14 research outputs found

    Prediction Properties of Aitken's Iterated Delta^2 Process, of Wynn's Epsilon Algorithm, and of Brezinski's Iterated Theta Algorithm

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    The prediction properties of Aitken's iterated Delta^2 process, Wynn's epsilon algorithm, and Brezinski's iterated theta algorithm for (formal) power series are analyzed. As a first step, the defining recursive schemes of these transformations are suitably rearranged in order to permit the derivation of accuracy-through-order relationships. On the basis of these relationships, the rational approximants can be rewritten as a partial sum plus an appropriate transformation term. A Taylor expansion of such a transformation term, which is a rational function and which can be computed recursively, produces the predictions for those coefficients of the (formal) power series which were not used for the computation of the corresponding rational approximant.Comment: 34 pages, LaTe

    Scalar Levin-Type Sequence Transformations

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    Sequence transformations are important tools for the convergence acceleration of slowly convergent scalar sequences or series and for the summation of divergent series. Transformations that depend not only on the sequence elements or partial sums sns_n but also on an auxiliary sequence of so-called remainder estimates ωn\omega_n are of Levin-type if they are linear in the sns_n, and nonlinear in the ωn\omega_n. Known Levin-type sequence transformations are reviewed and put into a common theoretical framework. It is discussed how such transformations may be constructed by either a model sequence approach or by iteration of simple transformations. As illustration, two new sequence transformations are derived. Common properties and results on convergence acceleration and stability are given. For important special cases, extensions of the general results are presented. Also, guidelines for the application of Levin-type sequence transformations are discussed, and a few numerical examples are given.Comment: 59 pages, LaTeX, invited review for J. Comput. Applied Math., abstract shortene

    Off-Label Biologic Regimens in Psoriasis: A Systematic Review of Efficacy and Safety of Dose Escalation, Reduction, and Interrupted Biologic Therapy

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    Objectives: While off-label dosing of biologic treatments may be necessary in selected psoriasis patients, no systematic review exists to date that synthesizes the efficacy and safety of these off-label dosing regimens. The aim of this systematic review is to evaluate efficacy and safety of off-label dosing regimens (dose escalation, dose reduction, and interrupted treatment) with etanercept, adalimumab, infliximab, ustekinumab, and alefacept for psoriasis treatment

    Suicide among persons with childhood leukaemia in Slovenia

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    Pri osebah, ki so v otroštvu zbolele za rakom, so pogosto prisotne telesne in psihosocialne posledice bolezni ter njenega zdravljenja. Mnoge raziskave so pokazale, da je pri osebah z izkušnjo raka v otroštvu depresivnost in samomorilno vedenje močneje izraženo. V naši raziskavi smo proučili pojavljanje samomorov pri osebah, ki so v otroštvu zbolele za levkemijo, v primerjavi s splošno populacijo v Sloveniji, v obdobju 1978–2010. Pričakovano število samomorov smo izračunali na osnovi kontrolne skupine posameznikov iz splošne populacije, ki je bila s skupino preiskovancev, tj. oseb, ki so v otroštvu zbolele za levkemijo, izenačena po spolu, starosti ob začetku opazovanja, letu začetka opazovanja in dolžini opazovanja. Raziskava je pokazala, da med tistimi, ki so v otroštvu zboleli za levkemijo, v letih 1978–2010 nobena oseba ni storila samomora, kar se statistično značilno ne razlikuje od pričakovanega števila samomorov (0,448) v primerljivi splošni populaciji v Sloveniji. Ugotovitve raziskave nakazujejo, da kljub znano bolj izraženem samomorilnem vedenju med preživelimi raka v otroštvu v Sloveniji v primerjavi s splošno populacijo pojavljanje samomorov pri osebah, zbolelih za levkemijo v otroštvu, ni pogostejše kot v splošni populaciji.Persons with childhood leukaemia often suffer from physical and psychosocial consequences of the disease and its treatment. Several studies have shown that depression and suicidal behaviour are expressed strongly in persons with a childhood cancer experience. In our study, we researched the occurrence of suicides among persons with childhood leukaemia compared to the general population in Slovenia in the period 1978–2010. The expected number of suicides was calculated based on the control group of individuals from the general population with the same gender, age at the beginning of observation, starting year and duration of observation as the research group, thus group of persons with childhood cancer. The study showed that none of the persons with childhood cancer committed suicide in the period 1978-2010, which is not statistically different from the expected number of suicides (0.448) in comparison with the general population in Slovenia. The findings of this study indicate that, despite the significantly increased expression of suicidal behaviour among survivors of childhood leukaemia in Slovenia compared to the general population, suicides do not occur more often among people with childhood leukaemia than among the general population
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