Dolphin population hindered by fishing
SAN DIEGO, Nov. 24 (UPI) -- Fishing activities are stunting population growth of a type of Pacific Ocean dolphin despite dolphin-safe practices, U.S. university researchers said.
The study by Scripps Institution of Oceanography at the University of California-San Diego revealed negative impacts from fishing activities remain, despite adoption of regulations and agreements designed to reduce dolphin deaths from "by-catch" in which animals are caught unintentionally along with the intended targets.
The research by the university and the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center showed fishing activities disrupted the reproductive yield of the northeastern pantropical spotted dolphin, the university said in a news release. Researchers note that reproductive output of the eastern spinner dolphin also declined, but finding a direct link to fishing was inconclusive.
The conclusions are based on surveys between 1987 and 2003 conducted by NOAA Fisheries Service designed to assess the size and general health of dolphin populations in the eastern Pacific Ocean.
Collisions helped form disk galaxies
PITTSBURGH, Nov. 24 (UPI) -- Violent intergalactic collision created the bright pinwheels and broad star sweeps typical in disk galaxies such as the Milky Way, U.S. researchers found.
The multi-institutional team's simulated galaxy formation suggests disk galaxies likely began as flat, centralized star clusters, the University of Pittsburgh, one of the institutions, said in a news release. Smaller galaxies ripped through these disks billions of years ago, casting disk stars outward into the galaxies' current shapes, their research found.
In addition, huge bodies of dark matter -- a low-density, high-gravity invisible mass -- moved through the disks, pulling stars from the core, researchers said.
"Our model suggests that a violent collision throws stars everywhere and continues moving through the disk, disturbing its structure," said Andrew Zentner, a Pitt professor of physics and astronomy. "It also has been known for some time that for star spirals to develop and maintain their well-known form, there must be a prolonged disturbance. We show that large masses moving through a galaxy could provide that disturbance."
Researchers predict vaccine's immunity
ATLANTA, Nov. 24 (UPI) -- U.S. researchers say they've discovered a way to predict how successful vaccines would be in triggering immune responses.
In the first-ever study, researchers at the Yerkes National Primate Research Center and Emory Vaccine Center at Emory University said they used immunology, genomics and bioinformatics to predict a vaccine's immunity without exposing individuals to infection -- a long-standing challenge in the development of vaccines.
The team, using the yellow fever vaccine as a model, wanted to determine why the vaccine -- one of the most successful vaccines ever -- was so effective so they could design equally effective new vaccines against global pandemics and emerging infections, the Atlanta university said in a news release.
"A single shot of the (yellow fever) vaccine induces immunity in many people for nearly 30 years," said Bali Pulendran, lead Yerkes researcher and professor in the Department of Pathology and Laboratory Medicine at Emory University School of Medicine. "Despite the great success of the yellow fever vaccine, little has been known about the immunological mechanisms that make it effective."
Pulendran said the team, using several lines of study, identified distinct gene signatures that were correlated to the antibody response induced by the vaccine.
To determine whether the gene could predict immune response, "we vaccinated a second group of individuals and were able to predict with up to 90 percent accuracy which of the vaccinated individuals would develop" immunity to yellow fever.
Anti-viral drug shows promise
DALLAS, Nov. 24 (UPI) -- An anti-viral drug developed at University of Texas-Southwestern shows potential as a strategy against viral diseases, researchers said.
The Dallas university researchers infected groups of guinea pigs with a virus similar to Lassa fever virus. The animals recovered from the virus when treated with the UT-Southwestern-developed bavituximab alone or in combination with another anti-viral medication, the university said in a news release.
Bavituximab treatment also cured mice infected with cytomegalovirus, an opportunistic infection that afflicts transplant and AIDS patients, researchers said.
"When injected into the bloodstream, bavituximab circulates in the body until it finds these inside-out lipids and then binds to them," said Philip Thorpe, professor of pharmacology. "In the case of virus infection, the binding raises a red flag to the body's immune system, forcing the deployment of defensive white blood cells to attack the infected cells."
In the study, half of the guinea pigs infected with a virus similar to Lassa fever were cured when bavituximab was administered alone. Researchers said this is the first report of a therapeutic treatment being effective against advanced Lassa-like fever infections in animals. When combined with ribavirin, 63 percent of guinea pigs survived.
Lassa fever is an endemic disease in portions of West Africa. As a hemorrhagic fever virus, the Centers for Disease Control in Atlanta classifies Lassa is as a Category A bioterrorism agent, the same categorization as the Ebola and Marburg viruses.
