Massive stars exploding in a He-rich circumstellar medium - IV. Transitional Type Ibn supernovae

We present ultraviolet, optical and near-infrared data of the Type Ibn supernovae (SNe) 2010al and 2011hw. SN 2010al reaches an absolute magnitude at peak of M-R = -18.86 +/- 0.21. Its early light curve shows similarities with normal SNe Ib, with a rise to maximum slower than most SNe Ibn. The spectra are dominated by a blue continuum at early stages, with narrow P-Cygni He I lines indicating the presence of a slow-moving, He-rich circumstellar medium. At later epochs, the spectra well match those of the prototypical SN Ibn 2006jc, although the broader lines suggest that a significant amount of He was still present in the stellar envelope at the time of the explosion. SN 2011hw is somewhat different. It was discovered after the first maximum, but the light curve shows a double peak. The absolute magnitude at discovery is similar to that of the second peak (M-R = -18.59 +/- 0.25), and slightly fainter than the average of SNe Ibn. Though the spectra of SN 2011hw are similar to those of SN 2006jc, coronal lines and narrow Balmer lines are clearly detected. This indicates substantial interaction of the SN ejecta with He-rich, but not H-free, circumstellar material. The spectra of SN 2011hw suggest that it is a transitional SN Ibn/IIn event similar to SN 2005la. While for SN 2010al the spectrophotometric evolution favours a H-deprived Wolf-Rayet progenitor (of WN-type), we agree with the conclusion of Smith et al. that the precursor of SN 2011hw was likely in transition from a luminous blue variable to an early Wolf-Rayet (Ofpe/WN9) stage.

Transitional Justice: Origins, Boundaries and Methods in Transitional Justice

Scholars and practitioners working in ‘transitional justice’ are concerned with remedies of accountability and redress in the aftermath of conflict and state repression. Transitional justice, it is argued, provides recognition of the rights of victims, promotes civic trust, and strengthens the democratic rule of law. As serious scholarship flourishes around this critical concept as never before, this new collection from Routledge meets the need for an authoritative reference work to map a vibrant site of research and reflection. In four volumes, Transitional Justice brings together foundational and the best and most influential cutting-edge materials, including key works produced before the term ‘transitional justice’ gained wide currency but which anticipate approaches now included under that rubric.

The collection covers themes such as: truth and history; acknowledgement, reconciliation, and forgiveness; retribution, restorative justice and reparations; and democracy, state-building, identity, and civil society

Transitional Justice: Conceptualising 'Transition'

Scholars and practitioners working in ‘transitional justice’ are concerned with remedies of accountability and redress in the aftermath of conflict and state repression. Transitional justice, it is argued, provides recognition of the rights of victims, promotes civic trust, and strengthens the democratic rule of law. As serious scholarship flourishes around this critical concept as never before, this new collection from Routledge meets the need for an authoritative reference work to map a vibrant site of research and reflection. In four volumes, Transitional Justice brings together foundational and the best and most influential cutting-edge materials, including key works produced before the term ‘transitional justice’ gained wide currency but which anticipate approaches now included under that rubric.

The collection covers themes such as: truth and history; acknowledgement, reconciliation, and forgiveness; retribution, restorative justice and reparations; and democracy, state-building, identity, and civil society

Role of early visual cortex in trans-saccadic memory of object features

Early visual cortex (EVC) participates in visual feature memory and the updating of remembered locations across saccades, but its role in the trans-saccadic integration of object features is unknown. We hypothesized that if EVC is involved in updating object features relative to gaze, feature memory should be disrupted when saccades remap an object representation into a simultaneously perturbed EVC site. To test this, we applied transcranial magnetic stimulation (TMS) over functional magnetic resonance imaging-localized EVC clusters corresponding to the bottom left/right visual quadrants (VQs). During experiments, these VQs were probed psychophysically by briefly presenting a central object (Gabor patch) while subjects fixated gaze to the right or left (and above). After a short memory interval, participants were required to detect the relative change in orientation of a re-presented test object at the same spatial location. Participants either sustained fixation during the memory interval (fixation task) or made a horizontal saccade that either maintained or reversed the VQ of the object (saccade task). Three TMS pulses (coinciding with the pre-, peri-, and postsaccade intervals) were applied to the left or right EVC. This had no effect when (a) fixation was maintained, (b) saccades kept the object in the same VQ, or (c) the EVC quadrant corresponding to the first object was stimulated. However, as predicted, TMS reduced performance when saccades (especially larger saccades) crossed the remembered object location and brought it into the VQ corresponding to the TMS site. This suppression effect was statistically significant for leftward saccades and followed a weaker trend for rightward saccades. These causal results are consistent with the idea that EVC is involved in the gaze-centered updating of object features for trans-saccadic memory and perception.