Gamma-Ray and Radio-Frequency Radiation from Thunderstorms Observed from Space and Ground.

Terrestrial gamma ray flashes (TGFs) are a class of enigmatic electrical discharges in the Earth's atmosphere. In this study, we analyze an unprecedentedly large dataset comprised of 2188 TGFs whose signatures were simultaneously measured using space- and ground-based detectors over a five-year period. The Gamma-ray Burst Monitor (GBM) on board the Fermi spacecraft provided the energetic radiation measurements. Radio frequency (RF) measurements were obtained from the Global Lightning Dataset (GLD360). Here we show the existence of two categories of TGFs - those that were accompanied by quasi-simultaneous electromagnetic pulses (EMPs) detected by the GLD360 and those without such simultaneous EMPs. We examined, for the first time, the dependence of the TGF-associated EMP-peak-amplitude on the horizontal offset distance between the Fermi spacecraft and the TGF source. TGFs detected by the GBM with sources at farther horizontal distances are expected to be intrinsically brighter and were found to be associated with EMPs having larger median peak-amplitudes. This provides independent evidence that the EMPs and TGFs are produced by the same phenomenon, rather than the EMPs being from "regular" lightning in TGF-producing thunderstorms.

Heterotopic ossificans in chronic venous insufficiency: a new consideration for clinical, aetiology, anatomy and pathophysiology staging.

OBJECTIVES: Heterotopic ossification is defined as the abnormal formation of true bone within extra-skeletal soft tissues. It may be associated with a variety of clinical conditions, but is most frequently seen with musculoskeletal trauma, neurologic injury or genetic abnormalities. It has also been described in patients with chronic venous insufficiency; however, it often goes underdiagnosed due to chronic ulceration that masks exam findings. To date, few reports of heterotopic ossification due to chronic venous disease exist within the literature with the most recent dating back to the 1970s. METHODS: We present a case study of a man presenting with extensive leg ulceration and a history of chronic venous insufficency. He had a large non-healing venous stasis ulcer of the left lower extremity with extensive heterotopic ossification discovered intraoperatively. RESULTS: The patient was managed with serial wound debridement, innovative woundcare and eventual split thickness skin grafting that achieved limb salvage despite the complexity of his wound. CONCLUSIONS: Our discussion focuses on the epidemiology, pathophysiology, diagnostic work-up and management of heterotopic ossification in the setting of chronic venous insufficiency. We propose that heterotopic ossification be included in any future modifications of the clinical, aetiology, anatomy and pathophysiology system classification as a complication of chronic venous disease.