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Translational
Terms modified by Translational Selected Abstracts3D coronary motion tracking in swine models with MR tracking cathetersJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2009Ehud J. Schmidt PhD Abstract Purpose To develop MR-tracked catheters to delineate the three-dimensional motion of coronary arteries at high spatial and temporal resolution. Materials and Methods Catheters with three tracking microcoils were placed into nine swine. During breath-holds, electrocardiographic (ECG)-synchronized 3D motion was measured at varying vessel depths. 3D motion was measured in American Heart Association left anterior descending (LAD) segments 6,7, left circumflex (LCX) segments 11,15, and right coronary artery (RCA) segments 2,3, at 60,115 beats/min heart rates. Similar-length cardiac cycles were averaged. Intercoil cross-correlation identified early systolic phase (ES) and determined segment motion delay. Results Translational and rotational motion, as a function of cardiac phase, is shown, with directionality and amplitude varying along the vessel length. Rotation (peak-to-peak solid-angle RCA ,0.10, LAD ,0.06, LCX ,0.18 radian) occurs primarily during fast translational motion and increases distally. LCX displacement increases with heart rate by 18%. Phantom simulations of motion effects on high-resolution images, using RCA results, show artifacts due to translation and rotation. Conclusion Magnetic resonance imaging (MRI) tracking catheters quantify motion at 20 fps and 1 mm3 resolution at multiple vessel depths, exceeding that available with other techniques. Imaging artifacts due to rotation are demonstrated. Motion-tracking catheters may provide physiological information during interventions and improve imaging spatial resolution. J. Magn. Reson. Imaging 2009;29:86,98. © 2008 Wiley-Liss, Inc. [source] Translational and transcriptional analysis of Sulfolobus solfataricus P2 to provide insights into alcohol and ketone utilisationPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 3 2007Poh Kuan Chong Abstract The potential of Sulfolobus solfataricus P2 for alcohol or ketone bioconversion was explored in this study. S. solfataricus was grown in different concentrations (0.1,0.8% w/v) of alcohols or ketones (ethanol, iso-propanol, n -propanol, acetone, phenol and hexanol) in the presence of 0.4% w/v glucose. Consequently, the addition of these alcohols or ketones into the growth media had an inhibitory effect on biomass production, whereby lag times increased and specific growth rates decreased when compared to a glucose control. Complete glucose utilisation was observed in all cultures, although slower rates of glucose consumption were observed in experimental cultures (average of 14.9,mg/L/h compared to 18.9,mg/L/h in the control). On the other hand, incomplete solvent utilisation was observed, with the highest solvent consumption being approximately 51% of the initial concentration in acetone cultures. Translational responses of S. solfataricus towards these alcohols or ketones were then investigated using the isobaric tags for relative and absolute quantitation (iTRAQ) technique. The majority (>80%) of proteins identified and quantified showed no discernable changes in regulation compared to the control. These results, along with those obtained from transcriptional analysis of key genes involved within this catabolic process using quantitative RT-PCR and metabolite analysis, demonstrate successful alcohol or ketone conversion in S. solfataricus. [source] Facilitating Emergency Care Research Networks: Integration into the Clinical Translational and Science Award (CTSA) InfrastructureACADEMIC EMERGENCY MEDICINE, Issue 10 2009Judd E. Hollander MD Abstract Emergency care research (ECR) does not fit neatly into the traditional National Institutes of Health (NIH) funding model, because emergency research involves undifferentiated disease presentations involving multiple disciplines and time-sensitive interventions. A task force of emergency care researchers and other stakeholders was convened to discuss the present and future state of clinical research networks. Integration of ECR with the Clinical Translational and Science Award (CTSA) program through a multidisciplinary emergency care research network (ECRN) would obviate the duplication of research efforts by disease-specific or institute-specific multicenter networks and reduce startup and maintenance costs. Strategies to enhance integration must include the training of emergency physician investigators in biostatistical and epidemiologic methods, as well as educating collaborative investigators in emergency care,related methodologies. Thus, an ECRN would be of great benefit to CTSA awardees and applicants and should be considered a priority. [source] Exendin-4 protects pancreatic beta cells from human islet amyloid polypeptide-induced cell damage: potential involvement of AKT and mitochondria biogenesisDIABETES OBESITY & METABOLISM, Issue 9 2010R. Fan Aim: Glucagon-like peptide-1 (GLP-1) stimulates beta-cell proliferation and enhances beta-cell survival, whereas oligomerization of human islet amyloid polypeptide (hIAPP) may induce beta-cell apoptosis and reduce beta-cell mass. Type 2 diabetes is associated with increased expression of IAPP. As GLP-1-based therapy is currently developed as a novel antidiabetic therapy, we examined the potential protective action of the GLP-1 receptor agonist exendin-4 on hIAPP-induced beta-cell apoptosis. Methods: The study was performed in clonal insulinoma (INS-1E) cells. Both method of transcriptional and translational and sulphorhodamine B (SRB) assays were used to evaluate cell viability and cell mass. Western blot analysis was applied to detect protein expression. Transfection of constitutively active protein kinase B (PKB/AKT) was performed to examine the role of AKT. Mitochondrial biogenesis was quantified by mitogreen staining and RT-PCR. Results: First, we confirmed that hIAPP induced cell apoptosis and growth inhibition in INS-1E cells. These effects were partially protected by exendin-4 in association with partial recovery of the hIAPP-mediated AKT inhibition. Furthermore, AKT constitutive activation attenuated hIAPP-induced apoptosis, whereas PI3K/AKT inhibition abrogated exendin-4-mediated effects. These findings suggest that the antiapoptotic and proliferative effects of exendin-4 in hIAPP-treated INS-1E cells were partially mediated through AKT pathway. Moreover, hIAPP induced FOXO1 but inhibited pdx-1 nucleus translocation. These effects were restored by exendin-4. Finally, mitogreen staining and RT-PCR revealed enhanced mitochondrial biogenesis by exendin-4 treatment. Conclusions: Collectively, these results suggest that GLP-1 receptor agonist protects beta cells from hIAPP-induced cell death partially through the activation of AKT pathway and improved mitochondrial function. [source] CNS response to a thermal stressor in human volunteers and rats may predict the clinical utility of analgesicsDRUG DEVELOPMENT RESEARCH, Issue 1 2007David Borsook Abstract fMRI was used to test the hypothesis that global brain activation following a stressor (a thermal stimulus) that activates multiple brain circuits in healthy subjects can predict which drugs have higher potential for clinical utility for neuropathic pain. The rationale is that a drug will modulate multiple neural circuits that are activated by the system-specific stressor (e.g., pain). In neuropathic pain, some brain circuits have altered function, but most brain systems are "normal." Thus, the manner in which a drug effect on neural circuits is modulated by the stressor may provide insight into the clinical utility based on the readout of brain activation in response to the stimulus. Six drugs with known clinical efficacy (or lack thereof) in treating neuropathic pain were selected and the CNS response to each drug in the presence or absence of a pain stimulus was examined. The present results suggest that it is possible to identify potentially effective drugs based on patterns of brain activation in healthy human subjects and indicate that CNS activity is a more sensitive measure of drug action than standard psychophysical measures of pain intensity. This approach was repeated in rats and showed that a similar fMRI paradigm segregates these drugs in a similar manner suggesting a potential "translational tool" in evaluating drug efficacy for neuropathic pain. The sensitivity of this paradigm using fMRI allows clinical screening in small groups of healthy subjects, suggesting it could become a useful tool for drug development as well as for elucidating the mechanisms of neuropathic disease and therapy. Drug Dev. Res. 68:23,41, 2007. © 2007 Wiley-Liss, Inc. [source] Shake table tests on a mass eccentric model with base isolationEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 9 2003Bijan Samali Abstract A mass eccentric structure is usually more seismically vulnerable than its concentric counterpart because of the coupled torsional,translational response of such structures. In this work, dynamic characteristics and response of a five-storey benchmark model with moderate mass eccentricity were investigated using a shake table, simulating four different ground motions. The effectiveness of laminated rubber bearings (LRB) and lead-core rubber bearings (LCRB) in protecting eccentric structures was examined and evaluated in relation to translational and torsional responses of the benchmark model. It was observed that both translational and torsional responses were significantly reduced with the addition of either a LRB or LCRB isolated system regardless of the nature of ground motion input. The LRB were identified to be more effective than LCRB in reducing model relative displacements, the relative torsional angle as well as accelerations, and therefore provided a better protection of the superstructure and its contents. On the other hand, LCRB rendered a smaller torsional angle and absolute displacement of the base isolation system, hence a more stable structural system. Copyright © 2003 John Wiley & Sons, Ltd. [source] Analysis of electrokinetic transport of a spherical particle in a microchannelELECTROPHORESIS, Issue 4 2007Harikrishnan N. Unni Abstract Electrokinetically driven microfluidic devices that are used for biological cell/particle manipulation (e.g., cell sorting, separation) involve electrokinetic transport of these particles in microchannels whose dimension is comparable with particles' size. This paper presents an analytical study on electrokinetic transport of a charged spherical particle in a charged parallel-plate microchannel. Under the thin electric double-layer assumption, solutions in closed-form solutions for the particle velocity and disturbed electrical and fluid velocity fields are obtained for plane-symmetric (along the channel centerline) and asymmetric (off the channel centerline) motions of a sphere in a parallel-plate microchannel. The effects of relative particle size and eccentricity (i.e., off the centerline distance) on a particle's translational and rotational velocities are analyzed. [source] Remission induction, consolidation and novel agents in development for adults with acute myeloid leukaemiaHEMATOLOGICAL ONCOLOGY, Issue 1 2010Mehdi Hamadani Abstract Chemotherapy regimens used for remission induction in AML have not changed significantly over the last several decades. However the recognition of the prognostic value of cytogenetics and genomics has been a major advance which is helping clarify the most optimal post-remission consolidation strategy among various risk groups. We are not only beginning to realize the pitfalls of a ,one-fits-all' approach with intensive, cytarabine-based chemotherapy as the mainstay, but we are finally beginning to reap the rewards of decades of basic, translational, and clinical research. Developing individualized, ,targeted' therapy for each AML patient based on unique molecular features of disease remains a daunting goal yet one that we can now begin to envision. Hypothesis-based study designs,from pre-clinical/laboratory experiments to phase-I and subsequent efficacy trials,provide the foundation for advances in the diagnosis, risk stratification, and treatment for patients with AML. Here we critically review the literature for the management of AML, try to give recommendations regarding the appropriate induction and remission strategy, clarify the role of stem cell transplantation and discuss novel agents on the horizon. Copyright © 2009 John Wiley & Sons, Ltd. [source] Synaptophysin protein and mRNA expression in the human hippocampal formation from birth to old age,HIPPOCAMPUS, Issue 8 2006Sharon L. Eastwood Abstract In the human neocortex, progressive synaptogenesis in early postnatal life is followed by a decline in synaptic density, then stability from adolescence until middle age. No comparable data are available in the hippocampus. In this study, the integral synaptic vesicle protein synaptophysin, measured immunoautoradiographically, was used as an index of synaptic terminal abundance in the hippocampal formation of 37 subjects from 5 weeks to 86 yr old, divided into 4 age groups (10 infants, 15 adolescents/young adults, 6 adults, and 6 elderly). In all hippocampal subfields, synaptophysin was lowest in infancy, but did not differ significantly between the older age groups, except in dentate gyrus (DG) where the rise was delayed until adulthood. A similar developmental profile was found in the rat hippocampus. We also measured synaptophysin mRNA in the human subjects and found no age-related changes, except in parahippocampal gyrus wherein the mRNA declined from infancy to adolescence, and again in old age. The synaptophysin protein data demonstrate a significant presynaptic component to human postnatal hippocampal development. In so far as synaptophysin abundance reflects synaptic density, the findings support an increase in hippocampal and parahippocampal synapse formation during early childhood, but provide no evidence for adolescent synaptic pruning. The mRNA data indicate that the maturational increases in synaptophysin protein are either translational rather than transcriptional in origin, or else are secondary to mRNA increases in neurons, the cell bodies of which lie outside the hippocampal formation. Published 2006 Wiley-Liss, Inc. [source] Kinematic and dynamic analysis of open-loop mechanical systems using non-linear recursive formulationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 12 2006Yunn-Lin Hwang Abstract In this paper, a non-linear recursive formulation is developed for kinematic and dynamic analysis of open-loop mechanical systems. The non-linear equations of motion are developed for deformable links that undergo large translational and rotational displacements. These equations are formulated in terms of a set of time invariant scalars and matrices that depend on the spatial co-ordinates as well as the assumed displacement field, and these time invariant quantities represent the dynamic coupling between the rigid-body modes and elastic deformations. A new recursive formulation is presented for solving equations of motion for open-loop chains consisting of interconnected rigid and deformable open-loop mechanical systems. This formulation is expressed by the recursive relationships and the generalized non-linear equations for deformable mechanical systems to obtain a large system of loosely coupled equations of motion. The main processor program consists of three main modules: constraint module, mass module and force module. The constraint module is used to numerically evaluate the relationship between the absolute and joint accelerations. The mass module is used to numerically evaluate the system mass matrix as well as the non-linear Coriolis and centrifugal forces associated with the absolute, joint and elastic co-ordinates. Simultaneously, the force module is used to numerically evaluate the generalized external and elastic forces associated with the absolute, joint and elastic co-ordinates. Computational efficiency is achieved by taking advantage of the structure of the resulting system of loosely coupled equations. The solution techniques used in this investigation yield a much smaller operations count and can more efficiently implement in any computer. The algorithms and solutions presented in this paper are illustrated by using an industrial robotic manipulator system. The numerical results using this formulation are also presented and discussed in this paper. Copyright © 2006 John Wiley & Sons, Ltd. [source] A method for representing boundaries in discrete element modelling,part I: Geometry and contact detectionINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 12 2001M. Kremmer Abstract The discrete element method for analysis of the dynamic behaviour of discontinuous media is well established. However, its application to engineering problems is still limited to simplified representations of structural boundaries and their kinematics. In this paper a method is developed for representing three-dimensional boundaries of arbitrary geometry and for modelling the interaction between boundary objects and particles within the discrete element modelling framework. The approach, which we term the finite wall method, uses planar triangular elements to approximate the boundary surface topology. Any number of wall elements can be used to model the shape of the structure. A contact detection scheme is presented for boundary surfaces and spheres based on a series of vector projections to reduce the problem dimensionally. The algorithm employs spatial sporting to obtain the set of potential contacts between spheres and wall elements prior to contact resolution. In a further stage, all possible contact conditions including contact with surfaces, edges and corners are explicitly determined. Part I of this two-part series of papers describes the finite wall method for representation of surface geometry and fully elaborates the method for detecting and resolving contact between boundary wall elements and spheres. In Part II the finite wall method is extended to apply kinematics to linearly independent boundary objects using combinations of translational and rotational motion. An approach is developed for coupling the DEM with the FEM for the purpose of optimising the design of structures which are dynamically interacting with particulate media. Copyright © 2001 John Wiley & Sons, Ltd. [source] Update on peptidylarginine deiminases and deimination in skin physiology and severe human diseasesINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 3 2007M.-C. Méchin Synopsis Deimination (or citrullination) is a recently described post-translational modification, but its consequences are not yet well understood. It is catalysed by peptidylarginine deiminases (PADs). These enzymes transform arginyl residues involved in a peptidyl link into citrullyl residues in a calcium-dependent manner. Several PAD substrates have already been identified like filaggrin and keratins K1 and K10 in the epidermis, trichohyalin in hair follicles, but also ubiquitous proteins like histones. PADs act in a large panel of physiological functions as cellular differentiation or gene regulation. It has been suggested that deimination plays a role in many major diseases such as rheumatoid arthritis, multiple sclerosis, Alzheimer's disease and psoriasis. Five human genes (PADIs), encoding five highly conserved paralogous enzymes (PAD1-4 and 6), have been characterized. These genes are clustered in a single locus, at 1p35-36 in man. Only PAD1-3 are expressed in human epidermis. PADs seem to be controlled at transcriptional, translational and activity levels and they present particular substrate specificities. In this review, we shall discuss these main biochemical, genetic and functional aspects of PADs together with their pathophysiological implications. Résumé La désimination (ou citrullination) est une modification post-traductionnelle catalysée par les peptidyl-arginine désiminases (PADs), décrite depuis peu et dont les conséquences sont encore mal comprises. Ces enzymes transforment, de façon dépendante du calcium, les résidus arginyl engagés dans un lien peptidique en résidus citrullyl. Plusieurs substrats ont été identifiés: la filaggrine et les cytokératines K1 et K10 de l'épiderme, la trichohyaline dans le follicule pileux mais aussi des protéines ubiquistes comme les histones. Les PADs interviennent dans de nombreuses fonctions physiologiques telles que la différenciation cellulaire ou la régulation génique. La désimination pourrait jouer un rôle dans plusieurs maladies sévères et fréquentes comme la polyarthrite rhumatoïde, la sclérose en plaque, la maladie d'Alzheimer ou encore le psoriasis. Cinq gènes humains (PADIs) codant pour 5 enzymes paralogues conservées (PAD1-4 et 6) ont été caractérisés. Ils sont regroupés en un seul locus, en 1p35-36 chez l'homme. Seules les PAD1-3 sont exprimées dans l'épiderme humain. Les PADs semblent contrôlées aux niveaux transcriptionnel et traductionnel, ainsi qu'au niveau de leur activité. Elles présentent chacune leurs spécificités de substrats. Ces principaux aspects biochimiques, génétiques et fonctionnels des PADs tout comme leurs implications physiopathologiques seront discutés dans cette revue. [source] Translational approaches to understanding anorexia nervosaINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue S1 2005Diane A. Klein MD Abstract Translational research has fostered significant gains in neuroscience and psychiatry and has been identified by the NIMH as a "priority area" for further funding. As applied to anorexia nervosa (AN), "translational research" describes the application of principles and methodologies employed in related fields to advance the understanding, and ultimately treatment and prevention, of this disorder. Several promising areas of translational research in AN are identified. Such research, particularly when linked to a conceptual framework, offers the potential of lending much-needed novel insight into this challenging and enigmatic disorder. © 2005 by Wiley Periodicals, Inc. [source] Development of analytic energy gradient method in nuclear orbital plus molecular orbital theoryINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 14 2007Minoru Hoshino Abstract This study formulates the analytic energy gradients in the Hartree-Fock calculations of the NOMO theory, which simultaneously determines nuclear and electronic wave functions without the Born-Oppenheimer approximation. The formulations correspond to the translation- and rotation-contaminated (TRC), translation-free (TF), and translation- and rotation-free (TRF) treatments. The optimizations of the orbital centers for several diatomic molecules, which have been performed by using the analytic energy gradients, have given the averaged nuclear distances {R0} reflecting the quantum effects of nuclei and the anharmonicity of the potential energy surfaces. The numerical assessments have clarified that the effects of eliminating the translational and rotational contaminations, i.e., the TRF effects are important to improve the evaluations of {R0}, especially for the molecules including hydrogen atoms. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [source] Osteoclastogenesis, Bone Resorption, and Osteoclast-Based TherapeuticsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2003Mone Zaidi Abstract Over the past decade, advances in molecular tools, stem cell differentiation, osteoclast and osteoblast signaling mechanisms, and genetically manipulated mice models have resulted in major breakthroughs in understanding osteoclast biology. This review focuses on key advances in our understanding of molecular mechanisms underlying the formation, function, and survival of osteoclasts. These include key signals mediating osteoclast differentiation, including PU.1, RANK, CSF-1/c-fms, and src, and key specializations of the osteoclast including HCl secretion driven by H+ -ATPase and the secretion of collagenolytic enzymes including cathepsin K and matrix metalloproteinases (MMPs). These pathways and highly expressed proteins provide targets for specific therapies to modify bone degradation. The main outstanding issues, basic and translational, will be considered in relation to the osteoclast as a target for antiresorptive therapies. [source] Graph-theoretical identification of dissociation pathways on free energy landscapes of biomolecular interactionJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 4 2010Ling Wang Abstract Biomolecular association and dissociation reactions take place on complicated interaction free energy landscapes that are still very hard to characterize computationally. For large enough distances, though, it often suffices to consider the six relative translational and rotational degrees of freedom of the two particles treated as rigid bodies. Here, we computed the six-dimensional free energy surface of a dimer of water-soluble alpha-helices by scanning these six degrees of freedom in about one million grid points. In each point, the relative free energy difference was computed as the sum of the polar and nonpolar solvation free energies of the helix dimer and of the intermolecular coulombic interaction energy. The Dijkstra graph algorithm was then applied to search for the lowest cost dissociation pathways based on a weighted, directed graph, where the vertices represent the grid points, the edges connect the grid points and their neighbors, and the weights are the reaction costs between adjacent pairs of grid points. As an example, the configuration of the bound state was chosen as the source node, and the eight corners of the translational cube were chosen as the destination nodes. With the strong electrostatic interaction of the two helices giving rise to a clearly funnel-shaped energy landscape, the eight lowest-energy cost pathways coming from different orientations converge into a well-defined pathway for association. We believe that the methodology presented here will prove useful for identifying low-energy association and dissociation pathways in future studies of complicated free energy landscapes for biomolecular interaction. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010 [source] New and fast statistical-thermodynamic method for computation of protein-ligand binding entropy substantially improves docking accuracyJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 11 2005A. M. Ruvinsky Abstract We present a novel method to estimate the contributions of translational and rotational entropy to protein-ligand binding affinity. The method is based on estimates of the configurational integral through the sizes of clusters obtained from multiple docking positions. Cluster sizes are defined as the intervals of variation of center of ligand mass and Euler angles in the cluster. Then we suggest a method to consider the entropy of torsional motions. We validate the suggested methods on a set of 135 PDB protein-ligand complexes by comparing the averaged root-mean square deviations (RMSD) of the top-scored ligand docked positions, accounting and not accounting for entropy contributions, relative to the experimentally determined positions. We demonstrate that the method increases docking accuracy by 10,21% when used in conjunction with the AutoDock docking program, thus reducing the percent of incorrectly docked ligands by 1.4-fold to four-fold, so that in some cases the percent of ligands correctly docked to within an RMSD of 2 Å is above 90%. We show that the suggested method to account for entropy of relative motions is identical to the method based on the Monte Carlo integration over intervals of variation of center of ligand mass and Euler angles in the cluster. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1089,1095, 2005 [source] The actuation efficiency, a measure of acceleration capability for nonredundant robotic manipulatorsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 12 2005Alan P. Bowling This article presents a performance measure, the actuation efficiency, which describes the imbalance between the end-effector accelerations achievable in different directions of nonredundant robotic manipulators. A key feature of the proposed measure is that in its development the differences in units between translational and rotational accelerations are treated in a physically meaningful manner. The measure also indicates oversized actuators, since this contributes to the imbalance in achievable accelerations. The development of this measure is based on the formulation of the dynamic capability equations. The shape of the dynamic capability hypersurface, which is defined by the dynamic capability equations, is a weak indicator of the level of imbalance in achievable end-effector accelerations. © 2005 Wiley Periodicals, Inc. [source] Handling uncertainties of robot manipulators and active vision by constraint propagationJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 9 2002Christopher C. Yang Joint errors are inevitable in robot manipulation. These uncertainties propagate to give rise to translational and orientational errors in the position and orientation of the robot end-effector. The displacement of the active vision head mounted on the robot end-effector produces distortion of the projected object on the image. Upon active visual inspection, the observed dimension of a mechanical part is given dimension by the measurement on the projected edge segment on the image. The difference between the observed dimension and the actual dimension is the displacement error in active vision. For different motion of the active vision head, the resulting displacement errors are different. Given the uncertainties of the robot manipulator's joint errors, constraint propagation can be employed to assign the motion of the active sensor in order to satisfy the tolerance of the displacement errors for inspection. In this article, we define the constraint consistency and network satisfaction in the constraint network for the problem of displacement errors in active vision. A constraint network is a network where the nodes represent variables, or constraints, and the arcs represent the relationships between the output variables and the input variables of the constraints. In the displacement errors problem, the tolerance of the displacement errors and the translational and orientational errors of robot manipulators have interval values while the sensor motion has real values. Constraint propagation is developed to propagate the tolerance of displacement errors in the hierarchical interval constraint network in order to find the feasible robot motion. © 2002 Wiley Periodicals, Inc. [source] Proteomic identification of biomarkers related to Helicobacter pylori -associated gastroduodenal disease: Challenges and opportunitiesJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2008Ming-Shiang Wu Abstract Helicobacter pylori colonize the stomach of over half the world's population. While 80,90% H. pylori -infected individuals have clinically asymptomatic gastritis, 10,15% develop peptic ulcer, and 1,2% gastric malignancies. These variable clinical outcomes have led to an interest in prognostic indicators. The current disease paradigm suggests that host genetics and bacterial virulence both play important roles in modulating the final outcome of H. pylori infection. Elucidation of the interaction between host and bacterium is essential to clarify pathogenesis and to develop new strategies for prevention and treatment. Proteomic technology is a powerful tool for simultaneously monitoring proteins and protein variation on a large scale in biological samples. It has provided an unprecedented opportunity to survey a cell's translational landscape comprehensively, and the results may allow in-depth analyses of host and pathogen interactions. Using this high-throughput platform and taking advantage of complete sequences for both the H. pylori and the human genome in available databases, we have identified several crucial proteins that have pathogenic and prognostic potential. Among them, antibodies to AhpC and GroEs of H. pylori could be utilized for identification of patients who are at high risk of disease complications after H. pylori infection. Evolving proteomic technologies, together with appropriate clinical phenotyping and genotype information should enhance understanding of disease pathogenesis and lead to more precise prediction of variable disease outcomes. It will also facilitate development of biomarkers for diagnosis, treatment, and prevention of H. pylori infection. [source] Improved dynamic susceptibility contrast (DSC)-MR perfusion estimates by motion correctionJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2007Robert K. Kosior BSc Abstract Purpose To investigate the effect of patient motion on quantitative cerebral blood flow (CBF) maps in ischemic stroke patients and to evaluate the efficacy of a motion-correction scheme. Materials and Methods Perfusion data from 25 ischemic stroke patients were selected for analysis. Two motion profiles were applied to a digital anthropomorphic brain phantom to estimate accuracy. CBF images were generated for motion-corrupted and motion-corrected data. To correct for motion, rigid-body registration was performed. The realignment parameters and mean CBF in regions of interest were recorded. Results All patient data with motion exhibited visibly reduced intervolume misalignment after motion correction. Improved flow delineation between different tissues and a more clearly defined ischemic lesion (IL) were achieved in the motion-corrected CBF. A significant difference occurred in the IL (P < 0.05) for patients with severe motion with an average difference between corrupted and corrected data of 4.8 mL/minute/100 g. The phantom data supported the patient results with better CBF accuracy after motion correction and high registration accuracy (<1 mm translational and <1° rotational error). Conclusion Motion degrades flow differentiation between adjacent tissues in CBF maps and can cause ischemic severity to be underestimated. A registration motion correction scheme improves dynamic susceptibility contrast (DSC)-MR perfusion estimates. J. Magn. Reson. Imaging 2007;26:1167,1172. © 2007 Wiley-Liss, Inc. [source] Implications of bulk motion for diffusion-weighted imaging experiments: Effects, mechanisms, and solutionsJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2001David G. Norris PhD Abstract This review article describes the effect of bulk motion on diffusion-weighted imaging experiments, and examines methods for correcting the resulting artifacts. The emphasis throughout the article is on two-dimensional imaging of the brain. The effects of translational and rotational motion on the MR signal are described, and the literature concerning pulsatile brain motion is examined. Methods for ameliorating motion effects are divided into three generic categories. The first is methods that should be intrinsically insensitive to macroscopic motion. These include motion-compensated diffusion-weighting schemes, single-shot EPI, projection reconstruction, and line scanning. Of these, only single-shot EPI and projection reconstruction methods can obtain high-quality images without compromising on sensitivity. The second category of methods is those that can be made insensitive to bulk motion. The methods examined here are FLASH and RARE. It is shown that for both sequences motion insensitivity is in general attained only at the cost of a 50% reduction in sensitivity. The final set of methods examined are those that correct for motion, primarily navigator echoes. The properties and limitations of the navigator echo approach are presented, as are those of methods which attempt to correct the acquired data by minimizing image artifacts. The review concludes with a short summary in which the current status of diffusion imaging in the presence of bulk motion is examined. J. Magn. Reson. Imaging 2001;13:486,495. © 2001 Wiley-Liss, Inc. [source] Use of the Rotation Vector in Brownian Dynamics Simulation of Transient Electro-Optical PropertiesMACROMOLECULAR THEORY AND SIMULATIONS, Issue 1 2009Tom Richard Evensen Abstract We have recently developed a new singularity-free algorithm for Brownian dynamics simulation of free rotational diffusion. The algorithm is rigorously derived from kinetic theory and makes use of the Cartesian components of the rotation vector as the generalized coordinates describing angular orientation. Here, we report on the application of this new algorithm in Brownian dynamics simulations of transient electro-optical properties. This work serves two main purposes. Firstly, it demonstrates the integrity of the new algorithm for BD-simulations of the most common transient electro-optic experiments. Secondly, it provides new insight into the performance of the new algorithm compared to algorithms that make use of the Euler angles. We study the transient electrically induced birefringence in dilute solutions of rigid particles with anisotropic polarization tensor in response to external electric field pulses. The use of both one single electric pulse and two electric pulses with opposite polarity are being analyzed. We document that the new singularity-free algorithm performs flawlessly. We find that, for these types of systems, the new singularity-free algorithm, in general, outperforms similar algorithms based on the Euler angles. In a wider perspective, the most important aspect of this work is that it serves as an important reference for future development of efficient BD-algorithms for studies of more complex systems. These systems include polymers consisting of rigid segments with single-segment translational,rotational coupling, segment,segment fluid-dynamic interactions and holonomic constraints. [source] The mechanisms of collisional activation of ions in mass spectrometryMASS SPECTROMETRY REVIEWS, Issue 4 2009Paul M. Mayer Abstract This article is a review of the mechanisms responsible for collisional activation of ions in mass spectrometers. Part I gives a general introduction to the processes occurring when a projectile ion and neutral target collide. The theoretical background to the physical phenomena of curve-crossing excitation (for electronic and vibrational excitation), impulsive collisions (for direct translational to vibrational energy transfer), and the formation of long-lived collision intermediates is presented. Part II highlights the experimental and computational investigations that have been made into collisional activation for four experimental conditions: high (>100 eV) and intermediate (1,100 eV) center-of-mass collision energies, slow heating collisions (multiple low-energy collisions) and collisions with surfaces. The emphasis in this section is on the derived post-collision internal energy distributions that have been found to be typical for projectile ions undergoing collisions in these regimes. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:608,639, 2009 [source] Silibinin inhibits the invasion of human lung cancer cells via decreased productions of urokinase-plasminogen activator and matrix metalloproteinase-2,MOLECULAR CARCINOGENESIS, Issue 3 2004Shu-Chen Chu Abstract Cancer metastasis, involving multiple processes and various cytophysiological changes, is a primary cause of cancer death and may complicate the clinical management, even lead to death. Silibinin is a flavonoid antioxidant and wildly used for its antihepatotoxic properties and recent studies have revealed pleiotropic anticancer and antiproliferative capabilities of silibinin. In this study, we first observed that silibinin exerted a dose- and time-dependent inhibitory effect on the invasion and motility, but hardly on the adhesion, of highly metastatic A549 cells in the absence of cytotoxicity. To look at the precise involvement of silibinin in cancer metastasis, A549 cells were treated with silibinin at various concentrations, up to 100 ,M, for a defined period and then subjected to gelatin zymography, casein zymography and Western blot to investigate the impacts of silibinin on metalloproteinase-2 (MMP-2), urokinase plasminogen activator (u-PA), and tissue inhibitor of metalloproteinase-2 (TIMP-2), respectively. The results showed that a silibinin treatment may decrease the expressions of MMP-2 and u-PA in a concentration- and time-dependent manner and enhance the expression of TIMP-2. Further analysis with semi-quantitative RT-PCR showed that silibinin may regulate the expressions of MMP-2 and u-PA on the transcriptional level while on the translational or post-translational level for TIMP-2. © 2004 Wiley-Liss, Inc. [source] amfR, an essential gene for aerial mycelium formation, is a member of the AdpA regulon in the A-factor regulatory cascade in Streptomyces griseusMOLECULAR MICROBIOLOGY, Issue 4 2003Haruka Yamazaki Summary In Streptomyces griseus, A-factor (2-isocapryloyl-3R -hydroxymethyl-,-butyrolactone) acts as a chemical signalling molecule that triggers morphological differentiation and secondary metabolism. A transcriptional activator, AdpA, in the A-factor regulatory cascade switches on a number of genes required for both processes, thus forming an AdpA regulon. amfR encoding a regulatory protein similar to response regulators of bacterial two-component regulatory systems and essential for aerial mycelium formation was found to be a member of the AdpA regulon. AdpA bound two sites at nucleotide positions approximately ,200 (site 1) and ,60 (site 2), with respect to the major transcriptional start point of amfR, and accelerated the transcription of amfR by assisting RNA polymerase in forming an open complex at an appropriate region including the transcriptional start point. Site 2 contributed more to the transcriptional activation of amfR by AdpA than site 1, although AdpA showed a much lower affinity to site 2 than to site 1. The amfR transcription enhanced by AdpA subsequently ceased at day 2 when aerial hyphae began to be formed in the wild-type strain, whereas in an adsA null mutant amfR was continuously transcribed even until day 3. This implied that amfR was repressed growth dependently by a gene product under the control of ,-AdsA. Transcription of the promoter upstream of amfT depended on amfR, which is consistent with the idea that AmfR serves as an activator for amfTSBA in the amf operon. The observations that the amfR gene contains a TTA codon, a potential target for bldA -mediated regulation, and a conserved Asp-54 residue, which might be phosphorylated by a sensor kinase, suggest that the amf operon is under transcriptional, translational and post-translational control systems. [source] The role of the pathologist in translational and personalized medicineMOUNT SINAI JOURNAL OF MEDICINE: A JOURNAL OF PERSONALIZED AND TRANSLATIONAL MEDICINE, Issue 1 2007Daniel P. Perl MD Abstract Over the years, pathologists have served to make morphologic diagnoses for clinicians when provided with a biopsy or surgically resected tissue specimen. Traditionally, pathologists have used a series of morphologic techniques and relied on the microscopic appearance of resected tissues to determine a pathologic diagnosis and, with respect to neoplastic lesions, provide predictions of the potential growth pattern that might be anticipated. With the introduction of the techniques of molecular biology in medicine, the role of the pathologist has changed as have the tools available for characterizing pathologic specimens. With the pathologist's unique perspective on disease processes and access to tissue specimens from the operating room, he has become a key player in the area of translational and personalized medicine and the development of new approaches to diagnosis and translational research. Mt Sinai J Med 74:22,26, 2007. © 2007 Mount Sinai School of Medicine [source] Program: Twenty Third Annual Symposium on Etiology, Pathogenesis, and Treatment of Parkinson's Disease and Other Movement DisordersMOVEMENT DISORDERS, Issue 12 2009Article first published online: 11 SEP 200 The symposium will consist of two keynote speakers and peer-reviewed platform and poster presentations designed to communicate recent research advances, including new pharmacological and non-pharmacological treatment options, in the field of Parkinson's disease, Huntington disease, ataxia, dystonia, myoclonus, Tourette's syndrome, Essential Tremor and other movement disorders thereby enhancing patient care. Professionals in neurology and related disciplines as well as practitioners, psychologists, educators, and researchers are invited to attend. The gaps in clinical practice we wish to address are the unmet needs pertaining to the translational and clinical evaluation, along with the care and treatment of patients and families affected by Parkinson's disease and other movement disorders. At the conclusion of this session, participants should be able to: 1) Identify and describe by scholarly review, oral presentation and group discussion the current research into the diagnosis, prevention and treatment of Parkinson's disease (PD) and Essential Tremor (ET) which may be relevant to current treatment or which may lead to the development of further research protocols; 2) Distinguish and assess the important advances in research and clinical treatments relating to Parkinson's disease and Essential Tremor in terms of available treatment options or new methodologies for clinical research; 3) Explain new pharmacological and non-pharmacological treatment options available for Parkinson's disease and other movement disorders in connection with their clinical practice or with regard to further clinical research methods; 4) Interpret the mechanisms (genetic, environmental, pathophysiology, neurobiology) linked to Parkinson's disease and other movement disorders when assessing Parkinson's disease or other movement disorder patients or when developing new research protocols; and 5) Employ diagnostic approaches and tools available for assessing Parkinson's disease and Essential Tremor when diagnosing new patients or when conducting clinical research. [source] Congenital central hypoventilation syndrome from past to future: Model for translational and transitional autonomic medicine,PEDIATRIC PULMONOLOGY, Issue 6 2009Debra E. Weese-Mayer Abstract The modern story of CCHS began in 1970 with the first description by Mellins et al., came most visibly to the public eye with the ATS Statement in 1999, and continues with increasingly fast paced advances in genetics. Affected individuals have diffuse autonomic nervous system dysregulation (ANSD). The paired-like homeobox gene PHOX2B is the disease-defining gene for CCHS; a mutation in the PHOX2B gene is requisite to the diagnosis of CCHS. Approximately 90% of individuals with the CCHS phenotype will be heterozygous for a polyalanine repeat expansion mutation (PARM); the normal allele will have 20 alanines and the affected allele will have 24,33 alanines (genotypes 20/24,20/33). The remaining ,10% of individuals with CCHS will have a non-PARM (NPARM), in the PHOX2B gene; these will be missense, nonsense, or frameshift. CCHS and PHOX2B are inherited in an autosomal dominant manner with a stable mutation. Approximately 8% of parents of a CCHS proband will be mosaic for the PHOX2B mutation. A growing number of cases of CCHS are identified after the newborn period, with presentation from infancy into adulthood. An improved understanding of the molecular basis of the PHOX2B mutations and of the PHOX2B genotype/CCHS phenotype relationship will allow physicians to anticipate the clinical phenotype for each affected individual. To best convey the remarkable history of CCHS, and to describe the value of recognizing CCHS as a model for translational and transitional autonomic medicine, we present this review article in the format of a chronological story, from 1970 to the present day. Pediatr Pulmonol. 2009; 44:521,535. © 2009 Wiley-Liss, Inc. [source] Sickle Cell Disease Summit: From clinical and research disparity to action,,AMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2009Kathryn Hassell The American Society of Pediatric Hematology/Oncology Sickle Cell Summit brought together a broad range of constituencies to identify a unified approach to healthcare and research disparities for sickle cell disease. Recommendations included the following: (1) speak with a unified voice representing all constituencies; (2) optimize access to care from knowledgeable health care providers and create a medical home for all individuals with the disease; (3) utilize population-based surveillance to measure outcomes; (4) develop overall approaches to basic, translational, clinical, and health services research; (5) enhance the community role in advocacy, education, service, and fundraising. Taskforces were identified to effect implementation. Am. J. Hematol., 2009. © 2008 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||