The benthic foodweb structure of Lake Võrtsjärv, a large (270 km2), shallow, and turbid Estonian lake, was evaluated based on C and N stable-isotope signatures (δ13C, δ15N). Variation in δ13C between ...sampling sites was not related to site proximity to the littoral zone or the more vegetated southern part of the lake, but rather appeared to be influenced by in-situ site peculiarities. δ13C was stable temporally and between functional feeding groups, a result implying that the whole benthic food web of the lake relies largely on the same C source admixture, essentially particulate organic matter (POM). Thus, the foodweb composition of Lake Võrtsjärv is remarkably homogeneous given the lake’s large surface area. Apparent trophic-level δ15N fractionation between total collectors and total predators (mean 1.7‰) was lower than the value of 3.4‰ generally adopted in foodweb studies, but the higher value was valid for specific prey–predator links. The low δ13C signature of some chironomid samples indicated probable assimilation of methane-oxidizing bacteria (MOB) by these sediment-dwelling invertebrates. However, the lack of similar13C depletion in benthic filterers (mussels) indicated that the MOB layer is essentially confined to the sediments and does not reach the water column, which probably constrains transfer of methane-derived C through the food web to fish in this lake. Our study demonstrates that the benthic food web of shallow turbid lakes like Võrtsjärv is simplified and is mostly sustained by phytoplanktonic C sources.
The triple crises of the COVID-19 pandemic, conflict and climate change have severely impacted food systems, leading to socio-economic consequences and undermining food and nutrition security across ...Africa. To address the malnutrition and poverty affecting approximately 700 million people in Africa, there is potential for the One Health approach implementation and operationalization to bring together multidisciplinary solutions for tackling food insecurity and ensuring food safety net. However, there is limited documentation on the potential of the One Health approach system thinking implementation to guide responses to triple crises-induced food insecurity. Therefore, this article aims to systematically understand the triple crises-induced food insecurity, connect existing solutions, and explore the role of the One Health approach in strengthening food and agriculture systems in Africa.Our finding showed the impact of triple crises exacerbating food system vulnerability in Africa and worldwide. Mitigating and resilient actions are urgently needed in tackling the emerging and persisting challenges, and infectious diseases menace and burden across Africa. We present a conceptual model illustrating the complex nature of triple crises-induced food insecurity, vulnerability areas within the food system, and actionable strategies for building community food resilience. Additionally, recommendations are provided to create an enabling environment that supports One Health approach implementation and addresses food insecurity challenges through innovative partnerships, local-led initiatives, and enhanced governance and artificial intelligence technology capacities in achieving sustainable and inclusive growth to reduce socio-economic inequalities.Stepping up integrated, actionable, and sustainable food systems programs and innovative long-lasting solutions requires investing in promoting new partnership and research collaboration in building conflict resolution and peace towards strengthening and reshaping local and global food security related climate change adaptations actions for most vulnerable communities’ benefits. These are ingredients in fastening preparedness, prevention and control of infectious diseases prevention and control, reducing food supply chains disruption towards accelerating equitable benefits of Universal Health Coverage and Sustainable Development Goals, 2030 across Africa.
To study the role of large and shallow hemiboreal lakes in carbon processing, we calculated a 3-year carbon mass balance for Lake Võrtsjärv (Estonia) based on in situ measurements. This balance took ...into account hydrological and biogeochemical processes affecting dissolved inorganic (DIC), dissolved organic (DOC) and particulate organic (POC) carbon species. Accumulation varied greatly on a seasonal and yearly basis. The lake exported carbon during most of the year except during spring floods and in late autumn. In-lake processes were responsible for exporting POC and storing DOC while DIC switched between storage and export. The carbon cycle was alternatively dominated in 2009 by biogeochemical processes and in 2011 by riverine fluxes, whereas in 2010 the two process types were of the same magnitude. These results suggest that the role of large shallow lakes like Võrtsjärv in the global C cycle is equally driven by hydrological factors, in particular seasonal water level changes, and by biogeochemical in-lake reactions.
This paper presents a probability-based approach for optimising the management of bridge networks. Most of the Bridge Management Systems are focused on condition features to ensure a minimum safety ...level for each individual bridge. Their location on the road network, the consequences of inadequate service due to maintenance actions are therefore not taken into consideration. These multiple criteria should be considered when scheduling maintenance activities. To overcome these limitations, a probabilistic supply and demand strategy is proposed for determining the optimal maintenance planning for each interconnected bridge. The problem is solved with genetic algorithms. One objective function is first introduced, corresponding to the summation of all the maintenance, failure, and user costs. Then, two conflicting objective functions are considered, the total user costs and the maintenance and rehabilitation costs. Safety and serviceability aspects are taken into account in the methodology and the theoretical and numerical developments are applied on a part of the French national network.
After several years of operation, some structures and components show distress, which may increase their vulnerability and reduce their level of service and safety for users. A risk-based methodology ...is a powerful tool to achieve certain strategic choices when resources are not extensible (e.g., for the management of a stock of existing structures, or their upgrade, to respond to a particular risk, such as a seismic or climate change risk). Risk analysis also allows for the definition of a strategy to monitor and inspect or to prioritize upgrade actions (e.g., to repair, strengthen). In this sense, risk analysis alone is necessary but is not sufficient: it must precede the decision as part of an overall risk management process. This paper presents risk analysis methodology and its application to two families of structures developed and implemented by the French Ministry of Ecology, Sustainable Development, and Energy (in charge of transportation) on the national road network of France.
Summary
Background The chromosome 9p21 and its CDKN locus, with the p16 tumour suppressor gene (CDKN2A), are recognized as the genomic regions involved in the pathogenesis of melanoma.
Objectives ...To elucidate further the role of such regions during the different phases of melanocytic tumorigenesis.
Methods Tissue sections from naevi, primary and metastatic melanomas were investigated by fluorescence in situ hybridization for allelic loss at the 9p21 chromosome and by immunochemistry for p16CDKN2A expression.
Results Dysplastic naevi and primary or secondary melanomas were found to carry hemizygous deletions within the entire 9p21 region at similar frequencies (varying from 55% to 62%). Allelic deletion spanning the CDKN locus was observed at significantly increased rates moving from early (7%) to advanced (28%) primary melanomas and to secondary melanoma lesions (37%) (P = 0·018). Also, inactivation of the p16 gene (CDKN2A) was absent in naevi and present at steadily increasing rates moving from primary melanomas (7% early lesions to 17% advanced lesions) to melanoma metastases (62%) (P = 0·004).
Conclusions Our findings indicate that, in a model of sequential accumulation of genetic alterations, 9p21 deletions may play a role in melanocytic transformation and tumour initiation whereas rearrangements at the CDKN locus, and p16 gene (CDKN2A) inactivation may contribute to tumour progression.
For managing highway bridges, stakeholders require efficient and practical decision making techniques. In a context of limited bridge management budget, it is crucial to determine the most effective ...breakdown of financial resources over the different structures of a bridge network. Bridge management systems (BMSs) have been developed for such a purpose. However, they generally rely on an individual approach. The influence of the position of bridges in the transportation network, the consequences of inadequate service for the network users, due to maintenance actions or bridge failure, are not taken into consideration. Therefore, maintenance strategies obtained with current BMSs do not necessarily lead to an optimal level of service (LOS) of the bridge network for the users of the transportation network. Besides, the assessment of the structural performance of highway bridges usually requires the access to the geometrical and mechanical properties of its components. Such information might not be available for all structures in a bridge network for which managers try to schedule and prioritize maintenance strategies. On the contrary, visual inspections are performed regularly and information is generally available for all structures of the bridge network. The objective of this paper is threefold (i) propose an advanced network-level bridge management system considering the position of each bridge in the transportation network, (ii) use information obtained at visual inspections to assess the performance of bridges, and (iii) compare optimal maintenance strategies, obtained with a genetic algorithm, when considering interests of users and bridge owner either separately as conflicting criteria, or simultaneously as a common interest for the whole community. In each case, safety and serviceability aspects are taken into account in the model when determining optimal strategies. The theoretical and numerical developments are applied on a French bridge network.
This paper describes the experimental investigations and the planned rehabilitation program for the Teil Bridge, which connects the cities of Le Teil and Montέlimar in the Rhône–Alpes region of the ...Ardèche Department of France. Soon after the sudden rupture of a strand near the anchorage, the bridge was closed to traffic. Inspections were conducted to understand the causes of this event and to assess the strength of cables and strand sockets. Before the bridge was rehabilitated, its safety was improved through the strengthening of each socket. The bridge was then reopened to pedestrians and cyclists only. An acoustic emission system was installed over the course of a year. Events related to cable ruptures were monitored accordingly. Meanwhile, several other experimental investigations were conducted on steel and concrete materials (i.e., resilience, tensile steel strength, carbonation, chloride ingress) to estimate the residual structural service life of the bridge and to plan repair actions. A major rehabilitation program was then scheduled to change all of the cables and sockets. This paper presents stages of the investigation and the rehabilitation process.
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