University of Guelph

About: University of Guelph is a education organization based out in Guelph, Ontario, Canada. It is known for research contribution in the topics: Population & Gene. The organization has 26542 authors who have published 50553 publications receiving 1715255 citations. The organization is also known as: U of G & Guelph University.

Resolving crystallographically distinct tetrahedral sites in silicalite and ZSM-5 by solid-state NMR

Abstract: ‘Magic-angle-spinning’ NMR has revealed fresh insights into the atomic structure of the polymorph of silica, silicalite, which has exceptional absorptive properties. There is evidence that highly crystalline variants of silicalite contain 24 distinct tetrahedral locations, populated principally by Si4+ ions, and that, contrary to what was originally thought, aluminium is also present, in at least two kinds of environments, in the tetrahedral framework. The silicalite structure is shown to be essentially indistinguishable from that of the siliceous zeolite catalyst ZSM-5.

The effects of sex, ethnicity, and sexual orientation on self-measured digit ratio (2D:4D).

Abstract: We used self-reported direct finger measurements from 255,116 participants in a BBC Internet survey to investigate the measurement of 2D:4D ratios and their association with sex, ethnicity, and sexual orientation. We found significant sex differences such that males had lower 2D:4D than females and the effect size of the sex differences was greatest for right hand 2D:4D. Mean 2D:4D was lower for right hands than for left hands in men, but lower for left hands compared to right hands in women. The sexual dimorphism in 2D:4D was present across ethnic and country groupings, suggesting that it is universal in humans. However, there was also evidence that mean 2D:4D varied across ethnic groups with higher ratios for Whites, Non-Chinese Asians, and Mid-Easterners and lower ratios in Chinese and Black samples. There were significant differences in 2D:4D across sexual orientation groups but these were confined to men. Male homosexuals and bisexuals had higher mean 2D:4D (suggesting exposure to lower prenatal T) than heterosexuals. The effect was present in Whites, but there was no evidence for the pattern among Black and Chinese participants. In women, there were no significant effects of sexual orientation on 2D:4D. Most studies of sexual orientation effects on 2D:4D have measured finger length from photocopies of the hands. In comparison, our self-reported measures gave higher mean 2D:4D, lower effect sizes, and, in some instances, different patterns of effect size. The implications of our findings for future research into 2D:4D are discussed.

Iron-silica crystallite nucleation by bacteria in a geothermal sediment

Abstract: The recognition of microfossils in ancient sedimentary rocks has confirmed that microorganisms which strongly resemble presentday prokaryotes existed at least 3 × 109 years ago1. Identification of these structures is a difficult task, complicated not only by the simple morphology of microorganisms, but also by our limited understanding of the processes leading to the mineralization of individual cells and their component parts2–4. We have investigated these processes in a natural setting, by examining sediment samples from an acidic hot spring in Yellowstone National Park. Electron microscopy and energy-dispersive X-ray spectroscopy of thin-sectioned specimens revealed remains of bacteria inside accumulations of iron and silica. Bacterial-like forms in successive stages of mineral preservation by silica were also found