Waterfowl Harvest by Slave Indians in Northern Alberta

The consumption of waterfowl by a small band of Slave Indians was monitored from May to September of 1966 and 1967 at Habay in northern Alberta. The Indians killed waterfowl by two main methods: with shotguns when birds were on the wing, and with clubs when flightless. In 1966 this food formed the major source of protein for the Indians over the spring-to-fall period; in August they consumed an average of 0.6 of a pound of flesh per day per person. In 1967 the amount fell to about one-quarter of this amount when the band relied more heavily on an alternative food source. The responses shown by Indian hunters to changing waterfowl densities are compared with those shown by predators to changing prey densities

Four lectures on secant varieties

This paper is based on the first author's lectures at the 2012 University of Regina Workshop "Connections Between Algebra and Geometry". Its aim is to provide an introduction to the theory of higher secant varieties and their applications. Several references and solved exercises are also included.Comment: Lectures notes to appear in PROMS (Springer Proceedings in Mathematics & Statistics), Springer/Birkhause

Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume

The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-β PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-β positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimer’s disease-related phenotypes, including measures of cognition or brain Amyloid-β burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes

Quartz veins record vertical flow at a Graben Edge; Fulmar oil field, central North Sea

The Fulmar oil field lies at the faulted western margin of the Central Graben in the central North Sea. Chalcedony and quartz, and later dolomite, occur as diagenetic cements in veins within the Upper Jurassic Fulmar Formation. Quartz in one particular vein contains primary aqueous fluid inclusions with homogenization temperatures ranging from 85 degrees to 140 degrees C, with a mean of 117 degrees C. The measured d18O of the authigenic quartz ranges from +25.1 to +27.1o/oo SMOW. The d18O of the water from which most of the quartz precipitated is calculated to have been around +8o/oo, which is significantly more positive than the measured present-day formation water d18O of +4o/oo. Quartz and chalcedony cements in the vein are postdated texturally by dolomite that has a d18O of +23.5o/oo SMOW. High salinities are recorded in the fluid inclusions in the quartz, the majority ranging from 15 to 19 wt. % NaCl equivalent. Also, the quartz contains inclusions of anhydrite. High-salinity aqueous inclusions, combined with anhydrite inclusions in the quartz and the 18O-enriched calculated water composition, suggest that the quartz precipitated from an evaporite-influenced fluid. The same fluid contributed Mg for dolomite precipitation. More deeply buried sections, including the Permian Zechstein evaporites underlying the Fulmar field, are the most obvious source of an 18O-enriched saline fluid. Mineralization of the vein resulted from cross-formational flow of warm fluids from depth through the Zechstein and into the Jurassic succession over vertical distances of 600-2000 m. Fluids most probably migrated up faults and fractures during episodes of salt movement or overpressure release

ICU-Talk, a communication aid for intubated intensive care patients

A Multi-disciplinary project staffed by personnel from nursing, computer science and speech and language therapy developed a computer based communication aid called ICU-Talk. This device has been designed specifically for intubated patients in hospital intensive care units. The ICU-Talk device was trialled with real patients. This paper reports the challenges faced when developing a device for this patient group and environment. A description of the methods used to produce ICU-Talk and resul ~ from the trials will be presented