bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrashort TE imaging with off‐resonance saturation contrast (UTE‐OSC)
Authors: Du Jiang , Takahashi Atsushi M. , Bydder Mark , Chung Christine B. , Bydder Graeme M. 
Published: May 2009

AbstractShort T2 species such as the Achilles tendon and cortical bone cannot be imaged with conventional MR sequences. They have a much broader absorption lineshape than long T2 species, therefore they are more sensitive to an appropriately placed off‐resonance irradiation. In this work, a technique termed ultrashort TE (UTE) with off‐resonance saturation contrast (UTE‐OSC) is proposed to image short T2 species. A high power saturation pulse was placed +1 to +2 kHz off the water peak to preferentially saturate signals from short T2 species, leaving long T2 water and fat signals largely unaffected. The subtraction of UTE images with and without an off‐resonance saturation pulse effectively suppresses long T2 water and fat signals, creating high contrast for short T2 species. The UTE‐OSC technique was validated on a phantom, and applied to bone samples and healthy volunteers on a clinical 3T scanner. High‐contrast images of the Achilles tendon and cortical bone were generated with a high contrast‐to‐noise ratio (CNR) of the order of 12 to 20 between short T2 and long T2 species within a total scan time of 4 to 10 min. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
High resolution diffusion‐weighted imaging using readout‐segmented echo‐planar imaging, parallel imaging and a two‐dimensional navigator‐based reacquisition
Authors: Porter David A. , Heidemann Robin M. 
Published: May 2009

AbstractSingle‐shot echo‐planar imaging (EPI) is well established as the method of choice for clinical, diffusion‐weighted imaging with MRI because of its low sensitivity to the motion‐induced phase errors that occur during diffusion sensitization of the MR signal. However, the method is prone to artifacts due to susceptibility changes at tissue interfaces and has a limited spatial resolution. The introduction of parallel imaging techniques, such as GRAPPA (GeneRalized Autocalibrating Partially Parallel Acquisitions), has reduced these problems, but there are still significant limitations, particularly at higher field strengths, such as 3 Tesla (T), which are increasingly being used for routine clinical imaging. This study describes how the combination of readout‐segmented EPI and parallel imaging can be used to address these issues by generating high‐resolution, diffusion‐weighted images at 1.5T and 3T with a significant reduction in susceptibility artifact compared with the single‐shot case. The technique uses data from a 2D navigator acquisition to perform a nonlinear phase correction and to control the real‐time reacquisition of unusable data that cannot be corrected. Measurements on healthy volunteers demonstrate that this approach provides a robust correction for motion‐induced phase artifact and allows scan times that are suitable for routine clinical application. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
In vivo differentiation of two vessel wall layers in lower extremity peripheral vein bypass grafts: Application of high‐resolution inner‐volume black blood 3D FSE
Authors: Mitsouras Dimitris , Owens Christopher D. , Conte Michael S. , Ersoy Hale , Creager Mark A. , Rybicki Frank J. , Mulkern Robert V. 
Published: May 2009

AbstractLower extremity peripheral vein bypass grafts (LE‐PVBG) imaged with high‐resolution black blood three‐dimensional (3D) inner‐volume (IV) fast spin echo (FSE) MRI at 1.5 Tesla possess a two‐layer appearance in T1W images while only the inner layer appears visible in the corresponding T2W images. This study quantifies this difference in six patients imaged 6 months after implantation, and attributes the difference to the T2 relaxation rates of vessel wall tissues measured ex vivo in two specimens with histologic correlation. The visual observation of two LE‐PVBG vessel wall components imaged in vivo is confirmed to be significant (P < 0.0001), with a mean vessel wall area difference of 6.8 ± 2.7 mm2 between contrasts, and a ratio of T1W to T2W vessel wall area of 1.67 ± 0.28. The difference is attributed to a significantly (P < 0.0001) shorter T2 relaxation in the adventitia (T2 = 52.6 ± 3.5 ms) compared with the neointima/media (T2 = 174.7 ± 12.1 ms). Notably, adventitial tissue exhibits biexponential T2 signal decay (P < 0.0001 vs monoexponential). Our results suggest that high‐resolution black blood 3D IV‐FSE can be useful for studying the biology of bypass graft wall maturation and pathophysiology in vivo, by enabling independent visualization of the relative remodeling of the neointima/media and adventitia. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Interleaved spiral‐in/out with application to functional MRI (fMRI)
Authors: Law Christine S. , Glover Gary H. 
Published: May 2009

AbstractThe conventional spiral‐in/out trajectory samples k‐space sufficiently in the spiral‐in path and sufficiently in the spiral‐out path to enable creation of separate images. We propose an “interleaved spiral‐in/out” trajectory comprising a spiral‐in path that gathers one half of the k‐space data, and a complimentary spiral‐out path that gathers the other half. The readout duration is thereby reduced by approximately half, offering two distinct advantages: reduction of signal dropout due to susceptibility‐induced field gradients (at the expense of signal‐to‐noise ratio [SNR]), and the ability to achieve higher spatial resolution when the readout duration is identical to the conventional method. Two reconstruction methods are described; both involve temporal filtering to remove aliasing artifacts. Empirically, interleaved spiral‐in/out images are free from false activation resulting from signal pileup around the air/tissue interface, which is common in the conventional spiral‐out method. Comparisons with conventional methods using a hyperoxia stimulus reveal greater frontal‐orbital activation volumes but a slight reduction of overall activation in other brain regions. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Contamination of single‐voxel multiple quantum filters by external water signals arising from intermolecular multiple quantum coherences
Authors: Thompson Richard B. , Allen Peter S. 
Published: May 2009

AbstractMultiple‐quantum filtered pulse sequences simplify overlapping metabolite spectra by the elimination of peaks from uncoupled spin species, most notably from methyl groups and water, and the minimization of unwanted coupled‐spin peaks. However, it is shown in this study that a significant contaminant water signal can pass through this family of filters in the form of intermolecular multiple‐quantum coherences. An imaging evaluation of a single‐voxel multiple quantum filter experiment confirms that the water contamination is excited from outside of the voxel of interest, thus having an increased potential for broad spectral contamination. Phantom and in vivo experiments at 3.0 T are used to illustrate, first, significant water contamination of a single‐voxel double quantum filter experiment optimized for the observation of glutamate, and second, the elimination of the unwanted water signal with conventional phase cycling and optimized filter gradient orientations. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Public participation and the concept of space in environmental governance: An application of PPGIS
Authors: Sun Milan Tung‐Wen , Tsai Yun‐Tung , Shih Mei‐Chiang , Lin Jessica Yu‐Wen 
Published: May 2009

AbstractCitizen participation ought to be important in environmental governance. However, environmental issues are usually defined as science‐related ones, wherein expert knowledge is more important than the opinions, demands or needs of citizens. On the other hand, environmental issues involve spatial dimensions, the geographic characteristics of which require specific techniques to analyse. PPGIS is applied to study An‐Shun, the site of a well‐known pollution case in Taiwan, to reveal, through a participatory process, the perception of space of citizens of a nearby community. The results of this study suggest that the government needs to ensure more citizen participation in its future plans for the decontamination and renovation of the An‐Shun site. Lay knowledge or citizen perceptions of space should not replace scientific knowledge, but can supplement it. They are additional views that ought to be considered by government agencies in dealing with environmental issues. Copyright © 2009 John Wiley & Sons, Ltd.
Assessment of Armenian local government corruption potential
Authors: Coxson Samuel Louis 
Published: May 2009

AbstractLocal government in many developing countries is prone to institutional and individual corruption. Using a set of questions developed for a Baseline Review of the status of procedures and practices of Armenian local governments, a general matrix was developed that may be applied to any local government in any country. The matrix looks at three broad areas where the potential for corruption has historically been high: awareness and reporting suspected corruption, procurement practices, and internal control practices and procedures. This article presents a methodology (the matrix questions) that will enable the development practitioner to rapidly assess the corruption potential and develop training or technical assistance to reduce the corruption potential. Copyright © 2009 John Wiley & Sons, Ltd.
Different problems associated with the stress trajectories element method (Poster Presentation)
Authors: Galybin A. N. 
Published: May 2009

AbstractThis study deals with the determination of stresses in statically determined solids of arbitrary rheology. The stress trajectory concept is used as the basic element in numerical formulations. Different types of data can be employed, which necessitates consideration of different mathematical problems associated with the stress identification. Three classes of data are discussed and an example from geodynamic is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Acoustic scattering by a thin cylindrical screen with Dirichlet and impedance boundary conditions on opposite sides of the screen
Authors: Krutitskii Pavel , Kolybasova Valentina 
Published: May 2009

AbstractA problem on scattering acoustic waves by a thin cylindrical screen is studied. In doing so, the Dirichlet condition is specified on one side of the screen, while the impedance boundary condition is specified on the other side of the screen. The solution of the problem is subject to the radiating condition at infinity and to the propagative Helmholtz equation. By using the potential theory the scattering problem is reduced to a system of singular integral equations with additional conditions. By regularization and subsequent transformations, this system is reduced to a vector Fredholm equation of the second kind and index zero. It is proved that the obtained vector Fredholm equation is uniquely solvable. Therefore the integral representation for a solution of the original scattering problem is obtained. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient calibration for problems in option pricing
Authors: Giese A. M. , Kaebe C. , Maruhn J. H. , Sachs E. W. 
Published: May 2009

AbstractThe pricing of derivatives has gained considerable importance in the finance industry and leads to challenging problems in numerical optimization. We focus on the numerical solution of a stochastic model for option prices. In particular, we are concerned with the calibration of these models to real data, which leads to large scale optimization problems. We consider the numerical solution of these optimization problems and give some indication how to reduce the complexity of these problems. Special emphasis is devoted to a multi‐layer strategy which is embedded into the optimization iteration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and degradation of biomedical materials based on linear and star shaped polyglycidols
Authors: Keul Helmut , Möller Martin 
Published: May 2009

AbstractLinear and star shaped polyglycidols (synonym with polyglycerols) are prepared in a controlled ring opening polymerization of protected glycidols. Beside the molar mass and the polydispersity, the architecture of the polyglycidols is controlled by using mono‐ and multifunctional mono‐ and polydispers initiators. Copolymers of dissimilarly protected glycidols as well as copolymers with nonfunctional oxiranes were prepared by means of anionic polymerization while copolymers of protected glycidol with tetrahydrofuran were prepared by means of cationic polymerization. Polyethers with functional groups in the side chains (functional polyethers) with special emphasis on polyglycidols (containing hydroxymethyl groups in the side chains) were used to prepare multifunctional polymers and (hetero)grafted polymer brushes via chemical and enzyme catalyzed reaction. The potential of poly(glycidol‐graft‐ε‐caprolactone)‐co‐glycidol) prepared via enzyme catalyzed grafting of polyglycidols using ε‐caprolactone as a monomer and Lipase B from Candida antarctica as a catalyst is presented. Finally, comparative degradation studies of densely and loosely grafted polyglycidols are presented and discussed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3209–3231, 2009
Negative ion fragmentations of deprotonated peptides containing post‐translational modifications: diphosphorylated systems containing Ser, Thr and Tyr. A characteristic phosphate/phosphate cyclisation. A joint experimental and theoretical study
Authors: Andreazza Hayley J. , Wang Tianfang , Bilusich Daniel , Hoffmann Peter , Bowie John H. 
Published: May 2009

Abstract[M–H]− anions from small diphosphopeptides (phosphate groups on Ser, Thr or Tyr) show characteristic peaks corresponding to m/z 177 (H3P2O), 159 (HP2O) and sometimes [(M‐H)−–H4P2O7]−. M/z 177 and m/z 159 are major peaks in the spectra of small peptides with 1,2, 1,3, 1,4, 1,5 and 1,6 diphosphate substitution, which means that the decomposing [M–H]− anions must have flexible structures in order for the two phosphate groups to interact with each other. Peptides where the two phosphate groups are more than six amino acid residues apart have not been studied. Theoretical calculations indicate that m/z 177 is formed in a strongly exothermic reaction involving facile nucleophilic interaction between the two phosphate groups: m/z 159 is formed by loss of water from energised m/z 177. Copyright © 2009 John Wiley & Sons, Ltd.
Conformational changes in Akt1 activation probed by amide hydrogen/deuterium exchange and nano‐electrospray ionization mass spectrometry
Authors: Guo Mingquan , Huang Bill X. , Kim Hee‐Yong 
Published: May 2009

AbstractAmide hydrogen exchange coupled to nano‐electrospray ionization mass spectrometry (nano‐ESI‐MS) has been used to identify and characterize localized conformational changes of Akt upon activation. Active or inactive Akt was incubated in D2O buffer, digested with pepsin, and analyzed by nano‐ESI‐MS to determine the deuterium incorporation. The hydrogen/deuterium (H/D) exchange profiles revealed that Akt undergoes considerable conformational changes in the core structures of all three individual domains after activation. In the PH domain, four β‐strand (β1, β2 β5 and β6) regions containing membrane‐binding residues displayed higher solvent accessibility in the inactive state, suggesting that the PH domain is readily available for the binding to the plasma membrane for activation. In contrast, these β‐strands became less exposed or more folded in the active form, which is favored for the dissociation of Akt from the membrane. The beginning α‐helix J region and the C‐terminal locus (T450‐470P) of the regulatory domain showed less folded structures that probably enable substrate entry. Our data also revealed detailed conformational changes of Akt in the kinase domain due to activation, some of which may be attributed to the interaction of the basic residues with phosphorylation sites. Our H/D exchange results indicating the conformational status of Akt at different activation states provided new insight for the regulation of this critical protein involved in cell survival. Published in 2009 by John Wiley & Sons, Ltd.
Increasing physical function through physiatric intervention for children with paediatric neurotransmitter disorders
Authors: Evans S. , Forester K. , Pettiford J. M. , Morozova O. 
Published: May 2009

SummaryMost children with paediatric neurotransmitter diseases have global functional deficits secondary to central nervous system damage. Paediatric physiatrists, working in conjunction with a multi‐disciplinary team, help to improve physical function by normalizing muscle tone and improving body position. Components of spasticity, rigidity, and dystonia may all need to be considered in a comprehensive treatment programme. Complications of disordered tone include skin breakdown, pain, sleep disturbance, and dysphagia. With an integrated approach to use of medications and equipment as well as implementation of therapy and therapeutic exercise, physiatrists can help maximize functional independence for children with this group of disorders. Pharmacological treatment includes GABA‐agonists including baclofen and benzodiazepines, alpha‐2 adrenergic agonists, l‐dopa and dopaminergic agents, and dantrolene. Intrathecal baclofen may be used in patients refractory to these medications. In addition, physicians may utilize botulinum toxin, phenol, or surgical interventions such as selective dorsal rhizotomy or tendon lengthening. Pharmacological treatment must be used in conjunction with appropriate adaptive equipment in order to maximize therapeutic benefit. Focus on function in an attempt to increase independence is targeted to improve the child′s quality of life. We present a framework and rationale to the management of the functional consequences of the paediatric neurotransmitter diseases.
Keeping secrets from parents: Daily variations among poor, urban adolescents
Authors: Smetana Judith G. , Villalobos Myriam , Rogge Ronald D. , Tasopoulos‐Chan Marina 
Published: May 2009

ABSTRACTDaily variations in secrecy with mothers and fathers were examined in 108 poor, urban, diverse middle adolescents (M = 15.16 years, SD = 0.89). Adolescents completed online diaries over 14 days assessing secrecy from parents about school, personal, and multifaceted activities (e.g., staying out late), and bad behavior. Three‐level hierarchical linear models indicated that there were significant daily fluctuations in adolescents' secrecy with mothers and that adolescents kept more secrets from mothers about personal than other activities. Secrecy with mothers also was associated with greater involvement in problem behavior. For both mothers and fathers, secrecy on the current day was associated with greater secrecy on the previous day and with poorer overall relationships (as aggregated across study days) with that parent. Thus, for mothers, secrecy appeared to be associated with both stable factors and daily variations, whereas for fathers, secrecy was associated primarily with stable factors. The results provide a detailed picture of secrecy in diverse adolescents' everyday lives.
The New BAUS Section of Academic Urology: A Survey of the Urological Community
Authors: Nelson A.W. , Ahmad I. , Pickard R.S. , Leung H.Y. 
Published: May 2009

Objective: In 2007 the Section of Academic Urology was established as the fifth subspecialty section of the British Association of Urological Surgeons (BAUS). We conducted a survey of urologists and scientists involved in urological research in order to see how the new section could best serve the needs of the academic and clinical community. Materials and methods: A ten-part questionnaire was distributed to members of BAUS and BURST (British Urological Researchers in Training) via invitation, email and face-to-face contact. Results were collated using internet-based survey software. Results: Fifty-eight surveys were returned of which fifty-three (91.4%) were complete; forty-one respondents were career-grade clinicians, forty-six respondents were clinicians with prior research experience, forty respondents indicated a high level of interest in joining the academic section. Establishment of clinical research networks, face-to-face networking, contribution to scientific research in urology and provision of academic training emerged as priority areas for the section to address. Conclusions: Our survey population is a young and highly qualified group, with previous research experience and a desire to conduct further research. Priority areas for the new section to meet were highlighted, however a larger survey population, including non-clinical scientists would help to better establish the views of the wider urological community.
Parallel Imaging Artifacts in Body Magnetic Resonance Imaging
Authors: Noël Patricia , Bammer Roland , Reinhold Caroline , Haider Masoom A. 
Published: May 2009

Objective To familiarize the reader with the fundamental concepts of partial parallel imaging (PPI); to review the technical aspects of PPI including calibration scan, coil geometry, and field of view (FOV); and to illustrate artifacts related to parallel imaging and describe solutions to minimize their negative impact. Results PPI has led to a significant advance in body magnetic resonance imaging by reducing the time required to generate an image without loss of spatial resolution. Although PPI can improve image quality, it is not free of artifacts, which can result in significant image degradation. Knowledge of these artifacts and how to minimize their effect is important to optimize the use of parallel imaging for specific body magnetic resonance imaging applications. Conclusions The reader will be introduced to the fundamental principles of PPI. Common imaging characteristics of PPI artifacts will be displayed with an emphasis on those seen with image-based methods, the principles behind their generation presented, and measures to minimize their negative impact will be proposed.
Economical Elimination of Cycles in the Torus
Authors: ALON NOGA 
Published: May 2009

Let m > 2 be an integer, let C2m denote the cycle of length 2m on the set of vertices [−m, m) = {−m, −m + 1, . . ., m − 2, m − 1}, and let G = G(m, d) denote the graph on the set of vertices [−m, m)d, in which two vertices are adjacent if and only if they are adjacent in C2m in one coordinate, and equal in all others. This graph can be viewed as the graph of the d-dimensional torus. We prove that one can delete a fraction of at most $O(\frac{\log d}{m})$ of the vertices of G so that no topologically non-trivial cycles remain. This is tight up to the logd factor and improves earlier estimates by various researchers.