U of S Researchers Discover Vampire Bugs’ Fatal Flaw

“These insects are developing resistance to insecticides, so we need to better understand their biology to find new ways for killing them and limit the spread of Chagas disease,” said U of S physiology professor Juan Ianowski.

Untreatable and often undetected, Chagas disease affects six to seven million people, mostly in Latin America where it spreads mainly through Rhodnius prolixus, known as the “kissing bug” for its habit of biting around its victim’s mouth.

Infected bugs deposit the Chagas disease parasites into a victim’s blood system when feeding. The human immune system cannot kill the parasites which keep mutating and cause severe heart problems that lead to death within 10 to 30 years.

Ianowski and his PhD student Xiaojie Luan have been the first to provide evidence that the special circulation system in the vampire bug’s head prevents the heat of the incoming blood meal from harming the bug. Their findings, published last week in the journal eLife, may be used to develop chemicals that could disrupt the insects’ heat exchange system to kill the critters.

The research was done at the U of S Canadian Light Source (CLS) synchrotron in collaboration with researchers from France and Brazil.

“We needed very high imaging resolution and the CLS was the only place that had X-rays powerful enough to visualize how the blood moves from the insects’ mouths to their bodies,” said Luan, who developed a new imaging technique at the synchrotron to scan the live insects.

The researchers showed that meal blood and the insect’s blood, which are at different temperatures, flow in opposite directions and slowly exchange heat—the secret of the insect’s survival.

“We’ve seen similar mechanisms in the body of other insects, but this is the first time we found it in the head of an insect,” said Ianowski.

Luan, who moved from China to pursue his post-secondary education at the U of S, took images and shot videos of more than 50 insects feeding. He used insects that Ianowski grew in the lab, where thousands of them are kept in jars.

“My insects, of course, don’t have the Chagas disease parasites and are completely harmless,” said Ianowski.

“Some Latin American species can survive cold to an extent, so one day we may have them close to here,” said Ianowski. “That’s why it is crucial that we keep researching.”

With climate change, he said the Latin American insects are moving North, and some people in the U.S. who never went abroad have been infected. Immigration of infected people could also be a factor.

The U of S team was funded by the Canadian Institutes of Health Research (CIHR) and the Natural Sciences and Engineering Research Council (NSERC), and were led by Claudio Lazzari, a researcher at the University of Tours in France.

Source : University of Saskatchewan

Appetizing Imagery Puts Visual Perception on Fast Forward

People rated images containing positive content as fading more smoothly compared with neutral and negative images, even when they faded at the same rate, according tofindings published in Psychological Science, a journal of the Association for Psychological Science.

“Our research shows that emotionally-charged stimuli, specifically positive and negative images, may influence the speed, or the temporal resolution, of visual perception,” says psychological scientist Kevin H. Roberts of the University of British Columbia.

The idea that things in our environment, or even our own emotional states, can affect how we experience time is a common one. We say that time “drags” when we’re bored and it “flies” when we’re having fun. But how might this happen? Roberts and colleagues hypothesized that the emotional content of stimuli or experiences could impact the speed of our internal pacemaker.

Specifically, they hypothesized that our motivation to approach positive stimuli or experiences would make us less sensitive to temporal details. Change in these stimuli or experiences would, therefore, seem relatively smooth, similar to what happens when you press ‘fast forward’ on a video. Our desire to avoid negative stimuli or experiences, on the other hand, would enhance our sensitivity to temporal details and would make changes seem more discrete and choppy, similar to a slow-motion video.

To test this hypothesis, Roberts and colleagues used an approach common in psychophysics experiments – estimating relative magnitudes – to gauge how people’s moment-to-moment experiences vary when they view different types of stimuli.

In one experiment, 23 participants looked at a total of 225 image pairs. In each pair, they first saw a standard stimulus that faded to black over 2 seconds and then saw a target stimulus that also faded to black over 2 seconds. The frame rate of the target stimulus varied, displaying at 16, 24, or 48 frames per second.

Participants were generally sensitive to the differences in frame rate, as the researchers expected. Participants rated the smoothness of the target image relative to the standard image using a 21-point scale: The higher the frame rate of the target image, the smoother they rated it relative to the standard image.

The emotional content of the images also made a difference in perceptions of smoothness. Regardless of the frame rate, participants rated negative images—which depicted things we generally want to avoid, including imagery related to confrontation and death—as the least smooth. They rated positive stimuli—depicting appetizing desserts—as the smoothest, overall.

Most importantly, the researchers found that people perceived images that faded at the same rate differently depending on their content. Positive target images that faded at 16 fps seemed smoother than neutral target images that faded at the same rate. Positive images that faded at 24 fps seemed smoother than both negative and neutral images with the same frame rate. And positive images that faded at 48 fps seemed smoother than negative images at the same rate.

Further analyses suggest that this effect occurred primarily because positive images elicited higher approach motivation.

Because the words “smooth” and “choppy” could themselves come with positive or negative connotations, the researchers replaced them with “continuous” and “discrete” in a second experiment. Once again, they found that the emotional content of the images swayed how participants perceived the frame rate of the fade.

Brain-activity data gathered in a third experiment indicated that the blurring of perceptual experience associated with positive images was accompanied by changes in high-level visual processing.

“Even when we made adjustments to the instructions and the task structure, the overall effect remained — people subjectively reported seeing less fine-grained temporal changes in positive images, and they reported seeing more fine-grained temporal changes in negative images,” says Roberts.

Together, these findings suggest that the emotional content of the images affected how participants experienced what they were seeing.

“What remains to be seen is whether emotional stimuli impact objective measures of temporal processing,” says Roberts. “In other words, do individuals actually perceive less temporal information when they view positive images, or do they just believe they perceive less?”

Co-authors on the research include Grace Truong, Alan Kingstone, and Rebecca M. Todd of the University of British Columbia.

This research was supported by a Natural Sciences and Engineering Research Council (NSERC) Discovery grant (RGPIN-2014-04202) to R. M. Todd and by a grant from the Leaders Opportunity Fund of the Canadian Foundation for Innovation (32102) to R. M. Todd.

Source : Association for Psychological Science

Some Marine Species More Vulnerable to Climate Change than Others

Certain marine species will fare much worse than others as they become more vulnerable to the effects of climate change, a new UBC study has found.

After analyzing the biological characteristics of 1,074 marine fish and shellfish, the study identified 294 species that are most at-risk due to climate change by 2050. Species most at-risk include the Eastern Australian salmon, yellowbar angelfish, toli shad, sohal surgeonfish and spotted grouper.

“We hope that this study will highlight the marine species that are most in need of management and conservation actions under climate change,” said William Cheung, associate professor in the Institute for the Oceans and Fisheries and director of science for the Nippon Foundation – UBC Nereus Program.

As part of the study, UBC researchers created a database that examines the long-term vulnerability of marine species that are important to fisheries around the world. The database was developed with an approach that uses “fuzzy logic” to combine information about the biological sensitivity of these species to environmental changes as well as their projected exposure to changes in the ocean including temperature and oxygen and acidity levels.

“How susceptible are Atlantic cod to climate change compared to skipjack tuna? How about smaller fishes such as anchovy and pilchard?” asked Cheung. “We know that some characteristics of the species make them more sensitive and less resilient to climate change.”

The factors that restrict whether fish or shellfish can adapt to climate change include their preferred temperature range, restrictions on their geographic range, how long it takes to reproduce, and specific habitat requirements such as needing kelp or coral reef to survive.

“Eastern Australian salmon is highly vulnerable because their distribution is limited to shallow coastal and estuarine waters in southern Australia and New Zealand,” said Miranda Jones, the study’s lead author, who was a postdoctoral fellow in the Institute for the Oceans and Fisheries when the study was underway. “The species lives in habitats that are exposed to large changes in ocean conditions and have limited scope to avoid these changes.”

In Canada, sockeye salmon, along with the alewife, Pacific bonito, and sharks such as the porbeagle and thresher, are identified as at risk to climate change impacts. In contrast, some species such as the Pacific sanddab, blue crab and Pacific sandlance have less vulnerable biological characteristics and live in areas that are relatively less affected by climate change.

The study “Using fuzzy logic to determine the vulnerability of marine species to climate change” was published today inGlobal Change Biology.

This research was funded by the Nippon Foundation – UBC Nereus Program and the Natural Sciences and Engineering Research Council (NSERC) of Canada.

Background

The researchers used “fuzzy logic” to develop this database. Fuzzy logic allows reasoning and drawing conclusions based on the best available expert and scientific knowledge, even with incomplete or uncertain information. Such fuzzy logic approaches have been applied to study marine biodiversity conservation and fisheries management.

About the Nippon Foundation-UBC Nereus Program

The Nereus Program, a collaboration between the Nippon Foundation and the Institute for the Oceans and Fisheries at the University of British Columbia, has engaged in innovative, interdisciplinary ocean research since its inception in 2011. The program is currently a global partnership of twenty leading marine science institutes with the aim of undertaking research that advances our comprehensive understandings of the global ocean systems across the natural and social sciences, from oceanography and marine ecology to fisheries economics and impacts on coastal communities. Visitnereusprogram.org for more information.

Source : University of British Columbia

New Understanding of How Muscles Work

Muscle malfunctions may be as simple as a slight strain after exercise or as serious as heart failure and muscular dystrophy. A new technique developed at McGill now makes it possible to look much more closely at how sarcomeres, the basic building blocks within all skeletal and cardiac muscles, work together. It’s a discovery that should advance research into a wide range of muscle malfunctions.

Talk about finicky work

Sarcomeres are the smallest unit within a muscle in which all the molecules responsible for making a muscle work can be found intact. These minuscule structures, about one hundred times smaller in diameter than an average human hair, work cooperatively to produce force during muscle contraction. Scientists have known for some time that when muscles are active many million sarcomeres work together, and that muscle malfunctions can be due, at least in part, to miscommunication between sarcomeres. But how exactly this communication takes place has been a mystery until now. Because no one before has been able to isolate a single sarcomere, watch it in action, and measure what’s going on.

“It was very, very tricky and sometimes frustrating for the students working on this project over the last few years,” says Dilson Rassier who teaches in the Department of Kinesiology at McGill and is the lead researcher on the study that was recently published in the prestigious journal Proceedings of the National Academy of Sciences of the United States of America. “We used micro-fabricated needles to measure force and high-tech microscopy to isolate the sarcomeres and then watch them contracting. One of our collaborators had to develop a mathematical model to analyze the data because the numbers involved were so minuscule and so precise.”

Zooming in on microscopic mini-muscles in action

There are between 2,000 and 2,500 sarcomeres found together in linked coils in each 10 millimetres of muscle fibre. To watch the sarcomeres in action, the researchers first had to isolate a single myofibril (the basic rod-like units which make up muscle tissue) and then zoom in on an individual sarcomere. They then experimented with different concentrations of calcium (which is responsible for triggering muscle activation and relaxation) to cause the sarcomeres to contract and measure their force.

What they discovered was that, in a healthy myofibril, all the neighbouring sarcomeres adjust to the activation of one single sarcomere. This finding is new and provocative, showing a cooperative mechanism among sarcomeres in a myofibril that is linked to the specific properties of sarcomeric molecules. This inter-sarcomere dynamic is crucial for the understanding of the molecular mechanism of contraction.

Rassier sounds exultant about the findings: “My group had to work hard to conclude this study, but the results were worth it. The technique opens many possibilities in the muscle field. Since we published our findings a few weeks ago I’ve been hearing from biophysicists and physiologists from around the world who are excited about it. Our next step is to look into what happens in heart failure and other diseases of the muscular system when sarcomeres fail to cooperate.”

Funding was provided by the Canadian Institutes for Health Research (CIHR), the Natural Science and Engineering Research Council of Canada (NSERC), the National Counsel of Technological and Scientific Development (CNPq, Brazil) and the Canada Research Chair Program.

Source : McGill University

UWaterloo and Ciena Research Drives Advancements in Internet Connectivity

Engineering researchers at the University of Waterloo are working with Ciena to find solutions to help network operators and Internet providers respond to the insatiable demand for faster and faster data transmission over the Internet.

A key area of Waterloo’s partnership with Ciena involves squeezing as much capacity as possible out of fibre optic cables that run under the world’s oceans and handle upwards of 95 per cent of all intercontinental communications, including $10 trillion a day in financial transactions.

The reliable, high-speed transmission of vast amounts of information via undersea cables is increasingly important in fields including healthcare and academic research, as well as for consumer demand for quality high-speed Internet service on cell phones.

The research relationship received funding support from the Natural Sciences and Engineering Research Council of Canada (NSERC).

“Waterloo’s strong ties to industry help drive innovation and fuel our economy,” said Feridun Hamdullahpur, president and vice-chancellor of Waterloo. “This partnership with Ciena, possible with support from NSERC, illustrates the tangible, significant results possible when you combine the brilliant minds of Waterloo researchers with the needs and resources of industry.”

Amir Khandani, a professor of electrical and computer engineering at Waterloo, leads a team of post-doctoral fellows and graduate students developing algorithms to efficiently and rapidly correct errors – essentially lost or dropped bits of data — that occur during extremely high-speed, long-distance transmission.

“Professor Khandani and his team, along with their partners at Ciena, have formed an impressive platform for multi-year collaboration that will help tackle the challenges of the next generation of optical telecommunication networks,” said B. Mario Pinto, President, NSERC. “This Industrial Research Chair will also provide the next generation of top research talent with rich training opportunities in highly innovative environments.”

“What matters a great deal to us is knowing that what we do is being used and is benefitting people,” said Khandani, whose team at any given time includes about eight post-doctoral fellows and graduate students. “Seeing our work have a direct and immediate impact is very rewarding.”

Included on electronic chips that are built into equipment for receiving and transmitting data, the algorithms developed by the Waterloo team free up cable capacity while also enabling the correction of errors to keep pace with other technological advances.

“The thirst for additional bandwidth and capacity is unquenchable,” said Rodney Wilson, Senior Director for External Research at Ciena. “It’s a battle of tiny, tiny increments. When you add them all up, it creates market-leading innovations. Working with the University of Waterloo gives us a competitive edge.”

Under the three-year partnership, announced at an event at Waterloo today, Khandani holds the position of Ciena/NSERC Industrial Research Chair on Network Information Theory of Optical Channels. The relationship between Waterloo Engineering and Ciena has already produced seven U.S. patents, with more pending. Many of the student researchers now occupy full-time positions with the company.

Source : University of Waterloo

Fish & Chips: Materials Scientists Help Marine Scientists Track Their Fish

Recently, an innovative materials research group at Dalhousie jumped into the ocean technology game and teamed up with VEMCO, a local company that develops unique tracking solutions for the Ocean Tracking Network and researchers worldwide.

The collaboration will help scientists collect more accurate data on animal behaviour, movement, physiology and the survival of animals in marine and freshwater environments.

Mary Anne White, Harry Shirreff Professor of Chemical Research (Emerita) in the Department of Chemistry, led a small team of researchers on a project unlike any other her group had tackled before.

A new challenge

Dr. White’s Thermal Properties of Materials lab usually focuses on materials that can be used to develop new or improved ways to store energy.

But in a chance conversation with a VEMCO employee at a Halifax Chamber of Commerce dinner, Dr. White learned scientists who study the movement and migratory patterns of fish would benefit from a new kind of acoustic telemetry tag—a tracking device inserted under the skin of a fish. This tag would somehow have to emit a signal when a larger fish ate a tagged fish. That way researchers could better interpret their data knowing the information coming from that tag is associated with a different species.

“He said, ‘we have a problem that materials research might help us solve,’” recalls Dr. White of the conversation over dinner. “So, I wondered, how can my team help develop that signal?”

Dr. White brought the problem to her research group. Kim Miller, a postdoctoral fellow at the time, jumped at the chance to get involved. With a natural “love of fish,” Dr. Miller was a perfect fit, said Dr. White.

“We needed to make a coating for the tag that the stomach acid of another fish would dissolve — it would need to be stable and non-toxic while under the skin of the tagged fish, but unstable and still non-toxic in the stomach acid of the predator,” says Dr. White.

Detailed approach

“It’s a fascinating project, chips in fish. We got to learn a lot about how VEMCO makes these tags. It’s a very intricate procedure,” says Dr. White.

With funding from Natural Sciences and Engineering Research Council of Canada’s (NSERC) Engage program, Dr. White’s team identified that a derivative of a material called chitin provided the right combination of chemical properties for the coating. A product of nature, chitin helps form tough outer skeletons found on lobsters, beetles and spiders.

The placement of the tag was an important factor in the success of this project because tags are inserted under the skin so they can continuously send out information on location, activity and physiology. Dr. White’s modified chitin material would require particular mechanical properties, too. After considerable chemical testing, the team made a coating flexible enough to prevent cracking and swelling while the fish moves about.

marineWhen the coating of the tag encounters the predator’s stomach acid it degrades and triggers the release of a small magnet that emits the signal of predation, changing the output of the tag to indicate that it’s inside of a predator.

Dr. White and Kim Miller, along with former master’s student Ryan Fielden, hold a patent with VEMCO on the successful device now. Called the V5 Predation Tag and available on the company’s website, it reacts to a changing chemical environment on predation and within a matter of hours emits a signal to researchers.

Eddie Halfyard, a former PhD student in the Department of Biology who was supported by the Ocean Tracking Network, is looking forward to what this new tag can do. Currently he’s a marine scientist with the Nova Scotia Salmon Association.

“It allows us to have more confidence in our data, but it also opens up a whole new avenue of research and application for telemetry data,” says Dr. Halfyard.

Flexible solutions

“Materials researchers have a lot of techniques at their fingertips. We look at a lot of materials to find solutions to diverse problems,” said Dr. White.

“It doesn’t matter whether it’s a fish tag, pen ink, or energy storage materials — the ways we characterize materials and their properties are part of our toolkit and expertise. Training in materials research means you can be very flexible and tackle a wide range of problems.”

Source : Dalhousie University

New Theory on How Earth’s Crust Was Created

More than 90% of Earth’s continental crust is made up of silica-rich minerals, such as feldspar and quartz. But where did this silica-enriched material come from? And could it provide a clue in the search for life on other planets?

Conventional theory holds that all of the early Earth’s crustal ingredients were formed by volcanic activity. Now, however, McGill University earth scientists Don Baker and Kassandra Sofonio have published a theory with a novel twist: some of the chemical components of this material settled onto Earth’s early surface from the steamy atmosphere that prevailed at the time.

First, a bit of ancient geochemical history: Scientists believe that a Mars-sized planetoid plowed into the proto-Earth around 4.5 billion years ago, melting the Earth and turning it into an ocean of magma. In the wake of that impact – which also created enough debris to form the moon — the Earth’s surface gradually cooled until it was more or less solid. Baker’s new theory, like the conventional one, is based on that premise.

The atmosphere following that collision, however, consisted of high-temperature steam that dissolved rocks on the Earth’s immediate surface — “much like how sugar is dissolved in coffee,” Baker explains. This is where the new wrinkle comes in. “These dissolved minerals rose to the upper atmosphere and cooled off, and then these silicate materials that were dissolved at the surface would start to separate out and fall back to Earth in what we call a silicate rain.”

To test this theory, Baker and co-author Kassandra Sofonio, a McGill undergraduate research assistant, spent months developing a series of laboratory experiments designed to mimic the steamy conditions on early Earth. A mixture of bulk silicate earth materials and water was melted in air at 1,550 degrees Celsius, then ground to a powder. Small amounts of the powder, along with water, were then enclosed in gold palladium capsules, placed in a pressure vessel and heated to about 727 degrees Celsius and 100 times Earth’s surface pressure to simulate conditions in the Earth’s atmosphere about 1 million years after the moon-forming impact. After each experiment, samples were rapidly quenched and the material that had been dissolved in the high temperature steam analyzed.

The experiments were guided by other scientists’ previous experiments on rock-water interactions at high pressures, and by the McGill team’s own preliminary calculations, Baker notes. Even so, “we were surprised by the similarity of the dissolved silicate material produced by the experiments” to that found in the Earth’s crust.

Their resulting paper, published in the journal Earth and Planetary Science Letters, posits a new theory of “aerial metasomatism” -– a term coined by Sofonio to describe the process by which silica minerals condensed and fell back to earth over about a million years, producing some of the earliest rock specimens known today.

“Our experiment shows the chemistry of this process,” and could provide scientists with important clues as to which exoplanets might have the capacity to harbor life Baker says.

“This time in early Earth’s history is still really exciting,” he adds. “A lot of people think that life started very soon after these events that we’re talking about. This is setting up the stages for the Earth being ready to support life.”

Funding for the research was provided by an NSERC Discovery grant to Baker and an NSERC Summer Undergraduate Research Assistant grant to Sofonio.

Science for Sweet Tooths

Food scientists at the University of British Columbia have developed a faster and cheaper way to quantify antioxidant levels in chocolate. It’s a method they plan to use in new research to help uncover when antioxidant levels rise and fall during the manufacturing process, from raw cocoa beans to chocolate bars.

“Our method predicts the antioxidant levels in chocolate in under a minute, compared to the industry standard that can take several hours or even days,” said Xiaonan Lu, an assistant professor in food, nutrition and health in the faculty of land and food systems, who developed the method alongside PhD student Yaxi Hu. “It’s not a substitute for the traditional method used at the moment, but it does show a strong correlation for being just as reliable.”

The UBC method uses infrared spectroscopy, a technology that can be used to illuminate infrared light onto chocolate samples. The infrared spectra record the chemical composition of each sample, including the amount of polyphenols, micronutrients with high antioxidant properties. The traditional method relies on biochemical tests to read absorbance values and can be quite time consuming and expensive.

“Testing for antioxidant levels can give chocolatiers guidance on which cocoa beans to select, or how to improve their processing parameters,” said Hu.

Chocolate is made from cocoa beans and is manufactured through several processing stages, including drying, roasting and fermentation of the beans. The UBC food scientists have started to use their method to measure cocoa bean samples from around the world in each stage to determine when antioxidant levels are at their highest and lowest.

“If we identify drying as the step that significantly lowers the bean’s antioxidant properties, for example, we will want to develop a strategy to reduce the drying time, or drying temperature,” Lu said.

It could be considered incredibly valuable information for chocolate companies who want to make products high in antioxidants or appeal more to health-conscious consumers.

Antioxidants benefit human health and help contribute to the prevention of cancers, vision loss and heart diseases. Antioxidant compounds are commonly found in foods like pecans, blueberries and chocolate.

Lu and Hu’s research on cocoa beans is in its early stages as they test hundreds of samples. The method they developed to test for antioxidant levels was funded by a local chocolatier in Metro Vancouver, the Natural Sciences and Engineering Research Council (NSERC) and by the non-profit MITACS.

The UBC food scientists hope to attract additional funding, particularly from a major chocolate company, to further their studies.