bluuebunny/crossref_metadata_2025 huggingface dataset:
Function of RARγ and RARα2 at the initiation of retinoid signaling is essential for avian embryo survival and for distinct events in cardiac morphogenesis
Authors: Romeih Mahmoud , Cui Jian , Michaille Jean‐Jacques , Jiang Weihong , Zile Maija H.
Published: December 2003

Avian embryogenesis requires retinoid receptor activation by the vitamin A active form, retinoic acid (RA), during neurulation. We conducted loss‐of‐function analysis in quail embryos by nutritional deprivation of RA and by blocking generation of retinoid receptors. Here we identify a distinct role for RARα2 in cardiac inflow tract morphogenesis and for RARγ in cardiac left/right orientation and looping morphogenesis. Blocking normal embryos with antisense oligonucleotides to RARα2 or RXRα diminishes GATA‐4 transcripts, while blocking RARγ or RXRα diminishes nodal and Pitx2 transcripts; the expression of these genes in the heart forming region resembles that of the vitamin A‐deficient embryo. Blocking the function of RARγ, RARα2, and RXRα recapitulates the complete vitamin A‐deficient phenotype. RARγ is the most potent mediator of the retinoid signal at this time of development. Our studies provide strong evidence that critical RA‐requiring developmental events in the early avian embryo are regulated by means of distinct retinoid receptor signaling pathways. Developmental Dynamics 228:697–708, 2003. © 2003 Wiley‐Liss, Inc.
Generation of structures formed by lens and retinal cells differentiating from embryonic stem cells
Authors: Hirano Mariko , Yamamoto Akitsugu , Yoshimura Naoko , Tokunaga Tomoyuki , Motohashi Tsutomu , Ishizaki Katsuhiko , Yoshida Hisahiro , Okazaki Kenji , Yamazaki Hidetoshi , Hayashi Shin‐Ichi , Kunisada Takahiro
Published: December 2003

Embryonic stem cells have the potential to give rise to all cell lineages when introduced into the early embryo. They also give rise to a limited number of different cell types in vitro in specialized culture systems. In this study, we established a culture system in which a structure consisting of lens, neural retina, and pigmented retina was efficiently induced from embryonic stem cells. Refractile cell masses containing lens and neural retina were surrounded by retinal pigment epithelium layers and, thus, designated as eye‐like structures. Developmental processes required for eye development appear to proceed in this culture system, because the formation of the eye‐like structures depended on the expression of Pax6, a key transcription factor for eye development. The present culture system opens up the possibility of examining early stages of eye development and also of producing cells for use in cellular therapy for various diseases of the eye. Developmental Dynamics 228:664–671, 2003. © 2003 Wiley‐Liss, Inc.
Synthesis, Structure and Magnetic Properties of the Cobalt(II) 1,1′‐Biphenyl‐2,2′‐dicarboxylate Hydroxide Chain Compound [Co3{O2CC12H8CO2}2.5(OH)(H2O)2]n
Authors: Rueff Jean‐Michel , Pillet Sébastien , Bonaventure Gautier , Souhassou Mohamed , Rabu Pierre
Published: December 2003

A new 1D compound [Co3(O2CC12H8CO2)2.5(OH)(H2O)2] (2) was synthesised with the hydrothermal method from Co(NO3)2·6H2O, 1,1′‐biphenyl‐2,2′‐dicarboxylic acid, and KOH under hydrothermal conditions. Its structure was solved by single‐crystal X‐ray diffraction analysis. Compound 2 crystallises as purple crystals with the monoclinic cell (C2/c) a = 19.370(1), b = 14.5350(9), c = 22.583(1) Å, β = 89.910(4)°. The structure consists of chains of butterfly motifs of CoII ions in both octahedral and tetrahedral oxygen sites. The structural, IR and UV spectroscopic data and magnetic behaviour are presented and compared to that of the parent pink compound 1, obtained under slightly different stoichiometric conditions. Ligand‐field characteristics, Dq ≈︁ 1146 cm−1 and B ≈︁ 811 cm−1 for the octahedral sites, and Dq ≈︁ 434 cm−1 and B ≈︁ 782 cm−1 for CoII in the tetrahedral sites, were deduced from the electronic spectra and related to the structural and magnetic findings. From the magnetic point of view, the occurrence of efficient Co−O−Co superexchange pathways contributes to significant antiferromagnetic coupling between the cobalt(II) ions along the chains. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Bent and Linear Forms of the (μ‐Oxo)bis[trichloroferrate(III)] Dianion: An Intermolecular Effect − Structural, Electronic and Magnetic Properties
Authors: Lledós Agustí , Moreno‐Mañas Marcial , Sodupe Mariona , Vallribera Adelina , Mata Ignasi , Martínez Benjamín , Molins Elies
Published: December 2003

We have analyzed the great diversity of Fe−O−Fe angles, 140−180°, found in the X‐ray structures of the (μ‐oxo)bis[trichloroferrate(III)] dianion [Cl3FeOFeCl3]2− from both experimental and theoretical points of view. Theoretical calculations show that only the linear isomer is found as a minimum on the potential energy surface. Detailed analysis of the crystal packing indicates that the angular form is due to attractive intermolecular interactions. Analysis of a selected reduced set of the 45 crystal structures retrieved from the Cambridge Structural Database allowed us to classify the bending of the [Cl3FeOFeCl3]2− dianion in three categories, depending on the balance and strength of the intermolecular O···H−X contacts. A crystal diffraction study on the bis(benzyltrimethylammonium) salt has shown both bent (144.6°) and linear (180°) forms of the (μ‐oxo)bis[trichloroferrate(III)] dianion. The magnetic susceptibility of this compound has been fitted by assuming two equally weighted contributions (Jang and Jlin) of the two forms, considering Jang − Jlin estimated by theoretical calculations. The obtained Jang and Jlin of −117 and −133 cm−1 respectively, agree well with B3LYP results. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Ab initio Study on Luminescence and Aurophilicity of a Dinuclear [(AuPH3)2(i‐mnt)] Complex (i‐mnt = isomer‐Malononitriledithiolate)
Authors: Pan Qing‐Jiang , Zhang Hong‐Xing
Published: December 2003

The luminescence and Au−Au aurophilicity of the model complex, [(AuPH3)2(i‐mnt)] (i‐mnt = isomer‐malononitriledithiolate in both solid state and solution have been studied by ab initio methods. The structures of the AuI complex were fully optimized by the MP2 method for the ground state and the CIS method for the excited state. The b3A′ excited‐state Au−Au (2.946 Å) and the corresponding Au−Au stretching frequency (83 cm−1) indicate intramolecular Au−Au aurophilicity. Using [(AuPH3)2(i‐mnt)]2 to rationalize the solid‐state emission to the [(AuPPh3)2(i‐mnt)] complex at 20 K we assigned the experimental emission (462 nm) to an Au−Au⇄i‐mnt charge‐transfer (3MMLCT) transition from the triplet excited state to the ground state. In the 3MMLCT emissive excited state, the Au−Au aurophilicity, including intra‐ and intermolecular Au−Au interactions, results in a ca. 120 nm red shift in emission relative to that of mononuclear PH3AuSH. The calculated absorption and emission in dichloromethane solution agree with the experimental results. These results, combined with our previous studies on both [Au2(dpm)2]2+ [dpm = bis(diphosphanyl)methane] and [Au2(dpm)(i‐mnt)], indicate a clear correlation between Au−Au aurophilicity and the excited‐state properties of the dinuclear AuI complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Recent progress in pharmacokinetic applications of capillary electrophoresis
Authors: Lin Chun‐Che , Li Yu‐Ting , Chen Shu‐Hui
Published: December 2003

This review is a continuation of the previous reviews (Electrophoresis1999,20, 3259–3268;Electrophoresis2001,22, 4244–4248) to update the recent publications from 2001 to 2003 on pharmacokinetic studies using capillary electrophoresis (CE). During this period of time, CE remains as a unique analytical method for some studies, which would otherwise be limited by many factors, such as the sample volume, detection sensitivity, or separation power. It is particularly noticeable that the separation of chiral drugs in biological sample and the use of solid‐phase extraction (SPE) as a simple and convenient means of sample preparation appear to become popular for CE‐based assays. The use of CE for assessing complete pharmacokinetic information, however, did not show a significant growth during this period of time. In order to provide a broad range of view on how biological samples are analyzed by CE, this review will cover publications during the past two years on the use of CE for the analysis of drugs in biological fluids for general pharmacokinetic applications including drug monitoring and bioavailability studies.
Recent applications of microemulsion electrokinetic chromatography
Authors: Hansen Steen Honoré
Published: December 2003

Microemulsions are used in a similar way as micellar solutions are used for separations in capillary electrophoresis. Within the last ∼ six years, a number of papers have appeared in the literature in which the separation characteristics of microemulsion electrokinetic chromatography (MEEKC) have been investigated. The total number of papers dealing with MEEKC is now close to 100. One of the major fields of application for MEEKC has been the characterization of the lipophilicity of chemical substances but the technique has also been applied for the analysis of substances within the fields of natural products, pharmaceuticals, vitamins, peptides, proteins, and nucleic acid bases as well as nucleosides. An overview of the applications is given together with the microemulsions used for each application.
Recent applications of capillary isoelectric focusing
Authors: Kilár Ferenc
Published: December 2003

After the advent of capillary isoelectric focusing (CIEF) in the 80's several approaches have been developed in order to use the technique in routine analyses. The recent years showed an extensive increase in the applications of this technique employing its exceptionally high‐resolution power. Methodological improvements, as well as hyphenation with other electrophoretic and chromatographic separation procedures, proved the versatility of CIEF in studies of clinically important proteins, recombinant product, cell lysates and other complex mixtures. The combination of CIEF with mass spectrometry detection is one of the major challenges for studying proteomics. This review collected the recent applications of CIEF including innovations in the experimental setup, remedies for the presence of salts in samples, calibration of the pH gradient, carrier ampholyte‐free isoelectric focusing, the progress in micropreparation, two‐dimensional separations, etc.
Recent advances in enantioseparations of peptides by capillary electrophoresis
Authors: Scriba Gerhard K. E.
Published: December 2003

The present review summarizes peptide enantioseparations by capillary electrophoresis with the focus on recent developments. These include the application of new chiral selectors and systematic studies involving series of di‐ and tripeptides with either common features or with a variety of structures. One section emphasizes mechanistic aspects of the migration order of the enantiomers in cyclodextrin‐assisted chiral separations with respect to the complexation constants and the mobilities of the transient diastereomeric complexes. In addition, short paragraphs on the application of chiral capillary electrophoresis to the determination of the stereochemical purity of peptidomimetics and on chiral separations of peptides by capillary electrochromatography have also been included.
Capillary electrophoresis – mass spectrometry: 15 years of developments and applications
Authors: Schmitt‐Kopplin Philippe , Frommberger Moritz
Published: December 2003

Since its introduction in 1987, capillary electrophoresis‐mass spectrometry (CE‐MS) has developed to a well accepted multidimensional analytical approach complementary and/or competitive to classical MS‐hyphenated separation techniques. The threefold combination of rapid developments of an exceptional separation technique, of selective mass detection possibilities, and of very mild ionization modes first allowed these progresses. This article shows the CE specificities that need to be well controlled/known, compared to classical and more routinely used liquid chromatography in the light of its coupling to MS. The major trends and developments over the last 15 years and most of the reviews and applications found in ISI Web of science and publisher databases are presented in a tabulated way. The reader can thus rapidly find existing CE‐MS analysis techniques in his field of research and application (forensics, environment, bioanalytics, pharmaceutics, and metabolites).
Molecularly imprinted polymers in capillary electrochromatography: Recent developments and future trends
Authors: Spégel Peter , Schweitz Leif , Nilsson Staffan
Published: December 2003

The developments in molecularly imprinted polymer (MIP)‐based capillary electrochromatography (CEC) achieved during the past years are reviewed in this article. The MIP is prepared using a templated polymerization reaction and results in a material with a high selectivity towards a predetermined target. The selectivity of the MIP is comparable to that of the biological antibodies, however, the MIP is much more stable and is thus able to withstand extremely harsh conditions in terms of pH, temperature, and organic solvents. The high selectivity and stability of the MIP made it an interesting candidate for application as stationary phase sorbent in chromatography. However, due to slow kinetics the efficiency of the early MIP columns, which were predominantly applied in high‐performance liquid chromatography (HPLC), were limited. The use of CEC was thought to improve the efficiency of the MIP‐based separation system. The small dimensions of the capillary format employed in CEC have put demands on the polymer systems which have resulted in the development of many different polymer formats. Thus, this need for novel MIP formats for applications in CEC has contributed a lot to the general development of MIP formats as well as to the knowledge in MIP synthesis and characteristics.
Recent advances in amino acid analysis by capillary electrophoresis
Authors: Poinsot Véréna , Bayle Christophe , Couderc François
Published: December 2003

Amino acids are studied extensively using capillary electrophoresis. In a previous article, we reviewed applications reported in the period 1999 – early 2001 (Prata, C., Bonnafous, P., Fraysse, N., Treilhou, M., Poinsot, V., Couderc, F., Electrophoresis 2001, 22, 4129–4138). In this article we follow on with this review for the period end of 2001 – beginning of 2003. We will report the developments of detection methods, separations of enantiomers, the new medical applications, and amino acids in food and plants. This review shows that CE is more and more important for the amino acid analysis.
Particles from fires—a screening of common materials found in buildings
Authors: Hertzberg Tommy , Blomqvist Per
Published: December 2003

Small combustion generated particles are known to have a negative impact on human health and on the environment. In spite of the huge amount of particles generated locally in a fire accident, few investigations have been made on the particles from such fires. In this article, 24 different materials or products, typically found in buildings have been exposed to burning conditions in order to examine their particle generating capacity. In addition, a carbon fibre based composite material was tested in order to investigate if asbestos‐resembling particles could be generated in a fire situation.

The majority of the experiments were performed in the small‐scale cone calorimeter, and some further data were collected in intermediate scale (SBI) and full scale (room‐corner) tests. Additional testing of the composite material was made in a small‐scale tubular reactor.

The amount of particles and particle size distributions were measured by the use of a low‐pressure impactor and particle aerodynamic diameter sizes from 30 nm to 10 μm were measured.

The results from the project show that the yield of particles generated varied significantly between materials but that the shape of mass and number size distributions were very similar for all the materials tested. The maximum amount of particles was obtained from materials that did not burn well (e.g. flame retarded materials). Well‐burning materials, e.g. wood materials, tend to oxidize all available substances and thereby minimize the amount of particles in the smoke gas. It was found that asbestos‐resembling particles could be produced from under‐ventilated combustion of the composite material tested. Copyright © 2003 John Wiley & Sons, Ltd.
Flutter instability prediction techniques for bridge deck sections
Authors: Robertson I. , Sherwin S. J. , Bearman P. W.
Published: December 2003

In order to investigate the fluid/structure interaction of a bridge deck in a cross wind, a two‐dimensional hp/Spectral fluid solver has been modified to incorporate a body undergoing translational and rotational motion. A moving frame of reference is attached to the body to utilize the efficiency of a fixed mesh solver. The critical reduced velocity at which a bridge deck undergoes a two degree of freedom flutter instability is then predicted using various methods: a theoretical linear potential model; quasi‐steady theory; a linear evaluation of applied forces using prescribed motion; and free translational and rotational motion of the structure. These predictions are compared with experimental data and the various merits of each scheme are reported. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of calcium ions on the solubility of muscular collagen and tenderness of beef meat
Authors: Ostoja Halina , Cierach Marek
Published: December 2003

The aim of the present study was to determine the effect of aqueous solutions of calcium chloride and calcium lactate on the solubility of beef collagen in raw and cooked meat. The content of total collagen, water‐ and acetic acid‐soluble collagen and insoluble collagen was determined in beef samples. Shearing force was measured after heat treatment. It was found that calcium ions had no significant effect on the solubility of muscular collagen. An improvement in beef tenderness (27%–34%) caused by calcium ions did not result from breaking of the native structure of muscular collagen.
Fluorometric determination of chemically available lysine: Adaptation, validation and application to different milk products
Authors: Ferrer E. , Alegría A. , Farré Rosaura , Abellán P. , Romero F.
Published: December 2003

A spectrophotometric method based on the reaction between available lysine and ortho‐phthaldialdehyde (OPA) was adapted and validated for fluorometric determination of the chemically available lysine contents in milk matrices (UHT and conventional in‐bottle sterilized cow milk, milk‐based infant formulas and infant formula ingredients). The values of the analytical parameters show its usefulness as a routine method (linearity, r = 0.9992; detection limit, 0.0066 mg/mL assay; accuracy, 99–108%; precision, intra‐day 2.1–5.9% and inter‐day 3.5–10.2%). No statistically significant differences (p < 0.05) were found between the values obtained with the adapted method and those obtained applying the 1‐fluoro‐2,4‐dinitrobenzene (FDNB) (Carpenter) technique. The OPA method was used to measure the chemically available lysine contents in UHT and sterilized milk marketed in Spain, to study the evolution of chemically available lysine during the shelf‐life of UHT milks, and finally the quality of name‐ and store‐brand UHT milks was also compared. No statistically significant differences (p < 0.05) were found between either the available lysine contents of the same type of UHT or sterilized milk or between store‐ and name‐brand UHT milks. Statistically significant differences (p < 0.05) were found between the chemically available lysine contents in UHT and sterilized milk. Losses of chemically available lysine ranging from 2.7 to 29% were obtained during the shelf‐life of UHT milk.
Quality of cold‐pressed edible rapeseed oil in Germany
Authors: Matthäus Bertrand , Brühl Ludger
Published: December 2003

Forty‐eight cold‐pressed edible rapeseed oils obtained from small‐ and medium‐sized decentralized plants located all over Germany were characterized by different chemical parameters for their composition and by descriptive sensory evaluation. Between the different oils great differences could be noticed for each parameter. The results evidenced that additionally to the features given in the Guidelines for edible fats and oils of the German Food Codex, especially the sensory evaluation, the oxidation stability (Rancimat), content and the composition of tocopherols, the content of trans‐fatty acids and the content of steradienes were crucial parameters to guarantee a high‐quality product for the consumer.
Changes in phenolic compounds, colour and antioxidant activity in industrial red myrtle liqueurs during storage
Authors: Vacca Vincenzo , Piga Antonio , Del Caro Alessandra , Fenu Paolo A. M. , Agabbio Mario
Published: December 2003

The results of a study on the evolution of phenolic compounds, colour and antioxidant activity in two industrial red myrtle liqueurs during storage in bottles under different bottle headspace (constant or increasing) and exposure to light are reported. In the year of the study, the phenolic compounds showed considerable changes even in the liqueurs stored with constant headspace. The anthocyanins in particular, both free and combined, tended to decrease. As expected, the same phenomena were observed in an accelerated form in the product stored in bottles with increasing headspace. The colour, evaluated according to the classic spectrophotometric parameters of intensity and hue, showed marked variability, especially in samples in which headspace was progressively increased. The two liqueurs showed antioxidant capacity values, expressed as mM of Trolox, comparable to those of red wine. They significantly decreased during storage in the bottles with increasing headspace, while values remained almost constant in the others.
Bayesian analysis of fractionally integrated ARMA with additive noise
Authors: Hsu Nan‐Jung , Breidt F. Jay
Published: December 2003

A new sampling‐based Bayesian approach for fractionally integrated autoregressive moving average (ARFIMA) processes is presented. A particular type of ARMA process is used as an approximation for the ARFIMA in a Metropolis–Hastings algorithm, and then importance sampling is used to adjust for the approximation error. This algorithm is relatively time‐efficient because of fast convergence in the sampling procedures and fewer computations than competitors. Its frequentist properties are investigated through a simulation study. The performance of the posterior means is quite comparable to that of the maximum likelihood estimators for small samples, but the algorithm can be extended easily to a variety of related processes, including ARFIMA plus short‐memory noise. The methodology is illustrated using the Nile River data. Copyright © 2003 John Wiley & Sons, Ltd.
An evaluation of tests of distributional forecasts
Authors: Noceti Pablo , Smith Jeremy , Hodges Stewart
Published: December 2003

One popular method for testing the validity of a model's forecasts is to use the probability integral transforms (pits) of the forecasts and to test for departures from the dual hypotheses of independence and uniformity, with departures from uniformity tested using the Kolmogorov–Smirnov (KS) statistic. This paper investigates the power of five statistics (including the KS statistic) to reject uniformity of the pits in the presence of misspecification in the mean, variance, skewness or kurtosis of the forecast errors. The KS statistic has the lowest power of the five statistics considered and is always dominated by the Anderson and Darling statistic. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of lysophosphatidic acid and sphingosine‐1‐phosphate‐mediated signal transduction in rat cortical oligodendrocytes
Authors: Yu Naichen , Lariosa‐Willingham Karen D. , Lin Fen‐Fen , Webb Michael , Rao Tadimeti S.
Published: December 2003

Lysophosphatidic acid (LPA) and sphingosine‐1‐phosphate (S1P) have been proposed to play a key role in oligodendrocyte maturation and myelinogenesis. In this study, we examined lysophospholipid receptor gene expression in differentiated rat oligodendrocyte cultures and signaling downstream of lysophospholipid receptor activation by LPA and S1P. Differentiated oligodendrocytes express mRNAs encoding lysophospholipid receptors with the relative abundance of lpa1 > s1p5 > s1p1 = s1p2 = lpa3 > s1p3. LPA and S1P transiently increased phosphorylation of extracellular signal‐regulated kinase (ERK) with EC50 values of 956 and 168 nM, respectively. LPA‐ and S1P‐induced ERK phosphorylation was dependent on the activation of mitogen‐activated protein kinase (MAPK), phospholipase C (PLC), and protein kinase C (PKC), but was insensitive to pertussis toxin (PTX). LPA increased intracellular calcium levels in oligodendrocytes and these increases were partially blocked by a PLC inhibitor but not by PTX. In contrast, S1P was not found to induce measurable changes of intracellular calcium. These results taken together suggest that lysophospholipid receptor activation involves receptor coupling to heterotrimeric Gq subunits with consequent activation of PLC, PKC, and MAPK pathways leading to ERK phosphorylation. © 2003 Wiley‐Liss, Inc.
Microglia, a potential source of neurons, astrocytes, and oligodendrocytes
Authors: Yokoyama Akiko , Yang Lihua , Itoh Suzuka , Mori Kohji , Tanaka Junya
Published: December 2003

Microglia are considered the only cell population of mesodermal origin in the brain, although their role is not fully understood. The present study demonstrated that rat primary microglial cells expressed nestin, A2B5, and O4 antigens, which are markers for oligodendrocyte precursor cells. Based on these findings, we investigated whether microglial cells generated neurons or macroglial cells. Purified microglial cells were cultured in the presence of 10% fetal bovine serum for 3 days, followed by culture in the presence of 70% serum for 2 days. During the two‐step culture, microglial cells became highly proliferative and strongly expressed inhibitor of DNA binding (Id) genes, indicative of dedifferentiation of the cells. The dedifferentiated cells also expressed transcription factors that promote differentiation into neurons or macroglial cells. When the dedifferentiated cells were transferred into serum‐free medium on poly‐L‐lysine‐coated substrate, a substantial number of the cells rapidly turned into long process‐bearing cells, which expressed microtubule‐associated protein 2, synapsin I, neurofilament proteins, glial fibrillary acidic protein, or galactocerebroside. When microglial cells were fluorescently labeled through acetylated low‐density lipoprotein (LDL) receptors or by a phagocytosis‐dependent mechanism, fluorescence‐bearing neurons, astrocytes, or oligodendrocytes were observed. Neurospheres, aggregates of neural stem cells, expressed Musashi 1 and epidermal growth factor receptor, but the microglia‐derived cells did not. These results suggest a novel role of microglia as multipotential stem cells to give rise to neurons, astrocytes, or oligodendrocytes. © 2003 Wiley‐Liss, Inc.
Solvatochromic Analysis of Partition Coefficients in the o‐Nitrophenyl Octyl Ether (o‐NPOE)/Water System
Authors: Liu Xiangli , Bouchard Géraldine , Müller Nathalie , Galland Alexandra , Girault Hubert , Testa Bernard , Carrupt Pierre‐Alain
Published: December 2003

The objective of this study was to unravel the structural properties responsible for the partitioning of solutes in o‐nitrophenyl octyl ether (o‐NPOE)/H2O, a new solvent system for the determination of the partition coefficients of ions. A set of 88 compounds (including drugs) was selected to allow a regular and broad distribution of property spaces. Partition coefficients in o‐NPOE/H2O (log Pnpoe) were measured by the shake‐flask or the potentiometric method. Linear solvation free‐energy relationship (LSER) analyses showed that Van der Waals volume, H‐bond‐acceptor basicity, and H‐bond‐donor acidity are the three molecular descriptors of solutes determining their log Pnpoe values. The partitioning mechanism of the investigated compounds in o‐NPOE/H2O is controlled by the same structural properties as it is in 1,2‐dichloroethane (DCE)/H2O. Δlog Poct−npoe Values (difference between log Poct and log Pnpoe) express mainly dipolarity/polarizability and H‐bond‐donor acidity. The solvent o‐NPOE is shown to be a good candidate to replace DCE in measurements of lipophilicity.
Cyclic Peptidomimetics Derived from the Apical Membrane Antigen I of Plasmodium falciparum and Their Use in Malaria Vaccine Design
Authors: Renard Annabelle , Mueller Markus , Zurbriggen Rinaldo , Pluschke Gerd , Robinson John A.
Published: December 2003

A library of 35 cyclic peptidomimetics has been prepared, by a combination of solid‐ and solution‐phase methods, which, together, scan amino acid residues 444–489 in a protruding loop in the subdomain‐III of the apical membrane antigen‐I (AMA‐I), an integral membrane protein found on the surface of Plasmodium falciparum merozoites. The mimetics each contain twelve residues from AMA‐I linked through the N‐ and C‐termini to a β‐hairpin‐inducing template, comprising the dipeptide D‐proline‐L‐Apro (Apro=cis‐4‐amino‐L‐proline). These peptidomimetics were each coupled via the 4‐amino group to a phospholipid, which allows their incorporation into reconstituted influenza virus‐like particles (virosomes) for immunization of mice, as well as their use in ELISA to characterize epitopes recognized by anti‐AMA‐I growth‐inhibitory monoclonal antibodies.
Functionalized and Partially or Differentially Bridged Resorcin[4]arene Cavitands: Synthesis and Solid‐State Structures
Authors: Azov Vladimir A. , Skinner Philip J. , Yamakoshi Yoko , Seiler Paul , Gramlich Volker , Diederich François
Published: December 2003

We report the synthesis and structural characterization of modified Cram‐type, resorcin[4]arene‐based cavitands. Two main loci on the cavitand backbone were selected for structural modification: the upper part (wall domain) and the lower part (legs). Synthesis of unsymmetrically bridged cavitands with different wall components (i.e., 7, 8, and 14–18) was performed by stepwise bridging of the four couples of neighboring, H‐bonded OH‐groups of octol 1a (Schemes 1, 2, 4, and 5). Cavitands with modified legs (i.e., 20, 24, 27, and 28), targeted for surface immobilization, were synthesized by short routes starting from suitable aldehyde starting materials incorporating either the fully preformed leg moieties or functional precursors to the final legs (Schemes 7–10). The new cavitand substitution patterns described in this paper should enable the construction of a wide variety of functional architectures in the future. X‐Ray crystallography afforded the characterization of cavitands 2c (Fig. 3) and 24 (Fig. 7) in the vase conformation, with 2c featuring a well‐ordered CH2Cl2 guest molecule in its cavity. A particular highlight is the X‐ray crystal‐structure determination of octanitro derivative 19 (Scheme 6), which, for the first time, shows a cavitand, lacking substituents in the ortho‐position to the two O‐atoms of the four resorcinol moieties, in the kite‐conformation (Fig. 5).
Oligodeoxynucleotide Duplexes Containing (5′S)‐5′‐C‐Alkyl‐Modified 2′‐Deoxynucleosides: Can an Alkyl Zipper across the DNA Minor‐Groove Enhance Duplex Stability?
Authors: Trafelet Huldreich , Parel Serge P. , Leumann Christian J.
Published: December 2003

A series of oligonucleotides containing (5′S)‐5′‐C‐butyl‐ and (5′S)‐5′‐C‐isopentyl‐substituted 2′‐deoxyribonucleosides were designed, prepared, and characterized with the intention to explore alkyl‐zipper formation between opposing alkyl chains across the minor groove of oligonucleotide duplexes as a means to modulate DNA‐duplex stability. From four possible arrangements of the alkyl groups that differ in the density of packing of the alkyl chains across the minor groove, three (duplex types I–III, Fig. 2) could experimentally be realized and their duplex‐forming properties analyzed by UV‐melting curves, CD spectroscopy, and isothermal titration calorimetry (ITC), as well as by molecular modeling. The results show that all arrangements of alkyl residues within the minor groove of DNA are thermally destabilizing by 1.5–3°/modification in Tm. We found that, within the proposed duplexes with more loosely packed alkyl groups (type‐III duplexes), accommodation of alkyl residues without extended distorsion of the helical parameters of B‐DNA is possible but does not lead to higher thermodynamic stability. The more densely packed and more unevenly distributed arrangement (type‐II duplexes) seems to suffer from ecliptic positioning of opposite alkyl groups, which might account for a systematic negative contribution to stability due to steric interactions. The decreased stability in the type‐III duplexes described here may be due either to missing hydrophobic interactions of the alkyl groups (not bulky enough to make close contacts), or to an overcompensation of favorable alkyl‐zipper formation presumably by loss of structured H2O in the minor groove.
The Use of Butane Diacetals of Glycolic Acid as Precursors for the Synthesis of the Phytotoxic Calmodulin Inhibitor Herbarumin II
Authors: Díez Elena , Dixon Darren J. , Ley Steven V. , Polara Alessandra , Rodríguez Felix
Published: December 2003

The total synthesis of phytotoxic nonenolide herbarumin II (1) has been achieved by implementation of butane diacetal (BDA)‐desymmetrised glycolate building blocks. Three of the four stereogenic centres present in the key coupling fragments were generated from both enantiomeric forms of the BDA building block in highly diastereoselective alkylation and aldol reactions.
Suicide Inactivation of Dioldehydrase by 2‐Chloroacetaldehyde: Formation of the ‘cis‐Ethanesemidione’ Radical, and the Role of a Monovalent Cation
Authors: Schwartz Phillip , LoBrutto Russell , Reed George H. , Frey Perry A.
Published: December 2003

Dioldehydrase is an adenosylcobalamin‐dependent enzyme that catalyzes the dehydration of (R)‐ or (S)‐propane‐1,2‐diol to propanal. The reaction proceeds by a radical mechanism initiated by the homolytic scission of the covalent CoC(5′) bond in the coenzyme to form cob(II)alamin and the 5‐deoxyadenosyl radical as transient intermediates. Dioldehydrase is subject to ‘suicide inactivation’ by substrate/product analogs. Inactivation by 2‐chloroacetaldehyde converts the inactivator into the ‘cis‐ethanesemidione’ radical. A mechanism for this process includes reaction of chloroacetaldehyde in the reverse of the normal catalytic process to a rearranged radical that eliminates HCl. K+ and other monovalent cations of similar size, including Tl+, are required for dioldehydrase activity and for suicide inactivation by glycolaldehyde or 2‐chloroacetaldehyde. A K+ ion is bound to propane‐1,2‐diol in dioldehydrase. Both EPR and pulsed‐EPR experiments show that the magnetic nuclei of thallous ions (203Tl+, 205Tl+) do not interact with the unpaired electron in the cis‐ethanesemidione radical at the active site of dioldehydrase. Pulsed‐EPR experiments implicate a 14NH group, possibly of His143, interacting with the radical at the active site.
Isoquinuclidine Mimics of β‐D‐Glucopyranosides: Differences and Similarities in the Mechanism of Action of some β‐D‐Glucosidases and a β‐D‐Mannosidase
Authors: Böhm Matthias , Lorthiois Edwige , Meyyappan Muthuppalaniappan , Vasella Andrea
Published: December 2003

The D‐gluco‐isoquinuclidines 3 and 4 were prepared and tested as inhibitors of the β‐glucosidases from Caldocellum saccharolyticum and from sweet almonds; the results are compared to the inhibition of snail β‐mannosidase by the D‐manno‐isoquinuclidines 1 and 2. Exploratory experiments in the racemic series showed that treatment of the ester epoxide 6 with benzyl alcoholates leads only to epimerisation, transesterification, and formation of the cyclopropane 9. Ring opening of the reduced epoxide 13 by NaN3 proceeded regioselectively to provide 14. Treatment of the C(6)O‐triflate 16 with AcOCs induced a rearrangement; the reaction with NaN3 gave the C(5)‐azido derivative 14. The acetoxy triflate 18, however, reacted with AcOCs to provide the desired gluco‐isoquinuclidine 19. Similarly, the enantiomerically pure acetoxy triflate 22 provided the D‐gluco‐isoquinuclidine 24, which was reduced and deprotected to provide 3 and 4. The deoxy analogues 30 and 31 were obtained by reductive deiodination of the iodide 27, derived from 22. The D‐gluco‐isoquinuclidines 3, 4, 30, and 31 are much weaker inhibitors of β‐glucosidases than the D‐manno‐analogues 1 and 2 of snail β‐mannosidase. The N‐benzyl derivative 3 is a weaker inhibitor than the N‐unsubstituted analogue in the gluco‐series, while it is a much stronger inhibitor in the manno‐series. A consideration of the pKHA values of the isoquinuclidines 1–4 and the pH value of the enzyme assays suggests that the D‐gluco‐isoquinuclidines are poor mimics of the shape of a reactive, enzyme‐bound gluco‐conformer, while the D‐manno‐analogues are reasonably good mimics of a reactive, enzyme‐bound manno‐conformer. The inhibition results may also suggest that the glycosidase induced lengthening of the scissile bond and rehybridisation of the anomeric centre are more strongly correlated with the change of the ground‐state conformation during hydrolysis of β‐D‐glucopyranosides than of β‐D‐mannopyranosides.
Supervisory coaching behavior, employee satisfaction, and warehouse employee performance: A dyadic perspective in the distribution industry
Authors: Ellinger Andrea D. , Ellinger Alexander E. , Keller Scott B.
Published: December 2003

Coaching has received considerable attention in recent years as the responsibility for employees' learning
and development has been increasingly devolved to line managers. Yet there exists little published empirical
research that measures specific coaching behaviors of line managers or examines the linkages between line
managers' coaching behavior and employee performance. This survey study integrates the perceptions of
supervisors and their respective employees to examine supervisory coaching behavior in an industrial context and to
assess its association with employee job satisfaction and performance. Findings suggest that supervisory coaching
behavior is positively associated with employees' job satisfaction and performance. Implications for research
and practice are presented.
Effects of maternal inattentiveness on infant social referencing
Authors: Stenberg Gunilla
Published: December 2003

The aim of the study was to clarify the meaning of infant looking behaviour when the infant is confronted with an ambiguous situation in order to disentangle the two processes social referencing and attachment. Ninety‐six 12‐month‐olds, presented with an ambiguous or an unambiguous toy, were assigned to one of four conditions; mother inattentive, mother conveyed positive information, and mother conveyed negative information about the ambiguous toy. In the fourth condition (control condition), an unambiguous toy was presented (mother inattentive). The ambiguous situation elicited more referencing looks than the unambiguous situation. During the presentation of the ambiguous toy, infants with inattentive mothers referenced the experimenter more than infants whose mothers provided guidance. In the following free‐play situation, infants in the inattentive group referenced mother to a higher degree than did the other infants. They played less with the toy than infants who had received positive information and infants in the control group, and were less eager to explore the surroundings than infants in the other three groups. When mother turned attentive the infants ceased referencing her and showed an interest in exploring. Copyright © 2003 John Wiley & Sons, Ltd.
The influence of family environment and child temperament on work/family role strain for mothers and fathers
Authors: Lee Marceline , Vernon‐Feagans Lynne , Vazquez Arcel , Kolak Amy
Published: December 2003

This study examined the additive effect of structural variables, child characteristics, and the family environment on mothers' and fathers' work/family role strain. Differences between mothers and fathers on these variables were also examined. The sample consisted of 36 dualearner families whose children had been in daycare from infancy through 4 years of age. Structural variables included work schedules and time spent with child for mothers only, fathers only, and both parents together with child. Child characteristics included temperament and health. Family environment variables included different components of the family environment (conflict, cohesion, expressiveness, organization, and control) and parenting daily hassles. Results showed that mothers' time with child and caregiving for child were greater than fathers'. Mothers reported more expressiveness in the family and more daily hassles with children than fathers. Mothers' level of role strain was also significantly higher than fathers'. For mothers, role strain was associated with hours away from home, child sociability, family conflict, and daily hassles resulting in an R2 of 0.57. Fathers' role strain was associated with family expressiveness, organization, and their wives' daily hassles resulting in an R2 of 0.37. Data suggest that mothers' and fathers' role strain may be driven by somewhat different factors. For women, aspects of the family and the child and work hours accounted for a considerable portion of the variance while for men, only aspects of the family environment were associated with their level of role strain. Copyright © 2003 John Wiley & Sons, Ltd.
A new statutory director’s duty for Australia — a ‘duty’ to be concerned about employee entitlements in the insolvent corporation
Authors: Symes Christopher F.
Published: December 2003

Australia has introduced legislation that is aimed at preventing a person from entering into agreements or conducting transactions with the intention of defeating the recovery of employee entitlements. It is essentially aimed at directors and their behaviour in the pre‐appointment period. This paper discusses the history leading up to such a legislative move and the likely benign impact now that the Corporations Act in Australia prohibits such behaviour. Further, the paper argues that mooted changes to the legislation giving employees a ‘maximum priority’ ahead of secured creditors is unnecessary. Copyright © 2003 John Wiley & Sons, Ltd.
International labour migration and quality of life: findings from rural Thailand
Authors: Jones Huw , Kittisuksathit Sirinan
Published: December 2003

This paper provides one of the few detailed case studies of the costs and benefits of international labour migration within the East Asian labour‐market system that developed rapidly in the 1990s. Analysis focuses on communities of migrant‐worker origin in Northeastern Thailand. The paper considers quality of life dimensions for households distinguished on the basis of differing participation in international labour migration. Although the highest quality of life, based on locally identified indicators, is found in households containing returned international migrant workers, the differences between the analytical groups are fairly subdued. The implication is that international migration experience has been so widespread in these communities that it has had a ‘demonstration and emulation’ effect on aspirations and achievement throughout the whole of these communities. Copyright © 2003 John Wiley & Sons, Ltd.
The floating population's household strategies and the role of migration in China's regional development and integration
Authors: Zhu Yu
Published: December 2003

This paper examines the floating population, one of the most important products of China's reform and open‐door policies since the 1980s, from the perspectives of household strategies in migration, regional development and regional integration. Based on various data sources, including government statistics, questionnaire surveys, literature research and case studies, the paper suggests that the emergence and development of the floating population has been one response to widening regional gaps, one of the major issues arising from China's recent development. One cause of this common, non‐permanent form of migration is China's household registration system, but the household strategies of migrants must also be recognised as an important element underpinning this process. Further analysis shows that the attraction of the prosperous areas to the floating population has been closely related to the involvement of China's coastal areas in the process of globalisation. One special group of migrants and their descendants, that is the Chinese overseas and Chinese in Hong Kong, Macao and Taiwan, have played important roles in this process and have contributed greatly to the prosperity of the coastal areas. It is argued that the new generation of migrants, the floating population who have also played an important role in the prosperity of the coastal areas, may also be instrumental in the development of their hometowns, helping to reduce the problem of regional disparity in China. Thus an important implication of this study is that although migrants often move because of unbalanced regional development, eventually they could be a driving force for regional integration; this should be given more attention in both academic research and policy making. Copyright © 2003 John Wiley & Sons, Ltd.
The effect of phosphorylcholine‐coated materials on the inflammatory response and fibrous capsule formation: In vitro and in vivo observations
Authors: Goreish Hind H. , Lewis Andrew L. , Rose Susanna , Lloyd Andrew W.
Published: December 2003

Several experiments were performed to compare the in vitro adhesion of human macrophage and granulocyte inflammatory cells to polyethylene terephthalate substrate and the same coated with a phosphorylcholine (PC)‐based polymer. The inclusion of various types of serum at different stages in the assay indicated that protein adsorption and passivation of the surface may be responsible for reducing the number of inflammatory cells adhering to the uncoated polyethylene terephthalate controls. In all of the assays performed there was a statistically significant reduction (p < 0.05; analysis of variance) of the number of inflammatory cells adhering to the PC‐coated samples, linked to the ability of these surfaces to resist protein adhesion. Implantations of PC‐coated stainless steel and high‐density polyethylene USP control samples were made in a rabbit intramuscular model. Histological examination of the number of inflammatory cells present around the implant sites 4 weeks postimplantation showed there were 40% less cells associated with the PC‐coated samples compared with control, but this was not statistically significant. Fibrous capsule thickness, however, whereas marginally less at 4 weeks, had almost completely regressed for the PC‐coated sample at 13 weeks postimplantation and was statistically thinner (p < 0.01; Mann‐Whitney U test) than the high‐density polyethylene USP control. These findings support the view that low biointeractions observed for PC‐based technology in vitro can result in reduced inflammation and foreign body reaction in vivo. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 1–9, 2004