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Generalized
Terms modified by Generalized Selected AbstractsMethods for the analysis of trends in streamflow response due to changes in catchment conditionENVIRONMETRICS, Issue 7 2001R. A. Letcher Abstract Two algorithms for analysing changes in streamflow response due to changes in land use and farm dam development, based on the Estimated Generalized Least Squares (EGLS) and the Generalized Additive Model (GAM) methods, were compared on three catchments in the Macquarie River Basin in NSW, Australia. In order to account for the influence of climatic conditions on streamflow response, the IHACRES conceptual rainfall-runoff model was calibrated on a daily time step over two-year periods then simulated over the entire period of concurrent rainfall, streamflow and temperature data. Residuals or differences between observed and simulated flows were calculated. The EGLS method was applied to a smoothing of the residual (daily) time series. Such residuals represent the difference between the simulated streamflow response to a fixed catchment condition (in the calibration period) and that due to the actual varying conditions throughout the record period. The GAM method was applied to quarterly aggregated residuals. The methods provided similar qualitative results for trends in residual streamflow response in each catchment for models with a good fitting performance on the calibration period in terms of a number of statistics, i.e. the coefficient of efficiency R2, bias and average relative parameter error (ARPE). It was found that the fit of the IHACRES model to the calibration period is critically important in determining trend values and significance. Models with well identified parameters and less correlation between rainfall and model residuals are likely to give the best results for trend analysis. Copyright © 2001 John Wiley & Sons, Ltd. [source] Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005,2009EPILEPSIA, Issue 4 2010Anne T. Berg Summary The International League Against Epilepsy (ILAE) Commission on Classification and Terminology has revised concepts, terminology, and approaches for classifying seizures and forms of epilepsy. Generalized and focal are redefined for seizures as occurring in and rapidly engaging bilaterally distributed networks (generalized) and within networks limited to one hemisphere and either discretely localized or more widely distributed (focal). Classification of generalized seizures is simplified. No natural classification for focal seizures exists; focal seizures should be described according to their manifestations (e.g., dyscognitive, focal motor). The concepts of generalized and focal do not apply to electroclinical syndromes. Genetic, structural,metabolic, and unknown represent modified concepts to replace idiopathic, symptomatic, and cryptogenic. Not all epilepsies are recognized as electroclinical syndromes. Organization of forms of epilepsy is first by specificity: electroclinical syndromes, nonsyndromic epilepsies with structural,metabolic causes, and epilepsies of unknown cause. Further organization within these divisions can be accomplished in a flexible manner depending on purpose. Natural classes (e.g., specific underlying cause, age at onset, associated seizure type), or pragmatic groupings (e.g., epileptic encephalopathies, self-limited electroclinical syndromes) may serve as the basis for organizing knowledge about recognized forms of epilepsy and facilitate identification of new forms. [source] From basic research to the bedside: efficacy of topical treatment with pseudocatalase PC-KUS in 71 children with vitiligoINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 7 2008Karin U. Schallreuter MD Background The epidermal accumulation of hydrogen peroxide (H2O2) has been documented in vitiligo. Aim To assess the effect on disease cessation and repigmentation of the reduction/removal of H2O2 using low-dose, narrow-band, ultraviolet-B (UV-B)-activated pseudocatalase PC-KUS in 71 children with vitiligo. Methods This uncontrolled and retrospective study included 45 girls and 26 boys (mean age, 10.3 years) who applied topical PC-KUS twice daily to the entire body surface without narrow-band UV-B dose increments. The affected body areas were documented by special photography at the first visit and after 8,12 months. The response was evaluated by two independent physicians as > 75% vs. < 75% total repigmentation of the face/neck, trunk, extremities, and hands/feet. Generalized (n = 61) and segmental (n = 10) vitiligo were evaluated as different entities. The effect of total-body, low-dose, narrow-band UV-B (0.15 mJ/cm2) monotherapy once daily without any increments and without application of PC-KUS was tested over 6 months in 10 children with vitiligo vulgaris (mean age, 8.4 years). Results One hundred per cent cessation was observed in 70 of the 71 children. More than 75% repigmentation was achieved in 66 of 71 patients on the face/neck, 48 of 61 on the trunk, and 40 of 55 on the extremities; however, repigmentation on the hands/feet was disappointing (five of 53). The response was independent of skin color, age of onset, duration of disease, other demographic features, and previous treatments. The follow-up after narrow-band UV-B monotherapy showed no significant repigmentation in all areas. Seven of 10 patients showed progression of their vitiligo. Conclusion A reduction in epidermal H2O2 using low-dose, narrow-band UV-B-activated pseudocatalase PC-KUS is an effective treatment for childhood vitiligo which can be safely performed at home. [source] Free energy and structure of polyproline peptides: An ab initio and classical molecular dynamics investigationINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 15 2010Mahmoud Moradi Abstract Depending on their environment, polyproline peptides form chiral helices that may be either left- (PPII) or right-handed (PPI). Here, we have characterized both the structure and free energy landscapes of Ace-(Pro)n -Nme (n an integer less than 13) peptides, in vacuo and in implicit water environments. Both ab initio and classical molecular dynamics methods were used. In terms of the latter, we used a recently developed Adaptively Biased Molecular Dynamics (ABMD) method in conjunction with three different force fields (ff99, ff99SB, ff03) and two different Generalized Born models for the implicit solvent environment. Specifically, the ABMD method provides for an accurate description of the free energy landscapes in terms of a set of collective variables, which were carefully chosen as to reflect the "slow modes" of the polyproline peptides. These are primarily based on the cis - trans isomerization associated with the prolyl bonds. In agreement with recent experimental results, the peptides form not only the pure PPII or PPI structures but also a large number of stable conformers having more or less similar free energies, whose distributions we have characterized. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [source] Accurate prediction of protonation state as a prerequisite for reliable MM-PB(GB)SA binding free energy calculations of HIV-1 protease inhibitorsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 5 2008Kitiyaporn Wittayanarakul Abstract Binding free energies were calculated for the inhibitors lopinavir, ritonavir, saquinavir, indinavir, amprenavir, and nelfinavir bound to HIV-1 protease. An MMPB/SA-type analysis was applied to conformational samples from 3 ns explicit solvent molecular dynamics simulations of the enzyme-inhibitor complexes. Binding affinities and the sampled conformations of the inhibitor and enzyme were compared between different HIV-1 protease protonation states to find the most likely protonation state of the enzyme in the complex with each of the inhibitors. The resulting set of protonation states leads to good agreement between calculated and experimental binding affinities. Results from the MMPB/SA analysis are compared with an explicit/implicit hybrid scheme and with MMGB/SA methods. It is found that the inclusion of explicit water molecules may offer a slight advantage in reproducing absolute binding free energies while the use of the Generalized Born approximation significantly affects the accuracy of the calculated binding affinities. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Influence of temperature, friction, and random forces on folding of the B-domain of staphylococcal protein A: All-atom molecular dynamics in implicit solventJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 6 2007Anna Jagielska Abstract The influences of temperature, friction, and random forces on the folding of protein A have been analyzed. A series of all-atom molecular dynamics folding simulations with the Amber ff99 potential and Generalized Born solvation, starting from the fully extended chain, were carried out for temperatures from 300 to 500 K, using (a) the Berendsen thermostat (with no explicit friction or random forces) and (b) Langevin dynamics (with friction and stochastic forces explicitly present in the system). The simulation temperature influences the relative time scale of the major events on the folding pathways of protein A. At lower temperatures, helix 2 folds significantly later than helices 1 and 3. However, with increasing temperature, the folding time of helix 2 approaches the folding times of helices 1 and 3. At lower temperatures, the complete formation of secondary and tertiary structure is significantly separated in time whereas, at higher temperatures, they occur simultaneously. These results suggest that some earlier experimental and theoretical observations of folding events, e.g., the order of helix formation, could depend on the temperature used in those studies. Therefore, the differences in temperature used could be one of the reasons for the discrepancies among published experimental and computational studies of the folding of protein A. Friction and random forces do not change the folding pathway that was observed in the simulations with the Berendsen thermostat, but their explicit presence in the system extends the folding time of protein A. © 2007 Wiley Periodicals, Inc. J Comput Chem 2007 [source] The parameterization and validation of generalized born models using the pairwise descreening approximationJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 14 2004Julien Michel Abstract Generalized Born Surface Area (GBSA) models for water using the Pairwise Descreening Approximation (PDA) have been parameterized by two different methods. The first method, similar to that used in previously reported parameterizations, optimizes all parameters against the experimental free energies of hydration of organic molecules. The second method optimizes the PDA parameters to compensate only for systematic errors of the PDA. The best models are compared to Poisson,Boltzmann calculations and applied to the computation of potentials of mean force (PMFs) for the association of various molecules. PMFs present a more rigorous test of the ability of a solvation model to correctly reproduce the screening of intermolecular interactions by the solvent, than its accuracy at predicting free energies of hydration of small molecules. Models derived with the first method are sometimes shown to fail to compute accurate potentials of mean force because of large errors in the computation of Born radii, while no such difficulties are observed with the second method. Furthermore, accurate computation of the Born radii appears to be more important than good agreement with experimental free energies of solvation. We discuss the source of errors in the potentials of mean force and suggest means to reduce them. Our findings suggest that Generalized Born models that use the Pairwise Descreening Approximation and that are derived solely by unconstrained optimization of parameters against free energies of hydration should be applied to the modeling of intermolecular interactions with caution. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1760,1770, 2004 [source] Converging free energy estimates: MM-PB(GB)SA studies on the protein,protein complex Ras,RafJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 2 2004Holger Gohlke Abstract Estimating protein,protein interaction energies is a very challenging task for current simulation protocols. Here, absolute binding free energies are reported for the complex H-Ras/C-Raf1 using the MM-PB(GB)SA approach, testing the internal consistency and model dependence of the results. Averaging gas-phase energies (MM), solvation free energies as determined by Generalized Born models (GB/SA), and entropic contributions calculated by normal mode analysis for snapshots obtained from 10 ns explicit-solvent molecular dynamics in general results in an overestimation of the binding affinity when a solvent-accessible surface area-dependent model is used to estimate the nonpolar solvation contribution. Applying the sum of a cavity solvation free energy and explicitly modeled solute,solvent van der Waals interaction energies instead provides less negative estimates for the nonpolar solvation contribution. When the polar contribution to the solvation free energy is determined by solving the Poisson,Boltzmann equation (PB) instead, the calculated binding affinity strongly depends on the atomic radii set chosen. For three GB models investigated, different absolute deviations from PB energies were found for the unbound proteins and the complex. As an alternative to normal-mode calculations, quasiharmonic analyses have been performed to estimate entropic contributions due to changes of solute flexibility upon binding. However, such entropy estimates do not converge after 10 ns of simulation time, indicating that sampling issues may limit the applicability of this approach. Finally, binding free energies estimated from snapshots of the unbound proteins extracted from the complex trajectory result in an underestimate of binding affinity. This points to the need to exercise caution in applying the computationally cheaper "one-trajectory-alternative" to systems where there may be significant changes in flexibility and structure due to binding. The best estimate for the binding free energy of Ras,Raf obtained in this study of ,8.3 kcal mol,1 is in good agreement with the experimental result of ,9.6 kcal mol,1, however, further probing the transferability of the applied protocol that led to this result is necessary. © 2003 Wiley Periodicals, Inc. J Comput Chem 2: 238,250, 2003 [source] Solvent models for protein,ligand binding: Comparison of implicit solvent poisson and surface generalized born models with explicit solvent simulationsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 6 2001Linda Yu Zhang Abstract Solvent effects play a crucial role in mediating the interactions between proteins and their ligands. Implicit solvent models offer some advantages for modeling these interactions, but they have not been parameterized on such complex problems, and therefore, it is not clear how reliable they are. We have studied the binding of an octapeptide ligand to the murine MHC class I protein using both explicit solvent and implicit solvent models. The solvation free energy calculations are more than 103 faster using the Surface Generalized Born implicit solvent model compared to FEP simulations with explicit solvent. For some of the electrostatic calculations needed to estimate the binding free energy, there is near quantitative agreement between the explicit and implicit solvent model results; overall, the qualitative trends in the binding predicted by the explicit solvent FEP simulations are reproduced by the implicit solvent model. With an appropriate choice of reference system based on the binding of the discharged ligand, electrostatic interactions are found to enhance the binding affinity because the favorable Coulomb interaction energy between the ligand and protein more than compensates for the unfavorable free energy cost of partially desolvating the ligand upon binding. Some of the effects of protein flexibility and thermal motions on charging the peptide in the solvated complex are also considered. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 591,607, 2001 [source] Generalized least squares with misspecified serial correlation structuresJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 3 2001Sergio G. Koreisha Summary. The regression literature contains hundreds of studies on serially correlated disturbances. Most of these studies assume that the structure of the error covariance matrix , is known or can be estimated consistently from data. Surprisingly, few studies investigate the properties of estimated generalized least squares (GLS) procedures when the structure of , is incorrectly identified and the parameters are inefficiently estimated. We compare the finite sample efficiencies of ordinary least squares (OLS), GLS and incorrect GLS (IGLS) estimators. We also prove new theorems establishing theoretical efficiency bounds for IGLS relative to GLS and OLS. Results from an exhaustive simulation study are used to evaluate the finite sample performance and to demonstrate the robustness of IGLS estimates vis-à-vis OLS and GLS estimates constructed for models with known and estimated (but correctly identified) ,. Some of our conclusions for finite samples differ from established asymptotic results. [source] Verallgemeinerungsfähige Merkmale und Besonderheiten des SprühkompaktierensMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 1 2003K. Bauckhage Sprayforming; Modelling Microstructure; Geometry Abstract Dadurch, daß beim Sprühkompaktieren die schnelle Erstarrung und Abkühlung des Materials das Ausmaß von Entmischungen eindämmen, können Makroseigerungen unterbunden und Anreicherungen an den Korngrenzen deutlich verringert werden. Ferner wird das Risiko der Lunker- und Warmrißbildung durch den Impuls des Massetransportes während des Kompaktiervorganges stark reduziert. Dies bedeutet, daß solche Materialien, die bspw. beim Gießen zu starker Seigerung neigen und besonders anfällig für die Lunkerbildung und/oder Warmrißbildung sind sowie bei Umformverfahren zur Zeilenbildung von Carbiden, Nitriden oder Sulfiden neigen, mit Hilfe des Sprühkompaktierens im Freiformverfahren mit großen Abmaßen chemisch homogen und fehlerfrei herstellbar werden. Ein besonderes Merkmal sprühkompaktierter Deposits ist ihr feines Gefüge und ihre vergleichsweise hohe Duktilität. Die Besonderheiten des neuartigen Urformverfahrens werden anhand von Beispielen erläutert. Characteristic Features and Specific Qualifications of the Sprayforming Process to be Generalized The solidification and cooling process of spray formed materials predominates the extent of any segregation and separation process, which is conducive to avoid macro-segregation and to diminish concentration of alloying components at the grain boundaries. The risk of coarse porosity or of hot cracking is reduced significantly by the momentum of the mass flow during spray deposition. This means that those materials which e.g. during the casting process tend to establish strong segregation effects and cavities and/or hot cracks as well as those which tend to create filaments of carbides, nitrides or sulphides during rolling can be generated by the spray forming process in large dimensions with chemical homogeneity and without any of those defects. A characteristic feature of spray formed materials is the fine equiaxed grain structure and the high ductility. Specific features of this new free forming process will be discussed. [source] Generalized and neurotransmitter-selective noradrenergic denervation in Parkinson's disease with orthostatic hypotension,MOVEMENT DISORDERS, Issue 12 2008Yehonatan Sharabi MD Abstract Patients with Parkinson's disease (PD) often have manifestations of autonomic failure. About 40% have neurogenic orthostatic hypotension (NOH), and among PD+NOH patients virtually all have evidence of cardiac sympathetic denervation; however, whether PD+NOH entails extra-cardiac noradrenergic denervation has been less clear. Microdialysate concentrations of the main neuronal metabolite of norepinephrine (NE) and dihydroxyphenylglycol (DHPG) were measured in skeletal muscle, and plasma concentrations of NE and DHPG were measured in response to i.v. tyramine, yohimbine, and isoproterenol, in patients with PD+NOH, patients with pure autonomic failure (PAF), which is characterized by generalized catecholaminergic denervation, and control subjects. Microdialysate DHPG concentrations were similarly low in PD+NOH and PAF compared to control subjects (163 ± 25, 153 ± 27, and 304 ± 27 pg/mL, P < 0.01 each vs. control). The two groups also had similarly small plasma DHPG responses to tyramine (71 ± 58 and 82 ± 105 vs. 313 ± 94 pg/mL; P < 0.01 each vs. control) and NE responses to yohimbine (223 ± 37 and 61 ± 15 vs. 672 ± 130 pg/mL, P < 0.01 each vs. control), and virtually absent NE responses to isoproterenol (20 ± 34 and 14 ± 15 vs. 336 ± 78 pg/mL, P < 0.01 each vs. control). Patients with PD+NOH had normal bradycardia responses to edrophonium and normal epinephrine responses to glucagon. The results support the concept of generalized noradrenergic denervation in PD+NOH, with similar severity to that seen in PAF. In contrast, the parasympathetic cholinergic and adrenomedullary hormonal components of the autonomic nervous system seem intact in PD+NOH. © 2008 Movement Disorder Society [source] Non-linear dynamic contact of thin-walled structuresPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2008Thomas Cichosz In many areas of mechanical engineering contact problems of thin,walled structures play a crucial role. Car crash tests and incremental sheet metal forming can be named as examples. But also in civil engineering, for instance when determining the moment,rotation characteristics of a bolted beam,column joint, contact occurs. Effective simulation of these and other contact problems, especially in three,dimensional non,linear implicit structural mechanic is still a challenging task. Modelling of those problems needs a robust method, which takes the thin,walled character and dynamic effects into account. We use a segment,to,segment approach for discretization of the contact and introduce Lagrange Multipliers, which physically represent the contact pressure. The geometric impenetrability condition is formulated in a weak, integral sense. Choosing dual shape functions for the interpolation of the Lagrange Multipliers, we obtain decoupled nodal constraint conditions. Combining this with an active set strategy, an elimination of the Lagrange multipliers is easily possible, so that the size of the resulting system of equations remains constant. Discretization in time is done with the implicit Generalized-, Method and the Generalized Energy,Momentum Method. Using the "Velocity,Update" Method, the total energy is conserved for frictionless contact. Various examples show the performance of the presented strategies. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Dynamic adjustment cost models with forward-looking behaviourTHE ECONOMETRICS JOURNAL, Issue 1 2006Luca Fanelli Summary, In this paper we propose a new approach for dynamic decision problems where forward-looking agents choose a set of non-stationary variables subject to quadratic adjustment costs. It is assumed that expectations are computed by a cointegrated Vector Equilibrium Correction Model (VEqCM). The role of feedbacks from the decision to the explanatory variables on solution properties and modelling approach is discussed. We show that once the system of interrelated Euler equations stemming from the agent's optimization problem is embedded within the VEqCM, a switching algorithm based on Generalized Least Squares can be used to estimate and test the model. A labour demand model for two Danish manufacturing industries is investigated empirically. [source] Study on the inhibitory mechanism and binding mode of the hydroxycoumarin compound NSC158393 to HIV-1 integrase by molecular modelingBIOPOLYMERS, Issue 9 2009Ming Liu Abstract Human immunodeficiency virus type 1 integrase (IN) is an essential enzyme in the life cycle of this virus and also an important target for the study of anti-HIV drugs. In this work, the binding modes of the wild type IN core domain and the two mutants, that is, W132G and C130S, with the 4-hydroxycoumarin compound NSC158393 were evaluated by using the "relaxed complex" molecular docking approach combined with molecular dynamics (MD) simulations. Based on the monomer MD simulations, both of the two substitutions affect not only the stability of the 128,136 peptides, but also the flexibility of the functional 140s loop. In principle, NSC158393 binds the 128,136 peptides of IN; however, the specific binding modes for the three systems are various. According to the binding mode of NSC158393 with WT, NSC158393 can effectively interfere with the stability of the IN dimer by causing a steric hindrance around the monomer interface. Additionally, through the comparative analysis of the MD trajectories of the wild type IN and the IN-NSC158393 complex, we found that NSC15893 may also exert its inhibitory function by diminishing the mobility of the function loop of IN. Three key binding residues, that is, W131, K136, and G134, were discovered by energy decomposition calculated with the Molecular Mechanics Generalized Born Surface Area method. Characterized by the largest binding affinity, W131 is likely to be indispensable for the ligand binding. All the above results are consistent with experiment data, providing us some helpful information for understanding the mechanism of the coumarin-based inhibitors. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 700,709, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] ADAPTATION KNOWLEDGE ACQUISITION: A CASE STUDY FOR CASE-BASED DECISION SUPPORT IN ONCOLOGYCOMPUTATIONAL INTELLIGENCE, Issue 3-4 2006Mathieu D'Aquin Kasimir is a case-based decision support system in the domain of breast cancer treatment. For this system, a problem is given by the description of a patient and a solution is a set of therapeutic decisions. Given a target problem, Kasimir provides several suggestions of solutions, based on several justified adaptations of source cases. Such adaptation processes are based on adaptation knowledge. The acquisition of this kind of knowledge from experts is presented in this paper. It is shown how the decomposition of adaptation processes by introduction of intermediate problems can highlight simple and generalizable adaptation steps. Moreover, some adaptation knowledge units that are generalized from those acquired for Kasimir are presented. This knowledge can be instantiated in other case-based decision support systems, in particular in medicine. [source] Improving realism of a surgery simulator: linear anisotropic elasticity, complex interactions and force extrapolationCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3 2002Guillaume Picinbono Abstract In this article, we describe the latest developments of the minimally invasive hepatic surgery simulator prototype developed at INRIA. The goal of this simulator is to provide a realistic training test bed to perform laparoscopic procedures. Therefore, its main functionality is to simulate the action of virtual laparoscopic surgical instruments for deforming and cutting tridimensional anatomical models. Throughout this paper, we present the general features of this simulator including the implementation of several biomechanical models and the integration of two force-feedback devices in the simulation platform. More precisely, we describe three new important developments that improve the overall realism of our simulator. First, we have developed biomechanical models, based on linear elasticity and finite element theory, that include the notion of anisotropic deformation. Indeed, we have generalized the linear elastic behaviour of anatomical models to ,transversally isotropic' materials, i.e. materials having a different behaviour in a given direction. We have also added to the volumetric model an external elastic membrane representing the ,liver capsule', a rather stiff skin surrounding the liver, which creates a kind of ,surface anisotropy'. Second, we have developed new contact models between surgical instruments and soft tissue models. For instance, after detecting a contact with an instrument, we define specific boundary constraints on deformable models to represent various forms of interactions with a surgical tool, such as sliding, gripping, cutting or burning. In addition, we compute the reaction forces that should be felt by the user manipulating the force-feedback devices. The last improvement is related to the problem of haptic rendering. Currently, we are able to achieve a simulation frequency of 25,Hz (visual real time) with anatomical models of complex geometry and behaviour. But to achieve a good haptic feedback requires a frequency update of applied forces typically above 300,Hz (haptic real time). Thus, we propose a force extrapolation algorithm in order to reach haptic real time. Copyright © 2002 John Wiley & Sons, Ltd. [source] Adaptive Zooming in Web CartographyCOMPUTER GRAPHICS FORUM, Issue 4 2002Alesandro Cecconi Abstract Beyond any doubt much of the current web mapping and web GIS applications lack cartographic quality. Thereasons aren't only the technical limitations related to Internet delivery, but also the neglect of one of the maincartographic principles of digital mapping, namely adaptive zooming. Adaptive zooming describes the adjustmentof a map, its contents and the symbolization to target scale in consequence of a zooming operation. The approachdescribed in this paper proposes the combination of two commonly known concepts: on the one hand levelsof detail (LoD) for those object classes, that require high computational cost for the automated generalizationprocess (e.g. buildings, road network); on the other hand an on-the-fly generalization for those object classeswhich can be generalized by less complex methods and algorithms (e.g. rivers, lakes). Realizing such interactiveand dynamic concept for web mapping requires the use of vector based visualization tools. The data format bestmeeting the criteria is the W3C standard Scalable Vector Graphics (SVG). Thus, it has been used to implementthe presented ideas in a prototype application for topographic web mapping based on the landscape modelVECTOR25 of the Swiss Federal Office of Topography. [source] Real-Time OD Estimation Using Automatic Vehicle Identification and Traffic Count DataCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2002Michael P. Dixon A key input to many advanced traffic management operations strategies are origin,destination (OD) matricies. In order to examine the possibility of estimating OD matricies in real-time, two constrained OD estimators, based on generalized least squares and Kalman filtering, were developed and tested. A one-at-a-time processing method was introduced to provide an efficient organized framework for incorporating observations from multiple data sources in real-time. The estimators were tested under different conditions based on the type of prior OD information available, the type of assignment available, and the type of link volume model used. The performance of the Kalman filter estimators also was compared to that of the generalized least squares estimator to provide insight regarding their performance characteristics relative to one another for given scenarios. Automatic vehicle identification (AVI) tag counts were used so that observed and estimated OD parameters could be compared. While the approach was motivated using AVI data, the methodology can be generalized to any situation where traffic counts are available and origin volumes can be estimated reliably. The primary means by which AVI data was utilized was through the incorporation of prior observed OD information as measurements, the inclusion of a deterministic link volume component that makes use of OD data extracted from the latest time interval from which all trips have been completed, and through the use of link choice proportions estimated based on link travel time data. It was found that utilizing prior observed OD data along with link counts improves estimator accuracy relative to OD estimation based exclusively on link counts. [source] Java multithreading-based parallel approximate arrow-type inversesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 10 2008George A. Gravvanis Abstract A new parallel shared memory Java multithreaded design and implementation of the explicit approximate inverse preconditioning, for efficiently solving arrow-type linear systems on symmetric multiprocessor systems (SMPs), is presented. A new parallel algorithm for computing a class of optimized approximate arrow-type inverse matrix is introduced. The performance on an SMP, using Java multithreading, is investigated by solving arrow-type linear systems and numerical results are given. The parallel performance of the construction of the optimized approximate inverse and the explicit preconditioned generalized conjugate gradient square scheme, using a dynamic workload scheduling, is also presented. Copyright © 2007 John Wiley & Sons, Ltd. [source] Pemphigus Foliaceus Masquerading as Postoperative Wound Infection: Report of a Case and Review of the Koebner and Related Phenomenon following Surgical ProceduresDERMATOLOGIC SURGERY, Issue 2 2005Adam M. Rotunda MD Background The Koebner phenomenon, also known as the isomorphic response, is the development of preexisting skin disease following trauma to uninvolved skin. Various cutaneous disorders have been described to arise at surgical wounds and scars. Moreover, dermatologic procedures, such as cold-steel and laser surgery, can evoke koebnerization. Objective To describe a case of pemphigus foliaceus arising in postoperative wounds and to present a review of dermatologic disorders triggered by surgical procedures. Methods We report a case of pemphigus foliaceus initially presenting at sites of Mohs' micrographic surgery, shave biopsy, and cryotherapy and, subsequently, at a nonsurgical site. We reviewed the English literature in MEDLINE from November 1955 to April 2004 for reports of Koebner and related phenomenon following surgical procedures. Results To our knowledge, this is the first reported case of pemphigus foliaceus erupting at surgical and cryotherapy wounds. The clinical appearance can mimic wound infection. In addition to inducing preexisting disease, cutaneous procedures can also trigger the onset of new disease, which can either be limited only to the surgical site or subsequently become generalized. Conclusion Postoperative Koebner or related responses should be included in the differential diagnosis of poorly healing surgical wounds. Skin biopsies for histopathology and immunologic studies may be necessary for definitive diagnosis and optimal management. ADAM M. ROTUNDA, MD, ANAND R. BHUPATHY, DO, ROBERT DYE, MD, AND TERESA T. SORIANO, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source] THE THERAPEUTIC EXCEPTION: ABORTION, STERILIZATION AND MEDICAL NECESSITY IN COSTA RICADEVELOPING WORLD BIOETHICS, Issue 2 2007MARÍA CARRANZA ABSTRACT Based on the case of Rosa, a nine-year-old girl who was denied a therapeutic abortion, this article analyzes the role played by the social in medical practice. For that purpose, it compares the different application of two similar pieces of legislation in Costa Rica, where both the practice of abortion and sterilization are restricted to the protection of health and life by the Penal Code. As a concept subject to interpretation, a broad conception of medical necessity could enable an ample use of the therapeutic exception and a liberal use of both surgeries. The practice of therapeutic sterilization has been generalized in Costa Rica and has become the legitimate way to distribute contraceptive sterilization. In contrast, therapeutic abortion is very rarely practiced. The analysis carried out proposes that it is the difference in social acceptance of abortion and sterilization that explains the different use that doctors, as gatekeepers of social morality, make of medical necessity. [source] Baseline cognition, behavior, and motor skills in children with new-onset, idiopathic epilepsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2010VIKRAM V BHISE Aim, Epilepsy is associated with difficulties in cognition and behavior in children. These problems have been attributed to genetics, ongoing seizures, psychosocial issues, underlying abnormality of the brain, and/or antiepileptic drugs. In a previous study, we found baseline cognitive differences between children with partial versus generalized and convulsive versus non-convulsive seizures. Measures in that study focused primarily on IQ scores. In the present study, we assessed baseline function with respect to new learning, attention, and memory, thus providing a more comprehensive profile than our previous study. Method, We examined 57 children (42 females, 15 males), aged 6 to 17 years (mean 10y 1mo, SD 2y 9mo), with new-onset, idiopathic epilepsy, using tests of cognitive function reflective of new learning, memory, and attention. Seizures were classified as generalized convulsive (n=5), generalized non-convulsive (n=18), or focal (n=34). Focal seizures were divided into unilateral versus bilateral independent foci, and presence versus absence of secondary generalization. Results, Attention was a particular area of weakness across all groups. The Vocabulary score of an intelligence screen was higher for the focal seizure groups (p=0.012), primarily because of a difference between the unilateral focal and the primary generalized groups (p<0.047). Children with generalized, non-convulsive seizures performed significantly worse than the focal group on a measure of short-term auditory memory (p=0.019). All groups performed poorly on a test of visual,motor speed. Interpretation, These findings suggest intrinsic abnormalities in children with new-onset, idiopathic epilepsy at baseline. [source] Neuropsychological profile of children with subcortical band heterotopiaDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 11 2009MEGAN SPENCER-SMITH BPSYCSC PHD Aim, Subcortical band heterotopia (SBH) or ,double cortex' is a malformation of cortical development resulting from impaired neuronal migration. So far, research has focused on the neurological, neuroimaging, and genetic correlates of SBH. More recently, clinical reports and small sample studies have documented neuropsychological dysfunction in patients with this malformation. This study aimed to characterize further the phenotype of patients with SBH by describing the neuropsychological profiles of children. Method, Seven children (six females) aged 4 to 15 years were assessed for cognitive functioning (intellectual ability, processing speed, attention, working memory) and academic achievement (reading, spelling, arithmetic). Parents completed questionnaires examining their child's social skills and problem behaviours. Magnetic resonance images (MRI) conducted for routine clinical follow-up were coded by a paediatric neurologist. Genetic and seizure history were obtained from medical records. Results, There was variation in the neurological, neuroimaging, and genetic presentation of children in the sample. Impairments were observed in all areas of neuropsychological functioning examined. Intellectual ability was generally within the ,extremely low' range (full-scale IQ 44,74; performance IQ 45,72; verbal IQ 57,80). Generalized impairments in cognitive skills were typical, with severe impairments (scores greater than 2SD below the test mean) reported in processing speed, working memory, and arithmetic. Impairments in academic, social, and behavioural functioning were less generalized. No clear relationship between neuroimaging and neuropsychological impairments was found. Interpretation, Children with SBH demonstrate cognitive, academic, social, and behavioural problems, with the greatest difficulties in processing speed and complex cognitive skills. [source] Psychosocial problems and seizure-related factors in children with epilepsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 3 2006B Høie In this study we describe psychosocial functions and seizurerelated factors in a population-based sample of children with epilepsy. Psychosocial problems (Achenbach scales), cognitive function, and socioeconomic status were studied in 117 children with epilepsy aged between 6 and 13 years (mean age 11y [SD 2y 1mo] and 10y 8mo [SD 2y]; 71 males, 46 females) and in randomly selected controls matched with 117 children for sex and age (mean age 11y 2mo [SD 2y 1mo] and 10y 5mo [SD 2y 4mo]; 69 males, 48 females). The children had partial (n=67), generalized (n=43), or undetermined (n=7) epilepsy syndromes, and partial (n=68), generalized (n=47), or other (n=2) main seizure types. Psychosocial problems were more common among children with epilepsy than controls (odds ratio 5,9) and significantly related to epilepsy syndrome, main seizure type, age at onset, and seizure frequency. Mothers and teachers reported males with epilepsy as having more problems than females. Females self-reported psychosocial problems, males did not. Psychosocial problems were common in childhood epilepsy. Females appreciated the problems more realistically than males. Psychosocial problems should be considered an integral part of epilepsy management. [source] Psychiatric services for people with severe mental illness across western Europe: what can be generalized from current knowledge about differences in provision, costs and outcomes of mental health care?ACTA PSYCHIATRICA SCANDINAVICA, Issue 2006T. Becker Objective:, To report recent findings regarding differences in the provision, cost and outcomes of mental health care in Europe, and to examine to what extent these studies can provide a basis for improvement of mental health services and use of findings across countries. Method:, Findings from a number of studies describing mental health care in different European countries and comparing provision of care across countries are reported. Results:, The development of systems of mental health care in western Europe is characterized by a common trend towards deinstitutionalization, less in-patient treatment and improvement of community services. Variability between national mental healthcare systems is still substantial. At the individual patient level the variability of psychiatric service systems results in different patterns of service use and service costs. However, these differences are not reflected in outcome differences in a coherent way. Conclusion:, It is conceivable that the principal targets of mental healthcare reform can be achieved along several pathways taking into account economic, political and sociocultural variation between countries. Differences between mental healthcare systems appear to affect service provision and costs. However, the impact of such differences on patient outcomes may be less marked. The empirical evidence is limited and further studies are required. [source] Comparison of the effects of HGF, BDNF, CT-1, CNTF, and the branchial arches on the growth of embryonic cranial motor neuronsDEVELOPMENTAL NEUROBIOLOGY, Issue 2 2002Arifa Naeem Abstract In the developing embryo, axon growth and guidance depend on cues that include diffusible molecules. We have shown previously that the branchial arches and hepatocyte growth factor (HGF) are growth-promoting and chemoattractant for young embryonic cranial motor axons. HGF is produced in the branchial arches of the embryo, but a number of lines of evidence suggest that HGF is unlikely to be the only factor involved in the growth and guidance of these axons. Here we investigate whether other neurotrophic factors could be involved in the growth of young cranial motor neurons in explant cultures. We find that brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF) and cardiotrophin-1 (CT-1) all promote the outgrowth of embryonic cranial motor neurons, while glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3) fail to affect outgrowth. We next examined whether HGF and the branchial arches had similar effects on motor neuron subpopulations at different axial levels. Our results show that HGF acts as a generalized rather than a specific neurotrophic factor and guidance cue for cranial motor neurons. Although the branchial arches also had general growth-promoting effects on all motor neuron subpopulations, they chemoattracted different axial levels differentially, with motor neurons from the caudal hindbrain showing the most striking response. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 101,114, 2002 [source] Accelerated nervous system development contributes to behavioral efficiency in the laboratory mouse: A behavioral review and theoretical proposalDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2001Ian Q. Whishaw Abstract The emergence of the laboratory mouse as a favored species for genetic research has posed a number of problems for scientists interested in the reflection of genetic influences in mouse behavior. It is commonly thought that rat behavior, which has been studied more extensively than mouse behavior, could be easily generalized to mice. In this article, a number of categories of behavior displayed by the mouse (motor, spatial, defensive, social) are reviewed and contrasted with the same categories of behavior displayed by the rat. The comparison suggests that mouse behavior is simpler and more dependent upon elementary actions than the behavior of the rat. We suggest that the behavioral simplification in the mouse adapts it for a different ecological niche than that occupied by the rat. We propose that this simplification may be mediated by accelerated brain maturation during development. We further propose that this developmental acceleration in the mouse renders it less dependent upon complex social behavior and plastic nervous system changes associated with learning than the rat. This difference poses problems for the development of relevant methods of behavioral analysis and interpretation. Since the mouse's biological adaptations will be reflected in laboratory behavior, suggestions are made for behavioral approaches to the study and interpretation of mouse behavior. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 151,170, 2001 [source] Generality with specificity: the dynamic field theory generalizes across tasks and time scalesDEVELOPMENTAL SCIENCE, Issue 4 2008Vanessa R. Simmering A central goal in cognitive and developmental science is to develop models of behavior that can generalize across both tasks and development while maintaining a commitment to detailed behavioral prediction. This paper presents tests of one such model, the Dynamic Field Theory (DFT). The DFT was originally proposed to capture delay-dependent biases in spatial recall and developmental changes in spatial recall performance. More recently, the theory was generalized to adults' performance in a second spatial working memory task, position discrimination. Here we use the theory to predict a specific, complex developmental pattern in position discrimination. Data with 3- to 6-year-old children and adults confirm these predictions, demonstrating that the DFT achieves generality across tasks and time scales, as well as the specificity necessary to generate novel, falsifiable predictions. [source] Bilingual experience and executive functioning in young childrenDEVELOPMENTAL SCIENCE, Issue 2 2008Stephanie M. Carlson Advanced inhibitory control skills have been found in bilingual speakers as compared to monolingual controls (Bialystok, 1999). We examined whether this effect is generalized to an unstudied language group (Spanish-English bilingual) and multiple measures of executive function by administering a battery of tasks to 50 kindergarten children drawn from three language groups: native bilinguals, monolinguals (English), and English speakers enrolled in second-language immersion kindergarten. Despite having significantly lower verbal scores and parent education/income level, Spanish-English bilingual children's raw scores did not differ from their peers. After statistically controlling for these factors and age, native bilingual children performed significantly better on the executive function battery than both other groups. Importantly, the relative advantage was significant for tasks that appear to call for managing conflicting attentional demands (Conflict tasks); there was no advantage on impulse-control (Delay tasks). These results advance our understanding of both the generalizability and specificity of the compensatory effects of bilingual experience for children's cognitive development. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||