bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Heavy Drinking, Binge Drinking, and Family History of Alcoholism on Regional Brain Metabolites
Authors: Meyerhoff D. J. , Blumenfeld R. , Truran D. , Lindgren J. , Flenniken D. , Cardenas V. , Chao L. L. , Rothlind J. , Studholme C. , Weiner M. W.
Published: April 2004

Abstract: Background: The main goals are to investigate the effects of chronic active heavy drinking on N‐acetylaspartate (NAA) and other metabolites throughout the brain and to determine whether they are affected by family history (FH) of alcoholism and long‐term drinking pattern.

Methods: Forty‐six chronic heavy drinkers (HD) and 52 light drinkers (LD) were recruited from the community and compared on measures of regional brain structure using magnetic resonance imaging and measures of common brain metabolites in gray matter (GM) and white matter (WM) of the major lobes, subcortical nuclei, brainstem, and cerebellum using short–echo time magnetic resonance spectroscopic imaging. Regional atrophy‐corrected levels of NAA, myoinositol (mI), creatine, and choline‐containing metabolites were compared as a function of group, FH of alcoholism, and bingeing.

Results: Frontal WM NAA was lower in FH‐negative HD than FH‐positive HD and tended to be lower in women than men. Creatine‐containing metabolites in parietal GM were higher in HD than LD. FH‐negative compared with FH‐positive HD also had more mI in the brainstem and tended to have lower NAA and more mI in frontal GM. Although parietal GM NAA was not significantly lower in HD than LD, it was lower in non–binge drinkers than bingers. Frontal WM NAA was lower in HD than LD, with the difference driven by a small number of women, FH‐negative HD, and older age. Lower frontal WM NAA in HD was associated with lower executive and working memory functions and with lower P3b amplitudes at frontal electrodes.

Conclusions: Community‐dwelling HD who are not in alcoholism treatment have brain metabolite changes that are associated with lower brain function and are likely of behavioral significance. Age, FH, and binge drinking modulate brain metabolite abnormalities. Metabolite changes in active HD are less pronounced and present with a different spatial and metabolite pattern than reported in abstinent alcoholics.
The specificity of alcohol dehydrogenase with cis‐retinoids
Authors: Martras Sílvia , Alvarez Rosana , Martínez Susana E. , Torres Dámaso , Gallego Oriol , Duester Gregg , Farrés Jaume , de Lera Angel R. , Parés Xavier
Published: April 2004

Studies in knockout mice support the involvement of alcohol dehydrogenases ADH1 and ADH4 in retinoid metabolism, although kinetics with retinoids are not known for the mouse enzymes. Moreover, a role of alcohol dehydrogenase (ADH) in the eye retinoid interconversions cannot be ascertained due to the lack of information on the kinetics with 11‐cis‐retinoids. We report here the kinetics of human ADH1B1, ADH1B2, ADH4, and mouse ADH1 and ADH4 with all‐trans‐, 7‐cis‐, 9‐cis‐, 11‐cis‐ and 13‐cis‐isomers of retinol and retinal. These retinoids are substrates for all enzymes tested, except the 13‐cis isomers which are not used by ADH1. In general, human and mouse ADH4 exhibit similar activity, higher than that of ADH1, while mouse ADH1 is more efficient than the homologous human enzymes. All tested ADHs use 11‐cis‐retinoids efficiently. ADH4 shows much higher kcat/Km values for 11‐cis‐retinol oxidation than for 11‐cis‐retinal reduction, a unique property among mammalian ADHs for any alcohol/aldehyde substrate pair. Docking simulations and the kinetic properties of the human ADH4 M141L mutant demonstrated that residue 141, in the middle region of the active site, is essential for such ADH4 specificity. The distinct kinetics of ADH4 with 11‐cis‐retinol, its wide specificity with retinol isomers and its immunolocalization in several retinal cell layers, including pigment epithelium, support a role of this enzyme in the various retinol oxidations that occur in the retina. Cytosolic ADH4 activity may complement the isomer‐specific microsomal enzymes involved in photopigment regeneration and retinoic acid synthesis.
Intertemporal Labor Supply and Human Capital Accumulation*
Authors: Imai Susumu , Keane Michael P.
Published: April 2004

We solve and estimate a dynamic model that allows agents to optimally choose their labor hours and consumption and that allows for both human capital accumulation and savings. Estimation results and simulation exercises indicate that the intertemporal elasticity of substitution is much higher than the conventional estimates and the downward bias comes from the omission of the human capital accumulation effect. The human capital accumulation effect renders the life‐cycle path of the shadow wage relatively flat, even though wages increase with age. Hence, a rather flat life‐cycle labor supply path can be reconciled with a high intertemporal elasticity of substitution.
Ultrasonic relaxation due to inclusion complex of amino acid by β-cyclodextrin in aqueous solution
Authors: Fukahori Takanori , Nishikawa Sadakatsu , Yamaguchi Kyohei
Published: April 2004

Ultrasonic absorption coefficients in the frequency range of 0.8–95 MHz were measured in aqueous solutions of L-methionine or L-norleucine (guest) in the presence and absence of β-cyclodextrin (β-CD, host) at 25 °C. A single relaxational absorption was observed only in the solutions containing the guest and host. The ultrasonic relaxation was attributed to a perturbation of a chemical equilibrium associated with an interaction between β-CD and the amino acid to form the host–guest complex. The kinetic and thermodynamic parameters in the system of L-norleucine with β-CD were determined from the concentration dependence of the relaxation frequency and the maximum absorption per wavelength. Because of the concentration independence of the relaxation frequency in L-methionine system with β-CD, the equilibrium constant and the standard volume change of the complexation reaction were estimated first from the concentration dependence of maximum absorption per wavelength, and subsequently the rate constants were calculated with the help of the estimated equilibrium constant and the observed relaxation frequency. The results obtained in this study were compared with those for systems of β-CD with other amino acids or alcohols having comparable hydrophobicity.
Monitoring of HIFU-induced lesions using active imaging methods
Authors: Yao Hui , Ebbini Emad
Published: April 2004

The use of active imaging methods in monitoring the properties of HIFU-induced lesions in freshly excised tissue is investigated. A modern ultrasound scanner is used to collect high-frame rate ultrasound images in conjunction with short-duration localized tissue modification using an external focused transducer. Two modes of reversible tissue modification are used: mechanically pushing the tissue using millisecond pulses and incrementally heating the tissue using 0.5–1 s duration pulses. Speckle tracking techniques are used to estimate the tissue displacements due to shear wave generation (in the case of ms pulse excitation) and temperature change (in the case of 1 s pulse excitation). Experimental results have shown that 20%– 25% change in the shear elastic modulus occurs after lesion formation and appears to be persistent up to 20 min after lesion formation. Absorption appears to increase significantly immediately after heating, but drops nearly to prelesion levels 5 min after heating. A description of the real-time ultrasonic monitoring system will be given. The principles of measurement of both thermal and viscoelastic properties are also described. Illustrative experimental examples from tissue data are given and discussed.
TOP QUARK MEASUREMENTS AT THE FERMILAB TEVATRON
Authors: AZZI P.
Published: April 2004

The top quark, discovered at the Tevatron in 1995, is a very interesting particle. Precise measurement of the top properties using large data samples will allow stringent tests of the Standard Model and offer a unique window on new physics. This report contains a review of the status of the current knowledge of the top quark as provided by the Run I results of the CDF and D0 experiments. A first look at various preliminary measurements obtained with data collected during Run II will also be presented.
THE TOP PRIORITY: PRECISION ELECTROWEAK PHYSICS FROM LOW TO HIGH ENERGY
Authors: GAMBINO P.
Published: April 2004

Overall, the Standard Model describes electroweak precision data rather well. There are however a few areas of tension (charged current universality, NuTeV, (g-2)μ, b quark asymmetries), which I review critically, emphasizing recent theoretical and experimental progress. I also summarize what precision data tell us about the Higgs boson and new physics scenarios. In this context, the role of a precise measurement of the top mass is crucial.
QCD: THEORETICAL DEVELOPMENTS
Authors: GEHRMANN T.
Published: April 2004

I review recent theoretical advances in quantum chromodynamics. Particular emphasis is put on developments related to the precise prediction and interpretation of experimental data from present and future high energy colliders.
EXPERIMENTAL LIMITS ON NEW PHYSICS FROM CHARM DECAY
Authors: YABSLEY B. D.
Published: April 2004

Recent measurements in the charm sector are reviewed, concentrating on results which are sensitive to New Physics effects. The scope of the presentation includes [Formula: see text] mixing searches, a CPT/Lorentz invariance study, and a range of searches for rare and forbidden decays. Results from the BaBar, Belle, CDF, CLEO, and FOCUS collaborations are presented, including an important first observation.
THE LARGE HADRON COLLIDER: A STATUS REPORT
Authors: MAIANI L.
Published: April 2004

The status of LHC construction, machine and detectors, is reviewed, with particular emphasis on the expected physics and on the industrial production of machine components.
ELECTRICAL AND OPTICAL NONLINEARITY IN VACUUM-DEPOSITED THIN FILMS OF POLY[N-(4-BENZOYLPHENYL)-2-METHYLACRYLAMIDE]
Authors: KALRA NEERAJ , CHAND FAKIR , MISHRA S. C. , VIJ D. R. , CHATURVEDI D. K. , KUMAR SUSHIL , ARORA SANJIV , MISRA S. C. K.
Published: April 2004

A new optically nonlinear material, poly[N-(4-benzoylphenyl)-2-methylacrylamide], for conversion of wavelength 1064 nm to 532 nm has been synthesized. The material possesses strong electrical and optical nonlinearity required for second harmonic generation (SHG). The thin films of poly[N-(4-benzoylphenyl)-2-methylacrylamide] were prepared by the vacuum-deposition technique. The optical UV-visible, IR, NMR studies, mass spectrometry, surface topography and nonlinear optical properties of the thin films were studied. The vacuum-deposited thin films of the polymer were subjected to optimized high potential multi-point corona poling at temperatures just below the glass transition temperature (Tg) to create directional orientation of the side chain groups. The optical UV-visible absorption indicates a complete transparency in the visible and IR regions with an absorption peak at ~350 nm. The energy band gap of the polymer was estimated to be ~2.9 eV, from the optical absorption spectra of the thin films. The electrical current–voltage (IV) and optical nonlinear characteristic indicate the strong potential of these polymeric thin films for nonlinear optical (NLO) applications.
FINESSE CONTROLLABLE ACTIVE RING-RESONATOR-COUPLED M-Z INTERFEROMETER OPTICAL SWITCHES
Authors: LI CHUNFEI , BANANEJ ALIREZA , LI JUNQING , XU GUANGMING
Published: April 2004

In order to get the lowest switching power in the ring-resonator-coupled M-Z interferometer switching devices, the loss in the ring resonator has to approach zero. However, in practice, the loss in the ring and coupler cannot be neglected, as it might make the switch unworkable. Therefore, we suggest inserting a gain-controllable optical amplifier into the ring to compensate for the losses and enhance the ring finesse to reduce the switching power. By adjusting the gain, a tradeoff between the switching power and the switching time can be obtained.
DYNAMIC TRAJECTORIES OF RELATIVISTIC ELECTRONS INJECTED INTO TIGHTLY-FOCUSED INTENSE LASER FIELDS
Authors: ZHANG S. Y. , HO Y. K. , CHEN Z. , XIE Y. J. , YAN Z. , XU J. J.
Published: April 2004

Dynamic trajectories of relativistic electrons injected into tightly focused ultra-intense laser field have been investigated. In addition to the previously-reported CAS (Capture and Acceleration Scenario) and IS (Inelastic Scattering) trajectories, a new kind of nonlinear electron trajectory is found when the beam waist radius w0 is small enough (kw0≤30, k is the wave number) and incident angle is small. We shall call it PARM (Penetrate into Axial Region and Move). The basic feature of PARM trajectory shows the strong diffraction effect of a tightly-focused laser field. Part of the incident electrons that experience the strong transversal force from the diffraction edge field as they travel toward the beam waist will follow the PARM trajectory. This force can push the electrons toward the beam center. Thus unlike the CAS and IS electrons, the PARM electrons will move along the region near the beam axis. We also found some of the PARM electrons can gain energy from the field. The conditions for PARM electrons to appear were examined and are presented here. The implication of the presence of PARM to the planned experimental test of the CAS scheme is addressed.
Thermally Stable Two‐Dimensional Hexagonal Mesoporous Nanocrystalline Anatase, Meso‐nc‐TiO2: Bulk and Crack‐Free Thin Film Morphologies
Authors: Choi S. Y. , Mamak M. , Coombs N. , Chopra N. , Ozin G. A.
Published: April 2004

Herein a novel synthetic route is described for the production of thermally stable, structurally well‐defined two‐dimensional (2D) hexagonal mesoporous nanocrystalline anatase (meso‐nc‐TiO2), with a large pore diameter, narrow pore‐size distribution, high surface area, and robust inorganic walls comprised of nanocrystalline anatase. The synthetic approach involves the evaporation‐induced co‐assembly of a non‐ionic amphiphilic triblock‐copolymer template and titanium tetraethoxide, but with a pivotal change in the main solvent of the system, where the commonly used ethanol is replaced with 1‐butanol. This seemingly minor modification in solvent type from ethanol to 1‐butanol turns out to be the key synthetic strategy for achieving a robust, structurally well‐ordered meso‐nc‐TiO2 material in the form of either thick or thin films. The beneficial “solvent” effect originates from the higher hydrophobicity of 1‐butanol than ethanol, enhancing microphase separation and templating, lower critical micelle concentration of the template in 1‐butanol, and the ability to increase the relative concentration of the inorganic precursor to template in the co‐assembly synthesis. Moreover, thin films with dimensions of several centimeters that are devoid of cracks down to the length scale of the mesostructure itself, having high porosity, well‐defined mesostructural features, and semi‐crystalline pore walls were straightforwardly and reproducibly obtained as a result of the physicochemical property advantages of 1‐butanol over ethanol within our synthesis scheme.
Optoelectronic Properties of Quasi‐Linear, Self‐Assembled Platinum Complexes: Pt–Pt Distance Dependence
Authors: Debije M. G. , de Haas M. P. , Warman J. M. , Fontana M. , Stutzmann N. , Kristiansen M. , Caseri W. R. , Smith P. , Hoffmann S. , Sølling T. I.
Published: April 2004

Charge‐carrier mobilities of various self‐assembled platinum complexes were measured by time‐resolved microwave conductivity techniques in the temperature range –80 to +100 °C. Eight compounds were investigated in the present study, including the original Magnus' green salt ([Pt(NH3)4][PtCl4]) and derivatives with the general structure [Pt(NH2R)4][PtCl4], where R denotes an alkyl side chain. In one instance, the chlorines were substituted with bromines. For these complexes, which all consist of a linear backbone of platinum atoms with Pt–Pt distances, d, varying from 3.1 to ≥ 3.6 Å, a strong, inverse correlation was found between d and the one‐dimensional charge‐carrier mobility, Σμ1D. The highest value of Σμ1D at room temperature was observed for R = (S)‐3,7‐dimethyloctyl (dmoc) with Σμ1D ≥ 0.06 cm2 V–1 s–1. Almost all materials exhibited a charge‐carrier mobility that was relatively independent of the temperature over the range studied. One exceptional compound (R = (R)‐2‐ethylhexyl) showed a pronounced negative temperature dependence of the charge‐carrier mobility; upon decreasing the temperature from +100 °C to –80 °C the charge‐carrier mobility increased by a factor of about ten.
Semiconducting Polymers via Microwave‐Assisted Suzuki and Stille Cross‐Coupling Reactions
Authors: Nehls B. S. , Asawapirom U. , Füldner S. , Preis E. , Farrell T. , Scherf U.
Published: April 2004

A fully conjugated para‐phenylene ladder polymer (P1) and the alternating copolymers {2,7‐[9,9‐bis(2‐ethylhexyl)fluorene]‐5,5′‐(2,2′‐bithiophene)} (P3) and {2,7‐[9,9‐dioctylfluorene]‐5,5′‐(2,2′‐bithiophene)} (P4) have been prepared via metal‐mediated cross‐coupling reactions, using microwaves as a heat source. The procedure, which yields polymeric material in ca. ten minutes, has no adverse effects on the quality of the polymers and displays a high degree of reproducibility. Transfer of the optimized conditions to the synthesis of a new naphthalene‐based polyarylene‐ketone (P2) and a (1,5‐dioctoxynaphthylene‐2,6‐diyl‐alt‐2,2′‐bithiophene‐5,5′‐diyl) copolymer (P5) confirmed the versatility of the procedure and the dramatic reduction in reaction times compared with conventional heating. In the case of the Stille‐type coupling reaction of the electron‐rich, less reactive dibromo monomer 1,5‐dioctoxy‐2,6‐dibromo‐naphthalene, the microwave‐assisted protocol results in a marked increase in both yield and molecular weight.
Light‐harvesting function of carotenoids in photo‐synthesis: The roles of the newly found 11B state
Authors: Koyama Yasushi , Rondonuwu Ferdy S. , Fujii Ritsuko , Watanabe Yasutaka
Published: April 2004

This minireview article highlights the energetics and the dynamics of the 11B and 31A states of carotenoids discovered very recently. Those “hidden” covalent states have been revealed by measurements of resonance‐Raman excitation profiles of crystalline carotenoids. The dependence of the energies of the low‐lying singlet states, including the 11B, 31A, 11B, and 21A states, on the number of conjugated double bonds (n) is in agreement with the extrapolation of those state energies calculated by Tavan and Schulten for shorter polyenes (P. Tavan and K. Schulten, Journal of Chemical Physics, 1986, vol. 85, pp. 6602–6609). It has also been shown that the internal‐conversion processes among those singlet states take place in accord with the state ordering, i.e., 11B → 11B → 21A → 11A (the ground state) for carotenoids having n = 9 and 10, whereas 11B → 31A → 11B → 21A → 11A for carotenoids having n = 11–13. Radiative transitions of 11B → 21A and 11B → 21A as well as a branching into the triplet manifold of 11B → 13Ag → 13Bu have also been found. Those low‐lying singlet states of all‐trans carotenoids can facilitate multiple channels of singlet‐energy transfer to bacteriochlorophyll in the LH2 antenna complexes of purple photosynthetic bacteria. Thus, the newly found 11B and 31A states of carotenoids need to be incorporated into the picture of carotenoid‐to‐bacteriochlorophyll singlet‐energy transfer. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Growth kinetics of zinc(tris)thiourea sulphate (ZTS) crystals
Authors: Arunmozhi G. , de M. Gomes E. , Ganesamoorthy S.
Published: April 2004

Growth kinetics of zinc (tris) thiourea sulphate (ZTS) crystals investigated as a function of supersaturation is reported in this communication. Crystal growth rates were investigated normal to the (100), (010) and (001) faces under growth conditions employed for bulk crystal growth. The growth rates normal to (010) and (100) were found to follow the continuous growth model (RG = Cσ) with respect to the supersaturation whereas the growth rates normal to (001) was found to satisfy birth and spread (B+S) model (RG = Aσ5/6 exp(‐B/σ)). The growth rates observed normal to the studied face are in agreement with the growth mechanism predicted from the estimated α (Jackson) factor. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Similarities between the quasi‐bubble and the generalized wave continuity equation solutions to the shallow water equations
Authors: Atkinson J. H. , Westerink J. J. , Hervouet J. M.
Published: April 2004

Two common strategies for solving the shallow water equations in the finite element community are the generalized wave continuity equation (GWCE) reformulation and the quasi‐bubble velocity approximation. The GWCE approach has been widely analysed in the literature. In this work, the quasi‐bubble equations are analysed and comparisons are made between the quasi‐bubble approximation of the primitive form of the shallow water equations and a linear finite element approximation of the GWCE reformulation of the shallow water equations. The discrete condensed quasi‐bubble continuity equation is shown to be identical to a discrete wave equation for a specific GWCE weighting parameter value. The discrete momentum equations are slightly different due to the bubble function. In addition, the dispersion relationships are shown to be almost identical and numerical experiments confirm that the two schemes compute almost identical results. Analysis of the quasi‐bubble formulation suggests a relationship that may guide selection of the optimal GWCE weighting parameter. Copyright © 2004 John Wiley & Sons, Ltd.
Two‐dimensional dispersion analyses of finite element approximations to the shallow water equations
Authors: Atkinson J. H. , Westerink J. J. , Luettich R. A.
Published: April 2004

Dispersion analysis of discrete solutions to the shallow water equations has been extensively used as a tool to define the relationships between frequency and wave number and to determine if an algorithm leads to a dual wave number response and near 2Δx oscillations. In this paper, we explore the application of two‐dimensional dispersion analysis to cluster based and Galerkin finite element‐based discretizations of the primitive shallow water equations and the generalized wave continuity equation (GWCE) reformulation of the harmonic shallow water equations on a number of grid configurations. It is demonstrated that for various algorithms and grid configurations, contradictions exist between the results of one‐dimensional and two‐dimensional dispersion analysis as a result of subtle changes in the mass matrix. Numerical experiments indicate that the two‐dimensional dispersion analysis correctly predicts the existence and onset of near 2Δx noise in the solution. Copyright © 2004 John Wiley & Sons, Ltd.
Journal entries and adjustments—your biggest fraud danger
Authors: DeVries Delwyn D. , Kiger Jack E.
Published: April 2004

False journal entries and other adjustments may be your biggest exposure to fraud. They figured prominently in some of the latest corporate scandals, including those at WorldCom, Cendant, and Xerox. What special actions must auditors take to keep your company safe from this kind of fraud? © 2004 Wiley Periodicals, Inc.
Evaluation of pork backfat firmness and lard consistency using several different physicochemical methods
Authors: Gläser Karola R , Wenk Caspar , Scheeder Martin RL
Published: April 2004

A total of 96 pigs were fed on a control diet (barley, wheat, soybean meal) or the control diet supplemented with one of six fats, differing in saturated (SFA), cis‐ and trans‐monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) content, in order to produce backfat widely differing in fatty acid composition. In addition to fatty acid composition, firmness was measured, by means of a puncture test, in the intact outer backfat layer and in lard extracted from the outer layer. Melting behaviour and solid fat content (SFC) were determined by differential scanning calorimetry and crystallisation time with a Rapid Interesterification Control‐Box. Regression analyses revealed that all consistency traits were mainly dependant on SFA content, particularly stearic acid. Cis‐MUFA were the next most decisive for crystallisation time and SFC. The prediction of firmness and SFC at 0 °C was improved when the proportion of PUFA was also considered. The stearic to linoleic acid ratio provided the best prediction of lard firmness. It was concluded that MUFA and PUFA exert specific effects on the different consistency characteristics and not only PUFA but also MUFA should be considered in feeding recommendations for growing‐finishing pigs when lard consistency is to be improved. Copyright © 2004 Society of Chemical Industry
A liquid chromatography‐mass spectrometric method for the determination of oak moss allergens atranol and chloroatranol in perfumes
Authors: Bossi Rossana , Rastogi Suresh C. , Bernard Guillaume , Gimenez‐Arnau Elena , Johansen Jeanne D. , Lepoittevin Jean‐Pierre , Menné Torkil
Published: April 2004

This paper describes a validated liquid chromatographic‐tandem mass spectrometric method for quantitative analysis of the potential oak moss allergens atranol and chloroatranol in perfumes and similar products. The method employs LC‐MS‐MS with electrospray ionization (ESI) in negative mode. The compounds are analysed by selective reaction monitoring (SRM) of 2 or 3 ions for each compound in order to obtain high selectivity and sensitivity. The method has been validated for the following parameters: linearity; repeatability; recovery; limit of detection; and limit of quantification. The limits of detection, 5.0 ng/mL and 2.4 ng/mL, respectively, for atranol and chloroatranol, achieved by this method allowed identification of these compounds at concentrations below those causing allergic skin reactions in oak‐moss‐sensitive patients. The recovery of chloratranol from spiked perfumes was 96±4%. Low recoveries (49±5%) were observed for atranol in spiked perfumes, indicating ion suppression caused by matrix components. The method has been applied to the analysis of 10 randomly selected perfumes and similar products.
Multicriteria e‐negotiation systems for e‐democracy
Authors: Insua David Rios , Holgado Julio , Moreno Raul
Published: April 2004

We outline concepts and an architecture underlying an electronic negotiation system. Once the participants' preferences are privately assessed, a variant of the balanced increment method is used to reach an agreement. The implications for such a system within e‐democracy are described. Copyright © 2004 John Wiley & Sons, Ltd.
Limit analysis for saturated porous media without fluid flow calculation
Authors: Corfdir Alain
Published: April 2004

Application of yield design to porous media usually requires a preliminary calculation of the fluid flow net. The stability analysis is then carried out with seepage forces associated with the flow. We assume here that the flow is steady and that the yield criterion is defined by a function of the effective stress tensor. The formulation that we propose here allows taking into account seepage force in the expression of the kinematic stability conditions by means of hydraulic boundary conditions without calculation of the fluid flow. One obtains a formulation of the kinematic condition similar to the case of classic, non‐porous media. The method is illustrated by two examples: a cylinder subjected to fluid flow and a vertical cut. It can be adapted to various boundary conditions and to the case of a criterion defined by a function of a generalized effective stress tensor. We also give a method to derive rigorous lower bounds using approximate fluid pressure field. Copyright © 2004 John Wiley & Sons, Ltd.
Uniform estimate of the constant in the strengthened CBS inequality for anisotropic non‐conforming FEM systems
Authors: Blaheta R. , Margenov S. , Neytcheva M.
Published: April 2004

Preconditioners based on various multilevel extensions of two‐level finite element methods (FEM) lead to iterative methods which have an optimal order computational complexity with respect to the size of the system. Such methods were first presented in Axelsson and Padiy (SIAM. J. Sci. Stat. Comp. 1990; 20:1807) and Axelsson and Vassilevski (Numer. Math. 1989; 56:157), and are based on (recursive) two‐level splittings of the finite element space. The key role in the derivation of optimal convergence rate estimates is played by the constant γ in the so‐called Cauchy–Bunyakowski–Schwarz (CBS) inequality, associated with the angle between the two subspaces of the splitting. It turns out that only existence of uniform estimates for this constant is not enough but accurate quantitative bounds for γ have to be found as well. More precisely, the value of the upper bound for γ∈(0,1) is part of the construction of various multilevel extensions of the related two‐level methods.

In this paper, an algebraic two‐level preconditioning algorithm for second‐order elliptic boundary value problems is constructed, where the discretization is done using Crouzeix–Raviart non‐conforming linear finite elements on triangles. An important point to make is that in this case the finite element spaces corresponding to two successive levels of mesh refinements are not nested. To handle this, a proper two‐level basis is considered, which enables us to fit the general framework for the construction of two‐level preconditioners for conforming finite elements and to generalize the method to the multilevel case.

The major contribution of this paper is the derived estimates of the related constant γ in the strengthened CBS inequality. These estimates are uniform with respect to both coefficient and mesh anisotropy. To our knowledge, the results presented in the paper are the first such estimates for non‐conforming FEM systems. Copyright © 2004 John Wiley & Sons, Ltd.
Existence of a low rank or ℋ︁‐matrix approximant to the solution of a Sylvester equation
Authors: Grasedyck L.
Published: April 2004

We consider the Sylvester equation AX−XB+C=0 where the matrix C∈ℂn×m is of low rank and the spectra of A∈ℂn×n and B∈ℂm×m are separated by a line. We prove that the singular values of the solution X decay exponentially, that means for any ε∈(0,1) there exists a matrix X̃ of rank k=O(log(1/ε)) such that ∥X−X̃∥2⩽ε∥X∥2. As a generalization we prove that if A,B,C are hierarchical matrices then the solution X can be approximated by the hierarchical matrix format described in Hackbusch (Computing 2000; 62: 89–108). The blockwise rank of the approximation is again proportional to log(1/ε). Copyright © 2004 John Wiley & Sons, Ltd.
Band structure effects in nitrogen K‐edge resonant inelastic X‐ray scattering from GaN
Authors: Strocov V. N. , Schmitt T. , Rubensson J.‐E. , Blaha P. , Paskova T. , Nilsson P. O.
Published: April 2004

Systematic experimental data on resonant inelastic X‐ray scattering (RIXS) in GaN near the N K‐edge are presented for the first time. Excitation energy dependence of the spectral structures manifests the band structure effects originating from momentum selectivity of the RIXS process. This finding allows obtaining k‐resolved band structure information for GaN crystals and nanostructures. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New Operative Method for Fundal Variceal Bleeding: Fundectomy with Periesophagogastric Devascularization
Authors: Han Ho‐Seong , Yi Nam‐Joon , Kim Young‐Woo , Fleischer Gary D.
Published: April 2004

Cirrhotic patients with gastric fundal bleeding occasionally require operative intervention. Fundal variceal bleeding may be controlled by performing a fundectomy in addition to periesophagogastric devascularization. For 23 patients with cirrhosis, preoperative nonsurgical intervention alone could not achieve definitive control of variceal bleeding from the gastric fundus, and periesophagogastric devascularization with the fundectomy—specifically resection of the varix‐bearing lesion in the fundus—was performed. Direct inspection and palpation determined the area for the fundectomy, and resection was limited to the engorged varix‐bearing area. The overall mortality rate was 26.1%. There were two postoperative deaths (18.2%) among 11 patients in the elective operation group and four deaths (33.3%) among 12 patients in the emergency operation group (p > 0.05). The mortality rates among class A, B, and C patients, following the Child‐Pugh classification for hepatic functional reserve, were 0% (0/4), 23.1% (3/13), and 50.0% (3/6), respectively (p > 0.05). The patients who died had been transfused preoperatively with a mean of 13.0 ± 10.5 units, and those who survived received a mean of 6.00 ± 5.96 units (p > 0.05). Patients who were successfully stabilized by preoperative endoscopic intervention had significantly lower mortality (p < 0.001). During follow‐up there was no recurrent bleeding from gastric varices, and there was only one case (4.35%) of hemorrhage from esophageal varices. Hence, periesophagogastric devascularization and fundectomy offers an alternative operative method for cirrhotic patients with variceal hemorrhaging from the gastric fundus.
Semiclassical calculations of collision line broadening in Raman spectra of N2 and CO mixtures
Authors: Afzelius Mikael , Bengtsson Per-Erik , Bonamy Jeanine
Published: April 2004

We present a detailed theoretical study of pressure-broadened Raman line shapes in binary mixtures of nitrogen and carbon monoxide. The semiclassical Robert–Bonamy theory was used to calculate self-broadened Q-branch linewidths of N2 and CO, and Lennard-Jones (LJ) potential energy surface parameters were fixed by comparing our results with extensive experimental linewidth data. For the case of N2, the ab initio PES8 potential energy surface was investigated, however, the anisotropic repulsive part had to be reduced to ensure a good agreement with experimental linewidths. The agreement between calculations and experiments was remarkably good, both for self-broadened N2 and CO Q-branch linewidths. Yet, our calculations were not able to predict the experimentally observed difference between Q- and S-branch linewidths of self-broadened N2. The central results of this work are the Q-branch linewidths of N2–CO and CO–N2, which have been calculated through an extrapolation of the parameters of the potential energy surfaces used for self-broadened linewidths by common combination rules.
Correlated ab initio calculations of spectroscopic parameters of SnO within the framework of the higher-order generalized Douglas–Kroll transformation
Authors: Wolf Alexander , Reiher Markus , Hess Bernd Artur
Published: April 2004

The first molecular calculations with the generalized Douglas–Kroll method up to fifth order in the external potential (DKH5) are presented. We study the spectroscopic parameters and electron affinity of the tin oxide molecule SnO and its anion SnO− applying nonrelativistic as well as relativistic calculations with higher orders of the DK approximation. In order to guarantee highly accurate results close to the basis set limit, an all-electron basis for Sn of at least quintuple-ζ quality has been constructed and optimized. All-electron CCSD(T) calculations of the potential energy curves of both SnO and SnO− reproduce the experimental values very well. Relative energies and valence properties are already well described with the established standard second-order approximation DKH2 and the higher-order corrections DKH3–DKH5 hardly affect these quantities. However, an accurate description of total energies and inner-shell properties requires superior relativistic schemes up to DKH5.
Static and dynamic properties of tethered chains at adsorbing surfaces: A Monte Carlo study
Authors: Descas Radu , Sommer Jens-Uwe , Blumen Alexander
Published: April 2004

We present extensive Monte Carlo simulations of tethered chains of length N on adsorbing surfaces, considering the dilute case in good solvents, and analyze our results using scaling arguments. We focus on the mean number M of chain contacts with the adsorbing wall, on the chain’s extension (the radius of gyration) perpendicular and parallel to the adsorbing surface, on the probability distribution of the free end and on the density profile for all monomers. At the critical adsorption strength εc one has Mc∼Nφ, and we find (using the above results) as best candidate φ to equal 0.59. However, slight changes in the estimation of εc lead to large deviations in the resulting φ; this might be a possible reason for the difference in the φ values reported in the literature. We also investigate the dynamical scaling behavior at εc, by focusing on the end-to-end correlation function and on the correlation function of monomers adsorbed at the wall. We find that at εc the dynamic scaling exponent a (which describes the relaxation time of the chain as a function of N) is the same as that of free chains. Furthermore, we find that for tethered chains the modes perpendicular to the surface relax quicker than those parallel to it, which may be seen as a splitting in the relaxation spectrum.
Surface tension of quantum fluids from molecular simulations
Authors: Zhao Xiongce , Johnson J. Karl , Rasmussen Craig E.
Published: April 2004

We present the first molecular simulations of the vapor–liquid surface tension of quantum liquids. The path integral formalism of Feynman was used to account for the quantum mechanical behavior of both the liquid and the vapor. A replica-data parallel algorithm was implemented to achieve good parallel performance of the simulation code on at least 32 processors. We have computed the surface tension and the vapor–liquid phase diagram of pure hydrogen over the temperature range 18–30 K and pure deuterium from 19 to 34 K. The simulation results for surface tension and vapor–liquid orthobaric densities are in very good agreement with experimental data. We have computed the interfacial properties of hydrogen–deuterium mixtures over the entire concentration range at 20.4 and 24 K. The calculated equilibrium compositions of the mixtures are in excellent agreement with experimental data. The computed mixture surface tension shows negative deviations from ideal solution behavior, in agreement with experimental data and predictions from Prigogine’s theory. The magnitude of the deviations at 20.4 K are substantially larger from simulations and from theory than from experiments. We conclude that the experimentally measured mixture surface tension values are systematically too high. Analysis of the concentration profiles in the interfacial region shows that the nonideal behavior can be described entirely by segregation of H2 to the interface, indicating that H2 acts as a surfactant in H2–D2 mixtures.
Contact area between a viscoelastic solid and a hard, randomly rough, substrate
Authors: Persson B. N. J. , Albohr O. , Creton C. , Peveri V.
Published: April 2004

We study the time-dependent contact area as a viscoelastic solid is squeezed against a randomly rough substrate. Using a recently developed contact mechanics theory we study how the contact area depends on time and on the magnification ζ. Numerical results are presented for self-affine fractal surfaces, and applications to tack, rubber friction, and sealing are given.
PML–RARA-RXR Oligomers Mediate Retinoid and Rexinoid/cAMP Cross-Talk in Acute Promyelocytic Leukemia Cell Differentiation
Authors: Kamashev Dmitrii , Vitoux Dominique , de Thé Hugues
Published: April 2004

PML–RARA was proposed to initiate acute promyelocytic leukemia (APL) through PML–RARA homodimer–triggered repression. Here, we examined the nature of the PML–RARA protein complex and of its DNA targets in APL cells. Using a selection/amplification approach, we demonstrate that PML–RARA targets consist of two AGGTCA elements in an astonishing variety of orientations and spacings, pointing to highly relaxed structural constrains for DNA binding and identifying a major gain of function of this oncogene. PML–RARA-specific response elements were identified, which all conveyed a major transcriptional response to RA only in APL cells. In these cells, we demonstrate that PML–RARA oligomers are complexed to RXR. Directly probing PML–RARA function in APL cells, we found that the differentiation enhancer cyclic AMP (cAMP) boosted transcriptional activation by RA. cAMP also reversed the normal silencing (subordination) of the transactivating function of RXR when bound to RARA or PML–RARA, demonstrating that the alternate rexinoid/cAMP-triggered APL differentiation pathway also activates PML–RARA targets. Finally, cAMP restored both RA-triggered differentiation and PML–RARA transcriptional activation in mutant RA-resistant APL cells. Collectively, our findings directly demonstrate that APL cell differentiation parallels transcriptional activation through PML–RARA-RXR oligomers and that those are functionally targeted by cAMP, identifying this agent as another oncogene-targeted therapy.
Sleep Problems in Early Childhood and Early Onset of Alcohol and Other Drug Use in Adolescence
Authors: Wong Maria M. , Brower Kirk J. , Fitzgerald Hiram E. , Zucker Robert A.
Published: April 2004

Abstract: Background: No prospective studies exist on the relationship between sleep problems early in life and subsequent alcohol use. Stimulated by the adult literature linking sleep problems to the subsequent onset of alcohol use disorders in some adults, we examined whether sleep problems in early childhood predicted the onset of alcohol and other drug use in adolescence and whether such a relationship was mediated by other known predictors of this relationship, namely, attention problems, anxiety/depression, and aggression in late childhood.

Methods: This study is part of an ongoing longitudinal study of the development of risk for alcohol and other substance use disorders. Study participants were 257 boys from a community‐recruited sample of high‐risk families.

Results: Mothers’ ratings of their children's sleep problems at ages 3 to 5 years significantly predicted an early onset of any use of alcohol, marijuana, and illicit drugs, as well as an early onset of occasional or regular use of cigarettes by age 12 to 14. Additionally, although sleep problems in early childhood also predicted attention problems and anxiety/depression in later childhood, these problems did not mediate the relationship between sleep problems and onset of alcohol and other drug use.

Conclusions: This is, to our knowledge, the first study that prospectively examines the relationship between sleep problems and early onset of alcohol use, a marker of increased risk for later alcohol problems and alcohol use disorders. Moreover, early childhood sleep problems seem to be a robust marker for use of drugs other than alcohol. Implications for the prevention of early alcohol and other drug use are discussed.
Conservation of the opcL gene encoding the peptidoglycan-associated outer-membrane lipoprotein among representatives of the Burkholderia cepacia complex
Authors: Plesa Maria , Kholti Abdelaziz , Vermis Karen , Vandamme Peter , Panagea Stavroula , Winstanley Craig , Cornelis Pierre
Published: April 2004

Members of the Burkholderia cepacia complex are Gram-negative β-proteobacteria that are classified into nine genomic species or genomovars. Some representatives of this group of bacteria, such as Burkholderia multivorans (genomovar II) and Burkholderia cenocepacia (genomovar III), are considered to be dangerous pathogens for cystic fibrosis (CF) patients because of their capacity to colonize CF lungs. The opcL gene, which encodes the peptidoglycan-associated outer-membrane lipoprotein (PAL), was detected in the genome of Burkholderia sp. LB 400 by a similarity search that was based on the sequence of the Pseudomonas aeruginosa PAL, OprL. Primers that could amplify part of opcL from B. multivorans LMG 13010T were designed. This PCR fragment was used as a probe for screening of a B. multivorans genomic bank, allowing cloning of the complete opcL gene. The complete opcL gene could be PCR-amplified from DNA from all genomovars. The sequences of these opcL genes showed a high degree of conservation (> 95 %) among different species of the B. cepacia complex. OpcL protein that was purified from B. multivorans LMG 13010T was used to generate mouse polyclonal antisera against OpcL. The OpcL protein could be produced in Escherichia coli and detected in outer-membrane fractions by Western blot. Burkholderia cells were labelled by immunofluorescence staining using antibodies against OpcL, but only after treatment with EDTA and SDS. The opcL gene could be amplified directly from the sputa of 15 CF patients who were known to be colonized by B. cepacia; sequence data derived from the amplicons identified the colonizing strains as B. cenocepacia (genomovar III, n = 14) and B. multivorans (n = 1).
Antibody response and viraemia during the course of severe acute respiratory syndrome (SARS)-associated coronavirus infection
Authors: Chen Weijun , Xu Zuyuan , Mu Jingsong , Yang Ling , Gan Haixue , Mu Feng , Fan Baoxing , He Bo , Huang Shengyong , You Bo , Yang Yongkui , Tang Xiangjun , Qiu Ling , Qiu Yan , Wen Jie , Fang Jianqiu , Wang Jian
Published: April 2004

To understand the time-course of viraemia and antibody responses to severe acute respiratory syndrome-associated coronavirus (SARS-CoV), RT-PCR and ELISA were used to assay 376 blood samples from 135 SARS patients at various stages of the illness, including samples from patients who were in their early convalescent phase. The results showed that IgM antibodies decreased and became undetectable 11 weeks into the recovery phase. IgG antibodies, however, remained detectable for a period beyond 11 weeks and were found in 100 % of patients in the early convalescent phase. SARS-CoV viraemia mainly appeared 1 week after the onset of illness and then decreased over a period of 1 month, becoming undetectable in the blood samples of the convalescent patients. At the peak of viraemia, viral RNA was detectable in 75 % of blood samples from patients who were clinically diagnosed with SARS 1 or 2 weeks before the test.