Acoustic sources based on electrical discharge, commonly called sparker sources, are employed in surveys for high-resolution marine stratigraphy. In this work, a new seismic sparker-type transducer has been designed, built and tested to obtain specific characteristics: low cost, small size (50x50x15 cm(3)), high resolving power, perfect symmetry of the acoustic beam emitted, and high directivity. This source can, thus, also be used in shallow water, to delineate the first sedimentary layers. First, an analysis of the determined experimental radiation pattern, signal to noise, and wavelet shape is presented. The radiation pattern is subsequently compared to the theoretical one. Lastly, comparative tests with traditional sparker sources and with the boomer source showed the validity of the performance of the new source.

High-frequency coastal radars (HFRs) have proved to be excellent tools for monitoring coastal circulation, providing synoptic, high spatial and temporal resolution surface current data in real time. They may also give detailed information on the surface wave field of coastal areas. An HFR has been operating in the Gulf of Naples (south-eastern Tyrrhenian Sea) since 2004. In this paper we show the results of their utilisation in the study of the Gulf dynamics and sea state, with a focus on potential applications in the context of operational oceanography.

Cardiovascular diseases are commonly related to classical risk factors, but other risk markers have been identified, including homocysteine. Homocysteine is a sulphurated amino acid which derives from methionine. The causes of hyperhomocysteinemia are multifactorial, such as genetic defects, pathophysiological conditions, lifestyle and drugs-related. Hyperhomocysteinemia favors atherothrombosis through endothelial dysfunction, enhancement of inflammation and thrombophilic profile. A number of clinical and laboratory trials exist regarding the association between homocysteine levels and an increased risk of cardiovascular disease. However, the lack of homogeneity in the data, together with the high number of factors capable of influencing homocysteine plasma levels, and the disappointing results of therapeutic trials do not permit us at present to consider homocysteine as an independent and major risk factor for cardiovascular disease.

Because of its antiarrhythmic properties,1 parenteral magnesium sulfate has been widely used in the last decades in treating several supraventricular or ventricular arrhythmias2,3 even in patients with cardiovascular diseases. Recently, intravenous magnesium sulfate has proved effective in treating arrhythmias associated with acute myocardial infarction4 and long QT syndrome.5 However, a systematic evaluation of its effects on cardiovascular hemodynamics has not been reported. Recent experimental6 and clinical7 observations have suggested that magnesium sulfate may exert a vasodilator effect on human coronary arteries. The present study investigates the effects of magnesium sulfate infusion on coronary and systemic hemodynamics in humans.