Some new compounds based on bis-benzimidazole moieties have been synthesized and characterized by IR and NMR spectroscopies. The ability of 3a in transition metal cation sensing such as Co2+, Ni2+, Zn2+, Mn2+, Fe2+ and Cu2+ have been investigated by Uv-vis and fluorescence spectroscopy in methanol solvent. The complexation constants and complex stoichiometry of Cu2+ have been determined. The ex...

As a result of climate change, streams are warming and their runoff has been decreasing in most temperate areas. These changes can affect consumers directly by increasing their metabolic rates and modifying their physiology and indirectly by changing the quality of the resources on which organisms depend. In this study, a common stream detritivore (Echinogammarus berilloni Catta) was reared at ...

The ratio of dissolved fixed inorganic nitrogen to soluble inorganic phosphate (N:P) in the ocean interior is relatively constant, averaging approximately 16 : 1 by atoms. In contrast, the ratio of these two elements spans more than six orders of magnitude in lakes and other aquatic environments. To understand the factors influencing N:P ratios in aquatic environments, we analyzed 111 observati...

HISTONE STOICHIOMETRY IN CHICKEN ERYTHROCYTE NUCLEI Everline B. Wright and Donald E. Olins University of Tennessee-Oak Ridge Graduate School of Biomedical Sciences Biology Division, Oak Ridge National Laboratory Oak Ridge, Tennessee 37830 Received January 30,1975 SUM}{ARY: In order to establish a quantitative relationship among the major histone components in chicken erythrocyte nuclei, an elec...

The elemental stoichiometry of sea water and particulate organic matter is remarkably similar. This observation led Redfield to hypothesize that the oceanic ratio of nitrate to phosphate is controlled by the remineralization of phytoplankton biomass1. The Redfield ratio is used universally to quantitatively link the marine nitrogen and phosphorus cycles in numerous biogeochemical applications2–...

The concept of ecological stoichiometry-the balancing of elemental ratios in ecological interactions-has transformed our thinking about processes in natural systems. Here, this perspective is applied to rocky shore ecosystems to explore the consequences of variation in internal nutrient ratios across two trophic levels. Specifically, I measured the internal concentrations of carbon (C) and nitr...

The complexation reaction between salen (Bis(salicylidene)ethylenediamine) and Cu(II) cations in methanol (MeOH), 2-propanol (2-PrOH), acetonitrile (AN), tetrahydrofuran (THF), and chloroform (CHCl3) as nonaqueous solvents at 25º C has been investigated. The stoichiometry and formation constants of complexes have been determined spectrophotometrically and conductometrically by method of continu...

Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. We used long-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L. principis-ruppre...

C:N stoichiometry was investigated in relation to diet (dN), N-deprivation, and worker body size for a diverse assemblage of tropical Amazonian ants. Relative nitrogen (N) deprivation was assayed for 54 species as an exchange ratio (ER), defined as SUCmin/AAmin, or the minimum sucrose concentration, divided by the minimum amino acid concentration, accepted as food by ‡50% of tested workers. On ...