City lights and noise alter bird biorhythms
Noise from traffic and artificial night lighting cause birds in a city center to become active up to five hours earlier in the morning than birds in more natural areas. These were the findings from an investigation conducted on 400 blackbirds in Leipzig, Germany. Scientists from the Helmholtz Centre for Environmental Research reported in the journal PLOS ONE that these findings showed how ambient noise and light pollution caused by humans have significant effects on the behavioral patterns of city blackbirds.
The blackbird, a medium-size thrush, was originally a forest-dweller, but since the early 19th century it has become well-adapted to the conditions of cities, where it is now a common resident that is easily identified by its very distinct birdsong.
“The brighter the night, the earlier the blackbirds started their dawn song,” reports biologist Anja Russ. “We found this linear relationship for low levels of artificial night light but it seemed to reach a threshold. If this threshold is exceeded, an increase in light intensity will not lead to an even earlier onset of dawn song.” Helmholtz Association
Clues on how very first continents formed
New research led by University of Calgary geophysicist David Eaton provides strong evidence against continent formation above a hot mantle plume, similar to an environment that presently exists beneath the Hawaiian Islands.
The analysis, published in Nature Geoscience, indicates that the nuclei of Earth’s continents formed as a byproduct of mountain-building processes, by stacking up slabs of relatively cold oceanic crust. This process created thick, strong “keels” in the Earth’s mantle that supported the overlying crust and enabled continents to form.
The scientific clues leading to this conclusion were derived from computer simulations of the slow cooling process of continents, combined with analysis of the distribution of diamonds in the deep Earth. Eaton developed computer software to enable numerical simulation of the slow diffusive cooling of Earth’s mantle over a time span of billions of years. University of Calgary
Smartphones used to diagnose eye disease
Retinal photography is an essential part of any ophthalmology practice. But specialized cameras can cost hundreds of thousands of dollars, making the technology out of reach for smaller ophthalmic practices and to physicians in third-world countries. But in a recent study, Massachusetts Eye and Ear researchers describe the relatively simple technique of retinal photography in human and rabbit eyes using a smartphone, an inexpensive app for it, and instruments that are readily available in an ophthalmic practice.
“Our technique provides a simpler and higher quality method to more consistently produce excellent images of a patient’s fundus,” said senior author Shizuo Mukai, M.D., a Massachusetts Eye and Ear retina specialist and Harvard Medical School associate professor of ophthalmology. “This technique has been extremely helpful for us in the emergency department setting, in-patient consultations, and during examinations under anesthesia as it provides a cheaper and portable option for high-quality fundus-image acquisition for documentation and consultation. This technique is well tolerated in awake patients most likely since the light intensity used is often well below that which is used in standard indirect ophthalmoscopy.” Journal of Opthalmology
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