What is a miracle?

Based on arguments from theology and the philosophy of science, a miracle may be defined as: (1) a real, individual event, the occurrence of which must be (or must have been), at least in principle, susceptible to empirical verification; (2) an event which must be extremely unusual or historically unprecedented from the perspective of empirical scientific knowledge; (3) must evoke widespread wonder; (4) must be something freely given by God and not conjured; (5) must be understood as a special sign from God that transcends the bare facts of the case and communicates a spiritual message; and (6) must have been affirmed as a miracle by the community of believers to whom the message of the miracle must be addressed, at least indirectly.     

What is a pathogen?

The question 'what is a pathogen?' derives from pathogen-centered views of microbial pathogenesis that invoke microbial characteristics to explain virulence. However, virulence cannot be an independent microbial variable since it is only expressed in a susceptible host. Hence, the question 'what is a pathogen?' cannot be separated from the question 'what is a host?' Given that virulence is an outcome of the host-microbe interaction that is not invariant from host to host, neither the pathogen or the host can be defined independently. To sidestep this paradox, one can focus on the outcome of the interaction using host damage as the common denominator to define and explain the various outcomes that can result from the host-microbe interaction. Using this concept a pathogen is defined as a microbe capable of causing host damage.     

What is a pressure-volume curve?

The pressure-volume (PV) curve is a physiological tool proposed for diagnostic or monitoring purposes during mechanical ventilation of acute respiratory distress syndrome. The reduction in compliance measured by the PV curve and the different inflection points on the curve are considered interesting markers of the severity of and the levels of opening and closing pressures. Tracing a curve, however, may in itself influence the degree of opening or distension of the lung, and interpretation of the curve has to take this effect into account. In some individuals tracing the curve may even have moderate hemodynamic effects. Fortunately, on average, most of these effects are transient or negligible and do not invalidate the PV curve measurement.