Friday, November 26, 2021

Mosaic brain evolution in guppies helps to explain vertebrate cognitive evolution

Peer-Reviewed Publication

STOCKHOLM UNIVERSITY

Niclas Kolm. Photo: Niklas Björling 

IMAGE: NICLAS KOLM. PHOTO: NIKLAS BJÖRLING view more 

CREDIT: NIKLAS BJÖRLING

Researchers at Stockholm University have provided the first experimental evidence that brain regions can evolve independently of each other during cognitive evolution. This so called mosaic brain evolution was verified empirically in an artificial selection experiment with guppies (Poecilia reticulata) where telencephalon size (but no other regions) differed by 10 percent after only four generations of selection. The findings can have wide implications for the understanding of cognitive evolution in other vertebrates, such as primates and humans.

The study indicates that brain evolution can occur in the form of changes in specific brain regions in a mosaic pattern, where the different parts evolve independently from each other. The researchers showed that when under strong artificial selection, the relative size of the telencephalon, or Cerebrum, changes quickly, and in an independent way. 

“The finding has large implication for our understanding of how vertebrate brains evolve, and can help us explain even human brain evolution. For instance, it is possible that cognitive demands in the environment led to gradual evolutionary changes in the size of the neocortex towards the large neocortex in humans.”, says Niclas Kolm, professor at the Department of Zoology at Stockholm University and lead principal investigator on the project.

The experiment was carried out with artificial selection experiment with guppies by Stephanie Fong, who recently defended her PhD thesis on the project. After four generations of selection on relative telencephalon volume relative to the rest of the brain, a three-year endeavor that required near 2000 aquaria and many hundreds of brain dissections by Stephanie, she found substantial changes in telencephalon size in both males and females. But no significant changes occurred in other regions, which support the mosaic brain hypothesis.

According to the mosaic brain evolution hypothesis there are selective forces, for instance cognitive demands from the environment to catch food or find mates, that affect specific areas of the brain, but when these adaptive responses occur, they do not involve other parts of the brain. Hence, different brain regions can evolve in a “mosaic” pattern, in different ways and with different rates, and thus save energy in relation to changing the entire brain.

“The study is unique because it demonstrates that targeted selection on a single region can quickly increase and decrease its size without strong correlated changes in other regions”, says Stephanie Fong.

The general layout of the vertebrate brain is remarkably conserved with regards to the different regions in the vertebrate brain. However, size variation is enormous in the different regions among species. And this size variation could have been caused by this type of mosaic brain evolution and have great general cognitive consequences.

“The study suggests that strong selection can independently change separate brain regions and thus potentially yield cost-efficient neural responses to very specific cognitive demands from the environment. The next important step, and we already have publications on the way, is to investigate the functional consequences of these fast evolutionary changes in relative telencephalon size”, says Niclas Kolm..  


CAPTION

Group of guppies

Disclaimer: AAAS and

A personalized exosuit for real-world walking


Ultrasound measurements of muscle dynamics provide customized, activity-specific assistance

Peer-Reviewed Publication

HARVARD JOHN A. PAULSON SCHOOL OF ENGINEERING AND APPLIED SCIENCES

A personalized exosuit for real-world walking 

IMAGE: RESEARCHERS FROM THE HARVARD JOHN A. PAULSON SCHOOL OF ENGINEERING AND APPLIED SCIENCES (SEAS) HAVE DEVELOPED A NEW APPROACH IN WHICH ROBOTIC EXOSUIT ASSISTANCE CAN BE CALIBRATED TO AN INDIVIDUAL AND ADAPT TO A VARIETY OF REAL-WORLD WALKING TASKS. view more 

CREDIT: BIODESIGN LAB, HARVARD JOHN A. PAULSON SCHOOL OF ENGINEERING AND APPLIED SCIENCE AT HARVARD UNIVERSITY

People rarely walk at a constant speed and a single incline. We change speed when rushing to the next appointment, catching a crosswalk signal, or going for a casual stroll in the park. Slopes change all the time too, whether we’re going for a hike or up a ramp into a building. In addition to environmental variably, how we walk is influenced by sex, height, age, and muscle strength, and sometimes by neural or muscular disorders such as stroke or Parkinson’s Disease. 

This human and task variability is a major challenge in designing wearable robotics to assist or augment walking in real-world conditions. To date, customizing wearable robotic assistance to an individual’s walking requires hours of manual or automatic tuning — a tedious task for healthy individuals and often impossible for older adults or clinical patients.

Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new approach in which robotic exosuit assistance can be calibrated to an individual and adapt to a variety of real-world walking tasks in a matter of seconds. The bioinspired system uses ultrasound measurements of muscle dynamics to develop a personalized and activity-specific assistance profile for users of the exosuit.

“Our muscle-based approach enables relatively rapid generation of individualized assistance profiles that provide real benefit to the person walking,” said Robert D. Howe, the Abbott and James Lawrence Professor of Engineering, and co-author of the paper.

The research is published in Science Robotics. 

Previous bioinspired attempts at developing individualized assistance profiles for robotic exosuits focused on the dynamic movements of the limbs of the wearer. The SEAS researchers took a different approach. The research was a collaboration between Howe’s Harvard Biorobotics Laboratory, which has extensive experience in ultrasound imaging and real-time image processing, and the Harvard Biodesign Lab, run by Conor J. Walsh, the Paul A. Maeder Professor of Engineering and Applied Sciences at SEAS, which develops soft wearable robots for augmenting and restoring human performance. 

“We used ultrasound to look under the skin and directly measured what the user’s muscles were doing during several walking tasks,” said Richard Nuckols, a Postdoctoral Research Associate at SEAS and co-first author of the paper. “Our muscles and tendons have compliance which means there is not necessarily a direct mapping between the movement of the limbs and that of the underlying muscles driving their motion.” 

The research team strapped a portable ultrasound system to the calves of participants and imaged their muscles as they performed a series of walking tasks. 

“From these pre-recorded images, we estimated the assistive force to be applied in parallel with the calf muscles to offset the additional work they need to perform during the push off phase of the walking cycle,” said Krithika Swaminathan, a graduate student at SEAS and the Graduate School of Arts and Sciences (GSAS) and co-first author of the study. 

The new system only needs a few seconds of walking, even one stride may be sufficient, to capture the muscle’s profile.   

For each of the ultrasound-generated profiles, the researchers then measured how much metabolic energy the person used during walking with and without the exosuit. The researchers found that the muscle-based assistance provided by the exosuit significantly reduced the metabolic energy of walking across a range of walking speeds and inclines. 

The exosuit also applied lower assistance force to achieve the same or improved metabolic energy benefit than previous published studies. 

“By measuring the muscle directly, we can work more intuitively with the person using the exosuit,” said Sangjun Lee, a graduate student at SEAS and GSAS and co-first author of the study. “With this approach, the exosuit isn’t overpowering the wearer, it’s working cooperatively with them.”

When tested in real-world situations, the exosuit was able to quickly adapt to changes in walking speed and incline.

Next, the research team aims to test the system making constant, real-time adjustments. 

“This approach may help support the adoption of wearable robotics in real-world, dynamic situations by enabling comfortable, tailored, and adaptive assistance,” said  Walsh, the senior author of the paper.

This research was also co-authored by Dorothy Orzel. It was supported by National Institutes of Health grants BRG-R01HD088619, U01TR002775 and R21AR076686, National Science Foundation grant CMMI-1925085.

Local exhaust ventilation to control dental aerosols and droplets


Peer-Reviewed Publication

INTERNATIONAL & AMERICAN ASSOCIATIONS FOR DENTAL RESEARCH

Alexandria, VA, USA — Dental procedures produce aerosols which contain oral microbes, creating potential for infectious disease transmission. This study, “Local Exhaust Ventilation to Control Dental Aerosols and Droplets” published in the Journal of Dental Research (JDR), investigated the effect of a Local Exhaust Ventilation (LEV) device on aerosols and droplets produced during dental procedures. These devices are designed to be placed over the patient’s mouth to capture aerosols and droplets at the source. 

Researchers at Newcastle University, England, conducted experiments on dental mannequins. Ten-minute crown preparations were performed with an air-turbine handpiece in a large open plan clinic, and full mouth ultrasonic scaling was performed for ten minutes in a single dental surgery. Fluorescein was added to instrument irrigation reservoirs as a tracer. In both settings, Optical Particle Counters (OPCs) were used to measure aerosol particles between 0.3 – 10.0 μm and liquid cyclone air samplers were used to capture aerosolised fluorescein tracer. An LEV device with High Efficiency Particulate Air (HEPA) filtration and a flow rate of 5,000 L/min was tested during the experiments. 

 

The results show that using LEV reduced the dispersion of aerosols from the air turbine handpiece by 90% within 0.5 m, and this was 99% for the ultrasonic scaler. The settling of larger droplets was also measured for the air-turbine, and this was reduced by 95% within 0.5 m when LEV was used.

 

"This study shows that the effect of LEV was substantially greater than suction alone for the air-turbine and was similar to the effect of suction for the ultrasonic scaler,” said IADR President Eric Reynolds, The University of Melbourne, Australia. “While no mitigation measure alone will completely eliminate risk, LEV appears to be a useful approach, which in addition to other measures, substantially reduces dispersion of aerosols, and therefore risk of exposure to pathogens."

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View a PDF of this press release

About the Journal of Dental Research The IADR/AADOCR Journal of Dental Research (JDR) is a multidisciplinary journal dedicated to the dissemination of new knowledge in all sciences relevant to dentistry and the oral cavity and associated structures in health and disease. The JDR 2-year Journal Impact Factor™ is 6.116, ranking #5 of 91 journals in the “Dentistry, Oral Surgery & Medicine” category, and the JDR 5-year Journal Impact Factor™ is 7.199. The JDR ranks #1 of 91 journals in total citations at 26,197 and Eigenfactor at 0.01683. The JDR Editor-in-Chief is Nicholas Jakubovics, Newcastle University, England. Follow the JDR on Twitter at @JDentRes!

International Association for Dental Research

The International Association for Dental Research (IADR) is a nonprofit organization with over 10,000 individual members worldwide, with a mission to drive dental, oral and craniofacial research for health and well-being worldwide. To learn more, visit www.iadr.org. The American Association for Dental, Oral, and Craniofacial Research (AADOCR) is the largest Division of IADR with 3,100 members in the United States. To learn more, visit www.iadr.org/aadocr

Does previous SARS experience help healthcare workers cope with COVID-19?


Over half of surveyed healthcare workers reported PTSD symptoms, whether or not they had previously worked during the SARS outbreak

Peer-Reviewed Publication

PLOS

A doctor holds a face mask and stethoscope. 

IMAGE: A DOCTOR HOLDS A FACE MASK AND STETHOSCOPE. view more 

CREDIT: ASHKAN FOROUZANI, UNSPLASH, CC0 (HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)

Previous work during the 2003 SARS outbreak has no overall impact on the psychological distress seen in healthcare workers during the COVID-19 pandemic, although it was associated with lower scores of PTSD and depression, according to a new study published this week in the open-access journal PLOS ONE by Rima Styra of University Health Network, Toronto, Canada, and colleagues.

Surveys of physicians and nurses conducted during the current COVID-19 pandemic have found significant levels of depression, anxiety, insomnia and post-traumatic distress, similar to those seen during the 2003 Severe Acute Respiratory Syndrome (SARS) outbreaks. Experience working during a prior infectious disease could either heighten or attenuate a person’s psychological response to an emerging infectious disease.

In the new study, Styra and colleagues conducted an online survey of 3,852 healthcare workers in the greater Toronto area, including 1256 nurses (34.1%), 1243 non-clinical staff (28.3%), 1034 allied health staff (28.1%) and 345 physicians (9.4%). 29.1% of respondents had also worked during the 2003 SARS outbreak. Mental health outcomes of healthcare workers were measured using three distinct scales.

More than half (50.2%) of all healthcare workers surveyed had moderate or severe scores for symptoms of post-traumatic stress disorder (PTSD), while rates of anxiety (24.6%) and depression (31.5%) were also high. Non-clinical healthcare workers were found to be at higher risk of anxiety (OR, 1.68; 95% CI, 1.19–2.15, P = .01) and depression (OR 2.03, 95% CI, 1.34–3.07, P < .001), while healthcare workers using sedatives (OR, 2.55; 95% CI, 1.61–4.03, P < .001), those who cared for only 2-5 patients with COVID-19 (OR, 1.59; 95% CI, 1.06–2.38, P = .01), and those who had been in isolation for COVID-19 (OR, 1.36; 95% CI, 0.96–1.93, P = .05) had a higher risk of PTSD. There was no statistically significant effect of previous SARS work experience on clinical or non-clinical healthcare workers’ overall psychological distress. While those who worked during the SARS outbreak experienced lower scores of PTSD (p=0.002) and depression (p<0.001), these differences disappeared after correcting for other factors such as age and career experience. The authors suggest that the data is important in guiding healthcare systems to provide appropriate, targeted and timely support to healthcare workers. 

The authors add: “Our study highlights the universal emotional distress experienced by healthcare workers, both clinical and non-clinical during the COVID-19 pandemic. It identifies that there are risk and protective factors of which we should be mindful given the wide reaching implications for staff wellness and  staff retention.”

Pet cats seem to track their owner's location - and are surprised in experiments when their voice appears to come from somewhere else

Peer-Reviewed Publication

PLOS

A cat receiving attention 

IMAGE: A CAT RECEIVING ATTENTION view more 

CREDIT: YERLIN MATU, UNSPLASH, CC0 (HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)

Pet cats seem to track their owner's location - and are surprised in experiments when their voice appears to come from somewhere else

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Article Title: Socio-spatial cognition in cats: Mentally mapping owner’s location from voice

Author Countries: Japan

Funding: This study was financially supported by the Grant-in-aid for Scientific Research (KAKENHI) No. 17J08974, No. 19J01485 to S. Takagi, Nos. 25240020, 26119514, 16H01505, 15K12047, 25118002, and 16H06301 to K. Fujita, No. 25118003 to A. Saito, No. JP16J08691 to H. Chijiiwa, and No. JP16J1034 to M. Arahori from the Japan Society for the Promotion of Science (JSPS). Anicom Speciality Medical Institute Inc. provided support in the form of salaries for author M.A, but had no role in study design, data collection or analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.

Article URL:  https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0257611

Capturing the impact of human sewage on Earth’s coastal ecosystems


New worldwide mapping analysis identifies key exposure hotspots in unprecedented resolution


Peer-Reviewed Publication

PLOS

Fig 1. Global distribution of total wastewater N. 

IMAGE: A) GLOBAL MAP OF THE TERRESTRIAL SOURCES (GREEN TO BLUE) AND COASTAL DIFFUSION OF INPUTS (YELLOW TO PURPLE) OF TOTAL WASTEWATER N, MEASURED IN LOG10(GN) IN BOTH. COASTAL PLUMES HAVE BEEN BUFFERED TO LINE SEGMENTS TO EXAGGERATE PATTERNS TO BE VISIBLE AT THE GLOBAL SCALE. INSETS SHOW ZOOMED-IN VIEWS OF THE B) GANGES, C) DANUBE, AND D) CHANG JIANG (YANGTZE) RIVERS, SHOWING WASTEWATER PLUMES AT HIGH RESOLUTION. view more 

CREDIT: TUHOLSKE ET AL., 2021, PLOS ONE, CC-BY 4.0 (HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

A first-of-its-kind, high-resolution mapping analysis estimates the amounts of nitrogen and pathogens released into coastal ecosystems from human wastewater sources around the world. Cascade Tuholske (now affiliated with the Columbia Climate School) and colleagues at the University of California, Santa Barbara, present this research in the open-access journal PLOS ONE on November 10, 2021. The researchers have created a visual representation of this, available here.

Human sewage can introduce disease-causing pathogens and nitrogen into the ocean, potentially impacting human health as well as coastal ecosystems and the communities that depend on them for such purposes as fishing. However, most research into humans’ impact on coastal ecosystems has focused on agricultural runoff, while investigations on human sewage have been limited.

To better capture the impact of sewage on coastal ecosystems, Tuholske and colleagues conducted a novel analysis in which they estimated and mapped nitrogen and pathogen inputs into the ocean from sewage for about 135,000 watersheds around the world at a resolution of 1 kilometer. The assessment employed newly available, high-resolution data on global human populations and modeled how wastewater plumes entering the ocean would overlap with different ecosystems.

The analysis suggests that wastewater from human sewage introduces 6.2 teragrams of nitrogen into coastal ecosystems per year—for comparison, that is about 40 percent of estimated inputs from agriculture. Sixty-three percent of the nitrogen is from sewage systems, 5 percent from septic systems, and 32 percent from untreated, direct input.

Of the watersheds that appear to release the most nitrogen from sewage, most are located in India, Korea, and China, with the Chang Jiang (Yangtze) River contributing 11 percent of the global total. The researchers also identified hotspots for coral reef exposure to nitrogen in China, Kenya, Haiti, India, and Yemen. Seagrass exposure hotspots were found in Ghana, Kuwait, India, Nigeria, and China. The Chang Jiang and Brahmaputra Rivers have the highest input of pathogens.

Further research will be needed to refine the model and its estimates. Nonetheless, this work provides a new resource that could play a key role in efforts to mitigate harm to ecosystems and human health—such as by highlighting locations where tradeoffs between managing nitrogen and pathogen levels are particularly important to consider.

The authors add: "The sheer scale of how much wastewater is impacting coastal ecosystems worldwide is staggering. But because we map wastewater inputs to the ocean across more than 130,000 watersheds, our results identify target priority areas to help marine conservation groups and public health officials to work together and reduce the impacts of wastewater on coastal waters across the planet."  

CAPTION

The global total wastewater input is 6.2Tg N, with 3.9Tg from sewers, 0.3Tg from septic, and 2Tg from direct input. The top 40 countries are shown in the horizontal bar chart; remaining countries are in the pinwheel, grouped by continent or larger geographical region. Values for all countries are also reported in S5 Table in S1 File. Note that the Netherlands is shown in both places (in red) to help connect the scale of the two parts of the figure.

How does homeschooling affect adolescents’ character, health and well-being?


Peer-Reviewed Publication

PLOS

A young student working from home 

IMAGE: A YOUNG STUDENT WORKING FROM HOME view more 

CREDIT: JESSICA LEWIS, UNSPLASH, CC0 (HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)

Compared to peers at public schools, adolescents who are homeschooled are more likely to report greater character strengths and fewer risky health behaviors later in life, but are less likely to attain a college degree, according to a new study published this week in the open-access journal PLOS ONE by Tyler VanderWeele of Harvard T.H. Chan School of Public Health, US, and colleagues.

School experiences are crucial for shaping individuals’ developmental and well-being trajectories later in life. Past studies have explored associations between types of primary and secondary schools and academic achievement, but outcomes beyond academic performance remain less well understood.

In the new study, researchers used data from 12,288 adolescent children of nurses enrolled in the Growing Up Today Study (GUTS).  In 1999, baseline data, including the type of school a child was attending, was collected on children between the ages of 11 and 19. Data on outcomes were collected primarily from the 2010 wave of the GUTS questionnaire, or, when missing 2010 data, from the 2013 or 2007 questionnaire .

Few statistically significant differences were seen between children who attended public schools, private independent schools and private religious schools. However when comparing students who were homeschooled with those that attended public schools, some differences emerged.  Homeschooled children were more likely to report volunteering activities (β=0.33, 95% CI 0.15-0.52, p<0.002), forgiveness of others (β=0.31, 95% CI 0.16-0.46, p<0.002) and religious service attendance (RR=1.51, 95% CI 1.27-1.80, p<0.002) but less likely to have attained a college degree (RR=0.77, 95% CI 0.67-0.88, p<0.002). They were also somewhat less likely to have used marijuana, had a lower number of lifetime sexual partners, and a greater sense of mission. The results were limited by the fact that the children were all children of nurses and were mostly non-Hispanic White; findings may not be generalizable to other populations.

The authors conclude that the study results might help inform policy-makers, educators, parents and other education stakeholders in their decisions on school policy, especially as homeschooling practices and regulations change in the wake of the COVID-19 pandemic. 

The authors add: "In a sample of adolescent children of reasonably well-educated parents, we found, on average, little difference in subsequent young adult health and wellbeing outcomes comparing those who attended public schools versus private schools. Those who were home-schooled were less likely to go on to attend college than those in public schools, but they were subsequently more likely to volunteer, to be forgiving, to have a sense of purpose, and to engage in healthier behaviors."

Uncovering racial disparities in nonfatal police shootings


Four-state study suggests disparities in police shootings might be greater than previously thought


Peer-Reviewed Publication

PLOS

Fig 2. Racial disparities in fatal and injurious police shootings in each state. 

IMAGE: POPULATION ESTIMATES FOR FL ARE 2010–14 ACS 5-YEAR ESTIMATES. POPULATION ESTIMATES FOR CO, TX, AND CA ARE 2015–19 ACS 5-YEAR ESTIMATES. view more 

CREDIT: NIX, SHJARBACK, 2021, PLOS ONE, CC-BY 4.0 (HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/)

An analysis of data from four U.S. states suggests that Black people may be more likely than white people to be nonfatally shot and injured by police in these states, and these disparities are greater than seen for fatal police shootings. Justin Nix of the University of Nebraska Omaha and John Shjarback of Rowan University in New Jersey present these findings in the open-access journal PLOS ONE on November 10, 2021.

Previous research on bias in police use of deadly force has primarily focused on police shootings that killed civilians. However, limited insights can be drawn from data that omit instances in which police shootings result in injuries but not death. Datasets which only include fatalities might be systematically biased by post-incident factors which influence mortality, such as whether police officers administer first aid or whether an adult trauma care center is nearby. However, datasets which include non-fatal shootings will count all shootings regardless of post-incident factors, making data less prone to such biases.

Most states lack publicly available data on nonfatal police shootings. To demonstrate the need for such information, Nix and Shjarback investigated potential bias using several years’ worth of data on both fatal and nonfatal police shootings from four of the few states that compile it: Florida, Texas, Colorado, and California. Statistical analysis allowed them to account for demographics and other factors that could influence shooting outcomes, such as access to a trauma center.

They found that Black civilians were more likely than white civilians to be nonfatally shot and injured in each state, and that these disparities were greater than seen for fatal shootings. For instance, from 2016 to 2019, Black people in California were 3.91 times more likely than white people to be nonfatally shot, and 3.08 times more likely to be fatally shot.

The researchers note some limitations in their study, such as lack of data on the number of rounds fired in shootings, limited information on availability of medical care, and the fact that much of the data used were reported by police. The authors underline the need for more comprehensive data in all states in order to draw reliable conclusions about racial disparities in police shootings.

The authors add: “We currently have no comprehensive national data on police firearm discharges. Our study suggests there are likely hundreds of people nonfatally injured by police gunfire each year – a disproportionate share of them Black.”

 

Extinction Rebellion targets Amazon in Black Friday protests



Activists from the Extinction Rebellion group protest outside of Amazon's headquarters in central London on Friday (AFP/Tolga Akmen)

Fri, November 26, 2021,
Activists from the Extinction Rebellion group blockaded more than a dozen distribution centres of online retail giant Amazon in Britain in what they called coordinated global Black Friday sales protests.

Dozens of demonstrators from the environmental movement -- known as XR -- blocked the company's largest UK warehouse, in Dunfermline in Scotland, as well as sites across England collectively responsible for around half of its deliveries in Britain.

The group also claimed to have targeted Amazon's distribution sites in the United States, Germany and the Netherlands, on the busiest day of the year for the retail behemoth.


The disruptive protests were "to confront the exploitative and environmentally destructive business practices of one of the world's largest companies", XR said in a statement.

Police made at least 13 arrests at three of the locations.

Five of them were at an Amazon facility in Kent, southeast England, on suspicion of aggravated trespass, while two men and two women were also arrested on suspicion of public nuisance in Manchester.

The activists blocked the entrances to the UK sites using bamboo structures and so-called lock-on devices, to form human chains, and displayed banners featuring slogans like "Amazon crime", "Infinite growth, finite planet" and "Black Friday exploits people and planet".

The activists said they arrived around 0400 GMT at the sites, which include locations in Newcastle, Manchester and Bristol as well as London, and aimed to stay for at least 48 hours.

"The action is intended to draw attention to Amazon's exploitative and environmentally destructive business practices, disregard for workers' rights in the name of company profits, as well as the wastefulness of Black Friday," an XR spokesperson said.

"The blockade is part of an international action by XR targeting 15 Amazon distribution centres in the UK, US, Germany and the Netherlands, aimed at highlighting Amazon's 'crimes'."

The protest is the latest by the activist network, formed in the UK in 2018, which regularly uses civil disobedience to highlight government inaction on climate change but has sometimes drawn a public backlash.

Eleanor Harris, from Glasgow, took part in the Dunfermline blockade.

"The era of exploitative throw-away capitalism will soon be over, either by changing to meet the challenges we now face or by the destruction of our global habitats and societies," she said.

An Amazon spokesperson said the company takes its responsibilities, including a commitment to be net-zero carbon by 2040, "very seriously".

"We know there is always more to do, and we'll continue to invent and invest on behalf of our employees, customers, small businesses and communities in the UK," they added.

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