Jason P. Bell

Abdominal surgical incisions and perioperative morbidity among morbidly obese women undergoing cesarean delivery

OBJECTIVE To test the hypothesis that there is no difference in perioperative morbidity and the type of uterine incisions between vertical skin incisions (VSI) and low transverse skin incisions (LTSI) at the time of cesarean delivery in morbidly obese women. STUDY DESIGN Retrospective cohort study of morbidly obese women (BMI > 35 kg/m(2)) who underwent cesarean delivery between June 2004 and December 2006. RESULTS During the study, 424 morbidly obese women underwent cesarean section. Patients with VSI were older (31.0 ± 6.2 years vs. 26.7 ± 5.8 years), heavier (48.2 ± 9.1 kg/m(2) vs. 41.7 ± 6.7 kg/m(2)), and more likely to have a classical than a low transverse uterine incision (65.9% vs. 7.3%), p < 0.001. After controlling for confounders, women with VSI did not have an increase in perioperative morbidity, but underwent more vertical uterine incisions (adjusted odds ratio = 18.49, 95% CI: 6.44, 53.07). CONCLUSION VSI and LTSI are safe in morbidly obese patients undergoing cesarean section, but there is a tendency for increased vertical uterine incisions in those who underwent VSI.

A generalised Skolem-Mahler-Lech theorem for affine varieties

We give a corrected and strengthened statement and proof of the �p-adic analytic arc lemma� in a paper of the author (J. London Math. Soc. (2) 73 (2006) 367�379). We show that the analytic arc is guaranteed to exist for p 5 and give a counterexample showing that this sometimes cannot be done when p = 2.

The Dynamical Mordell–Lang Conjecture

* Introduction* Background material* The dynamical Mordell-Lang problem* A geometric Skolem-Mahler-Lech theorem* Linear relations between points in polynomial orbits* Parametrization of orbits* The split case in the dynamical Mordell-Lang conjecture* Heuristics for avoiding ramification* Higher dimensional results* Additional results towards the dynamical Mordell-Lang conjecture* Sparse sets in the dynamical Mordell-Lang conjecture* Denis-Mordell-Lang conjecture* Dynamical Mordell-Lang conjecture in positive characteristic* Related problems in arithmetic dynamics* Future directions* Bibliography* Index

On prime nonprimitive von Neumann regular algebras

Let E be any directed graph, and K any field. We classify those graphs E for which the Leavitt path algebra LK(E) is primitive. As a consequence, we obtain classes of examples of von Neumann regular prime rings which are not primitive.

Asymptotics for logical limit laws: When the growth of the components is in an RT class

Comptons method of proving monadic second-order limit laws is based on analyzing the generating function of a class of finite structures. For applications of his deeper results we previously relied on asymptotics obtained using Cauchys integral formula. In this paper we develop elementary techniques, based on a Tauberian theorem of Schur, that significantly extend the classes of structures for which we know that Comptons theory can be applied.

A DECISION PROBLEM FOR ULTIMATELY PERIODIC SETS IN NONSTANDARD NUMERATION SYSTEMS

Consider a nonstandard numeration system like the one built over the Fibonacci sequence where nonnegative integers are represented by words over {0,1} without two consecutive 1. Given a set X of integers such that the language of their greedy representations in this system is accepted by a finite automaton, we consider the problem of deciding whether or not X is a finite union of arithmetic progressions. We obtain a decision procedure for this problem, under some hypothesis about the considered numeration system. In a second part, we obtain an analogous decision result for a particular class of abstract numeration systems built on an infinite regular language.

Primitive ideals in quantum Schubert cells: Dimension of the strata

Abstract. The aim of this paper is to study the representation theory of quantum Schubert cells. Let 𝔤

Exponential lower bounds for the number of words of uniform length avoiding a pattern

\mathfrak {g}

Sufficient conditions for zero-one laws

be a simple complex Lie algebra. To each element w of the Weyl group W of 𝔤

Symmetric Groups and Quotient Complexity of Boolean Operations

\mathfrak {g}