Monday, February 20, 2023

UPDATES
East Palestine residents ‘right to be skeptical,’ Ohio Sen. Sherrod Brown says, but officials believe water and air are safe

By Dakin Andone, CNN
 Sun February 19, 2023

US Sen. Sherrod Brown echoed officials’ beliefs Sunday that the water and air are safe in East Palestine, Ohio, after a train carrying hazardous materials derailed there earlier this month, but he acknowledged that residents are “right to be skeptical.”

“We think the water’s safe,” the senator, a Democrat, told CNN’s “State of the Union,” days after he visited the community, citing comments made by the administrators of the state and federal Environmental Protection Agencies. “But when you return to your home, you should be tested again for your water and your soil and your air, not to mention those that have their own wells.”

The senator’s comments come 16 days after the Norfolk Southern train derailed in the small community of less than 5,000 people, where residents have described rashes, sore throats and nausea after returning home following controlled detonations of some of the tanks that were carrying toxic chemicals, including vinyl chloride, which has the potential to kill at high levels and increase cancer risk.

An evacuation order was lifted five days after the derailment, when officials deemed the air and water safe. But many residents remain unconvinced, complaining about the lingering smell of chemicals, headaches and pain.


Norfolk Southern CEO again promised to do right by East Palestine residents. The community wants to 'hold him to that'


Anger and frustration continued to boil over this week, as residents demanded answers of officials and Norfolk Southern. Hundreds of residents attended a town hall, expressing concern about air and water safety and their mounting distrust of civil leaders.

“Why are people getting sick if there’s nothing in the air or in the water,” one resident yelled during the town hall.

The Ohio Department of Health announced it is opening a health clinic geared at providing medical care and assistance relating to the recent train derailment starting Tuesday at noon, according to a statement from the agency.

“I heard you, the state heard you, and now the Ohio Department of Health and many of our partner agencies are providing this clinic, where people can come and discuss these vital issues with medical providers,” said the department’s director Dr. Bruce Vanderhoff.

The clinic will be located at the First Church of Christ on 20 W. Martin St in East Palestine and will include two assessment rooms. A mobile unit operated by the Community Action Agency of Columbiana County will also be on site to allow for more appointments. Registered nurses, mental healthcare specialists as well as a toxicologist will be made available to community members seeking their assistance.

Officials have sought to reassure residents, acknowledging that while some waterways were contaminated, killing thousands of fish downstream, they believe those contaminants to be contained. No vinyl chloride has been detected in any down-gradient waterways near the train derailment, Tiffani Kavalec, the Ohio Environmental Protection Agency’s division chief of surface water, told CNN earlier this week.

And state officials have repeatedly determined water from the municipal system – which is pulled from five deep wells covered by solid steel casing – is safe to drink, though the state EPA has encouraged those who use private wells to get that water tested, since they may be closer to the surface.

The CEO of Norfolk Southern – which pulled out of the town hall this week, citing safety concerns – met with residents and local leaders Saturday, promising in an open letter that “we are here and will stay here for as long as it takes to ensure your safety and to help East Palestine recover and thrive.”

After visiting the community Thursday, Brown pledged to hold the rail company accountable for the impacts on the community, saying in a news conference he would “make sure Norfolk Southern does what it says it’s going to do, what it’s promised.”

Brown reiterated that Sunday. The company has promised to provide a $1,000 payment to residents within the zip code, but the senator said it would need to go far beyond that and live up to its commitment to “making everybody whole.”



Opinion: 'Everyone's scared' -- a novelist's view of the rail disaster in Ohio


“Whatever (residents) need, everything that’s happened here – all the cleanup, all the drilling, all the testing, all the hotel stays, all of that is on Norfolk Southern. They caused it, there’s no question they caused it,” Brown said, adding the total cost could amount to either tens or hundreds of millions of dollars.

The company has also started a $1 million fund “as a down payment on our commitment to help rebuild,” Alan Shaw, Norfolk Southern’s CEO, said in his open letter Saturday. It has also “implemented a comprehensive testing program to ensure the safety of East Palestine’s water, air, and soil.”

In addition to local and state officials, federal medical experts have also been deployed.

Ohio Gov. Mike DeWine Thursday asked the US Centers for Diseases Control and Prevention and the US Department of Health to send teams. In response, the Biden administration said it deployed experts to help assess what dangers remain, and the CDC similarly confirmed Friday it would send a team to assess public health needs.

As for the derailment itself, the National Transportation Safety Board continues to work “vigorously” to determine its cause. Investigators are reviewing multiple videos of the train prior to its derailment, including one that shows “what appears to be a wheel bearing in the final stage of overheat failure moments before the derailment,” the agency has said.

Mom who fled with baby after toxic derailment wants officials to 'drink the water' in Ohio town

Evacuation order lifted, but couple with newborn not ready to return

Kasie Locke, left, is seen on Sunday with her husband, Nate, holding their two-month-son, Lucas. The family fled their home in East Palestine, Ohio, hours after the Feb. 3 freight train derailment in the town. (CBC)

A couple with an infant son who fled their home after a toxic train derailment in Ohio earlier this month are not convinced it's safe to return home, despite what state officials have said.

The Feb. 3 derailment prompted officials to evacuate hundreds of people from their homes in the town of East Palestine amid fears that a hazardous, highly flammable material might ignite. 

To prevent toxic vinyl chloride gas — used in the production of PVC plastic — from exploding, officials carried out a controlled release of the fumes. The gas was vented and burned after being diverted to a trench, sending a plume of smoke over the town for days.

East Palestine residents Kasie and Nathaniel Locke remember the night of the derailment, with Kasie telling CBC News they've been "stuck in limbo" ever since, staying with her mother in North Lima, about a 16-minute drive from the site.

WATCH | Ohio family describes disruption, health impacts of toxic spill:

Ohio family describes disruption, health impacts of toxic spill

20 hours ago
Duration6:58
Kasie and Nathaniel Locke describe the disruption and health impacts they have been enduring after a fiery train derailment caused toxic chemical leaks in East Palestine, Ohio, two weeks ago.

Dozens of cars of the Pennsylvania-bound freight train derailed shortly before 9 p.m. on a Friday, and the young family left home around 2 a.m. the next day.

It smelled like "really intense" burning rubber and oil and they "couldn't breathe," said Nathaniel.

"We both had to wrap our faces in receiving blankets from Lucas."

They said they experienced headaches, runny noses, and burning and numb eyes and throats.

Kasie said it's been "anxiety-inducing" thinking about the health of her child.

"It's very scary. I mean, we don't feel safe going back ... not with a two-month-old," she said. "Consciously, I can't do it. I don't know what effects it will have on his health."

She said baby Lucas has since been taken to Akron Children's Hospital to get his nose suctioned out, and they've used saline and a nasal aspirator to manage his congestion, adding that she's not sure if he's sick or if the symptoms are related to the derailment.

Evacuation orders were lifted Feb. 8, when Ohio Gov. Mike DeWine and other officials said it was safe for the residents of the community to return home.

State testing of municipal drinking water

DeWine on Friday said a plume of pollution that had been moving down the Ohio River had dissipated, and said state testing never showed that any contaminated water entered any municipal drinking systems in its path.

In response to the derailment and safety concerns it raises, U.S. Senate commerce committee chair Maria Cantwell late on Friday said she has opened an inquiry into railroad hazardous materials safety practices.

People wait in line on Thursday to collect a $1,000 US cheque and get reimbursed for expenses, two weeks after they were told to evacuate from East Palestine, Ohio, due to the derailment of a Norfolk Southern Railway train carrying toxic chemicals. (Michael Swensen/Getty Images)

The head of the U.S. Environmental Protection Agency got a first-hand look Thursday at the toll left by the derailment.

EPA Administrator Michael Regan said Thursday that anyone who is fearful of being in their home should seek testing from the government.

"People have been unnerved. They've been asked to leave their homes," he said, adding that if he lived there, he would be willing to move his family back into the area as long as the testing shows it's safe.

The Ohio EPA said the latest tests show five wells supplying the town's drinking water are free from contaminants.

Smoke rises from a cargo train in East Palestine, Ohio, on Feb. 4, the day after its derailment. The train was shipping cargo from Madison, Ill., to Conway, Penn., when it derailed. (Dustin Franz/AFP/Getty Images)

U.S. Transportation Secretary Pete Buttigieg said Sunday he will call on major railroads to improve safety in light of the derailment.

Writing to railroad executive Alan Shaw — whose company, Norfolk Southern, operated the derailed train — Buttigieg added that he would call on Congress to raise the cap on fines against railroads for violating safety regulations.

Norfolk Southern said Sunday that it "received a copy of the letter from the secretary and are reviewing." Shaw said last week the railroad had established an initial $1 million US community support fund and distributed $1.7 million US in direct financial assistance to more than 1,100 families and businesses to cover evacuation costs.

"We will not let you down," he told residents in a letter.

'Would they bring their family back?'

Kasie Locke has a challenge for officials who believe the town of 4,700 is a safe place to live.

"I would like them to come stay in East Palestine and drink the water, shower with the water. I'd like to hear them tell us, would they like to live here? Would they bring their children here? Would they bring their family back? Because it would be hard for me to believe they would say yes."

This photo taken with a drone shows the continuing cleanup of portions of the Norfolk Southern freight train on Feb. 9. (Gene J. Puskar/The Associated Press)

The U.S. Health and Human Services Department and the Centers for Disease Control and Prevention (CDC) said Friday they were deploying a team of medical personnel and toxicologists to conduct public health testing and assessments.

Federal Railroad Administration chief Amit Bose will visit the site next week and the Environmental Protection Agency is stepping up testing.

With files from Reuters


Ohio is facing a chemical disaster. Biden must declare a state of emergency

A train derailed and flooded a town with cancer-causing chemicals. But something larger, and more troubling, is at work

‘East Palestine residents are reporting headaches, sore throats, and burning eyes; dead pets and chickens; and thousands of fish corpses in nearby waterways.’ 
Photograph: Gene J Puskar/AP
The Guardian
Sat 18 Feb 2023

Earlier this month, a train carrying toxic chemicals derailed in eastern Ohio, exploding into flames and unleashing a spume of chemical smoke on the small town of East Palestine. The train’s freight included vinyl chloride, a chemical known to cause liver cancer and other sicknesses.

In response, government and railway officials decided to “burn off” the vinyl chloride – effectively dumping 1.1m lbs of the chemical into the local community, according to a new lawsuit. Officials said that they did so to avert the vinyl chloride from exploding; in contrast, an attorney for the lawsuit has said that the decision was cheap, unsafe, and more interested in restoring train service and appeasing railway shareholders than protecting local residents.

East Palestine residents are reporting headaches, sore throats, and burning eyes; dead pets and chickens; and thousands of fish corpses in nearby waterways. The Ohio Department of Natural Resources has said that approximately 3,500 fish, of 12 different species, died across 7.5 miles.

In other words, Norfolk Southern’s “controlled burn” may have caused a mushroom cloud of poison to spread over eastern Ohio. The situation demands immediate action from President Biden. Without it, thousands of people – including children and the elderly – and animals will be at continued risk of premature death. Biden must declare a state of emergency and create an independent taskforce to take over the remediation of this eco-catastrophe.

Norfolk Southern “basically nuked a town with chemicals” to “get a railroad open”, a former hazmat technician told a local news outlet. It certainly seems like a company with a $55bn market cap chose to sacrifice the health of thousands of people to keep its profits flowing.

We need to try to understand how this happened.

For one thing, even the initial derailment wasn’t necessarily just an “accident.” It was a function of our out-of-control corporate culture in the United States, which has neutered effective government oversight of hazardous activities – including the rail transport of highly flammable and carcinogenic chemicals. The EPA’s response thus far has been to send a feckless letter to Norfolk Southern pleading it pay for clean-up.


That’s not going to cut it. We need to do better.

In terms of the sheer quantity of carcinogenic chemicals being released over an area of hundreds of miles, the catastrophe in Ohio is a major, unprecedented public health crisis. Biden must publicly recognize it as such and act to protect the people who live in the affected area. This requires a rapid, all-of-government response overseen not by the EPA but by independent scientists and taskmasters who will be immune to pressure from industry. This sort of taskforce must be willing to threaten the suspension or even nationalization of Norfolk Southern if it does not cooperate.

After battling an oil company over the discharge of toxic waste in the Amazon, I can say with some assurance that Norfolk’s response to this crisis so far comes from a time-tested corporate strategy: manage the situation as a public relations challenge and not the humanitarian and ecological catastrophe that it is. Norfolk’s leadership bailed out of a townhall meeting this week, blaming security risks, and has refused to face residents to answer questions.

That’s certainly cowardice. But it is also a function of the fact that industry does not respect the power of government to regulate it. Government is supposed to protect us from the excesses of industry; instead it often acts like its partner.


If the consequences of not attending had included a sufficient threat to his bottom line, Norfolk Southern CEO Alan Shaw – who earns a reported $4.5m a year – probably would have been at the town hall. And if the government had been doing its job in the first place, there is a good chance this accident would not have happened. During the Trump administration, Norfolk successfully lobbied to repeal a safety rule requiring new electronic brakes. The train was also dangerously long – with only two crew members, and a trainee, supervising its 1.7-mile length.

I’m not a scientist. But I know a fair amount about toxicology and how the world’s polluters use a playbook invented by law firms and consultants to downplay the impact of major disasters and lower their legal liability. Local and state officials – who may be under enormous pressure from these industries in the form of campaign donations – often work alongside polluters to “manage” disasters’ political fallout.

It’s a one-two punch of disaster mismanagement that is playing out now, in Ohio, with awful consequences for people and the planet. Here are three takeaways about what is really happening and what needs to be done:

Be skeptical of claims by authorities that it is “safe” to return to the area. The EPA and state environmental officials have been opaque about what chemicals are being tested for and by what methods, and news reports haven’t indicated any plans so far for any sort of environmental restoration. We also do not know what new chemical compounds the so-called “controlled” burn may have created, and whether tests have been run for those chemicals. In fact, test results have not even been released publicly.

Bottom line: there is no transparent scientific or public health basis for declaring the area safe. Until there is, I wouldn’t go near the site of the disaster.

The EPA can help, but cannot oversee a clean-up. Corporate lobbying in recent years has undermined the ability of the EPA to regulate industry. Under the Trump administration, chemical lobbyists took over important jobs on the inside and the agency is severely understaffed. Further, the EPA is required by Congress to “balance” industry needs with public safety. It is not focused solely on protecting the community. It sent a letter to Norfolk pleading with it to pay for a cleanup; a real government would have sent a disaster management team to Ohio to take over.

Longer-term, the railway industry needs to be revamped. We have civil-war era braking systems on trains carrying deadly chemicals though our communities. Railway unions and whistleblowers have repeatedly raised safety concerns only to be ignored. A new industry concept called “precision scheduling” has pushed trains and workers to the breaking point to extract greater profits for shareholders, which include some of the largest hedge funds on Wall Street.

Our government institutions as currently constituted are unable or unwilling to respond effectively to industrial disasters. It is preposterous for any ostensibly advanced country to let a massive chemical polluter clean up a mess like this on its own terms and without effective oversight. This is not an isolated incident. Unless we demand accountability, it will happen again.

President Biden: the ball is in your court.

Steven Donziger is a human rights and environmental lawyer, a Guardian US columnist, and the creator of the Substack newsletter Donziger on Justice

New Way for Extracting Thermal Energy From Low-Temperature Waste Heat Sources

Heat Energy Ball Transfer Explosion Concept

Scientists in China have proposed and realized a new concept—barocaloric thermal batteries based on the unique inverse barocaloric effect. With this they can extract thermal energy from low-temperature waste heat sources and reuse it on demand, simply by controlling the pressure

A Chinese research team has developed a new concept for extracting thermal energy from low-temperature waste heat sources and reusing it on demand simply by controlling the pressure.

Heat production accounts for more than 50% of the world’s final energy consumption and analysis of waste heat potential shows that 72% of the world’s primary energy consumption is lost after conversion, mainly in the form of heat. It is also responsible for more than 30% of global greenhouse gas emissions.

Against this background, researchers led by Prof. LI Bing from the Institute of Metal Research of the Chinese Academy of Sciences have proposed and realized a new concept—barocaloric thermal batteries based on the unique inverse barocaloric effect.

The study will be published today (February 17, 2023) in the journal Science Advances.

Barocaloric Thermal Batteries: Concept and Realization

Barocaloric thermal batteries: Concept and realization. Credit: Institute of Metal Research

An inverse barocaloric effect is characterized by a pressure-induced endothermic response, in sharp contrast to a normal barocaloric effect where pressurization leads to an exothermic response. “A barocaloric thermal battery cycle consists of three steps, including thermal charging upon pressurization, storage with pressure, and thermal discharging upon depressurization,” said Prof. LI, corresponding author of the study.

The barocaloric thermal battery was materialized in ammonium thiocyanate (NH4SCN). Discharge was manifested as the heat of 43 J g-1 or a temperature rise of about 15 K. The heat released was 11 times greater than the mechanical energy input.

To understand the physical origin of the unique inverse barocaloric effect, the working material NH4SCN has been well characterized using synchrotron X-ray and neutron scattering techniques. It undergoes a crystal structural phase transition from a monoclinic to an orthorhombic phase at 363 K, accompanied by a volumetric negative thermal expansion of ~5% and entropy changes of about 128 J kg-1 K-1.

This transition is easily driven by pressure as low as 40 MPa, and it is the first inverse barocaloric system with entropy changes greater than 100 J kg-1K-1. Pressure-dependent neutron scattering and molecular dynamics simulations showed that the transverse vibrations of SCN¯ anions are enhanced by pressure and the hydrogen bonds that form the long-range order are then weakened.

As a result, the system becomes disordered in response to external pressure and thus the material absorbs heat from the environment.

As an emerging solution for manipulating heat, barocaloric thermal batteries are expected to play an active role in a variety of applications such as low-temperature industrial waste heat harvesting and reuse, solid-state refrigeration heat transfer systems, smart grids, and residential heat management.

Reference: “Thermal batteries based on inverse barocaloric effects” 17 February 2023, Science Advances.
DOI: 10.1126/sciadv.add0374

This study was supported by CAS, the Ministry of Science and Technology of China, and the National Natural Science Foundation of China.

Capturing waste heat to turn it back into energy

Waste heat is the biggest source of energy on the planet. A newly developed waste heat engine could recycle all that lost heat back into the energy, reducing our use of fossil fuels

Luminescent’s waste heat engine captures and stores wasted heat from industrial generators. 
Photo courtesy of Luminescent

By Brian Blum
February 19

According to a study from Yale University’s School of the Environment, some 70 percent of all energy produced by humanity is squandered as “waste heat,” much of it a byproduct of running large industrial plants.

Waste heat “is the biggest source of energy on the planet,” says Joseph King, one of the program directors for the US government’s Advanced Research Projects Agency Energy.

Israeli startup Luminescent has developed a technology to capture this waste heat – which is full of climate change-exacerbating CO2 – and turn it into electricity, either to power the facility itself at a lower cost or to be sold back to the electrical grid.

Capturing wasted heat is a known need; Facebook announced a plan in 2020 to channel the waste heat from its center in Odense, Denmark, to warm nearly 7,000 homes, and another Danish endeavor uses heat from a crematorium to heat local homes.

But mainly, the business of heat capture focuses on large facilities with substantial generators, where producing and storing zero-emission electricity is more cost effective.

Luminescent is the first to address the small power generators that comprise most of the market. Its super-efficient waste heat engine will be available by mid-2023 as a pilot, with sales starting in 2025.

Although waste heat released into the air doesn’t have much direct effect on climate change, every bit of waste heat recycled into energy reduces our use of fossil fuels.

One study in the UK found that if some of the country’s biggest power stations were to divert waste heat to warming homes and offices, it could prevent the release of some 10 million tons of CO2 emissions annually.
Kinetic energy

Luminescent’s unique waste heat engine uses a heat-transfer liquid (HTL), which flows in a nozzle where it’s mixed with pressurized air or other gas bubbles.

The liquid has a thousand times more thermal energy density than any gas for a similar volume.

The bubbles expand isothermally (without any change in temperature), thereby accelerating the HTL and converting it into kinetic energy. The kinetic energy operates a generator on top of the engine shaft.

The bottom line: Luminescent says its isothermal process reduces the size and doubles the efficiency of an engine compared to other operations, while providing up to 70% more power than existing setups.

The Luminescent system can store the resulting energy for up to 20 hours.

Having recently raised a $7 million seed funding round led by Grove Ventures, the company is targeting industrial operations in the United States, Europe, Japan, China and South Korea.
Zero-emission energy
From left, From left, Luminescent founder and CEO Doron Tamir, founder and CTO Prof. Carmel Rotschild, VP Product Tomer Stern, VP Engineering Erez Klein. Photo by Noi Einav

The Tel Aviv-based company was cofounded by Doron Tamir, a former executive at the solar energy firm Solex Renewable, and Prof. Carmel Rotschild of the mechanical engineering department at the Technion, who invented the isothermal process used by Luminescent.

Tamir tells ISRAEL21c that after a decade in the solar industry, “I came to the conclusion that solar energy with batteries is important, but if you want to be serious about energy transition, it’s part of the solution but not the solution.”

Since waste heat is a necessary byproduct of heat engines, the efficiency of power plants and large industrial factories is limited, and they must therefore burn more fuel to achieve their desired energy output.

Once Tamir identified waste heat as perhaps the biggest piece of the climate change puzzle, he realized that “we have the potential to generate hundreds of gigawatts of zero-emission energy. But today almost no one uses it. All heat engines are very inefficient and expensive if they’re under 10 megawatts,” enough to power 300 homes.

From left, founder and CTO Prof. Carmel Rotschild and Luminescent founder and CEO Doron Tamir. Photo by Noi Einav

Working with an industrial plant using any source of energy – gas, coal or solar – Luminescent’s system “can give electricity back at a very low cost.”

Tamir gives the example of the US gas pipeline that runs from the east to west coasts. “They have 25 gigawatt small turbines that operate a compressor. The efficiency is as low as 24%. We can take that 24% and turn it into 41%.”

That may not sound like a huge jump, but Tamir points out that, “just from this market in the US, we could generate the entire capacity of electrical demand in Israel, all with zero emissions.”
Gearing up for sales

Luminescent will build its first engines in Israel with partnerships outside the Middle East anticipated as the company begins signing up international customers.

Tamir is looking at a $1,500 price point per engine with the number going down as the company scales.

And while waste energy is the target, that’s just the starting point. “Waste heat that can work for decades is a big one. But renewable storage could also be an endless market. Data center cooling, geothermal energy production – these can all be endless markets,” Tamir tells ISRAEL21c.

As the Yale study noted, “Waste heat is a problem of a thousand cuts, requiring a mass of innovations to tackle different slices of the problem.”

To learn more about capturing waste heat the Israeli way, visit the Luminescent website.

Plague Trackers: Uncovering the Elusive Origins of the Black Death

East Smithfield Plague Pits

The East Smithfield plague pits, which were used for mass burials in 1348 and 1349. Credit: Museum of London Archaeology (MOLA)

The researchers analyzed over 600 genome sequences of Yersinia pestis, the bacterium responsible for causing the plague.

In an effort to gain deeper insight into the origins and spread of bubonic plague throughout history, researchers from McMaster University, the University of Sydney, and the University of Melbourne have conducted a thorough and detailed analysis of hundreds of modern and ancient genome sequences, creating the largest study of its type.

Despite significant advancements in DNA technology and analysis, the origin, evolution, and spread of the plague remain challenging to pinpoint.

The plague is responsible for the two largest and most deadly pandemics in human history. However, the ebb and flow of these, why some die out and others persist for years has confounded scientists.

In a paper published today in the journal Communications Biology, McMaster researchers use comprehensive data and analysis to chart what they can about the highly complex history of Y. pestis, the bacterium that causes plague.

The research features an analysis of more than 600 genome sequences from around the globe, spanning the plague’s first emergence in humans 5,000 years ago, the plague of Justinian, the medieval Black Death, and the current (or third) Pandemic, which began in the early 20th century

East Smithfield Plague Pits Skeletons

The East Smithfield plague pits, which were used for mass burials in 1348 and 1349. Credit: Museum of London Archaeology (MOLA)

“The plague was the largest pandemic and biggest mortality event in human history. When it emerged and from what host may shed light on where it came from, why it continually erupted over hundreds of years and died out in some locales but persisted in others.   And ultimately, why it killed so many people,” explains evolutionary geneticist Hendrik Poinar, director of McMaster’s Ancient DNA Centre.

Poinar is a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research and McMaster’s Global Nexus for Pandemics & Biological Threats.

The team studied genomes from strains with a worldwide distribution and of different ages and determined that Y. pestis has an unstable molecular clock. This makes it particularly difficult to measure the rate at which mutations accumulate in its genome over time, which are then used to calculate dates of emergence.

Because Y. pestis evolves at a very slow pace, it is almost impossible to determine exactly where it originated.

Humans and rodents have carried the pathogen around the globe through travel and trade, allowing it to spread faster than its genome evolved. Genomic sequences found in Russia, Spain, England, Italy, and Turkey, despite being separated by years are all identical, for example, creating enormous challenges in determining the route of transmission.

To address the problem, researchers developed a new method for distinguishing specific populations of Y. pestis, enabling them to identify and date five populations throughout history, including the most famous ancient pandemic lineages which they now estimate had emerged decades or even centuries before the pandemic was historically documented in Europe.

“You can’t think of the plague as just a single bacterium,” explains Poinar. “Context is hugely important, which is shown by our data and analysis.”

To properly reconstruct pandemics of our past, present, and future, historical, ecological, environmental, social, and cultural contexts are equally significant.

He explains that genetic evidence alone is not enough to reconstruct the timing and spread of short-term plague pandemics, which has implications for future research related to past pandemics and the progression of ongoing outbreaks such as COVID-19.

Reference: “Plagued by a cryptic clock: insight and issues from the global phylogeny of Yersinia pestis” by Katherine Eaton, Leo Featherstone, Sebastian Duchene, Ann G. Carmichael, Nükhet Varlık, G. Brian Golding, Edward C. Holmes, and Hendrik N. Poinar, 19 January 2023, Communications Biology.
DOI: 10.1038/s42003-022-04394-6

Study of Ancient Proteins Clarifies Mystery of Crocodiles’ Unique Hemoglobin

Crocodile With Impala

A Nile crocodile swallows an impala, its reward for lying in wait beneath the water’s surface. By resurrecting the hemoglobin of ancient crocodilian ancestors, a Husker-led team has helped explain why other vertebrates failed to evolve the adaptations that allow crocs to go hours without air. Credit: Cell Press / Current Biology / Shutterstock / Scott Schrage, University of Nebraska–Lincoln

Experiments on ancient proteins reveal that mutations are more numerous and nuanced than previously believed.

It can pogo-stick along at 50-plus miles per hour, leaping 30-odd feet in a single bound. But that platinum-medal athleticism falls by the wayside at a sub-Saharan riverside, the source of life and death for the skittish impala stilling itself for a drink in 100-degree heat.

For the past hour, a Nile crocodile has been silently lurking in the muddy river. When the apex predator strikes, its powerful jaws clamp onto the hindquarter of an unsuspecting impala with a force of 5,000 pounds. The real weapon, however, is the water itself, as the crocodile drags its prey to the deep end to drown.

The success of the croc’s ambush lies in the nanoscopic scuba tanks — hemoglobins — that course through its bloodstream, unloading oxygen from lungs to tissues at a slow but steady clip that allows it to go hours without air. The hyper-efficiency of that specialized hemoglobin has led some biologists to wonder why, of all the jawed vertebrates in all the world, crocodilians were the lone group to hit on such an optimal solution to making the most of a breath.

By statistically reconstructing and experimentally resurrecting the hemoglobin of an archosaur, the 240-million-year-old ancestor of all crocodilians and birds, the University of Nebraska–Lincoln’s Jay Storz and colleagues have gleaned new insights into that why. Rather than requiring just a few key mutations, as earlier research suggested, the unique properties of crocodilian hemoglobin stemmed from 21 interconnected mutations that litter the intricate component of red blood cells.

That complexity, and the multiple knock-on effects that any one mutation can induce in hemoglobin, may have forged an evolutionary path so labyrinthine that nature failed to retrace it even over tens of millions of years, the researchers said.

“If it was such an easy trick — if it was that easy to do, just making a few changes — everyone would be doing it,” said Storz, a senior author of the study and Willa Cather Professor of biological sciences at Nebraska.

All hemoglobin binds with oxygen in the lungs before swimming through the bloodstream and eventually releasing that oxygen to the tissues that depend on it. In most vertebrates, hemoglobin’s affinity for capturing and holding oxygen is dictated largely by molecules known as organic phosphates, which, by attaching themselves to the hemoglobin, can coax it into releasing its precious cargo.

But in crocodilians — crocodiles, alligators, and their kin — the role of organic phosphates was supplanted by a molecule, bicarbonate, that is produced from the breakdown of carbon dioxide. Because hardworking tissues produce lots of carbon dioxide, they also indirectly generate lots of bicarbonate, which in turn encourages hemoglobin to dispense its oxygen to the tissues most in need of it.

“It’s a super-efficient system that provides a kind of slow-release mechanism that allows crocodilians to efficiently exploit their onboard oxygen stores,” Storz said. “It’s part of the reason they’re able to stay underwater for so long.”

As postdoctoral researchers in Storz’s lab, Chandrasekhar Natarajan, Tony Signore, and Naim Bautista had already helped decipher the workings of the crocodilian hemoglobin. Alongside colleagues from Denmark, Canada, the United States, and Japan, Storz’s team decided to embark on a multidisciplinary study of how the oxygen-ferrying marvel came to be.

Prior efforts to understand its evolution involved incorporating known mutations into human hemoglobin and looking for any functional changes, which were usually scant. Recent findings from his own lab had convinced Storz that the approach was flawed. There were plenty of differences, after all, between human hemoglobin and that of the ancient reptilian creatures from which modern-day crocodilians evolved.

“What’s important is to understand the effects of mutations on the genetic background in which they actually evolved, which means making vertical comparisons between ancestral and descendant proteins, rather than horizontal comparisons between proteins of contemporary species,” Storz said. “By using that approach, you can figure out what actually happened.”

So, with the help of biochemical principles and statistics, the team set out to reconstruct hemoglobin blueprints from three sources: the 240-million-year-old archosaur ancestor; the last common ancestor of all birds; and the 80-million-year-old shared ancestor of contemporary crocodilians. After putting all three of the resurrected hemoglobins through their paces in the lab, the team confirmed that only the hemoglobin of the direct crocodilian ancestor lacked phosphate binding and boasted bicarbonate sensitivity.

Comparing the hemoglobin blueprints of the archosaur and crocodilian ancestors also helped identify changes in amino acids — essentially the joints of the hemoglobin skeleton — that may have proved important. To test those mutations, Storz and his colleagues began introducing certain croc-specific mutations into the ancestral archosaur hemoglobin. By identifying the mutations that made archosaur hemoglobin behave more like that of a modern-day crocodilian, the team pieced together the changes responsible for those unique, croc-specific properties.

Counter to conventional wisdom, Storz and his colleagues discovered that evolved changes in hemoglobin’s responsiveness to bicarbonate and phosphates were driven by different sets of mutations, so that the gain of one mechanism was not dependent on the loss of the other. Their comparison also revealed that, though a few mutations were enough to subtract the phosphate-binding sites, multiple others were needed to eliminate phosphate sensitivity all together. In much the same way, two mutations seemed to directly drive the emergence of bicarbonate sensitivity — but only when combined with or preceded by other, easy-to-miss mutations in remote regions of the hemoglobin.

Storz said the findings speak to the fact that a combination of mutations might yield functional changes that transcend the sum of their individual effects. A mutation that produces no functional effect on its own might, in any number of ways, open a path to other mutations with clear, direct consequences. In the same vein, he said, those later mutations might influence little without the proper stage-setting predecessors already in place. And all of those factors can be supercharged or waylaid by the environment in which they unfold.

“When you have these complex interactions, it suggests that certain evolutionary solutions are only accessible from certain ancestral starting points,” Storz said. “With the ancestral archosaur hemoglobin, you have a genetic background that makes it possible to evolve the unique properties that we see in hemoglobins of modern-day crocodilians. By contrast, with the ancestor of mammals as a starting point, it may be that there’s some way that you could evolve the same property, but it would have to be through a completely different molecular mechanism, because you’re working within a completely different structural context.”

For better or worse, Storz said, the study also helps explain the difficulty of engineering a human hemoglobin that can mimic and approach the performance of the crocodilian.

“We can’t just say, ‘OK, it’s mainly due to these five mutations. If we take human hemoglobin and just introduce those mutations, voilà, we’ll have one with those same exact properties, and we’ll be able to stay underwater for two hours, too,’” Storz said. “It turns out that’s not the case.

“There are lots of can’t-get-there-from-here problems in the tree of life.”

Reference: “Evolution and molecular basis of a novel allosteric property of crocodilian hemoglobin” by Chandrasekhar Natarajan, Anthony V. Signore, Naim M. Bautista, Federico G. Hoffmann, Jeremy R.H. Tame, Angela Fago and Jay F. Storz, 21 December 2022, Current Biology.
DOI: 10.1016/j.cub.2022.11.049

The study was funded by the National Science Foundation and the National Institutes of Health.