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Calculation errors in ocean-brightness coefficients in the Far Eastern are analyzed for two atmospheric correction algorithms (NIR and MUMM). The daylight measurements in different water types show that the main error component is systematic and has a simple dependence on the magnitudes of the coefficients. The causes of the error behavior are considered. The most probable explanation for the large errors in ocean-color parameters in the Far East is a high concentration of continental aerosol absorbing light. A comparison between satellite and in situ measurements at AERONET stations in the United States and South Korea has been made. It is shown the errors in these two regions differ by up to 10 times upon close water turbidity and relatively high aerosol optical-depth computation precision in the case of using the NIR correction of the atmospheric effect. [ABSTRACT FROM AUTHOR]

The results of applying a new method for the automatic calculation of ice drift based on the sequence of Advanced Microwave Scanning Radiometer (AMSR) images are considered. The method is analogous to the cross-correlation method but uses other ways to track template similarity and a new vector rejection criterion. Ice-concentration maps constructed using the ARTIST Sea Ice (ASI) algorithm (University of Bremen) based on data from 89 GHz spectral channels are used as images. While highly accurate at calculating ice drift, the new method has made it possible to reduce the template size, which makes it possible to obtain more detailed drift maps. Even in the case of a template linear size of 50-70 km, the ice-drift calculation accuracy is within 5 cm/s and method informativeness (the proportion of constructed vectors and vectors after rejection) is 60-70%. The method shows higher efficiency if the brightness mismatch is used as a measure of similarity between two templates instead of the correlation coefficient. [ABSTRACT FROM AUTHOR]

Tumor hypoxia is an important prognostic indicator for cancer therapy outcome. EF5 {2-(2nitro- 1[H]-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetamide} has been employed to measure tumor hypoxia in animals and humans using immunohistochemical methods. EF5 is a lipophilic molecule designed to have a very uniform biodistribution, a feature of obvious benefit for use in PET imaging. The present study represents the first demonstration of noninvasive PET imaging of rat tumors using fluorine-18 labeled EF5. Because of the small tumor size, partial volume effects may result in underestimation of concentration of the compound. Therefore, validation of the PET data was performed by gamma counting of the imaged tissue. The tumor models studied were the Morris 7777 (Q7) hepatoma (n = 5) and the 9L glioma (n = 2) grown subcutaneously in rats. Our previous studies have demonstrated that early passage 9L tumors are not severely hypoxic and that Q7 tumors are characterized by heterogeneous regions of tumor hypoxia (i.e., Q7 tumors are usually more hypoxic than early passage 9L tumors). The seven rats were imaged in the HEAD Penn-PET scanner at various time points after administration of 50-100 µCi [sup 18]F-EF5 in 30 mg/kg carrier nonradioactive EF5. The carrier was used to ensure drug biodistribution comparable to prior studies using immunohistochemical methods. [sup 18]F-EF5 was excreted primarily via the urinary system. Images obtained 10 min following drug admin- istration demonstrated that the EF5 distributed evenly to all organ systems, including brain. Later images showed increased uptake in most Q7 tumors compared with muscle. Liver uptake remained relatively constant over the same time periods. Tumor to muscle ratios ranged from 0.82 to 1.73 (based on PET images at 120 min post injection) and 1.47 to 2.95 (based on gamma counts at ∼180 min post injection). Tumors were easily visible by 60 min post injection when the final tumor to muscle ratios... [ABSTRACT FROM AUTHOR]

The molecular mechanism of the disturbance of brain development caused by phenylketonuria remains mostly unknown. We have studied three molecular markers that reflect the development of neurons, glia and the extracellular matrix of the postnatal rat brain in an animal model of hyperphenylalaninemia, in order to elucidate the possible mechanism by which increased phenylalanine influences brain development. The content of NCAM, GFAP and hyaluronate-binding activity were compared in cerebellum and telencephalon of normal rats and those subjected to high phenylalanine. No statistically significant changes were found in telencephalon when experimental animals were compared to controls. In the hyperphenylalaninemic cerebellum, the developmental dynamic of NCAM content (represented by two peaks at about postnatal days 5 and 22 during normal development) is dramatically altered. The GFAP content in the cerebellum of treated rats exceeded those in controls significantly during late developmental stages (postnatal days 28-35). Hyaluronate-binding activity in the extracellular protein fraction from treated rat cerebellum was increased compared to normal rat at the early stages of development only (postnatal day 7). These results suggest that high serum phenylalanine may lead to permanent brain dysfunction through a disturbance of a wide range of developmental events.