In a distributed system, it is often important to detect the causal relationships between events, where event e 1 is causally before event e 2 if e 1 happened before e 2 and could possibly have aaected the occurrence of e 2. In this paper we argue that detecting causal relationships among events can be important for security, in the sense that it may be essential to the correct implementation o...

Buoyancy perturbations develop when stably stratified air ascends a mountain barrier. These perturbations often trigger disturbances that propagate away from the mountain as gravity (or buoyancy) waves. Gravity waves triggered by the flow over a mountain are referred to as mountain waves or lee waves. Mountain waves sometimes reveal their presence through dramatic cloud formations, such as smoo...

A 40 year old man had an episode of severe pulmonary oedema at 4000-5000 m during the ascent of the Margherita peak (5109 m) of Mount Stanley on the Ruwenzori. He had taken acetazolamide and high dose dexamethasone to treat symptoms of acute mountain sickness. Six years before he had been studied by right heart catheterisation as a healthy volunteer during hypoxic breathing at sea level. His pu...

1. To investigate the mechanisms of acute mountain sickness, 22 subjects travelled to 3100 m by road and the following day walked to 4300 m on Mount Kenya. Control measurements were made over 2 days at 1300 m before ascent and for 2 days after arrival at 4300 m. These included body weight, 24 h urine volume, 24 h sodium and potassium excretion, blood haemoglobin, packed cell volume, and symptom...

Rocky Mountain spotted fever is still the most lethal tick-vectored illness in the United States. We examine the dilemmas facing the clinician who is evaluating the patient with possible Rocky Mountain spotted fever, with particular attention to the following 8 pitfalls in diagnosis and treatment: (1) waiting for a petechial rash to develop before diagnosis; (2) misdiagnosing as gastroenteritis...

It is easy to live for the day. All lazybones do that and legitimately those who have finally taken a rest and enjoy in a relaxed way what is offered to them. The more eventful the better since then it is easy to forget what happened before and since unconnected impressions can be grasped in a particularly fresh way, in a virtually raw way. And in the same way as one might live for the moment, ...

As the name indicates, a renewal process is one that “renews” itself regularly. That is, there is a sequence of times {Tn, n ∈ Z} such that the process after time Tn is independent of what happened before that time and has a distribution that does not depend on n. We have seen examples of such processes before. As a simple example, one could consider a Poisson process with jump times Tn. As ano...

Products of voluminous pyroclastic eruptions with eruptive draw-down of several kilometers provide a snap-shot view of batholith-scale magma chambers, and quench pre-eruptive isotopic fractionations (i.e., temperatures) between minerals. We report analyses of oxygen isotope ratio in individual quartz phenocrysts and concentrates of magnetite, pyroxene, and zircon from individual pumice clasts o...

the sofeh mountain in the south of isfahan (iran) has a development of shafts (vertical cave). simorgh cave with a depth of 42 m and a length of 52 m has developed along significant fault structures. structural analysis indicates relationships of orientation between the faults and fractures and shafts and chambers geometries. considering the main ne-sw trend of tectonic structures in the area, ...