bluuebunny/crossref_metadata_2025 huggingface dataset:
From consultation to participatory governance? A critical review of citizen engagement strategies in Queensland
Authors: Reddel Tim , Woolcock Geoff
Published: September 2004

This article explores what appears to be a major shift in the policies and practices of national and international governments–the increased attention to, and use of, citizen engagement strategies as a basis for developing more participatory forms of governance. The article examines recent citizen engagement initiatives of the Queensland state government which have grappled with these complex political, policy and service concerns. The potential innovation and effectiveness of citizen engagement techniques and approaches are examined. The limitations of technical methodologies based on a traditional consultative framework are highlighted. The article analyses the relationship between these citizen engagement practices and more strategic democratic reforms based on notions of participatory governance.
The Community Funding Agency and the voluntary sector: Purchase of service contracting in Otago/Southland
Authors: Majumdar Debiprosad
Published: September 2004

The purpose of this article is to study the efficacy and deficiency of purchase of service contracting in helping the voluntary organisations in the Otago/Southland region in New Zealand and the Community Funding Agency (now defunct) achieve a set of specific objectives. The findings are based on the information collected from (a) the responses of 57 participating voluntary organisations to the questionnaire mailed to them, and (b) face‐to‐face, open‐ended interviews with 28 voluntary sector managers, the three outreach workers operating in the Otago/Southland area at the time of writing and eight people formerly associated with the Community Funding Agency at senior management level. The data obtained through field research are verified with prevailing literature–local as well as international.
International Evidence on the Stability of the Optimizing IS Equation*
Authors: Kara Amit , Nelson Edward
Published: September 2004

We provide international evidence on the issue of whether the optimizing IS equation is more stable than a backward‐looking alternative. This evidence consists of estimates of IS equations on quarterly data for the UK and Australia, both for the full sample of the last 40 years and for the period following major monetary policy shifts in 1979–80. Results suggest the parameters in the optimizing IS equations are more empirically stable than those of the backward‐looking alternative. The use of dynamic general equilibrium modelling in empirical work does deliver material benefits, in the form of equations more suitable for policy analysis.
Evaluating New‐Keynesian Models of a Small Open Economy*
Authors: Giordani Paolo
Published: September 2004

We suggest a strategy to evaluate members of a class of New‐Keynesian models of a small open economy. As an example, we estimate a modified version of the model in Svensson [Journal of International Economics (2000) Vol. 50, pp. 155–183] and compare its impulse response and variance decomposition functions with those a structural vector autoregression (VAR) model. The focus is on responses to foreign rather than to domestic shocks, which facilitates identification. Some results are that US shocks account for large shares of the variance of Canadian variables, that little of this influence is due to real exchange rate movements, and that Canadian monetary policy is not adequately described by a Taylor rule.
ImaginingThe Sociological Imagination: the biographical context of a sociological classic
Authors: Brewer John D.
Published: September 2004

Charles Wright Mills's arguments inThe Sociological Imaginationare very popular and this paper focuses on the biographical context in which his programmatic statements were occasioned. This breaks new ground by locatingThe Sociological Imaginationand earlier programmatic statements in the professional and personal travails that motivated them. This approach is adopted in order to display the intersection between biography and sociology in Mills's life and career, a feature that he made a central part of sociology's promise. The paper utilizes this approach to reflect on the reasons whyThe Sociological Imaginationbecame so popular and was able to transcend Mills's general unpopularity at the time of his death; and as part of the explanation of why the dismissal of the book on its publication contrasts with the contemporary view, enabling it to transpose successfully to a time significantly different than at its writing.
Signal crimes and signal disorders: notes on deviance as communicative action1
Authors: Innes Martin
Published: September 2004

In this paper a ‘signal crimes’ perspective is outlined in an effort to unpack the relationships between experiences of crime and disorder, and perceptions of criminogenic risk. Grounded in symbolic interactionist sociology, and developing a social semiotic understanding of risk perception, it is a perspective that focuses upon processes of social reaction and the ways in which people interpret and define threats to their security. It is proposed that people interpret the occurrence of certain incidents as ‘warning signals’ about the levels of risk to which they are either actually or potentially exposed. These signals tend to take the form of signal crimes and/or signal disorders and are important in terms of how social space is symbolically constructed.
Socio‐historical paths of the male breadwinner model – an explanation of cross‐national differences1
Authors: Pfau‐Effinger Birgit
Published: September 2004

It is often assumed that in the historical transformation to modern industrial society, the integration of women into the economy occurred everywhere as a three‐phase process: in pre‐modern societies, the extensive integration of women into societal production; then, their wide exclusion with the shift to industrial society; and finally, their re‐integration into paid work during the further course of modernization. Results from the author's own international comparative study of the historical development of the family and the economic integration of women have shown that this was decidedly not the case even for western Europe.

Hence the question arises: why is there such historical variation in the development and importance of the housewife model of the male breadwinner family? In the article, an explanation is presented. It is argued that the historical development of the urban bourgeoisie was especially significant for the historical destiny of this cultural model: the social and political strength of the urban bourgeoisie had central societal importance in the imposition of the housewife model of the male breadwinner family as the dominant family form in a given society. In this, it is necessary to distinguish between the imposition of the breadwinner marriage at the cultural level on the one hand, and at the level of social practice in the family on the other.
Appliances and their impact: the ownership of domestic technology and time spent on household work
Authors: Bittman Michael , Rice James Mahmud , Wajcman Judy
Published: September 2004

Ever since the appearance of Vanek's pioneering article in 1974, there has been a controversy about whether ‘labour saving’ domestic appliances actually save labour time. Vanek argued that time spent in housework had barely changed since 1926, despite the diffusion of practically every known domestic appliance over this period. Gershuny and Robinson challenge Vanek's ‘constancy of housework’ thesis, arguing that, between 1965 and 1985, domestic technology has significantly reduced the weekly hours of women's routine housework. Although there is much talking past each other, none of the protagonists in this dispute have any direct data about which households own or do not own domestic appliances. Instead, they all rely on the passage of the years as a proxy for ownership of domestic appliances, since a higher proportion of contemporary households now own domestic appliances. The Australian 1997 Time Use Survey (Australian Bureau of Statistics 1998b) is rare among official surveys, as it simultaneously provides detailed information on time spent in housework and an inventory of household appliances. The analysis of this data show that domestic technology rarely reduces women's unpaid working time and even, paradoxically, produces some increases in domestic labour. The domestic division of labour by gender remains remarkably resistant to technological innovation.
The expression of NMDA receptor 1 is associated with clinicopathological parameters and prognosis in the oral squamous cell carcinoma
Authors: Choi S.‐W. , Park S.‐Y. , Hong S.‐P. , Pai H. , Choi J.‐Y. , Kim S.‐G.
Published: September 2004

Background:  Glutamate activates the N‐methyl‐d‐aspartate (NMDA) receptors and this receptor is involved in the proliferation and migration of various tumour cells in vitro. However, the relationship between NMDA receptor expression and clinical parameters in cancer patients is unclear. Therefore, NMDA receptor 1 (NMDAR1) expression along with its clinical significance was examined in patients with oral squamous cell carcinoma (OSCC).

Methods:  Eighty‐one tumour specimens from OSCC patients were used to determine the NMDAR1 expression level by immunohistochemical staining. The control was obtained from a matched normal adjacent mucosa. The cases were considered to be positive if reactivity was displayed in >25% of the cells.

Results:  The NMDAR1 reactivity was positive in 50 of 81 cases, while it was negative in the control. NMDAR1 expression was significantly associated with a lymph node metastasis (P = 0.008), the tumour size (P < 0.001), and the cancer stage (P = 0.034). The patients whose tumours expressed NMDAR1 had a significantly poorer survival than the patients who were NMDAR1‐negative (log‐rank = 6.45, d.f. = 1, P = 0.011).

Conclusions:  The NMDAR1 overexpression was significantly associated with the prognosis‐related factors. Therefore, it might be one of the prognostic markers of OSCC.
Effects of arecoline, safrole, and nicotine on collagen phagocytosis by human buccal mucosal fibroblasts as a possible mechanism for oral submucous fibrosis in Taiwan
Authors: Shieh Dean‐Hwa , Chiang Lien‐Chai , Lee Chien‐Hung , Yang Yi‐Hsin , Shieh Tien‐Yu
Published: September 2004

Background:  Oral submucous fibrosis (OSF) is associated with the betel quid chewing habit, and 86% of betel quid chewers in Taiwan are also smokers. Arecoline and safrole are major principles in the composition of betel quid, and nicotine is the main toxic ingredient of cigarettes.

Methods:  To explore the pathogenesis of OSF, flow cytometry was used to compare collagen phagocytosis by fibroblasts from the normal and the OSF region of the same 15 OSF patients.

Results:  The results indicated that heterogeneity of fibroblasts existed because collagen phagocytosis by fibroblasts from the normal region was higher than from the OSF region in the same patient. The percentage of phagocytic cells was significantly inhibited by 10, 25 and 50 μg/ml arecoline, safrole and nicotine in normal fibroblast cultures, respectively, and the percentage of phagocytic cells was significantly reduced by 25, 25 and 50 μg/ml arecoline, safrole and nicotine in OSF fibroblast cultures, respectively. Collagen phagocytosis by fibroblasts exhibited prominent dose‐dependent inhibition as the concentration of arecoline, safrole, and nicotine increased. Besides, nicotine had a synergistic effect on arecoline‐ or safrole‐inhibited collagen phagocytosis.

Conclusions:  The present study concludes that even in the same person, the collagen phagocytosis by fibroblasts is different between normal and OSF region. The deficiency in collagen phagocytosis by fibroblasts of the lesion might participate in the pathogenesis of OSF. Arecoline, safrole and nicotine, which are released in saliva during BQ chewing plus cigarette smoking, inhibit collagen phagocytosis by fibroblasts in a dose‐dependent manner and may induce OSF formation in Taiwan's patients.
Expression patterns of integrins on pleomorphic adenoma and adenoid cystic carcinoma: study on specimens and in vitro investigation of the effects of extracellular matrix on the expression of these adhesion molecules
Authors: Lourenço S. V. , Kapas S. , Williams D. M. , Leite K. , Araújo V. C.
Published: September 2004

Background:  Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) are neoplasms of distinct behaviour, showing similar origin, cell components and marked presence of extracellular matrix (ECM). Interactions between cells and ECM are important in the biology of tumours, being partially mediated by integrins. This study investigated these interactions on PA and ACC using paraffin‐embedded tissue and an in vitro model of these conditions.

Methods:  Expression of integrins in paraffin‐embedded samples was assessed by immunohistochemistry. Cells from PA and ACC were characterized using immunofluorescence, and integrin patterns of expression were investigated on cells cultivated on different ECM proteins.

Results:  Luminal cells of both PA and ACC were more intensely positive for integrins than myoepithelial cells. In vitro studies revealed that PA cells expressed more integrins than ACC cells regardless the ECM protein present.

Conclusions:  This study revealed particular patterns of integrin expression in both specimens and in vitro models of PA and ACC. This might prove useful for a better understanding of the biology of these lesions.
Increased mast cell density and protease content in actinic cheilitis
Authors: Rojas I. G. , Martínez A. , Pineda A. , Spencer M. L. , Jiménez M. , Rudolph M. I.
Published: September 2004

Background:  Actinic cheilitis (AC) is a pre‐malignant lesion caused by ultraviolet (UV) radiation and characterized by epithelial and connective tissue alterations. Mast cells (MCs), key contributors to solar elastosis in murine UV‐irradiated skin, were characterized in order to assess their potential contribution to connective tissue degeneration in AC.

Methods:  Actinic cheilitis (n = 15) and normal lip (n = 8) biopsies were stained immunohistochemically for tryptase and enzymehistochemically for chymase to determine MC density and protease content. MC subpopulations (i.e. MCT containing only tryptase, and MCTC containing chymase and tryptase) and their distribution were also determined.

Results:  Mast cells and their proteases were increased in AC as compared with normal lip (P < 0.0001), and appeared degranulated especially around elastotic areas. MCT predominated over MCTC in AC and normal lip (P < 0.05). However, in AC MCT were increased in the epithelium/connective junction and connective area (P < 0.05), while in normal lip MCT predominated in connective and submucosal areas (P < 0.05).

Conclusion:  The results suggest that increased MC density and protease content may contribute to elastosis formation in AC. In addition, changes in MCT distribution may favor AC malignization.
The Modeling of Thin Liquid Films Along Inclined Surfaces
Authors: Podowski Michael Z. , Kumbaro Anela
Published: September 2004

This paper is concerned with the analysis of thin and ultra-thin liquid films. The results are applicable to various geometrical and kinematic conditions, including both stationary and moving surfaces. The new results obtained in this work include: • the derivation of an analytical solution for the evolution of film thickness over the entire multiscale range, from the liquid free surface to the asymptotic (disjoining-pressure controlled) region, and for any surface inclination angle between 0 deg and 90 deg, • the formulation of a method to deduce the Hamaker constant based on a single measured value of film thickness at the beginning of the disjoining-pressure-controlled region, applicable to any inclination angle, • the explanation of the reasons why the thickness of liquid films on moving surfaces is normally beyond the range of Van der Waals forces, • the formulation of an expression for the nondimensional asymptotic film thickness as a function of the capillary number; this new result explicitly accounts for the effect of gravity on the average film velocity.
Application of Preconditioning Method to Gas-Liquid Two-Phase Flow Computations
Authors: Shin Byeong Rog , Yamamoto Satoru , Yuan Xin
Published: September 2004

A preconditioned numerical method for gas-liquid two-phase flows is applied to solve cavitating flow. The present method employs a finite-difference method of the dual time-stepping integration procedure and Roe’s flux difference splitting approximation with the MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. The present density-based numerical method permits simple treatment of the whole gas-liquid two-phase flow field, including wave propagation, large density changes and incompressible flow characteristics at low Mach number. Two-dimensional internal flows through a backward-facing step duct, convergent-divergent nozzles and decelerating cascades are computed using this method. Comparisons of predicted and experimental results are provided and discussed.
The Modeling of Lift and Dispersion Forces in Two-Fluid Model Simulations of a Bubbly Jet
Authors: Lopez de Bertodano M. , Moraga F. J. , Drew D. A. , Lahey, R. T.
Published: September 2004

Two-fluid model simulations of a bubbly vertical jet are presented. The purpose of these simulations is to assess the modeling of lift and turbulent dispersion forces in a free shear flow. The turbulent dispersion models used herein are based on the application of a kinetic transport equation, similar to Boltzmann’s equation, to obtain the turbulent diffusion force for the dispersed phase [1–4]. They have already been constituted and validated for the case of particles in homogeneous turbulence and jets [5] and for microscopic bubbles in grid generated turbulence and mixing layers [6,7]. It was found that it is possible to simulate the experimental data of Sun [8] (see Figs. 1–6) for a bubbly jet with 1 mm diameter bubbles. Good agreement is obtained using the model of Brucato et al. [9] for the modulation of the drag force by the liquid phase turbulence and a constant lift coefficient, CL. However, little sensitivity is observed to the value of the lift coefficient in the range 0<CL<0.29.
Oil-Water Separation in a Novel Liquid-Liquid Cylindrical Cyclone (LLCC©) Compact Separator—Experiments and Modeling
Authors: Oropeza-Vazquez C. , Afanador E. , Gomez L. , Wang S. , Mohan R. , Shoham O. , Kouba G.
Published: September 2004

The hydrodynamics of multiphase flow in a Liquid-Liquid Cylindrical Cyclone (LLCC) compact separator have been studied experimentally and theoretically for evaluation of its performance as a free water knockout device. In the LLCC, no complete oil-water separation occurs. Rather, it performs as a free-water knockout, delivering a clean water stream in the underflow and an oil rich stream in the overflow. A total of 260 runs have been conducted, measuring the LLCC separation efficiency for water-dominated flow conditions. For all runs, an optimal split-ratio (underflow to inlet flow rate ratio) exists, where the flow rate in the water stream is maximum, with 100% watercut. The value of the optimal split-ratio depends upon the existing inlet flow pattern, and varies between 60% and 20%. For split-ratios higher than the optimal one, the watercut in the underflow stream decreases as the split-ratio increases. A novel mechanistic model has been developed for the prediction of the complex flow behavior and the separation efficiency in the LLCC. Comparisons between the experimental data and the LLCC model predictions show excellent agreement. The model is capable of predicting both the trend of the experimental data as well as the absolute measured values. The developed model can be utilized for the design and performance analysis of the LLCC.
Aerobreakup in Rarefied Supersonic Gas Flows
Authors: Theofanous T. G. , Li G. J. , Dinh T. N.
Published: September 2004

We present new experimental results on the interfacial instabilities and breakup of Newtonian liquid drops suddenly exposed to rarefied, high-speed (Mach 3) air flows. The experimental approach allows for the first time detailed observation of interfacial phenomena and mixing throughout the breakup cycle over a wide range of Weber numbers. Key findings are that Rayleigh-Taylor instability alone is the active mechanism for freestream Weber numbers as low as 28 for low viscosity liquids and that stripping rather than piercing is the asymptotic regime as We→∞. This and other detailed visual evidence over 26<We<2,600 are uniquely suitable for testing Computational Fluid Dynamics (CFD) simulations on the way to basic understanding of aerobreakup over a broad range of conditions.
The Characteristics-Based Matching (CBM) Method for Compressible Flow With Moving Boundaries and Interfaces
Authors: Nourgaliev R. R. , Dinh T. N. , Theofanous T. G.
Published: September 2004

Recently, Eulerian methods for capturing interfaces in multi-fluid problems become increasingly popular. While these methods can effectively handle significant deformations of interface, the treatment of the boundary conditions in certain classes of compressible flows are known to produce nonphysical oscillations due to the radical change in equation of state across the material interface. One promising recent development to overcome these problems is the Ghost Fluid Method (GFM). The present study initiates a new methodology for boundary condition capturing in multifluid compressible flows. The method, named Characteristics-Based Matching (CBM), capitalizes on recent developments of the level set method and related techniques, i.e., PDE-based re-initialization and extrapolation, and the Ghost Fluid Method (GFM). Specifically, the CBM utilizes the level set function to capture interface position and a GFM-like strategy to tag computational nodes. In difference to the GFM method, which employs a boundary condition capturing in primitive variables, the CBM method implements boundary conditions based on a characteristic decomposition in the direction normal to the boundary. In this way overspecification of boundary conditions is avoided and we believe so will be spurious oscillations. In this paper, we treat (moving or stationary) fluid-solid interfaces and present numerical results for a select set of test cases. Extension to fluid-fluid interfaces will be presented in a subsequent paper.
A Stochastic Model for Gravity Effects in Particle-Laden Turbulent Flows
Authors: Gao Z. , Mashayek F.
Published: September 2004

A stochastic model is presented for the prediction of the gravity effects on velocity and temperature fluctuations in turbulent flows laden with solid particles. Both temporal and spatial correlations as well as the anisotropy of turbulence are included in the model. It is found that the inclusion of the spatial correlation is imperative for capturing the gravity effects. The performance of the stochastic model is assessed by comparisons of the results with direct numerical simulation data for isotropic and homogeneous shear turbulent flows. The comparisons are also used to investigate the effect of the empirical constant that appears in the expression used for the spatial correlation.
Effects of Inclination Angle of Ribs on the Flow Behavior in Rectangular Ducts
Authors: Gao Xiufang , Sunde´n Bengt
Published: September 2004

The flow behavior in rib-roughened ducts is influenced by the inclination of ribs and the effect is investigated in the present study by Particle Image Velocimetry (PIV). The local flow structures between two adjacent ribs were measured. The Reynolds number was fixed at 5800. The flow field description was based on the PIV results in planes both parallel and perpendicular to the ribbed walls at various locations. The rib angle to the main flow direction was varied as 30 deg, 45 deg, 60 deg and 90 deg. The ribs induce three dimensional flow fields. The flow separation and reattachment between adjacent ribs are clearly observed. In addition, the inclined ribs are found to alter the spanwise distribution of the streamwise velocity component. The streamwise velocity component has its highest values at the upstream end of the ribs, and decreases continuously to its lowest values at the downstream end. Strong secondary flow motion occurs over the entire duct cross section for the inclined ribs. The flow structures between two consecutive ribs show that the fluid flows along the ribs from one end of the ribs to the other end, and then turns back at the transverse center. Downwash and upwash flows are observed at the upstream end and downstream end of the ribs, respectively.
Momentum Flux in Plane, Parallel Jets
Authors: Spall Robert E. , Anderson Elgin A. , Allen Jeffrey
Published: September 2004

The evolution of the streamwise momentum flux for two turbulent, plane, parallel jets discharging through slots in a direction normal to a wall was studied both numerically and experimentally. The numerical results, obtained by solving the Reynolds-averaged Navier-Stokes equations employing a standard k−ε turbulence model, predicted to within experimental error measured integrals of the momentum flux downstream of the merge point for jet spacing S/d=5. Integration of the streamwise component of the Reynolds-averaged Navier-Stokes equations over a control volume results in an integral constant that was evaluated numerically for jet spacings S/d=3, 5, 7, 9, and 11, and for different levels of turbulence kinetic energy and dissipation rate at the jet inlet boundaries. Results revealed that the integral constant is decreased as the jet spacing increases, and is also decreased as jet entrainment rates are increased due to higher levels of inlet turbulence kinetic energy, or alternatively, decreased levels of dissipation rate. Streamwise distance to the merge point was also found to decrease for increased levels of turbulence kinetic energy or decreased levels of dissipation rate at the jet inlet.
Modeling the Rapid Part of the Pressure-Diffusion Process in the Reynolds Stress Transport Equation
Authors: Suga Kazuhiko
Published: September 2004

Modeling the pressure-diffusion process is discussed to improve the prediction of turbulent recirculating flows by a second moment closure. Since the recent DNS research of a turbulent recirculating flow by Yao et al. [Theore. Comput. Fluid Dynamics 14 (2001) 337–358] suggested that the pressure-diffusion process of the turbulence energy was significant in the recirculating region, the present study focuses on the rapid part of the process consisting of the mean shear. This rapid pressure-diffusion model is developed for the Reynolds stress equation using the two-component-limit turbulence condition and added to a low Reynolds number two-component-limit full second moment closure for evaluation. Its effects are discussed through applications of turbulent recirculating flows such as a trailing-edge and a back-step flows. Encouraging results are obtained though some margins to be improved still remain.
Secondary Flow Control Using Vortex Generator Jets
Authors: Sullerey R. K. , Pradeep A. M.
Published: September 2004

In this paper, results are presented of an experimental investigation into the effectiveness of vortex generator jets in controlling secondary flows in two-dimensional S-duct diffusers. The experiments were performed in uniform and distorted inflow conditions and the performance evaluation of the diffuser was carried out in terms of static pressure recovery and quality of the exit flow. In the case with inflow distortion, tapered fin vortex generators were employed in addition to vortex generator jets to control flow separation that was detected on the wall with inflow distortion. Detailed measurements including total pressure, velocity distribution, surface static pressure, skin friction, and boundary layer measurements were taken at a Reynolds number of 7.8×105. These results are presented in terms of static pressure rise, distortion coefficient, and total pressure loss coefficient at the duct exit. For uniform inflow, the use of vortex generator jets resulted in more than a 30 percent decrease in total pressure loss and flow distortion coefficients. In combination with passive device (tapered fin vortex generators), the vortex generator jets reduce total pressure losses by about 25 percent for distorted inflow conditions. A potential application of this method may include control of secondary flows in turbo machinery.
The Influence of Small Particles on the Structure of a Turbulent Shear Flow
Authors: Graham David I.
Published: September 2004

In this paper, an analytical solution is found for the Reynolds equations describing a simple turbulent shear flow carrying small, wake-less particles. An algebraic stress model is used as the basis of the model, the particles leading to source terms in the equations for the turbulent stresses in the flow. The sources are proportional to the mass loading of the particles and depend on the temporal correlations of the fluid velocities seen by particles, Rijτ. The resulting set of equations is a system of nonlinear algebraic equations for the Reynolds stresses and the dissipation. The system is solved exactly and the influence of the particles can be quantified. The predictions are compared with DNS results and are shown to predict trends quite well. Different scenarios are investigated, including the effects of isotropic, anisotropic and non-equilibrium time scales and negative loops in Rijτ. The general trend is to increase anisotropy and attenuate turbulence with higher mass loadings. The occurrence of turbulence enhancement is investigated and shown to be theoretically possible, but physically unlikely.
On the Criterion for the Determination Transition Onset and Breakdown to Turbulence in Wall-Bounded Flows1
Authors: Jovanovic´ J. , Pashtrapanska M.
Published: September 2004

Starting from the basic conservation laws of fluid flow, we investigated transition and breakdown to turbulence of a laminar flat plate boundary layer exposed to small, statistically stationary, two-component, three-dimensional disturbances. The derived equations for the statistical properties of the disturbances are closed using the two-point correlation technique and invariant theory. By considering the equilibrium solutions of the modeled equations, the transition criterion is formulated in terms of a Reynolds number based on the intensity and the length scale of the disturbances. The deduced transition criterion determines conditions that guarantee maintenance of the local equilibrium between the production and the viscous dissipation of the disturbances and therefore the laminar flow regime in the flat plate boundary layer. The experimental and numerical databases for fully developed turbulent channel and pipe flows at different Reynolds numbers were utilized to demonstrate the validity of the derived transition criterion for the estimation of the onset of turbulence in wall-bounded flows.
An Experimental Study on the Influence of Flow Maldistribution on the Pressure Drop Across a Plate Heat Exchanger
Authors: Rao B. Prabhakara , Das Sarit K.
Published: September 2004

A detailed experimental study on flow maldistribution from port to channel of a plate heat exchanger is presented. In general, flow maldistribution brings about an increase in pressure drop across the heat exchanger. This increase is found to depend on flow rate, number of channels and port size. Experiments show that analytical predictions of pressure drop including maldistribution effect are quite accurate for practical purposes. The results indicate that under identical conditions, maldistribution is more severe in Z-type plate heat exchanger compared to U type. Experiments are also carried out under non-isothermal realistic operating conditions, which show increased flow maldistribution at elevated temperature. Finally predictions are made for industrial plate heat exchangers, which show the limitation of adding additional plates beyond a certain limit. An insight to the physical aspects of maldistribution and its possible reduction through proper design strategy is also indicated.
The Design of a New Flow Meter for Pipes Based on the Drag Force Exerted on a Cylinder in Cross Flow (Drag Force Flow Meter: DFFM)
Authors: Ruppel C. , Funke T. , Peters F.
Published: September 2004

It is shown how to design a new method (DFFM) of flow metering in pipes from basic principles. The method relies on the well known drag force on a cylindrical body and the force measurement by a load cell. The drag force is exclusively measured in the axial flow direction, the only one that contributes to the flow rate. That way disturbing tangential swirl components which do not contribute remain unconsidered. By means of an upstream screen the meter is desensitized to disturbing axial velocity profile distortions. Testing with various installations demonstrates the main features and the error bar to be expected.
Jun Turnover Is Controlled Through JNK-Dependent Phosphorylation of the E3 Ligase Itch
Authors: Gao Min , Labuda Tord , Xia Ying , Gallagher Ewen , Fang Deyu , Liu Yun-Cai , Karin Michael
Published: September 2004

The turnover of Jun proteins, like that of other transcription factors, is regulated through ubiquitin-dependent proteolysis. Usually, such processes are regulated by extracellular stimuli through phosphorylation of the target protein, which allows recognition by F box–containing E3 ubiquitin ligases. In the case of c-Jun and JunB, we found that extracellular stimuli also modulate protein turnover by regulating the activity of an E3 ligase by means of its phosphorylation. Activation of the Jun amino-terminal kinase (JNK) mitogen-activated protein kinase cascade after T cell stimulation accelerated degradation of c-Jun and JunB through phosphorylation-dependent activation of the E3 ligase Itch. This pathway modulates cytokine production by effector T cells.
Single-Atom Spin-Flip Spectroscopy
Authors: Heinrich A. J. , Gupta J. A. , Lutz C. P. , Eigler D. M.
Published: September 2004

We demonstrate the ability to measure the energy required to flip the spin of single adsorbed atoms. A low-temperature, high–magnetic field scanning tunneling microscope was used to measure the spin excitation spectra of individual manganese atoms adsorbed on Al
2
O
3
islands on a NiAl surface. We find pronounced variations of the spin-flip spectra for manganese atoms in different local environments.
Controlling the Dynamics of a Single Atom in Lateral Atom Manipulation
Authors: Stroscio Joseph A. , Celotta Robert J.
Published: September 2004

We studied the dynamics of a single cobalt (Co) atom during lateral manipulation on a copper (111) surface in a low-temperature scanning tunneling microscope. The Co binding site locations were revealed in a detailed image that resulted from lateral Co atom motion within the trapping potential of the scanning tip. Random telegraph noise, corresponding to the Co atom switching between hexagonal close-packed (hcp) and face-centered cubic (fcc) sites, was seen when the tip was used to try to position the Co atom over the higher energy hcp site. Varying the probe tip height modified the normal copper (111) potential landscape and allowed the residence time of the Co atom in these sites to be varied. At low tunneling voltages (less than ∼5 millielectron volts), the transfer rate between sites was independent of tunneling voltage, current, and temperature. At higher voltages, the transfer rate exhibited a strong dependence on tunneling voltage, indicative of vibrational heating by inelastic electron scattering.
CONDITIONS FOR CONSISTENT EXPONENTIAL-POLYNOMIAL FORWARD RATE PROCESSES WITH MULTIPLE NONTRIVIAL FACTORS
Authors: SHAREF EMMANUEL , FILIPOVIĆ DAMIR
Published: September 2004

We present conditions that allow consistent exponential-polynomial forward curve models with two exponential terms to have more than one nontrivial factor. This result leads to seven- and nine-parameter extensions of the Svensson model, for which the consistency conditions allow for two and three stochastic parameters respectively.
VALUATION, TAX SHIELDS AND THE COST-OF-CAPITAL WITH PERSONAL TAXES: A FRAMEWORK FOR INCORPORATING TAXES
Authors: SCHULTZE WOLFGANG
Published: September 2004

This paper presents a general approach to deriving valuation models and the relevant cost of capital formulas independent of a particular tax environment. The value of a levered firm depends to a large extent upon the amount and value of the tax shields. The latter in turn differs from country to country and even from firm to firm, depending on its particular situation. It is subject to change with every change in the tax system of the country where the firm is located. Therefore, in an international environment a general approach is needed, which can be altered for any given situation. At the same time personal taxes play an increasing role in the valuation of companies. Therefore, their consideration is integrated into the models derived. Finally, the resulting generalized versions of the Modigliani/Miller- and Miles–Ezzell-Formulas for adjusting the cost of capital to changes in leverage are applied to the situation of a corporation located in Germany after the Tax Reform Act of 2000.
OPTION PRICING WITH FEEDBACK EFFECTS
Authors: LYUKOV ALEXANDER
Published: September 2004

The paper provides a continuous time model for order-driven stock market. The model allows to derive a nonlinear PDE as a modification of Black–Scholes equation for option pricing with a local volatility as a function of the stock price. The solution can be expanded in series in the parameter, which relates to the size of option market. The first-order correction for the option price increases the price of a European call. The second-order correction for volatility allows to describe the "volatility smile".
CORPORATE BOND RISK FROM STOCK DIVIDEND UNCERTAINTY
Authors: WISE MARK B. , LEE PETER B. , BHANSALI VINEER
Published: September 2004

The capital structure of a firm is composed of equity and debt. In the Merton approach, equity holders hold a call option on the firm value, while bond holders are short a put on the firm value. Dividends paid to holders of equity provide them with current cash flow. The pay out of dividends to the equity holders devalues a firms debt since it increases its probability of default. With dividend yields at multi-decade lows it seems likely then that in the future some companies that do not currently issue dividends will begin paying dividends and some companies that currently only pay a small dividend will increase their dividend yield. Hence holders of the bonds for a firm that does not presently pay dividends (or pays a small dividend) have "dividend risk" associated with the possibility that at some time in the future the company will start issuing dividends to its stock holders (or increase its dividend rate if it currently pays a small dividend). In this paper we explore the consequences of future dividend increases for bond prices and default probabilities.
ADAPTIVE FINITE ELEMENT METHODS FOR LOCAL VOLATILITY EUROPEAN OPTION PRICING
Authors: ERN ALEXANDRE , VILLENEUVE STÉPHANE , ZANETTE ANTONINO
Published: September 2004

We investigate finite element discretizations using functions that are discontinuous in time and continuous in space for European options with local volatility Black–Scholes models. We present an a posteriori error estimate where a user-specified functional of the error is controlled by the inner product of the finite element residual with the solution of a dual problem that involves the density of the target functional as prescribed data. Examples of error functionals are discussed in the context of either option pricing or volatility calibration from market data. The a posteriori error estimator is then localized onto the space-time cells of the computational mesh and implemented in the framework of an adaptive mesh refinement/derefinement algorithm which provides some form of optimal compromise between accuracy requirements and computational costs. Numerical examples illustrate the efficiency of the proposed methodology.
Cholesterol diet enhances daily rhythm of Pai-1 mRNA in the mouse liver
Authors: Kudo Takashi , Nakayama Emiko , Suzuki Sawako , Akiyama Masashi , Shibata Shigenobu
Published: September 2004

Myocardial infarction frequently occurs in the morning, a phenomenon in part resulting from the downregulation of fibrinolytic activity. Plasminogen activator inhibitor-1 (PAI-1) is a key factor behind fibrinolytic activity, and its gene expression is controlled under the circadian clock gene in the mouse heart and liver. Hypercholesterolemia has been associated with impaired fibrinolysis due to enhanced PAI-1 activity, which has also been implicated in atherosclerosis. The aim of this study was to decipher whether the Pai-1 gene is still expressed daily with hypercholesterolemia. Hypercholesterolemia (1% cholesterol diet) did not significantly affect the daily expression of clock genes ( Per2 and Bmal1) and clock-controlled genes ( Dbp and E4bp4) in the liver ( P > 0.05); however, daily expression of the Pai-1 gene and Pai-1 promoter regulating factor genes such as Nr4a1 was significantly upregulated ( P < 0.01). Daily restricted feeding for 4 h during the day reset the gene expression of Per2, Pai-1, Nr4a1, and Tnf-α. Lesion of the suprachiasmatic nucleus, the location of the main clock system, led to loss of Per2 and Pai-1 daily expression profiles. In the present experiments, we demonstrated that hypercholesterolemia enhanced daily expression of the Pai-1, Tnf-α, and Nr4a1 genes in the mouse liver without affecting clock and clock-controlled genes. Therefore, the risk or high frequency of acute atherothrombotic events in the morning still seems to be a factor that may be augmented under conditions of hypercholesterolemia.
Mechanics and hemodynamics of esophageal varices during peristaltic contraction
Authors: Miller Larry S. , Kim Joseph K. , Dai Qing , Mekapati Jyothi , Izanec James , Chung Chan , Liu Ji-Bin , Sanderson Andrew , Bohning Matt , Desipio Josh , Gandegok Jasneet , Harberson Justin J. , Schneck Carson , Nicosia Mark A. , Thangada Vinod , Thomas Beje , Copeland Brian , Miller Elan , Miller Aaron , Ahmed Naji , Brasseur James G.
Published: September 2004

Our hypothesis states that variceal pressure and wall tension increase dramatically during esophageal peristaltic contractions. This increase in pressure and wall tension is a natural consequence of the anatomy and physiology of the esophagus and of the esophageal venous plexus. The purpose of this study was to evaluate variceal hemodynamics during peristaltic contraction. A simultaneous ultrasound probe and manometry catheter was placed in the distal esophagus in nine patients with esophageal varices. Simultaneous esophageal luminal pressure and ultrasound images of varices were recorded during peristaltic contraction. Maximum variceal cross-sectional area and esophageal luminal pressures at which the varix flattened, closed, and opened were measured. The esophageal lumen pressure equals the intravariceal pressure at variceal flattening due to force balance laws. The mean flattening pressures (40.11 ± 16.77 mmHg) were significantly higher than the mean opening pressures (11.56 ± 25.56 mmHg) ( P ≤ 0.0001). Flattening pressures >80 mmHg were generated during peristaltic contractions in 15.5% of the swallows. Variceal cross-sectional area increased a mean of 41% above baseline (range 7–89%, P < 0.0001) during swallowing. The peak closing pressures in patients that experience future variceal bleeding were significantly higher than the peak closing pressures in patients that did not experience variceal bleeding ( P < 0.04). Patients with a mean peak closing pressure >61 mmHg were more likely to bleed. In this study, accuracy of predicting future variceal bleeding, based on these criteria, was 100%. Variceal models were developed, and it was demonstrated that during peristaltic contraction there was a significant increase in intravariceal pressure over baseline intravariceal pressure and that the peak intravariceal pressures were directly proportional to the resistance at the gastroesophageal junction. In conclusion, esophageal peristalsis in combination with high resistance to blood flow through the gastroesophageal junction leads to distension of the esophageal varices and an increase in intravariceal pressure and wall tension.
Effect of lower esophageal sphincter tone and crural diaphragm contraction on distensibility of the gastroesophageal junction in humans
Authors: Shaker Reza , Bardan Eytan , Gu Chengming , Massey Benson T. , Sanders Thomas , Kern Mark K. , Hoffmann Raymond G. , Hogan Walter J.
Published: September 2004

Previous studies of distensibility of the gastroesophageal junction (GEJ) in humans have not tried to distinguish between the effects of muscle action and passive elastic tissue properties of the GEJ. We studied 15 healthy subjects (ages 23–67 yr, 11 men/4 women) by using a catheter with a highly complaint bag positioned manometrically at the GEJ. The bag was distended with air at a rate of 20 ml/min while intrabag pressure was recorded. Distensions were performed during normal breathing, with breath held at maximum inspiration (MI) to activate the diaphragmatic crura, and with midesophageal balloon distension (BD) to relax the lower esophageal sphincter. In 10 subjects, distensions were performed after atropine injection (12 μg/kg iv). Pressure-volume curves and incremental distensibility values were calculated and compared among the different conditions. Both MI and BD significantly altered the slopes of the pressure-volume curves, whereas no effect was seen with atropine. Maximum distensibility was seen at the volume increment of 5–10 ml and was reduced with larger volumes. Distensibility measurements for the various test conditions tended to converge at the largest volume increment, suggesting that distensibility at this degree of distension was more related to the passive elastic properties of the GEJ. On the basis of these findings, we conclude that there can be significant active muscular contributions to recordings of distensibility at the GEJ, variations that must be controlled for during different study conditions.
Differential subcellular targeting of PKC-ε in response to pharmacological or ischemic stimuli in intestinal epithelia
Authors: Mammen Joshua M. V. , Song J. Cecilia , Yoo James , Kim Peter S. , Davis Harold W. , Calvo M. Isabel , Worrell Roger T. , Matlin Karl S. , Matthews Jeffrey B.
Published: September 2004

Ischemia is the central pathogenic factor underlying a spectrum of intestinal disorders. The study of the cellular signaling responses to ischemic stress in nonepithelial cells has progressed substantially in the previous several years, but little is known about the response in epithelial cells. Unique features of the epithelial response to ischemic stress suggest differential regulation with regards to signaling. The PKC family of proteins has been implicated in ischemic stress in nonepithelial systems. The role of PKC isoforms in chemical ischemia in intestinal epithelial cells is evaluated in this study. Additionally, the phosphorylation of the F-actin cross-linking protein myristoylated alanine-rich C kinase substrate (MARCKS) is also studied. Chemical ischemia resulted in the transient activation of only the isoform PKC-ε as detected by translocation employing the subcellular fractionation technique. The pharmacological agonists phorbol 12-myristate 13-acetate and carbachol also led to the translocation of PKC-ε. By immunofluoresence, MARCKS is noted to be located at the lateral membrane under control conditions. In response to carbachol, MARCKS translocates to the cytosol, indicating its phosphorylation, which is additionally confirmed biochemically. Consistent with this observation, carbachol induces the translocation of PKC-ε to proximity with MARCKS at the lateral membrane. In response to chemical ischemia, MARCKS fails to translocate and phosphorylation does not increase. Additionally, the translocation of PKC-ε is not to the lateral membrane but rather basally. The data suggest that the differential translocation of PKC-ε in response to pharmacological agonists versus ischemic stress may lead to different effects on downstream targets.