#scied

[sarahmackattack]

Alright people. I need your help. Enrollment for Skype a scientist this semester has been -fine- but we can do better. We have so many scientists who want to speak with classrooms! Will you tell a teacher you know about our program 🥺 please?

Send them to skypeascientist.com/sign-up

[sciencenewsforstudents]

Ancient recipes helped scientists resurrect a long-lost blue hue | Science News for Students

Led by medieval texts, scientists hunted down a plant and used its fruit to make a blue watercolor with mysterious origins.

Scientists have resurrected a purple-blue hue that had been lost to time.

Called folium, this watercolor had been used to paint images on the pages of medieval manuscripts. But long ago, it fell out of use. Now scientists have tracked down folium’s source to a plant. They’ve also mapped out the molecule that produces its blue hue.

Such chemical information can be key to conserving art. “We want to mimic these ancient colors to know how to … preserve them,” explains Maria Melo. She works at Universidade Nova de Lisboa in Caparica, Portugal. There she studies ancient art and how to preserve or restore it. To unmask folium’s identity, her team had to first find out where it came from.

The pigment hadn’t been used for centuries. Everyone who knew how to prepare it had died long ago. So the researchers turned to books from the 1400’s and found one that described the plant that was its source. That led them on a scavenger hunt to find living specimens of this plant.

The Middle Ages lasted from roughly A.D. 500 to 1500. During that time, a blue watercolor was popular for illustrating texts such as this 15th century prayer book. At long last, researchers have tracked down the color’s source. PALÁCIO NACIONAL DE MAFRA COLLECTION

They enlisted the help of a botanist, a scientist who studies plants. The team landed on Chrozophora tinctoria (Croh-ZOFF-or-uh Tink-TOR-ee-uh). They found this tiny herb with silvery-green leaves in a village in south Portugal. It was growing along roadsides and in fields after harvest. The team gathered its pebble-sized fruit with care.

Back in the lab, the scientists extracted the pigment with the help of a medieval text on colors. “It’s very specific,” notes Paula Nabais. She’s a conservation scientist who was part of the research team. “So we were able to use that recipe [and] reproduce it.” Nabais also works at Universidade Nova de Lisboa.

“That’s pretty cool to have done that work of looking in the historical recipes and traveling back in time,” says Francesca Casadio. She’s a chemist and museum scientist at the Art Institute of Chicago in Illinois. Casadio, who was not part of this study, says the new work is a good example of what’s called experimental archaeology. It recreates an ancient process. By making the dye, the scientists could study its chemistry without experimenting on priceless works of art, she points out.

[sarahmackattack]

How I feel promoting my free program to match scientists with classrooms for Q&A sessions

Many teachers have been working in overdrive for months (or years), so I can understand they might not have the energy to proverbially text back, but I still gotta tell 'em about Skype a Scientist. We're a nonprofit science education org that matches teachers and librarians with scientists for free Q&As about science.

In these sessions, you can:

Learn about the scientists' areas of expertise

Show your class what a real lab looks like

Talk about the many ways a career in science can take shape.

A 4th thing I haven't thought of yet

Here's how it works:

Step 1: Pick a category of science that your class would like to talk about

Step 2: Sign up on SkypeAScientist.com

Step 3: Get a match via email

Step 4: Connect with your scientist to discuss your classroom's interests and needs

Step 5: Talk about science in your classroom (on whatever platform you like, it does not have to be Skype).

[sciencenewsforstudents]

Yes, cats know their own names | Science News for Students

Cats can tell their names apart from other spoken words. A new study supports what cat owners the world over had suspected.

Move over Fido. Dogs aren’t the only pets that can take a hint from humans. Cats can tell the difference between the sound of their names and other similar words, a new study finds. Good kitties.

Scientists have already studied how dogs respond to people’s behavior and speech. But researchers are just scratching the surface of human-cat interactions. Domestic cats (Felis catus) do appear to respond to the expressions on people’s faces. Cats can also distinguish between different human voices. But can cats recognize their own names?

I think many cat owners feel that cats know their names, or the word ‘food,’” says Atsuko Saito. But there was no scientific evidence to back up cat lovers’ hunches. Saito is a psychologist — someone who studies the mind — at Sophia University in Tokyo. She’s also a cat owner to a male mouser named “Okara,” which means soy fiber or tofu scraps in Japanese.

So Saito and her colleagues pounced on that research question. They asked the owners of 77 cats to say four nouns of similar length followed by the cat’s name. Cats gradually lost interest with each random noun. But when the owner said a cat’s name, the feline reacted strongly. They moved their ears, head or tail, shifted their hind paw position. And, of course, they meowed.  

The results were similar when cats lived alone or with other cats. Even cats at a cat café — where customers can hang out with many cats — responded to their names. The name didn’t have to come from a beloved owner, either. When a non-owner said the name, cats still responded to their names more than to other nouns. The scientists published their findings April 4, 2019 in Scientific Reports.

One finding did give the team pause. Cats living at cat cafés almost always reacted to their names and those of other cats living there. Housecats did so much less often. Maybe that’s because cat cafés have so many cats in residence, the researchers speculate. Cats at these café’s don’t just bond with a single owner or a family. Lots of humans visit the cafés, so the cats hear their names from many unfamiliar and familiar voices. A cat living at a café may also frequently hear its name called at the same time as another cat’s. So it may be harder for cats to associate their own names with positive events (such as attention and treats) in these environments. For their next step, the researchers hope to figure out whether cats recognize the names of their feline housemates as well as their own names

These findings mean that cats join the ranks of animals that have shown some sort of response in experiments to the names people give them. Those animals include dogs, dolphins, apes and parrots. It’s hard to compare across species, though. Some dogs, for example, can tell the difference between hundreds of human words (not that it’s a contest or anything). But dog studies usually involve command and fetch tests. Cats might respond to their names, but not many cats can be bothered to fetch.  

The study makes a strong case that cats are purr-fectly capable of recognizing their own names. Getting a treat or cuddles as a reward is part of how cats learn to recognize a name. However, owners may also use their cat’s name in a negative setting, like yelling at Fluffy to get off the stove. As a result, cats can probably learn to associate these familiar utterances with good and bad experiences, Saito notes. And that might not be great for cat-human relations. So only using a cat’s name in a positive context and using a different term in a negative context could help cats and humans communicate more clearly.

So cats may recognize their names. But will they come when called? Don’t get your hopes up.

[sciencenewsforstudents]

Some spiders may spin poisonous webs laced with neurotoxins

The sticky silk threads of spider webs may be hiding a toxic secret: potent neurotoxins that paralyze a spider’s prey.

Orb weaver spiders are known for their big, beautiful webs. Now, researchers suggest that these webs do more than just glue a spider’s meal in place — they may also swiftly paralyze their catch.

Biochemical ecologist Mario Palma has long suspected that the webs of orb weavers — common garden spiders that build wheel-shaped webs — contain neurotoxins. “My colleagues told me, ‘You are nuts,’” says Palma, of São Paulo State University’s Institute of Biosciences in Rio Claro, Brazil. No one had found such toxins, and webs’ stickiness seemed more than sufficient for the purpose of ensnaring prey.

The idea first came to him about 25 years ago, when Palma lived near a rice plantation where orb weavers were common. He says he often saw fresh prey, like bees or flies, in the spiders’ webs, and over time, noticed the hapless animals weren’t just glued — they convulsed and stuck out their tongues, as if they’d been poisoned. If he pulled the insects free, they struggled to walk or hold up their bodies, even if the web’s owner hadn’t injected venom.

Palma had worked with neurotoxins for many years, and these odd behaviors immediately struck him as the effects of such toxins.

Now, thanks in large part to the work of his Ph.D. student Franciele Esteves, Palma thinks he has found those prey-paralyzing toxins. The pair and their colleagues analyzed the active genes and proteins in the silk glands of banana spiders (Trichonephila clavipes) — a kind of orb weaver — and found proteins resembling known neurotoxins. The neurotoxins may make the webs paralytic traps, the team reports online June 15 in the Journal of Proteome Research. The prey-catching webs of other species probably have similar neurotoxins, Palma says.

These neurotoxin proteins also showed up on the silk of webs collected in Rio Claro, packed into fatty bubbles in microscopic droplets on the strands. And when the researchers rinsed substances from webs and injected them into bees, the animals became paralyzed in less than a minute.

The researchers also confirmed, as Palma’s lab had reported in 2006, that fatty acids are present in the droplets. These acids, Palma thinks, are the toxins’ way into prey. The molecules may dissolve the insect’s waxy outer cuticle, the chief barrier to topical toxins.

“Toxic webs would certainly make sense,” says David Wilson, a venom researcher at James Cook University in Cairns, Australia, but he’d like to see evidence that the web toxins work quickly on contact. Alternatively, they might act as antimicrobials (SN: 10/30/19) or help deter ants and other animals that steal from webs or eat the spiders.

Jolanta Beinaroviča, a synthetic spider silk designer at the University of Nottingham in England, says, “This paper was like a breath of fresh air.” She thinks many researchers have long oversimplified spider web silks, though she, too, would like to see further demonstration of the toxins’ topical action.

Paralytic toxins may be just part of the underappreciated complexity of web design. Palma plans to have his students dive deeper into smaller, as of yet unidentified proteins his team found. He thinks they may help keep the prey alive until the spider’s ready for a fresh meal.

[sciencenewsforstudents]

A nose-horned dragon lizard lost to science for over 100 years has been found

It’s now known that a Modigliani’s lizard, first found in 1891 in Indonesia, is bright green but can shift shades like a chameleon.

Nearly 130 years ago, Italian explorer Elio Modigliani arrived at a natural history museum in Genoa with a lizard he’d reportedly collected from the forests of Indonesia.

Based on Modigliani’s specimen, the striking lizard — notable for a horn that protrudes from its nose — got its official taxonomic description and name, Harpesaurus modiglianii, in 1933. But no accounts of anyone finding another such lizard were ever recorded, until now.

This illustration of Modigliani’s nose-horned lizard was made in 1933 based on the original lizard first found in 1891. That specimen turned pale blue due to how it was preserved.

CREDIT: C.A. PUTRA ET AL/TAPROBANICA: THE JOURNAL OF ASIAN BIODIVERSITY, 2020, ANNALI DEL MUSEO CIVICO DI STORIA NATURALE DI GENOVA 56, PL. VI 

In June 2018, Chairunas Adha Putra, an independent wildlife biologist conducting a bird survey in a mountainous region surrounding Lake Toba in Indonesia’s North Sumatra, called herpetologist Thasun Amarasinghe. Near the lake, which fills the caldera of a supervolcano, Putra had found “a dead lizard with interesting morphological features, but he wasn’t sure what it was,” says Amarasinghe, who later asked the biologist to send the specimen to Jakarta.

It took only a look at the lizard’s nose-horn for Amarasinghe to suspect that he was holding Modigliani’s lizard. “It is the only nose-horned lizard species found in North Sumatra,” he says.

Wooden arts and folktales of the Bataks — indigenous people native to the region — show that lizards have a special place in the people’s mythology. “But simply there was no report at all about this species” following Modigliani’s, says Amarasinghe, of the University of Indonesia in Depok.

He asked Putra to get back to the caldera to see if there was a living population. After five days, Putra found what he was looking for one evening, “lying on a low branch, probably sleeping,” according to the biologist. He took pictures of the lizard and measured the size and shape of its body parts, such as the length of its nose-horn and head. He also observed its behavior before finally releasing it the same night.

A Modigliani’s nose-horned lizard is typically bright green and yellow (top), but the reptile turns brownish-orange under stress (bottom).

Credit: C.A. PUTRA ET AL/TAPROBANICA: THE JOURNAL OF ASIAN BIODIVERSITY, 2020

Using this data, Amarasinghe compared the lizard with the one described in 1933, and concluded that the living lizard and the dead one that Putra had stumbled across were in fact Modigliani’s nose-horned lizards. The Genoa museum’s dead specimen is pale blue due to preservation, but it’s now known that the lizard’s natural color is mostly luminous green. Its camouflage and tree-dwelling behavior are similar to African mountain chameleons, Amarasinghe, Putra and colleagues report in the May Taprobanica: The Journal of Asian Biodiversity.

The reptile belongs to the Agamidae family of lizards, which are commonly called dragon lizards and include species such as bearded dragons (SN: 6/14/17). Shai Meiri, a herpetologist at Tel Aviv University, has previously shown that many dragon lizards live in small, hard-to-access areas, making the reptiles difficult to study. There are 30 agamid species that have never been seen since they were first described, and 19 species which are known from just a single specimen, Meiri says.

While thrilled with their find, Amarasinghe and Putra are worried about the lizard’s future. “The living dragon was found outside a conservation area, and massive deforestation is happening nearby,” Amarasinghe says.

But the rediscovery offers a glimmer of hope for the lizard’s conservation, Meiri says. Before the reptile resurfaced, no one knew where exactly Modigliani’s lizard lived, or whether it had already gone extinct, he says. But now, “we can study it, understand its conservation needs and hopefully implement conservation measures.”

[sciencenewsforstudents]

The first frog fossil from Antarctica has been found

An ancient amphibian from Antarctica gives new insight into when the continent got so cold.

The first fossil of a frog found in Antarctica gives new insight into the continent’s ancient climate.

Paleontologists uncovered fragments of the frog’s hip bone and skull in 40-million-year-old sediment collected from Seymour Island, near the tip of the Antarctic Peninsula.

Scientists have previously found evidence of giant amphibians that walked Antarctica during the Triassic Period, over 200 million years ago, but no traces on the continent of amphibians like those around today (SN: 3/23/15). The shape of the newly discovered bones indicates that this frog belonged to the family of Calyptocephalellidae, or helmeted frogs, found today in South America.

The fossilized frog’s modern relatives live exclusively in the warm, humid central Chilean Andes. This suggests that similar climate conditions existed on Antarctica around 40 million years ago, researchers report April 23 in Scientific Reports.

A new frog fossil suggests that millions of years ago, at least part of Antarctica (shown in this illustration) looked a lot like the Chilean Andes. CREDIT: POLLYANNA VON KNORRING/SWEDISH MUSEUM OF NATURAL HISTORY, SIMON PIERRE BARRETTE, JOSÉ GRAU DE PUERTO MONTT, MATS WEDIN/SWEDISH MUSEUM OF NATURAL HISTORY, WIKIMEDIA COMMONS (CC BY-SA 3.0)

That offers a clue about how fast Antarctica switched from balmy to bitter cold (SN: 1/1/20). Antarctica quickly froze over after splitting from Australia and South America, which were once all part of the supercontinent Gondwana (SN: 10/10/19). But some geologic evidence suggests that ice sheets began forming on Antarctica before it fully separated from the other southern continents about 34 million years ago.

“The question is now, how cold was it, and what was living on the continent when these ice sheets started to form?” says study coauthor Thomas Mörs, a paleontologist at the Swedish Museum of Natural History in Stockholm. “This frog is one more indication that in [that] time, at least around the Peninsula, it was still a suitable habitat for cold-blooded animals like reptiles and amphibians.”