Science Café 2008-09
Wednesday, September 10, 2008
Farming fish for the future
George Iwama| Dean, Faculty of Science
Fish are being raised for food and for the enhancement of wild populations, yet there are concerns about the safety of eating farmed fish. Should we continue to hunt and gather this important food? Should we trust the farmed product?
Wednesday, September 24, 2008
Chemical pesticides: panacea or poison?
Dr. Tyler Avis | Department of Chemistry
The discovery and use of the pesticide DDT produced a Nobel laureate and a bestselling book with a somber message (Silent Spring). Unsurprisingly, synthetic pesticides have been described as both the greatest advancement in agriculture and one of the biggest threats to health and the environment. This talk will focus on the use of pesticides in today’s ‘green revolution’ and on the state of research on alternative methods to control pests in agriculture. What would happen if all pesticides were banned tomorrow? Can we continue to live with pesticides? Can we live without them?
Wednesday, October 8, 2008
Volcanic Hazards and Volcanoes in Western North America
Dr. Brian Cousens | Department of Earth Sciences
Nearly twenty percent of the Earth’s human population lives within eruptiondistance of an active volcano. Volcanic soils are very fertile, and farming can often extend well up the flanks of a volcanic edifice. Some volcanoes, such as those that form the Hawaiian islands, erupt fairly passively and generally do not constitute a hazard to life but can cause significant property damage.Other volcanoes, such as those in Indonesia and western North America, can erupt suddenly and explosively and constitute a huge hazard to the surrounding population. This talk will outline the geological hazards associated with four types of volcanoes: shield, composite, cinder cone and caldera. Hazards at shield volcanoes include lava lows, volcanic gases, faults and slumps. Cinder cone eruptions not usually lifethreatening, but the example of Paricutin in Mexico demonstrates the economic impact these eruptions can have. Composite volcanoes are much more dangerous, commonly producing swiftlymoving clouds of hot gas, lava fragments, and volcanic ash called pyroclastic flows or nuee ardentes. The great height of most composite volcanoes makes them susceptible to landslides, and snow and ice capping these volcanoes can melt during an eruption to produce fastmoving mudflows. Ash from composite volcano
eruptions can be injected high into the atmosphere, and these fine particles can block sunlight and influence global climate. Calderas are produced after a large eruption when magma from a shallow magma chamber is evacuated, leaving a space that allows roof rocks to collapse downwards. Recent caldera-related eruptions at Yellowstone National Park produced 4000 times the volume of volcanic materials erupted by Mt. St. Helens in 1980, and partially-solidified magma still exists beneath Yellowstone making this region a large volcanic hazard. Finally, we need to think geologically: Is it reasonable to allow the city of Naples to continue to grow around the base of Mount Vesuvius, ignoring the lessons of Pompeii and Heculaneum?
Wednesday, October 22, 2008
Security and Online Banking
Dr. Paul Van Oorschot | School of Computer Science
When I read my Online Banking Agreement (the user agreements from most of the major Canadian banks are similar), the language worries me. What worries me more is my understanding of the insecurity of today's browserbased software infrastructure, and the security vulnerabilities and breaches I read about regularly. In this talk I'll touch on some of these user agreements as well as some of the vulnerabilities (including keyloggers and attacks exploiting common browsers). I'll also ask the question: why do the banks' marketing messages, which can be simplified as "bank online with 100%
guarantee of security", differ so dramatically from the legal terms asserted in online banking agreements?
Wednesday, November 5, 2008
Dam Builder: Beavers and their ponds
Mike Runtz | Department of Biology
Beavers are remarkable rodents that not only are our official national animal but that also possess remarkable adaptations
for their lifestyle. They also are one of the few animals in the world that create their own habitat, which supports myriad
other plants and animals.
Wednesday, November 19, 2008
Constructing Nanotechnology with Nature’s Tools
Dr. Maria DeRosa | Department of Chemistry
DNA may be best known for carrying the genetic blueprint for all living things but recently it has become part of the construction materials in the exciting, but controversial field of nanotechnology. Nanotechnology seeks to make and manipulate useful devices on an extremely small length scale (billionths of a metre). As Nature has been very successful working at this length scale, it makes sense to look to biological building blocks, like DNA, for use in nanotech. In this talk, we’ll look at some of the latest advances in DNA nanotechnology. Come learn how “DNA origami” might revolutionize
electronics. How far away are we from useful DNA nanomachines? What concerns about DNA nanotechnology are real and what is just Fearmongering?
Wednesday, December 3, 2008
Battling beetles with ESP: Insights and applications from research on animal sensory systems
Dr. Jayne Yack | Department of Biology
Animals have evolved a stunning diversity of specialized sensory organs that allow them to sense the physical world far beyond our own experience. Through research on these sensory systems, we now know that elephants can communicate over several kilometers using infrasound, birds can 'see' the earth's magnetic field, and that many fish communicate using electric currents. Research on these unique sensory systems allows us to learn more about our own sensory processes, develop improved conservation and pest management practices, and provides ideas for discovering novel technical
sensors. I will talk about the importance of research on insect bioacoustics and specifically, how it can be used to manage destructive beetles such as the mountain pine beetle and emerald ash borer.
Wednesday, January 14, 2009
Cacti: Images from Brazil, Old Mexico, New Mexico...and Kaladar!
Dr. Root Gorelick | Department of Biology
Cacti are one of the most morphologically diverse plant families, despite not having a huge number of species. My research
is on discerning where all this diversity comes from, such as a predilection for duplicating all chromosomes and
developmental plasticity. However, for this talk, I simply want to introduce you to the amazing architectural diversity of cacti,
from christmas cactus to prickly pear to saguaro, and the starkly beautiful environments in which these grow, from Brazil to
Mexico to Canada. Familiarity with real organisms drives any good evolutionary theory, and so we should first appreciate
the beauty of these beasts.
Wednesday, January 28, 2009
Ottawa Valley faults as primary control on the city's limestone building heritage
George Dix | Department of Earth Sciences
The City of Ottawa rivals the stonebuilding status of Kingston because of a quirk in geological history of the Ottawa Valley some 450 million years ago. In the Late Ordovician period, some of our presentday faults (Gloucester, Hazeldean) were active or created. Recent research demonstrates that a similar structure must have been present along the SWNE axis of the Ottawa River separating Gatineau and the City of Ottawa. Development of this structure transformed the region's depositional setting such that shallowwater, high energy conditions prevailed. The result was accumulation of coarsegrained crinoidal limestones (sigh . . . we were positioned in the tropics at the time), now defined as the Hull Formation. This rock type forms the vast majority of common building stone in the City of Ottawa, and further illustrates the inseparable economic, social, and historical associations that characterize urban geology.
Wednesday, February 11, 2009
Green biotechnology: Harnessing plant biomass forbiofuels and biomaterials
Owen Rowland | Department of Biology and Institute of Biochemistry
Plants are our greatest source of renewable resources providing food, medicines, industrial bioproducts, and biofuels. However, in the past 100 years or so, our society has become heavily dependent on nonrenewable fossil fuels (e.g. oil and coal) as sources of energy and chemical feedstocks. This is not sustainable. The replacement of petroleumbased products with renewable agriculturalbased products is one of the most urgent tasks that human society faces today. Plant biologists and biochemists are at the forefront of developing strategies to sustainably harness plant biomass to meet our energy and industrial needs. I will discuss the opportunities and challenges in this fascinating and emerging area of biotechnology.
Wednesday, February 25, 2009
Water blues: Bottled water vs. tap water
Banu Örmeci | Department of Civil and Environmental Engineering
The war between bottled and tap water is getting bigger everyday. Advertisers spend millions of dollars each day to convince public that bottled water comes from pristine mountains and is better and healthier than tap water. Some local governments have begun to fight back, and there is now a growing environmental and political opposition to bottled water. This presentation will provide facts on the safety, quality, and cost of bottled and tap water, and will discuss the health and environmental concerns from all angles.
Wednesday, March 11, 2009
Mold in homes and public health: Is there a fungus among us?
Dr. David Miller | Department of Chemistry
One of the vexing problems that has arisen since the early 1980s is the increased incidence of mold damage indoors in homes, schools and public buildings. Prior to 1980, Canadian homes leaked a lot of air and were built of materials that did not support mold growth. After the first energy crisis, air change rates were reduced and less mold resistant materials were employed. It turns out that in a family of four, somewhere between 2 and 7 kg of water vapour goes into the air 24/7 from cooking, washing, showers & the like. If this is not removed, the building materials gain moisture and mold can grow. Another change was the older buildings were designed to cope with leaks because the builders knew they would. Many modern buildings depend that the exterior cladding and caulking will not fail. This is correct if properly built and maintained. That public health might be affected by interior mold growth was first articulated in the Old Testament and from a scientific perspective fairly clear from the late 1960s. As with many things, this fell off the table for half a generation and prior to 1988 the view was that mold in buildings was ugly but not a health problem. In large part due to work done in Canada, this view has returned to the older view such that in 2004, Health Canada, the United States National Academy of Sciences and the World Health Organization are clear that mold and dampness in buildings is harmful to public health. This is a problem that requires occupants, designers and builders to contribute to manage the problem which is different than many health problems that are best fixed by government alone. I will reflect on the historical journey and some things that people can do to improve the indoor environmental quality of their homes and schools.
Wednesday, March 25, 2009
The Large Hadron Collider: A particle smasher designed to answer the fundamental question about our Universe
Louise Heelan | PhD candidate, Department of Physics
The Large Hadron Collider (LHC) is a particle smashing machine located at CERN, on the FranceSwitzerland border in Geneva. This project hopes to recreate conditions just after the Big Bang. At this energy and density the goal is to further probe the basic constituents of matter and the forces that govern their interactions. The Standard Model of Particle Physics has been used for decades to predict new particles and their associated forces; one piece of this model remain undiscovered, the Higgs Boson, a critical piece that provides mass to the other particles. However, alternative theories exist
that predict new, different particles, including a theory that explains dark matter. Massive detectors located around the LHC, such as ATLAS, hope to detect the Higgs Boson and search for signatures of alternative theories. This talk will introduce the Standard Model of Particle Physics, describe the design and goals of the LHC and the ATLAS detector and help us to understand why dark matter matters.
Wednesday, April 8, 2009
Food Supplements: What do they promise? What do they deliver?
Apollinaire Tsopmo | Department of Chemistry
We often read exciting headlines reporting some remarkable new discovery about potential health benefits from eating foods that contain certain types of nutrients or substances known as phytochemicals. Other terms associated with these bioactive compounds are nutraceuticals, functional foods, antioxidants, essential fatty acids, polyhenols, dietary fibers, phytoestrogens, probiotics. They have been reported to prevent or reduce the incidence of many diseases e.g. cardiovascular diseases, cancer, diabetes, neurodegenerative diseases. How do scientists view phytochemicals in foods?Do they work and are they safe to consume? I will talk about the role of some these bioactive substances, how they might work and some tips for consuming phytochemicals.
Wednesday, April 22, 2009
Leonardo Da Vinci and his mathematics
Angelo Mingarelli | School of Mathematics and Statistics
We will explore the mathematical world embraced by Leonardo Da Vinci (14521519), artist, engineer, all around renaissance man, and probably the greatest universal genius the world has ever produced. Among the questions we tackle we cite: Did he "hangout" with mathematicians? How much mathematics did he actually know? Did Leonardo use mathematics in his artistic compositions and works?
Wednesday, May 6, 2009
Songs for spring
Sue Bertram | Department of Biology
Spring bursts forth with melting snows, rapidly blossoming flowers, and swiftly returning birds. Spring also entails a sudden cacophony of sounds, which people seem to either love or hate. Bertram will discuss the sounds of spring that are presently inundating us. She will talk about the frogs, toads, and insects that are making such a ruckus. She will discuss why they call along with their typical order of appearance. She will also discuss the eavesdroppers; those predators and parasites that listen in and use the mating calls to a tasty meal or a suitable host to parasitize.
Wednesday, May 20, 2009
Seismic microzonation studies for the Ottawa region
Dariush Motazedian | Department of Earth Science
Carleton University, in collaboration with the Geological Survey of Canada, have been conducting microzonation measurements and analyses in the Ottawa area since 2005. Microzonation is the identification and subdivision of a region into separate individual zones that have different potentials for hazardous earthquake effects. Measurements and analyses of sites through the Ottawa City will continue resulting in a tool that provide the engineering and building communities with specific geological features in the Ottawa area and a new set of seismic soil amplification factors for different National
Building Code of Canada site classes and different levels of shaking, based on seismic hazard maps of Canada.