246 research outputs found

    Statistical analysis of high-speed jet flows

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    The spatiotemporal dynamics of pressure fluctuations of a turbulent jet flow is examined from the viewpoints of symbolic permutations theory and Kolmogorov-Smirnov statistics. The methods are applied to unveil hidden structures in the near-field of the two jets corresponding to the NASA SHJAR SP3 and SP7 experiments. Large Eddy Simulations (LES) are performed using the high-resolution Compact Accurately Boundary-Adjusting high-REsolution Technique (CABARET) accelerated on Graphics Processing Units (GPUs). It is demonstrated that the decomposition of the LES pressure solutions into symbolic patterns of simpler temporal structure reveals the existence of some orderly structures in the jet flows. To separate the non-linear dynamics of the revealed structures from the linear part, the results based on the pressure signals obtained from LES are compared with the surrogate dataset constructed from the original data

    Seafood fraud incidents control: Histological based methods as reliable tools for fresh and frozen/thawed products discrimination

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    Freezing is one of the commonest methods applied for seafood shelf-life extension and long-term preservation. Nevertheless, the quality decay caused by water crystallization and cellular dehydration is responsible of significant reduction of the frozen-thawed products commercial value. Therefore, according to the European Legislation on food labelling, the declaration of freezing process represents a mandatory information for the protection of consumers’ rights. In fact, the lack of such information, besides entailing a non-conformity, can favor commercial frauds. The present work aims to present the development and validation of a histological approach, based on quali-quantitative histological markers, for the discrimination between fresh and thawed-frozen fishery products. In particular, the results of the application of the histological method on Merluccius merluccius and Octopus vulgaris, respectively selected as study models for white meat fish and cephalopods species, will be presented

    Detailed design of a lattice composite fuselage structure by a mixed optimization method

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    In this paper, a procedure for designing a lattice fuselage barrel has been developed and it comprises three stages: first, topology optimization of an aircraft fuselage barrel has been performed with respect to weight and structural performance to obtain the conceptual design. The interpretation of the optimal result is given to demonstrate the development of this new lattice airframe concept for the fuselage barrel. Subsequently, parametric optimization of the lattice aircraft fuselage barrel has been carried out using Genetic Algorithms on metamodels generated with Genetic Programming from a 101-point optimal Latin hypercube design of experiments. The optimal design has been achieved in terms of weight savings subject to stability, global stiffness and strain requirements and then was verified by the fine mesh finite element simulation of the lattice fuselage barrel. Finally, a practical design of the composite skin complying with the aircraft industry lay-up rules has been presented. It is concluded that the mixed optimization method, combining topology optimization with the global metamodel-based approach, has allowed to solve the problem with sufficient accuracy as well as provided the designers with a wealth of information on the structural behaviour of the novel anisogrid composite fuselage design

    MR blockade protects against diet induced obesity, adipocyte dysfunction and cardiac inflammation in mice, through browning of the adipose organ and modulation of autophagy

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    Obesity is a key factor in the development of insulin resistance (IR), cardiovascular disease, hypertension, type 2 diabetes etc. Given the near epidemic incidence of obesity in western society there is a clear need for effective treatment options. Mineralocorticoid receptor (MR) blockade has shown significant promise in transgenic mouse models of obesity in limiting IR and adipocyte dysfunction, a disease that is independent of classical MR actions (renal). Female 10-weekold C57bl6 mice were fed with normal chow or a high fat (HF) diet for 12 weeks. Mice fed HF diet were concomitantly treated for 12 weeks with drospirenone (DRSP, 6 mg/kg/day), a potent MR antagonist with antiadipogenic activity, or spironolactone (SPIRO, 20 mg/kg/day). Mice fed HF diet showed a significant increase in total body weight, fat mass, mean adipocyte size, expression of white adipose tissue (WAT) marker genes and showed impaired glucose tolerance after intraperitoneal plasma glucose tolerance test. DRSP and SPIRO prevented weight gain and white fat mass expansion induced by HF diet in parametrial, perivescical, and inguinal depots without affecting interscapular fat pad weight. Magnetic Resonance Imaging (MRI) confirmed that MR antagonists blocked the HF dietdriven expansion of abdomino-pelvic (parametrial and perivescical) fat volume. High levels of MR mRNA were detected in all depots of adipose tissue. HF fed mice showed no increase in heart or kidney weight and tissue fibrosis. Cardiac macrophage recruitment and osteopontin staining was increased in hearts of HF fed mice and reversed by both MR antagonists. Moreover, both DRSP and SPIRO prevented the impaired glucose tolerance in mice fed HF diet, and countered HF diet-induced up-regulation of WAT markers transcripts and adipocyte hypertrophy. Importantly, MR antagonists increased uncoupling protein 1 (UCP-1) positive brown-like adipocyte content in WAT, and improved metabolic activity of adipose tissue, as indicated by PET/CT imaging. In keeping with this, MR antagonism significantly increased expression of brown-like adipocyte marker genes such PRDM16, CIDEA, beta-3 adrenergic receptor (ADRB3) and UCP-1 in all WAT depots analysed. In exploring the mechanism, we demonstrated that MR antagonism induced brown adipose tissue (BAT) markers, and reduced the autophagic rate, a key remodelling process in adipocyte differentiation, in WAT depots in vivo as well as in primary cultured adipocytes. We conclude that adipocyte MR regulates BAT-like remodeling of WAT through modulation of autophagy. MR blockade therefore has promise as a novel therapeutic option for the prevention of metabolic dysfunctions and the cardiac consequences of obesity. doi:10.1016/j.ijcme.2015.05.012 Transcriptional control of ICAM-1 in human coronary artery endothelial cells by Mineralocorticoid Receptor (MR): Implications for the protective effects of MR antagonists in cardiovascular diseases V. Marzolla, A. Armani, A. Fabbri, I.Z. Jaffe, M. Caprio Laboratory of Cardiovascular Endocrinology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Pisana, Rome, Italy Department of Medicina dei Sistemi, Endocrinology Unit, S. Eugenio & CTO A. Alesini Hospitals, University Tor Vergata, Rome, Italy Molecular Cardiology Research Institute, Tufts Medical Center, Boston

    Spectrometer Scan Mechanism for Encountering Jovian Orbit Trojan Asteroids

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    This paper describes the design, testing, and lessons learned during the development of the Lucy Ralph (L'Ralph) Scan Mirror System (SMS), composed of the Scan Mirror Mechanism (SMM), Differential Position Sensor System (DPSS) and Mechanism Control Electronics (MCE). The L'Ralph SMS evolved from the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM), so design comparisons will be made. Lucy is scheduled to launch in October 2021, embarking upon a 12-year mission to make close range encounters in 2025 and 2033 with seven Trojan asteroids and one main belt asteroid that are within the Jovian orbit. The L'Ralph instrument is based upon the New Horizons Ralph instrument, which is a panchromatic and color visible imager and infrared spectroscopic mapper that slewed the spacecraft for imaging. The L'Ralph SMM is to provide scanning for imaging to eliminate the need to slew the spacecraft. One purpose of this paper is to gain understanding of the reasoning behind some of the design features as compared with the ATLAS BSM. We will identify similarities and differences between the ATLAS BSM and the L'Ralph SMM that resulted from the latter's unique requirements. Another purpose of this paper is to focus upon "Lessons Learned" that came about during the development of the L'Ralph SMM and its MCE, both mechanism engineering issues and solutions as well as Ground Support Equipment (GSE) issues and solutions that came about during the validation of requirements process. At the time of this writing, the L'Ralph SMM has been flight qualified and delivered to the project

    Application of Genetic Programming and Artificial Neural Network Approaches for Reconstruction of Turbulent Jet Flow Fields

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    Two Machine Learning (ML) methods are considered for reconstruction of turbulet signals corresponding to the Large Eddy Simulation database obtained by application of the high-resolution CABARET method accelerated on GPU cards for flow solutions of NASA Small Hot Jet Acoustic Rig (SHJAR) jets. The first method is the Feedforward Neural Networks technique, which was successfully implemented for a turbulent flow over a plunging aerofoil in (Lui and Wolf, 2019). The second method is based on the application of Genetic Programming, which is well-known in optimisation research, but has not been applied for turbulent flow reconstruction before. The reconstruction of local flow velocity and pressure signals as well as timedependent principle coefficients of the Spectral Proper Orthogonal Decomposition of turbulent pressure fluctuations are considered. Stability and dependency of the ML algorithms on the smoothness property and the sampling rate of the underlying turbulent flow signals are discussed

    Selection of Histological Parameters for the Development of an Analytical Method for Discriminating Fresh and Frozen/Thawed Common Octopus (Octopus vulgaris) and Preventing Frauds along the Seafood Chain

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    This study aimed at selecting effective histological indicators of the freezing process, for the discrimination of fresh and frozen common octopus Octopus vulgaris. Histological indices of freezing process were selected in mantle and arm muscle and axial nerve tissues. Seven histological parameters were chosen: overall muscle tissue structural organization (a); gaping among muscle bundles (b); presence of optically empty spaces between and within muscle bundles (c); white spaces percentage between and within muscle bundles (d); overall nerve structural organization (e); presence of linear fissures and/or empty spaces within neuropil and axonal tract (f); presence of empty spaces within connective tissue matrix surrounding the nerve (g); empty space percentage within arm axial nerve region (h). The parameters were assessed on 150 mantle muscle sections (a, b, c, d), 150 arm muscle (b, c) and nervous (e, f, g, h) tissue sections belonging to 20 fresh exemplars further subdued to conventional freezing procedure at − 20 Â°C, 25 fresh curled exemplars, 25 exemplars industrially frozen at − 80 Â°C, and 20 thawed, curled, and individually quick frozen exemplars. Overall structural organization (a, e), gaping (b), and presence of optically empty spaces (c, f) confirmed significant morphological freezing indices in mantle and arm sections. In mantle, two d values (d < 25% and 25% < d < 33%) were proposed as complementary thresholds to be applied in association with b and c indices for freezing discrimination. These parameters appear eligible to set a method for discriminating fresh/thawed octopus products to be applied both in official control and self-check activities

    Essential role of ICAM-1 in aldosterone-induced atherosclerosis.

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    OBJECTIVE: Elevated aldosterone is associated with increased risk of atherosclerosis complications, whereas treatment with mineralocorticoid receptor (MR) antagonists decreases the rate of cardiovascular events. Here we test the hypothesis that aldosterone promotes early atherosclerosis by modulating intercellular adhesion molecule-1 (ICAM-1) expression and investigate the molecular mechanisms by which aldosterone regulates ICAM-1 expression. METHODS AND RESULTS: Apolipoprotein-E (ApoE)-/- mice fed an atherogenic diet and treated with aldosterone for 4weeks showed increased vascular expression of ICAM-1, paralleled by enhanced atherosclerotic plaque size in the aortic root. Moreover, aldosterone treatment resulted in increased plaque lipid and inflammatory cell content, consistent with an unstable plaque phenotype. ApoE/ICAM-1 double knockout (ApoE-/-/ICAM-1-/-) littermates were protected from the aldosterone-induced increase in plaque size, lipid content and macrophage infiltration. Since aldosterone is known to regulate ICAM-1 transcription via MR in human endothelial cells, we explored MR regulation of the ICAM-1 promoter. Luciferase reporter assays performed in HUVECs using deletion constructs of the human ICAM-1 gene promoter showed that a region containing a predicted MR-responsive element (MRE) is required for MR-dependent transcriptional regulation of ICAM-1. CONCLUSIONS: Pro-atherogenic effects of aldosterone are mediated by increased ICAM-1 expression, through transcriptional regulation by endothelial MR. These data enhance our understanding of the molecular mechanism by which MR activation promotes atherosclerosis complications

    Cavity QED with Diamond Nanocrystals and Silica Microspheres

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    Normal mode splitting is observed in a cavity QED system, in which nitrogen vacancy centers in diamond nanocrystals are coupled to whispering gallery modes in a silica microsphere. The composite nanocrystal-microsphere system takes advantage of the exceptional spin properties of nitrogen vacancy centers as well as the ultra high quality factor of silica microspheres. The observation of the normal mode splitting indicates that the dipole optical interaction between the relevant nitrogen vacancy center and whispering gallery mode has reached the strong coupling regime of cavity QED
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