Various authors (1, 2, 3, 9) have reported that tritiated water as applied to plant roots does not fully exchange with water of various aerial organs, particularly leaves, even after long period of observation. This incomplete equality between tritium concentration in tissue water and external sources has been attributed to an inaccessible component of tissue water which does not exchange (2). ...

A method is described for investigating the rate of loss of water and carbon dioxide from terrestrial insects by absorbing tritiated water and 14CO2 from a gas stream flowing past the insect. The loss of water and carbon dioxide can be studied simultaneously with a time resolution (nominal) down to 2 min. The theoretical and experimental bases of analysing the data are considered in detail. The...

Although urea production and metabolism in lungfish have been thoroughly studied, we have little knowledge of how internal osmotic and electrolyte balance are controlled during estivation or in water. We tested the hypothesis that, compared with the body surface of teleosts, the slender African lungfish (Protopterus dolloi) body surface was relatively impermeable to water, Na(+), and Cl(-) due ...

Tritium is the heaviest and the only radioactive isotope of hydrogen. It decays to the stable isotope 3He by emitting low energy electrons. The short range and low energy of β‐ rays gives rise to almost complete absorption of the radiation energy within the biological matter. While some beta particles can penetrate human skin, tritium's beta particles do not have enough energy to do so. Tritium...

Cation concentration and water content were determined in the normal rainbow trout cornea, aqueous humor, lens, and vitreous humor. Anatomically the rainbow trout cornea possesses a thicker epithelium and a more prominent Bowman's membrane than those found in mammalian corneas. Descemet's membrane and the endothelium appear more primitive than their mammalian counterparts. In vitro, the cornea ...

Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allo...

The yield and distribution of unstable chromosome aberrations induced in human lymphocytes by tritiated water (HTO) has been measured. Tritiated water was mixed with heparinised blood in calculated amounts so as to give 0.1 Gy to 1.5 Gy, 30min and 2 hours. After culturing for 48 hrs, the dicentric yield was measured as a function of dose to the blood. Using a linear quadratic dose-effect relati...