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Repairable Cascaded Slide-lock System Endows Bird Feathers with Tear-resistance and Superdurability

Penelitian - Researchers reveal the superdurability of bird feathers arises from their repairable cascaded slide-lock system, which is composed of hooklets, a slide rail, and spines at the end of the slide rail as terminating structures.

After a long or tumultuous flight through bushes, birds are often found preening their disordered feathers with their bill, which is considered to repair separated feather vanes. The fascinating structural features are closely related to the evolution, courtship, and taxonomy of birds and the unique optical and mechanical properties of feathers, which have attracted tremendous attention over the past centuries.

Since Hooke drafted the first rough model of feather structures in 1665, many efforts have been made to explore the structure and function of feathers. Microscale hooks and grooves and their functions have been observed and illustrated with optical and electron microscopy.

Unfortunately, to date, the superdurability of feathers against tears ha…

Chinese scientists call for cooperation against asteroid threat

Penelitian - Chinese scientists have appealed to further strengthen international cooperation in space exploration, aiming to reduce the risk of near-Earth objects. Noting that modern space technologies are capable of defending Earth from threat.

Compared to global issues like food security, energy shortage, climate change, cyber attacks and environmental pollution caused by human activities, more serious threats to our globe may come from space, said Chen Jiansheng, a senior astronomer of the Chinese Academy of Sciences (CAS).

There are more than 18,000 near-Earth asteroids around 800 have a diameter greater than 1 km. Researchers have discovered 180 giant impact craters on our planet, which exhibit the formidable power that a small celestial object could generate when hitting the Earth.

Evidence found in the strata in Kamba County, southwest China's Tibet Autonomous Region, showed that Earth suffered a major asteroid impact about 65 million years ago, which might have led to the…

Standing Enokitake-like Nanowire Films for Highly Stretchable Elastronics

Penelitian - Monash University team show standing enokitake-like gold-nanowire-based films chemically bonded to an elastomer can be stretched up to 900% and are highly durable, with more than 93% conductivity recovery even after 2000 stretching cycles to 800% strain.

Electronics are transitioning from the current rigid version to a next-generation flexible design, which will ultimately evolve into stretchable electronics. In an elastronic system, its components can be seamlessly integrated with skin to become parts of our organs, thereby enabling genuine biodiagnostics in real time and in situ.

It is well-known that elastronics require a seamless combination of stretchability and electrical conductivity, which can be achieved extrinsically or intrinsically. The former is achieved by designing structures that stretch, whereas the latter is realized by producing materials that are deformable.

An ideal elastronic system may be made from intrinsically elastic components, including conduct…

Mathematician Michael Atiyah Claims a Simple Proof for Riemann Hypothesis

Penelitian - British mathematician Michael Atiyah claims that he has a "simple proof" for the Riemann hypothesis, which has been one of the greatest challenges in math since German mathematician Bernhard Riemann brought it out in 1859.

According to a tweet posted by the Heidelberg Laureate Forum, a networking event for mathematicians and computer scientists from all the world, the British-Lebanese mathematician will address the forum on Sept. 24 and show the world his proof of the hypothesis.

"Will he (be) presenting a proof of the Riemann Hypothesis? Yes, that is what his abstract says," read the tweet.

The Riemann hypothesis is modern math's holy grail. Although it is almost incomprehensible for people without intensive math training, it describes the distribution of prime numbers among positive integers.

Prime numbers, very simple by definition, are the building blocks of modern mathematics, especially number theory. Achievements in prime number theory have …

Ancient Steroids Establish the Ediacaran Fossil Dickinsonia as One of the Earliest Animals

Penelitian - The Australian National University (ANU) scientists have discovered molecules of fat in an ancient fossil to reveal the earliest confirmed animal in the geological record lived on Earth 558 million years ago.

The strange creature called Dickinsonia, which grew up to 1.4 metres in length and was oval shaped with rib-like segments running along its body, was part of the Ediacara Biota that lived on Earth 20 million years prior to the 'Cambrian explosion' of modern animal life.

Ilya Bobrovskiy discovered a Dickinsonia fossil so well preserved in a remote area near the White Sea in the northwest of Russia that the tissue still contained molecules of cholesterol, a type of fat that is the hallmark of animal life.

The 'Cambrian explosion' was when complex animals and other macroscopic organisms, such as molluscs, worms, arthropods and sponges -- began to dominate the fossil record.

"The fossil fat molecules that we've found prove that animals were large…

Food Preferences of Similarly Raised and Kept Captive Dogs and Wolves

Penelitian - The evolution of food preferences may be driven by the habitat a species has evolved in, energetic and protein requirements, and resource distribution. Several predators have been shown to prefer protein rich foods in accordance with their carnivorous feeding niches.

While dogs are capable of hunting, they are primarily solitary scavengers that thrive around human settlements and feed predominantly and indiscriminately on human refuse. The different socio-ecologies of dogs and wolves is postulated to have shaped the way they approach both social and independent problem-solving tasks.

For instance, in line with wolves’ dependence on cooperation in both hunting and pup-rearing, wolves outperformed dogs in a cooperative string-pulling task and showed more food sharing than dogs.

Akshay Rao of the University of Veterinary Medicine in Vienna and team tested similarly raised and kept dogs and wolves in two different food choice tasks, a classic two-choice task and a multiple-ch…

Kinetics of the Invasion and Egress Processes of Babesia divergens, Observed by Time-lapse Video Microscopy

Penelitian - Babesia divergens is an apicomplexan protozoan parasite that is naturally transmitted by ixodid ticks. The cases are concentrated in Europe where the intraerythrocytic parasite is considered highly pathogenic to cattle in which it causes babesiosis commonly known as redwater.

This parasite also causes severe babesiosis in humans, occurring as a fulminant infection. B. divergens infections are therefore considered medical emergencies and patients require immediate treatment. Once the host has been bitten by an infected tick, B. divergens sporozoites invade the erythrocytes and the asexual cycle of the parasite then commences.

The asexual multiplication is asynchronous and parasites multiply in erythrocytes by binary fission, resulting in a considerably complex pleomorphic process. Recently, it has been possible to elucidate a temporal and coordinated proliferative cycle in vitro over 24 hours.

Estrella Montero of the Instituto de Salud Carlos III in Madrid and team present…

Habitual Tool Use Innovated by Free-living New Zealand Kea

Penelitian - The question of why flexible tool use is rare in the animal kingdom is important given the evolutionary significance of the behaviour in human evolution. Researchers have found that world's only alpine parrot, the kea in the South Island's Murchison Mountains is using sticks to get food out of stoat trap boxes.

The emergence of flexible tool use is rare in the animal kingdom and thought to be largely constrained by either cognitive ability or ecological factors. That mostly birds with a high level of intelligence innovate tool use in captivity is consistent with the former hypothesis.

Matthew Goodman, Thomas Hayward and Gavin Hunt report the first documented case of habitual tool use innovated in the wild by a bird species only known to have used tools in captivity. Trap-boxes containing food-bait and snap-traps were installed in the remote Murchison Mountains, New Zealand, from 2002 to catch introduced stoats.

Kea tampered with the trap-boxes in various ways. Vid…

A Tailless Aerial Robotic Flapper Reveals that Flies Use Torque Coupling in Rapid Banked Turns

Penelitian - Dutch engineers developed a novel insect-inspired flying-wing robot, whose exceptional flight qualities can open up new drone applications.

The study published on Thursday in the Science described the lightweight flying robot that powered and controlled flight by flapping wings like flies, thus allowing it not only to hover on the spot and fly in any direction but also be very agile.

As in flying insects, the robot's flapping wings, beating 17 times per second, not only generated the lift force needed to stay airborne but also control the flight via minor adjustments in the wing motion.

"The robot has a top speed of 25 km/h and can even perform aggressive maneuvers, such as 360-degree flips, resembling loops and barrel rolls," said Matej Karasek of the Delft University of Technology in Netherlands.

"Moreover, the 33 cm wingspan and 29 gram robot has, for its size, excellent power efficiency, allowing 5 minutes of hovering flight or more than a 1 km flig…