On the influence of baseline startle reactivity on the indexation of prepulse inhibition.

Prepulse inhibition (PPI) of the startle reflex refers to the reduction of the reflexive startle response to an intense pulse stimulus when its presentation is shortly preceded by a weak prepulse stimulus. PPI is considered as a cross-species translational model of sensorimotor gating, and deficient PPI has been reported in a number of neuropsychiatric disorders. Although a part of the literature is based on the assumption that PPI is independent of the baseline startle reaction, there is accumulating evidence (Csomor et al., 2006; Sandner & Canal, 2007; Yee, Chang, Pietropaolo, & Feldon, 2005) that argues against such an independency. The authors systematically investigated whether PPI indexed as percentage or difference score is dependent on the magnitude of baseline startle reactivity in healthy human volunteers and in C57BL/6 mice. The results revealed that both indexations of PPI were affected by the magnitude of the baseline startle. The authors highlight the pitfalls of different methods to index PPI, especially when startle reactivity differs considerably between groups under comparison, and offer practical recommendations to satisfactorily deal with such baseline differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of polypyrrole modified electrode functionalization on potentiometric pH responses

Two functionalized polypyrrole films, poly(11-N-pyrrolylundecanoic) acid and poly(N-undecylpyrrole), were used as sensitive layers for pH sensors. The functionalized pyrrole monomers were first synthesized before carrying out their electropolymerization onto non-oxidizable electrodes. The deposits were characterized by SEM imaging, XPS and PM-IRRAS to study surface structure and composition. Poly(11-N-pyrrolylundecanoic) acid coating yielded very promising results as sensitive layer in pH sensors. Indeed, the potentiometric responses from pH 4.0 to 9.0 appeared linear, reversible, stable in time over a period of 1 month and highly selective for H⁺ ions. This behavior was attributed to carboxylic acid groups which are sensitive to proton concentration changes. This was confirmed by the fact that poly(N-undecylpyrrole) film led to potentiometric responses being pH dependent only from pH 6.0 to 9.0 with low sensitivity. Poly(11-N-pyrrolylundecanoic) acid is thus promoted to be used as sensitive layer in pH sensors.     

Understanding action beyond imitation: Reversed compatibility effects of action observation in imitation and joint action.

A robust finding in imitation literature is that people perform their actions more readily if they are congruent with the behavior of another person. These action congruency effects are typically explained by the idea that the observation of someone else acting automatically activates our motor system in a directly matching way. In the present study action congruency effects were investigated between an imitation task and a complementary action task. Subjects imitated or complemented a virtual actor's grasp on a manipulandum. In both tasks, a color-cue could be presented forcing subjects to ignore the task rule and execute a predefined grasp. Reaction times revealed a reversal of congruency effects in the complementary action task, suggesting that subjects were able to circumvent the automatic tendency to copy actions or postures of another person. In 2 additional control experiments, congruency effects were replicated, and a Simon effect was identified to underlie faster responses in the imitation task. These results make a case against current theoretical views on imitation and direct matching in favor of more flexible models of perception-action coupling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Software is different

The reliability notions that have worked so well for hardware do not work for software. It is not just reliability issues that makes software engineering different than most traditional engineering disciplines, but fundamental, usually unrecognized paradigms. Twelve assumptions that are rarely questioned in traditional engineering fields are explored and each is shown not to hold in software engineering. These differences between software engineering and traditional engineering are often at the core of misunderstandings between their practitioners. This revised version was published online in June 2006 with corrections to the Cover Date.     

Prospects for the use of high-Tc superconductors in fusion magnets and options for their test in SULTAN

In the last few years, the critical current densities of long commercially available REBa₂Cu₃O_7?x (RE-123, where RE represents Y or a rare earth element) coated conductors have reached values of 250 A/cm-width at 77 K and zero applied field. Even higher values of 600 A/cm-w (77 K, B = 0) have been demonstrated in shorter lengths. The attractive features of the use of these high-T_c superconductors (HTS) are operation temperatures above 20 K and/or magnetic fields higher than those envisaged for the ITER TF coils. Possible operation conditions for HTS fusion magnets have been studied taking into consideration the possible further improvements of RE-123 coated conductors. Investigations of stability and quench behavior indicate that stability is not a problem, whereas quench detection and protection need attention. Because of the high currents necessary for fusion magnets, many tapes need to be assembled into a transposed conductor. The qualification of HTS conductors for fusion magnets would require their test at magnetic fields of 11 T and currents well above 10 kA. The possibilities to test straight HTS conductor samples in SULTAN have been considered. For a test at 4.5 K, only the development of a low resistance joint between the HTS conductor under test and the NbTi transformer of SULTAN would be necessary. Tests up to 20 K would require that the HTS sample is connected with the NbTi transformer by a conduction-cooled HTS bus bar of large thermal resistance similar to the HTS module of a current lead. HTS conductor tests at temperatures around 50 K would be possible with modified cryogenics.     

Some Characteristics of Free Cell Population in the Airways of Rats after Intratracheal Instillation of Copper-Containing Nano-Scale Particles

We used stable water suspensions of copper oxide particles with mean diameter 20 nm and of particles containing copper oxide and element copper with mean diameter 340 nm to assess the pulmonary phagocytosis response of rats to a single intratracheal instillation of these suspensions using optical, transmission electron, and semi-contact atomic force microscopy and biochemical indices measured in the bronchoalveolar lavage fluid. Although both nano and submicron ultrafine particles were adversely bioactive, the former were found to be more toxic for lungs as compared with the latter while evoking more pronounced defense recruitment of alveolar macrophages and especially of neutrophil leukocytes and more active phagocytosis. Based on our results and literature data, we consider both copper solubilization and direct contact with cellular organelles (mainly, mitochondria) of persistent particles internalized by phagocytes as probable mechanisms of their cytotoxicity.     

Investigation of the rotary swaging and heat treatment on the behavior of W- and γ-phases in PM 92.5W–5Ni–2.5Fe–0.26Co heavy alloy

The effects of rotary swaging and different heat treatment procedures on the W- and γ-phases behavior of PM 92.5W–5Ni–2.5Fe (wt.%) heavy alloy microalloyed with cobalt have been studied. The investigation was performed on sintered and cold rotary swaged samples deformed with area reduction from 5 to 30%. One batch of swaged samples was annealed in vacuum at 1473 K for 7.2 ks and then furnace-cooled to the room temperature, whereas another batch of swaged samples was previously deformed 30% and strain aged in argon and nitrogen in the temperature range between 473 and 1123 K for 3.6 ks. Strengthening of W- and γ-phases was investigated by applying microhardness measurements. Effects of the degree of deformation, parameters of heat treatment and strain aging on microstructural changes have been studied. Mechanical properties, hardness and microhardness of phases as a function of the degree of deformation and heat treatment were analyzed by applying statistical modeling. A correlation between deformation behavior of phases, effect of heat treatment and alloy properties was also discussed.     

Particle Adhesion to Drops

The adhesion of spheroidal particles to spherical drops is calculated and discussed in terms of an equilibrium-penetration index. The present study emphasizes the case of particles that are sufficiently large to affect the drop volume upon penetration. It is shown that the more elongated the particles, the steeper the dependence of the penetration index on the contact angle. The effect of line tension on nanoscale particles is considered. Positive line tensions increase the steepness of the dependence of penetration index on contact angle whereas negative line tensions decrease this dependence. In addition, the energy barrier caused by positive line tensions is presented and discussed.     

On the spatial distribution of visual attention.

A reanalysis of part of P. Podgorny and R. N. Shepard's (see record 1984-03057-001) data shows that reaction times (RTs) to attended and unattended squares are almost identical when the attended areas are nonunitary and that RTs are related to compactness for unitary attended areas but that this relation breaks down when attention is focused on nonunitary areas. The importance of the actual grid location of probes on RTs is also illustrated. The failure of compactness to reflect these aspects of the spatial nature of attention suggests that this metric is deficient when applied to the study of the spatial determinants of attention. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)