Decision Problems For Convex Languages

In this paper we examine decision problems associated with various classes of convex languages, studied by Ang and Brzozowski (under the name "continuous languages"). We show that we can decide whether a given language L is prefix-, suffix-, factor-, or subword-convex in polynomial time if L is represented by a DFA, but that the problem is PSPACE-hard if L is represented by an NFA. In the case that a regular language is not convex, we prove tight upper bounds on the length of the shortest words demonstrating this fact, in terms of the number of states of an accepting DFA. Similar results are proved for some subclasses of convex languages: the prefix-, suffix-, factor-, and subword-closed languages, and the prefix-, suffix-, factor-, and subword-free languages.Comment: preliminary version. This version corrected one typo in Section 2.1.1, line

Analgesie peridurale et fievre lors du travail. [Epidural analgesia and fever during labor]

Fever during labor is quite frequent and may be an etiologic and therapeutic challenge for obstetric and anesthesia teams. Although an infectious cause should be suspected first, intrapartum fever can also be non-infectious, most frequently in association with epidural analgesia. In this article, we review what is presently known about the association between epidural analgesia and intrapartum fever. Neonatal consequences of intrapartum fever are also discussed