Petrographical and Mineralogical Applications of Raman Mapping

Raman spectroscopy has undergone rapid development over the last few decades. The ability to acquire a spectrum in only a few tens of milliseconds allows use of Raman mapping as a routine technique. However, with respect to classical single spectrum measurement, this technique is not still as widely used as it could be, in particular for mineralogy and petrography. Here, we explain the advantages of Raman mapping for obtaining additional information compared to single spot analyses. The principle and the limits of the technique are first explained in 2D and 3D. Data processing techniques are then described using different types of rocks and minerals to demonstrate the utility of Raman mapping for obtaining information about the general composition, identification of small phases, as well as for distinguishing minerals that are spectrally very close. More “exotic” uses of the collected signal are also described. Finally, a gallery of images from representative samples is used to illustrate the discussion

Habitability on Mars from a Microbial Point of View

International audienceExtraterrestrial habitability is a complex notion. We briefly review what is known about the origin of life on Earth, that is, life based on carbon chemistry and water. We then discuss habitable conditions (past and present) for established life and for the survival of microorganisms. Based on these elements, we propose to use the term habitable only for conditions necessary for the origin of life, the proliferation of life, and the survival of life. Not covered by this term would be conditions necessary for prebiotic chemistry and conditions that would allow the recognition of extinct or hibernating life. Finally, we apply this concept to the potential emergence of life on Mars where suitable conditions for life to start, proliferate, and survive have been heterogeneous throughout its history. These considerations have a profound impact on the nature and distribution of eventual traces of martian life, or any precursor, and must therefore inform our search-for-life strategies. Key Words: Mars-- Microbial life--Punctuated habitabilit

The CaliPhoto Method

International audienceWe propose an innovative method based on photography and image processing of interdisciplinary relevance, permitting the uncomplicated and inexpensive evaluation of material properties. This method-CaliPhoto-consists of using a dedicated colour plate with a specific design, placed in the field of view of a photograph of the material to be characterized. A specific image processing workflow is then applied to obtain colour vectors independent of illumination conditions. The method works using commercial colour cameras (e.g., smartphone cameras), and the colour plate can be printed on any colour printer. Herein, we describe the principle of the method and demonstrate that it can be used to describe and compare samples, identify materials or make relatively precise concentration measurements. The CaliPhoto method is highly complementary to any scientific research and may find applications across a range of domains, from planetary science to oceanography. The method may also be widely used in industry

2018 MAX-C/ExoMars Mission: The Orleans Mars-Analogue Rock Collection for Instrument Testing

International audienceIn order to reply to the exobiological goals of the 2018 MAX-C/ExoMars mission, the Orléans-OSUC analogue rock collection and database contains well characterised Mars analogue rocks and minerals for use in instrument testing and in situ missions

Knockout of Vdac1 activates hypoxia-inducible factor through reactive oxygen species generation and induces tumor growth by promoting metabolic reprogramming and inflammation

BACKGROUND: Mitochondria are more than just the powerhouse of cells; they dictate if a cell dies or survives. Mitochondria are dynamic organelles that constantly undergo fusion and fission in response to environmental conditions. We showed previously that mitochondria of cells in a low oxygen environment (hypoxia) hyperfuse to form enlarged or highly interconnected networks with enhanced metabolic efficacy and resistance to apoptosis. Modifications to the appearance and metabolic capacity of mitochondria have been reported in cancer. However, the precise mechanisms regulating mitochondrial dynamics and metabolism in cancer are unknown. Since hypoxia plays a role in the generation of these abnormal mitochondria, we questioned if it modulates mitochondrial function. The mitochondrial outer-membrane voltage-dependent anion channel 1 (VDAC1) is at center stage in regulating metabolism and apoptosis. We demonstrated previously that VDAC1 was post-translationally C-terminal cleaved not only in various hypoxic cancer cells but also in tumor tissues of patients with lung adenocarcinomas. Cells with enlarged mitochondria and cleaved VDAC1 were also more resistant to chemotherapy-stimulated cell death than normoxic cancer cells. RESULTS: Transcriptome analysis of mouse embryonic fibroblasts (MEF) knocked out for Vdac1 highlighted alterations in not only cancer and inflammatory pathways but also in the activation of the hypoxia-inducible factor-1 (HIF-1) signaling pathway in normoxia. HIF-1α was stable in normoxia due to accumulation of reactive oxygen species (ROS), which decreased respiration and glycolysis and maintained basal apoptosis. However, in hypoxia, activation of extracellular signal-regulated kinase (ERK) in combination with maintenance of respiration and increased glycolysis counterbalanced the deleterious effects of enhanced ROS, thereby allowing Vdac1 (-/-) MEF to proliferate better than wild-type MEF in hypoxia. Allografts of RAS-transformed Vdac1 (-/-) MEF exhibited stabilization of both HIF-1α and HIF-2α, blood vessel destabilization, and a strong inflammatory response. Moreover, expression of Cdkn2a, a HIF-1-target and tumor suppressor gene, was markedly decreased. Consequently, RAS-transformed Vdac1 (-/-) MEF tumors grew faster than wild-type MEF tumors. CONCLUSIONS: Metabolic reprogramming in cancer cells may be regulated by VDAC1 through vascular destabilization and inflammation. These findings provide new perspectives into the understanding of VDAC1 in the function of mitochondria not only in cancer but also in inflammatory diseases

Young children's understanding of disabilities: the influence of development, context and cognition

Throughout Europe, educational support for children with disabilities has moved towards a model of inclusive education. Such policy changes mean that for all children there will be an increased likelihood of working with and encountering children with differing disabilities and difficulties. Previous research had indicated that children had poorly differentiated views of developmental differences. The present study investigated children?s representations of different disabilities. Seventy-nine 8-9 and 10-11 year old Greek children from an urban school and a rural school completed an attitudes toward school inclusion rating scale and a semi-structured interview. Responses to the attitude scale provided generally positive views of educational inclusion. However, children were less positive about activities that might directly reflect upon themselves. Children?s responses in the interviews indicated that they were developing rich representations of differences and diversities. Children had the greatest understanding of sensory and physical disabilities, followed by learning disabilities. There was limited knowledge of dyslexia and hyperactivity and no child was familiar with the term autism. Both groups of children identified a range of developmental difficulties, with older children being more aware of specific learning disabilities, their origin and impact. Results are discussed in terms of children?s developing knowledge systems and the implications for educational practices

Nanoblades allow high-level genome editing in murine and human organoids

Genome engineering has become more accessible thanks to the CRISPR-Cas9 gene-editing system. However, using this technology in synthetic organs called “organoids” is still very inefficient. This is due to the delivery methods for the CRISPR-Cas9 machinery, which include electroporation of CRISPR-Cas9 DNA, mRNA, or ribonucleoproteins containing the Cas9-gRNA complex. However, these procedures are quite toxic for the organoids. Here, we describe the use of the “nanoblade (NB)” technology, which outperformed by far gene-editing levels achieved to date for murine- and human tissue-derived organoids. We reached up to 75% of reporter gene knockout in organoids after treatment with NBs. Indeed, high-level NB-mediated knockout for the androgen receptor encoding gene and the cystic fibrosis transmembrane conductance regulator gene was achieved with single gRNA or dual gRNA containing NBs in murine prostate and colon organoids. Likewise, NBs achieved 20%–50% gene editing in human organoids. Most importantly, in contrast to other gene-editing methods, this was obtained without toxicity for the organoids. Only 4 weeks are required to obtain stable gene knockout in organoids and NBs simplify and allow rapid genome editing in organoids with little to no side effects including unwanted insertion/deletions in off-target sites thanks to transient Cas9/RNP expression

Entreprises et territoires à l’épreuve de la démondialisation

International audienceThis article presents this thematic issue of the Annals of geography, dealing with the new relations that companies and territories develop in facing the consequences of deglobalization. Although the notion of "globalization" does not pose any particular problems of definition in economic geography. This is not the case for "deglobalization", whose use is still controversial. It denotes essentially a specific phase of contemporary globalization, the "crisis of globalization." A new diagram helps to clarify the respective places of globalization and deglobalization in the economic dynamics of the contemporary world. It is characterized by two simultaneous movements, but in opposite directions: the first promotes the process of opening up to the world (globalization); the second advocates more the status quo, i.e. retrenchment and closing-off from the world. Companies and territories are on the front line of this duality. In the face of rising uncertainties, in the end, companies and territories are eagerly in search of solutions to withstand the effects of the crisis