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Public Lecture Series Speaker: Ransom A. Myers, Killam Chair of Ocean
Studies at Dalhousie University, Halifax, Nova Scotia View postcard: PDF There has been a phenomenal loss of large predators in the ocean; within the last 50 years the abundance of large fish predators has been reduced by approximately 90%. What was once thought to be the most abundant large vertebrate in the world, the oceanic white tip shark, was 300 times more abundant off the coast of the southern US only 50 years ago than it is today. I will discuss the ecological consequences of this loss of predators, and how overfishing has drastically changed the world's oceans.Speaker: Thomas Kiorboe, Danish Institute for Fisheries Research View postcard: PDF Presentation materials: PPT Streaming Video: Real Media How do small pelagic copepods manage to find mates in a large 3-dimensional world? Copepods are by far the most important zooplankters in the oceans and are the main food for pelagic fish and fish larvae. Their population dynamics and abundance are constrained by their capability to find sex-partners. By video-clips and animations the lecture will reveal the fascinating mate-finding and courtship behaviour of these mm-sized crustaceans. I will show how the females signal their presence and position to the males, and how the males optimize their search for females. Our understanding of the physical processes at the small scale helps us to interpret these behaviours. Insights in the details of mate-finding behaviour allow predictions of the abundances of copepods in the ocean, which are useful for fisheries biologists. Speaker: John Harte, Energy and Resources Group, University of California, Berkeley View postcard: PDF Presentation materials: PPT I examine the current status of knowledge about global warming and review prevailing myths that surround the subject, including the notion that the uncertainties in our current models provide equal support for the concerned and the complacent. One source of uncertainty stems from the fact that most current climate models do not describe ecological responses to warming, and thus they ignore feedback mechanisms that arise from the coupling of climate and ecosystems. From analysis of past climate change and from ongoing ecosystem-warming experiments and field observations, I argue that climate-ecosystem feedbacks are likely to bring about future warming that is considerably more intense than is currently projected.
View postcard: PDF Our world is composed by a multitude of diverse communities tightly linked by economic interests and various associated factors typically collected in the word, globalization.Mass and air transportation, immigration, and the integration of large heterogeneous economic communities (European Community, NAFTA, MercoSur, etc.) have dramatically altered the world. These "forces" have transformed the local and global, social and environmental landscapes where we live in today, and their impact is likely to grow. In this lecture, I will address some of the challenges that we face in this new world order, particularly when dealing with global health challenges and public health policy. I will illustrate some of these issues using recent and current experiences with tuberculosis, influenza, HIV, and drug use (alcohol and ecstasy). Jim Keener, Departments of Mathematics and Bioengineering, University of Utah View postcard: PDF Streaming Video: Real Media Heart attacks kill hundreds of people daily in the United States -
many more than are killed by math anxiety!
Streaming Video: Real Media Two relatively unexplored features characterize physiologic systems: 1) They are complex, non-linear and dynamic which results in emergent phenomena that can neither be predicted nor explained by examining their component parts in isolation; 2) they become highly ordered during fetal development and throughout the course of Darwinian evolution in apparent violation of the second law of thermodynamics. It follows that interconnections among the parts must play a role in emergent phenomena and the origin of order. How this is accomplished through the nature and number of interconnections has been explored by Kauffman(1). Explanation of increasing order in spite of the second law was achieved by Prigogine(2) who showed that order can spontaneously appear in systems close to thermodynamic equilibrium if they are made to dissipate energy which increases order by displacing them far from equilibrium and decreasing entropy production rate. The approaches of Kauffman and Prigogine have not been combined or reconciled and this needs to be done in order to have a more complete understanding of health and how it breaks down in disease. If energy dissipation in a system is too little or too much and/or if the nature or number of a system's interconnections is altered malfunction results. Although how this occurs is rather obscure, fluctuations in time and space are a common feature of complex systems. Many ways have been used to characterize these fluctuations but few have yet proven beneficial to medicine. Another common feature of complex systems is that, unlike many physical systems, the future can only be assessed by statistical probability. Physicians deal inadequately with uncertainty. Prognosis is part of the art of medicine and is the least scientific part of our profession. Yet the development of statistical mechanics to quantify probabilities in quantum mechanics has the potential of making prognosis more precise. Of the many ways to characterize fluctuations in complex systems, power laws are ubiquitous(3). They have powerful predictive properties; e.g., the Gutenberg Richter Law can predict the probability of an earthquake of any magnitude occurring over any region of the earth's surface over any given time interval with a high degree of certainty. Can power laws make prognosis quantitative? Although the future of physiology is uncertain, I predict our understanding of health will depend on uncovering the secrets of energy-dissipating, interconnected complex biological systems. Precise knowledge of how abnormal interconnections and energy dissipation leads to dysfunction is essential in the understanding of disease and should lead to more precise prognostication.1. S. Kauffman. The Origins of Order: Self-Organization and Selection in Evolution. New York: Oxford University Press, 1993. 2. I. Prigogine and I Stengers. Order Out of Chaos: Man's New Dialogue with Nature. New York: Bantm Books, 1984 3. P. Bak. How Nature Works: The Science of Self-Organized Criticality. New York: Springer-Verlag, 1996.
View postcard: PDF Presentation materials: PPT Streaming Video: Real Media Tissue engineering and related cell-based therapies promise to not only facilitate tissue repair but also functionally replace damaged and diseased tissues. With tissue engineering, the goal is to fabricate tissue constructs, comprised of cells in a supportive environment, which mimic the function and/or architecture of the target tissue. The source of cells used in these constructs is the subject of considerable scientific discussion (and, in the case of stem cells, public discussion). However, regardless of the source and types of the cells incorporated into these engineered constructs, there remains a significant challenge in providing sufficient nutrients to the cells during fabrication and following implantation. Any tissue implant greater in dimension than a few millimeters is too big for nutrients to efficiently diffuse to the construct's cells from outside the construct. This is why the first successfully engineered tissues have been thin, sheets of cells (e.g. a simple skin). As advances give rise to more complicated, 3-dimensional tissue designs, the need for a strategy to support the health of these constructs becomes more urgent. In the body, the cardiovascular system serves to effectively deliver nutrients to any tissue. Therefore, the ability to form and incorporate blood vessels (particularly microvessels) into the constructs is critically important for construct health and function. We will discuss the particular challenges related to providing proper nutrition to constructed tissues and the strategies being employed to build vessels and vessel networks in the laboratory.
View postcard: PDF Presentation materials: PPT Human immunodeficiency virus (HIV) causes AIDS but on a time scale that averages about 10 years. This suggested that HIV infection was a slow process and thus treatment could be delayed. I will show how using mathematical modeling to interpret changes in HIV level after drug therapy was initiated led to a revolution in thinking about HIV and formed the basis for combination therapy that has made HIV a treatable disease. During the lecture I will discuss the basic biology of HIV, show how mathematical analysis of clinical data uncovered many other features of HIV biology, give an update on HIV vaccines and other unsolved problems in this field, and lastly show how the lessons learned about HIV have been applied to improve the understanding and treatment of hepatitis C virus infection.
Walking is much easier to do than understand. After all, we could put a man on the moon before we had a good idea as to how he would move once he got there. Our understanding of walking has been limited not by effort or creativity but by the complexity of the problem. This complexity is a consequence of the tight interactions between the mechanics of muscles and limbs, the control of the brain and spinal cord, and the constraints of the physical environment. While sometimes frustrating, it is also what makes the study of locomotion physiology so fascinating and is responsible for walking's many unsolved mysteries. For example, why does amputee walking requires more energy than able-bodied walking? And, are their advantages of bipedalim over quadrupedalism? The goal of this talk is to provide insight into some of the general principles that underlie walking as well as the interesting techniques that have elucidated these principles. Many of these principles were originally identified, or have since been expanded upon, by the participants in the ongoing MBI Workshop titled "Biomechanics and Neural Control: Muscle, Limb and Brain".
View Flyer: PDF Integrative biology is providing inspiration to disciplines such as animatronics, animation, mathematics, medicine, robotics and space exploration. In return, these disciplines supply biologists with novel design hypotheses, algorithms and measurement devices. One example is in the area of BioMotion. Comparing the remarkable diversity in nature has lead to the discovery of general principles. Animals are amazing at legged locomotion because they have simple control systems, multifunction actuators and feet that allow no surface to be an obstacle. Extraordinarily diverse animals show the same dynamics - legged animals appear to bounce like people on pogo sticks. Force patterns produced by six-legged insects are the same as those produced by trotting eight-legged crabs, four-legged dogs and even running humans. Rapid running cockroaches can become bipedal as they take 50 steps in a single second and ghost crabs seem to glide with aerial phases. Yet, the advantage of many legs and a sprawled posture appears to be in stability. Mathematical models show that these designs self-stabilize to perturbations without the equivalent of a brain. Control algorithms appear embedded in the form of the animal itself. Muscles tune the system by acting as motors, springs, struts and shocks all in one. Amazing feet permit creatures such as geckos to climb up walls at over meter per second without using claws, glue or suction - just molecular forces. These fundamental principles of animal locomotion have inspired the design of creations in computer animation (A Bug's Life, Pixar), new control circuits, artificial muscles, self-clearing dry adhesives, and autonomous legged robots such as Ariel, Sprawl, Sitckybot and RHex will spawn the next generation of search-and-rescue robots.
The conscious volitional self in our brain perceives and interacts with the world through sensory, motor and cognitive systems that involve largely subconscious neural mechanisms. Experimental manipulations of these mechanisms reveal the brain's remarkable ability to adapt to changed conditions. The volitional self can also be extended through artificial devices, such as brain-machine interfaces, which exploit the brain's ability to incorporate prosthetic extensions. Accurate control of brainmachine interfaces depends on a combination of effective decoding algorithms and the brain's ability to adaptively modify its neural activity. Recently developed implantable recurrent brain-computer interfaces provide artificial feedback connections that the brain can learn to incorporate and that can also modify the brain's neural connections. This talk will explore these issues in light of current advances in neuroscience and neuroprosthetics.
Presentation materials: PDF View Flyer: PDF Although it is presently not precisely known what causes a person to become aggressive, violent, or psychotic, new neuroscientific evidence from functional brain imaging and genetics in schizophrenics and psychopathic killers hint at a rare convergence of genetic, epigenetic, and environmental factors occurring at specific windows of time. And there may be little room open for 'free will' to mitigate this tragic convergence of factors.
Presentation materials: PPT View Flyer: PDF Real democracy - when citizens meet in a face-to-face assembly and bind themselves under decisions they make themselves - has been practiced for some 2500 years by humans, but for more than 20 million years by honey bees. We will examine the remarkable democratic decision-making process of a honey bee swarm as it chooses a new home. We will see that bees have evolved sophisticated ways of working together to identify a dozen or more potential dwelling places, to choose the highest quality one for their new home site, and to make a decision without undue delay. We will conclude with some take-home lessons from the bees ("swarm smarts") on how to foster good decision making by democratic groups of humans. |
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