Introduction: the issue of duplicates.

The permanent preservation of objects in global custodianship is a captivating ideal that informs countless museums' corporate identities and governs collection guidelines as well as politics. Recent research has challenged the alleged perpetuity of collections and collected items, revealing their coherence as fragile and dependent on historically, politically and culturally specific conditions. Duplicates offer an instructive point of entry to explore the idea of collection permanence, museum politics, and the mobility of museum objects.

Contested duplicates: disputed negotiations surrounding ethnographic doppelgängers in German New Guinea, 1898-1914.

The issue of duplicates and duplication in ethnographic collection is frequently regarded as a process that begins and ends in the museum as a fundamental act of the process of curating. In contrast, this article maintains, this practice occurred all along the chain of collecting, where indigenous artefacts operated as items of exchange in the context of the colonial encounter. Using the example of German New Guinea, the article maintains that epistemological concerns, as symbolic currency both in terms of inter-museum exchange and in terms of contributing to individual and institutional prestige, guiding ethnographic intuitions had little influence on colonial resident collectors.

A NEIGHBORHOOD-LEVEL POTENTIAL HEALTH IMPACT SCORING TOOL TO SUPPORT LOCAL-LEVEL HEALTH IMPACT ASSESSMENTS.

Health Impact Assessments (HIAs) have quickly become a widely utilized tool for integrating health and health-related evidence and data into decision making processes across a range of projects and polices. Integrating and utilizing the wide range of available data can be daunting. To support communities seeking to engage in health impact assessments, we developed the Neighborhood Potential Health Impact Score (NPHIS) methodology.

The utility of a system dynamics approach for understanding cumulative health risk from exposure to environmental hazards.

The potential of system dynamics modeling to advance our understanding of cumulative risk in the service of optimal health is discussed. The focus is on exploring system dynamics modeling as a systems science methodology that can provide a framework for examining the complexity of real-world social and environmental exposures among populations-particularly those exposed to multiple disparate sources of risk. The discussion also examines how system dynamics modeling can engage a diverse body of key stakeholders throughout the modeling process, promoting the collective assessment of assumptions and systematic gathering of critical data.

Pentadiynylidene and Its Methyl-Substituted Derivates: Threshold Photoelectron Spectroscopy of R-C-R Triplet Carbon Chains.

Mass-selective threshold photoelectron spectroscopy in the gas phase was employed to characterize the dialkynyl triplet carbenes pentadiynylidene (HCH), methylpentadiynylidene (MeCH), and dimethylpentadiynylidene (MeCMe). Diazo compounds were employed as precursors to generate the carbenes by flash pyrolysis. The R-C-R carbon chains were photoionized by vacuum ultraviolet (VUV) synchrotron radiation in photoelectron photoion coincidence (PEPICO) experiments.