Intraindividual variability is related to cognitive change in older adults: Evidence for within-person coupling.

In this study, the authors addressed the longitudinal nature of intraindividual variability over 3 years. A sample of 304 community-dwelling older adults, initially between the ages of 64 and 92 years, completed 4 waves of annual testing on a battery of accuracy- and latency-based tests covering a wide range of cognitive complexity. Increases in response-time inconsistency on moderately and highly complex tasks were associated with increasing age, but there were significant individual differences in change across the entire sample. The time-varying covariation between cognition and inconsistency was significant across the 1-year intervals and remained stable across both time and age. On occasions when intraindividual variability was high, participants' cognitive performance was correspondingly low. The strength of the coupling relationship was greater for more fluid cognitive domains such as memory, reasoning, and processing speed than for more crystallized domains such as verbal ability. Variability based on moderately and highly complex tasks provided the strongest prediction. These results suggest that intraindividual variability is highly sensitive to even subtle changes in cognitive ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of interspersed repetitive sequence polymerase chain reaction for construction of yeast artificial chromosome contigs

This work is devoted to the comprehension of the sorption mechanism of uranyl ions on chitosan particle dispersions. The uranyl concentration measurements were obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) and we considered the role of various physicochemical parameters (pH; nature and concentration of added salts; degree of acetylation, DA). The use of appropriate calculation software allowed us to determine the chemical nature of uranyl species in solution in relation to these different parameters. The optimal pH of fixation has been found to be within 6.5-7.5 and can be related to the necessity of having both deprotonated amino groups and no carbonate ions, which are a strong complexant of uranyl ions, thus inhibiting their interaction with chitosan. The decrease of metal uptake with an increase of DA and the lack of influence of ionic strength, confirm the results obtained with pH and allowed us to suppose the formation of a complex with chitosan amino groups rather than interactions of an electrostatic nature.     

George A. Miller, language, and the computer metaphor and mind.

This article asks why the analogy between humans and computers was understood by cognitive psychologists to mean that "minds exist and that it is our job as psychologists to study them." Earlier psychologists, such as Clark Hull, used analogies between humans and complex machines such as telephone switchboards to defend a rigorous behaviorism. How, then, did the computer metaphor of mind come to be seen as the root concept underlying a paradigm shift from behaviorism to cognitivism? To answer this question, this article examines the life and work of George A. Miller, one of the most prominent of a generation of psychologists who began their careers as "good behaviorists" but later came to embrace cognitivism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A statnet Tutorial

The statnet suite of R packages contains a wide range of functionality for the statistical analysis of social networks, including the implementation of exponential-family random graph (ERG) models. In this paper we illustrate some of the functionality of statnet through a tutorial analysis of a friendship network of 1,461 adolescents.     

An improved closed-form approximation to the inverse black body radiation problem at microwave frequencies

A function is derived which approximates Planck's black body radiation law more closely at microwave frequencies than either the Rayleigh-Jeans or the recent Hamid-Ragheb approximations. The function leads to an improved closed-form approximation to the inverse black body radiation problem in the microwave region.     

Oxygen Position and Bond Lengths from Lattice Parameters in Tetragonal Zirconias

A survey of the available data on the oxygen positions in various tetragonal zirconias reveals a simple, approximate relationship between the departure of the oxygen from the position it would have in the ideal fluorite structure, and the tetragonality ( c/a ) of the material. This relationship can be understood on the basis that the two oxygen—oxygen contact distances are very nearly equal. The relationship may be used to estimate the oxygen position from the lattice parameters, and from that all the bond lengths in the structure.     

Introduction to special issue: The plus ultra of empirical research.

Recent advances in cognitive science and neuroscience (CSN) have allowed scientists to begin to address questions that were heretofore considered the province of the humanities. Growing out of a 2007 conference at Bucknell University, this volume explores recent research in many different areas that combines the methods and perspectives of both the humanities and CSN. This introduction argues that the barriers to such work (such as the opposition between objective scientific research and subjective humanistic research) are purely of our own making and in no way absolute; it further asserts that the articles herein demonstrate that the potential benefits of interdisciplinary study far outweigh the risks. There is no fixed method for interdisciplinarity. Its success depends on respect for the particulars of each research question and the imagination to see what combinations of different disciplines might work best. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tunable microwave photonic passive delay line based on multichannel fibre grating matrix

A discretely tunable passive microwave photonic delay line based on a multichannel grating matrix is demonstrated. This topology demonstrates high-speed high-resolution time delaying of microwave signals, along with requiring a reduced number of discrete gratings for any given delay range. High channel isolation and low insertion loss are also features of this topology, making this suitable for many wideband applications.     

Localization and speciation of chromium in subterranean clover using XRF, XANES, and EPR spectroscopy

Optimization of phytoremediation and assessment of potential health hazards from metals in the environment requires an understanding of absorption, localization, and transport of the target metal by plants. The objectives of this study were to localize Cr and determine the oxidation state and possible complexation mode of Cr in intact plant tissue by means of XANES, synchrotron XRF microprobe spectroscopy, and EPR spectroscopy. Subterranean clover (Trifolium brachycalycinum) was grown hydroponically with Cr(VI) (0.04-2.0 mmol L(-1)) and compared with plants grown without Cr and with inorganic Cr(III) and various Cr(III)-organic sources. The uptake, translocation, and form of Cr in the plant were dependent on the form and concentration of supplied Cr. Chromium was found predominately in the +3 oxidation state, regardless of the Cr source supplied to the plant, though at high Cr(VI) treatment concentrations, Cr(VI) and Cr(V) were also observed. At low Cr(VI) concentrations, the plant effectively reduced the toxic Cr(VI) to less toxic Cr(III), which was observed both as a Cr(III) hydroxide phase at the roots and as a Cr(III)-organic complex in the roots and shoots. At low Cr(VI) treatment concentrations, Cr in the leaves was observed predominately around the leaf margins, while at higher concentrations Cr was accumulated at leaf veins.