“The beam projections have different frequencies and can be sent in different directions. The advantage is probably that the dolphin can locate the object more precisely”, says Josefin Starkhammar, a newly examined doctor in Electrical Measurements at Lund University, who also holds a Master’s degree in Engineering Physics.
The study, which was carried out together with scientists from San Diego, was published in the latest issue of the journal Biology Letters. The co-authors of the article were Patrick W. Moore, Lois Talmadge and Dorian S. Houser, who work at the National Marine Mammal Foundation in the USA.
“The findings add fuel to an already fierce debate in the research community on how the echolocation sound is produced”, says Josefin Starkhammar.
Dr Starkhammar’s own guess is that the two sound projections come from the two different sound-producing organs, the existence of which is well known, but it was believed that only one was active during echolocation. She stresses that more research is needed. For example, the two projections could also be explained by complicated reflections in the head of the dolphin, where the sound is formed.
“It is also somewhat remarkable that this has only been discovered now. Research has been carried out on dolphins and echolocation since the 1960s”, says Josefin Starkhammar.One explanation as to why the discovery has taken so long is that this research requires recently developed and quite advanced measuring equipment and signal processing techniques. In addition, until now it has mostly been biologists who have conducted research on dolphins, and their expertise is often not in this specific area of technology. Furthermore, the research requires dolphins trained to answer scientific questions! The combination of marine biologists and engineers is ideal, in Josefin Starkhammar’s view.
To help her she has developed a device with 47 hydrophones (microphones for use in water).
“It is currently one of the best devices in the world for capturing dolphins’ ultrasound in water”, says Josefin Starkhammar, who has spent a lot of time testing and developing the equipment, including at Kolmården Wildlife Park, where one of her supervisors works. There she has also conducted other studies on dolphins and their echolocation.
Bats also use echolocation and there are a few species of shrew and some cave-dwelling birds which use a simpler form of the method. Even humans have developed devices that use echolocation and ultrasound technology.
“However, dolphins’ echolocation is in many ways much more sophisticated. Evolution has had the possibility to hone it over millions of years. Therefore, we humans have a lot to learn from dolphins. What is more, the knowledge could be important in finding ways to protect dolphins, for example from noise disturbance”, says Josefin Starkhammar.
For more information, please contact Josefin Starkhammar on firstname.lastname@example.org or +46 706 171215.
Megan Grindlay | idw
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
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...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy