Agroforestry can increase the sequestration of carbon (C) in soils of tropical agroecosystems through increased litter and tree pruning inputs. Decomposition of these inputs is a key process in the formation of soil organic matter and in nutrient cycling. Our objectives were to study decay of tree pruning mulch and effects on soil C and N in a shaded coffee agroecosystem in Hawaii. Chipped tree...

Biofilms are aggregates of bacterial cells attached to a surface. Oral biofilms (" plague ") are major contributors to tooth decay (dental caries) and are a potential conduit for infection and disease. These biofilms have been shown to be resistant to removal by traditional oral hygiene practices. Novel prophylactic and in situ treatment methods are therefore needed to address this problem. Whi...

The solvent can exert significant in!-?uence on the pathways and rates of radiationless decay of the excited states of solute molecuIes. A major barrier to eIucidating such el3ects is the diversity of solute-solvent interactions which make it difficult to assign experimental observations to specific solvent properties. There exists, therefore, a great need for systematic experimental studies ai...

we study the exponential decay of global solution for an n-dimensional thermo-elasticity systemin a bounded domain of ℜn . by using the multiplier technique and constructing an energy functional welladapted to the system, the exponential decay is proved.

A random channel approach is developed for reaction-diffusion processes in disordered systems. Although the starting point of our research is the kinetic study of the decay and preservation of marine organic carbon, our approach can be used for describing other disordered kinetic catalytic processes with random pathways. We consider a generic catalytic mechanism with two species: a) a catalyst,...

Hydroxyl radicals from the radiolysis of N20 / 0 2 (4:l)-saturated aqueous solutions of acetone (10 3 mol dm -3) react with the solute by H-abstraction thereby forming acetonyl radicals. As shown by pulse radiolysis, the acetonyl radicals rapidly add oxygen (k = 3 x 109 dm3m ol_1s_1) thereby forming acetonylperoxyl radicals which decay by second-order kinetics (2 k = 8 x 10* dm3mol 's -1). Unde...

Biofilms serve essential ecosystem functions and are used in different technical applications. Studies from stream ecology and waste-water treatment have shown that biofilm functionality depends to a great extent on community structure. Here we present a fast and easy-to-use method for individual cell-based analysis of stream biofilms, based on stain-free flow cytometry and visualization of the...

We investigate random walks on a lattice with imperfect traps. In one dimension, we perturbatively compute the survival probability by reducing the problem to a particle diffusing on a closed ring containing just one single trap. Numerical simulations reveal this solution, which is exact in the limit of perfect traps, to be remarkably robust with respect to a significant lowering of the trappin...

A comprehensive study was conducted to evaluate the persistence of thiram in water and soil under controlled conditions and on two plants, namely tomato and radish, in field conditions. In order to follow the decay of the pesticide, an HPLC procedure was developed employing an octadecyl endcapped RP-C18 column using a mixture of acetonitrile and water as the mobile phase and an ultraviolet dete...

Low density (approximately 10(7) cm(-2)), small sized InGaAs quantum dots were grown on a GaAs substrate by metal-organic vapor-phase epitaxy and a special annealing technique. The structural quantum dot properties and the influence of the annealing technique was investigated by atomic force microscope measurements. High-resolution micro-photoluminescence spectra reveal narrow photoluminescence...