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The article presents information on a spatio-temporal model used to examine the annual variability in Antarctic sea ice formation. A brief overview is given on the complexity of the temporal variability of polar sea ice and its close association to global climate. It notes that the amount of sea ice over an area can have a significant effect on the energies transferred between the atmosphere and the ocean. It demonstrates the method using sea ice concentration images derived from Earth-orbiting satellites that span several decades. It reveals that the growth and melt of Antarctic sea ice is modeled using a simple two parameter spatial nearest neighbor process that treats ice and water as two species competing for territory.

On considère une classe de méthodes du minimum de distance basées sur des transformations expérimentales. Cette classe contient la méthode du khi-deux minimum, la méthode K-L pour fonctions caractéristiques expérimentales et la méthode analogue pour fonctions génératrices des moments expérimentales. On établit plusieurs propriétés asymptotiques des estimateurs basés sur les méthodes du minimum de distance et on construit des statistiques pour tests d'ajustement. On formule en outre un analogue général de la statistique de Rao-Robson. [ABSTRACT FROM AUTHOR]

The immunological and biological activities of growth hormone (GH) and prolactin P1(L) in the pituitary gland and serum of the squirrel monkey (Sairrtiri boliviensis boliuiensis) have been studied. Proteins in pituitary homogenates were solubilized in 1% SDS, electrophoresed on 12% polyacrylamide gels, and transferred to nitrocellulose. Squirrel monkey GH and PRL were identified by immunoblotting with anti-human GH anti-bodies and a monoclonal antibody to ovine PRL, 6FI1, respectively. Squirrel monkey GH appeared predominantly as two proteins of apparent molecular weight 22 and 20 kD, corresponding to native and variant forms of human GH. Squirrel monkey PRL appeared as two proteins of apparent molecular weight 24 and 26.5 kD, which co-migrated with native and glycosylated forms of ovine PRL. The cross-reactivity of neutralizing antibodies to human GH and PRL with squirrel monkey GH and PRL were examined using the Nb2 lymphoma bioassay. One of three monoclonal antibodies to human GH (2A1) neutralized squirrel monkey GH with an apparent affinity for squirrel monkey GH (IC50 = 70 ng IgG/ml) which was fourfold lower than for human GH (IC50 15 ng IgG/ml). Both polyclonal [AR38-5(1)] and monoclonal (9C3) antibodies to human PRL, although their affinities for squirrel monkey PRL were four- and twentyfold lower than for human PRL. The activities of antibodies 2A1 and 9C3 on GH and PRL in squirrel monkey serum were also examined by the Nb2 bioassay. The anti-gluco- corticoid RU486 was used in all incubations with squirrel monkey serum to eliminate the effect of high glucocorticoid levels on Nb2 cell growth. The mitogenic activity of squirrel monkey serum in the Nb2 assay was completely eliminated in the presence of 2A1 and 9C3. This study represents the first description of the biochemistry of GH and PRL in the squirrel monkey. [ABSTRACT FROM AUTHOR]

Zooxanthellate cnidarians are trophically complex, relying on both autotrophy and heterotrophy. Although several aspects of heterotrophy have been studied in these organisms, information linking prey capture with digestion is still missing. We used prey-specific PCR-based tools to assess feeding and prey digestion of two zooxanthellate cnidarians - the tropical sea anemone Aiptasia sp. and the scleractinian coral Oculina arbuscula. Prey DNA disappeared rapidly for the initial 1-3 days, whereas complete digestion of prey DNA required up to 10 days in O. arbuscula and 5 or 6 days in Aiptasia sp. depending on prey species. These digestion times are considerably longer than previously reported from microscopy-based examination of zooxanthellate cnidarians and prey DNA breakdown in other marine invertebrates, but similar to prey DNA breakdown reported from terrestrial invertebrates such as heteroptera and spiders. Deprivation of external prey induced increased digestion rates during the first days after feeding in O. arbuscula, but after 6 days of digestion, there were no differences in the remaining prey levels in fed and unfed corals. This study indicates that prey digestion by symbiotic corals may be slower than previously reported and varies with the type of prey, the cnidarian species and its feeding history. These observations have important implications for bioenergetic and trophodynamic studies on zooxanthellate cnidarians. [ABSTRACT FROM AUTHOR]

Determination of squirrel monkey prolactin by immunoassay has been hampered by the lack of antiserum specific to prolactin from this species. As an alternate method, we have investigated whether the Nb2 lymphoma bioassay could be adapted for routine measurement of the lactogenic activity of samples of squirrel monkey serum. The growth of the Nb2 cells is absolutely dependent on the presence of lactogens in the culture medium. The cells were maintained in Fisher's medium supplemented with 10% horse serum, 10% fetal calf serum (FCS), and 10 -4 M β-mercaptoethanol. For each assay, the cells were plated at an initial density of 1 × 10 5 cells/ml in 22-mm 12-well dishes in the above medium, but devoid of FCS. Serum samples were heated to 56°C for 20 minutes to abolish the unusually high cytolytic complement activity of squirrel monkey serum and were incubated for 72 hours with Nb2 cells at serial dilutions from 1/40 to 1/2,560. Growth curves were generated with pooled samples of squirrel monkey serum, and the level of lactogenic activity was estimated using a calibration growth curve generated with known concentrations of purified rhesus monkey prolactin standard. We have found that the Nb2 lymphoma bioassay provides a sensitive and adaptable means for determination of lactogenic activity in the serum of the squirrel monkey., (Copyright © 1989 Wiley‐Liss, Inc., A Wiley Company.)

The emergence of a near-haploid clone of cells in blast phase chronic myelogenous leukemia is an unusual event. We report such a case and review eight other cases described in the English literature. The significance of the substantial loss of genetic material is discussed as is the phenotypic and genotypic heterogeneity observed in this group of patients.