Modular implementation of efficient self-checking checkers for the Berger code

A technique for designing efficient checkers for conventional Berger code is proposed in this paper. The check bits are derived by partitioning the information bits into two blocks, and then using an addition array to sum the number of 1's in each block. The check bit generator circuit uses a specially designed 4-input 1's counter. Two other types of 1's counters having 2 and 3 inputs are also used to realize checkers for variable length information bits. Several variations of 2-bit adder circuits are used to add the number of 1's. The check bit generator circuit uses gates with fan-in of less than or equal to 4 to simplify implementation in CMOS. The technique achieves significant improvement in gate count as well as speed over existing approaches.     

Interrelations of social support measures: Theoretical and practical implications.

To obtain a clearer picture of what constitutes social support, we conducted three studies to compare measures of different conceptions of social support. Relations of these instruments to various personality measures were also investigated. Subdividing the construct into discrete functions did not add to the sensitivity of the indices. Measures of received support and support networks were not strongly related to most of the perceived available support measures. Interview and questionnaire approaches were similar in the information they evoked about close supportive relationships. The results suggest that measures of perceived available support, regardless of the way the instruments attempt to break down the construct, generally assess the extent to which an individual is accepted, loved, and involved in relationships in which communication is open. Psychometric characteristics of the measures were associated with differential sensitivity over the range of supportive relationships. The theoretical implications of the findings are discussed with emphasis on the common core underlying social support indices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of calcium phosphate cement mixture and pure calcium hydroxide as direct pulp-capping agents

This review reports the different genetic factors that have been identified either as risk factor for Alzheimer's disease (AD) or directly causing the disease. First are reviewed epidemiological data and biological mechanisms about the apoplipoprotein E gene allele epsilon 4 that is a major risk factor for Alzheimer's disease. The second part describes the mutations responsible for early-onset autosomal dominant AD found in three different genes. The gene located on chromosome 21 encodes the amyloid precusor protein (APP). The presenilin 1 and presenilin 2 genes, located on chromosome 14 and 1 respectively, encode not yet known membrane proteins.