Water-use efficiency and stable isotope composition were studied in three tropical tree species. Seedlings of Tectona grandis, Swietenia macrophylla and Platymiscium pinnatum were grown at either high or low water supply, and with or without added fertilizer. These three species previously exhibited low, intermediate and high whole-plant water-use efficiency (TE) when grown at high water supply...

Patterns of species interactions affect the dynamics of food webs. An important component of species interactions that is rarely considered with respect to food webs is the strengths of interactions, which may affect both structure and dynamics. In natural systems, these strengths are variable, and can be quantified as probability distributions. We examined how variation in strengths of interac...

Understanding river food webs requires distinguishing energy derived from primary production in the river itself (autochthonous) from that produced externally (allochthonous), yet there are no universally applicable and reliable techniques for doing so. We compared the natural abundance stable isotope ratios of hydrogen (deltaD) of allochthonous and autochthonous energy sources in four differen...

Broad-bandwidth, high-spectral-resolution optical detection of human breath has identified multiple important biomarkers correlated with specific diseases and metabolic processes. This optical-frequency-comb-based breath analysis system comes with excellent performance in all criteria: high detection sensitivity, ability to identify and distinguish a large number of analytes, and simultaneous, ...

Interacting human and environmental pressures influence the structure and dynamics of marine food webs. To describe and predict the effects of these pressures, theoretical advances need to be supported by a capacity to validate the underlying models and assumptions. Here, we review recent applications of nitrogen stable isotope analysis in marine food web and macroecological research, with a fo...

The rise of stratified societies fundamentally influences the interactions between status, movement, and food. Using isotopic analyses, we assess differences in diet and mobility of individuals excavated from two burial mounds located at the `Atele burial site on Tongatapu, the main island of the Kingdom of Tonga (c. 500 - 150 BP). The first burial mound (To-At-1) was classified by some archaeo...

The single atom counting rate of a rare isotope and the loading rate of another stable isotope with an abundance over 10 orders of magnitude larger are measured in one atom trap. The linear correlation between the measured counting/loading rates is examined to determine the (84)Kr/(82)Kr and (85)Kr/(83)Kr ratios of a Kr gas sample. Experiments show that the relative uncertainty is reduced to 1....

Studies of Fe absorption in pregnancy often make unfounded assumptions of erythrocyte incorporation. Therefore, we measured the absorption and utilisation of Fe during early and late pregnancy by the erythrocyte incorporation of two stable isotopes. 8.5 mg 57Fe (oral) and 0.5 mg (58)Fe (intravenous) were given to five non-pregnant women, to five women in early gestation (12 weeks) and five wome...

14 The elemental (C, N and P) and isotopic (δ 13 C, δ 15 N) content of leaves of the seagrasses 15 Thalassia testudinum, Halodule wrightii, and Syringodium filiforme were measured across a 16 10,000 km 2 survey of the seagrass communities of South Florida in 1999 and 2000. Trends at 17 local and broad spatial scales were compared to examine interspecific variation in the seagrass 18 characteris...