Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Life Sciences
A Rapid Chromatographic Method For Recovery Of 15no2- And No3- Produced By Nitrification In Aqueous Samples, H Kator, Lj Morris, Rl Wetzel
A Rapid Chromatographic Method For Recovery Of 15no2- And No3- Produced By Nitrification In Aqueous Samples, H Kator, Lj Morris, Rl Wetzel
VIMS Articles
The sensitivity and comparative simplicity of N-15 stable isotopic tracer techniques has been used to quantify rates of nitrification in aquatic systems. However, the most commonly used method for recovery of inorganic oxidized nitrogen compounds from aqueous samples, which is based on liquid-liquid partitioning, is time consuming and contamination prone. We describe a solid-phase rapid chromatographic method for recovery of (NO2-)-N-15 and NO3- produced by nitrification in aqueous samples. Compared to liquid-liquid partitioning, the advantages are significantly reduced processing time and reduced potential for contamination. Typical results are presented for the tidal, freshwater reaches of the James River estuary.
Oligomer Composition And Oxygen Binding Of The Hemocyanin Of The Blue Crab Callinectes Sapidus, Cp Mangum, J Greaves, Js Rainer
Oligomer Composition And Oxygen Binding Of The Hemocyanin Of The Blue Crab Callinectes Sapidus, Cp Mangum, J Greaves, Js Rainer
VIMS Articles
In the blue crab, the ratio of hexamers to dodecamers of the O2 carrier hemocyanin varies in natural populations. Isolated dodecamers have a lower O2 affinity and greater cooperativity than isolated hexamers. The difference in O2 binding can also be resolved in native mixtures that differ in polymer composition. A high content of dodecamers in native mixtures is, in fact, correlated with the presence of an invariant polypeptide chain that is believed to link two hexamers to form dodecamers. On the other hand, the content of a variable chain that has been postulated to play a role in hexamer pairing …
Measurement Of Marine Picoplankton Cell-Size By Using A Cooled, Charge-Coupled Device Camera With Image-Analyzed Fluorescence Microscopy, Cl Viles, Me Sieracki
Measurement Of Marine Picoplankton Cell-Size By Using A Cooled, Charge-Coupled Device Camera With Image-Analyzed Fluorescence Microscopy, Cl Viles, Me Sieracki
VIMS Articles
Accurate measurement of the biomass and size distribution of picoplankton cells (0.2 to 2.0-mu-m) is paramount in characterizing their contribution to the oceanic food web and global biogeochemical cycling. Image-analyzed fluorescence microscopy, usually based on video camera technology, allows detailed measurements of individual cells to be taken. The application of an imaging system employing a cooled, slow-scan charge-coupled device (CCD) camera to automated counting and sizing of individual picoplankton cells from natural marine samples is described. A slow-scan CCD-based camera was compared to a video camera and was superior for detecting and sizing very small, dim particles such as fluorochrome-stained …
Unexplained Mortalities Of Hatchery-Reared, Juvenile Oysters, Crassostrea Virginica (Gmelin), Vm Bricelj, Se Ford, Fj Borrero, Fo Perkins, Et Al
Unexplained Mortalities Of Hatchery-Reared, Juvenile Oysters, Crassostrea Virginica (Gmelin), Vm Bricelj, Se Ford, Fj Borrero, Fo Perkins, Et Al
VIMS Articles
Survival. growth and pathology of juvenile oysters. Crassostrea virginica. in off-bottom culture at Oyster Bay and Fishers Island, New York, were monitored during the summer of 1991 to document and help explain the episodic mass mortalities of cultured seed oysters that have occurred in the northeastern USA over the past several years. Al Oyster Bay. where the more detailed study was conducted. 54 to 7So/o losses affected several 1991 cohorts at mean shell heights ranging from IS to 24 mm, within 3 to 6V, weeks of transfer from the hatchery to growout trays. Mortalities occurred in July and August, at …