bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical and functional interactions between the human DNMT3L protein and members of the de novo methyltransferase family
Authors: Chen Zhao‐Xia , Mann Jeffrey R. , Hsieh Chih‐Lin , Riggs Arthur D. , Chédin Frédéric 
Published: April 2005

AbstractThe de novo methyltransferase‐like protein, DNMT3L, is required for methylation of imprinted genes in germ cells. Although enzymatically inactive, human DNMT3L was shown to act as a general stimulatory factor for de novo methylation by murine Dnmt3a. Several isoforms of DNMT3A and DNMT3B with development‐stage and tissue‐specific expression patterns have been described in mouse and human, thus bringing into question the identity of the physiological partner(s) for stimulation by DNMT3L. Here, we used an episome‐based in vivo methyltransferase assay to systematically analyze five isoforms of human DNMT3A and DNMT3B for activity and stimulation by human DNMT3L. Our results show that human DNMT3A, DNMT3A2, DNMT3B1, and DNMT3B2 are catalytically competent, while DNMT3B3 is inactive in our assay. We also report that the activity of all four active isoforms is significantly increased upon co‐expression with DNMT3L, albeit to varying extents. This is the first comprehensive description of the in vivo activities of the poorly characterized human DNMT3A and DNMT3B isoforms and of their functional interactions with DNMT3L. To further elucidate the mechanism by which DNMT3L stimulates DNA methylation, we have mapped in detail the domains that mediate interaction of human DNMT3L with human DNMT3A and DNMT3B. Our results show that the C‐terminus of DNMT3L is the only region required for interaction with DNMT3A and DNMT3B and that interaction takes place through the C‐terminal catalytic domain of DNMT3A and DNMT3B. The implications of these findings for the regulation of de novo methyltransferases and genomic imprinting are discussed. This article contains Supplementary Material available at http://www.mrw.interscience.wiley.com/suppmat/0730‐2312/suppmat/2005/95/chen.html. © 2005 Wiley‐Liss, Inc.
Induction of an epithelial to mesenchymal transition in human immortal and malignant keratinocytes by TGF‐β1 involves MAPK, Smad and AP‐1 signalling pathways
Authors: Davies Maria , Robinson Max , Smith Emily , Huntley Suzy , Prime Stephen , Paterson Ian 
Published: April 2005

AbstractRecent data indicate that transforming growth factor‐β1 (TGF‐β1) can act to promote tumour progression in the late stages of carcinogenesis. The mechanism by which this occurs is unknown although a ligand‐induced epithelial–mesenchymal transition (EMT) is thought to be important. In this study, we demonstrate that active Ras is required for TGF‐β1‐induced EMT in human keratinocytes and that epidermal growth factor (EGF) can substitute for mutant Ras. EMT was reversed by the removal of TGF‐β1. Under conditions of TGF‐β1‐induced EMT, cells were growth inhibited by the ligand resulting in G1 arrest. In cells containing normal Ras, TGF‐β1‐activated ERK and p38 mitogen‐activated protein kinases (MAPKs), and levels of activation were further increased by co‐treatment with EGF. Inhibition of MAPK pathways and Smad2/3 signalling blocked the induction of EMT by TGF‐β1. Further, inhibition of the AP‐1 transcriptional complex by [6]‐Gingerol, or by the ectopic expression of JDP2, blocked TGF‐β1‐induced EMT and conversely, stimulation of AP‐1 by 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) substituted for EGF in the induction of EMT by TGF‐β1 in cells containing normal Ras. The presence of oncogenic Ras, the treatment of cells with EGF, or the treatment of cells with TPA to activate AP‐1, potentiated TGF‐β1‐induced Smad‐dependent transcription, an effect that was attenuated by the inhibition of MAPKs and AP‐1. The results demonstrate that active Ras and TGF‐β1 co‐operate to reversibly induce EMT in human keratinocytes by mechanisms that involve MAPKs, Smad2/3 and AP‐1. Further we demonstrate that MAPK/AP‐1 signalling enhances Smad transcriptional activity under conditions associated with TGF‐β1‐induced EMT. © 2005 Wiley‐Liss, Inc.
Distribution of Substituents along the Cellulose Chain on Cellulose Xanthate and Carboxymethyl Cellulose
Authors: Fischer Klaus , Krasselt Karsten , Schmidt Ingeborg , Weightman Derek 
Published: April 2005

AbstractThe distribution of substituents of cellulose xanthogenate and carboxymethyl cellulose along the cellulose chains and therefore in relation to the molecular mass can be measured using size exclusion chromatography including a multi angle laser light scattering and mass detection for determining the molecular mass of the derivative assisted by an UV‐ detection for determining the xanthate groups and carboxymethyl groups after derivatisation, respectively. The results investigating cellulose xanthogenate show that the temperature used in dissolving xanthogenate and in ripening viscose influences the distribution of xanthate groups in a different way; but all steps processing viscose are connected with a loss in the degree of substitution in ripening the distribution of substitution additionally becomes more even.The investigated carboxymethyl cellulose revealed different distribution of carboxylic groups in dependence on the viscosity of the CMC.
A Novel Method for Analysis of Xanthate Group Distribution in Viscoses
Authors: Rußler Axel , Lange Thomas , Potthast Antje , Rosenau Thomas , Berger‐Nicoletti Elena , Sixta Herbert , Kosma Paul 
Published: April 2005

AbstractAnalytical monitoring of xanthation in the viscose process along with xanthate group analysis in the viscose material is a long‐debated problem in cellulose chemistry. The task is rendered extremely intricate by the lability of the starting material and the harshness of the reaction medium, which adds to a lack of suitable analytical approaches. In a four‐years' endeavor in our lab, a method is being developed which allows to analyze the distribution of xanthate groups in viscoses relative to the anhydroglucose units and along the cellulose chain.In a first step the xanthate groups are stabilized by alkylation, which was optimized towards quantitative conversion. In a second step, the remaining free hydroxyl groups are protected by carbanilation, followed by selective removal of the stabilized xanthate groups. Steps two and three thus generate an inverse image of the initial xanthate pattern. In the forth and fifth step, the liberated hydroxyl groups are methylated, and the carbanilates are removed, so that in the overall process the xanthates were replaced by methyl groups. All reaction steps have been comprehensively tested with regard to completeness of conversion and orthogonality of the protecting groups.
Prehydrolysis Sulfite Revisited
Authors: Fasching Mario , Griebl Andreas , Kandioller Gottfried , Zieher Andrea , Weber Hedda , Sixta Herbert 
Published: April 2005

AbstractThe prehydrolysis of beech wood in water at different temperatures and the impact of this treatment on further pulping stages were explored. Both, increased condensation degree and an increased number of free phenolic hydroxyl groups were found in the lignin isolated after prehydrolysis. An intermediate alkaline extraction (using either NaOH or MgO as base) following the prehydrolysis was explored. Finally, acid sulfite cooks of the differently pre‐treated materials were performed, and the obtained materials thoroughly analyzed.
Complexes of diphenylarsinic acid and phenylarsonic acid with thiols: a 1H and 13C NMR study
Authors: Nakayama Takashi , Isobe Tomohiko , Nakamiya Kunichika , Edmonds John S. , Shibata Yasuyuki , Morita Masatoshi 
Published: April 2005

AbstractThe high toxicity of diphenylarsinic acid, found in ground water and well water as a probable consequence of the inappropriate disposal of warfare agents, prompted us to study the reaction, monitored by 1H and 13C NMR spectroscopy, of the compound and its monophenyl analogue, phenylarsonic acid, with cellular thiols as represented, in particular, by glutathione. Glutathione reduced the phenylarsenic acids to trivalent forms and complexed them: diphenylarsinic acid to a monoglutathione adduct and phenylarsonic acid to a diglutathione adduct. The complexes were characterized by 1H and 13C NMR spectroscopy and mass spectrometry. The NMR spectra showed the diastereotopic nature of the two phenyl groups in the diphenylarsinic acid–glutathione compound, and of the two glutathione residues in the phenylarsonic acid–diglutathione complex. The stereochemistry of thiol compounds of phenylarsonic acid was further explored by 1H and 13C NMR spectroscopy of the L‐cysteine complex. The diphenylarsinic acid–glutathione complex was stable below pH 12 but at higher pH the complex dissociated into diphenylarsinous acid and reduced glutathione. The released diphenylarsinous acid then oxidized to diphenylarsinic acid with a half‐life of about 7 h at pH 13 and at room temperature. Copyright © 2005 John Wiley & Sons, Ltd.
Ring‐substituted benzohydroxamic acids: 1H, 13C and 15N NMR spectra and NHOH proton exchange
Authors: Schraml Jan , Tkadlecová Marcela , Pataridis Statis , Soukupová Ludmila , Blechta Vratislav , Roithová Jana , Exner Otto 
Published: April 2005

AbstractNMR spectra (1H, 13C, 15N) of para‐ and meta‐substituted benzohydroxamic acids were studied in dry dimethyl sulfoxide solutions. The 13C chemical shifts were very close to those found by cross‐polarization magic angle spinning in solids, the hydroxamic (not hydroximic) structure of which is unambiguous. The hydroxamic structure of these acids in DMSO solutions was proved independently by their 15N chemical shifts. The 15N and 1H chemical shifts of the NHOH fragment showed excellent mutual dependences and dependences on the nature of the ring substituent. According to these dependences and ab initio energy calculations, all the acids assume the same Z conformation. Proton exchange between hydroxamic OH and NH groups in DMSO proceeded by both intra‐ and intermolecular exchange and the rates did not exhibit any simple relationship to the substituent constants. Copyright © 2005 John Wiley & Sons, Ltd.
Spikes in two coupled nonlinear Schrödinger equations
Authors: Lin Tai-Chia , Wei Juncheng 
Published: April 2005

Here we study the interaction and the configuration of spikes in a double condensate by analyzing least energy solutions of two coupled nonlinear Schrödinger equations which model Bose–Einstein condensates of two different hyperfine spin states. When the interspecies scattering length is positive and large enough, spikes of a double condensate repel each other and behave like two separate spikes. In contrast, spikes of a double condensate attract each other and behave like a single spike if the interspecies scattering length is negative and large enough. Our mathematical arguments can prove such physical phenomena. We first use Nehari's manifold to construct least energy solutions, and then use some techniques of singular perturbation problems to derive the asymptotic behavior of least energy solutions. It is shown that the interaction term determines the locations of the two spikes and the asymptotic shape of least energy solutions.

Résumé
Nous étudions l'interaction et la disposition des pics pour un condensat double. Notre méthode utilise l'analyse des solutions avec énergie minimale des deux équations de Schrödinger couplées non linéaires qui modèlent le condensat de Bose et Einstein pour deux états des spins différents hyperfinis. Si la longueur de dispersion entre espèces est positive et suffisamment gande, les pics pour un condensat double se repoussent, et se comportent comme deux pics séparés. En revanche pour un condensat double s'attirent et se comportent comme un seul pic ; la longueur de dispersion entre espèces est négative et suffisamment petite. Nos arguments mathématiques établissent rigoureusement ses phénomènes physiques. Nous utilisons d'une part la variété de Nehari pour la construction de solutions avec énergie minimale et d'autre part les techniques de problèmes de perturbation singulière pour la dérivation du comportement asymptotique de la solutions avec énergie minimale. Nous démontrons que le terme d'interaction détermine la position des pics et la forme asymptotique des solutions avec énergie minimale.
The multi-dimensional super-replication problem under gamma constraints
Authors: Soner H. Mete , Touzi Nizar , Cheridito Patrick 
Published: April 2005

The classical Black–Scholes hedging strategy of a European contingent claim may require rapid changes in the replicating portfolio. One approach to avoid this is to impose
a priori
bounds on the variations of the allowed trading strategies, called gamma constraints. Under such a restriction, it is in general no longer possible to replicate a European contingent claim, and super-replication is a commonly used alternative. This paper characterizes the infimum of the initial capitals that allow an investor to super-replicate the contingent claim by carefully choosing an investment strategy obeying a gamma constraint. This infimum is shown to be the unique viscosity solution of a nonstandard partial differential equation. Due to the lower gamma bound, the “intuitive” partial differential equation is not parabolic and the actual equation satisfied by the infimum is the parabolic majorant of this equation. The derivation of the viscosity property is based on new results on the small time behavior of double stochastic integrals.

Résumé

La stratégie de couverture classique d'une option européenne, dictée par le modèle de Black et Scholes, peut conduire à des rebalancements rapides du portefeuille répliquant. Afin d'éviter de telles situations indésirables, nous introduisons des contraintes spécifiques sur le portefeuille, appelées
contraintes gamma
. Il n'est alors pas possible en général de répliquer parfaitement l'option européene. Par conséquent, la surréplication est alors une alternative fréquemment utilisée. Dans ce papier, on caractérise l'infimum des capitaux initiaux qui permet à un investiseur de surrépliquer l'actif contingent en choisissant soigneusement une stratégie de portefeuile satisfaisant à une contrainte gamma. Nous montrons que cet infimum est l'unique solution de viscosité d'une équation aux dérivées partielles non standard. A cause de la borne inférieure sur la contrainte gamma, l'équation aux dérivées partielles « intuitive » n'est pas parabolique, et l'équation effectivemet satisfaite par l'infimum est le mojorant parabolique de l'équation « intuitive ». L'obtention de la propriété de viscosité s'appuie sur des résultats nouveaux portant sur des intégrales stochastiques doubles.
Semilinear equations with exponential nonlinearity and measure data
Authors: Ponce Augusto C. , Bartolucci Daniele , Leoni Fabiana , Orsina Luigi 
Published: April 2005

We study the existence and non-existence of solutions of the problem

\tag{0.1}
\begin{cases} −\mathrm{\Delta }u + \mathrm{e}^{u}−1 = \mu & \mathrm{in}\:\Omega , \\ u = 0 & \mathrm{on}\:\partial \Omega ,
\end{cases}

where

Ω

is a bounded domain in

\mathbb{R}^{N}

,

N⩾3

, and

μ

is a Radon measure. We prove that if

\mu ⩽4\pi \mathcal{H}^{N−2}

, then (0.1) has a unique solution. We also show that the constant

4π

in this condition cannot be improved.

Résumé
Nous étudions l'existence et la non existence des solutions de l'équation

\tag{0.2}
\begin{cases} −\mathrm{\Delta }u + \mathrm{e}^{u}−1 = \mu & \mathrm{dans}\:\Omega , \\ u = 0 & \mathrm{sur}\:\partial \Omega ,
\end{cases}

où

Ω

est un domaine borné dans

\mathbb{R}^{N}

,

N⩾3

, et

μ

est une mesure de Radon. Nous démontrons que si

μ

vérifie

\mu ⩽4\pi \mathcal{H}^{N−2}

, alors le problème (0.2) admet une unique solution. Nous montrons que la constante

4π

dans cette condition ne peut pas être améliorée.
Heart failure programmes in countries with a primary care‐based health care system. Are additional trials necessary? Design of the DEAL‐HF study
Authors: de la Porte Pieta W.F. Bruggink‐André , Lok Dirk J.A. , van Wijngaarden Jan , Cornel Jan H. , Pruijsers‐Lamers Dian , van Veldhuisen Dirk J. , Hoes Arno W. 
Published: April 2005

AbstractBackgroundSeveral randomised studies of heart failure (HF) management programmes in the United States, Australia and Europe have shown a considerable reduction in hospitalisation rates for HF. In this article, a comprehensive review of these studies will be provided and their applicability to countries, with a primary care‐based healthcare system, will be discussed. In addition, the design of the Deventer‐Alkmaar HF Project (DEAL‐HF), a randomised study of the effect of a nurse and physician‐directed intervention over 1 year in The Netherlands, will also be presented.AimTo discuss the applicability of the results of available studies on heart failure management programmes to countries with well‐structured primary care facilities and to determine whether additional trials should be conducted in these countries.MethodsWe performed a literature search in PubMed. In a review of the available studies, essential methodological aspects, in particular, the population involved, the sample size, follow‐up period, setting, type of intervention, and the outcome parameters, are discussed critically. Also, the applicability of these studies to countries with a primary care‐based healthcare system and easy access to medical care is evaluated.ConclusionApplicability of the results of the available studies on the efficacy of heart failure management programmes to countries with a primary care‐based health care system is doubtful. An efficacy trial in a country with a well‐established primary care‐based healthcare system, such as The Netherlands, is due to report soon (DEAL‐HF).
Anti‐inflammatory effects of continuous passive motion on meniscal fibrocartilage
Authors: Ferretti Mario , Srinivasan Abiraman , Deschner James , Gassner Robert , Baliko Frank , Piesco Nicholas , Salter Robert , Agarwal Sudha 
Published: April 2005

AbstractMotion‐based therapies have been applied to promote healing of arthritic joints. The goal of the current study was to determine the early molecular events that are responsible for the beneficial actions of motion‐based therapies on meniscal fibrocartilage. Rabbit knees with Antigen‐Induced‐Arthritis (AIA) were exposed to continuous passive motion (CPM) for 24 or 48 h and compared to immobilized knees. The menisci were harvested and glycosaminoglycans (GAG), interleukin‐1β (IL‐1β), matrix metalloproteinase‐1 (MMP‐1), cyclooxygenase‐2 (COX‐2), and interleukin‐10 (IL‐10) were determined by histochemical analysis.Within 24 h, immobilized knees exhibited marked GAG degradation. The expression of proinflammatory mediators MMP‐1, COX‐2, and IL‐1β was notably increased within 24 h and continued to increase during the next 24 h in immobilized knees. Knees subjected to CPM revealed a rapid and sustained decrease in GAG degradation and the expression of all proinflammatory mediators during the entire period of CPM treatment. More importantly, CPM induced synthesis of the anti‐inflammatory cytokine IL‐10. The results demonstrate that mechanical signals generated by CPM exert potent anti‐inflammatory signals on meniscal fibrochondrocytes. Furthermore, these studies explain the molecular basis of the beneficial effects of CPM observed on articular cartilage and suggest that CPM suppresses the inflammatory process of arthritis more efficiently than immobilization. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Initial Test of a Bayesian Approach to Solar Flare Prediction
Authors: Wheatland Michael S. 
Published: April 2005

AbstractA test of a new Bayesian approach to solar flare prediction is presented. The approach uses the past history of flaring together with phenomenological rules of flare statistics to make a prediction for the probability of occurrence of a large flare within an interval of time, or to refine an initial prediction (which may incorporate other information). The test of the method is based on data from the Geostationary Observational Environmental Satellites, and involves whole-Sun prediction of soft X-ray flares for 1976–2003. The results show that the method somewhat over-predicts the probability of all events above a moderate size, but performs well in predicting large events.
Neutrinos from Relativistic Outflows of Fast Spinning Magnetars
Authors: Luo Qinghuan 
Published: April 2005

AbstractPulsars may be born with a short rotation period of milliseconds with the magnetic field amplified through dynamo processes up to ∼1015–1016 G. Such millisecond magnetars spin down rapidly, emitting bursts of high-energy neutrinos and gamma rays. Specifically, acceleration of ions in both the polar gap (as in a normal pulsar) and the relativistic magnetar wind is considered. In both cases ions can be accelerated to ultra-high energies and these energetic ions can lead to production of high-energy neutrinos and gamma rays through interaction with thermal radiation from the hot neutron star or the heated inner boundary region of the stellar envelope as the result of the deposition of energy by the magnetar wind. The detectability of the neutrino flux by a kilometre-scale neutrino detector such as the planned IceCube neutrino observatory is discussed.
A Fuzzy Logic Based Algorithm for Finding Astronomical Objects in Wide-Angle Frames
Authors: Shamir Lior , Nemiroff Robert J. 
Published: April 2005

AbstractAccurate automatic identification of astronomical objects in an imperfect world of non-linear wide-angle optics, imperfect optics, inaccurately pointed telescopes, and defect-ridden cameras is not always a trivial first step. In the past few years, this problem has been exacerbated by the rise of digital imaging, providing vast digital streams of astronomical images and data. In the modern age of increasing bandwidth, human identifications are many times impracticably slow. In order to perform an automatic computer-based analysis of astronomical frames, a quick and accurate identification of astronomical objects is required. Such identification must follow a rigorous transformation from topocentric celestial coordinates into image coordinates on a CCD frame. This paper presents a fuzzy logic based algorithm that estimates needed coordinate transformations in a practical setting. Using a training set of reference stars, the algorithm statically builds a fuzzy logic model. At runtime, the algorithm uses this model to associate stellar objects visible in the frames to known cataloged objects, and generates files that contain photometry information of objects visible in the frame. Use of this algorithm facilitates real-time monitoring of stars and bright transients, allowing identifications and alerts to be issued more reliably. The algorithm is being implemented by the Night Sky Live all-sky monitoring global network and has shown itself significantly more reliable than the previously used non-fuzzy logic algorithm.