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Steady state radiation responses of graded-index germanosilicate multimode optical fibers
No full textInternational audienc
Process evaluation of a school-based vaccination intervention to improve HPV vaccine coverage: A mixed-method study embedded in the French PrevHPV cluster randomized controlled trial
No full textInternational audienceBackgroundHuman papillomavirus vaccine coverage (HPV VC) remains suboptimal in many countries. French authorities launched the PrevHPV research program, which included a cluster randomized controlled trial (cRCT) to evaluate the effectiveness of an ‘at-school vaccination’ intervention. Within this trial, we conducted a process evaluation of this intervention, specifically analyzing (i) its implementation, (ii) its mechanisms of impact, and (iii) the contextual factors influencing implementation (facilitators/barriers).MethodWe conducted a mixed-method study embedded in the PrevHPV cRCT (April 2021–April 2022). ‘At-school vaccination’ consisted of vaccination day(s) on school premises where mobile vaccination teams (MVTs) initiated HPV vaccination free of charge for eligible adolescents (i.e., non-vaccinated adolescents aged 11+). Quantitative data were collected through activity reports and self-administered questionnaires of adolescents and school staff. Qualitative data collected through six focus groups with school staff and MVTs were analyzed using thematic analysis.ResultsOf the 31 schools (14,772 adolescents) randomized to implement ‘at-school vaccination’, 12 (39 %) dropped out. Among the participating schools, analysis of implementation showed that 17 % of adolescents returned valid consent forms, of whom 89 % initiated vaccination. MVTs played a central role in implementing vaccination day(s), supported by several school staff (e.g., school nurses, education assistants). Regarding mechanisms of impacts, satisfaction with the vaccination days was high among adolescents and school staff. The intervention generated both positive and negative group effects among adolescents. Contextual factors that facilitated implementation included the preparation of a list of adolescents to be vaccinated and the availability and motivation of school staff. The main barriers related to the management of consent forms and missing health records.ConclusionWe formulated recommendations for implementing at-school vaccination, which may be particularly helpful for the French school HPV vaccination campaigns that were scaled up nationally in 2023. We also discussed potential macro-level improvement strategies, involving modifications to the legislative framework
Ultramafic float rocks at Jezero crater (Mars): excavation of lower crustal rocks or mantle peridotites by impact cratering?
No full textInternational audienceBased on observation and data from meteorites and in situ scientific missions, experiments as well as models, the Martian mantle is assumed to share some compositional and mineralogical affinity with the terrestrial mantle. However, there might be subtle differences like the Martian mantle being more ferroan. Yet, we do not have any direct analysis of a Martian mantle rock to confirm this assumption. NASA’s Perseverance rover found olivine-rich boulder-sized float rocks on the upper Jezero fan (Mars). These boulders have an ultramafic composition and their mineralogy is dominantly composed of Fo73±3 olivine with high-Mg orthopyroxene, Cr-rich Ti-Fe oxides and minor plagioclase and high-Ca pyroxene. Microtextural and petrological analysis reveals that these minerals crystallized at equilibrium. In addition, these boulders are different from all the bedrocks analyzed by Perseverance along its traverse which are crustal igneous rocks and sediments. Comparing our data to Martian meteorites and available Mars bulk silicate models (BSM), we discuss that these boulders could represent primitive melts and/or lower crustal material, and we specifically hypothesize that they could be mantle peridotites. We propose that these putative mantle rocks could have been excavated by the succession of impacts from the shallow mantle or lower crust in the Isidis region where Jezero crater is located. These olivine-rich boulders could thereby constitute the first direct analysis of a Martian mantle rock
A Cahn--Hilliard--Willmore phase field model for non-oriented interfaces
No full textInternational audienceWe investigate a new phase field model for representing non-oriented interfaces, approximating their area and simulating their area-minimizing flow. Our contribution is related to the approach proposed in arXiv:2105.09627 that involves ad hoc neural networks. We show here that, instead of neural networks, similar results can be obtained using a more standard variational approach that combines a Cahn-Hilliard-type functional involving an appropriate non-smooth potential and a Willmore-type stabilization energy. We show some properties of this phase field model in dimension and, for radially symmetric functions, in arbitrary dimension. We propose a simple numerical scheme to approximate its -gradient flow. We illustrate numerically that the new flow approximates fairly well the mean curvature flow of codimension or interfaces in dimensions and
Materiality in institutional work: shaping the emerging logic of policy co-creation
No full textInternational audienceFollowing the material turn in the study of institutions, this research focuses on the tangible elements actors use to influence institutions. Specifically, in the context of an institutional void surrounding the emergence of a new institutional logic, we seek to understand how actors utilise materiality in their institutional work to shape this new logic. We conducted a qualitative exploratory study based on a single case, analysing the emergence of the logic of co-creation. This logic, which advocates for the inclusion of citizens in decision-making processes, poses challenges to public organisations. We explore how this logic emerged in a French municipality through the implementation of co-creation workshops with citizens. Our research involved observations, interviews and the collection of secondary data to achieve an in-depth understanding of our case study and its complexities. Our findings reveal that three forms of materiality – artefacts and objects, space and time, bodies and embodiment – are particularly relevant in institutional work. These forms play multiple roles in institutional work, illustrating both the enabling and constraining aspects of materiality. This study underscores the strategic role of materiality in the process of institutional work
Congruences for hook lengths of partitions
No full text14 pages, all comments are welcome ! arXiv admin note: text overlap with arXiv:2107.06793International audienceRecently, Amdeberhan et al. proved congruences for the number of hooks of fixed even length among the set of self-conjugate partitions of an integer , therefore answering positively a conjecture raised by Ballantine et al.. In this paper, we show how these congruences can be immediately derived and generalized from an addition theorem for self-conjugate partitions proved by the second author. We also recall how the addition theorem proved before by Han and Ji can be used to derive similar congruences for the whole set of partitions, which are originally due to Bessenrodt, and Bacher and Manivel. Finally, we extend such congruences to the set of -asymmetric partitions defined by Ayyer and Kumari, by proving an addition-multiplication theorem for these partitions. Among other things, this contains as special cases the congruences for the number of hook lengths for the self-conjugate and the so-called doubled distinct partitions
Weak error estimates of fully-discrete schemes for the stochastic Cahn-Hilliard equation
No full textInternational audienceWe study a class of fully-discrete schemes for the numerical approximation of solutions of stochastic Cahn-Hilliard equations with cubic nonlinearity and driven by additive noise. The spatial (resp. temporal) discretization is performed with a spectral Galerkin method (resp. a tamed exponential Euler method). We consider two situations: space-time white noise in dimension d " 1 and trace-class noise in dimensions d " 1, 2, 3. In both situations, we prove weak error estimates, where the weak order of convergence is twice the strong order of convergence with respect to the spatial and temporal discretization parameters. To prove these results, we show appropriate regularity estimates for solutions of the Kolmogorov equation associated with the stochastic Cahn-Hilliard equation, which have not been established previously and may be of interest in other contexts
Motor complications and postural abnormalities interplay in Parkinson's disease
No full textInternational audienceBackground: Postural abnormalities (PA) and motor complications (MCs, including motor fluctuations - MFs- and levodopa-induced dyskinesia - LIDs) are hallmark of Parkinson's disease (PD) progression, yet their relationship remains poorly understood.Objective: To investigate the association between PA and MCs, motor symptoms, and non-motor symptoms (NMS) in patients with PD, and to assess whether PA influences the development of MCs over time.Methods: Data of the prospective NS-Park cohort (27 French PD Expert Centers) were analysed. PA was defined by a score ≥2 on item 3.13 of the MDS-UPDRS-III. Associations between PA and MCs, as well as with other motor symptoms and NMS, were assessed using logistic regression models. We used interval censoring survival models to assess the associations between PA at inclusion and the incidence of MCs. Analyses were adjusted for sex, age, disease duration, dopaminergic dose, and disease severity.Results: Among 13,037 included PD patients (58.7 % male, median age at diagnosis 61 years), 724 (5.6 %) presented with PA. Patients with PA had longer disease duration, higher disease severity, and higher dopaminergic treatment. PA exhibited a higher prevalence of troublesome MFs (OR: 5.96; 95 % CI: 4.25-8.32) and LIDs (OR: 2.81; 95 % CI: 1.79-4.30), while associations with milder MCs were inconsistent. However, PA was not significantly associated with the development of MCs during follow-up.Conclusions: PA are associated with more frequent severe MCs, and a higher burden of motor and NMS, making patient care particularly challenging
Cyclic exclusive enteral nutrition versus partial enteral nutrition to maintain long-term drug-free remission in paediatric Crohn's disease (CD-HOPE): an open-label, endpoint-blinded, randomised controlled trial
No full textInternational audienceBackgroundFor children with Crohn's disease, there is a marked demand for long-term nutritional treatment strategies to avoid the side-effects related to drug treatment. We aimed to investigate whether paediatric patients with Crohn's disease responding to nutritional induction therapy can be maintained in remission on dietary therapy without the use of medication or surgery.MethodsIn this open-label, endpoint-blinded, randomised controlled trial (CD-HOPE) done in 21 hospitals of the GETAID pédiatrique network in France, eligible patients were aged 6 years to younger than 18 years with Crohn's disease (newly diagnosed or relapsing after drug treatment) who had reached clinical remission (weighted Paediatric Crohn's Disease Activity Index [wPCDAI] ≤12·5) after induction therapy with 6–12 weeks of exclusive enteral nutrition (EEN; 100% of calories). Stratified by age (≤10 years or >10 years) and relapse status, patients were randomly assigned (1:1) using block randomisation to receive either cyclic EEN (C-EEN; 100% of daily caloric requirements) for 2 weeks every 8 weeks for at least six cycles or daily partial enteral nutrition (PEN; 25% of daily caloric requirements) for 52 weeks. Oral MODULEN IBD was used for both. Except for the 2-week intervals of EEN in the C-EEN group, food access was not restricted. The primary endpoint was relapse rate at 12 months. A relapse was defined as: (1) a wPCDAI score greater than 12·5 at two successive visits, or (2) a wPCDAI greater than 12·5 once and the need for Crohn's disease-related surgery, medication, or study exit, or (3) a wPCDAI score continuously greater than 12·5 since the last study visit, or (4) incomplete wPCDAI and moderate or severe Physician Global Assessment at any timepoint. Primary and safety analyses were performed on an intention-to-treat basis. This trial was registered on ClinicalTrials.gov (NCT02201693) and is complete.FindingsBetween Dec 12, 2014, and Sept 4, 2018 (last patient visit Oct 2, 2019), 112 patients were screened and 100 patients (70 boys and 30 girls) were randomly assigned to C-EEN (n=49) or PEN (n=51). Median age of participants was 12 years (IQR 11–13) in the C-EEN group and 13 years (11–14) in the PEN group. At 12 months, 24 (49%) of 49 patients had relapsed on C-EEN compared with 39 (76%) of 51 patients on PEN (adjusted odds ratio 0·29 [95% CI 0·13–0·70], p=0·0051). 19 adverse events occurred in 17 patients: four serious adverse events in four patients on PEN, not related to treatment, and 15 non-serious adverse events in 13 patients (nine in seven patients on C-EEN and six in six patients on PEN). The serious adverse events were all related to Crohn's disease relapse requiring hospitalisation for rescue therapy. Six adverse events were possibly related to study treatment: one patient in the C-EEN group reported transient vomiting and diarrhoea at the start of the first EEN cycle, one patient in the C-EEN group developed anorexia and, in the PEN group, four patients reported either weight loss, nausea, Crohn's disease relapse, or skin infection. No malignancy or death was reported in this study.InterpretationC-EEN was superior to PEN in maintaining clinical remission over 1 year in paediatric patients with Crohn's disease responding to EEN induction therapy. These findings suggest a new way to use nutritional therapy for maintaining drug-free long-term remission in patients with Crohn's disease who are responding to EEN induction therapy.FundingAssistance Publique-Hôpitaux de Paris and Nestlé Health Science