ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Hosain Bagheri is an author on ‘ Detecting subtle subterranean movement via laser speckle imaging’, published in JEB. Hosain conducted the research described in this article at Georgia Tech, USA under the supervision of Dr Goldman and Dr Goodisman. Hosain is now a Postdoctoral Research Fellow in the lab of Daniel I. Goldman at Georgia Tech, investigating biological organisms through engineering and physics to deepen our understanding of biology and develop real-world applications for societal benefit.
Hosain Bagheri
How did you become interested in biology?
As a child, I eagerly read monthly issues of the Popular Science magazines, which sparked my realization that my interests in engineering, science and biology could coexist. During my undergraduate and master's studies, I focused on mechanical engineering with a minor in biomedical engineering, driven by a desire to understand how the body ‘works’ and to seek solutions for humanity. As a PhD student, I gained valuable experience in animal testing from an engineering perspective, deepening my appreciation for the innovative solutions that biological organisms offer.
Describe your scientific journey and your current research focus
My first exposure to animal experimentation was working with a lab dog as an undergraduate, where I measured cartilage wear using implanted strain gauges. As a PhD student, I explored the locomotion of basilisk lizards on dry and saturated sand and water, examining how body velocity and pitch change with different substrates. I then shifted to studying octopuses, investigating the control mechanisms of sucker attachment and detachment in relation to the central nervous system. I further examined octopus arm movement using EMG to analyze the activity of longitudinal and transverse muscles in their hydrostatic structure during bending, elongation, and shortening.
How would you explain the main findings/message of your paper to a member of the public?
Many organisms live underground, but observing their behavior is challenging due to the opaque substrates they inhabit. We used laser speckle imaging to non-invasively monitor fire ants at various developmental stages, burial depths and moisture levels. Our findings revealed that more developed ants exhibited increased activity, while deeper burial depth and wetter conditions reduced movement and/or detection. This straightforward non-invasive method enables the quantification of biological activity in substrate, which can enhance our understanding of underground organism behavior in both laboratory and field settings.
Laser speckle imaging can be used to non-invasively monitor fire ants at various developmental stages, burial depths and moisture levels.
Why did you choose JEB to publish your paper?
We chose JEB because it is well suited for publishing research focused on animal experiments and the insights that can be drawn from them. Importantly, while this technique has been applied in soft matter contexts (e.g. foams, colloidal systems and granular dynamics) and medical settings (e.g. retinal blood flow, skin capillary perfusion and cerebral blood flow), it remains untested for monitoring organisms within substrates. We aim to share this method with others as an alternative means for exploring underground organism activity and behavior.
What is the most important piece of equipment for your research, what does it do and what question did it help you address?
The most important equipment for our research was the laser and camera. The laser focuses a coherent, collimated light onto the medium, while the camera captures the speckle pattern from backscattered light, which precludes direct imaging of animal kinematics. Changes in the speckle pattern arise from phase shifts in light paths caused by multiple scattering events. This technique can resolve nanometer-scale deformations in a medium by analysing the temporal evolution of pixel intensity within the dynamic speckle pattern. More importantly, while a high-end laser and camera confirmed the proof of concept, the method remains effective while being accessible, allowing users to achieve similar results with low-cost, off-the-shelf components.
What is your favourite animal, and why?
My favorite animal is the octopus. Octopuses are made of soft tissue, except for their beak, and have eight arms. Octopus arms are muscular hydrostats, achieving movement through volume conservation, yet they can exert impressive forces. They feature a complex nervous system with a central brain and nerve cords in each arm, allowing for precise movement. Their suckers, controlled by various muscles, provide motor functions and allow sensory exploration of the environment. Therefore, it serves as an exemplary model for designing soft robots due to its powerful, agile arms and precise suckers. Understanding the sensing, actuation and control mechanisms of octopus arms and suckers will greatly aid in developing distributed control for soft robotic arms.
Hosain Bagheri’s contact details: School of Physics, Georgia Tech, 837 State Street NW, Atlanta, GA 30332, USA.
E-mail: [email protected]
