129 research outputs found
Statistics of nonlinear stochastic dynamical systems under Lévy noises by a convolution quadrature approach
No full textThis paper describes a novel numerical approach to find the statistics of the non-stationary response of scalar nonlinear systems excited by Lévy white noises. The proposed numerical procedure relies on the introduction of an integral transform of the Wiener–Hopf type into the equation governing the characteristic function. Once this equation is rewritten as partial integro-differential equation, it is then solved by applying the method of convolution quadrature originally proposed by Lubich, here extended to deal with this particular integral transform. The proposed approach is relevant for two reasons: (1) statistics of systems with several different drift terms can be handled in an efficient way, independently from the kind of white noise; (2) the particular form of Wiener–Hopf integral transform and its numerical evaluation, both introduced in this study, are generalizations of fractional integro-differential operators of potential type and Grünwald–Letnikov fractional derivatives, respectively
Leaving home, family support and intergenerational ties in Italy: Some regional differences
No full textIn Italy conditions at leaving home are characterized by high age at exit, high proximity with parents and widespread intergenerational support, showing important regional differences. According to the "familistic" approach such conditions spread from strong intergenerational ties. Proximity and support are considered proxies of ties’ strength so that different regional proximity and support correspond to different ties’ intensities. The study aims at analyzing similarities and differences about parent-child ties, proximity and support in selected Italian regions, Liguria, Umbria, Sicily and Sardinia. Results show important differences among regions with respect to proximity and support, suggesting different intensity of intergenerational ties.family ties, intergenerational proximity, intergenerational support, regional comparison
Nonlinear SDE Excited by External Lévy White Noise Processes
No full textA numerical method for approximating the statistics of the solution of nonlinear stochastic systems excited by Gaussian and non-Gaussian external white noises is proposed. The differential equation governing the evolution in time of the characteristic function is resolved by the convolution quadrature method. This
approach is especially suited for those problems in which the nonlinear drift term is not of polynomial form.
In such cases the equation governing the evolution in time of the characteristic function is not a partial differential equation. Statistics are found by introducing an integral operator of Wiener-Hopf type, called the transformation operator, and applying the Lubich's convolution quadrature. This leads to find the statistics of the response by solving a linear system of differential equations
UNRESECTABLE HEPATOCELLULAR CARCINOMA:META-ANALYSIS OD ARTERIAL EMBOLIZATION
No full text. Radiology. 2002 Jul;224(1):47-54.
Transarterial chemoembolization for unresectable hepatocellular carcinoma:
meta-analysis of randomized controlled trials.
Cammà C, Schepis F, Orlando A, Albanese M, Shahied L, Trevisani F, Andreone P,
Craxì A, Cottone M.
National Council of Research, Istituto Metodologie Diagnostiche Avanzate,
Palermo, Italy. [email protected]
Comment in
Radiology. 2003 May;227(2):611-2; author reply 612-3.
Radiology. 2004 Jan;230(1):300-1; author reply 301-2.
PURPOSE: To review the available evidence of chemoembolization for unresectable
hepatocellular carcinoma (HCC).
MATERIALS AND METHODS: Computerized bibliographic searches with MEDLINE and
CANCERLIT databases from 1980 through 2000 were supplemented with manual
searches, with the keywords "hepatocellular carcinoma," "liver cell carcinoma,"
"randomized controlled trial [RCT]," and "chemoembolization." Studies were
included if patients with unresectable HCC were enrolled and if they were RCTs in
which chemoembolization was compared with nonactive treatment (five RCTs) or if
different transarterial modalities of therapy (13 RCTs) were compared. Data were
extracted from each RCT according to the intention-to-treat method. Five of the
RCTs with a nonactive treatment arm were combined by using the random-effects
model, whereas all 18 RCTs were pooled from meta-regression analysis.
RESULTS: Chemoembolization significantly reduced the overall 2-year mortality
rate (odds ratio, 0.54; 95% CI: 0.33, 0.89; P =.015) compared with nonactive
treatment. Analysis of comparative RCTs helped to predict that overall mortality
was significantly lower in patients treated with transarterial embolization (TAE)
than in those treated with transarterial chemotherapy (odds ratio, 0.72; 95% CI:
0.53, 0.98; P =.039) and that there is no evidence that transarterial
chemoembolization is more effective than TAE (odds ratio, 1.007; 95% CI: 0.79,
1.27; P =.95), which suggests that the addition of an anticancer drug did not
improve the therapeutic benefit.
CONCLUSION: In patients with unresectable HCC, chemoembolization significantly
improved the overall 2-year survival compared with nonactive treatment, but the
magnitude of the benefit is relatively small
The nephroprotective effect of sacubitril/valsartan in heart failure: insights from the real-life clinical setting
No full textSacubitril/valsartan represents the first agent in a new class of drugs developed for heart failure (HF) treatment and termed angiotensin receptor neprilysin (NEP) inhibitors (ARNIs). It is a fixed-dose combination compound containing molecular moieties of valsartan, an angiotensin-type I receptor (AT1)-inhibitor, and the NEP inhibitor sacubitril in a 1:1 molar ratio [1]. Sacubitril is a prodrug that, following oral administration, is rapidly metabolized to the biologically active molecule sacubitrilat. This inhibits the NEP, which is a ubiquitous endopeptidase that is responsible for the breakdown of many vasoactive peptides, including the biologically active natriuretic peptides (NPs), adrenomedullin, substance P, bradykinin, vasoactive intestinal polypeptide, calcitonin gene-related peptide, and enkephalins. Inhibition of NEP increases the levels of these substances, countering the neurohormonal overactivation that contributes to vasoconstriction, sodium retention, and maladaptive..
Self-blood pressure monitoring as a tool to increase hypertension awareness, adherence to antihypertensive therapy, and blood pressure control
No full textFor many years, casual blood pressure (BP) taken by a sphygmomanometer in the clinic or at the physician's office has been used as the standard method for diagnosing hypertension. Even if such measurement has been the cornerstone on which our understanding of the consequences of hypertension is based, there is a huge and very consistent body of evidence indicating that casual measurements of BP may provide a very unreliable index for the evaluation of hypertension because of their variability. The two alternative ways of measuring BP that have been most commonly used are measurements made at home by the patient himself (home or self‐BP monitoring—SBPM) and measurements by ambulatory blood pressure recorders. Results obtained by these methods have given closer correlation with a variety of measures of hypertensive end‐organ complications than casual or office BP. Furthermore, the prognostic studies indicate that BP measurements performed in “out‐of‐office” settings (using both home and ambulatory monitoring) are superior to office BP in predicting cardiovascular morbidity and mortality
Fractional Derivatives in Interval Analysis
No full textIn this paper, interval fractional derivatives are presented. We consider uncertainty in both the order and the argument of the fractional operator. The approach proposed takes advantage of the property of Fourier and Laplace transforms with respect to the translation operator, in order to first define integral transform of interval functions. Subsequently, the main interval fractional integrals and derivatives, such as the Riemann-Liouville, Caputo, and Riesz, are defined based on their properties with respect to integral transforms. Moreover, uncertain-but-bounded linear fractional dynamical systems, relevant in modeling fractional viscoelasticity, excited by zero-mean stationary Gaussian forces are considered. Within the interval analysis framework, either exact or approximate bounds of the variance of the stationary response are proposed, in case of interval stiffness or interval fractional damping, respectively
Non Linear Systems Driven by White Noise Processes and Handled by the Characteristic Function Equations
No full textHaemodynamics of primary aldosteronism associated with adrenocortical adenoma: Insights from bioimpedance cardiography measurements
No full textIn mid 1950s, Dr Jerome Conn described a patient with hypertension, and renal potassium wasting associated with adrenocortical adenoma and increased urinary excretion of a sodium-retaining hormone, initially termed electrocortin, which was subsequently shown to be aldosterone. This was the first full report of primary hyperaldosteronism associated with an aldosterone-producing adenoma (APA). It subsequently became apparent that similar abnormalities can occur in the absence of an adrenocortical tumor, and it is now recognized that the APA is just one of many subtypes of primary aldosteronism (PA)
The prognostic role of the cardio-ankle vascular index
No full textThe well‐performed meta‐analysis of Matsushita et al
represents an important contribution to the knowledge about the
clinical meaning of arterial stiffness parameters, suggesting that CAVI is associated positively with a slightly increased risk of CV
events, but not of total mortality. However, caution is needed in interpreting
these findings, due to the limited number of prospective
studies eligible for the meta‐analysis and the relatively low number
of subjects included, mostly living in Japan or China. Therefore, additional
studies, preferably with a prospective design and involving
participants also from non‐Asian countries, are required to better
define the prognostic role and the clinical utility of CAV
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