When Salmon meets Saran Wrap: Settler Colonial Placidity and Anti-Relationality in Ktaqmkuk

This article uses white Canadian settler artist Mary Pratt’s photorealistic paintings of salmon to grapple with the ways in which settler colonialism necessitates anti-relationality between humans and the non-human world. I trace Indigenous (Beothuk and Mi’kmaq) histories of salmon in Ktaqmkuk|Newfoundland to grapple with what Pratt’s seemingly placid visions of everyday domestic settler life violently erase, concluding by with representations of salmon by Beothuk artist Shanawdithit.

The effects of CO2 and membranes on sporulation in axenic cultures of flax rust

Uredospore production by axenically grown flax rust (Melampsora lini (Ehrenb.) Lev.) was measured as carotenoids (extinction units at 458 nm) per milligram protein. Sporulation was not affected by raising (flushing with 1–5% (v/v) CO2 in air) or lowering (KOH well in culture flasks) the level of CO2 in the air space above the cultures. Significant (two- to four-fold) increases in sporulation occurred beneath impermeable membranes of Parafilm or Saran wrap placed on the surface of young (3 weeks from seeding) mycelial mats for 2 weeks. The stimulatory effect was confined strictly to those areas of the mycelial mats in contact with the membranes. Both Parafilm and Saran wrap were easily and cleanly peeled away from the mycelial mats. Permeable Unipore and HVHP membranes, to which the fungus adhered strongly, did not stimulate sporulation. The fungus did not adhere to Unipore or HVHP membranes treated with silicone or paraffin oil; membranes thus treated stimulated sporulation. The stimulatory effect of membranes on sporulation appears to depend on the nature of the contact between the membrane surface and the mycelium and to be unrelated to the effect of the membranes on the diffusion of gases or other volatile substances.

Complex serine proteases and associated regulatory elements in the human complement system: A transmission EM study

An unusual negative staining method for TEM of biological macromolecules, termed the pleated sheet technique, has been exploited to study the molecular architecture of two sets of functionally similar bimolecular serine proteases and their regulatory elements of human complement. In this technique, macromolecules are adsorbed to a carbon film by the Valentine procedure and the film subsequently pleated while in contact with a 1% uranyl formate solution to trap stain with sample in the folds of pleats. A 400 mesh copper grid is placed on the compressed film, and film plus grid retrieved with a Saran Wrap drum. Subsequent dehydration produces a filmed grid containing negatively stained macromolecules within pleated regions and positively stained macromolecules in single sheet regions (Fig. 1A, 1B). The effect of sandwhiching sample and stain between carbon layers is to produce exceedingly uniform negative staining so that stain contours more accurately and more reproducibly reflect true molecular contours.

Fungistatic properties of soils exposed to different antecedent environments

A Toledo silty clay soil with different cropping histories was tested for fungistatic activity by an agar-ring method using Bipolaris sorokiniana (Sacc.) Shoemaker as the assay organism. Although all soils exhibited considerable fungistatic activity, the magnitude varied only slightly with their cropping histories. Fungistatic activity of soil cropped to alfalfa was somewhat higher than that of soil obtained from rotation plots with oats or soybeans as the last crop. Attempts were made to extract fungistatic material from soil using water, ethanol, or ether. Although the fungistatic properties of the extracts were lost when sterilized by steam or filtration, nonsterilized extracts were inhibitory to the test fungus.Nutrient studies revealed that fungistasis was suppressed when sucrose, peptone, or yeast extract was added to the soil. Evidence was obtained that soil toxin penetrated Millipore filters and cellophane when they were used as substrates in bioassay of soil fungistasis. Fritted glass, clay filters, Saran wrap, and parchment paper were unsuitable for detecting fungistasis since they were inhibitory to the assay fungus. Evidence in support of the theory that food material added to or along with the test conidia increased soil fungistasis was not demonstrated. Conversely, our findings suggest that soil fungistasis is a natural phenomenon, which is characteristic of certain soils.