No abstract

We describe a patient with a right coronary arteriovenous fistula in whom magnetic resonance imaging (MRI) was useful in establishing the diagnosis. In a 36-year-old woman, T1 spin echo MRI demonstrated a massively dilated coronary arteriovenous fistula connecting the right coronary artery to the right atrium. The cine field echo technique showed a continuous shunt flow within the fistula as documented by the flow void throughout the cardiac cycle. These findings were confirmed by cardiac catheterization. We conclude that MRI is useful not only in detecting a coronary arteriovenous fistula but also in identifying its origin and the drainage site.

No abstract

This study examined the behavioral characteristics of juvenile Japanese surf clam Pseudocardium sachalinensis in response to sand erosion and deposition under laboratory conditions, then estimated the fluid conditions critical to wash the clams out of the sand. The juveniles started burrowing down ward into sand when their burying depth decreased to less than 1.5 times the shell length due to erosion , and moving upward when the depth increased to more than 2.5 times the shell length due to deposition of sand. Burrowing and climbing actions of the juvenile continued until the depth reached 1.7-2.1 times the shell length once again. The burrowing and climbing speeds were about 1.8 times higher than the speed of erosion or deposition of sand. It was concluded that the juveniles would maintain their po sition actively in order to avoid being washed out or buried too deeply by adapting their behavior to the dynamic conditions of sand movement. The juveniles were washed out of the sand when the erosion speed exceeded 3.5 mm/min, and such erosion occurred when oscillatory water flow speeds over a sandy bottom with median particle diameter of 0.3 mm exceeded more than 45 and 55 cm/s at periods of 4 s and 8 s, respectively.

BreedingSeason of the Sunray Surf Clam Mactra chinensis in Tomakomai,