On the Instrumental Discrepancies in Lyman-Alpha Observations of Solar Flares.

Despite the energetic significance of Lyman-alpha (Ly ; 1216 Å) emission from solar flares, regular observations of flare related Ly have been relatively scarce until recently. Advances in instrumental capabilities and a shift in focus over previous solar cycles mean it is now routinely possible to take regular co-observations of Ly emission in solar flares. Thus, it is valuable to examine how the instruments selected for flare observations may influence the conclusions drawn from the analysis of their unique measurements.

A theoretical network model to analyse neurogenesis and synaptogenesis in the dentate gyrus.

We describe a strongly biologically motivated artificial neural network approach to model neurogenesis and synaptic turnover as it naturally occurs for example in the hippocampal dentate gyrus (DG) of the developing and adult mammalian and human brain. The results suggest that cell proliferation (CP) has not only a functional meaning for computational tasks and learning but is also relevant for maintaining homeostatic stability of the neural activity. Moderate rates of CP buffer disturbances in input activity more effectively than networks without or very high CP.