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)
Wednesday, July 15, 2020
Robot jaws shows medicated chewing gum could be the future
UNIVERSITY OF BRISTOL
IMAGE: A CLOSE UP OF THE HUMANOID CHEWING ROBOT. view more
CREDIT: DR KAZEM ALEMZADEH, UNIVERSITY OF BRISTOL
Medicated chewing gum has been recognised as a new advanced drug delivery method but currently there is no gold standard for testing drug release from chewing gum in vitro. New research has shown a chewing robot with built-in humanoid jaws could provide opportunities for pharmaceutical companies to develop medicated chewing gum.
The aim of the University of Bristol study, published in IEEE Transactions on Biomedical Engineering, was to confirm whether a humanoid chewing robot could assess medicated chewing gum. The robot is capable of closely replicating the human chewing motion in a closed environment. It features artificial saliva and allows the release of xylitol the gum to be measured.
The study wanted to compare the amount of xylitol remaining in the gum between the chewing robot and human participants. The research team also wanted to assess the amount of xylitol released from chewing the gum.
The researchers found the chewing robot demonstrated a similar release rate of xylitol as human participants. The greatest release of xylitol occurred during the first five minutes of chewing and after 20 minutes of chewing only a low amount of xylitol remained in the gum bolus, irrespective of the chewing method used.
Saliva and artificial saliva solutions respectively were collected after five, ten, 15 and 20 minutes of continuous chewing and the amount of xylitol released from the chewing gum established.
Dr Kazem Alemzadeh, Senior Lecturer in the Department of Mechanical Engineering, who led the research, said: "Bioengineering has been used to create an artificial oral environment that closely mimics that found in humans.
"Our research has shown the chewing robot gives pharmaceutical companies the opportunity to investigate medicated chewing gum, with reduced patient exposure and lower costs using this new method."
Nicola West, Professor in Restorative Dentistry in the Bristol Dental School and co-author, added: "The most convenient drug administration route to patients is through oral delivery methods. This research, utilising a novel humanoid artificial oral environment, has the potential to revolutionise investigation into oral drug release and delivery."
VIDEO GAMES IMPACT GAMBLERS NOT SHOOTERS
Links between video games and gambling run deeper than previously thought, study reveals
A range of video game practices have potentially dangerous links to problem gambling, a study has revealed.
UNIVERSITY OF YORK
A range of video game practices have potentially dangerous links to problem gambling, a study has revealed.
Building on previous research by the same author, which exposed a link between problem gambling and video game loot boxes, the new study suggests that a number of other practices in video games, such as token wagering, real-money gaming, and social casino spending, are also significantly linked to problem gambling.
The research provides evidence that players who engage in these practices are also more likely to suffer from disordered gaming - a condition where persistent and repeated engagement with video games causes an individual significant impairment or distress.
Author of the study, Dr David Zendle from the Department of Computer Science at the University of York, said: "These findings suggest that the relationship between gaming and problem gambling is more complex than many people think."
"When we go beyond loot boxes, we can see that there are multiple novel practices in gaming that incorporate elements of gambling. All of them are linked to problem gambling, and all seem prevalent. This may pose an important public health risk. Further research is urgently needed"
For the study, a group of just under 1,100 participants were quota-sampled to represent the UK population in terms of age, gender, and ethnicity. They were then asked about their gaming and gambling habits.
The study revealed that a significant proportion (18.5%) of the participants had engaged in some behaviour that related to both gaming and gambling, such as playing a social casino game or spending money on a loot box.
Dr Zendle added: "There are currently loopholes that mean some gambling related elements of video games avoid regulation. For example social casinos are 'video games' that are basically a simulation of gambling: you can spend real money in them, and the only thing that stops them being regulated as proper gambling is that winnings cannot be converted into cash.
"We need to have regulations in place that address all of the similarities between gambling and video games. Loot boxes aren't the only element of video games that overlaps with gambling: They're just a tiny symptom of this broader convergence"
Last year, University of York academics, including Dr David Zendle, contributed to a House of Commons select committee inquiry whose report called for video game loot boxes to be regulated under gambling law and for their sale to children to be banned. Dr Zendle also provided key evidence to the recent House of Lords select committee inquiry that likewise produced a report recommending the regulation of loot boxes as gambling.
###
'Beyond loot boxes: a variety of gambling-like practices in video games are linked to both problem gambling and disordered gaming' is published in the journal PeerJ.
Particulate plutonium released from the Fukushima Daiichi meltdowns
New research strongly suggests that the nano-scale heterogeneity that is common in normal nuclear fuels is still present in the fuel debris that remains inside the Fukushima's damaged reactors.
UNIVERSITY OF HELSINKI
IMAGE: (A)ELECTRON IMAGING OF A CSMP WITH ELEMENTAL MAPS. (B) SYNCHROTRON MICRO-FOCUS X-RAY FLUORESCENCE (ΜXRF) ELEMENTAL MAPS. (C) IMAGE OF URANIUM DIOXIDE INCLUSION IN THE CSMP. (D) URANIUM L3-EDGE X-RAY ABSORPTION... view more
CREDIT: KYUSHU UNIVERSITY
Small amounts of plutonium (Pu) were released from the damaged Fukushima Daiichi Nuclear Power Plant (FDNPP) reactors into the environment during the site's 2011 nuclear disaster. However, the physical, chemical, and isotopic form of the released Pu has remained unknown.
Now, recent work published in the journal Science of the Total Environment has shown that Pu was included inside cesium-rich microparticles (CsMPs) that were emitted from the site. CsMPs are microscopic radioactive particles that formed inside the Fukushima reactors when the melting nuclear fuel interacted with the reactor's structural concrete. Due to loss of containment in the reactors, the particles were released into the atmosphere; many were then deposited across Japan.
Studies have shown that the CsMPs are incredibly radioactive and that they are primarily composed of glass (with silica from the concrete) and radio-cesium (a volatile fission product formed in the reactors). Whilst the environmental impact and distribution of the CsMPs is still an active subject of debate, learning about the chemical composition of the CsMPs has been shown to offer a much-needed insight into the nature and extent of the FDNPP meltdowns.
The study published in Science of the Total Environment, involving scientists from Japan, Finland, France, Switzerland, the UK, and USA, was led by Dr. Satoshi Utsunomiya and graduate student Eitaro Kurihara (Department of Chemistry, Kyushu University). The team used a combination of advanced analytical techniques (synchrotron-based micro-X-ray analysis, secondary ion mass spectrometry, and high-resolution transmission electron microscopy) to find and characterize the Pu that was present in the CsMP samples.
The researchers initially discovered incredibly small uranium-dioxide inclusions, of less than 10 nanometers in diameter, inside the CsMPs; this indicated possible inclusion of nuclear fuel inside the particles. Detailed analysis then revealed, for the first-time, that Pu-oxide concentrates were associated with the uranium, and that the isotopic composition of the U and Pu matched that calculated for the FDNPP irradiated fuel inventory.
Dr Utsunomiya stated "these results strongly suggest that the nano-scale heterogeneity that is common in normal nuclear fuels is still present in the fuel debris that remains inside the site's damaged reactors. This is important information as it tells us about the extent / severity of the melt-down. Further, this is important information for the eventual decommissioning of the damaged reactors and the long-term management of their wastes."
With regards environmental impact, Dr Utsunomiya states "that as we already know that the CsMPs were distributed over a wide region in Japan (up to 230 km from the FDNPP), small amounts of Pu were likely dispersed in the same way."
Professor Gareth Law, a co-author on the paper from the University of Helsinki, indicated that the team "will continue to characterize and experiment with the CsMPs, in an effort to better understand their long-term behavior and environmental impact. It is clear that CsMPs are an important vector of radioactive contamination from nuclear accidents."
Professor Bernd Grambow, a co-author from Nantes/France, states that "while the Pu released from the damaged reactors is low compared to that of Cs; the investigation provides crucial information for studying the associated health impact."
Professor Rod Ewing at Stanford University emphasized that "the study used an extraordinary array of analytical techniques in order to complete the description of the particles at the atomic-scale. This is the type of information required to describe the mobility of plutonium in the environment."
Utsunomiya concluded "It took a long time to publish results on particulate Pu from Fukushima. I would like to emphasize that this is a great achievement of international collaboration. It's been almost ten years since the nuclear disaster at Fukushima," he continued "but research on Fukushima's environmental impact and its decommissioning are a long way from being over."
###
NOTE: Integration of the state-of-the-art analytical techniques was accomplished through a world-wide international network that included Kyushu University, University of Tsukuba, Tokyo Institute of Technology, National Institute of Polar Research, University of Helsinki, Paul Scherrer Institute, Diamond Light Source, SUBATECH (IMT Atlantique, CNRS, University of Nantes), and Stanford University.
Additional information:
Satoshi Utsunomiya, Associate Professor Department of Chemistry, Kyushu University, Japan Tel: +81-92-802-4168 Fax: +81-92-802-4168 E-mail: utsunomiya.satoshi.998@m..kyushu-u.ac.jp
Gareth Law, Professor Department of Chemistry, Radiochemistry Unit, University of Helsinki Tel: +358-50-55-60920 E-mail: Gareth.law@helsinki.fi
Drones and artificial intelligence show promise for conservation of farmland bird nests
UNIVERSITY OF HELSINKI
Farmland bird species are declining over most of Europe. Birds breeding on the ground, are particularly vulnerable because they are exposed to mechanical operations, like ploughing and sowing, which take place in spring and often accidentally destroy nests.
Locating nests on the ground is challenging for the human eye, and highly time-consuming
Researchers flew a drone carrying a thermal camera over agricultural fields to record images. These were then fed to an artificial intelligence algorithm capable of accurately identifying nests, a first step to aid their protection. Researchers tested the system in Southern Finland near University of Helsinki's Lammi Biological Station, using wild nests with eggs of the Lapwing Vanellus vanellus.
"We have been involved in conservation of ground-nesting farmland birds for years, and realized how difficult it is to locate nests on the ground. At least at high latitudes, the temperature of these nests is typically higher than that of the surrounding environment. Hence, we thought that thermal cameras could assist. A small pilot study indicated that thermal vision is hampered by vegetation and objects on the ground. Therefore to make this an efficient system, we thought that the camera could be flown using a drone, and artificial intelligence could help to analyse the resulting thermal images. We show that this works. However, the system performed best under cloudy and cold conditions, and on even grounds," says Andrea Santangeli, an Academy of Finland fellow at the Finnish Museum of Natural History Luomus, University of Helsinki.
Drone technology becoming rapidly popular in conservation
It is possible to map in near real-time the spread of diseases on crops in agricultural areas using drones with various sensors. The latter is an integral part of precision agriculture, a new way of crop production that makes large use of drone technology to monitor crops and maximize production efficiency.
Studies like this one can help pave the way to integrate bird nest detection within the drone borne sensors used in precision agriculture, and automate a system for saving those nests.
"The conservation community must be ready to embrace technology and work across disciplines and sectors in order to seek efficient solutions. This is already happening, with drone technology becoming rapidly popular in conservation. A next and most challenging step will be to test our system in different environments and with different species. Our auspice is that this system will be, one day, fully integrated into agricultural practices, so that detecting and saving nests from mechanical destruction will become a fully automated part of food production," says Andrea Santangeli.
The catastrophic effects of global environmental degradation, health deterioration and diminishing energy resources are demanding remedy measures aimed at environmental conservation, health interventions and harnessing of the abundant and renewable energy resources. Consequently, sensors and renewable energy harnessing systems have emerged as worthwhile solutions to the existent challenges. However, conventional sensors and renewable energy harnessing systems have presented diminished efficiency and performance to be improved. Therefore, current research trends are focusing on improving the efficiency and performance of these systems.
For centuries, nature has availed an unlimited cache of evolved biological species with improved energy harnessing capabilities and heightened responses to external stimuli, including temperature, pH, humidity and chemical molecules. Specifically, butterfly wings have gained research and aesthetic popularity for their vivid coloring, architypes of unique micro/nanostructures, sensitivity and effective responses to stimuli. While insect enthusiasts marvel at the beautiful wing coloration and patterning, researchers have determined that the vivid coloration and wing properties result from the structures and pigments found in the wing scales. The huge variety of beautifully colored wings has led researchers to classify the various unique wing scale architectures. Equally, researchers have made attempts to mimic the wing properties in fabrication of various manmade functional materials and systems, such as sensors and energy harnessing applications.
In the overview published in National Science Review, researchers in the State Key Laboratory of Metal Matrix Composites at Shanghai Jiao Tong University, Shanghai, China present the recent research progress in sensor and energy applications inspired by butterfly wings. In their review, Zhang W. and co-workers highlight the genesis of wing scale development and the subsequent formation of wing scale architectures. They describe the general appearance of the wing scale architectures as having three distinct regions namely, the highly convoluted upper lamina, flat and featureless lower lamina and pillar-like connection of the two layers called trabeculae. In addition, the authors discuss the most recent wing structure classification based on variations in specialized regions of the architectures. These wing scale architecture variations influence wing coloration among other properties, including porosity, surface area and responses to stimuli.
Recently, researchers have worked on a variety of sensor and energy systems with the aim of mimicking the properties of natural species into manmade functional systems. This published review has focused on the progress achieved in recent research towards the fabrication of sensor and energy systems inspired by butterfly wings. By employing the different properties of butterfly wings, featured researches have successfully fabricated thermal, medical and vapor sensors, anti-counterfeit security devices, photocatalysts, photovoltaic systems, triboelectric nanogenerators and energy storage systems. Comparatively, these featured systems have demonstrated competitive efficiency and performance to similar systems inspired by other natural species.
Unfortunately, more research is still necessary to achieve optimal replication of natural properties onto manmade functional systems. As a result, authors suggest that the application scope should extend to photothermal imaging and therapy in cancer treatment and management. The good performance recorded by medical sensors for health monitoring and photothermal capabilities of butterfly wing inspired materials will generate sufficient mechanism for the detection, imaging, therapy and monitoring of terminal diseases. Similarly, photothermal materials inspired by butterfly wings can gain interest in the emerging stealth technologies research for modern-day warfare and scientific research technologies, such as rockets. Lastly, butterfly wings have exhibited numerous and diverse properties that enable them effectively respond to external stimuli. Research should envision tapping onto these characteristics in fabrication of functional systems with multiple responses and high efficiencies. This should be a real break-through in attaining next generation applications that optimize the properties of natural species and meet the global energy shortages, environmental degradation and deteriorating health conditions.
###
This research received funding from the Key Program for International S&T Cooperation Program of China, National Natural Science Foundation of China, Shanghai Science and Technology Committee and National Key Research and Development Program.
See the article:
Maurice I. Osotsi, Wang Zhang, Imran Zada, Jiajun Gu, Qinglei Liu, Di Zhang
Butterfly wing architectures inspire sensor and energy applications
The National Science Review is the first comprehensive scholarly journal released in English in China that is aimed at linking the country's rapidly advancing community of scientists with the global frontiers of science and technology. The journal also aims to shine a worldwide spotlight on scientific research advances across China.
Towards prosperous public goods with freedom of choice
TOKYO INSTITUTE OF TECHNOLOGY
IMAGE: WITHOUT A POSSIBILITY TO PRIORITIZE THEIR CONTRIBUTIONS (LEFT), SAY, BETWEEN A LOCAL PARK, A LIBRARY, OR AN ENVIRONMENTAL INITIATIVE, PEOPLE ARE LESS LIKELY TO PARTICIPATE IN PUBLIC-GOODS PROVISION. LOW PARTICIPATION... view more
CREDIT: TOKYO TECH
From climate and biodiversity to public health and law enforcement, public goods benefit all. They are produced or maintained through widespread participation in public-goods provision that is vulnerable to low participation rates. Avoiding this vulnerability has spurred a continuing search for better ways to promote participation.
Now, a study by an international group of researches shows that the ability to freely choose preferred public goods adds to their value by increasing participation rates. The findings offer surprising insights into human decision making, while also suggesting that societies may profit from bottom-up approaches to public-goods provision.
Decades of experiments on human behavior and public goods games have consistently confirmed that initial participation rates hover around 50%, but then decrease due to free riding (the act of piggybacking on the goodwill of others). Recent theoretical research suggests that social networks are instrumental in offsetting free riding but so far, large-scale experiments have failed to support these theoretical predictions.
To investigate factors affecting public-goods provision, a research team coordinated by Marko Jusup from Tokyo Institute of Technology (Tokyo Tech) in Japan and Zhen Wang from Northwestern Polytechnical University in China conducted a social-dilemma experiment designed specifically to reveal what drives participation rates. Is it global characteristics of social networks or local circumstances of each individual?
The team organized a game experiment played by 596 students who were equally distributed across three social-network configurations and two experimental conditions. Under control conditions, players could only decide whether to participate in public goods provision or not. A decision to participate implied contributing one unit of wealth to each public good within their reach. The total contribution would then be multiplied by an interest rate and divided equally not only between actual contributors, but also free riders who could have contributed, but chose not to. Free riders could thus piggyback on the effort of contributors to gain benefits without sharing costs. Players under treatment conditions could additionally decide how much to contribute to each of the public goods within their reach.
A player with access to five different public goods would, by opting to participate under control conditions, contribute one unit of wealth to each of the public goods for a total contribution of five units. The same player under treatment conditions would also contribute a total of five units of wealth, but with a caveat that how much goes to each of the five public goods is subject to free will.
The study found that local circumstances are more important than the global characteristics of social networks. Changing the network configuration does not appear to affect player decisions in any significant way, whereas letting players distribute their wealth freely increases participation in public goods provision, motivates better provisioning, and thus adds value to public goods.
Remarkably, treatment conditions jump-started participation from the very beginning to form a cooperative milieu that is independent of social-network characteristics. Jusup comments: "This is surprising! We expected initial participation to be similar under both control and treatment conditions. Only later in the game did we expect gradual learning and optimization from players who could choose freely. We observed that increased participation in public-goods provision happens from the very first round of the game, as if the players could feel that extra freedoms weaken the underlying dilemma of whether to participate or not. Over time, more participation leads to more wealth, generating something akin to a free lunch for players under treatment conditions."
The study identified three behavioral types that account for the results: prosocial, antisocial, and conditional cooperators. Prosocial players participate almost unconditionally, antisocial players mostly forgo participation, and conditional cooperators refuse participation when there are no other participators around. Notably, freedom of choice seems to foster conditional cooperation, as evidenced by the fact that conditional cooperators are mostly absent under control conditions but predominate under treatment conditions. This occurs because in the latter case, players receive much clearer signals from their surroundings, and can then better gauge the overall cooperativeness of their neighbors.
There are many interesting implications for socio-economic settings. "Policymakers, for instance, could facilitate raising residential taxes by offering a portfolio of public goods for taxpayers to choose from," write the researchers in their study published in Proceedings of the National Academy of Sciences.
"And by doing so, voters could decouple long-term, life-improving, public-goods projects from the whims and fancies of political election cycles," adds Ivan Romi?, a co-author of the study. "Going beyond the politics, private companies might be able to motivate customers to pay premium product prices if the premium could be directed toward a public good of customers' choosing, thus stepping up the corporate social responsibility while remaining profitable."
###
Tuesday, July 14, 2020
Back to the future: new study could lead to bumper crops
AUSTRALIAN NATIONAL UNIVERSITY
IMAGE: USING A CHLOROPLAST SYNBIO APPROACH THE RESEARCHERS DECIPHERED HOW THE SMALL SUBUNIT INFLUENCES POTATO RUBISCO CATALYSIS. view more
CREDIT: ELENA MARTIN-AVILA, ET AL. (2020).
Research led by scientists at The Australian National University (ANU) could lead to major improvements in crop production.
The study shows a new way to help study and ramp up photosynthesis. The breakthrough is based on revisiting an original, billion-year-old strategy in plants.
It looks specifically at rubisco activity - a crucial part of the process according to co-author Professor Spencer Whitney from the ARC Centre of Excellence for Translational Photosynthesis at ANU.
"Rubisco is an enzyme involved in the first step of carbon fixation - it starts the conversion of carbon dioxide into plant sugars," he said.
"But compared to other enzymes, rubisco is considered a slow, inefficient catalyst.
"Many enzymes can process hundreds to thousands of molecules per second, but rubisco can only get through two to five cycles per second.
"For this reason, it's long been recognised as a good target for improving photosynthesis -- it's a puzzle scientists have been looking at for decades."
In plants rubisco is made up of 16 proteins - eight large and eight small subunits. Until now scientists have only been able to tinker with one subunit at a time.
"We've now turned back the clock a billion years to rectify this limitation," Professor Whitney said.
"By reapplying the genome design of the bacterial ancestors of chloroplasts we can now play around with all the components of rubisco simultaneously.
"This is crucial. To ramp up its activity you have to make changes to all the components."
It could mean big gains for canola and potato crop in particular.
"We know we can already tinker with rubisco activity in these crops, so it's a great place to start," Professor Whitney said.
"This is the just the first step - this technology could eventually deliver something much bigger in the not so distant future."
###
The research has been published in the journal Plant Cell.
This research has been funded by the Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis (CoETP), led by The Australian National University, and which aims to improve the process of photosynthesis to increase the production of major food crops such as sorghum, wheat and rice.
Pesticide mixtures a bigger problem than previously thought
UNIVERSITY OF QUEENSLAND
IMAGE: AN AERIAL SHOT OF THE GREAT BARRIER REEF. view more
CREDIT: THE UNIVERSITY OF QUEENSLAND
New research led by The University of Queensland has provided the first comprehensive analysis of pesticide mixtures in creeks and rivers discharging to the Great Barrier Reef.
UQ's School of Earth and Environmental Sciences researcher Associate Professor Michael Warne conducted the study with the Queensland Department of Environment and Science, and analysed 2600 water samples from 15 waterways that discharge into the Great Barrier Reef lagoon over a four-year period.
"While I knew many water samples would contain mixtures, I was shocked to find that essentially every sample contained mixtures of pesticides," Dr Warne said.
"We found 99.8 per cent of the samples contained pesticide mixtures with up to 20 pesticides in any single water sample.
"The issue with having mixtures of pesticides is that as the number of pesticides increases the impact to aquatic ecosystems generally increases.
"This work strongly supports the inclusion of the pesticide reduction target in the Reef 2050 Water Quality Improvement Plan which aims to protect at least 99 per cent of aquatic organisms at the mouths of rivers from the adverse effects of all pesticides."
Dr Warne said the best way to address the problem of pesticides and pesticide mixtures in run-off was to work with land managers, share information and help them to improve their pesticide management practices.
"We are doing just that with other partners including Farmacist, James Cook University and the Department of Environment and Science through Project Bluewater which is funded by the Great Barrier Reef Foundation," he said.
"This project is working with 70 sugar cane farmers in the Barratta Creek and Plane River catchments to improve their pesticide management and application, upgrade equipment, reduce pesticide use and switch to using lower risk pesticides.
"We have found the farmers involved to be very eager to engage with the science - they have embraced the challenge and are making significant steps toward improvement.
"We are looking to expand this project to include considerably more farmers in more catchments and make more rapid progress in reducing pesticide losses to waterways.
"There is always hope, but this study reveals the pesticide situation is more complex than we previously realised."
###
The research was published in the journal Environmental Pollution (DOI: 10.1016/j.envpol.2020.114088).
Predation by Caspian terns on young steelhead means fewer return as adults
OREGON STATE UNIVERSITY
IMAGE: CASPIAN TERN WITH SMOLT (PHOTO BY DAN ROBY OSU COLLEGE OF AGRICULTURAL SCIENCES) view more
CREDIT: (PHOTO BY DAN ROBY OSU COLLEGE OF AGRICULTURAL SCIENCES)
CORVALLIS, Ore. - Caspian terns feeding on young fish have a significant impact on runs of steelhead in the Columbia River, research by Oregon State University suggests.
Through detailed analysis of steelhead survival and Caspian tern predation rates, the researchers found that the birds are not only preying on fish that would perish for some other reason, but are adding to the annual death toll by eating steelhead smolts that would have survived without tern pressure.
In scientific terms, the findings indicate that the terns are having an "additive" effect on prey mortality rather than a "compensatory" one.
The study was published in Ecological Applications.
In the Columbia Basin, 13 of 20 populations of anadromous salmon and steelhead are listed as threatened or endangered under the Endangered Species Act. Caspian terns, a protected migratory bird species native to the region, have been the object of predator management in the Columbia Basin in an effort to protect smolts, especially steelhead smolts, from being eaten before they can swim downstream to the ocean.
The largest breeding colony of Caspian terns in the world was formerly on a small island in the lower Columbia River estuary between Oregon and Washington. It hosted more than 10,000 breeding pairs in 2008, just prior to implementation of nonlethal management to reduce colony size to between 3,125 and 4,375 breeding pairs.
"There has been little research, however, into whether reduced predation actually results in greater overall salmonid survival, either at the smolt stage, where the predation is taking place, or across the lifetime of the fish," said Oregon State's Dan Roby, professor emeritus in the Department of Fisheries and Wildlife of the College of Agricultural Sciences. "Without clear evidence that reduced predation means greater survival to adulthood, management to reduce predator impacts would be a waste of time and resources."
To tackle the question, Roby and collaborators at Real Time Research, Inc., of Bend and the University of Washington looked at 11 years' worth of mark-recapture-recovery data for almost 80,000 steelhead trout smolts from the Upper Columbia population that were tagged and released to continue their out-migration to the ocean.
After release, the tagged fish were exposed to predation throughout multiple stretches of river on their journey toward the Pacific. The tag-recovery data made possible estimates of the weekly probability of steelhead survival, mortality from being eaten by birds and death from other causes.
"This approach allowed us to directly measure the connection between smolt survival and tern predation," Roby said.
Estimates of tern predation on steelhead were substantial for most of the years studied, he said. And increases in tern predation probabilities were connected with statistically significant decreases in steelhead survival for all of the years evaluated and both of the fish life stages studied: smolt out-migration and smolt-to-adult returns.
"Our results provide the first evidence that predation by Caspian terns may have been a super additive source of mortality during the smolt stage and a partially additive source in the smolt-to-adult life stage," Roby said. "A persistent pattern was clear: For each additional 10 steelhead smolts successfully consumed by Caspian terns, about 14 fewer smolts from each cohort survived out-migration."
Another pattern: On average, for every 10 steelhead smolts eaten by terns, one fewer individual from each cohort returned to the Columbia Basin as an adult.
"Our model shows that mortality from tern predation was primarily additive and therefore has a credible, significant impact on prey survival," Roby said. "Predator-prey models need to consider additive effects of predation across life stages to avoid exaggerating potential benefits from management actions aimed at reducing predator populations to enhance prey populations. The primary value of the study is by analyzing the true effects of natural predators on populations of their prey, and thereby assessing the conservation value to prey of managing predators."
Roby notes that the study by OSU, Real Time Research, and the University of Washington contradicts recently published research by scientists with the U.S. Fish and Wildlife Service and the Fish Passage Center, who found that steelhead mortality due to tern predation is compensatory.
That paper, in the Journal of Wildlife Management, suggests that "management efforts to reduce the abundance of the [tern] colonies are unlikely to improve the survival or conservation status of steelhead."
###
Collaborating with Roby were corresponding author Quinn Payton, who has a doctoral degree from OSU, and others from Real Time Research, and Nathan Hostetter of the University of Washington.
The Public Utility District No. 2 of Grant County, Washington, the Bonneville Power Administration and the U.S. Army Corps of Engineers funded the research.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news
OUR UBIQUITOUS NATIONAL BIRD
Invasive alien species may soon cause dramatic global biodiversity loss
Experts identify future tipping point due to rapid spread of non-native plants and animals
UK CENTRE FOR ECOLOGY & HYDROLOGY
IMAGE: CANADA GEESE ARE NOW WELL ESTABLISHED IN EUROPE, POSING A SERIOUS THREAT TO BIODIVERSITY. THEY ALSO DAMAGE FARMLAND AND HAVE BEEN INVOLVED IN A NUMBER OF BIRD STRIKES. view more
CREDIT: PHOTO: TOM KOERNER/USFWS (CC BY 2.0) HTTPS://FLIC.KR/P/HRBQXQ
An increase of 20 to 30 per cent of invasive non-native (alien) species would lead to dramatic future biodiversity loss worldwide. This is the conclusion of a study by an international team of researchers led by Franz Essl and Bernd Lenzner from the University of Vienna. It has been published in the journal Global Change Biology.
Human activities intentionally and unintentionally introduce more and more plant and animal species to new regions of the world - for example, via commodity transport or tourism.
Some of these alien species have negative consequences for biodiversity and humans well-being, for example by displacing native species or transmitting diseases. However, while we have relatively good information on the historical spread of alien species, there is still little knowledge about their future development.
"At the moment it is not yet possible to generate precise predictions based on computer models as to how the spread and impact of alien species will change in the future. Therefore, expert assessments via standardised surveys are an important tool to obtain a better understanding of the causes and consequences of the spread and impact of alien species for the coming decades," says Franz Essl.
The study shows that an increase of 20 to 30 per cent in the number of newly introduced alien species is considered sufficient to cause massive global biodiversity loss - a value that is likely to be reached soon, as the number of introduced species is constantly increasing.
Climate change and trade drive increase
Furthermore, humans are the main driver of the future spread of alien species. The experts identify three main reasons, primarily the increasing global transport of goods, followed by climate change and then the impacts of economic development such as energy consumption and land use. The study also shows that the spread of alien species can be greatly slowed down by ambitious countermeasures.
The researchers additionally investigated the influence of the increase of alien species on different regions of the world: For example, tourism is a major driver of biological invasions in tropical and subtropical regions, while climate change favours the survival and establishment of alien species in the future, especially in polar and temperate regions.
"Our study illustrates the option space we currently have to reduce the future impacts of alien species," says Bernd Lenzner.
"The results form an important scientific basis for the further development of international agreements such as the Sustainable Development Goals or the Convention on Biological Diversity. This way we will be able to reduce the negative impacts of alien species on global biodiversity and our society."
The study involved 38 researchers from across Europe, North and South America, New Zealand and South Africa.
Helen Roy of the UK Centre for Ecology & Hydrology, one of the co-authors, says: "There has been a rapid escalation in the number of non-native species being transported and introduced by humans around the world; the adverse effects of some of these so called invasive non-native species on biodiversity and ecosystems has been extensively documented.
"It is now critical that we work collaboratively to predict future patterns so that we can inform appropriate action going forward - such as improved biosecurity to prevent further introductions of the most damaging invasive non-native species."
###
Notes to editors
Essl, F et al. 2020. Drivers of future alien species impacts: An expert-based assessment. Global Change Biology. DOI: 10.1111/gcb.15199
Lead authors: Ass.-Prof Mag Dr Franz Essl Department of Botany and Biodiversity Research, University of Vienna, 1030 Wien, Rennweg 14/1 franz.essl@univie.ac.at
Dr Bernd Lenzner Department of Botany and Biodiversity Research, University of Vienna, 1030 Wien, Rennweg 14/1 bernd.lenzner@univie.ac.at
