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.

-30-

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.

---

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.

-30-

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.

---

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.”

###

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.

---

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.

---

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

Association of Residential Racial and Economic Segregation With Cancer Mortality in the US

Lu Zhang, PhD¹; Rui Gong, PhD²; Lu Shi, PhD¹; et alMing Wen, PhD³; Xiaoqian Sun, PhD⁴; K. Robin Yabroff, PhD⁵; Xuesong Han, PhD⁵

Author Affiliations Article Information

JAMA Oncol. Published online November 17, 2022. doi:10.1001/jamaoncol.2022.5382

 Brief Report

November 17, 2022

Key Points

Question  Is residential racial and economic segregation, measured by the Index of Concentration at the Extremes, associated with cancer mortality at the county level in the US?

Findings  In this ecological study of 3110 US counties, age-adjusted mortality rates were statistically significantly higher for the most deprived counties for all cancers combined and for 12 of 13 selected cancer sites compared with the most privileged counties, with the largest magnitude occurring with lung and bronchus cancer.

Meaning  This study’s findings suggest that residential racial and economic segregation may be associated with higher cancer mortality at the county level in the US.

Abstract

Importance  Residential segregation is a structural risk factor for poor cancer outcomes. Previous research examining the association of residential segregation with cancer outcomes was limited by older data, restricted geographic areas, and few cancer sites. To guide targeted interventions, a comprehensive evaluation of the association between segregation and cancer outcomes is needed.

Objective  To examine the association of residential racial and economic segregation with cancer mortality at the US county level for all cancers combined and for the 13 cancer types that represent the top 10 causes of cancer deaths in males or females.

Design, Setting, and Participants  This ecological study used county-level sociodemographic data from the 2015-2019 American Community Survey linked with 2015-2019 county-level mortality data. Data analysis was performed from September 2021 to April 2022.

Exposures  Residential racial and economic segregation measured by the Index of Concentration at the Extremes (ICE) and categorized into quintiles 1 (most deprived) through 5 (most privileged).

Main Outcomes and Measures  Age-adjusted cancer mortality was the outcome. Multilevel linear mixed modeling was used to calculate the adjusted mortality rate ratio (aRR).

Results  A total of 3110 counties were included. The age-adjusted mortality rates of all cancers combined were 179.8, 177.3, 167.6, 159.6, and 146.1 per 100 000 population (P < .001 for trend) for the 5 ICE categories (most deprived to least deprived), respectively. Compared with the least deprived counties, aRRs for all cancers combined were 1.22 (95% CI, 1.20-1.24) for the most deprived counties, followed by 1.17 (95% CI, 1.15-1.19), 1.10 (95% CI, 1.09-1.12), and 1.06 (95% CI, 1.04-1.08) for the other 3 quintiles, respectively (P < .001 for trend). Segregation was associated with increased mortality from 12 of 13 selected cancer sites, in which aRRs ranged from 1.06 (95% CI, 1.02-1.09) for brain and other nervous system cancer to 1.49 (95% CI, 1.43-1.54) for lung and bronchus cancer.

Conclusions and Relevance  The findings of this ecological study suggest that residential racial and economic segregation is associated with higher cancer mortality at the county level, highlighting opportunities for geographically targeted cancer prevention and control efforts.

READ OR DOWNLOAD

Ray-finned fish survived mass extinction event

Peer-Reviewed Publication

UNIVERSITY OF BIRMINGHAM

 

IMAGE: PALAEONEIROS CLACKORUM SKULL AND SHOULDER GIRDLE view more 

CREDIT: MUSEUM OF COMPARATIVE ZOOLOGY, HARVARD UNIVERSITY; © PRESIDENT AND FELLOWS OF HARVARD COLLEGE

Ray-finned fish, now the most diverse group of backboned animals, were not as hard hit by a mass extinction event 360 million years ago as scientists previously thought.

The extinction event that ended the Devonian period corresponds to a major change in the kinds of fishes populating ancient seas and lakes. Ray-finned fishes, the staple of the aquarium and dinner table, were uncommon before this major crisis, and their success had been linked to new opportunities in the aftermath of the extinction.

After the extinction, in a period called the Carboniferous, the once rare ray-fins make up a sizeable percentage of fish species. These new Carboniferous fishes also show features indicating more diverse diets and styles of swimming.

A new study in Nature Ecology and Evolution, however, suggests that this shift might not have been as stark as a literal reading of the fossil record suggests. What at first seems like a sudden explosion of diversity instead appears to have had a long—but previously undetected—fuse.

In the study, the researchers investigated a tiny fossil specimen from the Late Devonian period, around 370 million years ago. The fossil, named Palaeoneiros clackorum, was found in the US state of Pennsylvania over a century ago. It had previously received little attention because of its size: at only 55 mm long it was too small to study via conventional means.

However, using CT scanning technology, the team was able to peer inside the fossil’s tiny skull and discover features that showed where Palaeoneiros fit in the family tree of fishes. To their surprise, it showed specific internal details not found in Devonian ray-fins, but instead typical of younger species from the Carboniferous.

This would mean the ray-finned fish started to diversify much earlier during the Devonian period, accumulating small but important changes to the internal structure of the head. These occurred before the outwardly obvious changes appearing during the Carboniferous including new kinds of teeth and highly specialized bodies shaped like everything from eels to angelfish.

Lead researcher Dr Sam Giles said: “These findings overturn previous assumptions about species diversification around the boundary of the Devonian and Carboniferous periods. It shows a much more complex picture in which, rather than just a handful of survivors, we can see hints of extensive diversification and survival from one period into the other.”

These results suggest that further investigation of other neglected fossils might provide more clues about how ray-finned fishes responded to the extinction at the end of the Devonian. Dr Giles and her colleagues look to apply a similar approach to other specimens they have identified, with the goal of better understanding this critical time period. “The fossil record provides us with a remarkable opportunity to see how biology responds to major environmental crises,” Dr Giles said. “And I think we’re getting closer to figuring out how—or if—this spectacularly diverse group’s rise relates to one of the most catastrophic extinctions in Earth’s history.”

Palaeoneiros clackorum skull and shoulder girdle

CREDIT

Museum of Comparative Zoology, Harvard University; © President and Fellows of Harvard College

---

JOURNAL

Nature Ecology & Evolution

DOI

10.1038/s41559-022-01919-4 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

'A Late Devonian actinopterygian suggests high lineage survivorship across the end-Devonian mass extinction

ARTICLE PUBLICATION DATE

17-Nov-2022