Theory of SiGe waveguide avalanche detectors operating atλ=1.3 μm

The potential performance of SiGe waveguide avalanche photodiodes is analyzed for operation at a wavelength of 1.3 μm. It is found that response speeds in excess of 5 Gbit/s with gains of ~40 should be readily achievable in the absence of carrier trapping effects. Analysis of the electron initiated avalanche current shows an initial low-noise fast pulse due to primary ionization. This is followed by a noisy tail involving hole initiated processes. Structures for future experimental study are proposed     

Predicting the colour of trichromatic prints

The colour resulting from the partial overlap of tiny dots of cyan, magenta, and yellow inks in a matrix is difficult to predict. A method of simulating it on the macro-scale has been devised by measuring discs with coloured sectors using a spectrophotometer. Here the separate colours are mixed within the integrating sphere of the instrument. Although subtractive mixing occurs where colours overlap, the overall result to the eye/brain is interpreted by additive means. The result of mixing known areas of coloured surfaces additively was predicted successfully by Maxwell in the last century. His method, combined with the use of the CIE System, has been successfully used to predict the coordinates of the mixture of coloured sectors measured on the spectrophotometer. The theoretical model developed applies to trichromatic or polychromatic printing, whatever the substrate. © 1995 John Wiley & Sons, Inc.     

Coagulation factor Xa induces endothelium-dependent relaxations in rat aorta

The relaxing effect of coagulation factor Xa on phenylephrine-contracted rat aortic rings was compared with the effect of thrombin and trypsin. All three proteases induced a dose-dependent relaxation in the presence of an intact endothelium. EC50 values were 3 +/- 1, 24 +/- 9, and 16 +/- 1 nmol/L for thrombin, trypsin, and factor Xa, respectively. Whereas thrombin induced rapid relaxations followed by partial recontraction, trypsin and factor Xa induced slower sustained effects. Factor Xa-induced relaxations were not affected by hirudin at high concentrations (1 mumol/L) but were abolished by DX9065A, a specific inhibitor of the catalytic activity of factor Xa. Furthermore, no relaxations to factor Xa could be elicited in the presence of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (100 mumol/L), whereas relaxations were not altered in the presence of the inactive enantiomer N omega-nitro-D-arginine methyl ester (100 mumol/L). Addition of factor Xa together with thrombin induced relaxations that were larger than those induced by thrombin alone, whereas factor Xa had no additional effects on trypsin-induced relaxations. Further-more, factor Xa relaxed thrombin-desensitized aortic rings but was ineffective in trypsin-desensitized tissues. These data suggest that factor Xa acts on a cleavable endothelial receptor that induces NO release, resulting in the relaxation of precontracted rat aortic rings. Factor Xa does not act through endothelial thrombin receptors but may activate another cleavable trypsin-sensitive receptor.     

Europium(III) complexation with glycine

A one to one complex is formed between Eu(III) and glycine in water, with the complexation constant log β₁₁ = −1 ± 0.2 at 25 °C and an ionic strength of 1.0 in HClO₄—NaClO₄. An examination of the complexation thermodynamics leads to the conclusion that the complex is predominantly inner sphere. This is confirmed by preliminary ultrasonic relaxation data below 50 MHz on 0.17 M Eu(III) with 1.92 M glycine at 25 °C.     

Atlantic bottlenose dolphin (Tursiops truncatus) hearing threshold for brief broadband signals.

The hearing sensitivity of an Atlantic bottlenose dolphin (Tursiops truncatus) to both pure tones and broadband signals simulating echoes from a 7.62-cm water-filled sphere was measured. Pure tones with frequencies between 40 and 140 kHz in increments of 20 kHz were measured along with broadband thresholds using a stimulus with a center frequency of 97.3 kHz and 88.2 kHz. The pure-tone thresholds were compared with the broadband thresholds by converting the pure-tone threshold intensity to energy flux density. The results indicated that dolphins can detect broadband signals slightly better than a pure-tone signal. The broadband results suggest that an echolocating bottlenose dolphin should be able to detect a 7.62-cm diameter water-filled sphere out to a range of 178 m in a quiet environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Haidt's Moral Intuitionist Theory: A Psychological and Philosophical Critique.

Jon Haidt's (2001) proposal (see record 2001-18918-008) for a moral intutionist theory of morality is criticized on psychological and philosophical grounds, including (a) the apparent reduction of social influence to one kind, overt compliance, and the virtual ignoring of the role of persuasion in moral and other decision making; (b) the failure to distinguish development of a psychological entity from its deployment or functioning; and (c) the failure to consider, in distinguishing cause and reason as explanatory concepts, the motivating power of reasons. Arguments for an evolutionary approach to morality are also faulted on the grounds that they assume that adaptation is served by nonmoral rather than moral (fairness- and benevolence-based) criteria. Finally, the authors suggest that an intuitionist approach such as that of Haidt may obscure important aspects of moral decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Continuum removed band depth analysis for detecting the effects of natural gas, methane and ethane on maize reflectance

It is known that natural gas in the soil affects vegetation health, which may be detected through analysis of reflectance spectra. Since natural gas is invisible, changes in the vegetation could potentially indicate gas leakage. Although it is known that gas in soil affects plant reflectance, the relationship between natural gas and the development and reflectance properties of plants has not been studied. The objective of this study was to test whether natural gas and its two main components, methane and ethane, affect vegetation reflectance in the chlorophyll and water absorption regions. An experiment was carried out in which maize (Zea mays) plants were grown in pots that were flushed with 10 l of gas per day for 39 ±4 days. Leaf reflectance was measured once a week with a spectrophotometer. The reflectance was analysed using continuum removal of the blue (400-550 nm), red (550-750 nm) and two water absorption features (1370-1570 nm and 1870-2170 nm), after which the band depths and normalized band depths were analyzed for each treatment. The band depth analysis showed that ethane caused an initial increase of 10% in reflectance between 560 and 590 nm, followed by a decrease during the course of the experiment. Normalized band depth analysis showed that ethane caused a reflectance shift of 1 to 5 nm towards longer wavelengths compared to the control reflectance in the visible region. All gases caused an increase in reflectance in the water absorption bands. The physiological reflectance index, PRI, which has previously linked water stress to photosynthetic activity, suggested that the hydrocarbon gases (particularly ethane) decreased the photosynthetic activity of the plants.The combination of reduced band depths in the chlorophyll and water absorption regions and the increased PRI suggests that ethane gas in the soil hampered a normal water uptake by maize plants in an early stage of their growth. Although further research is necessary to upscale the results from the laboratory to the field, the increased reflectance in the 560-590 nm region caused by ethane together with the increased PRI are promising indicators for gas leakage.     

Die eGK-L?sungsarchitektur Architektur zur Unterstützung der Anwendungen der elektronischen Gesundheitskarte

Mit der für 2006 vorgesehenen Einführung der elektronischen Gesundheitskarte für alle gesetzlich und privat Krankenversicherten werden bislang vorwiegend in Papierform vorliegende Daten – wie z.B. Rezepte, überweisungen und Patientenakten – elektronisch verfügbar gemacht.     

Tri-n-butyltin hydride reduction of the end group of a polyphenylene ether

Summary A method using tri-n-butyltin hydride to reduce the 2-methyl-6-(N,N-di-n-butylamino)methyl phenol end group on PPO^®(4) was developed. It generated a polyphenylene ether (PPE) with 2,6-xylenol as the only phenolic end group without causing any significant increase in molecular weight.