New amino acid polymorphism, Ala/Val4058, in exon 45 of the polycystic kidney disease 1 gene: evolution of alleles

The PKD1 gene, which is responsible for the most common form of autosomal dominant polycystic kidney disease, has recently been cloned and sequenced. Many disease-causing mutations have been characterized in this gene, most of them resulting in premature protein termination. However, mutation analysis not routinely implemented for family investigations in a clinical setting, because of the large size and complexity of the gene. Instead, genetic linkage analysis using highly polymorphic CA dinucleotide repeats that map around the gene is still the method of choice. Recently, a few intragenic polymorphisms have been described that are also useful for linkage studies. Here, a new diallelic polymorphism is described for amino acid residue 4058, Ala/Val4058, with allelic frequencies of 0.88 and 0.12, respectively, and a heterozygosity of 0.23, in the Greek and Greek-Cypriot populations. Interestingly, this polymorphism and Ala4091-A/G, which has previously been described in Caucasians, were not detected in DNA from 44 Japanese samples tested. This is particularly important when allelic frequencies in a particular population are used for linkage analysis of families of different ethnic origin. Also, observation of the two polymorphisms together as haplotypes suggests that the Ala/Val4058 polymorphism occurred more recently than the establishment of the Ala4091-A/G polymorphism, and specifically on the G allele.     

An investigation of methods for the on-line estimation of tool wear

The paper examines the use of the measurements of spindle motor power for the estimation of wear and the detection of the end of effective tool life for a vertical milling machine. The measurements are analysed using spectral analysis and the effectiveness of using moving averages, running-means and cumulative sum of the power spectrum values to estimate wear is evaluated. For a specific machine tool (Beaver NC5), workpiece material (stainless steel) and under a particular set of cutting conditions it is shown that (a) there is a strong correlation between the cumulative sum of the power spectral energies and the total flank wear, and (b) the residuals obtained from computing a least squares linear fit to the plot of cumulative sums of the power spectral energies against cutting time clearly indicates when the tool is entering the region of high wear.     

The effect of two types of C-S-H on the elasticity of cement-based materials: Results from nanoindentation and micromechanical modeling

It has long been recognized, in cement chemistry, that two types of calcium-silicate-hydrate (C-S-H) exist in cement-based materials, but less is known about how the two types of C-S-H affect the mechanical properties. By means of nanoindentation tests on nondegraded and calcium leached cement paste, the paper confirms the existence of two types of C-S-H, and investigates the distinct role played by the two phases on the elastic properties of cement-based materials. It is found that (1) high-density C-S-H are mechanically less affected by calcium leaching than low density C-S-H, and (2) the volume fractions occupied by the two phases in the C-S-H matrix are not affected by calcium leaching. The nanoindentation results also provide quantitative evidence, suggesting that the elastic properties of the C-S-H phase are intrinsic material properties that do not depend on mix proportions of cement-based materials. The material properties and volume fractions are used in a novel two-step homogenization model, that predicts the macroscopic elastic properties of cement pastes with high accuracy. Combined with advanced physical chemistry models that allow, for a given w/c ratio, determination of the volume fractions of the two types of C-S-H, the model can be applied to any cement paste, with or without Portlandite, Clinker, and so on. In particular, from an application of the model to decalcified cement pastes, it is shown that that the decalcification of the C-S-H phase is the primary source of the macroscopic elastic modulus degradation, that dominates over the effect of the dissolution of Portlandite in cement-based material systems.     

Advances in Characterization of Non-Rare-Earth Permanent Magnets: Exploring Commercial Alnico Grades 5–7 and 9

The magnetic domain structure of commercial alnico grades 5–7 and 9 was investigated using a magneto-optical Kerr effect (MOKE) to gain an understanding of their coercivity mechanisms at the micron to millimeter scale. In alnico 5–7, the magnetic domain structure exhibits stripes of alternating high and low induction. Magnetic domains easily cross grain boundaries if neighboring grains have a similar tilt and rotation of their crystallographic axes relative to the magnet body. In contrast for alnico 9, stripe-like magnetic domains are not observed regularly throughout the transverse section; rather, discrete localization of high- and low-induction stripe features are observed. In higher magnification MOKE experiments, i.e., ~100 μm, a zigzag-shaped magnetic domain structure was observed in both alnico 5–7 and 9. The zigzag features are four to five times smaller in size than an average grain of alnico 5–7, implying a pinning mechanism that is caused by structural elements within the grains. Discontinuous and reversible motion on a length scale of a few microns was observed for the zigzag-shaped domains for incremental changes in the applied field of ~10 Oe. Complimentary magnetic force microscopy measurements show that there are domain structures on an even smaller scale, i.e., 2 μm to 100 μm.     

Cascaded power symmetric IIR filter banks and continuityconstrained adaptive algorithms for acoustic echo cancellation insubbands

Teleconferencing systems and hands-free mobile terminals use acoustic echo cancellation (AEC) for high-quality full-duplex speech communication. The problem of aliasing in subband AEC is addressed. Filter banks with implicit notch filtering are derived from cascaded power symmetric-infinite impulse response (CFS-IIR) filters. It is shown that adaptive filters used with these filter banks must be coupled via continuity constraints to reduce the aliasing in the residual echo. A continuity constrained NLMS algorithm is therefore proposed and evaluated     

Eosinophilic cystitis: a rare case which presented as an invasive bladder tumor

Eosinophilic cystitis is a rare inflammatory lesion of the bladder of unknown etiology. It can be confused clinically and cytoscopically with invasive bladder cancer. We report a case in which the lesion presented as an invasive bladder tumor and we discuss the literature in brief.     

Mitigating array sensor malfunctions with mixed second and fourthorder statistics

The authors propose a modified MUSIC algorithm which employs mixed second and fourth order statistics. When an array suffers from sensor malfunction, higher order statistics are used to extend the effective aperture of the faulty array. Simulation results support the potential of this approach which maximises the additional information available in fourth order statistics, while retaining the statistical reliability of second order sample estimates