Partial Atrioventricular Canal Defect: An Educational Ultrasound Image.

Atrioventricular canal defect results from an abnormal or inadequate fusion of the superior and inferior endocardial cushions. Both the complete and partial types of the defect are associated with the ostium primum defect in the lowermost portion of the atrial septum, left ventricular outflow narrowing and the atrioventricular valve abnormalities. The clinical diagnosis of partial atrioventricular canal defect can be confirmed by cardiac ultrasound. The aim of this paper is to preset an educational ultrasound image of partial atrioventricular canal defect.

Partial atrioventricular canal defect: An educational ultrasound image

Atrioventricular canal defect results from an abnormal or inadequate fusion of the superior and inferior endocardial cushions. Both the complete and partial types of the defect are associated with the ostium primum defect in the lowermost portion of the atrial septum, left ventricular outflow narrowing and the atrioventricular valve abnormalities. The clinical diagnosis of partial atrioventricular canal defect can be confirmed by cardiac ultrasound. The aim of this paper is to preset an educational ultrasound image of partial atrioventricular canal defect.

Surgical anatomy of the posterior ends of the middle and inferior turbinates

Background: Preservation of structure and reestablishment of function is the guiding principle during an endoscopic intervention. Especially, when a partial middle turbinectomy is unavoidable, middle turbinate can lose its stability. Variations of middle turbinate like severe anterior bulging, posterior protrusion beyond the inferior turbinate and the larger size than inferior turbinate have significant impact on its stability. Aim: To study surgical anatomy of the middle and inferior turbinates. Method: The distances and angles between the limen nasi and posterior ends of the middle and inferior turbinates were studied in 100 hemisected adult Indian cadaveric heads. Results: The mean angles between the line passing through the lowermost portion of limen nasi and posterior ends of middle turbinate and inferior turbinate respectively are bl was 19.87° and b2 was 10.57°. The mean distance between the lowermost portion of limen nasi and posterior ends of middle turbinate and of inferior turbinate were xi is 55.88 ± 3.61 mm and x2 was 52.69 ± 3.57 nnn.The mean distances between the lowermost portion of limen nasi and the perpendicular from the posterior ends of middle turbinate and inferior turbinate to the hard palate were yl= 52.47 ± 3.33 mm (range: 44.16 to 59.92 mm) and y2= 51.75 ± 3.45 mm (range 43.32 to 61.22 mm) respectively. In 52% cases middle turbinate extends more posterior with respect to inferior turbinate i.e.M > I and in 48% cases inferior turbinate extends more posterior with respect to middle turbinate of M < I. Conclusion: The documentation of these parameters and the related variations is likely to be useful for the endoscopic surgeons.

The Alpine tectonic evolution of the Danube Basin and its northern periphery (southwestern Slovakia)

The tectonic evolution of the pre-Cenozoic basement, as well as the Cenozoic structures within the Danube Basin (DB) and its northern periphery are presented. The lowermost portion of the pre-Cenozoic basement is formed by the Tatricum Unit which was tectonically affected by the subduction of the Vahicum / Penninicum distal continental crust during the Turonian. Tectonically disintegrated Tatricum overlaid the post-Turonian to Lower Eocene sediments that are considered a part of the Vahicum wedge-top basin. These sediments are overthrust with the Fatricum and Hronicum cover nappes. The Danube Basin Transversal Fault (DBTF) oriented along a NW–SE course divided the pre-Neogene basement of the DB into two parts. The southwestern part of the DB pre-Neogene basement is eroded to the crystalline complexes while the Palaeogene and Mesozoic sediments are overlaid by the Neogene deposits on the northeastern side of the DBTF. The DBTF was activated as a dextral fault during the Late Oligocene – Earliest Miocene. During the Early Miocene (Karpatian – Early Badenian) it was active as a normal fault. In the Middle – Late Miocene the dominant tectonic regime with NW – SE oriented extension led to the disintegration of the elevated pre-Neogene basement under the simple and pure shear mechanisms into several NE – SW oriented horst and graben structures with successive subsidence generally from west to east. The extensional tectonics with the perpendicular NE – SW orientation of the Shminpersists in the Danube Basin from the ?Middle Pleistocene to the present.

A Seismic Reflection Model of the Crust near Edmonton, Alberta

Reflection profiles shot about 10 km north of the Edmonton seismic observatory (EDM) indicate dips within the crust of 15 to 20° southeast, with a prominent reflecting horizon at 20 km apparently being offset 4 km by a fault. The average velocity in the crust to this horizon is 6.3–6.4 km/s. Deeper reflections tentatively correlated with the "Riel" discontinuity mapped in southern Alberta indicate a velocity in a second layer of 6.5 km/s to a depth of 32 km, with the base of the crust being essentially horizontal at 35.5 km. The lowermost portion of the crust appears to be significantly thinner here than in southern Alberta, although the general features of the seismic records appear similar in both locations.Velocities are determined by a modified version of the velocity spectrum technique, which does not require common depth point data.