Otters cavorting in the water is a scene with which we’re all familiar. Yet, unlike many other mammals that spend a considerable amount of time in the water–polar bears, seals, dolphins, and whales–river otters do not have a thick layer of body fat to keep warm. They rely, instead, on a few unique adaptations; namely, their fur and the densely packed layer of specially adapted underhairs.
Using scanning electron microscopy and polarizing light microsopy, John W. Weisel, PhD, Professor of Cell and Developmental Biology at the University of Pennsylvania School of Medicine, and colleagues, examined the structure of these hairs for clues to their exceptional insulation abilities. (Click on the thumbnail to view full-size images). They found that the cuticle surface structure of the underhairs and base of the less-abundant guard hairs are distinctively shaped to interlock, with wedge-shaped fins or petals fitting into wedge-shaped grooves between fins of adjacent hairs. Weisel and colleagues report their findings in the Canadian Journal of Zoology.
Weisel and Research Specialist Chandrasekaran Nagaswami, MD, also in Penn’s Department of Cell and Developmental Biology, usually work on defining the physical properties of blood clots and applying this knowledge to find better treatments for heart disease. Two years ago when Weisel, an avid hiker, climber, and white-water kayaker, took a month of his sabbatical year to study wolves–a life-long interest–on Isle Royale National Park in Lake Superior, Michigan, he also collected hair samples from the island’s mammals—including wolves, moose, and otters. (The ecological studies of wolves and moose on Isle Royale, which started in 1959, are part of the longest-running animal ecology study in the world. Isle Royale has been a training ground for many ecologists, and lessons learned here have been applied to the re-introduction of wolves to Yellowstone National Park.)
Karen Kreeger | EurekAlert!
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...
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22.09.2017 | Physics and Astronomy