Trust for Ubiquitous,Transparent Collaboration

In this paper, trust-based recommendations control the exchange of personal information between handheld computers. Combined with explicit risk analysis, this enables unobtrusive information exchange, while limiting access to confidential information. The same model can be applied to a wide range of mobile computing tasks, such as managing personal address books and electronic diaries, to automatically provide an appropriate level of security. Recommendations add structure to the information, by associating categories with data and with each other, with degrees of trust belief and disbelief. Since categories also in turn confer privileges and restrict actions, they are analogous to rôles in a Rôle-Based Access Control system, while principals represent their trust policies in recommendations. Participants first compute their trust in information, by combining their own trust assumptions with others' policies. Recommendations are thus linked together to compute a considered, local trust assessment. Actions are then moderated by a risk assessment, which weighs up costs and benefits, including the cost of the user's time, before deciding whether to allow or forbid the information exchange, or ask for help. By unifying trust assessments and access control, participants can take calculated risks to automatically yet safely share their personal information.     

Theoretical analysis of phase-matched second-harmonic generation and optical parametric oscillation in birefringent semiconductor waveguides

We analyze the phase-matching conditions for second-harmonic generation (SHG) and optical parametric oscillation (OPO) in birefringent nonlinear semiconductor waveguides and apply these results to the model system of ZnGeP(2) on a GaP substrate. The analyses and numerical results show that phase matching can be achieved for OPO and SHG for reasonable guide thicknesses throughout much of the infrared, indicating significant potential applications for nonlinear birefringent waveguides. For the fundamental mode of a relatively thick guide the region of phase matching and the phase-matching angles are similar to those in bulk material. However, the waveguide has the added flexibility that phase-matched coupling can occur between the various modes of the guide. For example, the phase-matching region for SHG can be considerably extended by coupling the pump into the guide in the fundamental, m =, mode and phase matching to the m = mode of the second harmonic. Significantly, the results indicate, among other things, that ZnGeP(2) waveguides with harmonic output in the m = mode can be used for efficient SHG from input radiation in the 9.6-10.6-mum region where bulk efficiencies in this wavelength range are too small to be useful.     

Reconceptualizing Team Identification: New Dimensions and Their Relationship to Intergroup Bias.

In 2 studies framed within social identity theory, the authors examined the relationships among cognitive, affective, and evaluative dimensions of team identification. They also sought to determine relationships between team identification and intergroup bias. Factor analyses in both investigations revealed similar findings. Items corresponding to cognitive identification and affective identification loaded on 1 factor. Items intended to measure evaluative identification loaded on 2 factors that depicted self-evaluations and evaluations perceived by others. Consistent with expectations, the cognitive-affective dimension of team identification was the strongest predictor of intergroup bias in both investigations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A spectrophotometric glutathione S-transferase assay displaying alpha-class selectivity utilizing 1-p-chlorophenyl-4,4-dimethyl-5-diethylamino-1-penten-3- one hydrobromide

The conjugation of 1-p-chlorophenyl-4,4-dimethyl-5-diethylamino-1-penten-3- one hydrobromide (CDDP), a Mannich base of an alpha,beta-unsaturated ketone, to glutathione is catalyzed selectively by alpha-class glutathione S-transferase. The reaction of CDDP with glutathione can be monitored continuously by following the conjugation-dependent decrease in absorbance of CDDP at 307 nm. The Km and Vmax for CDDP with alpha-class glutathione S-transferase from horse liver were determined to be 226 microM and 14.6 mumol/(min.mg), respectively. CDDP is the first example of an alpha-class glutathione S-transferase selective substrate that monitors the glutathione conjugation activity, rather than the glutathione peroxidase activity of the enzyme.     

Chlorosis induced by substituted benzoic acids and related compounds

A number of derivatives of 4-hydroxy-3-nitrobenzoic acid and 4-methoxy-3-nitrobenzoic acid and related compounds have been prepared, and their ability to produce chlorosis in six different species of plants has been examined. This series of compounds caused white and yellow areas to appear in the young tissues of the plants. A representative ester, ethyl-4-methoxy-3-nitrobenzoate, which caused this effect in barley was shown to affect the iron content and to reduce the quantity of pigments significantly. The structural requirements within this series of compounds for producing the type of chlorosis concerned are briefly discussed.     

Course of panic disorder during pregnancy and the puerperium: a preliminary study

Pregnancy has been referred to as a time of well-being for patients with psychiatric disorder. However, this impression is derived primarily from anecdotal reports and retrospective studies, rather than systematic prospective evaluation. In this study, 10 pregnant women with previous histories of panic disorder were evaluated prospectively across pregnancy and the postpartum period using the Structured Clinical Interview for DSM-III-R and the Clinical Global Impression. Information regarding pharmacotherapy received was also recorded. Seven of 10 subjects continued to meet DSM-III-R criteria for panic disorder at all trimester visits. Symptoms persisted for some patients even in the context of treatment with antipanic medications. Most subjects (n = 9) met DSM-III-R criteria at 1-3 months postpartum despite nearly uniform intensification of antipanic treatment. Although some women may experience diminished symptoms of panic during pregnancy, in this sample most continued to experience panic attacks and to require antipanic treatment to control symptoms.     

3,5‐Bis(benzylidene)‐4‐oxo‐1‐phosphonopiperidines and Related Diethyl Esters: Potent Cytotoxins with Multi‐Drug‐Resistance Reverting Properties

A series of 3,5‐bis(benzylidene)‐4‐piperidones 3 were converted into the corresponding 3,5‐bis(benzylidene)‐1‐phosphono‐4‐piperidones 5 via diethyl esters 4 . The analogues in series 4 and 5 displayed marked growth inhibitory properties toward human Molt 4/C8 and CEM T‐lymphocytes as well as murine leukemia L1210 cells. In general, the N‐phosphono compounds 5 , which are more hydrophilic than the analogues in series 3 and 4 , were the most potent cluster of cytotoxins, and, in particular, 3,5‐bis‐(2‐nitrobenzylidene)‐1‐phosphono‐4‐piperidone 5 g had an average IC₅₀ value of 34 nM toward the two T‐lymphocyte cell lines. Four of the compounds displayed potent cytotoxicity toward a panel of nearly 60 human tumor cell lines, and nanomolar IC₅₀ values were observed in a number of cases. The mode of action of 5 g includes the induction of apoptosis and inhibition of cellular respiration. Most of the members of series 4 as well as several analogues in series 5 are potent multi‐drug resistance (MDR) reverting compounds. Various correlations were noted between certain molecular features of series 4 and 5 and cytotoxic properties, affording some guidelines in expanding this study.     

Demonstration of a hot‐carrier photovoltaic cell

We demonstrate a new hot‐carrier photovoltaic cell based on the resonant tunnelling of hot electrons from a narrow‐band‐gap semiconductor to a wider‐band‐gap semiconductor. Hot electrons are photogenerated at a variety of wavelengths in a GaAs absorber followed by resonant tunnelling through a double‐barrier quantum well into an AlGaAs collector, forming an energy‐selective interface in the centre of the device. We show theoretically the presence of a tunnel current from the absorber to the collector under illumination, offering a method to extract carriers from a hot‐electron distribution at zero bias. We experimentally demonstrate a hot‐carrier photovoltaic cell based on this concept. Two features of its measured current–voltage characteristic, namely the peak to valley current ratio and the current peak voltage, are shown to vary with the wavelength of illumination in a way that clearly demonstrates hot‐carrier extraction. Copyright © 2013 John Wiley & Sons, Ltd.