Exploring sources of inaccuracy and irreproducibility in the CDC bottle bioassay through direct insecticide quantification.

Background: The Centers for Disease Control and Prevention (CDC) bottle bioassay is a commonly used susceptibility test for measuring insect response to insecticide exposure. However, inconsistencies and high variability in insect response when conducting CDC bottle bioassays have been reported in previous publications. We hypothesized that the CDC bottle bioassay results may be compromised when expected and actual insecticide concentrations in the bottles are not equivalent and that inadequate bottle cleaning and/or loss during insecticide introduction and bottle storage steps could be responsible.

Investigating the Effects of Temperature, Relative Humidity, Leaf Collection Date, and Foliar Penetration on Leaf-Air Partitioning of Chlorpyrifos.

Leaf-air partition coefficient () values are needed to understand and predict pesticide volatilization and persistence in agroecosystems. The objectives of this work were to measure values and foliar penetration for the insecticide chlorpyrifos (as an active ingredient alone and in a pesticide formulation) on alfalfa (lucerne) leaves at a range of temperatures and relative humidities and when using leaves collected in different summer months. values were measured using a solid-phase fugacity meter.

Synthesis of -Symmetric Dimeric Re(I) Peptide Complexes.

The reactions of [Re(CO)(HO)]Br or Re(CO)Cl with two peptides, glycylglycine or glycylalanine, were investigated. Each reaction produced a unique, well-defined product. Structural elucidation showed the formation of chiral compounds with the formula [Re(CO)(Gly-Xxx-O)], Xxx = Gly , Ala .