bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional cortical changes of the sensorimotor network are associated with clinical recovery in multiple sclerosis
Authors: Mezzapesa Domenico M. , Rocca Maria A. , Rodegher Mariaemma , Comi Giancarlo , Filippi Massimo 
Published: May 2007

AbstractObjective:To assess the early cortical changes following an acute motor relapse secondary to a pseudotumoral lesion in MS patients, the longitudinal cortical functional correlates of clinical recovery, and the evolution over time of cortical reorganization.Methods:FMRI during the performance of a simple motor task were obtained from 12 MS patients (after a clinical attack involving the motor system secondary to a pseudotumoral lesion) and 15 matched controls. In six patients and five controls, a longitudinal fMRI study was also performed.Results:In patients, at baseline, the primary sensorimotor cortex (SMC) of the ipsilateral (contralesional) hemisphere was significantly more active during task performance with the impaired than the unimpaired hand. During task performance with the unimpaired hand, the ipsilateral cerebellum and several motor areas in the contralateral hemisphere were significantly more active. Pseudotumoral lesion volume was correlated with activation of the primary SMC bilaterally (r = −0.86 and −0.85) and the nine‐hole peg test score with activation of the primary SMC of the affected hemisphere (r = 0.88). A recovery of function of the primary SMC of the affected hemisphere was found in the four patients with clinical improvement. In the two patients without clinical recovery, there was a persistent recruitment of the primary SMC of the unaffected hemisphere.Conclusions:Pseudotumoral MS lesions affecting the motor system can determine short‐term cortical changes characterized by the recruitment of pathways in the unaffected hemisphere. The regain of function of motor areas of the affected hemisphere seems to be a critical factor for a favorable recovery. Hum Brain Mapp 2008. © 2007 Wiley‐Liss, Inc.
OFT, VBP: QED?
Authors: Claxton Karl 
Published: May 2007

AbstractThe report by the Office of Fair Trading (OFT) on the UK pharmaceutical price regulation scheme (PPRS) recommends the reform of the current scheme, which is a combination of profit and price controls, to one where price is based on the health benefits offered by a pharmaceutical. On closer examination some of the more commonly expressed concerns about these proposals do not seem to be well founded.In principle, the OFT's recommendations may contribute to allocative and dynamic efficiency in the NHS. However, there are some dangers and the details of how it will be implemented are crucial. For example, value‐based pricing with an inappropriate threshold for cost‐effectiveness, or an inappropriate pricing structure, could lead to technologies being adopted at prices where their benefits, in terms of health outcome, do not offset the health displaced elsewhere in the NHS, a situation in which the NHS is damaged rather than improved by innovation. A failure to account for uncertainty and the value of evidence in negotiating prices and coverage could also undermine the evidence base for future NHS practice. Whatever view is taken, the OFT report will inevitably shape the scope of future policy debates about value, guidance, price and innovation. Copyright © 2007 John Wiley & Sons, Ltd.
Composite suspended sediment particles in river systems: their incidence, dynamics and physical characteristics
Authors: Woodward J. C. , Walling D. E. 
Published: May 2007

AbstractMost of the existing data on the effective particle size characteristics of fluvial suspended sediment derive from instantaneous sampling methods that may not be representative of the overall suspended sediment loads. This presents difficulties when there is a need to incorporate effective particle size data into numerical models of floodplain sedimentation and sediment‐associated contaminant transfer. We have used a field‐based water elutriation apparatus (WEA) to assemble a large (36 flood) database on the time‐integrated nature of the effective and absolute particle size characteristics of suspended sediment in four subcatchments of the River Exe basin of southwest England. These catchments encompass a wide range of terrains and fluvial environments that are broadly representative of much of the UK and temperate, low relief northwest Europe. The WEA provides important data on the physical characteristics of composite particles that are not attainable using other methods. This dataset has allowed, for the first time, detailed interbasin comparisons of the time‐integrated particle size characteristics of suspended sediment and reliable estimates of the contribution of five effective size classes to the mean annual suspended sediment load of the study catchments. The suspended sediment load of each river is dominated by composite rather than primary particles, with, for example, almost 60% (by mass) of the sediment load of the River Exe at Thorverton transported as composite particles > 16 µm in size. All the effective size classes contain significant clay components. A key outcome of this study is the recognition that each catchment has a distinctive time‐integrated effective particle size signature. In addition, the time‐integrated effective particle size characteristics of the suspended loads in each of the catchments display much greater spatial variability than the equivalent absolute particle size distributions. This indicates that the processes producing composite particles vary significantly between these catchments, and this has important implications for our understanding of the dynamics of suspended sediment properties. Copyright © 2007 John Wiley & Sons, Ltd.
On a Question of Phillips
Authors: Gencer Çiǧdem , Terziler Mehmet 
Published: May 2007

AbstractIn [5] Phillips proved that one can obtain the additive group of any nonstandard model *ℤ of the ring ℤ of integers by using a linear mod 1 function h : F ℚ, where F is the α‐dimensional vector space over ℚ when α is the cardinality of *ℤ. In this connection it arises the question whether there are linear mod 1 functions which are neither addition nor quasi‐linear. We prove that this is the case.
Order‐free Recursion on the Real Numbers
Authors: Brattka Vasco 
Published: May 2007

AbstractWe investigate operations, computable in the sense of Recursive Analysis, which can be generated recursively from the arithmetic operations and the limit operation without using any tests on the real numbers. These functions, called order‐free recursive, can be shown to include a large class of computable functions. As main tools we provide an effective version of the Stone‐Weierstraß Approximation Theorem, as well as recursive partitions of unity.
On Nondeterminism, Enumeration Reducibility and Polynomial Bounds
Authors: Copestake Kate 
Published: May 2007

AbstractEnumeration reducibility is a notion of relative computability between sets of natural numbers where only positive information about the sets is used or produced. Extending e‐reducibility to partial functions characterises relative computability between partial functions. We define a polynomial time enumeration reducibility that retains the character of enumeration reducibility and show that it is equivalent to conjunctive non‐deterministic polynomial time reducibility. We define the polynomial time e‐degrees as the equivalence classes under this reducibility and investigate their structure on the recursive sets, showing in particular that the pe‐degrees of the computable sets are dense and do not form a lattice, but that minimal pairs exist. We define a jump operator and use it to produce a characterisation of the polynomial hierarchy.
On Interstices of Countable Arithmetically Saturated Models of Peano Arithmetic
Authors: Bamber Nicholas , Kotlarski Henryk 
Published: May 2007

AbstractWe give some information about the action of Aut(M) on M(0), where M is a countable arithmetically saturated model of Peano Arithmetic. We concentrate on analogues of moving gaps and covering gaps inside M(0).
Arithmetical Measure
Authors: Terwijn Sebastiaan A. , Torenvliet Leen 
Published: May 2007

AbstractWe develop arithmetical measure theory along the lines of Lutz [10]. This yields the same notion of measure 0 set as considered before by Martin‐Löf, Schnorr, and others. We prove that the class of sets constructible by r.e.‐constructors, a direct analogue of the classes Lutz devised his resource bounded measures for in [10], is not equal to RE, the class of r.e. sets, and we locate this class exactly in terms of the common recursion‐theoretic reducibilities below K. We note that the class of sets that bounded truth‐table reduce to K has r.e.‐measure 0, and show that this cannot be improved to truth‐table. For Δ2‐measure the borderline between measure zero and measure nonzero lies between weak truth‐table reducibility and Turing reducibility to K. It follows that there exists a Martin‐Löf random set that is tt‐reducible to K, and that no such set is btt‐reducible to K. In fact, by a result of Kautz, a much more general result holds.
Elementary Properties of the Finite Ranks
Authors: Dawar Anuj , Doets Kees , Lindell Steven , Weinstein Scott 
Published: May 2007

AbstractThis note investigates the class of finite initial segments of the cumulative hierarchy of pure sets. We show that this class is first‐order definable over the class of finite directed graphs and that this class admits a first‐order definable global linear order. We apply this last result to show that FO(<, BIT) = FO(BIT).
Microwave‐Assisted Synthesis of Associative Hydrogels
Authors: Kretschmann Oliver , Schmitz Sarah , Ritter Helmut 
Published: May 2007

AbstractIn the present paper, the microwave (MW)‐assisted synthesis of hydrogel forming polymers based on poly(acrylic acid) (1) is described. The polymer analogous condensation reaction between adamantyl moieties bearing free amino groups and poly(acrylic acid) (1) was carried out simply by mixing both components and subsequent use of MW protocol. The mixture was irradiated for 20 min without the addition of solvents or coupling agents. Aqueous solutions of the sodium salts of the obtained hydrophobically modified poly(acrylic acid)s showed a very high viscosity due to the intermolecular association of the hydrophobic side chains and the resulting formation of physical networks. By the addition of randomly methylated β‐cyclodextrin (RAMEB), the rheology of these systems could be influenced significantly.magnified image
Mechanism of the formation of singularities for quasilinear hyperbolic systems with linearly degenerate characteristic fields
Authors: Li Ta‐Tsien , Peng Yue‐Jun , Yang Yong‐Fu , Zhou Yi 
Published: May 2007

AbstractOne often believes that there is no shock formation for the Cauchy problem of quasilinear hyperbolic systems (of conservation laws) with linearly degenerate characteristic fields. It has been a conjecture for a long time (see Arch. Rational Mech. Anal. 2004; 172:65–91; Compressible Fluid Flow and Systems of Conservation Laws in Several Space Variables. Springer: New York, 1984) and it is still an open problem in the general situation up to now. In this paper, a framework to justify this conjecture is proposed, and, by means of the concept such as the
strict block hyperbolicity, the part richness and the successively block‐closed system, some general kinds of quasilinear hyperbolic systems, which verify the conjecture, are given. Copyright © 2007 John Wiley & Sons, Ltd.
Defect investigation of stacked self‐assembled InAs/GaAs quantum dot lasers
Authors: Ng J. , Bangert U. , Missous M. 
Published: May 2007

AbstractTwo classes of stacked structures with (i) varying InAs nominal thickness θ but fixed GaAs “spacer” layer (d = 25 nm), and ii) a varying d but fixed InAs nominal thickness (θ = 2.73 monolayers (ML)) were grown by solid‐source molecular beam epitaxy (MBE). The formation of large ‘volcano‐like' defects with stacking faults and dislocations, penetrating several layers into the stack, was observed for a nominal InAs deposition of 2.73 ML and 3.62 ML in case (i). In case (ii), with, d = 50 nm, a dramatic improvement in structural integrity was observed with the absence of the ‘volcano‐like’ defect. The Photoluminescence (PL) intensity where, d = 50 nm, was almost 132 times stronger for, θ = 3.64 ML, indicating that the improvement in crystal structure resulted in better PL efficiencies. Remarkably, significant improvements in PL intensity were observed when the material was etched to selectively remove the topmost stacks thus demonstrating that the ‘volcano‐like’ defects were responsible for the severely suppressed PL efficiencies. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum confinement effect in nanohills formed on a surface of Ge by laser radiation
Authors: Medvid Artur , Dmytruk Igor , Onufrijevs Pavels , Pundyk Iryna 
Published: May 2007

AbstractPhotoluminescence in visible range of spectra from nanohills formed on a surface of Ge single crystal by JAG:Nd laser radiation was found. This photoluminescence is explained by quantum confinement effect in quantum dots on a top of nanohills. Red shift of 300 cm–1 line micro‐Raman back scattering spectrum is an evidence of this suggestion. The calculation of QDs diameter using band gap shift photoluminescence spectra and peak frequency in micro‐Raman spectra as a function of diameter for spherical Ge particles gives diameters of nano‐balls on the top of nanohills is 4 nm and 6 nm. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sources of misfit dislocations in ZnSe/GaAs (001) heterostructures
Authors: Lavagne S. , Levade C. , Vanderschaeve G. 
Published: May 2007

AbstractStrain relaxation in low‐mismatch ZnSe/GaAs heterostructures is studied by transmission electron microscopy. The early stages of plastic relaxation proceeds by activation of secondary 1/2〈011〉{133}slip systems, leaving an array of misfit dislocations aligned along 〈310〉 directions in the interface. Threading dislocations originate from randomly distributed, highly strained single‐or multi‐twinned regions in the ZnSe layer, that are probably due to growth accidents. The influence of cross slip on the propagation of threading dislocations is discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Global benefit–risk assessment in designing clinical trials and some statistical considerations of the method
Authors: Pritchett Yili Lu , Tamura Roy 
Published: May 2007

AbstractWhen characterizing a therapy, the efficacy and the safety are two major aspects under consideration. In prescribing a therapy to a patient, a clinician puts the two aspects together and makes a decision based on a consolidated thought process. The global benefit–risk (GBR) measures proposed by Chuang‐Stein et al. (Stat. Med. 1991; 10:1349–1359) are useful in facilitating the thinking, and creating the framework for making statistical comparisons based on benefit–risk point of view. This article describes how a GBR linear score was defined and used as the primary outcome measure in a clinical trial design. The robustness of the definitions of ‘benefit’ and ‘risk’ are evaluated using different criteria. The sensitivity of the pre‐specified weights is also analyzed using alternative weights; one of those was determined by the relative to an identified distribution integral transformation approach (Biometrics 1958; 14:18–38). Statistical considerations are illustrated using pooled data from clinical trials studying antidepressant. The pros and cons for using GBR assessments in the setting of clinical trials are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Density functional study of protonation of deoxynucleosides: Electrophilic active sites and proton affinities
Authors: Xia Fei , Xie Hujun , Cao Zexing 
Published: May 2007

AbstractPossible low‐energy tautomers and their interconversions, electrophilic active sites, and proton affinities of deoxyribonucleosides have been studied by the density functional theory. The calculated results indicate that the protonation features of deoxyribonucleosides are less changed as compared with their corresponding bases. Proton affinities of 2′‐deoxyriboguanosine (dG), 2′‐deoxyribocytidine (dC), 2′‐deoxyriboadenosine (dA), and 2′‐deoxyribothymidine (dT) at the most favored sites are 240.6 kcal mol−1 (N7), 238.5 kcal mol−1 (N3), 233.4 kcal mol−1 (N1), and 217.9 kcal mol−1 (O4), respectively. Predicted tautomerization barriers are substantially high and exclude the coexistence possibility of their low‐energy tautomers at room temperatures. Calculations show good agreement with experiments and provide a basis for description of structures and energetics of neutral and protonated deoxyribonucleosides. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Polymer Grafting from CdS Quantum Dots via AGET ATRP in Miniemulsion
Authors: Esteves Ana C. C. , Bombalski Lindsay , Trindade Tito , Matyjaszewski Krzysztof , Barros‐Timmons Ana 
Published: May 2007

AbstractWe report the synthesis of CdS quantum dot (QD)–poly(acrylate) nanocomposites using a recently developed catalytic system where activators are generated by electron transfer for atom‐transfer radical polymerization (ATRP) in a miniemulsion. The QD surface was functionalized with a tris(alkyl)phosphine, previously modified with an ATRP chlorine initiator, and subsequent controlled polymerization was carried out from the functionalized surface of nanoparticles. The final material showed a high homogeneity and the QDs were evenly dispersed. The optical‐absorption edge in the visible spectra of the nanocomposites attests the presence of the CdS QDs. Quantum confinement effects were assigned, though a blue shift in relation to the optical spectrum of the initial QDs has been observed.
Zur Stabilität der elastischen Schalen I
Authors: Deuker Ernst‐August 
Published: May 2007

AbstractIn der vorliegenden Arbeit werden die untersuchungen über endliche Verformungen eines Kontinuums und die aus ihnen abzuleitenden Stabilitätskriterien des elastischen Gleichgewichts,wie ich sie an anderer Stelle[3] für den allgemeinen Dreidimensionalen Körper Angestellt habe, auf dünne elastische Schalen übertragen. Es werden deshalb Zunächst die Grundgleichungen der Schalentheorie fü endliche Verformungen entwickelt, als notwendige Grundlage für Stabilitätsuntersuchungen. Die Heranziehung der Methoden und Ergebnisse der Differentialgeometrie, insbesondere die konsequente Anwendung der Tensorrechnung, ermöglicht nicht nur, allgemeine Formeln von großer Durchsichtigkeit zu entwickeln, sondern erleichtert auch die Behandlung spezieller Probleme. In dieser Arbeit wird das an dem Beispiel der Kreiszylinderschale, in einer weiteren an dem der Kugelschale gezeigt werden.
Wärmeausgleichsvorgänge in bestrahlten Platten
Authors: Ludwig Konrad 
Published: May 2007

AbstractDie Wärmeausgleichsvorgänge in einer einseitig bestrahlten Platte, deren konstante Anfangstemperatur die der Umgebung ist, werden untersucht. Dabei wird außer der eingestrahlten auch die durch diese Begrenzungsebene ausgestrahlte Wärme berücksichtigt. Die Lösung wird sowohl durch Produktansatz, wie nach der Operatorenmethode gewonnen. Als Beispiel berechnet Verfasser zahlenmäßig für ein Silber‐ und für ein Wismutplättchen mit und ohne Wärmeabgabe der nicht bestrahlten Begrenzungsebene die Temperatur der bestrahlten Begrenzungsebene und die Differenz der Temperaturen der beiden Begrenzungsebenen als Funktionen der Zeit.
Über die Teststärke des Fisherschen Testes
Authors: Richter Hans 
Published: May 2007

AbstractBei festen Marginalien einer 2×2‐Tafel, die das Ergebnis der Anwendung zweier Bearbeitungsverfahren widerspiegelt, und bei Vorgabe einer Signifikanzschranke α für die Anwendung des Fisherschen Testes ist die Teststärke P« allein abhängig von einem Parameter ξ, der die Überlegenheit des neuen Bearbeitungsverfahrens über das alte charakterisiert. Der Test besitzt einen zu α gehörigen Unempfindlichkeits‐ξ‐Bereich 0 ≤ ξ ≤ ξ0 Für Pξ und ξ0 werden Formeln abgeleitet, die für große Werte der Marginalien einfache Approximationen gestatten. Jedoch ist auch für kleine Werte der Marginalien die Approximation für ξ0 noch ausreichend.
Physical and chemical characteristics of butterfat fractions obtained by crystallization from molten fat
Authors: Amer M. A. , Kupranycz D. B. , Baker B. E. 
Published: May 2007

AbstractBoth summer and winter butterfats were fractionated using a laboratory procedure which was designed to simulate a commercial fractionation process. The process is based on a slow, controlled cooling of the melted fat, a short stabilization time at the fractionation temperature, and separation of the crystals from the liquid oil by vacuum filtration using a stainless steel perforated disc. Fractionation temperatures of 29, 26, 23 and 19 C for winter butterfat and 29 and 19 C for summer butterfat were used to obtain solid and liquid fractions at each temperature. Three replications at each temperature showed good reproducibility of results. The fractions were characterized by their fatty acid and triglyceride compositions, melting and crystallization behavior, iodine value, peroxide value and melting point.
Sunflower oil diesel fuel: Engine wear implications
Authors: Rewolinski C. , Shaffer D. L. 
Published: May 2007

AbstractDiesel lubricating oil contaminated with sunflower oil fuel was degraded under conditions simulating an engine crankcase environment for metal wear testing. Wear analyses were performed using a fourball apparatus according to ASTM D 4172. Lubricity of oils was characterized by ball scar dimensions. Contaminated lubricating oils exhibited lower metal wear indexes than pure lube oil control samples, even when the former were severely degraded as measured by thickening and loss of alkaline reserve.
2‐trans,4‐cis,7‐cis‐Decatrienal, the fishy off‐flavor occurring in strongly autoxidized oils containing linolenic acid or ω 3,6,9, etc., fatty acids
Authors: Meijboom P. W. , Stroink J. B. A. 
Published: May 2007

AbstractA possible decomposition product of oils containing unsaturated fatty acids with the double bond pattern ω3,6,9 or ω3,6,9, etc., is 2‐trans,4‐cis,7‐cis‐decatrienal. It has therefore been investigated whether this trienal is present in strongly autoxidized linolenic acid, soybean, linseed and fish oils. Via a degassing technique the carbonyls from the samples of oils heated in a closed system under nitrogen were collected and separated as their 2,4‐dinitrophenylhydrazones (DNPHs) by thin layer chromatography (TLC). The presence of 2‐trans,4‐cis,7‐cis‐decatrienal in the samples was positively established by TLC, UV absorption and mass spectroscopy of its DNPH. All analytical data established the complete identity of the isolated DNPH with a synthesized 2,4,7‐decatrienal‐DNPH. The free aldehyde obtained on hydrolysis of the alkatrienal‐DNPH in question had the same flavor as authentic 2‐trans,4‐cis,7‐cis‐decatrienal, having a fish or rather a whale oil flavor.
Direct esterification of sodiumcis‐9,10‐epiminooctadecanoate
Authors: Bilyk A. , Eisner A. , Maerker G. 
Published: May 2007

AbstractCompounds containing the aziridine ring are known to have a tendency toward polymerization in the presence of mineral acids. Moreover, with aziridine derivatives of fatty acids, ring opening reactions are possible as a result of nucleophilic attack by generated carboxylic acids groups. It was found that high yields (86–89%) of methylcis‐9,10‐epiminooctadecanoate, with a minimum of attendant byproducts could be obtained by heating the corresponding sodium soap with methanol in the presence of certain acid catalysts under carefully controlled conditions. Temperature, duration of the heating period, and catalyst concentration were the variables studied for each catalyst. The catalysts evaluated were: boron trifluoride etherate, methanesulfonic acid, sulfuric acid, fluoboric acid andp‐toluenesulfonic acid. Of these, for most laboratory preparations,p‐toluenesulfonic acid is the catalyst of choice.