Goal-directed responding is sensitive to lesions to the prelimbic cortex or basolateral nucleus of the amygdala but not to their disconnection.

The current view of instrumental conditioning indicates that performance in the early stage of training is maintained by a representation of the outcome, as indexed by its sensitivity to changes in the value of the reward. In the present study, the authors tested the effects of a disconnection of the prelimbic cortex (PL) and the basolateral nucleus of the amygdale (BLA), using an asymmetric lesion procedure, to determine whether these structures interact sequentially as part of a corticolimbic system. In marked contrast to the effects of bilateral lesions of the PL or the BLA, which both altered rats' sensitivity to outcome devaluation, the disconnection of these 2 brain areas was without an effect on outcome devaluation. These results demonstrate that the PL and the BLA mediate different aspects of outcome representation in goal-directed responding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

Micro- and Nanostructure of Zn Whiskers and Their Coating

To understand the mechanisms at the origin of whisker formation and growth, a Zn-electroplated steel prone to whiskering was studied. Several samples were prepared from different locations of the electroplated plate. Care was taken to extract samples at the root, in the nodule, or away from whiskers. Samples were characterized using electron backscattered diffraction (EBSD). Crystallographic data from EBSD show that recrystallized regions are present at the root of whiskers and in their nodules. These observations support whisker growth models based on recrystallization. In addition, atom probe tomography samples were prepared in the center of whiskers. The distribution of Zn atoms is almost homogeneous and no impurities are present in the whiskers.     

Heat source identification and on-line temperature control by a Branch Eigenmodes Reduced Model

This paper presents the advantages of a Branch Eigenmodes Reduced Model used in a control process of a heating system.The experimental setup is a 3D heat conductive system in which a heat source is set. First, the reduced model is used to solve the non-linear Inverse Heat Conduction Problem: identification of the heat source strength variations from time-varying temperatures. Then, the reduced model is used to control hot points in the system. The objective of the method is to allow sequential temperature control by decreasing the computation time necessary for the simulation.     

Pronunciation prediction with Default&Refine

The Default&Refine algorithm is a new rule-based learning algorithm that was developed as an accurate and efficient pronunciation prediction mechanism for speech processing systems. The algorithm exhibits a number of attractive properties including rapid generalisation from small training sets, good asymptotic accuracy, robustness to noise in the training data, and the production of compact rule sets. We describe the Default&Refine algorithm in detail and demonstrate its performance on two benchmarked pronunciation databases (the English OALD and Flemish FONILEX pronunciation dictionaries) as well as a newly-developed Afrikaans pronunciation dictionary. We find that the algorithm learns more efficiently (achieves higher accuracy on smaller data sets) than any of the alternative pronunciation prediction algorithms considered. In addition, we demonstrate the ability of the algorithm to generate an arbitrarily small rule set in such a way that the trade-off between rule set size and accuracy is well controlled. A conceptual comparison with alternative algorithms (including Dynamically Expanding Context, Transformation-Based Learning and Pronunciation by Analogy) clarifies the competitive performance obtained with Default&Refine.     

Pragmatic software tools for water reuse evaluation in a factory

The optimal use of process water becomes increasingly important since natural water resources are heavily solicited by a growing economy. Two steps can be considered in the process water optimization. A first step is the inventory of the different process streams in the process water network. Pure mathematical modeling of a dynamic water network is extremely complicated and expensive. As an approximation, the use of a steady-state network node model within commercial software is accepted to set up a water balance. Sophisticated software tools are available but common solver software may offer an alternative. A second step is the water “pinch” which searches for an optimal use of process water by combining sources and sinks, taking into account contaminant concentrations of process streams. Sophisticated pinch software can be applied but it is also possible to implement a simplified combinatory approach. Such approach can be pragmatically programmed in e.g., Visual Basic. Such tool allows for a first evaluation of the complex combinatory sources–sinks problem, enabling a low cost and easy-to-handle first interpretation of possible water-reuse opportunities. This could stimulate a further enhanced analysis with more advanced software tools and therefore promote a sustainable use of process water in the industrialized world.     

A collaborative wheelchair system.

This paper describes a novel robotic wheelchair, and reports experiments to evaluate its efficiency and understand how human operators use it. The concept at the heart of the collaborative wheelchair assistant (CWA) is to rely on the user's motion planning skills while assisting the maneuvering with flexible path guidance. The user decides where to go and controls the speed (including start and stop), while the system guides the wheelchair along software-defined guide paths. An intuitive path editor allows the user to avoid dangers or obstacles online and to modify the guide paths at will. By using the human sensory and planning systems, no complex sensor processing or artificial decision system is needed, making the system safe, simple, and low-cost. We investigated the performance of the CWA on its interaction with able-bodied subjects and motion efficiency. The results show that path guidance drastically simplifies the control. Using the CWA, the wheelchair user needs little effort from the first trial, while moving efficiently with a conventional wheelchair requires adaptation.     

The mechanical behaviour of porous austenitic stainless steel fibre structures

The mechanical properties of metal fibre porous structures were studied in the light of their potential application as surface coatings of implants. Stainless steel AISI 316 L fibres with diameters of 50 and 100μm were compacted and sintered. The variation of the modulus of elasticity with density, as obtained in tension, corresponds closely with theoretical models. The ultimate failure of the tensile specimens proceeds through the fibres, and not through the sinter bonds, except at lower densities. Differences in yield strength between 50 and 100 μm fibre tensile specimens are explained on the basis of the onset of plastic deformation of the individual fibres. Upon compression the modulus of elasticity is nearly 10 times smaller than in tension. This result is due to the different deformation patterns of the fibres in compression and tension.     

Shock wave pulse pressure after penetration of kidney tissue

Lithotripter generated compressional peak pressure (p⁺) was measured after penetrating tissue samples 0.5, 1, 2.5, and 4 cm thick. The samples were taken from fresh pig kidneys and insonated by shock wave pulses with positive peak pressures varying from 14 to 72 MPa. The measurement results allow one to draw some qualitative conclusions concerning the attenuation process in the lithotripter beam and show that in practice the compressional peak pressure values generated in the lithotripter may decrease almost by a factor of two before reaching the kidney stone. On the contrary, theoretical estimates indicate that negative pressures are practically not influenced by attenuation due to their different spectral composition     

The forward muon detector of the DELPHI experiment at LEP

The layout and construction of the muon drift chambers equipping the end caps of the DELPHI detector are described. The performance of this forward muon detection system, determined from cosmic ray tests and data collected during the first year of LEP operation, is presented.