Study of material changes of SINQ target rods after long-term exposure by neutron radiography methods.

This paper describes the results of non-destructive investigations by indirect neutron radiography methods obtained at the facility NEUTRA [Nondestruct. Testing Eval. 16 (2000b) 203], spallation neutron source SINQ [Operating experience and development projects at SINQ, PSI Report 98-04, ISSN 1019-0643]. Target rods from the second SINQ metal target were removed after 6 Ah of proton beam exposure and studied under well-shielded conditions. No real damage was found at one of the 11 observed rods and one tube. However, hydrogen accumulation could be identified inside the zircaloy rods and the steel rods as well. Whereas the hydrogen has a homogenous distribution in Zr (with the peak value near the centre of the applied beam), the steel samples show clusters of hydrogen near the edge of the Zr cladding. Lead (in steel cladding) was found modified by accumulations of spallation products, mainly mercury. In the radiography images, a depression of the neutron field was observed due to the absorption by mercury. The applied method with Dy and In as neutron converters and imaging plates [Nucl. Instrum. Methods 377 (1996) 119] as secondary detectors seems to be optimal for such kind of investigations, especially when quantitative considerations have to be made.

Polyunsaturation of subcutaneous fat and concentration of serum lipids of Israeli Beduin Arabs.

In 55 Israeli Beduin Arabs the ratio of polyunsaturated to saturated fatty acids in subcutaneous fat (which reflects the degree of unsaturation of dietary fat) and serum cholesterol and triglyceride concentrations were all significantly lower in men and women leading the typical seminomadic Beduin life than in men doing western-type work and in housewives of a fixed Beduin settlement. The values were 0.76, and 159 and 72 mg/dl, respectively, compared with 0.93, 187 and 108; P less than 0.001, less than 0.01 and less than 0.02, respectively. In the group as a whole there was a paradoxically positive correlation between P/S ratio and cholesterol (r = 0.37, Pr = 0.025) and P/S ratio and triglycerides (r = 0.46, Pr less than 0.01). The expected cholesterol-lowering effect of the polyunsaturated Israeli diet (P/S ratio about 1.0) was apparently swamped by other factors, dietary and/or non-dietary, involved in acculturation to a western life style of Beduin, among whom coronary heart disease has only recently begun to appear.

Acute anterior myelitis complicating West Nile fever.

A healthy young man developed acute anterior myelitis resembling the "polio syndrome." He had visited an area (the Gulf of Suez) in which West Nile fever is endemic prior to his illness. The course of his febrile illness, the spinal fluid findings, and complement fixation antibody titers established the diagnosis of West Nile fever. Meningoencephalitis is a serious, and previously the only known, complication of this usually benign febrile illness. This is the first report, to our knowledge, of another neurological complication, namely acute anterior myelitis.