Tick-borne pathogens increasingly widespread in Central Canada

Researchers call for more comprehensive testing to monitor disease risk of emerging tick-borne pathogens

Peer-Reviewed Publication

UNIVERSITY OF OTTAWA

 

IMAGE: LARGER CIRCLE SIZE REPRESENTS AREAS WITH GREATER TICK ABUNDANCES. CIRCLE COLOURATION DEMONSTRATES THE PROPORTIONAL RESULTS OF PATHOGEN TESTING FOR TICK POOLS. LIGHT BLUE REPRESENTS TICK POOLS THAT WERE NEGATIVE FOR PATHOGEN TESTING. PROPORTIONS OF TICK POOLS THAT WERE POSITIVE AND HARBOURING BABESIA ODOCOILEI (TURQUOISE), BORRELIA BURGDORFERI (LIGHT PURPLE), OR RICKETTSIA RICKETTSII (DARK PURPLE) ARE NOTED ON THE MAP. view more 

CREDIT: MCGILL UNIVERSITY / UNIVERSITY OF OTTAWA

Tick-borne pathogens, known for causing illnesses such as Lyme disease, are on the rise in Central Canada – presenting new risks in areas where they were never previously detected.

The findings from researchers at McGill University and the University of Ottawa demonstrate the need for more comprehensive testing and tracking to detect the spread and potential risk of tick-borne pathogens to human and wildlife populations throughout Canada.

“Most people know that diseases can be transmitted to humans through the bite of infected ticks. Ticks can carry and spread several disease agents, called pathogens, that can make people and animals sick,” explains Kirsten Crandall, a PhD candidate under the joint supervision of McGill University Professor Virginie Millien and University of Ottawa Professor Jeremy Kerr.

“While the bacteria that causes Lyme disease is the most common tick-borne pathogen in Canada, other tick-borne pathogens are moving in,” she adds.

To investigate the presence and prevalence of several emerging tick-borne pathogens, Crandall and her team analyzed small mammals and ticks collected in Ontario and Quebec. The researchers found that five emerging pathogens were present across their study sites in Central Canada, including the pathogens causing Lyme disease and babesiosis, a malaria-like parasitic disease.

They discovered that two pathogens, Babesia odocoilei and Rickettsia rickettsii, were detected outside of their historic geographic range in Quebec. These pathogens spread both babesiosis and Rocky Mountain spotted fever. “The presence of these pathogens changes the risk of disease for Canadians and animals in some densely populated areas of Canada,” says Crandall.

Transmission spread in different ways

Typically, pathogens are transmitted to a tick after feeding from the blood of an infected host, like a small mammal. However, the researchers found evidence of pathogens that could spread in other ways. Babesia odocoilei and Rickettsia rickettsii can also be directly transmitted from adult female ticks to larval ticks. Additionally, small mammals like mice can transmit the parasite Hepatozoon after ingesting an infected insect, spider, or tick.

“It’s challenging to assess the spread of certain emerging or re-emerging tick-borne pathogens, as many of them are not reported to public health agencies in Canada,” says Crandall. “Only two tick-borne pathogens are listed as nationally notifiable diseases in Canada: Lyme disease (Borrelia burgdorferi) and tularemia (Francisella tularensis). However, we are seeing increased cases of diseases like anaplasmosis and babesiosis in humans in Canada.”

Detecting the spread and potential risk

According to the researchers, the spread of emerging tick-borne pathogens has steadily increased in Canada because of climate change, habitat fragmentation, and changes in the abundance of tick populations and their hosts.

“If we don’t know that pathogens are present, we can’t equip Canadians with the information they need to protect themselves. COVID has diverted public health resources away from challenges like this one, and we need to remember that these tick-borne diseases are on the move too,” adds Jeremy Kerr, a Professor and Research Chair in University of Ottawa’s Department of Biology. 

“It’s an immense endeavour to track in real time the emergence of these pathogens across Canada, and this is when field research like ours can contribute significantly. The work of our student is a beautiful reminder that fundamental research matters, and in this case, can play a role in public health,” says Virginie Millien, an Associate Professor at the Redpath Museum at McGill University.

Pathogens detected in small mammals in Ontario and Quebec, Canada

UNIVERSITY OF OTTAWA

Larger circle size represents areas with greater small mammal abundances. Circle colouration demonstrates the proportional results of pathogen testing for individual small mammals. Light blue represents small mammals that were negative for pathogen testing. Individual small mammals that were positive and harbouring Babesia odocoilei (turquoise), Babesia microti (pink), and a Hepatozoon species (teal) are noted on the map.

CREDIT

McGill University / University of Ottawa

About the study

“Emerging Tick-Borne Pathogens in Central Canada: Recent Detections of Babesia odocoilei and Rickettsia rickettsii” by Kirsten Crandall et al. was published in Vector-Borne and Zoonotic Diseases.

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JOURNAL

Vector-Borne and Zoonotic Diseases

DOI

10.1089/vbz.2022.0036 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Emerging Tick-Borne Pathogens in Central Canada: Recent Detections of Babesia odocoilei and Rickettsia rickettsii

Shock to the system: Using electricity to find materials that can learn

Peer-Reviewed Publication

DOE/ARGONNE NATIONAL LABORATORY

Scientists used the Advanced Photon Source to watch a nonliving material mimic behavior associated with learning, paving the way for better artificial intelligence. 

Scientists looking to create a new generation of supercomputers are looking for inspiration from the most complex and energy-efficient computer ever built: the human brain.

In some of their initial forays into making brain-inspired computers, researchers are looking at different nonbiological materials whose properties could be tailored to show evidence of learning-like behaviors. These materials could form the basis for hardware that could be paired with new software algorithms to enable more potent, useful and energy-efficient artificial intelligence (AI).

In a new study led by scientists from Purdue University, researchers have exposed oxygen deficient nickel oxide to brief electrical pulses and elicited two different electrical responses that are similar to learning. The result is an all-electrically-driven system that shows these learning behaviors, said Rutgers University professor Shriram Ramanathan. (Ramanathan was a professor at Purdue University at the time of this work.) The research team used the resources of the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science user facility at DOE’s Argonne National Laboratory.

The first response, habituation, occurs when the material “gets used to” being slightly zapped. The scientists noticed that although the material’s resistance increases after an initial jolt, it soon becomes accustomed to the electric stimulus. “Habituation is like what happens when you live near an airport,” said Fanny Rodolakis, a physicist and beamline scientist at the APS. “The day you move in, you think ‘what a racket,’ but eventually you hardly notice anymore.”

The other response shown by the material, sensitization, occurs when a larger dose of electricity is administered.  “With a larger stimulus, the material’s response grows instead of diminishing over time,” Rodolakis said. “It’s akin to watching a scary movie, and then having someone say ‘boo!’ from behind a corner — you see it really jump.”

“Pretty much all living organisms demonstrate these two characteristics,” Ramanathan said. “They really are a foundational aspect of intelligence.”

These two behaviors are controlled by quantum interactions between electrons that can’t be described by classical physics, and that help to form the basis for a phase transition in the material. “An example of a phase transition is a liquid becoming a solid,” Rodolakis said. “The material we’re looking at is right on the border, and the competing interactions that are going on at the electronic level can easily be tipped one way or another by small stimuli.”

Having a system that can be completely controlled by electrical signals is essential for brain-inspired computing applications, Ramanathan said. “Being able to manipulate materials in this fashion will allow hardware to take on some of the responsibility for intelligence,” he explained. “Using quantum properties to get intelligence into hardware represents a key step towards energy-efficient computing.”

The difference between habituation and sensitization can help scientists overcome a challenge in the development of AI called the stability-plasticity dilemma. Artificial intelligence algorithms can often be, on the one hand, too reluctant to adapt to new information. But on the other, when they do they can often forget some of what they’ve already learned. By creating a material that can habituate, scientists can teach it to ignore or forget unneeded information and thus achieve additional stability, while sensitization could train it to remember and incorporate new information, enabling plasticity.

“AI often has a hard time learning and storing new information without overwriting information that has already been stored,” Rodolakis said. “Too much stability prevents AI from learning, but too much plasticity can lead to catastrophic forgetting.”

One major advantage of the new study involved the small size of the nickel oxide device. “This type of learning had previously not been done in the current generation of electronics without a large number of transistors,” Rodolakis said. “This single junction system is the smallest system to date to show these properties, which has big implications for the possible development of neuromorphic circuitry.”

To detect the atomic-scale dynamics responsible for the habituation and sensitization behaviors, Rodolakis and Argonne’s Hua Zhou used X-ray absorption spectroscopy at beamlines 29-ID-D and 33-ID-D of the APS.

A paper based on the study was published in the Steptember 19 issue of Advanced Intelligent Systems.

The research was funded by DOE’s Office of Science (Office of Basic Energy Sciences), the Army Research Office, the Air Force Office of Scientific Research and the National Science Foundation.

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JOURNAL

Advanced Intelligent Systems

DOI

10.1002/aisy.202200069 

ARTICLE TITLE

All-Electric Nonassociative Learning in Nickel Oxide

U$

Public views drone strikes with other countries’ support as most legitimate

Reports and Proceedings

CORNELL UNIVERSITY

ITHACA, N.Y. -- As the military use of aerial drones in Ukraine and other global battlefields increases, a first-of-its kind survey reveals that Americans consider tactical strikes, used with the consent of other nations, to be the most morally legitimate or appropriate.

“We know surprisingly little about the public’s perceptions of what constitutes legitimate drone strikes, despite reoccurring claims that legitimacy is central to the sustainability of drone warfare,” said Paul Lushenko, a doctoral student in the field of international relations and author of “The Moral Legitimacy of Drone Strikes: How the Public Forms Its Judgments,” published Nov. 17 in the Texas National Security Review.

To learn how those judgments are formed, Lushenko conducted an online survey of 555 Americans in March 2021.

The tactical use of a drone with multilateral constraint refers to a strike that is used in a declared theater of operations, such as Iraq and Afghanistan, with the consent of other countries.

“This type of strike represents a compromise between U.S. officials’ preference for strategic strikes with unilateral constraint – take, for example, the Biden administration’s operation that killed al-Qaeda Senior Leader Ayman al Zawahiri in Afghanistan – and the total abandonment of armed and networked drones, which characterizes Germany’s position,” said Lushenko, deputy director of the Cornell Jeb E. Brooks School of Public Policy Tech Policy Institute. Strategic strikes with unilateral constraint refer to operations where drones are used as a form of foreign policy without international oversight – essentially the U.S. policy since President George W. Bush authorized the first-known use of an armed drone in 2002.

“This finding does not mean that U.S. officials cannot, or should not, use strikes strategically to address security challenges abroad, especially terrorism,” Lushenko said. “Drones can be effective at reducing the incidence of terrorism both globally and in certain regions and countries. Rather, from a strictly moral position, this finding only suggests that it may be best for U.S. officials to refrain from using drones strategically if strikes do not have the approval and oversight of other countries.”

Lushenko is also a U.S. Army lieutenant colonel, and a Department of Government General Andrew Jackson Goodpaster Scholar. 

Survey participants were asked under what conditions they would endorse the use of military drones and Lushenko analyzed the degree to which they referenced the following considerations:

• If the strikes required a demonstration of physical courage on the battlefield by the attackers rather than being conducted from safe, remote locations.
• If the strikes protected the lives of soldiers while accomplishing military goals.
• If the strikes prevented civilian casualties that may result from other aircraft, including bombers and jets.

Lushenko said scholars often relate public attitudes toward drones to one of those three “moral norms.” But the findings empirically validated, for the first time in the scholarship about drone warfare, his hypothesis that Americans take a more complicated view. Respondents applied the norms in combination depending on their view of whether a drone strike was carried out strategically or tactically and whether it was an international effort or the U.S. going it alone.

Because U.S. counterterrorism policy relies heavily on the continued use of drones, Lushenko said policymakers need to take additional steps to build crucial public support for strikes, especially when they breach other countries’ territorial integrity.

“If U.S. officials continue to use drones strategically with unilateral constraint, which appears to be a foregone conclusion given the trajectory of U.S. drone policy across four successive presidential administrations since 2001, they should clearly explain the security benefits, the legality of the strikes, and the oversight measures that are being adopted to protect against civilian casualties,” he said.

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New monounsaturated soybean oil works well in pig diets

Peer-Reviewed Publication

UNIVERSITY OF ILLINOIS COLLEGE OF AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCE

URBANA, Ill. – Adding a fat source to the traditional corn-soy swine diet is common practice, but the type of fat can make a difference both for growing pigs and carcass quality. Polyunsaturated fats, the primary type in distillers dried grains with solubles (DDGS), can reduce fat quality and complicate processing of pork bellies and bacon.

High oleic soybeans, high in monounsaturated fats, create a stable oil valued by the food industry and nutritionists concerned with heart health. And according to new University of Illinois research supported by the United Soybean Board, high oleic soybean oil performs well as a DDGS substitute both for growing pigs and pork processing characteristics.

The research team fed growing pigs a standard corn-soybean meal finishing diet, plus DDGS or high oleic soybean oil (HOSO) as a fat source. They included DDGS at 25% and the HOSO at 2%, 4%, or 6% of the complete diet.

“When we fed the high oleic soybean oil, we saw reduced average daily feed intake, which makes some sense because as we include more energy in diets, pigs will usually consume less. The pigs were more efficient in converting that diet into pounds of gain,” says Bailey Harsh, assistant professor in the Department of Animal Sciences at Illinois and lead researcher on two new studies in the Journal of Animal Science.

In addition to growth performance, the first study focused on overall carcass characteristics.

“When we think about what is important to producers or to the standard commercial finisher, it’s how those pigs perform and yield in terms of carcass weight and fat free lean. We wanted to make sure all of that was in one study so a producer could look at that and say, well, here's the impact on my bottom line,” Harsh says.

The researchers found minimal differences in primal weights across the diets, but the overall trend showed greater fat thickness and reductions in fat-free lean as the HOSO percentage went up.

“As we added more fat to the diet, moving from 2% to 6%, the pigs grew more efficiently but were a little bit fatter and their carcass cutability dropped just a little bit, but not enough that we would be too concerned,” Harsh says.

A second study focused solely on loin and belly quality, including palatability, from the same set of pigs. Drilling down allowed the researchers to evaluate whether the diets affected the highest-value primal cuts.

“Bacon quality, as well as belly quality, is relatively dependent on a pig’s diet,” Harsh says. “If pigs are consuming a standard DDGS-containing diet which has more polyunsaturated fatty acids, those pork bellies will also be more unsaturated. We usually think about unsaturated fats as being very soft or liquid at room temperature, so you can have problems with softness of the bellies that can make them hard to slice. The loin is another primary outcome, so we needed to make sure we didn't have any major impacts on the loin either.”

Harsh says she saw very little impact on palatability, oxidation, or belly and loin quality in pigs fed HOSO compared with the DDGS diet. As expected, bellies from HOSO-fed pigs were thicker and firmer, with a higher proportion of monounsaturated fatty acids compared with DDGS-fed pigs. And loin chops were just as tender, juicy, and flavorful in the HOSO-fed pigs as pigs fed the industry standard supplement.

Although the researchers evaluated three HOSO inclusion levels in the studies, they didn’t specifically intend to make a recommendation for the swine feed industry. However, based on their results, Harsh says the 4% level looks promising.

“If we're talking about maximizing lean growth traits, the 2% is probably best because those pigs are a little bit less fat. But the 4% level probably is best for improving the thickness of bellies and making them a bit firmer, without compromising lean percentage to the same degree as the 6% level,” she says. “Looking at all the traits together, the 4% HOSO inclusion seemed to be the sweet spot.”

Although HOSO achieves good growth and meat quality characteristics, Harsh notes producers may pay a premium for the ingredient for now.

“Diet cost per pound of pig weight gain was actually a little more for HOSO than the DDGS diet. However, we really think most of that is a factor of availability,” she says. “DDGS are plentiful, so cost is lower. HOSO currently makes up a small portion of the total market, so it is more expensive. But as high oleic soybean production increases, the price for HOSO will eventually go down.”

The studies, “Effects of feeding high oleic soybean oil to growing finishing pigs on growth performance and carcass characteristics” [DOI: 10.1093/jas/skac071] and “Effects of feeding high oleic soybean oil to growing-finishing pigs on loin and belly quality” [DOI: 10.1093/jas/skac284] are published in the Journal of Animal Science. Authors for both papers are Katelyn Gaffield, Dustin Boler, Ryan Dilger, Anna Dilger, and Bailey Harsh. Funding was provided by the United Soybean Board.

The Department of Animal Sciences is in the College of Agricultural, Consumer and Environmental Sciences at the University of Illinois Urbana-Champaign.

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JOURNAL

Journal of Animal Science

DOI

10.1093/jas/skac284 

Rice refines analysis of MRI contrast agents

Engineers dig deep to detail magnetic mechanism of gadolinium-based agents

Peer-Reviewed Publication

RICE UNIVERSITY

 

IMAGE: SIMULATIONS BY RICE UNIVERSITY ENGINEERS HAVE REVEALED DETAILS ABOUT THE MOLECULAR INTERACTIONS BETWEEN GADOLINIUM CONTRAST AGENTS USED IN MRI SCANS AND THEIR LIQUID ENVIRONMENT. IN THIS MODEL, GREEN GADOLINIUM IS SURROUNDED BY BLUE CHELATE IONS, THEMSELVES SURROUNDED BY WATER (GRAY OXYGEN AND RED HYDROGEN ATOMS). view more 

CREDIT: THIAGO PINHEIRO DOS SANTOS/RICE UNIVERSITY

HOUSTON – (Nov. 17, 2022) – You can keep your best guesses. Engineers at Rice University’s George R. Brown School of Engineering are starting to understand exactly what goes on when doctors pump contrast agents into your body for an MRI scan. 

In a new study that could lead to better scans, a Rice-led team digs deeper via molecular simulations that, unlike earlier models, make absolutely no assumptions about the basic mechanisms at play when gadolinium agents are used to highlight soft tissues. 

The study led by Rice chemical and biomolecular engineer Philip Singer, former associate research professor Dilip Asthagiri, now of Oak Ridge National Laboratory, and graduate student Thiago Pinheiro dos Santos appears in Physical Chemistry Chemical Physics.

It employs the sophisticated models first developed at Rice for oil and gas studies to conclusively analyze how hydrogen nuclei at body temperatures “relax” under nuclear magnetic resonance (NMR), the technology used by magnetic resonance imaging, aka MRI.

Doctors use MRI to “see” the state of soft tissues, including the brain, in a patient by inducing magnetic moments in the hydrogen nuclei of water molecules to align with the magnetic field, a process that can be manipulated when gadolinium agents are in the vicinity. The device detects bright spots when the aligned nuclei relax back to thermal equilibrium following an excitation. The faster they relax, the brighter the contrast.

Gadolinium molecules are naturally paramagnetic and sensitive to magnetic excitation. Because they’re toxic, they are usually chelated when part of a contrast agent. “A chelate basically hugs the gadolinium and protects your body from directly interacting with the metal,” Pinheiro dos Santos said. “We’re asking, exactly how do these molecules behave?”

Though gadolinium-based contrast agents are injected by the ton into patients each year, how they work on a molecular level has never been fully understood. 

“Going back 40 years, in the NMR field people assumed liquid water is just a collection of marbles moving about, and the dipoles in the marbles randomly reorient,” Asthagiri said. 

But such assumptions are limiting, he said. “What Thiago does with his explicit simulation is show how the water network evolves in time,” Asthagiri said. “These are complicated, computationally intensive calculations.”

The Rice simulations make use of highly refined, polarizable force fields to study the phenomenon in detail, and that required intensive GPU-accelerated computing. 

The team validated its molecular dynamics approach with experimental data by co-author Steven Greenbaum, a professor of physics at Hunter College in the City University of New York, whose lab specializes in NMR measurements of ionic and molecular transport processes in condensed matter.

The simulations revealed distinct differences in how the inner and outer shells of water molecules around gadolinium respond to thermal excitation. “The inner shell is the group of eight or nine water molecules around gadolinium,” Pinheiro dos Santos said. “They’re strongly attached to the gadolinium and they stay there for a long time, a few nanoseconds. The outer shell encompasses all of the remaining water molecules.” 

The researchers found that while the structure of the inner shell does not change between 41 and 98.6 degrees Fahrenheit, its dynamics are very susceptible to thermal effects. They also discovered that temperature greatly affects the self-diffusivity of molecules in the gadolinium-water simulations in a way that affects outer-shell relaxation. 

“Overall, these discoveries open a new way to elucidate how contrast agents respond at human body conditions during an MRI scan,” Singer said. “By better understanding this, one can develop new, safer and more sensitive contrast agents, as well as use simulations to enhance the interpretation of MRI data.”

He said future studies will examine chelated gadolinium complexes in fluids that are more representative of cellular interiors. 

Co-authors of the paper are Rice alumnus Arjun Valiya Parambathu, now a postdoctoral researcher at the University of Delaware; Carla Fraenza and Casey Walsh of Hunter College; and Walter Chapman, the William W. Akers Professor of Chemical and Biomolecular Engineering at Rice. 

The Robert A. Welch Foundation (C-1241), the Ken Kennedy Institute, the Rice University Creative Ventures Fund and the Rice University Consortium on Processes in Porous Media supported the research. Research at Oak Ridge National Laboratory is supported under contract DE-AC05-00OR22725 from the U.S. Department of Energy to UT-Battelle LLC.

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Read the abstract at https://pubs.rsc.org/en/content/articlelanding/2022/cp/d2cp04390d.

This news release can be found online at https://news.rice.edu/news/2022/rice-refines-analysis-mri-contrast-agents.

Follow Rice News and Media Relations via Twitter @RiceUNews.

Video:

https://youtu.be/4WyjIXdKdPs

Video produced by Thiago Pinheiro dos Santos 

Images for download:

https://news-network.rice.edu/news/files/2022/11/1124_NMR-1-web.jpg

Simulations by Rice University engineers have revealed details about the molecular interactions between gadolinium contrast agents used in MRI scans and their liquid environment. In this model, green gadolinium is surrounded by blue chelate ions, themselves surrounded by water (gray oxygen and red hydrogen atoms). (Credit: Thiago Pinheiro dos Santos/Rice University)

https://news-network.rice.edu/news/files/2022/11/1124_NMR-2-web.jpg

Simulations by Rice University engineers revealed details about the magnetic interactions between gadolinium contrast agents used in MRI scans and their environment. From left: Philip Singer, Walter Chapman and Dilip Asthagiri. (Credit: Jeff Fitlow/Rice University)

https://news-network.rice.edu/news/files/2022/11/1124_NMR-3-web.jpg

Rice University graduate student Thiago Pinheiro dos Santos is lead author of a study that adds detail to models of gadolinium-based contrast agents used in MRI. (Credit: Rice University)

Related materials:

Modern simulations could improve MRIs: https://news2.rice.edu/2021/09/20/modern-simulations-could-improve-mris/

Chapman Research Group: https://www.ruf.rice.edu/~saft/

Chemical and Biomolecular Engineering: https://chbe.rice.edu

George R. Brown School of Engineering: https://engineering.rice.edu

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 4,240 undergraduates and 3,972 graduate students, Rice’s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 1 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger’s Personal Finance.

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JOURNAL

Physical Chemistry Chemical Physics

DOI

10.1039/D2CP04390D 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Thermal and concentration effects on 1H NMR relaxation of Gd3+-aqua using MD simulations and measurements

ARTICLE PUBLICATION DATE

8-Nov-2022

Plants use their epigenetic memories to adapt to climate change, scientists say

Peer-Reviewed Publication

CELL PRESS

Animals can adapt quickly to survive adverse environmental conditions. Evidence is mounting to show that plants can, too. A paper publishing in the journal Trends in Plant Science on November 17 details how plants are rapidly adapting to the adverse effects of climate change, and how they are passing down these adaptations to their offspring.

“One day I thought how the living style and experience of a person can affect his or her gametes transmitting molecular marks of their life into their children,” says Federico Martinelli, a plant geneticist at the University of Florence. “Immediately I thought that even more epigenetic marks must be transmitted in plants, being that plants are sessile organisms that are subjected to many more environmental stresses than animals during their life.”

Plants are facing more environmental stressors than ever. For example, climate change is making winters shorter and less severe in many locations, and plants are responding. “Many plants require a minimum period of cold in order to set up their environmental clock to define their flowering time,” says Martinelli. “As cold seasons shorten, plants have adapted to require less period of cold to delay flowering. These mechanisms allow plants to avoid flowering in periods where they have less chances to reproduce.”

Because plants don’t have neural networks, their memory is based entirely on cellular, molecular, and biochemical networks. These networks make up what the researchers term somatic memory. “These mechanisms allow plants to recognize the occurrence of a previous environmental condition and to react more promptly in presence of the same consequential condition,” says Martinelli.

These somatic memories can then be passed to the plants’ progeny via epigenetics. “We have highlighted key genes, proteins, and small oligonucleotides, which previous studies have shown play a key role in the memory of abiotic stresses such as drought, salinity, cold, heat, and heavy metals and pathogen attacks,” says Martinelli. “In this peer-reviewed opinion piece, we provide several examples that demonstrate the existence of molecular mechanisms modulating plant memory to environmental stresses and affecting the adaptation of offspring to these stresses.”

Going forward, Martinelli and his colleagues hope to understand even more about the genes that are being passed down. “We are particularly interested in decoding the epigenetic alphabet underlying all the modifications of the genetic material caused by the environment, without changes in DNA sequence,” he says. “This is especially important when we consider the rapid climate change we observe today that every living organism, including plants, needs to quickly adapt to in order to survive.”

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Trends in Plant Science, Gallusci et al.: “Deep inside the epigenetic memories of stressed plants” https://www.cell.com/trends/plant-science/fulltext/S1360-1385(22)00266-7

Trends in Plant Science (@TrendsPlantSci), published by Cell Press, is a monthly review journal that features broad coverage of basic plant science, from molecular biology to ecology. Aimed at researchers, students, and teachers, its articles are authoritative and written by both leaders in the field and rising stars. Visit http://www.cell.com/trends/plant-science. To receive Cell Press media alerts, please contact press@cell.com.

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JOURNAL

Trends in Plant Science

DOI

10.1016/j.tplants.2022.09.004 

METHOD OF RESEARCH

Commentary/editorial

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Deep inside the epigenetic memories of stressed plants

ARTICLE PUBLICATION DATE

17-Nov-2022

Social bees travel greater distances for food than their solitary counterparts, study finds

Peer-Reviewed Publication

UNIVERSITY OF BRISTOL

 

IMAGE: HONEYBEE WITH POLLEN ON SUNFLOWER view more 

CREDIT: FRANCISCA SEGERS

Social bees such as honeybees and bumblebees have larger foraging ranges, according to researchers at the University of Bristol.

The findings, published today in Current Biology, show that social bees venture further for pollen and nectar. This has implications for predicting pollination services and for creating effective conservation strategies for bees and plants.

Social bees travel bigger distances as a result of several traits which include body size, colony size, communication and flower constancy.

Larger bees like the bumblebee have greater foraging ranges. They have bigger wings and can fly faster so it's easier for them to cover more ground.

Bees from greater colonies will experience more competition from their sisters if they stay close to the nest so they need to travel further to avoid congestion.

Many social bees have evolved different kinds of communication methods. This allows foragers that have found a highly rewarding flower species to tell their sisters about their discovery. As a result, more bees will have a preference for the same kind of flowers.

Furthermore social bees tend to visit one type of flower during a foraging trip. Flower constancy means that bees ignore viable alternative options as they focus only on a subset of all available flowers, forcing them to travel further to find their favoured flower.

As bees, and especially social bees, are amongst the most important pollinators, while also being under threat, the findings have implications for their protection and the conservation of endangered plants which they pollinate.

Lead author Dr Christoph Grueter, from Bristol’s School of Biological Sciences explained: “Our findings suggest that solitary bees might be most affected by human-caused habitat loss and fragmentation because they will struggle more to find suitable food sources at greater distances.

“Social bees might be particularly important for the protection of endangered plant species that exist only in isolated patches. Since many social bee species can be kept in hives, we could use our understanding of their foraging ranges in targeted ways to aid the pollination of plants in remote areas.”

Dr Grueter and Lucy Hayes carried out the study during lockdown using coding to build a simulation model in combination with published literature to find the existing data on bee foraging ranges of 90 bee species.  They also developed an agent-based model to test how social, dietary, and environmental factors affect foraging ranges. Now he plans to study and confirm the findings in the bees’ natural environment and look at which bees are most and least affected by habitat loss and fragmentation.

He added: “Since there will be a big international push for reforestation and rewilding, this will help us understand how reforestation and rewilding projects might affect and be affected by different pollinator groups.

“Their social lifestyle means that bee colonies collect food over a much larger area than solitary bees. This helps us to plan effective conservation strategies to help both bees and the plants they pollinate.”

Paper:

‘Sociality is a key driver of foraging ranges in bees’ by Christoph Grueter and Lucy Hayes in Current Biology.

Honeybee with transponder

CREDIT

Christoph Grueter

CAPTION

Stingless bee (Melipona quadrifasciata) collecting nectar

CREDIT

Christoph Grueter

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Sociality is a key driver of foraging ranges in bees

Environment: Feeding pets dry food reduces their environmental impact

Peer-Reviewed Publication

SCIENTIFIC REPORTS

Cat and dog owners could significantly reduce the environmental impact of their pets’ diets by feeding them dry food (consisting of kibble or biscuits) rather than wet food with higher water content, suggests a study of Brazilian pets published in Scientific Reports. The findings highlight how pet owners can feed their animals more sustainably while still providing them with sufficient nutrients and calories.

The population of pet cats and dogs is growing worldwide. Currently, the USA is estimated to have 76.8 million dogs and 58.4 million cats, while Brazil has 52.2 million dogs and China has 53.1 million cats. However, the environmental impact of pet diets is unclear.

Marcio Brunetto and colleagues evaluated the environmental impacts – including greenhouse gas emissions, land use, and water usage – of 618 diets for dogs and 320 diets for cats in Brazil. The authors investigated commercial wet diets and dry diets found on the websites of three major Brazilian pet food retailers. These were also compared to homemade diets – either food produced by companies, or food cooked by owners at home using recipes provided by companies. Additionally, the authors assessed the nutritional and calorific make-up of the different diets.

For all variables, wet diets for cats and dogs had the greatest environmental impact, particularly compared to dry diets. Homemade diets tended to have intermediary environmental impacts, although water usage in homemade cat diets was similar to dry diets. The authors estimate that a ten-kilogram dog consuming on average 534 calories per day would be responsible for 828.37 kilograms of CO2 per year when fed a dry diet compared to 6,541 kilograms of CO2 per year for a wet diet – an almost seven-fold increase (689%).

Dry diets provided the highest amount of energy per gram, while wet diets and homemade diets provided higher amounts of protein. In wet diets, almost twice as much energy was provided by animal ingredients compared to dry diets (45.42% versus 89.27%), which may contribute to their greater environmental impact. 

These results highlight the extensive environmental impacts of pet foods, the need to make them more sustainable and an indication of how this may be achieved.

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-022-22631-0 

ARTICLE TITLE

Environmental impact of diets for dogs and cats

ARTICLE PUBLICATION DATE

17-Nov-2022