The nutr~ent content, 6I5N, and F13C of seagrasses in Tomales Bay (California. USA) vary in both space and time. The variations In these measurements were not random, but followed spatial and seasonal patterns that provide ins~ght into the sources and processing of nutrients In the Tomales Bay ecosystem. Wide ranges of carbon, nitrogen, and phosphorus content of green leaves of Zostera marina were found in 72 samples collected over the 2 yr of sampling. Carbon content varied from 29.0 to 40.9% of dry weight, nitrogen from 1.13 to 3.79*,, and phosphorus from 0.11 to 0.90%. Stable isotopic composition was variable as well: the mean 6"N for all samples collected was 9.7 + 0.3% with a range of 6.2%0. Carbon so topic content had a range of 7 5lV&, with a mean 613C of -9,6 + 0.2"/00. There was a strong spatial trend in the N content, but not the P content, of Z. marina leaves from Tomales Bay. The C:N ratio was around 15 near the mouth of the bay and increased linearly with distance into the bay to -25 near the head of the bay; there was a concomitant pattern of increasing 6I5N of seagrass leaves, from 7 % near the mouth of the bay to near 12%0 at the head of the bay. The spatial pattern in N content was only present during summer months, but the spatial pattern in stable isotopic composition was present in both summer and winter. The patterns in the N and 6"N content of the seagrasses indicate the importance of denitrification in the C and N cycles in Tomales Bay. The analysls of patterns in variation of elemental content and isotopic composition of seagrasses is a powerful tool for investigating ecosystem-scale processes in coastal marine systems. Similar analyses of seagrasses from less well studied ecosystems should provide data to generate hypotheses about spatial and temporal variation in processes in these other systems.
A novel approach of the convergent functionalisation of aryl dibromides to form NS5A type inhibitors using C-H activation is reported. The focus of investigation was to reduce the formation of homodimeric side product, as well as to investigate the scope of different aryl dibromides that were tolerated under the reaction conditions. The C-H activation methodology was found to give a viable synthetic route to NS5A inhibitors, with late stage functionalisation of the core portion of the molecule, albeit with some chemical functionalities not tolerated.
SynopsisNearly all male and about 60% of the female Hyperprosopon argenteum from the waters near San Diego, California attained sexual maturity as age group 0 fish. Males matured during fall at 65-95 mm standard length; females matured at N 90 mm during late fall. Females produced broods averaging nine embryos during early April-early June after a 5-6 month gestation period. Brood size was proportional to female size, and was better correlated with weight than with length of female. Larger, age group I and older females became pregnant earlier in the year than smaller, age group 0 females. Males and females grew at equally fast rates during the spring and summer prior to sexual maturity. The growth rate of both sexes thereafter decelerated equally until age 12 months; and growth of males was slower than that of females among age I + fish. By age II, females had attained longer mean body lengths (130 mm) and heavier mean body weights (66 g) than similarly aged males (120 mm and 52 g). Larger maximum female body sizes resulted both from their faster growth during their second year and their greater average longevity.Differences between male and female growth rates and survivorships are related to growth and survivorship within other geographic populations of H. argenteum. Sexual differences in the life history of H. argenteum in general resemble the patterns of maturation, growth, and survivorship within other Embiotocidae.
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