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Abstract A giant mass-transport complex was recently discovered in the eastern Arabian Sea, exceeding in volume all but one other known complex on passive margins worldwide. The complex, named the Nataraja Slide, was drilled by International Ocean Discovery Program (IODP) Expedition 355 in two locations where it is ∼300 m (Site U1456) and ∼200 m thick (Site U1457). The top of this mass-transport complex is defined by the presence of both reworked microfossil assemblages and deformation structures, such as folding and faulting. The deposit consists of two main phases of mass wasting, each consisting of smaller pulses, with generally fining-upward cycles, all emplaced just prior to 10.8 Ma based on biostratigraphy. The base of the deposit at each site is composed largely of matrix-supported carbonate breccia that is interpreted as the product of debris-flows. In the first phase, these breccias alternate with well-sorted calcarenites deposited from a high-energy current, coherent limestone blocks that are derived directly from the Indian continental margin, and a few clastic mudstone beds. In the second phase, at the top of the deposit, muddy turbidites dominate and become increasingly more siliciclastic. At Site U1456, where both phases are seen, a 20-m section of hemipelagic mudstone is present, overlain by a ∼40-m-thick section of calcarenite and slumped interbedded mud and siltstone. Bulk sediment geochemistry, heavy-mineral analysis, clay mineralogy, isotope geochemistry, and detrital zircon U-Pb ages constrain the provenance of the clastic, muddy material to being reworked, Indus-derived sediment, with input from western Indian rivers (e.g., Narmada and Tapti rivers), and some material from the Deccan Traps. The carbonate blocks found within the breccias are shallow-water limestones from the outer western Indian continental shelf, which was oversteepened from enhanced clastic sediment delivery during the mid-Miocene. The final emplacement of the material was likely related to seismicity as there are modern intraplate earthquakes close to the source of the slide. Although we hypothesize that this area is at low risk for future mass wasting events, it should be noted that other oversteepened continental margins around the world could be at risk for mass failure as large as the Nataraja Slide.

Objective: Depressed cardiac function after aortoventriculoplasty is well known during the postoperative period. Little data exist concerning the long-term follow-up. The aim of this study is to determine whether septal incision has any permanent effect on the left ventricle function. Methods: From 1988 to 2002, 45 patients received aortic mechanical prosthesis. These patients were divided into two groups. Group A consisted of 26 patients 5–18 years old, who underwent simple aortic valve replacement. Group B consisted of 19 patients 4–20 years old, who underwent the Konno procedure. Systolic and diastolic functions of the left ventricle were analyzed using echocardiography. For the systolic function, the following parameters were assessed: pressure gradient between left ventricle and ascending aorta, shortening and ejection fraction of the left ventricle. For the diastolic function, left ventricle-filling parameters were assessed: ratio of early to late filling velocity, deceleration slope of the early filling velocity and left ventricular isovolumetric relaxation time. Furthermore the percentage fraction of the aortic valve index (AOVI%) was calculated and compared between these two groups. Results: After the surgery in group A, AOVI% dropped from 110±21 to 98±11%, while in group B it increased from 82±16 to 114±11%. As a result a higher residual pressure gradient across the aortic valve was noted in group A: 21.26±15 as compared to 11.17±5 mmHg in group B. A mean pressure above 30 mmHg appeared in group A 2 years after the surgery, while in group B this was obtained after 6 years. As for the diastolic function no significant difference was noted between these two groups. Overall there was one late death in group A, and in group B two early deaths, two reoperations because of excessive drainage and in two patients permanent pacemakers had to be implanted. Conclusions: Improvement of the systolic function after the surgery was noted in both groups. In patients with low AOVI%, postsurgical pressure gradient, either residual or recurrent, appeared during the follow-up. As for the septal incision, it may have some transient effects on the left ventricle function in the postoperative period, but no permanent sequelae were observed in the long-term follow-up. [Copyright &y& Elsevier]