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Similar Models (similar + models)
Selected AbstractsParticipation of children with cerebral palsy is influenced by where they liveDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 5 2004Donna Hammal MSc The study aimed to determine whether degree of participation of children with cerebral palsy (CP) is influenced by where they live, as predicted by the social model of disability. Ninety-two per cent children with CP resident in Northern England and born 1991-1996 were entered into the study. Participation was measured by the Lifestyle Assessment Score and its six component domain scores. Regression analysis was used to investigate variations in participation. There were 443 children (265 male, 178 female; mean age 4 years 8 months [SD1 year 1 month] at time of assessment) in the study. In the regression analysis the following factors remained significant with regard to level of participation: type of CP (167 with hemiplegia, and of those remaining 240 with bilateral spasticity); intellectual impairment (105 with IQ<50,113 with IQ 50 to 70, and 225 with IQ>70); presence of seizures (115 with active epilepsy); walking disability (114 unable to walk, 81 restricted and needing aids, 186 restricted but unaided, 62 unrestricted); communication problems (61 no formal communication, 51 use alternative formal methods, 126 some delay or difficulty, 205 no communication problems). After adjustment for these factors, there were significant variations with regard to level of participation in the Lifestyle Assessment Score by district of residence. The magnitude of these variations in Lifestyle Assessment Score between districts is similar to that accounted for by severe intellectual impairment. Similar models were obtained for four of the six domain scores. For one of these four, restriction of social interaction, the significant variation between districts was minimally influenced by the underlying type of CP, walking ability, or presence of seizures. Higher levels of participation among children with CP are associated with residence in certain districts. This is not attributable to variations in case-mix or functional capacity of the children. Participation of children with disability is partly a product of their environment. [source] Comparison of different algorithms to calculate electrophoretic mobility of analytes as a function of binary solvent compositionELECTROPHORESIS, Issue 10 2003Abolghasem Jouyban Abstract Ten different mathematical models representing the electrophoretic mobility of analytes in capillary electrophoresis in mixed solvents of different composition have been compared using 32 experimental data sets. The solvents are binary mixtures of water-methanol, water-ethanol and methanol-ethanol, respectively. Mean percentage deviation (MPD), overall MPD (OMPD) and individual percentage deviation (IPD) have been considered as comparison criteria. The results showed that a reorganized solution model, namely the combined nearly ideal binary solvent/Redlich-Kister equation, is the most accurate model among other similar models concerning both correlation ability and prediction capability. [source] Dispute resolution in federal systemsINTERNATIONAL SOCIAL SCIENCE JOURNAL, Issue 167 2001Michael Crommelin This article deals selectively with four broad approaches to conflict management in federal systems of government: formal dispute resolution,informal dispute resolution, dispute avoidance, and popular dispute resolution. Courts undertake the task of formal dispute resolution through judicial review: issues of current significance include judicial concepts of federalism, the reference jurisdiction, Scottish devolution, and supranational federalism and the European Court of Justice. Examples of informal dispute resolution are few. The South African Constitution includes a provision, requiring parties to an intergovernmental dispute to exhaust all other remedies before resorting to litigation. The dispute resolution process contained in chapter 20 of the North American Free Trade Agreement may stimulate experimentation with similar models in federal systems. Dispute avoidance techniques are many and varied; they include the drafting of constitutional instruments and the use of intergovernmental forums within and outside the constitutional framework. The electoral process may be employed in federal systems to determine the fate of governments, specific legislative measures and proposed constitutional amendments. Each federal society has its own culture of conflict management, which exerts a subtle but significant influence on the operation of, and the relationship among, dispute resolution systems. [source] An investigation of genetic algorithms for the optimization of multi-objective fisheries bioeconomic modelsINTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 1 2000S.J. Mardle Abstract The use of genetic algorithms (GA) for optimization problems offers an alternative approach to the traditional solution methods. GA follow the concept of solution evolution, by stochastically developing generations of solution populations using a given fitness statistic, for example the achievement function in goal programs. They are particularly applicable to problems which are large, non-linear and possibly discrete in nature, features that traditionally add to the degree of complexity of solution. Owing to the probabilistic development of populations, GA do not distinguish solutions, e.g. local optima from other solutions, and therefore cannot guarantee optimality even though a global optimum may be reached. In this paper, a non-linear goal program of the North Sea demersal fisheries is used to develop a genetic algorithm for optimization. Comparisons between the GA approach and traditional solution methods are made, in order to measure the relative effectiveness. General observations of the use of GA in multi-objective fisheries bioeconomic models, and other similar models, are discussed. [source] Stochastic generator of chemical structure.JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 6 2001Abstract A novel computational technique to generate close-to-equilibrium crosslinked polymeric systems is proposed. Compared to the current state-of-the-art equilibration methods, the new technique appears to be faster by several orders of magnitude. The main advantage of the technique is that one can circumvent the bottlenecks in configuration space that inhibit relaxation in molecular dynamics or Monte Carlo simulations. The problem of polymer equilibration described by continuous equations in molecular dynamics is reduced to a discrete representation where solutions are approximated by simple algorithms. In the current study, a series of coarse-grained, united-atom, and fully atomistic crosslinked networks has been generated. Network statistics and topology, X-ray scattering intensities, and elastic properties are tested vs. experimental results and similar models generated using molecular dynamics and Monte Carlo simulations. The results demonstrate the efficiency of this new method for generating large realistic polymeric systems up to 1.4 M atoms. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 580,590, 2001 [source] PROPOSAL OF ECTOCARPUS SILICULOSUS (ECTOCARPALES, PHAEOPHYCEAE) AS A MODEL ORGANISM FOR BROWN ALGAL GENETICS AND GENOMICS,JOURNAL OF PHYCOLOGY, Issue 6 2004Akira F. Peters The emergence of model organisms that permit the application of a powerful combination of genomic and genetic approaches has been a major factor underlying the advances that have been made in the past decade in dissecting the molecular basis of a wide range of biological processes. However, the phylogenetic distance separating marine macroalgae from these model organisms, which are mostly from the animal, fungi, and higher plant lineages, limits the latters' applicability to problems specific to macroalgal biology. There is therefore a pressing need to develop similar models for the macroalgae. Here we describe a survey of potential model brown algae in which particular attention was paid to characteristics associated with a strong potential for genomic and genetic analysis, such as a small nuclear genome size, sexuality, and a short life cycle. Flow cytometry of nuclei isolated from zoids showed that species from the Ectocarpales possess smaller haploid genomes (127,290 Mbp) than current models among the Laminariales (580,720 Mbp) and Fucales (1095,1271 Mbp). Species of the Ectocarpales may complete their life histories in as little as 6 weeks in laboratory culture and are amenable to genetic analyses. Based on this study, we propose Ectocarpus siliculosus (Dillwyn) Lyngbye as an optimal choice for a general model organism for the molecular genetics of the brown algae. [source] Interstellar extinction and polarization , a spheroidal dust grain approach perspectiveMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2010H. K. Das ABSTRACT We extend and investigate the spheroidal model of interstellar dust grains used to simultaneously interpret the observed interstellar extinction and polarization curves. We compare our model with similar models recently suggested by other authors, study its properties and apply it to fit the normalized extinction A(,)/AV and the polarizing efficiency P(,)/A(,) measured in the near-infrared to far-ultraviolet region for several stars seen through one large cloud. We conclude that the model parameter , being the angle between the line of sight and the magnetic field direction can be more or less reliably determined from comparison of the theory and observations. This opens a way to study the spatial structure of interstellar magnetic fields by using multiwavelength photometric and polarimetric observations. [source] Dorsal caudal tail and sciatic motor nerve conduction studies in adult mice: Technical aspects and normative dataMUSCLE AND NERVE, Issue 6 2010Robin H. Xia MD Abstract Mice provide an important tool to investigate human neuromuscular disorders. The variability of electrophysiological techniques limits direct comparison between studies. The purpose of this study was to establish normative motor nerve conduction data in adult mice. The dorsal caudal tail nerve and sciatic nerve motor conduction studies were performed bilaterally on restrained anesthetized adult mice. The means and standard deviations for each electrophysiological parameter were determined in normal mice. Data were compared with inflammatory demyelinating polyneuropathy mice to determine whether these parameters discriminate between normal and abnormal peripheral nerves. Normal adult mice had a distal latency of 0.89 (±0.17) ms and 0.75 (±0.09) ms, distal compound motor unit action potential amplitude of 13.2 (±5.9) mV and 28.1 (±8.3) mV, and conduction velocity of 74.6 (±9.0) m/s and 76.5 (±8.3) m/s, respectively. These data were validated by the finding of statistically significant differences in several electrophysiological parameters that compared normal and polyneuropathy-affected mice. A standardized method for motor nerve conduction studies and associated normative data in mice should facilitate comparisons of disease severity and response to treatment between studies that use similar models. This would assist in the process of translational therapeutic drug design in neuromuscular disorders. Muscle Nerve, 2010 [source] Semi-classical calculation of resonant states of a charged particle interacting with a metallic surfacePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 10 2005John Jairo Zuluaga Abstract We assess the applicability of the semi-classical approach of Herman,Kluk with filter diagonalization to determine resonant states of either the electron-surface system or the ion-surface system. An effective potential model of the interaction of an electron with a ruthenium metallic surface is used. The evolution of the wave-function and the resonant states of this system are calculated. Analogous results for the interaction of the system formed by the H, and the ruthenium surface are presented. For the calculation of the resonances, the semi-classical wave-function is found, and the autocorrelation function between the initial and final wave-functions is calculated, from which the position and width of the resonances are extracted by using the harmonic inversion by filter diagonalization. The results are compared with results available in the literature for similar models obtained by quantum calculations using fast Fourier Transform. The positions of the lower-lying resonances found with the semi-classical and quantum approaches match closely, while the values of the widths of the resonances show larger discrepancies. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Modelling of reserve carbohydrate dynamics, regrowth and nodulation in a N2 -fixing tree managed by periodic pruningsPLANT CELL & ENVIRONMENT, Issue 10 2000F. Berninger ABSTRACT We used a modified transport resistance approach to model legume tree growth, nodulation and dynamics of reserve carbohydrates after pruning. The model distributes growth between roots and shoots applying the transport resistance approach. Within shoots, growth is divided into leaves, branches and stems applying the pipe model theory. The model also accounts for the metabolic differences of principal N sources, nitrate, ammonium and atmospheric dinitrogen, in a mechanistic way. We compared the simulation results with measured biomass dynamics of Gliricidia sepium (Jacq.) Walp. (Papilionaceae: Robinieae) under humid and subhumid tropical conditions. Comparison showed that the biomass production predicted by the model is close to measured values. Total N2 fixation is also similar to measured values. Qualitatively the model increases the proportion of N2 fixation if roots acquire less mineral N. In the present study, the general form of the model is discussed and compared with similar models. The results encourage the use of this approach for studying biomass dynamics of legume trees under the scheme of periodic prunings. Also, it shows that process-based models have potential in the simulation of trees disturbed by prunings, herbivory or similar factors. [source] LiveBench-1: Continuous benchmarking of protein structure prediction serversPROTEIN SCIENCE, Issue 2 2001Janusz M. Bujnicki Abstract We present a novel, continuous approach aimed at the large-scale assessment of the performance of available fold-recognition servers. Six popular servers were investigated: PDB-Blast, FFAS, T98-lib, GenTHREADER, 3D-PSSM, and INBGU. The assessment was conducted using as prediction targets a large number of selected protein structures released from October 1999 to April 2000. A target was selected if its sequence showed no significant similarity to any of the proteins previously available in the structural database. Overall, the servers were able to produce structurally similar models for one-half of the targets, but significantly accurate sequence-structure alignments were produced for only one-third of the targets. We further classified the targets into two sets: easy and hard. We found that all servers were able to find the correct answer for the vast majority of the easy targets if a structurally similar fold was present in the server's fold libraries. However, among the hard targets,where standard methods such as PSI-BLAST fail,the most sensitive fold-recognition servers were able to produce similar models for only 40% of the cases, half of which had a significantly accurate sequence-structure alignment. Among the hard targets, the presence of updated libraries appeared to be less critical for the ranking. An "ideally combined consensus" prediction, where the results of all servers are considered, would increase the percentage of correct assignments by 50%. Each server had a number of cases with a correct assignment, where the assignments of all the other servers were wrong. This emphasizes the benefits of considering more than one server in difficult prediction tasks. The LiveBench program (http://BioInfo.PL/LiveBench) is being continued, and all interested developers are cordially invited to join. [source] Pricing a Network Good To Deter EntryTHE JOURNAL OF INDUSTRIAL ECONOMICS, Issue 4 2000Drew Fudenberg This paper develops a model of pricing to deter entry by a sole supplier of a network good. We show that the installed user base of a network good can serve a preemptive function similar to that of an investment in capacity if the entrant's good is incompatible with the incumbent's good and there are network externalities in demand. Consequently, the threat of entry can lead the incumbent to set low prices. We identify some factors that should be considered in thinking about the welfare effects of entry deterrence in this and similar models. [source] The evolution of fitness in life-history theoryBIOLOGICAL REVIEWS, Issue 3 2000JON E. BROMMER ABSTRACT Theory concerning the evolution of life history (the schedule of reproduction and survival) focuses on describing the life history which maximises fitness. Although there is an intuitive link between life history and fitness, there are in fact several measures of the ,black box' concept of fitness. There has been a debate in the bio-mathematical literature on the predictive difference between the two most commonly used measures; intrinsic rate of increase r and net reproductive ratio R0. Although both measures aim to describe fitness, models using one of the measures may predict the opposite of similar models using the other measure, which is clearly undesirable. Here, I review the evolution of these fitness measures over the last four decades, the predictive differences between these measures and the resulting shift of the fitness concept. I focus in particular on some recent developments, which have solved the dilemma of predictive differences between these fitness measures by explicitly acknowledging the game-theoretical nature of life-history evolution. [source] How clinicians in neonatal care see the introduction of neonatal nurse practitionersACTA PAEDIATRICA, Issue 2 2002ME Redshaw The aim of this study was to investigate the views of UK clinicians in neonatal care who were working with nurses trained as neonatal nurse practitioners (NNPs). A questionnaire survey was used with a total sample of senior clinicians in the 66 neonatal units with one or more qualified NNPs. The main outcome measures were type and frequency of response, and similar data from NNPs were used to make comparisons. Data were returned from 57 of the 66 clinicians contacted (86%). NNP clinical practice as perceived by them was largely similar to that recorded by NNPs, though the clinicians expected more NNP involvement in some procedures (inserting central venous lines, umbilical arterial catheters, chest drains and peripheral arterial cannulae) than was actually found. Perceptions of the NNP role were similar, though the clinicians were significantly less likely to see taking a case-load, conducting a ward round, accepting outside referrals and taking charge of emergency transfers as integral elements. Reflections on the utilization of NNPs in neonatal care and the impact on junior medical staff education referred to NNPs filling gaps, a reduction in the intensity of work, improvements in training and in the quality of care. Conclusion: The introduction of NNPs is seen positively from the perspective of clinicians working alongside them in neonatal care. The development of similar models of care in countries where the introduction of NNPs is being considered is likely to be similarly supported. [source] | ||||||||||||||||||||||