An influential theory of increasing returns has been proposed by the economist W. B. Arthur in '80s to explain lock-in phenomenon between two competing commercial products. In most simplified situation there are products that gain customers according a majority mechanism: each new customer arrives and asks which product they bought certain odd number previous customers, then buy shared within t...

Let ( a k stretchy="false">) <mm...

background the nasal septal deviation (nsd) is one of the major causes of nasal obstruction. this condition increases upper airway resistance. in this study we evaluated the mean pulmonary artery pressure (mpap) in patients with markedly deviated septum. methods sixty two patients with nsd (age range: 26-45 years, 34 men and 28 women) were included in the study. mean pulmonary artery pressure w...