Search PubMed⌕ Search

Biomedical subjects

W M Liu

Publications and source records attributed to W M Liu.

77 records · Page 5Linked to original sources
PubMed1982

Remarks on origins of biomolecular asymmetry.

A simple criterion for mirror symmetry breaking in a non-linear chemical system is presented. The selection effect of external asymmetric agents in the process of generation and amplification of biomolecular asymmetry is studied. It is pointed out that this effect will play an important role at bifurcation point, but when the asymmetry of a system has been amplified to a certain extent, a weak asymmetric agent will no longer be able to change the chirality of the system.

Mathematics↗
PubMedDate not supplied

Epidemiological models with varying population size and dose-dependent latent period.

Two epidemiological models in a variable-size population are considered. Both have a dose-dependent latent period that depends on the proportion of infectious individuals in the population. In the SEIS model, the proportion of infectious individuals tends to either zero or a stable endemic value. In the SEIRS model, for diseases that confer temporary immunity, periodicity can arise by a Hopf bifurcation.

Communicable Diseases↗
PubMedDate not supplied

A carbon-limited medium for growth and sporulation of Bacillus thuringiensis var. kurstaki.

A culture medium for batch production of d-endotoxin by Bacillus thuringiensis (B., t.) has been modified. Through batch and continuous cultivation studies, the original medium was diagnosed to be limited in organic nitrogen. Corn steep liquor was found to be an excellent source for the organic nitrogen and its addition resulted in a carbon limited medium and in a significant increase in the amount of spore-toxin complex formed in shake flasks. Results of bioassay, conducted on Trichoplusia ni, suggest enhancement of larvicidal efficacy under carbon-limited growth conditions.

Ammonium Sulfate↗