It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, March 04, 2021
How math can help us understand the human body
Graph theory helps biologists study homeostasis, researchers say
Healthy human bodies are good at regulating: Our temperatures remain around 98.6 degrees Fahrenheit, no matter how hot or cold the temperature around us. The sugar levels in our blood remain fairly constant, even when we down a glass of juice. We keep the right amount of calcium in our bones and out of the rest of our bodies.
We couldn't survive without that regulation, called homeostasis. And when the systems break down, the results can cause illness or, sometimes, death.
In presentations at the American Association for the Advancement of Science's annual meeting, researchers argued that mathematics can help explain and predict those breakdowns, potentially offering new ways of treating the systems to prevent or fix them when things go wrong. The meeting was held virtually earlier this year because of the COVID-19 pandemic.
Homeostasis "is a biological phenomenon and biological systems wouldn't work without it," said Marty Golubitsky, one of the presenters and a distinguished professor of natural and mathematical sciences at The Ohio State University. "And if you had detailed, accurate mathematical models, you could numerically explore those systems, find places where this control really happens, and then you could estimate how things go wrong and how you might be able to correct it."
Scientists have a good handle on the biological reasons why that regulation happens: Certain systems in our bodies have to remain constant in order to function and keep our bodies alive. The math behind it, though, is less certain.
But understanding homeostasis - including predicting changes to it and calculating ways to keep the body regulated despite breakdowns in the body's systems that manage those regulations - could be a way to provide targeted medical care to people who need it, said Janet Best, co-author of some of the research behind the presentations and professor of mathematics at Ohio State.
"This is part of precision medicine," said Best, who is also co-director of Ohio State's Mathematical Biosciences Institute. "People are different, and you need a model that can work on different people. And we think that's what we've developed here."
Researchers at the MBI and at other institutions who study how math and biology intersect have built models to explain how the body maintains homeostasis in a variety of systems. At the heart of those models is a graph, a mathematical concept that seeks to explain how objects relate to one another. (If you took algebra or geometry in high school, you likely learned some of the basics of graph theory.)
Golubitsky and Best said that graph theory can help explain and predict changes to homeostasis in the body. That explanation, they say, could be useful for biologists and others looking for ways to intervene when homeostasis breaks down. That breakdown causes a number of problems - too much glucose in a person's blood, for example, or not enough calcium in their bones.
The AAAS presentations focused both on a graph that models how the body regulates dopamine levels through homeostasis and how graph theory helps identify properties of graphs that can help predict homeostasis. Golubitsky and Best described how dopamine and the enzymes that break it down can be represented as a mathematical formula associated with a graph.
They showed that, by calculating changes in the nodes, it might be possible to calculate or predict changes in dopamine levels. That approach could be expanded to other systems, Golubitsky said, though future study is needed to know for sure. That study is already underway, he said.
"Homeostasis is an important enough area in biology that if mathematics can contribute anything, it's a success," he said.
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Independent music squashed out of streaming playlists and revenue
Bands and artists on independent record labels get less than their fair share of access to the most popular playlists on streaming platforms such as Spotify - argues a new paper from the University of East Anglia.
The paper, published today, looks at whether streaming platforms offer a level playing field for artists and record labels.
It finds that major labels have an unfair advantage when it comes to playlist access - and that they take the lion's share of subscription revenue as a result.
As a possible remedy, the research team suggests changing the payment system, so that royalties generated by individual listener subscriptions go direct to the labels, bands and artists they are listening to.
They also recommend more transparency in how playlists are created and how the algorithms behind music recommendations work.
Finally, they recommend greater transparency about contracts and say that major labels with financial stakes in streaming platforms should be forced to divest.
Not overhauling the system, they say, is likely stifle innovation and creativity in the long run - which will in turn impact both the industry and consumers.
Prof Peter Ormosi, from UEA's Norwich Business School and Centre for Competition Policy, said: "Music streaming has become the most important route to market recorded music, and this position is likely to strengthen in future.
"Music streaming platforms like Spotify pay the labels royalties that are calculated on a pro rata basis, as a proportion of the revenues associated with the streams of their content.
"We wanted to see how streaming platforms support or distort fair competition between different types of recorded music and their creators - whether they offer a level playing field for artists and labels.
"A level playing field is important not only for artists but also, over the longer term, for consumers. If competition is distorted it risks inhibiting innovation, variety and the prospects of upcoming and more niche artists.
"Creativity and innovation are vital for the music industry - if streaming platforms stifle this, it will be bad for the whole industry and consumers in the long run."
The team studied in detail how streaming platforms such as Spotify and Apple Music operate - including how streaming revenues are split between major and independent labels and artists, the role of playlists, and how some major labels also hold shares in streaming platforms.
Co-author Prof Amelia Fletcher, also from UEA's Norwich Business School and Centre for Competition Policy, said: "Playlists on music streaming platforms play a central role in disseminating music to consumers. As such, it is important for ensuring fair competition that independent artists have fair access to playlists.
"But our research suggests that independent label artists are getting less than their fair share of access to the most popular playlists.
"While the vast majority of playlists are curated by Spotify, the shares of the major labels' own proprietary playlists may exacerbate the situation.
"This disproportionately lesser access is likely to have a direct impact on revenues for independent labels and their artists as well as an indirect impact on the sustainability of this important segment of the market in the future.
Co-author Daniel Antal, founder of Reprex, a big data startup focusing on the music industry,said: "The impact of playlists on royalty payments is likely to be accentuated under a pro-rata royalty allocation system.
"We recommend that the payment system should be reformed by moving from the pro-rata payment system to a user-centric remuneration, where the royalties generated by an individual user's subscription is simply split between what they choose to listen to.
"We would also encourage greater transparency of contracts, once they are agreed, to help ensure fair treatment, or alternatively that competition authorities should allow industry-wide negotiation by labels, as is already carried out for performance and mechanical royalties on the composition side of the split.
"Finally, we note that some of the majors have residual equity stakes in Spotify. For example Universal holds a 3.5 per cent stake and Sony Music a 2.9 per cent stake, in Spotify. And Deezer is part-owned by Access Industries which in turn owns Warner Music Group.
"Requiring divestment of such stakes could also be helpful in ensuring that streaming platforms have the right incentives to ensure a level playing field."
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'Music streaming: is it a level playing field?' is published in the journal Competition Policy International.
Researchers discover that privacy-preserving tools leave private data anything but
BROOKLYN, New York, Wednesday, March 3, 2021 - Machine-learning (ML) systems are becoming pervasive not only in technologies affecting our day-to-day lives, but also in those observing them, including face expression recognition systems. Companies that make and use such widely deployed services rely on so-called privacy preservation tools that often use generative adversarial networks (GANs), typically produced by a third party to scrub images of individuals' identity. But how good are they?
Researchers at the NYU Tandon School of Engineering, who explored the machine-learning frameworks behind these tools, found that the answer is "not very." In the paper "Subverting Privacy-Preserving GANs: Hiding Secrets in Sanitized Images," presented last month at the 35th AAAI Conference on Artificial Intelligence, a team led by Siddharth Garg, Institute Associate Professor of electrical and computer engineering at NYU Tandon, explored whether private data could still be recovered from images that had been "sanitized" by such deep-learning discriminators as privacy protecting GANs (PP-GANs) and that had even passed empirical tests. The team, including lead author Kang Liu, a Ph.D. candidate, and Benjamin Tan, research assistant professor of electrical and computer engineering, found that PP-GAN designs can, in fact, be subverted to pass privacy checks, while still allowing secret information to be extracted from sanitized images.
Machine-learning-based privacy tools have broad applicability, potentially in any privacy sensitive domain, including removing location-relevant information from vehicular camera data, obfuscating the identity of a person who produced a handwriting sample, or removing barcodes from images. The design and training of GAN-based tools are outsourced to vendors because of the complexity involved.
"Many third-party tools for protecting the privacy of people who may show up on a surveillance or data-gathering camera use these PP-GANs to manipulate images," said Garg. "Versions of these systems are designed to sanitize images of faces and other sensitive data so that only application-critical information is retained. While our adversarial PP-GAN passed all existing privacy checks, we found that it actually hid secret data pertaining to the sensitive attributes, even allowing for reconstruction of the original private image."
The study provides background on PP-GANs and associated empirical privacy checks, formulates an attack scenario to ask if empirical privacy checks can be subverted, and outlines an approach for circumventing empirical privacy checks.
The team provides the first comprehensive security analysis of privacy-preserving GANs and demonstrate that existing privacy checks are inadequate to detect leakage of sensitive information. ?
Using a novel steganographic approach, they adversarially modify a state-of-the-art PP-GAN to hide a secret (the user ID), from purportedly sanitized face images. ?
They show that their proposed adversarial PP-GAN can successfully hide sensitive attributes in "sanitized" output images that pass privacy checks, with 100% secret recovery rate. ?
Noting that empirical metrics are dependent on discriminators' learning capacities and training budgets, Garg and his collaborators argue that such privacy checks lack the necessary rigor for guaranteeing privacy.
"From a practical standpoint, our results sound a note of caution against the use of data sanitization tools, and specifically PP-GANs, designed by third parties," explained Garg. "Our experimental results highlighted the insufficiency of existing DL-based privacy checks and the potential risks of using untrusted third-party PP-GAN tools."
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About the New York University Tandon School of Engineering
The NYU Tandon School of Engineering dates to 1854, the founding date for both the New York University School of Civil Engineering and Architecture and the Brooklyn Collegiate and Polytechnic Institute. A January 2014 merger created a comprehensive school of education and research in engineering and applied sciences as part of a global university, with close connections to engineering programs at NYU Abu Dhabi and NYU Shanghai. NYU Tandon is rooted in a vibrant tradition of entrepreneurship, intellectual curiosity, and innovative solutions to humanity's most pressing global challenges. Research at Tandon focuses on vital intersections between communications/IT, cybersecurity, and data science/AI/robotics systems and tools and critical areas of society that they influence, including emerging media, health, sustainability, and urban living. We believe diversity is integral to excellence, and are creating a vibrant, inclusive, and equitable environment for all of our students, faculty and staff. For more information, visit engineering.nyu.edu.
Nature: new compound for male contraceptive pill
Dr. Wei Yan discovered a natural compound that exhibits almost ideal male contraceptive effects in pre-clinical studies
IMAGE: DR. WEI YAN, INVESTIGATOR, THE LUNDQUIST INSTITUTE view more
CREDIT: THE LUNDQUIST INSTITUTE
Nature Communications Publishes Paper by Lundquist Institute Investigator Dr. Wei Yan and Colleagues on New Promising Compound for Male Contraceptive Pill
The Lundquist Institute researchers discovered a natural compound that exhibits almost ideal male contraceptive effects in pre-clinical studies
LOS ANGELES (March 3, 2021) -- In a new paper published by Nature Communications, The Lundquist Institute (TLI) Investigator Wei Yan, MD, PhD, and his research colleagues spell out an innovative strategy that has led to the discovery of a natural compound as a safe, effective and reversible male contraceptive agent in pre-clinical animal models. Despite tremendous efforts over the past decades, the progress in developing non-hormonal male contraceptives has been very limited.
The compound is triptonide, which can be either purified from a Chinese herb called Tripterygium Wilfordii Hook F, or produced through chemical synthesis. Single daily oral doses of triptonide induce altered sperm having minimal or no forward motility with close to 100% penetrance and consequently male infertility in 3-4 and 5-6 weeks. Once the treatment is stopped, the males become fertile again in ~4-6 weeks, and can produce healthy offspring. No discernable toxic effects were detected in either short- or long-term triptonide treatment. All of their data suggest that triptonide is a highly promising non-hormonal male contraceptive agent for men because it appears to meet all of the criteria for a viable contraceptive drug candidate, including bioavailability, efficacy, reversibility and safety. A battery of biochemical analyses suggest that triptonide targets one of the last steps during sperm assembly, leading to the production of altered sperm without vigorous motility required for fertilization.
"Thanks to decades of basic research, which inspired us to develop the idea that a compound that targets a protein critical for the last several steps of sperm assembly would lead to the production of nonfunctional sperm without causing severe depletion of testicular cells", said Dr. Yan. "We are very excited that the new idea worked and that this compound appears to be an ideal male contraceptive. Our results using non-injurious studies on lower primates suggest triptonide will be an effective treatment for human males as well. Hopefully, we will be able to start human clinical trials soon to make the non-hormonal male contraceptive a reality."
"Dr. Yan's discovery represents a major leap forward in the field", said Drs. Christina Wang and Ronald Swerdloff, who are TLI co-Principal Investigators helping lead NIH-supported advanced clinical trials on hormone-based birth control approaches. "The more contraceptive methods available, the better, as we will want a family of pharmaceutical products to safely and effectively meet the family planning needs of men and couples at different stages of their reproductive lives, with differing ethnic, cultural and religious backgrounds and economic means," emphasized Wang and Swerdloff.
About The Lundquist Institute: Research with reach
The Lundquist Institute is an engine of innovation with a global reach and a 69-year reputation of improving and saving lives. With its new medical research building, its state-of-the-art incubator, "BioLabs at The Lundquist," existing laboratory and support infrastructure, and the development of a new 15-acre business tech park, the Lundquist Institute serves as a hub for the Los Angeles area's burgeoning biotech scene. The research institute has over 100 principal investigators (PhDs, MDs, and MD/PhDs) working on more than 600 research studies, including therapies for numerous, and often fatal orphan diseases.
IMAGE: SPECIALISTS IN VIRAL AND GENETIC ANALYSIS, LED BY SWISS SCIENTISTS DR. EMMA HODCROFT AT THE UNIVERSITY OF BERN AND PROF. CHRISTOPHE DESSIMOZ AT UNIVERSITY OF LAUSANNE, ALONGSIDE DR. NICK GOLDMAN... view more
"What scientists have achieved in a year since the discovery of a brand-new virus is truly remarkable," says Emma Hodcroft from the Institute of Social and Preventive Medicine (ISPM) of the University of Bern, first author on the piece, "but the tools scientists are using to study how SARS-CoV-2 is transmitting and changing were never designed for the unique pressures - or volumes of data - of this pandemic."
SARS-CoV-2 is now one of the most sequenced pathogens of all time, with over 600,000 full-genome sequences having been generated since the pandemic began, and over 5,000 new sequences coming in from around the world every day. However, the analysis and visualization tools used today (including Nextstrain, co-developed by Prof. Richard Neher's group at the SIB and the University of Basel) were never designed to handle the volume and speed of sequences being generated today, or the scale of the involvement with public health response. "Across the world, genomic surveillance rests on the initiative of academic researchers to find essential answers. Public health decision making would benefit from a more sustainalble collaboration framework," says Christophe Dessimoz at SIB and University of Lausanne.
What an improved sequencing would enable
The genetic sequences from SARS-CoV-2 hold valuable information to implementing effective pandemic policies and staying ahead of the virus. Comparing how many mutations different samples share, for example, allows scientists to track the transmission of the virus - helping to identify super-spreading events and international spread. But at the moment it can be hard to combine this genetic information with other key variables - like who attended an event, and when symptoms appeared - which could help make these methods even more informative.
The 'R-number' has gone from a scientific concept to a household word in the last year - it measures the average number of people an infected person will transmit to. Here, sequences can help too, by helping to pick apart imported cases from local transmission. This allows for a more accurate estimate of Re, but needs high levels of sequencing and complex analyses, which are currently not widely implemented.
Finally, sequencing is the only way to identify and track the many mutations that arise in SARS-CoV-2. While mutations are a normal part of virus life, scientists need to know which are harmless variations and which could change the virus' transmissibility or clinical outcome. Combining sequences, lab work, and computational predictions could allow for a better understanding of mutational impacts, but there's little framework to help these different specialities work together. "The viral data - sequences and associated metadata- must be determined, gathered and harmonized thanks to stable infrastructures compatible with the principles of Open Data to facilitate peer-review by the community and their reuse", says Christophe Dessimoz at SIB and University of Lausanne, last author of the comment.
Benefits for Switzerland
"In Switzerland, the population could benefit from more systematic and representative sequencing, for example through better contract tracing, targeted isolation and quarantine of smaller regions, and guiding the closing and opening of schools based on the presence of certain variants", explains Emma Hodcroft. Harmonisation of health data practices is also a critical topic. Switzerland is already putting a lots of efforts at the national level through the Swiss Personalized Health Network (SPHN).
The researchers are convinced that Switzerland's potential in terms of expertise and infrastructure is just waiting to be tapped, to the benefit of public health. "The tools to enable research are there, and researchers have self-organized and taken the first step: to scale up and sustain these efforts to bring research and public health closer together, we rely on a sustainable public funding", says Christophe Dessimoz.
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Institute of Social and Preventive Medicine ISPM at the University of Bern
The Institute of Social and Preventive Medicine (ISPM) provides undergraduate and postgraduate education and carries out interdisciplinary research in the fields of social and behavioural health, clinical epidemiology and biostatistics, and international and environmental health. It also provides a wide range of postgraduate education to train students to become excellent public health researchers and to work as public health specialists. This year, the ISPM celebrates its 50th anniversary.
Swiss Institute of Bioinformatics
The SIB Swiss Institute of Bioinformatics is an internationally recognized non-profit organization, dedicated to biological and biomedical data science. Its data scientists are passionate about creating knowledge and solving complex questions in many fields, from biodiversity and evolution to medicine. They provide essential databases and software platforms as well as bioinformatics expertise and services to academic, clinical, and industry groups. SIB federates the Swiss bioinformatics community of some 800 scientists, encouraging collaboration and knowledge sharing.
The institute contributes to keeping Switzerland at the forefront of innovation by fostering progress in biological research and enhancing health.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
Lessons from Wuhan: What managers and employees need to know
As COVID-19 lockdowns and quarantines are lifted, businesses are now faced with the challenge of how to keep their employees who are returning to work motivated and engaged.
A study led by a University of Illinois Chicago researcher shows that both employees and managers have an important part to play in promoting employee engagement during the pandemic.
The research, published in the Journal of Applied Psychology, suggests employee engagement and performance are the highest when employees are mentally prepared for their return to work and their managers are strongly committed to employees' health and safety at work.
"Given the turmoil and distress during lockdowns and quarantines, employees may have trouble reconnecting with their work. We wanted to find out what factors could help employees effectively stay engaged at work upon return. This is an important topic because highly engaged employees tend to intrinsically enjoy their work and outperform others," says lead author Zhenyu Yuan, assistant professor of managerial studies in the UIC College of Business Administration.
In the study, Yuan and his co-authors surveyed more than 350 employees from the original epicenter of the COVID-19 pandemic -- Wuhan, China -- where many employees were returning to work after the strict city-wide lockdown was lifted.
According to the research, employees first need to mentally reconnect with their work.
"As employees are physically returning to work, they also need to be mentally prepared to reconnect," Yuan explained. "For example, employees are encouraged to spend some time reviewing work progress and set work priorities for upcoming tasks before coming back to work. This is similar to the warm-up before a workout. With some mental 'warm-up,' employees will find it easier to reconnect and re-engage at work."
Further, managers also have a critical role to play, Yuan added. With the continuous health threat of the coronavirus, employees can get easily overwhelmed and distracted in the workplace. Therefore, managers need to take concrete measures to promote workplace health and safety so that employees feel safe at work.
"Managers' commitment to safety can't be merely lip service," he said. "They should set a good example themselves by clearly communicating, enforcing, and promoting workplace health and safety protocols."
Importantly, the researchers found these two factors work synergistically.
"Engagement and performance were highest only when both conditions are met," Yuan said. "This reinforces the idea that managers can't simply expect their employees to be devoted to work without providing effective support for their health and safety."
Given that their study was based on data collected from Wuhan, China, Yuan cautioned about the applicability of their findings across different countries and regions.
"Depending on how the virus has spread and been managed in different places, other factors are also important to consider," he said. "But we think our key finding holds regardless of locations. That is, managers and employees are in this together -- they need to work together to promote engagement, workplace productivity, and safety. This will be critical as businesses and employees try to rebound from the economic toll of the current pandemic."
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Study co-authors include Zhuxin Ye, assistant professor at Huazhong University of Science and Technology; and Meng Zhong, a doctoral candidate in the UIC Department of Managerial Studies.
Neuroimaging reveals how ideology affects race perception
ITHACA, N.Y. - How might people's political ideology affect their perception of race?
Previous research by Amy Krosch, assistant professor of psychology in the College of Arts and Sciences, has shown that white people who identify themselves as political conservatives tend to have a lower threshold for seeing mixed-race Black and white faces as Black.
More often than liberals, Krosch found, white political conservatives show a form of social discrimination termed "hypodescent" - categorizing multiracial individuals as members of the "socially subordinate" racial group.
In new research published Feb. 22 in Philosophical Transactions of Royal Society B, Krosch used neuroimaging to show that this effect seems to be driven by white conservatives' greater sensitivity to the ambiguity of mixed-race faces rather than a sensitivity to the Blackness of faces; this sensitivity showed up in a neural region often associated with affective reactions.
Taken together, these study results suggest white political conservatives might overcategorize mixed-race faces as Black not because of an aversion to Blackness, but because of an affective reaction to racial mixing more generally, Krosch said. The study appears in a special issue about political neuroscience.
"We knew from our previous work that conservatives tend to categorize more mixed-race faces as their 'socially-subordinate' race, or according to hypodescent," Krosch said, "a principle closely related to notorious 'one-drop' rules, used to subjugate individuals with any nonwhite heritage by denying them full rights and liberties under the law from the earliest days of American slavery through the Civil Rights Era."
In the new study, Krosch said, she and the other researchers wanted to figure out why this is the case: "Specifically, we wanted to know if conservatives and liberals differ in the way they are literally seeing, thinking or feeling about mixed-race faces."
Mixed-race faces vary on at least two critical dimensions, Krosch wrote: "Do conservative and liberals differ in their sensitivity to the racial content or racial ambiguity of such faces? Such questions are difficult to separate in behavioral investigations but might be critical to understanding the link between ideology and hypodescent."
In the new study, the researchers used functional neuroimaging (fMRI) - a proxy for blood flow in regions of the brain - to examine the role of neural mediators of political ideology on discriminatory hypodescent regarding mixed-race faces.
Forty-one self-identified white participants self-reported political ideology on an 11-point scale before the neuroimaging. Members of this ideologically diverse group of individuals were presented with computer-generated face images that ranged from 100% white to 100% Black at 10% increments while neuroimaging captured brain activity.
"Of primary interest was a specific neural region - the insula - because of its relevance in independent investigations of ideology, race and ambiguity," Krosch wrote. The insula plays a key role in emotional processing, and the anterior insula is associated with processing ambiguity, so it might also be associated with political ideology and hypodescent, she wrote.
In the results, conservatives exhibited a lower threshold for seeing mixed-race faces as Black and this was related to their higher sensitivity to racial ambiguity in the anterior insula. Conservatives also made decisions faster than liberals. Together, these results indicate that conservatives might feel an aversion to racial ambiguity of any kind which causes them to resolve racial ambiguity "quickly and in the most culturally accessible or hierarchy-affirming way - that is, according to hypodescent," Krosch writes.
Notably, conservatives and liberals did not differ in their responses to ambiguity or face Blackness in brain regions related to lower-level visual processing or social cognition. "Rather than visually perceiving or thinking about mixed-race faces differently, conservatives might maintain a stricter boundary around whiteness (compared to liberals) because of the way they feel about racial ambiguity," Krosch wrote.
These results advance understanding of the role of political ideology in race categorization, Krosch wrote.
"They also help to explain how and why multiracial individuals are often categorized as members of their most subordinate racial group - a phenomenon that enhances their vulnerability to discrimination and exacerbates existing racial inequalities," Krosch wrote. "Given the myriad societal consequences of minority-group categorization and the large number of people who are potentially vulnerable to biased categorization, understanding the processes by which ideology reinforces the racial status quo is critically important."
Camera traps reveal newly discovered biodiversity relationship
Data scientists analyze photos from 15 tropical rainforests
IMAGE: AN ANALYSIS OF CAMERA TRAP DATA FROM 15 TROPICAL FORESTS FOUND UNIQUE TRAITS MAY BE MORE BENEFICIAL TO MAMMALS LIKE THE AFRICAN ELEPHANT IN AREAS WHERE PLANTS ARE HIGHLY PRODUCTIVE... view more
CREDIT: DANIEL GORCZYNSKI
HOUSTON - (March 3, 2021) - In one of the first studies of its kind, an analysis of camera-trap data from 15 wildlife preserves in tropical rainforests has revealed a previously unknown relationship between the biodiversity of mammals and the forests in which they live.
Tropical rainforests are home to half of the world's species, but with species going extinct at a rapid pace worldwide, it's difficult for conservationists to keep close tabs on the overall health of ecosystems, even in places where wildlife is protected. Researchers found that observational data from camera traps can help.
"In general, rainforest ecosystems are extremely diverse, and our study shows that mammal communities in rainforests can be predictably different, and these differences may be controlled, in part, by differences in plant productivity in forests," said Rice's Daniel Gorczynski, a graduate student in biosciences and corresponding author of a study featured on the cover of the Royal Society's flagship biological research journal, Proceedings of the Royal Society B.
Gorczynski and more than a dozen co-authors, including his Ph.D. adviser, Rice ecologist Lydia Beaudrot, analyzed camera-trap photos from the Tropical Ecology Assessment and Monitoring Network (TEAM), which uses motion-activated cameras to monitor species trends in tropical forests in Asia, Africa and South America.
Beaudrot, an assistant professor of biosciences, said the study's scientific contributions demonstrates the importance of having the same data collection replicated on the ground in forests all around the world.
"The TEAM data are an incredible resource for basic and applied ecology and conservation," she said. "Given the pace of tropical forest loss, it is more important now than ever to use standardized camera-trap data to understand environmental and anthropogenic effects on wildlife."
For each site, the researchers gathered data about all species of terrestrial mammals with an average body mass greater than 1 kilogram. All the mammal species studied at each site were treated as a single community, and data was compiled for communities with as many as 31 species and as few as five. The researchers also compiled the known functional traits for each species, such as body size, reproductive habits and diet. The combined functional traits of species in a community were used to calculate the community's "functional diversity," or the variety of roles in the forest's overall ecosystem that were filled by that community's species.
"We found that species with unique characteristics -- for example, species that are very large or eat unique foods -- are relatively more common in forests with high productivity," Gorczynski said, referring to the measure ecologists use to characterize the overall rate of plant growth within a forest. The research also showed that species with unique characteristics were less common at sites with low productivity.
"Higher productivity is thought to make rare resources, like certain food types that unique species often eat, more readily available, which unique species can capitalize on," he said. "And because they are unique, they don't have to compete as much with other species for rare resources, and they can persist at higher abundances."
The species that are considered unique vary by site, he said. Examples include elephants, tapirs and ground-dwelling monkeys.
Gorczynski said this relationship between mammal functional diversity and productivity had not been previously shown.
"Most studies of rainforest mammals rely on range maps, which don't give you an idea of how common different species are," he said. "We were able to find this relationship because we used camera trap observations. The observational data gives us an idea of how common different species are, which allows us to compare the relative abundances of species with different traits."
Study co-author Jorge Ahumada, a wildlife scientist at Conservation International, said the study also shows that destructive human activities, like deforestation, decrease the diversity of species' traits in protected areas.
"We found that in areas where local species extinctions have been documented due to significant deforestation or poaching, such as in Korup National Park in Cameroon, large carnivores like leopards and golden cats are the first to go," Ahumada said. "Without these apex predators, entire food chains can be thrown out of balance. Eventually, populations of smaller herbivores will skyrocket, forcing more competition for the same limited resources."
He said "simply counting the number of species in a tropical forest does not provide a full picture" of biodiversity or ecosystem health.
The researchers said more data science studies are needed to understand the ramifications of local species extinctions and address other fundamental questions in conservation, ecology and wildlife biology.
Additional co-authors include Chia Hsieh and Jadelys Tonos Luciano of Rice; Santiago Espinosa of both the Autonomous University of San Luis Potosà in Mexico and the Pontifical Catholic University of Ecuador; Steig Johnson of the University of Calgary in Canada; Francesco Rovero of both the University of Florence in Italy and the MUSE-Science Museum in Trento, Italy; Fernanda Santos of the Museu Paraense EmÃlio Goeldi in Brazil; Mahandry Hugues Andrianarisoa of Centre ValBio in Madagascar; Johanna Hurtado Astaiza of the Organization for Tropical Studies in Costa Rica; Patrick Jansen of both the Smithsonian Tropical Research Institute in Panama and Wageningen University in the Netherlands; Charles Kayijamahe of the International Gorilla Conservation Program in Rwanda; Marcela Guimara?es Moreira Lima of the Federal University of Pará in Brazil; and Julia Salvador of the Wildlife Conservation Society in Ecuador.
The research was funded by the Gordon and Betty Moore Foundation, HP, the Northrop Grumman Foundation and other donors.
TEAM data was provided by the TEAM Network, a collaboration between Conservation International, the Smithsonian Institute and the Wildlife Conservation Society.
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Links and resources:
The DOI of the Proceedings of the Royal Society B paper is: 10.1098/rspb.2020.2098
CAPTION: An analysis of camera trap data from 15 tropical forests found unique traits may be more beneficial to mammals like the African elephant in areas where plants are highly productive and generate large quantities of biomass. (Photo by Daniel Gorczynski)
CAPTION: Lydia Beaudrot (Photo by Jeff Fitlow/Rice University)
This release can be found online at news.rice.edu.
Follow Rice News and Media Relations via Twitter @RiceUNews.
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 3,978 undergraduates and 3,192 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.
Small-scale fisheries offer strategies for resilience in the face of climate change
STANFORD'S SCHOOL OF EARTH, ENERGY & ENVIRONMENTAL SCIENCES
Coastal communities at the forefront of climate change reveal valuable approaches to foster adaptability and resilience, according to a worldwide analysis of small-scale fisheries by Stanford University researchers.
Globally important for both livelihood and nourishment, small-scale fisheries employ about 90 percent of the world's fishers and provide half the fish for human consumption. Large-scale shocks -- like natural disasters, weather fluctuations, oil spills and market collapse -- can spell disaster, depending on the fisheries' ability to adapt to change. In an assessment of 22 small-scale fisheries that experienced stressors, researchers revealed that diversity and flexibility are among the most important adaptive capacity factors overall, while access to financial assets was not as important for individual households as it was at the community scale. The research was published Jan. 23 in the journal Climatic Change.
"The idea of assets not being essential at the household level is an empowering finding because we looked at a lot of places in developing nations without a lot of assets," said lead author Kristen Green, a PhD student in the Emmett Interdisciplinary Program in Environment and Resources (E-IPER) at Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth). "It shows we can invest in non-financial or non-asset-based adaptive mechanisms, and fishers can still adapt."
Focusing on response mechanisms
The researchers measured adaptive capacity using a new framework with three response pathways: adapt, react and cope. Adaptation is defined as proactive planning or taking collective action, reaction as an unplanned response, and coping as passive acceptance of consequences. The team of 11 study authors determined whether or not each fishery community or household had capacity in the areas of knowledge, assets, diversity and flexibility, governance and institutions, and natural capital.
"These adaptive capacity domains don't work in isolation -- it's the recipes or combinations that are important for successful adaptation," Green said.
While previous research has calculated a quantitative or numerical resilience score for different regions and sectors, the focus on community response is fairly new, according to senior author Larry Crowder, the Edward Ricketts Provostial Professor and professor of biology in Stanford's School of Humanities and Sciences.
"Millions of people are dependent on making a living in small-scale fisheries, and some of them are currently doing it better than others," said Crowder, who is also a senior fellow at the Stanford Woods Institute for the Environment. "If we can identify the features that allow communities and individuals to be better prepared for those perturbations -- in other words, to have an adaptive response -- then we can try to build that capacity in communities that don't have it."
In one case study in their analysis, a tropical island in Vanuatu exhibited flexibility when a cyclone disrupted fishery reefs, infrastructure and fisher livelihoods. Because the fishers had agency over management of the marine area, they were able to temporarily open a previously closed section to maintain food supply and income.
"Part of our findings run counter to the emerging conventional wisdom that making specialists of fisherman is a good thing," Crowder said. "Historically, these fishers were generalists, and our findings suggest they're more able to adapt to fluctuating circumstances if they can maintain that generalist fishing approach."
Incorporating diverse needs
The researchers found that diversity and flexibility were important at every scale, for both community and household adaptive capacity in responding to acute and chronic stressors -- for example, being able to diversify fishing portfolios or shift to other means of income. In addition to climate stressors, the researchers assessed responses to biological, economic, political and social changes, as well as environmental degradation and overfishing. The patterns that emerged from the study may be applied to adaptive capacity in other sectors, such as agriculture or manufacturing.
Using a broad "way of life" approach allowed the co-authors to consider what factors drive behavior, such as culture, heritage or spending time with their families -- not necessarily economics.
"From a Western perspective, sustainability would be a nice thing to have happen. But for people in these communities that are highly resource-dependent, it's not nice -- it's necessary," Crowder said. "Their future is potentially compromised if they and we don't help figure out how to make those lifestyles more sustainable in the long term."
The analysis revealed several examples of how Western-style management -- such as imposing fixed protection areas or maximizing one product that will make the most money -- doesn't always work for small-scale fisheries.
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Co-authors on the study include Jennifer Selgrath, Timothy Frawley, William Oestreich, Elizabeth Mansfield and Stephanie Green of the Hopkins Marine Station; and Jose Urteaga, Shannon Swanson, Francisca Santana and Josheena Naggea of E-IPER. Frawley is also affiliated with the Institute of Marine Sciences at the University of California, Santa Cruz; S. Green is also affiliated with the University of Alberta
Temperature and aridity fluctuations over the past century linked to flower color changes
Clemson researchers combined color descriptions from museum flower specimens dating back to 1895 with historic climate data to link changes in temperature and aridity with color change in the human-visible spectrum
IMAGE: CLEMSON UNIVERSITY GRADUATE STUDENT CIERRA SULLIVAN USED HERBARIUM SPECIMEN DATA IN HER RESEARCH LINKING TEMPERATURE AND ARIDITY CHANGES TO FLOWER COLOR CHANGES OVER THE PAST 124 YEARS. view more
CREDIT: CLEMSON UNIVERSITY COLLEGE OF SCIENCE
CLEMSON, South Carolina - Clemson University scientists have linked climatic fluctuations over the past one and a quarter-century with flower color changes.
Researchers combined descriptions of flower color from museum flower specimens dating back to 1895 with longitudinal- and latitudinal-specific climate data to link changes in temperature and aridity with color change in the human-visible spectrum (white to purple).
The study, which was published in the journal Proceedings of the Royal Society B, showed the change varied across taxa.
"Species experiencing larger increases in temperature tended to decline in pigmentation, but those experiencing larger increases in aridity tended to increase in pigmentation," said Cierra Sullivan, a graduate student in the College of Science's Department of Biological Sciences and lead author of the paper titled "The effects of climate change on floral anthocyanin polymorphisms."
Matthew Koski, an assistant professor of biological sciences, co-authored the paper.
Previous research by Koski and his team, including Sullivan, showed that the ultraviolet-absorbing pigmentation of flowers increased globally over the past 75 years in response to a rapidly degraded ozone layer. That study discussed how flower color changes could influence the behavior of pollinators, which have UV photoreceptors that enable them to detect patterns not visible to human eyes. This study discusses plant color change visible to humans.
"Although we see these changes in flower color, that doesn't inherently mean it's doomsday because the forest, plants and animals naturally respond to what's going on in their environment," Sullivan said. "Seeing changes is not necessarily bad, but it's something to which we should pay attention."
Researchers selected 12 species with reported floral color polymorphisms in North America, representing eight families and 10 genera.
Sullivan obtained herbarium specimen data from the Southeast Regional Network of Expertise and Collections (SRNEC), Consortium of Pacific Northwest Herbaria, Consortium of California Herbaria and the Consortium of Northeastern Herbaria. She also checked Clemson University Herbarium's physical collection for specimens not already represented in SERNEC.
After researchers retrieved the date of specimen collection and latitudinal and longitudinal coordinates, they obtained historical bioclimatic data from the year and month that the plant was collected. That data included monthly precipitation, minimum, maximum and mean temperature, minimum and maximum vapor pressure deficit (VPD), and dew point temperature. Vapor pressure deficit is the difference between how much moisture is in the air and the amount of moisture that can be held when the air is saturated. It has implications for drought stress in plants -- higher VPD means more water loss from plants.
Researchers were able to get complete data sets for 1,944 herbarium specimens.
They found variation among the 12 species. Some increased in pigmentation, while others declined in color over the past century.
"It was all tightly linked to how much climatic variation they experienced over time across their range," Koski said.
Two of the species that tended to get lighter in pigmentation are found in the western parts of North America that experienced more dramatic temperature changes than the species in the eastern United States, which had more moderate temperature increases.
"This study documents that flower color that is visually more obvious to humans is also responding to global change but is responding to different factors such as temperature and drought," Koski said.
He said such flower color changes are likely to affect plant-pollinator and plant-herbivore interactions and warrant further study.
Continued research will help give insight to how species will respond to the various aspects of climate change and which species are the most vulnerable to future climate projections," he said.
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This research was supported by the National Science Foundation Division of Environmental Biology Grant 174590 and Clemson University. The content is solely the responsibility of the authors and does not necessarily represent the views of the funders.
