OBJECTIVES To assess the efficacy of three different daily doses of acetazolamide in the prevention of acute mountain sickness and to determine the lowest effective dose. DESIGN Systematic review and meta-analysis. DATA SOURCES Medline and Embase along with a hand search of selected bibliographies. No language restrictions were applied. STUDY SELECTION Randomised controlled trials assessi...

I propose a new measure of common, time-varying tail risk for large cross sections of stock returns. Stock return tails are described by a power law in which the power law exponent is allowed to transition smoothly through time as a function of recent data. It is motivated by asset pricing theory and is estimable via quasi-maximum likelihood. Estimates indicate substantial time variation in sto...

In a distributed system, it is often important to detect the causal relationships between events, where event e1 is causally before event e2 if e1 happened before e2 and could possibly have aaected the occurrence of e2. In this paper we argue that it can be essential to security that a process determine, in the face of malicious attack, how two events are causally related. We formulate attacks ...

In this article, we present a particle filter (PF)-based track-before-detect (PF TBD) procedure for detection of extended objects whose shape is modeled by an ellipse. By incorporating of an existence variable and the target shape parameters into the state vector, the proposed algorithm performs joint estimation of the target presence/ absence, trajectory and shape parameters under unknown nuis...

the mountains as the other natural environment are the main purposes for nature based tourism such as sport tourism and have a finite capacity for recreation development which differs from one place to another and naturally causes different type of tourism’s development. therefore land suitability is very important before tourism planning. some charactristics like geomorphological, biological a...

Knowledge of the dimensions of a stable stream channel during a specific period of time and of its corresponding forming discharge allows determining parameters of regime equations for a region, which enhance the design of channels in other zones with similar characteristics. Nowadays, the state-of-the-art for regime channel does not include the typical streams of the Department of Cauca charac...

In a high mountain lake and catchment area, a natural process of phosphorus enrichment is observed, induced by the iron-cycle. Investigations focus on the speciation of P and Fe in iron and manganese rich oxidic mineral crusts formed at the surface of rock pebbles. Iron and phosphorus are spatially associated although they are not forming iron phosphate minerals. While Fe and P K edge XAS spect...

Mountain running is a non-Olympic sport consisting of uphill or up- and downhill races at moderate-to-high altitude. Special nutritional requirements are anticipated, but no nutritional data of mountain runners are available. In three studies, physique of elite and recreational athletes (N = 62), maximum oxygen uptake (N = 3), and prerace and race day dietary intake (N = 6) were measured (mean ...

The evolution of mountain-wave-induced momentum flux is examined through idealized numerical simulations during the passage of a time-evolving synoptic-scale flow over an isolated 3D mountain of height h. The dynamically consistent synoptic-scale flow U accelerates and decelerates with a period of 50 h; the maximum wind arrives over the mountain at 25 h. The synoptic-scale static stability N is...