How many IRT parameters does it take to model psychopathology items?

The authors compared the fit of the 2- and 3-parameter logistic models (2PLM; 3PLM) on 15 unidimensional factor scales derived from the Minnesota Multiphasic Personality Inventory--Adolescent item pool. Log-likelihood chi-square deviance tests indicated that a 3PLM provided an improved fit. However, residual statistics Indicated that the difference in fit between the 2 models was negligible. An unexpected finding was that from 10% to 30% of the items had substantial lower asymptote parameters (c ≥ .10) when the scales were scored in the pathology or nonpathology directions. The authors argue that the large lower asymptote parameters are attributable to item-content ambiguity possibly caused by item-level multidimensionality. These findings suggest that the direction of scoring can critically affect an item response theory analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aerosol Generation of Lanthanum Aluminate

Spherical lanthanum aluminate powders approximately 1 μm in diameter were produced using spray pyrolysis techniques. These materials were characterized by X-ray diffractometry and scanning electron microscopy. Two intermediate products were produced and identified as lanthanum oxide and aluminum oxide. These intermediates were present in varying amounts in all of the aerosol-furnace-prepared materials and reflect the short residence time of the aerosols in the furnace. Samples of each aerosol-furnace preparation were further annealed in air for 1 h at 1100°C, and all of them converted completely to lanthanum aluminate.     

Lexical selection in bilingual speech production does not involve language suppression.

The "hard problem" in bilingual lexical access arises when translation-equivalent lexical representations are activated to roughly equal levels and, thus, compete equally for lexical selection. The language suppression hypothesis (D. W. Green, 1998) solves this hard problem through the suppression of lexical representations in the nontarget language. Following from this proposal is the prediction that lexical selection should take longer on a language switch trial because the to-be-selected representation was just suppressed on the previous trial. Inconsistent with this prediction, participants took no longer to name pictures in their dominant language on language switch trials than they did on nonswitch trials. These findings indicate that nontarget lexical representations are not suppressed. The authors suggest that these results undermine the viability of the language suppression hypothesis as a possible solution to the hard problem in bilingual lexical access. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strengthening mechanisms in nanostructured high-purity aluminium deformed to high strain and annealed

Samples of pure aluminium (99.99%) have been produced by accumulative roll-bonding to a large strain followed by a heat treatment, where a two-step annealing process has been used to produce samples with large variations in structural parameters such as boundary spacing, misorientation angle and dislocation density. These parameters have been quantified by a structural analysis applying transmission electron microscopy and electron backscatter diffraction, and the mechanical properties have been determined by tensile testing at room temperature. Strength–structure relationships have been analysed based on the operation of two strengthening mechanisms—grain boundary and dislocation strengthening—and good agreement with experiments has been found for the deformed sample. However, for samples where the density of dislocation sources has been reduced significantly by annealing, an additional strengthening mechanism, so-called dislocation source-limited hardening, may operate as a higher stress is required to activate alternative dislocation sources.     

Urban Interests and Campaign Contributions: Evidence from Los Angeles

Abstract: Political activity is a key determinant of group influence in urban politics. This article examines a form of political activity often ignored by urban scholars, namely, campaign contributions. Using data from the 2001 Los Angeles municipal elections, I explore contributions from various urban interests. Because of its ability to overcome collective action problems, I expect business to be the main contributors, and among corporate interests, I expect development concerns to predominate. Although business contributes the vast majority of funds, contrary to expectations, land use interests are not the most active contributors, a spot reserved for professional concerns. As a whole, non‐corporate interests, often allied against the business community, are as active or more active than many corporate contributors. And, in general, patterns of contributions reflect individual, rather than organizational, activity.     

Time effects in criteria for acceptable risk

A simple normative theory is proposed for the responsible management of risks to the public. A ‘lifesaving’ alternative, if it is truly to save lives, should return to the community more years of life expectancy in good health than the years of work consumed to pay for its cost. This common-sense time principle of risk management provides a criterion for acceptable risk that is applicable in connection with cost-utility analysis. The principle is a benchmark, providing a unified rationale for the assessment of risks in health care and technology. Integration of acceptable risk criteria with criteria for national performance can be achieved via applicable compound social indices such as the Life Quality Index or the Human Development Index.     

On the Computation of Stability in Multiple Coalition Formation Games

In non-cooperative models of coalition formation, players have to decide whether or not to participate in a coalition (alliance). Game theoretic analyses of the formation of alliances in games with externalities, stress the difficulties in designing self-enforcing treaties because of free-riding. The presence of a strong free-rider incentive prevents most alliances of being stable and/or effective. This paper focuses on computing stability in a game on multiple coalition formation with membership rules and different transfer schemes. A new mathematical programming notation for game theory concepts is outlined. To compute stability, the new notation is used for implementation into computer coding. Implementation and computation aspects are discussed. Numerical illustration of the algorithm shows that stability varies with the applied membership rules and transfer schemes. An application of coalition formation to International Environmental Agreements (lEAs) is provided.Elena Sáiz was supported by the Wageningen Institute for Environment Climate Research (WIMEK)     

Tribological measures for controlling material flow in sheet-bulk metal forming

Sheet-bulk metal forming (SBMF) is characterized by successive and/or simultaneous occurrence of quite different load conditions regarding stress and strain states. These conditions significantly influence the material flow and thus the geometrical accuracy of the components. To improve the product quality a control of the material flow is required. An appropriate approach is given by locally adapted tribological conditions due to surface modifications of tool and workpiece, so-called tailored surfaces. Within the present study different methods to adapt the surfaces are presented and investigated with respect to their tribological effectiveness in SBMF. In a first step, requirements regarding necessary adaptions of the friction values for two SBMF processes are numerically defined. Based on the requirements different tailored surfaces are presented and analyzed regarding their tribological influence. Finally, the potential of surface modifications to improve SBMF processes is shown.