EUSO-SPB1 mission and science

The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of ⪆ 3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search

Laser Treatment of Benign Prostatic Obstruction: Basics and Physical Differences

Context: Laser treatment of benign prostatic obstruction (BPO) has become more prevalent in recent years. Although multiple surgical approaches exist, there is confusion about laser-tissue interaction, especially in terms of physical aspects and with respect to the optimal treatment modality. Objective: To compare available laser systems with respect to physical fundamentals and to discuss the similarities and differences among introduced laser devices. Evidence acquisition: The paper is based on the second expert meeting on the laser treatment of BPO organised by the European Association of Urology Section of Uro-Technology. A systematic literature search was also carried out to cover the topic of laser treatment of BPO extensively. Evidence synthesis: The principles of generation of laser radiation, laser fibre construction, the types of energy emission, and laser-tissue interaction are discussed in detail for the laser systems used in the treatment of BPO. The most relevant laser systems are compared and their physical properties discussed in depth. Conclusions: Laser treatment of BPO is gaining widespread acceptance. Detailed knowledge of the physical principles allows the surgeon to discriminate between available laser systems and their possible pitfalls to guarantee high safety levels for the patient. (C) 2011 European Association of Urology. Published by Elsevier B. V. All rights reserved