A novel microbial method for the production of 2',3'-dideoxynucleosides by transdideoxyribosylation has been developed. By screening microorganisms producing 2',3'-dideoxyadenosine (DDA) from 2',3'-dideoxyuridine (DDU) and adenine, Escherichia coli AJ 2595 was selected as the best producer. Optimal pH and temperature for the DDA-producing reaction were ca. 6.5 and 50 degrees C, respectively. Pi...

[1] The millimeter wavelength radar backscattering properties at 94 GHz for six nonspherical ice crystals, which include hexagonal column, hollow, plate, bullet rosette, aggregate, and droxtal with 46 maximum dimensions ranging from 2 to 10,500 mm, are investigated using the discrete dipole approximation (DDA) method and Lorenz-Mie theory. It is found that the radar backscattering cross section...

The theory of the discrete-dipole approximation (DDA) for light scattering is extended to allow for the calculation of radiation forces on each dipole in the DDA model. Starting with the theory of Draine and Weingartner [Astrophys. J. 470, 551 (1996)] we derive an expression for the radiation force on each dipole. These expressions are reformulated into discrete convolutions, allowing for an ef...

The Dynamic Device Association (DDA) framework presented in this paper provides service discovery and secure device access for mobile users. We discuss scenarios and requirements for enabling mobile users to find and access co-located (mobile) multimedia services on demand. As example, we use the dynamic discovery of IP telephony services in a network that an application on a mobile device can ...

The purpose of this research is to provide a physiological-based Dynamic Difficulty Adaptation (DDA) able to be used in a CVA rehabilitation application, and more especially in the Children Rehabilitation Project (CRP). The CRP is an adaptive modular interface destined to CVA’s rehabilitation, and has for purpose to offer a state-of-the-art rehabilitation platform to improve CVA’s rehabilitatio...

In this paper, first the validity of 3-D DDA is examined by comparing its solution for dynamic block displacement with analytical solution. Displacement of a single block on an inclined plane subjected to a dynamic loading is studied for analytical solution with respect to the frictional resistance offered by the inclined slope. 3-D DDA predicts accurately the analytical displacements. The modi...

In the current investigation, chitin and chitosan are extracted from Callinectes amnicola (crab) Penaeus notialis (shrimp) shell wastes using predetermined optimization conditions. The shrimp produces higher yield (26.08%), (16.93%) degree of deacetylation (DDA) 89.73% than yields (19.36%), (13.29%) DDA crab (84.20%). Fourier Transform Infrared (FTIR) acid-base titration methods used to obtain ...

Abstract Obtaining accurate high-resolution representations of model outputs is essential to describe the system dynamics. In general, however, only spatially- and temporally-coarse observations states are available. These can also be corrupted by noise. Downscaling a process/scheme in which one uses coarse scale reconstruct solution states. Continuous Data Assimilation (CDA) recently introduce...

An accurate estimation of ionospheric variables such as the total electron content (TEC) is important for many space weather, communication, and satellite geodetic applications. Empirical physics-based models are often used to determine TEC in these However, it known that cannot reproduce all variability due various reasons their simplified model structure, coarse sampling inputs, dependencies ...