bluuebunny/crossref_metadata_2025 huggingface dataset:
Unerwünschte Wirkungen im Gewässer: Gentoxizität als prioritärer Messparameter
Authors: Grummt Tamara , Hansen P.‐D. , Rettberg P. , Waldmann P. , Zipperle J.
Published: July 2004

Gentoxisch belastete aquatische Systeme sind eine potenzielle Gefahr für Mensch und Umwelt. Im Hinblick auf die weitreichenden Konsequenzen positiver Befunde für den regulatorischen Bereich, dessen Ziel es ist, Expositionen gegenüber gentoxischen Verbindungen zu verhindern oder soweit realisierbar gänzlich zu vermeiden, ist ein ausgereiftes experimentelles Konzept zwingend erforderlich. Die Biotests umu‐Test, Ames‐Test, Comet‐Assay, der DNA‐Aufwindungstest, die Alkalische Filterelution, der UDS‐Test und der Mikrokerntest sind ausreichend sensitiv, um gentoxische Effekte in komplexen Gemischen im Niedrig‐Dosis‐Bereich zu detektieren. Diese Tests lassen sich routinemäßig einsetzen und sollten daher Bestandteil der ersten Stufe einer Testbatterie zur Anzeige gentoxischen Gefährdungspotenzials in aquatischen Systemen sein.
Farbenfroher Nilpferd‐Schweiß
Authors: Jacoby Petra
Published: July 2004

Nilpferde schwitzen ganz besonders – in rot und orange. Eine Studie zeigt jetzt, dass der bunte Schweiß nicht nur die Körpertemperatur reguliert, sondern gleichzeitig ein antibiotischer Sonnenschutz ist.
Ein Modellbaukasten für Chemiker?
Authors: Schiller Carsten , Epple Matthias
Published: July 2004

Das Verständnis der räumlichen Anordnung von Atomen, sei es in Molekülen oder in Festkörperstrukturen, ist ein wesentlicher Bestandteil der Chemie. Wir arbeiten dabei mit 2‐dimensionalen Projektionen auf dem Papier und übersetzen diese bewusst oder unbewusst in ein 3‐dimensionales Gedankenmodell. Unser Vorstellungsvermögen bedarf bei dieser Aufgabe mitunter etwas Unterstützung durch reale 3‐dimensionale Modelle, damit wir die geometrischen Aspekte richtig “begreifen” können. Molekülmodellbaukästen erfreuen sich daher großer Beliebtheit, besonders bei der Chemieausbildung in Schulen und Universitäten. Es können sich auch Baukastensysteme als sehr nützlich erweisen, die eigentlich gar nicht für die Chemie gedacht sind...
Cognitive therapy with people with intellectual disabilities: a selective review and critique
Authors: Sturmey Peter
Published: August 2004

The literature on cognitive therapy with people with intellectual disabilities was selectively reviewed, including application to problems such as anger management, depression and offending. The literature on anger management showed the most promise. The literature on depression was weak. Research on offenders was promising, but no controlled trials were found. Much of the literature incorrectly identified behavioral interventions as cognitive interventions. Many interventions, such as anger management, were in fact packages that included many behavioral interventions, such as relaxation and social skills training, alongside cognitive methods, such as cognitive restructuring. Hence, evaluations of anger management packages can not tell us anything about the effectiveness of cognitive therapy, since cognitive therapy is confounded with behavior therapy. Future directions for research include well controlled experimental trials to evaluate the effectiveness of these packages and the contribution of cognitive therapy to treatment outcome. Copyright © 2004 John Wiley & Sons, Ltd.
Cognitive–behaviour therapy for people with psychosis and mild intellectual disabilities: a case series
Authors: Haddock Gillian , Lobban Fiona , Hatton Chris , Carson Ruth
Published: August 2004

A number of recent studies have shown that individual cognitive–behaviour therapy can be effective in reducing the severity of psychotic symptoms in chronic treatment resistant schizophrenia. In addition, cognitive–behaviourally oriented family interventions have been shown to significantly reduce relapse in similar populations. However, the application of either individual or family CBT approaches has not been evaluated in people who have a psychotic illness and who also have intellectual disabilities. This paper describes how individual and family CBT for psychosis has been modified for people with a mild learning disability who have a diagnosis of schizophrenia and illustrates its use with five case studies. Copyright © 2004 John Wiley & Sons, Ltd.
Flow cytometry detection of Shiga toxins in the blood from children with hemolytic uremic syndrome
Authors: Tazzari Pier Luigi , Ricci Francesca , Carnicelli Domenica , Caprioli Alfredo , Tozzi Alberto E. , Rizzoni Gianfranco , Conte Roberto , Brigotti Maurizio
Published: August 2004

Background

Hemolytic uremic syndrome (HUS) is the main cause of acute renal failure in early childhood. Most cases are due to intestinal infections from Escherichia coli strains (STEC) which produce by Shiga toxin (Stxs). Stx1 and Stx2 produced by STEC in the gut are absorbed into the circulation and, after binding on polymorphonuclear leukocytes (PMNs), are targeted to renal endothelium. The aim of the present work was the development of a method to detect Stxs bound on circulating PMNs and to diagnose STEC infections in patients with HUS.

Methods

White blood cells isolated after erythrocytic lysis were incubated with anti‐Stxs mouse monoclonal antibodies in the presence of human serum to saturate Fc receptors on PMNs. After incubation with fluorescein isothiocyanate–goat anti‐mouse immunoglobulin G, flow cytometric analysis was used to demonstrate the cell‐bound fluorescence.

Results

The method was quick (3 h), sensitive (femtomoles), and capable of detecting both Stxs. The presence of Stxs was detected on PMNs from six patients with HUS: four patients had serologic or microbiological evidence of STEC infection, whereas the other two patients had no evidence of STEC infection when employing the standard diagnostic methods.

Conclusions

The method described is rapid, simple, and based on commercially available reagents, and it might be more sensitive than the standard methods for diagnosis of STEC infection. It also allows the detection of Stxs in blood, a key step to monitor the pathogenesis of HUS. © 2004 Wiley‐Liss, Inc.
Performance analysis of congestion avoidance algorithms with non‐zero MCR guarantee for ABR service in ATM networks
Authors: Jaruvitayakovit Tanun , Prapinmongkolkarn Prasit
Published: July 2004

This paper proposes a novel explicit rate allocation algorithm called Fast Rate Allocation Congestion Avoidance (FRACA) algorithm supporting non‐zero minimum cell rate (MCR). The non‐zero MCR guarantee strategy for ABR service in ATM networks focused in this paper is MCR plus equal share (The ATM Forum Traffic Management Specification, version 4.0. April 1996). The main goals for designing the algorithm are the fast convergence according to the max–min fairness criteria, fairness among all sessions, maximum network utilization while the switch queue length is properly controlled. At the same time, it should work well under a wide range of network conditions without the need for adjusting the algorithm parameters. The performance of the proposed algorithm is evaluated and compared with the Generic Weighted Fairness (GWF) ERICA + (J Comput Comm 2000; 149). Simulation results show that the proposed algorithm achieves the design goals in the evaluated scenarios. Copyright © 2004 John Wiley & Sons, Ltd.
Reduced intragraft mRNA expression of matrix metalloproteinases Mmp3, Mmp12, Mmp13 and Adam8, and diminished transplant arteriosclerosis in Ccr5‐deficient mice
Authors: Luckow Bruno , Joergensen Joanne , Chilla Silvia , Li Jian‐Ping , Henger Anna , Kiss Eva , Wieczorek Grazyna , Roth Lukas , Hartmann Nicole , Hoffmann Reinhard , Kretzler Matthias , Nelson Peter J. , de Lema Guillermo Pérez , Maier Holger , Wurst Wolfgang , Balling Rudi , Pfeffer Klaus , Gröne Hermann‐Josef , Schlöndorff Detlef , Zerwes Hans‐Günter
Published: July 2004

Experimental and human organ transplant studies suggest an important role for chemokine (C‐C‐motif) receptor‐5 (CCR5) in the development of acute and chronic allograft rejection. Because early transplant damage can predispose allografts to chronic dysfunction, we sought to identify potential pathophysiologic mechanisms leading to allograft damage by using wild‐type and Ccr5‐deficient mice as recipients of fully MHC‐mismatched heart and carotid‐artery allografts. Gene expression in rejecting heart allografts was analyzed 2 and 6 days after transplantation using Affymetrix GeneChips. Microarray analysis led to identification of four metalloproteinase genes [matrix metalloproteinase (Mmp)3, Mmp12, Mmp13 and a disintegrin and metalloprotease domain (Adam)8] with significantly diminished intragraft mRNA expression in Ccr5‐deficient mice at day 6. Accordingly, allografts from Ccr5‐deficient mice showed less tissue remodeling and hence better preservation of the myocardial architecture compared with allografts from wild‐type recipients. Moreover, survival of cardiac allografts was significantly increased in Ccr5‐deficient mice. Carotid artery allografts from Ccr5‐deficient recipients showed better tissue preservation, and significant reduction of neointima formation and CD3+ T cell infiltration. Ccr5 appears to play an important role in transplant‐associated arteriosclerosis that may involve metalloproteinase‐mediated vessel wall remodeling. We conclude that early tissue remodeling may be a critical feature in the predisposition of allografts to the development of chronic dysfunction.
Magnetic Properties of Lone‐Pair‐Containing, Sandwich‐Type Polyoxoanions: A Detailed Study of the Heteroatomic Effect
Authors: Stowe Ashley C. , Nellutla Saritha , Dalal Naresh S. , Kortz Ulrich
Published: July 2004

Magnetic susceptibility and high‐frequency EPR spectroscopy investigations were carried out on the isostructural family of tricopper(II)‐substituted, sandwich‐type polyoxotungstates [Cu3(H2O)3(α‐AsW9O33)2]12− (1), [Cu3(H2O)3(α‐SbW9O33)2]12− (2), [Cu3(H2O)3(α‐SeW9O33)2]10− (3), and [Cu3(H2O)3(α‐TeW9O33)2]10− (4) with the intention of examining the possible influence of the diamagnetic heteroatoms X (X = AsIII, SbIII, SeIV, TeIV) on the magnetic exchange properties of the three Cu2+ ions in the central belt. Magnetic susceptibility data indicate a single antiferromagnetic spin exchange constant J for the triangular Cu3 belts in 1−4. Variable‐temperature, W‐band (ca. 94 GHz) EPR spectra reveal that the Cu3 units have ST = 1/2 as the spin ground state with the excited state ST = 3/2 located within a few cm−1. We also determined the g matrix components for both the ST = 1/2 and 3/2 states. The zero‐field parameter D has been measured for the ST = 3/2 state, and its sign is shown to be positive for 1−4. From the analysis of the g matrix components for the molecular and the local Cu2+ site symmetry, the unpaired electrons are shown to occupy the 3dx2−y2 orbitals. The J values change from −1.36 to −1.04 cm−1 for 1 and 2, and from −1.52 to −1.48 cm−1 for 3 and 4, respectively. The g values follow a similar trend, but the D value for 4 implies a role of through‐space as well as through‐bond sources for the magnetic interactions in the Cu3 belt. Our results suggest that the heteroatoms, containing lone pairs, allow the fine tuning of the magnetic parameters of 1−4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Characterization of Mixed Phthalocyaninato and meso‐Tetrakis(4‐chlorophenyl)porphyrinato Triple‐Decker Complexes − Revealing the Origin of Their Electronic Absorptions
Authors: Sun Xuan , Li Renjie , Wang Daqi , Dou Jianmin , Zhu Peihua , Lu Fanli , Ma Changqin , Choi Chi‐Fung , Cheng Diana Y. Y. , Ng Dennis K. P. , Kobayashi Nagao , Jiang Jianzhuang
Published: July 2004

Two series of mixed phthalocyaninato and porphyrinato rare earth(III) triple‐decker complexes [M2(Pc)(TClPP)2] (1a−10a) and [M2(Pc)2(TClPP)] (1b−11b) [M = Y, La−Er except Ce and Pm; Pc = phthalocyaninate; TClPP = tetrakis(4‐chlorophenyl)porphyrinate] have been prepared by treating the half‐sandwich complexes [M(TClPP)(acac)] (acac = acetylacetonate), generated in situ from [M(acac)3]·nH2O and H2(TClPP), with Li2(Pc). All the triple‐decker complexes have been characterized by a wide range of spectroscopic and electrochemical methods. The molecular structures of [M2(Pc)(TClPP)2] (M = Y, Ho) have also been determined, and show a symmetrical disposition of ligands, with two outer domed TClPP and one inner Pc rings. A systematic investigation of the optical and electrochemical data of these complexes has revealed the nature of the HOMO and LUMO, as well as the origin of the electronic absorptions of these triple‐decker complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Amperometric Detection of Catechol and Catecholamines by Immobilized Laccase from DeniLite
Authors: Quan De , Shin Woonsup
Published: August 2004

DeniLite laccase immobilized Pt electrode was used for detection of catechol and catecholamines. The enzymatically oxidized substrates were measured amperometrically. The sensitivities are 210, 75, 60 and 45 nA/μM with the upper limits of linear ranges of 58, 40, 55 and 55 μM and the detection limits (S/N=3) of 0.07, 0.2, 0.3 and 0.4 μM for catechol, dopamine (DA), norepinephrine (NEPI) and epinephrine (EPI), respectively. The response time (t90%) is about 2 seconds for each substrate and the long‐term stability is around 40–50 days with retaining 80% of initial activity. The very fast response and the remarkable long‐term stability are the principal advantages of this sensor. In case of catechol, the pH response of the sensor is mainly determined by enzyme's pH profile, however, in case of catecholamines, both enzyme's pH profile and reversibility of the substrate are operated and the optimal pHs for NEPI and EPI shift towards acidic range compared to that for DA. The presence of ascorbic acid (<50 μM) did not interfere with the measurement.
Realization of Rhodium Metal‐Oxide Electrode in Indifferent Electrolytes
Authors: Juodkazytė J. , Juodkazis K.
Published: August 2004

The pH‐dependence of the stationary open‐circuit potentialEi=0stof rhodium electrode with a surface layer of anodically formed insoluble compounds has been studied in sulfate and phosphate solutions by means of cyclic voltammetry and chronopotentiometry. The range of potentials of the investigations performed has been confined to the region of rhodium electrochemical oxidation/reduction, i.e., 0.2<E<1.2 V (RHE) in order to prevent any possible interference of other reactions such as H2and O2evolution. It has been shown that rhodium electrode with a layer of surface compounds formed anodically atE<<1.23 V (RHE) behaves like a reversible metal‐oxide electrode within the range of pH values from ca. 1.0 to ca. 8.0. It has been presumed that the stationary potential of such electrode is determined by the equilibrium of the following electrochemical reaction: Rh+3H2O⇔︁Rh(OH)3+3H++3e−. The pH‐dependence of the reversible potential ofEelectrode has been found to be:E=Ei=0st=0.69−0.059 pH, V. In acid solutions (pH<2.0) rhodium hydroxide dissolves into the electrolyte, therefore, to reach equilibrium, the solution must be saturated with Rh(OH)3. This has been achieved by adding Rh3+ions in the form of Rh2(SO4)3. The solubility product of Rh(OH)3, estimated from the experimentalE−pH dependence obtained, is ca. 1.0×10−48, which is close to the value given in literature.
Pleistocene migration routes into the Americas: Human biological adaptations and environmental constraints
Authors: Hall Roberta , Roy Diana , Boling David
Published: July 2004

Theories about the routes and timing of human entry into the Americas during the Late Pleistocene usually involve models of lowered sea levels and ice‐free land in Beringia, supported by locations and dates of archeological sites in Northeastern Asia and Northwestern America. Recently, paleoecological reconstructions made possible by advances in geochronology and climatology have received attention. Now morphological adaptations and environmental constraints that affect human activities and physiology need to be considered. Physical accessibility to an area, important as it is, does not alone determine a migration route. In considering any route, anthropologists need to ask: What would it have been like to live in this environment? Did it provide an amenable climate that supported human health and comfort? Between 16,000 and 11,000 cal BP, did this route provide enough food resources and enough hours of sunlight for people with an Upper Paleolithic technology to make a living? We discuss these questions and show ways in which the coastal‐entry model is superior to the interior route through Beringia and an ice‐free corridor.
Has the combination of genetic and fossil evidence solved the riddle of modern human origins?
Authors: Pearson Osbjorn M.
Published: July 2004

Debate over the origin of modern humans continues without a clear end in sight. Currently, the genetic and fossil evidence is still used to support two different interpretations of the origin of modern humans. Some researchers claim that the genetic evidence is compatible with either an Out‐of‐Africa or a Multiregional model, while other scientists argue that the evidence supports only a Multiregional model of evolution. I argue that the fossil record and archeological evidence constrain interpretation of the genetic evidence and imply that very little, if any, admixture with Eurasian archaic hominins such as the Neanderthals occurred during the spread of modern humans out of Africa.
PBI‐Based Polymer Membranes for High Temperature Fuel Cells – Preparation, Characterization and Fuel Cell Demonstration
Authors: Li Q. , He R. , Jensen J.O. , Bjerrum N.J.
Published: July 2004

Proton exchange membrane fuel cell (PEMFC) technology based on perfluorosulfonic acid (PFSA) polymer membranes is briefly reviewed. The newest development in alternative polymer electrolytes for operation above 100 °C is summarized and discussed. As one of the successful approaches to high operational temperatures, the development and evaluation of acid doped polybenzimidazole (PBI) membranes are reviewed, covering polymer synthesis, membrane casting, acid doping, physicochemical characterization and fuel cell testing. A high temperature PEMFC system, operational at up to 200 °C based on phosphoric acid‐doped PBI membranes, is demonstrated. It requires little or no gas humidification and has a CO tolerance of up to several percent. The direct use of reformed hydrogen from a simple methanol reformer, without the need for any further CO removal, has been demonstrated. A lifetime of continuous operation, for over 5000 h at 150 °C, and shutdown‐restart thermal cycle testing for 47 cycles has been achieved. Other issues such as cooling, heat recovery, possible integration with fuel processing units, associated problems and further development are discussed.
CO Tolerance of Commercial Pt and PtRu Gas Diffusion Electrodes in Polymer Electrolyte Fuel Cells
Authors: Hajbolouri F. , Andreaus B. , Scherer G.G. , Wokaun A.
Published: July 2004

The CO tolerance of commercial Pt and PtRu anode electrodes from different suppliers (E‐Tek and Tanaka) has been examined in polymer electrolyte fuel cells (PEFC) using AC‐impedance spectroscopy along steady‐state current‐voltage curves. A simple mathematical model has been derived in order to extract important kinetic parameters for CO poisoning on different anode electrodes. The Tanaka PtRu (40:60) electrode demonstrated the best CO tolerance under the selected operating conditions.

Inductive behavior in the low frequency region of the impedance spectra for the E‐Tek Pt and PtRu electrode proved to be characteristic for CO poisoning. However, the impedance spectra of the Tanaka PtRu electrode did not show any inductive behavior and its CO surface coverage, extracted by fitting the experimental data to the model, was lower than the surface CO coverage of the E‐Tek electrodes.
Hydrogen Production via Autothermal Reforming of Diesel Fuel
Authors: Pasel J. , Meißner J. , Porš Z. , Palm C. , Cremer P. , Peters R. , Stolten D.
Published: July 2004

Hydrogen, for the operation of a polymer electrolyte fuel cell, can be produced by means of autothermal reforming of liquid hydrocarbons. Experiments, especially with ATR 4, which produces a molar hydrogen stream equivalent to an electrical power in the fuel cell of 3 kW, showed that the process should be preferably run in the temperature range between 700 ° and 850 °. This ensures complete hydrocarbon conversion and avoids the formation of considerable amounts of methane and organic compounds in the product water. Experiments with commercial diesel showed promising results but insufficient long‐term stability. Experiments concerning the ignition of the catalytic reaction inside the reformer proved that within 60 s after the addition of water and hydrocarbons the reformer reached 95% of its maximum molar hydrogen flow. Measurements, with respect to reformer start‐up, showed that it takes approximately 7 min. to heat up the monolith to a temperature of 340 ° using an external heating device. Modelling is performed, aimed at the modification of the mixing chamber of ATR Type 5, which will help to amend the homogeneous blending of diesel fuel with air and water in the mixing chamber.
The contribution of a satellite market to price discovery: Evidence from the Singapore exchange
Authors: Covrig Vicentiu , Ding David K. , Low Buen Sin
Published: July 2004

The Singapore Exchange (SGX), a small satellite market, successfully competes with a large home market, the Osaka Securities Exchange (OSE), in trading the Nikkei 225 futures index. In this paper, we investigate the contribution of the SGX to price discovery and shed light on the reasons for its continued success. Evidence is provided from information revelation and price discovery of three competing but informationally linked markets of the Nikkei 225 index—domestic spot (Tokyo Stock Exchange), domestic futures (OSE), and foreign futures (SGX), which represents the satellite market. Overall, the futures market contributes 77% to price discovery, with the satellite market contributing 42% of the futures and 33% of the total price discovery. These figures, surprisingly, far exceed the satellite market's share of trading volume. Support is provided for the extended trading hours on the SGX for three of the four non‐overlapping trading sub‐periods. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:981–1004, 2004
Liquidity constraints and the hedging role of futures spreads
Authors: Wong Kit Pong
Published: July 2004

This paper examines the behavior of the competitive firm under price uncertainty in general and the hedging role of futures spreads in particular. The firm has access to a commodity futures market where unbiased nearby and distant futures contracts are transacted. A liquidity constraint is imposed on the firm such that the firm is forced to prematurely close its distant futures position whenever the net interim loss due to its nearby and distant futures positions exceeds a threshold level. This paper shows that the liquidity constrained firm optimally opts for a long nearby futures position and a short distant futures position should the firm be prudent, thereby rendering the optimality of using futures spreads for hedging purposes. This paper further shows that the firm's production decision is adversely affected by the presence of the liquidity constraint. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:909–921, 2004
Unequivocal evidence of genotoxic potential of argemone oil in mice
Authors: Ansari Kausar M. , Chauhan Lalit K.S. , Dhawan Alok , Khanna Subhash K. , Das Mukul
Published: August 2004

Consumption of mustard oil adulterated with argemone oil leads to a clinical condition, commonly referred to as “Epidemic Dropsy.” Since in vitro studies have shown that sanguinarine, an active benzophenanthridine alkaloid of argemone oil, intercalates DNA molecule, the in vivo clastogenic and DNA damaging potential of argemone oil was investigated in mice. Swiss albino mice were intraperitoneally administered 0.5, 1.0, 2.0 and 4.0 ml/kg body wt. of argemone oil to analyze chromosome aberrations and micronucleus test, while 0.25, 0.5, 1.0 and 2.0 ml/kg body wt. were given for alkaline comet assay. The frequencies of chromosomal aberrations and micronucleated erythrocytes formation in mouse bone marrow cells increased in a dose‐dependent manner following argemone oil treatment. However, significant induction in chromosomal aberrations (83%) and micronucleated erythrocytes formation (261%) were observed at a minimum dose of 1.0 ml/kg. The results of comet assay revealed DNA damage in blood, bone marrow and liver cells following argemone oil treatment. Olive tail moment (OTM) and tail DNA showed significant increase in bone marrow (35–44%) and blood cells (25–40%) even at a dose of 0.25 ml/kg body wt. of argemone oil. In liver cells, OTM was significantly increased (20%) at a dose of 0.25 ml/kg, while all the comet parameters including OTM, tail length and tail DNA showed significant increase (31–101%) at a dose of 0.5 ml/kg. These results clearly suggest that single exposure of argemone oil even at low doses produces genotoxic effects in mice. © 2004 Wiley‐Liss, Inc.
Sonographic assessment of the liver in children with psoriasis
Authors: Pietrzak Aldona , Dybiec Ewa , Urban Janusz , Chodorowska Grażyna
Published: July 2004

Purpose

The aim of this study was to compare the size and echotexture of the liver in psoriatic and healthy children.

Methods

In 70 psoriatic and 43 healthy children, longitudinal sonograms of the liver were obtained along standardized section planes defined by the anterior axillary line, medioclavicular line, and midline. The livers' size and echotexture were examined and compared between the study groups.

Results

The measurements of the liver along the 3 section planes were not significantly different between psoriatic and healthy children. Parenchymal liver echogenicity in psoriatic children was neither decreased nor increased.

Conclusions

No abnormality in size or echotexture of the liver was found in the psoriatic children. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:344–347, 2004
Comparative cis‐regulatory analyses identify new elements of the mouse Hoxc8 early enhancer
Authors: Wang Wayne C.H. , Anand Sanjay , Powell Dennis R. , Pawashe Aruna B. , Amemiya Chris T. , Shashikant Cooduvalli S.
Published: July 2004

The Hoxc8 early enhancer is a 200 bp region that controls the early phase of Hoxc8 expression during mouse embryonic development. This enhancer defines the domain of Hoxc8 expression in the neural tube and mesoderm of the posterior regions of the developing embryo. Five distinct cis‐acting elements, A–E, were previously shown to govern early phase Hoxc8 expression. Significant divergence between mammalian and fish Hoxc8 early enhancer sequences and activities suggested additional cis‐acting elements. Here we describe four additional cis‐acting elements (F‐I) within the 200 bp Hoxc8 early enhancer region identified by comparative regulatory analysis and transgene‐mutation studies. These elements affect posterior neural tube and mesoderm expression of the reporter gene, either singly or in combination. Surprisingly, these new elements are missing from the zebrafish and Fugu Hoxc8 early enhancer sequences. Considering that fish enhancers direct robust reporter expression in transgenic mouse embryos, it is tempting to postulate that fish and mammalian Hoxc8 early enhancers utilize different sets of elements to direct Hoxc8 early expression. These observations reveal a remarkable plasticity in the Hoxc8 early enhancer, suggesting different modes of initiation and establishment of Hoxc8 expression in different species. We postulate that extensive restructuring and remodeling of Hox cis‐regulatory regions occurring in different taxa lead to relatively different Hox expression patterns, which in turn may act as a driving force in generating diverse axial morphologies. J. Exp. Zool. (Mol. Dev. Evol.) 302B:000–000, 2004. © 2004 Wiley‐Liss, Inc.
Transient complexes of redox proteins: structural and dynamic details from NMR studies
Authors: Prudêncio Miguel , Ubbink Marcellus
Published: August 2004

Redox proteins participate in many metabolic routes, in particular those related to energy conversion. Protein–protein complexes of redox proteins are characterized by a weak affinity and a short lifetime. Two‐dimensional NMR spectroscopy has been applied to many redox protein complexes, providing a wealth of information about the process of complex formation, the nature of the interface and the dynamic properties of the complex. These studies have shown that some complexes are non‐specific and exist as a dynamic ensemble of orientations while in other complexes the proteins assume a single orientation. The binding interface in these complexes consists of a small hydrophobic patch for specificity, surrounded by polar, uncharged residues that may enhance dissociation, and, in most complexes, a ring or patch of charged residues that enhances the association by electrostatic interactions. The entry and exit port of the electrons is located within the hydrophobic interaction site, ensuring rapid electron transfer from one redox centre to the next. Copyright © 2004 John Wiley & Sons, Ltd.
Sensorial and physicochemical quality responses of pears (cv Rocha) to long‐term storage under controlled atmospheres
Authors: Galvis‐Sánchez Andrea C , Fonseca Susana C , Morais Alcina MMB , Malcata F Xavier
Published: August 2004

Pears (cv Rocha) kept under controlled atmospheres (CA) and air were evaluated after long‐term storage in terms of sensory attributes and physicochemical parameters, namely colour, firmness, polyphenoloxidase (PPO) activity and concentration of hydroxycinnamic compounds. The CA conditions were all combinations of 2 and 4% (v/v) O2 with 0.5 and 1.5% (v/v) CO2. Storage under CA conditions produced a beneficial effect on ‘Rocha’ pears in maintaining their quality and, consequently, in extending their shelf life and acceptability. Clear differences in sensorial attributes, colour parameters and PPO activity were found between CA‐ and air‐stored pears. The effect provided by the CA conditions persisted throughout the time of exposure to the open air. The 2% O2 concentration produced a more beneficial effect than its 4% counterpart on the sensorial and physical characteristics of the pears. The former concentration of O2 prevented yellowing and allowed regular softening, hence keeping a high flavour quality. No clear effects could be associated with CO2 levels. Empirical models were developed that describe the effects of O2 and CO2 concentrations, as well as time at room temperature on physicochemical parameters pertaining to ‘Rocha’ pears. Copyright © 2004 Society of Chemical Industry
The effect of daily temperature on truss flowering rate of tomato
Authors: Pék Zoltán , Helyes Lajos
Published: August 2004

The rate of appearance of tomato inflorescence is important parameter of yield prediction models. Number of macroscopically observable inflorescences related to unit time was used to characterize the rate of development in case of indeterminate tomato. Truss flowering rate showed similar pattern to truss appearance rate, and it was closely connected with temperature. The present experiments attempted to calculate functions that can estimate truss flowering rate up to the 10th truss. These functions are the basis of characterizing the whole flowering process in relation to temperature during the generative period of indeterminate tomato. Copyright © 2004 Society of Chemical Industry
Sensory and chemical characteristics of Canadian ice wines
Authors: Nurgel Canan , Pickering Gary J , Inglis Debra L
Published: August 2004

Fifty‐one Canadian ice wines, representative of a range of varieties and vintages, were evaluated chemically and 20 wines further evaluated sensorally. Ice wines from British Columbia and Ontario were significantly different for a range of chemical and sensory attributes. British Columbia ice wines had higher titratable acidity, acetic acid and glucose, and lower colour and ethyl acetate content compared with those from Ontario. Apricot, raisin, honey and oak aromas were more pronounced in Ontario ice wines, while British Columbia ice wines had higher intensities of pineapple and oxidized aromas. Riesling ice wines had higher titratable acidity and glucose and lower pH andA420values compared with Vidal. Vintage effects were also found for pH,A420, glucose, fructose, ethanol and ethyl acetate. Copyright © 2004 Society of Chemical Industry
In‐gel detection and study of the role of flavonol 3‐glucosidase in the bitter taste generation in tartary buckwheat
Authors: Suzuki Tatsuro , Honda Yutaka , Funatsuki Wakako , Nakatsuka Keiji
Published: August 2004

The present study demonstrated that flavonol 3‐glucosidase (f3g) is an important cause of bitter taste generation in tartary buckwheat (Fagopyrum tataricum) flour using the f3g complement test. To screen the f3g deletion line, which must have little bitter taste, an in‐gel method to detect individual f3g isozymes in tartary buckwheat seeds was developed. The f3g isozymes in tartary buckwheat seed were stained using a rutin–copper complex on the native–PAGE gel. This method was able to clearly detect as little as 1.4 ng of individual f3g isozymes within 20 min following electrophoresis. With this method, screening of the f3g deletion line can be conducted efficiently and will result in a better taste in tartary buckwheat flour. Copyright © 2004 Society of Chemical Industry
Assessment of two‐ and three‐parameter Lewicki models for description of sorption phenomena of starch materials
Authors: McMinn Wendy AM , Al‐Muhtaseb Ala'a , Magee T Ronald A
Published: August 2004

Experimental moisture sorption isotherm data for raw potato, starch gels (potato, starch–sugar and starch–salt) and starch powders (potato, highly amylopectin and highly amylose) were determined using a gravimetric static method at 30, 45 and 60 °C and over a relative humidity range 0.10–0.84. The raw potato, starch powders and starch gels exhibited type II behaviour, with type III form being observed on incorporation of sugar, or salt, into the starch gel matrix. The two‐parameter Lewicki relationship, and the three‐parameter Lewicki and GAB equations were considered for description of the experimental data. A nonlinear least square regression technique was used to evaluate the constants for the models. The three‐parameter Lewicki model was found to be the most suitable for describing the sorption characteristics of raw potato, potato starch, starch–sugar and starch–salt gels within the investigated temperature and water activity range. However, both Lewicki models gave an inadequate representation of the data for potato, high amylopectin and high amylose starch powders. Copyright © 2004 Society of Chemical Industry
Dietary evaluation of Mediterranean fish and molluscs pan‐fried in virgin olive oil
Authors: Kalogeropoulos Nick , Andrikopoulos Nikolaos K , Hassapidou Maria
Published: August 2004

The effect of domestic pan‐frying in virgin olive oil (VOO) on the proximate composition, energy content, cholesterol, squalene and fatty acids in the edible portion of six species of finfish, common squid and mussels just caught from several regions of the Aegean Sea (Mediterranean Sea) was investigated. The species selected are traditionally consumed pan‐fried in VOO by the Greeks. On a fresh weight basis, pan‐frying caused significant water loss and increase of total fat, crude protein and energy content. The amount of VOO absorbed during frying ranged from 4.5 to 14.2% of fresh matter, showing a non‐linear negative correlation with initial fat, fish length and fish weight. Cholesterol content increased from 25 to 106 mg 100 g−1 fresh weight (fw) to 33–130 mg 100 g−1 fw after frying. VOO absorbed during frying resulted in a 20–78 times increase of squalene content and in significant alteration of fatty acid composition, the major change being the increase of monounsaturated fatty acids which became predominant in all fried samples. The intakes of fat and major fatty acid classes by consuming the pan‐fried seafood were comparable with the respective average Greek values. Frying in VOO resulted in a two to three times decrease of the atherogenic index and a slightly less decrease of the thrombogenic index. Both indices remained lower than 0.45 in all fried samples. The cholesterol‐saturated fat index and the cholesterol index increased up to twice after frying, ranging between 3.4–9.9 and 2.9–9.3, respectively. From the results obtained it is concluded that fish and shellfish pan‐fried in VOO present a healthy lipid profile in terms of the n‐6/n‐3 ratio, major fatty acid classes and total fat content. Copyright © 2004 Society of Chemical Industry
Characterisation of avocado (Persea americana Mill) honeys by their physicochemical characteristics
Authors: Terrab Anass , Heredia Francisco J
Published: August 2004

The quality of 12 avocado (Persea americana Mill) honeys from Spain was evaluated. Eight common physicochemical parameters were analysed, namely water content, pH, acidity (free, lactonic and total), sugar content, ash content and electrical conductivity. In addition, the honey samples were analysed using inductively coupled plasma optical emission spectrometry (ICP‐OES), and six minerals were quantified for each honey, namely potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), phosphorus (P) and sulphur (S). Most samples showed proper maturity considering the medium water content (mean 17.7%). The total acidity (below 50 meq kg−1 except for one sample) indicated absence of undesirable fermentation; also, the mean pH of around 4.77 is usual in this kind of honey. The values for ash content and electrical conductivity were high (0.77% and 798 µS cm−1 respectively) and typical of dark honeys. K was the predominant mineral (accounting for 73% of the total minerals quantified), followed by Na (10%). Copyright © 2004 Society of Chemical Industry
Study of the mechanism of enantioseparation Part VI: Thermodynamic study of HPLC separation of some enantiomers of phenylcarbamic acid derivatives on a (S,S) Whelk‐O 1 column
Authors: Dungelová Jana , Lehotay Jozef , Krupčík Jan , Cižmárik Jozef , Armstrong Daniel W.
Published: July 2004

The enantiomers of thirteen 2‐, 3‐, and 4‐alkoxyphenylcarbamic acid 2‐methoxy‐1‐[(4‐methylpiperazino)methyl]ethyl ester were separated on a (S,S) Whelk‐O 1 CSP column isothermally in the range of 0–50°C at 10°C increments, using methanol/water (90/10, v/v) containing 17.5 mmol L–1 acetic acid and 14.36 mmol L–1 triethylamine as a mobile phase. The dependence of the natural logarithms of retention and selectivity factors (ln k, ln α, respectively) on the inverse of temperature, 1/T, was used to determine thermodynamic data of enantiomers of alkoxysubstituted phenylcarbamic acid 2‐methoxy‐1‐[(4‐methylpiperazino) methyl]ethyl esters. Enthalpy‐entropy compensation plots showed that all of the compounds in this study separate via the same enthalpy‐driven chiral recognition mechanism.
Multi‐criteria decision making in micellar liquid chromatographic separation of chlorophenols
Authors: Hadjmohammadi Mohammad Reza , Safa Fariba
Published: July 2004

Simultaneous optimization of separation quality and analysis time of the micellar liquid chromatography of nine chlorophenol isomers was investigated. The effect on retention of three experimental parameters was studied using multivariate analysis. The factors studied were the concentration of sodium dodecyl sulfate, propanol content, and pH of the mobile phase. The experiments were performed according to the face‐centered cube central composite design and the inverse form of the experimental retention times of analytes was fitted to polynomial models. The results of the analysis of variance showed that the models obtained explain over 99% of the variance observed in the chromatograms. The good predictive ability of the models was verified by high correlation coefficient (R 2 > 0.99) and F ratio values for the plots of predicted cross‐validated versus experimental retention times. The study showed that the use of the Pareto‐Optimality method, an approach from multi‐criteria decision making, allows selection of the best possible combinations of separation quality and analysis time in micellar liquid chromatography of chlorophenols.
Resolution of triacylglycerol positional isomers by reversed‐phase high‐performance liquid chromatography
Authors: Momchilova Svetlana , Tsuji Koichiro , Itabashi Yutaka , Nikolova‐Damyanova Boryana , Kuksis Arnis
Published: July 2004

The ability of reversed‐phase high‐performance liquid chromatography (RP‐HPLC) to separate some positionally isomeric disaturated and monounsaturated triacylglycerols (TAGs) as intact species is demonstrated for the first time. Mobile phases of acetonitrile modified with methanol, ethanol, 2‐propanol, 1‐propanol, 1‐butanol, acetone, or dichloromethane were tested for the separation of POP‐PPO, PLP‐PPL, PEP‐PPE, and PDP‐PPD (P – palmitic, O – oleic, L – linoleic, E – eicosapentaenoic, D – docosahexaenoic acid residue) on a single RP‐HPLC column. The resolution improved with increasing number of double bonds in the acyl residues. While POP and PPO were only partially resolved, PDP and PPD were fully separated with all tested mobile phases, except those containing methanol. Also separated were the four TAGs having the same equivalent carbon number (ECN = 42), PEP, PPE, PDP, and PPD, on a single RP‐HPLC column with mobile phase acetonitrile–2‐propanol (70:30, v/v) at 0.8 mL/min. In all cases the isomer with the unsaturated acyl residue in either 1‐ or 3‐position was retained more strongly than the respective 2‐isomer.
Pesticide analysis by capillary electrophoresis
Authors: Hernández‐Borges J. , Frías‐García S. , Cifuentes A. , Rodríguez‐Delgado M.A.
Published: July 2004

In this work, a critical and updated revision of the current situation of the analysis of pesticides by Capillary Electrophoresis (CE) is presented. The review has been written in two main sections. The first one presents a thorough revision of the various off‐line and on‐line sample preconcentration procedures that have been used in conjunction with CE to analyze these compounds. The second part reviews the various detection strategies (i. e., UV, LIF, MS, and electrochemical) and CE modes that have been applied to the analysis of pesticides. Future trends that can be expected from this hot research area are also discussed.
Kinetics and mechanism of the oxidation of iron(II) ion by chlorine dioxide in aqueous solution
Authors: Moore Evan R. , Bourne Andrew E. , Hoppe Todd J. , Abode Philip J. , Boone Steven R. , Purser Gordon H.
Published: August 2004

The mechanism by which an excess of iron(II) ion reacts with aqueous chlorine dioxide to produce iron(III) ion and chloride ion has been determined. The reaction proceeds via the formation of chlorite ion, which in turn reacts with additional iron(II) to produce the observed products. The first step of the process, the reduction of chlorine dioxide to chlorite ion, is fast compared to the subsequent reduction of chlorite by iron(II). The overall stoichiometry is

equation image

The rate is independent of pH over the range from 3.5 to 7.5, but the reaction is assisted by the presence of acetate ion. Thus the rate law is given by

equation image

At an ionic strength of 2.0 M and at 25°C, ku = (3.9 ± 0.1) × 103 L mol−1 s−1 and kc = (6 ± 1) × 104 L mol−1 s−1. The formation constant for the acetatoiron(II) complex, Kf, at an ionic strength of 2.0 M and 25°C was found to be (4.8 ± 0.8) × 10−2 L mol−1. The activation parameters for the reaction were determined and compared to those for iron(II) ion reacting directly with chlorite ion. At 0.1 M ionic strength, the activation parameters for the two reactions were found to be identical within experimental error. The values of ΔH‡ and ΔS‡ are 64 ± 3 kJ mol−1 and + 40 ± 10 J K−1 mol−1 respectively. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 554–565, 2004
An updated comprehensive kinetic model of hydrogen combustion
Authors: Li Juan , Zhao Zhenwei , Kazakov Andrei , Dryer Frederick L.
Published: August 2004

A comprehensively tested H2/O2 chemical kinetic mechanism based on the work of Mueller et al. 1 and recently published kinetic and thermodynamic information is presented. The revised mechanism is validated against a wide range of experimental conditions, including those found in shock tubes, flow reactors, and laminar premixed flame. Excellent agreement of the model predictions with the experimental observations demonstrates that the mechanism is comprehensive and has good predictive capabilities for different experimental systems, including new results published subsequent to the work of Mueller et al. 1, particularly high‐pressure laminar flame speed and shock tube ignition results. The reaction H + OH + M is found to be primarily significant only to laminar flame speed propagation predictions at high pressure. All experimental hydrogen flame speed observations can be adequately fit using any of the several transport coefficient estimates presently available in the literature for the hydrogen/oxygen system simply by adjusting the rate parameters for this reaction within their present uncertainties. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 566–575, 2004
Null‐solutions for partial differential operators with several Fuchsian variables
Authors: Belarbi Malika , Mandai Takeshi , Mechab Mustapha
Published: August 2004

K. Igari has constructed a distribution null‐solution for Fuchsian partial differential operators in the sense of Baouendi‐Goulaouic, that is, operators with one Fuchsian variable. Our aim is to extend his result for operators having several Fuchsian variables with analytic coefficients defined by N. S. Madi. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On convolutions of Siegel modular forms
Authors: Imamoğlu Özlem , Martin Yves
Published: August 2004

In this article we study a Rankin‐Selberg convolution of n complex variables for pairs of degree n Siegel cusp forms. We establish its analytic continuation to ℂn, determine its functional equations and find its singular curves. Also, we introduce and get similar results for a convolution of degree n Jacobi cusp forms.

Furthermore, we show how the relation of a Siegel cusp form and its Fourier‐Jacobi coefficients is reflected in a particular relation connecting the two convolutions studied in this paper. As a consequence, the Dirichlet series introduced by Kalinin [7] and Yamazaki [19] are obtained as particular cases. As another application we generalize to any degree the estimate on the size of Fourier coefficients given in [14]. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real interpolations for Besov and Triebel‐Lizorkin spaces on spaces of homogeneous type
Authors: Yang Dachun
Published: August 2004

The author establishes a full real interpolation theorem for inhomogeneous Besov and Triebel‐Lizorkin spaces on spaces of homogeneous type. The corresponding theorem for homogeneous Besov and Triebel‐Lizorkin spaces is also presented. Moreover, as an application, the author gives the reduced T1 theorem for homogeneous Besov spaces on spaces of homogeneous type. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)