HAL-UNICE
Not a member yet
30584 research outputs found
Sort by
Les ressources en eau et le changement climatique en Provence-Alpes-Côte d’Azur,
No full text39 co-auteursComment citer cette publication du GREC-PACA ?Les ressources en eau et le changement climatiqueen Provence-Alpes-Côte d’Azur, Les cahiers du GRECPACA,édités par l’Association pour l’innovation etla recherche au service du climat (AIR), juillet 2017,52 pages. ISBN : 9782956006053il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : REPORTLes ressources en eau et le changement climatique en Provence-Alpes-Côte d’Azur
Exposure to Umbelliferone Reduces Ralstonia solanacearum Biofilm Formation, Transcription of Type III Secretion System Regulators and Effectors and Virulence on Tobacco
No full textRalstonia solanacearum is one of the most devastating phytopathogens and causes bacterial wilt, which leads to severe economic loss due to its worldwide distribution and broad host range. Certain plant-derived compounds (PDCs) can impair bacterial virulence by suppressing pathogenic factors of R. solanacearum. However, the inhibitory mechanisms of PDCs in bacterial virulence remain largely unknown. In this study, we screened a library of coumarins and derivatives, natural PDCs with fused benzene and alpha-pyrone rings, for their effects on expression of the type III secretion system (T3SS) of R. solanacearum. Here, we show that umbelliferone (UM), a 7-hydroxycoumarin, suppressed T3SS regulator gene expression through HrpG-HrpB and PrhG-HrpB pathways. UM decreased gene expression of six type III effectors (RipX, RipD, RipP1, RipR, RipTAL, and RipW) of 10 representative effector genes but did not alter T2SS expression. In addition, biofilm formation of R. solanacearum was significantly reduced by UM, though swimming activity was not affected. We then observed that UM suppressed the wilting disease process by reducing colonization and proliferation in tobacco roots and stems. In summary, the findings reveal that UM may serve as a plant-derived inhibitor to manipulate R. solanacearum T3SS and biofilm formation, providing proof of concept that these key virulence factors are potential targets for the integrated control of bacterial wilt
Structural basis for plant plasma membrane protein dynamics and organization into functional nanodomains
No full textPlasma Membrane is the primary structure for adjusting to ever changing conditions. PM sub-compartmentalization in domains is thought to orchestrate signaling. Yet, mechanisms governing membrane organization are mostly uncharacterized. The plant-specific REMORINs are proteins regulating hormonal crosstalk and host invasion. REMs are the best-characterized nanodomain markers via an uncharacterized moiety called REMORIN C-terminal Anchor. By coupling biophysical methods, super-resolution microscopy and physiology, we decipher an original mechanism regulating the dynamic and organization of nanodomains. We showed that targeting of REMORIN is independent of the COP-II-dependent secretory pathway and mediated by PI4P and sterol. REM-CA is an unconventional lipid-binding motif that confers nanodomain organization. Analyses of REM-CA mutants by single particle tracking demonstrate that mobility and supramolecular organization are critical for immunity. This study provides a unique mechanistic insight into how the tight control of spatial segregation is critical in the definition of PM domain necessary to support biological function
Lethal and sublethal effects of cyantraniliprole, a new anthranilic diamide insecticide, on Bemisia tabaci (Hemiptera: Aleyrodidae) MED
No full textThis study was supported partly by research grants from National Science and Technology Support task (2012BAD19B06), the earmarked fund for Beijing Leafy Vegetables Innovation Team of Modern Agro-industry Technology Research System (blvt-13), the earmarked fund for Modern Agro-industry Technology Research System (2013003019) and the earmarked fund from Beijing Academy of Agriculture and Forestry Sciences (QNJJ201610).The Bemisia tabaci (Gennadius) cryptic species complex comprises important insect pests that cause devastating damage to agricultural crops worldwide. In China, the B. tabaci MED species, formerly known as biotype ‘Q’, has surpassed the MEAM1 species, formerly known as biotype ‘B’, which is threatening agricultural production all over the country as an increasing number of resistance cases have been reported. This situation highlights the need for alternative pest control measures. In this study, the lethal effects of six neonicotinoid and two anthranilic diamide insecticides including the novel compound cyantraniliprole on B. tabaci MED were examined. The sublethal effects of cyantraniliprole on the physiology and behavior of B. tabaci MED were also assessed. Among eight insecticides tested, cyantraniliprole was the most toxic to B. tabaci MED with a LC50 of 2.05 mg/L. The sublethal effects of cyantraniliprole to adult B. tabaci MED were observed at LC10 (0.22 mg/L) and LC25 (0.63 mg/L) concentrations. At these concentrations, cyantraniliprole prolonged the developmental duration and decreased the survival rate of nymph stages, pseudopupae and adults. The oviposition duration and fecundity of females were also reduced significantly. The hatching rate of eggs laid by females exposed to LC10 and LC25 concentrations was also reduced. Altogether, these results demonstrate that cyantraniliprole could be an alternative insecticide for efficient control of B. tabaci MED populations in China
Well defined rare-earth doped silica nanoparticles for a new opportunity in photoluminescent uses : Synthesis and characterization
No full textInternational audienc
Sharp acceleration of a macroscopic contact line induced by a particle
No full textInternational audienc
Environmental control of natural gap size distribution in tropical forests
No full textInternational audienceNatural disturbances are the dominant form of forest regeneration and dynamics in unmanaged tropical forests. Monitoring the size distribution of treefall gaps is important to better understand and predict the carbon budget in response to land use and other global changes. In this study, we model the size frequency distribution of natural canopy gaps with a discrete power law distribution. We use a Bayesian framework to introduce and test, using Monte Carlo Markov chain and Kuo–Mallick algorithms, the effect of local physical environment on gap size distribution. We apply our methodological framework to an original light detecting and ranging dataset in which natural forest gaps were delineated over 30 000 ha of unmanaged forest. We highlight strong links between gap size distribution and environment, primarily hydrological conditions and topography, with large gaps being more frequent on floodplains and in wind-exposed areas. In the future, we plan to apply our methodological framework on a larger scale using satellite data. Additionally , although gap size distribution variation is clearly under environmental control, variation in gap size distribution in time should be tested against climate variability
Generalization of the concepts of seniority number and ionicity
No full textWe present generalized versions of the concepts of seniority number and ionicity. These generalized numbers count respectively the partially occupied and fully occupied shells for any partition of the orbital space into shells. The Hermitian operators whose eigenspaces correspond to wave functions of definite generalized seniority or ionicity values are introduced. The generalized seniority numbers (GSNs) afford to establish refined hierarchies of configuration interaction (CI) spaces within those of fixed ordinary seniority. Such a hierarchy is illustrated on the buckminsterfullerene molecule
Time-varying assessment of heart rate variability parameters using respiratory information
No full textInternational audienceAnalysis of heart rate variability (HRV) is commonly used for characterization of autonomic nervous system. As high frequency (HF, known as the respiratory-related) component of HR, overlaps with the typical low frequency (LF) band when the respiratory rate is low, a reference signal for HF variations would help in better discriminating the LF and HF components of HR. The present study proposes a model for time-varying separation of HRV components as well as estimation of HRV parameters using respiration information. An autoregressive moving average with exogenous input (ARMAX) model of HRV is considered with a parametrically modeled respiration signal as the input. The model parameters are estimated using smoothed extended Kalman filtering. Results for different synthetic data show that our proposed joint model outperforms the classical AR modeling in estimation of HRV parameters especially in the case of low respiration rate. In addition, the possibility of using pulse transit time (PTT) and the amplitude of photoplethysmogram (PPGamp) as surrogates of the input respiratory signal has been investigated. To this end, electrocardiogram (ECG), PPG and respiration have been recorded from 21 healthy subjects (10 males and 11 females, mean age 27.5 ± 4.1) during normal and deep respiration. Results show that indeed PTT and PPGamp offer good potential to be used as references for respiratory-related variations of HR, thus avoiding additional devices for recording respiration
Monitoring as-a-service to drive more efficient future system design
No full textInternational audienceIn the services world, the expected benefits are the fastest time to market, lower costs, greater consistency in the application, and increased agility. The reuse and sharing properties of software components are useful to address these challenges. However, to achieve this, it is necessary to be able to observe each service and to control the service composition. This article proposes to rethink the company's organisational process of application development and use the power of monitoring to help the application design. The proposed Monitoring as-a-service (MaaS), whose properties are detailed, will be used for the computation of the offered Quality of Service (QoS), for the services calibration during the service creation phase and to inform the QoS Controller during the operational phase. For effective design, the architect will place MaaS at crucial points of its architecture according to its decision-making process. Finally, we present experimental results and a conclusion ends the paper