Wednesday, August 09, 2023


TORONTO
Striking workers demand 'fair share' as Metro reports better-than-expected profits

Story by Jake Edmiston 

Workers seen on strike outside a Metro grocery store in Toronto.
© Provided by Financial Post


Profits at Metro Inc. surged past analysts’ expectations in the third quarter, prompting criticism from the union that represents thousands of workers on strike at more than two dozen of its Toronto-area supermarkets.

In response to Metro’s earnings update on Aug. 9, Unifor , Canada’s largest private sector union, said grocery clerks deserve “their fair share” of the company’s double-digit profit gains.

“Frontline grocery workers need Metro to come back to the table with an improved wage offer,” Unifor spokesperson Paul Whyte said in a statement.

But Metro chief executive Eric La Flèche said he wants a deal with the union that ensures the company can stay competitive in the grocery industry amid stubborn food inflation that has forced customers to become more and more price sensitive.

The comments from both sides suggest the stalemate, which has shut down 27 Metro stores for more than 10 days, is likely to drag on.

Negotiators with Metro and Unifor Local 414, which represents roughly 3,700 Metro workers at 27 stores in and around Toronto, have not returned to the bargaining table since union members rejected a tentative deal and walked off the job on July 29.

“We’re clearly disappointed,” La Flèche told analysts during a quarterly conference call on Aug. 9.

The union says its members want more money in the first year of any contract to replace the $2 hourly wage bonus grocery workers received during the pandemic. But one of the union’s negotiators also said Metro has made it clear “there’s no more money.”

La Flèche said Metro wants a deal to re-open the stores “as soon as possible, while ensuring the long-term competitiveness of our company.”

“We had reached a very good agreement that was unanimously recommended by union representatives,” he said in the company’s earnings update.

On Aug. 9, Metro reported a boost in profits during the third quarter that outperformed analysts’ expectations. Sales increased nearly 10 per cent year over year to $6.4 billion in the quarter, resulting in profits of $346.7 million, up 26 per cent — helped in part by a favourable tax ruling. On an adjusted basis, Metro profits were $314.8 million in the quarter, up 10.9 per cent. Adjusted earnings per share of $1.35 surpassed forecasts of $1.29.

“Metro workers are fighting for decent work and pay. It is the minimum every worker should expect,” Unifor national president Lana Payne wrote on Twitter , in response to Metro’s earnings update. “And there are no excuses. Take a look at those profits.”

Unifor also represents employees at the Financial Post’s Toronto newsroom.

Metro reported a 20-basis-point decline in its gross profit margin, which La Flèche told analysts on the call was proof the grocer has been absorbing a portion of inflationary cost increases from suppliers because “there are limits to what we can charge to our customers.”

RBC Capital Markets analyst Irene Nattel said the quarter was a “very strong” showing for Metro, a Montreal-based retailer with more than 1,600 supermarkets and pharmacies in Ontario and Quebec, including Food Basics, Super C and Jean Coutu.

Metro declined to comment on how much the strike-related store closures are costing the business. Last week, spokesperson Marie-Claude Bacon said all perishable items at the shuttered stores that could be sold were moved to Metro’s other locations in the area, while products that were deemed unsellable but “still good for consumption” were donated to food banks.

On Aug. 9, Bacon said negotiations haven’t restarted since union members rejected a tentative deal last month.

“We’re still committed to the bargaining process,” she said.

In mid-July, Metro and the union bargaining team agreed on a tentative deal that would have boosted full-time wages by $3.75 an hour for the most senior full-time employees over four years — with a $1.05 per hour bump in the first year, followed by 90 cents in each of the three following years, according to Local 414 president Gord Currie. Part-time employees, who make up more than 70 per cent of the roughly 3,700 workers on strike, would have seen a maximum increase of $2.75 over four years, Currie said, adding the proposed increases were “the best we’ve had in 25 years.”

But Local 414 members voted to reject the deal and go on strike. Currie said his members weren’t satisfied with the wage increase and want at least $2 extra per hour in the first year of the deal. The demand has to do with a $2 hourly wage bonus that Metro and its rivals paid during the early months of the pandemic in 2020.

“They want the two dollars back ,” he said last week.

Canada’s top three grocers — Loblaw Cos. Ltd., Sobeys’ parent Empire Co. Ltd., and Metro — cut their so-called “hero pay” bonuses for front-line workers on the same day in June 2020, a controversy that pushed the federal government to strengthen its laws against wage-fixing.

“They made no bones about that. They want $2 in the first year,” Currie said. “(Metro) told us there’s no more money there. So we’re going to go back and look for more money obviously and try to get a deal.”

• Email: jedmiston@postmedia.com | Twitter: 

 

Parenting a 3-year-old robot


Carnegie Mellon University, Meta AI researchers develop robotic learning agent able to master multiple skills

Business Announcement

CARNEGIE MELLON UNIVERSITY

RoboAgent 01 

IMAGE: CARNEGIE MELLON UNIVERSITY AND META RESEARCHERS HAVE ANNOUNCED ROBOAGENT, AN AI AGENT THAT LEVERAGES PASSIVE OBSERVATIONS AND ACTIVE LEARNING TO ENABLE A ROBOT TO ACQUIRE MANIPULATION ABILITIES ON PAR WITH A TODDLER. view more 

CREDIT: CARNEGIE MELLON UNIVERSITY




Humans are social creatures and learn from each other, even from a young age. Infants keenly observe their parents, siblings or caregivers. They watch, imitate and replay what they see to learn skills and behaviors. 

The way babies learn and explore their surroundings inspired researchers at Carnegie Mellon University and Meta to develop a new way to teach robots how to simultaneously learn multiple skills and leverage them to tackle unseen, everyday tasks. The researchers set out to develop a robotic AI agent with manipulation abilities equivalent to a 3-year-old child.

The team has announced RoboAgent, an artificial intelligence agent that leverages passive observations and active learning to enable a robot to acquire manipulation abilities on par with a toddler.

“RoboAgent is a critical milestone toward general robotic agents that are efficient learners, effective in novel situations and capable of expanding their behaviors over time,” said Vikash Kumar, adjunct faculty in the School of Computer Science’s Robotics Institute. “Current robots are highly specialized and trained for individual tasks in isolation. In contrast, we set out to create a single artificial intelligence agent capable of exhibiting a wide range of skills in unseen scenarios. RoboAgent learns like human babies — leveraging a combination of abundant passive observations and limited active play.”

RoboAgent can complete 12 manipulation skills across differing scenes. This research points toward a robotic learning platform adaptable to changing environments. Unlike past research, the team demonstrated their work in real environments — not simulation — and did so with far less data than previous projects.

“RoboAgents are capable of much richer complexity of skills than what others have achieved,” said Abhinav Gupta, an associate professor in the Robotics Institute. “We’ve shown a greater diversity of skills than anything ever achieved by a single real-world robotic agent with efficiency and a scale of generalization to unseen scenarios that is unique.”

The team’s agent learns through a combination of self-experiences and passive observations contained in internet data. As a parent would guide their child, researchers teleoperated the robot through tasks to provide it with useful self-experiences. 

“The effectiveness and efficiency of our approach stem from our novel policy architecture that allows our agents to reason even with limited experiences,” said Homanga Bharadwaj, a Ph.D. student in robotics. “RoboAgent acts in response to specified text/visual goals by predicting and aggregating decisions in terms of temporal chunks of movements instead of commonly used per-timestep actions.”

Robots primarily learn from their own experiences, not from what happens passively around them. This inherent blindness to what goes on in their environment fundamentally limits both the diversity of experiences robots are exposed to and their abilities to adapt to new situations. To overcome these limitations RoboAgent learns from videos on the internet — akin to how babies acquire knowledge and behaviors by passively observing their surroundings.

“RoboAgent leverages the information contained in these videos to learn priors about how humans interact with objects and use various skills to successfully complete tasks,” said Mohit Sharma, a Ph.D. student in robotics. “Additionally, observing similar skills in multiple scenarios allows it to learn what is and isn't necessary to complete a task. It leverages these lessons when presented with unknown tasks or unseen environments.”

“An agent capable of this sort of learning moves us closer to a general robot that can complete a variety of tasks in diverse unseen settings and continually evolve as it gathers more experiences,” said Shubham Tulsiani, an assistant professor in the Robotics Institute. “RoboAgent can quickly train a robot using limited in-domain data while relying primarily on abundantly available free data from the internet to learn a variety of tasks. This could make robots more useful in unstructured settings like homes, hospitals and other public spaces.”

The team is open-sourcing its trained models, codebase, hardware drivers and — most notably — the entire dataset collected on this research. RoboSet is the largest publicly available robotics dataset on commodity hardware. The team hopes this will enable others to reuse, adapt and pass it forward, leading to a truly foundational general robotic agent over time.

The research team includes Kumar, Tulsiani, Gupta, Bharadwaj, Sharma and Jay Vakil from Meta AI. More information about RoboAgent and RoboSet is available on the project’s website.

Carnegie Mellon University and Meta researchers have announced RoboAgent, an AI agent that leverages passive observations and active learning to enable a robot to acquire manipulation abilities on par with a toddler.

RoboAgent 04

 

New research links early Europeans’ cultural and genetic development over several thousand years


Peer-Reviewed Publication

UPPSALA UNIVERSITY

6,000-year-old pottery 

IMAGE: EXAMPLE OF POTTERY ROUGHLY 6,000 YEARS OLD FROM THE LUBLIN-VOLHYNIAN AGRARIAN CULTURE, KSIĄŻNICE 2, POLAND. view more 

CREDIT: STANISŁAW WILK




A new DNA study has nuanced the picture of how different groups intermingled during the European Stone Age, but also how certain groups of people were actually isolated. The study was carried out by researchers at Uppsala University working with an international team of researchers, who produced new genetic data from 56 Central and Eastern European individuals from the Stone Age. The results have been published in the journal Communications Biology.

“Conducting studies like this one requires a broad interdisciplinary discussion. In this study, this discussion has been exceptionally fruitful,” says Tiina Mattila, population geneticist at Uppsala University and the study’s lead author.

Over the past 15 years, previous DNA research has pieced together a picture of the history of the European Stone Age. Before agriculture spread to Europe, there were different groups of hunter-gatherers in different parts of Eurasia, who also intermingled with each other. This study shows that the intermingling of these hunter-gatherer genetic lines was strongly linked to geography.

Several previous DNA studies of Europe’s pre-history have also shown that the spread of agriculture was strongly linked to the gene flow from Anatolia. That group was very different – genetically and culturally – from the European hunter-gatherers. But agriculture spread in different ways in different geographical areas, and this led to ethnic groups intermingling in different ways in different parts of Europe.

“These differences in the intermingling of genetic lines and cultures can tell us about the power relations between different groups,” says Tiina Mattila.
The new study also looked at close relatives.

“Common graves are often assumed to be family graves, but in our study this was not always the case. This shows that even during the Stone Age other social factors also played a role in burial practices,” says Helena Malmström, archaeogeneticist at Uppsala University.

A more comprehensive picture of the genetic history of Stone Age Europeans has emerged in recent years. And this new study adds further detail to this puzzle.

“We can show that some parts of Europe – such as the area around the Dnipro River delta – were inhabited by isolated groups of hunter-gatherers for many thousands of years, even though many other parts of Europe changed their way of life when new groups arrived who produced food by tilling the soil,” says Mattias Jakobsson, professor of genetics at Uppsala University.

An individual from Książnice 2, Poland, who lived about 6,000 years ago and was part of the new study.

CREDIT

Stanisław Wilk

 

Particulate air pollution a growing risk for premature CVD death and disability worldwide


A new study in the Journal of the American Heart Association found consistent increases yet variable differences in the rate of premature CVD death and disability due to particulate matter air pollution around the world

Peer-Reviewed Publication

AMERICAN HEART ASSOCIATION




Research Highlights:

  • Between 1990 and 2019, the total annual number of premature CVD deaths and years of disability attributable to particulate matter air pollution rose by 31% worldwide.
  • The increase in deaths was unevenly distributed by sex, with a 43% increase in deaths among men compared to a 28.2% increase among women.
  • During the nearly 30 years of data reviewed, deaths and disability attributed to outdoor particulate matter pollution rose, while deaths associated with indoor use of solid fuels declined.
  • Regions with higher socioeconomic conditions had the lowest number of years of life lost due to cardiovascular disease attributed to PM pollution, yet also the highest number of years lived with disability. The opposite was true in regions with lower socioeconomic conditions, with more lives lost and fewer years lived with disability.

Embargoed until 4 a.m. CT/5 a.m. ET Wednesday, August 9, 2023

DALLAS, August 9, 2023 — The impact of particulate matter air pollution on death and disability is on the rise worldwide, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

Previous research established the association of particulate matter (PM) pollution to CVD death and disability. However, questions remain about the worldwide impact from this type of pollution and how it has been changing over time, the study authors noted.

“We focused on examining the burden globally because particulate matter pollution is a widespread environmental risk factor that affects all populations worldwide, and understanding its impact on cardiovascular health can help guide public health interventions and policy decisions,” said Farshad Farzadfar, M.D., M.P.H., D.Sc., senior author of the study and a professor of medicine in the non-communicable diseases research center of the Endocrinology and Metabolism Research Institute at Tehran University of Medical Sciences in Iran.

The researchers analyzed PM pollution as a risk factor for death and disability using freely available data from 204 countries collected between 1990 and 2019 and detailed in the Global Burden of Disease (GBD) study. Exposure to PM pollution was estimated using a tool from the 2019 update to the GBD study that incorporated information from satellite and ground-level monitoring, computer models of chemicals in the atmosphere and land-use data.

Among the many types of heart disease, the current analysis of cardiovascular disease is restricted to stroke and ischemic heart disease (a lack of blood and oxygen supply to portions of the heart, usually due to plaque build-up in the arteries) because the 2019 GBD study on the global burden of disease attributed to PM pollution only examined these two diagnoses. The Institute for Health Metrics and Evaluation (IHME), which provides the GBD estimates, only reports data for a certain risk factor if there is a large body of evidence about its association with a disease, Farzadfar noted.

“Until now, only the association of PM pollution with ischemic heart disease and stroke has been demonstrated in a large number of studies,” Farzadfar said. “The IHME may include other CVDs in the future. Moreover, ischemic heart disease and stroke contribute to a significant majority of CVDs, and our estimates, despite having limitations, may be used as a good estimate of PM pollution burden on CVDs.”

The investigators analyzed changes over time in years of life lost due to premature death (YLLs), years lived with disability (YLDs) and disability-adjusted life years (DALYs). DALYs is a measure that considers both the loss of life and the impact on quality of life to assess the full impact of a health condition on a population. The cardiovascular disease burden was assessed both overall and with age standardization, which compares health outcomes across a population with a wide range of ages.

The analysis found:

  • The total number of premature deaths and years of cardiovascular disability from cardiovascular diseases attributable to PM air pollution rose from 2.6 million in 1990 to 3.5 million in 2019, a 31% worldwide increase.
  • The increase in overall deaths was unevenly distributed, with a 43% increase among men compared to a 28.2% increase among women.
  • Between 1990 and 2019, there was a 36.7% decrease in age-standardized premature deaths attributed to PM pollution, meaning that while fewer people had died from cardiovascular disease, people are living longer with disability.
  • Regions with higher socioeconomic conditions had the lowest number of lost years of life due to cardiovascular disease attributed to PM pollution, yet also the highest number of years lived with disability. The opposite was true in regions with lower socioeconomic conditions, with more lives lost and fewer years lived with disability.
  • Between 1990 and 2019, changes in the cardiovascular impact of PM pollution differed between men and women. In all measures, increases in disability and death from ambient PM air pollution were higher in men than women, while declines in disability and death from household PM air pollution were lower in women than men.

“The declines in deaths may be considered positive news, as they indicate improvements in health care, air pollution control measures and access to treatment. However, the increase in disability-adjusted life years suggests that although fewer people were dying from cardiovascular disease, more people were living with disability,” Farzadfar said.

The researchers also found that between 1990 and 2019, age-standardized CVD death and disability attributed to outdoor PM pollution rose by 8.1%, while age-standardized cardiovascular death and disability attributed to household PM pollution, which is produced by solid cooking fuels such as coal, charcoal, crop residue, dung and wood, fell by 65.4%.

“The reason for the decrease in the burden of household air pollution from solid fuels might be better access and use of cleaner fuels, such as refined biomass, ethanol, liquefied petroleum gas, solar and electricity. Moreover, structural changes, such as improved cookstoves and built-in stoves, chimney hoods and better ventilation, might be effective in reducing pollution exposure to solid fuels. Finally, the effects of educational and behavioral interventions should be considered,” Farzadfar said. “The shifting pattern from household air pollution due to solid fuels to outdoor, ambient PM pollution has important public policy implications.”

In a 2020 scientific statement and a 2020 policy statement, the American Heart Association details the latest science about air pollution exposure and the individual, industrial and policy measures to reduce the negative impact of poor air quality on cardiovascular health. Reducing exposure to air pollution and reversing the negative impact of poor air quality on cardiovascular health, including heart disease and stroke, is essential to reducing health inequities in Black and Hispanic communities, those that have been historically marginalized and under-resourced, and communities that have the highest levels of exposure to air pollution.

The study has several limitations. Because the assessment of exposure to particulate matter pollution in the study is based on regional estimates, it may not accurately reflect individual exposure. In addition, results from this analysis of the association between particulate matter pollution and cardiovascular outcomes may not be generalizable to other health conditions or other pollutants.

Background:

  • PM pollution consists of small particles of liquid and solids suspended in the air and inhaled into the lungs, such as vehicle emissions, smoke, dust, pollen and soot. Some particles are large enough to see (such as wildfire smoke) and may irritate the eyes, nose or throat, while others are too small to be visible but can reach deep into the lungs and even the bloodstream. Outdoor (or ambient) PM air pollution can come from vehicle emissions, industrial activities or natural sources such as pollen or dust; indoor PM often derives from heating, cooking or lighting the home with solid fuels such as coal, wood or other crop residues, especially when there is poor indoor ventilation.
  • The Global Burden of Disease (GBD) study is led by the Institute for Health Metrics and Evaluation, an independent population health research center focused on quantifying changes in population health worldwide. Data from the study can help policymakers look at hundreds of diseases, their risk factors and their impact on death and disability in various regions and throughout the world collectively.

Co-authors and authors’ disclosures are listed in the manuscript. The study authors reported no outside funding sources for this research.

Statements and conclusions of studies published in the American Heart Association’s scientific journals are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are available here.

Additional Resources:

About the American Heart Association

The American Heart Association is a relentless force for a world of longer, healthier lives. We are dedicated to ensuring equitable health in all communities. Through collaboration with numerous organizations, and powered by millions of volunteers, we fund innovative research, advocate for the public’s health and share lifesaving resources. The Dallas-based organization has been a leading source of health information for nearly a century. Connect with us on heart.orgFacebookTwitter or by calling 1-800-AHA-USA1.

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Natural gas odorants associated with consistent pattern of adverse health symptoms


Literature review examines evidence of health effects associated with several commonly used natural gas odorants

Peer-Reviewed Publication

PSE HEALTHY ENERGY




Odorants are widely used in natural gas for leak detection, however, few studies have examined their potential effects on public health. A new peer-reviewed publication in Current Environmental Health Reports, suggests that some commonly-used natural gas odorants may induce a range of adverse health symptoms at very low concentrations, ranging from headaches to respiratory inflammation and skin rashes. 

“Our sense of smell is the first line of defense in detecting gas leaks, but few studies have examined how odorants in gas may adversely affect our health or well-being,” said the review’s lead author, PSE Healthy Energy Senior Scientist Drew Michanowicz. “The studies that do exist show potential risks, including evidence of both short-term self-reported health symptoms and longer-term health complications.”

The literature review Natural Gas Odorants: A Scoping Review of Health Effects examined 22 research articles related to the health hazards, risks, and impacts of five commonly-used natural gas odorants. The researchers found that consistent symptom patterns were observed during odorant exposure in seven community-level exposure events and two occupational case reports. These findings suggest that odorants may pose health risks at much lower exposure levels than currently suspected. 

“Our findings indicate that while fairly little is known about the health risks from inhaling gas, they may be underappreciated,” said Jonathan Buonocore, Assistant Professor at the Boston University School of Public Health. “Exposure to these intentionally added odorant compounds could represent an environmental justice issue for people living with a gas leak in their home, or frequently exposed to gas at work.”

The researchers include recommendations to improve the understanding and management of natural gas odorants, such as requiring chemical disclosure of odorants used in natural gas and establishing health-based exposure limits. More research is needed to better understand the causes of symptoms associated with odorant exposure, including effects on potentially susceptible populations or those that may exhibit some forms of odorant sensitivity or insensitivity.

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About PSE Healthy Energy

PSE Healthy Energy (PSE) is a scientific research institute generating energy and climate solutions that protect public health and the environment. PSE provides expertise in public health, environmental science, and engineering and brings science to energy policy through actionable research, communications, and advising. Visit us at psehealthyenergy.org and follow us on Twitter @PhySciEng.

Ancient DNA reveals an early African origin of Cattle in the Americas


Peer-Reviewed Publication

FLORIDA MUSEUM OF NATURAL HISTORY

Image 1 

IMAGE: USING ANCIENT DNA, RESEARCHERS SHOW THAT AFRICAN CATTLE WERE LIKELY BROUGHT TO THE AMERICAS MORE THAN A CENTURY BEFORE WRITTEN RECORDS DOCUMENT THEIR ARRIVAL. view more 

CREDIT: FLORIDA MUSEUM PHOTO BY JEFF GAGE



Cattle may seem like uniquely American animals, steeped in the lore of cowboys, cattle drives and sprawling ranches. But cattle didn’t exist on the American continents prior to the arrival of the Spanish, who brought livestock with them from Europe by way of the Canary Islands.

In a new study, researchers analyzed ancient DNA from Spanish settlements in the Caribbean and Mexico. Their results indicate cattle were also imported from Africa early in the process of colonization, more than 100 years before their arrival was officially documented.

Records kept by Portuguese and Spanish colonists reference breeds from the Andalusian region of Spain but make no mention of transporting cattle from Africa. Some historians have interpreted this omission to mean that the first wave of colonists relied entirely on a small stock of European cattle initially shipped to the Caribbean Islands. 

“Early studies concluded a few hundred animals were brought over in the early 16th century, which were then bred locally on Hispaniola. From there, the initial population was inferred to have spread across the Americas,” said lead author Nicolas Delsol, a postdoctoral associate at the Florida Museum of Natural History.

During his second expedition in 1493, Columbus brought the first cattle to the Caribbean, where they were used as farm animals and a source of food. These new transplants did so well that feral livestock became a nuisance on the Island of Hispaniola. The Spanish distributed cattle widely through the Caribbean, and by 1525, foreign livestock were being farmed in parts of Central and South America. The Portuguese meanwhile moved related breeds from mainland Europe and the Cape Verde Islands to modern-day Brazil.

But researchers have reason to suspect the version of events gleaned from historical records was incomplete. In 1518, Emperor Charles V passed an edict making it legal to transport enslaved people directly from their homelands to the Americas, a practice which commenced less than three years later. In the ensuing decades, enslaved Africans would play a vital — and often unrecognized — role in the development of cattle ranching.

“The earliest ranchers in Mexico were nearly all of African ancestry,” Delsol said. “We know that people like the Fulani in West Africa formed herder societies in which they lived in what could be described as a symbiosis with cattle. Both these lines of evidence made us think there was a strong possibility that the Spanish brought cattle from the same region as the people they enslaved.”

Previous genetic studies seem to support this idea. DNA from modern American cattle bears the signature of their European ancestry, but it also reveals a history of hybridization with breeds from Africa and Asia. Without archaeological data, however, it’s not possible to pinpoint exactly when these events took place.

The first records of African cattle in the Americas date back to the 1800s, when humped zebu from Senegal and n’dama cattle from Gambia were moved to areas with similar environments across the Atlantic. Beginning at roughly the same time and continuing into the 1900s, cattle domesticated in southeast Asia for thousands of years were also imported from India. Hybridization among these cattle led to common breeds that are still around today, such as the Senepol from the Virgin Islands and the American Brahman common in the tropics.

Do these records represent the first instance of cattle imported from regions other than Europe, or are they merely the continuation of a longstanding practice that had, until then, gone undocumented?

The only way to know for sure, Delsol said, would be to sequence ancient DNA from cows and bulls preserved during the colonial era. Researchers in only one other study had attempted to do, using 16th century bones from Jamaica, but their results were inconclusive.

Delsol gathered 21 bones from several archaeological sites. Seven were excavated in Puerto Real, a former ranching town in Hispaniola established in 1503 and abandoned decades later due to rampant piracy in the region. The remaining specimens correspond to 17th and 18th century sites in Central Mexico, including settlements and convents in a long arc from Mexico City to the Yucatan Peninsula.

After extracting DNA from bone material, he compared their genetic sequences with those of modern breeds around the world. As expected, most of the sequences shared a strong relationship with cattle from Europe, which was especially true for specimens from Puerto Real. Six of the bones from Mexico also had sequences common in African cattle but, crucially, also found in breeds present in southern Europe.

“To make things difficult, there are cattle in Spain similar to those in Africa due to centuries-long exchanges across the Strait of Gibralter,” Delsol said.

But a tooth found in Mexico City stood out from the rest. Buried in the tooth’s mitochondria was a short sequence virtually unknown from anywhere other than Africa. The cow it came from likely lived in the late 1600s, pushing back the introduction of African cattle by more than a century.

When looked at over time, the bones also reveal a pattern of increasing genetic diversity. The oldest bones from Puerto Real and Xochimilco (a settlement south of Mexico City) all originated from European stock, whereas those from later sites in Mexico seem to have descended from animals more common in the Iberian Peninsula and Africa.

Taken together, the results suggest Spanish settlers began importing cattle directly from West Africa as far back as the early 1600s.

“Cattle ranching profoundly shaped the landscape and social systems across the American continents,” Delsol said. “We’ve known about the diverse genetic ancestry of American cattle for a long time, and now we have a more complete chronology for their introduction.”

The study was published in the journal Scientific Reports.

 

Ammonia as a carbon-free hydrogen carrier for fuel cells: a perspective


Peer-Reviewed Publication

INDUSTRIAL CHEMISTRY & MATERIALS

Ammonia-based power generation system 

IMAGE: THE POTENTIAL OF UTILIZING AMMONIA AS A HYDROGEN CARRIER FOR ON-SITE POWER GENERATION VIA AMMONIA DECOMPOSITION IS SYSTEMATICALLY DISCUSSED. view more 

CREDIT: ZHONGHUA XIANG, BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY, BEIJING 100029, P. R. CHINA





Due to the environmental and energy problems caused by fossil fuels, the search for alternative clean and renewable energy solutions has never been more urgent. Among these, hydrogen (H2) is emerging as a leading contender in the energy sector for both stationary and mobile applications. However, the commercial utilization of hydrogen fuel cells is hindered by the challenges of handling and transporting hydrogen due to its low volumetric energy density.

Fortunately, ammonia (NH3) is emerging as a promising hydrogen carrier due to its high hydrogen content (17.6 wt%) and potential economic benefits for energy production. When used as a fuel, it produces only nitrogen and water as byproducts, making it a carbon-free alternative to traditional fossil fuels. It can liquefy at a low pressure of 0.86 MPa at 25 ℃, providing a high volumetric energy density of 10.5 MJ L-1, which is twice that of compressed hydrogen at 70 MPa (5 MJ L-1). A team of scientists systematically discussed the potential of utilizing ammonia as a hydrogen carrier for on-site power generation via ammonia decomposition. Their work is published in Industrial Chemistry & Materials on Jun. 28, 2022.

"There has been growing interest in the utilization of ammonia as an energy vector," said Zhonghua Xiang, a Professor at Beijing University of Chemical Technology, "In this perspective, we addressed the chemical properties along with recent projects or worldwide chemical plants. Furthermore, we discussed the design strategies of catalysts and reactors, as well as their benefits and drawbacks. We hope this perspective could shed light on the potential of ammonia as a promising alternative to traditional hydrogen storage methods and highlights the challenges and opportunities that lie ahead in this exciting field of research."

As mentioned, storing renewable energy in the form of chemical fuels is deemed a pragmatic approach for both short- and long-term storage, especially in the transportation sector. In this regard, NH3 has been recommended as the more technically feasible option than CH3OH due to its advantageous chemical properties. The gravimetric H2 content of NH3 is 40% higher than CH3OH, while maintaining a comparable volumetric energy density. Additionally, for carbon-based fuels, obtaining pure carbon dioxide streams from industrial emissions may not be a viable long-term solution, and the expense for directly capturing carbon dioxide from the air is high.

"One of the primary limitations of ammonia is its apparent toxicity, which is approximately three orders of magnitude greater than that of methanol or gasoline. To ensure safe use, recommended exposure limits for NH3 are set below 100 ppm," Xiang said, "However, it is possible to monitor potential NH3 leaks and hazards in real-time using appropriate sensors. Furthermore, the human nose can detect ammonia at concentrations as low as 5 ppm in air, making it much more noticeable than odorless hydrogen. Therefore, it is practical to carry out appropriate hazard management to effectively mitigate the risk of ammonia exposure to both humans and the environment."

"The application of ammonia for power generation systems can be either stationary or portable, making it even more attractive," explained Dr. Lingling Zhai, a researcher in Xiang's group. "In China, Jiang's team from Fuzhou University developed a demonstration project that utilizes ammonia for on-site hydrogen production at a hydrogen fueling station, aiming to create a zero-carbon-emission energy community. Currently, the American technology startup company, Amogy, is launching testing operations for a 200 kW tugboat for maritime applications in cooperation with the Sustainable Energy Catapult Center in Norway. International organizations such as the Ammonia Energy Association (AEA), the International Renewable Energy Agency (IRENA), and the Oxford Institute for Energy Studies (OIES) have also made significant efforts to promote the application of ammonia as a sustainable energy commodity," Zhai said.

To apply ammonia-based power generation systems, several aspects should be considered: 1. To avoid possible leakage of ammonia, the storage tank and all connected components should use anti-corrosion materials. 2. Low-temperature (< 450 ℃) ammonia decomposition catalysts, and reactors with high volumetric energy densities are highly required. 3. Relevant policies and regulations that incentivize the adoption of renewable energy sources can help accelerate the transition to a low-carbon economy.

"With the context of the above discussions, we expect an "ammonia to hydrogen" economy may ease the scalable use of green hydrogen in the foreseeable future," Xiang said.

The research team includes Lingling Zhai and Zhonghua Xiang from Beijing University of Chemical Technology in China; and Shizhen Liu from PetroChina Company Limited.


Industrial Chemistry & Materials is a peer-reviewed interdisciplinary academic journal published by Royal Society of Chemistry (RSC) with APCs currently waived. Icm publishes significant innovative research and major technological breakthroughs in all aspects of industrial chemistry and materials, especially the important innovation of the low-carbon chemical industry, energy, and functional materials.