Memorial University of Newfoundland

About: Memorial University of Newfoundland is a education organization based out in St. John's, Newfoundland and Labrador, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 13818 authors who have published 27785 publications receiving 743594 citations. The organization is also known as: Memorial University & Memorial University of Newfoundland and Labrador.

Lipid class compositions, tocopherols and sterols of tree nut oils extracted with different solvents

Abstract: The chemical compositions of tree nut oils were examined. The oils of almonds, Brazil nuts, hazelnuts, pecans, pine nuts, pistachios and walnuts were extracted using hexane and chloroform/methanol. The chloroform/methanol system afforded a higher oil yield for each tree nut type examined (pine nuts had the highest oil content while almonds had the lowest). The lipid class compositions of the tree nut oils were analyzed using the thin-layer chromatography-flame ionization detector and showed that triacylglycerols were the predominant lipid class present. Smaller amounts of sterols, sterol esters, phospholipids and sphingolipids were also present. The fatty acid compositions of the tree nut oils were analyzed using gas chromatography, showing that oleic acid was the predominant fatty acid in all samples except pine nut and walnut oils, which contained high amounts of linoleic acid. The sterol and stanol content and compositions were analyzed using gas chromatography; β-sitosterol was the predominant sterol present in all samples, with lower amounts of campesterol, stigmasterol, Δ5-avenasterol, 22-nordehydrocholesterol, 24-methylenecholesterol, cholesterol, cholestanol and β-sitostanol also present. The tocopherol compositions were analyzed using high-performance liquid chromatography, showing that α- and γ-tocopherols were the predominant tocopherol homologs present; however, δ- and β-tocopherols were also detected in some samples. PRACTICAL APPLICATIONS Tree nut oils contain health-promoting unsaturated fatty acids and minor components that may render beneficial effects. The lipid class compositions of the oils are reported as these affect the stability of the tested oils. Results may have significance in terms of practical applications for food and use in nutraceutical and/or cosmoceuticals products.

Self-diffusion and viscosity in electrolyte solutions.

Abstract: The effect of salt on the dynamics of water molecules follows the Hofmeister series. For some “structure-making” salts, the self-diffusion coefficient of the water molecules, D, decreases with increasing salt concentration. For other “structure-breaking” salts, D increases with increasing salt concentration. In this work, the concentration and temperature dependence of the self-diffusion of water in electrolyte solutions is studied using molecular dynamics simulations and pulsed-field-gradient NMR experiments; temperature-dependent viscosities are also independently measured. Simulations of rigid, nonpolarizable models at room temperature show that none of the many models tested can reproduce the experimentally observed trend for the concentration dependence of D; that is, the models predict that D decreases with increasing salt concentration for both structure-breaking and structure-making salts. Predictions of polarizable models are not in agreement with experiment either. These results suggest that man...

Five years later: children's memory for medical emergencies

Abstract: Children who had been 2–13 years of age at the time of a medical emergency (an injury serious enough to require hospital ER treatment) were re-interviewed about their injury and treatment five years after injury, and three years after a previous interview. The children showed excellent recall of the central components of their injury experience, although their recall of hospital treatment was more incomplete. Thus, both the nature of the event being recalled (the injury versus the hospital treatment) and the centrality of information (central versus peripheral) were important. The recall of 2-year-olds, although not as good as that of children just a year older, did not fit with predictions of infantile amnesia since they recalled a considerable amount about their injury. High stress levels at the time of the target experiences had little effect on the highly memorable injury event, but seemed to facilitate children's recall of central components of the hospital event—the event that they had a harder time remembering. Implications for eyewitness testimony are discussed. Copyright © 2001 John Wiley & Sons, Ltd.