bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aqueous exposure and uptake of arsenic by riverside communities affected by mining contamination in the Río Pilcomayo basin, Bolivia
Authors: Archer J. , Hudson-Edwards K. A. , Preston D. A. , Howarth R. J. , Linge K. 
Published: December 2005

AbstractThe headwaters of the Río Pilcomayo drain the Cerro Rico de Potosí precious metal-polymetallic tin deposits of southern Bolivia. Mining of these deposits has taken place for around 500 years, leading to severe contamination of the Pilcomayo's waters and sediments for at least 200 km downstream. Communities living downstream of the mines and processing mills rely on the river water for irrigation, washing and occasionally, cooking and drinking, although most communities take their drinking water from springs located in the mountains above their village. This investigation focuses on arsenic exposure in people living in riverside communities up to 150 km downstream of the source. Sampling took place in April–May 2003 (dry season) and was repeated in January–March 2004 (wet season) in five communities: El Molino, Tasapampa, Tuero Chico, Sotomayor and Cota. Cota was the control in 2003 and again in 2004; a nearby city, Sucre, and several locations in the UK were also used as controls in 2004. Drinking, irrigation and river waters, hair and urine samples were collected in each community, digested where appropriate and analysed for As using ICP-MS. Arsenic concentrations in drinking waters ranged 0.2–112 μg 1–1, irrigation water 0.6–329 μg 1–1, river waters 0.9–12,800 μg 1–1, hair 37–2110 μg kg–1 and urine 11–891 μg 1–1. All but one drinking water sample was found to contain As below the World Health Organization recommended guideline of 10 μg 1–1, although a number of irrigation and river water concentrations were above Canadian and Bolivian guidelines. Many As concentrations in the hair and urine samples from this study exceeded published values for non-occupationally exposed subjects. Analysis of mean concentration values for all media types showed that there were no statistically significant differences between the control locations and the communities exposed to known As contamination, suggesting that the source of As may not be mining-related. Arsenic concentration appears to increase as a function of age in hair samples from males and females older than 30 years. Male volunteers over the age of 35 showed increasing urine-As concentrations as a function of age, whereas the opposite was true for the females.
Electrokinetic generation of reactive iron-rich barriers in wet sediments: implications for contaminated land management
Authors: Faulkner D. W. S. , Hopkinson L. , Cundy A. B. 
Published: December 2005

AbstractHere we describe preliminary research into the in situ electrokinetic generation of continuous iron-rich precipitates to act as sub-surface barriers for the containment of contaminated sites. This is achieved using sacrificial iron electrodes emplaced either side of a soil/sediment mass to introduce iron into the system, and their dissolution and re-precipitation under the influence of an applied (DC) electric field. Continuous vertical and horizontal iron-rich bands (up to 2 cm thick) have been generated over a timescale of 300—500 h, at voltages of <5 V with an electrode separation of between 15 and 30 cm. The thickness of the iron-rich band increases as the applied voltage is increased. Geotechnical tests in sand indicate that the iron-rich band produced is practically impervious (coefficient of permeability of 10—9 ms—1 or less), and has significant mechanical strength (unconfined compressive strength of 10.8 N mm—2). By monitoring the current, the integrity of the iron-rich band may be assessed, and by continued application of current, the barrier may 'self heal'. The iron-rich barrier is composed of amorphous iron, goethite, lepidocrocite, maghemite and native iron.
Redox processes in a eutrophic coal-mine lake
Authors: Roman-Ross G. , Charlet L. , Tisserand D. , Glemme M. 
Published: December 2005

AbstractThe water column chemistry of lake St Eloy (St Eloy-les Mines, Allier, France) was monitored over a period of a year. This is a small stratified lake created by subsidence of an underground coal mine. The results show a permanent stratification and the development of two water bodies with contrasting chemistry. The superficial oxic layer (i.e. the upper 5 m) is of high water quality and the water, not affected by seasonal changes, is suitable as a source of drinking water. In contrast, the deeper layer is permanently anoxic and the waters have a conductivity which is six times greater than in the epilimnion. Due to density difference and the small size of the lake, no turn-over occurs and all elements that diffuse from bottom sediments are strongly concentrated in the hypolimnion. Arsenic concentrations are very low in the epilimnion, but they increase quickly with depth below the oxycline, to reach up to 7 μm below 8 m depth. Different solid phases could control the fate of arsenic in this lake such as gypsum for As(V) in the hypolimnion, mackinawite for As(V) and As(III) in the hypolimnion, and close to the oxycline, Fe(III) oxyhydroxides are possible hosts for both As(III) and As(V).
Hydrochemical associations and depth profiles of arsenic and fluoride in Quaternary loess aquifers of northern Argentina
Authors: Warren C. , Burgess W. G. , Garcia M. G. 
Published: December 2005

AbstractArsenic and fluoride in groundwater from Quaternary loess deposits in Argentina pose major health concerns. Common sources for arsenic and fluoride have been suggested but the processes of mobilization are disputed, and distributions in groundwater are largely unresolved at a sample density >1/50 km2. At Los Pereyras in Tucumán Province, northern Argentina, we have evaluated distributions and hydrochemical associations of arsenic and fluoride with a sample density of 0.75 per km2 over an area of 75 km2, to a depth of 230 m. Groundwater in the loess is oxic and alkaline. Fluoride is restricted to the upper 20 m of the Quaternary loess, where it reaches 8.3 mg/1. Arsenic has a vertical layering consistent with that of fluoride, ranging from 20 to 760 μg/1 in the upper 20 m and 58—163 μg/l below this. There are two sources of arsenic, one unrelated to the fluoride source. Positive correlations between arsenic and fluoride with pH, but not with alkalinity, support desorption from iron oxyhydroxides as the likely mechanism of release to groundwater for arsenic and fluoride, rather than the weathering of silicate minerals. Stratigraphic and/or palaeohydrological controls may explain the observed depth distributions within the loess aquifer.
Arsenic-bearing smectite from the geothermal environment
Authors: Pascua C. , Charnock J. , Polya D. A. , Sato T. , Yokoyama S. , Minato M. 
Published: December 2005

AbstractArsenic-rich scales are widely associated with geothermal fields and constitute a potential hazard to human health. Such arsenic has hitherto been reported to be almost exclusively hosted by sulphide or oxide phases or occurring as surface species. We report here, however, the occurrence of an arsenic-rich (1500 to 4000 mg kg—1 As) smectite from geothermal precipitates from a geothermal field in northwestern Japan and present evidence that the arsenic is predominantly hosted within this silicate mineral.Consistently ∼80% of the total arsenic determined in these geothermal precipitates was found by selective chemical extractions to be associated with an operationally defined clay mineral fraction, with lesser proportions being associated with operationally defined amorphous silica, Fe oxide and sulphide fractions. Analysis by XRD, ATR IR and XRF showed the clay fraction to be dominated by Mg-rich trioctahedral smectite.Arsenic K-edge XAS spectra of the smectite suggested the dominance of As(III)-O coordinated species with significant contributions from As(V)-O coordinated species. Both XPS and a magnesium chloride chemical extraction indicated minimal adsorption of arsenic on smectite surfaces suggesting that the arsenic was predominantly either dissolved within the smectite or occurred within mineral occlusions. No such occlusions greater than 1 μm in size were observed in the As-rich smectites.The potential occurrence of arsenic-bearing clays should be considered when determining remediation strategies for geothermal environments or evaluating risks associated with the industrial usage of geothermal precipitates.
A Method to Predict the Heat Generation in a Rubber Spring Used in the Railway Industry
Authors: Luo R K , Wu W X , Mortel W J 
Published: December 2005

An integrated real-time simulation and experimental programme has been carried out on an anti-vibration part used in the railway industry. This work, which was done at the authors' Technical Centre, was designed to ensure that any temperature rise inside an anti-vibration part does not exceed the design requirement in accelerated fatigue tests. Real-time simulation and testing have the advantages of giving the maximum temperature change when an anti-vibration component reaches a steady state and the time duration for each stage of the whole process. It is found from both testing and simulation that the energy loss per cycle of the rubber spring, under fixed dynamic amplitude, does not depend on the loading frequency. Therefore, the energy loss per cycle can be more easily obtained using a conventional quasi-static loading procedure, to reduce the cost and the time, than from conducting more complicated dynamic tests. Key rubber parameters obtained from the authors' material testing laboratory are presented here as important references for similar applications in railway industries. It is shown that this methodology is reliable and can be used to evaluate the temperature effects caused by dynamic loading.
Development of a Methodology to Calculate Stresses in Track Components
Authors: Naudé F P , Fröhling R D , Theron N J 
Published: December 2005

The analytical model being used by Spoornet to calculate rail stresses on railway track for the past three decades was revisited and improved. The modifications include the incorporation of current best practices and presenting the engineer with guidelines on how to determine input parameters, which are normally difficult to obtain. The most sensitive parameters were investigated, and experimental results, as well as modern modelling methods, were used to establish nominal input values and guidelines for determining such values. The improved analytical model provides engineers with a suitably accurate tool for calculating rail and track component stresses, without the need to build detailed models of the track under investigation.
A comparative study between ciliary count and the degree of opacity of paranasal sinus CT scans in chronic sinusitis pre and post FESS
Authors: Bassiouny Ahmed , Abd El Raouf Mahmoud , Atef Ahmed , Nasr Safaa , Talaat Soha , Nasr Magdy , Ayad Essam 
Published: December 2005

Objective: To investigate the relationship between the extent of sinus disease in chronic sinusitis as detected radiologically by computed tomography (CT) scan and the population of cilia (ciliary area) both before and after functional endoscopic sinus surgery (FESS). In a simple way this is a trial to statistically prove that the CT scan could be a valid indicator and a mirror of the histological status of the sinus mucosa.Design: Twenty adult patients were enrolled in this study. Radiological extension of the sinus disease was quantitated using the classification proposed by Kennedy in 1992 and the ciliary population was studied using scanning electron microscopy and image analysis softwares.Results and conclusion: The more advanced the sinusitis, as evidenced by CT scans, the more the expected reduction in the ciliary area (CA) and in the ciliary count. But after FESS the degree of ciliary regeneration does not depend statistically on the radiological condition of the sinuses and the degree of opacity prior to intervention, i.e. a statistically valid inverse relationship exists between the radiological stage of sinusitis and the ciliary population pre-operatively but the same relation does not extend to the ciliary population post-operatively.
Radiophonosurgery of benign superficial vocal fold lesions
Authors: Ragab Sameh M , Elsheikh Mohamed N , Saafan Magdy E , Elsherief Sayed G 
Published: December 2005

Objective: To conduct a prospective randomized controlled trial describing and investigating the efficacy and safety of radiosurgical excision of benign superficial vocal fold lesions.Materials and methods: Fifty patients with benign superficial vocal fold lesions (20 vocal nodules, 27 vocal polyps and three Reinke’s oedema) who failed conservative therapy were included in the study. They were equally randomized into cold knife or radiosurgical excision. Clinical and voice assessments were done pre-operatively and after surgery. Voice analysis included a subjective visual analogue scale (VAS) and a perceptual assessment with a simplified version of the GRBAS scale (GRB) consisting of G (grade), R (roughness), and B (breathiness). Acoustic voice evaluation included jitter and shimmer. Post-operative voice therapy was provided for all patients. Complications, smoothness of post-operative recovery, and administration of analgesia were reported.Results: Both groups experienced significant improvement in VAS, perceptual evaluation and acoustic analysis after surgery, with no evidence of significant differences between the cold knife and radiofrequency groups. The radiofrequency group showed a decrease of 17 per cent in the mean operative time when compared with the cold knife group, but this was not statistically significant. No evidence of a significant difference was noticed in the smoothness of post-operative recovery, administration of analgesia and complication rate.Conclusion: Radiophonosurgery opens a new therapeutic approach for patients with benign superficial vocal fold lesions. It combines the advantages of both cold knife and laser phonosurgery, being easy, safe, precise and effective, and having excellent tactile and haemostatic properties.
End‐group modified poly(methyl vinyl ether): Characterization and LCST demixing behavior in water
Authors: Van Durme Kurt , Van Mele Bruno , Bernaerts Katrien V. , Verdonck Beatrice , Du Prez Filip E. 
Published: December 2005

AbstractA range of hydrophilic poly(methyl vinyl ether) (PMVE) polymers was synthesized by living cationic polymerization of methyl vinyl ether (MVE), having different hydrophilic or hydrophobic chain‐end functionalities. The dissimilar end‐groups were either introduced by end‐capping of the growing polymer chain with LiBH4, methanol, and water or by functional initiation with 2‐bromo‐(3,3‐diethoxy‐propyl)‐2‐methylpropanoate. The synthesized PMVEs were characterized by 1H NMR, size exclusion chromatography, and matrix‐assisted laser desorption ionization time of flight, displaying a narrow polydispersity. Modulated temperature DSC was applied to study the influence of the nature of the end‐groups on the solubility behavior of PMVE in water. Terminal‐modification with a hydroxyl function improves the solubility, whereas a Br‐containing end‐group causes the polymer to be insoluble in water at room temperature; however, the special type III lower critical solution temperature demixing behavior being maintained. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 461–469, 2006
Differential impact of semaphorin 3E and 3A on CNS axons
Authors: Steffensky Marion , Steinbach Karin , Schwarz Uli , Schlosshauer Burkhard 
Published: December 2005

AbstractDuring the development of the central nervous system (CNS), the correct wiring of outgrowing neurites is mediated by antagonistic mechanisms. Aberrant growth is prevented by repulsive factors such as semaphorins. Expression of the ligands Sema3A and ‐3E and the receptors neuropilin Npn‐1, ‐2a and ‐2b in the chick visual system were analyzed by RT‐PCR. Whereas Sema3A and its major receptor Npn‐1 were abundant, Sema3E and Npn‐2 isoform expression was highly restricted and developmentally regulated. Peak expression occurred during retinal axon innervation of the tectum. Functional in vitro assays with recombinant proteins revealed a topography‐specific growth cone collapsing activity of Sema3A for tectal axons. Interestingly, whereas tectal axons collapsed in a topographic‐specific manner only in the presence of Sema3A, retinal axons responded only to Sema3E. The collapsing activity was intracellularly mediated by cGMP. For a detailed analysis of neuronal responses to sempahorins, time lapse video recording was performed. When tectal and retinal axons were pre‐exposed to brain‐derived neurotrophic factor (BDNF), a protective effect was evident only in the case of retinal axons. Our results suggest a molecular mechanism whereby ingrowth of retinal axons into the tectum can be regulated by Sema3E/BDNF modulation without disturbing tectal axon growth out of the tectum mediated by Sema3A.
Energy Fluxes due to the Surface and Internal Tides in Knight Inlet, British Columbia
Authors: Stacey Michael W. , Pond S. 
Published: December 2005

Abstract
A laterally integrated (two dimensional) nonlinear numerical model is used to examine the flux of M2 tidal energy in Knight Inlet. The simulated flux of tidal energy into the inlet is somewhat smaller than that estimated using the change in phase of the M2 tidal height along the inlet, a method that does not account for the effect of the internal tide on the surface elevation. The simulated energy flux into the inlet is close to the energy flux of the internal tide away from the sill determined from observations using an acoustic Doppler current profiler (ADCP). The net flux due to the internal tide is significantly less than (&lt;1/2 of) the rate at which energy is removed from the surface tide. Earlier linear models of the internal tide produced energy fluxes that agreed with those estimated from the phase change of the tidal height but were larger than the fluxes that could be found in the observations. The reason for this discrepancy is not that these simple models neglected nonlinear effects, but rather that they did not take reflections of the internal tide into account. Also, the simulated flux of energy into the inlet less the net flux of internal tidal energy away from the sill is about equal to the simulated dissipation within 2 km on either side of the sill. The simulated net flux of internal tidal energy away from the sill is in agreement with the flux determined from the ADCP observations on the downinlet side of the sill, but not on the upinlet side of the sill. A possible explanation is that only the first internal mode (which is surface intensified) was important on the downinlet side but the first three internal modes were important on the upinlet side. The flux calculation using the ADCP observations took variations in the inlet width into account but did not take depth variations into account; thus, the reflection coefficients of the second and third modes may have been underestimated.
Experiments and Simulations on Coastal Flows in the Presence of a Topographic Slope
Authors: Sansón L. Zavala , Serravall R. , Carnevale G. F. , van Heijst G. J. F. 
Published: December 2005

Abstract
The evolution of a barotropic coastal current in the presence of a bottom ramp-shaped topography is studied by means of laboratory experiments and numerical simulations. The experiments are performed in a rectangular rotating tank filled with freshwater. The fluid depth is shallow at one side of the domain and deeper at the other side, and both regions are divided by a narrow slope, whose depth contours are perpendicular to the long sides of the tank. A current approaching the slope is produced along one of the vertical walls, having the boundary at its right. Two configurations are analyzed: when the current flows from shallow to deep water and when flowing in the opposite direction. In the first scenario, the current is divided in two parts, one of them following the coastline. The other part of the current pairs with a cell of negative relative vorticity generated at the slope due to squeezing effects, forming a dipolar structure moving offshore, back toward the shallow side. In addition, a weak current moving inshore along the slope is clearly formed. In the second configuration, when the flow goes from deep to shallow water, a part of or even the whole current might be forced to move along the contours of the topography, away from the coast. In this case there is no dipole formation. The experiments are well reproduced by means of quasigeostrophic numerical simulations, which allow a more detailed systematic study of the influence of flow parameters such as the topography height and the width of the slope.
Bispectral Analysis of Energy Transfer within the Two-Dimensional Oceanic Internal Wave Field
Authors: Furuichi Naoki , Hibiya Toshiyuki , Niwa Yoshihiro 
Published: December 2005

Abstract
Bispectral analysis of the numerically reproduced spectral responses of the two-dimensional oceanic internal wave field to the incidence of the low-mode semidiurnal internal tide is performed. At latitudes just equatorward of 30°, the low-mode semidiurnal internal tide dominantly interacts with two high-vertical-wavenumber diurnal (near inertial) internal waves, forming resonant triads of parametric subharmonic instability (PSI) type. As the high-vertical-wavenumber near-inertial energy level is raised by this interaction, the energy cascade to small horizontal and vertical scales is enhanced. Bispectral analysis thus indicates that energy in the low-mode semidiurnal internal tide is not directly transferred to small scales but via the development of high-vertical-wavenumber near-inertial current shear. In contrast, no noticeable energy cascade to high vertical wavenumbers is recognized in the bispectra poleward of ∼30° as well as equatorward of ∼25°. A new finding is that, although PSI is possible equatorward of ∼30°, the efficiency drops sharply as the latitude falls below ∼25°. At all latitudes, another resonant interaction suggestive of induced diffusion is found to occur between the low-mode semidiurnal internal tide and two high-frequency internal waves, although bispectral analysis shows that this interaction plays only a minor role in cascading the low-mode semidiurnal internal tide energy.
The "Relative Universality" of Human Rights: An Assessment
Authors: On Steve 
Published: December 2005

AbstractThis essay makes an assessment of Jack Donnelly's model of overlapping consensus on the Universal Declaration of Human Rights. It raises key questions, such as: How to adjudicate competing rights; what is to become of "unreasonable" views; whence come reasonable views; and, beyond the obvious cases of slavery and genocide, how is the overlapping consensus obtained? While an alternative theory is not developed, a critical perspective is provided that might facilitate further inquiries.
The United Nations and International Security in the New Millennium
Authors: Knight W. Andy 
Published: December 2005

AbstractThe end of the Cold War opened a window of opportunity for the United Nations to play a greater role in international security than it was allowed to play in the midst of the ideological conflict between the United States and the former Soviet Union. However, the expected "peace dividend" never materialized in the post-Cold War period. Instead, a number of civil conflicts erupted and new threats to security, particularly to human security, emerged. This chapter critically examines the evolution of the UN's role in addressing international security problems since 1945, including global terrorism. It also outlines recent attempts by the world body, through extension of its reach beyond the territorial constraints of sovereignty, to build sustained peace through preventive measures and protect human security globally.