bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular and isotopic composition of free hydrocarbon gases from Sicily, Italy
Authors: Grassa Fausto , Capasso Giorgio , Favara Rocco , Inguaggiato Salvatore , Faber Eckhard , Valenza Mariano
Published: March 2004

Chemical and isotopic data have been used as geochemical tracers for a genetic characterization of hydrocarbon gases from a total of eleven manifestations located in Eastern and Central‐Southern Sicily (Italy). The molecular analysis shows that almost all the samples are enriched in methane (up to 93.2% Vol.), with the exception of four gas samples collected around Mt. Etna showing high mantle‐derived CO2 content. Methane isotope signatures suggest that these are thermogenic gases or a mixture between thermogenic gases and microbial gases. Although samples from some mud volcanoes in Southern Sicily (Macalube di Aragona) show isotope signatures consistent with a mixing model between thermogenic and microbial, by combining the molecular compositions (C1/(C2 + C3)) and the methane isotope ratios (δ13C1), such a process seems to be excluded. Therefore, the occurrence of secondary post‐genetic processes should be invoked. Two main hypotheses have been considered: the first hypothesis includes that the gas is produced by microbial activity and altered post‐genetically by microbial oxidation of methane, while according to the second hypothesis thermogenic gas have modified their molecular ratios due to vertical migration.
A poroelastic model for the tidal modulation of seafloor hydrothermal systems
Authors: Jupp Tim E. , Schultz Adam
Published: March 2004

Time series measurements of the temperature and exit velocity of hydrothermal effluent suggest that seafloor hydrothermal systems are modulated by tidal processes. Here we apply the theory of poroelasticity to predict the magnitude and phase of tidally induced changes in the temperature and flow rate of hydrothermal effluent at the seafloor. We construct a model in which the steady state upwelling of buoyant fluid in the crust is modulated by tidal loading of a one‐dimensional seafloor by the overlying water column. The nature of the solution is controlled by the relative magnitudes of three length scales. These are (1) the depth H of the heat source below the seafloor, (2) the skin depth D over which pore pressure signals can diffuse during one tidal cycle, and (3) the advective length scale A over which the upwelling flow advects thermal signals during one tidal cycle. We consider the likely magnitude of the parameters in a real system as well as the limitations of a one‐dimensional representation of that system. We then discuss how observational data on the magnitude and phase lag of temperature and flow rate could be used to constrain the subseafloor parameters that govern hydrothermal circulation within the seafloor.
Low‐frequency excitation of length of day and polar motion by the atmosphere
Authors: de Viron Olivier , Salstein David , Bizouard Christian , Fernandez Laura
Published: March 2004

Results of a 100‐year run of the Hadley Centre general circulation model are used to compute monthly values of the three components of atmospheric torque on the Earth and of the associated atmospheric angular momentum series. All these results are compared with equivalent ones from the National Center for Environmental Prediction/National Center for Atmospheric Research reanalyses for the overlap period since 1948. We find some important differences; consequently, our results should be taken as an order of magnitude of the effect. We also compute the effect of the atmosphere on length of day (LOD) and polar motion by the use of both the torque and the angular momentum approaches. We find comparable amplitude with both torque and angular momentum for the polar motion; the axial torque, however, related to LOD, appears to be unphysical. The excitation of long‐period LOD variation is in phase with the observed variation but much smaller. The low‐frequency polar motion is only coherent with the observation at certain particular periods.
Satellite synthetic aperture radar detection of Delaware Bay plumes: Jet‐like feature analysis
Authors: Zheng Quanan , Clemente‐Colón Pablo , Yan Xiao‐Hai , Liu W. Timothy , Huang Norden E.
Published: March 2004

From the physics of radar imaging of ocean surface processes a theoretical model for the radar imaging of an ocean jet was derived. The theoretical model predicts that the jet current structure, sech2η, constitutes a determining factor for the radar image. The modeled image intensity depends on the axial velocity, decreasing as x−1 along the jet axis, and is sensitive to the wind direction with respect to the jet axis. The model was used to interpret synthetic aperture radar (SAR) images of Delaware Bay plumes taken by the RADARSAT‐1 (Canadian Radar Satellite) and ERS‐2 (European Remote Sensing satellite) satellites during a period from summer 1996 to spring 1997. In all seasons the low‐salinity plumes appear as relatively bright, jet‐like patterns on SAR images. From a morphological interpretation of the image features, both summer and winter plumes can be divided into three sections along the axis: source, jet, and dispersion region. Along the transverse direction, SAR image interpretations indicate that the plumes have a twin jet structure, which conforms to decomposition of field measurements. In summer the typical axial velocity is estimated at 6 × 10−1 m s−1 with a Reynolds number of 18. At about 5 km downstream from the source the plume behaves like a turbulent jet, and beyond that range down to about 10 km downstream, it behaves like a laminar jet. In winter the plumes become weaker than in summer. The typical axial velocity is estimated at 4 × 10−1 m s−1 with a Reynolds number of 3. The jet behaves like the laminar jet off the source down to about 4 km downstream. In both summer and winter cases the SAR images were taken at maximum flood tide, and the plumes appeared as jets. In the spring case the SAR image was taken at early flood tide; the plume appeared as an integrated body with relatively uniform bright tunes. In all cases the plume disperses within about 25 km downstream.
Wintertime/summertime contrasts of cloud condensation nuclei and cloud microphysics over the Southern Ocean
Authors: Yum Seong Soo , Hudson James G.
Published: March 2004

Wintertime/summertime contrasts of cloud condensation nuclei (CCN) and cloud microphysics observed in clean maritime environments off the west coast of Tasmania, Australia in the Southern Ocean Cloud Experiment, are presented. The average wintertime CCN concentration (NCCN) was 32 cm−3 at 1% supersaturation (S), but it was 19 cm−3 when only baseline (maritime airflow with minimal anthropogenic influences) flights were considered. In contrast, the average summertime NCCN were more than a factor of 5 higher than wintertime for all S ranges. The seasonal contrast was larger when only baseline flights were considered, especially at lower S: summertime more than an order of magnitude higher than wintertime at S below 0.1%. Corresponding cloud droplet concentrations (Nc) showed similar contrasts but to a smaller extent. Summertime average cloud droplet concentrations [Nc(ave)] were only 2.5 times higher than wintertime concentrations (70 cm−3 versus 28 cm−3). This difference was nearly a factor of 3 when only baseline flights were considered (57 cm−3 versus 20 cm−3). Flight‐average NCCN and various representations of adiabatic cloud droplet concentrations (Na) generally showed good correlations, indicating that the original effects of CCN are somehow retained in the Nc(ave). The average mean diameter (MD) of the cloud droplets was 13.9 and 17.1 μm for the summer and winter clouds, respectively. For baseline only, average MDs were 15.4 and 18.2 μm, respectively. Average MD was thus above or close to the 15‐μm threshold for drizzle production, except for the summertime nonbaseline clouds, which had an average MD smaller than 10 μm. Because of the larger droplet sizes, conversion to drizzle was more efficient in the winter clouds, where the average drizzle liquid water content (Ld) of 0.12 g m−3 was twice that of the summer Ld. The Ld for the summer nonbaseline clouds was negligible. Average Ld was also highly dependent on cloud depth. Winter baseline clouds were sometimes too thin to produce significant drizzle even though they contained very low Nc and very large MDs. The thickest clouds contained the highest Ld although their MD was not always the largest.
Validation of Multiangle Imaging Spectroradiometer (MISR) aerosol optical thickness measurements using Aerosol Robotic Network (AERONET) observations over the contiguous United States
Authors: Liu Yang , Sarnat Jeremy A. , Coull Brent A. , Koutrakis Petros , Jacob Daniel J.
Published: March 2004

Aerosol optical thickness (AOT) data retrieved by the Multiangle Imaging Spectroradiometer (MISR) in 2001 were compared with AOT measurements from 16 Aerosol Robotic Network (AERONET) sites over the contiguous United States. Overall, MISR and AERONET AOTs were strongly correlated (r = 0.73). Regression analysis showed that the root mean square error (RMSE) of MISR AOT was 0.05. The overall retrieval error of MISR AOT was within ±0.04 ± 0.18 × AOT. This result as well as the regression slope and intercept were comparable with previous results using AOT retrievals from MISR or Moderate Resolution Imaging Spectroradiometer (MODIS). The agreement between MISR and AERONET AOTs was improved (R2 = 0.90, RMSE = 0.04) when data from three western inland sites were excluded. A paired t test indicated that MISR systematically overestimated AOT by 0.02 ± 0.007. It was also shown that this positive bias in MISR AOT was greater during the spring and summer as well as in western United States. Together, these results suggest that MISR AOT measurements may be suitable for quantitative analysis of aerosol abundance. Finally, it is unlikely that the current results will vary when using alternative MISR AOT parameters since our analysis also showed the MISR AOT parameters (best fit, regional mean, and weighted regional mean AOTs) to be highly comparable.
Dynamics and chemistry of tropospheric bromine explosion events in the Antarctic coastal region
Authors: Frieß U. , Hollwedel J. , König‐Langlo G. , Wagner T. , Platt U.
Published: March 2004

We investigate chemistry and dynamics of bromine explosion events during Antarctic spring of 1999 and 2000 using ground‐based differential optical absorption spectroscopy (DOAS) observations of BrO, surface ozone, and ozone sounding measurements performed at the German research station Neumayer, located at the coast of the Antarctic continent (70°39′S, 8°15′W). BrO maps from the GOME satellite instrument show huge areas of elevated BrO above the sea ice around Antarctica, covering several thousand square kilometers. Although the Neumayer station is located at a distance of only 7 km to the coast, bromine‐activated air masses are only detected by our ground‐based DOAS instrument under particular meteorological conditions. We use trajectory calculations in high temporal and spatial resolution in combination with sea ice maps to determine the source of air masses arriving at Neumayer. A comparison of these model calculations with measurements is in very good agreement with the theory that reactive bromine is heterogeneously released by sea‐salt surfaces: in the majority of cases, enhanced levels of BrO are observed whenever a part of the probed air masses was previously in contact with sea ice surfaces, while depletion of surface ozone occurs only if the air at ground comes from the ice covered ocean. After being uplifted by advection processes, bromine‐activated and ozone‐depleted air masses are sometimes observed at high altitudes (>4000 m). This vertical transport of reactive bromine may have an impact on the free tropospheric ozone budget and on local climate in the Antarctic coastal region during springtime. BrO enhancements are usually accompanied by strong increases in light path (as detected by O4) owing to multiple scattering on aerosols, supporting the assumption that sea‐salt particles, on which BrO recycling can take place, are present at the observation site.
Transport of smoke from Canadian forest fires to the surface near Washington, D.C.: Injection height, entrainment, and optical properties
Authors: Colarco P. R. , Schoeberl M. R. , Doddridge B. G. , Marufu L. T. , Torres O. , Welton E. J.
Published: March 2004

Smoke and pollutants from Canadian forest fires are sometimes transported over the United States at low altitudes behind advancing cold fronts. An unusual event occurred in July 2002 in which smoke from fires in Quebec was observed by satellite, lidar, and aircraft to arrive over the Washington, D.C., area at high altitudes. This elevated smoke plume subsequently mixed to the surface as it was entrained into the turbulent planetary boundary layer and had adverse effects on the surface air quality over the region. Trajectory and three‐dimensional model calculations confirmed the origin of the smoke, its transport at high altitudes, and the mechanism for bringing the pollutants to the surface. Additionally, the modeled smoke optical properties agreed well with aircraft and remote sensing observations provided the smoke particles were allowed to age by coagulation in the model. These results have important implications for the long‐range transport of pollutants and their subsequent entrainment to the surface, as well as the evolving optical properties of smoke from boreal forest fires.
A Holocene record of changing Arctic Ocean ice drift analogous to the effects of the Arctic Oscillation
Authors: Darby Dennis A. , Bischof Jens F.
Published: March 2004

The Arctic Oscillation (AO) controls the configuration of the Transpolar Drift (TPD). If thicker ice from the Beaufort Gyre were exported, the volume of fresh water/sea ice in the Nordic seas would significantly increase, decreasing the formation of North Atlantic deep water. This would cool large parts of the Northern Hemisphere and affect global climate. Therefore, in order to understand how the global climate system functions, it is imperative to know how the TPD changed over the last millennium or more. The provenance of grains in a sediment core located near the confluence of the TPD and the Beaufort Gyre provides a direct proxy for changes in seaice drift owing to these circulation systems. The core has more than 200 cm of Holocene sediment, with intervals dominated by grains from the Russian shelves alternating with intervals of abundant grains from North American sources. Grains matched to Russian shelves indicate that the TPD was shifted toward North America, similar to what occurs during a more positive phase of the AO. This condition alternated with intervals where few grains matched to Russian sources, presumably because the TPD was restricted to the Russian half of the Arctic, far from the core site. During the last 1300 years, increased influx of Russian grains occurred approximately every 50–150 years. This fluctuation might represent the long‐term oscillation of the AO, which modulates the same TPD shift today.
Anisotropic evolution of small isolated vortices within the core of the Earth
Authors: Siso-Nadal F. , Davidson P. A.
Published: March 2004

In this paper we examine the evolution of a freely evolving vortex in a rotating conducting fluid. The work is motivated by the study of small-scale motion in the fluid core of the Earth where magnetic and Coriolis forces dominate over nonlinear and viscous forces. The flow is incompressible and the magnetic Reynolds number is small. Two configurations are considered: (i) the rotation axis is perpendicular to a homogeneous imposed magnetic field; (ii) the two are parallel. Large time asymptotic expressions suggest that, in the context of configuration (i), the global kinetic energy of the vortex decays algebraically on a time scale of the Joule damping time. Configuration (ii) exhibits a strong channelling of energy along the axis which leads to a slow-down of the Joule dissipation. Several initial conditions are studied by varying the initial orientation of the vortex. The characteristic shapes of the resulting flows are examined in detail and it is shown that, for Earth-like parameters, the flow evolves and decays on a time scale of days. The second part of this paper examines flows subject to continuous forcing. In particular, we discuss radiation patterns in forced rotating conducting flows. It is observed that Taylor columns are developed while magnetic effects (such as pseudodiffusion and the fracturing of vortices) shape the flow to form a series of plate-like cells orientated parallel to the magnetic and rotation axes.
The rise (and decline) of American regional science: lessons for the new economic geography?
Authors: Barnes Trevor J.
Published: March 2004

Regional science weaves in and out of the story of post-war economic geography. The vision of one man, the American economist Walter Isard, regional science represented the first systematic attempt to further joint work between geographers and economists. Within this context, the tasks of the paper are twofold. The first is to provide an interpretative history of the rise of regional science, and to a much lesser extent its decline. The interpretative framework derives from science studies, and in particular the work of Bruno Latour. The history is based on archival material and interviews. The second is to speculate briefly on the implications of both the interpretive framework used in the paper, and the history of regional science told, for the new economic geography that similarly attempts to convene discussions between economists and geographers.
Vanishing cities: what does the new economic geography imply about the efficiency of urbanization?
Authors: Anas Alex
Published: March 2004

How should the size and number of cities evolve optimally as population grows? Stripped of the constraints of geography itself, the setup of the new economic geography (NEG) implies that de-agglomeration (or de-urbanization) is efficient. The number of cities increases while the size of each decreases on the optimal path until the economy suddenly disperses to tiny towns of stand-alone firms each specializing in a unique good. The cause of this narrow result is the NEG's strong emphasis on intercity trade to satisfy the taste for more goods. For the same aggregate population, a system of smaller cities saves time lost in commuting, has a larger labor supply, and makes more goods than does a system of larger cities. Falling interurban trading costs favor this de-urbanization process. Only if intraurban commuting costs fall sufficiently, can a pattern of growing city sizes be efficient with growing population. Of course, when the number of cities or the geographic space itself is limited or asymmetric, then agglomeration can arise as an artifact of the constraints imposed by geography as demonstrated by numerous NEG models. This reveals that the central agglomerative force in the NEG is space itself and not the underlying economic relations.
Disequilibrium in the Ross of Mull Contact Metamorphic Aureole, Scotland: a Consequence of Polymetamorphism
Authors: WHEELER J. , MANGAN L. S. , PRIOR D. J.
Published: March 2004

The Ross of Mull pluton consists of granites and granodiorites and intrudes sediments previously metamorphosed at amphibolite facies. The high grade and coarse grain size of the protolith is responsible for a high degree of disequilibrium in many parts of the aureole and for some unusual textures. A band of metapelite contained coarse garnet, biotite and kyanite prior to intrusion, and developed a sequence of textures towards the pluton. In Zone I, garnet is rimmed by cordierite and new biotite. In Zone II, coarse kyanite grains are partly replaced by andalusite, indicating incomplete reaction. Coronas of cordierite + muscovite around kyanite are due to reaction with biotite. In the higher-grade parts of this zone there is complete replacement of kyanite and/or andalusite by muscovite and cordierite. Cordierite chemistry indicates that in Zone II the stable AFM assemblage (not attained) would have been cordierite + biotite + muscovite, without andalusite. The observed andalusite is therefore metastable. Garnet is unstable in Zone II, with regional garnets breaking down to cordierite, new biotite and plagioclase. In Zone III this breakdown is well advanced, and this zone marks the appearance of fibrolite and K-feldspar in the groundmass as a result of muscovite breakdown. Zone IV shows garnet with cordierite, biotite, sillimanite, K-feldspar and quartz. Some garnets are armoured by cordierite and are inferred to be relics. Others are euhedral with Mn-rich cores. For these, the reaction biotite + sillimanite + quartz → garnet + cordierite + K-feldspar + melt is inferred. Using a petrogenetic grid based on the work of Pattison and Harte, pressure is estimated at 3·2 kbar, and temperature at the Zone II–III boundary at 650°C and in Zone IV as at least 750°C.
The relationship between quality and quality cost for a manufacturing company
Authors: Omachonu Vincent K. , Suthummanon Sakesun , Einspruch Norman G.
Published: March 2004

This paper examines the components of quality cost (internal failure, external failure, appraisal cost, and prevention cost) in the context of two key manufacturing inputs, materials and machines; the concept is also explained for the company as a whole. The purpose of this research is to analyze the variables that impact quality in a manufacturing environment. There are three major findings in this research. First, there is an inverse relationship between appraisal cost plus prevention cost and failure cost. Second, the relationship between appraisal cost plus prevention cost and quality is positive. Finally, failure cost is negatively correlated with quality. This analysis also revealed a strong relationship between appraisal cost plus prevention cost and quality for material input, machine input, and the company. The results indicate that as the appraisal cost plus the prevention cost increases, quality improves and failure cost decreases.
Assessing quality costs of external failures (warranty claims)
Authors: Cauchick Miguel P.A. , Pontel Silmar
Published: March 2004

Measuring quality costs is an essential step for achieving competitiveness because these costs are strongly related to the company's annual revenue. One of the most important categories of quality costs is that of external failure costs. The consequences of these failures are not only related to the costs incurred to the failure in the field, but also to customer appeasement Within this quality cost category there are the claims against warrant. The warranty, which is a contract between a manufacturer and the consumer, specifies that the manufacturer agrees to repair or replace the failed product within the predetermined warranty period. This paper deals with the assessment of external failures by presenting a case study on warranty costs. The findings demonstrated that warranty costs can be significant and their reduction very important. In the studied case, the assessment of warranty costs has proved to be feasible and effective.
A spreadsheet‐based multiple criteria optimization framework for quality function deployment
Authors: Tang Loon‐Ching , Paoli Pierre
Published: March 2004

A new optimization model for setting the target values of the technical attributes of a product is presented. The framework not only considers customer satisfaction targets, but also the cost target. This enables one to weigh the trade‐off between these two objectives according to his preferences. The formulation is capable of generating a set of Pareto‐optimal solutions with respect to customer satisfaction and cost thus allowing the development team to explore their viability in relation to the subsequent houses of quality. At the same time, the scheme is simple enough to be implemented using a spreadsheet and the Excel solver. Uses a desirability function approach to represent the technical attributes’ values so as to adapt to different directions of improvement for different technical attributes. For illustration purposes, a case study of a digital camera is presented using a simpler variant of the model so that various sensitivity analyses can be performed.
Negotiation and resolution of conflict using AHP: an application to project management
Authors: Al‐Tabtabai Hashem M. , Thomas Varghese P.
Published: March 2004

The subject of Conflict‐Analysis and Resolution has received considerable attention in construction management. Providing measurement to tangibles and intangibles issues, involved in a conflict is not attempted often. The quantification of the perception of gains and losses for the parties involved in a conflict helps to analyze the issues scientifically, in a more logical manner. This paper presents the application of a decision‐making methodology, the analytical hierarchy process (AHP), to conflict management. The objective of this paper is analyzing and resolving conflict aided by the quantification of gains and losses using the AHP. This methodology was applied to a real conflict situation between two government agencies in Kuwait.
The Determinants of Optimal Interchange Fees in Payment Systems
Authors: Wright Julian
Published: March 2004

This paper presents a model of a card payment system as a two‐sided market that allows for partial participation by heterogeneous consumers and merchants. Taking into account the strategic effects arising from competition between merchants, the model is used to characterize the optimal structure of fees between those charged to cardholders and those charged to merchants and, more specifically, the level of the interchange fee that banks charge each other. The results modify the existing characterizations of the interchange fee, and explain the source of potential deviations between the privately and socially optimal level of the fee.
Delegation of Authority In Business Organizations: An Empirical Test
Authors: Colombo Massimo G. , Delmastro Marco
Published: March 2004

This paper tests the predictions of economic theory on the determinants of the allocation of decision‐making power through the estimates of ordered probit models with random effects. Our findings show that the complexity of plants' operations and organization, the characteristics of the communication technologies in use, the ownership status of plants and the product mix of their parent companies figure prominently in explaining whether authority is delegated to the plant manager or not. In addition, the nature of the decision under consideration turns out to affect the allocation of authority.
Costly Information Disclosure in Oligopoly
Authors: Cheong Insuk , Kim Jeong‐Yoo
Published: March 2004

We examine the effect of competition on the incentive of firms to disclose quality to consumers before trade when information disclosure is not costless. We demonstrate that no firm will disclose information in the limit, no matter how small the disclosure cost is; that is, the market outcome converges to complete concealment of information as the number of competing firms becomes larger. Nonetheless, it can be shown that under a mild condition, the equilibrium amount of information disclosure is socially excessive for any number of firms, so discouraging information disclosure by levying a tax may increase social welfare.
Competitive balance and gate revenue sharing in team sports
Authors: Szymanski Stefan , Késenne Stefan
Published: March 2004

This paper shows that under reasonable conditions, increasing gate revenue sharing among teams in a sports league will produce a more uneven contest, i.e. reduce competitive balance. This result has significant implications for antitrust authorities and legislators, who have tended to assume that revenue sharing arrangements will necessarily promote competitive balance.
HLA‐DQB1 Alleles May Influence the Surface Expression of DQ Molecules in Lymphomononuclear Cells of Type 1 Diabetes Mellitus Patients
Authors: Fernandes A. P. M. , Foss M. C. , Donadi E. A.
Published: March 2004

To evaluate the expression of human leucocyte antigen (HLA) class II (DR and DQ) molecules on lymphomononuclear cells involved in the pathogenesis of type 1 diabetes, we studied 20 patients and 20 controls matched to patients for age, sex and HLA class II profile. The coexpression of HLA and CD3, CD4, CD8, CD19 and CD14 molecules was evaluated by flow cytometry. HLA‐DRB1, ‐DQA1 and ‐DQB1 alleles were assigned using amplified DNA hybridized with sequence‐specific primers. The fluorescence intensity of HLA‐DR and ‐DQ molecules observed on the surface of the lymphomononuclear cells of patients did not differ significantly from controls. Patients presented decreased percentage of double‐positive CD4+/DQ+ cells and increased percentage of CD19+/DR+ cells, irrespective of the HLA class II profile; however, the more dramatic alteration of the lymphomononuclear phenotype profile was observed for patients possessing the HLA‐DQB1*0201 allele. These patients exhibited decreased percentage of CD3+, CD4+, CD8+, CD19+ and CD14+ cells bearing HLA‐DQ molecules and decreased fluorescence intensity for HLA‐DQ molecules on CD19+ cells compared to patients without the DQB1*0201 allele. Although type 1 diabetes patients shared CD4/DQ or CD19/DR phenotype abnormalities, patients typed as DQB1*0201 presented additional abnormalities in terms of DQ expression and cell phenotypes bearing DQ molecules.
Leishmanial Amastigote Antigen P‐2 Induces Major Histocompatibility Complex Class II‐Dependent Natural Killer‐Cell Reactivity in Cells from Healthy Donors
Authors: Nylén S. , Maasho K. , McMahon‐Pratt D. , Akuffo H.
Published: March 2004

Innate mechanisms involving natural killer cells have been implied to play an important role in immunity against Leishmania infection. Previous studies have evaluated responses to three purified amastigote antigens, P‐2, P‐4 and P‐8, of Leishmania pifanoi. The P‐4 and P‐8 antigens have been demonstrated to induce protection in mouse models, as well as to induce cellular responses in American cutaneous leishmaniasis patients. Cells from Leishmania aethiopica‐infected leishmaniasis patients preferentially responded to P‐8 and, to a lesser extent, to the cysteine proteinase, P‐2. In this study, it is shown that cells from healthy donors, including cells from truly naïve donors (cord blood), could be stimulated to proliferation and cytokine production by P‐2. The main proliferating cell types in healthy adult donors were CD16/56+ and the CD8+ cells. Blocking of major histocompatibility complex (MHC) class II with α‐MHC class II antibodies markedly inhibited proliferation and interferon‐γ (IFN‐γ) production, whereas interleukin‐10 production was not affected. Experimental evidence indicates that CD4+ cells were not necessary for the proliferative and IFN‐γ responses; however, an adherent cell population was required. Furthermore, CD16/56+ cells expressing MHC class II were expanded following P‐2 stimulation. The responses to P‐2 show a striking similarity to responses induced by the vaccine candidate Leishmania homologue of receptors for activated C‐kinase (LACK) in healthy donors. The responses described here may not be desirable when aiming at inducing protective immune responses with a vaccine, and the implications of these results for the development of vaccines against leishmaniasis are discussed.
Serum‐Soluble Selectin Levels in Patients with Rheumatoid Arthritis and Systemic Sclerosis
Authors: Ateş A. , Kinikli G. , Turgay M. , Duman M.
Published: March 2004

Soluble forms of selectins may play a regulatory role in inflammatory responses that are key to the pathophysiology of rheumatic diseases such as rheumatoid arthritis (RA) and systemic sclerosis (SSc). The aim of this study was to examine whether the elevated serum‐soluble (s) selectin levels are associated with RA or SSc. Serum sE‐, sL‐ and sP‐selectin levels were measured by sandwich enzyme‐linked immunosorbent assay in 34 RA patients, 30 SSc patients and 16 healthy subjects. The levels of sE‐selectin were significantly higher in RA and SSc patients than those in healthy subjects. The sL‐selectin level was significantly lower in RA patients compared to healthy subjects. Serum sP‐selectin levels were not significantly different among the study groups. The active RA patients had significantly higher serum sE‐ and sL‐selectin levels compared to inactive RA patients. Also, some correlations were observed between the serum selectin levels and measures of disease activity such as erythrocyte sedimentation rate and C‐reactive protein in RA patients. The higher levels of sE‐selectin were found in SSc patients with pulmonary fibrosis, and there was also a negative correlation between diffusion capacity for carbon monoxide and serum sE‐selectin. Serum levels of selectins may provide a useful additional marker for disease activity in RA patients and for disease severity in SSc patients.
Serum Mannose‐Binding Lectin Levels and mbl2 Gene Polymorphisms in Different Age and Gender Groups of Southern Chinese Adults
Authors: Ip W. K. , To Y. F. , Cheng S. K. , Lau Y. L.
Published: March 2004

Mannose‐binding lectin (MBL) is an acute‐phase serum protein, and its inherited deficiency has been shown to predispose to infections. The developmental profile of serum MBL in preterm infants has been demonstrated previously. To determine the profiles of serum MBL levels and mbl2 polymorphisms over age and genders in an adult population, samples from 689 southern Chinese (age range 16–57 years; 382 males and 307 females) were studied using enzyme‐linked immunosorbent assay and high‐throughput genotyping of mbl2. Serum MBL levels maintained within a narrow range from age groups of 16–20 years old to 31–40 years old (mean of 2050–2160 µg/l) and declined to a mean of 1466 µg/l in the last age group 41–57 years old. No significant differences were found in the distributions of mbl2 haplotypes (YA, XA and YB) among all these age groups. Between gender groups, no significant imbalance of MBL profile in terms of serum MBL levels and distribution of mbl2 haplotypes was found. Results suggest an important role of circulating MBL in first‐line host defence because MBL maintains at fairly constant levels after childhood and no gender influence on the MBL profile.
Antibodies Raised Against the Second Extracellular Loop of the Human Muscarinic M3 Receptor Mimic Functional Autoantibodies in Sjögren's Syndrome
Authors: Cavill D. , Waterman S. A. , Gordon T. P.
Published: March 2004

Functional antimuscarinic M3 receptor (M3R) autoantibodies have been shown to inhibit cholinergic neurotransmission at the postsynaptic level and appear to mediate parasympathetic dysfunction, including sicca symptoms in Sjögren's syndrome (SS). The precise epitope(s) involved in the inhibition of M3R‐mediated cholinergic neurotransmission has not been defined. In this study, an active immunization approach to raise antibodies with functional activity against the second extracellular loop of the M3R was used and their functional properties were compared with those of human autoantibodies. Peptides corresponding to the second extracellular loop of the M3R were used as immunogens in rabbits, and antisera were tested for inhibition of carbachol‐evoked colon smooth muscle contraction in parallel with immunoglobulin G from a patient with SS. Anti‐M3R antibodies were affinity purified on a peptide representing a dominant functional epitope at the COOH terminus of the second extracellular loop of the M3R and tested for concentration‐dependent inhibition. Experimentally raised anti‐M3R antibodies, like the human autoantibodies, showed concentration‐dependent and noncompetitive inhibition of carbachol‐evoked colon contractions. Inhibitory activity was detected by functional assays at concentrations as low as 3 ng/ml, which was below the threshold of detection of antibody by peptide enzyme‐linked immunosorbent assay. It is concluded that the experimentally raised anti‐M3R antibodies share the functional properties of autoantibodies in patients with SS.
Involvement of Interleukin‐1β in Systemic Morphine Effects on Paw Oedema in a Mouse Model of Acute Inflammation
Authors: Pourpak Z. , Ahmadiani A. , Alebouyeh M.
Published: March 2004

Recent studies suggest that peripheral morphine may represent a valuable treatment in acute inflammatory painful diseases through peripheral or central mechanisms. In the present study, anti‐inflammatory effects of systemic morphine on carrageenan‐induced hind paw oedema were examined in a model of peripheral acute oedema in mice. Carrageenan induced a time‐dependent inflammation that was maximal 3 h after administration. While intraperitoneal administration of morphine sulfate at a low dose (1 mg/kg) increased carrageenan‐induced hind paw oedema, intraperitoneal injection of morphine sulfate at a high dose (7 mg/kg) resulted in significant anti‐inflammatory effects on carrageenan‐induced hind paw oedema. These anti‐inflammatory effects were blocked by pretreatment with naloxone. Measuring the serum levels of interleukin‐1β revealed that increases in serum levels of this cytokine were involved in morphine anti‐inflammatory effects. Pretreatment with naloxone decreased interleukin‐1β serum levels near to those of control group. In conclusion, these data demonstrate that morphine produced pro‐ or anti‐inflammatory effects in a dose‐dependent manner through peripheral or central mechanisms. The observed anti‐inflammatory effects may be due to an increase in the cytokine production and/or release by host immune systems.
Interaction of Human Immunoglobulin G with CD16 on Natural Killer Cells: Ligand Clearance, FcγRIIIA Turnover and Effects of Metalloproteinases on FcγRIIIA‐Mediated Binding, Signal Transduction and Killing‡
Authors: Mota G. , Moldovan I. , Calugaru A. , Hirt M. , Kozma E. , Galatiuc C. , Brasoveanu L. , Boltz‐Nitulescu G.
Published: March 2004

Human natural killer (NK) cells express low‐affinity Fc immunoglobulin G (IgG) receptor (FcγRIIIA/CD16). The binding of monomeric IgG (mIgG) and F(ab′)2 fragments of 3G8 anti‐CD16 monoclonal antibody (mAb) to FcγRIIIA was investigated by flow cytometry. Over 90% of NK cells bound endogenous IgG, and during incubation at 37 °C, the FcγRIIIA occupancy decreased slowly. Approximately 90% of NK cells bind mIgG or F(ab′)2 fragments of 3G8 anti‐CD16 mAb. The calculated half‐time (T1/2) of in vitro mIgG dissociation from FcγRIIIA was 130 min. By cross‐linking the mIgG ligand with F(ab′)2 fragments of anti‐human IgG antibody, the T1/2 decreases to 85 min. In kinetics study, it has been shown that 125I‐mIgG bound to FcγRIIIA is slowly released in the culture supernatant, maybe eluted at acid pH, or partially internalized and degraded. The binding of IgG to FcγRIIIA was increased by 53.8% on cells cultured in the presence of RU36156, a matrix metalloproteinase (MMP) inhibitor. Furthermore, an increase in phosphorylation of Lyn tyrosine kinase, after cross‐linking of mIgG‐FcγRIIIA complex, was observed on NK cells treated with RU36156. When the FcγRIIIA was occupied by mIgG, the capacity of NK cells to kill K562 target cells was decreased by RU36156, because the MMP inhibitor protects CD16 from proteolysis. Our data demonstrate that binding of mIgG to human NK cells is followed by ligand dissociation and/or internalization, enzymatic degradation and exocytosis. The RU36156 MMP inhibitor protects FcγRIIIA from cleavage, augments NK‐cell activation and may interfere in their killing capacity.
Blocking CC Chemokine Receptor (CCR) 1 and CCR5 During Herpes Simplex Virus Type 2 Infection In Vivo Impairs Host Defence and Perturbs the Cytokine Response
Authors: Sørensen L. N. , Paludan S. R.
Published: March 2004

Elimination of viral infections is dependent on rapid recruitment of leucocytes to infected areas. Chemokines constitute a class of cytokines that regulate migration of leucocytes to sites of infection. In this work, the expression and function of CC chemokine receptor (CCR)1 and CCR5 and their ligands during a generalized herpes simplex virus type 2 (HSV‐2) infection in mice were studied. Many CCR1 and CCR5 ligands were expressed in infected organs after intraperitoneal infection. In particular, CC chemokine expression in the liver preceded the expression of CCR1 and CCR5, suggesting recruitment of cells bearing these receptors, which correlated with a decrease in viral titres. Administration of Met‐RANTES, a CCR1 and CCR5 antagonist, led to impaired antiviral response with significantly higher viral titre in the liver on days 1 and 6 after infection. This observation was accompanied by a decreased and shortened recruitment of natural killer cells to the peritoneum of infected mice treated with the antagonist. Despite this reduced recruitment of antiviral leucocytes in mice receiving Met‐RANTES, peritoneal cells from these mice produced markedly enhanced levels of pro‐inflammatory cytokines. Altogether, the results suggest that CCR1 and/or CCR5 are important for both viral clearance and eventual control of the immune response.
Additive Effects of Leflunomide and Tacrolimus in Prevention of Islet Xenograft Rejection
Authors: Zhang L. , Qi Z. , Wu D. , Shan S. , Ekberg H.
Published: March 2004

Leflunomide is a low molecular weight immunosuppressive drug which inhibits the enzymes dehydroorotate dehydrogenase and protein tyrosine kinase, both of which are important components in the immune response. As the mechanisms of action of leflunomide and tacrolimus are different, we postulated an additive or synergistic effect of the two drugs and investigated the effects of leflunomide alone, or in combination with a suboptimal dose of tacrolimus, on xenogeneic islet transplantation in a rat‐to‐mouse model. A total of 1200–1500 rat islets were transplanted under the left kidney capsule of streptozotocin‐induced diabetic BALB/c mice. The median survival time (MST) of the untreated group was 6 days. Leflunomide at 5, 10 and 20 mg/kg/d administrated for 10 days significantly prolonged MST to 10, 16 and 20 days. A dose of tacrolimus (2 mg/kg/d) was associated with a graft survival of 9 (range 6–12) days; most grafts rejected during ongoing therapy. When tacrolimus (2 mg/kg/d) was combined with leflunomide (10 mg/kg/d), the survival time of the islet xenografts was increased further to 22 days, significantly longer than with leflunomide or tacrolimus alone. In summary, our findings demonstrate that leflunomide prolonged xenogeneic islet graft survival, and that its immunosuppressive effect was improved when combined with tacrolimus.
Supporting community solutions to family violence
Authors: Taylor Judy , Cheers Brian , Weetra Colin , Gentle Ian
Published: March 2004

Competing discourses have always figured prominently in policy debates about violence against women and children. Legislation and services to address it have largely been developed from theory and empirical knowledge of domestic violence occurring in intimate relationships. Knowledge from an Indigenous perspective about family violence, embedded in a context of colonisation and involving a broader range of relationships, has been less influential. One of the consequences of this is that when Indigenous communities identify solutions to address family violence holistically, these solutions are difficult to implement. Research with a remote South Australian Aboriginal community, looking for ways to reduce the level of family violence, resulted in new understandings of it. Linking issues of economic deprivation, dispossession and the breaking down of culture, the community devised a holistic community development approach to reduce family violence.

This paper identifies the waves of understanding about family violence and argues that community‐initiated solutions must be supported by policy and funding options based on an Indigenous understanding of family violence.
Laminin‐2 stimulates the proliferation of epithelial cells in a conjunctival epithelial cell line
Authors: Dowgiert J. , Sosne G. , Kurpakus‐Wheater M.
Published: March 2004

Abstract.  Laminin‐2 (LN‐2, α2β1γ1) is a basement membrane‐associated laminin isoform usually considered in the context of muscle and nerve tissues. To test the hypothesis that LN‐2 can additionally modulate epithelial cell biology, an analysis of the role of LN‐2 in cell adhesion, activation of signalling intermediates and proliferation was undertaken. A virally transformed human conjunctival epithelial cell line (HC0597) was utilized in this study. Adhesion assays using function‐inhibiting antibodies demonstrated that α3β1 integrin is essential for the rapid attachment of conjunctival epithelial cells to LN‐2. Bromodeoxyuridine (BrdU) incorporation analyses revealed that, compared with LN‐1 or LN‐10, LN‐2 significantly promotes epithelial proliferation. Phosphorylation of the signalling intermediates Erk1/2 and Akt‐1 was observed within 15 min of cell adhesion to LN‐2. Inhibiting α3β1 integrin function decreased total cellular phosphotyrosine levels, specifically inhibited phosphorylation of Erk1/2 and Akt‐1, and dampened the proliferation response of epithelial cells adherent to LN‐2. Inhibition of Erk or Akt activation inhibited cell proliferation in a dose‐dependent manner. However, the inhibition of Erk resulted in a stronger suppression of proliferation compared with Akt inhibition. From these results, it is concluded that human conjunctival epithelial cells adhere to immobilized LN‐2 using α3β1 integrin. α3β1 integrin/LN‐2 signalling, transduced primarily through an Erk pathway, enhances epithelial cell proliferation. These results demonstrate that LN‐2 can impact on epithelial cell biology in addition to nerve and muscle, and provide information regarding the role of this isoform in ocular surface epithelial cells.
Activation, isolation, identification and in vitro proliferation of oval cells from adult rat livers
Authors: He Z. P. , Tan W. Q. , Tang Y. F. , Zhang H. J. , Feng M. F.
Published: March 2004

Abstract.  Oval cells, putative hepatic stem cells, could potentially provide a novel solution to the severe shortage of donor livers, because of their ability to proliferate and differentiate into functional hepatocytes. We have previously demonstrated that oval cells can be induced to differentiate into cells with morphologic, phenotypic, and functional characteristics of mature hepatocytes. In this study, we have established a new model combining ethionine treatment with partial hepatectomy to activate oval cells, then developed a procedure utilizing selective enzymatic digestion and density gradient centrifugation to isolate and purify such cells from heterogeneous liver cell population. We identified oval cells by their morphological characteristics and phenotypic properties, thereby providing definitive evidence of the presence of hepatic stem‐like cells in adult rat livers. Viewed by transmission electron microscopy, they were small cells with ovoid nuclei, a high nucleus/cytoplasm ratio and few organelles, including mitochondria and endoplasmic reticulum. Flow cytometric assay showed that these cells highly expressed OV‐6, cytokeratin‐19 (CK‐19) and albumin. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis displayed that the freshly isolated cells co‐expressed albumin, cytokeratin‐7 (CK‐7) and CK‐19 mRNA, indicating that they were essentially bipotential hepatic stem‐like cells. Furthermore, we set up a culture system containing growth factors and a fibroblast feeder layer, to provide nourishment to these cells. Thus, we were able to culture them in vitro for more than 3 months, with the number of cells doubling 100 times. Gene expressions of albumin, CK‐7 and CK‐19 in the cells derived from the expanding colonies at day 95 were confirmed by RT‐PCR analysis. These data suggested that the hepatic oval cells derived from adult rat livers possess a high potential to proliferate in vitro with a large increase in number, while maintaining the bipotential nature of hepatic stem cells.