Intensity of cannabis use: Findings from three online surveys.

Background: Drug use is often measured in terms of prevalence, meaning the number of people who used any amount in the last month or year, but measuring the quantity consumed is critical for making informed regulatory decisions and estimating the effects of policy changes. Quantity is the product of frequency (e.g.

Triangulating web & general population surveys: Do results match legal cannabis market sales?

Background: This paper combines complementary attributes of web and general population surveys to estimate cannabis consumption and spending in Washington State. It compares those estimates to legal sales recorded by the state's seed-to-sale tracking system, and thus exploits a rare opportunity to contrast two independent estimates for the same cannabis market. This sheds light on the question of whether nontrivial amounts of black market sales continue even after a state allows licensed production and sale.

A Hybrid Causal Search Algorithm for Latent Variable Models.

Existing score-based causal model search algorithms such as (and a speeded up version, ) are asymptotically correct, fast, and reliable, but make the unrealistic assumption that the true causal graph does not contain any unmeasured confounders. There are several constraint-based causal search algorithms (e.g , or +) that are asymptotically correct without assuming that there are no unmeasured confounders, but often perform poorly on small samples.

Classification of the environment of protein residues.

We have studied the classification of the environment of residues within protein structures. Eisenberg's original idea created environmental categories to discriminate between similar residues [Bowie et al., Science (1991), 253, 164-170].

Species-specific long range interactions between receptor/ligand pairs.

Total internal reflection microscopy (TIRM) monitors Brownian fluctuations in elevation as small as 1 nm by measuring the scattering of a single sphere illuminated by an evanescent wave when the sphere is levitated by colloidal forces such as electrostatic double-layer repulsion. From the Boltzmann distribution of elevations sampled by the sphere over time, the potential energy profile can be determined with a resolution of approximately 0.1 of the thermal energy kT.