bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlled drainage effects on water quality under semi‐arid conditions in the western delta of Egypt
Authors: Wahba M.A.S. , El‐Ganainy M. , Abdel‐Dayem M.S. , Gobran Atef. , Kandil H. 
Published: August 2002

AbstractField experiments were conducted for two years in the Western Delta of Egypt to investigate the effects of controlled drainage on the quality of subsurface drainage outflows. Two water table management methods were applied in the 2.54 ha experimental field: free conventional subsurface drainage and controlled drainage. Controlled drainage was applied at 60 cm depth during both seasons. Drain discharge volumes and nitrate‐N and orthophosphate‐phosphorus concentrations were monitored during the growing seasons. The controlled drainage (CD) treatment significantly reduced the total drainage outflow by 68% during the summer season and by 28% during the winter of 1999–2000 at 99% confidence level, compared to free conventional drainage (FD) treatment. The CD also reduced the total nitrate‐N in drainage water by 73%, and 32% during the summer and the winter seasons respectively, compared to the FD treatment.The CD treatment reduced the total orthophosphate‐phosphorus losses by 77% during summer of 1999 and by 30% during winter of 1999–2000 compared to the FD treatment; however, in general the total mass loss was low in both treatments. The results of the experiment showed the potential environmental and economic benefits with the application of controlled drainage in semi‐arid regions. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluating business credit risk by means of approach‐integrating decision rules and case‐based learning
Authors: Stefanowski Jerzy , Wilk Szymon 
Published: August 2002

AbstractThis research utilizes a new approach which uses a hybrid learning system that combines two representations of knowledge: the first in a form of decision rules referring to general knowledge, and the other of single cases corresponding to exceptions or untypical situations. The Explore algorithm was chosen as a tool for inducing general rules. It generates all simple and sufficiently strong general rules from a given data set. Examples discovered by these rules are then used to identify exceptions and untypical cases. The paper discusses problems connected with tuning parameters of this approach and introduces a new procedure for this task. This methodology is applied to solve the problem of evaluating the risk of business credit applications in a Polish commercial bank. Using information about business credit applications, as described by 35 economic parameters and using five groups of banking risk, a knowledge base consisting of 70 decision rules and 15 specific cases was induced. Testing this model in the standard ‘leaving‐one‐out’ way we achieved the best classification accuracy of 81%. A comparative study showed that results obtained by other machine‐learning algorithms resulted in significantly worse classification accuracy. Copyright © 2001 John Wiley & Sons, Ltd.
Quasi‐fixed inputs and long‐run equilibrium in production: a cointegration analysis
Authors: Kim H. Youn , Lee Junsoo 
Published: August 2002

AbstractThis paper proposes a cointegration approach to testing the validity long‐run equilibrium in production, where capital and labour are taken as quasi‐fixed inputs. Previous studies consider only capital as the quasi‐fixed input and do not take account of the time series properties of the variables, assuming implicitly that they are stationary. The canonical cointegrating regressions (CCR) procedure is employed to test for cointegration in both the single‐equation and the seemingly unrelated regressions framework, and long‐run equilibrium conditions are tested. The evidence from US manufacturing reveals that capital and labour are not fully adjusted to their long‐run optimal values, casting doubt on the long‐run equilibrium hypothesis. Copyright © 2001 John Wiley & Sons, Ltd.
A flexible parametric GARCH model with an application to exchange rates
Authors: Wang Kai‐Li , Fawson Christopher , Barrett Christopher B. , McDonald James B. 
Published: August 2002

AbstractMany asset prices, including exchange rates, exhibit periods of stability punctuated by infrequent, substantial, often one‐sided adjustments. Statistically, this generates empirical distributions of exchange rate changes that exhibit high peaks, long tails, and skewness. This paper introduces a GARCH model, with a flexible parametric error distribution based on the exponential generalized beta (EGB) family of distributions. Applied to daily US dollar exchange rate data for six major currencies, evidence based on a comparison of actual and predicted higher‐order moments and goodness‐of‐fit tests favours the GARCH‐EGB2 model over more conventional GARCH‐t and EGARCH‐t model alternatives, particularly for exchange rate data characterized by skewness. Copyright © 2001 John Wiley & Sons, Ltd.
Role of heat shock protein 60 (HSP60) on paraquat intoxication
Authors: Kaetsu Akihiko , Fukushima Tetsuhito , Inoue Seigou , Lim Heejin , Moriyama Masaki 
Published: August 2002

AbstractThe possibility of establishing a new method of treatment against pulmonary fibrosis caused by acute paraquat intoxication, which takes into consideration the role of heat shock protein 60 (HSP60), was investigated in paraquat‐exposed rat lung mitochondria. In polyacrylamide electrophoresis, mitochondrial protein bands appeared, especially in the range of molecular weight 60 kDa and higher, whereas protein bands disappeared in the 20–40 kDa range on the 4th day after paraquat exposure. The protein profile was normalized on the 7th day and no remarkable changes were seen thereafter up to the 56th day. The changes seen during the observation period were thought to reflect the course of paraquat‐induced dysfunction and subsequent repair. The malondialdehyde concentration in mitochondria decreased until the 7th day but subsequently increased and recovered to normal levels by the 56th day. The relative density of HSP60 increased until the 7th day but subsequently decreased and recovered to normal levels by the 56th day. These two parameters therefore showed symmetrical changes. The change in the malondialdehyde concentration was thought to reflect the course of activation of the antioxidation function in mitochondria and the progression of repair. The change in the relative density of HSP60 was thought to have increased to repair the proteins affected by the paraquat radical and to have normalized with the progression of healing. These results suggest that HSP60 may play an important role in preventing the progression of pulmonary fibrosis induced by paraquat. Copyright © 2001 John Wiley & Sons, Ltd.
Fabrication of porous hydroxyapatite bodies by a new direct consolidation method: starch consolidation
Authors: Rodríguez‐Lorenzo L. M. , Vallet‐Regí M. , Ferreira J. M. F. 
Published: August 2002

AbstractA new direct consolidation method known as “starch consolidation” was developed especially for the fabrication of porous ceramics, as adopted to prepare hydroxyapatite (OHAp) bodies with different pore sizes and pore volume fractions. The method is based on the swelling ability of starch when it is heated to 80°C in the presence of water. An OHAp powder prepared by a precipitation method and heat treated at 900°C to obtain an appropriate specific surface area for colloidal processing was used in the present work. Wet ball milling was required to deagglomerate the powder and improve its processing ability. Different starch volume fractions and starch particle sizes were added to the OHAp slurries, which were then heat treated to promote consolidation by starch gelification. A linear relationship between the planned and measured porosity values was observed. SEM pictures reveal the presence of interconnected pores with shape and sizes corresponding to starch granules used. Flexural strength varied from about 2 to 15 MPa, for pore volume fractions of ∼70 and 45%, respectively. A degradation study in an acellular synthetic body fluid (SBF) has shown that the prepared bodies keep their integrity under physiological conditions during the studied time. The method offers possibilities of manufacturing materials that can be used as scaffolds engineering and/or systems for controlled delivery of drugs. © 2002 John Wiley & Sons, Inc. J Biomed Mater Res 60: 232–240, 2002; DOI 10.1002/jbm.10036
Force spectroscopy study of the adhesion of plasma proteins to the surface of a dialysis membrane: Role of the nanoscale surface hydrophobicity and topography
Authors: Conti Matteo , Donati Gabriele , Cianciolo Giuseppe , Stefoni Sergio , Samorì Bruno 
Published: August 2002

AbstractA mechanochemical study of the process of adhesion of plasma proteins to the surface of dialysis membranes was carried out with a scanning force microscope (SFM) in the force spectroscopy mode. Three representative blood plasma proteins (fibronectin, fibrinogen, and albumin) covalently were grafted to a SFM probe, and the adhesion forces of these proteins to cellulosic and synthetic dialysis membranes were measured. The experiment was tailored to apply a controlled load on the protein molecules adsorbed onto the surface in order to simulate the squeezing forces exerted on them during blood filtration. The de‐adhesion forces, measured using this new approach for studying the interaction between a protein and dialysis membranes, suggest that the membrane's topography, at a nanometer scale, plays a critical role in the adhesion process. This result was strongly supported by parallel experiments performed on a flattened glass surface with the same dominant hydrophilic character as dialysis membranes. In contrast, a hydrophobic polystyrene surface led to de‐adhesion forces at least one order of magnitude greater, overwhelming any possible shape recognition process between the protein molecules and the surface. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 370–379, 2002
Lactic acid based PEU/HA and PEU/BCP composites: Dynamic mechanical characterization of hydrolysis
Authors: Rich Jaana , Tuominen Jukka , Kylmä Janne , Seppälä Jukka , Nazhat Showan N. , Tanner K. Elizabeth 
Published: August 2002

AbstractLactic acid based poly(ester‐urethane) (PEU‐BDI) and its composites with 20 and 40 vol.% bioceramic filler were characterized prior to their use as biocompatible and bioabsorbable artificial bone materials. Morphological, dynamic mechanical properties, and degradation of these either hydroxyapatite or biphasic calcium phosphate containing composites were determined. Addition of particulate bioactive filler increased the composite stiffness and the glass transition temperature, indicating strong interactions between the filler and matrix. Materials were sterilized by γ‐irradiation, which reduced the average molecular weights by 30–40%. However, dynamic mechanical properties were not significantly affected by irradiation. Specimens were immersed in 0.85 w/v saline at 37 °C for 5 weeks, and changes in molecular weights, mass, water absorption, and dynamic mechanical properties were recorded. All the composite materials showed promising dynamic mechanical performance over the 5 weeks of hydrolysis. Average molecular weights of PEU‐BDI and its composites did not change substantially during the test period. PEU‐BDI retained its modulus values relatively well, and although the moduli of the composite materials were much higher, especially at high filler content, they exhibited faster loss of mechanical integrity. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 346–353, 2002
Measuring the elastic properties of fine wire
Authors: Fallen C.T. , Costello J. , Crawford G. , Schmidt J.A. 
Published: August 2002

AbstractThe elastic moduli of fine wires made from MP35N and 304SS used in implantable biomedical devices are assumed to be the same as those published in the literature. However, the cold working required to manufacture the wire significantly alters the elastic moduli of the material. We describe three experiments performed on fine wire made from MP35N and 304SS. The experimentally determined Young's and shear modulus of both wire types were significantly less than the moduli reported in the literature. Young's modulus differed by as much as 26%, and the shear modulus differed by as much as 14% from reported values.
Biocompatible microcapsules with enhanced mechanical strength
Authors: Chang Shwu Jen , Lee Chen Hsen , Hsu Chun Yuan , Wang Yng Jiin 
Published: August 2002

AbstractA block copolymer, (short‐chain alginate)‐co‐MPEG, was synthesized and used for coating the capsular membranes of the photosensitive microcapsules. The resulted microcapsules exhibited an excellent mechanical strength. The permeability test results revealed that the capsular membrane was freely permeable to cytochrome C and myoglobin, less permeable to serum albumin, and almost impermeable to IgG. In the cell attachment test, the results showed that the surface formed by (short‐chain alginate)‐co‐MPEG copolymer could effectively reduce cell adhesion as compared to poly(L‐lysine) and alginate. The microcapsules were evaluated by intraperitoneal implantation experiment of mice. The results demonstrated that microcapsules coated with (short‐chain alginate)‐co‐MPEG were more biocompatible than the conventional alginate/PLL/alginate microcapsules. © 2001 Wiley Periodicals, Inc. J Biomed Mater Res 59: 118–126, 2002
Lack of requirement of STAT1 for activation of nuclear factor‐κB, c‐Jun NH2‐terminal protein kinase, and apoptosis by tumor necrosis factor‐α
Authors: Mukhopadhyay Asok , Shishodia Shishir , Fu Xin‐Yuan , Aggarwal Bharat B. 
Published: August 2002

AbstractTumor necrosis factor (TNF) is one of the most potent activators of nuclear transcription factor NF‐κB, c‐Jun N‐terminal protein kinase (JNK), and apoptosis in a wide variety of cells. The biological effects of TNF are mediated through sequential interactions of various cytoplasmic proteins with intracellular domains of TNF receptors. Whether signal transducer and activator of transcription‐1 (STAT1), which mediates interferon (IFN) signaling, also plays any role in the TNF‐mediated activation of NF‐κB, JNK, and apoptosis has not been established. Here, we report our investigation of the role of STAT1 in TNF signaling using STAT1‐deficient U3A and STAT1‐stably transfected U3A‐PSG91 cells. IFNα inhibited the proliferation of STAT1‐expressing U3A‐PSG91 cells but had no effect on STAT1‐negative U3A cells. TNF alone, even up to 10 nM, had no effect on the proliferation of either U3A‐PSG91 or U3A cells. Irrespective of STAT1 status, TNF induced cytotoxic effects in the presence of cycloheximide (CHX) in both cell types. Additionally, TNF‐induced caspase‐3 and caspase‐8 activation and TNF‐induced PARP cleavage were unaffected by the presence or absence of STAT1. TNF activated NF‐κB, consisting of p50 and p65, in both U3A and U3A‐pSG91 cells in a dose‐ and time‐dependent manner, but the degree and rate of activation were slightly lower in U3A cells, as were IκBα degradation and NF‐κB‐dependent reporter gene expression. STAT1 was, however, required for IFNα‐mediated downregulation of TNF‐induced NF‐κB activation. TNF activated JNK in both cell types, but dose and time of exposure required for optimum activation differed slightly. Thus, overall our results indicate that STAT1 plays a minimal role in TNF‐mediated cellular responses. J. Cell. Biochem. 84: 803–815, 2002. © 2002 Wiley‐Liss, Inc.
Chromatin and histones from Giardia lamblia: A new puzzle in primitive eukaryotes
Authors: Triana Omar , Galanti Norbel , Olea Nancy , Hellman Ulf , Wernstedt Christer , Lujan Hugo , Medina Carlos , Toro G. Cecilia 
Published: August 2002

AbstractThe three deepest eukaryote lineages in small subunit ribosomal RNA phylogenies are the amitochondriate Microsporidia, Metamonada, and Parabasalia. They are followed by either the Euglenozoa (e.g., Euglena and Trypanosoma) or the Percolozoa as the first mitochondria‐containing eukaryotes. Considering the great divergence of histone proteins in protozoa we have extended our studies of histones from Trypanosomes (Trypanosoma cruzi, Crithidia fasciculata and Leishmania mexicana) to the Metamonada Giardia lamblia, since Giardia is thought to be one of the most primitive eukaryotes. In the present work, the structure of G. lamblia chromatin and the histone content of the soluble chromatin were investigated and compared with that of higher eukaryotes, represented by calf thymus. The chromatin is present as nucleosome filaments which resemble the calf thymus array in that they show a more regular arrangement than those described for Trypanosoma. SDS‐polyacrylamide gel electrophoresis and protein characterization revealed that the four core histones described in Giardia are in the same range of divergence with the histones from other lower eukaryotes. In addition, G. lamblia presented an H1 histone with electrophoretic mobility resembling the H1 of higher eukaryotes, in spite of the fact that H1 has a different molecular mass in calf thymus. Giardia also presents a basic protein which was identified as an HU‐like DNA‐binding protein usually present in eubacteria, indicating a chimaeric composition for the DNA‐binding protein set in this species. Finally, the phylogenetic analysis of selected core histone protein sequences place Giardia divergence before Trypanosoma, despite the fact that Trypanosoma branch shows an acceleration in the evolutionary rate pointing to an unusual evolutionary behavior in this lineage. J. Cell. Biochem. 82: 573–582, 2001. © 2001 Wiley‐Liss, Inc.
Molecular and cellular mechanisms of adipose secretion: Comparison of leptin and angiotensinogen
Authors: Turban S. , Hainault I. , André J. , Ferré P. , Quignard‐Boulangé A. , Guerre‐Millo M. 
Published: August 2002

AbstractBesides their function of lipid storage, the adipose cells secrete a number of proteins of physiopathological importance. To get further insights into this function, which remains poorly characterized, we sought to compare the mechanisms and regulation of secretion of two individual proteins in the same cells. Leptin and angiotensinogen were chosen and assessed by radioimmunoassay and quantitative immunoblotting, respectively, in primary culture of epididymal adipose cells from young obese Zucker rats. Leptin was secreted at a steady rate of 4 ng/106 cells/h over 2–6 h. Despite secretion, leptin cellular content remained stable at 3 ng/106 cells. In contrast, the rate of angiotensinogen secretion decreased regularly from 45 arbitrary units/106 cells/h at 2 h, to half this value at 6 h, although cell content remained constant at 100 arbitrary units/106 cells. Inhibition of protein synthesis by cycloheximide depleted the cells from leptin, but not from angiotensinogen for up to 6 h. Insulin increased leptin secretion (+75%) and cell content (+70 %), without affecting angiotensinogen. Secretion of both proteins was inhibited by Golgi‐disturbing agents, brefeldin A and monensin. The presence of brefeldin A led to a specific rise in leptin cell content, an effect inhibited by cycloheximide and enhanced by insulin (+80%). These data show that leptin and angiotensinogen are both secreted through Golgi‐dependent pathways and that their respective intracellular pool exhibit distinct turn‐over rate and insulin sensitivity. These characteristics might account for the differential response of these adipose proteins to variations in the systemic environment. J. Cell. Biochem. 82: 666–673, 2001. © 2001 Wiley‐Liss, Inc.
Stimulatory effect of lactate on testosterone production by rat Leydig cells
Authors: Lin Ho , Wang Shyi‐Wu , Wang Ray‐Yau , Wang Paulus S. 
Published: August 2002

AbstractPreviously we found that the increased plasma testosterone levels in male rats during exercise partially resulted from a direct and luteinizing hormone (LH)‐independent stimulatory effect of lactate on the secretion of testosterone. In the present study, the acute and direct effects of lactate on testosterone production by rat Leydig cells were investigated. Leydig cells from rats were purified by Percoll density gradient centrifugation subsequent to enzymatic isolation of testicular interstitial cells. Purified rat Leydig cells (1 × 105 cells/ml) were in vitro incubated with human chorionic gonadotropin (hCG, 0.05 IU/ml), forskolin (an adenylyl cyclase activator, 10−5 M), or 8‐bromo‐adenosine‐3′:5′‐cyclic monophosphate (8‐Br‐cAMP, 10−4 M), SQ22536 (an adenylyl cyclase inhibitor, 10−6–10−5 M), steroidogenic precursors (25‐hydroxy‐cholesterol, pregnenolone, progesterone, and androstenedione, 10−5 M each), nifedipine (a L‐type Ca2+ channel blocker, 10−5–10−4 M), or nimodipine (a potent L‐type Ca2+ channel antagonist, 10−5–10−4 M) in the presence or absence of lactate at 34°C for 1 h. The concentration of medium testosterone was measured by radioimmunoassay. Administration of lactate at 5–20 mM dose‐dependently increased the basal testosterone production by 63–187% but did not alter forskolin‐ and 8‐Br‐cAMP‐stimulated testosterone release in rat Leydig cells. Lactate at 10 mM enhanced the stimulation of testosterone production induced by 25‐hydroxy‐cholesterol in rat Leydig cells but not other steroidogenic precursors. Lactate (10 mM) affected neither 30‐ nor 60‐min expressions of cytochrome P450 side chain cleavage enzyme (P450scc) and steroidogenic acute regulatory (StAR) protein. The lactate‐stimulated testosterone production was decreased by administration of nifedipine or nimodipine. These results suggested that the physiological level of lactate stimulated testosterone production in rat Leydig cells through a mechanism involving the increased activities of adenylyl cyclase, cytochrome P450scc, and L‐type Ca2+ channel. J. Cell. Biochem. 83: 147–154, 2001. © 2001 Wiley‐Liss, Inc.
α1‐adrenergic stimulation mediates Ca2+‐dependent inositol phosphate formation through the α1B‐like adrenoceptor subtype in adult rat cardiac myocytes
Authors: Seraskeris Stelios , Lazou Antigone 
Published: August 2002

AbstractWe studied the effects of increased Ca2+ influx on α1‐adrenoceptor‐stimulated InsP formation in adult rat cardiac myocytes. We further examined if such effects could be mediated through a specific α1‐adrenoceptor subtype. [3H]InsP responses to adrenaline were dependent on extracellular Ca2+ concentration, from 0.1 μM to 2 mM, and were completely blocked by Ca2+ removal. However, in cardiac myocytes preloaded with BAPTA, a highly selective calcium chelating agent, Ca2+ concentrations higher than 1 μM had no effect on adrenaline‐stimulated [3H]InsP formation. Taken together these results suggest that [3H]InsP formation induced by α1‐adrenergic stimulation is in part mediated by increased Ca2+ influx. Consistent with this, ionomycin, a calcium ionophore, stimulated [3H]InsP formation. This response was additive with the response to adrenaline stimulation implying that different signaling mechanisms may be involved. In cardiac myocytes treated with the α1B‐adrenoceptor alkylating agent, CEC, [3H]InsP formation remained unaffected by increased Ca2+ concentrations, a pattern similar to that observed when intracellular Ca2+ was chelated with BAPTA. In contrast, addition of the α1A‐subtype antagonist, 5′‐methyl urapidil, did not affect the Ca2+ dependence of [3H]InsP formation. Neither nifedipine, a voltage‐dependent Ca2+ channel blocker nor the inorganic Ca2+ channel blockers, Ni2+ and Co2+, had any effect on adrenaline stimulated [3H]InsP, at concentrations that inhibit Ca2+ channels. The results suggest that in adult rat cardiac myocytes, in addition to G protein‐mediated response, α1‐adrenergic‐stimulated [3H]InsP formation is activated by increased Ca2+ influx mediated by the α1B‐subtype. J. Cell. Biochem. 84: 201–210, 2002. © 2001 Wiley‐Liss, Inc.