bluuebunny/crossref_metadata_2025 huggingface dataset:
Planar distribution of the galaxies in the Local Group
Authors: Pasetto S. , Chiosi C. , Grebel E.K.
Published: November 2008

Adopting known data on positions and distances, we make use of analytical geometry and look for the plane that minimizes the distances of all galaxies to it. A planar distribution is found. We apply Hamilton's principle of minimum action to investigate the dynamics of the two major systems of the Local Group, the Milky Way and Andromeda, under the action of forces exerted by nearby galaxies or groups external to the Local Group. We find that the planar distribution is fully compatible with the minimum action and that the external force field is likely parallel to the plane. It pulls the galaxies of the Local Group without altering their planar distribution. Special care is paid to evaluate the robustness of this result. We present an explanation in the linear regime of the numerical results based on the compression effect described with the tidal tensor. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local group dwarf galaxies in the ΔCDM paradigm
Authors: Peñarrubia J. , Navarro J.F. , McConnachie A.W.
Published: November 2008

We report the results of two theoretical studies that examine the dynamics of stellar systems embedded within cold dark matter (CDM) halos in order to assess observational constraints on the dark matter content of Local Group dwarf spheroidals (dSphs). (i) Firstly, approximating the stellar and dark components by King and NFW models, respectively, we calculate the parameters of dark halos consistent with the kinematics and spatial distribution of stars in dSphs as well as with cosmological N‐body simulations. (ii) Subsequently, N‐body realization of these models are constructed to study the evolution of dwarf spheroidal galaxies (dSphs) driven by galactic tides. The analytical estimates highlight the poor correspondence between luminosity and halo mass. In systems where data exist, the stellar velocity dispersion profiles remains flat almost to the nominal “tidal” radius, implying that stars are deeply embedded within the dwarf halos and are therefore quite resilient to tidal disruption. This is confirmed by our N‐body experiments: halos need to lose more than 90% of their original mass before stars can be stripped. As tidal mass loss proceeds, the stellar luminosity, L, velocity dispersion, σ0, central surface brightness, Σ0, and core radius, Rc, decrease monotonically. Remarkably, the evolution of these parameters is solely controlled by the total amount of mass lost from within the luminous radius, which permit us to derive a tidal evolutionary track for each of them. This information is used to examine whether the newly‐discovered ultra‐faintMilkyWay dwarfs are tidally‐stripped versions of the “classical”, bright dwarfs. Although dSph tidal evolutionary tracks parallel the observed scaling relations in the luminosity‐radius plane, they predict too steep a change in velocity dispersion compared with the observational estimates. The ultra‐faint dwarfs are thus unlikely to be the tidal remnants of systems like Fornax, Draco, or Sagittarius. Despite spanning four decades in luminosity, dSphs appear to inhabit halos of comparable peak circular velocity, lending support to scenarios that envision dwarf spheroidals as able to form only in halos above a certain mass threshold. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cold stellar streams and dark matter substructure
Authors: Quinn D.P. , Wilkinson M.I. , Irwin M.J.
Published: November 2008

We present preliminary results from numerical experiments to examine the effect of dark matter subhaloes on the coherence of Cold Stellar Streams. We show that the evolution of the globular cluster, Pal 5, in a smooth Galactic potential can not account for the structure seen in its tidal tails. Work is ongoing to design indices that quantify the impact of subhaloes on stellar streams, and which may be measured from current observations of Pal 5. We introduce simple examples of indices that we use to analyse the numerical experiments and report on the potential of this approach to yield useful clues about the nature of Dark Matter. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Starburst triggered by compressive tides in galaxy mergers
Authors: Renaud F. , Theis Ch. , Boily C.M.
Published: November 2008

The tidal field of galaxies is known generally to be disruptive. However, in the case of galaxy mergers, a compressive mode of tidal wave may develop and last long enough to cocoon the formation of star clusters. Using an N‐body simulation of the Antennae galaxies, we derive the positions of these compressive regions and the statistics of their duration. Excellent agreement between the spatial distribution of tides and observed young clusters is found, while the characteristic e‐folding times of 10 to 30 Myr derived for the tidal field compare well with cluster formation time‐scales. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Galactic warp as seen from 2MASS survey
Authors: Robin A.C. , Reylé C. , Marshall D.J.
Published: November 2008

The 2MASS survey is used to trace the shape of the external Galaxy where an asymmetric warp is detected. We use the Besançon Galaxy model to quantify the parameters of the stellar warp in the outer part of the Galaxy. The shape of the stellar warp is then compared with previous results and with similar structures in gas and dust. We find new constraints on the stellar warp, which is shown to be not symmetrical on both sides of the Galaxy, similar to observations of H I. The positive longitude side is found to be easily modeled with a normal warp but with a slope significantly smaller than the slope seen in the H I warp. At negative longitudes, the warp presents peculiarities which are not well reproduced by any model, even with a 3‐Fourier mode warp. Finally, comparing with the warp seen in the dust, it seems to follow a slope intermediate between the gas and the stars. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamical evolution of the mass function and radial profile of the Globular Cluster systems of the Milky Way and M87
Authors: Shin J. , Kim S.S. , Takahashi K.
Published: November 2008

Evolution of the mass function (MF) and radial distribution (RD) of the globular cluster (GC) systems of the Milky Way and M87 are calculated using an advanced and realistic Fokker‐Planck (FP) model that considers dynamical friction, disk/bulge shocks, and eccentric cluster orbits. We perform hundreds of FP calculations with different initial cluster conditions, and then search a wide parameter space for the best‐fit initial GC MF and RD that evolves into the observed present‐day GC MF and RD. By allowing both MF and RD of the initial GC system to vary, we find that in case of the Milky Way, our best‐fit models have a higher peak mass for a log‐normal initial MF and a higher cutoff mass for a powerlaw initial MF than previous estimates. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intracluster Planetary Nebulae in the Hydra I cluster
Authors: Ventimiglia G. , Arnaboldi M. , Gerhard O.
Published: November 2008

Using the Multislit Imaging Spectroscopy (MSIS) technique at the FORS2 spectrograph on VLT‐UT1, we have identified 60 Intracluster Planetary Nebula (ICPN) candidates associated with the Intracluster Light (ICL) in the central region of the Hydra I cluster. Hydra I is a medium compact, relatively near (∼50 Mpc), rich cluster in the southern hemisphere. Here we describe the criteria used to select emission sources and present the evidence for these PN candidates to be associated with the ICL in the Hydra I cluster. We also show, using the luminosity‐specific planetary nebulae number, the α parameter, that the expected number of PNs associated with the stellar population of the central cD galaxy NGC 3311 in the cluster is close to the number of PNs detected. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of compact binary population in dense stellar systems: A Boltzmann approach
Authors: Banerjee S. , Ghosh P.
Published: November 2008

We introduce a Boltzmann scheme for studying the evolution of compact‐binary populations in globular clusters, wherein dynamical formation processes like tidal capture and exchange encounters, and destruction processes like dissociation are incorporated, as well the binary‐hardening processes. Our approach is in two steps – we first study in a continuous limit, introducing the inherent stochasticity of the dynamical processes in the next step, using a stochastic version of the Boltzmann equation. We show that the continuous limit is indeed an excellent representation of the average of many “realizations” of the stochastic calculations. We focus on the evolution of the number of X‐ray binaries NXB in globular clusters, and also their orbital period distribution. In particular, we study the dependence of NXB on two globular cluster parameters, characterizing the star‐star and star‐binary encounter rates, which we call Verbunt parameters. We show that our computed theoretical trends in NXB with the Verbunt parameters are in good agreement with the recent observations of Galactic globular‐cluster X‐ray binaries. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High resolution in z ‐direction: The simulation of disc‐bulge‐halo galaxies using the particle‐mesh code SUPERBOX
Authors: Bien R. , Just A. , Berczik P. , Berentzen I.
Published: November 2008

SUPERBOX is known as a very efficient particle‐mesh code with highly‐resolving sub‐grids. Nevertheless, the height of a typical galactic disc is small compared to the size of the whole system. Consequently, the numerical resolution in z direction, i. e. vertically with respect to the plane of the disc, remains poor. Here, we present a new version of SUPERBOX that allows for a considerably higher resolution along z. The improved code is applied to investigate disc heating by the in‐fall of a galaxy satellite. We describe the improvement and communicate our results. As an important application we discuss the disruption of a dwarf galaxy within a disc‐bulge‐halo galaxy that consists of some 106 particles. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
What do dynamical cluster masses really tell us about dynamics?
Authors: de Grijs R. , Kouwenhoven M.B.N. , Goodwin S.P.
Published: November 2008

The diagnostic age versus mass‐to‐light ratio diagram is often used in attempts to constrain the shape of the stellar initial mass function, and the stability and the potential longevity of extragalactic young to intermediate‐age massive star clusters. Here, we explore the pitfalls associated with this approach and its potential for use with Galactic open clusters. We conclude that for an open cluster to survive for any significant fraction of a Hubble time (in the absence of substantial external perturbations), it is a necessary but not a sufficient condition to be located close to the predicted photometric evolutionary sequences for ‘normal’ simple stellar populations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Galactic and stellar dynamics in the era of high resolution surveys
Authors: Boily C.M. , Combes F. , Hensler G. , Spurzem R.
Published: November 2008

The conference Galactic and Stellar Dynamics in the Era of High Resolution Surveys took place at the European Doctoral College(EDC) in Strasbourg from 2008 March 16 to 20. The event was co‐sponsored by the Astronomische Gesellschaft (AG) and the Société Française d'Astronomie et d'Astrophysique (SF2A), a joint venture aiming to set a new trend of regular thematic meetings in specific areas of research. This special issue of the Astronomische Nachrichten is a compilation of the papers presented at the meeting. We give an outline of the meeting together with a short history of the relations of the two societies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Complexity as a guide to understanding decision bias: A contribution to the favorite‐longshot bias debate
Authors: Sung Ming‐Chien , Johnson Johnnie Eric Victor , Dror Itiel E.
Published: November 2008

This paper investigates the origins of a widespread decision bias in betting markets, the favorite‐longshot bias (FLB); in particular, whether it is caused by cognitive errors on the part of bettors or by the pricing policies of bookmakers. The methodology is based on previous literature, which has suggested that: (i) races, as decision tasks for bettors, can be distinguished by their degree of complexity and their attractiveness to those with access to privileged information (insiders), (ii) cognitive errors increase as complexity increases, and (iii) bookmakers set odds in a manner to protect themselves from insiders. The degree of FLB was examined in races of varying complexity and attractiveness to insiders using a dataset of 8545 races drawn from the parallel bookmaker and pari‐mutuel markets operating in the UK in 2004. The results, interpreted in the light of the cognitive error and complexity literature, suggest that neither bettors' nor bookmakers' cognitive errors are the main cause of the bias. Rather, bettors' preferences for risk and the deliberate pricing policies of bookmakers play key roles in influencing the bias in markets where bookmakers and pari‐mutuel operators coexist. Copyright © 2008 John Wiley & Sons, Ltd.
Bis(amido)cyclodiphosph(III)azane Complexes of Yttrium and the Lanthanides
Authors: Rastätter Marcus , Muterle Roberto B. , Roesky Peter W. , Thiele Sven K.‐H.
Published: November 2008

The first cyclodiphosph(III)azane complexes of the rare‐earth elements have been synthesized. Reactions of the lithium salt cis‐[(tBuNP)2(tBuN)2{Li(thf)}2] with anhydrous yttrium trichloride or the heavier lanthanide trichlorides resulted in the corresponding cyclodiphosph(III)azane complexes [Li(thf)4][{(tBuNP)2(tBuN)2}LnCl2] (Ln=Y (1 a), Ho (1 b), Er (1 c)). The single‐crystal X‐ray structures showed that compounds 1 a–c consisted of ion pairs composed of a [Li(thf)4]+ cation and a C2v symmetric [{(tBuNP)2(tBuN)2}LnCl2]− anion. By treating cis‐[(tBuNP)2(tBuN)2{Li(thf)}2] with anhydrous SmCl3 in THF, the trimetallic complex [{(tBuNP)2(tBuN)2}SmCl3Li2(thf)4] (2) was obtained. The influence of the ionic radii of the lanthanides can be seen in the single‐crystal X‐ray structure of compound 2, which forms a six‐membered Cl‐Li‐Cl‐Li‐Cl‐Sm metallacycle. The ring adopts a boat conformation in which one chlorine atom and the samarium atom are displaced from the Cl2Li2 least‐square plane. Heating of the metalate complexes in toluene resulted in the extrusion of lithium chloride and the formation of the neutral dimeric metal chloride complexes of the composition [(tBuNP)2(tBuN)2LnCl(thf)]2 (Ln=Y (3 a), La (3 b) Nd (3 c), Sm (3 d)). Furthermore, treating 1 a with KNPh2 resulted in a lithium metalate complex of the composition [Li(thf)4][{(tBuNP)2(tBuN)2}Y(NPh2)2] (4). The coordination mode of the {(tBuNP)2(tBuN)2}2− ligand in 4 is different to that observed in 1 a–c, 2, and 3 a–d; instead of a symmetric η2 coordination of the ligand, a heterocubane‐type structure is observed in the solid state. The complex [(tBuNP)2(tBuN)2NdCl(thf)] (3 c) was used as a Ziegler–Natta catalyst for the polymerization of 1,3‐butadiene to poly‐cis‐1,4‐butadiene. The observed activities of the Ziegler–Natta catalyst strongly depended upon the nature of the cocatalyst; in some case very high turnover rates and a cis selectivity of 93–94 % were observed.
Crystallization Force—A Density Functional Theory Concept for Revealing Intermolecular Interactions and Molecular Packing in Organic Crystals
Authors: Li Tonglei , Ayers Paul W. , Liu Shubin , Swadley Matthew J. , Aubrey‐Medendorp Clare
Published: November 2008

Organic molecules are prone to polymorphic formation in the solid state due to the rich diversity of functional groups that results in comparable intermolecular interactions, which can be greatly affected by the selection of solvent and other crystallization conditions. Intermolecular interactions are typically weak forces, such as van der Waals and stronger short‐range ones including hydrogen bonding, that are believed to determine the packing of organic molecules during the crystal‐growth process. A different packing of the same molecules leads to the formation of a new crystal structure. To disclose the underlying causes that drive the molecule to have various packing motifs in the solid state, an electronic concept or function within the framework of conceptual density functional theory has been developed, namely, crystallization force. The concept aims to describe the local change in electronic structure as a result of the self‐assembly process of crystallization and may likely quantify the locality of intermolecular interactions that directs the molecular packing in a crystal. To assess the applicability of the concept, 5‐methyl‐2‐[(2‐nitrophenyl)amino]‐3‐thiophenecarbonitrile, so‐called ROY, which is known to have the largest number of solved polymorphs, has been examined. Electronic calculations were conducted on the seven available crystal structures as well as on the single molecule. The electronic structures were analyzed and crystallization force values were obtained. The results indicate that the crystallization forces are able to reveal intermolecular interactions in the crystals, in particular, the close contacts that are formed between molecules. Strong correlations exist between the total crystallization force and lattice energy of a crystal structure, further suggesting the underlying connection between the crystallization force and molecular packing.
Nano‐Conjugate Fluorescence Probe for the Discrimination of Phosphate and Pyrophosphate
Authors: Kim Ik‐Bum , Han Man H. , Phillips Ronnie L. , Samanta Bappaditya , Rotello Vincent M. , Zhang Z. John , Bunz Uwe H. F.
Published: November 2008

We describe a pyrophosphate (PPi) probe that is based on a fluorescent dicarboxylate‐substituted poly(para‐phenyleneethynylene) (PPE) and 10 nm cobalt–iron spinel nanoparticles (NPs) in aqueous media. The spinel NPs efficiently quench the fluorescence of the PPE at a concentration of 20–30 pmol. Addition of phosphate anions to the PPE–NP construct displaces the quenched PPE to give rise to a fluorescent response; we found that PPi and phosphate (Pi) have significantly different binding affinities for the self‐assembled materials. We can discern >40 nM PPi in the presence of 0.1 mM Pi at pH 7, which suggests that these assemblies may be useful in bio‐analytical applications. This displacement assay was used to effectively determine the ability of pyrophosphatase to hydrolyze PPi to Pi.
Self‐Assembly of Two‐Component Gels: Stoichiometric Control and Component Selection
Authors: Hirst Andrew R. , Miravet Juan F. , Escuder Beatriu , Noirez Laurence , Castelletto Valeria , Hamley Ian W. , Smith David K.
Published: November 2008

Two‐component systems capable of self‐assembling into soft gel‐phase materials are of considerable interest due to their tunability and versatility. This paper investigates two‐component gels based on a combination of a L‐lysine‐based dendron and a rigid diamine spacer (1,4‐diaminobenzene or 1,4‐diaminocyclohexane). The networked gelator was investigated using thermal measurements, circular dichroism, NMR spectroscopy and small angle neutron scattering (SANS) giving insight into the macroscopic properties, nanostructure and molecular‐scale organisation. Surprisingly, all of these techniques confirmed that irrespective of the molar ratio of the components employed, the “solid‐like” gel network always consisted of a 1:1 mixture of dendron/diamine. Additionally, the gel network was able to tolerate a significant excess of diamine in the “liquid‐like” phase before being disrupted. In the light of this observation, we investigated the ability of the gel network structure to evolve from mixtures of different aromatic diamines present in excess. We found that these two‐component gels assembled in a component‐selective manner, with the dendron preferentially recognising 1,4‐diaminobenzene (>70 %), when similar competitor diamines (1,2‐ and 1,3‐diaminobenzene) are present. Furthermore, NMR relaxation measurements demonstrated that the gel based on 1,4‐diaminobenzene was better able to form a selective ternary complex with pyrene than the gel based on 1,4‐diaminocyclohexane, indicative of controlled and selective π–π interactions within a three‐component assembly. As such, the results in this paper demonstrate how component selection processes in two‐component gel systems can control hierarchical self‐assembly.
Environmentally Friendly γ‐MnO2 Hexagon‐Based Nanoarchitectures: Structural Understanding and Their Energy‐Saving Applications
Authors: Wu Changzheng , Xie Wei , Zhang Miao , Bai Liangfei , Yang Jinlong , Xie Yi
Published: November 2008

Although about 200,000 metric tons of γ‐MnO2 are used annually worldwide for industrial applications, the γ‐MnO2 structure is still known to possess a highly ambiguous crystal lattice. To better understand the γ‐MnO2 atomic structure, hexagon‐based nanoarchitectures were successfully synthesized and used to elucidate its internal structure for the present work. The structural analysis results, obtained from the hexagon‐based nanoarchitectures, clearly show the coexistence of akhtenskite (ε‐MnO2), pyrolusite (β‐MnO2), and ramsdellite in the so‐called γ‐MnO2 phase and verified the heterogeneous phase assembly of the γ‐MnO2 state, which violates the well‐known “De Wolff” model and derivative models, but partially accords with Heuer's results. Furthermore, heterogeneous γ‐MnO2 assembly was found to be a metastable structure under hydrothermal conditions, and the individual components of the heterogeneous γ‐MnO2 system have structural similarities and a high lattice matches with pyrolusite (β‐MnO2). The as‐obtained γ‐MnO2 nanoarchitectures are nontoxic and environmentally friendly, and the application of such nanoarchitectures as support matrices successfully mitigates the common problems for phase‐change materials of inorganic salts, such as phase separation and supercooling‐effects, thereby showing prospect in energy‐saving applications in future “smart‐house” systems.
Palladium(II)‐dppe‐arylazoimidazole Complexes: Synthesis and Spectroscopic Charecterization
Authors: PRITHWIRA Byabartta
Published: November 2008

Reaction of [Pd(dppe)Cl2/Br2] with AgOTf in a dichloromethane medium followed by ligand addition led to [Pd(dppe)(OSO2CF3)2] and then [Pd(dppe)(RaaiR′)](OSO2CF3)2 [RaaiR′=p‐R‐C6H4‐NN‐C3H2‐NN‐1‐R′, (1–3), abbreviated as a N,N′‐chelator, where N(imidazole) and N(azo) are represented by N and N′, respectively; R=H (a), Me (b), Cl (c) and R′=Me (1), CH2CH3 (2), CH2Ph (3), OSO2CF3 is the triflate anion, dppe=1,2‐bis‐(diphenylphosphinoethane)]. 31P NMR confirmed that due to the two phosphorus atom interaction in the azoimine symmetrical environment one sharp peak was formed. The 1H NMR spectral measurements suggest that azo‐imine link with lot of phenyl protons in the aromatic region. 13C NMR spectrum, 1H‐1H COSY and 1H‐13C HMQC spectrum assign the solution structure and stereo‐retentive conformation in each complex.
Anatomical projections of the nuclei of the lateral lemniscus in the albino rat (rattus norvegicus)
Authors: Kelly Jack B. , van Adel Brian A. , Ito Makoto
Published: November 2008

The ascending projections to the lateral lemniscal nuclei and the inferior colliculus were investigated in the albino rat by using Fluoro‐Gold, either alone or in combination with other retrograde tract tracers. Injections were made into the central nucleus of the inferior colliculus (ICC), the dorsal nucleus of the lateral lemniscus (DNLL), the intermediate nucleus of the lateral lemniscus (INLL), or the ventral nucleus of the lateral lemniscus (VNLL). The ICC receives both ipsilateral and contralateral projections from the DNLL and the lateral superior olive, major ipsilateral projections from the INLL, VNLL, medial superior olive, and superior paraolivary nucleus, and major contralateral projections from both dorsal and ventral cochlear nucleus. The DNLL receives a similar pattern of projections from the auditory lower brainstem nuclei. The INLL, in contrast, receives its major projections from the ipsilateral VNLL, lateral superior olive, medial superior olive, superior paraolivary nucleus, and medial nucleus of the trapezoid body, but does not receive a heavy projection from the contralateral lateral superior olive. It receives a major contralateral projection from the ventral cochlear nucleus, but a much lighter projection from the contralateral dorsal cochlear nucleus. The VNLL receives projections from the ipsilateral medial nucleus of the trapezoid body and the contralateral ventral cochlear nucleus, but does not receive projections from the medial or lateral superior olives, the superior paraolivary nucleus, or the dorsal cochlear nucleus. Thus, the three primary subdivisions of the rat's lateral lemniscus can be distinguished from each other on the basis of their distinctive projection patterns. J. Comp. Neurol. 512:573–593, 2009. © 2008 Wiley‐Liss, Inc.
Multiple Phases of Liquid Water
Authors: Brovchenko Ivan , Oleinikova Alla
Published: November 2008

The history of the study of the anomalies of liquid water, from the 17th century up to the present, is reviewed and the current view on the origin of these anomalies is summarized. The hypothesis of the multiple liquid–liquid transitions of water in the supercooled region is consistent with the available experimental and simulation data and provides physical explanation of water behavior in a wide thermodynamic range. The general character of the liquid–liquid transitions of fluids is discussed and the remaining questions are formulated.
“New Methods of Statistical Economics,” revisited: Short versus long tails and Gaussian versus power‐law distributions
Authors: Mandelbrot Benoit B.
Published: November 2008

The standard “Brownian” model of competitive markets asserts that the increments of price (or of its logarithm) are statistically independent and Gaussian, implying that price itself is a continuous function of time. This model arose in 1900, at an immediately high level of perfection, in the work of L. Bachelier. In many fields of science it became a classic. But for financial prices it is sharply—even overwhelmingly—contradicted by conspicuous and strong symptoms of non‐independence, nonGaussianity, and discontinuity. Since 1963, the author has been tackling those symptoms one by one: first, by incorporating strongly non‐Gaussian marginal distributions (1963), then by incorporating strong long‐term dependence (1965), and finally by combining those two features by introducing the new notion of multifractality (1968 and since). The goal of this article is modest: largely borrowing from the author's previous articles and books, much of it collects and adapts a few brief “teasers” or “appetizers” meant to promote and assist the future development of a framework for a realistic description of actual financial fluctuations. © 2008 Wiley Periodicals, Inc. Complexity, 2009
Crystallization field study for the formation of single phase sodium clinoptilolite: Batch composition, seed and temperature effects
Authors: Güvenir Ö. , Kalıpçılar H. , Çulfaz A.
Published: November 2008

Although clinoptilolite is the most abundant zeolite mineral in nature, its synthesis under laboratory conditions has been difficult. A partial crystallization field study was done for the synthesis of clinoptilolite based on a nominal batch composition of 2.1Na2O:Al2O3:10Si2O:110H2O to delineate the limits of composition and temperature within which sodium clinoptilolite can be produced as a single phase in high yields. Effects of temperature, SiO2/Al2O3 molar ratio in the batch composition, and the use of different raw materials in batch preparation were studied. The need for the use of seed crystals for reproducible synthesis of clinoptilolite was established. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the atmosphere on the growth of LiYF4 single crystal fibers by the micro‐pulling‐down method
Authors: Maier D. , Bertram R. , Klimm D. , Fornari R.
Published: November 2008

Micro‐pulling‐down growth of LiYF4 single crystal fibers have been performed under different gas atmospheres using stoichiometric LiYF4 single crystal pieces from prior Czochralski experiments as starting material. Completely transparent and phase pure LiYF4 single crystal fibers could be obtained after evacuation of the recipient to 2×10‐6 mbar and subsequent filling with pure (99.995%) CF4 gas. Using a gas mixture of 5% CF4 in Argon or pure 5N Argon leads to the formation of micro crystallites of oxofluorides on the surface. Evacuating only to 3 × 10‐3 mbar leads, independently of atmosphere, to completely white fibers that are heavily contaminated with oxofluorides. DSC measurements of the completely transparent fiber grown under pure CF4 atmosphere reveal congruent melting behavior. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrothermal synthesis of hollow twinning ZnO microstructures
Authors: Zhao Wei , Song Xinyu , Chen Guozhu , Sun Sixiu
Published: November 2008

Two kinds of hollow twinning ZnO microstructures were synthesized through a simple hydrothermal method without additional templates or any surfactants. Dumbbell‐like and shuttle‐like ZnO microstructures with hollows were obtained by changing the materials source. The products were characterized by X‐ray power diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high‐resolution transmission electron microscopy (HRTEM). It was found that different precursors may be responsible for the formation of two different morphologies. Based on the time‐dependent experiments, we investigated the growth process of these hollow twinning structures and found the “Ostwald‐ripening process” played an important role. The interesting point of this growth process was that the interface of the two twinning structure performed as the activate center where the Ostwald‐ripening process carried out. We also investigated the luminescent properties of the as‐obtained products by photoluminescence (PL) spectroscopy. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nd(III) and Yb(III) ions incorporated in Y4Al2O9 obtained by sol‐gel method: synthesis, structure, crystals and luminescence
Authors: Lipińska L. , Rzepka A. , Ryba‐Romanowski R. , Klimm D. , Ganschow S. , Diduszko R.
Published: November 2008

The nanocrystalline powders of Y4Al2O9 (YAM) pure and doped by Nd, Yb and codoped by Nd and Yb were obtained via modified sol‐gel method. These powders were characterized by X‐ray diffraction method, scanning electron microscopy and high resolution scanning electron microscopy, luminescence spectroscopy and differential thermal analysis (DTA). We obtained single phase powders of crystalline structure with average size 70 nm exhibiting interesting luminescent properties. Efficient non‐radiative energy transfer between Nd and Yb was found. DTA confirmed the phase transition at about 1400 °C. From these nanocrystalline powders, the crystals YAM:Yb, YAM:Yb,Nd were grown by micro‐pulling down technique. They were cracking during cooling owing to the phase transition. Luminescent properties of YAM:Nd,Yb crystals were identical with properties of corresponding nanopowders within experimental incertitude. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of nano‐crystalline zeolite β: Effects of crystallization parameters
Authors: Modhera B. , Chakraborty M. , Parikh P. A. , Jasra R. V.
Published: November 2008

The effects of variation in Si/Al ratio (25 and 100) and crystallization temperature (80 °C to 180 °C, at an interval of 20 K) on crystal size of zeolite β were studied. Products obtained at different synthesis parameters were characterized by powder X‐ray diffraction, IR spectroscopy, thermal analysis, scanning electron microscopy and nitrogen adsorption. Increase in crystal size with crystallization temperature and Si/Al molar ratio was observed. Crystal morphology at 140 °C was spherical whereas at 180 °C it was of irregular shape. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel link adaptation for TETRA cellular systems
Authors: Tarchi Daniele , Fantacci Romano , Tanriover Cagri , Honary Bahram
Published: November 2008

One of the main challenges for future wireless systems is to enhance the effective data throughput by exploiting the allocated bandwidth as much as possible. Among several approaches at different layers, one of the most important is constituted by the so‐called link adaptation (LA) techniques. They are characterized by the adaptation of a set of transmission parameters to the channel state in order to improve performance. In this context, this paper is focused on the analysis of a particular class of LA techniques called adaptive modulation and coding, where the modulation and coding rate of transmission can vary according to the channel behavior. In particular, a novel LA algorithm, namely the timed window (TW) method, suitable for time‐division Duplex systems is proposed here. The performance of the TW algorithm is evaluated by taking actual user mobility conditions, communication channel behavior, as well as the physical layer effects into account. Finally, it is important to stress that, even if the wireless bearer considered in this study is TETRA (TErrestrial Trunked RAdio), the approach is quite general and it can be of interest for other wireless networks and can be optimized for different channel models (e.g. TU50, HT200, etc.). Copyright © 2008 John Wiley & Sons, Ltd.
Cytology of a sarcomatoid renal cell carcinoma with unusual coexpression of S‐100 protein: A case report, review of the literature and cytologic–histologic correlation
Authors: Gadre Swarupa A. , Math Santosh K. S. , Elfeel Khalid A. , Farghaly Hanan
Published: November 2008

Sarcomatoid renal cell carcinoma (SRCC) is an aggressive variant of renal cell carcinoma; it is an uncommon, malignant neoplasm, and its diagnosis is usually based on the histologic evaluation of a nephrectomy specimen. Patients are treated with systemic therapy and, generally, a nephrectomy is not performed. Therefore, arriving at an accurate diagnosis is critical for planning further management. Cytomorphological findings of SRCC have rarely been reported. This article reports the cytological findings in a case of SRCC composed predominantly of spindle cells and discusses its differential diagnosis in a 50‐year‐old female who presented with sharp right groin pain. A CT scan showed an enlargement of the right kidney. Cytology smears showed a malignant neoplasm composed predominantly of spindle cells. A panel of immunohistochemical stains performed on a core biopsy confirmed the epithelial nature of the spindle cells. A diffuse positive staining of the neoplastic cells for S‐100 protein was also observed. It has been reported in the medical literature that almost all SRCC cases demonstrate negative staining for S‐100 protein, with only a single case having been reported as focally positive. The cytologic differential diagnosis of spindle cell neoplasm with expression of S‐100 protein should be broadened to include SRCC. Furthermore, the S‐100 protein expression in SRCC that was observed in this case merits further investigation. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.
Essential role for the alpha 1 chain of type VIII collagen in Zebrafish notochord formation
Authors: Gansner John M. , Gitlin Jonathan D.
Published: November 2008

Several zebrafish mutants identified in large‐scale forward genetic screens exhibit notochord distortion. We now report the cloning and further characterization of one such mutant, gulliverm208 (gulm208). The notochord defect in gulm208 mutants is exacerbated under conditions of copper depletion or lysyl oxidase cuproenzyme inhibition that are without a notochord effect on wild‐type embryos. The gulm208 phenotype results from a missense mutation in the gene encoding Col8a1, a lysyl oxidase substrate, and morpholino knockdown of col8a1 recapitulates the notochord distortion observed in gulm208 mutants. Of interest, the amino acid mutated in gulm208 Col8a1 is highly conserved, and the equivalent substitution in a closely related human protein, COL10A1, causes Schmid metaphyseal chondrodysplasia. Taken together, the data identify a new protein essential for notochord morphogenesis, extend our understanding of gene–nutrient interactions in early development, and suggest that human mutations in COL8A1 may cause structural birth defects. Developmental Dynamics 237:3715–3726, 2008. © 2008 Wiley‐Liss, Inc.
Caspase‐2L, caspase‐9, and caspase‐3 during in vitro maturation and fragmentation of the mouse oocyte
Authors: Arnault Emilie , Tosca Lucie , Courtot Anne‐Marie , Doussau Mireille , Pesty Arlette , Finaz Catherine , Allemand Isabelle , Lefèvre Brigitte
Published: November 2008

Several studies have shown that apoptotic pathways control fragmentation of unfertilized ovulated oocyte, induced by doxorubicin. But very few have investigated the basis of this process, from prophase I to later stages. Our results revealed the presence of caspase‐2L, caspase‐9, and caspase‐3 in their zymogen and cleaved forms in the oocyte before meiosis resumption. Caspase‐2Land caspase‐9 were detected in the nucleus of GV‐oocytes in a distribution related to chromatin configuration. The inhibition of caspase activity by Z‐VAD‐fmk accelerated the transition from metaphase I to metaphase II, and caspase‐9 and caspase‐3 were detected along the meiotic spindle. Surprisingly, Western blot analysis revealed that the three cleaved caspases were present in similar amounts in healthy and fragmented oocytes and caspase inhibition did not prevent doxorubicin‐induced apoptosis. Our results suggest that, if cleaved, caspases may be dispensable for final oocyte death and they could be involved in regulating the maturation process. Developmental Dynamics 237:3892–3903, 2008. © 2008 Wiley‐Liss, Inc.
Spatiotemporal features of neurogenesis in the retina of medaka, Oryzias latipes
Authors: Kitambi Satish S. , Malicki Jarema J.
Published: November 2008

The vertebrate retina is very well conserved in evolution. Its structure and functional features are very similar in phyla as different as primates and teleost fish. Here, we describe the spatiotemporal characteristics of neurogenesis in the retina of a teleost, medaka, and compare them with other species, primarily the zebrafish. Several intriguing differences are observed between medaka and zebrafish. For example, photoreceptor differentiation in the medaka retina starts independently in two different areas, and at more advanced stages of differentiation, medaka and zebrafish retinae display obviously different patterns of the photoreceptor cell mosaic. Medaka and zebrafish evolutionary lineages are thought to have separated from each other 110 million years ago, and so the differences between these species are not unexpected, and may be exploited to gain insight into the architecture of developmental pathways. Importantly, this work highlights the benefits of using multiple teleost models in parallel to understand a developmental process. Developmental Dynamics 237:3870–3881, 2008. © 2008 Wiley‐Liss, Inc.
Identification and expression pattern of zebrafish prox2 during embryonic development
Authors: Pistocchi Anna , Bartesaghi Silvia , Cotelli Franco , Del Giacco Luca
Published: November 2008

Prox2, together with the previously isolated Prox1, is the vertebrate homolog of the Drosophila homeobox‐containing gene prospero, the founder member of a family of transcription factors which have been shown to play critical roles in many developmental events. We have isolated a cDNA which encodes a putative protein that shares a high degree of homology with mammalian Prox1, Prox2, and zebrafish Prox1. Comparative genomic analysis revealed that this protein corresponds to the zebrafish Prox2 homolog being the gene syntenic with the chromosome region hosting mouse Prox2. Whole‐mount in situ experiments demonstrated that prox2 is expressed, during zebrafish embryonic development, in defined structures of the central nervous system and the eye, as previously reported in mouse. Additionally, reverse transcriptase‐polymerase chain reaction analysis disclosed prox2 expression in several adult organs. Finally, prox1 loss‐ and gain‐of‐function assays have been carried out to search for regulative effects on prox2 expression. Developmental Dynamics 237:3916–3920, 2008. © 2008 Wiley‐Liss, Inc.
Protein kinase a modulates Cdc25B activity during meiotic resumption of mouse oocytes
Authors: Zhang Yang , Zhang Zhe , Xu Xiao‐Yan , Li Xue‐Song , Yu Meng , Yu Ai‐Ming , Zong Zhi‐Hong , Yu Bing‐Zhi
Published: November 2008

Protein kinase A (PKA) play a critical role in maintaining the meiotic arrest. However, the steps downstream of PKA remain largely unknown. In this study, we investigated the regulation of meiotic resumption by PKA/Cdc25B pathway in mouse oocytes. Injection of mRNA coding for Cdc25b‐S321A had a more potent maturation‐inducing ability than Cdc25b‐WT. When co‐injected with PKA inhibitor, Cdc25B‐WT had similar activities with Cdc25B‐S321A. Meanwhile, the phosphorylation of Cdc25B‐S321 was detected in germinal vesicle (GV) oocytes by Western blotting with a phospho‐Ser321‐specific antibody and the band disappeared when oocytes reenter into the meiotic cell cycle. Furthermore, Cdc25B‐WT translocated to the nucleus shortly before GV breakdown (GVBD), whereas phosphorylated Cdc25B‐S321 expressed exclusively in the cytoplasm and the signal could not be detected in GVBD oocytes. Taken together, these data indicate that Cdc25B‐Serine321 is the potential PKA target and Cdc25B subcellular localization determines its function during the process of maintaining GV arrest in mouse oocytes. Developmental Dynamics 237:3777–3786, 2008. © 2008 Wiley‐Liss, Inc.
Roscovitine inhibits thyroid hormone‐induced tail regression of the frog tadpole and reveals a role for cyclin C/Cdk8 in the establishment of the metamorphic gene expression program
Authors: Skirrow Rachel C. , Veldhoen Nik , Domanski Dominik , Helbing Caren C.
Published: November 2008

The involvement of phosphorylation signaling pathways in postembryonic development of the frog is poorly understood. The thyroid hormone, 3, 5, 3′‐triiodothyronine (T3), is essential for inducing tadpole metamorphosis and we show that the cyclin‐dependent kinase (Cdk) inhibitor, roscovitine, prevents T3‐dependent regression of cultured tail tips from Rana catesbeiana tadpoles. Using tail tips from precociously induced and naturally metamorphosing tadpoles, our data suggest that protein phosphorylation is important in the establishment of the T3‐dependent proapoptotic gene expression program. Our evidence indicates that Cdk8 is the most likely candidate for this proapoptotic activity with the expression of its regulatory subunit, cyclin C, identified as a novel T3‐responsive gene. We suggest that this activity is crucial for the genetic reprogramming required for tail regression and demonstrate that protein phosphorylation is important in T3‐induced apoptosis in normal cells during development. Developmental Dynamics 237:3787–3797, 2008. © 2008 Wiley‐Liss, Inc.
Binge eating in primary school children: Towards a definition of clinical significance
Authors: Hilbert Anja , Czaja Julia
Published: November 2008

Objective:

This study investigated the diagnostic validity of the DSM‐IV‐TR criteria for binge eating disorder as well as proposed diagnostic criteria in younger children with and without loss of control (LOC) eating.

Method:

A total of 60 children with at least one episode of loss of control over eating within the past 3 months and 60 matched children without LOC history were recruited from the community. Clinical interviews and self‐report questionnaires were used to assess psychopathology.

Results:

Hierarchical cluster analyses produced clusters of high recurrent LOC eating, low recurrent LOC eating, and no or sporadic LOC eating. The children with high recurrent LOC eating had eating disorder and general psychopathology comparable to that documented in clinical eating disorders. The DSM‐IV‐TR criteria and the criterion of “undue influence of weight or shape on self‐evaluation” could at lower thresholds than for adults be used to identify children with high recurrent LOC eating.

Discussion:

Overall, this evaluation of the diagnostic validity of binge eating disorder in middle childhood suggests that only a few modifications to the adult DSM‐IV‐TR criteria are necessary to identify children with LOC eating suffering from clinically significant eating disorder psychopathology and increased general psychopathology. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2009
Molecular Motion and Performance Enhancement of BORAZAN Fluorescent Dyes
Authors: Morin Tyler J. , Lindeman Sergey V. , Gardinier James R.
Published: November 2008

The preparation of three 2,6‐dipyrazolyl‐4‐X‐anilines, H(pz2AnX) (X = p‐CF3, Cl, tBu) using CuI‐catalyzed amination is described. Subsequent reactions of H(pz2AnX) with triphenylboron proceeds with benzene elimination to give the corresponding Ph2B(pz2AnX) compounds in high yields. The Ph2B(pz2AnX) are more highly emissive in the solid state than the previously reported BORAZAN fluorophores, Ph2B(pzAnX), their monopyrazolyl counterparts. As with the Ph2B(pzAnX), the color of emission in Ph2B(pz2AnX) can be tuned simply by varying the para‐aniline substituent where the emission of Ph2B(pz2AnX) is red‐shifted relative to the corresponding Ph2B(pzAnX) derivatives. The electronic properties were studied by cyclic voltammetry and electronic absorption/emission spectroscopy as well as by density functional calculations (B3LYP/6‐31G*). The di‐pyrazolyl derivatives exhibit greater stability toward solvolysis and higher photoluminescent quantum yields (despite the red‐shift in emission) compared to their monopyrazolyl counterparts presumably due to kinetic stabilization of the chromophore imparted by the second pyrazolyl ligand. For Ph2B(pz2AnX), evidence for intramolecular motion of the diphenylboryl moiety traversing both pyrazolyl groups was detected by variable temperature 1H NMR spectroscopy. The rate increases with increasing electron‐donor abilities of the para‐aniline substituent.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis and Structure of an Unprecedented Linear Pentanuclear Bismuth(III) Zwitterionic Thiolate Complex
Authors: Chen Jin‐Xiang , Tang Xiao‐Yan , Ren Zhi‐Gang , Zhang Yong , Lang Jian‐Ping
Published: November 2008

A unique pentanuclear bismuth(III) zwitterionic thiolate complex, [Bi5(Tab)18](PF6)7(NO3)8]·6MeCN [1; Tab = 4‐(trimethylammonio)benzenethiolato], was obtained from the reaction of Bi(NO3)3 with TabHPF6 in a 1:4 molar ratio in MeCN/MeOH in the presence of Et3N and structurally characterized. Single‐crystal X‐ray diffraction revealed that 1 consists of an unprecedented linear [Bi5(Tab)18]15+ cation, and both [PF6]– and [NO3]– anions in the crystal cooperatively work as anionic templates to form interesting anionic honeycomb‐like cavities for encapsulating the [Bi5(Tab)18]15+cations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Enantioselective Binaphthophosphepine‐Promoted [3+2] Annulations of N‐Ts‐ and N‐DPP‐Imines with Allenoates and 2‐Butynoates
Authors: Pinto Nathalie , Fleury‐Brégeot Nicolas , Marinetti Angela
Published: November 2008

The use of binaphthophosphepine 1a as a catalyst for the [3+2] cyclisation between allenoates or 2‐butynoates andimines was investigated. The effects of the imine protecting group on both the catalytic activity and enantioselectivity were determined by comparing the behaviour of N‐tosyl‐ and N‐DPP‐imines. The N‐DPP‐imines displayed lower reactivity, but afforded the desired pyrrolines in higher enantiomeric excess (73–92 % ee). The DPP protecting group was removed from the final pyrrolines under mild conditions to afford the corresponding secondary amines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)