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Enrichment of the hermatypic Red Sea coral Stylophora pistillata with dissolved inorganic nitrogen, inorganic nitrogen + phosphorus, and feed­ing on Artemia , all led to increases in areal pigmentation in comparison with control colonies. These increases, unlike photoadaptive ones, resulted from growth in cell numbers ranging from × 2.75 in the Artemia -fed to × 4.85 in the N + P-enriched corals. The treated corals absorbed 51-85% of incident light, whereas the controls absorbed only 33%. Areal photosynthesis increased with treatment, although to a lesser degree than absorptivity. This difference resulted in reduced photosynthetic effici­encies in the treated colonies. Photosynthetic rates, calculated on a percell basis, were inversely correlated with algal densities, indicating poss­ible competition among the algae for CO 2 .

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It has recently been reported that in human sperm cells, the centromeres are clustered in a chromocenter in the interior region of the nucleus. The aim of the present study was to determine the intra-chromocenter organization of the five centromeres of the acrocentric chromosomes responsible for the biosynthesis of rRNA. The acrocentric centromeres were labeled by fluorescence in situ hybridization (FISH) after mild decondensation of the sperm nuclei to preserve the tail structure. The tail was used as a topographical marker for the orientation of the nucleus. The following results were obtained: (a) the association among the five centromeres was higher than expected from random distribution; (b) all the centromeres observed were randomly located within the chromocenter, occupying about 87% of the total area of the internal nucleus; (c) a major subpopulation of centromeres was located in a preferred area occupying 8.3% of the total nuclear area, with a peak 0.6 microm on the lateral axis and 1.0 microm on the apical side of the longitudinal axis; and (d) The dispersion of the centromeres was not influenced by the degree of the nuclear decondensation. We conclude that in human sperm nuclei, the acrocentric centromeres are organized within a nonlocalized structural element in the chromocenter. The chromocenter can range from an expanded size of 87% of the whole nucleus to a preferred size of 8.3% independent of the degree of nuclear decondensation. These findings have important implications for nuclear function (rRNA) that is not directly related to sperm cell function or early embryo development.

The correlation between Li cycling efficiency, Li morphology, Li surface chemistry, and the properties of the Li-solution interphase was investigated in the THE 2Me-THE 2Me-Furan (MF), LiAsF6 electrolyte system. Surface sensitive FTIR, EDAX-x-ray mieroanalysis, SEM, and impedance spectroscopy were used in conjunction with standard electrochemical techniques. Using THF as a cosolvent to 2Me-THF decreases the detrimental impact of contaminants such as water as it is more reactive toward lithium than 2Me-THE The presence of MF (a few percent) influences the Li surface chemistry since its reduction to surface compounds with alkoxy groups suppresses solvent and salt reduction. However, its effect on Li morphology and cycling efficiency is marginal. It is concluded that the main positive impact of this additive reported in the literature is due to the stabilizing effect of the ethers by its possible reaction with trace Lewis acid contaminants in the solutions. The superiority of LiAsF6 as an eleetroiyte for these solutions is attributed to the precipitation of elementary arsenic and arsenic compounds (e.g., LisAs, LixAsFy) on lithium, which modifies Li deposition to become uniform and smooth.