8th July, 2014
Job advertisement - closed
Postdoctoral Research Assistant – The mechanics of the insect wing hinge

We are seeking a full-time Postdoctoral Research Assistant to join the Oxford Animal Flight Group (http://flight.zoo.ox.ac.uk). The post is funded by the Engineering and Physical Sciences Research Council and is fixed-term for 2.5 years, starting as soon as possible. This project aims to develop computational and mechanical models of the insect wing hinge. This research builds on the recent advances in time-resolved high-speed synchrotron tomographic imaging, which makes it now possible to visualize the inner workings of an insect during flight (Walker et al., 2014; see below for examples of media coverage).

The insect wing hinge forms the most complex joint found in nature. Such is the difficulty in understanding its mechanics that there is currently no consensus on how the wing even moves back and forth. The postdoctoral researcher will analyse microtomography data of flying insects and develop computational and mechanical models that replicate the movement of the insect wing hinge mechanism.

You should possess, or be very close to possessing, a PhD/DPhil in a relevant subject, and should have a background in modelling mechanical systems. You should also have an interest in biomechanics, be able to work well in a team, and have strong evidence of research achievement to date. 

Examples of media coverage of in-vivo time-resolved microtomography:  BBC News, New Scientist, Reuters UK, National Geographic

Informal enquiries may be made to Simon Walker (simon.walker@zoo.ox.ac.uk)

Further details can be found here: http://www.jobs.ac.uk/job search: “114007”

25th March, 2014
New Publication
X-rays film inside live flying insects – in 3D
 
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Scientists have used a particle accelerator to obtain high-speed 3D X-ray visualizations of the flight muscles of flies. The team from Oxford University, Imperial College, and the Paul Scherrer Institute (PSI) developed a groundbreaking new CT scanning technique at the PSI’s Swiss Light Source to allow them to film inside live flying insects. Their article, including 3D movies of the blowfly flight motor, is published March 25 in the open access journal PLOS Biology. The movies offer a glimpse into the inner workings of one of nature’s most complex mechanisms, showing that structural deformations are the key to understanding how a fly controls its wingbeat.

In the time that it takes a human to blink, a blowfly can beat its wings 50 times, controlling each wingbeat using numerous tiny steering muscles – some as thin as a human hair. The membranous wings contain no muscles, so all of the flight muscles are hidden out of sight within the thorax. “The thoracic tissues block visible light, but can be penetrated by X-rays”, says Dr. Rajmund Mokso from PSI. “By spinning the flies around in the dedicated fast-imaging experimental setup at the Swiss Light Source, we recorded radiographs at such a high speed that the flight muscles could be viewed from multiple angles at all phases of the wingbeat. We combined these images into 3D visualizations of the flight muscles as they oscillated back and forth 150 times per second.”

The flies responded to being spun around by trying to turn in the opposite direction, allowing the scientists to record the asymmetric muscle movements associated with turning flight. “The steering muscles make up less than 3% of a fly’s total flight muscle mass”, says Prof. Graham Taylor who led the study in Oxford, “so a key question has been how the steering muscles can modulate the output of the much larger power muscles. The power muscles operate symmetrically, but by shifting each wing’s mechanism between different modes of oscillation, the fly can divert power into a steering muscle specialized to absorb mechanical energy – rather like using the gears of a car for braking.”

The scientists hope to use their results to inform the design of new micromechanical devices. “Flies have solved a problem faced by engineers working on the same scale” says Prof. Taylor: “How to produce large, complex, three-dimensional motions, using actuators that only generate small, simple, one-dimensional ones?” The clever design of the blowfly flight motor solves that problem admirably, as the results of this study show. Dr. Simon Walker from Oxford, who was joint first author of the study with Daniel Schwyn, adds: “The fly’s wing hinge is probably the most complex joint in nature, and is the product of more than 300 million years of evolutionary refinement. The result is a mechanism that differs dramatically from conventional manmade designs; built to bend and flex rather than to run like clockwork.”

The full article can be read here:
http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001823

13th February, 2014
New Book
Evolutionary Biomechanics, Selection, Phylogeny, and Constraints

Graham Taylor and Adrian Thomas
 
Evolutionary biomechanics is the study of evolution through the analysis of biomechanical systems. Its unique advantage is the precision with which physical constraints and performance can be predicted from first principles. Instead of reviewing the entire breadth of the biomechanical literature, a few key examples are explored in depth as vehicles for discussing fundamental concepts, analytical techniques, and evolutionary theory. Each chapter develops a conceptual theme, developing the underlying theory and techniques required for analyses in evolutionary biomechanics. Examples from terrestrial biomechanics, metabolic scaling, and bird flight are used to analyse how physics constrains the design space that natural selection is free to explore, and how adaptive evolution finds solutions to the trade-offs between multiple complex conflicting performance objectives.