Programme [11. international LISA symposium, Zurich (Switzerland), 5-9 September 2016

International Nuclear Information System (INIS)

2017-01-01

Monday, 5th of September 2016 Chair: M. Colpi S. Vitale The LTP experiment on LISA Pathfinder and its first results K. Dooley Advanced LIGO: news from the dark universe B. Schutz LIGOs Black Holes and Science in the LISA Era P. McNamara LISA Pathfinder: First steps to observing gravitational waves from space M. Hewitson In-flight Performance of the Optical Metrology System on LISA Pathfinder W. Weber Physical model of the LISA Pathfinder differential acceleration measurement and its application to LISA K. Danzmann The Status of LISA Chair: O. Jennrich J. Martino On-flight characterization of Coldgas micro-Newton thrusters for Lisa Pathfinder M. Nofrarias Magnetic force noise in LISA Pathfinder L. Ferraioli The LISA Pathfinder GRS Front-End Electronics D. Vetrugno The Δ g workflow: from measured displacements to the differential external acceleration. A. Wittchen Coupling of relative intensity noise and pathlength noise to the length measurement in the optical metrology system of LISA Pathfinder S. Paczkowski Laser frequency stabilisation and interferometer path length differences on LISA Pathfinder R. Giusteri The free-fall mode experiment on LISA Pathfinder: first results P. Wass Electrostatic test-mass force-noise disturbances as measured by LISA Pathfinder R. Dolesi The contribution of Brownian noise from viscous gas damping to the differential acceleration noise measured in LISA Pathfinder between two nominally free falling test masses C. Trenkel The engineering of LISA Pathfinder – the quietest laboratory ever flown in space W. Klipstein LISA-derived Flight Phasemeter on the GRACE Follow-On Mission P. Laufer MEMS Ion Thruster Chips to Significantly Enhance Cold Gas Thruster Lifetime for LISA M. Tinto Enhanced Gravitational Wave Science with LISA and gLISA Tuesday, 6th of September 2016 Chair: P. McNamara F. Ricci Advanced VIRGO: State of the Art C. Belczynski Evolutionary predictions in the advanced LIGO/Virgo era A. Sesana The promise of multi

Optimizing the Earth-LISA 'rendezvous'

International Nuclear Information System (INIS)

De Marchi, Fabrizio; Pucacco, Giuseppe; Bassan, Massimo

2012-01-01

We present a general survey of heliocentric LISA orbits, hoping that it might help in the exercise of rescoping the mission. We try to semi-analytically optimize the orbital parameters in order to minimize the disturbances coming from the Earth-LISA interaction. In a set of numerical simulations, we include non-autonomous perturbations and provide an estimate of Doppler shift and breathing as a function of the trailing angle. (paper)

Confusion noise from LISA capture sources

International Nuclear Information System (INIS)

Barack, Leor; Cutler, Curt

2004-01-01

Captures of compact objects (COs) by massive black holes (MBHs) in galactic nuclei will be an important source for LISA, the proposed space-based gravitational wave (GW) detector. However, a large fraction of captures will not be individually resolvable - either because they are too distant, have unfavorable orientation, or have too many years to go before final plunge - and so will constitute a source of 'confusion noise', obscuring other types of sources. In this paper we estimate the shape and overall magnitude of the GW background energy spectrum generated by CO captures. This energy spectrum immediately translates to a spectral density S h capt (f) for the amplitude of capture-generated GWs registered by LISA. The overall magnitude of S h capt (f) is linear in the CO capture rates, which are rather uncertain; therefore we present results for a plausible range of rates. S h capt (f) includes the contributions from both resolvable and unresolvable captures, and thus represents an upper limit on the confusion noise level. We then estimate what fraction of S h capt (f) is due to unresolvable sources and hence constitutes confusion noise. We find that almost all of the contribution to S h capt (f) coming from white dwarf and neutron star captures, and at least ∼30% of the contribution from black hole captures, is from sources that cannot be individually resolved. Nevertheless, we show that the impact of capture confusion noise on the total LISA noise curve ranges from insignificant to modest, depending on the rates. Capture rates at the high end of estimated ranges would raise LISA's overall (effective) noise level [fS h eff (f)] 1/2 by at most a factor ∼2 in the frequency range 1-10 mHz, where LISA is most sensitive. While this slightly elevated noise level would somewhat decrease LISA's sensitivity to other classes of sources, we argue that, overall, this would be a pleasant problem for LISA to have: It would also imply that detection rates for CO captures

Lisa Woodward | IDRC - International Development Research Centre

International Development Research Centre (IDRC) Digital Library (Canada)

Lisa Woodward is Special Advisor to the President. Before joining IDRC, Lisa held positions in strategic planning, performance measurement, evaluation, risk management, and policy development in federal organizations, including Fisheries and Oceans Canada, the Canadian International Development Agency, and the ...

Galactic binaries with eLISA

OpenAIRE

Nelemans, G.

2013-01-01

I review what eLISA will see from Galactic binaries -- double stars with orbital periods less than a few hours and white dwarf (or neutron star/black hole) components. I discuss the currently known binaries that are guaranteed (or verification) sources and explain why the expected total number of eLISA Galactic binaries is several thousand, even though there are large uncertainties in our knowledge of this population, in particular that of the interacting AM CVn systems. I very briefly sketch...

Possible LISA Technology Applications for Other Missions

Science.gov (United States)

Livas, Jeffrey

2018-01-01

The Laser Interferometer Space Antenna (LISA) has been selected as the third large class mission launch opportunity of the Cosmic Visions Program by the European Space Agency (ESA). LISA science will explore a rich spectrum of astrophysical gravitational-wave sources expected at frequencies between 0.0001 and 0.1 Hz and complement the work of other observatories and missions, both space and ground-based, electromagnetic and non-electromagnetic. Similarly, LISA technology may find applications for other missions. This paper will describe the capabilities of some of the key technologies and discuss possible contributions to other missions.

LISA and asteroids

International Nuclear Information System (INIS)

Vinet, Jean-Yves

2006-01-01

LISA is a joint ESA-NASA mission aiming for cosmic gravitational wave detection and analysis. We address here the question of a special kind of signal caused by asteroid encounters. We present a short theory of the detection of such signals

Time-delay interferometry for LISA

International Nuclear Information System (INIS)

Tinto, Massimo; Estabrook, F.B.; Armstrong, J.W.

2002-01-01

LISA (Laser Interferometer Space Antenna) is a mission to detect and study low-frequency cosmic gravitational radiation through its influence on the phases or frequencies of laser beams exchanged between three remote spacecraft. We previously showed how, with lasers of identical frequencies on stationary spacecraft, the measurement of twelve time series of Doppler shifts could be combined to cancel exactly the phase noise of the lasers and the Doppler fluctuations due to noninertial motions of the six optical benches, while preserving gravitational wave signals. Here we generalize those results on gravitational wave detection with time-delay interferometry to the expected LISA instrument. The six lasers have different center frequencies (in the nominal LISA configuration these center frequencies may well differ by several hundred megahertz) and the distances between spacecraft pairs will change with time (these slowly varying orbital Doppler shifts are expected to be up to tens of megahertz). We develop time-delay data combinations which, as previously, preserve gravitational waves and exactly cancel the leading noise source (phase fluctuations of the six lasers); these data combinations then imply transfer functions for the remaining system noises. Using these, we plot frequency and phase power spectra for modeled system noises in the unequal Michelson combination X and the symmetric Sagnac combination ζ. Although optical bench noise can no longer be cancelled exactly, with the current LISA specifications it is suppressed to negligible levels. It is known that the presently anticipated laser center frequency differences and the orbital Doppler drifts introduce another source of phase noise, arising from the onboard oscillators required to track the photodetector fringes. For the presently planned mission, our analysis indeed demonstrates that noise from current-generation ultrastable oscillators would, if uncorrected, dominate the LISA noise budget. To meet the

Laser modulator for LISA pathfinder

Science.gov (United States)

Voland, C.; Lund, G.; Coppoolse, W.; Crosby, P.; Stadler, M.; Kudielka, K.; Özkan, C.

2017-11-01

LISA Pathfinder is an ESA experiment to demonstrate the key technologies needed for the LISA mission to detect gravitational waves in space. The LISA Pathfinder spacecraft represents one arm of the LISA interferometer, containing an optical metrology system and two proof masses as inertial references for the drag-free control system. The LISA Pathfinder payload consists of two drag-free floating test masses located in the inertial sensors with their control electronics and an optical metrology subsystem. The optical metrology subsystem monitors the movement of both test masses relative to each other and to the spacecraft with very high sensitivity and resolution. This is achieved with a heterodyne Mach- Zehnder interferometer. This interferometer requires as input two coherent laser beams with a heterodyne frequency difference of a few kHz. To generate the two laser beams with a heterodyne frequency difference a Nd:YAG laser is used together with the Laser Modulator. The Nd:YAG laser generates a single coherent laser signal at a wavelength of 1064nm which is fibre coupled to the Laser Modulator. The Laser Modulator then generates the two optical beams with the required heterodyne frequency offset. In addition, the Laser Modulator is required to perform laser amplitude stabilization and optical path difference control for the two optical signals. The Laser Modulator consists of an optical unit - the LMU - and RF synthesiser, power amplification and control electronics. These electronics are all housed in the Laser Modulator Electronics (LME). The LMU has four primary functions: • Splitting of the input laser beam into two paths for later superposition in the interferometer. • Applying different frequency shifts to each of the beams. • Providing amplitude modulation control to each of the beams. • Providing active control of the optical path length difference between the two optical paths. The present paper describes the design and performance of the LMU

White-dwarf-white-dwarf galactic background in the LISA data

International Nuclear Information System (INIS)

Edlund, Jeffrey A.; Tinto, Massimo; Krolak, Andrzej; Nelemans, Gijs

2005-01-01

LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own Galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. Our approach relies on entirely analytic expressions of the LISA time-delay interferometric responses to the gravitational radiation emitted by such systems, which allows us to implement a computationally efficient and accurate simulation of the background in the LISA data. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. This suggests that, during this time period, LISA could search for other gravitational wave signals incoming from directions that are away from the galactic plane. Since the galactic white-dwarf background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of 1 yr, we summarize the theory of cyclostationary random processes, present the corresponding generalized spectral method needed to characterize such process, and make a comparison between our analytic results and those obtained by applying our method to the simulated data. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarf binary systems present in our Galaxy

LISA and its in-flight test precursor SMART-2

International Nuclear Information System (INIS)

Vitale, S.; Bender, P.; Brillet, A.; Buchman, S.; Cavalleri, A.; Cerdonio, M.; Cruise, M.; Cutler, C.; Danzmann, K.; Dolesi, R.; Folkner, W.; Gianolio, A.; Jafry, Y.; Hasinger, G.; Heinzel, G.; Hogan, C.; Hueller, M.; Hough, J.; Phinney, S.; Prince, T.; Richstone, D.; Robertson, D.; Rodrigues, M.; Ruediger, A.; Sandford, M.; Schilling, R.; Shoemaker, D.; Schutz, B.; Stebbins, R.; Stubbs, C.; Sumner, T.; Thorne, K.; Tinto, M.; Touboul, P.; Ward, H.; Weber, W.; Winkler, W.

2002-01-01

LISA will be the first space-home gravitational wave observatory. It aims to detect gravitational waves in the 0.1 mHz/1 Hz range from sources including galactic binaries, super-massive black-hole binaries, capture of objects by super-massive black-holes and stochastic background. LISA is an ESA approved Cornerstone Mission foreseen as a joint ESA-NASA endeavour to be launched in 2010-11. The principle of operation of LISA is based on laser ranging of test-masses under pure geodesic motion. Achieving pure geodesic motion at the level requested for LISA, 3x10 -15 ms -2 /√Hz at 0.1 mHz, is considered a challenging technological objective. To reduce the risk, both ESA and NASA are pursuing an in-flight test of the relevant technology. The goal of the test is to demonstrate geodetic motion within one order of magnitude from the LISA performance. ESA has given this test as the primary goal of its technology dedicated mission SMART-2 with a launch in 2006. This paper describes the basics of LISA, its key technologies, and its in-flight precursor test on SMART-2

LISA: Probing the Universe with Gravitational Waves

NARCIS (Netherlands)

Prince, T.A.; Binetruy, P.; Centrella, J.; Finn, L.S.; Hogan, C.; Nelemans, G.A.; Phinney, E.S.; Schutz, B.; Team, L.I.S.

2006-01-01

LISA is a joint NASA/ESA space mission for detection and study of low-frequency gravitational waves in the band from 0.1 mHz to 0.1 Hz. The mission consists of three satellites separated by a nominal distance of 5 million kilometers, with precision metrology provided by laser ranging. LISA will

Gravitational Reference Sensor Front-End Electronics Simulator for LISA

International Nuclear Information System (INIS)

Meshksar, Neda; Ferraioli, Luigi; Mance, Davor; Zweifel, Peter; Giardini, Domenico; Ten Pierick, Jan

2017-01-01

At the ETH Zurich we are developing a modular simulator that provides a realistic simulation of the Front End Electronics (FEE) for LISA Gravitational Reference Sensor (GRS). It is based on the GRS FEE-simulator already implemented for LISA Pathfinder. It considers, in particular, the non-linearity and the critical details of hardware, such as the non-linear multiplicative noise caused by voltage reference instability, test mass charging and detailed actuation and sensing algorithms. We present the simulation modules, considering the above-mentioned features. Based on the ETH GRS FEE-simulator for LISA Pathfinder we aim to develop a modular simulator that provides a realistic simulation of GRS FEE for LISA. (paper)

Lisa Jevbratt / Lisa Jevbratt ; interv. Tilman Baumgärtel

Index Scriptorium Estoniae

Jevbratt, Lisa

2006-01-01

1967. a. Rootsis sündinud ja USA-s elavast kunstnikust Lisa Jevbrattist ning tema loomingust, 2000. a. jaanuaris tehtud meiliintervjuu kunstnikuga. L. Jevbratt kuulub rühmitusse C5, tema teosed keskenduvad pigem Interneti struktuurile kui selle sisule. Pikemalt võrguteosest "1:1" (2000), mille teemaks on IP-aadressid., lühidalt tööst "The Stillman Project" (1997), kunstniku galeriist "Non-Site"

Mona Lisa kuulsa naeratuse saladus leidis lahenduse / Johannes Saar

Index Scriptorium Estoniae

Saar, Johannes, 1965-

2004-01-01

Firenze kunstiajalooõpetaja Giuseppe Pallanti jõudis 25-aastase arhiivitöö tulemusena järeldusele, et Leonardo da Vinci Mona Lisa modelliks on siidikaupmehe Francesco del Giocondo abikaasa Lisa Gerardini

Reconstructing the dark sector interaction with LISA

Energy Technology Data Exchange (ETDEWEB)

Cai, Rong-Gen; Yang, Tao [CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China); Tamanini, Nicola, E-mail: cairg@itp.ac.cn, E-mail: nicola.tamanini@cea.fr, E-mail: yangtao@itp.ac.cn [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

2017-05-01

We perform a forecast analysis of the ability of the LISA space-based interferometer to reconstruct the dark sector interaction using gravitational wave standard sirens at high redshift. We employ Gaussian process methods to reconstruct the distance-redshift relation in a model independent way. We adopt simulated catalogues of standard sirens given by merging massive black hole binaries visible by LISA, with an electromagnetic counterpart detectable by future telescopes. The catalogues are based on three different astrophysical scenarios for the evolution of massive black hole mergers based on the semi-analytic model of E. Barausse, Mon. Not. Roy. Astron. Soc. 423 (2012) 2533. We first use these standard siren datasets to assess the potential of LISA in reconstructing a possible interaction between vacuum dark energy and dark matter. Then we combine the LISA cosmological data with supernovae data simulated for the Dark Energy Survey. We consider two scenarios distinguished by the time duration of the LISA mission: 5 and 10 years. Using only LISA standard siren data, the dark sector interaction can be well reconstructed from redshift z ∼1 to z ∼3 (for a 5 years mission) and z ∼1 up to z ∼5 (for a 10 years mission), though the reconstruction is inefficient at lower redshift. When combined with the DES datasets, the interaction is well reconstructed in the whole redshift region from 0 z ∼ to z ∼3 (5 yr) and z ∼0 to z ∼5 (10 yr), respectively. Massive black hole binary standard sirens can thus be used to constrain the dark sector interaction at redshift ranges not reachable by usual supernovae datasets which probe only the z ∼< 1.5 range. Gravitational wave standard sirens will not only constitute a complementary and alternative way, with respect to familiar electromagnetic observations, to probe the cosmic expansion, but will also provide new tests to constrain possible deviations from the standard ΛCDM dynamics, especially at high redshift.

A noise simulator for eLISA: Migrating LISA Pathfinder knowledge to the eLISA mission

OpenAIRE

Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, Michael; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, Karsten; Diepholz, I.

2015-01-01

We present a new technical simulator for the eLISA mission, based on state space modeling techniques and developed in MATLAB. This simulator computes the coordinate and velocity over time of each body involved in the constellation, i.e. the spacecraft and its test masses, taking into account the different disturbances and actuations. This allows studying the contribution of instrumental noises and system imperfections on the residual acceleration applied on the TMs, the latter reflecting the ...

THE LISA GRAVITATIONAL WAVE FOREGROUND: A STUDY OF DOUBLE WHITE DWARFS

International Nuclear Information System (INIS)

Ruiter, Ashley J.; Belczynski, Krzysztof; Benacquista, Matthew; Williams, Gabriel; Larson, Shane L.

2010-01-01

Double white dwarfs (WDs) are expected to be a source of confusion-limited noise for the future gravitational wave observatory LISA. In a specific frequency range, this 'foreground noise' is predicted to rise above the instrumental noise and hinder the detection of other types of signals, e.g., gravitational waves arising from stellar-mass objects inspiraling into massive black holes. In many previous studies, only detached populations of compact object binaries have been considered in estimating the LISA gravitational wave foreground signal. Here, we investigate the influence of compact object detached and Roche-Lobe overflow (RLOF) Galactic binaries on the shape and strength of the LISA signal. Since >99% of remnant binaries that have orbital periods within the LISA sensitivity range are WD binaries, we consider only these binaries when calculating the LISA signal. We find that the contribution of RLOF binaries to the foreground noise is negligible at low frequencies, but becomes significant at higher frequencies, pushing the frequency at which the foreground noise drops below the instrumental noise to >6 mHz. We find that it is important to consider the population of mass-transferring binaries in order to obtain an accurate assessment of the foreground noise on the LISA data stream. However, we estimate that there still exists a sizeable number (∼11,300) of Galactic double WD binaries that will have a signal-to-noise ratio >5, and thus will be potentially resolvable with LISA. We present the LISA gravitational wave signal from the Galactic population of WD binaries, show the most important formation channels contributing to the LISA disk and bulge populations, and discuss the implications of these new findings.

A UV LED-based Charge Management System for LISA

Science.gov (United States)

Conklin, John W.; Chilton, Andrew; Olatunde, Taiwo Janet; Apple, Stephen; Parry, Samantha; Ciani, Giacomo; Wass, Peter; Mueller, Guido

2018-01-01

The Laser Interferometer Space Antenna (LISA) will be the first space instrument to observe gravitational waves in the millihertz frequency band. LISA consists of three Sun-orbiting spacecraft that form an equilateral triangle, with each side measuring 2.5 million kilometers in length. Each spacecraft houses two free-floating test masses, which are protected from all disturbing forces so that they follow pure geodesics in spacetime. A drag-free control system commands micronewton thrusters to force the spacecraft to fly in formation with the test masses and laser interferometers measure the minute variations in the distance, or light travel time, between these free-falling test masses caused by gravitational waves. The LISA observatory, with a planned launch in the early 2030s, is led by the European Space Agency with significant contributions from NASA. Recently, NASA has initiated strategic investments in key LISA technologies that will likely become U.S. flight hardware contributions to this ground-breaking mission. One of these payload elements is the Charge Management System (CMS), which controls the electric potential of the test masses relative to their housings to reduce spurious force noise acting on the test masses to below the required level. This talk, presented by University of Florida team that leads the CMS development, will describe this vital U.S. contribution to the LISA mission in the context of the envisioned LISA payload architecture and its in-flight sensitivity to gravitational waves.

The Breadboard model of the LISA telescope assembly

Science.gov (United States)

Lucarelli, S.; Scheulen, D.; Kemper, D.; Sippel, R.; Verlaan, A.; Hogenhuis, H.; Ende, D.

2017-11-01

The primary goal of the LISA mission is the detection of gravitational waves from astronomical sources in a frequency range of 10-4 to 1 Hz. This requires operational stabilities in the picometer range as well as highly predictable mechanical distortions upon cooling down, outgassing in space, and gravity release. In March 2011 ESA announced a new way forward for the Lclass candidate missions, including LISA. ESA and the scientific community are now studying options for European-only missions that offer a significant reduction of the costs, while maintaining their core science objectives. In this context LISA has become the New Gravitational wave Observatory (NGO). Despite this reformulation, the need for dimensional stability in the picometer range remains valid, and ESA have continued the corresponding LISA Technology Development Activities (TDA's) also in view of NGO. In such frame Astrium GmbH and xperion (Friedrichshafen, Germany) have designed and manufactured an ultra-stable CFRP breadboard of the LISA telescope in order to experimentally demonstrate that the structure and the M1 & M2 mirror mounts are fulfilling the LISA requirements in the mission operational thermal environment. Suitable techniques to mount the telescope mirrors and to support the M1 & M2 mirrors have been developed, with the aim of measuring a system CTE of less than 10-7 K-1 during cooling down to -80°C. Additionally to the stringent mass and stiffness specifications, the required offset design makes the control of relative tilts and lateral displacements between the M1 and M2 mirrors particularly demanding. The thermo-elastic performance of the telescope assembly is going to be experimentally verified by TNO (Delft, The Netherlands) starting from the second half of 2012. This paper addresses challenges faced in the design phase, shows the resulting hardware and present first outcomes of the test campaign performed at TNO.

Charge Management in LISA Pathfinder: The Continuous Discharging Experiment

Science.gov (United States)

Ewing, Becca Elizabeth

2018-01-01

Test mass charging is a significant source of excess force and force noise in LISA Pathfinder (LPF). The planned design scheme for mitigation of charge induced force noise in LISA is a continuous discharge by UV light illumination. We report on analysis of a charge management experiment on-board LPF conducted during December 2016. We discuss the measurement of test mass charging noise with and without continuous UV illumination, in addition to the dynamic response in the continuous discharge scheme. Results of the continuous discharge system will be discussed for their application to operating LISA with lower test mass charge.

Optimal statistic for detecting gravitational wave signals from binary inspirals with LISA

CERN Document Server

Rogan, A

2004-01-01

A binary compact object early in its inspiral phase will be picked up by its nearly monochromatic gravitational radiation by LISA. But even this innocuous appearing candidate poses interesting detection challenges. The data that will be scanned for such sources will be a set of three functions of LISA's twelve data streams obtained through time-delay interferometry, which is necessary to cancel the noise contributions from laser-frequency fluctuations and optical-bench motions to these data streams. We call these three functions pseudo-detectors. The sensitivity of any pseudo-detector to a given sky position is a function of LISA's orbital position. Moreover, at a given point in LISA's orbit, each pseudo-detector has a different sensitivity to the same sky position. In this work, we obtain the optimal statistic for detecting gravitational wave signals, such as from compact binaries early in their inspiral stage, in LISA data. We also present how the sensitivity of LISA, defined by this optimal statistic, vari...

Data analysis for the LISA Technology Package

Energy Technology Data Exchange (ETDEWEB)

Hewitson, M; Danzmann, K; Diepholz, I; GarcIa, A [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik und Universitaet Hannover, 30167 Hannover (Germany); Armano, M; Fauste, J [European Space Agency, ESAC, Villanueva de la Canada, 28692 Madrid (Spain); Benedetti, M [Dipartimento di Ingegneria dei Materiali e Tecnologie Industriali, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Bogenstahl, J [Department of Physics and Astronomy, University of Glasgow, Glasgow (United Kingdom); Bortoluzzi, D; Bosetti, P; Cristofolini, I [Dipartimento di Ingegneria Meccanica e Strutturale, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Brandt, N [Astrium GmbH, 88039 Friedrichshafen (Germany); Cavalleri, A; Ciani, G; Dolesi, R; Ferraioli, L [Dipartimento di Fisica, Universita di Trento and INFN, Gruppo Collegato di Trento, 38050 Povo, Trento (Italy); Cruise, M [Department of Physics and Astronomy, University of Birmingham, Birmingham (United Kingdom); Fertin, D; GarcIa, C [European Space Agency, ESTEC, 2200 AG Noordwijk (Netherlands); Fichter, W, E-mail: martin.hewitson@aei.mpg.d [Institut fuer Flugmechanik und Flugregelung, 70569 Stuttgart (Germany)

2009-05-07

The LISA Technology Package (LTP) on board the LISA Pathfinder mission aims to demonstrate some key concepts for LISA which cannot be tested on ground. The mission consists of a series of preplanned experimental runs. The data analysis for each experiment must be designed in advance of the mission. During the mission, the analysis must be carried out promptly so that the results can be fed forward into subsequent experiments. As such a robust and flexible data analysis environment needs to be put in place. Since this software is used during mission operations and effects the mission timeline, it must be very robust and tested to a high degree. This paper presents the requirements, design and implementation of the data analysis environment (LTPDA) that will be used for analysing the data from LTP. The use of the analysis software to perform mock data challenges (MDC) is also discussed, and some highlights from the first MDC are presented.

Data analysis for the LISA Technology Package

International Nuclear Information System (INIS)

Hewitson, M; Danzmann, K; Diepholz, I; GarcIa, A; Armano, M; Fauste, J; Benedetti, M; Bogenstahl, J; Bortoluzzi, D; Bosetti, P; Cristofolini, I; Brandt, N; Cavalleri, A; Ciani, G; Dolesi, R; Ferraioli, L; Cruise, M; Fertin, D; GarcIa, C; Fichter, W

2009-01-01

The LISA Technology Package (LTP) on board the LISA Pathfinder mission aims to demonstrate some key concepts for LISA which cannot be tested on ground. The mission consists of a series of preplanned experimental runs. The data analysis for each experiment must be designed in advance of the mission. During the mission, the analysis must be carried out promptly so that the results can be fed forward into subsequent experiments. As such a robust and flexible data analysis environment needs to be put in place. Since this software is used during mission operations and effects the mission timeline, it must be very robust and tested to a high degree. This paper presents the requirements, design and implementation of the data analysis environment (LTPDA) that will be used for analysing the data from LTP. The use of the analysis software to perform mock data challenges (MDC) is also discussed, and some highlights from the first MDC are presented.

Accreting Double White Dwarf Binaries: Implications for LISA

International Nuclear Information System (INIS)

Kremer, Kyle; Breivik, Katelyn; Larson, Shane L.; Kalogera, Vassiliki

2017-01-01

We explore the long-term evolution of mass-transferring white dwarf (WD) binaries undergoing both direct-impact and disk accretion and explore implications of such systems to gravitational-wave (GW) astronomy. We cover a broad range of initial component masses and show that these systems, the majority of which lie within the Laser Interferometer Space Antenna ( LISA ) sensitivity range, exhibit prominent negative orbital frequency evolution (chirp) for a significant fraction of their lifetimes. Using a galactic population synthesis, we predict ∼2700 of these systems will be observable with a negative chirp of 0.1 yr −2 by a space-based GW detector like LISA . We also show that detections of mass-transferring double WD systems by LISA may provide astronomers with unique ways of probing the physics governing close compact object binaries.

Accreting Double White Dwarf Binaries: Implications for LISA

Energy Technology Data Exchange (ETDEWEB)

Kremer, Kyle; Breivik, Katelyn; Larson, Shane L.; Kalogera, Vassiliki, E-mail: kremer@u.northwestern.edu, E-mail: katelyn.breivik@northwestern.edu, E-mail: vicky@northwestern.edu, E-mail: s.larson@northwestern.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, Northwestern University 2145 Sheridan Road, Evanston, IL 60201 (United States)

2017-09-10

We explore the long-term evolution of mass-transferring white dwarf (WD) binaries undergoing both direct-impact and disk accretion and explore implications of such systems to gravitational-wave (GW) astronomy. We cover a broad range of initial component masses and show that these systems, the majority of which lie within the Laser Interferometer Space Antenna ( LISA ) sensitivity range, exhibit prominent negative orbital frequency evolution (chirp) for a significant fraction of their lifetimes. Using a galactic population synthesis, we predict ∼2700 of these systems will be observable with a negative chirp of 0.1 yr{sup −2} by a space-based GW detector like LISA . We also show that detections of mass-transferring double WD systems by LISA may provide astronomers with unique ways of probing the physics governing close compact object binaries.

Accreting Double White Dwarf Binaries: Implications for LISA

Science.gov (United States)

Kremer, Kyle; Breivik, Katelyn; Larson, Shane L.; Kalogera, Vassiliki

2017-09-01

We explore the long-term evolution of mass-transferring white dwarf (WD) binaries undergoing both direct-impact and disk accretion and explore implications of such systems to gravitational-wave (GW) astronomy. We cover a broad range of initial component masses and show that these systems, the majority of which lie within the Laser Interferometer Space Antenna (LISA) sensitivity range, exhibit prominent negative orbital frequency evolution (chirp) for a significant fraction of their lifetimes. Using a galactic population synthesis, we predict ˜2700 of these systems will be observable with a negative chirp of 0.1 yr-2 by a space-based GW detector like LISA. We also show that detections of mass-transferring double WD systems by LISA may provide astronomers with unique ways of probing the physics governing close compact object binaries.

Distinguishing Between Formation Channels for Binary Black Holes with LISA

Science.gov (United States)

Breivik, Katelyn; Rodriguez, Carl L.; Larson, Shane L.; Kalogera, Vassiliki; Rasio, Frederic A.

2017-01-01

The recent detections of GW150914 and GW151226 imply an abundance of stellar-mass binary-black-hole mergers in the local universe. While ground-based gravitational-wave detectors are limited to observing the final moments before a binary merges, space-based detectors, such as the Laser Interferometer Space Antenna (LISA), can observe binaries at lower orbital frequencies where such systems may still encode information about their formation histories. In particular, the orbital eccentricity and mass of binary black holes in the LISA frequency band can be used together to discriminate between binaries formed in isolation in galactic fields and those formed in dense stellar environments such as globular clusters. In this letter, we explore the orbital eccentricity and mass of binary-black-hole populations as they evolve through the LISA frequency band. Overall we find that there are two distinct populations discernible by LISA. We show that up to ~90% of binaries formed either dynamically or in isolation have eccentricities measurable by LISA. Finally, we note how measured eccentricities of low-mass binary black holes evolved in isolation could provide detailed constraints on the physics of black-hole natal kicks and common-envelope evolution.

A study on the radionuclide migration by means of the code LISA

International Nuclear Information System (INIS)

Frenquellucci, F.; Deserti, M.

1989-01-01

LISA code (Long Term Isolation Safety Assessment) has been developed by J.R.C. EUROATOM Ispra (Radiochemistry Division) and it's utilized in order to study migration of radionuclides through porous media. Aim of the present work is to analyze LISA's input and output files. A brief description of the code is also performed. As LISA is a research and in development code, its structure is rather complex and an exhaustive description of input/output files is helpful for the user. Version 3 of LISA code, loaded on ENEA's IBM 3090, is avaylable by ENEA-VEL Bologna

Possible LISA follow-on mission scientific objectives

International Nuclear Information System (INIS)

Bender, Peter L; Begelman, Mitchell C; Gair, Jonathan R

2013-01-01

A major objective that has been suggested for a follow-on mission to a Laser Interferometer Space Antenna (LISA)-type mission is to investigate more completely how intermediate mass black holes were formed and grew in the early universe, before they evolved into the much more massive black holes at the centers of many galaxies today. The actual design of such a follow-on mission will of course depend on what is observed by a LISA-type mission, such as the recently modified proposal for an evolved LISA mission, with the interferometer arm lengths between spacecraft reduced from 5 million to 1 million km. However, the sensitivity goals of a follow-on mission are likely to be influenced strongly by the desire to be able to see mergers of 10 M ⊙ black holes with roughly 3000 M ⊙ or larger intermediate mass black holes out to as large redshifts as possible. Approximate calculations of the expected signal-to-noise have been made for a possible LISA follow-on mission that was suggested about eight years ago (Bender and Begelman 2005 Trends in Space Science and Cosmic Vision 2020 (Noordwijk: ESA Publications Division) pp 33–38), and was called the Advanced Laser Interferometer Antenna. Based on the calculations, it appears that detections out to a redshift of 10 would be possible for 10 M ⊙ black holes spiraling into perhaps 5000 M ⊙ or larger intermediate mass black holes if the extragalactic gravitational wave background due to close white dwarf binaries is in the currently estimated range. (paper)

Interferometry for the LISA technology package LTP: an update

International Nuclear Information System (INIS)

Heinzel, G; Bogenstahl, J; Braxmaier, C; Danzmann, K; Garcia, A; Guzman, F; Hough, J; Hoyland, D; Jennrich, O; Killow, C; Robertson, D; Sodnik, Z; Steier, F; Ward, H; Wand, V

2006-01-01

This paper gives an update on the status of the LISA technology package (LTP) which is to be launched in 2009 by ESA as a technology demonstration mission for the spaceborne gravitational wave observatory LISA. The dominant noise source in the interferometer prototype has been investigated and improved such that it is now comfortably below its budget at all frequencies

Constraining stellar binary black hole formation scenarios with eLISA eccentricity measurements

Science.gov (United States)

Nishizawa, Atsushi; Sesana, Alberto; Berti, Emanuele; Klein, Antoine

2017-03-01

A space-based interferometer such as the evolved Laser Interferometer Space Antenna (eLISA) could observe a few to a few thousands of progenitors of black hole binaries (BHBs) similar to those recently detected by Advanced LIGO. Gravitational radiation circularizes the orbit during inspiral, but some BHBs retain a measurable eccentricity at the low frequencies where eLISA is the most sensitive. The eccentricity of a BHB carries precious information about its formation channel: BHBs formed in the field, in globular clusters, or close to a massive black hole (MBH) have distinct eccentricity distributions in the eLISA band. We generate mock eLISA observations, folding in measurement errors, and using a Bayesian model selection, we study whether eLISA measurements can identify the BHB formation channel. We find that a handful of observations would suffice to tell whether BHBs were formed in the gravitational field of an MBH. Conversely, several tens of observations are needed to tell apart field formation from globular cluster formation. A 5-yr eLISA mission with the longest possible armlength is desirable to shed light on BHB formation scenarios.

Control system design for the constellation acquisition phase of the LISA mission

Energy Technology Data Exchange (ETDEWEB)

Cirillo, Francesca; Gath, Peter F, E-mail: francesca.cirillo@astrium.eads.ne, E-mail: peter.gath@astrium.eads.ne [Astrium GmbH Satellites, 88039 Friedrichshafen (Germany)

2009-03-01

The objective of the constellation acquisition phase for the LISA mission is to establish the three laser links between the three spacecraft of the LISA constellation so that the interferometric measurements for the science experiment can commence. The laser beam acquisition for LISA is extremely challenging given the 5 million km distance between the spacecraft, the inherent limits of the attitude sensors accuracy, the orbit determination accuracy issues and the time required to phase-lock the incoming and outgoing laser signals. This paper presents the design of the control system for the acquisition phase of the LISA constellation: the acquisition operational procedure is outlined, guidance laws are defined together with the Gyro Mode attitude control principle, which implements a Kalman filter for disturbances rejection purposes. Constellation-wide non-linear simulations demonstrate that the LISA constellation acquisition phase is feasible by means of the proposed control strategy.

Control system design for the constellation acquisition phase of the LISA mission

International Nuclear Information System (INIS)

Cirillo, Francesca; Gath, Peter F

2009-01-01

The objective of the constellation acquisition phase for the LISA mission is to establish the three laser links between the three spacecraft of the LISA constellation so that the interferometric measurements for the science experiment can commence. The laser beam acquisition for LISA is extremely challenging given the 5 million km distance between the spacecraft, the inherent limits of the attitude sensors accuracy, the orbit determination accuracy issues and the time required to phase-lock the incoming and outgoing laser signals. This paper presents the design of the control system for the acquisition phase of the LISA constellation: the acquisition operational procedure is outlined, guidance laws are defined together with the Gyro Mode attitude control principle, which implements a Kalman filter for disturbances rejection purposes. Constellation-wide non-linear simulations demonstrate that the LISA constellation acquisition phase is feasible by means of the proposed control strategy.

240 nm UV LEDs for LISA test mass charge control

Science.gov (United States)

Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Serra, Paul; Ciani, Giacomo; Mueller, Guido; Conklin, John

2015-05-01

Test Masses inside the LISA Gravitational Reference Sensor must maintain almost pure geodesic motion for gravitational waves to be successfully detected. LISA requires residual test mass accelerations below 3 fm/s2/√Hz at all frequencies between 0.1 and 3 mHz. One of the well-known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electromagnetic fields. LISA Pathfinder will use Hg-discharge lamps emitting mostly around 254 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. Presented here is a preliminary study of the effectiveness of charge control using latest generation UV-LEDs which produce light at 240 nm with energy above the work function of pure Au. Their lower mass, better power efficiency and small size make them an ideal replacement for Hg lamps.

240 nm UV LEDs for LISA test mass charge control

International Nuclear Information System (INIS)

Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Serra, Paul; Ciani, Giacomo; Mueller, Guido; Conklin, John

2015-01-01

Test Masses inside the LISA Gravitational Reference Sensor must maintain almost pure geodesic motion for gravitational waves to be successfully detected. LISA requires residual test mass accelerations below 3 fm/s 2 /√Hz at all frequencies between 0.1 and 3 mHz. One of the well-known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electromagnetic fields. LISA Pathfinder will use Hg-discharge lamps emitting mostly around 254 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. Presented here is a preliminary study of the effectiveness of charge control using latest generation UV-LEDs which produce light at 240 nm with energy above the work function of pure Au. Their lower mass, better power efficiency and small size make them an ideal replacement for Hg lamps. (paper)

Inference on inspiral signals using LISA MLDC data

International Nuclear Information System (INIS)

Roever, Christian; Stroeer, Alexander; Bloomer, Ed; Christensen, Nelson; Clark, James; Hendry, Martin; Messenger, Chris; Meyer, Renate; Pitkin, Matt; Toher, Jennifer; Umstaetter, Richard; Vecchio, Alberto; Veitch, John; Woan, Graham

2007-01-01

In this paper, we describe a Bayesian inference framework for the analysis of data obtained by LISA. We set up a model for binary inspiral signals as defined for the Mock LISA Data Challenge 1.2 (MLDC), and implemented a Markov chain Monte Carlo (MCMC) algorithm to facilitate exploration and integration of the posterior distribution over the nine-dimensional parameter space. Here, we present intermediate results showing how, using this method, information about the nine parameters can be extracted from the data

The Engineering of LISA Pathfinder – the quietest Laboratory ever flown in Space

International Nuclear Information System (INIS)

Trenkel, Christian; Wealthy, Dave; Dunbar, Neil; Warren, Carl; Schleicher, Alexander; Ziegler, Tobias; Brandt, Nico; Gerndt, Rüdiger

2017-01-01

We review the engineering approach adopted to ensure the required gravitational, magnetic, thermal and residual acceleration stability on-board LISA Pathfinder, and present the in-flight results that have been achieved. Arguably, this stability makes LISA Pathfinder the quietest laboratory ever flown in space. The implications for LISA are also discussed. (paper)

Lisa's Lemonade Stand: Exploring Algebraic Ideas.

Science.gov (United States)

Billings, Esther M. H.; Lakatos, Tracy

2003-01-01

Presents an activity, "Lisa's Lemonade Stand," that actively engages students in algebraic thinking as they analyze change by investigating relationships between variables and gain experience describing and representing these relationships graphically. (YDS)

LISA Pathfinder: hardware tests and their input to the mission

Science.gov (United States)

Audley, Heather

The Laser Interferometer Space Antenna (LISA) is a joint ESA-NASA mission for the first space-borne gravitational wave detector. LISA aims to detect sources in the 0.1mHz to 1Hz range, which include supermassive black holes and galactic binary stars. Core technologies required for the LISA mission, including drag-free test mass control, picometre interferometry and micro-Newton thrusters, cannot be tested on-ground. Therefore, a precursor satellite, LISA Pathfinder, has been developed as a technology demonstration mission. The preparations for the LISA Pathfinder mission have reached an exciting stage. Tests of the engineering model of the optical metrology system have recently been completed at the Albert Einstein Institute, Hannover, and flight model tests are now underway. Significantly, they represent the first complete integration and testing of the space-qualified hardware and are the first tests on system level. The results and test procedures of these campaigns will be utilised directly in the ground-based flight hardware tests, and subsequently within in-flight operations. In addition, they allow valuable testing of the data analysis methods using the MatLab based LTP data analysis toolbox. This contribution presents an overview of the test campaigns calibration, control and perfor-mance results, focusing on the implications for the Experimental Master Plan which provides the basis for the in-flight operations and procedures.

Data Analysis for the LISA Pathfinder Mission

Science.gov (United States)

Thorpe, James Ira

2009-01-01

The LTP (LISA Technology Package) is the core part of the Laser Interferometer Space Antenna (LISA) Pathfinder mission. The main goal of the mission is to study the sources of any disturbances that perturb the motion of the freely-falling test masses from their geodesic trajectories as well as 10 test various technologies needed for LISA. The LTP experiment is designed as a sequence of experimental runs in which the performance of the instrument is studied and characterized under different operating conditions. In order to best optimize subsequent experimental runs, each run must be promptly analysed to ensure that the following ones make best use of the available knowledge of the instrument ' In order to do this, all analyses must be designed and tested in advance of the mission and have sufficient built-in flexibility to account for unexpected results or behaviour. To support this activity, a robust and flexible data analysis software package is also required. This poster presents two of the main components that make up the data analysis effort: the data analysis software and the mock-data challenges used to validate analysis procedures and experiment designs.

LISA Pathfinder instrument data analysis

Science.gov (United States)

Guzman, Felipe

LISA Pathfinder (LPF) is an ESA-launched demonstration mission of key technologies required for the joint NASA-ESA gravitational wave observatory in space, LISA. As part of the LPF interferometry investigations, analytic models of noise sources and corresponding noise subtrac-tion techniques have been developed to correct for effects like the coupling of test mass jitter into displacement readout, and fluctuations of the laser frequency or optical pathlength difference. Ground testing of pre-flight hardware of the Optical Metrology Subsystem is currently ongoing at the Albert Einstein Institute Hannover. In collaboration with NASA Goddard Space Flight Center, the LPF mission data analysis tool LTPDA is being used to analyze the data product of these tests. Furthermore, the noise subtraction techniques and in-flight experiment runs for noise characterization are being defined as part of the mission experiment master plan. We will present the data analysis outcome of pre-flight hardware ground tests and possible noise subtraction strategies for in-flight instrument operations.

LISA Mission and System architectures and performances

International Nuclear Information System (INIS)

Gath, Peter F; Weise, Dennis; Schulte, Hans-Reiner; Johann, Ulrich

2009-01-01

In the context of the LISA Mission Formulation Study, the LISA System was studied in detail and a new baseline architecture for the whole mission was established. This new baseline is the result of trade-offs on both, mission and system level. The paper gives an overview of the different mission scenarios and configurations that were studied in connection with their corresponding advantages and disadvantages as well as performance estimates. Differences in the required technologies and their influence on the overall performance budgets are highlighted for all configurations. For the selected baseline concept, a more detailed description of the configuration is given and open issues in the technologies involved are discussed.

LISA Mission and System architectures and performances

Energy Technology Data Exchange (ETDEWEB)

Gath, Peter F; Weise, Dennis; Schulte, Hans-Reiner; Johann, Ulrich, E-mail: peter.gath@astrium.eads.ne [Astrium GmbH Satellites, 88039 Friedrichshafen (Germany)

2009-03-01

In the context of the LISA Mission Formulation Study, the LISA System was studied in detail and a new baseline architecture for the whole mission was established. This new baseline is the result of trade-offs on both, mission and system level. The paper gives an overview of the different mission scenarios and configurations that were studied in connection with their corresponding advantages and disadvantages as well as performance estimates. Differences in the required technologies and their influence on the overall performance budgets are highlighted for all configurations. For the selected baseline concept, a more detailed description of the configuration is given and open issues in the technologies involved are discussed.

Bayesian statistics for the calibration of the LISA Pathfinder experiment

International Nuclear Information System (INIS)

Armano, M; Freschi, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

2015-01-01

The main goal of LISA Pathfinder (LPF) mission is to estimate the acceleration noise models of the overall LISA Technology Package (LTP) experiment on-board. This will be of crucial importance for the future space-based Gravitational-Wave (GW) detectors, like eLISA. Here, we present the Bayesian analysis framework to process the planned system identification experiments designed for that purpose. In particular, we focus on the analysis strategies to predict the accuracy of the parameters that describe the system in all degrees of freedom. The data sets were generated during the latest operational simulations organised by the data analysis team and this work is part of the LTPDA Matlab toolbox. (paper)

E. Yiannopoulou on Lisa Blackman’s The Body.

Directory of Open Access Journals (Sweden)

2009-11-01

Full Text Available Blackman, Lisa. The Body. Oxford and New York: Berg, 2008. 160 pp. “Is there anything natural about the human body?” (1. This is how Lisa Blackman begins her all too daunting task of reviewing and critically evaluating what has come to be known as “body theory” in the field of sociology. Carefully picking her way among numerous theories on the corporeal that have been produced across the humanities in the last twenty years, Blackman lays out her problematic from the start by asking to know w...

Implementation of time-delay interferometry for LISA

International Nuclear Information System (INIS)

Tinto, Massimo; Shaddock, Daniel A.; Sylvestre, Julien; Armstrong, J.W.

2003-01-01

We discuss the baseline optical configuration for the Laser Interferometer Space Antenna (LISA) mission, in which the lasers are not free-running, but rather one of them is used as the main frequency reference generator (the master) and the remaining five as slaves, these being phase-locked to the master (the master-slave configuration). Under the condition that the frequency fluctuations due to the optical transponders can be made negligible with respect to the secondary LISA noise sources (mainly proof-mass and shot noises), we show that the entire space of interferometric combinations LISA can generate when operated with six independent lasers (the one-way method) can also be constructed with the master-slave system design. The corresponding hardware trade-off analysis for these two optical designs is presented, which indicates that the two sets of systems needed for implementing the one-way method, and the master-slave configuration, are essentially identical. Either operational mode could therefore be implemented without major implications on the hardware configuration. We then derive the required accuracies of armlength knowledge, time synchronization of the onboard clocks, sampling times and time-shifts needed for effectively implementing time-delay interferometry for LISA. We find that an armlength accuracy of about 16 meters, a synchronization accuracy of about 50 ns, and the time jitter due to a presently existing space qualified clock will allow the suppression of the frequency fluctuations of the lasers below to the level identified by the secondary noise sources. A new procedure for sampling the data in such a way to avoid the problem of having time shifts that are not integer multiples of the sampling time is also introduced, addressing one of the concerns about the implementation of time-delay interferometry

Report on the first round of the Mock LISA Data Challenges

International Nuclear Information System (INIS)

Arnaud, K A; Auger, G; Babak, S

2007-01-01

The Mock LISA Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data analysis tools and capabilities, and demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data output. The first round of MLDCs has just been completed: nine challenges consisting of data sets containing simulated gravitational-wave signals produced either by galactic binaries or massive black hole binaries embedded in simulated LISA instrumental noise were released in June 2006 with deadline for submission of results at the beginning of December 2006. Ten groups have participated in this first round of challenges. All of the challenges had at least one entry which successfully characterized the signal to better than 95% when assessed via a correlation with phasing ambiguities accounted for. Here, we describe the challenges, summarize the results and provide a first critical assessment of the entries

Prospects of eLISA for Detecting Galactic Binary Black Holes Similar to GW150914

OpenAIRE

Seto, Naoki

2016-01-01

We discuss the prospects of eLISA for detecting gravitational waves (GWs) from Galactic binary black holes (BBHs) similar to GW150914. For a comoving merger rate that is consistent with current observation, eLISA is likely to identify at least one BBH with a sufficient signal-to-noise ratio. In addition, eLISA has a potential to measure the eccentricity of the BBH as small as $e\\sim 0.02$, corresponding to the residual value $e\\sim 10^{-6}$ at 10Hz. Therefore, eLISA could provide us with a cr...

Mona Lisa, lesbiahvid ja seksilaulud / Kaivo Kopli

Index Scriptorium Estoniae

Kopli, Kaivo

2003-01-01

Ameerika Teaduse Edendamise Assotsiatsiooni (AAA) konverentsil esitatud uusimatest teadusuuringutest. Artiklid: Mona Lisa naeratuse saladus paljastatud ; Lesbilised Jaapani makaagid seljatavad Darwini ; Linnud õpivad uusi laule uue partneri leidmiseks

Low-Frequency Gravitational-Wave Science with eLISA/ NGO

Science.gov (United States)

Amaro-Seoane, Pau; Aoudia, Sofiane; Babak, Stanislav; Binetruy, Pierre; Berti, Emanuele; Bohe, Alejandro; Caprini, Chiara; Colpi, Monica; Cornish, Neil J.; Danzmann, Karsten;

LISA Pathfinder test-mass charging during galactic cosmic-ray flux short-term variations

Science.gov (United States)

Grimani, C.; Fabi, M.; Lobo, A.; Mateos, I.; Telloni, D.

2015-02-01

Metal free-floating test masses aboard the future interferometers devoted to gravitational wave detection in space are charged by galactic and solar cosmic rays with energies \\gt 100 MeV/n. This process represents one of the main sources of noise in the lowest frequency band (\\lt 10-3 Hz) of these experiments. We study here the charging of the LISA Pathfinder (LISA-PF) gold-platinum test masses due to galactic cosmic-ray (GCR) protons and helium nuclei with the Fluka Monte Carlo toolkit. Projections of the energy spectra of GCRs during the LISA-PF operations in 2015 are considered. This work was carried out on the basis of the solar activity level and solar polarity epoch expected for LISA-PF. The effects of GCR short-term variations are evaluated here for the first time. Classical Forbush decreases, GCR variations induced by the Sun rotation, and fluctuations in the LISA-PF frequency bandwidth are discussed.

Observing a Gravitational Wave Background With Lisa

National Research Council Canada - National Science Library

Tinto, M; Armstrong, J; Estabrook, F

2000-01-01

... formation of several observables. All are independent of lasers and frequency standard phase fluctuations, but have different couplings to gravitational waves and to the various LISA instrumental noises...

Beyond the Required LISA Free-Fall Performance: New LISA Pathfinder Results down to 20 μ Hz

Science.gov (United States)

Armano, M.; Audley, H.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Castelli, E.; Cavalleri, A.; Cesarini, A.; Cruise, A. M.; Danzmann, K.; de Deus Silva, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E. D.; Freschi, M.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Grzymisch, J.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C. J.; Lobo, J. A.; Lloro, I.; Liu, L.; López-Zaragoza, J. P.; Maarschalkerweerd, R.; Mance, D.; Meshksar, N.; Martín, V.; Martin-Polo, L.; Martino, J.; Martin-Porqueras, F.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mendes, L.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Ramos-Castro, J.; Reiche, J.; Robertson, D. I.; Rivas, F.; Russano, G.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J. I.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Wass, P. J.; Weber, W. J.; Wissel, L.; Wittchen, A.; Zweifel, P.

2018-02-01

In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20 μ Hz . The Letter presents the measured differential acceleration noise figure, which is at (1.74 ±0.01 ) fm s-2/√{Hz } above 2 mHz and (6 ±1 ) ×10 fm s-2/√{Hz } at 20 μ Hz , and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency.

EDITORIAL: Proceedings of the 7th International LISA Symposium, Barcelona, Spain, 16-20 June 2008 Proceedings of the 7th International LISA Symposium, Barcelona, Spain, 16-20 June 2008

Science.gov (United States)

Lobo, Alberto; Sopuerta, Carlos F.

2009-05-01

In June 2006 the LISA International Science Team (LIST) accepted the bid presented by the Institut d'Estudis Espacials de Catalunya (IEEC) to host the 7th International LISA Symposium. This was during its 11th meeting at the University of Maryland, just before the 6th edition of the symposium started at NASA's Goddard Space Flight Center. The 7th International LISA Symposium took place in the city of Barcelona, Spain, 16-20 June, 2008, in the premises of CosmoCaixa, a modern science museum located in the hills near Tibidabo. Almost 240 delegates registered for the event, a record breaking figure compared to previous editions of the symposium. Many of the most renowned world experts in LISA, gravitational wave science, and astronomy, as well as engineers, attended LISA #7 and produced state of the art presentations, while everybody benefited from the opportunity to have live discussions during the week in a friendly environment. The programme included 31 invited plenary lectures in the mornings, and eight parallel sessions in the afternoons. These were classified into seven major areas of research: LISA Technology, LISA PathFinder, LISA PathFinder Data Analysis, LISA Data Analysis, Gravitational Wave Sources, Cosmology and Fundamental Physics with LISA and Other Gravitational Wave Detectors. Abstracts for 138 communications were received, from which a selection was made by the session convenors which would fit time constraints. Up to 63 posters completed the scientific programme. More details on the programme, including some of the talks, can be found at the symposium website:http://www.ice.cat/research/LISA_Symposium. There was, however, a remarkable add-on: Professor Clifford Will delivered a startling presentation to the general public, who completely filled the Auditori—the main conference room, 320 seats—and were invited to ask questions to the speaker who boldly guided them through the daunting world of Black Holes, Waves of Gravity, and other Warped Ideas

Doing Science with eLISA: Astrophysics and Cosmology in the Millihertz Regime

Science.gov (United States)

Amaro, Seoane, Pau; Aoudia, Sofiane; Babak, Stanislav; Binetruy, Pierre; Berti, Amanuele; Bohe, Alejandro; Caprini, Chiara; Colpi, Monica; Cornish, Neil J.; Danzmann, Karsten;

Ausência de desgaste agudo da musculatura esquelética e cardíaca em atletas amadores de triathlon

Directory of Open Access Journals (Sweden)

Maria Fátima Glaner

2009-01-01

Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n1p37 A creatina quinase (CK e a sua fração músculo-cérebro (CK MB podem estar ligadas a danos no tecido muscular e cardíaco, respectivamente, como conseqüência de exercícios prolongados e intensos. O estudo teve como objetivo verificar se a variação aguda da CK e da CK MB reflete algum risco de desgaste acentuado para a musculatura esquelética e cardíaca, de atletas amadores, após o Ironman 70.3. A amostra foi composta por dez atletas voluntários, masculinos (idade= 34,0 ± 9,2 anos. A amostra de sangue venoso (2mL foi coletada antes e após o Ironman 70.3. Os voluntários completaram o percurso em 5h20min à 6h. A CK e a CK MB foram analisadas pelo método enzimático, usando reagentes Wienner lab, em um espectrofotômetro automático (Targa bt 3000. O teste não paramétrico de Wilcoxon indicou diferenças significativas (p <0,05 entre os períodos pré e pós competição nas variáveis estudadas. Os valores médios foram: CK= 112,23 ± 34,9U/L e 458,0 ± 204,9U/L (Δ%= 418,2; CK MB= 7,4 ± 2,6U/L e 10,8 ± 3,9U/L (Δ%= 153,3, respectivamente, para pré e pós. A variação relativa da CK MB em relação à CK, pré (6,9% e pós competição (2,5%, indicou que este não é um fator tão preocupante durante o exercício extenuante de longa duração, como o Ironman 70.3. Conclui-se que a concentração aguda de CK, logo após o término do exercício extenuante de longa duração, indicou desgaste da musculatura esquelética, porém considerado normal para atletas. Quanto à CK MB, o desgaste da musculatura cardíaca foi inexistente.

LISA Pathfinder: Optical Metrology System monitoring during operations

Science.gov (United States)

Audley, Heather E.; LISA Pathfinder Collaboration

2017-05-01

The LISA Pathfinder (LPF) mission has demonstrated excellent performance. In addition to having surpassed the main mission goals, data has been collected from the various subsystems throughout the duration of the mission. This data is a valuable resource, both for a more complete understanding of the LPF satellite and the differential acceleration measurements, as well as for the design of the future Laser Interferometer Space Antenna (LISA) mission. Initial analysis of the Optical Metrology System (OMS) data was performed as part of daily system monitoring, and more in-depth analyses are ongoing. This contribution presents an overview of these activities along with an introduction to the OMS.

LISA data analysis using Markov chain Monte Carlo methods

International Nuclear Information System (INIS)

Cornish, Neil J.; Crowder, Jeff

2005-01-01

The Laser Interferometer Space Antenna (LISA) is expected to simultaneously detect many thousands of low-frequency gravitational wave signals. This presents a data analysis challenge that is very different to the one encountered in ground based gravitational wave astronomy. LISA data analysis requires the identification of individual signals from a data stream containing an unknown number of overlapping signals. Because of the signal overlaps, a global fit to all the signals has to be performed in order to avoid biasing the solution. However, performing such a global fit requires the exploration of an enormous parameter space with a dimension upwards of 50 000. Markov Chain Monte Carlo (MCMC) methods offer a very promising solution to the LISA data analysis problem. MCMC algorithms are able to efficiently explore large parameter spaces, simultaneously providing parameter estimates, error analysis, and even model selection. Here we present the first application of MCMC methods to simulated LISA data and demonstrate the great potential of the MCMC approach. Our implementation uses a generalized F-statistic to evaluate the likelihoods, and simulated annealing to speed convergence of the Markov chains. As a final step we supercool the chains to extract maximum likelihood estimates, and estimates of the Bayes factors for competing models. We find that the MCMC approach is able to correctly identify the number of signals present, extract the source parameters, and return error estimates consistent with Fisher information matrix predictions

Multi-Messenger Astronomy: White Dwarf Binaries, LISA and GAIA

Science.gov (United States)

Bueno, Michael; Breivik, Katelyn; Larson, Shane L.

2017-01-01

The discovery of gravitational waves has ushered in a new era in astronomy. The low-frequency band covered by the future LISA detector provides unprecedented opportunities for multi-messenger astronomy. With the Global Astrometric Interferometer for Astrophysics (GAIA) mission, we expect to discover about 1,000 eclipsing binary systems composed of a WD and a main sequence star - a sizeable increase from the approximately 34 currently known binaries of this type. In advance of the first GAIA data release and the launch of LISA within the next decade, we used the Binary Stellar Evolution (BSE) code simulate the evolution of White Dwarf Binaries (WDB) in a fixed galaxy population of about 196,000 sources. Our goal is to assess the detectability of a WDB by LISA and GAIA using the parameters from our population synthesis, we calculate GW strength h, and apparent GAIA magnitude G. We can then use a scale factor to make a prediction of how many multi- messenger sources we expect to be detectable by both LISA and GAIA in a galaxy the size of the Milky Way. We create binaries 10 times to ensure randomness in distance assignment and average our results. We then determined whether or not astronomical chirp is the difference between the total chirp and the GW chirp. With Astronomical chirp and simulations of mass transfer and tides, we can gather more information about the internal astrophysics of stars in ultra-compact binary systems.

Sensitivity and parameter-estimation precision for alternate LISA configurations

International Nuclear Information System (INIS)

Vallisneri, Michele; Crowder, Jeff; Tinto, Massimo

2008-01-01

We describe a simple framework to assess the LISA scientific performance (more specifically, its sensitivity and expected parameter-estimation precision for prescribed gravitational-wave signals) under the assumption of failure of one or two inter-spacecraft laser measurements (links) and of one to four intra-spacecraft laser measurements. We apply the framework to the simple case of measuring the LISA sensitivity to monochromatic circular binaries, and the LISA parameter-estimation precision for the gravitational-wave polarization angle of these systems. Compared to the six-link baseline configuration, the five-link case is characterized by a small loss in signal-to-noise ratio (SNR) in the high-frequency section of the LISA band; the four-link case shows a reduction by a factor of √2 at low frequencies, and by up to ∼2 at high frequencies. The uncertainty in the estimate of polarization, as computed in the Fisher-matrix formalism, also worsens when moving from six to five, and then to four links: this can be explained by the reduced SNR available in those configurations (except for observations shorter than three months, where five and six links do better than four even with the same SNR). In addition, we prove (for generic signals) that the SNR and Fisher matrix are invariant with respect to the choice of a basis of TDI observables; rather, they depend only on which inter-spacecraft and intra-spacecraft measurements are available

Weak-light phase locking for LISA

International Nuclear Information System (INIS)

McNamara, Paul W

2005-01-01

The long armlengths of the LISA interferometer, and the finite aperture of the telescope, lead to an optical power attenuation of ∼10 -10 of the transmitted to received light. Simple reflection at the end of the arm is therefore not an optimum interferometric design. Instead, a local laser is offset phase locked to the weak incoming beam, transferring the phase information of the incoming to the outgoing light. This paper reports on an experiment to characterize a weak-light phase-locking scheme suitable for LISA in which a diode-pumped, Nd:YAG, non-planar ring oscillator (NPRO) is offset phase locked to a low-power (13 pW) frequency stabilized master NPRO. Preliminary results of the relative phase noise of the slave laser shows shot noise limited performance above 0.4 Hz. Excess noise is observed at lower frequencies, most probably due to thermal effects in the optical arrangement and phase-sensing electronics

Detection of Micrometeoroids with LISA Pathfinder

Science.gov (United States)

Thorpe, Ira; Littenberg, Tyson; Janchez, Diego; Baker, John; The LISA Pathfinder Team Team

2017-01-01

The LISA Pathfinder mission (LPF), a joint ESA/NASA technology demonstration mission currently operating at the Sun-Earth L1 point, contains the most precise accelerometry system ever flown. Analysis suggests that LPF should have sufficient sensitivity to detect impacts of small micrometeoroids and dust through their transfer of momentum to the spacecraft. Moreover, LPF's ability to fully resolve both the linear and angular momentum transfer in three dimensions allows a magnitude, direction, and location to be estimated for each impact. We present preliminary results from a systematic search of the LISA Pathfinder data for such impacts and discuss the prospects for using these and future results to inform models of the formation and evolution of dust populations in the inner solar system. These models have wide applicability to both pure and applied space science, ranging from the physics of planet formation and dynamics of minor Solar System bodies to estimates of the micrometeorite hazard for future spacecraft. 2017 NASA Science Innovation Fund.

LISA Sources in Milky Way Globular Clusters

Science.gov (United States)

Kremer, Kyle; Chatterjee, Sourav; Breivik, Katelyn; Rodriguez, Carl L.; Larson, Shane L.; Rasio, Frederic A.

2018-05-01

We explore the formation of double-compact-object binaries in Milky Way (MW) globular clusters (GCs) that may be detectable by the Laser Interferometer Space Antenna (LISA). We use a set of 137 fully evolved GC models that, overall, effectively match the properties of the observed GCs in the MW. We estimate that, in total, the MW GCs contain ˜21 sources that will be detectable by LISA. These detectable sources contain all combinations of black hole (BH), neutron star, and white dwarf components. We predict ˜7 of these sources will be BH-BH binaries. Furthermore, we show that some of these BH-BH binaries can have signal-to-noise ratios large enough to be detectable at the distance of the Andromeda galaxy or even the Virgo cluster.

LISA extreme-mass-ratio inspiral events as probes of the black hole mass function

International Nuclear Information System (INIS)

Gair, Jonathan R.; Tang, Christopher; Volonteri, Marta

2010-01-01

One of the sources of gravitational waves for the proposed space-based gravitational wave detector, the Laser Interferometer Space Antenna (LISA), are the inspirals of compact objects into supermassive black holes in the centers of galaxies--extreme-mass-ratio inspirals (EMRIs). Using LISA observations, we will be able to measure the parameters of each EMRI system detected to very high precision. However, the statistics of the set of EMRI events observed by LISA will be more important in constraining astrophysical models than extremely precise measurements for individual systems. The black holes to which LISA is most sensitive are in a mass range that is difficult to probe using other techniques, so LISA provides an almost unique window onto these objects. In this paper we explore, using Bayesian techniques, the constraints that LISA EMRI observations can place on the mass function of black holes at low redshift. We describe a general framework for approaching inference of this type--using multiple observations in combination to constrain a parametrized source population. Assuming that the scaling of the EMRI rate with the black-hole mass is known and taking a black-hole distribution given by a simple power law, dn/dlnM=A 0 (M/M * ) α 0 , we find that LISA could measure the parameters to a precision of Δ(lnA 0 )∼0.08, and Δ(α 0 )∼0.03 for a reference model that predicts ∼1000 events. Even with as few as 10 events, LISA should constrain the slope to a precision ∼0.3, which is the current level of observational uncertainty in the low-mass slope of the black-hole mass function. We also consider a model in which A 0 and α 0 evolve with redshift, but find that EMRI observations alone do not have much power to probe such an evolution.

LISA Pathfinder: An important first step towards a space-based gravitational wave observatory

Science.gov (United States)

Thorpe, James

2017-08-01

ESA's LISA Pathfinder mission was launched on Dec 3rd, 2015 and completed earlier this Summer. During this relatively short mission, Pathfinder at its two science payloads, Europe's LISA Technology Package and NASA's Disturbance Reduction System, demonstrated several techniques and technologies that enable development of a future space-based gravitational wave observatory. Most notably, Pathfinder demonstrated that the technique of drag-free flight could be utilized to place a test mass in near-perfect free-fall, with residual accelerations at the femto-g level in the milliHertz band. Additionally, technologies such as precision bonded optical structures for metrology, micropropulsion systems, and non-contact charge control, were successfully tested, retiring risk for LISA. In this talk, I will present an overview of Pathfinder's results to date and some perspective on how this success will be leveraged into realizing LISA.

Study of test-mass charging process in the LISA missions due to diffuse γ-rays

International Nuclear Information System (INIS)

Finetti, N; Scrimaglio, R; Grimani, C; Fabi, M

2009-01-01

Gravitational inertial sensors will be placed on board the Laser Interferometer Space Antenna (LISA) and aboard its precursor mission LISA Pathfinder (LISA-PF) in order to detect low frequency gravitational waves in space. Free-floating test-masses (Au 7 Pt 3 cubes) will be housed in inertial sensors for detecting possible laser signal variations induced by gravitational waves. Charging of the LISA test-masses due to exposure of the spacecraft to cosmic radiation and energetic solar particles will affect operation of gravitational inertial sensors. In this paper we report on the role of diffuse γ-rays in charging the LISA and LISA-PF test-masses with respect to protons and helium nuclei. The diffuse γ-ray flux in the Galaxy has been interpolated taking into account the outcomes of recent calculations. A comparison with γ-ray observations gathered by different experiments (COMPTEL and EGRET, Milagro, Whipple, HEGRA, TIBET) has been carried out. Simulations of the test-mass charging process have been performed by means of the FLUKA2006.3b package. Monte Carlo simulations of the interaction of cosmic particles with the LISA spacecraft indicate that the diffuse γ-ray contribution to the average steady-state test-mass charging rate and to the single-sided power spectrum of the charge rate noise is marginal with respect to that due to galactic cosmic-rays.

Micrometeorite Science with LISA Pathfinder

Science.gov (United States)

Pagane, Nicole; Thorpe, James Ira; Littenberg, Tyson; Littenberg, Tyson; Baker, John; Slutsky, Jacob; Hourihane, Sophie; LISA Pathfinder Team

2018-01-01

The primary objective of LISA Pathfinder (LPF) was to demonstrate drag-free control of test masses—along with the technology necessary to maintain the inertial motion—that LISA (Laser Interferometer Space Antenna) would later utilize as a space-based gravitational wave observatory. Due to the precise interferometry used during the mission, LPF could be employed as an accelerometer and used to detect micrometeorite impacts while in orbit about the Sun-Earth Lagrange Point L1. To infer micrometeorite impacts, the flight data was processed for event reconstruction to determine external acceleration of LPF; impact parameters were then estimated through a Markov-Chain Monte-Carlo (MCMC) tool via Bayesian analysis by fitting delta functions in the acceleration domain. As impact candidates were collected, a catalog of event data was curated with the reconstructed estimated parameters, among which were impact sky localizations that were later rotated into more intuitive reference frames. To infer the results of this dust modeling technique, current micrometeorite models were compared to the impact data. In the final reference frame common to the available micrometeorite models, the reconstructed impacts appear to cluster at (±90°, 0°)—where impacts prograde in this longitude-latitude frame were at (-90°, 0°), retrograde were (90°, 0°), and the sun was centered at the origin. The two available models used for comparison were of the Jupiter-family comets (JFC) and Halley-type comets (HTC), which clustered primarily around (±90°, 0°) and (0°, ±20°) respectively. This suggests that the JFC population seems to account for the majority of the impacts detected by LPF. The models’ expected rates given localization and velocity are currently being compared to the reconstructed data to further characterize the micrometeorite populations at L1. We will present our current analysis of this data set and discuss possibilities of extending such an analysis for LISA.

UV-LED-based charge control for LISA

Science.gov (United States)

Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Ciani, Giacomo; Mueller, Guido; Conklin, John

2014-03-01

The test masses inside the LISA gravitational reference sensors (GRS) must maintain almost pure geodesic motion for gravitational waves to be successfully detected. The residual accelerations have to stay below 3fm/s2/rtHz at all frequencies between 0.1 and 3 mHz. One of the well known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electro-magnetic fields. The LISA pathfinder (LPF) will use Hg-discharge lamps emitting mostly around 253 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. UV-LEDs have a lower mass, a better power efficiency, and are smaller than their Hg counterparts. Furthermore, the latest generation produces light at 240 nm, with energy well above the work function of pure gold. I will describe a preliminary design for effective charge control through photoelectric effect by using these LEDs. The effectiveness of this method is verified by taking Quantum Efficiency (QE) measurements which relate the number of electrons emitted to the number of photons incident on the Au test mass surface. This presentation addresses our initial results and future plans which includes implementation and testing in the UF torsion pendulum and space-qualification in a small satellite mission which will launch in the summer of 2014, through a collaboration with Stanford, KACST, and NASA Ames Research Center.

The Mock LISA Data Challenges: from challenge 3 to challenge 4

International Nuclear Information System (INIS)

Babak, Stanislav; Petiteau, Antoine; Robinson, Emma L; Baker, John G; McWilliams, Sean T; Arnaud, Keith A; Benacquista, Matthew J; Cornish, Neil J; Adams, Matt; Larson, Shane L; Mandel, Ilya; Porter, Edward K; Vallisneri, Michele; Cutler, Curt; Vecchio, Alberto; Blaut, Arkadiusz; Bridges, Michael; Feroz, Farhan; Cohen, Michael; Gair, Jonathan R.

2010-01-01

The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in April 2008, which demonstrated the positive recovery of signals from chirping galactic binaries, from spinning supermassive-black-hole binaries (with optimal SNRs between ∼10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with Ω gw (f) ∼ 10 -11 , slightly below the LISA instrument noise.

The Mock LISA Data Challenges: from challenge 3 to challenge 4

Energy Technology Data Exchange (ETDEWEB)

Babak, Stanislav; Petiteau, Antoine; Robinson, Emma L [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, D-14476 Golm bei Potsdam (Germany); Baker, John G; McWilliams, Sean T; Arnaud, Keith A [Gravitational Astrophysics Laboratory, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771 (United States); Benacquista, Matthew J [Center for Gravitational Wave Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States); Cornish, Neil J; Adams, Matt [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Larson, Shane L [Department of Physics, Utah State University, Logan, UT 84322 (United States); Mandel, Ilya [Department of Physics and Astronomy, Northwestern University, Evanston, IL (United States); Porter, Edward K [APC, UMR 7164, University Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, 75025 Paris Cedex 13 (France); Vallisneri, Michele; Cutler, Curt [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Vecchio, Alberto [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B152TT (United Kingdom); Blaut, Arkadiusz [Institute of Theoretical Physics, University of Wroclaw, Wroclaw (Poland); Bridges, Michael; Feroz, Farhan [Astrophysics Group, Cavendish Laboratory, University of Cambridge, Cambridge CB30HE (United Kingdom); Cohen, Michael [Theoretical Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Gair, Jonathan R., E-mail: Michele.Vallisneri@jpl.nasa.go [Institute of Astronomy, University of Cambridge, Cambridge CB30HA (United Kingdom)

2010-04-21

The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in April 2008, which demonstrated the positive recovery of signals from chirping galactic binaries, from spinning supermassive-black-hole binaries (with optimal SNRs between approx10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with OMEGA{sub gw}(f) approx 10{sup -11}, slightly below the LISA instrument noise.

Probing the Universe with Gravitational Waves: the Laser Interferometer Space Antenna (LISA)

NARCIS (Netherlands)

Prince, T.A.; Binetruy, P.; Centrella, J.; Finn, L.; Hogan, C.; Nelemans, G.A.; Phinney, S.

2007-01-01

- For the LISA International Science Team: LISA is a joint NASA/ESA space mission designed to measure gravitational waves in the band from 0.1 mHz to 0.1 Hz, a band that is richly populated by strong sources of gravitational waves. Signals will come from a wider range of sources: massive black holes

Interpolation of the magnetic field at the test masses in eLISA

International Nuclear Information System (INIS)

Mateos, I; Díaz-Aguiló, M; Ramos-Castro, J; García-Berro, E; Lobo, A

2015-01-01

A feasible design for a magnetic diagnostics subsystem for eLISA will be based on that of its precursor mission, LISA Pathfinder. Previous experience indicates that magnetic field estimation at the positions of the test masses has certain complications. This is due to two reasons. The first is that magnetometers usually back-act due to their measurement principles (i.e., they also create their own magnetic fields), while the second is that the sensors selected for LISA Pathfinder have a large size, which conflicts with space resolution and with the possibility of having a sufficient number of them to properly map the magnetic field around the test masses. However, high-sensitivity and small-sized sensors that significantly mitigate the two aforementioned limitations exist, and have been proposed to overcome these problems. Thus, these sensors will be likely selected for the magnetic diagnostics subsystem of eLISA. Here we perform a quantitative analysis of the new magnetic subsystem, as it is currently conceived, and assess the feasibility of selecting these sensors in the final configuration of the magnetic diagnostic subsystem. (paper)

Modulation of LISA free-fall orbits due to the Earth-Moon system

Energy Technology Data Exchange (ETDEWEB)

Cerdonio, Massimo; Marzari, Francesco [Department of Physics, University of Padova and INFN Padova, via Marzolo 8, I-35131 Padova (Italy); De Marchi, Fabrizio [Department of Physics, University of Trento and INFN Trento, I-38100 Povo (Trento) (Italy); De Pietri, Roberto [Department of Physics, University of Parma and INFN Parma I-43100 Parma (Italy); Jetzer, Philippe [Institute of Theoretical Physics, University of Zuerich, Winterhurerstrasse 190, 8057 Zuerich (Switzerland); Mazzolo, Giulio [Max Planck Institut fuer Gravitationsphysik, Callinstrasse 38, 30167 Hannover (Germany); Ortolan, Antonello [INFN Laboratori Nazionali di Legnaro, Viale dell' Universita 35020 Legnaro (Padova) (Italy); Sereno, Mauro, E-mail: fdemarchi@science.unitn.i [Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

2010-08-21

We calculate the effect of the Earth-Moon (EM) system on the free-fall motion of LISA test masses. We show that the periodic gravitational pulling of the EM system induces a resonance with fundamental frequency 1 yr{sup -1} and a series of periodic perturbations with frequencies equal to integer harmonics of the synodic month ({approx_equal} 3.92 x 10{sup -7} Hz). We then evaluate the effects of these perturbations (up to the 6th harmonics) on the relative motions between each test mass couple, finding that they range between 3 mm and 10 pm for the 2nd and 6th harmonic, respectively. If we take the LISA sensitivity curve, as extrapolated down to 10{sup -6} Hz in Bender (2003 Class. Quantum Grav. 20 301-10), we obtain that a few harmonics of the EM system can be detected in the Doppler data collected by the LISA space mission. This suggests that the EM system gravitational near field could provide an additional crosscheck to the calibration of LISA, as extended to such low frequencies.

Modulation of LISA free-fall orbits due to the Earth-Moon system

International Nuclear Information System (INIS)

Cerdonio, Massimo; Marzari, Francesco; De Marchi, Fabrizio; De Pietri, Roberto; Jetzer, Philippe; Mazzolo, Giulio; Ortolan, Antonello; Sereno, Mauro

2010-01-01

We calculate the effect of the Earth-Moon (EM) system on the free-fall motion of LISA test masses. We show that the periodic gravitational pulling of the EM system induces a resonance with fundamental frequency 1 yr -1 and a series of periodic perturbations with frequencies equal to integer harmonics of the synodic month (≅ 3.92 x 10 -7 Hz). We then evaluate the effects of these perturbations (up to the 6th harmonics) on the relative motions between each test mass couple, finding that they range between 3 mm and 10 pm for the 2nd and 6th harmonic, respectively. If we take the LISA sensitivity curve, as extrapolated down to 10 -6 Hz in Bender (2003 Class. Quantum Grav. 20 301-10), we obtain that a few harmonics of the EM system can be detected in the Doppler data collected by the LISA space mission. This suggests that the EM system gravitational near field could provide an additional crosscheck to the calibration of LISA, as extended to such low frequencies.

Annual modulation of the galactic binary confusion noise background and LISA data analysis

International Nuclear Information System (INIS)

Seto, Naoki

2004-01-01

We study the anisotropies of the galactic confusion noise background and its effects on LISA data analysis. LISA has two data streams of gravitational wave signals relevant for the low frequency regime. Because of the anisotropies of the background, the matrix for their confusion noises has off-diagonal components and depends strongly on the orientation of the detector plane. We find that the sky-averaged confusion noise level √(S(f)) could change by a factor of 2 in 3 months and would be minimum when the orbital position of LISA is around either the spring or autumn equinox

Sensing and actuation system for the University of Florida Torsion Pendulum for LISA

Science.gov (United States)

Chilton, Andrew; Shelley, Ryan; Olatunde, Taiwo; Ciani, Giacomo; Conklin, John; Mueller, Guido

2014-03-01

Space-based gravitational wave detectors like LISA are a necessity for understanding the low-frequency portion of the gravitational universe. They use test masses (TMs) which are separated by Gm and are in free fall inside their respective spacecraft. Their relative distance is monitored with laser interferometry at the pm/rtHz level in the LISA band, ranging from 0.1 to 100 mHz. Each TM is enclosed in a housing that provides isolation, capacitive sensing, and electrostatic actuation capabilities. The electronics must both be sensitive at the 1 nm/rtHz level and not induce residual acceleration noise above the requirement for LISA Pathfinder (3*10-15 m/sec2Hz1/2at 3 mHz). Testing and developing this technology is one of the roles of the University of Florida Torsion Pendulum, the only US testbed for LISA-like gravitational reference sensor technology. Our implementation of the sensing system functions by biasing our hollow LISA-like TMs with a 100 kHz sine wave and coupling a pair surrounding electrodes as capacitors to a pair of preamps and a differential amplifier; all other processing is done digitally. Here we report on the design of, implementation of, and preliminary results from the UF Torsion Pendulum.

LISA as a dark energy probe

International Nuclear Information System (INIS)

Arun, K G; Mishra, Chandra Kant; Iyer, B R; Sinha, Siddhartha; Van Den Broeck, Chris; Sathyaprakash, B S

2009-01-01

Recently, it has been shown that the inclusion of higher signal harmonics in the inspiral signals of binary supermassive black holes (SMBH) leads to dramatic improvements in the parameter estimation with Laser Interferometer Space Antenna (LISA). In particular, the angular resolution becomes good enough to identify the host galaxy or galaxy cluster, in which case the redshift can be determined by electromagnetic means. The gravitational wave signal also provides the luminosity distance with high accuracy, and the relationship between this and the redshift depends sensitively on the cosmological parameters, such as the equation-of-state parameter w = p DE /ρ DE of dark energy. Using binary SMBH events at z < 1 with appropriate masses and orientations, one would be able to constrain w to within a few per cent. We show that, if the measured sky location is folded into the error analysis, the uncertainty on w goes down by an additional factor of 2-3, leaving weak lensing as the only limiting factor in using LISA as a dark energy probe.

Estudo bibliométrico do descritor “Ergonomia” na base LISA

Directory of Open Access Journals (Sweden)

Eliana Maria dos Santos Bahia

2011-03-01

Full Text Available Objetivo: O estudo analisa a produção científica sobre ergonomia utilizando a base de dados Library and Information Science Abstracts (LISA. A base de dados LISA, iniciada em 1969, mantém sua cobertura temática na área de Biblioteconomia e Ciência da Informação.Método: No estudo utilizou-se o método da bibliometria aplicada para verificar a produção científica indexada.Resultados: Entre os resultados da busca de termos indexados na base de dados LISA, encontraram-se 503 artigos com o termo “Ergonomic”; 352 artigos, com a expressão “Design”; 111 artigos com o descritor “Systems”; 110 artigos com o termo “Work”; e , 98 artigos com o termo “Evaluation”. Dentre os 34 títulos de periódicos, 4 títulos cobrem 79% dos artigos que tratam sobre Ergonomia na base LISA. Os demais 30 títulos de periódicos cobrem 21% dos artigos indexados sob essa temática.Conclusões: O presente estudo bibliométrico oferece possibilita um panorama de como a ergonomia é percebida na área da Biblioteconomia e Ciência da Informação.

Dual-Cylinder Laser Reference Cavities for LISA Project

Data.gov (United States)

National Aeronautics and Space Administration — "Summary: The Laser Interferometer Space Antenna (LISA) mission is under consideration by NASA and ESA as a joint mission to study gravitational wave signals from a...

The Mona Lisa of modern science.

Science.gov (United States)

Kemp, Martin

2003-01-23

No molecule in the history of science has reached the iconic status of the double helix of DNA. Its image has been imprinted on all aspects of society, from science, art, music, cinema, architecture and advertising. This review of the Mona Lisa of science examines the evolution of its form at the hands of both science and art.

From LPF to eLISA: new approach in payload software

Science.gov (United States)

Gesa, Ll.; Martin, V.; Conchillo, A.; Ortega, J. A.; Mateos, I.; Torrents, A.; Lopez-Zaragoza, J. P.; Rivas, F.; Lloro, I.; Nofrarias, M.; Sopuerta, CF.

2017-05-01

eLISA will be the first observatory in space to explore the Gravitational Universe. It will gather revolutionary information about the dark universe. This implies a robust and reliable embedded control software and hardware working together. With the lessons learnt with the LISA Pathfinder payload software as baseline, we will introduce in this short article the key concepts and new approaches that our group is working on in terms of software: multiprocessor, self-modifying-code strategies, 100% hardware and software monitoring, embedded scripting, Time and Space Partition among others.

Performance of arm locking in LISA

International Nuclear Information System (INIS)

McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A.

2009-01-01

For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. D 78, 082001 (2008)] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time

Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves

CERN Document Server

Bartolo, Nicola; Domcke, Valerie; Figueroa, Daniel G.; Garcia-Bellido, Juan; Guzzetti, Maria Chiara; Liguori, Michele; Matarrese, Sabino; Peloso, Marco; Petiteau, Antoine; Ricciardone, Angelo; Sakellariadou, Mairi; Sorbo, Lorenzo; Tasinato, Gianmassimo

2016-01-01

We investigate the potential for the LISA space-based interferometer to detect the stochastic gravitational wave background produced from different mechanisms during inflation. Focusing on well-motivated scenarios, we study the resulting contributions from particle production during inflation, inflationary spectator fields with varying speed of sound, effective field theories of inflation with specific patterns of symmetry breaking and models leading to the formation of primordial black holes. The projected sensitivities of LISA are used in a model-independent way for various detector designs and configurations. We demonstrate that LISA is able to probe these well-motivated inflationary scenarios beyond the irreducible vacuum tensor modes expected from any inflationary background.

Science with the space-based interferometer LISA. IV: probing inflation with gravitational waves

International Nuclear Information System (INIS)

Bartolo, Nicola; Guzzetti, Maria Chiara; Liguori, Michele; Matarrese, Sabino

2016-01-01

We investigate the potential for the LISA space-based interferometer to detect the stochastic gravitational wave background produced from different mechanisms during inflation. Focusing on well-motivated scenarios, we study the resulting contributions from particle production during inflation, inflationary spectator fields with varying speed of sound, effective field theories of inflation with specific patterns of symmetry breaking and models leading to the formation of primordial black holes. The projected sensitivities of LISA are used in a model-independent way for various detector designs and configurations. We demonstrate that LISA is able to probe these well-motivated inflationary scenarios beyond the irreducible vacuum tensor modes expected from any inflationary background.

Alternative opto-mechanical architectures for the LISA instrument

Energy Technology Data Exchange (ETDEWEB)

Weise, Dennis R; Marenaci, Pierangelo; Weimer, Peter; Schulte, Hans Reiner; Gath, Peter; Johann, Ulrich, E-mail: dennis.weise@astrium.eads.ne [EADS Astrium GmbH, Claude-Dornier-Str., 88039 Friedrichshafen (Germany)

2009-03-01

As part of the on-going LISA Mission Formulation study under ESA contract, EADS Astrium has recently suggested and investigated a variety of novel LISA payload architectures utilizing so-called 'In-Field Pointing' for accommodation of seasonal constellation dynamics. Here, the annual variation in the angle between the interferometer arms of roughly +-1 deg. is compensated by steering the lines of sight of the individual telescopes with a small actuated mirror located in an intermediate pupil plane inside the telescopes. This introduces a certain flexibility for the overall payload configuration and allows for very compact designs. In particular, it enables a 'single active proof mass' mode with a true cold redundancy between a nominal and a backup GRS system on board each spacecraft, and thus enhances mission robustness.

LISA Sources in Milky Way Globular Clusters.

Science.gov (United States)

Kremer, Kyle; Chatterjee, Sourav; Breivik, Katelyn; Rodriguez, Carl L; Larson, Shane L; Rasio, Frederic A

2018-05-11

We explore the formation of double-compact-object binaries in Milky Way (MW) globular clusters (GCs) that may be detectable by the Laser Interferometer Space Antenna (LISA). We use a set of 137 fully evolved GC models that, overall, effectively match the properties of the observed GCs in the MW. We estimate that, in total, the MW GCs contain ∼21 sources that will be detectable by LISA. These detectable sources contain all combinations of black hole (BH), neutron star, and white dwarf components. We predict ∼7 of these sources will be BH-BH binaries. Furthermore, we show that some of these BH-BH binaries can have signal-to-noise ratios large enough to be detectable at the distance of the Andromeda galaxy or even the Virgo cluster.

Reducing tilt-to-length coupling for the LISA test mass interferometer

Science.gov (United States)

Tröbs, M.; Schuster, S.; Lieser, M.; Zwetz, M.; Chwalla, M.; Danzmann, K.; Fernández Barránco, G.; Fitzsimons, E. D.; Gerberding, O.; Heinzel, G.; Killow, C. J.; Perreur-Lloyd, M.; Robertson, D. I.; Schwarze, T. S.; Wanner, G.; Ward, H.

2018-05-01

Objects sensed by laser interferometers are usually not stable in position or orientation. This angular instability can lead to a coupling of angular tilt to apparent longitudinal displacement—tilt-to-length coupling (TTL). In LISA this is a potential noise source for both the test mass interferometer and the long-arm interferometer. We have experimentally investigated TTL coupling in a setup representative for the LISA test mass interferometer and used this system to characterise two different imaging systems (a two-lens design and a four-lens design) both designed to minimise TTL coupling. We show that both imaging systems meet the LISA requirement of  ±25 μm rad‑1 for interfering beams with relative angles of up to  ±300 μrad. Furthermore, we found a dependency of the TTL coupling on beam properties such as the waist size and location, which we characterised both theoretically and experimentally.

PREFACE: Proceedings of the 7th International LISA Symposium, Barcelona, Spain, 16-20 June 2008

Science.gov (United States)

Lobo, Alberto; Sopuerta, Carlos F.

2009-07-01

In June 2006 the LISA International Science Team (LIST) accepted the bid presented by the Institut d'Estudis Espacials de Catalunya (IEEC) to host the 7th International LISA Symposium. This was during its 11th meeting at the University of Maryland, just before the 6th edition of the Symposium started in NASA's Goddard Space Flight Center. The 7th International LISA Symposium took place at the city of Barcelona, Spain, from 16-20 June 2008, in the premises of CosmoCaixa, a modern Science Museum located in the hills near Tibidabo. Almost 240 delegates registered for the event, a record breaking figure compared to previous editions of the Symposium. Many of the most renowned world experts in LISA, Gravitational Wave Science, and Astronomy, as well as Engineers, attended LISA 7 and produced state-of-the-art presentations, while everybody benefited from the opportunity to have live discussions during the week in a friendly environment. The programme included 31 invited plenary lectures in the mornings, and 8 parallel sessions in the afternoons. These were classified into 7 major areas of research: LISA Technology, LISA PathFinder, LISA PathFinder Data Analysis, LISA Data Analysis, Gravitational Wave sources, Cosmology and Fundamental Physics with LISA and Other Gravitational Wave Detectors. 138 abstracts for communications were received, of which a selection was made by the session convenors which would fit time constraints. Up to 63 posters completed the scientific programme. More details on the programme, including some of the talks, can be found at the Symposium website: http://www.ice.cat/research/LISA_Symposium. There was however a remarkable add-on: Professor Clifford Will delivered a startling presentation to the general public, who completely filled the Auditori—the main Conference Room, 320 seats—and were invited to ask questions to the speaker who had boldly guided them through the daunting world of Black Holes, Waves of Gravity, and other Warped Ideas of

eLISA eccentricity measurements as tracers of binary black hole formation

OpenAIRE

Nishizawa, Atsushi; Berti, Emanuele; Klein, Antoine; Sesana, Alberto

2016-01-01

Up to hundreds of black hole binaries individually resolvable by eLISA will coalesce in the Advanced LIGO/Virgo band within ten years, allowing for multi-band gravitational wave observations. Binaries formed via dynamical interactions in dense star clusters are expected to have eccentricities $e_0\\sim 10^{-3}$-$10^{-1}$ at the frequencies $f_0=10^{-2}$ Hz where eLISA is most sensitive, while binaries formed in the field should have negligible eccentricity in both frequency bands. We estimate ...

Nested sampling as a tool for LISA data analysis

International Nuclear Information System (INIS)

Gair, Jonathan R; Feroz, Farhan; Graff, Philip; Hobson, Michael P; Babak, Stanislav; Petiteau, Antoine; Porter, Edward K

2010-01-01

Nested sampling is a technique for efficiently computing the probability of a data set under a particular hypothesis, also called the Bayesian Evidence or Marginal Likelihood, and for evaluating the posterior. MULTINEST is a multi-modal nested sampling algorithm which has been designed to efficiently explore and characterize posterior probability surfaces containing multiple secondary solutions. We have applied the MULTINEST algorithm to a number of problems in gravitational wave data analysis. In this article, we describe the algorithm and present results for several applications of the algorithm to analysis of mock LISA data. We summarise recently published results for a test case in which we searched for two non-spinning black hole binary merger signals in simulated LISA data. We also describe results obtained with MULTINEST in the most recent round of the Mock LISA Data Challenge (MLDC), in which the algorithm was used to search for and characterise both spinning supermassive black hole binary inspirals and bursts from cosmic string cusps. In all these applications, the algorithm found the correct number of signals and efficiently recovered the posterior probability distribution. Moreover, in most cases the waveform corresponding to the best a-posteriori parameters had an overlap in excess of 99% with the true signal.

Nested sampling as a tool for LISA data analysis

Energy Technology Data Exchange (ETDEWEB)

Gair, Jonathan R [Institute of Astronomy, Madingley Road, CB3 0HA, Cambridge (United Kingdom); Feroz, Farhan; Graff, Philip; Hobson, Michael P [Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Babak, Stanislav; Petiteau, Antoine [Max-Planck-Institut fuer Gravitationsphysik, Am Muehlenberg 1, 14476, Potsdam (Germany); Porter, Edward K, E-mail: jgair@ast.cam.ac.u [APC, UMR 7164, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)

2010-05-01

Nested sampling is a technique for efficiently computing the probability of a data set under a particular hypothesis, also called the Bayesian Evidence or Marginal Likelihood, and for evaluating the posterior. MULTINEST is a multi-modal nested sampling algorithm which has been designed to efficiently explore and characterize posterior probability surfaces containing multiple secondary solutions. We have applied the MULTINEST algorithm to a number of problems in gravitational wave data analysis. In this article, we describe the algorithm and present results for several applications of the algorithm to analysis of mock LISA data. We summarise recently published results for a test case in which we searched for two non-spinning black hole binary merger signals in simulated LISA data. We also describe results obtained with MULTINEST in the most recent round of the Mock LISA Data Challenge (MLDC), in which the algorithm was used to search for and characterise both spinning supermassive black hole binary inspirals and bursts from cosmic string cusps. In all these applications, the algorithm found the correct number of signals and efficiently recovered the posterior probability distribution. Moreover, in most cases the waveform corresponding to the best a-posteriori parameters had an overlap in excess of 99% with the true signal.

Verification of time-delay interferometry techniques using the University of Florida LISA interferometry simulator

Energy Technology Data Exchange (ETDEWEB)

Mitryk, Shawn J; Wand, Vinzenz; Mueller, Guido, E-mail: smitryk@phys.ufl.ed, E-mail: mueller@phys.ufl.ed [Department of Physics, University of Florida, PO Box 118440, Gainesville, FL 32611-8440 (United States)

2010-04-21

Laser Interferometer Space Antenna (LISA) is a cooperative NASA/ESA mission proposed to directly measure gravitational waves (GW) in the frequency range from 30 muHz to 1 Hz with an optimal strain sensitivity of 10{sup -21}/sq root(Hz) at 3 mHz. LISA will utilize a modified Michelson interferometer to measure length changes of 40 pm/sq root(Hz) between drag-free proof masses located on three separate spacecraft (SC) separated by a distance of 5 Gm. The University of Florida has developed a hardware-in-the-loop simulator of the LISA constellation to verify the laser noise cancellation technique known as time-delay interferometry (TDI). We replicate the frequency stabilization of the laser on the local SC and the phase-locking of the lasers on the far SC. The laser photodetector beatnotes are electronically delayed, Doppler shifted and applied with a mock GW signal to simulate the laser link between the SC. The beatnotes are also measured with a LISA-like phasemeter and the data are used to extract the laser phase and residual phase-lock loop noise in post-processing through TDI. This uncovers the GW modulation signal buried under the laser noise. The results are then compared to the requirements defined by the LISA science collaboration.

Report on the second Mock LISA data challenge

International Nuclear Information System (INIS)

Babak, Stanislav; Porter, Edward K; Baker, John G; Benacquista, Matthew J; Cornish, Neil J; Littenberg, Tyson B; Crowder, Jeff; Cutler, Curt; Vallisneri, Michele; Larson, Shane L; Vecchio, Alberto; Auger, Gerard; Barack, Leor; Blaut, Arkadiusz; Bloomer, Ed; Clark, James; Brown, Duncan A; Fairhurst, Stephen; Christensen, Nelson; Gair, Jonathan R

2008-01-01

The Mock LISA data challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of several data sets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants are asked to analyze the data sets and report the maximum information about the source parameters. The challenges are being released in rounds of increasing complexity and realism: here we present the results of Challenge 2, issued in Jan 2007, which successfully demonstrated the recovery of signals from nonspinning supermassive-black-hole binaries with optimal SNRs between ∼10 and 2000, from ∼20 000 overlapping galactic white-dwarf binaries (among a realistically distributed population of 26 million), and from the extreme-mass-ratio inspirals of compact objects into central galactic black holes with optimal SNRs ∼100

Massive black-hole binary inspirals: results from the LISA parameter estimation taskforce

International Nuclear Information System (INIS)

Arun, K G; Babak, Stas; Porter, Edward K; Sintes, Alicia M; Berti, Emanuele; Cutler, Curt; Cornish, Neil; Gair, Jonathan; Hughes, Scott A; Lang, Ryan N; Iyer, Bala R; Sinha, Siddhartha; Mandel, Ilya; Sathyaprakash, Bangalore S; Van Den Broeck, Chris; Trias, Miquel; Volonteri, Marta

2009-01-01

The LISA Parameter Estimation Taskforce was formed in September 2007 to provide the LISA Project with vetted codes, source distribution models and results related to parameter estimation. The Taskforce's goal is to be able to quickly calculate the impact of any mission design changes on LISA's science capabilities, based on reasonable estimates of the distribution of astrophysical sources in the universe. This paper describes our Taskforce's work on massive black-hole binaries (MBHBs). Given present uncertainties in the formation history of MBHBs, we adopt four different population models, based on (i) whether the initial black-hole seeds are small or large and (ii) whether accretion is efficient or inefficient at spinning up the holes. We compare four largely independent codes for calculating LISA's parameter-estimation capabilities. All codes are based on the Fisher-matrix approximation, but in the past they used somewhat different signal models, source parametrizations and noise curves. We show that once these differences are removed, the four codes give results in extremely close agreement with each other. Using a code that includes both spin precession and higher harmonics in the gravitational-wave signal, we carry out Monte Carlo simulations and determine the number of events that can be detected and accurately localized in our four population models.

Description of charging/discharging processes of the LISA sensors

International Nuclear Information System (INIS)

Sumner, Tim; Araujo, Henrique; Davidge, David; Howard, Alex; Lee, Chris; Rochester, Geoff; Shaul, Diana; Wass, Peter

2004-01-01

The next generation of gravitational experiments in space is likely to use completely isolated proof-masses. For example, LISA uses proof-masses as mirrors in interferometers for gravitational wave astronomy (Bender et al 1998 Pre-phase A report MPG-233 pp 1-191) and STEP uses proof-masses in Earth orbit for an equivalence principle test (Sumner et al 2003 at press). Nongravitational forces will act on these proof-masses if they become charged, through the action of cosmic rays and solar flare particles for example. This paper examines the consequences of proof-mass charging for LISA, and presents results from using GEANT4 to assess the charging processes. Finally, there is a brief discussion of a means of controlling the charge down to an acceptable level

Linfangiectasia intestinal e linfangite lipogranulomatosa em dois caninos Intestinal lymphangiectasia with lipogranulomatous lymphangitis in two dogs

Directory of Open Access Journals (Sweden)

Marcia Regina da Silva Ilha

2004-08-01

Full Text Available Relatam-se dois casos adicionais de linfangiectasia intestinal e linfangite lipogranulomatosa (LI/LL em caninos. Sinais clínicos manifestados pelos animais afetados incluíam diarréia crônica, perda de peso, dificuldade respiratória e anorexia. À necropsia, a mucosa do intestino delgado apresentava-se pálida, macia e com aspecto aveludado mais evidente conferido por vilosidades esbranquiçadas, alongadas, mais visíveis e densamente aglomeradas formando tufos. Na borda mesentérica da serosa intestinal, havia lesões arredondadas, lisas, elevadas, firmes, brancacentas, de 1-3mm de diâmetro, que também acompanhavam os vasos linfáticos mesentéricos que estavam salientes e distendidos por material espesso e esbranquiçado. Carcaças em mau estado corporal, edema subcutâneo e efusões cavitárias também foram observados. Microscopicamente, havia acentuada ectasia dos vasos quilíferos das vilosidades intestinais associada à presença de lipogranulomas intramurais ou mesentéricos. No presente estudo, o diagnóstico definitivo de LI/LL foi realizado através do exame histológico do intestino delgado e mesentério associado. Desconhece-se a prevalência dessa enfermidade em caninos no Brasil.Two additional cases of intestinal lymphangiectasia with lipogranulomatous lymphangitis (IL/LL in dogs are described. Clinical signs in the affected animals included chronic diarrhea, weight loss, labored breathing and anorexia. At necropsy, the mucosa of the small intestine was pale, soft and had numerous white, elongated villi clumped together in tufts giving the surface of the intestinal mucosa a pronounced velvety pattern. White, round, smooth, raised, firm, pinpoint lesions, varying from 1-3mm of diameter, were observed on the serosal surface of the small intestine on its mesenteric border and along prominent mesenteric lymphatic vessels distended with thick, chalky white paste. Thin carcasses. subcutaneous edema and cavitary effusions were also

Data analysis and source modelling for LISA

International Nuclear Information System (INIS)

Shang, Yu

2014-01-01

The gravitational waves are one of the most important predictions in general relativity. Besides of the directly proof of the existence of GWs, there are already several ground based detectors (such as LIGO, GEO, etc) and the planed future space mission (such as: LISA) which are aim to detect the GWs directly. GW contain a large amount of information of its source, extracting these information can help us dig out the physical property of the source, even open a new window for understanding the Universe. Hence, GW data analysis will be a challenging task in seeking the GWs. In this thesis, I present two works about the data analysis for LISA. In the first work, we introduce an extended multimodal genetic algorithm which utilizes the properties of the signal and the detector response function to analyze the data from the third round of mock LISA data challenge. We have found all five sources present in the data and recovered the coalescence time, chirp mass, mass ratio and sky location with reasonable accuracy. As for the orbital angular momentum and two spins of the Black Holes, we have found a large number of widely separated modes in the parameter space with similar maximum likelihood values. The performance of this method is comparable, if not better, to already existing algorithms. In the second work, we introduce an new phenomenological waveform model for the extreme mass ratio inspiral system. This waveform consists of a set of harmonics with constant amplitude and slowly evolving phase which we decompose in a Taylor series. We use these phenomenological templates to detect the signal in the simulated data, and then, assuming a particular EMRI model, estimate the physical parameters of the binary with high precision. The results show that our phenomenological waveform is very feasible in the data analysis of EMRI signal.

Constraining stellar binary black hole formation scenarios with eLISA eccentricity measurements

OpenAIRE

Nishizawa, Atsushi; Sesana, Alberto; Berti, Emanuele; Klein, Antoine

2016-01-01

A space-based interferometer such as eLISA could observe few to few thousands progenitors of black hole binaries (BHBs) similar to those recently detected by Advanced LIGO. Gravitational radiation circularizes the orbit during inspiral, but some BHBs retain a measurable eccentricity at the low frequencies where eLISA is most sensitive. The eccentricity of a BHB carries precious information about its formation channel: BHBs formed in the field, in globular clusters, or close to a massive black...

LISA technologies in new light: exploring alternatives for charge management and optical bench construction

Science.gov (United States)

Ciani, Giacomo; Chilton, Andrew; Olatunde, Taiwo; Apple, Stephen; Conklin, John W.; Mueller, Guido

2015-08-01

A LISA-like gravitational wave observatory is the choice candidate for ESA's L3 large mission scheduled to launch in 2034. The LISA Test Package (LTP) mission will launch later this year and test many critical technologies needed for such an observatory, among which are picometer interferometry in space and UV charge management of the Test Mass (TM). The design of these subsystems has been frozen many years ago during the final formulation of the LTP mission; since then, the LISA mission concept has evolved and new technologies have become available, making it possible to re-think the way these subsystem are implemented. With the final formulation of the L3 mission still years in the future and the LTP results expected in about one year, now is an ideal time look for areas of possible improvement and explore alternative implementations that can enhance performance, reduce costs or mitigate risks.Recently developed UV LED are lighter, cheaper and more powerful than traditional mercury lamps; in addition, their fast response time can be used to implement AC discharge techniques that can save even more space and power, and provide a more precise control of the charge.The most recent iteration of the mission baseline design allows for eliminating some of the optical components initially deemed essential; paired with the use of polarization multiplexing, this permits a redesign of the optical bench that simplifies the layout and enables a modular approach to machining and assembly, thus reducing the risks and costs associated with the current monolithic design without compromising the picometer stability of the optical path.Leveraging on extensive previous experience with LISA interferometry and the availability of a torsion pendulum-based LISA test-bed, the University of Florida LISA group is working at developing, demonstrating and optimizing both these technologies. I will describe the most recent advancements and results.

Optical testbed for the LISA phasemeter

Science.gov (United States)

Schwarze, T. S.; Fernández Barranco, G.; Penkert, D.; Gerberding, O.; Heinzel, G.; Danzmann, K.

2016-05-01

The planned spaceborne gravitational wave detector LISA will allow the detection of gravitational waves at frequencies between 0.1 mHz and 1 Hz. A breadboard model for the metrology system aka the phasemeter was developed in the scope of an ESA technology development project by a collaboration between the Albert Einstein Institute, the Technical University of Denmark and the Danish industry partner Axcon Aps. It in particular provides the electronic readout of the main interferometer phases besides auxiliary functions. These include clock noise transfer, ADC pilot tone correction, inter-satellite ranging and data transfer. Besides in LISA, the phasemeter can also be applied in future satellite geodesy missions. Here we show the planning and advances in the implementation of an optical testbed for the full metrology chain. It is based on an ultra-stable hexagonal optical bench. This bench allows the generation of three unequal heterodyne beatnotes with a zero phase combination, thus providing the possibility to probe the phase readout for non-linearities in an optical three signal test. Additionally, the utilization of three independent phasemeters will allow the testing of the auxiliary functions. Once working, components can individually be replaced with flight-qualified hardware in this setup.

Optical testbed for the LISA phasemeter

International Nuclear Information System (INIS)

Schwarze, T S; Fernández Barranco, G; Penkert, D; Gerberding, O; Heinzel, G; Danzmann, K

2016-01-01

The planned spaceborne gravitational wave detector LISA will allow the detection of gravitational waves at frequencies between 0.1 mHz and 1 Hz. A breadboard model for the metrology system aka the phasemeter was developed in the scope of an ESA technology development project by a collaboration between the Albert Einstein Institute, the Technical University of Denmark and the Danish industry partner Axcon Aps. It in particular provides the electronic readout of the main interferometer phases besides auxiliary functions. These include clock noise transfer, ADC pilot tone correction, inter-satellite ranging and data transfer. Besides in LISA, the phasemeter can also be applied in future satellite geodesy missions. Here we show the planning and advances in the implementation of an optical testbed for the full metrology chain. It is based on an ultra-stable hexagonal optical bench. This bench allows the generation of three unequal heterodyne beatnotes with a zero phase combination, thus providing the possibility to probe the phase readout for non-linearities in an optical three signal test. Additionally, the utilization of three independent phasemeters will allow the testing of the auxiliary functions. Once working, components can individually be replaced with flight-qualified hardware in this setup. (paper)

Recent progress at NASA in LISA formulation and technology development

International Nuclear Information System (INIS)

Stebbins, R T

2008-01-01

Over the last year, the NASA half of the joint LISA project has focused its efforts on responding to a major review, and advancing the formulation and technology development of the mission. The NAS/NRC Beyond Einstein program assessment review will be described, including the outcome. The basis of the LISA science requirements has changed from detection determined by integrated signal-to-noise ratio to observation determined by uncertainty in the estimation of astrophysical source parameters. The NASA team has further defined the spacecraft bus design, participated in many design trade studies and advanced the requirements flow down and the associated current best estimates of performance. Recent progress in technology development is also summarized

The first mock data challenge for LISA Pathfinder

Energy Technology Data Exchange (ETDEWEB)

Monsky, A; Hewitson, M; Wanner, G; Nofrarias, M; Diepholz, I; Danzmann, K [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik und Universitaet Hannover, 30167 Hannover (Germany); Ferraioli, L; Hueller, M; Cavalleri, A; Ciani, G; Dolesi, R [Dipartimento di Fisica, Universita di Trento and INFN, Gruppo Collegato di Trento, 38050 Povo, Trento (Italy); Grynagier, A [Institut fuer Flugmechanik und Flugregelung, 70569 Stuttgart (Germany); Armano, M [European Space Agency, ESAC, Villanueva de la Canada, 28692 Madrid (Spain); Benedetti, M [Dipartimento di Ingegneria dei Materiali e Tecnologie Industriali, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Bogenstahl, J [Department of Physics and Astronomy, University of Glasgow, Glasgow (United Kingdom); Bortoluzzi, D; Bosetti, P; Cristofolini, I [Dipartimento di Ingegneria Meccanica e Strutturale, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Brandt, N [Astrium GmbH, 88039 Friedrichshafen (Germany); Cruise, M, E-mail: anneke.monsky@aei.mpg.d [Department of Physics and Astronomy, University of Birmingham, Birmingham (United Kingdom)

2009-05-07

The data analysis of the LISA Technology Package (LTP) will comprise a series of discrete experiments, each focusing on a particular noise measurement or characterization of the instrument in various operating modes. Each of these experiments must be analysed and planned in advance of the mission because the results of a given experiment will have an impact on those that follow. As such, a series of mock data challenges (MDCs) will be developed and carried out with the aim of preparing the analysis tools and optimizing the various planned analyses. The first of these MDCs (MDC1) is a simplified treatment of the dynamics along the axis joining the two test masses onboard LISA Pathfinder. The validation of the dynamical model by predicting the spectra of the interferometer output data is shown, a prediction for the data analysis is calculated and, finally, several simulated interferometer data sets are analysed and calibrated to equivalent out-of-loop test mass acceleration.

Advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) Small Spacecraft System

Science.gov (United States)

Lockett, Tiffany Russell; Martinez, Armando; Boyd, Darren; SanSouice, Michael; Farmer, Brandon; Schneider, Todd; Laue, Greg; Fabisinski, Leo; Johnson, Les; Carr, John A.

2015-01-01

This paper describes recent advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) currently being developed at NASA's Marshall Space Flight Center. The LISA-T array comprises a launch stowed, orbit deployed structure on which thin-film photovoltaic (PV) and antenna devices are embedded. The system provides significant electrical power generation at low weights, high stowage efficiency, and without the need for solar tracking. Leveraging high-volume terrestrial-market PVs also gives the potential for lower array costs. LISA-T is addressing the power starvation epidemic currently seen by many small-scale satellites while also enabling the application of deployable antenna arrays. Herein, an overview of the system and its applications are presented alongside sub-system development progress and environmental testing plans.

LISA detection of massive black hole binaries: imprint of seed populations and extreme recoils

International Nuclear Information System (INIS)

Sesana, A; Volonteri, M; Haardt, F

2009-01-01

All the physical processes involved in the formation, merging and accretion history of massive black holes along the hierarchical build-up of cosmic structures are likely to leave an imprint on the gravitational waves detectable by future space-borne missions, such as LISA. We report here the results of recent studies, carried out by means of dedicated simulations of black hole build-up, aiming at understanding the impact on LISA observations of two ingredients that are crucial in every massive black hole formation scenario, namely: (i) the nature and abundance of the first black hole seeds and (ii) the large gravitational recoils following the merger of highly spinning black holes. We predict LISA detection rates spanning two orders of magnitude, in the range 3-300 events per year, depending on the detail of the assumed massive black hole seed model. On the other hand, large recoil velocities do not dramatically compromise the efficiency of LISA observations. The number of detections may drop substantially (by ∼60%), in scenarios characterized by abundant light seeds, but if seeds are already massive and/or relatively rare, the detection rate is basically unaffected.

In-orbit performance of the LISA Pathfinder drag-free and attitude control system

Science.gov (United States)

Schleicher, A.; Ziegler, T.; Schubert, R.; Brandt, N.; Bergner, P.; Johann, U.; Fichter, W.; Grzymisch, J.

2018-04-01

LISA Pathfinder is a technology demonstrator mission that was funded by the European Space Agency and that was launched on December 3, 2015. LISA Pathfinder has been conducting experiments to demonstrate key technologies for the gravitational wave observatory LISA in its operational orbit at the L1 Lagrange point of the Earth-Sun system until final switch off on July 18, 2017. These key technologies include the inertial sensors, the optical metrology system, a set of µ-propulsion cold gas thrusters and in particular the high performance drag-free and attitude control system (DFACS) that controls the spacecraft in 15 degrees of freedom during its science phase. The main goal of the DFACS is to shield the two test masses inside the inertial sensors from all external disturbances to achieve a residual differential acceleration between the two test masses of less than 3 × 10-14 m/s2/√Hz over the frequency bandwidth of 1-30 mHz. This paper focuses on two important aspects of the DFACS that has been in use on LISA Pathfinder: the DFACS Accelerometer mode and the main DFACS Science mode. The Accelerometer mode is used to capture the test masses after release into free flight from the mechanical grabbing mechanism. The main DFACS Science Mode is used for the actual drag-free science operation. The DFACS control system has very strong interfaces with the LISA Technology Package payload which is a key aspect to master the design, development, and analysis of the DFACS. Linear as well as non-linear control methods are applied. The paper provides pre-flight predictions for the performance of both control modes and compares these predictions to the performance that is currently achieved in-orbit. Some results are also discussed for the mode transitions up to science mode, but the focus of the paper is on the Accelerometer mode performance and on the performance of the Science mode in steady state. Based on the achieved results, some lessons learnt are formulated to extend

LISA Pathfinder: OPD loop characterisation

Science.gov (United States)

Born, Michael; LPF Collaboration

2017-05-01

The optical metrology system (OMS) of the LISA Pathfinder mission is measuring the distance between two free-floating test masses with unprecedented precision. One of the four OMS heterodyne interferometers reads out the phase difference between the reference and the measurement laser beam. This phase from the reference interferometer is common to all other longitudinal interferometer read outs and therefore subtracted. In addition, the phase is fed back via the digital optical pathlength difference (OPD) control loop to keep it close to zero. Here, we analyse the loop parameters and compare them to on-ground measurement results.

Sky Localization of Complete Inspiral-Merger-Ringdown Signals for Nonspinning Black Hole Binaries with LISA

Science.gov (United States)

McWilliams, Sean T.; Lang, Ryan N.; Baker, John G.; Thorpe, James Ira

2011-01-01

We investigate the capability of LISA to measure the sky position of equal-mass, nonspinning black hole binaries, including for the first time the entire inspiral-merger-ringdown signal, the effect of the LISA orbits, and the complete three-channel LISA response. For an ensemble of systems near the peak of LISA's sensitivity band, with total rest mass of 2 x l0(exp 6) Stellar Mass at a redshift of z = 1 with random orientations and sky positions, we find median sky localization errors of approximately approx. 3 arcminutes. This is comparable to the field of view of powerful electromagnetic telescopes, such as the James Webb Space Telescope, that could be used to search for electromagnetic signals associated with merging black holes. We investigate the way in which parameter errors decrease with measurement time, focusing specifically on the additional information provided during the merger-ringdown segment of the signal. We find that this information improves all parameter estimates directly, rather than through diminishing correlations with any subset of well-determined parameters.

Science with the space-based interferometer eLISA. II. Gravitational waves from cosmological phase transitions

International Nuclear Information System (INIS)

Caprini, Chiara; Hindmarsh, Mark; Helsinki Univ.; Huber, Stephan

2016-04-01

We investigate the potential for the eLISA space-based interferometer to detect the stochastic gravitational wave background produced by strong first-order cosmological phase transitions. We discuss the resulting contributions from bubble collisions, magnetohydrodynamic turbulence, and sound waves to the stochastic background, and estimate the total corresponding signal predicted in gravitational waves. The projected sensitivity of eLISA to cosmological phase transitions is computed in a model-independent way for various detector designs and configurations. By applying these results to several specific models, we demonstrate that eLISA is able to probe many well-motivated scenarios beyond the Standard Model of particle physics predicting strong first-order cosmological phase transitions in the early Universe.

Demonstration of AC and DC charge control for the LISA test masses

Science.gov (United States)

Olatunde, Taiwo Janet

2018-01-01

Taiwo Olatunde, Stephen Apple, Andrew Chilton, Samantha Parry, Peter Wass, Guido Mueller, John W. Conklin The residual test mass acceleration in LISA must be below 3 fm/s2/√Hz at all frequencies between 0.1 and 3 mHz. Test mass charge coupled with stray electrical potentials and external electromagnetic fields is a well-known source of acceleration noise. LISA Pathfinder uses Hg lamps emitting mostly around 254 nm to discharge the test masses via photoemission, but a future LISA mission launched around 2030 will likely replace the lamps with newer UV LEDs with lower mass, better power efficiency, smaller size and higher bandwidth. This presentation will discuss charge control demonstrated on the torsion pendulum in AC and DC modes at the University of Florida using latest generation UV LEDs producing light at 240 nm with energy above the work function of pure Au. Initial results of Au quantum efficiency measurements (number of emitted electrons per incident photons) which is critical for bi-polar charge control will also be presented.

Construction of an optical test-bed for eLISA

International Nuclear Information System (INIS)

Lieser, Maike; Isleif, K-S; Schuster, S; Tröbs, M; Veith, S; Heinzel, G; Danzmann, K; Fitzsimons, E; Killow, C; Perreur-Lloyd, M; Robertson, D; Ward, H

2016-01-01

In the planned eLISA mission a key part of the system is the optical bench that holds the interferometers for reading out the inter-spacecraft distance and the test mass position. We report on ongoing technology development for the eLISA optical system like the back-link between the optical benches and the science interferometer where the local beam is interfered with the received beam from the distant spacecraft. The focus will be on a setup to investigate the tilt-to-pathlength coupling in the science interferometer. To test the science interferometer in the lab a second bench providing a laser beam and a reference interferometer is needed. We present a setup with two ultra-stable low expansion glass benches and bonded optics. To suppress the tilt-to-pathlength coupling to the required level (few μm/rad) imaging optics are placed in front of the interferometer photo diodes. (paper)

77 FR 56647 - Lisa Jean Sharp: Debarment Order

Science.gov (United States)

2012-09-13

... Act (the FD&C Act) permanently debarring Lisa Jean Sharp from providing services in any capacity to a...&C Act. Ms. Sharp was given notice of the proposed permanent debarment and an opportunity to request... drug product under the FD&C Act. The factual basis for this conviction is as follows: Ms. Sharp was the...

T.D Lee and Lisa Randall visit ATLAS

CERN Multimedia

Pauline Gagnon

Professor Tsung-Dao Lee, who received the Nobel Prize for Physics in 1957 for postulating that parity is not conserved in weak interactions, visited the ATLAS detector this month. He is seen here in the company of Peter Jenni, spokesperson for ATLAS. T.D. Lee is still very active at over 80, pursuing his theory work to this day. Professor Lisa Randall from Harvard University, the well-known theorist behind the Randall-Sundrum theory for extra dimensions, was also part of the group visiting the ATLAS detector. She is seen here with Fabiola Gianotti, deputy spokesperson for ATLAS. Lisa Randall's two initial papers have been quoted both more than 2500 times, making her the most cited theoretical physicist in the world in the last five years as of last autumn - a total of about 10,000 citations! One wonders here if Peter is pointing to a CP-violating graviton spotted in the ATLAS cavern... From left to right: Fabiola Gianotti, Gustaaf Brooijmans, convener of the ATLAS Exotics physics gro...

Towards an improved magnetic diagnostic system for LISA

International Nuclear Information System (INIS)

Mateos, I; Lobo, A; Sanjuan, J; Ramos-Castro, J; Nofrarias, M

2009-01-01

The current design, and material implementation of the magnetic field sensing in the LISA Technology Package (LTP) on board LISA Pathfinder (LPF), is based on a set of 4 high-precision 3-axis fluxgate magnetometers. In order to avoid magnetic disturbances on the LTP proof masses (TM 's), originated by the sensors themselves, these are placed somewhat far from the TM's, which results in partial field information losses. We are currently investigating alternative magnetic sensing techniques, based on AMR (Anisotropic Magnetoresistive) devices. These are much smaller in size than fluxgates, therefore a more numerous array can be thought of for flight. In addition, there is a chance that they may be attached closer to the TM's, thereby enhancing magnetic field sensing spacial resolution. Several issues need to be addressed, such as real sensitivity (including electronics noise) and set/reset trigger procedures. A brief overview about the stability of the magnetic fields and gradients generated in the LTP by means of the coil will also be given. This paper show the latest results of our research.

The end-to-end testbed of the optical metrology system on-board LISA Pathfinder

Energy Technology Data Exchange (ETDEWEB)

Steier, F; Cervantes, F Guzman; Marin, A F GarcIa; Heinzel, G; Danzmann, K [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut) and Universitaet Hannover (Germany); Gerardi, D, E-mail: frank.steier@aei.mpg.d [EADS Astrium Satellites GmbH, Friedrichshafen (Germany)

2009-05-07

LISA Pathfinder is a technology demonstration mission for the Laser Interferometer Space Antenna (LISA). The main experiment on-board LISA Pathfinder is the so-called LISA Technology Package (LTP) which has the aim to measure the differential acceleration between two free-falling test masses with an accuracy of 3 x 10{sup -14} ms{sup -2} Hz{sup -1/2} between 1 mHz and 30 mHz. This measurement is performed interferometrically by the optical metrology system (OMS) on-board LISA Pathfinder. In this paper, we present the development of an experimental end-to-end testbed of the entire OMS. It includes the interferometer and its sub-units, the interferometer backend which is a phasemeter and the processing of the phasemeter output data. Furthermore, three-axes piezo-actuated mirrors are used instead of the free-falling test masses for the characterization of the dynamic behaviour of the system and some parts of the drag-free and attitude control system (DFACS) which controls the test masses and the satellite. The end-to-end testbed includes all parts of the LTP that can reasonably be tested on earth without free-falling test masses. At its present status it consists mainly of breadboard components. Some of those have already been replaced by engineering models of the LTP experiment. In the next steps, further engineering and flight models will also be inserted in this testbed and tested against well-characterized breadboard components. The presented testbed is an important reference for the unit tests and can also be used for validation of the on-board experiment during the mission.

Efeitos do carbonato de lodenafila na consolidaÃÃo de fraturas da diÃfise femoral de Ratos tratados com haste intramedular

OpenAIRE

Gisele FaÃanha Diogenes Teixeira

2010-01-01

O objetivo do estudo foi verificar os efeitos do carbonato de lodenafil no processo de consolidaÃÃo Ãssea nos fÃmures de ratos reduzidos com fio de Kirshner. Os fatores vasculares sÃo extremamente importantes para a formaÃÃo do calo Ãsseo. O carbonato de lodenafil causa efeitos vasodilatadores, pertence ao grupo dos inibidores da fosfodiesterase seletiva para o tipo 5 (PDE5), enzima que hidrolisa monofosfato de guanosina cÃclico (GMPc). O GMPc induz o relaxamento da musculatura lisa, sendo ut...

HEALTHY AND PATHOLOGICAL CHANGES OF MYOMETRIUM: PREGNANT MYOMETRIUM, UTERINE FIBROIDS AND LEIOMYOSARCOMA. Cambios normales y patológicos del miometrio: miometrio del embarazo, fibrosis uterina y leiomiosarcoma

OpenAIRE

Pasquapina Ciarmela; Soriful Islam; Pasquale Lamanna; Andrea Tranquilli; Mario Castellucci

2016-01-01

El miometrio, la pared muscular del útero, puede modificar su misma masa y las propiedades celulares en el embarazo y también en los tumores como el leiomioma y el leiomiosarcoma. El leiomioma, dicho también fibroma, es un tumor benigno del útero y se considera como  una de las causas más frecuentes de infertilità en el período reproductivo femenino. El leiomiosarcoma, en cambio, es un tumor maligno y agresivo de la musculatura lisa uterina. La presente revisión discute las características ge...

Stellar binary black holes in the LISA band: a new class of standard sirens

Science.gov (United States)

Del Pozzo, Walter; Sesana, Alberto; Klein, Antoine

2018-04-01

The recent Advanced LIGO detections of coalescing black hole binaries (BHBs) imply a large population of such systems emitting at milli-Hz frequencies, accessible to the Laser Interferometer Space Antenna (LISA). We show that these systems provide a new class of cosmological standard sirens. Direct LISA luminosity distance - Dl - measurements, combined with the inhomogeneous redshift - z - distribution of possible host galaxies provide an effective way to populate the Dl-z diagram at z arm-length, respectively.

In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors

International Nuclear Information System (INIS)

Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

2015-01-01

Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations. (paper)

Cosmological Backgrounds of Gravitational Waves and eLISA

OpenAIRE

Dufaux, Jean-Francois

2012-01-01

We review cosmological backgrounds of gravitational waves with a particular attention to the scientific potential of the eLISA/NGO mission. After an overview of cosmological backgrounds and detectors, we consider different cosmological sources that could lead to an observable signal. We then study the backgrounds produced by first-order phase transitions and networks of cosmic strings, assessing the prospects for their detection.

Algebraic approach to time-delay data analysis for LISA

International Nuclear Information System (INIS)

Dhurandhar, S.V.; Nayak, K. Rajesh; Vinet, J.-Y.

2002-01-01

Cancellation of laser frequency noise in interferometers is crucial for attaining the requisite sensitivity of the triangular three-spacecraft LISA configuration. Raw laser noise is several orders of magnitude above the other noises and thus it is essential to bring it down to the level of other noises such as shot, acceleration, etc. Since it is impossible to maintain equal distances between spacecrafts, laser noise cancellation must be achieved by appropriately combining the six beams with appropriate time delays. It has been shown in several recent papers that such combinations are possible. In this paper, we present a rigorous and systematic formalism based on algebraic geometrical methods involving computational commutative algebra, which generates in principle all the data combinations canceling the laser frequency noise. The relevant data combinations form the first module of syzygies, as it is called in the literature of algebraic geometry. The module is over a polynomial ring in three variables, the three variables corresponding to the three time delays around the LISA triangle. Specifically, we list several sets of generators for the module whose linear combinations with polynomial coefficients generate the entire module. We find that this formalism can also be extended in a straightforward way to cancel Doppler shifts due to optical bench motions. The two modules are in fact isomorphic. We use our formalism to obtain the transfer functions for the six beams and for the generators. We specifically investigate monochromatic gravitational wave sources in the LISA band and carry out the maximization over linear combinations of the generators of the signal-to-noise ratios with the frequency and source direction angles as parameters

LTP - LISA technology package: Development challenges of a spaceborne fundamental physics experiment

International Nuclear Information System (INIS)

Gerndt, R

2009-01-01

The LISA Technology Package (LTP) is the main payload onboard the LISA Pathfinder Spacecraft. The LTP Instrument together with the Drag-Free Attitude Control System (DFACS) and the respective LTP and DFACS operational software forms the LTP Experiment. It is completed by the FEEPs of the LPF spacecraft that are controlled by DFACS in order to control the spacecraft's attitude along with the experiment's needs. This article concentrates on aspects of the Industrial development of the LTP Instrument items and on essential performance issues of LTP. Examples of investigations on specific issue will highlight the kind of special problems to be solved for LTP in close cooperation with the Scientific Community.

LISA: A performance assessment code for geological repositories of radioactive waste

International Nuclear Information System (INIS)

Bertozzi, G.; Saltelli, A.

1985-01-01

LISA, developed at JRC-Ispra, is a statistical code, which calculates the radiation exposures and risks associated with radionuclide releases from geological repositories of nuclear waste. The assessment methodology is described briefly. It requires that a number of probabilistic components be quantified and introduced in the analysis; the results are thus expressed in terms of risk. The subjective judgment of experts may be necessary to quantify the probabilities of occurrence of rare geological events. Because of large uncertainties in input data, statistical treatment of the Monte Carlo type is utilized for the analysis; thus, the output from LISA is obtained in the form of distributions. A few results of an application to a probabilistic scenario for a repository mined in a clay bed are illustrated

Possible Periodic Orbit Control Maneuvers for an eLISA Mission

Science.gov (United States)

Bender, Peter L.; Welter, Gary L.

2012-01-01

This paper investigates the possible application of periodic orbit control maneuvers for so-called evolved-LISA (eLISA) missions, i.e., missions for which the constellation arm lengths and mean distance from the Earth are substantially reduced. We find that for missions with arm lengths of 106 km and Earth-trailing distance ranging from approx. 12deg to 20deg over the science lifetime, the occasional use of the spacecraft micro-Newton thrusters for constellation configuration maintenance should be able to essentially eliminate constellation distortion caused by Earth-induced tidal forces at a cost to science time of only a few percent. With interior angle variation kept to approx. +/-0:1deg, the required changes in the angles between the laser beam pointing directions for the two arms from any spacecraft could be kept quite small. This would considerably simplify the apparatus necessary for changing the transmitted beam directions.

Acoustic waves and the detectability of first-order phase transitions by eLISA

Science.gov (United States)

Weir, David J.

2017-05-01

In various extensions of the Standard Model it is possible that the electroweak phase transition was first order. This would have been a violent process, involving the formation of bubbles and associated shock waves. Not only would the collision of these bubbles and shock waves be a detectable source of gravitational waves, but persistent acoustic waves could enhance the signal and improve prospects of detection by eLISA. I summarise the results of a recent campaign to model such a phase transition based on large-scale hydrodynamical simulations, and its implications for the eLISA mission.

LTP - LISA technology package: Development challenges of a spaceborne fundamental physics experiment

Energy Technology Data Exchange (ETDEWEB)

Gerndt, R, E-mail: ruediger.gerndt@astrium.eads.ne [Astrium Satellites GmbH, Claude-Dornier-Str., 88090 Immenstaad (Germany)

2009-03-01

The LISA Technology Package (LTP) is the main payload onboard the LISA Pathfinder Spacecraft. The LTP Instrument together with the Drag-Free Attitude Control System (DFACS) and the respective LTP and DFACS operational software forms the LTP Experiment. It is completed by the FEEPs of the LPF spacecraft that are controlled by DFACS in order to control the spacecraft's attitude along with the experiment's needs. This article concentrates on aspects of the Industrial development of the LTP Instrument items and on essential performance issues of LTP. Examples of investigations on specific issue will highlight the kind of special problems to be solved for LTP in close cooperation with the Scientific Community.

Constraining early and interacting dark energy with gravitational wave standard sirens: the potential of the eLISA mission

International Nuclear Information System (INIS)

Caprini, Chiara; Tamanini, Nicola

2016-01-01

We perform a forecast analysis of the capability of the eLISA space-based interferometer to constrain models of early and interacting dark energy using gravitational wave standard sirens. We employ simulated catalogues of standard sirens given by merging massive black hole binaries visible by eLISA, with an electromagnetic counterpart detectable by future telescopes. We consider three-arms mission designs with arm length of 1, 2 and 5 million km, 5 years of mission duration and the best-level low frequency noise as recently tested by the LISA Pathfinder. Standard sirens with eLISA give access to an intermediate range of redshift 1 ∼< z ∼< 8, and can therefore provide competitive constraints on models where the onset of the deviation from ΛCDM (i.e. the epoch when early dark energy starts to be non-negligible, or when the interaction with dark matter begins) occurs relatively late, at z ∼< 6. If instead early or interacting dark energy is relevant already in the pre-recombination era, current cosmological probes (especially the cosmic microwave background) are more efficient than eLISA in constraining these models, except possibly in the interacting dark energy model if the energy exchange is proportional to the energy density of dark energy.

Disentangling the magnetic force noise contribution in LISA Pathfinder

International Nuclear Information System (INIS)

Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

2015-01-01

Magnetically-induced forces on the inertial masses on-board LISA Pathfinder are expected to be one of the dominant contributions to the mission noise budget, accounting for up to 40%. The origin of this disturbance is the coupling of the residual magnetization and susceptibility of the test masses with the environmental magnetic field. In order to fully understand this important part of the noise model, a set of coils and magnetometers are integrated as a part of the diagnostics subsystem. During operations a sequence of magnetic excitations will be applied to precisely determine the coupling of the magnetic environment to the test mass displacement using the on-board magnetometers. Since no direct measurement of the magnetic field in the test mass position will be available, an extrapolation of the magnetic measurements to the test mass position will be carried out as a part of the data analysis activities. In this paper we show the first results on the magnetic experiments during an end- to-end LISA Pathfinder simulation, and we describe the methods under development to map the magnetic field on-board. (paper)

Review: Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday (2011 Buchbesprechung: Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday (2011

Directory of Open Access Journals (Sweden)

Jigal Beez

2013-01-01

Full Text Available Review of the monograph:Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday, Hamburg: Verlag Dr. Kovač, 2011, ISBN 978-3-8300-5806-9, 216 pagesBesprechung der Monographie:Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday, Hamburg: Verlag Dr. Kovač, 2011, ISBN 978-3-8300-5806-9, 216 Seiten

Editorial. Special issue of Classical and Quantum Gravity on the proceedings of the 4th international LISA symposium

International Nuclear Information System (INIS)

Finn, Lee Samuel

2003-01-01

The 4th International LISA Symposium was held at the National Science Foundation Physics Frontier Center for Gravitational Wave Physics at The Pennsylvania State University on 19-24 July 2002. This special issue of Classical and Quantum Gravity is the proceedings of this meeting. LISA - the Laser Interferometer Space Antenna - is part of an international effort to open a new window on the universe. Not all things radiate light, but everything gravitates. Observations of the gravitational waves radiated by black holes and compact binary star systems, in our galaxy and beyond, can reveal details about these systems and their environments that are otherwise inaccessible. The international effort, of which LISA is a part, includes ground-based detectors, and the relationship between LISA and its ground-based detector 'cousins' was an important theme for this Symposium. LISA will observe gravitational waves in the 0.1 mHz to 0.1 Hz band, complementing observations made by ground-based detectors in the 10 Hz to several KHz band. Together they will explore nearly six decades of bandwidth in the gravitational-wave sky. LISA in particular will observe the gravitational waves radiated by the coalescence of black holes at the centres of colliding galaxies, and the inspiral of compact neutron stars or stellar-mass black holes onto these black holes, virtually anywhere in the universe. It will take a census of neutron star or close white dwarf binaries in our own galaxy and observe the formation of large black holes from the very first structures to form and collapse in our universe. In doing all these things, it will shed new 'light' on the first structures to form in the universe, explore the evolution of galaxies and the roles that black holes play in their structure, test relativity near the 'edges' of a black hole, and deepen our understanding of stellar and binary system evolution. A successful conference - and this LISA Symposium, like its predecessors, was very

Influência de Alguns Fatores de Ambiente sobre os Escores de Conformação, Precocidade e Musculatura à Desmama em um Rebanho da Raça Nelore

Directory of Open Access Journals (Sweden)

Jorge Júnior João

2001-01-01

Full Text Available Dados de 23.251 animais da raça Nelore desmamados no período de 1994 a 1997, pertencentes à Agropecuária Jacarezinho Ltda., foram analisados para se avaliar os efeitos ambientais da idade da vaca, data de nascimento e idade à desmama sobre os escores visuais de conformação (C, precocidade (P e musculatura (M. Todos os efeitos estudados influenciaram significativamente os escores visuais. As análises indicaram que as vacas que pariram aos sete, oito e nove anos, obtiveram os melhores resultados para os escores visuais de C, P e M, assim como os animais que nasceram mais cedo dentro da estação de parição. Para a idade à desmama foi constatado que, quanto mais tarde o animal for desmamado, melhores serão seus escores. Os animais que desmamaram com 220 dias tiveram os melhores escores, enquanto os piores escores foram daqueles que desmamaram com 140 dias. Portanto, para se ter maior precisão na avaliação genética dos indivíduos jovens, fatores de correção para idade da vaca, data juliana de nascimento e idade à desmama devem ser utilizados sobre os escores de conformação, precocidade e musculatura.

Sub-pm{{\\sqrt{Hz}^{-1}}} non-reciprocal noise in the LISA backlink fiber

Science.gov (United States)

Fleddermann, Roland; Diekmann, Christian; Steier, Frank; Tröbs, Michael; Heinzel, Gerhard; Danzmann, Karsten

2018-04-01

The future space-based gravitational wave detector laser interferometer space antenna (LISA) requires bidirectional exchange of light between its two optical benches on board of each of its three satellites. The current baseline foresees a polarization-maintaining single-mode fiber for this backlink connection. Phase changes which are common in both directions do not enter the science measurement, but differential (‘non-reciprocal’) phase fluctuations directly do and must thus be guaranteed to be small enough. We have built a setup consisting of a Zerodur baseplate with fused silica components attached to it using hydroxide-catalysis bonding and demonstrated the reciprocity of a polarization-maintaining single-mode fiber at the 1 pm \\sqrt{Hz}-1 level as is required for LISA. We used balanced detection to reduce the influence of parasitic optical beams on the reciprocity measurement and a fiber length stabilization to avoid nonlinear effects in our phase measurement system (phase meter). For LISA, a different phase meter is planned to be used that does not show this nonlinearity. We corrected the influence of beam angle changes and temperature changes on the reciprocity measurement in post-processing.

The LISA Pathfinder DMU and Radiation Monitor

Energy Technology Data Exchange (ETDEWEB)

Canizares, P; Conchillo, A; Gesa, L; Lloro, I; Lobo, A; Mateos, I; Sopuerta, Carlos F [Institut de Ciencies de l' Espai, CSIC, Facultat de Ciencies, Torre C5 parell, 08193 Bellaterra (Spain); Chmeissani, M [Institut de Fisica d' Altes Energies (IFAE), Edifici CN, UAB Campus, 08193 Bellaterra (Spain); Diaz-Aguilo, M; GarcIa-Berro, E; Gibert, F [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Grimani, C [Universita degli Studi di Urbino, MFI Department, Via Santa Chiara 27, 61029 Urbino, and INFN Florence (Italy); Nofrarias, M [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, D-30167 Hannover (Germany); Ramos-Castro, J [Departament d' Enginyeria Electronica, UPC, Campus Nord, Edifici C4, Jordi Girona 1-3, 08034 Barcelona (Spain); Sanjuan, J [Department of Physics, University of Florida, NPB-22258 PO Box 118 440, Gainesville, FL 32611-8440 (United States); Araujo, H M; Wass, P, E-mail: lobo@ieec.fcr.es [High Energy Physics Blackett Laboratory, Prince Consort Road, Imperial College London, London SW7 2BW (United Kingdom)

2011-05-07

The LISA Pathfinder DMU (Data Management Unit) flight model was formally accepted by ESA and ASD on 11 February 2010, after all hardware and software tests had been successfully completed. The diagnostics items are scheduled to be delivered by the end of 2010. In this paper, we review the requirements and performance of this instrumentation, specially focusing on the Radiation Monitor and the DMU, as well as the status of their programmed use during mission operations, on which work is ongoing at the time of writing.

Renormalized second post-Newtonian spin contributions to the accumulated orbital phase for LISA sources

International Nuclear Information System (INIS)

Gergely, Laszlo Arpad; Mikoczi, Balazs

2009-01-01

We give here a new third post-Newtonian (3PN) spin-spin contribution (in the PN parameter ε) to the accumulated orbital phase of a compact binary, arising from the spin-orbit precessional motion of the spins. In the equal mass case, this contribution vanishes, but Laser Interferometer Space Antenna (LISA) sources of merging supermassive binary black holes have typically a mass ratio of 1:10. For such nonequal masses, this 3PN correction is periodic in time, with a period approximately ε -1 times larger than the period of gravitational waves. We derive a renormalized and simpler expression of the spin-spin coefficient at 2PN, as an average over the time scale of this period of the combined 2PN and 3PN contribution. We also find that for LISA sources the quadrupole-monopole contribution to the phase dominates over the spin-spin contribution, while the self-spin contribution is negligible even for the dominant spin. Finally, we define a renormalized total spin coefficient σ to be employed in the search for gravitational waves emitted by LISA sources.

Cinemática e ação da musculatura do tornozelo em indivíduos com hemiparesia durante o andar para trás

OpenAIRE

Azevedo, Alexandre Kretzer e Castro de

2015-01-01

Um dos possíveis mecanismos que explicaria o aumento da velocidade do andar para frente (AF) após o treinamento do andar para trás (AT) em pessoas com hemiparesia poderia ser um maior recrutamento da musculatura do tornozelo durante a tarefa de AT. Pretendeu-se com esta pesquisa comparar a ativação muscular de dorsi e plantiflexores e a amplitude de movimento do tornozelo durante as tarefas de AF e AT entre sujeitos com hemiparesia pós-AVE e indivíduos controle saudáveis. Participaram do estu...

GRS vs. OMS Calibration in LISA Pathfinder Data Analysis

Science.gov (United States)

Meshksar, Neda; Ferraioli, Luigi; Mance, Davor; ten Pierick, Jan; Zweifel, Peter; Giardini, Domenico; ">LISA Pathfinder colaboration, LISA Pathfinder spacecraft the test mass displacement along the main measurement axis is sensed in two different ways: optically and electrostatically. We have monitored the relative calibration between the two measurements during the mission science phase. The trend sensitivity of the relative calibration has been computed for different physical parameters, such as temperature, magnetic field, test mass bias voltage and current.

Automatic system for quantification and visualization of lung aeration on chest computed tomography images: the Lung Image System Analysis - LISA

International Nuclear Information System (INIS)

Felix, John Hebert da Silva; Cortez, Paulo Cesar; Holanda, Marcelo Alcantara

2010-01-01

High Resolution Computed Tomography (HRCT) is the exam of choice for the diagnostic evaluation of lung parenchyma diseases. There is an increasing interest for computational systems able to automatically analyze the radiological densities of the lungs in CT images. The main objective of this study is to present a system for the automatic quantification and visualization of the lung aeration in HRCT images of different degrees of aeration, called Lung Image System Analysis (LISA). The secondary objective is to compare LISA to the Osiris system and also to specific algorithm lung segmentation (ALS), on the accuracy of the lungs segmentation. The LISA system automatically extracts the following image attributes: lungs perimeter, cross sectional area, volume, the radiological densities histograms, the mean lung density (MLD) in Hounsfield units (HU), the relative area of the lungs with voxels with density values lower than -950 HU (RA950) and the 15th percentile of the least density voxels (PERC15). Furthermore, LISA has a colored mask algorithm that applies pseudo-colors to the lung parenchyma according to the pre-defined radiological density chosen by the system user. The lungs segmentations of 102 images of 8 healthy volunteers and 141 images of 11 patients with Chronic Obstructive Pulmonary Disease (COPD) were compared on the accuracy and concordance among the three methods. The LISA was more effective on lungs segmentation than the other two methods. LISA's color mask tool improves the spatial visualization of the degrees of lung aeration and the various attributes of the image that can be extracted may help physicians and researchers to better assess lung aeration both quantitatively and qualitatively. LISA may have important clinical and research applications on the assessment of global and regional lung aeration and therefore deserves further developments and validation studies. (author)

Automatic system for quantification and visualization of lung aeration on chest computed tomography images: the Lung Image System Analysis - LISA

Energy Technology Data Exchange (ETDEWEB)

Felix, John Hebert da Silva; Cortez, Paulo Cesar, E-mail: jhsfelix@gmail.co [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia de Teleinformatica; Holanda, Marcelo Alcantara [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Hospital Universitario Walter Cantidio. Dept. de Medicina Clinica

2010-12-15

High Resolution Computed Tomography (HRCT) is the exam of choice for the diagnostic evaluation of lung parenchyma diseases. There is an increasing interest for computational systems able to automatically analyze the radiological densities of the lungs in CT images. The main objective of this study is to present a system for the automatic quantification and visualization of the lung aeration in HRCT images of different degrees of aeration, called Lung Image System Analysis (LISA). The secondary objective is to compare LISA to the Osiris system and also to specific algorithm lung segmentation (ALS), on the accuracy of the lungs segmentation. The LISA system automatically extracts the following image attributes: lungs perimeter, cross sectional area, volume, the radiological densities histograms, the mean lung density (MLD) in Hounsfield units (HU), the relative area of the lungs with voxels with density values lower than -950 HU (RA950) and the 15th percentile of the least density voxels (PERC15). Furthermore, LISA has a colored mask algorithm that applies pseudo-colors to the lung parenchyma according to the pre-defined radiological density chosen by the system user. The lungs segmentations of 102 images of 8 healthy volunteers and 141 images of 11 patients with Chronic Obstructive Pulmonary Disease (COPD) were compared on the accuracy and concordance among the three methods. The LISA was more effective on lungs segmentation than the other two methods. LISA's color mask tool improves the spatial visualization of the degrees of lung aeration and the various attributes of the image that can be extracted may help physicians and researchers to better assess lung aeration both quantitatively and qualitatively. LISA may have important clinical and research applications on the assessment of global and regional lung aeration and therefore deserves further developments and validation studies. (author)

LISA time-delay interferometry zero-signal solution: Geometrical properties

International Nuclear Information System (INIS)

Tinto, Massimo; Larson, Shane L.

2004-01-01

Time-delay interferometry (TDI) is the data processing technique needed for generating interferometric combinations of data measured by the multiple Doppler readouts available onboard the three Laser Interferometer Space Antenna (LISA) spacecraft. Within the space of all possible interferometric combinations TDI can generate, we have derived a specific combination that has zero response to the gravitational wave signal, and called it the zero-signal solution (ZSS). This is a two-parameter family of linear combinations of the generators of the TDI space, and its response to a gravitational wave becomes null when these two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the ZSS does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind. Our approach is analogous to the data analysis method introduced by Guersel and Tinto in the context of networks of Earth-based, wideband, interferometric gravitational wave detectors observing in coincidence a gravitational wave burst. The ZSS should be regarded as an application of the Guersel and Tinto method to the LISA data

Classifying LISA gravitational wave burst signals using Bayesian evidence

International Nuclear Information System (INIS)

Feroz, Farhan; Graff, Philip; Hobson, Michael P; Lasenby, Anthony; Gair, Jonathan R

2010-01-01

We consider the problem of characterization of burst sources detected by the Laser Interferometer Space Antenna (LISA) using the multi-modal nested sampling algorithm, MultiNest. We use MultiNest as a tool to search for modelled bursts from cosmic string cusps, and compute the Bayesian evidence associated with the cosmic string model. As an alternative burst model, we consider sine-Gaussian burst signals, and show how the evidence ratio can be used to choose between these two alternatives. We present results from an application of MultiNest to the last round of the Mock LISA Data Challenge, in which we were able to successfully detect and characterize all three of the cosmic string burst sources present in the release data set. We also present results of independent trials and show that MultiNest can detect cosmic string signals with signal-to-noise ratio (SNR) as low as ∼7 and sine-Gaussian signals with SNR as low as ∼8. In both cases, we show that the threshold at which the sources become detectable coincides with the SNR at which the evidence ratio begins to favour the correct model over the alternative.

FONTES DE ESPÉCIES REATIVAS DE OXIGÊNIO NA MUSCULATURA ESQUELÉTICA DURANTE O EXERCÍCIO

Directory of Open Access Journals (Sweden)

Paulo Guimarães Gandra

2006-10-01

Full Text Available O músculo esquelético gera constantemente espécies reativas de oxigênio, através da reduçãomonoeletrônica do oxigênio molecular. Durante o exercício físico o consumo de oxigênio pelamusculatura esquelética exercitada pode ser aumentado em aproximadamente 100 vezes.Acredita-se que a geração de espécies reativas de oxigênio deve ser proporcional a esteaumento. O objetivo deste trabalho é apresentar todos os possíveis locais e mecanismos deprodução de espécies reativas de oxigênio na musculatura esquelética durante o exercíciofísico. A tradicional visão de que o aumento do consumo de oxigênio e o aumento do fluxo deelétrons pela cadeia de transporte de elétrons mitocondrial regulam a produção de espéciesreativas de oxigênio durante e após o exercício pode não ser exclusiva, nem a mais importanteao considerarmos os vários tipos de exercício.

GRS vs. OMS Calibration in LISA Pathfinder Data Analysis

International Nuclear Information System (INIS)

Meshksar, Neda; Ferraioli, Luigi; Mance, Davor; Zweifel, Peter; Giardini, Domenico; Ten Pierick, Jan

2017-01-01

On board LISA Pathfinder spacecraft the test mass displacement along the main measurement axis is sensed in two different ways: optically and electrostatically. We have monitored the relative calibration between the two measurements during the mission science phase. The trend sensitivity of the relative calibration has been computed for different physical parameters, such as temperature, magnetic field, test mass bias voltage and current. (paper)

Professor Lisa Aranson on JA Green (a pioonier artist photographer ...

African Journals Online (AJOL)

Jonathan Adagogo Green's photographic and artistic contributions working in his countryside, the Niger Delta of Nigeria is reviewed by Professor Lisa Aranson. Aranson in a public lecture presentation on the stand-point of art history thinks of J.A. Green as having operated in two worlds of which he is said to have initiated in ...

arXiv Probing non-Gaussian Stochastic Gravitational Wave Backgrounds with LISA

CERN Document Server

Bartolo, Nicola; Figueroa, Daniel G.; Garcia-Bellido, Juan; Peloso, Marco; Pieroni, Mauro; Ricciardone, Angelo; Sakellariadou, Mairi; Sorbo, Lorenzo; Tasinato, Gianmassimo

The stochastic gravitational wave background (SGWB) contains a wealth of information on astrophysical and cosmological processes. A major challenge of upcoming years will be to extract the information contained in this background and to disentangle the contributions of different sources. In this paper we provide the formalism to extract, from the correlation of three signals in the Laser Interferometer Space Antenna (LISA), information about the tensor three-point function, which characterizes the non-Gaussian properties of the SGWB. Compared to the two-point function, the SGWB three-point function has a richer dependence on the gravitational wave momenta and chiralities, and a larger number of signal channels. It can be used therefore as a powerful discriminator between different models. We provide LISA's response functions to a general SGWB three-point function. As examples, we study in full detail the cases of an equilateral and squeezed SGWB bispectra, and provide the explicit form of the response functio...

Revised electrostatic model of the LISA Pathfinder inertial sensor

Energy Technology Data Exchange (ETDEWEB)

Brandt, Nico [Astrium GmbH, 88039 Friedrichshafen (Germany); Fichter, Walter, E-mail: nico.brandt@astrium.eads.ne [iFR, Universitaet Stuttgart, Pfaffenwaldring 7a, 70569 Stuttgart (Germany)

2009-03-01

A comprehensive electrostatic finite-element (FE) analysis of the LISA Pathfinder Inertial Sensor (IS) has been carried out at Astrium GmbH. Starting with a detailed geometrical model of the IS housing and test mass (TM) flight units, FE results were derived from multiple analyses runs applying the Maxwell 3D field simulation software. The electrostatic forces and torques on the TM in 6DoF, as well as all non-negligible capacitances between the TM, the 18 electrodes, and the housing, have been extracted for different TM translations and rotations. The results of the FE analyses were expected to confirm the existing IS electrostatic model predictions used for performance analysis, simulations, and on-board algorithms. Major discrepancies were found, however, between the results and the model used so far. In general, FE results give considerably larger capacitance values than the equivalent infinite non-parallel plate estimates. In contrast, the FE derived forces and torques are in general significantly lower compared to the analytic IS electrostatic model predictions. In this paper, these results are discussed in detail and the reasons for the deviations are elaborated. Based on these results, an adapted analytic IS electrostatic model is proposed that reflects the electrostatic forces, torques, and stiffness values in the LISA Pathfinder IS significantly more accurate.

Revised electrostatic model of the LISA Pathfinder inertial sensor

International Nuclear Information System (INIS)

Brandt, Nico; Fichter, Walter

2009-01-01

A comprehensive electrostatic finite-element (FE) analysis of the LISA Pathfinder Inertial Sensor (IS) has been carried out at Astrium GmbH. Starting with a detailed geometrical model of the IS housing and test mass (TM) flight units, FE results were derived from multiple analyses runs applying the Maxwell 3D field simulation software. The electrostatic forces and torques on the TM in 6DoF, as well as all non-negligible capacitances between the TM, the 18 electrodes, and the housing, have been extracted for different TM translations and rotations. The results of the FE analyses were expected to confirm the existing IS electrostatic model predictions used for performance analysis, simulations, and on-board algorithms. Major discrepancies were found, however, between the results and the model used so far. In general, FE results give considerably larger capacitance values than the equivalent infinite non-parallel plate estimates. In contrast, the FE derived forces and torques are in general significantly lower compared to the analytic IS electrostatic model predictions. In this paper, these results are discussed in detail and the reasons for the deviations are elaborated. Based on these results, an adapted analytic IS electrostatic model is proposed that reflects the electrostatic forces, torques, and stiffness values in the LISA Pathfinder IS significantly more accurate.

Effects of different eLISA-like configurations on massive black hole parameter estimation

Science.gov (United States)

Porter, Edward K.

2015-09-01

As the theme for the future L3 Cosmic Vision mission, ESA has recently chosen the "Gravitational Wave Universe." Within this program, a mission concept called eLISA has been proposed. This observatory has a current initial configuration consisting of four laser links between the three satellites, which are separated by a distance of one million kilometers, constructing a single-channel Michelson interferometer. However, the final configuration for the observatory will not be fixed until the end of this decade. With this in mind, we investigate the effect of different eLISA-like configurations on massive black hole detections. This work compares the results of a Bayesian inference study of 120 massive black hole binaries out to a redshift of z ˜13 for a 106 km arm length eLISA with four and six links, as well as a 2 ×106 km arm length observatory with four links. We demonstrate that the original eLISA configuration should allow us to recover the luminosity distance of the source with an error of less than 10% out to a redshift of z ˜4 , and a sky error box of Δ Ω ≤102 deg2 out to z ˜0.1 . In contrast, both alternative configurations suggest that we should be able to conduct the same parameter recovery with errors of less than 10% in luminosity distance out to z ˜12 and Δ Ω ≤102 deg2 out to z ˜0.4 . Using the information from these studies, we also infer that if we were able to construct a 2 Gm, six-link detector, the above values would shift to z ˜20 for luminosity distance and z ˜0.9 for sky error. While the final configuration will also be dependent on both technological and financial considerations, our study suggests that increasing the size of a two-arm detector is a viable alternative to the inclusion of a third arm in a smaller detector. More importantly, this work further suggests no clear scientific loss between either choice.

Lifetime testing UV LEDs for use in the LISA charge management system

Science.gov (United States)

Hollington, D.; Baird, J. T.; Sumner, T. J.; Wass, P. J.

2017-10-01

As a future charge management light source, UV light-emitting diodes (UV LEDs) offer far superior performance in a range of metrics compared to the mercury lamps used in the past. As part of a qualification program a number of short wavelength UV LEDs have been subjected to a series of lifetime tests for potential use on the laser interferometer space antenna (LISA) mission. These tests were performed at realistic output levels for both fast and continuous discharging in either a DC or pulsed mode of operation and included a DC fast discharge test spanning 50 days, a temperature dependent pulsed fast discharge test spanning 21 days and a pulsed continuous discharge test spanning 507 days. Two types of UV LED have demonstrated lifetimes equivalent to over 25 years of realistic mission usage with one type providing a baseline for LISA and the other offering a backup solution.

Lifetime testing UV LEDs for use in the LISA charge management system

International Nuclear Information System (INIS)

Hollington, D; Baird, J T; Sumner, T J; Wass, P J

2017-01-01

As a future charge management light source, UV light-emitting diodes (UV LEDs) offer far superior performance in a range of metrics compared to the mercury lamps used in the past. As part of a qualification program a number of short wavelength UV LEDs have been subjected to a series of lifetime tests for potential use on the laser interferometer space antenna (LISA) mission. These tests were performed at realistic output levels for both fast and continuous discharging in either a DC or pulsed mode of operation and included a DC fast discharge test spanning 50 days, a temperature dependent pulsed fast discharge test spanning 21 days and a pulsed continuous discharge test spanning 507 days. Two types of UV LED have demonstrated lifetimes equivalent to over 25 years of realistic mission usage with one type providing a baseline for LISA and the other offering a backup solution. (paper)

LISA Pathfinder E2E performance simulation: optical and self-gravity stability analysis

Science.gov (United States)

Brandt, N.; Fichter, W.; Kersten, M.; Lucarelli, S.; Montemurro, F.

2005-05-01

End-to-end (E2E) modelling and simulation, i.e. verifying the science performance of LISA Pathfinder (spacecraft and payload), is mandatory in order to minimize mission risks. In this paper, focus is on two particular applications of the E2E performance simulator currently being developed at EADS Astrium GmbH: the opto-dynamical stability and the self-gravity disturbance stability analysis. The E2E models applied here comprise the opto-dynamical modelling of the optical metrology systems (OMS) laser interferometry, the thermo-elastic distortion modelling of the OMS optical elements and the self-gravity disturbance model accounting for structural distortions. Preliminary analysis results are presented in detail, identifying shortcomings of the current LISA technology package (LTP) mounting baseline. As a consequence, the design is now being revised.

LISA Pathfinder E2E performance simulation: optical and self-gravity stability analysis

International Nuclear Information System (INIS)

Brandt, N; Fichter, W; Kersten, M; Lucarelli, S; Montemurro, F

2005-01-01

End-to-end (E2E) modelling and simulation, i.e. verifying the science performance of LISA Pathfinder (spacecraft and payload), is mandatory in order to minimize mission risks. In this paper, focus is on two particular applications of the E2E performance simulator currently being developed at EADS Astrium GmbH: the opto-dynamical stability and the self-gravity disturbance stability analysis. The E2E models applied here comprise the opto-dynamical modelling of the optical metrology systems (OMS) laser interferometry, the thermo-elastic distortion modelling of the OMS optical elements and the self-gravity disturbance model accounting for structural distortions. Preliminary analysis results are presented in detail, identifying shortcomings of the current LISA technology package (LTP) mounting baseline. As a consequence, the design is now being revised

Actuation crosstalk in free-falling systems: Torsion pendulum results for the engineering model of the LISA pathfinder gravitational reference sensor

Science.gov (United States)

Bassan, M.; Cavalleri, A.; De Laurentis, M.; De Marchi, F.; De Rosa, R.; Di Fiore, L.; Dolesi, R.; Finetti, N.; Garufi, F.; Grado, A.; Hueller, M.; Marconi, L.; Milano, L.; Minenkov, Y.; Pucacco, G.; Stanga, R.; Vetrugno, D.; Visco, M.; Vitale, S.; Weber, W. J.

2018-01-01

In this paper we report on measurements on actuation crosstalk, relevant to the gravitational reference sensors for LISA Pathfinder and LISA. In these sensors, a Test Mass (TM) falls freely within a system of electrodes used for readout and control. These measurements were carried out on ground with a double torsion pendulum that allowed us to estimate both the torque injected into the sensor when a control force is applied and, conversely, the force leaking into the translational degree of freedom due to the applied torque.The values measured on our apparatus (the engineering model of the LISA Pathfinder sensor) agree to within 0.2% (over a maximum measured crosstalk of 1%) with predictions of a mathematical model when measuring force to torque crosstalk, while it is somewhat larger than expected (up to 3.5%) when measuring torque to force crosstalk. However, the values in the relevant range, i.e. when the TM is well centered ( ± 10 μm) in the sensor, remain smaller than 0.2%, satisfying the LISA Pathfinder requirements.

Modulator noise suppression in the LISA time-delay interferometric combinations

International Nuclear Information System (INIS)

Tinto, Massimo; Armstrong, J W; Estabrook, Frank B

2008-01-01

Laser Interferometer Space Antenna (LISA) is a mission to detect and study low-frequency cosmic gravitational radiation through its influence on the phases of six modulated laser beams exchanged between three remote spacecraft. We previously showed how the measurements of some 18 time series of relative frequency or phase shifts could be combined (1) to cancel the phase noise of the lasers, (2) to cancel the Doppler fluctuations due to non-inertial motions of the six optical benches and (3) to remove the phase noise of the onboard reference oscillators required to track the photodetector fringes, all the while preserving signals from passing gravitational waves. Here we analyze the effect of the additional noise due to the optical modulators used for removing the phase fluctuations of the onboard reference oscillators. We use the recently measured noise spectrum of an individual modulator (Klipstein et al 2006 Proc. 6th Int. LISA Symp. (Greenbelt, MA) (AIP Conf. Proc. vol 873) ed S M Merkowitz and J C Livas pp 19-23) to quantify the contribution of modulator noise to the first and second-generation time-delay interferometric (TDI) combinations as a function of the modulation frequency. We show that modulator noise can be made smaller than the expected proof-mass acceleration and optical-path noises if the modulation frequencies are larger than ∼682 MHz in the case of the unequal-arm Michelson TDI combination X 1 , ∼ 1.08 GHz for the Sagnac TDI combination α 1 , and ∼706 MHz for the symmetrical Sagnac TDI combination ζ 1 . These modulation frequencies are substantially smaller than previously estimated and may lead to less stringent requirements on the LISA's oscillator noise calibration subsystem. The measurements in Klipstein et al were performed in a laboratory experiment for a range of modulation frequencies, but we emphasize that, for the reference oscillator noise calibration algorithm to work, the modulation frequencies must be equal to the

The Mock LISA Data Challenges: from Challenge 1B to Challenge 3

International Nuclear Information System (INIS)

Babak, Stanislav; Porter, Edward K; Gair, Jonathan; Baker, John G; Arnaud, Keith; Benacquista, Matthew J; Cornish, Neil J; Crowder, Jeff; Vallisneri, Michele; Cutler, Curt; Larson, Shane L; Plagnol, Eric; Vecchio, Alberto; Barack, Leor; Blaut, Arkadiusz; Fairhurst, Stephen; Harry, Ian; Gong Xuefei; Khurana, Deepak; Krolak, Andrzej

2008-01-01

The Mock LISA Data Challenges are a programme to demonstrate and encourage the development of LISA data-analysis capabilities, tools and techniques. At the time of this workshop, three rounds of challenges had been completed, and the next was about to start. In this paper we provide a critical analysis of the entries to the latest completed round, Challenge 1B. The entries confirm the consolidation of a range of data-analysis techniques for galactic and massive-black-hole binaries, and they include the first convincing examples of detection and parameter estimation of extreme-mass-ratio inspiral sources. In this paper we also introduce the next round, Challenge 3. Its data sets feature more realistic waveform models (e.g., galactic binaries may now chirp, and massive-black-hole binaries may precess due to spin interactions), as well as new source classes (bursts from cosmic strings, isotropic stochastic backgrounds) and more complicated nonsymmetric instrument noise

Detection of Double White Dwarf Binaries with Gaia, LSST and eLISA

Science.gov (United States)

Korol, V.; Rossi, E. M.; Groot, P. J.

2017-03-01

According to simulations around 108 double degenerate white dwarf binaries are expected to be present in the Milky Way. Due to their intrinsic faintness, the detection of these systems is a challenge, and the total number of detected sources so far amounts only to a few tens. This will change in the next two decades with the advent of Gaia, the LSST and eLISA. We present an estimation of how many compact DWDs with orbital periods less than a few hours we will be able to detect 1) through electromagnetic radiation with Gaia and LSST and 2) through gravitational wave radiation with eLISA. We find that the sample of simultaneous electromagnetic and gravitational waves detections is expected to be substantial, and will provide us a powerful tool for probing the white dwarf astrophysics and the structure of the Milky Way, letting us into the era of multi-messenger astronomy for these sources.

The magnetic diagnostics subsystem of the LISA Technology Package

Energy Technology Data Exchange (ETDEWEB)

Diaz-Aguilo, M; Garcia-Berro, E [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, 08860 Castelldefels (Spain); Lobo, A; Mateos, N; Sanjuan, J, E-mail: marc.diaz.aguilo@fa.upc.ed [Institut d' Estudis Espacials de Catalunya, c/Gran Capita 2-4, Edif. Nexus 104, 08034 Barcelona (Spain)

2010-05-01

The Magnetic Diagnostics Subsystem of the LISA Technology Package (LTP) on board the LISA Pathfinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at the positions they occupy. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses. Therefore, an interpolation method must be implemented to obtain this information. However, such interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable, and the number of magnetometer channels does not provide sufficient data to go beyond that poor approximation. Recent research points to a possible alternative to address the magnetic interpolation problem by means of neural network algorithms. The key point of this approach is the ability neural networks have to learn from suitable training data representing the magnetic field behaviour. Despite the large distance to the test masses and the insufficient magnetic readings, artificial neural networks are able to significantly reduce the estimation error to acceptable levels. The learning efficiency can be best improved by making use of data obtained from on-ground measurements prior to mission launch in all relevant satellite locations and under real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

The magnetic diagnostics subsystem of the LISA Technology Package

International Nuclear Information System (INIS)

Diaz-Aguilo, M; Garcia-Berro, E; Lobo, A; Mateos, N; Sanjuan, J

2010-01-01

The Magnetic Diagnostics Subsystem of the LISA Technology Package (LTP) on board the LISA Pathfinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at the positions they occupy. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses. Therefore, an interpolation method must be implemented to obtain this information. However, such interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable, and the number of magnetometer channels does not provide sufficient data to go beyond that poor approximation. Recent research points to a possible alternative to address the magnetic interpolation problem by means of neural network algorithms. The key point of this approach is the ability neural networks have to learn from suitable training data representing the magnetic field behaviour. Despite the large distance to the test masses and the insufficient magnetic readings, artificial neural networks are able to significantly reduce the estimation error to acceptable levels. The learning efficiency can be best improved by making use of data obtained from on-ground measurements prior to mission launch in all relevant satellite locations and under real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

Search for a stochastic gravitational-wave signal in the second round of the Mock LISA Data Challenges

International Nuclear Information System (INIS)

Robinson, E L; Vecchio, A; Romano, J D

2008-01-01

The analysis method currently proposed to search for isotropic stochastic radiation with the Laser Interferometer Space Antenna (LISA) relies on the combined use of two LISA channels, one of which is insensitive to gravitational waves, such as the symmetrized Sagnac. For this method to work, it is essential to know how the instrumental noise power in the two channels are related to one another; however, no quantitative estimates of this key information are available to date. The purpose of our study is to assess the performance of the symmetrized Sagnac method for different levels of prior information regarding the instrumental noise. We develop a general approach in the framework of Bayesian inference and an end-to-end analysis algorithm based on Markov chain Monte Carlo methods to compute the posterior probability density functions of the relevant model parameters. We apply this method to data released as part of the second round of the Mock LISA Data Challenges. For the selected (and somewhat idealized) example cases considered here, we find that for a signal whose amplitude dominates the instrumental noise by a factor ∼25, a prior uncertainty of a factor ∼2 in the ratio between the power of the instrumental noise contributions in the two channels allows for the detection of isotropic stochastic radiation. More importantly, we provide a framework for more realistic studies of LISA's performance and development of analysis techniques in the context of searches for stochastic signals

Observing extreme-mass-ratio inspirals with eLISA/NGO

OpenAIRE

Gair, Jonathan R; Porter, Edward K

2012-01-01

The extreme-mass-ratio inspirals (EMRIs) of stellar mass compact objects into massive black holes in the centres of galaxies are an important source of low-frequency gravitational waves for space-based detectors. We discuss the prospects for detecting these sources with the evolved Laser Interferometer Space Antenna (eLISA), recently proposed as an ESA mission candidate under the name NGO. We show that NGO could observe a few tens of EMRIs over its two year mission lifetime at redshifts z < 0...

Fundamentals of the LISA stable flight formation

International Nuclear Information System (INIS)

Dhurandhar, S V; Nayak, K Rajesh; Koshti, S; Vinet, J-Y

2005-01-01

The joint NASA-ESA mission, LISA, relies crucially on the stability of the three-spacecraft constellation. Each of the spacecraft is in heliocentric orbit forming a stable triangle. In this paper we explicitly show with the help of the Clohessy-Wiltshire equations that any configuration of spacecraft lying in the planes making angles of ±60 0 with the ecliptic and given suitable initial velocities within the plane, can be made stable in the sense that the inter-spacecraft distances remain constant to first order in the dimensions of the configuration compared with the distance to the Sun. Such analysis would be useful in order to carry out theoretical studies on the optical links, simulators, etc

O efeito da eletroestimulação neuromuscular na contração da musculatura supra-hióidea durante a deglutição de indivíduos com disfagia

Directory of Open Access Journals (Sweden)

Maíra Barbosa Lobo

Full Text Available RESUMO Objetivo: verificar o efeito da Eletroestimulação Neuromuscular na contração da musculatura supra-hióidea durante a deglutição em indivíduos pós-Acidente Vascular Cerebral com disfagia orofaríngea. Métodos: participaram da pesquisa oito indivíduos pós-Acidente Vascular Cerebral com disfagia, de ambos os sexos, encaminhados para terapia fonoaudiológica com objetivo de trabalhar a função da deglutição, em início de processo terapêutico. Anteriormente ao início da primeira sessão, foi realizada a mensuração do tempo e amplitude da atividade elétrica muscular através da Eletromiografia de Superfície de Biofeedback. Os pacientes foram divididos aleatoriamente em dois grupos: Grupo Experimental (n=4: pacientes que receberam a fonoterapia tradicional e aplicação da Eletroestimulação Neuromuscular; Grupo Controle (n=4: pacientes que receberam a fonoterapia tradicional. Após oito sessões, todos os pacientes passaram novamente pela Eletromiografia de Superfície de Biofeedback para verificar a atividade elétrica da musculatura supra-hióidea. Os registros dos exames pré e pós intervenção foram comparados nos dois grupos. Resultados: comparando-se as médias das variáveis de amplitude e tempo da atividade elétrica muscular durante a deglutição de saliva e nas duas deglutições de pastoso, não foram observadas diferenças estatisticamente significantes entre os grupos estudados, na comparação dos valores pré e pós intervenção. Conclusões: o uso da Eletroestimulação Neuromuscular nos parâmetros e na metodologia empregada não mostrou-se eficiente em promover maior contração da musculatura supra-hióidea durante a deglutição em indivíduos pós-Acidente Vascular Cerebral com disfagia orofaríngea. Os dados encontrados podem ser decorrentes da metodologia utilizada nesta pesquisa com relação ao protocolo de aplicação da técnica e à forma de mensuração dos resultados.

Rapid prototyping and evaluation of programmable SIMD SDR processors in LISA

Science.gov (United States)

Chen, Ting; Liu, Hengzhu; Zhang, Botao; Liu, Dongpei

2013-03-01

With the development of international wireless communication standards, there is an increase in computational requirement for baseband signal processors. Time-to-market pressure makes it impossible to completely redesign new processors for the evolving standards. Due to its high flexibility and low power, software defined radio (SDR) digital signal processors have been proposed as promising technology to replace traditional ASIC and FPGA fashions. In addition, there are large numbers of parallel data processed in computation-intensive functions, which fosters the development of single instruction multiple data (SIMD) architecture in SDR platform. So a new way must be found to prototype the SDR processors efficiently. In this paper we present a bit-and-cycle accurate model of programmable SIMD SDR processors in a machine description language LISA. LISA is a language for instruction set architecture which can gain rapid model at architectural level. In order to evaluate the availability of our proposed processor, three common baseband functions, FFT, FIR digital filter and matrix multiplication have been mapped on the SDR platform. Analytical results showed that the SDR processor achieved the maximum of 47.1% performance boost relative to the opponent processor.

Constraints on LISA Pathfinder's Self-Gravity: Design Requirements, Estimates and Testing Procedures

Science.gov (United States)

Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, M.; Brandt, Nico; Bursi, Alessandro; Slutsky. J.;

Searching for massive black hole binaries in the first Mock LISA Data Challenge

International Nuclear Information System (INIS)

Cornish, Neil J; Porter, Edward K

2007-01-01

The Mock LISA Data Challenge is a worldwide effort to solve the LISA data analysis problem. We present here our results for the massive black hole binary (BBH) section of round 1. Our results cover challenge 1.2.1, where the coalescence of the binary is seen, and challenge 1.2.2, where the coalescence occurs after the simulated observational period. The data stream is composed of Gaussian instrumental noise plus an unknown BBH waveform. Our search algorithm is based on a variant of the Markov chain Monte Carlo method that uses Metropolis-Hastings sampling and thermostated frequency annealing. We present results from the training data sets where we know the parameter values a priori and the blind data sets where we were informed of the parameter values after the challenge had finished. We demonstrate that our algorithm is able to rapidly locate the sources, accurately recover the source parameters and provide error estimates for the recovered parameters

GCR flux 9-day variations with LISA Pathfinder

International Nuclear Information System (INIS)

Grimani, C; Benella, S; Fabi, M; Finetti, N; Telloni, D

2017-01-01

Galactic cosmic-ray (GCR) energy spectra in the heliosphere vary on the basis of the level of solar activity, the status of solar polarity and interplanetary transient magnetic structures of solar origin. A high counting rate particle detector (PD) aboard LISA Pathfinder (LPF) allows for the measurement of galactic cosmic-ray and solar energetic particle (SEP) integral fluxes at energies > 70 MeV n −1 up to 6500 counts s −1 . Data are gathered with a sampling time of 15 s. A study of GCR flux depressions associated with the third harmonic of the Sun rotation period (∼ 9 days) is presented here. (paper)

Numerical code to determine the particle trapping region in the LISA machine

International Nuclear Information System (INIS)

Azevedo, M.T. de; Raposo, C.C. de; Tomimura, A.

1984-01-01

A numerical code is constructed to determine the trapping region in machine like LISA. The variable magnetic field is two deimensional and is coupled to the Runge-Kutta through the Tchebichev polynomial. Various particle orbits including particle interactions were analysed. Beside this, a strong electric field is introduced to see the possible effects happening inside the plasma. (Author) [pt

The End of Panopticon/panopticism in William Gibson’s Mona Lisa Overdrive : A Baudrillardian Reading

Directory of Open Access Journals (Sweden)

Hanieh Zaltash

2014-11-01

Full Text Available This paper seeks to examine William Gibson’s Mona Lisa Overdrive as a cyberpunk novel in the light of Baudrillard’s theory of “Simulation”. Jean Baudrillard believes that reality is replaced by “hyperreality” and human beings live in a total “simulation” in which everything, such as power might be simulated. Thus, according to Baudrillard, power exists just as “the simulation of power” which is the result of “the circularization of power” between the dominator and the dominated. Baudrillard delineates “the circularization of power” through criticizing Michel Foucault’s theories regarding power and panopticon, and introduces “the end of panopticon” which is centered upon the reversibility of the positions of the observer and the observed. In a meticulous analysis of TV performance of the Loud family in 1971, Baudrillard claims that the panoptic system is ended through playing on the opposition of seeing and being seen. The findings suggest that Mona Lisa Overdrive depicts “the end of panopticon,” in a sense that Angie Mitchell in this novel can be considered as a counterpart for Baudrillard’s instance of the Loud family. Indeed, this study attempts to elucidate “the end of panopticon” in Mona Lisa Overdrive (1988 through scrutinizing Angie Mitchell’s way of living.

Supermassive Black Holes as Revealed by LISA: How Gravitational Wave Astronomy Will be a Game Changer

Science.gov (United States)

Holley-Bockelmann, Kelly

2018-04-01

Astronomers now know that supermassive black holes are in nearly every galaxy.Though these black holes are an observational certainty, nearly every aspect of their evolution -- from their birth, to their fuel source, to their basic dynamics -- is a matter of lively debate. Fortunately, LISA, a space-based gravitational wave observatory set to launch in 2034, will revolutionize this field by providing data that is complementary to electromagnetic observations as well as data in regimes that are electromagnetically dark. This talk will touch on our current understanding of how SMBHs form, evolve, and alter their galaxy host, and will outline the theoretical, computational and observational work needed to make the most of LISA observations.

Alterações na função erétil induzidas por castração cirúrgica em camundongos C57bl/6 - avaliação das vias : óxido nítrico-GMP cíclico-fosfodiesterase 5 e Rho-cinase

OpenAIRE

Rodrigo de Oliveira Capel Martins

2011-01-01

Resumo: A ereção peniana é um fenômeno vascular sob controle psicológico modulado por andrógenos onde o estado de flacidez ou ereção peniana é determinado pela condição momentânea de contração ou relaxamento do sistema arterial cavernoso e da musculatura lisa trabecular. Já a disfunção erétil é definida como a incapacidade de alcançar ou manter uma ereção peniana satisfatória para uma relação sexual e pode acontecer por causas psicológicas ou orgânicas, podendo esta ser, vascular, neurológica...

Síndrome de tensão musculoesquelética, musculatura laríngea extrínseca e postura corporal: considerações teóricas

Directory of Open Access Journals (Sweden)

Carla Aparecida Cielo

2014-10-01

Full Text Available O tema deste estudo é a Síndrome de tensão musculoesquelética, musculatura laríngea extrínseca e postura corporal. Tem como objetivo descrever, a partir de revisão de literatura,as características da musculatura extrínseca da laringe; postura corporal; Síndrome de tensão musculoesquelética e suas implicações vocais; avaliação e tratamento fisioterapêutico e fonoaudiológico. Foi realizado levantamento bibliográfico dos últimos 13 anos em que foram incluídos artigos cujo objetivo e/ou corpo do texto estivessem em consonância com os objetivos do estudo. A pesquisa foi realizada nos bancos de dados das bases Literatura Latino-Americana e do Caribe em Ciências da Saúde, Biblioteca Regional de Medicina, PublicMedline, Medical Literature Analysis and Retrieval System on Line, Scientific Electronic Library Online e Google Schoolar. Estabeleceram-se relações importantes do âmbito fisioterapêutico e fonoaudiológico, dentre as quais se destacam as relações musculares, posturais e funcionais na sinergia do aparato vocal. Na fisioterapia para redução da tensão muscular, a literatura aponta uso de eletroterapia transcutânea, laser de baixa intensidade, laser acupuntura, crioterapia, bem como terapia manual com tração, massagens, manipulações e mobilizações cervicais, associadas ou não a exercícios, alongamentos, relaxamento isométrico, mobilização assistida dos tecidos moles, exercícios terapêuticos visando à correção e equilíbrio muscular, reeducação respiratória diafragmática e terapia com flexão craniocervical. Na fonoaudiologia, foram encontrados apenas estudos com a manipulação digital da laringe e exercícios de trato vocal semiocluído.

Non-linear quantization error reduction for the temperature measurement subsystem on-board LISA Pathfinder

Science.gov (United States)

Sanjuan, J.; Nofrarias, M.

2018-04-01

Laser Interferometer Space Antenna (LISA) Pathfinder is a mission to test the technology enabling gravitational wave detection in space and to demonstrate that sub-femto-g free fall levels are possible. To do so, the distance between two free falling test masses is measured to unprecedented sensitivity by means of laser interferometry. Temperature fluctuations are one of the noise sources limiting the free fall accuracy and the interferometer performance and need to be known at the ˜10 μK Hz-1/2 level in the sub-millihertz frequency range in order to validate the noise models for the future space-based gravitational wave detector LISA. The temperature measurement subsystem on LISA Pathfinder is in charge of monitoring the thermal environment at key locations with noise levels of 7.5 μK Hz-1/2 at the sub-millihertz. However, its performance worsens by one to two orders of magnitude when slowly changing temperatures are measured due to errors introduced by analog-to-digital converter non-linearities. In this paper, we present a method to reduce this effect by data post-processing. The method is applied to experimental data available from on-ground validation tests to demonstrate its performance and the potential benefit for in-flight data. The analog-to-digital converter effects are reduced by a factor between three and six in the frequencies where the errors play an important role. An average 2.7 fold noise reduction is demonstrated in the 0.3 mHz-2 mHz band.

Laser frequency stabilization and stray light issues for LISA and other future multi-spacecraft missions Project

Data.gov (United States)

National Aeronautics and Space Administration — "The Laser Interferometer Space Antenna (LISA) is a joint NASA/ESA project which will use laser interferometry between drag-free proof masses to measure...

Lisa B Signorello, ScD, ScM | Division of Cancer Prevention

Science.gov (United States)

Lisa Signorello is the Director and Chief of the Cancer Prevention Fellowship Program (CPFP) Branch in the National Cancer Institute's Division of Cancer Prevention. Dr. Signorello served as Deputy Director of the CPFP from August 2014 to November 2017 and came to the NCI after having held academic positions at the Harvard School of Public Health, Harvard Medical School, and Vanderbilt University, as well as having had significant private sector research experience. |

Principles, operations, and expected performance of the LISA Pathfinder charge management system

Energy Technology Data Exchange (ETDEWEB)

Ziegler, T [Astrium GmbH, 88039 Friedrichshafen (Germany); Fichter, W [iFR, Universitaet Stuttgart, Pfaffenwaldring 7a, 70569 Stuttgart (Germany); Schulte, M [Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BZ (United Kingdom); Vitale, S, E-mail: tobias.ziegler@astrium.eads.ne [Department of Physics, University of Trento, 38050 Povo, Trento (Italy)

2009-03-01

The test masses of LISA Pathfinder are free flying and therefore not grounded to the spacecraft by a wire. Because of galactic cosmic rays, solar energetic particles, and unknown microscopic surface effects during initial test mass release, an unacceptable level of absolute charge might be present on the test masses. A charged test mass can endanger transition to high accuracy control modes which are required for science experiments. Furthermore, charged test masses introduce unwanted disturbance accelerations for example due to Coulomb interactions with surrounding conducting surfaces. The charge management system is designed to discharge the test masses up to a tolerable level of absolute charge such that the mission goal can be achieved. It is therefore an essential part of the experiments to be performed with the LISA Technology Package. The paper describes charge management tasks to be performed on board the spacecraft and summarizes the principles of charge measurement and discharge control. An overview of the experiment operations is given where the interconnection of operational charge management system modes and operational modes of the drag-free, suspension and attitude control system is considered. Simulated performance results are presented.

The LISA Pathfinder interferometry-hardware and system testing

Energy Technology Data Exchange (ETDEWEB)

Audley, H; Danzmann, K; MarIn, A Garcia; Heinzel, G; Monsky, A; Nofrarias, M; Steier, F; Bogenstahl, J [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik und Universitaet Hannover, 30167 Hannover (Germany); Gerardi, D; Gerndt, R; Hechenblaikner, G; Johann, U; Luetzow-Wentzky, P; Wand, V [EADS Astrium GmbH, Friedrichshafen (Germany); Antonucci, F [Dipartimento di Fisica, Universita di Trento and INFN, Gruppo Collegato di Trento, 38050 Povo, Trento (Italy); Armano, M [European Space Astronomy Centre, European Space Agency, Villanueva de la Canada, 28692 Madrid (Spain); Auger, G; Binetruy, P [APC UMR7164, Universite Paris Diderot, Paris (France); Benedetti, M [Dipartimento di Ingegneria dei Materiali e Tecnologie Industriali, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Boatella, C, E-mail: antonio.garcia@aei.mpg.de [CNES, DCT/AQ/EC, 18 Avenue Edouard Belin, 31401 Toulouse, Cedex 9 (France)

2011-05-07

Preparations for the LISA Pathfinder mission have reached an exciting stage. Tests of the engineering model (EM) of the optical metrology system have recently been completed at the Albert Einstein Institute, Hannover, and flight model tests are now underway. Significantly, they represent the first complete integration and testing of the space-qualified hardware and are the first tests on an optical system level. The results and test procedures of these campaigns will be utilized directly in the ground-based flight hardware tests, and subsequently during in-flight operations. In addition, they allow valuable testing of the data analysis methods using the MATLAB-based LTP data analysis toolbox. This paper presents an overview of the results from the EM test campaign that was successfully completed in December 2009.

[Adult intestinal malrotation associated with intestinal volvulus].

Science.gov (United States)

Hernando-Almudí, Ernesto; Cerdán-Pascual, Rafael; Vallejo-Bernad, Cristina; Martín-Cuartero, Joaquín; Sánchez-Rubio, María; Casamayor-Franco, Carmen

Intestinal malrotation is a congenital anomaly of the intestinal rotation and fixation, and usually occurs in the neonatal age. Description of a clinical case associated with acute occlusive symptoms. A case of intestinal malrotation is presented in a previously asymptomatic woman of 46 years old with an intestinal obstruction, with radiology and surgical findings showing an absence of intestinal rotation. Intestinal malrotation in adults is often asymptomatic, and is diagnosed as a casual finding during a radiological examination performed for other reasons. Infrequently, it can be diagnosed in adults, associated with an acute abdomen. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

A estimulação russa no fortalecimento da musculatura abdominal Russian stimulation in strengthening abdominal muscle

Directory of Open Access Journals (Sweden)

Evelyne Patrícia Fernandes Lima

2012-06-01

Full Text Available INTRODUÇÃO - A flacidez muscular surge com maior frequência nas mulheres, o que causa fator ruim para a estética corporal. OBJETIVO - Analisar os resultados da corrente russa no fortalecimento da musculatura abdominal. MÉTODOS - Revisão bibliográfica com base nas publicações acessíveis pelas seguintes bases de dados: Medline/Pubmed, Scielo, Lilacs com cruzamento dos descritores corrente russa, flacidez, abdômen. O uso da eletroestimulação age tanto sobre as fibras brancas, que respondem pela velocidade, como também sobre as fibras vermelhas dado à sua sustentação, e ainda sobre as fibras intermediárias. CONCLUSÃO - Os dados publicados mostram a satisfação e êxito do tratamento, enfatizando que a corrente russa favorece o aumento da hipertrofia e força muscular.INTRODUCTION - Muscle weakness appears most often in women, the factor that causes bad esthetics. OBJECTIVE - To analyze the results of the Russian current strengthening the abdominal muscles. METHODS - Literature review based on publications available in the following databases: Medline / Pubmed, Scielo, Lilacs with crossing headings Russian current, sagging, abdomen. The use of electrical stimulation acts both on the white fibers, which account for the speed, but also on the red fibers given their support, and on intermediate fibers. CONCLUSION - The data published show the satisfaction and success of treatment, emphasizing that the Russian current promotes increase of muscle strength and hypertrophy.

Energy transport in mirror machine LISA at electron cyclotron resonance

International Nuclear Information System (INIS)

Cunha Rapozo, C. da; Serbeto, A.; Torres-Silva, H.

1993-01-01

It is shown that a classical transport calculation is adequate to predict the steady state temperature of the RF produced plasma in LISA machine for both large and small resonant volumes. Temperature anisotropy ranging from 55 to 305 was found which was larger for small resonant volume, and the temperature relaxation was larger at large resonant one. This agrees with the fact that there is a Coulomb relaxation ν c which is proportional to T e -3/2 . It is also shown that the fitting parameter alpha is larger for large resonant volume than for small resonant one. (L.C.J.A.)

Simulation of the charging process of the LISA test masses due to solar flares

International Nuclear Information System (INIS)

Vocca, H; Grimani, C; Amico, P; Bosi, L; Marchesoni, F; Punturo, M; Travasso, F; Barone, M; Stanga, R; Vetrano, F; Vicere, A

2004-01-01

Cosmic-ray and solar high energy particles penetrate the LISA experiment test masses. Consequently, an electric charge accumulates in the bodies of the masses, generating spurious Coulomb forces between the masses and the surrounding electrodes. This process increases the noise level of the experiment. We have estimated the amount of charge deposited per second on the LISA test masses by solar flares and primary cosmic-ray protons at solar minimum. The simulation has been carried out with the Fluka Monte Carlo program. A simplified geometry for the experiment has been considered. We have found a net charging rate of 37 ± 1 e + /s for primary protons at solar minimum between 0.1 and 1000 GeV/n. The amount of charge released by a medium-strong solar flare, like that of 16 February 1984, is 10 732 ± 30 e + /s in the energy range 0.1-10 GeV/n. This value increases or decreases by approximately one order of magnitude for strong (weak) solar flares

LISA - a powerful program package for LIstmode and Spectral data Analysis

International Nuclear Information System (INIS)

Oberstedt, A.; Hambsch, F.J.

1994-01-01

LISA is a graphical program package which enables both off-line listmode and spectral data evaluation as well as on-line monitoring while multi-parameter experiments are running. It can be executed on every computer with a UNIX operating system and an X-WINDOW environment, running PV-WAVE from Visual Numerics Incorporation. This package is basically written in the language PV-WAVE CL, but integration of procedures written in the C-language and execution of UNIX shell commands lead to an additional increase of performance. (orig.)

Relativistic analysis of the LISA long range optical links

International Nuclear Information System (INIS)

Chauvineau, Bertrand; Regimbau, Tania; Vinet, Jean-Yves; Pireaux, Sophie

2005-01-01

The joint ESA/NASA LISA mission consists of three spacecraft on heliocentric orbits, flying in a triangular formation of 5 Mkm each side, linked by infrared optical beams. The aim of the mission is to detect gravitational waves in a low frequency band. For properly processing the scientific data, the propagation delays between spacecraft must be accurately known. We thus analyze the propagation of light between spacecraft in order to systematically derive the relativistic effects due to the static curvature of the Schwarzschild space-time in which the spacecraft are orbiting with time-varying light distances. In particular, our analysis allows us to evaluate rigorously the Sagnac effect, and the gravitational (Einstein) redshift

Développement et exploitation d'un simulateur électro-optique pour le futur détecteur spatial à ondes gravitationnelles eLISA

OpenAIRE

Gruning , Pierre

2015-01-01

Gravitational waves will offer a new window to the universe. Their detection by ground based detectors should arrive soon and the future space based interferometer eLISA will allow to do gravitational wave astronomy in order to get unique informations on their sources wether black holes, neutron stars, the Big Bang etc. The effect of a gravitational wave is an extremely weak variation of distance, it will require a very performant detector. That’s why eLISA should reach picometer precision wi...

Massive Black Hole Mergers: Can We "See" what LISA will "Hear"?

Science.gov (United States)

Centrella, Joan

2010-01-01

The final merger of massive black holes produces strong gravitational radiation that can be detected by the space-borne LISA. If the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We will review current efforts to simulate these systems, and discuss possibilities for observing the electromagnetic signals they produce.

Effect of pelvic floor muscle training on labour and newborn outcomes: a randomized controlled trial Efeitos do treinamento da musculatura do assoalho pélvico sobre o parto e recém-nascido: estudo controlado randomizado

Directory of Open Access Journals (Sweden)

Letícia A. R. Dias

2011-12-01

Full Text Available BACKGROUND: The use of the pelvic floor muscle training for urinary incontinence treatment is well established but little is known about its effects in labor and newborn outcomes. OBJECTIVES: To evaluate the effects of antenatal pelvic floor muscle training and strength in labor and newborn outcomes in low-income pregnant women. METHODS: This is a randomized controlled trial that recruited forty-two nulliparous healthy pregnant women aged between 18-36 years old and able to contract the pelvic floor muscles. The participants were included in the study with 20 weeks of gestational age and had their pelvic floor muscles measured by vaginal squeeze pressure. They were randomly allocated into two groups: training group and a non-intervention control group. Then, all participants had their labor and newborn outcomes evaluated through consultation of medical records by a blinded researcher. RESULTS: There were no statistically significant differences between the groups regarding gestational age at birth, type of labor, duration of the second stage of labor, total time of labor, prevalence of laceration, weight and size of the baby, and Apgar score. No correlation was observed between pelvic floor muscle strength and the second stage or the total length of labor. CONCLUSIONS: This randomized controlled trial did not find any effect of pelvic floor muscle training or pelvic floor muscle strength on labor and newborn outcomes.CONTEXTUALIZAÇÃO: O treinamento da musculatura do assoalho pélvico para tratamento da incontinência urinária é bem estabelecida, mas pouco se sabe sobre seus efeitos sobre o parto e o recém-nascido. OBJETIVOS: Avaliar se os desfechos do parto e os resultados dos recém-nascidos são influenciados pelo treinamento e força da musculatura do assoalho pélvico realizados por gestantes de baixa renda. MÉTODOS: Trata-se de um ensaio clínico randomizado que incluiu 42 gestantes nulíparas de baixo risco, com idade entre 18 e 36

Nested-PCR and a new ELISA-based NovaLisa test kit for malaria diagnosis in an endemic area of Thailand.

Science.gov (United States)

Thongdee, Pimwan; Chaijaroenkul, Wanna; Kuesap, Jiraporn; Na-Bangchang, Kesara

2014-08-01

Microscopy is considered as the gold standard for malaria diagnosis although its wide application is limited by the requirement of highly experienced microscopists. PCR and serological tests provide efficient diagnostic performance and have been applied for malaria diagnosis and research. The aim of this study was to investigate the diagnostic performance of nested PCR and a recently developed an ELISA-based new rapid diagnosis test (RDT), NovaLisa test kit, for diagnosis of malaria infection, using microscopic method as the gold standard. The performance of nested-PCR as a malaria diagnostic tool is excellent with respect to its high accuracy, sensitivity, specificity, and ability to discriminate Plasmodium species. The sensitivity and specificity of nested-PCR compared with the microscopic method for detection of Plasmodium falciparum, Plasmodium vivax, and P. falciparum/P. vivax mixed infection were 71.4 vs 100%, 100 vs 98.7%, and 100 vs 95.0%, respectively. The sensitivity and specificity of the ELISA-based NovaLisa test kit compared with the microscopic method for detection of Plasmodium genus were 89.0 vs 91.6%, respectively. NovaLisa test kit provided comparable diagnostic performance. Its relatively low cost, simplicity, and rapidity enables large scale field application.

On-orbit alignment and diagnostics for the LISA Technology Package

International Nuclear Information System (INIS)

MarIn, A F GarcIa; Wand, V; Steier, F; Cervantes, F Guzman; Bogenstahl, J; Jennrich, O; Heinzel, G; Danzmann, K

2006-01-01

This paper presents a procedure to perform fully autonomous on-orbit alignment of the interferometer on board the LISA Technology Package (LTP). LTP comprises two free-floating test masses as inertial sensors that additionally serve as end mirrors of a set of interferometers. From the output signals of the interferometers, a subset has been selected to obtain alignment information of the test masses. Based on these signals, an alignment procedure was developed and successfully tested on the engineering model of the optical bench. Furthermore, operation procedures for the characterization of critical on-orbit properties of the optical metrology system (e.g. fibre noise) have been established

Commissioning and operating experience with the LISA superconducting accelerator

International Nuclear Information System (INIS)

Castellano, M.; Ferrario, M.; Minestrini, M.; Patteri, P.; Tazzioli, F.; Kulinski, S.

1996-06-01

The commissioning of the LISA superconducting (SC) RF electron linac at INFN Frascati Laboratories has been concluded although, due to a change in program priorities, the full possibilities of the machine have not been exploited. In this report the authors illustrate the results achieved so far and the difficulties encountered in commissioning, with the hope that this material might be some of help to those who intend to start the enterprise of building a SC linac in a non specialized environment. The part concerning the SC system is particularly stressed, but a relevant attention is also devoted to the traditional room temperature injector, the proper setting of which is fundamental to achieving the high beam quality that such a machine allows

A musculatura epaxial e a fibrose epidural na compressão medular em cães submetidos à laminectomia dorsal modificada

Directory of Open Access Journals (Sweden)

Diego V. Beckmann

2010-02-01

Full Text Available O objetivo deste experimento foi isolar a musculatura epaxial da medula espinhal de cães submetidos à laminectomia dorsal modificada (LDM e averiguar se os músculos influenciaram na formação da fibrose epidural, na compressão medular e no aparecimento dos sinais neurológicos. Para isso, dez cães hígidos foram submetidos à LDM entre as vértebras T13 e L1 e distribuídos aleatoriamente em dois grupos denominados controle (I onde a medula espinhal permaneceu exposta sem a presença de implante, e tratado (IIonde foi colocado um im-plante a base de alumínio entre a musculatura epaxial adjacente e a medula espinhal exposta pela LDM. As avaliações constaram de exames neurológicos diários até 180 dias de pós-operatório (PO; mielografia, decorridos 15, 30 e 60 dias de PO; e avaliação macroscópica mediante a reintervenção cirúrgica. Não houve diferença durante as avaliações neurológicas. Aos 15 dias de PO, foi verificado na mielografia, que o grau de compressão da linha de contraste foi maior no grupo tratado (PThe purpose of this study was to isolate the adjacent epaxial musculature from exposed spinal cord by modified dorsal laminectomy in dogs with aluminum implant and to verify whether the muscles contribute to form epidural fibrosis, spinal cord compression, and development of neurological signs. Ten dogs were submitted to modified dorsal laminectomy between T13 and L1 and then distributed along two groups. Dogs in the group 1 remained with the spinal cord exposed without the implant; dogs in the group 2 had an aluminum implant inserted between the epaxial muscles and the exposed spinal cord. Neurological examination was daily performed until 180 days post surgery. Additionally, myelography at 15, 30, and 60 days post surgery and macroscopic evaluation of the implant at six months post surgery were done. There was no difference between groups in the neurological examination. A statistical difference in the degree of

Playing Harry Potter: Essays and interviews on fandom and performance, edited by Lisa S. Brenner

Directory of Open Access Journals (Sweden)

Abigail De Kosnik

2016-09-01

Full Text Available Lisa S. Brenner, editor. Playing Harry Potter: Essays and interviews on fandom and performance. Jefferson, NC: McFarland, 2015, paperback, $29.95 (238p ISBN 978-0-7864-9657-0; e-book $14.43 (5374 KB ISBN 978-1-4766-2136-4, ASIN B012E9G0R6.

The effects of orbital motion on LISA time delay interferometry

International Nuclear Information System (INIS)

Cornish, Neil J; Hellings, Ronald W

2003-01-01

In an effort to eliminate laser phase noise in laser interferometer spaceborne gravitational wave detectors, several combinations of signals have been found that allow the laser noise to be cancelled out while gravitational wave signals remain. This process is called time delay interferometry (TDI). In the papers that defined the TDI variables, their performance was evaluated in the limit that the gravitational wave detector is fixed in space. However, the performance depends on certain symmetries in the armlengths that are available if the detector is fixed in space, but that will be broken in the actual rotating and flexing configuration produced by the LISA orbits. In this paper we investigate the performance of these TDI variables for the real LISA orbits. First, addressing the effects of rotation, we verify Daniel Shaddock's result that the Sagnac variables α (t), β (t) and γ (t) will not cancel out the laser phase noise, and we also find the same result for the symmetric Sagnac variable ζ (t). The loss of the latter variable would be particularly unfortunate since this variable also cancels out gravitational wave signal, allowing instrument noise in the detector to be isolated and measured. Fortunately, we have found a set of more complicated TDI variables, which we call Δ Sagnac variables, one of which accomplishes the same goal as ζ (t) to good accuracy. Finally, however, as we investigate the effects of the flexing of the detector arms due to non-circular orbital motion, we show that all variables, including the interferometer variables, X(t), Y(t) and Z(t), which survive the rotation-induced loss of direction symmetry, will not completely cancel laser phase noise when the armlengths are changing with time. This unavoidable problem will place a stringent requirement on laser stability of ∼5 Hz Hz -1/2

Intestinal Cancer

Science.gov (United States)

... connects your stomach to your large intestine. Intestinal cancer is rare, but eating a high-fat diet ... increase your risk. Possible signs of small intestine cancer include Abdominal pain Weight loss for no reason ...

Science with the space-based interferometer eLISA. III: probing the expansion of the universe using gravitational wave standard sirens

Energy Technology Data Exchange (ETDEWEB)

Tamanini, Nicola; Caprini, Chiara [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Barausse, Enrico [Sorbonne Universités, UPMC Université Paris 6, UMR 7095, Institut d' Astrophysique de Paris, 98 bis Bd Arago, 75014 Paris (France); Sesana, Alberto [School of Physics and Astronomy, The University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Klein, Antoine [Department of Physics and Astronomy, The University of Mississippi, University, MS 38677 (United States); Petiteau, Antoine, E-mail: nicola.tamanini@cea.fr, E-mail: chiara.caprini@cea.fr, E-mail: barausse@iap.fr, E-mail: asesana@star.sr.bham.ac.uk, E-mail: aklein@physics.montana.edu, E-mail: antoine.petiteau@apc.univ-paris7.fr [APC, Université Paris Diderot, Observatoire de Paris, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

2016-04-01

We investigate the capability of various configurations of the space interferometer eLISA to probe the late-time background expansion of the universe using gravitational wave standard sirens. We simulate catalogues of standard sirens composed by massive black hole binaries whose gravitational radiation is detectable by eLISA, and which are likely to produce an electromagnetic counterpart observable by future surveys. The main issue for the identification of a counterpart resides in the capability of obtaining an accurate enough sky localisation with eLISA. This seriously challenges the capability of four-link (2 arm) configurations to successfully constrain the cosmological parameters. Conversely, six-link (3 arm) configurations have the potential to provide a test of the expansion of the universe up to z ∼ 8 which is complementary to other cosmological probes based on electromagnetic observations only. In particular, in the most favourable scenarios, they can provide a significant constraint on H{sub 0} at the level of 0.5%. Furthermore, (Ω{sub M}, Ω{sub Λ}) can be constrained to a level competitive with present SNIa results. On the other hand, the lack of massive black hole binary standard sirens at low redshift allows to constrain dark energy only at the level of few percent.

Intestinal tract diseases

International Nuclear Information System (INIS)

Rozenshtraukh, L.S.

1985-01-01

Roentgenoanatomy and physiology of the small intestine are described. Indications for radiological examinations and their possibilities in the diagnosis of the small intestine diseases are considered.Congenital anomalies and failures in the small intestine development, clinical indications and diagnosis methods for the detection of different aetiology enteritis are described. Characteristics of primary malabsorption due to congenital or acquired inferiority of the small intestine, is provided. Radiological picture of intestinal allergies is described. Clinical, morphological, radiological pictures of Crohn's disease are considered in detail. Special attention is paid to the frequency of primary and secondary tuberculosis of intestinal tract. The description of clinical indications and frequency of benign and malignant tumours of the small intestine, methods for their diagnosis are given. Radiological pictures of parasitogenic and rare diseases of the small intestine are presented. Changes in the small intestine as a result of its reaction to pathological processes, developing in other organs and systems of the organism, are described

LISA Pathfinder drag-free control and system implications

International Nuclear Information System (INIS)

Fichter, Walter; Gath, Peter; Vitale, Stefano; Bortoluzzi, Daniele

2005-01-01

The top-level requirement of the LISA Pathfinder mission is the verification of pure relative free fall between two test masses with an accuracy of about 3 x 10 -14 m s -2 Hz -1/2 in a measurement bandwidth between 1 mHz and 30 mHz. The drag-free control system is one of the key technology elements that shall be verified. Its design is strongly connected to the overall system and experimental design, in particular, via the following issues: the differential test mass motion and thus the science measurements depend on the control system; design constraints, such as negative stiffness of test masses and electrostatic actuation cross-talk, have an impact on science and control system performance; derived requirements for control system components, in particular, the micro-propulsion system, must be within reasonable and feasible limits. In this paper, the control design approach is outlined and the system-related issues are addressed

Selective metallization of polymers using laser induced surface activation (LISA)—characterization and optimization of porous surface topography

DEFF Research Database (Denmark)

Zhang, Yang; Hansen, Hans Nørgaard; De Grave, Arnaud

2011-01-01

Laser induced selective activation (LISA) is a molded interconnected devices technique for selective metallization of polymers. On the working piece, only the laser-machined area can be metalized in the subsequent plating. The principle of the technology is introduced. Surface analysis was perfor...

Theory and modelling of the magnetic field measurement in LISA PathFinder

Energy Technology Data Exchange (ETDEWEB)

Diaz-Aguilo, M; Garcia-Berro, E [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, 08860 Castelldefels (Spain); Lobo, A, E-mail: marc.diaz.aguilo@fa.upc.ed [Institut d' Estudis Espacials de Catalunya, c/Gran Capita 2-4, Edif. Nexus 104, 08034 Barcelona (Spain)

2010-02-07

The magnetic diagnostics subsystem of the LISA Technology Package (LTP) on board the LISA PathFinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at their respective positions. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses, and hence an interpolation method must be designed and implemented to obtain the values of the magnetic field at these positions. However, such an interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable while, on the other hand, the number of magnetometer channels do not provide sufficient data to go beyond the linear approximation. We describe an alternative method to address this issue, by means of neural network algorithms. The key point in this approach is the ability of neural networks to learn from suitable training data representing the behaviour of the magnetic field. Despite the relatively large distance between the test masses and the magnetometers, and the insufficient number of data channels, we find that our artificial neural network algorithm is able to reduce the estimation errors of the field and gradient down to levels below 10%, a quite satisfactory result. Learning efficiency can be best improved by making use of data obtained in on-ground measurements prior to mission launch in all relevant satellite locations and in real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

Theory and modelling of the magnetic field measurement in LISA PathFinder

International Nuclear Information System (INIS)

Diaz-Aguilo, M; Garcia-Berro, E; Lobo, A

2010-01-01

The magnetic diagnostics subsystem of the LISA Technology Package (LTP) on board the LISA PathFinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at their respective positions. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses, and hence an interpolation method must be designed and implemented to obtain the values of the magnetic field at these positions. However, such an interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable while, on the other hand, the number of magnetometer channels do not provide sufficient data to go beyond the linear approximation. We describe an alternative method to address this issue, by means of neural network algorithms. The key point in this approach is the ability of neural networks to learn from suitable training data representing the behaviour of the magnetic field. Despite the relatively large distance between the test masses and the magnetometers, and the insufficient number of data channels, we find that our artificial neural network algorithm is able to reduce the estimation errors of the field and gradient down to levels below 10%, a quite satisfactory result. Learning efficiency can be best improved by making use of data obtained in on-ground measurements prior to mission launch in all relevant satellite locations and in real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

Intestinal Surgery.

Science.gov (United States)

Desrochers, André; Anderson, David E

2016-11-01

A wide variety of disorders affecting the intestinal tract in cattle may require surgery. Among those disorders the more common are: intestinal volvulus, jejunal hemorrhage syndrome and more recently the duodenal sigmoid flexure volvulus. Although general principles of intestinal surgery can be applied, cattle has anatomical and behavior particularities that must be known before invading the abdomen. This article focuses on surgical techniques used to optimize outcomes and discusses specific disorders of small intestine. Diagnoses and surgical techniques presented can be applied in field conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Metal-amplified Density Assays, (MADAs), including a Density-Linked Immunosorbent Assay (DeLISA).

Science.gov (United States)

Subramaniam, Anand Bala; Gonidec, Mathieu; Shapiro, Nathan D; Kresse, Kayleigh M; Whitesides, George M

2015-02-21

This paper reports the development of Metal-amplified Density Assays, or MADAs - a method of conducting quantitative or multiplexed assays, including immunoassays, by using Magnetic Levitation (MagLev) to measure metal-amplified changes in the density of beads labeled with biomolecules. The binding of target analytes (i.e. proteins, antibodies, antigens) to complementary ligands immobilized on the surface of the beads, followed by a chemical amplification of the binding in a form that results in a change in the density of the beads (achieved by using gold nanoparticle-labeled biomolecules, and electroless deposition of gold or silver), translates analyte binding events into changes in density measureable using MagLev. A minimal model based on diffusion-limited growth of hemispherical nuclei on a surface reproduces the dynamics of the assay. A MADA - when performed with antigens and antibodies - is called a Density-Linked Immunosorbent Assay, or DeLISA. Two immunoassays provided a proof of principle: a competitive quantification of the concentration of neomycin in whole milk, and a multiplexed detection of antibodies against Hepatitis C virus NS3 protein and syphilis T. pallidum p47 protein in serum. MADAs, including DeLISAs, require, besides the requisite biomolecules and amplification reagents, minimal specialized equipment (two permanent magnets, a ruler or a capillary with calibrated length markings) and no electrical power to obtain a quantitative readout of analyte concentration. With further development, the method may be useful in resource-limited or point-of-care settings.

Impact of Intestinal Microbiota on Intestinal Luminal Metabolome

Science.gov (United States)

Matsumoto, Mitsuharu; Kibe, Ryoko; Ooga, Takushi; Aiba, Yuji; Kurihara, Shin; Sawaki, Emiko; Koga, Yasuhiro; Benno, Yoshimi

2012-01-01

Low–molecular-weight metabolites produced by intestinal microbiota play a direct role in health and disease. In this study, we analyzed the colonic luminal metabolome using capillary electrophoresis mass spectrometry with time-of-flight (CE-TOFMS) —a novel technique for analyzing and differentially displaying metabolic profiles— in order to clarify the metabolite profiles in the intestinal lumen. CE-TOFMS identified 179 metabolites from the colonic luminal metabolome and 48 metabolites were present in significantly higher concentrations and/or incidence in the germ-free (GF) mice than in the Ex-GF mice (p metabolome and a comprehensive understanding of intestinal luminal metabolome is critical for clarifying host-intestinal bacterial interactions. PMID:22724057

Small Intestine Disorders

Science.gov (United States)

... disease Crohn's disease Infections Intestinal cancer Intestinal obstruction Irritable bowel syndrome Ulcers, such as peptic ulcer Treatment of disorders of the small intestine depends on the cause.

The low emittance 2.5 GeV synchrotron light source LISA

International Nuclear Information System (INIS)

Einfeld, D.; Hormes, J.; Husmann, D.

1992-01-01

LISA, a Light source for Industrial and Scientific Applications, has been proposed. Due to the intention to use the source above all for the LIGA (Lithographie, Galvanik, Abformtechnik) method to produce micromechanical structures, the critical wavelength of the synchrotron radiation spectrum is foreseen to be 0.2 nm. Therefore, the electron energy and the field strength of the ring dipoles have been chosen to be 2.5 GeV and 1.5 T, respectively. It is proposed to make use of a modified 'quadrupole ben achromat' (QBA) lattice. The novel feature of this lattice is the application of two types of bending magnets of different lengths, i.e. different bending angels. (author) 9 refs.; 6 figs.; 1 tab

Strong lensing of gravitational waves as seen by LISA.

Science.gov (United States)

Sereno, M; Sesana, A; Bleuler, A; Jetzer, Ph; Volonteri, M; Begelman, M C

2010-12-17

We discuss strong gravitational lensing of gravitational waves from the merging of massive black hole binaries in the context of the LISA mission. Detection of multiple events would provide invaluable information on competing theories of gravity, evolution and formation of structures and, possibly, constraints on H0 and other cosmological parameters. Most of the optical depth for lensing is provided by intervening massive galactic halos, for which wave optics effects are negligible. Probabilities to observe multiple events are sizable for a broad range of formation histories. For the most optimistic models, up to ≲ 4 multiple events with a signal to noise ratio ≳ 8 are expected in a 5-year mission. Chances are significant even for conservative models with either light (≲ 60%) or heavy (≲ 40%) seeds. Because of lensing amplification, some intrinsically too faint signals are brought over threshold (≲ 2 per year).

After-dinner speech: the path of LISA to become ‘L3’

Science.gov (United States)

Huber, M. C. E.

2017-05-01

We describe the state of fundamental-physics experiments in space in the mid 1980s on both sides of the Atlantic, and then follow the development of this field within ESA’s Scientific Programme. The special case of LISA — a fundamental physics experiment in space also supported by astronomers, and now, following the ground-based detection of gravitational waves, the means to extend the observable spectrum of such waves towards lower frequencies and long-lasting signals — is then followed in its rise to become the ‘Large Project L3’ of ESA.

Metaphors Expressing Emotions in Lisa Kleypas’s Rainshadow Road Novel

Directory of Open Access Journals (Sweden)

Novi Liana Ko

2014-05-01

Full Text Available Metaphors have been always interesting to explore since they are able to represent many things, one of which is feelings. Article examined the metaphorical sentences which expressed emotions found in Lisa Kleypas’s the Rainshadow Road. Library research was conducted to find the kinds of emotions which were expressed by the metaphorical sentences. It was also done to figure out what the metaphors refered to. Another objective was to reveal the most dominant emotion which appeared through the metaphors expressed in the novel. The analysis used metaphor theory to compare the dictionary meaning and the metaphorical one. The result shows that there are various emotions which are expressed through the metaphorical sentences. Happiness is found as the most dominant emotion which appears in the novel.

Simple Enough--Even for Web Virgins: Lisa Mitten's Access to Native American Web Sites. Web Site Review Essay.

Science.gov (United States)

Belgarde, Mary Jiron

1998-01-01

A mixed-blood Mohawk urban Indian and university librarian, Lisa Mitten provides access to Web sites with solid information about American Indians. Links are provided to 10 categories--Native nations, Native organizations, Indian education, Native media, powwows and festivals, Indian music, Native arts, Native businesses, and Indian-oriented home…

Compact laser interferometer for translation and tilt measurement as optical readout for the LISA inertial sensor

Science.gov (United States)

Schuldt, Thilo; Gohlke, Martin; Weise, Dennis; Johann, Ulrich; Peters, Achim; Braxmaier, Claus

2007-10-01

The space mission LISA (Laser Interferometer Space Antenna) aims at detecting gravitational waves in the frequency range 30 μ Hz to 1Hz. Free flying proof masses inside the satellites act as inertial sensors and represent the end mirrors of the interferometer. In the current baseline design, LISA utilizes an optical readout of the position and tilt of the proof mass with respect to the satellite housing. This readout must have ~ 5pm/√Hz sensitivity for the translation measurement (for frequencies above 2.8mHz with an ƒ -2 relaxation down to 30 μHz) and ~ 10 nrad/√Hz sensitivity for the tilt measurement (for frequencies above 0.1mHz with an ƒ -1 relaxation down to 30 μHz). The University of Applied Sciences Konstanz (HTWG) - in collaboration with Astrium GmbH, Friedrichshafen, and the Humboldt-University Berlin - therefore develops a highly symmetric heterodyne interferometer implementing differential wavefront sensing for the tilt measurement. We realized a mechanically highly stable and compact setup. In a second, improved setup we measured initial noise levels below 5 pm/√Hz and 10 nrad/√Hz, respectively, for frequencies above 10mHz.

Playing Harry Potter: Essays and interviews on fandom and performance, edited by Lisa S. Brenner [book review

Directory of Open Access Journals (Sweden)

Abigail De Kosnik

2016-09-01

Full Text Available Review of Lisa S. Brenner, editor. Playing Harry Potter: Essays and interviews on fandom and performance. Jefferson, NC: McFarland, 2015, paperback, $29.95 (238p ISBN 978-0-7864-9657-0, e-book $14.43 (5374 KB ISBN 978-1-4766-2136-4, ASIN B012E9G0R6.

Elimination of vibrio cholerae in lisa fillets (Mugil cephalus) by gamma radiation

International Nuclear Information System (INIS)

Torres, Z.

1999-03-01

The elimination of Vibrio cholerae 01 biotype El Tor (1,87 8 cuf/g) in fresh lisa fillets (Mugil cephalus) with radiation doses of 0 and 0,5 kGy was investigated. Furthermore, in order to evaluate physical, chemical and sensory changes, doses of 1,2,3 and 4 kGy were applied to non inoculated fillets of lisa. Finally, D 10 for Vibrio cholerae was determined in a saline suspension (5,2x10 8 cfu/ml) based on the Most Probable Number (MPN) method and radiation doses of 0,5, 0,75, 1,0, 1,25 and 1,5 kGy. D value found in a 1,87 8 cfu/g concentration of fillet was 0,13 kGy. Humidity, protein, fat and ash contents were not affected significantly and remained around 73 to 75,5, 3,8 to 4,2 and 1% respectively. Control samples showed a 'drip' variation ranging between 0,82 and 0,88% and a N-BVT variation between 1,77 and 1,56, 0,89 and 1,99, 2,13 and 2,47, 1,86 and 2,10%, and a N-BVT variation between 17,79 and 30,16, 16,37 and 26,88 16,33 and 25,12, 15,31 and 33,54 mg N/100 g, respectively. The highest life span for the appearance characteristic was obtained by control samples (23 days) and the lowest by samples radiated at 3 and 4 kGy (28 days). 4 kGy dose resulted in organoleptic changes perceived by panelists during tasting of cooked fish. D 10 found in a saline suspension was 0,13 kGy

Efeitos da crioterapia e facilitação neuromuscular proprioceptiva sobre a força muscular nas musculaturas flexora e extensora de joelho Effects of cryotherapy and proprioceptive neuromuscular facilitation on muscle strength at the flexor and extensor muscles of the knee

Directory of Open Access Journals (Sweden)

Daiana Moreira Mortari

2009-12-01

Full Text Available As musculaturas flexora e extensora do joelho são freqüentemente lesionadas devido a um desequilíbrio entre esses grupos. Recursos térmicos, como a crioterapia, e técnicas de alongamento, como a técnica mantém-relaxa da facilitação neuromuscular proprioceptiva (FNP, influenciam a flexibilidade e força muscular, proporcionando maior homogeneidade entre essas musculaturas e diminuindo a incidência de lesões. Este estudo objetivou verificar os efeitos da crioterapia e da FNP sobre a força das musculaturas flexora e extensora de joelho. A amostra foi composta por 18 mulheres com idade entre 18 e 24 anos, não-praticantes de atividade física regular, divididas em dois grupos: um submetido a crioterapia e o outro à técnica mantém-relaxa da FNP. Antes e após uma sessão de aplicação das técnicas foi feita avaliação isocinética. A aplicação da técnica mantém-relaxa provocou aumento da força em ambas as musculaturas em ambos os membros, atingindo nível de significância nos flexores do membro inferior direito (p=0,04. A crioterapia diminuiu a força dos extensores e exerceu efeito contrário sobre os flexores, tendo gerado aumento significativo nos flexores do membro inferior direito (p=0,035. Quando comparadas as técnicas, a técnica mantém-relaxa gerou maiores valores de pico de torque, principalmente nos extensores do membro inferior esquerdo (p=0,042. Conclui-se que a técnica mantém-relaxa da FNP gerou maiores valores no pico de torque em relação à crioterapia.Knee extensor and flexor muscles are often injured due to an imbalance between these groups, which may lead to a deficit in muscle performance. Thermal resources, such as cryotherapy, and stretching techniques, such as the "hold-relax" of proprioceptive neuromuscular facilitation (PNF, influence flexibility and muscle strength and may reduce the chances of muscle tendon injuries. The aim of the study was to verify the effects of cryotherapy and of the PNF

The Contributions of Human Mini-Intestines to the Study of Intestinal Physiology and Pathophysiology.

Science.gov (United States)

Yu, Huimin; Hasan, Nesrin M; In, Julie G; Estes, Mary K; Kovbasnjuk, Olga; Zachos, Nicholas C; Donowitz, Mark

2017-02-10

The lack of accessibility to normal and diseased human intestine and the inability to separate the different functional compartments of the intestine even when tissue could be obtained have held back the understanding of human intestinal physiology. Clevers and his associates identified intestinal stem cells and established conditions to grow "mini-intestines" ex vivo in differentiated and undifferentiated conditions. This pioneering work has made a new model of the human intestine available and has begun making contributions to the understanding of human intestinal transport in normal physiologic conditions and the pathophysiology of intestinal diseases. However, this model is reductionist and lacks many of the complexities of normal intestine. Consequently, it is not yet possible to predict how great the advances using this model will be for understanding human physiology and pathophysiology, nor how the model will be modified to include multiple other intestinal cell types and physical forces necessary to more closely approximate normal intestine. This review describes recent studies using mini-intestines, which have readdressed previously established models of normal intestinal transport physiology and newly examined intestinal pathophysiology. The emphasis is on studies with human enteroids grown either as three-dimensional spheroids or two-dimensional monolayers. In addition, comments are provided on mouse studies in cases when human studies have not yet been described.

Massive Black Hole Mergers: Can we see what LISA will hear?

Science.gov (United States)

Centrella, Joan

2009-01-01

Coalescing massive black hole binaries are formed when galaxies merge. The final stages of this coalescence produce strong gravitational wave signals that can be detected by the space-borne LISA. When the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a first step towards this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We report on the results of these initial simulations and discuss their likely importance for future hydrodynamical simulations.

eLISA Telescope In-field Pointing and Scattered Light Study

Science.gov (United States)

Livas, J.; Sankar, S.; West, G.; Seals, L.; Howard, J.; Fitzsimons, E.

2017-05-01

The orbital motion of the three spacecraft that make up the eLISA Observatory constellation causes long-arm line of sight variations of approximately ± one degree over the course of a year. The baseline solution is to package the telescope, the optical bench, and the gravitational reference sensor (GRS) into an optical assembly at each end of the measurement arm, and then to articulate the assembly. An optical phase reference is exchanged between the moving optical benches with a single mode optical fiber (“backlink” fiber). An alternative solution, referred to as in-field pointing, embeds a steering mirror into the optical design, fixing the optical benches and eliminating the backlink fiber, but requiring the additional complication of a two-stage optical design for the telescope. We examine the impact of an in-field pointing design on the scattered light performance.

Interferometry for the LISA technology package (LTP) aboard SMART-2

International Nuclear Information System (INIS)

Heinzel, G; Braxmaier, C; Schilling, R; Ruediger, A; Robertson, D; Plate, M te; Wand, V; Arai, K; Johann, U; Danzmann, K

2003-01-01

The interferometer of the LISA technology package (LTP) on SMART-2 is needed to verify the performance of the gravitational sensors by monitoring the distance between two test masses with a noise level of 10 pm Hz -1/2 between 3 mHz and 30 mHz. It must continuously track the motion of the test mass distance while that distance changes by many μm with a speed of up to 20 μm s -1 , without losing track of the sign of the motion and without exerting any influence on the test masses that might lead to a motion above that level. As a result of a detailed comparison study, a heterodyne Mach-Zehnder interferometer was selected as the baseline for the SMART-2 mission. Its design and expected performance are described in this paper

Intestinal Lymphangiectasia

Science.gov (United States)

... Overview of Crohn Disease Additional Content Medical News Intestinal Lymphangiectasia (Idiopathic Hypoproteinemia) By Atenodoro R. Ruiz, Jr., MD, ... Overview of Malabsorption Bacterial Overgrowth Syndrome Celiac Disease Intestinal ... Intolerance Short Bowel Syndrome Tropical Sprue Whipple ...

Intestinal parasites : associations with intestinal and systemic inflammation

NARCIS (Netherlands)

Zavala, Gerardo A; García, Olga P; Camacho, Mariela; Ronquillo, Dolores; Campos-Ponce, Maiza; Doak, Colleen; Polman, Katja; Rosado, Jorge L

2018-01-01

AIMS: Evaluate associations between intestinal parasitic infection with intestinal and systemic inflammatory markers in school-aged children with high rates of obesity. METHODS AND RESULTS: Plasma concentrations of CRP, leptin, TNF-α, IL-6 and IL-10 were measured as systemic inflammation markers and

Novel Payload Architectures for LISA

Science.gov (United States)

Johann, Ulrich A.; Gath, Peter F.; Holota, Wolfgang; Schulte, Hans Reiner; Weise, Dennis

2006-11-01

As part of the current LISA Mission Formulation Study, and based on prior internal investigations, Astrium Germany has defined and preliminary assessed novel payload architectures, potentially reducing overall complexity and improving budgets and costs. A promising concept is characterized by a single active inertial sensor attached to a single optical bench and serving both adjacent interferometer arms via two rigidly connected off-axis telescopes. The in-plane triangular constellation ``breathing angle'' compensation is accomplished by common telescope in-field of view pointing actuation of the transmit/received beams line of sight. A dedicated actuation mechanism located on the optical bench is required in addition to the on bench actuators for differential pointing of the transmit and receive direction perpendicular to the constellation plane. Both actuators operate in a sinusoidal yearly period. A technical challenge is the actuation mechanism pointing jitter and the monitoring and calibration of the laser phase walk which occurs while changing the optical path inside the optical assembly during re-pointing. Calibration or monitoring of instrument internal phase effects e.g. by a laser metrology truss derived from the existing interferometry is required. The architecture exploits in full the two-step interferometry (strap down) concept, separating functionally inter spacecraft and intra-spacecraft interferometry (reference mass laser metrology degrees of freedom sensing). The single test mass is maintained as cubic, but in free-fall in the lateral degrees of freedom within the constellation plane. Also the option of a completely free spherical test mass with full laser interferometer readout has been conceptually investigated. The spherical test mass would rotate slowly, and would be allowed to tumble. Imperfections in roundness and density would be calibrated from differential wave front sensing in a tetrahedral arrangement, supported by added attitude

Intestinal Obstruction

Science.gov (United States)

... Colostomy ) is required to relieve an obstruction. Understanding Colostomy In a colostomy, the large intestine (colon) is cut. The part ... 1 What Causes Intestinal Strangulation? Figure 2 Understanding Colostomy Gastrointestinal Emergencies Overview of Gastrointestinal Emergencies Abdominal Abscesses ...

Amebiasis intestinal Intestinal amebiasis

Directory of Open Access Journals (Sweden)

JULIO CÉSAR GÓMEZ

2007-03-01

Full Text Available Entamoeba histolytica es el patógeno intestinal más frecuente en nuestro medio -después de Giardia lamblia-, una de las principales causas de diarrea en menores de cinco años y la cuarta causa de muerte en el mundo debida a infección por protozoarios. Posee mecanismos patogénicos complejos que le permiten invadir la mucosa intestinal y causar colitis amebiana. El examen microscópico es el método más usado para su identificación pero la existencia de dos especies morfológicamente iguales, una patógena ( E. histolytica y una no patógena ( Entamoeba dispar, ha llevado al desarrollo de otros métodos de diagnóstico. El acceso al agua potable y los servicios sanitarios adecuados, un tratamiento médico oportuno y el desarrollo de una vacuna, son los ejes para disminuir la incidencia y mortalidad de esta entidad.Entamoeba histolytica is the most frequent intestinal pathogen seen in our country, after Giardia lamblia, being one of the main causes of diarrhea in children younger than five years of age, and the fourth leading cause of death due to infection for protozoa in the world. It possesses complex pathogenic mechanisms that allow it to invade the intestinal mucosa, causing amoebic colitis. Microscopy is the most used method for its identification, but the existence of two species morphologically identical, the pathogen one ( E. histolytica, and the non pathogen one ( E. dispar, have taken to the development of other methods of diagnosis. The access to drinkable water and appropriate sanitary services, an opportune medical treatment, and the development of a vaccine are the axes to diminish the incidence and mortality of this entity.

Intestinal Leiomyositis: A Cause of Chronic Intestinal Pseudo-Obstruction in 6 Dogs.

Science.gov (United States)

Zacuto, A C; Pesavento, P A; Hill, S; McAlister, A; Rosenthal, K; Cherbinsky, O; Marks, S L

2016-01-01

Intestinal leiomyositis is a suspected autoimmune disorder affecting the muscularis propria layer of the gastrointestinal tract and is a cause of chronic intestinal pseudo-obstruction in humans and animals. To characterize the clinical presentation, histopathologic features, and outcome of dogs with intestinal leiomyositis in an effort to optimize treatment and prognosis. Six client-owned dogs. Retrospective case series. Medical records were reviewed to describe signalment, clinicopathologic and imaging findings, histopathologic diagnoses, treatment, and outcome. All biopsy specimens were reviewed by a board-certified pathologist. Median age of dogs was 5.4 years (range, 15 months-9 years). Consistent clinical signs included vomiting (6/6), regurgitation (2/6), and small bowel diarrhea (3/6). Median duration of clinical signs before presentation was 13 days (range, 5-150 days). Diagnostic imaging showed marked gastric distension with dilated small intestines in 4/6 dogs. Full-thickness intestinal biopsies were obtained in all dogs by laparotomy. Histopathology of the stomach and intestines disclosed mononuclear inflammation, myofiber degeneration and necrosis, and fibrosis centered within the region of myofiber loss in the intestinal muscularis propria. All dogs received various combinations of immunomodulatory and prokinetic treatment, antimicrobial agents, antiemetics, and IV fluids, but none of the dogs showed a clinically relevant improvement with treatment. Median survival was 19 days after diagnosis (range, 3-270 days). Intestinal leiomyositis is a cause of intestinal pseudo-obstruction and must be diagnosed by full-thickness intestinal biopsy. This disease should be considered in dogs with acute and chronic vomiting, regurgitation, and small bowel diarrhea. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

The intestinal complement system in inflammatory bowel disease: Shaping intestinal barrier function.

Science.gov (United States)

Sina, Christian; Kemper, Claudia; Derer, Stefanie

2018-06-01

The complement system is part of innate sensor and effector systems such as the Toll-like receptors (TLRs). It recognizes and quickly systemically and/or locally respond to microbial-associated molecular patterns (MAMPs) with a tailored defense reaction. MAMP recognition by intestinal epithelial cells (IECs) and appropriate immune responses are of major importance for the maintenance of intestinal barrier function. Enterocytes highly express various complement components that are suggested to be pivotal for proper IEC function. Appropriate activation of the intestinal complement system seems to play an important role in the resolution of chronic intestinal inflammation, while over-activation and/or dysregulation may worsen intestinal inflammation. Mice deficient for single complement components suffer from enhanced intestinal inflammation mimicking the phenotype of patients with chronic inflammatory bowel disease (IBD) such as Crohn's disease (CD) or ulcerative colitis (UC). However, the mechanisms leading to complement expression in IECs seem to differ markedly between UC and CD patients. Hence, how IECs, intestinal bacteria and epithelial cell expressed complement components interact in the course of IBD still remains to be mostly elucidated to define potential unique patterns contributing to the distinct subtypes of intestinal inflammation observed in CD and UC. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Treatment of children with intestinal failure: intestinal rehabilitation, home parenteral nutrition or small intestine transplantation?

NARCIS (Netherlands)

Neelis, E.G.; Oers, H.A. van; Escher, J.C.; Damen, G.M.; Rings, E.H.; Tabbers, M.M.

2014-01-01

Intestinal failure is characterised by inadequate absorption of food or fluids, which is caused by insufficient bowel surface area or functioning. Children with chronic intestinal failure are dependent on parenteral nutrition (PN), which can be provided at home (HPN). In the Netherlands, HPN for

Diabetes mellitus tipo 2: qual o papel da insulina na expressão de NF-kappaB, PPARγ e CD36?

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Cristina de Oliveira SILVA

2014-12-01

Full Text Available No diabetes mellitus tipo 2 (DM2 e na síndrome de resistência à insulina, as complicações cardiovasculares resultam de um conjunto de processos aterogênicos envolvendo hiperglicemia crônica, excessiva glicação de proteínas (AGEs, ativação do fator nuclear kappa B (NKκB associada com o aumento da expressão de citocinas inflamatórias e estresse oxidativo, observando-se ainda alteração de LDL e expressão do receptor de scavenger CD36. A contribuição da hiperinsulinemia nesta sequência não é completamente elucidada. Nesta revisão, relata-se como a insulina pode modular a expressão proteica de NFκB, PPAR gama (PPARγ e CD36 em células da musculatura lisa vascular (CMLV da aorta de ratos estimuladas pelos AGE.

The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Eiichi [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Hosokawa, Masaya [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Faculty of Human Sciences, Tezukayama Gakuin University, Osaka (Japan); Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Tsukiyama, Katsushi; Yamada, Yuichiro [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Department of Internal Medicine, Division of Endocrinology, Diabetes and Geriatric Medicine, Akita University School of Medicine, Akita (Japan); Seino, Yutaka [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Kansai Electric Power Hospital, Osaka (Japan); Inagaki, Nobuya, E-mail: inagaki@metab.kuhp.kyoto-u.ac.jp [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); CREST of Japan Science and Technology Cooperation (JST), Kyoto (Japan)

2011-01-07

Research highlights: {yields} Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. {yields} Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. {yields} The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic {beta} cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [{sup 14}C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [{sup 14}C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin

The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

International Nuclear Information System (INIS)

Ogawa, Eiichi; Hosokawa, Masaya; Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito; Tsukiyama, Katsushi; Yamada, Yuichiro; Seino, Yutaka; Inagaki, Nobuya

2011-01-01

Research highlights: → Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. → Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. → The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic β cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [ 14 C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [ 14 C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin-mediated pathway rather

Intestinal subepithelial myofibroblasts support in vitro and in vivo growth of human small intestinal epithelium.

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Nicholas Lahar

Full Text Available The intestinal crypt-niche interaction is thought to be essential to the function, maintenance, and proliferation of progenitor stem cells found at the bases of intestinal crypts. These stem cells are constantly renewing the intestinal epithelium by sending differentiated cells from the base of the crypts of Lieberkühn to the villus tips where they slough off into the intestinal lumen. The intestinal niche consists of various cell types, extracellular matrix, and growth factors and surrounds the intestinal progenitor cells. There have recently been advances in the understanding of the interactions that regulate the behavior of the intestinal epithelium and there is great interest in methods for isolating and expanding viable intestinal epithelium. However, there is no method to maintain primary human small intestinal epithelium in culture over a prolonged period of time. Similarly no method has been published that describes isolation and support of human intestinal epithelium in an in vivo model. We describe a technique to isolate and maintain human small intestinal epithelium in vitro from surgical specimens. We also describe a novel method to maintain human intestinal epithelium subcutaneously in a mouse model for a prolonged period of time. Our methods require various growth factors and the intimate interaction between intestinal sub-epithelial myofibroblasts (ISEMFs and the intestinal epithelial cells to support the epithelial in vitro and in vivo growth. Absence of these myofibroblasts precluded successful maintenance of epithelial cell formation and proliferation beyond just a few days, even in the presence of supportive growth factors. We believe that the methods described here can be used to explore the molecular basis of human intestinal stem cell support, maintenance, and growth.

Fecal markers of intestinal inflammation and intestinal permeability are elevated in Parkinson's disease.

Science.gov (United States)

Schwiertz, Andreas; Spiegel, Jörg; Dillmann, Ulrich; Grundmann, David; Bürmann, Jan; Faßbender, Klaus; Schäfer, Karl-Herbert; Unger, Marcus M

2018-02-12

Intestinal inflammation and increased intestinal permeability (both possibly fueled by dysbiosis) have been suggested to be implicated in the multifactorial pathogenesis of Parkinson's disease (PD). The objective of the current study was to investigate whether fecal markers of inflammation and impaired intestinal barrier function corroborate this pathogenic aspect of PD. In a case-control study, we quantitatively analyzed established fecal markers of intestinal inflammation (calprotectin and lactoferrin) and fecal markers of intestinal permeability (alpha-1-antitrypsin and zonulin) in PD patients (n = 34) and controls (n = 28, group-matched for age) by enzyme-linked immunosorbent assay. The study design controlled for potential confounding factors. Calprotectin, a fecal marker of intestinal inflammation, and two fecal markers of increased intestinal permeability (alpha-1-antitrypsin and zonulin) were significantly elevated in PD patients compared to age-matched controls. Lactoferrin, as a second fecal marker of intestinal inflammation, showed a non-significant trend towards elevated concentrations in PD patients. None of the four fecal markers correlated with disease severity, PD subtype, dopaminergic therapy, or presence of constipation. Fecal markers reflecting intestinal inflammation and increased intestinal permeability have been primarily investigated in inflammatory bowel disease so far. Our data indicate that calprotectin, alpha-1-antitrypsin and zonulin could be useful non-invasive markers in PD as well. Even though these markers are not disease-specific, they corroborate the hypothesis of an intestinal inflammation as contributing factor in the pathogenesis of PD. Further investigations are needed to determine whether calprotectin, alpha-1-antitrypsin and zonulin can be used to define PD subgroups and to monitor the effect of interventions in PD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Intestinal cytochromes P450 regulating the intestinal microbiota and its probiotic profile

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Eugenia Elefterios Venizelos Bezirtzoglou

2012-09-01

Full Text Available Cytochromes P450 (CYPs enzymes metabolize a large variety of xenobiotic substances. In this vein, a plethora of studies were conducted to investigate their role, as cytochromes are located in both liver and intestinal tissues. The P450 profile of the human intestine has not been fully characterized. Human intestine serves primarily as an absorptive organ for nutrients, although it has also the ability to metabolize drugs. CYPs are responsible for the majority of phase I drug metabolism reactions. CYP3A represents the major intestinal CYP (80% followed by CYP2C9. CYP1A is expressed at high level in the duodenum, together with less abundant levels of CYP2C8-10 and CYP2D6. Cytochromes present a genetic polymorphism intra- or interindividual and intra- or interethnic. Changes in the pharmacokinetic profile of the drug are associated with increased toxicity due to reduced metabolism, altered efficacy of the drug, increased production of toxic metabolites, and adverse drug interaction. The high metabolic capacity of the intestinal flora is due to its enormous pool of enzymes, which catalyzes reactions in phase I and phase II drug metabolism. Compromised intestinal barrier conditions, when rupture of the intestinal integrity occurs, could increase passive paracellular absorption. It is clear that high microbial intestinal charge following intestinal disturbances, ageing, environment, or food-associated ailments leads to the microbial metabolism of a drug before absorption. The effect of certain bacteria having a benefic action on the intestinal ecosystem has been largely discussed during the past few years by many authors. The aim of the probiotic approach is to repair the deficiencies in the gut flora and establish a protective effect. There is a tentative multifactorial association of the CYP (P450 cytochrome role in the different diseases states, environmental toxic effects or chemical exposures and nutritional status.

Testing and Characterization of a Prototype Telescope for the Evolved Laser Interferometer Space Antenna (eLISA)

Science.gov (United States)

Sankar, S.; Livas, J.

2016-01-01

We describe our efforts to fabricate, test and characterize a prototype telescope for the eLISA mission. Much of our work has centered on the modeling and measurement of scattered light performance. This work also builds on a previous demonstration of a high dimensional stability metering structure using particular choices of materials and interfaces. We will discuss ongoing plans to merge these two separate demonstrations into a single telescope design demonstrating both stray light and dimensional stability requirements simultaneously.

[Myosin B ATPase activity of the intestinal smooth muscle in intestinal obstruction].

Science.gov (United States)

Takamatsu, H

1983-06-01

Intestinal smooth myosin B was prepared from muscle layers around the lesion in dogs with experimental colonic stenosis and in patients with congenital intestinal obstruction. Mg2+-ATPase activity of the myosin B was compared between the proximal dilated segment and distal segment to obstruction. Experimental colonic stenosis: In early period after surgery, proximal colons showed higher activity of myosin B ATPase than distal colons, decreasing to less than distal colon as time passed. Congenital intestinal obstruction: In three cases, whose atresia might have occurred at earlier period of gestation, proximal bowels showed less activity of myosin B ATPase than distal bowels. However, in two cases, whose atresia might have occurred at later period of gestation, and two cases with intestinal stenosis, proximal bowels indicated higher activity of myosin B ATPase than distal bowels. These data suggested that the contractibility of the proximal intestine was depending on the duration of obstruction, and it was depressed in the former patients and was accelerated in the latter patients. These results suggested that the extensive resection of dilated proximal bowel in the congenital atresia is not always necessary to obtain good postoperative intestinal dynamics at the operation of the atresial lesions which may be induced at later period of gestation. They also suggested that surgery for intestinal obstruction should be performed before the depression of intestinal contractibility to get good bowel function.

[Congenital intestinal lymphangiectasia].

Science.gov (United States)

Popović, Dugan D j; Spuran, Milan; Alempijević, Tamara; Krstić, Miodrag; Djuranović, Srdjan; Kovacević, Nada; Damnjanović, Svetozar; Micev, Marjan

2011-03-01

Congenital intestinal lymphangiectasia is a disease which leads to protein losing enteropathy. Tortuous, dilated lymphatic vessels in the intestinal wall and mesenterium are typical features of the disease. Clinical manifestations include malabsorption, diarrhea, steatorrhea, edema and effusions. Specific diet and medication are required for disease control. A 19-year old male patient was hospitalized due to diarrhea, abdominal swelling, weariness and fatigue. Physical examination revealed growth impairment, ascites, and lymphedema of the right hand and forearm. Laboratory assessment indicated iron deficiency anaemia, lymphopenia, malabsorption, inflammatory syndrome, and urinary infection. Enteroscopy and video capsule endoscopy demonstrated dilated lymphatic vessels in the small intestine. The diagnosis was confirmed by intestinal biopsy. The patient was put on high-protein diet containing medium-chain fatty acids, somatotropin and supportive therapy. Congenital intestinal lymphangiectasia is a rare disease, usually diagnosed in childhood. Early recognition of the disease and adequate treatment can prevent development of various complications.

Parasites and hepatic histopathological lesions in lisa (Mugil incilis from Totumo mash, North of Colombia

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Jesús Olivero V.

2013-03-01

Full Text Available Objective. To assess the levels of parasitism by nematodes and trematodes, as well as the hepatic histopathological alterations present in Mugil incilis (Lisa from Totumo marsh, North of Colombia. Materials and methods. Between July 2004 and June 2005, 500 fish were collected at Totumo Marsh (75°16’W and 10°44´N, North of Colombia. Morphometric and parasitic parameters were determined for each specimen, and the hepatic histopathological status of the liver was assessed by analyzing liver slides stained with hematoxylin and eosin. Results. Nematode larvae isolated from Mugil incilis corresponded to Contracaecum spp. Parasite prevalence was 60.49%. Parasitic mean abundance and mean intensity were 4.8±1.05 and 7.02±1.49, nematodes per fish, respectively. The correlation between nematode mean abundance and fish length was significant and positive (r=0.525, p<0.0001, but negative for condition factor (r=-0.109, p=0.014. Hepatic histopathological analysis revealed the presence of encapsulated trematode larvae as the main finding. However, the presence of inflammation, granulomas, steatosis and necrosis, were also registered as secondary alterations. Conclusions. Lisas collected at Totumo Marsh are parasitized with nematodes and trematodes. These fish have different histopathological lesions in the liver tissue, being the most important the presence of trematode encapsulated cyst that generate inflammatory reactions, and negatively correlate with morphometric markers of fish health.

Autophagy and tight junction proteins in the intestine and intestinal diseases

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Chien-An A. Hu

2015-09-01

Full Text Available The intestinal epithelium (IE forms an indispensible barrier and interface between the intestinal interstitium and the luminal environment. The IE regulates water, ion and nutrient transport while providing a barrier against toxins, pathogens (bacteria, fungi and virus and antigens. The apical intercellular tight junctions (TJ are responsible for the paracellular barrier function and regulate trans-epithelial flux of ions and solutes between adjacent cells. Increased intestinal permeability caused by defects in the IE TJ barrier is considered an important pathogenic factor for the development of intestinal inflammation, diarrhea and malnutrition in humans and animals. In fact, defects in the IE TJ barrier allow increased antigenic penetration, resulting in an amplified inflammatory response in inflammatory bowel disease (IBD, necrotizing enterocolitis and ischemia-reperfusion injury. Conversely, the beneficial enhancement of the intestinal TJ barrier has been shown to resolve intestinal inflammation and apoptosis in both animal models of IBD and human IBD. Autophagy (self-eating mechanism is an intracellular lysosome-dependent degradation and recycling pathway essential for cell survival and homeostasis. Dysregulated autophagy has been shown to be directly associated with many pathological processes, including IBD. Importantly, the crosstalk between IE TJ and autophagy has been revealed recently. We showed that autophagy enhanced IE TJ barrier function by increasing transepithelial resistance and reducing the paracellular permeability of small solutes and ions, which is, in part, by targeting claudin-2, a cation-selective, pore-forming, transmembrane TJ protein, for lysosome (autophagy-mediated degradation. Interestingly, previous studies have shown that the inflamed intestinal mucosa in patients with active IBD has increased claudin-2 expression. In addition, inflammatory cytokines (for example, tumor necrosis factor-α, interleukin-6

Detecting white dwarf binaries in Mock LISA Data Challenge 3

International Nuclear Information System (INIS)

Blaut, A; Krolak, A; Babak, S

2009-01-01

We present a strategy for detecting gravitational wave signals from the Galactic white dwarf binaries in the Mock LISA Data Challenge 3 (MLDC3) and estimate their parameters. Our method is based on the matched filtering in the form of the F-statistic. We perform the search on three-dimensional space (sky coordinate and frequency of gravitational wave) below 3 mHz and include the fourth parameter (frequency derivative) at high frequencies. A template bank is used to search for the strongest signal in the data, then we remove it and repeat the search until we do not have signals in the data above a preselected threshold. For the template bank, we construct an optimal grid that realizes the best lattice covering with a constraint such that the nodes of the grid coincide with the Fourier frequencies. This enables the use of the fast Fourier transform algorithm to calculate the F-statistic.

Congenital intestinal lymphangiectasia

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Popović Dušan Đ.

2011-01-01

Full Text Available Background. Congenital intestinal lymphangiectasia is a disease which leads to protein losing enteropathy. Tortous, dilated lymphatic vessels in the intestinal wall and mesenterium are typical features of the disease. Clinical manifestations include malabsorption, diarrhea, steatorrhea, edema and effusions. Specific diet and medication are required for disease control. Case report. A 19-year old male patient was hospitalized due to diarrhea, abdominal swelling, weariness and fatigue. Physical examination revealed growth impairment, ascites, and lymphedema of the right hand and forearm. Laboratory assessment indicated iron deficiency anaemia, lymphopenia, malabsorption, inflammatory syndrome, and urinary infection. Enteroscopy and video capsule endoscopy demonstrated dilated lymphatic vessels in the small intestine. The diagnosis was confirmed by intestinal biopsy. The patient was put on high-protein diet containing medium-chain fatty acids, somatotropin and suportive therapy. Conclusion. Congenital intestinal lymphangiectasia is a rare disease, usually diagnosed in childhood. Early recognition of the disease and adequate treatment can prevent development of various complications.

Intestine transplantation

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Tadeja Pintar

2011-02-01

Conclusion: Intestine transplantation is reserved for patients with irreversible intestinal failure due to short gut syndrome requiring total paranteral nutrition with no possibility of discontinuation and loss of venous access for patient maintenance. In these patients complications of underlying disease and long-term total parenteral nutrition are present.

Intestinal Microbiota Influences Non-intestinal Related Autoimmune Diseases

Science.gov (United States)

Opazo, Maria C.; Ortega-Rocha, Elizabeth M.; Coronado-Arrázola, Irenice; Bonifaz, Laura C.; Boudin, Helene; Neunlist, Michel; Bueno, Susan M.; Kalergis, Alexis M.; Riedel, Claudia A.

2018-01-01

The human body is colonized by millions of microorganisms named microbiota that interact with our tissues in a cooperative and non-pathogenic manner. These microorganisms are present in the skin, gut, nasal, oral cavities, and genital tract. In fact, it has been described that the microbiota contributes to balancing the immune system to maintain host homeostasis. The gut is a vital organ where microbiota can influence and determine the function of cells of the immune system and contributes to preserve the wellbeing of the individual. Several articles have emphasized the connection between intestinal autoimmune diseases, such as Crohn's disease with dysbiosis or an imbalance in the microbiota composition in the gut. However, little is known about the role of the microbiota in autoimmune pathologies affecting other tissues than the intestine. This article focuses on what is known about the role that gut microbiota can play in the pathogenesis of non-intestinal autoimmune diseases, such as Grave's diseases, multiple sclerosis, type-1 diabetes, systemic lupus erythematosus, psoriasis, schizophrenia, and autism spectrum disorders. Furthermore, we discuss as to how metabolites derived from bacteria could be used as potential therapies for non-intestinal autoimmune diseases. PMID:29593681

Intestinal Microbiota Influences Non-intestinal Related Autoimmune Diseases

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Maria C. Opazo

2018-03-01

Full Text Available The human body is colonized by millions of microorganisms named microbiota that interact with our tissues in a cooperative and non-pathogenic manner. These microorganisms are present in the skin, gut, nasal, oral cavities, and genital tract. In fact, it has been described that the microbiota contributes to balancing the immune system to maintain host homeostasis. The gut is a vital organ where microbiota can influence and determine the function of cells of the immune system and contributes to preserve the wellbeing of the individual. Several articles have emphasized the connection between intestinal autoimmune diseases, such as Crohn's disease with dysbiosis or an imbalance in the microbiota composition in the gut. However, little is known about the role of the microbiota in autoimmune pathologies affecting other tissues than the intestine. This article focuses on what is known about the role that gut microbiota can play in the pathogenesis of non-intestinal autoimmune diseases, such as Grave's diseases, multiple sclerosis, type-1 diabetes, systemic lupus erythematosus, psoriasis, schizophrenia, and autism spectrum disorders. Furthermore, we discuss as to how metabolites derived from bacteria could be used as potential therapies for non-intestinal autoimmune diseases.

Intestinal Permeability: The Basics

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Ingvar Bjarnason

1995-01-01

Full Text Available The authors review some of the more fundamental principles underlying the noninvasive assessment of intestinal permeability in humans, the choice of test markers and their analyses, and the practical aspects of test dose composition and how these can be changed to allow the specific assessment of regional permeability changes and other intestinal functions. The implications of increased intestinal permeability in the pathogenesis of human disease is discussed in relation to findings in patients with Crohn’s disease. A common feature of increased intestinal permeability is the development of a low grade enteropathy, and while quantitatively similar changes may be found in Crohn’s disease these seem to predict relapse of disease. Moreover, factors associated with relapse of Crohn’s disease have in common an action to increase intestinal permeability. While increased intestinal permeability does not seem to be important in the etiology of Crohn’s disease it may be a central mechanism in the clinical relapse of disease.

Intestinal Microbiota Signatures Associated With Histological Liver Steatosis in Pediatric-Onset Intestinal Failure

NARCIS (Netherlands)

Korpela, K.; Mutanen, A.; Salonen, A.; Savilahti, E.; Vos, de W.M.; Pakarinen, M.P.

2017-01-01

BACKGROUND: Intestinal failure (IF)-associated liver disease (IFALD) is the major cause of mortality in IF. The link between intestinal microbiota and IFALD is unclear. METHODS: We compared intestinal microbiota of patients with IF (n = 23) with healthy controls (n = 58) using culture-independent

Intestinal ischemia-reperfusion injury augments intestinal mucosal injury and bacterial translocation in jaundiced rats.

Science.gov (United States)

Yüksek, Yunus Nadi; Kologlu, Murat; Daglar, Gül; Doganay, Mutlu; Dolapci, Istar; Bilgihan, Ayse; Dolapçi, Mete; Kama, Nuri Aydin

2004-01-01

The aim of this study was to evaluate local effects and degree of bacterial translocation related with intestinal ischemia-reperfusion injury in a rat obstructive jaundice model. Thirty adult Sprague-Dawley rats (200-250 g) were divided into three groups; including Group 1 (jaundice group), Group 2 (jaundice-ischemia group) and Group 3 (ischemia group). All rats had 2 laparotomies. After experimental interventions, tissue samples for translocation; liver and ileum samples for histopathological examination, 25 cm of small intestine for mucosal myeloperoxidase and malondialdehyde levels and blood samples for biochemical analysis were obtained. Jaundiced rats had increased liver enzyme levels and total and direct bilirubin levels (p<0.05). Intestinal mucosal myeloperoxidase and malondialdehyde levels were found to be high in intestinal ischemia-reperfusion groups (p<0.05). Intestinal mucosal damage was more severe in rats with intestinal ischemia-reperfusion after bile duct ligation (p<0.05). Degree of bacterial translocation was also found to be significantly high in these rats (p<0.05). Intestinal mucosa is disturbed more severely in obstructive jaundice with the development of ischemia and reperfusion. Development of intestinal ischemia-reperfusion in obstructive jaundice increases bacterial translocation.

Intestinal lymphangiectasia in children

Science.gov (United States)

Isa, Hasan M.; Al-Arayedh, Ghadeer G.; Mohamed, Afaf M.

2016-01-01

Intestinal lymphangiectasia (IL) is a rare disease characterized by dilatation of intestinal lymphatics. It can be classified as primary or secondary according to the underlying etiology. The clinical presentations of IL are pitting edema, chylous ascites, pleural effusion, acute appendicitis, diarrhea, lymphocytopenia, malabsorption, and intestinal obstruction. The diagnosis is made by intestinal endoscopy and biopsies. Dietary modification is the mainstay in the management of IL with a variable response. Here we report 2 patients with IL in Bahrain who showed positive response to dietary modification. PMID:26837404

Actuation stability test of the LISA pathfinder inertial sensor front-end electronics

Science.gov (United States)

Mance, Davor; Gan, Li; Weber, Bill; Weber, Franz; Zweifel, Peter

In order to limit the residual stray forces on the inertial sensor test mass in LISA pathfinder, √ it is required that the fluctuation of the test mass actuation voltage is within 2ppm/ Hz. The actuation voltage stability test on the flight hardware of the inertial sensor front-end electronics (IS FEE) is presented in this paper. This test is completed during the inertial sensor integration at EADS Astrium Friedrichshafen, Germany. The standard measurement method using voltmeter is not sufficient for verification, since the instrument low frequency √ fluctuation is higher than the 2ppm/ Hz requirement. In this test, by using the differential measurement method and the lock-in amplifier, the actuation stability performance is verified and the quality of the IS FEE hardware is confirmed by the test results.

Intestinal pseudo-obstruction

Science.gov (United States)

... Staying in bed for long periods of time (bedridden). Taking drugs that slow intestinal movements. These include ... be tried: Colonoscopy may be used to remove air from the large intestine. Fluids can be given ...

LISA. A code for safety assessment in nuclear waste disposals program description and user guide

International Nuclear Information System (INIS)

Saltelli, A.; Bertozzi, G.; Stanners, D.A.

1984-01-01

The code LISA (Long term Isolation Safety Assessment), developed at the Joint Research Centre, Ispra is a useful tool in the analysis of the hazard due to the disposal of nuclear waste in geological formations. The risk linked to preestablished release scenarios is assessed by the code in terms of dose rate to a maximum exposed individual. The various submodels in the code simulate the system of barriers -both natural and man made- which are interposed between the contaminants and man. After a description of the code features a guide for the user is supplied and then a test case is presented

Intestinal Leiomyositis: A Cause of Chronic Intestinal Pseudo?Obstruction in 6 Dogs

OpenAIRE

Zacuto, A.C.; Pesavento, P.A.; Hill, S.; McAlister, A.; Rosenthal, K.; Cherbinsky, O.; Marks, S.L.

2015-01-01

Background Intestinal leiomyositis is a suspected autoimmune disorder affecting the muscularis propria layer of the gastrointestinal tract and is a cause of chronic intestinal pseudo?obstruction in humans and animals. Objective To characterize the clinical presentation, histopathologic features, and outcome of dogs with intestinal leiomyositis in an effort to optimize treatment and prognosis. Animals Six client?owned dogs. Methods Retrospective case series. Medical records were reviewed to de...

Diffused and sustained inhibitory effects of intestinal electrical stimulation on intestinal motility mediated via sympathetic pathway.

Science.gov (United States)

Zhao, Xiaotuan; Yin, Jieyun; Wang, Lijie; Chen, Jiande D Z

2014-06-01

The aims were to investigate the energy-dose response effect of intestinal electrical stimulation (IES) on small bowel motility, to compare the effect of forward and backward IES, and to explore the possibility of using intermittent IES and mechanism of IES on intestinal motility. Five dogs implanted with a duodenal cannula and one pair of intestinal serosal electrodes were studied in five sessions: 1) energy-dose response study; 2) forward IES; 3) backward IES; 4) intermittent IES vs. continuous IES; 5) administration of guanethidine. The contractile activity and tonic pressure of the small intestine were recorded. The duration of sustained effect after turning off IES was manually calculated. 1) IES with long pulse energy dose dependently inhibited contractile activity and tonic pressure of the small intestine (p intestine depended on the energy of IES delivered (p intestine. 5) Guanethidine blocked the inhibitory effect of IES on intestinal motility. IES with long pulses inhibits small intestinal motility; the effect is energy-dose dependent, diffused, and sustained. Intermittent IES has the same efficacy as the continuous IES in inhibiting small intestinal motility. Forward and backward IES have similar inhibitory effects on small bowel motility. This IES-induced inhibitory effect is mediated via the sympathetic pathway. © 2013 International Neuromodulation Society.

Analog phase lock between two lasers at LISA power levels

International Nuclear Information System (INIS)

Diekmann, Christian; Steier, Frank; Sheard, Benjamin; Heinzel, Gerhard; Danzmann, Karsten

2009-01-01

This paper presents the implementation of an analog optical phase-locked-loop with an offset frequency of about 20MHz between two lasers, where the detected light powers were of the order of 31 pW and 200 μW. The goal of this setup was the design and characterization of a photodiode transimpedance amplifier for application in LISA. By application of a transimpedance amplifier designed to have low noise and low power consumption, the phase noise between the two lasers was a factor of two above the shot noise limit down to 60mHz. The achievable phase sensitivity depends ultimately on the available power of the highly attenuated master laser and on the input current noise of the transimpedance amplifier of the photodetector. The limiting noise source below 60mHz was the analog phase measurement system that was used in this experiment. A digital phase measurement system that is currently under development at the AEI will be used in the near future. Its application should improve the sensitivity.

Analog phase lock between two lasers at LISA power levels

Energy Technology Data Exchange (ETDEWEB)

Diekmann, Christian; Steier, Frank; Sheard, Benjamin; Heinzel, Gerhard; Danzmann, Karsten, E-mail: Christian.Diekmann@aei.mpg.d [Max-Planck-Institute for Gravitational Physics, Callinstr. 38, D-30167 Hannover (Germany)

2009-03-01

This paper presents the implementation of an analog optical phase-locked-loop with an offset frequency of about 20MHz between two lasers, where the detected light powers were of the order of 31 pW and 200 muW. The goal of this setup was the design and characterization of a photodiode transimpedance amplifier for application in LISA. By application of a transimpedance amplifier designed to have low noise and low power consumption, the phase noise between the two lasers was a factor of two above the shot noise limit down to 60mHz. The achievable phase sensitivity depends ultimately on the available power of the highly attenuated master laser and on the input current noise of the transimpedance amplifier of the photodetector. The limiting noise source below 60mHz was the analog phase measurement system that was used in this experiment. A digital phase measurement system that is currently under development at the AEI will be used in the near future. Its application should improve the sensitivity.

Planning for chemical disasters at Point Lisas, Trinidad and Tobago

International Nuclear Information System (INIS)

Mathur, M.N.

1995-01-01

No major chemical disaster has taken place so far in Trinidad and Tobago. Even so, in view of the numerous hazards that the various chemical handling plants deal with at Point Lisas, the country has to be prepared to deal with chemical disasters. The country's emergency preparedness plan for chemical disasters aims to localize the emergency, if possible, eliminate it and minimize the effects of the accident on people and property. The hazards of ammonia, hydrogen, chlorine, hydrocarbons and methanol release can have devastating effects on the workers and the residents in the vicinity of the plants. The Emergency Plan identifies an Emergency Co-ordinating Officer who would take command of the off-site activities and coordinate the activities of Works Management, Local Authority, Police, Fire Services, Defence Force, Health Authority and Factory Inspectorate. Resources of fire fighting, medical treatment, telecommunications, waste management and public education have to be enhanced immediately. In the long term a new fire station and a new county hospital have to be built, some housing settlements have to be phased out and non-essential staff relocated

Complicating Culture and Difference: Situating Asian American Youth Identities in Lisa Yee's "Millicent Min," "Girl Genius" and "Stanford Wong Flunks Big-Time"

Science.gov (United States)

Endo, Rachel

2009-01-01

This review situates how culture, difference, and identity are discursively constructed in "Millicent Min, Girl Genius" and "Stanford Wong Flunks Big-Time," two award-winning books written by critically acclaimed Asian American author Lisa Yee. Using contextual literacy approaches, the characters, cultural motifs, and physical settings in these…

Intestinal lymphangiectasia in adults.

Science.gov (United States)

Freeman, Hugh James; Nimmo, Michael

2011-02-15

Intestinal lymphangiectasia in the adult may be characterized as a disorder with dilated intestinal lacteals causing loss of lymph into the lumen of the small intestine and resultant hypoproteinemia, hypogammaglobulinemia, hypoalbuminemia and reduced number of circulating lymphocytes or lymphopenia. Most often, intestinal lymphangiectasia has been recorded in children, often in neonates, usually with other congenital abnormalities but initial definition in adults including the elderly has become increasingly more common. Shared clinical features with the pediatric population such as bilateral lower limb edema, sometimes with lymphedema, pleural effusion and chylous ascites may occur but these reflect the severe end of the clinical spectrum. In some, diarrhea occurs with steatorrhea along with increased fecal loss of protein, reflected in increased fecal alpha-1-antitrypsin levels, while others may present with iron deficiency anemia, sometimes associated with occult small intestinal bleeding. Most lymphangiectasia in adults detected in recent years, however, appears to have few or no clinical features of malabsorption. Diagnosis remains dependent on endoscopic changes confirmed by small bowel biopsy showing histological evidence of intestinal lymphangiectasia. In some, video capsule endoscopy and enteroscopy have revealed more extensive changes along the length of the small intestine. A critical diagnostic element in adults with lymphangiectasia is the exclusion of entities (e.g. malignancies including lymphoma) that might lead to obstruction of the lymphatic system and "secondary" changes in the small bowel biopsy. In addition, occult infectious (e.g. Whipple's disease from Tropheryma whipplei) or inflammatory disorders (e.g. Crohn's disease) may also present with profound changes in intestinal permeability and protein-losing enteropathy that also require exclusion. Conversely, rare B-cell type lymphomas have also been described even decades following initial

Expression of an Intestine-Specific Transcription Factor (CDX1) in Intestinal Metaplasia and in Subsequently Developed Intestinal Type of Cholangiocarcinoma in Rat Liver

Science.gov (United States)

Ren, Ping; Silberg, Debra G.; Sirica, Alphonse E.

2000-01-01

CDX1 is a caudal-type homeobox intestine-specific transcription factor that has been shown to be selectively expressed in epithelial cells in intestinal metaplasia of the human stomach and esophagus and variably expressed in human gastric and esophageal adenocarcinomas (Silberg DG, Furth EE, Taylor JK, Schuck T, Chiou T, Traber PG: Gastroenterology 1997, 113: 478–486). Through the use of immunohistochemistry and Western blotting, we investigated whether CDX1 is also uniquely associated with the intestinal metaplasia associated with putative precancerous cholangiofibrosis induced in rat liver during furan cholangiocarcinogenesis, as well as expressed in neoplastic glands in a subsequently developed intestinal type of cholangiocarcinoma. In normal, control adult rat small intestine, specific nuclear immunoreactivity for CDX1 was most prominent in enterocytes lining the crypts. In comparison, epithelium from intestinal metaplastic glands within furan-induced hepatic cholangiofibrosis and neoplastic epithelium from later developed primary intestinal-type cholangiocarcinoma each demonstrated strong nuclear immunoreactivity for CDX1. CDX1-positive cells were detected in hepatic cholangiofibrotic tissue as early as 3 weeks after the start of chronic furan treatment. We further determined that the percentages of CDX1-positive neoplastic glands and glandular nuclei are significantly higher in primary tumors than in a derived, transplantable cholangiocarcinoma serially-propagated in vivo. Western blotting confirmed our immunohistochemical results, and no CDX1 immunoreactivity was detected in normal adult rat liver or in hyperplastic biliary epithelial cells. These findings indicate that CDX1 is specifically associated with early intestinal metaplasia and a later developed intestinal-type of cholangiocarcinoma induced in the liver of furan-treated rats. PMID:10666391

The CT signs of intestinal volvulus

International Nuclear Information System (INIS)

Ji Jiansong; Wang Zufei; Xu Zhaolong; Lv Guijian; Xu Min; Zhao Zhongwei; Su Jinliang; Zhou Limin

2005-01-01

Objective: To improve the accuracy rate of spiral CT diagnosing intestinal volvulus. Methods: To analysis the CT findings of 9 cases of intestinal volvulus proved by operation, the main reconstruction techniques were multiplanar reformation (MPR) and sliding thin-slab maximum intensity projection (STS-MIP). Results: All the 9 cases were diagnosed accurately, the main signs were 'whirlpool' of intestine (6 cases) and vessels (9 cases),'target loop' (2 cases),'beak'(6 cases). Conclusion: 'Whirlpool' of vessels is a specific sign to diagnose intestinal volvulus, 'target loop', reduced enhancement of intestinal wall and ascites are the reliable signs to strangulated intestinal obstruction. Spiral CT and reconstructions have important value to diagnose the intestinal volvulus. (authors)

The Effect of DA-6034 on Intestinal Permeability in an Indomethacin-Induced Small Intestinal Injury Model.

Science.gov (United States)

Kwak, Dong Shin; Lee, Oh Young; Lee, Kang Nyeong; Jun, Dae Won; Lee, Hang Lak; Yoon, Byung Chul; Choi, Ho Soon

2016-05-23

DA-6034 has anti-inflammatory activities and exhibits cytoprotective effects in acute gastric injury models. However, explanations for the protective effects of DA-6034 on intestinal permeability are limited. This study sought to investigate the effect of DA-6034 on intestinal permeability in an indomethacin-induced small intestinal injury model and its protective effect against small intestinal injury. Rats in the treatment group received DA-6034 from days 0 to 2 and indomethacin from days 1 to 2. Rats in the control group received indomethacin from days 1 to 2. On the fourth day, the small intestines were examined to compare the severity of inflammation. Intestinal permeability was evaluated by using fluorescein isothiocyanate-labeled dextran. Western blotting was performed to confirm the association between DA-6034 and the extracellular signal-regulated kinase (ERK) pathway. The inflammation scores in the treatment group were lower than those in the control group, but the difference was statistically insignificant. Hemorrhagic lesions in the treatment group were broader than those in the control group, but the difference was statistically insignificant. Intestinal permeability was lower in the treatment group than in the control group. DA-6034 enhanced extracellular signal-regulated kinase expression, and intestinal permeability was negatively correlated with ERK expression. DA-6034 may decrease intestinal permeability in an indomethacin-induced intestinal injury model via the ERK pathway.

Foreign body-associated intestinal pyogranuloma resulting in intestinal obstruction in four dogs.

Science.gov (United States)

Papazoglou, L G; Tontis, D; Loukopoulos, P; Patsikas, M N; Hermanns, W; Kouti, V; Timotheou, T; Liapis, I; Tziris, N; Rallis, T S

2010-04-17

Intestinal obstruction resulting from an intramural foreign body-associated pyogranuloma was diagnosed in four dogs. Vomiting and weight loss were the main clinical signs. On physical examination, a mass in the abdomen was detected in three dogs. Abdominal radiography demonstrated the presence of soft tissue opacity in three of the dogs and gas-filled dilated intestinal loops in all four dogs. Abdominal ultrasonography showed hyperkinetic fluid-filled dilated intestinal loops and a hypoechoic small intestinal mass in all the dogs. Exploratory coeliotomy confirmed the presence of a jejunal mass, which was removed by resection and anastomosis in all the dogs. In one of the dogs a linear foreign body was also found cranial to the mass and was removed through a separate enterotomy incision. The lesions were diagnosed as foreign body-associated intestinal pyogranulomas on histological examination. Three dogs recovered without complications, but the fourth showed signs of septic peritonitis four days after surgery and was euthanased at the owner's request. The other three dogs remained disease-free 12 to 42 months after surgery.

Intestinal Microbiota Signatures Associated With Histological Liver Steatosis in Pediatric-Onset Intestinal Failure.

Science.gov (United States)

Korpela, Katri; Mutanen, Annika; Salonen, Anne; Savilahti, Erkki; de Vos, Willem M; Pakarinen, Mikko P

2017-02-01

Intestinal failure (IF)-associated liver disease (IFALD) is the major cause of mortality in IF. The link between intestinal microbiota and IFALD is unclear. We compared intestinal microbiota of patients with IF (n = 23) with healthy controls (n = 58) using culture-independent phylogenetic microarray analysis. The microbiota was related to histological liver injury, fecal markers of intestinal inflammation, matrix metalloproteinase 9 and calprotectin, and disease characteristics. Overabundance of Lactobacilli, Proteobacteria, and Actinobacteria was observed in IF, whereas bacteria related to Clostridium clusters III, IV, and XIVa along with overall diversity and richness were reduced. Patients were segregated into 3 subgroups based on dominating bacteria: Clostridium cluster XIVa, Proteobacteria, and bacteria related to Lactobacillus plantarum. In addition to liver steatosis and fibrosis, Proteobacteria were associated with prolonged current parenteral nutrition (PN) as well as liver and intestinal inflammation. Lactobacilli were related to advanced steatosis and fibrosis mostly after weaning off PN without associated inflammation. In multivariate permutational analysis of variance, liver steatosis, bowel length, PN calories, and antibiotic treatment best explained the microbiota variation among patients with IF. Intestinal microbiota composition was associated with liver steatosis in IF and better predicted steatosis than duration of PN or length of the remaining intestine. Our results may be explained by a model in which steatosis is initiated during PN in response to proinflammatory lipopolysaccharides produced by Proteobacteria and progresses after weaning off PN, as the L plantarum group Lactobacilli becomes dominant and affects lipid metabolism by altering bile acid signaling.

Primary intestinal lymphangiectasia.

Science.gov (United States)

Suresh, N; Ganesh, R; Sankar, Janani; Sathiyasekaran, Malathi

2009-10-01

Primary intestinal lymphangiectasia (PIL) is a rare disease of intestinal lymphatics presenting with hypoproteinemia, bilateral lower limb edema, ascites, and protein losing enteropathy. We report a series of 4 children from Chennai, India presenting with anasarca, recurrent diarrhea, hypoproteinemia and confirmatory features of PIL on endoscopy and histopathology.

Si-Jun-Zi Decoction Treatment Promotes the Restoration of Intestinal Function after Obstruction by Regulating Intestinal Homeostasis

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Xiangyang Yu

2014-01-01

Full Text Available Intestinal obstruction is a common disease requiring abdominal surgery with significant morbidity and mortality. Currently, an effective medical treatment for obstruction, other than surgical resection or decompression, does not exist. Si-Jun-Zi Decoction is a famous Chinese medicine used to replenish qi and invigorate the functions of the spleen. Modern pharmacological studies show that this prescription can improve gastrointestinal function and strengthen immune function. In this study, we investigated the effects of a famous Chinese herbal formula, Si-Jun-Zi Decoction, on the restoration of intestinal function after the relief of obstruction in a rabbit model. We found that Si-Jun-Zi Decoction could reduce intestinal mucosal injury while promoting the recovery of the small intestine. Further, Si-Jun-Zi Decoction could regulate the intestinal immune system. Our results suggest that Si-Jun-Zi Decoction promotes the restoration of intestinal function after obstruction by regulating intestinal homeostasis. Our observations indicate that Si-Jun-Zi Decoction is potentially a therapeutic drug for intestinal obstruction.

Bell's palsy: the answer to the riddle of Leonardo da Vinci's 'Mona Lisa'.

Science.gov (United States)

Maloney, W J

2011-05-01

The smile of the famed portrait 'The Mona Lisa' has perplexed both art historians and researchers for the past 500 years. There has been a multitude of theories expounded to explain the nature of the model's enigmatic smile. The origin of the model's wry smile can be demonstrated through a careful analysis of both documented facts concerning the portrait--some gathered only recently through the use of modern technology--and a knowledge of the clinical presentation of Bell's palsy. Bell's palsy is more prevalent in women who are either pregnant or who have recently given birth. This paper postulates that the smile of the portrait's model was due to Leonardo da Vinci's anatomically precise representation of a new mother affected by Bell's palsy subsequent to her recent pregnancy.

Efecto del tramadol en la motilidad del ciego en dos equinos sanos (estudio preliminar

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Anastasia Cruz-Carrillo

2012-07-01

Full Text Available El tramadol (analgésico opioide atípico es utilizado ampliamente en humanos y, en menor proporción, en animales, por falta de productos comerciales de uso veterinario. Es un analgésico eficaz que produce efectos adversos suaves, en comparación con los opioides típicos. Se propone su uso como alternativa en el manejo del dolor en equinos, a partir de la hipótesis de que al estimular los receptores opioides de manera suave, los efectos adversos en los equinos deben ser menores. Así, el objetivo del presente trabajo fue determinar el efecto del tramadol en la motilidad de la musculatura lisa de la base del ciego en equinos sanos. Se utilizaron tres equinos, a los cuales, mediante intervención quirúrgica, se les colocaron dos electrodos en la base del ciego, y se exteriorizaron sus extensiones por la pared abdominal, para conectarlas a un equipo de registro electromiográfico que permitió la valoración de la actividad intestinal 15 días después de colocados los electrodos y después de aplicar 1,2 mg de tramadol/kg de peso. Se comprobó que después de aplicar el tramadol hubo un descenso leve de la intensidad de las contracciones musculares, los sonidos intestinales estuvieron presentes, no hubo atonía, cólico ni estreñimiento. Adicionalmente, se comprobó su gran eficacia analgésica y la ausencia de cualquier efecto adverso. Se concluye que bajo las condiciones aquí planteadas, el tramadol no deprimió la motilidad del ciego en equinos sanos, aunque disminuyó la intensidad de las contracciones musculares en el ciego.

Gastric and intestinal surgery.

Science.gov (United States)

Fossum, Theresa W; Hedlund, Cheryl S

2003-09-01

Gastric surgery is commonly performed to remove foreign bodies and correct gastric dilatation-volvulus and is less commonly performed to treat gastric ulceration or erosion, neoplasia, and benign gastric outflow obstruction. Intestinal surgery, although commonly performed by veterinarians, should never be considered routine. The most common procedures of the small intestinal tract performed in dogs and cats include enterotomy and resection/anastomosis. Surgery of the large intestine is indicated for lesions causing obstruction, perforations, colonic inertia, or chronic inflammation.

Intestinal epithelium in inflammatory bowel disease

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Mehmet eCoskun

2014-08-01

Full Text Available The intestinal epithelium has a strategic position as a protective physical barrier to luminal microbiota and actively contributes to the mucosal immune system. This barrier is mainly formed by a monolayer of specialized intestinal epithelial cells (IECs that are crucial in maintaining intestinal homeostasis. Therefore, dysregulation within the epithelial layer can increase intestinal permeability, lead to abnormalities in interactions between IECs and immune cells in underlying lamina propria, and disturb the intestinal immune homeostasis, all of which are linked to the clinical disease course of inflammatory bowel disease (IBD. Understanding the role of the intestinal epithelium in IBD pathogenesis might contribute to an improved knowledge of the inflammatory processes and the identification of potential therapeutic targets.

Diagnosis of intestinal and extra intestinal amoebiasis

International Nuclear Information System (INIS)

Lopez, Myriam Consuelo; Quiroz, Damian Arnoldo; Pinilla, Analida Elizabeth

2007-01-01

The objective is to carry out a review of the national and international literature as of the XXth century in order to update the advances for the diagnosis of complex odd Entamoeba histolytic / Entamoeba dispar and that of intestinal and extra intestinal amoebiasis that may be of use to the scientific community. As well as to unify the diagnostic criteria of this parasitosis known as a public health problem, and as a consequence of that, optimize the quality of population care. Data source: there was a systematic search for the scientific literature Publisher in Spanish and English since 1960 until today, this selection started on the first semester of 2006 until 2007, in the development of the line on intestinal and extra-intestinal amoebiasis of the Medical School of the National University of Colombia. A retrospective search process was carried out, systematically reviewing the most relevant articles as well as the products of this research line. In deciding how to make this article, there was a continuous search in different data bases such as Medline, SciELO and other bases in the library of the National University of Colombia, as well as other classical books related to the subject. For that purpose the terms amoebiasis, odd Entamoeba histolytic, Entamoeba, diagnosis, epidemiology, dysentery, amoebic liver abscess, were used. Studies selection: titles and abstracts were reviewed to select the original publications and the most representative ones related to this article's subject. Data extraction: the articles were classified according to the subject, the chronology and the authors according to the scientific contribution to solve the problem. Synthesis of the data: in the fi rst instance, a chronological critical analysis was carried out to order and synthesize the progress made in the diagnosis until confirmation of the experts' agreements in the field of amoebiasis was obtained throughout the world. Conclusion: this article summarizes what has taken place

Intestinal transplantation: The anesthesia perspective.

Science.gov (United States)

Dalal, Aparna

2016-04-01

Intestinal transplantation is a complex and challenging surgery. It is very effective for treating intestinal failure, especially for those patients who cannot tolerate parenteral nutrition nor have extensive abdominal disease. Chronic parental nutrition can induce intestinal failure associated liver disease (IFALD). According to United Network for Organ Sharing (UNOS) data, children with intestinal failure affected by liver disease secondary to parenteral nutrition have the highest mortality on a waiting list when compared with all candidates for solid organ transplantation. Intestinal transplant grafts can be isolated or combined with the liver/duodenum/pancreas. Organ Procurement and Transplantation Network (OPTN) has defined intestinal donor criteria. Living donor intestinal transplant (LDIT) has the advantages of optimal timing, short ischemia time and good human leukocyte antigen matching contributing to lower postoperative complications in the recipient. Thoracic epidurals provide excellent analgesia for the donors, as well as recipients. Recipient management can be challenging. Thrombosis and obstruction of venous access maybe common due to prolonged parenteral nutrition and/or hypercoaguability. Thromboelastography (TEG) is helpful for managing intraoperative product therapy or thrombosis. Large fluid shifts and electrolyte disturbances may occur due to massive blood loss, dehydration, third spacing etc. Intestinal grafts are susceptible to warm and cold ischemia and ischemia-reperfusion injury (IRI). Post-reperfusion syndrome is common. Cardiac or pulmonary clots can be monitored with transesophageal echocardiography (TEE) and treated with recombinant tissue plasminogen activator. Vasopressors maybe used to ensure stable hemodynamics. Post-intestinal transplant patients may need anesthesia for procedures such as biopsies for surveillance of rejection, bronchoscopy, endoscopy, postoperative hemorrhage, anastomotic leaks, thrombosis of grafts etc. Asepsis

Presentation of a nationwide multicenter registry of intestinal failure and intestinal transplantation

NARCIS (Netherlands)

Neelis, E. G.; Roskott, A. M.; Dijkstra, G.; Wanten, G. J.; Serlie, M. J.; Tabbers, M. M.; Damen, G.; Olthof, E. D.; Jonkers, C. F.; Kloeze, J. H.; Ploeg, R. J.; Imhann, F.; Nieuwenhuijs, V. B.; Rings, E. H. H. M.

Background & aims: Exact data on Dutch patients with chronic intestinal failure (CIF) and after intestinal transplantation (ITx) have been lacking. To improve standard care of these patients, a nationwide collaboration has been established. Objectives of this study were obtaining an up-to-date

Presentation of a nationwide multicenter registry of intestinal failure and intestinal transplantation

NARCIS (Netherlands)

Neelis, E.G.; Roskott, A.M.; Dijkstra, G.; Wanten, G.J.A.; Serlie, M.J.; Tabbers, M.M.; Damen, G.M.; Olthof, E.D.; Jonkers, C.F.; Kloeze, J.H.; Ploeg, R.J.; Imhann, F.; Nieuwenhuijs, V.B.; Rings, E.H.

2016-01-01

BACKGROUND & AIMS: Exact data on Dutch patients with chronic intestinal failure (CIF) and after intestinal transplantation (ITx) have been lacking. To improve standard care of these patients, a nationwide collaboration has been established. Objectives of this study were obtaining an up-to-date

Intestinal Stem Cell Markers in the Intestinal Metaplasia of Stomach and Barrett's Esophagus.

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Bo Gun Jang

Full Text Available Gastric intestinal metaplasia (IM is a highly prevalent preneoplastic lesion; however, the molecular mechanisms regulating its development remain unclear. We have previously shown that a population of cells expressing the intestinal stem cell (ISC marker LGR5 increases remarkably in IM. In this study, we further investigated the molecular characteristics of these LGR5+ cells in IM by examining the expression profile of several ISC markers. Notably, we found that ISC markers-including OLFM4 and EPHB2-are positively associated with the CDX2 expression in non-tumorous gastric tissues. This finding was confirmed in stomach lesions with or without metaplasia, which demonstrated that OLFM4 and EPHB2 expression gradually increased with metaplastic progression. Moreover, RNA in situ hybridization revealed that LGR5+ cells coexpress several ISC markers and remained confined to the base of metaplastic glands, reminiscent to that of normal intestinal crypts, whereas those in normal antral glands expressed none of these markers. Furthermore, a large number of ISC marker-expressing cells were diffusely distributed in gastric adenomas, suggesting that these markers may facilitate gastric tumorigenesis. In addition, Barrett's esophagus (BE-which is histologically similar to intestinal metaplasia-exhibited a similar distribution of ISC markers, indicating the presence of a stem cell population with intestinal differentiation potential. In conclusion, we identified that LGR5+ cells in gastric IM and BE coexpress ISC markers, and exhibit the same expression profile as those found in normal intestinal crypts. Taken together, these results implicate an intestinal-like stem cell population in the pathogenesis of IM, and provide an important basis for understanding the development and maintenance of this disease.

Non-Meckel Small Intestine Diverticulitis

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Shamim Ejaz

2017-08-01

Full Text Available Non-Meckel small intestine diverticulitis can have many manifestations and its management is not well-defined. We report 4 unselect cases of small intestine diverticulitis; all patients were seen by the same physician at the Emergency Center at The University of Texas MD Anderson Cancer Center between 1999 and 2014. The median age at diagnosis of these patients was 82 years (range, 76–87 years. All 4 patients presented with acute onset of abdominal pain, and computed tomography scans showed characteristics of small intestine diverticulitis unrelated to cancer. Most of the diverticula were found in the region of the duodenum and jejuno-ileal segments of the small intestine. The patients, even those with peripancreatic inflammation and localized perforation, were treated conservatively. Non-Meckel diverticulitis can be overlooked in the initial diagnosis because of the location of the diverticulosis, the age of the patient, and the rarity of the disease. Because patients with non-Meckel small intestine diverticulitis can present with acute abdominal pain, non-Meckel small intestine diverticulitis should be considered in the differential diagnosis of patients with acute abdominal pain, and computed tomography scans can help identify the condition. Because of the rarity of non-Meckel small intestine diverticulitis, few studies have been published, and the data are inconclusive about how best to approach these patients. Our experience with these 4 elderly patients indicates that non-Meckel small intestine diverticulitis can be treated conservatively, which avoids the potential morbidity and mortality of a surgical approach.

Dyslipidaemia--hepatic and intestinal cross-talk.

LENUS (Irish Health Repository)

Tomkin, Gerald H

2010-06-01

Cholesterol metabolism is tightly regulated with the majority of de novo cholesterol synthesis occurring in the liver and intestine. 3 Hydroxy-3-methylglutaryl coenzyme A reductase, a major enzyme involved in cholesterol synthesis, is raised in both liver and intestine in diabetic animals. Niemann PickC1-like1 protein regulates cholesterol absorption in the intestine and facilitates cholesterol transport through the liver. There is evidence to suggest that the effect of inhibition of Niemann PickC1-like1 lowers cholesterol through its effect not only in the intestine but also in the liver. ATP binding cassette proteins G5\\/G8 regulate cholesterol re-excretion in the intestine and in the liver, cholesterol excretion into the bile. Diabetes is associated with reduced ATP binding cassette protein G5\\/G8 expression in both the liver and intestine in animal models. Microsomal triglyceride transfer protein is central to the formation of the chylomicron in the intestine and VLDL in the liver. Microsomal triglyceride transfer protein mRNA is increased in diabetes in both the intestine and liver. Cross-talk between the intestine and liver is poorly documented in humans due to the difficulty in obtaining liver biopsies but animal studies are fairly consistent in showing relationships that explain in part mechanisms involved in cholesterol homeostasis.

Estudos anatômicos e histológicos sôbre a subfamília Triatominae (Heteroptera, Reduviidae: VII. Estudo anatômico do ducto intestinal do Triatoma infestans

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Dyrce Lacombe

1957-05-01

Full Text Available Devido à imprtãncia que certos Triatomíneos hematófagos representam na vida humana, continuarmos a série de estudos já iniciados em nosso laboratório sôbre seus organismos. É feito, no presente trabalho, a anatomia e microanatomai do aparelho digestivo de Triatoma infestans. Das três distintas regiões do duto intestinal estomodeo, mesêntero e proctodeo, a primeira e a terceira são de origem ectodérmica. A região do estomodeo é constituída pela faringe e esôfago; a do proctodeo pelo piloro, íleo e reto. A segunda, de origem endodérmica, consta promesêntero, postmesêntero e da zona de transição. A anatomia e a microanatomia do faringe já foi estudada minuciosamente por BARTH (1952. O esôfago possui numerosas dobras no seu interior revestida de fina cutícula. A musculatura longitudinal e circular acham-se representadas por feixes que, provàvelmente, trabalham, preistàlticamente, transportando o alimento. Não encontramos um proventrículo, de maneira que o esôfago está ligado diretamente à primeira parte endodérmica, isto é, ao promesêntero. No início do promesêntero existe a válvula cardíaca, que, juntamente com as dobras do fim do esôfago, impedem que haja um refluxo do alimento. Durante a alimentação, a parede do preomesêntero, que apresenta numerosas dobras, sofre uma dilatação, a fim de reter u'a maior quantidade de sangue. Entre promesêntero e postmesêntero há um pequeno esfíncter formado pelo aumento da musculatura e das dobras do epitélio. O postmesêntero alcança cinco vêzes mais que o tamanho total do corpo do inseto, e dispõe no abdome em curvas completas, que, muitas vêzes, se superpõem. O seu epitélio possue célula altas e estreitas, e forma muitas dobras para dentro do seu lume. Na parte apical as células possuem um rabdório. O postmesêntero termina após a válvula cardíaca situada atrás do desembocamento das quatro ampolas dos tubos de Malpighi. Entre postmesêntero e

Presentation of a nationwide multicenter registry of intestinal failure and intestinal transplantation

NARCIS (Netherlands)

Neelis, E. G.; Roskott, A. M.; Dijkstra, G.; Wanten, G. J.; Serlie, M. J.; Tabbers, M. M.; Damen, G.; Olthof, E. D.; Jonkers, C. F.; Kloeze, J. H.; Ploeg, R. J.; Imhann, F.; Nieuwenhuijs, V. B.; Rings, E. H. H. M.

2016-01-01

Exact data on Dutch patients with chronic intestinal failure (CIF) and after intestinal transplantation (ITx) have been lacking. To improve standard care of these patients, a nationwide collaboration has been established. Objectives of this study were obtaining an up-to-date prevalence of CIF and

Adult zebrafish intestine resection: a novel model of short bowel syndrome, adaptation, and intestinal stem cell regeneration.

Science.gov (United States)

Schall, K A; Holoyda, K A; Grant, C N; Levin, D E; Torres, E R; Maxwell, A; Pollack, H A; Moats, R A; Frey, M R; Darehzereshki, A; Al Alam, D; Lien, C; Grikscheit, T C

2015-08-01

Loss of significant intestinal length from congenital anomaly or disease may lead to short bowel syndrome (SBS); intestinal failure may be partially offset by a gain in epithelial surface area, termed adaptation. Current in vivo models of SBS are costly and technically challenging. Operative times and survival rates have slowed extension to transgenic models. We created a new reproducible in vivo model of SBS in zebrafish, a tractable vertebrate model, to facilitate investigation of the mechanisms of intestinal adaptation. Proximal intestinal diversion at segment 1 (S1, equivalent to jejunum) was performed in adult male zebrafish. SBS fish emptied distal intestinal contents via stoma as in the human disease. After 2 wk, S1 was dilated compared with controls and villus ridges had increased complexity, contributing to greater villus epithelial perimeter. The number of intervillus pockets, the intestinal stem cell zone of the zebrafish increased and contained a higher number of bromodeoxyuridine (BrdU)-labeled cells after 2 wk of SBS. Egf receptor and a subset of its ligands, also drivers of adaptation, were upregulated in SBS fish. Igf has been reported as a driver of intestinal adaptation in other animal models, and SBS fish exposed to a pharmacological inhibitor of the Igf receptor failed to demonstrate signs of intestinal adaptation, such as increased inner epithelial perimeter and BrdU incorporation. We describe a technically feasible model of human SBS in the zebrafish, a faster and less expensive tool to investigate intestinal stem cell plasticity as well as the mechanisms that drive intestinal adaptation. Copyright © 2015 the American Physiological Society.

A constrained Metropolis-Hastings search for EMRIs in the Mock LISA Data Challenge 1B

International Nuclear Information System (INIS)

Gair, Jonathan R; Porter, Edward; Babak, Stanislav; Barack, Leor

2008-01-01

We describe a search for the extreme-mass-ratio inspiral sources in the Round 1B Mock LISA Data Challenge data sets. The search algorithm is a Monte Carlo search based on the Metropolis-Hastings algorithm, but also incorporates simulated, thermostated and time annealing, plus a harmonic identification stage designed to reduce the chance of the chain locking onto secondary maxima. In this paper, we focus on describing the algorithm that we have been developing. We give the results of the search of the Round 1B data, although parameter recovery has improved since that deadline. Finally, we describe several modifications to the search pipeline that we are currently investigating for incorporation in future searches

Small Intestinal Infections.

Science.gov (United States)

Munot, Khushboo; Kotler, Donald P

2016-06-01

Small intestinal infections are extremely common worldwide. They may be bacterial, viral, or parasitic in etiology. Most are foodborne or waterborne, with specific etiologies differing by region and with diverse pathophysiologies. Very young, very old, and immune-deficient individuals are the most vulnerable to morbidity or mortality from small intestinal infections. There have been significant advances in diagnostic sophistication with the development and early application of molecular diagnostic assays, though these tests have not become mainstream. The lack of rapid diagnoses combined with the self-limited nature of small intestinal infections has hampered the development of specific and effective treatments other than oral rehydration. Antibiotics are not indicated in the absence of an etiologic diagnosis, and not at all in the case of some infections.

Intestinal microbiota in healthy adults: temporal analysis reveals individual and common core and relation to intestinal symptoms.

Directory of Open Access Journals (Sweden)

Jonna Jalanka-Tuovinen

Full Text Available While our knowledge of the intestinal microbiota during disease is accumulating, basic information of the microbiota in healthy subjects is still scarce. The aim of this study was to characterize the intestinal microbiota of healthy adults and specifically address its temporal stability, core microbiota and relation with intestinal symptoms. We carried out a longitudinal study by following a set of 15 healthy Finnish subjects for seven weeks and regularly assessed their intestinal bacteria and archaea with the Human Intestinal Tract (HIT Chip, a phylogenetic microarray, in conjunction with qPCR analyses. The health perception and occurrence of intestinal symptoms was recorded by questionnaire at each sampling point.A high overall temporal stability of the microbiota was observed. Five subjects showed transient microbiota destabilization, which correlated not only with the intake of antibiotics but also with overseas travelling and temporary illness, expanding the hitherto known factors affecting the intestinal microbiota. We identified significant correlations between the microbiota and common intestinal symptoms, including abdominal pain and bloating. The most striking finding was the inverse correlation between Bifidobacteria and abdominal pain: subjects who experienced pain had over five-fold less Bifidobacteria compared to those without pain. Finally, a novel computational approach was used to define the common core microbiota, highlighting the role of the analysis depth in finding the phylogenetic core and estimating its size. The in-depth analysis suggested that we share a substantial number of our intestinal phylotypes but as they represent highly variable proportions of the total community, many of them often remain undetected.A global and high-resolution microbiota analysis was carried out to determine the temporal stability, the associations with intestinal symptoms, and the individual and common core microbiota in healthy adults. The

Small Intestine Cancer—Health Professional Version

Science.gov (United States)

Adenocarcinoma is the most common type of small intestine cancer. Other types of small intestine cancer are sarcomas, carcinoid tumors, gastrointestinal stromal tumors, and lymphomas. Find evidence-based information on small intestine cancer treatment, research, and statistics.

Parenteral Nutrition and Intestinal Failure.

Science.gov (United States)

Bielawska, Barbara; Allard, Johane P

2017-05-06

Severe short bowel syndrome (SBS) is a major cause of chronic (Type 3) intestinal failure (IF) where structural and functional changes contribute to malabsorption and risk of micronutrient deficiencies. Chronic IF may be reversible, depending on anatomy and intestinal adaptation, but most patients require long-term nutritional support, generally in the form of parenteral nutrition (PN). SBS management begins with dietary changes and pharmacologic therapies taking into account individual anatomy and physiology, but these are rarely sufficient to avoid PN. New hormonal therapies targeting intestinal adaptation hold promise. Surgical options for SBS including intestinal transplant are available, but have significant limitations. Home PN (HPN) is therefore the mainstay of treatment for severe SBS. HPN involves chronic administration of macronutrients, micronutrients, fluid, and electrolytes via central venous access in the patient's home. HPN requires careful clinical and biochemical monitoring. Main complications of HPN are related to venous access (infection, thrombosis) and metabolic complications including intestinal failure associated liver disease (IFALD). Although HPN significantly impacts quality of life, outcomes are generally good and survival is mostly determined by the underlying disease. As chronic intestinal failure is a rare disease, registries are a promising strategy for studying HPN patients to improve outcomes.

Determination of Intestine Inflammation Markers in Diagnostic Search in Children with Intestinal Diseases

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N.V. Pavlenko

2016-08-01

Full Text Available Introduction. Prevalence of bowel diseases in children is the second, trailing only the diseases of gastroduodenal zone and growing in recent years. Actual one is the problem of differential diagnosis of functional and inflammatory intestinal diseases using non-invasive methods on the prehospital stage and as a screening. Objective. Comparative analysis of fecal markers of the bowel inflammation (lactoferrine and calprotectine with endoscopy and morphology of intestinal mucosa in children. Matherials and methods. 49 children aged 6–18 years were examined. All patients underwent endoscopic and morphological study of the intestine, coprotest, determination of fecal markers of bowel inflammation (lactoferrin and calprotectine. Results. It is shown that in young children, the intestinal mucosa mainly hadn’t endoscopic changes, coprotest and morphological examination didn’t reveal the signs of inflammation, fecal intestinal inflammation markers were negative (p < 0.05. In the group of older children, moderate or marked catarrhal changes were found endoscopically, coprotest results were typical of inflammation in the intestines, it was morphologically proved the presence of chronic inflammation of the mucous membrane of the colon with signs of atrophy, the results of lactoferrin and calprotectine determination were positive (p < 0.05. Conclusion. The findings suggest that the evaluation of calprotectine and lactoferrin can be used in pediatric patients because of its non-invasiveness as diagnostic screening for the selection of patients for the further endoscopic examination and diagnostic search.

Intestinal spirochetosis and colon diverticulosis Espiroquetose intestinal e diverticulose do cólon

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Marcus Aurelho de Lima

2005-02-01

Full Text Available A case of intestinal spirochetosis in a 62-year-old white male is reported. The condition was characterized by chronic flatulence and episodes of intestinal hemorrhage, in addition to the evidence of hypotonic diverticular disease, with a large number of slender organisms in the colon epithelium and cryptae. Spirochetes were demonstrated by Whartin-Starry stain. The serologic tests for syphilis and HIV were positive. Spirochetosis was treated with penicillin G, and the patient remains free of intestinal complaints 20 months later.Um caso de espiroquetose intestinal é relatado em um homem branco de 62 anos. A condição foi caracterizada por flatulência crônica e episódios de hemorragia intestinal, além da evidência de doença diverticular hipotônica dos cólons, com numerosos organismos filamentosos no epitélio e nas criptas do cólon. Os espiroquetas foram demonstrados pela coloração de Whartin-Starry. Os testes sorológicos para sífilis e HIV foram positivos. A espiroquetose foi tratada com penicilina G e o paciente permanece sem queixas intestinais após 20 meses.

Intestinal epithelium in inflammatory bowel disease

DEFF Research Database (Denmark)

Coskun, Mehmet

2014-01-01

The intestinal epithelium has a strategic position as a protective physical barrier to luminal microbiota and actively contributes to the mucosal immune system. This barrier is mainly formed by a monolayer of specialized intestinal epithelial cells (IECs) that are crucial in maintaining intestinal...... of inflammatory bowel disease (IBD). Understanding the role of the intestinal epithelium in IBD pathogenesis might contribute to an improved knowledge of the inflammatory processes and the identification of potential therapeutic targets....

Primary intestinal lymphangiectasia (Waldmann's disease).

Science.gov (United States)

Vignes, Stéphane; Bellanger, Jérôme

2008-02-22

Primary intestinal lymphangiectasia (PIL) is a rare disorder characterized by dilated intestinal lacteals resulting in lymph leakage into the small bowel lumen and responsible for protein-losing enteropathy leading to lymphopenia, hypoalbuminemia and hypogammaglobulinemia. PIL is generally diagnosed before 3 years of age but may be diagnosed in older patients. Prevalence is unknown. The main symptom is predominantly bilateral lower limb edema. Edema may be moderate to severe with anasarca and includes pleural effusion, pericarditis or chylous ascites. Fatigue, abdominal pain, weight loss, inability to gain weight, moderate diarrhea or fat-soluble vitamin deficiencies due to malabsorption may also be present. In some patients, limb lymphedema is associated with PIL and is difficult to distinguish lymphedema from edema. Exsudative enteropathy is confirmed by the elevated 24-h stool alpha1-antitrypsin clearance. Etiology remains unknown. Very rare familial cases of PIL have been reported. Diagnosis is confirmed by endoscopic observation of intestinal lymphangiectasia with the corresponding histology of intestinal biopsy specimens. Videocapsule endoscopy may be useful when endoscopic findings are not contributive. Differential diagnosis includes constrictive pericarditis, intestinal lymphoma, Whipple's disease, Crohn's disease, intestinal tuberculosis, sarcoidosis or systemic sclerosis. Several B-cell lymphomas confined to the gastrointestinal tract (stomach, jejunum, midgut, ileum) or with extra-intestinal localizations were reported in PIL patients. A low-fat diet associated with medium-chain triglyceride supplementation is the cornerstone of PIL medical management. The absence of fat in the diet prevents chyle engorgement of the intestinal lymphatic vessels thereby preventing their rupture with its ensuing lymph loss. Medium-chain triglycerides are absorbed directly into the portal venous circulation and avoid lacteal overloading. Other inconsistently effective

Primary intestinal lymphangiectasia (Waldmann's disease

Directory of Open Access Journals (Sweden)

Bellanger Jérôme

2008-02-01

Full Text Available Abstract Primary intestinal lymphangiectasia (PIL is a rare disorder characterized by dilated intestinal lacteals resulting in lymph leakage into the small bowel lumen and responsible for protein-losing enteropathy leading to lymphopenia, hypoalbuminemia and hypogammaglobulinemia. PIL is generally diagnosed before 3 years of age but may be diagnosed in older patients. Prevalence is unknown. The main symptom is predominantly bilateral lower limb edema. Edema may be moderate to severe with anasarca and includes pleural effusion, pericarditis or chylous ascites. Fatigue, abdominal pain, weight loss, inability to gain weight, moderate diarrhea or fat-soluble vitamin deficiencies due to malabsorption may also be present. In some patients, limb lymphedema is associated with PIL and is difficult to distinguish lymphedema from edema. Exsudative enteropathy is confirmed by the elevated 24-h stool α1-antitrypsin clearance. Etiology remains unknown. Very rare familial cases of PIL have been reported. Diagnosis is confirmed by endoscopic observation of intestinal lymphangiectasia with the corresponding histology of intestinal biopsy specimens. Videocapsule endoscopy may be useful when endoscopic findings are not contributive. Differential diagnosis includes constrictive pericarditis, intestinal lymphoma, Whipple's disease, Crohn's disease, intestinal tuberculosis, sarcoidosis or systemic sclerosis. Several B-cell lymphomas confined to the gastrointestinal tract (stomach, jejunum, midgut, ileum or with extra-intestinal localizations were reported in PIL patients. A low-fat diet associated with medium-chain triglyceride supplementation is the cornerstone of PIL medical management. The absence of fat in the diet prevents chyle engorgement of the intestinal lymphatic vessels thereby preventing their rupture with its ensuing lymph loss. Medium-chain triglycerides are absorbed directly into the portal venous circulation and avoid lacteal overloading. Other

A etiological factors in mechanical intestinal obstruction

International Nuclear Information System (INIS)

Asad, S.; Khan, H.; Khan, I.A.; Ghaffar, S.; Rehman, Z.U.

2012-01-01

Background: Intestinal obstruction occurs when the normal flow of intestinal contents is interrupted. The most frequent causes of intestinal obstruction are postoperative adhesions and hernias, which cause extrinsic compression of the intestine. Less frequently, tumours or strictures of the bowel can cause intrinsic blockage. Objective of the study was to find out the various a etiological factors of mechanical intestinal obstruction and to evaluate the morbidity and mortality in adult patients presenting to Surgical 'A' unit of Ayub teaching hospital with mechanical intestinal obstruction. Methods: This cross-sectional study was conducted from March 2009 to September, 2009. All patients presenting with intestinal obstruction and were above the age of 12 years were included in the study. Patients with non-mechanical obstruction were excluded from the study and those who responded to conservative measures were also excluded. Results: A total of 36 patients with age ranging from 12 to 80 years (Mean age 37.72+-19.74 years) and male to female ratio of 1.77:1, were treated for mechanical intestinal obstruction. The most common cause for mechanical intestinal obstruction was adhesions (36.1%). Intestinal tuberculosis was the second most common cause (19.4%), while hernias and sigmoid volvulus affected 13.9% patients each. Malignancies were found in 5.6% cases. Conclusion: Adhesions and Tuberculosis are the leading causes of mechanical intestinal obstruction in Pakistan. Although some patients can be treated conservatively, a substantial portion requires immediate surgical intervention. (author)

The extent of intestinal failure-associated liver disease in patients referred for intestinal rehabilitation is associated with increased mortality: an analysis of the pediatric intestinal failure consortium database.

Science.gov (United States)

Javid, Patrick J; Oron, Assaf P; Duggan, Christopher; Squires, Robert H; Horslen, Simon P

2017-09-05

The advent of regional multidisciplinary intestinal rehabilitation programs has been associated with improved survival in pediatric intestinal failure. Yet, the optimal timing of referral for intestinal rehabilitation remains unknown. We hypothesized that the degree of intestinal failure-associated liver disease (IFALD) at initiation of intestinal rehabilitation would be associated with overall outcome. The multicenter, retrospective Pediatric Intestinal Failure Consortium (PIFCon) database was used to identify all subjects with baseline bilirubin data. Conjugated bilirubin (CBili) was used as a marker for IFALD, and we stratified baseline bilirubin values as CBili4 mg/dL. The association between baseline CBili and mortality was examined using Cox proportional hazards regression. Of 272 subjects in the database, 191 (70%) children had baseline bilirubin data collected. 38% and 28% of patients had CBili >4 mg/dL and CBili 4 mg/dL, prematurity, race, and small bowel atresia. On regression analysis controlling for age, prematurity, and diagnosis, the risk of mortality was increased by 3-fold for baseline CBili 2-4 mg/dL (HR 3.25 [1.07-9.92], p=0.04) and 4-fold for baseline CBili >4 mg/dL (HR 4.24 [1.51-11.92], p=0.006). On secondary analysis, CBili >4 mg/dL at baseline was associated with a lower chance of attaining enteral autonomy. In children with intestinal failure treated at intestinal rehabilitation programs, more advanced IFALD at referral is associated with increased mortality and decreased prospect of attaining enteral autonomy. Early referral of children with intestinal failure to intestinal rehabilitation programs should be strongly encouraged. Treatment Study, Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

[An experimental assessment of methods for applying intestinal sutures in intestinal obstruction].

Science.gov (United States)

Akhmadudinov, M G

1992-04-01

The results of various methods used in applying intestinal sutures in obturation were studied. Three series of experiments were conducted on 30 dogs--resection of the intestine after obstruction with the formation of anastomoses by means of double-row suture (Albert--Shmiden--Lambert) in the first series (10 dogs), by a single-row suture after V. M. Mateshchuk [correction of Mateshuku] in the second series, and bu a single-row stretching suture suggested by the author in the third series. The postoperative complications and the parameters of physical airtightness of the intestinal anastomosis were studied in dynamics in the experimental animals. The results of the study: incompetence of the anastomosis sutures in the first series 6, in the second 4, and in the third series one. Adhesions occurred in all animals of the first and second series and in 2 of the third series. Six dogs of the first series died, 4 of the second, and one of the third. Study of the dynamics of the results showed a direct connection of the complications with the parameters of the physical airtightness of the anastomosis, and the last-named with the method of the intestinal suture. Relatively better results were noted in formation of the anastomosis by means of our suggested stretshing continuous suture passed through the serous, muscular, and submucous coats of the intestine.

Update on small intestinal stem cells

OpenAIRE

Tesori, Valentina; Puglisi, Maria Ausiliatrice; Lattanzi, Wanda; Gasbarrini, Giovanni Battista; Gasbarrini, Antonio

2013-01-01

Among somatic stem cells, those residing in the intestine represent a fascinating and poorly explored research field. Particularly, somatic stem cells reside in the small intestine at the level of the crypt base, in a constant balance between self-renewal and differentiation. Aim of the present review is to delve into the mechanisms that regulate the delicate equilibrium through which intestinal stem cells orchestrate intestinal architecture. To this aim, special focus will be addressed to id...

Auxiliary functions of the LISA laser link: ranging, clock noise transfer and data communication

International Nuclear Information System (INIS)

Heinzel, Gerhard; Esteban, Juan Jose; Barke, Simon; Otto, Markus; Wang Yan; Garcia, Antonio F; Danzmann, Karsten

2011-01-01

The Laser Interferometer Space Antenna (LISA) is required to reduce two important noise sources by post-processing on the ground using time-delay interferometry (TDI): phase noise of the on-board reference clocks and laser frequency noise. To achieve the desired suppression, the TDI algorithm needs measurements of the differential clock noise between any two spacecraft and inter-spacecraft ranging measurements with at least 1 m accuracy, which is beyond the precision of ground-based measurements for deep space missions. Therefore, we need on-board measurements by transmitting clock noise and ranging information between the spacecraft as auxiliary functions of the laser link. This paper reports our current experimental results in clock noise transfer and ranging for noise subtraction via post-processing as well as additional data transfer.

Prophylactic Ozone Administration Reduces Intestinal Mucosa Injury Induced by Intestinal Ischemia-Reperfusion in the Rat

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Ozkan Onal

2015-01-01

Full Text Available Objectives. Intestinal ischemia-reperfusion injury is associated with mucosal damage and has a high rate of mortality. Various beneficial effects of ozone have been shown. The aim of the present study was to show the effects of ozone in ischemia reperfusion model in intestine. Material and Method. Twenty eight Wistar rats were randomized into four groups with seven rats in each group. Control group was administered serum physiologic (SF intraperitoneally (ip for five days. Ozone group was administered 1 mg/kg ozone ip for five days. Ischemia Reperfusion (IR group underwent superior mesenteric artery occlusion for one hour and then reperfusion for two hours. Ozone + IR group was administered 1 mg/kg ozone ip for five days and at sixth day IR model was applied. Rats were anesthetized with ketamine∖xyzlazine and their intracardiac blood was drawn completely and they were sacrificed. Intestinal tissue samples were examined under light microscope. Levels of superoxide dismutase (SOD, catalase (CAT, glutathioneperoxidase (GSH-Px, malondyaldehide (MDA, and protein carbonyl (PCO were analyzed in tissue samples. Total oxidant status (TOS, and total antioxidant capacity (TAC were analyzed in blood samples. Data were evaluated statistically by Kruskal Wallis test. Results. In the ozone administered group, degree of intestinal injury was not different from the control group. IR caused an increase in intestinal injury score. The intestinal epithelium maintained its integrity and decrease in intestinal injury score was detected in Ozone + IR group. SOD, GSH-Px, and CAT values were high in ozone group and low in IR. TOS parameter was highest in the IR group and the TAC parameter was highest in the ozone group and lowest in the IR group. Conclusion. In the present study, IR model caused an increase in intestinal injury.In the present study, ozone administration had an effect improving IR associated tissue injury. In the present study, ozone therapy

Measuring fN force variations in the presence of constant nN forces: a torsion pendulum ground test of the LISA Pathfinder free-fall mode

Science.gov (United States)

Russano, G.; Cavalleri, A.; Cesarini, A.; Dolesi, R.; Ferroni, V.; Gibert, F.; Giusteri, R.; Hueller, M.; Liu, L.; Pivato, P.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Weber, W. J.

2018-02-01

LISA Pathfinder is a differential accelerometer with the main goal being to demonstrate the near perfect free-fall of reference test masses, as is needed for an orbiting gravitational wave observatory, with a target sensitivity of 30 fm s‑2 Hz-1/2 at 1 mHz. Any lasting background differential acceleration between the two test masses must be actively compensated, and noise associated with the applied actuation force can be a dominant source of noise. To remove this actuation, and the associated force noise, a ‘free-fall’ actuation control scheme has been designed; actuation is limited to brief impulses, with both test masses in free-fall in the time between the impulses, allowing measurement of the remaining acceleration noise sources. In this work, we present an on-ground torsion pendulum testing campaign of this technique and associated data analysis algorithms at a level nearing the sub-femto-g/\\sqrtHz performance required for LISA Pathfinder.

Very late onset small intestinal B cell lymphoma associated with primary intestinal lymphangiectasia and diffuse cutaneous warts

OpenAIRE

Bouhnik, Y; Etienney, I; Nemeth, J; Thevenot, T; Lavergne-Slove, A; Matuchansky, C

2000-01-01

As only a handful of lymphoma cases have been reported in conjunction with primary intestinal lymphangiectasia, it is not yet clear if this association is merely fortuitous or related to primary intestinal lymphangiectasia induced immune deficiency. We report on two female patients, 50 and 58 years old, who developed small intestinal high grade B cell lymphoma a long time (45 and 40 years, respectively) after the initial clinical manifestations of primary intestinal lymphangiectasia. They pre...

The effect of fucoidan on intestinal flora and intestinal barrier function in rats with breast cancer.

Science.gov (United States)

Xue, Meilan; Ji, Xinqiang; Liang, Hui; Liu, Ying; Wang, Bing; Sun, Lingling; Li, Weiwei

2018-02-21

Recent research studies have shown that the intestinal flora are related to the occurrence and progress of breast cancer. This study investigates the effect of fucoidan on intestinal flora and intestinal barrier function in rats with 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancers. Sixty female Sprague-Dawley rats were randomly assigned to the control group, the model group, and the F1 and F2 groups, which were fed fucoidan at concentrations of 200 and 400 mg per kg bw (body weight), respectively. Intestinal histopathological analysis was performed and 16S rDNA high-throughput sequencing was used to provide an overview of the intestinal flora composition. The contents of d-lactic acid (d-LA), diamine oxidase (DAO) and endotoxin in plasma were detected by ELISA. Expression levels of the tight junction (TJ) proteins, phosphorylated p38 MAPK and ERK1/2 were measured using western blotting. Our results suggested that the intestinal wall of the model group was damaged. However, after fucoidan intervention, the villi were gradually restored. ELISA showed that the levels of plasma endotoxin, d-LA and DAO decreased in the F1 and F2 groups compared to those in the model group. Fucoidan treatment also increased the expressions of ZO-1, occludin, claudin-1 and claudin-8. Furthermore, the expression levels of phosphorylated p38 MAPK and ERK1/2 were upregulated in fucoidan treatment groups. The results of 16S rDNA high-throughput sequencing indicated that fucoidan increased the diversity of the intestinal microbiota and induced changes in microbial composition, with the increased Bacteroidetes/Firmicutes phylum ratio. In conclusion, the supplement of fucoidan could improve the fecal microbiota composition and repair the intestinal barrier function. The study suggested the use of fucoidan as an intestinal flora modulator for potential prevention of breast cancer.

[Morphological changes of the intestine in experimental acute intestinal infection in the treatment of colloidal silver].

Science.gov (United States)

Polov'ian, E S; Chemich, N D; Moskalenko, R A; Romaniuk, A N

2012-06-01

At the present stage of infectionist practice in the treatment of acute intestinal infections caused by opportunistic microorganisms, colloidal silver is used with a particle size of 25 nm as an alternative to conventional causal therapy. In 32 rats, distributed in 4 groups of 8 animals each (intact; healthy, got colloidal silver; with a modeled acute intestinal infection in the basic treatment and with the addition of colloidal silver), histological examination was performed of small and large intestine of rats. Oral administration of colloidal silver at a dose of 0.02 mg/day to intact rats did not lead to changes in morphometric parameters compared to the norm, and during early convalescence in rats with acute intestinal infections were observed destructive and compensatory changes in the intestine, which depended on the treatment regimen. With the introduction of colloidal silver decreased activity of the inflammatory process and the severity of morphological changes in tissues of small and large intestine, indicating that the positive effect of study drug compared with baseline therapy.

Activated STAT5 Confers Resistance to Intestinal Injury by Increasing Intestinal Stem Cell Proliferation and Regeneration

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Shila Gilbert

2015-02-01

Full Text Available Intestinal epithelial stem cells (IESCs control the intestinal homeostatic response to inflammation and regeneration. The underlying mechanisms are unclear. Cytokine-STAT5 signaling regulates intestinal epithelial homeostasis and responses to injury. We link STAT5 signaling to IESC replenishment upon injury by depletion or activation of Stat5 transcription factor. We found that depletion of Stat5 led to deregulation of IESC marker expression and decreased LGR5+ IESC proliferation. STAT5-deficient mice exhibited worse intestinal histology and impaired crypt regeneration after γ-irradiation. We generated a transgenic mouse model with inducible expression of constitutively active Stat5. In contrast to Stat5 depletion, activation of STAT5 increased IESC proliferation, accelerated crypt regeneration, and conferred resistance to intestinal injury. Furthermore, ectopic activation of STAT5 in mouse or human stem cells promoted LGR5+ IESC self-renewal. Accordingly, STAT5 promotes IESC proliferation and regeneration to mitigate intestinal inflammation. STAT5 is a functional therapeutic target to improve the IESC regenerative response to gut injury.

Radiation-induced recurrent intestinal pseudo-obstruction

International Nuclear Information System (INIS)

Conklin, J.L.; Anuras, S.

1981-01-01

The syndrome of intestinal pseudo-obstruction is a complex of signs and symptoms of intestinal obstruction without evidence of mechanical obstruction of the intestinal lumen. A patient with radiation-induced intestinal pseudoobstruction is described. The patient is a 74-year old woman with a history of chronic diarrhea, recurrent episodes of crampy abdominal pain, nausea and vomiting since receiving a 13,000 rad radiation dose to the pelvis in 1954. She has been hospitalized on many occasions for symptoms and signs of bowel obstruction. Upper gastrointestinal contrast roentgenograms with small bowel follow-through done during these episodes revealed multiple dilated loops of small bowel with no obstructing lesion. Barium enemas revealed no obstructing lesion. Each episode resolved with conservative therapy. Other secondary causes for intestinal pseudo-obstruction were ruled out in our patient. She gave no history of familial gastrointestinal disorders. Although postirradiation motility abnormalities have been demonstrated experimentally this is the first report of radiation induced intestinal pseudo-obstruction

Fish oil enhances recovery of intestinal microbiota and epithelial integrity in chronic rejection of intestinal transplant.

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Qiurong Li

Full Text Available BACKGROUND: The intestinal chronic rejection (CR is the major limitation to long-term survival of transplanted organs. This study aimed to investigate the interaction between intestinal microbiota and epithelial integrity in chronic rejection of intestinal transplantation, and to find out whether fish oil enhances recovery of intestinal microbiota and epithelial integrity. METHODS/PRINCIPAL FINDINGS: The luminal and mucosal microbiota composition of CR rats were characterized by DGGE analysis at 190 days after intestinal transplant. The specific bacterial species were determined by sequence analysis. Furthermore, changes in the localization of intestinal TJ proteins were examined by immunofluorescent staining. PCR-DGGE analysis revealed that gut microbiota in CR rats had a shift towards Escherichia coli, Bacteroides spp and Clostridium spp and a decrease in the abundance of Lactobacillales bacteria in the intestines. Fish oil supplementation could enhance the recovery of gut microbiota, showing a significant decrease of gut bacterial proportions of E. coli and Bacteroides spp and an increase of Lactobacillales spp. In addition, CR rats showed pronounced alteration of tight junction, depicted by marked changes in epithelial cell ultrastructure and redistribution of occuldin and claudins as well as disruption in TJ barrier function. Fish oil administration ameliorated disruption of epithelial integrity in CR, which was associated with an improvement of the mucosal structure leading to improved tight junctions. CONCLUSIONS/SIGNIFICANCE: Our study have presented novel evidence that fish oil is involved in the maintenance of epithelial TJ integrity and recovery of gut microbiota, which may have therapeutic potential against CR in intestinal transplantation.

Lipo sarcoma in small intestine

International Nuclear Information System (INIS)

Rodriguez Iglesias, J.; Pineyro Gutierrez, A.; Taroco Medeiros, L.; Fein Kolodny, C.; Navarrete Pedocchi, H.

1987-01-01

A case is presented by primitive liposarcoma in small intestine , an extensive bibliographical review foreigner and national in this case. It detach the exceptional of the intestinal topography of the liposarcomas; and making stress in the relative value of the computerized tomography and ultrasonography in the diagnose of the small intestine tumors . As well as in the sarcomas of another topography, chemo and radiotherapy associated to the exeresis surgery, it can be of benefit [es

[Intrauterine intestinal volvulus].

Science.gov (United States)

Gawrych, Elzbieta; Chojnacka, Hanna; Wegrzynowski, Jerzy; Rajewska, Justyna

2009-07-01

Intrauterine intestinal volvulus is an extremely rare case of acute congenital intestinal obstruction. The diagnosis is usually possible in the third trimester of a pregnancy. Fetal midgut volvulus is most likely to be recognized by observing a typical clockwise whirlpool sign during color Doppler investigation. Multiple dilated intestinal loops with fluid levels are usually visible during the antenatal ultrasound as well. Physical and radiographic findings in the newborn indicate intestinal obstruction and an emergency surgery is required. The authors describe intrauterine volvulus in 3 female newborns in which surgical treatment was individualized. The decision about primary or delayed anastomosis after resection of the gangrenous part of the small bowel was made at the time of the surgery and depended on the general condition of the newborn, as well as presence or absence of meconium peritonitis. Double loop jejunostomy was performed in case of two newborns, followed by a delayed end-to-end anastomosis. In case of the third newborn, good blood supply of the small intestine after untwisting and 0.25% lignocaine injections into mesentery led to the assumption that the torsion was not complete and ischemia was reversible. In the two cases of incomplete rotation the cecum was sutured to the left abdominal wall to prevent further twisting. The postoperative course was uneventful and oral alimentation caused no problems. Physical development of all these children has been normal (current age: 1-2 years) and the parents have not observed any disorders or problems regarding passage of food through the alimentary canal. Prompt antenatal diagnosis of this surgical emergency and adequate choice of intervention may greatly reduce mortality due to intrauterine volvulus.

Exercise and the gastro-intestinal tract

African Journals Online (AJOL)

on perfonnance and me value of cardiovascular training in improving performance in aerobic sports is well recognised. The role of me gastro-intestinal tracr, bom as a limiting and sustaining facror in aerobic exercises, is less well appreciared. Gastro-intestinal symptoms. The spectrum of gastro-intestinal effecrs of exercise ...

Epidermal Growth Factor and Intestinal Barrier Function

Directory of Open Access Journals (Sweden)

Xiaopeng Tang

2016-01-01

Full Text Available Epidermal growth factor (EGF is a 53-amino acid peptide that plays an important role in regulating cell growth, survival, migration, apoptosis, proliferation, and differentiation. In addition, EGF has been established to be an effective intestinal regulator helping to protect intestinal barrier integrity, which was essential for the absorption of nutrients and health in humans and animals. Several researches have demonstrated that EGF via binding to the EGF receptor and subsequent activation of Ras/MAPK, PI3K/AKT, PLC-γ/PKC, and STATS signal pathways regulates intestinal barrier function. In this review, the relationship between epidermal growth factor and intestinal development and intestinal barrier is described, to provide a better understanding of the effects of EGF on intestine development and health.

Thyroid hormone regulation of adult intestinal stem cells: Implications on intestinal development and homeostasis.

Science.gov (United States)

Sun, Guihong; Roediger, Julia; Shi, Yun-Bo

2016-12-01

Organ-specific adult stem cells are essential for organ homeostasis, tissue repair and regeneration. The formation of such stem cells often takes place during postembryonic development, a period around birth in mammals when plasma thyroid hormone concentration is high. The life-long self-renewal of the intestinal epithelium has made mammalian intestine a valuable model to study the function and regulation and adult stem cells. On the other hand, much less is known about how the adult intestinal stem cells are formed during vertebrate development. Here, we will review some recent progresses on this subject, focusing mainly on the formation of the adult intestine during Xenopus metamorphosis. We will discuss the role of thyroid hormone signaling pathway in the process and potential molecular conservations between amphibians and mammals as well as the implications in organ homeostasis and human diseases.

Isotopic identification of intestinal strangulation

International Nuclear Information System (INIS)

Anderson, M.C.; Selby, J.B.

1982-01-01

A small series of eleven dogs prepared with a strangulating segment of jejunum demonstrated that a radionuclide, 99 mTc-labelled albumin, concentrates in the lumen and bowel wall of the affected intestinal segment. Modern scanning equipment accurately localized the strangulating loop. This technique has the potential of identifying patients with intestinal obstruction, in whom strangulation is a factor, prior to the development of impaired arterial inflow and frank gangrene. These findings confirmed earlier obstructions that were reported when nuclear scanning instrumentation was less sophisticated. Identification of patients at risk for intestinal strangulation requires a high index of suspicion. Excruciating cramping abdominal pain out of proportion to physical findings, roentgenogram evidence, and laboratory studies should alert the physician to the possibility of intestinal ischemia and closed loop obstruction. Radionuclide scanning in such cases may be of assistance in defining or excluding the diagnosis of a strangulating mechanism. The test is simple, relatively economical, and represents a low risk procedure to patients. It would have no place when the classic physical and laboratory findings of intestinal infarction are present

Isotopic identification of intestinal strangulation

Energy Technology Data Exchange (ETDEWEB)

Anderson, M.C.; Selby, J.B.

1982-12-01

A small series of eleven dogs prepared with a strangulating segment of jejunum demonstrated that a radionuclide, /sup 99/mTc-labelled albumin, concentrates in the lumen and bowel wall of the affected intestinal segment. Modern scanning equipment accurately localized the strangulating loop. This technique has the potential of identifying patients with intestinal obstruction, in whom strangulation is a factor, prior to the development of impaired arterial inflow and frank gangrene. These findings confirmed earlier obstructions that were reported when nuclear scanning instrumentation was less sophisticated. Identification of patients at risk for intestinal strangulation requires a high index of suspicion. Excruciating cramping abdominal pain out of proportion to physical findings, roentgenogram evidence, and laboratory studies should alert the physician to the possibility of intestinal ischemia and closed loop obstruction. Radionuclide scanning in such cases may be of assistance in defining or excluding the diagnosis of a strangulating mechanism. The test is simple, relatively economical, and represents a low risk procedure to patients. It would have no place when the classic physical and laboratory findings of intestinal infarction are present.

Análise Bibliométrica da produção científica em gestão da informação na base de dados lisa / Bibliometrics analysis of scientific production in management information in the lisa database

OpenAIRE

Luiza da Silva Kleinubing

2010-01-01

Descreve e analisa as principais características bibliométricas das publicações relacionadas à área de gestão da informação da base de dados Lisa, uma das bases com maior visibilidade no campo da Biblioteconomia e Ciência da Informação. Foram analisados 138 artigos. A metodologia de pesquisa combina métodos bibliométricos e softwares, a característica da pesquisa é quantitativa, pois enumera e mede, e qualitativa, pois compreende e explica. Conclui-se sinalizando que os métodos bibliométricos...

Inference on white dwarf binary systems using the first round Mock LISA Data Challenges data sets

International Nuclear Information System (INIS)

Stroeer, Alexander; Veitch, John; Roever, Christian; Bloomer, Ed; Clark, James; Christensen, Nelson; Hendry, Martin; Messenger, Chris; Meyer, Renate; Pitkin, Matthew; Toher, Jennifer; Umstaetter, Richard; Vecchio, Alberto; Woan, Graham

2007-01-01

We report on the analysis of selected single source data sets from the first round of the mock LISA data challenges (MLDC) for white dwarf binaries. We implemented an end-to-end pipeline consisting of a grid-based coherent pre-processing unit for signal detection and an automatic Markov Chain Monte Carlo (MCMC) post-processing unit for signal evaluation. We demonstrate that signal detection with our coherent approach is secure and accurate, and is increased in accuracy and supplemented with additional information on the signal parameters by our Markov Chain Monte Carlo approach. We also demonstrate that the Markov Chain Monte Carlo routine is additionally able to determine accurately the noise level in the frequency window of interest

Small intestine aspirate and culture

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... ency/article/003731.htm Small intestine aspirate and culture To use the sharing features on this page, please enable JavaScript. Small intestine aspirate and culture is a lab test to check for infection ...

Prenatal intestinal volvulus: look for cystic fibrosis.

Science.gov (United States)

Chouikh, Taieb; Mottet, Nicolas; Cabrol, Christelle; Chaussy, Yann

2016-12-21

Intestinal volvulus is a life-threatening emergency requiring prompt surgical management. Prenatal intestinal volvulus is rare, and most are secondary to intestinal atresia, mesenteric defect or without any underlying cause. Cystic fibrosis (CF) is known to cause digestive tract disorders. After birth, 10-15% of newborns with CF may develop intestinal obstruction within a few days of birth because of meconial ileus. 1 This obstruction is a result of dehydrated thickened meconium obstructing the intestinal lumen. We report two cases of fetuses with prenatal diagnosis of segmental volvulus in whom CF was diagnosed. 2016 BMJ Publishing Group Ltd.

Telescoping Intestine in an Adult

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Khaldoon Shaheen

2013-01-01

Full Text Available Protrusion of a bowel segment into another (intussusception produces severe abdominal pain and culminates in intestinal obstruction. In adults, intestinal obstruction due to intussusception is relatively rare phenomenon, as it accounts for minority of intestinal obstructions in this population demographic. Organic lesion is usually identifiable as the cause of adult intussusceptions, neoplasms account for the majority. Therefore, surgical resection without reduction is almost always necessary and is advocated as the best treatment of adult intussusception. Here, we describe a rare case of a 44-year-old male with a diffuse large B-cell lymphoma involving the terminal ileum, which had caused ileocolic intussusception and subsequently developed intestinal obstruction requiring surgical intervention. This case emphasizes the importance of recognizing intussusception as the initial presentation for bowel malignancy.

Intestinal volvulus in cetaceans.

Science.gov (United States)

Begeman, L; St Leger, J A; Blyde, D J; Jauniaux, T P; Lair, S; Lovewell, G; Raverty, S; Seibel, H; Siebert, U; Staggs, S L; Martelli, P; Keesler, R I

2013-07-01

Intestinal volvulus was recognized as the cause of death in 18 cetaceans, including 8 species of toothed whales (suborder Odontoceti). Cases originated from 11 institutions from around the world and included both captive (n = 9) and free-ranging (n = 9) animals. When the clinical history was available (n = 9), animals consistently demonstrated acute dullness 1 to 5 days prior to death. In 3 of these animals (33%), there was a history of chronic gastrointestinal illness. The pathological findings were similar to those described in other animal species and humans, and consisted of intestinal volvulus and a well-demarcated segment of distended, congested, and edematous intestine with gas and bloody fluid contents. Associated lesions included congested and edematous mesentery and mesenteric lymph nodes, and often serofibrinous or hemorrhagic abdominal effusion. The volvulus involved the cranial part of the intestines in 85% (11 of 13). Potential predisposing causes were recognized in most cases (13 of 18, 72%) but were variable. Further studies investigating predisposing factors are necessary to help prevent occurrence and enhance early clinical diagnosis and management of the condition.

Update on small intestinal stem cells.

Science.gov (United States)

Tesori, Valentina; Puglisi, Maria Ausiliatrice; Lattanzi, Wanda; Gasbarrini, Giovanni Battista; Gasbarrini, Antonio

2013-08-07

Among somatic stem cells, those residing in the intestine represent a fascinating and poorly explored research field. Particularly, somatic stem cells reside in the small intestine at the level of the crypt base, in a constant balance between self-renewal and differentiation. Aim of the present review is to delve into the mechanisms that regulate the delicate equilibrium through which intestinal stem cells orchestrate intestinal architecture. To this aim, special focus will be addressed to identify the integrating signals from the surrounding niche, supporting a model whereby distinct cell populations facilitate homeostatic vs injury-induced regeneration.

Short Bowel Syndrome, a Case of Intestinal Rehabilitation

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Dianna Ramírez Prada

2015-05-01

Full Text Available Case: The objective is to present the successful experience of multidisciplinary management of a patient with short bowel syndrome and intestinal failure with progression to intestinal adaptation. This is a newly born premature with intestinal atresia type IV with multiple intestinal atresia who evolved to intestinal failure and required managed with prolonged parenteral nutritional support, multiple antibiotic schemes, prebiotics, multivitamins, enteral nutrition with elemental formula to achieve their adaptation intestinal until lead to a normal diet. The evolution of these patients intestinal failure is a challenge for the health team, as it not only involves the surgical management of your condition if not basic nutritional support, fluid and electrolyte balance, hepatic dysfunction cholestasis associated infections etc. Discussion: Short bowel syndrome with progression to intestinal failure in children is a condition whose prevalence is increasing worldwide, thanks to advances in neonatal intensive care, neonatal surgery, and nutritional support of patients with conditions such as gastroschisis, omphalocele and necrotizing enterocolitis. Despite the limitations of our health system, it is possible to offer a multidisciplinary and integrated to lead to intestinal adaptation treatment.

Precision cut intestinal slices are an appropriate ex vivo model to study NSAID-induced intestinal toxicity in rats

NARCIS (Netherlands)

Niu, Xiaoyu; de Graaf, Inge A. M.; van der Bij, Hendrik A.; Groothuis, Geny M. M.

2014-01-01

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used therapeutic agents, however, they are associated with a high prevalence of intestinal side effects. In this investigation, rat precision cut intestinal slices (PCIS) were evaluated as an ex vivo model to study NSAID-induced intestinal

INFANTS’ INTESTINAL COLICS. MODERN DATA

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N.I. Ursova

2011-01-01

Full Text Available The article analyzes modern data on infants’ intestinal colics. Peculiarities of nutrition, intestinal microbiocenose in healthy infants, methods of colcs’ correction are discussed. Author describes the principles of probiotics choice based on their clinical effectiveness in infants. Milk formula «Nan Comfort» can be useful in prophylaxis and treatment of functional disorders of gastrointestinal tract in children.Key words: infants, gastrointestinal tract, anatomy, physiology, intestinal colics, nutrition, probiotics.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2011; 10 (2: 125–131

Role of intestinal bacteria in gliadin-induced changes in intestinal mucosa: study in germ-free rats.

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Jana Cinova

Full Text Available BACKGROUND AND AIMS: Celiac disease (CD is a chronic inflammatory disorder of the small intestine that is induced by dietary wheat gluten proteins (gliadins in genetically predisposed individuals. The overgrowth of potentially pathogenic bacteria and infections has been suggested to contribute to CD pathogenesis. We aimed to study the effects of gliadin and various intestinal bacterial strains on mucosal barrier integrity, gliadin translocation, and cytokine production. METHODOLOGY/PRINCIPAL FINDINGS: Changes in gut mucosa were assessed in the intestinal loops of inbred Wistar-AVN rats that were reared under germ-free conditions in the presence of various intestinal bacteria (enterobacteria and bifidobacteria isolated from CD patients and healthy children, respectively and CD-triggering agents (gliadin and IFN-γ by histology, scanning electron microscopy, immunofluorescence, and a rat cytokine antibody array. Adhesion of the bacterial strains to the IEC-6 rat cell line was evaluated in vitro. Gliadin fragments alone or together with the proinflammatory cytokine interferon (IFN-γ significantly decreased the number of goblet cells in the small intestine; this effect was more pronounced in the presence of Escherichia coli CBL2 and Shigella CBD8. Shigella CBD8 and IFN-γ induced the highest mucin secretion and greatest impairment in tight junctions and, consequently, translocation of gliadin fragments into the lamina propria. Shigella CBD8 and E. coli CBL2 strongly adhered to IEC-6 epithelial cells. The number of goblet cells in small intestine increased by the simultaneous incubation of Bifidobacterium bifidum IATA-ES2 with gliadin, IFN-γ and enterobacteria. B. bifidum IATA-ES2 also enhanced the production of chemotactic factors and inhibitors of metalloproteinases, which can contribute to gut mucosal protection. CONCLUSIONS: Our results suggest that the composition of the intestinal microbiota affects the permeability of the intestinal mucosa

Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines.

Science.gov (United States)

Drago, Sandro; El Asmar, Ramzi; Di Pierro, Mariarosaria; Grazia Clemente, Maria; Tripathi, Amit; Sapone, Anna; Thakar, Manjusha; Iacono, Giuseppe; Carroccio, Antonio; D'Agate, Cinzia; Not, Tarcisio; Zampini, Lucia; Catassi, Carlo; Fasano, Alessio

2006-04-01

Little is known about the interaction of gliadin with intestinal epithelial cells and the mechanism(s) through which gliadin crosses the intestinal epithelial barrier. We investigated whether gliadin has any immediate effect on zonulin release and signaling. Both ex vivo human small intestines and intestinal cell monolayers were exposed to gliadin, and zonulin release and changes in paracellular permeability were monitored in the presence and absence of zonulin antagonism. Zonulin binding, cytoskeletal rearrangement, and zonula occludens-1 (ZO-1) redistribution were evaluated by immunofluorescence microscopy. Tight junction occludin and ZO-1 gene expression was evaluated by real-time polymerase chain reaction (PCR). When exposed to gliadin, zonulin receptor-positive IEC6 and Caco2 cells released zonulin in the cell medium with subsequent zonulin binding to the cell surface, rearrangement of the cell cytoskeleton, loss of occludin-ZO1 protein-protein interaction, and increased monolayer permeability. Pretreatment with the zonulin antagonist FZI/0 blocked these changes without affecting zonulin release. When exposed to luminal gliadin, intestinal biopsies from celiac patients in remission expressed a sustained luminal zonulin release and increase in intestinal permeability that was blocked by FZI/0 pretreatment. Conversely, biopsies from non-celiac patients demonstrated a limited, transient zonulin release which was paralleled by an increase in intestinal permeability that never reached the level of permeability seen in celiac disease (CD) tissues. Chronic gliadin exposure caused down-regulation of both ZO-1 and occludin gene expression. Based on our results, we concluded that gliadin activates zonulin signaling irrespective of the genetic expression of autoimmunity, leading to increased intestinal permeability to macromolecules.

Kaiso overexpression promotes intestinal inflammation and potentiates intestinal tumorigenesis in Apc(Min/+) mice.

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Pierre, Christina C; Longo, Joseph; Mavor, Meaghan; Milosavljevic, Snezana B; Chaudhary, Roopali; Gilbreath, Ebony; Yates, Clayton; Daniel, Juliet M

2015-09-01

Constitutive Wnt/β-catenin signaling is a key contributor to colorectal cancer (CRC). Although inactivation of the tumor suppressor adenomatous polyposis coli (APC) is recognized as an early event in CRC development, it is the accumulation of multiple subsequent oncogenic insults facilitates malignant transformation. One potential contributor to colorectal carcinogenesis is the POZ-ZF transcription factor Kaiso, whose depletion extends lifespan and delays polyp onset in the widely used Apc(Min/+) mouse model of intestinal cancer. These findings suggested that Kaiso potentiates intestinal tumorigenesis, but this was paradoxical as Kaiso was previously implicated as a negative regulator of Wnt/β-catenin signaling. To resolve Kaiso's role in intestinal tumorigenesis and canonical Wnt signaling, we generated a transgenic mouse model (Kaiso(Tg/+)) expressing an intestinal-specific myc-tagged Kaiso transgene. We then mated Kaiso(Tg/+) and Apc(Min/+) mice to generate Kaiso(Tg/+):Apc(Min/+) mice for further characterization. Kaiso(Tg/+):Apc(Min/+) mice exhibited reduced lifespan and increased polyp multiplicity compared to Apc(Min/+) mice. Consistent with this murine phenotype, we found increased Kaiso expression in human CRC tissue, supporting a role for Kaiso in human CRC. Interestingly, Wnt target gene expression was increased in Kaiso(Tg/+):Apc(Min/+) mice, suggesting that Kaiso's function as a negative regulator of canonical Wnt signaling, as seen in Xenopus, is not maintained in this context. Notably, Kaiso(Tg/+):Apc(Min/+) mice exhibited increased inflammation and activation of NFκB signaling compared to their Apc(Min/+) counterparts. This phenotype was consistent with our previous report that Kaiso(Tg/+) mice exhibit chronic intestinal inflammation. Together our findings highlight a role for Kaiso in promoting Wnt signaling, inflammation and tumorigenesis in the mammalian intestine. Copyright © 2015 Elsevier B.V. All rights reserved.

Small intestinal sulphoxidation of albendazole.

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Villaverde, C; Alvarez, A I; Redondo, P; Voces, J; Del Estal, J L; Prieto, J G

1995-05-01

1. The in vitro sulphoxidation of Albendazole (ABZ) by rat intestinal microsomes has been examined. The results revealed intestinal sulphoxidation of ABZ by intestinal microsomes in a NADPH-dependent enzymatic system. The kinetic constants for sulphoxidase activity were Vmax = 46 pmol/min/mg protein and Michaelis constant Km = 6.8 microM. 2. The possible effect of inducers (Arochlor 1254 and ABZ pretreatment) and inhibitors (erythromycin, methimazole, carbon monoxide and fenbendazole), was also studied. In rat pretreated with Arochlor 1254, Vmax was 52 pmol/min/mg protein, whereas oral administration of ABZ increased the intestinal sulphoxidation of the drug, Vmax being 103 pmol/min/mg protein. 3. Erythromycin did not change the enzymatic bioconversion of ABZ, but methimazole and carbon monoxide inhibited the enzyme activity by approximately 60 and 30% respectively. Fenbendazole (a structural analogue of ABZ) was a competitive inhibitor of the sulphoxidation process, characterized by a Ki or 69 microM. 4. These data demonstrate that the intestinal enzymes contributing to the initial sulphoxidation of ABZ may be similar to the hepatic enzymes involved in the biotransformation process by the P450 and FMO systems, a conclusion that needs to be further established.

Small intestine diverticuli

International Nuclear Information System (INIS)

Pomakov, P.; Risov, A.

1991-01-01

The routine method of contrast matter passage applied to 850 patients with different gastrointestinal diseases proved inefficient to detect any small-intestinal diverticuli. The following modiffications of the method have been tested in order to improve the diagnostic possibilities of the X-ray: study at short intervals, assisted passage, enteroclysm, pharmacodynamic impact, retrograde filling of the ileum by irrigoscopy. Twelve diverticuli of the small-intestinal loops were identified: 5 Meckel's diverticuli, 2 solitary of which one of the therminal ileum, 2 double diverticuli and 1 multiple diverticulosis of the jejunum. The results show that the short interval X-ray examination of the small intestines is the method of choice for identifying local changes in them. The solitary diverticuli are not casuistic scarcity, its occurrence is about 0.5% at purposeful X-ray investigation. The assisted passage method is proposed as a method of choice for detection of the Meckel's diverticulum. 5 figs., 3 tabs. 18 refs

Megacystis microcolon intestinal hypoperistalsis syndrome

Science.gov (United States)

Hiradfar, Mehran; Shojaeian, Reza; Dehghanian, Paria; Hajian, Sara

2013-01-01

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a multisystemic disorder in which impaired intestinal motor activity causes recurrent symptoms of intestinal obstruction in the absence of mechanical occlusion, associated with bladder distention without distal obstruction of the urinary tract. MMIHS and prune belly syndrome may overlap in most of the clinical features and discrimination of these two entities is important because the prognosis, management and consulting with parents are completely different. MMIHS outcome is very poor and in this article we present two neonates with MMIHS that both died in a few days. PMID:23729700

Antibiotic concentrations in intestinal mucosa.

Science.gov (United States)

Malmborg, A S

1985-01-01

The concentrations in the intestinal mucosa after the initial dose of cefoxitin, piperacillin and clindamycin have been studied. The antibiotics were given at the induction of anesthesia as prophylaxis to patients undergoing elective colorectal surgery. The concentrations of the antibiotics in serum and intestinal mucosa taken during the operation were determined by the microbiological agar diffusion method. Therapeutic concentrations in intestinal mucosa were maintained during the major part of the operation period. The mean mucosa/serum concentration ratios were for cefoxitin 0.4, for piperacillin 0.5 and for clindamycin 1.2.

Alterações eletromiográficas e histopatológicas da musculatura de cães naturalmente infectados por Leishmania infantum

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Gisela Cristiane Ferraro

2012-10-01

Full Text Available O objetivo do presente estudo foi avaliar as alterações eletromiográficas e histopatológicas de músculos estriados esqueléticos de cães naturalmente infectados por Leishmania infantum. Foram selecionados 25 cães adultos, sem raça definida, com diagnósticos parasitológico, molecular e sorológico estabelecidos para a infecção. Os músculos avaliados foram: tríceps braquial, extensorcarpo radial, bíceps femoral e gastrocnêmio. Um cão possuía problemas locomotores, com paresia de membros posteriores associada à intensa atrofia muscular. Vinte e três (92% apresentavam algum tipo de alteração muscular, sendo que em 22(88% tais alterações foram identificadas diretamente pela eletromiografia. Mesmo sem sinais clínicos, em dez cães (40% foram evidenciadas alterações eletromiográficas e histopatológicas. Antígenos de Leishmania foram identificados na musculatura de quatro (16% cães. Os resultados eletromiográficos indicaram a ocorrência de polimiosite crônica em 13 (52% cães, presença de músculos com inflamação tanto aguda quanto crônica em quatro (16%, miopatia aguda em dois (8%, e ausência de alterações eletromiográficas em três (12%. As alterações histopatológicas mais frequentemente observadas foram degeneração e necrose de miofibras e presença de infiltrado inflamatório verificadas em 12 (48% cães. Outras alterações, quando comparado com as amostras de cães normais, foram do tamanho de grupos de fibras musculares em 15 (60% e fibrose peri ou endomisial em 14(56% animais. As alterações observadas no presente estudo permitiram concluir que mesmo na ausência de sinais clínicos de comprometimento muscular, a maior parte dos cães infectados por L. infantum apresenta polimiosite crônica.

A high sensitivity heterodyne interferometer as a possible optical readout for the LISA gravitational reference sensor and its application to technology verification

Energy Technology Data Exchange (ETDEWEB)

Gohlke, Martin; Weise, Dennis; Johann, Ulrich; Braxmaier, Claus [EADS Astrium, Claude-Dornier-Strasse, 88039 Friedrichshafen (Germany); Schuldt, Thilo; Peters, Achim, E-mail: martin.gohlke@astrium.eads.ne [Humboldt-Universitaet zu Berlin, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

2009-03-01

The space-based gravitational wave detector LISA (Laser Interferometer Space Antenna) utilizes a high performance position sensor in order to measure the translation and tilt of the free flying proof mass with respect to the optical bench. Depending on the LISA optical bench design, this position sensor must have up to pm/sq rootHz sensitivity for the translation measurement and up to nrad/sq rootHz sensitivity for the tilt measurement. We developed a heterodyne interferometer, combined with differential wavefront sensing, for the tilt measurement. The interferometer design exhibits maximum symmetry where measurement and reference arm have the same frequency and polarization and the same optical path-lengths. The interferometer can be set up free of polarizing optical components preventing possible problems with thermal dependencies not suitable for the space environment. We developed a mechanically highly stable and compact setup which is located in a vacuum chamber. We measured initial noise levels below 10 pm/sq rootHz (longitudinal measurement) for frequencies above 10 mHz and below 20 nrad/sq rootHz (tilt measurement) for frequencies above 1 mHz. This setup can also be used for other applications, for example the measurement of the coefficient of thermal expansion (CTE) of structural materials, such as carbon fiber reinforced plastic (CFRP).

Deciphering the porcine intestinal microRNA transcriptome

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Keller Andreas

2010-04-01

Full Text Available Abstract Background While more than 700 microRNAs (miRNAs are known in human, a comparably low number has been identified in swine. Because of the close phylogenetic distance to humans, pigs serve as a suitable model for studying e.g. intestinal development or disease. Recent studies indicate that miRNAs are key regulators of intestinal development and their aberrant expression leads to intestinal malignancy. Results Here, we present the identification of hundreds of apparently novel miRNAs in the porcine intestine. MiRNAs were first identified by means of deep sequencing followed by miRNA precursor prediction using the miRDeep algorithm as well as searching for conserved miRNAs. Second, the porcine miRNAome along the entire intestine (duodenum, proximal and distal jejunum, ileum, ascending and transverse colon was unraveled using customized miRNA microarrays based on the identified sequences as well as known porcine and human ones. In total, the expression of 332 intestinal miRNAs was discovered, of which 201 represented assumed novel porcine miRNAs. The identified hairpin forming precursors were in part organized in genomic clusters, and most of the precursors were located on chromosomes 3 and 1, respectively. Hierarchical clustering of the expression data revealed subsets of miRNAs that are specific to distinct parts of the intestine pointing to their impact on cellular signaling networks. Conclusions In this study, we have applied a straight forward approach to decipher the porcine intestinal miRNAome for the first time in mammals using a piglet model. The high number of identified novel miRNAs in the porcine intestine points out their crucial role in intestinal function as shown by pathway analysis. On the other hand, the reported miRNAs may share orthologs in other mammals such as human still to be discovered.

BVES Regulates Intestinal Stem Cell Programs and Intestinal Crypt Viability after Radiation

Science.gov (United States)

Reddy, Vishruth K.; Short, Sarah P.; Barrett, Caitlyn W.; Mittal, Mukul K.; Keating, Cody E.; Thompson, Joshua J.; Harris, Elizabeth I.; Revetta, Frank; Bader, David M.; Brand, Thomas; Washington, M. Kay; Williams, Christopher S.

2016-01-01

Blood Vessel Epicardial Substance (BVES/Popdc1) is a junctional-associated transmembrane protein that is underexpressed in a number of malignancies and regulates epithelial-to-mesenchymal transition. We previously identified a role for BVES in regulation of the Wnt pathway, a modulator of intestinal stem cell programs, but its role in small intestinal (SI) biology remains unexplored. We hypothesized that BVES influences intestinal stem cell programs and is critical to SI homeostasis after radiation injury. At baseline, Bves−/− mice demonstrated increased crypt height, as well as elevated proliferation and expression of the stem cell marker Lgr5 compared to wildtype (WT) mice. Intercross with Lgr5-EGFP reporter mice confirmed expansion of the stem cell compartment in Bves−/− mice. To examine stem cell function after BVES deletion, we employed ex vivo 3D-enteroid cultures. Bves−/− enteroids demonstrated increased stemness compared to WT, when examining parameters such as plating efficiency, stem spheroid formation, and retention of peripheral cystic structures. Furthermore, we observed increased proliferation, expression of crypt-base columnar “CBC” and “+4” stem cell markers, amplified Wnt signaling, and responsiveness to Wnt activation in the Bves−/− enteroids. Bves expression was downregulated after radiation in WT mice. Moreover, after radiation, Bves−/− mice demonstrated significantly greater small intestinal crypt viability, proliferation, and amplified Wnt signaling in comparison to WT mice. Bves−/− mice also demonstrated elevations in Lgr5 and Ascl2 expression, and putative damage-responsive stem cell populations marked by Bmi1 and TERT. Therefore, BVES is a key regulator of intestinal stem cell programs and mucosal homeostasis. PMID:26891025

Evaluation value of intestinal flora detection for intestinal mucosal inflammation and immune response in patients with ulcerative colitis

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Yan Zou

2017-09-01

Full Text Available Objective: To study the evaluation value of intestinal flora detection for intestinal mucosal inflammatory response and immune response in patients with ulcerative colitis. Methods: The patients who were diagnosed with ulcerative colitis in Zigong Fifth People’s Hospital between March 2015 and February 2017 were selected as the UC group, and those who were diagnosed with colonic polyps were selected as the control group. Fresh excreta were collected to detect the number of intestinal flora, and the diseased intestinal mucosa tissue was collected to detect the expression of inflammatory response molecules and immune cell transcription factors. Results: enterococcus contents in intestinal tract and TLR4, NF-kB, TNF-α, HMGB-1, T-bet and RORC mRNA expression levels in intestinal mucosa of UC group were significantly higher than those of control group while bifidobacteria contents in intestinal tract and SOCS2, SOCS3, Foxp3 and GATA-3 mRNA expression levels were significantly lower than those of control group; TLR4, NF-kB, TNF-α, HMGB-1, T-bet and RORC mRNA expression levels in intestinal mucosa of UC patients with grade II and grade III flora disturbance were significantly higher than those of UC patients with normal flora and grade I flora disturbance while SOCS2, SOCS3, Foxp3 and GATA-3 mRNA expression levels were significantly lower than those of UC patients with normal flora and grade I flora disturbance; TLR4, NF-kB, TNF-α, HMGB-1, T-bet and RORC mRNA expression levels in intestinal mucosa of UC patients with grade III flora disturbance were significantly higher than those of UC patients with grade II flora disturbance while SOCS2, SOCS3, Foxp3 and GATA-3 mRNA expression levels were significantly lower than those of UC patients with grade II flora disturbance. Conclusion: The intestinal flora disturbance in patients with ulcerative colitis can result in inflammatory response activation and immune response disorder.

Intestinal perfusion in the study of intestinal absorption

International Nuclear Information System (INIS)

Baker, S.J.

1976-01-01

Several techniques for studying absorption by means of intestinal perfusion have been developed. While the principle is simple, the practice is complicated by absorption of the solvent and by excretion of fluid into the lumen. To improve reliability a ''marker'' is incorporated into the system; it should behave as nearly as possible like the nutrient of interest, except that it should be unabsorbable. A great many markers, including several labelled with radionuclides, have been developed for use with numerous nutrients, and perfusion methods using double or triple tubes or occlusive balloons have been tested. The perfusion technique is too complicated for routine diagnostic use, but it offers at present the only possibility of studying the function of defined sections of the small intestine in the intact human. (author)

The jagged-2/notch-1/hes-1 pathway is involved in intestinal epithelium regeneration after intestinal ischemia-reperfusion injury.

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Guoqing Chen

Full Text Available Notch signaling plays a critical role in the maintenance of intestinal crypt epithelial cell proliferation. The aim of this study was to investigate the role of Notch signaling in the proliferation and regeneration of intestinal epithelium after intestinal ischemia reperfusion (I/R injury.Male Sprague-Dawley rats were subjected to sham operation or I/R by occlusion of the superior mesenteric artery (SMA for 20 min. Intestinal tissue samples were collected at 0, 1, 2, 4, and 6 h after reperfusion. Proliferation of the intestinal epithelium was evaluated by immunohistochemical staining of proliferating nuclear antigen (PCNA. The mRNA and protein expression levels of Notch signaling components were examined using Real-time PCR and Western blot analyses. Immunofluorescence was also performed to detect the expression and location of Jagged-2, cleaved Notch-1, and Hes-1 in the intestine. Finally, the γ-secretase inhibitor DAPT and the siRNA for Jagged-2 and Hes-1 were applied to investigate the functional role of Notch signaling in the proliferation of intestinal epithelial cells in an in vitro IEC-6 culture system.I/R injury caused increased intestinal crypt epithelial cell proliferation and increased mRNA and protein expression of Jagged-2, Notch-1, and Hes-1. The immunofluorescence results further confirmed increased protein expression of Jagged-2, cleaved Notch-1, and Hes-1 in the intestinal crypts. The inhibition of Notch signaling with DAPT and the suppression of Jagged-2 and Hes-1 expression using siRNA both significantly inhibited the proliferation of IEC-6 cells.The Jagged-2/Notch-1/Hes-1 signaling pathway is involved in intestinal epithelium regeneration early after I/R injury by increasing crypt epithelial cell proliferation.

Alternative Functional In Vitro Models of Human Intestinal Epithelia

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Amanda L Kauffman

2013-07-01

Full Text Available Physiologically relevant sources of absorptive intestinal epithelial cells are crucial for human drug transport studies. Human adenocarcinoma-derived intestinal cell lines, such as Caco-2, offer conveniences of easy culture maintenance and scalability, but do not fully recapitulate in vivo intestinal phenotypes. Additional sources of renewable physiologically relevant human intestinal cells would provide a much needed tool for drug discovery and intestinal physiology. We sought to evaluate and compare two alternative sources of human intestinal cells, commercially available primary human intestinal epithelial cells (hInEpCs and induced pluripotent stem cell (iPSC-derived intestinal cells to Caco-2, for use in in vitro transwell monolayer intestinal transport assays. To achieve this for iPSC-derived cells, our previously described 3-dimensional intestinal organogenesis method was adapted to transwell differentiation. Intestinal cells were assessed by marker expression through immunocytochemical and mRNA expression analyses, monolayer integrity through Transepithelial Electrical Resistance (TEER measurements and molecule permeability, and functionality by taking advantage the well-characterized intestinal transport mechanisms. In most cases, marker expression for primary hInEpCs and iPSC-derived cells appeared to be as good as or better than Caco-2. Furthermore, transwell monolayers exhibited high TEER with low permeability. Primary hInEpCs showed molecule efflux indicative of P-glycoprotein transport. Primary hInEpCs and iPSC-derived cells also showed neonatal Fc receptor-dependent binding of immunoglobulin G variants. Primary hInEpCs and iPSC-derived intestinal cells exhibit expected marker expression and demonstrate basic functional monolayer formation, similar to or better than Caco-2. These cells could offer an alternative source of human intestinal cells for understanding normal intestinal epithelial physiology and drug transport.

An intestinal Trojan horse for gene delivery.

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Peng, Haisheng; Wang, Chao; Xu, Xiaoyang; Yu, Chenxu; Wang, Qun

2015-03-14

The intestinal epithelium forms an essential element of the mucosal barrier and plays a critical role in the pathophysiological response to different enteric disorders and diseases. As a major enteric dysfunction of the intestinal tract, inflammatory bowel disease is a genetic disease which results from the inappropriate and exaggerated mucosal immune response to the normal constituents in the mucosal microbiota environment. An intestine targeted drug delivery system has unique advantages in the treatment of inflammatory bowel disease. As a new concept in drug delivery, the Trojan horse system with the synergy of nanotechnology and host cells can achieve better therapeutic efficacy in specific diseases. Here, we demonstrated the feasibility of encapsulating DNA-functionalized gold nanoparticles into primary isolated intestinal stem cells to form an intestinal Trojan horse for gene regulation therapy of inflammatory bowel disease. This proof-of-concept intestinal Trojan horse will have a wide variety of applications in the diagnosis and therapy of enteric disorders and diseases.

Radioimmunoassay studies of intestinal calcium-binding protein in the pig. 2. The distribution of intestinal CaBP in pig tissues

International Nuclear Information System (INIS)

Arnold, B.M.; Kuttner, M.; Willis, D.M.; Hitchman, A.J.W.; Harrison, J.E.; Murray, T.M.

1975-01-01

Using a specific radioimmunoassay for porcine intestinal calcium-binding protein (CaBP), we have measured the concentration of CaBP in the various tissues and organs of normal pigs. Intestinal CaBP was present in highest concentration in the upper small intestine, with lower concentrations in the distal small intestine. Intestinal CaBP was also found, in lower concentrations, in kidney, liver, thyroid, pancreas, and blood. In all other tissues, including parathyroid, bone, skeletal muscle, and brain, CaBP immunoreactivity was undetectable or less than in blood. The elution profile of calcium-binding activity and immunoreactivity from gel filtration analysis of kidney and parathyroid extracts suggest that the calcium-binding protein in the parathyroid gland, and the major calcium-binding protein(s) in the kidney, are chemically and immunochemically different from intestinal CaBP. (author)

Radioimmunoassay studies of intestinal calcium-binding protein in the pig. II. The distribution of intestinal CaBP in pig tissues

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Arnold, B M; Kuttner, M; Willis, D M; Hitchman, A J.W.; Harrison, J E; Murray, T M [Toronto Univ., Ontario (Canada). Dept. of Medicine

1975-12-01

Using a specific radioimmunoassay for porcine intestinal calcium-binding protein (CaBP), we have measured the concentration of CaBP in the various tissues and organs of normal pigs. Intestinal CaBP was present in highest concentration in the upper small intestine, with lower concentrations in the distal small intestine. Intestinal CaBP was also found, in lower concentrations, in kidney, liver, thyroid, pancreas, and blood. In all other tissues, including parathyroid, bone, skeletal muscle, and brain, CaBP immunoreactivity was undetectable or less than in blood. The elution profile of calcium-binding activity and immunoreactivity from gel filtration analysis of kidney and parathyroid extracts suggest that the calcium-binding protein in the parathyroid gland, and the major calcium-binding protein(s) in the kidney, are chemically and immunochemically different from intestinal CaBP.

Parenteral nutrition in intestinal failure

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Kurkchubasche AG

2015-01-01

Full Text Available Arlet G Kurkchubasche,1 Thomas J Herron,2 Marion F Winkler31Department of Surgery and Pediatrics, 2Department of Surgery, Alpert Medical School of Brown University, 3Department of Surgery/Nutritional Support Service, Rhode Island Hospital, Providence, RI, USAAbstract: Intestinal failure is a consequence of extensive surgical resection resulting in anatomic loss and/or functional impairment in motility or absorptive capacity. The condition is clinically characterized by the inability to maintain fluid, energy, protein, electrolyte, or micronutrient balance when on a conventionally accepted, normal diet. Parenteral nutrition (PN is the cornerstone of management until intestinal adaptation returns the patient to a PN-independent state. Intestinal length, residual anatomic segments and motility determine the need for and duration of parenteral support. The goals of therapy are to provide sufficient nutrients to enable normal growth and development in children, and support a healthy functional status in adults. This review addresses indications for PN, the formulation of the PN solution, patient monitoring, and considerations for prevention of PN-associated complications. With the ultimate goal of achieving enteral autonomy, the important role of diet, pharmacologic interventions, and surgery is discussed.Keywords: intestinal failure, short-bowel syndrome, parenteral nutrition, home nutrition support, intestinal rehabilitation

Transcriptome Analysis of Three Sheep Intestinal Regions reveals Key Pathways and Hub Regulatory Genes of Large Intestinal Lipid Metabolism.

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Chao, Tianle; Wang, Guizhi; Ji, Zhibin; Liu, Zhaohua; Hou, Lei; Wang, Jin; Wang, Jianmin

2017-07-13

The large intestine, also known as the hindgut, is an important part of the animal digestive system. Recent studies on digestive system development in ruminants have focused on the rumen and the small intestine, but the molecular mechanisms underlying sheep large intestine metabolism remain poorly understood. To identify genes related to intestinal metabolism and to reveal molecular regulation mechanisms, we sequenced and compared the transcriptomes of mucosal epithelial tissues among the cecum, proximal colon and duodenum. A total of 4,221 transcripts from 3,254 genes were identified as differentially expressed transcripts. Between the large intestine and duodenum, differentially expressed transcripts were found to be significantly enriched in 6 metabolism-related pathways, among which PPAR signaling was identified as a key pathway. Three genes, CPT1A, LPL and PCK1, were identified as higher expression hub genes in the large intestine. Between the cecum and colon, differentially expressed transcripts were significantly enriched in 5 lipid metabolism related pathways, and CEPT1 and MBOAT1 were identified as hub genes. This study provides important information regarding the molecular mechanisms of intestinal metabolism in sheep and may provide a basis for further study.

Effects of Digested Onion Extracts on Intestinal Gene Expression: An Interspecies Comparison Using Different Intestine Models.

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Nicole J W de Wit

Full Text Available Human intestinal tissue samples are barely accessible to study potential health benefits of nutritional compounds. Numbers of animals used in animal trials, however, need to be minimalized. Therefore, we explored the applicability of in vitro (human Caco-2 cells and ex vivo intestine models (rat precision cut intestine slices and the pig in-situ small intestinal segment perfusion (SISP technique to study the effect of food compounds. In vitro digested yellow (YOd and white onion extracts (WOd were used as model food compounds and transcriptomics was applied to obtain more insight into which extent mode of actions depend on the model. The three intestine models shared 9,140 genes which were used to compare the responses to digested onions between the models. Unsupervised clustering analysis showed that genes up- or down-regulated by WOd in human Caco-2 cells and rat intestine slices were similarly regulated by YOd, indicating comparable modes of action for the two onion species. Highly variable responses to onion were found in the pig SISP model. By focussing only on genes with significant differential expression, in combination with a fold change > 1.5, 15 genes showed similar onion-induced expression in human Caco-2 cells and rat intestine slices and 2 overlapping genes were found between the human Caco-2 and pig SISP model. Pathway analyses revealed that mainly processes related to oxidative stress, and especially the Keap1-Nrf2 pathway, were affected by onions in all three models. Our data fit with previous in vivo studies showing that the beneficial effects of onions are mostly linked to their antioxidant properties. Taken together, our data indicate that each of the in vitro and ex vivo intestine models used in this study, taking into account their limitations, can be used to determine modes of action of nutritional compounds and can thereby reduce the number of animals used in conventional nutritional intervention studies.

Interactions between the intestinal microbiota and innate lymphoid cells

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Chen, Vincent L; Kasper, Dennis L

2014-01-01

The mammalian intestine must manage to contain 100 trillion intestinal bacteria without inducing inappropriate immune responses to these microorganisms. The effects of the immune system on intestinal microorganisms are numerous and well-characterized, and recent research has determined that the microbiota influences the intestinal immune system as well. In this review, we first discuss the intestinal immune system and its role in containing and maintaining tolerance to commensal organisms. We next introduce a category of immune cells, the innate lymphoid cells, and describe their classification and function in intestinal immunology. Finally, we discuss the effects of the intestinal microbiota on innate lymphoid cells. PMID:24418741

ACUTE INTESTINAL INFECTIONS: THERAPEUTICAL TACTICS IN CHILDREN

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A.N. Surkov

2011-01-01

Full Text Available Acute intestinal infections are quite common among children. Their clinical presentations include intoxication syndrome (drowsiness, low appetite, fever etc, infectious toxic syndrome (toxicosis with exicosis, neurotoxicosi, hypovolemic or infectious-toxic shockand diarrhea syndrome. Sometimes intestinal infections can be quite severe and even lethal. However disease duration and outcome depend on timelines and adequacy of prescribed treatment. Main guidelines of intestinal infections treatment include probiotics. That is why the right choice of probiotics is important for a pediatrician. The article contains basic information upon etiopathogenesis, classification, diagnostic criteria and acute pediatric intestinal infections treatment guidelines.Key words: acute intestinal infections, etiopathogenesis, diagnostic criteria, treatment, probiotics, children. (Voprosy sovremennoi pediatrii — Current Pediatrics. — 2011; 10 (6: 141–147

Hippo signalling directs intestinal fate

DEFF Research Database (Denmark)

le Bouteiller, Marie Catherine M; Jensen, Kim Bak

2015-01-01

Hippo signalling has been associated with many important tissue functions including the regulation of organ size. In the intestinal epithelium differing functions have been proposed for the effectors of Hippo signalling, YAP and TAZ1. These are now shown to have a dual role in the intestinal...

Intestinal leiomyoma

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... most often found when a person has an upper gastrointestinal (GI) endoscopy or colonoscopy for another reason. Rarely, these tumors can cause bleeding, blockage or rupture of the intestines If this ...

Functional characterization of folic acid transport in the intestine of the laying hen using the everted intestinal sac model.

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Tactacan, G B; Rodriguez-Lecompte, J C; Karmin, O; House, J D

2011-01-01

Absorption at the level of the intestine is likely a primary regulatory mechanism for the deposition of dietary supplemented folic acid into the chicken egg. Therefore, factors affecting the intestinal transport of folic acid in the laying hen may influence the level of egg folate concentrations. To this end, a series of experiments using intestinal everted sacs were conducted to characterize intestinal folic acid absorption processes in laying hens. Effects of naturally occurring folate derivatives (5-methyl and 10-formyltetrahydrofolate) as well as heme on folic acid absorption were also investigated. Folic acid absorption was measured based on the rate of uptake of (3)H-labeled folic acid in the everted sac from various segments of the small and large intestines. Folic acid concentration, incubation length, and pH condition were optimized before the performance of uptake experiments. The distribution profile of folic acid transport along the intestine was highest in the upper half of the small intestine. Maximum uptake rate (nmol·100 g tissue(-1)·min(-1)) was observed in the duodenum (20.6 ± 1.9) and jejunum (22.3 ± 2.0) and decreased significantly in the ileum (15.3 ± 1.1) and cecum (9.3 ± 0.9). Transport increased proportionately (P methyl and 10-formyltetrahydrofolate as well as heme impeded folic acid uptake, reducing intestinal folic acid absorption when added at concentrations ranging from 0 to 100 µM. Overall, these data indicated the presence of a folic acid transport system in the entire intestine of the laying hen. Uptake of folic acid in the cecum raises the likelihood of absorption of bacterial-derived folate.

Regulation of intestinal homeostasis by innate immune cells.

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Kayama, Hisako; Nishimura, Junichi; Takeda, Kiyoshi

2013-12-01

The intestinal immune system has an ability to distinguish between the microbiota and pathogenic bacteria, and then activate pro-inflammatory pathways against pathogens for host defense while remaining unresponsive to the microbiota and dietary antigens. In the intestine, abnormal activation of innate immunity causes development of several inflammatory disorders such as inflammatory bowel diseases (IBD). Thus, activity of innate immunity is finely regulated in the intestine. To date, multiple innate immune cells have been shown to maintain gut homeostasis by preventing inadequate adaptive immune responses in the murine intestine. Additionally, several innate immune subsets, which promote Th1 and Th17 responses and are implicated in the pathogenesis of IBD, have recently been identified in the human intestinal mucosa. The demonstration of both murine and human intestinal innate immune subsets contributing to regulation of adaptive immunity emphasizes the conserved innate immune functions across species and might promote development of the intestinal innate immunity-based clinical therapy.

A new approach to predict human intestinal absorption using porcine intestinal tissue and biorelevant matrices

NARCIS (Netherlands)

Westerhout, J.; Steeg, E. van de; Grossouw, D.; Zeijdner, E.E.; Krul, C.A.M.; Verwei, M.; Wortelboer, H.M.

2014-01-01

A reliable prediction of the oral bioavailability in humans is crucial and of high interest for pharmaceutical and food industry. The predictive value of currently used in silico methods, in vitro cell lines, ex vivo intestinal tissue and/or in vivo animal studies for human intestinal absorption,

Regional specialization within the intestinal immune system

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Mowat, Allan M.; Agace, William Winston

2014-01-01

The intestine represents the largest compartment of the immune system. It is continually exposed to antigens and immunomodulatory agents from the diet and the commensal microbiota, and it is the port of entry for many clinically important pathogens. Intestinal immune processes are also increasingly...... implicated in controlling disease development elsewhere in the body. In this Review, we detail the anatomical and physiological distinctions that are observed in the small and large intestines, and we suggest how these may account for the diversity in the immune apparatus that is seen throughout...... the intestine. We describe how the distribution of innate, adaptive and innate-like immune cells varies in different segments of the intestine and discuss the environmental factors that may influence this. Finally, we consider the implications of regional immune specialization for inflammatory disease...

Intestinal metaplasia induced by x-irradiation in rat

International Nuclear Information System (INIS)

Watanabe, Hiromitsu; Terada, Yoritaka; Fujii, Isao; Yamamoto, Yukiko; Takizawa, Shoichi

1978-01-01

Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation. (Ueda, J.)

Intestinal metaplasia induced by x-irradiation in rat

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Watanabe, H; Terada, Y; Fujii, I; Yamamoto, Y; Takizawa, S [Hiroshima Univ. (Japan). Research Inst. for Nuclear Medicine and Biology

1978-04-01

Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation.

Intestinal sclerosis with pseudo-obstruction in three dogs.

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Moore, R; Carpenter, J

1984-04-01

Intestinal sclerosis causing chronic intestinal pseudo-obstruction was diagnosed in 3 dogs. The pseudo-obstruction was characterized by vomiting and weight loss of 2 weeks' to 3 months' duration. A patent intestinal lumen was determined by contrast radiography and verified at surgery. Intestinal biopsy revealed diffuse atrophy, fibrosis, and mononuclear cell infiltration of the tunica muscularis. Each dog was euthanatized because of a progressive, deteriorating clinical course.

Fluorescent labelling of intestinal epithelial cells reveals independent long-lived intestinal stem cells in a crypt

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Horita, Nobukatsu [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan); Tsuchiya, Kiichiro, E-mail: kii.gast@tmd.ac.jp [Department of Advanced Therapeutics for Gastrointestinal Diseases, Graduate School, Tokyo Medical and Dental University (Japan); Hayashi, Ryohei [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan); Department of Gastroenterology and Metabolism, Hiroshima University (Japan); Fukushima, Keita; Hibiya, Shuji; Fukuda, Masayoshi; Kano, Yoshihito; Mizutani, Tomohiro; Nemoto, Yasuhiro; Yui, Shiro [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan); Okamoto, Ryuichi; Nakamura, Tetsuya [Department of Advanced Therapeutics for Gastrointestinal Diseases, Graduate School, Tokyo Medical and Dental University (Japan); Watanabe, Mamoru [Department of Gastroenterology and Hepatology, Graduate School, Tokyo Medical and Dental University (Japan)

2014-11-28

Highlights: • Lentivirus mixed with Matrigel enables direct infection of intestinal organoids. • Our original approach allows the marking of a single stem cell in a crypt. • Time-lapse imaging shows the dynamics of a single stem cell. • Our lentivirus transgene system demonstrates plural long-lived stem cells in a crypt. - Abstract: Background and aims: The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualised in the same colour. Methods: Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence. Results: We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1 year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids. Conclusions: The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus.

Fluorescent labelling of intestinal epithelial cells reveals independent long-lived intestinal stem cells in a crypt

International Nuclear Information System (INIS)

Horita, Nobukatsu; Tsuchiya, Kiichiro; Hayashi, Ryohei; Fukushima, Keita; Hibiya, Shuji; Fukuda, Masayoshi; Kano, Yoshihito; Mizutani, Tomohiro; Nemoto, Yasuhiro; Yui, Shiro; Okamoto, Ryuichi; Nakamura, Tetsuya; Watanabe, Mamoru

2014-01-01

Highlights: • Lentivirus mixed with Matrigel enables direct infection of intestinal organoids. • Our original approach allows the marking of a single stem cell in a crypt. • Time-lapse imaging shows the dynamics of a single stem cell. • Our lentivirus transgene system demonstrates plural long-lived stem cells in a crypt. - Abstract: Background and aims: The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualised in the same colour. Methods: Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence. Results: We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1 year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids. Conclusions: The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus

Immunization with intestinal microbiota-derived Staphylococcus aureus and Escherichia coli reduces bacteria-specific recolonization of the intestinal tract.

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Garfias-López, Julio Adrián; Castro-Escarpuli, Graciela; Cárdenas, Pedro E; Moreno-Altamirano, María Maximina Bertha; Padierna-Olivos, Juan; Sánchez-García, F Javier

2018-04-01

A wide array of microorganisms colonizes distinctive anatomical regions of animals, being the intestine the one that harbors the most abundant and complex microbiota. Phylogenetic analyses indicate that it is composed mainly of bacteria, and that Bacterioidetes and Firmicutes are the most represented phyla (>90% of the total eubacteria) in mice and humans. Intestinal microbiota plays an important role in host physiology, contributing to digestion, epithelial cells metabolism, stimulation of intestinal immune responses, and protection against intestinal pathogens. Changes in its composition may affect intestinal homeostasis, a condition known as dysbiosis, which may lead to non-specific inflammation and disease. The aim of this work was to analyze the effect that a bacteria-specific systemic immune response would have on the intestinal re-colonization by that particular bacterium. Bacteria were isolated and identified from the feces of Balb/c mice, bacterial cell-free extracts were used to immunize the same mice from which bacteria came from. Concurrently with immunization, mice were subjected to a previously described antibiotic-based protocol to eliminate most of their intestinal bacteria. Serum IgG and feces IgA, specific for the immunizing bacteria were determined. After antibiotic treatment was suspended, specific bacteria were orally administered, in an attempt to specifically re-colonize the intestine. Results showed that parenteral immunization with gut-derived bacteria elicited the production of both anti-bacterial IgG and IgA, and that immunization reduces bacteria specific recolonization of the gut. These findings support the idea that the systemic immune response may, at least in part, determine the bacterial composition of the gut. Copyright © 2018. Published by Elsevier B.V.

The mucosal firewalls against commensal intestinal microbes.

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Macpherson, Andrew J; Slack, Emma; Geuking, Markus B; McCoy, Kathy D

2009-07-01

Mammals coexist with an extremely dense microbiota in the lower intestine. Despite the constant challenge of small numbers of microbes penetrating the intestinal surface epithelium, it is very unusual for these organisms to cause disease. In this review article, we present the different mucosal firewalls that contain and allow mutualism with the intestinal microbiota.

The mechanism of circulatory disturbances in the small intestinal wall and their role in the development of intestinal syndrome

International Nuclear Information System (INIS)

Kudryavtsev, V.D.; Sushkevich, L.N.

1980-01-01

The mechanism of vascular disorders in the wall of the small intestine, the possibility of correcting them and their significance in the development of the intestinal syndrome were analysed. The experiments in which Wistar rats were irradiated with 10 Gy yielded information on the blood flow in the small intestine, on the number of regenerating crypts, on the blood plasma volume and on arterial blood pressure. The data obtained justify to speak of an important influence of disturbances in general hemodynamics on the microcirculation in the entire organ. Reaction that fail to take place or paradoxic changes in the blood flow of tissue after injection of vasoactive substances also illustrate the significance of direct intestinal vascular damage for adversely affecting compensatory adaptation mechanisms. Markedly disturbed blood supply to the tissue and the resultant deterioration of tissue trophism at the level of an intestinal syndrome not only intensify radiogenic destructive processes in epitheliocytes, but also prevent to a certain extent the regeneration of mucous membrane of the small intestine. The possibility of achieving partial restoration of blood vessel speed in the small intestine of irradiated rats is shown if the loss of intravascular fluid is parenterally replaced with Ringer's or hemodilution solution. (author)

Cytokine Tuning of Intestinal Epithelial Function

Directory of Open Access Journals (Sweden)

Caroline Andrews

2018-06-01

Full Text Available The intestine serves as both our largest single barrier to the external environment and the host of more immune cells than any other location in our bodies. Separating these potential combatants is a single layer of dynamic epithelium composed of heterogeneous epithelial subtypes, each uniquely adapted to carry out a subset of the intestine’s diverse functions. In addition to its obvious role in digestion, the intestinal epithelium is responsible for a wide array of critical tasks, including maintaining barrier integrity, preventing invasion by microbial commensals and pathogens, and modulating the intestinal immune system. Communication between these epithelial cells and resident immune cells is crucial for maintaining homeostasis and coordinating appropriate responses to disease and can occur through cell-to-cell contact or by the release or recognition of soluble mediators. The objective of this review is to highlight recent literature illuminating how cytokines and chemokines, both those made by and acting on the intestinal epithelium, orchestrate many of the diverse functions of the intestinal epithelium and its interactions with immune cells in health and disease. Areas of focus include cytokine control of intestinal epithelial proliferation, cell death, and barrier permeability. In addition, the modulation of epithelial-derived cytokines and chemokines by factors such as interactions with stromal and immune cells, pathogen and commensal exposure, and diet will be discussed.

Lynch syndrome-related small intestinal adenocarcinomas.

Science.gov (United States)

Jun, Sun-Young; Lee, Eui-Jin; Kim, Mi-Ju; Chun, Sung Min; Bae, Young Kyung; Hong, Soon Uk; Choi, Jene; Kim, Joon Mee; Jang, Kee-Taek; Kim, Jung Yeon; Kim, Gwang Il; Jung, Soo Jin; Yoon, Ghilsuk; Hong, Seung-Mo

2017-03-28

Lynch syndrome is an autosomal-dominant disorder caused by defective DNA mismatch repair (MMR) genes and is associated with increased risk of malignancies in multiple organs. Small-intestinal adenocarcinomas are common initial manifestations of Lynch syndrome. To define the incidence and characteristics of Lynch syndrome-related small-intestinal adenocarcinomas, meticulous familial and clinical histories were obtained from 195 patients with small-intestinal adenocarcinoma, and MMR protein immunohistochemistry, microsatellite instability, MLH1 methylation, and germline mutational analyses were performed. Lynch syndrome was confirmed in eight patients (4%), all of whom had synchronous/metachronous malignancies without noticeable familial histories. Small-intestinal adenocarcinomas were the first clinical manifestation in 37% (3/8) of Lynch syndrome patients, and second malignancies developed within 5 years in 63% (5/8). The patients with accompanying Lynch syndrome were younger (≤50 years; P=0.04) and more likely to have mucinous adenocarcinomas (P=0.003), and tended to survive longer (P=0.11) than those with sporadic cases. A meticulous patient history taking, MMR protein immunolabeling, and germline MMR gene mutational analysis are important for the diagnosis of Lynch syndrome-related small-intestinal adenocarcinomas. Identifying Lynch syndrome in patients with small-intestinal adenocarcinoma can be beneficial for the early detection and treatment of additional Lynch syndrome-related cancers, especially in patients who are young or have mucinous adenocarcinomas.

A comparative study on the metabolism of Epimedium koreanum Nakai-prenylated flavonoids in rats by an intestinal enzyme (lactase phlorizin hydrolase) and intestinal flora.

Science.gov (United States)

Zhou, Jing; Chen, Yan; Wang, Ying; Gao, Xia; Qu, Ding; Liu, Congyan

2013-12-24

The aim of this study was to compare the significance of the intestinal hydrolysis of prenylated flavonoids in Herba Epimedii by an intestinal enzyme and flora. Flavonoids were incubated at 37 °C with rat intestinal enzyme and intestinal flora. HPLC-UV was used to calculate the metabolic rates of the parent drug in the incubation and LC/MS/MS was used to determine the chemical structures of metabolites generated by different flavonoid glycosides. Rates of flavonoid metabolism by rat intestinal enzyme were quicker than those of intestinal flora. The sequence of intestinal flora metabolic rates was icariin>epimedin B>epimedin A>epimedin C>baohuoside I, whereas the order of intestinal enzyme metabolic rates was icariin>epimedin A>epimedin C>epimedin B>baohuoside I. Meanwhile, the LC/MS/MS graphs showed that icariin produced three products, epimedin A/B/C had four and baohuoside I yielded one product in incubations of both intestinal enzyme and flora, which were more than the results of HPLC-UV due to the fact LC/MS/MS has lower detectability and higher sensitivity. Moreover, the outcomes indicated that the rate of metabolization of flavonoids by intestinal enzyme were faster than those of intestinal flora, which was consistent with the HPLC-UV results. In conclusion, the metabolic pathways of the same components by intestinal flora and enzyme were the same. What's more, an intestinal enzyme such as lactase phlorizin hydrolase exhibited a more significant metabolic role in prenylated flavonoids of Herba Epimedi compared with intestinal flora.

Plasma intestinal fatty acid binding protein (I-FABP) concentrations increase following intestinal ischemia in pigs

NARCIS (Netherlands)

Niewold, T.A.; Meinen, M.; Meulen, van der J.

2004-01-01

Intestinal fatty acid binding protein (I-FABP) is an intracellular epithelial protein in the intestinal mucosa of many animals. IFABP appears in the circulation following epithelial damage, and in humans, is proven to be a parameter for damage to the mucosa. In this paper, an ELISA test designed for

[Primary intestinal lymphangiectasia (Waldmann's disease)].

Science.gov (United States)

Vignes, S; Bellanger, J

2017-08-31

Primary intestinal lymphangiectasia (PIL), Waldmann's disease, is a rare disorder of unknown etiology characterized by dilated intestinal lacteals leading to lymph leakage into the small-bowel lumen and responsible for protein-losing enteropathy leading to lymphopenia, hypoalbuminemia and hypogammaglobulinemia. PIL is generally diagnosed before 3 years of age but may be diagnosed in older patients. The main symptom is bilateral lower limb edema. Edema may be moderate to severe including pleural effusion, pericarditis or ascites. Protein-losing enteropathy is confirmed by the elevated 24-h stool α1-antitrypsin clearance and diagnosis by endoscopic observation of intestinal lymphangiectasia with the corresponding histology of biopsies. Videocapsule endoscopy may be useful when endoscopic findings are not contributive. Several B-cell lymphomas of the gastrointestinal tract or with extra-intestinal localizations were reported in PIL patients. A long-term strictly low-fat diet associated with medium-chain triglyceride and liposoluble vitamin supplementation is the cornerstone of PIL medical management. Octreotide, a somatostatin analog, have been proposed with an inconsistent efficacy in association with diet. Surgical small-bowel resection is useful in the rare cases with segmental and localized intestinal lymphangiectasia. A prolonged clinical and biological follow-up is recommended. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Intestinal circulation during inhalation anesthesia

International Nuclear Information System (INIS)

Tverskoy, M.; Gelman, S.; Fowler, K.C.; Bradley, E.L.

1985-01-01

This study was designed to evaluate the influence of inhalational agents on the intestinal circulation in an isolated loop preparation. Sixty dogs were studied, using three intestinal segments from each dog. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mmHg. A mixture of 86 Rb and 9-microns spheres labeled with 141 Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A very strong and significant correlation was found between rubidium clearance and microsphere entrapment (r = 0.97, P less than 0.0001). Nitrous oxide anesthesia was accompanied by a higher vascular resistance (VR), lower flow (F), rubidium clearance (Cl-Rb), and microspheres entrapment (Cl-Sph) than pentobarbital anesthesia, indicating that the vascular bed in the intestinal segment was constricted and flow (total and nutritive) decreased. Halothane, enflurane, and isoflurane anesthesia were accompanied by a much lower arteriovenous oxygen content difference (AVDO 2 ) and oxygen uptake than pentobarbital or nitrous oxide. Compared with pentobarbital, enflurane anesthesia was not accompanied by marked differences in VR, F, Cl-Rb, and Cl-Sph; halothane at 2 MAC decreased VR and increased F and Cl-Rb while isoflurane increased VR and decreased F. alpha-Adrenoceptor blockade with phentolamine (1 mg . kg-1) abolished isoflurane-induced vasoconstriction, suggesting that the increase in VR was mediated via circulating catecholamines

Intestinal mucus accumulation in a child with acutemyeloblastic leukemia

Directory of Open Access Journals (Sweden)

Namık Özbek

2009-12-01

Full Text Available Intestinal mucus accumulation is a very rare situation observed in some solid tumors, intestinal inflammation, mucosal hyperplasia, elevated intestinal pressure, and various other diseases. However, it has never been described in acute myeloblastic leukemia. The pathogenesis of intestinal mucus accumulation is still not clear. Here, we report a 14-year-old girl with acute myeloblastic leukemia and febrile neutropenia in addition to typhlitis. She was also immobilized due to joint contractures of the lower extremities and had intestinal mucus accumulation, which was, at first, misdiagnosed as intestinal parasitosis. We speculate that typhlitis, immobilization and decreased intestinal motility due to usage of antiemetic drugs might have been the potential etiologic factors in this case. However, its impact on prognosis of the primary disease is unknown.

Disrupted intestinal microbiota and intestinal inflammation in children with cystic fibrosis and its restoration with Lactobacillus GG: a randomised clinical trial.

Directory of Open Access Journals (Sweden)

Eugenia Bruzzese

Full Text Available Intestinal inflammation is a hallmark of cystic fibrosis (CF. Administration of probiotics can reduce intestinal inflammation and the incidence of pulmonary exacerbations. We investigated the composition of intestinal microbiota in children with CF and analyzed its relationship with intestinal inflammation. We also investigated the microflora structure before and after Lactobacillus GG (LGG administration in children with CF with and without antibiotic treatment.The intestinal microbiota were analyzed by denaturing gradient gel electrophoresis (DGGE, real-time polymerase chain reaction (RT-PCR, and fluorescence in situ hybridization (FISH. Intestinal inflammation was assessed by measuring fecal calprotectin (CLP and rectal nitric oxide (rNO production in children with CF as compared with healthy controls. We then carried out a small double-blind randomized clinical trial with LGG.Twenty-two children with CF children were enrolled in the study (median age, 7 years; range, 2-9 years. Fecal CLP and rNO levels were higher in children with CF than in healthy controls (184±146 µg/g vs. 52±46 µg/g; 18±15 vs. 2.6±1.2 µmol/L NO2 (-, respectively; P<0.01. Compared with healthy controls, children with CF had significantly different intestinal microbial core structures. The levels of Eubacterium rectale, Bacteroides uniformis, Bacteroides vulgatus, Bifidobacterium adolescentis, Bifidobacterium catenulatum, and Faecalibacterium prausnitzii were reduced in children with CF. A similar but more extreme pattern was observed in children with CF who were taking antibiotics. LGG administration reduced fecal CLP and partially restored intestinal microbiota. There was a significant correlation between reduced microbial richness and intestinal inflammation.CF causes qualitative and quantitative changes in intestinal microbiota, which may represent a novel therapeutic target in the treatment of CF. Administration of probiotics restored gut microbiota, supporting

Differentiation-dependent activation of the human intestinal alkaline phosphatase promoter by HNF-4 in intestinal cells

DEFF Research Database (Denmark)

Olsen, Line; Bressendorff, Simon; Troelsen, Jesper T

2005-01-01

The intestinal alkaline phosphatase gene (ALPI) encodes a digestive brush-border enzyme, which is highly upregulated during small intestinal epithelial cell differentiation. To identify new putative promoter motifs responsible for the regulation of ALPI expression during differentiation of the en...

Lymphangiectasia of small intestine presenting as intussusception

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Katoch Pervez

2008-07-01

Full Text Available Intussusception is defined as telescoping of a segment of gastrointestinal tract into an adjacent one. In small children, it is the commonest cause of intestinal obstruction. More than 90% of childhood intussusceptions are idiopathic. We report a rare case of localized small intestinal lymphangiectasia, presenting as intussusception in a 6-month-old male child. The child presented with features of acute intestinal obstruction for which he was later operated. The gross examination of excised ileocecal mass revealed intussusception. Histopathologic examination revealed lymphangiectasia of small intestine, which acted as a lead point for ileocecal intussusception. Postoperative period was uneventful.

Lymphangiectasia of small intestine presenting as intussusception.

Science.gov (United States)

Katoch, Pervez; Bhardwaj, Subhash

2008-01-01

Intussusception is defined as telescoping of a segment of gastrointestinal tract into an adjacent one. In small children, it is the commonest cause of intestinal obstruction. More than 90% of childhood intussusceptions are idiopathic. We report a rare case of localized small intestinal lymphangiectasia, presenting as intussusception in a 6-month-old male child. The child presented with features of acute intestinal obstruction for which he was later operated. The gross examination of excised ileocecal mass revealed intussusception. Histopathologic examination revealed lymphangiectasia of small intestine, which acted as a lead point for ileocecal intussusception. Postoperative period was uneventful.

Inflammasome in Intestinal Inflammation and Cancer

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Tiago Nunes

2013-01-01

Full Text Available The activation of specific cytosolic pathogen recognition receptors, the nucleotide-binding-oligomerization-domain- (NOD- like receptors (NLRs, leads to the assembly of the inflammasome, a multimeric complex platform that activates caspase-1. The caspase-1 pathway leads to the upregulation of important cytokines from the interleukin (IL-1 family, IL-1β, and IL-18, with subsequent activation of the innate immune response. In this review, we discuss the molecular structure, the mechanisms behind the inflammasome activation, and its possible role in the pathogenesis of inflammatory bowel diseases and intestinal cancer. Here, we show that the available data points towards the importance of the inflammasome in the innate intestinal immune response, being the complex involved in the maintenance of intestinal homeostasis, correct intestinal barrier function and efficient elimination of invading pathogens.

Multispectral tissue characterization for intestinal anastomosis optimization

Science.gov (United States)

Cha, Jaepyeong; Shademan, Azad; Le, Hanh N. D.; Decker, Ryan; Kim, Peter C. W.; Kang, Jin U.; Krieger, Axel

2015-10-01

Intestinal anastomosis is a surgical procedure that restores bowel continuity after surgical resection to treat intestinal malignancy, inflammation, or obstruction. Despite the routine nature of intestinal anastomosis procedures, the rate of complications is high. Standard visual inspection cannot distinguish the tissue subsurface and small changes in spectral characteristics of the tissue, so existing tissue anastomosis techniques that rely on human vision to guide suturing could lead to problems such as bleeding and leakage from suturing sites. We present a proof-of-concept study using a portable multispectral imaging (MSI) platform for tissue characterization and preoperative surgical planning in intestinal anastomosis. The platform is composed of a fiber ring light-guided MSI system coupled with polarizers and image analysis software. The system is tested on ex vivo porcine intestine tissue, and we demonstrate the feasibility of identifying optimal regions for suture placement.

Intestinal mal-rotation in adults. CT findings

International Nuclear Information System (INIS)

Vazquez Munoz, Enrique; Ramiro Ramiro, Esther; Perez Villacastin, Benjamin; Learra Martinez, Maria C.; Franco Lopez, Maria A.

2004-01-01

We review 7 adult cases of intestinal mal-rotation who were studied with CT. All patients had a small bowel located in the right hemi abdomen, abnormal location of superior mesenteric vein relative to superior mesenteric artery. Superior mesenteric vein was located anteriorly and to the left of superior mesenteric artery. In patients who suffered intestinal volvulus a 'whirlpool' sign was observed, due to the helicoidal torsion of the intestine and mesentery surrounding superior mesenteric artery. In 3 cases CT demonstrated absence or poor development of the pancreas uncinate process. In 2 patients CT revealed polysplenia. CT played a major role in 3 patients with volvulus as a complication of intestinal mal-rotation. CT also demonstrated unsuspected mal-rotation in one asymptomatic patient. In 3 cases with classic symptoms CT confirmed the intestinal mal-rotation diagnosed by barium studies. (author)

Bioactive Milk for Intestinal Maturation in Preterm Neonates

DEFF Research Database (Denmark)

Li, Yanqi

The fetal small intestine grows dramatically fast during the second and third trimester of human pregnancy. Many intestinal functions are therefore affected by preterm birth, including gastrointestinal motility, digestive and absorptive function, mucosal barrier function, and the intestinal...

A influência do método pilates na musculatura do assoalho pélvico em mulheres no climatério: estudo de caso

Directory of Open Access Journals (Sweden)

Josiane Teresinha Bertoldi

2015-10-01

Full Text Available Objetivo: avaliar a influência dos exercícios do método Pilates na força de contração da musculatura do assoalho pélvico (MAP e na qualidade de vida (QV de mulheres no climatério. Método: amostra composta por duas mulheres (1 e (2, com 50 e 48 anos respectivamente, sem disfunção da MAP. A pré e pós-avaliação foi composta pelos protocolos: avaliação visual funcional (AFA, teste dos cones vaginais (TCV, teste de força com perineômetro modelo perina, quark® para fibras rápidas (TPFR e para fibras lentas (TPFL, e avaliação da QV com o Women´s Health Questionnaire (WHQ. O tratamento consistiu em 10 sessões de 50 minutos, 03 vezes por semana, compostas por exercícios selecionados do método Pilates. Resultados: AFA e TCV o grau de força foi máximo no pré e pós-teste, entretanto notou-se melhora da contração isolada da MAP; no TPFR houve incremento de força de 45,83% (1 e 362,50% (2, no TPFL o ganho foi de 82,43% (1 e 209,38% (2; no WHQ houve variação positiva nas dimensões: sintomas somáticos, vasomotores, menstruais, atratividade e depressão. Considerações finais: o método Pilates promove aumento da força de contração da MAP, com discreta influência na autopercepção da QV de mulheres no período do climatério, sem patologias associadas.

Starved Guts: Morphologic and Functional Intestinal Changes in Malnutrition.

Science.gov (United States)

Attia, Suzanna; Feenstra, Marjon; Swain, Nathan; Cuesta, Melina; Bandsma, Robert H J

2017-11-01

Malnutrition contributes significantly to death and illness worldwide and especially to the deaths of children younger than 5 years. The relation between intestinal changes in malnutrition and morbidity and mortality has not been well characterized; however, recent research indicates that the functional and morphologic changes of the intestine secondary to malnutrition itself contribute significantly to these negative clinical outcomes and may be potent targets of intervention. The aim of this review was to summarize current knowledge of experimental and clinically observed changes in the intestine from malnutrition preclinical models and human studies. Limited clinical studies have shown villous blunting, intestinal inflammation, and changes in the intestinal microbiome of malnourished children. In addition to these findings, experimental data using various animal models of malnutrition have found evidence of increased intestinal permeability, upregulated intestinal inflammation, and loss of goblet cells. More mechanistic studies are urgently needed to improve our understanding of malnutrition-related intestinal dysfunction and to identify potential novel targets for intervention.

Enteric Virome Sensing—Its Role in Intestinal Homeostasis and Immunity

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Rebecca N. Metzger

2018-03-01

Full Text Available Pattern recognition receptors (PRRs sensing commensal microorganisms in the intestine induce tightly controlled tonic signaling in the intestinal mucosa, which is required to maintain intestinal barrier integrity and immune homeostasis. At the same time, PRR signaling pathways rapidly trigger the innate immune defense against invasive pathogens in the intestine. Intestinal epithelial cells and mononuclear phagocytes in the intestine and the gut-associated lymphoid tissues are critically involved in sensing components of the microbiome and regulating immune responses in the intestine to sustain immune tolerance against harmless antigens and to prevent inflammation. These processes have been mostly investigated in the context of the bacterial components of the microbiome so far. The impact of viruses residing in the intestine and the virus sensors, which are activated by these enteric viruses, on intestinal homeostasis and inflammation is just beginning to be unraveled. In this review, we will summarize recent findings indicating an important role of the enteric virome for intestinal homeostasis as well as pathology when the immune system fails to control the enteric virome. We will provide an overview of the virus sensors and signaling pathways, operative in the intestine and the mononuclear phagocyte subsets, which can sense viruses and shape the intestinal immune response. We will discuss how these might interact with resident enteric viruses directly or in context with the bacterial microbiome to affect intestinal homeostasis.

Measures to minimize small intestine injury in the irradiated pelvis

International Nuclear Information System (INIS)

Green, N.; Iba, G.; Smith, W.R.

1975-01-01

Small intestine injury causes long-term suffering and high mortality. Five of 187 of our patients had developed serious small intestine injury. Four patients had corrective surgery. Three patients died. All were women. Subsequently, all patients who received definitive pelvic irradiation had small intestine roentgenograms to determine its location and mobility. Female patients, thin patients, and elderly patients had larger amounts of small intestine in the whole pelvis, a deeper cul de sac, and a greater incidence of relatively immobile small intestine. Patients with relatively immobile small intestine in the treatment field may be predisposed to injury. There was no relationship of the incidence of relatively immobile small intestine to prior pelvic surgery. We used the findings from the small intestine roentgenograms to modify individually the radiotherapy regimen so as to minimize the risk for small intestine injury. Patients were placed in the prone position to displace the small intestine out of the treatment fields used for booster dose irradiation. The treatment field was modified to exclude the small intestine. The total tumor dose delivered was determined by expectations for cure vs complications. To date, none of the patients in this study group has developed small intestine injury. Cadaver studies showed the feasibility of elective shortening of the pelvic cul de sac. The small intestine can be displaced away from the bladder, prostate, or cervix. (U.S.)

Enteric Virome Sensing-Its Role in Intestinal Homeostasis and Immunity.

Science.gov (United States)

Metzger, Rebecca N; Krug, Anne B; Eisenächer, Katharina

2018-03-23

Pattern recognition receptors (PRRs) sensing commensal microorganisms in the intestine induce tightly controlled tonic signaling in the intestinal mucosa, which is required to maintain intestinal barrier integrity and immune homeostasis. At the same time, PRR signaling pathways rapidly trigger the innate immune defense against invasive pathogens in the intestine. Intestinal epithelial cells and mononuclear phagocytes in the intestine and the gut-associated lymphoid tissues are critically involved in sensing components of the microbiome and regulating immune responses in the intestine to sustain immune tolerance against harmless antigens and to prevent inflammation. These processes have been mostly investigated in the context of the bacterial components of the microbiome so far. The impact of viruses residing in the intestine and the virus sensors, which are activated by these enteric viruses, on intestinal homeostasis and inflammation is just beginning to be unraveled. In this review, we will summarize recent findings indicating an important role of the enteric virome for intestinal homeostasis as well as pathology when the immune system fails to control the enteric virome. We will provide an overview of the virus sensors and signaling pathways, operative in the intestine and the mononuclear phagocyte subsets, which can sense viruses and shape the intestinal immune response. We will discuss how these might interact with resident enteric viruses directly or in context with the bacterial microbiome to affect intestinal homeostasis.

JAK/STAT-1 Signaling Is Required for Reserve Intestinal Stem Cell Activation during Intestinal Regeneration Following Acute Inflammation

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Camilla A. Richmond

2018-01-01

Full Text Available The intestinal epithelium serves as an essential barrier to the outside world and is maintained by functionally distinct populations of rapidly cycling intestinal stem cells (CBC ISCs and slowly cycling, reserve ISCs (r-ISCs. Because disruptions in the epithelial barrier can result from pathological activation of the immune system, we sought to investigate the impact of inflammation on ISC behavior during the regenerative response. In a murine model of αCD3 antibody-induced small-intestinal inflammation, r-ISCs proved highly resistant to injury, while CBC ISCs underwent apoptosis. Moreover, r-ISCs were induced to proliferate and functionally contribute to intestinal regeneration. Further analysis revealed that the inflammatory cytokines interferon gamma and tumor necrosis factor alpha led to r-ISC activation in enteroid culture, which could be blocked by the JAK/STAT inhibitor, tofacitinib. These results highlight an important role for r-ISCs in response to acute intestinal inflammation and show that JAK/STAT-1 signaling is required for the r-ISC regenerative response.

Intestinal Volvulus in Idiopathic Steatorrhea

Science.gov (United States)

Warner, H. A.; Kinnear, D. G.; Cameron, D. G.

1963-01-01

Volvulus of the intestine has recently been observed in three patients with idiopathic steatorrhea in relapse. Two patients gave a history of intermittent abdominal pain, distension and obstipation. Radiographic studies during these attacks revealed obstruction at the level of the sigmoid colon. Reduction under proctoscopic control was achieved in one instance, spontaneous resolution occurring in the other. The third patient presented as a surgical emergency and underwent operative reduction of a small intestinal volvulus. Persistence of diarrhea and weight loss postoperatively led to further investigation and a diagnosis of idiopathic steatorrhea. In all cases, treatment resulted in clinical remission with a coincident disappearance of obstructive intestinal symptoms. The pathogenesis of volvulus in sprue is poorly understood. Atonicity and dilatation of the bowel and stretching of the mesentery likely represent important factors. The symptoms of recurrent abdominal pain and distension in idiopathic steatorrhea necessitate an increased awareness of intestinal volvulus as a complication of this disease. ImagesFig. 1Fig. 2Fig. 3Figs. 4 and 5Fig. 6 PMID:13998948

Regulation of intestinal health by branched-chain amino acids.

Science.gov (United States)

Zhou, Hua; Yu, Bing; Gao, Jun; Htoo, John Khun; Chen, Daiwen

2018-01-01

Besides its primary role in the digestion and absorption of nutrients, the intestine also interacts with a complex external milieu, and is the first defense line against noxious pathogens and antigens. Dysfunction of the intestinal barrier is associated with enhanced intestinal permeability and development of various gastrointestinal diseases. The branched-chain amino acids (BCAAs) are important nutrients, which are the essential substrates for protein biosynthesis. Recently, emerging evidence showed that BCAAs are involved in maintaining intestinal barrier function. It has been reported that dietary supplementation with BCAAs promotes intestinal development, enhances enterocyte proliferation, increases intestinal absorption of amino acids (AA) and glucose, and improves the immune defenses of piglets. The underlying mechanism of these effects is mediated by regulating expression of genes and proteins associate with various signaling pathways. In addition, BCAAs promote the production of beneficial bacteria in the intestine of mice. Compelling evidence supports the notion that BCAAs play important roles in both nutrition and intestinal health. Therefore, as functional amino acids with various physiological effects, BCAAs hold key roles in promoting intestinal development and health in animals and humans. © 2017 Japanese Society of Animal Science.

Therapeutic hypothermia reduces intestinal ischemia/reperfusion ...

African Journals Online (AJOL)

The detached intestinal epithelial cells in hypothermia group showed ... of apoptosis than those in normothermia group at 4 h (17.30 ± 2.56 vs. ... intestinal ischemia/reperfusion (IR) injury, which could be attenuated by therapeutic hypothermia.

Gintonin absorption in intestinal model systems

Directory of Open Access Journals (Sweden)

Byung-Hwan Lee

2018-01-01

Conclusion: The present study shows that gintonin could be absorbed in the intestine through transcellular and paracellular diffusion, and active transport. In addition, the lipid component of gintonin might play a key role in its intestinal absorption.

Radiation pressure calibration and test mass reflectivities for LISA Pathfinder

International Nuclear Information System (INIS)

Korsakova, Natalia; Kaune, Brigitte

2017-01-01

This paper describes a series of experiments which were carried out during the main operations of LISA Pathfinder. These experiments were performed by modulating the power of the measurement and reference beams. In one series of experiments the beams were sequentially switched on and off. In the other series of experiments the powers of the beams were modulated within 0.1% and 1% of the constant power. These experiments use recordings of the total power measured on the photodiodes to infer the properties of the Optical Metrology System (OMS), such as reflectivities of the test masses and change of the photodiode efficiencies with time. In the first case the powers are back propagated from the different photodiodes to the same place on the optical bench to express the unknown quantities in the measurement with the complimentary photodiode measurements. They are combined in the way that the only unknown left is the test mass reflectivities. The second experiment compared two estimates of the force applied to the test masses due to the radiation pressure that appears because of the beam modulations. One estimate of the force is inferred from the measurements of the powers on the photodiodes and propagation of this measurement to the test masses. The other estimation of the force is done by calculating it from the change in the main scientific output of the instrument – differential displacement of the two test masses. (paper)

Radiation pressure calibration and test mass reflectivities for LISA Pathfinder

Science.gov (United States)

Korsakova, Natalia; Kaune, Brigitte; LPF Collaboration

2017-05-01

This paper describes a series of experiments which were carried out during the main operations of LISA Pathfinder. These experiments were performed by modulating the power of the measurement and reference beams. In one series of experiments the beams were sequentially switched on and off. In the other series of experiments the powers of the beams were modulated within 0.1% and 1% of the constant power. These experiments use recordings of the total power measured on the photodiodes to infer the properties of the Optical Metrology System (OMS), such as reflectivities of the test masses and change of the photodiode efficiencies with time. In the first case the powers are back propagated from the different photodiodes to the same place on the optical bench to express the unknown quantities in the measurement with the complimentary photodiode measurements. They are combined in the way that the only unknown left is the test mass reflectivities. The second experiment compared two estimates of the force applied to the test masses due to the radiation pressure that appears because of the beam modulations. One estimate of the force is inferred from the measurements of the powers on the photodiodes and propagation of this measurement to the test masses. The other estimation of the force is done by calculating it from the change in the main scientific output of the instrument - differential displacement of the two test masses.

Spectrum of diseases in acute intestinal obstruction

International Nuclear Information System (INIS)

Masud, M.; Khan, A.; Gondal, Z.I.; Adil, M.

2015-01-01

To determine the etiological spectrum of acute intestinal obstruction in our clinical setup Military Hospital Rawalpindi. Study Design: Descriptive study. Place and Duration of Study: Surgical department of Military Hospital, Rawalpindi from Jul 2012 to Jul 2013, over a period of about 1 year. Material and Methods: A total of 120 patients with acute mechanical intestinal obstruction who underwent laparotomy were included in our study while those with non-mechanical intestinal obstruction like history of trauma and paralytic ileus were excluded from the study. All the patients were selected by non-probability purposive sampling technique. Emergency laparotomy was done and operative findings were recorded. Results: A total of 120 patients with mechanical intestinal obstruction were included in this study out of which 93 (69.17%) were female and remaining 27 (30.83%) were males. Male to female ratio was 1:2.24. Age range of patients was 22-85 years. Out of 120 patients operated for acute intestinal obstruction post-op adhesions were found in 37 (30.83%) patients followed by intestinal tuberculosis in 23 (19.17%) patients, obstructed inguinal hernias in 13 (10.83%), gut malignancies in 15 (12.5%) , Meckel's diverticulum with bands in 7 (5.83%), volvulus in 7 (5.83%), perforated appendix in 6 (5%), intussusception in 2 (1.7%), inflammatory bands in 5 (4.17%), trichobezoar and faecal impaction in 2 (1.7%) while in 3 (2.5%) patients no definite cause was found. Conclusion: Post-op adhesions are the commonest cause of mechanical intestinal obstruction in our setup followed by intestinal tuberculosis as second most common clinical pattern of presentation. (author)

Neonatal intestinal obstruction in Benin, Nigeria

Directory of Open Access Journals (Sweden)

Osifo Osarumwense

2009-01-01

Full Text Available Background: Intestinal obstruction is a life threatening condition in the newborn, with attendant high mortality rate especially in underserved subregion. This study reports the aetiology, presentation, and outcome of intestinal obstruction management in neonates. Materials and Methods: A prospective study of neonatal intestinal obstruction at the University of Benin Teaching Hospital, Benin, Nigeria, between January 2006-June 2008. Data were collated on a structured proforma and analysed for age, sex, weight, presentation, type/date of gestation/delivery, aetiology, clinical presentation, associated anomaly, treatment, and outcome. Results: There were 71 neonates, 52 were males and 19 were females (2.7:1. Their age range was between 12 hours and 28 days (mean, 7.9 ± 2.7 days and they weighed between 1.8 and 5.2 kg (average, 3.2 kg. The causes of intestinal obstruction were: Anorectal anomaly, 28 (39.4%; Hirschsprung′s disease, 8 (11.3%′ prematurity, 3 (4.2%; meconeum plug, 2 (2.8%; malrotation, 6 (8.5%; intestinal atresia, 8 (11.3%; necrotising enterocolitis (NEC, 4 (5.6%; obstructed hernia, 4 (5.6%; and spontaneous gut perforation, 3 (4.2%. Also, 27 (38% children had colostomy, 24 (33.8% had laparotomy, 9 (12.8% had anoplasty, while 11 (15.4% were managed nonoperatively. A total of 41 (57.7% neonates required incubator, 26 (36.6% needed total parenteral nutrition, while 15 (21.1% require d paediatric ventilator. Financial constraint, late presentation, presence of multiple anomalies, aspiration, sepsis, gut perforation, and bowel gangrene were the main contributors to death. Neonates with lower obstructions had a better outcome compared to those having upper intestinal obstruction ( P < 0.0001. Conclusion: Outcomes of intestinal obstruction are still poor in our setting; late presentation, financial constraints, poor parental motivation and lack of basic facilities were the major determinants of mortality.

Tissue response after radiation exposure. Intestine

International Nuclear Information System (INIS)

Otsuka, Kensuke; Tomita, Masanori; Yamauchi, Motohiro; Iwasaki, Toshiyasu

2014-01-01

Gastrointestinal syndrome followed by 'gut death' is due to intestinal disorders. This syndrome is induced by high-dose (>10 Gy) of ionizing radiation. Recovery from the gastrointestinal syndrome would depend on the number of survived clonogens and regeneration capability of crypts. These tissue alterations can be observed by high-dose radiation, however, cellular dynamics in crypts can be affected by low-dose radiation. For example, Potten et al. found that low-dose radiation induce apoptosis of intestinal stem cells, which produce all differentiated function cells. Recently, intestinal stem cells are characterized by molecular markers such as Lgr5. Since intestinal adenomas can be induced by deletion of Apc gene in Lgr5 + stem cells, it is widely recognized that Lgr5 + stem cells are the cell-of-origin of cancer. Duodenal Lgr5 + stem cells are known as radioresistant cells, however, we found that ionizing radiation significantly induces the turnover of colonic Lgr5 + stem cells. Combined with the knowledge of other radioresistant markers, stem-cell dynamics in tissue after irradiation are becoming clear. The present review introduces the history of gastrointestinal syndrome and intestinal stem cells, and discusses those future perspectives. (author)

Bile acids in regulation of intestinal physiology.

LENUS (Irish Health Repository)

Keating, Niamh

2009-10-01

In addition to their roles in facilitating lipid digestion and absorption, bile acids are recognized as important regulators of intestinal function. Exposure to bile acids can dramatically influence intestinal transport and barrier properties; in recent years, they have also become appreciated as important factors in regulating cell growth and survival. Indeed, few cells reside within the intestinal mucosa that are not altered to some degree by exposure to bile acids. The past decade saw great advances in the knowledge of how bile acids exert their actions at the cellular and molecular levels. In this review, we summarize the current understanding of the role of bile acids in regulation of intestinal physiology.

Factors influencing physiological FDG uptake in the intestine

International Nuclear Information System (INIS)

Yasuda, Seiei; Takahashi, Wakoh; Takagi, Shigeharu; Fujii, Hirofumi; Ide, Michiru; Shohtsu, Akira

1998-01-01

The intestine is a well-known site of physiological 18 F-fluorodeoxyglucose (FDG) accumulation in positron emission tomography (PET). To identify factors influencing physiological FDG uptake in the intestine, the intensity of FDG uptake was evaluated in a total of 1,068 healthy adults. Non-attenuation-corrected whole-body PET images were obtained for all subjects and visually evaluated. Subjects were then classified into two groups according to the intensity of intestinal FDG uptake. Sex, age, presence or absence of constipation, and serum glucose, hemoglobin A 1 c, and free fatty acid levels were compared between the two groups. High intestinal FDG uptake was observed at an overall rate of 11.0%. Sex (female), age, and bowel condition (constipation) were found to affect intestinal FDG uptake. The factors we identified lead to further questions the relationship between intestinal motility and glucose uptake that warrant further study. (author)

Modelo de suprimento sanguíneo do intestino grosso do tamanduá bandeira (Myrmecophaga tridactyla Model of blood supply to the intestine of Giant anteater (Myrmecophaga tridactyla

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Ana Lúcia Rezende de Souza

2010-03-01

Full Text Available Em seis animais adultos Myrmecophaga tridactyla estudou-se o modelo de suprimento sanguíneo do intestino grosso, que é dependente das artérias mesentérica cranial (AMCr e caudal (AMC. Os espécimes coletados conforme as normas do IBAMA (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis foram perfundidos com água (40 C, injetados com látex corado, fixados em formol e conservados em solução alcoólica (50%. O mesocólon está disposto na linha sagital mediana e fixa o intestino grosso à parede dorsal do abdome. Derivaram da AMC: a artéria retal cranial, sete a 14 artérias cólicas e uma ou duas artérias ileocólicas, que apresentaram anastomoses de irrigação com a AMCr. A AMC finaliza-se na borda mesocólica das alças intestinais, emitindo ramos cólicos retos a partir das arcadas justacólicas, que penetram na intimidade da musculatura longitudinal. Ao longo do trajeto da AMC foram observadas ilhas arteriais, e a região ileocólica apresentou maior densidade vascular.This research aimed to study the model of large intestine blood supply, which is dependent on the cranial mesenteric artery (AMCr and caudal mesenteric artery (AMC, in six adults of Myrmecophaga tridactyla. The specimens were collected in accordance with the IBAMA standards (Brazilian Institute of the Environment and were perfused with water (40 C, injected with colored latex, fixed in formaldehyde and preserved in alcohol solution (50%. The mesocolon is positioned in the median sagittal line and fixes the large intestine to the dorsal wall of the abdomen. The following is derived from the AMC: the cranial rectal artery, from 7 to 14 colic arteries and one or two ileocolic arteries, which present irrigation anastomosis with AMCr. The AMC finishes at the mesocolic edge of the bowel loop, generating straight colic branches from juxtacolic arcades, which penetrate the intimacy of longitudinal muscles. Arterial islands were observed along the AMC

Evolutionary insights into postembryonic development of adult intestinal stem cells

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Ishizuya-Oka Atsuko

2011-11-01

Full Text Available Abstract In the adult vertebrate intestine, multi-potent stem cells continuously generate all of the epithelial cells throughout the adulthood. While it has long been known that the frog intestine is formed via the development of adult intestinal stem cells during thyroid hormone (TH-dependent metamorphosis, the basic structure of the adult intestine is formed by birth in mammals and it is unclear if the subsequent maturation of the intestine involves any changes in the intestinal stem cells. Two recent papers showing that B lymphocyte-induced maturation protein 1 (Blimp1 regulates postnatal epithelial stem cell reprogramming during mouse intestinal maturation support the model that adult intestinal stem cells are developed during postembryonic development in mammals, in a TH-dependent process similar to intestinal remodeling during amphibian metamorphosis. Since the formation of the adult intestine in both mammals and amphibians is closely associated with the adaptation from aquatic to terrestrial life during the peak of endogenous TH levels, the molecular mechanisms by which the adult stem cells are developed are likely evolutionally conserved.

Coupling of relative intensity noise and pathlength noise to the length measurement in the optical metrology system of LISA Pathfinder

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Wittchen, Andreas; the LPF Collaboration

2017-05-01

LISA Pathfinder is a technology demonstration mission for the space-based gravitational wave observatory, LISA. It demonstrated that the performance requirements for the interferometric measurement of two test masses in free fall can be met. An important part of the data analysis is to identify the limiting noise sources. [1] This measurement is performed with heterodyne interferometry. The performance of this optical metrology system (OMS) at high frequencies is limited by sensing noise. One such noise source is Relative Intensity Noise (RIN). RIN is a property of the laser, and the photodiode current generated by the interferometer signal contains frequency dependant RIN. From this electric signal the phasemeter calculates the phase change and laser power, and the coupling of RIN into the measurement signal depends on the noise frequency. RIN at DC, at the heterodyne frequency and at two times the heterodyne frequency couples into the phase. Another important noise at high frequencies is path length noise. To reduce the impact this noise is suppressed with a control loop. Path length noise not suppressed will couple directly into the length measurement. The subtraction techniques of both noise sources depend on the phase difference between the reference signal and the measurement signal, and thus on the test mass position. During normal operations we position the test mass at the interferometric zero, which is optimal for noise subtraction purposes. This paper will show results from an in-flight experiment where the test mass position was changed to make the position dependant noise visible.

Related radiation effects on the intestine and their treatment

International Nuclear Information System (INIS)

Bardychev, M.S.; Kurpeshcheva, A.K.; Kaplan, M.A.

1978-01-01

Late radiation injuries of the intestine are frequent after radiation therapy of malignant tumours of female genitalia and some other tumours due to which the intestine gets into the irradiation field. On the basis of the analysis of 80 patients with late radiation injuries of intestine which developed at remote terms after radiation therapy of cervix uteri cancer and corpus uteri (65 patients) and other tumours, peculiarities of the clinical course and treatment of radiation enterocolitis, rectosigmoidites and rectites are discussed. In 39 patients these injuries were concomitant with late radiation injuries of the skin and subcutaneous soft tissues. The clinical course of radiation unjuries of the intestine was defined by the character of the pathological process in the intestine and was more sharply marked in patients suffering from radiation enterocolites. It was established that one of the pathogenetic mechanisms of late radiation injuries of the intestine was a disorder of the absorption function of the intestine. Local treatment of radiation injuries of the intestine should be combined with a general one the important component of which is a parenteral diet

Chronic intestinal pseudoobstruction syndrome

Energy Technology Data Exchange (ETDEWEB)

Yeon, Kyung Mo; Seo, Jeong Kee; Lee, Yong Seok [Seoul National University Children' s Hospital, Seoul (Korea, Republic of)

1992-03-15

Chronic intestinal pseudoobstruction syndrome is a rare clinical condition in which impaired intestinal peristalsis causes recurrent symptoms of bowel obstruction in the absence of a mechanical occlusion. This syndrome may involve variable segments of small or large bowel, and may be associated with urinary bladder retention. This study included 6 children(3 boys and 3 girls) of chronic intestinal obstruction. Four were symptomatic at birth and two were of the ages of one month and one year. All had abdominal distension and deflection difficulty. Five had urinary bladder distension. Despite parenteral nutrition and surgical intervention(ileostomy or colostomy), bowel obstruction persisted and four patients expired from sepses within one year. All had gaseous distension of small and large bowel on abdominal films. In small bowel series, consistent findings were variable degree of dilatation, decreased peristalsis(prolonged transit time) and microcolon or microrectum. This disease entity must be differentiated from congenital megacolon, ileal atresia and megacystis syndrome.

Ultrasonography of small intestinal obstructions: a contemporary approach.

Science.gov (United States)

Garcia, D A A; Froes, T R; Vilani, R G D O C; Guérios, S D; Obladen, A

2011-09-01

To assess the accuracy of intestinal ultrasound for diagnosis of intestinal obstruction in dogs and cats. A prospective clinical study was performed. Inclusion criteria were dogs and cats with clinical signs suggestive of gastrointestinal obstruction. Animals with no obstruction detected on ultrasound were excluded if they could not be monitored for 48 hours to confirm absence of obstruction. Sonographic diagnosis of small intestinal obstruction was based on identification of at least two findings suggestive of intestinal obstruction. Ninety-two patients suspected of having intestinal obstruction were included. Correct diagnosis of intestinal obstruction was made in 21 cases (23%), and in 68 (74%) this diagnosis was excluded. Interpretation of the images on prospective analysis had sensitivity, positive predictive, specificity and negative predictive values of 100%, 87.5%, 95.8% and 100%, respectively. Ultrasonography is an excellent method for investigation of animals with gastrointestinal disorders, and is particularly useful for excluding obstructive processes. © 2011 British Small Animal Veterinary Association.

Natural compound methyl protodioscin protects against intestinal inflammation through modulation of intestinal immune responses

OpenAIRE

Zhang, Rongli; Gilbert, Shila; Yao, Xinsheng; Vallance, Jefferson; Steinbrecher, Kris; Moriggl, Richard; Zhang, Dongsheng; Eluri, Madhu; Chen, Haifeng; Cao, Huiqing; Shroyer, Noah; Denson, Lee; Han, Xiaonan

2015-01-01

Dioscoreaceae, a kind of yam plant, has been recommended for treatment of chronic inflammatory conditions. However, the mechanisms are poorly defined. Methyl protodioscin (MPD) is one of the main bioactive components in Dioscoreaceae. Here, we aim to determine the mechanisms by which MPD ameliorates intestinal inflammation. Surgical intestinal specimens were collected from inflammatory bowel diseases (IBD) patients to perform organ culture. Experimental colitis was induced in mice by dextran ...

INTESTINAL OBSTRUCTION

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Whipple, G. H.; Stone, H. B.; Bernheim, B. M.

1913-01-01

Closed duodenal loops may be made in dogs by ligatures placed just below the pancreatic duct and just beyond the duodenojejunal junction, together with a posterior gastro-enterostomy. These closed duodenal loop dogs die with symptoms like those of patients suffering from volvulus or high intestinal obstruction. This duodenal loop may simulate closely a volvulus in which there has been no vascular disturbance. Dogs with closed duodenal loops which have been washed out carefully survive a little longer on the average than animals with unwashed loops. The duration of life in the first instance is one to three days, with an average of about forty-eight hours. The dogs usually lose considerable fluid by vomiting and diarrhea. A weak pulse, low blood pressure and temperature are usually conspicuous in the last stages. Autopsy shows more or less splanchnic congestion which may be most marked in the mucosa of the upper small intestine. The peritoneum is usually clear and the closed loop may be distended with thin fluid, or collapsed, and contain only a small amount of pasty brown material. The mucosa of the loop may show ulceration and even perforation, but in the majority of cases it is intact and exhibits only a moderate congestion. Simple intestinal obstruction added to a closed duodenal loop does not modify the result in any manner, but it may hasten the fatal outcome. The liver plays no essential role as a protective agent against this poison, for a dog with an Eck fistula may live three days with a closed loop. A normal dog reacts to intraportal injection and to intravenous injection of the toxic substance in an identical manner. Drainage of this loop under certain conditions may not interfere with the general health over a period of weeks or months. Excision of the part of the duodenum included in this loop causes no disturbance. The material from the closed duodenal loops contains no bile, pancreatic juice, gastric juice, or split products from the food. It can be

Intestinal cholesterol secretion : future clinical implications

NARCIS (Netherlands)

Jakulj, L.; Besseling, J.; Stroes, E. S. G.; Groen, A. K.

2013-01-01

Together with the liver, the intestine serves as a homeostatic organ in cholesterol metabolism. Recent evidence has substantiated the pivotal role of the intestine in reverse cholesterol transport (RCT). RCT is a fundamental antiatherogenic pathway, mediating the removal of cholesterol from tissues

Intestinal cholesterol secretion: future clinical implications

NARCIS (Netherlands)

Jakulj, L.; Besseling, J.; Stroes, E. S. G.; Groen, A. K.

2013-01-01

Together with the liver, the intestine serves as a homeostatic organ in cholesterol metabolism. Recent evidence has substantiated the pivotal role of the intestine in reverse cholesterol transport (RCT). RCT is a fundamental antiatherogenic pathway, mediating the removal of cholesterol from tissues

Primary intestinal hodgkin′s lymphoma: An uncommon presentation

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Shruti Sharma

2013-01-01

Full Text Available Primary intestinal lymphoma is a rare lymphoproliferative neoplasm of the small intestine. The primary nature is established on the basis of lack of evidence of lymphoma on chest X-ray, computerized tomographic scan, peripheral blood or bone marrow puncture. Tumor involvement is limited to the gastrointestinal tract, the criteria for inclusion are that the symptoms related to the small intestine are predominant or the only symptoms at the time of laparotomy. Hodgkin′s lymphoma (HL primarily in the small intestine is a rare entity and an uncommon presentation of the disease. Ileum is the more common site of infliction than the jejunum because of its abundant lymphoid follicles. Here, we present a case of primary intestinal HL, in a 30-year-old male.

Effects of probiotics and antibiotics on the intestinal homeostasis in a computer controlled model of the large intestine

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Rehman Ateequr

2012-03-01

Full Text Available Abstract Background Antibiotic associated diarrhea and Clostridium difficile infection are frequent complications of broad spectrum antibiotic therapy. Probiotic bacteria are used as therapeutic and preventive agents in these disorders, but the exact functional mechanisms and the mode of action are poorly understood. The effects of clindamycin and the probiotic mixture VSL#3 (containing the 8 bacterial strains Streptococcus thermophilus, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus delbrueckii subsp. Bulgaricus consecutively or in combination were investigated and compared to controls without therapy using a standardized human fecal microbiota in a computer-controlled in vitro model of large intestine. Microbial metabolites (short chain fatty acids, lactate, branched chain fatty acids, and ammonia and the intestinal microbiota were analyzed. Results Compared to controls and combination therapy, short chain fatty acids and lactate, but also ammonia and branched chain fatty acids, were increased under probiotic therapy. The metabolic pattern under combined therapy with antibiotics and probiotics had the most beneficial and consistent effect on intestinal metabolic profiles. The intestinal microbiota showed a decrease in several indigenous bacterial groups under antibiotic therapy, there was no significant recovery of these groups when the antibiotic therapy was followed by administration of probiotics. Simultaneous application of anti- and probiotics had a stabilizing effect on the intestinal microbiota with increased bifidobacteria and lactobacilli. Conclusions Administration of VSL#3 parallel with the clindamycin therapy had a beneficial and stabilizing effect on the intestinal metabolic homeostasis by decreasing toxic metabolites and protecting the endogenic microbiota from destruction. Probiotics could be a reasonable

Surgical management of radiation injury to the small intestine

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Swan, R.W.; Fowler, W.C. Jr., Boronow, R.C.

1976-01-01

Severe injury of the small intestine represents one of the most tragic complications of radiation of the pelvis and abdomen. Not uncommonly, patients die from the radiation or the treatment of its intestinal complications. More commonly, patients become intestinal cripples, secondary to chronic partial obstruction of the small intestine and malnutrition associated with the stagnant loop syndrome, as previously reported by one of us. Management results have been discouraging, usually because of a general lack of clinical recognition and understanding of radiation injury to the intestine. Medical management has not been satisfactory. It may provide temporary relief from symptoms, but not long-lasting. Surgical management, although frequently curative, has been associated with high death and morbidity rates. Many surgical procedures have been used in treating radiation injury to the small intestine. Generally, these fall into two categories: first, intestinal resection with primary anastomosis; and second, enteroenteric or enterocolic bypass. In the literature are reflected advocates for each method of surgical management.

Surgical treatment of radiation induced injuries of the intestine

Energy Technology Data Exchange (ETDEWEB)

Schmitt, E.H.; Symmonds, R.E.

1981-12-01

In the patient who has received high dose irradiation of the pelvis and abdomen, all abdominopelvic operations should be avoided, unless it is absolutely essential. Persisting obstruction, hemorrhage, intestinal perforation with peritonitis and with abscess and fistula formation are valid indications for surgical intervention. Ninety-three patients have been operated upon for these complications after irradiation. Some anastomotic dehiscence occurred in ten patients. Six operative deaths occurred. Of the 93 patients, 65 were managed by means of complete resection of the involved segment of intestine, followed by restoration of intestinal continuity by means of an end-to-end anastomosis. This is the treatment of choice when the involved area can be safely resected. In the absence of actual intestinal necrosis and when segments of strictured small intestine are adherent deep in the pelvis, and intestinal bypass procedure may represent the treatment of choice. This was accomplished in 20 patients, two of whom eventually required a second operation for resection of the bypassed segment of intestine.

Surgical treatment of radiation induced injuries of the intestine

International Nuclear Information System (INIS)

Schmitt, E.H.; Symmonds, R.E.

1981-01-01

In the patient who has received high dose irradiation of the pelvis and abdomen, all abdominopelvic operations should be avoided, unless it is absolutely essential. Persisting obstruction, hemorrhage, intestinal perforation with peritonitis and with abscess and fistula formation are valid indications for surgical intervention. Ninety-three patients have been operated upon for these complications after irradiation. Some anastomotic dehiscence occurred in ten patients. Six operative deaths occurred. Of the 93 patients, 65 were managed by means of complete resection of the involved segment of intestine, followed by restoration of intestinal continuity by means of an end-to-end anastomosis. This is the treatment of choice when the involved area can be safely resected. In the absence of actual intestinal necrosis and when segments of strictured small intestine are adherent deep in the pelvis, and intestinal bypass procedure may represent the treatment of choice. This was accomplished in 20 patients, two of whom eventually required a second operation for resection of the bypassed segment of intestine

Macrophages in intestinal homeostasis and inflammation

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Bain, Calum C; Mowat, Allan McI

2014-01-01

The intestine contains the largest pool of macrophages in the body which are essential for maintaining mucosal homeostasis in the face of the microbiota and the constant need for epithelial renewal but are also important components of protective immunity and are involved in the pathology of inflammatory bowel disease (IBD). However, defining the biological roles of intestinal macrophages has been impeded by problems in defining the phenotype and origins of different populations of myeloid cells in the mucosa. Here, we discuss how multiple parameters can be used in combination to discriminate between functionally distinct myeloid cells and discuss the roles of macrophages during homeostasis and how these may change when inflammation ensues. We also discuss the evidence that intestinal macrophages do not fit the current paradigm that tissue-resident macrophages are derived from embryonic precursors that self-renew in situ, but require constant replenishment by blood monocytes. We describe our recent work demonstrating that classical monocytes constantly enter the intestinal mucosa and how the environment dictates their subsequent fate. We believe that understanding the factors that drive intestinal macrophage development in the steady state and how these may change in response to pathogens or inflammation could provide important insights into the treatment of IBD. PMID:24942685

Small Intestinal Obstruction Caused by Anisakiasis

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Yuichi Takano

2013-01-01

Full Text Available Small intestinal anisakiasis is a rare disease that is very difficult to diagnose, and its initial diagnosis is often surgical. However, it is typically a benign disease that resolves with conservative treatment, and unnecessary surgery can be avoided if it is appropriately diagnosed. This case report is an example of small intestinal obstruction caused by anisakiasis that resolved with conservative treatment. A 63-year-old man admitted to our department with acute abdominal pain. A history of raw fish (sushi ingestion was recorded. Abdominal CT demonstrated small intestinal dilatation with wall thickening and contrast enhancement. Ascitic fluid was found on the liver surface and in the Douglas pouch. His IgE (RIST was elevated, and he tested positive for the anti-Anisakis antibodies IgG and IgA. Small intestinal obstruction by anisakiasis was highly suspected and conservative treatment was performed, ileus tube, fasting, and fluid replacement. Symptoms quickly resolved, and he was discharged on the seventh day of admission. Small intestinal anisakiasis is a relatively uncommon disease, the diagnosis of which may be difficult. Because it is a self-limiting disease that usually resolves in 1-2 weeks, a conservative approach is advisable to avoid unnecessary surgery.

Primary intestinal lymphangiectasia in adults - diagnostic and therapeutic challenge

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Jocić Tatiana

2018-01-01

Full Text Available Introduction. Primary intestinal lymphangiectasia is a rare disorder, characterized by abnormal dilation of intestinal lymphatic vessels and extensive enteric loss of lymph rich in plasma proteins, lymphocytes and chylomicrons. The main characteristics of the disease are hypoalbuminemia, hypogammaglobulinemia, lymphocytopenia, and more rarely, the deficit of liposoluble vitamins and anemia. Except for primary, there are secondary lymphangiectasia, associated with celiac disease, malignant, infective and inflammatory diseases of the small intestine, fibrosis, liver and cardiovascular diseases. Case report. A male, 33 years of age, presented for his medical examination suffering from diarrhea and edema. The diagnosis was established upon the histological examination of a small intestine biopsy during double balloon enteroscopy, which revealed changes only in one segment of the intestine examined. Such a finding was later confirmed by the video endoscopy capsule. Conclusion. The diagnosis of intestinal lymphangiectasia is usually established before the age of 3, but it can also be diagnosed in adults. The diagnosis is based on the histological analysis of the intestinal mucosa biopsy, obtained by endoscopic procedures. The diagnosis of primary intestinal lymphangiectasia is also made upon the exclusion of secondary causes.

Intestinal Anisakiasis Treated Successfully with Prednisolone and Olopatadine Hydrochloride

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Hideki Toyoda

2016-02-01

Full Text Available The clinical characteristic of gastrointestinal anisakiasis is severe abdominal pain after eating raw fish. Intestinal anisakiasis is more uncommon than gastric anisakiasis. Most patients with intestinal anisakiasis need hospitalization because anisakiasis can cause intestinal obstruction, ileus, peritonitis or intestinal perforation. We report a case of intestinal anisakiasis. A 43-year-old woman presented with symptoms of intermittent abdominal pain 2 days after eating raw fish. Her brother had eaten the same food and had been suffering from gastric anisakiasis. Abdominal ultrasonography in this patient showed localized jejunal wall thickening with dilated lumen of proximal jejunum and ascites. According to the clinical course and examinations, she was diagnosed with intestinal anisakiasis. Administration of prednisolone 5 mg/day and olopatadine hydrochloride 10 mg/day improved her symptoms quickly without hospitalization. Prednisolone was administered for 10 days, and olopatadine hydrochloride was administered for a total of 6 weeks according to ultrasonographic findings. Six months after the treatment, the abdominal ultrasonography demonstrated normal findings. This case demonstrates that ultrasonography was quite useful for the diagnosis and surveillance of intestinal anisakiasis. Furthermore, treatment with corticosteroid and an antiallergic agent could be an option for patients with intestinal anisakiasis.

Intestinal lymphangiectasia associated with recurrence of histiocytosis X.

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Hui, C K

2011-09-01

Intestinal lymphangiectasia may occur as a primary congenital disorder or a secondary disorder. Secondary lymphangiectasia could be associated with diseases such as abdominal carcinoma, retroperitoneal fibrosis or chronic pancreatitis. This is the first reported case of intestinal lymphangiectasia associated with recurrent histiocytosis X. This case report illustrates the need for more prospective, well-designed studies to determine the natural history and outcome of intestinal lymphangiectasia in the duodenum. Hopefully, these studies will also help clinicians identify which group of patients with intestinal lymphangiectasia in the duodenum is more likely to have a secondary cause.

Upper intestinal lipids regulate energy and glucose homeostasis.

Science.gov (United States)

Cheung, Grace W C; Kokorovic, Andrea; Lam, Tony K T

2009-09-01

Upon the entry of nutrients into the small intestine, nutrient sensing mechanisms are activated to allow the body to adapt appropriately to the incoming nutrients. To date, mounting evidence points to the existence of an upper intestinal lipid-induced gut-brain neuronal axis to regulate energy homeostasis. Moreover, a recent discovery has also revealed an upper intestinal lipid-induced gut-brain-liver neuronal axis involved in the regulation of glucose homeostasis. In this mini-review, we will focus on the mechanisms underlying the activation of these respective neuronal axes by upper intestinal lipids.

Intestinal Parasitic Infections among Pregnant Women in Venezuela

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2006-01-01

Full Text Available Introduction. Intestinal parasitic infections, especially due to helminths, increase anemia in pregnant women. The results of this are low pregnancy weight gain and IUGR, followed by LBW, with its associated greater risks of infection and higher perinatal mortality rates. For these reasons, in the setting of no large previous studies in Venezuela about this problem, a national multicentric study was conducted. Methods. Pregnant women from nine states were studied, a prenatal evaluation with a coproparasitological study. Univariated and multivariated analyses were made to determine risk factors for intestinal parasitosis and related anemia. Results. During 19 months, 1038 pregnant women were included and evaluated. Intestinal parasitosis was evidenced in 73.9%: A lumbricoides 57.0%, T trichiura 36.0%, G lamblia 14.1%, E hystolitica 12.0%, N americanus 8.1%, E vermicularis 6.3%, S stercoralis 3.3%. Relative risk for anemia in those women with intestinal parasitosis was 2.56 ( P<.01 . Discussion. Intestinal parasitoses could be associated with conditions for development of anemia at pregnancy. These features reflect the need of routine coproparasitological study among pregnant women in rural and endemic zones for intestinal parasites. Further therapeutic and prophylactic protocols are needed. Additional research on pregnant intestinal parasitic infection impact on newborn health is also considered.

Intestinal Parasitic Infections among Pregnant Women in Venezuela

Science.gov (United States)

Rodríguez-Morales, Alfonso J.; Barbella, Rosa A.; Case, Cynthia; Arria, Melissa; Ravelo, Marisela; Perez, Henry; Urdaneta, Oscar; Gervasio, Gloria; Rubio, Nestor; Maldonado, Andrea; Aguilera, Ymora; Viloria, Anna; Blanco, Juan J.; Colina, Magdary; Hernández, Elizabeth; Araujo, Elianet; Cabaniel, Gilberto; Benitez, Jesús; Rifakis, Pedro

2006-01-01

Introduction. Intestinal parasitic infections, especially due to helminths, increase anemia in pregnant women. The results of this are low pregnancy weight gain and IUGR, followed by LBW, with its associated greater risks of infection and higher perinatal mortality rates. For these reasons, in the setting of no large previous studies in Venezuela about this problem, a national multicentric study was conducted. Methods. Pregnant women from nine states were studied, a prenatal evaluation with a coproparasitological study. Univariated and multivariated analyses were made to determine risk factors for intestinal parasitosis and related anemia. Results. During 19 months, 1038 pregnant women were included and evaluated. Intestinal parasitosis was evidenced in 73.9%: A lumbricoides 57.0%, T trichiura 36.0%, G lamblia 14.1%, E hystolitica 12.0%, N americanus 8.1%, E vermicularis 6.3%, S stercoralis 3.3%. Relative risk for anemia in those women with intestinal parasitosis was 2.56 (P Intestinal parasitoses could be associated with conditions for development of anemia at pregnancy. These features reflect the need of routine coproparasitological study among pregnant women in rural and endemic zones for intestinal parasites. Further therapeutic and prophylactic protocols are needed. Additional research on pregnant intestinal parasitic infection impact on newborn health is also considered. PMID:17093349

Intestinal Colonization Dynamics of Vibrio cholerae.

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Salvador Almagro-Moreno

2015-05-01

Full Text Available To cause the diarrheal disease cholera, Vibrio cholerae must effectively colonize the small intestine. In order to do so, the bacterium needs to successfully travel through the stomach and withstand the presence of agents such as bile and antimicrobial peptides in the intestinal lumen and mucus. The bacterial cells penetrate the viscous mucus layer covering the epithelium and attach and proliferate on its surface. In this review, we discuss recent developments and known aspects of the early stages of V. cholerae intestinal colonization and highlight areas that remain to be fully understood. We propose mechanisms and postulate a model that covers some of the steps that are required in order for the bacterium to efficiently colonize the human host. A deeper understanding of the colonization dynamics of V. cholerae and other intestinal pathogens will provide us with a variety of novel targets and strategies to avoid the diseases caused by these organisms.

Intestinal Iron Homeostasis and Colon Tumorigenesis

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Yatrik M. Shah

2013-06-01

Full Text Available Colorectal cancer (CRC is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.

Avaliação do desempenho visual da lente intraocular difrativa multifocal - Zeiss AT Lisa 809 MTM

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Lucas Monferrari Monteiro Vianna

2014-04-01

Full Text Available Objetivo: Avaliar a função visual dos pacientes com implante bilateral da LIO multifocal difrativa AT-Lisa 809 MTM por meio dos exames de acuidade visual com e sem correção óptica, curva de sensibilidade ao contraste, curva de desfoco e questionário de qualidade de função visual (VQF39. Métodos: Estudo clínico, prospectivo e de intervenção, que avaliou os resultados de 20 olhos de 10 pacientes, submetidos à facoemulsificação e implante de LIO, entre fevereiro e junho de 2012. Resultados: A ametropia residual média pós-operatória foi de 0,05 ± 0,42 (-0,75 a +1,25 D dioptrias esféricas e -0,30 ± 0,42 (0 a -1,25 D dioptrias cilíndricas. Na curva de desenfoque mono e binocular, a melhor acuidade visual média obtida com 0.00 D de desenfoque (AV de longe. O segundo pico foi obtido com desenfoque de -3,00 D, o que equivale à visão de perto a 33 cm. Entre esses picos, observamos uma perda de desempenho visual, com desenfoque de -2,00 D, que equivale a visão intermediária a 50 cm. A sensibilidade ao contraste foi similar aos relatados na literatura com este tipo de LIO, tanto com quanto sem ofuscamento, e é mostrada em gráficos. O questionário de função visual (VFQ-39 teve valor médio de 91,91 +- 6,82. Conclusão: A LIO multifocal difrativa AT-Lisa 809MTM (Carl Zeiss Meditec Company - Alemanha apresentou resultados condizentes com a literatura quando avaliada pelos exames de acuidade visual com e sem correção óptica, sensibilidade ao contraste, curva de desfoco e questionário de qualidade de função visual (VQF 39.

Does measurement of small intestinal diameter increase diagnostic accuracy of radiography in dogs with suspected intestinal obstruction?

Science.gov (United States)

Ciasca, Taízha C; David, Frederic H; Lamb, Christopher R

2013-01-01

The ratio between maximal small intestinal (SI) diameter and the height of the body of the fifth lumbar vertebra (L5) in radiographs has been reported as a diagnostic test in dogs with suspected intestinal obstruction. In order to assess the effect of the SI/L5 ratio on the accuracy of radiographic diagnosis of intestinal obstruction, lateral abdominal radiographs of 37 dogs with small intestinal obstruction and 48 nonobstructed dogs were mixed and examined independently by six observers who were unaware of the final diagnosis and who represented a range of experience. Observers first examined radiographs subjectively and stated the likelihood of obstruction (definitely not, probably not, equivocal, probably, definitely). Observers subsequently reexamined the radiographs, determined the SI/L5 ratio, and again stated the likelihood of obstruction. The most frequent cause of obstruction was foreign body (29/37, 78%). Dogs with SI obstruction had a significantly larger median SI/L5 ratio than nonobstructed dogs (P = 0.0002). Using an SI/L5 ratio of 1.7 for diagnosis of intestinal obstruction, sensitivity and specificity were 66%. Use of the SI/L5 ratio was not associated with increased accuracy of diagnosis for any observer, regardless of experience, hence this test may have no diagnostic impact. © 2013 Veterinary Radiology & Ultrasound.

[Intestinal volvulus. Case report and a literature review].

Science.gov (United States)

Santín-Rivero, Jorge; Núñez-García, Edgar; Aguirre-García, Manuel; Hagerman-Ruiz-Galindo, Gonzalo; de la Vega-González, Francisco; Moctezuma-Velasco, Carla Rubi

2015-01-01

Small bowel volvulus is a rare cause of intestinal obstruction in adult patients. This disease is more common in children and its aetiology and management is different to that in adults. A 30 year-old male with sarcoidosis presents with acute abdomen and clinical data of intestinal obstruction. Small bowel volvulus is diagnosed by a contrast abdominal tomography and an exploratory laparotomy is performed with devolvulation and no intestinal resection. In the days following surgery, he developed a recurrent small bowel volvulus, which was again managed with surgery, but without intestinal resection. Medical treatment for sarcoidosis was started, and with his clinical progress being satisfactory,he was discharged to home. Making an early and correct diagnosis of small bowel volvulus prevents large intestinal resections. Many surgical procedures have been described with a high rate of complications. Therefore, conservative surgical management (no intestinal resection) is recommended as the best treatment with the lowest morbidity and mortality rate. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Fitobezoar associado à endometriose intestinal: uma rara causa de obstrução intestinal Intestinal endemetriosis associated to phytobezoar: a rare of bowel obstruction

Directory of Open Access Journals (Sweden)

Carlos Roberto Amorim

2009-12-01

Full Text Available A endometriose intestinal é uma patologia benigna que afeta preferencialmente a porção retossigmóidea, sendo pouco frequente a localização em íleo terminal. Trata-se de um caso de uma paciente de 29 anos que foi admitida com dor abdominal difusa, náuseas e vômitos. Na propedêutica da obstrução intestinal a tomografia computadorizada revelou massa heterogênea em topografia ileocecal. Submetida a laparotomia exploradora onde foi feita a remoção de fibras vegetais mal digeridas aglomeradas em íleo terminal e ressecção de segmento íleoceco cólico devido a presença de estenose na válvula ileocecal. O exame anátomo patológico revelou endometriose intestinal e fitobezoar. A paciente evoluiu bem com alta no terceiro dia de pós operatório.Intestinal endometriosis is a benign pathology, it occurs most often on the rectosigmoid portion, and the finding isn`t very common on the terminal ileum. On this article the autors present a report from a 29 years old pacient, who had a difuse abdominal pain, nausea and vomiting. Computadorized tomography (CT showed a heterogeneous mass on the ileocaecal area . An exploratory laparotomy was performed , badly metabolized vegetable fibers were removed from the terminal ileum, and a surgical removal of the ileocaecal - colic portion was done, since there was a stenosis on that area. The anatomical-pathologic study showed intestinal endometriosis and phytobezoar The patient had a good follow up and got out the hospital on the third day after surgery.

Prematurity reduces functional adaptation to intestinal resection in piglets

DEFF Research Database (Denmark)

Aunsholt, Lise; Thymann, Thomas; Qvist, Niels

2015-01-01

Background: Necrotizing enterocolitis and congenital gastrointestinal malformations in infants often require intestinal resection, with a subsequent risk of short bowel syndrome (SBS). We hypothesized that immediate intestinal adaptation following resection of the distal intestine with placement ...

Picometer stable scan mechanism for gravitational wave detection in space: LISA PAAM

Science.gov (United States)

Pijnenburg, J. A. C. M.; Rijnveld, N.

2017-11-01

Detection and observation of gravitational waves requires extreme stability in the frequency range 0.03 mHz to 1 Hz. The Laser Interferometer Space Antenna (LISA) mission will attain this by creating a giant interferometer in space, based on free floating proof masses in three spacecrafts. Due to orbit evolution and time delay in the interferometer arms, the direction of transmitted light changes. To solve this problem, a picometer stable Point-Ahead Angle Mechanism (PAAM) was designed, realized and successfully tested. The PAAM concept is based on a rotatable mirror. The critical requirements are the contribution to the optical path length (less than 1.4 pm / rt Hz) and the angular jitter (less than 8 nrad / rt Hz). Extreme dimensional stability is achieved by manufacturing a monolithical Haberland hinge mechanism out of Ti6Al4V, through high precision wire erosion. Extreme thermal stability is realized by placing the thermal center on the surface of the mirror. Because of piezo actuator noise and leakage, the PAAM has to be controlled in closed-loop. To meet the requirements in the low frequencies, an active target capacitance-to-digital converter is used. Interferometric measurements with a triangular resonant cavity in vacuum proved that the PAAM meets the requirements.

Vasoactive intestinal peptide is a local mediator in a gut-brain neural axis activating intestinal gluconeogenesis.

Science.gov (United States)

De Vadder, F; Plessier, F; Gautier-Stein, A; Mithieux, G

2015-03-01

Intestinal gluconeogenesis (IGN) promotes metabolic benefits through activation of a gut-brain neural axis. However, the local mediator activating gluconeogenic genes in the enterocytes remains unknown. We show that (i) vasoactive intestinal peptide (VIP) signaling through VPAC1 receptor activates the intestinal glucose-6-phosphatase gene in vivo, (ii) the activation of IGN by propionate is counteracted by VPAC1 antagonism, and (iii) VIP-positive intrinsic neurons in the submucosal plexus are increased under the action of propionate. These data support the role of VIP as a local neuromodulator released by intrinsic enteric neurons and responsible for the induction of IGN through a VPAC1 receptor-dependent mechanism in enterocytes. © 2015 John Wiley & Sons Ltd.

Primary small intestinal volvulus after laparoscopic rectopexy for rectal prolapse.

Science.gov (United States)

Koizumi, Michihiro; Yamada, Takeshi; Shinji, Seiichi; Yokoyama, Yasuyuki; Takahashi, Goro; Hotta, Masahiro; Iwai, Takuma; Hara, Keisuke; Takeda, Kohki; Kan, Hayato; Takasaki, Hideaki; Ohta, Keiichiro; Uchida, Eiji

2018-02-01

Primary small intestinal volvulus is defined as torsion in the absence of congenital malrotation, band, or postoperative adhesions. Its occurrence as an early postoperative complication is rare. A 40-year-old woman presented with rectal prolapse, and laparoscopic rectopexy was uneventfully performed. She could not have food on the day after surgery. She started oral intake on postoperative day 3 but developed abdominal pain after the meal. Contrast-enhanced CT revealed torsion of the small intestinal mesentery. An emergent laparotomy showed small intestinal volvulus, without congenital malformation or intestinal adhesions. We diagnosed it as primary small intestinal volvulus. The strangulated intestine was resected, and reconstruction was performed. The patient recovered uneventfully after the second surgery. To the best of our knowledge, this is the first report of primary small intestinal volvulus occurring after rectopexy for rectal prolapse. Primary small intestinal volvulus could be a postoperative complication after laparoscopy. © 2018 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Intestinal actinomycosis: a case report

International Nuclear Information System (INIS)

Loureiro, C.M.; Labrunie, E.; Pannaim, V.L.N.; Santos, A.A.S. dos; Pereira, A.A.

1989-01-01

Intestinal actinomycosis: a case report. The authors describe a case of intestinal actinomycosis, which was manisfestated by abdominal mass and suggested, clinical and radiologically, a bowel carcinoma. They discuss the pathogenesis, and the clinical and radiological manisfestations of this disease, and its differential diagnosis. This is an infrequent disease which must be considered whenever suggestive clinical aspects are associated with a radiological ''malignant pattern'' of a bowel lesion. (author) [pt

Precision-cut intestinal slices as a culture system to analyze the infection of differentiated intestinal epithelial cells by avian influenza viruses.

Science.gov (United States)

Punyadarsaniya, Darsaniya; Winter, Christine; Mork, Ann-Kathrin; Amiri, Mahdi; Naim, Hassan Y; Rautenschlein, Silke; Herrler, Georg

2015-02-01

Many viruses infect and replicate in their host via the intestinal tract, e.g. many picornaviruses, several coronaviruses and avian influenza viruses of waterfowl. To analyze infection of enterocytes is a challenging task as culture systems for differentiated intestinal epithelial cells are not readily available and often have a life span that is too short for infection studies. Precision-cut intestinal slices (PCIS) from chicken embryos were prepared and shown that the epithelial cells lining the lumen of the intestine are viable for up to 4 days. Using lectin staining, it was demonstrated that α2,3-linked sialic acids, the preferred receptor determinants of avian influenza viruses, are present on the apical side of the epithelial cells. Furthermore, the epithelial cells (at the tips) of the villi were shown to be susceptible to infection by an avian influenza virus of the H9N2 subtype. This culture system will be useful to analyze virus infection of intestinal epithelial cells and it should be applicable also to the intestine of other species. Copyright © 2014 Elsevier B.V. All rights reserved.

Congenital intestinal lymphangiectasia. A case report

Directory of Open Access Journals (Sweden)

Georgios Mitsiakos

2017-12-01

Full Text Available Congenital intestinal lymphangiectasia, first described by Waldmann et al. in 1961, is a rare congenital malformation of the lymphatics, presented with generalized edema, hypoproteinemia and lymphopenia. Diagnosis is based on endoscopy findings and pathology.We present here a case of a male neonate, second child of an indigenous woman, delivered by caesarean section. Prenatally, multiple cystic abdominal masses were identified by ultrasound. The patient was treated successfully with enterectomy and anastomosis. Histopathology revealed primary intestinal lymphangiectasia with no features of malignancy.Intestinal lymphangiectasia is a rare pathology, which should be differentiated while exploring abdominal masses, hypoproteinemia and edema especially in neonates.

Coagulation of sheep intestinal and prefemoral lymph.

Science.gov (United States)

Hanley, C A; Johnston, M G; Nelson, W

1988-06-01

We have determined the most suitable method for the automated analysis of the clotting parameters in sheep intestinal and prefemoral lymph as defined by the Activated Partial Thromboplastin Times (APTT; measure of intrinsic coagulation pathway) and the Prothrombin Times (PT; measure of extrinsic coagulation pathway). As opposed to optical density systems, the use of a Fibro-System Fibrometer was found to provide the most consistent assessment of coagulation with the endpoint being the time to fibrin strand formation. We measured APTT in sheep intestinal and prefemoral lymph of 59.78 +/- 7.69 seconds and 51.03 +/- 10.49 seconds respectively. These values were more prolonged than those obtained from sheep blood plasma but only in the case of intestinal lymph were the differences significant (p less than 0.025). Human blood APTT values were significantly less than both sheep blood (p less than 0.05) and sheep intestinal (p less than 0.001) and prefemoral lymph (p less than 0.01). PT values were found to be 21.56 +/- 1.14 seconds in intestinal and 22.00 +/- 1.88 seconds in prefemoral lymph. These values were also significantly greater than those obtained from sheep blood (both p less than 0.001). Human blood PTs were significantly less than both sheep blood (p less than 0.001) and intestinal and prefemoral lymph (both p less than 0.001). Measurement of APTT and PT values in intestinal lymph and PT determinations in prefemoral lymph were not affected by storage in the refrigerator or freezer. There was some indication that APTT values in prefemoral samples were susceptible to storage artifacts; however, the differences in coagulation times were not significant.

Irf4-dependent CD103+CD11b+ dendritic cells and the intestinal microbiome regulate monocyte and macrophage activation and intestinal peristalsis in postoperative ileus

DEFF Research Database (Denmark)

Pohl, Judith Mira; Gutweiler, Sebastian; Thiebes, Stephanie

2017-01-01

and large intestinal POI suggested a potential role of the intestinal microbiota. Indeed, antibiotic treatment reduced iNOS levels and ameliorated POI. Conclusions: Our findings reveal that CD103+CD11b+ DCs and the intestinal microbiome are a prerequisite for the activation of intestinal monocytes...

Wnt, RSPO and Hippo Signalling in the Intestine and Intestinal Stem Cells.

Science.gov (United States)

Kriz, Vitezslav; Korinek, Vladimir

2018-01-08

In this review, we address aspects of Wnt, R-Spondin (RSPO) and Hippo signalling, in both healthy and transformed intestinal epithelium. In intestinal stem cells (ISCs), the Wnt pathway is essential for intestinal crypt formation and renewal, whereas RSPO-mediated signalling mainly affects ISC numbers. In human colorectal cancer (CRC), aberrant Wnt signalling is the driving mechanism initiating this type of neoplasia. The signalling role of the RSPO-binding transmembrane proteins, the leucine-rich-repeat-containing G-protein-coupled receptors (LGRs), is possibly more pleiotropic and not only limited to the enhancement of Wnt signalling. There is growing evidence for multiple crosstalk between Hippo and Wnt/β-catenin signalling. In the ON state, Hippo signalling results in serine/threonine phosphorylation of Yes-associated protein (YAP1) and tafazzin (TAZ), promoting formation of the β-catenin destruction complex. In contrast, YAP1 or TAZ dephosphorylation (and YAP1 methylation) results in β-catenin destruction complex deactivation and β-catenin nuclear localization. In the Hippo OFF state, YAP1 and TAZ are engaged with the nuclear β-catenin and participate in the β-catenin-dependent transcription program. Interestingly, YAP1/TAZ are dispensable for intestinal homeostasis; however, upon Wnt pathway hyperactivation, the proteins together with TEA domain (TEAD) transcription factors drive the transcriptional program essential for intestinal cell transformation. In addition, in many CRC cells, YAP1 phosphorylation by YES proto-oncogene 1 tyrosine kinase (YES1) leads to the formation of a transcriptional complex that includes YAP1, β-catenin and T-box 5 (TBX5) DNA-binding protein. YAP1/β-catenin/T-box 5-mediated transcription is necessary for CRC cell proliferation and survival. Interestingly, dishevelled (DVL) appears to be an important mediator involved in both Wnt and Hippo (YAP1/TAZ) signalling and some of the DVL functions were assigned to the nuclear DVL

Protective effect of salvianolic acid B against intestinal ischemia ...

African Journals Online (AJOL)

Conclusion: The results of this study demonstrate that SAB may protect the intestine by attenuating oxidative stress and inflammatory response and hence, may be potentially for treating IIRI. Keywords: Salvianolic acid B, Intestinal Ischemia-reperfusion, Antioxidants, Inflammation, Intestinal permeability ...

burden of intestinal parasites amongst hiv/aids patients attending

African Journals Online (AJOL)

boaz

ABSTRACT. Background: Intestinal parasitic infections cause severe diarrhea especially in debilitated subjects with clinical ... Regional Hospital, Entamoeba histolytica and other intestinal parasites represented a common burden. .... Attempt was made to go through all the fields of ..... Control of Intestinal parasite Infections.

Diversity and functions of intestinal mononuclear phagocytes

DEFF Research Database (Denmark)

Joeris, Thorsten; Müller-Luda, K; Agace, William Winston

2017-01-01

The intestinal lamina propria (LP) contains a diverse array of mononuclear phagocyte (MNP) subsets, including conventional dendritic cells (cDC), monocytes and tissue-resident macrophages (mφ) that collectively play an essential role in mucosal homeostasis, infection and inflammation. In the curr......The intestinal lamina propria (LP) contains a diverse array of mononuclear phagocyte (MNP) subsets, including conventional dendritic cells (cDC), monocytes and tissue-resident macrophages (mφ) that collectively play an essential role in mucosal homeostasis, infection and inflammation....... In the current review we discuss the function of intestinal cDC and monocyte-derived MNP, highlighting how these subsets play several non-redundant roles in the regulation of intestinal immune responses. While much remains to be learnt, recent findings also underline how the various populations of MNP adapt...

Flavanol-Enriched Cocoa Powder Alters the Intestinal Microbiota, Tissue and Fluid Metabolite Profiles, and Intestinal Gene Expression in Pigs.

Science.gov (United States)

Jang, Saebyeol; Sun, Jianghao; Chen, Pei; Lakshman, Sukla; Molokin, Aleksey; Harnly, James M; Vinyard, Bryan T; Urban, Joseph F; Davis, Cindy D; Solano-Aguilar, Gloria

2016-04-01

Consumption of cocoa-derived polyphenols has been associated with several health benefits; however, their effects on the intestinal microbiome and related features of host intestinal health are not adequately understood. The objective of this study was to determine the effects of eating flavanol-enriched cocoa powder on the composition of the gut microbiota, tissue metabolite profiles, and intestinal immune status. Male pigs (5 mo old, 28 kg mean body weight) were supplemented with 0, 2.5, 10, or 20 g flavanol-enriched cocoa powder/d for 27 d. Metabolites in serum, urine, the proximal colon contents, liver, and adipose tissue; bacterial abundance in the intestinal contents and feces; and intestinal tissue gene expression of inflammatory markers and Toll-like receptors (TLRs) were then determined. O-methyl-epicatechin-glucuronide conjugates dose-dependently increased (Pcocoa powder. The concentration of 3-hydroxyphenylpropionic acid isomers in urine decreased as the dose of cocoa powder fed to pigs increased (75-85%,Pcocoa powder/d, respectively. Moreover, consumption of cocoa powder reducedTLR9gene expression in ileal Peyer's patches (67-80%,Pcocoa powder/d compared with pigs not supplemented with cocoa powder. This study demonstrates that consumption of cocoa powder by pigs can contribute to gut health by enhancing the abundance ofLactobacillusandBifidobacteriumspecies and modulating markers of localized intestinal immunity. © 2016 American Society for Nutrition.

[Intestinal intussusception due to ileal gastrointestinal stromal tumor--a case report].

Science.gov (United States)

Andrei, S; Andrei, A; Tonea, A; Andronesi, D; Preda, C; Herlea, V; Popescu, I

2011-01-01

Intestinal occlusion due to intussusception produced by intestinal tumors is a very rare condition. Gastrointestinal stromal tumors are also rare digestive neopasias, with an impredictable malignant behavior, which are usually growing outside the intestinal wall, being rarely the initiators of an intestinal intussusception. We present the case of a 59 years old female, admitted in our hospital to elucidate the etiology of her iron deficient anaemia, which developed an intestinal occlusion at the intestinal preparation for colonoscopy. The abdominal CT scan performed in emergency conditions highlighted occlusive intestinal tumor complicated with intestinal intussusception. We performed an emergency laparotomy that revealed intestinal occlusion due to ileo-ileal intussusception produced by an ileal tumor. The surgical intervention consisted in segmental ileal enterectomy including the tumor with latero-lateral entero-enteral anastomosis. The patient recovered without complications. The histopathological and immunohisto-chemical examinations established the diagnose of gastro-intestinal stromal tumor with high risk malignant behavior, therefore the patient was guided in the oncological department for specific treatment and oncological surveillance.

Accumulative effect of food residues on intestinal gas production.

Science.gov (United States)

Mego, M; Accarino, A; Malagelada, J-R; Guarner, F; Azpiroz, F

2015-11-01

As mean transit time in the colon is longer than the interval between meals, several consecutive meal loads accumulate, and contribute to colonic biomass. Our aim was to determine the summation effect of fermentable food residues on intestinal gas production. In eight healthy subjects, the volume of endogenous intestinal gas produced in the intestine over a 4-h period was measured by means of a wash-out technique, using an exogenous gas infusion into the jejunum (24 mL/min) and collection of the effluent via a rectal Foley catheter. The exogenous gas infused was labeled (5% SF6 ) to calculate the proportion of endogenous intestinal gas evacuated. In each subject, four experiments were performed ≥1 week apart combining a 1-day high- or low-flatulogenic diet with a test meal or fast. Basal conditions: on the low-flatulogenic diet, intestinal gas production during fasting over the 4-h study period was 609 ± 63 mL. Effect of diet: during fasting, intestinal gas production on the high-flatulogenic diet was 370 ± 146 mL greater than on the low-flatulogenic diet (p = 0.040). Effect of test meal: on the low-flatulogenic diet, intestinal gas production after the test meal was 681 ± 114 mL greater than during fasting (p = 0.001); a similar effect was observed on the high-flatulogenic diet (599 ± 174 mL more intestinal gas production after the test meal than during fasting; p = 0.021). Our data demonstrate temporal summation effects of food residues on intestinal gas production. Hence, intestinal gas production depends on pre-existing and on recent colonic loads of fermentable foodstuffs. © 2015 John Wiley & Sons Ltd.

The Gut-Associated Lymphoid Tissues in the Small Intestine, Not the Large Intestine, Play a Major Role in Oral Prion Disease Pathogenesis

Science.gov (United States)

Donaldson, David S.; Else, Kathryn J.

2015-01-01

ABSTRACT Prion diseases are infectious neurodegenerative disorders characterized by accumulations of abnormally folded cellular prion protein in affected tissues. Many natural prion diseases are acquired orally, and following exposure, the early replication of some prion isolates upon follicular dendritic cells (FDC) within gut-associated lymphoid tissues (GALT) is important for the efficient spread of disease to the brain (neuroinvasion). Prion detection within large intestinal GALT biopsy specimens has been used to estimate human and animal disease prevalence. However, the relative contributions of the small and large intestinal GALT to oral prion pathogenesis were unknown. To address this issue, we created mice that specifically lacked FDC-containing GALT only in the small intestine. Our data show that oral prion disease susceptibility was dramatically reduced in mice lacking small intestinal GALT. Although these mice had FDC-containing GALT throughout their large intestines, these tissues were not early sites of prion accumulation or neuroinvasion. We also determined whether pathology specifically within the large intestine might influence prion pathogenesis. Congruent infection with the nematode parasite Trichuris muris in the large intestine around the time of oral prion exposure did not affect disease pathogenesis. Together, these data demonstrate that the small intestinal GALT are the major early sites of prion accumulation and neuroinvasion after oral exposure. This has important implications for our understanding of the factors that influence the risk of infection and the preclinical diagnosis of disease. IMPORTANCE Many natural prion diseases are acquired orally. After exposure, the accumulation of some prion diseases in the gut-associated lymphoid tissues (GALT) is important for efficient spread of disease to the brain. However, the relative contributions of GALT in the small and large intestines to oral prion pathogenesis were unknown. We show that the

The Gut-Associated Lymphoid Tissues in the Small Intestine, Not the Large Intestine, Play a Major Role in Oral Prion Disease Pathogenesis.

Science.gov (United States)

Donaldson, David S; Else, Kathryn J; Mabbott, Neil A

2015-09-01

Prion diseases are infectious neurodegenerative disorders characterized by accumulations of abnormally folded cellular prion protein in affected tissues. Many natural prion diseases are acquired orally, and following exposure, the early replication of some prion isolates upon follicular dendritic cells (FDC) within gut-associated lymphoid tissues (GALT) is important for the efficient spread of disease to the brain (neuroinvasion). Prion detection within large intestinal GALT biopsy specimens has been used to estimate human and animal disease prevalence. However, the relative contributions of the small and large intestinal GALT to oral prion pathogenesis were unknown. To address this issue, we created mice that specifically lacked FDC-containing GALT only in the small intestine. Our data show that oral prion disease susceptibility was dramatically reduced in mice lacking small intestinal GALT. Although these mice had FDC-containing GALT throughout their large intestines, these tissues were not early sites of prion accumulation or neuroinvasion. We also determined whether pathology specifically within the large intestine might influence prion pathogenesis. Congruent infection with the nematode parasite Trichuris muris in the large intestine around the time of oral prion exposure did not affect disease pathogenesis. Together, these data demonstrate that the small intestinal GALT are the major early sites of prion accumulation and neuroinvasion after oral exposure. This has important implications for our understanding of the factors that influence the risk of infection and the preclinical diagnosis of disease. Many natural prion diseases are acquired orally. After exposure, the accumulation of some prion diseases in the gut-associated lymphoid tissues (GALT) is important for efficient spread of disease to the brain. However, the relative contributions of GALT in the small and large intestines to oral prion pathogenesis were unknown. We show that the small intestinal

Advanced three-dimensional culture of equine intestinal epithelial stem cells.

Science.gov (United States)

Stewart, A Stieler; Freund, J M; Gonzalez, L M

2018-03-01

Intestinal epithelial stem cells are critical to epithelial repair following gastrointestinal injury. The culture of intestinal stem cells has quickly become a cornerstone of a vast number of new research endeavours that range from determining tissue viability to testing drug efficacy for humans. This study aims to describe the methods of equine stem cell culture and highlights the future benefits of these techniques for the advancement of equine medicine. To describe the isolation and culture of small intestinal stem cells into three-dimensional (3D) enteroids in horses without clinical gastrointestinal abnormalities. Descriptive study. Intestinal samples were collected by sharp dissection immediately after euthanasia. Intestinal crypts containing intestinal stem cells were dissociated from the underlying tissue layers, plated in a 3D matrix and supplemented with growth factors. After several days, resultant 3D enteroids were prepared for immunofluorescent imaging and polymerase chain reaction (PCR) analysis to detect and characterise specific cell types present. Intestinal crypts were cryopreserved immediately following collection and viability assessed. Intestinal crypts were successfully cultured and matured into 3D enteroids containing a lumen and budding structures. Immunofluorescence and PCR were used to confirm the existence of stem cells and all post mitotic, mature cell types, described to exist in the horse intestinal epithelium. Previously frozen crypts were successfully cultured following a freeze-thaw cycle. Tissues were all derived from normal horses. Application of this technique for the study of specific disease was not performed at this time. The successful culture of equine intestinal crypts into 3D "mini-guts" allows for in vitro studies of the equine intestine. Additionally, these results have relevance to future development of novel therapies that harness the regenerative potential of equine intestine in horses with gastrointestinal disease

Diseño de un plan de marketing para el producto lisa college desarrollado por la microempresa browse Ecuador, ubicada en la ciudad de Quito.

OpenAIRE

Coello Duque, Giomar Evelyn

2013-01-01

The present work aims to make a marketing plan for the product developed by Lisa College microenterprise Browse Ecuador Cia. Ltd. and it will be a guide for other micros companies wishing to conduct similar research. First, we review general information about the company under study in order to identify problems, research objectives and delimitation of the research area. With this knowledge provides the theoretical and conceptual framework underpinning this research. The ...

Microfluidic Organ-on-a-Chip Models of Human IntestineSummary

Directory of Open Access Journals (Sweden)

Amir Bein

Full Text Available Microfluidic organ-on-a-chip models of human intestine have been developed and used to study intestinal physiology and pathophysiology. In this article, we review this field and describe how microfluidic Intestine Chips offer new capabilities not possible with conventional culture systems or organoid cultures, including the ability to analyze contributions of individual cellular, chemical, and physical control parameters one-at-a-time; to coculture human intestinal cells with commensal microbiome for extended times; and to create human-relevant disease models. We also discuss potential future applications of human Intestine Chips, including how they might be used for drug development and personalized medicine. Keywords: Organs-on-Chips, Gut-on-a-Chip, Intestine-on-a-Chip, Microfluidic

Intramural intestinal hematoma causing obstruction in three dogs.

Science.gov (United States)

Moore, R; Carpenter, J

1984-01-15

Intramural hematoma of the intestine caused intestinal obstruction in three dogs. Two dogs were examined because of vomiting and anorexia of several weeks' duration. In one of these, an intramural hematoma of the duodenum was associated with chronic pancreatitis. A cause was not found in the second dog. The third dog, which had clinical and radiographic evidence of gastric dilatation, was found at surgery to have hemoperitoneum associated with a ruptured intramural intestinal hematoma. In 1 dog, the hematoma was evacuated through a serosal incision. In the other 2 dogs, the problem was resolved by resection of the involved segment of intestine, followed by anastomosis. All 3 dogs recovered without complications.

Temporary intestinal ischemia for radiation protection

International Nuclear Information System (INIS)

Lote, K.

1983-01-01

The most important determinant of cellular radiosensivity is the tissue oxygen content at the time of irradiation. The purpose of the present experimental work was to assess a new iscemia-inducing method in order to reduce normal tissue radiation damage during radiotherapy. Temporary ischemia was induced in a cat small intestine by degraded starch microspheres. Regional arterial and tissue blod flow immediately fell by 85% with subsequent normalization within 26 minutes after microsphere injection. No tendency of small vessel thrombosis caused by starch sphere embolization in combination with previous or current intestinal irradiation was detected. Starch sphere remenants were rapidly engulfed by, and persisted within tissue macrophages for 14 days without causing intestinal inflammatory reactions. In vitro studies showed that human platelets neither adhered to nor were aggregated by starch microspheres. The new method, wich occlude arteriolar vessels distal to the mesentric arterial arcades and thus largely excludes collateral blood flow, seems suited to provide effictive and selective feline small intestinal hypoxic radiation protection. This conclusion may also be valid in man

Intestinal perforation by an ingested foreign body*

Science.gov (United States)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F. S.; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

Objective To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. PMID:27818542

Intestinal perforation by an ingested foreign body

International Nuclear Information System (INIS)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

Intestinal perforation by an ingested foreign body.

Science.gov (United States)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F S; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

Intestinal perforation by an ingested foreign body

Energy Technology Data Exchange (ETDEWEB)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle, E-mail: gabrielnicolodi@gmail.com [Hospital Sao Vicente - Funef, Curitiba, PR (Brazil)

2016-09-15

Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

Intestinal perforation by an ingested foreign body

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Gabriel Cleve Nicolodi

Full Text Available Abstract Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases, increased density of mesenteric fat (in all four cases, identification of the foreign body passing through the intestinal wall (in three cases, and gas in the peritoneal cavity (in one case. Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

Vasoactive intestinal polypeptide and other preprovasoactive intestinal polypeptide-derived peptides in the female and male genital tract: localization, biosynthesis, and functional and clinical significance

DEFF Research Database (Denmark)

Ottesen, B; Fahrenkrug, J

1995-01-01

Vasoactive intestinal polypeptide, a neuropeptide with wide distribution in the central and peripheral nervous system, has a broad spectrum of biologic actions. The demonstration of vasoactive intestinal polypeptide containing nerve fibers within the female and male genital tract 17 years ago...... indicated a putative role for this peptide in the local nervous control of reproductive functions. The genes encoding the preprovasoactive intestinal polypeptide precursor molecule and the vasoactive intestinal polypeptide receptor have been identified. The gene expression has been studied by the use...... in the genital tracts (i.e., blood flow and nonvascular smooth muscle relaxation). In the ovary vasoactive intestinal polypeptide seems to play an important role as regulator and/or modulator of folliculogenesis and steroidogenesis. In the male genital tract vasoactive intestinal polypeptide seems to participate...

The Brain–Intestinal Mucosa–Appendix– Microbiome–Brain Loop

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Luis Vitetta

2018-04-01

Full Text Available The brain and the gut are connected from early fetal life. The mother’s exposure to microbial molecules is thought to exert in utero developmental effects on the fetus. These effects could importantly underpin the groundwork for subsequent pathophysiological mechanisms for achieving immunological tolerance and metabolic equilibrium post birth, events that continue through to 3–4 years of age. Furthermore, it is understood that the microbiome promotes cues that instruct the neonate’s mucosal tissues and skin in the language of molecular and cellular biology. Post birth mucosal lymphoid tissue formation and maturation (most probably including the vermiform appendix is microbiota-encouraged co-establishing the intestinal microbiome with a developing immune system. Intestinal mucosal tissue maturation loops the brain-gut-brain and is postulated to influence mood dispositions via shifts in the intestinal microbiome phyla. A plausible appreciation is that dysregulated pro-inflammatory signals from intestinal resident macrophages could breach the loop by providing adverse mood signals via vagus nerve afferents to the brain. In this commentary, we further suggest that the intestinal resident macrophages act as an upstream traffic controller of translocated microbes and metabolites in order to maintain local neuro-endocrine-immunological equilibrium. When macrophages are overwhelmed through intestinal microbiome and intestinal epithelial cell dysbiosis, pro-inflammatory signals are sustained, which may then lead to mood disorders. The administration of probiotics as an adjunctive medicine co-administered with antidepressant medications in improving depressed mood may have biological and clinical standing.

Neural influences on human intestinal epithelium in vitro.

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Krueger, Dagmar; Michel, Klaus; Zeller, Florian; Demir, Ihsan E; Ceyhan, Güralp O; Slotta-Huspenina, Julia; Schemann, Michael

2016-01-15

We present the first systematic and, up to now, most comprehensive evaluation of the basic features of epithelial functions, such as basal and nerve-evoked secretion, as well as tissue resistance, in over 2200 surgical specimens of human small and large intestine. We found no evidence for impaired nerve-evoked epithelial secretion or tissue resistance with age or disease pathologies (stomach, pancreas or colon cancer, polyps, diverticulitis, stoma reversal). This indicates the validity of future studies on epithelial secretion or resistance that are based on data from a variety of surgical specimens. ACh mainly mediated nerve-evoked and basal secretion in the small intestine, whereas vasoactive intestinal peptide and nitric oxide were the primary pro-secretory transmitters in the large intestine. The results of the present study revealed novel insights into regional differences in nerve-mediated secretion in the human intestine and comprise the basis by which to more specifically target impaired epithelial functions in the diseased gut. Knowledge on basic features of epithelial functions in the human intestine is scarce. We used Ussing chamber techniques to record basal tissue resistance (R-basal) and short circuit currents (ISC; secretion) under basal conditions (ISC-basal) and after electrical field stimulation (ISC-EFS) of nerves in 2221 resectates from 435 patients. ISC-EFS was TTX-sensitive and of comparable magnitude in the small and large intestine. ISC-EFS or R-basal were not influenced by the patients' age, sex or disease pathologies (cancer, polyps, diverticulitis). Ion substitution, bumetanide or adenylate cyclase inhibition studies suggested that ISC-EFS depended on epithelial cAMP-driven chloride and bicarbonate secretion but not on amiloride-sensitive sodium absorption. Although atropine-sensitive cholinergic components prevailed for ISC-EFS of the duodenum, jejunum and ileum, PG97-269-sensitive [vasoactive intestinal peptide (VIP) receptor 1

Intestinal endocrine cells in radiation enteritis

International Nuclear Information System (INIS)

Pietroletti, R.; Blaauwgeers, J.L.; Taat, C.W.; Simi, M.; Brummelkamp, W.H.; Becker, A.E.

1989-01-01

In this study, the intestinal endocrine cells were investigated in 13 surgical specimens affected by radiation enteritis. Endocrine cells were studied by means of Grimelius' silver staining and immunostaining for chromogranin, a general marker of endocrine cells. Positively stained cells were quantified by counting their number per unit length of muscularis mucosa. Results in radiation enteritis were compared with matched control specimens by using Student's t test. Chromogranin immunostaining showed a statistically significant increase of endocrine cells in radiation enteritis specimens compared with controls both in small and large intestine (ileum, 67.5 +/- 23.5 cells per unit length of muscularis mucosa in radiation enteritis versus 17.0 +/- 6.1 in controls; colon, 40.9 +/- 13.7 cells per unit length of muscularis mucosa in radiation enteritis versus 9.5 +/- 4.1 in controls--p less than 0.005 in both instances). Increase of endocrine cells was demonstrated also by Grimelius' staining; however, without reaching statistical significance. It is not clear whether or not the increase of endocrine cells in radiation enteritis reported in this study is caused by a hyperplastic response or by a sparing phenomenon. We should consider that increased endocrine cells, when abnormally secreting their products, may be involved in some of the clinical features of radiation enteropathy. In addition, as intestinal endocrine cells produce trophic substances to the intestine, their increase could be responsible for the raised risk of developing carcinoma of the intestine in long standing radiation enteritis

Regulation of intestinal protein metabolism by amino acids.

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Bertrand, Julien; Goichon, Alexis; Déchelotte, Pierre; Coëffier, Moïse

2013-09-01

Gut homeostasis plays a major role in health and may be regulated by quantitative and qualitative food intake. In the intestinal mucosa, an intense renewal of proteins occurs, at approximately 50% per day in humans. In some pathophysiological conditions, protein turnover is altered and may contribute to intestinal or systemic diseases. Amino acids are key effectors of gut protein turnover, both as constituents of proteins and as regulatory molecules limiting intestinal injury and maintaining intestinal functions. Many studies have focused on two amino acids: glutamine, known as the preferential substrate of rapidly dividing cells, and arginine, another conditionally essential amino acid. The effects of glutamine and arginine on protein synthesis appear to be model and condition dependent, as are the involved signaling pathways. The regulation of gut protein degradation by amino acids has been minimally documented until now. This review will examine recent data, helping to better understand how amino acids regulate intestinal protein metabolism, and will explore perspectives for future studies.

Ultrasonographic findings of intestinal intussusception in seven cats.

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Patsikas, M N; Papazoglou, L G; Papaioannou, N G; Savvas, I; Kazakos, G M; Dessiris, A K

2003-12-01

The medical records of seven cats with intestinal intussusception that were diagnosed by abdominal ultrasonography and exploratory laparotomy were reviewed. In transverse ultrasonographic sections the intussusception appeared as a target-like mass consisting of one, two or more hyperechoic and hypoechoic concentric rings surrounding a C-shaped, circular or non-specific shaped hyperechoic centre. Part of the intestine representing the inner intussusceptum, located close to the hyperechoic centre and surrounded by concentric rings, was also detected. In longitudinal sections the intussusception appeared as multiple hyperechoic and hypoechoic parallel lines in four cases and as an ovoid mass in three cases. In one case the ovoid mass had a 'kidney' configuration. Additional ultrasonographic findings associated with intestinal intussusception included an intestinal neoplasm in one cat. The results of the present study demonstrate that the ultrasonographic findings of intestinal intussusception in cats bear some similarities to those described in dogs and humans, are relatively consistent, and facilitate a specific diagnosis.

Bovine lactoferrin regulates cell survival, apoptosis and inflammation in intestinal epithelial cells and preterm pig intestine.

Science.gov (United States)

Nguyen, Duc Ninh; Jiang, Pingping; Stensballe, Allan; Bendixen, Emøke; Sangild, Per T; Chatterton, Dereck E W

2016-04-29

Bovine lactoferrin (bLF) may modulate neonatal intestinal inflammation. Previous studies in intestinal epithelial cells (IECs) indicated that moderate bLF doses enhance proliferation whereas high doses trigger inflammation. To further elucidate cellular mechanisms, we profiled the porcine IEC proteome after stimulation with bLF at 0, 0.1, 1 and 10g/L by LC-MS-based proteomics. Key pathways were analyzed in the intestine of formula-fed preterm pigs with and without supplementation of 10g/L bLF. Levels of 123 IEC proteins were altered by bLF. Low bLF doses (0.1-1g/L) up-regulated 11 proteins associated with glycolysis, energy metabolism and protein synthesis, indicating support of cell survival. In contrast, a high bLF dose (10g/L) up-regulated three apoptosis-inducing proteins, down-regulated five anti-apoptotic and proliferation-inducing proteins and 15 proteins related to energy and amino acid metabolism, and altered three proteins enhancing the hypoxia inducible factor-1 (HIF-1) pathway. In the preterm pig intestine, bLF at 10g/L decreased villus height/crypt depth ratio and up-regulated the Bax/Bcl-2 ratio and HIF-1α, indicating elevated intestinal apoptosis and inflammation. In conclusion, bLF dose-dependently affects IECs via metabolic, apoptotic and inflammatory pathways. It is important to select an appropriate dose when feeding neonates with bLF to avoid detrimental effects exerted by excessive doses. The present work elucidates dose-dependent effects of bLF on the proteomic changes of IECs in vitro supplemented with data from a preterm pig study confirming detrimental effects of enteral feeding with the highest dose of bLF (10g/L). The study contributes to further understanding on mechanisms that bLF, as an important milk protein, can regulate the homeostasis of the immature intestine. Results from this study urge neonatologists to carefully consider the dose of bLF to supplement into infant formula used for preterm neonates. Copyright © 2016 Elsevier B

HDAC1 and HDAC2 restrain the intestinal inflammatory response by regulating intestinal epithelial cell differentiation.

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Naomie Turgeon

Full Text Available Acetylation and deacetylation of histones and other proteins depends on histone acetyltransferases and histone deacetylases (HDACs activities, leading to either positive or negative gene expression. HDAC inhibitors have uncovered a role for HDACs in proliferation, apoptosis and inflammation. However, little is known of the roles of specific HDACs in intestinal epithelial cells (IEC. We investigated the consequences of ablating both HDAC1 and HDAC2 in murine IECs. Floxed Hdac1 and Hdac2 homozygous mice were crossed with villin-Cre mice. Mice deficient in both IEC HDAC1 and HDAC2 weighed less and survived more than a year. Colon and small intestinal sections were stained with hematoxylin and eosin, or with Alcian blue and Periodic Acid Schiff for goblet cell identification. Tissue sections from mice injected with BrdU for 2 h, 14 h and 48 h were stained with anti-BrdU. To determine intestinal permeability, 4-kDa FITC-labeled dextran was given by gavage for 3 h. Microarray analysis was performed on total colon RNAs. Inflammatory and IEC-specific gene expression was assessed by Western blot or semi-quantitative RT-PCR and qPCR with respectively total colon protein and total colon RNAs. HDAC1 and HDAC2-deficient mice displayed: 1 increased migration and proliferation, with elevated cyclin D1 expression and phosphorylated S6 ribosomal protein, a downstream mTOR target; 2 tissue architecture defects with cell differentiation alterations, correlating with reduction of secretory Paneth and goblet cells in jejunum and goblet cells in colon, increased expression of enterocytic markers such as sucrase-isomaltase in the colon, increased expression of cleaved Notch1 and augmented intestinal permeability; 3 loss of tissue homeostasis, as evidenced by modifications of claudin 3 expression, caspase-3 cleavage and Stat3 phosphorylation; 4 chronic inflammation, as determined by inflammatory molecular expression signatures and altered inflammatory gene expression

Sand impaction of the small intestine in eight dogs.

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Moles, A D; McGhite, A; Schaaf, O R; Read, R

2010-01-01

To describe signalment, clinical findings, imaging and treatment of intestinal sand impaction in the dog. Medical records of dogs with radiographic evidence of small intestinal sand impaction were reviewed. Sand impaction resulting in small intestinal obstruction was diagnosed in eight dogs. All dogs presented with signs of vomiting. Other clinical signs included anorexia, lethargy and abdominal pain. Radiographs confirmed the presence of radio-opaque material consistent with sand causing distension of the terminal small intestine in all dogs. Four dogs were treated surgically for their impaction and four dogs were managed medically. Seven of the eight dogs survived. Both medical and surgical management of intestinal sand impaction in the dog can be effective and both afford a good prognosis for recovery.

A deconvolution technique for processing small intestinal transit data

Energy Technology Data Exchange (ETDEWEB)

Brinch, K. [Department of Clinical Physiology and Nuclear Medicine, Glostrup Hospital, University Hospital of Copenhagen (Denmark); Larsson, H.B.W. [Danish Research Center of Magnetic Resonance, Hvidovre Hospital, University Hospital of Copenhagen (Denmark); Madsen, J.L. [Department of Clinical Physiology and Nuclear Medicine, Hvidovre Hospital, University Hospital of Copenhagen (Denmark)

1999-03-01

The deconvolution technique can be used to compute small intestinal impulse response curves from scintigraphic data. Previously suggested approaches, however, are sensitive to noise from the data. We investigated whether deconvolution based on a new simple iterative convolving technique can be recommended. Eight healthy volunteers ingested a meal that contained indium-111 diethylene triamine penta-acetic acid labelled water and technetium-99m stannous colloid labelled omelette. Imaging was performed at 30-min intervals until all radioactivity was located in the colon. A Fermi function=(1+e{sup -{alpha}{beta}})/(1+e{sup (t-{alpha}){beta}}) was chosen to characterize the small intestinal impulse response function. By changing only two parameters, {alpha} and {beta}, it is possible to obtain configurations from nearly a square function to nearly a monoexponential function. Small intestinal input function was obtained from the gastric emptying curve and convolved with the Fermi function. The sum of least squares was used to find {alpha} and {beta} yielding the best fit of the convolved curve to the oberved small intestinal time-activity curve. Finally, a small intestinal mean transit time was calculated from the Fermi function referred to. In all cases, we found an excellent fit of the convolved curve to the observed small intestinal time-activity curve, that is the Fermi function reflected the small intestinal impulse response curve. Small intestinal mean transit time of liquid marker (median 2.02 h) was significantly shorter than that of solid marker (median 2.99 h; P<0.02). The iterative convolving technique seems to be an attractive alternative to ordinary approaches for the processing of small intestinal transit data. (orig.) With 2 figs., 13 refs.

Interactions Between Diet and the Intestinal Microbiota Alter Intestinal Permeability and Colitis Severity in Mice.

Science.gov (United States)

Llewellyn, Sean R; Britton, Graham J; Contijoch, Eduardo J; Vennaro, Olivia H; Mortha, Arthur; Colombel, Jean-Frederic; Grinspan, Ari; Clemente, Jose C; Merad, Miriam; Faith, Jeremiah J

2018-03-01

It is not clear how the complex interactions between diet and the intestinal microbiota affect development of mucosal inflammation or inflammatory bowel disease. We investigated interactions between dietary ingredients, nutrients, and the microbiota in specific pathogen-free (SPF) and germ-free (GF) mice given more than 40 unique diets; we quantified individual and synergistic effects of dietary macronutrients and the microbiota on intestinal health and development of colitis. C56BL/6J SPF and GF mice were placed on custom diets containing different concentrations and sources of protein, fat, digestible carbohydrates, and indigestible carbohydrates (fiber). After 1 week, SPF and GF mice were given dextran sulfate sodium (DSS) to induce colitis. Disease severity was determined based on the percent weight change from baseline, and modeled as a function of the concentration of each macronutrient in the diet. In unchallenged mice, we measured intestinal permeability by feeding mice labeled dextran and measuring levels in blood. Feces were collected and microbiota were analyzed by 16S rDNA sequencing. We collected colons from mice and performed transcriptome analyses. Fecal microbiota varied with diet; the concentration of protein and fiber had the strongest effect on colitis development. Among 9 fiber sources tested, psyllium, pectin, and cellulose fiber reduced the severity of colitis in SPF mice, whereas methylcellulose increased severity. Increasing dietary protein increased the density of the fecal microbiota and the severity of colitis in SPF mice, but not in GF mice or mice given antibiotics. Psyllium fiber reduced the severity of colitis through microbiota-dependent and microbiota-independent mechanisms. Combinatorial perturbations to dietary casein protein and psyllium fiber in parallel accounted for most variation in gut microbial density and intestinal permeability in unchallenged mice, as well as the severity of DSS-induced colitis; changes in 1 ingredient

Circadian disorganization alters intestinal microbiota.

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Robin M Voigt

Full Text Available Intestinal dysbiosis and circadian rhythm disruption are associated with similar diseases including obesity, metabolic syndrome, and inflammatory bowel disease. Despite the overlap, the potential relationship between circadian disorganization and dysbiosis is unknown; thus, in the present study, a model of chronic circadian disruption was used to determine the impact on the intestinal microbiome. Male C57BL/6J mice underwent once weekly phase reversals of the light:dark cycle (i.e., circadian rhythm disrupted mice to determine the impact of circadian rhythm disruption on the intestinal microbiome and were fed either standard chow or a high-fat, high-sugar diet to determine how diet influences circadian disruption-induced effects on the microbiome. Weekly phase reversals of the light:dark (LD cycle did not alter the microbiome in mice fed standard chow; however, mice fed a high-fat, high-sugar diet in conjunction with phase shifts in the light:dark cycle had significantly altered microbiota. While it is yet to be established if some of the adverse effects associated with circadian disorganization in humans (e.g., shift workers, travelers moving across time zones, and in individuals with social jet lag are mediated by dysbiosis, the current study demonstrates that circadian disorganization can impact the intestinal microbiota which may have implications for inflammatory diseases.

Laparoscopic Treatment of Intestinal Malrotation in Children

NARCIS (Netherlands)

Ooms, N.; Matthyssens, L.E.; Draaisma, J.M.T.; Blaauw, I. de; Wijnen, M.H.

2016-01-01

Purpose Intestinal malrotation is a congenital intestinal rotation anomaly, which can be treated by either laparotomy or laparoscopy. Our hypothesis is that laparoscopic treatment leads to less small bowel obstruction because of the fewer adhesions in comparison to laparotomy, without increasing the

Flavanol-Enriched Cocoa Powder Alters the Intestinal Microbiota, Tissue and Fluid Metabolite Profiles, and Intestinal Gene Expression in Pigs1234

Science.gov (United States)

Jang, Saebyeol; Sun, Jianghao; Chen, Pei; Lakshman, Sukla; Molokin, Aleksey; Harnly, James M; Vinyard, Bryan T; Urban, Joseph F; Davis, Cindy D; Solano-Aguilar, Gloria

2016-01-01

Background: Consumption of cocoa-derived polyphenols has been associated with several health benefits; however, their effects on the intestinal microbiome and related features of host intestinal health are not adequately understood. Objective: The objective of this study was to determine the effects of eating flavanol-enriched cocoa powder on the composition of the gut microbiota, tissue metabolite profiles, and intestinal immune status. Methods: Male pigs (5 mo old, 28 kg mean body weight) were supplemented with 0, 2.5, 10, or 20 g flavanol-enriched cocoa powder/d for 27 d. Metabolites in serum, urine, the proximal colon contents, liver, and adipose tissue; bacterial abundance in the intestinal contents and feces; and intestinal tissue gene expression of inflammatory markers and Toll-like receptors (TLRs) were then determined. Results: O-methyl-epicatechin-glucuronide conjugates dose-dependently increased (P cocoa powder. The concentration of 3-hydroxyphenylpropionic acid isomers in urine decreased as the dose of cocoa powder fed to pigs increased (75–85%, P cocoa powder/d, respectively. Moreover, consumption of cocoa powder reduced TLR9 gene expression in ileal Peyer’s patches (67–80%, P cocoa powder/d compared with pigs not supplemented with cocoa powder. Conclusion: This study demonstrates that consumption of cocoa powder by pigs can contribute to gut health by enhancing the abundance of Lactobacillus and Bifidobacterium species and modulating markers of localized intestinal immunity. PMID:26936136

Congenital cytomegalovirus related intestinal malrotation: a case report.

Science.gov (United States)

Colomba, Claudia; Giuffrè, Mario; La Placa, Simona; Cascio, Antonio; Trizzino, Marcello; De Grazia, Simona; Corsello, Giovanni

2016-12-07

Cytomegalovirus is the most common cause of congenital infection in the developed countries. Gastrointestinal involvement has been extensively described in both adult and paediatric immunocompromised patients but it is infrequent in congenital or perinatal CMV infection. We report on a case of coexistent congenital Cytomegalovirus infection with intestinal malrotation and positive intestinal Cytomegalovirus biopsy. At birth the neonate showed clinical and radiological evidence of intestinal obstruction. Meconium passed only after evacuative nursing procedures; stooling pattern was irregular; gastric residuals were bile-stained. Laparatomy revealed a complete intestinal malrotation and contextually gastrointestinal biopsy samples of the appendix confirmed the diagnosis of CMV gastrointestinal disease. Intravenous ganciclovir was initiated for 2 weeks, followed by oral valgancyclovir for 6 month. CMV-induced proinflammatory process may be responsible of the interruption of the normal development of the gut or could in turn lead to a disruption in the normal development of the gut potentiating the mechanism causing malrotation. We suggest the hypothesis that an inflammatory process induced by CMV congenital infection may be responsible, in the early gestation, of the intestinal end-organ disease, as the intestinal malrotation. CMV infection should always be excluded in full-term infants presenting with colonic stricture or malrotation.

Is isomerism a risk factor for intestinal volvulus?

Science.gov (United States)

Landisch, Rachel M; Loomba, Rohit S; Salazar, Jose H; Buelow, Matthew W; Frommelt, Michele; Anderson, Robert H; Wagner, Amy J

2018-03-06

Isomerism, or heterotaxy syndrome, affects many organ systems anatomically and functionally. Intestinal malrotation is common in patients with isomerism. Despite a low reported risk of volvulus, some physicians perform routine screening and prophylactic Ladd procedures on asymptomatic patients with isomerism who are found to have intestinal malrotation. The primary aim of this study was to determine if isomerism is an independent risk factor for volvulus. Kid's Inpatient Database data from 1997 to 2012 was utilized for this study. Characteristics of admissions with and without isomerism were compared with a particular focus on intestinal malrotation, volvulus, and Ladd procedure. A logistic regression was conducted to determine independent risk factors for volvulus with respect to isomerism. 15,962,403 inpatient admissions were included in the analysis, of which 7970 (0.05%) patients had isomerism, and 6 patients (0.1%) developed volvulus. Isomerism was associated with a 52-fold increase in the odds of intestinal malrotation by univariate analysis. Of 251 with isomerism and intestinal malrotation, only 2.4% experienced volvulus. Logistic regression demonstrated that isomerism was not an independent risk factor for volvulus. Isomerism is associated with an increased risk of intestinal malrotation but is not an independent risk factor for volvulus. Prognosis study. Level III. Copyright © 2018 Elsevier Inc. All rights reserved.

FEATURES OF INTESTINAL MICROBIOTA IN CHILDREN WITH A SYNDROME OF EXCESSIVE BACTERIAL GROWTH IN THE SMALL INTESTINE

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L. A. Lityaeva

2018-01-01

Full Text Available The purpose of the study was to determine the features of the parietal microbiota of the intestine in children with a verified syndrome of excessive bacterial growth in the small intestine. Clinical and laboratory examination of 25 children at risk of intrauterine infection at the age of 8 months — 4 years with a verified syndrome of excess bacterial growth in the small intestine was performed based on the results of the hydrogen breath test. Investigation of the species and quantitative composition of the parietal intestinal microbiota was carried out with the help of the gas chromatography-mass spectrometry method with determination of the concentration of microbial markers by drop of blood (laboratory of bifidobacteria of the Federal Budgetary Institute of Science Moscow Research Institute of Epidemiology and Microbiology name after G.N. Gabrichevsky. It was revealed that all of them recorded a high concentration of microbial markers of gram-negative anaerobic bacteria of the colon and viruses of the Herpes family due to a deficit of representatives of priority genera (Propionibacterium Freunderherii 5-fold, Eubacterium spp. 4.8-fold, Bifidobacterium spp. 4-fold, Lactobacillus spp. 1.5-fold with an excess of endotoxin (by 1.5—2-fold and a decrease in plasmalogen (by 2-fold. These data testify to the inflammatory process of the small intestinal mucosa, which aggravates the disturbances in its functioning and confirm the informative nature of the gas chromatography and spectrometry method.

A clinico-radiological reappraisal of intestinal tuberculosis

International Nuclear Information System (INIS)

Tandon, R.K.; Sarin, S.K.; Bose, S.L.; Berry, M.; Tandon, B.N.

1986-01-01

Intestinal tuberculosis is still common in developing countries. In 186 patients with intestinal tuberculosis, clinical features, radiological findings and complications were carefully recorded and compared with those from earlier studies with a view to study any possible changes after the liberal use of antitubercular drugs. Sixty two percent of the patients in the present series had had prior exposure to antitubercular drugs. The incidence of systemic symptoms like fever and anorexia, alternating diarrhoea and constipation, peritoneal and lymph node involvements and associated pulmonary lesions were less frequently observed. On the other hand, an indolent and complicated course with intestinal obstruction (47 %) and lower gastrointestinal bleeding (5.5 %) and frequent colonic involvement (19 %) often necessitating surgical intervention appeared to have become more frequent than reported in earlier series. Awareness of these changes in the clinical profile of intestinal tuberculosis should be helpful in the diagnosis and management of the condition. (author)

Stem cell self-renewal in intestinal crypt

International Nuclear Information System (INIS)

Simons, Benjamin D.; Clevers, Hans

2011-01-01

As a rapidly cycling tissue capable of fast repair and regeneration, the intestinal epithelium has emerged as a favored model system to explore the principles of adult stem cell biology. However, until recently, the identity and characteristics of the stem cell population in both the small intestine and colon has remained the subject of debate. Recent studies based on targeted lineage tracing strategies, combined with the development of an organotypic culture system, have identified the crypt base columnar cell as the intestinal stem cell, and have unveiled the strategy by which the balance between proliferation and differentiation is maintained. These results show that intestinal stem cells operate in a dynamic environment in which frequent and stochastic stem cell loss is compensated by the proliferation of neighboring stem cells. We review the basis of these experimental findings and the insights they offer into the mechanisms of homeostatic stem cell regulation.

Oral Administration of Probiotics Increases Paneth Cells and Intestinal Antimicrobial Activity

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Silvia I. Cazorla

2018-04-01

Full Text Available The huge amount of intestinal bacteria represents a continuing threat to the intestinal barrier. To meet this challenge, gut epithelial cells produce antimicrobial peptides (AMP that act at the forefront of innate immunity. We explore whether this antimicrobial activity and Paneth cells, the main intestinal cell responsible of AMP production, are influenced by probiotics administration, to avoid the imbalance of intestinal microbiota and preserve intestinal barrier. Administration of Lactobacillus casei CRL 431 (Lc 431 and L. paracasei CNCM I-1518 (Lp 1518 to 42 days old mice, increases the number of Paneth cells on small intestine, and the antimicrobial activity against the pathogens Staphylococcus aureus and Salmonella Typhimurium in the intestinal fluids. Specifically, strong damage of the bacterial cell with leakage of cytoplasmic content, and cellular fragmentation were observed in S. Typhimurium and S. aureus. Even more important, probiotics increase the antimicrobial activity of the intestinal fluids at the different ages, from weaning (21 days old to old age (180 days old. Intestinal antimicrobial activity stimulated by oral probiotics, do not influence significantly the composition of total anaerobic bacteria, lactobacilli and enterobacteria in the large intestine, at any age analyzed. This result, together with the antimicrobial activity observed against the same probiotic bacteria; endorse the regular consumption of probiotics without adverse effect on the intestinal homeostasis in healthy individuals. We demonstrate that oral probiotics increase intestinal antimicrobial activity and Paneth cells in order to strengthen epithelial barrier against pathogens. This effect would be another important mechanism by which probiotics protect the host mainly against infectious diseases.

St. John's wort attenuates irinotecan-induced diarrhea via down-regulation of intestinal pro-inflammatory cytokines and inhibition of intestinal epithelial apoptosis

International Nuclear Information System (INIS)

Hu Zeping; Yang Xiaoxia; Chan Suiyung; Xu Anlong; Duan Wei; Zhu Yizhun; Sheu, F.-S.; Boelsterli, Urs Alex; Chan, Eli; Zhang Qiang; Wang, J.-C.; Ee, Pui Lai Rachel; Koh, H.L.; Huang Min; Zhou Shufeng

2006-01-01

Diarrhea is a common dose-limiting toxicity associated with cancer chemotherapy, in particular for drugs such as irinotecan (CPT-11), 5-fluouracil, oxaliplatin, capecitabine and raltitrexed. St. John's wort (Hypericum perforatum, SJW) has anti-inflammatory activity, and our preliminary study in the rat and a pilot study in cancer patients found that treatment of SJW alleviated irinotecan-induced diarrhea. In the present study, we investigated whether SJW modulated various pro-inflammatory cytokines including interleukins (IL-1β, IL-2, IL-6), interferon (IFN-γ) and tumor necrosis factor-α (TNF-α) and intestinal epithelium apoptosis in rats. The rats were treated with irinotecan at 60 mg/kg for 4 days in combination with oral SJW or SJW-free control vehicle at 400 mg/kg for 8 days. Diarrhea, tissue damage, body weight loss, various cytokines including IL-1β, IL-2, IL-6, IFN-γ and TNF-α and intestinal epithelial apoptosis were monitored over 11 days. Our studies demonstrated that combined SJW markedly reduced CPT-11-induced diarrhea and intestinal lesions. The production of pro-inflammatory cytokines such as IL-1β, IFN-γ and TNF-α was significantly up-regulated in intestine. In the mean time, combined SJW significantly suppressed the intestinal epithelial apoptosis induced by CPT-11 over days 5-11. In particular, combination of SJW significantly inhibited the expression of TNF-α mRNA in the intestine over days 5-11. In conclusion, inhibition of pro-inflammatory cytokines and intestinal epithelium apoptosis partly explained the protective effect of SJW against the intestinal toxicities induced by irinotecan. Further studies are warranted to explore the potential for STW as an agent in combination with chemotherapeutic drugs to lower their dose-limiting toxicities

Scintigraphic visualization of bacterial translocation in experimental strangulated intestinal obstruction

International Nuclear Information System (INIS)

Galeev, Yu.M.; Popov, M.V.; Salato, O.V.; Lishmanov, Yu.B.; Grigorev, E.G.; Aparcin, K.A.

2009-01-01

The purpose of this study was to obtain scintigraphic images depicting translocation of 99m Tc-labelled Escherichia coli bacteria through the intestinal barrier and to quantify this process using methods of nuclear medicine. Thirty male Wistar rats (including 20 rats with modelled strangulated intestinal obstruction and 10 healthy rats) were used for bacterial scintigraphy. 99m Tc-labelled E. coli bacteria ( 99m Ts-E. coli) with an activity of 7.4-11.1 MBq were administered into a section of the small intestine. Scintigraphic visualization of bacterial translocation into organs and tissues of laboratory animals was recorded in dynamic (240 min) and static (15 min) modes. The number of labelled bacteria, which migrated through the intestinal barrier, was quantified by calculating the translocation index (TI). Control indicated no translocation of 99m Ts-E. coli administered into the intestine through the parietes of the small intestine's distal part in healthy animals. Animals with strangulated obstruction demonstrated different migration strength and routes of labelled bacteria from strangulated and superior to strangulation sections of the small intestine. 99m Ts-E. coli migrated from the strangulated loop into the peritoneal cavity later causing systemic bacteraemia through peritoneal resorption. The section of the small intestine, which was superior to the strangulation, demonstrated migration of labelled bacteria first into the portal and then into the systemic circulation. The strangulated section of the small intestine was the main source of bacteria dissemination since the number of labelled bacteria, which migrated from this section significantly, exceeded that of the area superior to the strangulation section of the small intestine (p = 0.0003). Bacterial scintigraphy demonstrated the possibility of visualizing migration routes of labelled bacteria and quantifying their translocation through the intestinal barrier. This approach to study bacterial

Intestinal lymphangiectasia mimicking primary peritoneal carcinoma.

Science.gov (United States)

Steines, Jennifer C; Larson, Joshua H; Wilkinson, Neal; Kirby, Patricia; Goodheart, Michael J

2010-10-01

Intestinal lymphangiectasia is an obstruction of the lymphatic system. We report on a patient with mesenteric adenopathy and an elevated CA125 level, which were suspicious for peritoneal carcinoma. Further evaluation and bowel resection identified intestinal lymphangiectasia. This disease should be considered in patients with mesenteric adenopathy and a small bowel mass. Copyright © 2010 Mosby, Inc. All rights reserved.

Epidemiology and Diagnosis of Feline Intestinal Lymphosarcomas in Egypt

Directory of Open Access Journals (Sweden)

Fayez Awadalla Salib

2012-07-01

Full Text Available Feline intestinal lymphosarcomas are mostly caused by Feline Leukemia Virus (FeLV. Unfortunately, there is no available vaccine for FeLV in Egypt. The diagnosis of feline intestinal lymphosarcomas depends upon abdominal palpation, x-rays examination, ultrasonography, direct ELISA and histopathology of masses excised during laparotomy. The recorded clinical signs in intestinal lymphosarcoma affected cats were variable including vomiting, fever, anorexia, ascites, anemia, dyspnea, constipation and emaciation. The affected lymph nodes were mesenteric, mediastinal and retropharyngeal. The prevalence of intestinal lymphosarcomas in the examined cats was 4.03 % (11 out of 273 cats. The prevalence was higher in queens than toms (2.93 % and 0.73 % respectively. The Siamese cats had higher prevalence than the Sherazy ones (2.56 % and 1.47 % respectively. X-ray films and ultrasonographic images performed on the eleven cats suffered from intestinal lymphosarcomas revealed ascities and abdominal masses. The comparison of ELISA and histopathology (of excised masses results showed that 9 out of 11 intestinal lymphosarcoma affected cats were infected with FeLV that proved not all cases of intestinal lymphosarcoma were caused by FeLV. The sensitivity, specificity and accuracy of ELISA to diagnose intestinal lymphosarcoma in cats were 81.81 %, 100 % and 92 % respectively. Gross autopsy of the collected lymph nodes, livers, kidneys revealed that gross lymphadenopathy involving one or more nodes, hepatomegaly and kidney enlargement. Microscopically, the examined tissues specimens showed that the normal architecture of the examined lymph nodes, livers, and kidneys has been replaced by a diffuse infiltrate of both lymphocytes and lymphoblasts. The vast majority of the cells are small lymphocyte-type cells with round basophilic nuclei and a sparse rim of cytoplasm. The eleven intestinal lymphosarcoma affected cats exposed to abdominal exploratory surgery (laparotomy