Lecture Series

before Fall 2005

1995 and 1996

Sunday, January 29, 1995

Morals and Metaphors: Physics and Technology

Bertram N. Brockhouse, Ph.D., O.C., Professor Emeritus, Department of Physics, McMaster University, Hamilton, 1994 Nobel Laureate

In 1950 the speaker began a career in neutron physics that culminated in the award of the 1994 Nobel Prize in Physics for his part in the long-ago institution o f a new field of physics ­­ Slow Neutron Spectroscopy. This field involves the use of a beam of neutrons to study the way atoms behave in a specimen of physical matter. Like atoms, neutrons are terms in any theory (of physics) that purports to describe the matter of the specimen. Hence neutrons are ideal probes to test the goodness of a theory. But has this anything to do with the title? Yes.

Sunday, February 5, 1995

The Biology of Plant Invasions

Spencer C. H. Barrett, Ph.D., Department of Botany, U of T

Plant populations usually migrate and multiply slowly over time as a result of the natural interplay of many ecological factors. Yet during the past century human activities have quickened the pace of change by dramatically altering the range and abundance of many plants. In some cases where plant invaders have entered new regions to dominate ecosystems this has led to ecological as well as economic disasters. Where do plant invaders come from? What features make them so successful? And how might we control their populations? These issues will be addressed using examples of plant invasions from different regions of the world including the purple loosestrife invasion in Ontario and the spread of water hyacinth throughout tropical waterways.

Sunday, February 12, 1995

The Hunt for Genes is On

Katherine Siminovitch, M.D., F.R.C.P. (C)

We are witnessing, almost daily, discoveries that were inconceivable 20 years ago: the manufacture of recombinant human proteins for therapeutic use, the development of novel diagnostic assays for early disease detection and the identification of the genetic defects responsible for many diseases caused by single genes. These advances are largely the result of breakthroughs in a technology that has made it possible to isolate, characterize and manipulate the genetic material, DNA. The continued application of this technology holds enormous promise for moving medical practice beyond symptomatic treatment toward disease prevention and cure.

Sunday, February 19,1995

Global Warming Should Affect the Arctic Most.  Would It in Reality?

Josef Swoboda, Ph.D., Professor Emeritus, Department of Botany, U of T

The Canadian tundra regions will experience significant temperature increases if global warming continues for several more decades. The lush tundra above the treeline will be relatively quickly overrun by advancing boreal forest (already an observed process). However, the sporadically vegetated tundra of the High Arctic will respond slowly. Several factors may hold back the anticipated vegetation expansion: extremely cold and deep permafrost (in the High Arctic the past great glaciation has not terminated ­­ just gone underground); insufficient moisture in summer; and an inadequate supply of nutrients, mainly nitrogen. There is also a real possibility of a climatic flip-flop, a sudden and catastrophic climatic reversal due to factors to be explained and discussed.

Sunday, February 26, 1995

Electric and Magnetic Fields: Is There a Risk?

Ruth E. Greey, M.Sc., Senior EMF Consultant, Ontario Hydro; Lynn E.H. Trainor, Ph.D., Professor Emeritus, Department of Physics, U of T

Electric and magnetic fields (EMF) are produced by electricity, as well as by the earth itself. In the last 15 years, these fields, often taken for granted in our daily use of electricity, have been under scrutiny. Some scientific evidence has associated these fields with health concerns, specifically cancer, fatigue, miscarriages and more recently Alzheimer's disease. Is this scrutiny justified? Is there a potential heath risk? Even the best informed experts cannot be certain. We do know however that the re is no causal relationship between EMF and impaired health. Given the magnitude of the scientific research and the associated costs, what should society's next step be?

Sunday, March 5, 1995  

Engineers and Sustainable Development: Not So Improbable Now

Richard Cave, B.Sc., M.I.C.E., P. Eng., President, R. Cave and Associates Engineering Ltd.

Resolving technical aspects of some of the more pressing development issues of today is often relatively straightforward. The challenge more often stems from social, political and environmental factors. Engineers must now listen to (and heed) the public, politicians, and environmentally concerned specialty groups. "Consultation" and "consensus" are concepts with at least as much weight as traditional "technology". This requires a new mind set, radically different from the linear, numeric, single-minded, p roblem-solving approach of the traditional engineer, as it is often impossible to reduce these complex issues to a single solution, or even to a set of simple solutions.
To accord with Engineering Week

Sunday, March 12, 1995

Materials Chemistry on Three Length Scales: Learning From Nature

Geoffrey A. Ozin, Ph.D., Department of Chemistry, U of T

Molecule-by-molecule construction of hierarchically organized structures for uses from microelectronics to engineered biomaterials is a laborious process. A recent laboratory solution to this problem is to get molecules to recognize each other and build themselves. To actually orchestrate the self-assembly of materials with desirable features on microscopic (<10 Å), mesoscopic (10-500 Å) and macroscopic (> 500 Å) length scales requires a new way of thinking about chemical synthesis. The speaker will show how organic molecule assemblies, together with simple inorganic building-blocks, can organize into complex and beautiful materials full of ordered arrays of holes. They exhibit hierarchical structures and undergo novel restructuring reactions that resemble those found in some of nature's biominerals (e.g., skeletons, teeth, shells). Such studies inspire materials chemists to discover new ways of synthesizing advanced materials.

To accord with Engineering Week


Sunday, March 19, 1995

Seeing With Scanning Probe Microscopes

M. Cynthia Goh, Ph.D., Department of Chemistry, U of T

Visualization of very small structures, perhaps down to atomic detail, has been an important goal since the invention of the first microscope. Unfortunately, the traditional microscopes have an intrinsic limit to the size that can be seen. In the past ten years, a new way of seeing small objects, with the use of scanning probes, has revolutionized our picture of the submicroscopic world. Applications to visualization of atoms, molecules and proteins, such as those found in the brain of patients with Alzheimer's disease, will be shown.

Sunday, October 22, 1995

The p53 Gene and Cancer: The Family and Society

David Malkin, M.D., F.R.C.P. (C), Division of Oncology, Hospital for Sick Children, Department of Paediatrics, U of T

Hereditary predisposition accounts for approximately 10% of all human cancer. Studies of family clusters led to the discovery of a class of cancer susceptibility genes known as tumour suppressor genes. These genes are now known to be important in the development of virtually all types of cancer, both familial and sporadic. The p53 tumour suppressor gene is the most frequently altered gene in human cancer. Normal p53 appears to prevent cells from dividing when the DNA in these cells has in some way been damaged. Inherited abnormalities of p53 place carriers at risk of developing a wide range of tumours. Abnormalities of numerous other genes may lead to the development of distinct cancer clusters in families. The psychosocial, ethical, and legal implications of predictive genetic testing for cancer are complex. The science and philosophy of cancer genetics will be discussed.

Sunday, October 29, 1995

The Discovery of Truth:  How the Top Quark Was Found

Pekka K. Sinervo, Ph.D., Department of Physics, U of T

The theory that describes the fundamental building blocks of our world and the forces that hold them together to form atoms, molecules, and macroscopic structures predicted 17 years ago that an undiscovered type of hadronic matter had to exist. This prediction of the "standard model" is so fundamental to the model that, were it proved wrong, our picture of the world would require radical revision. Two teams of scientists, working independently at the world's highest energy matter-antimatter collider, announced in February 1995 the discovery of this new type of matter, the top quark (known as "truth"). The top quark is extremely massive, which explains, in part, why it has been so difficult to prove that it exists. The search for and discovery of the top quark will be described, and the impact of this finding on our understanding of the world will be explored.

Sunday, November 5, 1995

Psychosis and Dopamine Receptors

Philip Seeman, M.D., Ph.D., Department of Psychiatry and Pharmacology, U of T

Dopamine serves as a normal transmitter of messages between nerve cells in the brain. The psychotic state of hallucinations and delusions is caused by overactive dopamine transmission. Such overactivity arises from the release of too much dopamine, as in cocaine psychosis, or too many dopamine receptors, as in schizophrenia. Psychotic symptoms occur in several illnesses. All antipsychotic drugs act by blocking dopamine receptors. There are five types of dopamine receptors. Types 2 and 4 are elevated in schizophrenia. These receptors have now been isolated, permitting the discovery of more selective drugs against psychosis.
Joint session with Ontario Friends of Schizophrenics

Sunday, November 12, 1995

Memory, Consciousness, and the Brain

Endel Tulvig, Ph.D., F.R.S.C., F.R.S., Tanenbaum Chair of Neuroscience, Rotman Research Institute of Baycrest Centre

The mental phenomena of memory and consciousness, and how they arise from the activity of the brain, have for a long time been among Nature's most jealously guarded secrets. Now, gradually, scientists are beginning to solve the puzzle. Recent cognitive, neuropsychological, and neuroimaging studies of healthy individuals and amnesic patients have revealed facts about conscious and nonconscious memories that were not just unknown but totally unexpected only a few years ago. This lecture reviews some of the fresh insights into the brain/mind processes of how people know things and remember events.

Sunday, November 19,1995

Power Play

Edward J. Barbeau, Ph.D., Department of Mathematics, U of T

Powers of the ordinary whole numbers have fascinated people since the ancient Babylonians played around with Pythagorean triples. While powers of numbers have instigated incredibly profound mathematics, witness Wiles's proof of the notorious Fermat conjecture, they have also nurtured a rich recreational tradition. Come to a mathematical concert and savour some surprising relationships about the numbers you thought you knew so well. Discover a magic square of squares; experience the power of the Fibonacci sequence; learn a simple modern method of expressing certain prime numbers as the sums of two squares.
Joint session with the Fields Institute for Research in Mathematical Sciences

Sunday, November 26, 1995

Forensic DNA Analysis: Pitfalls and Promises

Pamela Newall, B.Sc., M.A., Head of Biology Section, Centre of Forensic Sciences, Toronto

Recent high profile cases have catapulted the forensic application of DNA analysis onto the front pages of our newspapers. Are the tests reliable? What do those huge numbers mean? What about contamination? Will I understand the results? Each case is different, poses different questions, and provides different samples for study. Although 17 polymorphic DNA loci can be analyzed at the Centre of Forensic Sciences, in any one case it may be possible to obtain results at one locus only. The information value of that test may exclude 4 out of any 5 people and may match the accused. However, that 1 in 5 occurrence could also be a match for thousands of possible contributors. Conversely, the results may produce a composite profile with a frequency so rare that one would not expect to see it again. We will review sample cases of DNA analyses that have been evaluated by Ontario juries and question the strengths and weaknesses of those tests.

Sunday,December 3, 1995

Children’s Science Workshop

George Vanderkuur, B.Sc., Consultant, Toronto Board of Education

Children ages 7-14 accompanied by adults will be admitted first. Exciting demonstrations, hands-on activities, and ideas for things to do at home. Refreshments.

Sunday, January 28, 1996

Women Scientists: Current Issues and Realities. a Panel Discussion

(Joint with the Women in Science  Committee, U of T)

Moderator: Heather Munroe-Blum, Ph.D., Vice-President of Research and International Relations, U of T;  Coordinator: Dina Gordon Malkin, M.D., Faculty of Medicine, U of T, President, RCI;  Panel:  Rona Abramovitch, Ph.D., Status of Women Officer, U of T; Nancy Reid, Ph.D., Department of Statistics, U of T; Allison Sekuler, Ph.D., Department of Psychology, U of T; Susan Tallett, M.B., B.S., F.R.C.P. (C), Department of Paediatrics, Director of Medical Education, Hospital for Sick Children; Ann Zimmerman, Ph.D., Department of Zoology, Director, Division of the Environment, U of T

Sunday, February 4, 1996

Uncertainty, Surprise, and the Limits to Prediction

Crawford S. Holling, Ph.D., Department of Zoology, University of Florida, Gainesville, FL

It is now clear that human activities are exerting a new and sustained influence on the whole planet, through accumulation of greenhouse gases in our atmosphere, the "Ozone Hole", emergence of new diseases, and precipitous decline and extinctions of species. Entirely novel connections are forming and intensifying, resulting in the early destabilized phase of a lurch of coevolution between humans and natural systems, for the first time on a planetary scale. The future is not just uncertain; it is inherently unpredictable. How can we read the signals? How can we respond?

Sunday, February 11, 1996

Light Information

Henry M. Van Driel, Ph.D., Department of Physics, U of T

Light has always played a central role in human existence. As we move forward in the Information Age, "photons" (particles of light) are increasingly replacing electrons as the fundamental carrier of information in a wide range of technologies. Can the transformation ever be complete, and what are the limitations posed by light? Indeed, what are the limitations imposed by physics, in general, with respect to information applications, and what directions are likely to be taken by technology in the future?

Sunday, February 18, 1996

Blood Substitutes and Beyond

Ronald Kruger

The red cells circulating in blood carry oxygen to all body tissues. Within these cells oxygen binds to the protein hemoglobin. The primary function of blood transfusion is the replacement of lost red cells. Whole red cells cannot be sterilized and must be matched for blood types. In principle, sterile solutions of hemoglobin itself, removed from cells, should be able to perform oxygen transport and be universally compatible. However, hemoglobin becomes potentially harmful because it changes outside the red cell. In response to this problem, we developed chemicals that specifically modify hemoglobin so that it can be used in place of red cells. The chemistry involved also extended in new directions beyond blood substitutes. These new designs permit the modified hemoglobin molecule to be a basis for developments to serve other needs, such as delivering and stabilizing medicines.

Joint with the Department of Chemistry, U of T

Sunday, February 25, 1996

Romancing and Deciphering the Stone - the Emerald Mines of Colombia

Terri Ottaway, Earth Sciences Department, Royal Ontario Museum

For over 1,000 years the mines of Muzo and Chivor in the Colombian Andes have been the source of the world's finest emeralds. The deposits were initially worked by Indians, then by the Spanish Conquistadors, and are still in production today. To a geologist, the deposits are quite enigmatic. Emerald is the blue-green variety of the mineral beryl. As such, emerald deposits the world over are associated with igneous rocks called pegmatites, the source of emerald's key ingredient, beryllium. However, by a bizarre twist of nature, there are no pegmatites associated with the fabled Colombian deposits. With isotopes and fluid inclusion microthermometry we now understand the unique conditions present at the time of emerald formation. You will never look at inclusions in emeralds as flaws again!

Sunday, March 3, 1996

The Class of 2000: Integrated Knowledge and Community Service

Ursula Franklin and students

Ursula Franklin and four Grade Nine students from the Ursula Franklin Academy in a lively exploration of the underlying philosophy of a new school model, founded on integrating mathematics, science, and technology across the curriculum. In today's world where there is more novelty than tradition and where the significant activity occurs at the intersection of disciplines, students are becoming aware of the interconnectedness of knowledge and the social responsibility that goes with the privilege of its acquisition. The panel discussion and introduction by Dr. Franklin will also allow extra time for audience participation.

Joint with the Ursula Franklin Academy

Sunday, March 10, 1996

Impact Earth

Brian G. Marsden, Ph. D., Director, Minor Planet Center, Harvard-Smithsonian Center for Astrophysics

In July 1994 at least a score of fragments of a comet collided with Jupiter. Although the impacts were predicted 14 months earlier, nobody anticipated the resulting large black jovian splodges that could be seen with a small telescope. How would humanity have coped with the knowledge of impending doom, and how would our planet have fared if the earth had been the target instead? It is widely believed that the extinction of countless terrestrial life forms, including the dinosaurs, was due to impacts with comets and asteroids in the past. Such impacts during the twentieth century have been small, although that over Siberia in 1908 had a devastating effect within a radius of many tens of kilometres. If a larger object were headed our way, could we save ourselves from the fate of the dinosaurs?

Joint with the Royal Astronomical Society of Canada

Sunday, March 17, 1996

Environmental Scarcities and Violent Conflict in Developing Countries

Thomas Homer-Dixon, Ph.D., Department of Political Science, U of T

If scarcities of renewable resources -- such as cropland, forest, fresh water, and fish -- become severe, could they precipitate violent civil or international conflict? The lecture reports the results of an international research project that addresses this question. The research shows that environmental scarcities are already contributing to violent conflicts in many parts of the developing world. Moreover, these conflicts are probably the early signs of an upsurge of violence in the coming decades that will be induced or aggravated by scarcity. The violence will usually be sub-national, persistent, and diffuse; and poor societies will be particularly affected since they are less able to buffer themselves from environmental scarcities and the social crises they cause.

Sunday, October 27, 1996

Science Education: Everyone’s Business

John R. Percy, Ph.D., Department of Astronomy, U of T

Awareness, understanding, and appreciation of science and technology are beneficial to the health of Canadians' minds, bodies, and pocketbooks; this belief has guided the work of the RCI since 1849. Unfortunately, the state of science education and literacy in Canada leaves something to be desired, and it is tempting to blame governments, teachers, students -- anyone but ourselves. But there is hope! Around the world, individuals and groups are discovering ways to enhance science education and literacy. Following their example, scientists, teachers, and other interested Canadians -- including you -- can work together to promote more and better science education in the classroom and beyond. Examples will be drawn from the speaker's own field of astronomy, but the underlying principles are universal.

Sunday, November 3, 1996

Changing Our Concept of Women’s Health: Challenging Our Society

May Cohen, M.D., Department of Family Medicine, McMaster University, Hamilton

The understanding of women's health has evolved over the years, with an increasing awareness that biology is not the sole factor. Other factors that influence women's health include the social, political, cultural, and economic context of women's lives. Central to this understanding of women's health and their health care is the concept of gender as a major determinant of health. This talk will address the changing concept of women's health, and implications for the development of health care policies, educational programs, and research agendas.

Sunday, November 10, 1996

Psychiatric Distress in Women and Men

Mary Seeman, M.D.C.M., F.R.C.P. (C), Head, Schizophrenia Program, Department of Psychiatry, U of T

Women's and men's brains show subtle difference in structure and function. For complex reasons, the psychiatric disorders most common to women are not those most common to men. There are difference in rates of illness, severity, and in responses to treatment. Significantly, though, these marked differences often do not emerge until after the age of puberty.  And, in later years, the differences may disappear or -- paradoxically -- stand out in ever greater relief.

Sunday, November 17, 1996

75 Years of Insulin Therapy: Successes and Failures

Bernard Zinman, M.C.C.M., F..R.C.P. (C), F.A.C.P., Department of Medicine and Director, Banting and Best Diabetes Centre, U of T

The discovery of insulin at the University of Toronto in 1921 by Fred Banting, Charles H. Best, James Collip, and J.J.R. MacLeod revolutionized the management of Type I diabetes (insulin dependent diabetes mellitus). Unfortunately, despite our best efforts at therapy, diabetes remains a leading cause of blindness, non-traumatic amputation of the lower extremities, and end state renal disease. Diabetes also is a major risk factor for cardiovascular and cerebral vascular disease. The Diabetes Control and Complications Trial (DCCT) demonstrated conclusively that the risk of developing the long term disabling microvascular complications of diabetes can be decreased dramatically when glycemic control is improved with intensive therapy. Unfortunately, the implementation of intensive therapy is not achieved easily, and it is associated with an increased risk of severe hypoglycemia. The development of innovative approaches to improve glycemic control is needed urgently, and hopefully will facilitate the translation of research findings to the clinical setting.

Sunday, November 24, 1996

Disease Resistance in Plants: Healthy Tomatoes on Demand

Verna Higgins, Ph.D., Department of Botany, U of T

Genetically determined resistance of plants to infection by fungi, bacteria and viruses is utilized widely to protect our major food crops. Recent molecular and biochemical studies illustrate the complexity of the plant resistant response. A "burst" of hydrogen peroxide from affected cells suggests some analogy with the mammalian immune system. A discussion of research concerning tomato leaf mould will illustrate the progress in our understanding of disease resistance, and how this knowledge might help in bioengineering plants for resistance to a broad spectrum of plant diseases.

Sunday, December 1, 1996

The Century of the Mind: Exploring the Frontiers of the Brain

Donald T. Stuss, Ph.D., Director, Rotman Research Institute, Baycrest Centre for Geriatric Care; Departments of Medicine (Neurology) and Psychology, U of T

Over the past 150 years, scientists have made significant inroads to understanding how the brain controls different functions, such as perception, movement, and thought. Until fairly recently, however, certain areas of the brain were thought to control no particular function. At the same time, disease or injury in these areas often could lead to dramatic changes in personality and mental functioning. One such area is the frontal lobes, which account for approximately one third of the total mass of the brain. Advances in brain scanning techniques now are enabling scientists to study the brain in action, and are revealing the importance of the frontal lobes in the key functions that are uniquely human -- including conceptual though, decision making, and self-awareness.

Sunday, December 8, 1996

Children’s Science Workshop

Ivan Semaniuk, B.Sc., Ontario Science Centre

A fun-filled hour during which children (ages 7-12) will learn about the wonders of astronomy. Find out how to identify planets, stars, and comets in your local sky. There will be demonstrations with plenty of active participation by the audience. Refreshments will be served after the workshop.

Webcasts are not available for lectures prior to the Fall of 2005.

You can click on the appropriate years at left to see

the RCI’s speakers and topics for those years.