Abstract:
Background: Tuberculosis is currently the world’s leading cause of death arising from a single infectious condition. While T cell mediated immunity is recognized to have a major contribution to tuberculosis activation, the present investigation confirmed that TB was more prevalent among patients with acute myeloid rather than lymphoid leukemia and such association was frequently overlooked. The primary objective of this study is to estimate the diagnostic delay of tuberculosis among patients with acute myeloid leukemia (AML) and compare it to the general population in Qatar. Secondary objective is to study the clinical and epidemiologic characteristics of tuberculosis in patients with AML. Methods: This is a retrospective study of tuberculosis cases diagnosed in subjects with AML during the period from January 2008 till December 2016. Results: Among 215 subjects with AML identified during the study period, 12 (5.58%) received the diagnosis of tuberculosis. The estimated incidence of tuberculosis among AML cases was 7.14 cases per 1000 per year. The mean delay in diagnosis of tuberculosis was 64.2 days (95% CI: 26.8 - 101.5) and the median was 45 days (interquartile range; Q1 - Q3, 29.5 - 97.5). Prolonged fever was the most common presentation (100% of cases). Parenchymal lung involvement was the most common radiologic abnormality (83.3% of cases). Three patients (25%) died and 8 patients completed 9 to 12 months of anti-tuberculous treatment with clinical and radiological remission. Conclusion: Infections caused by Mycobacterium tuberculosis are not uncommon in patients with AML especially in patients from tuberculosis endemic regions. It constitutes a diagnostic challenge so high index of suspicion is of paramount importance.

Abstract:
This is a survey on discrete linear operators which, besides approximating in Jackson or near-best order, possess some interpolatory property at some nodes. Such operators can be useful in numerical analysis.

Abstract:
For a wide class of weights, a systematic investigation of the convergence-divergence behavior of Lagrange interpolation is initiated. A system of nodes with optimal Lebesgue constant is found, and for Hermite weights an exact lower estimate of the norm of projection operators isgiven. In the same spirit, the case of Hermite–Fejér interpolation is also considered.

Abstract:
For a wide class of weights, a systematic investigation of the convergence-divergence behavior of Lagrange interpolation is initiated. A system of nodes with optimal Lebesgue constant is found, and for Hermite weights an exact lower estimate of the norm of projection operators isgiven. In the same spirit, the case of Hermite ￠ € “Fej r interpolation is also considered.

Abstract:
Developments of this far-reaching research field are summarized from an observational point of view, mentioning important and interesting phenomena discovered recently by photometry of stellar oscillations of any kind. A special emphasis is laid on Cepheids and RR Lyrae type variables.

Abstract:
This is a survey on discrete linear operators which, besides approximating in Jackson or near-best order, possess some interpolatory property at some nodes. Such operators can be useful in numerical analysis.

Abstract:
The fractional Brownian motion is a generalization of ordinary Brownian motion, used particularly when long-range dependence is required. Its explicit introduction is due to B.B. Mandelbrot and J.W. van Ness (1968) as a self-similar Gaussian process $\WH (t)$ with stationary increments. Here self-similarity means that $(a^{-H}\WH(at): t \ge 0) \stackrel{d}{=} (\WH(t): t \ge 0)$, where $H\in (0, 1)$ is the Hurst parameter of fractional Brownian motion. F.B. Knight gave a construction of ordinary Brownian motion as a limit of simple random walks in 1961. Later his method was simplified by P. R\'ev\'esz (1990) and then by the present author (1996). This approach is quite natural and elementary, and as such, can be extended to more general situations. Based on this, here we use moving averages of a suitable nested sequence of simple random walks that almost surely uniformly converge to fractional Brownian motion on compacts when $H \in (\quart , 1)$. The rate of convergence proved in this case is $O(N^{-\min(H-\quart,\quart)}\log N)$, where $N$ is the number of steps used for the approximation. If the more accurate (but also more intricate) Koml\'os, Major, Tusn\'ady (1975, 1976) approximation is used instead to embed random walks into ordinary Brownian motion, then the same type of moving averages almost surely uniformly converge to fractional Brownian motion on compacts for any $H \in (0, 1)$. Moreover, the convergence rate is conjectured to be the best possible $O(N^{-H}\log N)$, though only $O(N^{-\min(H,\half)}\log N)$ is proved here.

Abstract:
An elementary construction of the Wiener process is discussed, based on a proper sequence of simple symmetric random walks that uniformly converge on bounded intervals, with probability 1. This method is a simplification of F.B. Knight's and P. R\'ev\'esz's. The same sequence is applied to give elementary (Lebesgue-type) definitions of It\^o and Stratonovich sense stochastic integrals and to prove the basic It\^o formula. The resulting approximating sums converge with probability 1. As a by-product, new elementary proofs are given for some properties of the Wiener process, like the almost sure non-differentiability of the sample-functions. The purpose of using elementary methods almost exclusively is twofold: first, to provide an introduction to these topics for a wide audience; second, to create an approach well-suited for generalization and for attacking otherwise hard problems.

Abstract:
The present status of the quasi-local mass, energy-momentum and angular-momentum constructions in general relativity is reviewed. First, the general ideas, concepts, and strategies, as well as the necessary tools to construct and analyze the quasi-local quantities, are recalled. Then, the various specific constructions and their properties (both successes and deficiencies are discussed. Finally, some of the (actual and potential) applications of the quasi-local concepts and specific constructions are briefly mentioned.This review is based on talks given at the Erwin Schr dinger Institute, Vienna in July 1997, at the Universit t Tübingen in May 1998, and at the National Center for Theoretical Sciences in Hsinchu, Taiwan and at the National Central University, Chungli, Taiwan, in July 2000.

Abstract:
The present status of the quasi-local mass-energy-momentum and angular momentum constructions in general relativity is reviewed. First the general ideas, concepts and strategies as well as the necessary tools to construct and analyze the quasi-local quantities are recalled. Then the various specific constructions and their properties (both successes and defects) are discussed. Finally, some of the (actual and potential) applications of the quasi-local concepts and specific constructions are briefly mentioned. This review is based on the talks given at the Erwin Schr dinger Institut, Vienna, in July 1997, at the Universit t Tübingen, in May 1998 and at the National Center for Theoretical Sciences in Hsinchu and at the National Central University, Chungli, Taiwan, in July 2000.