Search

Syncrude Canada Ltd.’s Base Mine Lake (BML), the first commercial-scale demonstration of an oil sands pit lake, was commissioned in December 2012, following in-pit deposition of fine tailings (FT) between 1995 and 2012. The geotechnical design basis for the FT in BML is that it will consolidate and densify over time, contributing to fines sequestration below the water cap. This paper presents the geotechnical performance of the FT in BML within the context of this geotechnical design basis. The FT has settled from 196.0 to 171.6 Mm3 by 2019, with cumulative settlement varying spatially between 0.3 and 6.7 m. FT settlement is consistent with the expected self-weight consolidation as modeled by finite-strain non-linear consolidation theory, and is reflected as temporal increase in the profiles of solids content and effective stress. Sonar surveying, profile sampling, shear strength, and underwater photography show that the transition of geotechnical properties at the mudline becomes increasingly distinct over time. These observations support the geotechnical design basis for BML and indicate the fines continue to be sequestered below the water cap.

Accumulating evidence suggests that the phenotypes of human males were shaped by contest competition, the mode of sexual selection in which mating opportunities are obtained by using force or threat of force to exclude same-sex competitors. Phylogenetic, paleontological, and archaeological data indicate a great antiquity for male–male violence in our lineage, and human males possess a constellation of traits that suggest specialization for contest competition. Relative to females, males exhibit greater stature, muscle mass, strength, speed, aerobic capacity, ability to dissipate exercise heat loads, craniofacial robusticity, pain tolerance, risk-taking, behavioral displays of physical prowess and acuity to the formidability of same-sex conspecifics, outgroup discrimination, and a propensity to participate in dyadic and coalitional violence. Parallel evidence suggests that some characteristics that distinguish hominins from the other great apes increase formidability in fights (e.g., handheld weapons, habitual bipedalism, and proportions of the hand and face) or function to increase perceptions of dominance (e.g., low vocal frequencies). Many of these traits are consistent with having been shaped by contest competition over mates: they develop or elaborate at sexual maturity and predict success in male contests, mating, and reproduction. Although alternative evolutionary explanations for some of these sexually dimorphic traits are possible, the most parsimonious explanation is that they have been preserved by selection because they aided in contest competition among males throughout human evolutionary history. The evolutionary roots of much of the aggression, intolerance, and violence that plagues modern societies may ultimately lie in the selection that shaped our mating system.

Concentrating on the shifting boundaries and definition of art, Richard Kalina offers a panoramic view of the contemporary art scene over the last 30 years. His focus is on the ongoing development of concepts, the transformation of art worlds and the social matrices in which they are created. Discussing painting in general and abstract painting in particular, his survey takes in photorealism, sculpture and art forms found outside of the modernist tradition. Kalina’s group of artists includes Mel Bochner, Joan Mitchell, Cy Twombly, Franz West, Alma Thomas and Richard Tuttle who, in their ongoing projects, explicitly or implicitly questioned the aesthetic assumptions of their times. Merging an examination of animating philosophies and context – political, social, and personal – with a sharply focused look at the works of art themselves, Kalina brings us closer to understanding the social matrices in which art is embedded and responds to bigger questions about the object nature of the work of art in today’s world.