bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective permeability of hydrophilic substances through walls of lymph vessels: roles of endothelial barrier
Authors: Ono Nobuyuki , Mizuno Risuke , Ohhashi Toshio
Published: June 2005

The wall effective permeability of hydrophilic substances labeled with fluorescent dyes was evaluated in an isolated cannulated rat single lymph vessel through a videomicroscope system. Sodium fluorescein (NaFl; 332 mol wt) and FITC-dextrans (4,400, 12,000, and 71,200 mol wt) were administered into the intraluminal space of the lymph vessels and then excited by a Xenon lamp. Changes in the fluorescence intensity of the dyes were continuously measured by a silicon-intensified target camera through appropriate filters. The net flux of each dye in the wall of the lymph vessels was calculated by the relationship between the fluorescence intensity and the concentration of the dyes. NaFl and FITC-dextran 4,400 in the intraluminal space of isolated rat lymph vessels significantly penetrated the wall of the lymph vessels. FITC-dextran 12,000 in the intraluminal space of isolated rat lymph vessels slightly passed through the lymphatic wall, whereas FITC-dextran 71,200 did not penetrate the wall. Intraluminal pressures ranging from 4 to 8 cmH2O did not significantly affect the net flux of dyes used in the present study. After administration of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate into the lymph vessels, the net flux of FITC-dextran 4,400 and 12,000 but not 71,200 was augmented significantly. These results suggest that small molecular hydrophilic substances (≤4,400) are permeable from the intraluminal to extraluminal space of isolated lymph vessels and that the endothelial cell surface structure may play a barrier role in the effective permeability of large molecular hydrophilic substances (4,400 to 12,000) through the wall of the lymph vessels.
Lipid Transfer Proteins from Fruit: Cloning, Expression and Quantification
Authors: Zuidmeer Laurian , van Leeuwen W. Astrid , Kleine Budde Ilona , Cornelissen Jessica , Bulder Ingrid , Rafalska Ilona , Telléz Besolí Noèlia , Akkerdaas Jaap H. , Asero Riccardo , Fernandez Rivas Montserrat , Gonzalez Mancebo Eloina , van Ree Ronald
Published: June 2005

Background: Lipid transfer proteins (LTP) are stable, potentially life-threatening allergens in fruits and many other vegetable foods. The aim of this study was to clone and express recombinant apple LTP (Mal d 3), as has previously been done for peach LTP (Pru p 3) and set up quantitative tests for measuring fruit LTPs. Methods: cDNA for Mal d 3 and Pru p 3 was cloned, expressed in the yeast Pichia pastoris and the resulting proteins were purified via cation exchange chromatography. The immune reactivity of rMal d 3 was compared to nMal d 3 by RAST (inhibition), immunoblotting and basophil histamine release testing. To obtain monoclonal and monospecific polyclonal antibodies, mice and rabbits were immunized with purified nMal d 3. Results: The deduced amino acid sequence of Mal d 3 was identical to the published sequence, Pru p 3 differed at two positions (S9A and S76H). The rMal d 3 had an IgE-binding potency and biological activity close to its natural counterpart. One sandwich ELISA selectively detecting apple LTP and another cross-reactive with cherry, nectarine and hazelnut LTP were developed. In addition, a competitive RIA was developed with polyclonal rabbit antiserum and labeled nMal d 3. Conclusion: rMal d 3 (as shown before for rPru p 3) may be a useful tool for application in component-resolved diagnosis of food allergy. Assays for the measurement of LTP will increase the traceability of this potentially dangerous allergen.
Genetic and Environmental Factors in the Immunopathogenesis of Atopy: Interaction of Helicobacter pylori Infection and IL4 Genetics
Authors: Pessi T. , Virta M. , Ådjers K. , Karjalainen J. , Rautelin H. , Kosunen T.U. , Hurme M.
Published: June 2005

Background: Both genetic and environmental factors, e.g. early childhood infections, have a role in the pathogenesis of atopic diseases. Objective: To examine simultaneously the strength and possible interactions of two known such factors, IL4 genetics and Helicobacter pylori infection, on the risk of atopy and asthma. Methods: Gene polymorphism analyses and skin prick tests (SPT) were determinedin 245 adult asthmatics and 405 nonasthmatic controls of population-based case-control study. SPTs were used as an indicator of atopy. H. pylori infection was verified by detecting anti-H. pylori IgG antibodies in sera. Results: A significant negative association was seen between the presence H. pylori antibodies and SPT positivity (≧1 positive reactions) in both asthmatics and controls (p = 0.002 and p = 0.025, respectively) but the effect of IL-4 polymorphism (SNP –590C/T) was nonsignificant in both groups (p = 0.071 and p = 0.072, respectively). However, IL4 genetics had an effect on susceptibility to H. pylori: asthmatics carrying the IL4 –590 allele T had a diminished risk to be H. pylori infected (OR 0.485 95%CI 0.287–0.819). This effect was not seen in controls. Logistic regression analysis indicated that H. pylori and IL4 effects on atopy risk are not interdependent. Conclusions: This study showed that the effect of H. pylori infection on atopy risk is stronger than that of IL4 genetics. There is no interaction between these factors on the pathogenesis of atopy suggesting that these factors have distinct immunopathogenetic mechanisms. However, the genetic effect may modify the role of infective agents by effecting on susceptibility to disease.
Lay Rescuer Automated External Defibrillator (“Public Access Defibrillation”) Programs
Authors: Hazinski Mary F. , Idris Ahamed H. , Kerber Richard E. , Epstein Andrew , Atkins Dianne , Tang Wanchun , Lurie Keith
Published: June 2005

Lay rescuer automated external defibrillator (AED) programs may increase the number of people experiencing sudden cardiac arrest who receive bystander cardiopulmonary resuscitation (CPR), can reduce time to defibrillation, and may improve survival from sudden cardiac arrest. These programs require an organized and practiced response, with rescuers trained and equipped to recognize emergencies, activate the emergency medical services system, provide CPR, and provide defibrillation. To determine the effect of public access defibrillation (PAD) programs on survival and other outcomes after SCA, the National Heart, Lung, and Blood Institute, the American Heart Association (AHA), and others funded a large prospective randomized trial. The results of this study were recently published in
The New England Journal of Medicine
and support current AHA recommendations for lay rescuer AED programs and emphasis on planning, training, and practice of CPR and use of AEDs. The purpose of this statement is to highlight important findings of the Public Access Defibrillation Trial and summarize implications of these findings for healthcare providers, healthcare policy advocates, and the AHA training network.
Mitochondrial DNA, allozymes, morphology and historical biogeography in the Podarcis vaucheri (Lacertidae) species complex
Authors: Busack Stephen , Lawson Robin , Arjo Wendy
Published: June 2005

Mitochondrial DNA analysis indicates that Podarcis vaucheri is a species
complex with one clade inhabiting both north and south shores of the Strait
of Gibraltar and one clade restricted to North Africa. While each clade
exhibits differing morphology, allozyme analysis suggests varying degrees of
reproductive contact among populations within clades. Ancestral P. vaucheri
appears to have been restricted to insular areas of the Betic-Rif Massif and
mainland Africa during Miocene, with major lineage differentiation occurring
during Pliocene.Our analysis further confirms that Podarcis atrata warrants
species status and suggests that it may be more widely distributed than
previously reported.
Intermediate-Depth Circulation of the Indian and South Pacific Oceans Measured by Autonomous Floats
Authors: Davis Russ E.
Published: June 2005

As part of the World Ocean Circulation Experiment, 306 autonomous floats were deployed in the tropical and South Pacific Ocean and 228 were deployed in the Indian Ocean to observe the basinwide circulation near 900-m depth. Mean velocities, seasonal variability, and lateral eddy diffusivity from the resultant 2583 float-years of data are presented. Area averages, local function fits, and a novel application of objective mapping are used to estimate the mean circulation. Patterns of mean circulation resemble those at the surface in both basins. Well-developed subtropical gyres, twice as strong in the Indian Ocean as in the Pacific, feed western boundary currents. Tropical gyres are separated by eastward flow along the equator in both hemispheres of both basins, although the Indian subcontinent splits the north Indian tropical gyre. The Antarctic Circumpolar Current (ACC) and west wind drifts are prominent in both basins, generally tending slightly southward but deviating to the north behind the Del Cano, Kerguelen, and Campbell Plateaus and, of course, South America. Remarkably, the eastern boundaries of the southern subtropical gyres in all three basins apparently occur in the ocean interior, away from land. The Indian Ocean’s subtropical gyre, and perhaps part of the South Atlantic’s, reaches east to a retroflection just upstream of the Campbell Plateau south of New Zealand. Seasonal variability at 900 m is focused around the equator with weaker variability found near certain bathymetric features. There is a remarkable agreement between the observed seasonable variability and that predicted by the Jet Propulsion Laboratory (JPL)–Estimating the Circulation and Climate of the Ocean (ECCO) data-assimilating numerical model. Aside from seasonal effects, eddy variability is greatest along the equator, in tropical and subtropical western basins, and along the ACC. Integrals of velocity across regional passages (Tasman Sea, Mozambique Channel) provide useful reference for hydrographic analyses of transport. Across whole ocean basins, however, the uncertainty associated with the appropriate continuity relation for horizontal flow (e.g., geostrophy vs nondivergence) is comparable to the mean flow.
Parameterizing the Sea Surface Roughness
Authors: Drennan William M. , Taylor Peter K. , Yelland Margaret J.
Published: June 2005

The concept of an “equivalent surface roughness” over the ocean is useful in understanding the relation between wind speed (at some height) and the net momentum flux from air to sea. The relative performance of different physics-motivated scalings for this roughness can provide valuable guidance as to which mechanisms are important under various conditions. Recently, two quite different roughness length scalings have been proposed. Taylor and Yelland presented a simple formula based on wave steepness, defined as the ratio of significant wave height to peak wavelength, to predict the surface roughness. A consequence of this formula is that roughness changes due to fetch or duration limitations are small, an order of 10%. The wave steepness formula was proposed as an alternative to the classical wave-age scaling first suggested by Kitaigorodskii and Volkov. Wave-age scaling, in contrast to steepness scaling, predicts order-of-magnitude changes in roughness associated with fetch or duration. The existence of two scalings, with different roughness predictions in certain conditions, has led to considerable confusion among certain groups. At several recent meetings, including the 2001 World Climate Research Program/Scientific Committee on Oceanic Research (WCRP/SCOR) workshop on the intercomparison and validation of ocean–atmosphere flux fields, proponents of the two scalings met with the goal of understanding the merits and limitations of each scaling. Here the results of these efforts are presented. The two sea-state scalings are tested using a composite of eight datasets representing a wide range of conditions. In conditions with a dominant wind-sea component, both scalings were found to yield improved estimates when compared with a standard bulk formulation. In general mixed sea conditions, the steepness formulation was preferred over both bulk and wave-age scalings, while for underdeveloped “young” wind sea, the wave-age formulation yields the best results. Neither sea-state model was seen to perform well in swell-dominated conditions where the steepness was small, but the steepness model did better than the wave-age model for swell-dominated conditions where the steepness exceeded a certain threshold.
The Behavior of Jet Currents over a Continental Slope Topography with a Possible Application to the Northern Current
Authors: Flexas M. M. , van Heijst G. J. F. , Trieling R. R.
Published: June 2005

The Northern Current is a slope current in the northwest Mediterranean that shows high mesoscale variability, generally associated with meander and eddy formation. A barotropic laboratory model of this current is used here to study the role of the bottom topography on the current variability. For this purpose, a source–sink setup in a cylindrical tank placed on a rotating table is used to generate an axisymmetric barotropic current. To study inviscid topographic effects, experiments are performed over a topographic slope and also over a constant-depth setup, the latter being used as a reference for the former. With the aim of obtaining a fully comprehensive view of the vorticity balance at play, the flow may be forced in either azimuthal direction, leading to a “westward” prograde current (similar to the Northern Current) or an “eastward” retrograde current. For slow flows, eastward and westward currents showed similar patterns, dominated by Kelvin–Helmholtz-type instabilities. For high-speed flows, eastward and westward currents showed very different behavior. In eastward currents, the variability is observed to concentrate toward the center of the jet and shows strong meandering formation. Westward currents, instead, showed major variability toward the edges of the jet, together with a strong variability over the uppermost slope, which has been associated here with a topographic Rossby wave trapped over the shelf break. The differences between eastward and westward jets are explained through the balance between shear-induced and topographically induced vorticity at play in each case. Moreover, a model of jets over a beta plane is successfully applied here, allowing its extension to any ambient potential vorticity gradient caused either by latitudinal or bottom depth changes.
Viscosity-Dependent Internal Variability in a Model of the North Pacific
Authors: Dawe Jordan T. , Thompson Lu Anne
Published: June 2005

A 2°-resolution isopycnal model of the North Pacific Ocean is shown to produce anomalies that propagate around the subtropical gyre on the decadal time scale that do not appear in a 1°-resolution version of the same model. A principal oscillation pattern (POP) analysis of the isopycnal interface anomaly is performed to examine the dynamics responsible for the anomaly generation. The POPs show a coherent oscillation around the entire subtropical gyre with two centers of action, one in the Central Mode Water (CMW) region, the other in the Subtropical Countercurrent (STCC). Lead–lag covariances between the subduction rate in the CMW and the layer thickness along the oscillation path indicate that anomalous subduction events are not the driving mechanism for the oscillation. A linearized quasigeostrophic mode analysis shows that the anomalies are generated by flow instability in the region of the STCC. The instability disappears in the 1° model because of changes in the horizontal viscosity, which is set in each model to the minimum value necessary to resolve the western boundary current and preserve numerical stability. A criterion for model resolution of an instability of a given length and time scale damped by biharmonic viscosity is derived. The enhancement of the large-scale instabilities in the low-resolution model emphasizes the importance of achieving mesoscale resolution in ocean models used for climate studies.
Wind-Driven Oceanic Rossby Waves in the Tropical South Indian Ocean with and without an Active ENSO
Authors: Baquero-Bernal Astrid , Latif Mojib
Published: June 2005

The interannual heat content variability in the tropical south Indian Ocean (SIO) and its relationship with El Niño–Southern Oscillation (ENSO) is studied. The baroclinic ocean response to stochastic wind stress predicted by a simple analytical model is compared with two integrations of the ECHO-G coupled general circulation model. In one integration, ocean–atmosphere interactions are suppressed in the tropical Pacific Ocean, so that this integration does not simulate ENSO. In the other integration, interactions are allowed everywhere and ENSO is simulated. The results show that basinwide variability in the SIO heat content can be produced by two mechanisms: 1) oscillatory forcing by ENSO-related wind stress and 2) temporally stochastic and spatially coherent wind stress forcing. Previous studies have shown that transmission of energy from the tropical Pacific to the southern Indian Ocean occurs through coastal Kelvin waves along the western coast of Australia. The results in this paper confirm the occurrence of such transmission. In the ECHO-G simulations, this transmission occurs both at the annual time scale and at interannual time scales. Generation of offshore Rossby waves by these coastal Kelvin waves at interannual time scales—and, in particular, at the ENSO time scale—was found.
Origins and Dynamics of the 90-Day and 30–60-Day Variations in the Equatorial Indian Ocean
Authors: Han Weiqing
Published: June 2005

Sea level observations in the equatorial Indian Ocean show a dominant spectral peak at 90 days and secondary peaks at 30–60 days over an intraseasonal period (20–90 days). A detailed investigation of the origins and dynamics of these variations is carried out using an ocean general circulation model, namely, the Hybrid Coordinate Ocean Model (HYCOM). Two parallel experiments are performed in the tropical Indian Ocean basin for the period 1988–2001: one is forced by NCEP 3-day mean forcing fields together with the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) pentad precipitation, and the other is forced by monthly mean fields. To help to understand the role played by the wind-driven equatorial wave dynamics, a linear continuously stratified ocean model is also used. Both the observed and modeled 90-day sea level anomaly fields and HYCOM surface current clearly show equatorial Kelvin and first-meridional-mode Rossby wave structures that are forced by the 90-day winds. The wind amplitude at the 90-day period, however, is weaker than that for the 30–60-day period, suggesting that the equatorial Indian Ocean selectively responds to the 90-day winds. This selective response arises mainly from the resonant excitation of the second-baroclinic-mode (n = 2) waves by the 90-day winds. In this case, Rossby waves reflected from the eastern ocean boundary enhance the directly forced response in the ocean interior, strengthening the 90-day peak. In addition, the directly forced response increases monotonically with the increase of forcing period, contributing to the larger variances of currents and sea level at 90 days. Two factors account for this monotonic increase in directly forced response. First, at lower frequency, both Rossby and Kelvin waves associated with the low-order baroclinic modes have longer wavelengths, which are more efficiently excited by the larger-scale winds. Second, responses of the high-order modes directly follow the local winds, and their amplitudes are proportional to both forcing period and wind strength. Although most energy is surface trapped, there is a significant amount that propagates through the pycnocline into the deep ocean. The dominance of the 90-day peak occurs not only at the surface but also in the deeper layers down to 600 m. In the deeper ocean, both the directly forced response and reflected waves associated with the first two baroclinic modes contribute to the 90-day variation. Spectra of the observed sea surface temperature (SST) also show a 90-day peak, likely a result of the selective response of the equatorial Indian Ocean at the 90-day period. Near the surface, the spectral peaks of currents and sea level at the 30–60-day period are directly forced by winds that peak at 30–60 days. In the deeper layers, both directly forced and reflected waves associated with the first two baroclinic modes contribute. Oceanic instabilities can have significant contributions only near the western boundary and near 5°N south of Sri Lanka.
Brief Communication: Factors Affecting Rehospitalisation in Psychiatric Patients in Singapore
Authors: Mahendran Rathi , Mythily  , Chong Siow-Ann , Chan Yiong Huak
Published: June 2005

Objectives: To study the patterns of readmission in Singapore using a cohort of first admission schizophrenia patients to the state mental health institute.

Methods: A retrospective analysis of case records was done of first admission schizophrenia patients to the hospital from April 1993 to March 1994. Patients who had only one admission in the five years of follow up were compared to ‘revolving door patients’.

Results: The cohort comprised 133 males (56.8%) and 101 females (43.2%). Seventy-eight patients (33.3%) had one admission to the hospital while 56 (23.9%) fulfilled the revolving door criteria. On performing a logistic regression we found sex (p1/4 0.02), shorter duration of illness (p1/4 0.01) and CPN referral (0.006) were significantly associated with revolving door phenomena.

Conclusions: Our study has identified male gender, history of self-harm and a short duration of illness to be risk factors for ‘revolving door’ phenomena.
Psychiatric Disorders among the Mapuche in Chile
Authors: Vicente Benjamin , Kohn Robert , Rioseco Pedro , Saldivia Sandra , Torres Silverio
Published: June 2005

Background: The Mapuche are the largest indigenous group in Chile; yet almost all data on the mental health of indigenous populations are from North America. Aim: The study examines the differential DSM-III-R prevalence rates of psychiatric disorders and service utilization among indigenous and non-indigenous community residence.

Methods: The Composite International Diagnostic Interview (CIDI) was administered to a stratified random sample of 75 Mapuche and 434 non-Mapuche residents of the province of Cautín. Lifetime prevalence and 12-month prevalence rates were estimated.

Results: Approximately 28.4% of the Mapuche population had a lifetime, and 15.7% a 12-month, prevalent psychiatric disorder compared to 38.0% and 25.7%, respectively, of the non-Mapuche. Few significant differences were noted between the two groups; however, generalized anxiety disorder, simple phobia, and drug dependence were less prevalent among the Mapuche. Service utilization among the Mapuche with mental illness was low.

Conclusions: This is a preliminary study based on a small sample size. Further research on the mental health of indigenous populations of South America is needed.
Challenging Stigma and Discrimination in Communities: A Focus Group Study Identifying UK Mental Health Service Users’ Main Campaign Priorities
Authors: Pinfold Vanessa , Byrne Peter , Toulmin Hilary
Published: June 2005

Background: Stigma and discrimination experienced by people with mental health problems have been identified as major obstacles to treatment and recovery. Less is known about how to effectively tackle stigma-discrimination, although there are numerous international, national and local programmes attempting to improve public mental health literacy and anti-discrimination evidenced based practice.

Aims: To explore mental health service users’ views on how campaigns to address stigma and discrimination should prioritise their actions.

Method: Qualitative study using focus group discussions, involving 33 persons aged between 25 and 75.

Results: A triad of diminished credibility, dis-empowerment with particular reference to communication problems and avoidance by their social network defined experiences of stigma. Reactions to stigma can be placed in four categories: avoid stigma, resign yourself to it, challenge it, or distance yourself from others with a mental health problem. A range of solutions was discussed with most favouring changes within the health services that are currently supporting them over traditional educational programmes with the public.

Conclusions: For mental health service users stigma must be tackled on many different levels reflecting the varied and complex impact that negative social reactions have on an individual’s life. When asked to prioritise one area, most service users in our sample highlighted reforms within the health service for tackling stigma and discrimination.
Community Attitudes Towards the Mentally Ill: The Results of a National Survey of the Taiwanese Population
Authors: Song Li-Yu , Chang Ly-Yun , Shih Chaiw-Yi , Lin Chih-Yuan , Yang Ming-Jeng
Published: June 2005

Background: In Taiwan, to strengthen the psychiatric rehabilitation system has been one of the primary goals of the Department of Health since 1985. Unfortunately, this endeavor has not been successful and it is believed that one of the barriers is social stigma towards the mentally ill. However, to date no national survey has been conducted for Chinese population on the focal topic using a random sample.

Aims: In this study we explored the attitudes of the general population towards the mentally ill in Taiwan. Specifically, we examined the effect of contact on one’s attitudes after controlling for demographic variables.

Methods: A national survey was conducted on 1,203 subjects drawn through a stratified proportional random sampling. Data were collected using the Computer-Assisted Telephone Interview System. We conducted MANOVA and multiple regression analyses to explore the correlates of the attitudes.

Results: The results revealed that the general population held relatively higher levels of benevolence, tolerance on rehabilitation in the community, and nonsocial restrictiveness. However, they held relatively less positive attitudes on non-authoritarianism and normalization. Overall, direct contact and age were the two most important correlates of community attitudes. Education and occupation were also significant.

Conclusions: Benevolent thoughts do not necessarily guarantee the acceptance of rehabilitation in the community or treating the mentally ill as a person like anyone else. However, the benevolent thought could be transformed into compassion and acceptance of another human being if people are given the opportunity to have direct contact with mentally ill persons. The results also indicated that community education should specifically target laborers of all age groups.
Tailored Surfactant Solutions to Optimize Foam Performance in HFC-245fa-blown Appliance Systems
Authors: Eilbracht Christian , Hohl Peter
Published: June 2005

This article discusses the growing role that surfactant technology plays in the ‘next-generation’ 245fa appliance systems. A series of experiments have been designed to illustrate how tailor-made surfactants can improve foam quality and provide better utilization of the HFC-245fa blowing agent. The resulting data, based on high-pressure machine evaluations, clearly demonstrates the value an optimized surfactant has on the resulting foam performance. These improvements have translated into significantly reduced freeze stable densities, lower minimum fill densities, and improved k-factors in a selection of ‘next-generation’ 245fa systems. Tailor-made surfactants are a powerful tool in helping to meet the appliance manufacturers’ ongoing demand for balancing foam performance with lowest cost-in-use production.
trans-1,2-Dichloroethylene as an Additive for HFC-134a Foam Systems
Authors: Wu Jinhuang , Bertelo Chris , Enaux Vincent
Published: June 2005

HFC-134a has been used as a zero ozone depletion potential (ODP) alternative for HCFC-141b in polyurethane foam applications. Between two major categories of zero ODP alternatives, hydrocarbons and HFCs, HFC-134a offers some advantages. It is nonflammable, widely available, and it is less expensive than other HFCs. It is an ideal choice for foam applications where nonflammability, volatile organic compounds (VOCs), and blowing agent costs are major issues. Yet, HFC-134a suffers from one significant drawback - it has limited solubility in polyurethane raw materials, such as polyols. Although the issue can be alleviated by careful selection of polyols and use of coblowing agents, such as water, there is a need to further improve the system.

trans-1,2-Dichloroethylene (TDCE) is a liquid at room temperature (b.p. 48 C). It has no ozone depletion potential1 (ODP), and it has very low global warming potential (GWP) because it has very short atmospheric lifetime. Previously, we found that the addition of TDCE in HFCs-based urethane foam formulations significantly improved the fire performance.

In this study, we evaluated the effect of TDCE on the vapor pressure of several HFC-134a-polyol combinations. The results show that the presence of TDCE can reduce the vapor pressure of certain HFC-134a-polyol blends. More importantly, the presence of TDCE allows one to reduce the levels of HFC-134, significantly reducing the overall vapor pressure of HFC-134a-containing systems. Finally, the presence of TDCE can dramatically reduce the viscosity of HFC-134a-polyols blends, which is important for some applications.
Hydroxyl Carbonateapatite Hybrid Bone Composites Using Carbohydrate Polymer
Authors: Murugan R. , Kumar T. S.Sampath , Yang F. , Ramakrishna S.
Published: June 2005

Bioresorption and particulate migration of hydroxyl carbonateapatite (HCAp) are the common clinical problems in periodontal osseous defects. In this study, an attempt is made to prepare a hybrid bone composite with chitosan-incorporated HCAp to alleviate the above demerits. The prepared composites are analyzed by various physicochemical methods and the HCAp is found to be well intact in the chitosan macromolecules. Chemical analysis clearly indicates the presence of hydroxyl and amide groups in addition to the characteristic bands of HCAp in the composites. The particle size of the HCAp has increased tremendously with increasing the conjugation of chitosan, which is highly beneficial for the immobilization of HCAp particles upon implantation. Physiological stability and solubility of the bone composites are carried out in vitro in Hank’s medium of pH 7.4 in a temperature-controlled incubator and found that the dissolution rate of calcium ions is quite higher in the composites than in HCAp. No structural deformations are detected for HCAp due to the presence of chitosan as evidenced by the X-ray diffraction (XRD) method. These findings suggest that HCAp-chitosan composites can efficiently be used as a bioresorbable bone substitute and the bioresorbability can also be controlled by optimizing the chitosan incorporation.
Using Approximation with Time-Parallel Simulation
Authors: Kiesling Tobias
Published: June 2005

Temporal decomposition of simulation models, which is used in time-parallel simulation, is a promising alternative to classical spatial decomposition. It has been successfully applied to a small number of different models, most prominently for the simulation of computer caches and queuing systems. Unfortunately, widespread use is prevented by the state-match problem, which restricts the application of time-parallel simulation. Instead of a correct solution to the state-match problem, this work proposes the use of approximate solutions to facilitate the temporal decomposition of simulation models and to extend the class of models suitable for time-parallel simulation. However, this introduces an error in the simulation results, which might seriously distort or even invalidate results. Therefore, the error must be closely analyzed, and a method of error control must be provided. In addition to the basic properties of approximate techniques in time-parallel simulation, this work presents two use cases that illustrate the introduced concepts.
An Agent-Based Simulation Testing the Impact of Water Allocation on Farmers’ Collective Behaviors
Authors: Le Bars M. , Attonaty J. M. , Pinson S. , Ferrand N.
Published: June 2005

Many negotiations take place between farmers, water suppliers, public servants, and environmentalists to allocate water resources between users in different areas. However, few negotiations quantify the consequences of alternatives solutions. Models that are used are often oversimplified and only take into account elements that are easy to calculate, or they are too complex to be used for negotiations in real time. In all cases, they do not consider the heterogeneity of decision makers. The authors demonstrate that agent-based modeling could help these negotiations by showing the consequences of water allocation rules with respect to different criteria.
Multiagent Modeling and Simulation of Hydraulic Management of the Camargue
Authors: Espinasse Bernard , Franchesquin Nathalie
Published: June 2005

Modeling and simulation of human-influenced ecosystems require the integration of natural and decision-making processes. In such ecosystems, natural resource management aims at protecting natural areas while enabling human activities that contribute to these area characteristics. The object of this research is the modeling and simulation of the hydraulic management of the Camargue ecosystem with a multiagent system. The authors first present the problematics of this hydraulic management, its objectives, and a formalization of the different decision processes centered on a social contract and associated with two main phases: the contract elaboration phase and the contract realization phase. They present conceptual modeling and multiagent modeling of these two phases with details on agent models, agent behaviors, and negotiation models.
A Framework for Formalization and Strictness Analysis of Simulation Event Orderings
Authors: Teo Y. M. , Onggo B. S. S.
Published: June 2005

This article advocates the use of a formal framework for analyzing simulation performance. Simulation performance is characterized based on the three simulation development process boundaries: physical system, simulation model, and simulator implementation. First, the authors formalize simulation event ordering using partially ordered set theory. A simulator implements a simulation event ordering and incurs implementation overheads when enforcing event ordering at runtime. Second, they apply their formalism to extract and formalize the simulation event orderings of both sequential and parallel simulations. Third, they propose the relation stricter and a measure called strictness for comparing and quantifying the degree of event dependency of simulation event orderings, respectively. In contrast to the event parallelism measure, strictness is independent of time.
Optimistic Synchronization in HLA-Based Distributed Simulation
Authors: Wang Xiaoguang , Turner Stephen John , Low Malcolm Yoke Hean , Gan Boon Ping
Published: June 2005

With the wide use of commercial off-the-shelf (COTS) simulation packages and the advent of the High Level Architecture (HLA) standard, it is desirable to build distributed simulations by linking various types of simulation models developed using best-fit COTS packages. While almost all current work on integrating COTS packages and the HLA is based on conservative synchronization, it is worthwhile to investigate the optimistic synchronization approach. The optimistic approach can exploit parallelism and achieve promising performance in situations where causality errors may occur but in fact seldom occur. The authors introduce a rollback controller using a middleware approach to handle the complex rollback procedure on behalf of the simulation model. A new time advance algorithm is proposed that can fully use the benefits of optimistic synchronization. The article also describes a scalability study showing the experimental results for the two synchronization approaches as the number of simulation components increases.
Empirical Validation of Wireless Models in Simulations of Ad Hoc Routing Protocols
Authors: Liu Jason , Yuan Yougu , Nicol David M. , Gray Robert S. , Newport Calvin C. , Kotz David , Perrone Luiz Felipe
Published: June 2005

Computer simulation has been used extensively as an effective tool in the design and evaluation of systems. One should not, however, underestimate the importance of validation—the process of ensuring whether a simulation model is an appropriate representation of the real-world system. Validation of wireless network simulations is difficult due to strong interdependencies among protocols at different layers and uncertainty in the wireless environment. The authors present an approach of coupling direct-execution simulation and traces from real outdoor experiments to validating simple wireless models that are used commonly in simulations of wireless ad hoc networks. This article documents a common testbed that supports direct execution of a set of ad hoc routing protocol implementations in a wireless network simulator. By comparing routing behavior measured in the real experiment with behavior computed by the simulation, the authors validate the models of radio behavior upon which protocol behavior depends.
Citizenship, Ethnicity and Identity
Authors: Hussain Yasmin , Bagguley Paul
Published: June 2005

There have been few studies of citizenship as an identity. This article explores citizenship as an identity among British Pakistanis in Bradford after the ‘riot’ in 2001, using qualitative data. The 2001 ‘riots’, the political successes of the British National Party and the events after September 11 pushed British-Pakistani Muslims into the forefront of national political conflicts around citizenship, national identity and allegiance to the state. Through the analysis of interviews with both first- and second-generation British Pakistanis we examine how citizenship as a mode of identity is contextualized by them in relation to national identity, Islam and ethnicity. We identify the two generations’ different ‘citizenship identities’. The second generation have a strong British identity as ‘British citizens’ with the ‘natural rights’ of a British-born citizen. In contrast the first-generation migrants from Pakistan express identities as ‘denizens’, living but not belonging in a foreign country, who remain because their children are now ‘British’.
The Effect of Downgauging on the Physicomechanical Properties of Film Blends of Linear Low-density Polyethylene with Low-density Polyethylene
Authors: Cran Marlene J. , Bigger Stephen W.
Published: June 2005

Two series of film formulations are investigated comprising blends of a metallocene-catalyzed linear low-density polyethylene (mLLDPE) or a conventional linear low-density polyethylene (LLDPE) with a low-density polyethylene (LDPE). The physicomechanical and optical properties are studied at various gauge lengths to investigate the effects of downgauging the films, particularly those containing mLLDPE. The potential for downgauging is found to be optimum at higher levels of mLLDPE with the best results achieved for a film containing 40 wt.% mLLDPE at 60 mm. This formulation has significantly better properties than an analogous blend containing 40 wt.% LLDPE at 100 mm. The potential materials and cost savings associated with downgauging films is also briefly investigated.
Strain Energy Density of Rubber-like Shells of Arbitrary Geometry
Authors: Yükseler Recep Faruk
Published: June 2005

An approach for the derivation of two-dimensional strain energy density functions of incompressible, rubber-like shells of arbitrary geometry undergoing finite rotations and finite strains, including transverse normal strains, is presented. Transverse shear strains are neglected.
Estimation of Thermal Parameters of Halogenated Polymers Based on Group Additive Methods
Authors: Begum Muneera , Siddaramaiah
Published: June 2005

The thermal parameters such as, glass transition temperature (Tg), crystalline melting point (Tm), initial thermal degradation temperature (Td,0), and coefficient of thermal expansion (Eg) of some halogenated polymers have been estimated employing two different relations such as the Van Krevelen method and the Askadskii method based on the group additive principle. The estimated parameters were compared with the experimental values. The estimated thermal parameters by the Van Krevelen method are found to be more accurate, rapid, and simple than the Askadskii method, except for a crystalline melting point.
Structure and Properties of Model Polybutadienes - Effect of Microstructure on the Dynamic Mechanical Properties of Rubber
Authors: Rivera Marvin R. , Nájera Rafael Herrera , Tapia Juan José Benvenuta , Guerrero Leonardo Ríos
Published: June 2005

A series of controlled microstructure polybutadiene rubbers (PBs) was synthesized via anionic polymerization. Their structure and proper ties are analyzed by means of GPC, 13C NMR, DSC, and DMA, and compared to the behavior of some commercial high cis rubbers. Thermal analyses results indicate the presence of crystalline domains of different nature in PBs with high cis-1,4 and high trans-1,4 isomers content, while rubbers with high content of vinyl-1,2 units do not show evidence of crystals. A shift in Tg to higher temperatures as vinyl content increases is observed; an expression was found for predicting Tg of rubber from microstructure data.
Contextomy: the art of quoting out of context
Authors: McGlone Matthew S.
Published: June 2005

‘Contextomy’ refers to the selective excerpting of words from their original linguistic context in a way that distorts the source’s intended meaning, a practice commonly referred to as ‘quoting out of context’. Contextomy is employed in contemporary mass media to promote products, defame public figures and misappropriate rhetoric. A contextomized quotation not only prompts audiences to form a false impression of the source’s intentions, but can contaminate subsequent interpretation of the quote when it is restored to its original context. The author delineates this counterintuitive consequence of contextomy in an analysis of conservative politicians’ quotation of Rev. Martin Luther King in their campaigns to eliminate affirmative action programs in the US.
Framing Regent Park: the National Film Board of Canada and the construction of ‘outcast spaces’ in the inner city, 1953 and 1994
Authors: Purdy Sean
Published: June 2005

In 1953 and 1994, the National Film Board (NFB) of Canada produced two documentary films about Toronto’s Regent Park, the country’s first and largest low-income housing project. Farewell to Oak Street charted the dramatic ‘before’ and ‘after’ effects of public housing on the family, social and cultural life of the innercity dwellers whose ‘slum housing’ was demolished in the 1940s and early 1950s to make way for the pioneering housing scheme. In 1994 the NFB made Return to Regent Park. This time round, the film centred on the abject failure of Toronto’s steamrolling urban renewal plans and the efforts of activists to combat drugs, crime and the physical/social stigma of the project. This article argues that both NFB portrayals of the project contributed to the powerful moral and territorial stigmatization of inner-city workers and public housing tenants in the city.
Vita Contemplativa
Authors: Donaldson Lex
Published: June 2005

I summarize my view of organization theory and then explain how it developed over my life. I stress that it arose gradually from a series of empirical tests, so that my views are based on good reasons, despite being in some ways unconventional. Early influences upon me include the non-conformist climate of my school days and the empirical ethos at the University of Aston. I have long been interested in the creation of social science. This has been informed by the philosophy of science, which emphasizes the centrality of theory and its empirical testing. My early work in the Aston programme laid the basis for commitment to functionalism and generalization. The vociferous rejection of this style of research by ideologically oriented critics led me to defend it, both theoretically and philosophically. My later work on strategy and structure led me to reject strategic choice and embrace situational determinism. I analysed these and other research topics as being within structural contingency theory. I also used this theory frequently in my business school teaching. In the USA, newer theories arose, which, collectively, fragmented organizational theory. I critiqued these theories, and this fragmentation. Moreover, I became convinced that contingency theory in its classic variant is more correct than newer variants, and offered detailed argumentation. My empirical research also found that crises of low performance triggered adaptive structural change. From that, I created organizational portfolio theory, which draws upon finance to explain performance fluctuations and the resultant organizational change and lack of change. More recently, I offered an integrated statement of structural contingency theory and ideas for its future development theoretically and methodologically.
Technology and ethics
Authors: Shibasaki Fumikazu
Published: June 2005

‘Technology’ comes from the Greek τεχνολογία ( technologia), which in turn derives from τέχνη ( technê), meaning ‘art’ or ‘technique’, and λόγος ( logos). Modern technology has reached its present advanced level thanks to the pursuit of ever greater efficiency. In other words, technology has achieved its present level of development by changing from the quest for techniques grounded in λόγος to a form of engineering that is devoid of λόγος and merely pursues efficiency. We must not overlook the great danger in this sort of technology. Technology advancing radically and transformed into engineering devoid of λόγος cannot perceive its raison d’être and the meaning of its tasks from the perspective of the overall quest for knowledge; as a result, the process of technological development hurtles ahead blindly without a normal sense of balance. The effects on human society are immense. At this juncture we must return to the spirit of Greek τεχνολογία and urgently rebuild a technology grounded in awareness of λόγος as the wellspring of all knowledge. This is a task that we must address without delay in order to avoid the destruction of humankind.