An international team of researchers from San Diego State University, UC San Diego, and the Kolmården Zoo in Sweden has developed an approach that integrates advanced computing, X-ray CT scanners, and modern computational methods that give a 3D simulated look inside the head of a Cuvier’s beaked whale.
“Our numerical analysis software can be used to conduct basic research into the mechanism of sound production and hearing in these whales, simulate exposure at sound pressure levels that would be impossible on live animals, or assess various mitigation strategies,” said Petr Krysl, a UC San Diego structural engineering professor who developed the computational methods for this research. “We believe that our research can enable us to understand, and eventually reduce, the potential negative effects of high intensity sound on marine organisms.”
The results of this research were recently published in a PLoS ONE article entitled, “A New Acoustic Portal into the Odontocete Ear and Vibrational Analysis of the Tympanoperiotic Complex” by Krysl, Ted W. Cranford, an adjunct professor of research in biology at San Diego State University; and Mats Amundin, a researcher at Sweden’s Kolmården Zoo. Sponsors of the research include the office of the Chief of Naval Operations (CNO), Environmental Readiness Division.
The model the researchers have developed creates a 3-dimensional virtual environment in which they can simulate sounds propagated through the virtual specimen and reveal the interactions between the sound and the anatomy. By having a virtual “peek” inside the whale’s head, the scientists are able to better understand and see how sound may impact or potentially harm marine life.
“Humans introduce considerable amounts of sound and noise into the oceans of the world,” Krysl said. “Many marine organisms make acute use of sound for their primary sensory modality because light penetrates so poorly into water. The primary focus of our work is Cuvier's beaked whale because some have stranded and died in the presence of Navy sonar. The discoveries we made with regard to the mechanisms of hearing in the beaked whale also apply to the bottlenose dolphin and, we suspect, to all types of toothed whales and perhaps other marine mammals.”
Krysl and his colleagues have been studying the effects sound has on marine life for the past nine years.
“This research program has a very strong experimental component, which has successfully generated digital models of the anatomy of a beaked whale, and has identified mechanical parameters of the biological tissues in the organs of a beaked whale,” Krysl said. “We are continuing our current line of research on the beaked whale and conducting validation experiments with the bottlenose dolphin. We plan additional modeling refinements that will allow us to investigate the entire sound pathway from the sea water to the entrance to the cochlea. These projects address several primary objectives in the Navy’s plan to understand demographics, acoustic exposure thresholds, and mitigation strategies for living marine resources.”
The area of research that deals with noise in the ocean has indeed been growing rapidly with concerns over the rising levels of ocean noise resulting from shipping, petroleum exploration and production, and military exercises, Krysl said.
“We have recently seen that other researchers are adopting our methodology for analyzing the impact of sound on marine mammals, although we are currently the only group producing significant results,” he said. “This project significantly advances our knowledge of the basic biology of marine mammals. Hearing is an essential sensory ability for life under water – sound is used for hunting, navigating, and social interaction. The applied significance of our research has to do with the Navy’s need to use sonar. Consequently, the Navy needs to be able to answer questions such as, ‘Is sonar safe to use and under what conditions?’ and ‘Can we minimize the impact on marine life and how?’ This is not possible without a basic understanding of biology and acoustics of the ocean inhabitants.”
Andrea Siedsma | EurekAlert!
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
Graphene is up to the job
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
26.09.2017 | Life Sciences
26.09.2017 | Physics and Astronomy
26.09.2017 | Information Technology