing
Authors: Blazy Sandrine , Robillard Benoit
Published: June 2009

Register allocation is often a two-phase approach: spilling of registers to memory, followed by coalescing of registers. Extreme live-range splitting (i.e. live-range splitting after each statement) enables optimal solutions based on ILP, for both spilling and coalescing. However, while the solutions are easily found for spilling, for coalescing they are more elusive. This difficulty stems from the huge size of interference graphs resulting from live-range splitting.

This paper focuses on coalescing in the context of extreme live-range splitting. It presents some theoretical properties that give rise to an algorithm for reducing interference graphs. This reduction consists mainly in finding and removing useless splitting points. It is followed by a graph decomposition based on clique separators. The reduction and decomposition are general enough, so that any coalescing algorithm can be applied afterwards.

Our strategy for reducing and decomposing interference graphs preserves the optimality of coalescing. When used together with an optimal coalescing algorithm (e.g. ILP), optimal solutions are much more easily found. The strategy has been tested on a standard benchmark, the optimal coalescing challenge. For this benchmark, the cutting-plane algorithm for optimal coalescing (the only optimal algorithm for coalescing) runs 300 times faster when combined with our strategy. Moreover, we provide all the optimal solutions of the optimal coalescing challenge, including the three instances that were previously unsolved.
Push-assisted migration of real-time tasks in multi-core processors
Authors: Sarkar Abhik , Mueller Frank , Ramaprasad Harini , Mohan Sibin
Published: June 2009

Multicores are becoming ubiquitous, not only in general-purpose but also embedded computing. This trend is a reflexion of contemporary embedded applications posing steadily increasing demands in processing power. On such platforms, prediction of timing behavior to ensure that deadlines of real-time tasks can be met is becoming increasingly difficult. While real-time multicore scheduling approaches help to assure deadlines based on firm theoretical properties, their reliance on task migration poses a significant challenge to timing predictability in practice. Task migration actually (a) reduces timing predictability for contemporary multicores due to cache warm-up overheads while (b) increasing traffic on the network-on-chip (NoC) interconnect.

This paper puts forth a fundamentally new approach to increase the timing predictability of multicore architectures aimed at task migration in embedded environments. A task migration between two cores imposes cache warm-up overheads on the migration target, which can lead to missed deadlines for tight real-time schedules. We propose novel micro-architectural support to migrate cache lines. Our scheme shows dramatically increased predictability in the presence of cross-core migration.

Experimental results for schedules demonstrate that our scheme enables real-time tasks to meet their deadlines in the presence of task migration. Our results illustrate that increases in execution time due to migration is reduced by our scheme to levels that may prevent deadline misses of real-time tasks that would otherwise occur. Our mechanism imposes an overhead at a fraction of the task's execution time, yet this overhead can be steered to fill idle slots in the schedule,
i.e.
, it does not contribute to the execution time of the migrated task. Overall, our novel migration scheme provides a unique mechanism capable of significantly increasing timing predictability in the wake of task migration.
Software transactional memory for multicore embedded systems
Authors: Mankin Jennifer , Kaeli David , Ardini John
Published: June 2009

Embedded systems, like general-purpose systems, can benefit from parallel execution on a symmetric multicore platform. Unfortunately, concurrency issues present in general-purpose programming also apply to embedded systems, protection from which is currently only offered with performance-limiting coarse-grained locking or error-prone and difficult-to-implement
fine-grained locking
. Transactional memory offers relief from these mechanisms, but has primarily been investigated on general-purpose systems. In this paper, we present
Embedded Software Transactional Memory
(ESTM) as a novel solution to the concurrency problem in parallel embedded applications. We investigate common software transactional memory design decisions and discuss the best decisions for an embedded platform. We offer a full implementation of an embedded STM and test it against both coarse-grained and fine-grained locking mechanisms. We find that we can meet or beat the performance of fine-grained locking over a range of application characteristics, including size of shared data, time spent in the critical section, and contention between threads. Our ESTM implementation benefits from the effective use of L1 memory, a feature which is built into our STM model but which cannot be directly utilized by traditional locking mechanisms.
Synergistic execution of stream programs on multicores with accelerators
Authors: Udupa Abhishek , Govindarajan R. , Thazhuthaveetil Matthew J.
Published: June 2009

The StreamIt programming model has been proposed to exploit parallelism in streaming applications on general purpose multicore architectures. The StreamIt graphs describe task, data and pipeline parallelism which can be exploited on accelerators such as Graphics Processing Units (GPUs) or CellBE which support abundant parallelism in hardware.

In this paper, we describe a novel method to orchestrate the execution of a StreamIt program on a multicore platform equipped with an accelerator. The proposed approach identifies, using profiling, the relative benefits of executing a task on the superscalar CPU cores and the accelerator. We formulate the problem of partitioning the work between the CPU cores and the GPU, taking into account the latencies for data transfers and the required buffer layout transformations associated with the partitioning, as an integrated Integer Linear Program (ILP) which can then be solved by an ILP solver.We also propose an efficient heuristic algorithm for the work partitioning between the CPU and the GPU, which provides solutions which are within 9.05% of the optimal solution on an average across the benchmark suite. The partitioned tasks are then software pipelined to execute on the multiple CPU cores and the Streaming Multiprocessors (SMs) of the GPU. The software pipelining algorithm orchestrates the execution between CPU cores and the GPU by emitting the code for the CPU and the GPU, and the code for the required data transfers. Our experiments on a platform with 8 CPU cores and a GeForce 8800 GTS 512 GPU show a geometric mean speedup of 6.84X with a maximum of 51.96X over a single threaded CPU execution across the StreamIt benchmarks. This is a 18.9% improvement over a partitioning strategy that maps only the filters that cannot be executed on the GPU -- the filters with state that is persistent across firings -- onto the CPU.
Specification and verification of time requirements with CCSL and Esterel
Authors: André Charles , Mallet Frédéric
Published: June 2009

The UML Profile for Modeling and Analysis of Real-Time and Embedded (MARTE) systems has recently been adopted by the OMG. Its Time Model extends the informal and simplistic Simple Time package proposed by UML2 and offers a broad range of capabilities required to model real-time systems including discrete/dense and chronometric/logical time. MARTE OMG specification introduces a Time Structure inspired by Time models of the concurrency theory and proposes a new clock constraint specification language (CCSL) to specify, within the context of UML, logical and chronometric time constraints.

This paper introduces the formal semantics of a fundamental subset of CCSL clock constraints and proposes a process to use CCSL both as a high-level specification language for UML models and as a golden model to verify the conformance of implementations with the specification.

A digital filtering video application is used as a running example to support the discussion. The application is first formally specified with CCSL and the specification is refined based on feedback from our CCSL-dedicated simulator. In a second phase, an Esterel program of the application is considered. This program is instrumented with observers derived from the CCSL specification. Esterel Studio formal verification facilities are then used to check the conformity of the Esterel implementation with the CCSL specification. A specific library of Esterel observers has been built for this purpose.