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, June 16, 2021
Small streams in agricultural ecosystems are heavily polluted with pesticides
The environmental risks of pesticides need to be revised
IMAGE: FOR TWO YEARS, RESEARCHERS STUDIED PESTICIDE CONTAMINATION
IN SMALL STREAMS IN AGRICULTURAL LANDSCAPES. view more
CREDIT: ANDRÉ KUENZELMANN / UFZ
Pesticides safeguard agricultural yields by controlling harmful insects, fungi, and weeds. However, they also enter neighbouring streams and damage the aquatic communities, which are crucial for maintaining biodiversity, are part of the food web and support the self-purification of water. In a nationwide monitoring programme, a consortium of scientists led by the Helmholtz Centre for Environmental Research (UFZ) has shown that the governmental thresholds for pesticides are generally too high and that even these excessively high levels are still exceeded in over 80% of water bodies. As they published in the scientific journal Water Research the loss of biodiversity can only be halted if the environmental risk assessment of pesticides is radically revised.
For two years, the researchers studied pesticide contamination at more than 100 monitoring sites on streams flowing through predominantly agricultural lowland regions in 12 federal states in Germany. They found significant exceedances of the RAC value - the concentration of an active ingredient specified in the official approval procedure for a pesticide, which should not be exceeded in the water body in order to prevent negative effects on aquatic organisms. In most of the small streams investigated, the RAC values were exceeded (81%). In 18% of the streams, such exceedances were detected for more than 10 pesticides. "We have detected a significantly higher pesticide load in small water bodies than we originally expected", says Prof. Matthias Liess, ecotoxicologist at the UFZ and coordinator of the small water monitoring project. For example, in three water bodies, the insecticide thiacloprid exceeded the RAC value by more than 100-fold. In 27 streams the insecticides clothianidin, methiocarb, and fipronil as well as herbicides such as terbuthylazine, nicosulfuron, and lenacil exceeded the RAC value 10- to 100-fold.
Because of the extensive data set, the researchers were able to reveal that pesticides affect aquatic invertebrate communities at much lower concentrations than previously assumed by the pesticide risk assessment. The concentrations depend on which species are to be conserved. For example, sensitive insect species such as caddisflies and dragonflies require much lower (1.000-fold) threshold values than snails and worms. "For sensitive insect species, the pesticide concentration in the small lowland streams is the most relevant factor that determines their survival. In contrast, other environmental problems such as watercourse expansion, oxygen deficiency, and excessive nutrient content are less important. For the first time this study allows a ranking of environmental problems", says Liess.
For the current approval of pesticides, the high sensitivity of species in the ecosystem context is grossly underestimated. Until now, the ecological risk of pesticides in the field has been predicted based on laboratory studies, artificial ecosystems, and simulation models. However, according to Liess, the results from the laboratory do not reflect reality. "In addition to pesticides, many other stressors act on organisms in the ecosystem. These make them much more sensitive to pesticides. Natural stressors such as predation pressure or competition between species are not sufficiently taken into account in the risk assessment. But these obvious problems often go unnoticed because the degree of pesticide contamination and the effect of this have not been validated in the field - neither in Germany nor in other countries", he says.
In the course of the project, the scientists also found that the type of sampling has a drastic influence on the concentrations of pesticides measured. In addition to the scoop sample specified as standard by the EU Water Framework Directive, they also took an "event sample". Here, an automatically controlled sampler takes water samples from the water body after a rain event. "The event sample provides much more realistic results because the pesticides enter the water bodies as a result of the increased surface run-off from the field, especially during rain", says Liess. Compared to the scoop samples, the event-related samples show a 10-fold higher pesticide load. "In order to realistically depict the water pollution, samples must therefore be taken after rainfall events. That's why we need an official regular environmental monitoring to be able to assess the amount and the effects of pesticides," says Matthias Liess. He and his colleagues also demand that new scientific findings be incorporated into the approval process for new pesticides more quickly. "We are still using pesticides that were approved many years ago based on an outdated risk assessment. This must therefore change as soon as possible. Only in this way can we preserve the biodiversity in our waters and with it the services that these biotic communities provide for our ecosystems."
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The pilot study "Small Water Body Monitoring" (KgM) commissioned by the Federal Environment Agency was carried out under the leadership of the UFZ Department of System-Ecotoxicology and financed by the UFZ and the Federal Environment Agency. Eleven UFZ departments, the University of Koblenz-Landau, the University of Duisburg-Essen, the University of Kiel, the Federal Environment Agency, and the environmental authorities of the 12 participating federal states participated.
IMAGE: JUST TWO WEEKS OF CITALOPRAM EXPOSURE CAUSED CHANGES IN CRAYFISH BEHAVIOR. view more
CREDIT: STEFAN, INATURALIST
Pharmaceutical pollution is found in streams and rivers globally, but little is known about its effects on animals and ecosystems. A new study, published in the journal Ecosphere, investigated the effects of antidepressant pollution on crayfish. Just two weeks of citalopram exposure caused changes in crayfish behavior, with the potential to disrupt stream ecosystem processes like nutrient cycling, oxygen levels, and algal growth.
Coauthor Emma Rosi, a freshwater ecologist at Cary Institute of Ecosystem Studies, says, "Animals living in streams and rivers are exposed to a chronic mix of pharmaceutical pollution as a result of wastewater contamination. Our study explored how antidepressant levels commonly found in streams impact crayfish, and how these changes reverberate through stream ecosystems."
Crayfish are a keystone species in streams, where they eat invertebrates, break down leaf litter, and cycle nutrients. They are stress-tolerant and can become abundant in urban waterways. These freshwaters are prone to receiving pharmaceutical pollution from sewer overflows, leaky septic tanks, and treated wastewater effluent that contains pharmaceuticals.
Lead author Alexander Reisinger, an Assistant Professor at University of Florida, Gainesville, says, "Previous research via direct injection found that antidepressants alter serotonin and aggression in crustaceans. Our study found that exposure to low doses of citalopram - at levels currently found in urban streams as a result of pollution - is enough to alter crayfish behaviors like foraging, aggression, and shelter use."
Cary Institute's artificial stream facility was used to test effects of citalopram on crayfish and stream ecosystems. Twenty stream habitats were created with low-nutrient groundwater and quartz rocks and red maple leaf packs that had been colonized with microbes, invertebrates, and algae. Streams were randomly selected to receive one of four treatments: no citalopram + no crayfish, citalopram + no crayfish, crayfish + no citalopram, and citalopram + crayfish. Each treatment was applied to five streams. Three male crayfish were added to each of the 'crayfish' streams.
For two weeks, the team dosed the 10 streams receiving citalopram every other day to mimic low, persistent pharmaceutical pollution found in urban streams. Over the course of the experiment, they monitored indicators that would reveal changes in stream ecosystem functioning, such as dissolved oxygen, temperature, light penetration, and algae. At the end of the two weeks, the behavior of exposed and non-exposed crayfish was tested.
To do this, the team tapped into crayfish's keen sense of smell. They used a tank containing a shelter at one end and a divider down the middle. One side of the tank contained water that had passed by sardine gelatin; the other contained water that had passed by another male crayfish. One at a time, they placed the crayfish in the shelter, then recorded the amount of time it took for each to peek out of the shelter and emerge completely. They also recorded the amount of time spent in the sardine and crayfish signal sides of the tank.
Crayfish exposed to citalopram emerged from the shelter sooner, indicating increased 'boldness'. Exposed crayfish were also more interested in food, lingering in the food-scented area over 3x longer than the crayfish-scented area. Crayfish that were not exposed to citalopram took longer to emerge and divided their time equally between the food and crayfish areas, showing no preference.
Reisinger explains, "Citalopram-exposed crayfish are more attracted to food, and less interested in other crayfish. Less time spent hiding and more time foraging could make crayfish more vulnerable to predators, meaning more get eaten. We would expect increased crayfish foraging to lead to higher rates of leaf litter decomposition and biofilm turnover, altering in-steam nutrient flows. Either of these changes could have cascading effects."
In people, 'metabolism' refers to a collection of chemical processes that regulate bodily functions essential to health like breathing, digestion, and temperature regulation. Stream 'metabolism' includes a variety of indicators like oxygen levels, light penetration, and nutrient cycling, which together shape stream health.
The team used their two-week record of stream indicators to assess changes in the metabolism of each stream. They found that crayfish presence versus absence significantly affects stream metabolism. Effects of citalopram alone were not significant, but results suggest that changes in stream functioning would likely occur over time due to citalopram's effects on crayfish behavior.
Reisinger explains, "With just two weeks of citalopram exposure, we saw marked changes in crayfish behavior. Over months to years, we would expect these changes to magnify. Fewer crayfish could reduce populations of the fish that eat them like trout, bass, and catfish. Changes in algal growth or turnover would alter oxygen levels and nutrient dynamics - key aspects of stream functioning that could cause harmful imbalances in the system."
Rosi concludes, "Toxicity assessments of pharmaceuticals often focus on lethal effects, but it is clear that these drugs can affect non-target organisms without killing them and behavioral changes can have ecological consequences. More work is needed to understand how pharmaceutical pollution impacts stream life at chronic, sublethal levels, and what these changes mean for freshwater quality, ecosystem health, and foodwebs - in streams and beyond."
CAPTION
Three months before the experiment, the team placed packets of dried maple leaves and quartz rocks in a local creek and left them to gather communities of algae, bacteria, fungi, and invertebrates. The colonized leaf packs and rocks were then placed in Cary Institute's artificial streams to mimic a natural stream ecosystem.
CREDIT
AJ Reisinger
Investigators
Alexander Reisinger - University of Florida, Soil and Water Sciences Department Lindsey Reisinger - University of Florida, Fisheries and Aquatic Sciences Program Erinn Richmond - Monash University, Water Studies Center, School of Chemistry Emma Rosi - Cary Institute of Ecosystem Studies
Cary Institute of Ecosystem Studies is an independent nonprofit center for environmental research. Since 1983, our scientists have been investigating the complex interactions that govern the natural world and the impacts of climate change on these systems. Our findings lead to more effective management and policy actions and increased environmental literacy. Staff are global experts in the ecology of: cities, disease, forests, and freshwater.
CAPTION
The spinycheek crayfish used in the study were collected from a local stream.
CREDIT
AJ Reisinger
Not acting like themselves: Antidepressants in environment alter crayfish behavior
Crayfish exposed to low levels of antidepressant medication behaved in ways that could make them more vulnerable to predators
UNIVERSITY OF FLORIDA
WITH MUSIC
VIDEO: CRAYFISH IN LINDSEY REISINGER'S LAB AT THE UNIVERSITY OF FLORIDA.view more
CREDIT: BRIANNE LEHAN/UNIVERSITY OF FLORIDA
Antidepressants can help humans emerge from the darkness of depression. Expose crayfish to antidepressants, and they too become more outgoing -- but that might not be such a positive thing for these freshwater crustaceans, according to a new study led by scientists with the University of Florida.
"Low levels of antidepressants are found in many water bodies," said A.J. Reisinger, lead author of the study and an assistant professor in the UF/IFAS soil and water sciences department. "Because they live in the water, animals like crayfish are regularly exposed to trace amounts of these drugs. We wanted to know how that might be affecting them," he said.
Antidepressants can get into the environment through improper disposal of medications, Reisinger said. In addition, people taking antidepressants excrete trace amounts when they use the bathroom, and those traces can get into the environment through reclaimed water or leaky septic systems.
The researchers found that crayfish exposed to low levels of antidepressant medication behaved more "boldly," emerging from hiding more quickly and spending more time searching for food.
"Crayfish exposed to the antidepressant came out into the open, emerging from their shelter, more quickly than crayfish not exposed to the antidepressant. This change in behavior could put them at greater risk of being eaten by a predator," said Lindsey Reisinger, a co-author of the study and an assistant professor in the UF/IFAS fisheries and aquatic sciences program.
"Crayfish eat algae, dead plants and really anything else at the bottom of streams and ponds. They play an important role in these aquatic environments. If they are getting eaten more often, that can have a ripple effect in those ecosystems," Lindsey Reisinger added.
In their study, conducted while A.J. Reisinger was a postdoctoral researcher at the Cary Institute of Ecosystem Studies, the scientists wanted to understand how crayfish respond to low levels of antidepressants in aquatic environments.
"Our study is the first to look at how crayfish respond when exposed to antidepressants at levels typically found in the streams and ponds where they live," A.J. Reisinger said.
The researchers achieved this by recreating crayfish's natural environment in the lab, where they could control the amount of antidepressant in the water and easily observe crayfish behavior.
Crayfish were placed in artificial streams that simulated their natural environment. Some crayfish were exposed to environmentally realistic levels of antidepressant in the water for a few weeks, while a control group was not exposed. The researchers used a common type of antidepressant called a selective serotonin reuptake inhibitor, or SSRI.
To test how antidepressant exposure changed crayfish behavior, researchers used something called a Y-maze. This maze has a short entrance that branches into two lanes, like the letter Y.
At the start of the experiment, the researchers placed each crayfish in a container that acted as a shelter, and that shelter was placed at the entrance to the maze.
When researchers opened the shelter, they timed how long it took for the crayfish to emerge. If the crayfish emerged, they had the choice of the two lanes in the Y-maze. One lane emitted chemical cues for food, while the other emitted cues that signaled the presence of another crayfish. The researchers recorded which direction the crayfish chose and how long they spent out of the shelter.
Compared to the control group, crayfish exposed to antidepressants emerged from their shelters earlier and spent more time in pursuit of food. They tended to avoid the crayfish side of the maze, a sign that the levels of antidepressants used in study didn't increase their aggression.
"The study also found that crayfish altered levels of algae and organic matter within the artificial streams, with potential effects on energy and nutrient cycling in those ecosystems," A.J. Reisinger said. "It is likely that the altered crayfish behavior would lead to further impacts on stream ecosystem functions over a longer time period as crayfish continue to behave differently due to the SSRIs. This is something we'd like to explore in future studies."
The study, co-authored with Erinn Richmond of Monash University and Emma Rosi of the Cary Institute of Ecosystem Studies, is published in the journal Ecosphere.
Wondering how you can reduce the levels of antidepressants and other pharmaceuticals in water bodies? There are steps people can take, A.J. Reisinger said.
"The answer is not for people to stop using medications prescribed by their doctor. One big way consumers can prevent pharmaceuticals from entering our water bodies is to dispose of medications properly," he said.
WITHOUT MUSIC
A.J. Reisinger has authored an Extension publication and infographic on how to dispose of unwanted medications properly and keep them out of water bodies.
Baltic herring larvae appear earlier and grow faster due to climate change
Data collected for over two decades shows that rising Baltic Sea water temperature is one of the main factors in the increasingly earlier appearance and faster growth of Baltic herring larvae.
Baltic herring (Clupea harengus membras) is commercially the most important fish species in Finland, and an important part of the Baltic marine ecosystem. Conditions during herring spawning may have cascading effects on the whole Baltic ecosystem.
According to a recent research, both developmental stages in Baltic herring larvae, small and large, have shifted their timing to earlier dates.
"This suggests that herring spawn earlier and larvae grow faster, by about 7.7 days per decade. Water temperature and the amount of chlorophyll a in the water, the latter serving as an estimate for the larval food resources, were strong drivers of this change," says postdoctoral researcher Benjamin Weigel from the University of Helsinki.
"The results of the study describe the effects of climate change on the Baltic Sea ecosystem and one of its key species," says research programme leader Meri Kallasvuo from Natural Resources Institute Finland.
Temporal changes in the biological life cycle of Baltic herring can become critical for the survival of species when there is a mismatch in timing between prey and consumer, especially during early life stages.
Researchers from the University of Helsinki and Natural Resources Institute Luke used data collected over 22 years from a herring larvae survey that was conducted in several areas along the whole Baltic coast of Finland.
"Usually there are no exact dates of first larvae hatching available, so we modelled changes in the Baltic herring larvae based on occurrence probabilities and relative abundances of different size classes of fish larvae. We predicted the day of the year when the smallest larvae had a high probability of occurrence, and when largest larvae made up a significant percentage of all larvae. Earlier dates in high occurrence probabilities of the smallest larvae indicate relatively earlier spawning, and earlier dates in proportions of the largest larvae would indicate faster larvae growth," Benjamin Weigel points out.
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Cosmic rays: Coronal mass ejections and cosmic ray observations at Syowa Station in the Antarctic
Solar activities, such as CME(Coronal Mass Ejection), cause geomagnetic storm that is a temporary disturbance of the Earth's magnetosphere. Geomagnetic storms can affect GPS positioning, radio communication, and power transmission system. Solar explosions also emit radiation, which can affect satellite failures, radiation exposure to aircraft crew, and space activity. Therefore, it is important to understand space weather phenomena and their impact on the Earth.
Space weather research by continuous observation of cosmic rays on the ground is mainly conducted using observation data from neutron monitors and multi-directional muon detectors. Since the phenomenon of space weather is on a short-term, days-long scale, it is effective to investigate changes in the flow of cosmic rays for several hours, which requires a total sky monitor of cosmic rays. In the muon detector, the global muon detector network (GMDN) has been observing space weather phenomena since 2006, and in the neutron monitor, the Spaceship Earth project constitutes a similar observation network and the role of the all-sky monitor. Until now, observations by neutron monitors and muon detectors have been performed independently, and progress has been made in space weather research.
In February 2018, Professor Chihiro Kato of Shinshu University took the lead in acquiring simultaneous observations of the neutron monitor and muon detector at Syowa Station in the Antarctic in order to acquire bridging data of observations by the neutron monitor and muon detector. In the polar regions, unlike low latitude regions on the earth, it is possible to observe cosmic rays coming from the same direction with a neutron monitor and a muon detector due to the weaker deflection by the geomagnetism. This is the reason why Syowa Station was selected as the observation point.
Syowa muon detector and neutron monitor observed small fluctuation in CR count like a Forbush decrease on 2018.8. The research group including researchers from Shinshu University and the National Polar Research Institute found curious cosmic-ray density variation on this event by analyzing GMDN data.
On the CME event, a huge amount of coronal material released with a bundle of the solar magnetic field, called Magnetic Flux Rope (MFR), into the interplanetary space. MFR moves through interplanetary space as expanding. CR density is low inside of it because it is originally coronal material. When the Earth enters the MFR, CR counts on the ground decreases. This is called Forbush Decrease.
Normally, when MFR arrives on Earth, CR density observed at the ground level decreases rapidly, and then turns to increase recovering to the original level while the Earth is in the MFR. On this event, however, the CR exceeds the original level before the Earth exits the MFR.
This event attracts interest from researchers because 1) The solar activity is currently near the minimum and the scale of the event itself is small, 2) It causes a disproportionately large geomagnetic storm, and 3) There is high-speed solar wind catching up the MFR expected to interact with it.
By analysis of the GMDN and solar plasma data, it is concluded that the high-speed solar wind causes the unusual enhancement of the CR density by compressing the rear part of the MFR locally.
Cosmic ray observation data is closely related not only to space weather research but also to atmospheric phenomena such as sudden stratospheric temperature rise and is expected to be used in a wide range of fields in the future. The cosmic ray observation data at Syowa Station, including the phenomenon in August 2018, which was the subject of this research, is published on the website and updated daily: http://polaris.nipr.ac.jp/~cosmicrays/
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Acknowledgments
The authors are grateful to Center for Antarctic Programs at NIPR (National Institute of Polar Research), JARE59 team, and Shirase crew for installing the system to Syowa Station. This research project is supported by NIPR, ICRR (Institute of Cosmic Ray Research, Tokyo University), ISEE (Institute for Space-Earth Environmental Research, Nagoya University), University of Delaware, and Shinshu University. Some of the scientific data of this research project has begun to be published at http://polaris.nipr.ac.jp/~cosmicrays/ supported by ROIS-DS-JOINT2018. The Bartol Research Institute neutron monitor program is supported by the United States National Science Foundation under grants PLR-1245939 and PLR-1341562, and by Department of Physics and Astronomy and the Bartol Research Institute, the University of Delaware. The neutron monitor data from Thule are provided by the University of Delaware Department of Physics and Astronomy and the Bartol Research Institute. The neutron monitor data from South Pole and the South Pole Bares are provided by the University of Wisconsin, River Falls. We acknowledge the NMDB database (http://www.nmdb.eu), founded under the European Union's FP7 program (contract no. 213007) for providing data. The editor thanks two anonymous reviewers for their assistance in evaluating this paper.
Those breakfast foods are fortified for a reason
Adults who skip morning meal miss out on nutrients, study finds
COLUMBUS, Ohio - Adults who skip breakfast are likely to miss out on key nutrients that are most abundant in the foods that make up morning meals, a new study suggests.
An analysis of data on more than 30,000 American adults showed that skipping breakfast - and missing out on the calcium in milk, vitamin C in fruit, and the fiber, vitamins and minerals found in fortified cereals - likely left adults low on those nutrients for the entire day.
"What we're seeing is that if you don't eat the foods that are commonly consumed at breakfast, you have a tendency not to eat them the rest of the day. So those common breakfast nutrients become a nutritional gap," said Christopher Taylor, professor of medical dietetics in the College of Medicine at The Ohio State University and senior author of the study.
According to the U.S. Department of Agriculture's latest dietary guidelines, calcium, potassium, fiber and vitamin D are considered "dietary components of public health concern" for the general U.S. population - with iron added for pregnant women - because shortages of those nutrients are associated with health problems.
Most research related to breakfast has focused on the effects of the missed morning meal on children in school, which includes difficulty focusing and behavioral problems.
"With adults, it's more like, 'You know how important breakfast is.' But now we see what the implications really are if they miss breakfast," Taylor said.
He completed the study with Ohio State School of Health and Rehabilitation Sciences graduate students Stephanie Fanelli and Christopher Walls. The research, which was supported by a regional dairy association, is published online in Proceedings of the Nutrition Society.
The team used data from the National Health and Nutrition Examination Survey (NHANES), which collects health information on a nationally representative sample of about 5,000 people every year through interviews, laboratory tests and physical exams.
The sample for this study included 30,889 adults age 19 and older who had participated in the survey between 2005 and 2016. The Ohio State researchers analyzed data from 24-hour dietary recalls participants completed as part of the NHANES survey.
"During the recall, participants self-designate their eating occasions as a meal or a snack, and they tell you at what point in time they ate whatever food they report," said Fanelli, first author of the study. "That's how we determined whether someone was a breakfast eater or a breakfast skipper."
In this sample, 15.2% of participants, or 4,924 adults, had reported skipping breakfast.
The researchers translated the food data into nutrient estimates and MyPlate equivalents using the federal Food and Nutrient Database for Dietary Studies and daily dietary guidelines, and then compared those estimates to recommended nutrient intakes established by the Food and Nutrition Board of the National Academies.
On several key recommendations measured, from fiber and magnesium to copper and zinc, breakfast skippers had taken in fewer vitamins and minerals than people who had eaten breakfast. The differences were most pronounced for folate, calcium, iron, and vitamins A, B1, B2, B3, C and D.
"We found those who skipped breakfast were significantly more likely not to meet the bottom threshold of what we hope to see people eat," Fanelli said.
Compared to the Healthy Eating Index-2015, which assesses how well a set of foods aligns with federal recommendations, breakfast skippers also had an overall lower-quality diet than those who ate breakfast.
For example, breakfast skippers were more likely than those who noshed in the morning to eat more added sugars, carbohydrates and total fat over the course of the day - in part because of higher levels of snacking.
"Snacking is basically contributing a meal's worth of calorie intakes for people who skipped breakfast," Taylor said. "People who ate breakfast ate more total calories than people who didn't eat breakfast, but the lunch, dinner and snacks were much larger for people who skipped breakfast, and tended to be of a lower diet quality."
While the data represent a single day in each participant's life, the huge sample provides a "nationally representative snapshot for the day," Taylor said.
"It shows that those who skipped breakfast had one nutrient profile and those who ate breakfast had a different nutrient profile," he said. "It helps us identify on any given day that this percentage of people are more likely to be skipping breakfast. And on that day, their dietary intake pattern showed that their consumption didn't capture those extra nutrients that they have basically missed at breakfast."
This work was supported by the National Dairy Association Mideast.
Accomplished University of Ottawa professors earn Canada Research Chairs
The University of Ottawa has been awarded four new Canada Research Chairs
IMAGE: FIRST ROW, FROM LEFT TO RIGHT: PROFESSORS KHALED EL EMAM, RITA HORVATH AND CAROLE YAUK. SECOND ROW, FROM LEFT TO RIGHT: PROFESSORS EMMANUELLE BERNHEIM, EBRAHIM KARIMI AND KSENIA DOLGALEVA. view more
CREDIT: THE UNIVERSITY OF OTTAWA
The University of Ottawa has been awarded four new Canada Research Chairs (CRC) that will strengthen its expertise in artificial intelligence, health and law. The University is also proud to announce the renewal of two CRCs that will conduct leading-edge research in quantum communications and photonics.
"The Canada Research Chairs Program provides invaluable support to our researchers as they forge their paths of discovery at a world-class level," said Sylvain Charbonneau, vice-president, research. "The results of this most recent competition will undeniably help the University succeed in pursuing our goals of excellence, relevance and research impact."
The three new Tier 1 Canada Research Chairs are:
Khaled El Emam (Faculty of Medicine and CHEO Research Institute) -- Canada Research Chair in Medical Artificial Intelligence
Khaled El Emam's research will focus on developing a methodology for the synthesis of complex health data. This means applying artificial intelligence techniques to model personal clinical and biological information stored in databases. These models can be used to generate virtual patients that mimic the characteristics of real patients. This solves data-sharing problems and enables adding simulated patients to accelerate clinical studies.
Rita Horvath (Faculty of Medicine and CHEO Research Institute) -- Canada Research Chair in Mitochondrial Disease Pathogenesis to Therapy
Mitochondrial diseases are genetic disorders that are difficult to diagnose and cause a range of devastating physical, developmental and intellectual disabilities. Rita Horvath's research aims to understand the molecular mechanisms of mitochondrial disease, to provide accurate diagnosis and develop targeted therapies.
Carole Yauk (Faculty of Science) -- Canada Research Chair in Genomics and the Environment
Carole Yauk's research addresses an urgent need to modernize the toxicological risk assessment of environmental chemicals. She will develop and deploy genomics approaches that measure how toxic chemicals can alter the function of genes or damage genetic material. Her laboratory will work with regulatory and industry partners to determine the best use of this information, to predict toxicological risks to humans and wildlife.
The new Tier 2 Canada Research Chair is:
Emmanuelle Bernheim (Faculty of Law, Common Law Section) -- Canada Research Chair in Mental Health and Access to Justice
Emmanuelle Bernheim's research looks at improving access to the justice system for diverse groups, particularly those living with mental health issues, while focussing on community, political and research circles.
The two renewed Tier 2 Canada Research Chairs are:
Ksenia Dolgaleva (Faculty of Engineering) -- Canada Research Chair in Integrated Photonics
Photonic integration uses light for applications traditionally performed by electronics. Combining a laser source, waveguides that direct light and other optical components on a small semiconductor chip, photonics has a number of uses in areas such as medicine, information and communication technologies, and sensing. Ksenia Dolgaleva's research aims to increase the functionality of existing optical chips by developing integrated optical devices that can manipulate light in new ways. These devices will be able to change the colour of incident light and manipulate light with light. This is essential to all-optical processing of information channels without needing to convert them to an electrical current.
Ebrahim Karimi (Faculty of Science) -- Canada Research Chair in Structured Quantum Waves
Ebrahim Karimi's research program uses structured quantum waves to enhance capabilities and open new horizons in quantum communication protocols, simulators and sensing. Robust yet compact devices will be designed to efficiently structure electron and optical beams, increasing the security and capacity of information transmission -- the key to establishing the first quantum network across Ottawa -- as well as measuring and analyzing materials properties quickly on a small scale.
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Investigating carbonate mineral chemical variations to improve oil recovery
One-size-fits-all approach to well stimulation doesn't always work
Dr. Igor Ivanishin, a postdoctoral researcher in the Harold Vance Department of Petroleum Engineering at Texas A&M University, has firsthand experience with the frustrations of oil production. He spent nine years as a hydraulic fracturing engineer with operating and service companies in Russia. A few years ago, he came to Texas A&M to get his doctoral degree while delving into a reoccurring recovery problem in carbonate reservoirs: why don't they produce oil as predicted?
Ivanishin is investigating variations in the chemical composition of dolomite and calcite minerals to prove why a one-size-fits-all approach to well stimulation in carbonate reservoirs doesn't always work. Because these formations occur worldwide, his research has attracted the attention of several major oil and gas companies that want to collaborate with him and improve well stimulation operations.
The chemical crystalline lattice of ideal dolomite has regularly alternating layers of calcium and magnesium. When dolomites naturally form in sedimentary rock, extra calcium ions can substitute for magnesium ions. This modification expands the crystal lattice and makes it less stable. A similar situation happens in calcite, a mineral that doesn't contain magnesium or other ions in pure form but can in reservoirs.
Such variations are typical in sedimentary rocks but are not yet considered in well stimulation software models. Current modeling methods assume both dolomite and calcite have an ideal chemical composition that does not vary spatially within the carbonate reservoir. Thus, reservoir rock is thought to react at the same rate everywhere when acids are injected to dissolve the rock and form the channels or wormholes for oil and other hydrocarbons to travel through.
"I found publications that reported the presence of impurities in carbonates, but the authors did not think about variation in the chemical structure of these minerals," said Ivanishin. "These are angstrom-level tiny things, so it's difficult to imagine that such a small-size variation in chemical composition may affect the stability of the mineral, but it does."
As a doctoral student, Ivanishin consulted with geologists, mineralogists and chemical geologists on the subject. He received and personally collected dolomite samples from around the world. Initial chemical composition analysis of the different samples helped him to select dolomites with varying excess calcium contents. The reaction of these samples with hydrochloric acid revealed that having extra calcium, a calcium uptake, increased the rate dolomite dissolved up to five times greater than usual. He concluded that because the chemical composition of dolomite does vary spatially, injected acids would unevenly dissolve the rock in the target zone and not travel further into the reservoir, leaving some areas untouched.
For his postdoctoral research, Ivanishin is working with a large collection of calcites from Japan. He wants to determine if magnesium ions in calcite also change the dissolution rate of this mineral in acids. If calcite behaves the same way as dolomite, this should affect the design of stimulation treatments and other operations in carbonate formations, such as CO2 injection.
Ivanishin is currently working on creating computer simulations of these molecular variances and associated dissolution reactions so they can be easily shared and studied. His goal is to provide information to companies and consult with them on applications of this discovery in the field.
Though the investigation requires hard work and long hours, Ivanishin is glad the problem led him to College Station, Texas. Years ago, he talked with visiting international speakers at his former job about the carbonate recovery issue, including professors from Texas A&M. He decided to explore the university in person as a visiting student, then came back when he discovered it was the right place to be.
"I decided the next step in my career should be a Ph.D. from one of the best universities in the world," said Ivanishin. "The experience obtained here, talking with people from different companies, working with other engineers, exchanging ideas with experts from different fields and gathering information, is like a point of contact with the whole petroleum engineering world."
In 1943, two scientists named Max Delbrück and Salvador Luria conducted an experiment to show that bacteria can mutate randomly, independent of external stimulus, such as an antibiotic that threatens a bacterial cells' survival. Today the Luria-Delbrück experiment is widely used in laboratories for a different purpose--scientists use this classic experiment to determine microbial mutation rates. When performing the Luria-Delbrück experiment, scientists need efficient computer algorithms to extract reliable estimates of mutation rates from data, and they also need well-designed software tools to access these sophisticated algorithms.
Through the years, several web tools that allow researchers to more easily input and analyze data on a computer were developed to increase efficiency and efficacy of the Luria-Delbrück experiment. However, no existing web tool allows scientists to access many recently developed algorithms that can extract even more accurate estimates of microbial mutation rates from data.
Qi Zheng, PhD, professor at the Texas A&M University School of Public Health, recently developed a new web tool called webSalvador to fill several gaps left by existing web tools. In the Microbiology Resource Announcements (MRA)Journal, Zheng explains how WebSalvador offers many desirable capabilities that are vital to bacteria mutation research, including more accurate methods for constructing confidence intervals and new methods for comparing mutation rates.
The web tool also eliminates the need for scientists to learn programming and software language, which Zheng described as an "important barrier" to using the Luria-Delbrück experiment to tackle important problems in mutation research, such as the global public health headache of bacterial drug resistance.
"Learning software languages can be challenging and time consuming for most biologists," Zheng said. "With webSalvador, biologists can input data and see results easily."
Increasing the efficiency and efficacy of the Luria-Delbrück experiment is important because it can ultimately help advance mutation research, which is vital to many branches of life sciences. Zheng cites bacterial drug resistance as one of the most important applications of the Luria-Delbrück experiment, and refers to multi-drug resistant tuberculosis as an example in which advanced mutation research is vital. He calls microbial drug resistance a "wide-spread, global health problem."
