Final Program

International Symposium on the
Mechanics of Plants, Animals
and Their Environments:
Integrative Perspectives

January 11 - 16, 1998
The Radisson Santa Barbara Hotel
Santa Barbara, California


Joseph A.C. Humphrey
Bucknell University
Lewisburg, Pennsylvania, USA


Friedrich Barth
University of Vienna

Julian Vincent
The University of Reading

Timothy Secomb
University of Arizona

Engineering Foundation
345 East 47th Street, Suite 303
New York, N.Y. 10017
T: 1-212-705-7836 - F: 1-212-705-7441

Biological and Environmental Mechanics Web Page
Forward to the Conference

Sunday, January 11, 1998

15:00 - 18:30 Registration

Chair: J. Humphrey

Plenary Lecture:
The Flexibility of Organisms and the Forces of Flow
S. Vogel, Duke University

20:00 - 21:30 Dinner

21:30 - 22:00 Reception

Monday, January 12, 1998

07:00 - 08:15 Breakfast


8:15 - 11:45 Session 1: Fluid- and Thermo-Mechanics
Session Chairs: M. Canny and D. Tomos

08:15 - 09:00 Keynote:
Breaking the Bonds of the Cohesion Theory: A Rational Theory of Plant Water Transport
M. Canny, Carleton University

09:00 - 09:15 Discussion of Keynote Paper

09:15 - 09:45 The Cohesion Theory of Plant Water Transport
J. Sperry, Duke University

09:45 - 10:15 Coffee Break

10:15 - 10:45 Ice Nucleation, Deep Supercooling, and Glass Formation in Plants: The Thermomechanics of Freezing in Plants
M. Wisniewski, USDA-ARS

10:45 - 11:15 Sex and Fluids: The Evolutionary Ecology of Abiotic Pollination
J. Ackerman, University of Northern British Columbia

11:15 - 11:45 Plants as High Pressure Hydraulic Machines: The Role of the Cell Wall in Determining Cell Turgor Pressure
D. Tomos, H, Arif, J. Palta, A. Santa Cruz, and R. Lawrence, University of Wales

12:15 - 13:30 Lunch



16:30 - 19:30 Session 2: Solid-Mechanics and Dynamics
Session Chairs: T. Speck and J. Vincent

16:30 - 17:15 Keynote:
Plant Biomechanics - Goals and Applications
C. Spatz, Albert-Ludwigs-University

17:15 - 17:30 Discussion of Keynote Paper

17:30 - 18:00 Plant Cell Walls Could Provide Future Inspiration for the Design of Smart Composite Materials
D. Hepworth, University of Reading

18:00 - 18:30 The Mechanics and Dynamics of Tendril Perversion in Climbing Plants
A. Goriely and M. Tabor, University of Arizona

18:30 - 19:00 The Relationship Between Stelar Geometry and Mechanical Integrity in Plant Stems
K. Schulgasser and A. Witztum, Ben-Gurion University of the Negev

19:00 - 19:30 Selecting the Right Material for the Plant Structure
J. Vincent, University of Reading and
T. Speck, Albert-Ludwigs-University

19:30 - 20:00 Social Hour

20:00 - 21:30 Dinner

21:30 - 22:00 Social Hour - Informal discussions and continued poster viewing

Tuesday, January 13, 1998

07:00 - 08:15 Breakfast


08:15 - 11:45 Session 3: Fluid- and Thermo-Mechanics
Session Chairs: S. Vogel and J. Rayner

08-15 - 09:00 Keynote:
When Does Morphology Matter? -- Some Biofluiddynamical Examples
M. Koehl, University of California at Berkeley

09:00 - 09:15 Discussion of Keynote Paper

09:15 - 09:45 Visualization and Modelling of the Wakes of Flying Birds
J. Rayner, University of Bristol

09:45 - 10:15 Coffee Break

10:15 - 10:45 The Use of the Womersley Number to Characterize the Unsteady Nature of Internal Flow
C. Loudon, University of Kansas and
A. Tordesillas, University of Melbourne

10:45 - 11:15 Constructal Theory of Shape and Structure Formation in Natural Systems with Internal Flows
A. Bejan, Duke University

11:15 - 11:45 Modeling Fish Locomotion Using Elastic Plate Theory
R. Root, Lafayette College

12:15 - 13:30 Lunch



16:30 - 19:30 Session 4: Solid-Mechanics and Dynamics
Session Chairs: F. Barth and R. Full

16:30 - 17:15 Keynote:
How Nature Engineers Ears
A. Michelsen, Odense University

17:15 - 17:30 Discussion of Keynote Paper

17:30 - 18:00 Mechanical Design of Wind-Receptor Hairs of Cricket
T. Shimozawa, Hokkaido University

18:00 - 18:30 Forest Fire Detection in a Beetle Employing a New Type of Infrared Receptor
H. Schmitz, University of Bonn

18:30 - 19:00 Inspiration from Insects in the Design of Legged Robots
R. Full, University of California at Berkeley

19:00 - 19:30 Balancing Stability and Maneuverability: The Organization of the Flight Control System of Flies
M. Dickinson, University of California at Berkeley

19:30 - Dinner on your own
(List of Santa Barbara area Restaurants will be supplied)

Wednesday, January 14, 1998

07:00 - 08:15 Breakfast


08:15 - 11:45 Session 5: Mechanics of Cells in Fluid Environments
Session Chairs: T. Secomb and D. Hammer

08:15 - 09:00 Keynote:
The Chemistry and Mechanics of Leukocyte Adhesion Under Flow
D. Hammer, University of Pennsylvania

09:00 - 09:15 Discussion of Keynote Paper

09:15 - 09:45 Intermolecular and Long-Range Interactions Between Biomolecules and Surfaces
J. Wong, Boston University

09:45 - 10:15 Coffee Break

10:15 - 10:45 Computational Modeling of the Fluid Dynamics of Motile Microbes
L. Fauci, Tulane University

10:45 - 11:15 Cell Membrane Mechanics: Large Deformation of a Structured Material
D. Discher, University of Pennsylvania

11:15 - 11:45 Mechanics of Red Blood Cell Motion in Capillaries
T. Secomb, University of Arizona

12:15 - 13:30 Lunch



16:30 - 19:30 Session 6: Mechanics of Cells: Motility, Contraction and Growth
Session Chairs: J. Bereiter-Hahn and T. Secomb

16:30 - 17:15 Keynote:
Forces Contributing to Cell Locomotion and Tissue Development
E. Elson, P. Jay, M. Kolodney and C. Pasternak, Washington University School of Medicine

17:15 - 17:30 Discussion of Keynote paper

17:30 - 18:00 Dynamics of Cellular Mechanics: Investigations with the Acoustic Microscope
J. Bereiter-Hahn, Goethe-Universität

18:00 - 18:30 Traction Forces Generated by Locomoting and Dividing Cells
K. Burton, Carnegie-Mellon University

18:30 - 19:00 Molecular Biology and Mechanics of Nematocyst Discharge
T. Holstein, University of Frankfurt

19:00 - 19:30 The Self-Assembly of Bacterial Macrofibers
N. Mendelson, University of Arizona

19:30 - 20:00 Social Hour

20:00 - 21:30 Dinner

21:30 - 22:00 Social Hour - informal discussions and continued poster viewing

Thursday, January 15, 1998

07:00 - 08:15 Breakfast


08:15 - 11:45 Session 7: Fluid-, Thermo-, Solid-Mechanics and Dynamics
Session Chairs: J. Koseff and J. Humphrey

08:15 - 09:00 Keynote:
Predicting Physical Disturbance in a Variable Environment
M. Denny, Stanford University

09:00 - 09:15 Discussion of Keynote Paper

09:15 - 09:45 Wheat Exhibits an Anisotropic Response to a Wind Gust
T. Farquhar, University of Maryland

09:45 - 10:15 Coffee Break

10:15 - 10:45 The Influence of Thallus Morphology on the Productivity and Persistence of an Intertidal Macroalga
E. Bell, University of Rhode Island

10:45 - 11:15 Toward an Understanding of Grass / Tree Interactions: Alteration of the Thermal Microclimate by Grass Inhibits Growth of Tree Seedlings in Frosty Climates
M. Ball, Australian National University

11:15 - 11:45 Ecophysiologically Important Flows in and Around Plants: Computer Based Studies
A. Roth, Tübingen University

12:15 - 13:30 Lunch

13:30 - 15:00 Session 8: Fluid-, Thermo-, Solid-Mechanics and Dynamics
Session Chairs: E. Bell and M. Denny

13:30 - 14:00 Taking Biomechanics to the Field: Pattern and Process in Wave Swept Plant Communities
C. Blanchette, University of California at Santa Barbara

14:00 - 14:30 How Butterflies Optimize Solar Energy Absorption and Convective Heat Transport by Wing Design
P. Wong, I. Miaoulis and L. Trefethen, Tufts University

14:30 - 15:00 Vibration-Mediated Interactions in an Insect Prey-Predator System: Leaves as Transmission Channel
J. Casas, Université de Tours

15:00 - 15:30 Break

15:30 - 18:30 Visit to the Botanical Gardens of the Ganna Walska Lotusland in Montecito

19:00 - 19:30 Reception

19:30 - 21:00 Dinner

21:00 - 22:00 What to do in The Future?

Friday, January 16, 1998

07:00 - 08:15 Breakfast

08:15 - 10:45 Session 9: Fluid- and Thermo-Mechanics
Session Chairs: A. Bejan and M. LaBarbera

08:15 - 08:45 The Physics of Chemoreception: Understanding the Physical Processes that Determine the Information in Chemical Signals
P. Moore, Bowling Green State University

08:45 - 09:15 A Dragonfly Wing From an Engineers Point of View: Some Statical and Aerodynamical Aspects of an Ultralight Airfoil
A. Kesel, University of Saarland

09:15 - 09:45 Coffee Break

09:45 - 10:15 Mechanisms of Thermoregulation in Hovering Insects
S. Roberts, Arizona State University

10:15 - 10:45 Characterization of Vascular Pathologies by Fractal Analysis
J. Baish, Bucknell University, Y. Gazit, R. Jain, and L. Hamberg, Massachusetts General Hospital

10:45 - 11:45 Session Summaries and Prognosis for Future Meetings
Panel: F. Barth, J. Humphrey, T. Secomb, J. Vincent

11:45 - 12:00 Symposium Closure

12:15 - 13:30 Lunch

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Biologists, engineers and physical scientists (chemists, physicists and mathematicians) generally attend meetings specialized to their respective professions. They rarely have the opportunity to meet collectively and in a mutually inclusive environment in order to share knowledge, research methodologies, practical experience and, very importantly, differences in problem-solving approaches and goals. Primarily for this reason, we conceived and organized the First International Symposium on the Mechanics of Plants, Animals and Their Environments (MPATHE): Integrative Perspectives, held January 11-16, 1998 at the Radisson Hotel in Santa Barbara, California, under the auspices of the Engineering Foundation.

The purpose of the Symposium has been to bring together a highly interdisciplinary mix of persons, to present and discuss mechanical and thermal phenomena related to plants, animals and their environments. The length scale range of interest spans from single cells, to entire organisms, to their host environments, implying length scale ratios exceeding 1012 and including the extremes of micro (molecular) and macro (atmospheric/oceanographic) forces.

Such disparate phenomena as the breaking of a limb from a tree, the lifting of a load by an ant, the sensing of vibrations by a spider, the dispersion of seeds or chemical pollutants by the wind, the flight of birds and insects, the swimming of fish, the transport of oxygen via blood cells, the rising of sap in trees, the hot chemical discharge from the bombardier beetle, the solar radiation interception by a butterfly's wings, the dispersal and sensing of pheromone plumes in moths, the locomotion of water striders on water surfaces, filter feeding in marine animals, insect sound production, the mechanics of single cells and their membranes and skeletons, the physico-chemical properties of arthropod exoskeletons, the mechanics of blood flow through large blood vessels and in capillaries, the optima of certain organismal forms in relation to function . . . are all described by a common set of physical laws. While these laws provide a way for physical scientists and engineers to analyze diverse biological phenomena and establish underlying commonalities among them, it is equally important to attain a better sense for the importance of variation and diversity in nature. For biologists it is a main concern that the physical scientists and engineers should appreciate this variation and look to the diversity offered by nature as to a treasure chest, one which can be opened for them by the proper biologists.

Therefore, an underlying objective of the Symposium has been to identify integrative commonalities, as well as diversity, in the fundamentals and applications of fluid-mechanics, solid-mechanics and thermo-mechanics among plants, animals and their environments. The application of ideas derived from living organisms should not be missed since their analysis serves to reveal the more common, hence more successful, mechanisms, materials and structures for possible novel engineering applications. This impinges on "smart" technology, where some of the ideas may be presaged by nature.

While, in practice, nature rarely offers truly "ready made" solutions for engineering problems, it provides a potentially extremely valuable richness of stimulating ideas. Furthermore, in nature, the solutions found for a problem as a rule must allow for many different demands, some of which are atypical of engineering.

Because of its highly interdisciplinary subject, and because of its scientific-political timeliness, we believe the Symposium has the potential for becoming an internationally recognized biennial event. To our knowledge, there are few venues in existence today for the presentation and discussion of the applications of science and engineering to plants, animals and their environments in the logically integrative manner proposed here. (A notable comparable effort has been undertaken by Werner Nachtigall in Germany.) Among the strengths of the present Symposium is the notion of bringing together in a common intellectual setting a variety of individuals concerned with highly inter-disciplinary problems, but who generally attend meetings of much more narrow focus, specific to their subject areas.

In the words of our colleague and plenary speaker, Steve Vogel, "Perhaps one might stress the peculiar communicative problems that a symposium such as this can address; one for which person-to-person contact is especially valuable. Mechanics may be equally important in engineering and biology, but we are amalgamating two very different traditions, with the divergence going back at least to the Renaissance. The engineering world is fundamentally synthetic; it deals mostly with Newtonian fluids in turbulent flows and fairly stiff, isotropic solids; it can fabricate specimens for testing; it is comfortable with mathematical modeling and complex quantitative analyses. The biological world is basically analytic; its fluids are commonly non-Newtonian or flow laminarly; its solids are rarely isotropic and may lose important characteristics when reshaped for testing; it is less experienced with modeling and quantitative analyses, but it does deal comfortably with the peculiar concomitants of evolution by natural selection. Faced with some new variable, the engineer borrows a common word, redefines it with admirable specificity, and thus baffles the non-initiate. Faced with something equally novel, the biologist concocts a label from some miscegenated classical roots that scares off the outsider." Clearly, much good can be achieved by facilitating communication between the two!

With advances in micromachining (in polymers and other elastomeric materials as well as silicon) and biotechnology (including the automated and controlled movement, mixing, reaction, synthesis and analysis of nanoliter and microliter fluid quantities), the distinctions between the natural and engineered worlds become increasingly blurred. Major research programs currently underway are aimed at building engineered systems of micro- and nano-dimensions that are characterized by the challenge of mixing in laminar flow and non-Newtonian fluid transport. Non-invasive testing, flow visualization, and flow modeling are all key challenges. This merging of what we once thought of as separate domains, the engineered and the biological, is precisely what the Symposium seeks to explore and encourage.

Aside from its varied and high quality technical content, the Symposium is politically timely for the social awareness it can engender towards plants, animals and their environments. Global industrialization advances at a relentless pace but, through the education of society, it need not destroy the planet we inhabit. Increasing the understanding and awareness of the general public and, especially, of national and international corporations as well as governments concerning the physical aspects of the interactions between organisms (including humans) and their environments will go a long way towards addressing this problem. It is part of the mission of the Symposium to call attention to this need explicitly, through the publication of a volume containing the Symposium abstracts and via the subsequent publication of selected Symposium papers in the archive journals.

The First International MPATHE Symposium would not have been possible without the generous support provided by the National Science Foundation and the Engineering Foundation. Funds from these agencies were used to provide travel and registration awards to over forty Symposium participants making presentations. Several individuals contributed to the planning and execution of the Symposium and we especially thank Barbara Hickernell, Rosa Landinez and Frank Schmidt at the Engineering Foundation, as well as Lois Engle and Judy Ranck at Bucknell. We gratefully acknowledge the invaluable assistance provided by the Symposium Organizers and Session Chairs who worked diligently to create an international program of unusual technical content. (The names of these persons are listed in the Symposium volume.) Finally, we express our sincere thanks to Ann Dewey of Ganna Walska Lotusland for facilitating a most memorable visit to that beautiful botanical garden!

Joseph Humphrey
Friedrich Barth
Timothy Secomb
Julian Vincent

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