Say their names: Resurgence in the collective attention toward Black victims of fatal police violence following the death of George Floyd.

The murder of George Floyd by police in May 2020 sparked international protests and brought unparalleled levels of attention to the Black Lives Matter movement. As we show, his death set record levels of activity and amplification on Twitter, prompted the saddest day in the platform's history, and caused his name to appear among the ten most frequently used phrases in a day, where he is the only individual to have ever received that level of attention who was not known to the public earlier that same week. Importantly, we find that the Black Lives Matter movement's rhetorical strategy to connect and repeat the names of past Black victims of police violence-foregrounding racial injustice as an ongoing pattern rather than a singular event-was exceptionally effective following George Floyd's death: attention given to him extended to over 185 prior Black victims, more than other past moments in the movement's history.

Primary Ewing sarcoma of the lung: a challenging case.

Ewing sarcoma usually develops in the second decade of life as a primary osseous malignancy. An extraskeletal primary source of this condition from the lung parenchyma is extremely uncommon. We report the case of a 33-year old man with primary Ewing sarcoma of the lung diagnosed upon postsurgical histological examination.

Direct diffusion through interpenetrating networks: oxygen in titanium.

How impurity atoms move through a crystal is a fundamental and recurrent question in materials. The previous models of oxygen diffusion in titanium relied on interstitial lattice sites that were recently found to be unstable--leaving no consistent picture of the diffusion pathways. Using first-principles quantum-mechanical methods, we find three oxygen interstitial sites in titanium, and quantify the multiple interpenetrating networks for oxygen diffusion.