2019 Honorable Mention, Northwestern Scientific Images Contest. Water vapor condenses into droplets when it encounters a cold surface. The surface was made to be a wavy pattern. Condensed droplets periodically change in size from the apex to the valley, just like strawberries growing on a freshly tilled farm. The first mature strawberry in the middle (dyed in red intentionally) suggests the harvesting season is coming.
This image originally appeared as part of Northwestern Scientific Images Contest. The contest and subsequent exhibitions are organized by Science in Society, the University's research center for science education and public engagement. Further information and opportunities to participate are available on their website.
Northwestern Scientific Images Contest
Water, Condensation, Strawberries
Science in Society, DigitalHub. Galter Health Sciences Library & Learning Center
Honorable Mention, This image shows a single cell called a fibroblast. This type of cell is involved in wound healing. Fibroblasts contain flexible filaments made of vimentin, a protein which helps cells change shape and move. Researchers study these filaments and their movement to understand how they work in our cells. The microscopic filaments inside the cell are revealed by staining them with fluorescent dye. This dye glows when exposed to laser light. Then a picture is taken with a special microscope. In this image, thick bundles of filaments appear in bright yellow, while individual filaments at the edge of the cell appear in violet.
This image originally appeared as part of Northwestern's Scientific Images Contest. The contest and subsequent exhibitions are organized by Science in Society, the university's research center for science education and public engagement. Further information and opportunities to participate are available on their website. Prints and canvas editions of these Northwestern research images can also be purchased online (with the small net profit going to science education and outreach programming in the Chicago area).
Walking with Ears: Altered Auditory Feedback Impacts Gait Step Length in Older Adults
Three spreadsheets containing the average (mean) and variability (standard deviation) of the step data, as well as the demographic information, collected across all 20 participants and 6 conditions associated with the study titled "Walking with Ears: Altered Auditory Feedback Impacts Gait Step Length in Older Adults."
Auditory feedback may provide the nervous system with valuable temporal (e.g. footsteps) and spatial (e.g. external reference sounds) information that can assist in the control of upright walking. As such, hearing loss may directly contribute to declines in mobility among older adults. Our purpose was to examine the impact of auditory feedback on walking in older adults. Twenty older adults with no diagnosed hearing loss walked on a treadmill for three sound conditions: Baseline, Ear Plugs, and White Noise. We hypothesized that in response to reduced temporal auditory feedback during the Ear Plugs and White Noise conditions, participants would adapt shorter and faster steps that are traditionally believed to increase mechanical stability. This hypothesis was not supported. Interestingly, we observed increases in step length (p=0.047) and step time (p=0.026) during the Ear Plugs condition versus Baseline. Taking longer steps during the Ear Plugs condition may have increased ground reaction forces, thus allowing participants to sense footsteps via an occlusion effect. As a follow-up, we performed a Pearsons correlation relating the step length increase during the Ear Plugs condition to participants scores on a clinical walking balance test, the Functional Gait Assessment. We found a moderate negative relationship (rho=-0.44, p=0.055) indicating that participants with worse balance made the greatest increases in step length during the Ear Plugs condition. This finding suggests that participants may have actively sought auditory feedback with longer steps, sacrificing a more mechanically stable stepping pattern. We also hypothesized that reduced spatial localization feedback during the Ear Plugs and White Noise conditions would decrease control of center of mass (COM) dynamics, resulting in an increase in lateral COM excursion, lateral margin of stability, and short-term Lyapunov exponent. However, we found no main effects of auditory feedback on these metrics (p=0.580, p=0.896, and p=0.056, respectively). Overall, these results suggest that during a steady-state walking task, healthy older adults can maintain walking control without auditory feedback. However, increases in step length observed during the Ear Plugs condition may indicate that temporal auditory cues provide locomotor feedback that becomes increasingly valuable as balance deteriorates with age.
locomotion, balance, hearing, sound, gait
Cornwell, Tara Itze, Gordon, Keith Edward
DigitalHub. Galter Health Sciences Library & Learning Center