Agri-food supply chains in North America have become remarkably efficient, supplying an unprecedented variety of items at the lowest possible cost. However, the initial stages of the COVID-19 pandemic and the near-total temporary loss of the foodservice distribution channel, exposed a vulnerability that many found surprising. Instead of continued shortages, however, the agri-food sector has since moved back to near normal conditions with prices and production levels similar to those typically observed in years prior to the pandemic. Ironically, the specialization in most food supply chains designed for “just-in-time” delivery to specific customers with no reserve capacity, which led to the initial disruptions, may have also been responsible for its rapid rebound. A common theme in assessing the impacts across the six commodities examined is the growing importance of understanding the whole supply chain. Over the longer term, a continuation of the pandemic could push the supply chain toward greater consolidation of firms and diversification of products given the increasing option value of maintaining flexibility. Other structural changes will be felt through input markets, most notably labour, as the trend toward greater automation will continue to accelerate as a response to meeting concerns about a consistent supply of healthy and productive workers. The economic fall out from the pandemic may lead to greater concentration in the sector as some firms are not able to survive the downturn and changes in consumer food buying behaviour, including movement toward online shopping and enhanced demand for attributes associated with resiliency, such as local. On the other hand, online shopping may provide opportunities for small producers and processors to shorten supply chains and reach customers directly. In the long term, COVID-19 impacts on global commerce and developing country production are more uncertain and could influence poverty reduction. While COVID-19's impacts on North American agriculture should have minimal effect on the Sustainable Development Goals (SDGs) through food prices, the ongoing global trends in trade and agribusiness accelerated by the pandemic are relevant for achievement of the SDGs.

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Nine structurally related porphyrins are studied and it is shown how the material parameters that control the optical limiting depend on the molecular structure. Optical limiting measurements at 532 nm on the metal-free, zinc and lead analogues of tetraphenyl porphyrin (TPP), tetra(trimethylsilyethynyl) porphyrin (TTMSAP) and tetra(4-n-butylphenylethynyl) porphyrin (TNBBAP) reveal a strong dependence on the metal atom and peripheral substitution. A double pump/cw probe technique is used to measure the material parameters that control the optical limiting and the results give a strong insight into how the molecular structure influences the individual parameters. These measurements revealed that one of the materials TTMSAP(Pb) has a σex/σgr ratio of ∼45 at 532 nm, which is one of the largest values ever reported. Finally, broadband measurements with a picosecond white-light source show that the position and strength of the excited state absorption features also depend strongly on the porphyrin design.

Canada and the United States have strong economic ties and form part of an integrated North American pork industry. Canada's pork industry is export‐oriented, and the United States represents a key market for both live pigs and pork. Pork value chain stakeholders include input suppliers, pig producers, transportation companies, slaughter plants, wholesalers, and retailers. There are three overriding areas of concern for the Canadian pork industry with respect to potential impacts of the current pandemic (COVID‐19). The first is Canada/US trade and the ability to continue exporting Canadian live pigs and pork to the United States. The second is labor and the impact of potential absenteeism on all sectors of the pork value chain. The third is global trade, because Canada's pork industry relies heavily on exporting pork to markets around the world.

meso‐Tetrakis{4‐[2‐(trimethylsilyl)ethynyl]phenyl}porphyrin [TPP(4‐CCTMS)_H2] and its complexes with ZnII, NiII, GaIII, InIII, and SnIV were synthesized and characterized. Their nonlinear optical transmission characteristics were determined using a 532 nm, 5 ns pulsed laser at a repetition rate of 20 Hz. Stronger nonlinear absorption was obtained with the zinc derivative, ZnII‐meso‐tetrakis{4‐[2‐(trimethylsilyl)ethynyl]phenyl}porphyrin (TPP(4‐CCTMS)_Zn), than with the standard analogues, ZnII‐meso‐tetraphenylporphyrin (TPP_Zn), and ZnII‐meso‐tetratolyl‐porphyrin (TTP_Zn), indicating that the excited‐state absorption can be influenced via fine molecular modification on the para‐position of the meso‐phenyl rings, without changing the ground‐state absorption. The nonlinear optical response can be further enhanced via insertion of closed‐shell metal ions. In particular, InIIICl‐meso‐tetrakis{4‐[2‐(trimethylsilyl)ethynyl]phenyl}porphyrin (TPP(4‐CCTMS)_InCl), exhibited a larger change in transmission with increasing energy than C60 and a comparable change to the state‐of‐the‐art phthalocyanine dye, chloro(tetra(tert‐butyl)phthalocyanato)indium(III) (Pc(t‐Bu)_InCl).