Is recent major hurricane activity normal?

The anomaly of the recent increase in Atlantic major hurricane activity (MHA) is controversial. From a reconstruction of past MHA, Nyberg et al. conclude that the present activity is not unusual by comparison with that of the past 270 years. However, here I estimate the uncertainty of average MHA in the hurricane record before 1945 and show that the reconstruction of Nyberg et al. differs strongly from that record, and probably overestimates past MHA. Owing to this and further reasons, I question whether their reconstruction provides an accurate basis for conclusions about past MHA.     

High frequency of BRAF mutations in nevi

To evaluate the timing of mutations in BRAF (v-raf murine sarcoma viral oncogene homolog B1) during melanocytic neoplasia, we carried out mutation analysis on microdissected melanoma and nevi samples. We observed mutations resulting in the V599E amino-acid substitution in 41 of 60 (68%) melanoma metastases, 4 of 5 (80%) primary melanomas and, unexpectedly, in 63 of 77 (82%) nevi. These data suggest that mutational activation of the RAS/RAF/MAPK pathway in nevi is a critical step in the initiation of melanocytic neoplasia but alone is insufficient for melanoma tumorigenesis.