Fingermark detection on non-porous and semi-porous surfaces using NaYF4:Er,Yb up-converter particles

This article describes the first use of an anti-Stokes material, or up-converter, for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes materials can absorb long-wavelength light and emit light at a shorter wavelength. This property is unusual in both natural and artificial materials and so fingermark detection techniques based on anti-Stokes luminescence are potentially sensitive and selective. Latent fingermarks on luminescent and non-luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with sodium yttrium tetrafluoride doped with erbium and ytterbium (NaYF(4):Er,Yb) by dry powder, wet powder, and cyanoacrylate staining techniques. This study illustrates the potential of up-converter phosphors for the detection of latent fingermarks.     

Distinguishing Between Influences on Brazilian Legislative Behavior

Ideal point estimators hold the promise of identifying multiple dimensions of political disagreement as they are manifested in legislative voting. However, standard ideal point estimates do not distinguish between ideological motivations and voting inducements from parties, coalitions, or the executive. In this article we describe a general approach for hierarchically identifying an ideological dimension using an auxiliary source of data. In the case we consider, we use an anonymous survey of Brazilian legislators to identify party positions on a left‐right ideology dimension. We then use this data to distinguish ideological motivations from other determinants of roll‐call behavior for eight presidential‐legislative periods covering more than 20 years of Brazilian politics. We find that there exists an important nonideological government‐opposition dimension, with the entrance and exit of political parties from the governing coalition appearing as distinct shifts in ideal point on this second dimension. We conjecture that the Brazilian president's control over politically important resources is the source of this dimension of conflict, which has recently become far more important in explaining roll‐call voting than the ideological dimension.     

Gating Alleys to Reduce Crime: A Meta-Analysis and Realist Synthesis

Alley gates are designed to limit access to alleys and the crime opportunities they afford. Informed by the acronym EMMIE we sought to: (1) systematically review the evidence on whether alley gates are Effective at reducing crime, (2) identify the causal Mechanisms through which alley gates are expected to work and the conditions that Moderate effectiveness, and (3) collate information on the Implementation and Economic costs of alley gating. The results of our meta-analysis suggest that alley gating is associated with modest but significant reductions in burglary, with little evidence of spatial displacement. We also identified six mechanisms through which alley gates might plausibly reduce crime, and the conditions in which such mechanisms are most likely to be activated.