Memory, emotion, and REM sleep.

Explored the manner in which REM sleep deprivation might affect various aspects of memory processing. A series of tests, including S. Sternberg's (see record 1966-10810-001) test of scanning of immediate memory, past personal and nonpersonal memory, and past emotional memories, was administered to 8 college students after baseline, control-awakening, and REM-deprivation nights. Results show that only past, emotionally important memories may have been affected by REM deprivation; access to the emotion connected with the memories was decreased. This finding is discussed in relation to a possible function of REM sleep and to the effects of REM deprivation on depression. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A transformation of series

The transformation (*) $$\sum\limits_{\nu = 0}^\infty {t_\nu z^\nu \to } \sum\limits_{\nu = 0}^\infty {\left\{ {\sum\limits_{\tau = 0}^{h - 1} {z^\tau } \Delta ^\nu t_{h\nu + \tau } + \frac{{z^h }}{{1 - z}}\Delta ^\nu t_{h(\nu + 1)} } \right\}} \left( {\frac{{z^{h + 1} }}{{1 - z}}} \right)^\nu$$ whereh≥0 is an integer and Δ operates upon the coefficients {t _v } of the series being transformed, is derived. Whenh=0, the above transformation is the generalised Euler transformation, of which (*) is itself a generalisation. Based upon the assumption that \(t_\nu = \int\limits_0^1 {\varrho ^\nu d\sigma (\varrho ) } (\nu = 0, 1,...)\) , where σ(?) is bounded and non-decreasing for 0≤?≤1 and subject to further restrictions, a convergence theory of (*) is given. Furthermore, the question as to when (*) functions as a convergence acceleration transformation is investigated. Also the optimal valne ofh to be taken is derived. A simple algorithm for constructing the partial sums of (*) is devised. Numerical illustrations relating to the case in whicht _v =(v+1) ^?1 (v=0,1,...) are given.     

Alexander Duality and Moments in Reliability Modelling

There are strong connections between coherent systems in reliability for systems which have components with a finite number of states and certain algebraic structures. A special case is binary systems where there are two states: fail and not fail. The connection relies on an order property in the system and a way of coding states with monomials . The algebraic entities are the Scarf complex and the associated Alexander duality. The failure event can be studied using these ideas and identities and bounds derived when the algebra is combined with probability distributions on the states. The x coding aids the use of moments =E(X ) with respect to the underlying distribution. Keywords:Reliability, Monomial ideals, Scarf complex, Alexander dual, Hilbert series, Moments     

Preventing alcohol misuse: The impact of refusal skills and norms.

The purpose of this study was to determine the extent to which refusal skills and norm setting mediated the impact of a school-based prevention program from the Alcohol Misuse Prevention Study (AMPS) on adolescent alcohol overindulgence. The AMPS is a randomized, pre-post, experimental-control study. Respondents in the present study included 6th through 10th graders (ns ranged from 232 to 371). Structural equation modeling analyses using EQS indicated that norm setting mediated the effect of the intervention on alcohol overindulgence at the 7th through the 8th grade and at the 8th through the 10th grade. In contrast, although the prevention program served to increase refusal skills, refusal skills did not mediate the effect of the program on alcohol misuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduction rules for reset/inhibitor nets

Reset/inhibitor nets are Petri nets extended with reset arcs and inhibitor arcs. These extensions can be used to model cancellation and blocking. A reset arc allows a transition to remove all tokens from a certain place when the transition fires. An inhibitor arc can stop a transition from being enabled if the place contains one or more tokens. While reset/inhibitor nets increase the expressive power of Petri nets, they also result in increased complexity of analysis techniques. One way of speeding up Petri net analysis is to apply reduction rules. Unfortunately, many of the rules defined for classical Petri nets do not hold in the presence of reset and/or inhibitor arcs. Moreover, new rules can be added. This is the first paper systematically presenting a comprehensive set of reduction rules for reset/inhibitor nets. These rules are liveness and boundedness preserving and are able to dramatically reduce models and their state spaces. It can be observed that most of the modeling languages used in practice have features related to cancellation and blocking. Therefore, this work is highly relevant for all kinds of application areas where analysis is currently intractable.     

Bond Characterization of Plasma Sprayed Zirconium on Uranium Alloy by Microcantilever Testing

The future production of low enriched uranium nuclear fuel for test reactors requires a well-adhered diffusion barrier coating of zirconium (Zr) on the uranium/molybdenum (U-Mo) alloy fuel. In this study, the interfacial bond between plasma sprayed Zr coatings and U-Mo fuel was characterized by microcantilever beam testing. Test results revealed the effect of specific flaws such as cracks and pores on the bonding of interfaces with a sampling area of approximately 20 μm². TEM examination showed the Zr/U-Mo interface to contain rows of very fine grains (5-30 nm) with the Zr in contact with UO₂. Bond characteristics of plasma sprayed samples were measured that are similar to those of roll bonded samples showing the potential for plasma sprayed Zr coatings to have high bond strength.     

GaAs vertical-cavity surface emitting lasers fabricated by reactive ion etching

GaAs quantum well vertical-cavity surface emitting lasers fabricated using low damage reactive ion etching are discussed. Lasers which are partially and completely etched through their structure are compared. The surface recombination velocity of exposed GaAs is not exacerbated in deep etched lasers; other loss mechanisms in shallow etched lasers have comparable impact on laser performance. Etched lasers exhibit low voltage and small differential series resistance at threshold, while devices fabricated by a combination of etching and ion implantation possess lower threshold current. It is found that reactive ion etching has little additional effect on laser operation, whereas the different device structures considered do influence laser performance.<>     

How virtual are we? Measuring virtuality and understanding its impact in a global organization

Abstract.  Employees in global corporations are increasingly involved in 'virtual teams' on a regular basis. Conflicting definitions of virtuality make it hard to measure such things as how much virtual teaming occurs and how virtual teaming affects performance. As a consequence, it is hard to allocate funding and to design infrastructures and software to support this specific mode of working. Using the concept of discontinuities, or changes in expected conditions, we propose a virtuality index to assess how 'virtual' a given setting is. The discontinuities used include geography, time zone, organization, national culture, work practices, and technology. The index separately measures these aspects of virtuality and their effect on perceived team performance. Data collected at a large multinational corporation clustered into three overarching discontinuities: team distribution, workplace mobility, and variety of work practices. The study revealed that being distributed in and of itself had no impact on self-assessed team performance. Work practice predictability and sociability mitigated effects of working in discontinuous environments, while variety of practices (cultural and work process diversity) and employee mobility negatively impacted performance.     

Grobner bases, abstract tubes, and inclusion-exclusion reliabilitybounds

There is a close mathematical relationship between integer grids of a particular echelon form and coherent systems in reliability in the case of states coded as integer grid points. This paper shows that such an integer representation is the link between abstract tube theory, which gives improved inclusion-exclusion bounds, and an algebraic method, Grobner bases, based on the polynomial ideal of the failure event