When Engineers Are Bored.

ALL ROLLED UP

A newly identified mineral christened merelaniite tightly rolls up like a scroll as it crystallizes, forming shiny dark gray needles up to a few millimeters in length (Minerals 2016, DOI: 10.3390/min6040115). The overall formula of the mineral is Mo₄Pb₄VSbS₁₅. It crystallizes into a sheet composed primarily of alternating ultrathin layers of MoS₂ and PbS. “It’s like a natural nanocomposite,” says research team leader John A. Jaszczak of Michigan Technological University. Strain from the interacting layers likely causes the crystalline sheets to wrap around themselves as they grow. Jaszczak and coworkers named the mineral for the Merelani mining district in Tanzania, where the merelaniite samples originated. Collaborating research institutions included the U.K. Natural History Museum, U.S. National Museum of Natural History, and University of Florence.

Credit: Minerals (both)

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from the Fresh Paleomemes fb group

The Scorpii AR system

In the system AR Scorpii a rapidly spinning white dwarf star powers electrons up to almost the speed of light. These high energy particles release blasts of radiation that lash the companion red dwarf star, and cause the entire system to pulse dramatically every 1.97 minutes with radiation ranging from the ultraviolet to radio.

The star system AR Scorpii, or AR Sco for short, lies in the constellation of Scorpius, 380 light-years from Earth. It comprises a rapidly spinning white dwarf, the size of Earth but containing 200,000 times more mass, and a cool red dwarf companion one third the mass of the Sun, orbiting one another every 3.6 hours in a cosmic dance as regular as clockwork.

Read more at: cosmosmagazine / astronomynow

This is the chemical formula for love: C8H11NO2+C10H12N2O+C43H66N12O12S2 dopamine, seratonin, oxytocin. It can be easily manufactured in a lab, but overdosing on any of them can cause schizophrenia, extreme paranoia, and insanity. Let that sink in.

(via mrzim)

Antarctic sponges live on a time scale we can barely comprehend. 

Yahoo!

Glutamate, an essential food for the brain

Glutamate is an amino acid with very different functions: in the pancreas, it modulates the activity of the pancreatic ß-cells responsible for insulin production, whereas in the brain it is the main excitatory neurotransmitter. In recent years, it has been suspected to play an additional role in the functioning of the brain. By discovering how the brain uses glutamate to produce energy, researchers at the University of Geneva (UNIGE) confirm this hypothesis and highlight unexpected links with the rest of the body. To read in Cell Reports.

Unlike other organs, the brain cannot draw its energy from lipids, an energy resource widely present in the body. The blood-brain barrier, which protects it from the pathogens and toxins circulating in the blood, indeed limits the passage of these lipids. Moreover, while most of the organs in the human body have the ability to store glucose by increasing their mass, the brain, prisoner of the cranial bones, cannot count on these variations in volume. Unable to store its food, it depends on sugar supplied in real-time by the rest of the body. This distribution of energy is controlled by the liver.

Pierre Maechler, professor at the Faculty of Medicine at UNIGE, and his team therefore decided to verify if glutamate was indeed an energy source for the brain. To do so, the researchers analyzed the role of the glutamate dehydrogenase enzyme in the brain. In mutant form, this enzyme, encoded by the Glud1 gene, is responsible for a congenital hyperinsulinism syndrome, a severe disease affecting at the same time the endocrine pancreas, the liver and the brain. Individuals affected by this syndrome suffer from intellectual disability and have a high risk of epilepsy. “We have suppressed the Glud1 gene in the brain of mice. In the absence of glutamate dehydrogenase, we observed that the brain was no longer able to convert glutamate into energy, even though the amino acid was present in the brain,” explains Melis Karaca, first author of this study.

Priority to the brain

Devoid of the energy supplied by cerebral glutamate, the brain sends signals to the liver to requisition a compensatory proportion of glucose, at the expense of the rest of the body. This is why the transgenic mice also showed a growth deficit and muscle atrophy. “This clearly shows how the brain works in a just-in-time manner and that each percent of energy resources is essential for its proper functioning,” highlights Professor Pierre Maechler. “If a part of this energy disappears, the brain serves itself first and the rest of the body suffers. The liver must then make more glucose by drawing upon muscle protein, resulting in loss of muscle mass. Knowing that the brain uses glutamate as an energy resource allows us to reflect on other ways to overcome a potential shortfall. ”

Scientists also suspect a correlation between the Glud1 gene and some neurodevelopmental disorders, particularly epilepsy and schizophrenia. They are currently pursuing their research by introducing in mice the same Glud1 mutation detected in epileptic patients. At the same time, another group is working with schizophrenic patients to assess the way their brain uses glutamate.

Have you ever seen a Lybia crab? Often called boxer crabs, or pom-pom crabs, these tiny crustaceans are easily identified by a unique behavior: they hold anemones on their claws to defend themselves from predators, keeping the anemones small enough to wield by limiting their food intake. But how do they get the anemones in the first place? Researchers think they have an answer: by stealing one from another crab, and then splitting it in half to create two identical clones—one for each claw.

Two graduate students, Yisrael Schnytzer and Yaniv Giman, set out to discover how the Lybia crabs acquire their anemones. They spent years observing and collecting crabs (Lybia leptochelis, specifically) from the Red Sea. Given that Lybia crabs are exceptionally well-camouflaged and only a few centimeters across, this was no easy task, but they managed to observe or collect more than 100 individuals.

Every specimen Schnytzer and Giman found was in possession of a pair of anemones, and each anemone belonged to the genus Alicia. Interestingly, the anemones themselves were not found living by themselves; they were only found already living on the claws of Lybia crabs. The researchers decided to study some of the crabs in a laboratory, to see if more observation would solve the mystery of how they acquired their anemones to begin with.

In the lab, the researchers conducted several experiments, the first of which was to take one anemone away from a crab. When left with just one anemone, the crab solved the problem by splitting the remaining anemone into two. The two halves of the anemone would then regenerate into two identical clones, one for each claw, over the course of several days.

The second experiment involved removing both anemones from one crab and placing it in a tank with a crab that still had both its anemones. The result: the two crabs would fight, with the anemone-less crab usually succeeding in stealing one anemone from the other crab. These fights did not tend to result in injuries to the crabs themselves, and once each crab was in possession of one anemone, both crabs would split their anemone into halves to create a pair of clones.

In addition to these experiments, Schnytzer and Giman examined the genes of the anemones found on the wild crabs. Every crab collected from the wild was holding a pair of identical clones. This might mean that anemone theft is rampant among Lybia crabs in the Red Sea, and that it might be the main way that these crabs acquire their anemones.

At any rate, it is clear that the crabs are frequently splitting anemones in two, inducing asexual reproduction in another species and potentially limiting that species’ genetic diversity in the process—a rarity outside the human world.

Based on materials provided by PeerJ and ScienceDaily

Journal reference: Yisrael Schnytzer, Yaniv Giman, Ilan Karplus, Yair Achituv. Boxer crabs induce asexual reproduction of their associated sea anemones by splitting and intraspecific theft. PeerJ, 2017; 5: e2954 DOI: 10.7717/peerj.2954

Image credit: Yisrael Schnytzer

Submitted by volk-morya

Oh hey, not a big deal, but the hubble took a picture of a star that’s nearing supernova status