Why it is important to build robots capable of doing science

Science, like any other cognitive activity, is grounded in the sensorimotor interaction of our bodies with the environment. Human embodiment thus constrains the class of scientific concepts and theories which are accessible to us. The paper explores the possibility of doing science with artificial cognitive agents, in the framework of an interactivist-constructivist cognitive model of science. Intelligent robots, by virtue of having different sensorimotor capabilities, may overcome the fundamental limitations of human science and provide important technological innovations. Mathematics and nanophysics are prime candidates for being studied by artificial scientists

Ligand binding mechanisms in human cone visual pigments

Vertebrate vision starts with light absorption by visual pigments in rod and cone photoreceptor cells of the retina. Rhodopsin, in rod cells, responds to dim light, whereas three types of cone opsins (red, green, and blue) function under bright light and mediate color vision. Cone opsins regenerate with retinal much faster than rhodopsin, but the molecular mechanism of regeneration is still unclear. Recent advances in the area pinpoint transient intermediate opsin conformations, and a possible secondary retinal-binding site, as determinant factors for regeneration. In this Review, we compile previous and recent findings to discuss possible mechanisms of ligand entry in cone opsins, involving a secondary binding site, which may have relevant functional and evolutionary implicationsPeer ReviewedPostprint (author's final draft

The Eye of the Larval Firefly \u3ci\u3ePhoturis\u3c/i\u3e: A Structural and Functional Description

Fireflies are bioluminescent beetles and members of the holometabolous clade. As holometabola, fireflies interact with their environment during two stages: larva and adult. I studied firefly stemmata, Photuris genus, with the aim of understanding their ecological utility by identifying structural and functional features of the eye. As a first step toward this goal, I used microscopy to characterize the architecture of firefly stemmata. I concluded that Photuris eyes were a type of fusion-stemmata, evidenced by a bi-lobed organization. Each eye contained 88 photoreceptors that contributed dense interlocking-microvilli forming a fused-rhabdom. In the next section, I tested whether stemmata regulated photo-dependent activity. I found that larvae were more active during nocturnal conditions, but unexpectedly, these behavioral patterns were not sufficiently explained by stemmata. Upon excision of the optic nerve, larvae maintained their activity preference to dark conditions, but this behavior was abolished upon removal of their head, suggesting an extraocular mechanism. In the final section, I demonstrated that stemmata were most sensitive to light in the blue/green part of the visible spectrum. Furthermore, using a chromatic adaptation assay, I showed that stemmata photoreceptors were consistent with having more than one spectrally distinct opsin. While a specific behavioral role for the larval eyes remain inconclusive, the macro- and ultrastructural results suggested the eyes have more sophisticated attributes than a simple light detector. This work has provided the framework upon which specific structure to function questions can be explored to advance our understanding of the Photuris firefly larval visual system