Conspectus:
The flexibility, complexity, and size of contemporary organocatalytic transformations pose interesting and powerful opportunities to computational and experimental chemists alike. In this Account, we disclose our recent computational investigations of three branches of organocatalysis in which nonbonding interactions, such as C–H···O/N interactions, play a crucial role in the organization...
Large rivers represent gateways for the transport of
terrigenous and anthropogenic material to the coastal ocean.
Here we document a ∼700 km2 recirculation or bulge associated
with the Columbia River plume that retains recently discharged
river water sufficiently to create a regional bioreactor.
Fueled by a fluvial nitrate source, this...
Global plant genetics research efforts have focused on developing high yielding, stress tolerant, and disease resistant row and field crop varieties that are more efficient in their use of agronomic inputs (water, nutrients, pesticides, etc.). Until recently, a key bottleneck in such research was the lack of high-throughput sensing technologies...
Some authors defending the "hereditarian" hypothesis with respect to differences in average IQ scores between populations have argued that the sorts of environmental variation hypothesized by some researchers rejecting the hereditarian position should leave discoverable statistical traces, namely changes in the overall variance of scores or in variance-covariance relating scores...
A statistically consistent and physically realistic approach for validating vector magnitude measurements is developed, based on a model for random measurement noise that explicitly satisfies a nonnegativity constraint for all “noisy” vector magnitude measurements. Numerical and analytic approximations are used to quantify the nonlinear functional dependence of sample conditional means...
The hepatotoxic alkaloids known to occur in tansy ragwort (Senecio jacobaea L.) are also present in honey produced from the nectar of this species. These alkaloids, which include senecionine, seneciphvlline, jacoline, jaconine, jacobine, and jacozine, are potentially carcinogenic, mutagenic and teratogenic and may pose health hazards to the human consumer.
The previously suggested protection from microbial attack of ripening nectar by the addition of glucose oxidase by the common honey bee, Apis mellifera L., has been found to occur in 9 other eusocial Hymenoptera from 3 superfamilies. The antibacterial effect results from the accumulation of hydrogen peroxide produced by the...
An examination of a commercial honey-bee apiary for the Acarcapis species complex revealed the following: queens were essentially free from Acarapis parasitism: colonies were more frequently
infested with A. dorsaiis and A. woodi than A. externus: individual worker-bee hosts were
rarely parasitized by more than one Acarapis species. Observed sex...
The Critical Depth Hypothesis formalized by Sverdrup in 1953 posits that
vernal phytoplankton blooms occur when surface mixing shoals to a depth shallower than a
critical depth horizon defining the point where phytoplankton growth exceeds losses. This
hypothesis has since served as a cornerstone in plankton ecology and reflects the...
As a result of the Chernobyl accident on April 25, 1986. possible radioactive contamination
of honey bees and cheese sampled in several areas of the United States were measured. Of
bees collected in May and June of 1986 in both Oregon and New York, only those from Oregon
showed detectable...