Diffusion of responsibility and level of risk taking in groups.

This study reports evidence supporting the following propositions: (a) Group discussion and consensus concerning decisions that involve actual risks and payoffs lead to greater risk taking than occurs in the absence of such discussion and consensus. (b) The mechanism that underlies this group-induced shift toward greater risk taking consists of a diffusion or spreading of responsibility. Using risks and payoffs based on monetary gain and loss for problem solving performance, the above propositions received strong confirmation for male college Ss. The results of various experimental manipulations provided positive support for viewing diffusion of responsibility as the causal factor at work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enzyme-amplified amperometric sandwich test for RNA and DNA.

A one-step enzyme-amplified amperometric sandwich hybridization test for RNA and DNA is described. The test utilizes a carbon electrode, modified with a film of co-electrodeposited avidin and redox polymer; the redox polymer electrically "wiring" horseradish peroxidase (HRP) reaction centers upon contact. The film is made specific for the particular RNA or DNA sequence tested by conjugating its avidin with a biotinylated oligonucleotide, complementary to the assayed sequence. This oligonucleotide-modified redox polymer film, prepared prior to the test, forms the base of the sandwich. The center layer of the sandwich, added in the test, is the analyte RNA or DNA; its top is a second complemetary oligonucleotide, which is HRP-labeled, and is cohybridized in the test. The test consists of mixing the analyte DNA or RNA solution, the HRP-labeled oligonucleotide solution, and a hydrogen peroxide solution, immersing the base-layer carrying electrode applying a potential of 0 V versus Ag/AgCl, and measuring the H2O2 electroreduction current. Completion of the sandwich brings the HRP label into electrical contact with the redox polymer, converting the nonelectrocatalytic base layer into an electrocatalyst for the electroreduction of H2O2 to water. Flow of H2O2 electroreduction current when the electrode is poised near Ag/AgCl potential indicates the presence of the analyte RNA or DNA. The current density for the maximally sandwich-covered electrode was 250 microA cm(-2), exceeding more than a 100-fold the current density flowing upon nonspecific binding of the HRP-labeled oligonucleotide. High concentrations of irrelevant DNA and diluted serum did not interfere with the assay. When the electrodes were rotated in order to make the solution-phase mass transport rapid, the test was completed in approximately 30 min. The test was applied in probing for the presence of a 60-base E. coli mRNA sequence.     

Pit formation observed in a multilayer dielectric coating as a result of simulated space environmental exposure

Certain spaceborne telescope designs require that dielectric-coated lenses be exposed to the energetic electrons and protons associated with the space environment. Test coupons that were exposed to a simulated space environment showed extensive pitting as a result of dielectric breakdown. A typical pit was 50-100 microm at the surface and extended to the substrate material, in which a 10-microm-diameter melt region was found. Pitting was not observed on similar samples that had also been overcoated with a transparent conductive thin film. Measurement of the bidirectional reflectance distribution transfer function showed that pitting caused a fivefold to tenfold increase in the scattering of visible light.     

Software Process Improvement Motivators: An Analysis using Multidimensional Scaling

In this paper we present an analysis of software practitioners' motivations for software process improvement (SPI). Our findings are based on an empirical study of SPI in 13 software companies where we conducted focus groups with nearly 200 software practitioners. Our aim is to better understand how companies can maximise practitioner support for SPI. This insight should help SPI managers establish more effective SPI implementation strategies. In this paper we introduce the use of multidimensional scaling (MDS) in SPI research. MDS is a social science data analysis technique designed to generate a rich visual understanding of human issues. By using MDS we found evidence to suggest distinct clusters of punitive and rewarding SPI motivators. Furthermore our analysis also suggests that different clusters of motivations exist for different staff groups.     

Transfer of the sea anemone pheromone,anthopleurine, by the nudibranchAeolidia papillosa

After the nudibranchAeolidia papillosa eats the sea anemoneAnthopleura elegantissima, anthopleurine, an alarm pheromone from the sea anemone, persists in the tissues of the nudibranch. For at least five days following such a meal, nudibranchs are capable of evoking alarm responses in anemones without touching them, presumably by releasing anthopleurine into the water. The anemone's alarm response to anthopleurine is to withdraw the tentacles and oral disk, the preferred sites of attack forAeolidia. This leaves exposed to attack the anemone body regions with the highest anthopleurine concentrations. Specimens ofAeolidia collected near sources ofAnthopleura are more likely to contain detectable amounts of anthopleurine than those more distant; some nudibranchs collected 0.5 m fromAnthopleura contained enough anthopleurine to evoke alarm responses in anemones they approached. These findings suggest that the predator helps in the transmission of anthopleurine, which may reduce the severity of predation onAnthopleura.     

Combination of sorption tube sampling and thermal desorption with hollow waveguide FT-IR spectroscopy for atmospheric trace gas analysis: determination of atmospheric ethene at the lower ppb level

The determination of organic trace gases in the ambient environment at the lower ppb level is demonstrated based on a novel technique combining sorption tube sampling on Molsieve and Carbosieve S-III, thermal desorption, and detection of the trace analyte by hollow waveguide Fourier transform infrared (HWG-FT-IR) spectroscopy. While ethene concentrations of approximately 5 ppm can be directly observed using HWG-FT-IR, enrichment factors of up to 5000 were achieved by sorption tube sampling and thermal desorption. Detection limits of approximately 1 ppb are reported. Efficient enrichment by the sampling tube is achieved due to the favorable internal volume ( approximately 0.4 cm(3) at a length of 470 mm) of the hollow waveguide serving as a miniaturized gas cell. This new method was validated for ethene by thermodesorption-cryofocusing-GC-FID as the reference method. Analytical performance has been compared for standard gas mixtures and for ethene measurements in urban air. Finally, ethene data from a sampling campaign at two alpine sites in Tyrol/Austria are presented.     

Development of a microfabricated palladium decoupler/electrochemical detector for microchip capillary electrophoresis using a hybrid glass/poly(dimethylsiloxane) device

The fabrication and evaluation of a palladium decoupler and working electrode for microchip capillary electrophoresis (CE) with electrochemical detection is described. The use of the Pd decoupler allows the working electrode to be placed directly in the separation channel and eliminates the band-broadening characteristic of the end-channel configuration. The method used for fabrication of the decoupler and working electrode was based on thin-layer deposition of titanium followed by palladium onto a glass substrate. When employed as the cathode in CE, palladium absorbs the hydrogen gas that is generated by the hydrolysis of water. The effect of the decoupler size on the ability to remove hydrogen was evaluated with regard to reproducibility and longevity. Using boric acid and TES buffer systems, 500 microm was determined to be the optimum decoupler size, with effective voltage isolation lasting for approximately 6 h at a constant field strength of 600 V/cm. The effect of distance between the decoupler and working electrode on noise and resolution for the separation of dopamine and epinephrine was also investigated. It was found that 250 microm was the optimum spacing between the decoupler and working electrode. At this spacing, laser-induced fluorescence detection at various points around the decoupler established that the band broadening due to pressure-induced flow that occurs after the decoupler did not significantly affect the separation efficiency of fluorescein. Limits of detection, sensitivity, and linearity for dopamine (500 nM, 3.5 pA/microM, r(2) = 0.9996) and epinephrine (2.1 microM, 2.6 pA/microM, r(2) = 0.9996) were obtained using the palladium decoupler in combination with a Pd working electrode.     

High-resolution, flat-field, plane-grating, f/10 spectrograph with off-axis parabolic mirrors

A high-resolution, flat-field, plane-grating, f/10 spectrometer based on the novel design proposed by Gil and Simon [Appl. Opt. 22, 152 (1983)] is demonstrated. The spectrometer design employs off-axis parabolic collimation and camera mirrors in a configuration that eliminates spherical aberrations and minimizes astigmatism, coma, and field curvature in the image plane. In accordance with theoretical analysis, the performance of this spectrometer achieves a high spatial resolution over the large detection area, which is shown to be limited only by the quality of its optics and their proper alignment within the spatial resolution of a 13 microm x 13 microm pixelated CCD detector. With a 1500 lines/mm grating in first order, the measured spectral resolving power of lambda/Dlambda = 2.5(+/-0.5) x 10(4) allows the clear resolution of the violet Ar(I) doublet at 419.07 and 419.10 nm.