Indo-Pacific tropical island streams are home to freshwater pipefish ( spp., Syngnathidae). Otoliths were used to uncover life history traits in four species, including a New Caledonian endemic.
View Article and Find Full Text PDFThe release of lanthanides (Ln) into the environment has increased in recent decades due to their expanding applications in society. Studying their toxicity in aquatic ecosystems is urgent and challenging, with contradictory evidence presented in the literature. This study compared the biodistribution of La and Gd in Daphnia magna exposed to sub-chronic conditions and developed the first Toxicokinetic-Toxicodynamic (TKTD) model for these lanthanides with this model crustacean.
View Article and Find Full Text PDFDeciphering the fossil record of cyanobacteria is crucial to understand their role in the chemical and biological evolution of the early Earth. They profoundly modified the redox conditions of early ecosystems more than 2.4 Ga ago, the age of the Great Oxidation Event (GOE), and provided the ancestor of the chloroplast by endosymbiosis, leading the diversification of photosynthetic eukaryotes.
View Article and Find Full Text PDFEnviron Sci Process Impacts
August 2023
While our awareness of the toxicity of rare earth elements to aquatic organisms increases, our understanding of their direct interaction and accumulation remains limited. This study describes the acute toxicity of lanthanum (La) and gadolinium (Gd) in neonates and discusses potential modes of action on the basis of the respective patterns of biodistribution. Ecotoxicological bioassays for acute toxicity were conducted and dissolved metal concentrations at the end of the tests were determined.
View Article and Find Full Text PDFNon-invasive multi-scale and multimodal 3D characterization of heterogeneous or hierarchically structured intact mesoscale samples is of paramount importance in tackling challenging scientific problems. Scanning hard X-ray tomography techniques providing simultaneous complementary 3D information are ideally suited to such studies. However, the implementation of a robust on-site workflow remains the bottleneck for the widespread application of these powerful multimodal tomography methods.
View Article and Find Full Text PDFThe acquisition of photosynthesis is a fundamental step in the evolution of eukaryotes. However, few phototrophic organisms are unambiguously recognized in the Precambrian record. The in situ detection of metabolic byproducts in individual microfossils is the key for the direct identification of their metabolisms.
View Article and Find Full Text PDFPigment organelles of vertebrates belong to the lysosome-related organelle (LRO) family, of which melanin-producing melanosomes are the prototypes. While their anabolism has been extensively unraveled through the study of melanosomes in skin melanocytes, their catabolism remains poorly known. Here, we tap into the unique ability of crab spiders to reversibly change body coloration to examine the catabolism of their pigment organelles.
View Article and Find Full Text PDFAlzheimer's disease (AD) is the most common cause of dementia, costing about 1% of the global economy. Failures of clinical trials targeting amyloid-β protein (Aβ), a key trigger of AD, have been explained by drug inefficiency regardless of the mechanisms of amyloid neurotoxicity, which are very difficult to address by available technologies. Here, we combine two imaging modalities that stand at opposite ends of the electromagnetic spectrum, and therefore, can be used as complementary tools to assess structural and chemical information directly in a single neuron.
View Article and Find Full Text PDFUranium exposure can lead to neurobehavioral alterations in particular of the monoaminergic system, even at non-cytotoxic concentrations. However, the mechanisms of uranium neurotoxicity after non-cytotoxic exposure are still poorly understood. In particular, imaging uranium in neurons at low intracellular concentration is still very challenging.
View Article and Find Full Text PDFThe impressive progress in the performance of synchrotron radiation sources is nowadays driven by the so-called `ultimate storage ring' projects which promise an unprecedented improvement in brightness. Progress on the detector side has not always been at the same pace, especially as far as soft X-ray 2D detectors are concerned. While the most commonly used detectors are still based on microchannel plates or CCD technology, recent developments of CMOS (complementary metal oxide semiconductor)-type detectors will play an ever more important role as 2D detectors in the soft X-ray range.
View Article and Find Full Text PDFBio-imaging techniques alternative to fluorescence microscopy are gaining increasing interest as complementary tools to visualize and analyze biological systems. Among them, X-ray fluorescence microspectroscopy provides information on the local content and distribution of heavy elements ( ≥ 14) in cells or biological samples. In this context, similar tools to those developed for fluorescence microscopy are desired, including chemical probes or tags.
View Article and Find Full Text PDFA new multi-platform freeware has been developed for the processing and reconstruction of scanning multi-technique X-ray imaging and tomography datasets. The software platform aims to treat different scanning imaging techniques: X-ray fluorescence, phase, absorption and dark field and any of their combinations, thus providing an easy-to-use data processing tool for the X-ray imaging user community. A dedicated data input stream copes with the input and management of large datasets (several hundred GB) collected during a typical multi-technique fast scan at the Nanoscopium beamline and even on a standard PC.
View Article and Find Full Text PDFThe XPAD3S-CdTe, a CdTe photon-counting pixel array detector, has been used to measure the energy and the intensity of the white-beam diffraction from a lysozyme crystal. A method was developed to calibrate the detector in terms of energy, allowing incident photon energy measurement to high resolution (approximately 140 eV), opening up new possibilities in energy-resolved X-ray diffraction. In order to demonstrate this, Laue diffraction experiments were performed on the bending-magnet beamline METROLOGIE at Synchrotron SOLEIL.
View Article and Find Full Text PDFBiological structures can now be investigated at high resolution by high-pressure X-ray macromolecular crystallography (HPMX). The number of HPMX studies is growing, with applications to polynucleotides, monomeric and multimeric proteins, complex assemblies and even a virus capsid. Investigations of the effects of pressure perturbation have encompassed elastic compression of the native state, study of proteins from extremophiles and trapping of higher-energy conformers that are often of biological interest; measurements of the compressibility of crystals and macromolecules were also performed.
View Article and Find Full Text PDFXPAD3S is a single-photon-counting chip developed in collaboration by SOLEIL Synchrotron, the Institut Louis Néel and the Centre de Physique de Particules de Marseille. The circuit, designed in the 0.25 microm IBM technology, contains 9600 square pixels with 130 microm side giving a total size of 1 cm x 1.
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