News Category: News
DNA used to trace TB outbreak
B.C. scientists first to use gene sequencing
By Pamela Fayerman, Vancouver Sun February 24, 2011, p. A1
B.C. scientists pioneered the practice of combining DNA gene sequencing and social networking surveys when they traced the genesis and spread of a tuberculosis outbreak in Port Alberni.
The results let researchers pinpoint the TB outbreak to people congregating in crack cocaine houses and other squalid environments such as flop hotels, according to a study published Wednesday in The New England Journal of Medicine.
“When we did this in 2008, nobody in the world had ever used genome sequencing to investigate a bacterial outbreak, but I think it should be applied to everything now because you can learn so quickly how it started and how it’s spreading,” said lead author Jennifer Gardy, head of the genome research lab at the BC Centre for Disease Control (BCCDC).
Although the paper doesn’t outline the details, news reports at the time revealed the two-and-a-half year outbreak began in 2006 and affected 41 people -mostly aboriginals -in Port Alberni, including an infant and a child. Traditional contact tracing, in which public health nurses ask about family members and close contacts, did not identify the origin of the outbreak nor the sources of transmission. So investigators launched a gene sequencing effort to find the carriers and type the strains.
Those suspected of having active TB coughed up sputum that was placed in tubes and given a DNA “fingerprint.”
Investigators then conducted a detailed social network analysis in which they asked people to account for their time on a daily basis: where they went, what they did in those places and who they were with.
Gardy had high praise for the individuals, saying they were fully cooperative. While the same TB strain had been in the community since 1995, the sudden surge in cases suggested something sinister was going on. Gardy said some scientists thought the surge was perhaps caused by mutating strains while others were betting that there was a social, rather than a genetic trigger.
Researchers had an epiphany when an RCMP officer mentioned that crack cocaine had “come to town.” In a chart, the study’s scientists demonstrate how police files in the outbreak community mirrored the rise in the epidemic. Over a certain time period, there was a distinct correlation between arrests for cocaine possession and trafficking and cases of TB transmission.
TB was being transmitted in the crack houses, not through the pipes being shared to smoke the drug, but because people were coughing so much while spending hours together in poorly ventilated rooms.
Gardy said public health investigators learned that popular individuals in the community were “super-spreaders” who infected numerous others, which means researchers now make an effort to “find out who the popular people are, talk to them and target them for screening.”
“You have to build up trust and public health nurses are outstanding at that,” she said. “You don’t just hit people over the head with direct questions.”
The outbreak -which raised the annual incidence rate for the region by more than 10 times -was “nipped in the bud” and confined through successful antibiotic treatment of those infected. Of the 41 cases, most -85 per cent -were cured; one person did not complete treatment; another had a relapse; and four people died.
Of the four deaths, one was from TB complications, another from TB treatment side effects and two stemmed from unrelated causes -a car accident in one case and a drug overdose in another. Researchers followed the TB patients for at least one year.
Gardy said the study will help guide investigations into other kinds of disease outbreaks -viral or bacterial. Gene sequencing is a speedy way to detect and type disease and the costs of using it have fallen dramatically. It allows investigators to get accurate results and zero in on the highest risk groups and events where disease is spreading.
The $300,000 study was sponsored by grants from Genome B.C., Health Canada, Simon Fraser Community Trust, as well as grants from non-profit agencies like the BC Lung Association.
SCWIST member Dr. Adele Diamond delivers annual Pickering Lecture at Carleton University
Carleton Hosts Lecture on Training Your Brain
Dr. Adele Diamond, one of the founders of the field of Developmental Cognitive Neuroscience, will deliver the annual Pickering Lecture at Carleton University. She will be speaking on Training the Brain: Improving Attention and Self-regulation.
Dr. Diamond is the Canada Research Chair in Developmental Cognitive Neuroscience at the University of British Columbia and a fellow of the Royal Society of Canada. She is one of the world’s leading researchers on the development of the cognitive functions of the brain and, since 1980, has studied these functions from their earliest beginnings in infancy throughout peoples’ lifespans.
Dr. Diamond takes a “Yes You Can” approach to learning. By teaching a concept in new ways or posing questions differently, she believes a child who may have had previous difficulties can succeed.
Her research has shown that cognitive control abilities, such as selective attention and self-regulation, can be improved through training and practice. But they are particularly susceptible to stress, lack of sleep, loneliness or lack of exercise.
The lecture is free and open to the public. It takes place at 7 p.m. on Thursday, March 3 in Room 360 of the Tory Building at Carleton.
Bilingual infants can tell difference between languages they don’t know
By Gerry Bellett – Vancouver Sun – February 21, 2011, p. A8
Studies by a UBC psychology professor have shown that infants are just as capable of growing up bilingual as unilingual.
Psychologist Janet Werker’s joint findings with Prof. Nuria Sebastian-Galles of Barcelona University were presented Friday to the American Association for the Advancement of Science’s annual general meeting in Washington, D.C.
Their research of infants raised in homes where both Catalan and Spanish were spoken showed that infants at four, six and eight months old could discern different languages whereas monolingual infants who also had the ability to discern those languages at four and six months lost this ability by the time they were eight months old.
“Infants raised in households where Spanish and Catalan are spoken can discriminate between English and French just by watching people speak even though they have never been exposed to these languages before,” said Werker.
The infants who were part of the study were shown silent videos of talking faces speaking English and French and found that the bilingualexposed babies were able to distinguish between French and English simply through facial clues.
“These findings, together with our previous work on newborn infants, provide even stronger evidence that human infants are equally prepared to grow up bilingual as they are monolingual,” said Werker, Canada Research Chair in Psychology and director of UBC’s Infant Studies Centre.
“The task of language separation is something they are prepared to do from birth -with bilinguals increasingly adept over time.”
Professor Lenore Fahrig Receives Carleton Achievement Award for Innovative Research
Carleton professor Lenore Fahrig is one of 10 recipients of this year’s Carleton Research Achievement Awards that honour innovative researchers for their work that helps find solutions to real-world problems. The other nine are being announced during Carleton’s Research Days celebration that ends on Friday, Feb. 11.
Fahrig, a biology professor and wildlife ecologist, will be using the $15,000 honorarium to research how a variety of agricultural crops and their planting patterns affect birds, butterflies, syrrphid flies, bees, carabid beetles, spiders and plants in 100 one-square-kilometre agricultural landscapes throughout Eastern Ontario.
“Our ultimate goal is to create guidelines that will help inform farmers of best practices that they can use to protect biodiversity in agricultural landscapes,” says Fahrig.
This project is being funded by the Natural Sciences and Engineering Research Council and is supported by Environment Canada, Agriculture and Agri-Food Canada, Ontario Ministry of Agriculture Food and Rural Affairs, Food Alliance, Dairy Farmers of Canada and Organic Agriculture Centre of Canada.
Fahrig works with colleagues Doug King, Scott Mitchell and Kathryn Lindsay in the Geomatics and Landscape Ecology Facility for Research in Support of Species Conservation at Carleton (GLEL). Lindsay is an adjunct professor in Biology and Geography/Environmental Science at Carleton who works with Environment Canada. The GLEL was built in 2004 with funding from the Canada Foundation for Innovation, Ontario Innovation Trust, Carleton University, Environment Canada and the Hamlin Family Foundation.
In addition to her work on agricultural landscapes, Fahrig and her graduate students have spent the last 20 years identifying which wildlife species are most affected by roads and traffic, with the goal of influencing environmental policy and management.
“Many animals, even small ones such as amphibians, attempt to cross roads in the course of their normal movements,” points out Fahrig. “This is particularly dangerous for amphibians and reptiles which travel at a slow speed.”
Fahrig thinks a good solution to the problem is fencing to keep animals off roads, combined with wildlife overpasses. “But so far there is very little research to test whether wildlife populations are increasing as a result of these installations,” she notes.
“Delusions of Gender”: The bad science of brain sexism
Some studies claim that women are innately bad at math, and men are bad at empathy. Here’s why they’re wrong
By Thomas Rogers, Salon.com
Women’s brains are wired differently from men’s. It’s why so few women do well in math. It’s why women gravitate toward dolls and tea sets as young children, and why they’re so much better at understanding other people’s emotions. It’s why they’re so good at housework! (Men are more wired to focus on one task — like arithmetic.) At least that’s what a host of recent studies in the field of neuroscience have argued. Too bad they’re wrong.
In her new book, “Delusions of Gender: How Our Minds, Society, and Neurosexism Create Difference,” Cordelia Fine, a research associate and the author of “A Mind of Its Own” (also about brain science), discovers that, far from supporting the existence of vastly different male and female brains, much of the research on the topic is not only deeply flawed, but dangerously misleading. Women aren’t worse at math (as Fine proves in the book, bad neurological research is one of the reasons women are still struggling to catch up in the field), and girls’ preference for girlish toys probably has more to do with social expectations than what’s in their skulls. Fine’s book is a remarkably researched and dense work that, even while tackling highly complex subject manner, retains a light, breezy touch.
Salon spoke to Fine over the phone from Australia about the science of single-sex schooling, the message of “Revenge of the Nerds,” and why women aren’t really better than men at interpreting people’s feelings.
Why did you write this book?
It began when I read a parenting book that claimed that hard-wired sex differences meant that girls and boys should be parented and taught differently. When I looked at the actual studies being used as evidence, I was really shocked by how badly the neuroscientific findings were being misrepresented. I saw the same thing going on in other popular books about gender, and when I looked, I was surprised to discover how little convincing evidence there was that, for example, the male brain is hard-wired to be good at understanding the world and the female brain is hard-wired to understand people.
Why are people so intent on misrepresenting the differences between the male and female brain?
We look around in our society, and we want to explain whatever state of sex inequality we have. It’s more comfortable to attribute it to some internal difference between men and women than the idea that there must be something very unjust about our society. As long as there has been brain science there have been misguided explanations and justification for sex and inequality — that women’s skulls are the wrong shape, that their brain is too small, that their head is too unspecialized. It was once very cutting-edge to put a brain on a scale, and now we have cutting-edge research that is genuinely sophisticated and exciting, but we’re still very much at the beginning of our journey of understanding of how our brain creates the mind.
So women aren’t really more receptive than men to other people’s emotions?
There is a very common social perception that women are better at understanding other people’s thoughts and feelings. When you look at one of the most realistic tests of mind reading, you find that men and women are just as good at getting what their interaction partners were thinking and feeling. It even surprised the researchers. They went on to discover that once you make gender salient when you test these abilities [like having subjects check a box with their sex before a test], you have this self-fulfilling effect.
The idea that women are better at mind reading might be true in the sense that our environments often remind women they should be good at it and remind men they should be bad at it. But that doesn’t mean that men are worse at this kind of ability.
You write that one of the obstacles that women face in the field of math is something called “stereotype threat.” What is that?
It refers to the difficulty for people who belong to a group stereotypically seen as being not very good at a particular thing they’re trying to do. For a woman doing a math test, she has an acquired stereotype threat that if you do badly, people are going to judge you because you’re a woman and that you’re going to confirm what everyone already “knew,” that women are bad at math. It creates a whole host of harmful psychological effects in people’s minds. And psychologists have discovered if you make gender seem not relevant to a task, then men and women perform equally well. Right now, when it comes to women in traditional male domains, it’s like a track star running into a headwind — their performance is impeded.
But it seems like a Catch-22: Women who pursue careers in math are being handicapped by the fact that there are so few women pursuing careers in math.
Gender equality is increasing in pretty much all domains, and the psychological effects of that can only be beneficial. The real issue is when people in the popular media say things like, “Male brains are just better at this kind of stuff, and women’s brains are better at that kind of stuff.” When we say to women, “Look, men are better at math, but it’s because they work harder,” you don’t see the same harmful effects. But if you say, “Men are better at math genetically,” then you do. These stem from the implicit assumption that the gender stereotypes are based on hard-wired truths.
Some people use neuroscience to argue that girls and boys learn differently and to advocate for single-sex education. Are you opposed to single-sex schooling?
I’m not against single-sex schooling, but I’m very concerned about neuroscientific data being used to make the case for it. The findings are not yet fully understood. We don’t, for example, really know what it means for the right prefrontal cortex to fire a bit more in a test. Brain scientists understand that, but there’s nothing to prevent popular writers from seizing on this as evidence that males and females are hard-wired to feel and think differently, so they should be taught math in this way and English in that way.
In the book you track the evolution of the computer nerd in popular culture. Ever since movies like “Revenge of the Nerds,” we have this idea that computer scientists are geeky men, which as you point out in the book, can be alienating to some people.
Initially computer science was dominated by women, and cross-culturally there are places in the world where, until recently, computer science was dominated by women. But now, in the U.S., the stereotype of the male computer science nerd can be off-putting to women. It’s very easy to assume that the characteristics you see [in the portrayal of] your profession are necessary for you to participate in it, but that might not necessarily be the case.
Parents who try to raise children in gender-neutral environments are often horrified when, despite their best intentions, their daughters are drawn to Barbies and their sons are drawn to violent toys. If there are no hard-wired differences between the sexes, why does this happen?
I spend a lot of time with parents, and you see egalitarian-minded parents try hard to rear their children in a non-gendered way. Then you see their children defy them. The fact is, babies are born into a world in which sex is the most important and obvious social division. It’s constantly emphasized through segregation, through dress and so forth. Babies are born to parents who have a host of assumptions and expectations about gender, whether or not they consciously endorse those expectations. Studies have shown that parents have a tendency to see boys as more boyish and girls as more girlish than they actually are.
Once the children reach the age of 2, which is the age they discover which side of this gender divide they’re on, all bets are off. Parents may prefer that girls not play with Barbies and boys not play with guns, but by that age children know what tribe they belong to, and will want to be part of it.
Carleton Professor Maria DeRosa Honoured With 2011 Research Achievement Award For Work on Biosensors
For the millions of people worldwide who suffer from psychiatric and neurodegenerative diseases such as Parkinson’s disease and schizophrenia, Carleton Professor Maria DeRosa’s next research initiative provides hope for a new treatment.
DeRosa is one of 10 Carleton professors who will be honoured with a Research Achievement Award from the university for her innovative research that helps find solutions to real-world problems. The other winners will be announced throughout Carleton’s Research Days celebration that runs until Feb. 11.
DeRosa has won major awards for her research that looks at how single-stranded pieces of synthetic DNA called aptamers can be used to combat everything from diseases to environmental contaminants.
“Aptamers act like antibodies, but with the added advantages of being more chemically robust, less expensive to generate and more easily modified for a range of applications, including medicine,” says DeRosa.
She plans on using the $15,000 honorarium from her Carleton award to develop a DNA aptamer for the neurotransmitter dopamine and generate a strategy to deliver this aptamer across the blood-brain barrier. Dopamine helps to regulate motor behaviour, emotion, motivation, reward, memory and learning. This work will be done in collaboration with Carleton neuroscience Professor Matthew Holahan.
“We know that functional abnormalities have been implicated in various psychiatric and neurodegenerative diseases, most commonly, Parkinson’s disease and schizophrenia,” says DeRosa. “For these reasons, dopamine is a high-priority target for the development of an aptamer for biosensing and therapeutics. In the short term, this work will provide innovative new tools for studying the brain at the molecular level. In the long term, this research may serve as the underpinning for a drug discovery program with the potential to produce novel aptamer-based therapeutics for a variety of mental health conditions.”
DeRosa is a Carleton alumna and part of a group of chemists working in the emerging field of nanoscience and nanotechnology. Most recently, some of her students won the Dance Your PhD competition sponsored by the prestigious journal Science.
“Helping people” attracts women to science and engineering
“Across the globe, women make up more than half the world’s population. And at UBC, women make up just over half of the undergraduate population.
So why is it that only 18 percent of UBC Engineering undergraduates are women? And why, after graduation, do attrition rates for women in engineering and high- technology careers soar as high as 40 percent?
SCWIST member and Mechanical Engineering Professor Elizabeth Croft has some ideas.
Recently named the NSERC Chair for Women in Science and Engineering for the British Columbia and Yukon region, Croft’s focus will be on increasing the participation of women in science and engineering and providing role models for women active in and considering careers in these fields.
In other parts of the world, such as Eastern Europe and South America, women represent roughly 50 percent of the student body in these fields. To start, says Croft, North American institutions need to address and change young women’s perceptions that it’s not “normal or cool” to study engineering.
Croft also acknowledges differences in how young men and women approach career choices. For example, women are typically drawn to what they perceive as helping” professions. To many young women, engineering doesn’t obviously fit into that category, observes Croft, despite the fact that engineers envision, design and build the medical, environmental and consumer technologies that help people live healthier, greener and more connected lives.
Croft integrates community-service learning in curricula so students immediately recognize via hands-on experience how their skills and knowledge benefit others. This fall, 130 students earned credits while working on community and industry projects. The experience connects what students learn in the classroom with the impact it makes on their community.
“There is great demand for highly trained scientists and engineers to sustain economic development, and we need to attract and foster a diverse talent pool with a global perspective,” says Croft. ‘We cannot truly succeed as a profession—and, ultimately, a society—if we do not have the opportunity to attract and retain the brightest minds, male or female.”
To support workplace change, Croft is partnering with industry and existing networks for women in science and technology. She aims to help the traditional technical workplace find ways to accommodate the nonlinear trajectory for employees who may need flexibility to raise families, care for aging parents or nurture personal growth.
“This may end up benefiting all workers,” says Croft. Croft has spearheaded several initiatives to support women in engineering, including UBC’s Engineering’s Mentoring (formerly Tri-mentoring) Program, which connects students with engineering professionals, provides a sense of community and support and can help reduce feelings of isolation while increasing self-confidence. She also co-founded UBC’s Women in Engineering program, which organizes speakers, brown-bag socials and a retreat.
“Gender or ethnicity should not inhibit people from pursuing a career in which they can truly make a difference in our world,” says Dean Tyseer Aboulnasr.
‘With NSERC and industry support, coupled with Croft’s leadership, we will continue to build an inclusive and diverse community and work to inspire a new generation of professionals. Our future depends upon engineers and scientists who will develop the technology necessary to address the challenges facing us all. It only makes sense that those engineers and scientists reflect the diversity of our society,” she says.
NSERC contributed $350,000 in support of the chair for five years, with industry sponsors contributing matching funds.
Lead sponsors include BC Hydro, Dr. Ken Spencer (BASc ‘67, PhD ‘72), WorleyParsons Canada Ltd., Teck Resources Limited., Stantec Consulting, and Henry F. Man (BASc ‘83).
Contributing sponsors are Ms. Catherine Roome, Mr. Stanley Cowdell (BASc ‘73), the APEGBC Division for Advancement of Women in Engineering and Geoscience, Nemetz (S/A) & Associates Ltd., and Glotman Simpson Consulting Engineers. Karen Savage, P.Eng (BASc ‘86), and Golder Associates Ltd. have also supported the chair..
INGENUITY Fall 2010 / Winter 2011 p. 17
Brain research may head off major stroke
Numbness, vision change could signal greater damage
By Randy Shore, Vancouver Sun, January 28, 2011, p. A1
Scientists at the Brain Research Centre at UBC Hospital are using deep-brain stimulation to peer into the brains of people who have experienced temporary numbness or vision changes and finding far more damage than previously thought.
The researchers hope to use their technique to identify patients with the most damage from so-called transient ischemic attacks (TIA) for aggressive treatment to head off a major stroke.
In a study published Thursday in the journal Stroke, neuroscientist Lara Boyd and her colleagues revealed that people who have had transient ischemic attacks suffer lasting damage to their brains that is not detected by conventional brain scans. A TIA is an episode of sudden numbness, vision loss or difficulty speaking that disappears within 24 hours.
“The assumption has been made that these attacks are temporary and because the overt symptoms go away that there is no lasting damage,” said Boyd. “When you do an MRI [magnetic resonance imaging] more often than not you don’t see anything.”
Boyd and her colleagues used transcranial magnetic stimulation—a device used to help heal the brains of stroke victims with pulses of energy—to create patterns of excitation that expose the damaged areas deep within the brains of people who have experienced a TIA. The researchers then compare responses from the affected side of the brain with those from the unaffected side.
“It is much harder to elicit a response from the affected side of the brain and that is a hallmark of brain damage,” she explained. “It’s eerily similar to what you see after an actual stroke.”
The researchers believe the effects of a transient ischemic attack are not transient at all. “We aren’t sure if the brain ever recovers,” said Boyd.
People who suffer a TIA are at much higher risk of stroke within 30 to 60 days and those with the most damage as measured by the asymmetric responses of their brain hemispheres are likely at the highest risk of suffering a stroke, Boyd said.
“We really want to be able to say that of 10 people who have had a TIA, these are the ones we are most worried about,” she said. “Then we can prioritize clinical intervention.”
Boyd’s group also received news this week of a $350,000 grant to continue their work from the Canadian Institutes for Health Research. The research is a joint effort of the University of B.C. and Vancouver Coastal Health.
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WHAT IS A TRANSIENT ISCHEMIC ATTACK?
Symptoms of TIA can include sudden loss of vision or a change in vision, numbness or difficulty speaking. Symptoms may last only a few hours.
“People think that if it goes away after an hour or two or they wake up the morning and feel better that it is transient and they ignore it,” said Boyd.
Having a TIA indicates a high risk of stroke.
“A TIA is a medical emergency, even if it is transient, you need to get checked by a doctor.”
Carleton Students and Professors head to Antarctica for an ‘Anything But Textbook’ Experience
Seven Carleton University students will be earning course credits next month while conducting research on the Earth’s southernmost continent.
The students and their instructors, Claudia Schroder-Adams and Natalia Rybczynski, will travel to Antarctica Feb. 12 to 28 as part of the Students on Ice program.
Led by Canadian adventurer, environmentalist and educator Geoff Green, the program provides participants with a unique educational opportunity that allows them to visit some of the world’s most wild and awe-inspiring ecosystems in order to experience a transformative connection with nature – a connection that changes the way they understand and act in the world. Green has already travelled to Antarctica 80 times.
“A lot of tourists head to Antarctica for a sightseeing adventure, but this is not going to be a show-and-tell holiday for our students,” says Prof. Schroder-Adams. “It’s an opportunity to do serious scientific research while gaining hands-on experience in a very fragile ecosystem.”
“The polar regions are ‘ground zero’ for climate change as they are the most sensitive areas for global warming,” notes Rybczynski, an adjunct professor in earth sciences and biology and Carleton alumna. “Our students will be able to see this pattern first-hand while learning more about the causes and consequences of climate change by studying the geological record in Antarctica.”
The field work is part of the coursework for three courses at Carleton that focus on the origin and evolution of Antarctica ecosystems over time. Of the seven students taking the undergraduate and graduate courses, six are earth sciences students while one is neuroscience. Three are undergraduates. The other four graduate students also conducted their research in the Canadian Arctic, making them pole-to-pole adventurers.
“I was very lucky to be part of a research expedition to the Canadian High Arctic last summer, an opportunity that very few people get to experience,” says grad student Thomas Cullen. “The chance I have been given to visit the Antarctic as part of my Carleton coursework, and see both poles in the period of a year, is an extraordinary experience I will remember for the rest of my life.”
The group will fly to Ushuaia, a picturesque community at the southern tip of Argentina, and then board MV Ushuaia, a 3,000-tonne, ice-strengthened vessel outfitted for supply and oceanographic research. They will be joined by students and staff from elsewhere in Canada, the United States, Australia, New Zealand, India, Kuwait, United Kingdom, Spain, Norway, Sweden, France and Argentina.
While on board, expeditioners will conduct scientific research such as taking ocean water and sediment samples, as well as attend lectures and workshops. Daily trips by Zodiac to the mainland will facilitate hands-on studies of rocks, fossils, ice and ecological habitats.
Rybczynski, who is also a research scientist and fossil mammal specialist with the Canadian Museum of Nature, along with Schroder-Adams, a micropaleontologist, are also hoping to visit Seymour Island, one of the few sites in the world where the Cretaceous/Tertiary boundary is exposed, documenting the mass extinction that brought the dinosaur era to an end. This expedition is one of many research and educational collaborations between Carleton and the museum. Other ongoing collaborative projects include the undergraduate program in vertebrate paleontology, graduate supervision, summer student internships in the museum’s mineralogy and gemology collections and provision of valued collection material for student research.
A total of $36,000 has been generously donated in support of Carleton students’ participation in this initiative by the Gainey Foundation and two Carleton alumni, Jim Sullivan and JC Potvin. Sullivan and Potvin are both proud graduates of Carleton’s Department of Earth Sciences.
“The Students on Ice program is a unique, hands-on approach to environmental education,” says Anna Gainey, executive director of the Foundation. “The Gainey Foundation is proud to help to make this exceptional research opportunity available to Carleton students.”
Additional funds have been provided by the office of the provost, vice-president (Research and International) and the dean of the Faculty of Science. The students are busy fundraising to cover their remaining travel expenses.
Canadian astronomer’s work will lead to better map of the universe
By Randy Boswell – Vancouver Sun – January 18, 2011, p. B4
A Canadian-led study of the distinctive, pulsating stars that astronomers use to calculate vast distances across galaxies is forcing a rethink of these “standard candles” and should lead to more accurate measurements of the key attributes of the universe—including its size, age and rate of expansion.
University of Western Ontario astronomer Pauline Barmby told Postmedia News that her team’s analysis of new images from NASA’s Spitzer space telescope show that the ebb-and-flow glow of so-called “Cepheid” stars—deemed indispensable in understanding the scale of the cosmos—can be altered through the erosion of their constituent plasma, gas and dust as the great balls of energy hurtle through space.
That means distance calculations based on Cepheid stars—winking lights long used for a measurement constant known as standard candles—will now need to account for estimated losses of the stellar material they’re made from.
“Everything crumbles in cosmology studies if you don’t start up with the most precise measurements of Cepheids possible,” Barmby says in a summary of the team’s findings.
“This discovery will allow us to better understand these stars, and use them as ever more precise distance indicators.”
The team’s research paper, published in the latest issue of the Astronomical Journal, was co-authored by astrophysicist Douglas Welch of McMaster University in Hamilton, Ont., and five other scientists from Italy and the U.S.
The discovery promises to help astronomers fine-tune the “cosmic distance ladder” that uses Cepheid stars like rungs to climb from one location in space to farther and farther locations, with the length of each galactic step measured accordingly.
“When we look at a star in the sky, we don’t have any obvious way of telling whether that’s far away from us but putting out a lot of energy, or a star close to us that’s putting out a little energy,” Barmby said.
“What’s special about this particular kind of star is that they pulsate, and the pulsation period—how long it takes them to get bright and dim again—is directly related to their luminosity.”
Knowing luminosity, or how much energy a star is putting out with each pulse, allows scientists to figure out, in effect, “whether it’s a 100-watt or a 40-watt bulb,” says Barmby—and once astronomers have that information, “you’ve got a distance.”
Positive Mood Seems to Boost Creativity
HealthDay News, Bloomberg Businessweek, December 20, 2010
People who are seeking creative inspiration should try to look on the bright side, the results of a new study suggest.
Canadian researchers used happy or sad video and music clips to put participants into different moods and then had them learn to classify sets of pictures with visually complex patterns.
People in a happy mood were better able to learn a rule to classify the patterns than those with sad or neutral moods, said Ruby Nadler, a graduate student at the University of Western Ontario, and colleagues.
The happy music used in the study was a lively Mozart piece, while the happy video featured a laughing baby. The sad music was from the movie Schindler’s List, and the sad video was from a news report about an earthquake.
“If you have a project where you want to think innovatively, or you have a problem to carefully consider, being in a positive mood can help you to do that,” Nadler said in an Association for Psychological Science news release.
The findings, published in the December 15 issue of the journal Psychological Science, may explain why some people watch funny videos on their computers at work.
“I think people are unconsciously trying to put themselves in a positive mood,” Nadler suggested.
Ruby Nadler is a third-year Ph.D. student in Cognitive Psychology at The University of Western Ontario. She is investigating how regulatory focus and regulatory fit influence cognitive processing. She is also interested in how affective states influence category learning.
New Brunswick girl youngest astronomer to discover supernova
Ten-year-old was assisted by her father, who once held the record
By Tobi Cohen – Vancouver Sun – January 4, 2011, p. B3
Kathryn Aurora Gray is taking her new celebrity in stride after becoming the youngest person ever to discover a supernova.
The 10-year-old Fredericton girl’s phone has been ringing off the hook ever since the Royal Astronomical Society of Canada announced her find Monday.
But the amateur astronomer knows—better than anybody, perhaps—that her discovery is fleeting. “It’s just a blowing-up of stars so eventually it will fade away,” she said of the supernova. “I was very excited to find one. Especially this quick.”
Kathryn made the discovery over the weekend under the supervision of her father Paul Gray and with help from family friend David Lane, longtime astronomy enthusiasts who were co-credited with the find.
According to the society, the trio spotted a magnitude 17 supernova in galaxy UGC 3378 in the constellation Camelopardalis, about 240 million light years away.
Supernovas are stellar explosions caused by the violent death of massive stars that are far bigger than the Earth’s sun and emit a bright light that fades over several weeks.
Lane collected the images with a telescope in Halifax on New Year’s Eve and sent them over to the Grays, who began examining them on Sunday using computer software that allows users to lay new images on top of old ones and click between them to look for differences. Kathryn said they quickly ruled out “noise” on the photograph and contacted a third party to take another photo in order to rule out a comet or asteroid.
“We sent the email off and then they made sure no one else had discovered it before and then they made an announcement.”
While this is Paul Gray’s seventh supernova—he found his first in 1995 at age 22, making him the youngest person at that time to spot one—he had more or less abandoned his supernova-finding hobby to take up stellar photography until his daughter said that she wanted to give it a try. She spotted it 15 minutes into looking at her first images.
Wed Feb 01
