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Today we have several cat videos and some memes, but nothing that takes intellectual acumen to appreciate.  We won’t have a Caturday Felid next week as I’m going to California, and posting of everything will be light. So enjoy this one, and we’ll be back on the 27th of January.

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First, a 5½-minute video of cats getting what they hate most: wet.  There’s nothing sadder than a sodden cat.  Listen to the orange moggie howl in the second clip! In the third, I don’t know why the video makers don’t immediately rescue the cat. That’s cruel!

Tbe cats pawing at the door are presumably trying to get out of the rain. Once again, their staff just stands by and take a video. And there’s one cat who falls in the toilet!

The Siamese at 4:45 makes quite a racket.

But, in general, people who stand by and take a video of a distressed cat without helping it are reprehensible. Don’t be one of them!

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Now a 4+-minute video of cats getting what they like most (well, next to food): NIP! This is one more advantage of cats over d*gs, as there’s no such thing as d*gnip.  You can’t get your d*g high!

You can clearly see the variety of their reactions: some wallow in the stuff; others largely ignore it.  There’s a bit of information at the end.

petMD and Wikipedia both have useful articles on catnip, the former with information for cat staff and the latter general information about the plant and its effects.

From petMD:

Cats have an extra scent organ called the vomeronasal gland in the roof of their mouth. This special pathway allows scents that are collected in the nose and mouth to be carried to the brain.

Nepetalactone is the oil that’s found within the catnip plant’s leaves that can cause behavioral changes in cats. For a cat to be exposed to this substance, they have to smell the catnip.

Catnip mimics feline sex hormones, so cats enjoying this substance will often display behaviors similar to a female cat in heat (although both male and female cats can experience the effects).

These behaviors can include overt signs of affection, relaxation, and happiness. Other cats will display active behaviors, such as playfulness or sometimes even aggression.

For cats that have a positive experience with catnip, it can help reduce anxiety and even relieve pain.

Some veterinarians have recommended using catnip to help with separation anxiety if your cat will be home alone for an extended period of time.

About 60% of cats show a catnip reaction, and Wikipedia reports that the difference is not due to a single gene form, but appears to be polygenic, that is, it’s like many human maladies, in which you have to have a combination of different gene forms (and often a certain environment) to show a trait.  As for other species, it says this:

Catnip contains the feline attractant nepetalactone. N. cataria (and some other species within the genus Nepeta) are known for their behavioral effects on the cat family, not only on domestic cats, but also other species. Several tests showed that leopards, cougars, servals, and lynxes often reacted strongly to catnip in a manner similar to domestic cats. Lions and tigers may react strongly as well, but they do not react consistently in the same fashion.

Here’s a controlled experiment showing that some big cats do react to catnip: about 72% of the big cats showed a positive reaction, but it differs greatly among species.

Here’s nepetalactone:

Finally, catnip is often grown as an ornamental plant in gardens, and I recommend it, as cats will come around, eat it, and act weird.  And you can also make catnip tea from it, supposedly a relaxant for humans. I’ve had it, but it didn’t really relax me: I just rolled around on the ground for 15 minutes.

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Bored Panda (click in screenshot below) has a variety of cat memes—50 of them. I’ll show a few of my favorites below.

 

 

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Lagniappe: A cat fiddles with its staff’s  elaborate model train set:

h/t: Ginger K.

Today we have a post on Australian trees, the eucalypts, contributed by Reader Rodney Graetz.  This is part 1 of a two-part series. Rodney’s captions are indented, and you can enlarge the photos by clicking on them.

The Trees that identify Australia

Australia is one of many countries that include plants as part of their identity.  The national floral emblem is the Golden Wattle (Acacia pycnantha), one of more than 1000 Acacia species found on the continent.  The two colours of the plant represent the essence of the continent.  The golden flowers represent its beaches, mineral wealth, grain, and wool harvests.  The green of the (leathery) leaves imitates the continent’s forests and productive landscapes.

Internationally, when Australian sporting teams compete, here Cricket, their uniforms are always in the national floral emblem colours: the Green and the Gold.

What trees identify Australia by being visually dominant in the country’s diverse landscapes?  Only one tree group emphatically says Australia, and that is the Eucalypts, aka ‘Gum Trees’.  Though diverse in size, form, and colouring, this is a typical specimen.  They are all substantial evergreen hardwood trees, with tough, leathery, long-lived leaves, and the annually renewed bark can be rough or smooth, and multi-coloured.  Though widely called ‘Gum Trees’, only a few species produce a solidifying liquid ‘gum’ from surface wounds.  In contrast, all Eucalypt leaves contain aromatic ‘oils’ which render them highly flammable and fragrant, when green, and especially so, when dried.

From an estimated 900+ species total, a small sample of the variation in appearance of the adult trees is this collage of the bark of just eleven different Eucalypts.

Initially named as just one genus, Eucalyptus, it now includes Corymbia and Angophora.  Together they are still called ‘Eucalypts’, because of their common flower structure with sepals and petals fused to a cap (calyptra) and the showy insect-attracting role played by numerous stamens.  There is significant species variation in flower size and colour.’

In a 55 million-year evolutionary history, Eucalypts have evolved characteristics to repel leaf-eating animals.  Rapidly evolving insects remain the most successful, while vertebrate folivores are largely excluded by sclerophylly, the leaves are woody, and by the production of toxic chemicals.  The only vertebrate dependent on Eucalypt leaves is the marsupial Koala (Phascolarctos cinereus), which spends far more time (10-15 hours) digesting than harvesting leaves.

Australia is justifiably called “A Burning Continent”, with Africa being called “The Burning Continent”.  Eucalypts are a noticeable component of all Australian landscapes, with the exception of the sandplain deserts, and the (>2000m) high country.  Wherever Eucalypts are found, wildfire is possible, only the frequency varies.  The two principal adaptations of Eucalypts to frequent fire are increased bark thickness, and the capacity to produce new (epicormic) shoots anywhere along a burnt stem or branch.

Tall forests, such as this, occur only in the two wettest, temperate regions of the continent, where one species (Eucalyptus regnans) has been recorded as the Earth’s tallest flowering plant at 100 metres (330 feet).  The species here is Karri (Eucalyptus diversicolor).

The sub-tropical, Eucalypt-dominated, savannas are always impressive in the early dawn light with the blackened record of their frequent (1-3 years) fires is visible in their bark.

Growing at the low temperature limit of Eucalypts,  the Snow Gums (Eucalyptus pauciflora), are more shaped by the blizzard winds than by the brief snowfalls.

Part 2 to come.

Brain scans of 110 first-time mothers during and after pregnancy showed that some brain regions become thinner during pregnancy and that giving birth largely reverses this effect

Will this ever end? Eventually.

The post Skeptics in the Pub. Cholera. Chapter 7b first appeared on Science-Based Medicine.

Astronomers working with TESS (Transiting Exoplanet Survey Satellite) have discovered a planet that’s been left out in the Sun too long. Or at least half of it has. The newly discovered planet is tidally locked to its star, and one side is completely molten.

The new planet was discovered orbiting a star named HD 63433. The star is young, only about 400 million years old, and it’s about the same mass and radius as the Sun. It’s also a G-type star like our Sun.

The planet is named HD 63433 d, and it’s the third planet found in the system, though the other two were found a couple of years ago. It’s rocky and about the same size as Earth, but that’s where the similarities end.

HD 63433 d is less than 500 million years old. That puts it in a particular category since of the thousands of confirmed exoplanets we’ve found, only 50 are estimated to be less than half a billion years old. It’s also the smallest Earth-like planet found this close to us. It orbits its star in about 4.2 days and is about eight times closer to its star than Mercury is to the Sun. The result?

The side of the planet that faces the star gets no reprieve from the star’s powerful radiation. The planet’s dayside reaches 1,257 C (2,294 F.) That means it’s blistering hot lava and will likely spend billions of years in this state. This rules out any potential habitability, and habitability is the holy grail of exoplanet research.

But HD 63433 d is more than just another lifeless exoplanet. It’s a valuable piece of the puzzle in the quest to understand how planets form and evolve. This type of planet is such an important target in science that TESS has an entire project aimed at them: THYME.

The discovery is presented in a new paper titled “TESS Hunt for Young and Maturing Exoplanets (THYME). XI. An Earth-sized Planet Orbiting a Nearby, Solar-like Host in the 400 Myr Ursa Major Moving Group.” It was published in The Astronomical Journal and presented in a Jan. 10 presentation at the 2024 American Astronomical Society Meeting. The lead author is Benjamin Capistrant, a graduate student in astronomy at the University of Florida.

“Young terrestrial worlds are critical test beds to constrain prevailing theories of planetary formation and evolution,” the authors write. The fact that HD 63433 d is half lava doesn’t change that. Studying it will help planetary scientists study atmospheric loss. Also, the light from its star is so bright that it enables accurate spectroscopy.

This figure from the research illustrates how rare exoplanets like HD 63433 d are. The x-axis is the distance from Earth, and the y-axis is the planetary radius. Each grey circle is a known exoplanet, while each blue pentagon is a known exoplanet younger than 500 million years old. The yellow star represents HD 63433 d, the nearest, young, Earth-sized exoplanet discovered to date. Image Credit: Capistrant et al. 2024

“The apparent brightness of the stellar host makes this transiting multiplanet system favourable to further investigations, including spectroscopic follow-up to probe the atmospheric loss in a young Earth-sized world,” the authors explain.

The first few hundred million years in the life of a planet is critical. Young solar systems are dynamic places. Collisions between planets and gravitational interactions can force planets to migrate or follow eccentric orbits. There are also abundant impacts by asteroids and planetesimals, which can go on for a long time. In regions of dense star formation, neighbouring stars can even affect the planets in nearby systems.

“Detailed observations of planetary systems in such environments are, therefore, crucial to understanding the general formation history of the exoplanet population,” the authors explain.

This artist’s illustration shows an exoplanet tidally locked to its star. The side facing the star is so hot it’s molten rock. Image Credit: NASA/Kepler Mission/Dana Berry

Besides its size and proximity to Earth, why is HD 63433 d important? It comes down to exoplanet atmospheres.

“Currently, one of the most important inquiries in exoplanet science is understanding in which circumstances planets keep or lose their thick primordial hydrogen/helium atmospheres and what physical processes drive this phenomenon,” the authors write.

There’s a mass gap in the radius distribution of small exoplanets that scientists refer to as the small planet radius gap. For some reason, there’s a scarcity of small planets between about 1.5 and 2 times Earth’s radius. There’s no reason to think that planets don’t form at these radii, so scientists believe planets lose mass and end up smaller.

A histogram of planets with given radii from a sample of 900 Kepler systems. The decreased occurrence rate between 1.5 and 2.0 Earth radii is apparent. [Fulton et al. 2017]

Planetary scientists aren’t sure what drives the mass loss that creates the gap, but two primary mechanisms could be responsible. One is extreme ultraviolet photoevaporation. Young stars emit powerful UV radiation that can drive the atmosphere away from a planet into space.

The other mechanism is core-powered mass loss. With this mechanism, the luminosity of the cooling planetary core provides the energy for atmospheric loss. These cores start out hot due to their assembly and formation, as the gravitational energy that binds them together is converted into heat. As the cores cool, the heat can drive away the atmosphere.

These mechanisms work on different time scales, and that’s why the youthful HD 63433 d is such a compelling subject for study. Since its radius is below the radius gap, it’s likely rocky. But if mass loss takes longer than 500 million years, it could still have a thick atmosphere. “Because Earth-sized planets orbiting young, Sun-like stars have so far been difficult to detect, HD 63433 d presents a particularly compelling case study for atmospheric investigations of close-orbiting Earth-sized planets,” write the authors.

This discovery is important because the planet is such a valuable target for future, more detailed observations of its atmosphere. “It would be valuable to interrogate the planet’s mass using precise radial velocities and determine whether the composition is indeed rocky, as expected based on observations of older planets,” the researchers explain.

The first step is confirming that HD 63433 d is, in fact, a rocky planet. The JWST has a role to play in this, as its MIRI instrument has already been used to capture the thermal emissions of rocky exoplanets. These measurements provide a benchmark astronomers can use to compare JWST observations of HD 63433 d with other rocky planets. “Moreover, the star’s unusual brightness should provide plenty of photons to make these sensitive measurements,” the authors write.

Most rocky planets, Earth included, are magma ocean planets after they initially form. Repeated impacts keep the planet’s surface molten. But some, like HD 63433 d, remain half-molten for billions of years. That may doom them to eternal lifelessness, but as this research shows, they have much to tell us.

It could be the key that unlocks the mystery of the small planet radius gap.

The post Half of this Exoplanet is Covered in Lava appeared first on Universe Today.

According to the most widely accepted scientific theory, our Solar System formed from a nebula of dust and gas roughly 4.56 billion years ago (aka. Nebula Theory). It began when the nebula experienced gravitational collapse at the center, fusing material under tremendous pressure to create the Sun. Over time, the remaining material fell into an extended disk around the Sun, gradually accreting to form planetesimals that grew larger with time. These planetesimals eventually experienced hydrostatic equilibrium, collapsing into spherical bodies to create Earth and its companions.

Based on modern observations and simulations, researchers have been trying to understand what conditions were like when these planetesimals formed. In a new study, geologists from the California Institute of Technology (Caltech) combined meteorite data with thermodynamic modeling to better understand what went into these bodies from which Earth and the other inner planets formed. According to their results, the earliest planetesimals have formed in the presence of water, which is inconsistent with current astrophysical models of the early Solar System.

The research was conducted in the laboratory of Paul Asimow, the Eleanor and John R. McMillan Professor of Geology and Geochemistry at Caltech. The team was led by assistant professor Damanveer Grewal, the leader of the CosmoGeo Lab at Arizona State University (ASU) and a former postdoctoral scholar with the Division of Geological and Planetary Sciences at Caltech. Grewal and Asimow were joined by planetary scientists from the Massachusetts Institute of Technology (MIT), the University of California Los Angeles (UCLA), and Rice University.

Sample from a rare meteorite family revealing that its parent planetesimal had a layered structure with a molten core and solid crust (similar to Earth). Credit: Carl Agee, Institute of Meteoritics UNM/MIT

Grewal and his colleagues specialize in studying the chemical signatures of iron meteorites to gather information about the early Solar System. These meteorites are remnants of the metallic cores of the first planetesimals that did not accrete to form a planet and continue to orbit within our Solar System today. Over many eons, some of these objects fell into Earth’s gravity well and ultimately crashed to the surface. The chemical composition of these meteorites is of particular interest since it reveals a great deal about the environments in which they formed.

For one thing, the composition of planetesimals can reveal whether they (and Earth) formed closer to or farther away from the Sun. If the former scenario were the case, cooler conditions would have allowed Earth to retain water ice as a building block. If the latter is correct, Earth would have formed dry and obtained its water by some other means later on, which is what current astrophysical models suggest. According to these models, water was delivered to the inner Solar System via comets and asteroids billions of years ago, a period known as the Late Heavy Bombardment.

While water is no longer present in these meteorites, scientists can infer its existence from the presence of other elements. These include iron oxide (FeO), which occurs when iron is oxidization by exposure to water. A sufficient excess of water will drive the process further, creating ferric oxide (Fe2O3) and ferric oxyhydroxide, or FeO(OH) – the ingredients of rust. While the earliest planetesimals would have lost all traces of iron oxide long ago, Grewal and his team were able to determine how much was present by examining the metallic nickel, cobalt, and iron contents of these meteorites.

These three elements should be present in roughly equal ratios relative to other materials in the meteorite, which means that any “missing” iron would have been depleted through oxidation. As Asimow explained in a Caltech news release:

“Iron meteorites have been somewhat neglected by the planet-formation community, but they constitute rich stores of information about the earliest period of Solar System history, once you work out how to read the signals. The difference between what we measured in the inner solar system meteorites and what we expected implies an oxygen activity about 10,000 times higher.”

Artist concept of Earth during the Late Heavy Bombardment period. Credit: NASA’s Goddard Space Flight Center.

The team’s results indicate that meteorites believed to have originated in the inner Solar System had roughly the same amount of missing iron as meteorites from the outer Solar System. This suggests that both groups formed in a part of the Solar System where conditions were cool enough for water. It further implies that planets accreted water from the beginning, which could have profound implications for theories of how life emerged on Earth. “If water was present in the early building blocks of our planet, other important elements like carbon and nitrogen were likely present as well,” said Grewal. “The ingredients for life may have been present in the seeds of rocky planets right from the start.”

This represents a significant challenge for our current models for how the Solar System formed and evolved, which could indicate that conditions in the early inner Solar System were much cooler than previously thought. The results could also mean that Earth and its fellow rocky planets formed farther from the Sun and gradually migrated to their current orbits. However, as Asimow acknowledged, there is a degree of uncertainty when it comes to the study of ancient planetesimals, which means the results may not contradict current astrophysical models:

“However, the method only detects water that was used up in oxidizing iron. It is not sensitive to excess water that might go on to form the ocean. So, the conclusions of this study are consistent with Earth accretion models that call for late addition of even more water-rich material.”

Their study, titled “Accretion of the earliest inner Solar System planetesimals beyond the water snowline,” recently appeared in Nature Astronomy. Their research was made possible thanks in part to funding provided by NASA and through a Barr Foundation Postdoctoral Fellowship.

Further Reading: Caltech, Nature Astronomy

The post The Meteorites That Made Earth Were Filled With Water appeared first on Universe Today.

NASA is hoping to gather evidence that its X-59 aircraft will be able to fly at the speed of sound quietly, justifying a change in the regulations to allow supersonic commercial aviation

A secure exchange between a merchant and a buyer has been successfully tested as a proof of concept using a small quantum computing network in China

An artificial intelligence model can discern whether fingerprints from different fingers come from the same person, which could make forensic investigations more efficient

By building a 3D image of part of the surface of a comet called 67P, astronomers have discovered caves up to 47 metres deep

Oxidative coupling of methane (OCM) is now one step closer to leaving the lab and entering the real world. Researchers have developed an OCM catalyst that exceeds 30 percent when it comes to the production of ethylene.

Researchers have developed a unique catalyst that promises to revolutionize drug synthesis. It overcomes a common problem associated with the production of drugs from ketones. Using their catalyst, the researchers synthesized a key component of the commonly used incontinence drug oxybutynin. Their results underscore the potential of the catalyst to improve drug discovery and development.

Researchers at NASA's Goddard Space Flight Center have discovered X-ray activity that sheds light on the evolution of galaxies.

Big tech companies are offering new ways to interact with devices, powered by natural language processing – but here's why we are unlikely to give up our screens just yet

A combination of cooling technologies and techniques could reduce the temperature and energy needs of Riyadh, Saudi Arabia.

Researchers use light-reactive molecules to influence the acidity of a liquid and thereby capture of carbon dioxide. They have developed a special mixture of different solvents to ensure that the light-reactive molecules remain stable over a long period of time. Conventional carbon capture technologies are driven by temperature or pressure differences and require a lot of energy. This is no longer necessary with the new light-based process.

Researchers are using crystallography to gain a better understanding of how proteins shapeshift. The knowledge can provide valuable insight into stopping and treating diseases.

Scientists were able to show that statistical models created by artificial intelligence (AI) predict very accurately whether a medication responds in people with schizophrenia. However, the models are highly context-dependent and cannot be generalized.

An international team of scientists provide an overview of the latest research on light-matter interactions. In a new paper, they provide an overview of the latest research on polaritons, tiny particles that arise when light and material interact in a special way.