Amplitude calibration of a digital radio antenna array for measuring cosmic ray air showers

Radio pulses are emitted during the development of air showers, where air showers are generated by ultra-high energy cosmic rays entering the Earth's atmosphere. These nano-second short pulses are presently investigated by various experiments for the purpose of using them as a new detection technique for cosmic particles. For an array of 30 digital radio antennas (LOPES experiment) an absolute amplitude calibration of the radio antennas including the full electronic chain of the data acquisition system is performed, in order to estimate absolute values of the electric field strength for these short radio pulses. This is mandatory, because the measured radio signals in the MHz frequency range have to be compared with theoretical estimates and with predictions from Monte Carlo simulations to reconstruct features of the primary cosmic particle. A commercial reference radio emitter is used to estimate frequency dependent correction factors for each single antenna of the radio antenna array. The expected received power is related to the power recorded by the full electronic chain. Systematic uncertainties due to different environmental conditions and the described calibration procedure are of order 20%.     

Construct of attributional style in depression and marital distress.

Although important theoretically, consistency in attribution responses or attributional style has rarely been investigated empirically. The responses of 150 couples were used to examine whether consistency of attribution responses within attribution dimensions and consistency in the pattern of responses across attribution dimensions were associated with adaptational outcomes. Replicating previous findings, mean attribution scores correlated with depression and with marital distress. Consistency of attribution responses was unrelated to either adaptational outcome, whereas (1) theoretically derived pessimistic and optimistic attribution patterns were related to depression scores and (2) benign and nonbenign marital attribution patterns were related to marital satisfaction scores. The implications of these findings for the level at which attributional style is best conceptualized are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Localization of analyte molecules in MALDI preparations by confocal laser scanning microscopy

In this study, the incorporation of Texas Red-labeled avidin into crystals of 2,5-dihydroxybenzoic acid (2,5-DHB) and 2,6-DHB (used as matrixes for matrix-assisted laser desorption/ionization (MALDI)) was investigated by fluorescence spectrophotometry and confocal laser scanning microscopy (CLSM). The analyte distribution in crystals, grown slowly under controlled conditions, was compared to the analyte localization in different standard preparations (dried-droplet and thin-layer preparation). Texas Red turned out to be a useful fluorescence label in the acidic environments of typical matrixes. Earlier results by absorption spectrophotometry could be confirmed by fluorescence measurements; 2,5-DHB incorporates the analyte proportionally, while 2,6-DHB excludes the protein from its crystal lattice. It is found that the analyte distribution can be analyzed well in both single crystals and standard preparation, by CLSM using Texas Red-labeled analytes. The present study allows for a conclusive and consistent interpretation of analyte incorporation into MALDI preparations.