984 resultados para Urea and chlorophyll content
Resumo:
This document contains data concerning the proximate composition and energy, fatty acid, sodium, and cholesterol content of finfish, shellfish, and their products as listed in 228 articles published between the years of 1976 and 1984. Also included is a systematic index of the species as referenced in this document listed alphabetically by scientific name. (PDF file contains 60 pages.)
Resumo:
Based on the well known sea ice phase diagram, equations are derived for determining the brine and gas content of sea Ice for high temperatures (range 0 to -2 °C) and low salinities. The presently widely used equations of Cox and Weeks (1982) are valid only for temperatures below -2°C. Fresh-water ice is used as a boundary condition for the equations. The relative salt concentrations in brine are_assumed to be the same as in normal (or standard) seawater. Two sets of equations are presented: 1) accurate formulae based on UNESCO standard sea water equations, and 2) approximate formulae based on general properties of weak solutions. The approximate formulae are not essentially different from the classical system which basically assumes the freezing point to be a linear function of fractional salt content. The agreement between the two approaches is excellent and the approximate system is good enough for most applications.
Resumo:
Time series measurements of dimethylsulfide (DMS), particulate dimethylsulfoniopropionate (DMSPp), chlorophyll a (chl a), algal pigments, major nutrients, and the potential activity of DMSP lyase enzymes were made over a 2 yr period (6 March 2003 to 28 March 2005) near the mouth of the shallow, tidally mixed Newport River estuary, North Carolina, USA. DMSPp had a mean of 43 ± 20 nM (range = 10.5 to 141 nM, n = 85) and DMS a mean of 2.7 ± 1.2 nM (range = 0.9 to 7.0 nM). The mean DMS in Gallants Channel was not significantly different from that measured in the Sargasso Sea near Bermuda during a previous 3 yr time series study (2.4 ± 1.5 nM), despite there being a 43-fold higher mean chl a concentration (4.9 ± 2.4 µg l–1) at the coastal site. In winter, DMS was low and chl a was high in the surface waters of the Sargasso Sea, while the opposite was true at the coastal site. Consequently, DMS concentrations per unit algal chl a were on average 170 times higher in the Sargasso Sea than at the coastal site during the summer, but only 7 times higher during the winter. The much higher chl a-specific DMS concentrations at the oceanic site during the summer were linked to higher ratios of intracellular DMSP substrate and DMSP lyase enzyme per unit chl a. These differences in turn appear to be linked to large differences in nutrient concentrations and solar UV stress at the 2 sites and to associated differences in the composition of algal assemblages and physiological acclimation of algal cells.
Resumo:
The importance of sulphur amino acids, especially of methionine, in our nutrition is too well known to be emphasized. But adequate data on the sulphur and methionine contents of the cheapest of our animal foods viz., fish, are not available. In this note, the total sulphur and methionine content of 18 common fresh water fishes is presented. Total sulphur was determined by Osborne perioxide method (Winton & Winton, 1945) and methionine by the colorimetric method of Horn. (Horn et al., 1946)