Dipolar pathways in multi-spin and multi-dimensional dipolar EPR spectroscopy.

Dipolar electron paramagnetic resonance (EPR) experiments, such as double electron-electron resonance (DEER), measure distributions of nanometer-scale distances between unpaired electrons, which provide valuable information for structural characterization of proteins and other macromolecular systems. We present an extension to our previously published general model based on dipolar pathways valid for multi-dimensional dipolar EPR experiments with more than two spin-1/2 labels. We examine the 4-pulse DEER and TRIER experiments in terms of dipolar pathways and show experimental results confirming the theoretical predictions.

Computing distance distributions from dipolar evolution data with overtones: RIDME spectroscopy with Gd(iii)-based spin labels.

Extraction of distance distributions between high-spin paramagnetic centers from relaxation induced dipolar modulation enhancement (RIDME) data is affected by the presence of overtones of dipolar frequencies. As previously proposed, we account for these overtones by using a modified kernel function in Tikhonov regularization analysis. This paper analyzes the performance of such an approach on a series of model compounds with the Gd(iii)-PyMTA complex serving as paramagnetic high-spin label.

Quantification and compensation of the influence of pulse transients on symmetry-based recoupling sequences.

Deviations of amplitude and phase of radio-frequency pulses from the desired values, can have a severe impact on the performance of multiple-pulse sequences in NMR spectroscopy. A particular problem are pulse transients that appear every time there is a discontinuity in amplitude or phase. Based on a Floquet description using pulses with arbitrarily shaped amplitudes and phases we present a systematic study of the influence of pulse transients on symmetry-based pulse sequences in solid-state NMR under magic-angle spinning.

PDA and smartphone use by individuals with moderate-to-severe memory impairment: application of a theory-driven training programme.

We describe a structured, theory-driven training programme for individuals with moderate-to-severe memory impairment in the use of emerging commercial technology. We demonstrate its application to 10 individuals with memory impairment from a variety of aetiologies. A within-subject, ABAB multi-case experimental design was used to evaluate the impact of personal digital assistant or smartphone use on day-to-day memory functioning at baseline, immediately post-intervention, at return to baseline, and at short-term follow-up (range = 3-8 months).

Exploratory factor analysis of neuropsychological tests and their relationship to the Brown-Peterson task.

The interference condition of the Brown-Peterson task and the auditory consonant trigrams test was designed to evaluate working memory in that it required a division of attentional processes to complete two cognitive tasks. However, the specific cognitive functions contributing to the performance of this interference task have yet to be determined. The objective of this study was to determine what other tasks are comparable to the Brown-Peterson task and conduct an exploratory factor analysis that included the measures from the Brown-Peterson task and other neuropsychological measures.

Explicit and objective scoring criteria for the taylor complex figure test.

The Rey and Taylor figures are two constructional and visual memory tests used interchangeably. The purpose of this study was to develop a scoring system for the Taylor figure based on the explicit guidelines established by Meyers and Meyers (1995) for the Rey figure. Younger (n = 97; mean age = 21 years) and older (n = 61; mean age = 72 years) participants' performance on the Taylor figure was scored according to the proposed scoring system and the original scoring system devised by Taylor (1989).

Comparing the Rey and Taylor complex figures: a test-retest study in young and older adults.

The Rey and Taylor figures, two visual perception and memory tests, are not equivalent in terms of their difficulty. The purpose of this study was to examine factors such as age, gender, order of administration, copy time, and copy score that could account for the variability in recall performance. Copy score was shown to be the best overall predictor of recall.