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A University researcher in the Department of Soil, Water and Climate has discovered a previously unknown mechanism by which bacteria help legumes create their own nitrogen. The discovery opens the door to the possibility that costly and environmentally damaging nitrogen fertilizers can someday be eliminated from use on soybeans.

Soil bacteria and legumes such as peas and beans have a symbiotic relationship in which bacteria enter plants through the plant’s root hairs and instruct the plants to form nodules where the bacteria can live and convert nitrogen into ammonia. The ammonia, in turn, acts as a fertilizer for the plants. Farmers apply fertilizer to soybeans that aren’t getting enough nutrients through this process.

In the University study, scientists used genome sequencing and found that some bacteria have alternate ways of communicating with the legumes, entering the plant through the cracks between its main stem and branches as well as through cracks in the roots. Researchers called the finding a “new paradigm” in that it demonstrates that bacteria have learned several ways to interact with their host plants. This knowledge, researchers said, will help develop new ways to facilitate the plants’ production of nitrogen.

Corporate executives whose language is focused on the future lead their firms to greater levels of innovation, according to researchers in the University of Minnesota’s Carlson School of Management. The researchers studied data collected from the online banking industry, including words and phrases used by CEOs, over a period of eight years. They found that the more a CEO directed his or her words to the future, the greater the likelihood that the firm would adopt new technologies earlier and develop more innovations faster. Researchers concluded that CEOs who focus their attention on the big picture rather than day-today concerns will influence innovation and future outcomes more than those who have an internal focus.

When business partners set fair, consistent wholesale prices instead of price structures designed to benefit their own bottom line, both businesses profit more. Researchers at the Carlson School of Management at the University of Minnesota and the Wharton School of Business set out to study the concept of fairness in the channel involving a manufacturer and a retailer. They found that when both partners voluntarily aligned their interests and looked beyond initial monetary profits, both benefited by getting a better price in the marketplace.

Invasiveness of prostate cancer is not race-dependent, according to a University of Minnesota study, refuting the common belief that African American patients have more aggressive prostate cancer than white patients. Using preserved slices of tumors from 25 black and 25 white surgery patients at the Minneapolis Veterans Affairs Medical Center—matching them according to patient age, clinical stage of the tumor, and presurgery levels of an antigen that points to the possibility of prostate cancer—the researcher found no significant difference in tumors according to race. In previous studies, prostate tumors in black patients tended to be larger and at a more advanced stage than in white patients and black patients had higher blood levels of the prostate-specific antigen. But other factors, including delayed diagnosis, level of medical care, economic status, and nutrition, may have contributed to those differences.

The number of eligible blood donors in the United States is significantly lower than previously thought. According to researchers in the University of Minnesota’s Academic Health Center, only 37 percent of the U.S. population (111 million people) is currently considered eligible to give blood, whereas earlier estimates indicated that 59 percent (177 million people) were eligible donors. The conventional method of calculating the number of potential blood donors uses only age criteria. The University study considered other factors, such as high-risk behavior, disease exposure, and presence of chronic disease, all of which can exclude donors. The study may help explain why many parts of the country have chronic blood supply shortages and why blood donation rates are low in some communities.

A study by researchers in the Department of Family Social Sciences confirms what other studies have discovered: that gender affects the management of family businesses. But the new study suggests that part of the reason women become involved in family businesses is not to maximize profit, but to spend more time with family members. The research found that family-owned businesses run by women do well financially when family members donate their time to help the company. Conversely, when men run the business, donated family time correlates with less revenue. Researchers believe that the findings can be attributed in part to the tendency of women to use family members routinely as unpaid help, whereas men tend to call on help from family members only when the business is struggling. Another finding showed that fewer women than men who run family businesses opted to put in extra weekly hours in order to increase revenues, leading researchers to theorize that men’s and women’s motives for having a family business may differ. The study used data from the national family Business Survey, which looked at 301 family businesses.

People moving into urban areas across the United States are settling on twice the amount of land as established residents. That is one of several population growth and concentration patterns that emerged from an analysis of U.S. census data from 1950 to 2000 by a civil engineering researcher at the University of Minnesota. This year, for the first time in history, the majority of Americans will live in urban areas, and in coming decades, the growth of urban populations will greatly exceed rural populations. While newcomers to urban areas build bigger houses on larger lots, the average number of people in a mile-wide strip of land across cities remains constant. This is possible because low-density urban growth at the edges of cities is balanced by new high-density housing in urban cores. The data also showed that city sizes have predictable proportions. That is, when cities are ranked from largest to smallest, the population of the second-largest city is half the size of the population of the largest city, and the population of the third-largest city is one-third that of the largest city, and so on. As cities address the implications of urban sprawl—including health, social, and environmental concerns—the study findings offer mathematical predictions regarding city sizes and population distribution in future decades.

One in four high school students in the United States does not graduate, according to University of Minnesota sociologists, a considerably higher dropout rate than most people think. The researchers studied discrepancies in the two major data sources—the U.S. Census Bureau’s Current population Survey (CPS) and the national Center for Education Statistics’ Common Core of Data (CCD) survey—that most governmental and nongovernmental agencies use to report high school dropout rates. CPS shows dropout rates at about 10 percent in recent years and declining 40 percent in the past generation. CCD indicates that high school completion rates have stayed steady at approximately 75 percent in recent decades. The University study attributes much of the discrepancy to how the data sources collect the information. CPS bases its findings on individuals responding to its surveys; CCD bases its reports on administrative records, considered more accurate.

The key to diagnosing Alzheimer’s and other brain diseases might lie in a single point of light, based on findings of research by the University of Minnesota Medical School and the Brain Sciences Center at the Minneapolis Veterans Administration Medical Center. Researchers have identified a noninvasive and painless way to diagnose six brain diseases using magnetoencephalography, which records tens of thousands of brain cells interacting with each other on a millisecond-by-millisecond basis while the subject stares at a single point of light. The study participants fell into one of six categories, including people with Alzheimer’s disease, chronic alcoholism, schizophrenia, multiple sclerosis, or Sjogren’s syndrome, as well as healthy control subjects. The new diagnostic tool classified with 100 percent accuracy the various disease groups represented in the research subjects. Currently, brain-related diseases are diagnosed with a combination of behavioral exams, psychiatric interviews, and neuropsychological testing.

Researchers in the University of Minnesota Medical School have discovered that treating early, asymptomatic cardiovascular abnormalities can slow and even reverse damage to the heart and blood vessels. Most cardiovascular diseases are the result of a progressive problem that can be detected long before symptoms develop. The research is the first to show that early intervention, with drugs and/or lifestyle changes, can lead to the reversal of cardiovascular abnormalities. The research was based on a 10-factor scale, called the Rasmussen Disease Score, which measures artery elasticity, blood pressure, carotid artery thickness, and other factors. The Rasmussen Disease Score was developed by Jay N. Cohn, M.D., director of the U’s Rasmussen Center for Cardiovascular Disease Prevention.

University of Minnesota astronomers have discovered a hole in the universe nearly a billion light years across—that translates to 6 billion trillion miles—that dwarfs all previously known voids. Scientists have documented other holes in the structure of the universe, but this one is by far the largest ever found. The area is not visible with the human eye, but if it were, it would cover an expanse roughly 40 times the size of the full moon. The void appears in the constellation Eridanus, southwest of Orion, a region 6 to 10 billion light years from Earth that had already stood out because of irregularities in its structure. The area is devoid of all normal matter, such as stars, planets, galaxies, and gas, as well as dark energy, which forms 85 percent of the matter in the universe but emits no light. The finding casts doubt on scientists’ previous assumption that the universe has an even distribution of matter.

A common amino acid that is available as a supplement shows promise in helping curb pathological gamblers’ addiction, according to researchers in the University of Minnesota Medical School. n-acetyl cysteine, which affects the brain’s reward centers, was found to reduce people’s urge to gamble in a recent eight-week trial. Similar studies of the supplement have shown its ability to curb drug addictions in animals, and a current University of Minnesota study is investigating whether it could help methamphetamine users quit.

Users of smokeless tobacco are exposed to higher amounts of cancer-causing agents than cigarette smokers, according to researchers at the University of Minnesota Cancer Center. The findings prompted researchers to conclude that, despite claims to the contrary, smokeless tobacco is not a safe alternative to cigarettes—and may, in fact, be a more efficient method of delivering carcinogens to the body. Study participants included 182 men and women aged 17 to 80 who had sought, but not yet begun treatment for, tobacco addiction and who used popular U.S. brands of smokeless tobacco. Data collected from these subjects was compared to that collected from 420 smokers who had participated in earlier studies. Smokeless tobacco, also known as oral snuff, is a variant on chewing tobacco that users place between their cheeks and gums.

Researchers at the University of Minnesota Medical School have developed a treatment that allows more patients with blood cancer to have a life-saving procedure. By using less toxic doses of chemotherapy and radiation than those typically used in preparation for blood and marrow transplantation, combined with umbilical cord blood that requires a less stringent donor match, the researchers were able to offer transplants to people who previously did not qualify for transplantation because of age, extensive prior therapy, organ dysfunction, or lack of match donor. Advances in cancer treatment have allowed more people with leukemias and lymphomas to achieve remissions, but many are not cured with chemotherapy alone. The new method bridges a gap for large numbers of patients who are excluded because of older age and lack of donors. The research involved 110 adults who had been disqualified from conventional therapies. Approximately 45 percent were living three years after their transplant. fewer than 5 percent were expected to live without transplant.

Minority preschoolers from low-income families who participated in school-based intervention programs fared better decades later educationally, socially, and economically than peers who did not have the benefit of such programs, according to researchers in the College of Education and Human Development and the Humphrey Institute of Public Affairs at the University of Minnesota. The study is the first to demonstrate that such programs can have enduring benefits into adulthood. Specifically, researchers found that children who were involved in preschool programs were more likely than others to finish high school, attend four-year colleges, and have health insurance coverage. Likewise, they were less likely to be arrested for a felony, incarcerated, or develop depressive symptoms. The study, called the Chicago Longitudinal Study, began in 1986 to investigate the effects of government-funded preschool programs for 1,539 children in the Chicago Public Schools.