A simple beam combination for stellar interferometry

In stellar interferometry, image quality improves significantly with the inclusion of more telescopes and the use of phase closure. We demonstrate, using first coherent and then partially coherent white light, a compact and efficient pair-wise combination of twelve or more beams. The input beams are lined up and spread through a cylindrical lens into a comb of parallel ellipses, which interferes with a perpendicular copy of itself to form a matrix of interferograms between all pairs. The diagonal elements show interference of each beam with itself, for in-tensity calibration. The measured white-light visibilities were high and stable

Observation of Macroscopic Structural Fluctuations in bcc Solid 4He

We report neutron diffraction studies of low density bcc and hcp solid 4He. In the bcc phase, we observed a continuous dynamical behaviour involving macroscopic structural changes of the solid. The dynamical behaviour takes place in a cell full of solid, and therefore represents a solidsolid transformation. The structural changes are consistent with a gradual rotation of macroscopic grains separated by low angle grain boundaries. We suggest that these changes are triggered by random momentary vibrations of the experimental system. An analysis of Laue diffraction patterns indicates that in some cases these structural changes, once initiated by a momentary impulse, seem to proceed at a constant rate over times approaching an hour. The energy associated with these macroscopic changes appears to be on the order of kT. Under similar conditions (temperature and pressure), these effects were absent in the hcp phase.Comment: 14 pages, 6 figure, accepted for PR

Eliminating Anchor Loss In Optomechanical Resonators Using Elastic Wave Interference

Optomechanical resonators suffer from the dissipation of mechanical energy through the necessary anchors enabling the suspension of the structure. Here, we show that such structural loss in an optomechanical oscillator can be almost completely eliminated through the destructive interference of elastic waves using dual-disk structures. We also present both analytical and numerical models that predict the observed interference of elastic waves. Our experimental data reveal unstressed silicon nitride (Si3N4) devices with mechanical Q-factors up to 104 at mechanical frequencies of f=102 MHz (fQ=1012) at room temperature. © 2014 AIP Publishing LLC.1055DARPA; Defense Advanced Research Projects Agency; NSF; Defense Advanced Research Projects AgencyGavartin, E., Verlot, P., Kippenberg, T.J., (2012) Nat. Nanotechnol., 7, p. 509. , 10.1038/nnano.2012.97Chan, J., Alegre, T.P.M., Safavi-Naeini, A.H., Hill, J.T., Krause, A., Groeblacher, S., Aspelmeyer, M., Painter, O.J., (2011) Nature, 478, p. 89. , 10.1038/nature10461Verhagen, E., Deleglise, S., Weis, S., Schliesser, A., Kippenberg, T.J., (2012) Nature, 482, p. 63. , 10.1038/nature10787Marquardt, F., Harris, J., Girvin, S., (2006) Phys. Rev. Lett., 96, p. 103901. , 10.1103/PhysRevLett.96.103901Poot, M., Fong, K.Y., Bagheri, M., Pernice, W., Tang, H.X., (2012) Phys. Rev. A, 86, p. 053826. , 10.1103/PhysRevA.86.053826Zhang, M., Wiederhecker, G., Manipatruni, S., Barnard, A., McEuen, P., Lipson, M., (2012) Phys. Rev. Lett., 109, p. 233906. , 10.1103/PhysRevLett.109.233906Tallur, S., Bhave, S.A., (2013) Nano Lett., 13, p. 2760. , 10.1021/nl400980uEkinci, K.L., Roukes, M.L., Nanoelectromechanical systems (2005) Review of Scientific Instruments, 76 (6), pp. 1-12. , DOI 10.1063/1.1927327, 061101Vahala, K.J., (2008) Phys. Rev. A, 78, p. 023832. , 10.1103/PhysRevA.78.023832Photiadis, D.M., Judge, J.A., (2004) Appl. Phys. Lett., 85, p. 482. , 10.1063/1.1773928Lifshitz, R., Phonon-mediated dissipation in micro- and nano-mechanical systems (2002) Physica B: Condensed Matter, 316-317, pp. 397-399. , DOI 10.1016/S0921-4526(02)00524-0, PII S0921452602005240Cole, G.D., Wilson-Rae, I., Werbach, K., Vanner, M.R., Aspelmeyer, M., (2011) Nat. Commun., 2, p. 231. , 10.1038/ncomms1212Lifshitz, R., Roukes, M., (2000) Phys. Rev. B, 61, p. 5600. , 10.1103/PhysRevB.61.5600Arcizet, O., Rivière, R., Schliesser, A., Anetsberger, G., Kippenberg, T.J., (2009) Phys. Rev. A, 80, p. 021803. , 10.1103/PhysRevA.80.021803Anetsberger, G., Rivière, R., Schliesser, A., Arcizet, O., Kippenberg, T.J., (2008) Nat. Photonics, 2, p. 627. , 10.1038/nphoton.2008.199Hsu, F.-C., Hsu, J.-C., Huang, T.-C., Wang, C.-H., Chang, P., (2011) J. Phys. D: Appl. Phys., 44, p. 375101. , 10.1088/0022-3727/44/37/375101Eichenfield, M., Chan, J., Camacho, R.M., Vahala, K.J., Painter, O.J., (2009) Nature, 462, p. 78. , 10.1038/nature08524Verbridge, S.S., Parpia, J.M., Reichenbach, R.B., Bellan, L.M., Craighead, H.G., High quality factor resonance at room temperature with nanostrings under high tensile stress (2006) Journal of Applied Physics, 99 (12), p. 124304. , DOI 10.1063/1.2204829Wiederhecker, G.S., Chen, L., Gondarenko, A., Lipson, M., (2009) Nature, 462, p. 633. , 10.1038/nature08584Rosenberg, J., Lin, Q., Painter, O.J., (2009) Nat. Photonics, 3, p. 478. , 10.1038/nphoton.2009.137Kippenberg, T.J., Vahala, K.J., (2008) Science, 321, p. 1172. , 10.1126/science.1156032Sun, Y., Tohmyoh, H., (2009) J. Sound Vib., 319, p. 392. , 10.1016/j.jsv.2008.06.017Sun, Y., Saka, M., (2010) J. Sound Vib., 329, p. 328. , 10.1016/j.jsv.2009.09.014Yasumura, K.Y., Stowe, T.D., Chow, E.M., Pfafman, T., Kenny, T.W., Stipe, B.C., Rugar, D., Quality factors in micron- and submicron-thick cantilevers (2000) Journal of Microelectromechanical Systems, 9 (1), pp. 117-125. , DOI 10.1109/84.82578

Connective Tissue Growth Factor Promotes Fibrosis Downstream of TGFΒ and IL-6 in Chronic Cardiac Allograft Rejection

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72574/1/j.1600-6143.2009.02826.x.pd

Broadband enhancement of thermal radiation

CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOBroadband thermal radiation sources are critical for various applications including spectroscopy and electricity generation. However, due to the difficulty in simultaneously achieving high absorptivity and low thermal mass these sources are inefficient. We show a platform that enables one to obtain enhanced emission by coupling a thermal emitter to an optical cavity. We experimentally demonstrate broadband enhancement of thermal emission between lambda similar to 2 - 4.2 mu m using an inherently poor thermal emitter consisting of tens of nanometers thick SiC film with 10% emissivity (epsilon(S)(iC) similar to 0.1). We measure over twofold enhancement of total emission power over the entire spectral band and threefold enhancement of thermal emission over 3 to 3.4 mu m. Our platform has the potential to enable development of ideal blackbody sources operating at substantially lower heating powers.2712A818A828CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOSem informaçãoSem informaçãoARPA-E IDEAS program (# DE-AR0000731), support from Brazilian agencies CAPES and FAPESP. Device fabrication & thin-film characterization at Cornell Nano-Scale Facility (NSF, # NNCI-1542081) and Cornell Center for Materials Research (NSF MRSEC, # DMR-1719875)

Perfect imaging: they don't do it with mirrors

Imaging with a spherical mirror in empty space is compared with the case when the mirror is filled with the medium of Maxwell's fish eye. Exact time-dependent solutions of Maxwell's equations show that perfect imaging is not achievable with an electrical ideal mirror on its own, but with Maxwell's fish eye in the regime when it implements a curved geometry for full electromagnetic waves

Effective Soft-Core Potentials and Mesoscopic Simulations of Binary Polymer Mixtures

Mesoscopic molecular dynamics simulations are used to determine the large scale structure of several binary polymer mixtures of various chemical architecture, concentration, and thermodynamic conditions. By implementing an analytical formalism, which is based on the solution to the Ornstein-Zernike equation, each polymer chain is mapped onto the level of a single soft colloid. From the appropriate closure relation, the effective, soft-core potential between coarse-grained units is obtained and used as input to our mesoscale simulations. The potential derived in this manner is analytical and explicitly parameter dependent, making it general and transferable to numerous systems of interest. From computer simulations performed under various thermodynamic conditions the structure of the polymer mixture, through pair correlation functions, is determined over the entire miscible region of the phase diagram. In the athermal regime mesoscale simulations exhibit quantitative agreement with united atom simulations. Furthermore, they also provide information at larger scales than can be attained by united atom simulations and in the thermal regime approaching the phase transition.Comment: 19 pages, 11 figures, 3 table

Coriolis Effect in Optics: Unified Geometric Phase and Spin-Hall Effect

We examine the spin-orbit coupling effects that appear when a wave carrying intrinsic angular momentum interacts with a medium. The Berry phase is shown to be a manifestation of the Coriolis effect in a non-inertial reference frame attached to the wave. In the most general case, when both the direction of propagation and the state of the wave are varied, the phase is given by a simple expression that unifies the spin redirection Berry phase and the Pancharatnam--Berry phase. The theory is supported by the experiment demonstrating the spin-orbit coupling of electromagnetic waves via a surface plasmon nano-structure. The measurements verify the unified geometric phase, demonstrated by the observed polarization-dependent shift (spin-Hall effect) of the waves.Comment: 4 pages, 3 figure

Morphological communication: exploiting coupled dynamics in a complex mechanical structure to achieve locomotion

Traditional engineering approaches strive to avoid, or actively suppress, nonlinear dynamic coupling among components. Biological systems, in contrast, are often rife with these dynamics. Could there be, in some cases, a benefit to high degrees of dynamical coupling? Here we present a distributed robotic control scheme inspired by the biological phenomenon of tensegrity-based mechanotransduction. This emergence of morphology-as-information-conduit or ‘morphological communication’, enabled by time-sensitive spiking neural networks, presents a new paradigm for the decentralized control of large, coupled, modular systems. These results significantly bolster, both in magnitude and in form, the idea of morphological computation in robotic control. Furthermore, they lend further credence to ideas of embodied anatomical computation in biological systems, on scales ranging from cellular structures up to the tendinous networks of the human hand

Single-inhaler triple therapy fluticasone furoate/umeclidinium/vilanterol versus fluticasone furoate/vilanterol and umeclidinium/vilanterol in patients with COPD: results on cardiovascular safety from the IMPACT trial

BACKGROUND: This analysis of the IMPACT study assessed the cardiovascular (CV) safety of single-inhaler triple therapy with fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) versus FF/VI and UMEC/VI dual therapy. METHODS: IMPACT was a 52-week, randomized, double-blind, multicenter Phase III study comparing the efficacy and safety of FF/UMEC/VI 100/62.5/25 mcg with FF/VI 100/25 mcg or UMEC/VI 62.5/25 mcg in patients ≥40 years of age with symptomatic chronic obstructive pulmonary disease (COPD) and ≥1 moderate/severe exacerbation in the previous year. The inclusion criteria for the study were intentionally designed to permit the enrollment of patients with significant concurrent CV disease/risk. CV safety assessments included proportion of patients with and exposure-adjusted rates of on-treatment CV adverse events of special interest (CVAESI) and major adverse cardiac events (MACE), as well as time-to-first (TTF) CVAESI, and TTF CVAESI resulting in hospitalization/prolonged hospitalization or death. RESULTS: Baseline CV risk factors were similar across treatment groups. Overall, 68% of patients (n = 7012) had ≥1 CV risk factor and 40% (n = 4127) had ≥2. At baseline, 29% of patients reported a current/past cardiac disorder and 58% reported a current/past vascular disorder. The proportion of patients with on-treatment CVAESI was 11% for both FF/UMEC/VI and UMEC/VI, and 10% for FF/VI. There was no statistical difference for FF/UMEC/VI versus FF/VI or UMEC/VI in TTF CVAESI (hazard ratio [HR]: 0.98, 95% confidence interval [CI]: 0.85, 1.11; p = 0.711 and HR: 0.92, 95% CI: 0.78, 1.08; p = 0.317, respectively) nor TTF CVAESI leading to hospitalization/prolonged hospitalization or death (HR: 1.19, 95% CI: 0.93, 1.51; p = 0.167 and HR: 0.96, 95% CI: 0.72, 1.27; p = 0.760, respectively). On-treatment MACE occurred in ≤3% of patients across treatment groups, with similar prevalence and rates between treatments. CONCLUSIONS: In a symptomatic COPD population with a history of exacerbations and a high rate of CV disease/risk, the proportion of patients with CVAESI and MACE was 10-11% and 1-3%, respectively, across treatment arms, and the risk of CVAESI was low and similar across treatment arms. There was no statistically significant increased CV risk associated with the use of FF/UMEC/VI versus FF/VI or UMEC/VI, and UMEC/VI versus FF/VI. TRIAL REGISTRATION: NCT02164513 (GSK study number CTT116855)