Two distinct motors drive cilia movement
University physicists determined that two distinct motor mechanisms of cilia — tiny, stringy fibers — are at work in a single cell. The presence of two different modes of movement could help scientists understand how cilia have adapted to perform a wide variety of cellular functions, according to a study published in the Biophysical Journal Jan. 7.
Cilia look like small hairs protruding from a cell membrane. They are found in most cells in the body and perform functions ranging from waste removal to locomotion. Though they have distinct roles, these different kinds of cilia look similar, according to the study.
This study marks the first time scientists were able to see that cilia in two different places in the same cell are driven by two separate motor mechanisms, said James Valles, chair of the Department of Physics and an author of the paper, in a University press release.
The researchers measured the activity of cilia in a single-celled bacterium with advanced microscopes and cameras. They compared the motion of cilia used for movement with the motion of cilia involved with eating as they altered the viscosity of the solution housing the bacteria, according to the study.
As the solution got thicker, the cilia used to propel the cell slowed down. But the cilia that work to feed the cell did not show as dramatic a drop in activity, according to the study. The dual behaviors of the two classes of cilia suggest that each is driven by a separate motor mechanism.
Future research will address how different molecules in various areas of the cell and different concentrations of these molecules affect each of the motors, Valles said in the press release.
Elders at home at higher risk of preventable hospitalization
Seniors receiving home- or community-based care are 40 percent more likely than those living in nursing homes to be hospitalized for possibly preventable conditions, according to a study published earlier this month in the Journal of the American Geriatrics Society. The study was led by Andrea Wysocki, a postdoctoral research fellow in the School of Public Health.
Many senior citizens prefer home- and community-based care, and these sorts of programs also save Medicaid money, so policymakers have often supported them, according to a University press release.
“We are trying to move people into the community and I think that is a really great goal, but we aren’t necessarily providing the medical support services that are needed in the community,” Wysocki said in the press release.
The researchers recommend that, for better long-term health, measures be taken to ensure senior citizens have a clear care plan and long-term access to healthcare providers when they leave the nursing home for a home- or community-based facility, according to the study.
Starting school later beneficial for teens
There may be scientific evidence behind teenagers’ claims that they should not have to wake up for school early in the morning. A study published this month in the Journal of Developmental and Behavioral Pediatrics found a correlation between later school start times and improved sleep and mood in teens.
“Sleep deprivation is epidemic among adolescents, with potentially serious impacts on mental and physical health, safety and learning. Early high school start times contribute to this problem,” said the study’s lead author, Julie Boergers, associate professor of pediatrics and psychiatry and human behavior, in a Lifespan press release.
Boergers and her team administered sleep habit surveys to students at a boarding school when the start time was 8 a.m., and again once the time was delayed by 25 minutes. They found that adolescents slept an extra 29 minutes when school started later, according to the study.
This additional half-hour of sleep reduced the students’ weariness and caffeine intake. The number of students reporting a depressed mood also decreased.
The students reported spending the same amount of time on homework, sports and extracurricular activities under both conditions, according to the study.
“If we more closely align school schedules with adolescents’ circadian rhythms and sleep needs, we will have students who are more alert, happier, better prepared to learn and aren’t dependent on caffeine and energy drinks just to stay awake in class,” Boergers said in the press release.
Two distinct motors drive cilia movement