Miranda Zhao

Love, a concept revered across cultures and time, holds multifaceted meanings and roles in human experience. Plato, in his dialogues Symposium and Phaedrus, offers profound insights into the nature of love. However, Plato’s conception of love has been subject to criticism, with many viewing it as selfish, objectifying, and lacking in interpersonal connections. Central to these criticisms is the question of whether the lover’s affection for the beloved persists after grasping the concept of true beauty. In this thesis, I delve into Plato’s idea of love as presented in the Symposium and Phaedrus, aiming to demonstrate that Platonic love transcends mere self-interest, encompasses interpersonal love, and the lover’s love for the beloved endures even after grasping the true form of beauty.

© 2015 Wiley Periodicals, Inc. Cell fragments devoid of the nucleus and major organelles are found in physiology and pathology, for example platelets derived from megakaryocytes, and cell fragments from white blood cells and glioma cells. Platelets exhibit active chemotaxis. Fragments from white blood cells display chemotaxis, phagocytosis, and bactericidal functions. Signaling mechanisms underlying migration of cell fragments are poorly understood. Here we used fish keratocyte fragments and demonstrated striking differences in signal transduction in migration of cell fragments and parental cells in a weak electric field. cAMP or cGMP agonists completely abolished directional migration of fragments, but had no effect on parental cells. The inhibition effects were prevented by pre-incubating with cAMP and cGMP antagonists. Blocking cAMP and cGMP downstream signaling by inhibition of PKA and PKG also recovered fragment galvanotaxis. Both perturbations confirmed that the inhibitory effect was mediated by cAMP or cGMP signaling. Inhibition of cathode signaling with PI3K inhibitor LY294002 also prevented the effects of cAMP or cGMP agonists. Our results suggest that cAMP and cGMP are essential for galvanotaxis of cell fragments, in contrast to the signaling mechanisms in parental cells.