I.C.E.: a Transportable Atomic Inertial Sensor for Test in Microgravity

We present our the construction of an atom interferometer for inertial sensing in microgravity, as part of the I.C.E. (\textit{Interf\'{e}rom\'{e}trie Coh\'{e}rente pour l'Espace}) collaboration. On-board laser systems have been developed based on fibre-optic components, which are insensitive to mechanical vibrations and acoustic noise, have sub-MHz linewidth, and remain frequency stabilised for weeks at a time. A compact, transportable vacuum system has been built, and used for laser cooling and magneto-optical trapping. We will use a mixture of quantum degenerate gases, bosonic $^{87}$Rb and fermionic $^{40}$K, in order to find the optimal conditions for precision and sensitivity of inertial measurements. Microgravity will be realised in parabolic flights lasting up to 20s in an Airbus. We show that the factors limiting the sensitivity of a long-interrogation-time atomic inertial sensor are the phase noise in reference frequency generation for Raman-pulse atomic beam-splitters and acceleration fluctuations during free fall

Comorbidity between lung cancer and COVID-19 pneumonia: role of immunoregulatory gene transcripts in high ACE2-expressing normal lung

ACE2 expression; COVID-19; CancerExpresión ACE2; COVID-19; CáncerExpressió ACE2; COVID-19; CàncerBackground: SARS-CoV-2 (COVID-19) elicits a T-cell antigen-mediated immune response of variable efficacy. To understand this variability, we explored transcriptomic expression of angiotensin-converting enzyme 2 (ACE2, the SARS-CoV-2 receptor) and of immunoregulatory genes in normal lung tissues from patients with non-small cell lung cancer (NSCLC). Methods: This study used the transcriptomic and the clinical data for NSCLC patients generated during the CHEMORES study [n = 123 primary resected (early-stage) NSCLC] and the WINTHER clinical trial (n = 32 metastatic NSCLC). Results: We identified patient subgroups with high and low ACE2 expression (p = 1.55 × 10−19) in normal lung tissue, presumed to be at higher and lower risk, respectively, of developing severe COVID-19 should they become infected. ACE2 transcript expression in normal lung tissues (but not in tumor tissue) of patients with NSCLC was higher in individuals with more advanced disease. High-ACE2 expressors had significantly higher levels of CD8+ cytotoxic T lymphocytes and natural killer cells but with presumably impaired function by high Thymocyte Selection-Associated High Mobility Group Box Protein TOX (TOX) expression. In addition, immune checkpoint-related molecules – PD-L1, CTLA-4, PD-1, and TIGIT – are more highly expressed in normal (but not tumor) lung tissues; these molecules might dampen immune response to either viruses or cancer. Importantly, however, high inducible T-cell co-stimulator (ICOS), which can amplify immune and cytokine reactivity, significantly correlated with high ACE2 expression in univariable analysis of normal lung (but not lung tumor tissue). Conclusions: We report a normal lung immune-tolerant state that may explain a potential comorbidity risk between two diseases – NSCLC and susceptibility to COVID-19 pneumonia. Further, a NSCLC patient subgroup has normal lung tissue expressing high ACE2 and high ICOS transcripts, the latter potentially promoting a hyperimmune response, and possibly leading to severe COVID-19 pulmonary compromise.FundingThe authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The research leading to these results on the CHEMORES study data, an initiative from the Chemotherapy resistance consortium, has received funding from the European Union Sixth Framework (FP6) Integrated Project. The research on the WINTHER trial data leading to these results has received funding from the European Union Seventh Framework Program (FP7) (WINTHER: FP7/2007-2013 under grant agreement n°306125). WINTHER, an initiative from the WIN Consortium, was funded in part by ARC Foundation for cancer research (France), Pfizer Oncology, Lilly France SAS, and Novartis Pharmaceuticals Corporation. Funded in part by The FERO/J.P. Morgan Private Bank Clinical Oncology Research Grant, National Cancer Institute grant P30 P30-CA023100 (RK), Israeli Science Foundation grant 1188/16 (ER), Instituto Salud Carlos III – Programa Rio Hortega Contract grant CM15/00255 (EF) and Canadian Institutes for Health Research (grant MOP-142281, GB) and the Canadian Cancer Society (grant 703811, GB)

Plant peroxidases : biochemistry and physiology

Resistant (Reba B50) and susceptible (Acala 44) cotton plants were investigated for intratissular growth of bacterial populations and peroxidase (POx) activity, after infection of cotyledons with races 18 or 20 from #Xanthomonas (#Axonopodis$) campestris$ pv. #malvacearum$. Considerable multiplication of the bacterial population was noticed in the compatible interaction (Acala 44 / Xcm race 18) ; it was much lower during the incompatible interaction when race 18 was infiltrated into cotyledons of Reba B50. An intermediate level of bacterial growth was obtained when Reba B50 was infiltrated with race known to overcome resistance of this line. High increase in POx activity occurred into the infected cotyledons during incompatible interaction, while the increase was much lower when the interactions were compatible. On leaves, a similar and significant difference in enzyme activity was also observed indicating that the "peroxidase response" was systemically induced in entire resistant plants. Five isoperoxidases were evidenced by IEF in both lines, whether they were infected or not. But only two of them accounted for the increase in activity in infected resistant cotyledons. Microscopy revealed that POx activity, detected at the infection sites two hours after infiltration of the resistant line was mainly located in cell walls and the middle lamella bordering intercellular spaces. Our data indicate that bacterial infection of cotton plants enhanced the activity of two of the preexistent isoperoxidases in resistant plants and suggest that stimulation of POx activity is associated with resistance mechanisms. (Résumé d'auteur

I.C.E.: An Ultra-Cold Atom Source for Long-Baseline Interferometric Inertial Sensors in Reduced Gravity

The accuracy and precision of current atom-interferometric inertialsensors rival state-of-the-art conventional devices using artifact-based test masses . Atomic sensors are well suited for fundamental measurements of gravito-inertial fields. The sensitivity required to test gravitational theories can be achieved by extending the baseline of the interferometer. The I.C.E. (Interf\'erom\'etrie Coh\'erente pour l'Espace) interferometer aims to achieve long interrogation times in compact apparatus via reduced gravity. We have tested a cold-atom source during airplane parabolic flights. We show that this environment is compatible with free-fall interferometric measurements using up to 4 second interrogation time. We present the next-generation apparatus using degenerate gases for low release-velocity atomic sources in space-borne experiments

Flavonoids accumulate in cell walls, middle lamellae and callose-rich papillae during an incompatible interaction between Xanthomonas campestris pv. malvacearum and cotton

Interactions between cotton cotyledons and #Xanthomonas campestris pv. #malvacearum were examined. During an incompatible interaction, fluorescence microscopy revealed that flavonoid compounds accumulated within 10 h after inoculation. Electron micrographs showed ultrastructural modifications of cells that exhibited an intense fluorescence suggesting the presence of flavonoids. Phenol-like molecules were produced by cells of infection sites and were found in paramural areas within papillae enriched with callose and in host cell walls and middle lamellae. Histochemistry showed that peroxidase activity and terpenoids were detected in the infected resistant plants, 4 and 48 h after inoculation, respectively. In contrast, no changes in the deposits of lignin, suberin, and catechin were seen in either the infected susceptible or resistant lines. We suggest that early flavonoid accumulation is associated with the hypersensitive reaction of cotton cotyledons to #X. campestris pv. #malvacearum. The activity of wall-bound peroxidases may play a role in the incorporation of flavonoids in cell walls and paramural papillae. (Résumé d'auteur

Solving Uncalibrated Photometric Stereo using Total Variation

International audienceEstimating the shape and appearance of an object, given one or several images, is still an open and challenging research problem called 3D-reconstruction. Among the different techniques available, photometric stereo (PS) produces highly accurate results when the lighting conditions have been identified. When these conditions are unknown, the problem becomes the so-called uncalibrated PS problem, which is ill-posed. In this paper, we will show how total variation can be used to reduce the ambiguities of uncalibrated PS, and we will study two methods for estimating the parameters of the generalized bas-relief ambiguity. These methods will be evaluated through the 3D-reconstruction of real-world objects

XRCC1 interacts with the p58 subunit of DNA Pol α-primase and may coordinate DNA repair and replication during S phase

Repair of single-stranded DNA breaks before DNA replication is critical in maintaining genomic stability; however, how cells deal with these lesions during S phase is not clear. Using combined approaches of proteomics and in vitro and in vivo protein–protein interaction, we identified the p58 subunit of DNA Pol α-primase as a new binding partner of XRCC1, a key protein of the single strand break repair (SSBR) complex. In vitro experiments reveal that the binding of poly(ADP-ribose) to p58 inhibits primase activity by competition with its DNA binding property. Overexpression of the XRCC1-BRCT1 domain in HeLa cells induces poly(ADP-ribose) synthesis, PARP-1 and XRCC1-BRCT1 poly(ADP-ribosyl)ation and a strong S phase delay in the presence of DNA damage. Addition of recombinant XRCC1-BRCT1 to Xenopus egg extracts slows down DNA synthesis and inhibits the binding of PCNA, but not MCM2 to alkylated chromatin, thus indicating interference with the assembly of functional replication forks. Altogether these results suggest a critical role for XRCC1 in connecting the SSBR machinery with the replication fork to halt DNA synthesis in response to DNA damage