bluuebunny/crossref_metadata_2025 huggingface dataset:
Birth and death of cells in limb development: A mapping study
Authors: Fernández‐Terán M.A. , Hinchliffe J.R. , Ros M.A.
Published: August 2006

Cell death and cell proliferation are basic cellular processes that need to be precisely controlled during embryonic development. The developing vertebrate limb illustrates particularly well how correct morphogenesis depends on the appropriate spatial and temporal balance between cell death and cell proliferation. Precise knowledge of the patterns of cell proliferation and cell death during limb development is required to understand how their modifications may contribute to the generation of the great diversity of limb phenotypes that result from spontaneous mutations or induced genetic manipulations. We have performed a comprehensive analysis of the patterns of cell death, assayed by terminal deoxynucleotidyl transferase–mediated deoxyuridinetriphosphate nick end‐labeling (TUNEL), and cell proliferation, assayed by anti‐phosphorylated histone H3 immunohistochemistry, in consecutive sections of forelimbs and hindlimbs covering an extensive period of chick and mouse limb development. Our results confirm and expand previous reports and show common and specific areas of cell death for each species. Mitotic cells were found scattered in a uniform distribution across the early limb bud, with the exception of the areas of cell death in which mitotic cells were scarce. At later stages, mitotic cells were seen more abundantly in the digital tips. The aim of the present study was to satisfy the need for organized data sets describing these processes, which will allow the side‐by‐side comparison between the two major model organisms of limb development, i.e., the mouse and the chick. Developmental Dynamics 235:2521–2537, 2006. © 2006 Wiley‐Liss, Inc.
Silica Supported Submicron SiO2@Y2SiO5:Eu3+ and SiO2@Y2SiO5:Ce3+/Tb3+ Spherical Particles with a Core–Shell Structure: Sol–Gel Synthesis and Characterization
Authors: Lin Cuikun , Wang Huan , Kong Deyan , Yu Min , Liu Xiaoming , Wang Zhenling , Lin Jun
Published: August 2006

X1‐Y2SiO5:Eu3+ and X1‐Y2SiO5:Ce3+ and/or Tb3+ phosphor layers have been coated on nonaggregated, monodisperse, submicron spherical SiO2 particles by a sol–gel process, followed by surface reaction at high temperature (1000 °C), to give core/shell structured SiO2@Y2SiO5:Eu3+ and SiO2@Y2SiO5:Ce3+/Tb3+ particles. X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), TEM, photoluminescence (PL), low voltage cathodoluminescence (CL), and time‐resolved PL spectra and lifetimes are used to characterize these materials. The XRD results indicate that X1‐Y2SiO5 layers have been successfully coated on the surface of SiO2 particles, as further verified by the FESEM and TEM images. The PL and CL studies suggest that SiO2@Y2SiO5:Eu3+, SiO2@Y2SiO5:Tb3+ (or Ce3+/Tb3+), and SiO2@Y2SiO5:Ce3+ core/shell particles exhibit red (Eu3+, 613 nm: 5D0–7F2), green (Tb3+, 542 nm: 5D4–7F5), or blue (Ce3+, 450 nm: 5d‐4f) luminescence, respectively. PL excitation, emission, and time‐resolved spectra demonstrate that there is an energy transfer from Ce3+ to Tb3+ in the SiO2@Y2SiO5:Ce3+,Tb3+ core/shell particles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Regioselective 5‐, 4‐, and 2‐Substitution of (S)‐6‐Chloronicotine and 4‐Substitution of (S)‐5‐Chloronicotine
Authors: Wagner Florence F. , Comins Daniel L.
Published: August 2006

A variety of novel 2‐, 4‐, and 5‐substituted 6‐chloronicotine and 4‐substituted 5‐chloronicotine derivatives have been synthesized in a regioselective manner in moderate to high yield from (S)‐6‐chloronicotine and (S)‐5‐chloronicotine, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Flame‐retardant finishing of cotton fleece fabric: part I. The use of a hydroxy‐functional organophosphorus oligomer and dimethyloldihydroxylethyleneurea
Authors: Yang Charles Q. , Qiu Xiaoqun
Published: August 2006

Cotton fleece has become a popular fashion in recent years. However, most of the 100% cotton fleece fabric is not able to meet the federal flammability standard (‘16 CFR Part 1610: Standard for the Flammability of Clothing Textiles’) without chemical treatment. In this research, we investigated the use of the combination of a hydroxy‐functional organophosphorus oligomer (HFPO) as the flame‐retarding agent and dimethyloldihydroxylethyleneurea (DMDHEU) as the binder to reduce the flammability of cotton fleece. We found that HFPO is effective in reducing the flammability of the cotton fleece whereas DMDHEU enhances the effectiveness of HFPO due to phosphorus–nitrogen synergism. The flammability as well as other properties of the treated cotton fleece is affected by both the concentration of HFPO and that of DMDHEU. The cotton fleece treated with HFPO/DMDHEU passes the federal flammability standard and shows high strength retention with little change in fabric whiteness and hand. We also found that the flame‐retardant finishing system is durable to multiple home launderings. The combination of HFPO and DMDHEU has the potential to become a practical flame‐retardant finishing system to reduce the flammability of cotton fleeces. Copyright © 2006 John Wiley & Sons, Ltd.
Pittosporum undulatum Vent. grown in Portugal: secretory structures, seasonal variation and enantiomeric composition of its essential oil
Authors: Ferreira Nicolau J. , Meireles de Sousa Inês G. , Luís Tiago Cunha , Currais António José M. , Figueiredo Ana Cristina , Costa Monya M. , Lima A. Sofia B. , Santos Pedro A. G. , Barroso José G. , Pedro Luis G. , Scheffer Johannes J. C.
Published: August 2006

Aerial parts of Pittosporum undulatum were collected fortnightly for 1 year at the Parque de Saúde de Lisboa. Collective samples of two populations were investigated, i.e. from pruned and non‐pruned trees, and in addition samples from one pruned and one non‐pruned individual. An SEM study of the aerial parts showed the presence of non‐glandular T‐shaped trichomes, and capitate trichomes with an elongated stalk and two to four round‐shaped cells on the top. Numerous canals were seen at the level of the capsule wall as well as in the leaves and stems. Essential oil samples were isolated from the (deep‐frozen) aerial parts by hydrodistillation to estimate the oil yields, and by distillation–extraction to determine their percentage composition, and analysed by GC and GC–MS. Monoterpenes (59–97%) were dominant in all oils, sabinene (5–58%), limonene (2–37%) and terpinen‐4‐ol (4–27%) being the major components, although in different relative amounts during the year of collection. Benzyl benzoate (8%) and benzyl salicylate (10%) attained high relative amounts in the oils from fully developed flowers, whereas in the oils from the other plant parts their relative amounts did not exceed 1%. The enantiomeric ratio of sabinene, limonene and terpinen‐4‐ol was investigated in the leaf, flower and capsule oils, showing dominance of the (+)‐forms and homogeneity between all the oil samples. Copyright © 2006 John Wiley & Sons, Ltd.
Altered promoter usage characterizes monoallelic transcription arising with ERBB2 amplification in human breast cancers
Authors: Benz Christopher C. , Fedele Vita , Xu Fan , Ylstra Bauke , Ginzinger David , Yu Mamie , Moore Dan , Hall Rayna Kneuper , Wolff Daynna J. , Disis Mary L. , Eppenberger‐Castori Serenella , Eppenberger Urs , Schittulli Francesco , Tommasi Stefania , Paradiso Angelo , Scott Gary K. , Albertson Donna G.
Published: August 2006

Analysis of a collection of human breast cancers (n = 150), enriched in ERBB2‐positive cases (n = 57) and involving tumor genotyping relative to population‐matched blood genotyping (n = 749) for a common ERBB2 single nucleotide polymorphism Ala(G)1170Pro(C), revealed that ERBB2 amplification in breast cancer is invariably monoallelic. Analysis of paired breast cancer and blood samples from informative (G1170C heterozygotic) ERBB2‐positive (n = 12) and ERBB2‐negative (n = 17) cases not only confirmed monoallelic amplification and ERBB2 transcriptional overexpression but also revealed that most low ERBB2 expressing breast cancers (12/17) exhibit unbalanced allelic transcription, showing 3‐fold to nearly 5,000‐fold preferential expression from one of two inherited alleles. To explore cis‐acting transcriptional mechanisms potentially selected during ERBB2 amplification, levels of four different ERBB2 transcript variants (5.2, 4.7, 2.1, and 1.4 kb) were correlated with total (4.6 kb) ERBB2 mRNA levels in ERBB2‐positive (n = 14) versus ERBB2‐negative (n = 43) primary breast cancers. Relative expression of only the 2.1 kb extracellular domain‐encoding splice variant and a 4.7 kb mRNA variant that uses an alternative start site were significantly increased in association with ERBB2‐positivity, implicating altered promoter usage and selective transcript regulation within the ERBB2 amplicon. Altogether, these findings provide new mechanistic insights into the development of ERBB2‐positive breast cancer and strong rationale for delineating candidate cis‐acting regulatory elements that may link allele‐specific ERBB2 transcription in premalignant breast epithelia with subsequent development of breast cancers bearing monoallelic ERBB2 amplicons. © 2006 Wiley‐Liss, Inc.
Evolution of declarative memory
Authors: Manns Joseph R. , Eichenbaum Howard
Published: August 2006

The present review considers research on the hippocampus and related areas from humans and experimental animals and makes three main points. First, many of the anatomical details of the hippocampus and adjacent cortical areas in the parahippocampal region are conserved across mammals. Second, the functional role of these areas in declarative memory is also conserved across species. Third, an evolutionary approach will be key to understanding exactly how the local circuitry of the hippocampus and parahippocampal region supports declarative memory. To highlight the utility of this approach, a schematic model is described in which separate streams of spatial and nonspatial information converge on the hippocampus. By this view, a fundamental function of the mammalian hippocampus is to combine incoming information about spatial context from the postrhinal (parahippocampal in primates) cortex and medial entorhinal area with incoming information about nonspatial items from the perirhinal cortex and lateral entorhinal area. The underlying neurobiological computations that arise from local circuitry enable item‐in‐context memory and are proposed to be fundamental to many examples of declarative memory, including episodic memory in humans and spatial memory in experimental animals. © 2006 Wiley‐Liss, Inc.
Raf‐1 signaling is required for the later stages of 1,25‐dihydroxyvitamin D3‐induced differentiation of HL60 cells but is not mediated by the MEK/ERK module
Authors: Wang Xuening , Studzinski George P.
Published: August 2006

We are interested in determining the signaling pathways for 1,25‐dihydroxyvitamin D3 (1,25D)‐induced differentiation of HL60 leukemic cells. One possible candidate is Raf‐1, which is known to signal cell proliferation and neoplastic transformation through MEK, ERK, and downstream targets. It can also participate in the regulation of cell survival and various forms of cell differentiation, though the precise pathways are less well delineated. Here we report that Raf‐1 has a role in monocytic differentiation of human myeloid leukemia HL60, which is not mediated by MEK and ERK, but likely by direct interaction with p90RSK. Specifically, we show that Raf‐1 and p90RSK are increasingly activated in the later stages of differentiation of HL60 cells, at the same time as activation of MEK and ERK is decreasing. Transfection of a wild‐type Raf‐1 construct enhances 1,25D‐induced differentiation, while antisense Raf‐1 or short interfering (si) Raf‐1 reduces 1,25D‐induced differentiation. In contrast, antisense oligodeoxynucleotides (ODN) and siRNAs to MEK or ERK have no detectable effect on differentiation. In late stage differentiating cells Raf‐1 and p90RSK are found as a complex, and inhibition of Raf‐1, but not MEK or ERK expression reduces the levels of phosphorylated p90 RSK. These findings support the thesis that Raf‐1 signals cell proliferation and cell differentiation through different intermediary proteins. J. Cell. Physiol. 209: 253–260, 2006. © 2006 Wiley‐Liss, Inc.
Functional characterization of PKDREJ, a male germ cell‐restricted polycystin
Authors: Sutton Keith A. , Jungnickel Melissa K. , Ward Christopher J. , Harris Peter C. , Florman Harvey M.
Published: August 2006

Polycystin‐1 regulates a number of cellular processes through the formation of complexes with the polycystin‐2 ion channel or with other signal transduction proteins. Polycystin‐1 is expressed in many tissues but other members of this gene family are distributed in a more restricted fashion. PKDREJ expression has been detected only in the mammalian testis, where it is restricted to the spermatogenic lineage and retained in mature sperm. However, the functional characteristics of this protein and its role in sperm biology are not well understood. In this study it is shown that PKDREJ can modulate G protein signaling and associates with several members of the polycystin‐2 family. These interactions, as well as polycystin‐2 association with TRPC channels, are consistent with a role of this protein in the regulation of the acrosome reaction and in other aspects of sperm physiology. J. Cell. Physiol. 209: 493–500, 2006. © 2006 Wiley‐Liss, Inc.
Discrimination of teas based on total luminescence spectroscopy and pattern recognition
Authors: Nitin Seetohul L , Islam Meez , O'Hare William T , Ali Zulfiqur
Published: August 2006

This paper reports on the application of total luminescence spectroscopy to discriminate between seven different types of tea: four bottled liquid Japanese teas (oolong, green, houji and black teas) and three leaf teas (Kenya, Assam and Ceylon teas). Total luminescence spectra were recorded by measuring the emission spectra in the range 300–700 nm at excitation wavelengths from 250 to 590 nm. Discrimination of teas based on their spectral data was performed by principal component analysis, a common chemometric method used for data reduction and visualisation. The results demonstrate the ability of fluorescence techniques to differentiate between green tea (unfermented), black tea (fermented) and oolong tea (partially fermented). Copyright © 2006 Society of Chemical Industry
Novel Michael Addition Networks Containing Poly(propylene glycol) Telechelic Oligomers
Authors: Mather Brian D. , Miller Kevin M. , Long Timothy E.
Published: August 2006

Summary: Poly(propylene glycol) oligomers with molecular weights ranging from 1 000 to 8 000 g · mol−1 were end‐functionalized with acetoacetate groups and subsequently crosslinked using carbon‐Michael addition with PEG diacrylate. Gel fraction analysis, DMA, TGA, tensile, and swelling measurements were utilized to characterize the networks. The thermomechanical properties of the networks were analyzed with respect to the molecular weight between crosslink points (Mc) and the critical molecular weight for entanglement (Me). Sampling experiments during crosslinking revealed the evolution of molecular weight with time and monomer conversion. Kinetic analyses of the Michael additions were performed using 1H NMR spectroscopy, and the influence of basic catalyst and concentration was elucidated.

Synthesis of acetoacetate networks from acetoacetate‐functionalized PPG using DBU as a basic catalyst.

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Synthesis of acetoacetate networks from acetoacetate‐functionalized PPG using DBU as a basic catalyst.
Chemical Structures Formed in Electron Beam Irradiated Poly(tetrafluoroethylene‐co‐hexafluoropropylene) (FEP)
Authors: Lappan Uwe , Geißler Uwe , Scheler Ulrich
Published: August 2006

Summary: The perfluorinated copolymer poly(tetrafluoroethylene‐co‐hexafluoropropylene) (FEP) was electron beam irradiated under vacuum at various temperatures ranging from room temperature to a temperature above the melting temperature of FEP. Changes of the chemical structure were analyzed by 19F solid‐state NMR and IR spectroscopy. Trifluoromethyl end groups were generated as a result of main chain scission at all irradiation temperatures studied. In addition, trifluoromethyl side groups in various environments and double bond structures were formed. Quantitative analysis showed that long‐chain branches were formed at irradiation temperatures above 200 °C. Furthermore, the hexafluoropropylene (HFP) units in FEP were found to be less sensitive to radiation than the perfluoropropyl vinyl ether (PPVE) units in poly[tetrafluoroethylene‐co‐(perfluoropropyl vinyl ether)] (PFA).

19F solid‐state NMR spectra of FEP.

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19F solid‐state NMR spectra of FEP.
Cover Picture: Macromol. Mater. Eng. 8/2006
Authors: Wu You‐Ping , Zhao Wei , Zhang Li‐Qun
Published: August 2006

Cover: The picture on the cover shows the flex fatigue life of carbon black filled SBR with 0–5 phr nanodispersed clay and ESEM images of flexing fracture surfaces of carbon black filled SBR without clay or with 5 phr clay. Addition of clay greatly improves the flex fatigue life of composites due to the increased hysteresis and tear energy leading to the advantage of clay with high aspect ratio in blunting crack over carbon black. Further details can be found in the article by Y.‐P. Wu, W. Zhao, and L.‐Q. Zhang* on page 944.
Exercise‐induced cramp, myoglobinuria, and tubular aggregates in phosphoglycerate mutase deficiency
Authors: Oh Shin J. , Park Kyung‐Seok , Ryan Hewitt F. , Danon Moris J. , Lu Jiesheng , Naini Ali B. , DiMauro Salvatore
Published: August 2006

We report two patients in whom phosphoglycerate mutase (PGAM) deficiency was associated with the triad of exercise‐induced cramps, recurrent myoglobinuria, and tubular aggregates in the muscle biopsy. Serum creatine kinase (CK) levels were elevated between attacks of myoglobinuria. Forearm ischemic exercise tests produced subnormal increases of venous lactate. Muscle biopsies showed subsarcolemmal tubular aggregates in type 2 fibers. Muscle PGAM activities were markedly decreased (3% of the normal mean) and molecular genetic studies showed that both patients were homozygous for a described missense mutation (W78X). A review of 15 cases with tubular aggregates in the muscle biopsies from our laboratory and 15 cases with PGAM deficiency described in the literature showed that this clinicopathological triad is highly suggestive of PGAM deficiency. Muscle Nerve, 2006
Estimation of average backorders for an assemble‐to‐order system with random batch demands through extreme statistics
Authors: Lu Yingdong
Published: August 2006

We investigate inventory management for a large‐scale multi‐product, multi‐component Assemble‐to‐Order system with general random batch demands. Results from extreme statistics theory are applied in developing approximation schemes for a widely used performance measure, customer backorders. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007
An enhanced multi‐scale approach for masonry wall computations with localization of damage
Authors: Massart T. J. , Peerlings R. H. J. , Geers M. G. D.
Published: August 2006

This contribution presents a multi‐scale framework for the computational study of masonry structures. In order to overcome the need for excessively complex closed‐form constitutive equations, a first‐order computational homogenization framework is applied to infer the non‐linear material behaviour of brick masonry in the presence of quasi‐brittle damage. A localization analysis is carried out based on the macroscopic homogenized tangent stiffness. It is shown that localization is detected along preferential orientations, which are consistent with the underlying mesostructural failure patterns and with the applied loading. The macroscopic description is enhanced with a finite width damage band model in order to allow the treatment of macroscopic localization resulting from damage growth in the constituents. As a result of the use of homogenization techniques on finite volumes and the presence of quasi‐brittle constituents, mesostructural snap‐back may occur in the homogenized material response. A methodology to introduce this type of response in the multi‐scale technique is proposed. The numerical implementation of the multi‐scale solution scheme using a finite element method is outlined. The results obtained by the framework are illustrated by means of elementary examples, and by an example of a structural wall computation. Copyright © 2006 John Wiley & Sons, Ltd.
A boundary cohesive grain element formulation for modelling intergranular microfracture in polycrystalline brittle materials
Authors: Sfantos G. K. , Aliabadi M. H.
Published: August 2006

In this paper, a cohesive grain boundary integral formulation is proposed, for simulating intergranular microfracture evolution in polycrystalline brittle materials. Artificially generated polycrystalline microstructures are discretized using the proposed anisotropic boundary element method, considering the random location, morphology and material orientation of each grain. Each grain is assumed as a single crystal with general elastic orthotropic mechanical behaviour. Crack initiation and propagation along the grain boundaries interfaces are modelled using a linear cohesive law, considering mixed mode failure conditions. Furthermore, a non‐linear frictional contact analysis is performed over cracked grain interfaces to encounter cases where crack surfaces come into contact, slide or separate. The effect of randomly located pre‐existing flaws on the overall behaviour and microcracking evolution of a polycrystalline material is also investigated for different Weibull moduli. The stochastic effects of each grain morphology‐orientation, internal friction and randomly distributed pre‐existing flaws, under different loading conditions, are studied probabilistically by simulating various randomly generated microstructures. Copyright © 2006 John Wiley & Sons, Ltd.
FEM and BEM coupling in elastostatics using localized Lagrange multipliers
Authors: González José A. , Park K. C. , Felippa Carlos A.
Published: August 2006

The equations produced by the finite and boundary element methods in structural mechanics are expressed in different variables and cannot be linked without modifications. Conventional coupling methods of these numerical techniques have traditionally been based on the use of classical Lagrange multipliers making a direct connection of the two solids through their common interfaces using matching meshes and altering the formulation of one of the methods to make it compatible with the other. In this work, a discrete surface called frame is interposed between the connected subdomains to approximate their common interface displacements, it is treated using a finite element discretization and connected to each substructure using localized Lagrange multipliers collocated at the interface nodes. This methodology facilitates the connection of non‐matching finite and boundary element meshes avoiding modifications to the numerical methods used and providing a partitioned formulation, which preserves software modularity. Copyright © 2006 John Wiley & Sons, Ltd.
Corporate political action in China and America: a comparative perspective
Authors: Gao Yongqiang
Published: August 2006

Corporate political action (CPA) is always an interesting topic for management scholars since 1980s. There are a large plenty of literatures from different disciplines focus on this topic. But till now, studies on this topic are almost conducted under the Western culture and taking the Western countries as objective, very few studies are conducted in non‐Western countries, and specifically, the CPA in China is nearly untouched. Due to the differences of culture and political economy between China and the West, CPA in China may be very different from the West's. This article discusses the similarities and differences of CPA in China and America. The result shows that due to the differences in culture and political economical system between China and America, CPA in China is very different from America. This study will help to understand the CPA in China for outsiders, especially for Americans. It also helps multinational enterprises (MNEs) in China to take suitable political actions to support their interests.

Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and properties of novel biodegradable poly(ε‐caprolactone)/ poly(ethylene glycol)‐based polyurethane elastomers
Authors: Yeganeh Hamid , Jamshidi Hajar , Jamshidi Sadegh
Published: August 2006

Elastomeric polyurethanes with tunable biodegradation properties and suitable for numerous biomedical applications were synthesized via reaction of epoxy‐terminated polyurethanes (EUPs) with 1,6‐hexamethylenediamine as curing agent. The EUPs themselves were prepared from glycidol and isocyanate‐terminated polyurethanes made from poly(ε‐caprolactone) (PCL) or poly(ethylene glycol) (PEG) and 1,6‐hexamethylene diisocyanate. All the polymers were characterized by conventional methods, and their physical, mechanical, thermal, and degradation properties were studied. The results showed that the degradation rate and mechanical properties of the final products can be controlled by the amount of PEG or PCL present in the EUP. Increasing the PEG content causes an increase of hydrolytic degradation rate, and increasing the PCL content improves the mechanical properties of the final products. Evaluation of cytotoxcicity showed nontoxic behavior of the prepared samples, but the cytocompatibility of these polymers needs to be improved. Copyright © 2006 Society of Chemical Industry
Prospects of ultracold Rydberg gases for quantum information processing
Authors: Reetz‐Lamour M. , Amthor T. , Deiglmayr J. , Westermann S. , Singer K. , de Oliveira A.L. , Marcassa L.G. , Weidemüller M.
Published: August 2006

We present our experiments on the applicability of ultracold Rydberg gases for quantum information processing. As quantum computing relies on entanglement mediated through interparticle interactions, we have experimentally implemented three approaches to induce ultralong‐range interactions between Rydberg atoms: van‐der‐Waals interactions, interactions of permanent dipoles induced by an electric field, and resonant dipole‐dipole interactions (Förster resonances). Advantages and limitations of the approaches are discussed.
Evaluation of the bioavailability of the herbicide prosulfocarb through adsorption on soils and model soil colloids, and through a simple bioassay
Authors: Nègre Michèle , Passarella Iride , Boursier Carlotta , Mozzetti Chiara , Gennari Mara
Published: August 2006

Adsorption isotherms of prosulfocarb were determined on soils with different physicochemical properties. The extent of adsorption increased with the organic carbon content, but the results also suggested the involvement of some inorganic soil surfaces. In order better to understand the role of each soil surface, adsorption–desorption isotherms were determined on model soil colloids consisting of a soil humic acid, a montmorillonite, a synthetic aluminium hydroxide and their associations. The highest adsorption was observed on the humic acid, but it was also confirmed that the montmorillonite interacted with prosulfocarb. In contrast, the aluminium hydroxide was not active and its association with montmorillonite provoked a decrease in adsorption compared with montmorillonite alone. Except for humic acid, the highest adsorption took place on the ternary association montmorillonite–aluminium hydroxide–humic acid. On each surface tested, the adsorption was largely reversible and decreased at increasing pH. The herbicidal activity of prosulfocarb was tested by the determination of the germination and growth of a typical weed, Lolium multiflorum Lam, in contact with prosulfocarb solutions at different concentrations. The herbicide did not prevent the germination of the seeds but inhibited the growth of the roots and leaves. The same test was performed in the presence of the ternary system to evaluate the influence of adsorption on the plant bioavailability. It was concluded that the presence of an adsorptive surface reduced the herbicidal activity and that the simple bioassay proposed could be useful in predicting the extent of adsorption in a given soil. Copyright © 2006 Society of Chemical Industry
Theoretical study of one‐electron bonds in a series of high‐spin lithium–beryllium–hydrogen clusters: “Valence shell single‐electron repulsion” rule and electron localization function analysis
Authors: Chaquin Patrick , Chevreau Hilaire
Published: August 2006

A series of high‐spin clusters containing Li, H, and Be in which the valence shell molecular orbitals (MOs) are occupied by a single electron has been characterized using ab initio and density functional theory (DFT) calculations. A first type (5Li2, n+1LiHn+ (n = 2–5), 8Li2H) possesses only one electron pair in the lowest MO, with bond energies of ∼3 kcal/mol. In a second type, all the MOs are singly occupied, which results in highly excited species that nevertheless constitute a marked minimum on their potential energy surface (PES). Thus, it is possible to design a larger panel of structures (8LiBe, 7Li2, 8Li, 4LiH+, 6BeH, n+3LiH (n = 3, 4), n+2LiH (n = 4–6), 8Li2H, 9Li2H, 22Li3Be3 and 22Li6H), single‐electron equivalent to doublet “classical” molecules ranging from CO to C6H6. The geometrical structure is studied in relation to the valence shell single‐electron repulsion (VSEPR) theory and the electron localization function (ELF) is analyzed, revealing a striking similarity with the corresponding structure having paired electrons. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Quantum statistics of charged particles and fingerprints of wigner crystallization in D dimensions
Authors: March N. H.
Published: August 2006

After a brief summary of the physical arguments underlying Wigner's original concept in 1934 of a quantal electron crystal, theoretical interpretation of a number of experimental findings are presented. These include (i) low‐density carriers in semiconductors in applied magnetic fields in both three, and recently two, dimensions; and (ii) low‐temperature phase diagram of underdoped high Tc cuprates; fullerides with relatively low Tc are also referred to in a related context. Interpretation of areas (i) and (ii) focuses on the relevance of both Fermi–Dirac and anyonic (fractional) statistics, the latter in relation to the proposed melting curve of the two‐dimensional (2D) magnetically induced Wigner solid into the Laughlin liquid phase, which is the seat of the fractional quantum Hall effect. A brief discussion follows of crystalline phases additional to the Wigner solid, namely Skyrmion and Hall crystals. Bose–Einstein statistics is then referred to, but now in relation to finite‐size confined quantal assemblies, with fingerprints of Wigner molecules the focus. Finally, quasi‐1D lattices are considered, both in Bechgaard salts and in the very recent single‐electron counting experiment of Bylander et al. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Product line strategies of new entrants in an established industry: evidence from the U.S. bicycle industry
Authors: Dowell Glen
Published: August 2006

A firm's product line breadth in a given market has both benefits and costs; these effects can be more clearly seen by examining not only the number of products a firm offers, but also the degree of complexity that the product line represents. The effects of breadth are particularly important for new entrants in a relatively mature industry and I examine the breadth–survival relation on new entrants in the bicycle industry in the period 1993–98. I find that firms offering a greater number of products, those with very simple and very complex product lines, and those whose product lines have a moderate degree of overlap with rivals have the highest survival rates. Copyright © 2006 John Wiley & Sons, Ltd.
Direct and interaction effects of top management team and board compositions on R&D investment strategy
Authors: Kor Yasemin Y.
Published: August 2006

This paper examines why firms differ in levels of R&D investment intensity by developing and testing a theory of direct and interaction effects of top management team and board outsider composition on R&D intensity. The theory is tested in a longitudinal sample of technology‐intensive firms that completed an initial public offering. The results indicate that both top management team composition and board composition have direct and additive effects on R&D investment intensity. Also, monitoring by outsider directors does not constitute a universally effective governance mechanism with regard to a firm's R&D investment strategy. Firms opt for lower levels of R&D investment intensity when their outsider‐rich board interacts with a team of managers who have high levels of (1) firm tenure, (2) shared team‐specific experience, or (3) functional heterogeneity. When a firm's competitiveness relies on sustained R&D investments, it is important to note these interaction effects and make adjustments to promote a healthy dialogue between managers and the board. Adjustments could be made to the management team composition (e.g., initiating management turnover to reduce firm tenure) or to the bundle of governance mechanisms (e.g., partially substituting board monitoring with other mechanisms). Copyright © 2006 John Wiley & Sons, Ltd.
Spannungsermittlung punktgelagerter Verglasungen unter Beanspruchung in Scheibenebene
Authors: Maniatis Iris
Published: August 2006

Im vorliegenden Beitrag wird eine Vorgehensweise zur Spannungsermittlung punktgelagerter Verglasungen unter Beanspruchung in Scheibenebene vorgestellt. Zur genauen Erfassung und rechnerischen Abbildung der auftretenden Spannungen sind Kenntnisse über die Kontaktmechanismen und über die Parameter, die Einfluß auf die Spannungsverteilung haben, nötig. Aufgrund der komplexen Ermittlung der Spannungsverteilung im Bohrungsbereich wird die Tragsicherheit bisher meist durch Bauteilversuche nachgewiesen. Eine Alternative stellt die rechnerische Ermittlung mittels der Methode der Finiten Elemente (FEM) dar. Hierzu bedarf es allerdings entsprechender Programmverifizierungen. Mit Hilfe einer analytischen Lösung wird eine Vorgehensweise zur Verifizierung des Finite‐Elemente‐Modells aufgezeigt. Darüber hinaus werden mit dem verifizierten FE‐Modell verschiedene Parameter und deren Einfluß auf die Spannungsverteilung am Bohrloch untersucht.
Aktueller Stand der Regelungen für die Bemessung von tragenden Bauteilen aus Glas
Authors: Siebert Geralt
Published: August 2006

Im aktuellen Baugeschehen haben tragende Bauteile aus Glas einen festen Platz eingenommen. Für einen Nachweis der Verwendbarkeit solcher Bauteile sind einerseits die baurechtlichen Randbedingungen und Hintergründe zu berücksichtigen. Andererseits ist das Wissen der aktuellen und zukünftigen Bemessungsregeln unverzichtbar. In diesem Beitrag wird – auch als Fortsetzung zu [1] – kurz auf die aktuell eingeführten sowie kürzlich im Entwurf veröffentlichten neuen nationalen Regelungen eingegangen. Ein Vergleich zeigt, daß durch die Umstellung auf das Konzept der Teil sicherheitsbeiwerte gleichzeitig noch vorhandene Tragreserven nutzbar gemacht werden konnten.
Chronic treatment with Δ‐9‐tetrahydrocannabinol alters the structure of neurons in the nucleus accumbens shell and medial prefrontal cortex of rats
Authors: Kolb Bryan , Gorny Grazyna , Limebeer Cheryl L. , Parker Linda A.
Published: August 2006

The potential of repeated exposure to Δ9‐tetrahydrocannabinol (Δ9‐THC) to produce long‐lasting changes in synaptic connections in a manner similar to other drugs of abuse was evaluated in Sprague‐Dawley rats. For 12 days, rats received two i.p. injections per day (8 h apart) of vehicle, a low dose of Δ9‐THC (0.5 mg/kg), or escalating doses of Δ9‐THC (0.5–4.0 mg/kg). Thirty days later, they were evaluated for sensitized locomotor activity (during the night cycle) for 60 min on each of three trials. Using a within‐groups design, rats were tested following an injection of vehicle, 0.5 mg/kg Δ9‐THC or 2.0 mg/kg Δ9‐THC. The rats showed no evidence of sensitized locomotor activity in any group. Twenty‐four hours after the final sensitization test, their brains were removed and then processed for Golgi‐Cox staining. Prior exposure to Δ9‐THC (both the low dose and the escalating doses) increased the length of the dendrites as well as the number of dendritic branches in the shell of the nucleus accumbens and in the medial prefrontal cortex, but not in the hippocampus, striatum, orbital frontal cortex, parietal cortex, or occipital cortex. These results are similar to those evident in brains of rats sensitized to amphetamine, and support previous findings that cannabinoids promote DA activity in the mesolimbic DA system. Synapse 60:429–436, 2006. © 2006 Wiley‐Liss, Inc.
Structural and Electronic Characterization of Eu2LiSi3, Eu2LiGe3 and EuxSr2−xLiGe3 Mixed Crystals
Authors: Xie Qinxing , Nesper Reinhard
Published: August 2006

The new rare earth metal Zintl phases Eu2LiSi3, Eu2LiGe3 and the solid solution EuxSr4−xLi2Ge6 have been synthezised by solid state inert gas techniques and their crystal structures been determined from single crystals. Eu2LiSi3 crystallizes in an own structure type which has close relations to the ThSi2 type with lithium being situated on silicon vacancies. This generates a new kind of planar Zintl anion which has an all trans linear chain backbone and terminal Si side groups at half of the silicon atoms of the chain. Eu2LiGe3 forms the α−Ca2LiSi3 structure with an unbranched planar polymeric Zintl anion which has a cis‐trans conformation of the kind (tttctc)n. Both of the polyanions [Si3]5− and [Ge3]5−, respectively are unsaturated with an underoccupied π* system leaving one residual π bond per three Tt atoms (Tt = Si, Ge). Features of the crystal and of the electronic structures are being analysed based on geometrical and on band structure considerations. DOS, partial DOS, Mulliken overlap populations and calculations of the electron localization function (ELF) based on Extended Hückel and on LMTO calculations confirm the bonding structure and reveal preferred localizations of the π bonds.
Cesarean section by choice: Constructing a reproductive rights framework for the debate
Authors: Christilaw Jan E.
Published: August 2006

The question of cesarean section by choice (that is, cesarean delivery in the absence of medical indications) has been hotly debated by the obstetrical profession in recent years. The debate has focused around questions of risks and benefits, and has revolved around questions of obstetrical practice. In this paper, the question will be framed in a reproductive rights context. How does the phenomenon of CSBC (cesarean section by choice) impact women's empowerment? Which reproductive rights might be affected by this question, and what policies are related to its use? FIGO's 1998 statement “Ethical Aspects regarding Cesarean Delivery for Non‐Medical Reasons” is revisited, and, in light of these considerations, its contents are endorsed once again.
A review of the Late Jurassic stegosaurs (Dinosauria, Stegosauria) from the People's Republic of China
Authors: MAIDMENT SUSANNAH C. R. , WEI GUANGBIAO
Published: August 2006

Seven genera of stegosaurian dinosaur have been named on the basis of material from the Upper Jurassic of China, and this represents a diversity of stegosaurs unparalleled around the world at this time. However, many of the original specimens used to diagnose and describe these species are currently unavailable, and the original descriptions and figures are often inadequate. The Chinese stegosaurs have proven ‘unstable’ in the few cladistic analyses of Stegosauria that have been carried out, causing a loss of resolution in cladograms. Supplementary data on previously described specimens are presented here along with a taxonomic revision. Only Tuojiangosaurus multispinus, Chungkingosaurus jiangbeiensis and Gigantspinosaurus sichuanensis are considered to be valid taxa, with autapomorphies pertaining to features of the ilio-sacral blocks and dermal armour in all cases. The holotype specimen of ‘Chialingosaurus kuani’ is a juvenile, bearing no diagnostic characters, and ‘Monkonosaurus lawulacus’ is based on fragmentary and undiagnostic material. ‘Changtusaurus’ and ‘Yingshanosaurus’ have never been described or figured and their whereabouts are unknown, so they are regarded as nomina nuda. This taxonomic revision significantly reduces known stegosaurian diversity worldwide, and shows that the Chinese diversity was similar to that of Europe and North America in the Upper Jurassic. Previously, it had been suggested that the diversity of Chinese stegosaurs indicated an Asian origin for the clade, a claim that cannot now be upheld.
Is undergraduate otorhinolaryngology teaching relevant to junior doctors working in accident and emergency departments?
Authors: Sharma A , Machen K , Clarke B , Howard D
Published: August 2006

Undergraduate ENT teaching provides junior doctors with skills and knowledge useful for the practice of medicine. However, ENT has been removed from the curriculum of nine of the 29 medical schools in the United Kingdom, as it was not deemed relevant to general medical practice. A telephone survey was performed of 20 senior house officers working in accident and emergency (A&E) departments across the United Kingdom. The results showed that 90 per cent felt their undergraduate ENT teaching was directly beneficial to working in A&E, 75 per cent felt they had not received enough undergraduate ENT teaching and 45 per cent currently received no postgraduate teaching whilst working in A&E.

These results illustrate the importance of ENT teaching in the undergraduate curriculum and its value to practising doctors. They highlight the fact that prospective studies are required to examine the effect on junior doctors of changing the curriculum.
Rosen mobilization of the stapes: does it have a place in modern otology?
Authors: Thiel G , Mills R
Published: August 2006

We describe two patients with stapes fixation, in both of whom Rosen mobilization seemed to be the most prudent surgical choice. In both cases, a useful hearing gain was achieved initially. In the patient with otosclerosis, the conductive hearing loss recurred and a stapedectomy was subsequently carried out. In the patient with congenital stapes fixation, the hearing gain was maintained for two years eight months. We believe that this technique still has a place in stapes surgery in rare instances.
Remaking Arctic governance: the construction of an Arctic Inuit polity
Authors: Shadian Jessica
Published: August 2006

This article focuses on the construction of the Inuit Circumpolar Conference (ICC), the aim being to offer the historical context within which the ICC came to serve as a significant voice for Arctic policy making and as a representative of Inuit peoples in general. It explores the role of the ICC in relation to the domestic, regional, and international political events taking place during its formative years in order to provide the basis through which the ICC came to be a political authority in the Arctic. While the main coalescence of events was around the theme of Arctic resource development, each event significantly helped lay the foundation for, and structures under which, Arctic policy would proceed into the future. This includes a changing Arctic narrative that has transformed the Arctic from a being a region concentrated on resource extraction and Cold War security into a region serving as a symbolic pinnacle for global sustainable development. Through the expanded political agency of the ICC and an international focus on the Arctic, a vision of the Arctic has emerged under which it is defined by its natural environment and by the indigenous peoples who inhabit this space. This is an INDIPO project paper (Tennberg 2006).
The United Nations and Antarctica, 2005: the end of the ‘Question of Antarctica’?
Authors: Beck Peter J.
Published: August 2006

In November 2005 the ‘Question of Antarctica’ was taken up yet again by the UN First Committee. Following formal placement upon its agenda in 1983 by the Malaysian government, the UN has discussed the topic regularly, initially annually, then biennially, but more recently upon a triennial basis. As usual, in 2005 UN members were guided by a lengthy report produced for the United Nations Secretary General (UNSG) by the United Nations Environment Programme (UNEP) in order to outline recent developments affecting Antarctica and the Antarctic Treaty system (ATS). In November 2005 the UN First Committee, acting upon proposed amendments advanced by the Malaysian delegation, agreed to a major change of course. Thus, resolution L60, adopted by the committee without a vote, stipulated that the UN, though remaining ‘seized’ of the ‘Question of Antarctica’, would not place the topic upon the agenda of the 63rd. session in 2008. Nor would the UNSG be required, henceforth, to produce a report on Antarctica for members. In December 2005, the UN General Assembly adopted draft resolution L60 as resolution 60/47, once again without a vote. As a result, for the first time since 1983, the UN is no longer scheduled to return to the ‘Question of Antarctica’. Meanwhile, the episode has raised interesting questions about future developments: the UN's role, if any, in the ‘Question of Antarctica’, the direction of Malaysian policy towards the ATS, including membership thereof; the continued ability of the Antarctic Treaty Consultative Parties (ATCPs) to manage Antarctica in a democratic, transparent and accountable manner without attracting criticism from the broader international community; and the relevance of the common heritage principle to the Antarctic region.
The Giacomo Bove Museum, Maranzana, Italy
Authors: Bosco Piero
Published: August 2006

Giacomo Bove (1852–1887) was an officer in the Royal Italian Navy who participated in Nordenskiöld's Vega expedition through the northeast passage, and in other expeditions in various parts of the world. He was, in part, responsible for drawing up plans for an Italian Antarctic expedition to depart in 1881. He died, at the age of 35, after an expedition to the Congo. A small museum in his honour has been established in his home village of Maranzana, Italy.
The structure of common DSM-IV and ICD-10 mental disorders in the Australian general population
Authors: SLADE TIM , WATSON DAVID
Published: August 2006

Background. Patterns of co-occurrence among the common mental disorders may provide information about underlying dimensions of psychopathology. The aim of the current study was to determine which of four models best fits the pattern of co-occurrence between 10 common DSM-IV and 11 common ICD-10 mental disorders.

Method. Data were from the Australian National Survey of Mental Health and Well-Being (NSMHWB), a large-scale community epidemiological survey of mental disorders. Participants consisted of a random population-based sample of 10641 community volunteers, representing a response rate of 78%. DSM-IV and ICD-10 mental disorder diagnoses were obtained using the Composite International Diagnostic Interview (CIDI), version 2.0. Confirmatory factor analysis (CFA) was used to assess the relative fit of competing models.

Results. A hierarchical three-factor variation of a two-factor model demonstrated the best fit to the correlations among the mental disorders. This model included a distress factor with high loadings on major depression, dysthymia, generalized anxiety disorder (GAD), post-traumatic stress disorder (PTSD) and neurasthenia (ICD-10 only); a fear factor with high loadings on social phobia, panic disorder, agoraphobia and obsessive–compulsive disorder (OCD); and an externalizing factor with high loadings on alcohol and drug dependence. The distress and fear factors were best conceptualized as subfactors of a higher order internalizing factor.

Conclusions. A greater focus on underlying dimensions of distress, fear and externalization is warranted.