The vast majority of protein sequences are aperiodic; they do not have any strong bias in the amino acid composition, and they use a subtle mixture of all or most of the 20 amino acid residues to code a great number of various structures and functions. In this context, homorepeats, runs of a single amino acid residue, represent unusual, eye-catching motifs in proteins. Despite the sequence simp...

Oligostatins C, D and E, three new antibiotics were found in the culture filtrate of Streptomyces myxogenes nov. sp. SF-1130. Their spectral and chemical properties suggested that oligostatins were basic oligosaccharide antibiotics. They exhibited not only antibacterial activity but also strong amylase inhibitory activity.

An 'across the fence' comparison of farmer paddocks with nearby virgin bush sites was made at 3 locations, to measure the effects of lupins and subterranean clover based pastures on the chemical properties of the soil. Estimated rates of acidification in the 0--60 cm depth were 0.29-0.55 kmol H+/ha.year for wheat-lupin paddocks and 0.16-0.21 kmol H+/ha.year for pasture paddocks. A significant p...

Factors governing the turnover of organic matter (OM) added to soils, including substrate quality, climate, environment and biology, are well known, but their relative importance has been difficult to ascertain due to the interconnected nature of the soil system. This has made their inclusion in mechanistic models of OM turnover or nutrient cycling difficult despite the potential power of these...

The hydrated electron is a crucial species in radiative processes, and it has been speculated that its behavior at the water surface could lead to specific interfacial chemical properties. Here, we address fundamental questions concerning the structure and energetics of an electron at the surface of water. We use the method of ab initio molecular dynamics, which was shown to provide a faithful ...

In order to relate the physical and chemical properties of carbon to the microphonic properties of this material, it has been found necessary to make measurements on physical quantities which are influenced by primary causes beyond the control of the observer. In many problems of the physical and engineering sciences it is possible for the observer to control within narrow limits, the causes of...

The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth's surface, and is central to current origin of life h...

A variational optimization of the second-order density matrix under the P-, Q-, and G-conditions was carried out for a set of diatomic 14-electron molecules, including N(2), O(2) (2+), NO(+), CO, and CN(-). The dissociation of these molecules is studied by analyzing several chemical properties (dipole moments, population analysis, and bond indices) up to the dissociation limit (10 and 20 A). Se...