María J. González

Exceptional sets and Hilbert–Schmidt composition operators

It is shown that an analytic map phi of the unit disk into itself inducing a Hilbert-Schmidt composition operator on the Dirichlet space has the property that the set E-phi = {e(i0)is an element ofpartial derivativeD : \phi(e(10))\ = 1 has zero logarithmic capacity. We also show that this is no longer true for compact composition operators on the Dirichlet space. Moreover, such a condition is not even satisfied by Hilbert-Schmidt composition operators on the Hardy space.

Randomized comparison of long-term Losartan vs propranolol in lowering portal pressure in cirrhosis

BACKGROUND & AIMS It has been suggested that losartan, an angiotensin II (A-II) type 1 receptor blocker, may have a pronounced portal pressure reducing effect, far greater than that of propranolol. This randomized controlled trial compared the hemodynamic and renal effects of continued 6-week administration of losartan (n = 25) vs. propranolol (n = 15) in portal hypertensive patients with cirrhosis treated endoscopically after a variceal bleeding episode. METHODS Hepatic venous pressure gradient (HVPG), systemic hemodynamics, renal function, and vasoactive factors were measured before and at 6 weeks of treatment. RESULTS Losartan did not reduce HVPG (-2% +/- 12%, NS) but significantly decreased mean arterial pressure (MAP, -8% +/- 10%, P = 0.001). On the contrary, propranolol significantly reduced HVPG (-10% +/- 11%, P = 0.003) and cardiac output (-16% +/- 12%, P = 0.001) but did not modify MAP (2.5% +/- 10%, NS). Losartan increased A-II levels, reduced aldosterone, and decreased glomerular filtration rate (GFR) in Child B patients. Propranolol did not modify renal function. Adverse events related to therapy were mild and similar in both groups. CONCLUSIONS Unlike propranolol, long-term losartan administration does not significantly reduce HVPG in patients with cirrhosis treated after a variceal bleeding episode, and it caused hypotension and reduced GFR in patients with moderate liver failure. Therefore, losartan is not an alternative to propranolol in preventing variceal rebleeding.

Multiplicative Square Functions

We study regularity properties of a positive measure in the euclidean space in terms of two square functions which are the multiplicative analogues of the usual martingale square function and of the Lusin area function of a harmonic function. The size of ...

Composition operators on Hardy spaces on Lavrentiev domains

In this note, composition operators on Bergman spaces of a simply connected domain are studied characterizing boundedness and compactness of such operators whenever the domain is Lavrentiev.

Calcium dobesilate versus purified flavonoid fraction of diosmin in the treatment of hemorrhoidal crises: a randomized, controlled study with an initial double-blind, double-dummy period

Abstract Background: Calcium dobesilate and purified, micronized flavonoid fraction of diosmin, 2 products used in the treatment of chronic venous insufficiency in the lower limbs, have been shown in open-label, placebo-controlled studies to improve symptoms of acute hemorrhoidal episodes. Objective: This study was performed to compare the efficacy and tolerability of calcium dobesilate and purified, micronized flavonoid fraction of diosmin in the treatment of hemorrhoidal crisis. Methods: Patients with a diagnosis of hemorrhoidal crisis were randomized to receive 1 of 2 treatments: calcium dobesilate one 500-mg capsule TID for ≥4 weeks or purified, micronized flavonoid fraction of diosmin two 500-mg capsules TID for ≥4 weeks. For the first 10 days, patients in both groups were given dummy capsules or tablets to maintain the double-blind provision. Patients underwent physical examination at baseline and after 2 days, 8 days, and 4 weeks of treatment. The following symptoms were assessed using a 4-point scale (0 = absent; 1=mild; 2=moderate; 3=severe): pain, discharge, bleeding, edema, inflammation, pruritus, and anal pressure. Results: A total of 51 patients were treated; 25 received calcium dobesilate and 26 received micronized flavonoid fraction of diosmin. In both treatment groups, significant improvement was observed in 6 of 7 evaluated symptoms after 2 days of treatment ( P Conclusion: Calcium dobesilate 1.5 g/d and purified, micronized flavonoid fraction of diosmin 3 g/d were equally effective and well tolerated in the treatment of signs and symptoms associated with hemorrhoidal crisis.

Evaluation of the effectiveness and tolerability of controlled-release diclofenac-potassium versus immediate-release diclofenac-potassium in the treatment of knee osteoarthritis

UNLABELLED Abstract. BACKGROUND A controlled-release (CR) form of diclofenac-potassium has been developed, which delivers 100 mg over the course of 24 hours. This formulation is administered QD and provides steady plasmatic levels of the drug. OBJECTIVE The aim of this study was to compare the effectiveness and tolerability of CR diclofenac-potassium versus the immediate-release (IR) formulation, when used for treatment of pain in patients with knee osteoarthritis. METHODS This prospective, randomized, double-blind, comparative, multi-center, parallel-group study was conducted in male and female patients who had been previously diagnosed with knee osteoarthritis. Inclusion criteria included knee joint pain and ≥3 of the following: age >50 years, morning rigidity lasting <30 minutes, crackling in the joint, pain with applied pressure to the bones, bone hypertrophy, absence of articular heat, and a radiology status of I to III on the Kellgren-Lawrence scale. Patients were randomly divided into 1 of 2 equal-sized groups: 1 group received diclofenac-potassium IR 50 mg BID for 30 days and 1 group received diclofenac-potassium CR 100 mg QD for 30 days. Patients were assessed at baseline and again at 15 and 30 days after initiation of treatment with a physical examination, pain measurement via 100-mm visual analog scale (VAS), and Western Ontario McMaster (WOMAC) osteoarthritis index questionnaire. Adverse events (AEs) were assessed by direct interrogation, hematology controls, blood chemistry, hepatic tests, coagulation tests, and urine tests performed on patients before treatment initiation and on day 30. RESULTS Sixty-five patients were screened and 62 patients (mean [SD]age, 61.8 [8.9] years; mean [SD] weight, 71.3 [12.4] kg; female sex, 55 [88.9%]) were included in the study; each study group had 31 patients. After 30 days, both products were equally effective in relieving pain, as measured by VAS (IR, 17.3 vs CR, 21.6; P = NS), and changes in the WOMAC score (IR, 14.5 vs CR, 19.2; P = NS). Significantly more patients in the IR group reported feeling better after 30 days than in the CR group (94% vs 76%; P = 0.002) and, according to the physicians opinion, significantly more patients treated with diclofenac-potassium IR felt better (97% vs 83%; P = 0.03). Significantly more patients in the IR group required rescue medication than those in the CR group (36% vs 26%; P = 0.03). In the CR group, 7 patients experienced AEs: 6 were gastrointestinal (ie, pyrosis, epigastralgia, dyspepsia) and 1 patient experienced increased arterial pressure. One patient from this group discontinued treatment due to a lack of efficacy. In the IR group, 6 patients experienced AEs (ie, tachycardia, epigastralgia, and pyrosis). One patient discontinued because of AEs, and 3 withdrew due to a lack of efficacy. CONCLUSION Based on the results from this small study in a Venezuelan population, both IR and CR formulations of diclofenac-potassium have similar effectiveness and tolerability profiles.

Crustal Deformation Models and Time-Frequency Analysis of GPS Data from Deception Island Volcano (South Shetland Islands, Antarctica)

We have applied wavelet techniques to analyze GPS time-series data from REGID geodetic network, deployed at Deception Island Volcano (South Shetland Islands, Antarctica). In the present analysis wavelets are used to detect periodic components and to filter the data. The high frequency components can be associated to the orbital period of the satellites and to local tidal effects, whereas the medium frequencies seem to be related to the weather cycle. The wavelet filtering procedure is based on the SURE estimator, and a considerable reduction in noise is achieved, particularly in the Up component, whose deviation is reduced down to the deviation of the horizontal components before the denoising. An estimation of the displacements in the network for the period 2001/02 – 2005/06 is also included.

A new data analysis technique in the study of mutual event lightcurves

The purpose of this paper is to develop a new methodology for analyzing astronomical data, in particular, one of the light curves obtained in the PHEMU campaign in 1997, where the mutual phenomena between Jupiter and its satellites were observed from the Earth due to the coincidence of the equatorial plane of Jupiter and the orbit plane of the Earth. The more specific aim of this study is to determine the times of the beginning and the end of the phenomena, and the moment when the recorded light flux was at a minimum. The techniques we applied were based on the wavelet theory, which allows us to study a signal from its approximations and details at different scales. Before applying the designed algorithm to our experimental data, we considered a synthetic light curve in order to check the reliability of our method. It should be mentioned that the results are not relevant from the astronomical point of view, since no corrections for albedo or illumination were applied to the recorded data.

Radial growth of solutions to the poisson equation

We establish a radial growth estimate of the type of the iterated law of the logarithm for solutions to the Poisson equation in the unit ball.

Composition operators on Bergman spaces on Lavrentiev domains

In this note, composition operators on Bergman spaces of a simply connected domain are studied characterizing boundedness and compactness of such operators whenever the domain is Lavrentiev. §Dedicated to Professor Peter L. Duren on the occasion of his 70th birthday.