OBJECTIVE To assess the effect of R0 resection margin status and R0 en bloc resection in pancreatoduodenectomy outcomes. DESIGN Retrospective medical record review. SETTING Mayo Clinic, Rochester, Minnesota. PATIENTS Patients who underwent pancreatoduodenectomy for pancreatic adenocarcinoma at our institution between January 1, 1981, and December 31, 2007, were identified and their medica...

In this paper we consider the inventory problem with backorder such that both order and total demand quantities are triangular fuzzy numbers Q̃ = (q1, q0, q2), and R̃ = (r1, r0, r2) respectively, where q1 = q0−Δ1, q2 = q0+Δ2,r1 = r0−Δ3, r2 = r0+Δ4 such that 0 < Δ1 < q0, 0 < Δ2, 0 < Δ3 < r0, 0 < Δ4. Let s denote the maximum inventory quantity. Under conditions s ≤ q1 < q0 < q2 < r1 < r0 < r2, we f...

Clustering of cosmic-ray sources affects the flux observed beyond the cutoff imposed by the cosmic microwave background and may be important in interpreting the AGASA, Fly’s Eye, and HiRes data. The standard deviation, σ, in the predicted number, N , of events above 10 eV is σ/N = 0.9(r0/10Mpc) 0.9, where r0 is the unknown scale length of the correlation function (r0 ≃ 10 Mpc for field galaxies...

A parameterized model of the mass distribution within the Milky Way is fitted to the available observational constraints. Constraints at R < R0 and at R ≃ R0 are well satisfied, while those at 1 < R/R0 <∼ 2 cannot be adequately fitted with the consequence that the circular speed vc(R) at R > R0 is extremely uncertain. The most important single parameter is the ratio of the scale length Rd,∗ of ...

This paper focuses on a fundamental input parameter for most existing mathematical models of pandemic influenza, the ‘basic reproductive number R0,’ defined to be the mean number of new influenza infections created by a newly infected person in a population of all susceptible people. We argue that R0 is limited in policy and scientific value as is any single parameter attempting to characterize...

I reconsider the problem of the Newtonian limit in nonlinear gravity models in the light of recently proposed models Lgrav ∼ √−gf(R) with inverse powers of R. Expansion around a maximally symmetric local background with curvature scalar R0 > 0 gives the correct Newtonian limit on length scales ≪ R 0 if the gravitational Lagrangian √−gf(R) satisfies |f(R0)f (R0)| ≪ 1, and I propose two models wi...

The mean operator R0 and its dual R0 play an important role and have many applications, for example, in image processing of the so-called synthetic aperture radar (SAR) data [11, 12] or in the linearized inverse scattering problem in acoustics [6]. Our purpose in this work is to define and study integral transforms which generalize the operators R0 and R0. More precisely, we consider the follow...

We analyze stability of equilibria for a delayed SIR epidemic model, in which population growth is subject to logistic growth in absence of disease, with a nonlinear incidence rate satisfying suitable monotonicity conditions. The model admits a unique endemic equilibrium if and only if the basic reproduction number R0 exceeds one, while the trivial equilibrium and the disease-free equilibrium a...