Université de Toulon
  • La Garde, France
Recent publications
Background: Musculoskeletal disorders are prevalent among physiotherapists. They perform many repetitive tasks in awkward postures that require a high muscle load. This issue was often addressed through subjective analysis (questionnaire) but rarely using postural evaluation combined with an ergonomic assessment. Objective: The aim of this article was to decompose draining lymphatic massage performed by physiotherapists in generic postures (GP) to quickly assess the musculoskeletal disorder risk. Methods: Based on numeric video recorded in frontal and sagittal planes, 3360 postures were defined from 20-minutes lymphatic drainage massage performed by 7 physiotherapists over a period of 6 months. A hierarchical cluster analysis was applied to define the GP. Results: Seven GP were identified, which were described by their average joint angles, variability and relative frequency. GP6, GP4 and GP2 had the highest frequencies (17.6%, 16.9% and 16.8% respectively). Trunk and neck were essentially flexed (neck: 17.0±10.0° for GP1; trunk: 20.4±8.7° for GP4). Shoulder flexion and abduction ranged from 15° (GP7) to 60° (GP4). Mean and variability of RULA score completed the analysis. The highest scores were computed for GP2 and GP3 (respectively 5.5±1.3 and 5.8±1.2, p < 0.05). GP4 had the lowest (4.0±1.1, p < 0.05). The results suggest that massages have to be monitored. Attention should be paid to the postures used to prevent the occurrence of MSDs. Conclusion: The massages could be described as a combination of generic posture for a rapid ergonomic assessment.
We consider the problem of finding a net that supports prescribed point forces, yet avoids certain obstacles, with all the elements of the net being under compression (or all being under tension), and being confined within a suitable bounding box. In the case of masonry structures, when described through the simple, no-tension constitutive model, this consists, for instance, in finding a strut net that supports the forces, is contained within the physical structure, and avoids regions that may be not accessible. We solve such a problem in the two-dimensional case, where the prescribed forces are applied at the vertices of a convex polygon, and we treat the cases of both single and multiple obstacles. By approximating the obstacles by polygonal regions, the task reduces to identifying the feasible domain in a linear programming problem. For a single obstacle we show how the region Γ available to the obstacle can be enlarged as much as possible in the sense that there is no other strut net, having a region Γ ′ available to the obstacle with Γ ⊂ Γ ′ . The case where some of the forces are reactive is also treated.
The ability to produce muscle power during sprint acceleration is a major determinant of physical performance. The comparison of the force–velocity (F–v: theoretical maximal force, F0; velocity, v0 and maximal power output, Pmax) profile between men and women has attracted little attention. Most studies of sex differences have failed to apply a scaling ratio when reporting data. The present study investigated the sex effect on the F–v profile using an allometric model applied with body mass (BM), fat-free mass (FFM), fat-free mass of the lower limb (FFMLL), cross-sectional area (CSA) and leg length (LL) to mechanical parameters. Thirty students (15 men, 15 women) participated. Raw velocity–time data for three maximal 35 m sprints were measured with a radar. Mechanical parameters of the F–v relationship were calculated from the modelling of the velocity–time curve. When F0 and Pmax were allometrically scaled with BM (p = 0.538; ES = 0.23) and FFM (p = 0.176; ES = 0.51), there were no significant differences between men and women. However, when the allometric model was applied to Pmax with FFMLL (p = 0.015; ES = 0.52), F0 with CSA (p = 0.016; ES = 0.93) and v0 with LL (p ≤ 0.001; ES = 1.98) differences between men and women persisted. FFM explained 83% of the sex differences in the F–v profile (p ≤ 0.001). After applying an allometric model, sex differences in the F–v profile are explained by other factors than body dimensions (i.e., physiological qualitative differences).
Wastewater-treatment plants (WWTPs) are considered significant point sources of microplastics (MiP) in the receiving waters; MiP release is poorly estimated in developing countries. MiP abundance, recovery efficiency and daily load to receiving waters were explored in treatment stage facilities of four WWTPs in Vietnam, located in Ho Chi Minh City, Thu Dau Mot, and Da Lat. MiP abundance varied from 1860 items m⁻³ to 125,000 items m−3 in influents and between 140 items m⁻³ and 813 items m⁻³ in the final effluents. The MiP-removal efficiency was the highest in the Da Lat wastewater-treatment plant (DL WWTP), a tertiary treatment plant using trickling filters followed by aerated lagoon and maturation ponds for BOD and nitrogen removals. The lowest MiP-removal efficiency was observed in Binh Hung wastewater-treatment plant (BH WWTP), a combined sewer system using conventional activated sludge processes as secondary treatment. The total daily MiP load to the receiving environment varied from 1,840,000 items d⁻¹ at the DL WWTP to 77,127,000 items d⁻¹ at the BH WWTP. Change in MiP abundance, morphology, and removal efficiency were discussed after each stage of the treatment process for the four WWTPs.
The analysis of intra-cycle velocity profile of manual wheelchair (MWC) users has been used to highlight the significant role of trunk inertia in propulsion biomechanics. Maximal wheelchair linear velocity has previously been observed to be reached after the release of the handrims both during sports activities and daily life propulsion. This paper provides a combined analysis of linear velocity and trunk kinematics in elite wheelchair racing athletes during straight-line propulsion at stabilized speeds. MWC and trunk kinematics of eight athletes (level: 7 elite, 1 intermediate; classification: T54 (5), T53 (2) and T52 (1)) were monitored during 400 m races using inertial measurement units. An average propulsion cycle was computed for each athlete. The main finding of this article is the difference in propulsion patterns among the athletes, exhibiting either 1, 2 or 3 peaks in their velocity profile. A second peak in velocity is usually assumed to be caused by the inertia of the trunk. However, the presence of a second velocity peak among more severely impaired athletes with little to no trunk motion can either be associated to the inertia of the athletes' arms or to their propulsion technique.
Background Phase III trials have demonstrated the efficacy of risankizumab in moderate‐to‐severe Crohn's disease (CD), but no real‐world data are currently available. We aimed to assess the short‐term effectiveness and safety of risankizumab in patients with CD. Methods From May 2021 to May 2022, all patients with refractory luminal CD treated with risankizumab in 22 French GETAID centres were retrospectively included. The primary endpoint was steroid‐free clinical remission at week 12 (Harvey‐Bradshaw [HB] score <5). Secondary endpoints included clinical response (≥3‐point decrease of HB score and/or (HB) score <5), biochemical remission (CRP ≤ 5 mg/L), need for CD‐related surgery and adverse events. Results Among the 100 patients included, all have been previously exposed to anti‐TNF agents, 94 to vedolizumab, 98 to ustekinumab (all exposed to at least three biologics) and 61 had a previous intestinal resection. All but three (97%) received a 600 mg risankizumab intravenous induction at weeks 0–4–8. At week 12, steroid‐free clinical remission was observed in 45.8% of patients, clinical remission in 58% and clinical response in 78.5%. In subgroup analysis restricted to patients with objective signs of inflammation at baseline (n = 79), steroid‐free clinical remission at week 12 was observed in 39.2% of patients. Biochemical remission was observed in 50% of patients. Six patients discontinued risankizumab before the week 12 visit due to lack of efficacy. CD‐related hospitalisation was needed in six patients, and three underwent intestinal resection. In multivariable analysis, only a history of ustekinumab loss of response (vs primary failure) (odds ratio (OR), 2.80; 95% CI: 1.07–7.82; p = 0.041) was significantly associated with clinical remission at week 12. Twenty adverse events (AE) occurred in 20 patients including 7 serious AE corresponding to 6 CD exacerbation and one severe hypertension. Conclusion In a cohort of highly refractory patients with luminal CD and multiple prior drug failures including ustekinumab, risankizumab induction provided a clinical response in about 3 out of 4 patients and steroid‐free clinical remission in about half of patients.
This study aimed to determine the short-term effect of two isocaloric diets differing in the ratio of protein–carbohydrate on melatonin levels, sleep, and subsequent dietary intake and physical activity in healthy young men. Twenty-four healthy men took part in a crossover design including two sessions of three days on isocaloric diets whether high-protein, low-carbohydrate (HPLC) or lowprotein, high-carbohydrate (LPHC) followed by 24-h free living assessments. Sleep was measured by ambulatory polysomnography pre-post-intervention. Melatonin levels were assessed on the third night of each session on eight-point salivary sampling. Physical activity was monitored by accelerometry. On day 4, participants reported their 24-h ad-libitum dietary intake. LPHC resulted in better sleep quality and increased secretion of melatonin compared to HPLC. A significant difference was noted in sleep efficiency (p < 0.05) between the two sessions. This was mainly explained by a difference in sleep onset latency (p < 0.01) which was decreased during LPHC (PRE: 15.8 ± 7.8 min, POST: 11.4 ± 4.5 min, p < 0.001). Differences were also noted in sleep staging including time spent on REM (p < 0.05) and N1 (p < 0.05). More importantly, REM latency (PRE: 97.2 ± 19.9 min, POST 112.0 ± 20.7 min, p < 0.001) and cortical arousals (PRE: 7.2 ± 3.9 event/h, POST 8.5 ± 3.3 event/h) increased in response to HPLC diet but not LPHC. On day 4, 24-h ad libitum energy intake was higher following HPLC compared to LPHC (+64 kcal, p < 0.05) and explained by increased snacking behavior (p < 0.01) especially from carbohydrates (p < 0.05). Increased carbohydrates intake was associated with increased cortical arousals.
With the intensification of maritime traffic, recently emerged infectious diseases have become major drivers in the decline and extinction of species. Since 2016, mass mortality events have decimated the endemic Mediterranean Sea bivalve Pinna nobilis, affecting ca. 100% of individuals. These events have largely been driven by Haplosporidium pinnae ’s infection, an invasive species which was likely introduced by shipping. While monitoring wild populations of P. nobilis , we observed individuals that survived such a mass mortality event during the summer of 2018 (France). We considered these individuals resistant, as they did not show any symptoms of the disease, while the rest of the population in the area was devastated. Furthermore, the parasite was not detected when we conducted a PCR amplification of a species-specific fragment of the small subunit ribosomal DNA. In parallel, the transcriptomic analysis showed evidence of some parasite RNA indicating that the resistant individuals had been exposed to the parasite without proliferating. To understand the underlying mechanisms of resistance in these individuals, we compared their gene expression with that of susceptible individuals. We performed de novo transcriptome assembly and annotated the expressed genes. A comparison of the transcriptomes in resistant and susceptible individuals highlighted a gene expression signature of the resistant phenotype. We found significant differential expressions of genes involved in immunity and cell architecture. This data provides the first insights into how individuals escape the pathogenicity associated with infection.
Truss structures composed of members that work exclusively in tension or in compression appear in several problems of science and engineering, e.g., in the study of the resisting mechanisms of masonry structures, as well as in the design of spider web-inspired web structures. This work generalizes previous results on the existence of cable webs that are able to support assigned sets of nodal forces under tension. We extend such a problem to the limit analysis of compression-only “strut nets” subjected to fixed and variable nodal loads. These systems provide discrete element models of masonry bodies, which lie inside the polygon/polyhedron with vertices at the points of application of the given forces (“underlying masonry structures”). It is assumed that fixed nodal forces are combined with variable forces growing proportionally to a scalar multiplier (load multiplier), and that the supporting strut net is subjected to kinematic constraints at given nodal positions.
The aim of this paper is to deliver an econometric panel data analysis on economic complexity by using annual data from 133 countries during the period from 1984 to 2018. This work admits that spatial heterogeneity and discontinuity may affect economic complexity and that there is a more accurate supranational level of analysis and economic policy. The paper shows that variables such as GDP per capita and economic vulnerability strongly affect the economic complexity of a country, while human capital and innovation rate are less significant. The potential of natural resources seems to be negatively correlated with economic complexity.
The fan mussel Pinna nobilis is currently on the brink of extinction due to a multifactorial disease mainly caused to the highly pathogenic parasite Haplosporidium pinnae, meaning that the selection pressure outweighs the adaptive potential of the species. Hopefully, rare specimens have been observed somehow resistant to the parasite, stretching the need to identify the traits underlying this better fitness. Among the candidate to explore at first intention are fast evolving immune genes, of which toll-like receptor (TLR). In this study, we examined the genetic diversity at 14 TLR loci across Pinna nobilis, Pinna rudis and Pinna nobilis x Pinna rudis hybrid genomes, collected at four physically distant regions, that were found to be either resistant or sensitive to the parasite Haplosporidium pinnae. We report a high genetic diversity, mainly observed at cell surface TLRs compared to that of endosomal TLRs. However, the TLR-7 and TLR-1 exhibited unexpected level of diversity and haplotype phylogeny, respectively. The lack of population structure, associated with a high genetic diversity and elevated dN/dS ratio were interpreted as balancing selection, though both directional and purifying selection were detected. Overall, we observed small contributions of putatively selected SNPs involved in the resistance. However, the most contributing SNPs were carried by two TLR-6 loci and might be used as potent biomarkers of distinguish between resistant and sensitive P. nobilis individuals. Moreover, more than 10% of P. nobilis individuals were found introgressed with P. rudis. Noteworthy, all introgressed P. nobilis observed as resistant to H. pinnae carried a TLR-7 of P. rudis origin. This study contributes to the ongoing efforts towards conservation carried out to prevent from extinction this Mediterranean endemic species.
The aim of this study was to examine the effect of delayed evening mealtime on sleep quality in young athletes. Twelve rugby players (age 15.8 ± 0.7 years) participated in a crossover within-participant design. Adolescents spent five consecutive days in each of two conditions, separated by a 2-week washout period: routine dinner (3.5 hr before bedtime) and late dinner (LD, 1.5 hr before bedtime). Other mealtimes as well as bedtime and wake-up time were usual and remained the same in both conditions. Their schedules, dietary intakes, and physical activity were controlled and kept constant throughout the study. Sleep was assessed using polysomnography on the first and the last nights in the individual rooms of the boarding school. An increase in total sleep time by 24 min (p = .001, d = 1.24) and sleep efficiency by 4.8% was obtained during LD (p = .001, d = 1.24). Improvement in sleep efficiency was mainly due to a lower wake after sleep onset (−25 min, p = .014, d = −3.20), a decrease of microarousals (−25%, p = .049, d = −0.64), and awakenings ≥90 s (−30%, p < .01, d = −0.97) in LD compared to routine dinner. There were no significant differences in sleep architecture except for a shorter slow-wave sleep (N3) latency (−6.9 min, p = .03, d = −0.778) obtained during LD. In this study, evening dinner 1.5 hr before bedtime leads to better quality and less fragmented sleep compared to evening dinner 3.5 hr before bedtime in young athletes.
In this paper, we study a class of reflected backward stochastic differential equations (RBSDEs) driven by the compensated random measure associated to a given pure jump Markov process X on a general state space U. The reflection keeps the solution above a given càdlàg process. We prove the uniqueness and existence both by a combination of the Snell envelope theory and a fixed-point argument. As a consequence of these results, the Markovian structure of X allows us to represent probabilistically the solution of some quasi-variational inequalities problem.
Duoskelion structures have been recently introduced by Barchiesi et al. (2021) as a proof-of-concept motif for a new class of metamaterials. The properties of these periodic beam-like chiral structural elements have been investigated, up to now, by means of a discrete model formulation whose predictions are obtained by numerical methods. In this paper we select a specific scaling law for micro stiffnesses aimed at deriving, via asymptotic homogenization, an internally-constrained Cosserat one-dimensional planar continuum model as the limit of a duoskelion structure. We analyze qualitatively and quantitatively the family of equilibrium configurations of the homogenized continuum when subjected to axial loading and compare the results of the analysis with those obtained by means of the discrete model formulation.
In this work, an original ion-imprinted polymer (IIP) was synthetized for the highly selective removal of Ni(II) ions in neutral and acidic media. First a novel functional monomer (AMP-MMA) was synthetized through the amidation of 2-(aminomethyl)pyridine (AMP) with methacryloylchloride. Following Ni(II)/AMP-MMA complex formation study, the Ni(II)-IIP was produced via inverse suspension polymerization (DMSO in mineral oil) and characterized with solid state ¹³C CPMAS NMR, FT-IR, SEM and nitrogen adsorption/desorption experiments. The Ni(II)-IIP was then used in solid-phase extraction of Ni(II) exploring a wide range of pH (from neutral to strongly acidic solution), several initial concentrations of Ni(II) (from 0.02 to 1 g/L), and the presence of competitive ions (Co(II), Cu(II), Cd(II), Mn(II), and Mg(II)). The maximum Ni(II) adsorption capacity at pH 2 and pH 7 reached values of 138.9 mg/g and 169.5 mg/g, that are among the best reported in literature. The selectivity coefficients toward Cd(II), Mn(II), Co(II), Mg(II) and Cu(II) are also very high, with values up to 38.6, 32.9, 25.2, 23.1 and 15.0, respectively. The Ni(II)-IIP showed good reusability of up to 5 cycles both with acidic and basic Ni(II) eluents.
Background and aims Binge drinking is a widespread practice among adolescents worldwide and is associated with various harmful consequences. Theory-based interventions are a promising approach to prevent this drinking behaviour in this population. The aim of the present review was to determine: (1) the characteristics of theory-based interventions targeting binge drinking in adolescents, (2) the impact of such interventions on binge drinking, and (3) the quality of theoretical implementation. Methods For this systematic review, randomised controlled trials were eligible for inclusion if the binge drinking-targeting intervention was based at least on one theoretical framework, and if the population's mean age was between 10 and 18 years. Two authors extracted relevant data. A meta-analysis was conducted to evaluate the effect of interventions on binge drinking. Effect sizes were calculated with the Hedges's g. Binge drinking was measured as a continuous or dichotomous outcome. The quality of theoretical implementation of interventions was measured using an existing “theory coding scheme”. Results Sixteen studies were identified. Ten were based on a single theory, and six on a combination of theories. The number and type of behaviour change techniques used in each intervention varied greatly. Theory-based interventions led to a small but significant decrease in binge drinking (Hedges's g = 0.10; 95% confidence interval = 0.04, 0.16). The quality of theoretical implementation was globally low, and the reciprocal link between behaviour change techniques and theoretical constructs was unclear for most studies. Conclusions Theory-based interventions have a small but significant beneficial impact on decreasing binge drinking in adolescents. Future research should try to be more effective in matching theoretical determinants of behaviour with the content of the intervention.
Metal organic frameworks (MOFs) are attracting remarkable attention in adsorption, chemical sensors, gas separation, photocatalysis, electrocatalysis and catalysis. In particular, zeolitic imidazolate framework 8 (Noted ZIF-8) which is composed of zinc ions and imidazolate ligands, have found its application in different areas of catalysis due to its outstanding structural and textural properties. It exhibits a highly porous structure as well as chemical and thermal stability in reaction conditions. When used alone in reaction medium the ZIF-8 particles tend to agglomerate which inhibit their removal efficiency or selectivity. This causes a mediocre reusability and separation from aqueous conditions. Thus, to overcome these drawbacks, several well-designed ZIF-8 structures by forming composites, doping and heterostructures were emerged. This review focuses on the recent advances on the use of ZIF-8 structures (doping, composites, heterostructures etc..) in the removal and photodegradation of persistent organic pollutants. We have focused in the adsorption and photocatalysis of three main organic pollutants (Methylene Blue, Rhodamine B, Malachite Green). Finally, key challenges, prospects and future directions were outlined to give insights to game-changing breakthroughs in this area.
Background In children a sedentary lifestyle is associated with the development of chronic diseases, as well as unfavorable body composition and physical condition, lower levels of self-esteem, sociability, and school results. In Europe 39,8% of children (6-9 years) spend on average more than 2h/day in front of a screen, and 14,6% over 3h/day. In this context, designing and testing effective interventions to decrease sedentary behavior in children is a major public health research gap. The CIPRES intervention aims to reduce sedentary time in school-age children (7-10 years). Methods The CIPRES intervention is co-constructed with key local actors, by using a socio-ecological approach, and theory-based on the transcontextual model. The intervention is evaluated by a cluster-randomized controlled study currently ongoing. The target population is made up of 1000 children from 13 primary schools (in years 4-5) from southeast of France with different levels of social deprivation. Main outcomes are assessed by accelerometer and questionnaires before (T0) and after a six-week intervention (T1) and include sedentary behavior, physical activity (PA) and variables of the transcontextual model. Results Preliminary data were available in 152 children (53 intervention and 99 control). There was no significant difference across the time in sedentary time between intervention and control group (p = 0.11; η2=0,017); however, moderate-to-vigorous physical activity (MVPA) tended to be better in intervention vs control (p = 0.06; η2=0,023). In the intervention group, sedentary time and MVPA were significantly better across the time (p = 0.028 and p = 0.011, respectively) for children having a father with a university diploma as compared to children having a father with a lower education level. Conclusions Preliminary results on a small group of subjects (n = 152) are encouraging and suggest a positive impact of the intervention on children. More results will be available by summer 2022. Key messages • Based on the socio-ecological model, the CIPRES intervention aims to prevent sedentary in school-aged children. • Preliminary data suggests a favorable impact of the intervention on physical activity.
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1,026 members
Philippe Dumas
  • Laboratoire I3M, Information, Milieu, Médias, Médiations
jean michel Maixent
  • UFR de Sciences et Techniques des Activités Physiques et Sportives (STAPS)
Christine Bressy
  • MAPIEM - Matériaux Polymères Interfaces Environnement Marin - EA 4323
Yann Bertacchini
  • Institute of ingineering sciences of Toulon
Benjamin Misson
  • MIO - Institut Méditerranéen d'Océanologie - UMR 7294
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La Garde, France
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