Postauricular chondrocutaneous flap in auricular reconstruction

We report an unusual case of a 1 cm papillary renal cell carcinoma arising from the outer surface of the free wall of a radiographically simple renal cyst. Most malignancies arising from the wall of a renal cyst are present along the inner surface, usually adjacent to underlying renal parenchyma. While this is a rare occurrence, it does reinforce the need to explore even small solid renal masses.     

Laser turn-on delay and chirp noise effects in Gb/sintensity-modulated direct-detection systems

This paper describes a new IM/DD optical transmission system simulation which incorporates the impact of laser diode stochastic turn-on effects on system performance. Using this simulation, experimentally observed error rate floors, due to inappropriate laser diode biasing, can be theoretically modelled and predicted, for the first time     

Dielectric measurements using a rational function model

A recently proposed rational function model for the aperture admittance of 50 ohm Teflon filled coaxial lines in contact with a homogeneous dielectric is experimentally validated. A calibration technique of the automatic network analyzer utilizing standard terminations and time domain gating is used. Uncertainties in the dielectric properties of reference liquids do not enter the calibration procedure. Experimental results for water and methanol are compared with estimated values. A model expression for the sensitivity of the probe is validated. The sensitivities of two coaxial line probes for the measurements made are determined. Results obtained using the new model are compared with those of other workers     

Evolution of the serum amyloid A (SAA) protein superfamily

The serum amyloid A (SAA) superfamily comprises a number of genes and proteins characterized from a range of mammalian species. The majority of members described to date are dramatically induced during the acute-phase response, suggesting an important short-term beneficial role in the response to tissue injury and inflammation. However, important disease associations have also been proposed for certain SAAs during chronic inflammation. The nomenclature of many of the superfamily members has been the result of comparisons with previously reported sequences implying disease association and/or functional relatedness between such members. The evolutionary relationships of the SAA superfamily members have been investigated by comparisons at both the amino acid and the nucleotide level. The results indicate that all members of the superfamily within a species have been undergoing concerted evolution. This has important implications in ascribing functions and disease associations to individual SAA superfamily members and indicates that designations should not be based on the extent of amino acid identity alone but should be made only following direct experimental observation of the proteins themselves.     

Fast restoration of ATM networks

Asynchronous transfer mode (ATM) is now well recognized as the fundamental switching and multiplexing technique for future broadband ISDN. As these networks will be increasingly relied upon for providing a multitude of integrated voice, data, and video services, network reliability is a key concern. There are several intrinsic features of ATM networks that could potentially be exploited to provide improved restoration techniques, beyond those established for synchronous transfer mode (STM) networks, such as digital cross-connect restoration or self-healing rings. These features include ATM cell level error detection, inherent rate adaptation and nonhierarchical multiplexing. The authors explore the use of these features in developing fast restoration strategies for ATM networks. In particular, they address: (1) ATM error detection capabilities for enhanced failure detection, (2) network rerouting strategies, (3) spare capacity allocation, and (4) network control architecture and related implementation aspects. Their findings suggest that fast network span failure detection and bandwidth-efficient rerouting capabilities can be combined to develop restoration strategies for ATM networks with significantly greater performance-cost ratios when compared to existing STM network restoration strategies     

Forming the optimal union of multiple databases

Many organizations, best illustrated by libraries, have access to hundreds of databases possessing varying degrees of complimentary and overlapping records. While users may receive positive marginal benefits from data duplications, all databases and their services cannot be supported because of resource limitations. This paper attempts to conceptualize the problem of database collection in an environment of multiple databases, with differential content and performance characteristics, diverse users, and limited resources. It defines the database collection problem as a constrained zero-one integer programming problem and solves for the optimal combination or union of databases. Several extensions are shown, where special conditions are imposed on the relationships between databases and/or their availability.     

Improved Poisson intensity estimation: denoising application using Poisson data

Recently, Timmermann and Nowak developed algorithms for estimating the means of independent Poisson random variables. The algorithms are based on a multiscale model where certain random variables are assumed to obey a beta-mixture density function. Timmermann and Nowak simplify the density estimation problem by assuming the beta parameters are known and only one mixture parameter is unknown. They use the observed data and the method of moments to estimate the unknown mixture parameter. Taking a different approach, we generate training data from the observed data and compute maximum likelihood estimates of all of the beta-mixture parameters. To assess the improved performance obtained by the proposed modification, we consider a denoising application using Poisson data.     

Suppression of void coalescence in thermal aging of tin-silver-copper-X solder joints

Addressing the potential for drop impact failure of Pb-free interconnects, the shear ductility after extensive aging of Sn-Ag-Cu (SAC) solders has been improved radically by Co or Fe modifications. Several other SAC+X candidates (X=Mn, Ni, Ge, Ti, Si, Cr, and Zn) now have been tested. Solder joint microstructures and shear strength results show that new SAC+X alloys also suppress void formation and coalescence at the Cu (substrate)/Cu₃Sn interface (and embrittlement) after aging at 150°C for up to 1,000 h. Microprobe measurements of 1,000 h aged samples suggest that Cu substitution by X is usually accentuated in the intermetallic layers, consistent with X=Co and Fe results.