bluuebunny/crossref_metadata_2025 huggingface dataset:
Age at menopause predicts age at onset of Parkinson's disease
Authors: Ragonese Paolo , D'Amelio Marco , Callari Graziella , Salemi Giuseppe , Morgante Letterio , Savettieri Giovanni
Published: October 2006

We investigated the association between age at onset of Parkinson's disease (PD) and fertile life characteristics in 145 women. Linear regression analyses showed a significant correlation between age at PD onset and age at menopause (P = 0.003), between age at PD onset and fertile life duration (P = 0.008), and a nonsignificant correlation between PD onset and cumulative duration of pregnancies (P = 0.23). These results support the possible role of estrogens in PD. © 2006 Movement Disorder Society
Hypoperfusion of the visual pathway in parkinsonian patients with visual hallucinations
Authors: Matsui Hideaki , Nishinaka Kazuto , Oda Masaya , Hara Narihiro , Komatsu Kenichi , Kubori Tamotsu , Udaka Fukashi
Published: October 2006

Little is known about the developing mechanisms of visual hallucinations in Parkinson's disease. This study aimed to investigate perfusion changes in parkinsonian patients with visual hallucinations using n‐isopropyl‐p‐[123I]iodoamphetamine ([123I]IMP) single photon emission computed tomography imaging. A total of 70 consecutive patients, including 31 patients with visual hallucinations, and 39 patients without hallucinations, participated in this study. Patients with severe cognitive impairment (Mini‐Mental State Examination score < 20), nonvisual hallucinations, or confusion were excluded. We compared brain perfusion changes between the two groups. We found that hallucinatory patients had significant perfusion reductions in the bilateral inferior parietal lobule, inferior temporal gyrus, precuneus gyrus, and occipital cortex compared to nonhallucinatory patients. These results suggested that hypoperfusion of the visual pathway was closely related to visual hallucinations in Parkinson's disease. © 2006 Movement Disorder Society
Cellular uptake mechanisms and potential therapeutic utility of peptidic cell delivery vectors: Progress 2001–2006
Authors: Fischer Peter M.
Published: October 2006

Cell delivery vectors (CDVs) are short amphipathic and cationic peptides and peptide derivatives, usually containing multiple lysine and arginine residues. They possess inherent membrane activity and can be conjugated or complexed with large impermeable macromolecules and even microscopic particles to facilitate cell entry. Various mechanisms have been proposed but it is now becoming clear that the main port of entry into cells of such CDV constructs involves adsorptive‐mediated endocytosis rather than direct penetration of the plasma membrane. It is still unclear, however, how and to what extent CDV constructs are capable of exiting endosomal compartments and reaching their intended cellular site of action, usually the cytosol or the nucleus. Furthermore, although many CDVs can mediate cellular uptake of their cargo and appear comparatively non‐toxic to cells in tissue culture, the utility of CDVs forin vivoapplications remains poorly understood. Whatever the mechanisms of cell entry and disposition, the overriding question as far as potential pharmacological application of CDV conjugates is concerned is whether or not a therapeutic margin can be achieved by their administration. Such a margin will only result if the intracellular concentration in the target tissues necessary to elicit the biological effect of the CDV cargo can be achieved at systemic CDV exposure levels that are non‐toxic to both target and bystander cells. It is proposed that the focus of CDV research now be shifted from mechanisticin vitrostudies with labeled but otherwise unconjugated CDVs toin vivopharmacological and toxicological studies using CDV‐derivatized and other cationized forms of inherently non‐permeable macromolecules of true therapeutic interest. © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 6, 755–795, 2007
Combined use of Overhauser spectroscopy and NMR diffusion experiments for mapping the hydration structure of nucleosides: structure and dynamics of uridine in water
Authors: Seba Hadj B. , Thureau Pierre , Ancian Bernard , Thévand André
Published: October 2006

Complementary results from 13C intermolecular nuclear Overhauser effects (NOE), 1H13C heteronuclear Overhauser spectroscopy (HOSEY) and 1H‐NMR diffusion measurements were used for probing the structure of the first solvation shell of uridine in water. It is demonstrated that a cyclic dihydrate is formed. The two water molecules produce two hydrogen bonds with the two oxygen atoms from the pyrimidine ring and accept only one hydrogen bond from the amide proton. The dihydrate has only a short lifetime as compared with the rotational correlation time of the free nucleoside. The chemical exchange constant of the amide proton with water is then estimated by diffusion experiments. The results are consistent with previous data obtained for uracil in water and provide interesting information about water accessibility in nucleic acid bases. Copyright © 2006 John Wiley & Sons, Ltd.
Analytical solution of the harmonic waves diffraction by a cylindrical lined cavity in poroelastic saturated medium
Authors: Karinski Y. S. , Shershnev V. V. , Yankelevsky D. Z.
Published: October 2006

This paper presents a model for the analysis of plane waves diffraction at a cavity in an infinite homogeneous poroelastic saturated medium, lined by a lining composed of four equal segments. An elastic boundary layer is placed between the cavity lining and the infinite porous medium. The boundary layer is simulated by ‘elastic boundary conditions’ in which the bulk matrix stress is proportional to the relative displacement between the lining and the surrounding medium matrix boundary. In addition, fluid impermeability through the intermediate layer is assumed.

For the frequencies, that differ from the pseudoresonanse frequencies, the problem was reduced to the problem of an ideal elastic medium.

A closed‐form analytical solution of the problem was obtained using Fourier–Bessel series, the convergence of which was proven. It was shown that the number of series terms required to obtain a desired level of accuracy can be determined in advance.

The influence of the medium porosity on the medium dynamic stress concentration was studied. Copyright © 2006 John Wiley & Sons, Ltd.
Influence of dipolar species on charge transport in poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylene vinylene]
Authors: Toman Petr , Nešpůrek Stanislav , Weiter Martin , Vala Martin , Sworakowski Juliusz , Bartkowiak Wojciech , Menšík Miroslav
Published: October 2006

A theoretical study and experimental evidence for a decrease of the charge carrier mobility in poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylene vinylene] (MEH‐PPV) under the influence of dipolar species are presented in this paper. The presence of polar species in the vicinity of an MEH‐PPV chain modifies the on‐chain site energies and consequently, due to random mutual positions and orientations, increases the width of the energy distribution of the chain transport states. The influence of energetic disorder of these states on the charge carrier mobility was modeled by means of the Monte Carlo method, based on a numerical solution of the time‐dependent Schrödinger equation in the tight‐binding approximation. It was shown that the increasing disorder destroys the resonance between charge carrier energies on adjacent sites and, therefore, limits the diffusive charge carrier motion. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis, structural and mechanical properties of porous polymeric scaffolds for bone tissue regeneration based on neat poly(ε‐caprolactone) and its composites with calcium carbonate
Authors: Olah Laszlo , Filipczak Katarzyna , Jaegermann Zbigniew , Czigany Tibor , Borbas Lajos , Sosnowski Stanislaw , Ulanski Piotr , Rosiak Janusz M.
Published: October 2006

The aim of the present study was to develop new materials which could be applicable as bone substitutes or be used in bone tissue engineering. Two types of porous scaffolds based on poly(ε‐caprolactone) (PCL) were investigated. Type 1 scaffolds were prepared by solvent casting/particulate leaching technique, using NaCl with the grain size 250–500 µm as a porogen. In the case of Type 2 scaffolds, the biodegradable polymer was blended with calcium carbonate, which, in contrast to NaCl, is not leached out from the product during manufacture, either in the form of calcite powder or aragonite (needle‐like crystals). Influence of manufacturing technique and initial substrate composition on product properties was investigated. The tests involved porosity measurements, structure analysis by optical and scanning electron microscopy and mechanical studies (determination of compression strength and modulus). The results indicate the important role of the phase exchange process in the formation of micropores. In this process PCL precipitated from its acetone solution in the presence of water creating microporous three‐dimensional polymer structures. The Type 1 scaffolds possessed both micropores and macropores. Good interconnectivity between the pores was observed for samples of the initial porogen content higher than 33%. Microporous samples containing inorganic filler have lower porosity and higher compression strength. For Type 2 scaffolds the shape of filler particles has an important influence on mechanical properties—replacing powder with needle‐like crystals (in the same weight amount) results in a three‐ to five‐fold increase in compression modulus. Copyright © 2006 John Wiley & Sons, Ltd.
Biomacromolecular engineering: design, synthesis and characterization. One‐pot synthesis of block copolymers of arborescent polyisobutylene and polystyrene
Authors: Puskas Judit E. , Kwon Yongmoon
Published: October 2006

Novel arborescent block copolymers comprising of an arborescent rubbery polyisobutylene (PIB) midsegment and glassy polystyrene (PSt) end blocks were prepared by sequential addition of monomers. Synthesis was conducted by the use of 4‐(2‐methoxyisopropyl) styrene as an inimer‐type initiator in conjunction with titanium tetrachloride (TiCl4) in 60:40 (v/v) methylcyclohexane/methyl chloride solvent mixture. Isobutylene was polymerized for 1–2 hr and then prechilled styrene in the same solvent mixture was sequentially added with select additives to the reaction flask. The recovered block copolymers were purified and then characterized by 1H‐NMR, size exclusion chromatograph (SEC), tensile test, atomic force Microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS). Samples with 16.4–32.8 wt% PSt and Mn = 47,600–125,900 g/mol (Mw/Mn = 2.02–4.45) displayed thermoplastic elastomeric properties with 5–9.2 MPa tensile strength and 490–920% elongation. The arborescent block copolymers showed surface morphologies ranging from spherical to cylindrical/lamellar nanometer‐sized discreet PSt phases dispersed in a continuous PIB matrix, with a 10 nm PIB layer on the surface. Drug release profiles of paclitaxel from two arborescent blocks were found to be similar to that measured from Translute®. Copyright © 2006 John Wiley & Sons, Ltd.
In situ synthesis of optically transparent interpenetrating organic/inorganic networks
Authors: Widmaier Jean‐Michel , Bonilla Gabriela
Published: October 2006

Ternary hybrid interpenetrating networks composed of polyurethane (PU), poly(methyl methacrylate) (PMMA) and silica were prepared by in situ bulk polymerization. The inorganic phase was generated from tetraethoxysilane (TEOS) via sol‐gel chemistry. Highly transparent films were successfully synthesized using (trimethoxysilyl)propyl methacrylate (TMSPM) and isocyanatopropyl triethoxy silane (IPTES) as dual coupling agents. In order to minimize undesirable side‐reactions, PU was allowed to prepolymerize first before introduction of water into the reactive medium. According to infrared spectroscopic analysis and thermogravimetric studies of the hybrid materials, the condensation reaction was not complete certainly due to the presence of the organic components. The experimental procedure has to be optimized before any application of these hybrids as damping materials. Copyright © 2006 John Wiley & Sons, Ltd.
Ferrocene containing copolymers with improved electrostatic dissipation properties for advanced applications
Authors: Smith Trent M. , Nelson Gordon L.
Published: October 2006

Polyurethane (PU) and polyimide (PI) copolymers containing a ferrocene oligomer (FcOlig) in the backbone were synthesized and characterized. PU materials with the FcOlig in the chain (PU‐FcOlig) demonstrated improved electrostatic dissipation properties and decreased electrical resistance in comparison to the unmodified PU parent material. The surface resistance decreased nearly 30 times and the volume resistance decreased nearly 12 times with a 3.5% FcOlig reacted in with Rubinate® 9272. The same 3.5% PU‐FcOlig material exhibited an average surface potential resulting from charge deposited of 130 ± 4 V down from 1600 ± 65 V for the unmodified PU. The charge dissipation time to 1/e (initial voltage divided by e) was also decreased to 81 ± 7 msec for 1.5% PU‐FcOlig materials from an average of 934 ± 62 msec for the parent PU. Incorporating the FcOlig into the backbone of a PI (BPDA‐ODA PI FcOlig) had no significant effects on the electrical properties in comparison to the unmodified parent PI (BPDA, 3,3′, 4,4′‐biphenyltetracarboxylic dianhydride; ODA, 3,3′‐oxydianiline). The difference in electrical properties between the ferrocene containing PUs and PIs is the lack of FcOlig blocks on or near the surface of the PI. X‐ray photoelectron spectroscopy (XPS) confirms that on the surface of the ferrocene containing PUs iron in the form of ferrocene is detected, but even after etching the PIs to a depth of 50, 100, 500 Å, and finally scraping the surface with a scalpel no iron was observed. Published in 2006 by John Wiley & Sons, Ltd.
Formation and structure of organized molecular films for fluorinated comb copolymers
Authors: Fujimori Atsuhiro , Masuya Ryosuke , Masuko Toru , Ito Eisuke , Hara Masahiko , Kanai Kaname , Ouchi Yukio , Seki Kazuhiko , Nakahara Hiroo
Published: October 2006

The molecular orientation in monolayer and multilayer films of fluorinated comb copolymers with various monomer ratios can be characterized by in‐plane and out‐of plane X‐ray diffraction (XRD), near‐edge X‐ray absorption fine structures (NEXAFS) spectroscopy at the C K‐edges, and atomic force microscopic observation. And further, the fine structure in the solid state and phase transition behavior of newly synthesized comb copolymers having fluorocarbon and hydrocarbon side‐chains were investigated by temperature controlled wide‐angle X‐ray diffraction (WAXD) and differential scanning calorimetry (DSC). From the WAXD profiles, two kinds of short spacing peaks based on the formation of the sub‐cell for fluorinated and hydrogenated side‐chains were confirmed at 5.0 and 4.1 Å, respectively. Furthermore, two kinds of endothermic peaks, which corresponded to melting peaks of both side‐chain crystals, appeared in the heating process of the DSC thermograms. From these experimental findings, the phase separation structure having the independently packed immiscible side‐chain crystalline formed in the whole polymer crystal. In addition, it was found that these comb polymers formed highly ordered (double) layer structures estimated using WAXD and small‐angle X‐ray scattering (SAXS). These fluorinated comb copolymers form the monolayer on the water surface and their transferred film with phase separated structure at nanometer size on the solid. There were hydrogenated domains at 10–20 nm diameter scales in these phase separated surface structures of the monolayers. From these experimental results, these copolymer monolayers are expected to be used as in new molecular devices such as nano‐lithography based on the surface patterning of polymer nano‐materials. Copyright © 2006 John Wiley & Sons, Ltd.
Prediction of peptide structure: How far are we?
Authors: Thomas Annick , Deshayes Sébastien , Decaffmeyer Marc , Van Eyck Marie Hélène , Charloteaux Benoit , Brasseur Robert
Published: October 2006

Rational design of peptides is a challenge, which would benefit from a better knowledge of the rules of sequence–structure–function relationships. Peptide structures can be approached by spectroscopy and NMR techniques but data from these approaches too frequently diverge. Structures can also be calculated in silico from primary sequence information using three algorithms: Pepstr, Robetta, and PepLook. The most recent algorithm, PepLook introduces indexes for evaluating structural polymorphism and stability. For peptides with converging experimental data, calculated structures from PepLook and, to a lesser extent from Pepstr, are close to NMR models. The PepLook index for polymorphism is low and the index for stability points out possible binding sites. For peptides with divergent experimental data, calculated and NMR structures can be similar or, can be different. These differences are apparently due to polymorphism and to different conditions of structure assays and calculations. The PepLook index for polymorphism maps the fragments encoding disorder. This should provide new means for the rational design of peptides. Proteins 2006. © 2006 Wiley‐Liss, Inc.
A hinge of the endogeneous ATP synthase inhibitor protein: The link between inhibitory and anchoring domains
Authors: Domínguez‐Ramírez L. , Gómez‐Puyou A. , de Gómez‐Puyou M. Tuena
Published: October 2006

The ATP synthase of bovine heart mitochondria possesses a regulatory subunit called the endogenous inhibitory protein (IF1). This subunit regulates the catalytic activity of the F1 sector in the mitochondrial inner membrane. When ΔμH+ falls, IF1 binds to the enzyme and inhibits ATP hydrolysis. On the other hand, the establishment of a ΔμH+ induces the release of the inhibitory action of IF1, allowing ATP synthesis to proceed. IF1 is also involved in the dimerization of soluble F1. Dynamic domain analysis and normal mode analysis of the reported crystallographic structure of IF1 revealed that it has an effective hinge formed by residues 46–52. Molecular dynamics data of a 27 residue fragment confirmed the existence of the hinge. The hinge may act as a regulatory region that links the inhibitory and anchoring domains of IF1. The residues assigned to the hinge are conserved between mammals, but not in other species, such as yeasts. Likewise, unlike the heart inhibitor, the yeast protein does not have the residues that allow it to form stable dimers through coiled‐coil interactions. Collectively, the data suggest that the hinge and the dimerization domain of the inhibitor protein from bovine heart are related to its ability to form stable dimers and to interact with other subunits of the ATP synthase. Proteins 2006. © 2006 Wiley‐Liss, Inc.
On the vibrational properties of CsD2PO4 crystal
Authors: Shchur Ya.
Published: October 2006

Lattice dynamics simulation of CsD2PO4 crystal is performed in a quasiharmonic approximation using the atomistic potential involving Coulomb, short‐range, covalent, van der Waals and hydrogen‐bonded interactions. The phonon dispersion relations, partial density of states, velocities of ultrasonic waves and atomic displacement parameters are calculated both in the paraelectric and ferroelectric phases. The obtained data enable us to give a detailed description of the observed Raman and IR spectra and to determine the eventual local symmetry of the PO4 groups. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Systematic calculation of molecular vibrational spectra through a complete Morse expansion
Authors: Bordoni Andrea , Manini Nicola
Published: October 2006

We propose an accurate and efficient method to compute vibrational spectra of molecules, based on exact diagonalization of an algebraically calculated matrix based on powers of Morse coordinate. The present work focuses on the 1D potential of diatomic molecules: as typical examples, we apply this method to the standard Lennard‐Jones oscillator, and to the ab initio potential of the H2 molecule. Global cm−1 accuracy is exhibited through the H2 spectrum, obtained through the diagonalization of a 30 × 30 matrix. This theory is at the root of a new method to obtain globally accurate vibrational spectral data in the context of the multi‐dimensional potential of polyatomic molecules, at an affordable computational cost. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Off‐atomic site charges in some anions, metal cations, and complexes: Significance for electrostatic properties and binding
Authors: Singh A. K. , Mishra P. C.
Published: October 2006

Electronic structures and properties of several anions, metal cations, and their complexes with neutral molecules were investigated at the HF/6‐31G** and B3LYP/6‐31G** levels of theory. Charges shifted from atomic sites due to atomic orbital hybridization called hybridization displacement charges (HDC) were investigated in detail. It has been found that many components of HDC are associated with each atom of ion that are shifted from the atomic sites, those associated with metal cations being shifted by large distances as found previously in electrically neutral systems. It is shown that atomic orbitals are appreciably rehybridized in going from neutral molecules to anions and cations. Molecular dipole moments and surface molecular electrostatic potentials (MEP) are obtained satisfactorily using HDC for the various types of species mentioned above. In the OH−H2O complex, reversal of direction of shift of an HDC component associated with the hydrogen atom of H2O involved in hydrogen bonding, indicates that the hydrogen bond between OH−and H2O would have some covalent character. Other atomic site‐based point charge models cannot provide such information about the nature of bonding. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem 2007
Worldwide migration of parasitic mites as a result of bumblebee commercialization
Authors: Goka Kouichi , Okabe Kimiko , Yoneda Masahiro
Published: October 2006

We investigated the status of infestation by a tracheal mite, Locustacarus buchneri, in natural populations of a Japanese native bumblebee species, Bombus hypocrita, collected on Hokkaido Island and in the Aomori prefecture between 1997 and 2001. We also investigated mite infestation in commercial colonies of the European bumblebee, Bombus terrestris, imported from the Netherlands and Belgium, and the Japanese native species, B. ignitus, imported from the Netherlands, between 1997 and 2001. We detected mites in natural populations of the two B. hypocrita subspecies and in the commercial colonies. Analysis of variations in 535 bp sequences of the mitochondrial cytochrome oxidase subunit 1 (CO1) gene showed that the mite haplotypes in the native populations and in the imported colonies did not overlap in 1997–1999, but in 2000–2001 some mites possessing European CO1 haplotypes were detected in the natural populations of Japanese native bumblebees. In addition, many mites possessing Japanese haplotypes were detected in the imported commercial colonies from Europe. Considering the fact that the Japanese native bumblebees, B. hypocrita, were once exported to Europe for commercialization, these results suggest that bumblebee commercialization has caused overseas migration and cross‐infestation of parasitic mites among natural and commercial colonies. However, because the Japanese and European CO1 haplotypes were closely related, there was a possibility that the European haplotypes found in the mites in the Hokkaido Island revealed native variation. To clarify the status of mite invasion, further detailed analysis of genetic variation of the mite, using other genetic markers on additional samples, need to be performed.
Children of mothers at psychosocial risk growing up: A follow up at the age of 16
Authors: Wadsby Marie , Göran Svedin Carl , Sydsjö Gunilla
Published: October 2006

The aim of the present study was to make a 16‐year follow‐up of children of psychosocial risk mothers as concerns emotional/behavioural problems, self‐esteem, life events, and academic grades. Forty‐three teenagers (index group) and 61 reference teenagers were personally interviewed and asked to answer the Youth Self‐report (YSR), the Self‐image questionnaire I Think I Am, and a Life Event questionnaire. Their final grades from the 9‐year compulsory school were studied. The results showed that boys, especially the sons from families with alcohol/drug problems, displayed poorer mental health, a more negative self‐image, had experienced more negative life events, and had to a greater extent not successfully completed the 9‐year compulsory school. More teenagers in the index group had been placed in foster care, had a less positive outlook about their future, were more often smokers, and more of them (girls) had seriously considered committing suicide than the teenagers in the reference group.

It was concluded that boys of psychosocial risk mothers are less well off than teenagers of non‐risk mothers at the age of 16 as concerns psychosocial well being. It is of great importance to devote attention to these children at an early stage of life in order to be able to provide them with the support that may prevent development of future problems.
In vitro reconstitution of a transport complex containing Rab27a, melanophilin and myosin Va
Authors: Wu Xufeng , Sakamoto Take , Zhang Fang , Sellers James R. , Hammer John A.
Published: October 2006

Rab27a and melanophilin (Mlph) are required in vivo to form a melanosome receptor for myosin Va in which Rab27a anchored in the melanosome membrane recruits Mlph, which in turn recruits myosin Va. Here, we show by reconstitution using purified proteins that Rab27a and Mlph are sufficient to form a transport complex with myosin Va in vitro. These results suggest that additional proteins are not required in vivo for assembly of the myosin Va receptor, although other proteins may associate with this tripartite complex to regulate its activity and/or to assist Rab27a in anchoring the complex to the melanosome membrane.
Characterisation of the RNA binding properties of the coronavirus infectious bronchitis virus nucleocapsid protein amino‐terminal region
Authors: Spencer Kelly-Anne , Hiscox Julian A.
Published: October 2006

The coronavirus nucleocapsid (N) protein binds viral RNA to form the ribonucleocapsid and regulate RNA synthesis. The interaction of N protein with viral RNA was investigated using circular dichroism and surface plasmon resonance. N protein underwent a conformational change upon binding viral RNA and the data indicated electrostatic interactions were involved in the binding of the protein to RNA. Kinetic analysis suggested the amino‐terminal region facilitates long‐range non‐specific interactions between N protein and viral RNA, thus bringing the RNA into close proximity to N protein allowing specific contacts to form via a ‘lure’ and ‘lock’ mechanism.
Neurogenic effect of vascular endothelial growth factor during germ layer formation of human embryonic stem cells
Authors: Kim Byung-Kak , Kim Sung-Eun , Shim Joong-Hyun , Woo Dong-Hun , Gil Jung-Eun , Kim Suel-Kee , Kim Jong-Hoon
Published: October 2006

Vascular endothelial growth factor (VEGF), a potent mitogen for vascular endothelial cells, has been suggested as a modulator that is involved in neurogenesis as well as angiogenesis. Here, we directly examined the effect of VEGF on neuroectodermal differentiation using human embryonic stem cells (hESCs). VEGF treatment upregulated the expression of neuroectodermal genes (Sox1 and Nestin) during germ layer formation in embryoid bodies (EBs) and efficiently increased the number of neural rosettes expressing both Pax6 and Nestin. The neural progenitors generated from VEGF‐treated EBs further differentiated into cells that showed a similar pattern of gene expression observed in the development of dopaminergic neurons upon terminal differentiation. These results support the neurogenic effect of VEGF on hESC differentiation.
Characterization of DIDS‐sensitive ATP accumulation in brain synaptic vesicles
Authors: Zalk Ran , Shoshan-Barmatz Varda
Published: October 2006

ATP is an excitatory neurotransmitter in the central and peripheral nervous system. We investigated ATP accumulation in highly purified brain synaptic vesicles (SVs). Based on the amount of ATP accumulated in SVs under the conditions used, ATP is not transported against a concentration gradient but rather appears to have a ΔμH+‐independent mechanism. ATP transport was inhibited by DIDS and NEM, but was not affected by Mg2+ or by pre‐incubation with nucleotides. These results suggest a unique transport mechanism that does not involve exchange with other nucleotides or protons, unlike other known neurotransmitter transport systems.
Identification of the zinc binding ligands and the catalytic residue in human aspartoacylase, an enzyme involved in Canavan disease
Authors: Herga S. , Berrin J.-G. , Perrier J. , Puigserver A. , Giardina T.
Published: October 2006

Canavan disease is an autosomal‐recessive neurodegenerative disorder caused by a lack of aspartoacylase, the enzyme that degrades N‐acetylaspartate (NAA) into acetate and aspartate. With a view to studying the mechanisms underlying the action of human aspartoacylase (hASP), this enzyme was expressed in a heterologous Escherichia coli system and characterized. The recombinant protein was found to have a molecular weight of 36 kDa and kinetic constants K
m and k
cat of 0.20 ± 0.03 mM and 14.22 ± 0.48 s−1, respectively. Sequence alignment showed that this enzyme belongs to the carboxypeptidase metalloprotein family having the conserved motif H21xxE24(91aa)H116. We further investigated the active site of hASP by performing modelling studies and site‐directed mutagenesis. His21, Glu24 and His116 were identified here for the first time as the residues involved in the zinc‐binding process. In addition, mutations involving the Glu178Gln and Glu178Asp residues resulted in the loss of enzyme activity. The finding that wild‐type and Glu178Asp have the same K
m but different k
cat values confirms the idea that the carboxylate group contributes importantly to the enzymatic activity of aspartoacylase.
Feminists and the Courts: Measuring Success in Interest Group Litigation in Canada
Authors: Morton F. L. , Allen Avril
Published: October 2006

This study proposes a new model for assessing success in interest group litigation. The model is applied to 47 appeal court rulings concerning feminist issues in 21 cases involving the Canadian Charter of Rights and Freedoms and 26 non-Charter cases. The study operationalizes the concept of ''success'' by including not just outcome (''who wins''), but also the effect of the case on the ''policy status quo'' (PSQ) and the creation of favourable or unfavourable legal resources (precedents). Feminist claims prevailed in 72 per cent of the cases. The PSQ optic reveals that previous studies overstate the significance of feminist losses (13), since only three of these changed the PSQ in a direction opposed by feminists. There were 17 cases that changed the PSQ in a direction desired by feminists. Feminist litigation has been most successful in the policy areas of abortion, private-sector discrimination and pornography. Success has been lowest in the areas of sexual assault and income tax. These findings suggest that interest group litigation can achieve significant policy change and that the scope of policy studies should be expanded to include judge-made policy.
Religious Freedom and Equality Concerns under the Canadian Charter of Rights and Freedoms
Authors: Smithey Shannon Ishiyama
Published: October 2006

Section 2(a) of the Canadian Charter of Rights and Freedoms guarantees freedom of conscience and religion. In interpreting the Charter, the courts have interpreted this provision to prevent the legislatures from discriminating against religious minorities by promoting particular religious practices. Judges have been much less willing to protect religious minority groups from secular laws that interfere with their religious convictions. The religion cases hold important implications for those concerned about cultural diversity and the equality of Canada's many ethnic communities, as well as for the debate over the increased power of courts under the Charter.
ARISTOTLE AND EPISODIC TRAGEDY
Authors: FINKELBERG MARGALIT
Published: October 2006

It is no exaggeration to say that Aristotle's Poetics is one of the most influential documents in the history of Western tradition. Not only, after its re-discovery in the early sixteenth century, did it dominate literary theory and practice for no less than three hundred years. Even after it had lost its privileged status – first to the alternative theories of literature brought forth by the Romantic movement and then to the literary theory and practice of twentieth-century modernism – the Poetics still retained its role of the normative text in opposition to which those new theories were being formulated. It will suffice to bring to mind the explicitly non-Aristotelian theory of drama developed by Bertold Brecht to see that, even when rejected, it was the Poetics that dictated the agenda of the theorists.

This has changed in the last thirty years, with the emergence of post-modern literary theory. Although in the questioning of the notions of closure, of artistic illusion, of unity of plot the post-modern theory owes much more than it cares to admit to such modernists as Brecht or Adorno and through them to Aristotle, the damnatio memoriae it has imposed on the Poetics is so thorough that some theorists seem to be hardly aware of the very fact of its existence. This is probably why many theorists, in their privileging of emotional distancing over identification, meta-theatrality over illusion, formal and semantic openness over determinacy and closure, find their models in Chinese, Japanese, Indian, and other non-Western literary traditions rather than in ancient Greece. That is to say, in so far as Aristotle is no longer considered relevant to literary theory, Greek literary tradition too is not considered relevant. The tacit presupposition on which this attitude is based is that Aristotle's Poetics adequately represents ancient Greek literary practice.
THE TRIER CEILING: POWER AND STATUS ON DISPLAY IN LATE ANTIQUITY
Authors: ROSE MARICE E.
Published: October 2006

The fourth-century painted ceiling at Trier, Germany was destroyed less than two decades after it was decorated, yet today it is one of the best-known monuments of Late Antique Gaul (figure 1). In excavations begun by Theodor Kempf in 1945, archaeologists collected the ceiling's fragments from the ruins of a Roman house beneath the city's Romanesque cathedral. Painstaking assembly of the plaster fragments into their original form was completed in 1980. Now displayed in the Trier Episcopal Museum, the ceiling is a rare example of Late Antique domestic painting. It comprises fifteen trompe l'oeil coffers which are outlined by red and green borders and a yellow guilloche. Each coffer contains an image of a different subject; bust-length female and male single figures alternate with pairs of putti in various active poses.

The ceiling's rarity, its mysterious, unidentified figures, and the possibility proposed by Kempf that it belonged to a palace built by the emperor Constantine have made it the subject of extensive scholarship. Because conservators assembled the ceiling over a thirty-five year span and individual scenes were published as they were completed, the first scholars of the ceiling studied sections in isolation from the whole monument. Attention first focused on the depictions of the woman with the mirror and the woman with the jewel box, because they were the first single figures to be restored and published. Many archaeologists and art historians concentrated on identifying the women as portraits of Constantine's family. Irving Lavin took a different approach and carefully addressed the painting's classicizing style. Scholars in the 1980s, with the advantage of the ceiling's completed restoration, have considered the ceiling as a thematic whole.
IV The Orator's Education
Authors: Steel Catherine
Published: October 2006

The order of chapters in this book may seem paradoxical: the finished orator is considered before the processes by which he reached that state are examined. The order is indeed back-to-front from the perspective of an individual orator's trajectory, whose training must inevitably precede his activity. But in the wider context of an attempt to understand the nature of oratorical training in the Roman world it makes sense to move from the practising orator back to the embryonic form, since the expectations and norms imposed on the fully fledged orator are the foundations which support the system of oratorical education. This observation does not imply any necessary confidence that Roman oratorical education was designed for the creation of orators who met the criteria for and defused the anxieties about oratory which I discussed in the previous chapter. And even if the material which a modern audience can access did suggest that Roman oratorical education was indeed good at producing Roman orators, there is of course no guarantee that actual practice in classrooms across the Empire bore any relation to these writings or displayed any competence at its task. But an awareness of the practice of oratory can usefully inform analysis of how orators were trained.
“Belsenitis”: Liberating Belsen, Its Hospitals, UNRRA, and Selection for Re-emigration, 1945–1948
Authors: Weindling Paul
Published: October 2006

Argument

The liberation of the concentration camp at Bergen-Belsen has remained controversial with opinion divided over whether the British military and subsequently the British zonal administration responded adequately to the plight of survivors. This paper reconsiders the evidence on health conditions at Bergen-Belsen. At first the British underestimated the incidence of typhus and the delay in taking effective measures caused the death rate to remain high. In the longer term, measures for psychotic, old, and infirm DPs were inadequate as criteria that favored the fit and able-bodied were applied when selecting migrants.
Technique for determining midlatitude O+/H+ transition heights from topside ionograms
Authors: Webb Phillip A. , Benson Robert F. , Grebowsky Joseph M.
Published: October 2006

The midlatitude O+/H+ transition height (where the H+ and O+ number densities are equal) is of importance because it is where the topside altitude distribution of the dominant ions transitions from the ionospheric F region into the plasmasphere, which is considered the inner region of the magnetosphere. This transition height can be determined by fitting ionospheric topside sounder–derived electron density (Ne) profiles to analytical H+ and O+ functions. There are four variables involved in this process, two involving ion number densities and two involving the electron temperature Te. The density variables are the H+ density at the height of the satellite and the O+ density at the base of the profile (taken as 400 km). The temperature variables have been treated using different approaches. In an earlier investigation, diffusive equilibrium ion density profiles, based on an earlier Titheridge height‐varying electron temperature function, were used to fit the Ne profiles in which the electron temperature Te and the Te altitude gradient at a base height of 400 km, denoted by T0 and G0, respectively, were free variables. In the present work, T0 and G0 are constrained by using a later Titheridge empirical temperature model. Alternatively, when in situ Langmuir probe Te determinations are available, the problem reduces to one with only one free temperature variable. All three of these approaches, using Titheridge's revised height‐varying electron temperature function, are applied to a sequence of midlatitude ISIS 2–derived Ne profiles obtained during a period of prolonged high magnetic activity. The results indicate that in the inner plasmasphere, where the transition height is slowly varying, the approach based on the two free Te parameters (T0 and G0) agrees well with the one using the Langmuir probe input. In the region where the transition height is rapidly increasing, however, the approach based on the empirical temperature model produced the most consistent results for the O+/H+ transition height.
Seasonal and interannual variations of top‐of‐atmosphere irradiance and cloud cover over polar regions derived from the CERES data set
Authors: Kato Seiji , Loeb Norman G. , Minnis Patrick , Francis Jennifer A. , Charlock Thomas P. , Rutan David A. , Clothiaux Eugene E. , Sun‐Mack Szedung
Published: October 2006

The daytime cloud fraction derived by the Clouds and the Earth's Radiant Energy System (CERES) cloud algorithm using Moderate Resolution Imaging Spectroradiometer (MODIS) radiances over the Arctic from March 2000 through February 2004 increases at a rate of 0.047 per decade. The trend is significant at an 80% confidence level. The corresponding top‐of‐atmosphere (TOA) shortwave irradiances derived from CERES radiance measurements show less significant trend during this period. These results suggest that the influence of reduced Arctic sea ice cover on TOA reflected shortwave radiation is reduced by the presence of clouds and possibly compensated by the increase in cloud cover. The cloud fraction and TOA reflected shortwave irradiance over the Antarctic show no significant trend during the same period.
Detection of oppositely directed reconnection jets in a solar wind current sheet
Authors: Davis M. S. , Phan T. D. , Gosling J. T. , Skoug R. M.
Published: October 2006

We report the first two‐spacecraft (Wind and ACE) detection of oppositely directed plasma jets within a bifurcated current sheet in the solar wind. The event occurred on January 3, 2003 and provides further direct evidence that such jets result from reconnection. The magnetic shear across the bifurcated current sheet at both Wind and ACE was ∼150°, indicating that the magnetic shear must have been the same at the reconnection site located between the two spacecraft. These observations thus provide strong evidence for component merging with a guide field ∼ 30% of the antiparallel field. The dimensionless reconnection rate based on the measured inflow was 0.03, implying fast reconnection.
Heat flux in magnetospheric convection: A calculation based on adiabatic drift theory
Authors: Liu W. William
Published: October 2006

Empiric evidence and theoretical argument indicate that magnetospheric convection is globally sub‐adiabatic. Reconciliation of the sub‐adiabaticity with the underlying adiabatic particle drifts is a problem that has not been conclusively demonstrated. In this paper, through an ensemble average, we show that the Rice Convection Model contains a heat flux due to thermal inequilibrium between two adjacent flux tubes of equal volume. The averaged theory is based on field variables obeying a set of partial differential equations (Eulerian formulation), instead of conservative variables advecting with fluid elements (Langrangian formulation). We apply the theory to investigate a one‐dimensional case of subadiabatic variation of thermodynamic properties in the plasma sheet.
Southern Ocean warming due to human influence
Authors: Fyfe John C.
Published: October 2006

I show that the latest series of climate models reproduce the observed mid‐depth Southern Ocean warming since the 1950s if they include time‐varying changes in anthropogenic greenhouse gases, sulphate aerosols and volcanic aerosols in the Earth's atmosphere. The remarkable agreement between observations and state‐of‐the art climate models suggests significant human influence on Southern Ocean temperatures. I also show that climate models that do not include volcanic aerosols produce mid‐depth Southern Ocean warming that is nearly double that produced by climate models that do include volcanic aerosols. This implies that the full effect of human‐induced warming of the Southern Ocean may yet to be realized.
Mass balance of glaciers and ice caps: Consensus estimates for 1961–2004
Authors: Kaser G. , Cogley J. G. , Dyurgerov M. B. , Meier M. F. , Ohmura A.
Published: October 2006

Working with comprehensive collections of directly‐measured data on the annual mass balance of glaciers other than the two ice sheets, we combine independent analyses to show that there is broad agreement on the evolution of global mass balance since 1960. Mass balance was slightly below zero around 1970 and has been growing more negative since then. Excluding peripheral ice bodies in Greenland and Antarctica, global average specific balance for 1961–1990 was −219 ± 112 kg m−2 a−1, representing 0.33 ± 0.17 mm SLE (sea‐level equivalent) a−1. For 2001–2004, the figures are −510 ± 101 kg m−2 a−1 and 0.77±0.15 mm SLE a−1. Including the smaller Greenland and Antarctic glaciers, global total balance becomes 0.38 ± 0.19 mm SLE a−1 for 1961–1990 and 0.98 ± 0.19 mm SLE a−1 for 2001–2004. For 1991–2004 the glacier contribution, 0.77 ± 0.26 mm SLE a−1, is 20–30% of a recent estimate of 3.2 ± 0.4 mm a−1 of total sea‐level rise for 1993–2005. While our error estimates are not rigorous, we believe them to be liberal as far as they go, but we also discuss several unquantified biases of which any may prove to be significant.
Regulation of vascular nitric oxide in vitro and in vivo; a new role for endogenous hydrogen sulphide?
Authors: Ali M Y , Ping C Y , Mok Y‐YP , Ling L , Whiteman M , Bhatia M , Moore P K
Published: October 2006

Background and Purpose:

The aim of these experiments was to evaluate the significance of the chemical reaction between hydrogen sulphide (H2S) and nitric oxide (NO) for the control of vascular tone.

Experimental Approach:

The effect of sodium hydrosulphide (NaHS; H2S donor) and a range of NO donors, such as sodium nitroprusside (SNP), either alone or together, was determined using phenylephrine (PE)‐precontracted rat aortic rings and on the blood pressure of anaesthetised rats.

Key Results:

Mixing NaHS with NO donors inhibited the vasorelaxant effect of NO both in vitro and in vivo. Low concentrations of NaHS or H2S gas in solution reversed the relaxant effect of acetylcholine (ACh, 400 nM) and histamine (100 μM) but not isoprenaline (400 nM). The effect of NaHS on the ACh response was antagonized by CuSO4 (200 nM) but was unaffected by glibenclamide (10 μM). In contrast, high concentrations of NaHS (200–1600 μM) relaxed aortic rings directly, an effect reduced by glibenclamide but unaffected by CuSO4. Intravenous infusion of a low concentration of NaHS (10 μmol kg‐1 min‐1) into the anaesthetized rat significantly increased mean arterial blood pressure. L‐NAME (25 mg kg‐1, i.v.) pretreatment reduced this effect.

Conclusions and Implications:

These results suggest that H2S and NO react together to form a molecule (possibly a nitrosothiol) which exhibits little or no vasorelaxant activity either in vitro or in vivo. We propose that a crucial, and hitherto unappreciated, role of H2S in the vascular system is the regulation of the availability of NO.

British Journal of Pharmacology (2006) 149, 625–634. doi:10.1038/sj.bjp.0706906