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University of Minnesota astrophysicists led an international team that discovered the presence of cosmic dust where it had never been found before. Using NASA’s Spitzer Space Telescope, the team found dust deep within a pack of stars that is probably 12.5 billion years old, dating back to the early days of the Milky Way galaxy. The discovery suggests that the deaths of smaller, humbler stars—rather than the violent explosions of giant stars—may have supplied the early dust that seeded myriad stars like the sun. Identifying sources of dust not only helps researchers draw a picture of how the solar system formed, but can help in searches of the cosmos for events that may lead to the formation of new stars and planets. Researchers say the ancient stars that contained the dust may be models of what the first stars in the universe were like.

Child Cancer Survivors at Risk

Survivors of childhood cancers who underwent radiation treatment are more likely than others to have brain and spinal column tumors later in life, according to U research. Researchers said the findings underscore the critical importance of prolonged medical follow-up for all childhood cancer survivors.

Researchers reviewed information from more than 14,300 five-year survivors of childhood cancer who are participating in the U’s Childhood Cancer Survivor Study and found that 116 of them developed subsequent tumors of the brain and central nervous system. The extent of the risk of developing secondary cancer depended on the site of the original cancer, age at diagnosis, and the primary treatment given.

Radiation treatment was linked to a higher risk for developing both malignant and benign brain tumors later in life. The risk of a second tumor increased as the dose of radiation used to treat the first cancer increased. Children under age 5 had an especially high incidence of secondary brain tumors, leading researchers to conclude that the developing brain of a young child is particularly susceptible to the effects of radiation.

Targeting HIV

Researchers at the University of Minnesota have identified a protein that enables viruses such as the human immunodeficiency virus, or HIV, to infect cells and spread through the body. The discovery lays the groundwork for the development of new drugs that can stop the virus from spreading. HIV, the virus that causes AIDS, does not have enough proteins of its own to complete its life cycle; thus, it feeds on proteins in the cells that it infects. Currently, the only drugs that are available to fight HIV act on proteins that the virus itself produces. Since the virus constantly changes, the drugs eventually become ineffective.

The World Health Organization reports that in 2005, 40.3 million people worldwide lived with HIV infection. In that same year, 3.1 million people died of HIV/AIDS, and there were 4.9 million new cases.

A Breath of Hope

For the first time ever, researchers have taken stem cells from umbilical cord blood and coaxed them into becoming lung cells. University of Minnesota researchers say the procedure is a step toward understanding lung development and disease. The cord blood cells changed into a type of lung cell called type II alveolar cells, which play a crucial role in allowing air to move in and out of the lungs and in helping repair airways after an injury. Fetuses develop type II alveolar cells late, which is why some premature babies are born with underdeveloped lungs. The cells and air sacs in the lungs continue to mature and develop through a child’s first few years of life. By helping scientists understand how lung disease evolves, the cells could lead to the development of new treatments for babies who are born with cystic fibrosis and other lung conditions.

Dental Care OK for Expectant Moms

Expectant mothers need not worry about harming their fetus by receiving dental care for gum disease, according to researchers at the University of Minnesota School of Dentistry. Researchers found that pregnant women who have gum disease are not at increased risk of giving birth prematurely, a finding that goes counter to past research, which associated maternal periodontal disease with an increased risk of preterm birth, low birth weight, infant mortality, and long-term health problems for the child.

Scientists suspected that bacteria from infected gums could enter the bloodstream and cause the immune system to provoke changes in tissues and organs elsewhere in the body, leading to premature labor. But research at the U concluded that treatment for gum disease during pregnancy is safe, effective, and does not significantly change rates of preterm birth, low birth weight, or problems with fetal growth. The research is important because it demonstrates that expectant mothers can maintain oral health without fear of risking the health of their fetus.

Periodontal disease is not caused by pregnancy, but pregnant women often experience bleeding gums, a condition thought to be caused by increased levels of female hormones that favor the growth of certain oral bacteria.

Fast Fuel

A University scientist has discovered a process that could be the first step toward creating usable fuels from biomass—plant wastes like sawdust, cornstalks, yard clippings, or trees. The process, called flash volatilization, generates a mixture of hydrogen and carbon monoxide gases from soy oil and sugar by exposing them to extreme heat in only one-hundredth of a second. It works 10 to 100 times faster than current technologies and could be done in facilities about 10 times smaller than today. Currently, soy oil can be modified to make biodiesel, but the process requires the addition of methanol, a fossil fuel derived from natural gas. Likewise, the current technology that transforms sugars into ethanol or other fuels is time-intensive and requires special enzymes.

Service Economy No Fix for Climate Change

The findings of a study by a University of Minnesota researcher challenge the accepted view that the shift toward a service-based economy will automatically result in a reduction of greenhouse gases in the air. Using a life-cycle assessment approach to quantify the environmental effects of products and services, the research analyzed 44 emissions generated by service industries such as hospitals, real estate, and banking. It found that while such industries directly create only about 5 percent of total greenhouse gas emissions, they consume large quantities of electricity, natural gas, transportation, building installations and manufactured goods, all of which generate greenhouse gases. Additionally, as the service industry expands the total volume of greenhouse gases produced in the U.S. economy could go up. The study noted that mitigation of climate change requires the actual reduction of greenhouse gas emissions in absolute terms, and that this cannot be achieved if the service sector is dependent on products that create such emissions.

Diet Pill Dilemma

High school–aged girls’ use of diet pills nearly doubled in a five-year period and continued to increase as they entered their 20s, according to researchers at the University of Minnesota who studied the eating and related habits of 2,500 teenage girls. In early adolescence, 3.5 percent of the girls reported using diet pills. By middle adolescence, that number had risen to 14.2 percent. Further, girls’ physical activity was found to drop dramatically, to less than four hours per week, whereas boys in the same age group spent about six hours a week in physical activity.

The study found that teenaged boys were half as likely as girls to adopt unhealthy weight control behaviors, including diet pills, laxatives, vomiting, and skipping meals. Researchers said they found that teenage girls who diet and use unhealthy weight control behaviors are three times more likely than their peers to be overweight, whereas teens who feel good about their bodies eat better and have less risk of being overweight.

Researchers called the findings “startling.” They identified several possible reasons for the increase in diet pill use, including pressure to be thin and the promise of fast results from diet pills; greater availability of over-the-counter weight-loss drugs and herbal supplements; and increased advertising of such products, particularly over the Internet. Researchers also underscored the key role that parents can play in helping their children build a positive body image and engage in healthy eating and physical activities.

—Edited by Cynthia Scott