bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental study of turbulent swirling flow in a straight pipe
Authors: Kitoh Osami
Published: April 2006

Swirling flow through a pipe is a highly complex turbulent flow and is still challenging to predict. An experimental investigation is performed to obtain systematic data about the flow and to understand its physics. A free-vortex-type swirling flow is introduced in a long straight circular pipe. The swirling component decays downstream as a result of wall friction. The velocity distributions are continuously changing as they approach fully developed parallel flow. The swirl intensity Ω, defined as a non-dimensional angular momentum flux, decays exponentially. The decay coefficients, however, are not constant as conventionally assumed, but depend on the swirl intensity. The wall shear stresses are measured by a direct method and, except in a short inlet region, are a function only of the swirl intensity and the Reynolds number. The velocity distributions and all Reynolds stress components are measured at various axial positions in the pipe. The structure of the tangential velocity profile is classified into three regions: core, annular and wall regions. The core region is characterized by a forced vortex motion and the flow is dependent upon the upstream conditions. In the annular region, the skewness of the velocity vector is noticeable and highly anisotropic so that the turbulent viscosity model does not work well here. The tangential velocity is expressed as a sum of free and forced vortex motion. In the wall region the skewness of the flow becomes weak, and the wall law modified by the Monin–Oboukhov formula is applicable. Data on the microscale and the spectrum are also presented and show quite different turbulence structures in the core and the outer regions.
Particle dispersion in isotropic turbulence under Stokes drag and Basset force with gravitational settling
Authors: Mei Renwei , Adrian Ronald J. , Hanratty Thomas J.
Published: April 2006

An analysis that includes the effects of Basset and gravitational forces is presented for the dispersion of particles experiencing Stokes drag in isotropic turbulence. The fluid velocity correlation function evaluated on the particle trajectory is obtained by using the independence approximation and the assumption of Gaussian velocity distributions for both the fluid and the particle, formulated by Pismen & Nir (1978). The dynamic equation for particle motion with the Basset force is Fourier transformed to the frequency domain where it can be solved exactly. It is found that the Basset force has virtually no influence on the structure of the fluid velocity fluctuations seen by the particles or on particle diffusivities. It does, however, affect the motion of the particle by increasing (reducing) the intensities of particle turbulence for particles with larger (smaller) inertia. The crossing of trajectories associated with the gravitational force tends to enhance the effect of the Basset force on the particle turbulence. An ordering of the terms in the particle equation of motion shows that the solution is valid for high particle/fluid density ratios and to 0(1) in the Stokes number.
Secondary frequencies in the wake of a circular cylinder with vortex shedding
Authors: Abarbanel Saul S. , Don Wai Sun , Gottlieb David , Rudy David H. , Townsend James C.
Published: April 2006

A detailed numerical study of two-dimensional flow past a circular cylinder at moderately low Reynolds numbers has been conducted using three different numerical algorithms for solving the time-dependent compressible Navier–Stokes equations. It was found that if the algorithm and associated boundary conditions were consistent and stable, then the major features of the unsteady wake were well predicted. However, it was also found that even stable and consistent boundary conditions could introduce additional periodic phenomena reminiscent of the type seen in previous wind-tunnel experiments. However, these additional frequencies were eliminated by formulating the boundary conditions in terms of the characteristic variables. An analysis based on a simplified model provides an explanation for this behaviour.
Measurements of particle dispersion obtained from direct numerical simulations of isotropic turbulence
Authors: Squires Kyle D. , Eaton John K.
Published: April 2006

Measurements of heavy particle dispersion have been made using direct numerical simulations of isotropic turbulence. The parameters affecting the dispersion of solid particles, namely particle inertia and drift due to body forces were investigated separately. In agreement with the theoretical studies of Reeks, and Pismen & Nir, the effect of particle inertia is to increase the eddy diffusivity over that of the fluid (in the absence of particle drift). The increase in the eddy diffusivity of particles over that of the fluid was between 2 and 16%, in reasonable agreement with the increases reported in Reeks, and Pismen & Nir. The effect of a deterministic particle drift is shown to decrease unequally the dispersion in directions normal and parallel to the particle drift direction. Eddy diffusivities normal and parallel to particle drift are shown to be in good agreement with the predictions of Csanady and the experimental measurements of Wells & Stock.
Potential flow solution for a yawed surface-piercing plate
Authors: Xü Hongbo
Published: April 2006

This paper presents the results of an analytical investigation of the steady translation of a vertical surface-piercing plate at a small angle of attack. This problem is the antisymmetric equivalent of the symmetric thin-ship problem solved by Michell. The linearized boundary-value problem is transformed into an integral equation of the first kind by the method of Green functions. The Kelvin–Havelock Green function is used to satisfy the linearized free-surface boundary condition and radiation condition. A pressure Kutta condition is imposed at the trailing edge. Effective algorithms are developed to evaluate the hypersingular kernel without recourse to numerical integration. The resulting integral equation is solved by a collocation method with a refined scheme of discretization. After establishing the convergence of the present algorithm, computations are carried out for a surface-piercing rectangular plate of aspect ratio 0.5. The integrated lateral-force and yaw-moment coefficients show good agreement with experimental data. Other parameters of the flow such as pressure distributions, drag, strength of leading-edge singularity and free-surface profiles on the plate are also presented. The incompatibility between the pressure Kutta condition and the linearized free-surface condition does not affect the global solution.
Asymptotic evaluation of three-dimensional wave packets in parallel flows
Authors: Jiang Feng
Published: April 2006

This paper examines the three-dimensional wave packets which are generated by an initially localized pulse disturbance in an incompressible parallel flow and described by a double Fourier integral in the wavenumber space. It aims to clear up some confusion arising from the asymptotic evaluation of this integral by the method of steepest descent. In this asymptotic analysis, the calculation of the eigenvalues can be facilitated by making use of the Squire transformation. It is demonstrated that the use of the Squire transformation introduces branch points in the saddle-point equation that links the physical coordinates to the saddle-point value, regardless of whether the flow is viscous or inviscid. It is shown that the correct branch should be chosen according to the principle of analytic continuation. The saddle-point values for the three-dimensional problem should be considered to be the analytic continuation of those for the two-dimensional case where the saddle-point values can be uniquely determined. The three-dimensional wave packets in an inviscid wake flow are examined; their behaviour at large time is calculated asymptotically by the method of steepest descent in terms of the two-dimensional eigenvalue relation.
Oscillatory flow and mass transport in a flexible tube
Authors: Dragon Carolyn A. , Grotberg James B.
Published: April 2006

The mass transport of a diffusible substance during volume-cycled oscillatory flow in a thin-walled viscoelastic tube is studied. A small-amplitude, long-wavelength travelling wave is generated by the oscillatory pressure gradient. Lubrication theory is employed for slow axial variations to derive regular perturbation solutions to the Navier–Stokes equations. The convection–diffusion equation is solved in a similar manner, assuming uniform steady end concentrations and no wall flux. From the velocity and concentration fields, the time-average rate of axial mass transport is calculated, and its dependence on oscillation frequency, tube stiffness, and stroke amplitude is investigated. The general result is that transport is enhanced less for softer tubes than for stiffer ones and that mass flow rate as a function of frequency reaches a local maximal value. The results are related to gas transport in pulmonary airways during high-frequency ventilation.
Coastal Kelvin waves in the presence of a slowly varying topography
Authors: Chang Ping
Published: April 2006

The evolution equation is derived for a weakly nonlinear coastal Kelvin wave propagating in slowly varying topography in anf-plane ocean. For weak transverse variations in the topography, the wave evolution is governed by a perturbed Korteweg–de Vries equation. In the absence of transverse variation, wave dispersion vanishes and the evolution equation reduces to a nonlinear advection equation with variable coefficients. As a general property of these equations, the total mass flux associated with the Kelvin wave is not conserved; residual mass must be generated. It is shown by an asymptotic analysis that this residual mass field is in balance with a mean geostrophic current long after the passage of the Kelvin wave. This result is verified using a numerical model. The physical mechanism evolved in the generation of the residual mass can be understood in terms of potential vorticity conservation.
Mass transport in three-dimensional water waves
Authors: Iskandarani Mohamed , Liu Philip L.-F.
Published: April 2006

A spectral scheme is developed to study the mass transport in three-dimensional water waves where the steady flow is assumed to be periodic in two horizontal directions. The velocity–vorticity formulation is adopted for the numerical solution, and boundary conditions for the vorticity are derived to enforce the no-slip conditions. The numerical scheme is used to calculate the mass transport under two intersecting wave trains; the resulting flow is reminiscent of the Langmuir circulation patterns. The scheme is then applied to study the steady flow in a three-dimensional standing wave.
Optical studies on the turbulent motion of solid particles in a pipe flow
Authors: Young James B. , Hanratty Thomas J.
Published: April 2006

An extension of an axial viewing optical technique (first used by Lee, Adrian & Hanratty) is described which allows the determination of the turbulence characteristics of solid particles being transported by water in a pipe. Measurements are presented of the mean radial velocity, the mean rate of change radial velocity, the mean-square of the radial and circumferential fluctuations, the Eulerian turbulent diffusion coefficient, and the Lagrangian turbulent diffusion coefficient. A particular focus is to explore the influence of slip velocity for particles which have small time constants. It is found that with increasing slip velocity the magnitude of the turbulent velocity fluctuations remains unchanged but that the turbulent diffusivity decreases. The measurements of the average rate of change of particle velocity are consistent with the notion that particles move from regions of high fluid turbulence to regions of low fluid turbulence. Measurements of the root-mean-square of the fluctuations of the rate of change of particle velocity allow an estimation of the average magnitude of the particle slip in a highly turbulent flow, which needs to be known to analyse the motion of particles not experiencing a Stokes drag.
New Labour's Partnerships: Comparing Conceptual Models with Existing Forms
Authors: Powell Martin , Dowling Bernard
Published: April 2006

The establishment of partnerships has been a central feature of British social welfare policy since 1997 when the New Labour government came to power. Although the academic attention given to partnership working since then has grown considerably, there have been few attempts to link conceptual models of partnerships with existing forms. This paper addresses this gap and finds that, while there are links between actual and model partnerships, there is little evidence that actual partnerships have been designed or structured to meet their particular tasks.
Interaction energies of monosubstituted benzene dimers via nonlocal density functional theory
Authors: Thonhauser T. , Puzder Aaron , Langreth David C.
Published: April 2006

We present density functional calculations for the interaction energy of monosubstituted benzene dimers. Our approach utilizes a recently developed fully nonlocal correlation energy functional, which has been applied to the pure benzene dimer and several other systems with promising results. The interaction energy as a function of monomer distance was calculated for four different substituents in a sandwich and two T-shaped configurations. In addition, we considered two methods for dealing with exchange, namely, using the revPBE generalized gradient functional as well as full Hartree-Fock. Our results are compared with other methods, such as Møller-Plesset and coupled-cluster calculations, thereby suggesting the usefulness of our approach. Since our density functional based method is considerably faster than other standard methods, it provides a computationally inexpensive alternative, which is of particular interest for larger systems where standard calculations are too expensive or infeasible.
Second order superintegrable systems in conformally flat spaces. IV. The classical 3D Stäckel transform and 3D classification theory
Authors: Kalnins E. G. , Kress J. M. , Miller W.
Published: April 2006

This article is one of a series that lays the groundwork for a structure and classification theory of second order superintegrable systems, both classical and quantum, in conformally flat spaces. In the first part of the article we study the Stäckel transform (or coupling constant metamorphosis) as an invertible mapping between classical superintegrable systems on different three-dimensional spaces. We show first that all superintegrable systems with nondegenerate potentials are multiseparable and then that each such system on any conformally flat space is Stäckel equivalent to a system on a constant curvature space. In the second part of the article we classify all the superintegrable systems that admit separation in generic coordinates. We find that there are eight families of these systems.
Nonplanar dust acoustic waves with transverse perturbation in dusty plasmas with variable dust charge and negative ions
Authors: Wang Yue-yue , Zhang Jie-fang
Published: April 2006

A cylindrical Kadomstev-Petviashvili equation is derived in cylindrical geometry for dust acoustic waves in dusty plasmas consisting of positive ions, negative ions, and adiabatic variable charged dust grains. The effects of negative ions on the dust charge number and dust temperature, as well as the solitonic structures, such as the Nebulon and W-shape soliton, etc., have been investigated. It has also been found that the effect of transverse perturbations is the main factor that determines the formation of the Nebulon.
Amylase‐Resistant Starch as Adjunct to Oral Rehydration Therapy in Children with Diarrhea
Authors: Raghupathy P. , Ramakrishna B. S. , Oommen Samuel P. , Ahmed Mir Shovkat , Priyaa G. , Dziura James , Young Graeme P. , Binder Henry J.
Published: April 2006

Background:

Oral rehydration solution (ORS) for treatment of diarrhea relies on enhancement of small intestinal sodium and fluid absorption to correct dehydration. Amylase‐resistant starch added to ORS significantly reduced the duration and severity of diarrhea in adults with cholera, presumably by generation of short‐chain fatty acids in the colon and enhancement of colonic sodium and fluid absorption. The present study was initiated to determine whether addition of amylase‐resistant starch to standard World Health Organization glucose‐ORS (G‐ORS) would reduce the duration of diarrhea and fecal fluid losses in children with acute diarrhea.

Methods:

One hundred eighty‐three children (6 months to 3 years) with acute watery diarrhea were randomized to receive either standard treatment with G‐ORS or G‐ORS with additional amylase‐resistant starch, HAMS (HAMS‐ORS, 50g/L). Stool weight and consistency were monitored serially until development of formed stool or development of treatment failure defined as either the need for unscheduled intravenous fluid therapy or diarrhea longer than 72 hours.

Results:

Five of the subjects were lost to follow up. In 178 remaining children (87 HAMS‐ORS and 91 G‐ORS) with evaluable data, time from enrolment to last unformed stool was significantly less in children receiving HAMS‐ORS (median, 6.75 hours; 95% confidence interval, 4.27‐9.22) than in children treated with G‐ORS (12.80 hours, 8.69‐16.91) (P = 0.0292). Time to first formed stool was also significantly shorter in children receiving HAMS‐ORS (median, 18.25 hours; 95% confidence interval, 13.09‐23.41) compared with children receiving G‐ORS (median, 21.50 hours; 95% confidence interval, 17.26‐25.74) (P = 0.0440). The total amount of ORS consumed was similar in both groups. There was a trend toward lower mean stool weight in first 24 hours (P = 0.0752) as well as total diarrheal stool weight (P = 0.0926) in patients in the HAMS group compared with the G‐ORS group.

Conclusion:

In children with acute diarrhea, the addition of amylase‐resistant starch to glucose ORS significantly shortened duration of diarrhea compared with standard treatment.
Raised intracranial pressure in a neonate presenting as stridor
Authors: SOLAN KATE , GLAISYER HILARY
Published: April 2006

Neonatal stridor is an important sign of upper airway obstruction. This is most commonly secondary to laryngeal pathology and investigated by otolaryngologists. However neurological causes of stridor, secondary to vocal cord paralysis also occur for a variety of reasons (1). In cases of meningomyelocele up to 20% of infants may develop stridor (2). Respiratory distress may be severe and require prompt surgical and medical intervention. We describe a neonate born with a meningomyelocele, who developed stridor secondary to evolving hydrocephalus after surgical repair of the meningomyelocele. This was treated acutely by direct tapping of cerebrospinal fluid from the right coronal horn via the coronal suture with immediate symptomatic improvement prior to a definitive shunt procedure.
An experimental approach to simulate transgene pyramiding for the deployment of cry genes to control potato tuber moth (Phthorimaea operculella)
Authors: Meiyalaghan S. , Butler R.C. , Wratten S.D. , Conner A.J.
Published: April 2006

Alternating the daily feeding of potato tuber moth (Phthorimaea operculella) larvae (PTM) between isogenic pairs of potato plants provides an effective experimental approach to simulate transgene pyramiding in a clonal crop. This involves an experimental design with all six possible pairwise combinations of two transgenic lines expressing different cry genes and the non‐transgenic control. In this manner, we have simulated the pyramiding of pairwise combinations of cry1Ac9, cry9Aa2 and cry1Ba1 genes in potato and evaluated how pairs of these three cry genes interact to influence the growth rate of PTM larvae. The results show that all combinations of the three cry genes were largely consistent with additive impacts on PTM larval growth, although results from the combination of the cry1Ac9 and cry9Aa2 genes were suggestive of slight synergistic effects. Pyramiding the cry1Ac9, cry9Aa2 and cry1Ba1 genes in potato could therefore provide a more effective strategy to control PTM compared to single cry gene transgenic plants.
Pharmacodynamics of Levofloxacin against
Pseudomonas aeruginosa
with Reduced Susceptibility Due to Different Efflux Pumps: Do Elevated MICs Always Predict Reduced In Vivo Efficacy?
Authors: Griffith David C. , Corcoran Erik , Lofland Denene , Lee Angela , Cho Deidre , Lomovskaya Olga , Dudley Michael N.
Published: April 2006

The
Pseudomonas aeruginosa
efflux pumps MexAB-OprM, MexCD-OprJ, and MexEF-OprN play an important role in susceptibility to fluoroquinolones in vitro. To determine if levofloxacin MICs arising from different levels of expression of efflux pumps result in a proportional reduction in the response to levofloxacin in vivo, isogenic strains of
P. aeruginosa
were tested with levofloxacin in two mouse models of infection (sepsis and neutropenic mouse thigh models). The levofloxacin 50% effective doses (ED
50
s) increased proportionally with the MICs for most strains. Similarly, the 24-h area under the concentration-time curve (AUC)/MIC ratio that resulted in 90% of the maximum bactericidal activity (90%
E
max
) exceeded 75 for all strains except those with elevated MICs due to MexEF-OprN overexpression. In these strains, levofloxacin ED
50
s were 2- to 10-fold lower than the ED
50
/MIC ratios in the other strains and 90%
E
max
AUC/MIC ratios were 2- to 4-fold lower than those predicted from pharmacodynamic modeling of efficacy against other strains. These data show that while the MexEF-OprN efflux pump can provide
P. aeruginosa
resistance to levofloxacin in vitro, it appears to be less efficient in providing resistance to levofloxacin in animal models of infection.
7-
O
-Malonyl Macrolactin A, a New Macrolactin Antibiotic from
Bacillus subtilis
Active against Methicillin-Resistant
Staphylococcus aureus
, Vancomycin-Resistant Enterococci, and a Small-Colony Variant of
Burkholderia cepacia
Authors: Romero-Tabarez Magally , Jansen Rolf , Sylla Marita , Lünsdorf Heinrich , Häußler Susanne , Santosa Dwi A. , Timmis Kenneth N. , Molinari Gabriella
Published: April 2006

We report here the discovery, isolation, and chemical and preliminary biological characterization of a new antibiotic compound, 7-
O
-malonyl macrolactin A (MMA), produced by a
Bacillus subtilis
soil isolate. MMA is a bacteriostatic antibiotic that inhibits a number of multidrug-resistant gram-positive bacterial pathogens, including methicillin-resistant
Staphylococcus aureus
, vancomycin-resistant enterococci, and a small-colony variant of
Burkholderia cepacia
. MMA-treated staphylococci and enterococci were pseudomulticellular and exhibited multiple asymmetric initiation points of septum formation, indicating that MMA may inhibit a cell division function.
A Tryptophan-Rich Motif in the Carboxyl Terminus of the Small Envelope Protein of Hepatitis B Virus Is Central to the Assembly of Hepatitis Delta Virus Particles
Authors: Komla-Soukha Isabelle , Sureau Camille
Published: April 2006

The small hepatitis B virus surface antigen (S-HBsAg) is capable of driving the assembly and secretion of hepatitis delta virus (HDV) particles by interacting with the HDV ribonucleoprotein (RNP). Previously, a specific domain of the S-HBsAg protein carboxyl terminus, including a tryptophan residue at position 196 (W196), was proven essential for HDV maturation (S. Jenna and C. Sureau, J. Virol. 73: 3351-3358, 1999). Mutation of W196 to phenylalanine (W196F) was permissive for HBV subviral particle (SVP) secretion but deleterious to HDV virion assembly. Here, the W196F S-HBsAg deficiency was assigned to a loss of its ability for interaction with the large HDV antigen (L-HDAg), a major component of the RNP. Because the overall S-HBsAg carboxyl terminus is particularly rich in tryptophan, an amino acid frequently involved in protein-protein interactions, site-directed mutagenesis was conducted to investigate the function of the S-HBsAg Trp-rich domain in HDV assembly. Single substitutions of tryptophan between positions 163 and 201 with alanine or phenylalanine were tolerated for SVP secretion, but those affecting W196, W199, and W201 were detrimental for HDV assembly. This was proven to result from a reduced capacity of the mutants for interaction with L-HDAg. In addition, a W196S S-HBsAg mutant, which has been described in HBV strains that arose in a few cases of lamivudine-treated HBV-infected patients, was deficient for HDV assembly as a consequence of its impaired capacity for interacting with L-HDAg. Interestingly, the fact that even the most conservative substitution of phenylalanine for tryptophan at positions 196, 199, or 201 was sufficient to ablate interaction of S-HBsAg with L-HDAg suggests that W196, W199, and W201 are located at a binding interface that is central to HDV maturation.
A 4D TWO-FLUID FRW COSMOLOGICAL MODEL IN INDUCED-MATTER THEORY
Authors: MA GUANG-WEN , YAO QIAN-KAI
Published: April 2006

In induced-matter theory, a 4D non-empty physical space–time is obtained from the 5D Ricci-flat one by setting the extra dimension coordinate equal to a constant. On the basis of this theory, we construct a 4D physical space–time by choosing a certain supersurface equation F(xA) = 0 (A runs over 0 ~ 4). It is shown that, the 4D two-fluid FRW cosmological model can be obtained from 5D flat space–time by specifying F(xA) = 0 as x4-x0 = 0.
ANALYSIS OF TRAPPED SURFACES IN HIGHER DIMENSIONAL DUST COLLAPSE
Authors: PATIL K. D.
Published: April 2006

We analyze the dynamics of an apparent horizon in higher dimensional (HD) dust collapse. We have taken into consideration two different types of dust models. We propose the concept of a "trapped range" of initial data in different higher dimensional space–times. We show that "trapped range" of initial data increases with the increase in dimensions of the space–times.
EARTH AZIMUTH EFFECT IN THE BANK OF SEARCH TEMPLATES FOR AN ALL-SKY SEARCH OF THE CONTINUOUS GRAVITATIONAL WAVE
Authors: SAHAY S. K.
Published: April 2006

We study the problem of all-sky search in reference to a continuous gravitational wave (CGW) whose wave-form is known in advance. We employ the concept of fitting factor and study the variation in the bank of search templates with different Earth azimuth at t = 0. We found that the number of search templates varies significantly. Hence, accordingly, the computational demand for the search may be reduced up to two orders by time shifting the data.
A CASE STUDY OF INFORMATION SYSTEMS DECISION-MAKING: PROCESS CHARACTERISTICS AND COLLABORATION TECHNOLOGY SUPPORT
Authors: MUNKVOLD BJØRN ERIK , EIM KRISTIN , HUSBY ØYVIND S.
Published: April 2006

The paper presents an analysis of a collaborative decision-making process related to the selection and implementation of a new corporate solution for collaboration and information management in a Norwegian oil company. Several challenges were identified in the decision-making process, related to ensuring continuity between different phases, enabling efficient communication among the different stakeholder groups, and gaining involvement and commitment from the business areas. The analysis also focuses on the utilization of various collaboration technologies in the different phases of the decision-making process. The use of a common information repository, a well established communications infrastructure, and skilled meeting facilitators, were important factors for successful completion of the project. A more differentiated and role-based access to the information repositories, and more extensive use of online discussion forums were identified as potential means for increasing involvement in the process and closing communication gaps between stakeholder groups. Further, combination of different technologies for supporting multimode interaction was identified as a potential way of enabling more effective interaction in time pressed activities. The study contributes to increase our understanding of collaborative IS decision-making processes, and the role of collaboration technologies for supporting these.
Targeted disruption of iNOS prevents LPS-induced S-nitrosation of IRβ/IRS-1 and Akt and insulin resistance in muscle of mice
Authors: Carvalho-Filho Marco A. , Ueno Mirian , Carvalheira José B. C. , Velloso Lício A. , Saad Mario J. A.
Published: April 2006

We have previously demonstrated that the insulin resistance associated with inducible nitric oxide synthase (iNOS) induction in two different models of obesity, diet-induced obesity and the ob/ ob mice, is mediated by S-nitrosation of proteins involved in insulin signal transduction: insulin receptor β-subunit (IRβ), insulin receptor substrate 1(IRS-1), and Akt. S-nitrosation of IRβ and Akt impairs their kinase activities, and S-nitrosation of IRS-1 reduces its tissue expression. In this study, we observed that LPS-induced insulin resistance in the muscle of wild-type mice, as demonstrated by reduced insulin-induced tyrosine phosphorylation of IRβ and IRS-1, reduced IRS-1 expression and reduced insulin-induced serine phosphorylation of Akt. This resistance occurred in parallel with enhanced iNOS expression, which was accompanied by S-nitrosation of IRβ/IRS-1 and Akt. In the muscle of iNOS−/− mice, we did not observe enhanced iNOS expression or any S-nitrosation of IRβ/IRS-1 and Akt after LPS treatment. Moreover, insulin resistance was not present. The preservation of insulin-induced tyrosine phosphorylation of IRβ and IRS-1, of IRS-1 protein expression, and of insulin-induced serine phosphorylation of Akt observed in LPS-treated iNOS−/− mice strongly suggests that the insulin resistance induced by LPS is iNOS mediated, probably through S-nitrosation of proteins of early steps of insulin signaling.
Glucocorticoid impairs growth of kidney outer medulla and accelerates loop of Henle differentiation and urinary concentrating capacity in rat kidney development
Authors: Stubbe Jane , Madsen Kirsten , Nielsen Finn Thomsen , Skøtt Ole , Jensen Boye L.
Published: April 2006

In the rat, urinary concentrating ability develops progressively during the third postnatal (P) week and nearly reaches adult level at weaning ( P21) governed by a rise in circulating glucocorticoid. Elevated extracellular osmolality can lead to growth arrest of epithelial cells. We tested the hypothesis that supranormal exposure of rat pups to glucocorticoid before the endogenous surge enhances urinary concentrating ability but inhibits renomedullary cell proliferation. Proliferating-cell nuclear antigen (PCNA)-positive cells shifted from the nephrogenic zone in the first postnatal week to Tamm-Horsfall-positive thick ascending limb (TAL) cells at the corticomedullary junction at P10– 14. Renal PCNA protein abundance was stable in the suckling period and decreased 10-fold after weaning. Renal PCNA protein abundance decreased in response to dexamethasone (DEXA; 100 μg·kg−1·day−1, P8–12). Prolonged administration of DEXA ( P1-P11) reduced selectively the area and thickness of the outer medulla and the number of PCNA-positive cells. DEXA ( P8– 12) increased urinary and papillary osmolality in normohydrated and water-deprived pups and led to osmotic equilibrium between interstitium and urine, whereas apoptotic and GADD153-positive cells increased in the inner medulla. TAL-associated NaCl transporters Na-K-2Cl cotransporter, Na-K-ATPase-α1, Na/H exchanger type 3, and ROMK increased significantly at weaning and in response to DEXA. We conclude that a low level of circulating glucocorticoid is permissive for proliferation of Henle's loop and the outer medulla before weaning. A reduced papillary tonicity is a crucial factor for the reduced capacity to concentrate urine during postnatal kidney development. We speculate that supranormal exposure to glucocorticoid in the suckling period can alter kidney medullary structure and function permanently.
A Coupled Model to Simulate Snow Behavior on Roads
Authors: Bouilloud Ludovic , Martin Eric
Published: April 2006

To develop a decision-making tool for road management in winter, a numerical model resulting from the coupling of a soil model and a snow model was developed and validated using experimental results from a comprehensive experimental field campaign during three winters (1997/98, 1998/99, and 1999/2000). The coupling of the models has been done through an implicit calculation of the conduction flux between snow and road. An equivalent thermal resistance has been used to take into account the different road–snow interface configurations. For this purpose, a parameterization of water-saturated snow was introduced. This model permits the simulation of the snow behavior on a road, and it takes into account different interfacial configurations according to snow and road types and the snowpack evolution (freezing, melting, grain type). Comparisons of experimental and simulated results for typical snowfall events or over the entire winter showed that the model was able to simulate road surface temperature, snow occurrence on the road, and snow-layer evolution with good accuracy.
A qualitative study in rural and urban areas on whether – and how – to consult during routine and out of hours
Authors: Campbell Neil C , Iversen Lisa , Farmer Jane , Guest Clare , MacDonald John
Published: April 2006

Background

Patients vary widely when making decisions to consult primary care. Some present frequently with trivial illness: others delay with serious disease. Differences in health service provision may play a part in this. We aimed to explore whether and how patients' consulting intentions take account of their perceptions of health service provision.

Methods

Four focus groups and 51 semi-structured interviews with 78 participants (45 to 64 years) in eight urban and rural general practices in Northeast and Southwest Scotland. We used vignettes to stimulate discussion about what to do and why. Inductive analysis identified themes and explored the influence of their perceptions of health service provision on decision-making processes.

Results

Anticipated waiting times for appointments affected consulting intentions, especially when the severity of symptoms was uncertain. Strategies were used to deal with this, however: in cities, these included booking early just in case, being assertive, demanding visits, or calling out-of-hours; in rural areas, participants used relationships with primary care staff, and believed that being perceived as undemanding was advantageous. Out-of-hours, decisions to consult were influenced by opinions regarding out-of-hours services. Some preferred to attend nearby emergency departments or call 999. In rural areas, participants tended to delay until their own doctor was available, or might contact them even when not on call.

Conclusion

Perceived barriers to health service access affect decisions to consult, but some patients develop strategies to get round them. Current changes in UK primary care are unlikely to reduce differences in consulting behaviour and may increase delays by some patients, especially in rural areas.
The regional differences in prevalence, medical expenditures and risk factors for injury in Taiwanese teenagers
Authors: Chen Huei-Yang , Chang Hsing-Yi , Shih Shu-Fang , Hsu Chih-Cheng , Lin Yu-Hsuan , Shih Yaw-Tang
Published: April 2006

Background

Injury is the leading cause of death in teenagers worldwide. In Taiwan, people in mountainous areas have a 4 to 8 years shorter life span than the general population. Injury among teenagers is likely a major cause. The objective of this study was to investigate the regional differences in the prevalence, the risk factors, and the medical expenditures for injury among Taiwanese teenagers.

Method

An equal probability national sample was used. In addition, representative samples from mountainous areas and offshore islands were used. Only those who aged between 12 and 21 years, and signed the consent form permitting us to link their National Health Insurance (NHI) claim data were included in the analysis. Injury-related visits and expenditures in outpatient services were extracted from the NHI data. Logistic regression was used to examine the factors associated with injury. For those who had injury related outpatient visits, mixed model was used to examine the factors associated with medical expenditures accounting for multiple visits by the same individual.

Results

The prevalence of nonfatal injury was around 30% of teenagers in Taiwan. It was 10% higher in mountainous areas. Factors associated with injury were those who lived in mountainous areas (adjusted odds ratio [OR]: 1.7; 95%; confidence interval [CI]: 1.3–2.3), males (OR: 1.3; 95%; CI: 1.1–1.6), older teens (18–21 years old), and those with risk behavior were positively associated with injury. These factors were also associated with the number of injury-related outpatient visits. However, teenagers in mountainous areas did not spend more on medical care than those who lived in metropolitan Taiwan.

Conclusion

Around 30% of the teenagers were injured in a year, not including the dead. Each of the injured spent at least 851.4NTD (~27USD) for outpatient visits. The scope of the problem was not trivial. Hazardous environments and high-risk behaviors were the universal causes. In remote areas, lack of medical resources was another possibility. Empowering local people to design prevention programs according to their needs is recommended.
Socio-demographic correlates of betel, areca and smokeless tobacco use as a high risk behavior for head and neck cancers in a squatter settlement of Karachi, Pakistan
Authors: Mazahir Samia , Malik Rabia , Maqsood Maria , Merchant Kanwal AliRaza , Malik Farida , Majeed Atif , Fatmi Zafar , Khawaja Muhammad Rizwanulhaq , Ghaffar Shehzad
Published: April 2006

Background

Head and neck cancers are a major cancer burden in Pakistan. They share a common risk factor profile including regular consumption of products of betel, areca and tobacco. Use of paan, chaalia, gutka, niswar and tumbaku is acceptable in Pakistan and is considered a normal cultural practice. This cross-sectional study was carried out to understand the relation of socio-demographic factors for the consumption of paan, chaalia, gutka, niswar and tumbaku in Pakistani population. Through systematic sampling, 425 subjects from a squatter settlement in Karachi were interviewed using a structured questionnaire. High risk behavior was defined as Daily use of any of the above products.

Results

Daily use of all the substances except chaalia was higher among males compared to females. Chaalia use was higher among adolescents than adults while non-married consumed both chaalia and gutka more than married. Mohajir ethnicity had higher prevalence of paan, gutka and tumbaku use while Pathans had higher prevalence of niswar use.

Conclusion

Prevalence of use of chewable products is high in Pakistan with particularly high use of certain substances related with socio-demographic profiles. Industrially prepared products, chaalia and gutka, are gaining popularity among youth. Policies and focused interventions can be developed taking into consideration the preferred use of products among different socio-demographic groups.
Inter-vesicular Communications by a Synthetic Amphiphilic Polypeptide
Authors: Kinoshita Takatoshi , Higuchi Masahiro , Takizawa Akira , Tsujita Yoshiharu
Published: April 2006

The direct vesicle-to-vesicle communication can be made by an amphiphilic polypeptide composed of two amphiphilic helices jointed with a hydrophilic spacer between them prepared by “Monolayer reaction method”.
A Possible Model Reaction of Dopamine β-Monooxygenase
Authors: Ito Sotaro , Takimura Mamoru , Sasaki Kazuo
Published: April 2006

Dopamine (3,4-dihydroxyphenethylamine) was oxidized with O2 in the presence of copper(II) sulfate and l-ascorbic acid to yield norepinephrine under ambient conditions. The active species generated from this system was assigned to OH radical by means of OH radical scavenging method.
A New Water-soluble p-Boronophenylalanine Derivative for Neutron Capture Therapy
Authors: Nemoto Hisao , Iwamoto Satoshi , Nakamura Hiroyuki , Yamamoto Yoshinori
Published: April 2006

A p-boronophenylalanine (BPA) derivative, that is ca. thousand times more water-soluble and is incorporated with higher tumour/normal cell ratio than BPA itself, has been synthesized.
Electrochemical Oxidation of Methanolic Solution of Sodium Cyanide. A Facile Formation of Dimethyl Oxaldiimidate
Authors: Chiba Toshiro , Okimoto Mitsuhiro
Published: April 2006

Dimethyl oxaldiimidate could be obtained in good yield by the electrolytic oxidation of methanolic solution of sodium cyanide in a divided cell using a carbon anode. Analogous electrolysis in an undivided cell gave dimethyl imidocarbonate as the main product.
Reversible Thermal Isomerization of Three Geometrical Isomers for Chlorobis(2-methyl-8-quinolinolato)nitrosylruthenium(III)
Authors: Ikezawa Hidenori , Miki Eiichi , Mizumachi Kunihiko , Ishimori Tatsujiro , Wakatsuki Yasuo
Published: April 2006

The reversible thermal isomerization among the trans and two kinds of cis geometrical isomers of [RuCl(2mqn)2(NO)] (2mqn = 2-methyl-8-quinolinolate ion) was observed in degassed DMSO (dimethyl sulfoxide) at higher than 363 K. The mole ratio of the cis-1, the cis-2, and the trans isomers was 20 : 9 : 1 after the equilibrium was reached at 413 K, and it did not depend on the starting species.
New Synthetic Strategy for the Construction of the BCD Ring System of Tanshinones
Authors: Shishido Kozo , Takata Takeshi , Omodani Tomoki , Shibuya Masayuki
Published: April 2006

Employing a strategy for the construction of fused furans based on an intramolecular [3+2] dipolar cycloaddition reaction of nitrile oxide, the BCD ring system 3 found in the tanshinone family as a common structural unit has been synthesized.
A Novel Photo-induced Fenton’s Reaction. Perfluorinated Poly(p-Phenylene)-catalyzed Photohydroxylation of Benzene with O2 and H2O to Phenol
Authors: Maruo Katsuya , Wada Yuji , Yanagida Shozo
Published: April 2006

18O Tracer study of perfluorinated poly(p-phenylene)-catalyzed photohydroxylation of benzene to phenol with H218O and 16O2 revealed that the hydroxylation initially occurs by the attack of the hydroxyl radical (H18O•) generated by the photooxidation of H218O, but the hydroxyl radical (H16O•) derived from the concurrently produced H216O2 comes to participate in further hydroxylation as the photocatalysis proceeds.
A New Ring System from Photocycloaddition of 6-Chloro-1 3-dimethyluracil to p- and m-Xylene. Formation of 6-Methylene-9,11,x-trimethyl-9,11-diazapentacyclo[6.4.0.01,3.02,5.04,8]dodecane-10,12-diones
Authors: Ohkura Kazue , Kanazashi Nobuhiko , Okamura Kimio , Date Tadamasa , Seki Koh-ichi
Published: April 2006

UV irradiation of 6-chloro-1,3-dimethyluracil in p- and m-xylene in the presence of trifluoroacetic acid gave the title compounds, novel cycloaddition products of the pyrimidine ring to the benzene moiety. Tetramethylcyclooctapyrimidine-2,4-diones were also yielded.
Inactivation of Gramicidin S by Acylation of Two Ornithine Residues with Higher Fatty Acids
Authors: Shimohigashi Yasuyuki , Ono Shin , Sakamoto Hiroshi , Yoshitomi Haruko , Waki Michinori , Ohno Motonori
Published: April 2006

Two δ-amino groups of ornithine2,2′ of antibiotic gramicidin S (GS) were modified with a series of the acyl groups CnH2n+1CO (n = 0–17). None of these diacylated analogs exhibited any antimicrobial activities for fifty kinds of bacteria examined, being in contrast to the previous study in which the derivatives of GS carrying acyl groups of n = 8–15 holded high activity (Uehara, Chem. Abstr., 54, 17279h (1960)). Careful comparisons of physicochemical properties between the analogs synthesized by us and by Uehara suggested that the reported high activities of diacylated GS might be attributable to contamination of unmodified GS.
Electrocatalytic Oxidation of NADH on Thin Poly(acrylic acid) Film Coated Graphite Felt Electrode Coimmobilizing Ferrocene and Diaphorase
Authors: Kashiwagi Yoshitomo , Osa Tetsuo
Published: April 2006

A thin poly(acrylic acid) film coated graphite felt electrode was chemically bonded with aminoferrocene and 2-aminoethylferrocene, and the properties of the latter bonded electrode (El 1) showed better electron transfer than the former bonded one. Then, El 1 was further bonded with diaphorase (Dp) to construct ferrocene (Fc)- and Dp-comodified electrode (El 2). El 2, which is stable and transfers electrons smoothly, was successfully used for the preparative and selective electrocatalytic oxidation of NADH to NAD+, being capable of repeated use without any appreciable inactivation.
A Novel Method for Synthesis of Cellooligosaccharide Derivatives by Using Enzyme Catalyst
Authors: Kobayashi Shiro , Kawasaki Tatsuya , Obata Kei , Shoda Shin-ichiro
Published: April 2006

A new methodology for regio and stereoselective synthesis of cellooligosaccharide derivatives has been developed by utilizing the following two enzymatic reactions: A cellulase-catalyzed stereoselective lactosylation of an alkyl cellobioside giving rise to a new oligosaccharide having a D-galactose unit at the non-reducing end and a β-galactosidase-catalyzed regioselective cleavage of the terminal D-galactose unit of the product.
Efficient Oxygenation of Alkene through Reductive Quenching of Excited Sb(V)tetraphenylporphyrin by Triphenylphosphine
Authors: Okamoto Takanobu , Takagi Shinsuke , Shiragami Tsutomu , Inoue Haruo
Published: April 2006

Novel efficient oxygenation route of cyclohexene into 2-cyclohexen-1-one (Φ = 0.14) upon visible light irradiation to tetraphenylporphyrinatoantimony(V) through reductive quenching of the excited triplet porphyrins by triphenylphosphine in aqueous acetonitrile has been found.
Structure and Conducting Properties of TMET-TTP Radical-Cation Salts
Authors: Mori Takehiko , Inokuchi Hiroo , Misaki Yohji , Nishikawa Hiroyuki , Yamabe Tokio , Mori Hatsumi , Tanaka Shoji
Published: April 2006

Radical cation salts of TMET-TTP (2-(4′,5′-bis(thiomethyl)-1′,3′-dithiol-2′-ylidene)-5-(4″,5″-ethylenedithio-1″,3″-dithiol-2″-ylidene)-1,3,4,6-tetrathiapentalene) with various anions show high electrical conductivity. Many of them have a similar structure with two-dimensional donor arrangement.
An Unusual 1-Oxa-2-sila-3-cyclopentene Ring Formation in the Palladium Catalyzed Reaction of Thallium Compound with 2-Methyl-4-trimethylsilyl-3-butyn-2-ol
Authors: Ohta Toshiharu , Shinoda Junko , Somei Masanori
Published: April 2006

A palladium catalyzed reaction of (3-formylindol-4-yl)thallium(III) bistrifluoroacetate with 2-methyl-4-trimethylsilyl-3-butyn-2-ol gave 4-(2,2,3,5,5-pentamethyl-1-oxa-2-sila-3-cyclopenten-4-yl)indole-3-carboxaldehyde.
Crowned-coumarin as a New Fluorescence Derivatization Reagent for Carboxylic Acids
Authors: Takadate Akira , Masuda Toshinobu , Murata Chiyomi , Tanaka Toshiharu , Miyahara Hiroshi , Goya Shujiro
Published: April 2006

3-Bromoacetyl-6,7-[2′,3′-(1′,4′,7′,10′,13′-pentaoxacyclopentadeca)-2′-ene]coumarin (2) was prepared as a new fluorescence derivatization reagent for carboxylic acids in high-performance liquid chromatographic analysis. The derivatization of lauric acid with 2 was readily accomplished under a quite mild condition to yield a highly fluorescent lauric acid derivative. The reaction was accelarated by combining crown moiety as a catalytic site to coumarin fluorophore.
Kinetics and Diffusing Species in the Reaction between Molybdenum and Selenium Vapor
Authors: Sasaki Yoshinori , Wakatsuki Noboru
Published: April 2006

Metallic molybdenum was selenidized at temperatures of 773–873 K in selenium vapor at 1.33 kPa. The reaction products were identified to be MoSe2 alone under all the experimental conditions. All the selenidizations obeyed a parabolic rate law. A marker experiment indicated that selenium was the component which diffused.