bluuebunny/crossref_metadata_2025 huggingface dataset:
BÄCKLUND TRANSFORMATION AND ANALYTIC SOLUTIONS FOR A GENERALIZED VARIABLE-COEFFICIENT MODIFIED KORTEWEG–DE VRIES MODEL FROM FLUID DYNAMICS AND PLASMAS
Authors: SUN FU-WEI , GAO YI-TIAN , ZHANG CHUN-YI , XU XIAO-GE
Published: November 2008

We investigate a generalized variable-coefficient modified Korteweg–de Vries model with perturbed factor and external force (vc-GmKdV) describing fluid dynamics and space plasmas. In this paper, we propose an extended variable-coefficient balancing-act method (Evc-BAM), which is concise and straightforward, to obtain the generalized analytic solutions including solitary wave solution of the vc-GmKdV model with symbolic computation. Meanwhile, using the Evc-BAM, we obtain an auto-Bäcklund transformation for the vc-GmKdV model on the relevant constraint conditions of the coefficient functions. Using the given auto-Bäcklund transformation, the solutions of special equations for the vc-GmKdV model are also obtained as the variable-coefficient Korteweg–de Vries (vc-KdV) equation, the generalized KdV equation with perturbed factor and external force (GKdV), the variable-coefficient modified Korteweg–de Vries (vc-mKdV) equation, and the variable-coefficient cylindrical modified Korteweg–de Vries (vc-cmKdV) equation, respectively.
FLOW EFFECT AROUND TWO SQUARE CYLINDERS ARRANGED SIDE BY SIDE USING LATTICE BOLTZMANN METHOD
Authors: RAO YONG , NI YUSHAN , LIU CHAOFENG
Published: November 2008

The flow around two square cylinders arranged side by side has been investigated through lattice Boltzmann method under different Reynolds numbers and various space ratios (s = d/D, d is the separation distance between two cylinders, D is the characteristic length) from 1.0, 1.1 to 2.7, including 18 space ratios. It is found that the flip-flop regime occurs at small space ratios and the synchronized regime occurs at large space ratios. Wide and narrow wakes at small spacing are formed and intermittently change behind the cylinders, and the biased flow in the gap is bistable. The frequency of vortex shedding is different in two wakes. The upper frequency is smaller than the lower frequency for small space ratios (s < 1.4), and the time-averaged drag and lift coefficients of cylinders are also different. When the space ratios increase, two distinct vortex streets occur behind the cylinders, and the frequency of vortex shedding is almost equal in two wakes. Also the difference of time-averaged drag and lift coefficients of the cylinders decreases with the increase in space ratios; in this case the flow shows synchronized regime. The transition between flip-flop and synchronized regimes occurs at s = 1.5. When s < 1.5, the flow shows flip-flop regime; otherwise, it shows synchronized regime. When s = 2.0 and 2.5, the curves for the time-averaged drag and lift coefficient with different Reynolds numbers are smooth. When s = 1.5 and 1.8, the curves are also smooth under Re ≤ 140, but that will be fluctuant under Re > 140 because of the nonlinear interaction between the wakes, and the instability of flow becomes stronger with the increase in Reynolds numbers. On the other hand, the vortex shedding type from the cylinder occurs in-phase when s < 2.5 and s = 2.5 for Re < 190, whereas that occurs anti-phase when s = 2.5 for Re ≥190. In addition, the pressure varies a little on the left surfaces and greatly on the right surfaces of both cylinders with the increase in Reynolds number at s = 2.5.
CHANNELING EFFECT AND IMPROVEMENT OF THE EFFICIENCY OF CHARGED PARTICLE REGISTRATION WITH CRYSTAL SCINTILLATORS
Authors: DROBYSHEVSKI E. M.
Published: November 2008

Energy of ions (recoil nuclei) channeled along definite directions in crystals is transferred to the lattice electrons mainly. In NaI(Tl) -type scintillators, this leads to increasing the light yield from ~ 10% to ~ 100% when compared with the yield for electrons of the same energy. Taking into account this effect at processing data of DAMA/ NaI experiments in Gran Sasso, which had demonstrated the year modulation of number of signals in a range of 2–6 keV of electron equivalent, reveals that DAMA/ NaI results could be caused by ~ 6×10-7 cm-2 s-1 flux of daemons (Dark Electric Matter Objects — presumably Planckian relic particles) falling out from strongly elongated heliocentric orbits with velocities of 30–50 km/s. The flux value and the 2–6 keV signal intensity agree rather well with values emerging from our former estimates and interpretations of ground-level and underground measurements.
ON ISSUES IN SWISS CHEESE COMPACTIFICATIONS
Authors: MISRA AALOK
Published: November 2008

We give a brief review of our previous works.1,2 We discuss two sets of issues. The first has to do with the possibility of getting a non-supersymmetric dS minimum without the addition of [Formula: see text]-branes as in KKLT, and axionic slow-roll inflation, in type II flux compactifications. The second has to do with the "Inverse Problem"3 and "Fake Superpotentials"4 for extremal (non)supersymmetric black holes in type II compactifications. We use (orientifold of) a "Swiss Cheese" Calabi–Yau5 expressed as a degree-18 hypersurface in WCP4[1, 1, 1, 6, 9] in the "large-volume-scenario" limit6 for the former.
LÉVY FLIGHT SUPERDIFFUSION: AN INTRODUCTION
Authors: DUBKOV A. A. , SPAGNOLO B. , UCHAIKIN V. V.
Published: November 2008

After a short excursion from the discovery of Brownian motion to the Richardson "law of four thirds" in turbulent diffusion, the article introduces the Lévy flight superdiffusion as a self-similar Lévy process. The condition of self-similarity converts the infinitely divisible characteristic function of the Lévy process into a stable characteristic function of the Lévy motion. The Lévy motion generalizes the Brownian motion on the base of the α-stable distributions theory and fractional order derivatives. Further development on this idea lies on the generalization of the Langevin equation with a non-Gaussian white noise source and the use of functional approach. This leads to the Kolmogorov's equation for arbitrary Markovian processes. As a particular case we obtain the fractional Fokker–Planck equation for Lévy flights. Some results concerning stationary probability distributions of Lévy motion in symmetric smooth monostable potentials, and a general expression to calculate the nonlinear relaxation time in barrier crossing problems are derived. Finally, we discuss the results on the same characteristics and barrier crossing problems with Lévy flights, recently obtained by different approaches.
KINETICS OF CRYSTAL GROWTH LIMITED BY RANDOM VELOCITY FIELDS
Authors: NIEMIEC M. , OLCHAWA W. , SCHIMANSKY-GEIER L. , ŁUCZKA J.
Published: November 2008

A spherical growth process controlled by velocity fluctuations of particles of a saturated solution is investigated. Velocity fluctuations are modeled by a Gaussian random field. The interface evolution is determined by a Langevin-type equation with a multiplicative random field, which in the case of the quasi-homogeneous random Gaussian field is equivalent to Fokker–Planck dynamics. We analyze numerically the Fokker–Planck equation and compare growth kinetics in the case of noisy (i.e. space-independent) fluctuations. It is shown that for a large class of spatially correlated velocity fluctuations, the growth kinetics is universal, i.e. it does not depend on the details of statistics of fluctuations.
FRACTIONAL PROCESSES: FROM POISSON TO BRANCHING ONE
Authors: UCHAIKIN V. V. , CAHOY D. O. , SIBATOV R. T.
Published: November 2008

Fractional generalizations of the Poisson process and branching Furry process are considered. The link between characteristics of the processes, fractional differential equations and Lèvy stable densities are discussed and used for the construction of the Monte Carlo algorithm for simulation of random waiting times in fractional processes. Numerical calculations are performed and limit distributions of the normalized variable Z = N/〈N〉 are found for both processes.
ON ANALYSIS AND SYNTHESIS OF ELEMENTARY AND COMPLEX INFORMATIONAL BISPECTRAL STRUCTURES
Authors: BOCHKOV GERMAN N. , GOROKHOV KONSTANTIN V.
Published: November 2008

The problem regarding shapes of bispectral peak of the triplet representing the triharmonic signal is discussed. This triplet can be used as both standard diagnostic signal for a bispectral analyzers and a simplest element of complex informational patterns of bispectrally organized signals. The problem of analyzing and measuring the parameters of bispectral peak is equally fundamental as the well-known problem concerning the shape and width of spectral line of quasi-monochromatic oscillations. The sectional area of bispectral peak restricts the limiting informational volume of complex bispectral patterns. Two models of an actual triplet with frequency fluctuations are analyzed. Universal bispectral-peak shapes are found for a triplet with proportional frequencies for the limiting cases of extremely slow and extremely fast frequency fluctuations. The phenomenon of bispectral-peak superlocalization is discovered for quasi-static fluctuations and analyzed for the most realistic model of 1/f frequency fluctuations. The experiment investigating the bispectral peak of the real high-frequency synthesizer is presented.
VOLATILITY EFFECTS ON THE ESCAPE TIME IN FINANCIAL MARKET MODELS
Authors: SPAGNOLO BERNARDO , VALENTI DAVIDE
Published: November 2008

We briefly review the statistical properties of the escape times, or hitting times, for stock price returns by using different models which describe the stock market evolution. We compare the probability function (PF) of these escape times with that obtained from real market data. Afterwards we analyze in detail the effect both of noise and different initial conditions on the escape time in a market model with stochastic volatility and a cubic nonlinearity. For this model, we compare the PF of the stock price returns, the PF of the volatility and the return correlation with the same statistical characteristics obtained from real market data.
NONLINEAR PHENOMENA IN CANONICAL STOCHASTIC QUANTIZATION
Authors: HÜFFEL HELMUTH
Published: November 2008

Stochastic quantization provides a connection between quantum field theory and statistical mechanics, with applications especially in gauge field theories. Euclidean quantum field theory is viewed as the equilibrium limit of a statistical system coupled to a thermal reservoir. Nonlinear phenomena in stochastic quantization arise when employing nonlinear Brownian motion as an underlying stochastic process. We discuss a novel formulation of the Higgs mechanism in QED.
ANALYSIS OF DISCRETE SIGNALS WITH STOCHASTIC COMPONENTS USING FLICKER NOISE SPECTROSCOPY
Authors: TIMASHEV SERGE F. , POLYAKOV YURIY S.
Published: November 2008

The problem of information extraction from discrete stochastic time series, produced with some finite sampling frequency, using flicker-noise spectroscopy, a general framework for information extraction based on the analysis of the correlation links between signal irregularities and formulated for continuous signals, is discussed. It is shown that the mathematical notions of Dirac δ- and Heaviside θ-functions used in the analysis of continuous signals may be interpreted as high-frequency and low-frequency stochastic components, respectively, in the case of discrete series. The analysis of electroencephalogram measurements for a teenager with schizophrenic symptoms at two different sampling frequencies demonstrates that the "power spectrum" and difference moment contain different information in the case of discrete signals, which was formally proven for continuous signals. The sampling interval itself is suggested as an additional parameter that should be included in general parameterization procedures for real signals.
STATISTICAL MEMORY OF MEG SIGNALS AT PHOTOSENSITIVE EPILEPSY
Authors: YULMETYEV R. M. , KHUSAENOVA E. V. , YULMETYEVA D. G. , HÄNGGI P. , SHIMOJO S. , WATANABE K. , BHATTACHARYA J.
Published: November 2008

Here we discuss the remarkable role of the statistical memory effects in the human brain functioning at photosensitive epilepsy (PSE). We have analyzed three independent statistical memory quantifiers for the magnetoencephalographic (MEG) signals. These quantifiers reflect the dynamical characteristics of neuromagnetic brain responses to a flickering stimulus of different color combinations. Results for a group of control subjects are contrasted with those from a patient with PSE. The emergence of the strong memory and the transition to a regular and robust regime of chaotic behavior of the signals in separate areas is characteristic for a patient with PSE versus a healthy brain.
USING BERRY FUNCTION MODEL TO INVESTIGATE STATISTICS OF ACOUSTIC NOISE WAVE FLOW
Authors: LAPINOVA S. A.
Published: November 2008

It is shown that Berry model may be successfully applied to study noise wave field properties. The correlation function of the waves stream was obtained and its probability density was analyzed in the case of simple distributions of the wave vector parameters.
THERMODYNAMICS OF DISPERSING BILLIARDS WITH TIME-DEPENDENT BOUNDARIES
Authors: LOSKUTOV ALEXANDER , CHICHIGINA OLGA , RYABOV ALEXEI
Published: November 2008

By means of a thermodynamic approach we analyze billiards in the form of the Lorentz gas with the open horizon. For periodic and stochastic oscillations of the scatterers, the average velocity of the particle ensemble as a function of time is analytically obtained. It is shown that the consequence of such oscillations is Fermi acceleration which is larger for periodic oscillations. The described results do not depend on the size of scatterers and their position. Only the property of the horizon openness is necessary. It is found that the developed thermodynamic approach is in a very good agreement with the results of the direct numerical simulations at which the corresponding billiard map is used.
SPECTRAL-CORRELATION ANALYSIS OF COUPLED CHAOTIC SELF-SUSTAINED OSCILLATORS
Authors: ZAKHAROVA A. S. , VADIVASOVA T. E. , ANISHCHENKO V. S.
Published: November 2008

Spectra and autocorrelation functions are studied in a system of two coupled self-sustained chaotic oscillators. We show that spectral and correlation characteristics are connected with partial effective phase diffusion coefficients. The evolution of spectra and diffusion coefficients are considered from the asynchronous regime to the regime of synchronous chaos. We draw the analogy between spectral characteristics of coupled chaotic oscillators and noisy coupled periodic oscillators.
ASYMPTOTIC AND NUMERICAL ANALYSIS OF THE EIGENVALUE PROBLEM FOR A CLAMPED CYLINDRICAL SHELL
Authors: DA VEIGA L. BEIRÃO , HAKULA H. , PITKÄRANTA J.
Published: November 2008

We are interested in the asymptotic analysis of the eigenvalue problem of clamped cylindrical shells. We analyze the lowest eigenvalues as a function of the shell thickness t, the asymptotic behavior of the respective eigenfunctions, and show how the different displacement components and parts of the energy scale in t. As a consequence, we are able to single out the numerical difficulties of the problem, which, surprisingly for a formally bending inhibited problem, include the presence of locking. Extensive numerical tests are included.
A NEW REPRESENTATION OF THE LOCAL VOLATILITY SURFACE
Authors: RODRIGO MARIANITO R. , MAMON ROGEMAR S.
Published: November 2008

In this paper, we address the problem of recovering the local volatility surface from option prices consistent with observed market data. We revisit the implied volatility problem and derive an explicit formula for the implied volatility together with bounds for the call price and its derivative with respect to the strike price. The analysis of the implied volatility problem leads to the development of an ansatz approach, which is employed to obtain a semi-explicit solution of Dupire's forward equation. This solution, in turn, gives rise to a new expression for the volatility surface in terms of the price of a European call or put. We provide numerical simulations to demonstrate the robustness of our technique and its capability of accurately reproducing the volatility function.
Gasping During Cardiac Arrest in Humans Is Frequent and Associated With Improved Survival
Authors: Bobrow Bentley J. , Zuercher Mathias , Ewy Gordon A. , Clark Lani , Chikani Vatsal , Donahue Dan , Sanders Arthur B. , Hilwig Ronald W. , Berg Robert A. , Kern Karl B.
Published: November 2008

Background—

The incidence and significance of gasping after cardiac arrest in humans are controversial.

Methods and Results—

Two approaches were used. The first was a retrospective analysis of consecutive confirmed out-of-hospital cardiac arrests from the Phoenix Fire Department Regional Dispatch Center text files to determine the presence of gasping soon after collapse. The second was a retrospective analysis of 1218 patients with out-of-hospital cardiac arrests in Arizona documented by emergency medical system (EMS) first-care reports to determine the incidence of gasping after arrest in relation to the various EMS arrival times. The primary outcome measure was survival to hospital discharge. An analysis of the Phoenix Fire Department Regional Dispatch Center records of witnessed and unwitnessed out-of-hospital cardiac arrests with attempted resuscitation found that 44 of 113 (39%) of all arrested patients had gasping. An analysis of 1218 EMS-attended, witnessed, out-of-hospital cardiac arrests demonstrated that the presence or absence of gasping correlated with EMS arrival time. Gasping was present in 39 of 119 patients (33%) who arrested after EMS arrival, in 73 of 363 (20%) when EMS arrival was <7 minutes, in 50 of 360 (14%) when EMS arrival time was 7 to 9 minutes, and in 25 of 338 (7%) when EMS arrival time was >9 minutes. Survival to hospital discharge occurred in 54 of 191 patients (28%) who gasped and in 80 of 1027 (8%) who did not (adjusted odds ratio, 3.4; 95% confidence interval, 2.2 to 5.2). Among the 481 patients who received bystander cardiopulmonary resuscitation, survival to hospital discharge occurred among 30 of 77 patients who gasped (39%) versus only 38 of 404 among those who did not gasp (9%) (adjusted odds ratio, 5.1; 95% confidence interval, 2.7 to 9.4).

Conclusions—

Gasping or abnormal breathing is common after cardiac arrest but decreases rapidly with time. Gasping is associated with increased survival. These results suggest that the recognition and importance of gasping should be taught to bystanders and emergency medical dispatchers so as not to dissuade them from initiating prompt resuscitation efforts when appropriate.
Diabetic Hypertensive Leptin Receptor–Deficient db/db Mice Develop Cardioregulatory Autonomic Dysfunction
Authors: da Costa Goncalves Andrey C. , Tank Jens , Diedrich André , Hilzendeger Aline , Plehm Ralph , Bader Michael , Luft Friedrich C. , Jordan Jens , Gross Volkmar
Published: November 2008

Leptin receptor–deficient db/db mice develop human type 2 diabetes mellitus, hypertension, and obesity with disrupted circadian blood pressure (BP) rhythm. Whether leptin is the sole mechanism mediating autonomic imbalance and hypertension is unclear. To explore this notion further, we measured BP by radiotelemetry combined with fast Fourier transformation and assessed autonomic function pharmacologically before and after renin-angiotensin system blockade with enalapril. The resting period BP (117±3 versus 108±1.0 mm Hg) and heart rate (HR; 488±12 versus 436±8 bpm) were higher in db/db mice compared with db/+ mice. BP and HR amplitudes were lower in db/db mice compared with db/+ mice. BP response to trimetaphan (−43±5 versus −27±3 mm Hg) and HR response to metoprolol (−59±12 versus −5±4 bpm) were greater in db/db mice than in db/+ mice. The HR response to atropine was blunted in db/db mice (59±17 versus 144±24 bpm), as were baroreflex sensitivity and HR variability. Enalapril improved autonomic regulation in db/db mice. Stimulation of central α-2 adrenoreceptors enhanced both parasympathetic HR control and baroreflex sensitivity in db/db mice. We suggest that functional, rather than structural, α-2 adrenoceptor changes and the renin-angiotensin system are involved in the increased sympathetic and decreased parasympathetic tones in db/db mice. Our data suggest that db/db mice exhibit features found in humans with type 2 diabetic autonomic neuropathy and could serve as a model for this complication.
A New Value of the von Kármán Constant: Implications and Implementation
Authors: Andreas Edgar L.
Published: November 2008

The von Kármán constant k occurs throughout the mathematics that describe the atmospheric boundary layer. In particular, because k was originally included in the definition of the Obukhov length, its value has both explicit and implicit effects on the functions of Monin–Obukhov similarity theory. Although credible experimental evidence has appeared sporadically that the von Kármán constant is different than the canonical value of 0.40, the mathematics of boundary layer meteorology still retain k = 0.40—probably because the task of revising all of this math to implement a new value of k is so daunting. This study therefore outlines how to make these revisions in the nondimensional flux–gradient relations; in variance, covariance, and dissipation functions; and in structure parameters of Monin–Obukhov similarity theory. It also demonstrates how measured values of the drag coefficient (CD), the transfer coefficients for sensible (CH) and latent (CE) heat, and the roughness lengths for wind speed (z0), temperature (zT), and humidity (zQ) must be modified for a new value of the von Kármán constant. For the range of credible experimental values for k, 0.35–0.436, revised values of CD, CH, CE, z0, zT, and zQ could be quite different from values obtained assuming k = 0.40, especially if the original measurements were made in stable stratification. However, for the value of k recommended here, 0.39, no revisions to the transfer coefficients and roughness lengths should be necessary. Henceforth, use the original measured values of transfer coefficients and roughness lengths but do use similarity functions modified to reflect k = 0.39.
Unity in Christ: The Purpose of Ephesians
Authors: Barnard Jody A.
Published: November 2008

Discerning the purpose of Ephesians is a notoriously difficult task since the letter lacks the necessary specificity for identifying a particular life-setting to explain its composition. This article explores the extent to which recent scholarship has disclosed the rationale behind this letter. Various contributions are considered, evaluated and integrated as one seeks to arrive at an understanding of the purpose of Ephesians.
`The Stilling of the Sea' and the Imagination of Place in a Cornish Fishing Village
Authors: Lawrence Louise J.
Published: November 2008

This article documents the contextualizing of the `Stilling of the Sea' in the Cornish fishing village of Newlyn. The images of `the boat', `the journey to the other side', `the sea and storm' and `the sailors' offered vivid touchstones not only with past experiences but also compelling incentives for future development.
The Influence of Fiber Treatment on the Performance of Bagasse Fiber-Reinforced Polymer Composite
Authors: Acharya S.K. , Punya Priya Mishra  , Mehar S.K.
Published: November 2008

Bagasse fiber is a residue of the sugar cane milling process. In this research bagasse fiber has been used as a reinforcing component in epoxy resin to open up further possibilities in waste management. The chemical treatment acetylation was carried out to modify the fiber properties. The effect of fiber treatment on the mechanical properties such as flexural strength has been studied. It has been shown that treated fiber composites shows improved strength. SEM investigation also indicates that the surface modifications improve the fiber—matrix interaction.
A SEM-Fractographic Study of Dynamic Crack Propagation Effects in Particulate Epoxy Systems under Impact Loading Conditions
Authors: Kytopoulos V.N. , Badalouka B.G. , Bourkas G.D. , Sideridis E.
Published: November 2008

In this complex study an attempt was made on the one hand to analyze and understand in a systematic way the exact nature of the formation of certain characteristic energy dissipation-induced fractographic features and patterns/markings revealed by scanning electron microscopy (SEM) in particulate epoxy systems under impact (dynamic) loading conditions, and on the other hand to correlate these patterns and features with relevant crack propagation effects. For this scope a combined approach consisting of a qualitative as well as a semiquantitative analysis was employed. In the qualitative analytical approach it was shown that depending on the actual velocity and direction of crack propagation the above observed fractographic entities can be correlated to certain highly localized energy dissipative processes at front-failures as well as to local inertial molecular mass effects.

Depending on the changes in the velocity and direction of propagation, the associated effects may be controlled by two basic processes: the single crack front and the multiple crack front splitting. The first process seemed to be governed by a shear toughness-biased system, whereas the second one used a critical strain energy release rate subcracking mechanism. Under certain conditions both processes may be influenced by inertial molecular effects in promoting the formation of relative-smooth fracture surfaces.

The increased presence of particles tends to restrict an increase in the surface roughness due to energy dissipation-induced crack retardation effects. The presence of the notch tends to lower the fracture surface roughness compared to notch-free specimens and also to suppress the occurrence of certain elastic as well as viscoelastic-plastic crack delay effects observed in notch-free specimens in function of particle volume fraction.

Based on relevant kinematics-aided modeling and impact energy measurements it seems possible to explain, by a gross semi-quantitative approach, the above particles and notch effects. In this context it seems plausible that the existence of a defect-induced fracturing time spectrum of the propagating crack front, in combination with the `notch-induced shift' behavior of this spectrum, can be valuable for some approximating explanations of the above notch effects and in general the `kinematics' of the surface roughness formation.
Preparation and Physico-Chemical Study of Glass—Sisal (Treated—Untreated) Hybrid Composites of Bisphenol-C based Mixed Epoxy—Phenolic Resins
Authors: Patel V.A. , Parsania P.H.
Published: November 2008

Glass—sisal (treated and untreated) composites of mixed matrix material (25 wt% epoxy resin of bisphenol-C (EBC) and 25 wt% bisphenol-C-formaldehyde (BCF) of glass—sisal fibers) were prepared by hand lay-up technique at 150°C under 7.6 MPa pressure for 2 h. Hydrophilic character of the sisal fibers was reduced by acrylation of alkali-treated fibers with acrylic acid. Tensile strength, flexural strength, electric strength, and volume resistivity were increased from 26.4 to 35.3 MPa (33.7%), 46.7—64.1 MPa (37.3%), 1.41—1.93 kV/mm (36.9%), and 1.27 × 1012—1.81 × 1012 Ω-cm (42.5%), respectively, on alkali treatment and acrylation. The edges of 5 × 5 cm2 specimens were sealed with matrix material and subjected to distilled water and 10% each of aq. HCl and aq. NaCl solutions at room temperature for water uptake study. The equilibrium water uptake is reduced from 10.07—8.47% in water, 7.91—6.4% in 10% aq. NaCl and 12.13—11.00% in 10% aq. HCl on acrylation. Diffusivity was found to increase from 0.71— 0.82 × 10− 11 in water, 1.02—1.73 × 10−11 in 10% aq. NaCl and 0.4—0.59 × 10−11 m 2/s in 10% aq. HCl. Drastic reduction in water uptake is due to replacement of hydrophobic vinyl ester groups. No effect of boiling water is observed on stability of composites. Saturation time in boiling water reduced 24 times without any damage to the untreated and treated sisal—glass fiber composites, respectively. Composites may be useful for low load bearing applications and also in harsh acidic and saline environments.
Preparation and Properties of Palm Oil-Based Rigid Polyurethane Nanocomposite Foams
Authors: Chuayjuljit S. , Maungchareon A. , Saravari O.
Published: November 2008

In this study, palm oil-based polyurethane (PU)/montmorillonite (MMT) nanocomposite foams were produced via an in situ polymerization method. The palm oil-based polyol synthesized by transesterification reaction of palm oil and pentaerythritol was reacted with commercial polymeric diphenylmethane diisocyanate in the presence of water (blowing agent), N,N-dimethylcyclohexylamine (catalyst), polydimethylsiloxane (surfactant) and MMT to produce rigid PU nanocomposite foams. The obtained foams containing different MMT contents (1, 3, and 5 wt%) were characterized for their structure, morphology, density, hardness, compressive strength and thermal stability. X-ray diffraction patterns revealed that the nanocomposites formed were exfoliated. Scanning electron micrographs showed that the cells of the obtained PU foams were closed cells. The nanocomposite foams showed a higher number of cells with a smaller cell size as the amount of MMT increased. The density and the compressive strength of the foams increased with the increasing amount of MMT and were in the range of 38.5—46.6 kg/m3 and 116.7—171.6 kPa, respectively. Moreover, addition of MMT also improved the thermal stability of the foams.
Probiotic Prophylaxis in Predicted Severe Acute Pancreatitis: A Randomised, Double‐Blind, Placebo‐Controlled Trial
Authors: Venkatesan Thangam
Published: November 2008

Background: Infectious complications and associated mortality are a major concern in acute pancreatitis. Enteral administration of probiotics could prevent infectious complications, but convincing evidence is scarce. Our aim was to assess the effects of probiotic prophylaxis in patients with predicted severe acute pancreatitis. Methods: In this multicenter randomized, double‐blind, placebo‐controlled trial, 298 patients with predicted severe acute pancreatitis (Acute Physiology and Chronic Health Evaluation [APACHE II] score ≥8, Imrie score ≥3, or C‐reactive protein> 150 mg/L) were randomly assigned within 72 h of onset of symptoms to receive a multispecies probiotic preparation (n = 153) or placebo (n = 145), administered enterally twice daily for 28 days. The primary endpoint was the composite of infectious complications—i.e., infected pancreatic necrosis, bacteremia, pneumonia, urosepsis, or infected ascites—during admission and 90‐day follow‐up. Analyses were by intention to treat. This study is registered, number ISRCTN38327949. Findings: One person in each group was excluded from analyses because of incorrect diagnoses of pancreatitis; thus, 152 individuals in the probiotics group and 144 in the placebo group were analysed. Groups were much the same at baseline in terms of patients' characteristics and disease severity. Infectious complications occurred in 46 (30%) patients in the probiotics group and 41 (28%) of those in the placebo group (relative risk 1.06, 95% CI 0.75–1.51). 24 (16%) patients in the probiotics group died, compared with nine (6%) in the placebo group (relative risk 2.53, 95% CI 1.22–5.25). Nine patients in the probiotics group developed bowel ischaemia (eight with fatal outcome), compared with none in the placebo group (p = 0.004). Interpretation: In patients with predicted severe acute pancreatitis, probiotic prophylaxis with this combination of probiotic strains did not reduce the risk of infectious complications and was associated with an increased risk of mortality. Probiotic prophylaxis should therefore not be administered in this category of patients. (Lancet. 2008;371(9613):651‐659)

MGH Besselink, HC van Santvoort, E Buskens, et al, for the Dutch Acute Pancreatitis Study Group
Evaluation of the selected barrier properties of retinal pigment epithelial cell line ARPE-19 for an in-vitro blood-brain barrier model
Authors: Nevala H , Ylikomi T , Tähti H
Published: November 2008

In-vitro models that maintain complex transport mechanisms and structural properties associated with the blood-brain barrier in vivo would be useful in drug permeability and neurotoxicological studies. To evaluate the suitability of a human retinal pigment epithelial cell line for a blood-brain barrier model, we have compared the barrier properties of the human retinal pigment epithelial cell line ARPE-19, the human colonic adenocarcinoma cell line Caco-2, and primary porcine microvessel endothelial cells. The tight junction proteins occludin and ZO-1 were stained immunocytochemically. The paracellular ionic permeability was evaluated by measuring the trans-epithelial or trans-endothelial electric resistance. To evaluate the active transport mechanisms, the existence and the activity of the efflux transporters, P-glycoprotein and multidrug resistance-associated proteins, were studied. All the cell types in this study stained positively for occludin and ZO-1. However, the trans-endothelial electric resistance of ARPE-19 cells was low compared with that of primary porcine microvessel endothelial cell and Caco-2 cells. In addition, both the P-glycoprotein expression and its activity in ARPE-19 cells were low. In conclusion, the barrier properties of the human ARPE-19 cell line were not satisfactory for a blood-brain barrier model. For future studies, it is important to develop a human brain endothelial cell line with expression of the complex in-vivo properties of the blood-brain barrier.
Safety evaluation of Elixir paregorico® in healthy volunteers: a phase I study
Authors: de Moraes MEA , Bezerra MM , Bezerra FAF , de Moraes RA , Cavalcanti PP , Uchoa CRA , Lima FAV , Odorico de Moraes M
Published: November 2008

A liquid alcoholic extract of Papaver somniferum named Elixir Paregorico® is extensively used for diarrheal diseases in Brazil. Its increased popularity has brought concerns and fears over the safety of this herbal product. Given the lack of investigative clinical studies, in this regard, this study investigated whether Elixir Paregorico® administration causes any noticeable toxic effects in healthy volunteers. In all, 28 middle-aged healthy male ( n = 14) and female ( n = 14) were enrolled. After screening and a washout period, eligible subjects received four oral doses per day of Elixir Paregorico® (3 mL diluted in 30 mL of water) over a 10-day period. Altogether, all 28 participants completed the study. The results of hematological and biochemical tests performed pre and post-treatment were within the normal range. In both male and female volunteers, there were no statistical differences ( P > 0.05) in the results of clinical and laboratory tests performed at screening, on 5th and 10th day visits, and at final assessment. Although mild adverse events were related, which subsided spontaneously, no serious untoward reactions were reported following Elixir Paregorico® administration. To our knowledge, this is the first demonstration that Elixir Paregorico® administered four times a day for 10 days is safe and does not cause any noticeable toxic effect in healthy volunteers.
Association of pesticide exposure, vaccination response, and interleukin-1 gene polymorphisms
Authors: Baranska M , Van Amelsvoort L , Birindelli S , Fustinoni S , Corsini E , Liesivuori J , Van Loveren H
Published: November 2008

We performed a cross-sectional study involving workers from four European countries in which exposure to pesticides and immune parameters were evaluated over a short period of time. The total study population consisted of 238 workers occupationally exposed to pesticides and 198 nonoccupationally exposed workers. The study showed that pesticide exposure at levels encountered by workers under different conditions in Europe did not affect the ability of the immune system to respond to vaccination. We could, however, identify individuals within the group of pesticide exposed workers who were genetically characterized by the 2.2 IL-1α polymorphism and who showed a lower antibody response, pointing out the importance of the understanding of genetic variability and the interaction between genetic and environmental factors in the identification of high-risk individuals, which may eventually lead to preventive measures.
Some Notes on Microcracking, Softening, Localization, and Size Effects
Authors: Van Mier Jan G.M. , Man Hau-Kit
Published: November 2008

Fracture of concrete and other brittle disordered materials is a complex process involving microcracks (that can be arrested by the heterogeneous material structure) and macrocracks (that lead to failure of the structure/specimen). The process is basically the same for any type of loading as long as global failure is not ductile (for these materials: usually at high confinement). The focus in the article is on mode I cracking, showing similarities of the fracture process for other loading cases, in particular (multiaxial) compression. The fracture process in tension can be sub-divided in four stages: elastic, microcracking, macrocrack growth (localization), and bridging. Improvements in simulations over two decades are shown. The various fracture stages can be simulated using models that allow for local brittle mode I fracture and where the material structure has been included. At present simulations in 3D, with great amount of detail such as realistic particle distributions and particle shapes can be carried out routinely. One example is shown, focusing on size effects of fracture strength in 3-point bending. The results reveal that the microcrack population at peak-load is the fracture pattern to consider, and not the localized macrocrack at the end of the softening branch. The consequence is that size-effect must be expressed in terms of log(nominal stress) versus log(volume) diagrams, which makes the formulation more general.
Characterization of Incipient Spall Damage in Shocked Copper Multicrystals
Authors: Peralta P. , DiGiacomo S. , Hashemian S. , Luo S.-N. , Paisley D. , Dickerson R. , Loomis E. , Byler D. , Mcclellan K.J. , D'Armas H.
Published: November 2008

Correlations between spall damage and local microstructure were investigated in multicrystalline copper samples via impact tests conducted with laser-driven plates at low pressures (2—6 GPa). The copper samples had a large grain size as compared to the thickness, which was either 200 or 1000 μm, to isolate the effects of microstructure on the local response. Velocity interferometry was used to measure the bulk response of the free-surface velocity of the samples to monitor traditional spall tensile failure and to examine heterogeneities on the shock response due to microstructure variability from sample to sample. The shock pressure, dynamic yield strength and spall strength were determined from the measured velocity history via standard hydrodynamic approximations, while the effect of strength was explored via 1D hydrocode calculations. Electron Backscattering Diffraction, both in-plane and through-thickness, was used to relate crystallography to the presence of porosity around microstructural features such as grain boundaries and triple points. It was found that the dynamic yield strength measured from velocity histories in different samples correlated well with the crystallographic dependence reported for the dynamic yield strength in single crystals. Transgranular damage dominated in thin specimens with 230 μm grain size, where porosity appeared close to, but not exactly at, grain boundaries. However, a transition to dominant intergranular damage was observed as the grain size was reduced to 150 μm. Thick specimens (450 μm grain size) showed both modes, with intergranular damage found mostly where grains were smaller than average and the sites for preferred damage nucleation in these samples included grain boundaries and triple points. In particular, twin boundaries, especially tips of terminated twins, showed a large mismatch in surface displacements on the diagnostic surface as compared to the surrounding grains as well as a tendency for damage localization on the through-thickness sections.
Results of a phase IIa clinical trial of an anti-inflammatory molecule, chaperonin 10, in multiple sclerosis
Authors: Broadley SA , Vanags D , Williams B , Johnson B , Feeney D , Griffiths L , Shakib S , Brown G , Coulthard A , Mullins P , Kneebone C
Published: November 2008

Background

Chaperonin 10 (Cpn10) is a mitochondrial molecule involved in protein folding. The aim of this study was to determine the safety profile of Cpn10 in patients with multiple sclerosis (MS).

Methods

A total of 50 patients with relapse-remitting or secondary progressive MS were intravenously administered 5 mg or 10 mg of Cpn10 weekly for 12 weeks in a double-blind, randomized, placebo controlled, phase II trial. Clinical reviews, including Expanded Disability Status Scale and magnetic resonance imaging (MRI) with Gadolinium, were undertaken every 4 weeks. Stimulation of patient peripheral blood mononuclear cells with lipopolysaccharide ex vivo was used to measure the in vivo activity of Cpn10.

Results

No significant differences in the frequency of adverse events were seen between treatment and placebo arms. Leukocytes from both groups of Cpn10-treated patients produced significantly lower levels of critical proinflammatory cytokines. A trend toward improvement in new Gadolinium-enhancing lesions on MRI was observed, but this difference was not statistically significant. No differences in clinical outcome measures were seen.

Conclusions

Cpn10 is safe and well tolerated when administered to patients with MS for 3 months, however, a further extended phase II study primarily focused on efficacy is warranted.
Discipline of the catwalk
Authors: Mears Ashley
Published: November 2008

The work of women's fashion modeling is a disciplining labor process in which female bodily capital is transformed into a cultural commodity. Based on participant observation of the New York modeling industry, this article examines how models are made into `looks'. Models are subject to intense surveillance, a discourse of infantilization, and uncertain judging criteria. This labor process typifies the politics of gender, in which women exercise power over themselves insofar as they internalize and pursue the glamour of their regime. Models are mobilized into looks by adhering to floating norms, a concept introduced to describe discipline under market constraints. Models undergo a disciplining process that is at once a response to the instabilities of gender and to the vagaries of cultural production markets. The institutionalized market context and the impossibility of idealized femininity together draw linkages between the uncertainties of gender and of markets, two spheres that intertwine in the production of fashion models.
Hanging out and hanging about
Authors: Woodward Kath
Published: November 2008

This article offers reflection on the relationship between the researcher and the field of research, within the sport of men's boxing, which is strongly characterized by polarized oppositions: between winning and losing, success and failure, women and men and, perhaps most importantly for the researcher, `insiders' and `outsiders'. It is this interrelationship between `insiders' and `outsiders' and the embodiment, not only of the practitioners of the sport but also the embodied presence of the researcher, which is used here to explore methodological questions about the research process and debates about how the researcher is situated in relation to the research site, by addressing questions about ontological complicity that are implicated in the distinction between `hanging out' and `hanging about' at the gym and as part of the culture of boxing.
The Brussels Declaration: the need for change in asthma management
Authors: Holgate S. , Bisgaard H. , Bjermer L. , Haahtela T. , Haughney J. , Horne R. , McIvor A. , Palkonen S. , Price D. B. , Thomas M. , Valovirta E. , Wahn U.
Published: November 2008

Asthma is a highly prevalent condition across Europe and numerous guidelines have been developed to optimise management. However, asthma can be neither cured nor prevented, treatment choices are limited and many patients have poorly controlled or uncontrolled asthma.

The Brussels Declaration on Asthma, sponsored by The Asthma, Allergy and Inflammation Research Charity, was developed to call attention to the shortfalls in asthma management and to urge European policy makers to recognise that asthma is a public health problem that should be a political priority.

The Declaration urges recognition and action on the following points: the systemic inflammatory component of asthma should be better understood and considered in assessments of treatment efficacy; current research must be communicated and responded to quickly; the European Medicines Agency guidance note on asthma should be updated; “real world” studies should be funded and results used to inform guidelines; variations in care across Europe should be addressed; people with asthma should participate in their own care; the impact of environmental factors should be understood; and targets should be set for improvement.

The present paper reviews the evidence supporting the need for change in asthma management and summarises the ten key points contained in the Brussels Declaration.
Structural descriptor database: a new tool for sequence-based functional site prediction
Authors: Bernardes Juliana S , Fernandez Jorge H , Vasconcelos Ana Tereza R
Published: November 2008

Background

The Structural Descriptor Database (SDDB) is a web-based tool that predicts the function of proteins and functional site positions based on the structural properties of related protein families. Structural alignments and functional residues of a known protein set (defined as the training set) are used to build special Hidden Markov Models (HMM) called HMM descriptors. SDDB uses previously calculated and stored HMM descriptors for predicting active sites, binding residues, and protein function. The database integrates biologically relevant data filtered from several databases such as PDB, PDBSUM, CSA and SCOP. It accepts queries in fasta format and predicts functional residue positions, protein-ligand interactions, and protein function, based on the SCOP database.

Results

To assess the SDDB performance, we used different data sets. The Trypsion-like Serine protease data set assessed how well SDDB predicts functional sites when curated data is available. The SCOP family data set was used to analyze SDDB performance by using training data extracted from PDBSUM (binding sites) and from CSA (active sites). The ATP-binding experiment was used to compare our approach with the most current method. For all evaluations, significant improvements were obtained with SDDB.

Conclusion

SDDB performed better when trusty training data was available. SDDB worked better in predicting active sites rather than binding sites because the former are more conserved than the latter. Nevertheless, by using our prediction method we obtained results with precision above 70%.