UPI NewsTrack Health and Science News

Climate change affects tornado activity

ATHENS, Ga., July 1 (UPI) -- A U.S. study suggests the climate change effect of dry autumns and winters may lead to fewer tornadoes developing during the spring season.

University of Georgia researchers say global warming will likely mean more unpredictable weather conditions. They said their study indicates how drought conditions in an area's fall and winter may affect tornado activity the following spring.

The scientists said their study was specific to Georgia and the Southeastern United States, but further research could reveal patterns that might make the findings more general.

"Our results suggest that there is a statistically significant reduction in tornado activity during a tornado season following drought the preceding fall and winter," said Associate Professor Marshall Shepherd, a meteorologist and lead author of the study. "On the other hand, wet autumns and winters examined in the study had nearly twice as many spring tornado days as drought years did."

The researchers said they hope that one day meteorologists and climatologists might be able to predict the severity of a spring tornado season the way they now do for hurricanes.

The study that included Professor Thomas Mote, also of the University of Georgia, and Assistant Professor Dev Niyogi of Purdue University appears in the journal Environmental Research Letters.

Human trials sought for AIDS vaccine

LONDON, Ontario, July 1 (UPI) -- Scientists said an HIV/AIDS vaccine developed at Canada's University of Western Ontario is ready for the first phase of human trials.

Officials at Sumagen Co. Ltd., the manufacturer of the vaccine, said they have submitted an investigational new drug application to the U.S. Food and Drug Administration to begin Phase 1 human trials for its SAV001-H AIDS vaccine.

The vaccine was developed by Professor Chil-Yong Kang who, with Sumagen, has completed safety and immunogenicity studies on animals.

University officials said Sumagen Canada has secured patents for the vaccine in more than 70 nations, including the United States, the European Union and Korea. According to the firm, animal testing has resulted in good antibody reactions in immunology tests, with no adverse effects or safety risks.

"The Phase l clinical trials, if approved, will double check the safety of the vaccine using HIV positive volunteers," the university said in a statement. "The second stage -- Phase ll trials -- would then assess the immunogenicity of the vaccine."

Ulysses spacecraft ends 18-year mission

PASADENA, Calif., July 1 (UPI) -- The Ulysses spacecraft, a joint NASA-European Space Agency mission, has officially ceased operations, officials said.

The end-of-mission command was transmitted Tuesday to the spacecraft that operated for more than 18 years, charting the unexplored regions of space above the poles of the sun. When space shuttle Discovery launched Ulysses on Oct. 6, 1990, it had an expected lifetime of five years, NASA said.

"This has been a remarkable scientific endeavor," said Richard Marsden, Ulysses mission manager and project scientist at the European Space Agency. "The results Ulysses obtained have exceeded our wildest dreams many times over."

In addition to measuring the solar wind and charged particles, the spacecraft's instruments measured small dust particles and neutral gases from local interstellar space. NASA said Ulysses also had an unprecedented three chance encounters with comet tails, registering more than 1,800 cosmic gamma-ray bursts and providing findings for more than 1,000 scientific articles and two books.

Ulysses' orbital path is carrying the spacecraft away from Earth, progressively limiting the amount of data transmitted. That prompted Ulysses project managers, with the concurrence of the ESA and NASA, to decide it was an appropriate time to end the "epic scientific adventure," NASA said.

More information about Ulysses is available at http://ulysses.jpl.nasa.gov.

Study may improve genetic counseling

STATE COLLEGE, Pa., July 1 (UPI) -- U.S. scientists studying how some human DNA mutations are involved in inherited diseases say their findings may affect the way genetic counseling is offered.

Pennsylvania State University researchers said their study has shed light on the processes that lead to human DNA mutations implicated in such diseases as tuberous sclerosis and neurofibromatosis type 1.

The scientists, led by Associate Professors Kateryna Makova and Francesca Chiaromonte, examined mutations in which small fragments of DNA are either added or subtracted from the genome. They said they found patterns in the DNA sequences immediately surrounding those mutations.

Chiaromonte said the study is the first to detect patterns in the DNA sequences adjacent to insertions and deletions of DNA fragments at the genome-wide scale.

"We were surprised to find that the patterns … are unique because scientists previously have lumped the two types of mutations together," graduate student Erika Kvikstad said. "What's striking is that most insertions and deletions are thought to occur by replication errors and, while this is a primary source generating the mutations, we discovered that recombination also is very important."

The scientists said that if it's know that certain diseases are more likely to be caused by recombination than by replication errors, physicians can provide better advice to couples who want to have children.

The research is detailed in the July issue of the journal Genome Research.