14 research outputs found

    Mediterranean winter rainfall in phase with African monsoons during the past 1.36 million years

    Get PDF
    Mediterranean climates are characterized by strong seasonal contrasts between dry summers and wet winters. Changes in winter rainfall are critical for regional socioeconomic development, but are difficult to simulate accurately1 and reconstruct on Quaternary timescales. This is partly because regional hydroclimate records that cover multiple glacial–interglacial cycles2,3 with different orbital geometries, global ice volume and atmospheric greenhouse gas concentrations are scarce. Moreover, the underlying mechanisms of change and their persistence remain unexplored. Here we show that, over the past 1.36 million years, wet winters in the northcentral Mediterranean tend to occur with high contrasts in local, seasonal insolation and a vigorous African summer monsoon. Our proxy time series from Lake Ohrid on the Balkan Peninsula, together with a 784,000-year transient climate model hindcast, suggest that increased sea surface temperatures amplify local cyclone development and refuel North Atlantic low-pressure systems that enter the Mediterranean during phases of low continental ice volume and high concentrations of atmospheric greenhouse gases. A comparison with modern reanalysis data shows that current drivers of the amount of rainfall in the Mediterranean share some similarities to those that drive the reconstructed increases in precipitation. Our data cover multiple insolation maxima and are therefore an important benchmark for testing climate model performance

    EVAR: Benefits of CEUS for monitoring stent-graft status

    No full text
    Abstract Endo vascular aortic repair [EVAR] is performed with low peri-operative morbidity and mortality rate and short hospital stay. However, EVAR needs a close and lifelong imagining surveillance for a timely detection of possible complications including endoleaks, graft migration, fractures, and enlargement of aneurysm sac size with eventual rupture. Contrast enhanced computed tomography [CTA] is actually considered the gold-standard in EVAR follow-up, but it is accompanied with radiation burden and renal injury due to the use of contrast media. In the last two decades several studies have shown the role of contrast enhanced ultrasound [CEUS] in post-EVAR surveillance, with very good diagnostic performance, absence of renal impairment, and no radiation, accompanied by low costs, in comparison with CTA. In numerous prospective studies and meta-analyses the detection and characterization of endoleaks with CEUS is comparable to that of CTA imaging. Nowadays, in the EVAR surveillance novel strategies which involve CEUS with a central role, are suggested by several authors and applied in many institutions. In this review article we will present a comprehensive overview and analyses of the literature on the CEUS state-of-art imagining of EVAR follow-up, with its technique, findings, diagnostic accuracy, and its role in the follow up program
    corecore