Portail HAL du Collège de France
Not a member yet
22122 research outputs found
Sort by
The Hox protein Antennapedia orchestrates Drosophila adult flight muscle development
No full textInternational audienceMuscle development and diversity require a large number of spatially and temporally regulated events controlled by transcription factors (TFs). Drosophila has long stood as a model to study myogenesis due to the highly conserved key TFs involved at all stages of muscle development. While many studies focused on the diversification of Drosophila larval musculature, how distinct adult muscle types are generated is much less characterized. Here, we identify an essential regulator of Drosophila thoracic flight muscle development, the Hox TF Antennapedia (Antp). Correcting a long-standing belief that flight muscle development occurs without the input of Hox TFs, we show that Antp intervenes at several stages of flight muscle development, from the establishment of the progenitor pool in the embryo to myoblast differentiation in the early pupa. Furthermore, the precisely regulated clearance of Hox in the developing flight muscle fibers is required to allow for fibrillar muscle fate diversification, setting these muscles apart from all other adult tubular muscle types
Erratum: "First Detection of the Molecular Cloud Population in the Extended Ultraviolet Disk of M83" (2022, ApJ, 941, 3)
No full textInternational audienceWe revisit the claimed detection of a new cosmic microwave background (CMB) foreground based on the correlation between low-redshift Two Micron All Sky Survey Redshift Survey (2MRS) galaxies and CMB temperature maps from the Planck and Wilkinson Microwave Anisotropy Probe missions. We reproduce the reported measurements but argue that the original analysis significantly underestimated the uncertainties. We cross-correlate the 2MRS galaxy positions with simulated CMB maps and show that the correlation measured with the real data for late-type spiral galaxies at angular scales θ ≥ 0.°1 and redshift cz < 4500 km s‑1 is consistent with zero at the 1.7σ level or less, depending on the exact CMB map and simulation construction. This was the sample that formed the basis for the original detection claim. For smaller angular separations the results are not robust to galaxy type or CMB cleaning method, and we are unable to draw firm conclusions. The original analysis did not propose a specific, falsifiable physical correlation mechanism, and it is impossible to rule out any contribution from an underlying physical effect. However, given our calculations, the lack of signal from expanding the redshift range, and the lack of corroboration from other galaxy surveys, we do not find the evidence for a new CMB foreground signal compelling
Deconvolution of JWST/MIRI Images: Applications to an Active Galactic Nucleus Model and GATOS Observations of NGC 5728
No full textInternational audienceThe superb image quality, stability, and sensitivity of JWST permit deconvolution techniques to be pursued with a fidelity unavailable to ground-based observations. We present an assessment of several deconvolution approaches to improve image quality and mitigate the effects of the complex JWST point-spread function (PSF). The optimal deconvolution method is determined by using WebbPSF to simulate JWST's complex PSF and MIRISim to simulate multiband JWST/Mid-Infrared Imager Module (MIRIM) observations of a toy model of an active galactic nucleus (AGN). Five different deconvolution algorithms are tested: (1) Kraken deconvolution, (2) Richardson–Lucy, (3) the adaptive imaging deconvolution algorithm, (4) sparse regularization with the Condat–Vũ algorithm, and (5) iterative Wiener filtering and thresholding. We find that Kraken affords the greatest FWHM reduction of the nuclear source of our MIRISim observations for the toy AGN model while retaining good photometric integrity across all simulated wave bands. Applying Kraken to Galactic Activity, Torus, and Outflow Survey (GATOS) multiband JWST/MIRIM observations of the Seyfert 2 galaxy NGC 5728, we find that the algorithm reduces the FWHM of the nuclear source by a factor of 1.6–2.2 across all five filters. Kraken images facilitate detection of extended nuclear emission ∼2.″5 (∼470 pc, position angle ≃ 115°) in the SE–NW direction, especially at the longest wavelengths. We demonstrate that Kraken is a powerful tool to enhance faint features otherwise hidden in the complex JWST PSF
AGN feedback in the Local Universe: Multiphase outflow of the Seyfert galaxy NGC 5506
No full textInternational audienceWe present new optical GTC/MEGARA seeing-limited (0.9″) integral-field observations of NGC 5506, together with ALMA observations of the CO(3 − 2) transition at a 0.2″ (∼25 pc) resolution. NGC 5506 is a luminous (bolometric luminosity of ∼1044 erg s−1) nearby (26 Mpc) Seyfert galaxy, part of the Galaxy Activity, Torus, and Outflow Survey (GATOS). We modelled the CO(3 − 2) kinematics with 3DBAROLO, revealing a rotating and outflowing cold gas ring within the central 1.2 kpc. We derived an integrated cold molecular gas mass outflow rate for the ring of ∼8 M⊙ yr−1. We fitted the optical emission lines with a maximum of two Gaussian components to separate rotation from non-circular motions. We detected high [OIII]λ5007 projected velocities (up to ∼1000 km s−1) at the active galactic nucleus (AGN) position, decreasing with radius to an average ∼330 km s−1 around ∼350 pc. We also modelled the [OIII] gas kinematics with a non-parametric method, estimating the ionisation parameter and electron density in every spaxel, from which we derived an ionised mass outflow rate of 0.076 M⊙ yr−1 within the central 1.2 kpc. Regions of high CO(3 − 2) velocity dispersion, extending to projected distances of ∼350 pc from the AGN, appear to be the result from the interaction of the AGN wind with molecular gas in the galaxy's disc. Additionally, we find the ionised outflow to spatially correlate with radio and soft X-ray emission in the central kiloparsec. We conclude that the effects of AGN feedback in NGC 5506 manifest as a large-scale ionised wind interacting with the molecular disc, resulting in outflows extending to radial distances of 610 pc
Autumn lambing in the Mediterranean: the ancient history of a sustainable practice
No full textInternational audienceAgropastoral systems in the Mediterranean take a great variety of forms in response to a wide range of climatic, orographic and socioeconomic contexts. The predominance of caprines (sheep and goat) is a frequent common feature, and a particularity is the existence of autumn lambing. Annual rhythms of pastoral systems are strongly determined by animal births season, which defines the annual availability of animal products (milk in particular) and the organization of agropastoral tasks. In temperate latitudes, ewes alternate on an annual scale between a period of fertility and a sexual rest. This reproductive cycle, inherited from their wild ancestor, is mainly driven by the photoperiod. In contrast to the dominant pattern of spring lambing in today’s temperate Europe, in the Mediterranean area lambing can also be scheduled in autumn, bringing benefits in terms of use of natural resources. Autumnal lambing in the Mediterranean is enabled by the conjunction of three factors: (i) the physiological capability of some Mediterranean breeds for an “out-of-season” fertility period; (ii) intentional scheduling by the herder, by separating females and males and reuniting them in the spring; (iii) abundant forage resources to support autumn lactation: in present-day Mediterranean climate, autumnal rains create favorable conditions. In this regard, autumnal lambing constitutes a form of sustainable pastoralism in the Mediterranean area. Recent studies involving stable isotope analysis in sheep teeth showed autumn lambing in the early and middle Neolithic (6th and 4th mill. BCE) in the northwestern Mediterranean, suggesting that all three conditions were met at least in different occasions in the past. We will present news findings on sheep birth season and the occurrence of autumn lambing in Neolithic contexts across the northern margin of the Mediterranean over a broad longitudinal range from North Macedonia and Greece to southern France
Diachronic and geographic diversity of the femoral structure in Neanderthals
No full textInternational audienceNeanderthal femora exhibit documented morphological differences compared to those of other Homo [1-2], including Homo sapiens, particularly in the internal structure of their diaphysis. However, comprehending the intra-specific diversity of femoralstructure among Neanderthals is crucial for elucidating the broader diversity within the Homo genus throughout the Middle and Late Pleistocene. This study aims to comprehensively document the diversity of femoral structure among Neanderthals, both chronologically and geographically.We conducted an analysis of the internal structure of femoral diaphyses of Neanderthal individuals from the Levant and Northern, Central, and Western Europe. The study incorporates both previously published and newly acquired micro-CT data spanning from MIS 7 to MIS 3, as well as one Middle Pleistocene Homo specimen. Using the morphomap R routine [3], we evaluated the diaphyseal structure by using traditional cross-sectional properties and applied a 2D landmark-based geometric morphometricapproach to delve into the endosteal, periosteal, and cross-sectional shape characteristics. These analyses were conducted at three distinct locations along the femoral diaphysis—subtrochanteric (80% of biomechanical length from the distal end), midshaft (50%), and mid-distal (35%).While conventional measurements of cross-sectional properties did not reveal clear trends among chronological and geographical groupings, multivariate analysis from the morphometric approach to cross-sectional shape allows us to define distinctclusters. Late Neanderthals of MIS 4 to 3 from Western and Northern Europe appear to differentiate from earlier specimens of Middle Pleistocene Homo and MIS 7 to 5 Neandertals. These differences result in Late Neandertals having more circular cross-sections in the proximal diaphysis and a medial buttress that is both more developed at midshaft and emerges from the mid-distal diaphysis.The present study therefore reveals clear chronological diversity in the structural patterns of Neanderthal femora. Few specimens from Northern Europe also exhibit deviations from the seemingly homogeneous pattern observed among LateNeanderthals, raising the possibility that these are idiosyncratic variations or regional differences
An approximation of the squared Wasserstein distance and an application to Hamilton-Jacobi equations
No full textWe provide a simple approximation of the squared Wasserstein distance on R^d when one of the two measures is fixed. This approximation converges locally uniformly. More importantly, at points where the differential of the squared Wasserstein distance exists, it attracts the differentials of the approximations at nearby points. Our method relies on the Hilbertian lifting of PL Lions and on the regularization in Hilbert spaces of Lasry and Lions. We then provide an application of this result by using it to establish a comparison principle for an Hamilton-Jacobi equation on the set of probability measures
Mark J. Sedgwick, Traditionalism: The Radical Project for Restoring Sacred Order, 2024
No full textInternational audienc
Base de données PRIDE - Project PXD047160
No full textInternational audienceFor immunoprecipitation, we used ORF1p (abcam, ab245122) and IgG rabbit (abcam, ab172730) antibodies. The antibodies were coupled to magnetic beads using the Dynabeads® Antibody Coupling Kit (Invitogen, 14311D) according to the manufacturer's recommendations. We used 5μg of antibody for 1 mg of beads and used 1.5mg of beads for IP. Individual mouse brain lysate previously homogenized using dounce and sonicated were incubated with ORF1p or IgG-control coupled beads and a small fraction was kept as input. Each of these two tubes containing coupled beads and brain lysates were diluted in 5 mL ml with buffer (10 mM Tris HCl, 150 mM NaCl, and protease inhibitor. The samples were then incubated overnight on a wheel at 4°C. Samples were then washed 3 times with 1 ml buffer (10 mM Tris HCl pH 8, 150 mM NaCl) using a magnet and then resuspended in the same buffer. After 3 washes with 1mL buffer the beads were washed twice with 100 µL on 25 mM NH4HCO3 (ABC buffer). Finally, beads were resuspended in 100 μl of 25mM ABC buffer and digested by adding 0.20 μg of trypsine/LysC (Promega) for 1 hour at 37 °C. A second round of digestion was applied simultaneously on the beads by adding 100 µL of 25 mM ABC buffer and to the previous digest by adding 0.2µg of trypsin/Lysc for 1 hour at 37 °C. Samples were then loaded into homemade C18 StageTips packed by stacking three AttractSPE® disk (#SPE-Disks-Bio-C18-100.47.20 Affinisep) into a 200 µL micropipette tip for desalting. Peptides were eluted using a ratio of 40:60 CH3CN:H2O + 0.1% formic acid and vacuum concentrated to dryness with a SpeedVac device. Peptides were reconstituted in 10 µL of injection buffer in 0.3% trifluoroacetic acid (TFA) before liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis