Linear-viscous flow of temperate ice.

Accurately modeling the deformation of temperate glacier ice, which is at its pressure-melting temperature and contains liquid water at grain boundaries, is essential for predicting ice sheet discharge to the ocean and associated sea-level rise. Central to such modeling is Glen's flow law, in which strain rate depends on stress raised to a power of = 3 to 4. In sharp contrast to this nonlinearity, we found by conducting large-scale, shear-deformation experiments that temperate ice is linear-viscous ( 1.

Recent tropical Andean glacier retreat is unprecedented in the Holocene.

Tropical glaciers have retreated over recent decades, but whether the magnitude of this retreat exceeds the bounds of Holocene fluctuations is unclear. We measured cosmogenic beryllium-10 and carbon-14 concentrations in recently exposed bedrock at the margin of four glaciers spanning the tropical Andes to reconstruct their past extents relative to today. Nuclide concentrations are near zero in almost all samples, suggesting that these locations were never exposed during the Holocene.

Safety and transfer of veterinary drugs from substrate to black soldier fly larvae.

There is an increasing interest in edible insects in Europe for feed and food purposes. Quantitative information on the transfer of chemical hazards from substrates to larvae is needed to evaluate food and feed safety aspects. This evaluation is especially needed when organic substrates or residual streams such as manure will be applied as substrate, contributing to a circular food system.

Effects of dietary exposure to plant toxins on bioaccumulation, survival, and growth of black soldier fly () larvae and lesser mealworm ().

In their natural habitat, insects may bioaccumulate toxins from plants for defence against predators. When insects are accidently raised on feed that is contaminated with toxins from co-harvested herbs, this may pose a health risk when used for human or animal consumption. Plant toxins of particular relevance are the pyrrolizidine alkaloids (PAs), which are genotoxic carcinogens produced by a wide variety of plant species and the tropane alkaloids (TAs) which are produced by a number of Solanaceae species.

A ring shear device to simulate cryosphere processes.

We have developed a new cryogenic ring shear device at the University of Wisconsin-Madison to simulate cryosphere processes, with an emphasis on the physics of glacier slip. The device spins a ring of ice (inner diameter of 20 cm, outer diameter of 60 cm, height of ∼20-30 cm) at the pressure melting point over a rotationally fixed bed. The ice ring is spun at a prescribed velocity (range of ∼0.