Advances

(Advances gives a glimpse of the many significant research projects at the university. Tell us about your discoveries by e-mailing: wisweek@news.wisc.edu.) Determining hydraulic conductivity of materials
A newly patented method and apparatus for testing the hydraulic conductivity of materials such as clay, rock and soil means these tests can be completed in minutes, rather than weeks.

Xiaodong Wang, geotechnical laboratory manager for the Department of Civil and Environmental Engineering, and, Craig Benson, Civil and Environmental Engineering professor, have devised a new American Society for Testing and Materials-approved invention to improve hydraulic conductivity testing.

The new invention includes instruments for measuring the hydraulic conductivity of materials using a closed-loop system. The geological sample is placed within a test fluid under a constant pressure and the fluid flow is regulated so that a constant volume of test fluid is within the sample. This invention eliminates variation in pressure difference, which is believed to cause errors in the calculation of hydraulic conductivity, and decreases the amount of time needed to reach a steady state flow of water across the sample.

Molecular snippets may hold viruses at bay
In a surprising find, university scientists have uncovered the antiviral properties of an obscure class of peptides that may someday provide a powerful way to curb sexually transmitted diseases.

Led by professor of ophthalmology and medical microbiology Curtis Brandt, the team of researchers discovered that several so-called membrane transit peptides — parts of certain protein molecules with a special ability to traverse membranes — prevent cell infection by three major STD-causing viruses: herpes simplex virus, papilloma virus and HIV.

The peptides are synthetic but are based on natural transit peptide sequences from diverse sources, including the fruit fly Drosophila and HIV itself. Although Brandt hasn’t determined their precise mode of action, the peptides seem to interact directly with virus particles to permanently inactivate them.

Transit peptides could eventually be added to contraceptive products, such as vaginal creams and foams, to prevent STD infection. Although they wouldn’t provide 100 percent protection, their use could drop the incidence of viral transmission dramatically, says Brandt.

Softening up microbes for assault by agents
Found in everything from toothpastes, soaps and cosmetics, to sponges, cutting boards and baby toys, antibacterial agents are seemingly as ubiquitous these days as the microbes they target. But as the use of antibacterial agents in everyday items has soared, so have fears about the emergence of resistant bacteria.

Now, Eric Johnson and Byron Brehm-Stecher, scientists with the Food Research Institute, have devised a promising way to keep microbes vulnerable to germ-killers, using plant-derived compounds called sesquiterpenoids.

The researchers found that when teamed with small amounts of sesquiterpenoids, several antibiotics and other antibacterial agents became much better at killing bacteria, including some pathogenic strains. Their discovery could pave the way for new antibacterial formulations that would be effective at much lower doses in consumer products.

Sesquiterpenoids could also extend the life of antibiotics and antiseptics that might otherwise be vanquished by resistant microbes — a concern that keeps the pharmaceutical, food and sanitation industries constantly searching for new germ-killing agents.