PMC

Combined effects of operational parameters of threshing drum on its performance. a Effect of concave clearance and feed rate on the threshing efficiency. b Effect of drum speed and feed rate on the threshing efficiency. c Effect of drum speed and concave clearance on the threshing efficiency. d Effect of concave clearance and feed rate on the pearling efficiency. e Effect of drum speed and feed rate on the pearling efficiency. f Effect of drum speed and concave clearance on the pearling efficiency. g Effect of concave clearance and feed rate on the grain damage. h Effect of drum speed and feed rate on the grain damage. i Effect of drum speed and concave clearance on the grain damage

(a) Stomatopods can rotate their eyes in all three degrees of freedom: yaw (red; side-to-side), pitch (blue; up-down) and torsion (green; rotation about the stalk). Photo credit: Mike Bok. (b) The rotating drum with the black and white grating on the inner face used to elicit yaw optokinesis. (c) Individual stomatopods are placed in the stationary aquarium with their body concealed within an artificial ‘burrow’ and their exposed eyes, located at the centre of the drum, are filmed using stereoscopic cameras from above. (d) Motion of the rotating drum (b,c) creates a field of view moving in the horizontal direction. (e) The torsional rotating drum. As for (a–c), the sides of the drum were covered with a black and white grating. (f) Individual stomatopods are placed in the stationary counterbalanced aquarium in the middle of the drum and filmed from above through slits in the drum. (g) The end of the drum (left in (d,e)), directly in front of the stomatopod, was filled with a radial pattern of black and white segments, which rotated torsionally at the same rate as the drum. (Online version in colour.)

Test results of dynamic balance of drum, (a) Change curve of drum bearing reaction force resultant force, (b) Result of drum dynamic balance counterweight

Changes in cerebellar volume increase after drumming. On the left, the increased cerebellar volume is shown in green (left VIIIa), and decreased volume in red (vermis Crus I, left and right VIIIb). On the right, the percentage increase of the vermis Crus I, left VIIIa and VIIIb corrected for total cerebellar volume with standard error bars for the drum and control group are shown (vermis Crus I: drum = −7.4%, control=9.5%; left VIIIa: drum = 0.65%, control = −0.42%; averaged VIIIb: drum = −0.42%, control = −0.03%).