bluuebunny/crossref_metadata_2025_split huggingface dataset:
A parallel fully coupled algebraic multilevel preconditioner applied to multiphysics PDE applications: Drift‐diffusion, flow/transport/reaction, resistive MHD
Authors: Lin Paul T. , Shadid John N. , Tuminaro Raymond S. , Sala Marzio , Hennigan Gary L. , Pawlowski Roger P. 
Published: September 2010

AbstractThis study considers the performance of a fully coupled algebraic multilevel preconditioner for Newton–Krylov solution methods. The performance of the preconditioner is demonstrated on a set of challenging multiphysics partial differential equation (PDE) applications: a drift‐diffusion approximation for semiconductor devices; a low Mach number formulation for the simulation of coupled flow, transport and non‐equilibrium chemical reactions; and a low Mach number formulation for visco‐resistive magnetohydrodynamics (MHD) systems. These systems contain multiple physical mechanisms that are strongly coupled, highly nonlinear, non‐symmetric and produce solutions with multiple length‐ and time‐scales. In the context of this study the governing PDEs for these systems are discretized in space by a stabilized finite element (FE) method that collocates all unknowns at each node of the FE mesh. The algebraic multilevel preconditioner is based on an aggressive‐coarsening graph‐partitioning of the non‐zero block structure of the Jacobian matrix. The performance of the algebraic multilevel preconditioner is compared with a standard variable overlap additive Schwarz domain decomposition preconditioner. Representative performance and parallel scaling results are presented for a set of direct‐to‐steady‐state and fully implicit transient solutions. The performance studies include parallel weak scaling studies on up to 4096 cores and also includes the solution of systems as large as two billion unknowns carried out on 24000 cores of a Cray XT3/4. In general, the results of this study indicate that on this reasonably diverse set of challenging multiphysics applications the algebraic multilevel preconditioner performs very well. Copyright © 2010 John Wiley & Sons, Ltd.
A remedy for numerical oscillations in weakly compressible smoothed particle hydrodynamics
Authors: Fatehi R. , Manzari M. T. 
Published: September 2010

AbstractWeakly Compressible Smoothed Particle Hydrodynamics (WCSPH) can lead to non‐physical oscillations in the pressure and density fields when simulating incompressible flow problems. This in turn may result in tensile instability and sometimes divergence. In this paper, it is shown that this difficulty originates from the specific form of spatial discretization used for the pressure term when solving the mass conservation equation. After describing the pressure–velocity decoupling problem associated with the so‐called colocated grid methods, a modified approach is presented that overcomes this problem using a different discretization scheme for the second derivative of pressure. The modified scheme is employed for solving a number of benchmark problems including both single‐phase and two‐phase test cases. Copyright © 2010 John Wiley & Sons, Ltd.
Numerical and analytical solutions of an Oldroyd 8‐constant MHD fluid with nonlinear slip conditions
Authors: Hameed M. , Ellahi R. 
Published: September 2010

SUMMARYThe flow of an Oldroyd 8‐constant non‐Newtonian MHD fluid is investigated analytically and numerically. The governing equations for the flow field are derived for a steady one‐dimensional flow. The effect of constant applied magnetic field is included and its influence on the flow field is studied. The nonlinear governing equation along with nonlinear boundary conditions is solved analytically and the solution is obtained in an elegant way. Numerical solutions are also obtained using higher order Chebyshev spectral methods. The influence of various non‐Newtonian parameters and applied magnetic field is investigated. Results showing the effect of various physical parameters of the flow are presented and investigated. Copyright © 2010 John Wiley & Sons, Ltd.
Polysomnographic diagnosis of idiopathic REM sleep behavior disorder
Authors: Montplaisir Jacques , Gagnon Jean‐Francois , Fantini Maria Livia , Postuma Ronald B. , Dauvilliers Yves , Desautels Alex , Rompré Sylvie , Paquet Jean 
Published: September 2010

AbstractThe presence of either excessive tonic chin EMG activity during REM sleep, or excessive phasic submental or limb EMG twitching is required to diagnose REM sleep behavior disorder (RBD). The aim was to identify cut‐off values and to assess the sensitivity and specificity of these values taken separately or combined to diagnose idiopathic RBD patients. Eighty patients presenting with a clinical diagnosis of idiopathic RBD and 80 age‐ and gender‐matched normal controls were studied in the sleep laboratory. Receiver operating characteristic curves were drawn to find optimal cut‐off values for three REM sleep EMG parameters. Tonic and phasic EMG activity were measured in the chin, but not in the limbs. Videos were examined during the recording but were not systematically reviewed by the authors. Total correct classification of 81.9% was found for tonic chin EMG density ≥30%; 83.8% for phasic chin EMG density ≥15% and 75.6% for ≥24 leg movements per hour of REM sleep. Five patients did not fulfill any of these three polysomnographic (PSG) criteria. Conversely, one subject of the control group met the PSG criteria for RBD. This study estimates the diagnostic value of a visual scoring method for the diagnosis of idiopathic RBD and establishes cut‐off values to be used in clinical and research set‐ups. For the five RBD patients who did not show chin EMG abnormalities, it cannot be excluded that they had increased phasic EMG activity in the upper limbs and presented visible motor activity. © 2010 Movement Disorder Society
Grasping premanifest Huntington's disease – shaping new endpoints for new trials
Authors: Reilmann Ralf , Bohlen Stefan , Klopstock Thomas , Bender Andreas , Weindl Adolf , Saemann Philipp , Auer Dorothee P. , Ringelstein Erich B. , Lange Herwig W. 
Published: September 2010

AbstractFuture clinical trials in subjects with premanifest Huntington's disease (preHD) may depend on the availability of biomarkers. It was previously shown in symptomatic HD that, the grip force variability coefficient‐of‐variation (GFV‐C) in a grasping paradigm was correlated to the Unified‐Huntington's‐Disease‐Rating‐Scale‐Total‐Motor‐Score (UHDRS‐TMS) and increased in a 3 year follow‐up study. To further elucidate its potential as a biomarker, we investigated whether GFV‐C is able to detect a motor phenotype in preHD and is correlated to the genotype assessed by a disease‐burden‐score. The ability of preHD (n = 15) and symptomatic HD subjects (n = 20) to maintain stable grip forces, while holding an object (250 g and 500 g), was measured and compared with the controls (n = 19). GFV‐C was increased in preHD at 500 g, in symptomatic subjects at both weights and was correlated to the disease‐burden‐score and UHDRS‐TMS. GFV‐C may be a useful objective and quantitative marker of motor dysfunction across genetically diagnosed premanifest and symptomatic HD subjects. © 2010 Movement Disorder Society
Brain stem pathology in Parkinson's disease: An evaluation of the Braak staging model
Authors: Kingsbury Ann E. , Bandopadhyay Rina , Silveira‐Moriyama Laura , Ayling Hilary , Kallis Constantinos , Sterlacci William , Maeir Hans , Poewe Werner , Lees Andrew J. 
Published: September 2010

AbstractThe lower brain stem of 25 pathologically‐confirmed Parkinson's disease (PD) cases was examined by alpha synuclein immunohistochemistry to characterize pathological accumulation of alpha synuclein (Lewy‐type α‐synucleinopathy, LTS) in the medulla oblongata, to examine differences between affected regions and test a proposed model of staging of pathology in PD. All cases had LTS in the medulla, including the dorsal motor nucleus of the vagus (dmX), when present. The distribution followed a consistent pattern and appeared to be concentrated in a tyrosine hydroxylase (TH) immunoreactive region, probably representing the dorsal IX/X nuclear complex and the intermediate reticular zone. LTS density was greatest in the dmX. A similar distribution pattern to PD was seen in 14 incidental Lewy body disease (ILBD) cases, five derived from the Queen Square Brain Bank tissue collection and nine identified in separate series of 60 neurologically‐normal individuals, and in three cases with the G2019S mutation of LRRK2. Semiquantitative assessment showed that severity of pathology in the dmX was not correlated with the severity of cortical pathology. Semiquantitative assay of TH and ChAT peptide expression in the medulla showed that TH expression in PD and ILBD did not differ from controls. These findings broadly support the Braak hypothesis of caudo‐rostral development but indicate that the extent of the disease in the cortex and the severity of pathology in the medulla were independent of one another. © 2010 Movement Disorder Society
Impaired postural stability as a marker of premanifest Huntington's disease
Authors: Salomonczyk Danielle , Panzera Robert , Pirogovosky Eva , Goldstein Jody , Corey‐Bloom Jody , Simmons Roger , Gilbert Paul E. 
Published: September 2010

AbstractSubtle changes in fine motor control have been observed in individuals who carry the Huntington's disease (HD) mutation but have not yet manifested symptoms, referred to as premanifest HD (preHD). However, few studies have examined gross motor impairments in this population. This study sought to examine the role of sensory involvement in maintaining postural stability during the premanifest and manifest stages of HD using computerized dynamic posturography. Eleven HD participants, 22 preHD subdivided into “preHD Near” (<5 years from estimated clinical onset) and “preHD Far” (>5 years from estimated clinical onset), and 17 nongene carriers (NGC) completed a sensory organization test (SOT) to assess postural control when vestibular, visual, and somatosensory information was systematically degraded. The HD group demonstrated greater postural sway than the NGC and preHD Far groups on all conditions including baseline, and greater postural sway than the preHD Near group when sensory information was manipulated. The preHD Near group showed significantly greater postural sway than the preHD Far group when visual and somatosensory information was degraded and only vestibular information was available and reliable for maintaining postural stability. The results of this study highlight subtle postural deficits in the face of changing sensory conditions in preHD up to 5 years before estimated disease onset. The findings suggest that the SOT may be a highly sensitive indicator of early motor impairment and subsequent phenoconversion to manifest HD in preHD. © 2010 Movement Disorder Society
Clinical course of the first Asian family with Parkinsonism related to SNCA triplication
Authors: Sekine Takeshi , Kagaya Hajime , Funayama Manabu , Li Yuanzhe , Yoshino Hiroyo , Tomiyama Hiroyuki , Hattori Nobutaka 
Published: September 2010

AbstractTriplication of SNCA is a rare cause of familial Parkinson's disease compared with duplication. Its clinical course is believed to be more robust than duplication, though it is uncertain. Marked as the first among the Asian population, we identified a Japanese family (paternal grandfather, father, and son) with SNCA triplication based on genetic and clinical analyses. The proband had a completely triplicated region including SNCA. This allele did not share any common haplotypes with those of previously reported Japanese families with SNCA duplication. Clinical analysis indicated early onset, rapidly progressive parkinsonism with mild levodopa response. Further studies are needed to clarify the gene dose effect of SNCA. © 2010 Movement Disorder Society
Spinocerebellar ataxia type 10: Frequency of epilepsy in a large sample of Brazilian patients
Authors: Teive Hélio A.G. , Munhoz Renato P. , Raskin Salmo , Arruda Walter O. , de Paola Luciano , Werneck Lineu C. , Ashizawa Tetsuo 
Published: September 2010

AbstractSpinocerebellar ataxia type 10 (SCA10) is an autosomal dominant disorder caused by an ATTCT repeat intronic expansion in the SCA10 gene. SCA 10 has been reported in Mexican, Brazilian, Argentinean and Venezuelan families. Its phenotype is overall characterized by cerebellar ataxia and epilepsy. Interestingly, Brazilian patients reported so far showed pure cerebellar ataxia, without epilepsy. Here, authors provide a systematic analysis of the presence, frequency and electroencephalographic presentation of epilepsy among 80 SCA10 patients from 10 Brazilian families. Overall, the frequency of epilepsy was considered rare, been found in 3.75 % of the cases while this finding in populations from other geographic areas reaches 60% of SCA10 cases. © 2010 Movement Disorder Society
Olfactory heterogeneity in LRRK2 related Parkinsonism
Authors: Silveira‐Moriyama Laura , Munhoz Renato Pupi , de J. Carvalho Margarete , Raskin Salmo , Rogaeva Ekaterina , de C. Aguiar Patricia , Bressan Rodrigo A. , Felicio Andre C. , Barsottini Orlando G.P. , Andrade Luiz Augusto F. , Chien Hsin F. , Bonifati Vincenzo , Barbosa Egberto R. , Teive Helio A. , Lees Andrew J. 
Published: September 2010

AbstractLRRK2 mutations can cause familial and sporadic Parkinson's disease (PD) with Lewy‐body pathology at post‐mortem. Studies of olfaction in LRRK2 are sparse and incongruent. We applied a previously validated translation of the 16 item smell identification test from Sniffin' Sticks (SS‐16) to 14 parkinsonian carriers of heterozygous G2019S LRRK2 mutation and compared with 106 PD patients and 118 healthy controls. The mean SS‐16 score in LRRK2 was higher than in PD (p < 0.001, 95% CI for β = −4.7 to −1.7) and lower than in controls (p = 0.007, 95% CI for β = +0.6 to +3.6). In the LRRK2 group, subjects with low scores had significantly more dyskinesia. They also had younger age of onset, longer disease duration, and reported less frequently a family history of PD, but none of these other differences reached significance. Odor identification is diminished in LRRK2 parkinsonism but not to the same extent as in idiopathic PD. © 2010 Movement Disorder Society
How well do caregivers detect mild cognitive change in Parkinson's disease?
Authors: Naismith Sharon L. , Pereira Marilia , Shine James M. , Lewis Simon J.G. 
Published: September 2010

AbstractUsing the Cambridge Behavior Inventory‐Revised, this study evaluated the relationship between caregiver ratings of cognitive change and neuropsychological performance. In sixty‐one nondemented patients with Parkinson's Disease (PD; mean age = 64.5 years, MMSE = 28.7), 62% met criteria for mild cognitive impairment. This group were rated as having more overall change as well as memory and behavior change. Caregiver ratings were related to poorer psychomotor speed, learning/memory, language, and executive functioning. The capacity for caregivers to rate mild cognitive change in PD may be useful to assist in early screening and intervention approaches. © 2010 Movement Disorder Society
Partial cranial trephination by means of Hippocrates' trypanon from 5th century BC Himera (Sicily, Italy)
Authors: Fabbri P. F. , Lonoce N. , Masieri M. , Caramella D. , Valentino M. , Vassallo S. 
Published: September 2010

AbstractThe paper deals with a new case of partial cranial trephination found in one of the necropolises of the Greek colony of Himera in Sicily. It is one of the very few cases of cranial trephination of Greek classical age. Macroscopic as well as radiological investigations prove that the operation was perimortal as no growth of new bone could be detected, SEM‐EDS microanalysis of the piece revealed the traces left by the tool used during trephination. The review of ancient Greek and Latin medical and surgical texts permitted us to establish that the tool used in Himera was a (trypanon) mentioned by Hippocrates and named terebra by Latin authors. Copyright © 2010 John Wiley & Sons, Ltd.
Formation and decomposition of N‐alkylnaphthalimides: experimental evidences and ab initio description of the reaction pathways
Authors: de Barros Teresa Cristina , Filho Pedro Berci , Loos Michel , Politi Mario José , Chaimovich Hernan , Cuccovia Iolanda Midea 
Published: September 2010

AbstractThe kinetics of hydrolysis of 1,8‐N‐butyl‐naphthalimide (1,8‐NBN) to 1,8‐N‐butyl‐naphthalamide (1,8‐NBAmide) and of 2,3‐N‐butyl‐naphthalimide (2,3‐NBN) to 2,3‐N‐butyl‐naphthalamide (2,3‐NBAmide), as well as the formation of the respective anhydrides from the amides were investigated in a wide acidity range. 1,8‐NBN equilibrates with 1,8‐NBAmide in mild alkali. Under the same conditions 2,3‐NBN quantitatively yields 2,3‐NBAmide. Over a wide range of acidities the reactions of the 1,8‐ and 2,3‐N‐butyl‐naphthalamides (or imides) yield similar products but with widely different rates and at distinct pH's. Anhydride formation in acid was demonstrated for 1,8‐NBAmide. The reactions mechanisms were rationalized in the manifold pathways of ab initio calculations. The differences in rates and pH ranges in the reactions of the 1,8‐ and 2,3‐N‐butyl‐naphthalamides were attributed to differences in the stability of the tetrahedral intermediates in alkali as well as the relative stabilities of the five and six‐membered ring intermediates. The rate of carboxylic acid assisted 1,8‐N‐Butyl‐naphthalamide hydrolysis is one of the largest described for amide hydrolysis models. Copyright © 2010 John Wiley & Sons, Ltd.
Geometrically centered region: A “wet” model of protein binding hot spots not excluding water molecules
Authors: Li Zhenhua , Li Jinyan 
Published: September 2010

AbstractA protein interface can be as “wet” as a protein surface in terms of the number of immobilized water molecules. This important water information has not been explicitly taken by computational methods to model and identify protein binding hot spots, overlooking the water role in forming interface hydrogen bonds and in filing cavities. Hot spot residues are usually clustered at the core of the protein binding interfaces. However, traditional machine learning methods often identify the hot spot residues individually, breaking the cooperativity of the energetic contribution. Our idea in this work is to explore the role of immobilized water and meanwhile to capture two essential properties of hot spots: the compactness in contact and the far distance from bulk solvent. Our model is named geometrically centered region (GCR). The detection of GCRs is based on novel tripartite graphs, and atom burial levels which are a concept more intuitive than SASA. Applying to a data set containing 355 mutations, we achieved an F measure of 0.6414 when ΔΔG ≥ 1.0 kcal/mol was used to define hot spots. This performance is better than Robetta, a benchmark method in the field. We found that all but only one of the GCRs contain water to a certain degree, and most of the outstanding hot spot residues have water‐mediated contacts. If the water is excluded, the burial level values are poorly related to the ΔΔG, and the model loses its performance remarkably. We also presented a definition for the O‐ring of a GCR as the set of immediate neighbors of the residues in the GCR. Comparative analysis between the O‐rings and GCRs reveals that the newly defined O‐ring is indeed energetically less important than the GCR hot spot, confirming a long‐standing hypothesis. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Surface and electrochemical analysis for the understanding of TiO2 nanopores/nanotubes changes in post‐elaboration treatment
Authors: Manole Claudiu Constantin , Pirvu Cristian 
Published: September 2010

AbstractThe electrochemical stability of TiO2 nanoarchitecture fabricated in fluoride electrolyte presented in this paper is related to 2D and 3D geometries that present a shift from nanopores toward nanotubes. The fabrication conditions involve a 60 V applied voltage for 2 hours of anodizing in order to create the ordered structures, in a mixture of low‐water glycerol electrolyte and fluoride. With the use of different ultrasonication times, a variety of nanotubes/nanopores were observed. The surface interfacial aspects were investigated mainly by surface microscopy and hydrophilic/hydrophobic balance for the grown structures ultrasonicated at various periods of time. The electrochemical behavior of the nanotube‐structured surface was performed by potentiodynamic evaluation and electrochemical impedance spectroscopy in a simulated body fluid solution. As a most important result, all surface analysis and electrochemical data interpretation permitted the proposition of a model for elaboration of different nanostructures from nanopores to nanotubes. These different surface nanoarchitectures were obtained as a result of ultrasonication at various periods of time. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of anodic spark oxidation by pulse power on titanium substrates
Authors: Park Il Song , Lee Min Ho 
Published: September 2010

AbstractThe characteristics of the oxide layer of titanium generated by anodic spark oxidation are affected significantly by the process variables. In this study, electrochemical treatments were performed while applying a direct current, a pulse current, and a reverse pulse current during anodic spark oxidation. A mixed solution of 0.015 M DL‐α‐GP (DL‐α‐glycerophosphate disodium salt) and 0.2 M CA (calcium acetate) was used as the electrolyte. The pore size generated after anodic spark oxidation was smallest in the group exposed to the reverse pulse current followed in order by the pulse current and direct current. Anatase was the major crystal phase of the TiO2 produced on the surfaces subjected to 280 V, and the rutile phase was additionally detected in the group subjected to 320 V. The crystals precipitated on the surface after the hydrothermal treatment were hydroxyapatite (HA) crystals that had a polygonal bar‐shaped needle structure. Good activity was observed in the 320‐V pulse treated group, in which very thin needle‐shaped crystals were observed after immersing the samples in Hanks' solution for 4 weeks. The cell viability was increased greatly by anodic spark oxidation, and the surface roughness was also increased. It is believed that the surface treated using a pulse current has excellent characteristics, making it suitable for applications in biomaterials. Copyright © 2010 John Wiley & Sons, Ltd.