Good and unexpected place



Good and unexpected place



How would you measure the water level in a river? A float? A pressure sensor? Something else? Yesterday, I discovered how it’s done here on the Potomac, and it turned out to be not at all what I had imagined. The USGS engineers are great—they educate passersby by posting a diagram of the operation.
A tube is lowered into the river through which air is supplied in bubbles (through a bubble orifice). A special pressure sensor (Pressure Transducer) measures the air pressure in the tube that is necessary to release the bubbles from it. The higher the water level in the river, the more pressure is required to push the air into the water—because the air pressure in the tube is directly related to the depth of the water (according to Pascal’s law). The bubble method works well even if there is floating debris or ice in the river, which may interfere with other sensors (such as ultrasonic ones). Since the sensor does not contact the water, it always remains dry and clean. Additionally, to prevent data distortion, the system includes an air dryer (Air Dryer), which removes moisture from the air and prevents condensation.
The accuracy of such systems is 1-2 cm in water level for rivers with shallow depths.
Interestingly, the readings are transmitted not through the mobile network, but via satellite.

While walking with Yuka, suddenly the owner falls on his knees and digs around in the grass for a while. That’s when I found a firefly and wanted to capture it lighting up. The firefly Photinus pyralis is quite common here, but I never got around to studying it closely.
Interestingly, the females of another genus of fireflies, Photuris, use the flashes of Photinus males to locate and eat them. It has been discovered that the females acquire special steroids called lucibufagins from their prey, which repel spiders.
(While figuring this out, I learned something new. Luciferase, an enzyme responsible for the glow, is extracted from these fireflies. It’s named after the word Lucifer, Latin for “light-bearer.” Interestingly, Greece also had its Lucifer, “light-bearer,” known as the god Phosphorus. Incidentally, the element Phosphorus was discovered by alchemist Hennig Brand through the evaporation of urine. He named the discovered element phosphorus mirabilis, from Latin meaning “miraculous light-bearer.” This just shows how many things in the world are connected.)


#science Today I found another tick on me; it didn’t have time to latch on, but did manage to bite. And like before, I suffer from these tick bites being very itchy and taking a long time to heal. A couple of times because of similar symptoms I ended up in Emergency, where I was diagnosed with Lyme based on symptoms and put on doxycycline, but later tests did not confirm Lyme, though I already took the doxycycline. And if there was anything, it’s long dead. Question is, why do ticks love me so much.
I just found an interesting scientific article about this. “Hypersensitivity to Ticks
and Lyme Disease Risk” (link in comments)
The authors say that many people living in areas with a high prevalence of tick-borne diseases such as Lyme develop a more acute reaction to tick bites—redness and severe itching, a dermatological-hypersensitivity reaction—that’s exactly my case. They analyzed 1,500 cases and concluded that the more frequent a person’s itching after a bite (more than 3 times a year), the lower their chance of contracting Lyme disease—the risk was reduced by about 7 times (odds ratio ~ 0.14, p=0.01).
They write that this is linked to the fact that the itching helps to notice the tick sooner, consequently – remove it faster and prevent the infectious agent from entering the body (borrelia is not transmitted immediately, but after 1–2 days). There may also be immune mechanisms that interfere with the tick’s feeding and transmission of borrelia.
Conclusion: Recurring reactions to tick bites (itching + redness) create a kind of “anti-tick” immunity. This reduces the risk of contracting Lyme disease, and likely, could be the basis for developing a vaccine against tick pathogens. Quite intriguing, because such medications exist for dogs (full protection against ticks), but haven’t been invented for humans yet.

I am looking at photos and reading material about the Milky Way and noticed that the word galaxy (any) essentially means “milky” from Greek. Κύκλος Γαλαξίας. Essentially, lac from lactose, and gala from galaxy essentially come from the same Proto-Indo-European ģlákts. Unexpected.

I returned from Mexico — visited Xplor Park by Xcaret in Riviera Maya. The park is already 18 years old, but damn, it’s an engineering feat, not just a park. As an engineer, I was walking around with my mouth open.
The park is the size of Moscow’s “Neskuchny Garden”. A significant part consists of kilometers of natural karst caves, formed millions of years ago at the site of the Chicxulub impact crater (the very one that ended the era of dinosaurs). Above the caves are dense jungles. High above the jungles — kilometers of zip lines. The water in the caves is from a natural underground stream, which is filtered through limestone plus some technical structures. Bats fly around, but obviously, they are not wild and are working for food. No wildlife (other than tourists and bats) is present, so it’s pretty well isolated from the outside world. In these kilometer-long caves, completely covered with stalactites and stalagmites, we swam, rafted, and even drove through in amphibious vehicles with gasoline engines (meaning, the ventilation is well-thought-out).
In front of us, three Mexican women failed to control their vehicle and crashed into a tree. Literally — the front wheels of the buggy were above my head. We picked them up walking along the track, sat them back, and about 5-10 minutes down the road, park workers took them away. The girls have something to remember.
The ticket includes a very, very good buffet restaurant. But pictures are essentially a must-buy — a very thoughtful system designed to extract about 100 dollars from a visiting family. Helmets are embedded with a chip, the system classifies the pics on the fly, and at the exit, you can see all your photos and buy them right there. And on the way back to the hotel, you can post on Facebook or Instagram.
Well, we’re back home now, back to work from Monday.
















Here in Playa del Carmen, there are about a dozen abandoned Maya-era buildings that you can climb over and into, of course free of charge and at any time. Inside one of them, in a small room, I found interesting termite mud tunnels, which I had never seen in person before.





On the shore, a lone woman was seen engaging in an unequal battle with the world ocean. Armed with a shovel, she heroically moved the sargassum two centimeters to the left, apparently to a place designated for them by feng shui. To the left and right to the horizon—nobody.
Anti-swimming moat

I walked with Yuki and he passed by a little deer less than a meter away without noticing. This is a dog that can smell a hare running past the house by scent. It turns out that fawns are born almost odorless, and this saves their lives.
It is precisely because of their nearly complete lack of smell that does leave their young alone for extended periods. Mothers leave fawns for several hours at a time during the first weeks after birth so that their own smell does not transfer to the babies. During this time, the mother returns several times a day to feed her young. Although she may not be continuously near the fawn, she is usually somewhere close by, and surely worried about seeing us around her baby.
However, it’s not only the lack of smell that helps fawns remain hidden from potential predators. The white spots on their fur are another protective measure. When a fawn walks, the spots may seem obvious, but when the mother leaves it to hide in tall grass or other covers, these spots mimic dappled sunlight falling on the forest floor, as noted by the Iowa Department of Natural Resources. Such spotted coloring, combined with the faint smell, makes it difficult for predators to find fawns. Typically, the spots disappear by winter when young deer are old enough to survive on their own.
It is said that fawns are born in late May-early June. Today is precisely June 4. They’re right on schedule!
Despite the fact that he is lying in the open sun in thirty-degree heat, overall, if necessary, he can move on his own. Fawns are born generally ready for life in the wild and are generally able to run immediately after birth (albeit poorly).