In the crystal structure of the title compound, C(25)H(20)N(4), the triazinyl ring is nearly coplanar with the planar (r.m.s. deviation = 0.028 Å) phenyl-ethenyl unit, the twist being only 5.8 (2)°; however, the planar carbazolyl unit (r.m.s. deviation = 0.008 Å) is twisted by 47.8 (1)° with respect to the phenyl-ethenyl unit. The nonplanar nature of the mol-ecule explains the phenomenon of lig...

This work concerns 2D SPECT imaging with uniform attenuation in the activity region. In this paper, it is shown that exact and stable reconstruction does not require the data to be known over 360◦ as has been previously assumed. An angular range of 180◦ is sufficient in parallel-beam geometry. A reconstruction formula which uses only data on a half-turn is provided with implementation details. ...

Exponential growth and superradiance regimes in a high-gain free electron laser (FEL) are studied in this paper for both a seeded FEL and a Self-Amplified Spontaneous Emission (SASE) FEL. The results are compared to the earlier superrdaince theory and the recent experimental observation. The influence of an initial energy chirp along the electron bunch on the superradiance mode is explored for ...

Received February 7, 2003 Abstract The Maternal and Child Health Centres (MCHCs) of the Department of Health have been using the Distraction Test (DT) as the main tool for infant hearing screening. Recognising the limitations of the test, a one-year pilot project was conducted to investigate the feasibility of implementing Automated Otoacoustic Emission (AOAE) screening in MCHCs and to compare ...

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Many crucial biological processes operate with surprisingly small numbers of molecules, and there is renewed interest in analyzing the impact of noise associated with these small numbers. Twenty-five years ago, Berg and Purcell showed that bacterial chemotaxis, where a single-celled organism must respond to small changes in concentration of chemicals outside the cell, is limited directly by mol...

In the area of evolutionary theory, a key question is which portions of the genome of a species are targets of natural selection. Genetic hitchhiking is a theoretical concept that has helped to identify various such targets in natural populations. In the presence of recombination, a severe reduction in sequence diversity is expected around a strongly beneficial allele. The site frequency spectr...

We present measurements obtained with the Spitzer Space Telescope in five bands from 3.6–24μm of the northern inner radio lobe of Centaurus A, the nearest powerful radio galaxy. We show that this emission is synchrotron in origin. Comparison with ultraviolet observations from GALEX shows that diffuse ultraviolet emission exists in a smaller region than the infrared but also coinciding with the ...

The discovery of nucleotide diversity captured as single feature polymorphism (SFP) by using the expression array is a high-throughput and effective method in detecting genome-wide polymorphism. The efficacy of such method was tested in rice, and the results presented in the paper indicate high sensitivity in predicting SFP. The sensitivity of polymorphism detection was further demonstrated by ...

Opportunities exist for developing the Acoustic Emission (AE) technique on various forms of rotating machinery, such as gearboxes. This paper provides a short summary on recent developments in the application of AE to gear defect diagnosis, and, experimental results are presented that examine and explore the effectiveness of AE for seeded gear defect diagnosis. It is concluded that the applicat...