bluuebunny/crossref_metadata_2025_split huggingface dataset:
pH dependence of iron photoreduction in a rocky mountain stream affected by acid mine drainage
Authors: McKnight Diane M. , Kimball Briant A. , Runkel Robert L. 
Published: September 2002

AbstractThe redox speciation of dissolved iron and the transport of iron in acidic, metal‐enriched streams is controlled by precipitation and dissolution of iron hydroxides, by photoreduction of dissolved ferric iron and hydrous iron oxides, and by oxidation of the resulting dissolved ferrous iron. We examined the pH dependence of these processes in an acidic mine‐drainage stream, St Kevin Gulch, Colorado, by experimentally increasing the pH of the stream from about 4·0 to 6·5 and following the downstream changes in iron species. We used a solute transport model with variable flow to evaluate biogeochemical processes controlling downstream transport. We found that at pH 6·4 there was a rapid and large initial loss of ferrous iron concurrent with the precipitation of aluminium hydroxide. Below this reach, ferrous iron was conservative during the morning but there was a net downstream loss of ferrous iron around noon and in the afternoon. Calculation of net oxidation rates shows that the noontime loss rate was generally much faster than rates for the ferrous iron oxidation at pH 6 predicted by Singer and Stumm (1970. Science 167: 1121). The maintenance of ferrous iron concentrations in the morning is explained by the photoreduction of photoreactive ferric species, which are then depleted by noon. Copyright © 2001 John Wiley & Sons, Ltd.
Neural network linear forecasts for stock returns
Authors: Kanas Angelos 
Published: September 2002

AbstractWe examine the out‐of‐sample performance of monthly returns forecasts for the Dow Jones and the FT, using a linear and an artificial neural network (ANN) model. The comparison of out‐of‐sample forecasts is done on the basis of directional accuracy, using the Pesaran and Timmermann (1992. A simple nonparametric test of predictive performance, Journal of Business and Economic Statistics 10: 461–465) test, and forecast encompassing, using the Clements and Hendry (1998. Forecasting Economic Time Series. Cambridge University Press: Cambridge, UK) approach. While both models perform badly in terms of predicting the directional change of the two indices, the ANN forecasts can explain the forecast errors of the linear model while the linear model cannot explain the forecast errors of the ANN for both indices. Thus, the ANN forecasts are preferable to linear forecasts, indicating that the inclusion of nonlinear terms in the relation between stock returns and fundamentals is important in out‐of‐sample forecasting. This conclusion is consistent with the view that the underlying relation between stock returns and fundamentals is nonlinear. Copyright © 2001 John Wiley & Sons, Ltd.
A stereo vision system for the inspection of IC bonding wires
Authors: Ye Q. Z. , Ong S. H. , Han X. 
Published: September 2002

AbstractWe describe a novel inspection system based on the application of the stereo technique to the detection of defects related to the three‐dimensional (3D) profile of IC wire bonds. In our single‐camera–based setup, stereo views are obtained by rotating the IC chip under the CCD camera with a telecentric lens. The edges of the wires are detected using Petrou's line filter and the facet model applied to obtain subpixel edge localization. After linking edges to form meaningful curves, stereo matching is conducted between the two curve lists of a stereo pair. The height profiles of the wire bonds are obtained using the disparity equation derived from the imaging geometry. © 2001 John Wiley & Sons, Inc. Int J Imaging Syst Technol 11, 254–262, 2000
Pralidoxime and l ‐lactate effects in vitro on the inhibition of acetylcholinesterase by paraoxon: pralidoxime does not confer superior protection
Authors: Petroianu Georg , Roth Christina , Beha Ulrike , Fisher Joseph , Bergler Wolfgang , Rüfer Roderich 
Published: September 2002

AbstractIntoxication with the organophosphorus compound paraoxon (POX), an inhibitor of serine hydrolases, is frequent. Although oximes are the only enzyme reactivators presently available, clinical experience with their use was rather disappointing. Recent work has shown that under certain conditions l‐lactate is also able to reduce in vitro the POX inhibition of butyrylcholine‐ and acetylcholineesterase (BChE and AChE). To assess the practical relevance, if any, of these findings, the protective effects of pralidoxime (PRX) and those of lactate had to be compared in the same in vitro model.Effects of PRX on the inhibition of AChE by POX were assessed in vitro in plasma of 12 (six male and six female) healthy human volunteers. The determinations were repeated using different oxime and different POX concentrations.The AChE activity determinations were performed using the following sampler: sample BL—baseline (or untreated plasma); sample a—after addition of POX to plasma (pl + POX); sample b—after POX and plasma were incubated and then oxime was added (pl + POX/PRX); sample c—after addition of oxime to plasma (pl + PRX); sample d—after oxime and plasma were incubated and then POX was added (pl + PRX/POX); sample e—after oxime and POX were incubated and then added to plasma (PRX + POX/pl).Results were corrected for spurious enzyme ‘pseudo‐activity’ due to interaction between PRX and substrate (acetylthiocholine) in the absence of enzyme. In the micro‐ and millimolar ranges, PRX is able to protect in vitro AChE from inhibition by POX when added to human plasma prior to POX or when incubated with POX prior to addition to plasma. Adding PRX to plasma after POX has no protective effect. The PRX results were compared statistically with historical lactate data (obtained under identical conditions) using the Wilcoxon matched pairs test, with significance assumed for p = 0.01. No difference between PRX and lactate's protective effect on the AChE inhibition by POX was found in the in vitro model used. We therefore conclude that in vivo testing of lactate as a POX protective agent is warranted. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of in vitro wear of machined and molded UHMWPE tibial inserts on TKR kinematics
Authors: Benson Lisa C. , DesJardins John D. , LaBerge Martine 
Published: September 2002

AbstractThe effect of manufacturing process on the wear and mechanical performance of a total knee replacement (TKR) design was investigated with the use of a force‐controlled knee joint simulator. Ultra‐high molecular weight polyethylene (UHMWPE) tibial inserts processed by direct compression molding from 1900H resin were compared to UHMWPE tibial inserts machined from a compression‐molded sheet of GUR 1050. Both sets of components had the same posterior‐cruciate‐retaining geometry, and were identically aligned with cobalt–chromium–molybdenum alloy femoral components. Wear tests were conducted at a frequency of 1 Hz for 4 million cycles with the use of a standard walking cycle pattern. Implant kinematics, including anterior–posterior (AP) displacement and internal–external (IE) rotation in response to applied loads were monitored. Gravimetric wear, surface roughness, and surface morphology were used to characterize the wear process of the UHMWPE inserts. Results showed that the molded UHMWPE inserts exhibited less gravimetric wear over time than the machined inserts of the same design. Both the machined and molded components exhibited scratching, pitting, and burnishing over their wear areas. The AP displacement distance per cycle of the molded tibial inserts decreased over the course of testing, resulting in a shorter total testing displacement for this group compared to machined tibial inserts. Although AP displacement distance per cycle for machined tibial inserts did not change significantly over the course of testing, their position relative to the femoral components shifted posteriorly over time, resulting in an elongated wear track. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 496–504, 2001
The pH dependence of monofilament sutures on hydrolytic degradation
Authors: Tomihata Kenji , Suzuki Masakazu , Ikada Yoshito 
Published: September 2002

AbstractHydrolytic degradation of two nonabsorbable sutures, four absorbable sutures, and a new type of absorbable suture was studied in buffered media of various pHs at 37 °C. The pH levels fixed in this study were 1.0, 7.4, 8.5, and 10.5. Physical measurements were made on the retention of tensile strength and melting temperature of the sutures after hydrolysis for 12 weeks. Sutures containing glycolic acid as a comonomer exhibited enhanced degradation in alkaline media, similar to polyglycolide multifilament sutures. Poly‐p‐dioxanone (PDS II®) suture lost strength to a significant extent at pH 1.0, suggesting that care should be taken when this suture is used for closing tissues in contact with acidic media, such as the stomach. In marked contrast, the degradation of lactide‐ϵ‐caprolactone copolymer [P(LA/CL)] suture was not sensitive to the pH of media. The surface morphology of hydrolyzed sutures varied, depending on the pH of media. Particularly, moon‐crater‐shaped impressions were observed on glycolide‐ϵ‐caprolactone copolymer (MONOCRYL®) and glycolide‐trimethylene carbonate‐dioxanone copolymer (BIOSYN®) sutures. Among the nonabsorbable sutures, nylon (ETHILON®) exhibited the fastest loss of strength in acidic buffer solution, and polypropylene (PROLENE®) suture retained most of its initial strength at all pHs studied. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 511–518, 2001
Electrochemical conversion of phenolic wastewater on carbon electrodes in the presence of NaCl
Authors: Körbahtı Bahadir K , Salih Bekir , Tanyolaç Abdurrahman 
Published: September 2002

AbstractThe electrochemical conversion of highly concentrated synthetic phenolic wastewater was studied on carbon electrodes in a batch electrochemical reactor. The effects of reaction temperature, electrolyte concentration, current density and initial phenol concentration on phenol conversion were elucidated. The wastewater was synthetically prepared and used in reactions carried out generally at 25 °C with an initial phenol concentration of 3500 mg dm−3. Although current density increased, phenol conversion% and initial phenol conversion rate did not increase correspondingly above 35 °C and an electrolyte concentration of 90 g dm−3. As the voltage values applied were increased, the increasing current density resulted in fast phenol conversion. Kinetic investigations denoted that overall phenol destruction kinetics was of zero order with an activation energy of 10.9 kJ mol−1. Under appropriate conditions, phenol was completely converted within 15 min for an initial phenol concentration of 98 mg dm−3 while 8 h was required to gain 95% conversion using 4698 mg dm−3. Solid polymeric materials were produced at initial phenol concentrations above 500 mg dm−3 using the appropriate current density. In the reaction medium, only mono‐, di‐ and tri‐substituted chlorophenols were formed and 100% of all species were either oxidised or contributed to the formation of a polymeric structure. Almost all of the phenol loaded to the reactor was converted into non‐passivating polymeric products, denoting a safe and easy method for the separation of phenol.© 2001 Society of Chemical Industry
Modelling and simulation of a hybrid process (pervaporation–distillation) for the separation of azeotropic mixtures of alcohol–ether
Authors: González Beatriz , Ortiz Inmaculada 
Published: September 2002

AbstractThis work reports the modelling and simulation of a hybrid process, based on the combination of distillation and pervaporation, for the separation of azeotropic mixtures of alcohol–ether. After having selected the separation of methanol‐2‐metoxi‐2,2‐dimethyl ethane (ETHER) as a motivating example the mathematical modelling of the distillation column was achieved and used together with a mass transfer model previously reported for the pervaporation operation in order to simulate the behaviour of the hybrid process for different compositions of the feed stream (case 1: 3.2 wt% methanol, 55.4 wt% C4, 41.4 wt% ETHER, and case 2: 5.2 wt% methanol, 42 wt% C4, 52.8 wt% ETHER). Simulation tasks were carried out with the process modelling system gPROMS and the results of alternative process configurations that result from the relative location of the separation technologies have been compared on the basis of the required membrane area. Finally, the design of the pervaporation unit including the overall processing costs is reported.Copyright © 2001 Society of Chemical Industry
Contrast‐enhanced color Doppler sonography of uveal melanomas
Authors: Lemke Arne‐Joern , Hosten Norbert , Richter Miriam , Bechrakis Nikolaos Emanuel , Foerster Paul , Puls Ralf , Gutberlet Matthias , Felix Roland 
Published: September 2002

AbstractPurposeThe purpose of our study was to evaluate the use of the galactose microbubble‐based contrast agent Levovist in color Doppler sonography of uveal melanomas. We also evaluated the use of the resistance index and pulsatility index in differentiating tumor‐associated vessels from normal vessels in patients with uveal melanomas.MethodsIn this prospective study, 40 patients with uveal melanoma were examined with color Doppler sonography before and after the administration of the contrast agent Levovist. The Doppler signals were recorded from both the tumor and the orbit and were evaluated quantitatively and qualitatively.ResultsTumor‐associated vessels were detected without contrast enhancement in 36 of 40 patients and with contrast enhancement in 38 of 40 patients. The spectral characteristics of the Doppler signals did not change after the injection of Levovist. There were no differences—qualitative or quantitative—in Doppler signals between normal and tumor‐associated vessels.ConclusionsThe injection of Levovist slightly improved the detection of small vessels in uveal melanomas and the orbit but did not help to differentiate between normal vessels and tumoral vessels. The differentiation of a solid tumor from subretinal hemorrhage or effusion was improved. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:205–211, 2001.
Regulation of metamorphosis in ascidians involves NO&sol;cGMP signaling and HSP90
Authors: Bishop Cory D. , Bates William R. , Brandhorst Bruce P. 
Published: September 2002

AbstractTreatment of larvae of the ascidians Boltenia villosa &lpar;Family: Pyuridae&rpar; and Cnemidocarpa finmarkiensis &lpar;Family: Styelidae&rpar; with drugs that inhibit the function of the molecular chaperone HSP90 increased the frequency of tail resorption, the primary morphogenetic event of metamorphosis. If treatment was initiated at hatching, metamorphic events subsequent to tail resorption failed to occur, indicating an ongoing role for HSP90 during morphogenesis. Removal of tails from heads of mature, but not newly hatched larvae, induced metamorphosis of the head. Decapitation experiments indicate that the capacity of tails to shorten in response to inhibition of HSP90 function requires communication with heads. To identify candidate proteins with which HSP90 may interact to regulate metamorphosis, we noted that in mammalian cells, nitric oxide synthase &lpar;NOS&rpar; interacts with HSP90 and its activity is sensitive to drugs that inhibit HSP90 function. In addition, nitric oxide &lpar;NO&rpar; signaling in the marine snail Ilyanassa obsoleta is an important regulator of metamorphosis. Inhibition of NOS activity in these ascidian larvae with L&hyphen;NAME increased the frequency of metamorphosis, consistent with a putative interaction of NOS and HSP90. NOS is present in tail muscle cells, implicating them as targets for the drug treatments, consistent with the decapitation experiments. Inhibition of soluble guanylyl cyclase, the most common effector of NO signaling, also increased the frequency of metamorphosis. In contrast to treatment with anti&hyphen;HSP90 drugs, metamorphosis induced with L&hyphen;NAME or ODQ was complete. The results presented suggest that an HSP90&hyphen;dependent, NO&hyphen;based regulatory mechanism localized in tails represses ascidian metamorphosis. We discuss these results in relation to the induction of ascidian metamorphosis by several unrelated agents. J. Exp. Zool. 289:374&ndash;384, 2001. &copy; 2001 Wiley&hyphen;Liss, Inc.
Immunocytochemical and electrophoretic distribution of cytokeratins in the resting stage epidermis of the lizard Podarcis sicula
Authors: Alibardi Lorenzo , Maurizii Mariagabriella , Taddei Carlo 
Published: September 2002

AbstractThe distribution of three anti‐cytokeratin (α‐keratin) antibodies (AE1, AE2, AE3) in the epidermis of a lizard has been studied by immunocytochemistry at light and electron microscope and by immunoblot analysis. This study shows the expression of different keratins in the resting stage epidermis of the lizard Podarcis sicula. In this stage the epidermis has an external β‐layer, an underlying α‐layer, some layers of living suprabasal cells and a basal stratum germinativum. The AE1 antibody is localized in the basal and suprabasal cells only in the outer scale surface, but is absent from the inner surface, the hinge region and from the keratinized β‐ and α‐layers. The AE2 antibody is mainly localized at the level of the hinge region and of the α‐layer and gives a lower reaction in the β‐layer. The AE3 antibody is mainly localized in basal and suprabasal cells, lower in the α‐layer, and absent from the β‐layer. The electron microscope shows that all the three antibodies immunolabel cytoplasmic fibrillar structures in the deep α‐layers and that AE2 and AE3 antibodies label small electron‐dense areas in the external dense β‐layer within the electron‐lucid matrix. Immunoblot analysis of the keratins extracted and separated by gel electrophoresis demonstrates the presence of a band of high molecular weight (67–68 kDa) positive to all three antibodies. In addition AE1 antibody recognizes a 44–45 kDa band and a 57–58 kDa band, AE2 recognizes a 60–61 kDa band, and AE3 recognizes a 47 kDa and a 56–57 kDa band. The localization of the keratins identified by immunoblot analysis in the epithelial layers is discussed taking in account the immunolabeling at light and electron microscope. The present study suggests that also in the normal epidermis of this reptiles, in both the α‐ and the β‐layer, the molecular masses of keratins increase from the basal to the keratinized layers, a phenomenon which is generalized to adult and embryonic amniotes epidermis. J. Exp. Zool. 289:409–418, 2001. © 2001 Wiley‐Liss, Inc.
Independent perfect domination sets in Cayley graphs
Authors: Lee Jaeun 
Published: September 2002

AbstractIn this paper, we show that a Cayley graph for an abelian group has an independent perfect domination set if and only if it is a covering graph of a complete graph. As an application, we show that the hypercube Qn has an independent perfect domination set if and only if Qn is a regular covering of the complete graph Kn+1 if and only if n = 2m − 1 for some natural number m. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 213–219, 2001
Another two graphs with no planar covers
Authors: Hlinĕný Petr 
Published: September 2002

AbstractA graph H is a cover of a graph G if there exists a mapping φ from V(H) onto V(G) such that φ maps the neighbors of every vertex υ in H bijectively to the neighbors of φ(υ) in G. Negami conjectured in 1986 that a connected graph has a finite planar cover if and only if it embeds in the projective plane. It follows from the results of Archdeacon, Fellows, Negami, and the author that the conjecture holds as long as K1,2,2,2 has no finite planar cover. However, this is still an open question, and K1,2,2,2 is not the only minor‐minimal graph in doubt. Let 𝒞4 (ℰ2) denote the graph obtained from K1,2,2,2 by replacing two vertex‐disjoint triangles (four edge‐disjoint triangles) not incident with the vertex of degree 6 with cubic vertices. We prove that the graphs 𝒞4 and ℰ2 have no planar covers. This fact is used in [P. Hlinĕný, R. Thomas, On possible counterexamples to Negami's planar cover conjecture, 1999 (submitted)] to show that there are, up to obvious constructions, at most 16 possible counterexamples to Negami's conjecture. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 227–242, 2001
Socialist psychotherapy and its dissidents
Authors: Leuenberger Christine 
Published: September 2002

AbstractThis article focuses on the history of psychotherapeutic theory and practice in socialist East Germany before the fall of the Berlin Wall in 1989. The “official” pre‐1989 socialist history of East German psychology is juxtaposed to psychotherapists' post‐1989 oral history of the development of Socialist psychological theory and practice. These reconstructive histories draw on embryonic therapeutic practices that diverged from the dominant socialist paradigm. Their existence exemplifies how a state‐driven high modernist scheme for remaking society can fail as it does not account for the complex relationship between a state's abstract knowledge and local practices. Moreover, the emphasis therapists put on the prevalence of these alternative practices also reveals how the present post‐socialist context becomes an interpretative resource for reconstructing their past. By emphasizing these practices they try to bridge the gap between their past and current practices so as to minimize the transformation that has taken place. © 2001 John Wiley & Sons, Inc.
Coping strategies in developed and developing societies: the workings of the informal economy
Authors: Leonard Madeleine 
Published: September 2002

AbstractThe purpose of this paper is to examine the persistence and significance of informal economic activity in both the developed and developing world. Drawing on empirical work carried out in Belfast, the paper suggests that many similarities exist between the informal economic activities of people on low incomes in Belfast and the poor in developing countries. The paper illustrates these connections through an examination of three aspects of the informal economy: reciprocity between households, informal self‐employment and informal paid employment. By examining the variety of ways in which people at the lower end of the economic scale attempt to secure their economic livelihoods in the absence of formal employment opportunities, the paper demonstrates the global nature of the informal economy. Copyright © 2000 John Wiley & Sons, Ltd.
Are user charges efficiency‐ and equity‐enhancing? A critical review of economic literature with particular reference to experience from developing countries
Authors: Sepehri Ardeshir , Chernomas Robert 
Published: September 2002

AbstractUser charges have come to play a significant role in the financing and delivery of publicly provided health services in many developing countries. As a response to health care financing crises, user charges are often promoted as a way of rationalizing the use of care, raising revenue, and improving the coverage and quality of services. The primary purpose of this paper is to provide a critical review of the main arguments for the efficiency‐ and equity‐enhancing potential of user charges.The extent and scope of welfare gains from user charges are found to be very limited in practice. Using a less restrictive theoretical choice model and estimation technique, the most recent demand studies' findings indicate that household's utilization of health services are more responsive to changes in price and income than was initially reported by the early demand studies. Response to price changes are also found to be greater among the poor than the rich. These findings, combined with modest retained fee revenues and the failure of exemption mechanisms to protect the poor tend to cast doubt on the net benefits of user charges policy, particularly in the area of equity. Copyright © 2001 John Wiley & Sons, Ltd.