Institut National de Police Scientifique

The detection and identification of unknown organic pollutants in complex environmental and forensic samples remain major analytical challenges. While numerous finely tuned Liquid Chromatography- Mass Spectrometry (LC-MS) methods exist for specific compound classes, no transversal strategy has been proposed to date. Here we propose an “all-in-one” LC-MS strategy robust enough to handle the unknown and broad enough to encompass multiple chemical families within a single analytical framework. Our approach combines an extensive meta-analysis of published LC-based methods with experimental validation on model mixtures and real forensic samples. From a systematic review of hundreds of reported conditions, we established a structured database of key LC parameters for selected pesticides, household products, and dyes. This enabled the design of a cross-family LC-MS method validated on representative compounds, and successfully applied to authentic casework, including suspicious delivery packages and household cleaning agents in forensic investigations. Rather than relying on novel instrumentation, this work provides the first literature-driven, experimentally validated workflow for broad-spectrum, non-targeted LC-MS detection. This strategy, widely applicable across environmental and forensic applications, is a valuable resource for harmonization, spectral library growth, and automated annotation. Moreover, the compiled reference database of chromatographic conditions constitutes a unique method development tool for the community.

ABSTRACTUrban river bathing is re‐emerging across Europe, driven by social demand and climate change impacts. The Urban Bathing Consortium, an interdisciplinary and intersectoral consortium initiated at the University of Lyon (France), is at the forefront of studying the challenges and opportunities of creating and managing healthy, safe, and accessible river bathing spaces. Through interdisciplinary collaboration among researchers and stakeholders, the consortium proposed an analytical framework, identifying seven critical dimensions for urban river bathing: the history and revival of city‐river relationships, legal and regulatory frameworks, bathing water quality, river drowning risks, river ecosystems, social perspectives, and urban planning. By examining these dimensions with state‐of‐the‐art approaches and drawing on Lyon's experiences, the study provides scientific insights and practical recommendations for future sustainable urban river bathing development. These include revitalizing historical city‐river connections, aligning local regulations with EU guidance, advancing holistic microbial water quality control, enhancing safety measures, incorporating ecological considerations, balancing competing river uses in urban planning, and addressing social needs for inclusive river governance.

Abstract This paper focuses on the analysis of radiation emitted by flames fueled by diesel, kerosene, heptane, polyurethane foam, and wood, conducted at a medium scale. The emitted radiation was studied using a Fourier Transform InfraRed (FTIR) spectrometer covering the wavenumber range of 700 - 5500 cm−1 (corresponding to the wavelength range of 1.82 - 14.3 μm). In addition, opacity measurements were performed at different wavelengths (410, 520, 785, 1650, and 3800 nm) using laser beams passing through the flames. The optical thickness was plotted against wavelength, and two different behaviors were observed. For kerosene, diesel, and PU foam, the optical thickness showed a characteristic straight line on a log-log scale, which is typical of soot, as their optical properties follow an inverse power law with wavelength. Heptane and wood showed significantly lower optical thickness, consistent with their lower soot production. Their optical thickness does not follow a straight line on a log-log scale. Transmittance measurements were used to calculate the equivalent flame emissivity at different wavelengths, which allowed an equivalent flame temperature to be derived by fitting the intensity spectrum with a 1D model of radiation emitted by a homogeneous isothermal column.

SummaryThe aim of this study is to investigate the radiative protection provided by various fire hose nozzles used by several Fire Rescue Services in France and to propose an experimental set‐up to quantify it. This study combined the use of radiative sources (a radiant panel or a fire inside a standard shipping container) and metrological devices (radiative heat sensors, IR camera and spectrometer) to estimate the radiative attenuation of water sprays used to protect the firefighters against thermal effects which occur during a fire. For all the fire hose nozzles tested in this work, the maximal effective attenuation reaches 75%. For most of them, an increase of the flow rate improves the radiative attenuation. However, this study shows that a similar attenuation can be reached for different flow rates, suggesting that the droplet size diameter and the droplet volume fraction also play a significant role in the efficiency of the provided spray.

L’expression et la gestion des émotions dans une négociation policière de crise sont souvent évoquées mais rarement étudiées de façon scientifique. Dans le cadre d’une collaboration entre la recherche universitaire et des forces d’intervention de police (en France et en Suisse), nous avons retranscrit 14 négociations réelles. Nous nous inspirons de la façon dont Rogan et Hammer (1995) découpaient les séquences et calculaient un score d’affect dans trois cas réels d’incidents. Sur un échantillon plus important, nous mobilisons des méthodes issues de l’analyse statistique et informatique des donnés textuelles et de l’analyse automatique des contenus. Les premiers résultats conduisent à renoncer aux indexations émotionnelles automatiques classiques. En effet, le contexte de violence et de perte des normes de conversation perturbe les indexations. On propose donc une nouvelle indexation en contexte. Les analyses statistiques exploratoires permettent alors de visualiser la dynamique émotionnelle des échanges entre instigateurs et négociateurs, ainsi que son évolution dans les phases des crises. Dans un premier temps, le négociateur identifie la nature de l’expression émotionnelle (structurelle vs conjoncturelle). Dans une deuxième étape, l’instigateur exprime des émotions négatives d’approche auxquelles le négociateur répond par des expressions positives d’évitement. Dans un troisième temps, l’instigateur peut évoluer vers une émotion négative d’évitement auxquelles le négociateur répond par des expressions positives d’approche. Enfin, le dernier temps sera celui de la neutralisation émotionnelle de la part de l’instigateur, qui permet au négociateur de conquérir l’espace lexical et de l’amener vers la résolution pacifique de la crise. On décrit les conséquences théoriques et méthodologiques de ces résultats ainsi que les implications pour la formation et le suivi des professionnels de la négociation de crise.