Partial discharge pulse pattern recognition using an inductive inference algorithm

This paper presents a novel approach in the area of time dependent partial discharge (PD) pulse pattern recognition, to applications based on the inductive learning (decision tree) approach. Different attributes based on pulse shape analysis are used as representative feature vectors that can accurately capture the unique and salient characteristics of the PD pulse shape. In the training phase, a decision tree is developed to relate the pulse shape with the cavity size by using inductive machine learning. The C4.5 machine learning algorithm is deployed to realize the tree using the training data, since it has the capability of inferring the rules and to produce the tree in terms of continuous features. During testing, the cavity size is recognized by means of the rules extracted from the decision tree. The dependency between the features and the classes are examined using the mutual information approach. The proposed algorithm possesses the inherent advantage of explaining the result via the self-created rule base as demonstrated by the results obtained. Those self-created rules can be employed as the basis for applying a fuzzy expert system for the classification of void sizes in an easily interpreted fashion.     

Effect of microstructure on oxygen permeation in SrCo0.8Fe0.2O3−δ

The effect of microstructure on oxygen permeation in SrCo0.8Fe0.2O3– membranes was investigated using disc samples fabricated under different processing conditions of applied pressure and sintering temperature. The average grain size of the samples was found to remain unchanged as a function of applied pressure, but increased considerably when the sintering temperature was increased from 950 to 1200°C. This change in grain size has a strong effect on the oxygen permeation flux, which increased considerably as the grain size was decreased. The density as well as the microhardness of these samples were also measured and found to change slightly as the processing conditions were changed.     

New method for extraction of effective channel length in submicron MOSFETs

A new method for effective channel length extraction in submicron MOSFETS is presented. It is based on measurements of the saturation voltage V/sub DSAT/ in devices with different channel lengths. The method has been tested using submicron double diffused drain (DDD) MOS devices.<>     

Design of submicrometer CMOS differential pass-transistor logiccircuits

The interaction between the architectural features of CMOS differential pass-transistor logic (DPTL) and the submicron process technology used to implement it are examined. Techniques that exploit the noise immunity associated with the DPTL architecture are presented to effectively enable signal-swing reductions that result in increased speed. The extent to which DPTL can benefit from this signal-swing/speed tradeoff is examined by investigating the impact of device scaling on DPTL operation. A novel DPTL buffer that enables the implementation of a single-phase clocking scheme and the exchange of signal swing for increased circuit speed is proposed. Experimental results are provided     

New protein genetic studies in six Amazonian Indian populations

A total of 732 individuals affiliated with six Amazonian Indian populations were variously studied in relation to 26 protein genetic systems. Eleven of them were found to be monomorphic in these groups, in accordance with previous investigations. Similarities and dissimilarities (the latter involving the Rh, Duffy, haptoglobin and transferrin systems) were observed in relation to earlier investigations in four of these populations (Galibi, Palikour, Mundurucu and Tenharim). A dimeric, cathodal variant of albumin was found among two Galibi subjects, and the fairly common occurrence of CP* ACAY among some South American Indian populations was confirmed. The results in the six populations were compared with those from 29 others. When relationships are searched for among tribes of the same linguistic group, the factor that seems to be most influential is geographical localization, an exception being the pattern observed among the Cayapo subgroups. The latter shows genetic differences of the same level of magnitude as those observed among Ge-speaking tribes.     

Cleavage motifs of the yeast 20S proteasome beta subunits deduced from digests of enolase 1

The 436-amino acid protein enolase 1 from yeast was degraded in vitro by purified wild-type and mutant yeast 20S proteasome particles. Analysis of the cleavage products at different times revealed a processive degradation mechanism and a length distribution of fragments ranging from 3 to 25 amino acids with an average length of 7 to 8 amino acids. Surprisingly, the average fragment length was very similar between wild-type and mutant 20S proteasomes with reduced numbers of active sites. This implies that the fragment length is not influenced by the distance between the active sites, as previously postulated. A detailed analysis of the cleavages also allowed the identification of certain amino acid characteristics in positions flanking the cleavage site that guide the selection of the P1 residues by the three active beta subunits. Because yeast and mammalian proteasomes are highly homologous, similar cleavage motifs might be used by mammalian proteasomes. Therefore, our data provide a basis for predicting proteasomal degradation products from which peptides are sampled by major histocompatibility complex class I molecules for presentation to cytotoxic T cells.     

The beta-gal interferon assay: a new, precise and sensitive method

Cells of a human glioblastoma line were stably transfected with a glial fibrillary acidic protein (GFAP) promoter sequence/lacZ reporter gene. Following this modification, they produced Escherichia coli beta-galactosidase constitutively in amounts that could be measured through their conversion of an added fluorophore into a product readily estimated by fluorimetry. Human interferons (IFN) selectively and in a dose-dependent manner reduce the formation of beta-galactosidase in this system. We have used it as the basis for a novel assay that is sensitive (4-40 pg/ml), precise, completed in 30 h, and applicable to both type I and type II human IFNs. Statistical analysis showed interassay relative standard deviations ranging from 5% to 11%, and most individual assays revealed potencies with limits of error within 85%-115%. Neither partially trypsin-digested IFN nor the other cytokines and mitogens we tested reacted in this system, except for tumor necrosis factor-alpha (TNF-alpha). The high selectivity was further shown by the loss of response to IFN in the presence of the appropriate specific anti-IFN or anti-IFN-gamma receptor antibodies.     

Testicular plasmacytoma following chemical orchiectomy: potential role of hypogonadism in myeloma proliferation

We present a case of a 55 year old man with multiple myeloma who underwent autologous stem cell transplantation and subsequently developed testicular myeloma. Testicular enlargement was observed only after treatment of an incidental prostatic adenocarcinoma with chemical orchidectomy at a time when myeloma was controlled systemically. A subsequent bilateral surgical orchiectomy revealed plasmacytoma in both testis. Enhanced production of B-lymphocytes after castration has been reported and implicates testosterone as a possible negative regulator of B-cell production. We propose that the androgen deficient state may have contributed to the development of plasmacytoma of the testes in our patient. The regulatory role of sex steroids in B-cell development is discussed.