خيارات البحث
النتائج 621 - 630 من 630
Heavy metal concentrations in sharks, rays and chimaeras from the western Mediterranean Sea النص الكامل
2024
Carrasco-Puig, P. | Colmenero, A.I. | Ruiz-García, D. | Molera-Arribas, A.J. | Hernández-Martínez, A.M. | Raga Esteve, Juán Antonio | Barría, C.
The potential bioaccumulation of pollutants, such as heavy metals, may pose a threat to the western Mediterranean chondrichthyans and human consumers. Therefore, the first extensive assessment of cadmium (Cd), lead (Pb), and copper (Cu) concentrations in the muscle tissue of 17 species of sharks, rays, and chimaeras in this region was conducted via Microwave Assisted Extraction (MAE) and Graphite Furnace Atomic Absorption Spectrometry (GFAAS). Significant differences between species were observed, particularly related to the rabbit f ish (Chimaera monstrosa) and the velvet belly lantern shark (Etmopterus spinax), which exceeded the European Union (EU) Commission Regulation 2023/915 threshold of Cd. Overall, heavy metal concentrations correlated negatively with size and trophic level but positively with depth. Although the consumption of these species may entail minimal risk to adult humans, caution is advised, especially for children. These findings are important due to the widespread consumption of chondrichthyans in many western Mediterranean regions.
اظهر المزيد [+] اقل [-]Exposure of honey bees to mixtures of microbial biopesticides and their effects on bee survival under laboratory conditions النص الكامل
2024
Alkassab, Abdulrahim T. | Erler, Silvio | Steinert, Michael | Pistorius, Jens
Biopesticides, having as active ingredients viruses, bacteria, or fungi, are developed to substitute or reduce the use of chemical plant protection products in different agrosystems. Though the application of mixtures containing several products is a common practice, interactions between microbial biopesticides and related effects on bees as non-target organisms have not been studied yet. In the current study, we exposed winter bees to five different microbial-based products and their combinations at the maximum recommended application rate to assess their responses. Laboratory oral exposure tests (acute/chronic) to single or binary products were conducted. Survival and food consumption of the tested bees were evaluated over the experimental duration. Our results show that some product combinations have potential additive or synergistic effects on bees, whereas others did not affect the bee’s survival compared to the control. Exposure of tested bees to the most critical combination of products containing Bacillus thuringiensis aizawai ABTS-1857 and B. amyloliquefaciens QST 713 strongly resulted in a median lifespan of 4.5 days compared to 8.0 and 8.5 days after exposure to the solo products, respectively. The exposure to inactivated microorganisms by autoclaving them did not differ from their respective uncontaminated negative controls, indicating effects on bee mortality might originate in the treatment with the different microorganisms or their metabolites. Further investigations should be conducted under field conditions to prove the magnitude of observed effects on bee colonies and other bee species.
اظهر المزيد [+] اقل [-]State of water quality monitoring and pollution control in Africa: towards developing an African Water Quality Program (AWaQ) النص الكامل
2024
Mukuyu, Patience | Jayathilake, Nilanthi | Tijani, M. | Nikiema, Josiane | Dickens, Chris | Mateo-Sagasta, Javier | Chapman, D. V. | Warner, S.
The African Ministers’ Council on Water (AMCOW) Secretariat committed to design and implement an African Water Quality Program (AWaQ) in its Strategic Operational Plan (2020-2024) considering the guiding frameworks it uses such as the Africa Water Vision 2025, United Nations Sustainable Development Goals (SDGs), and the African Union Agenda 2063: The Africa We Want. AMCOW reached out to the International Water Management Institute (IWMI) to support the development of such a program. AWaQ builds on the rich experiences and lessons learned from past and ongoing regional and subregional water quality initiatives across Africa by different players, including African Union institutions, and the wider members of the World Water Quality Alliance (WWQA), as well as the AMCOW African Water and Sanitation Sector Monitoring and Reporting System (WASSMO). The five phases of developing an African Water Quality Program (AWaQ) are explained in the following papers: 1. State of Water Quality Monitoring and Pollution Control in Africa (phase 1-2) 2. Innovations in Water Quality Monitoring and Management in Africa (phase 3-4) 3. A Framework for an African Water Quality Program (AWaQ) (phase 5) 4. Country Water Quality Profiles This paper is the first from the above list and is a baseline assessment of the status of water quality monitoring and pollution control in Africa, including the capacities available across countries in the region. This assessment considers various past and ongoing initiatives related to water quality monitoring and management, capacity development, and water pollution control and impact mitigation. Key findings of this paper highlight the following: 1. There is an encouraging availability of national water testing laboratory facilities across African countries. Nonetheless, there are weaknesses that require attention to ensure effectiveness and sustainability. 2. Regular and ongoing training is needed to keep up with laboratory testing methodologies. However, we observed a low trend in regular training, which does not augur well for keeping abreast of the best practices in water quality monitoring. In the context of emerging pollutants, training needs to be more regular than is currently experienced. 3. Water quality monitoring and management capacities are patchy. Capacities related to staff training, laboratory infrastructure and monitoring program activities need strengthening. 4. Pollution control mechanisms are facing challenges. Regulatory mechanisms and wastewater treatment technologies—the most widely deployed pollution control solutions—may benefit from more concerted investment, and the political will and financing to boost their effectiveness.
اظهر المزيد [+] اقل [-]Improved tools for estimation of ammonia emission from field-applied animal slurry: Refinement of the ALFAM2 model and database النص الكامل
2024 | 2025
Hafner, Sasha D. | Pedersen, Johanna | Fuß, Roland | Kamp, Jesper Nørlem | Dalby, Frederik Rask | Amon, Barbara | Pacholski, Andreas | Adamsen, Anders Peter S. | Sommer, Sven Gjedde
Ammonia volatilization from animal slurry applied to agricultural fields reduces nitrogen use efficiency in agriculture and pollutes the environment. This work presents new versions of a model and database focused on this route of N loss. The public ALFAM2 database (https://github.com/AU-BCE-EE/ALFAM2-data) was expanded with ammonia emission and ancillary measurements for >700 additional field plots. The ALFAM2 model (https://github.com/AU-BCE-EE/ALFAM2, https://zenodo.org/records/13312251) was extended with the addition of an ammonia sink for more plausible predictions over extended durations and to better reflect the expected reduction in emission rate several days after slurry application. A new parameter set was developed for the model taking into account the newly available measurement data. Model efficiency improved to 0.67 for the parameter estimation subset (0.52 for cross-validation) and mean absolute error was around 10% of applied total ammoniacal nitrogen. As in earlier versions, predicted emission is sensitive to application method, slurry dry matter and pH, air temperature, and wind speed. A collection of parameter sets for estimating uncertainty in average predictions was developed using a bootstrap approach. Predicted uncertainty is not trivial, and is high for some variable combinations, highlighting the challenge of making predictions based on available measurement data. Still, this work has resulted in more accurate, comprehensive, transparent, and flexible tools for emission inventory and related work on ammonia loss from field-applied slurry.
اظهر المزيد [+] اقل [-]Tree crown condition in 2023 النص الكامل
2024
Timmermann, Volkmar | Potocic, Nenad | Haggenmüller, Katrin | Kirchner, Till | Michel, Alexa K.
Meteorological conditions in European forests in 2022 النص الكامل
2024
Zimmermann, Lothar | Raspe, Stephan | Schütt, Tim | Michel, Alexa K. | Schwärzel, Kai
Forest condition and environmental drivers in Europe - Recent evidence from selected studies النص الكامل
2024
Ferretti, Marco | Vesterdal, Lars | Schaub, Marcus | Schwärzel, Kai | Canullo, Roberto | Cools, Nathalie | De Vos, Bruno | Fleck, Stefan | Gottardini, Elena | Hamberg, Leena | Marchetto, Aldo | Nieminen, Tiina Maileena | Pitar, Diana | Potocic, Nenad | Raspe, Stephan | Rautio, Pasi | Sanders, Tanja G. M. | Schmitz, Andreas | Timmermann, Volkmar | Ukonmaanaho, Liisa | Vejpustková, Monika | Verstraeten, Arne | Waldner, Peter | Wohlgemuth, Lena | Zimmermann, Lothar
Atmospheric deposition in European forests in 2022 النص الكامل
2024
Marchetto, Aldo | Haggenmüller, Katrin | Kirchner, Till | Michel, Alexa K. | Schmitz, Andreas | Verstraeten, Arne | Waldner, Peter
Rubus plicatus Weihe & Nees: resilience to pollution caused by stone quarries النص الكامل
2024
This study aimed to analyze the effect of pollution caused by stone quarries on the morpho-anatomy, biochemistry, and physiology of a medicinal wild bramble Rubus plicatus Weihe & Nees. Samples were collected from two natural protected areas: Iron Gates Natural Park and Jiu Gorge National Park, both located in the southwestern part of Romania, and two unpolluted areas from these parks as background sites. We carried out the following analyses on the collected leaves of this taxon: morphology, micromorphology, anatomy, assimilating pigments, heavy metals (Pb, Ni, Cr, Fe), dry mass, bioactive compounds (total phenols and flavonoids), and antioxidant capacity. The results showed more stomata, higher amounts of assimilating pigments, higher amounts of heavy metals (especially lead), less dry mass, less phenols, and more flavonoids in Rubus plicatus leaves from polluted areas compared to areas without sources of pollution. The increased number of stomata and the amounts of assimilator pigments revealed the mechanisms developed by this species in order to survive in polluted conditions.
اظهر المزيد [+] اقل [-]Ecosystem service research in the dry subtropics: Current state, temporal changes and drivers of regional variability النص الكامل
2024
Dry subtropical (DST) regions that share similar climatic and topographic conditions exhibit today significant disparities in population density, agricultural intensity, wealth and cultural values. In addition, they are also facing increasing pressures on their natural resources. These attributes collectively shape individuals' varying dependence on natural resources and may influence their perception of ecosystem services (ES). In this study, we conducted a systematic literature review, focusing on the DST regions, to address two main questions: 1) What is the current state, temporal trends and regional variability in scientific research on ES and 2) What are the potential drivers of the variability in ES research? Amongst the 471 publications found in our review, 53% focused on provisioning services, followed nearly equally by cultural (33%) and regulating (30%) services. Only 13% addressed more than one ES category and approximately 33% mentioned economic valuation. Our study reveals that research on ES in the dry subtropics experienced a significant increase from 2005 onwards. Approximately 45% of the publications included the term 'ecosystem service' and its frequency has risen substantially over time. Most publications primarily focus on African dry subtropics (over 60%), followed by South and North American ones. Publications from southern Asia and NE Australia were more scarce. Importantly, we found no clear relationship between the number of publications, publication density or representativeness and the variables used as indicators of human pressure (e.g. population density). Consequently, research efforts in the DST regions appear to be influenced by a diverse range of financial and institutional constraints, international research agendas, as well as the personal interests of researchers, contributing to the idiosyncratic nature of this field.
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