bluuebunny/crossref_metadata_2025_split huggingface dataset:
A posteriori error estimation for extended finite elements by an extended global recovery
Authors: Duflot Marc , Bordas Stéphane 
Published: October 2008

AbstractThis contribution presents an extended global derivative recovery for enriched finite element methods (FEMs), such as the extended FEM along with an associated error indicator. Owing to its simplicity, the proposed scheme is ideally suited to industrial applications. The procedure is based on global minimization of the L2 norm of the difference between the raw strain field (C−1) and the recovered (C0) strain field. The methodology engineered in this paper extends the ideas of Oden and Brauchli (Int. J. Numer. Meth. Engng 1971; 3) and Hinton and Campbell (Int. J. Numer. Meth. Engng 1974; 8) by enriching the approximation used for the construction of the recovered derivatives (strains) with the gradients of the functions employed to enrich the approximation employed for the primal unknown (displacements). We show linear elastic fracture mechanics examples, both in simple two‐dimensional settings, and for a three‐dimensional structure. Numerically, we show that the effectivity index of the proposed indicator converges to unity upon mesh refinement. Consequently, the approximate error converges to the exact error, indicating that the error indicator is valid.Additionally, the numerical examples suggest a novel adaptive strategy for enriched approximations in which the dimensions of the enrichment zone are first increased, before standard h‐ and p‐adaptivities are applied; we suggest to coin this methodology e‐adaptivity. Copyright © 2008 John Wiley & Sons, Ltd.
ℋ︁∞ control of discrete‐time Markov jump systems with bounded transition probabilities
Authors: Boukas E. K. 
Published: October 2008

AbstractThis paper deals with the class of discrete‐time linear systems with random abrupt changes and unknown transition probabilities but varying between known bounds for each mode. The ℋ︁∞ control problem of this class of systems is revisited and new sufficient conditions are developed in the linear matrix inequality (LMI) setting to design the state‐feedback controller that stochastically stabilizes the system under consideration and at the same time guarantees the disturbance rejection with a desired level γ . Sufficient conditions for existence of the state‐feedback controller are developed. It is shown that the addressed problem can be solved if the corresponding developed LMIs are feasible. Numerical examples are employed to show the usefulness of the proposed results. Copyright © 2008 John Wiley & Sons, Ltd.
Why are MSCs therapeutic? New data: new insight
Authors: Caplan AI 
Published: October 2008

AbstractAdult marrow‐derived mesenchymal stem cells (MSCs) are able to differentiate into bone, cartilage, muscle, marrow stroma, tendon–ligament, fat and other connective tissues. The questions can be asked, what do MSCs do naturally and where is the MSC niche? New insight and clinical experience suggest that MSCs are naturally found as perivascular cells, summarily referred to as pericytes, which are released at sites of injury, where they secrete large quantities of bioactive factors that are both immunomodulatory and trophic. The trophic activity inhibits ischaemia‐caused apoptosis and scarring while stimulating angiogenesis and the mitosis of tissue intrinsic progenitor cells. The immunomodulation inhibits lymphocyte surveillance of the injured tissue, thus preventing autoimmunity, and allows allogeneic MSCs to be used in a variety of clinical situations. Thus, a new, enlightened era of experimentation and clinical trials has been initiated with xenogenic and allogeneic MSCs. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Hypophosphatasia: molecular testing of 19 prenatal cases and discussion about genetic counseling
Authors: Simon‐Bouy Brigitte , Taillandier Agnès , Fauvert Delphine , Brun‐Heath Isabelle , Serre Jean‐Louis , Armengod Carmen G. , Bialer Martin G. , Mathieu Michèle , Cousin Jacques , Chitayat David , Liebelt Jan , Feldman Barbara , Gérard‐Blanluet Marion , Körtge‐Jung Stefani , King Cath , Laivuori Hannele , Le Merrer Martine , Mehta Sarju , Jern Christina , Sharif Saba , Prieur Fabienne , Gillessen‐Kaesbach Gabriele , Zankl Andreas , Mornet Etienne 
Published: October 2008

AbstractObjectiveWe studied hypophosphatasia (HP) mutations in 19 cases prenatally detected by ultrasonography without familial history of HP. We correlated the mutations with the reported ultrasound signs, and discussed genetic counseling with regard to the particular dominantly inherited prenatal benign form of HP.MethodThe coding sequence of the tissue nonspecific alkaline phosphatase (TNSALP) gene was analyzed by DNA sequencing, and 3D modeling was used to locate the mutated amino acids with regard to the functional domains of TNSALP.ResultsAlthough reported ultrasound signs were heterogeneous, two mutated alleles were found in 18 of the 19 cases studied, indicating recessive transmission of the disease. Functional domains of TNSALP were affected by 74% of missense mutations. In all the cases, including one with only a heterozygous mutation, molecular, biological, and familial data do not corroborate the hypothesis of prenatal benign HP. The mutation c.1133A > T observed in the prenatal benign form of HP and common in USA was not found in this series.ConclusionThe results point out the prenatally detectable allelic heterogeneity of HP. The nature of the detected mutations and the evidence of recessive inheritance do not support these cases being affected with prenatal benign HP. Copyright © 2008 John Wiley & Sons, Ltd.
Reversible photo‐induced spectral change and defect creation in ZrO2
Authors: Fujishiro Fumito , Mochizuki Shosuke 
Published: October 2008

AbstractWhen ZrO2 films and nanocrystals are irradiated with a 325 nm laser light in an evacuated chamber, each luminescence‐intensity increases, creating a broad visible luminescence. Then, introducing O2 gas into the specimen chamber, the photoluminescence spectrum returns reversibly to the original luminescence under the same laser light irradiation. After removing the laser light, each luminescence state is stored for a long time at room temperature under room light, regardless of any changes of atmosphere. The observed phenomena are explained by means of the photo‐induced oxygen defect creation and annihilation at/near the ZrO2 surface. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependence of intra‐chain photoluminescence of a long oligothiophene
Authors: Kanemoto Katsuichi , Akai Ichiro , Hashimoto Hideki , Karasawa Tsutomu , Negishi Nobukazu , Aso Yoshio 
Published: October 2008

AbstractThe temperature dependence (4 K‐300 K) of the photoluminescence (PL) and absorption spectra of 16‐mer oligothiophene (16T) diluted in polypropylene (PP) with a weight ratio of 1/30000 has been investigated in order to clarify the intrinsic temperature effect on conjugated polymers with negligible interchain interaction. The PL and absorption spectra are found to blueshift with increasing temperature. Simple model calculations suggest that the effective conjugation length of 16T is reduced to the two‐third of the original chain length at room temperature. The magnitude of Stokes shift of 16T increases with increasing temperature. The steady‐state PL spectra can be well reproduced by spectral fitting based on Franck‐Condon analysis using a single Huang‐Rhys (HR) factor over the wide temperature range of the measurement. This analysis demonstrates the temperature dependence of HR factor in PL. The HR factor in PL is found to decrease with increasing temperature, whereas that of the absorption spectra increases with temperature. This observation can be explained by assuming that the lowest energy conformer of 16T is responsible for PL and such a conformer has smaller coupling with phonons. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarization memory effect on nonlinear photoluminescence of semimagnetic semiconductor Cd0.8Mn0.2Te
Authors: Katayama Kouichi , Miyajima Kensuke , Ashida Masaaki , Itoh Tadashi 
Published: October 2008

AbstractPolarization memory effect was found in the nonlinear photoluminescence band (hereinafter referred to as the X band) of semimagnetic semiconductor Cd0.8Mn0.2Te. The X band appears only when high‐density selective excitation of localized exciton has done. The origin of the X band is proposed as the high‐spin state of the dense magnetic polarons: in this state, every spins of electrons (holes) point one direction and this spin alignment leads to enhanced magnetic polaron effect. The inclusion of linearly polarized component of the X band, which is excited by the linearly polarized excitation laser, is confirmed from the analyzer dependence of the intensity of the X band. The characteristic oscillatory structure of the X band under magnetic field was explained by Faraday rotation of the X band and the structure is reproduced with supposition of step function like absorption. Polarization memory effect of the X band is confirmed by the behavior of the peak energy of the oscillatory structure; the structure varies with tilt of the polarization plane of the excitation laser. The polarization memory effect of the X band most likely originates from the sufficiently long phase relaxation time of the photoexcited electrons and holes of the X band. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parametric interactions and nonlinear Raman processes of vibronic excitons in polydiacetylene studied with a two‐optical‐cycle laser
Authors: Kobayashi Takayoshi , Iwakura Izumi , Yabushita Atsushi 
Published: October 2008

AbstractSum and difference frequency mixing, which are the analogues of the second‐order nonlinear optical processes were for the first time found in vibronic exciton systems under high‐density excitations. Cascaded nonlinear Raman scattering was for the first time observed in the exciton system of PDA. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Translation of semiclassical optical‐response theory into quantum‐optics theory
Authors: Koshino Kazuki 
Published: October 2008

AbstractIn order to analyze the dynamics of single photons, a full‐quantum analysis is indispensable in principle, where both the photon field and the material system are treated quantum‐mechanically. However, the semiclassical optical response theory can be utilized to infer the photon dynamics, bypassing the full‐quantum analyses. This fact is demonstrated for a concrete problem of evaluation of the Kerr effect appearing in two photons. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
THz quantum optics with dark excitons in Cu2O: from stimulated emission to nonlinear population control
Authors: Leinß S. , Kampfrath T. , Volkmann K. v. , Schmid B. A. , Fröhlich D. , Wolf M. , Kaindl R. A. , Leitenstorfer A. , Huber R. 
Published: October 2008

AbstractFundamental quantum optical processes in photogenerated excitons in Cu2O are demonstrated using few‐cycle terahertz pulses and field‐sensitive electro‐optic sampling: (i) In a dilute ensemble of 3p excitons, stimulated terahertz emission from internal transitions to the energetically lower 2s state is observed at a photon energy of 6.6 meV, with a cross section of 10‐14 cm2. (ii) An optically dark, dense, and cold 1s‐paraexciton gas is prepared by two‐photon generation of electron‐hole pairs and subsequent phonon cooling. Intense multi‐terahertz fields of order MV/cm coherently promote 70% of the quasiparticles from the 1s to the 2p state via a partial internal Rabi oscillation. Electro‐optic detection monitors the Larmor precession of the Bloch vector directly in the time domain, with femtosecond resolution. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Trap state emission of water‐soluble CdS nanocrystals
Authors: Lü W. , Tokuhiro Y. , Umezu I. , Sugimura A. , Nagasaki Y. 
Published: October 2008

AbstractWe prepared water‐soluble CdS nanocrystals (NCs) capped by the poly (ethylene glycol)‐b‐poly (2‐(N,N ‐dimethylamino)ethyl methacrylate) chain. The photoluminescence (PL) properties of CdS NCs are investigated by time‐resolved and temperature‐dependent PL spectra. It is found that the PL band of CdS NCs is dominated by two trap state emissions, respectively. Due to the trap state emissions, fluorescent resonance energy transfer from CdS NCs to organic dyes (Texasred) can be observed, which suggests the potential application of trap states of CdS NCs for fabrication of biosensors. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin orientation of excitons, trions and tetraons in charge tunable InP quantum dots
Authors: Masumoto Yasuaki , Suzuki Tsukasa , Kawana Keisuke , Ikezawa Michio 
Published: October 2008

AbstractIn the longitudinal magnetic field, photoluminescence (PL) polarization in InP quantum dots (QDs) dramatically changed depending on the number of doped electrons. Under linearly polarized excitation, PL polarizes resonantly at two magnetic fields where bright and dark excitons anticross each other in neutral QDs. On the other hand, PL polarization monotonously increases with the increase of longitudinal magnetic field in one‐ and two‐electron doped QDs, where thermal spin orientation of a photoexcited hole determines the PL polarization of a trion and a tetraon. At low temperatures, however, the electron‐hole exchange interaction reduces the thermal spin orientation of holes. In two‐electron doped QDs, the anisotropic electron‐hole exchange interaction gives small structure in the magnetic‐field‐dependent circular polarization at the low field region. Time‐resolved circular polarization clearly shows the dynamical spin polarization process in charged QDs in the longitudinal magnetic field. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extremely long electron spin coherence induced by a trion transition in ZnSe/BeTe type‐II quantum wells
Authors: Mino H. , Kouno Y. , Oto K. , Muro K. , Akimoto R. , Takeyama S. 
Published: October 2008

AbstractThe spin coherence of photoexcited electrons in non‐doped ZnSe/BeTe type‐II quantum wells was investigated by a time‐resolved Kerr rotation (TRKR) technique using resonant excitation of either excitons or negatively charged excitons (trions) in magnetic fields at 1.4 K. The TRKR signal arising from the Lamor precession of photo‐excited electron spins in ZnSe layers was observed and enhanced at the trion resonance, where the spin relaxation time reached up to several nanoseconds. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic‐field induced mixing of singlet and triplet excitons confined in CuCl quantum dots
Authors: Miyajima Kensuke , Umemura Yuna , Katayama Kouichi , Ashida Masaaki , Itoh Tadashi 
Published: October 2008

AbstractPhotoluminescence spectra of CuCl quantum dots and their corresponding decay times have been measured under an external magnetic field in Voigt geometry. Magnetic‐field induced mixing between the singlet and triplet excitons was evaluated by studying the magnetic field dependencies of their decay times. A bound exciton shows a larger degree of mixing than that of a free exciton. In addition, the degree of mixing of the bound exciton increases on decreasing the dot size. It is suggested that the enhancement in the degree of mixing is induced by an increase in the value in the exciton g‐factor due to the symmetry breaking of the wavefunction of the bound exciton. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis, characterization, and its PL dynamics of colloidal type II CdTe/CdSe nanocrystals
Authors: Oda Masaru , Nishiyama Akira , Marumo Gi‐ichi , Yamada Shuhei , Tanaka Erina , Tani Toshiro 
Published: October 2008

AbstractWe describe our improved synthesis and optical properties of high quality type II CdTe/CdSe nanocrystals (NCs). Specifically, clear shell‐thickness dependences have been observed in the absorption and photoluminescence (PL) spectra and PL decay profiles as well. The magnitude of the lowest absorption band decreases drastically with large redshift as the shell thickness increases. The origin will be discussed on the bases of the model where the spatial configuration of the lowest electron‐hole pair in the NCs changes from that of type I to type II as the shell thickness increases. As for the PL lifetime of the lowest electron‐hole excitations, substantial increase is observed with increasing shell thickness. This can also be understood by considering the spatial configuration; spatial overlap between electron and hole wavefunctions decreases with increasing shell thickness, thus the lifetime increases. As for the NCs with extremely thin shell (∼1 ML; 1 ML = 0.35 nm), the PL lifetime seems much longer than expected. This suggests that the thin shells seem imperfect and work rather a kind of trap sites than layers. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Are the Chemical Structures in Your QSAR Correct?
Authors: Young Douglas , Martin Todd , Venkatapathy Raghuraman , Harten Paul 
Published: October 2008

AbstractQuantitative structure–activity relationships (QSARs) are used to predict many different endpoints, utilize hundreds, and even thousands of different parameters (or descriptors), and are created using a variety of approaches. The one thing they all have in common is the assumption that the chemical structures used are correct. This research investigates this assumption by examining six public and private databases that contain structural information for chemicals. Molecular fingerprinting techniques are used to determine the error rates for structures in each of the databases. It was observed that the databases had error rates ranging from 0.1 to 3.4%. A case study to predict the n‐octanol/water partition coefficient was also investigated to highlight the effects of these errors in the predictions of QSARs. In this case study, QSARs were developed using both (i) all correct structures and (ii) structures from a database with an error rate of 3.4%. This case study showed how slight errors in chemical structures, such as misplacing a Cl atom or swapping hydroxy and methoxy functional groups on a multiple ring structure, can result in significant differences in the accuracy of the prediction for those chemicals.
Protein secondary structure class assignment on the basis of a new graphic representation
Authors: Jia Cangzhi , Liu Tian , Zhang Xiangde , Yan Shijun 
Published: October 2008

AbstractA novel 2D representation (M‐curve) has been provided to visualize the structure information of protein secondary structure sequences: (1) end point of the curve reflects difference of amino acid residue numbers in α‐helices and β‐strands of a protein; (2) Up/down ladder‐like structures in the curve show that α‐helices/β‐strands appear sequentially in this region; (3) triangular‐like/trapeziform‐like structures of the curve show that α‐helices and β‐strands appear alternatively in this region. So from the M‐curve, a protein could be directly assigned into corresponding secondary structure class. Moreover, a new numerical descriptor, four‐component vector, is introduced and applied to cluster analysis. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Integrated approach to PCE‐impacted site characterization, site management, and enhanced bioremediation
Authors: Davis Greg , Baldwin Brett R. , Peacock Aaron D. , Ogles Dora , White Glenn M. , Boyle Susan L. , Raes Eric , Koenigsberg Stephen S. , Sublette Kerry L. 
Published: October 2008

AbstractTetrachloroethene (PCE)‐ and trichloroethene (TCE)‐impacted sites pose significant challenges even when site characterization activities indicate that biodegradation has occurred naturally. Although site‐specific, regulatory, and economic factors play roles in the remedy‐selection process, the application of molecular biological tools to the bioremediation field has streamlined the assessment of remedial alternatives and allowed for detailed evaluation of the chosen remedial technology. The case study described here was performed at a PCE‐impacted site at which reductive dechlorination of PCE and TCE had led to accumulation of cis‐dichlorethene (cis‐DCE) with concentrations ranging from approximately 10 to 100 mg/L. Bio‐Trap® samplers and quantitative polymerase chain reaction (qPCR) enumeration of Dehalococcoides spp. were used to evaluate three remedial options: monitored natural attenuation, biostimulation with HRC®, and biostimulation with HRC‐S®. Dehalococcoides populations in HRC‐S‐amended Bio‐Traps deployed in impacted wells were on the order of 103 to 104 cells/bead but were below detection limits in most unamended and HRC‐amended Bio‐Traps. Thus the in situ Bio‐Trap study identified biostimulation with HRC‐S as the recommended approach, which was further evaluated with a pilot study. After the pilot HRC‐S injection, Dehalococcoides populations increased to 106 to 107 cells/bead, and concentrations of cis‐DCE and vinyl chloride decreased with concurrent ethene production. Based on these results, a full‐scale HRC‐S injection was designed and implemented at the site. As with the pilot study, full‐scale HRC‐S injection promoted growth of Dehalococcoides spp. and stimulated reductive dechlorination of the daughter products cis‐DCE and vinyl chloride. © 2008 Wiley Periodicals, Inc.
Early security key exchange for encryption in Mobile IPv6 handoff
Authors: Wu Tin‐Yu , Lo Chi‐Hsiang , Chao Han‐Chieh 
Published: October 2008

AbstractWireless equipment has become ubiquitous. However, in facing various software attacks, wireless linked networks are more vulnerable than wire linked networks. The general problem with Mobile IPv6 (MIPv6) (Table I) is the long handover latency period. To reduce the security latency, we propose early security key exchange for encryption in MIPv6 handoff. In our approach, two issues are addressed in dealing with the latency within the encryption technology during the handover. First, we extend the Early Binding Update (EBU) method to deal with the long security exchange negotiation time for the MIPv6 handoff. Second, we adopt the Security Access Gateway (SAG) to solve the limited computing and memory in the Mobile Node (MN). Copyright © 2008 John Wiley & Sons, Ltd.
Social problem solving in chronic fatigue syndrome: preliminary findings
Authors: Christopher Gary , Thomas Marie 
Published: October 2008

AbstractThis paper investigates social problem solving in chronic fatigue syndrome (CFS), a condition characterized by reduced activity levels and excessive mental fatigue. Although intra‐ and inter‐personal problems are prevalent, no studies have explored social problem‐solving skills in this group. Patients were split into two groups: either high or low alexithymia, a condition associated with affect dysregulation. The high alexithymic group viewed problems as threatening, responding either impulsively or avoiding responding altogether; they were poor also in the use of compensatory strategies, which, taken together, increases the likelihood of a negative outcome from attempts at conflict resolution. These findings go some way in successfully identifying potential subgroupings in CFS sufferers and has important implications in terms of the therapy offered. Copyright © 2008 John Wiley & Sons, Ltd.