Physiology

Plant PhysiologyAutonomous locomotion and Nastic movements

One area of interest in physiology is to understand autonomous movement and its regulation. Movement requires force production, and its spatiotemporal coordination and control in light of sensory feedback from the environment. The questions any study of coordinated movement raises thus impinge on molecular, cellular and tissue dynamics and neuroscience, and from a mathematical perspective involves ideas from continuum dynamics, control theory, optimization etc. and link to questions in sensory physiology, behavior, ecology etc.

A particular interest is that of locomotion physiology that links systems neuroscience to morphology, mechanics, control and learning. Animals move in diverse manners, and we have studied many of these locomotory gaits – walking, crawling, swimming, slithering, etc. from a theoretical and experimental perspective to understand the neurodynamics of locomotion, as well as their ecodynamics, created theories for the different gaits of long slender animals such as crawling snails, and worms, undulating snakes, flexing fishes etc. and showed that tuning a single parameter suffices to explain the gait transitions from crawling to undulation to inch-worming,  explaining how they respond to stimuli in the context of simple behavioral strategies such as thermotaxis etc.

We have shown how one can derive general scaling principles underlying macroscopic aquatic locomotion  which capture the essence of locomotion from shrimps to whales, again showing how physical constraints lead to evolutionary convergence, with lessons for robotic swimmers,  the evolution of locomotion using robot-like objects, gaits and gait transitions in slender organisms such as snakes, and simple aspects of learning and coordination in primitive organisms.

Animals are not the only living systems capable of autonomous movement. Plants can also move only by growing, except for the odd carnivorous plant, and so respond to environmental changes by very different strategies relative to those deployed by animals. These adaptations and exaptations raise a host of physical and physico-chemical questions that beg for a quantitative treatment from both an experimental and a theoretical perspective. The diversity of plant and fungal life on our planet raises questions from the range of leaf and flower shapes to the ability to silently haul water to the top of a giant Sequoia, the myriad mechanisms for seed and spore dispersal, carnivory and rapid movements, etc.  at the interface of biology and physics.  Our occasional studies in this area have focused on aspects of hydraulically-driven movements in plants and fungi, the morphometry and morphogenesis of shoots, leaves and flowers, the design principles underlying transpiration, and proprioceptive feedback in growth. We are also interested using plant physiology as an inspiration for engineered devices.

Pathophysiology

The breakdown of physiology is manifest in a range of disorders and diseases. More than a decade ago, inspired by the early work of Pauling et al. on hemoglobinopathies, we explored the vaso-occlusive dynamics of sickle cell disease in microfluidic devices experimentally and showed that we can capture the phase space of jamming in terms of a set of geometric, physical and biological parameters. This allowed us to construct a theoretical framework for how a single red blood cell gets stuck in a tapering channel, and how the collective dynamics of jamming occurs in pressure-driven flows of soft suspensions of these cells, capturing the dynamics of a vaso-occlusive event. We have recently returned to the question to study how we might create cheap diagnostics for the progression of the disease and deploy these in resource-poor environments.

Related Publications

How the Venus Flytrap snaps Y. Forterre, J. Skotheim, J. Dumais and L. Mahadevan,  Nature,  433, 421-25, 2005. [View PDF] [Download PDF]
Physical limits and design principles for plant and fungal movements J. Skotheim and L. Mahadevan,  Science,  308, 1308-10, 2005. [View PDF] [Download PDF]
Optimal vein density in artificial and real leaves X. Noblin, L. Mahadevan, I. Coomaraswamy, D. Weitz, N. Holbrook and M. Zwieniecki,  Proceedings of the National Academy of Sciences (USA),  105, 9140, 2008. [View PDF] [Download PDF]
On the growth and form of shoots R. Chelakkot and L. Mahadevan,  Journal of the Royal Society Interface , 14, 20170001, 2017. [View PDF] [Download PDF]
Botanical ratchets I. Kulic, M. Mani, H. Mohrbach, R. Thaokar, L. Mahadevan,  Proceedings of the Royal Society of London (B), Biological Sciences , 276, 2243-47, 2009. [View PDF] [Download PDF]
Biomimetic ratcheting motion of lubricated hydrogel filaments, Mahadevan, L., S. Daniel and M. Chaudhury,  Proceedings of the National Academy of Sciences (USA) , 101, 23-26, 2004. [View PDF] [Download PDF]
Limbless undulatory propulsion on land Z. Guo and L. Mahadevan,  Proceedings of the National Academy of Sciences (USA),  105, 3179, 2008. [View PDF] [Download PDF]
Scaling macroscopic aquatic locomotion M. Gazzola, M. Argentina and L. Mahadevan,  Nature Physics , 10, 758-61, 2014. [ONLINE ARTICLE] [View PDF] [Download PDF]
Gait and speed selection in slender inertial swimmers M. Gazzolaa, M. Argentina and L. Mahadevan,  Proceedings of the National Academy of Sciences  112, 13, 2015. [View PDF] [Download PDF]
Elastohydrodynamic scaling law for heart rates. E. Virot, V. Spandan, L. Niu, W. M. van Rees, and L. Mahadevan, Phys. Rev. Lett.,  125, 058102, 2020. [DOI] [View PDF] [Download PDF]
A proprioceptive neuromechanical theory of crawling P. Paoletti and L. Mahadevan,  Proceedings of the Royal Society (B) , 281, 20141092, 2014. [View PDF] [Download PDF]
Integrative neuromechanics of crawling in D. melanogaster larvae C. Pehlevan, P. Paoletti, L Mahadevan  eLife,  5:e11031,  2016. [View PDF] [Download PDF]
Coordinated crawling via reinforcement learning. S. Mishra, W. van Rees, L. MahadevanRoyal Society-Interface, 17: 20200198,  2020. [DOI] [View PDF] [Download PDF]
How ticks get under your skin: insertion mechanics of the feeding apparatus of Ixodes ricinus ticks D. Richter, F-R. Matuschka, A. Spielman, and L. Mahadevan  Proceedings of the Royal Society B,  280, 20131758, 2013. [View PDF] [Download PDF]
Controlled gliding and perching through deep-reinforcement-learning. G.Novati, L. Mahadevan, and P. Koumoutsakos, Physical Review Fluids 4, 093902, 2019. [View PDF] [Download PDF]
Planar controlled gliding, tumbling and descent.
P. Paoletti and L. Mahadevan,  Journal of Fluid Mechanics,  698, 489-516, 2011.  [View PDF] [Download PDF]
Neuromimetic Circuits with Synaptic Devices Based on Strongly Correlated Electron Systems Sieu D. Ha, Jian Shi, Yasmine Meroz, L. Mahadevan, and Shriram Ramanathan,  Physical Review Applied 2 , 064003, 2014. [DOI] [View PDF] [Download PDF]
Controllable biomimetic birdsong A. Mukherjee, S. Mandre and L. Mahadevan,  Journal Royal Society Interface  14: 20170002, 2017. [View PDF] [Download PDF]
Mechanosensation and mechanical loads modulate the locomotory gait of swimming C. elegans J. Korta, D. Clark, C. Gabel, L. Mahadevan, and A. Samuel,  Journal of Experimental Biology , 210, 2383, 2007. [View PDF] [Download PDF]
Recovery of locomotion after injury in Drosophila melanogaster depends on proprioception A. Isakov, S. M. Buchanan, B. Sullivan, A. Ramachandran, J. K. S. Chapman, E. S. Lu, L. Mahadevan, and B. de Bivort  Journal of Experimental Biology,  219, 1760-1771, 2016. [View PDF] [Download PDF]
Sickle cell vaso-occlusion and rescue in a microfluidic device J. Higgins, D. Eddington, S. Bhatia and L. Mahadevan,  Proceedings of the National Academy of Sciences (USA) , 104, 20496, 2007. [View PDF] [Download PDF]
Statistical dynamics of flowing red blood cells by morphological image processing J. Higgins, D. Eddington, S. Bhatia and L. Mahadevan,  PLoS Computational Biology , 5, e1000288, 2009. [View PDF] [Download PDF]
A biophysical indicator of vaso-occlusive risk in sickle cell disease D.K. Wood, A. Soriano, L. Mahadevan, J.M. Higgins, S.N. Bhatia,  Science Translational Medicin e, 4:123, 123ra26, 2012. [View PDF] [Download PDF]
Pressure-driven occlusive flow of a confined red blood cell T. Savin, M. M. Bandi and L. Mahadevan,  Soft Matter , 12, 562-573, 2015. [View PDF] [Download PDF]
Hydrodynamics of hemostasis in sickle-cell disease S.I.A. Cohen and L. Mahadevan,  Physical Review Letters 110, 138104, 2013. [View PDF] [Download PDF]
Self-organized biotectonics of termite nests. A. Heyde, L. Guo, C. Jost, G. Theraulaz and L. Mahadevan, Proceedings of the National Academy of Sciences, , 2021. [ONLINE ARTICLE] [DOI] [View PDF] [Download PDF]