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The design of streets and layout of buildings have an impact on a city's resilience in the face of increasingly severe floods brought on by climate change. Researchers look at buildings and other urban structures as physicists consider elements in complex material systems. With this insight, the researchers have developed a new approach to urban flood modelling and found their results helpful in analyzing city-to-city variations in flood risk globally.

Swiping through online videos to relieve boredom may actually make people more bored and less satisfied or engaged with the content, according to new research.

A new study found that using ChatGPT-4 to read medical notes from Emergency Department admissions to determine whether injured scooter and bicycle riders were wearing a helmet finds that AI can't yet do this reliably.

A view into how nanoscale building blocks can rearrange into different organized structures on command is now possible with an approach that combines an electron microscope, a small sample holder with microscopic channels, and computer simulations, according to a new study.

Two new studies are pointing the way toward round-the-clock personalized care for people with Parkinson's disease through an implanted device that can treat movement problems during the day and insomnia at night.

A new machine learning model can predict autism in young children from relatively limited information. The model can facilitate early detection of autism, which is important to provide the right support.

Up to 100,000 extraordinary species, from spiders and beetles to salamanders and fish, live in subterranean caves and cracks. They aren’t as safe down there as we thought

I’ve generally been avoiding the American news, but I know readers are following it, especially since the Democratic National Convention, whose conclusion is foregone, has started in Chicago. (I’m glad I’m not home, as there will be tons of protests and disruption. I had enough of that in 1968.)

So here’s a discussion thread about politics, or anything else you want to get off your chest. I’ll start it off with a headline from today’s NYT. I dare not even mention my own views any more, as I’ll be given a hiding for saying that I don’t want to vote for either Presidential candidate, and be told off for thereby helping Trump (a misguided view for sure).

Click on the link below to read, or find the article archived here. I’ll give an excerpt. Talk about the election, politics, or anything you want.

An excerpt:

When Hillary Clinton ran for president in 2016, she had more than 200 distinct policy proposals. Four years ago, Joseph R. Biden Jr. had a task force write a 110-page policy document for his White House bid.

Now, Vice President Kamala Harris does not have a policy page on her campaign website.

A last-minute campaign born of Mr. Biden’s depreciated political standing has so far been running mainly on Democratic good feelings and warmth toward Ms. Harris, drafting off legislation and proposed policies from the man she is hoping to succeed.

Democrats’ problem for most of this year appeared to be Mr. Biden himself, rather than his policies. For more than a year, as his poll numbers sank, his aides and loyalists insisted that his legislative record and priorities were viewed favorably by Americans and would ultimately carry him to another term.

Ms. Harris is now testing that original theory — but with a younger, more spirited messenger.

On policy, she has essentially cherry-picked the parts of the Biden agenda that voters like most while discarding elements like his “Bidenomics” branding on the economy. She has emphasized what allies call the “care economy”: child care, health care and drug prices, which directly affect voters’ lives.

The link to the whole article is above.  Didn’t Harris propose some kind of ban on high grocery prices?

As I said, you can talk about anything here, not just politics, but do not diss other commenters or your host, and BE CIVIL. (If you’re a newbie, I recommend reading the posting rules.

Have fun! I’m off to see the animals.

Male fireflies caught in an orb-weaver spider’s web start flashing in an unusual pattern, a deadly deception that seems to attract additional victims for the spider

The World Health Organization considers "gaming disorder" a condition, but researchers have now found that playing video games can boost well-being

Wildlife sightings were a bit slim in the bush this morning, but yesterday we had two great highlights: one was an invasion of our swimming pool area by a large breeding herd of nearly two dozen elephants, parched in the heat and eager to drink the water (which is unchlorinated and runs continuously over the pool’s far edge, where excess water fills a smaller pool from which the pachyderms drink). For that we didn’t have to leave the lodge.

The second was our third sighting of a leopard, as well as a new cat for me: the cheetah. We saw both cats within just an hour of setting off on our three-hour afternoon drive. All of these are documented below.

Before lunch every day, they set the tables and put out a plate of bread and rolls. I swear to Ceiling Cat that  the the vervet monkeys know when lunchtime is, and are aware of the tempting breadstuffs. This onr, whom I photographed before his Big Theft, ran into the dining room, and before anyone could stop her (I don’t know the sex, but without balls it seems to be a female), grabbed two pieces of bread, stuffing one in her mouth and holding the other in her hand. She then hied off and ran up a tree while the leader of a group of young Italian visitors, about to sit down at the table, yelled at the vervet. The leader then returned the plate to the kitchen, asking for a replacement (I wouldn’t have asked). The lucky primate then sat in the tree, stuffing herself with carbs.

After lunch the elephants began show up at the pool to drink, for the day was hot.The big one to the right is, I’m told, probably the matriarch of a breeding group that appears to be largely female (yes, elephants have, like all animals, only two sexes).

This gave one Italian visitor the chance to importune her boyfriend for the selfie of a lifetime:

The elephants started showing up individually or in small groups, so that eventually there were 21 of them, all vying to drink! They were of all sizes and ages, but so far as I can tell nearly all were female. Rosemary will, I think, do her best to verify or disconfirm this in the comments.

You can see the small runoff pool where most of the elephants drink, while the bigger one can reach their trunks into the larger and cleaner pool to the left (the regular swimming pool). It’s wonderful that the designers of this lodge provided for the elephants in this way:

All sizes were there; check out the little one under the matriarch. Its trunk could barely reach even the smaller pool.

Adult and infants get a drink of cool water:

What a sight! One of the employees told me that when it’s hot they often get this many elephants. The new human visitors to the lodge were stupefied at the sight.

As it was hot, some of them used the water to spray their backs, like this one. Many also fanned their blood-rich ears to cool off. And they clearly enjoyed playing in the water. One of them even blew bubbles into the small pool.

Within the first two hours of the afternoon drive yesterday, we saw two rare species of cat. The first was the same leopard we saw yesterday, now resting on the ground and apparently unperturbed by our vehicle:

Soon thereafter, our vehicle, which held eight plus local driver/guide Dan (two Italians, a family of four Frenchmen, and two Americans, including me and an astronomer from Baltimore), came upon a great species The French paterfamilias was good at spotting animals, and cried out late in the afternoon. He had seen something in the distance lying atop a large, defunct termite mound.

This is what it was:

Yep, a hard-to-find cheetah (Acinonyx jubatus), the world’s fastest land animal. How fast is it? As you can imagine, its flat-out speed is hard to measure, but it’s about a mile a minute, attaining this speed from a standstill in just a few seconds. Wikipedia says this (bolding is mine):

The cheetah is the world’s fastest land animal. Estimates of the maximum speed attained range from 80 to 128 km/h (50 to 80 mph).  A commonly quoted value is 112 km/h (70 mph), recorded in 1957, but this measurement is disputed.  In 2012, an 11-year-old cheetah from the Cincinnati Zoo set a world record by running 100 m (330 ft) in 5.95 seconds over a set run, recording a maximum speed of 98 km/h (61 mph).

Cheetahs equipped with GPS collars hunted at speeds during most of the chase much lower than the highest recorded speed; their run was interspersed with a few short bursts of a few seconds when they attained peak speeds. The average speed recorded during the high speed phase was 53.64 km/h (33.3 mph), or within the range 41.4–65.88 km/h (25.7–40.9 mph) including error. The highest recorded value was 93.24 km/h (57.9 mph)

. . . Cheetahs have subsequently been measured at running at a speed of 64 mph (103 km/h) as an average of three runs including in opposite direction, for a single individual, over a marked 200 m (220 yd) course, even starting the run 18 m (59 ft) behind the start line, starting the run already running on the course. Again dividing the distance by time, but this time to determine the maximum sustained speed, completing the runs in an average time of 7 seconds. Being a more accurate method of measurement, this test was made in 1965 but published in 1997. Subsequently, with GPS-IMU collars, running speed was measured for wild cheetahs during hunts with turns and maneuvers, and the maximum speed recorded was 58 mph (93 km/h) sustained for 1–2 seconds. The speed was obtained by dividing the length by the time between footfalls of a stride. Cheetahs can go from 0 to 97 km/h (0 to 60 mph) in less than 3 seconds.

I think the one we saw (below) is a female though I couldn’t see teats. But testes should be visible if it were a male. It is slim and graceful, much thinner than the leopard shown above. Its figure shows the need for speed:

More from Wikipedia:

The cheetah lives in three main social groups: females and their cubs, male “coalitions”, and solitary males. While females lead a nomadic life searching for prey in large home ranges, males are more sedentary and instead establish much smaller territories in areas with plentiful prey and access to females. The cheetah is active during the day, with peaks during dawn and dusk. It feeds on small- to medium-sized prey, mostly weighing under 40 kg (88 lb), and prefers medium-sized ungulates such as impala, springbok and Thomson’s gazelles. The cheetah typically stalks its prey within 60–100 m (200–330 ft) before charging towards it, trips it during the chase and bites its throat to suffocate it to death.

What a lovely cat!

Now birds. Rita and Martim, as well as Dan, identify the large woven nests below as the product of the red-billed buffalo weaver (Bubalornis niger), a denizen of dry savanna. Here are three colonial nests in one tree, a tree with bark partly removed by elephant scratching (reddish area near the ground).

Wikipedia describes the nests:

Red-billed buffalo weavers breed in colonies. The nests are composed of an enormous mass of thorny twigs. These twigs are divided into separate lodges (compartments), each with multiple egg chambers. Each chamber has a smaller nest, typically built by the female (unless they are part of a cooperative breeding colony). The smaller nest is composed of grass, leaves, and roots. The whole nest is usually found in a thorny tree or in a windmill near areas inhabited by humans.

Two ways of looking at zebras:

To our best knowledge, as I’ve reported several times, the stripes evolved mainly as a deterrent to biting flies, which simply don’t like landing on striped substrates. They don’t seem to be any kind of camouflage or a deterrent to predation by carnivores.

. . . and a blue wildebeest:

Now from this morning.  These holes appeared overnight in the packed-earth parking lot, and we were told they were made by termites. I’m not sure what’s going on here, but I have inquired of an entomologist:

It was chilly and partly cloudy this morning, and this is an unmanipulated shot of the bush, which really is a black-and-white view at sunrise:

Pickings were slim on this morning’s drive (this is why you must stay at a place like this for, I think, at least four days).  Dan livened things up by propping up the skull of a dead hippo (I showed the skeleton before). He said this hippo had been badly mauled in a battle with another hippo, and died from bleeding out:

We had a rare “sunupper” today (the coffee we get near the end of a morning’s drive): we got to get out of the car and drink our java right near wildlife: a trio of giraffe. They were quite curious about us and looked at our group of nine intently for a long time:

Now that is what I call a coffee break!

Nearby, concentric species of dung: the darker and smaller droppings from a zebra surrounded the larger brownish ones from an elephant:

Every day we see one ostrich, and it’s always crossing the road. One might think it was confecting a joke:

Finally, Dan spotted rhino tracks (see below) and spent a long time trying to find rhinos for us. I’d already seen one, but as the longest resident of the lodge now—I’ve been here four days—none of the others had. Dan always tries hard to find hard-to-see species, but despite his getting out of the car and combing the bush, we found nada except for these prints:

But I have two more 3-hour drives (the animals I have yet to see include the Cape buffalo—my last of the Big Five—a hippo out of water, and the lilac-breasted roller (Coracias caudatus), one of the world’s most beautiful birds. I’ve actually seen the species twice, but they always fly away before I can take a photo. Here’s a shot taken from Wikipedia, as I doubt I’ll be able to photograph one properly: they’re not uncommon, but are also skittish:

The caption says that this one was photographed at Kruger National Park, which is right next door.

Charles J. Sharp, CC BY-SA 4.0, via Wikimedia Commons

Astrologists claim to be able to use the motion of the planets and stars to make predictions about people's lives, but a detailed study has found that they rarely even agree with each other

The totemic climate goal of keeping warming below 1.5°C above pre-industrial levels is essentially impossible at this point

Meanwhile, in Dobrzyn, Hili is concerned about health and safety:

Hili: You have to remove these roots.
A; Why?
Hili: Because somebody might stumble on them.

Hili: Musisz usunąć te korzenie.
Ja: Dlaczego?
Hili: Bo ktoś może się o nie potknąć.

Electrons that appear to be undetectable when analysing materials could be responsible for exotic properties, such as high-temperature superconductivity

Nature Reviews Cancer published a propaganda piece disguised as commentary promoting "integrative oncology," or what I like to call "integrating" quackery with oncology.

The post Revisiting “integrative oncology”: The battle to integrate quackery with oncology continues first appeared on Science-Based Medicine.

Today’s post covers the drives yesterday afternoon and this morning. Don’t forget to click the photos to enlarge them. And we saw another leopard!

I won’t put up a link or the Latin binomials for animals I’ve done that for already.

At lunch yesterday a vervet monkey (Chlorocebus pygerythrus) somehow found its way into the dining room and made for my plate (I was writing on this site in the adjacent room). But I’d eaten all my lunch, and so it thrust its hand into my water glass and licked off the drops (much like the black cat Toon in Amsterdam).  Vervets are social primates that range widely in East and South Africa, and have been extensively studied by biologists. Here’s a photo of the little guy, who was adorable but skittish:

Another day, another herd of impala, perhaps the most common antelope in the reserve. The males are the ones with horns, but they are very skittish and I’ve had trouble getting a front-on picture of the impressive males. I’ll try again this afternoon.

We’ve not seen many common ostriches in the park—just this one. Like the one near the Cape of Good Hope, it crossed the road, giving rise to an obvious joke:

A couple of elephants yesterday afternoon. It’s amazing to come upon one of these all of a sudden; sometimes I can’t spot them until we’re very close to them, as they often stand still.

A blue wildebeest, one of only two sister species in the genus Connochaetes, the other. being the black wildebeest. Both are mammals formerly known as gnus.  I asked our guide and driver, Dan, why this one let us get to close to him. Dan replied that this wildebeest was an old friend of his.

Wildebeest poop: extraordinarily small (about goat-poop sized, or the size of blueberries) for an animal this large. I’m told that this is because wildebeest have the four classic stomach compartments of many ruminants, and thus digest the short grass they eat very thoroughly, leaving only small, hard remnants of their food.

In contrast, elephants have poor ability to digest grass and foliage, and their droppings are huge, as we discover when we walk to and from our tents (the camp is crawling with elephants night and day). I’m trying to make a photographic collection of animal droppings for your delectation.

Mother and baby elephant:

Surprised by another elephant standing behind a tree:

A giraffe stood nearby as we had our “sundowner” drinks outside the vehicle. Some misguided zoologists have revised the single species Giraffa camelopardalis into four species based on genetic differences alone.  Since no two of them occur in one locality, one can’t use the biological species concept, but my guess is that there’s only one species of giraffe and all the subspecies would interbreed and produce fertile hybrids if they occurred in one locality (see posts here and here).

And two sundown photos of the giraffe:

We left this morning heading for a pride of lions that had been spotted, but when Dan got out of the vehicle to look for them in a ravine, he accidentally spooked them. But we had some serendipity: he saw a leopard sleeping in a tree above him, (the guy can find stuff, I tell you). We maneuvered around the other trucks, which didn’t seem to disturb the cat, until we were right below it.

It looked comfortable as hell, with its legs hanging down as it snoozed away. Two leopard spottings in two days: that’s fantastic.

On the way out, the ever-vigilant Dan, who was driving, nevertheless spotted some leopard tracks in the sand. He circled one of them for me:

A female greater kudu (Tragelaphus strepsiceros) either urinating or defecating. They’re relatively uncommon, so I may not get another picture. I’ve put a Wikipedia picture of the male below mine:

A photo of a greater kudu male from Wikipedia. Its spiral horns are striking:

This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license. Attribution: © Hans Hillewaert

This is more of less what “the bush” looks like around here, though this patch has a bit more trees than usual. It’s dry as it’s winter, and the rains come in summer; but this year summer was extraordinarily dry and the animals therefore stressed for food.

A panoramic shot of the bush. Click to enlarge:

h/t: Rosemary for IDs and information

 

Galaxies are some of the largest clearly defined structures in space. There are trillions of them, and many are clustered around each other. But how does that clustering affect them? That’s been a question for a while, and older papers have yielded contradictory results. Now, a new paper analyzing millions of galaxies from researchers at the University of Washington, Yale, and several other institutions shows a clear pattern that had been debated before – galaxies surrounded by other galaxies tend to be larger.

The path to that conclusion was a long one. Several other surveys showed that galaxies in “dense environments” were both larger and smaller. However, these studies were only conducted using a relatively limited dataset of hundreds or thousands of galaxies. So, the researchers in the new paper, led by Aritra Ghosh, a postdoc at UW, thought, “Why not get more data?”

So they did, using the Subaru telescope’s Hyper Suprime-Cam Subaru Strategic Program. This survey captured high-quality data on millions of galaxies for the first time, so the researchers were able to select 3 million galaxies with the best datasets from the cream of the crop.

Massive datasets on galaxies are becoming more common – Fraser discusses another survey of millions of galaxies.

They then drew “circles” of about 30 million light-years around each of the three million galaxies and assessed how densely packed their local neighborhood was. Statistically, the correlation was obvious – galaxies in more dense spatial neighborhoods were larger than their more isolated cousins. 

Saying the researchers drew circles around 30 million galaxies isn’t accurate, though – they used one of the myriad new machine-learning tools popping up in the astronomical community. This one, called the Galaxy Morphology Posterior Estimation Network, or GaMPEN, was the focal point of Dr. Ghosh’s PhD thesis at Yale. It specializes in estimating galaxy size and accounting for uncertainties in the measurement.

With the tool’s results, the question became, what does this mean? The idea that galaxies are larger in dense areas doesn’t fit well with astronomers’ current conception of how galaxies form. So, it’s time for a new theory to fit the data Subaru has collected, and the paper has analyzed.

Fraser discusses globular clusters, one of the dense states galaxies can find themselves in.

Several theories put forward in a press release could explain the observations. One is that densely clustered galaxies are simply larger from the start. Another is that perhaps they are more effective at merging with closely proximate galaxies to create larger supergalaxies than the two originals.

A third, more intriguing possibility is that dark matter might be involved. But since scientists still don’t understand what dark matter actually is, this is akin to waving a magic wand to explain data that otherwise doesn’t fit the cosmological model.

Regardless of the reason, the study is an excellent example of how large datasets and AI-enabled tools will change astronomy shortly. In some cases, it will confirm existing theories, and in some cases, like the relationship between galaxy density and size, it will call for a new theoretical framework. Either way, it’s exciting to be around for all these new discoveries, whether AI-powered or not.

Learn More:
UW – Galaxies in dense environments tend to be larger, settling one cosmic question and raising others
Ghosh et al. – Denser Environments Cultivate Larger Galaxies: A Comprehensive Study beyond the Local Universe with 3 Million Hyper Suprime-Cam Galaxies
UT – This Distant Galaxy Cluster is Totally Relaxed, Unharassed for a Billion Years|
UT – A Collision Between Gigantic Galaxy Clusters. Too Big, Too Early

Lead Image:
Image of Abell 2218, a dense galactic cluster approximately 2 billion light-years from Earth.
Credit – NASA/ESA/Johan Richard

The post Galaxies in Dense Environments Get Larger appeared first on Universe Today.

Areas of space have wildly different temperatures depending on whether they are directly in sunlight or not. For example, temperatures on the Moon can range from 121 °C during the lunar “day” (which lasts for two weeks), then drop down to -133 °C at night, encompassing a 250 °C swing. Stabilizing the temperature inside a habitat in those environments would require heating and cooling on a scale never before conducted on Earth. But what if there was a way to ease the burden of those temperature swings? Phase change materials (PCMs) might be the answer, according to a new paper from researchers at the Universidad Politecnica de Madrid. 

PCMs have been known for some time and are currently used in several industries, including batteries, solar power plants, heat pumps, and even spacecraft. Perhaps most interestingly, they’ve been used to cool and heat the interiors of buildings on Earth.

They do so by absorbing heat during the hot parts of a period (whether a day or season) and emitting that heat in the cooler parts of a later period. They act like a giant thermal “sink,” making it take longer to heat or cool and providing insulation to anything it surrounds.

Two-bit DaVinci explains how PCMs work on terrestrial houses.
Credit – Two-bit DaVinci YouTube Channel

Another way to think of this is through the concept of thermal inertia. When an object, like a building, is in the Sun, it is directly impacted by the Sun’s rays, causing it to heat up. Alternatively, if it is no longer in the Sun but still contains a lot of thermal energy, it will start radiating some of that heat away. In vacuums, radiative energy is transmitted through infrared light like space.

PCMs have such large thermal inertia because they either absorb or emit lots of energy as they change between phases, such as between solid and liquid or liquid and gas. For example, the paper describes using n-octadecane as one of the PCMs being considered. It switches state around 28 °C, slightly above room temperature. Which makes it perfect for holding a room at right about that temperature.

Changing the temperature of something built with PCMs is much more complicated, and that challenge can make it easier to regulate the temperature inside a space habitat. The researchers modeled what would happen if a space habitat were built with PCMs inside the walls, and they found a significant decrease in the heating and cooling required to keep the habitat within the temperature range of being comfortable for humans.

Thermal control is one of the aspects of a self-sustaining space habitat, as Fraser discusses with Dr. Annika Rollock.

Other factors were included in the calculation, such as the reflectivity of the outer surface of the wall and the part of the solar cycle the Sun was experiencing. However, the authors found that given optimal conditions; designers could completely passively heat and cool a space habitat using only PCMs.

That is a pretty impressive feat, though the optimal conditions are improbable to ever happen in practice. Still, any energy savings the materials might provide will be welcome on a habitat that will likely be energy-starved when it starts. However, many different ideas exist for how those habitats should be built, including using regolith on the Moon. It is unclear how feasible it would be to include PCMs in cave walls or other structures involving local materials. The sheer amount of PCMs necessary to thermally control a massive human habitat might also be prohibitively expensive to launch at current prices.

However, materials keep improving, and there are obvious advantages to using these materials in this context. While they might not be integrated into some of the early habitats humanity builds in space, they will undoubtedly be used in future ones, and this paper is one step towards that.

Learn More:
Kachalov et al – Preliminary Design of a Space Habitat Thermally Controlled Using Phase Change Materials
UT – The Future of Space Colonization – Terraforming or Space Habitats?
UT – Where Could Humans Survive in our Solar System?
UT – Watch a House-Sized Space Habitat (Intentionally) Burst

Lead Image:
Artist’s depiction of a habitat on the Moon.
Credit: ESA/Foster + Partners

The post Specialized Materials Could Passively Control the Internal Temperature of Space Habitats appeared first on Universe Today.

Meanwhile, in Dobrzyn, Hili – like many cats – is bemused:

Hili: It’s difficult to figure all of it out. A: Figure out what? Hili: I told you – all of it.

 

Hili: Trudno się w tym wszystkim zorientować.
Ja: W czym?
Hili: Powiedziałam, że we wszystkim.