Saturday, June 26, 2021

Experts get 1st clues on what may have caused condo collapse

By CURT ANDERSON and BOBBY CAINA CALVAN

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This photo provided by Miami-Dade Fire Rescue, search and rescue personnel search for survivors through the rubble at the Champlain Towers South Condo in Surfside, Fla., section of Miami, Friday, June 25, 2021. The apartment building partially collapsed on Thursday. (Miami-Dade Fire Rescue via AP)

ST. PETERSBURG, Fla. (AP) — Some of the concrete columns were cracked. The parking garage was frequently flooded with corrosive saltwater. And the roof was undergoing repairs, with crews pounding on the tower from above for weeks.

Officials don’t yet know whether any — or all — of those factors caused a Florida beachside condominium tower to suddenly collapse Thursday morning.

But experts are closely examining a 2018 repor t that identified numerous issues with the Champlain Towers South building in Surfside, including “major structural damage” to a concrete structural slab below its pool deck that needed to be extensively repaired.

“Failure to replace waterproofing in the near future will cause the extent of the concrete deterioration to expand exponentially,” said the report from the Morabito Consultants engineering firm. The situation is a “major error” dating to the building’s original construction, according to the report, which was released with other documents late Friday by Surfside officials.

The report also uncovered “abundant cracking” and other faults in concrete columns, beams and walls in the parking garage. Some of the damage was minor, while other columns had exposed and deteriorating rebar.



It wasn’t immediately clear from the documents whether this issue or others identified in the report were ever dealt with or had any role in the building collapse. Frank Morabito, the firm’s president, did not immediately respond Saturday to an email seeking comment.

The building was in the midst of its 40-year recertification process, which requires detailed structural and electrical inspections. In an interview Friday, Surfside Mayor Charles Burkett said he wasn’t sure if the inspection had been completed, but he said it may contain vital clues.

“It should have been a very straightforward thing,” Burkett said. “Buildings in America do not just fall down like this. There is a reason. We need to find out what that reason is.”

The 12-story tower’s collapse has left at least four people dead, 159 missing as of Friday and numerous questions about how this could have happened — and whether other similar buildings are in danger.

Details of the Champlain Towers recertification inspection will be made public once they are completed, Surfside Town Clerk Sandra McCready said in an email.




Miami-Dade Mayor Daniella Levine Cava said at a news conference Friday that she has seen no evidence of a sinkhole — much more common in other parts of Florida — or of something criminal, such as a bomb.

“I can tell you that at this time, they haven’t found any evidence of foul play,” she said.

Beyond that, much focus is on ocean water, which is rising in South Florida and elsewhere because of climate change. Last year, Republican Gov. Ron DeSantis signed into law a measure that would require developers to complete sea-level rise studies before beginning publicly funded projects.

Like everyone else, the governor wants answers about the cause of the collapse as soon as possible.

“We need a definitive answer for how this might have happened,” DeSantis said at a news conference. “It really is a unique type of tragedy to have, in the middle of the night, half a building just collapse like that.”

Meanwhile, the land on which Champlain Towers sits has been gradually sinking, according to a study published last year by an environmental professor at Florida International University.

But the professor, Shimon Wdowinski, cautioned against blaming the collapse on the caving ground. The study used satellite data collected between 1993 to 1999 to study the sinking of land in Norfolk, Virginia, and Miami Beach.

In a video interview released by the university, Wdowinski said his study found numerous examples of sinking earth, some leading to cracks in buildings — which he called “pretty common” in Florida.

“In most cases, these buildings just move,” he said, “there’s no catastrophic collapse like in the case in Surfside, which was very unfortunate.”




Another theory is that the saltwater ubiquitous in the area, which is subject to flooding during so-called King Tide events, intrudes into concrete supports, corrodes the steel-reinforcing rebar inside and weakens the concrete.

Abi Aghayere, an engineering researcher at Drexel University, said determining if there was such deterioration could be one key to the collapse.

“Did a column fail by itself? This column has been carrying this load for 40 years, why would it fail now?” said Aghayere, adding that it is rare for rebar to be corroded without anyone noticing. “You will have concrete popping out, falling out.”

Others have cited frequent flooding in the building’s lower parking garage, including the possibility of water seeping up underneath through the porous limestone rock on which the barrier island sits that includes Surfside and Miami Beach.

Surfside officials say roof work was ongoing at the now-collapsed tower but have downplayed the possibility that work was a cause. Barry Cohen, a lawyer who escaped the crippled Champlain Towers building with his wife, said the roof work could be part of a “perfect storm” of causes that combined to bring down the structure.

“They were doing a new roof. And I think, all day long, the building was pounding and pounding and pounding. They’ve been doing it for over a month,” Cohen said.

Another issue cited by some people is construction at a nearby building that might cause vibrations that weakened Champlain Towers. Cohen said he raised concerns previously that the work was possibly causing cracked pavers on the pool deck.

The collapse is already drawing lawsuits, including one filed hours after the collapse by attorney Brad Sohn against the condo’s homeowners association seeking damages for negligence and other reasons for all of the tower’s residents.

The association, the lawsuit contends, “could have prevented the collapse of Champlain Towers South through the exercise of ordinary care, safety measures and oversight.”

An attorney for the association, Ken Direktor, did not respond Friday to an email requesting comment.

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Associated Press writers Freida Frisaro in Fort Lauderdale, Florida; and Bernard Condon in New York contributed to this report.



SEE

LET'S NOT FORGET THIS HAPPENED ONLY 
THREE DAYS EARLIER

USS Gerald Ford shock trials register as 3.9 magnitude ...

https://www.cbsnews.com/news/uss-gerald-ford-shock-trials-earthquake-florida

2021-06-21 · The blast registered as a 3.9 magnitude earthquake. June 21, 2021 / 2:26 PM / CBS/AFP. The U.S. Navy has started a series of tests on its newest and most advanced aircraft carrier





‘Deep fire’ slowing rescue effort at collapsed Florida condo

By RUSS BYNUM, CURT ANDERSON and BERNARD CONDON

SURFSIDE, Fla. (AP) — A “very deep fire” hampered rescue efforts Saturday at the collapsed oceanfront condominium tower near Miami where authorities are racing to recover any survivors beneath a mountain of rubble, officials said.

Rescuers were using infrared technology, water and foam to battle the blaze, whose source was unclear. Smoke has been the biggest barrier, Miami-Dade Mayor Daniella Levine Cava said during a news conference.

“We’re facing very incredible difficulties with this fire. It’s a very deep fire. It’s extremely difficult to locate the source of the fire,” she said.

One hundred fifty-nine people remain unaccounted for since Thursday’s collapse, which killed at least four.

Authorities also announced Saturday they are beginning an audit of buildings nearing their 40-year review — like the fallen Champlain Towers South — to make sure they’re safe.

Federal Emergency Management Agency officials have joined local and state authorities at the site, Florida Gov. Ron DeSantis said.

The news came after word of a 2018 engineering report that showed the building had “major structural damage” to a concrete slab below its pool deck that needed extensive repairs, part of a series of documents released by the city of Surfside.

While the report from the firm of Morabito Consultants did not warn of imminent danger from the damage — and it is unclear if any of the damage observed was responsible for the collapse — it did note the need for extensive and costly repairs to fix systemic issues with the building.

It said the waterproofing under the pool deck had failed and had been improperly laid flat instead of sloped, preventing water from draining off.

“The failed waterproofing is causing major structural damage to the concrete structural slab below these areas. Failure to replaced the waterproofing in the near future will cause the extent of the concrete deterioration to expand exponentially,” the report said.

The firm recommended that the damaged slabs be replaced in what would be a major repair.

The report also uncovered “abundant cracking and spalling” of concrete columns, beams and walls in the parking garage. Some of the damage was minor, while other columns had exposed and deteriorating rebar. It also noted that many of the building’s previous attempts to fix the columns and other damage with epoxy were marred by poor workmanship and were failing.

Beneath the pool deck “where the slab had been epoxy-injected, new cracks were radiating from the originally repaired cracks,” the report said.

Gregg Schlesinger, a former construction project engineer who is now a lawyer handling construction defect cases, said another area of concern in the report is cracks that were discovered in the tower’s stucco facade. Schlesinger said that could indicate structural problems inside the exterior that could have been critical in the collapse.

“The building speaks to us. It is telling us we have a serious problem,” Schlesinger said in a phone interview Saturday.

He added that there are frequently “telltale signs” on oceanfront buildings indicating problems structurally largely from saltwater and salty air intrusion.

“This is a wakeup call for folks on the beach. Investigate and repair. This should be done every five years,” Schlesinger added. “The scary portion is the other buildings. You think this is unique? No.”

Abi Aghayere, a Drexel University engineering researcher, said the extent of the damage shown in the engineering report was notable. In addition to possible problems under the pool, he said several areas above the entrance drive showing signs of deterioration were worrisome and should have been repaired immediately because access issues prevented a closer inspection.

“Were the supporting members deteriorated to the extent that a critical structural element or their connections failed leading to progressive collapse?” he wrote in an email to the AP after reviewing the report. “Were there other areas in the structure that were badly deteriorated and unnoticed?”

On Saturday, a crane could be seen removing pieces of rubble from a more than 30-foot pile of debris at the collapse site. Scores of rescuers used big machines, small buckets, drones, microphones and their own hands to pick through the mountain of debris that had been the 12-story Champlain Towers South.

Levine Cava told WPLG there was no change in the number of people still unaccounted for: “We are at status quo,” she said. “I’m hopeful this will be a day that we have will have a breakthrough.”

Rachel Spiegel was anxious for any update on her missing mother, 66-year-old Judy Spiegel, who lived on the sixth floor.

“I’m just praying for a miracle,” Spiegel said. “We’re heartbroken that she was even in the building.”

Jeanne Ugarte was coming to grips with what she feared was a tragic end for longtime friends Juan and Ana Mora and their son Juan Jr., who was visiting his parents in their condo at the tower.

“I know they’re not going to find them (alive),” Ugarte said. “It’s been too long.”

While officials said no cause for the collapse early Thursday has been determined, Gov. Ron DeSantis said a “definitive answer” was needed in a timely manner. Video showed the center of the building appearing to tumble down first, followed by a section nearer to the beach.

The 2018 report was part of preliminary work by the engineering company conducting the building’s required inspections for a recertification due this year of the building’s structural integrity at 40 years. The condominium tower was built in 1981.

___

Condon reported from New York. Associated Press Terry Spencer in Surfside contributed to this report.

TOYOTA ARMY
Iraq paramilitaries show off weaponry in big, anniversary parade

BAGHDAD (Reuters) - Thousands of Iraqi paramilitary fighters, including powerful Iran-backed factions, marched at a military base in eastern Iraq on Saturday showcasing tanks and rocket launchers in their biggest formal parade to date
.
© Reuters/MEDIA OFFICE PMF Iraq's PMF holds military parade in Diyala province

The event, attended by Iraqi Prime Minister Mustafa al-Kadhimi, marked seven years since the Popular Mobilisation Forces (PMF) were formed to fight the Sunni Muslim extremist Islamic State group.

"I esteem your sacrifices, and the sacrifices of the Iraqi armed forces" in fighting Islamic State, Kadhimi said, warning against any "sedition" within the PMF, but without elaborating.

The PMF's establishment created a state-sanctioned umbrella organisation of mostly Shi'ite militias backed by Iran.

The Iran-aligned factions, which are the most powerful in the PMF, have since Islamic State's defeat in 2017 expanded their military, political and economic power and attacked bases housing the 2,500 remaining U.S. forces in Iraq.
© Reuters/MEDIA OFFICE PMF Iraq's PMF holds military parade in Diyala province

They have allies in parliament and government and a grip over some state bodies, including security institutions.

Video: Afghan leaders on troop drawdown, Taliban threat (Associated Press)

Those factions are also accused of killing protesters who took to the streets in late 2019 demanding the removal of Iraq's ruling elite. The groups deny involvement in activist killings.

Kadhimi, a U.S.-friendly interim premier, has tried to crack down on the most powerful Iran-backed factions but without success because of their military strength and political influence.

The membership of Iran-aligned groups in the PMF has made it difficult for Kadhimi and state security forces to check the power of the militias, since they are effectively part of the state itself.

On Saturday Kadhimi watched, flanked by militia commanders while hundreds of armoured vehicles drove past a banner of the late PMF military chief Abu Mahdi al-Muhandis, an Iran-backed commander who was killed in a U.S. drone strike last year.

© Reuters/MEDIA OFFICE PMF Iraq's PMF holds military parade in Diyala province

The parade, a demonstration of military might, took place at a base once occupied by U.S. troops near the border with Iran.

The PMF was formed in 2014 after Iraq's top Shi'ite cleric Grand Ayatollah Ali al-Sistani urged all able-bodied Iraqis to take up arms against Islamic State, which had taken over a third of Iraq.

(Reporting by John Davison; Editing by Christina Fincher)

GOOD NEWS

Study confirms the low likelihood that SARS-CoV-2 on hospital surfaces is infectious

UNIVERSITY OF CALIFORNIA - DAVIS HEALTH

Research News

A new study by UC Davis researchers confirms the low likelihood that SARS-CoV-2 contamination on hospital surfaces is infectious. The study, published June 24 in PLOS ONE, is the original report on recovering near-complete SARS-CoV-2 genome sequences directly from surface swabs.

"Our team was the first to demonstrate that SARS-CoV-2 virus sequences could be identified from environmental swabs collected from hospital surfaces," said Angela Haczku, a respiratory immunologist and senior author on the study.

Changing cleaning and ICU protocols linked to lower SARS-CoV-2 contamination

In April 2020, a COVID-19 outbreak among hospital staff led an interdisciplinary team of UC Davis researchers to investigate if there was virus contamination of frequently used surfaces in patient serving ICU and staff meeting areas at the UC Davis Medical Center. At that time the role of fomites (surfaces) in spreading the disease was highly debated. They collected multiple samples during the first (April 2020) and the second (August 2020) waves of COVID-19 from surfaces and HVAC filters in the hospital.

The researchers analyzed the surface swabs for SARS-CoV-2 RNA and infectivity and assessed the suitability of the RNA for sequencing.

Despite a significant increase in the number of hospital patients with COVID-19 during the second surge, the team found that only 2% of swabs tested positive in August, compared to 11% of samples collected in April.

"The reduction in the virus contamination was likely due to improved ICU patient management and cleaning protocols," Haczku said. Haczku is a professor of medicine, director at the UC Davis Lung Center and associate dean for translational research at the UC Davis School of Medicine.

Genome sequence of coronavirus found on surfaces

The study demonstrated that by genome sequencing, SARS-CoV-2 could be detected even from samples that otherwise tested negative (undetectable) by commonly used PCR tests. The results also confirmed that the SARS-CoV-2 RNA picked up from a surface, although containing near- intact genomic sequence, was not infectious. This finding supports the hypothesis that contaminated surfaces may not be a major way for spreading COVID-19 disease.

"For the first time, to our knowledge, we were able to determine the viral genome sequence from surface swab samples obtained in a hospital environment," said David Coil, project scientist at the UC Davis Genome Center and the first author on the study. "We found SARS-CoV-2 in samples that were tested negative by RT-PCR, suggesting that the sequencing technology is superior for virus detection in environmental samples."

According to Coil, the genome sequencing performed on the hospital surface swab samples is very important. By getting accurate viral genomic sequences, the researchers could track the source and figure out how an infection moves.

"Our data indicated that the sequences determined for the viral RNA from surfaces were identical to the ones derived from the patients hospitalized in the ICU at the time of sample collection. The ability to identify viral genome sequences from environmental samples may have high public health significance in outbreak surveillance and monitoring the spread of new viral variants," Haczku said.

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This study was funded by a UC Davis CRAFT Award and The Chester Robbins Endowment.

UC Davis co-authors are Timothy Albertson, Christian Sandrock, Daniel G Tompkins, Maya Juarez, Brandt Robinson, Shefali Banerjee, Greg Brennan, Satya Dandekar, Stefan Rothenburg , Ana Stoian, A.J. Campbell, Ivy Jose, Samuel L. Díaz-Muñoz, Stuart H. Cohen, Jonathan A. Eisen, Tracey Goldstein and Alexandre Tremeau-Bravard.

 

Decoding humans' survival from coronaviruses

UNIVERSITY OF ADELAIDE

Research News

IMAGE

IMAGE: CORONAVIRUS GRAPHIC view more 

CREDIT: PIXABAY IMAGE BY GERD ALTMANN

An international team of researchers co-led by the University of Adelaide and the University of Arizona has analysed the genomes of more than 2,500 modern humans from 26 worldwide populations, to better understand how humans have adapted to historical coronavirus outbreaks.

In a paper published in Current Biology, the researchers used cutting-edge computational methods to uncover genetic traces of adaptation to coronaviruses, the family of viruses responsible for three major outbreaks in the last 20 years, including the ongoing pandemic.

"Modern human genomes contain evolutionary information tracing back hundreds of thousands of years, however it's only in the past few decades geneticists have learned how to decode the extensive information captured within our genomes," said lead author Dr Yassine Souilmi, with the University of Adelaide's School of Biological Sciences.

"This includes physiological and immunological 'adaptions' that have enabled humans to survive new threats, including viruses.

"Viruses are very simple creatures with the sole objective to make more copies of themselves. Their simple biological structure renders them incapable of reproducing by themselves so they must invade the cells of other organisms and hijack their molecular machinery to exist."

Viral invasions involve attaching and interacting with specific proteins produced by the host cell known as viral interacting proteins (VIPs).

In the study researchers found signs of adaptation in 42 different human genes encoding VIPs.

"We found VIP signals in five populations from East Asia and suggest the ancestors of modern East Asians were first exposed to coronaviruses over 20,000 years ago," said Dr Souilmi.

"We found the 42 VIPs are primarily active in the lungs - the tissue most affected by coronaviruses - and confirmed that they interact directly with the virus underlying the current pandemic."

Other independent studies have shown that mutations in VIP genes may mediate coronavirus susceptibility and also the severity of COVID-19 symptoms. And several VIPs are either currently being used in drugs for COVID-19 treatments or are part of clinical trials for further drug development.

"Our past interactions with viruses have left telltale genetic signals that we can leverage to identify genes influencing infection and disease in modern populations, and can inform drug repurposing efforts and the development of new treatments," said co-author Dr Ray Tobler, from the University of Adelaide's School of Biological Sciences.

"By uncovering the genes previously impacted by historical viral outbreaks, our study points to the promise of evolutionary genetic analyses as a new tool in fighting the outbreaks of the future." said Dr Souilmi.

The researchers also note that their results in no way supersede pre-existing public health policies and protections, such as mask wearing, social distancing, and vaccinations.

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The team involved in this study also included researchers from Australian National University and Queensland University of Technology.


Changes in farming practices could reduce greenhouse gas emissions by 70% by 2036

DOE/ARGONNE NATIONAL LABORATORY

Research News

Team used Argonne's GREET model to simulate changes, predict outcomes.

Scientists from the U.S. Department of Energy's Argonne National Laboratory participated in a study that shows innovation in technologies and agricultural practices could reduce greenhouse gas (GHG) emissions from grain production by up to 70% within the next 15 years.

Published in Proceedings of the National Academy of Sciences of the United States, the study identifies a combination of readily adoptable technological innovations that can significantly reduce emissions and fit within current production systems and established grain markets.

The study, "Novel technologies for emission reduction complement conservation agriculture to achieve negative emissions from row crop production," maintains that reductions in GHG emissions could be attained through digital agriculture, crop and microbial genetics and electrification. The new technologies, when implemented, promise to drive the decarbonization of agriculture while supporting farm resilience and maintaining profitability and productivity. 

Technologies were grouped across three phases: optimize, replace and redesign. The team used Argonne's GREET® model to simulate adoption of the new technologies for holistic greenhouse gas emission reductions of grain production. Argonne developed GREET (the Greenhouse gases, Regulated Emissions, and Energy use in Technologies Model), a one-of-a-kind lifecycle analytical tool now used worldwide by government, industry and the science community.

The study offers insights for the development of possible new approaches for agriculture decarbonization and suggests entry points for public and private investment based on a timeline of expected returns on investments in new technologies.

"Our study emphasizes the importance of a two-pronged approach -- reducing farming emissions and maximizing soil carbon storage -- to addressing the climate crisis through agriculture. Practices that enhance soil carbon storage continue to gain momentum. Complementing this approach by developing and broadly applying emission reduction technologies, including seed genetics, is critical to achieving net negative production," said Dan Northrup, lead author of the study and director of special projects at Benson Hill, a St Louis based company leveraging the natural genetic diversity of plants to develop more healthy and sustainable food choices.

Argonne Energy Systems Division's senior scientist Michael Wang, who leads the Systems Assessment Center and is one of the study's principal investigators, added, "Our holistic assessment of agriculture decarbonization highlights technical areas and focus points so that U.S. agriculture will be a solution to the climate challenge."

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Other research team members included Philip Benfey of Duke University, HHMI and Hi Fidelity Genetics, a company commercializing an in-field sensor-based root monitoring platform for crop plants; Bruno Basso of Michigan State University and CiBO Technologies, innovators of a breakthrough technology platform that accelerates regenerative agriculture; and Cristine Morgan of the Soil Health Institute, a nonprofit that safeguards and enhances the vitality and productivity of soil through research and advancement.

This research is funded by the SMARTFARM Program of DOE's ARPA-E and DOE's Bioenergy Technologies Office in the Office of Energy Efficiency and Renewable Energy.

The Office of Energy Efficiency and Renewable Energy supports early-stage research and development of energy efficiency and renewable energy technologies to strengthen U.S. economic growth, energy security, and environmental quality.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

Did the ancient Maya have parks?

First-of-its-kind DNA analysis finds trees and wild vegetation grew around reservoirs in Tikal

UNIVERSITY OF CINCINNATI

Research News

IMAGE

IMAGE: A PYRAMID AT TIKAL RISES FROM THE RAINFOREST IN GUATEMALA. view more 

CREDIT: DAVID LENTZ

The ancient Maya city of Tikal was a bustling metropolis and home to tens of thousands of people.

The city comprised roads, paved plazas, towering pyramids, temples and palaces and thousands of homes for its residents, all supported by agriculture.

Now researchers at the University of Cincinnati say Tikal's reservoirs -- critical sources of city drinking water -- were lined with trees and wild vegetation that would have provided scenic natural beauty in the heart of the busy city.

UC researchers developed a novel system to analyze ancient plant DNA in the sediment of Tikal's temple and palace reservoirs to identify more than 30 species of trees, grasses, vines and flowering plants that lived along its banks more than 1,000 years ago. Their findings paint a picture of a lush, wild oasis.

"Almost all of the city center was paved. That would get pretty hot during the dry season," said paleoethnobotanist David Lentz, a professor of biology in UC's College of Arts and Sciences and lead author of the study.

"So it would make sense that they would have places that were nice and cool right along the reservoir," he said. "It must have been beautiful to look at with the water and trees and a welcome place for the kings and their families to go."

The study was published in the Nature journal Scientific Reports.

Lentz and his research team offered four hypotheses about what, if any, plants might have grown along the all-important reservoirs: Did the Maya grow crops such as maize or squash there? Or did they plant fruit trees like those found at a similar reservoir at Mexico's Purron Dam?

Maybe they lined the reservoirs with cattails in keeping with their nickname people of the reeds? Lentz noted that water lilies often adorn ancient Maya paintings.

"Throughout Maya iconography, water lilies represent continuity between the water world and the above world," Lentz said. "It was part of their mythology."

But researchers found little evidence to support any of these hypotheses. Instead, they found evidence bolstering a fourth idea: that the Maya allowed the embankments to remain undisturbed forest. This would have helped to prevent erosion and provided medicinal or edible plants and fruits.

Researchers found evidence of a variety of plants living along the aquifers, including trees like cabbage bark and ramón that tower 100 feet high. Lentz said ramón is a dominant rainforest species in Guatemala.

"Why you would find ramón around the reservoir is a curiosity. The answer is they left this forest intact," Lentz said. "Tikal has a harsh climate. It's pretty tough to survive when you don't get rain for five months of the year. This reservoir would have been the font of their lives. So they sometimes would protect these places by not cutting down the trees and preserving a sacred grove."

Among dozens of plants native to the region, they found evidence of wild onion, fig, wild cherry and two types of grasses. Lentz said grass seeds might have been introduced to the reservoir by visiting waterfowl. Grass would have proliferated at the edges of the reservoirs during dry seasons and droughts.

"Tikal had a series of devastating droughts. As the water levels dropped, they saw blue green algae blooms, which produces toxic substances," Lentz said. "The droughts were great for the grass but not so much for the forest plants that lived along the reservoir's banks."

Were these wild areas the equivalent of a park?

"I think they were. I don't know how public they would have been," Lentz said. "This was a sacred area of the city surrounded by temples and palaces. I don't know if the commoners would have been that welcome."

Tikal was a flourishing seat of power, religion and trade for Mesoamerica in what is now northern Guatemala, reaching its peak of influence more than 1,200 years ago. Today, the cultural and archaeological site is a scenic national park surrounded by primary rainforest.

But more than 1,000 years ago, the area would have looked dramatically different. Instead of rainforest, the city center would have been surrounded by homes and farm plots of corn, beans and squash needed to support 60,000 people or more. At its peak, Tikal was bigger in population than Wilkes-Barre, Pennsylvania; Atlantic City, New Jersey; or Pensacola, Florida.

Given the documented and widespread deforestation that occurred around Tikal during the city's rise and fall, the presence of an intact forest in the city would have stood out, said Nicholas Dunning, a UC geography professor and study co-author.

"It would not have been much of a park -- maybe 50 meters by 50 meters," Dunning said. "But it would have been in vivid contrast to the surrounding area of the city's central precinct, which was essentially entirely paved with plaster with many of the buildings colored red."

The reservoirs would have held significance beyond their value as an important source of water, he said.

"Given that the Maya were a forest culture whose cosmology included many forest elements (for example, certain sacred trees that held up the sky) having a sacred grove adjacent to the sacred spring and pool at the heart of the city was an extremely potent symbol -- kind of like parts of the cosmos in miniature," Dunning said. "On the other hand, ancient Maya cities as a whole were very green."

Tikal put today's urban gardens to shame.

"Away from the central precinct of Tikal, most of the land was either managed trees or crops," Dunning said. "Just about every household complex had significant gardens. A great deal of the food consumed by the residents of Maya cities was probably grown within the city itself or its immediate hinterland. Nothing much like a modern Western city."

Previously, researchers learned about the crops and wild plants that grew in ancient Tikal by studying ancient pollen or charcoal, Lentz said. For their study, UC turned to next-generation DNA sequencing that can identify plants and animals with even small strands of DNA.

"Typically, high-quality, high-concentration DNA is needed for next-gen work," UC botanist and study co-author Eric Tepe said. "The Tikal samples were both poor quality and very low concentration."

Microbiologists Alison Weiss, a professor in UC's College of Medicine, and Trinity Hamilton, now with the University of Minnesota, took up the task of analyzing ancient microbial DNA from the reservoir's sediment samples.

Weiss studies pathogenic E. coli and human microbiomes in her lab. Her latest work examined how chemotherapy in cancer patients impairs the protective lining of their digestive systems. But she likes all science, she said, and was eager to accept a new challenge.

"The DNA is ancient so it tends to be degraded with short little sequences," Weiss said.

With the help of the Florida company Rapid Genomics, UC's scientists developed a novel probe to select plant DNA in the sediment samples. And they were able to amplify small strands of DNA from chloroplasts, the plant structures where photosynthesis takes place. Then researchers could match the ancient Tikal samples with the DNA of known plant species in much the same way scientists amplify ribosomal DNA to identify species of bacteria.

"The analysis was quite challenging because we were the first to do this," Weiss said. "Bacterial ribosomal DNA has a database. There was no database for this. We had to take sequences one by one and search the general database to find the best match."

"This project was a bit of a shot in the dark," Tepe said. "We half-expected to get no results at all. The fact that we were able to get an idea of the vegetation surrounding the reservoirs at Tikal is, in my opinion, a spectacular success and a proof of concept that we hope to apply to other Mayan sites."

UC researchers can now study the ancient world in a promising new way.

"We're delighted we had success," Weiss said. "It took a long time to figure out how to do it and make sure it wasn't junk data in, junk data out. Now to be able to learn more about ancient people from these sediment studies is very exciting."


CAPTION

University of Cincinnati biology professor David Lentz stands in front of a pyramid at Tikal in Guatemala.



CAPTION

University of Cincinnati researchers Nicholas Dunning, Vernon Scarborough and David Lentz collect sediment samples for DNA analysis.

CREDIT

Liwy Grazioso Sierra

ANOTHER ARYAN RACE MYTH FALLS

Being Anglo-Saxon was a matter of language and culture, not genetics

New evidence to answer the question 'who exactly were the Anglo-Saxons?'

UNIVERSITY OF SYDNEY

Research News

IMAGE

IMAGE: THE FAMOUS ANGLO-SAXON SUTTON HOO HELMET FROM ABOUT 625 CE, PART OF THE BRITISH MUSEUM COLLECTION. PHOTO: ELISSA BLAKE/UNIVERSITY OF SYDNEY view more 

CREDIT: PHOTO: ELISSA BLAKE/UNIVERSITY OF SYDNEY

A new study from archaeologists at University of Sydney and Simon Fraser University in Vancouver, has provided important new evidence to answer the question "Who exactly were the Anglo-Saxons?"

New findings based on studying skeletal remains clearly indicates the Anglo-Saxons were a melting pot of people from both migrant and local cultural groups and not one homogenous group from Western Europe.

Professor Keith Dobney at the University of Sydney said the team's results indicate that "the Anglo-Saxon kingdoms of early Medieval Britain were strikingly similar to contemporary Britain - full of people of different ancestries sharing a common language and culture".

The Anglo-Saxon (or early medieval) period in England runs from the 5th-11th centuries AD. Early Anglo-Saxon dates from around 410-660 AD - with migration occurring throughout all but the final 100 years (ie 410-560AD).

Studying ancient skulls

Published in PLOS ONE, the collaborative study by Professor Dobney at University of Sydney and Dr Kimberly Plomp and Professor Mark Collard at Simon Fraser University in Vancouver, looked at the three-dimensional shape of the base of the skull.

"Previous studies by palaeoanthropologists have shown that the base of the human skull holds a shape signature that can be used to track relationships among human populations in a similar way to ancient DNA," Dr Plomp said. "Based on this, we collected 3D data from suitably dated skeletal collections from Britain and Denmark, and then analysed the data to estimate the ancestry of the Anglo-Saxon individuals in the sample."

The researchers found that between two-thirds and three-quarters of early Anglo-Saxon individuals were of continental European ancestry, while between a quarter and one-third were of local ancestry.

When they looked at skeletons dated to the Middle Anglo-Saxon period (several hundred years after the original migrants arrived), they found that 50 to 70 percent of the individuals were of local ancestry, while 30 to 50 percent were of continental European ancestry, which probably indicates a change in the rate of migration and/or local adoption of culture over time.

"These findings tell us that being Anglo-Saxon was more likely a matter of language and culture, not genetics," Professor Collard said.

The debate about Anglo-Saxons

Although Anglo-Saxon origins can clearly be traced to a migration of Germanic-speaking people from mainland Europe between the 5th and 7th centuries AD, the number of individuals who settled in Britain is still contested, as is the nature of their relationship with the pre-existing inhabitants of the British Isles, most of whom were Romano-Celts.

The ongoing and unresolved argument is whether hordes of European invaders largely replaced the existing Romano-British inhabitants, or did smaller numbers of migrants settle and interact with the locals, who then rapidly adopted the new language and culture of the Anglo-Saxons?

"The reason for the ongoing confusion is the apparent contradiction between early historical texts (written sometime after the events that imply that the newcomers were both numerous and replaced the Romano-British population) and some recent biomolecular markers directly recovered from Anglo-Saxon skeletons that appears to suggest numbers of immigrants were few," said Professor Dobney.

"Our new data sits at the interface of this debate and implies that early Anglo-Saxon society was a mix of both newcomers and immigrants and, instead of wholesale population replacement, a process of acculturation resulted in Anglo-Saxon language and culture being adopted wholesale by the local population."

"It could be this new cultural package was attractive, filling a vacuum left at the end of the Roman occupation of Britain. Whatever the reason, it lit the fuse for the English nation we have today - still comprised of people of different origins who share the same language," Professor Dobney said.

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Anglo-Saxon ancestry was 'mixed and mutable'

Skull analysis finds combination of indigenous and immigrant ancestors for early Anglo-Saxons

PLOS

Research News

IMAGE

IMAGE: PHOTOGRAMMETRY WITH SKULL view more 

CREDIT: KIMBERLY PLOMP

The ancestry of early Anglo-Saxons, a subject of some debate, included immigrants from continental Europe as well as people indigenous to Great Britain, according to a study published June 23, 2021 in the open-access journal PLOS ONE by Kimberly Plomp of Simon Fraser University, British Columbia and colleagues.

Between the 5th and 7th centuries CE, Germanic-speaking people from continental Europe settled across the island of Great Britain, leading to the formation of the Anglo-Saxon ethnic group, and eventually to the development of the English language and the Kingdom of England. Historical texts describe this event as an invasion, where continental immigrants replaced indigenous people, but some archaeological evidence contradicts this story, indicating that many early Anglo-Saxons in Great Britain were of local origin.

In this study, the authors sought to determine the ancestry of Anglo-Saxons by comparing their skull anatomy to that of indigenous and continental individuals. They used 3D shape analysis to compare 236 individuals from Early and Middle Anglo-Saxon cemeteries (410-899 CE), pre-Medieval sites in England (800 BCE-410 CE), and Iron Age sites in Denmark (800 BCE-399CE). The results indicate that, among Early Anglo-Saxon skeletons, 25-33% were of local ancestry, while among Middle Anglo-Saxon skeletons, 50-70% were local.

Thus, this study finds that Anglo-Saxons comprised individuals of both local and continental ancestry, and that the ratio between the two changed over time, possibly due to variations in immigration patterns. These results conflict with some previous data from historical texts, as well as isotopic and genetic analyses. The authors propose that future studies, sampling a wider selection of skulls and examining more regions of the skull, might provide more information to resolve these questions of Anglo-Saxon ancestry.

"Palaeoanthropologists have found that when the base of the human skull is analysed in 3D, it can be used to track relationships among human populations in a similar way to ancient DNA," explains Dr Plomp. "Based on this, we collected 3D data from suitably dated skeletal collections from Britain and Denmark, and then analysed the data to estimate the ancestry of the Anglo-Saxon individuals in the sample."

Professor Collard adds, "these findings tell us that being Anglo-Saxon was a matter of language and culture, not genetics".

According to Professor Dobney, the team's results indicate that "the Anglo-Saxon kingdoms of early Medieval Britain were strikingly similar to contemporary Britain--full of people of different ancestries sharing a common language and culture."

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Press-only preview: https://plos.io/3q18HvE

Contact: Kimberly Plomp, kplomp@sfu.ca, (236)-991-3638; Mark Collard, mcollard@sfu.ca, (778)-782-8166; Keith Dobney, keith.dobney@sydney.edu.au, +61 2 9351 5658

Image Caption: Photogrammetry with skull

Image Credit: Kimberly Plomp

Citation: Plomp KA, Dobney K, Collard M (2021) A 3D basicranial shape-based assessment of local and continental northwest European ancestry among 5th to 9th century CE Anglo-Saxons. PLoS ONE 16(6): e0252477. https://doi.org/10.1371/journal.pone.0252477

Funding: The study was supported by the European Union's Marie Sk?odowska-Curie Actions program (Horizon 2020 - 748200), the Social Sciences and Humanities Research Council of Canada (895-2011-1009), the Canada Research Chairs Program (228117 and 231256), the Canada Foundation for Innovation (203808), the British Columbia Knowledge Development Fund (862-804231), and Simon Fraser University (14518).

Competing Interests: The authors have declared that no competing interests exist.

In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0252477