Insights into the secondary fraction of the organic aerosol in a Mediterranean urban area: Marseille

A comprehensive aerosol characterization was conducted at Marseille during summer, including organic (OC) and elemental carbon (EC), major ionic species, radiocarbon (¹⁴C), water-soluble OC and HULIS (HUmic LIke Substances), elemental composition and primary and secondary organic markers. This paper is the second paper of a two-part series that uses this dataset to investigate the sources of Organic Aerosol (OA). While the first paper investigates the primary sources (El Haddad et al., 2010), this second paper focuses on the secondary fraction of the organic aerosol. <br><br> In the context of overall OC mass balance, primary OC (POC) contributes on average for only 22% and was dominated by vehicular emissions accounting on average for 17% of OC. As a result, 78% of OC mass cannot be attributed to the major primary sources and remains un-apportioned. Radiocarbon measurements suggest that more than 70% of this fraction is of non-fossil origin, assigned predominantly to biogenic secondary organic carbon (BSOC). Therefore, contributions from three traditional BSOC precursors, isoprene, $\alpha$-pinene and &beta;-caryophyllene, were considered. These were estimated using the ambient concentrations of Secondary Organic Aerosol (SOA) markers from each precursor and laboratory-derived marker mass fraction factors. <br><br> Secondary organic markers derived from isoprene photo-oxidation (ie: 2-methylglyceric acid and 2-methyltetrols) do not exhibit the same temporal trends. This variability was assigned to the influence of NO_x concentration on their formation pathways and to their potential decay by further processing in the atmosphere. The influence of changes in isoprene chemistry on assessment of isoprene SOC contribution was evaluated explicitly. The results suggest a 60-fold variation between the different estimates computed using different isoprene SOC markers, implying that the available profiles do not reflect the actual isoprene SOC composition observed in Marseille. <br><br> Using the marker-based approach, the aggregate contribution from traditional BSOC was estimated at only 4.2% of total OC and was dominated by α-pinene SOC accounting on average for 3.4% of OC. As a result, these estimates underpredict the inexplicably high loadings of OC. This underestimation can be associated with (1) uncertainties underlying the marker-based approach, (2) presence of other SOC precursors and (3) further processing of fresh SOC, as indicated by organosulfates (RSO₄H) and HUmic LIke Substances (HULIS) measurements

Early Detection, Diagnosis and Intervention Services for Young Children with Autism Spectrum Disorder in the European Union (ASDEU): Family and Professional Perspectives

Early services for ASD need to canvas the opinions of both parents and professionals. These opinions are seldom compared in the same research study. This study aims to ascertain the views of families and professionals on early detection, diagnosis and intervention services for young children with ASD. An online survey compiled and analysed data from 2032 respondents across 14 European countries (60.9% were parents; 39.1% professionals). Using an ordinal scale from 1 to 7, parents’ opinions were more negative (mean = 4.6; SD 2.2) compared to those of professionals (mean = 4.9; SD 1.5) when reporting satisfaction with services. The results suggest services should take into account child’s age, delays in accessing services, and active stakeholders’ participation when looking to improve services

Three years of wastewater surveillance for new psychoactive substances from 16 countries

The proliferation of new psychoactive substances (NPS) over recent years has made their surveillance complex. The analysis of raw municipal influent wastewater can allow a broader insight into community consumption patterns of NPS. This study examines data from an international wastewater surveillance program that collected and analysed influent wastewater samples from up to 47 sites in 16 countries between 2019 and 2022. Influent wastewater samples were collected over the New Year period and analysed using validated liquid chromatography - mass spectrometry methods. Over the three years, a total of 18 NPS were found in at least one site. Synthetic cathinones were the most found class followed by phenethylamines and designer benzodiazepines. Furthermore, two ketamine analogues, one plant based NPS (mitragynine) and methiopropamine were also quantified across the three years. This work demonstrates that NPS are used across different continents and countries with the use of some more evident in particular regions. For example, mitragynine has highest mass loads in sites in the United States, while eutylone and 3-methylmethcathinone increased considerably in New Zealand and in several European countries, respectively. Moreover, 2F-deschloroketamine, an analogue of ketamine, has emerged more recently and could be quantified in several sites, including one in China, where it is considered as one of the drugs of most concern. Finally, some NPS were detected in specific regions during the initial sampling campaigns and spread to additional sites by the third campaign. Hence, wastewater surveillance can provide an insight into temporal and spatial trends of NPS use

Interspecific introgression mediates adaptation to whole genome duplication

Adaptive gene flow is a consequential phenomenon across all kingdoms. While recognition is increasing, examples lack of bidirectional gene flow mediating adaptations at loci that manage core processes. We previously discovered concerted molecular changes among interacting members of meiotic machinery controlling crossover number upon adaptation to whole genome duplication (WGD) in Arabidopsis arenosa. Here we conduct a population genomic study to test the hypothesis that adaptation to WGD has been mediated by adaptive gene flow between A. arenosa and A. lyrata. We find that A. lyrata underwent WGD more recently than A. arenosa, suggesting that pre-adapted alleles have rescued nascent A. lyrata, but we also detect gene flow in the opposite direction at functionally interacting loci under the most extreme levels of selection. These data indicate that bidirectional gene flow allowed for survival after WGD and that the merger of these species is greater than the sum of their parts

Le pouvoir de l'eau dans le Sud-Tunisien.

The question of water is treated as constraining factor of the spatial and economic organization and as means of present transformations of the south tumsian society. In a first part is presented the traditional technic and institutional organization of oasian, mountainous and pastoral zones. In a second part are presented the material and institutional means of modern tunisian hydraulic policy, and their numerous consequences. At last the authors try to indicate how the water has become a fondamental stake in the economic struggle between groups, classes and States.La question de l'eau est ici abordée à la fois en tant que facteur contraignant de l'aménagement spatio-économique et en tant que levier de transformations actuelles de la société sud-tunisienne. Dans une première partie, les auteurs abordent la question sociale de l'aménagement hydraulique dans la société traditionnelle, passée ou survivante, à la fois sur le plan des techniques, des institutions, de l'organisation spatiale et de la vie sociale, et ce s'agissant aussi bien des périmètres irrigués ou des zones montagneuses que des zones agropastorales. Dans une deuxième partie, les auteurs abordent la question du poids de l'eau dans la volonté actuelle de développement agricole : sont présentes les moyens matériels et institutionnels de la politique hydraulique tunisienne moderne (Protectorat et Indépendance) dont sont analysées par la suite les nombreuses conséquences socio-économiques. Enfin les auteurs essayent aussi de montrer comment l'eau est devenue un enjeu fondamental dans la lutte économique tant entre groupes que classes et états.Baduel A et P. Le pouvoir de l'eau dans le Sud-Tunisien.. In: Revue de l'Occident musulman et de la Méditerranée, n°30, 1980. pp. 101-134

From Distributed Objects to Hierarchical Grid Components

We propose a parallel and distributed component framework for building Grid applications, adapted to the hierarchical, highly distributed, highly heterogeneous nature of Grids. This framework is based on ProActive, a middleware (programming model and environment) for object oriented parallel, mobile, and distributed computing. We have extended ProActive by implementing a hierarchical and dynamic component model, named Fractal, so as to master the complexity of composition, deployment, re-usability, and e#ciency of grid applications. This defines a concept of Grid components, that can be parallel, made of several activities, and distributed. These components communicate using typed one-to-one or collective invocations