Amélioration des performances d'un avon régional par l'utilisation de riblets et de la technologie NLF

International audienceThe application of riblets on a typical regional turboprop configuration is discussed in this paper. The effect of the riblets is modeled as a singular roughness problem by a proper boundary condition at the wall. The model, already proposed in a previous paper, is briefly described. The drag prediction capabilities are verified by showing some airfoil flow applications. Then a typical wing-body of a regional aircraft is considered. The configuration has been designed to have extended natural laminar flow in cruise conditions. Riblets are applied at flow specifications representative of cruise in combination with the natural laminar flow technology and in climb/descent conditions. A comparison of the two technologies in terms of drag reduction is presented. Their combined application can result in a cruise drag reduction of more than 20%. The resulting fuel savings during a typical operational day are evaluated

Leptin Enhances, via AP-1, Expression of Aromatase in the MCF-7 Cell Line *

Leptin, a product of adipocytes, is involved in the regulation of body weight and results strongly correlated to body fat content. An excess of fat mass represents a breast cancer risk factor particularly in postmenopausal women, where estrogen production by adipose tissue through its own aromatase activity stimulates tumor progression. Leptin stimulates estrogen production through the increase of aromatase expression and activity in human luteinized granulosa cells and adipose stromal cells. In the present study, we have examined the possible link that exists between leptin and breast cancer, focusing our attention on the direct effect of leptin on aromatase activity, which may enhance estrogen production and induce tumor cell growth stimulation. We have shown that leptin enhances aromatase mRNA expression, aromatase content, and its enzymatic activity in MCF-7. Aromatase expression appears to be regulated by tissue-specific promoter. It has been demonstrated that promoters II and 1.3 are the major promoters that drive aromatase expression in MCF-7. Transient transfection experiments using vector containing human aromatase promoters II and 1.3 sequence fused with luciferase reporter gene demonstrated that leptin is able to activate this promoter. In the presence of either mitogen-activated protein kinase inhibitor PD 98059 or ERK2 dominant negative as well as in the presence of STAT3 dominant negative, the stimulatory effects of leptin on aromatase promoter, enzymatic activity, and aromatase protein content were inhibited. Functional studies of mutagenesis and electrophoretic mobility shift assay revealed that the AP-1 motif is important in determining the up-regulatory effects induced by leptin on aromatase expression in MCF-7

Cat Taming in the Western Mediterranean. Issues, Problematics and Unpredictability in the Light of Bio-archaeological Approaches to a Museum Specimen

The vast wealth of cultural artifacts and ancient biological samples can today be investigated using a great variety of methods and technologies. The result is a growing diffusion of studies on DNA, isotopes and morphometrics, and the exponential growth of publications and bio-archaeological discoveries of inestimable value for different areas of interpretation, such as phylogeny, history and archaeology. This paper describes the morphological and molecular study of a rare specimen of Felis from an Early Bronze Age horizon. The report offers the opportunity for a brief discussion on cat taming, on the origin of this practice and on the archaeological importance of this specimen for the reconstruction of taming practices in the Western Mediterranean Basin.Il vasto patrimonio culturale di manufatti e di reperti biologici antichi può attualmente essere investigato con molte metodologie e tecnologie. Ne deriva una crescente diffusione di studi sul DNA, isotopici e morfogeometrici e una crescita esponenziale delle pubblicazioni e dei risultati bio-archeologici di inestimabile valore per ambiti interpretativi diversi, filogenetici, storici, archeologici. Il presente lavoro descrive uno studio morfologico e molecolare di un raro reperto di Felis proveniente da un orizzonte del Bronzo Antico. Il report offre per altro l’occasione per una breve disamina sull’addomesticamento del gatto, la provenienza di tale pratica e sull’importanza zooarcheologica della relazione con Homo nel Mediterraneo occidentale

Interleukin-15 alters hippocampal synaptic transmission and impairs episodic memory formation in mice

Cytokines are potent immunomodulators exerting pleiotropic effects in the central nervous system (CNS). They influence neuronal functions and circuit activities with effects on memory processes and behaviors. Here, we unravel a neuromodulatory activity of interleukin-15 (IL-15) in mouse brain. Acute exposure of hippocampal slices to IL-15 enhances gamma-aminobutyricacid (GABA) release and reduces glutamatergic currents, while chronic treatment with IL-15 increases the frequency of hippocampal miniature inhibitory synaptic transmission and impairs memory formation in the novel object recognition (NOR) test. Moreover, we describe that serotonin is involved in mediating the hippocampal effects of IL-15, because a selective 5-HT3A receptor antagonist prevents the effects on inhibitory neurotransmission and ameliorates mice performance in the NOR test. These findings provide new insights into the modulatory activities of cytokines in the CNS, with implications on behavior

Adult IDH wild-type glioblastoma ultrastructural investigation suggests a possible correlation between morphological biomarkers and Ki-67 index

Glioblastoma is an aggressive brain tumor with an average life expectancy between 14 and 16 months after diagnosis. The Ki-67 labeling index (LI), a measure of cellular proliferation, is emerging as a prognostic marker in GBM. In this study, we investigated the ultrastructure of glioblastoma tissue from 9 patients with the same molecular profile (adult IDH wild-type glioblastoma, wild-type ATRX, and positive for TP53 expression, GFAP expression, and EGFR overexpression) to find possible ultrastructural features to be used as biomarkers and correlated with the only parameter that differs among our samples, the Ki-67 LI. Our main results were the visualization of the anatomical basis of astrocyte-endothelial cells crosstalk; the ultrastructural in situ imaging of clusters of hyperactivated microglia cells (MsEVs); the ultrastructural in situ imaging of microglia cells storing lipid vesicles (MsLVs); the ultrastructural in situ imaging of neoplastic cells mitophagy (NCsM). The statistical analysis of our data indicated that MsEVs and MsLVs correlate with the Ki-67 LI value. We can thus assume they are good candidates to be considered morphological biomarkers correlating to Ki-67 LI. The role of NCsM instead must be further evaluated. Our study findings demonstrate that by combining ultrastructural characteristics with molecular information, we can discover biomarkers that have the potential to enhance diagnostic precision, aid in treatment decision-making, identify targets for therapy, and enable personalized treatment plans tailored to each patient. However, further research with larger sample sizes is needed to validate these findings and fully utilize the potential of ultrastructural analysis in managing glioblastoma

Adipocyte-derived extracellular vesicles promote breast cancer cell malignancy through HIF-1α activity.

Abstract Extracellular vesicles (EVs) are emerging key protagonists in intercellular communication between adipocytes and breast cancer (BC) cells. Here, we described a new mechanism by which EVs released by mature adipocytes promoted breast cancer cell malignancy "in vitro" and "in vivo". We found that adipocyte-derived EVs enhanced growth, motility and invasion, stem cell-like properties, as well as specific traits of epithelial-to-mesenchymal transition in both estrogen receptor positive and triple negative BC cells. Of note, adipocyte-derived EVs aid breast tumor cells in lung metastatic colonization after tail-vein injection in mice. These EV-mediated effects occur via the induction of HIF-1α activity, since they were abrogated by the use of the HIF-1α inhibitor KC7F2 or in cells silenced for HIF-1α expression. Moreover, using an "ex vivo" model of obese adipocytes we found that the depletion of EVs counteracted the ability of obese adipocytes to sustain pro-invasive phenotype in BC cells. Interestingly, EVs released by undifferentiated adipocytes failed to induce aggressiveness and HIF-1α expression. These findings shed new light on the role of adipocyte-derived EVs in breast cancer progression, suggesting the possibility to target HIF-1α activity to block the harmful adipocyte-tumor cell dialogue, especially in obese settings

Coronary computed tomography angiography in acute chest pain: a sustainable model with remote support

Purpose: To propose a sustainable model of coronary computed tomography angiography (CCTA) use in acute coronary syndrome (ACS) in emergency department (ED) using a partially based teleradiology reporting model. We also analyzed impact of the protocol on short- and long-term patient's outcome. Methods: During a 12-month period, 104 consecutive patients admitted to the ED for acute chest pain (ACP) with low-to-intermediate risk of ACS were selected and underwent CCTA. Medical reporting was based on a model combining on-site physician and a remote radiologist supported by a web client-based teleradiology system, covering a 24/7 service. CCTA findings were correlated with the incidence of major adverse cardiovascular events (MACEs) over a 5-year follow-up. Results: CCTA ruled-out CAD in 76 patients (73.1%). Moderate (7.7%) to severe (19.2%) CAD was identified in 28 patients who were directly referred to functional tests or invasive angiography. The mean discharge time was 10.8 ± 5.8 h; patients with absent to mild disease were safely and quickly discharged. Remote reporting using a teleradiology platform was performed in 82/104 cases (78.9%), with slight impact on patient's discharge time (10.4 ± 5.6 vs. 12.1 ± 6.1 h, p: 0.24). MACEs at 6-month and at 5-year follow-up were 0.96% (n = 1/104) and 15.5% (n = 14/90). Conclusion: CCTA assessment of patients with ACP enables to quickly rule-out ACS, avoiding waste of time and resources, to identify patients with obstructive CAD which should be referred to subsequent tests and to stratify the risk of MACEs at short and long time. A partial teleradiology based 24/7 CCTA service is feasible and sustainable, even in small ED

Comparability of Hot-Wire Estimates of Liquid Water Content in SLD Conditions

Future compliance to FAA 14 CFR Part 25 and EASA CS-25 Appendix O conditions has required icing wind tunnels to expand their cloud simulation envelope, and demonstrate accurate calibration of liquid water content and droplet particle size distributions under these conditions. This has led to a renewed community interest in the accuracy of these calibrations, and the potential inter-facility bias due to the choice of instrumentation and processing methods. This article provides a comparison of the response of various hot-wire liquid water content instruments under Appendix C and supercooled large droplet conditions, after an independent similar analysis at other wind tunnel facilities. The instruments are being used, or are under consideration for use, by facilities collaborating in the ICE GENESIS program. For droplet median volume diameters (MVDs) between about 15 and 250 micrometer, cylindrical hot wire LWC sensors were found to consistently and increasingly under-read measurements from conical and trough TWC sensors as MVD increased, and were not considered further. Of the remaining TWC sensors, the specific instruments investigated were found to agree within about 20% of their average test point response for the range of conditions tested, but systematic scale differences between instruments were found to reach about a factor of 1.4. Sensitivity to increasing droplet MVD was concluded to be similar amongst different instruments given the uncertainties, except for two that exhibited notable roll-off with MVD relative to the others