bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strategies for the control of voluntary movements with one mechanical degree of freedom
Authors: Gottlieb Gerald L. , Corcos Daniel M. , Agarwal Gyan C. 
Published: February 2010

AbstractA theory is presented to explain how accurate, single-joint movements are controlled. The theory applies to movements across different distances, with different inertial loads, toward targets of different widths over a wide range of experimentally manipulated velocities. The theory is based on three propositions. (1) Movements are planned according to “strategies” of which there are at least two: a speed-insensitive (SI) and a speed-sensitive (SS) one. (2) These strategies can be equated with sets of rules for performing diverse movement tasks. The choice between SI and SS depends on whether movement speed and/or movement time (and hence appropriate muscle forces) must be constrained to meet task requirements. (3) The electromyogram can be interpreted as a low-pass filtered version of the controlling signal to the motoneuron pools. This controlling signal can be modelled as a rectangular excitation pulse in which modulation occurs in either pulse amplitude or pulse width. Movements to different distances and with loads are controlled by the SI strategy, which modulates pulse width. Movements in which speed must be explicitly regulated are controlled by the SS strategy, which modulates pulse amplitude. The distinction between the two movement strategies reconciles many apparent conflicts in the motor control literature.
Reconciling Fechner and Stevens: Toward a unified psychophysical law
Authors: Krueger Lester E. 
Published: February 2010

AbstractHow does subjective magnitude,S. increase as physical magnitude or intensity,I, increases? Direct ratings (magnitude scales; partition or category scales) can be fitted by the power function,S = aIb, in which SequalsIraised to a power or exponent,b, and multiplied by a measure constant,a. The exponent is typically about twice as large for the magnitude scale (Stevens) as for the corresponding partition or category scale, but the higher exponent may be explained by the overly expansive way people use numbers in making magnitude estimations. The partition or category scale and the adjusted (for the use of number) magnitude scale for a given modality or condition generally agree with the neurelectric scale and the summated just noticeable difference (jnd) scale. A unified psychophysical law is proposed in which each jnd has the same subjective magnitude for a given modality or condition, subjective magnitude increases as approximately a power function of physical magnitude with the exponent ranging from near 0 to 1 (compressive function), and subjective magnitude depends primarily on peripheral sensory processes, that is, no nonlinear central transformations occur. An undue reliance on Weber's law blinded Fechner to the fact that the true psychophysical scale is approximately a power function. Rejecting Weber's law, which is not valid, means that we no longer have to choose between letting the summated jnd scale be a logarithmic function (Fechner's law) and introducing a nonlinear central transformation to make it into a power function (Brentano–Ekman-Teghtsoonian's law). Fechner and Stevens erred equally about the true psychophysical power function, whose exponent lies halfway between that of Fechner (an exponent approaching zero) and that of Stevens. To be reconciled, Fechnerians must give up the assumptions that Webers law is valid and that the jnd has the same subjective magnitude across modalities and conditions; Stevensians must give up the assumption that the unadjusted (for the use of number) magnitude scale is a direct measure of subjective magnitude.
A solution to the tag-assignment problem for neural networks
Authors: Strong Gary W. , Whitehead Bruce A. 
Published: February 2010

AbstractPurely parallel neural networks can model object recognition in brief displays – the same conditions under which illusory conjunctions (the incorrect combination of features into perceived objects in a stimulus array) have been demonstrated empirically (Treisman 1986; Treisman & Gelade 1980). Correcting errors of illusory conjunction is the “tag-assignment” problem for a purely parallel processor: the problem of assigning a spatial tag to nonspatial features, feature combinations, and objects. This problem must be solved to model human object recognition over a longer time scale. Our model simulates both the parallel processes that may underlie illusory conjunctions and the serial processes that may solve the tag-assignment problem in normal perception. One component of the model extracts pooled features and another provides attentional tags that correct illusory conjunctions. Our approach addresses two questions: (i) How can objects be identified from simultaneously attended features in a parallel, distributed representation? (ii) How can the spatial selectional requirements of such an attentional process be met by a separation of pathways for spatial and nonspatial processing? Our analysis of these questions yields a neurally plausible simulation of tag assignment based on synchronizing feature processing activity in a spatial focus of attention.
Addiction is not as puzzling as it seems
Authors: Orford Jim 
Published: February 2010

AbstractHeyman's target article seeks to resolve the apparent paradox surrounding the issue of control in relation to addictive behaviour. The present commentary argues that addiction is in fact less paradoxical and more easily understandable than Heyman supposes. A fully satisfactory model of addiction, however, requires a more multifaceted approach than that provided by the type of behavioural choice theory favoured by Heyman.
The stage question in cognitive-developmental theory
Authors: Brainerd Charles J. 
Published: February 2010

AbstractThe term “stage” appears to be used in three general senses in theories of behavioral development: (a) as a metaphor: (b) as a description of behaviors that undergo age change; (c) as an explanation of age-related changes in behavior. Although most existing stage models are purely descriptive, a few of them purport to have explanatory power. One such model, Piaget's stages of cognitive development, is considered in this paper.To be viewed as potentially explanatory, a stage model must describe some behaviors that undergo age change, posit antecedent variables believed to cause the changes, and provide procedures whereby the behavioral changes and the antecedent variables can be independently measured. Piaget's stages seem to satisfy some but not all of these requirements. Piaget's stages describe many agerelated changes in behavior, and some antecedent variables have been proposed. However, procedures do not exist for measuring the two factors independently. In lieu of such procedures, Piaget has outlined a “program” of five empirical criteria whereby the reality of his stages can ostensibly be verified. Some objections to these criteria are considered.The five criteria in Piaget's program are invariant sequence, cognitive structure, integration, consolidation, and equilibration. Three of the criteria (invariant sequence, integration, and consolidation) lead to the same sorts of empirical predictions (culturally universal sequences in the acquisition of certain behaviors). Such predictions are subject to the objection that Piagetian invariant sequences are often measurement sequences. A measurement sequence is said to occur when some late-appearing behavior consists of some earlier-appearing behavior plus additional things. The cognitive structure criterion is subject to at least three criticisms: First, it yields, at most, descriptions of behavior; second, these are often nothing more than descriptions of task structure; third, they cannot be regarded as unique to the given stages for which they are posited. The fifth criterion, equilibration, generates some predictions that might be considered as prima facie evidence for the existence of stages. However, these predictions conflict with the current data base on Piaget's stages.It is concluded that there is no compelling support for Piaget's hypothesis that his cognitive stages do more than describe age-related changes in behavior. Since explanatory statements involving stages appear with some regularity in Piagetian and neo-Piagetian writings, there are grounds for supposing this conclusion to be nontrivial.
Improving protein secondary structure prediction using a simplek-mer model
Authors: Madera Martin , Calmus Ryan , Thiltgen Grant , Karplus Kevin , Gough Julian 
Published: February 2010

AbstractMotivation: Some first order methods for protein sequence analysis inherently treat each position as independent. We develop a general framework for introducing longer range interactions. We then demonstrate the power of our approach by applying it to secondary structure prediction; under the independence assumption, sequences produced by existing methods can produce features that are not protein like, an extreme example being a helix of length 1. Our goal was to make the predictions from state of the art methods more realistic, without loss of performance by other measures.Results: Our framework for longer range interactions is described as a k-mer order model. We succeeded in applying our model to the specific problem of secondary structure prediction, to be used as an additional layer on top of existing methods. We achieved our goal of making the predictions more realistic and protein like, and remarkably this also improved the overall performance. We improve the Segment OVerlap (SOV) score by 1.8%, but more importantly we radically improve the probability of the real sequence given a prediction from an average of 0.271 per residue to 0.385. Crucially, this improvement is obtained using no additional information.Availability: http://supfam.cs.bris.ac.uk/kmerContact: gough@cs.bris.ac.uk
Small-sample precision of ROC-related estimates
Authors: Hanczar Blaise , Hua Jianping , Sima Chao , Weinstein John , Bittner Michael , Dougherty Edward R. 
Published: February 2010

Abstract
Motivation: The receiver operator characteristic (ROC) curves are commonly used in biomedical applications to judge the performance of a discriminant across varying decision thresholds. The estimated ROC curve depends on the true positive rate (TPR) and false positive rate (FPR), with the key metric being the area under the curve (AUC). With small samples these rates need to be estimated from the training data, so a natural question arises: How well do the estimates of the AUC, TPR and FPR compare with the true metrics?
Results: Through a simulation study using data models and analysis of real microarray data, we show that (i) for small samples the root mean square differences of the estimated and true metrics are considerable; (ii) even for large samples, there is only weak correlation between the true and estimated metrics; and (iii) generally, there is weak regression of the true metric on the estimated metric. For classification rules, we consider linear discriminant analysis, linear support vector machine (SVM) and radial basis function SVM. For error estimation, we consider resubstitution, three kinds of cross-validation and bootstrap. Using resampling, we show the unreliability of some published ROC results.
Availability: Companion web site at http://compbio.tgen.org/paper_supp/ROC/roc.html
Contact: edward@mail.ece.tamu.edu
Maximal conditional chi-square importance in random forests
Authors: Wang Minghui , Chen Xiang , Zhang Heping 
Published: February 2010

Abstract
Motivation: High-dimensional data are frequently generated in genome-wide association studies (GWAS) and other studies. It is important to identify features such as single nucleotide polymorphisms (SNPs) in GWAS that are associated with a disease. Random forests represent a very useful approach for this purpose, using a variable importance score. This importance score has several shortcomings. We propose an alternative importance measure to overcome those shortcomings.
Results: We characterized the effect of multiple SNPs under various models using our proposed importance measure in random forests, which uses maximal conditional chi-square (MCC) as a measure of association between a SNP and the trait conditional on other SNPs. Based on this importance measure, we employed a permutation test to estimate empirical P-values of SNPs. Our method was compared to a univariate test and the permutation test using the Gini and permutation importance. In simulation, the proposed method performed consistently superior to the other methods in identifying of risk SNPs. In a GWAS of age-related macular degeneration, the proposed method confirmed two significant SNPs (at the genome-wide adjusted level of 0.05). Further analysis showed that these two SNPs conformed with a heterogeneity model. Compared with the existing importance measures, the MCC importance measure is more sensitive to complex effects of risk SNPs by utilizing conditional information on different SNPs. The permutation test with the MCC importance measure provides an efficient way to identify candidate SNPs in GWAS and facilitates the understanding of the etiology between genetic variants and complex diseases.
Contact: heping.zhang@yale.edu
Supplementary information: Supplementary data are available at Bioinformatics online.
On reconstruction of three-dimensional harmonic functions from discrete data
Authors: Galybin A. N. , Irša J. 
Published: February 2010

This study presents an approach for reconstruction of harmonic functions in three dimensions from the finite number of field and surface measurements. The approach, based on the Trefftz method, performs reconstruction as the best fit to the data and provides smoothness of the reconstructed function. Two particular algorithms are proposed; the first one uses specific radial basis functions and the second one is of finite element type. Either of them can be applied to analyse different data types but the latter can handle larger problems. The data types considered in this study also cover direct and inverse boundary value problems. Therefore, the proposed approach is universal and capable of dealing with both well-posed and ill-posed formulations. Examples from steady heat conduction and elastostatics are examined in order to investigate the efficiency of the approach.
Holocene persistence of wooded steppe in the Great Hungarian Plain
Authors: Magyari E.K. , Chapman J.C. , Passmore D.G. , Allen J.R.M. , Huntley J.P. , Huntley B. 
Published: February 2010

AbstractAim  We used a combination of new and previously published palaeoecological data to test three hypotheses: (1) that wooded steppe persisted in the Great Hungarian Plain throughout the Holocene; (2) that wooded steppe and steppe were most extensive between c. 9900 and 8300 cal. yr bp (the ‘Boreal steppe’ period); and (3) that Southern Continental, Pontic and Eastern Sub‐Mediterranean steppe species reached the region during the early Holocene via the ‘Lower Danube Corridor’.Location  Sarló‐hát oxbow lake, Hungary and the Eastern European wooded steppe zone.Methods  Holocene sediments deposited in the Sarló‐hát oxbow lake were subjected to pollen and microcharcoal analyses. Twelve radiocarbon age estimates were obtained to determine sediment chronology. In addition, previously published palaeoecological data from the Great Hungarian Plain were compiled, analysed and compared with previous studies in other regions of steppe and wooded steppe in eastern Europe.Results  Palynological data from two sediment cores extending to c. 11,400 cal. yr bp indicate the persistent dominance of the landscape by temperate deciduous wooded steppe throughout the Holocene, although with varying canopy composition. Warm‐continental steppe grasslands and saline tall‐grass meadows developed on edaphically constrained areas, which remained steppe‐dominated throughout the Holocene. The extent of steppe grasslands did not increase between 9900 and 8300 cal. yr bp. After c. 3100 cal. yr bp, anthropogenic activities led to the development of cultural steppe. Thermophilous steppe species of the Southern Continental, Pontic and Sub‐Mediterranean floristic elements probably reached the Great Hungarian Plain principally via the Lower Danube Corridor during the late glacial interstadial and Holocene. Eurythermic members of these elements, however, probably survived the Last Glacial Maximum in favourable microsites, extending their ranges during the Holocene from these local sources.Main conclusions  Our results confirm the Holocene persistence of wooded steppe in the Great Hungarian Plain, disprove the ‘Boreal steppe’ theory, and suggest an Early Holocene period of greater vegetation openness between 11,400 and 9900 cal. yr bp. Evidence for the post‐glacial immigration of south‐eastern steppe elements into the Carpathian Basin is equivocal: the last glacial/interglacial presence of several southern steppe species suggests that the Hungarian Plain hosted suitable habitats for them during warm and cold phases alike.
Tumour‐selective antivascular effects of the novel anti‐mitotic compound A‐318315: Anin vivorat regional haemodynamic study
Authors: Segreti Jason A , Brooks Kristin A , Marsh Kennan C , Bauch Joy L , Lan Yan , Thomas Lin C , Rosenberg Saul H , Sham Hing L , Reinhart Glenn A , Cox Bryan F , Polakowski James S 
Published: February 2010

Summary1. It has been shown that tubulin‐binding agents can destabilize cellular microtubules and suppress tumour growth; but it has also become apparent that some compounds can exert anti‐vascular effects within the neovasculature of a solid tumour. To date, the difficulty with these targets has been the ability to selectivity induce vascular damage to the tumour while leaving normal vasculature unaffected. The data presented here characterizes thein vivo, tumour selective, anti‐vascular effects of the novel tubulin‐binding agent A‐318315.2. To that purpose, we have used an anaesthetizedin vivorat model designed to quantify acute changes in regional vascular resistance (VR) in both tumour and non‐tumour vascular beds, simultaneously. Tissue‐isolated tumours (approximately 1.25 gm) with blood flow supplied by a single epigastric artery were grown in the hindlimb of adult male rats. Blood flow to the tumour, mesenteric, renal and normal (non‐tumour epigastric) arteries was measured pre‐dose and post‐dose under anaesthesia.3. A‐318315 was tested at 3, 10 and 30 mg/kg, i.v. These doses produced modest, transient increases in mean arterial pressure with little to no effect on heart rate. At peak effect, tumour VR increased to 175 ± 47, 337 ± 77 and 751 ± 151% above the baseline, for the 3, 10 and 30 mg/kg doses, respectively, whereas VR was only modestly and transiently increased in normal epigastric (88 ± 19%), mesenteric (33 ± 3.3%) and renal arteries (17 ± 8.6%).4. These data demonstrate that A‐318315 produces marked reductions in tumour blood flow in the rat at doses that exert minor effects on normal vascular function.
Effect of the specialist herbivore Luehdorfia puziloi on the performance of a woodland herbaceous plant, Asarum heterotropoides
Authors: ISHIZAKI SATOMI , NARUMI TADASHI , MIZUSHIMA MIKI , OHARA MASASHI 
Published: February 2010

AbstractPlants show many responses to herbivore damage caused by insects. We investigated the effect of the specialist leaf herbivore Luehdorfia puziloi on the performance of a deciduous forest understory perennial herb Asarum heterotropoides. We conducted artificial defoliation experiments with different levels of damage (0, 50 or 100% clipping) in the early growing period (flowering time: early May) and in the late growing period (when natural herbivory by L. puziloi larvae occurs: early June) in a natural population. Effects of the defoliation treatments on reproduction (seed‐set ratio) of A. heterotropoides in the treated year and on survival and development of the plant in the subsequent year were investigated. Severe defoliation conducted in the early period resulted in less current‐year seed production and increased regression to a dormant or non‐reproductive stage in the following year, which would reduce the probability of future flowering. In contrast, defoliation conducted in the late period had no effect on the reproduction, survival and development of A. heterotropoides. Similarly, we found no obvious correlation between the damaged leaf area during the later period and seed set. Our results show that the specialist herbivore L. puziloi did not influence the performance of A. heterotropoides by damaging the plant later in the season when it was tolerant of damage.
Mothers' depression and health‐related quality of life in neuromuscular diseases: Role of functional independence level of the children
Authors: Yılmaz Oznur , Yıldırım Sibel Aksu , Öksüz Cigdem , Atay Sibel , Turan Ebru 
Published: February 2010

AbstractBackground:  In the literature there have been studies about quality of life of parents who have children with chronic diseases. Most of these studies have focused on the stress of parents of children with neuromuscular disease (NMD), and there was no evidence to support hypothesized relationships between caregiving demands and health‐related quality of life (HRQOL). The aim of the present study was therefore to evaluate the relations between maternal depression and HRQOL and functional limitations of the children with NMD.Methods:  Forty children with a diagnosis of NMD and their mothers were included in the study. HRQOL of the mothers was assessed on the Turkish version of the Nottingham Health Profile (NHP); potential cases of depressive illness were identified on Beck Depression Inventory (BDI); and Wee‐Functional Independence Measure (Wee‐FIM) was used to evaluate of functional independence level of the children.Results:  It was found that mean total NHP score of the mothers was moderately correlated with the total FIM score and sphincter control of the child, and weakly correlated with the locomotion of the child (P < 0.001). There was moderate correlation between mothers' social isolation and children's sphincter control, social integration and total Wee‐FIM score and a weak correlation between mobility and communication scores (P < 0.001). In contrast there was no correlation between BDI scores of mothers and Wee‐FIM scores of children (P > 0.05).Conclusion:  The functional level of children with NMD is one of the factors that affect the quality of life of mothers.
Association of development of chronic lung disease of newborns with neonatal colonization of Ureaplasma and cord blood interleukin‐8 level
Authors: Yada Yukari , Honma Yoko , Koike Yasunori , Takahashi Naoto , Momoi Mariko Y. 
Published: February 2010

AbstractBackground:  The aim of the present study was to investigate the association of chronic lung disease (CLD), neonatal Ureaplasma colonization, and interleukin‐8 (IL‐8) level of cord blood in preterm infants.Methods:  In 77 infants of <32 weeks gestation, the relationship between IL‐8 level of cord blood, neonatal colonization of Ureaplasma, histological chorioamnionitis (CAM), and development of CLD was studied.Results:  Five infants died and 29 infants developed CLD. The CLD group had significantly lower gestation (mean ± SD: 26.6 ± 1.8 weeks) compared with the infants without CLD (28.9 ± 1.9 weeks, P < 0.0001). Logistic analysis showed that the development of CLD was associated with gestational age (odds ratio [OR], 0.5; 95% confidence interval (CI): 0.4–0.8) and Ureaplasma colonization (OR, 4.1; 95%CI: 1.2–14.4). Ureaplasma colonization was also associated with CAM (OR, 6.5; 95%CI: 1.8–23.5), absence of respiratory distress syndrome (OR, 6.2; 95%CI: 1.3–30.5), and development of CLD (OR, 4.0; 95%CI: 1.1–15.3). Elevated cord blood IL‐8 ≥100 pg/mL was associated with female sex and the isolation of microorganisms (OR, 49.4; 95%CI: 4.6–525).Conclusion:  The development of CLD defined by oxygen requirement at 36 weeks was associated with neonatal Ureaplasma colonization but not with IL‐8 level of cord blood. Elevated cord blood IL‐8 was associated with neonatal microorganisms isolation.