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Sunday, August 20, 2017

LIDAR, Connecticut Forests, and Iowa Marching Bear Effigy Mounds

       Dr. Katharine Johnson from the University of Connecticut (UConn) focuses on uncovering  
hidden remnants of the past using LIDAR imaging. The name LIDAR, sometimes considered an acronym of Light Detection And Ranging (sometimes Light Imaging, Detection, And Ranging), was originally a portmanteau of light and radar. Johnson and her colleagues have been piercing dense forest cover to uncover historic sites in New England (as seen here in Plainfield, Connecticut).


     Many of the tree-covered landscapes of modern New England were not always so green. In the 17th century, the region was the site of widespread deforestation, as European colonists built farms and homesteads. Between 60 to 80 percent of the land was cleared for fields, pastures, and orchards; these were surrounded with stone walls, houses, outbuildings, and roads.

      The natural-color photograph above was shot during an aerial survey in 2012. The monochromatic light detection and ranging (LIDAR) image, captured in 2010, shows the same area with greater contrast and reveals features on the ground. 

      LIDAR instruments send out rapid pulses of laser light that reflect off of solid surfaces (such as tree limbs or the ground). A receiver detects the photons that bounce back to the instrument, parsing out subtle variations in land elevation and allowing researchers to distinguish bumps and surfaces on the terrain.

      LIDAR has been used by archaeologists in other landscapes, perhaps most famously in Belize, where researchers have used it to uncover ancient Maya sites. The startling Marching Bear Effigy Mounds in northeastern Iowa were highlighted with LIDAR as well.


     “You can see patterns people made as they were dividing the landscape and farming,” said Johnson. LIDAR imaging helped them uncover traces of stone walls, dams, abandoned roads, building foundations, farm structures, and relict charcoal hearths—all of which have been slowly hidden over the past two centuries as the forest reclaimed the land.

 “The biggest surprise was being able to see the extent to which historic land use had impacted the landscape, which is not something that is readily visible in high-resolution aerial photos.”

Happy 24th birthday to Zoƫ today! Here she is celebrating with fellow Peace Corps volunteers in Ethiopia.

Have you used LIDAR?

Tuesday, August 8, 2017

Crinoids for Cri-nerds

     We discussed crinoids,
also known as sea "lilies," here at Partial Ellipsis of the Sun in April. This extraordinarily well-preserved Paleozoic crinoid fossil sample (below) inspired another look at this animal that looks like a plant.

      Compare the sample above to the "Smarties" stem pieces we found in northern Arkansas in April. The disarticulated crinoid stems or stalks are relatively common, but the delicate, lacy crown pieces are much rarer.

      Modern day crinoids and the fossil animals are quite similar, hence they are often referred to by the non-scientific term "living fossils."

       The parts of crinoid animals are labelled below, though the terms are quite plant-based:

I guess you could say I'm a bit of a cri-nerd ;-).

     How about you?

Monday, July 31, 2017

DNA of Ancient Canaanites: Levant, Lebanon, and Lines

      Researchers have deciphered the complete DNA of five Canaanite skeletons. By comparing these five Canaanite genomes with those of other ancient and modern populations, the scientists identified the Canaanites’ ancestors and discovered their descendants were modern Lebanese people.

     The results, reported July 27 in the American Journal of Human Genetics, give new insight into the origins and fate of a people whose story has largely been told through the secondhand accounts of its contemporaries.

     "The Canaanites emerged in the Levant, a region east of the Mediterranean Sea, 3,000 to 4,000 years ago. This cultural group, which established extensive trade networks and colonies across the Mediterranean region, left behind few written records, perhaps because they wrote on papyrus rather than clay. So most knowledge of the Canaanites comes from ancient Egyptian, Hebrew and Greek documents."

     "But, doubt surrounds some of those accounts. For one thing, Greek historians thought the Canaanites originated near the Persian Gulf, whereas archaeological records suggest they arose from farming communities that settled the Levant up to 10,000 years ago. For another, the Old Testament makes reference to the destruction of Canaanite communities, but some of their cities, such as Sidon in Lebanon, appear to have been continually inhabited through the present day."

     "Researchers reconstructed the genomes of the 3,700-year-old remains of five Canaanites unearthed in Sidon. Comparisons of these genomes with those of other ancient Eurasian peoples indicate that Canaanite ancestry was split roughly 50-50 between the early farmers who settled the Levant and immigrants of Iranian descent who arrived later, between 6,600 and 3,550 years ago."

     “You’d need a lot of migration for roughly half of the population to be replaced by the incoming Iranian-related populations,” says Iosif Lazaridis, a geneticist at Harvard Medical School who was not involved in the study. “This must have been some important event in the history of the Near East.” One possibility is the spread of the Akkadian Empire, which controlled a region spanning from the Levant to Iran between 4,400 and 4,200 years ago. That connection may have presented the opportunity for interbreeding between these far-flung populations."

     "The researchers also determined that modern Lebanese people can attribute about 93 percent of their ancestry to the Canaanites. The other 7 percent comes from Eurasians who probably arrived in the Levant 3,700 to 2,200 years ago. Study coauthor Chris Tyler-Smith, was surprised by how much Canaanite heritage dominated modern Lebanese DNA. He says he expected to see a more mixed gene pool because so many populations have crossed through the Levant in the last few thousand years."

     "This study alone may not paint the complete picture of the Canaanite lineage, says Aaron Burke, an archaeologist at UCLA, because the researchers examined the genomes of only five Canaanites."

      "However, the study’s Canaanite genetic data do provide “a snapshot of history in the area,” Lazaridis said. Identifying which populations crop up in the Canaanite lineage — and when — can help trace the historical movements of people throughout the Near East. With DNA analyses of enough ancient people, Lazaridis says, “I think it will be possible to reconstruct the whole timeline of what happened in Lebanon and other parts of the world.” 

No lamentations; looking forward to more data!

Monday, July 17, 2017

Not Puzzling at All: Crossword Puzzlers Have Better Brain Function

      The more regularly people report doing word puzzles such as crosswords, the better their brain function in later life, a large-scale and robust online trial, published today, has found.

      Researchers at the University of Exeter Medical School and Kings College, London, analyzed data from more than 17,000 healthy people aged 50 and over, submitted in an online trial. In research presented at the Alzheimer's Association International Conference (AAIC) 2017, the team asked participants how frequently they played word puzzles such as crosswords.

     "The study, one of the largest of its kind, used tests from the CogTrackTM and PROTECT online cognitive test systems to assess core aspects of brain function. They found that the more regularly participants engaged with word puzzles, the better they performed on tasks assessing attention, reasoning and memory."

       "From their results, researchers calculate that people who engage in word puzzles have brain function equivalent to ten years younger than their age, on tests of grammatical reasoning speed and short term memory accuracy."

      Keith Wesnes, Professor of Cognitive Neuroscience at the University of Exeter Medical School, said: "We found direct relationships between the frequency of word puzzle use and the speed and accuracy of performance on nine cognitive tasks assessing a range of aspects of function including attention, reasoning and memory. Performance was consistently better in those who reported engaging in puzzles, and generally improved incrementally with the frequency of puzzle use. For example, on test measures of grammatical reasoning speed and short-term memory accuracy, performing word puzzles was associated with an age-related reduction of around 10 years. We now need to follow up this very exciting association in a clinical trial, to establish whether engaging in puzzles results in improvement in brain function."

      "The study used participants in the PROTECT online platform, run by the University of Exeter and Kings College London. Currently, more than 22,000 healthy people aged between 50 and 96 are registered in the study, which is planning further expansion. The online platform enables researchers to conduct and manage large-scale studies without the need for laboratory visits. PROTECT is a 10 year study with participants being followed up annually to enable a better understanding of cognitive trajectories in this age range. 

     Clive Ballard, Professor of Age-Related Diseases at the University of Exeter Medical School, said: "We know that many of the factors involved in dementia are preventable. It is essential that we find out what lifestyle factors really make a difference to helping people maintain healthy brains to stop the soaring rise of the disease. We can't yet say that crosswords give you a sharper brain -- the next step is to assess whether encouraging people to start playing word games regularly could actually improve their brain function."

     "This new research does reveal a link between word puzzles, like crosswords, and memory and thinking skills, but we can't say definitively that regular 'puzzling' improves these skills. To be able to say for sure, the crucial next step is to test if there are benefits in people who take up word puzzles."

       Looks like Will Shortz took up a good profession. No puzzle there.

What do you think, cruciverbalists all? 

{I see a few holes in the study, but every good crossword puzzle needs a few holes/black squares, eh?}

Thursday, July 6, 2017

A Concrete Idea: Roman Sea Walls--Ash Me No Questions

      Ancient Roman concrete is still standing strong after thousands of years and, not only does it resist damage, but the salt water actually makes it stronger. X-ray examinations may have found the key to the concrete's amazing longevity, which could help improve modern concrete recipes. Dissolving phillipsite in pumice, as seen in this Scanning Electron Microscope (SEM) image, is believed to be part of the secret:

      Note that modern sea walls last only a few years in salt water where these Roman sea walls have lasted thousands of years.

      Although the complete recipe has been lost over the years, studies of samples have shown that volcanic ash, lime, and seawater are the main ingredients. "But, according to an article published in American Mineralogist the real magic seems to happen when those ingredients interact with the environment – specifically the saltwater incessantly pounding on the surface."

     Al-tobermorite is part of the cementing matrix, key to its strength. Modern "Portland cement" relies more heavily on heating the elements, exacting an environmental toll.

Huzzah for the ancient Romans. . .and for seawater! Has this idea been cemented in your brain?

Pink Martini and Rufus Wainwright at Red Rocks, July 6, 2017:

Wednesday, June 28, 2017

6/28: So Much More Than Tau Day, It's a Perfect Day

      June 28th as Tau Day (pi x 2) is only part of the story of today's date. The digits in 6/28 (or 28/6, if you will, mate) are made up of two perfect numbers. A perfect number is a number that is the sum of its factors besides itself, and 6 (1+2+3) and 28 (1+2+4+7+14) are the first two perfect numbers. 

      Today is also my twin brothers' birthday. This morning, I also found out that my mom picked today, the perfect day, for inducing their birth! (It is also her best friend's birthday.)

     The next two perfect numbers are 496 and 8,128.


      The relationship between Mersenne prime numbers and perfect numbers is seen below:

      A Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number that can be written in the form Mersenne number = 2n − 1 for some integer n. They are named after Marin Mersenne, a Frenchman who studied them in the early 17th century. The first four Mersenne primes are 3, 7, 31, and 127 (although some of Mersenne's primes were proven later to be incorrect).

      As of May 2017, the largest known prime number is 274,207,281 − 1, a number with 22,338,618 digits. It was found in 2016 by the Great Internet Mersenne Prime Search (GIMPS-ha!). 

        Primes, GIMPS, perfection, oh my!

       Happy Birthday and have a luminescent trip around the sun, bros. Hope you had a parfait day!

Hope you've all had a perfect day, or at least a few perfect moments,

     5000 new neighbors moved into our backyard yesterday!


Monday, June 19, 2017

Celebrate Cephalopod Week: Squid, Octopuses, Cuttlefish, and Nautiluses

       It's the second annual Cephalopod Week.  How can you not love a creature whose name means head-foot? Cue the "open mouth/insert foot jokes."

        How will you celebrate?!

      Cuddle a cuddlefish with its 'W'-shaped eyes?

      Ogle an octopus, like this one from the Maldives? 

      Swim with a squid, like this technicolored fellow?

       Net with a nautilus?

      Come on out of your shell and join the Cephalopod Party. Cephalo off to Buffalo?

Do you have a favorite cephalopod. . .and why? {I like them all; off to celebrate!}