Use of Radioisotope Tracer Techniques in Contamination Studies

2009 ◽  
pp. 77-77-5 ◽  
Author(s):  
T. J. Bulat
Keyword(s):  
Tracer Techniques ◽  
Radioisotope Tracer

Nutrient cycling from theMusamother plant at various physiological stages to suckers as affected by spacing and sucker retention using tracer techniques

Fruits ◽  
2002 ◽  
Vol 57 (3) ◽  
pp. 143-151 ◽  
Author(s):  
Sajan Kurien ◽  
Paickattumana Suresh Kumar ◽  
Nerukavil Varieth Kamalam ◽  
Pallacken Abdul Wahid
Keyword(s):  
Nutrient Cycling ◽  
Tracer Techniques

Placental Transfer of Calcium and Strontium in the Rat and Rabbit

1957 ◽  
Vol 189 (1) ◽  
pp. 91-97 ◽  
Author(s):  
R. H. Wasserman ◽  
C. L. Comar ◽  
M. M. Nold ◽  
F. W. Lengemann
Keyword(s):  
Steady State ◽  
Urinary Excretion ◽  
Fetal Development ◽  
Placental Transfer ◽  
Maternal Diet ◽  
Late Pregnancy ◽  
Placental Barrier ◽  
Tracer Techniques ◽  
Comparative Metabolism ◽  
Differential Movement

The comparative metabolism of calcium and strontium during fetal development was investigated in rats and rabbits using double tracer techniques. In general, the placental transfer from dam to fetus of strontium was about one-half that of calcium; the site of discrimination was the placental barrier. The major discrimination occurred in movement of Ca* and Sr* from dam to fetus, with little or no differential movement from fetus to dam. Under steady state conditions in the rat the relative Sr*/Ca* ratios in the fetus, maternal skeleton and diet were 0.17, 0.28 and 1, respectively. The over-all discrimination of 0.17 between fetus and diet resulted from absorption (0.42), urinary excretion (0.63) and placental transfer (0.65). In the rat it was estimated that 92% of the fetal calcium had originated from the maternal diet. In the rabbit during late pregnancy, it was determined that about 24 mg of calcium/fetus/day moved across the placenta as compared with a need of about 13 mg for fetal development.

scholarly journals Integrating multiple chemical tracers to elucidate the diet and habitat of Cookiecutter Sharks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aaron B. Carlisle ◽  
Elizabeth Andruszkiewicz Allan ◽  
Sora L. Kim ◽  
Lauren Meyer ◽  
Jesse Port ◽  
...  
Keyword(s):  
Trophic Ecology ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Environmental Dna ◽  
Small Sample ◽  
Apex Predators ◽  
Central Pacific ◽  
Chemical Tracers ◽  
Important Prey ◽  
Tracer Techniques

AbstractThe Cookiecutter shark (Isistius brasiliensis) is an ectoparasitic, mesopelagic shark that is known for removing plugs of tissue from larger prey, including teleosts, chondrichthyans, cephalopods, and marine mammals. Although this species is widely distributed throughout the world’s tropical and subtropical oceanic waters, like many deep-water species, it remains very poorly understood due to its mesopelagic distribution. We used a suite of biochemical tracers, including stable isotope analysis (SIA), fatty acid analysis (FAA), and environmental DNA (eDNA), to investigate the trophic ecology of this species in the Central Pacific around Hawaii. We found that large epipelagic prey constituted a relatively minor part of the overall diet. Surprisingly, small micronektonic and forage species (meso- and epipelagic) are the most important prey group for Cookiecutter sharks across the studied size range (17–43 cm total length), with larger mesopelagic species or species that exhibit diel vertical migration also being important prey. These results were consistent across all the tracer techniques employed. Our results indicate that Cookiecutter sharks play a unique role in pelagic food webs, feeding on prey ranging from the largest apex predators to small, low trophic level species, in particular those that overlap with the depth distribution of the sharks throughout the diel cycle. We also found evidence of a potential shift in diet and/or habitat with size and season. Environmental DNA metabarcoding revealed new prey items for Cookiecutter sharks while also demonstrating that eDNA can be used to identify recent prey in stomachs frozen for extended periods. Integrating across chemical tracers is a powerful tool for investigating the ecology of elusive and difficult to study species, such as meso- and bathypelagic chondrichthyans, and can increase the amount of information gained from small sample sizes. Better resolving the foraging ecology of these mesopelagic predators is critical for effective conservation and management of these taxa and ecosystems, which are intrinsically vulnerable to overfishing and exploitation.

The rate of renewal in woman of the water and sodium of the amniotic fluid as determined by tracer techniques

1948 ◽  
Vol 56 (6) ◽  
pp. 1156-1159 ◽  
Author(s):  
G.J. Vosburgh ◽  
L.B. Flexner ◽  
D.B. Cowie ◽  
L.M. Hellman ◽  
N.K. Proctor ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Tracer Techniques
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