The mathematics of how sperm swim

A better understanding how a sperm swims its way toward an egg could help inform new treatments for male infertility. Researchers from the University of York have now come up with a mathematical formula to model how large numbers of moving sperm interact with fluid they're swimming through. From the University:

By analysing the head and tail movements of the sperm, researchers have now shown that the sperm moves the fluid in a coordinated rhythmic way, which can be captured to form a relatively simple mathematical formula. This means complex and expensive computer simulations are no longer needed to understand how the fluid moves as the sperm swim.

The research demonstrated that the sperm has to make multiple contradictory movements, such as moving backwards, in order to propel it forward towards the egg.

The whip-like tail of the sperm has a particular rhythm that pulls the head backwards and sideways to create a jerky fluid flow, countering some of the intense friction that is created due to their diminutive sizes.

“It is true when scientists say how miraculous it is that a sperm ever reaches an egg, but the human body has a very sophisticated system of making sure the right cells come together," (says University of York mathematician Hermes Gadêlha.)

“You would assume that the jerky movements of the sperm would have a very random impact on the fluid flow around it, making it even more difficult for competing sperm cells to navigate through it, but in fact you see well defined patterns forming in the fluid around the sperm.

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Public entomologists struggle with an epidemic of delusional parasitosis

Dr Gale Ridge is a public entomologist at the Connecticut Agricultural Experiment Station, where an average of 23 people a day call, write or visit; an increasing proportion of them aren't inquiring about actual insects, they're suffering from delusional parasitosis, and they're desperate and even suicidal. Read the rest

Watch researchers modify caterpillars, revealing wing development inside cocoons

Biologist Nipam Patel and his team at UC Berkeley study how butterflies develop wing shape and color by performing surgery on caterpillars, creating translucent windows in their cocoons. Read the rest

The Carbon Bubble is about to pop

Despite Trump's denial of climate change the the ghastly attacks on climate science and mitigation in the new proposed budget, the Carbon Bubble -- which overprices hydrocarbons and the industries that rely on them, as though we'll be burning all of them with impunity -- is about to pop. Read the rest

Fancy flashlight finds first fluorescent frog

South American polka dot tree frogs are pretty cool, but Julián Faivovich and Carlos Taboada found out they are even cooler when an ultraviolet flashlight is trained on them. They fluoresce.

Many animals can see beyond the spectrum visible to humans, and these frogs adapted with this trait. From the abstract:

Fluorescence, the absorption of short-wavelength electromagnetic radiation reemitted at longer wavelengths, has been suggested to play several biological roles in metazoans. This phenomenon is uncommon in tetrapods, being restricted mostly to parrots and marine turtles. We report fluorescence in amphibians, in the tree frog Hypsiboas punctatus, showing that fluorescence in living frogs is produced by a combination of lymph and glandular emission, with pigmentary cell filtering in the skin. The chemical origin of fluorescence was traced to a class of fluorescent compounds derived from, here named hyloins. We show that fluorescence contributes 18−29% of the total emerging light under twilight and nocturnal scenarios, largely enhancing brightness of the individuals and matching the sensitivity of night vision in amphibians. These results introduce an unprecedented source of pigmentation in amphibians and highlight the potential relevance of fluorescence in visual perception in terrestrial environments.

I'd make a Wikipedia article about dihydroisoquinolinone, but it would probably be an annoying and demoralizing fight.

Naturally occurring fluorescence in frogs (via Nature) Read the rest

Examining the ancient technique of "memory palaces" with brain-imaging

A small (51 men aged 24 +/- 3 years) study published in Neuron tasked experimental subjects with practicing the ancient Greek mnemonic technique of "memory palaces" and then scanned their brains with functional magnetic resonance imaging, comparing the scans to scans from competitive "memory athletes" and also measuring their performance on memorization tasks. Read the rest

These may be the oldest remains of life on Earth ever found

These eyelash-sized bits of minerals found in rock from northern Quebec may be the oldest traces of life ever found. The tubes of hematite are 4.28 billion years old, beating out 3.7 billion year old microbial remains found in Greenland. Nadia Drake tells the story at National Geographic:

The microfossils also lend support to the idea that the warm, watery, mineral-rich neighborhoods around submerged vents are prime places for life to emerge, whether on this planet, on the seafloors of icy moons, or elsewhere in the universe....

“If indeed their analyses and interpretations are correct, then life arose rapidly on Earth, soon after the planet itself began to stabilize,” says astrobiologist Kevin Hand of NASA’s Jet Propulsion Laboratory. “As the froth of geology began to cool, biology established its role as a planetary process.”

But while the fossils are clad in iron, they might not be iron-clad evidence of ancient life. Some scientists doubt that they are the remains of microbes at all. Others note that the age of the crystals cradling the potential microfossils is controversial, and the structures may be more than a billion years younger than reported.

"This May Be the Oldest Known Sign of Life on Earth" by Nadia Drake (Nat Geo) Read the rest

Explaining physics with wonderful, 1930s-style animation

Hugh writes, "These amazing animated shorts on physics feature an adorable, 1930's style version of Maxwell's Demon. There are 3 so far -- can't wait to see more!" Read the rest

How to solve the artificial intelligence "stop button" problem

Implementing an on/off switch on a general artificial intelligence is way more complicated than it sounds. Rob Miles of Computerphile looks at what could go wrong. Hint: lots. Read the rest

Nominations open for $250,000 MIT Media Lab prize for Disobedient Research

Last summer, the MIT Media Lab announced its $250,000 prize for Disobedient Research, and now the nominations process has launched. Read the rest

Superbugs are being fuelled by imaginary penicillin allergies

Lots of people think they're allergic to penicillin, but aren't -- so when they have infections, doctors are obliged to skip the front-line drugs, which accelerates the pace of antibiotic resistance in common bacteria. Read the rest

Brain activity recorded as much as 10 minutes after death

University of Western Ontario researchers examined the electrical activity in several patients before and after their life support was turned off and they were declared clinically dead, when the heart had stopped beating. In one patient, brain waves, in the form of single delta wave bursts, continued for minutes after death.

"It is difficult to posit a physiological basis for this EEG activity given that it occurs after a prolonged loss of circulation," the researchers write in their scientific paper. "These waveform bursts could, therefore, be artefactual in nature, although an artefactual source could not be identified."

This kind of research in the niche field of necroneuroscience is relevant to ethical discussions around organ donation and how the moment of death is defined.

(Neuroskeptic via Daily Grail)

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You can hear the difference between hot and cold water

Water is viscous. With heat, the viscosity drops. And you can hear the difference in its splash.

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Lego announces "Women of NASA" minifigs

Last year, MIT News editor Maya Weinstock submitted her Women of NASA minifigures design to LEGO Ideas. LEGO has just approved the idea and laster this year or early 2018 will release an official minifig set of these five inspiring women in science:

Margaret Hamilton, computer scientist: While working at MIT under contract with NASA in the 1960s, Hamilton developed the on-board flight software for the Apollo missions to the moon. She is known for popularizing the modern concept of software.

Katherine Johnson, mathematician and space scientist: A longtime NASA researcher, Johnson is best known for calculating and verifying trajectories for the Mercury and Apollo programs — including the Apollo 11 mission that first landed humans on the moon.

Sally Ride, astronaut, physicist, and educator: A physicist by training, Ride became the first American woman in space in 1983. After retiring as a NASA astronaut, she founded an educational company focusing on encouraging children — especially girls — to pursue the sciences.

Nancy Grace Roman, astronomer: One of the first female executives at NASA, Roman is known to many as the "Mother of Hubble" for her role in planning the Hubble Space Telescope. She also developed NASA's astronomy research program.

Mae Jemison, astronaut, physician, and entrepreneur: Trained as a medical doctor, Jemison became the first African-American woman in space in 1992. After retiring from NASA, Jemison established a company that develops new technologies and encourages students in the sciences.

(via Laughing Squid) Read the rest

Psychology journal editor asked to resign for refusing to review papers unless he can see the data

Psychologist Gert Storms doesn't want to review scientific papers if their authors refuse to share with him the underlying data. The American Psychological Association (APA), which publishes the journal he edits, has asked him to resign.

Nature.com's Gautam Naik reports that the effort to force him out is a test of The Peer Reviewer's Opennness Initiative, a move crafted to "increase transparency in a field beset by reports of fraud and dubious research."

Storms, a psychologist at the Catholic University of Leuven in Belgium and a consulting editor for the APA’s Journal of Experimental Psychology: Learning, Memory, and Cognition, accepted an invitation last year to review a study for the journal, and pointed out his new open-data policy. The journal's editor, Robert Greene, wrote back to say that Storms’s stance set “a terrible precedent” because it was unfair to the author of the paper and opposed the APA’s policies and the guidelines followed by other reviewers. “Given that your policy conflicts with that of the journal, I think that it's best that you step down from the editorial board,” he wrote.

Storms refused, writing that he would continue to do what he thought was necessary to “prevent sloppy science”. And he forwarded his correspondence to other editors at the journal. Two of them, Robert Hartsuiker and Marc Brysbaert, both psychologists at Ghent University in Belgium, wrote to Greene saying that they, too, would quit if Storms was forced to resign. "The policy of asking people to leave rather than inviting a discussion and getting critical voices — I found that quite inappropriate," said Hartsuiker.

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The mystery of the Tully Monster continues

In 1958 in an Illinois creek bed, an amateur fossil collector named Francis Tully discovered the fossilized remains of a bizarre creature that resembled a mollusk, insect, and worm yet was none of those things. Since then, thousands of 300 million-year-old fossilized "Tully Monsters" have turned up and the creature was officially named as the Illinois state fossil.

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Frog saliva is even stranger than scientists expected

Frog tongue mechanism has been well-documented, but only recently have scientists started looking at the remarkable combo of tongue softness and frog spit's chemical makeup. Read the rest

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