Friday, September 03, 2021

 

Improving buyer-freelancer communications in the gig economy

News from the Journal of Marketing

Peer-Reviewed Publication

AMERICAN MARKETING ASSOCIATION

Researchers from University of Melbourne, Vrije Universiteit, Babson College, and University of Surrey published a new paper in the Journal of Marketing that provides generalized communication principles, and examples of how to apply them, for successful bid writing in the gig economy.

The study, forthcoming in the Journal of Marketing, is titled “Communication in the Gig Economy: Buying and Selling in Online Freelance Marketplaces” and is authored by Stephan Ludwig, Dennis Herhausen, Dhruv Grewal, Liliana Bove, Sabine Benoit, Ko de Ruyter, and Peter Urwin.

The gig economy is global and growing exponentially. In the US alone, millions of buyers and freelancers in freelance marketplaces contribute $1.2 trillion in value to the economy. Online freelance marketplaces, such as Upwork, Fiverr, PeoplePerHour, and Toptal have prompted massive transformations of work. In relatively anonymous interactions via text-based messages, buyers first post call-for-bids for their gigs. In turn, interested freelancers submit bids to offer their services.

Yet, while 59% of U.S. companies use a flexible workforce to some degree, more than one-third of their gigs are never filled or completed. The research team explains that “Uncertainty during these text-based interactions leads to high rates of gigs that go unfulfilled, reduced freelancers’ bid success, or less-than-optimal pricing for freelancers. Our investigation uncovers principles for writing call-for-bids and bids that manage that uncertainty and lead to greater success filling gigs and finding work.”

How Buyers Can Write a Good Call-for-Bids

Freelancers choose whether to offer their services in response to a buyer’s call for bids. The number of freelancers who respond is consequential for the buyer because attracting more bids implies a greater likelihood of finding a suitable freelancer. Here are key principles buyers can use to entice freelancers to bid: 
 
• Moderate length: While buyers may be inclined to supply as much information as possible, successful buyers keep their calls for bids moderately succinct. 

• Enough task information: Buyers should focus on providing information about the task and the required skills. Importantly, providing excessive task information is ineffective, even if it might reduce freelancers’ uncertainty. Excessive details can make the gig appear too overwhelming, restrictive, or prescriptive and thus not appealing to freelancers. 

• Limit personal information: Buyers may want to provide a lot of personal information in their call for bids. Yet, this research finds that the less buyers describe themselves (and instead focus on describing the task), the more freelancers apply. Extensive personal information provision by buyers is unusual, potentially even inappropriate, in initial online exchanges. 

• Enough concreteness: Buyers can vary the concreteness of the gig description. Greater concreteness can be more efficient because freelancers can process the information with less time and effort. Concrete terms help by making information more perceptible, precise, and specific. Only a moderate to high level of concreteness is attractive to freelancers, though. Notably, if buyers are too concrete in their calls for bids, the task might appear narrow, which reduces the gig’s appeal.

• Limit affective intensity: Affective intensity reflects the proportion of emotive terms included in a message. Greater intensity tends to be more persuasive, memorable, and accessible than communication that is unemotional. However, calls for bids are more effective if they are formulated relatively impassively. Overly enthusiastic project descriptions, for example, might raise freelancers’ suspicion that the project is too good to be true.

How Freelancers Can Write Good Bids

Buyers also face uncertainty when deciding whom to hire and how much to pay. By managing these uncertainties through their bids, freelancers can affect their chances of winning bids and their price premiums. Freelancers are not necessarily natural marketers, but here is what they can do in their bid formulations to increase their marketability:
 
• Stars matter, communication too: Existing online reputation systems provide some assistance, but they also create entry barriers to new freelancers who first must earn good ratings. Fortunately, winning gigs and achieving price premiums also depend on freelancers’ communication. 

• Mimicking the buyer: In line with the mantra of adaptive selling, the call for bids provides a starting point, such that mimicking the buyer’s task information and affective intensity increases freelancers’ success—even if the buyer provides few task details or seems very impassive. 

• Personal information and concreteness: Freelancers should always offer personal information and be concrete. Even if a buyer does not provide personal information or the call is relatively abstract, freelancers’ chances of success and price premiums increase if their bids contain more personal information and are at least somewhat concrete.

• Build relationships: The strongest predictor of bid success is a preexisting buyer relationship. Thus, freelancers should focus on developing buyer relationships. 
  
This research shows that buyers and freelancers in online freelance marketplaces should carefully manage uncertainty in their communications to improve their chances of achieving success in the gig economy.

Full article and author contact information available at: https://doi.org/10.1177/00222429211030841

About the Journal of Marketing 

The Journal of Marketing develops and disseminates knowledge about real-world marketing questions useful to scholars, educators, managers, policy makers, consumers, and other societal stakeholders around the world. Published by the American Marketing Association since its founding in 1936, JM has played a significant role in shaping the content and boundaries of the marketing discipline. Christine Moorman (T. Austin Finch, Sr. Professor of Business Administration at the Fuqua School of Business, Duke University) serves as the current Editor in Chief.
https://www.ama.org/jm

About the American Marketing Association (AMA) 

As the largest chapter-based marketing association in the world, the AMA is trusted by marketing and sales professionals to help them discover what is coming next in the industry. The AMA has a community of local chapters in more than 70 cities and 350 college campuses throughout North America. The AMA is home to award-winning content, PCM® professional certification, premiere academic journals, and industry-leading training events and conferences.
https://www.ama.org

 

Researchers discover connection between brain’s opioid system and eating behavior

Peer-Reviewed Publication

UNIVERSITY OF TURKU

Brain regions 

IMAGE: BRAIN REGIONS WHERE CONNECTIONS BETWEEN THE OPIOID SYSTEM AND EATING TRIGGERED BY EXTERNAL STIMULI WERE DISCOVERED. YELLOW COLOR INDICATES A STRONGER CONNECTION. view more 

CREDIT: UNIVERSITY OF TURKU

Brain regulation of feeding behavior traits has remained incompletely understood. In their latest study, researchers at the Turku PET Centre, Finland, discovered a connection between the function of the opioid system and food craving triggered by appetitive external stimuli.

Animal studies have established that the brain’s opioid and endocannabinoid systems are important in regulating eating behavior and mediate the food reward experience. For instance, alterations in these systems’ signaling have been associated with obesity. In general, both internal signals of the body, such as fluctuation in blood sugar levels, and external stimuli, such as food advertisements, can spark an appetite in humans.

In their new study, researchers at the University of Turku, Finland, investigated the connection between the brain’s opioid and endocannabinoid signaling and different types of eating behavior. They discovered that the function of the opioid system is connected to eating triggered by external stimuli.

“The less binding sites there were for the opioids, the greater was the tendency to eat in response to external stimuli, such as seeing appetizing food. Moreover, the number of binding sites for endocannabinoids was connected to several different types of eating behavior, describes first author,” Doctoral Candidate Tatu Kantonen from the University of Turku.

According to Kantonen, the results indicate that especially the opioid system could be a potential target for anti-obesity drugs in humans.

The research data was obtained from the AIVO database hosted by the Turku PET Centre.


Icarus can fly high and save on wax too


Risk from solar flares to planes is real but not worth costly mitigation

Peer-Reviewed Publication

KYOTO UNIVERSITY

How much of a risk do solar flares pose to airline passengers and staff? 

IMAGE: A RECENT STUDY SUGGESTS THAT AIRLINE TRAVEL MAY NOT CARRY AS MUCH RADIATION RISK AS PREVIOUSLY CONJECTURED. view more 

CREDIT: NAMI KIMURA/KYOTO UNIVERSITY

Kyoto, Japan -- "Don't fly too close to the sun," said Daedalus to Icarus. Flying too high would melt the wax in his wings, while going too low would cause the sea's moisture to create drag.

Commercial flight crews do not usually appear in Greek mythology, but they have to work with the occupational hazard of aviation radiation exposure.

Aviation guidelines aim to mitigate the effects of radiation, mainly caused by galactic cosmic rays and solar energetic particles, or SEP. The fluxes in the former are stable and predictable: dose rates are no higher than 10 µSv/h at the normal flight altitude of 12 km.

But in the case of SEP, does the frequency of detected solar flares justify the costs of countermeasures? Current mitigation procedures instruct planes to lower altitude or change or cancel flight paths altogether, significantly raising expenses.

A research team led by Kyoto University's Yosuke Yamashiki set out to answer this question by assessing eight flight routes during five ground level enhancements, or GLE: unpredicted radiation spikes recorded by ground-based detectors.

"During a large solar particle event we see sudden SEP fluxes with dose rates exceeding 2 mSv/h," says Yamashiki, "but these are rare and short-lived."

Writing in the journal Scientific Reports, the researchers estimate that the maximum flight route dose and dose rate arising from major GLE events would need to exceed 1.0 mSv and 80 µSv/h, respectively, for countermeasures to be deemed necessary.

However, annual frequency estimates of GLE events of that magnitude came to only once every 47 and 17 years for maximum dose and dose rate.

So do the risks justify the costs?

"There is no denying the potentially debilitating effects of radiation exposure," continues Yamashiki, "but the data suggest that current measures may be over-compensating for the actual risks."

 

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The paper "Probabilistic Risk Assessment of Solar Particle Events Considering the Cost of Countermeasures to Reduce the Aviation Radiation Dose" appeared 2 September 2021 in the journal Scientific Reports, with doi: 10.1038/s41598-021-95235-9

 

About Kyoto University

Kyoto University is one of Japan and Asia's premier research institutions, founded in 1897 and responsible for producing numerous Nobel laureates and winners of other prestigious international prizes. A broad curriculum across the arts and sciences at both undergraduate and graduate levels is complemented by numerous research centers, as well as facilities and offices around Japan and the world. For more information please see: http://www.kyoto-u.ac.jp/en

 

Anatomy of the impact of a protostellar jet in the Orion Nebula

Peer-Reviewed Publication

INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC)

View of HH204, a Herbig-Haro object in the Orion Nebula 

IMAGE: THE LEFT PANEL SHOWS THE ORION NEBULA OBSERVED WITH THE HUBBLE SPACE TELESCOPE, PICKING OUT THE AREA AROUND HH204. IN THE RIGHT PANEL, WE CAN SEE IN DETAIL THE STRUCTURE OF HH204 AND OF ITS APPARENT COMPANION, HH203. IN THIS PANEL, THE IMAGES BY THE HUBBLE SPACE TELESCOPE TAKEN DURING 20 YEARS AND ARTIFICIALLY HIGHLIGHTED WITH DIFFERENT COLOURS SHOW THE ADVANCE OF THE JETS OF GAS THROUGH THE ORION NEBULA. CREDIT: GABRIEL PÉREZ DÍAZ, SMM (IAC). view more 

CREDIT: CREDIT: GABRIEL PÉREZ DÍAZ, SMM (IAC).

An international team led by researchers from the Instituto de Astrofísica de Canarias (IAC) has uncovered, with an new high degree of detail, the physical and chemical effects of the impact of a protostellar jet in the interior of the Orion Nebula. The study was made using observations with the Very Large Telescope (VLT) and 20 years of images with the Hubble Space Telescope (HST). The observations show evidence of compression and heating produced by the shock front, and the destruction of dust grains, which cause a dramatic increase in the gas phase abundance of the atoms of iron, nickel, and other heavy elements in the Orion Nebula. The results were recently published in The Astrophysical Journal.

VIDEO HH204, a Herbig-Haro object in [VIDEO] | EurekAlert! Science News Releases

The Orion Nebula, one of the known and brightest objects in the night sky, is the nearest region of massive star formation to Earth, and it has a complex and extensive gas structure. Some of the newborn stars within it emit jets of gas at high speed which, when they impact their surroudings, produce shock fronts which compress and heat the nebular gas. These impact zones are bow-shaped, and are called Herbig-Haro objects, after their discoverers, the US astonomer George Herbig, and the Mexican astronomer Guillermo Haro.

These objects have been observed previously in many dark nebulae, where the cold gas is neutral, and its main source of energy is the heat generated by the shock. However, the jets of gas in the Orion Nebula are immersed in a large radiation field produced by the most massive stars in the Trapezium of Orion, situated at the centre of the nebula. Due to this radiation the gas within the shock front and also the gas compressed after it has passed through, is warm and ionized, and this allows us to measure precisely the physical conditions and the chemical composition of the jet.

The research carried out by a team of astronomers in Spain, Mexico and the United States, led by José Eduardo Méndez Delgado, a doctoral student at the IAC and the University of La Laguna (ULL), has uncovered the complex relations between the ionic abundances of the gas and its physical conditions in HH204, one of the most prominent Herbig-Haro objects in the Orion Nebula.

“Our work shows that the in the shock front of HH204 the gas abundances of heavy elements such as iron and nickel are increased by up to 350% compared to the values usually found in the Orion Nebula, and this allows us to determine the proportion of other chemical elements more accurately, which contributes to an improved knowledge of the chemical evolution in the solar neighbourhood”, explains José Eduardo Méndez Delgado, the first author of the article.

“As well as the heavy element enrichment in the gas phase, we have observed a heated post-shock zone which comprises a very small fraction of the gas, and which lets us understand the different layers of the structure of the Herbig-Haro object generated by the impact of the shock front”, says César Esteban, and IAC researcher and a co-author of the article.

“The origin of HH204 appears to be associated with one of the most brilliant and star formation rich zones of the Orion Nebula, the regions called Orion South, although there are many interactions of gas which appear to feed it from several directions”, adds William Henney, a researcher at the Institute of Radioastronomy and Astrophysics at the National Autonomous University of Mexico, and a co-author of the article.

“Thanks to the images of the Hubble Space Telescope we have shown that HH204 is propagating at an angle of 32º with the plane of the sky, which lets us observe the compression of the gas transversely as we approach the shock front”, points out Karla Arellano Córdova, a researcher at the University of Texas at Austin, and a co-author of the article.

“We have seen that the impact of these objects can be important when determining the local physical conditions in ionized nebulae. In fact, if we don’t take these effects into account we can make incorrect determinations of the chemical composition of the ionized nebulae, which are fundamental techniques for understanding the chemical evolution of the Universe”, sums up Jorge García Rojas, an IAC researcher and a co-author of the article.

Article: Méndez-Delgado, J. E.; Henney, W. J.; Esteban, C.; García-Rojas, J.; Mesa-Delgado, A. & Arellano-Córdova, K. Z. “Photoionized Herbig-Haro objects in the Orion Nebula through deep high-spectral resolution spectroscopy II: HH204”. The Astrophysical Journal. DOI: https://iopscience.iop.org/article/10.3847/1538-4357/ac0cf5#artAbst

- Arxiv: https://arxiv.org/abs/2106.08667

Astronomers create the first 3D-printed stellar nurseries

Researchers can now hold stellar nurseries in their hands thanks to 3D printing, revealing features often obscured in traditional renderings and animations

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

Stellar nursery models 

IMAGE: THE FIRST 3D-PRINTED STELLAR NURSERIES ARE HIGHLY POLISHED SPHERES ABOUT THE SIZE OF A BASEBALL, IN WHICH SWIRLING CLUMPS AND FILAMENTS REPRESENT STAR-FORMING CLOUDS OF GAS AND DUST. RESEARCHERS CREATED THE MODELS USING DATA FROM SIMULATIONS OF STAR-FORMING CLOUDS AND A SOPHISTICATED 3D PRINTING PROCESS IN WHICH THE FINE-SCALE DENSITIES AND GRADIENTS OF THE TURBULENT CLOUDS ARE EMBEDDED IN A TRANSPARENT RESIN. view more 

CREDIT: PHOTO BY SAURABH MHATRE

Astronomers can’t touch the stars they study, but astrophysicist Nia Imara is using 3-dimensional models that fit in the palm of her hand to unravel the structural complexities of stellar nurseries, the vast clouds of gas and dust where star formation occurs.

Imara and her collaborators created the models using data from simulations of star-forming clouds and a sophisticated 3D printing process in which the fine-scale densities and gradients of the turbulent clouds are embedded in a transparent resin. The resulting models—the first 3D-printed stellar nurseries—are highly polished spheres about the size of a baseball (8 centimeters in diameter), in which the star-forming material appears as swirling clumps and filaments.

“We wanted an interactive object to help us visualize those structures where stars form so we can better understand the physical processes,” said Imara, an assistant professor of astronomy and astrophysics at UC Santa Cruz and first author of a paper describing this novel approach published August 25 in Astrophysical Journal Letters.

An artist as well as an astrophysicist, Imara said the idea is an example of science imitating art. “Years ago, I sketched a portrait of myself touching a star. Later, the idea just clicked. Star formation within molecular clouds is my area of expertise, so why not try to build one?” she said.

She worked with coauthor John Forbes at the Flatiron Institute’s Center for Computational Astrophysics to develop a suite of nine simulations representing different physical conditions within molecular clouds. The collaboration also included coauthor James Weaver at Harvard University’s School of Engineering and Applied Sciences, who helped to turn the data from the astronomical simulations into physical objects using high-resolution and photo-realistic multi-material 3D printing.

The results are both visually striking and scientifically illuminating. “Just aesthetically they are really amazing to look at, and then you begin to notice the complex structures that are incredibly difficult to see with the usual techniques for visualizing these simulations,” Forbes said.

For example, sheet-like or pancake-shaped structures are hard to distinguish in two-dimensional slices or projections, because a section through a sheet looks like a filament.

“Within the spheres, you can clearly see a two-dimensional sheet, and inside it are little filaments, and that’s mind boggling from the perspective of someone who is trying to understand what’s going on in these simulations,” Forbes said.


CAPTION

In addition to spheres representing nine different simulations, the researchers also printed half-spheres to reveal the mid-plane data. Lighter material corresponds to regions of higher density, while darker areas represent regions of low density and voids.

CREDIT

Photo by Saurabh Mhatre

The models also reveal structures that are more continuous than they would appear in 2D projections, Imara said. “If you have something winding around through space, you might not realize that two regions are connected by the same structure, so having an interactive object you can rotate in your hand allows us to detect these continuities more easily,” she said.

The nine simulations on which the models are based were designed to investigate the effects of three fundamental physical processes that govern the evolution of molecular clouds: turbulence, gravity, and magnetic fields. By changing different variables, such as the strength of the magnetic fields or how fast the gas is moving, the simulations show how different physical environments affect the morphology of substructures related to star formation.

Stars tend to form in clumps and cores located at the intersection of filaments, where the density of gas and dust becomes high enough for gravity to take over. “We think that the spins of these newborn stars will depend on the structures in which they form—stars in the same filament will ‘know’ about each other’s spins,” Imara said.


CAPTION

Nia Imara is both an astrophysicist and an artist. A portrait of herself touching a star eventually led to the idea of creating physical models of stellar nurseries.

CREDIT

Image courtesy of Nia Imara


With the physical models, it doesn’t take an astrophysicist with expertise in these processes to see the differences between the simulations. “When I looked at 2D projections of the simulation data, it was often challenging to see their subtle differences, whereas with the 3D-printed models, it was obvious,” said Weaver, who has a background in biology and materials science and routinely uses 3D printing to investigate the structural details of a wide range of biological and synthetic materials.

“I’m very interested in exploring the interface between science, art, and education, and I’m passionate about using 3D printing as a tool for the presentation of complex structures and processes in an easily understandable fashion,” Weaver said. “Traditional extrusion-based 3D printing can only produce solid objects with a continuous outer surface, and that’s problematic when trying to depict, gases, clouds, or other diffuse forms. Our approach uses an inkjet-like 3D printing process to deposit tiny individual droplets of opaque resin at precise locations within a surrounding volume of transparent resin to define the cloud's form in exquisite detail.”

He noted that in the future the models could also incorporate additional information through the use of different colors to increase their scientific value. The researchers are also interested in exploring the use of 3D printing to represent observational data from nearby molecular clouds, such as those in the constellation Orion.

The models can also serve as valuable tools for education and public outreach, said Imara, who plans to use them in an astrophysics course she will be teaching this fall.

 

 

TRACS set the stage in flatworm regeneration

Transient regeneration-activated cell states can exist in tissues near to and distant from a wound site during planarian whole-body regeneration

Peer-Reviewed Publication

STOWERS INSTITUTE FOR MEDICAL RESEARCH

Reconstruction 

IMAGE: AN “ATLAS” REPRESENTATION CAPTURES THE CELLULAR COMPLEXITY OF FLATWORM REGENERATION. INDIVIDUAL FLATWORM CELLS ARE REPRESENTED BY DOTS, WITH COLORS CORRESPONDING TO COLLECTION TIME POINTS AND DISTANCES REPRESENTING SIMILARITY IN GENE EXPRESSION PROFILES. view more 

CREDIT: SÁNCHEZ ALVARADO LAB

KANSAS CITY, MO—People who fish and regularly use earthworms as bait may be familiar with the animal’s ability to regenerate a head or tail when cut in two. Yet while impressive, an earthworm’s regenerative capacity is child’s play compared with that of the planarian Schmidtea mediterranea. This species, a type of flatworm, can regrow an entire animal from tiny tissue fragments as minuscule as 1/279th of the animal.

How does this happen? What cell types contribute to this astounding regenerative capacity? Besides stem cells, which are obviously important, how many other cell types are important for regulating this process, and what do they do?

Recent research published September 2, 2021, in Nature Cell Biology by members of the Sánchez Alvarado Lab at the Stowers Institute for Medical Research provides some early answers to these complex questions.

“It was already known that the wound-induced epidermis and the wound-induced muscle played different roles in regeneration, but we wanted to understand the big picture,” explains lead author Blair Benham-Pyle, PhD, a postdoctoral scientist in the lab of Stowers Institute Executive Director and Chief Scientific Officer and Howard Hughes Medical Institute Investigator Alejandro Sánchez Alvarado, PhD.

“This is the first study that definitively found that all three germ layers (muscle, epidermis, and intestine) of Schmidtea mediterranea transcriptionally respond to amputation, and that both tissues near the wound site and far away from the wound site are contributing to regenerative capacity,” says Benham-Pyle.

“Regeneration was a little bit of a black box before—we knew some genes that were important, and we could look at how some genes were altered globally in response to amputation and during regeneration, but we didn’t know how individual cell types across the animal were changing their behavior or function. That’s what this experiment allowed us to characterize.”

“The dream experiment,” described Benham-Pyle, and what they ultimately accomplished, was to “characterize gene expression on the single-cell level, across all of the different cell types of a regenerating animal, over time.”

At first, the researchers considered doing the experiment using large-scale RNA sequencing because droplet-based single-cell sequencing—where every single cell is encapsulated in a lipid droplet with a barcode, and then lysed to label all mRNAs with that barcode— was not feasible at the scale needed for this experiment. But in early 2017, Sánchez Alvarado came across a preprint that had just been posted to bioRxiv reporting a new single-cell sequencing method named SplitSeq. Once Benham-Pyle had reviewed and discussed with Sánchez Alvarado the merits of the work in the preprint, they decided to give it a go. After several tries, a number of optimizations, and troubleshooting with the molecular biology and cytometry technology center teams, Benham-Pyle succeeded in bringing a new single-cell sequencing technology to the Stowers Institute.

After getting it to work, Benham-Pyle and colleagues captured almost 300,000 single cell transcriptomes across eight different tissues and the stem cell compartment in animals that had lost the ability to regenerate, compared with those that were capable of regenerating.

“This allowed us to look at all of the different cell types across the entire animal to see which responded to amputation and what genes were marking these cells as they changed and responded to regeneration,” explains Benham-Pyle.

The researchers found and characterized five different cell types, from all three germ layers, that transiently altered their transcriptional output after amputation. When genes enriched in these cell types were knocked down, says Benham-Pyle, “we found that all of them contribute to regeneration in different ways, being activated at different times and in different parts of the body.”

Some of their findings were more unexpected than others. For example, that muscle is important for patterning, and that the epidermis is important for early stem cell proliferation bursts during regeneration, was not as unexpected. The researchers were surprised, however, to discover rare cells, states induced during whole-body regeneration, called transient regeneration-activating cell states (TRACS), and to find that the intestine seems to be important for both stem cell maintenance and regulating tissue remodeling after amputation.

“I didn’t expect the intestine to globally change its output and remodel its function after injury,” says Benham-Pyle. “But if you think about it, it does make sense. The planarian normally grows its body plan based on its nutrient environment. The worm eats, and that fuels a burst of stem cell proliferation and the addition of new biomass. When you cut the animal, especially in extreme injury, it often loses its ability to eat. All of the growth and remodeling now needs to be fueled by nutrients already existing within the body plan. So, after amputation, the intestine alters its function to scavenge material from dying cells within the animal, and to convert those materials into new healthy cells in a regenerated worm.”

Acquiring and making sense of the data was a team effort.

“We had to do all of our manuscript revisions during the COVID-19 pandemic, when we were at 50% research capacity,” recounts Benham-Pyle. “Sean McKinney and the Microscopy Center found ways to automate imaging, and we worked out a system where I could give them forty to eighty slides at a time, of all different samples and RNAi conditions, to be imaged on overnight runs. They were able to generate terabytes of imaging data for us on the scanning confocal microscope, which helped give us the big lift we needed to get the paper accepted. They set a very high bar for microscopy facilities.”

Other coauthors of the study include: Carolyn E. Brewster, a bioinformatics specialist who helped analyze the data generated from the experiment, and was instrumental in creating the website associated with the paper; Aubrey M. Kent, who helped describe some of the first RNAi phenotypes that came out of the dataset (she is now following up on some of the epidermal genes that were found to affect the stem cell compartment); Frederick G. Mann, PhD, who helped clone many of the genes that Benham-Pyle screened and characterized in the paper; Shiyuan Chen; Allison R. Scott; and Andrew C. Box; and Alejandro Sánchez Alvarado, PhD.

Taking a step back, “what this paper does is take a global look at what sorts of cells need to be in a signaling environment to stimulate stem cells to create new tissue and replace missing tissue,” Benham-Pyle reflects.

“It turns out that a number of genes that we characterized, for instance in the intestine, have also been implicated in immune evasion in the context of cancer, or in wound healing. A lot of the same mechanisms that stem cells use to avoid the immune system and to fuel proliferation and growth during regeneration may be the same mechanisms that are co-opted by tumors. By understanding what non-stem cell states and tissue types are helping to create that signaling environment, we might eventually find new targets for either stimulating healthy and normal wound healing in contexts where regenerative capacity is limited, or, limiting growth capacities of things that we don’t want to grow, like tumors.”

“Now that we have a map, we can go and figure out how the cells are talking to each other, what they’re doing, and how they’re doing it.”

The work was supported in part by the Stowers Institute for Medical Research, the Howard Hughes Medical Institute, the National Institute of General Medical Sciences of the National Institutes of Health (award R37GM057260 to A.S.A), the Jane Coffin Childs Memorial Fund Postdoctoral Fellowship (B.W.B.P), and a Howard Hughes Medical Institute Postdoctoral Fellowship (F.G.M). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

Lay Summary of Findings

The free-living planarian Schmidtea mediterranea (a type of flatworm) is capable of regenerating an entire body from a tiny portion of tissue. How it accomplishes this has largely been a mystery. In a report published September 2, 2021, in Nature Cell Biology, members from the lab of Alejandro Sánchez Alvarado, PhD, of the Stowers Institute for Medical Research, describe an atlas of cell identity and cellular behavior over time in worms that are healthy, beginning the process of regeneration, and completing regeneration.

The study, led by Blair Benham-Pyle, PhD, is the first to definitively show that whole-body regeneration involves transcriptional changes in cells from all three germ layers (muscle, epidermis, and intestine) of the body, and that tissue from areas distant from, as well as nearby to the site of injury, contribute to the process of regeneration.

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About the Stowers Institute for Medical Research 

Founded in 1994 through the generosity of Jim Stowers, founder of American Century Investments, and his wife, Virginia, the Stowers Institute for Medical Research is a non-profit, biomedical research organization with a focus on foundational research. Its mission is to expand our understanding of the secrets of life and improve life’s quality through innovative approaches to the causes, treatment, and prevention of diseases.

The Institute consists of sixteen independent research programs. Of the approximately 500 members, over 370 are scientific staff that includes principal investigators, technology center directors, postdoctoral scientists, graduate students, and technical support staff. Learn more about the Institute at www.stowers.org and about its graduate program at www.stowers.org/gradschool.