The novel Coronavirus Disease 2019 exposed issues in the supply chain for N95 face masks. The demand for protective face masks spiked globally and domestically due to the unexpected outbreak of the pandemic. An important issue was the dependency on N95 mask production in countries abroad. The focus on face masks in this thesis accounts for all models of the N95 mask.<br/>This thesis will focus on onshore and offshore production of N95 face masks before and during the pandemic. Specifically, we will focus on (1) the production of masks in 2019; (2) 3M, Honeywell, and Prestige Ameritech’s production changes; (3) the observations made by All The Things LLC, a broker for face masks; (4) the rise of counterfeit masks and actions taken to stop counterfeit production; (4) actions taken by the federal government to aid in production and distribution; and (5) future research opportunities on this topic. This research project into the production of N95 face masks ceased in February of 2021. <br/>This thesis defends the critical need for more domestically produced N95 masks. The U.S. needs to increase the number of N95 masks produced domestically, manage the Strategic National Stockpile to eliminate masks past their shelf life, and create a plan to replenish the stockpile to reduce the possibility of a shortage when the next public health emergency takes place.
Nutrient recycling by fish can be an important part of nutrient cycles in both freshwater and marine ecosystems. As a result, understanding the mechanisms that influence excretion elemental ratios of fish is of great importance to a complete understanding of aquatic nutrient cycles. As fish consume a wide range of diets that differ in elemental composition, stoichiometric theory can inform predictions about dietary effects on excretion ratios.
We conducted a meta-analysis to test the effects of diet elemental composition on consumption and nutrient excretion by fish. We examined the relationship between consumption rate and diet N : P across all laboratory studies and calculated effect sizes for each excretion metric to test for significant effects.
Consumption rate of N, but not P, was significantly negatively affected by diet N : P. Effect sizes of diet elemental composition on consumption-specific excretion N, P and N : P in laboratory studies were all significantly different from 0, but effect size for raw excretion N : P was not significantly different from zero in laboratory or field surveys.
Our results highlight the importance of having a mechanistic understanding of the drivers of consumer excretion rates and ratios. We suggest that more research is needed on how consumption and assimilation efficiency vary with N : P and in natural ecosystems in order to further understand mechanistic processes in consumer-driven nutrient recycling.