In this paper we study the properties of systems of bounded arithmetic capturing small complexity classes and state conditions sufficient for such systems to capture the corresponding complexity class tightly. Our class of systems of bounded arithmetic is the class of secondorder systems with comprehension axiom for a syntactically restricted class of formulas Φ ⊂ Σ 1 based on a logic in the de...

This is a survey paper on the descriptive set theory of hereditary families of closed sets in Polish spaces. Most of the paper is devoted to ideals and σ-ideals of closed or compact sets.

The classical descriptive set theory is devoted to the study of descriptive classes of sets in Polish spaces. There are many deep results which found applications, e.g., in real analysis or functional analysis. Several books and survey papers contain essential parts of this theory, see [49], [2], [48], [54], [63]. One of the key tools for the study of Borel sets in Polish spaces are analytic sp...

Background: Giving birth is one of the most important events in a woman’s life and highly individualistic unique experience. Objectives: The study aimed to describe women’s childbirth experiences two state hospitals KwaZulu-Natal. Method: A non-experimental, quantitative, descriptive survey low-risk mothers was conducted by using Childbirth Experience Questionnaire (CEQ). Results: With response...

This article is the second in a series that lists four key explanatory or tutorial references for each of 29 chemometric methods previously described. The selected are particularly helpful to explain use method spectroscopic data. Also included common computer software platforms used chemometrics.