16 March 2018

A vampire overslept on this bench this morning

Image cropped for size from the original here.

"Brumation" illustrated

"Brumation is a term used to refer to dormancy of reptiles, which is metabolically somewhat different from mammalian hibernation.

The video above shows alligators lying dormant, not in tunnels in mud, but right in a frozen-over pond, with just their nostrils protruding above the ice.

If anyone has even the faintest doubts about the survival capabilities of this superpredator, this video should change your mind.

Meet the Denisovans - updated

Bence Viola from the Max Planck Institute for Evolutionary Anthropology in Leipzig discovered the tooth fragments together with Russian colleagues in the Denisova Cave in the Altai Mountains. Initially, he thought the inconspicuous-looking object was the molar of a cave bear. But when the remaining fragments of the tooth turned up, it became obvious that the researchers had found the tooth of a hominid. It was too large, however, to be from a modern man or Neanderthal. When the researchers finally succeeded in decoding the DNA of the tooth, their suspicion was confirmed: it hailed from a previously unknown early human species living in Asia at least 30,000 years ago.
More on the Denisovans:
Because of the cool climate in the location of the Denisova Cave, the discovery benefited from DNA's ability to survive for longer periods at lower temperatures.  The average annual temperature of the cave remains at 0°C, which has contributed to the preservation of archaic DNA among the remains discovered.  The analysis indicated that modern humans, Neanderthals, and the Denisova hominin last shared a common ancestor around 1 million years ago.  The mtDNA analysis further suggested this new hominin species was the result of an early migration out of Africa, distinct from the later out-of-Africa migrations associated with Neanderthals and modern humans, but also distinct from the earlier African exodus of Homo erectus.  Pääbo noted the existence of this distant branch creates a much more complex picture of humankind during the Late Pleistocene... David Reich of Harvard University, in collaboration with Mark Stoneking of the Planck Institute team, found genetic evidence that Denisovan ancestry is shared by Melanesians, Australian Aborigines, and smaller scattered groups of people in Southeast Asia, such as the Mamanwa, a Negrito people in the Philippines.
And what a superb cave; no wonder it maintained its real estate value for tens of thousands of years.  The narration accompanying the slideshow is concise and superb; this video will be of interest to anyone with even a smidgeon of curiosity about archaeology or human prehistory.

Addendum: To keep relevant material in one place, I'll insert here a post I wrote back in 2011 ("Denisovan genes as markers of migration") -

There's too much to cover here in a short post, but I'll sketch what I understand as the basics.  Denisovans were ?pre-humans/proto-humans of the genus Homo who died out as a species.  They were genetically distinct from us, but some of their genes are present in modern humans.  The distribution of those genes today is not random, as shown by the figure above.
“We haven’t been a very exclusive species, with a very narrow origin,” said Martin Jacobsson. Interbreeding with other members of the human family tree “is not a unique event. It’s a more complex story than we thought before.”

In a study published Oct. 31 in the Proceedings of the National Academy of Sciences, Jacobsson and co-author Pontus Skoglund searched through 1,500 human genome scans from around the world for genes found in Denisovans but not chimpanzees or Neanderthals.

While the previous finding of Denisovan inheritance involved analysis of ultra-high-resolution human genome scans, of which only a few exist, Jacobsson used low-resolution scans. These are more commonly available and allowed the researchers to detect Denisovan signals in genomes from mainland southeast Asia. A signal also appeared in South America, but Jacobsson said that’s probably a false positive.
I'm interested in the South American hits because of my belief in early colonization of the Americas from Oceania.  I believe there's good evidence that the chickens in Chile and Peru came from Polynesia in pre-Columbian times.

Further information at Ars Technica, via Right-reading.

DNA from another human-like primate, the Denisovans, lurks in modern genomes, too. A molar and a chip of pinkie bone found in a Siberian cave provide what little information we have about this species. DNA extracted from the fragments previously revealed cross-species breeding. Yet a new study in the journal Cell shows the ancient hanky-panky did not stop in Siberia: Humans who traveled across South Asia mated with a separate group of Denisovans, as well.

“This is a breakthrough paper,” said David Reich, who studies ancient DNA at Harvard University and was not involved with the study. “It's a definite third interbreeding event,” one that adds to the previously known Denisovan and Neanderthal mixtures.

Humans and Neanderthals divided into separate groups as far back as 765,000 years ago. Denisovans and Neanderthals were closer cousins who split more recently and then vanished — perhaps because we absorbed their lineages...

All groups studied, from British and Bengali people to Peruvians and Puerto Ricans, had a dense cluster that closely matched the Altai Neanderthals. Some populations also had a cluster that matched the Altai Denisovans, which was particularly pronounced in East Asians.
The surprise was a third cluster — not like the Neanderthal DNA and only partially resembling the Altai Denisovans. This, the authors concluded, was a second and separate pulse of Denisovan genes into the DNA blender.
More at the link.

14 March 2018


 Photo taken by Tobias Messerli in the Canton of Bern.  Awesome composition.

The ecology of driftwood

Logs the size of telephone poles drift along the shore of the Salish Sea. Erik Hammond turns the wheel of his aluminum skiff and closes in. He grabs his ax and towlines, then leaps atop the floating wood, much as his father did, and his father did before him. With the butt of his ax he drives anchor pegs into the choicest three and ties them to the stern... Hammond and Moore are beachcombers, or log salvors, based in Gibsons, British Columbia.. They are practitioners of an occupation once common on the Pacific Northwest coast...

Driftwood makes an enormous if underappreciated contribution to the food web connecting the forests and the sea... Driftwood, it turns out, is also rapidly disappearing...

Immense logjams and floating rafts of naturally occurring wood were once common and well-documented features in rivers and estuaries before they were cleared for navigation. The Great Raft on Louisiana’s Red River, perhaps the most famous, existed for an estimated 375 years before its removal in 1830...

Kramer’s research shows that driftwood serves as building blocks for stable sand dunes and spits in estuaries, providing an important buffer from rising tides and waves. But shorelines around the world—especially in developed, temperate zones—are now severely wood impoverished compared to their condition before human settlement. As rivers lose driftwood, water travels through faster and there is less time for nutrient cycling...
Excerpts from an interesting longread at Hakai Magazine.  The magazine has an abundance of articles on coastal science and societies.

The fate of golf balls in the ocean

About 1.2 billion golf balls are manufactured every year, according to a 2017 report in Chemical & Engineering News, and more than half may be lost in the environment. A New York Times story in 2010 reported that an estimated 300 million disappear each year in the United States alone. With many of the planet’s approximately 32,000 golf courses located beside the ocean, countless golf balls find their way into the water, where they sink and accumulate more rapidly than anyone is cleaning them up.

Weber, a grade 12 student, is doing her best, but is barely putting a dent in the collection of drowned balls. Just two weeks earlier, Weber and her father spent several hours snorkeling in the same cove and cleared the seafloor of about 2,000 balls.

Now, the ocean bottom is again awash with golf balls. “Big waves come through and uncover them,” says Weber, who started collecting golf balls here in 2016. “It can sometimes make what we’re doing feel futile.”..

They don’t just sit inertly on the seafloor, either. As Weber has documented, they corrode.

In fact, golf balls have been found in the stomachs of at least two gray whales found dead in Washington State—one in 2010, the other in 2012—though the balls were not identified as the cause of either death. Golf balls also appear in bird stomachs on occasion—something Steiner says he has seen scores of times while inspecting decayed albatross carcasses in the northwestern Hawai‘ian Islands. Golf balls may even find their way into birds’ reproductive tracts—in one documented case, a golf ball encased in shell was laid by a Canada goose.
More at Hakai Magazine.

Coming in November

13 March 2018

Potter wasp

Impressive not just for the "pot" but for the classical "wasp waist."  More info here.

Via the NatureIsFuckingLit subreddit.

TMI about wedges

This post will be of interest only to golfers.  I researched it after receiving this message in an email from a local public golf course advertising a preseason sale:
These $100 wedges are simply phenomenal and retailed in 2017 for $150. This is a great deal but stock is limited and includes:
50 degree F grind
52 degree F grind
54 degree S grind
56 degree S grind
56 degree F grind
56 degree M grind
58 degree M grind
60 degree K grind
60 degree S grind
60 degree M grind
I was gobsmacked by both the price and the degree of specialization.  I started playing golf 60 years ago using a set of clubs from Montgomery Ward comprised of a driver, 3-wood, putter, sand wedge, and 3- 5- 7- and 9-irons.  I later added and mastered an 8-iron for greenside play.   Wedges became a growth industry several decades later:
Since the mid-80s the number of wedges available to players has grown from 2 (pitching and sand) to 5 (adding gap, lob and ultra lob), most of which are now available in a wide array of lofts and bounces to allow a player to "fine-tune" their short game with the wedges that best meet their needs. In some cases, with the high degree of customization, companies have done away with the traditional names for each club, and instead simply label each club with its loft and bounce angles. A 52-8 wedge, for example, would have 52 degrees of loft and 8 degrees of bounce, generally placing it in the "gap wedge" class. Most players carry three or four wedges on the course, and sometimes more, usually sacrificing one or two of their long irons and/or higher-lofted fairway woods to meet the 14-club limit.
The degree of loft is relatively easy to understand, as per the graph embedded at the top showing relative trajectories for a Lob wedge (60-64 degrees), Sand wedge (54-58), Gap wedge (50-53), and Pitching wedge (40-48).

The "bounce" factor is more complex:

Bounce is the group name for the elements involved in sole design: the bounce angle, sole width, leading edge, rocker and camber of a wedge. Bounce, and specifically the bounce angle, is added to prevent a wedge from digging into sand or turf, stopping the momentum of the club through the ball. Wedges with minimal bounce will be better suited to players who sweep the ball, taking a shallower divot, firmer turf conditions (i.e. links courses)...
For "links courses" read "public golf courses where the turf bakes into concrete in the summer."

Only the most fanatic golfers will move onward to read about "grinds" in this article about Vokey wedges.  More at this interview with Bob Vokey at the Titleist website.

(The fonts got all mixed up in this post and I can't seem to fix the problem.  Moving on...)

Which U.S. household do you belong to ?

Golf Carts and Gourmets
Colleges and Cafés
Modest Metro Means
Status-Seeking Singles
Footloose and Family-Free
Settled and Sensible
Diapers and Debit Cards
Babies and Bliss
Kids and Cabernet
Digital Dependents
Full Pockets, Empty Nests
Town Elders
Generational Soup
Booming and Consuming
Birkenstocks and Beemers
Progressive Potpourri
Cul-de-Sac Diversity
True-Grit Americans
Countrified Pragmatics
Red, White, and Bluegrass
American Royalty
Tough Times
Tight Money
I guess our household is "Settled and Sensible."

Selections from a larger list of 71 categories developed by Experian, a credit data corporation, and published in Harper's under the much better title "Glass Menagerie."

Dwarf Kingfisher

Via the Pics subreddit.

Neonatal surgery without anaesthesia

In 1986, the world was shocked when reports of infants undergoing major surgery with out anesthesia arose in both the USA and UK. In the USA, mothers of two premature infants wrote letters to the medical journal, BIRTH, protesting the “barbarism of surgery without anesthesia.”..

Why did infants not receive anesthesia that was comparable to that received by an adult? In the following years, numerous books and articles were written on the subject . A survey of such literature reveals that the two repeatedly cited reasons were: 1. Infants do not have the capacity to perceive pain. 2. It is too risky to use potent anesthetics on infants, given the risk for cardiorespiratory compromise and death...

The 19th century surgeon was rough, having inherited an attitude of indifference to pain from the days predating anesthesia. It was said that the role of a surgeon was to preserve life and not to prevent the temporary pain of the experience. As such, the use of anesthesia was originally restricted to those considered sensitive, primarily the rich, white and educated women and children...

...one of the two consistently cited reasons for the withholding of anesthesia from neonates was the belief that infants are insensitive to pain. When the American Academy of Pediatrics released its statement on neonatal anesthesia in 1987, it cited the commonly taught rationale that “nerve pathways [in neonates] are not sufficiently myelinated to transmit painful stimuli or that neonates do not have sufficiently integrated cortical function to recall painful experiences... 
Continue reading at this submission to the Osler Student Essay Contest.

Cable cars as mass transit

Known as the Mexicable, the 3-mile, $90 million gondola system opened to great fanfare in late 2016, an ambitious effort to improve public transportation in this suburb of more than 1.6 million. Initially met with some doubts, it has since provided more than 5.5 million rides, with about 20,000 passenger trips on a typical weekday. It has also drawn praise for giving low-income workers better access to public transportation.

“They didn’t have enough roads to relieve the traffic,” said Victor Jasso, who directs the Mexicable. “There was no space for expanding the roadway. Making [bus-only lanes] was impossible. And building a subway? Also not a chance.”

That’s a marked departure from how gondolas have historically been used: climbing steep hills, as in Portland, Ore.; crossing bodies of water, like the Roosevelt Island Tram in New York City; or giving tourists a new perspective on a city, as they do in London.
More information at the Boston Globe, because Boston is considering a similar system.

09 March 2018

The mystery of the "cotton" in the window frame - updated

The arrival of September at our latitude marks the time when windows closed all summer can be opened to admit cool night air.  As I opened the window on our guest room, I was startled to see a wad of cotton-like material tumble from the upper window frame (above, placed on the concrete driveway for imaging).

My initial anxiety was that some sort of insulation was coming loose, but the original location of the material (photo below) ruled out that possibility.

My attention was now drawn to the contents of the mass, which to my initial dismay revealed an insect pupa and a number of living larvae:

After searching several combinations of key words in Google Images, I found one entry that matched my experience.  The brief explanation there was that the mass was the creation of a solitary bee.

Now I did feel bad, because my wife and I are great fans of solitary bees.  But armed with that clue, it didn't take long to track down the answer:
Anthidium manicatum, commonly called the European wool carder bee, is a species of bee in the family Megachilidae, the leaf-cutter bees or mason bees.

They get the name 'carder' from their behaviour of scraping hair from leaves such as lamb's ears (Stachys byzantina)... They scrape the hairs from the leaves and carry them back to their nests bundled beneath their bodies. There it is used as a lining for their nest cavities.  Females tend to build their nests at high locations.
I don't know whether the larvae in the photo are bee-related or parasites.

Reposted from 2016 because this week I was wandering through the "gardening" section of our local Target store and found this:

The shelf tag erroneously said "butterfly house."  The label on the product was slightly less inaccurate with "insect house."  It is in fact a structure designed for solitary bees.  There are online instructions for making these as a DIY project, but this one was nicely made and inexpensive.  I'll hang it from a shepherd's crook near ground level in our garden and hope to see some of the tubes getting filled as the summer progresses.

Here is a photo of an equivalent bee-condo viewed in cross-section:

This one was made by drilling holes in a wood block (presumably with a removable flap so the curious home scientist could inspect the process and the season progressed).

If I remember, I'll try to post followup photos in the summer and autumn.

Ruby and Rosie

Ruby Loftus Screwing a Breech Ring is a 1943 painting by the British painter Laura Knight depicting a young woman, Ruby Loftus (1921–2004), working at an industrial lathe as part of the British war effort in World War II. The painting was commissioned by the War Artists' Advisory Committee (WAAC), and is now part of the Imperial War Museum's art collection. The painting brought instant fame to Loftus, and has been likened to the American figure of "Rosie the Riveter".

More about Rosie the Riveter.
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