66 research outputs found

    A numeric study of power expansions around singular points of algebraic functions, their radii of convergence, and accuracy profiles

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    An efficient method of computing power expansions of algebraic functions is the method of Kung and Traub and is based on exact arithmetic. This paper shows a numeric approach is both feasible and accurate while also introducing a performance improvement to Kung and Traub's method based on the ramification extent of the expansions. A new method is then described for computing radii of convergence using a series comparison test. Series accuracies are then fitted to a simple log-linear function in their domain of convergence and found to have low variance. Algebraic functions up to degree 50 were analyzed and timed. A consequence of this work provided a simple method of computing the Riemann surface genus and was used as a cycle check-sum. Mathematica ver. 13.2 was used to acquire and analyze the data on a 4.0 GHz quad-core desktop computer.Comment: 28 pages, 19 tables, 12 figures Ver 2 corrections: (1) Added absolute value bars for note about R in summary report of Test Case 6 (2) 5-degree function f_2 in eqn. (24) was wrong function for this test case. Changed to correct 4-degree function. All tables of this test case reflected the results of the 4-degree function and were not change

    Caratterizzazione e valutazione dell\u2019attivit\ue0 anti proliferativa di nuovi sistemi per il drug carrier Allosite-sali triazolici/cardanolo

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    Da precedenti studi \ue8 stato valutato che i nanotubi di allosite modificati con sali triazolici (f-HNT), sono dei promettenti sistemi carrier per molecole biologiche1. In questo lavoro si riportano i risultati ottenuti studiando gli f-HNT come carrier per il cardanolo, molecola con interessanti attivit\ue0 biologiche. L\u2019interazione fra il cardanolo e gli f-HNT \ue8 stata valutata tramite HPLC, spettroscopia FTIR, analisi termogravimentrica, misure di angolo di contatto e microscopia a scansione elettronica. Infine sono stati studiati sia il rilascio del cardanolo dal sistema che gli effetti citotossici del complesso f-HNT/Cardanolo verso linee cellulari di epatocarcinoma. I dati sperimentali ottenuti mostrano che l\u2019allosite risulta un promettente sistema atto al drug carrier

    Topical corticosteroid phobia in parents of pediatric patients with atopic dermatitis: a multicentre survey

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    BACKGROUND: Families of children affected with atopic dermatitis (AD) often report fear and anxiety regarding treatment with topical corticosteroids (TCS), which may lead to reduced compliance. The objective of our study was to measure, through a standardized questionnaire, fear of TCS in families of pediatric patients with AD and to identify items associated with fear. METHODS: Families of pediatric patients with AD were enrolled in 9 Italian centers of pediatric dermatology. Enrolled parents were invited to fill in a questionnaire including questions on sociodemographic and clinical characteristics and 3 sets of questions on corticosteroid phobia (general fear, specific fears, behaviours regarding TCS). Determinants of the level of general fear were investigated through multivariable analysis. RESULTS: A total of 300 outpatients with AD were enrolled. Most parents (80%) had a high instruction level. Eighty-one percent reported to have a certain amount of fear of TCS. At the multivariable analysis, fear of TCS was associated with the following items: believing that TCS treatment advantages do not overweight disadvantages (P = 0.011); believing that TCS may be dangerous independently from the specific side effect (P < 0.001). Moreover, TCS fear was associated with fear of applying too much cream (P = 0.001). CONCLUSION: TCS phobia is widespread among Italian families of children with AD. Fear of TCS is associated with fear of applying too much cream, thus increasing the risk of poor compliance and treatment failure. Therapeutic education of families on the use of TCS should be implemented. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13052-017-0330-7) contains supplementary material, which is available to authorized users

    Frontotemporal dementia causative CHMP2B impairs neuronal endolysosomal traffic-rescue by TMEM106B knockdown

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    Mutations in the endosome-associated protein CHMP2B cause frontotemporal dementia and lead to lysosomal storage pathology in neurons. We here report that physiological levels of mutant CHMP2B causes reduced numbers and significantly impaired trafficking of endolysosomes within neuronal dendrites, accompanied by increased dendritic branching. Mechanistically, this is due to the stable incorporation of mutant CHMP2B onto neuronal endolysosomes, which we show renders them unable to traffic within dendrites. This defect is due to the inability of mutant CHMP2B to recruit the ATPase VPS4, which is required for release of CHMP2B from endosomal membranes. Strikingly, both impaired trafficking and the increased dendritic branching were rescued by treatment with antisense oligonucleotides targeting the well validated frontotemporal dementia risk factor TMEM106B, which encodes an endolysosomal protein. This indicates that reducing TMEM106B levels can restore endosomal health in frontotemporal dementia. As TMEM106B is a risk factor for frontotemporal dementia caused by both C9orf72 and progranulin mutations, and antisense oligonucleotides are showing promise as therapeutics for neurodegenerative diseases, our data suggests a potential new strategy for treating the wide range of frontotemporal dementias associated with endolysosomal dysfunction
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