Kangaroos are predominantly left-pawed according to a June 18, 2015, study of Eastern Gray and Red kangaroos published in Cell Biology by Andrey Giljov et al of Saint Petersburg State University.
The pawedness of these bipedal marsupials was observed during eating and grooming. A connection to walking on two legs for a paw dominance was noted. Bipedal wallabies (shown below) also showed a left-hand preference. The wallabies used their left paws for fine motor skills and right paws for strength. Quadruped marsupials like tree kangaroos did not show a predominant paw.
The researchers were surprised to find a dominant paw at all since marsupial brains do not have a corpus callosum, the connecting tissue between the two sides of the brain which humans and many other placental mammals have.
This Smithsonian article describes the kangaroo research as being useful to understanding dominant handedness in humans. Additionally, left-handedness in humans correlates with less specialized brains.
Any southpaws out there among PEOTSers? Maizie is right-pawed and I am right-handed.
Chirality yours,
Steph
With all things liquid in mind today, here's the link to Science Friday's blog's picture of the week and text: Ferrofluids.
The blog text, reproduced here, includes possible practical applications to directly targeting cancer tumours:
"Magnets are pretty cool. The way they attract and repel—it’s like magic. But a liquid magnet? That’s even cooler. Called a ferrofluid, such a liquid is comprised of tiny magnetic particles between 10 and 15 nanometers wide suspended in a fluid. In the presence of a magnetic field, the material ebbs and flows according to where the field tells it to go. Instead of an amorphous puddle, it can pool into some funky, spikey shapes—making for some amazing pictures like the bizarrely beautiful one above."
"This particular photo (above) shows a single drop of a ferrofluid that’s made from magnetic iron particles suspended in oil. To form that pattern, Felice Frankel, a photographer and researcher at MIT, placed a small, three-centimeter-wide drop on a glass slide. Underneath are seven round magnets—like the kind on your refrigerator—arranged so that six of them surround the last. Each magnet forces the particles in the liquid to align with the magnetic field, forming the spikes seen in the photo."
"To add some color, Frankel inserted a yellow Post-It note in between the magnets and the slide. The image is part of an exhibition at the MIT Museum on communicating science through photography, which is showing from now through March 2016. (Frankel is also co-instructing a course on science photography.)"
"Ferrofluids, though, have been around since the 1960s. And they don’t all just sit around, looking pretty. For example, they’re widely used as nearly frictionless seals to maintain a vacuum while still allowing for moving or rotating parts. Some computer hard drives, for instance, rely on a magnet to hold a ferrofluid seal in place, which keeps the disk protected in a clean, dust-free vacuum. Because the ferrofluid is liquid, the disk can spin freely with hardly any friction."
"Understanding ferrofluids can also inform research into fighting diseases like cancer. No, doctors won’t be infusing patients with that black liquid. The idea is to inject magnetic nanoparticles that help deliver tumor-destroying drugs. Their movement through liquids like blood could be controlled by a magnetic field, similar to particles in a ferrofluid."
"By targeting tumors directly, you can avoid collateral damage to healthy cells. (Cancer drugs tend to be quite nasty and can cause side effects.) But getting those particles to accumulate at the tumor isn’t easy. “That is the biggest challenge in nanomedicine today,” says Carlos Rinaldi, a professor of biomedical and chemical engineering at the University of Florida."
"One potential way to deliver drugs is with tiny spherical containers called liposomes, which are made of the same stuff as a cell’s membrane. You can fill the liposomes with drugs and attach the nanoparticles on the outside. Once the liposomes reach a tumor, the doctor turns on a magnetic field, which flips the nanoparticles back and forth, like how a compass needle goes crazy when next to a magnet. All that motion generates heat, which melts the liposome and releases the drug."
"Or, instead of riding in a liposome, the drug could chemically bind to the nanoparticles. The magnetically induced heat would then break that bond and unleash the drug. The heat itself could also help kill the tumor, as some drugs work better at higher temperatures."
"Saving lives drives much of the research in ferrofluids, of course. Still, you can't discount their mesmerizing patterns and behaviors. After all, that’s what inspired Rinaldi to study ferrofluids in the first place. "The idea that you can use a magnet to manipulate a liquid—to me, that's just so cool," he says."
And if you want to make your own ferro-fluid, here's 4-minute video:
Fun with Ferrofluids: Making Your Own
Let me know how it turns out; I don't want to see any more liquids right now,
Steph
Trilobite bottoms (or pygidia) are found in sedimentary rocks, evidence of the molting life cycle of these intriguing fossils.
The fossilized remains of these primarily Paleozoic fossils sometimes show the molting process quite distinctly:
Rather than finding the whole fossil with its namesake distinct three parts
sometimes only the trilobite bottoms are found:
Molting, molting molting. . .
When first searching the web for trilobite bottoms here's the image that popped up first:
Trilobite bottoms came up as a topic for this week's PEOTS as I was planting artichoke plants (nasty, spiky, weedy looking things):
It was a small leap from artichoke bottoms (which are, of course, also known as hearts)
to trilobite bottoms. . . .
Looking forward to Tri lo bite of the artichoke bottoms soon!
Steph
And for those science grads:
Cherry blossom stones (or "pinite") are a complicated group of six cordeirite crystals surrounding a central indialite crystal which have all then been replaced by muscovite in a second metamorphic event. I knew I muscovite about them after reading about them for the first time today.
The structure of the stones is shown in this illustration (please forgive the 'intergorth' typo:
The dumbbell structure including the central indialite crystal creates these intriguing stones which are not fossils:
The type locality is near Kyoto, Japan, of all perfect prefecture places. And these stones are found in a hornfels (metamorphosed shale or mudstone) matrix.
So much change in temperature and pressure in those metamorphic rocks to create these delicate hexagonal structures! The end result are muscovite replacement crystals of these cordeirite-indialite crystals all on the hornfels rock.
Chemically, indialite is a magnesium aluminosilicate mineral (Mg2Al4Si5O18). Cordierite is an iron magnesium aluminosilicate mineral ((Fe,Mg)2Al4Si5O18).
Have you heard of cherry blossom stones before? Does the complex interrelationship of the host rock, original crystal structure of two different minerals then replaced by another mineral in a hexagonal structure make you say "Wow?!"
Whoa. Wow,
Steph
New canine mountain friends on a perfect Colorado Day:
We said our Colorado au revoirs this weekend. . . ZOË is Addis Ababa bound, home-made injera sourdough flat bread in hand ;-). A most excellent adventure until September, 2017; Colorado peeps will miss you! Excited to hear about your grand adventure!
The square-wheeled bike at Macalester College in St. Paul, Minnesota, is the inspiration for this week's PEOTS.
Mom, Zoë, and I had fun riding the blue-wheeled trike along the catenary curves:
It really is a smooth ride and one does not feel the bumpiness of a washboarded dirt road as the length of the squares' sides roll perfectly into the endpoints of the catenaries. It is intriguing that quarter circles were used to move large square blocks of marble around the pyramids.
So all those jokes about square wheels really aren't quite as funny any more. . .
Jan's questions about washboarding on dirt roads dovetails into our square wheel discussion:
This article discusses why wash board ripples or corrigations form whenever a vehicle travels more than 5 miles (8 km) per hour over a gravelly or sandy surface. My best guess as to why they extend over the whole road is that drivers try to avoid existing ripples, thereby inevitably creating more right next to them.
The most mysterious part of the researchers' results is that the ripples appear even when the springy suspension of the car and the rolling shape of the wheel are eliminated.
Letting some air out of tires when going over washboarded roads approaches traveling over catenary-like bumps with a square-ish tire.
What other questions spring from square wheels, catenaries (which makes me think of a cat who ate the canary) and washboarded roads?
Sponge Steph, Square Pants
We are taking a detour from the traditional PEOTS meanderings to our return road trip from The Cities through southwest Minnesota:
We had a great time in Blue Earth as Maizie frolicked beneath the giant's size 78 shoes.
Of course, in all the cement arrow searchings, this was the definite highlight. Congrats to Zoe, Macalester Class of 2015. May your meanderings in Ethiopia be long, safe, and fruitful!
What a great, l o n g trip it's been! Thelma and Louise-ing it. . .
Very bittersweet moments here,
Steph
Road tripping here in search of large cement arrows. ;-) Perhaps you can tell where Mom, Maizie and I have been from a few photos and knowing what time of year it is:
And for this shortened week, enjoy Ten pictures that will "make you want to become a geologist."
Checking my quiver carefully.
Enjoy,
Steph and Co
I'm short on time this week so will present you with this link to a 100-year-old image of a cat's tongue in today's Science Friday :
The text from the NPR Science Friday link is also reproduced below:
"You’re looking at a 3 mm-wide section of a cat tongue more than a century old. David Linstead’s captivating image was a winner in this year’s Wellcome Image Awards.
"The picture is actually a composite of 30 polarized light micrographs, or photographs taken with a digital camera and a microscope. A retired cell biologist, Linstead used microscopes professionally as a research tool, and later formed his “hobby addiction” after purchasing one, then another, and still more microscopes on eBay (also his go-to source for specimen-plated slides like this one). His particular interest is in combining modern illumination techniques with vintage slides dating from 1860 to 1910, the heyday of slide-making."
“The original person who made this slide likely had no thought of how it would be used in 100 years’ time,” says Linstead, who estimates that it dates back to the 1890s. “But when I saw it, I immediately knew it had great potential.”
"The promise lay in the way the slide was prepared. It wasn’t stained, for one, which allowed the cross-section’s true colors to be observed with polarized light—a feature of most cutting-edge microscopes of the Victorian age. Those yellow streaks, for instance, are horizontal muscles, and the sparse purple ones are muscles that run vertically."
"Furthermore, the original tissue had been injected with a dye—probably a solution of iron salt in warm gelatin, Linstead surmises—to make the capillaries, seen here as black squiggles, apparent. (The only alteration Linstead made to the image was to Photoshop the background gray, because the original magenta “didn’t go well with the rest of the slide.”)"
"Colors aside, the serrated ridge may be the most intriguing aspect of this picture. Those rough bumps, or papillae, are the reason that a kitty’s tongue feels like sandpaper when it licks you. When a cat grooms herself, the papillae
act like a comb to remove dirt and loose hair. But they also serve a grislier purpose: rasping meat off of bones. Fluffy might look sweet, but Linstead’s striking image is a reminder that the cat napping on the couch is a fierce predator."
The other 19 images in this year's Wellcome awards, including these specialized Purkinje brain cells, are also quite intriguing.
Let me know what you think. . .Hoping the cat doesn't have your tongue, er, thumbs.
[With fond thoughts of Lego's Noosie.]
Digitally,
Steph
Purkinje cells showing well-defined organization:
On Monday, April 27, 2015, the U. S. Department of Health and Human Services decreased the recommended amount of added fluorite in drinking water to about half the original recommendation. It is the first change in the recommended amount since 1962.
The main documented side effect to over-fluoridation is fluorosis, a condition marked by white marks on the teeth. There are proven great benefits to low fluoride amounts to decreasing dental caries. Most people in the U. S are already getting fluoride directly on their teeth in the form of toothpaste and dental rinses. The NPR link above notes some believe fluoridation at higher levels is linked to other problems including thyroid issues, skeletal fluorosis, and ADHD.
Much of the western world has already eliminated or decreased fluoride amounts in water supplies. There are some areas of the world that have naturally occurring fluoride which is over 1.5 mg/l (See world map here.) The high fluoride levels are linked to types of granite with the naturally occurring fluorite mineral (the purplish mineral in the pinkish granite below):
The mineral fluorite, CaF2, is a member of the halide sequence.
And, of course, fluorite is the namesake poster child for fluorescence under ultraviolet light:
I am curious to hear about your views on the fluoride controversy. What is yours? Surely, the decreasing of the acceptable level by half is significant.
Going with the fluo,
Steph
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