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Spatio-temporal dynamics of macroglial cell organisation and proximity to blood vessels during postnatal development
No full textAbstract Brain cortical development results from the proliferation, differentiation, migration and maturation of many cell types. While neuronal development is well characterized, the mechanisms regulating macroglial cells (oligodendrocytes and astrocytes) development remain largely unknown. Recent works suggest that the vascular system plays a key, yet under-evaluated role in this process. To investigate this, we developed VeCell , a Fiji plugin designed to analyse the spatial organization of macroglial cells relative to blood vessels. Using immunolabeling for Sry-box transcription factor (Sox) 9 (macroglial progenitors and astrocytes) and Sox10 (oligodendrocyte lineage), we determined macroglia density, distribution and proximity to blood vessels from postnatal day (P) 1 to P60 in the somatosensory cortex. We showed that Sox9+ cells were evenly distributed across cortical layers with regular intercellular spacing. In contrast, Sox10+ cells concentrated in deeper cortical layers, and exhibited a random distribution. Vascular density and branching increased markedly between P5 and P15 and macroglial cells were closer to blood vessels from P15 onward. As a proof of concept, we used Vecell to show that astrocyte cortical distribution is preserved in MLC1-deficient mice, a model of Megalencephalic leukoencephalopathy with subcortical cysts, in which astrocyte perivascular coverage is altered. Thus, VeCell is a powerful tool to characterize and quantify macroglial cell distribution in the brain and in relation to the vasculature. It revealed distinct distribution and postnatal development patterns for astrocytes and oligodendrocytes. Table of Contents Entry VeCell: quantification of macroglial cell density, distribution, and proximity to blood vessels From P5, Sox9⁺ cells are evenly distributed, unlike Sox10⁺ cells From P15, Sox9⁺ cells are located closer to blood vessels than Sox10⁺ cells Abstract Figur
Faunal persistence and ecological flexibility in Pleistocene Southeast Asia revealed through multi-isotope analysis
No full textInternational audienceSoutheast Asia boasts some of the world's most diverse ecosystems, yet it has experienced a dramatic decline in biodiversity due to extensive deforestation in recent decades. Understanding how species adapted to past habitat loss could provide valuable insights for developing effective conservation strategies to address current threats. We apply state-of-the-art isotope measurements of enamel-bound zinc (δ66Zn) and nitrogen (δ15N enamel ) analyses to fossil mammal teeth from Coc Muoi [148 to 117 thousand years (ka) and Duoi U'Oi (70 to 60 ka)], Vietnam. Alongside published regional data (δ66Zn, δ13C, and δ18O), we explore how different taxa adapt their diets and behaviors in the face of climatic and environmental changes. We show that foraging in diverse habitats and diversifying food consumed is associated with extant species, while extinct or locally extirpated taxa show these traits to a lesser extent. We underscore the precariousness of certain species and the pressing need for robust conservation policies to safeguard Southeast Asia's biodiversity
Le Traité des Points-clefs sur le Sens Symbolique de l'Aiguière (gNad yig bum pa'i brda don)
No full textA century of agro-pastoral and forest resource management in Central Asia revealed by multiproxy analyses of the Lake Kanbeshbulak sediments
No full textInternational audienceOur contribution investigates the long-term evolution of rural agro-sylvo-pastoral systems in the mid-altitude mountains of Central Asia (southeast of the Hissar range, Uzbekistan) by analyzing the sediment infill of Lake Kanbeshbulak (alt. 1660 m.). Five interface sediment cores were extracted from the lake basin and analyzed for mineral and biological sedimentary components, along with vegetation changes. We combined palynological, sedimentological (grain-size, XRD), element geochemistry (XRF Core scanning, TOC, TN), magnetic properties (ARM, IRM, ꭓ), and chrono-stratigraphic data (210Pb, 137Cs, post-bomb 14C) to reconstruct local environmental dynamics and human land use over the last century, from 1940 to 2022. The data reveal a complex interplay between erosion dynamics and land management practices, that we compared to instrumental records of the climate variability, as well as historical records. Between 1940 and 1960, the catchment was characterized by semi-open juniper forests, modest agricultural and pastoral activity, and high detrital influx. From 1960 to 1975, forest decline and shrub expansion occurred alongside a drop in summer temperatures, without significant change in agropastoral pressure. The period from 1975 to 1990 saw a drastic reduction in forest cover and agricultural practices, coinciding with the expansion of prairie-type grasslands and a shift to coarser sediment inputs. After the country’s independence, a reversal took place: large-scale afforestation programs were implemented, livestock pressure increased, and agricultural activities returned to pre-1980 levels. Socio-political drivers, especially state-led land use planning, demographic dynamics, and rural development policies, that still require further investigations to be precisely compared to the lake record, might have played a decisive role in shaping those mid-latitude rural landscapes
Doping dependence of the dipolar correlation length scale in metallic SrTiO3
No full textInternational audienceSuperconducting domes, ubiquitous across a variety of quantum materials, are often understood as a window in which pairing is favored, opened by the fluctuations of competing orders. Yet, the understanding of how such a window closes is missing. Here, we show that inelastic neutron scattering, by quantifying a length scale associated with the dipoles correlation, ℓ0, addresses this issue. We find that, within the experimental precision, the end of the superconducting dome coincides with the end of a highly polarizable state (in which ℓ0 is longer than the interatomic distance). Thus, the superconducting dome is driven by the competition between the increase in the density of states and the inevitable collapse of the quantum paraelectric phase. This is compatible with a crucial role played by the soft ferroelectric mode in driving superconductivity. Such a scenario may also be at work in other quantum paraelectric materials, either bulk or at interfaces
Tailoring interaction ranges in atom arrays
No full textInternational audienceWe introduce a method to synthetically engineer the range of dipolar interactions in tweezer atom arrays by effectively modifying the modes of the electromagnetic vacuum with far-detuned relay atoms. We derive equations of motion for the atoms of interest after adiabatic elimination of the relay atoms. We show the effectiveness of the scheme for realistic experimental parameter regimes with circular and low-angular-momentum Rydberg atom states.</div
La Lampe résumant les Principes de l’Espace et de la Sagesse (dByings dang ye shes kyi don bsdus pa’i sgron ma)
No full textFolium in Persian and Islamic Manuscripts (15th–19th Centuries): Historical Significance and Analytical Study
No full textInternational audienceMedieval manuscripts are an essential part of Persian cultural heritage and a rich source of the country's material culture. Their study sheds light on shared materials across the Mediterranean and Near East. The practice of using blue and purple in manuscripts was popular during the Middle Ages in both Europe and Persia. Persian historical treatises describe a blue dye plant used for paper, in addition to blue indigo, although its specific terminology was previously unknown. The plant is identified as Chrozophora tinctoria (L.) A. Juss., also known as turnsole; the dye extracted from it is commonly known as folium. This study is divided into three phases: First, dye extraction techniques from C. tinctoria fruits were studied based on historical Persian recipes. Second, methods for reconstructing blue-purple paper dyes from turnsole fruits were explored, with local plants harvested in Iran during August and September, and the dyes analysed using spectroscopy, finding a good agreement to folium spectra obtained from European (central Italy) fruits of C. tinctoria. Third, folium was identified on manuscripts produced under Islamic rule in the Middle Ages. The findings suggest discussion as to whether this dye was used in Persian manuscripts too, given the notable corpus of citations in Persian historical treatises
Passeurs de livres et de savoirs: Le fonds légué par Jean-Pierre et Colette Diény à la Bibliothèque Nationale et Universitaire de Strasbourg
No full texthttps://bowushi.hypotheses.org/439La Bibliothèque Nationale et Universitaire de Strasbourg a reçu en 2015 un don de livres sur l'Asie, sur la Chine en particulier, de la part de Jean-Pierre et Colette Diény. Cette collection reflète certaines des caractéristiques de la recherche des deux sinologues et elle ouvre de nouvelles possibilités pour l'enseignement et la recherche dans le domaine de la sinologie