Abstracts from the NIHR INVOLVE Conference 2017

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STRATIGRAPHIC ANALYSIS OF LATE WISCONSIN AND HOLOCENE GLACIOLACUSTRINE DEPOSITS EXPOSED ALONG THE NOTTAWASAGA RIVER, SOUTHERN ONTARIO, CANADA

Analysis of 56 outcrop exposures in cut banks along the Nottawasaga River in southern Simcoe County, Ontario, Canada, has led to the identification of eight stratigraphic units (SU1-8) that represent a record of changing environmental conditions during deglaciation and exhibit strong controls on shallow groundwater flow in the region. The stratigraphic succession is floored by the Late Wisconsin Newmarket Till (SU1) which is locally overlain by ice-proximal debris flow deposits (SU2). These glacial sediments are overlain by glaciolacustrine silt rhythmites (SU3) that pass upwards into deltaic sand (SU4) and channelized fluviodeltaic sand and gravel (SU5). Lying above the fluvial deposits are widespread interbedded glaciolacustrine sands and silt (SU6), which coarsen up-section toward the ground surface. The succession is locally capped by fluviodeltaic (SU7) and younger fluvial (SU8) deposits. These stratigraphic units record sedimentary environments that existed during deglaciation of the region and provide insight into the evolution of glacial lakes Schomberg and Algonquin, and the Nipissing phase of the upper Great Lakes. The environmental changes described from sediments along the Nottawasaga River provide insights into basin-scale events that occurred throughout the upper Great Lakes during deglaciation. Qualitative observations of groundwater discharge from sediments at outcrop faces are used to characterize the hydraulic function of the stratigraphic units as well as possible preferential groundwater flow pathways in the shallow subsurface.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Clinical evaluation of cochlear implant sound coding taking into account conjectural masking functions, MP3000™

Efficacy of the SPEAK and ACE coding strategies was compared with that of a new strategy, MP3000™, by 37 European implant centers including 221 subjects. The SPEAK and ACE strategies are based on selection of 8-10 spectral components with the highest levels, while MP3000 is based on the selection of only 4-6 components, with the highest levels relative to an estimate of the spread of masking. The pulse rate per component was fixed. No significant difference was found for the speech scores and for coding preference between the SPEAK/ACE and MP3000 strategies. Battery life was 24% longer for the MP3000 strategy. With MP3000 the best results were found for a selection of six components. In addition, the best results were found for a masking function with a low-frequency slope of 50 dB/Bark and a high-frequency slope of 37 dB/Bark (50/37) as compared to the other combinations examined of 40/30 and 20/15 dB/Bark. The best results found for the steepest slopes do not seem to agree with current estimates of the spread of masking in electrical stimulation. Future research might reveal if performance with respect to SPEAK/ACE can be enhanced by increasing the number of channels in MP3000 beyond 4-6 and it should shed more light on the optimum steepness of the slopes of the masking functions applied in MP3000

Vitamin D, Cognitive Dysfunction and Dementia in Older Adults

The physiologically active form of vitamin D, 1,25-dihydroxyvitamin D3, is a fat-soluble steroid hormone with a well established role in skeletal health. A growing body of evidence suggests that low vitamin D levels also play a role in the pathogenesis of a wide range of non-skeletal age-associated diseases such as cancer, heart disease, type 2 diabetes and stroke. Low serum 25-hydroxyvitamin D (25(OH)D) levels, a stable marker of vitamin D status, are also associated with increased odds of prevalent cognitive dysfunction, Alzheimer’s and all-cause dementia in a number of studies, raising the possibility that vitamin D plays a role in the aetiology of cognitive dysfunction and dementia. So far the majority of human studies reporting associations between vitamin D and cognition or dementia have been cross-sectional or case-control designs that are unable to exclude the possibility that such associations are a result of disease progression rather than being causal. Animal and in-vitro experiments have identified a number of neuroprotective mechanisms that might link vitamin D status to cognitive dysfunction and dementia including vasoprotection and amyloid phagocytosis and clearance, but the clinical relevance of these mechanisms in humans is not currently clear. Two recent large prospective studies go some way to establish the temporal relationship with cognitive decline. The relative risk of cognitive decline was 60% higher (relative risk 1.60, 95% CI 1.2-2.0) in elderly Italian adults who are severely deficient (<25 nmol/L) when compared them with those sufficient (>75 nmol/L). Similarly the odds of cognitive decline were 41% higher (odds ratio 1.41, 95% CI 0.9-2.2) when elderly US men in the lowest quartile (<50 nmol/L) were compared with those in the highest quartile (>74 nmol/L). To our knowledge no prospective studies have examined the association between 25(OH)D levels and incident dementia or neuroimaging abnormalities. The possible therapeutic benefits of vitamin D have attracted considerable interest as over 1 billion people worldwide are thought to have insufficient 25(OH)D levels, which can be increased using inexpensive well-tolerated dietary supplements. However, no large randomized controlled trials have yet examined the effect of vitamin D supplements upon cognitive decline or incident dementia. Further studies are urgently needed to establish which mechanisms may have clinical relevance in human populations and whether vitamin D supplements are effective at minimizing cognitive decline or preventing dementia