Early attentional deficits in an attention-to-prepulse paradigm in ADHD adults.

Adults with attention-deficit/hyperactivity disorder (ADHD) were examined for early and late attentional processes as a function of controlled attention. The test paradigm was the attentional modulation of prepulse inhibition (PPI; early controlled attentional processing) and prepulse facilitation (PPF; late controlled attentional processing). In 49 patients and 49 controls, the authors measured acoustic startle responses to 96-dB startle pulses preceded 120, 240 (for PPI), 2,000, and 4,500 (for PPF) ms by a 68-dB prepulse noise. Geometric figures signaled that prepulses were to be ignored or attended to (automatic vs. controlled attention). ADHD patients exhibited deficits in prepulse modulation, but these reflected an interaction of controlled attention and time of information processing. Normal PPI and PPF occurred under all conditions except for controlled attentional modulation of PPI. Attention deficits in ADHD patients may reflect not general derangements in information processing or ability to attend but, rather, selective disturbances of controlled attention during early information processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transport Properties of Heavy Fermion Compounds: YbIn1−x Cu4+x and YbIn1−y Ag y Cu4

The intermetallic compounds of Yb with In and Cu (YbIn_1–x Cu_4+x ) and Yb with In, Ag, and Cu (YbIn_1–y Ag _y Cu₄) exhibit interesting magnetic and transport properties. Of the compounds of Yb with In and Cu the compound with x=0, namely YbInCu₄, has attracted particular attention, because—while being a Curie–Weiss paramagnet—it undergoes a first-order isostructural phase transition at T _v =approx. 40 to 80 K and atmospheric pressure. Below T _v the ytterbium in this compound is in a mixed-valence state and the compound as a whole is sometimes called a light heavy-fermion system. Above T _v , the compound is known as a Curie–Weiss paramagnet of localized magnetic moments and, below T _v , a Pauli paramagnet in a nonmagnetic Fermi-liquid state. In the present paper the results of measurements of the thermal conductivity of polycrystalline samples, YbIn_1–x Cu_4+x with x=0,0.015, 0.095, and 0.17 and YbIn_1–y Ag _y Cu₄ with y=0, 0.3, 0.7, and 1.0, are reported. The thermal conductivity is separated into the phonon thermal conductivity ( _ph ) (i.e., related to the heat carried by phonons) and into the electronic thermal conductivity ( _e ) (related to the heat carried by electrons). The electrical resistivity of the compounds was measured to determine the temperature dependence of the Lorenz number. The results show that in the temperature interval 4.2 to 300 K the latter quantity behavior follows the theoretical predictions for heavy fermion materials.     

Fast Dynamic Transitive Closure with Lookahead

In this paper we consider the problem of dynamic transitive closure with lookahead. We present a randomized one-sided error algorithm with updates and queries in O(n ^{ω(1,1,ε)−ε} ) time given a lookahead of n ^ε operations, where ω(1,1,ε) is the exponent of multiplication of n×n matrix by n×n ^ε matrix. For ε≤0.294 we obtain an algorithm with queries and updates in O(n ^2−ε ) time, whereas for ε=1 the time is O(n ^ω−1). This is essentially optimal as it implies an O(n ^ω ) algorithm for boolean matrix multiplication. We also consider the offline transitive closure in planar graphs. For this problem, we show an algorithm that requires O(n^\fracw2)O(n^{\frac{\omega}{2}}) time to process n^\frac12n^{\frac{1}{2}} operations. We also show a modification of these algorithms that gives faster amortized queries. Finally, we give faster algorithms for restricted type of updates, so called element updates. All of the presented algorithms are randomized with one-sided error. All our algorithms are based on dynamic algorithms with lookahead for matrix inverse, which are of independent interest.     

Virtual Rheoscopic Fluids

We present a visualization technique for simulated fluid dynamics data that visualizes the gradient of the velocity field in an intuitive way. Our work is inspired by rheoscopic particles, which are small, flat particles that, when suspended in fluid, align themselves with the shear of the flow. We adopt the physical principles of real rheoscopic particles and apply them, in model form, to 3D velocity fields. By simulating the behavior and reflectance of these particles, we are able to render 3D simulations in a way that gives insight into the dynamics of the system. The results can be rendered in real time, allowing the user to inspect the simulation from all perspectives. We achieve this by a combination of precomputations and fast ray tracing on the GPU. We demonstrate our method on several different simulations, showing their complex dynamics in the process.     

Solid–liquid equilibria in the quasi-binary thallium(I) telluride–indium(III) telluride system

The quasi-binary Tl₂Te–In₂Te₃ phase diagram has been constructed based on the results of studies by both thermal analysis and X-ray diffraction. Our earlier data obtained through electrochemical investigation of this system were of aid for the final establishment of the phase diagram. Numerical values of the phase transition temperatures at different alloy compositions have been presented in a table. The diagram has been compared with that published earlier by other authors. The study has produced substantial evidence corroborating the formation of two new chemical compounds that have not been found earlier.     

Effect of Synthesis Process and Substrate on Electrical and Thermal Transport Properties of Bi-2212

Resistivity, thermoelectric power, and thermal conductivity have been measured for a Bi-2212 system synthesized from a glassy precursor, either with a commercially Al₂O₃ substrate or with a homemade BaZrO₃ substrate. Those measurements show that the BaZrO₃ substrate gives better superconducting properties to the Bi-2212 than the Al₂O₃ substrate. The effect of (1.0 T) weak magnetic field has been searched for. The thermal magnetoconductivity and the contributions of the magnetic field to the thermoelectrical power are studied and compared through fine measurements. An electronic contribution seems to appear already well above the critical temperature and to exist up to 200°K. The onset temperature is thus deduced.     

Study of motional processes in polymer blends composed of isotactic polypropylene and ethylene–propylene–diene monomer rubber by broad‐line 1H‐NMR

The broad‐line ¹H‐NMR study of the polymer blend composed of isotactic polypropylene and ethylene–propylene–diene monomer rubber was carried out. The NMR measurements were performed on the samples of the polymer blend and on the components of the blend in the temperature range covering the glass‐transition regions of all studied polymers. Conclusions were drawn from the temperature dependencies of the second moment M₂ and of the data obtained by the decomposition of the spectra into the components related to the motionally distinct regions of the partially crystalline polymer. The mass fractions of the amorphous, intermediate, and crystalline domains and the widths of the spectra related to the particular phases were computed from the spectra. A double glass transition was revealed for the polymer blend. Different mechanisms of the motional processes related to the glass transition were deduced from the data. The gradual increase of the number of the chains and the enhancement of the chain mobility within noncrystalline regions of the polymer blend are responsible for the motion related to the lower glass transition and only transformation of the hindered motion into free motion was found in the temperature region of the upper glass transition. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 247–252, 2004     

Paradoxic response of the murmur of idiopathic hypertrophic subaortic stenosis to the Valsalva maneuver

A case of documented severe idiopathic hypertrophic subaortic stenosis in which the Valsalva maneuver resulted in paradoxic attenuation of the systolic ejection murmur is presented. Such a response should not be considered incompatible with the diagnosis of this disease.