The objective of this paper is to understand and study sustainable product development using a systems approach. In the real world, artifacts interact with each other to form a web structure (known as artifact system (AS)), which has its own laws of evolution. Specifically, this paper focuses on development of “Factor X” model to study the diffusion of ecoinnovation strategies. The concept of “...

There exists evidence that in early stages tumors progress along linear, tubular, or irregular surface structures. This seems to be the case for atypical adenomatous hyperplasia (AAH), a precursor of adenocarcinoma of the lung. We previously published a simplified model, which showed that early structures had a potential towards spontaneous invasive growth following a latency phase. The transit...

A method is described for the assay of gentamicin using the enzyme gentamicin adenylyltransferase derived from an R-factor-carrying strain of Escherichia coli. The reaction involves adenylylation of the gentamicin with ((14)C)-ATP to form a radioactively labelled product. The technique is compared with the plate diffusion and the urease methods. The adenylylation technique gives results compara...

The Fick diffusion equation is combined with the Langmuir adsorption isotherm and the relevant equations from the Gouy-Chapman theory of the electrical diffuse double layer to demonstrate that the effective diffusion coefficient of calcium ions, both in the cytoplasm of the rod outer segment and within the aqueous space bounded by the disk membrane, should be reduced by a factor of 10-100 becau...

Oxygen transfer through a cotton plug follows Fick's law of diffusion. The apparent diffusion constant decreases as the density of cotton packing is increased. Formulas are derived which relate oxygen transfer to cotton-plug dimensions. Calculations indicate that the dimensions of a cotton plug can affect both the maximal oxygen uptake rate and the gas composition inside a shaken flask. In some...

We consider a nonparametric diffusion process whose drift and diffusion coefficients are nonparametric functions of the state variable. The goal is to estimate the unknown drift coefficient. We apply a locally linear smoother with a data-driven bandwidth choice. The procedure is fully adaptive and nearly optimal up to a log log factor. The results about the quality of estimation are nonasymptot...

Sixty-two patients with classical or definite rheumatoid arthritis were subjected to lung function analysis. The various parameters--spirography, plethysmography, blood gas analysis, measurement of lung compliance, and diffusion capacity--were correlated with duration and stage of disease, and with rheumatoid factor titres. A statistically significant correlation was found to exist between Rose...

Motivation Diffusion weighted Hyperecho (HEDW) Imaging [1-3] has maintained some interest during the last years since it has the potential to offer a probe for tissue microstructure. One meaningful parameter for such a multi spin echo diffusion sequence is the knowledge of the exact effective b-factor [4] exhibited. The present work examines the effect of the common simplification to use rectan...