576 research outputs found

    Telomeres in interstitial lung diseases

    Get PDF
    Interstitial lung diseases (ILD) encompass a group of conditions involving fibrosis and/or inflammation of the pulmonary parenchyma. Telomeres are repetitive DNA sequences at chromosome ends which protect against genome instability. At each cell division, telomeres shorten, but the telomerase complex partially counteracts progressive loss of telomeres by catalysing the synthesis of telomeric repeats. Once critical telomere shortening is reached, cell cycle arrest or apoptosis are triggered. Telomeres progressively shorten with age. A number of rare genetic mutations have been identified in genes encoding for components of the telomerase complex, including telomerase reverse transcriptase (TERT) and telomerase RNA component (TERC), in familial and, less frequently, in sporadic fibrotic ILDs. Defects in telomerase result in extremely short telomeres. More rapidly progressive disease is observed in fibrotic ILD patients with telomere gene mutations, regardless of underlying diagnosis. Associations with common single nucleotide polymorphisms in telomere related genes have also been demonstrated for various ILDs. Shorter peripheral blood telomere lengths compared to age-matched healthy individuals are found in a proportion of patients with fibrotic ILDs, and in idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (HP) have been linked to worse survival, independently of disease severity. Greater susceptibility to immunosuppressant-induced side effects in patients with short telomeres has been described in patients with IPF and with fibrotic HP. Here, we discuss recent evidence for the involvement of telomere length and genetic variations in the development, progression, and treatment of fibrotic ILDs

    Through-barrier electromagnetic imaging with an atomic magnetometer

    Get PDF
    We demonstrate the penetration of thick metallic and ferromagnetic barriers for imaging of conductive targets underneath. Our system is based on an 85Rb radio-frequency atomic magnetometer operating in electromagnetic induction imaging modality in an unshielded environment. Detrimental effects, including unpredictable magnetic signatures from ferromag- netic screens and variations in the magnetic background, are automatically compensated by active compensation coils controlled by servo loops. We exploit the tunability and low-frequency sensitivity of the atomic magnetometer to directly image multiple conductive targets concealed by a 2.5 mm ferromagnetic steel shield and/or a 2.0 mm aluminium shield, in a single scan. The performance of the atomic magnetometer allows imaging without any prior knowledge of the barriers or the targets, and without the need of background subtraction. A dedicated edge detection algorithm allows automatic estimation of the targets’ size within 3.3 mm and of their position within 2.4 mm. Our results prove the feasibility of a compact, sensitive and automated sensing platform for imaging of concealed objects in a range of applications, from security screening to search and rescue

    Interaction-induced current-reversals in driven lattices

    Full text link
    We demonstrate that long-range interactions can cause, as time evolves, consecutive reversals of directed currents for dilute ensembles of particles in driven lattices. These current-reversals are based on a general mechanism which leads to an interaction-induced accumulation of particles in the regular regions of the underlying single-particle phase space and to a synchronized single-particle motion as well as an enhanced efficiency of Hamiltonian ratchets.Comment: 5 pages, 5 figure

    Vibrational mechanics in an optical lattice: controlling transport via potential renormalization

    Get PDF
    We demonstrate theoretically and experimentally the phenomenon of vibrational resonance in a periodic potential, using cold atoms in an optical lattice as a model system. A high-frequency (HF) drive, with frequency much larger than any characteristic frequency of the system, is applied by phase-modulating one of the lattice beams. We show that the HF drive leads to the renormalization of the potential. We used transport measurements as a probe of the potential renormalization. The very same experiments also demonstrate that transport can be controlled by the HF drive via potential renormalization.Comment: Phys. Rev. Lett., in pres

    Les Espaces d’apprentissage : une question urbaine et territoriale | Learning Spaces: an Urban and Territorial Issue

    Get PDF
    Les Ă©quipements et amĂ©nagements publics ont Ă©tĂ© rĂ©alisĂ©s en grande partie au cours du siĂšcle dernier, pendant l’ñge d’or des politiques de l’État-providence en Europe. Ils ont contribuĂ© Ă  structurer les espaces ordinaires dans des contextes urbains et mĂ©tropolitains, Ă  la faveur d’opĂ©rations d’extension urbaine et d’interventions diffuses au sein de petites villes ou dans des zones rurales. Ces infrastructures matĂ©rielles du quotidien sont organisĂ©es autour des Ă©coles, des Ă©quipements sportifs, des centres civiques, des bibliothĂšques, de terrains de jeux : des espaces bĂątis et non bĂątis, principalement publics, dont la valeur d’usage est Ă©troitement liĂ©e aux principes de l’égalitĂ© sociale et de la citoyennetĂ©. Le recueil des articles qui composent le dossier thĂ©matique permet d’éclairer des cas d’études qui soulignent ces potentialitĂ©s et confirment l’importance des Ă©coles dans les processus de transformation urbaine, au-delĂ  de l’urgence pandĂ©mique

    Magnetic Induction Imaging with Optical Atomic Magnetometers: Towards Applications to Screening and Surveillance

    Get PDF
    We propose a new approach, based on optical atomic magnetometers and magnetic induction tomography (MIT), for remote and non-invasive detection of conductive targets. Atomic magnetometers overcome the main limitations of conventional MIT instrumentation, in particular their poor low-frequency sensitivity, their large size and their limited scalability. Moreover, atomic magnetometers have been proven to reach extremely high sensitivities, with an improvement of up to 7 orders of magnitude in the 50 MHz to DC band, with respect to a standard pick-up coil of the same size. In the present scheme, an oscillating magnetic field induces eddy currents in a conductive target and laser-pumped atomic magnetometers, either stand-alone or in an array, detect the response of the objects. A phase-sensitive detection scheme rejects the background, allowing remote detection of the secondary field and, thus, mapping of objects, hidden in cargos, underwater or underground. The potential for extreme sensitivity, miniaturization, dynamic range and array operation paves the way to a new generation of non-invasive, active detectors for surveillance, as well as for real-time cargo screening. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    Machine Learning Based Localization and Classification with Atomic Magnetometers

    Get PDF
    We demonstrate identification of position, material, orientation, and shape of objects imaged by a ⁞⁔Rb atomic magnetometer performing electromagnetic induction imaging supported by machine learning. Machine learning maximizes the information extracted from the images created by the magnetometer, demonstrating the use of hidden data. Localization 2.6 times better than the spatial resolution of the imaging system and successful classification up to 97% are obtained. This circumvents the need of solving the inverse problem and demonstrates the extension of machine learning to diffusive systems, such as low-frequency electrodynamics in media. Automated collection of task-relevant information from quantum-based electromagnetic imaging will have a relevant impact from biomedicine to security

    Stochastic resonance in periodic potentials: realization in a dissipative optical lattice

    Full text link
    We have observed the phenomenon of stochastic resonance on the Brillouin propagation modes of a dissipative optical lattice. Such a mode has been excited by applying a moving potential modulation with phase velocity equal to the velocity of the mode. Its amplitude has been characterized by the center-of-mass (CM) velocity of the atomic cloud. At Brillouin resonance, we studied the CM-velocity as a function of the optical pumping rate at a given depth of the potential wells. We have observed a resonant dependence of the CM velocity on the optical pumping rate, corresponding to the noise strength. This corresponds to the experimental observation of stochastic resonance in a periodic potential in the low-damping regime

    Severe Idiopathic Eosinophilic Pneumonia and Vasculitis in 11 Horses

    Get PDF
    Introduction: Various eosinophilic lesions have been described in horses. Multisystemic eosinophilic epitheliotropic disease (MEED) characterized by eosinophilic granulomas in various organs represents the most diffuse manifestation. In the present study we describe the gross and microscopical lesions of idiopathic eosinophilic pneumonia and vasculitis in 11 horses without systemic involvement. Materials and Methods: During a 2-year period (2010–2011), lungs from 88 horses with gross signs of pulmonary disease were collected at a slaughterhouse. Lung sections were stained with haematoxylin and eosin, Giemsa and periodic acid–Schiff. Results: In 11 horses, lungs were enlarged, pale pink and collapsed, with multifocal to coalescing, white–red, 0.4–4.0 cm diameter nodules distributed throughout the parenchyma. Histologically, the lesions ranged from severe eosinophilic bronchointerstitial pneumonia to severe eosinophilic lobular bronchopneumonia associated with eosinophilic necrotizing vasculitis affecting small to medium sized vessels. Mild interstitial fibrosis was also present. The other part of the parenchyma appeared emphysematous. There was no histological evidence of parasites within these lesions. Conclusions: Eosinophilic pneumonia and vasculitis without intralesional parasites are rarely described in horses. Histological findings do not resemble the typical eosinophilic granulomas observed in lungs of horses with MEED, but are similar to the findings in idiopathic chronic eosinophilic pneumonia of man and of Churg–Strauss syndrome of man
    • 

    corecore