Response activation in overlapping tasks and the response-selection bottleneck.

The authors investigated the impact of response activation on dual-task performance by presenting a subliminal prime before the stimulus in Task 2 (S2) of a psychological refractory period (PRP) task. Congruence between prime and S2 modulated the reaction times in Task 2 at short stimulus onset asynchrony despite a PRP effect. This Task 2 congruence effect was paralleled by a Task 1 congruence effect and emerged exclusively under conditions of cross talk, whereas it did not occur under dual-task conditions preventing cross talk between tasks. This suggests that response activation operates during the PRP in dual tasks and affects the response times in Task 2 via cross talk between common processing elements at prebottleneck stages but not by directly affecting the postbottleneck stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Methylphenidate and baseball playing in ADHD children: Who's on first?

The effects of 0.3 and 0.6 mg/kg methylphenidate were analyzed in a double-blind, placebo-controlled, cross-over study in which 17 boys (ages 7.8–9.9 yrs) with attention deficit hyperactivity disorder (ADHD) played in baseball games. Drug effects were evaluated on children's attention during the game, as indictated by their on-task behavior on the field and their ability to answer questions about the status of the game at all times. Judgment during batting, batting skill during the game, and performance on skill drills prior to the game were also assessed as a function of medication. Results revealed that methylphenidate had a beneficial effect on attending during the game. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Über die Variationsrechnung in Hilberts Werken zur Analysis

The paper deals with some of the developments in analysis against the background of Hilbert's contributions to the Calculus of Variations. As a starting point the transformation is chosen that took place at the end of the 19th century in the Calculus of Variations, and emphasis is placed on the influence of Dirichlet's principle. The proof of the principle (the “resuscitation”) led Hilbert to questions arising in the 19th and 20th problems of his famous Paris address in 1900: theexistence in a generalized sense, and theregularity of solutions of elliptic partial differential equations. By this new concept Hilbert pointed out two very important issues the history of which is closely tied up with the rise of modern analysis. Further on, Hilbert'stheorem of independence of the Calculus of Variations, an important contribution to its formal apparatus as well as to its field theory, is briefly discussed. But even as Hilbert published his first essential results, he was turning his attention to another area of mathematics that differs in an important respect from the Calculus of Variations:integral equations. Hilbert did so because he recognized that in this branch by its flexibility he was coming closer to his goal of an unifying methodological approach to analysis.     

Reflections on “what about people in regional science?”

The paper is the text of a speech delivered to the opening session of the Twenty-Eighth European Congress of the Regional Science Association in Stockholm in August 1988. It reflects on an earlier address (Hägerstrand 1970) in the light of numerous comments and criticisms made during the interim period.     

Der Stand der Ausbildung von Studierenden im Umgang mit Sterbenden und dem Tod an medizinischen Fakultäten in Deutschland: eine explorative Studie von 1994/95

Ohne Zusammenfassung     

Domain Switching During Electromechanical Poling in Lead Zirconate Titanate Ceramics

In many polycrystalline piezoelectric ceramics, domain switching during the poling process leads to the development of a macroscopic polarization and piezoelectric behavior. Traditionally, poling involves the application of electric fields across two parallel electrodes. In the present work, a radial mechanical compressive stress is applied transverse to the electric field, increasing the potential for domain alignment during poling by taking advantage of ferroelasticity. Experiments demonstrate that poling of lead zirconate titanate using a combination of an electric field and a transverse mechanical compressive stress increases the d ₃₃ coefficient from 435 to 489 pC/N. Using neutron diffraction and pole figure inversion methods, the degree of non-180° domain switching is described using pole density distributions of the tetragonal c -axis (002). The degree of 002 domain alignment parallel to the electric field after the electromechanical poling process increases from 1.30 multiples of a random distribution (mrd) to >1.40 mrd at stresses exceeding 40 MPa.     

Novel Furin Inhibitors with Potent Anti‐infectious Activity

New peptidomimetic furin inhibitors with unnatural amino acid residues in the P3 position were synthesized. The most potent compound 4‐guanidinomethyl‐phenylacteyl‐Arg‐Tle‐Arg‐4‐amidinobenzylamide (MI‐1148) inhibits furin with a K_i value of 5.5 pM . The derivatives also strongly inhibit PC1/3, whereas PC2 is less affected. Selected inhibitors were tested in cell culture for antibacterial and antiviral activity against infectious agents known to be dependent on furin activity. A significant protective effect against anthrax and diphtheria toxin was observed in the presence of the furin inhibitors. Furthermore, the spread of the highly pathogenic H5N1 and H7N1 avian influenza viruses and propagation of canine distemper virus was strongly inhibited. Inhibitor MI‐1148 was crystallized in complex with human furin. Its N‐terminal guanidinomethyl group in the para position of the P5 phenyl ring occupies the same position as that found previously for a structurally related inhibitor containing this substitution in the meta position, thereby maintaining all of the important P5 interactions. Our results confirm that the inhibition of furin is a promising strategy for a short‐term treatment of acute infectious diseases.     

A Review on Metal‐Free Doped Carbon Materials Used as Oxygen Reduction Catalysts in Solid Electrolyte Proton Exchange Fuel Cells

Within the last decade, metal‐free heteroatom doped carbon nanomaterials have gained attention as effective electrocatalysts for the oxygen reduction reaction (ORR) in many electrochemical systems. Since then, reports have stated that the ORR catalytic activity, onset potential, and H₂O production selectivity of these materials is similar to that of platinum‐based catalysts. These statements rely on cyclic voltammetry (CV) and rotating disc electrode (RDE) measurements in liquid alkaline electrolyte. However, fuel cell researchers aim to replace the costly platinum catalysts in the more prominent acidic solid electrolyte proton exchange fuel cell (PEFC). In this respect, there are only a few reports of unpromising activity, stability, and H₂O production selectivity. In addition, only few reports have been presented on the implementation of such materials in cathode catalyst layers of actual PEFC devices. This mini‐review aims to summarize and evaluate results of these reports. Material synthesis, cell power, open circuit voltage, stability properties, and proposed active sites are reviewed. To date, the highest reported PEFC power densities with guaranteed metal‐free heteroatom doped carbon cathode catalysts have reached up to 321 mW cm⁻²; which although a promising value is substantially short of values obtained for platinum based catalysts.