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Compte-rendu d'ouvrage : 144 : Michel Hérold (dir.), Les vitraux du midi de la France : Région Occitanie, Région Sud Provence-Alpes-Côte d’Azur (Corpus Vitrearum, France, série Recensement des vitraux anciens de la France, XI), Rennes, Presses universitaires de Rennes, 2020, 398 p. (365 fig.).
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Fiducial Reference Measurements for Greenhouse Gases (FRM4GHG): Validation of Satellite (Sentinel-5 Precursor, OCO-2, and GOSAT) Missions Using the COllaborative Carbon Column Observing Network (COCCON)
Get PDFThe COllaborative Carbon Column Observing Network has become a reliable source of high-quality ground-based remote sensing network data that provide column-averaged dry-air mole fractions of carbon dioxide (XCO2), methane (XCH4), and carbon monoxide (XCO). The fiducial reference measurements of these gases from the COCCON complement the TCCON and NDACC-IRWG data. This study shows the application of COCCON data for the validation of existing greenhouse gas satellite products. This study includes the validation of XCH4 and XCO products from the European Copernicus Sentinel-5 Precursor (S5P) mission, XCO2 products from the American Orbiting Carbon Observatory-2 (OCO-2) mission, and XCO2 and XCH4 products from the Japanese Greenhouse gases Observing SATellite (GOSAT). A total of 27 datasets contributed to this study; some of these were collected in the framework of campaign activities and covered only a short time period. In addition, several permanent stations provided long-term observations. The random uncertainties in the validation results, specifically for S5P with a lot of coincidences pairs, are found to be similar to the comparison with the TCCON. The comparison results of OCO-2 land nadir and land glint observation modes to the COCCON on a global scale, despite limited coincidences, are very promising. The stations can, therefore, expand on the coverage of the already existing ground-based reference remote sensing sites from the TCCON and the NDACC network. The COCCON data can be used for future satellite and model validation studies and carbon cycle studies
The Stone Age of the Congo Basin
No full textSummary : The Stone Age in the Congo Basin has a rich yet troubled research tradition. During the colonial era, prehistory was high on the research agenda in search of ancient sites yet slipped into the background within the context of postcolonial states focusing on recent history and the last five thousand years. In archaeological terms, attention shifted from flaked stone to pottery and iron as material traces of the past. Issues with site integrity and lack of absolute chronology imply that often the identification of the various phases of the Stone Age, as well as of cultures and industries, is essentially based on typo-technological characteristics. A clear challenge both for studying and for occupation during the Stone Age in the Congo Basin is the rainforest. Though poorly documented at the time of Stone Age occupations, the last twenty-five hundred to four thousand years yield a very dynamic picture of this once-thought immutable biome. Despite all methodological and factual caveats and the disparity of the archaeological record in terms of chronological, typo-technological, behavioral, and environmental characteristics, there can be no doubt about the flexibility and adaptability of human populations and their ancestors in the Congo Basin. The field of genetic studies is increasingly contributing to understanding this fascinating human history of rainforest occupation
Can citizen science-generated data induce policy changes? Insights from policy actors from Uganda
No full textCitizen science has received recognition as an appropriate tool to address global challenges, shape policy and foster sustainable change. While examples of how citizen science has induced policy changes are present in the Global North where the approach is well established, scaling the uptake of citizen science-generated evidence demands insights into the perceptions of key actors influencing policy, be they government or not. However, in the Global South, where citizen science is largely untapped, much remains unknown about how citizen science is conceived by policy stakeholders. This study addresses this gap by examining perceptions of policy actors towards citizen science in Uganda, focusing on the factors that either facilitate or hinder their trust in citizen science-generated data. To achieve this, the study targeted three citizen science initiatives implemented in southwest Uganda to monitor natural hazard disasters and freshwater snails transmitting schistosomiasis. Purposive sampling was employed to select both elected and technical leaders relevant to the objectives of these citizen science initiatives. Eighty semi-structured interviews and nine focus group discussions were conducted with leaders at the district, sub-county, and community levels, followed by a thematic analysis of the data. Preliminary results indicate that there is moderate trust in citizen science- generated data amongst the leaders. Trust is attributed to factors such as the presence of supporting evidence for the data and participant selection procedures. Distrust seems to stem from concerns about the data quality reported by the community members as well as the quality of participants. To foster trust in citizens science-generated data and facilitate impactful citizen science, respondents suggest constant supervision by local stakeholders particularly to verify the data. This underscores the importance of actively involving local community members right from the inception of the project
Sharing is caring? Barcoding suggests co-introduction of dactylogyrid monogeneans with Nile tilapia and transfer towards native tilapias in sub-Saharan Africa
No full textInvasive Nile tilapias negatively impact native tilapia species through hybridisation and competition. However, the co-introduction of parasites with Nile tilapia, and subsequent changes in parasite communities, are scarcely documented. Monogeneans are known pathogens of cultured Nile tilapia, although little is known about their fate once Nile tilapias establish in new ecosystems. We investigate the parasitological consequences of Nile tilapia introduction on native tilapias in basins in Cameroon, the Democratic Republic of the Congo (DRC), and Zimbabwe, focusing on ectoparasitic dactylogyrids (Monogenea). Using the mitochondrial cytochrome oxidase c subunit I (COI) and nuclear 18S-internal transcribed spacer 1 (18S-ITS1) rDNA region of 128 and 166 worms, respectively, we evaluated transmission of several dactylogyrid species. Parasite spillover from Nile tilapia was detected for Cichlidogyrus tilapiae to Coptodon guineensis in Cameroon, Cichlidogyrus thurstonae to Oreochromis macrochir in the DRC, and Cichlidogyrus halli and C. tilapiae to Coptodon rendalli in Zimbabwe. Parasite spillback to Nile tilapia was detected for Cichlidogyrus papernastrema and Scutogyrus gravivaginus from Tilapia sparrmanii and Cichlidogyrus dossoui from C. rendalli or T. sparrmanii in the DRC, and Cichlidogyrus chloeae from Oreochromis cf. mortimeri and S. gravivaginus from O. macrochir in Zimbabwe. 'Hidden' transmissions (i.e. transmission of certain parasite lineages of species that are naturally present on both alien and native hosts) were detected for C. tilapiae and Scutogyrus longicornis between Nile tilapia and Oreochromis aureus and C. tilapiae between Nile tilapia and Oreochromis mweruensis in the DRC, and Cichlidogyrus sclerosus and C. tilapiae between Nile tilapia and O. cf. mortimeri in Zimbabwe. A high density of Nile tilapia occurring together with native tilapias, and the broad host range and/or environmental tolerance of the transmitted parasites, are proposed as factors behind parasite transmission through ecological fitting. However, continuous monitoring and the inclusion of environmental variables are necessary to understand the long-term consequences of these transmissions on native tilapias and to elucidate other underlying factors influencing these transmissions. (c) 2023 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved
Closing the DAta gap to develop Land Surface MOdels for COngo Basin Forests (DAMOCO)
No full textGround-based data suggest tropical forest carbon sinks might soon become less effective at slowing the accumulation of CO2 in the atmosphere. However, Earth System Models fail to reproduce the observed trends of forest carbon sink saturation/decline, partly due to important gaps in the existing data underlying these models. The DAMOCO project intends to fill one of those most important data gaps concerning a tropical region of paramount importance: the Congo Basin. In this project, we are first collecting and/or valorizing data covering all the successional gradients (pioneer, regenerating and mature forest) of the most dominant forest types of the Congo Basin. By combining different but complementary scientific approaches, we produce multi-temporal records of forest dynamics: (i) sub-daily estimates of carbon and water fluxes collected with eddy covariance equipment on the first flux tower in central Africa, (ii, iii) decadal-scale changes in carbon balance and biodiversity through repeated tree and tree trait measurements from a network of permanent forest inventory plots, and finally, (iv) millennial-scale changes in biodiversity through the analysis of ancient charcoal from soil profiles located next to the plots. Secondly, we will combine this data to parametrize a state-of-the-art process-based Land Surface Model (ED2) for the central Congo Basin. Once the model is optimized, we will use it to upscale carbon and biodiversity dynamics for the entire central Congo Basin, apply it to test forest resilience to climate and land-use change in the region and simulate future carbon and biodiversity dynamics under climate and land-use change scenarios. Here, we present the early progress and results of the project. In particular, we focus on our first ancient charcoal data which suggest a gradual change in species composition throughout the Holocene, related to past long- and short-term droughts and fluctuations in population density. Furthermore, we provide an outline of how this paleodata will be integrated and combined with the other data sources in the ED2 Land Surface Model
Cyclododecane as protection for water-sensitive polychromy during water bath desalination of limestone sculptures : the case study of a mid-15th-century wall-mounted memorial from the Burgundian Netherlands
Get PDFICOM-CC 19th Triennial Conference Preprints : Beijing, 17–21 May 2021
ENFORCE: Expertiserapport ref: exp-567 (plaat 1, staal A-00023214) & exp-568 (plaat 2, staal A-00024211) - 27/8/2024
No full textThe Late Pleistocene and Holocene chronocultural and anthracological open-air sequence from Mukila (DRC)
No full textÉtude archéologique et datation des vantaux en bois du portail de l’Hôtel de Ville de Bruxelles donnant sur la Grand-place
No full textDans le cadre d’une étude de documentation avant restauration, l’IRPA a été commissionné par la Ville de Bruxelles pour dater le portail principal de son Hôtel de Ville. Si la principale question de cette commande portait sur l’ancienneté des boiseries, les résultats, inattendus puisqu’ils concluent à une menuiserie de la première moitié du xv ee siècle (contemporaine des maçonneries), ont mené à approfondir l’étude, grâce l’aide de l’équipe archéologique des MRAH. Des relevés archéologiques ont été réalisés, permettant un examen précis de la structure ; une recherche dans l’iconographie ancienne a été menée, ainsi que de premières tentatives de comparaisons stylistiques avec d’autres portails de la même époque