Spatial-sequential working memory in younger and older adults : age predicts backward recall performance within both age groups

Working memory is vulnerable to age-related decline, but there is debate regarding the age-sensitivity of different forms of spatial-sequential working memory task, depending on their passive or active nature. The functional architecture of spatial working memory was therefore explored in younger (18-40 years) and older (64-85 years) adults, using passive and active recall tasks. Spatial working memory was assessed using a modified version of the Spatial Span subtest of the Wechsler Memory Scale – Third Edition (WMS-III; Wechsler, 1998). Across both age groups, the effects of interference (control, visual, or spatial), and recall type (forward and backward), were investigated. There was a clear effect of age group, with younger adults demonstrating a larger spatial working memory capacity than the older adults overall. There was also a specific effect of interference, with the spatial interference task (spatial tapping) reliably reducing performance relative to both the control and visual interference (dynamic visual noise) conditions in both age groups and both recall types. This suggests that younger and older adults have similar dependence upon active spatial rehearsal, and that both forward and backward recall require this processing capacity. Linear regression analyses were then carried out within each age group, to assess the predictors of performance in each recall format (forward and backward). Specifically the backward recall task was significantly predicted by age, within both the younger and older adult groups. This finding supports previous literature showing lifespan linear declines in spatial-sequential working memory, and in working memory tasks from other domains, but contrasts with previous evidence that backward spatial span is no more sensitive to aging than forward span. The study suggests that backward spatial span is indeed more processing-intensive than forward span, even when both tasks include a retention period, and that age predicts backward spatial span performance across the adult lifespan, within both younger and older adulthoo

Multimodal coding and strategic approach in young and older adults' visual working memory performance

Visual working memory (WM) was investigated in young (18–35 yrs) and older (63–88 yrs) adults by assessing use of visual and verbal processing, and strategic approach. Experiment 1 comprised a visual interference paradigm, to investigate visual rehearsal during an abstract visual WM task. Results suggested both groups used a visual strategy, but older adults struggled more when visual interference was administered first, perhaps due to difficulty developing non-visual strategies. In Experiment 2, a more meaningful task version was additionally administered, offering greater opportunity for multimodal coding. Despite the marked effect of age, both groups benefited from semantic availability to the same extent. Young adults reported a verbal strategy more than older adults, who reported less verbal labeling and more visual refreshing, and a less efficient approach overall. The results highlight age-related limitations in visual WM capacity and strategy use, but show potential for compensation, and a role for task practice

3D Monte Carlo radiation transfer modelling of photodynamic therapy

We acknowledge the support of the UK Engineering and Physics Sciences Research Council (EPSRC) for funding through a studentship for C L Campbell as well as the Alfred Stewart Trust.The effects of ageing and skin type on Photodynamic Therapy (PDT) for different treatment methods have been theoretically investigated. A multilayered Monte Carlo Radiation Transfer model is presented where both daylight activated PDT and conventional PDT are compared. It was found that light penetrates deeper through older skin with a lighter complexion, which translates into a deeper effective treatment depth. The effect of ageing was found to be larger for darker skin types. The investigation further strengthens the usage of daylight as a potential light source for PDT where effective treatment depths of about 2 mm can be achieved.Publisher PD

Inter-rater reliability of treatment fidelity and therapeutic alliance measures for psychological therapies for anxiety in young people with autism spectrum disorders

Objectives: This article presents work undertaken to establish inter-rater reliability for a measure of treatment fidelity and a measure of therapeutic alliance for therapies for anxiety for young people with autism spectrum disorders. The discussion and decision-making processes behind achieving consensus of raters are rarely published. Margolin et al. (1998) have highlighted this issue and called for researchers to communicate the details of their observational and rating procedures. This article is a response to their call for greater transparency so that these methods are readily accessible for comparison with other studies. Methods: Participants were young people with autism spectrum disorders receiving treatment for anxiety, clinical staff treating these young people and the independent raters assessing the treatment sessions. We report: (i) the processes involved in establishing inter-rater reliability for two instruments, (ii) the results obtained with a sample of young people with autism spectrum disorders using these instruments. Results and conclusions: Results demonstrate that it was possible to attain satisfactory inter-rater reliability with each of these two instruments with a client group with autism spectrum disorders, even though the instruments were originally designed for typically-developing populations

Inter-rater reliability of treatment fidelity and therapeutic alliance measures for psychological therapies for anxiety in young people with autism spectrum disorders

Objectives: This article presents work undertaken to establish inter-rater reliability for a measure of treatment fidelity and a measure of therapeutic alliance for therapies for anxiety for young people with autism spectrum disorders. The discussion and decision-making processes behind achieving consensus of raters are rarely published. Margolin et al. (1998) have highlighted this issue and called for researchers to communicate the details of their observational and rating procedures. This article is a response to their call for greater transparency so that these methods are readily accessible for comparison with other studies. Methods: Participants were young people with autism spectrum disorders receiving treatment for anxiety, clinical staff treating these young people and the independent raters assessing the treatment sessions. We report: (i) the processes involved in establishing inter-rater reliability for two instruments, (ii) the results obtained with a sample of young people with autism spectrum disorders using these instruments. Results and conclusions: Results demonstrate that it was possible to attain satisfactory inter-rater reliability with each of these two instruments with a client group with autism spectrum disorders, even though the instruments were originally designed for typically-developing populations

Age-related mitochondrial DNA depletion and the impact on pancreatic beta cell function

Type 2 diabetes is characterised by an age-related decline in insulin secretion. We previously identified a 50% age-related decline in mitochondrial DNA (mtDNA) copy number in isolated human islets. The purpose of this study was to mimic this degree of mtDNA depletion in MIN6 cells to determine whether there is a direct impact on insulin secretion. Transcriptional silencing of mitochondrial transcription factor A, TFAM, decreased mtDNA levels by 40% in MIN6 cells. This level of mtDNA depletion significantly decreased mtDNA gene transcription and translation, resulting in reduced mitochondrial respiratory capacity and ATP production. Glucose-stimulated insulin secretion was impaired following partial mtDNA depletion, but was normalised following treatment with glibenclamide. This confirms that the deficit in the insulin secretory pathway precedes K+ channel closure, indicating that the impact of mtDNA depletion is at the level of mitochondrial respiration. In conclusion, partial mtDNA depletion to a degree comparable to that seen in aged human islets impaired mitochondrial function and directly decreased insulin secretion. Using our model of partial mtDNA depletion following targeted gene silencing of TFAM, we have managed to mimic the degree of mtDNA depletion observed in aged human islets, and have shown how this correlates with impaired insulin secretion. We therefore predict that the age-related mtDNA depletion in human islets is not simply a biomarker of the aging process, but will contribute to the age-related risk of type 2 diabetes

Candida albicans Hypha Formation and Mannan Masking of β-Glucan Inhibit Macrophage Phagosome Maturation

Received 28 August 2014 Accepted 28 October 2014 Published 2 December 2014 This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported license. ACKNOWLEDGMENTS We thank Janet Willment, Aberdeen Fungal Group, University of Aberdeen, for kindly providing the soluble Dectin-1-Fc reporter. All microscopy was performed with the assistance of the University of Aberdeen Core Microscopy & Histology Facility, and we thank the IFCC for their assistance with flow cytometry. We thank the Wellcome Trust for funding (080088, 086827, 075470, 099215, 097377, and 101873). E.R.B. and A.J.P.B. are funded by the European Research Council (ERC-2009-AdG-249793), and J.L. is funded by a Medical Research Council Clinical Training Fellowship.Peer reviewedPublisher PD