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Near-surface warming in the Arctic has been almost twice as large as the global average over the past few decades. The vertical structure of temperature change in this region during the late twentieth century is examined and evidence is found for temperature amplification well above the surface. The causes of this amplification aloft remain uncertain, as feedbacks associated with the recent reduction in snow and ice cover are unlikely to be the cause.
A theoretical study proposes that magnetic monopoles may appear not as elementary but as emergent particles in complex, strongly-correlated magnetic systems such as spin ice, in analogy to fractional electric charges in quantum Hall systems. This theory explains a mysterious phase transition in spin ice that has been observed experimentally.
Numb functions as a tumour suppressor protein by regulating another tumour suppressor, p53. Numb binds and inhibits the activity of the ubiquitin ligase HDM2, and thereby promotes p53 stability and function. Low levels of Numb expression in breast tumours is associated with a poor prognosis.
