High-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hextane-ethyl acetate-methanol-water (1.5:1:1.5:1, v/v/v/v) was applied to the isolation and purification of attractants from Chinese cockroach, Eupolyphaga sinensis Walker. Two new attractants with attractant activity towards the male insects were obtained from the extract sample in a one-step separ...

INTRODUCTION Many efforts have been made to ease the burden of malaria through vector control, among whichis the development of odor-baited traps and evaluation of efficient attractants that could replace host odor. However, most traps and evaluated attractants are expensive, which poor communities cannot afford. This study was conductedwith the aim to devise asimple and affordable odor-baited ...

Attractant was added to a suspension of bacteria (the background concentration of attractant) and then these bacteria were exposed to a yet higher concentration of attractant in a capillary. Chemotaxis was measured by determining how many bacteria accumulated in the capillary. The response range for chemotaxis lies between the threshold concentration and the saturating concentration. The breadt...

The signal transduction cascade responsible for bacterial chemotaxis serves as a model for understanding how cells perceive and respond to their environments. Bacteria react to chemotactic signals by migrating toward attractants and away from repellents. Recent data suggest that the amplification of attractant stimuli depends on receptor collaboration: occupied and unoccupied chemoreceptors act...

A number of peptides were evaluated as chemoattractants for Pseudomonas aeruginosa. Several strains recognized tri-, tetra-, penta-, and hexapeptides in a capillary tube assay. Tripeptides altered at the carboxyl terminus were good attractants, whereas tripeptides altered at the amino terminus did not serve as chemoattractants. Methionine-containing peptides were relatively poor attractants. Ar...

The nematode Caenorhabditis elegans is attracted by at least four classes of attractants: by cyclic nucleotides, cAMP and cGMP; by anions, Cl(-), Br(-), I(-); by cations, Na(+), Li(+), K(+), Mg(+); and by alkaline pH values. The nematode's behavioral response to gradients of these attractants involves orientation and movement up the gradient, accumulation, and then habitutation. Comparison of t...

The role of olfactory sexual attractants in the sex behavior of primates is discussed. These olfactory cues can prompt mounting, masturbation, and ejaculation, increase grooming behavior, and reduce aggressive behavior. In rhesus monkeys, the addition of phenylpropanoic and parahydroxyphenylpropanoic acids to a synthetic acid mixture has been shown to enhance the effectiveness of the syntheti...