Paleontologists have examined the fossilized remains of a previously unknown species of eurypterid (sea scorpion) and found direct evidence that these marine creatures were able to breathe in subaerial environments through their main respiratory organs.
The new species, named Adelophthalmus pyrrhae, lived about 350 million years ago during the Carboniferous period.
It belongs to Eurypterida, a large group of extinct arthropods that thrived from the Ordovician through the Permian period.
Their closest living relatives are horseshoe crabs, which lay eggs on land but are unable to breathe above water.
The three-dimensionally preserved specimen of Adelophthalmus pyrrhae was found 25 years ago in the Lydiennes Formation in Montagne Noire region, France.
Using micro computed tomography (μ-CT) imaging technique, Dr. Lamsdell and colleagues studied the respiratory organs of Adelophthalmus pyrrhae.
First, they noticed that each gill on the sea scorpion was composed of a series of plates. But the back contained fewer plates than the front, prompting them to question how it could even breathe.
Then they zeroed in on trabeculae — pillars connecting the different plates of the gill, which are seen in modern scorpions and spiders.
The discovery of air-breathing structures in Adelophthalmus pyrrhae indicates that terrestrial characteristics occurred in the arachnid stem lineage, suggesting that the ancestor of arachnids were semi-terrestrial.
References: James C. Lamsdell et al. Air Breathing in an Exceptionally Preserved 340-Million-Year-Old Sea Scorpion. Current Biology, published online September 10, 2020; doi: 10.1016/j.cub.2020.08.034
Among the major health challenges for astronauts during prolonged space travel are loss of muscle mass and loss of bone mass. One signaling pathway that plays an important role in maintaining muscle and bone homeostasis is that regulated by the secreted signaling proteins, myostatin (MSTN) and activin A. In the recent study, Emily Lee and colleagues investigated the effects of targeting the signaling pathway mediated by the secreted signaling molecules, myostatin and activin A, in mice sent to the International Space Station.
They found that 24 of the 40 mice were normal, eight of them were missing the myostatin gene and eight others were treated with a molecule that suppressed both myostatin and a protein known as activin A, which has similar effects on muscle as myostatin.
Normal mice — those that carried the myostatin gene and received no protein-inhibiting treatments — lost significant muscle and bone mass during the 33 days spent in microgravity. In contrast, mice that were missing the myostatin gene and had a muscle mass about twice that of a regular mouse, largely retained their muscles during spaceflight.
Also, systemic inhibition of MSTN/activin A signaling using a soluble form of the activin type IIB receptor (ACVR2B), which can bind each of these ligands, led to dramatic increases in both muscle and bone mass, with effects being comparable in ground and flight mice.
They concluded that targeting this signaling pathway (MSTN/activin A) has significant beneficial effects in protecting against both muscle and bone loss in microgravity, suggesting that this strategy may be effective in preventing or treating muscle and bone loss not only in astronauts on prolonged missions but also in people with disuse atrophy on Earth, such as in older adults or in individuals who are bedridden or wheelchair-bound from illness.
References: Se-Jin Lee, Adam Lehar, Jessica U. Meir, Christina Koch, Andrew Morgan, Lara E. Warren, Renata Rydzik, Daniel W. Youngstrom, Harshpreet Chandok, Joshy George, Joseph Gogain, Michael Michaud, Thomas A. Stoklasek, Yewei Liu, and Emily L. Germain-Lee, “Targeting myostatin/activin A protects against skeletal muscle and bone loss during spaceflight”, PNAS, 2020, doi: https://doi.org/10.1073/pnas.2014716117
In 2016, NASA’s Juno probe entered orbit around Jupiter and discovered giant cyclones arranged in geometric patterns around the world’s poles. At the planet’s north pole, there are eight vortices surrounding a central vortex, and at the south pole there are six.
Each gargantuan tempest ranges between 2,485 to 4,350 miles (4,000 to 7,000 kilometers) wide, and they encircle their respective poles at distances of 5,400 miles (8,700 km). These cyclones and these patterns have endured for at least four years since Juno arrived at Jupiter.
It was a mystery to scientists as to how these clusters kept stable. On Earth, cyclones drift poleward but dissipate over land and cold water. In contrast, Jupiter has neither land nor oceans, raising the question of why the cyclones did not simply drift to the poles and merge. What atmospheric properties distinguish Jupiter from Saturn, which has only one cyclone at each pole?
To shed light on Jupiter’s cyclones, Li and his colleagues now model the vortices using the shallow water equations, which describe a single layer of fluid that moves horizontally and has a free surface that moves up and down in response to fluid convergence and divergence. Their models are based on what Juno revealed about the sizes and speeds of the storms. They focused on what factors might keep these geometric patterns stable over time without merging.
The researchers found the stability of these patterns depend partly on how deep the cyclones reach down into Jupiter’s atmosphere, but mostly on anticyclonic rings around each cyclone — that is, a ring of wind spinning in the opposite direction that each cyclone is whirling in. Too little shielding from anticyclone rings led to the cyclones merge; too much shielding could drive the cyclones apart from each other.
Why Jupiter’s vortices occupy this middle range is unknown. The budget—how the vortices appear and disappear—is also unknown, since no changes, except for an intruder that visited the south pole briefly, have occurred at either pole since Juno arrived at Jupiter in 2016.
References: Cheng Li, Andrew P. Ingersoll, Alexandra P. Klipfel, and Harriet Brettle, “Modeling the stability of polygonal patterns of vortices at the poles of Jupiter as revealed by the Juno spacecraft”, PNAS, 2020. Doi: https://doi.org/10.1073/pnas.2008440117
Is it cold in here, or is it just the solid ice walls? As of December 2016, Sweden is home to the world’s first year-round ice and snow hotel. A night in an igloo in July is now totally possible — just be sure to bundle up.
The concept of a hotel made entirely of ice and snow isn’t new. Sweden’s original ICEHOTEL was a pop-up that let visitors book a stay any time from December to April. Since, obviously, an icy suite requires freezing temps in order to stay not-liquid, it wasn’t always an available option for travelers. But due to increasing demand, the people behind the original concept opened ICEHOTEL 365, a permanent ice hotel in Jukkasjärvi, Sweden.
Here’s some Earth-shattering news: ice melts. In order to prevent ICEHOTEL 365 from turning into a slushy snow cone, a crew of 100 people took five months to make it sustainable. As Forbes reports, they achieved this “first by making a steel construction and inserting a cooling system, then by turning 30,000 liters of water from the Torne River into several tons of ice and snow, and using them to cover the walls, ceiling, ground, plus all the rooms. […] Steel pipes are drilled into the permafrost (at 16 feet below ground) to keep the building at 23 degrees (Fahrenheit).”
Let’s address the giant polar bear in the room … isn’t it, like, really cold in there? The hotel never dips below 23º F (toasty, right?), so that’s a start. Don’t freak out though. At night, the hotel staff will supply you with seriously intense sleeping equipment. It’s an “expedition sleeping bag” that goes all the way over your head but gives you a little circular window for your face to peep out of. These sleeping cocoons are made for temperatures as low as -13°F (-25°C), so you should be good. But if that doesn’t quite warm your bones, hot lingonberry juice on tap and a morning sauna should do the trick.
Not unlike the movie of the same name, Madagascar is a wild, unique place. (Great flick, by the way.) The African island nation is home to a slew of endemic species and breathtaking natural landscapes to match. All that considered, it shouldn’t be too shocking to hear that the country boasts the world’s largest stone forest. It has a smaller one that’s bright red, too. Yes, we’re sure this isn’t Mars.
The fourth largest island on Earth, Madagascar is home to plenty of double-take-worthy sights. The country developed independently, which sets the culture apart from the rest of Eastern Africa. Because the country was under French rule until 1960, there is evidence of French architecture throughout the cities. Mixed in with the old colonial vibe, the island’s original wooden architectural tradition can also be found, a tradition that was added to the UNESCO list of Intangible Cultural Heritage in 2003. But let’s talk nature too. First of all, lemurs. Second, tsingys. Third, lemurs on tsingys. Just keep reading.
What’s this tsingys? In Malagasy, “tsingy” means “where one cannot walk barefoot.” And that’s no joke. The word refers to tall, thin, needle-like rock formations that can be found throughout the country. Not to freak you out, but just one misstep through a tsingy forest could impale somebody.
The Tsingy de Bemaraha Strict Nature Reserve, a UNESCO World Heritage site, is the largest example of a tsingy forest on Earth. How big? The reserve, which includes the veritable cathedral of limestone, stretches 375,600 acres. But the height is the really scary part; some of the rock pinnacles can reach 2,600 feet. Not only a stunning and/or terrifying sight to behold, this Tsingy in central west Madagascar is also a hub for endemism, as it’s home to many unique endangered flora and fauna (including — you guessed it — lemurs).
NASA notes that the formation of the Tsingy began some 200 million years ago when layers of calcite at the bottom of a lagoon formed a thick limestone bed. Later, “tectonic activity elevated the limestone, and as sea level fell during the Pleistocene ice ages, even more of the limestone was exposed. No longer underwater, the ancient sediments were carved by monsoon rains, which washed softer rocks away and left tougher rocks standing. Meanwhile, groundwater carved caves below the surface. As cave ceilings gave way, canyons formed between rocky towers.”
Need something a little more Instagrammable? Tsingy Rouge is another stone forest you can find in the country. Oh, but this one is bright red. This Mars-like Madagascar landscape is the beautiful result of erosion.
If you’re bored with the same old rivers, head to Colombia where you can see something that looks like the end result of a collaboration between James Cameron, Timothy Leary, and a box full of melted crayons.
Travel east of the Andes and you’ll find Los Llanos, a massive portion of open grasslands. It’s home to Caño Cristales, a river often called the “Liquid Rainbow.” The jaw-dropping collision of colors is caused by macarenia clavigera, aquatic plants unique to the body of water that shine brightly through the surface in various colors. The 62-mile stretch of water is as gorgeous as it is delicate.
Macarenia clavigera turn various colors depending on their depth and the amount of light they’re getting. If you visit between September and November, you’ll encounter reds, blues, yellows, oranges, and more. The plants cover most of the riverbed, so there’s color at every turn.
This river is the only place in the world where this life can grow. The plants are delicate, and require extremely specific conditions to survive. They’re are so fragile, they can be hurt even by light touches.
It wasn’t long ago when you couldn’t visit Caño Cristales safely, as the region was controlled by guerilla soldiers. These days, a good portion has been regained by the Colombian military, so you are actually able to visit. Still, the region is highly protected because it was so blatantly damaged when visiting was unregulated. Only seven visitors are allowed at a time, with a maximum of 200 people per day.
If you’re considering a visit, one word of caution: don’t pack bug spray or sunscreen, as they would harm the ecosystem. But if you can make it to Caño Cristales, we expect to see a significant upgrade in your Instagram feed.
A team of researchers from Tel Aviv University and Duke University and an expert from Israel Police has analyzed 18 ancient inscriptions dating back to around 600 BCE from Arad, a well preserved desert fort on the southern frontier of the Biblical Kingdom of Judah, and found that the texts were written by at least 12 authors.
The Hebrew inscriptions from the Arad fort, located in the arid southern frontier of Biblical Judah, are one of a few text collections from the First Temple period.
Dated to 600 BCE, more than 100 ostraca — texts written in ink on clay potsherds — provide a record of distribution of provisions to military units shortly before the destruction of the Kingdom of Judah by the invading Babylonian army.
The texts include administrative records, such as lists of names, probably produced at the fort itself, as well as orders that were dispatched to Arad from higher echelons in the Judahite military system, as well as correspondence with neighboring forts.
One of the inscriptions mentions the ‘King of Judah’ and another the ‘House of YHWH,’ probably referring to the Temple in Jerusalem.
Some orders of provisions refer to the Kittiyim, seemingly a Greek mercenary unit/s, which assisted in protecting the Negev desert border from the neighboring Kingdom of Edom.
In the study, Dr. Shaus and colleagues conducted handwriting analysis of 18 inscriptions with the goal of determining the number of writers represented.
They utilized algorithmic analyses to statistically compare writing styles, while the inscriptions were independently analyzed by a professional forensic document examiner.
The examination revealed at least 12 distinct writers, at least 3 of whom were writing at Arad (which is estimated only to have accommodated 20-30 soldiers), and at least 4 of whom were commanders among the regional military.
These results indicate a high literacy rate among the military for the time, notably higher than previous estimates for the Arad inscriptions.
Combined with evidence for high literacy in religious and civic contexts, this suggests the presence of an education system in Judah at the time.
This also has important ramifications for understanding the composition and dissemination of fundamental Biblical texts of the time.
Archaeological evidence suggests that this Hebrew literary activity declined or possibly ceased after the destruction of Jerusalem in 586 BCE.
References: A. Shaus et al. 2020. Forensic document examination and algorithmic handwriting analysis of Judahite Biblical period inscriptions reveal significant literacy level. PLoS ONE 15 (9): e0237962; doi: 10.1371/journal.pone.0237962
Minoan Linear A is still an undeciphered script mainly used on the island of Crete from 1700 to 1400 BCE. A new study published in the published in the Journal of Archaeological Science sheds light on one of the most enigmatic features of Linear A — the precise mathematical values of its system of numerical fractions (such as 1/2, 1/4, 1/8).
Linear A is a logo-syllabic script used for administrative purposes on Bronze Age Crete. Together with Cretan Hieroglyphic, it is one of two writing systems created by the Minoan civilization.
Upon its template, the Mycenaeans later created the Linear B script to register their dialect of ancient Greek.
Today, the Linear A corpus comprises more than 7,400 signs on 1,527 inscriptions, 90% of which are clay documents of administrative nature, such as tablets, roundels, and nodules.
As for numerical notations, Linear A employs a decimal system, with signs representing four magnitudes: units are written with vertical strokes, tens with horizontal strokes or dots, hundreds with circles, and thousands with circles surrounded by strokes.
The system is cumulative and additive, and numbers are written from left to right with the powers in descending order: thus, e.g. 6,352 would be written with six ‘1,000’ signs, three ‘100,’ five ‘10’ and two ‘1.’
Linear A also includes a set of 17 signs that stand for fractions. They are transcribed via capital letters: A, B, D, E, F, H, J, K, L, L2, L3, L4, L6, W, X, Y, and Ω.
To shed light on the values of these fractions, University of Bologna’s Professor Silvia Ferrara and colleagues focused on a specific set of Linear A documents dated to the Late Minoan I period (ca. 1600-1450 BCE).
The researchers applied a method that combines the analysis of the sign shapes and their use in the inscriptions together with statistical, computational and typological strategies to assign mathematical values to the Linear A signs for fractions.
They studied the rules that the signs followed on the clay tablets and other accounting documents.
To investigate the possible values of each fractional sign, they excluded impossible outcomes with the aid of computational methods.
Then all possible solutions — almost four million — were whittled down also comparing fractions that are common in the history of the world (e.g., typological data) and using statistical tests.
Finally, they applied other strategies that considered the completeness and coherence of the fractions as a system and in this way the best values were identified, with the least redundancies.
The result, in this case, was a system whose lowest fraction is 1/60 and which shows the ability to represent most values of the type n/60.
This explained how the Linear B script reused some of these fractions to express units of measurement.
Their results suggested that, for example, the Linear A sign for 1/10 was adapted to represent a capacity unit for measuring dry products which was, in turn, 1/10 of a larger unit. This explains a historical continuity of use from fractions to units of measurements across two different cultures.
References: Michele Corazza et al. The mathematical values of fraction signs in the Linear A script: A computational, statistical and typological approach. Journal of Archaeological Science, published online September 7, 2020; doi: 10.1016/j.jas.2020.105214
The so-called self-interacting dark matter theory helps explain why NGC 1052-DF2 and NGC 1052-DF4, a pair of ultra-diffuse galaxies located approximately 65 million light-years away the constellation of Cetus, contain little dark matter.
The prevailing dark matter theory, known as cold dark matter, or CDM, assumes dark matter particles are collisionless, aside from gravity.
Both theories explain how the overall structure of the Universe emerges, but they predict different dark matter distributions in the inner regions of a galaxy.
SIDM suggests dark matter particles strongly collide with one another in a galaxy’s inner halo, close to its center.
Typically, a visible galaxy is hosted by an invisible dark matter halo. Recent observations of NGC 1052-DF2 and NGC 1052-DF4 (DF2 and DF4 for short) show, however, that these ultra-diffuse galaxies contain very little, if any, dark matter.
Using sophisticated simulations, Dr. Yu and colleagues from Tsinghua University reproduced the properties of DF2 and DF4 through tidal stripping — the stripping away of material by galactic tidal forces — by NGC 1052.
Because the satellite galaxies cannot hold the stripped mass with their own gravitational forces, it effectively gets added to NGC 1052’s mass.
The researchers considered both CDM and SIDM scenarios and found that the latter scenario forms dark-matter-deficient galaxies far more favorably than CDM, as the tidal mass loss of the inner halo is more significant and the stellar distribution is more diffuse in SIDM.
Tidal mass loss could occur in both CDM and SIDM halos. In CDM, the inner halo structure is ‘stiff’ and resilient to tidal stripping, which makes it difficult for a typical CDM halo to lose sufficient inner mass in the tidal field to accommodate observations of DF2 and DF4.
In contrast, in SIDM, dark matter self-interactions could push dark matter particles from the inner to the outer regions, making the inner halo ‘fluffier’ and enhancing the tidal mass loss accordingly. Further, the stellar distribution becomes more diffuse. A typical CDM halo remains too massive in the inner regions even after tidal evolution.