The molecular basis of partial penetrance of splicing mutations in cystic fibrosis

Biotin-labelled DNA probes and restriction-endonuclease digestion (RED) with HindIII were used to study the diversity of resistance plasmids (R-plasmids) from 414 Escherichia coli isolates: 168 from children living in close contact with antibiotic-fed poultry and 246 from the chickens. Full sensitivity to all 10 antimicrobials tested was more common in the isolates from poultry than in those from the children (36.2% v. 9.5%; P < 0.001). Multi-drug resistance, to at least two of the antimicrobials, was relatively common in the isolates from the children (85.5% v. 26.00%; P < 0.001). Overall, 31% of the poultry isolates were resistant to tetracycline alone. Resistance to amoxycillin was due to production of TEM-1 (89%) and TEM-2 (11%). In > 71% of the isolates from children and 79% of those from poultry, resistance was encoded on a 100-110-kb transferable plasmid belonging to incompatibility group FII. However, RED patterns of R-plasmids from the two groups of isolates were highly diverse and not indicative of any close relatedness. This difference in patterns and in the levels of multi-drug resistance indicate that the isolates from the children and those from the poultry represent two distinct pools of resistance plasmids.     

A single-stage three-terminal heterojunction bipolar transistoroptoelectronic mixer

A high-conversion gain three-terminal heterojunction bipolar transistor (HBT) optoelectronic mixer has been demonstrated. The maximum obtained intrinsic conversion gain was 10.4 dB. The mixing performance was measured as a function of the dc bias of the device and local oscillator power level. A SPICE-based large signal model was employed to simulate the device. The main nonlinear effects which contributed to the mixing process were the voltage dependence of the dynamic emitter resistance, and the variation of the current gain in the saturation regime     

A novel general approach for the optimum design of microwave andmillimeter wave subharmonic mixers

The design of subharmonic mixers is complicated and involves separation of signals and application of correct loading at the important idler frequencies. In this paper we present a novel general approach, which enables the designer to establish the optimum loading conditions for the different signals to get low conversion loss and good matching simultaneously. The method is demonstrated by a design example using a 30 GHz X2 subharmonic mixer. In this example it is shown that a nonoptimal design can yield conversion loss of up to 13.5 db, while an optimal design yields a conversion loss of 3.6 db     

Radical and incremental creativity: Antecedents and processes.

This study extends creativity theory and research by differentiating between 2 distinct forms of creative performance: radical and incremental. It also examines the differential effects of certain antecedents on these two forms of creativity. Results demonstrate that intrinsic motivation, problem-driven, and abstract theory-related creative ideas are associated mostly with radical creativity, whereas extrinsic motivation and ideas that are solution-driven and developed on the basis of concrete practices are linked more closely to incremental creativity. Theoretical and managerial implications are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)