Adaptation of pineal expressed teleost exo-rod opsin to non-image forming photoreception through enhanced Meta II decay

Photoreception by vertebrates enables both image-forming vision and non-image-forming responses such as circadian photoentrainment. Over the recent years, distinct non-rod non-cone photopigments have been found to support circadian photoreception in diverse species. By allowing specialization to this sensory task a selective advantage is implied, but the nature of that specialization remains elusive. We have used the presence of distinct rod opsin genes specialized to either image-forming (retinal rod opsin) or non-image-forming (pineal exo-rod opsin) photoreception in ray-finned fish (Actinopterygii) to gain a unique insight into this problem. A comparison of biochemical features for these paralogous opsins in two model teleosts, Fugu pufferfish (Takifugu rubripes) and zebrafish (Danio rerio), reveals striking differences. While spectral sensitivity is largely unaltered by specialization to the pineal environment, in other aspects exo-rod opsins exhibit a behavior that is quite distinct from the cardinal features of the rod opsin family. While they display a similar thermal stability, they show a greater than tenfold reduction in the lifetime of the signaling active Meta II photoproduct. We show that these features reflect structural changes in retinal association domains of helices 3 and 5 but, interestingly, not at either of the two residues known to define these characteristics in cone opsins. Our findings suggest that the requirements of non-image-forming photoreception have lead exo-rod opsin to adopt a characteristic that seemingly favors efficient bleach recovery but not at the expense of absolute sensitivity

A ‘Third Culture’ in Economics? An Essay on Smith, Confucius and the Rise of China

China's rise drives a growing impact of China on economics. So far, this mainly works via the force of example, but there is also an emerging role of Chinese thinking in economics. This paper raises the question how far Chinese perspectives can affect certain foundational principles in economics, such as the assumptions on individualism and self-interest allegedly originating in Adam Smith. I embark on sketching a 'third culture' in economics, employing a notion from cross-cultural communication theory, which starts out from the observation that the Chinese model was already influential during the European enlightenment, especially on physiocracy, suggesting a particular conceptualization of the relation between good government and a liberal market economy. I relate this observation with the current revisionist view on China's economic history which has revealed the strong role of markets in the context of informal institutions, and thereby explains the strong performance of the Chinese economy in pre-industrial times. I sketch the cultural legacy of this pattern for traditional Chinese conceptions of social interaction and behavior, which are still strong in rural society until today. These different strands of argument are woven together in a comparison between Confucian thinking and Adam Smith, especially with regard to the 'Theory of Moral Sentiments', which ends up in identifying a number of conceptual family resemblances between the two. I conclude with sketching a 'third culture' in economics in which moral aspects of economic action loom large, as well as contextualized thinking in economic policies