Université Côte d'Azur
Recent publications
Introduction: On 2 October 2020, a violent storm (Alex) reached the French Riviera and caused significant damage in three inhabited valleys in the hinterland of the city of Nice. Entire populations were exposed to prolonged stress (no means of communication, electricity nor water) and were particularly at risk of suffering from psychological consequences. We first hypothesized that a majority of children would experience an acute stress reaction. However, we also hypothesized that their clinical expression would differ depending on their developmental age. Thus, we aimed to evaluate, according to the child's level of development, the presence of acute stress symptoms. Methods: Consecutive interviews with the child/adolescent and his/her parents were conducted by child and adolescent psychologists and psychiatrists to assess symptomatology following storm Alex (from day 1 to day 3). Each interview assessed nine classes of symptoms that have been compared according to age-groups. Results: 116 children have been evaluated (0.2-17.6 years, mean 9.1). The 0-5-years-old showed more agitation as well as developmental regression than children aged 6-11 (p = .011, p = .045) and 12-18 years (p < .001, p < .001). Anxiety was reported more frequently among the 6-11 years old than the 0-5 years children (p = .018). Overall, the interviewed children presented at least one manifestation of acute stress after the storm (94% for the 0-5 years; 83% for the 6-11 years and 74% for the 12-18 years). Discussion: The results highlight the high rate of acute stress symptoms in a natural disaster context, their specificity depending on children's age. Therefore; it emphasizes the need to develop, improve and validate specific assessment tools. Scheduled follow-up evaluations will help to understand, after a natural disaster, the long-term stress response in children, paving the way for targeting early, intensive, specific and multidisciplinary symptomatic treatment approaches.Trial registration: ClinicalTrials.gov identifier: NCT04850924. Highlights: Acute stress symptoms in children and adolescents are very frequent in the context of exposure to a natural disaster with specifications depending on the developmental age.
Background Migraine is responsible for significant disability and societal burden. Recently, drugs targeting the calcitonin gene-related peptide (CGRP) pathway raised new hopes. CGRP, a potent vasodilator, plays a key role in the pathogenesis of migraine attacks. The deficiency of CGRP is involved in Raynaud’s phenomenon, which consists of abnormal vasoconstriction of the digits. We aimed to assess the potential association of Raynaud’s phenomenon with CGRP-targeting drugs, analyzing real-world data from the World Health Organization (VigiBase®). Methods We queried all reports of Raynaud’s phenomenon involving a CGRP-targeting drug. We sought disproportionate reporting of Raynaud’s phenomenon with these drugs. For this purpose, we relied on the calculation of the Information Component (IC). A positive lower end of the 95% confidence interval (CI) of the IC defines a statistically significant association. As migraine patients are prone to Raynaud’s phenomenon, we also calculated the IC of Raynaud’s phenomenon with CGRP-targeting drugs compared to 5HT1 B/D agonists (triptans), and beta-blockers used in the treatment of migraine. Results Overall, 99 reports of Raynaud’s phenomenon involving CGRP-targeting drugs have been yielded in VigiBase®. The most reported CGRP-targeting drug was erenumab, with 56 reports (56.6%). The median time to onset was 84 days. No fatality was notified, but one patient suffered from gangrene and extremity necrosis. As a whole, CGRP-targeting drugs were significantly associated with Raynaud’s phenomenon, with an IC of 3.3 (95%CI: 3.0–3.5). There was a disproportionate reporting of Raynaud’s phenomenon with CGRP-targeting drugs compared to triptans (IC 0.4; 95%CI: 0.1–0.6) and to beta-blockers (IC 0.5; 95%CI: 0.2–0.7) as well. Conclusions There is a significant disproportionality signal of Raynaud’s phenomenon with CGRP-targeting. This signal stands out when CGRP-targeting drugs are compared to other drugs used in patients with migraine. This study is limited by missing data in pharmacovigilance reports. CGRP-targeting drugs may be subject to Weber effect and reporting bias. Nonetheless, CGRP blockade might be the last straw that disrupts the physiological balance of vascular response in patients at-risk of Raynaud’s phenomenon. Pending further data regarding vascular safety of CGRP-targeting drugs, caution is warranted in these patients.
Background Stress hyperglycemia can persist during an intensive care unit (ICU) stay and result in prolonged requirement for insulin (PRI). The impact of PRI on ICU patient outcomes is not known. We evaluated the relationship between PRI and Day 90 mortality in ICU patients without previous diabetic treatments. Methods This is a post hoc analysis of the CONTROLING trial, involving 12 French ICUs. Patients in the personalized glucose control arm with an ICU length of stay ≥ 5 days and who had never previously received diabetic treatments (oral drugs or insulin) were included. Personalized blood glucose targets were estimated on their preadmission usual glycemia as estimated by their glycated A1c hemoglobin (HbA1C). PRI was defined by insulin requirement. The relationship between PRI on Day 5 and 90-day mortality was assessed by Cox survival models with inverse probability of treatment weighting (IPTW). Glycemic control was defined as at least one blood glucose value below the blood glucose target value on Day 5. Results A total of 476 patients were included, of whom 62.4% were male, with a median age of 66 (54–76) years. Median values for SAPS II and HbA1C were 50 (37.5–64) and 5.7 (5.4–6.1)%, respectively. PRI was observed in 364/476 (72.5%) patients on Day 5. 90-day mortality was 23.1% in the whole cohort, 25.3% in the PRI group and 16.1% in the non-PRI group ( p < 0.01). IPTW analysis showed that PRI on Day 5 was not associated with Day 90 mortality ( IPTW HR = 1.22; CI 95% 0.84–1.75; p = 0.29), whereas PRI without glycemic control was associated with an increased risk of death at Day 90 ( IPTW HR = 3.34; CI 95% 1.26–8.83; p < 0.01). Conclusion In ICU patients without previous diabetic treatments, only PRI without glycemic control on Day 5 was associated with an increased risk of death. Additional studies are required to determine the factors contributing to these results.
Background: The prognostic value of extravascular lung water (EVLW) measured by transpulmonary thermodilution (TPTD) in critically ill patients is debated. We performed a systematic review and meta-analysis of studies assessing the effects of TPTD-estimated EVLW on mortality in critically ill patients. Methods: Cohort studies published in English from Embase, MEDLINE, and the Cochrane Database of Systematic Reviews from 1960 to 1 June 2021 were systematically searched. From eligible studies, the values of the odds ratio (OR) of EVLW as a risk factor for mortality, and the value of EVLW in survivors and non-survivors were extracted. Pooled OR were calculated from available studies. Mean differences and standard deviation of the EVLW between survivors and non-survivors were calculated. A random effects model was computed on the weighted mean differences across the two groups to estimate the pooled size effect. Subgroup analyses were performed to explore the possible sources of heterogeneity. Results: Of the 18 studies included (1296 patients), OR could be extracted from 11 studies including 905 patients (464 survivors vs. 441 non-survivors), and 17 studies reported EVLW values of survivors and non-survivors, including 1246 patients (680 survivors vs. 566 non-survivors). The pooled OR of EVLW for mortality from eleven studies was 1.69 (95% confidence interval (CI) [1.22; 2.34], p < 0.0015). EVLW was significantly lower in survivors than non-survivors, with a mean difference of -4.97 mL/kg (95% CI [-6.54; -3.41], p < 0.001). The results regarding OR and mean differences were consistent in subgroup analyses. Conclusions: The value of EVLW measured by TPTD is associated with mortality in critically ill patients and is significantly higher in non-survivors than in survivors. This finding may also be interpreted as an indirect confirmation of the reliability of TPTD for estimating EVLW at the bedside. Nevertheless, our results should be considered cautiously due to the high risk of bias of many studies included in the meta-analysis and the low rating of certainty of evidence. Trial registration the study protocol was prospectively registered on PROSPERO: CRD42019126985.
The objective of this work is to study the propagation of a premixed flame through numerous obstacles and to observe the flame/obstacle interactions. Several premixed flame models have been evaluated using the OpenFoam software library. They are all based on the evolution of the progress variable and they take into account the increase of the flame speed due to the effects of folding and stretching due to the turbulence. The studied configuration is based on the expansion of a spherical flame within a network of obstacles whose spherical geometry allows fine statistical analyses along the radial direction of the geometry. Various analyses have been carried out based on the temporal evolution of the flame, on the geometric position of its front and finally on the statistical data of its structure. At a given level of turbulence and for an equal volume obstruction rate, whatever the arrangement of the obstacles, it appears that the flame surface developed over time remains substantially identical even if its local topology is very different. On the other hand, if the volume of obstructions varies, the flame surface and therefore its propagation speed is strongly affected. Different correlations for turbulent combustion models have been used: Gulder, FLACS and Zimont. These are the most used in the most common industrial CFD codes. It has been observed that, by properly adjusting the parameters associated with each model, an identical free flame velocity can be found by each model, however, as soon as the flame crosses obstacles, significant variations are observed. This is a logical observation since these models were developed for flame propagation without obstacles. But it seems necessary to consider extensions of these models that would take into account the presence of a given volume obstruction rate.
In this paper, we review and discuss the main properties of the time-reversal operator T and its action in classical electromagnetism and in quantum mechanics. In particular, we discuss the relation (and differences) between time-reversal invariance and reciprocity.
In the ice-infested Arctic Ocean environment, the uptake of new sea ice services is an important factor in ensuring safe and efficient marine operations. Producers increasingly turn to co-production for user input, similar to the wider field of climate services. This paper asks how the uptake of sea ice information services can be optimized, by gauging the extent to which producers and users already share an understanding of how trust develops toward new products. By adopting a consensus analysis approach, we gain insights about how to balance further investments in knowledge co-production versus change implementation. We chose cultural consensus analysis, a method that produces valid estimates even in small sample sizes. Our survey presented thirty-two propositions based on seven dimensions of trust in weather, water, ice and climate services. The survey was completed by fifty-seven respondents (n = 29 users, n = 28 producers) and revealed a strong consensus model among the two groups about the necessary improvements needed to increase users’ trust in new services. Our results suggest that forecast producers for the Arctic region, specifically in the field of specialized sea ice predictions and mapping/charting, share a substantial understanding with users about how trust develops toward new products. We discuss the importance of automation, peer endorsement and perceptions of cost-performance ratio for necessary strategic approaches to help experienced forecast users to trust and adapt products to their specific operational context, and reflect on the costs associated with the use of specialized sea ice services in closing the usability gap.
Biomass feedstocks are playing a crucial role toward the development of new sustainable materials with the aim to replace the fossil-based ones limiting the emissions and waste. Among the other, cellulose, and hemicellulose are gaining interest as a source of new bio-based building blocks such as furan derivatives. In this study, two furan derivatives were selected as bio-based monomers to design four innovative UV-curable coatings. Specifically, 2,5-Furandimethanol (FDM), and cis-cyclobutane-1,2-dicarboxylic acid (CBDA-2) derived from Furylacrylic acid were modified by allylation of their respective OH groups. The bis allyl derivatives were combined with commercial tris- and tetra-functional thiols compounds and cured by means of UV-light through a thiol-ene reaction. The UV-curing was deeply investigated by means of real-time FT-IR, photo-DSC and photorheology. Successively, the bio-based thermosets were characterized by DMTA and tensile test to examine the thermal-mechanical behavior. The results indicated comparable properties with previous studied bio-based thiol-ene thermoset raising the possibility to use the studied material for coating applications.
The aim of this paper is to improve our understanding of the roles of individuals and the importance of their social contexts in shaping the dynamics of technological diffusion in the agricultural sector. When justifying the different rates of innovation adoption, existing literature reviews overemphasize either the drivers of technological changes enacted by farmers' agentic behaviour or the cognitive processes of individual farmers and their social contexts (structures). However, they continue to have a fragmented view of how local social systems and the agentic behaviour of individual actors influence the evolution of technological regimes, and they lack the ability to describe a purposeful interplay between agency and structures. We present an integrative review of the most relevant papers published in the last 20 years and discuss the impact of structures and agency emerging from local social systems on the local innovation process and, as a result, the evolution of technological regimes. The identified macro categories describe the main processes affecting individuals' abilities to mobilize and manage local resources for innovation, allowing us to critically assess the stock of previous developments from a new perspective and identify novel research avenues.
The modeling of dependence between maxima is an important subject in several applications in risk analysis. To this aim, the extreme value copula function, characterized via the madogram, can be used as a margin-free description of the dependence structure. From a practical point of view, the family of extreme value distributions is very rich and arise naturally as the limiting distribution of properly normalized component-wise maxima. In this paper, we investigate the nonparametric estimation of the madogram where data are completely missing at random. We provide the functional central limit theorem for the considered multivariate madrogram correctly normalized, towards a tight Gaussian process for which the covariance function depends on the probabilities of missing. Explicit formula for the asymptotic variance is also given. Our results are illustrated in a finite sample setting with a simulation study. Our method is also illustrated on a sparse dataset of annual maxima rainfall in Central Eastern Canada.
Parkinson's disease is the second most prevalent neurodegenerative disease after Alzheimer's disease, mostly happened in the elder population and the prevalence gradually increased with age. Parkinson’s disease is a movement disorder that severely affects patients’ daily life. The mechanism of Parkinson’s disease still remains unknown, however, studies already proved that the damage or absence of dopaminergic neurons located in the substantia nigra and the decreased dopamine in the striatum are significantly related to Parkinson’s disease. To date, the mainstream treatment of Parkinson's disease has been achieved by alleviating its associated morbid symptoms, such as the use of levodopa, carbidopa, dopamine receptor agonists, monoamine oxidase type B inhibitors, anticholinergic drugs, etc. However, strong side effects, even toxicity, have been reported after using these drugs, with reduced effectiveness over time. Plant compounds have shown good therapeutic effects in neurodegenerative diseases as a less toxic treatment. In this review, we have compiled several natural plant compounds and classified the currently reported compounds for therapeutic use based on their structural parent nuclei and constituent elements. We wish to inspire new ideas for the treatment of Parkinson's disease by summarizing their mechanisms.
At subduction zones, fluid circulation and elevated pore pressure are key factors controlling the seismogenic behavior along the plate interface by reducing absolute fault strength, increasing the time return of high magnitude co-seismic rupture and favoring aseismic slip. The Lesser Antilles is an end-member subduction zone where the slow subduction of numerous trans-oceanic fracture zones and patches of pervasively fractured, hydrated and serpentinized exhumed mantle rocks increase the water input. Heat-flow variations measured in the trench and the forearc during the Antithesis 1 cruise reveal heat advection by fluid circulation and shed a new light onto the thermal control of seismicity location in the subduction zone. In the Northern Lesser Antilles, heat-flow anomalies, negative in the trench and positive in the forearc, reveal a ventilated fluid circulation with downward percolation of cold fluids at the sediment-starved, pervasively fractured trench and upward discharge of warm fluids through the Tintamarre Fault Zone in the forearc. In contrast, in the Central Lesser Antilles, a positive heat-flow anomaly at the trench and the accretionary wedge is typical of an insulated fluid circulation where warm fluids invade the plate interface flowing updip from the subduction depths up to the trench. The investigated margin segments correspond with a very low number of interplate thrust earthquakes, illustrating the frequent statement that fluids in subduction zones tend to reduce the interplate coupling, favor slow to aseismic slip behavior, and increase the time return of large seismic events. Moreover, the location of intraslab, and supraslab earthquakes at depth beneath the Central Lesser Antilles suggest a close relation to temperature-related dehydration reactions.
In cases of criminal dismemberment, the analysis of saw marks helps to determine the class of the saw used. The present study compared the microscopic features of experimental false starts performed on three freshly defleshed human femurs. 150 lesions were produced using three reciprocating blades and two hand saws of similar class. Two groups of tools were created according to the class of the blades: group 1 (teeth per inch = 6, alternating set) and group 2 (teeth per inch = 24, wavy set). The minimum width of the kerf was always thicker with reciprocating blades than that of the handsaw of the same class. This fact is linked to the thickness of the blades and not necessarily to the fast forth and back motion of the blades. Shape kerf profiles and shape of the walls were very confusing, with a lot of variation of the false starts caused by the reciprocating blades and the risk of misclassification (rip teeth versus crosscut teeth, alternating set versus wavy set). Striae on the kerf floor and bone islands were more consistent. The main conclusions are, first, that usual features of false starts achieved by reciprocating saw blades used in this work vary a great deal and may lead to misclassification of the saw class, and second, that no criterion has been found to differentiate reciprocating blades and handsaws. These results demonstrate that we have to be very prudent while estimating the possible saw from a false start in a real forensic case.
This article examines the self-production of washable and reusable sanitary masks during the early stages of the COVID-19 pandemic by focusing on the varied concerns, skills, and material resources that people mobilized. Based on hundreds of testimonials gathered at three key moments of the pandemic in France, we describe mask-self production as a “flash practice.” The immediate life-threatening context put the focus on basic and short-term concerns at the expense of other aspects (such as care for the environment, which played a surprisingly inconsequential role). Nonetheless, this household-based practice quickly evolved into a more collective undertaking with masks being self-produced together by sharing patterns and standards and by donating masks to others. We also show that the practice vanished very fast, as commercial masks became available again. Because flash practices disappear and can quickly fall into oblivion, we hold that researchers need to document and theorize them carefully, for flash practices raise important questions about the temporality, sustainability, and routinization of concerned practices.
We analyze the implications of geographical heterogeneities and externalities on health and macroeconomic outcomes by extending a basic epidemiological‐macroeconomic model to a spatial dimension. Because of people's migration and commuting across different regions, a disease may spread also in areas far from those in which the outbreak originally occurs and thus the health status (i.e., disease prevalence) in specific regions may depend on the health status in other regions as well. We show that neglecting the existence of cross‐regional effects may lead to misleading conclusions about the long run outcome not only in single regions but also in the entire economy, suggesting that single regions need to coordinate their efforts to achieve disease eradication. We analyze such a coordination by focusing on a control problem in which the social planner determines globally the level of intervention showing that to achieve eradication it is essential to accompany traditional disease control policies (i.e., prevention and treatment) with regulations limiting people's movements. Focusing on COVID‐19 we present a calibration based on Italian data showing that, because of the infections generated by cross‐regional commuting, even vaccination may not be enough to achieve disease eradication, and limitations on people's movements need to accompany vaccination to preclude COVID‐19 from reaching an endemic state.
Due to the importance of exporting for firm survival and growth, this study aims to provide new insights into what impedes SMEs in emerging countries from exporting. To do this, we view export barriers as a configurational phenomenon and focus on the SMEs’ decision not to export from an emerging country to other emerging countries. This helps us capture the causal complexity surrounding the more fundamental SME export obstacles in emerging countries. We apply the fuzzy set Qualitative Comparative Analysis to a unique dataset of private manufacturing Russian SMEs. Our results highlight the importance of equifinality and complementary relationships between conditions relating to internal resources, relational assets, and home market context to understand export barriers. We also find that both the presence and the absence of a given condition (e.g., firm age or industry corruption) can be associated with non-export, which could explain contradictory findings in the extant export literature.
Nowadays, biomass-derived monomers production and thermosets’ recyclability are the two main efforts in the development of sustainable thermosetting epoxy resins to replace fossil derivatives and mitigate landfill build-up and ecological impact. Here, we propose a simple step and benign synthesis strategy by using the itaconic acid (IA) and two epoxidized vegetable oils (EVOs), linseed and soybean, in order to obtain fully bio-based materials with high carbon bio-content. The reactivity of these formulations, together with the properties of obtained thermosets were investigated and compared with that of DGEBA/IA homologous system. The EVOs/IA reactive mixtures show high reactivity, tested by differential scanning calorimetry (DSC) and Fourier-transformed infrared spectroscopy (FT-IR) while the obtained resins display good mechanical properties, high thermal stability as well as resistance to solvents. Due to the transesterification reaction in the polyester-based networks, recycling abilities tested both mechanically and chemically were proven. The fully reprocessed bio-based thermosets displayed almost unchanged thermomechanical properties and chemical structure combined with a simple and green chemical processing.
Active remote sensing by laser scanning (LiDAR) has markedly improved the mapping of a cave environment with an unprecedented level of accuracy and spatial detail. However, the use of laser intensity simultaneously recorded during the scanning of caves remains unexplored despite it having promising potential for lithological mapping as it has been demonstrated by many applications in open-sky conditions. The appropriate use of laser intensity requires calibration and corrections for influencing factors, which are different in caves as opposed to the above-ground environments. Our study presents an efficient and complex workflow to correct the recorded intensity, which takes into consideration the acquisition geometry, micromorphology of the cave surface, and the specific atmospheric influence previously neglected in terrestrial laser scanning. The applicability of the approach is demonstrated on terrestrial LiDAR data acquired in the Gouffre Georges, a cave located in the northern Pyrenees in France. The cave is unique for its geology and lithology allowing for observation, with a spectacular continuity without any vegetal cover, of the contact between marble and lherzolite rocks and tectonic structures that characterize such contact. The overall accuracy of rock surface classification based on the corrected laser intensity was over 84%. The presence of water or a wet surface introduced bias of the intensity values towards lower values complicating the material discrimination. Such conditions have to be considered in applications of the recorded laser intensity in mapping underground spaces. The presented method allows for putting geological observations in an absolute spatial reference frame, which is often very difficult in a cave environment. Thus, laser scanning of the cave geometry assigned with the corrected laser intensity is an invaluable tool to unravel the complexity of such a lithological environment.
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Margarida Romero
  • Laboratoire d'Innovation et Numérique pour l'Education
Szilvia Ecsedi
  • Institut de Biologie Valrose; Epi-transcriptomics Group
Nice, France