Science Café 2016-17
Wednesday, September 28, 2016
X Rays: from Röntgen to digital radiography and beyond
Paul Johns | Department of Physics
X rays are the key technology of hospital imaging departments, and are also used in dentistry, industry, and for security scanning. X-ray technology was the first to allow a doctor to look inside a patient without surgery. Today, hospitals have many other technologies including ultrasound, mri, and nuclear medicine. Yet x-ray technology, including the CT scanner, continues to be a major workhorse and continues to evolve to provide better and more convenient images with acceptable radiation dose. Starting with the inception of x-ray imaging at the close of the 19th century, this talk will trace the development of x-ray technology through today’s computerized machines and on to the future in which we will exploit the wave nature of x rays as well as their particle nature. We will look at where x-ray imaging is likely to go, and introduce some of the people behind the science.
Wednesday, October 12, 2016
Can computers generate creative designs for everyday objects?
Oliver van Kaick | School of Computer Science
Computer tools for modeling 3D shapes have become quite advanced. These tools are used for the development of computer games, special effects in movies, and even for the design of everyday objects such as chairs, tables and vases. However, in the context of design, much of the modeling work is still done manually by a user or artist, while the computer tool mainly ensures that the designed shapes can be appropriately drawn on the screen and fabricated in the real world. One interesting question is whether we can go one step further and let computers automatically model designs of everyday objects, especially designs that require a certain level of creative thinking. In this talk, I would like to explore this question and present a few research works that take a step in this direction. The main idea of these works is to provide inspiration to the artists by automatically creating interesting variations of shape designs with computers; the artists can then take the computer-generated designs and refine them into final products. In more detail, I will talk about how to generate shape variations by recombining existing shapes in novel ways, and how to ensure that the synthesized shapes still function appropriately, that is, verify that they serve their intended purpose.
Wednesday, October 26, 2016
Mathematics of gambling and some common gambling fallacies
Jason Gao | School of Mathematics and Statistics
Gambling, according to the dictionary, refers to an activity which risks something of value in order to obtain a reward. Typical examples are casino gambling, sports betting, and buying lotteries. In this talk, we will first briefly discuss why people gamble and what are problem gambling. Then we will talk about some gambling fallacies and the crucial role of mathematics/statistics in the study of gambling. Simple examples such as roulette and lottery will be used to illustrate some fundamental concepts such as house edge, volatility, and law of large numbers.
Wednesday, November 9, 2016
Sexual selection and mate choice: how and why animals are choosy when seeking mates
Jean-Guy Godin| Department of Biology
In nature, most animals do not mate randomly with members of the opposite sex, but rather are choosy when seeking mates. Because females generally pay higher costs of reproduction and have a lower reproductive potential than males over their lifetime, they tend to be coy and more selective of prospective mates than males and males compete among themselves for access to females and invest more in traits (such as courtship displays and ornaments) that are sexually attractive to females. Charles Darwin was the first to propose in the mid-19th century an evolutionary process - ‘sexual selection’ - to explain the ubiquity in nature of female mate choice and elaborate, costly sexual traits in males (for example, the elaborate tail and courtship displays of peacocks) that function to attract females and enhance competitiveness for mates. In this public talk, I will briefly summarize, using examples from the published literature and from my own research on fishes, how females choose mates and the reproductive benefits they may gain in doing so. Recent research on the use of social information by individuals in making mating decisions will be also briefly introduced.
Wednesday, January 11, 2017
Staying safe online: exploring cyber threats and protection strategies
Sonia Chiasson | School of Computer Science
Why do users behave insecurely even though most will readily state that security and privacy are important? We will cover some of our recent research exploring reasons why users' actions do not necessarily reflect their desire for security and how the configuration of security systems may actually weaken security in practice. We will discuss the main cyber threats faced by end-users, demonstrate some of our interactive educational material for improving digital literacy, and discuss realistic strategies for reducing risks while still enabling users to pursue online activities.
Wednesday, January 25, 2017
Uninvited guests in our homes: all things visible and invisible
David Miller| Department of Physics
In less than one generation, the percentage of time spent indoors has greatly increased. There are Canadian data spanning 40 years. In Canada, between 1975 and 1995, children spent 20% more time indoors and in transit and from 1995-2015, a further 15% more time indoors is being spent indoors compared to 1995. We are not alone in our homes. Aside from the microbes and insects we (and our pets) bring indoors, there is a whole (new) ecology of mites, insects, bacteria, and fungi that live with us. Over the past 8 years, I have been part of a team developing clinical practice parameters from the American Academy of Allergy Asthma and Immunology (AAAAI). These help allergy doctors advise their patients with allergens that occur mainly indoors (furry pets, rodents, cockroaches, dust mites, fungi). There are a number of common sense things that that can be done to reduce exposure to these allergy/asthma triggers.
Wednesday, February 8, 2017
The fascinating stories rocks can tell: from nanoscale processes in Earth’s most complex material to the collision of continents
Fred Gaidies| Department of Earth Sciences
Some of the most elemental properties of our planet’s crust include its behaviour during plastic deformation, the way it transmits seismic waves, or the rate with which thermal anomalies form and dissipate in response to tectonic processes. I will use this talk to introduce you to modern metamorphic petrology - that branch of geology that is concerned with the mineralogical and microstructural changes that occur when rocks of our planet’s crust get buried and heated inside the Earth. Unmetamorphosed rocks like granite or mudstone turn into metamorphic rocks when involved in the collision of continents. One of the most spectacular examples of metamorphism that is currently ongoing can be studied in the Himalayas where India collides with Asia. Rocks get heated and deformed during burial and recrystallize into metamorphic rocks such as gneisses or schists forming the roots of the mountain chain. Erosion of the mountains exposes metamorphic rocks at the surface where we can study their mineral content and microstructure to infer the tectonic processes responsible for their formation. Considering that tectonic processes have been documented over most of our planet’s history, the correct deciphering of the mineralogical and microstructural information contained in metamorphic rocks helps us to understand how Earth’s crust has behaved since its birth.
Wednesday, February 22, 2017
Ethical birding for the everyday naturalist
Shawna Masson | Department of Biology
Bird watching comes with a code of ethics enthusiasts abide by. These practices help us protect the pastime we love so dearly. With bird watching these rules mean so much more, as they help protect the birds and their natural ecosystems. Human presence can be very intrusive and destructive to wildlife without proper precautions. What safeguards can birders use to ensure the continued enjoyment of bird watching? In this presentation we will discuss guidelines to avoid unintentionally disturbing or harming our feather friends. Even as an experienced birder, we can be unknowingly disturbing the wildlife we aim to conserve.
Wednesday, March 8, 2017
Using Human stem cells for treating and understanding diabetes
Jenny Bruin | Department of Biology
Diabetes is a chronic disease with devastating complications and an enormous global impact. There are currently 3.5 million people in Canada and more than 415 million people worldwide with diabetes, and these numbers are continually rising. Diabetes is characterized by high blood sugar levels, resulting from insufficient production of insulin from beta cells. Insulin-secreting beta cells are located within cell clusters in the pancreas called ‘islets’. Remarkably, infusion of islet cells from a deceased organ donor can effectively reverse diabetes, but this clinical approach is severely limited by the lack of suitable organ donors. Human stem cells are a promising alternative cell source for transplantation because of their potential to be directed into all cell types in the human body, including insulin-secreting beta cells. I will discuss how we have used human stem cells to reverse diabetes in mice and how stem cells are currently being tested in clinical trials here in Canada. I will also talk about the utility of human stem cells as a novel model system for studying the underlying causes of beta cell destruction and dysfunction in diabetes. By better understanding the root causes of diabetes, we hope to prevent the development of this disease long before treatment is required.
Wednesday, March 22, 2017
The Flaws of nature
Andrew Simons| Department of Biology
The living world seems to provide an endless array of examples of exquisitely designed features: adaptations that allow survival under harsh conditions, that provide impeccable camouflage, that entice insects to transfer a flower’s pollen, etc. However, some features seem to make absolutely no sense from a design perspective. A famous example is the panda’s “thumb” fashioned from the wristbone. Using the power of errors to reveal how things work, Dr. Simons will explore examples of what appear to be natural bloopers and how they can be understood within an evolutionary framework.