A breakthrough in the physics of blood clotting

New Research shows platelets do their job better when not in total sync with one another

GEORGIA INSTITUTE OF TECHNOLOGY

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IMAGE: FIRST AUTHOR YUEYI SUN INSIDE GEORGIA TECH'S COMPLEX FLUIDS MODELING AND SIMULATION LAB, WHERE SHE COMPARES THE EXPERIMENTAL AND SIMULATED PLATELET-DRIVEN FIBRIN CLOT CONTRACTION PROCESS. view more 

CREDIT: ALEXANDER ALEXEEV, GEORGIA TECH

Heart attacks and strokes -- the leading causes of death in human beings -- are fundamentally blood clots of the heart and brain. Better understanding how the blood-clotting process works and how to accelerate or slow down clotting, depending on the medical need, could save lives.

New research by the Georgia Institute of Technology and Emory University published in the journal Biomaterials sheds new light on the mechanics and physics of blood clotting through modeling the dynamics at play during a still poorly understood phase of blood clotting called clot contraction.

"Blood clotting is actually a physics-based phenomenon that must occur to stem bleeding after an injury," said Wilbur A. Lam, W. Paul Bowers Research Chair in the Department of Pediatrics and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory. "The biology is known. The biochemistry is known. But how this ultimately translates into physics is an untapped area."

And that's a problem, argues Lam and his research colleagues, since blood clotting is ultimately about "how good of a seal can the body make on this damaged blood vessel to stop bleeding, or when this goes wrong, how does the body accidentally make clots in our heart vessels or in our brain?"

How Blood Clotting Works

The workhorses to stem bleeding are platelets -- tiny 2-micrometer cells in the blood in charge of making the initial plug. The clot that forms is called fibrin, which acts as a glue scaffold that the platelets attach to and pull against. Blood clot contraction arises when these platelets interact with the fibrin scaffold. To demonstrate the contraction, researchers embedded a 3-millimeter Jell-O mold of a LEGO figure with millions of platelets and fibrin to recreate a simplified version of a blood clot.

"What we don't know is, 'How does that work?' 'What's the timing of it so all these cells work together -- do they all pull at the same time?' Those are the fundamental questions that we worked together to answer," Lam said.

Lam's lab collaborated with Georgia Tech's Complex Fluids Modeling and Simulation group headed by Alexander Alexeev, professor and Anderer Faculty Fellow in the George W. Woodruff School of Mechanical Engineering, to create a computational model of a contracting clot. The model incorporates fibrin fibers forming a three-dimensional network and distributed platelets that can extend filopodia, or the tentacle-like structures that extend from cells so they can attach to specific surfaces, to pull the nearby fibers.

Model Shows Platelets Dramatically Reducing Clot Volume

When the researchers simulated a clot where a large group of platelets was activated at the same time, the tiny cells could only reach nearby fibrins because the platelets can extend filopodia that are rather short, less than 6 micrometers. "But in a trauma, some platelets contract first. They shrink the clot so the other platelets will see more fibrins nearby, and it effectively increases the clot force," Alexeev explained. Due to the asynchronous platelet activity, the force enhancement can be as high as 70%, leading to a 90% decrease of the clot volume.

"The simulations showed that the platelets work best when they're not in total sync with each other," Lam said. "These platelets are actually pulling at different times and by doing that they're increasing the efficiency (of the clot)."

This phenomenon, dubbed by the team asynchronous mechanical amplification, is most pronounced "when we have the right concentration of the platelets corresponding to that of healthy patients," Alexeev said.

Research Could Lead to Better Ways to Treat Clotting, Bleeding Issues

The findings could open medical options for people with clotting issues, said Lam, who treats young patients with blood disorders as a pediatric hematologist in the Aflac Cancer and Blood Disorders Center at Children's Healthcare of Atlanta.

"If we know why this happens, then we have a whole new potential avenue of treatments for diseases of blood clotting," he said, emphasizing that heart attacks and strokes occur when this biophysical process goes wrong.

Lam explained that fine tuning the contraction process to make it faster or more robust could help patients who are bleeding from a car accident or, in the case of a heart attack, make the clotting less intense and slow it down.

"Understanding the physics of this clot contraction could potentially lead to new ways to treat bleeding problems and clotting problems."

Alexeev added that their research also could lead to new biomaterials such as a new type of Band-Aid that could help augment the clotting process.

First author and Georgia Tech Ph.D. candidate Yueyi Sun noted the simplicity of the model and the fact that the simulations allowed the team to understand how the platelets work together to contract the fibrin clot as they would in the body.

"When we started to include the heterogeneous activation, suddenly it gave us the correct volume contraction," she said. "Allowing the platelets to have some time delay so one can use what the previous ones did as a better starting point was really neat to see. I think our model can potentially be used to provide guidelines for designing novel active biological and synthetic materials."

Sun agreed with her research colleagues that this phenomenon might occur in other aspects of nature. For example, multiple asynchronous actuators can fold a large net more effectively to enhance packaging efficiency without the need of incorporating additional actuators.

"It theoretically could be an engineered principle," Lam said. "For a wound to shrink more, maybe we don't have the chemical reactions occur at the same time -- maybe we have different chemical reactions occur at different times. You gain better efficiency and contraction when one allows half or all of the platelets to do the work together."

Building on the research, Sun hopes to examine more closely how a single platelet force converts or is transmitted to the clot force, and how much force is needed to hold two sides of a graph together from a thickness and width standpoint. Sun also intends to include red blood cells in their model since they account for 40% of all blood and play a role in defining the clot size.

"If your red blood cells are too easily trapped in your clot, then you are more likely to have a large clot, which causes a thrombosis issue," she explained.

CAPTION

Two skin abrasions (cuts) healing thanks to blood clotting, a physics-based phenomenon that must occur to stem bleeding after an injury.

CREDIT

Georgia Tech

CITATION: Y. Sun, et.al., "Platelet heterogeneity enhances blood clot volumetric contraction: An example of asynchrono-mechanical amplification." (Biomaterials 274, 120828, 2021) https://doi.org/10.1016/j.biomaterials.2021.120828

The Georgia Institute of Technology, or Georgia Tech, is a top 10 public research university developing leaders who advance technology and improve the human condition.

The Institute offers business, computing, design, engineering, liberal arts, and sciences degrees. Its nearly 40,000 students, representing 50 states and 149 countries, study at the main campus in Atlanta, at campuses in France and China, and through distance and online learning.

As a leading technological university, Georgia Tech is an engine of economic development for Georgia, the Southeast, and the nation, conducting more than $1 billion in research annually for government, industry, and society

CAPTION

(L to R) Researchers Wilbur Lam, Alexander Alexeev, and Yueyi Sun hope their findings open medical options for people with clotting issues.

CREDIT

Reginald Tran, Georgia Tech

 

Plants get a faster start to their day than we think

UNIVERSITY OF CAMBRIDGE

Research News

 

IMAGE: A GRAPHICAL REPRESENTATION OF THE COMPLETE EARLY MORNING GENE-REGULATORY NETWORK. GENES THAT REGULATE AT LEAST ONE DOWNSTREAM TARGET ARE COLOURED DARK BLUE, WHILE OTHER GENES ARE COLOUR-CODED BY THE TIME... view more 

CREDIT: DAPHNE EZER

To describe something as slow and boring we say it's "like watching grass grow", but scientists studying the early morning activity of plants have found they make a rapid start to their day - within minutes of dawn.

Just as sunrise stimulates the dawn chorus of birds, so too does sunrise stimulate a dawn burst of activity in plants.

Early morning is an important time for plants. The arrival of light at the start of the day plays a vital role in coordinating growth processes in plants and is the major cue that keeps the inner clock of plants in rhythm with day-night cycles.

This inner circadian clock helps plants prepare for the day such as when to make the best use of sunlight, the best time to open flowers for pollinators and release pollen and when to get ready to respond to drought conditions.

There is a peak of gene activity within an hour of dawn; many of these genes code for transcription factors - proteins that regulate expression of a host of downstream genes - with roles related to light, stress and growth hormones, but the detail of how this peak is controlled is not understood.

Researchers at the Sainsbury Laboratory Cambridge University (SLCU) and University of York set out to investigate this burst of activity so as to better understand what happens at the genetic level by sampling thale cress, Arabidopsis thaliana, every two minutes from dawn to measure gene activity.

"We set out to characterise 'dawn burst' dynamics in more detail, focussing on the expression of transcription factor genes. We found three distinct gene expression waves within two hours after dawn. The first of these occurs just 16 minutes after dawn and lasts only 8 minutes." said Dr Martin Balcerowicz, researcher at SLCU and first author of the research published in Molecular Plant.

"Many of these genes are known to be sensitive to light and temperature, but we wanted to find out specifically how the transcription of these genes is coordinated. Interfering in photoreceptor signalling, the circadian clock and chloroplast derived light signals did cause problems in some genes' expression, but there was a large proportion of genes still unaffected. This indicated to us that some of the upstream pathways are redundant and that additional regulators are in play."

The team integrated their data with already published transcription factor-DNA binding data and identified a gene regulatory network at dawn, with two key regulators of light signalling - HY5 and BBX31 - at its core. These transcription factors are known to jointly control de-etiolation, which is the developmental switch a seedling undergoes when it emerges from the soil, experiencing light for the first time, and starts greening and unfolding its leaves. It appears that these genes also play a central role during the dark-to-light transition at dawn.

"In fact, multiple BBX genes form part of the dawn burst alongside BBX31, HY5 and its homologue HYH," says Dr Balcerowicz. "These genes include both positive and negative regulators of the light response. We found that they act downstream of phytochrome and cryptochrome photoreceptors to control a light-induced subset of dawn burst genes, with HY5 and BBX31 having largely antagonistic roles. This observation strengthens the idea that HY5 and BBX genes act in concert to fine-tune light responses in the context of the day-night cycle."

Dr Daphne Ezer, lecturer in Computational Biology at the University of York and senior author of the study, investigates gene-environment interactions through analysis of gene networks. "By studying gene networks we can interpret how plants integrate light and temperature signals in the early morning to entrain the circadian clock. Taken together, our results show that phytochrome and cryptochrome signalling is required for fine-tuning the dawn transcriptional response to light, but separate pathways can robustly activate much of the programme in their absence."

"Characterising the peak we see in gene expression that results from the onset of light is useful in helping us to understand how plants respond to light and, in particular, for crops grown under artificial lighting, how this dawn burst impacts longer term on growth."

CAPTION

Phytochrome and cryptochrome photoreceptors control light signalling at dawn via BBX and HY5 transcription factors: (A) Overview of the regulatory relationships between HY5 and BBX transcription factors in the early morning and (B) confirmed edges of the gene-regulatory subnetwork involving BBX31 and HY5.

CREDIT

This research was funded by an Alan Turing Institute Research fellowship under an EPSRC research grant, EPSRC/BBSRC Innovation fellowships and an EMBO fellowship.

Dawn Burst Network

View the full early morning gene network to observe patterns in the complete network and to search for a particular gene.

Dawn Burst Network website

Reference Martin Balcerowicz, Mahiar Mahjoub, Duy Nguyen, Hui Lan, Dorothee Stoeckle, Susana Conde, Katja E. Jaeger, Philip A. Wigge, Daphne Ezer (2021) An early-morning gene network controlled by phytochromes and cryptochromes regulates photomorphogenesis pathways in Arabidopsis. Molecular Plant. DOI: https://doi.org/10.1016/j.molp.2021.03.019

Darkened windows save migrating birds

New study finds decreasing lit windows could reduce bird collisions by 60%

CORNELL UNIVERSITY

Research News

ITHACA, N.Y. - Building lights are a deadly lure for the billions of birds that migrate at night, disrupting their natural navigation cues and leading to deadly collisions. But even if you can't turn out all the lights in a building, darkening even some windows at night during bird migration periods could be a major lifesaver for birds.

Research published this week in PNAS found that over the course of 21 years, one building sustained 11 times fewer nighttime bird collisions during spring migration and 6 times fewer collisions during fall migration when only half of the building's windows were illuminated, compared to when all windows were lit.

In the study, the factors that had the strongest effect on bird collisions were the intensity of the migration (more birds migrating = more collisions), the wind direction (westerly winds = more collisions), and area of illuminated windows (more surface area lit = more collisions).

The authors also calculated that if half of the building's windows had been darkened during peak migration periods, bird kills would have been reduced by around 60% over the past two decades.

The sheer strength of the link between lighting and collisions was surprising," says Benjamin Van Doren, a postdoctoral researcher at the Cornell Lab of Ornithology and lead author of the research. "It speaks to the exciting potential to save birds simply by reducing light pollution."

To reach their conclusions, researchers from the Cornell Lab, the University of Michigan, and the Field Museum in Chicago, Colorado State University, and the University of Massachusetts Amherst examined bird data from McCormick Place, a 3-story convention center in the eastern section of Chicago, over 21 years (2000-2020).

At the heart of the study were the records of over 40,000 dead birds--including when they were killed, which window, and what species--collected at the convention center since 1978.

Since 2000, these records have also included information about which windows bays were illuminated when each bird kill happened. By comparing this data from McCormick Place with other potential collision-risk factors such as weather conditions, moonlight, and migration intensity, researchers teased apart which conditions were deadliest for migrating birds.

Building strikes kill hundreds of millions of birds a year, and many of these occur at night and during the migration seasons, when hundreds of species of songbirds are moving across the hemisphere under the cover of darkness.

In response, a growing number of "lights out" initiatives and green building guidelines call for reductions in lighting to aid migrating birds. Lights Out Chicago is among the oldest of over 40 initiatives across North America and brings together building managers, local conservation organizations, city staff, and scientists at the Field Museum. The results of the study strengthen the science behind lights out programs by showing that darkening windows can directly reduce bird mortality.

The researchers also aim to engage people in lights-out efforts with local migration alerts, which give advance warning of nights with large bird migration events. "Although permanently reducing light pollution is the ultimate goal, we hope to raise awareness through BirdCast migration forecasts. Our forecasts predict the nights when large numbers of migrating birds will be at risk and turning off lights is critically important," says Van Doren.

Previous studies have shown that lights from city buildings, installations and events can attract and disorient migrating birds, shifting migration routes toward urban areas. And a 2018 study showed Chicago is the highest-ranked U.S. city for light pollution exposure risk to night-migrating birds; as many as 100 million birds pass through the greater Chicago area in the spring, and over 150 million in the fall.

Ben Winger, an assistant professor and curator at the University of Michigan and a senior author on the research, says one of the powerful things about this study is that it confirms a number of phenomena that have been observed, but not previously quantified. "We identified specific weather conditions during which collisions happen more frequently," says Winger, "but the importance of illumination from the building emerged as a very important part of the story."

The study also speaks to the importance of natural history collections in documenting global change. "These collision data are even more valuable because they are backed up by specimens that are available for study in the Field Museum," Winger says. "This will allow future scientists to go a step further in connecting different aspects of avian biology to the hundreds of millions of birds killed each year by window strikes."

Dave Willard, now collections manager emeritus at the Field Museum, started collecting dead birds around McCormick Place in 1978, and hopes that having a data-driven analysis of the hazards of nocturnal lighting can help inform positive change in the ways cities build and the ways buildings use their lights at night. "This paper brings together weather, radar and bird-collision data and shows unequivocally that reduced building lighting at night can substantially reduce bird fatalities."

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Mandating vaccination could reduce voluntary compliance

SANTA FE INSTITUTE

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IMAGE: KATRIN SCHMELZ view more 

CREDIT: UNIVERSITY OF KONSTANZ

Citizen opposition to COVID-19 vaccination has emerged across the globe, prompting pushes for mandatory vaccination policies.  But a new study based on evidence from Germany and on a model of the dynamic nature of people's resistance to COVID-19 vaccination sounds an alarm: mandating vaccination could have a substantial negative impact on voluntary compliance.

Majorities in many countries now favor mandatory vaccination. In March, the government of Galicia in Spain made vaccinations mandatory for adults, subjecting violators to substantial fines. Italy has made vaccinations mandatory for care workers. The University of California and California State University systems announced in late April that vaccination would be required for anyone attending in the Fall.

The research, published in this week's Proceedings of the National Academy of Sciences (PNAS), extends an earlier PNAS study by first author Katrin Schmelz, a psychologist and behavioral economist at the University of Konstanz, documenting that a major source of vaccine hesitancy is distrust of government. She found that enforced vaccinations reduce people's desire to be vaccinated, particularly among those with low levels of trust in public institutions.

In the new study, Schmelz and economist Samuel Bowles of the Santa Fe Institute exploit a large panel survey implemented in Germany during the first and second waves of the pandemic. Despite infections in Germany being 15 times more common in the second wave of both the pandemic and the survey, the researchers observed increased opposition when they asked participants a hypothetical question about how they'd respond if vaccinations were to be legally required (the German government is publicly committed not to require vaccinations). In contrast, there was a higher and undiminished level of support for the voluntary vaccinations now in force. 

The authors also draw on evidence from the dynamics of diffusion of novel products and technologies such as TVs and washing machines in the last century. They reason that as those who are hesitant or opposed to vaccination see that others are getting vaccinated, they might change their mind. Learning from others' vaccination decisions - "conformism" in psychology - means that even if initial vaccination hesitancy is substantial, as more become vaccinated it may be possible to get to a herd immunity target without mandating vaccines.

They also use experimental evidence from behavioral economics showing that explicit incentives, whether in the form of carrots or sticks, may crowd out intrinsic or ethical motives. Policies that aim to incentivize a desired behavior, such as getting vaccinated, can actually undercut individuals' sense of a moral or ethical obligation to do the right thing. 

This is evident in their data. Mandating vaccinations by law directly reduces the desire to be vaccinated. Their model also suggests an adverse indirect effect: enforcement will reduce the extent to which others being vaccinated will induce vaccine hesitators to become willing, as this carries a weaker signal. Schmelz says "How people feel about getting vaccinated will be affected by enforcement in two ways -- it could crowd out pro-vaccine feelings, and reduce the positive effect of conformism if vaccination is voluntary."

Bowles says this should be a caution to governments considering mandated policies: "Costly errors may be avoided if policymakers reflect carefully on the costs of enforcement. These could not only increase opposition to vaccination, but also heighten social conflict by further alienating citizens from the government or scientific and medical elites," he says. Nonetheless, he says government enforcement "may still be necessary if the number wishing to be vaccinated is insufficient to control the pandemic."

Schmelz concludes that "Our findings have broad policy applicability beyond COVID-19. There are many cases in which voluntary citizen compliance to a policy is essential because state enforcement capacities are limited, and because results may depend on the ways that the policies themselves alter citizens' beliefs and preferences," adding that "... examples include policies to promote lifestyle changes to reduce carbon footprints or to sustain tolerance and mutual respect in a heterogeneous society."

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Correcting misperceptions about, and increasing empathy for, migrants

Americans dramatically overestimate the number of migrants affiliated with gangs and children being trafficked

UNIVERSITY OF PENNSYLVANIA

Research News

 

Many mainstream depictions of immigration at the southern border of the United States paint a dark picture, eliciting imagery of violent gang members and child trafficking. But how many undocumented immigrants are really involved in this kind of activity? Many people may be surprised to learn the answer is far fewer than they think.

A new study from the Peace and Conflict Neuroscience Lab (PCNL) at the Annenberg School for Communication found that Americans dramatically overestimate the number of migrants affiliated with gangs and children being trafficked, and that this overestimation contributes to dehumanization of migrants, lack of empathy for their suffering, and individuals' views on immigration policy. In addition, the researchers developed and tested interventions to address this misinformation and increase empathy for undocumented immigrants.

"We noticed that false narratives about undocumented immigrants as criminals or as having criminal intentions are commonly circulated in the public," says Samantha Moore-Berg, a PCNL postdoctoral fellow and lead author of the study. "We were curious about the impact of these narratives on attitudes toward immigrants and immigration policy support, and whether by correcting these narratives, we are able to foster more positive attitudes toward immigrants."

The study aimed to compile data on Americans' (mis)perceptions of immigrants' motivations for crossing the southern border, determine whether those (mis)perceptions affected Americans' policy positions, and develop successful interventions for addressing (mis)perceptions and increasing empathy.

Study participants, on average, estimated that 15% of migrants at the southern border are affiliated with gangs and 25 to 35% of children at the southern border are being used as props by adults who are not their parents for immigration purposes. In reality, the Department of Homeland Security suspects approximately 1% of immigrants have gang connections and fewer than 0.1% of children are being trafficked.

The researchers found that participants' erroneous beliefs about immigrants affected their views on immigration policy and caused them to view immigrants with less empathy and to dehumanize them more. However, after a successful intervention, which included viewing the correct statistics on immigrant behavior and watching an emotional video of an immigrant parent and child being reunited after the U.S. separated them at the border, participants' levels of empathy for immigrants increased, their dehumanization of immigrants decreased, and their support of less punitive immigration policy increased.

"By both correcting these false narratives about immigrants and unlocking empathy toward them, we were able to foster more positive attitudes toward immigrants and encourage greater support for more humane immigration policies" Moore-Berg says. "This gives us hope that by shifting narratives about immigrants to be both more accurate and empathetic, we can ultimately foster greater acceptance of immigrants."

"Empathy, Dehumanization, and Misperceptions: A Media Intervention Humanizes Migrants and Increases Empathy for Their Plight, but Only If Misinformation about Migrants Is Also Corrected," was published today in Social Psychological and Personality Science. In addition to Moore-Berg, authors include Boaz Hameiri (Tel Aviv University) and the late Emile Bruneau.

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A new disease called halo blight threatens Michigan hop production

AMERICAN PHYTOPATHOLOGICAL SOCIETY

Research News

IMAGE: SIGNS AND SYMPTOMS OF A DIAPORTHE SP. 1-MI ON HOP CONES view more 

CREDIT: DOUGLAS S. HIGGINS, ROSS J. HATLEN, JAN M. BYRNE, MONIQUE L. SAKALIDIS, TIMOTHY D. MILES, AND MARY K. HAUSBECK

If you're a beer drinker, you've noticed that hoppy beers have become increasingly popular. Most of the nation's hops come from the Pacific Northwest. However, commercial hop production regions have expanded significantly. In Michigan hop production nearly tripled between 2014 and 2017 and in 2019, Michigan growers harvested around 720 acres of hops.

Michigan hop growers contend with unique challenges as a result of frequent rainfall and high humidity during the growing season. In 2018, growers approached Michigan State University researchers and the Michigan State University's Plant & Pest Diagnostics lab with concerns about a leaf blight they had never seen before. This was followed by reports of hop cones shattering during harvest and yield losses in fields with the affected leaves.

Michigan State University scientists, including Doug Higgins, investigated, observing a fungus growing in the symptomatic leaves. They set out to determine if the fungus was causing the symptoms and if the leaf and cone symptoms were linked to the same pathogen. They also wanted to determine how far the disease had spread in Michigan.

They determined that the fungus was the same on both the leaves and the cones. "The fungus was shown to infect and cause disease in healthy hop plants," said Doug Higgins. "Interestingly, genetic testing showed that DNA from the fungal pathogen did not match DNA from other known fungal species. We concluded that it is novel species and for now called it Diaporthe sp. 1-MI."

As this novel fungal pathogen causes yellow margins to form around leaf lesions and the browning of cones, Higgins and colleagues named the disease "halo blight." Their surveys indicated that halo blight is widespread in Michigan, and that other production regions with similar climatic conditions might also be at risk.

"In Michigan, hop is a niche crop used by many local breweries. A disease outbreak could impact the supply of local hops to many small and independent businesses," explained Higgins. "Additionally, cone discoloration can alter hop quality and may have downstream implications on beer quality." Higgins recommends that additional research be conducted to understand how the disease moves and develop management strategies.

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For more information about halo blight and this research, read "Etiology of Halo Blight in Michigan Hopyards" published in the April issue of Plant Disease.

 

African great apes to suffer massive range loss in next 30 years

WILDLIFE CONSERVATION SOCIETY

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IMAGE: A NEW STUDY PUBLISHED PREDICTS MASIVE DECLINES FOR CHIMPANZEES AND OTHER AFRICAN GREAT APES DUE TO THE IMPACTS OF CLIMATE CHANGE, LAND-USE CHANGES AND HUMAN POPULATION GROWTH. view more 

CREDIT: EMMA STOKES/WCS

A new study published in the journal Diversity and Distributions predicts massive range declines of Africa's great apes - gorillas, chimpanzees and bonobos - due to the impacts of climate change, land-use changes and human population growth.

For their analysis, the authors compiled information on African ape occurrence held in the IUCN SSC A.P.E.S. database, a repository that includes a remarkable amount of information on population status, threats and conservation for several hundred sites, collected over 20 years.

The first-of-its-kind study quantifies the joint effects of climate, land-use, and human population changes across African ape ranges for the year 2050 under best- and worst-case scenarios. "Best case" implies slowly declining carbon emissions and that appropriate mitigation measures will be put in place. "Worst case" assumes that emissions continue to increase unchecked - business as usual.

Under the best-case scenario, the authors predict that great apes will lose 85 percent of their range, of which 50 percent will be outside national parks and other areas protected by legislation. Under the worst-case scenario, they predict a 94 percent loss, of which 61 percent will be in areas that are not protected.

This paper examines whether great apes can or cannot disperse away from where they are currently found, and the best- and worst-case scenarios in each case. For example, mountains are currently less suitable than lowland areas for some great ape species. However, climate change will render some lowlands less suitable - warmer, drier, perhaps less food available - but the nearby mountains will take on the characteristics that those lowlands currently have. If great apes are able to physically move from the lowlands to the mountains, they may be able to survive, and even increase their range (depending on the species, and whether it is the best- or worst-case scenario). However, they may not be able to travel (disperse) away from the lowlands in the time remaining between today and 2050.

Joana Carvalho, postdoctoral researcher in the Faculty of Science, Liverpool John Moores University, lead author of the study says: "By integrating future climate and land-use changes as well as human population scenarios, this study provides strong evidence for synergistic interactions among key global drivers constraining African ape distribution."

Carvalho adds: "Importantly, massive range loss is widely expected outside protected areas, which reflects the insufficiency of the current network of protected areas in Africa to preserve suitable habitats for great apes and effectively connect great ape populations."

Fiona Maisels of the Wildlife Conservation Society (WCS), and a co-author of the study, said: "As climate change forces the different types of vegetation to essentially shift uphill, it means that all animals - not only great apes - that depend on particular habitat types will be forced to move uphill along with the vegetation, or become locally extinct. And when the hills are low, many species, great and small, will not be able go higher than the land allows, and huge numbers of animals and plants will simply vanish."

The authors argue that effective conservation strategies require careful planning for each species that focuses on both existing and proposed protected areas - the creation and management of which can be informed by these habitat suitability models. Additionally, efforts to maintain connectivity between the habitats predicted to be suitable in the future will be crucial for the survival of African apes. Conservation planners urgently need to integrate land-use planning and climate change mitigation and adaptation measures into government policy of great ape range countries.

The study highlights the need for urgent action to combat both biodiversity loss and climate change if great apes are to continue into the future. Governments must protect and conserve the habitats of great apes--where they are now, and where they will need to move. Governments attending the upcoming Convention on Biological Diversity CoP 15 in September and the UN Climate Change Conference in November should adopt meaningful commitments to protect and conserve great apes and their habitats and combat climate change.

The results of the study corroborate other recent studies showing that African ape populations and their habitats are declining dramatically. All African great apes are classified either as Endangered (mountain gorillas, bonobos, Nigeria-Cameroon chimpanzees, eastern chimpanzees, and central chimpanzees) or Critically Endangered (Cross River gorillas, Grauer's gorillas, western lowland gorillas, and western chimpanzees) on the IUCN Red List of Threatened Species, and all are regarded as flagship species for conservation.

Hjalmar Kuehl, from iDiv in Leipzig, Germany, and senior author of the study said: "There must be global responsibility for stopping the decline of great apes. Global consumption of natural resources extracted from ape range countries is a major driver of great ape decline. All nations benefitting from these resources have a responsibility to ensure a better future for great apes, their habitats and the people living therein by developing more sustainable economies."

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The study involved over 60 co-authors from academic and non-academic organizations and government agencies, including Antwerp Zoo Society, Born Free Foundation, Chimbo Foundation, Conservation Society of Sierra Leone, Environment and Rural Development Foundation, Fauna & Flora International, Frankfurt Zoological Society, Jane Goodall Institute, Rio Tinto, Royal Society for the Protection of Birds, San Diego Zoo Wildlife Alliance, Sekakoh Organisation, Sierra Rutile Limited, Tacugama Chimpanzee Sanctuary, The Biodiversity Consultancy, West African Primate Conservation Action, Wild Chimpanzee Foundation, Wildlife Conservation Society (WCS), and World Wide Fund for Nature.

 

High blood lead levels found in indigenous peoples in Peruvian Amazonia

The study finds higher concentrations of lead in communities living where oil extraction has been most intense

UNIVERSITAT OBERTA DE CATALUNYA (UOC)

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IMAGE: OIL SPILL FROM SAN JACINTO FACILITY, DOCE DE OCTUBRE INDIGENOUS COMMUNITY IN THE TIGRE RIVER BASIN, LORETO, PERU. view more 

CREDIT: (PHOTO: JEAN PIERRE, OPIKAFPE)

Lead is a toxic metal, and its widespread use has led to significant environmental pollution and public health problems in many parts of the world. This has led the WHO to include it on a list of ten chemicals that cause serious health problems. However, lead poisoning continues to affect many population groups. A study published today in open access in the journal Environment International found high levels of lead in indigenous people in Peruvian Amazonia living near areas where oil extraction takes place. The research was led by Cristina O'Callaghan-Gordo, a professor and researcher in Health Sciences Studies at the Universitat Oberta de Catalunya (UOC) and the Barcelona Institute for Global Health (ISGlobal), a centre supported by the "la Caixa" Foundation and the National Institute of Health of Peru.

"The main hypothesis is that the metal reaches them through their diet in areas with the most serious environmental pollution, as the population hunts and fishes for food, and previous studies have shown the that lead is present in animals in this region. On the other hand, in places with lower levels of environmental pollution, the most likely route is occupational exposure, such as coming into direct contact with oil due to participating in clean-up tasks after oil spills," explained Cristina O'Callaghan-Gordo.

The closer and more intense the extraction, the higher the levels of lead

The study included 1,047 people, of whom 309 (31%) were children under 12 years old. The population studied lives in four river basins in Peruvian Amazonia, a remote non-industrialized region.

The work took place between May and June 2016, and involved face-to-face interviews to collect data on the participants' risk factors and lifestyle, as well as blood tests. The research also took the distance between where the population lived and the oil extraction facility into account. The highest blood lead levels were found among participants from the Corrientes river basin, which accounts for most of the oil extraction activity in the region.

The study also found higher levels of lead in the blood of people living less than an hour's walk from an oil facility. The values observed in this study are twice as high as the values reported for children in Europe between 1999 and 2007, at a time when leaded petrol was still used in Europe (which in some countries continued until 2005).

The results showed high levels of lead, especially among males. "This is quite common, as men tend to be involved more often in activities that expose them to lead, such as cleaning up spills," said O'Callaghan-Gordo.

Health problems

This study is the result of an agreement reached between the indigenous peoples' federations in the river basins affected and the Peruvian Government, aimed at addressing their concerns about the potential effects on health. "This study came about at the request of the indigenous communities, as they have been calling upon the Government to do something in this respect for decades," said the researcher.

Alterations in the nervous, haematological, gastrointestinal, cardiovascular and renal systems are associated with exposure to lead in both adults and children, according to the United Nations Environment Programme.

"Levels of lead like those we found in Peru have effects on health. In fact, any amount of this metal in the blood has consequences for health. The most well-known known effects are neurological and neurodevelopmental problems in children," warned Cristina O'Callaghan-Gordo.

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The study received funds from the National Institute of Health of Peru and count with the collaboration of the indigenous federations FEDIQUEP, ACODECOSPAT, FECONACOR and OPIKAFPE, which are part of the Amazonian Indigenous Peoples United in Defence of their Territories (PUINAMUDT). The research has also been carried out in collaboration with Centro de Políticas Públicas y Derechos Humanos in Peru, the University of Cambridge, Universitat Central de Catalunya-Universitat de Vic, Institut de Ciència i Tecnologia Ambientals from the Universitat Autònoma de Barcelona and the e-Tech International from the USA.

This research contributes to achieving sustainable development goal (SDG) number 3, "To ensure healthy lives and promote well-being for all at all ages".

Reference article:

Cristina O'Callaghan-Gordo, Jaime Rosales, Pilar Lizárraga, Frederica Barclay, Tami Okamoto, Diana M. Papoulias, Ana Espinosa, Martí Orta-Martinez, Manolis Kogevinas, John Astete, "Blood lead levels in indigenous peoples living close to oil extraction areas in the Peruvian Amazon" (2021) Environmental Research, https://doi.org/10.1016/j.envint.2021.106639

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