Fast and Strong Carbon Nanotube Yarn Artificial Muscles by Electro-osmotic Pump.

Previous electrochemically powered yarn muscles cannot be usefully operated between extreme negative and extreme positive potentials, since generated stresses during anion injection and cation injection partially cancel because they are in the same direction. We here report an ionomer-infiltrated hybrid carbon nanotube (CNT) yarn muscle that shows unipolar stress behavior in the sense that stress generation between extreme potentials is additive, resulting in an enhanced stress generation. Moreover, the stress generated by this muscle unexpectedly increases with the potential scan rate, which contradicts the fact that scan-rate-induced stress decreases for neat CNT muscles. It is revealed by the electro-osmotic pump effect that the effective ion size injected into the muscle increases with an increase in the scan rate. We demonstrate an electrochemically powered gel-elastomer-yarn muscle adhesive that generates and delivers muscle-contraction-mimicking stimulation to a target tissue.

Exposure to hypomagnetic field space for multiple generations causes amnesia in Drosophila melanogaster.

This is the introduction of Drosophila into the study of learning and memory affected by removal of the geomagnetic field (GMF) for successive generations. Using the operant visual learning/memory paradigm at a flight simulator, the present study revealed that wild-type flies raised in a hypomagnetic field environment continuously for 10 successive generations were gradually impaired in visual conditioning learning and memory formation and finally the 10th generation flies became morphs of nonlearners and completely amnesiac. The control experiments show that the impairment could not be ascribed to any apparent sensorimotor problems in Drosophila. The reverse shift from hypomagnetic field (HMF) to natural GMF restored the GMF-free induced amnesia fully after six consecutive generations. Thus, our findings demonstrate conclusively that some serious, but reversible learning and memory impairment may occur for living organisms in a prolonged separation from GMF over many consecutive generations. And Drosophila has the potential to develop into a new model organism for the study of the neurobiology of magnetism for multiple generations.

Control pattern of vocal center for vocalization in ruddy bunting (Emberiza rutila).

High vocal center (HVC) can produce single sound with one or two syllables by the single-type vocal control pattern in songbirds ruddy bunting (Emberiza rutila). It obviously shows left-side dominance in controlling double syllables, principal frequency (PF) and increasing sound intensity of the evoked calls. Meanwhile, the complex-type control pattern can produce complex calls with multisyllable, and also shows significant left-side dominance in controlling the number of syllables, tone changing and sound intensity. These indicate that left-side HVC controls higher frequency and complicated sentence structure. The basic vocal center, dorsomedial nucleus of the intercollicular complex (DM), controls the monosyllable sound in songbirds, and shows left-side dominance in controlling both the number of syllable and sound intensity. These results not only provide some direct evidence for left-side dominance in high vocal center, but also indicate that there is some internal connection between the high and basic vocal centers in songbirds.

Effects of hypomagnetic field on noradrenergic activities in the brainstem of golden hamster.

Previous studies found that elimination of the geomagnetic field (GMF) interferes with the normal brain functions, but the underlying mechanism remains unknown. The present study examined the effects of long-term exposures to a near-zero magnetic environment on the noradrenergic activities in the brainstem of golden hamsters. Both the content of norepinephrine (NE) and the density of NE-immunopositive neurons in the tissue decreased significantly after the treatment, and the effects could be progressive with time. These variations may substantially contribute to behavioral and mood disorders reported in other studies when animals are shielded from the GMF.