Publisher Correction: Measuring the ionisation fraction in a jet from a massive protostar.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Measuring the ionisation fraction in a jet from a massive protostar.

It is important to determine if massive stars form via disc accretion, like their low-mass counterparts. Theory and observation indicate that protostellar jets are a natural consequence of accretion discs and are likely to be crucial for removing angular momentum during the collapse. However, massive protostars are typically rarer, more distant and more dust enshrouded, making observational studies of their jets more challenging. A fundamental question is whether the degree of ionisation in jets is similar across the mass spectrum. Here we determine an ionisation fraction of ~5-12% in the jet from the massive protostar G35.20-0.74N, based on spatially coincident infrared and radio emission. This is similar to the values found in jets from lower-mass young stars, implying a unified mechanism of shock ionisation applies in jets across most of the protostellar mass spectrum, up to at least ~10 solar masses.

Regional dissociation of paradigm-specific synapse remodeling during memory consolidation in the adult rat dentate gyrus.

Arising from studies on the amnesia that follows site-specific physical or chemical lesions, the acquisition and consolidation of certain behavioral tasks has been demonstrated to be associated with different hippocampal subregions. Although not absolute, spatial learning is reliant on the dorsal region of the hippocampus, whereas avoidance- and fear-conditioning tasks appear to be dependent on its more ventral aspects. Thus, if learning-associated synapse remodeling is a true feature of memory consolidation it must also follow these regional dissociations. We therefore determined if the learning-associated increases in synapse density that occur in the mid-molecular layer of the dentate gyrus at the 6-h post-training time and the frequency of polysialylated cells at the infragranular zone that occur at the 12-h post-training time were dissociated to specific hippocampal subregions following training in either a massed water maze task or light-dark passive avoidance response. Synapse remodeling was found to occur only in the dorsal hippocampus following spatial learning. We could not, however, discern any regional dissociation of neural remodeling following avoidance conditioning. These results point to strong associations between learning and specific groups of novel synapses during consolidation of spatial learning and avoidance conditioning paradigms.