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Caprine dairy exploitation on the Iranian Plateau from the seventh millennium BC
No full textInternational audienc
Dissolved organic matter dynamics and chemistry under fungal activity: A microcosm incubation with litter differentially 13C-labelled
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Recent Insights Into Alzheimer's Disease: Advances in Pathophysiology and Therapeutic Strategies
No full textInternational audienceABSTRACT Alzheimer's disease (AD) is a complex neurodegenerative disorder driven by interplay among amyloid‐β (Aβ) plaques, tau neurofibrillary tangles, inflammation and comorbid pathologies. Recent advances in biomarkers and therapeutic approvals have reshaped our understanding of its pathophysiology and treatment landscape. This paper synthesizes evidence on the temporal dynamics of Aβ and tau deposition, highlighting tau's role as a key mediator of cognitive decline and the threshold‐dependent effects of Aβ. It explores how comorbidities—including vascular injury, neuroinflammation, and proteinopathies overlaps—modulate disease progression and response to therapy. Despite uncertainty about early anti‐Aβ approaches, recent monoclonal antibody trials (e.g., lecanemab, donanemab) demonstrate clinical benefit, underscoring the importance of early intervention. These agents require risk mitigation to avoid or manage amyloid‐related imaging abnormalities (ARIA). Emerging strategies emphasize precision medicine, targeting tau pathology and comorbid mechanisms to address the heterogeneous nature of AD. Integrating multi‐modal biomarkers and adaptive trial designs will be critical to developing effective, personalized therapies
Probing methane in Uranus’ upper stratosphere using HST observations of the 1280 Å Raman feature
No full textInternational audienceWe analysed far-ultraviolet (FUV) spectra of Uranus obtained by the HST STIS and COS instruments in 2012 and 2014, respectively, to determine the brightness of Raman-scattered Lyman-alpha (Ly α ) emissions centred at 1280 Å (hereafter, the Raman feature). The Raman feature is unique among the Solar System’s giant planets and forms in Uranus’ atmosphere due to weak vertical mixing of hydrocarbons with H 2 , leading to efficient Rayleigh–Raman scattering. Methane is the dominant hydrocarbon species on Uranus, and since it absorbs FUV radiation, it affects the Rayleigh–Raman scattering of Ly α photons by H 2 and, eventually, the brightness of the Raman feature. We derive a brightness of 20 −6 +1 R from the STIS data, which is similar to the brightness measured by Voyager 2 UVS during the 1986 flyby of Uranus, when considering the suggested recalibration of UVS measurements by a factor of ∼0.5. Based on the observed brightness, we constrain the upper altitude (pressure) level for the abundance of methane in the upper atmosphere using radiative transfer simulations that include resonant scattering by H, Rayleigh–Raman scattering by H 2 , and absorption by CH 4 . We considered the solar Ly α flux as the source of Ly α radiation at Uranus. We find that resonant scattering by H significantly affects Rayleigh–Raman scattering by H 2 and thus the modelled brightness of the Raman feature. We derive methane profiles by obtaining the simultaneous fit to the observed Ly α , as well as the 1280 Å brightness of Uranus. Methane appears to be depleted (number density becomes less than 1 cm −3 ) above the altitude (pressure) range of ∼478–515 km (4 × 10 −3 –2.4 × 10 −3 mbar), while the Ly α absorption optical depth reaches unity for methane in the altitude (pressure) range of ∼237–257 km (2.54 × 10 −1 –1.65 × 10 −1 mbar). When neglecting resonant scattering by H, the methane depletion must be deeper in the atmosphere at an altitude (pressure) of ∼395 km (1.4 × 10 −2 mbar), similar to previous findings based on Voyager 2 observations of the feature. The analysis of the Raman feature provides independent CH 4 constraints in the upper atmosphere for detailed photochemistry modelling and highlights the importance of UV instruments for the future Uranus Orbiter and Probe (UOP) mission
Tackling the interplay between the brain and kidneys: CYP2C19 mice as a preclinical tool for studying cognitive impairment in kidney disease?
No full textInternational audienc
Identification of rare missense variants reducing cathepsin O secretion in families with intracranial aneurysm
No full textInternational audienceAimsIntracranial aneurysm (IA) is a common cerebrovascular abnormality characterized by localized dilation and wall thinning in cerebral arteries, which can rupture and lead to fatal subarachnoid haemorrhage. Although genetic factors can contribute to IA, the genetic pre-disposition of IA is largely unknown. This study aims to identify rare functional variants associated with IA in families with multiple affected subjects and explore their impact on IA pathophysiology.Methods and resultsBy combining whole-exome sequencing and identity-by-descent analyses, we have identified two rare missense variants in the CTSO gene associated to IA in two large families with multiple affected subjects. We found that the cysteine-type papain-like cathepsin O (CTSO) encoded by CTSO is expressed in the circle of Willis of mice and in the wall of human IA domes. Stretching of vascular smooth muscle cells (VSMC) induced CTSO secretion. CTSO controls VSMC migration and adhesion to the extracellular matrix, and directly interacts with fibronectin (FN). CTSO depletion, or expression of the two CTSO variants, which are poorly secreted, increased the amount of FN. Moreover, CTSO depletion augmented VSMC stiffness, which was reduced by the addition of exogenous CTSO.ConclusionCollectively, our findings identify CTSO as a potential new player in arterial remodelling, regulating FN deposition and VSMC function, supporting the causal role of rare coding CTSO variants in familial forms of IA
Selection of Chemical Adsorbents and Operating Conditions for the Injection Traps of the Gas Chromatograph on Board the Dragonfly Mass Spectrometer
No full textInternational audienceThe Dragonfly mission is set to explore Titan’s surface in the mid-2030s. This relocatable lander is equipped with the Dragonfly Mass Spectrometer (DraMS) instrument. One of DraMS functioning mode is gas chromatography−mass spectrometry, to identify organic compounds in solid samples. DraMS-GC includes two independent chemical injection traps to focus the molecules released from the sample. Initially, Tenax TA was planned to be the adsorbent in the injection traps because of its heritage in previous space probes. However, Tenax TA has shown some decomposition products that challenge the identification of the molecules indigenous to the sample. In this work, the performance of another adsorbent powder, Carbotrap C, was compared to Tenax TA. Performance was evaluated in DraMS-like desorption conditions by comparing the recovery yield after adsorption and desorption of a set of 53 organic compounds of interest to Titan. Recovery with Carbotrap C was either similar or better than with Tenax TA for 79% of compounds. This recovery yield was further improved by increasing the desorption temperature. DraMS low desorption flow rate appears to be the most limiting parameter for recovery. Desorption from both Tenax TA and Carbotrap C led to partial but comparable racemization for three of the four amino acids that were enantiomerically resolved. Together, these results led to the integration of Carbotrap C in one of the DraMS injection traps
Evidence of Fukushima fallout in the area affected by wildfires in Kamaishi (Iwate Prefecture, Tohoku Region, Japan): Implications for future environmental research using radionuclide tracers
No full textInternational audienceSignificant deposition of radiocesium including 134Cs and 137Cs occurred in March 2011 following the Fukushima nuclear accident across vast regions of Northeastern Japan. However, as most studies focused on fallout that took place in the Fukushima Prefecture, much less information is available on the situation that prevails further to the North, in other parts of the Tohoku Region of Japan. In this context, the current research investigated the occurrence of fallout radionuclides (including natural 210 Pb-xs as well as artificial 134Cs and 137Cs) in burned and unburned soil profiles as well as in a range of surface soil and sediment samples collected in the region of Kamaishi (Iwate Prefecture, Tohoku Region, Japan) affected by wildfires in 2017. Results show that 210Pb-xs and 137Cs may be used as tracers of sediment sources across landscapes affected by wildfires in this region. Furthermore, the soil profile analysis demonstrated that all analysed fallout radionuclides were found enriched in the burned vs. unburned profiles, due to the incorporation of radionuclides trapped by vegetation into the ash after the fire. The detection of 134 Cs in the uppermost 0-5 cm depth layer in all investigated soil profiles also allowed to demonstrate the occurrence of significant Fukushima fallout of 134Cs and 137Cs in this region (roughly of the same order of magnitude as the fallout associated with the nuclear atmospheric tests in the 1960s). In the future, both sources of fallout should be considered to provide relevant interpretations when examining radionuclide data found in environmental samples collected in vast regions of Northeastern Japan. The analysis of 134Cs should also be encouraged to document the sources of fallout in these regions as long as this short-lived radionuclide remains detectable (i.e., theoretically by 2031)
Electromagnetic phenomena associated with dust particle dynamics in a simulated Martian atmosphere: an experimental study
No full textInternational audienceElectromagnetic phenomena associated with dust particle collisions contribute to the local electrostatic processes within Martian dust storms, impacting surface interactions and posing potential risks to spacecraft and instruments. This study investigates the generation and characteristics of electromagnetic discharges under controlled laboratory conditions designed to approximate key aspects of the Martian atmosphere. Experiments were conducted in a vacuum chamber, replicating Martian atmospheric conditions with CO2 at low pressure. A 3D-printed dust chamber was used to create dust vortices with several materials including sand particles, and Martian regolith analogs of varying particle sizes. Electromagnetic signals generated during dust collisions were measured using the Dust Complex module developed for the ExoMars-2022 landing mission. Results of the laboratory experiments demonstrate distinct discharge characteristics across different materials, influenced by particle size, composition, and morphology. Signals exhibited variations in amplitude, frequency, and waveform, reflecting the complex interactions between dust particles in a CO2 environment under low-pressure conditions. Comparative analysis with prior studies under earth conditions highlights the role of the Martian atmosphere in enhancing charge transfer processes. These findings provide new insights into the electrostatic environment of Martian dust storms and contribute to understanding electromagnetic interference risks for future exploration missions
Advanced insights into biomass burning aerosols during the 2023 Canadian wildfires from dual-site Raman and fluorescence lidar observations
No full textInternational audienceThis study presents lidar observations of long-range transported biomass burning aerosol (BBA) plumes from the exceptional 2023 Canadian wildfire season, recorded between May and September at the ATOLL observatory (France) and the GPI site (Russia). ATOLL operates a multi-wavelength Raman lidar with 3 polarization channels (355, 532 and 1064 nm) and a single fluorescence channel at 466 nm. GPI uses a fluorescence lidar with 5 broadband fluorescence channels excited by 355 nm. The dual-site dataset combines multi-wavelength elastic scattering and depolarization measurements with fluorescence observations, enabling a comprehensive characterization of BBA properties in the free troposphere (FT) and upper troposphere–lower stratosphere (UTLS). UTLS layers exhibit higher particle depolarization ratios, slightly lower lidar ratios, lower extinction- and backscatter-related Angström exponents, and a redshift in fluorescence spectral peaks. Cross-site comparisons show consistent fluorescence magnitudes and spectral shapes, highlighting the potential of coordinated multi-lidar fluorescence observations. Correlation analysis indicates that depolarization ratio, extinction-related Angström exponent, and fluorescence color ratio are moderately (r2 ≈ 0.61–0.68) correlated with layer altitude, however, this correlation is not sufficient to confirm a solid altitude dependence. It is likely that altitude is an intermediate variable linked to other controlling factors such as injection height of the plume, in-layer temperature and the plume origin. In addition, we observed BBAs showing no clear hygroscopic growth at RH of 90 %–100 % and statistically low RH values in the detected nearly 100 layers, suggesting aged BBAs, which were typically considered as hygroscopic, may have limited water uptake capability