MoSuMo: A Semantic Web service to generate electrostatic potentials across solvent excluded protein surfaces and binding pockets

Investigations of molecular interactions can benefit from knowledge of the regions that correspond to binding sites and electrostatic potentials across molecular surfaces. In support of simulations aimed at a coarser level of granularity than molecular dynamics, we have developed MoSuMo, a SADI-based Semantic Web service for generating molecular surfaces from a set of 3D atomic coordinates. MoSuMo's service input requires a Protein Data Bank (PDB) identifier from which it obtains the PDB entry and for which it generates electrostatic potentials as vertex values across a geometric mesh that represents the molecular surface. Service inputs and outputs are specified as restrictions on classes from the Semanticscience Integrated Ontology (SIO), which is formalized using the Web Ontology Language (OWL). Binding sites containing their ligands are identified and described as sub-collections of surface vertices. Thus, MoSuMo provides a semantic web service for investigating molecular interactions including visualization.     

Methodological issues in the validation of implicit measures: Comment on De Houwer, Teige-Mocigemba, Spruyt, and Moors (2009).

J. De Houwer, S. Teige-Mocigemba, A. Spruyt, and A. Moors’s (see record 2009-05290-001) normative analysis of implicit measures provides an excellent clarification of several conceptual ambiguities surrounding the validation and use of implicit measures. The current comment discusses an important, yet unacknowledged, implication of J. De Houwer et al.’s analysis, namely, that investigations addressing the proposed implicitness criterion (i.e., does the relevant psychological attribute influence measurement outcomes in an automatic fashion?) will be susceptible to fundamental misinterpretations if they are conducted independently of the proposed what criterion (i.e., is the measurement outcome causally produced by the psychological attribute the measurement procedure was designed to assess?). As a solution, it is proposed that experimental validation studies should be combined with a correlational approach in order to determine whether a given manipulation influenced measurement scores via variations in the relevant psychological attribute or via secondary sources of systematic variance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Torque-bias profile for improved tracking of the Deep Space Networkantennas

Measurements at the drives of the NASA Deep Space Network (DSN) antennas indicated that the small gap between gear teeth was causing backlash at the gearboxes and elevation bullgear. Left uncorrected, backlash will deteriorate the antenna's pointing precision. At DSN, the backlash was eliminated by implementing two identical drives that impose two nonidentical torques (a.k.a. torque bias, or counter-torque). The difference between these two torques depends on the antenna load, and is shaped by the drive's electronic circuits. The paper explains the shaping principles of the circuit, and shows how the circuits can be modified to improve the antenna dynamics under external disturbances     

Design and performance of the monopulse control system

Ka-band (32 GHz) monopulse tracking has been chosen for the upcoming NASA missions. This decision requires an increased pointing accuracy for the Deep Space Network antenna servo systems that can be maintained in a noisy environment. The noise sources include wind gusts, encoder imperfections, and receiver noise. This article describes the selection of the position and monopulse controllers for the improved tracking accuracy, and presents the results of linear and non-linear simulations to confirm that servo performance will meet the requirements     

A learning algorithm for the classification of dynamic events using a neuron-like dynamic tree

The use of neuron-like networks (NN) for pattern recognition has a well-established history and numerous current applications. Most such applications are to static patterns while the theory developed for temporally changing visual patterns usually assumes rigid objects with well-defined boundaries. In applications such as analysis of cardiac movement, however, the object is flexible and the images are often imperfect. the authors current model for NN activity captures the dynamic nature of the signal processing of the neural dendritic tree, allowing both faster learning of dynamic patterns and a very reduced number of receptors required for distinguishing diverse types of motion or changes. the design of the NN model is presented and a training algorithm which exhibits in practice extremely fast convergence (as few as 15 iterations) to near optimal recognition behavior is introduced. © 1993 John Wiley & Sons, Inc.     

Data errors in the computation of free motion

Input data in the computation of free motion (the inertia and stiffness matrices) contain some errors. These errors generate errors of output data (the natural frequency vector, the natural mode vectors). In this paper the relationships between errors of input and output data in the computation of free motion are derived. This analysis is applied to the finite element method. The paper presents program ERROR, which computes the errors of the natural frequencies created by the inertia matrix errors. An example of the influence of the errors of the mass and of the mass moment of inertia on the natural frequencies of a ship hull is presented.     

Servo-Performance Parameters of the NASA Deep Space Network Antennas

The performance of an antenna control system is evaluated using performance parameters such as settling time, bandwidth, steady-state error in rate offsets, and antenna root-mean-square servo error while tracking in wind gusts. The performance parameters are measured in the field, or obtained through analysis and simulations. Limited access time to antennas, incomplete test equipment, limited test/analysis time, and partial models do not allow determination of all the parameters. However, field practice and analytical results indicate correlations among them; hence, even incomplete knowledge of the performance parameters would allow for estimation of the missing parameters. This paper investigates the relationships of the antenna performance parameters as a function of controller gains. It also establishes the interrelationships among the parameters. It does this for an idealized (or rigid) antenna, and extends the relationships to the NASA Deep Space Network antennas (flexible structures with dish sizes of 34 or 70 meters). The results obtained should simplify antenna testing, and allow for better performance evaluation from limited data.     

Associative and propositional processes in evaluation: An integrative review of implicit and explicit attitude change.

A central theme in recent research on attitudes is the distinction between deliberate, "explicit" attitudes and automatic, "implicit" attitudes. The present article provides an integrative review of the available evidence on implicit and explicit attitude change that is guided by a distinction between associative and propositional processes. Whereas associative processes are characterized by mere activation independent of subjective truth or falsity, propositional reasoning is concerned with the validation of evaluations and beliefs. The proposed associative-propositional evaluation (APE) model makes specific assumptions about the mutual interplay of the 2 processes, implying several mechanisms that lead to symmetric or asymmetric changes in implicit and explicit attitudes. The model integrates a broad range of empirical evidence and implies several new predictions for implicit and explicit attitude change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)