Microbial awakening restructures high-latitude food webs as permafrost thaws

New study shows that fungi are replacing plants as primary energy source for Arctic and boreal animals

Peer-Reviewed Publication

USDA FOREST SERVICE - PACIFIC NORTHWEST RESEARCH STATION

 

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AN AERIAL VIEW OF DECAYING PERMAFROST IN ALASKA’S BONANZA CREEK EXPERIMENTAL FOREST.

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CREDIT: USDA FOREST SERVICE

Alaska is on the front lines of climate change, experiencing some of the fastest rates of warming of any place in the world. And when temperatures rise in the state’s interior—a vast high-latitude region spanning 113 million acres—permafrost there not only thaws, releasing significant amounts of its stored carbon back into the atmosphere where it further accelerates rising temperatures, but it decays. This decomposition has the potential to infuse above- and belowground food webs with carbon, which can affect energy flow between these critical ecological linkages and affect the species they support.

One of these species is the tundra vole, one of four Arctic or boreal forest animals that Philip Manlick, a research wildlife biologist with the USDA Forest Service Pacific Northwest Research Station in Juneau, Alaska, examined as part of his new study published today in the journal Nature Climate Change. Along with collaborators from the University of New Mexico and the University of Texas at Austin, Manlick used a novel technique to quantify the impacts of climate change on energy flow and carbon fluxes between plant-supported aboveground, or green, food webs and microbe-driven belowground, or brown, food webs using two species of vole, a shrew, and a spider as windows into the complex worlds.

“Understanding how energy moves through food webs helps us understand how ecosystems function and how animals might respond to stressors like climate change,” Manlick said. “In Arctic and boreal ecosystems, it’s well known that the climate is warming, permafrost is melting, and microbes are flourishing. But we know very little about the impacts of this process on terrestrial food webs and the animals they support.” 

A Novel Technique With Promise

The novel technique at the heart of the study involved measuring unique carbon isotope “fingerprints” in essential amino acids that only plants, bacteria, and fungi can produce. Animals can only acquire these molecules through their diets. This allowed these essential amino acids to serve as a biomarker that helped the researchers track how carbon was moving between green and brown food webs, which, ultimately, helped them detect changes.

“Scientists often argue about the importance of animals to ecosystem processes like carbon cycling, but when they eat resources from different food webs, they move carbon between storage pools,” Manlick said. “In the future, we think this tool can be used to trace the fate of carbon through food webs to understand the functional roles of animals in ecosystem functions, like nutrient cycling.”

The study analyzed bone collagen from museum specimens of tundra and red-backed voles and masked shrews from the Bonanza Creek Experimental Forest near Fairbanks, Alaska, in 1990 and 2021, a sample that represented animals exposed to long-term climate warming. To study the effects of short-term climate warming on animals, the researchers sampled Arctic wolf spiders near Toolik Lake, Alaska. Some of the spiders were gathered as controls and others were exposed to 2 °C warming in outdoor compartmentalized habitats called “mesocosms” in which the scientists could increase temperature on a micro scale to simulate climate warming.

At just over 12,000 acres, and encompassing interior forest and flood-plain habitats, Bonanza Creek Experimental Forest is an ideal site for studying the impacts of climate change on boreal forests and food webs because it provides a long-term record of change in interior Alaska. It was established by the USDA Forest Service 60 years ago and has been a National Science Foundation Long-term Ecological Research site since 1987. For Manlick, the site offers an opportunity to study how these boreal forest changes are affecting the animals living there and how the animals, themselves, affect forest processes through foraging and food web dynamics.

Significant Shift in Energy Source

Through their isotope analyses, Manlick and his colleagues detected significant changes in carbon assimilation in the mammals—notably a shift from plant-based food webs to fungal-based food webs. In other words, fungi replaced plants as the main energy source—with small mammals, like the shrews, assimilating up to 90 percent of their total carbon intake from fungal carbon, a more than 40-percent increase over historical specimens.

The same was true for the Arctic wolf spiders. They, too, shifted from plant-based to fungal-based food webs as the main source of their energy, assimilating more than 50 percent brown carbon under warming conditions, compared to 26 percent at control sites.

“Our study presents clear evidence that climate warming alters carbon flow and food web dynamics among aboveground consumers in Arctic tundra and boreal forest ecosystems—across species, ecosystems, and long- and short-term warming scenarios,” Manlick said. “And we show that these changes are the consequence of a change from predominantly green, plant-based food webs to brown, microbe-based food webs.”

What’s behind the shift?

The scientists suspect brown carbon is being transferred to aboveground consumers, like the mammals and spiders, in a series of predation events known as trophic pathways. Increased warming results in increased decomposition in both permafrost on the tundra and in boreal forests; fungi feed on this decomposing plant matter and are, in turn, consumed by arthropods, mites, and earthworms that transfer the fungal carbon upward in the food web where they, in turn, are consumed by the voles, shrews, and spiders.

“Climate warming significantly alters the flow of energy through food webs, such that animals who were historically supported by plant-based food webs are now supported by fungal-based food webs derived from belowground decomposition,” Manlick said.

A typical black spruce bog in Alaska’s Bonanza Creek Experimental Forest.

CREDIT

USDA Forest Service

Animals Can Alter Carbon Cycling

Manlick and his colleagues’ work underscores that animals serve as a crucial link between green and brown food webs; it also shows that climate warming alters this link across species in the Arctic and in boreal forests. The potential implications of these climate-induced shifts are greater than the small size of these species might imply. 

“Shifts in these interactions can have indirect effects on nutrient cycling and ecosystem function,” Manlick said.

For example, if voles are getting more of their energy from belowground sources, they may be consuming fewer plants, which could increase carbon storage in aboveground ecosystems.

“Much of the current work in high latitudes has focused on ‘Arctic greening,’ or the idea that climate warming is leading to more plant growth and greener ecosystems. We found the exact opposite pattern—food webs are ‘browning,’” he said.

Moving forward, Manlick plans to study why these patterns in plants and animals differ and what it means for the future of these rapidly changing ecosystems.

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JOURNAL

Nature Climate Change

DOI

10.1038/s41558-023-01893-0 

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Climate warming restructures food webs and carbon flow in high-latitude ecosystems

ARTICLE PUBLICATION DATE

3-Jan-2024

 

Women from low socio-economic backgrounds see themselves as less talented

How distorted self-images carry a negative impact on chances of success

Peer-Reviewed Publication

UNIVERSITY OF VIENNA

Women from low socio-economic backgrounds consider themselves to be less talented than all other groups – even if they show the same performance levels. This is shown by a new study led by Christina Bauer at the University of Vienna. This misconception contributes to the pronounced disadvantage in domains such as STEM subjects, where talent is seen as an important success factor. Social psychologist Christina Bauer has now published these key findings from her latest research in the current issue of the renowned journal Learning and Instruction – and suggests possible solutions to this problem.

Women and people from low socio-economic backgrounds are often seen as less talented, which can contribute to experiences of discrimination. "While a man with very good grades is more likely to be judged as a genius, women with the same achievements are more likely to be seen as hard-working, for example," explains Christina Bauer. People from families with a lower socio-economic status are also generally seen as less capable. Social psychologist Christina Bauer and her colleague Veronika Job, both from the University of Vienna, have now investigated how this social perception affects the self-image of these people and how their life paths are subsequently influenced by it. 

Female gender and low socio-economic status – less talent?

Bauer and Job conducted two studies with a total of 1,600 students in Germany and the USA. The result: compared to all subgroups, women from lower socio-economic backgrounds rated themselves as the least talented – even if they performed just as well in their studies as everyone else. "Our conclusion: society's external image and social hierarchies also have a very strong influence on self-image," says Bauer. 

This socialized distortion of self-perception is not without consequences: "Women therefore have less confidence in themselves, which reduces their chances of success and means that some industries and areas of society are very one-sidedly male-dominated and not very diverse," explains Bauer. For example, women with a low socio-economic status feel less comfortable in areas where talent is expected, are less confident and therefore make less of a contribution.  This applies, for example, to the STEM fields (mathematics, computer science, natural sciences and technology), jobs such as management consultancies, or even hobbies such as chess. "This view has far-reaching consequences for the chances of success of those affected in these areas," says Bauer. 

Diligence principle instead of talent focus as a possible solution

The authors also suggest solution strategies: In a previously published experiment, Bauer was able to show that women with a lower socio-economic status do not consider themselves to be less hard-working. The current study shows, however, that they consider themselves to be less talented. One way to mitigate disadvantages would therefore be to give greater social recognition to the importance of qualities such as diligence and hard work rather than talent. "This recognition can take place on different levels: How we talk about high achievers - instead of praising geniuses, and looking down on 'nerds', appreciating people for their hard work. Or how we give feedback – constructive feedback that makes it clear how people can improve, rather than just praise or criticism without a development perspective," says Bauer.

Why this distorted self-image occurs will be the subject of further studies. "Stereotypes or different experiences with challenges, which are misinterpreted as a sign of a lack of talent, could play a role," says Bauer.

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JOURNAL

Learning and Instruction

DOI

10.1016/j.learninstruc.2023.101865 

ARTICLE TITLE

Double Disadvantage: Female first-generation-students think of themselves as least talented, contributing to disproportionate disadvantage.

 

Bacteria load their syringes

Pathogenic bacteria use molecular "shuttle services" to fill their injection apparatus with the right product

Peer-Reviewed Publication

MAX-PLANCK-GESELLSCHAFT

 

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SINGLE-PARTICLE TRACKING PHOTOACTIVATED LOCALIZATION MICROSCOPY (SPTPALM) IS A TECHNIQUE TO VISUALIZE THE MOVEMENT OF INDIVIDUAL PROTEINS. WHILE SOME OF THE SHUTTLE COMPONENTS OF THE INJECTISOME ARE BOUND TO THE NEEDLES (WHITE, FIRMLY BOUND DOTS ON THE OUTSIDE OF THE BACTERIUM), OTHER SHUTTLE PROTEINS COMB THROUGH THE BACTERIUM (RED AND BLUE SHADING). IF THEY ENCOUNTER AN EFFECTOR, THEY BIND TO IT, WHICH CAN BE RECOGNIZED BY THE FACT THAT THEY SLOW DOWN, AND DELIVER IT TO THE NEEDLES, FROM WHERE A NEW SHUTTLE PROTEIN SETS OFF ON ITS SEARCH.

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CREDIT: STEPHAN WIMMI/ ALEXANDER BALINOVIC

Disease-causing bacteria of the genus Salmonella or Yersinia can use tiny injection apparatuses to inject harmful proteins into host cells, much to the discomfort of the infected person. However, it is not only with a view to controlling disease that researchers are investigating the injection mechanism of these so-called type III secretion systems, also known as "injectisomes".

If the structure and function of the injectisome were fully understood, researchers would be able to hijack it to deliver specific drugs into cells, such as cancer cells. In fact, the structure of the injectisome has already been elucidated. However, it remained unclear how the bacteria load their syringes so that the right proteins are injected at the right time.

Mobile components of the injectisome search for proteins

A team of scientists led by Andreas Diepold from the Max Planck Institute for Terrestrial Microbiology in Marburg and Ulrike Endesfelder from the University of Bonn has now been able to answer this question: mobile components of the injectisome comb through the bacterial cell in search of the proteins to be injected, so-called effectors. When they encounter an effector, they transport it like a shuttle bus to the gate of the injection needle.

"How proteins of the sorting platform in the cytosol bind to effectors and deliver the cargo to the export gate of the membrane-bound injectisome is comparable to the processes at a freight terminal", explains Stephan Wimmi, first author of the study as a postdoctoral researcher in Andreas Diepold's laboratory. "We think that this shuttle mechanism helps to make the injection efficient and specific at the same time - after all, the bacteria have to inject the right proteins quickly to avoid being recognized and eliminated by the immune system, for example."

To gain this insight into the important loading mechanism of the injectisome, the researchers had to apply new techniques. "Conventional methods, which are normally used to detect that proteins bind to each other, did not work to answer this question - possibly because the effectors are only bound for a short time and then immediately injected," explains Andreas Diepold, research group leader at the Max Planck Institute and co-leader of the study. "That's why we had to analyse this binding in situ in the living bacteria.”

“To measure these transient interactions we made use of two novel approaches that work in living cells, proximity labeling and single-particle tracking,” adds Ulrike Endesfelder, whose group worked on the study in three different locations – the Max Planck Institute in Marburg, Carnogie Mellon University in Pittsburgh, PA, USA, and at the University in Bonn. Proximity labeling, in which a protein marks its immediate neighbors like a paintbrush, enabled them to show that the effectors in the bacterium bind to the mobile injectisome components. This binding was examined in more detail using single particle tracking, a high-resolution microscopy method that can follow individual proteins in cells. These methods, which the team refers to as "in situ biochemistry", i.e. biochemical investigations on site, made the breakthrough possible.

The researchers next want to use their method to investigate other mechanisms that bacteria use to cause infections. "The more we know about how bacteria use these systems during an infection, the better we can understand how we can influence them - be it to prevent infections or to modify the systems in order to use them in the fields of medicine or biotechnology,” says Andreas Diepold.

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JOURNAL

Nature Microbiology

DOI

10.1038/s41564-023-01545-1 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Cytosolic sorting platform complexes shuttle type III secretion system effectors to the injectisome in Yersinia enterocolitica.

ARTICLE PUBLICATION DATE

3-Jan-2024

 

Early primates likely lived in pairs

Peer-Reviewed Publication

UNIVERSITY OF ZURICH

Primates – and this includes humans – are thought of as highly social animals. Many species of monkeys and apes live in groups. Lemurs and other Strepsirrhines, often colloquially referred to as “wet-nosed” primates, in contrast, have long been believed to be solitary creatures, and it has often been suggested that other forms of social organization evolved later. Previous studies have therefore attempted to explain how and when pair-living evolved in primates.

More recent research, however, indicates that many nocturnal Strepsirrhines, which are more challenging to investigate, are not in fact solitary but live in pairs of males and females. But what does this mean for the social organization forms of the ancestors of all primates? And why do some species of monkey live in groups, while others are pair-living or solitary?

Different forms of social organization

Researchers at the Universities of Zurich and Strasbourg have now examined these questions. For their study, Charlotte Olivier from the Hubert Curien Pluridisciplinary Institute collected detailed information on the composition of social units in primate populations in the wild. Over several years, the researchers built a detailed database, which covered almost 500 populations from over 200 primate species, from primary field studies.

More than half of the primate species recorded in the database exhibited more than one form of social organization. “The most common social organization were groups in which multiple females and multiple males lived together, for example chimpanzees or macaques, followed by groups with only one male and multiple females – such as in gorillas or langurs,” says last author Adrian Jaeggi from the University of Zurich. “But one-quarter of all species lived in pairs.”

Smaller ancestors coupled up

Taking into account several socioecological and life history variables such as body size, diet or habitat, the researchers calculated the probability of different forms of social organization, including for our ancestors who lived some 70 million years ago. The calculations were based on complex statistical models developed by Jordan Martin at UZH’s Institute of Evolutionary Medicine.

To reconstruct the ancestral state of primates, the researchers relied on fossils, which showed that ancestral primates were relatively small-bodied and arboreal – factors that strongly correlate with pair-living. “Our model shows that the ancestral social organization of primates was variable and that pair-living was by far the most likely form,” says Martin. Only about 15 percent of our ancestors were solitary, he adds. “Living in larger groups therefore only evolved later in the history of primates.”

Pairs with benefits

In other words, the social structure of early primates was likely more similar to that of humans today than previously assumed. “Many, but by no means all of us, live in pairs while also being a part of extended families and larger groups and societies,” Jaeggi says. However, pair-living among early primates did not equate to sexual monogamy or cooperative infant care, he adds. “It is more likely that a specific female and a specific male would be seen together for most of the time and share the same home range and sleeping site, which was more advantageous to them than solitary living,” explains last author Carsten Schradin from Strasbourg. This enabled them to fend off competitors or keep each other warm, for example.

Literature:

Charlotte-Anaïs Olivier, Jordan Martin, et al. Primate Social Organization Evolved from a Flexible Pair-Living Ancestor, Proceedings of the National Academy of Sciences, 28 December 2023. Doi: 10.1073/pnas.2215401120.

 

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2215401120 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Primate Social Organization Evolved from a Flexible Pair-Living Ancestor

 

Magnetic fields in the Cosmos: dark matter could help us discover their origin

We don't know how they formed. Now a new theoretical research tells how the invisible part of our Universe could help us discover it, suggesting a primordial genesis, even within a second of the Big Bang

Peer-Reviewed Publication

SCUOLA INTERNAZIONALE SUPERIORE DI STUDI AVANZATI

 

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IN THE STUDY, RESEARCHERS SHOWED THAT IF MAGNETIC FIELDS ARE INDEED PRIMORDIAL THEN IT COULD CAUSE AN INCREASE IN DARK MATTER DENSITY PERTURBATIONS ON SMALL SCALES. THE ULTIMATE EFFECT OF THIS PROCESS WOULD BE THE FORMATION OF MINI-HALOS OF DARK MATTER, WHICH, IF DETECTED WOULD HINT TOWARDS A PRIMORDIAL NATURE OF MAGNETIC FIELDS.

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CREDIT: IMAGE BY LUCIE CHRASTECKA

The mini-halos of dark matter scattered throughout the Cosmos could function as highly sensitive probes of primordial magnetic fields. This is what emerges from a theoretical study conducted by SISSA and published in Physical Review Letters. Present on immense scales, magnetic fields are found everywhere in the Universe. However, their origin are still subjects of debate among scholars. An intriguing possibility is that magnetic fields originated near the birth of the universe itself, that is they are primordial magnetic fields. In the study, researchers showed that if magnetic fields are indeed primordial then it could cause an increase in dark matter density perturbations on small scales. The ultimate effect of this process would be the formation of mini-halos of dark matter, which, if detected would hint towards a primordial nature of magnetic fields. Thus, in an apparent paradox, the invisible part of our Universe could be useful in resolving the nature of a component of the visible one.

Shedding light on the formation of Magnetic Fields

"Magnetic fields are ubiquitous in the Cosmos," explains Pranjal Ralegankar of SISSA, the author of the research. "A possible theory regarding their formation suggests that those observed so far could be produced in the early stages of our Universe. However, this proposition lacks explanation in the standard model of physics. To shed light on this aspect and find a way to detect “primordial” magnetic fields, with this work we propose a method that we could define as 'indirect.' Our approach is based on a question: What is the influence of magnetic fields on dark matter?". It is known that there is no direct interaction. Still, as Ralegankar explains, “there is an indirect one that occurs through gravity”.

Right from the primordial Universe

Primordial magnetic fields can enhance density perturbations of electrons and protons in the primordial Universe. When these become too large, they influence the magnetic fields themselves. The consequence is the suppression of fluctuations on a small scale. Ralegankar explains: "In the study, we show something unexpected. The growth in baryon density gravitationally induces the growth of dark matter perturbations without the possibility of subsequent cancellation. This would result in their collapse on small scales, producing mini-halos of dark matter." The consequence, continues the author, is that although fluctuations in the density of baryonic matter are cancelled, they would leave traces through the mini-halos, all solely through gravitational interactions.

"These theoretical findings", concludes Pranjal Ralegankar, "also suggest that the abundance of mini-halos is determined not by the present presence of primordial magnetic fields but rather by their strength in the primordial Universe. Thus, a detection of dark matter mini-halos would reinforce the hypothesis that magnetic fields formed very early, even within 1 second after the Big Bang."

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JOURNAL

Physical Review Letters

DOI

10.1103/PhysRevLett.131.231002 

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Dark Matter Minihalos from Primordial Magnetic Fields

 

New reasons eating less fat should be one of your resolutions

High fat impairs immune, intestinal, and brain health

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - RIVERSIDE

 

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EVIDENCE MOUNTS THAT A LONG-TERM DIET HIGH IN FAT IS NOT HEALTHY.

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CREDIT: IDAFIUN

A UC Riverside study to motivate your new year’s resolutions: it demonstrates that high-fat diets affect genes linked not only to obesity, colon cancer and irritable bowels, but also to the immune system, brain function, and potentially COVID-19 risk.

While other studies have examined the effects of a high-fat diet, this one is unusual in its scope. UCR researchers fed mice three different diets over the course of 24 weeks where at least 40% of the calories came from fat. Then, they looked not only at the microbiome, but also at genetic changes in all four parts of the intestines. 

One group of mice ate a diet based on saturated fat from coconut oil, another got a monounsaturated, modified soybean oil, a third got an unmodified soybean oil high in polyunsaturated fat. Compared to a low-fat control diet, all three groups experienced concerning changes in gene expression, the process that turns genetic information into a functional product, such as a protein.

“Word on the street is that plant-based diets are better for you, and in many cases that’s true. However, a diet high in fat, even from a plant, is one case where it’s just not true,” said Frances Sladek, a UCR cell biology professor and senior author of the new study.

A new Scientific Reports paper about the study documents the many impacts of high-fat diets. Some of the intestinal changes did not surprise the researchers, such as major changes in genes related to fat metabolism and the composition of gut bacteria. For example, they observed an increase in pathogenic E. coli and a suppression of Bacteroides, which helps protect the body against pathogens. 

Other observations were more surprising, such as changes in genes regulating susceptibility to infectious diseases. “We saw pattern recognition genes, ones that recognize infectious bacteria, take a hit. We saw cytokine signaling genes take a hit, which help the body control inflammation,” Sladek said. ‘So, it’s a double whammy. These diets impair immune system genes in the host, and they also create an environment in which harmful gut bacteria can thrive.”

The team’s previous work with soybean oil documents its link to obesity and diabetes, both major risk factors for COVID. This paper now shows that all three high-fat diets increase the expression of ACE2 and other host proteins that are used by COVID spike proteins to enter the body.

Additionally, the team observed that high-fat food increased signs of stem cells in the colon. “You’d think that would be a good thing, but actually they can be precursors to cancer,” Sladek said.  

In terms of effects on gene expression, coconut oil showed the greatest number of changes, followed by the unmodified soybean oil. Differences between the two soybean oils suggest that polyunsaturated fatty acids in unmodified soybean oil, primarily linoleic acid, play a role in altering gene expression. 

Negative changes to the microbiome in this study were more pronounced in mice fed the soybean oil diet. This was unsurprising, as the same research team previously documented other negative health effects of high soybean oil consumption. 

In 2015, the team found that soybean oil induces obesity, diabetes, insulin resistance, and fatty liver in mice. In 2020, the researchers team demonstrated the oil could also affect genes in the brain related to conditions like autism, Alzheimer’s disease, anxiety, and depression. 

Interestingly, in their current work they also found the expression of several neurotransmitter genes were changed by the high fat diets, reinforcing the notion of a gut-brain axis that can be impacted by diet.

The researchers have noted that these findings only apply to soybean oil, and not to other soy products, tofu, or soybeans themselves. “There are some really good things about soybeans. But too much of that oil is just not good for you,” said UCR microbiologist Poonamjot Deol, who was co-first author of the current study along with UCR postdoctoral researcher Jose Martinez-Lomeli.

Also, the studies were conducted using mice, and mouse studies do not always translate to the same results in humans. However, humans and mice share 97.5% of their working DNA. Therefore, the findings are concerning, as soybean oil is the most commonly consumed oil in the United States, and is increasingly being used in other countries, including Brazil, China, and India.

By some estimates, Americans tend to get nearly 40% of their calories from fat, which mirrors what the mice were fed in this study. “Some fat is necessary in the diet, perhaps 10 to 15%. Most people though, at least in this country, are getting at least three times the amount that they need,” Deol said. 

Readers should not panic about a single meal. It is the long-term high-fat habit that caused the observed changes. Recall that the mice were fed these diets for 24 weeks. “In human terms, that is like starting from childhood and continuing until middle age. One night of indulgence is not what these mice ate. It’s more like a lifetime of the food,” Deol said. 

That said, the researchers hope the study will cause people to closely examine their eating habits. 

“Some people think, ‘Oh, I’ll just exercise more and be okay. But regularly eating this way could be impacting your immune system and how your brain functions,” Deol said. “You may not be able to just exercise away these effects.”
 

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-023-49555-7 

ARTICLE TITLE

Impact of various high fat diets on gene expression and the microbiome across the mouse intestines

 

Job ads with wide pay ranges can deter applicants

Peer-Reviewed Publication

WASHINGTON STATE UNIVERSITY

PULLMAN, Wash. – As more states require employers to list compensation on job ads, a trending strategy to use very wide pay ranges could potentially harm recruitment, according to a Washington State University study.

The study, published in the Journal of Applied Psychology, found that participants in three different experiments were more likely to respond negatively to job ads with very wide pay ranges, viewing those employers as less trustworthy. Prior surveys have found that most people report they would trust organizations that include pay ranges in their postings more than those that do not, but as this study indicates, the way potential pay is presented also matters.

“It’s not just a choice between including a pay range or not – how compensation information is communicated matters, and at least in this study, having a very wide range might send a negative signal to potential applicants,” said study author Kristine Kuhn, a WSU Carson College of Business researcher.

How the ad explained the wide pay range also had an effect. In one of the experiments, participants were even less attracted to the organization if a very wide pay range included a statement that the offer amount would depend on the candidate’s qualifications. On the other hand, a more seemingly objective explanation that the offer would depend on the candidate’s geographic location tended to improve impressions of the employer.

Historically, most job postings in the U.S. did not include numerical pay information, but in recent years several states, including Washington, California, Colorado and New York, have enacted transparency legislation requiring many recruiters to list pay ranges – in part because there is evidence it increases equity.

Seeing an emerging trend in job postings with large pay ranges, Kuhn set up three experiments with different groups of participants to test the effect of this practice. In each experiment, some participants saw ads with wide salary ranges, such as a gap of $50,000 or more between the low and high point, while others saw ads with a narrower gap of around $10,000. The candidates then responded to questions about their perceptions of the organization posting the ad.

Participants in the initial experiment were college students; the second experiment surveyed 350 college graduates using an online panel, and the third experiment involved 245 participants with recent job search experience. Across all three experiments, on average ads with larger pay ranges evoked less favorable impressions of the employers than the narrower ranges.

In the last experiment which had an ad with a very large pay range of $58,100-$152,500, the participants provided written answers about how they viewed the employer. This revealed a high level of cynicism among some who called the wide pay range “dishonest,” “disingenuous” and “ludicrous.”

As one participant put it: “The large range implies that they tend to devalue their employees. I doubt they would actually offer anyone applying for this position a salary at the top range, regardless of credentials.”

There were some outliers, however, who viewed the large range as a positive, seeing the high top number as showing possible “room for growth without needing a promotion to another job.”

Ideally, advertising a pay range should streamline the recruiting process, Kuhn said, so the recruiter and applicant on are on the same page. However, some organizations, especially smaller ones, may not have well-defined job structures, so the large pay ranges in job ads may indicate they want to tailor the position to the candidates who respond.

“There probably is a goldilocks area of a just right pay range where it gives the employer some flexibility without sending negative signals to prospective applicants,” said Kuhn. “Also, while from a legal standpoint they may be required to advertise an expected pay range, employers and job candidates can still negotiate.”

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JOURNAL

Journal of Applied Psychology

DOI

10.1037/apl0001165 

ARTICLE TITLE

Ambiguity in advertised compensation: Recruiting implications of nominal compliance with pay transparency legislation.

 

Study demonstrates potency of synthetic antibiotic against serious chronic infections

Peer-Reviewed Publication

UNIVERSITY OF LIVERPOOL

A new synthetic antibiotic developed by University of Liverpool researchers is shown to be more effective than established drugs against ‘superbugs’ such as MRSA, a new study shows.

The study demonstrates the potent activity of the antibiotic, teixobactin, against bacterial biofilms. Biofilms are clusters of bacteria that are attached to a surface and/or to each other – which are associated with serious chronic infections in humans.

Nearly five million people lose their lives due to antibiotic resistance-associated infections and millions more live with poor quality of life due to treatment failures. Antimicrobial resistance (AMR) is increasing and an AMR review commissioned by the UK Government has predicted that by 2050 an additional 10 million people will succumb to drug resistant infections each year.  The development of new antibiotics which can be used as a last resort when other drugs are ineffective is a crucial area of study for healthcare researchers around the world.

This work builds on pioneering research by the University’s Dr Ishwar Singh, an expert in antimicrobial drug discovery and development and medicinal chemistry. A team of researchers led by Dr Singh developed simplified synthetic versions of the natural molecule teixobactin, which is used by producer bacteria to kill other bacteria in soil.

They have tested a unique library of synthetic versions of the ‘game changing’ antibiotic, optimising key features of the drug to enhance its efficacy and safety, plus enabling it to be inexpensively produced at scale.

For this latest study, the researchers designed and synthesised highly potent teixobactin analogues but swapped out key bottleneck building block L-allo-enduracididine with the commercially available low cost simplified building blocks such as non proteogenic amino acids. As a result, the analogues are now effective against the broad range of resistant bacterial pathogens including bacterial isolates from patients and bacterial biofilms.

This is another important step in adapting the natural teixobactin molecule to make it suitable for human use.

Dr Ishwar Singh said: “Teixobactin molecules have the potential to provide new treatment options against multi drug resistant bacterial and biofilm related infections to improve and save lives globally. Our study provides a promising foundation for further research, and opens avenues to explore the application of teixobactin in various health related biofilm contexts, including surgical site infections, implant-related surgeries and cystic fibrosis patients.”

This work is funded by Innovate UK, the Department of Health and Social Care and Rosetrees Trust. In addition to the University of Liverpool team it involves researchers from Singapore Eye Research Institute, Nanyang Technological University (Singapore), University of Ghent (Belgium), University of Utrecht (Netherlands), and the University of Lincoln (UK).

The full study Development of teixobactin analogues containing hydrophobic, nonproteogenic amino acids that are highly potent against multidrug-resistant bacteria and biofilms, published in the European Journal of Medicinal Chemistry, is available here: https://doi.org/10.1016/j.ejmech.2023.115853

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JOURNAL

European Journal of Medicinal Chemistry

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Development of teixobactin analogues containing hydrophobic, nonproteogenic amino acids that are highly potent against multidrug-resistant bacteria and biofilms