bluuebunny/crossref_metadata_2025 huggingface dataset:
Biofiltration of Butyl Acetate and Xylene Mixtures Using a Trickle‐Bed Air Biofilter
Authors: Lu C. , Chang K.
Published: April 2004

Butyl acetate and xylene mixtures are commonly encountered from the manufacture of semi‐conductor or opto‐electronic apparatuses. The release of these substances into the ambient air may have a negative effect on the air quality. This study attempts to employ a trickle‐bed air biofilter for treating butyl acetate and xylene mixtures under different gas flow rates and influent concentrations. Almost complete VOC removal could be attained with influent carbon loadings of BA (butyl acetate) and X (xylene) below 40 and 15 g/m3h, respectively. As the influent carbon loadings of BA and X were increased up to 150 and 110 g/m3h, removal efficiencies higher than 80 % were achieved. Therefore, the trickle‐bed air biofilter (TBAB) appeared efficient in the control of emissions containing mixtures of butyl acetate and xylene with low to medium carbon loadings. The removal efficiencies of butyl acetate were higher than those of xylene, indicating that butyl acetate was the substrate preferred in the utilization of butyl acetate and xylene mixtures by the microorganisms. Carbon recoveries of 98–101 % were achieved, demonstrating the accuracy of results. The carbon mass rate of the liquid effluent was approximately two to three orders of magnitude less than that of the CO2 effluent, indicating that the dissolved VOCs and their derivatives in the leachate were present in a negligible amount in the reactor. Applicable operating conditions of the TBAB unit for treating BA and X mixtures were suggested.
Aeolian modification of moraine soils, Whiskey Basin, Wyoming, USA
Authors: Applegarth Michael T. , Dahms Dennis E.
Published: April 2004

Soils along catenas of Pinedale (15–20 ka) and Bull Lake (100–130 ka) age moraines at Whiskey Basin in the Wind River Range, Wyoming, USA, were sampled to assess the effects of aeolian processes on soil development here. Aeolian processes appear to have inﬂuenced soils by both depositing sediments and eroding topsoils. Pedogenic silt (often used as an indicator of wind deposition) accumulated in the Bull Lake soils moderately correlate with pedogenic clay accumulated, suggesting that ﬁne sediments may have been deposited and incorporated into soil formation here. Following removal of previous topsoil by wind during Pinedale glaciation, Bull Lake B horizons have developed into contemporary A horizons. These data further link aeolian processes to soil development on piedmont moraines throughout the Wind River Range. Copyright © 2004 John Wiley & Sons, Ltd.
A hillslope hydrology approach for catchment‐scale slope stability analysis
Authors: Hennrich Kirsten , Crozier Michael J.
Published: April 2004

Regional analysis of slope stability is often constrained by availability of data. Model requirements for input data cannot be met at the desired spatial resolution because data are either site‐speciﬁc or non‐existent. Faced with these difﬁculties it has often been the practice to assume that certain parameters are uniform throughout the area of interest. An alternative approach proposed here allows a more detailed discrimination of slope stability conditions. Based on the principles of hillslope hydrology, hydrologic information can be generated at sufﬁcient resolution to allow higher resolution slope stability analysis. Measurements from an instrumented network in a small area have been used to establish index‐based models for topographic and climate‐related controls of piezometric response. The ability to relate groundwater levels to rainfall and topographic parameters provides a means of up‐scaling to larger catchments and ultimately the opportunity to generate a catchment‐wide prediction of the distribution, magnitude and frequency of rainstorm‐generated groundwater levels. The example provided in this study uses the topography index of TOPMODEL in GIS to predict the spatial patterns of groundwater elevation for seasonal soil moisture conditions and given rainfall inputs. This allows modelling of catchment‐wide response of soil water to rainstorms with different return periods (representing different magnitudes), and is an essential prerequisite for a probabilistic regional slope stability analysis. Copyright © 2004 John Wiley & Sons, Ltd.
System capacity with smart antennas under the presence of angular power spread
Authors: Muñoz‐Rodríguez David , Orozco Edgar , Vargas Cesar , Rodríguez‐Cruz José Ramón , Donis Gerardo
Published: April 2004

Smart antennas are a suitable technology to increase the capacity of cellular systems. However, under severe channel conditions, the capacity gain may be small. This work presents a general methodology for the analysis of the effect of the angular power dispersion on the capacity gain for a CDMA system when using smart antennas. System capacity is expressed in terms of a supportable mean number of subscribers per angular sector and it is shown that maximum and mean number of subscribers criteria can be considered equivalent. Formulations for a single cell as well as for multi‐tier scenarios are presented. Omni‐directional case and non‐spread scenarios are shown to be particular cases of the methodology introduced. Capacity is determined for a smart antenna system, both for general antenna beam patterns and general spread characteristics. Copyright © 2004 AEI
In‐band coding technique to promptly enhance SDH/SONET fiber‐optic channels with FEC capabilities
Authors: Tychopoulos Afxendios , Koufopavlou Odysseas
Published: April 2004

In the present paper, we discuss FEC‐methods for SDH/SONET networks under the perspective of DWDM. The lightwave channels are assumed to have a burst‐error character. First, a FEC‐strategy is outlined by means of fundamental performance criteria. The SDH/SONET frame‐overhead is also explored for possible allocation of error‐correction bits inside. Then, different FEC methods are rated by the above criteria in a systematic manner. We eventually propose a section‐ and line‐layer, in‐band coding (IBC) approach that should deal with a very wide range of optical network applications in a straightforward, uniform and effective fashion. Comparison with past work on this subject reveals clear advantages. Extensive simulations, implementation and laboratory measurements prove the feasibility and efficiency of the proposed FEC method with RS(244,240,9), provided that a portion of the SDH/SONET overhead is available. Copyright © 2004 AEI
A new mutual authentication and key exchange protocol with balanced computational power for wireless settings
Authors: Yang Chou‐Chen , Li Jian‐Wei , Hwang Min‐Shiang
Published: April 2004

Mutual authentication and key exchange protocols (MAKEP) provide two parties in communication with guarantee of true identity. And then the two parties end up sharing a common session key for privacy and data integrity during the session. In MAKEP, public‐key‐based schemes and symmetric‐key‐based schemes are often used. However, the former requires high computation complexity and hence, it is not suitable for applications in wireless settings. The latter has to maintain many distinct keys for different parties. Wong et al. proposed the Linear MAKEP to solve these problems. But in term of storage space, it is not optimal. In this paper, we propose a scheme that uses the geometric properties of line to achieve mutual authentication and key exchange. Compared with Wong et al.'s scheme, our scheme is efficient and requires less storage space. It can withstand the replay attack and the unknown key‐share attack, and the server does not bear much more computation cost than the client in each session, hence we call it a protocal with balanced computational power. Copyright © 2004 AEI
Construction, analysis and performance of generalised woven codes
Authors: Bossert Martin , Dieterich Hans , Schnug Walter , Shavgulidze Sergo
Published: April 2004

Generalised woven codes (WC) are constructed by combining the woven code structure with the idea of generalised concatenated codes, also known as multi‐level codes. The required nested inner convolutional code is analysed. The encoder structure of this new class of codes is described and fundamental code parameters are derived. It is shown that generalised WC have a free distance which is superior to that of comparable WC. Several iterative and non‐iterative decoding strategies are discussed. It is shown that the decoding complexity of the nested inner code is not larger than the decoding complexity of its mother code. Finally, bit error rates obtained from simulations are discussed and compared with other code structures like WC. Copyright © 2004 AEI
Performance analysis of integrated voice and multiple classes of data with a finite number of sessions
Authors: Mahdavi M. , Edwards R. M. , Ivey P.
Published: April 2004

This paper discusses a TDM multi‐access channel that supports hybrid switching including circuit switched voice and packet switched data asKCclasses with a finite number of open sessions. The channel is partitioned intoKCsub‐channels that are assigned to classes. Applications are hybrid switching in mobile TDMA (e.g. GSM/GPRS cellular networks) and time division multiplexing systems. Herein, an original analysis for such mixed services is derived. In this paper, a new Markov model for voice traffic in each sub‐channel is shown. The system is modelled with an irreducible continuous time and aperiodic Markov process and a non‐homogenous finite QBD process based on macrostructure model of TDM channel is derived. A novel computational algorithm is then formulated. Using the computational algorithm, performance metrics of the system such as mean delay in the queue as well as average number of data users in queue will be obtained. QoS is defined and the advantage of channel sharing is highlighted. Numerical results are corroborated by simulation. Copyright © 2004 AEI
Hybrid location systems: delivering non‐standardized assistance data in GSM/GPRS networks
Authors: Martin‐Escalona Israel , Barceló Francisco , Paradells Josep
Published: April 2004

Hybrid location systems overcome some of the limitations of location techniques when they are used as standalone. Coverage and accuracy improve when hybridization is carried out by combining time measurements prior to determining location co‐ordinates, rather than mixing position co‐ordinates. However, for the best performance, certain hybridization methods need to transmit assistance data that are not included in current location protocols and standards. This assistance information includes data that may be used to synchronize the different positioning systems for hybridization. This study introduces two proposals that allow the required assistance information to be delivered from the network to the terminal without changing the existing standards. Both proposals are discussed in detail and compared. Copyright © 2004 AEI
Perceptual Evaluation of JPEG2000
Authors: Samet Amine , Ben Ayed Mohamed Ali , Loulou Mourad , Masmoudi Nouri
Published: April 2004

With the increasing usage of multimedia technologies, image compression requires higher performances as well as new features. To address these needs in the specific area of continuous tone still image encoding, a new standard is currently being developed, the JPEG2000. It is not only intended to provide rate‐distortion and subjective image quality performance superior to existing standards, but also to provide new features and functionalities that current standards can either not address them efficiently or in many cases cannot address them at all. Copyright © 2004 AEI
Numerical simulations of large falling drops
Authors: Gottesdiener Louis , Gueyffier Denis , Abdelouahab Mohammed , Gatignol Renée , Zaleski Stéphane
Published: April 2004

The numerical simulation in a two‐phase medium of falling drops allows their velocities and shapes during the fall to be calculated. The terminal velocities and shapes for bromoform and chlorobenzene drops falling into water have been obtained. Although the method used calculates the flow inside and around the drop, it has not been possible to give results independent of the spatial discretization and the boundary effects. However, taking these influences into account, the numerical results agree with the experimental data given and the study consists of a good validation of the SURFER code used. Copyright © 2004 John Wiley & Sons, Ltd.
A projection scheme for incompressible multiphase flow using adaptive Eulerian grid
Authors: Chen T. , Minev P. D. , Nandakumar K.
Published: April 2004

This paper presents a finite element method for incompressible multiphase flows with capillary interfaces based on a (formally) second‐order projection scheme. The discretization is on a fixed Eulerian grid. The fluid phases are identified and advected using a level set function. The grid is temporarily adapted around the interfaces in order to maintain optimal interpolations accounting for the pressure jump and the discontinuity of the normal velocity derivatives. The least‐squares method for computing the curvature is used, combined with piecewise linear approximation to the interface. The time integration is based on a formally second order splitting scheme. The convection substep is integrated over an Eulerian grid using an explicit scheme. The remaining generalized Stokes problem is solved by means of a formally second order pressure‐stabilized projection scheme. The pressure boundary condition on the free interface is imposed in a strong form (pointwise) at the pressure‐computation substep. This allows capturing significant pressure jumps across the interface without creating spurious instabilities. This method is simple and efficient, as demonstrated by the numerical experiments on a wide range of free‐surface problems. Copyright © 2004 John Wiley & Sons, Ltd.
Mesh adaptation as a tool for certified computational aerodynamics
Authors: Schall E. , Leservoisier D. , Dervieux A. , Koobus B.
Published: April 2004

Mesh convergence order is a key for certification of the accuracy of numerical solutions. A few available results and tools in mesh adaption are synthetized in order to specify a mesh converging method for adaptive calculation of compressible flows including shocks or viscous layers. The main design property for this method is early second‐order convergence, where early means that the second‐order convergence is obtained with coarse meshes. Copyright © 2004 John Wiley & Sons, Ltd.
A projection method for solving incompressible viscous flows on domains with moving boundaries
Authors: Pan Hua , Pan Lun Sheng , Xu Diao , Ng Teng Yong , Liu Gui Rong
Published: April 2004

In this paper, a projection method is presented for solving the flow problems in domains with moving boundaries. In order to track the movement of the domain boundaries, arbitrary‐Lagrangian–Eulerian (ALE) co‐ordinates are used. The unsteady incompressible Navier–Stokes equations on the ALE co‐ordinates are solved by using a projection method developed in this paper. This projection method is based on the Bell's Godunov‐projection method. However, substantial changes are made so that this algorithm is capable of solving the ALE form of incompressible Navier–Stokes equations. Multi‐block structured grids are used to discretize the flow domains. The grid velocity is not explicitly computed; instead the volume change is used to account for the effect of grid movement. A new method is also proposed to compute the freestream capturing metrics so that the geometric conservation law (GCL) can be satisfied exactly in this algorithm. This projection method is also parallelized so that the state of the art high performance computers can be used to match the computation cost associated with the moving grid calculations. Several test cases are solved to verify the performance of this moving‐grid projection method. Copyright © 2004 John Wiley Sons, Ltd.
An accurate moving grid Eulerian Lagrangian localized adjoint method for solving the one‐dimensional variable‐coefficient ADE
Authors: Younes Anis
Published: April 2004

An accurate finite‐volume Eulerian Lagrangian localized adjoint method (ELLAM) is presented for solving the one‐dimensional variable coefficients advection dispersion equation that governs transport of solute in porous medium. The method uses a moving grid to define the solution and test functions. Consequently, the need for spatial interpolation, or equivalently numerical integration, which is a major issue in conventional ELLAM formulations, is avoided.

After reviewing the one‐dimensional method of ELLAM, we present our strategy and detailed calculations for both saturated and unsaturated porous medium. Numerical results for a constant‐coefficient problem and a variable‐coefficient problem are very close to analytical and fine‐grid solutions, respectively. The strength of the developed method is shown for a large range of CFL and grid Peclet numbers. Copyright 2004 John Wiley & Sons, Ltd.
Numerical approximation of optimal control of unsteady flows using SQP and time decomposition
Authors: Ravindran S. S.
Published: April 2004

In this paper, we present numerical approximations of optimal control of unsteady flow problems using sequential quadratic programming method (SQP) and time domain decomposition. The SQP method is considered superior due to its fast convergence and its ability to take advantage of existing numerical techniques for fluid flow problems. It iteratively solves a sequence of linear quadratic optimal control problems converging to the solution of the non‐linear optimal control problem. The solution to the linear quadratic problem is characterized by the Karush–Kuhn–Tucker (KKT) optimality system which in the present context is a formidable system to solve. As a remedy various time domain decompositions, inexact SQP implementations and block iterative methods to solve the KKT systems are examined. Numerical results are presented showing the efficiency and feasibility of the algorithms. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of low‐zinc status and essential fatty acids deficiency on the activities of aspartate aminotransferase and alanine aminotransferase in liver and serum of albino rats
Authors: Ajayi Olubunmi Bolanle , Odutuga Adewale
Published: April 2004

The effects of dietary deficiencies of zinc and essential fatty acids (EFAs) or both on aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were investigated in young growing rats. Four groups of albino rats were fed diets deficient in either EFA (4% hydrogenated coconut oil) or zinc (6 ppm) or both. The control diet was adequate in EFA (4% soybean oil) and zinc (100 ppm). The feeding trial lasted eight weeks and the activities of AST and ALT were determined in the liver and serum. EFA deficiency had no significant (p > 0.05) effect on liver AST. However, zinc and the double deficiencies depressed AST activity in the organ. Deficiencies of EFA, zinc and their combination depressed ALT activity in the liver significantly (p < 0.05) with a concomitant increase recorded in the serum. The data suggested alteration in endothelial permeability of the plasma membrane and thus leakage of membrane constituents in the tissue studied. It is therefore considered that these deficient diets may affect liver tissue negatively in view of the role of these enzymes in amino acid metabolism.
Nutritional value of broad bean seeds. Part 3: Changes of dietary fibre and starch in the production of commercial flours
Authors: Giczewska Anna , Borowska Julitta
Published: April 2004

We report on the impact of flour production from small‐ and large‐seed varieties of broad bean on the quantitative and qualitative distribution of dietary fibre and starch. The experimental material consisted of the seeds of small‐seed varieties of broad bean: Gobik and Goral, large‐seed varieties of broad bean: Windsor Bialy and Bartom, and pea seeds of Albatros, Karat and Miko varieties (for comparison). The seeds were at full physiological maturity. Soaking and hydrothermal processing were shown to cause multidirectional, statistically significant changes in dietary fibre and starch, depending on both parameters of the process and type of the seeds. The flours of both small‐seed broad bean varieties contained 20.15%–28.31%, flours of the large‐seed broad bean 23.10%–27.50%, and those from pea seeds 20.13%–22.81% total dietary fibre. Attention should be paid to the considerable, approximately 2‐fold increase in the soluble dietary fibre (SDF) content, compared to the raw material. The processing of seeds caused significant changes also with reference to starch. The most considerable changes were observed when the variant with the longest times of soaking (18 h) and heating (45 min) was applied. In the broad bean flours, the content of analytically available starch decreased by 22.94–30.60% and its digestibility was observed to decrease up to 30.25%. The pea flours, however, were characterised by an increased concentration of both forms of starch, especially significant for the digestible starch. The calculated content of resistant starch (RS) differentiated, to a high extent, the flours obtained. Under the same processing conditions, the flours of small‐seed Gobik and Goral varieties of broad bean were characterised by a significantly higher RS content than those obtained from the large‐seed varieties. A decrease in the starch digestibility rate index (SDRI) values, especially high for the small‐seed varieties, should also be emphasised. The results obtained indicate that the nutritional value of flours can be determined by controlled processing parameters.
Effect of acetylation and succinylation on solubility profile, water absorption capacity, oil absorption capacity and emulsifying properties of mucuna bean (Mucuna pruriens) protein concentrate
Authors: Lawal O. S. , Adebowale K. O.
Published: April 2004

Mucuna protein concentrate was acylated with succinic and acetic anhydride. The effects of acylation on solubility, water absorption capacity, oil absorption capacity and emulsifying properties were investigated. The pH‐dependent solubility profile of unmodified mucuna protein concentrate (U‐mpc) showed a decrease in solubility with decrease in pH and resolubilisation at pH values acidic to isoelectric pH (pH 4). Apart from pH 2, both acetylated mucuna protein concentrates (A‐mpc) and succinylated mucuna protein concentrate (S‐mpc) had improved solubility over the unmodified derivative. Acylation increased the water absorption capacity (WAC) at all levels of ionic strength (0.1–1.0 M). WAC of the protein samples increased with increase in ionic strength up to 0.2 M after which a decline occurred with increase in ionic strength from 0.4–1.0 M. When protein solutions were prepared in salts of various ions, increase in WAC followed the Hofmeister series in the order: NaSCN < NaClO4 < NaI < NaBr < NaCl < Na2SO. Acetylation improved the oil absorption capacity while the lipophilic tendency reduced the following succinylation. Emulsifying capacity increased with increase in concentration up to 2, 4 and 5% w/v for U‐mpc, A‐mpc and S‐mpc, respectively, after which an increase in concentration reduced the emulsifying capacity. Both acetylation and succinylation significantly (P < 0.05) improved the emulsifying capacity at pH 4–10. Initial increase in ionic strength up to 0.4 M for U‐mpc and 0.4 M for A‐mpc and S‐mpc increased the emulsion capacity progressively. Further increase in ionic strength reduced emulsion capacity (EC). Contrary to the effect of various salts on WAC, increase in EC generally follows the series Na2SO4 < NaCl < NaBr < NaI < NaClO4 < NaSCN. At all levels of ionic strength studied, S‐mpc had a better emulsifying activity (EA) than both A‐mpc and U‐mpc. EA and emulsifying stability (ES) were pH‐dependent. Maximum EA and ES were recorded at pH 10. ES of protein derivatives were higher than those of U‐mpc in the range of pH 4–10 but lower at pH 2. Studies revealed that both A‐mpc and S‐mpc had better ES and EA than the unmodified derivative when protein solutions were prepared in salts of various anions.
Mode of action of lactococcin R produced by Lactococcus lactis R
Authors: Yıldırım Zeliha , Yıldırım Metin , Johnson Michael G.
Published: April 2004

We investigated the mode of action and factors affecting adsorption of lactoccocin R produced by Lactococcus lactis R. It was found that lactococcin R adsorbed to all Gram‐positive but not to the Gram‐negative bacteria tested and its adsorption was dependent on pH. It was observed that the binding of lactococcin R was prevented by anions of several salts (Cl–, PO4–3) and lipoteichoic acid. Pretreatments of sensitive cells and cell walls with detergents, organic solvents or enzymes did not reduce subsequent binding of lactococcin R. However, treatment of cell wall preparations with methanol:chloroform and hot 20% trichloroacetic acid (TCA) caused such walls to lose their ability to adsorb lactococcin R. Sensitive cells treated with lactococcin R lost high amounts of intracellular K+ ions, UV‐absorbing materials and became more permeable to o‐nitrophenol‐β‐D‐glactopyranoside (ONPG). In addition, different lactococcin R concentrations (0–2560 AU/mL) decreased the colony counts of Listeria monocytogenes by 99% and also a reduction in the absorbance values. These results show that the mode of action of lactococcin R is bactericidal rather than bacteriostatic.
Usage of enzymes in a novel baking process
Authors: Keskin Semin Özge , Sumnu Gülüm , Sahin Serpil
Published: April 2004

In this study, the effects of different enzymes (α‐amylase, xylanase, lipase, protease) on quality of breads baked in different ovens (microwave, halogen lamp‐microwave combination and conventional oven) were investigated. It was also aimed to reduce the quality problems of breads baked in microwave ovens with the usage of enzymes. As a control, bread dough containing no enzyme was used. Specific volume, firmness and color of the breads were measured as quality parameters. All of the enzymes were found to be effective in reducing the initial firmness and increasing the specific volume of breads baked in microwave and halogen lamp‐microwave combination ovens. However, in conventional baking, the effects of enzymes on crumb firmness were seen mostly during storage. The color of protease enzyme added breads were found to be significantly different from that of the no enzyme and the other enzyme added breads in the case of all type of ovens.
Ageing and health‐care expenditure: the red herring argument revisited
Authors: Seshamani Meena , Gray Alastair
Published: April 2004

Zweifel and colleagues have previously proposed that proximity to death is a more important influence on health‐care costs than age, suggesting that demographic change per se will not have a large impact on future aggregate health expenditure. However, issues of econometric methodology have led to challenges of the robustness of these findings. This paper revisits the analysis. Using a longitudinal hospital data set from Oxfordshire, England, the two‐step Heckman model from the Zweifel study is first replicated, to find that neither age nor proximity to death have a significant effect on hospital costs. Econometric problems with the model are demonstrated, and instead a two‐part model shows both age and proximity to death to have significant effects on quarterly hospital costs. Cost predictions, calculated with bootstrapped 95% confidence intervals, further demonstrate that while age may significantly affect quarterly costs, these cost changes are small compared to the tripling of quarterly costs that occurs with approaching death in the last year of life. The analyses show the importance of model selection to properly assess the determinants of health‐care expenditures. Copyright © 2003 John Wiley & Sons, Ltd.
Quality safeguards and regulation of online pharmacies
Authors: Arruñada Benito
Published: April 2004

Using econometric evidence, this article confirms that distribution of medicines online is split into two market segments of very diverse quality, and identifies the factors that drive quality and quality assurance in this activity. Unlike fraudulent, ‘rogue,’ websites, which offer scant guarantees and usually sell just a few medicines without prescription, online pharmacies offering insurance coverage and linked to conventional pharmacies typically sell a whole range of drugs, require third‐party medical prescriptions and provide abundant information to patients. It is shown that, where online pharmacies are allowed to act legally, market forces enhance quality, as private insurers require professional standards, and specialized third parties make a business of certifying them. Furthermore, older online pharmacies and those running conventional operations offer higher quality, probably because of reputational investments. Overall, this evidence supports licensing online pharmacies, especially considering that prohibiting them is ineffective against fraudulent sites. Copyright © 2003 John Wiley & Sons, Ltd.
Time to include time to death? The future of health care expenditure predictions
Authors: Stearns Sally C. , Norton Edward C.
Published: April 2004

Government projections of future health care expenditures – a great concern given the aging baby‐boom generation – are based on econometric regressions that control explicitly for age but do not control for end‐of‐life expenditures. Because expenditures increase dramatically on average at the end of life, predictions of future cost distributions based on regressions that omit time to death as an explanatory variable will be biased upward (or, more explicitly, the coefficients on age will be biased upward) if technology or other social factors continue to prolong life. Although health care expenditure predictions for a current sample will not be biased, predictions for future cohorts with greater longevity will be biased upwards, and the magnitude of the bias will increase as the expected longevity increases. We explore the empirical implications of incorporating time to death in
longitudinal models of health expenditures for the purpose of predicting future expenditures. Predictions from a simple model that excludes time to death and uses current life tables are 9% higher than from an expanded model controlling for time to death. The bias increases to 15% when using projected life tables for 2020. The predicted differences between the models are sufficient to justify reassessment of the value of inclusion of time to death in models for predicting health care expenditures. Copyright © 2003 John Wiley & Sons, Ltd.
A comparison of the grade of membership measure with alternative health indicators in explaining costs for older people
Authors: McNamee Paul
Published: April 2004

An important focus in empirical econometric studies of health care concerns estimation of the relationship with health. This paper describes a non‐parametric technique, the grade of membership (GoM) procedure, which is used to construct summary indicators of health. Health status is also assessed using three alternative measures commonly employed in the literature: an index of problems of activities of daily living (ADL), an index of health conditions and overall self‐rated health. Using data from a sample of frail older people, the relationship between costs and different measures of health are estimated using ordinary least squares (OLS) and instrumental variables (IV) methods. The results show that health influences costs more strongly than other variables, an effect which persists after controlling for potential endogeneity. It is shown that health can be usefully classified using GoM techniques. An alternative measure, based on an index of ADL, also performs well. Measures based on overall self‐assessed health and the number of health conditions present were less satisfactory. Although health indicators derived from GoM techniques may be more theoretically attractive, in terms of capturing more fully the multidimensional nature of health, simpler alternatives such as those based on ADL indices may offer practical computational advantages. Copyright © 2003 John Wiley & Sons, Ltd.
Predictors of elderly mortality:health status, socioeconomic characteristics and social determinants of health
Authors: Mete Cem
Published: April 2004

This paper uses longitudinal survey data from Taiwan to investigate the predictors of elderly mortality. The empirical analysis confirms a relationship between socioeconomic characteristics and mortality, but this relationship weakens considerably when estimates are conditional on the health status at the time of the first wave survey. In terms of predictive power, the models with an activities of daily living index fare better (as opposed to models with self‐evaluated health or self‐reported illnesses). Having said that there is a payoff to the consideration of self‐evaluated health jointly with other ‘objective’ health indicators. Other findings include a strong association between life satisfaction and survival, which prevails even after controlling for other explanatory variables. Copyright © 2004 John Wiley & Sons, Ltd.
Cost‐effectiveness with multiple outcomes
Authors: Bjørner Jakob , Keiding Hans
Published: April 2004

In a large number of situations, activities in health care have to be measured in terms of outcome and cost. However, the cases where outcome is fully captured by a single measure are rather few, so that one uses some index for outcome, computed by weighing together several outcome measures using subjective and somewhat arbitrary weights. In the paper we propose an approach to cost‐effectiveness analysis where such artificial aggregation is avoided. This is achieved by assigning to each activity the weights which are the most favourable in a comparison with the other options available, so that activities which have a poor score in this method are guaranteed to be inferior. The method corresponds to applying Data envelopment analysis, known from the theory of productivity, to the context of health economic evaluations.

The method is applied to an analysis of the cost‐effectiveness of alternative health plans using data from the Medical Outcome Study (JAMA 1996; 276: 1039–1047), where outcome is measured as improvement in mental and physical health. Copyright © 2004 John Wiley & Sons, Ltd.
Change in longitudinal profile on three North Cascades glaciers during the last 100 years
Authors: Pelto Mauri S. , Hartzell Paula
Published: April 2004

Centreline surface elevation longitudinal profiles have been completed for three different points in time from historic photographs (∼1900), US Geological Survey maps (1964 and 1985), and field measurements (annually between 1984 and the present) for three North Cascade glaciers. Comparison of thinning and terminus behaviour over this time period indicates substantial overall volume loss during this century for each glacier.

Mean thickness changes along the longitudinal profile of Easton Glacier are losses of 46 m (0·68 m year−1) of ice thickness between 1916 and 1984 and 13 m (0·72 m year−1) between 1984 and 2002. Its terminus has retreated a net distance of 2123 m. Lower Curtis Glacier lost an average of 45 m (0·60 m year−1) thickness from 1908 to 1984 and 6 m (0·33 m year−1) from 1984 to 2002, with a net terminus retreat of 522 m. On Columbia Glacier, ice thickness loss was 57 m (0·78 m year−1) from 1911 to 1984 and 8 m (0·44 m year−1) from 1984 to 2002. The net terminus retreat for Columbia was 640 m. Thickness changes are approximately equal in the accumulation zone of the Columbia and Lower Curtis Glacier during the 20th century and from 1984 to 2002. This suggests that there is no position to which the glacier can retreat and achieve equilibrium.

The changes on each glacier, which today average less than 75 m in thickness, represent the loss of 35–50% in their volume since the turn of the century, and 10–15% of this volume since 1984. Their ongoing thinning indicates that these three glaciers will continue to retreat in the foreseeable future, the Columbia Glacier likely disappearing. Long‐term monitoring of these glaciers should continue in order to assess the impact on downstream flow, which is utilized for hydropower on Easton and Lower Curtis Glaciers and a salmon hatchery on Columbia Glacier. Copyright © 2004 John Wiley & Sons, Ltd.
Evaluation of the snow cover variation in the Canadian Regional Climate Model over eastern Canada using passive microwave satellite data
Authors: Langlois A. , Royer A. , Fillol E. , Frigon A. , Laprise R.
Published: April 2004

Snow cover from a 3 year (1992/93–1994/95) simulation of the Canadian Regional Climate Model (CRCM; operational version 3·5·3) driven by National Centers for Environmental Prediction analysis data over eastern Canada was evaluated using passive‐microwave‐derived snow cover information from the daily Special Sensor Microwave/Imager (SSM/I) data. The presence of snow on the ground was derived from 19 and 37 GHz normalized difference brightness temperature series to which a low‐pass filter was applied to remove day‐to‐day noise, and thresholding was also applied at different levels for taking into account the variation in vegetation density. The thresholds calibrated for four density classes with surface observations show a mean residual underestimation in the SSM/I number of days with snow cover during seasonal transition of −7 days. Compared with the SSM/I‐derived information, the CRCM was found to delay systematically the onset of the snow cover (typically 50 days late) and to ablate snow too quickly during the spring melt period (typically 30 days early). These systematic errors were attributed to the single‐layer force–restore representation of the soil–snow layer and contributed to snow cover extent underestimations in the order of 9% relative to the total area. Copyright © 2004 John Wiley & Sons, Ltd.
Amino‐terminal processing of MIP‐1β/CCL4 by CD26/dipeptidyl‐peptidase IV
Authors: Guan Ennan , Wang Jinhai , Norcross Michael A.
Published: April 2004

CD26 is a membrane‐bound ectopeptidase with dipeptidyl peptidase IV (DPPIV) activity that has diverse functional properties in T cell physiology and in regulation of bioactive peptides. We have previously reported that activated human peripheral lymphocytes (PBL) secrete an amino‐terminal truncated form of macrophage inflammatory protein (MIP)‐1β/(3–69) with novel functional specificity for CCR1, 2, and 5. In this report, we show that the full length MIP‐1β is processed by CD26/DPPIV to the truncated form and that cleavage can be blocked by DPPIV inhibitory peptides derived from HIV Tat(1–9) or the thromboxane A2 receptor, TAX2‐R(1–9). Addition of Tat(1–9) or TAX2‐R(1–9) peptides to PBL cultures partially blocks endogenous MIP‐1β processing. The kinetics of conversion of MIP‐1β from intact to MIP‐1β(3–69) in activated PBLs correlates with cell surface expression of CD26. Our results suggest that NH2‐terminal processing of MIP‐1β and possibly other chemokines may depend on the balance between CD26/DPPIV enzymatic activity and cellular and viral proteins that modulate enzyme function. © 2004 Wiley‐Liss, Inc.
Effect of cell passage and density on protein kinase G expression and activation in vascular smooth muscle cells
Authors: Lin Guiting , Chow Sylvia , Lin Jackie , Wang Guifang , Lue Tom F. , Lin Ching‐Shwun
Published: April 2004

It has been shown that rat aortic smooth muscle cells (AoSMCs) lost PKG‐I expression when propagated repetitively or grown at low densities. Conversely, AoSMCs isolated from PKG‐I deficient mice are indistinguishable from those isolated from normal mice in morphology and growth characteristics. In this study, human AoSMCs were grown from passage 9 (p9) to passage 15 (p15) and rat AoSMCs were isolated and cultured from p1 through p15. Western blotting and immunofluorescence microscopy showed little difference in PKG‐I expression among different passages. Next, rat AoSMCs of p4 were grown and harvested at different cell densities. Western blotting again showed little difference among cells seeded or harvested at different densities. To test the effect of cell passage on PKG‐I activation, rat AoSMCs of p4 and p11 were treated with cGMP and analyzed by Western blotting for phosphorylated vasodilator‐stimulated phosphoprotein (P‐VASP). The results showed that p4 had higher level of PKG‐I activation than p11. © 2004 Wiley‐Liss, Inc.
IGF‐1 receptor contributes to the malignant phenotype in human and canine osteosarcoma
Authors: MacEwen E. Gregory , Pastor Josep , Kutzke Jonathan , Tsan Rachel , Kurzman Ilene D. , Thamm Douglas H. , Wilson Mike , Radinsky Robert
Published: April 2004

To further define the role of insulin‐like growth factor‐1 (IGF‐1) and its receptor (IGF‐1R) in osteosarcoma (OS), human OS cell lines with low (SAOS‐2) and high (SAOS‐LM2) metastatic potential and three canine OS‐derived cell lines were studied. Cell lines were evaluated for: IGF‐1R expression; expression of IGF binding proteins (IGFBPs); effect of IGF‐1 on tumor cell growth, invasion, expression of urokinase plasminogen activator (uPA), and soluble uPA receptor (suPAR), and; ectopic and orthotopic tumorigenicity of the canine OS cells in athymic mice. All cell lines exhibited steady‐state mRNA expression of IGF‐1R. The SAOS‐2 and SAOS‐LM2 cells expressed 9,138 and 10,234 cell‐associated binding sites, respectively. Canine OS cells expressed from 1,728 to 3,883 binding sites. Two IGF‐1‐treated cell lines displayed enhanced proliferation. Two cell lines formed colonies in semisolid media, and IGF‐1 increased colony number. Matrigel invasion was enhanced in one cell line following IGF‐1 treatment. uPA and suPAR were unchanged in SAOS‐2 and SAOS‐LM2 cells following IGF‐1 treatment, but the highly metastatic OS line SAOS‐LM2 expressed five times more suPAR and displayed enhanced invasion compared to the parental, low metastatic SAOS‐2. IGFBP‐5 was detected in four of five cell lines, and IGFBP‐3 was detected in two canine OS cell lines. Two canine OS lines were tumorigenic, and one metastasized spontaneously. In conclusion, OS cells express IGF‐1R, which can contribute to their growth and invasion. There is suggestive evidence that increasing receptor number may contribute to in vivo tumorigenesis. Additional studies are needed to determine how IGF‐1/IGF‐1R interactions contribute to the malignant phenotype of OS. © 2004 Wiley‐Liss, Inc.
Cloning and characterization of angiocidin, a tumor cell binding protein for thrombospondin‐1
Authors: Zhou Jing , Rothman Vicki L. , Sargiannidou Irene , Dimitrov Svetoslav , Qiu Cuie , Smith Elana , Sheffield Joel , Sharma Mahesh , Tuszynski George P.
Published: April 2004

Thrombospondin‐1 (TSP‐1) is a matrix protein that has been implicated in mechanisms of tumor progression. Our laboratory previously showed that the CSVTCG (cys‐ser‐val‐thr‐cys‐gly) sequence of TSP‐1 functioned as a tumor cell adhesion domain and CSVTCG peptides as well as an anti‐peptide antibody possessed anti‐metastatic activity in a murine model of lung metastasis. In a subsequent study, a putative TSP‐1 binding protein from lung carcinoma was isolated by CSVTCG‐peptide affinity chromatography. In this study, we present the full‐length cDNA of this binding protein isolated from a prostate cancer cell (PC3‐NI) cDNA library. The purified recombinant protein, termed angiocidin, is a potent inhibitor of tumor growth of Lewis Lung carcinoma in vivo and tumor invasion and angiogenesis in vitro. In addition, the recombinant protein inhibits tumor and endothelial cell proliferation and induces apoptosis. The activity of angiocidin both in vivo and in vitro is partially dependent on its TSP‐1 binding activity, since an angiocidin deletion mutant missing a high affinity‐binding site for TSP‐1 failed to inhibit tumor growth in vivo and was less active in its anti‐tumor and anti‐angiogenic activities in vitro. These results suggest that the anti‐tumor activity of TSP‐1 reported in many studies may be mediated in part by binding proteins such as angiocidin. Such proteins may function as tumor‐suppressor proteins, which limit the growth of tumors by inhibiting angiogenesis and cell matrix interaction. © 2004 Wiley‐Liss, Inc.
Individual empowerment: How community health workers operationalize self‐determination, self‐sufficiency, and decision‐making abilities of low‐income mothers
Authors: Becker Julie , Kovach Andrea Crivelli , Gronseth Dickie Lynn
Published: April 2004

The purposes of this study were to operationalize individual empowerment within the context of the MOMobile Program, to explore the relationships formed between MOMobile Advocates and their clients, and to develop an appropriate survey instrument for assessing the impact of a Community Health Worker (CHW) intervention in a community‐based social service agency. Phase I of a multiphase study used focus group interviews with MOMobile Advocates to operationalize empowerment, define their professional roles, and explore the relationships formed with their clients. This article focuses specifically on operationalizing individual empowerment and describing the relationships formed between the Advocates and their clients. Three major themes emerged: (1) the importance of relationships established between Advocates and their clients, (2) the resources available to the clients, and (3) the ability of Advocates to become change agents for their clients. The Community Health Worker (CHW) model is effective for health promotion in disadvantaged communities. MOMobile Advocates improve quality of life by fostering better patient–provider communication, continuity of care, and help‐seeking behavior and by expanding the women's social support systems. Research examining relationships between CHWs and the mothers they assist is needed to assess the full impact of this construct as a health status indicator. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 327–342, 2004.
Asian American adolescents' acculturation, binge drinking, and alcohol‐ and tobacco‐using peers
Authors: Hahm Hyeouk C. , Lahiff Maureen , Guterman Neil B.
Published: April 2004

This study examines the association between acculturation and subsequent binge drinking among Asian American adolescents and investigates the mediating effect of friends' alcohol and tobacco use. Data from a nationally representative sample of 714 Asian American adolescents in grades 7 to 12 were analyzed. There was no gender difference in terms of binge drinking. A higher level of acculturation was associated with higher levels of binge drinking. Friends' alcohol and tobacco use was a mediator—the association between acculturation and binge drinking was no longer significant after controlling for best friends' alcohol and tobacco use. These findings demonstrate that binge drinking is not attributable to acculturation per se, but that social interaction is an important pathway by which highly acculturated adolescents become vulnerable to binge drinking. Since highly acculturated Asian American adolescents are at risk for binge drinking, there is an urgent need for prevention. Incorporating the effect of peer influences will improve both prevention efforts and treatment for Asian American adolescents who are binge drinkers. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 295–308, 2004.