20,060 research outputs found
Diurnal and Seasonal Activity of Female Mutillids on a Michigan Sand Flat (Hymenoptera: Mutillidae)
Diurnal activity of mutillid females of a southwestern Michigan sand area was characterized in relation to sand surface temperature conditions. Seasonal abundance patterns weredetermined for four Dasymutilla species
Bionanomaterials from plant viruses
Plant virus capsids have emerged as useful biotemplates for material synthesis. All plant virus capsids are assembled with high-precision, three-dimensional structures providing nanoscale architectures that are highly monodisperse, can be produced in large quantities and that cannot replicate in mammalian cells (so are safe). Such exceptional characteristics make plant viruses strong candidates for application as biotemplates for novel and new material synthesis
Templated mineralization by charge-modified cowpea mosaic virus
Templated mineralization of virus particles provides routes to narrowly dispersed nanoparticles that are not readily prepared by other means. The templated mineralization of metal or metal oxide on the external surface of wild-type cowpea mosaic virus (CPMV), a plant virus, is facilitated by increasing the external surface negative charge. This is achieved by the chemical modification of surface lysine groups by succinic anhydride. Hence, for example, treatment of charge-modified CPMV succinamate with a 1:2 mixture of iron(II) and iron(III) salts, followed by raising the pH to 10.2, led to the formation of narrowly dispersed, CPMV-templated, magnetite (Fe3O4) nanoparticles
Polyelectrolyte-modified cowpea mosaic virus for the synthesis of gold nanoparticles
Polyelectrolyte surface-modified cowpea mosaic virus (CPMV) can be used for the templated synthesis of narrowly dispersed gold nanoparticles. Cationic polyelectrolyte, poly(allylamine) hydrochloride, is electrostatically bound to the external surface of the virus capsid. The polyelectrolyte-coated CPMV promotes adsorption of aqueous gold hydroxide anionic species, prepared from gold(III) chloride and potassium carbonate, that are easily reduced to form CPMV-templated gold nanoparticles. The process is simple and environmentally benign using only water as solvent at ambient temperature
A Note on Adult Overwintering of Dasymutilla Nigripes in Michigan (Hymenoptera: Mutillidae)
Excerpt: Although Dasymutilla nigripes (Fabricius) is one of the more common Michigan velvet ant species, little is known about its life cycle. In his summary of mutillid life cycles, Michel (1928) indicated that mutillids of northern latitudes probably overwinter in the prepupal stage within the subterranean cells of their hymenopterous hosts. Bohart and McSwain (1939) cited prepupal overwintering as normal for Dasymutilla sackenii (Cresson) in California. However, Potts and Smith (1944), also working in California, collected overwintering adult female Dasymutilla aureola pacifica (Cresson)
Taking up the Slack: Lessons from a Cap-and-Trade Program in Chicago
The Emissions Reduction Market System (ERMS), an emissions-trading program for volatile organic materials (VOMs) in Chicago, Illinois, has been characterized by emissions significantly below the annual allocation of emission allowances, allowance prices much lower than predicted, limited trading, and emission allowances that expire unused. Essentially, it appears that a fundamental prerequisite for a tradable allowance program is missing—there is no scarcity of allowances. We evaluate a variety of hypotheses that may explain why the ERMS cap does not appear to be affecting abatement behavior and identify three that contributed to the lack of scarcity in the ERMS program: (1) a baseline process that inflated the cap; (2) hazardous air pollutant regulations that contributed to VOM reductions at some sources; and (3) numerous facility shutdowns. We conclude that the ERMS experience illustrates the inherent unpredictability of economic, regulatory, and other factors when setting an emissions target; a conclusion that resonates with the recent experience of the European Union Emissions Trading Scheme. This argues for gathering reliable emissions data, developing sophisticated emissions projections, and making transparent assumptions about the impacts of other policies and regulations during the program planning and design phase. However, even with all these attributes, it is still difficult to anticipate every possible outcome. Thus, it is desirable to have robust mechanisms to address the uncertainties of emissions-trading markets and to make midcourse corrections if necessary. Finally, we offer some comments on how to think about the results of ERMS versus a hypothetical command and control program that might have been designed to reach the same environmental outcome.emissions-trading, ERMS, European Union, climate change
Tradable Rights to Emit Air Pollution
The use of cap-and-trade to regulate air pollution promises to achieve environmental goals at lower cost than traditional prescriptive approaches. Cap-and-trade has been applied to various air pollutants including sulfur dioxide, nitrogen oxides, and volatile organic compounds in the United States and carbon dioxide in the European Union. This corresponds to what is likely to become the most expensive environmental undertaking in history—the effort to reduce the heating of the planet. However, the efficacy of a cap-and-trade policy for carbon dioxide depends in large part on the design of the program. In addition to the level of the cap, the most important decision facing policymakers will be the initial allocation of emissions allowances. The method used to allocate tradable emissions allowances will have significant influence on the distributional impact and efficiency of the program.cap-and-trade, emission allowances, allocation, auction, grandfathering, climate change, global warming, carbon dioxide
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