Paul Sabatier University - Toulouse III
Recent publications
The Minamata Convention, a global and legally binding treaty that entered into force in 2017, aims to protect human health and the environment from harmful mercury (Hg) effects by reducing anthropogenic Hg emissions and environmental levels. The Conference of the Parties is to periodically evaluate the Convention’s effectiveness, starting in 2023, using existing monitoring data and observed trends. Monitoring atmospheric Hg levels has been proposed as a key indicator. However, data gaps exist, especially in the Southern Hemisphere. Here, we present over a decade of atmospheric Hg monitoring data at Amsterdam Island (37.80°S, 77.55°E), in the remote southern Indian Ocean. Datasets include gaseous elemental and oxidised Hg species ambient air concentrations from either active/continuous or passive/discrete acquisition methods, and annual total Hg wet deposition fluxes. These datasets are made available to the community to support policy-making and further scientific advancements.
We study the random transverse field Ising model on a finite Cayley tree. This enables us to probe key questions arising in other important disordered quantum systems, in particular the Anderson transition and the problem of dirty bosons on the Cayley tree, or the emergence of non-ergodic properties in such systems. We numerically investigate this problem building on the cavity mean-field method complemented by state-of-the art finite-size scaling analysis. Our numerics agree very well with analytical results based on an analogy with the traveling wave problem of a branching random walk in the presence of an absorbing wall. Critical properties and finite-size corrections for the zero-temperature paramagnetic-ferromagnetic transition are studied both for constant (independent of the system volume) and algebraically vanishing (scaling as an inverse power law with the system volume) boundary conditions. In the later case, we reveal a regime which is reminiscent of the non-ergodic delocalized phase observed in other systems, thus shedding some light on critical issues in the context of disordered quantum systems, such as Anderson transitions, the many-body localization or disordered bosons in infinite dimensions.
The identification and characterization of enzyme function is largely lacking behind the rapidly increasing availability of large numbers of sequences and associated high-resolution structures. This is often hampered by lack of knowledge on in vivo relevant substrates. Here, we present a case study of a high-resolution structure of an unusual orphan lipase in complex with an endogenous C18 monoacylglycerol ester reaction intermediate from the expression host, which is insoluble under aqueous conditions and thus not accessible for studies in solution. The data allowed its functional characterization as a prototypic long-chain monoacylglycerol lipase, which uses a minimal lid domain to position the substrate through a hydrophobic tunnel directly to the enzyme’s active site. Knowledge about the molecular details of the substrate binding site allowed us to modulate the enzymatic activity by adjusting protein/substrate interactions, demonstrating the potential of our findings for future biotechnology applications.
The intensification of human activities all around the globe has led to the spread of micropollutants in high-mountain freshwater environments. We therefore aimed to assess the geospatial distribution and determine the potential sources of (total-) mercury (THg) and microplastics (MPs) in mountain freshwater ecosystems. To do so, we analyzed THg and MP concentrations in brown trout, biofilm, and sediments from lotic and lentic ecosystems in the Pyrenees – all subjected to different types of human pressure. Additionally, we assessed the potential impacts of these pollutants on fish, and explored the bioindication capacity of brown trout (Salmo trutta fario) and biofilm regarding THg and MP pollution. For the first time, we measured concentrations of MPs trapped in the matrix of freshwater biofilm. Our results suggest that THg in the Pyrenees might be explained by both legacy (regional) and distant sources, in combination with environmental characteristics such as the presence of peatlands or streamwater physicochemistry, while MPs in fish are linked to recent local pollution sources such as single-use plastics. In contrast, MPs in biofilm matrix and sediments indicate a combination of distant (i.e., atmospheric deposition) and recent local pollution sources. Moreover, hydrodynamics and plastic density likely control MP distribution in rivers. Based on Fulton's condition factor, we also found that higher THg concentrations caused a negative impact on fish health (K < 1), while no impact of MPs could be seen. Therefore, we suggest that brown trout and biofilm can serve as bioindicators of atmospheric deposition of THg in high-altitude lakes and that biofilm is a reliable bioindicator to assess MP pollution in remote environments. Brown trout may also act as a bioindicator of MP pollution, but only efficiently in more polluted areas.
Engagement and well-being are complex phenomena that deeply depend on the individuals themselves and include subjective perception of the past, present, and future experiences. Connecting with work adds a concrete dimension to engagement and well-being that makes it possible to consider designing for and assessing them in a given work context. In the gaming domain, gameful design is known as an efficient mean to increase engagement and well-being. This paper presents an approach to address both engagement and well-being at work and builds on the evolution of the field of HCI over the years to identify means of addressing engagement and well-being. We describe the concepts related to usability and how they evolved towards user experience to encompass more complex (related to self) elements. We show how previous work in the field has connected these major properties (using tasks descriptions) and how it might be possible to extend further embracing human needs and motivation theory. We propose to use gameful design and automation design (via RCRAFT framework) as two contributing disciplines to identify design options for increasing engagement and well-being of users/operators while performing their activities. Application of the framework is given by means of a concrete application building on top of the original Mackworth clock.
Reduction of the magnesium(II) diamide [Mg(TripNON)] (TripNON = 4,5-bis(2,4,6-triisopropylanilido)-2,7-diethyl-9,9-dimethyl-xanthene) with 5% w/w K/KI leads to a good yield of a dianionic dimagnesium(I) species, as its potassium salt, [{K(TripNON)Mg}2]. An X-ray crystallographic analysis shows the molecule to contain a very long Mg‒Mg bond (3.137(2) Å). The formation of [{K(TripNON)Mg}2] contrasts with a previously reported reduction of a magnesium(II) complex incorporating a bulkier diamide ligand, which instead afforded a magnesium-dinitrogen complex. In the current study, [{K(TripNON)Mg}2] has been shown to be a viable reagent for the reductive activation of the catalytically relevant molecules, CO, H2 and N2O.
Anorexia of aging and biological aging might share physiological underpinnings. The aim of this secondary analysis was to investigate the associations between circulating inflammation-related markers and anorexia of aging in community-dwelling older adults. C-reactive protein (CRP), tumor necrosis factor receptor-1 (TNFR-1), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and growth/differentiation factor-15 (GDF-15) were measured in plasma. Anorexia of aging was defined by the response “severe/moderate decrease in food intake” to the first item of the Mini-Nutritional Assessment. We included 463 subjects (median age=74y, IQR=71–78; 63.1% women). 33 subjects (7.1%) presented with anorexia at baseline, whereas 25 out of 363 (6.9%) developed it along 1-year follow-up. We found that TNFR1 (OR=1.74, 95%CI=1.27–2.39) and GDF-15 (OR=1.38, 95%CI=1.01–1.89) were associated with a significant increase in the odds of presenting with anorexia of aging cross-sectionally. No further significant associations were found. Biological aging mechanisms might be involved in the pathogenesis of anorexia of aging.
Zooarchaeological analyses of the skeletal remains of 52 animals unearthed in the courtyard of an Iron Age Tartessian building known as Casas del Turuñuelo (Badajoz, Spain) shed light on a massive sacrifice forming part of a series of rituals linked to the site’s last period of activity and final abandonment. The rites took place towards the end of the 5th century BCE when both the building (intentionally destroyed) and the sacrificed animals were intentionally buried under a tumulus 90 m in diameter and 6 m high. The main objective of the zooarchaeological and microstratigraphic analyses was to determine the phasing of the sacrificial depositions. Evidence gathered from taphonomic assessments and a series of radiocarbon datings indicate that the sacrifices fall into three consecutive phases spanning several years. The findings of the zooarchaeological analyses clearly point to a selection of equid and cattle males. Adult equids predominate (MNI = 41) followed by adult and sub-adult cattle (MNI = 6). Pigs, in turn, are only represented by a few adults and sub-adult females (MNI = 4). Among the animals is a single dog of undetermined sex between 3 and 4 years of age. The fact that the animals are mostly adults discards the likelihood that they died from natural causes or an epidemic. In addition, the scenographic deposition of certain equids in pairs, as well as evidence of the burning of plant offerings, suggest an intentional ritualistic sacrifice. Nine of the initial depositions of Phase 1 in the SE quadrant were scattered and certain of their bones bear marks characteristic of both prolonged open air exposure and scavengers. Another 31 animals from Phases 1 and 2 are represented by almost complete, articulated skeletons, indicating they were promptly covered. Phase 3, by contrast, reveals both almost complete and partial animals bearing clear signs of processing for human consumption. This study thus sheds light on both the sequence of the animal sacrifices and the protocols linked to rites accompanied by the celebration of banquets. Certain features associated with the sealing of this building under a tumulus offer evidence of the decline of the Tartessian Culture. This study thus advances notions serving to contextualize ritual animal sacrifices in the framework of practice observed at other Iron Age sites in the Iberian Peninsula and elsewhere throughout Europe.
The current focus of river restoration on flow and sediment transfer without proper consideration of vegetation as a key structuring agent, beyond its stabilising effect, is too simplistic. We contend that vegetation has an essential role in shaping the physical fluvial environment and should be considered equally alongside hydrogeomorphic processes in restoration projects. In support, we introduce engineer plants as important controls, along with flowing water and transported sediments, on the morphodynamics of river systems and associated physical habitat development. The effect of vegetation on channel planform is then summarised, the influence of vegetation on hydrogeomorphic connectivity is outlined, and then the role of vegetation in landform development and habitat provision, as encapsulated in the fluvial biogeomorphic succession model, is described. We then present examples demonstrating how vegetation has contributed to the recovery of degraded rivers through biogeomorphic processes. Finally, we advance the concept of biogeomorphic river restoration by proposing principles to support a closer synthesis of the component sciences and list key areas for practitioners to focus on.
Atherosclerosis is the primary cause of cardiovascular disease. The development of plaque complications, such as calcification and neo-angiogenesis, strongly impacts plaque stability and is a good predictor of mortality in patients with atherosclerosis. Despite well-known risk factors of plaque complications, such as diabetes mellitus and chronic kidney disease, the mechanisms involved are not fully understood. We and others have identified that the concentration of circulating leucine-rich α-2 glycoprotein 1 (LRG1) was increased in diabetic and chronic kidney disease patients. Using apolipoprotein E knockout mice (ApoE−/−) (fed with Western diet) that developed advanced atherosclerosis and using human carotid endarterectomy, we showed that LRG1 accumulated into an atherosclerotic plaque, preferentially in calcified areas. We then investigated the possible origin of LRG1 and its functions on vascular cells and found that LRG1 expression was specifically enhanced in endothelial cells via inflammatory mediators and not in vascular smooth muscle cells (VSMC). Moreover, we identified that LRG1 was able to induce calcification and SMAD1/5-signaling pathways in VSMC. In conclusion, our results identified for the first time that LRG1 is a direct contributor to vascular calcification and suggest a role of this molecule in the development of plaque complications in patients with atherosclerosis.
Many threatened species require ongoing management, which is often funded through short project cycles. Evaluating whether the management is effective in protecting a species is important to inform future management investments. For migratory species, management may affect only part of a species' annual cycle, and reversing a population decline is challenging to achieve and demonstrate. Here, we evaluate whether conservation management projects funded by the European LIFE programme to safeguard a migratory vulture population achieved their major objective of stabilizing the target breeding population. Between 2012 and 2022, an international alliance of conservation organizations implemented multiple actions to reduce poisoning, direct persecution, and electrocution and collision with power lines along the Eastern Mediterranean flyway. We monitored breeding territories of the Balkan population of the globally endangered Egyptian Vulture Neophron percnopterus between 2006 and 2022, and tracked 60 young birds with GPS transmitters since 2010. We used these data to examine whether population growth rate and survival probability had increased since project implementation. The mean annual survival probability of adult territorial birds increased by 1.9% since 2014 from 0.937 to 0.955, and the monthly survival probability of wild juvenile birds increased by 9.7% from 0.833 to 0.914 since 2018. The population growth rate across the Balkans increased by 6.9% from 0.939 before 2018 to 1.005 since 2018. This indicates that the Egyptian Vulture population has remained stable for the past 5 years (2018–2022), but at a population size that is only half (105 adult territorial birds in 2022) than at the beginning of the time series (204 in 2006). We caution that ongoing management along the flyway and reinforcement are required to ensure that the Egyptian Vulture population on the Balkans can recover, but we show that flyway‐scale collaboration of direct conservation actions can have lasting benefits for migratory species.
Provenance calculus has been introduced, about fifteen years ago, for complementing relational algebra calculations in databases, with semiring operations in order to handle data lineage, incomplete or probabilistic information. Possibilistic logic has started to be developed twenty years before, initially for dealing with epistemic uncertainty, using the max-min semiring. Since then, several variants and generalizations of possibilistic logic have been proposed, involving various semirings. All these forms of possibilistic logic are surveyed and paralleled with provenance calculus, through logical counterparts of relational algebra operations. The paper ends with a discussion of the parallel between the two research trends.
This paper deals with belief change in the framework of Dempster-Shafer theory in the context where an agent has a prejudice, i.e., a priori knowledge about a situation. This situation is modeled as a sequence (p, m) where p reflects the prejudices of an agent and m is a mass function that represents the agent’s uncertain beliefs. In contrast with the Latent Belief Structure introduced by Smets where a mass is decomposed into a pair of separable mass functions called respectively the confidence and diffidence, m can be any mass function (i.e., not necessarily separable) and p is not a mass. The aim of our study is to propose a framework in which the evolution of prejudices and beliefs are described through the arrival of new beliefs. Several cases of prejudice are described: the strong persistent prejudice (which never evolves and forbids beliefs to change), the prejudice that is slightly decreasing each time a belief contradicts it, etc.
Logical proportions are a type of propositional connector that involves four variables, expressed as a formula that encodes the conjunction of two equivalences. These equivalences refer to indicators of similarity or dissimilarity between two ordered pairs of variables, say (a, b) and (c, d). An example of a logical proportion is the analogical proportion, which is of the form: “a is to b as c is to d”. The concept of logical proportion is used here to develop a logic that deals with ordered pairs of (vectors of) variables. In particular, we outline a logic of change which controls how the differences inside ordered pairs can be logically combined and propagated via a consequence relation between pairs of vectors.
Citation: Dadouche, N.; Mezache, Z.; Tao, J.; Ali, E.; Alsharef, M.; Alwabli, A.; Jaffar, A.; Alzahrani, A.; Berazguia, A. Design and Fabrication of a Novel Corona-Shaped Abstract: The early detection and diagnosis of cancer presents significant challenges in today's healthcare. So, this research, suggests an original experimental biosensor for cell cancer detection using a corona-shaped metamaterial resonator. This resonator is designed to detect cancer markers with high sensitivity, selectivity, and linearity properties. By exploiting the unique properties of the corona metamaterial structure in the GHz regime, the resonator provides enhanced interaction of electromagnetic waves and improved detection skills. Through careful experimental, simulation, and optimization studies, we accurately demonstrate the resonator's ability to detect cancer. The proposed detection system is capable of real-time non-invasive cancer detection, allowing for rapid intervention and better patient outcomes. The sensitivity value was confirmed through simulation, estimated at 0.1825 GHz/RIU. The results of two different simulation methods are used: the simulation software CST Studio Suite (version 2017) based on the finite element method (FEM), and the simulation software ADS (version 2019) based on the equivalent circuit method, thereby increasing confidence in the convergence of simulation and measurement results. This work opens new avenues for developing advanced detection technologies in the field of oncology, and paves the way for more effective cancer diagnosis. The experimental study verified that this realized sensor has very small frequency shifts, significantly small electrical dimension and miniaturization, high sensitivity, and good linearity. The suggested configurations showed a capacity for sensing cancer cells in the GHz regime.
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6,088 members
Dominique Agustin
  • IUT Paul Sabatier
Stéphane Audry
  • Laboratoire Géosciences Environnement Toulouse - UM 97 (UMR 5563 / UMRD 234) - GET
Ion Nechita
  • Laboratoire de Physique Théorique - UMR 5152 - LPT
Patrick J. Sharrock
  • Département de Chimie IUT
Patrick moretto-capelle
  • Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes - FR 2568 - IRSAMC
Toulouse, France