Description of spatial patterns of radionuclide deposition by lognormal distribution and hot spots.

Spatial distributions of activity density (kBq/m(2)) and activity concentration (Bq/kg) are studied on sites with non-cultivated soils. Fitting datasets with lognormal, Weibull and normal distributions with sampling size n ≥ 60 showed that radionuclide deposition ((90)Sr, (137)Cs, (238)Pu, (239+240)Pu, (241)Am) due to Chernobyl fallout no more than in 10% of cases are described by Weibull distribution, and in the rest of the cases--by lognormal distribution. However asymptotics of "righthand tail" of empirical (sample) distribution quite often differs from the right-hand tail asymptotics of lognormal distribution.

[Radioanatomy of cerebral perfusion in single-photon emission-computed tomography using 99mTc-labelled amines].

A study was made of the cerebral hemodynamics by assessing the distribution in single-photon emission computerized tomography with 99mTc-hexamethyl-propyleneminoxyne in health using a Testascan in 9 standard slices. The whole set of tomographic slices was conventionally divided into 3 levels. For better orientation in gamma-tomographic images, pictures were presented where in addition to scintigrams a morphological scheme of the cerebral parts with the marked parts perfused by cerebral arteries, was given.

[Interdependence of mycelial dehydrogenase activity in Streptomyces aureofaciens and its capacity for tetracycline biosynthesis].

The maximum dehydrogenase (oxidation-reduction) activity of the vegetative inoculum of S. aureofaciens is the criterion of its availability for transfer to the fermentation medium. The activity is determined by the rate of the methylen blue reduction and the growth characteristics of the seed culture.