Patchen Barss / en Groundbreakers: 茄子直播 initiative brings together experts to address major societal issues /news/groundbreakers-u-t-initiative-brings-together-experts-address-major-societal-issues <span class="field field--name-title field--type-string field--label-hidden">Groundbreakers: 茄子直播 initiative brings together experts to address major societal issues</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/Goldie_Nejat_AGEWELL_UofT_Robotics_Institute-crop.jpg?h=afdc3185&amp;itok=mAd8-Kmr 370w, /sites/default/files/styles/news_banner_740/public/Goldie_Nejat_AGEWELL_UofT_Robotics_Institute-crop.jpg?h=afdc3185&amp;itok=ULWqfDGt 740w, /sites/default/files/styles/news_banner_1110/public/Goldie_Nejat_AGEWELL_UofT_Robotics_Institute-crop.jpg?h=afdc3185&amp;itok=d_UXRSfA 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/Goldie_Nejat_AGEWELL_UofT_Robotics_Institute-crop.jpg?h=afdc3185&amp;itok=mAd8-Kmr" alt="Goldie Nejat poses with her robots at the robotics institute"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2021-09-02T15:45:14-04:00" title="Thursday, September 2, 2021 - 15:45" class="datetime">Thu, 09/02/2021 - 15:45</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">An expert in assistive robotics, Goldie Nejat works with a diverse group of researchers at 茄子直播's Robotics Institute, one of several Institutional Strategic Initiatives, to build machines that can help seniors (photo courtesy of Goldie Nejat)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/our-community" hreflang="en">Our Community</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/groundbreakers" hreflang="en">Groundbreakers</a></div> <div class="field__item"><a href="/news/tags/institutional-strategic-initiatives" hreflang="en">Institutional Strategic Initiatives</a></div> <div class="field__item"><a href="/news/tags/temerty-faculty-medicine" hreflang="en">Temerty Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/black" hreflang="en">Black</a></div> <div class="field__item"><a href="/news/tags/faculty-applied-science-engineering" hreflang="en">Faculty of Applied Science &amp; Engineering</a></div> <div class="field__item"><a href="/news/tags/molecular-genetics" hreflang="en">Molecular Genetics</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> <div class="field__item"><a href="/news/tags/robotics" hreflang="en">Robotics</a></div> <div class="field__item"><a href="/news/tags/u-t-mississauga" hreflang="en">茄子直播 Mississauga</a></div> <div class="field__item"><a href="/news/tags/u-t-scarborough" hreflang="en">茄子直播 Scarborough</a></div> <div class="field__item"><a href="/news/tags/women-and-gender-studies" hreflang="en">Women and Gender Studies</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p><b>Goldie Nejat</b>&nbsp;envisions a world where growing old is improved by robots that care.</p> <p>The Canada Research Chair in Robots for Society and professor of mechanical engineering in the University of Toronto鈥檚 Faculty of Applied Science &amp; Engineering is an expert in assistive robotics 鈥 machines that provide care,&nbsp;interventions and&nbsp;even companionship&nbsp;for long-term care residents and people&nbsp;living&nbsp;with dementia and other&nbsp;cognitive and physical impairments.</p> <p>The work is extraordinarily complex. In addition to engineering and artificial intelligence, creating robotic companions for an aging population often requires expertise in gerontology, cognitive neuroscience and medicine 鈥 even ethics.</p> <p>Enter the Robotics Institute. Part of&nbsp;<a href="https://isi.utoronto.ca/">茄子直播鈥檚 Institutional Strategic Initiatives (ISI) program</a>, the institute brings together top experts in different fields 鈥 from hardware design to public policy 鈥 to solve thorny, robotics-related problems in applications ranging from health care and transportation to manufacturing and logistics.</p> <p>鈥淏eing at 茄子直播, you have&nbsp;access to world-class researchers,鈥 says Nejat. 鈥淓very time I want to&nbsp;find&nbsp;a collaborator with specific&nbsp;expertise and&nbsp;knowledge, it's really easy.</p> <p>鈥淎 lot of us [robotics engineers] work with surgeons, doctors, physiotherapists, occupational therapists 鈥 you name it.鈥</p> <p>The Robotics Institute is&nbsp;<a href="https://isi.utoronto.ca/institutional-strategic-initiatives-are-cross-divisional-research-networks-pursuing-grand-challenges-and-bold-ideas-that-require-true-collaboration-and-the-integration-of-various-disciplinary-research/initiatives/">just one of nearly two dozen institutional strategic initiatives launched by 茄子直播</a>&nbsp;to address complex, real-world challenges that cut across fields of expertise. Each initiative brings together a flexible, multidisciplinary team of researchers, students and partners from industry, government and the community to take on a 鈥済rand challenge.鈥</p> <p>鈥淭he goal is to bring scientists, researchers and the broader research community together to achieve something that no one scientist or scientists from a single discipline could achieve on their own,鈥 says&nbsp;<b>Christine Allen</b>, 茄子直播鈥檚 associate vice-president and vice-provost, strategic initiatives.</p> <p>鈥淲hether they鈥檙e designing a new cancer treatment, developing more sustainable building materials, identifying better education systems for students with mental health issues, ISI participants are always exploring who can contribute 鈥 and who can benefit.</p> <p>鈥淐ross-divisional research and collaboration is paramount to addressing complex questions and making an urgently needed transformational impact.鈥</p> <p><img alt src="/sites/default/files/UofT5552_Goldie-crop.jpg" style="width: 750px; height: 500px;"></p> <p><em>鈥淎 lot of us [robotics engineers] work with surgeons, doctors, physiotherapists, occupational therapists 鈥 you name it,鈥 Nejat says&nbsp;(photo by University of Toronto)</em></p> <p>The approach marks a departure from the traditional university model of loosely affiliated, but independent 鈥 and relatively siloed 鈥 faculties, departments, institutes and colleges. The problem, Allen says, is that modern societal challenges don鈥檛 map very well onto traditional university structures. Climate change, mental health, systemic racism, artificial intelligence and many other issues are so multifaceted and interconnected that they can only be addressed with diverse expertise, insights, and approaches.</p> <p>The ISI approach, by contrast, seeks to take advantage of 茄子直播鈥檚 size and breadth of expertise by creating research networks that cut across campuses and disciplines as varied as sociology and computer science 鈥 all in an effort to unlock answers to challenging problems and create new knowledge.</p> <p>The Black Research Network, for instance, uses ISI鈥檚 multidisciplinary approach to help redress the sense of isolation that many Black faculty members feel by connecting them not only to each other, but also to the broader community 鈥&nbsp;and resources 鈥&nbsp;at the university.</p> <p>鈥淢y work is to make sure the right conversations are happening, that the right clusters are coming together to produce small and large-scale research grants and teams,鈥 says&nbsp;<b>Beth Coleman</b>, an associate professor of data and cities at 茄子直播 Mississauga鈥檚 Institute of Communication, Culture, Information and Technology and the Faculty of Information, and the network鈥檚 director. 鈥淚n STEM fields especially, the number of Black professors is small and people tend to be really isolated.</p> <p>鈥淭hat isolation is part of why people succeed or don鈥檛 succeed. Some of that has to do with how comfortable you feel and how invited you feel.鈥</p> <p>The co-founders of the network come from across the university:&nbsp;<b>Rhonda McEwen</b>, dean of 茄子直播 Mississauga;&nbsp;<b>Maydianne Andrade</b>, a professor of evolutionary biology and 茄子直播 Scarborough鈥檚 vice-dean of faculty affairs, equity and success;&nbsp;<b>Lisa Robinson</b>, associate dean, inclusion and diversity in the Temerty Faculty of Medicine, and&nbsp;<b>Alissa Trotz</b>, director of the Women &amp; Gender Studies Institute.</p> <p><img alt src="/sites/default/files/groundbreaks%20copy.jpg" style="width: 750px; height: 500px;"></p> <p><em>The co-founders of the Black Research Network are (clockwise from top left): Professors Maydianne Andrade, Lisa Robinson, Alissa Trotz and Rhonda McEwen (photos by Dylan Toombs, Temerty Faculty of Medicine, Geoffrey Vendeville and Nick Iwanyshyn)</em></p> <p>鈥淵ou have four incredibly fierce and important Black women researchers moving us towards a thriving research culture,鈥 says Coleman. 鈥淲ith their leadership, and with the university endorsing the Black Research Network as a strategic initiative, it makes it about more than addressing inequality and anti-Black racism 鈥&nbsp;it鈥檚 also about shining a light on excellence through a directed, applied and resourced program.鈥</p> <p>While the Black Lives Matter movement has recently put racism at the top of the daily news, the broad scope of the ISI initiative helps ensure that the Black Research Network can continue to make systemic change long after the news cycle has moved on.</p> <p>The same goes for the work of the Emerging and Pandemic Infections Consortium, another ISI project.</p> <p>鈥淲e don't want everyone to look away from infectious disease once the current pandemic recedes,鈥 says&nbsp;<b>Scott Gray-Owen</b>, a professor of molecular genetics in the Temerty Faculty of Medicine who is director of the consortium. 鈥淭here will be other pandemics, as well as more localized epidemics around the world. Toronto is a hub for transport and travel and is home to such an international community of people.</p> <p>鈥淣ot only does that mean we鈥檙e likely to be affected, but we鈥檙e also a natural place to prepare to respond better next time.鈥</p> <p><img alt src="/sites/default/files/UofT86168_0714ScottGrayOwen002-crop.jpg" style="width: 750px; height: 500px;"></p> <p><em>Scott Gray-Owen, a professor of molecular genetics in the Temerty Faculty of Medicine, is the director of the Emerging and Pandemic Infections Consortium&nbsp;(photo by Nick Iwanyshyn)</em></p> <p>The consortium fosters innovative approaches to combatting infections through microbial biology, immunity and disease progression alongside the politics, economics and social impact of pandemic preparedness, prevention and mitigation.</p> <p>鈥淵ou鈥檙e trying to move society to a place where it actually prepares for something in advance,鈥 Gray-Owen says. 鈥淎nd that is a very different type of challenge from just understanding microbial mechanisms.鈥</p> <p>茄子直播 has already created almost two dozen ISI projects, with more on the way. Each has its own structure and composition, but all take an evolved, advanced approach to mixing disciplines.</p> <p>鈥淚nterdisciplinarity used to mean people would look at the same problem from different directions. That鈥檚 important and powerful, but we鈥檙e trying to deepen that integration. We鈥檙e all coming together&nbsp;to see how we can contribute to solving a problem,鈥 Gray-Owen says. 鈥淲e have experts around the table who are internationally renowned for their contribution to cancer or autoimmune diseases or surface decontamination. 鈥淭he egos just go away, and new ideas come from that conversation.鈥</p> <p>ISI projects also look beyond senior faculty and established scholars to engage students, government funders and policy-makers, commercial enterprises, not-for-profits, Indigenous groups, activists, citizen scientists, the media and the general public. The ISI networks typically also include training, mentoring and public education, which increases the impact of the research.</p> <p>The programs aim to not only attract talent, but also grow it. Nejat, for one, says the openness of the ISI approach not only makes the research better, but it also helps ensure that the ideas that emerge have a positive impact in broader society.</p> <p>鈥淲e've been very lucky to have a lot of interest in robotics from people who have never, ever dealt with the technology 鈥&nbsp;people who come up with new research programs [related to robotics] that focus on the potential impact on society from a sociological or psychological point of view.</p> <p>鈥淚t's really interesting to see them helping us pave that way into the future.鈥</p> <p><i>This is the first article <a href="/news/tags/groundbreakers">in a series</a> about 茄子直播鈥檚 Institutional Strategic Initiatives program 鈥 which seeks to make life-changing advancements in everything from infectious diseases to social justice 鈥 and the research community that鈥檚 driving it.</i></p> <p>&nbsp;</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 02 Sep 2021 19:45:14 +0000 Christopher.Sorensen 170133 at Climate change slows reduction of methylmercury levels in Arctic: 茄子直播 researchers /news/climate-change-slows-reduction-methylmercury-levels-arctic-u-t-study <span class="field field--name-title field--type-string field--label-hidden">Climate change slows reduction of methylmercury levels in Arctic: 茄子直播 researchers</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/Lehnherr-Hazen-4-crop.jpg?h=afdc3185&amp;itok=4JOVx5zl 370w, /sites/default/files/styles/news_banner_740/public/Lehnherr-Hazen-4-crop.jpg?h=afdc3185&amp;itok=LzQSxypz 740w, /sites/default/files/styles/news_banner_1110/public/Lehnherr-Hazen-4-crop.jpg?h=afdc3185&amp;itok=Zu69CSIX 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/Lehnherr-Hazen-4-crop.jpg?h=afdc3185&amp;itok=4JOVx5zl" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2021-02-19T13:31:22-05:00" title="Friday, February 19, 2021 - 13:31" class="datetime">Fri, 02/19/2021 - 13:31</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">Igor Lehnherr, a researcher at 茄子直播 Mississauga, assessed the build-up of methylmercury, a dangerous neurotoxin, in Lake Hazen, one of Canada鈥檚 northernmost lakes (photo by Igor Lehnherr)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/arctic" hreflang="en">Arctic</a></div> <div class="field__item"><a href="/news/tags/geography" hreflang="en">Geography</a></div> <div class="field__item"><a href="/news/tags/mercury" hreflang="en">Mercury</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> <div class="field__item"><a href="/news/tags/sustainability" hreflang="en">Sustainability</a></div> <div class="field__item"><a href="/news/tags/u-t-mississauga" hreflang="en">茄子直播 Mississauga</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Climate change&nbsp;may be slowing the reduction of methylmercury&nbsp;鈥&nbsp;a dangerous organic neurotoxin created&nbsp;by microbes that metabolize mercury&nbsp;鈥&nbsp;in Arctic waters despite&nbsp;a global movement to reduce industrial mercury emissions.</p> <p>That is among the findings of&nbsp;<strong>Igor Lehnherr</strong>&nbsp;and his research team at the University of Toronto&nbsp;after assessing the build-up of methylmercury&nbsp;in Lake Hazen, one of Canada鈥檚 northernmost lakes.</p> <p>The study is&nbsp;<a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.0c05051">published in the journal&nbsp;</a><em><a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.0c05051">Environmental Science &amp; Technology</a>.</em></p> <p>鈥淢ercury pollution has gone down in the atmosphere,鈥&nbsp;says Lehnherr, an assistant professor of geography at 茄子直播 Mississauga. 鈥淲e鈥檙e doing things to tackle it, but climate change is throwing things for a loop [because] it can actually undo some of the benefits from emission reductions.鈥</p> <p>Methylmercury levels rise only indirectly from human activity. Burning fossil fuels, mining and other&nbsp;industrial processes release unmethylated mercury into the atmosphere. As the mercury settles into aquatic ecosystems, certain types of microbes metabolize it to form the much more dangerous methylmercury.</p> <p>A 鈥減ersistent organic pollutant,鈥 Methylmercury&nbsp;becomes more concentrated as it moves up the food chain 鈥 from bacteria to fish, predators and people. It affects the nervous system and can also cause cardiovascular damage. The toxin is especially dangerous for pregnant women&nbsp;and for fetuses, babies&nbsp;and young children whose nervous systems are still developing.&nbsp;</p> <p>While the area where the 茄子直播&nbsp;team collected samples is not close to any northern communities, Lehnherr says the work is relevant for Indigenous people who hunt and fish for food.</p> <p>鈥淲hat we鈥檙e learning is not constrained to that location,鈥 he says. 鈥淲e put a lot of import on understanding mechanisms that affect methylmercury, so we can apply what we learn in one place somewhere else.鈥</p> <p><img class="migrated-asset" src="/sites/default/files/lehnherr-field-crop.jpg" alt></p> <p><em>Igor Lehnherr,&nbsp;an assistant professor of geography at 茄子直播 Mississauga, says the field work for his latest study spanned several seasons and involved collaboration with other research teams in order to expand sampling&nbsp;(photo by Igor Lehnherr)</em></p> <p>Arctic methylmercury levels depend on a complex mix of factors, including industrial emissions, precipitation patterns, microbial numbers and activity, as well as changes in seasonal sea ice. The complexity, along with the remoteness of northern ecosystems, make Lehnherr鈥檚 work particularly challenging.</p> <p>鈥淭he field work spanned a few seasons,鈥 he says of his latest study. 鈥淪ome years we were there in the spring when it鈥檚 all snow and ice cover, some years in the summer, some years for both. By combining efforts with other teams, we expanded the sampling. Arctic research by nature is fairly collaborative 鈥&nbsp;we share costs, time&nbsp;and ideas.鈥</p> <p><img class="migrated-asset" src="/sites/default/files/Lehnherr-Hazen-3-crop.jpg" alt></p> <p><em>Igor Lehnherr and his research team take water samples through the ice (photo by Igor Lehnherr)</em></p> <p>In general, methylmercury-producing microbes are more active in warmer environments, implying a direct correlation between global warming and increased toxicity. But climate change also has many other effects that can exacerbate, mitigate&nbsp;and further complicate the situation.</p> <p>鈥淭emperature in the Arctic also controls permafrost thaw. It affects&nbsp;the amount of precipitation by controlling cloud cover, sea ice cover, rates of evaporation and these kinds of things,鈥 Lehnherr says.</p> <p>Changing weather patterns also affect how much methylmercury builds up in specific isolated areas and how efficiently it flows from one lake to the next, creating more widespread problems. In the short term, Lehnherr says it looks as though reduced emissions have not fully translated into cleaner Arctic ecosystems. However, Lehnherr says it should not necessarily be interpreted as a sign that efforts to reduce mercury aren鈥檛 worth it.</p> <p>鈥淚 mostly think it validates the ongoing efforts to reduce anthropogenic mercury emissions,鈥 he says. 鈥淐ountries have shown this is something they鈥檙e willing to take on. These results allow us to have reasonable expectations about how long it will take for mercury levels to go down and stabilize.鈥</p> <p>Lehnherr also wants to reassure people in northern communities who may be concerned about the safety of their food supply.</p> <p>鈥淲henever I talk about the risks of mercury and negative health impacts, I always stress that the benefits of consuming traditional foods vastly outweigh the risks of contaminants. Locally caught Arctic char has better nutritional value than dried goods and flown-in goods,鈥 he says.</p> <p>Lehnherr plans to continue his study of methylmercury in the Arctic region to get a better sense of the long-term impacts of climate change.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Fri, 19 Feb 2021 18:31:22 +0000 Christopher.Sorensen 168427 at Ice arches holding Arctic's 鈥楲ast Ice Area鈥 in place are at risk, 茄子直播 researcher says /news/ice-arches-holding-arctic-s-last-ice-area-place-are-risk-u-t-researcher-says <span class="field field--name-title field--type-string field--label-hidden">Ice arches holding Arctic's 鈥楲ast Ice Area鈥 in place are at risk, 茄子直播 researcher says</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/Sea_ice_in_the_Nares_Strait.jpg?h=afdc3185&amp;itok=BFMTAGE_ 370w, /sites/default/files/styles/news_banner_740/public/Sea_ice_in_the_Nares_Strait.jpg?h=afdc3185&amp;itok=VeRgWrR3 740w, /sites/default/files/styles/news_banner_1110/public/Sea_ice_in_the_Nares_Strait.jpg?h=afdc3185&amp;itok=Y61Eupwn 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/Sea_ice_in_the_Nares_Strait.jpg?h=afdc3185&amp;itok=BFMTAGE_" alt="&quot;&quot;"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2021-01-05T09:21:49-05:00" title="Tuesday, January 5, 2021 - 09:21" class="datetime">Tue, 01/05/2021 - 09:21</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">Sea ice in the Nares Strait as seen from a NASA P-3B turboprop during a 2013 survey flight (photo by Christy Hansen/NASA)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/global-lens" hreflang="en">Global Lens</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/arctic" hreflang="en">Arctic</a></div> <div class="field__item"><a href="/news/tags/climate-change" hreflang="en">Climate Change</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> <div class="field__item"><a href="/news/tags/u-t-mississauga" hreflang="en">茄子直播 Mississauga</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Snugged up against the upper edges of the Canadian Arctic Archipelago and Greenland&nbsp;lies the oldest and thickest sea ice in the world, covering hundreds of thousands of square kilometres of ocean. Arctic sea ice grows and shrinks with the seasons, but this ice&nbsp;has so far lasted even through the warmest summers on record.</p> <p>Scientists call this region 鈥淭he Last Ice Area.鈥 They say it could endure even after the rest of the Arctic becomes ice-free in the warmer months, providing a vital refuge for polar bears, walruses and other species that rely on sea ice to survive.</p> <p>But recent research at the University of Toronto Mississauga suggests the Last Ice Area may be in more peril than previously thought. In&nbsp;a recent paper <a href="https://www.nature.com/articles/s41467-020-20314-w.epdf?sharing_token=Y6bcYsrCA7546bXy0vFJItRgN0jAjWel9jnR3ZoTv0P28JRaSF4MIz-FeIYeYqW2puvaunQhPHC1F06uK7hVCSMCy4gDwlpBfTjSoT_xRZ4oapDmrxhvq1ysTsb-5uBunXdx1Cblhus24jcXVK4-GUjUUt-M7HZ4sq4WEaV-Qfc%3D">published in the journal&nbsp;<em>Nature</em> <em>Communications</em>,</a>&nbsp;Professor <strong>Kent Moore </strong>and his co-authors describe how this multi-year ice is at risk not just of melting in place, but of floating southward into warmer regions. This, in turn, would create an 鈥渋ce deficit鈥 and hasten the disappearance of the Last Ice Area.</p> <p>鈥淭his very old ice is what we鈥檙e concerned about,鈥 says Moore, who is in 茄子直播 Mississauga鈥檚 department of chemical and physical sciences. 鈥淭he hope is that this area will persist into the middle part of this century or even longer.&nbsp;And then, hopefully,&nbsp;we'll&nbsp;eventually be able to cool the planet down. The ice will start growing again, and then this area can act as a sort of seed,鈥</p> <p><img class="migrated-asset" src="/sites/default/files/southern_ice_arch_2020.jpg" alt>Using satellite data, Moore has been studying ice arches&nbsp;that form along Nares Strait, a 40-kilometre-wide, 600-kilometre-long channel that runs between Greenland and Ellesmere Island from the Arctic Ocean into Baffin Bay.</p> <p>&nbsp;</p> <p>Moore had&nbsp;already observed warning trends in earlier research that indicated this ice is increasingly on the move.</p> <p>鈥淭he Last Ice Area is losing ice mass at twice the rate of the entire Arctic,鈥 Moore says. 鈥淲e realized this area may not be as stable as people think.鈥</p> <p>His most recent analysis of satellite data says the problem may be getting even worse. The arches along Nares Strait that historically have held the Last ice Area in place have become less stable, according the study.</p> <p>鈥淭he ice arches that usually develop at the northern and southern ends of Nares Strait play an important role in modulating the export of Arctic Ocean multi-year sea ice,鈥 he and his authors write.</p> <p>鈥淭he duration of arch formation has decreased over the past 20 years, while the mass of ice exported through Nares Strait has increased.鈥</p> <p>The ice arches form as the weather cools. Multiple ice floes converge as they funnel into the relatively narrow strait,&nbsp;forming&nbsp;huge structures that look like bridge supports turned on their sides. The arches span the full width of the passage, blocking the movement of multi-year ice from north to south.</p> <p>鈥淚t's really quite profound to imagine a 100-kilometre-long barrier of ice that remains stationary for months at a time. That's more than twice as long as Louisiana鈥檚 Lake Pontchartrain Causeway 鈥 the world鈥檚 longest continuous bridge over water,鈥 Moore says. 鈥淚t speaks to the strength of ice.鈥</p> <p>But that strength is diminishing. Ice arches only form for part of the year. When they break up in the spring, ice moves more freely down the Nares Strait. And that breakup is happening sooner than in the past.</p> <p>鈥淓very year, the reduction in duration is about one week,鈥 Moore says.&nbsp;鈥淭hey used to persist for about 200 days&nbsp;and now they鈥檙e persisting for about 150 days. There鈥檚 quite a remarkable reduction.</p> <p>鈥淲e think that it鈥檚 related to the fact the ice is just thinner and thinner ice is less stable.鈥</p> <p>The impact of losing the Last Ice Area would extend far beyond photogenic species like polar bears. Ice algae flourishes below the ice and in brine channels that run through its cracks and fissures, supplying carbon, oxygen&nbsp;and nutrients that underpin an elaborate but&nbsp;vulnerable&nbsp;ecosystem.</p> <p>In 2019, the Canadian government designated a section of the Last Ice Area&nbsp;as the Tuvaijuittuq Marine Protected Area.&nbsp;Tuvaijuittuq&nbsp;is Inuktut for 鈥渢he place where the&nbsp;ice&nbsp;never melts.鈥</p> <p>Moore remains hopeful that his analysis of the Nares Strait ice arches will focus more attention on this important region of the Arctic. However, he says action targeted specifically at preserving the arches won鈥檛 be sufficient to solve the problem. A global solution is needed.</p> <p>鈥淭he scale is so huge and the region is so remote,鈥 he says.&nbsp;鈥淭he only thing we can do is cool the planet down. Then the arches will hopefully naturally form again.鈥</p> <p><em>Inset: Images of the ice arch that formed at the southern end of Nares Strait in 2020. The upper image shows the arch holding back the ice while the lower image shows the ice streaming southwards after the arch collapses (Sentinel-2 satellite imagery courtesy of the European Space Agency)</em></p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Tue, 05 Jan 2021 14:21:49 +0000 Christopher.Sorensen 167982 at Gut feeling: 茄子直播 Mississauga research reveals how honeybees identify outsiders /news/gut-feeling-u-t-mississauga-research-reveals-how-honeybees-identify-outsiders <span class="field field--name-title field--type-string field--label-hidden">Gut feeling: 茄子直播 Mississauga research reveals how honeybees identify outsiders</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/Honeybee_damien-tupinier-unsplash.jpg?h=afdc3185&amp;itok=RqslA3i5 370w, /sites/default/files/styles/news_banner_740/public/Honeybee_damien-tupinier-unsplash.jpg?h=afdc3185&amp;itok=UvrvF4U_ 740w, /sites/default/files/styles/news_banner_1110/public/Honeybee_damien-tupinier-unsplash.jpg?h=afdc3185&amp;itok=feKo0oSg 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/Honeybee_damien-tupinier-unsplash.jpg?h=afdc3185&amp;itok=RqslA3i5" alt="Honeybees on a honeycomb"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2020-10-27T10:47:36-04:00" title="Tuesday, October 27, 2020 - 10:47" class="datetime">Tue, 10/27/2020 - 10:47</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">(photo by Damien Tupinier via Unsplash)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/biology" hreflang="en">Biology</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> <div class="field__item"><a href="/news/tags/u-t-mississauga" hreflang="en">茄子直播 Mississauga</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Honeybees identify strangers in their midst using signals from the bacteria in the intruder鈥檚 digestive system, an international team of biologists has found.</p> <p>The&nbsp;research, <a href="http://advances.sciencemag.org/content/6/42/eabd3431">published recently in <em>Science Advances</em></a>,&nbsp;contributes to broader questions about the tools social animals use to distinguish between insiders and outsiders in their community.</p> <p><em>鈥</em>This idea of how an individual knows another individual, how they recognize whether they're like themselves or not, is a mystery,鈥 says Professor&nbsp;<strong>Joel Levine</strong>, chair of biology at 茄子直播 Mississauga and&nbsp;one of the paper鈥檚 authors.</p> <p>Many animals distinguish members and non-members of their pack, herd or&nbsp;flock&nbsp;using visual cues, scents, behaviours, genetic relationships&nbsp;and other factors.</p> <p>Bee colonies, with their sophisticated, hierarchical structures, 鈥渁re the best show in town when it comes to sociality,鈥 Levine says.</p> <p>The social insects take on different roles, including tending the queen, caring for young, cleaning the hive, building honeycomb, collecting nectar and pollen&nbsp;and producing honey. Bees have no trouble recognizing the other members of their hive. But should invaders from another nest try to infiltrate, guard bees quickly identify the stranger and attack.</p> <p>The research team was interested in how that identification happens. Earlier research had eliminated differences in genetic code as the main mechanism.</p> <p>鈥淚t's a very common beekeeping technique to take newly emerged bees from a strong colony and dump them into a weak colony to make that weaker colony stronger,鈥 says Cassondra Vernier, a biologist at Washington University who developed the microbiome theory at the heart of their research. 鈥淭hose bees will actually grow up in this new colony that they're not genetically related to. And they will develop the cue that matches that colony. The bees of that colony will recognise them as nestmates.鈥</p> <p>Vernier theorized that bee-belly bacteria might hold answers. She hypothesized that, in the close proximity of hive life, bees would exchange bacteria, creating a common 鈥渕icrobiome鈥 across the colony.</p> <p>She shipped frozen bee remains from her laboratory in St. Louis, Mo. to Mississauga, Ont., where Levine and <strong>Joshua Krupp</strong>, a research associate,<strong>&nbsp;</strong>analyzed variations in the insects鈥 microbiomes. They confirmed that bees from each colony shared common gut bacteria, distinct from those from other hives. In addition, the distinct microbiome changed the type&nbsp;of pheromones the bees produced. Hive members exude a unique combination of chemicals, making a kind of signature that other bees can sense 鈥&nbsp;likely through a combination of taste, smell and texture.</p> <p>The researchers are cautious about assigning human-like abilities to bees鈥 perceptual capacities. In some ways, the us-and-them behaviour in the bee world has more in common with the way immune cells identify and attack invaders than the way thinking organisms treat outsiders. But there鈥檚 still much to learn about the boundaries between chemical and social reactions.</p> <p>鈥淲e鈥檙e&nbsp;a long way from making an argument that an individual bee is a self-conscious, sentient being,鈥 says Levine. 鈥淏ut we鈥檙e not so far from saying that these guys know something about each other, and that they're making decisions based on that knowledge when they interact. Does that have evolutionary implications that may affect how we understand other species all the way up to and including humans? I would say absolutely. But can we say yet how it's going to shake out? No way.鈥</p> <p>The research received support from the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Council, among others.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Tue, 27 Oct 2020 14:47:36 +0000 Christopher.Sorensen 166194 at Can we eliminate bias in AI? How Canada鈥檚 commitment to multiculturalism could help it become a world leader /news/can-we-eliminate-bias-ai-how-canada-s-commitment-multiculturalism-could-help-it-become-world <span class="field field--name-title field--type-string field--label-hidden">Can we eliminate bias in AI? How Canada鈥檚 commitment to multiculturalism could help it become a world leader</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2019-07-24-ai.jpg?h=afdc3185&amp;itok=RZsTFcuC 370w, /sites/default/files/styles/news_banner_740/public/2019-07-24-ai.jpg?h=afdc3185&amp;itok=6T_LCvNf 740w, /sites/default/files/styles/news_banner_1110/public/2019-07-24-ai.jpg?h=afdc3185&amp;itok=yXuosdnX 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2019-07-24-ai.jpg?h=afdc3185&amp;itok=RZsTFcuC" alt="Illustration "> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>noreen.rasbach</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2019-07-24T11:03:25-04:00" title="Wednesday, July 24, 2019 - 11:03" class="datetime">Wed, 07/24/2019 - 11:03</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">(illustration by S茅bastien Thibault)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/global-lens" hreflang="en">Global Lens</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/artificial-intelligence" hreflang="en">Artificial Intelligence</a></div> <div class="field__item"><a href="/news/tags/computer-science" hreflang="en">Computer Science</a></div> <div class="field__item"><a href="/news/tags/diversity" hreflang="en">Diversity</a></div> <div class="field__item"><a href="/news/tags/faculty-arts-science" hreflang="en">Faculty of Arts &amp; Science</a></div> <div class="field__item"><a href="/news/tags/faculty-medicine" hreflang="en">Faculty of Medicine</a></div> <div class="field__item"><a href="/news/tags/global" hreflang="en">Global</a></div> <div class="field__item"><a href="/news/tags/research-innovation" hreflang="en">Research &amp; Innovation</a></div> <div class="field__item"><a href="/news/tags/vector-institute" hreflang="en">Vector Institute</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item"> </div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><div>In human beings, intelligence is no inoculation against bias and bigotry. The same holds true for computers. Intelligent machines learn about the world through the filters of human language and historical behaviour 鈥 meaning they can just as easily absorb humanity鈥檚 worst values as they can its best.</div> <div>&nbsp;</div> <div>Researchers who aim to develop ever-smarter machines have their work cut out for them to ensure that they鈥檙e not inadvertently imbuing computers with misogyny, racism or other forms of bigotry.</div> <div>&nbsp;</div> <div>鈥淚t鈥檚 a huge risk,鈥 says <strong>Marzyeh Ghassemi</strong>, an assistant professor in the University of Toronto's&nbsp;department of computer science and Faculty of Medicine who focuses on health-care applications for artificial intelligence (AI). 鈥淟ike all advances that leapfrog societies forward, there are large risks that we must decide to accept or not to accept.鈥</div> <div>&nbsp;</div> <div>Bias can creep into algorithms in many ways. In a highly influential branch of AI known as 鈥渘atural language processing,鈥 problems can arise from the 鈥渢ext corpus鈥 鈥 the source material the algorithm uses to learn about the relationships between different words.</div> <div>&nbsp;</div> <div>Natural language processing, or 鈥淣LP,鈥 allows a computer to understand human-style speech 鈥 informal, conversational and contextual. NLP algorithms comb through billions of words of training text 鈥 the corpus might be, say, the entirety of Wikipedia. One algorithm works by assigning to each word a set of numbers that reflects different aspects of its meaning 鈥 鈥渒ing鈥 and 鈥渜ueen鈥 for instance, would have similar scores relating to the idea of royalty, but opposite scores relating to gender. NLP is a powerful system that allows machines to learn about relationships between words 鈥 in some cases, without direct human involvement.</div> <div>&nbsp;</div> <div>鈥淓ven though we鈥檙e not always teaching them specifically, what they learn is incredible,鈥 says <strong>Kawin Ethayarajh</strong>, a researcher who focuses partly on fairness and justice in AI applications. 鈥淏ut it鈥檚 also a problem. In the corpus, the relationship between 鈥榢ing鈥 and 鈥榪ueen鈥 might be similar to the relationship between 鈥榙octor鈥 and 鈥榥urse.鈥欌</div> <div>&nbsp;</div> <div>But of course, all kings are men; not all doctors are men. And not all nurses are women.</div> <div>&nbsp;</div> <div>When an algorithm absorbs the sexist tropes of historical human attitudes, it can lead to real-life consequences, as happened in 2014 when Amazon developed an algorithm to vet job applicants鈥 resum茅s. The company trained its machines using 10 years of hiring decisions. But in 2015, they acknowledged that, in tests, the system was giving unearned preference to resum茅s from male applicants. They tweaked the system to force it to ignore gender information, but ultimately shut down the project before actually putting it to use as they could not be sure their algorithm wasn鈥檛 perpetrating other forms of discrimination.</div> <div>&nbsp;</div> <div>Mitigating sexist source material can involve technological and methodological adjustments. 鈥淚f we can understand exactly what underlying assumptions the corpus has that cause these biases to be learned, we can either select corpora without those biases or correct it during the training process,鈥 says Ethayarajh.</div> <div>&nbsp;</div> <div>It鈥檚 common practice for researchers to design an algorithm that corrects prejudicial assumptions automatically. By adjusting the weight of the numbers it assigns to each word, the computer can avoid making sexist or racist associations.</div> <div>&nbsp;</div> <div>But what exactly are the assumptions that need correcting? What does a fair-minded AI really look like? Debates over privilege, bigotry, diversity and systemic bias are far from settled. Should a hiring algorithm have a stance on affirmative action? Should a self-driving car take special care if another vehicle has a 鈥淏aby on Board鈥 sticker? How should an AI-driven analysis of legal documents factor in the historical treatment of Indigenous Peoples? Contentious societal issues don鈥檛 disappear merely because machines take over certain recommendations or decisions.</div> <div>&nbsp;</div> <div>Many people view Canada鈥檚 flawed but relatively successful model of multiculturalism as a chance to lead in fair AI research.</div> <div>&nbsp;</div> <div>鈥淐anada certainly does have an opportunity,鈥 says <strong>Ronald Baecker</strong>, a professor emeritus of computer science and the author of <em>Computers and Society: Modern Perspectives</em>. He sees a role for government to redress the societal inequities, injustices and biases associated with AI by, for example, setting up protections for employees who choose to speak out against biased or unfair AI-driven products. 鈥淭here鈥檚 a need for more thinking and legislation with respect to the concept of what I would call 鈥榗onscientious objection鈥 by high-tech employees.鈥</div> <div>&nbsp;</div> <div>He also believes that the computer scientists developing smart technologies should be required to study the societal impact of such work. 鈥淚t鈥檚 important that professionals who work in AI recognize their responsibility,鈥 he says. 鈥淲e鈥檙e dealing with life-and-death situations in increasingly important activities where AI is being used.鈥</div> <div>&nbsp;</div> <div>Algorithms that help judges set bail and sentence criminals can absorb long-standing biases in the legal system, such as treating racialized people as if they are more likely to commit additional crimes. The algorithms might flag people from certain communities as posing too high a risk to receive a bank loan. They also might be better at diagnosing skin cancer in white people than in people with darker skin, as a result of having been trained on skewed source material.</div> <div>&nbsp;</div> <div>The stakes are incredibly high in health care, where inequitable algorithms could push people who have been poorly served in the past even further into the margins.</div> <div>&nbsp;</div> <div>In her work at 茄子直播 and at the Vector Institute for Artificial Intelligence, Ghassemi, like other researchers, takes pains to identify potential bias and inequity in her algorithms. She compares the recommendations and predictions of her diagnostic tools against real-world outcomes, measuring their accuracy for different genders, races, ages and socio-economic factors.</div> <div>&nbsp;</div> <div><img class="migrated-asset" src="/sites/default/files/2018-06-29-Marzyeh_Ghassemi-resized_0.jpg" alt></div> <div><em>鈥淟ike all advances that leapfrog societies forward, there are large risks that we must decide to accept or not to accept,鈥&nbsp;says&nbsp;<strong>Marzyeh Ghassemi</strong>, an assistant professor in the&nbsp;department of computer science who focuses on health-care applications for artificial intelligence&nbsp;&nbsp;</em></div> <div>&nbsp;</div> <div>In theory, Canada offers a head start for researchers interested in health-care applications that reflect values of fairness, diversity and inclusion. Our universal health-care system creates a repository of electronic health records that provides a wealth of medical data that could be used to train AI-driven applications. This potential drew Ghassemi to Toronto. But the technology, information, formatting and rules to access these records vary from province to province, making it complicated to create the kind of data sets that can move research forward.</div> <div>&nbsp;</div> <div>Ghassemi was also surprised to learn that these records only rarely include data about race. This means if she鈥檚 using an algorithm to determine how well a given treatment serves different sectors of society, she could identify disparities between men and women, for example, but not between white people and racialized people. As a result, in her teaching and research, she鈥檚 using publicly available American data that contains information about race.</div> <div>&nbsp;</div> <div>鈥淎uditing my own models [using American data], I can show when something has higher inaccuracy for people with different ethnicities,鈥 she says. 鈥淚 can鈥檛 make this assessment in Canada. There鈥檚 no way for me to check.鈥</div> <div>&nbsp;</div> <div>Ghassemi is interested in creating AI applications that are fair in their own right 鈥 and that also can help human beings counteract their own biases. 鈥淚f we can provide tools based on large diverse populations, we鈥檙e giving doctors something that will help them make better choices,鈥 she says.</div> <div>&nbsp;</div> <div>Women, for example, are significantly underdiagnosed for heart conditions. An AI could flag such a danger for a doctor who might overlook it. 鈥淭hat鈥檚 a place where a technological solution can help, because doctors are humans, and humans are biased,鈥 she says.</div> <div>&nbsp;</div> <div>Ethayarajh concurs with Ghassemi and Baecker that Canada has an important opportunity to press its advantage on fairness and bias in artificial intelligence research.</div> <div>&nbsp;</div> <div>鈥淚 think AI researchers here are very aware of the problem,鈥 Ethayarajh says. 鈥淚 think a part of that is, if you look around the office, you see a lot of different faces. The people working on these models will be end-users of these models. More broadly, I think there is a very strong cultural focus on fairness that makes this an important area for researchers in this country.鈥</div> <div>&nbsp;</div> <div><em>This story originally appeared in <a href="https://magazine.utoronto.ca/">University of Toronto Magazine</a>.&nbsp;</em></div> <div>&nbsp;</div> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Wed, 24 Jul 2019 15:03:25 +0000 noreen.rasbach 157345 at 茄子直播 physicists discovered a way to increase the resolution of microscopes and telescopes /news/u-t-physicists-discovered-way-increase-resolution-microscopes-and-telescopes <span class="field field--name-title field--type-string field--label-hidden">茄子直播 physicists discovered a way to increase the resolution of microscopes and telescopes</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2017-02-16-telescope.jpg?h=afdc3185&amp;itok=clXKxop8 370w, /sites/default/files/styles/news_banner_740/public/2017-02-16-telescope.jpg?h=afdc3185&amp;itok=s12qmp-K 740w, /sites/default/files/styles/news_banner_1110/public/2017-02-16-telescope.jpg?h=afdc3185&amp;itok=_JRe2ANc 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2017-02-16-telescope.jpg?h=afdc3185&amp;itok=clXKxop8" alt="Photo of Edwin Tham and Hugo Ferretti"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>ullahnor</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2017-02-16T14:40:35-05:00" title="Thursday, February 16, 2017 - 14:40" class="datetime">Thu, 02/16/2017 - 14:40</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">茄子直播 PhD students Edwin (Weng Kian) Tham and Hugo Ferretti are part of the team that helped develop a way to look at other properties of light (photo by Diana Tyszko)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Patchen Barss</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/microscope" hreflang="en">Microscope</a></div> <div class="field__item"><a href="/news/tags/telescope" hreflang="en">Telescope</a></div> <div class="field__item"><a href="/news/tags/physics" hreflang="en">Physics</a></div> <div class="field__item"><a href="/news/tags/faculty-arts-science" hreflang="en">Faculty of Arts &amp; Science</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>University of Toronto researchers have found a way to increase the resolution of microscopes and telescopes beyond long-accepted limitations by tapping into previously neglected properties of light.</p> <p>The method allows observers to distinguish very small or distant objects that are so close together they normally meld into a single blur.</p> <p>The&nbsp;research appears&nbsp;in the journal&nbsp;<em><a href="http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.070801">Physical Review Letters</a></em>.</p> <p>Because of the&nbsp;laws of physics, which&nbsp;cause light to spread out or 鈥渄iffract,鈥 telescopes and microscopes are great for observing lone subjects. With an object like a binary star&nbsp;on the other hand, two stars that are close together may appear at a distance as one&nbsp;blurry dot, and their individual information is irrevocably lost.</p> <p>Part of the problem is circumventing the limitations of what is referred to as the&nbsp;鈥淩ayleigh Criterion.鈥</p> <p>More than 100 years ago, British physicist John William Strutt 鈥 better known as Lord Rayleigh 鈥 established the minimum distance between objects necessary for a telescope to pick out each individually. The 鈥淩ayleigh Criterion鈥 has stood as an inherent limitation of the field of optics ever since.</p> <p>Telescopes, though, only register light鈥檚 鈥渋ntensity鈥 or brightness. Light has other properties that now appear to allow one to circumvent the Rayleigh Criterion.</p> <p>鈥淭o beat Rayleigh鈥檚 curse, you have to do something clever,鈥 says Professor <strong>Aephraim Steinberg</strong>, a physicist at 茄子直播鈥檚 Centre for Quantum Information and Quantum Control&nbsp;and senior fellow in the quantum information science program at the Canadian Institute for Advanced Research.&nbsp;</p> <p>鈥淲e measured another property of light called 鈥榩hase.鈥 And phase gives you just as much information about sources that are very close together as it does those with large separations.鈥</p> <p>Light travels in waves, and all waves have a phase. Phase refers to the location of a wave鈥檚 crests and troughs. Even when a pair of close-together light sources blurs into a single blob, information about their individual wave phases remains intact. You just have to know how to look for it.</p> <p>This realization was published by National University of Singapore researchers Mankei Tsang, Ranjith Nair, and Xiao-Ming Lu last year in <em>Physical Review X. </em>Researchers like Steinberg&nbsp;and his team immediately set about devising a variety of ways to put it into practice.</p> <p>鈥淲e tried to come up with the simplest thing you could possibly do,鈥 Steinberg says. 鈥淭o play with the phase, you have to slow a wave down, and light is actually easy to slow down.鈥</p> <p>His team, including PhD students <strong>Edwin (Weng Kian) Tham</strong> and <strong>Hugo Ferretti</strong>, split test images in half. Light from each half passed&nbsp;through glass of a different thickness, which slowed&nbsp;the waves for different amounts of time, changing their respective phases. When the beams recombined, they created distinct interference patterns that told&nbsp;researchers whether the original image contained one object or two 鈥 at resolutions well beyond the Rayleigh Criterion.</p> <p>So far, Steinberg鈥檚 team has tested the method only in artificial situations involving highly restrictive parameters.</p> <p>鈥淚 want to be cautious 鈥 these are early stages,鈥 Steinberg says. 鈥淚n our laboratory experiments, we knew we just had one spot or two, and we could assume they had the same intensity. That鈥檚 not necessarily the case in the real world. But people are already taking these ideas and looking at what happens when you relax those assumptions.鈥</p> <p>The advance has potential applications both in observing the cosmos, and also in microscopy, where the method can be used to study bonded molecules and other tiny, tight-packed structures.</p> <p>Regardless of how much phase measurements ultimately improve imaging resolution, Steinberg says the experiment鈥檚 true value is in shaking up physicists鈥 concept of 鈥渨here information actually is.鈥</p> <p>Steinberg鈥檚 鈥渄ay job鈥 is in quantum physics 鈥 this experiment was a departure for him. He says work in the quantum realm provided key philosophical insights about information itself that helped him beat 鈥淩ayleigh鈥檚 curse.鈥</p> <p>鈥淲hen we measure quantum states, you have something called the Uncertainty Principle, which says you can look at position or velocity, but not both,鈥 he says. 鈥淵ou have to choose what you measure. Now we鈥檙e learning that imaging is more like quantum mechanics than we realized. When you only measure intensity, you鈥檝e made a choice, and you鈥檝e thrown out information. What you learn depends on where you look.鈥</p> <p>Support for the research was provided by by the Natural Sciences and Engineering Research Council of Canada, the Canadian Institute for Advanced Research, and Northrop-Grumman Aerospace Systems NG Next.</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 16 Feb 2017 19:40:35 +0000 ullahnor 104983 at Team led by 茄子直播 researchers discovers energy source sustaining microbial life deep beneath Earth鈥檚 surface /news/team-led-u-t-researchers-discovers-energy-source-sustaining-microbial-life-deep-beneath-earth-s <span class="field field--name-title field--type-string field--label-hidden">Team led by 茄子直播 researchers discovers energy source sustaining microbial life deep beneath Earth鈥檚 surface</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/2016-10-27-rock-microbial-lead.jpg?h=afdc3185&amp;itok=LVYBNBQJ 370w, /sites/default/files/styles/news_banner_740/public/2016-10-27-rock-microbial-lead.jpg?h=afdc3185&amp;itok=5mzqCSd1 740w, /sites/default/files/styles/news_banner_1110/public/2016-10-27-rock-microbial-lead.jpg?h=afdc3185&amp;itok=ZcJG09Zw 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/2016-10-27-rock-microbial-lead.jpg?h=afdc3185&amp;itok=LVYBNBQJ" alt="Photo of rock containing sulfur"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>ullahnor</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2016-10-27T11:49:09-04:00" title="Thursday, October 27, 2016 - 11:49" class="datetime">Thu, 10/27/2016 - 11:49</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">Sulfide minerals in the host rock, including pyrite, are oxidized by products of radiolysis to produce the source of sulfate found in the fracture waters (photos by K. Gorra)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Patchen Barss</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/global-lens" hreflang="en">Global Lens</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/faculty-arts-science" hreflang="en">Faculty of Arts &amp; Science</a></div> <div class="field__item"><a href="/news/tags/earth-sciences" hreflang="en">Earth Sciences</a></div> <div class="field__item"><a href="/news/tags/barbara-sherwood-lollar" hreflang="en">Barbara Sherwood Lollar</a></div> <div class="field__item"><a href="/news/tags/research" hreflang="en">Research</a></div> <div class="field__item"><a href="/news/tags/collaboration" hreflang="en">Collaboration</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>In Northern Ontario, a team led by 茄子直播 researchers has&nbsp;found the 鈥済eochemical fingerprints&nbsp;of life鈥 and the energy sustaining this&nbsp;life&nbsp;in waters more than two kilometres below the surface of the Earth. The discovery demonstrates how life can be sustained even in the seemingly inhospitable environments of the deep Earth crust. &nbsp;</p> <p>Most life on Earth gets its energy 鈥 directly or indirectly 鈥 from the sun. But there are other options.</p> <p>鈥淢icrobial subsurface communities are often chemosynthetic, not photosynthetic,鈥 says <a href="http://www.provost.utoronto.ca/awards/uprofessors.htm">University Professor</a> <strong>Barbara Sherwood Lollar</strong> in the department of earth sciences at the Faculty of Arts &amp; Science. &nbsp;鈥淚n chemosynthesis, a molecule like hydrogen 鈥榙onates鈥 electrons, and sulfate 鈥榓ccepts鈥 them. Basically, all metabolism works through this kind of exchange of electrons. That鈥檚 how energy works. That鈥檚 how life works.鈥&nbsp;</p> <p>The chemical reactions producing the electron donor in these deep waters had been identified several years ago, but the source of sulfate 鈥&nbsp;the electron acceptor 鈥&nbsp;had been elusive.</p> <p><img alt class="media-image attr__typeof__foaf:Image img__fid__2340 img__view_mode__media_original attr__format__media_original" height="500" src="/sites/default/files/2016-10-27-microbial-embed.jpg" typeof="foaf:Image" width="750" loading="lazy"><br> <em>Co-authors Barbara Sherwood Lollar and <strong>Georges Lacrampe-Couloume</strong>, holding pyrite rich rocks from the field site ( photo by&nbsp;K. Gorra)</em></p> <p>In a paper published this week in <a href="http://www.nature.com/articles/ncomms13252"><em>Nature Communications</em></a>, Sherwood Lollar and her colleagues report that sulfate dissolved in these waters 2.4 km below the surface comes from oxidation of the sulfide minerals in the ancient rocks via chemicals produced when radiation breaks the water down into its constituent parts.</p> <p>First author <strong>Long Li</strong>, now the Canada Research Chair in stable isotope geochemistry at the University of Alberta, worked with Sherwood Lollar at 茄子直播 as a postdoctoral fellow. Along with researchers from McGill University, they studied the distribution pattern of multiple sulfur isotopes 鈥 that is, sulfur atoms that differ by the number of neutrons 鈥 in the dissolved sulfate in ancient subterranean waters near Timmins, Ont.</p> <h3><a href="https://deepcarbon.net/feature/active-sulfur-recycling-billion-year-old-water-canadian-shield-rocks#.WBIvFk1TGUl">Read about the latest findings in&nbsp;<em>Deep Carbon Observatory</em></a></h3> <p>Their earlier work had revealed that these waters contain&nbsp;hydrogen and sulfate 鈥 key components that make life possible without sunlight. The multiple sulfur isotope compositions in the sulfate show a unique pattern, only seen in rocks formed before oxygen appeared in Earth鈥檚 atmosphere about 2.4 billion years ago.</p> <p>By matching this isotopic feature in the dissolved sulfate with that of pyrite in the 2.7-billion-year-old rocks hosting the waters, the researchers demonstrated that the same pyrite and other sulfide ores that make these rocks ideal for economic mining of metals, produce the 鈥渇uel鈥 for microbial metabolisms.</p> <p>But there were other surprises in store.</p> <p>鈥淲hen we looked at the sulfate dissolved in these waters, we found it was more enriched in an isotope called sulphur 34 than expected,鈥 Sherwood Lollar says.</p> <h3><a href="/news/ancient-hydrogen-rich-waters-discovered-deep-underground-locations-around-world">Read more about Barbara Sherwood Lollar's research</a></h3> <p>Living creatures and non-organic chemical reactions both affect these isotopic patterns, often in distinctive ways.</p> <p>鈥淧eople often think we study ancient life through fossils,鈥 says Sherwood Lollar. 鈥淏ut the evidence that life arose on our planet 3.8 to 4 billion years ago comes not from fossils, which came much later in Earth鈥檚 history, but from geochemical fingerprints.鈥</p> <p>Microbes leave behind geochemical isotopic signatures that allow researchers to detect their existence, even in the absence of fossil or biological data.</p> <p>The authors tested models of both chemical and biological processes to try to explain the enrichments in sulphur 34. The results pointed to a biological process&nbsp;and suggested that microbial communities must have colonized these rocks long ago.</p> <p>鈥淲e looked carefully at chemical processes that might account for this pattern, but they just didn鈥檛 fit. That forces us to look at the other kind of process 鈥 a biological one, which fits&nbsp;very well,鈥 Sherwood Lollar&nbsp;says. 鈥淭here must have been microbes in these waters on a geologically long timescale.鈥</p> <h3><a href="/news/two-u-t-s-university-professors-honoured-royal-society-exceptional-contributions">Read about Barbara Sherwood Lollar being honoured by the Royal Society of Canada</a></h3> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Thu, 27 Oct 2016 15:49:09 +0000 ullahnor 101569 at Making waves: How the University of Toronto made the discovery of gravitational waves possible /news/making-waves-how-uoft-made-discovery-gravitational-waves-possible <span class="field field--name-title field--type-string field--label-hidden">Making waves: How the University of Toronto made the discovery of gravitational waves possible</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/ligo%20team_3673.jpg?h=afdc3185&amp;itok=g1QV96R7 370w, /sites/default/files/styles/news_banner_740/public/ligo%20team_3673.jpg?h=afdc3185&amp;itok=ctehivG3 740w, /sites/default/files/styles/news_banner_1110/public/ligo%20team_3673.jpg?h=afdc3185&amp;itok=vjohx4nY 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/ligo%20team_3673.jpg?h=afdc3185&amp;itok=g1QV96R7" alt="Members of the LIGO team"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>lavende4</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2016-10-04T14:45:28-04:00" title="Tuesday, October 4, 2016 - 14:45" class="datetime">Tue, 10/04/2016 - 14:45</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">Left to right: PhD candidate Heather Fong, CITA professor Harald Pfeiffer and CITA post doctoral fellow Prayush Kumar (Photo by Diana Tyszko)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Patchen Barss</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/global-lens" hreflang="en">Global Lens</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/ligo" hreflang="en">LIGO</a></div> <div class="field__item"><a href="/news/tags/gravitational-waves" hreflang="en">Gravitational waves</a></div> <div class="field__item"><a href="/news/tags/faculty-arts-science" hreflang="en">Faculty of Arts &amp; Science</a></div> <div class="field__item"><a href="/news/tags/canadian-institute-theoretical-astrophysics" hreflang="en">Canadian Institute for Theoretical Astrophysics</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p><em>The discovery of gravitational waves in 2016 鈥 predicted by Albert Einstein 鈥 was one of the biggest sciences stories of the decade.</em>&nbsp; <em>While the discovery didn鈥檛 take the Nobel Prize today, many in the scientific community think it is just a matter of time before the Nobel committee honours the </em><em>Laser Interferometer Gravitational-Wave Observatory</em><em>&nbsp;(LIGO) team for one of the most outstanding contributions in the field of physics. Science writer Patchen Barss explains the discovery and the key contributions of University of Toronto鈥檚 <strong>Harald Pfeiffer</strong> and his team.</em></p> <div> <p>A billion years ago and a billion light years away, a star 36 times more massive than our Sun expended its remaining fuel in a final blast of nuclear fusion. With nothing left to burn, the star began to collapse under its own gravity. The atoms in its massive core collapsed like crushed soda cans. Protons and electrons ground together to form new neutrons.</p> </div> <p>The star鈥檚 density kept increasing. Its gravity became so concentrated and intense that not even light could escape any longer. Spacetime warped and ruptured. The star became a black hole.</p> <p>But that wasn鈥檛 the end of the story.</p> <p>A second black hole, the product of an only slightly smaller stellar cataclysm passed by. The two became trapped in each other鈥檚 mighty gravitational fields. They circled one another, slowly at first, but then more and more quickly. Their collision course became a high-speed death spiral that sent waves of gravitational energy rippling out across their galaxy and into the cosmos at the speed of light, stretching and squeezing space itself.</p> <p>Back on present-day Earth, came a different kind of merger: a collision of ideas between observational cosmologists and numerical relativity experts.</p> <p>In the 1970s, observational scientists had begun working on 鈥渓aser interferometry鈥 instruments that might detect gravitational waves. Decades of effort culminated in the construction of the Laser Interferometer Gravitational-Wave Observatory&nbsp;(LIGO), which comprises two massive detectors, one in Washington and the other in Louisiana.</p> <p>Concurrently, the University of Toronto was leading an international effort to simulate black hole collisions and predict what the emerging gravitational wave patterns might look like.</p> <p>The simulations belong to a field of study with the unglamorous name of 鈥渘umerical relativity.鈥 These supercomputer simulations nab few headlines, but without them, gravitational-wave research wouldn鈥檛 have gone far, even with LIGO鈥檚 whiz-bang technology. Scientists at 茄子直播 identified the need for powerful simulations early in LIGO鈥檚 planning stages, and drove the push to mature the theoretical science in time to make the most of LIGO鈥檚 observations.</p> <p>鈥淭he development of these simulations was precisely designed to make us able to analyze the data collected by LIGO experiments,鈥 says <strong>J. Richard Bond</strong>, a University Professor at the Canadian Institute for Theoretical Astrophysics (CITA) in the Faculty of Arts &amp; Science. Bond drove the effort to recruit an expert devoted to numerical relativity.</p> <p>鈥淒etecting gravitational waves is a huge revolution. It will be front and centre in what鈥檚 going to happen over the next few decades,鈥 he says. 鈥淵ou鈥檙e either on that bus or off it. Somebody here at the University had to be on the gravitational-wave bus.鈥</p> <p>In fact, 茄子直播 attracted a whole busload of graduate students and postdoctoral fellows to work on numerical relativity. From the start, though, the person driving that bus has been <strong>Harald Pfeiffer</strong>.</p> <p>Before Pfeiffer became an associate professor at CITA, he had already established his reputation in numerical relativity at Cornell University and Caltech.</p> <p>鈥淚 have always been interested in black holes and Einstein and gravity and computers,鈥 he says. 鈥淎t Cornell, I worked with one of the world鈥檚 experts on solving Einstein鈥檚 equations on supercomputers. The relevance to LIGO was there all along.鈥</p> <p>In the early 20<sup>th</sup> century, Albert Einstein proposed his Theory of Relativity a model of gravity and the universe that scientists have been testing and exploring ever since. Many non-scientists can recite Einstein鈥檚 most famous equation: E=mc<sup>2</sup>. But the so-called mass-energy equivalence equation is just one tiny part of the math behind relativity. Researchers are still finding new predictions based on Einstein鈥檚 equations, and using them to understand and simulate cosmic events that would otherwise defy imagination and intuition.</p> <p>鈥淭he first time people tried to simulate black-hole collisions on computers was in 1964,鈥 says Pfeiffer. 鈥淏ut even when I started my PhD, nobody had yet figured out how to do it. We made steady progress but only on arcane technical sub-problems. The big problem eluded everybody until 2005 when finally all the pieces came together.鈥</p> <p>LIGO faced hurdles of its own. Through the 1980s and 1990s, the project faced technological and budgetary delays. Between 2002 and 2010, the first major version of LIGO worked exactly as planned.&nbsp; But, during that time the cosmos failed to cooperate, sending no detectable waves our way. An international team of scientists continued to make refinements and improvements to increase LIGO鈥檚 sensitivity.</p> <p>LIGO鈥檚 L-shaped detectors work by splitting a laser beam into two waves radiating at right angles to one another. Each beam travels precisely the same distance 鈥 four kilometres 鈥 through a vacuum, bounces off a fine-tuned mirror and returns along the same path to the split point. In the absence of gravitational waves, the returning beams cancel each other out. The detector stays quiet.</p> <p>But passing gravitational waves would lengthen space in one direction and squeeze it in the other. Each beam would travel a slightly different distance, get out of sync with the other, and create a distinct, detectable interference pattern.</p> <p>Researchers built two such detectors thousands of kilometres apart, which allowed them not just to detect waves, but also to triangulate them to determine the location of their source.</p> <p>They still needed to know what to look for, though.</p> <p>鈥淚n the first 10 years, my research and LIGO were not directly touching each other,鈥 says Pfeiffer. 鈥淗owever, on both sides of the fence there was momentum building and building rapidly.鈥</p> <p>Both sides were working toward a goal that nobody was sure would be achievable. Still, they were spiraling in on one another, circling toward an explosive discovery.</p> <p>In September 2015 a new, vastly more sensitive iteration of LIGO came online. By then, Pfeiffer and his team had simulated thousands of collisions, creating a bank of 鈥減attern templates鈥 that gave observers clues about what to look for, and how to interpret what they found.</p> <p>Not long after, gravitational waves from that distant, ancient black-hole collision finally reached the Earth.</p> <p>Space compressed in one direction, stretched in another. The laser beams fell out of sync.</p> <p>鈥淐hirp!鈥</p> <p>That chirp, revealed to the world at an international press conference in February 2016, was an audio interpretation of a laser interference pattern created by billion-year-old gravitational waves.</p> <p>Using Pfeiffer鈥檚 simulations, researchers conclusively identified the pattern as the first-ever direct detection of gravitational waves.&nbsp;</p> <p>鈥溓炎又辈モ檚 key contribution was this waveform modeling,鈥 says Pfeiffer. 鈥淚f you know the shape of the signal you鈥檙e looking for, it鈥檚 like knowing the colour of a needle in a haystack. It鈥檚 easier to find.鈥</p> <p>In June 2016, LIGO scientists announced that the detectors had chirped again: a second detection. In this case, though, the black holes involved had about one third the combined mass of the first collision. It was a 鈥渜uieter鈥 crash with a weaker signal, which meant the simulations played an even more important role in its interpretation.</p> <p>鈥淭he second detection would have been an extremely marginal discovery without the simulations,鈥 says Pfeiffer. 鈥淚t would have been flagged as an interesting detection, possibly between two black holes, but nothing more precise.鈥</p> <p>The pattern templates also save time 鈥 rather than deciphering data for days on end, observers can say right away, 鈥淵ou鈥檝e got waves!鈥</p> <p>鈥淩eal-time is important, because there鈥檚 a whole band of astronomers across the world who are not part of LIGO,鈥 says <strong>Peter Martin</strong>, a CITA professor. 鈥淭hey want to turn optical or radio telescopes to the point of detection quickly to see whether any electromagnetic flash comes with gravitational radiation.鈥</p> <p>Researchers continue to improve LIGO, with plans to double its sensitivity. That puts pressure on Pfeiffer to keep building simulations based on Einstein鈥檚 relativity equations.</p> <p>鈥淎s boring as it sounds, there鈥檚 still a lot of work to be done in improving the waveforms that LIGO is looking for,鈥 says Pfeiffer. 鈥淚t鈥檚 really cool having this big breakthrough, but 99 percent of science is the tedious day-to-day work.鈥</p> <p>LIGO plans to continue observations in 2016, and it will join forces with a French-Italian gravitational-wave detector in 2017.&nbsp; Plans include studying more colliding black holes, scoping out their properties in unprecedented detail, and checking whether Einstein鈥檚 theory continues to work flawlessly in light of ever more precise data.</p> <p>Astronomers will also search for gravitational waves from sources other than black holes, including from less-massive-but-still-whoppingly-massive bodies like pulsars and other neutron stars that spin at high speed.</p> <p>Bond, though, has his eye on another target.</p> <p>鈥淚n Toronto, I and many others are heavily invested in discovering gravitational waves formed during the first moments of the universe,鈥 Bond says.</p> <p>鈥淭he sheer challenge of figuring out how to solve Einstein鈥檚 equations would have been enticing enough of a problem,鈥 Pfeiffer says. But he found it doubly exciting when those equations allowed scientists to precisely reconstruct the story of that distant, cataclysmic collision from a billion years earlier.</p> <p>鈥淚t is amazingly satisfying, to see the effort of thousands of people come together,鈥 he says.&nbsp; 鈥淏uilding the LIGO instruments, developing the software to analyse the data, and also our own contribution toward detecting and deciphering the signals. It was only through this huge joint effort that we could discover black holes colliding.鈥</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Tue, 04 Oct 2016 18:45:28 +0000 lavende4 101334 at Didn't see that stop sign? 茄子直播 researchers examine the invisible world of human perception /news/didnt-see-stop-sign-u-t-researchers-examine-invisible-world-human-perception <span class="field field--name-title field--type-string field--label-hidden">Didn't see that stop sign? 茄子直播 researchers examine the invisible world of human perception</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>sgupta</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2016-03-21T02:50:07-04:00" title="Monday, March 21, 2016 - 02:50" class="datetime">Mon, 03/21/2016 - 02:50</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"> graduate student Jason Rajsic, postdoctoral fellow Eric Taylor and Professor Jay Pratt of psychology (photo by Diana Tyszko)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Patchen Barss</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/features" hreflang="en">Features</a></div> <div class="field__item"><a href="/news/tags/faculty-arts-science" hreflang="en">Faculty of Arts &amp; Science</a></div> <div class="field__item"><a href="/news/tags/research" hreflang="en">Research</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Stage magicians are not the only ones who can distract the eye: a new cognitive psychology experiment from the University of Toronto demonstrates how all human beings have a built-in ability to stop paying attention to objects that are right in front of them.</p> <h3>We see much less of the world than we think we do</h3> <p>Perception experts have long known that we see much less of the world than we think we do. A person creates a mental model of their surroundings by stitching together scraps of visual information gleaned while shifting attention from place to place. Counterintuitively, the very process that creates the illusion of a complete picture relies on filtering out most of what鈥檚 out there.</p> <p>In a paper published&nbsp;in the journal <em><a href="http://www.springer.com/psychology/cognitive+psychology/journal/13414">Attention, Perception, &amp; Psychophysics</a></em> a team of 茄子直播 researchers reveal how people have more 鈥渢op-down鈥 control of what they don鈥檛 notice than many scientists previously believed.</p> <p>鈥淭he visual system really cares about objects,鈥 says postdoctoral fellow <strong>J. Eric T. Taylor</strong>, who is the lead author on the paper. 鈥淚f I move around a room, the locations of all the objects 鈥 chairs, tables, doors, walls, etc. 鈥 change on my retina, but my mental representation of the room stays the same.鈥</p> <h3>Objects play fundamental role in how we focus our attention</h3> <p>Objects play such a fundamental role in how we focus our attention that many perception researchers believe we are 鈥渁ddicted鈥 to them; we couldn鈥檛 stop paying attention to objects if we tried. The visual brain guides attention largely by selecting objects 鈥 and this process is widely believed to be automatic.</p> <p>鈥淚 had an inkling that object-based attention cues require a little more will on the observer鈥檚 part,鈥 says Taylor. 鈥淚 designed an experiment to determine whether you can 鈥榚rase鈥 object-based attention shifting.鈥</p> <p>Taylor put a new twist on an old and highly influential test known as a 鈥渢wo-rectangle experiment.鈥 The original experiment was instrumental in demonstrating just how deeply objects are ingrained in how we see the world.</p> <p>In the original experiment, test subjects stare at a screen with two skinny rectangles. A brief flash of light draws their attention to one end of one rectangle 鈥 say the top end of the left rectangle. Then, a 鈥渢arget鈥 appears, either in the same place as the flash, at the other end of the same rectangle, or at one of the ends of the other rectangle.</p> <p>Observers are consistently faster at seeing the target if it appeared at the opposite end of the original rectangle than if it appeared at the top of the other rectangle 鈥 even though those two points are precisely the same distance from the original flash of light.</p> <p>The widely accepted conclusion was that the human brain is wired to use objects like these rectangles to focus attention. Alternately referred to as a 鈥渂ottom-up鈥 control or a 鈥減art of our lizard brain,鈥 object-based attention cues seemed to evoke an involuntary, uncontrolled response in the human brain.</p> <h3>New element added to research: colour</h3> <p>Taylor and colleague鈥檚 variations added a new element: test observers went through similar exercises, but they were instructed to hunt targets of a specific colour that either matched or contrasted with the colour of the rectangles themselves.</p> <p>鈥淭hey activate a 鈥榗ontrol setting鈥 for, say, green, which is a very top-down mental activity,鈥 says Taylor. 鈥淲e found that when the objects matched the target colour, people use them to help direct their attention. But when the objects were not the target colour, people no longer use them 鈥 they become invisible.鈥</p> <p>Test observers are aware of the rectangles on the screen, but when they鈥檙e seeking a green target among red shapes, those objects no longer affect the speed with which they find it. In everyday life, we continually create such top-down filters, by doing anything from heeding a 鈥淲atch for children鈥 sign to scanning a crowd for a familiar face.</p> <p>鈥淭his result tells us that one of the ways we move attention around is actually highly directed rather than automatic,鈥 Taylor says. 鈥淲e can鈥檛 say exactly what we鈥檙e missing, but whatever is and is not getting through the filter is not as automatic as we thought.鈥</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> <div class="field field--name-field-picpath field--type-string field--label-above"> <div class="field__label">picpath</div> <div class="field__item">sites/default/files/2016-03-21-perception.jpg</div> </div> Mon, 21 Mar 2016 06:50:07 +0000 sgupta 7745 at 茄子直播 physicists taking a cold look at atomic interactions /news/u-t-physicists-taking-cold-look-atomic-interactions <span class="field field--name-title field--type-string field--label-hidden">茄子直播 physicists taking a cold look at atomic interactions</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>sgupta</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2016-02-22T10:23:57-05:00" title="Monday, February 22, 2016 - 10:23" class="datetime">Mon, 02/22/2016 - 10:23</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"> Diana Tyszko.)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/patchen-barss" hreflang="en">Patchen Barss</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Patchen Barss</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/collaboration" hreflang="en">Collaboration</a></div> <div class="field__item"><a href="/news/tags/international" hreflang="en">International</a></div> <div class="field__item"><a href="/news/tags/research" hreflang="en">Research</a></div> <div class="field__item"><a href="/news/tags/more-news" hreflang="en">More News</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">Measurements of 鈥減-waves鈥 will aid understanding of superconductivity and other fundamental material properties</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Researchers led by <strong>Joseph Thywissen</strong> of the University of Toronto鈥檚 department of physics have discovered new rules governing the behaviour of atoms that collide at temperatures close to absolute zero.</p> <p>By adjusting the magnetic field surrounding these atoms and making observations through a process called dynamical spectroscopy, the researchers were able to measure correlations and find evidence for the laws governing <em>p</em>-wave interactions, which are rare in nature. The result could be new insights into superconductivity, superfluidity and other fundamental properties of materials.</p> <p>The research appears in a <a href="http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3670.html">paper </a>published on Feb. 22 in the journal <em>Nature Physics</em>.</p> <p>鈥淯ltracold atoms are the stem cells of materials science,鈥 says Thywissen, a professor of physics and fellow of the quantum materials program at the Canadian Institute for Advanced Research.</p> <p>鈥淛ust as a stem cell can become a fingernail or a heart cell depending on its context, ultracold atoms can become metals, insulators, superfluids or other types of materials.鈥</p> <p>In collaboration with theorists Shizhong Zhang of Hong Kong University and Zhenhua Yu of Tsinghua University, the Toronto scholars have been studying <em>p</em>-wave interactions in a highly controlled environment, coaxing a few hundred thousand gas atoms into a 鈥渢rap,鈥 and cooling them close to absolute zero (-273.15 Celsius).</p> <p>If two atoms hit head-on and bounce straight back from one another, they have no angular momentum. This interaction is called an <em>s</em>-wave. But if a pair of atoms ricochet off one another with a single unit of angular momentum, the resulting interaction is known as a <em>p</em>-wave.</p> <p><em>P</em>-waves,<em> s</em>-waves and other types of atom-pair interactions correlate with many types of emergent physical properties. Some rules that govern these relationships are well understood, but those related to <em>p</em>-waves have traditionally defied explanation.</p> <p>鈥<em>P</em>-wave interactions fascinate scientists because they endow materials with unusual properties and puzzling behaviours,鈥 says Thywissen. 鈥淏ut the conventional wisdom was that gases with <em>p</em>-wave interactions had losses that were too strong to allow you see anything interesting.鈥</p> <p>Thywissen鈥檚 team employed dynamical spectroscopy to prepare and probe atoms faster than had been done in the past.</p> <p>鈥淥ur observations took less than a millisecond,鈥 he says. 鈥淧revious studies were searching for properties that required longer observation. It allowed us to see something before the losses became too significant.鈥</p> <p>Their orthodoxy-challenging experiments resulted more from serendipity than a conviction that there was a problem with conventional wisdom.</p> <p>鈥淲e ended up looking at this because a graduate student working in our lab didn鈥檛 know how to avoid the <em>p</em>-wave resonances,鈥 Thywissen says. 鈥淗e took spectroscopy data on them. Nature surprised us. There was a beautiful spectroscopic signal of a new kind of pressure that was due to <em>p</em>-wave interactions.鈥</p> <p>Their subsequent observations sparked a flurry of activity among theoretical physicists, resulting in several papers that attempted to explain this pressure. If correct, this theoretical work provides a new set of guidelines outlining how to understand any state of matter that emerges from <em>p</em>-wave interactions.</p> <p>This work can help scientists better understand the fundamental question of where material properties come from. It can also make it possible to create and work with new materials that have highly unusual 鈥 and potentially very valuable 鈥 properties.</p> <p><em>P</em>-waves, for instance, correlate with unusual forms of superconductivity and superfluidity, in which particles flow without resistance. Such materials have vexed scientists for years.</p> <p>鈥淲hen made up of <em>p</em>-wave pairs, superconductors and superfluids should also have something called an edge current 鈥 but we know from observation that these edge currents are absent or extremely weak,鈥 says Thywissen. 鈥淲e don鈥檛 understand this. We hope the new relations we鈥檝e discovered will help us figure out why.鈥</p> <p>Thywissen and his collaborators are already designing new experiments designed to tune and tweak the environment, creating an even more sophisticated understanding of how material properties emerge.</p> <p>鈥淓ven though this experiment looks complex now, we will continue to work to push the limits of what can be done in the lab,鈥 Thywissen says. 鈥淲e never know what we鈥檙e going to find, but we always have hope of discovering something like this. It is truly thrilling.鈥</p> <p>Research was carried out at 茄子直播 by PhD candidates <strong>Christopher Luciuk</strong> and <strong>Scott Smale</strong>, and postdoctoral fellow <strong>Stefan Trotzky</strong>, in addition to Yu, Zhang and Thywissen.</p> <p>&nbsp;</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> <div class="field field--name-field-picpath field--type-string field--label-above"> <div class="field__label">picpath</div> <div class="field__item">sites/default/files/p-waves.jpg</div> </div> Mon, 22 Feb 2016 15:23:57 +0000 sgupta 7665 at