34 research outputs found
CNES Flight Experiment for Thermal Coatings Aging: THERME
No full textSimona Calarco, Centre National d'Études Spatiales (CNES), FranceStéphanie Remaury, Centre National d'Études Spatiales (CNES), FranceSophie Perraud, Centre National d'Études Spatiales (CNES), FranceJoël Gayrard, Centre National d'Études Spatiales (CNES), FranceICES202: Satellite, Payload, and Instrument Thermal ControlThe 53rd International Conference on Environmental Systems was held in Louisville, Kentucky, USA, on 21 July 2024 through 25 July 2024.The in-flight evolution of thermo-optical properties of thermal coatings is of great concern when defining the thermal control system (TCS) of spacecraft. In-flight measurements and aging tests in laboratory demonstrates that the parameter really affected by the in-orbit aging is the solar absorptivity, which often increases when coatings are under space environment conditions. To define spacecraft TCS, thermal engineers have to take into account, from beginning of life (BOL) to end of life (EOL), the thermo-optical properties evolutions of the external coatings they intend to use. Radiative surfaces sizes cope with the hottest conditions of the mission, which generally depend on the EOL properties of external coatings. But the larger the surfaces, the higher the heating power needed for the coldest conditions of the mission, which generally depend on BOL properties. Improving the knowledge of the in-orbit evolutions of the solar absorptivity of thermal coatings is consequently of paramount importance to optimize the TCS designs, and then to better master the on-board heating power consumption.
In this context, CNES has developed since 1990 a very simple and low cost experiment, called "THERME", to evaluate the degradation of space coatings in real orbital conditions. This experiment was previously carried on low Earth orbit (LEO) spacecraft such as SPOT 2 and 5, HELIOS 2A and 2B and Demeter, all removed from operational service. In the last few years, the THERME experiment design was extended for geostationary (GEO) mission typical constraints and is now flying on ATHENA-FIDUS and KOREASAT from TAS and on a telecom mission from ADS.
During the ICES 2024, we present the overall concept and design of THERME. We discuss also in methodology for exploitation of flight results of THERME, of main flight results and we identify the axes of improvement for future missions
Positively charged polymers modulate the fate of human mesenchymal stromal cells via ephrinB2/EphB4 signaling
No full textAbstractUnderstanding the mechanisms by which mesenchymal stromal cells (MSCs) interact with the physical properties (e.g. topography, charge, ζ-potential, and contact angle) of polymeric surfaces is essential to design new biomaterials capable of regulating stem cell behavior. The present study investigated the ability of two polymers (pHM1 and pHM3) with different positive surface charge densities to modulate the differentiation of MSCs into osteoblast-like phenotype via cell-cell ephrinB2/EphB4 signaling. Although pHM1 promoted the phosphorylation of EphB4, leading to cell differentiation, pHM3, characterized by a high positive surface charge density, had no significant effect on EphB4 activation or MSCs differentiation. When the MSCs were cultured on pHM1 in the presence of a forward signaling blocking peptide, the osteoblast differentiation was compromised. Our results demonstrated that the ephrinB2/EphB4 interaction was required for MSCs differentiation into an osteoblast-like phenotype and that the presence of a high positive surface charge density altered this interaction
Observed prevalence and characterization of fluoroquinolone-resistant and multidrug-resistant bacteria in loggerhead sea turtles (Caretta caretta) from the Adriatic Sea
No full textBackground/Objectives: Antimicrobial resistance (AMR) is a major global health concern with profound implications for human, animal, and environmental health. Marine ecosystems are emerging as reservoirs of resistant bacteria due to contamination from anthropogenic activities. This study aimed to investigate fluoroquinolone-resistant and multidrug-resistant bacteria in loggerhead sea turtles (Caretta caretta). Methods: Cloacal swabs were collected from 28 loggerhead sea turtles at a rescue center in southern Italy. Swabs were cultured in nutrient media supplemented with enrofloxacin. Bacterial isolates underwent identification by MALDI-TOF, antimicrobial susceptibility testing, and assessment for multidrug resistance. Conjugation experiments evaluated the transferability of enrofloxacin resistance. Results: Thirty-six enrofloxacin-resistant bacterial strains were isolated from 22 turtles. The identified species included Vagococcus fluvialis (13 strains), Citrobacter freundii (5), Escherichia coli (6), and Pseudomonas mendocina (4). Thirty-five isolates exhibited multidrug resistance, with resistance to critically important antibiotics such as imipenem observed in C. freundii and Enterobacter faecium. Conjugation experiments showed no transfer of resistance genes. Conclusions: The study highlights the prevalence of fluoroquinolone-resistant and multidrug-resistant bacteria in C. caretta, implicating marine environments as reservoirs of AMR. The findings underscore the need for stricter regulation of antimicrobial use and monitoring of resistance dissemination in marine ecosystems. These results contribute to understanding AMR dynamics within the One Health framework, emphasizing the interconnectedness of environmental, animal, and human health
Author's response: on process, discrepancy, pursuing the non-obvious, and not missing the forest
No full textThe best gift an author can receive is a serious reader’s attention, and here we find much reason to be grateful. Van Meegdenburg, Lombard, and Anria have each read the book with care, reported faithfully what we wer
Author response: CRISPR-mediated genetic interaction profiling identifies RNA binding proteins controlling metazoan fitness
No full textGenome wide identification of mutational hotspots in the apicomplexan parasite neospora caninum and the implications for virulence
No full text© The Author(s) 2018. Neospora caninum is an apicomplexan parasite responsible for neosporosis, a disease causing hind limb paralysis in dogs and abortion in cattle, resulting in substantial economic losses to beef and dairy industries. Marked differences in pathogenicity exist between N. caninum strains suggesting that intrinsic genetic differences exist between them. These differences likely exist in genes expressed during the tachyzoite lifecycle stage which is responsible for the pathogenesis of neosporosis. An improved understanding of these genetic differences is essential to understanding N. caninum virulence, though such knowledge is scarce. Using a variant detection workflow we compared the tachyzoite transcriptomes of two N. caninum strains with different virulence properties: NC-Liverpool (virulent) and NC-Nowra (avirulent). This workflow identified 3130 SNPs and 6123 indels between the strains, and nine markers capturing 30 variants were Sanger sequenced for both strains. Sequencing of these loci was extended to an additional eight strains and subsequent phylogenetic analysis supported a genetic population structure comprised of two major clades with no geographical segregation. Sequence polymorphisms within coding regions of tachyzoiteassociated genes were concentrated on chromosomes XI and XII, with 19 distinct tachyzoite-associated SNP hotspot regions identified within coding regions of the N. caninum nuclear genome. The variants were predominantly located in loci associated with protein binding, protein-protein interactions, transcription, and translation. Furthermore, 468 nonsynonymous SNPs identified within protein-coding genes were associated with protein kinase activity, protein binding, protein phosphorylation, and proteolysis. This work may implicate these processes and the specific proteins involved as novel effectors of N. caninum tachyzoite virulence
Europe's Quantum Flagship is taking off
No full textThe European Quantum Flagship is a 10-year, 1 billion Euro initiative, expected to bring quantum technologies from the lab to the market. The initiative is now taking off: The implementation and governance models are decided and the first research projects are commencing their work.Quantum Internet DivisionQuantum Information and Softwar
Messy Eating
No full textLiterature on the ethics and politics of food and that on animal-human relationships have infrequently converged. Representing an initial step towards bridging this divide, Messy Eating features interviews with thirteen prominent and emerging scholars about the connections between their academic work and their approach to consuming animals as food. The collection explores how authors working across a range of perspectives—postcolonial, Indigenous, Black, queer, trans, feminist, disability, poststructuralist, posthumanist, and multispecies—weave their theoretical and political orientations with daily, intimate, and visceral practices of food consumption, preparation, and ingestion.
Contributors: Neel Ahuja, Billy Ray Belcourt, Matthew Calarco, Lauren Corman, Naisargi Dave, Maneesha Deckha, Maria Elena Garcia, Sharon Holland, Kelly Struthers Montford, H. Peter Steeves, Kim TallBear, Sunaura Taylor, Harlan Weaver, Kari Weil, Cary Wolfe
Samantha King is Professor of Gender Studies, Cultural Studies, and Kinesiology and Health Studies at Queen’s University. She is the author of Pink Ribbons, Inc. Breast Cancer and the Politics of Philanthropy.
R. Scott Carey is a grant writer with a PhD in Kinesiology and Health Studies from Queen’s University. Isabel MacQuarrie is a Juris Doctor candidate at Harvard Law School with an MA in sociology from Queen’s University.
Victoria N. Millious is a PhD candidate in the School of Kinesiology and Health Studies, Queen’s University.
Elaine M. Power is Associate Professor in the School of Kinesiology & Health Studies at Queen’s University
Crisis is governance : sub-prime, the traumatic event, and bare life
No full textThe article provides a critical analysis of the role of discourses of trauma and the traumatic event in constituting the ethico-political possibilities and limits of the subprime crisis. It charts the invocation of metaphors of a financial Tsunami and pervasive media focus on
emotional ‘responses’ like fear, anger, and blame, suggesting that such traumatic discourses
constituted the subprime crisis as a singular and catastrophic ‘event’ demanding of particular
(humanitarian) responses. We draw upon the thought of Giorgio Agamben to render this constituted logic of event and response in terms of the concomitant production of bare life; the savers and homeowners who became ‘helpless victims’ in need of rescue. We therefore
tie the ongoing production of the sovereign power of global finance to broader processes that
entail the enfolding and securing of everyday financial subjects. These arguments are illustrated via an analysis of three subjects: the economy, bankers and borrowers. We argue that it was the movement between subject positions – from safe to vulnerable, from
entrepreneurial to greedy, from victim to survivor, etc. - that marked out the effective manner
of governance, confirming in this process sovereign categories of financial citizenship, asset
based welfare, and securitisation that many would posit as the very problem. In short, (the
way that the) crisis (was constituted) is governance
