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High-Throughput Analysis of the Flagella FliK-Dependent Surfaceome and Secretome in Bacillus thuringiensis
No full textInternational audienceBacillus thuringiensis is a entomopathogenic member of the Bacillus cereus group, known for its resistance to host antimicrobial peptides (AMPs) andhigh virulence in insect models. While flagella are traditionally associated with motility, they also contribute to virulence through secretion systems.This study identifies FliK, a protein involved in flagellar hook length control, as a critical determinant of AMP resistance and virulence, independent ofmotility. A ∆fliK mutant exhibited heightened AMP sensitivity and reduced pathogenicity in Drosophila, unlike other flagella-deficient strains. UsingLC-MS/MS, we conducted a comparative secretome and surfaceome analysis of the wild-type WT and ∆fliK strains. The ∆fliK mutant showed reducedsecretion of virulence factors and an increase in cell wall remodeling proteins, pointing to a broader role for FliK in protein regulation and cell surfacecomposition.These findings highlight FliK as a key regulator in B. thuringiensis pathogenesis and AMP resistance, offering new targets for investigating bacterialimmune evasion mechanisms
Human contributions to global soundscapes are less predictable than the acoustic rhythms of wildlife
No full textInternational audienceAcross the world, human (anthropophonic) sounds add to sounds of biological (biophonic) and geophysical (geophonic) origin, with human contributions including both speech and technophony (sounds of technological devices). To characterize society’s contribution to the global soundscapes, we used passive acoustic recorders at 139 sites across 6 continents, sampling both urban green spaces and nearby pristine sites continuously for 3 years in a paired design. Recordings were characterized by bird species richness and by 14 complementary acoustic indices. By relating each index to seasonal, diurnal, climatic and anthropogenic factors, we show here that latitude, time of day and day of year each predict a substantial proportion of variation in key metrics of biophony—whereas anthropophony (speech and traffic) show less predictable patterns. Compared to pristine sites, the soundscape of urban green spaces is more dominated by technophony and less diverse in terms of acoustic energy across frequencies and time steps, with less instances of quiet. We conclude that the global soundscape is formed from a highly predictable rhythm in biophony, with added noise from geophony and anthropophony. At urban sites, animals experience an increasingly noisy background of sound, which poses challenges to efficient communication
Genetic and transcriptomic analysis of a Saccharina latissima segregating F2 family detects groups of individuals with different responses to temperature stress
No full textInternational audienceSaccharina latissima is an important species for the emerging seaweed aquaculture industry in the northern Atlantic. In this study, genotype and phenotype data for a segregating F2 family was used to generate a highdensity genetic map for S. latissima and to identify temperature-stress-related quantitative trait loci (QTLs). A temperature stress experiment detected distinct phenotypic classes with different stress responses within the F2 family and these phenotypic classes were shown to exhibit different transcriptomic responses to heat stress. The existence of heat tolerant, resilient and sensitive individuals within this segregating family indicates that it should be possible to breed temperature tolerant strains of S. latissima. This conclusion was supported by the identification of three QTLs that influenced recovery after temperature stress. The results of this study and the resources generated, in particular the high-density genetic map, represent an important foundation for future S. latissima breeding programs.</div
Systematic Review and Meta-Analysis of Remineralizing Agents: Outcomes on White Spot Lesions
No full textInternational audienceDental caries is a widespread issue impacting global oral health. White spot lesions, the earliest stage of caries, compromise enamel's esthetics and integrity. Remineralization therapies, both fluoride and non-fluoride based, aim to restore enamel, but limited comparative data exist on their effects on lesion depth and microhardness. Thus, the aim of this systematic review was to evaluate the efficacy of remineralizing agents on lesion depth and microhardness of human teeth. The literature search included the following five databases: PubMed, Web of Science, Scielo, SCOPUS, and EMBASE from the period 2012 to October 2022. Studies evaluating lesion depth and microhardness in human teeth after the application of a remineralizing agent were considered for review. The meta-analysis was performed using RevMan 5.4 (The Cochrane Collaboration, Copenhagen, Denmark). A random effect model was used to pool estimate of effect and its 95% confidence intervals (CIs) for surface microhardness and depth lesion. Subgroup analyses were performed considering the presence of fluoride or not in the remineralization agent. Thirty-three studies were included in the qualitative review. Of these, twenty-six studies were included in the meta-analysis. The main risks of bias associated with the studies included a lack of blinding of the test operator and failure to obtain sample size. To conclude, fluorinated agents are more effective in remineralizing artificially induced white spot lesion than non-fluoride remineralizing agents.</div
Multi-material topology optimization of structural load-bearing capacity using limit analysis
No full textInternational audienceWe extend the problem of finding an optimal structure with maximum load-bearing capacity to the case of multiple materials. We first consider a reinforcement optimization case where the structure consists of a fixed background matrix material with given strength properties and optimize the reinforcement topology within this material. We discuss the use of various isotropic and anisotropic strength criteria to model the reinforcing phase, including reinforcements with discrete orientations. In a second time, we investigate a bi-material formulation where we optimize the topology of two material phases simultaneously. Various choices for the material strength conditions are proposed and we apply this formulation to the optimization of pure tensile and compressive phases of a single material. In all cases, two optimization variants are proposed using concepts of convex optimization and limit analysis theory, namely maximizing the load-bearing capacity under a fixed volume constraint or minimizing the volume under a fixed loading. Both problems are convex and a penalization procedure is proposed. The underlying problems can be solved using conic programming solvers. Illustrative applications demonstrate the versatility of the proposed formulation, including the influence of the selected strength criteria, the possibility to obtain structures with members of fixed orientation or structures with different importance granted to tensile and compressive regions. Finally, we also draw a parallel with the generation of strut-and-tie models for the analysis of reinforced concrete structures
Delay-Doppler Analysis of IR-UWB Signals for People Detection in Indoor Environments
No full textInternational audienceThe delay-Doppler analysis for moving people detection in smart factory-like indoor environments using impulse radio ultra-wideband (IR-UWB) radar is addressed in this paper. The transmitted signal's huge bandwidth results in a very fine range resolution, so that, unlike for a standard narrowband radar, mobile reflectors of interest to be detected (RID) migrate over several range resolution cells during the coherent integration period in slow time. The association of their motion characteristics and IR-UWB signal's features leads to troublesome effects after Doppler focusing (DF), such as spurious peaks and shortened ambiguity window. The results revealed by our delay-Doppler (or range-Doppler) analysis of the backscattered IR-UWB signals are reported in the paper and theoretical bounds for the Doppler ambiguity window in this specific case are derived. Moreover, we suggest a way to handle these aspects in the context of the considered application.</div
Heavy Metal Contamination in Yogurt from Lebanon: Evaluating Lead (Pb) and Cadmium (Cd) Concentrations Across Multiple Regions
No full textInternational audienceThe toxicity of metals such as lead (Pb) and cadmium (Cd) makes heavy metal contamination in food products a major health concern. The aim of this study is to measure the levels of Pb and Cd in yogurt samples that were collected from 11 distinct Lebanese locations and determine their compliance with the legal limits set by the European Commission (0.02 mg/kg for Pb and 0.005 mg/kg for Cd). A total of 165 yogurt samples were examined using atomic absorption spectrophotometry (AAS). Interestingly, the findings showed that 10.9% of samples had Pb concentrations over the allowable limit; the highest amounts were observed in Baalbeck-Hermel (0.118 mg/kg), North Area (0.125 mg/kg), and South Lebanon (0.115 mg/kg). In addition, the highest detected concentrations of Cd were found in North Area (0.094 mg/kg), Baalbeck-Hermel (0.076 mg/kg), and Akkar (0.042 mg/kg), with 14.5% of samples above the limit. The results show regional differences in contamination, which are probably caused by industrial emissions, agricultural activities, and environmental pollution. To better understand the potential health implications, the estimated daily intake (EDI) of Pb and Cd through yogurt consumption was calculated and compared to international healthbased guidance values. Although the EDI values suggest a low risk from yogurt alone, the findings highlight the importance of cumulative exposure and emphasize the necessity of regular monitoring and stricter implementation of food safety laws to decrease exposure to heavy metals through dairy intake.</div
Bonding to Demineralized Dentin: Impact of Immediate and Delayed Dentin Sealing over Time
No full textInternational audienceBackground/Objectives: Immediate dentin sealing (IDS) has been widely investigated in sound dentin; however, its efficacy on demineralized dentin remains insufficiently explored. This in vitro experimental study aimed to evaluate the shear bond strength (SBS) of indirect composite resin restorations bonded to demineralized dentin using IDS, assessed at 24 h and after 6 months of aging. Methods: Twenty-five extracted premolars were randomly divided into five groups: (1) control (no sealing), (2) IDS applied to sound dentin (sound-IDS), (3) IDS applied to demineralized dentin (carious-IDS), (4) delayed dentin sealing (DDS) on sound dentin (sound-DDS), and (5) DDS on demineralized dentin (carious-DDS). SBS values were analyzed using a three-way analysis of variance (ANOVA) with dentin condition (sound vs. demineralized), aging time (24 h vs. 6 months), and sealing strategy (control, IDS, DDS) as independent variables. Statistical analyses were performed using SigmaPlot 12.0, with significance set at p < 0.05. Results: The results showed that IDS led to significantly higher SBS than DDS (p < 0.05). Bond strength was significantly influenced by dentin condition (p < 0.05), and all interactions between variables-particularly between dentin condition and sealing strategy, and between aging time and treatment-were statistically significant (p < 0.001). Overall, bond strength was higher at 24 h than after 6 months. IDS showed optimal performance in sound dentin, while DDS resulted in better long-term outcomes in demineralized dentin. Conclusions: These findings suggest that DDS may be the more effective approach in cases of carious or demineralized dentin
Discordance between Patient and Physician Global Assessments of Psoriatic Arthritis Activity: An Observational Study in 13 Arab Countries Running head: Patient-Physician Discordance in PsA Activity in Arab Countries
No full textInternational audienceObjective: Discordance between physicians and patients in assessing psoriatic arthritis (PsA) activity is common and might impact treatment adherence and decision-making. Cultural and belief systems may influence this discordance. This study aimed to assess the extent of patient-physician discordance in PsA in Arab countries and its association with demographic and disease characteristics. Methods: The TACTIC study was a cross-sectional observational study across 13 Arab countries in 2022. Patient and physician global assessments (PGA,PhGA) of disease activity (0-10 scale) were collected, along with demographic and disease data, Disease Activity in Psoriatic Arthritis (DAPSA), and Psoriatic Arthritis Impact of Disease (PsAID). Discordance was defined as an absolute difference of |PGA-PhGA|>2. Its association with patient characteristics was analyzed through multivariable multinomial logistic regression. Results: In 538 patients (317 females,58.9%), with a mean age of 45.5±13.2 years and PsA duration of 8.8±7.3 years, the disease was moderately active (mean DAPSA 19.3±16.1; mean PsAID 3.86±2.33). Mean PGA was higher than mean PhGA (4.7±2.5 versus 4.0±2.4, p<0.001) with a high correlation between global assessments (r=0.74). Discordance was infrequent (84 patients,15.6%) and mostly due to higher PGA (70/84, 83.3%). Discordance (one-point increase) was associated with lower PhGA (Odds ratio (OR) 3.03 [95%CI 2.18-4.22]), positive fibromyalgia screening (OR 1.28 [95%CI 1.03-1.58]), higher DAPSA (OR 1.16 [95%CI 1.03-1.09]), and higher PsAID scores (OR 2.63 [95%CI 1.96-3.54]), and was primarily identified in patients with moderate disease activity. Conclusion: Discordance between PGA and PhGA was infrequent in Arab countries, suggesting strong patient-physician alignment. Expectations may play a role in this discordance
Blue Light's Impact on Skin Barrier Components: Insights from NP-LC/HR-MS n and Raman Analyses
No full textInternational audienceSkin health relies heavily on a well-maintained cutaneous barrier. While the detrimental effects of UV radiation on the epidermis are established, the impact of blue light, a significant component of sunlight and artificial sources, is less clear. This study aims to explore blue light’s influence on the reconstructed human epidermis (RHE) using two complementary analytical approaches: Raman microspectroscopy and normal phase liquid chromatography coupled with high-resolution mass spectrometry (NPLC/HR-MSn). RHE samples were exposed to blue light (415 nm and 455 nm) during different stages of their maturation.Raman spectra were acquired for both irradiated and non-irradiated (control) samples. Raman descriptors were analyzed to assess potential alterations in the structural organization of proteins and lipids’ conformational changes. Additionally, lipids from RHE samples were extracted and analyzed using NPLC/ HR-MSn. Blue light exposure led to changes in the structural organization of RHE lipids and proteins, as well as changes in the lipid composition. These changes varied depending on the wavelength and exposure dose. Exposure to blue light could disrupt the integrity of the skin’s protective barrier, leading to increased sensitivity to environmental stressors and potential skin damage