Detection and treatment of bacterial kidney disease (BKD)
was investigated. Experiments were conducted to evaluate the
quantitative, fluorescent antibody technique (QFAT) that is used
to detect, identify, and quantify both typical and 'bar form'
Renibacterium salmoninarum cells. Smears of kidney tissue from
naturally and artificially infected salmonids, both with and...
New ice core analyses show that the prominent rise in atmospheric methane concentration at Dansgaard-Oeschger event 21 was interrupted by a century-long 20% decline, which was previously unrecognized. The reversal was found in a new ∼100-year resolution study of methane in the GISP2 ice core, encompassing the beginning of D-O...
Radiocarbon measurements at ice margin sites and blue ice areas can potentially be used for ice dating, ablation rate estimates and paleoclimatic reconstructions. Part of the measured signal comes from in situ cosmogenic ¹⁴C production in ice, and this component must be well understood before useful information can be extracted...
The “Cayuga syndrome” is a maternally transmitted, naturally occurring thiamine deficiency that causes 100% mortality of larval landlocked Atlantic salmon Salmo salar in several of New York's Finger Lakes, Results of multiyear studies to qualify and quantify the neurobehavioral and gross pathological signs of this condition are described, Affected sac...
The global biogeochemical cycle of methane has received wide attention because of methane's role as a greenhouse gas. Measurements of methane in air trapped in Greenland ice cores provide a high-resolution record of methane levels in the atmosphere over the past ~100 ka, providing clues about what controls the methane...
A study of the phosphorus dynamics in castle Lake, California, is presented.
The approach is (1) to identify the important phosphorus parameters,
(2) to develop and apply methods measuring the parameters in the
field and (3) to develop a computer model of the phosphorus cycle. This
model will be used...
Horizontal ice-core sites, where ancient ice is exposed at the glacier surface, offer unique opportunities for paleo-studies of trace components requiring large sample volumes. Following previous work at the Pâkitsoq ice margin in West Greenland, we use a combination of geochemical parameters measured in the ice matrix (δ¹⁸O[subscript ice]) and...
We present the first successful ⁸¹Kr-Kr radiometric dating of ancient polar ice. Krypton was extracted from the air bubbles in four ~350 kg polar ice samples from Taylor Glacier in the McMurdo Dry Valleys, Antarctica, and dated using Atom Trap Trace Analysis (ATTA). The ⁸¹Kr radiometric ages agree with independent...
We present a new method developed for measuring radiocarbon of methane (¹⁴CH₄) in ancient air samples
extracted from glacial ice and dating 11,000–15,000 calendar years before present. The small size (~20 μg CH₄ carbon), low
CH₄ concentrations ([CH₄], 400–800 parts per billion [ppb]), high carbon monoxide concentrations ([CO]), and low...
We present techniques for obtaining large (∼100 L STP) samples of ancient air for analysis of ¹⁴C of methane (¹⁴CH₄) and other trace constituents. Paleoatmospheric ¹⁴CH₄ measurements should constrain the fossil fraction of past methane budgets, as well as provide a definitive test of methane clathrate involvement in large and...