Portail HAL de l'Université Picardie Jules Verne
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Predictive Factors of Success After Weaning Attempt of Renal Replacement Therapy in Intensive Care Unit
No full textInternational audienc
Variation of canonical heights of subvarieties for polarized endomorphisms
No full textInternational audienceWhen an endomorphism f : X -> X of a projective variety which is polarized by an ample line bundle L, i.e. such that f*L similar or equal to L (R) d with d >= 2, is defined over a number field, Call and Silverman defined a canonical height hbf for f. In a family (X , f, L) parametrized by a curve S together with a section P : S -> X , they show that hft(P(t))/h(t) converges to the height hbf eta (P eta) on the generic fiber. In the present paper, we prove the equivalent statement when studying the variation of canonical heights of subvarieties Yt varying in a family Y of any relative dimension
Joining the locals: Plant invaders shift leaf defenses to match native neighbors
No full textInternational audienceLocal adaptation is common in invasive plants, but there is no consensus as to whether shifts in functional traits between invader “home” and “away” ranges contribute to their success in competition with native species. Theory based on enemy release suggests that invaders should reallocate limiting resources away from nutritive‐based defenses and toward high growth potential. However, empirical studies of home–away trait shifts are typically conducted on a single invader and fail to consider how environmental differences across regions may impact leaf trait syndromes. We measured nine defense‐related leaf traits for 27 invasive species across their home and away ranges in France, Japan, and the United States, and compared them to distributions of those same traits for co‐occurring native species in both their home and away ranges. Our study included a total of 21 woody species sampled under forest canopies, and 23 herbaceous species sampled in fields and roadsides. Traits included toxic leaf alkaloids and cyanogenic glycosides; structural attributes including cell wall mass and fiber content; carbon (C), nitrogen (N), C:N, and total protein content; and specific leaf area. We found significant overall shifts in both qualitative (alkaloids) and quantitative (fiber, cell wall, N content) defense traits, particularly in woody species that are hypothesized to be more apparent to herbivores. However, the direction of trait shifts was not consistent across regions. Rather, for seven of nine traits, trait means of invaders shifted toward the means of native species in the recipient communities, likely reflecting environmental differences among regions rather than a shift in allocation from defense to growth. We suggest this “join the locals” pattern, whereby trait shifts in invaders match regional differences in native trait syndromes due to environmental variation, is a reasonable null model for studies of adaptive evolution in invasive species. Although the “join the locals” pattern is not mutually exclusive with shifts in functional traits caused by enemy release, our study involving multiple species and habitats suggests environmental gradients override trait shifts driven by varying herbivore communities
Respiration Can Trigger Cerebrovascular Reactivity: A New Method to Quantify Respiratory-Driven CVR Using Real-time phase contrast MRI
No full textInternational audienceMotivation: Quantifying cerebrovascular reactivity (CVR) is key for diagnosing and understanding neurological diseases. However, measuring respiratory-driven CVR is challenging due to the difficulty in separating cardiac effects from CVR modulation.Goal(s): Propose a novel approach to accurately quantify respiratory-driven CVR.Approach: Using real-time phase-contrast sequences and respiratory signals to quantify respiratory-driven CVR by analysing the flow ratio (Ratio-Q) between the internal and external carotid arteries.Results: Sustained deep breathing increases cerebrovascular resistance causing a 20% reduction in average carotid artery flow and Ratio-Q. CVR also regulates cerebrovascular resistance at the respiratory frequency, stabilizing cerebral blood flow fluctuations.Impact: This study introduces a new, effective method for measuring respiratory-driven CVR, comparing results across two different breathing modes. It provides crucial methodological support and reference data for clinical and physiological research
Optimizing Urban Mining Investments: Leveraging Sequential Compound Real Option Analysis for Circular Economy Transition
No full textInternational audienceThe development of urban mining, specifically in metal recovery from e-waste, is essential for achieving the circular economy. However, difficulties in accessing suitable financing as well as insufficient investment in recycling infrastructures emerge as important barriers. Given the intricate recovery process involving multi-stage investments and diverse inputs, technologies, and uncertainty levels, traditional discounted cash flow methods fail to adequately capture the sequential dynamics of urban mining investments. This paper pioneers the application of real options theory in evaluating investment in metal recovery. The paper includes a case study, offering practical insights into the feasibility of investing in a material recovery facility. The financial analyses reveal substantial value creation from managerial flexibility, evident in the gap between real option and discounted cash flow-derived net present value. The value of circularity, assessed through a complex real option, underscores the importance of adopting innovative financial methods. Findings support the proposition to maximize resource recovery from e-waste, especially through focused printed circuit board processing
Parkinson's Disease, Speech and Neurosurgery
No full textInternational audienceBackground: Speech impairment is a recognized but unpredictable adverse effect of sub-thalamic nucleus deep brain stimulation (STN-DBS) for Parkinson's disease (PD).Objectives: To evaluate the prevalence of speech impairment 1 year after STN-DBS in PD patients and to determine the predictive factors for speech outcome following STN-DBS.Methods: Data for 417 patients from the French national PREDISTIM study were collected preoperatively. The combined effect of medical treatment and surgery on speech was compared using specific items from dedicated clinical scales (MDS-UPDRS III.1: primary endpoint) and patient self-assessment questionnaires (items 34 and 35 of the PDQ39: secondary endpoints). For each variable, three patient groups were generated according to speech outcome at 1 year: worsening, stability, and improvement. In the second step analysis, the three groups were compared for demographic and clinical variables at baseline and STN-DBS parameters.Results: There was a significant deterioration in speech of all considered items 1 year after combined STN-DBS and dopaminergic treatment. Four predictive factors for speech deterioration were detected: (i) the absence of preoperative speech impairment (p < 0.001); (ii) severity of motor activity of daily living (MDS-UPDRS II off total score) (p = 0.037); (iii) high-intensity stimulation of the left electrode (i.e., above 3.6 V) (p = 0.046); and (iv) the absence of any change in non-motor experiences of daily life (MDS-UPDRS I total score) (p = 0.048).Conclusions: Speech outcome should be carefully monitored after STN-DBS, especially in PD patients without preoperative speech impairment, with motor difficulties in daily-living activities, and with increased left electrode intensity.Trial registration: ClinicalTrials.gov identifier: NCT02360683
Characteristics of SARS-CoV-2-associated severe episodes of monoclonal gammopathy-associated capillary leak syndrome (Clarkson disease)
No full textInternational audienceBackground Monoclonal gammopathy-associated capillary leak syndrome (MG-CLS) is a rare condition characterized by recurrent episodes of hypovolemic shock caused by a sudden increase in capillary permeability. The COVID-19 pandemic has been associated with a rise in MG-CLS episodes and increased mortality. We aimed to explore the association between MG-CLS and SARS-CoV-2 infection. We conducted a multicenter retrospective observational study involving MG-CLS patients who were admitted to the intensive care unit (ICU). The primary endpoint was 28-day mortality according to whether SARS-CoV-2 was identified as a trigger. Results The study included 84 patients (44% women) with a median age of 55 years [IQR 46–62], accounting for 127 ICU admissions. Most patients (88%) had monoclonal gammopathy, predominantly with an IgG heavy chain (98%). A trigger was identified in 63% of cases, primarily suspected or confirmed viral infections, including 26 episodes of SARS-CoV-2 infection. Within 28 days of ICU admission, 32% of patients died. Episodes triggered by SARS-CoV-2 were associated with a higher need for mechanical ventilation (69% vs. 38%, p = 0.004), renal replacement therapy (54% vs. 31%, p = 0.03), and increased 28-day mortality (42% vs. 17%, p = 0.005). Multivariable analysis revealed that SARS-CoV-2 infection was independently associated with 28-day mortality (OR 4.67 [1.08–20.1], p = 0.04). The use of intravenous immunoglobulins did not improve 28-day survival. Conclusion In this large cohort of MG-CLS episodes requiring ICU admission, SARS-CoV-2as a trigger was associated with significantly higher 28-day mortality compared to other triggers. Further research is essential to elucidate the specific mechanisms by which SARS-CoV-2 impacts MG-CLS patients. Graphical abstrac
Phase-Engineered 1T/2H MoS2 via Spray Coating : Role of Precursor Concentration in Structural and Electronic Tuning
No full textInternational audienceMolybdenum disulfide (MoS₂) is particularly compelling due to its tunable electronic properties, which are intrinsically linked to its polymorphic phases. Controlling the synthesis of mixed-phase MoS2, comprising the metastable metallic 1T-MoS2 phase and the semiconducting 2H-MoS2, is essential for tailoring its structural and electronic properties. Here, we demonstrate the fabrication of 1T/2H-MoS2 mixed-phase structures via a spray coating method, emphasizing the impact of precursor concentration on phase composition and crystallinity. Comprehensive structural and spectroscopic analyses confirm the coexistence of both phases, revealing that increased precursor concentration promotes phase modulation. Optical properties investigations indicate a bandgap energy reduction from 1.48 to 1.19 eV as precursor concentration increases from 5 to 15 mmol·L⁻¹, underscoring the semiconducting nature of the mixed-phase. Electrical characterization further shows that the sample synthesized at 15 mmol·L⁻¹ exhibits the highest electrical conductivity of 2.23 × 10–² mS·cm–1 and the lowest resistivity of 44.78 kΩ·cm, attributed to an increased fraction of the 1T-MoS2 phase. These results provide a viable approach for engineering 1T/2H-MoS2 mixed-phase with tunable structural and electronic properties
