Recently, the results of experimental and theoretical investigations have revealed that, in vaterite, two or even more crystalline structures coexist. In this communication we report evidence of diverse vaterite structures in biogenic samples of different origin. In addition, it is shown that the synthetic vaterite precipitated in the presence of poly-l-aspartate has structures similar to those...

Biogenic amines are typically regarded as neuromodulators rather than fast-acting neurotransmitters. In this issue of Neuron, Pirri et al. report the characterization of LGC-55 in C. elegans, the first identified tyramine-gated chloride channel. This study suggests that the roles of classical and trace biogenic amines in all organisms may need to be reconsidered.

Variation of hydrochemical conditions, with special reference to adequacy of waters as fish habitats, was traced based on selected hydrochemical parameters obtained during the studies conducted from February 2013 till February 2014 year. The results were compared with earlier studies. The sources of organic pollution were identified, and the effect of biogenic substances on the biomass, as well...

Although the Eurachem guide shows some examples, analytical chemists frequently have regarded the estimation of uncertainty as too theoretical and not suitable for the estimation of uncertainties of complex chemical techniques. This is because identifying and quantifying all sources of uncertainty is difficult and laborious, for procedures consisting of numerous steps, many of which are not alw...

Aqueous chemical extractions and X-ray absorption spectroscopy (XAS) analyses were conducted to investigate the reactivity of chemogenic uraninite, nanoparticulate biogenic uraninite, and biogenic monomeric U(IV) species. The analyses were conducted in systems containing a total U concentration that ranged from 1.48 to 2.10 mM. Less than 0.02% of the total U was released to solution in extracti...

Anthropogenic emissions from industrial and automotive sources within the confines of the city of Raleigh, NC have been documented by the North Carolina Department of Environment, Health and Natural Resources, Division of Environmental Management, but no direct biogenic emissions of nitric oxide (NO) from soils has yet been measured. In this study, emissions of NO were measured in Raleigh, NC, ...

An analysis was made of airborne solid particulate matter in Córdoba, a city in the southwestern Iberian Peninsula with a Mediterranean climate. The detection and analysis techniques used enabled solid particles to be classified by size, by biogenic or non-biogenic origin, and by natural source of emission, e.g. pollen grains released by vascular plants during the pollen season, or particles at...

A one-dimensional sediment model was developed by introducing the CIP-CSL2 scheme in the advection term. This enables us to represent fluctuations of the vertical profiles of 100 cm depth, which needs integrations on a longer timescale than 10 kyr, because this scheme avoids smoothing of the vertical profiles due to no numerical diffusion, instead of a commonly used forward scheme. Using the mo...