SUMMARYThrips fly at a chord-based Reynolds number of approximately 10 using bristled rather than solid wings. We tested two dynamically scaled mechanical models of a thrips forewing. In the bristled design, cylindrical rods model the bristles of the forewing; the solid design was identical to the bristled one in shape, but the spaces between the `bristles' were filled in by membrane. We studied four different motion patterns: (i) forward motion at a constant forward velocity, (ii) forward motion at a translational acceleration, (iii) rotational motion at a constant angular velocity and (iv)rotational motion at an angular acceleration. Fluid-dynamic forces acting on the bristled model wing were a little smaller than those on the solid wing. Therefore, the bristled wing of a thrips cannot be explained in terms of increased fluid-dynamic forces.

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The pathogenesis and etiology of Kawasaki disease are unknown, but some studies suggest increased genetic susceptibility. The case is presented of an infant with Kawasaki disease whose father suffered from the same illness 21 years previously. The A, B and C loci of the HLA antigens were examined.

A 13 year old girl with carpopedal spasm is presented. Investigation values showed hypomagnesemia and hypokalemia. Her younger brother and sister demonstrated the same biochemical abnormalities w i t h o u t any symptoms. Their Urinary excretion of magnesium and potassium were inappropriately high compared with their serum levels. Treatment with oral magnesium sulfate failed to correct the abnormalities, but serum levels of magnesium and potassium were just below the lower limits. This familial disease may represent congenital renal wasting of magnesium and potassium.