Presynaptic partner selection during retinal circuit reassembly varies with timing of neuronal regeneration in vivo

Whether neurons can restore their original connectivity patterns during circuit repair is unclear. Taking advantage of the regenerative capacity of zebrafish retina, we show here the remarkable specificity by which surviving neurons reassemble their connectivity upon regeneration of their major input. H3 horizontal cells (HCs) normally avoid red and green cones, and prefer ultraviolet over blue cones. Upon ablation of the major (ultraviolet) input, H3 HCs do not immediately increase connectivity with other cone types. Instead, H3 dendrites retract and re-extend to contact new ultraviolet cones. But, if regeneration is delayed or absent, blue-cone synaptogenesis increases and ectopic synapses are made with red and green cones. Thus, cues directing synapse specificity can be maintained following input loss, but only within a limited time period. Further, we postulate that signals from the major input that shape the H3 HC's wiring pattern during development persist to restrict miswiring after damage

The individual, social justice and public health

A theoretical reflection on public health from a standpoint of social justice, which does not overlook the individual, is presented. Based on a conceptualization of social justice, human rights and health in the framework of an epistemological analysis, a particular perspective on social justice and its implications for public health praxis, using a public health program as an example, is revealed. Some routes are identified in order to orient and put into practice the actions developed in public health programs. This requires a different way of understanding the scenarios and interchanges among people in the field of clinical practice. It is understood that these fields can also be seen as a suitable opportunity for the establishment of individuals and individualities committed to the political struggle for human rights, equity in health and recognition of a life worthy of human dignity

A simple paradigm for nooconomics, the economy of knowledge

International audienceThe human noosphere and its inner dynamic are forming a fascinating yet poorly understood multiscale complex system, in which one may represent the interaction of individual knowledge holders and their collective dynamic. Here I propose a simple, improvable paradigm for noodynamics (the study of knowledge flows) and nooconomics at large (the economy of knowledge) based on two intrinsic properties of knowledge-its prolificity and collegiality-and on three simple transfer laws capturing some fundamental differences between material and immaterial economics, namely 1) that knowledge exchanges , unlike property exchanges, are flows, and thus time-dependent, 2) that knowledge exchanges are positive sum, unlike material exchanges and 3) that combinations of knowledge are non linear. I then make a suggestion for a basic knowledge flow equation, namely that transferred knowledge is proportional to the product of spent attention and time, and discuss some of its social and political implications. keywords: knowledge economy, noosphere, multiscale dynamic, knowledge flow, noodynam-ics The purpose of this article is to outline a simple and improvable paradigm for noody-namics, the study of knowledge flows. If we endow this paradigm with an economic perspective, and consider its agents buyers and sellers, it can then also be considered an early working paradigm, or more precisely, an early building block towards a working paradigm, for nooconomics, the economy of knowledge. I thus attempt to demonstrate that noodynamics can be codified extremely simply, although not entirely , and will leave the many exceptions to the present paradigm to discussion