WorldWideScience

Sample records for inner-galaxy alfa low-latitude

  1. Properties of Cold HI Emission Clouds in the Inner-Galaxy ALFA Survey

    Science.gov (United States)

    Hughes, James Marcus; Gibson, Steven J.; Noriega-Crespo, Alberto; Newton, Jonathan; Koo, Bon-Chul; Douglas, Kevin A.; Peek, Joshua Eli Goldston; Park, Geumsook; Kang, Ji-hyun; Korpela, Eric J.; Heiles, Carl E.; Dame, Thomas M.

    2017-01-01

    Star formation, a critical process within galaxies, occurs in the coldest, densest interstellar clouds, whose gas and dust content are observed primarily at radio and infrared wavelengths. The formation of molecular hydrogen (H2) from neutral atomic hydrogen (HI) is an essential early step in the condensation of these clouds from the ambient interstellar medium, but it is not yet completely understood, e.g., what is the predominant trigger? Even more troubling, the abundance of H2 may be severely underestimated by standard tracers like CO, implying significant "dark" H2, and the quantity of HI may also be in error if opacity effects are neglected. We have developed an automated method to account for both HI and H2 in cold, diffuse clouds traced by narrow-line HI 21-cm emission in the Arecibo Inner-Galaxy ALFA (I-GALFA) survey. Our algorithm fits narrow (2-5 km/s), isolated HI line profiles to determine their spin temperature, optical depth, and true column density. We then estimate the "visible" H2 column in the same clouds with CfA and Planck CO data and the total gas column from dust emission measured by Planck, IRAS, and other surveys. Together, these provide constraints on the dark H2 abundance, which we examine in relation to other cloud properties and stages of development. Our aim is to build a database of H2-forming regions with significant dark gas to aid future analyses of coalescing interstellar clouds. We acknowledge support from NSF, NASA, Western Kentucky University, and Williams College. I-GALFA is a GALFA-HI survey observed with the 7-beam ALFA receiver on the 305-meter William E. Gordon Telescope. The Arecibo Observatory is a U.S. National Science Foundation facility operated under sequential cooperative agreements with Cornell University and SRI International, the latter in alliance with the Ana G. Mendez-Universidad Metropolitana and the Universities Space Research Association.

  2. Low-latitude ionospheric effects on SBAS

    Science.gov (United States)

    Arenas, J.; Sardón, E.; Sainz, A.; Ochoa, B.; Magdaleno, S.

    2016-06-01

    Satellite-based augmentation systems (SBAS) provide augmentation to Global Navigation Satellite Systems (GNSS) users in three areas: (1) broadcasting accurate corrections to GNSS satellite ephemeris, (2) providing a real-time empirical ionospheric model in the service area, and (3) providing integrity information in the form of estimates of the confidence of the ephemeris corrections and ionospheric delays. Ionospheric effects on SBAS are twofold: (a) the input data used by the SBAS will be affected by ionospheric effects, and (b) the more perturbed the ionosphere is, the more difficult it will be to provide accurate and reliable ionospheric information to the users. The ionosphere at low latitudes presents larger variability and more intense phenomena than at midlatitudes. Therefore, SBAS providing service to low-latitude regions will be more affected than those at other latitudes. From the different low-latitude ionospheric effects, this paper will focus on those having the largest impact on SBAS, which are total electron content temporal and spatial gradients, ionospheric scintillations, and depletions. This paper will present the impact of these effects on EGNOS (European Global Navigation Overlay System), the European SBAS. Although EGNOS can be considered as a midlatitude SBAS, it has to provide coverage down to rather low latitudes, so sometimes low-latitude ionospheric effects are observed in the EGNOS data. It will be shown how EGNOS performs under nominal conditions and how its performance is degraded when low-latitude ionospheric phenomena occur. Real EGNOS data affected by low-latitude ionospheric phenomena will be used.

  3. Low Latitude Aurora: Index of Solar Activity

    Science.gov (United States)

    Bekli, M. R.; Aissani, D.; Chadou, I.

    2010-10-01

    Observations of aurora borealis at low latitudes are rare, and are clearly associated with high solar activity. In this paper, we analyze some details of the solar activity during the years 1769-1792. Moreover, we describe in detail three low latitude auroras. The first event was reported by ash-Shalati and observed in North Africa (1770 AD). The second and third events were reported by l'Abbé Mann and observed in Europe (1770 and 1777 AD).

  4. Obliquity forcing of low-latitude climate

    NARCIS (Netherlands)

    Bosmans, J.H.C.; Hilgen, F.J.; Tuenter, Erik; Lourens, L.J.

    2015-01-01

    The influence of obliquity, the tilt of the Earth's rotational axis, on incoming solar radiation at low latitudes is small, yet many tropical and subtropical palaeoclimate records reveal a clear obliquity signal. Several mechanisms have been proposed to explain this signal, such as the remote

  5. Obliquity forcing of low-latitude climate

    NARCIS (Netherlands)

    Bosmans, J.H.C.; Hilgen, F.J.; Tuenter, Erik; Lourens, L.J.

    2015-01-01

    The influence of obliquity, the tilt of the Earth's rotational axis, on incoming solar radiation at low latitudes is small, yet many tropical and subtropical palaeoclimate records reveal a clear obliquity signal. Several mechanisms have been proposed to explain this signal, such as the remote influe

  6. TIDI observations relating to low latitude aeronomy

    Science.gov (United States)

    Niciejewski, R.; Killeen, T.; Kafkalidis, J.; Wu, Q.; Skinner, W.; Solomon, S.; Ortland, D.; Gell, D.; Gablehouse, D.; Johnson, R.

    2003-04-01

    The TIDI instrument aboard the TIMED satellite has been observing the neutral winds in the upper atmosphere on a routine basis since early January 2002. The instrument simultaneously samples the thin limb of the Earth with four separate telescopes providing two forward views and two rearward views, one of each on either side of the orbital path. At equator crossings, these two side views are separated by about 30 degrees of longitude at the tangent point altitude, or 2 hours of local time. Thus, on any orbit TIDI obtains two horizontal vector winds at the dayside equator crossing and two on the nightside equator crossing as well as for all low latitudes. This is significantly greater than the data output of either the HRDI or the DE-2 satellite observations. This paper will describe the climatology that has been obtained by the TIDI instrument since early 2002 for low latitudes. The precession rate of TIMED supports two month averaging of data sets in order to sample all local solar time. Tidal structure is evident in the resulting zonal and meridional winds for mesosphere and lower thermosphere altitudes.

  7. Electrodynamics of ionospheric weather over low latitudes

    Science.gov (United States)

    Abdu, Mangalathayil Ali

    2016-12-01

    The dynamic state of the ionosphere at low latitudes is largely controlled by electric fields originating from dynamo actions by atmospheric waves propagating from below and the solar wind-magnetosphere interaction from above. These electric fields cause structuring of the ionosphere in wide ranging spatial and temporal scales that impact on space-based communication and navigation systems constituting an important segment of our technology-based day-to-day lives. The largest of the ionosphere structures, the equatorial ionization anomaly, with global maximum of plasma densities can cause propagation delays on the GNSS signals. The sunset electrodynamics is responsible for the generation of plasma bubble wide spectrum irregularities that can cause scintillation or even disruptions of satellite communication/navigation signals. Driven basically by upward propagating tides, these electric fields can suffer significant modulations from perturbation winds due to gravity waves, planetary/Kelvin waves, and non-migrating tides, as recent observational and modeling results have demonstrated. The changing state of the plasma distribution arising from these highly variable electric fields constitutes an important component of the ionospheric weather disturbances. Another, often dominating, component arises from solar disturbances when coronal mass ejection (CME) interaction with the earth's magnetosphere results in energy transport to low latitudes in the form of storm time prompt penetration electric fields and thermospheric disturbance winds. As a result, drastic modifications can occur in the form of layer restructuring (Es-, F3 layers etc.), large total electron content (TEC) enhancements, equatorial ionization anomaly (EIA) latitudinal expansion/contraction, anomalous polarization electric fields/vertical drifts, enhanced growth/suppression of plasma structuring, etc. A brief review of our current understanding of the ionospheric weather variations and the

  8. Assimilative modeling of low latitude ionosphere

    Science.gov (United States)

    Pi, Xiaoqing; Wang, Chunining; Hajj, George A.; Rosen, I. Gary; Wilson, Brian D.; Mannucci, Anthony J.

    2004-01-01

    In this paper we present an observation system simulation experiment for modeling low-latitude ionosphere using a 3-dimensional (3-D) global assimilative ionospheric model (GAIM). The experiment is conducted to test the effectiveness of GAIM with a 4-D variational approach (4DVAR) in estimation of the ExB drift and thermospheric wind in the magnetic meridional planes simultaneously for all longitude or local time sectors. The operational Global Positioning System (GPS) satellites and the ground-based global GPS receiver network of the International GPS Service are used in the experiment as the data assimilation source. 'The optimization of the ionospheric state (electron density) modeling is performed through a nonlinear least-squares minimization process that adjusts the dynamical forces to reduce the difference between the modeled and observed slant total electron content in the entire modeled region. The present experiment for multiple force estimations reinforces our previous assessment made through single driver estimations conducted for the ExB drift only.

  9. Red Supergiants in the Inner Galaxy: Stellar Properties

    Science.gov (United States)

    Messineo, Maria; Zhu, Qingfeng; Menten, Karl M.; Ivanov, Valentin D.; Figer, Donald F.; Kudritzki, Rolf-Peter; Chen, C.-H. Rosie

    2017-02-01

    Red supergiants (RSGs) are luminous cool stars detectable in disks of distant spirals. About a thousand are known in the Galaxy. Here, we analyze a sample of late-type stars recently observed by Messineo et al. in the inner Galaxy (10^\\circ 45 Å, ≳M0I). In this work, luminosities are estimated with infrared measurements and distance moduli for 47 spectroscopically classified RSGs; they range from 3.2× {10}4 to 1.3× {10}5 {L}ȯ . Six other RSGs with smaller EW(CO)s are classified according to their luminosities. Using a prescription based on {K}{{s}}{--}[W4], moderate mass-loss rates from 10‑8 to {10}-6.5 {M}ȯ yr‑1 are inferred. In addition, we report on H and K spectra of 26 stars at R = 1500–2200. EWs of the CO at 2.293 and 1.620 μm, and of atomic lines, are consistent with those of nearby RSGs, within uncertainties. Mg i appears to be a useful diagnostic to confirm RSGs at R = 1500–2200. RSG #66 is a member of the cluster Alicante 7. Star #92 is projected onto the overdensity #495 of Camargo et al., but our analysis suggests they are unrelated. Remaining targets are isolated from other known RSGs within ≈3‧.

  10. VizieR Online Data Catalog: Arecibo Pulsar-ALFA (PALFA) survey. IV. (Lazarus+, 2015)

    Science.gov (United States)

    Lazarus, P.; Brazier, A.; Hessels, J. W. T.; Karako-Argaman, C.; Kaspi, V. M.; Lynch, R.; Madsen, E.; Patel, C.; Ransom, S. M.; Scholz, P.; Swiggum, J.; Zhu, W. W.; Allen, B.; Bogdanov, S.; Camilo, F.; Cardoso, F.; Chatterjee, S.; Cordes, J. M.; Crawford, F.; Deneva, J. S.; Ferdman, R.; Freire, P. C. C.; Jenet, F. A.; Knispel, B.; Lee, K. J.; van Leeuwen, J.; Lorimer, D. R.; Lyne, A. G.; McLaughlin, M. A.; Siemens, X.; Spitler, L. G.; Stairs, I. H.; Stovall, K.; Venkataraman, A.

    2016-02-01

    The Arecibo Pulsar-ALFA (PALFA) survey observations have been restricted to the two regions of the Galactic plane (|b|<5°) visible from the Arecibo observatory, the inner Galaxy (32°<~l<~77°), and the outer Galaxy (168°<~l<~214°). Integration times are 268s and 180s for inner and outer Galaxy observations, respectively. Observations conducted with the 7-beam Arecibo L-band Feed Array (ALFA) receiver of the Arecibo Observatory William E. Gordon 305m Telescope have a bandwidth of 322MHz centered at 1375MHz. PALFA survey data have been recorded with the Mock spectrometers since 2009. (2 data files).

  11. Epoetin Alfa Injection

    Science.gov (United States)

    ... Combivir), a medication used to treat human immunodeficiency virus (HIV). Epoetin alfa injection is also used before ... inject epoetin alfa, as directed by your doctor. Write down the date, time, dose of epoetin alfa ...

  12. Multiflash whistlers in ELF-band observed at low latitude

    Directory of Open Access Journals (Sweden)

    Ashutosh K. Singh

    2011-01-01

    Full Text Available Multiflash whistler-like event in the ELF-band, observed during March 1998 at low latitude station Jammu, is reported. The most prominent feature of these events is the multiflash nature along with the decrease in frequency within a very short span of time resembling similar to terrestrial whistlers. The events have a significantly smaller time duration (0.5–3.5 s than those reported earlier from high, mid and low latitudes and also display a diurnal maximum occurring around 09:30 h (IST. There have been similar reportings from other latitudes, but whistlers in the ELF-band with a multiflash nature along with a precursor emission have never been reported. Lightning seems to be the dominant source for the ELF whistlers reported here.

  13. Earth's magnetosphere formed by the low-latitude boundary layer

    CERN Document Server

    Heikkila, W J

    2011-01-01

    The author argues that, after five decades of debate about the interactive of solar wind with the magnetosphere, it is time to get back to basics. Starting with Newton's law, this book also examines Maxwell's equations and subsidiary equations such as continuity, constitutive relations and the Lorentz transformation; Helmholtz' theorem, and Poynting's theorem, among other methods for understanding this interaction. Includes chapters on prompt particle acceleration to high energies, plasma transfer event, and the low latitude boundary layer More than 200 figures illustrate the text Includes a color insert.

  14. Multifractal analysis of low-latitude geomagnetic fluctuations

    Directory of Open Access Journals (Sweden)

    M. J. A. Bolzan

    2009-02-01

    Full Text Available The technique of large deviation multifractal spectrum has shown that the high-latitude (77.5° N, 69.2° W geomagnetic fluctuations can be described from direct dissipation process or loading-unloading regimes of the solar wind-magnetosphere coupling. In this paper, we analyze the H-component of low-latitude (22.4° S, 43.6° W geomagnetic field variability observed during the month of July 2000 at the Geomagnetic Observatory, Vassouras, RJ, Brazil. The variability pattern during this period is a mixture of quiet and disturbed days including the Bastille Day intense geomagnetic storm on 15 July. Due to the complexity of this data, we pursue a detailed analysis of the geomagnetic fluctuations in different time scales including a multifractal approach using the singular power spectrum deviations obtained from the wavelet transform modulus maxima (WTMM. The results suggest, as observed from high-latitude data, the occurrence of low-latitude multifractal processes driving the intermittent coupling between the solar wind-magnetosphere and geomagnetic field variations. On finer scales possible physical mechanisms in the context of nonlinear magnetosphere response are discussed.

  15. The domination of Saturn's low latitude ionosphere by ring `rain'

    CERN Document Server

    O'Donoghue, J; Melin, H; Jones, G H; Cowley, S W H; Miller, S; Baines, K H; Blake, J S D

    2013-01-01

    Saturn's ionosphere is produced when the otherwise neutral atmosphere is exposed to a flow of energetic charged particles or solar radiation. At low latitudes the latter should result in a weak planet-wide glow in infrared (IR), corresponding to the planet's uniform illumination by the Sun. The observed low-latitude ionospheric electron density is lower and the temperature higher than predicted by models. A planet-ring magnetic connection has been previously suggested in which an influx of water from the rings could explain the lower than expected electron densities in Saturn's atmosphere. Here we report the detection of a pattern of features, extending across a broad latitude band from ~25 to 60 degrees, that is superposed on the lower latitude background glow, with peaks in emission that map along the planet's magnetic field lines to gaps in Saturn's rings. This pattern implies the transfer of charged water products from the ring-plane to the ionosphere, revealing the influx on a global scale, flooding betw...

  16. Orbital control of low-latitude seasonality during the Eemian

    Science.gov (United States)

    Winter, A.; Paul, A.; Nyberg, J.; Oba, T.; Lundberg, J.; Schrag, D.; Taggart, B.

    2003-01-01

    We used Sr/Ca and stable isotope data from well dated and preserved corals from the northeastern Caribbean to determine the seasonal environmental conditions for four continuous years during the Eemian, the last time the Earth was in a prolonged warm phase. We determined that the seasonal range in SST during the Eemian was 25??-30?? C. This is ???1-2?? larger than at present and caused primarily by winter cooling and, only to a small degree, by summer warming. As climate modeling studies indicate, the bias towards colder winters can be explained by changes in low latitude insolation induced by altered orbital parameters, modulated by atmospheric CO2 levels that were lower than today. Milankovitch forcing at higher latitudes was probably less important.

  17. Statistical characteristics of low-latitude ionospheric scintillation over China

    Science.gov (United States)

    Liu, Kangkang; Li, Guozhu; Ning, Baiqi; Hu, Lianhuan; Li, Hongke

    2015-03-01

    The Global Positioning System (GPS) L-band ionospheric scintillation produced by electron density irregularities in the ionospheric E- and F-regions, is mainly a low- and high-latitude phenomenon. In this study, the statistical behavior of GPS ionospheric scintillation over a Chinese low-latitude station Sanya (18.3°N, 109.6°E; dip lat: 12.8°N) has been investigated. A detailed study on the seasonal and solar activity dependence of scintillation occurrence during July 2004-December 2012 show that the amplitude scintillation pattern, with a maximum occurrence during equinox of solar maximum, agrees with plasma bubble observations by in situ satellites in this longitude. A few daytime periodic scintillation events are found during June solstice months of solar minimum. Interestingly, a significant equinoctial asymmetry of scintillation onset time is found in 2011-2012. The initiation of scintillation during September-October is on average earlier than that of March-April about 25 min. Meanwhile, the zonal drifts of irregularities estimated using two spatially separated GPS receivers over Sanya show a similar behavior during the two equinoxes, slowly decreasing from 150 m/s at post-sunset to 50 m/s near midnight. The possible mechanisms responsible for the occurrence characteristics of GPS scintillation over Sanya, and relevant aspects of the zonal drifts of the irregularities are discussed.

  18. Analysis of the atmospheric upward radiation in low latitude area

    Science.gov (United States)

    Li, Haiying; Wu, Zhensen; Lin, Leke; Lu, Changsheng

    2016-10-01

    Remote sensing using THz wave has irreplaceable advantage comparing to the microwave and the infrared waves, and study on the THz remote sensing become more and more popular in recent years. The major applications of the remote sensing in THz wavelengths are the retrieval of the atmospheric parameters and the microphysical information of the ice cloud. The remote sensing of the atmosphere is based on the radiation of THz wave along the earth-space path of which the most significant part is the upward radiation of the atmosphere. The upward radiation of the atmosphere in sunny day in the low latitude area is computed and analyzed in this paper. The absorption of THz wave by the atmosphere is calculated using the formulations illustrated in the Recommendation ITU-R P.676 to save machine hour, the frequency range is then restricted below 1THz. The frequencies used for the retrieval of atmospheric parameters such as temperature and water content are usually a few hundred GHz, at the lower end of THz wavelengths, so this frequency range is sufficient. The radiation contribution of every atmospheric layer for typical frequencies such as absorption window frequencies and peak frequencies are analyzed. Results show that at frequencies which absorption is severe, information about lower atmosphere cannot reach the receiver onboard a satellite or other high platforms due to the strong absorption along the path.

  19. A review of recent MLT studies at low latitudes

    Directory of Open Access Journals (Sweden)

    B. R. Clemesha

    2004-09-01

    Full Text Available Recent years have shown a continuing interest in studies of the mesosphere-lower thermosphere region at low latitudes, with more than 50 papers dealing specifically with this area published over the past 5 years. Experimental ground-based work has been carried out mainly in South America and the Caribbean, India and the Pacific areas. Subjects of interest include gravity waves, tides and planetary waves, the temperature structure of the mesopause region, with special reference to temperature inversions and the two-level mesopause, sporadic neutral layers and their relationship with ionized layers, the possible effects of the micrometeoroid influx, and long-term trends in the MLT region. Experimental techniques in use include MF, MST and meteor radar, lidar, airglow (including satellite-borne limb-scanning measurements and rocket-borne instruments. Airglow imaging has shown itself to be a particularly useful technique, mainly for studying gravity wave propagation in the MLT region. This paper will present highlights of recent work and will discuss some of the problems which remain to be resolved.

  20. Magnetic field draping at the low-latitude magnetopause

    Science.gov (United States)

    Richard, R. L.; Lotko, W.

    1991-01-01

    Magnetohydrodynamic simulations are used to investigate the structure of the low-latitude magnetopause for interplanetary magnetic field conditions with a dominant southward component. The structure is self-consistently calculated as an initial-value problem in which the system is allowed to evolve into a quasi-steady state. All components of the 3D velocity and magnetic field as well as compressibility, resistivity, and viscosity are included in the 2D calculation. The simulation model shows that magnetic field draping can occur at the magnetopause boundary when magnetic merging takes place in the presence of a tangential shear flow. For 'normal' (positive Bx) draping, the higher-latitude portion of the field lines are curved toward the sun on the magnetospheric side of the magnetopause and away from the sun on the magnetosheath side. The thickness of the normal draping structure scales with the viscosity. The field-aligned current system that accompanies normal magnetic draping is consistent with the sense of the region 1 currents that flow into the dayside ionosphere.

  1. The ALFA Trigger Simulator

    CERN Document Server

    Dziedzic B

    2015-01-01

    The paper presents basic information about ALFA detectors used in the ATLAS experiment, and the structure of currently developed device used to test a new ALFA trigger interface. It discusses the block diagram of the device, principle of its operation, implementation details and future plans for developing the Simulator.

  2. Ionosphere-Thermosphere Coupling in Jupiter's Low Latitudes

    Science.gov (United States)

    Stallard, T.; Melin, H.; Johnson, R.; O'Donoghue, J.; Moore, L.; Miller, S.; Tao, C.; Achilleos, N. A.; Smith, C.; Ray, L. C.; Yates, J. N.

    2015-12-01

    One of the leading problems in our understanding of Jupiter's atmosphere, known colloquially as the 'energy crisis', is that the upper atmosphere has global temperatures far in excess of that predicted by solar heating. Unlike the Earth, solar heating has only a small effect on the thermosphere, varying little in temperature with local time, and with equatorial neutrals co-rotating with the planet due to meridional advection. Within the auroral region, ionosphere-thermosphere coupling produces strong flows and results in huge Joule Heating from auroral currents. In this region, the temperature excess can be explained, but Jupiter's fast rotation means that Coriolis forces prevent energy in the poles from transferring equatorward, so there remains no explanation of why low latitudes are overheated by a factor of 3-5 over that predicted by solar heating alone.Despite this anomaly, although the past twenty years has seen a wealth of new data and results in Jupiter's auroral region, studies of the equatorial region have been somewhat limited. This lack of investigation comes partly from the apparent uniform nature of the equatorial region, and partly from the difficulty in observing this region. It is only in the past three years that observers begun to re-examine this region, revealing evidence of complex interactions between the thermosphere and ionosphere, including what appears to be thermospheric weather patterns at a fixed planetary longitudes, stable over two decades; perhaps caused by continuous flows from the auroral region. Here, we introduce our recent research, in order to compare and contrast what has been observed at Jupiter with the more well understood interactions between Earth's ionosphere and thermosphere. We hope that this will open a discussion between the communities that will improve our understanding of the underlying physical processes, as they occur at both planets.

  3. Turbulent oceanic western-boundary layers at low latitude

    Science.gov (United States)

    Quam Cyrille Akuetevi, Cataria; Wirth, Achim

    2013-04-01

    Low latitude oceanic western-boundary layers range within the most turbulent regions in the worlds ocean. The Somali current system with the Great Whirl and the Brazilian current system with its eddy shedding are the most prominent examples. Results from analytical calculations and integration of a one layer reduced-gravity fine resolution shallow water model is used to entangle this turbulent dynamics. Two types of wind-forcing are applied: a remote Trade wind forcing with maximum shear along the equator and a local Monsoon wind forcing with maximum shear in the vicinity of the boundary. For high values of the viscosity (> 1000m2s-1) the stationary solutions compare well to analytical predictions using Munk and inertial layer theory. When lowering the friction parameter time dependence results. The onset of instability is strongly influenced by inertial effects. The unstable boundary current proceeds as a succession of anti-cyclonic coherent eddies performing a chaotic dynamics in a turbulent flow. The dynamics is governed by the turbulent fluxes of mass and momentum. We determine these fluxes by analyzing the (potential) vorticity dynamics. We demonstrate that the boundary-layer can be separated in four sub-layers, which are (starting from the boundary): (1) the viscous sub-layer (2) the turbulent buffer-layer (3) the layer containing the coherent structures and (4) the extended boundary layer. The characteristics of each sub-layer and the corresponding turbulent fluxes are determined, as are the dependence on latitude and the type of forcing. A new pragmatic method of determining the eddy viscosity, based on Munk-layer theory, is proposed. Results are compared to observations and solutions of the multi-level primitive equation model (DRAKKAR).

  4. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  5. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  6. A survey of Radio Recombination Lines using Ooty Radio Telescope at 328 MHz in the Inner Galaxy

    CERN Document Server

    Baddi, Raju

    2012-01-01

    A survey of radio recombination lines in the Galactic plane with longitude $-32^o < l < +80^o$ and latitude $b<\\pm3^o$ using Ooty Radio Telescope(ORT) at 328 MHz has been reported. ORT observations were made using a New Digital Backend(NDB) augmented to it recently. With NDB ORT had a beam of $2^o.3 \\times 2^o.2 sec(\\delta)$ and a passband of $\\sim$1 MHz in the spectral line mode. The above mentioned Galactic region was divided into $\\sim 2^o \\times 2^o$ patches with the ORT beam pointed to the center. The ORT observations form a study of distribution of extended low-density warm-ionized medium(ELDWIM) in the inner Galaxy using H271$\\alpha$ RL. By obtaining kinematical distances using $V_{LSR}$ of the H271$\\alpha$ RLs the distribution of ELDWIM clouds within the inner Galaxy has been deduced for the region given above.

  7. Interferon Alfa-2b Injection

    Science.gov (United States)

    Interferon alfa-2b injection is used to treat a number of conditions.Interferon alfa-2b injection is used alone or in ... Hodgkin's lymphoma (NHL; a slow-growing blood cancer). Interferon alfa-2b is in a class of medications ...

  8. Drotrecogin alfa Eli Lilly.

    Science.gov (United States)

    de Jonge, E

    2002-04-01

    Drotrecogin alfa (Xigris, recombinant activated protein C) is an anticoagulant developed and launched by Eli Lilly & Co for the treatment of sepsis [333781], [339372], [430133], [436271]. The FDA and the EMEA accepted the brand name Xigris for drotrecogin alfa in June 2001. This trade name had been proposed by Lilly in place of the previous brand name, Zovant, which was deemed unacceptable by the EMEA due to concerns that the name could be confused with hospital-based drugs [412512]. Filings for sepsis were made in the US, EU and Australia in February 2001 [398514], [447870] and in March 2001, the US FDA assigned drotrecogin alfa Priority Review status [403435]. The FDA extended the action date from July 27 to October 27, 2001 for completion of its review of the biologics license application (BLA) for drotrecogin alfa to assess further supplementary data submitted by Lilly [412512]. At the October 16, 2001 meeting (postponed from September 12), the FDA Advisory Committee on Anti-Infective Drugs split 10 to 10 over whether to recommend approval [425873], [425940]. In late October 2001, Lilly received an approvable letter from the FDA for the treatment of severe sepsis. Approval was contingent upon successful negotiation of labeling, agreement on post-approval clinical trials, and successful completion of manufacturing inspections [427301]. In November 2001, the FDA approved drotrecogin alfa for the reduction of mortality in adult patients with severe sepsis who have a high risk of death [430133]; the product was launched onto the US market days later [436271]. Following the FDA committee's split decision in October 2001, Credit Suisse First Boston, which expected mid-2002 approval but with restrictive labeling, revised its predictions from $1.265 billion in 2004 sharply downwards to $543 million [425929].

  9. Low-Latitude Atmosphere-Ionosphere Effects Initiated by Strong Earthquakes Preparation Process

    Directory of Open Access Journals (Sweden)

    Sergey Pulinets

    2012-01-01

    Full Text Available Ionospheric and atmospheric anomalies registered around the time of strong earthquakes in low-latitude regions are reported now regularly. Majority of these reports have the character of case studies without clear physical mechanism proposed. Here we try to present the general conception of low-latitude effects using the results of the recent author’s publications, including also rethinking the earlier results interpreted basing on recently established background physical mechanisms of anomalies generation. It should be underlined that only processes initiated by earthquake preparation are considered. Segregation of low-latitude regions for special consideration is connected with the important role of ionospheric equatorial anomaly in the seismoionospheric coupling and specific character of low-latitude earthquake initiated effects. Three main specific features can be marked in low-latitude ionospheric anomalies manifestation: the presence of magnetic conjugacy in majority of cases, local longitudinal asymmetry of effects observed in ionosphere in relation to the vertical projection of epicenter onto ionosphere, and equatorial anomaly reaction even on earthquakes outside equatorial anomaly (i.e., 30–40 LAT. The equality of effects morphology regardless they observed over land or over sea implies only one possible explanation that these anomalies are initiated by gaseous emanations from the Earth crust, and radon plays the major role.

  10. Quasi-periodic VLF emissions observed during daytime at a low latitude Indian ground station Jammu

    Indian Academy of Sciences (India)

    K K Singh; J Singh; R P Patel; A K Singh; R P Singh; Rejesh Singh; P A Ganai

    2009-06-01

    This paper reports quasi-periodic pulsing hiss emissions recorded during daytime in the frequency range of 50 Hz –15 kHz at low latitude station Jammu (geomag.lat.=22° 26′N; =1.17). It is noted that pulsing VLF emissions are a rare phenomena at low latitudes.The various spectrograms of pulsing VLF hiss emissions presented in this paper clearly show band limited spectrums regularly pulsing with almost equal period of the order of few seconds in the frequency range of ∼3-8 kHz. Generation and propagation mechanism of these emissions are briefly discussed.

  11. Radio detection prospects for a bulge population of millisecond pulsars as suggested by Fermi LAT observations of the inner Galaxy

    CERN Document Server

    Calore, Francesca; Donato, Fiorenza; Hessels, Jason W T; Weniger, Christoph

    2015-01-01

    Analogously to globular clusters, the dense stellar environment of the Galactic center has been proposed to host a large population of as-yet undetected millisecond pulsars (MSPs). Recently, this hypothesis found support in the analysis of gamma rays from the inner Galaxy seen by the Large Area Telescope (LAT) aboard the Fermi satellite, which revealed a possible excess of diffuse GeV photons in the inner 15 deg about the Galactic center (Fermi GeV excess). The excess can be interpreted as the collective emission of thousands of MSPs in the Galactic bulge, with a spherical distribution that strongly peaks towards the Galactic center. In order to fully establish the MSP interpretation, it is essential to find corroborating evidence in multi-wavelength searches, most notably through the detection of radio pulsation from individual bulge MSPs. Based on globular cluster observations and the gamma-ray emission from the inner Galaxy, we investigate the prospects for detecting MSPs in the Galactic bulge. While previ...

  12. Low mass X-ray binaries in the Inner Galaxy: implications for millisecond pulsars and the GeV excess

    Energy Technology Data Exchange (ETDEWEB)

    Haggard, Daryl; Heinke, Craig; Hooper, Dan; Linden, Tim

    2017-05-01

    If millisecond pulsars (MSPs) are responsible for the excess gamma-ray emission observed from the region surrounding the Galactic Center, the same region should also contain a large population of low-mass X-ray binaries (LMXBs). In this study, we compile and utilize a sizable catalog of LMXBs observed in the the Milky Way's globular cluster system and in the Inner Galaxy, as well as the gamma-ray emission observed from globular clusters, to estimate the flux of gamma rays predicted from MSPs in the Inner Galaxy. From this comparison, we conclude that only up to $\\sim$4-23% of the observed gamma-ray excess is likely to originate from MSPs. This result is consistent with, and more robust than, previous estimates which utilized smaller samples of both globular clusters and LMXBs. If MSPs had been responsible for the entirety of the observed excess, INTEGRAL should have detected $\\sim$$10^3$ LMXBs from within a $10^{\\circ}$ radius around the Galactic Center, whereas only 42 LMXBs (and 46 additional LMXB candidates) have been observed.

  13. Westward tilt of low-latitude plasma blobs as observed by the Swarm constellation

    DEFF Research Database (Denmark)

    Park, Jaeheung; Luehr, Hermann; Michaelis, Ingo;

    2015-01-01

    In this study we investigate the three-dimensional structure of low-latitude plasma blobs using multi-instrument and multisatellite observations of the Swarm constellation. During the early commissioning phase the Swarm satellites were flying at the same altitude with zonal separation of about 0...

  14. Abrupt climate change and high to low latitude teleconnections as simulated in climate models

    DEFF Research Database (Denmark)

    Cvijanovic, Ivana

    High to low latitude atmospheric teleconnections have been a topic of increasing scientific interest since it was shown that high latitude extratropical forcing can induce tropical precipitation shifts through atmosphere-surface ocean interactions. In this thesis, several aspects of high to low l...

  15. Elosulfase alfa: first global approval.

    Science.gov (United States)

    Sanford, Mark; Lo, Jin Han

    2014-04-01

    Elosulfase alfa (Vimizim™) is a recombinant form of N-acetylgalactosamine-6-sulfatase (GALNS) that was developed by BioMarin Pharmaceutical Inc. as an enzyme replacement therapy for patients with mucopolysaccharidosis type IVA (MPS IVA), also known as Morquio A syndrome. Patients with MPS IVA have a GALNS deficiency, which results in serious musculoskeletal, cardiorespiratory and other system disturbances. Elosulfase alfa was approved by the US FDA on 14 February 2014 for the treatment of MPS IVA. The European Medicines Agency Committee for Medicinal Products for Human Use (CHMP) has recently recommended that elosulfase alfa be approved for use in the EU in the same indication. Within the last year, the manufacturer has also filed applications for approval for the use of elosulfase alfa in MPS IVA in Brazil, Australia, Canada and Mexico. This article summarizes the milestones in the development of elosulfase alfa leading to its first global approval in MPS IVA.

  16. On the Connection Between Solar Activity and Low-Latitude Aurorae in the Period 1715 - 1860

    Science.gov (United States)

    Vázquez, M.; Vaquero, J. M.; Curto, J. J.

    2006-11-01

    Observations of aurorae borealis at low latitudes are very rare and are clearly associated with strong geomagnetic storms. Morphologically, they are characterized by a diffuse red colour with no rapid motions. The main aim of this paper is to analyse two hitherto ignored aurorae that were observed at two low-latitude sites, Tenerife (28°N 18°W) and Mexico City (19°N 99°W), in 1770 and 1789, respectively. These observations can give supplementary information about the level of solar activity at those times where direct solar observations were rather scarce. Studying also the behaviour of the heliosphere during this period using different proxies, we find that the open magnetic field better describes auroral occurrences. The variation over time in geomagnetic latitude at the two sites is also calculated.

  17. Small-scale anisotropy and intermittency in high and low-latitude solar wind

    CERN Document Server

    Bigazzi, A; Gama, S M A; Velli, M

    2004-01-01

    We analyze low and high--latitude fast solar wind data from the Ulysses spacecraft from 1992 to 1994 using a a systematic method to analyse the anisotropic content of the magnetic field fluctuations. We investigate all available frequencies, 1-10^{-6} Hz, for both high and low--latitudes datasets and are able to quantify the relative importance of the anisotropic versus the isotropic fluctuations. We analyse, up to sixth order, longitudinal, transverse and mixed magnetic field correlations. Our results show that strongly intermittent and anisotropic events are present in the solar wind plasma at high frequencies/small scales, indicating the absence of a complete recovery of isotropy. Anisotropic scaling properties are compatible for high and low--latitude data, suggesting a universal behaviour in spite of the different rate of evolution of the fast solar wind streams in the two environments.

  18. On the cause of IMF By related mid- and low latitude magnetic disturbances

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne; Christiansen, Freddy; Olsen, Nils

    2007-01-01

    An analysis of the effect of the IMF By on near-Earth low and mid-latitude magnetic disturbances is presented. In particular the contribution from field-aligned currents ( FACs) connected to the polar regions is investigated. Based on statistically determined high-latitude FAC patterns for various...... Interplanetary Magnetic Field ( IMF) directions, we estimate the FAC contribution to the mid-and low latitude magnetic disturbance and its dependence on the IMF. The estimated perturbations are compared with observations from the ground and from the low-altitude polar orbiting satellite Oersted. It is found...... that the long-distance effect of the high-latitude FACs constitute the major source to IMF By and B-z related magnetic east-west disturbances at mid-and low latitudes....

  19. Post-Storm Middle and Low-Latitude Ionospheric Electric Fields Effects

    Science.gov (United States)

    Fejer, B. G.; Blanc, M.; Richmond, A. D.

    2016-12-01

    The Earth's upper atmosphere and ionosphere undergoes large and complex perturbations during and after geomagnetic storms. Thermospheric winds driven by enhanced energy and momentum due to geomagnetic activity generate large disturbance electric fields, plasma drifts and currents with a broad range of temporal and spatial scales from high to equatorial latitudes. This disturbance dynamo mechanism plays a fundamental role on the response of the middle and low-latitude ionosphere to geomagnetic activity. In this review, we initially describe the early evidence for the importance of this process and the first simulation study which already was able to explain its main effects on the electrodynamics of the middle and low-latitude ionosphere. We then describe the results of more recent simulations and the extensive experimental work that highlights the importance of this mechanism for ionospheric space weather studies extending to post-storms periods, and present some suggestions for future studies.

  20. Low latitude aurorae as a diagnostic for energetic particle injections and their environment

    Science.gov (United States)

    Thaller, S. A.; Wygant, J. R.; Dai, L.; Dombeck, J. P.; Cattell, C. A.; Mozer, F.; Russell, C. T.; Fennell, J. F.; Claudepierre, S. G.; Mende, S. B.; Frey, H. U.

    2012-12-01

    The region between the inner magnetosphere and the geomagnetic tail/plasma sheet is highly dynamic during geomagnetic storms and hosts many important magnetospheric phenomenon and structures, including particle injections and the outer radiation belt. The energy transport mechanisms in this region during major storms are not yet fully understood, however there is increasing evidence that in the range of invariant latitudes (ILAT) mapping to this dipole-tail boundary region, Alfven waves are an important energy source for the aurora. This range of latitudes, which is roughly 50 to 68 degrees ILAT varying somewhat on the level of magnetospheric disturbance, is low latitude for the aurora. We present a study of intense earthward Alfvenic Poynting flux at the location of, and concomitant with, energetic electron injections during dipolarizations, on field lines mapping to low latitude aurorae. The Poynting flux, when mapped to an ionospheric altitude of 100km, is of sufficient intensity to power the magnetically conjugate auroral luminosities. The preliminary results suggest that wave Poynting flux is an important link between injection events and low latitude aurorae. Thus the observation of the intensification and dynamic behavior of low latitude auroral arcs, i.e. those on field lines that during storms map to the near- tail boundary where particle injections are observed, are an important diagnostic for the occurrence, location, and plasma dynamics associated with energetic particle injections. This has important implications for the Radiation Belt Storm Probes (RBSP) mission. The data gathered by RBSP can be used in conjunction with auroral data from the THEMIS all-sky imaging array in Canada, providing a richer context for the study of radiation belt physics.

  1. Counter-streaming magnetosheath ions in the dayside low latitude boundary layer

    Science.gov (United States)

    Fuselier, S. A.; Klumpar, D. M.; Shelley, E. G.

    1992-01-01

    Observations in the subsolar low-latitude boundary layer (LLBL) during reconnection show counterstreaming suprathermal ions on rare occasions. Composition measurements for one event presented here indicate that the ions are from the magnetosheath although no similar equal energy per charge suprathermal He(2+) and H(+) populations were observed there. Acceleration of magnetosheath ions either across the magnetopause or in the LLBL followed by magnetic mirroring of the initially parallel suprathermal ions best explains these observations.

  2. East Asian Observations of Low Latitude Aurora during the Carrington Magnetic Storm

    CERN Document Server

    Hayakawa, Hisashi; Tamazawa, Harufumi; Isobe, Hiroaki; Kataoka, Ryuho; Ebihara, Yusuke; Miyahara, Hiroko; Kawamura, Akito Davis; Shibata, Kazunari

    2016-01-01

    The magnetic storm around 1859 September 2, caused by so-called Carrington flare, was the most intense in the history of modern scientific observations, and hence is considered to be the benchmark event for space weather. The magnetic storm caused worldwide observations of auroras even at very low latitudes such as Hawaii, Panama, or Santiago, and the available magnetic field measurement at Bombay, India, showed two peaks: the main was the Carrington event which occurred in day time in East Asia, and a second storm after the Carrington event which occurred at night in East Asia. In this paper, we present a result from surveys of aurora records in East Asia, which provides new information of the aurora activity of this important event. We found some new East Asian records of low latitude aurora observations caused by the storm which occurred after the Carrington event. The size of the aurora belt of the second peak of the Carrington magnetic storm was even wider than usual low-latitude aurora events.

  3. East Asian observations of low-latitude aurora during the Carrington magnetic storm

    Science.gov (United States)

    Hayakawa, Hisashi; Iwahashi, Kiyomi; Tamazawa, Harufumi; Isobe, Hiroaki; Kataoka, Ryuho; Ebihara, Yusuke; Miyahara, Hiroko; Kawamura, Akito Davis; Shibata, Kazunari

    2016-10-01

    A magnetic storm around 1859 September 2, caused by a so-called Carrington flare, was the most intense in the history of modern scientific observations, and hence is considered to be a benchmark event concerning space weather. The magnetic storm caused worldwide observations of auroras, even at very low latitudes, such as Hawaii, Panama, or Santiago. Available magnetic-field measurements at Bombay, India, showed two peaks: the main was the Carrington event, which occurred in day time in East Asia; a second storm after the Carrington event occurred at night in East Asia. In this paper, we present results from surveys of aurora records in East Asia, which provide new information concerning the aurora activity of this important event. We found some new East Asian records of low-latitude aurora observations caused by a storm which occurred after the Carrington event. The size of the aurora belt of the second peak of the Carrington magnetic storm was even wider than that of usual low-latitude aurora events.

  4. Ionospheric acoustic and gravity wave activity above low-latitude thunderstorms

    Energy Technology Data Exchange (ETDEWEB)

    Lay, Erin Hoffmann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-30

    In this report, we study the correlation between thunderstorm activity and ionospheric gravity and acoustic waves in the low-latitude ionosphere. We use ionospheric total electron content (TEC) measurements from the Low Latitude Ionospheric Sensor Network (LISN) and lightning measurements from the World- Wide Lightning Location Network (WWLLN). We find that ionospheric acoustic waves show a strong diurnal pattern in summer, peaking in the pre-midnight time period. However, the peak magnitude does not correspond to thunderstorm area, and the peak time is significantly after the peak in thunderstorm activity. Wintertime acoustic wave activity has no discernable pattern in these data. The coverage area of ionospheric gravity waves in the summer was found to increase with increasing thunderstorm activity. Wintertime gravity wave activity has an observable diurnal pattern unrelated to thunderstorm activity. These findings show that while thunderstorms are not the only, or dominant source of ionospheric perturbations at low-latitudes, they do have an observable effect on gravity wave activity and could be influential in acoustic wave activity.

  5. LION: A dynamic computer model for the low-latitude ionosphere

    Directory of Open Access Journals (Sweden)

    J. A. Bittencourt

    2007-11-01

    Full Text Available A realistic fully time-dependent computer model, denominated LION (Low-latitude Ionospheric model, that simulates the dynamic behavior of the low-latitude ionosphere is presented. The time evolution and spatial distribution of the ionospheric particle densities and velocities are computed by numerically solving the time-dependent, coupled, nonlinear system of continuity and momentum equations for the ions O+, O2+, NO+, N2+ and N+, taking into account photoionization of the atmospheric species by the solar extreme ultraviolet radiation, chemical and ionic production and loss reactions, and plasma transport processes, including the ionospheric effects of thermospheric neutral winds, plasma diffusion and electromagnetic E×B plasma drifts. The Earth's magnetic field is represented by a tilted centered magnetic dipole. This set of coupled nonlinear equations is solved along a given magnetic field line in a Lagrangian frame of reference moving vertically, in the magnetic meridian plane, with the electromagnetic E×B plasma drift velocity. The spatial and time distribution of the thermospheric neutral wind velocities and the pattern of the electromagnetic drifts are taken as known quantities, given through specified analytical or empirical models. The model simulation results are presented in the form of computer-generated color maps and reproduce the typical ionization distribution and time evolution normally observed in the low-latitude ionosphere, including details of the equatorial Appleton anomaly dynamics. The specific effects on the ionosphere due to changes in the thermospheric neutral winds and the electromagnetic plasma drifts can be investigated using different wind and drift models, including the important longitudinal effects associated with magnetic declination dependence and latitudinal separation between geographic and

  6. ALFA beam halo

    CERN Document Server

    Komarek, Tomas

    2014-01-01

    This note serves as a final report about CERN Summer Student Programme 2014 project. The beam halo is an undesired phenomenon for physics analyses on particle accelerators. It surrounds the beam core and constitutes an important part of background for signal measurements on some detectors, eg. in the forward region. In this study, the data from the ALFA detector were used, specifically from the run 191373 ($\\beta^*=90\\unit{m}$) and the run 213268 ($\\beta^*=1\\unit{km}$). Using the ROOT framework, a software for beam halo events selection was created and beam halo properties were examined. In the run 213268, excessive beam halo is suspected to be the reason for multiple beam scrapings that occurred. A kinematic reconstruction of beam halo particles is attempted in order to understand beam halo properties in the interaction point. Some further simulations are employed to find constraints for beam halo particles in order to survive in the accelerator for a longer time/many revolutions. This work represents a st...

  7. THE SEMI-GEOSTROPHIC ADAPTATION PROCESS WITH TWO-LAYER BAROCLINIC MODEL IN LOW LATITUDE ATMOSPHERE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, the adaptation process in low latitude atmosphere is discussed by means of a two-layer baroclinic model on the equator β plane, showing that the adaptation process in low latitude is mainly dominated by the internal inertial gravity waves. The initial ageostrophic energy is dispersed by the internal inertial gravity waves, and as a result, the geostrophic motion is obtained in zonal direction while the ageostrophic motion maintains in meridional direction, which can be called semi-geostrophic balance in barotropic model as well as semi-thermal-wind balance in baroclinic model. The vertical motion is determined both by the distribution of the initial vertical motion and that of the initial vertical motion tendency, but it is unrelated to the initial potential vorticity. Finally, the motion tends to be horizontal. The discussion of the physical mechanism of the semi-thermal-wind balance in low latitude atmosphere shows that the achievement of the semi-thermal-wind balance is due to the adjustment between the stream field and the temperature field through the horizontal convergence and divergence which is related to the vertical motion excited by the internal inertial gravity waves. The terminal adaptation state obtained shows that the adaptation direction between the mean temperature field and the shear flow field is determined by the ratio of the scale of the initial ageostrophic disturbance to the scale of one character scale related to the baroclinic Rossby radius of deformation. The shear stream field adapts to the mean temperature field when the ratio is greater than 1, and the mean temperature field adapts to the shear stream field when the ratio is smaller than 1.

  8. Analysis of propagation delays of compressional Pi 2 waves between geosynchronous altitude and low latitudes

    Science.gov (United States)

    Imajo, Shun; Yumoto, Kiyohumi; Uozumi, Teiji; Kawano, Hideaki; Abe, Shuji; Ikeda, Akihiro; Koga, Kiyokazu; Matsumoto, Haruhisa; Obara, Takahiro; Marshall, Richard; Akulichev, Victor A.; Mahrous, Ayman; Liedloff, Adam; Yoshikawa, Akimasa

    2014-12-01

    The propagation of compressional Pi 2 waves in the inner magnetosphere is investigated by analyzing the onset delay times between the ground and the geosynchronous altitude. We use the compressional component (northward) of magnetic data from low-latitude stations and the geosynchronous satellite ETS-VIII (GMLat. = -10.8°, GMLon. = 217.5°). The onset delays are determined by a cross-correlation analysis, and we analyzed the events with high waveform correlations (correlation coefficient greater than 0.75). Some of these high-correlation events have the properties of propagating waves; Pi 2 waveforms at the ground stations and the satellite were synchronized with each other when the data were shifted by onset delays. The results of the statistical analysis show that 87% of the Pi 2 onsets at a ground station (Kuju, GMLat. = 26.13°, GMLon. = 202.96°) were delayed from the Pi 2 onsets at ETS-VIII, and the average of the delay times was 29 sec. This clearly shows Pi 2 onsets (initial perturbations of Pi 2) propagated from the geosynchronous altitude to the low-latitude ground. The delay times tended to be larger around the midnight sector than around the dawn and dusk sectors. These results are consistent with two-dimensional propagation of fast waves estimated by the model of Uozumi et al. (J Geophys Res 114:A11207, 2009). The delay times are nearly identical to the travel time of fast waves from geosynchronous altitude to the low-latitude ground, and the local time variation of the delay shows the azimuthal propagation along the geosynchronous orbit. We conclude that the initial compressional perturbations of Pi 2 waves propagate radially and longitudinally as a fast wave in the inner magnetosphere.

  9. On the NH3 absorption depression observable at Northern low latitudes of Jupiter

    Science.gov (United States)

    Tejfel, Victor G.; Vdovichenko, Vladimir D.; Lysenko, Peter G.; Karimov, Alibek M.; Kirienko, Galina A.; Bondarenko, Natalya N.; Kharitonova, Galina

    2016-10-01

    From February to April of 2016, we carried out a special series of spectrophotometric observations of Jupiter to study the current behavior of the ammonia absorption at the low latitudes of the Northern hemisphere, where in 2004 we have found a well-defined depression of the 787 nm NH3 absorption band intensity (V.Tejfel et al., Bull.AAS, 2005, Vol. 37, p.682). In subsequent years, an existence of this depression was annually confirmed by spectral observations, although we were noticing its variable character. During observations of 2016 we obtained more than 2,500 CCD-spectrograms, including the spectra of the central meridian, the GRS, and 12 scans of Jovian disk on different dates (70 zonal spectra in each scan). The 787 nm NH3 absorption band was extracted with using of ratios of the Jovian spectra to the Saturn's disk spectrum that was taken as a reference. The depression of absorption in this band begins almost from the equator, and its maximum occurs at the planetographic latitude of 100N then the absorption increases again approaching to the latitude of 200N. The equivalent bandwidths corresponding to these latitudes are equal to 18.7 ± 1.4 A, 14.4 ± 1.0 A and 17.8 ± 0.8A. The 645 nm NH3 absorption band also shows depletion at the low latitudes of the Northern hemisphere, but it is less pronounced. At the temperate latitudes of the Northern hemisphere this band's absorption is systematically lower than the Southern Hemisphere's ones. We will continue research in this direction, especially because recently a significant depletion of gaseous NH3 has also been found with using of the VLA with high resolution (I. de Pater et al., Science, 2016, Vol. 352, Issue 6290, p.1290-1294) at the low latitudes of the Northern hemisphere in the region of the NEB.

  10. Analysis of local ionospheric variability based on SVD and MDS at low-latitude GNSS stations

    Science.gov (United States)

    Dabbakuti, J. R. K. Kumar; Devanaboyina, Venkata Ratnam; Kanchumarthi, S. Ramesh

    2016-06-01

    Investigation of ionospheric anomalies during equatorial and low latitude is of major concern for modeling and global navigation satellite system (GNSS) applications. Total electron content (TEC) varies with the ionospheric conditions, which will lead to the errors in the global positioning system (GPS) measurements. It is therefore a method that is necessary to characterize the ionospheric anomalies for satellite-based navigation systems. In this study, characterization of ionospheric variations based on the singular value decomposition (SVD) and classical multidimensional scaling (MDS) methods was studied. The yearly and daily variations are decomposed from the GPS-TEC, international reference ionosphere (IRI) 2007 and IRI 2012 models TEC over the three low-latitude GNSS stations located at Koneru Lakshmaiah University (KLU-Guntur), Hyderabad and Bangalore, respectively. From the results, it is found that there is a strong correlation between GPS-TEC and IRI models. The correlation coefficient for the first three singular values is more than 0.86. From this, it is possible to reconstruct more than 85 % of the variability contained in global GPS-derived VTEC data (for year 2013) by using only the first three modes. The semiannual variation has maximum value during March-April and September-October and has minimum value during June-July. It is observed that the annual variations have maximum value in summer and minimum value in winter, and the amplitudes decrease with increasing latitude. Further, opposite latitudinal asymmetry among annual and semiannual variations for three GNSS stations is noticed. SVD and MDS methods clearly show time-varying characteristics and the absence of the winter anomaly at low-latitude GNSS stations.

  11. The seasonal dependence of cycle slip occurrence of GPS data over China low latitude region

    Institute of Scientific and Technical Information of China (English)

    ZHANG DongHe; FENG Man; XIAO Zuo; HAO YongQiang; SHI LiQin; YANG GuangLin; SUO YuCheng

    2007-01-01

    The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip occurrence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the ionospheric irregularities over this region.

  12. The diffuse neutrino flux from the inner Galaxy: constraints from very high energy gamma-ray observations

    CERN Document Server

    Gabici, S; White, R J; Casanova, S; Aharonian, F A

    2008-01-01

    Recently, the MILAGRO collaboration reported on the detection of a diffuse multi-TeV emission from a region of the Galactic disk close to the inner Galaxy. The emission is in excess of what is predicted by conventional models for cosmic ray propagation, which are tuned to reproduce the spectrum of cosmic rays observed locally. By assuming that the excess detected by MILAGRO is of hadronic origin and that it is representative for the whole inner Galactic region, we estimate the expected diffuse flux of neutrinos from a region of the Galactic disk with coordinates $-40^{\\circ} < l < 40^{\\circ}$. Our estimate has to be considered as the maximal expected neutrino flux compatible with all the available gamma ray data, since any leptonic contribution to the observed gamma-ray emission would lower the neutrino flux. The diffuse flux of neutrinos, if close to the maximum allowed level, may be detected by a km$^3$--scale detector located in the northern hemisphere. A detection would unambiguously reveal the hadr...

  13. Chemical tagging with APOGEE: Discovery of a large population of N-rich stars in the inner Galaxy

    CERN Document Server

    Schiavon, Ricardo P; Carrera, Ricardo; Lucatello, Sara; Robin, A C; Ness, Melissa; Martell, Sarah L; Smith, Verne V; Hernandez, D A Garcia; Manchado, Arturo; Schoenrich, Ralph; Bastian, Nate; Chiappini, Cristina; Shetrone, Matthew; Mackereth, J Ted; Williams, Rob A; Meszaros, Szabolcs; Prieto, Carlos Allende; Anders, Friedrich; Bizyaev, Dmitry; Beers, Timothy C; Chojnowski, S Drew; Cunha, Katia; Epstein, Courtney; Frinchaboy, Peter M; Perez, Ana E Garcia; Hearty, Fred R; Holtzman, Jon A; Johnson, Jennifer A; Kinemuchi, Karen; Majewski, Steven R; Muna, Demitri; Nidever, David L; Nguyen, Duy Cuong; O'Connell, Robert W; Oravetz, Daniel; Pan, Kaike; Pinsonneault, Marc; Schneider, Donald P; Schultheis, Matthias; Simmons, Audrey; Skrutskie, Michael F; Sobeck, Jennifer; Wilson, John C; Zasowski, Gail

    2016-01-01

    Formation of globular clusters (GCs), the Galactic bulge, or galaxy bulges in general, are important unsolved problems in Galactic astronomy. Homogeneous infrared observations of large samples of stars belonging to GCs and the Galactic bulge field are one of the best ways to study these problems. We report the discovery by APOGEE of a population of field stars in the inner Galaxy with abundances of N, C, and Al that are typically found in GC stars. The newly discovered stars have high [N/Fe], which is correlated with [Al/Fe] and anti-correlated with [C/Fe]. They are homogeneously distributed across, and kinematically indistinguishable from, other field stars in the same volume. Their metallicity distribution is seemingly unimodal, peaking at [Fe/H]~-1, thus being in disagreement with that of the Galactic GC system. Our results can be understood in terms of different scenarios. N-rich stars could be former members of dissolved GCs, in which case the mass in destroyed GCs exceeds that of the surviving GC system...

  14. Carbon Recombination Lines toward the Riegel-Crutcher Cloud and other Cold HI Regions in the inner Galaxy

    CERN Document Server

    Roshi, D Anish

    2011-01-01

    We report here, for the first time, the association of low frequency CRRL with \\HI\\ self-absorbing clouds in the inner Galaxy and that the CRRLs from the innermost $\\sim 10^{\\circ}$ of the Galaxy arise in the Riegel-Crutcher (R-C) cloud. The R-C cloud is amongst the most well known of \\HI\\ self-absorbing (HISA) regions located at a distance of about 125 pc in the Galactic centre direction. Taking the R-C cloud as an example, we demonstrate that the physical properties of the HISA can be constrained by combining multi-frequency CRRL and \\HI\\ observations. The derived physical properties of the HISA cloud are used to determine the cooling and heating rates. The dominant cooling process is emission of the \\CII\\ 158 \\mum line whereas dominant heating process in the cloud interior is photoelectric emission. Constraints on the FUV flux (G0 $\\sim$ 4 to 7) falling on the R-C cloud are obtained by assuming thermal balance between the dominant heating and cooling processes. The H$_2$ formation rate per unit volume in t...

  15. Variations of n /sub e/h/ profiles and of vertical gradients at low latitudes during disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Goncharova, E.E.; Zevakina, R.A.; Palacio, L.

    1979-11-01

    The paper examines the electron density height profile and vertical gradients of electron density distribution as a function of the type and phase of ionospheric disturbances on the basis of data from the Cuban geophysical center for 1968. The difference between low-latitude height variations of electron density and those at midlatitudes is investigated, and possible causes of electron density height variations at low latitudes are discussed.

  16. Middle- and low-latitude ionosphere response to 2015 St. Patrick's Day geomagnetic storm

    Science.gov (United States)

    Nava, B.; Rodríguez-Zuluaga, J.; Alazo-Cuartas, K.; Kashcheyev, A.; Migoya-Orué, Y.; Radicella, S. M.; Amory-Mazaudier, C.; Fleury, R.

    2016-04-01

    This paper presents a study of the St Patrick's Day storm of 2015, with its ionospheric response at middle and low latitudes. The effects of the storm in each longitudinal sector (Asian, African, American, and Pacific) are characterized using global and regional electron content. At the beginning of the storm, one or two ionospheric positive storm effects are observed depending on the longitudinal zones. After the main phase of the storm, a strong decrease in ionization is observed at all longitudes, lasting several days. The American region exhibits the most remarkable increase in vertical total electron content (vTEC), while in the Asian sector, the largest decrease in vTEC is observed. At low latitudes, using spectral analysis, we were able to separate the effects of the prompt penetration of the magnetospheric convection electric field (PPEF) and of the disturbance dynamo electric field (DDEF) on the basis of ground magnetic data. Concerning the PPEF, Earth's magnetic field oscillations occur simultaneously in the Asian, African, and American sectors, during southward magnetization of the Bz component of the interplanetary magnetic field. Concerning the DDEF, diurnal magnetic oscillations in the horizontal component H of the Earth's magnetic field exhibit a behavior that is opposed to the regular one. These diurnal oscillations are recognized to last several days in all longitudinal sectors. The observational data obtained by all sensors used in the present paper can be interpreted on the basis of existing theoretical models.

  17. Low-latitude arc-continent collision as a driver for global cooling.

    Science.gov (United States)

    Jagoutz, Oliver; Macdonald, Francis A; Royden, Leigh

    2016-05-03

    New constraints on the tectonic evolution of the Neo-Tethys Ocean indicate that at ∼90-70 Ma and at ∼50-40 Ma, vast quantities of mafic and ultramafic rocks were emplaced at low latitude onto continental crust within the tropical humid belt. These emplacement events correspond temporally with, and are potential agents for, the global climatic cooling events that terminated the Cretaceous Thermal Maximum and the Early Eocene Climatic Optimum. We model the temporal effects of CO2 drawdown from the atmosphere due to chemical weathering of these obducted ophiolites, and of CO2 addition to the atmosphere from arc volcanism in the Neo-Tethys, between 100 and 40 Ma. Modeled variations in net CO2-drawdown rates are in excellent agreement with contemporaneous variation of ocean bottom water temperatures over this time interval, indicating that ophiolite emplacement may have played a major role in changing global climate. We demonstrate that both the lithology of the obducted rocks (mafic/ultramafic) and a tropical humid climate with high precipitation rate are needed to produce significant consumption of CO2 Based on these results, we suggest that the low-latitude closure of ocean basins along east-west trending plate boundaries may also have initiated other long-term global cooling events, such as Middle to Late Ordovician cooling and glaciation associated with the closure of the Iapetus Ocean.

  18. Detailed study of Pi2 damped oscillations from low latitude magnetic observatory

    Science.gov (United States)

    Bulusu, Jayashree; Arora, Kusumita; Nagarajan, Nandini

    2017-03-01

    The study of low latitude damped Pi2 oscillations (40-150 s) are investigated using archived data from Choutuppal (CPL), geomagnetic observatory, operated by CSIR-NGRI, Hyderabad, India. The period of investigation is during solar cycle 21 (1975-1983). All the Pi2 events identified during this period are subjected to detailed analysis for their association with substorm and non-substorm events. It is interesting to note that there is equal probability of occurrence of Pi2s with or without a substorm. The Pi2 frequencies associated with substorms showed an increased value in the post-midnight sector than compared to the Pre-midnight sectors. The non-substorm Pi2s are seen to be associated with lower levels of geomagnetic activity. The corresponding period of Pi2s decreases with increasing level of activity. While the generation of Pi2s are generally attributed to substorm onset, it is seen that the quiet time non-substorm events are related to plasmaspheric cavity mode resonances at low latitudes.

  19. International Comparison and Implications of Agricultural Development in Foreign Low Latitude Plateau Regions for Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    Yan; LUO; Yan; YANG; Rui; CHEN; Wei; WU; Ziyun; PENG; Liangzheng; CHEN; Xuelin; LI

    2013-01-01

    Climatic characteristics of foreign low latitude plateau regions are firstly introduced.Then,experience and lessons of major foreign low latitude plateau countries in developing modern agriculture are analyzed,including Indian three agricultural revolutions and agricultural informationization development,application of agricultural biotechnology in Brazil,trade liberalization and economic de-agriculture of Mexico,and Argentina,Saudi Arabia and South Africa attaching great importance to developing modern agriculture relying on science and technology and paying close attention to resource conservation and environmental protection.Combining natural and social resource characteristics of Yunnan plateau agriculture,pertinent implications and recommendations for modern agricultural development in Yunnan are put forward.Specifically,these include strengthening agricultural sci-tech research and development,and extension and application;transforming agricultural development model;enhancing agricultural resource conservation and environmental protection;accelerating developing mountain organic ecological agriculture and autumn agriculture;reinforcing urban and rural integration to develop plateau characteristic agriculture on the basis of local actual conditions.

  20. Discovery of a widespread low-latitude diurnal CO2 frost cycle on Mars

    Science.gov (United States)

    Piqueux, Sylvain; Kleinböhl, Armin; Hayne, Paul O.; Heavens, Nicholas G.; Kass, David M.; McCleese, Daniel J.; Schofield, John T.; Shirley, James H.

    2016-07-01

    While the detection of CO2 ice has only been reported outside the Martian polar regions at very high elevation (i.e., Elysium, Olympus Mons, and the Tharsis Montes), nighttime surface observations by the Mars Climate Sounder on board the Mars Reconnaissance Orbiter document the widespread occurrence of atmospherically corrected ground temperatures consistent with the presence of extensive carbon dioxide frost deposits in the dusty low thermal inertia units at middle/low latitudes. Thermal infrared emissivities, interpreted in conjunction with mass balance modeling, suggest micrometer size CO2 ice crystals forming optically thin layers never exceeding a few hundreds of microns in thickness (i.e., 10-2 kg m-2) locally, which is insufficient to generate a measurable diurnal pressure cycle (atmosphere). Atmospheric temperatures at middle/low latitudes are not consistent with precipitation of CO2 ice, suggesting that condensation occurs on the surface. The recurring growth and sublimation of CO2 ice on Martian dusty terrains may be an important process preventing soil induration and promoting dynamic phenomena (soil avalanching and fluidization and regolith gardening), maintaining a reservoir of micrometer size dust particles that are mobile and available for lifting. The discovery of this diurnal CO2 cycle represents an important step forward in our understanding of the way the Martian atmosphere interacts with the surface.

  1. Analytical study of nighttime scintillations using GPS at low latitude station Bhopal

    Energy Technology Data Exchange (ETDEWEB)

    Maski, Kalpana, E-mail: k-maski@rediffmail.com [Department of Physics, Regional Institute of Education, Bhopal (India); Vijay, S. K. [Institute for Excellence in Higher Education, Bhopal (India)

    2015-07-31

    Sporadically structured ionosphere (i.e. in-homogeneities in refractive index) can cause fluctuations (due to refraction effects) on the radio signal that is passing through it. These fluctuations are called ionospheric scintillations. Low latitude region is suitable for studying these scintillations. The influence of the ionosphere on the propagation of the radio wave becomes very marked with reference to communication or navigational radio system at very low frequency (VLF) to a high frequency (HF), which operate over the distances of 1000 km or more. Radio wave communication at different frequencies depends on structure of the ionosphere. With the advent of the artificial satellites, they are used as a prime mode of radio wave communication. Some natural perturbation termed as irregularities, are present in the form of electron density of the ionosphere that cause disruption in the radio and satellite communications. Therefore the study of the ionospheric irregularities is of practical importance, if one wishes to understand the upper atmosphere completely. In order to make these communications uninterrupted the knowledge of irregularities, which are present in the ionosphere are very important. These irregularities can be located and estimated with the help of Ionospheric TEC and Scintillation. Scintillation is generally confined to nighttime hours, particularly around equatorial and low latitudes.

  2. Multipoint Observations of Low Latitude ULF Pc3 Waves in South-East Australia

    Indian Academy of Sciences (India)

    I. A. Ansari

    2008-03-01

    Geomagnetic pulsations recorded on the ground are the signatures of the integrated signals from the magnetosphere. Pc3 geomagnetic pulsations are quasi-sinusoidal variations in the earth’s magnetic field in the period range 10–45 seconds. The magnitude of these pulsations ranges from fraction of a nT (nano Tesla) to several nT. These pulsations can be observed in a number of ways. However, the application of ground-based magnetometer arrays has proven to be one of the most successful methods of studying the spatial structure of hydromagnetic waves in the earth’s magnetosphere. The solar wind provides the energy for the earth’s magnetospheric processes. Pc3-5 geomagnetic pulsations can be generated either externally or internally with respect to the magnetosphere. The Pc3 studies undertaken in the past have been confined to middle and high latitudes. The spatial and temporal variations observed in Pc3 occurrence are of vital importance because they provide evidence which can be directly related to wave generation mechanisms both inside and external to the magnetosphere. At low latitudes (L < 3) wave energy predominates in the Pc3 band and the spatial characteristics of these pulsations have received little attention in the past. An array of four low latitude induction coil magnetometers were established in south-east Australia over a longitudinal range of 17 degrees at L = 1.8 to 2.7 for carrying out the study of the effect of the solar wind velocity on these pulsations. Digital dynamic spectra showing Pc3 pulsation activity over a period of about six months have been used to evaluate Pc3 pulsation occurrence. Pc3 occurrence probability at low latitudes has been found to be dominant for the solar wind velocity in the range 400–700 km/s. The results suggest that solar wind controls Pc3 occurrence through a mechanism in which Pc3 wave energy is convected through the magnetosheath and coupled to the standing oscillations of magnetospheric field lines.

  3. THE CISMON APTICORE (SOUTHERN ALPS, ITALY: A "REFERENCE SECTION " FOR THE LOWER CRETACEOUS AT LOW LATITUDES

    Directory of Open Access Journals (Sweden)

    ELISABETTA ERBA

    1998-07-01

    Full Text Available APTICORE at the Cismon Valley (Belluno Basin, Southern Alps penetrated 131.8 m of limestones, marlstones and "black shales". The cored interval extends from the Upper Aptian down to the lower Upper Hauterivian (about 117-130 Ma and can be considered a "reference section" for low latitudes. The hole was continuously cored with essentially 100% recovery of excellent quality material and completely logged with state-of-the art logging tools. Freshly cored material and logs from the Cismon drill site provide the most informative records for documenting and understanding global changes in the paleoenvironment, biota, geochemistry, paleotemperature of Early Cretaceous oceans. The following is a "site report" containing descriptions of the geologic setting, field operations, basic lithology and age information, and the logging tools and techniques. 

  4. E- and F- region incoherent scatter radar spectral measurements at mid and low-latitudes

    Science.gov (United States)

    Kudeki, Erhan; Milla, Marco

    2016-07-01

    In this talk we will contrast and compare incoherent scatter radar spectral measurements conducted using the Arecibo, ALTAIR, and Jicamarca incoherent scatter radars at ionospheric heights ranging from E-region into the topside F-region. Arecibo measurements from mid-latitudes exemplify high SNR ISR techniques utilized with large magnetic aspect angles. Low-latitude measurements at ALTAIR and Jicamarca make use of and combine large and small magnetic aspect angle techniques. Examples presented will include both natural and naturally enhanced electron and ion lines detected in the lower F region near the geomagnetic equator as well as the results of search for proton gyro-resonance peaks in the Jicamarca topside spectra.

  5. The seasonal dependence of cycle slip occurrence of GPS data over China low latitude region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip oc-currence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the iono-spheric irregularities over this region.

  6. Pc5 geomagnetic field fluctuations at discrete frequencies at a low latitude station

    Directory of Open Access Journals (Sweden)

    U. Villante

    Full Text Available A statistical analysis of the geomagnetic field fluctuations in the Pc5 frequency range (1–5 mHz at a low latitude station (L = 1.6 provides further evidence for daytime power peaks at discrete frequencies. The power enhancements, which become more pronounced during high solar wind pressure conditions, may be interpreted in terms of ground signatures of magnetospheric cavity/waveguide compressional modes driven by solar wind pressure pulses. In this sense, the much clearer statistical evidence for afternoon events can be related to corotating structures mainly impinging the postnoon magnetopause. A comparison with results obtained for the same time intervals from previous investigations at higher latitudes and in the Earth’s magnetosphere confirms the global character of the observed modes.

    Key words. Magnetospheric physics (MHD waves and instabilities; solar wind-magnetospheric interactions

  7. The Zambezi Channel: A new perspective on submarine channel evolution at low latitudes

    Science.gov (United States)

    Wiles, E.; Green, A.; Watkeys, M.; Jokat, W.

    2017-06-01

    Submarine channels are not stand-alone systems. They are long-lived systems modified by imperceptibly slow processes and rapid gravity flows, in some part controlled by hinterland dynamics. The submarine Zambezi Channel, within the Mozambique Channel, receives sediment from the Zambezi River catchment which has a dynamic tectonic and morphological history. Using recently collected multibeam bathymetry and PARASOUND data we discuss the geomorphology of the Zambezi Channel. Results show this system to be distinct in geomorphologic character when compared to other low-latitude submarine channels, sharing similarities with high-latitude systems. We propose a new, source-to-sink, hypothesis for the evolution of the Zambezi Channel, taking in to consideration hinterland tectonics, palaeo-lake development, river capture and rapid gravity flows. This hypothesis accounts for the unique present-day anatomy of the Zambezi Channel within the dynamic framework of the systems regional setting.

  8. Linear theory of the Kelvin-Helmholtz instability in the low-latitude boundary layer

    Science.gov (United States)

    Rajaram, R.; Sibeck, D. G.; Mcentire, R. W.

    1991-01-01

    The feasibility is examined of establishing characteristic profiles across the magnetospheric low-latitude boundary layer for the Kelvin-Helmholtz mode so that these profiles can be compared with satellite observations or a latitudinal chain of ground stations. An anisotropic collisionless fluid model is used instead of conventional MHD, and the finite thickness of the boundary layer and the thickness and position of the current layer are taken into account. The instability is found to be enhanced by a decrease in the thickness of the shear layer and of the current layer and by the proximity of the 'current layer' to the outer edge of the shear layer. The velocity threshold for the onset of instability is insensitive to the thickness. Characteristic profiles of the variation of plasma and field parameters across the boundary are obtained, and the importance of parameters specifying the current layer position and thickness is demonstrated.

  9. Chemical tagging with APOGEE: discovery of a large population of N-rich stars in the inner Galaxy

    Science.gov (United States)

    Schiavon, Ricardo P.; Zamora, Olga; Carrera, Ricardo; Lucatello, Sara; Robin, A. C.; Ness, Melissa; Martell, Sarah L.; Smith, Verne V.; García-Hernández, D. A.; Manchado, Arturo; Schönrich, Ralph; Bastian, Nate; Chiappini, Cristina; Shetrone, Matthew; Mackereth, J. Ted; Williams, Rob A.; Mészáros, Szabolcs; Allende Prieto, Carlos; Anders, Friedrich; Bizyaev, Dmitry; Beers, Timothy C.; Chojnowski, S. Drew; Cunha, Katia; Epstein, Courtney; Frinchaboy, Peter M.; García Pérez, Ana E.; Hearty, Fred R.; Holtzman, Jon A.; Johnson, Jennifer A.; Kinemuchi, Karen; Majewski, Steven R.; Muna, Demitri; Nidever, David L.; Nguyen, Duy Cuong; O'Connell, Robert W.; Oravetz, Daniel; Pan, Kaike; Pinsonneault, Marc; Schneider, Donald P.; Schultheis, Matthias; Simmons, Audrey; Skrutskie, Michael F.; Sobeck, Jennifer; Wilson, John C.; Zasowski, Gail

    2017-02-01

    Formation of globular clusters (GCs), the Galactic bulge, or galaxy bulges in general is an important unsolved problem in Galactic astronomy. Homogeneous infrared observations of large samples of stars belonging to GCs and the Galactic bulge field are one of the best ways to study these problems. We report the discovery by APOGEE (Apache Point Observatory Galactic Evolution Experiment) of a population of field stars in the inner Galaxy with abundances of N, C, and Al that are typically found in GC stars. The newly discovered stars have high [N/Fe], which is correlated with [Al/Fe] and anticorrelated with [C/Fe]. They are homogeneously distributed across, and kinematically indistinguishable from, other field stars within the same volume. Their metallicity distribution is seemingly unimodal, peaking at [Fe/H] ˜ -1, thus being in disagreement with that of the Galactic GC system. Our results can be understood in terms of different scenarios. N-rich stars could be former members of dissolved GCs, in which case the mass in destroyed GCs exceeds that of the surviving GC system by a factor of ˜8. In that scenario, the total mass contained in so-called `first-generation' stars cannot be larger than that in `second-generation' stars by more than a factor of ˜9 and was certainly smaller. Conversely, our results may imply the absence of a mandatory genetic link between `second-generation' stars and GCs. Last, but not least, N-rich stars could be the oldest stars in the Galaxy, the by-products of chemical enrichment by the first stellar generations formed in the heart of the Galaxy.

  10. A high-altitude balloon experiment to probe stratospheric electric fields from low latitudes

    Science.gov (United States)

    Gurubaran, Subramanian; Shanmugam, Manu; Jawahar, Kaliappan; Emperumal, Kaliappan; Mahavarkar, Prasanna; Buduru, Suneel Kumar

    2017-02-01

    The Earth's electrical environment hosts a giant electrical circuit, often referred to as the global electric circuit (GEC), linking the various sources of electrical generators located in the lower atmosphere, the ionosphere and the magnetosphere. The middle atmosphere (stratosphere and mesosphere) has been traditionally believed to be passively transmitting electric fields generated elsewhere. Some observations have reported anomalously large electric fields at these altitudes, and the scientific community has had to revisit the earlier hypothesis time and again. At stratospheric altitudes and especially at low latitudes, horizontal electric fields are believed to be of ionospheric origin. Though measurements of these fields from a balloon platform are challenging because of their small magnitudes (around a few mV m-1), a suitably designed long-duration balloon experiment capable of detecting such small fields can provide useful information on the time evolution of ionospheric electric fields, which is otherwise possible only using radar or satellite in situ measurements. We present herein details of one such experiment, BEENS (Balloon Experiment on the Electrodynamics of Near Space), carried out from a low-latitude site in India. The instrument package for this experiment is comprised of four deployable booms for measurements of horizontal electric fields and one inclined boom for vertical electric field measurements, all equipped with conducting spheres at the tip. The experiment was conducted from Hyderabad (17.5° N, 78.6° E) during the post-midnight hours on 14 December 2013. In spite of a few shortcomings we report herein, a noticeable feature of the observations has been the detection of horizontal electric fields of ˜ 5 mV m-1 at the stratospheric altitudes of ˜ 35 km.

  11. Trends of ionospheric irregularities over African low latitude region during quiet geomagnetic conditions

    Science.gov (United States)

    Mungufeni, Patrick; Habarulema, John Bosco; Jurua, Edward

    2016-02-01

    The occurrence patterns of ionospheric irregularities during quiet geomagnetic conditions over the African low latitude region were analysed. GNSS-derived Total Electron Content of the ionosphere data during the period 2001-2012 were used. The data were obtained from Libreville, Gabon (0.35°N, 9.68°E, geographic, 8.05°S, magnetic), Mbarara, Uganda (0.60°S, 30.74°E, geographic, 10.22°S, magnetic), and Malindi, Kenya (2.99°S, 40.19°E, geographic, 12.42°S, magnetic). The rate of change of total electron content index greater than 0.5 TECU/Min were considered as severe ionospheric irregularities. For most of the time, the strength of ionospheric irregularities in March equinox were greater than those during September equinox over East Africa and an opposite observation was made over West Africa. These asymmetries might be due to the direction of the meridional winds during equinoxes over the different stations. Severity of ionospheric irregularity reduced from west towards the east. This might have been related to the decreasing geomagnetic field strength from east towards the west. This is the first study that reveals the equinoctial asymmetry is different in the West and East African sectors. Moreover, the importance of this study lies in the fact that it has used extensive data to examine the isolated and un-explained earlier observations of equinoctial asymmetry and longitudinal variation of ionospheric irregularities over the African low latitude region.

  12. The first time observations of low-latitude ionospheric irregularities by VHF radar in Hainan

    Institute of Scientific and Technical Information of China (English)

    NING BaiQi; HU LianHuan; LI GuoZhu; LIU LiBo; WAN WeiXing

    2012-01-01

    Sanya VHF radar (18.4°N,109.6°E,dip latitude 12.8°N) at Hainan Island is the first coherent backscatter radar for sounding low-latitude ionospheric irregularities in the mainland of China.In this paper,we present the first results of low-latitude ionospheric E and F region irregularities using the radar data during the period from February 2009 to March 2010.The Doppler velocity of radar echoes from E region field aligned irregularities (FAIs) was about several tens of meters per second,while the Doppler spectral width was appreciably larger than the velocity,and could reach one hundred meters per second,indicating that the observed E region FAIs belonged to type 2 irregularities.The observations of range time intensity (RTI) maps of FAIs showed that E region irregularities most often occurred at night within the altitude range 85-115 km,and were rarely observed at afternoon hours.The percentage occurrence of E region FAIs maximized during spring months (Feb.-May) with a peak value over 80%.The heights at which the strongest echo related FAIs occurred were mainly around 100 km,lower than h'Es and the difference is mostly 10-20 km.December solstice seemed to be the minimum period of occurrence when the FAI echoes were commonly detected at a narrow altitude range 90-100 km.Moreover,simultaneous radar and GPS observations during spread F events in the pre-midnight hours of solar minimum revealed that significant GPS L band scintillations coincided with the appearance of F region plasma plume structures,which extended up to 450 km in altitude.

  13. Low-latitude Pi2 oscillations observed by polar Low Earth Orbiting satellite

    Science.gov (United States)

    Thomas, Neethal; Vichare, Geeta; Sinha, A. K.; Rawat, Rahul

    2015-09-01

    Low-latitude Pi2 pulsations in the topside ionosphere are investigated using vector magnetic field measurements from LEO satellite, CHAMP, and underneath ground station. Substorm-associated Pi2s are initially identified using high-resolution data from Indian station Shillong, during 2007-2009, and are further classified into three subgroups of Pi2 band (6-25 mHz), based on its frequency. During nighttime, coherent in-phase oscillations are observed in the compressional component at satellite and horizontal component at underneath ground station for all the Pi2 events, irrespective of the Pi2 frequency. We observe that the identification of daytime Pi2s at CHAMP (compressional component) depends on the frequency of Pi2 oscillation; i.e., 40%, 45%, and 100% of Pi2 events observed in dayside ground station with frequency between 6-10 mHz, 10-15 mHz, and 15-25 mHz were identified at satellite, respectively. At CHAMP during daytime, the presence of a dominant power in the lower frequencies of Pi2 band, which is unique to satellite, is consistently observed and can modify the Pi2 oscillations. Pi2s having frequency >15 mHz are less affected by these background frequencies, and a clear signature of daytime Pi2s at CHAMP is possible to observe, provided that contribution from non-Pi2 frequencies at satellite from the lower end of Pi2 band is eliminated. Daytime Pi2s identified in the topside ionosphere showed coherent but mostly opposite phase oscillations with underneath ground station, and satellite-to-ground amplitude ratio is, in general, found to be less than 1. Present results indicate that a combination of fast cavity-mode oscillations and an instantaneous transmission of Pi2 electric field from high- to low-latitude ionosphere is responsible for the observation of daytime Pi2s.

  14. Risk assessment of the extreme interplanetary shock of 23 July 2012 on low-latitude power networks

    Science.gov (United States)

    Zhang, J. J.; Wang, C.; Sun, T. R.; Liu, Y. D.

    2016-03-01

    Geomagnetic sudden commencements (SCs), characterized by a rapid enhancement in the rate of change of the geomagnetic field perturbation (dB/dt), are considered to be an important source of large geomagnetically induced currents (GICs) in middle- and low-latitude power grids. In this study, the extreme interplanetary shock of 23 July 2012 is simulated under the assumption that it had hit the Earth with the result indicating the shock-caused SC would be 123 nT. Based on statistics, the occurrence frequency of SCs with amplitudes larger than the simulated one is estimated to be approximately 0.2% during the past 147 years on the Earth. During this extreme event, the simulation indicates that dB/dt, which is usually used as a proxy for GICs, at a dayside low-latitude substation would exceed 100 nT/min; this is very large for low-latitude regions. We then assess the GIC threat level based on the simulated geomagnetic perturbations by using the method proposed by Marshall et al. (2011). The results indicate that the risk remains at "low" level for the low-latitude power network on a global perspective. However, the GIC risk may reach "moderate" or even "high" levels for some equatorial power networks due to the influence of the equatorial electrojet. Results of this study feature substantial implications for risk management, planning, and design of low-latitude electric power networks.

  15. Revisiting the question: Does high-latitude solar activity lead low-latitude solar activity in time phase?

    Energy Technology Data Exchange (ETDEWEB)

    Kong, D. F.; Qu, Z. N. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Guo, Q. L., E-mail: kdf@ynao.ac.cn [College of Mathematics Physics and Information Engineering, Jiaxing University, Jiaxing 314001 (China)

    2014-05-01

    Cross-correlation analysis and wavelet transform methods are used to investigate whether high-latitude solar activity leads low-latitude solar activity in time phase or not, using the data of the Carte Synoptique solar filaments archive from 1919 March to 1989 December. From the cross-correlation analysis, high-latitude solar filaments have a time lead of 12 Carrington solar rotations with respect to low-latitude ones. Both the cross-wavelet transform and wavelet coherence indicate that high-latitude solar filaments lead low-latitude ones in time phase. Furthermore, low-latitude solar activity is better correlated with high-latitude solar activity of the previous cycle than with that of the following cycle, which is statistically significant. Thus, the present study confirms that high-latitude solar activity in the polar regions is indeed better correlated with the low-latitude solar activity of the following cycle than with that of the previous cycle, namely, leading in time phase.

  16. OBSERVATIONAL STUDY OF MESO-β WAVE IN LOW LATITUDES OF SOUTH CHINA SEA OVER THE SUMMER MONSOON

    Institute of Scientific and Technical Information of China (English)

    余欲晓; 刘正奇

    2002-01-01

    The intensive observation data of the Nansha Islands are used to study and discuss the meso-and fine-scale systems existing with large-scale monsoon circulation during the onset of the southwesterly monsoon in the low-latitude areas of the South China Sea.Effects of low-latitude tropical meso-scale gravity waves on weather have been disclosed.The generation and transportation of the local meso-scale gravity wave have been preliminarily studied from the viewpoint of dynamics.

  17. The trophic structure and predation impact of a low latitude midwater fish assemblage

    Science.gov (United States)

    Hopkins, Thomas L.; Sutton, Tracey T.; Lancraft, Thomas M.

    The trophic ecology of a midwater fish assemblage was investigated in the eastern Gulf of Mexico, a regime exhibiting the principal physical-biological characteristics of oligotrophic low latitude ecosystems. In all, the diets of 164 species of midwater fishes were examined, with data for 121 being sufficient for analytical comparisons. Cluster analysis grouped the assemblage into 15 feeding guilds, with these falling into two major groups, those including zooplanktivores with largely crustacean diets, and those including predators on large prey, most of which were piscivores. Among the zooplanktivores, the principal predators were the Myctophidae, Sternoptychidae and Gonostomatidae which, respectively, consumed 31%, 27% and 14% of the food biomass eaten daily by the midwater fish assemblage. The myctophids alone accounted for 53% of the copepod and 40% of the euphausiid biomass ingested. The copepod genus Pleuromamma was especially important forage, constituting 40% of the copepod biomass consumed by the midwater fish assemblage. The Stomiidae were the dominant piscivores and accounted for 20% of the total food ingested daily and 61% of the fish eaten, with the majority of their prey being myctophids. Literature comparisons reveal that diet patterns for the eastern Gulf midwater assemblage closely resemble those for mid- to- low latitude oligotrophic regimes in general. Daily consumption of the entire assemblage is estimated at 2.5-4.3 kg C km -2 in the upper 1000 m. Four fifths of this is zooplankton while the balance is large prey, mostly fishes. The ingestion rate accounts for only 5-10% of the daily production of zooplankton, but 95% of fish daily production. While the latter is obviously an overestimate it does suggest a tighter nutritional coupling of the midwater fish assemblage with the upper trophic levels of the ecosystem than with zooplankton. Midwater fishes and shrimps, the two dominant groups of micronekton, together account for only 25% of

  18. How Strong is the Case for Proterozoic Low-Latitude Glaciation?

    Science.gov (United States)

    Evans, D. A.

    2004-05-01

    The most recent global compilations of paleomagnetic depositional latitudes for Proterozoic glaciogenic formations indicate a dominant mode near the paleo-equator (Evans 2000 AJS; Evans 2003 Tectonophysics). This result would therefore support either the snowball Earth or the large-obliquity hypotheses for Precambrian ice ages, but would reject the uniformitarian comparison to polar-temperate-restricted Phanerozoic glaciogenic deposits. The most reliable low-latitude results come from the Australian Marinoan succession, but a recent summary of these units has suggested that a glaciogenic origin is not yet demonstrated (Eyles and Januszczak 2004 Earth-Sci Reviews). It becomes useful, then, to review the global evidence for Proterozoic low-latitude glaciation. Eyles and Januszczak (ibid.) identified 13 Neoproterozoic deposits with "demonstrated" glacial influence. Among these, poor age constraints and lack of paleomagnetic data prohibit estimation of depositional paleolatitudes for the Fiq, Sturtian, Vreeland, Taoudeni, East Greenland, Port Askaig, and Zhengmuguan units. Moderate paleolatitudes are reasonably well supported for the South China, Gaskiers, Smalfjord, and Moelv units. Among the three remaining units, the Rapitan Group can be assigned a near-equatorial paleolatitude indirectly through use of the Galeros and Franklin-Natkusiak paleomagnetic results, as long as the Rapitan age lies within 750-720 Ma as generally expected. The Moonlight Valley Formation in northern Australia may be assigned a tropical paleolatitude according to high-quality paleomagnetic results from compellingly correlated Marinoan strata in southern Australia. Those strata, including the famous Elatina Formation, have yielded a robust paleomagnetic signature that is commonly interpreted to imply frigid climate (manifest in part by frost-wedge polygons) at near-equatorial latitudes. Concerns that the Neoproterozoic geomagnetic field was either nonaxial or nondipolar are valid in principle

  19. Analysis of ionosphere variability over low-latitude GNSS stations during 24th solar maximum period

    Science.gov (United States)

    Venkata Ratnam, D.; Sivavaraprasad, G.; Latha Devi, N. S. M. P.

    2017-07-01

    Global Positioning System (GPS) is a remote sensing tool of space weather and ionospheric variations. However, the interplanetary space-dependent drifts in the ionospheric irregularities cause predominant ranging errors in the GPS signals. The dynamic variability of the low-latitude ionosphere is an imperative threat to the satellite-based radio communication and navigation ranging systems. The study of temporal and spatial variations in the ionosphere has triggered new investigations in modelling, nowcasting and forecasting the ionospheric variations. Hence, in this paper, the dynamism in the day-to-day, month-to-month and seasonal variability of the ionospheric Total Electron Content (TEC) has been explored during the solar maximum period, January-December 2013, of the 24th solar cycle. The spatial and temporal variations of the ionosphere are analysed using the TEC values derived from three Indian low-latitude GPS stations, namely, Bengaluru, Guntur and Hyderabad, separated by 13-18° in latitude and 77-81° in longitude. The observed regional GPS-TEC variations are compared with the predicted TEC values of the International Reference Ionosphere (IRI-2012 and 2007) models. Ionospheric parameters such as Vertical TEC (VTEC), relative TEC deviation index and monthly variations in the grand-mean of ionosphere TEC and TEC intensity, along with the upper and lower quartiles, are adopted to investigate the ionosphere TEC variability during quiet and disturbed days. The maximum ionospheric TEC variability is found during March and September equinoxes, followed by December solstice while the minimum variability is observed during June solstice. IRI models are in reasonable agreement with GPS TEC but are overestimating during dawn hours (01:00-06:00 LT) as compared to the dusk hours. Higher percentage deviations are observed during equinoctial months than summer over EIA stations, Guntur and Hyderabad. GPS TEC variations are overestimated during dawn hours for all the

  20. Investigation of the outer and inner low-latitude boundary layers

    Directory of Open Access Journals (Sweden)

    T. M. Bauer

    Full Text Available We analyze 22 AMPTE/IRM crossings of the day-side low-latitude boundary layer for which a dense outer part can be distinguished from a dilute inner part. Whereas the plasma in the outer boundary layer (OBL is dominated by solar wind particles, the partial densities of solar wind and magnetospheric particles are comparable in the inner boundary layer (IBL. For 11 events we find a reasonable agreement between observed plasma flows and those predicted by the tangential stress balance of an open magnetopause. Thus, we conclude that, at least in these cases, the OBL is formed by a local magnetic reconnection. The disagreement with the tangential stress balance in the other 11 cases might be due to reconnection being time-dependent and patchy. The north-south component of the proton bulk velocity in the boundary layer is, on average, directed toward high latitudes for both low and high magnetic shear across the magnetopause. This argues clearly against the possibility that the dayside low-latitude boundary layer is populated with solar wind plasma primarily from the cusps. "Warm", counterstreaming electrons that originate primarily from the magnetosheath and have a field-aligned temperature that is higher than the electron temperature in the magnetosheath by a factor of 1–5, are a characteristic feature of the IBL. Profiles of the proton bulk velocity and the density of hot ring current electrons provide evidence that the IBL is on closed field lines. Part of the IBL may be on newly opened field lines. Using the average spectra of electric and magnetic fluctuations in the boundary layer, we estimate the diffusion caused by lower hybrid drift instability, gyroresonant pitch angle scattering, or kinetic Alfvén wave turbulence. We find that cross-field diffusion cannot transport solar wind plasma into the OBL or IBL at a rate that would account for the thickness ( ~ 1000 km of these sublayers. On the duskside, the dawn-dusk component of the proton

  1. First mesospheric turbulence study using coordinated rocket and MST radar measurements over Indian low latitude region

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, H.; Sinha, H.S.S.; Das, U.; Misra, R.N.; Das, S.R. [Physical Research Lab., Ahmedabad (India); Datta, J.; Chakravarty, S.C. [ISRO Headquarters, Bangalore (India); Patra, A.K.; Vekateswara Rao, N.; Narayana Rao, D. [National Atmospheric Research Lab., Tirupati (India)

    2008-07-01

    A campaign to study turbulence in the mesosphere, over low latitudes in India, using rocket-borne measurements and Indian MST radar, was conducted during July 2004. A rocket-borne Langmuir probe detected a spectrum of electron density irregularities, with scale sizes in the range of about 1 m to 1 km, in 67.5-78.0 km and 84-89 km altitude regions over a low latitude station Sriharikota (13.6 N, 80.2 E). A rocket-borne chaff experiment measured zonal and meridional winds about 30 min after the Langmuir probe flight. The MST radar located at Gadanki (13.5 N, 79.2 E), which is about 100 km west of Sriharikota, also detected the presence of a strong scattering layer in 73.5-77.5 km region from which radar echoes corresponding to 3 m irregularities were received. Based on the region of occurrence of irregularities, which was highly collisional, presence of significant shears in zonal and meridional components of wind measured by the chaff experiment, 10 min periodicity in zonal and meridional winds obtained by the MST radar and the nature of wave number spectra of the irregularities, it is suggested that the observed irregularities were produced through the neutral turbulence mechanism. The percentage amplitude of fluctuations across the entire scale size range showed that the strength of turbulence was stronger in the lower altitude regions and decreased with increasing altitude. It was also found that the amplitude of fluctuations was large in regions of steeper electron density gradients. MST radar observations showed that at smaller scales of turbulence such as 3 m, (a) the thickness of the turbulent layer was between 2 and 3 km and (b) and fine structures, with layer thicknesses of about a km or less were also embedded in these layers. Rocket also detected 3-m fluctuations, which were very strong (a few percent) in lower altitudes (67.5 to 71.0 km) and small but clearly well above the noise floor at higher altitudes. Rocket and radar results also point to the

  2. Isotopic composition of low-latitude paleoprecipitation during the Early Cretaceous

    Science.gov (United States)

    Suarez, M.B.; Gonzalez, Luis A.; Ludvigson, Greg A.; Vega, F.J.; Alvarado-Ortega, J.

    2009-01-01

    likely underestimated tropical to subtropical precipitation and evaporation fluxes. The limited latitudinal constraints for earlier isotope mass balance modeling of the Albian hydrologic cycle of the Northern Hemisphere Americas resulted in extrapolated low-latitude precipitation ??18O values that were much heavier (up to 3???) than the values observed in this study. The lighter values identified in this study indicate a more pronounced rainout effect for tropical regions and quite possibly a more vigorous evaporation effect. These and additional low-latitude data are required to better constrain changes in the hydrologic cycle during the Cretaceous greenhouse period, and to reduce the uncertainties resulting from limited geographic coverage of proxy data. ?? 2009 Geological Society of America.

  3. First mesospheric turbulence study using coordinated rocket and MST radar measurements over Indian low latitude region

    Directory of Open Access Journals (Sweden)

    H. Chandra

    2008-09-01

    Full Text Available A campaign to study turbulence in the mesosphere, over low latitudes in India, using rocket-borne measurements and Indian MST radar, was conducted during July 2004. A rocket-borne Langmuir probe detected a spectrum of electron density irregularities, with scale sizes in the range of about 1 m to 1 km, in 67.5–78.0 km and 84–89 km altitude regions over a low latitude station Sriharikota (13.6° N, 80.2° E. A rocket-borne chaff experiment measured zonal and meridional winds about 30 min after the Langmuir probe flight. The MST radar located at Gadanki (13.5° N, 79.2° E, which is about 100 km west of Sriharikota, also detected the presence of a strong scattering layer in 73.5–77.5 km region from which radar echoes corresponding to 3 m irregularities were received. Based on the region of occurrence of irregularities, which was highly collisional, presence of significant shears in zonal and meridional components of wind measured by the chaff experiment, 10 min periodicity in zonal and meridional winds obtained by the MST radar and the nature of wave number spectra of the irregularities, it is suggested that the observed irregularities were produced through the neutral turbulence mechanism. The percentage amplitude of fluctuations across the entire scale size range showed that the strength of turbulence was stronger in the lower altitude regions and decreased with increasing altitude. It was also found that the amplitude of fluctuations was large in regions of steeper electron density gradients. MST radar observations showed that at smaller scales of turbulence such as 3 m, (a the thickness of the turbulent layer was between 2 and 3 km and (b and fine structures, with layer thicknesses of about a km or less were also embedded in these layers. Rocket also detected 3-m fluctuations, which were very strong (a few percent in lower altitudes (67.5 to 71.0 km and small but clearly well above the noise floor at higher altitudes. Rocket and radar

  4. Linking sulfate and phyllosilicate formation at Mawrth Vallis: Weathering in ancient low-latitude ice deposits

    Science.gov (United States)

    Niles, P. B.; Michalski, J.

    2009-12-01

    A currently outstanding question in martian geology is the mechanism by which large and numerous deposits of sulfate-rich and phyllosilicate-rich sedimentary rocks were generated. Hypotheses proposed to explain the origin of layered, sulfate-rich sediments at Meridiani Planum include: a) alteration by acidic fluids in a shallow and intermittently wet groundwater/playa/sebkha system, b) alteration of volcanic ash-flows by acidic sulfur-rich gases, c) reworking of sulfate-rich material by impact base surge, and d) acidic weathering within massive low-latitude ice deposits. We favor the ice-weathering model because this scenario can best explain the geologic and geochemical observations made from orbit and the surface. In addition, this model is in accord with an emerging picture of Mars in which ice-related processes have driven many aspects of sedimentation through time. The ice weathering model may also be relevant for understanding the origin of phyllosilicate deposits located beneath the sulfate-rich deposits at Meridiani Planum as well as at Mawrth Vallis. The Mawrth Vallis phyllosilicate deposits have several special characteristics: they are laterally extensive - occurring within stratigraphic windows over >~2*106 km2, and the mineralogical stratigraphy is the same everywhere that they are observed (Al-phyllosilicates overlying Fe/Mg-phyllosilicates). These observations can only be explained by a process that operated on a large spatial scale, just as with the sulfate deposits at Meridiani. However, if there were in fact massive ice deposits at low latitudes as called for in the Meridiani ice-weathering model, basal melting of these deposits may have driven a large regional groundwater system. Groundwater derived from extensive basal melting would likely have been alkaline due to increased water-rock interaction and increased dilution of the acid present in the ice deposit. Thus, the mineralogical stratigraphy could be explained by this alkaline groundwater

  5. A theoretical model for mid- and low-latitude ionospheric electric fields in realistic geomagnetic fields

    Institute of Scientific and Technical Information of China (English)

    REN ZhiPeng; WAN WeiXing; WEI Yong; LIU LiBo; YU Tao

    2008-01-01

    The geomagnetic fields, which play important roles in the ionospheric dynamo, can greatly affect the global distribution of ionospheric electric fields, currents and other ionospheric electrodynamics phenomena. In the study of ionospheric electrodynamics phenomena, such as the longitudinal variations of ionospheric electric fields, the non-dipolar component of the geomagnetic fields must be taken into account. In this paper, we deduce a theoretical electric field model for ionospheric dynamo at midand low-latitude which adopt a modified magnetic apex coordinates system. In the new electric field model, the geomagnetic fields can be calculated from either the IGRF model or the dipole field model,and the neutral winds and conductivities are calculated based on empirical models. Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method, and the ionospheric electric fields and currents are derived from the calculated potential. Our model can reproduce the main features of the ionospheric electrodynamics processes, so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.

  6. High-latitude controls of thermocline nutrients and low latitude biological productivity.

    Science.gov (United States)

    Sarmiento, J L; Gruber, N; Brzezinski, M A; Dunne, J P

    2004-01-01

    The ocean's biological pump strips nutrients out of the surface waters and exports them into the thermocline and deep waters. If there were no return path of nutrients from deep waters, the biological pump would eventually deplete the surface waters and thermocline of nutrients; surface biological productivity would plummet. Here we make use of the combined distributions of silicic acid and nitrate to trace the main nutrient return path from deep waters by upwelling in the Southern Ocean and subsequent entrainment into subantarctic mode water. We show that the subantarctic mode water, which spreads throughout the entire Southern Hemisphere and North Atlantic Ocean, is the main source of nutrients for the thermocline. We also find that an additional return path exists in the northwest corner of the Pacific Ocean, where enhanced vertical mixing, perhaps driven by tides, brings abyssal nutrients to the surface and supplies them to the thermocline of the North Pacific. Our analysis has important implications for our understanding of large-scale controls on the nature and magnitude of low-latitude biological productivity and its sensitivity to climate change.

  7. Effect of Magnetic Activity on Ionospheric Time Delay at Low Latitude

    Indian Academy of Sciences (India)

    Soumi Bhattacharya; Smita Dubey; Rajesh Tiwari; P. K. Purohit; A. K. Gwal

    2008-03-01

    The purpose of this work is to investigate the effect of magnetic activity on ionospheric time delay at low latitude Station Bhopal (geom. lat. 23.2°N, geom. long. 77.6°E) using dual frequency (1575.42 and 1227.60 MHz) GPS measurements. Data from GSV4004A GPS Ionospheric Scintillation and TEC monitor (GISTM) have been chosen to study these effects. This paper presents the results of ionospheric time delay during quiet and disturbed days for the year 2005. Results show that maximum delay is observed during quiet days in equinoxial month while the delays of disturbed period are observed during the months of winter. We also study the ionospheric time delay during magnetic storm conditions for the same period. Results do not show any clear relationship either with the magnitude of the geomagnetic storm or with the main phase onset (MPO) of the storm. But most of the maximum ionospheric time delay variations are observed before the main phase onset (MPO) or sudden storm commencement (SSC) as compared to storm days.

  8. Climatology of ionosphere over low-latitude (Kolkata) using FORMOSAT-3/COSMIC satellite observation

    Indian Academy of Sciences (India)

    Gopal Mondal; Manojit Gupta; Goutam Kumar Sen

    2015-03-01

    We have analyzed the diurnal, monthly, and seasonal variation in NmF2, HmF2, and IECs parameters derived from the COSMIC-RO observation over the low-latitude (Kolkata) region during 2008–2012 and compared the result with the IRI-2007 model output. In general, during HSA period the seasonal averaged model outcome prominently overestimates the observed values throughout the day, except HmF2, while in LSA period it is confined to post-noon hours. The differences between diurnal-dip and diurnal-peak values of all these parameters are considerably higher in the model outcomes than those of observed values, especially during increasing solar activity. In addition, the monthly averaged NmF2, BIEC, and TIEC values at noon and midnight, obtained from the both options, exhibit semi-annual variation, which are in good agreement with some earlier studies, whereas HmF2 shows annual variability for all solar activity. Moreover, the similarities and dissimilarities observed in variation pattern, particularly during 2011 and 2012, can help the research community to understand the recent trends of ionospheric parameters and develop the IRI model with more efficiency to fit the observed profile in a better way.

  9. Some unusual discrete VLF emissions observed at a low-latitude ground station at Agra

    Directory of Open Access Journals (Sweden)

    B. Singh

    Full Text Available A detailed analysis of the VLF emissions data obtained during occasional whistler campaigns at the low-latitude ground station Agra (geomagnetic latitude 17°1' N, L = 1.15 has yielded some unusual discrete VLF emissions of the rising type. These include (1 emissions occurring at time intervals increasing in ge ommetrical progression, (2 emissions occuring simulta neously in different frequency ranges and (3 emissions observed during daytime. In the present study, the observed characteristics of these emissions are described and interpreted. It is shown that the increasing time delay between different components of the emissions match closely with the propagation time delays between different hops of a whistler of dispersion 19 s1/2, the unusual occurrence of the emissions in two different frequency ranges approximately at the same time may possibly be linked with their generation at two different locations, and the occurrence of emissions during daytime may be due to propagation under the influence of equatorial anomaly.

  10. Simultaneous high- and low-latitude reconnection: ESR and DMSP observations

    Directory of Open Access Journals (Sweden)

    F. Pitout

    Full Text Available We present EISCAT Svalbard Radar and DMSP observations of a double cusp during an interval of predominantly northward IMF on 26 November 2000. In the cusp region, the ESR dish, pointing northward, recorded sun-ward ionospheric flow at high latitudes (above 82° GL, indicating reconnection occuring in the magnetospheric lobe. Meanwhile, the same dish also recorded bursts of poleward flow, indicative of bursty reconnection at the subsolar magnetopause. Within this time interval, the DMSP F13 satellite passed in the close vicinity of the Svalbard archipelago. The particle measurement on board exhibited a double cusp structure in which two oppositely oriented ion dispersions are recorded. We interpret this set of data in terms of simultaneous merging at low- and high-latitude magnetopause. We discuss the conditions for which such simultaneous high-latitude and low-latitude reconnection can be anticipated. We also discuss the consequences of the presence of two X-lines in the dayside polar ionosphere.

    Key words. Magnetospheric physics (solar wind-magnetosphere interactions – Ionosphere (polar ionosphere; plasma convection

  11. Phenomenology of the low-latitude ionosphere during northern winter and association with sudden stratospheric warmings

    Science.gov (United States)

    Goncharenko, L. P.; Coster, A. J.; Benkevitch, L. V.; Yudin, V. A.

    2014-12-01

    Large number of recent studies has demonstrated strong anomalies in the low-latitude ionosphere during sudden stratospheric warmings (SSW) that occur primarily during the northern winter period (December-February). Such events occurred with unusually high frequency during the last decade, making it possible to take advantage of increasingly available GPS TEC data to make significant progress in studies of atmosphere-ionosphere coupling. We focus on the American longitudinal sector, where good quality GPS TEC data is available for extended period of time, and examine three wintertime (November - February) periods marked by major sudden stratospheric warmings, 2005/06, 2008/09, and 2012/13. The selected events represent wide variety of stratospheric and geophysical conditions, including a vortex-shift (wave 1) SSW during solar minimum (2005/06), vortex-split (wave 2) SSW during extreme solar minimum (2008/09), and vortex-split (wave 2) SSW during moderate-to-high solar activity. To clearly separate ionospheric anomalies associated with SSW from other types of variations, we also examine the winter of 2006/07, which was characterized by less disturbed middle atmosphere. Comparison of ionospheric disturbances for three SSW cases shows remarkably consistent response to all events, albeit with varying magnitude. This response has primarily a tidal character and lasts for extended period of time. WACCM-X simulations of these events demonstrate amplification in global tidal energy for all major tides (diurnal, semidiurnal, terdiurnal), with strongest enhancement of semidiurnal tide.

  12. Surface-temperature trends and variability in the low-latitude North Atlantic since 1552

    KAUST Repository

    Saenger, Casey

    2009-06-21

    Sea surface temperature variability in the North Atlantic Ocean recorded since about 1850 has been ascribed to a natural multidecadal oscillation superimposed on a background warming trend1-6. It has been suggested that the multidecadal variability may be a persistent feature6-8, raising the possibility that the associated climate impacts may be predictable7,8. owever, our understanding of the multidecadal ocean variability before the instrumental record is based on interpretations of high-latitude terrestrial proxy records. Here we present an absolutely dated and annually resolved record of sea surface temperature from the Bahamas, based on a 440-year time series of coral growth rates. The reconstruction indicates that temperatures were as warm as today from about 1552 to 1570, then cooled by about 1° C from 1650 to 1730 before warming until the present. Our estimates of background variability suggest that much of the warming since 1900 was driven by anthropogenic forcing. Interdecadal variability with a period of 15-25 years is superimposed on most of the record, but multidecadal variability becomes significant only after 1730. We conclude that the multidecadal variability in sea surface temperatures in the low-latitude western Atlantic Ocean may not be persistent, potentially making accurate decadal climate forecasts more difficult to achieve. © 2009 Macmillan Publishers Limited. All rights reserved.

  13. The possible statistical relation of Pc1 pulsations to Earthquake occurrence at low latitudes

    Directory of Open Access Journals (Sweden)

    J. Bortnik

    2008-09-01

    Full Text Available We examine the association between earthquakes and Pc1 pulsations observed at a low-latitude station in Parkfield, California. The period under examination is ~7.5 years in total, from February 1999 to July 2006, and we use an automatic identification algorithm to extract information on Pc1 pulsations from the magnetometer data. These pulsations are then statistically correlated to earthquakes from the USGS NEIC catalog within a radius of 200 km around the magnetometer, and M>3.0. Results indicate that there is an enhanced occurrence probability of Pc1 pulsations ~5–15 days in advance of the earthquakes, during the daytime. We quantify the statistical significance and show that such an enhancement is unlikely to have occurred due to chance alone. We then examine the effect of declustering our earthquake catalog, and show that even though significance decreases, there is still a statistically significant daytime enhancement prior to the earthquakes. Finally, we select only daytime Pc1 pulsations as the fiducial time of our analysis, and show that earthquakes are ~3–5 times more likely to occur in the week following these pulsations, than normal. Comparing these results to other events, it is preliminarily shown that the normal earthquake probability is unaffected by geomagnetic activity, or a random event sequence.

  14. Large-scale plasma bubbles in the low-latitude ionosphere

    Energy Technology Data Exchange (ETDEWEB)

    Bittencourt, J.A.; Sahai, Y.; Fagundes, P.R.; Takahashi, H.

    1994-01-01

    Plasma irregularities in the low-latitude ionospheric F-layer resulting from plasma instability processes have been the subject of intensive experimental and theoretical research in the past few years. The morphology and dynamics of transequatorial ionospheric plasma bubbles and smaller scale plasma irregularities can be monitored through observations of the intensities of the 630.0 nm and 777.4 nm atomic oxygen nightglow emissions arising from ionospheric recombination processes. Simultaneous north-south meridional scanning observations of these OI emissions, using ground-based scanning filter photometers, as well as observations of the OI 630.0 nm emission using an all-sky imaging system, have been made at Cachoeira Paulista (22.7 deg S, 45.0 deg W, dip latitude 15.8 deg S) during both quiet and magnetically disturbed conditions, as well as in the presence of large scale field-aligned ionospheric plasma depletions. Some results of this long series of photometer and all-sky imaging observations are presented and their significant features are analyzed and discussed.

  15. Multispectral optical observations of ionospheric F-region storm effects at low latitude

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, Y.; Bittencourt, J.A.; Takahashi, H.; Teixeira, N.R.; Sobral, J.H.A.; Tinsley, B.A.; Rohrbaugh, R.P.

    1988-04-01

    Simultaneous measurements of specified nightglow emissions have been carried out at Cachoeira Paulista, since 1982, to study the response of the low-latitude ionospheric F-region to magnetic storms. The observations obtained during three magnetic storms in Brazil in 1983 and 1984 are presented and discussed. Emissions excited by energetic particle precipitation were observed during the main phase of strong magnetic storms. In contrast to the observations reported from mid-latitude stations by other investigators, no enhancements in the OI 7774 A emission due to energetic particle precipitation were evident at our latitude. Radiative recombination is suggested as the main excitation mechanism. The OI 6300 A emission, on 7-8 August and 28-29 March, showed periodic intensity variations, which are associated with vertical oscillations of the ionospheric F-region plasma, as shown by the periodic height variations of the F-region seen from the ionograms obtained at the same location. Also, the North-South scanning observation of this wavelength on one occasion showed no meridional and longitudinal phase change, indicating the absence of propagation.

  16. Dynamics of turbulent western-boundary currents at low latitude in a shallow-water model

    Science.gov (United States)

    Akuetevi, C. Q. C.; Wirth, A.

    2015-06-01

    The dynamics of low latitude turbulent western-boundary currents (WBCs) crossing the Equator are considered using numerical results from integrations of a reduced-gravity shallow-water model. For viscosity values of 1000 m2 s-1 and greater, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in the form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer, VSL) and dipoles appear. Three distinct boundary layers emerge, the VSL, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity; the second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse-resolution numerical models is proposed.

  17. Investigation of Ionospheric Response to Geomagnetic Storms over a Low Latitude Station, Ile-Ife, Nigeria

    Science.gov (United States)

    Jimoh, Oluwaseyi E.; Yesufu, Thomas K.; Ariyibi, Emmanuel A.

    2016-06-01

    Due to several complexities associated with the equatorial ionosphere, and the significant role which the total electron content (TEC) variability plays in GPS signal transmission, there is the need to monitor irregularities in TEC during storm events. The GPS SCINDA receiver data at Ile-Ife, Nigeria, was analysed with a view to characterizing the ionospheric response to geomagnetic storms on 9 March and 1 October 2012. Presently, positive storm effects, peaks in TEC which were associated with prompt penetration of electric fields and changes in neutral gas composition were observed for the storms. The maximum percentage deviation in TEC of about 120 and 45% were observed for 9 March and 1 October 2012, respectively. An obvious negative percentage TEC deviation subsequent to sudden storm commencement (SSC) was observed and besides a geomagnetic storm does not necessarily suggest a high scintillation intensity (S4) index. The present results show that magnetic storm events at low latitude regions may have an adverse effect on navigation and communication systems.

  18. Some evidence of ground power enhancements at frequencies of global magnetospheric modes at low latitude

    Directory of Open Access Journals (Sweden)

    P. Francia

    Full Text Available A statistical analysis of the power spectra of the geomagnetic field components H and D for periods ranging between 3 min and 1 h was conducted at a low-latitude observatory (L'Aquila, L=1.6 at the minimum and maximum of the solar cycle. For both components, during daytime intervals, we found evidence of power enhancements at frequencies predicted for global modes of the Earth's magnetosphere and occasionally observed at auroral latitudes in the F-region drift velocities (approximately at 1.3, 1.9, 2.6, and 3.4 mHz. Nighttime observations reveal a relative low frequency H enhancement associated with the bay occurrence together with a peak in the H/D power ratio which sharply emerges at 1.2 mHz in the premidnight sector. The strong similarity between solar minimum and maximum suggests that these modes can be considered permanent magnetospheric features. A separate analysis on a two-month interval shows that the observed spectral characteristics are amplified by conditions of high-velocity solar wind.

  19. Surface-temperature trends and variability in the low-latitude North Atlantic since 1552

    Science.gov (United States)

    Saenger, Casey; Cohen, Anne L.; Oppo, Delia W.; Halley, Robert B.; Carilli, Jessica E.

    2009-07-01

    Sea surface temperature variability in the North Atlantic Ocean recorded since about 1850 has been ascribed to a natural multidecadal oscillation superimposed on a background warming trend. It has been suggested that the multidecadal variability may be a persistent feature, raising the possibility that the associated climate impacts may be predictable. However, our understanding of the multidecadal ocean variability before the instrumental record is based on interpretations of high-latitude terrestrial proxy records. Here we present an absolutely dated and annually resolved record of sea surface temperature from the Bahamas, based on a 440-year time series of coral growth rates. The reconstruction indicates that temperatures were as warm as today from about 1552 to 1570, then cooled by about 1∘C from 1650 to 1730 before warming until the present. Our estimates of background variability suggest that much of the warming since 1900 was driven by anthropogenic forcing. Interdecadal variability with a period of 15-25years is superimposed on most of the record, but multidecadal variability becomes significant only after 1730. We conclude that the multidecadal variability in sea surface temperatures in the low-latitude western Atlantic Ocean may not be persistent, potentially making accurate decadal climate forecasts more difficult to achieve.

  20. HF Doppler radar observations of sporadic E at an Indian low latitude station, Visakhapatnam

    Directory of Open Access Journals (Sweden)

    M. S. S. R. K. N Sarma

    2009-02-01

    Full Text Available 5.5 MHz HF Doppler radar observations of Sporadic E over an Indian low latitude station, Visakhapatnam (17.7° N, 83.3° E and Dip 20° with 10 s resolution showed quasi-periodic variations of the echo strength and Doppler velocity variations with periods of a few minutes to a few tens of minutes. The echo strength and Doppler velocity variations with time in different range bins of the ES echo showed variations which are some times similar and some times significantly different in successive range bins at intervals of 7.5 km. The ES echo occurs with the height of maximum echo strength in the range of 100 km to 120 km and some times at 130 km. The altitude variation of the average Doppler velocity is highly variable and the height of maximum echo strength is not the same as the height of maximum Doppler velocity. Observations of ES echoes at different times of the day are presented to bring out the differences between the day and night time ES echoes. The relationship between Radar and ES parameters derived from Ionograms is poorer than that of mid latitudes which is quite consistent with the expectations based on gradient drift instability.

  1. Performance of ionospheric maps in support of long baseline GNSS kinematic positioning at low latitudes

    Science.gov (United States)

    Park, J.; Sreeja, V.; Aquino, M.; Cesaroni, C.; Spogli, L.; Dodson, A.; De Franceschi, G.

    2016-05-01

    Ionospheric scintillation occurs mainly at high and low latitude regions of the Earth and may impose serious degradation on GNSS (Global Navigation Satellite System) functionality. The Brazilian territory sits on one of the most affected areas of the globe, where the ionosphere behaves very unpredictably, with strong scintillation frequently occurring in the local postsunset hours. The correlation between scintillation occurrence and sharp variations in the ionospheric total electron content (TEC) in Brazil is demonstrated in Spogli et al. (2013). The compounded effect of these associated ionospheric disturbances on long baseline GNSS kinematic positioning is studied in this paper, in particular when ionospheric maps are used to aid the positioning solution. The experiments have been conducted using data from GNSS reference stations in Brazil. The use of a regional TEC map generated under the CALIBRA (Countering GNSS high-Accuracy applications Limitations due to Ionospheric disturbances in BRAzil) project, referred to as CALIBRA TEC map (CTM), was compared to the use of the Global Ionosphere Map (GIM), provided by the International GNSS Service (IGS). Results show that the use of the CTM greatly improves the kinematic positioning solution as compared with that using the GIM, especially under disturbed ionospheric conditions. Additionally, different hypotheses were tested regarding the precision of the TEC values obtained from ionospheric maps, and its effect on the long baseline kinematic solution evaluated. Finally, this study compares two interpolation methods for ionospheric maps, namely, the Inverse Distance Weight and the Natural Neighbor.

  2. Combined Impedance Probe and Langmuir Probe Studies of the Low-Latitude E Region

    Science.gov (United States)

    Rowland, D. E.; Pfaff, R. F.; Steigies, C. T.

    2008-01-01

    The EQUIS-2 sounding rocket and radar campaign, launched from Kwajalein Atoll in 2004, included a mission to study low-latitude irregularities and electrodynamics, led by NASA GSFC. This mission included two instrumented rockets launched into the nighttime E region (apogee near 120 km), which included comprehensive electrodynamics and neutral density instrumentation. These rockets carried the first of a new generation of impedance probes, that utilize a wide-band drive signal to simultaneously measure the impedance of an antenna in a plasma as a function of frequency from 7 kEIz to 4 MHz. at a rapid cadence. This technique promises to permit true plasma spectroscopy, and resulted in the identification of multiple plasma resonances and accurate measurements of the plasma density, even in the low density nighttime E region. We present analyses of the technique and resulting spectra, and show how these data may be combined with fixed-bias Langmuir Probe data to infer the temperature structure of the E region as well as providing accurate absolute calibrations for the very high time resolution fixed-bias probe data. The data is shown to agree well with data from ionosonde, the ALTAIR radar, and the Peruvian beacon experiment.

  3. Low-latitude climate variability in the Heinrich frequency band of the Late Cretaceous Greenhouse world

    Directory of Open Access Journals (Sweden)

    N. J. de Winter

    2013-08-01

    Full Text Available Deep marine successions of early Campanian age from DSDP site 516F drilled at low paleolatitudes in the South Atlantic reveal distinct sub-Milankovitch variability in addition to precession and eccentricity related variations. Elemental abundance ratios point to a similar climatic origin for these variations and exclude a quadripartite structure – as observed in the Mediterranean Neogene – of the precession related cycles as an explanation for the inferred semi-precession cyclicity in MS. However, the semi-precession cycle itself is likely an artifact, reflecting the first harmonic of the precession signal. The sub-Milankovitch variability is best approximated by a ~ 7 kyr cycle as shown by spectral analysis and bandpass filtering. The presence of sub-Milankovitch cycles with a period similar to that of Heinrich events of the last glacial cycle is consistent with linking the latter to low-latitude climate change caused by a non-linear response to precession induced variations in insolation between the tropics.

  4. Spectroscopic confirmation of the low-latitude object FSR 1716 as an old globular cluster

    Science.gov (United States)

    Koch, Andreas; Kunder, Andrea; Wojno, Jennifer

    2017-09-01

    Star clusters are invaluable tracers of the Galactic components and the discovery and characterization of low-mass stellar systems can be used to appraise their prevailing disruption mechanisms and time scales. However, owing to significant foreground contamination, high extinction, and still uncharted interfaces of the underlying Milky Way components, objects at low Galactic latitudes are notoriously difficult to characterize. Here, we present the first spectroscopic campaign to identify the chemodynamical properties of the low-latitude star cluster FSR 1716. While its photometric age and distance are far from settled, the presence of RR Lyrae variables indicates a rather old cluster variety. Using medium-resolution (R 10 600) calcium triplet (CaT) spectroscopy obtained with the wide-field, multi-fiber AAOmega instrument, we identified six member candidates with a mean velocity of -30 km s-1 and a velocity dispersion of 2.5 ± 0.9 km s-1. The latter value implies a dynamic mass of 1.3 × 104M⊙, typical of a low-mass globular cluster. Combined with our derived CaT metallicity of -1.38 ± 0.20 dex, this object is finally confirmed as an old, metal-poor globular cluster.

  5. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-11-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents crossing the equator is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and more, the boundary layer dynamics compares well to the analytical Munk-layer solution. When the viscosity is reduced, the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. Characteristic scales of the dynamics and dissipation are determined. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  6. Dynamics of turbulent western boundary currents at low latitude in a shallow water model

    Directory of Open Access Journals (Sweden)

    C. Q. C. Akuetevi

    2014-03-01

    Full Text Available The dynamics of low latitude turbulent western boundary currents, subject to two different types of idealized wind forcing, Monsoon Wind and Trade Wind, is considered using numerical results from integrations of a reduced gravity shallow-water model. For viscosity values of 1000 m2 s−1 and above, the boundary layer dynamics compares well to the analytical solutions of the Munk-layer and the inertial-layer, derived from quasigeostrophic theory. Modifications due to variations in the layer thickness (vortex stretching are only important close to the boundary. When the viscosity is reduced the boundary layer becomes turbulent and coherent structures in form of anticyclonic eddies, bursts (violent detachments of the viscous sub-layer and dipoles appear. Three distinct boundary layers emerge, the viscous sub-layer, the advective boundary layer and the extended boundary layer. The first is characterized by a dominant vorticity balance between the viscous transport and the advective transport of vorticity. The second by a balance between the advection of planetary vorticity and the advective transport of relative vorticity. The extended boundary layer is the area to which turbulent motion from the boundary extends. The scaling of the three boundary layer thicknesses with viscosity is evaluated. A pragmatic approach to determine the eddy viscosity diagnostically for coarse resolution numerical models is proposed.

  7. Insights into low-latitude cloud feedbacks from large-eddy simulations

    Science.gov (United States)

    Bretherton, Christopher; Blossey, Peter

    2017-04-01

    Cloud feedbacks are a leading source of uncertainty in the climate sensitivity simulated by global climate models (GCMs). Low-latitude boundary-layer and cumulus cloud regimes are particularly problematic, because they are sustained by tight interactions between clouds and unresolved turbulent circulations. Large-eddy simulations (LES) using sub-100 m grid spacings better simulate such cloud regimes without need for complex models of subgrid variability of cloud and turbulence. Recently, multiday LES over small computational domains have elucidated marine boundary layer cloud response to specified aspects of greenhouse warming and the associated changes in large-scale dynamics and atmospheric radiative heating. The focus will be the CGILS LES intercomparisons and subsequent related work. Four primary contributing mechanisms of subtropical low cloud response are implicated, all with observational support. These are (1) thermodynamic: cloudiness reduction from warming and moistening of the atmosphere-ocean column, (2) radiative: cloudiness reduction from CO2 and H2O-induced increase in atmospheric emissivity aloft, (3) stability-induced: low cloud increase from increased lower-tropospheric stratification, and (4) dynamical: low cloud increase from reduced subsidence. LES as a group robustly suggest that the cloudiness reduction mechanisms typically dominate, giving positive shortwave cloud feedback in the subtropics consistent with the range simulated by conventional global climate models. Finally, a possible approach for better bridging the scale gap between LES and global models will be noted.

  8. ANALYSIS OF AMBIENT FIELDS AND SATELLITE IMAGERY CHARACTERISTICS OF EFFECT OF BAY OF BENGAL STORMS ON LOW-LATITUDE PLATEAU

    Institute of Scientific and Technical Information of China (English)

    XU Mei-ling; ZHANG Xiu-nian; YANG Su-yu

    2007-01-01

    Based on the composite analysis method, 12 rainstorms triggered by Bay of Bengal storms(shortened as B-storms hereafter) across the whole province of Yunnan were studied, and some interesting results of rain and circulation characteristics influenced by the storms were obtained for low-latitude plateau.Usually, when a rainstorm weather occurs in low-latitude plateau, the B-storm center locates in the central,east or north parts of the Bay of Bengal. At the same time, the subtropical high ridge moves to 15°N - 20°Nand the west ridge point moves to the Indo-china Peninsula from the South China Sea and the low-latitude plateau is controlled by southwest air streams coming from the front of the trough and the periphery of the subtropical high. The southwest low-level jet stream from the east side of the bay storm has great effect on heavy rains. On the one hand, the southwest low-level jet stream is playing the role of transporting water vapor and energy. On the other hand, the southwest low-level jet stream is helpful to keep essential dynamical condition. From the analysis of the satellite cloud imagery, it is found that mesoscale convection cloud clusters will keep growing and moving into the low-latitude plateau to cause heavy rains when a storm forms in the Bay of Bengal.

  9. Effect of magnetic activity on plasma bubbles over equatorial and low-latitude regions in East Asia

    Directory of Open Access Journals (Sweden)

    G. Li

    2009-01-01

    Full Text Available The dependence of plasma bubble occurrence in the eveningside ionosphere, with magnetic activity during the period years 2001–2004, is studied here based on the TEC observations gathered by ground-based GPS receivers which are located in the equatorial and low-latitude regions in East Asia. The observed plasma bubbles consist of the plasma-bubble events in the equatorial (stations GUAM, PIMO and KAYT, and low-latitude regions (stations WUHN, DAEJ and SHAO. It is shown that most equatorial plasma-bubble events commence at 20:00 LT, and may last for >60 min. The magnetic activity appears to suppress the generation of equatorial plasma bubbles with a time delay of more than 3 h (4–9 h. While in the low-latitude regions, most plasma-bubble events commence at about 23:00 LT and last for <45 min. The best correlation between Kp and low-latitude plasma-bubble occurrence is found with an 8–9 h delay, a weak correlation exists for time delays of 6–7 h. This probably indicates that over 3 h delayed disturbance dynamo electric fields obviously inhibit the development of plasma bubbles in the pre-midnight sector.

  10. Responses of the low-latitude ionosphere to very intense geomagnetic storms

    Science.gov (United States)

    Sobral, J. H. A.; Abdu, M. A.; Yamashita, C. S.; Gonzalez, W. D.; de Gonzalez, A. C.; Batista, I. S.; Zamlutti, C. J.; Tsurutani, B. T.

    2001-01-01

    In this work, we investigate the ionospheric responses to exceptionally high-intensity and long-duration magnetic storms over Brazil. Disturbed ionospheric F-region vertical drifts and peak electron density changes observed at the equatorial station Fortaleza - Fz (/3°55'S /38°25'W /dip-3.5°) and the low-latitude station Cachoeira Paulista - CP /(22°41'S /45°00'W dip24°S), for three magnetospheric storm events that occurred in December 1980, April 1981 and September 1982, are analyzed. These storms had minimum Dst indexes /-240,-311 and /-289nT, respectively. The interplanetary magnetic field (Bz) data from the ISEE-3 satellite, the auroral activity index AE, and the ring current index Dst are used as indicators of the magnetospheric conditions. The ionospheric response features are analyzed using the F-layer critical parameters h'F, hpF2 and foF2, from ionograms obtained at Fz and CP. The Bz and the AE index variations were much higher than those in many previous studies. Therefore, many of the observations reported here either have not been observed or are not readily explained by current models for predicting the penetration//dynamo disturbance electric fields. The altitude of the nocturnal ionospheric F-layer at low latitudes may undergo significant variations during storm-time, caused by magnitude variations on the local zonal component of the F-region electric field intensity. During the period studied here, clear association of the F-layer rise (vertical velocity and altitude) and spread-F occurrence is observed. It is shown that the storm-time layer rise has a dominant role on the equatorial spread-F. An attempt is made to identify the origin of electric fields responsible for the disturbed F-layer alterations. The main conclusions of this study are that (a) some effects on the F-layer height and peak electron concentrations are consistent with model predictions. Some others are in discrepancy or have not been either predicted by model studies or

  11. Day-to-day variability of geomagnetic hourly amplitudes at low latitudes

    Science.gov (United States)

    Okeke, F. N.; Agodi Onwumechili, C.; Rabiu, Babatunde A.

    1998-08-01

    A study of the variability of the amplitude of Sq at a fixed hour from one day to the next at nine stations from the dip equator to about 22° north of it has produced interesting results. The amplitude and sign of the variability change virtually randomly, making the mean practically zero. The variability occurs at all hours of the day. Its magnitudes in the components D, H and Z have the same diurnal variation, which peaks in the noon period like Sq(H) in low latitudes, and a weak seasonal variation that peaks at the June solstice (local summer). It is demonstrated that changes in the current intensities of the equatorial electrojet (EEJ) and the worldwide part of the Sq (WSq) current layers have contrasting phases and can sometimes be in antiphase. Indeed, the changes are mostly independent. Inclusion of the magnetic element D revealed that the EEJ current system has not only an east-west but also a north-south component. The study shows that the meridional component of the EEJ current intensity evidenced at the Kodaikanal and Annamalainagar stations is an integral part of the zonal component at Trivandrum. This confirms the results of Rastogi (1996) and validates those of Onwumechili (1997). The results suggest that ionospheric conductivity mainly controls the magnitude, while the electric field and ultimately winds mainly control the phase and randomness of the day-to-day variability of the hourly amplitudes of Sq. The random component is attributed to local and/or regional atmospheric winds, probably of gravity wave origin.

  12. Modelling of ionospheric irregularities during geomagnetic storms over African low latitude region

    Science.gov (United States)

    Mungufeni, Patrick

    2016-07-01

    In this study, empirical models of occurrence of ionospheric irregularities over low latitude African region during geomagnetic storms have been developed. The geomagnetic storms considered consisted of Dst ≤ -50 nT. GNSS-derived ionospheric Total Electron Content (TEC) data over Libreville, Gabon (NKLG) (0.35° N, 9.68° E, geographic, 8.05° S, magnetic) and Malindi, Kenya (MAL2) (2.99° S, 40.19° E, geographic, 12.42° S, magnetic) during 2000 - 2014 were used. Ionospheric irregularities at scale- lengths of a few kilometers and ˜400 m were represented with the rate of change of TEC index (ROTI). The inputs for the models are the local time, solar flux index, Auroral Electrojet index, day of the year, and the Dst index, while the output is the median ROTI during these given conditions. To develop the models, the ROTI index values were binned based on the input parameters and cubic B splines were then fitted to the binned data. Developed models using data over NKLG and MAL2 were validated with independent data over stations within 510 km and 680 km radius, respectively. The models captured the enhancements and inhibitions of the occurrence of the ionospheric irregularities during the storm period. The models even emulated these patterns in the various seasons, during medium and high solar activity conditions. The correlation coefficients for the validations were statistically significant and ranged from 0.58 - 0.73, while the percentage of the variance in the observed data explained by the modelled data ranged from 34 - 53.

  13. Space Weather Studies Using the Low-Latitude Ionospheric Sensor Network (LISN)

    Science.gov (United States)

    Valladares, C. E.; Pacheco, E.

    2014-12-01

    LISN is an array of small instruments that operates as a real-time distributed observatory to understand the complex day-to-day variability and the extreme state of disturbance that occurs in the South American low-latitude ionosphere nearly every day after sunset. The LISN observatory aims to forecast the initiation and transport of plasma bubbles across the South American continent. The occurrence of this type of plasma structures and their embedded irregularities poses a prominent natural hazard to communication, navigation and high precision pointing systems. As commercial and military aviation is increasingly reliant on Global Navigation Satellite Systems (GNSS) any interruption due to ionospheric irregularities or errors due to large density gradients constitutes a serious threat to passengers and crew. Therefore, it is important to understand the conditions and sources that contribute to the formation of these irregularities. To achieve high quality regional nowcasts and forecasts, the LISN system was designed to include a dense coverage of the South American landmass with 47 GPS receivers, 5 flux-gate magnetometers distributed on 2 base lines and 3 Vertical Incidence Pulsed Ionospheric Radar (VIPIR) ionosondes deployed along the same magnetic meridian that intersects the magnetic equator at 68° W. This presentation will provide a summary of recent instrument installations and new processing techniques that have been developed under the LISN project. We will also present the results of recent efforts to detect TIDs and TEC plasma depletions on a near real-time basis. We will describe a method to estimate the zonal velocity and tilt of the plasma bubbles/depletions by combining observations of TEC depletions acquired with adjacent receivers, making it possible to predict precisely their future locations.

  14. Annual and seasonal variations in the low-latitude topside ionosphere

    Directory of Open Access Journals (Sweden)

    Y. Z. Su

    Full Text Available Annual and seasonal variations in the low-latitude topside ionosphere are investigated using observations made by the Hinotori satellite and the Sheffield University Plasmasphere Ionosphere Model (SUPIM. The observed electron densities at 600 km altitude show a strong annual anomaly at all longitudes. The average electron densities of conjugate latitudes within the latitude range ±25° are higher at the December solstice than at the June solstice by about 100 during daytime and 30 during night-time. Model calculations show that the annual variations in the neutral gas densities play important roles. The model values obtained from calculations with inputs for the neutral densities obtained from MSIS86 reproduce the general behaviour of the observed annual anomaly. However, the differences in the modelled electron densities at the two solstices are only about 30 of that seen in the observed values. The model calculations suggest that while the differences between the solstice values of neutral wind, resulting from the coupling of the neutral gas and plasma, may also make a significant contribution to the daytime annual anomaly, the E×B drift velocity may slightly weaken the annual anomaly during daytime and strengthen the anomaly during the post-sunset period. It is suggested that energy sources, other than those arising from the 6 difference in the solar EUV fluxes at the two solstices due to the change in the Sun-Earth distance, may contribute to the annual anomaly. Observations show strong seasonal variations at the solstices, with the electron density at 600 km altitude being higher in the summer hemisphere than in the winter hemisphere, contrary to the behaviour in NmF2. Model calculations confirm that the seasonal behaviour results from effects caused by transequatorial component of the neutral wind in the direction summer hemisphere to winter hemisphere.

  15. Evaluation of olive flowering at low latitude sites in Argentina using a chilling requirement model

    Energy Technology Data Exchange (ETDEWEB)

    Aybar, V.E.; Melo-Abreu, J.P. de; Searles, P.S.; Matias, A.G.; Del Rio, C.; Caballero, C. M.; Rousseaux, M.C.

    2015-07-01

    Olive production has expanded significantly from the Mediterranean Basin into the New World over the last two decades. In some cases, cultivars of European origin have been introduced at a large commercial scale with little previous evaluation of potential productivity. The objective of this study was to evaluate whether a temperature-driven simulation model developed in the Mediterranean Basin to predict normal flowering occurrence and flowering date using cultivar-specific thermal requirements was suitable for the low latitude areas of Northwest Argentina. The model was validated at eight sites over several years and a wide elevation range (350–1200 m above mean sea level) for three cultivars (‘Arbequina’, ‘Frantoio’, ‘Leccino’) with potentially different chilling requirements. In ‘Arbequina’, normal flowering was observed at almost all sites and in all years, while normal flowering events in ‘Frantoio’ and ‘Leccino’ were uncommon. The model successfully predicted if flowering would be normal in 92% and 83% of the cases in ‘Arbequina’ and ‘Frantoio’, respectively, but was somewhat less successful in ‘Leccino’ (61%). When flowering occurred, the predicted flowering date was within ± 7 days of the observed date in 71% of the cases. Overall, the model results indicate that cultivar-specific simulation models may be used as an approximate tool to predict whether individual cultivars will be successful in new growing areas. In Northwest Argentina, the model could be used to identify cultivars to replace ‘Frantoio’ and ‘Leccino’ and to simulate global warming scenarios. (Author)

  16. Holocene biomass burning recorded in polar and low-latitude ice cores

    Science.gov (United States)

    Kehrwald, N. M.; Zennaro, P.; Zangrando, R.; Gabrielli, P.; Thompson, L. G.; Gambaro, A.; Barbante, C.

    2011-12-01

    Ice cores contain specific molecular markers including levoglucosan (1,6-anhydro-β-D-glucopyranose) and other pyrochemical evidence that provides much-needed information on the role of fire in regions with no existing data of past fire activity. Levoglucosan is a cellulose combustion product produced at burning temperatures of 300°C or greater. We first trace fire emissions from a boreal forest source in the Canadian Shield through transport and deposition at Summit, Greenland. Atmospheric and surface samples suggest that levoglucosan in snow can record biomass burning events up to 1000s of kilometers away. Levoglucosan does degrade by interacting with hydroxyl radicals in the atmosphere, but it is emitted in large quantities, allowing the use as a biomass burning tracer. These quantified atmospheric biomass burning emissions and associated parallel oxalate and levoglucosan peaks in snow pit samples validates levoglucosan as a proxy for past biomass burning in snow records and by extension in ice cores. The temporal and spatial resolution of chemical markers in ice cores matches the core in which they are measured. The longest temporal resolution extends back approximately eight glacial cycles in the EPICA Dome C ice core, but many ice cores provide high-resolution Holocene records. The spatial resolution of chemical markers in ice cores depends on the core location where low-latitude ice cores primarily reflect regional climate parameters, and polar ice cores integrate hemispheric signals. Here, we compare levoglucosan flux measured during the late Holocene in the Kilimanjaro (3°04.6'S; 37°21.2'E, 5893 masl) and NEEM, Greenland (77°27' N; 51°3'W, 2454 masl) ice cores. We contrast the Holocene results with levoglucosan flux across the past 600,000 years in the EPICA Dome C (75°06'S, 123°21'E, 3233 masl) ice core.

  17. Climatology of low latitude F-region irregularities using GPS radio occultation data

    Science.gov (United States)

    Kepkar, Ankur; Arras, Christina; Wickert, Jens

    2017-04-01

    Since the presence of electrons in the upper atmosphere affects radio waves, GNSS signals which operate at radio frequencies result in weak signal strength at reception. Such affected signals can be associated with the Signal-to-Noise (SNR) to study disturbances which are caused by irregularities in the Earth's ionosphere. For this study we use data obtained by the GPS radio occultation method, a satellite-satellite remote sensing technique. The general idea of this method is to track the GPS radio signal, as it passes through the Earth's atmosphere crossing Earth's limb. This weather independent method provides global coverage, high accuracy and a high vertical resolution. Due to the refraction of the GPS electromagnetic waves induced by electron density gradients in ionospheric altitudes, the GPS signals contain information on current ionospheric conditions. The study mainly focuses on providing a climatology of disturbances at low latitude region of the ionosphere taking into account the measurements obtained from FORMOSAT-3/COSMIC (2006-2013). We use GPS L1 profiles tracked in 1Hz mode which scans the Earth's atmosphere with an altitude resolution of 2km. Strong SNR fluctuations are referred to vertical changes in the electron density. The six FORMOSAT-3/COSMIC satellites provide in total about 2,000 radio occultation profiles per day on an average. About 5 millions of profiles were processed for this study, of which 0.16% contain strong disturbances in the ionospheric F-region. We observed that the F-region irregularity phenomenon occurs mainly at night time close to the Earth's magnetic equator during years with high solar activity. Distinctive seasonal variations can be seen from such investigations when analyzed for different years of data. This phenomenon is traditionally explained as a consequence of plasma instability.

  18. Some evidence of ground power enhancements at frequencies of global magnetospheric modes at low latitude

    Science.gov (United States)

    Francia, P.; Villante, U.

    1997-01-01

    A statistical analysis of the power spectra of the geomagnetic field components H and D for periods ranging between 3 min and 1 h was conducted at a low-latitude observatory (LÁquila, L=1.6) at the minimum and maximum of the solar cycle. For both components, during daytime intervals, we found evidence of power enhancements at frequencies predicted for global modes of the Earthś magnetosphere and occasionally observed at auroral latitudes in the F-region drift velocities (approximately at 1.3, 1.9, 2.6, and 3.4 mHz). Nighttime observations reveal a relative low frequency H enhancement associated with the bay occurrence together with a peak in the H/D power ratio which sharply emerges at 1.2 mHz in the premidnight sector. The strong similarity between solar minimum and maximum suggests that these modes can be considered permanent magnetospheric features. A separate analysis on a two-month interval shows that the observed spectral characteristics are amplified by conditions of high-velocity solar wind. Acknowledgements. The authors are grateful to Prof. D. J. Southwood (Imperial College, London), J. C. Samson (University of Alberta, Edmonton), L. J. Lanzerotti (AT&T Bell Laboratories), A. Wolfe (New York City Technical College) and to Dr. M. Vellante (University of LÁquila) for helpful discussions. They also thank Dr. A. Meloni (Istituto Nazionale di Geofisica, Roma) who made available geomagnetic field observations from LÁquila Geomagnetic Observatory. This research activity at LÁquila is supported by MURST (40% and 60% contracts) and by GIFCO/CNR. Topical Editor K.-H. Glaßmeier thanks C. Waters and S. Fujita for their help in evaluating this paper.-> Francia->

  19. Observations of the intraseasonal oscillations over two Brazilian low latitude stations: A comparative study

    Science.gov (United States)

    Guharay, A.; Batista, P. P.; Clemesha, B. R.; Buriti, R. A.

    2014-12-01

    A comparative study of intraseasonal oscillations (ISO) in the period range 20-110 days is carried out in the mesosphere and lower thermosphere (MLT) zonal wind at two low latitude stations, Cariri (7.4°S, 36.5°W) and Cachoeira Paulista (22.7°S, 45°W) located far from the convective anomaly region. Considerable seasonal and interannual variability is observed. The ISO in the MLT and lower atmosphere are found to be well correlated during winter and spring indicating a coupling of the atmospheric regions through the ISO. On the other hand, relatively less correlation during summer and fall may suggest a dominance of the in situ excitation of the ISO in the MLT relative to the lower atmospheric contribution. The correlation between the MLT and lower atmosphere is found to be a little higher at Cachoeira Paulista than Cariri. The ISO in the MLT shows good correlation between the two stations, but correlation is insignificant in the case of lower atmosphere. The ISO is most prominent in the upper troposphere, upper stratosphere and MLT. The waves responsible for communicating the ISO signature from the troposphere to the middle atmosphere in the tropics are believed to refract through mid-latitudes in course of their propagation. An evident height variation of the high amplitude ISO in the upper troposphere is observed with a clear annual oscillation at Cariri. The observed behaviors of the ISO at the present sites are discussed in the light of plausible physical mechanisms.

  20. Gas phase abundances and conditions along the sight line to the low-halo, inner galaxy star HD 167756

    Science.gov (United States)

    Cardelli, Jason A.; Sembach, Kenneth R.; Savage, Blair D.

    1995-01-01

    We present high-resolution (3.5 km/s) Goddard High Resolution Spectrograph (GHRS) measurements of the Mg II, Si II, Cr II, Fe II, and Zn II lines toward HD 167756, a low-latitude halo star at a distance of 4 kpc in the direction l = 351.5 deg, b = -12.3 and at a Galactic altitude of z = -0.85 kpc. Supplemental Na I, Ca II, and H I data are also presented for comparison with the UV lines. Our analysis centers on converting the observed absoprtion-line data into measures of the apparent column density per unit velocity. N(sub a)(v), over the velocity range -25 less than or = v(sub lsr) less than 30 km/s for each species observed. We use these N(sub a)(v) profiles to construct logarithmic abundance ratios of Mg II, Si II, Cr II, Fe II, and Ca II relative to Zn II, normalized to solar abundances, as a function of velocity. Compared to Zn, these species show an underabundance relative to their solar values, with the largest underabundances occurring in the v(sub lsr) approximately equals 5 km/s component(s), for which we find logarithmic abundances A(sub Si/Zn) greater than -0.38, A(Mg/Zn) = -0.82, A(sub Cr/Zn) = -1.18, and A(sub Fe/Zn) greater than 1.40 dex. We show that ionization effects, abundance gradients, or intrinsic abundance variability cannot be significant sources for the underabundances observed. The most likely explanation is gas phase depletion of elements onto dust grains. Comparisons with the gas phase abundances along other diffuse, warm gas sight lines, like the halo sight line to HD 93521, support this interpretation as do the derived physical properties of the sight line.

  1. Low-latitude equinoctial spread-F occurrence at different longitude sectors under low solar activity

    Science.gov (United States)

    Pezzopane, M.; Zuccheretti, E.; Abadi, P.; de Abreu, A. J.; de Jesus, R.; Fagundes, P. R.; Supnithi, P.; Rungraengwajiake, S.; Nagatsuma, T.; Tsugawa, T.; Cabrera, M. A.; Ezquer, R. G.

    2013-02-01

    We present the results of a comparative study of spread-F signatures over five low-latitude sites: Chiangmai (CGM; 18.8° N, 98.9° E, mag. Lat. 8.8° N), Thailand; Tanjungsari (TNJ; 6.9° S, 107.6° E, mag. Lat. 16.9° S), Indonesia; Palmas (PAL; 10.2° S, 311.8° E, mag. Lat. 0.9° S) and São José Dos Campos (SJC; 23.2° S, 314.1° E, mag. Lat. 14.0° S), Brazil; and Tucumán (TUC; 26.9° S, 294.6° E, mag. Lat. 16.8° S), Argentina. The investigation was based on simultaneous ionograms recorded by an FMCW (frequency-modulated continuous-wave) at CGM, an IPS-71 (digital ionosonde from KEL aerospace) at TNJ, a CADI (Canadian Advanced Digital Ionosonde) at PAL and SJC, and an AIS-INGV (Advanced Ionospheric Sounder - Istituto Nazionale di Geofisica e Vulcanologia) at TUC, during the equinoctial periods March-April (R12 = 2.0 and R12 = 2.2) and September-October (R12 = 6.1 and R12 = 7.0) 2009, for very low solar activity. Spread-F signatures were categorized into two types: the range spread-F (RSF) and the frequency spread-F (FSF). The study confirms that the dynamics and the physical processes responsible for these phenomena are actually complicated. In fact, the features that arise from the investigation are different, depending on both the longitude sector and on the hemisphere. For instance, TUC, under the southern crest of the ionospheric equatorial ionization anomaly (EIA), shows a predominance of RSF signatures, while both SJC, under the southern crest of EIA but in a different longitude sector, and CGM, under the northern crest of EIA, show a predominance of FSF signatures. Moreover, the spread-F occurrence over the longitude sector that includes CGM and TNJ is significantly lower than the spread-F occurrence over the longitude sector of PAL, SJC, and TUC.

  2. Induction effects of geomagnetic disturbances in the geo-electric field variations at low latitudes

    Science.gov (United States)

    Doumbia, Vafi; Boka, Kouadio; Kouassi, Nguessan; Didier Franck Grodji, Oswald; Amory-Mazaudier, Christine; Menvielle, Michel

    2017-01-01

    In this study we examined the influences of geomagnetic activity on the Earth surface electric field variations at low latitudes. During the International Equatorial Electrojet Year (IEEY) various experiments were performed along 5° W in West Africa from 1992 to 1995. Among other instruments, 10 stations equipped with magnetometers and telluric electric field lines operated along a meridian chain across the geomagnetic dip equator from November 1992 to December 1994. In the present work, the induced effects of space-weather-related geomagnetic disturbances in the equatorial electrojet (EEJ) influence area in West Africa were examined. For that purpose, variations in the north-south (Ex) and east-west (Ey) components of telluric electric field were analyzed, along with that of the three components (H, D and Z) of the geomagnetic field during the geomagnetic storm of 17 February 1993 and the solar flare observed on 4 April 1993. The most important induction effects during these events are associated with brisk impulses like storm sudden commencement (ssc) and solar flare effect (sfe) in the geomagnetic field variations. For the moderate geomagnetic storm that occurred on 17 February 1993, with a minimum Dst index of -110 nT, the geo-electric field responses to the impulse around 11:00 LT at LAM are Ex = 520 mV km-1 and Ey = 400 mV km-1. The geo-electric field responses to the sfe that occurred around 14:30 LT on 4 April 1993 are clearly observed at different stations as well. At LAM the crest-to-crest amplitude of the geo-electric field components associated with the sfe are Ex = 550 mV km-1 and Ey = 340 mV km-1. Note that the sfe impact on the geo-electric field variations decreases with the increasing distance of the stations from the subsolar point, which is located at about 5.13° N on 4 April. This trend does not reflect the sfe increasing amplitude near the dip equator due the high Cowling conductivity in the EEJ belt.

  3. Wp index: A new substorm index derived from high-resolution geomagnetic field data at low latitude

    DEFF Research Database (Denmark)

    Nose, M.; Iyemori, T.; Wang, L.

    2012-01-01

    Geomagnetic field data with high time resolution (typically 1 s) have recently become more commonly acquired by ground stations. Such high time resolution data enable identifying Pi2 pulsations which have periods of 40-150 s and irregular (damped) waveforms. It is well-known that pulsations...... of this type are clearly observed at mid-and low-latitude ground stations on the nightside at substorm onset. Therefore, with 1-s data from multiple stations distributed in longitude around the Earth's circumference, substorm onset can be regularly monitored. In the present study we propose a new substorm...... index, the Wp index (Wave and planetary), which reflects Pi2 wave power at low-latitude, using geomagnetic field data from 11 ground stations. We compare the Wp index with the AE and ASY indices as well as the electron flux and magnetic field data at geosynchronous altitudes for 11 March 2010. We find...

  4. LSWS linked with the low-latitude Es and its implications for the growth of the R-T instability

    Science.gov (United States)

    Joshi, L. M.

    2016-07-01

    A comprehensive investigation of spread F irregularities over the Indian sector has been carried out using VHF radar and ionosonde observations. Two different categories of spread F observations, one where the onset of the range spread F (RSF) was concurrent with the peak h'F (category 1) and another where the RSF onset happened ~90 min after the peak h'F time (category 2), are presented. RSF in category 2 was preceded by the presence of oblique echoes in ionograms, indicating the irregularity genesis westward of Sriharikota. The average peak h'F in category 1 was ~30 km higher than that in category 2 indicating the presence of standing large-scale wave structure (LSWS). Occurrence of the blanketing Es during 19:30 to 20:30 Indian Standard Time in category 1 (category 2) was 0% (>50%). Model computation is also carried out to further substantiate the observational results. Model computation indicates that zonal variation of low-latitude Es can generate zonal modulation in the F layer height rise. It is found that the modulation of the F layer height, linked with the low-latitude Es, assists the equatorial spread F onset by modifying both the growth rate of the collisional Rayleigh-Taylor (R-T) instability and also its efficiency. A predominant presence of low-latitude Es has been observed, but the increase in the F layer height and the R-T instability growth in the evening hours will maximize with complete absence of low-latitude Es. A new mechanism for the generation of LSWS and its implications on R-T instability is discussed.

  5. Investigation of low-latitude ionospheric irregularities and their relationship to equatorial plasma bubbles using Sanya VHF radar

    Science.gov (United States)

    Ning, B.; Li, G.; Hu, L.

    2011-12-01

    A VHF radar has been set up at Sanya (18.34° N, 109.62° E, geomagnetic latitude 7.04°N), China in 2009. On the basis of the E, valley and F region irregularity observations detected by the Sanya VHF radar during equinoctial months, we focus on the simultaneous observations of E region irregularities disruption and valley region irregularities generation during the presence of post-sunset F region bubble structures. We stress that both the low latitude the E region irregularities (ERI) disruption and valley region irregularities (VRI) generation are associated with the development of post-sunset equatorial plasma bubble (EPB) structures. It is suggested that the electric field coupling from the unstable equatorial F region to low-latitude E and valley region could trigger and inhibit the occurrence of irregularities, depending on the polarity of the polarization electric field associated with the bifurcation of equatorial plasma bubbles. The mapping of upward/eastward and downward/eastward electric field associated with the west-tilted and east-tilted bubble structures, may be responsible for the disruption of E region irregularities, and the generation of valley region irregularities, respectively. However, more observations from multi instruments will be required to confirm such a scenario that the multi bifurcated EPBs play crucial roles for the simultaneous occurrence of low latitude ERI disruption and VRI generation.

  6. Effects of disturbed electric fields in the low-latitude and equatorial ionosphere during the 2015 St. Patrick's Day storm

    Science.gov (United States)

    Kuai, Jiawei; Liu, Libo; Liu, Jing; Sripathi, S.; Zhao, Biqiang; Chen, Yiding; Le, Huijun; Hu, Lianhuan

    2016-09-01

    The 2015 St. Patrick's Day geomagnetic storm with SYM-H value of -233 nT is an extreme space weather event in the current 24th solar cycle. In this work, we investigated the main mechanisms of the profound ionospheric disturbances over equatorial and low latitudes in the Asian-Australian sector and the American sector during this super storm event. The results reveal that the disturbed electric fields, which comprise penetration electric fields (PEFs) and disturbance dynamo electric fields (DDEFs), play a decisive role in the ionospheric storm effects in low latitude and equatorial regions. PEFs occur on 17 March in both the American sector and the Asian-Australian sector. The effects of DDEFs are also remarkable in the two longitudinal sectors. Both the DDEFs and PEFs show the notable local time dependence, which causes the sector differences in the characteristics of the disturbed electric fields. This differences would further lead to the sector differences in the low-latitude ionospheric response during this storm. The negative storm effects caused by the long-duration DDEFs are intense over the Asian-Australian sector, while the repeated elevations of hmF2 and the equatorial ionization anomaly intensifications caused by the multiple strong PEFs are more distinctive over the American sector. Especially, the storm time F3 layer features are caught on 17 March in the American equatorial region, proving the effects of the multiple strong eastward PEFs.

  7. "Alfa" i "Võmpel" bez maski / Andrei Sharov

    Index Scriptorium Estoniae

    Sharov, Andrei

    2004-01-01

    Venemaa FSB keskuse, mille koosseisu kuuluvad ka eriüksused Alfa ja Võmpel, töötajad osalevad terroristide neutraliseerimise ja pantvangide vabastamise erioperatsioonides. Intervjuu keskuse staabi uue juhiga

  8. "Alfa" i "Võmpel" bez maski / Andrei Sharov

    Index Scriptorium Estoniae

    Sharov, Andrei

    2004-01-01

    Venemaa FSB keskuse, mille koosseisu kuuluvad ka eriüksused Alfa ja Võmpel, töötajad osalevad terroristide neutraliseerimise ja pantvangide vabastamise erioperatsioonides. Intervjuu keskuse staabi uue juhiga

  9. ALFA detector upgrade before LHC Run 2

    CERN Document Server

    Vorobel, Vit; The ATLAS collaboration

    2016-01-01

    The operation experience with ATLAS ALFA detectors in the LHC environment during the Run1 period has shown significant beam-induced heating. Subsequent comprehensive studies revealed that heating effects could be disastrous in the case of the larger beam intensities foreseen for higher luminosities in the LHC Run2. During the first LHC long shutdown (LS1) all ALFA detectors have been removed from the LHC tunnel and their covers - Roman Pots - underwent a geometry upgrade to minimize the impedance losses. It will be shown that this modification together with a system improving the internal heat transfer and an air cooling system, significantly shifted the temperatures of ALFA detectors away from the critical limits throughout the LHC Run2. Also ALFA trigger system was considerably upgraded to keep measured data safely inside the Run2 ATLAS latency budget and to minimize dead time. The needed hardware changes of the trigger system will be presented in the second part of the talk.

  10. ALFA detector before LHC Run 2

    CERN Document Server

    Vorobel, Vit; The ATLAS collaboration

    2016-01-01

    The operation experience with ATLAS ALFA detectors in the LHC environment during the Run1 period has shown significant beam-induced heating. Subsequent comprehensive studies revealed that heating effects could be disastrous in the case of the larger beam intensities foreseen for higher luminosities in the LHC Run2. During the first LHC long shutdown (LS1) all ALFA detectors have been removed from the LHC tunnel and their covers - Roman Pots - underwent a geometry upgrade to minimize the impedance losses. It will be shown that this modification together with a system improving the internal heat transfer and an air cooling system, significantly shifted the temperatures of ALFA detectors away from the critical limits throughout the LHC Run2. Also ALFA trigger system was considerably upgraded to keep measured data safely inside the Run2 ATLAS latency budget and to minimize dead time. The needed hardware changes of the trigger system are also described

  11. Large enhancements in low latitude total electron content during 15 May 2005 geomagnetic storm in Indian zone

    Directory of Open Access Journals (Sweden)

    N. Dashora

    2009-05-01

    Full Text Available Results pertaining to the response of the equatorial and low latitude ionosphere to a major geomagnetic storm that occurred on 15 May 2005 are presented. These results are also the first from the Indian zone in terms of (i GPS derived total electron content (TEC variations following the storm (ii Local low latitude electrodynamics response to penetration of high latitude convection electric field (iii effect of storm induced traveling atmospheric disturbances (TAD's on GPS-TEC in equatorial ionization anomaly (EIA zone.

    Data set comprising of ionospheric TEC obtained from GPS measurements, ionograms from an EIA zone station, New Delhi (Geog. Lat. 28.42° N, Geog. Long. 77.21° E, ground based magnetometers in equatorial and low latitude stations and solar wind data obtained from Advanced Composition Explorer (ACE has been used in the present study. GPS receivers located at Udaipur (Geog. Lat. 24.73° N, Geog. Long. 73.73° E and Hyderabad (Geog. Lat. 17.33° N, Geog. Long. 78.47° E have been used for wider spatial coverage in the Indian zone. Storm induced features in vertical TEC (VTEC have been obtained comparing them with the mean VTEC of quiet days. Variations in solar wind parameters, as obtained from ACE and in the SYM-H index, indicate that the storm commenced on 15 May 2005 at 02:39 UT. The main phase of the storm commenced at 06:00 UT on 15 May with a sudden southward turning of the Z-component of interplanetary magnetic field (IMF-Bz and subsequent decrease in SYM-H index. The dawn-to-dusk convection electric field of high latitude origin penetrated to low and equatorial latitudes simultaneously as corroborated by the magnetometer data from the Indian zone. Subsequent northward turning of the IMF-Bz, and the penetration of the dusk-to-dawn electric field over the dip equator is also discernible. Response of the low latitude ionosphere to this storm may be characterized in terms of (i

  12. Receiver DCB estimation and GPS vTEC study at a low latitude station in the South Pacific

    Science.gov (United States)

    Prasad, Ramendra; Kumar, Sushil; Jayachandran, P. T.

    2016-11-01

    The statistical estimation of receiver differential code bias (DCB) of the GSV4004B receiver at a low latitude station, Suva (lat. 18.15°S, long. 178.45°E, Geomag. Lat. 21.07°S), Fiji, and the subsequent behaviour of vTEC, are presented. By means of least squares linear regression fitting technique, the receiver DCB was determined using the GPS vTEC data recorded during the year 2010, CODE TEC and IRI-2012 model for 2010. To substantiate the results, minimization of the standard deviation (SD) method was also used for GPS vTEC data. The overall monthly DCB was estimated to be in the range of 62.6 TECU. The vTEC after removing the resultant monthly DCB was consistent with other low latitude observations. The GPS vTEC 2010 data after eliminating the resultant DCB were lower in comparison to Faraday rotation vTEC measurements at Suva during 1984 primarily due to higher solar activity during 1984 as compared to 2010. Seasonally, vTEC was maximum during summer and minimum during winter. The winter showed least vTEC variability whereas equinox showed the largest daytime variability. The geomagnetic disturbances effect showed that both vTEC and its variability were higher on magnetically disturbed days as compared to quiet days with maximum variability in the daytime. Two geomagnetic storms of moderate strengths with main phases in the local daytime showed long duration (∼52 h) increase in vTEC by 33-67% which can be accounted by changes in E×B drifts due to prompt penetration of storm-time auroral electric field in the daytime and disturbance dynamo electric field in the nighttime to low latitudes.

  13. Case study on total electron content enhancements at low latitudes during low geomagnetic activities before the storms

    Directory of Open Access Journals (Sweden)

    Libo Liu

    2008-05-01

    Full Text Available Sometimes the ionospheric total electron content (TEC is significantly enhanced during low geomagnetic activities before storms. In this article, we investigate the characteristics of those interesting TEC enhancements using regional and global TEC data. We analyzed the low-latitude TEC enhancement events that occurred around longitude 120° E on 10 February 2004, 21 January 2004, and 4 March 2001, respectively. The TEC data are derived from regional Global Positioning System (GPS observations in the Asia/Australia sector as well as global ionospheric maps (GIMs produced by Jet Propulsion Laboratory (JPL. Strong enhancements under low geomagnetic activity before the storms are simultaneously presented at low latitudes in the Asia/Australia sector in regional TEC and JPL GIMs. These TEC enhancements are shown to be regional events with longitudinal and latitudinal extent. The regions of TEC enhancements during these events are confined at narrow longitude ranges around longitude 120° E. The latitudinal belts of maxima of enhancements locate around the northern and southern equatorial ionization anomaly (EIA crests, which are consistent with those low-latitude events presented by Liu et al. (2008. During the 4 March 2001 event, the total plasma density Ni observed by the Defense Meteorological Satellite Program (DMSP spacecraft F13 at 840 km altitude are of considerably higher values on 4 March than on the previous day in the TEC enhanced regions. Some TEC enhancement events are possibly due to contributions from auroral/magnetospheric origins; while there are also quasi-periodic enhancement events not related to geomagnetic activity and associated probably with planetary wave type oscillations (e.g. the 6 January 1998 event. Further investigation is warrented to identify/separate contributions from possible sources.

  14. On the dynamics of low latitude, wide and shallow coastal system: numerical simulations of the Upper Gulf of Thailand

    Science.gov (United States)

    Saramul, Suriyan; Ezer, Tal

    2014-04-01

    A high-resolution (˜1 km horizontal grid and 21 vertical layers) numerical model based on the Princeton Ocean Model (POM) has been used to study the 3D dynamics of the Upper Gulf of Thailand (UGOT). While influenced by tides and rivers like other estuarine systems, the UGOT is unique because it is wide (˜100 km × 100 km), it is shallow (average depth of only ˜15 m), it is located in low latitudes (˜12.5°N-13.5°N), and it is influenced by the seasonal monsoon. Sensitivity studies were thus conducted to evaluate the impact that surface heat fluxes, monsoonal winds, river runoffs, and the low latitude may have on the dynamics; the latter has been evaluated by modifying the Coriolis parameter and comparing simulations representing low and mid latitudes. The circulation in the UGOT changes seasonally from counter-clockwise during the northeast monsoon (dry season) to clockwise during the southwest monsoon (wet season). River discharges generate coastal jets, whereas river plumes tend to be more symmetric near the river mouth and remain closer to the coast in low latitudes, compared with mid-latitude simulations. River plumes are also dispersed along the coast in different directions during different stages of the monsoonal winds. The model results are compared favorably with a simple wind-driven analytical estuarine model. Comparisons between an El Niño year (1998) and a La Niña year (2000) suggest that water temperatures, warmer by as much as 2 °C in 1998 relative to 2000, are largely driven by decrease cloudiness during the El Niño year. The developed model of the UGOT could be used in the future to address various environmental problems affecting the region.

  15. Nighttime D region electron density measurements from ELF-VLF tweek radio atmospherics recorded at low latitudes

    OpenAIRE

    İnan, Umran Savaş; Maurya, Ajeet K.; Veenadhari, B. ; Singh, Rajesh ; Kumar, Sushil ; Cohen, M. B. ; Selvakumaran, R. ; Gokani, Sneha ; Pant, P.; Singh, A. K.

    2012-01-01

    Dispersive atmospherics (tweeks) observed during 2010 simultaneously at two low-latitude stations, Allahabad (geomagnetic latitude, 16.05 N) and Nainital (geomagnetic latitude, 20.48 N), have been used to estimate the nighttime D region electron density at the ionospheric reflection height under the local nighttime propagation (21:00–02:00 LT or 15:30–20:30 UT). The analysis of simultaneously recorded tweeks at both the stations on five international quiet days during one month...

  16. Climatology of low latitude ionosphere under effect of varying solar flux during solar cycle 23 and 24

    Science.gov (United States)

    Dashora, Nirvikar; Suresh, Sunanda

    2016-07-01

    The characteristics of quiet time equatorial and low latitude total electron content (TEC) over the Indian sector using GIM data (1998-2014) is obtained. For the first time the analysis is carried filtering out the solar flare and storm effects and time series of quiet time VTEC data from three locations namely dip equator and two low latitude conjugate locations in Indian sector are obtained. It is well known that a complex interplay among drivers of equatorial electrodynamics like Solar flux, dynamo electric field and meridional winds determine the daytime ionization and distribution in equatorial ionization anomaly zone. In this study, we have critically examined the role of varying solar flux and response of low latitude ionosphere with new and standardized definitions. The results are examined and interpreted in the context of large number of previous studies. The newly found features from this study are as follows. Marked difference in nature of equinoctial asymmetry is noted between solar cycle 23 and 24. Long absence of winter anomaly both during low and high solar activity (HSA) in LL (low latitude) regions is found. Climatology of the diurnal cycle is provided in four categories using new criteria for demarcation of solar activity levels. Highest correlation (~77%) between GIM ionospheric electron content (IEC) and PI (solar EUV proxy index) is noted over equator in contrast to previous studies. The minimum positive contribution of PI in variation of IEC requires minimum of 2 years of data and if more than 7-8 years of data is used, it saturates. RMS (root mean square) width of PI can be used to define the HSA. Strong QBO (quasi biennial oscillations) in IEC is noted in tune with the one in PI over both the LL location but QBO remains surprisingly subdued over equator. The semi-annual oscillations in GIM-IEC are found to be stronger at all locations during high solar activity and weaker between 2005 and 2011, whereas, the annual oscillations are found to

  17. Terrestrial responses of low-latitude Asia to the Eocene–Oligocene climate transition revealed by integrated chronostratigraphy

    Directory of Open Access Journals (Sweden)

    Y.-X. Li

    2015-07-01

    Full Text Available The Paleogene sedimentary records from southern China hold important clues to the impacts of the Cenozoic climate changes on low-latitudes. However, although there are extensive Paleogene terrestrial archives and some contain abundant fossils in this region, few are accurately dated and have a temporal resolution adequate to decipher climate changes. Here we present a detailed stratigraphic and paleomagnetic study of a fossiliferous late Paleogene succession in the Maoming Basin, Guangdong Province. The succession consists of oil shale of the Youganwo Formation (Fm in the lower part and massive pebbly coarse sandstones of the overlying Huangniuling Fm in the upper part. The conformable transition from oil shale to sandstones represents a major depositional environmental change from a lacustrine to a deltaic environment. The substantially refined chronostratigraphic framework is established based on the litho-, bio-, cyclo-, and magnetostratiphic data that place the environmental transition at 33.88 Ma, coinciding with the Eocene–Oligocene climate transition (EOT at ~ 33.7 to ~ 33.9 Ma. We suggest that the transition from a lacustrine to deltaic environment in Maoming Basin represents terrestrial responses to the EOT and indicates a significant reduction in hydrodynamics in low-latitude regions during the global cooling at EOT.

  18. Comparative study on the ionospheric response to minor and major sudden stratospheric events in the Brazilian equatorial and low latitudes

    Science.gov (United States)

    Fagundes, Paulo Roberto; Kavutarapu, Venkatesh; Gil Pillat, Valdir; Vieira, Francisco

    2016-07-01

    The Total electron Content (TEC), derivate from GPS, becomes one of the most powerful techniques to study the space-time ionospheric (F-region) electrodynamics, during the quiet and disturbed periods. The number of GPS stations in Brazil increased significantly during the last few years; currently more than 100 GPS stations are in operation over the Brazilian region. The GPS-TEC values are derived using the differential delay technique from the dual frequency measurements at L1 and L2 frequencies over the considered locations at equatorial and low latitudes. The present study investigates the ionospheric total electron content (GPS-TEC) response in the Southern Hemisphere equatorial and low latitudes, due to major and minor sudden stratospheric warming (SSW) events, which took place during 2009 and 2012. During both the SSW events, the TEC values are depleted to the order of 20-30% all over the Brazil from equator to beyond Equatorial Ionization Anomaly (EIA) regions. In addition, the EIA were suppressed during the SSW events for several days. However, the TEC depletion and EIA suppression lasted for a longer period during SSW-2012 when compared with the SSW-2009; despite the SSW-2012 is considerd as a minor event.

  19. Simultaneous in-situ observations of the signatures of dayside reconnection at the high- and low-latitude magnetopause

    Directory of Open Access Journals (Sweden)

    J. A. Wild

    2005-02-01

    Full Text Available We present magnetic field and particle data recorded by the Cluster and Geotail satellites in the vicinity of the high- and low-latitude dayside magnetopause, respectively, on 17 February 2003. A favourable conjunction of these spacecraft culminated in the observation of a series of flux transfer events (FTEs, characterised by bipolar perturbations in the component of the magnetic field normal to the magnetopause, an enhancement in the overall magnetic field strength, and field tilting effects in the plane of the magnetopause whilst the satellites were located on the magnetosheath side of the boundary. Whilst a subset of the FTE signatures observed could be identified as being either normal or reverse polarity, the rapid succession of events observed made it difficult to classify some of the signatures unambiguously. Nevertheless, by considering the source region and motion of flux tubes opened by magnetic reconnection at low latitudes (i.e. between Cluster and Geotail, we demonstrate that the observations are consistent with the motion of northward (southward and tailward moving flux tubes anchored in the Northern (Southern Hemisphere passing in close proximity to the Cluster (Geotail satellites. We are able to demonstrate that a multi-spacecraft approach, coupled with a realistic model of flux tube motion in the magnetosheath, enables us to infer the approximate position of the reconnection site, which in this case was located at near-equatorial latitudes.

  20. Comparison study on ionospheric spread-F between high and low latitude regions during the storm time

    Science.gov (United States)

    Shi, Jiankui; Tao, Wei; Wang, Guojun; Wang, Xiao; Zherebtsov, Gelii; Pirog, Olga; Romanova, Elena

    We use DPS-4 digisonde measurement data from ionospheric station Hainan (19.4N, 109.0E), China, and Yakutsk (62N, 129E) and Zhigansk (66N, 123E), Russia to study ionospheric Spread-F (SF) properties during the magnetic storm time. The results show that: (1) The SF can take place in any phase (suddenly commencement, main phase and recovery phase). (2) The SF always take place from about 2000LT to around midnight, and the more the latitude is, the earlier the SF takes place. (3) Yakutsk station has a higher occurrence of SF than that both in the higher latitude station (Zhigansk) and lower latitude station (Hainan). (4) The frequency SF, range SF and mixed SF can be observed at any latitude station. The strong range SF can only be observed at Hainan station (low latitude station) and it confirms that the strong range SF concerns the equatorial plasma bubble. Our results indicate that ionospheric disturbance which causes the SF, during the storm time, is original from the higher latitude region and propagate to the lower region. Sometimes it could excite out SF at low latitude region and sometimes it could not.

  1. Theoretical simulation of O+ and H+ densities in the Indian low latitude F-region and comparison with observations

    Directory of Open Access Journals (Sweden)

    S. B. Singh

    Full Text Available The O+ and H+ ion density distributions in the Indian low latitude F-region, within ± 15° magnetic latitudes, are simulated using a time dependent model developed on the basis of solution of the plasma continuity equation. The simulated ion densities for solar minimum June and December solstices are then compared with ionosonde observations from the period 1959–1979 and measurements made by the Indian SROSS C2 satellite during 1995–1996 at an altitude of ~ 500 km. The simulated O+ density has a minimum around pre-sunrise hours and a maximum during noontime. H+ density is higher at nighttime and lower during the day. The simulations reproduced the well-known equatorial ionization anomaly (EIA observed in electron density at the peak of the F2-region in the Indian low latitude sector during solar minimum. In situ measurement of O+ density by the SROSS C2, however, showed a single peak of ionization around the equator.Key words. Ionosphere (equatorial ionosphere; modeling and forecasting

  2. Distinct responses of the low-latitude ionosphere to CME and HSSWS: The role of the IMF Bz oscillation frequency

    Science.gov (United States)

    Rodríguez-Zuluaga, J.; Radicella, S. M.; Nava, B.; Amory-Mazaudier, C.; Mora-Páez, H.; Alazo-Cuartas, K.

    2016-11-01

    In this work an attempt to identify the role of the interplanetary magnetic field (IMF) in the response of the ionosphere to different solar phenomena is presented. For this purpose, the day-to-day variability of the equatorial ionospheric anomaly (EIA) and the main ionospheric disturbances are analyzed during one coronal mass ejection (CME) and two high-speed solar wind streams (HSSWSs). The EIA parameters considered are the zonal electric field and both the strength and position of its northern crest. The disturbances being the prompt penetration of magnetospheric electric field (PPMEF) and disturbance dynamo electric field (DDEF) are studied using the magnetic response of their equivalent current systems. In accordance, ground-based Global Navigation Satellite Systems receivers and magnetometers at geomagnetic low latitudes in the American sector are used. During both phenomena, patterns of PPMEF related to fluctuations of the IMF are observed. Diurnal and semidiurnal magnetic oscillations are found to be likely related to DDEF. Comparisons among the EIA parameters and the DDEF magnetic response exhibit poor relation during the CME in contrast to good relation during the HSSWSs. It is concluded that the response of the low-latitude ionosphere to solar phenomena is largely determined through the oscillation frequency of the IMF Bz by affecting the generation of the PPMEF and DDEF differently. This is seen as an effect of how the energy from the solar wind is transferred into the magnetosphere-ionosphere system.

  3. Analysis of strong ionospheric scintillation events measured by means of GPS signals at low latitudes during disturbed conditions

    Science.gov (United States)

    Forte, B.

    2012-08-01

    Drifting structures characterized by inhomogeneities in the spatial electron density distribution at ionospheric heights cause the scintillation of radio waves propagating through. The fractional electron density fluctuations and the corresponding scintillation levels may reach extreme values at low latitudes during high solar activity. Different levels of scintillation were observed on experimental data collected in the Asian sector at low latitudes by means of a GPS dual frequency receiver under moderate solar activity (2005). The GPS receiver used in these campaigns was particularly modified in firmware in order to record power estimates on the C/A code as well as on the carriers L1 and L2. Strong scintillation activity was recorded in the post-sunset period (saturatingS4 and SI as high as 20 dB). Spectral modifications and broadening was observed during high levels of scintillation possibly indicating refractive scattering taking place instead of diffractive scattering. A possible interpretation of those events was attempted on the basis of the refractive scattering theory developed by Uscinski (1968) and Booker and MajidiAhi (1981).

  4. Two-dimensional ionospheric tomography over the low-latitude Indian region: An intercomparison of ART and MART algorithms

    Science.gov (United States)

    Das, Sukanta Kumar; Shukla, Ashish Kumar

    2011-04-01

    Single-frequency users of a satellite-based augmentation system (SBAS) rely on ionospheric models to mitigate the delay due to the ionosphere. The ionosphere is the major source of range and range rate errors for users of the Global Positioning System (GPS) who require high-accuracy positioning. The purpose of the present study is to develop a tomography model to reconstruct the total electron content (TEC) over the low-latitude Indian region which lies in the equatorial ionospheric anomaly belt. In the present study, the TEC data collected from the six TEC collection stations along a longitudinal belt of around 77 degrees are used. The main objective of the study is to find out optimum pixel size which supports a better reconstruction of the electron density and hence the TEC over the low-latitude Indian region. Performance of two reconstruction algorithms Algebraic Reconstruction Technique (ART) and Multiplicative Algebraic Reconstruction Technique (MART) is analyzed for different pixel sizes varying from 1 to 6 degrees in latitude. It is found from the analysis that the optimum pixel size is 5° × 50 km over the Indian region using both ART and MART algorithms.

  5. The response of local power grid at low-latitude to geomagnetic storm: An application of the Hilbert Huang transform

    Science.gov (United States)

    Liu, Jin; Wang, Chuan-Bing; Liu, Lu; Sun, Wei-Huai

    2016-04-01

    The Hilbert-Huang transform (HHT) is an adaptive data analysis method that can accommodate the variety of data generated by nonlinear and nonstationary processes in nature. In this paper, we focus on the small geomagnetically induced current (GIC) at the local substations in low-latitude power grid of China, responding to a moderate storm on 14-18 July 2012. The HHT is applied to analyze the neutral point currents (NPCs) of transformers measured at different substations, and the GIC indices converted from local geomagnetic field measurements. The original data are decomposed into intrinsic mode functions (IMFs) using the ensemble empirical mode decomposition. After removal of the quasi-diurnal components related with the solar quiet variation, the IMFs representing storm disturbances are transformed into Hilbert energy spectra. The results show that some transformers have more or less responses to the moderate storm in the form of Hilbert energy spectra with the frequency around 2-3 mHz. A comparison on the amplitude changes of the spectra total energy of NPCs' perturbation during storm time intervals at different sites suggests that a shell type of three-phase single transformer group seems to be more vulnerable in the storm. Although the low-latitude power grids usually show very small GIC, these can be used to investigate the potential risk of space weather to the system.

  6. Low latitude ionospheric effects near longitude 120°E during the great geomagnetic storm of July 2000

    Institute of Scientific and Technical Information of China (English)

    LIU; Libo(刘立波); WAN; Weixing(万卫星); NING; Baiqi(宁百齐); YUAN; Hong(袁洪); Liu; J.Y.

    2002-01-01

    A great geomagnetic storm occurred on July 15/16, 2000 with a minimum value of about -300 nT in Dst index. Collecting digisonde data from ionospheric stations at Chungli, Wuhan, Kokubunji and Anyang, the ionospheric responses at the low latitudes near longitude 120(E during this storm are analyzed in this paper. There was a strong negative phase storm at low latitudes on July 16. The G-condition in the ionograms was clearly seen on the early first day after the commencement of geomagnetic storm. Those were considered to be caused by the storm-induced increase in the concentration ratios of neutral molecular O2 or N2 to atom O. On July 17 and some days thereafter, a positive phase storm appeared. In addition, anomalous equatorial ionization anomaly (EIA) inhibitions and developments were observed on July 16 and 17. There were also prominent nighttime enhancements in foF2 during these days, and the diurnal variation of foF2 was less clear than before.

  7. Studies of ionospheric variations during geomagnetic activities at the low-latitude station, Ile-Ife, Nigeria

    Science.gov (United States)

    Emmanuel, Ariyibi

    The dual frequency SCINDA NovAtel GSV 4004B GPS receiver installed at the Ile-Ife (low-latitude station) has been in operation since December 2009. Data records for the year 2010 were processed to obtain Total Electron Content (TEC) and S 4 index. These were interpreted to analyze the ionospheric condition during low geomagnetic activity period (when Dst is from -40 to 0 nT) and during geomagnetic storm events (with Dst about -100 nT). Seasonal variations of the TEC and S 4 index were also investigated. The occurrence of scintillations is closely linked to the peak value of TEC during the daytime; this is very evident during the equinox months when TEC ≥ 30 TECu. When the maximum TEC value is below 30 TECu, as shown by most of the days in the summer months, the scintillation phenomenon does not occur. During geomagnetic storms, the daytime segment of the TEC plot experiences fluctuations (even bifurcations) in values with the peak TEC value of about 40 TECu. From the interpreted data, the occurrence of geomagnetic storm does not necessarily suggest an increase in the level of scintillations at a low-latitude region. Also, there is a remarkable difference between the IRI 2007 model and the observed TEC values, as the daytime TEC peak differs in magnitude and time of occurrence from the observed TEC.

  8. Millennial-scale interhemispheric asymmetry of low-latitude precipitation: speleothem evidences and possible high-latitude forcing

    Science.gov (United States)

    Wang, X.; Auler, A.; Edwards, R.; Cheng, H.; Ito, E.

    2006-12-01

    A high resolution oxygen isotopic record of cave calcite, spanning the last 90,000 years, was obtained from Caverna Botuverá, southern Brazil. The record broadly follows local insolation changes and shows significant millennial-scale variation with amplitudes as large as 3 per mil. Tests for equilibrium conditions show that oxygen isotopic variations are a direct reflection of changes in rainwater values and temperatures at this low- latitude location. Established with independent absolute-dated uranium series chronologies, our record anti- correlates remarkably with the contemporaneous oxygen isotopic records of cave calcite from eastern China (anti-phase precipitation changes), but positively correlates with the record of speleothem growth periods from northeastern Brazil (in-phase precipitation changes) on millennial time scales. These observations suggest that a rainfall seesaw may have existed between the southern and northern low latitudes on millennial time scales in the past. This interhemipheric anti-phasing of rainfall is probably caused by feedbacks between North Atlantic thermohaline circulation and the intertropical convergence. The interplays affect not only North Atlantic climate but also result in the displacement of the mean position of the intertropical convergence zone and associated asymmetry of the Hadley cell. The Brazilian speleothem records further indicate that millennial-scale abrupt climate change is largely tied to meridional shifts rather than zonal shifts, and are therefore unlikely to have been triggered by tropical Walker circulation changes.

  9. ULF fluctuations of the geomagnetic field and ionospheric sounding measurements at low latitudes during the first CAWSES campaign

    Directory of Open Access Journals (Sweden)

    U. Villante

    2006-07-01

    Full Text Available We present an analysis of ULF geomagnetic field fluctuations at low latitudes during the first CAWSES campaign (29 March-3 April 2004. During the whole campaign, mainly in the prenoon sector, a moderate Pc3-4 pulsation activity is observed, clearly related to interplanetary upstream waves. On 3 April, in correspondence to the Earth's arrival of a coronal mass ejection, two SIs are observed whose waveforms are indicative of a contribution of the high-latitude ionospheric currents to the low-latitude ground field. During the following geomagnetic storm, low frequency (Pc5 waves are observed at discrete frequencies. Their correspondence with the same frequencies detected in the radial components of the interplanetary magnetic field and solar wind speed suggests that Alfvénic solar wind fluctuations may act as direct drivers of magnetospheric fluctuations. A cross-phase analysis, using different pairs of stations, is also presented for identifying field line resonant frequencies and monitoring changes in plasmaspheric mass density. Lastly, an analysis of ionospheric vertical soundings, measured at the Rome ionosonde station (41.8° N, 12.5° E, and vertical TEC measurements deduced from GPS signals within an European network shows the relation between the ULF resonances in the inner magnetosphere and thermal plasma density variations during geomagnetically quiet conditions, in contrast to various storm phases at the end of the CAWSES campaign.

  10. Administration of follitropin alfa and lutropin alfa combined in a single injection: a feasibility assessment

    Directory of Open Access Journals (Sweden)

    Agostinetto Rita

    2009-05-01

    Full Text Available Abstract Background Gonadotrophins are routinely administered in assisted reproductive technology (ART treatment protocols. Recombinant human follicle-stimulating hormone (r-hFSH; follitropin alfa and recombinant human luteinizing hormone (r-hLH; lutropin alfa can be administered individually or in a fixed combination. The ability to vary the FSH to LH dose ratio in a single injection without compromising the bioactivity of either gonadotrophin or generating losses of active principle is important for physicians and patients alike. Methods This study investigated whether follitropin alfa (GONAL-f (R, as lyophilized powder for reconstitution or solution from the GONAL-f (R (filled-by-mass [FbM] Prefilled Pen, could be used to reconstitute Pergoveris TM (follitropin alfa/lutropin alfa 150 IU/75 IU lyophilized powder. In Ratio Groups 1 and 2, the r-hFSH:r-hLH ratio was 3:1; in Ratio Groups 3 and 4, the ratios of r-hFSH:r-hLH were 5:1 and 8:1, respectively. The protein content and bioactivity of each mixed solution were evaluated. The r-hFSH and r-hLH content was determined using reverse-phase high performance liquid chromatography. The biological activity of r-hFSH and r-hLH was assessed using the Steelman-Pohley and Van Hell in vivo bioassays in rats, respectively. Results Follitropin alfa/lutropin alfa 150 IU/75 IU lyophilized powder could be successfully mixed with follitropin alfa 75 IU FbM solution that was either reconstituted from lyophilized powder or injected directly from the prefilled pen to create solutions with ratios of r-hFSH and r-hLH from 3:1 to 8:1. The measured content of r-hFSH and r-hLH corresponded favourably with the target protein content in Ratio Groups 1–4. The in vivo target and measured bioactivity of r-hFSH and r-hLH were also closely matched in all Ratio Groups. Conclusion Follitropin alfa lyophilized powder or solution can be accurately mixed with follitropin alfa/lutropin alfa 150 IU/75 IU lyophilized powder to

  11. Implementation of Trigger Tiles for ALFA Simulation

    CERN Document Server

    Rehaag, Thomas Joseph

    2017-01-01

    The Absolute Luminosity For ATLAS (ALFA) experiment was designed to accurately measure the luminosity of the intersecting proton beams at the ATLAS interaction point [1]. However, the ALFA experiment has shifted its primary purpose from luminosity measurement to elastic and inelastic proton collisions. This change was the result of difficulty in fitting parameters in the region governed by Coulomb scattering. The operational principle for luminosity measurement with ALFA relied on detecting elastic proton collisions, so the detector is suited to its role in proton collision measurements. The ALFA detector consists of several sensitive components, including the main detector (MD), overlap detectors (ODs) and trigger tiles. A diagram of the ALFA detector is shown in Figure 1. The main detector is composed of layers of 0.5 × 0.5 mm2 cross section scintillating fibres with an active area of 0.48 × 0.48 mm2, which are directed diagonally across the detector with 64 fibres in each layer. The 20 total layers ar...

  12. Interferon-alfa treatment of facial infantile haemangiomas

    DEFF Research Database (Denmark)

    Fledelius, Hans C.; Illum, N.; Jensen, H.

    2001-01-01

    ophthalmology, haemangiomas of the face, infancy, Interferon alfa, eye at risk, amblyopia, induced refractive change, ultrasound imaging......ophthalmology, haemangiomas of the face, infancy, Interferon alfa, eye at risk, amblyopia, induced refractive change, ultrasound imaging...

  13. Interferon alfa with or without ribavirin for chronic hepatitis C

    DEFF Research Database (Denmark)

    Kjaergard, L L; Krogsgaard, K; Gluud, C

    2001-01-01

    To assess the efficacy and safety of interferon alfa with or without ribavirin for treatment of chronic hepatitis C.......To assess the efficacy and safety of interferon alfa with or without ribavirin for treatment of chronic hepatitis C....

  14. New historical records and relationships among 14C production rates, abundance and color of low latitude auroras and sunspot abundance

    Science.gov (United States)

    Abbott, Dallas; Juhl, Robert

    2016-12-01

    Incursions of high-energy particles from space, specifically solar energetic particles and galactic cosmic rays, have significant effects on the Earth, including disruption of the Earth's magnetic field, generation of electric fields strong enough to damage electronic devices as well as the production of auroras at low-latitudes, within 45° of the magnetic equator. We examine the relationships among 14C production, auroral abundance, auroral color and sunspot abundance using existing data supplemented by a new dataset. The new dataset, based on Chinese and Korean records from A.D. 1100-1700, includes 46 new or revised records of sunspots and 279 records of low-latitude auroras. Low-latitude auroras are predominantly red (66%, 835 events) with lesser proportions of white (20%, 253 events) and black auroras (6%, 67 events). All other auroral colors (green, yellow, multicolored, blue and purple) aggregate to a total of 100 events (8%). Overall, white auroras are more frequent during times of higher 14C production. We use two empirical methods of evaluating the flux of high-energy particles: modeled peaks and lows in 14C production and peaks and lows in the 14C calibration curve. We find that comparison to modeled 14C production gives significant results. White auroras are significantly more abundant (98% probability) at times of high production of 14C. Red auroras are somewhat more abundant (88% probability) at times of low production of 14C. The abundances of black, multicolored, green, yellow, and blue auroras between times of low and high 14C production are not significantly different. Violet/purple auroras are significantly more abundant (98% probability) at times of low 14C production. The positive correlation of violet/purple auroras with times of low14C production rate and the lack of correlation of blue auroras with times of high14C production is surprising, for this portion of the visible spectrum contains strong emission lines and some lines with high

  15. Transmission of the electric fields to the low latitude ionosphere in the magnetosphere-ionosphere current circuit

    Science.gov (United States)

    Kikuchi, Takashi; Hashimoto, Kumiko K.

    2016-12-01

    The solar wind energy is transmitted to low latitude ionosphere in a current circuit from a dynamo in the magnetosphere to the equatorial ionosphere via the polar ionosphere. During the substorm growth phase and storm main phase, the dawn-to-dusk convection electric field is intensified by the southward interplanetary magnetic field (IMF), driving the ionospheric DP2 currents composed of two-cell Hall current vortices in high latitudes and Pedersen currents amplified at the dayside equator (EEJ). The EEJ-Region-1 field-aligned current (R1 FAC) circuit is completed via the Pedersen currents in midlatitude. On the other hand, the shielding electric field and the Region-2 FACs develop in the inner magnetosphere, tending to cancel the convection electric field at the mid-equatorial latitudes. The shielding often causes overshielding when the convection electric field reduces substantially and the EEJ is overcome by the counter electrojet (CEJ), leading to that even the quasi-periodic DP2 fluctuations are contributed by the overshielding as being composed of the EEJ and CEJ. The overshielding develop significantly during substorms and storms, leading to that the mid and low latitude ionosphere is under strong influence of the overshielding as well as the convection electric fields. The electric fields on the day- and night sides are in opposite direction to each other, but the electric fields in the evening are anomalously enhanced in the same direction as in the day. The evening anomaly is a unique feature of the electric potential distribution in the global ionosphere. DP2-type electric field and currents develop during the transient/short-term geomagnetic disturbances like the geomagnetic sudden commencements (SC), which appear simultaneously at high latitude and equator within the temporal resolution of 10 s. Using the SC, we can confirm that the electric potential and currents are transmitted near-instantaneously to low latitude ionosphere on both day- and night

  16. ALFA: an automated line fitting algorithm

    CERN Document Server

    Wesson, Roger

    2015-01-01

    I present the Automated Line Fitting Algorithm, ALFA, a new code which can fit emission line spectra of arbitrary wavelength coverage and resolution, fully automatically. In contrast to traditional emission line fitting methods which require the identification of spectral features suspected to be emission lines, ALFA instead uses a list of lines which are expected to be present to construct a synthetic spectrum. The parameters used to construct the synthetic spectrum are optimised by means of a genetic algorithm. Uncertainties are estimated using the noise structure of the residuals. An emission line spectrum containing several hundred lines can be fitted in a few seconds using a single processor of a typical contemporary desktop or laptop PC. I show that the results are in excellent agreement with those measured manually for a number of spectra. Where discrepancies exist, the manually measured fluxes are found to be less accurate than those returned by ALFA. Together with the code NEAT (Wesson et al. 2012), ...

  17. The storm-time ring current: a statistical analysis at two widely separated low-latitude stations

    Directory of Open Access Journals (Sweden)

    P. Francia

    2004-11-01

    Full Text Available We conducted a statistical analysis of the geomagnetic field variations during the storm main phase at two low-latitude stations, separated by several hours in magnetic local time, in order to investigate the asymmetry and longitudinal extent of the storm-time ring current. The results show evidence for an asymmetric current which typically extends from evening to noon and, during moderate solar wind electric field conditions, up to the early morning, confirming the important role of the magnetospheric convection in the ring current energization. We also analyzed a possible relationship between the local current intensity during the storm main phase and the substorm activity observed at different time delays τ with respect to the storm onset. The results show a significant anticorrelation for τ =-1h, indicating that if the substorm activity is high just before the storm, a weaker ring current develops.

  18. Ionospheric E–F valley observed by a sounding rocket at the low-latitude station Hainan

    Directory of Open Access Journals (Sweden)

    J. K. Shi

    2013-08-01

    Full Text Available According to the sounding rocket experiment conducted at Hainan ionospheric observatory (19.5° N, 109.1° E, a valley between the E layer and F layer in the ionospheric electron density profile is observed and presented. The sounding rocket was launched in the morning (06:15 LT on 7 May 2011, and the observed electron density profile outside the valley agrees with the simultaneous observation by the DPS-4 digisonde at the same station. The width of the observed valley was about 42 km, the depth almost 50%, and the altitude of the electron density minimum 123.5 km. This is the first observation of the E–F valley in the low-latitude region in the East Asian sector. The results are also compared with models, and the physical mechanism of the observed valley is discussed in this paper.

  19. Simulation of low latitude ionospheric response to 2015 St. Patrick's Day super geomagnetic storm over Indian longitude sector

    Science.gov (United States)

    Mohan Joshi, Lalit; Sripathi, Samireddipelle; Singh, Ram

    2016-07-01

    We present low latitude ionospheric response over Indian longitude to the recent super geomagnetic storm of 17 March 2015, using the SAMI2 model which incorporates ionosonde derived vertical drift impacted by prompt penetration eastward electric field occurring during the evening Prereversal Enhancement (PRE) in the vertical drift. The importance of this storm is that (a) Dst reaches as low as -228 nT and (b) prompt penetration of eastward electric field coincided with evening hours PRE. The daytime vertical EXB drifts in the SAMI2 model are, however, considered based on Scherliess-Fejer model. The simulations indicate a significant enhancement in F layer height and equatorial ionization anomaly (EIA) in the post sunset hours on 17 March 2015 vis-a-vis quiet day. The model simulations during recovery phase, considering disturbance dynamo vertical EXB drift along with equatorward disturbance wind, indicates suppression of the daytime EIA. SAMI2 simulations considering the disturbance wind during the recovery phase suggests that equatorward wind enhances the ionospheric density in the low latitude, however, its role in the formation of the EIA depends on the polarity of the zonal electric field. Comparison of model derived total electron content (TEC) with the TEC from ground GPS receivers indicate that model does reproduce enhancement of the EIA during the main phase and suppression of the EIA during the recovery phase of the super storm. However, peculiarities pertaining to the ionospheric response to prompt penetration electric field in the Indian sector vis-a-vis earlier reports from American sector will be discussed.

  20. Millennial-scale interhemispheric asymmetry of low-latitude precipitation: Speleothem evidence and possible high-latitude forcing

    Science.gov (United States)

    Wang, Xianfeng; Edwards, R. Lawrence; Auler, Augusto S.; Cheng, Hai; Ito, Emi

    During the last glacial period, global climate was characterized by numerous millennial-scale abrupt changes. Mechanisms of these events, however, are not yet resolved. Here, we use phasing information between climate records from different localities to distinguish between mechanisms. We establish a 90,000 year-long oxygen isotopic record of cave calcite, with our previously reported and newly obtained data from Caverna Botuverá, southern Brazil. The record was precisely dated with uranium-series methods. Using independent absolute-dated chronologies, we compare the southern Brazil record with contemporaneous oxygen isotopic records of cave calcite from eastern China and the record of speleothem growth periods from northeastern Brazil. Our record anti-correlates remarkably with the eastern China profile, while it correlates positively with the northeastern Brazil one, on both millennial and orbital scales. Thus, rainfall patterns are antiphased between southern Brazil and eastern China but in-phase between the two Brazilian regions. The in-phase Brazilian relationship argues against a Super El Niño-Southern Oscillation (Super-ENSO) mechanism as modern rainfall at these sites is out of phase during ENSO years. Rather, the relationship among the three records is likely related to displacement in the mean position of the intertropical convergence zone and associated asymmetry in Hadley circulation, which leads to an interhemispheric anti-phasing of rainfall between the southern and northern low latitudes. The abrupt climate events during the last glacial-interglacial cycle are probably triggered by meridional overturning circulation changes initiated in the high latitudes and then amplified through air-sea dynamics, resulting in the observed pattern of low-latitude precipitation.

  1. Asfotase alfa therapy for children with hypophosphatasia.

    Science.gov (United States)

    Whyte, Michael P; Madson, Katherine L; Phillips, Dawn; Reeves, Amy L; McAlister, William H; Yakimoski, Amy; Mack, Karen E; Hamilton, Kim; Kagan, Kori; Fujita, Kenji P; Thompson, David D; Moseley, Scott; Odrljin, Tatjana; Rockman-Greenberg, Cheryl

    2016-06-16

    Background. Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) of the gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Consequently, cell-surface deficiency of TNSALP phosphohydrolase activity leads to extracellular accumulation of inorganic pyrophosphate, a natural substrate of TNSALP and inhibitor of mineralization. Children with HPP can manifest rickets, skeletal pain, deformity, fracture, muscle weakness, and premature deciduous tooth loss. Asfotase alfa is a recombinant, bone-targeted, human TNSALP injected s.c. to treat HPP. In 2012, we detailed the 1-year efficacy of asfotase alfa therapy for the life-threatening perinatal and infantile forms of HPP. Methods. Here, we evaluated the efficacy and safety of asfotase alfa treatment administered to children 6-12 years of age at baseline who were substantially impaired by HPP. Two radiographic scales quantitated HPP skeletal disease, including comparisons to serial radiographs from similarly affected historical control patients. Results. Twelve children receiving treatment were studied for 5 years. The 6-month primary endpoint was met, showing significant radiographic improvement. Additional significant improvements included patient growth, strength, motor function, agility, and quality of life, which for most patients meant achieving normal values for age- and sex-matched peers that were sustained at 5 years of treatment. For most, pain and disability resolved. Mild to moderate injection-site reactions were common and were sometimes associated with lipohypertrophy. Low anti-asfotase alfa antibody titers were noted in all patients. No evidence emerged for clinically important ectopic calcification or treatment resistance. Conclusions. Asfotase alfa enzyme replacement therapy has substantial and sustained efficacy with a good safety profile for children suffering from HPP. Trial Registration. ClinicalTrials.gov NCT00952484 (https://clinicaltrials.gov/ct2/show

  2. Asfotase alfa therapy for children with hypophosphatasia

    Science.gov (United States)

    Madson, Katherine L.; Phillips, Dawn; Reeves, Amy L.; McAlister, William H.; Yakimoski, Amy; Mack, Karen E.; Hamilton, Kim; Kagan, Kori; Fujita, Kenji P.; Thompson, David D.; Moseley, Scott; Odrljin, Tatjana; Rockman-Greenberg, Cheryl

    2016-01-01

    Background. Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) of the gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Consequently, cell-surface deficiency of TNSALP phosphohydrolase activity leads to extracellular accumulation of inorganic pyrophosphate, a natural substrate of TNSALP and inhibitor of mineralization. Children with HPP can manifest rickets, skeletal pain, deformity, fracture, muscle weakness, and premature deciduous tooth loss. Asfotase alfa is a recombinant, bone-targeted, human TNSALP injected s.c. to treat HPP. In 2012, we detailed the 1-year efficacy of asfotase alfa therapy for the life-threatening perinatal and infantile forms of HPP. Methods. Here, we evaluated the efficacy and safety of asfotase alfa treatment administered to children 6–12 years of age at baseline who were substantially impaired by HPP. Two radiographic scales quantitated HPP skeletal disease, including comparisons to serial radiographs from similarly affected historical control patients. Results. Twelve children receiving treatment were studied for 5 years. The 6-month primary endpoint was met, showing significant radiographic improvement. Additional significant improvements included patient growth, strength, motor function, agility, and quality of life, which for most patients meant achieving normal values for age- and sex-matched peers that were sustained at 5 years of treatment. For most, pain and disability resolved. Mild to moderate injection-site reactions were common and were sometimes associated with lipohypertrophy. Low anti–asfotase alfa antibody titers were noted in all patients. No evidence emerged for clinically important ectopic calcification or treatment resistance. Conclusions. Asfotase alfa enzyme replacement therapy has substantial and sustained efficacy with a good safety profile for children suffering from HPP. Trial Registration. ClinicalTrials.gov NCT00952484 (https://clinicaltrials.gov/ct2/show

  3. Low frequency modulation of transionospheric radio wave amplitude at low-latitudes: possible role of field line oscillations

    Directory of Open Access Journals (Sweden)

    A. K. Sinha

    Full Text Available Ionospheric scintillations of radio waves at low-latitudes are associated with electron density irregularities. These irregularities are field-aligned and can provide excitation energy all along the field line to non-local field-aligned oscillations, such as the local field line oscillations. Eigen-periods of toroidal field line oscillations at low-latitudes, computed by using the dipole magnetic field and ion distributions obtained from the International Reference Ionosphere (IRI for typical nighttime conditions, fall in the range of 20–25 s. When subjected to spectral analysis, signal strength of the radio waves recorded on the 250 MHz beacon at Pondicherry (4.5° N dip, Mumbai (13.4° N dip and Ujjain (18.6° N dip exhibit periodicities in the same range. For the single event for which simultaneous ground magnetic data were available, the geomagnetic field also oscillated at the same periodicity. The systematic presence of a significant peak in the 20–25 s range during periods of strong radio wave scintillations, and its absence otherwise suggests the possibility that field line oscillations are endogenously excited by the irregularities, and the oscillations associated with the excited field line generate the modulation characteristics of the radio waves received on the ground. The frequency of modulation is found to be much lower than the characteristic frequencies that define the main body of scintillations, and they probably correspond to scales that are much larger than the typical Fresnel scale. It is possible that the refractive mechanism associated with larger scale long-lived irregularities could be responsible for the observed phenomenon. Results of a preliminary numerical experiment that uses a sinusoidal phase irregularity in the ionosphere as a refracting media are presented. The results show that phase variations which are large enough to produce a focal plane close to the ground can reproduce features that are not

  4. Characteristics of low latitude ionospheric E-region irregularities linked with daytime VHF scintillations measured from Varanasi

    Indian Academy of Sciences (India)

    K Patel; A K Singh; R P Patel; R P Singh

    2009-12-01

    VHF amplitude scintillations recorded during the daytime period from January 1991 to December 1993, April 1998 to December 1999 and January 2008 to December 2008 at low latitude station Varanasi (geographic lat. = 25° 15′N; long. = 82° 59′E; geomagnetic lat. = 14° 55′N, long. = 154°E, dip angle = 37.3°, sub-ionospheric dip = 34°) have been analyzed to study the behaviour of ionospheric E-region irregularities during the active solar and magnetic periods. The autocorrelation functions, power spectral densities, signal de-correlation times are computed to study the temporal features of ionospheric E-region irregularities linked with daytime scintillations. Derived spectral index ranges between −2 and −9. Assuming velocity of irregularities, the characteristic lengths of the E-region irregularities are estimated. We have estimated the minimum and maximum range of scale length of sporadic-E () irregularities to be observed over Varanasi. These results are in close agreement with those reported from this latitude region.

  5. Effects of geomagnetic storm on low latitude ionospheric total electron content: A case study from Indian sector

    Indian Academy of Sciences (India)

    Monti Chakraborty; Sanjay Kumar; Barin Kumar De; Anirban Guha

    2015-07-01

    The effect of geomagnetic storms on low latitude ionosphere has been investigated with the help of Global Positioning System Total Electron Content (GPS-TEC) data. The investigation has been done with the aid of TEC data from the Indian equatorial region, Port Blair (PBR) and equatorial ionization anomaly region, Agartala (AGR). During the geomagnetic storms on 24th April and 15th July 2012, significant enhancement up to 150% and depression up to 72% in VTEC is observed in comparison to the normal day variation. The variations in VTEC observed from equatorial to EIA latitudes during the storm period have been explained with the help of electro-dynamic effects (prompt penetration electric field (PPEF) and disturbance dynamo electric field (DDEF)) as well as mechanical effects (storm-induced equatorward neutral wind effect and thermospheric composition changes). The current study points to the fact that the electro-dynamic effect of geomagnetic storms around EIA region is more effective than at the lower latitude region. Drastic difference has been observed over equatorial region (positive storm impact) and EIA region (negative storm impact) around same longitude sector, during storm period on 24th April. This drastic change as observed in GPS-TEC on 24th April has been further confirmed by using the O/N2 ratio data from GUVI (Global Ultraviolet Imager) as well as VTEC map constructed from IGS data. The results presented in the paper are important for the application of satellite-based communication and navigational system.

  6. Field-aligned current associated with low-latitude plasma blobs as observed by the CHAMP satellite

    Directory of Open Access Journals (Sweden)

    J. Park

    2010-03-01

    Full Text Available Here we give two examples of low-latitude plasma blobs accompanied by linearly polarized perpendicular magnetic deflections which imply that associated field-aligned currents (FACs have a 2-D sheet structure located at the blob walls. The estimated FAC density is of the order of 0.1 μA/m2. The direction of magnetic deflections points westward of the magnetic meridian and there is a linear correlation between perpendicular and parallel variations. All these properties are similar to those of equatorial plasma bubbles (EPBs. According to CHAMP observations from August 2000 to July 2004, blobs show except for these two good examples no clear signatures of 2-D FAC sheets at the walls. Generally, perpendicular magnetic deflections inside blobs are weaker than inside EPBs on average. Our results are consistent with existing theories: if a blob exists, (1 a significant part of EPB FAC will be closed through it, exhibiting similar perpendicular magnetic deflection inside EPBs and blobs, (2 the FAC closure through blobs leads to smaller perpendicular magnetic deflection at its poleward/downward side, and (3 superposition of different FAC elements might result in a complex magnetic signature around blobs.

  7. Response of the equatorial and low-latitude ionosphere during the space weather events of April 2002

    Directory of Open Access Journals (Sweden)

    W. L. C. Lima

    2004-09-01

    Full Text Available A digital ionosonde, of the type known as Canadian Advanced Digital Ionosonde (CADI, has been in routine operation at São José dos Campos (23.2° S, 45.9° W; dip latitude 17.6° S, Brazil, since August 2000. A new CADI was installed at Palmas (10.2° S, 48.2° W; dip latitude 5.5° S, Brazil, in April 2002. The two CADIs are part of a new network being established in a collaborative program between UNIVAP and CEULP/ULBRA, to study the equatorial and low-latitude ionospheric regions in Brazil. In this paper we present and discuss the effects of the space weather events during 17-20 April 2002, as evidenced by the ionospheric parameter changes from simultaneous observations at São José dos Campos and Palmas. A comparison of the observed ionospheric parameters (h'F, hpF2 and foF2 at the two stations, separated only by about 1460km, shows both similarities and differences associated with the geomagnetic disturbances. Also, a comparison of the observed F-region parameters with the ASPEN-TIMEGCM model results is presented. The model results show reasonable agreement during the quiet period of observations, but some discrepancies have been observed during the geomagnetic disturbances.

  8. Observations at Low Latitudes of Magnetic Merging Signatures Within a Flux Transfer Event During a Northward IMF

    Science.gov (United States)

    Chandler, M. O.; Avanov, L. A.

    2003-01-01

    Flux transfer events (FTE) have been postulated to result from transient magnetic merging. If so, the ion distributions within an event should exhibit features known to result from merging. Observations of a FTE by instruments on the Polar spacecraft revealed classical merging signatures that included: 1) D-shaped, accelerated, magnetosheath ion distributions, 2) a well defined de Hoffman-Teller frame, 3) local stress balance, and 4) a P-N magnetic field signature. This FTE was observed near the magnetic equator at approx. 13 MLT under conditions of a moderately northward interplanetary magnetic field (IMF) (clock angle of less than 10 deg). The nature of the ion distributions and the consistency of the measured cutoff speed with that calculated from the measured local magnetic field and the derived de Hoffman-Teller speed show the ion injection to be local. Coupled with the northward IMF these results lead to the conclusion that component merging in the low latitude region was responsible for the FTE.

  9. Statistical description of low-latitude plasma blobs as observed by DMSP F15 and KOMPSAT-1

    Science.gov (United States)

    Park, J.; Min, K. W.; Kim, V. P.; Kil, H.; Kim, H. J.; Lee, J. J.; Lee, E.; Kim, S. J.; Lee, D. Y.; Hairston, M.

    The global distribution of low-latitude plasma blobs was investigated by in-situ plasma density measurements from the Korea Multi-Purpose Satellite-1 (KOMPSAT-1) and Defense Meteorological Satellite Program (DMSP) F15. In the observations, blobs occurred in the longitude sector where the activity of the equatorial plasma bubble (EPB) was appreciable, and additional blobs were found at the lower (KOMPSAT-1) altitude as in the EPBs. However, several notable differences exist between the distributions of EPBs and blobs. First, KOMPSAT-1 found few blobs around 0°E in March and June, as did DMSP F15 from 30°W to 120°E for every season. Second, the overall occurrences in December and March at the DMSP F15 (840 km) altitude were somewhat lower than expected from those of the EBPs. Third, at the DMSP F15 altitude, the occurrence probability of plasma blobs was less controlled by yearly variations in the solar activity. These results imply that topside ionospheric conditions as well as the existence of EPBs control further development of blobs. Additionally, it was found that the blob latitudes became higher as the yearly solar activity increased. Moreover, most of the blobs were encountered in the winter hemisphere, possibly due to the low ambient density.

  10. Development of a middle and low latitude theoretical ionospheric model and an observation system data assimilation experiment

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    On the basis of previous work,we develop a middle and low latitude theoretical ionospheric model in this paper,named Theoretical lonospheric Model of the Earth in the InstRute of Geology and Geophysics,Chinese Academy of Sciences(TIME-IGGCAS).TIME-IGGCAS solves the equations of mass continuity,motion and energy of electron and ions self-consistently and uses an eccentric dipole field approximation to the Earth's magnetic field.We combine the Eulerian and Lagrangian approaches in the model and take account of the plasma ExB drift velocity.Calculation results reveal that the model is steady and credible and can reproduce most large-scale features of ionosphere.By using TIME-IGGCAS,we carried out an observation system data assimilation experiment.Assimilation results show that the ExB drift velocity can be accurately estimated by ingesting the observed foF2 and hmF2 into the model applying nonlinear least-square fit method.We suggest that this work is of great significance in the development of ionospheric data assimilation model to give better nowcast and forecast of ionosphere.

  11. Antarctic-type blue whale calls recorded at low latitudes in the Indian and eastern Pacific Oceans

    Science.gov (United States)

    Stafford, Kathleen M.; Bohnenstiehl, DelWayne R.; Tolstoy, Maya; Chapp, Emily; Mellinger, David K.; Moore, Sue E.

    2004-10-01

    Blue whales, Balaenoptera musculus, were once abundant around the Antarctic during the austral summer, but intensive whaling during the first half of the 20th century reduced their numbers by over 99%. Although interannual variability of blue whale occurrence on the Antarctic feeding grounds was documented by whalers, little was known about where the whales spent the winter months. Antarctic blue whales produce calls that are distinct from those produced by blue whales elsewhere in the world. To investigate potential winter migratory destinations of Antarctic blue whales, we examined acoustic data for these signals from two low-latitude locales: the eastern tropical Pacific Ocean and the Indian Ocean. Antarctic-type blue whale calls were detected on hydrophones in both regions during the austral autumn and winter (May-September), with peak detections in July. Calls occurred over relatively brief periods in both oceans, suggesting that there may be only a few animals migrating so far north and/or producing calls. Antarctic blue whales appear to use both the Indian and eastern Pacific Oceans concurrently, indicating that there is not a single migratory destination. Acoustic data from the South Atlantic and from mid-latitudes in the Indian or Pacific Oceans are needed for a more global understanding of migratory patterns and destinations of Antarctic blue whales.

  12. Projected changes of the low-latitude north-western Pacific wind-driven circulation under global warming

    Science.gov (United States)

    Duan, Jing; Chen, Zhaohui; Wu, Lixin

    2017-05-01

    Based on the outputs of 25 models participating in the Coupled Model Intercomparison Project Phase 5, the projected changes of the wind-driven circulation in the low-latitude north-western Pacific are evaluated. Results demonstrate that there will be a decrease in the mean transport of the North Equatorial Current (NEC), Mindanao Current, and Kuroshio Current in the east of the Philippines, accompanied by a northward shift of the NEC bifurcation Latitude (NBL) off the Philippine coast with over 30% increase in its seasonal south-north migration amplitude. Numerical simulations using a 1.5-layer nonlinear reduced-gravity ocean model show that the projected changes of the upper ocean circulation are predominantly determined by the robust weakening of the north-easterly trade winds and the associated wind stress curl under the El Niño-like warming pattern. The changes in the wind forcing and intensified upper ocean stratification are found equally important in amplifying the seasonal migration of the NBL.

  13. Arecibo Pulsar and Transient Surveys Using ALFA

    Science.gov (United States)

    Cordes, J. M.

    2008-02-01

    A large scale survey for pulsars and transients is being conducted at the Arecibo Observatory using the Arecibo L-band Feed Array (ALFA). Data acquisition so far has been with correlation spectrometers that analyze a 0.1 GHz bandwidth at 1.4 GHz. The 256 frequency channels limit dispersion smearing to 1.2 ms at DMmax = 103 pc cm-3 while the sampling interval of 64 μs equals the dispersion smearing at DM~54 pc cm-3, providing high sensitivity to millisecond pulsars with standard periods out to implied distances of several kpc at low Galactic latitudes. In early 2008, we will use a new set of polyphase filter bank systems that provide the same time and frequency resolutions but over ALFA's full 0.3 GHz bandwidth. Currently the survey covers sky positions within 5° of the Galactic plane that are reachable with Arecibo. Preliminary results are given for some of the discoveries made so far, which include millisecond pulsars, a relativistic binary pulsar, a likely counterpart of a Compton GRO/EGRET gamma-ray source, and transient pulsars (including `RRATs''). We discuss the methodology of the survey, which includes archival of raw survey data at the Cornell Center for Advanced Computing and processing at distributed sites. The survey and follow up observations, which include timing observations, multiwavelength searches for orbital companions in the case of binary pulsars, etc. are organized through the Pulsar-ALFA (PALFA) Consortium. We expect the Galactic plane survey to continue until at least 2010, most likely involving multiple passes on each sky position to optimize detection of variable sources. The ALFA system will also be used to survey intermediate Galactic latitudes for millisecond pulsars, relativistic binaries with large systemic velocities, and runaway pulsars that will escape the Galaxy.

  14. Measurement of elastic scattering with ALFA

    CERN Document Server

    Jakobsen, S; The ATLAS collaboration

    2012-01-01

    The principal of ALFA is presented and then a detailed description of the detector, installation, triggering and beam based alignment. All this was needed in 2011 before the special optics runs with beta* = 90 m which was used for measuring elastic scattering. The first analysis steps of seeing tack patterns, making a global alignment of the detectors and finding correlations are presented. The plans for upcoming runs in 2012 are briefly discussed.

  15. Modeling storm-time electrodynamics of the low-latitude ionosphere thermosphere system: Can long lasting disturbance electric fields be accounted for?

    Science.gov (United States)

    Maruyama, Naomi; Sazykin, Stanislav; Spiro, Robert W.; Anderson, David; Anghel, Adela; Wolf, Richard A.; Toffoletto, Frank R.; Fuller-Rowell, Timothy J.; Codrescu, Mihail V.; Richmond, Arthur D.; Millward, George H.

    2007-07-01

    Storm-time ionospheric disturbance electric fields are studied for two large geomagnetic storms, March 31, 2001 and April 17 18, 2002, by comparing low-latitude observations of ionospheric plasma drifts with results from numerical simulations based on a combination of first-principles models. The simulation machinery combines the Rice convection model (RCM), used to calculate inner magnetospheric electric fields, and the coupled thermosphere ionosphere plasmasphere electrodynamics (CTIPe) model, driven, in part, by RCM-computed electric fields. Comparison of model results with measured or estimated low-latitude vertical drift velocities (zonal electric fields) shows that the coupled model is capable of reproducing measurements under a variety of conditions. In particular, our model results suggest, from theoretical grounds, a possibility of long-lasting penetration of magnetospheric electric fields to low latitudes during prolonged periods of enhanced convection associated with southward-directed interplanetary magnetic field, although the model probably overestimates the magnitude and duration of such penetration during extremely disturbed conditions. During periods of moderate disturbance, we found surprisingly good overall agreement between model predictions and data, with penetration electric fields accounting for early main phase changes and oscillations in low-latitude vertical drift, while the disturbance dynamo mechanism becomes increasingly important later in the modeled events. Discrepancies between the model results and the observations indicate some of the difficulties in validating these combined numerical models, and the limitations of the available experimental data.

  16. Nighttime D-region electron density measurements from ELF-VLF tweek radio atmospherics recorded at low latitudes

    Science.gov (United States)

    Maurya, A. K.; Veenadhari, B.; Singh, R.; Kumar, S.; Cohen, M.

    2012-12-01

    Dispersive atmospherics (tweeks) observed during 2010 simultaneously at two low latitude stations, Allahabad (geomagnetic lat., 16.79° N) and Nainital (geomagnetic lat. 20.48° N), have been utilized to estimate the nighttime D-region electron density at the ionospheric reflection height under the local nighttime propagation (21:00 - 02:00 LT or 15:30 - 20:30 UT). The analysis of simultaneously recorded tweeks at both the stations on five international quiet days during one month each from summer (June), winter (January) and equinox (March) seasons shows that the D-region electron density varies 21.5-24.5 cm-3 over the ionospheric reflection height of 85-95 km. The average values of Wait lower ionospheric parameters: ionospheric reference height h‧ and sharpness factor β are almost same during winter (86.1-85.9 km, 0.51-0.52 km-1) and equinox (85.6-85.7 km, 0.54 km-1) seasons. The values of h‧ and β during summer season are about 83.5 km and 0.60 km-1 at both stations. Overall, equivalent electron density profile obtained using tweek method shows lower values of electron density by about 5-60% than those obtained using IRI-2007 model and lower/higher by 2-68% than those obtained using rocket technique. The electron density estimated using all three techniques (tweek, IRI 2007, Rocket) is consistent in the altitude range of 82-98 km. The estimated geographic locations of causative lightnings of tweeks were matched with the locations and times of lightnings detected by the World-Wide Lightning Location Network (WWLLN). The WWLLN detected about 27.5% of causative lightnings of tweeks simultaneously observed at both the stations.

  17. Assessment of IRI and IRI-Plas models over the African equatorial and low-latitude region

    Science.gov (United States)

    Adebiyi, S. J.; Adimula, I. A.; Oladipo, O. A.; Joshua, B. W.

    2016-07-01

    A reliable ionospheric specification by empirical models is important to mitigate the effects of the ionosphere on the operations of satellite-based positioning and navigation systems. This study evaluates the capability of the International Reference Ionosphere (IRI) and IRI extended to the plasmasphere (IRI-Plas) models in predicting the total electron content (TEC) over stations located in the southern hemisphere of the African equatorial and low-latitude region. TEC derived from Global Positioning System (GPS) measurements were compared with TEC predicted by both the IRI-Plas 2015 model and the three topside options of the IRI 2012 model (i.e., NeQuick (NeQ), IRI 2001 corrected factor (IRI-01 Corr), and the IRI 2001(IRI-01)). Generally, the diurnal and the seasonal structures of modeled TEC follow quite well with the observed TEC in all the stations, although with some upward and downward offsets observed during the daytime and nighttime. The prediction errors of both models exhibit latitudinal variation and these showed seasonal trends. The values generally decrease with increase in latitude. The TEC data-model divergence of both models is most significant at stations in the equatorial region during the daytime and nighttime. Conversely, both models demonstrate most pronounced convergence during the nighttime at stations outside the equatorial region. The IRI-Plas model, in general, performed better in months and seasons when the three options of the IRI model underestimate TEC. Factors such as the height limitation of the IRI model, the inaccurate predictions of the bottomside and topside electron density profiles were used to explain the data-model discrepancies.

  18. Studies of Total Electron Content variations at low-latitude stations within the Equatorial Ionization Anomaly zone

    Science.gov (United States)

    Lilian, Olatunbosun

    2016-07-01

    The total electron content (TEC) is an important parameter to monitor for possible space weather impacts. The radio waves that pass through the earth's ionosphere travel more slowly than their free space velocity due to group path delay of the ionosphere. This group path delay is directly proportional to the TEC of the ionosphere. Using dual frequency GPS receiver at low latitude stations of Ile-Ife (7.52oN, 4.28oE), Addis Ababa (9.04oN, 38.77oE) and Bangalore (13.03oE, 77.57oE), all located within 0 - 15oN of the equatorial anomaly region, the measurement of ionospheric TEC for 2012 has been carried out. The data from the three stations were used to study the diurnal, monthly and seasonal variations of TEC. The diurnal variations maximize between 10:00 - 16:00UT, 08:00 - 14:00UT and 06:00 - 12:00UT for Ile-Ife, Addis Ababa and Bangalore stations respectively. The diurnal variations showed wave-like pertubation during disturbed and quiet periods at Bangalore and Addis Ababa stations. The monthly average TEC variations showed that the month of March recorded the highest TEC value of ~59TECu at about 16:00UT in Ile-Ife station, while TEC at Addis Ababa and Bangalore maximize in October with ~72TECu and 65TECu at about 11:00UT and 09:00UT respectively. Seasonal variations showed that TEC maximizes during the equinoctial months and least in summer, over the three stations. Keywords: Total Electron Content, Equatorial Ionization Anomaly, Global Positioning System co-author:E.A. Ariyibi(Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria)

  19. Coupling of Pi2 wave energy in the inner magnetosphere as inferred from low-latitude ground observations

    Institute of Scientific and Technical Information of China (English)

    HAN DeSheng; YANG HuiGen; CHEN ZhuoTian; C. P. NIELSEN

    2008-01-01

    Taking advantage of high time-resolution (1 s) geomagnetic field measurements obtained at low-latitude stations, we investigated frequency differences of Pi2 pul-sations between the dayside and the nightside. Firstly, we examined two Pi2 cases globally observed by multiple ground stations and found that the dominant fre-quency peaks at the dayside showed latitudinal dependence, I.e., the higher (lower) frequency peak was predominant at lower (higher) latitude. We also noticed that the dominant Pi2 frequency on the nightaide was apparently higher than that on the dayside. We argue that the multiple frequency peaks observed on the ground are harmonics of a plasmaspheric cavity resonance mode (CRM) and that the latitu-dinal dependence of the dominant frequency peaks may result from the energy coupling between the CRM and field line resonance (FLR) occurred in the near Earth space. We also argue that the frequency difference between the dayside and the nightaide could be caused by the reason that a higher harmonic was observed in the nightaide plasmasphere but was not effectively observed in the dayside. In addition, we statistically examined 829 Pi2 events that were simultaneously re-corded at Kakioka (KAK, Maglat=27.2°) and Jicamarca (JIC, Maglat=0.0°), the two stations separated by~10 h in local time (LT) and one of them (JIC) is located at the dip equator. We found that the Pi2 frequency observed at KAK on the nightside was higher than that observed at JIC on the dayside on average. After investigating the occurrence histogram of the frequency difference (△f=fJIC-fKAK) for the events si-multaneously observed at KAK and JIC, we found that close to half of the events had the identical frequency (|△f|<1.0 mHz). The statistical results are consistent with the facts reflected by case studies.

  20. Coupling of Pi2 wave energy in the inner magnetosphere as inferred from low-latitude ground observations

    Institute of Scientific and Technical Information of China (English)

    C.; P.; NIELSEN

    2008-01-01

    Taking advantage of high time-resolution (1 s) geomagnetic field measurements obtained at low-latitude stations, we investigated frequency differences of Pi2 pul-sations between the dayside and the nightside. Firstly, we examined two Pi2 cases globally observed by multiple ground stations and found that the dominant fre-quency peaks at the dayside showed latitudinal dependence, i.e., the higher (lower) frequency peak was predominant at lower (higher) latitude. We also noticed that the dominant Pi2 frequency on the nightside was apparently higher than that on the dayside. We argue that the multiple frequency peaks observed on the ground are harmonics of a plasmaspheric cavity resonance mode (CRM) and that the latitu-dinal dependence of the dominant frequency peaks may result from the energy coupling between the CRM and field line resonance (FLR) occurred in the near Earth space. We also argue that the frequency difference between the dayside and the nightside could be caused by the reason that a higher harmonic was observed in the nightside plasmasphere but was not effectively observed in the dayside. In addition, we statistically examined 829 Pi2 events that were simultaneously re-corded at Kakioka (KAK, Maglat=27.2°) and Jicamarca (JIC, Maglat=0.0°), the two stations separated by ~10 h in local time (LT) and one of them (JIC) is located at the dip equator. We found that the Pi2 frequency observed at KAK on the nightside was higher than that observed at JIC on the dayside on average. After investigating the occurrence histogram of the frequency difference (△f=fJIC-fKAK) for the events si-multaneously observed at KAK and JIC, we found that close to half of the events had the identical frequency (|△f |<1.0 mHz). The statistical results are consistent with the facts reflected by case studies.

  1. Performance evaluation of linear time-series ionospheric Total Electron Content model over low latitude Indian GPS stations

    Science.gov (United States)

    Dabbakuti, J. R. K. Kumar; Venkata Ratnam, D.

    2017-10-01

    Precise modeling of the ionospheric Total Electron Content (TEC) is a critical aspect of Positioning, Navigation, and Timing (PNT) services intended for the Global Navigation Satellite Systems (GNSS) applications as well as Earth Observation System (EOS), satellite communication, and space weather forecasting applications. In this paper, linear time series modeling has been carried out on ionospheric TEC at two different locations at Koneru Lakshmaiah University (KLU), Guntur (geographic 16.44° N, 80.62° E; geomagnetic 7.55° N) and Bangalore (geographic 12.97° N, 77.59° E; geomagnetic 4.53° N) at the northern low-latitude region, for the year 2013 in the 24th solar cycle. The impact of the solar and geomagnetic activity on periodic oscillations of TEC has been investigated. Results confirm that the correlation coefficient of the estimated TEC from the linear model TEC and the observed GPS-TEC is around 93%. Solar activity is the key component that influences ionospheric daily averaged TEC while periodic component reveals the seasonal dependency of TEC. Furthermore, it is observed that the influence of geomagnetic activity component on TEC is different at both the latitudes. The accuracy of the model has been assessed by comparing the International Reference Ionosphere (IRI) 2012 model TEC and TEC measurements. Moreover, the absence of winter anomaly is remarkable, as determined by the Root Mean Square Error (RMSE) between the linear model TEC and GPS-TEC. On the contrary, the IRI2012 model TEC evidently failed to predict the absence of winter anomaly in the Equatorial Ionization Anomaly (EIA) crest region. The outcome of this work will be useful for improving the ionospheric now-casting models under various geophysical conditions.

  2. Analysis of the trigger system of the ALFA detectors

    CERN Document Server

    Guerrero Llorente, Alonso

    2015-01-01

    During the CERN Summer Student Programme 2015 two different projects were carried out. Both related with the ALFA subdetector in ATLAS and its trigger system. The frst, and main, project aimed to do an study of the trigger effciency of the ALFA detector at $\\sqrt{s}=8 TeV$ and $\\beta^* = 90m$. The results can be found fully explained in the ATLAS note: "Trigger effciency for the ALFA detector at $\\sqrt{s}=8 TeV$ and $\\beta^* = 90m$". A secondary task consisted on systematical tests of new chips for an update of the ALFA trigger system.

  3. Surface thermal perturbations of the recent past at low latitudes – inferences based on borehole temperature data from Eastern Brazil

    Directory of Open Access Journals (Sweden)

    L. C. C. Benyosef

    2007-08-01

    Full Text Available Borehole temperature data from the eastern parts of Brazil has been examined in an attempt to extract information on surface thermal perturbations of the recent past at low latitudes. Forward models were employed in the analysis of temperature logs from 17 localities and, in addition, Bayesian inverse modeling was carried out for data from 14 selected sites. The model results have allowed determination of the magnitude as well as the duration of ground surface temperature (GST changes in three major geographic zones of Brazil. Prominent among such changes are the warming episodes that occurred over much of the subtropical highland regions in the southeastern parts of Brazil. The present magnitude of GST changes in this region are in the range of 2 to 3.5°C but have had their beginning during the early decades of the 20th century. Nearly similar trends are also seen in temperature-depth profiles of bore holes in the subtropical humid zones of the interior and coastal areas of southern Brazil. The data from semi arid zones of northeast Brazil also indicate occurrence of surface warming events but the magnitudes are in the range of 1.4 to 2.2°C while the duration of the warming event is larger, extending back into the last decades of the 19th century. There are indications that changes in both climate and vegetation cover contribute to variations in GST. Thus the magnitudes of GST variations are relatively large in localities which have undergone changes in vegetation cover. Also there are indications that GST changes are practically insignificant in areas of tropical rain forest. Another important result emerging from model studies is that the climate was relatively cooler during the 17th and 18th centuries. The climate histories, deduced from geothermal data, are found to be consistent with results of available meteorological records in southern Brazil. Comparative studies also indicate that the magnitudes and duration of recent climate changes

  4. Surface thermal perturbations of the recent past at low latitudes – inferences based on borehole temperature data from Eastern Brazil

    Directory of Open Access Journals (Sweden)

    L. C. C. Benyosef

    2007-03-01

    Full Text Available Borehole temperature data from the eastern parts of Brazil has been examined in an attempt to extract information on surface thermal perturbations of the recent past at low latitudes. Forward models were employed in the analysis of temperature logs from 16 localities and, in addition, inverse modeling was carried out for data from 10 selected sites. The model results have allowed determination of the magnitude as well as the duration of ground surface temperature (GST changes in three major geographic zones of Brazil. Prominent among such events are the warming episodes that occurred over much of the subtropical highland regions in the southeastern parts of Brazil. The present magnitude of GST changes in this region are in the range of 2 to 3.5°C but have had their beginning during the early decades of the 20th century. Nearly similar trends are also seen in temperature-depth profiles of bore holes in the subtropical humid zones of the interior and coastal areas of southern Brazil. The data from semi arid zones of northeast Brazil also indicate occurrence of surface warming events but the magnitudes are in the range of 1.4 to 2.2°C while the duration of the warming event is larger, extending back into the last decades of the 19th century. There are indications that changes in both climate and vegetation cover contribute to variations in GST. Thus the magnitudes of GST variations are relatively large in localities which have undergone changes in vegetation cover. Also there are indications that GST changes are practically insignificant in areas of tropical rain forest. Another important result emerging from model studies is that the climate was relatively cooler during the 17th and 18th centuries. The climate histories, deduced from geothermal data, are found to be consistent with results of available meteorological records in southern Brazil. Comparative studies also indicate that the magnitudes and duration of recent climate changes in

  5. Photochemical and microbial transformation of terrestrial dissolved organic matter - Lena River vs. rivers in mid and low latitudes

    Science.gov (United States)

    Vähätalo, A. V.; Aarnos, H.; Paolucci, E. M.; Musibono, D. E.; Khan, S. R.; Gelinas, Y.; Shantz, A.; Huang, Q.; Schneider, W.; Rezende, C. E.; Petrescu, E.; Reader, H. E.

    2012-04-01

    biodegradability model based on a reactivity continuum to the observed biodegradation of DOC. In the dark control samples, the biodegradation of DOC was moderate, but the irradiation speeded up the decomposition of DOC a lot. The potential photodecomposition of DOM can be realized with a few hundred kilometers from the mouth of those rivers discharging to the mid- or low-latitude ocean. For the DOM of Lena River, the potential photodegradation is realized only partially in the receiving Laptev Sea having seasons with no or little solar radiation and additionally covered by sea ice over most of year.

  6. On the Origin of the Crestone Crater: Low-Latitude Periglacial Features in San Luis Valley, Colorado

    Science.gov (United States)

    Schwans, E.; Meng, T. M.; Prudhomme, K.; Morgan, M. L.

    2015-12-01

    this claim. Results indicate that the Crestone Crater and nearby similar structures are relic collapsed hydraulic pingos, formed during Pleistocene periglacial activity. This conclusion provides further insight into periglacial landforms at low latitudes while demonstrating the value of LiDAR analysis of small geologic features on a regional scale.

  7. The INTERBALL-Tail ELECTRON experiment: initial results on the low-latitude boundary layer of the dawn magnetosphere

    Directory of Open Access Journals (Sweden)

    J.-A. Sauvaud

    Full Text Available The Toulouse electron spectrometer flown on the Russian project INTERBALL-Tail performs electron measurements from 10 to 26 000 eV over a 4 solid angle in a satellite rotation period. The INTERBALL-Tail probe was launched on 3 August 1995 together with a subsatellite into a 65° inclination orbit with an apogee of about 30 RE. The INTERBALL mission also includes a polar spacecraft launched in August 1996 for correlated studies of the outer magnetosphere and of the auroral regions. We present new observations concerning the low-latitude boundary layers (LLBL of the magnetosphere obtained near the dawn magnetic meridian. LLBL are encountered at the interface between two plasma regimes, the magnetosheath and the dayside extension of the plasma sheet. Unexpectedly, the radial extent of the region where LLBL electrons can be sporadically detected as plasma clouds can reach up to 5 RE inside the magnetopause. The LLBL core electrons have an average energy of the order of 100 eV and are systematically field-aligned and counterstreaming. As a trend, the temperature of the LLBL electrons increases with decreasing distance to Earth. Along the satellite orbit, the apparent time of occurrence of LLBL electrons can vary from about 5 to 20 min from one pass to another. An initial first comparison between electron- and magnetic-field measurements indicates that the LLBL clouds coincide with a strong increase in the magnetic field (by up to a factor of 2. The resulting strong magnetic field gradient can explain why the plasma-sheet electron flux in the keV range is strongly depressed in LLBL occurrence regions (up to a factor of sim10. We also show that LLBL electron encounters are related to field-aligned current structures and that wide LLBL correspond to northward interplanetary magnetic field. Evidence for LLBL/plasma-sheet electron leakage into the magnetosheath during southward IMF is also presented.

  8. The ALFA ZOA Deep Survey: First Results

    Science.gov (United States)

    McIntyre, T. P.; Henning, P. A.; Minchin, R. F.; Momjian, E.; Butcher, Z.

    2015-07-01

    The Arecibo L-band Feed Array Zone of Avoidance (ALFA ZOA) Deep Survey is the deepest and most sensitive blind H i survey undertaken in the ZOA. ALFA ZOA Deep will cover about 300 square degrees of sky behind the Galactic Plane in both the inner (30^\\circ ≤slant l≤slant 75^\\circ ;b≤slant | 2^\\circ | ) and outer (175^\\circ ≤slant l≤slant 207^\\circ ;-2^\\circ ≤slant b≤slant +1^\\circ ) Galaxy, using the Arecibo Radio Telescope. First results from the survey have found 61 galaxies within a 15 square degree area centered on l=192^\\circ and b = -2°. The survey reached its expected sensitivity of rms = 1 mJy at 9 km s-1 channel resolution, and is shown to be complete above integrated flux, FHi = 0.5 Jy km s-1. The positional accuracy of the survey is 28″ and detections are found out to a recessional velocity of nearly 19,000 km s-1. The survey confirms the extent of the Orion and Abell 539 clusters behind the plane of the Milky Way and discovers expansive voids, at 10,000 and 18,000 km s-1. Twenty-six detections (43%) have a counterpart in the literature, but only two of these have known redshifts. Counterparts are 20% less common beyond vhel = 10,000 km s-1 and 33% less common at extinctions higher than AB = 3.5 mag. The ALFA ZOA Deep survey is able to probe large scale structure beyond redshifts that even the most modern wide-angle surveys have been able to detect in the ZOA at any wavelength.

  9. Stock footage ATLAS-ALFA experiment September 2016

    CERN Multimedia

    2016-01-01

    Stock footage of the ATLAS- ALFA subdetector in the LHC tunnel at IP1 taken during the LHC technical shut-down in September 2016. The ATLAS/ALFA experiment and studies the elastic scattering of protons, which are not observable in normal operation runs. In the elastic scattering process, the two protons survive their encounter intact and only change directions by exchanging momentum.

  10. Morphological features of tweeks and nighttime D region ionosphere at tweek reflection height from the observations in the low-latitude Indian sector

    OpenAIRE

    İnan, Umran Savaş; Maurya, Ajeet K.; Singh, Rajesh ; Veenadhari, B.; Kumar, Sushil ; Cohen, M. B. ; Selvakumaran, R. ; Pant, P.; Singh, A. K. ; Siingh, D.

    2012-01-01

    A total of 19,308 tweeks recorded during April 2007 to March 2008, at Allahabad, a low-latitude station in the Indian sector, has been used to study seasonal occurrence which shows maximum tweek occurrence of about 63% during summer season and about 19% and 18% occurrences during equinox and winter seasons. Maximum occurrence of tweeks during summer season is consistent with the larger number of lightnings detected by World Wide Lightning Location Network in the Indian and Asia...

  11. Ionospheric response to the 2006 sudden stratospheric warming event over the equatorial and low latitudes in the Brazilian sector using GPS observations

    Science.gov (United States)

    de Jesus, R.; Batista, I. S.; Fagundes, P. R.; Venkatesh, K.; de Abreu, A. J.

    2017-02-01

    The main purpose of this paper is to study the response of the ionospheric F-region using GPS-TEC measurements at equatorial and low latitude regions over the Brazilian sector during an sudden stratospheric warming (SSW) event in the year 2006. In this work, we present vertical total electron content (VTEC) and phase fluctuations derived from GPS network in Brazil. The continuous wavelet transform (CWT) was employed to check the periodicities of the ∆VTEC during the SSW event. The results show a strong decrease in VTEC and ∆VTEC values in the afternoon over low latitudes from DOY 05-39 (during the SSW event) mainly after the second SSW temperature peak. The ionospheric ∆VTEC pattern over Brazilian sector shows diurnal and semidiurnal oscillations during the 2006 SSW event. In addition, for the first time, variations in ∆VTEC (low latitude stations) with periods of about 02-08 day have been reported during an SSW event. Using GPS stations located in the Brazilian sector, it is reported for the first time that equatorial ionospheric irregularities were not suppressed by the SSW event.

  12. Sequential combination of glucocorticosteroids and alfa interferon versus alfa interferon alone for HBeAg-positive chronic hepatitis B

    DEFF Research Database (Denmark)

    Mellerup, M T; Krogsgaard, K; Mathurin, P

    2002-01-01

    Chronic hepatitis B has serious effects on morbidity and mortality. Alfa interferon has been shown to increase the rates of HBeAg-clearance as well as seroconversion to anti-HBe, but response rates are unsatisfactory. Glucocorticosteroid pretreatment may increase the response to alfa interferon....

  13. Sequential combination of glucocorticosteroids and alfa interferon versus alfa interferon alone chronic hepatitis B. Protocol for a Cochrane Review

    DEFF Research Database (Denmark)

    Mellerup, M T; Krogsgaard, K; Mathurin, P

    2000-01-01

    Chronic hepatitis B has serious effects on morbidity and mortality. Alfa interferon has been shown to increase the rates of HBeAg-clearance as well as seroconversion to anti-HBe, but response rates are unsatisfactory. Glucocorticosteroid pretreatment may increase the response to alfa interferon....

  14. Sequential combination of glucocorticosteroids and alfa interferon versus alfa interferon alone for HBeAg-positive chronic hepatitis B

    DEFF Research Database (Denmark)

    Mellerup, M T; Krogsgaard, K; Mathurin, P;

    2002-01-01

    Chronic hepatitis B has serious effects on morbidity and mortality. Alfa interferon has been shown to increase the rates of HBeAg-clearance as well as seroconversion to anti-HBe, but response rates are unsatisfactory. Glucocorticosteroid pretreatment may increase the response to alfa interferon....

  15. The ALFA ZOA Deep Survey: First Results

    CERN Document Server

    McIntyre, Travis P; Minchin, Robert F; Momjian, Emmanuel; Butcher, Zhon

    2015-01-01

    The Arecibo L-Band Feed Array Zone of Avoidance (ALFA ZOA) Deep Survey is the deepest and most sensitive blind Hi survey undertaken in the ZOA. ALFA ZOA Deep will cover about 300 square degrees of sky behind the Galactic plane in both the inner (30 deg < l < 75 deg; b < |2 deg|) and outer (175 deg < l < 207 deg; -2 deg < b < +1 deg) Galaxy, using the Arecibo Radio Telescope. First results from the survey have found 61 galaxies within a 15 square degree area centered on l = 192 deg and b = -2 deg. The survey reached its expected sensitivity of rms = 1 mJy at 9 km/s channel resolution, and is shown to be complete above integrated flux, F_HI = 0.5 Jy km/s. The positional accuracy of the survey is 28 arcsec and detections are found out to a recessional velocity of nearly 19,000 km/s. The survey confirms the extent of the Orion and Abell 539 clusters behind the plane of the Milky Way and discovers expansive voids, at 10,000 km/s and 18,000 km/s. 26 detections (43%) have a counterpart in the li...

  16. Solar Wind Activity Dependence of the Occurrence of Field-Line Resonance at low Latitudes (L~1.3)

    Science.gov (United States)

    Takasaki, S.; Kawano, H.; Tanaka, Y.; Yoshikawa, A.; Seto, M.; Iijima, M.; Yumoto, K.

    2002-12-01

    It is known that the field line resonance (FLR below) is caused by hydromagnetic waves in the magnetosphere. The fundamental field line eigenfrequency can be expressed by the magnetic field line length, the magnetic field intensity, and the plasma density at the magnetic field line. We can measure the fundamental field line eigenfrequency by ground-based observation. The field line length and the magnetic field intensity can be calculated from some magnetic field model (such as the IGRF model) of the magnetosphere. Then, it is possible that the plasma density at the magnetic field line is determined by these factors. The final aim of this study is to monitor and study time-dependent changes in the plasmaspheric plasma distributions by using ground magnetic field observations. For this purpose, we are working in the following three research phases. The first phase is to confirm the possibility of identifying FLR at low-latitudes (L~1.3). The second phase is to examine the correlation between FLR and solar wind parameters. The third phase is to estimate the plasma density from the FLR data, and monitor the density in a continuous manner. We are now in the third phase, and we report here the results of the first two phase. In the first phase, in order to investigate features of FLR close to the Earth, we installed three magnetometers in Japan at L~1.3 (at Kawatabi, Zaou, and Iitate), and started observing ULF geomagnetic pulsations. Each adjacent stations are separated in latitude by 50 to 100 km. The magnetic field data from these stations and Kakioka geomagnetic observatory, Japan, were analyzed by using the amplitude-ratio method and the cross-phase method. As a result, we identified FLR events whose frequency decreased with decreasing geomagnetic latitude; we infer that this feature was caused by heavy ion mass loading to low-L field lines. In the second phase, we studied the dependence of the occurrence probability of the above-identified FLR events on solar wind

  17. Role of elosulfase alfa in mucopolysaccharidosis IVA

    Directory of Open Access Journals (Sweden)

    Regier DS

    2016-06-01

    Full Text Available Debra S Regier, Pranoot Tanpaiboon Division of Genetics and Metabolism, Children’s National Medical Center, Washington, DC, USA Abstract: Mucopolysaccharidosis type IVA (MPS IVA or Morquio A is an autosomal recessive lysosomal storage disease which results in a striking skeletal phenotype, but does not negatively impact the intellect of the patient. MPS IVA has a phenotypic continuum that ranges from a severe and rapidly progressing form to a slowly progressive form. The clinical diagnosis is often made in the preschool years based on abnormal bone findings on physical examination and dysplasia on radiographic imaging. Supportive care has been the mainstay in caring for patients. Orthopedic physicians often form the core of the care team due to the early and severe skeletal abnormalities; however, systemic disease is common and requires aggressive monitoring and management. Interdisciplinary care teams often consist of medical geneticists, cardiologists, pulmonary specialists, gastroenterologists, otolaryngologists, audiologists, and ophthalmologists. With the US Food and Drug Administration’s approval of elosulfase alfa, patients >5 years of age now have access to this medication from the time of diagnosis. The clinical trial with once weekly intravenous dosing (2.0 mg/kg per week showed improvement in the 6-minute walk test. The composite end point analysis to evaluate the combining changes from baseline in 6-minute walk test, 3-minute stair climb test, and respiratory function showed that at a dose of 2.0 mg/kg per week, subjects performed better when compared to placebo. This indication was clinically meaningful in the treatment group. The treatment was generally well tolerated, and the uncommon infusion reactions responded well to traditional enzyme replacement therapy infusion reaction management algorithms. Currently, clinical trials are underway to determine the efficacy and safety in MPS IVA patients <5 years of age. Keywords

  18. New method in computer simulations of electron and ion densities and temperatures in the plasmasphere and low-latitude ionosphere

    Directory of Open Access Journals (Sweden)

    A. V. Pavlov

    creation of sunrise electron temperature peaks which are calculated above the ionosonde stations at hmF2 altitudes. We found that the main cooling rates of thermal electrons are electron-ion Coulomb collisions, vibrational excitation of N2 and O2, and rotational excitation of N2. It is shown that the increase in the loss rate of O+(4S ions due to the vibrational excited N2 and O2 leads to the decrease in the calculated NmF2 by a factor of 1.06–1.44 and to the increase in the calculated hmF2, up to the maximum value of 32 km in the low-latitude ionosphere between –30 and +30° of the geomagnetic latitude. Inclusion of vibrationally excited N2 and O2 brings the model and data into better agreement.

    Key words. Ionosphere (equatorial ionosphere; electric fields and currents, plasma temperature and density; ion chemistry and composition; ionosphere-atmosphere interactions; modeling and forecasting

  19. Concentration and 14C Content of Total Organic Carbon and Black Carbon in Small (<100 ug C) Samples from Low-Latitude Alpine Ice Cores

    Science.gov (United States)

    Kehrwald, N. M.; Czimczik, C. I.; Santos, G. M.; Thompson, L. G.; Ziolkowski, L.

    2008-12-01

    Many low latitude glaciers are receding with consequences for the regional energy budget and hydrology. Ice loss has been linked to climate change and the deposition of organic aerosols such as black carbon (BC) which is formed during incomplete combustion. Little is known about how the contents of BC and total organic carbon (TOC) in aerosols change over time and how anthropogenic activities (e.g. land-use change) impact this variability. Low-latitude ice cores are located closer to population centers than polar ice caps and can provide a regional synthesis of TOC and BC variability. Radiocarbon (14C) may be used to partition BC aerosols into fossil (>50 kyrs) and modern sources (e.g. fossil-fuels vs. wildfires). We quantified TOC, BC, and their 14C content in three low-latitude ice cores: Naimona'nyi (30°27'N, 81°91'E) and Dasuopu (28°23'N, 85°43'E), Tibet, and Quelccaya (13°56'S; 70°50'W), Peru. Aerosols (52-256 g ice on filters) were separated into TOC and BC using thermal oxidation (CTO- 375). 14C was measured by AMS. TOC contents were 0.11-0.87, 0.05-0.43, and 0.06-0.19 μg C (g ice) -1 for Naimona'nyi, Dasuopu, and Quelccaya, respectively. BC contents were 18±8, 27±4, and 29±12 %TOC. Procedural blanks were 0.8 ± 0.4 μg C (TOC) and 1.2 ± 0.6 μg C (BC). In ice cores well dated through annual layer counting and/or independent ages (e.g. volcanic horizons) such as Quelccaya, the ability to separate BC from TOC, as well as partition BC into fossil and modern contributions has potential for reconstructing pre- and post-industrial changes in aerosol composition and their impact on the energy budget.

  20. Persistent Longitudinal Variations of Plasma Density and DC Electric Fields in the Low Latitude Ionosphere Observed with Probes on the C/NOFS Satellite

    Science.gov (United States)

    Pfaff, R.; Freudenreich, H.; Klenzing, J.; Rowland, D.; Liebrecht, C.; Bromund, K.; Roddy, P.

    2010-01-01

    Continuous measurements using in situ probes on consecutive orbits of the C/N0FS satellite reveal that the plasma density is persistently organized by longitude, in both day and night conditions and at all locations within the satellite orbit, defined by its perigee and apogee of 401 km and 867 km, respectively, and its inclination of 13 degrees. Typical variations are a factor of 2 or 3 compared to mean values. Furthermore, simultaneous observations of DC electric fields and their associated E x B drifts in the low latitude ionosphere also reveal that their amplitudes are also strongly organized by longitude in a similar fashion. The drift variations with longitude are particularly pronounced in the meridional component perpendicular to the magnetic field although they are also present in the zonal component as well. The longitudes of the peak meridional drift and density values are significantly out of phase with respect to each other. Time constants for the plasma accumulation at higher altitudes with respect to the vertical drift velocity must be taken into account in order to properly interpret the detailed comparisons of the phase relationship of the plasma density and plasma velocity variations. Although for a given period corresponding to that of several days, typically one longitude region dominates the structuring of the plasma density and plasma drift data, there is also evidence for variations organized about multiple longitudes at the same time. Statistical averages will be shown that suggest a tidal "wave 4" structuring is present in both the plasma drift and plasma density data. We interpret the apparent association of the modulation of the E x B drifts with longitude as well as that of the ambient plasma density as a manifestation of tidal forces at work in the low latitude upper atmosphere. The observations demonstrate how the high duty cycle of the C/NOFS observations and its unique orbit expose fundamental processes at work in the low latitude

  1. Daylight photodynamic therapy - Experience and safety in treatment of actinic keratoses of the face and scalp in low latitude and high brightness region*

    Science.gov (United States)

    Galvão, Luiz Eduardo Garcia; Gonçalves, Heitor de Sá; Botelho, Karine Paschoal; Caldas, Juliana Chagas

    2017-01-01

    Daylight photodynamic therapy has been used in countries with high latitudes during the summer for actinic keratoses treatment with reports of similar efficacy to conventional photodynamic therapy. We evaluate its safety in 20 patients in the city of Fortaleza, a local with low latitude and high brightness. Sixteen patients did not report any discomfort due to the procedure. Daylight photodynamic therapy is an easy application method with great tolerability by the patient and has the possibility of being performed throughout the year in these regions. It can mean a promising tool in the control of skin cancer. PMID:28225978

  2. JSC “ALFA-BANK” marketing policy. problems and perspectives

    OpenAIRE

    Kirillov, A.; Kuznetcova, E.; Martirosian, M.

    2013-01-01

    The article is devoted to the results of JSC “Alfa-Bank” consumers’ segmentation and the following complex marketing research. The article suggests the ways of the bank’s marketing policy improvement.

  3. Treatment of anemia with darbepoetin alfa in systolic heart failure

    DEFF Research Database (Denmark)

    Swedberg, Karl; Young, James B; Anand, Inder S

    2013-01-01

    Patients with systolic heart failure and anemia have worse symptoms, functional capacity, and outcomes than those without anemia. We evaluated the effects of darbepoetin alfa on clinical outcomes in patients with systolic heart failure and anemia.......Patients with systolic heart failure and anemia have worse symptoms, functional capacity, and outcomes than those without anemia. We evaluated the effects of darbepoetin alfa on clinical outcomes in patients with systolic heart failure and anemia....

  4. Daytime, low latitude, vertical ExB drift velocities, inferred from ground-based magnetometer observations in the Peruvian, Philippine and Indian longitude sectors under quiet and disturbed conditions

    CERN Document Server

    Anderson, D; Chau, J; Yumoto, K; Bhattacharya, A; Alex, S

    2006-01-01

    Daytime, low latitude, vertical ExB drift velocities, inferred from ground-based magnetometer observations in the Peruvian, Philippine and Indian longitude sectors under quiet and disturbed conditions

  5. A GIS-based assessment of the suitability of SCIAMACHY satellite sensor measurements for estimating reliable CO concentrations in a low-latitude climate.

    Science.gov (United States)

    Fagbeja, Mofoluso A; Hill, Jennifer L; Chatterton, Tim J; Longhurst, James W S

    2015-02-01

    An assessment of the reliability of the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) satellite sensor measurements to interpolate tropospheric concentrations of carbon monoxide considering the low-latitude climate of the Niger Delta region in Nigeria was conducted. Monthly SCIAMACHY carbon monoxide (CO) column measurements from January 2,003 to December 2005 were interpolated using ordinary kriging technique. The spatio-temporal variations observed in the reliability were based on proximity to the Atlantic Ocean, seasonal variations in the intensities of rainfall and relative humidity, the presence of dust particles from the Sahara desert, industrialization in Southwest Nigeria and biomass burning during the dry season in Northern Nigeria. Spatial reliabilities of 74 and 42 % are observed for the inland and coastal areas, respectively. Temporally, average reliability of 61 and 55 % occur during the dry and wet seasons, respectively. Reliability in the inland and coastal areas was 72 and 38 % during the wet season, and 75 and 46 % during the dry season, respectively. Based on the results, the WFM-DOAS SCIAMACHY CO data product used for this study is therefore relevant in the assessment of CO concentrations in developing countries within the low latitudes that could not afford monitoring infrastructure due to the required high costs. Although the SCIAMACHY sensor is no longer available, it provided cost-effective, reliable and accessible data that could support air quality assessment in developing countries.

  6. Investigation of the morphology and Wait's parameter variations of the low-latitude D region ionosphere using the multiple harmonics of tweeks

    Science.gov (United States)

    Tan, Le Minh

    2016-06-01

    Recording the tweeks with a maximum up to eight harmonics using the receiver installed at Tay Nguyen University (12.65° N, 108.02° E) during 2013-2014, we investigated the morphology of the nighttime D-region ionosphere. Tweeks were recorded on 5 quiet nights per month. The results show that the mean reflection height in 2014 (Rz = 79.3) is lower by 3.3 km than that in 2013 (Rz = 64.9). The reflection height at low latitudes is higher than that at high latitudes. The mean reference height h‧ in 2013 is higher about 0.9 km than that in 2014 and the mean sharpness factor β in 2013 is higher by 0.07 km-1 than that in 2014. The short-term variation of reflection heights for tweeks with harmonics m = 1-3 and sunspot number have the negative correlation coefficients. However, the correlations between them are not clear. On some nights, from 19:00-21:00 LT, the reflection height temporal variability shows a moderate to strong negative correlation with the tweek occurrence. This suggests that the reflection height variation may be caused by QE fields generated by lightning discharges. The variations of tweek reflection heights observed during 2013-2014, at low latitudes could be significantly caused by the ionization effect by Lyman- α and Lyman- β coming from geocorona, variation of neutral density, particle precipitations, and by direct energy coupling between lightning and lower ionosphere.

  7. Performance evaluation of GNSS-TEC estimation techniques at the grid point in middle and low latitudes during different geomagnetic conditions

    Science.gov (United States)

    Abe, O. E.; Otero Villamide, X.; Paparini, C.; Radicella, S. M.; Nava, B.; Rodríguez-Bouza, M.

    2017-04-01

    Global Navigation Satellite Systems (GNSS) have become a powerful tool use in surveying and mapping, air and maritime navigation, ionospheric/space weather research and other applications. However, in some cases, its maximum efficiency could not be attained due to some uncorrelated errors associated with the system measurements, which is caused mainly by the dispersive nature of the ionosphere. Ionosphere has been represented using the total number of electrons along the signal path at a particular height known as Total Electron Content (TEC). However, there are many methods to estimate TEC but the outputs are not uniform, which could be due to the peculiarity in characterizing the biases inside the observables (measurements), and sometimes could be associated to the influence of mapping function. The errors in TEC estimation could lead to wrong conclusion and this could be more critical in case of safety-of-life application. This work investigated the performance of Ciraolo's and Gopi's GNSS-TEC calibration techniques, during 5 geomagnetic quiet and disturbed conditions in the month of October 2013, at the grid points located in low and middle latitudes. The data used are obtained from the GNSS ground-based receivers located at Borriana in Spain (40°N, 0°E; mid latitude) and Accra in Ghana (5.50°N, 0.20°E; low latitude). The results of the calibrated TEC are compared with the TEC obtained from European Geostationary Navigation Overlay System Processing Set (EGNOS PS) TEC algorithm, which is considered as a reference data. The TEC derived from Global Ionospheric Maps (GIM) through International GNSS service (IGS) was also examined at the same grid points. The results obtained in this work showed that Ciraolo's calibration technique (a calibration technique based on carrier-phase measurements only) estimates TEC better at middle latitude in comparison to Gopi's technique (a calibration technique based on code and carrier-phase measurements). At the same time

  8. Role of elosulfase alfa in mucopolysaccharidosis IVA

    Science.gov (United States)

    Regier, Debra S; Tanpaiboon, Pranoot

    2016-01-01

    Mucopolysaccharidosis type IVA (MPS IVA or Morquio A) is an autosomal recessive lysosomal storage disease which results in a striking skeletal phenotype, but does not negatively impact the intellect of the patient. MPS IVA has a phenotypic continuum that ranges from a severe and rapidly progressing form to a slowly progressive form. The clinical diagnosis is often made in the preschool years based on abnormal bone findings on physical examination and dysplasia on radiographic imaging. Supportive care has been the mainstay in caring for patients. Orthopedic physicians often form the core of the care team due to the early and severe skeletal abnormalities; however, systemic disease is common and requires aggressive monitoring and management. Interdisciplinary care teams often consist of medical geneticists, cardiologists, pulmonary specialists, gastroenterologists, otolaryngologists, audiologists, and ophthalmologists. With the US Food and Drug Administration’s approval of elosulfase alfa, patients >5 years of age now have access to this medication from the time of diagnosis. The clinical trial with once weekly intravenous dosing (2.0 mg/kg per week) showed improvement in the 6-minute walk test. The composite end point analysis to evaluate the combining changes from baseline in 6-minute walk test, 3-minute stair climb test, and respiratory function showed that at a dose of 2.0 mg/kg per week, subjects performed better when compared to placebo. This indication was clinically meaningful in the treatment group. The treatment was generally well tolerated, and the uncommon infusion reactions responded well to traditional enzyme replacement therapy infusion reaction management algorithms. Currently, clinical trials are underway to determine the efficacy and safety in MPS IVA patients <5 years of age. PMID:27366102

  9. Role of elosulfase alfa in mucopolysaccharidosis IVA.

    Science.gov (United States)

    Regier, Debra S; Tanpaiboon, Pranoot

    2016-01-01

    Mucopolysaccharidosis type IVA (MPS IVA or Morquio A) is an autosomal recessive lysosomal storage disease which results in a striking skeletal phenotype, but does not negatively impact the intellect of the patient. MPS IVA has a phenotypic continuum that ranges from a severe and rapidly progressing form to a slowly progressive form. The clinical diagnosis is often made in the preschool years based on abnormal bone findings on physical examination and dysplasia on radiographic imaging. Supportive care has been the mainstay in caring for patients. Orthopedic physicians often form the core of the care team due to the early and severe skeletal abnormalities; however, systemic disease is common and requires aggressive monitoring and management. Interdisciplinary care teams often consist of medical geneticists, cardiologists, pulmonary specialists, gastroenterologists, otolaryngologists, audiologists, and ophthalmologists. With the US Food and Drug Administration's approval of elosulfase alfa, patients >5 years of age now have access to this medication from the time of diagnosis. The clinical trial with once weekly intravenous dosing (2.0 mg/kg per week) showed improvement in the 6-minute walk test. The composite end point analysis to evaluate the combining changes from baseline in 6-minute walk test, 3-minute stair climb test, and respiratory function showed that at a dose of 2.0 mg/kg per week, subjects performed better when compared to placebo. This indication was clinically meaningful in the treatment group. The treatment was generally well tolerated, and the uncommon infusion reactions responded well to traditional enzyme replacement therapy infusion reaction management algorithms. Currently, clinical trials are underway to determine the efficacy and safety in MPS IVA patients <5 years of age.

  10. A circum-earth shear zone at low-latitudes and episodic large earthquakes in it and the circum-Pacific seismic zone

    Institute of Scientific and Technical Information of China (English)

    MA; Zongjin; DU; Pinren; REN; Jinwei; GAO; Xianglin

    2006-01-01

    Because of the differential motions between the Northern and Southern Hemispheres of the Earth, there exists a motion discordant zone between them. On the surface this zone consists of 13 large faults dominant with strike-slip. We call it a global shear zone at low-latitudes (E system). By statistical analysis of temporal distribution of earthquakes Mw≥7.5 in the E system and the circum-Pacific (P system) during 1900-2003, we find that there exist quasi-episodic and alternative activities in and between these two systems. This phenomenon is likely associated with the half-sphere oscillation in dilation and contraction and the change of the Earth's rotation rate.

  11. Response of nighttime equatorial and low latitude F-region to the geomagnetic storm of August 18, 2003, in the Brazilian sector

    Science.gov (United States)

    Sahai, Y.; Becker-Guedes, F.; Fagundes, P. R.; Lima, W. L. C.; Otsuka, Y.; Huang, C.-S.; Espinoza, E. S.; Pi, X.; de Abreu, A. J.; Bolzan, M. J. A.; Pillat, V. G.; Abalde, J. R.; Pimenta, A. A.; Bittencourt, J. A.

    This paper presents an investigation of geomagnetic storm effects in the equatorial and low latitude F-region in the Brazilian sector during the intense geomagnetic storm on 18 August, 2003 (SSC 14:21 UT on 17/08; ΣKp = 52+; Ap = 108; ∣Dst∣ max = 168 at 1600 UT on 18/08). Simultaneous ionospheric sounding measurements from two stations, viz., Palmas (10.2°S, 48.2°W; dip latitude 5.7°S) and Sao Jose dos Campos (23.2°S, 45.9°W; dip latitude 17.6°S), Brazil, are presented for the nights of 16-17, 17-18 and 18-19 August, 2003 (quiet, disturbed and recovery phases). Both stations are equipped with the Canadian Advanced Digital Ionosonde (CADI). Quiet and disturbed conditions of the F-region ionosphere are compared using data collected from the two stations. The relationship between magnetospheric disturbance and low-latitude ionospheric dynamics, and generation of ionospheric irregularities are discussed. On the disturbed nights (17-18 and 18-19 August), the low latitude station S. J. Campos showed strong enhancements in the F-region critical frequency (foF2), whereas the near equatorial station Palmas showed strong uplifting of the F-layer about 1 h earlier. Normally during the June solstice months (May-August) in the Brazilian sector, large-scale ionospheric irregularities in form of plasma bubbles are rarely observed. On the night of 17-18 August, ionsospheric sounding observations at Palmas showed the presence of bottomside spread-F, whereas on the night of 18-19 August, the observations at Palmas and S. J. Campos showed the presence of plasma bubbles when the storm recovery phase had just started. The complementary GPS data available from several stations in the "Rede Brasileira de Monitoramento Continuo de GPS (Brazilian Network for Continuous GPS Monitoring)" are used to obtain the vertical total electron content (VTEC) and the rate of change of TEC per minute on UT days 18 and 19 August, 2003 and presented. Also, several global ionospheric TEC maps

  12. Study of zonal large scale wave structure (LSWS) and equatorial scintillation with low-latitude GRBR network over Southeast Asia and African sectors

    Science.gov (United States)

    Ram Sudarsanam, Tulasi; Yamamoto, Mamoru; Gurubaran, Subramanian; Tsunoda, Roland

    2012-07-01

    The day-to-day variability of Equatorial Spread-F, when and where the equatorial plasma bubbles (EPBs) may initiate, were the challenging problems that puzzling the space weather researchers for several decades. The zonal large scale wave structure (LSWS) at the base of F-layer is the earliest manifestation of seed perturbation for the evolution of EPBs by R-T instability processes, hence, found to play deterministic role on the development of ESF. Yet, only a little is known about LSWS with lack of sufficient observations, primarily because of inability to detect the LSWS with the currently existing instruments except with steerable incoherent scatter radar such as ALTAIR radar. This situation, however, was recently changed with launch of C/NOFS in a unique low-inclination (13 ^{o}) orbit. With the availability of CERTO beacon transmissions from C/NOFS in a near equatorial orbit, it is now possible to detect and resolve the roles by LSWS on a regular basis. A ground based low-latitude GNU Radio Beacon Receiver (GRBR) Network has been recently established that provide coverage of Southeast Asia, Pacific and African low-latitude regions. Recent observations suggest that these wave structures with zonal wave lengths varying between 200 and 800 km can be earliest detected even before E-region sunset and found to grow significantly after sunset, probably, aided by the polarization electric fields. Further, these zonal structures consistently found to be aligned with field lines for several hundreds of kilometers and EPBs were found to grow from the westward walls of upwellings. The characteristic differences on the strength of LSWS between the Asian and African longitudes were identified during the recent increasing solar activity and discussed in this paper.

  13. Humpback whale "super-groups" - A novel low-latitude feeding behaviour of Southern Hemisphere humpback whales (Megaptera novaeangliae) in the Benguela Upwelling System.

    Science.gov (United States)

    Findlay, Ken P; Seakamela, S Mduduzi; Meÿer, Michael A; Kirkman, Stephen P; Barendse, Jaco; Cade, David E; Hurwitz, David; Kennedy, Amy S; Kotze, Pieter G H; McCue, Steven A; Thornton, Meredith; Vargas-Fonseca, O Alejandra; Wilke, Christopher G

    2017-01-01

    Southern Hemisphere humpback whales (Megaptera novaeangliae) generally undertake annual migrations from polar summer feeding grounds to winter calving and nursery grounds in subtropical and tropical coastal waters. Evidence for such migrations arises from seasonality of historic whaling catches by latitude, Discovery and natural mark returns, and results of satellite tagging studies. Feeding is generally believed to be limited to the southern polar region, where Antarctic krill (Euphausia superba) has been identified as the primary prey item. Non-migrations and / or suspended migrations to the polar feeding grounds have previously been reported from a summer presence of whales in the Benguela System, where feeding on euphausiids (E. lucens), hyperiid amphipods (Themisto gaudichaudii), mantis shrimp (Pterygosquilla armata capensis) and clupeid fish has been described. Three recent research cruises (in October/November 2011, October/November 2014 and October/November 2015) identified large tightly-spaced groups (20 to 200 individuals) of feeding humpback whales aggregated over at least a one-month period across a 220 nautical mile region of the southern Benguela System. Feeding behaviour was identified by lunges, strong milling and repetitive and consecutive diving behaviours, associated bird and seal feeding, defecations and the pungent "fishy" smell of whale blows. Although no dedicated prey sampling could be carried out within the tightly spaced feeding aggregations, observations of E. lucens in the region of groups and the full stomach contents of mantis shrimp from both a co-occurring predatory fish species (Thyrsites atun) and one entangled humpback whale mortality suggest these may be the primary prey items of at least some of the feeding aggregations. Reasons for this recent novel behaviour pattern remain speculative, but may relate to increasing summer humpback whale abundance in the region. These novel, predictable, inter-annual, low latitude feeding events

  14. First Evaluation of the Climatological Calibration Algorithm in the Real-time TMPA Precipitation Estimates over Two Basins at High and Low Latitudes

    Science.gov (United States)

    Yong, Bin; Ren, Liliang; Hong, Yang; Gourley, Jonathan; Tian, Yudong; Huffman, George J.; Chen, Xi; Wang, Weiguang; Wen, Yixin

    2013-01-01

    The TRMM Multi-satellite Precipitation Analysis (TMPA) system underwent a crucial upgrade in early 2009 to include a climatological calibration algorithm (CCA) to its realtime product 3B42RT, and this algorithm will continue to be applied in the future Global Precipitation Measurement era constellation precipitation products. In this study, efforts are focused on the comparison and validation of the Version 6 3B42RT estimates before and after the climatological calibration is applied. The evaluation is accomplished using independent rain gauge networks located within the high-latitude Laohahe basin and the low-latitude Mishui basin, both in China. The analyses indicate the CCA can effectively reduce the systematic errors over the low-latitude Mishui basin but misrepresent the intensity distribution pattern of medium-high rain rates. This behavior could adversely affect TMPA's hydrological applications, especially for extreme events (e.g., floods and landslides). Results also show that the CCA tends to perform slightly worse, in particular, during summer and winter, over the high-latitude Laohahe basin. This is possibly due to the simplified calibration-processing scheme in the CCA that directly applies the climatological calibrators developed within 40 degrees latitude to the latitude belts of 40 degrees N-50 degrees N. Caution should therefore be exercised when using the calibrated 3B42RT for heavy rainfall-related flood forecasting (or landslide warning) over high-latitude regions, as the employment of the smooth-fill scheme in the CCA bias correction could homogenize the varying rainstorm characteristics. Finally, this study highlights that accurate detection and estimation of snow at high latitudes is still a challenging task for the future development of satellite precipitation retrievals.

  15. Integrating both interaction pathways between warming and pesticide exposure on upper thermal tolerance in high- and low-latitude populations of an aquatic insect.

    Science.gov (United States)

    Op de Beeck, Lin; Verheyen, Julie; Stoks, Robby

    2017-05-01

    Global warming and chemical pollution are key anthropogenic stressors with the potential to interact. While warming can change the impact of pollutants and pollutants can change the sensitivity to warming, both interaction pathways have never been integrated in a single experiment. Therefore, we tested the effects of warming and multiple pesticide pulses (allowing accumulation) of chlorpyrifos on upper thermal tolerance (CTmax) and associated physiological traits related to aerobic/anaerobic energy production in the damselfly Ischnura elegans. To also assess the role of latitude-specific thermal adaptation in shaping the impact of warming and pesticide exposure on thermal tolerance, we exposed larvae from replicated high- and low-latitude populations to the pesticide in a common garden rearing experiment at 20 and 24 °C, the mean summer water temperatures at high and low latitudes. As expected, exposure to chlorpyrifos resulted in a lower CTmax. Yet, this pesticide effect on CTmax was lower at 24 °C compared to 20 °C because of a lower accumulation of chlorpyrifos in the medium at 24 °C. The effects on CTmax could partly be explained by reduction of the aerobic scope. Given that these effects did not differ between latitudes, gradual thermal evolution is not expected to counteract the negative effect of the pesticide on thermal tolerance. By for the first time integrating both interaction pathways we were not only able to provide support for both of them, but more importantly demonstrate that they can directly affect each other. Indeed, the warming-induced reduction in pesticide impact generated a lower pesticide-induced climate change sensitivity (in terms of decreased upper thermal tolerance). Our results indicate that, assuming no increase in pesticide input, global warming might reduce the negative effect of multiple pulse exposures to pesticides on sensitivity to elevated temperatures.

  16. The storm-time assessment of GNSS-SBAS performance within low latitude African region using a testbed-like platform

    Science.gov (United States)

    Abe, O. E.; Paparini, C.; Ngaya, R. H.; Otero Villamide, X.; Radicella, S. M.; Nava, B.

    2017-09-01

    A Satellite Based Augmentation System (SBAS) is designed to improve Global Navigation Satellite Systems (GNSS) in terms of integrity, accuracy, availability and continuity. The main limitation to SBAS performance optimization is the ionosphere, and this is more critical in low latitude. During geomagnetically disturbed periods the role of storm-time winds is important because they modify the atmospheric composition toward low latitudes. An index of ionospheric disturbance, the relative percentage of deviation of the vertical Total Electron Content (TEC) from the quiet level (DvTEC) at each station was evaluated to study positive and negative phases of the geomagnetic storms. The rate of change of TEC index (ROTI) over all the GNSS stations was estimated to evaluate equatorial ionospheric gradients and irregularities. From the study it is observed that the positive deviations are more frequent than negative ones. The availability map, which is the mean of the combine Vertical Protection Level (VPL) and Horizontal Protection Level (HPL) are used for the SBAS performance. The cases of moderate and minor storms studied during the months of July and October 2013 showed that the SBAS system performance during the disturbed periods depends on the local time in which the storm occurs, geographic longitude and other phenomena that need further study. During the storm-time conditions considered, three out of seven geomagnetic storms indicated good SBAS performance and exceed monthly average of the availability map, three geomagnetic storms reduced the system performance below monthly average while one does not have effect on SBAS system performance in respect to monthly average. The present study indicates ROTI as a better proxy than geomagnetic indices for the assessment of storm-time effects on GNSS-SBAS performance.

  17. Analysis of geomagnetically induced currents at a low-latitude region over the solar cycles 23 and 24: comparison between measurements and calculations

    Directory of Open Access Journals (Sweden)

    Barbosa Cleiton

    2015-01-01

    Full Text Available Geomagnetically Induced Currents (GIC are a space weather effect, which affects ground-based technological structures at all latitudes on the Earth’s surface. GIC occurrence and amplitudes have been monitored in power grids located at high and middle latitudes since 1970s and 1980s, respectively. This monitoring provides information about the GIC intensity and the frequency of occurrence during geomagnetic storms. In this paper, we investigate GIC occurrence in a power network at low latitudes (in the central Brazilian region during the solar cycles 23 and 24. Calculated and measured GIC data are compared for the most intense geomagnetic storms (i.e. −50 < Dst < −50 nT of the solar cycle 24. The results obtained from this comparison show a good agreement. The success of the model employed for the calculation of GIC leads to the possibility of determining GIC for events during the solar cycle 23 as well. Calculated GIC in one transformer reached ca. 30 A during the “Halloween storm” in 2003 whilst most frequent intensities lie below 10 A. The normalized inverse cumulative frequency for GIC data was calculated for the solar cycle 23 in order to perform a statistical analysis. It was found that a q-exponential Tsallis distribution fits the calculated GIC frequency distribution for more than 99% of the data. This analysis provides an overview of the long-term GIC monitoring at low latitudes and suggests new insight into critical phenomena involved in the GIC generation.

  18. Humpback whale “super-groups” – A novel low-latitude feeding behaviour of Southern Hemisphere humpback whales (Megaptera novaeangliae) in the Benguela Upwelling System

    Science.gov (United States)

    Seakamela, S. Mduduzi; Meÿer, Michael A.; Kirkman, Stephen P.; Barendse, Jaco; Cade, David E.; Hurwitz, David; Kennedy, Amy S.; Kotze, Pieter G. H.; McCue, Steven A.; Thornton, Meredith; Vargas-Fonseca, O. Alejandra; Wilke, Christopher G.

    2017-01-01

    Southern Hemisphere humpback whales (Megaptera novaeangliae) generally undertake annual migrations from polar summer feeding grounds to winter calving and nursery grounds in subtropical and tropical coastal waters. Evidence for such migrations arises from seasonality of historic whaling catches by latitude, Discovery and natural mark returns, and results of satellite tagging studies. Feeding is generally believed to be limited to the southern polar region, where Antarctic krill (Euphausia superba) has been identified as the primary prey item. Non-migrations and / or suspended migrations to the polar feeding grounds have previously been reported from a summer presence of whales in the Benguela System, where feeding on euphausiids (E. lucens), hyperiid amphipods (Themisto gaudichaudii), mantis shrimp (Pterygosquilla armata capensis) and clupeid fish has been described. Three recent research cruises (in October/November 2011, October/November 2014 and October/November 2015) identified large tightly-spaced groups (20 to 200 individuals) of feeding humpback whales aggregated over at least a one-month period across a 220 nautical mile region of the southern Benguela System. Feeding behaviour was identified by lunges, strong milling and repetitive and consecutive diving behaviours, associated bird and seal feeding, defecations and the pungent “fishy” smell of whale blows. Although no dedicated prey sampling could be carried out within the tightly spaced feeding aggregations, observations of E. lucens in the region of groups and the full stomach contents of mantis shrimp from both a co-occurring predatory fish species (Thyrsites atun) and one entangled humpback whale mortality suggest these may be the primary prey items of at least some of the feeding aggregations. Reasons for this recent novel behaviour pattern remain speculative, but may relate to increasing summer humpback whale abundance in the region. These novel, predictable, inter-annual, low latitude feeding

  19. PRELIMINARY STUDY OF INDOOR FEATURES OF TEMPERATURE AND HUMIDITY FOR ROOMS FACING NORTH-SOUTH IN WINTER IN A LOW-LATITUDE PLATEAU CITY

    Institute of Scientific and Technical Information of China (English)

    张一平; 李佑荣; 王进欣; 刘玉洪; 马友鑫

    2002-01-01

    Analyzing observations of wintertime air temperature in both indoor and outdoor surroundings in Kunming,a city lying in low latitudes,characteristics of temperature and humidity have been studied for the interior of rooms facing north-south under different weather conditions.Significant warming effect has been identified in terms of lowest and daily-mean indoor temperature in the area of Kunming.The heating amplitude ranges from 7.7(C to 10.0(C and from 4.6(C to 5.8(C for the interior part of rooms facing the south and from 4.6(C to 7.0(C and from 1.3(C to 4.4(C for the interior part of rooms facing the north,respectively for the two elements.The highest air temperature is higher indoor than outdoor for rooms facing the south,but otherwise is usually true for rooms facing the north.Additional findings point out that buildings not only help maintain relatively warm indoor temperature but delay its variation.The diurnal cycle of temperature indoor is smaller and ranges by 40% ~48% for south-facing rooms,and by 20%~30% for north-facing rooms,than outdoor,and the highest temperature is about 2 hours late inside the room than outside.It shows how inertly indoor temperature varies.The work also finds that relative humidity is less indoor in southward rooms than in northward ones and difference is the largest on fine days but the smallest when it is overcast.For the diurnal variation,the indoor relative humidity is large at nighttime with small amplitude but small during daytime with large amplitude.The above-presented results can be served as scientific foundation for more research on climate in low-latitude cities and rational design of urban architectures.

  20. Vitamin D status in renal transplant recipients living in a low-latitude city: association with body fat, cardiovascular risk factors, estimated glomerular filtration rate and proteinuria.

    Science.gov (United States)

    Rosina, Kelli T C; Menna Barreto, Ana Paula M; Pontes, Karine S S; Martins, Cyro J M; Souza, Edison; Bregman, Rachel; Barreto Silva, Maria Inês; Klein, Márcia R S T

    2017-05-01

    Recent evidence suggests that vitamin D deficiency is associated with CVD, impaired kidney function and proteinuria. To date, no study has evaluated these associations in renal transplant recipients (RTR) adjusting for body adiposity assessed by a 'gold standard' method. This study aimed to evaluate the vitamin D status and its association with body adiposity, CVD risk factors, estimated glomerular filtration rate (eGFR) and proteinuria in RTR, living in Rio de Janeiro, Brazil (a low-latitude city (22°54'10"S)), taking into account body adiposity evaluated by dual-energy X-ray absorptiometry (DXA). This cross-sectional study included 195 RTR (114 men) aged 47·6 (sd 11·2) years. Nutritional evaluation included anthropometry and DXA. Risk factors for CVD were hypertension, diabetes mellitus, dyslipidaemia and the metabolic syndrome. eGFR was evaluated using the Chronic Kidney Disease Epidemiology Collaboration equation. Serum 25-hydroxyvitamin D (25(OH)D) concentration was used to define vitamin D status as follows: 10 % (n 19) had vitamin D deficiency (30 ng/ml). Percentage of body fat (DXA) was significantly associated with vitamin D deficiency independently of age, sex and eGFR. Lower 25(OH)D was associated with higher odds of the metabolic syndrome and dyslipidaemia after adjustment for age, sex and eGFR, but not after additional adjustment for body fat. Hypertension and diabetes were not related to 25(OH)D. Lower serum 25(OH)D was associated with increasing proteinuria and decreasing eGFR even after adjustments for age, sex and percentage of body fat. This study suggests that in RTR of a low-latitude city hypovitaminosis D is common, and is associated with excessive body fat, decreased eGFR and increased proteinuria.

  1. Conestat alfa for the treatment of angioedema attacks

    Directory of Open Access Journals (Sweden)

    Davis B

    2011-07-01

    Full Text Available Benjamin Davis, Jonathan A BernsteinUniversity of Cincinnati College of Medicine, Department of Internal Medicine, Division of Immunology/Allergy Section, Cincinnati, OH, USAAbstract: Recently, multiple C1 inhibitor (C1-INH replacement products have been approved for the treatment of hereditary angioedema (HAE. This review summarizes HAE and its current treatment modalities and focuses on findings from bench to bedside trials of a new C1-INH replacement, conestat alfa. Conestat alfa is unique among the other C1-INH replacement products because it is produced from transgenic rabbits rather than derived from human plasma donors, which can potentially allow an unlimited source of drug without any concern of infectious transmission. The clinical trial data generated to date indicate that conestat alfa is safe and effective for the treatment of acute HAE attacks.Keywords: androgens, adverse events, patients, HAE attacks 

  2. Epoetin alfa ja namaluva nefrotoksicnosta inducirana so cisplatin kaj staorci

    Directory of Open Access Journals (Sweden)

    Dimce Zafirov

    2006-06-01

    Full Text Available Klinickata efikasnost na cisplatin kako antitumorski lek e nesomnena, no dozno-limitiracki faktor za negova upotreba pretstavuva izrazitata nefrotoksicnost. Najnovite istrazuvawa pokazuvaat deka epoetin alfa moze da ima znacajna uloga ne samo vo terapiski celi za korekcija na razni vidovi na anemii, tuku istiot moze da bide efikasen i kako nevroprotektiv, hepatoprotektiv, kardioprotektiv i osobeno znacajno kako nefroprotektiv kaj nefrotoksicnost inducirana od preparati na baza na platina. Glavna cel na ovaa studija bese da se utvrdi efektot na epoetin alfa vo prevencijata na nefrotoksicnost eksperimentalno inducirana so dolgotrajna administracija na cisplatin vo doza od 2 mg/kg/t.t./nedela vo tek na 8 nedeli, kaj Wistar staorci. Dobienite rezultati od ovaa studija pokazuvaat deka epoetin alfa signifikantno gi ublazuva funkcionalnite bubrezni poremetuvawa inducirani so dolgotrajna administracija na cisplatin, ja podobruva opstata sostojba i go namaluva mortalitetot kaj ispituvanite zivotni.

  3. Resolution and t-spectrum for the ALFA detector

    CERN Document Server

    Guergouri, Hichem

    2016-01-01

    My report as Summer Student is in two parts. In the first part I report about my attendance to the run of the ALFA detector to test different collimation schemas and find a new way to get rid of the background. The second part is about the measurement of the resolution of the ALFA detector and comparing the real data with the Monte-Carlo (MC) simulations. First of all I tried to be more familiar with ROOT, worked on understanding the code used to access to the data in the trees inside the Ntuples, plotting histograms,… This was done using old Ntuples which contain MC data.

  4. Darbepoetin alfa once every 2 weeks for treatment of anemia in dialysis patients

    DEFF Research Database (Denmark)

    Mann, J; Kessler, M; Villa, Giulio Palludan

    2007-01-01

    AIM: Darbepoetin alfa has a longer half-life than epoetin-(EPO) alfa or beta, allowing administration at less frequent intervals for the treatment of renal anemia. The aim of the present analysis was to evaluate the efficacy and tolerability of an every-2-week (Q2W) schedule of darbepoetin alfa...

  5. Physics prospects with the ALFA and AFP detectors

    CERN Document Server

    Hamal, Petr; The ATLAS collaboration

    2013-01-01

    The ATLAS ALFA and AFP detectors - the experimental challenge of measuring forward protons at the LHC. We will describe the experimental challenge presented by the measurement of the forward protons at the LHC. The ATLAS ALFA and AFP projects involve the deployment of detectors capable of detecting protons that emerge intact from the interaction with very small scattering angles. In the case of the ALFA detector, located at ±240m from the ATLAS interaction point, this measurement has to be performed using special high \\beta* beam optics. The detector chosen for the task is a nearly edgeless scintillating fibre tracker capable of making measurements at very low t – below 10-3 GeV2 – in the Nuclear Coulomb interference region. In order to reach these very small t-values we need to deploy the detector very near to the beam line utilizing Roman Pots. The main purpose of the ALFA detector is to measure the total p-p cross-section, a fundamental quantity in hadronic physics of importance to particle and to cos...

  6. Astronaut Scott Carpenter practices in the ALFA trainer at Langley

    Science.gov (United States)

    1962-01-01

    Project Mercury Astronaut M. Scott Carpenter practices in the Air Lubricated Free Attitude (ALFA) trainer located at NASA's Manned Spacecraft Center at Langley AFB, Virginia. This trainer allows the astronaut to see the image of the earth's surface at his feet while manually controlling the spacecraft.

  7. A New Approach to the ALFA Trigger Simulator

    CERN Document Server

    Dziedzic, Bartosz

    2016-01-01

    The idea and principle of operation of a device which is used to test the trigger system of the ALFA detectors of the ATLAS experiment at the LHC are discussed. A new approach to the application control is presented. The application runs under control of the ArchLinuxARM operating system. Also, the drawbacks of the new solution are discussed.

  8. Drotrecogin alfa (activated) in adults with septic shock.

    NARCIS (Netherlands)

    Ranieri, V.M.; Thompson, B.T.; Barie, P.S.; Dhainaut, J.F.; Douglas, I.S.; Finfer, S.; Gardlund, B.; Marshall, J.C.; Rhodes, A.; Artigas, A.; Payen, D.; Tenhunen, J.; Al-Khalidi, H.R.; Thompson, V.; Janes, J.; Macias, W.L.; Vangerow, B.; Williams, M.D.; Pickkers, P.; Raemaekers, J.M.

    2012-01-01

    BACKGROUND: There have been conflicting reports on the efficacy of recombinant human activated protein C, or drotrecogin alfa (activated) (DrotAA), for the treatment of patients with septic shock. METHODS: In this randomized, double-blind, placebo-controlled, multicenter trial, we assigned 1697 pati

  9. Climate and Low Latitude Water Cycle Variations Over the Last 300 ka Using Ice Core Records and iLOVECLIM Integration

    Science.gov (United States)

    Extier, Thomas; Landais, Amaelle; Roche, Didier; Bréant, Camille; Bazin, Lucie; Prie, Frederic; François, Louis

    2017-04-01

    The Quaternary is characterized by a succession of glacial and interglacial periods recorded in various climatic archives from high to low latitudes. Antarctic ice cores provide high latitude climate reconstruction from water isotopes as well as global proxy records such as greenhouse gas concentrations. Within global tracers, δ18O of O2 or δ18Oatm is a quite complex tracer which reflects global variations of the low latitude water cycle and vegetation changes. The last two terminations (TI 20-11 ka and TII 136-128 ka) are already well documented and display a high resolution δ18Oatm signal with large amplitude changes, whereas the changes are smaller and poorly documented for the TIII (around 245 ka). Here we display new δ18Oatm data over the last 300 ka on the Dome C ice core in order to compare the δ18Oatm dynamics over the last three terminations. The new high resolution δ18Oatm data covering the Termination III confirm the smaller δ18Oatm amplitude changes compared to TI and TII. Moreover, the δ18Oatm changes of TIII appear to be divided in several steps. The δ18Oatm trapped in Dome C ice cores also shows strong similarity with the 65°N summer insolation and the precession signal on orbital timescales as well as with the δ18Ocalcite measured in the Asian speleothems, suggesting a link with the monsoon dynamics. However, the quantitative interpretation of δ18Oatm is limited by our knowledge of past oxygen fluxes. We present here the first step toward a more quantitative interpretation of δ18Oatm variations through the use of the iLOVECLIM intermediate complexity model with a new vegetation module CARAIB (Warnant et al., 1994; Otto et al., 2002; Laurent et al., 2008; Dury et al., 2011). Through considering more plant functional types (PFTs) and more accurate biosphere productivity variations than the previous module, CARAIB will be helpful to quantify the impact of the biosphere changes on the δ18Oatm.

  10. Solar Flux Effect on the Reproducibility of Global/Local-Time Variations of Ion Density Structure at Low-Latitude Ionosphere

    Science.gov (United States)

    Su, Shin-Yi

    Longitudinal/seasonal (l/s) variations of ion density structures at the 600-km low-latitude ionosphere observed by ROCSAT-1 between two similar solar activity years of 2000 and 2002 are examined at four different local-time (LT) regions. The gross feature of l/s density structure is almost identical to each other at the four LT regions examined. A complete reproducibility of density structure can be assumed, including the shape of equatorial ionization anomaly (EIA), for identical solar flux input that also implicitly affect other atmospheric components such as the neutral O/N2 ratio and neutral wind variation. The fact that the solar variability effect is thought as the ultimate driver to shape the global ionospheric structure can be confirmed with the reproduction of ROCSAT observations with the simulation results of the TIEGCM model runs using the observed solar flux inputs for various seasons. However, the EIA crestto-valley ratio or no-valley signature in this background density structure can not be used to infer the post-sunset irregularity occurrence rates because the l/s variation of the magnetic declination effect that determines the post-sunset ionospheric conductivity for the ionospheric electrodynamics can not be readily obtained from this ionospheric background structure.

  11. Long-term Trends in Mesospheric Temperatures at high and low latitudes derived from OH airglow spectra of Kiruna FTS and Sloan Digital Sky Survey

    Science.gov (United States)

    Kim, Yongha; Kim, Jeong-Han; Kim, Gawon; Lee, Youngsun

    2016-07-01

    We have analyzed mesospheric temperatures from OH airglow measurements with Fourier Transform Spectrometer (FTS) in the period of 2003 - 2012 at Kiruna (67.9°N, 21.1°E). We also derived mesospheric temperatures from rotational emission lines of the OH airglow (8-3) band in the sky spectra of Sloan Digital Sky Survey (SDSS) in the period of 2000 - 2014. The main objective of SDSS is to make a detailed 3-dimensional map of the universe by observing images and spectra of various celestial objects at Apache Point Observatory (APO, 32°N 105°W). From both temperature sets we first estimated the solar responses of mesospheric temperatures to F10.7 variation and the seasonal variation of mesospheric temperatures. After removing the solar response, we found the long-term mesospheric temperature trends of -4 ˜-6.6 K/decade at Kiruna and -0.02 ± 0.7 K/decade at Apache Point. Our results indicate significant cooling trend at the high latitude but very little or no cooling at the low latitude. Although both trends are comparable and consistent with other studies, the temperature trend from SDSS spectra should be regarded as unique contribution to global monitoring of climate change because the SDSS project is completely independent of climate studies.

  12. On the response of the equatorial and low latitude ionospheric regions in the Indian sector to the large magnetic disturbance of 29 October 2003

    Directory of Open Access Journals (Sweden)

    G. Manju

    2009-06-01

    Full Text Available The present paper investigates the response of the equatorial and low latitude ionosphere over the Indian longitudes to the events on 29 October 2003 using ionosonde data at Trivandrum (8.5° N (0.5° N geomagnetic, 77° E and SHAR (13.7° N (5.7° N geomagnetic, 80.2° E, ground-based magnetometer data from Trivandrum and Total Electron Content (TEC derived from GPS data at the locations of Ahmedabad (23° N (15° N geomagnetic, 72° E, Jodhpur (26.3° N (18.3° N geomagnetic, 73° E and Delhi (28° N (20° N geomagnetic, 77° E. Following the storm sudden commencement, the TEC at all the three stations showed an overall enhancement in association with episodes of inter-planetary electric field penetration. Interestingly, real ionospheric height profiles derived using the ionosonde data at both Trivandrum and SHAR showed significant short-term excursions and recoveries. In the post noon sector, these features are more pronounced over SHAR, an off equatorial station, than those over Trivandrum indicating the increased effects of neutral winds.

  13. Case study of simultaneous observations of sporadic sodium layer, E-region field-aligned irregularities and sporadic E layer at low latitude of China

    Science.gov (United States)

    Xie, H. Y.; Ning, B. Q.; Zhao, X. K.; Hu, L. H.

    2017-03-01

    Using the Na lidar at Haikou (20.0°N, 110.3°E), the VHF coherent radar and the digital ionosonde both at Sanya (18.4°N, 109.6°E), cases of simultaneous observations of sporadic sodium layer (SSL), E-region field-aligned irregularities (FAI) and sporadic E layer (Es) in the mesosphere and lower thermosphere (MLT) region at low latitude of China are studied. It is found that SSL occurs simultaneously or follows the enhancement of Es and FAI. The Es, FAI and SSL descend slowly with time which is mostly controlled by the diurnal tide (DT). Besides, the interaction of gravity wave (GW) with tides can cause oscillations in FAI and SSL. Our observations support the neutralization of ions for SSL formation: when the metallic ions layer descents to the altitudes where models predict, the sodium ions convert rapidly to atomic Na that may form an SSL event. Moreover, the SSL peak density will increase (decrease) in the convergence (divergence) vertical shear region of zonal wind.

  14. Modulation of Low-Latitude West Wind on Abnormal Track and Intensity of Tropical Cyclone Nargis (2008) in the Bay of Bengal

    Institute of Scientific and Technical Information of China (English)

    LI Wei-Wei; WANG Chunzai; WANG Dongxiao; YANG Lei; DENG Yi

    2012-01-01

    Tropical cyclone (TC) Nargis (2008) made landfall in Myanmar on 02 May 2008,bringing a storm surge,major flooding,and resulting in a significant death toll. TC Nargis (2008) displayed abnormal features,including rare eastward motion in its late stage,rapid intensification before landing.Using reanalysis data and a numerical model,we investigated how a low-latitude westerly wind modulated TC Nargis' (2008) track and provided favorable atmospheric conditions for its rapid intensification.More importantly,we found a possible counterbalance effect of flows from the two hemispheres on the TC track in the Bay of Bengal.Our analysis indicates that a strong westerly wind burst across the Bay of Bengal,resulting in TC Nargis' (2008) eastward movement after its recurvature.This sudden enhancement of westerly wind was mainly due to the rapidly intensified mid-level cross-equatorial flow.Our results show that a high-pressure system in the Southern Hemisphere induced this strong,mid-level,cross-equatorial flow.During the rapid intensification period of TC Nargis (2008),this strong and broad westerly wind also transported a large amount of water vapor to TC Nargis (2008).Sufficient water vapor gave rise to continuously high and increased mid-level relative humidity,which was favorable to TC Nargis' (2008) intensification.Condensation of water vapor increased the energy supply,which eventuated the intensification of TC Nargis (2008) to a category 4 on the Saffir-Simpson scale.

  15. Work Experience of Magnetic Prospecting in Low Latitude Region%低纬度地区磁异常处理方法应用体会

    Institute of Scientific and Technical Information of China (English)

    王洁

    2015-01-01

    在位于磁赤道带两侧的低磁纬度区内,以水平磁化为主的条件下,地下磁性体所产生的△T 异常特征与处于中高纬度地区的△T 异常特征会有较大差别,把低纬度地区的磁法测量数据转换成中高纬度地区的,然后对磁异常进行处理解释,经过矿区勘探对比,效果良好。%The ground magnetic body generates △T anomalies is different from △T anomalies in middle latitude region mainly at the level of magnetization condition and located on both sides of the magnetic equator with low magnetic latitude area.The paper proposes the conversion method for processing and interpretation of magnetic anomalies about magnetic survey data from low latitude region into high latitude region.The effect is better according to comparison of the mining exploration.

  16. Spread-F during the magnetic storm of 22 January 2004 at low latitudes: Effect of IMF-Bz in relation to local sunset time

    Indian Academy of Sciences (India)

    R G Rastogi; H Chandra; P Janardhan; Thai Lan Hoang; Louis Condori; T K Pant; D S V V D Prasad; B Reinisc

    2014-08-01

    The paper describes the results of spread-F at low latitude stations around the world during the magnetic storm starting at 0130 UT on 22 January 2004. The storm can be divided into two phases, first phase up to 1000 UT when interplanetary magnetic field IMF-Bz was highly fluctuating around a small positive value and the second phase after a sudden large southward turning of IMF-Bz at 1030 UT. The first phase produced strong spread-F at Jicamarca, Sao Luis, and Ascension Island and caused complete inhibition of spread-F at Thumba and Waltair in India. It generated weak spread-F at Ho Chi Minh City in Vietnam and strong spread-F at Hainan and Chung Li. The strong spread-F at Hainan and Chung Li were caused by the positive IMF-Bz during the first phase of the storm and not by the negative pulse of IMF-Bz at 1000 UT.

  17. Difficulties in the study of cosmic radio noise absorption at 30 MHz using riometer at low latitude station, Kolhapur (Lat-16.8°N, Long-74.25°E)

    Science.gov (United States)

    Nikte, S. S.; Sharma, A. K.; Nade, D. P.; Rokade, M. V.; Ghodpage, R. N.; Patil, P. T.; Bhonsle, R. V.

    2014-01-01

    A dual dipole antenna has been installed at low latitude station Kolhapur (Geographic 16.8°N, 74.25°E), Maharashtra, India for the study of cosmic radio noise absorption using Solid State Riometer (which operates at 30 MHz) during pre phase of 24th solar maxima. The aim for this type of study over Kolhapur was to know the response of lower (D region) ionosphere over low latitude by cosmic radio noise absorption using riometer technique during quite period as well as sudden ionospheric disturbances (SID). The observations are being taken for 3 years. Two different sites (˜40 km away from each other) were used for the installation of riometer equipment assuming minimum local noise. It is found that solar noise to cosmic radio noise hence resulting in signal saturation. The night time signal is relatively free of interference but sometimes local noise is responsible for spike-like signatures. Hence it is concluded that Kolhapur (a low latitude station) is not suitable for the study of cosmic radio noise absorption on 30 MHz with riometer and dual dipole antenna. Proper choice for operating frequency of riometer and antenna gain is suggested for low latitude use of this technique for ionospheric deviative and nondeviative absorption studies.

  18. Rayleigh LiDAR investigation of stratospheric sudden warming over a low latitude station, Gadanki (13.5ºN; 79.2ºE) – a statistical study

    CSIR Research Space (South Africa)

    Charyulu, DV

    2007-08-01

    Full Text Available In this paper, the authors report the statistical characteristics of Stratospheric Sudden Warming (SSW) events observed over a low latitude station, Gadanki; 13.5°N, 79.2°E. The study uses 7 years (1998 to 2004) of quasi-continuous nighttime Li...

  19. Response of low latitude D-region ionosphere to the Total Solar Eclipse of 22 July 2009, deduced from ELF/VLF analysis

    Science.gov (United States)

    Singh, A. K.; Singh, R.; Singh, A. K.

    2011-12-01

    Response of the D-region of the ionosphere to the total solar eclipse of 22 July 2009 at low latitude, Varanasi (geomagnetic lat = 140 55'N, longitude = 1540 E, dip. angle = 37.30) was investigated using ELF/VLF radio signal. The solar eclipse started at 05:30:04.4 hrs IST and lasted up to 07:27 hrs IST with totally from 6.25 IST to 6.27 IST.The changes in D-region ionospheric VLF reflection heights and electron density during eclipse have been estimated from tweek analysis. The reflection height increased from ~90 km from the first occurrence of tweek to about 93-94 km at the totality and then decreased to ~89 km at the end of the eclipse. The reflection heights are lower by 2-3 km as compared to the usual nighttime tweek reflection heights. The electron density is found to vary between 25-27 cm-3 at the reflection heights. The significant increase in tweek reflection height of about 15 km during the eclipse as compared to the daytime (morning) reflection heights of ~ 78 km is observed. Observations suggest that about 30-40% obscuration of solar disc can lead to the tweeks occurrence which otherwise occur only in the nighttime. A significant increase of 3dB in the strength of the amplitude of VLF signal is observed around the time of TSE as compared to a control day. These low latitude ionospheric perturbations on the eclipse day are discussed and compared with other normal days. During a solar eclipse, the decrease in solar flux due to moon's shadow causes sudden change in the D-region physical and chemical processes. During the totality due to blocking of Lyman-α 1215Å (major D-region ionizing radiation) by moon's umbral shadow, the electron density decreases drastically towards the nighttime values [Smith, 1972]. During the TSE, there was no production of ionization in the ionosphere and the ions and electrons in the lowest part of it recombined at a rapid rate resulting a depletion in the electron density in the 'D' region of the Ionosphere and hence an

  20. VHF and L-band scintillation characteristics over an Indian low latitude station, Waltair (17.7° N, 83.3° E

    Directory of Open Access Journals (Sweden)

    P. V. S. Rama Rao

    2005-10-01

    Full Text Available Characteristics of simultaneous VHF (244 MHz and L-band (1.5 GHz scintillations recorded at a low-latitude station, Waltair (17.7° N, 83.3° E, during the low sunspot activity year of March 2004 to March 2005, suggest that the occurrence of scintillations is mainly due to two types, namely the Plasma Bubble Induced (PBI, which maximizes during the post sunset hours of winter and equinoctial months, and the Bottom Side Sinusoidal (BSS type, which maximizes during the post-midnight hours of the summer solstice months. A detailed study on the spectral characteristics of the scintillations at both the frequencies show that the post-sunset scintillations are strong with fast fading (≈40 fad/min and are multiple in nature in scattering, giving rise to steep spectral slopes, whereas the post-midnight scintillations, which occur mostly on the VHF signal with low fading rate (≈4 fad/min, are of the BSS type, often showing typical Fresnel oscillations with reduced roll off spectral slopes, indicating that the type of irregularity resembles a thin screen structure giving rise to weak scattering. Using the onset times of several similar scintillation patches across the two satellite (FLEETSAT 73° E, INMARSAT 65° E ray paths (sub-ionospheric points are separated by 82 km, the East ward movement of the irregularity patches is found to vary from 150 to 250 m/s during the post sunset hours and decrease slowly during the post midnight hours. Further, the east-west extent of the PBI type of irregularities is found to vary from 100 to 500 km, while that of the BSS type extend up to a few thousand kilometers.

    Keywords. Ionosphere (Ionospheric irregularities; Auroral ionosphere; Electric fields and currents

  1. A comparison of benthic foraminiferal Mn / Ca and sedimentary Mn / Al as proxies of relative bottom-water oxygenation in the low-latitude NE Atlantic upwelling system

    Science.gov (United States)

    McKay, C. L.; Groeneveld, J.; Filipsson, H. L.; Gallego-Torres, D.; Whitehouse, M. J.; Toyofuku, T.; Romero, O. E.

    2015-09-01

    Trace element incorporation into foraminiferal shells (tests) is governed by physical and chemical conditions of the surrounding marine environment, and therefore foraminiferal geochemistry provides a means of palaeo-oceanographic reconstructions. With the availability of high-spatial-resolution instrumentation with high precision, foraminiferal geochemistry has become a major research topic over recent years. However, reconstructions of past bottom-water oxygenation using foraminiferal tests remain in their infancy. In this study we explore the potential of using Mn / Ca determined by secondary ion mass spectrometry (SIMS) as well as by flow-through inductively coupled plasma optical emission spectroscopy (FT-ICP-OES) in the benthic foraminiferal species Eubuliminella exilis as a proxy for recording changes in bottom-water oxygen conditions in the low-latitude NE Atlantic upwelling system. Furthermore, we compare the SIMS and FT-ICP-OES results with published Mn sediment bulk measurements from the same sediment core. This is the first time that benthic foraminiferal Mn / Ca is directly compared with Mn bulk measurements, which largely agree on the former oxygen conditions. Samples were selected to include different productivity regimes related to Marine Isotope Stage 3 (35-28 ka), the Last Glacial Maximum (28-19 ka), Heinrich Event 1 (18-15.5 ka), Bølling Allerød (15.5-13.5 ka) and the Younger Dryas (13.5-11.5 ka). Foraminiferal Mn / Ca determined by SIMS and FT-ICP-OES is comparable. Mn / Ca was higher during periods with high primary productivity, such as during the Younger Dryas, which indicates low-oxygen conditions. This is further supported by the benthic foraminiferal faunal composition. Our results highlight the proxy potential of Mn / Ca in benthic foraminifera from upwelling systems for reconstructing past variations in oxygen conditions of the sea floor environment as well as the need to use it in combination with other proxy records such as faunal

  2. Accounting for observation uncertainties in an evaluation metric of low latitude turbulent air-sea fluxes: application to the comparison of a suite of IPSL model versions

    Science.gov (United States)

    Servonnat, Jérôme; Găinuşă-Bogdan, Alina; Braconnot, Pascale

    2017-09-01

    Turbulent momentum and heat (sensible heat and latent heat) fluxes at the air-sea interface are key components of the whole energetic of the Earth's climate. The evaluation of these fluxes in the climate models is still difficult because of the large uncertainties associated with the reference products. In this paper we present an objective metric accounting for reference uncertainties to evaluate the annual cycle of the low latitude turbulent fluxes of a suite of IPSL climate models. This metric consists in a Hotelling T 2 test between the simulated and observed field in a reduce space characterized by the dominant modes of variability that are common to both the model and the reference, taking into account the observational uncertainty. The test is thus more severe when uncertainties are small as it is the case for sea surface temperature (SST). The results of the test show that for almost all variables and all model versions the model-reference differences are not zero. It is not possible to distinguish between model versions for sensible heat and meridional wind stress, certainly due to the large observational uncertainties. All model versions share similar biases for the different variables. There is no improvement between the reference versions of the IPSL model used for CMIP3 and CMIP5. The test also reveals that the higher horizontal resolution fails to improve the representation of the turbulent surface fluxes compared to the other versions. The representation of the fluxes is further degraded in a version with improved atmospheric physics with an amplification of some of the biases in the Indian Ocean and in the intertropical convergence zone. The ranking of the model versions for the turbulent fluxes is not correlated with the ranking found for SST. This highlights that despite the fact that SST gradients are important for the large-scale atmospheric circulation patterns, other factors such as wind speed, and air-sea temperature contrast play an

  3. Accounting for observation uncertainties in an evaluation metric of low latitude turbulent air-sea fluxes: application to the comparison of a suite of IPSL model versions

    Science.gov (United States)

    Servonnat, Jérôme; Găinuşă-Bogdan, Alina; Braconnot, Pascale

    2016-11-01

    Turbulent momentum and heat (sensible heat and latent heat) fluxes at the air-sea interface are key components of the whole energetic of the Earth's climate. The evaluation of these fluxes in the climate models is still difficult because of the large uncertainties associated with the reference products. In this paper we present an objective metric accounting for reference uncertainties to evaluate the annual cycle of the low latitude turbulent fluxes of a suite of IPSL climate models. This metric consists in a Hotelling T 2 test between the simulated and observed field in a reduce space characterized by the dominant modes of variability that are common to both the model and the reference, taking into account the observational uncertainty. The test is thus more severe when uncertainties are small as it is the case for sea surface temperature (SST). The results of the test show that for almost all variables and all model versions the model-reference differences are not zero. It is not possible to distinguish between model versions for sensible heat and meridional wind stress, certainly due to the large observational uncertainties. All model versions share similar biases for the different variables. There is no improvement between the reference versions of the IPSL model used for CMIP3 and CMIP5. The test also reveals that the higher horizontal resolution fails to improve the representation of the turbulent surface fluxes compared to the other versions. The representation of the fluxes is further degraded in a version with improved atmospheric physics with an amplification of some of the biases in the Indian Ocean and in the intertropical convergence zone. The ranking of the model versions for the turbulent fluxes is not correlated with the ranking found for SST. This highlights that despite the fact that SST gradients are important for the large-scale atmospheric circulation patterns, other factors such as wind speed, and air-sea temperature contrast play an

  4. Low-latitude ionosphere response to super geomagnetic storm of 17/18 March 2015: Results from a chain of ground-based observations over Indian sector

    Science.gov (United States)

    Ramsingh; Sripathi, S.; Sreekumar, Sreeba; Banola, S.; Emperumal, K.; Tiwari, P.; Kumar, Burudu Suneel

    2015-12-01

    In this paper, we present unique results of equatorial and low-latitude ionosphere response to one of the major geomagnetic storms of the current solar cycle that occurred during 17-18 March 2015, where Dst reached its minimum of -228 nT. Here we utilized data from magnetometers, chain of ionosondes located at Tirunelveli (8.73°N, 77.70°E; geometry: 0.32°N), Hyderabad (17.36°N, 78.47°E; geometry 8.76°N), and Allahabad (25.45°N, 81.85°E; geometry 16.5°N) along with multistation GPS receivers over Indian sector. The observations showed a remarkable increase of h'F to as high as ~560 km over Tirunelveli (magnetic equator) with vertical drift of ~70 m/s at 13:30 UT due to direct penetration of storm time eastward electric fields which exactly coincided with the local time of pre-reversal enhancement (PRE) and caused intense equatorial spread F irregularities in ionosondes and scintillations in GPS receivers at wide latitudes. Plasma irregularities are so intense that their signatures are seen in Allahabad/Lucknow. Storm time thermospheric meridional winds as estimated using two ionosondes suggest the equatorward surge of gravity waves with period of ~2 h. Suppression of anomaly crest on the subsequent day of the storm suggests the complex role of disturbance dynamo electric fields and disturbance wind effects. Our results also show an interesting feature of traveling ionospheric disturbances possibly associated with disturbance meridional wind surge during recovery phase. In addition, noteworthy observations are nighttime westward zonal drifts and PRE-related total electron content enhancements at anomaly crests during main phase and counter electrojet signatures during recovery phase.

  5. Response of equatorial and low latitude ionosphere to 2015 St. Patrick's Day super geomagnetic storm: Results from a chain of ground based observations over Indian region

    Science.gov (United States)

    Samireddipalle, Sripathi; Singh, Ram; Sreekumar, Sreeba; Suneel Kumar, Buduru

    2016-07-01

    In this paper, we present unique results of equatorial and low latitude ionosphere response to one of the major geomagnetic storms of the current solar cycle that occurred during 17-18 March 2015 where Dst reached its minimum of -228 nT. Here we utilized data from magnetometers, chain of ionosondes located at Tirunelveli (8.73°N, 77.70°E; geom: 0.320N), Hyderabad (17.360N, 78.470E; geom: 8.760N) and Allahabad (25.45°N, 81.85°E; geom: 16.50N) along with multi station GPS receivers over Indian sector. The observations showed a remarkable increase of h'F to as high as ~560 km over Tirunelveli (magnetic equator) with vertical drift of ~70 m/s at 13:30 UT due to direct penetration of storm time eastward electric fields which exactly coincided with the local time of Pre-Reversal Enhancement (PRE) and caused intense ESF irregularities in ionosondes and scintillations in GPS receivers at wide latitudes. Plasma irregularities are so intense that their signatures are seen in Allahabad/Lucknow. Stormtime thermospheric meridional winds as estimated using two ionosondes suggest the equatorward surge of gravity waves with period of ~2 hrs. Suppression of anomaly crest on the subsequent day of the storm suggests the complex role of disturbance dynamo electric fields and disturbance wind effects. Our results also show an interesting feature of Traveling Ionospheric Disturbances (TIDs) possibly associated with disturbance meridional wind surge during recovery phase. In addition, noteworthy observations are nighttime westward zonal drifts and PRE related TEC enhancements at anomaly crests during main phase and CEJ signatures during recovery phase.

  6. Structural Analysis Of Alfa Fibers After Chemical Treatment

    Directory of Open Access Journals (Sweden)

    Zakaria Mouallif

    2015-02-01

    Full Text Available Nowadays, natural fibers are used as reinforcement in composite materials. The Alfa fibers have undergone an alkaline treatment with sodium hydroxide NaOH at a concentration of 10%, during an immersion period of two days. After drying, the Fourier transform infrared spectroscopy by attenuated total reflection (FTIR-ATR and X-ray diffraction (XRD were used for the analysis of the chemical properties of these fibers which were extracted from the plant Alfa of the region Al Haouz (Morocco in order to study the modifications resulting from the alkaline treatment. The results proved the presence of the cellulose, with an increase in its proportion in those fibers which have undergone an alkaline treatment with NaOH, the presence of lignin and pectin, as well as their disappearance after the alkaline extraction.

  7. Pathophysiology of hypophosphatasia and the potential role of asfotase alfa

    Directory of Open Access Journals (Sweden)

    Orimo H

    2016-05-01

    Full Text Available Hideo Orimo Division of Metabolism and Nutrition, Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan Abstract: Hypophosphatasia (HPP is an inherited systemic bone disease that is characterized by bone hypomineralization. HPP is classified into six forms according to the age of onset and severity as perinatal (lethal, perinatal benign, infantile, childhood, adult, and odontohypophosphatasia. The causative gene of the disease is the ALPL gene that encodes tissue-nonspecific alkaline phosphatase (TNAP. TNAP is expressed ubiquitously, and its physiological role is apparent in bone mineralization. A defect in bone mineralization can manifest in several ways, including rickets or osteomalacia in HPP patients. Patients with severe forms suffer from respiratory failure because of hypoplastic chest, which is the main cause of death. They sometimes present with seizures due to a defect in vitamin B6 metabolism resulting from the lack of alkaline phosphatase activity in neuronal cells, which is also lethal. Patients with a mild form of the disease exhibit rickets or osteomalacia and a functional defect of exercise. Odontohypophosphatasia shows only dental manifestations. To date, 302 mutations in the ALPL gene have been reported, mainly single-nucleotide substitutions, and the relationships between phenotype and genotype have been partially elucidated. An established treatment for HPP was not available until the recent development of enzyme replacement therapy. The first successful enzyme replacement therapy in model mice using a modified human TNAP protein (asfotase alfa was reported in 2008, and subsequently success in patients with severe form of the disease was reported in 2012. In 2015, asfotase alfa was approved in Japan in July, followed by in the EU and Canada in August, and then by the US Food and Drug Administration in the USA in October. It is expected that therapy with asfotase alfa will drastically change

  8. Physics prospects with the ALFA and AFP detectors

    CERN Document Server

    Hamal, P; The ATLAS collaboration

    2013-01-01

    We will describe the experimental challenge presented by the measurement of the forward protons at the LHC. The ATLAS ALFA and AFP projects involve the deployment of detectors capable of detecting protons that emerge intact from the interaction with very small scattering angles. In the case of the ALFA detector, located at $\\pm${240}~m from the ATLAS interaction point, this measurement has to be performed using special high $\\beta^*$ beam optics. The detector chosen for the task is a nearly edgeless scintillating fibre tracker capable of making measurements at very low $t$ - below $10^{-3} \\text{GeV}^2$ - in the Nuclear Coulomb interference region. In order to reach these very small $t$ values we need to deploy the detector very near to the beam line utilizing Roman Pots. The main purpose of the ALFA detector is to measure the total p-p cross-section, a fundamental quantity in hadronic physics of importance to particle and to cosmic ray physicists and to provide absolute measurement of luminosity which includ...

  9. Upgrade of ATLAS-ALFA for Run2

    CERN Document Server

    Jakobsen, Sune; The ATLAS collaboration

    2016-01-01

    Early experience with the operation of the ALFA detectors in the LHC environment has shown significant beam-induced heating. Comprehensive studies on the effects of heating with a spare detector module have furthermore revealed that heating effects could be disastrous in the case of the larger beam intensities foreseen for higher luminosity. A temporary solution was implemented and kept the detectors below the critical temperature in 2012. In LS1 all ALFA stations have been removed from LHC and are undergoing an upgrade of the geometry of Roman Pots to minimize the impedance losses. When the stations were re-installed ~4 m distance was added between them to gain level arm in the angular measurement between the stations. The updated geometry of the Roman Pot, together with a system to improve the internal heat transfer and an air cooling system, is expected to keep the temperatures of ALFA detectors below critical limits throughout the LHC Run2 and first results from the performance in 2016 will be presented. ...

  10. Characterisation of GPS-TEC in the African equatorial and low latitude region and the regional evaluation of the IRI model

    Science.gov (United States)

    Adebiyi, S. J.; Adimula, I. A.; Oladipo, O. A.

    2016-06-01

    With the increasing application of Global Navigation Satellite System (GNSS) products and services, knowledge of the Total Electron Content (TEC) variation is vital, particularly in historically under-sampled regions. The ionospheric induced-error, which is the largest and most variable error source of GNSS applications, is proportional to TEC along the satellite-receiver path. Simultaneous Global Positioning System (GPS) measurements from six African equatorial and low latitude stations in the southern hemisphere are used to investigate the latitudinal variation of TEC over the region during the year 2013, a year of moderate solar activity. The analysis reveals some detailed features of seasonal, month-to-month and solar activity dependence of TEC. The seasonal variation of TEC revealed that the daytime and the pre-midnight values of TEC for stations located close to the geographic equator is considerably higher in equinoxes and June solstice compared to stations farther from the equator, however, the difference is insignificant during the December solstice. The month-to-month variation of TEC shows semi-annual symmetry/asymmetry in TEC values for stations closer/farther from the equator. TEC sensitivity to solar activity shows significant seasonal and latitudinal characteristics. Generally, a relatively good correlation exists between TEC and F10.7 for stations around the Equatorial Ionization Anomaly (EIA) region compared to those found at stations close to the equator. Beyond the EIA region, the correlation coefficients drop in all seasons. TEC predicted by the three topside options of the International Reference Ionosphere (IRI) 2012 model [i.e. the NeQuick (NeQ), IRI-2001 Corrected (IRI-01 Corr) and the IRI-2001 (IRI-01) options] exhibits latitudinal and seasonal characteristics. The NeQ option performed better than the other two options at stations located within the equatorial region in most of the months and seasons. Outside the EIA region, the IRI-01 Corr

  11. Accounting for observational uncertainties in the evaluation of low latitude turbulent air-sea fluxes simulated in a suite of IPSL model versions

    Science.gov (United States)

    Servonnat, Jerome; Braconnot, Pascale; Gainusa-Bogdan, Alina

    2015-04-01

    Turbulent momentum and heat (sensible and latent) fluxes at the air-sea interface are key components of the whole energetic of the Earth's climate and their good representation in climate models is of prime importance. In this work, we use the methodology developed by Braconnot & Frankignoul (1993) to perform a Hotelling T2 test on spatio-temporal fields (annual cycles). This statistic provides a quantitative measure accounting for an estimate of the observational uncertainty for the evaluation of low-latitude turbulent air-sea fluxes in a suite of IPSL model versions. The spread within the observational ensemble of turbulent flux data products assembled by Gainusa-Bogdan et al (submitted) is used as an estimate of the observational uncertainty for the different turbulent fluxes. The methodology holds on a selection of a small number of dominating variability patterns (EOFs) that are common to both the model and the observations for the comparison. Consequently it focuses on the large-scale variability patterns and avoids the possibly noisy smaller scales. The results show that different versions of the IPSL couple model share common large scale model biases, but also that there the skill on sea surface temperature is not necessarily directly related to the skill in the representation of the different turbulent fluxes. Despite the large error bars on the observations the test clearly distinguish the different merits of the different model version. The analyses of the common EOF patterns and related time series provide guidance on the major differences with the observations. This work is a first attempt to use such statistic on the evaluation of the spatio-temporal variability of the turbulent fluxes, accounting for an observational uncertainty, and represents an efficient tool for systematic evaluation of simulated air-seafluxes, considering both the fluxes and the related atmospheric variables. References Braconnot, P., and C. Frankignoul (1993), Testing Model

  12. Changes in opal fluxes along the northwest African margin during the last glacial period; linking high and low latitude patterns of productivity

    Science.gov (United States)

    Bradtmiller, L. I.; Galgay, M.; McGee, D.; Kinsley, C. W.; Anderson, R. F.

    2014-12-01

    Recent studies have proposed competing hypotheses to explain increased opal fluxes in high and low latitudes during the most recent deglaciation. Anderson et al. (2009) rely on increased wind-driven upwelling in the Southern Ocean to explain the increased availability of Si in both the Southern Ocean and tropical thermoclines, leading to increased opal fluxes in both regions coincident with the deglacial rise in CO2. Meckler et al. (2013) suggest that a decrease in the presence of North Atlantic intermediate water (GNAIW) during the deglaciation allowed Si-rich southern-sourced waters to fill the tropical Atlantic leading to increased opal burial. We attempt to distinguish between these two mechanisms by reconstructing opal fluxes and fluxes of windblown dust over the past ~65ka at four sites along the northwest African margin. The records include the deglaciation, including Heinrich Event 1 (H1) and the Younger Dryas (YD), as well as several earlier Heinrich events. We find that opal and dust fluxes increase simultaneously during the deglaciation, and more highly resolved cores record H1 and the YD as distinct peaks within the deglaciation. Furthermore, opal and dust fluxes scale approximately linearly with one another during these events. We observe opal peaks associated with most Heinrich Events through H6. Finally, we observe a strong similarity between patterns of opal flux in the Southern Ocean and along the African Margin. This suggests that the pattern of diatom productivity and opal flux along the African Margin reflects a combination of changes in wind strength due to shifting temperature gradients, and changes in the export of silica-rich water from the Southern Ocean, both as a result of the global scale climate changes associated with Heinrich Events. Anderson, R. F., S. Ali, L. I. Bradtmiller, S. H. H. Nielsen, M. Q. Fleisher, B. E. Anderson and L. H. Burckle. Wind-Driven Upwelling in the Southern Ocean and the Deglacial Rise in Atmospheric CO2

  13. Pathophysiology of hypophosphatasia and the potential role of asfotase alfa

    Science.gov (United States)

    Orimo, Hideo

    2016-01-01

    Hypophosphatasia (HPP) is an inherited systemic bone disease that is characterized by bone hypomineralization. HPP is classified into six forms according to the age of onset and severity as perinatal (lethal), perinatal benign, infantile, childhood, adult, and odontohypophosphatasia. The causative gene of the disease is the ALPL gene that encodes tissue-nonspecific alkaline phosphatase (TNAP). TNAP is expressed ubiquitously, and its physiological role is apparent in bone mineralization. A defect in bone mineralization can manifest in several ways, including rickets or osteomalacia in HPP patients. Patients with severe forms suffer from respiratory failure because of hypoplastic chest, which is the main cause of death. They sometimes present with seizures due to a defect in vitamin B6 metabolism resulting from the lack of alkaline phosphatase activity in neuronal cells, which is also lethal. Patients with a mild form of the disease exhibit rickets or osteomalacia and a functional defect of exercise. Odontohypophosphatasia shows only dental manifestations. To date, 302 mutations in the ALPL gene have been reported, mainly single-nucleotide substitutions, and the relationships between phenotype and genotype have been partially elucidated. An established treatment for HPP was not available until the recent development of enzyme replacement therapy. The first successful enzyme replacement therapy in model mice using a modified human TNAP protein (asfotase alfa) was reported in 2008, and subsequently success in patients with severe form of the disease was reported in 2012. In 2015, asfotase alfa was approved in Japan in July, followed by in the EU and Canada in August, and then by the US Food and Drug Administration in the USA in October. It is expected that therapy with asfotase alfa will drastically change treatments and prognosis of HPP. PMID:27274262

  14. Reconocimiento de expresiones faciales empleando memorias asociativas Alfa-Beta

    OpenAIRE

    Márquez Olivera, Moisés Vicente

    2016-01-01

    El presente trabajo de tesis orienta su atención en la compleja tarea del reconocimiento automático de las expresiones faciales, el propósito principal es probar la asertividad y competitividad de las memorias asociativas de tipo Alfa-Beta en el reconocimiento automático de expresiones faciales. La primera parte de la tesis brinda una breve introducción, la cual enfatiza la importancia de las expresiones faciales en la comunicación humana, incluyendo los estudios más relevantes dedicados a...

  15. Desarrollo de un sitio web para el proyecto Alfa Gaviota

    OpenAIRE

    Trelles Labairu, Hilton

    2013-01-01

    Este proyecto muestra todos los pasos a seguir para recolectar, organizar, tratar y construir un portal web para el grupo de universidades partícipes en el proyecto Alfa Gaviota III utilizando un sistema gestor de contenidos. Se parte de una base de información recopilada en unas cuántas páginas html realizadas con la tecnología de google docs. Es un requisito indispensable conseguir una forma de almacenar toda la información del proyecto consumiendo el mínimo espacio y recurso...

  16. ALFA detector, Background removal and analysis for elastic events

    CERN Document Server

    Belaloui, Nazim

    2017-01-01

    I worked on the ALFA project, which has the aim to measure the total cross section in PP collisions as a function of t, the momentum transfer by measuring the scattering angle of the protons. This measurement is done for all available energies; so far 7, 8 and 13 TeV. There are many analysis steps and we have focused on enhancing the signal-to-noise ratio. First of all I tried to be more familiar with ROOT, worked on understanding the code used to access to the data, plotting histograms, then cutting-off background.

  17. Peginterferon alfa-2a for AIDS-associated Kaposi sarcoma: experience with 10 patients.

    Science.gov (United States)

    Rokx, Casper; van der Ende, Marchina E; Verbon, Annelies; Rijnders, Bart J A

    2013-11-01

    In this observational cohort study, 10 patients with extensive or treatment-refractory AIDS-associated Kaposi sarcoma were treated with peginterferon alfa-2a. Tumor responses were observed in 9 patients with a median progression-free survival of 645 days. Peginterferon alfa-2a could be an effective therapy for extensive or treatment-resistant Kaposi sarcoma.

  18. 意大利精灵——Alfa Romeo MITO

    Institute of Scientific and Technical Information of China (English)

    柳柽

    2008-01-01

    Alfa Romeo 是一个对激情执着的品牌,即便是对于MITO这样一部掀背小车也不例外,这部意大利制造的Alfa Romeo MITO上,会让你感受到一种热辣奔放的别样风情。

  19. Statistical study of the location and size of the electron edge of the Low-Latitude Boundary Layer as observed by Cluster at mid-altitudes

    Directory of Open Access Journals (Sweden)

    Y. V. Bogdanova

    2006-10-01

    Full Text Available The nature of particle precipitations at dayside mid-altitudes can be interpreted in terms of the evolution of reconnected field lines. Due to the difference between electron and ion parallel velocities, two distinct boundary layers should be observed at mid-altitudes between the boundary between open and closed field lines and the injections in the cusp proper. At lowest latitudes, the electron-dominated boundary layer, named the "electron edge" of the Low-Latitude Boundary Layer (LLBL, contains soft-magnetosheath electrons but only high-energy ions of plasma sheet origin. A second layer, the LLBL proper, is a mixture of both ions and electrons with characteristic magnetosheath energies. The Cluster spacecraft frequently observe these two boundary layers. We present an illustrative example of a Cluster mid-altitude cusp crossing with an extended electron edge of the LLBL. This electron edge contains 10–200 eV, low-density, isotropic electrons, presumably originating from the solar wind halo population. These are occasionally observed with bursts of parallel and/or anti-parallel-directed electron beams with higher fluxes, which are possibly accelerated near the magnetopause X-line. We then use 3 years of data from mid-altitude cusp crossings (327 events to carry out a statistical study of the location and size of the electron edge of the LLBL. We find that the equatorward boundary of the LLBL electron edge is observed at 10:00–17:00 magnetic local time (MLT and is located typically between 68° and 80° invariant latitude (ILAT. The location of the electron edge shows a weak, but significant, dependence on some of the external parameters (solar wind pressure, and IMF BZ- component, in agreement with expectations from previous studies of the cusp location. The latitudinal extent of the electron edge has been estimated using new multi-spacecraft techniques. The Cluster tetrahedron crosses the electron and ion boundaries of

  20. The Arecibo Legacy Fast ALFA (ALFALFA) Extragalactic HI Survey

    CERN Document Server

    Haynes, Martha P

    2008-01-01

    The Arecibo Legacy Fast ALFA (ALFALFA) survey is a program aimed at obtaining a census of HI-bearing objects over a cosmologically significant volume of the local universe. When complete in ~3-4 years, it will cover 7000 square degrees of high latitude sky using the 305m telescope and the seven-beam Arecibo L-band feed array (ALFA). As of May 1, 2008, almost 60% of the required observations are complete and a catalog exists in preliminary form for 25% of the final sky area. ALFALFA is detecting about twice as many HI sources as predicted based on previously published HI mass functions and should deliver a final catalog of >25000 extragalactic HI sources. ALFALFA will detect hundreds of galaxies with HI masses less than 10**7.5 solar masses and similarly large numbers greater than 10**10.3 Msun. Its centroiding accuracy allows for the immediate identification of highly probably optical counterparts to each HI detection. Fewer than 3% of all extragalactic HI sources, and 10**9.5 Msun cannot be identified with ...

  1. Stock footage ATLAS-ALFA experiment November 2016

    CERN Multimedia

    2016-01-01

    This footage shows an ALFA station of the ATLAS experiment in the LHC tunnel. This detector aims to measure the elastic proton scattering and to determine from these data the elastic and total cross sections, as well as the luminosity. Altogether there are two times two stations at both sides of ATLAS at Point 1 in a distance of about 240m. Each station consist of two Roman Pots which are equipped with scintillating fiber detectors. They are used under special beam conditions (high beta*) when the detectors are moved close to the circulating LHC beams (as close as 1mm). In standard high intensity LHC runs the Pots remain in parking position. The movie records the composition of an ALFA station at the C-side of ATLAS in the tunnel section *** 7L1. All stations are placed on the outgoing beams where scattered protons are expected. That's why the station mechanics is partly covered by the tubes of incoming beam lines. The stations are placed in between the large boxes with DQR resistors to absorb the magnet curr...

  2. Therapeutic efficacy of a biosimilar epoetin alfa in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Amel Harzallah

    2015-01-01

    Full Text Available Anemia is a frequent complication in patients with chronic kidney disease. However, human recombinant erythropoietin (rHu-EPO has revolutionized the management of anemia in chronically dialyzed patients. Epomax ® is a new rHu-EPO alfa manufactured in Tunisia (Medis Laboratories. The aim of this study was to evaluate the efficacy and tolerance of Epomax ® in chronic hemodialysis (HD patients in a phase-III, multicenter, clinical trial. Fiftythree HD patients (mean age 47.7 ± 13 years who received a stable dose of rHu-EPO (Hemax ® , a rHu-EPO alfa manufactured by Biosidus Laboratories subcutaneously were switched to Epomax ® via the same route of administration. At baseline, the mean systolic pressure was 132 ± 18 mm Hg and the mean diastolic pressure was 79 ± 8 mm Hg. The mean blood hemoglobin was 10.2 g/dL and the median ferritin level was 667 ng/mL. After a follow-up of 43 days, the mean blood hemoglobin was 10.5 g/dL under the effect of Epomax ® . There was no significant difference in the mean hemoglobin levels between the treatments with both drugs. Few adverse events were reported during the study. We conclude that Epomax ® was effective at maintaining the hemoglobin levels at target concentrations and was well tolerated in HD patients.

  3. Alternative method for quantification of alfa-amylase activity

    Directory of Open Access Journals (Sweden)

    DF. Farias

    Full Text Available A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 °C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing α-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale α-amylase over a wide range (2.4 to 7,500 U.mL-1 in scientific investigation as well as in teaching laboratory activities.

  4. AFP and ALFA detectors as a momentum spectrometer system - feasibility study

    CERN Document Server

    ABDUL KHALEK, Rabah

    2015-01-01

    We consider a possibility to measure a leading proton momentum using simultaneously the AFP and ALFA detectors. The idea is based on the simple fact that the proton trajectory through the magnetic field between the AFP and ALFA$_{1}$ detectors, depends on the proton's momentum loss $\\xi$. The feasibility of the proton momentum measurement is directly related to the availability of the magnetic fields and their configuration, the overlap between ALFA and AFP detectors and their resolutions as well as energy losses and the multiple scattering effect that could wash away little actions from the magnets on the proton.

  5. Nebulised dornase alfa versus placebo or hypertonic saline in adult critically ill patients

    DEFF Research Database (Denmark)

    Claudius, Casper; Perner, Anders; Møller, Morten Hylander

    2015-01-01

    BACKGROUND: Nebulised dornase alfa is used off-label in critically ill patients. We aimed to assess the benefits and harms of nebulised dornase alfa versus placebo, no prophylaxis, or hypertonic saline on patient-important outcome measures in adult critically ill patients. METHODS: We performed...... a systematic review with meta-analysis and trial sequential analysis (TSA) using the Cochrane Collaboration methodology. Eligible trials were randomised clinical trials comparing nebulised dornase alfa with placebo, no prophylaxis, or hypertonic saline. The predefined outcome measures were all-cause mortality...

  6. Experimental investigation of the mechanical properties of Alfas stone

    Directory of Open Access Journals (Sweden)

    Konstas N. Kaklis

    2017-04-01

    Full Text Available This paper focuses on the experimental investigation of the mechanical properties of the Alfas natural building stone. Two series of uniaxial compression tests and indirect tensile tests (Brazilian tests were performed in order to determine the uniaxial compressive strength and the indirect tensile strength respectively. Different sets of cylindrical specimens and circular discs were prepared by varying their geometry in order to examine the size effect on the respective strength values. Also, the size effect was investigated with respect to the calculated intact rock modulus and Poisson’s ratio. All specimens were prepared by following the ISRM suggested methods and the load was applied using a stiff 1600 kN MTS hydraulic testing machine and a 500 kN load cell. Strain was measured using biaxial 0/90 stacked rosettes appropriately attached on each specimen.

  7. Fast radio burst discovered in the Arecibo pulsar ALFA survey

    Energy Technology Data Exchange (ETDEWEB)

    Spitler, L. G.; Freire, P. C. C.; Lazarus, P.; Lee, K. J. [Max-Planck-Institut für Radioastronomie, D-53121 Bonn (Germany); Cordes, J. M.; Chatterjee, S.; Wharton, R. S.; Brazier, A. [Department of Astronomy and Space Sciences, Cornell University, Ithaca, NY 14853 (United States); Hessels, J. W. T. [ASTRON, Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Lorimer, D. R.; McLaughlin, M. A. [Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506 (United States); Crawford, F. [Department of Physics and Astronomy, Franklin and Marshall College, Lancaster, PA 17604-3003 (United States); Deneva, J. S. [Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (United States); Kaspi, V. M.; Karako-Argaman, C. [Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada); Allen, B. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Bogdanov, S.; Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Jenet, F. A. [Center for Gravitational Wave Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States); Knispel, B., E-mail: lspitler@mpifr-bonn.mpg.de [Leibniz Universität, Hannover, D-30167 Hannover (Germany); and others

    2014-08-01

    Recent work has exploited pulsar survey data to identify temporally isolated, millisecond-duration radio bursts with large dispersion measures (DMs). These bursts have been interpreted as arising from a population of extragalactic sources, in which case they would provide unprecedented opportunities for probing the intergalactic medium; they may also be linked to new source classes. Until now, however, all so-called fast radio bursts (FRBs) have been detected with the Parkes radio telescope and its 13-beam receiver, casting some concern about the astrophysical nature of these signals. Here we present FRB 121102, the first FRB discovery from a geographic location other than Parkes. FRB 121102 was found in the Galactic anti-center region in the 1.4 GHz Pulsar Arecibo L-band Feed Array (ALFA) survey with the Arecibo Observatory with a DM = 557.4 ± 2.0 pc cm{sup –3}, pulse width of 3.0 ± 0.5 ms, and no evidence of interstellar scattering. The observed delay of the signal arrival time with frequency agrees precisely with the expectation of dispersion through an ionized medium. Despite its low Galactic latitude (b = –0.°2), the burst has three times the maximum Galactic DM expected along this particular line of sight, suggesting an extragalactic origin. A peculiar aspect of the signal is an inverted spectrum; we interpret this as a consequence of being detected in a sidelobe of the ALFA receiver. FRB 121102's brightness, duration, and the inferred event rate are all consistent with the properties of the previously detected Parkes bursts.

  8. Psychiatric side effects of pegylated interferon alfa-2b as compared to conventional interferon alfa-2b in patients with chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    Michael R Kraus; Arne Sch(a)fer; Herbert Csef; Michael Scheurlen

    2005-01-01

    AIM: To assess systematically the spectrum and extent of depressive symptoms comparing patient groups receiving peginterferon or conventional interferon.METHODS: Ninety-eight patients with chronic hepatitis C and interferon-based therapy (+ribavirin) were consecutively enrolled in a longitudinal study. Patients were treated with conventional interferon alfa-2b (48/98patients; 5 MIU interferon alfa-2b thrice weekly) or peginterferon alfa-2b (50/98 patients; 80-150 μgpeginterferon alfa-2b) in combination with weight-adapted ribavirin (800-1 200 mg/d). Repeated psychometric testing was performed before, three times during and once after antiviral therapy: Depression was evaluated by the Hospital Anxiety and Depression Scale (HADS), anger/hostility by the Symptom Checklist-90 Items Revised (SCL-90-R).RESULTS: Therapy with pegylated interferon alfa-2bproduces comparable scores for depression (ANOVA:P = 0.875) as compared to conventional interferon.Maximums of depression scores were even higher and cases of clinically relevant depression were frequent during therapy with peginterferon. Scores for anger/hostility were comparable for both therapy subgroups.CONCLUSION: Our findings suggest that the extent and frequency of depressive symptoms in total are not reduced by peginterferon. Monitoring and management of neuropsychiatric toxicity especially depression have to be considered as much as in antiviral therapy with unmodified interferon.

  9. Alfa tahab TeliaSonerat Türgis üle pakkuda / Tõnis Arnover

    Index Scriptorium Estoniae

    Arnover, Tõnis, 1952-

    2005-01-01

    TeliaSoneraga, kellele kuulub 37 protsenti Türgi operaatorfirma Turkcell aktsiatest, konkureerib täiendava 27 protsendise aktsiapaki ostmises Venemaa operaatorfirmaga Alfa Telecom. Lisa: Kaasosanike huvid põrkuvad. Diagramm: Konkurendid Vene MegaFonis

  10. Alfa tahab TeliaSonerat Türgis üle pakkuda / Tõnis Arnover

    Index Scriptorium Estoniae

    Arnover, Tõnis, 1952-

    2005-01-01

    TeliaSoneraga, kellele kuulub 37 protsenti Türgi operaatorfirma Turkcell aktsiatest, konkureerib täiendava 27 protsendise aktsiapaki ostmises Venemaa operaatorfirmaga Alfa Telecom. Lisa: Kaasosanike huvid põrkuvad. Diagramm: Konkurendid Vene MegaFonis

  11. Measurement of the total cross section with ALFA Detector at ATLAS

    CERN Document Server

    Trzebinski, M; The ATLAS collaboration

    2017-01-01

    The main goals of the Absolute Luminosity For ATLAS (ALFA) detector is to provide an absolute luminosity and total cross section measurement. The measurement method used, the detector alignment and the quality of the collected data are discussed.

  12. Investigation of Mechanical Behavior of Alfa and Gamma Nano- Alumina/ Epoxy Composite Made By Vartm

    Directory of Open Access Journals (Sweden)

    P. Ghabezi

    2016-06-01

    Full Text Available In this paper, the mechanical properties (flexural and tensional modulus and strength are investigated by manufacturing Epoxy/Glass Nano-composite samples with different Nano-particle wt% (Nano-Alumina to find optimum conditions. The alpha and Gamma grade of Nano alumina were added to the epoxy system with the weight percentage of 1, 2, 3, 4, 5 and 6. The experimental results show that the maximum flexural stiffness in Alfa and Gamma Nano-alumina composite is related to 6 wt% and 4 wt% samples, respectively. And the highest tensional stiffness in Alfa and Gamma Nano-alumina composite is related to 4 wt% and 5 wt% samples, respectively. Also the highest toughness for Alfa and Gamma Nano-composites is observed for 4 wt% and 3 wt% samples and in the same way Nano-alumina in grade Alfa with 1 wt% and Gamma with 3 wt% have highest failure strain.

  13. Simulation of the ATLAS ALFA detector in comparison with testbeam data

    CERN Document Server

    Pfeiffer, Felix-Fabian; Stenzel, H

    2010-01-01

    ALFA (Absolute Luminosity for ATLAS) is a scintillating fiber detector for the determination of the absolute luminosity. ALFA con- sists of eight Roman Pots, four on each side of ATLAS at a distance of 240 m. Each detector is made of scintillating fibers with quadratic cross section, glued in UV geometry on ten double sided layers. The detectors are mounted in moveable Roman Pots and can approach the LHC beam up to 1.5 mm, to determine the luminosity from the differential t spectrum of elastically scattered protons using the optical theorem. This is done in special LHC calibration runs with large β ∗ , special focusing and low instant luminosity. The results of ALFA are needed for the calibration of ATLAS luminosity monitors like LUCID. This diploma thesis deals with the simulation of ALFA and the most recent testbeam campaign. A special focus is put on the comparison of results from simulation and testbeam.

  14. Factor de necrosis tumoral alfa en una población infanto-juvenil con sobrepeso

    National Research Council Canada - National Science Library

    Teresita del R. Carrizo; Elba I. Díaz; María S. Velarde; María M. Prado; María C. Bazán; Adela V. Abregú

    2013-01-01

    El sobrepeso infantil está asociado a sobrepeso/obesidad en la edad adulta. El tejido adiposo en obesos produce una cantidad incrementada de citoquinas proinflamatorias como el factor de necrosis tumoral alfa (TNF...

  15. Elosulfase Alfa: a review of its use in patients with mucopolysaccharidosis type IVA (Morquio A syndrome).

    Science.gov (United States)

    Lyseng-Williamson, Katherine A

    2014-10-01

    Elosulfase alfa (Vimizim(®)) is a recombinant form of the human lysosomal enzyme N-acetylgalactosamine-6-sulfatase (GALNS) that is lacking in patients with mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome). It is the first, and currently only, disease-specific treatment option for this very rare, progressively degenerative, autosomal-recessive lysosomal storage disorder. Enzyme replacement therapy with elosulfase alfa aims to restore GALNS activity, thereby preventing the accumulation of keratan sulfate (KS) and chondroitin-6-sulfate in lysosomal compartments of cells that results in the clinical manifestations of MPS IVA. In clinical trials in children and adults with MPS IVA, intravenous elosulfase alfa 2 mg/kg/week provided significant and sustained improvements in urinary levels of KS (a pharmacodynamic biomarker for the disease). In the key placebo-controlled, 24-week, phase 3 trial in patients with MPS IVA aged ≥5 years, elosulfase alfa 2 mg/kg/week significantly improved endurance [least squares mean placebo-adjusted change from baseline in 6-min walk test distance 22.5 m (95 % CI 4.0-40.9)]. Infusion-associated reactions, the primary tolerability issue associated with elosulfase alfa, are generally mild to moderate in severity, self-limiting, and manageable. In the absence of a cure, GALNS enzyme replacement therapy with elosulfase alfa is an important achievement in the treatment of MPS IVA.

  16. Combination of "low-dose" ribavirin and interferon alfa-2a therapy followed by interferon alfa-2a monotherapy in chronic HCV-infected non-responders and relapsers after interferon alfa-2a monotherapy

    Institute of Scientific and Technical Information of China (English)

    Perdita Wietzke-Braun; Volker Meier; Felix Braun; Giuliano Ramadori

    2001-01-01

    AIM To report on the efficacy, safety and tolerability of interferon alfa-2a combined with a "low dose" of ribavirin for relapsers and non responders to alpha interferon monotherapy.METHODS Thirty-four chronic hepatitis C virus-infected non-responders to interferon alfa2a monotherapy (a course of at least 3 months treatment) and 13 relapsers to interferon alfa 2a monotherapy (a dose of 3 to 6 million units three times per week for at least 20 weeks but not more than 18 months) were treated with the same dose of interferon alfa-2a used before (3 to 6 million units three times per week) and ribavirin (10 mg/ kg daily) for 6 months. In complete responders, interferon alfa-2a was administered for further 6 months at the same dose used before as monotherapy.RESULTS Seven (20.6%) of 34 non-responders stopped the combined therapy due to adverse events, including two patients with histological and clinical Child A cirrhosis. In 17/27 (63%)non-responders, the combined therapy was stopped after three months because of non-response. Ten of the 27 non-responders completed the 1;2-month treatment course. At a mean follow up of 28 months (16- 37 months)after the treatment, 4/10 (15%) previous non-responders still remained complete responders,All 13 previous relapsers completed the 12-month treatment course. At a mean follow up of 22months (9 - 36 months) after treatment, 6/13(46%) the previous relapsers were stillsustained complete responders.CONCLUSION Our treatment schedule of the combined therapy for 6 months of interferon alfa2a with a low dose of ribavirin (10 mg/kg/day)followed by 6 months of interferon alfa-2amonotherapy is able to induce a sustainedcomplete response rate in 15% of non-responders and 46% of relapsers with chronic hepatitis C virus-related liver diseases comparable to those obtained with the standarddoses of ribavirin 1000 - 1200 mg/day.Randomized prospective controlled trials using lower total amounts of ribavirin in combination with interferon should be

  17. Performance evaluation and optimization of the luminosity detector ALFA

    CERN Document Server

    Jakobsen, Sune; Grafström, P; Joram, C

    2010-01-01

    The startup of the LHC (Large Hadron Collider) has initialized a new era in particle physics. The standard model of particle physics has for the last 40 years with tremendous success described all measurements with phenomenal precision. The experiments at the LHC will test the standard model in a new energy regime. To normalize the measurements and understand the potential discoveries of the LHC experiments it is often crucial to know the interaction rate - the absolute luminosity. The ATLAS (A Toroidal LHC ApparatuS) detector will measure luminosity by numerous methods. But for most of the methods only the relative luminosity is measured with good precision. The absolute scale has to be provided from elsewhere. Therefore ATLAS plans to measure the flux of protons scattered under very small angles as this flux relates directly and with good precision to the absolute luminosity. This will be done by the ALFA (Absolute Luminosity For ATLAS) detector. The detectors will be positioned about 240 m from the interac...

  18. Fast Radio Burst Discovered in the Arecibo Pulsar ALFA Survey

    CERN Document Server

    Spitler, L G; Hessels, J W T; Lorimer, D R; McLaughlin, M A; Chatterjee, S; Crawford, F; Deneva, J S; Kaspi, V M; Wharton, R S; Allen, B; Bogdanov, S; Brazier, A; Camilo, F; Freire, P C C; Jenet, F A; Karako-Argaman, C; Knispel, B; Lazarus, P; Lee, K J; van Leeuwen, J; Lynch, R; Lyne, A G; Ransom, S M; Scholz, P; Siemens, X; Stairs, I H; Stovall, K; Swiggum, J K; Venkataraman, A; Zhu, W W; Aulbert, C; Fehrmann, H

    2014-01-01

    Recent work has exploited pulsar survey data to identify temporally isolated, millisecond-duration radio bursts with large dispersion measures (DMs). These bursts have been interpreted as arising from a population of extragalactic sources, in which case they would provide unprecedented opportunities for probing the intergalactic medium; they may also be linked to new source classes. Until now, however, all so-called fast radio bursts (FRBs) have been detected with the Parkes radio telescope and its 13-beam receiver, casting some concern about the astrophysical nature of these signals. Here we present FRB 121102, the first FRB discovery from a geographic location other than Parkes. FRB 121102 was found in the Galactic anti-center region in the 1.4-GHz Pulsar ALFA survey with the Arecibo Observatory with a DM = 557.4 $\\pm$ 3 pc cm$^{-3}$, pulse width of $3\\; \\pm 0.5$ ms, and no evidence of interstellar scattering. The observed delay of the signal arrival time with frequency agrees precisely with the expectation...

  19. Taliglucerase alfa: an enzyme replacement therapy using plant cell expression technology.

    Science.gov (United States)

    Grabowski, Gregory A; Golembo, Myriam; Shaaltiel, Yoseph

    2014-05-01

    Gaucher disease (GD) is a rare, genetic lysosomal storage disorder caused by functional defects of acid β-glucosidase that results in multiple organ dysfunction. Glycosylation of recombinant acid human β-glucosidase and exposure of terminal mannose residues are critical to the success of enzyme replacement therapy (ERT) for the treatment of visceral and hematologic manifestations in GD. Three commercially available ERT products for treatment of GD type 1 (GD1) include imiglucerase, velaglucerase alfa, and taliglucerase alfa. Imiglucerase and velaglucerase alfa are produced in different mammalian cell systems and require production glycosylation modifications to expose terminal α-mannose residues, which are needed for mannose receptor-mediated uptake by target macrophages. Such modifications add to production costs. Taliglucerase alfa is a plant cell-expressed acid β-glucosidase approved in the United States and other countries for ERT in adults with GD1. A plant-based expression system, using carrot root cell cultures, was developed for production of taliglucerase alfa and does not require additional processing for postproduction glycosidic modifications. Clinical trials have demonstrated that taliglucerase alfa is efficacious, with a well-established safety profile in adult, ERT-naïve patients with symptomatic GD1, and for such patients previously treated with imiglucerase. These included significant improvements in organomegaly and hematologic parameters as early as 6months, and maintenance of achieved therapeutic values in previously treated patients. Ongoing clinical trials will further characterize the long-term efficacy and safety of taliglucerase alfa in more diverse patient populations, and may help to guide clinical decisions for achieving optimal outcomes for patients with GD1.

  20. ALTAIR Radar Plasma Drifts and in situ Electric and Magnetic Field Measurements on Two Sounding Rockets and the C/NOFS Satellite in the Low Latitude Ionosphere at Sunset

    Science.gov (United States)

    Kudeki, Erhan; Pfaff, Robert; Rowland, Douglas; Klenzing, Jeffrey; Freudenreich, Henry

    2016-07-01

    We present ALTAIR incoherent scatter radar plasma drifts and in situ electric field, magnetic field, and plasma density measurements made simultaneously with probes on two sounding rockets and the C/NOFS satellite in the low latitude ionosphere in the vicinity of Kwajalein Atoll. The coincident data were gathered during sunset conditions prior to a spread-F event during the NASA EVEX Campaign. The sounding rocket apogees were 180 km and 330 km, while the C/NOFS altitude in this region was ~ 390 km. Electric field data from all three platforms display upwards vertical plasma drifts, while the zonal drifts change direction as a function of altitude and/or local time. The variable drifts provide evidence of a dynamic plasma environment which may contribute to the unstable conditions necessary for spread-F instabilities to form.

  1. Thermophysical and mechanical characterization of clay bricks reinforced by alfa or straw fibers

    Science.gov (United States)

    Elhamdouni, Y.; Khabbazi, A.; Benayad, C.; Mounir, S.; Dadi, A.

    2017-03-01

    This work is part of the valuation of local materials such as clay (earth), alfa fiber and straw fiber. The goal is to use these materials as bricks in rural construction. These materials are abundant, natural, and renewable. The objective of this work is to study the thermal and mechanical behavior of a new material by mixing clay (chosen as the binder) with different mass percentages of alfa fiber (0.5%, 1%, 2%, 3%, 4%), and to compare these results with those of materials often used in the construction of individual houses in rural Morocco (clay + straw). The results obtained prove to us that using straw fibers can reduce the thermal conductivity compared to alfa fiber, which allows to have energy savings of 2% to 7%. By against, alfa fibers can improve the mechanical behavior of clay-based materials when compared to the clay + straw material (an increase of 8% to 17% in the tractive resistance by bending and 6% to 18% for compression resistance). These results also specify the optimal usage conditions of these fibers (alfa and straw) in the clay bricks.

  2. Effects of MAPP Compatibilization and Acetylation Treatment Followed by Hydrothermal Aging on Polypropylene Alfa Fiber Composites

    Directory of Open Access Journals (Sweden)

    Noura Hamour

    2015-01-01

    Full Text Available This work investigates the effect of hydrothermal aging on the properties of polypropylene/alfa fiber composites. Hydrothermal aging was induced in an environmental testing chamber at 65°C and 75% relative humidity (RH over a 1000 h period. At the beginning (t=0 h, the results showed that Young’s moduli of the untreated alfa fibers and the acetylation-treated fibers increased by 21% and 36%, respectively, compared with the virgin polypropylene (PP. Additionally, Young’s moduli decreased by 7% for the compatibilized composites composed of maleic anhydride grafted polypropylene (MAPP. After 1000 h of aging, Young’s moduli decreased by 36% for untreated alfa fibers and 29% for the acetylation-treated alfa fibers and the compatibilized composites. Significant degradation was observed in the untreated alfa fiber samples. The Fourier transformed infrared (FTIR allows us to distinguish the characteristic absorption bands of the main chemical functions present in the composite material before and after aging. The thermal properties showed that the thermal stability and the degree of crystallinity of the composites decreased after hydrothermal aging; this result was corroborated by the dynamical mechanical analysis (DMA results.

  3. Home infusion program for Fabry disease: experience with agalsidase alfa in Argentina

    Directory of Open Access Journals (Sweden)

    Isaac Kisinovsky

    2013-02-01

    Full Text Available Fabry disease is an X-linked lysosomal storage disorder caused by inherited deficiency of the enzyme α-galactosidase A. Enzyme replacement treatment using agalsidase alfa significantly reduces pain, improves cardiac function and quality of life, and slows renal deterioration. Nevertheless, it is a life-long treatment which requires regular intravenous infusions and entails a great burden for patients. Our objective was to evaluate retrospectively the safety and tolerability of the home infusion of agalsidase alfa in patients with Fabry disease in Argentina. We evaluated all the patients with Fabry disease who received home infusion with agalsidase alfa 0.2 mg/kg between January 2005 and June 2011. The program included 87 patients; 51 males (mean age: 30 years and 36 females (mean age: 34 years. A total of 5229 infusions (mean: 59 per patient; range: 1-150 were administered. A total of 5 adverse reactions were seen in 5 patients (5.7% of patients and 0.9% of the total number of infusions. All were mild in severity and resolved by reducing the rate of infusion and by using antihistaminics. All these 5 patients were positive for IgG antibodies, but none of them presented IgE antibodies and none suffered an anaphylactic shock. In our group 18 patients were switched from agalsidase beta to agalsidase alfa without complications. Home infusion with agalsidase alfa is safe, well tolerated and is associated to high compliance.

  4. Anti-inflammatory and anti-fibrinolytic effects of thrombomodulin alfa through carboxypeptidase B2 in the presence of thrombin.

    Science.gov (United States)

    Tawara, Shunsuke; Sakai, Takumi; Matsuzaki, Osamu

    2016-11-01

    Thrombomodulin (TM) alfa, a recombinant human soluble TM, enhances activation of pro-carboxypeptidase B2 (pro-CPB2) by thrombin. Activated pro-CPB2 (CPB2) exerts anti-inflammatory and anti-fibrinolytic activities. Therefore, TM alfa may also have anti-inflammatory and anti-fibrinolytic effects through CPB2. However, these effects of TM alfa have not been elucidated. In the present study, we investigated the effects of TM alfa on inactivation of complement component C5a as an anti-inflammatory effect and prolongation of clot lysis time as an anti-fibrinolytic effect via CPB2 in vitro. CPB2 activity and tissue factor-induced thrombin generation was examined by a chromogenic assay. C5a inactivation was evaluated by C-terminal cleavage of C5a and inhibition of C5a-induced human neutrophil migration. Clot lysis time prolongation was examined by a tissue-type plasminogen activator-induced clot lysis assay. CPB2 activity in human plasma was increased by TM alfa and thrombin in a concentration-dependent manner. TM alfa inhibited tissue factor-induced thrombin generation and enhanced pro-CPB2 activation in human plasma simultaneously. The mass spectrum of C5a treated with TM alfa, thrombin, and pro-CPB2 was decreased at 156m/z, indicating that TM alfa enhanced the processing of C5a to C-terminal-cleaved C5a, an inactive form of C5a. C5a-induced human neutrophil migration was decreased after C5a treatment with TM alfa, thrombin, and pro-CPB2. TM alfa prolonged the clot lysis time in human plasma, and this effect was completely abolished by addition of a CPB2 inhibitor. TM alfa exerts anti-inflammatory and anti-fibrinolytic effects through CPB2 in the presence of thrombin in vitro. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Design and Manufacture of the Irradiation Complex "Alfa" for Track Membranes Production

    CERN Document Server

    Alenitsky, Yu G; Vylov, T D; Glazov, A A; Danilov, V I; Denisov, Yu N; Dmitrievsky, V P; Dolya, S N; Zaplatin, N L; Ivashkevich, S A; Kadyshevskij, V G; Kalinichenko, V V; Karamysheva, G A; Klimkin, I P; Kochkin, V A; Morozov, N A; Novikov, D L; Smolkov, A V; Tolstoy, N S; Tychkov, Yu I; Utkin, V A; Fedorenko, S B; Chesnov, A F

    2004-01-01

    The film irradiation complex "Alfa" intended for exposing the polymer films used in the track membranes production was designed and manufactured at the Joint Institute for Nuclear Research for "Trackpore Technology" holding company. The complex consists of the isochronous cyclotron with external injection of ions, the extraction system, the beam transport of accelerated ions and the film irradiation chamber. The complex "Alfa" produces polyethylene terephthalate track membranes with less than 25 {\\mu}m thickness and less than 40 cm width. The film irradiation complex "Alfa" started working in August 2002. Argon ions were accelerated to the project energy - 2.4 MeV/nucleon, extracted beam intensity was about 200 nA, extraction efficiency totaled \\sim 50 %.

  6. Dificuldades na identificação laboratorial da talassemia alfa

    OpenAIRE

    Dias-Penna,Karlla Greick Batista; Melo-Reis,Paulo Roberto de; Mesquita, Mauro Meira de; Silva, Jairo Batista da; Bataus,Luiz Artur Mendes

    2010-01-01

    Introdução: Talassemia alfa é uma síndrome associada à redução da síntese de cadeias de globina do tipo alfa. A gravidade das manifestações clínicas está relacionada com a quantidade de globinas produzida e a estabilidade das cadeias beta presentes em excesso. A talassemia alfa mínima resulta da deleção de apenas um dos quatro genes a (-α/αα). Clinicamente apresenta anemia leve com microcitose ou ausência de anemia, sendo o diagnóstico realizado por meio de visualização da hemo...

  7. Baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF)

    NARCIS (Netherlands)

    McMurray, John J. V.; Anand, Inder S.; Diaz, Rafael; Maggioni, Aldo P.; O'Connor, Christopher; Pfeffer, Marc A.; Solomon, Scott D.; Tendera, Michal; van Veldhuisen, Dirk J.; Albizem, Moetaz; Cheng, Sunfa; Scarlata, Debra; Swedberg, Karl; Young, James B.

    2013-01-01

    Aims This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital ad

  8. The ATLAS ALFA and AFP detectors - the experimental challenge of measuring forward protons at the LHC

    CERN Document Server

    Trzebinski, M; The ATLAS collaboration

    2013-01-01

    The Absolute Luminosity For ATLAS (ALFA) and ATLAS Forward Protons (AFP) detectors are introduced. The forward proton trajectories are shown. The similarities and differences between these two detector systems are described. Finally, the physics possible to be done in these forward detectors is discussed. In particular, in case of ALFA the elastic scattering and exclusive di-pion production are described. In case of AFP, the hard diffractive processes like: Single Diffractive Jet, Double Pomeron Exchange Jet, Exclusive Jet and anomalous coupling production are described.

  9. Agregación de alfa-sinucleína y degeneración Parkinsoniana

    OpenAIRE

    Fernández-Espejo, Emilio

    2013-01-01

    La alfa-sinucleína es la proteína principal de los cuerpos de Lewy, marcador anatomopatológico de la enfermedad de Parkinson. Dicha proteína puede ver alterada su conformación y adquirir capacidad autoagregante, lo que se relaciona con el depósito de agregados proteináceos en las neuronas y podría constituir un factor fisiopatológico importante en dicha enfermedad. Los agregados poseen fibrillas de alfa-sinucleína alterada, y las moléculas se encuentran unidas entre sí por enlaces no...

  10. ESTABILIZACIÓN DE HOLO-alfa-LACTOALBÚMINA EN PRESENCIA DE POLIOLES

    Directory of Open Access Journals (Sweden)

    Alberto Albis

    2010-02-01

    Full Text Available En este trabajo se presenta un estudio sistemático sobre el efecto de las soluciones acuosas de eritritol, xilitol, sorbitol e inositol con diferentes concentraciones, sobre la estabilidad térmica de la holo- alfa-lactoalbúmina bovina con pH 6,5 usando espectroscopia UV-VIS. Los resultados obtenidos muestran que los polioles usados estabilizan la holo-alfa-lactoalbúmina en un grado significativamente menor al reportado para otras proteínas. Se sugiere que este menor efecto de estabilización ocurre debido a que esta proteína presenta un estado desnaturalizado parcialmente desdoblado.

  11. Agregación de alfa-sinucleína y degeneración Parkinsoniana

    OpenAIRE

    Fernández-Espejo, Emilio

    2013-01-01

    La alfa-sinucleína es la proteína principal de los cuerpos de Lewy, marcador anatomopatológico de la enfermedad de Parkinson. Dicha proteína puede ver alterada su conformación y adquirir capacidad autoagregante, lo que se relaciona con el depósito de agregados proteináceos en las neuronas y podría constituir un factor fisiopatológico importante en dicha enfermedad. Los agregados poseen fibrillas de alfa-sinucleína alterada, y las moléculas se encuentran unidas entre sí por enlaces no...

  12. Role of neutral wind and storm time electric fields inferred from the storm time ionization distribution at low latitudes: in-situ measurements by Indian satellite SROSS-C2

    Directory of Open Access Journals (Sweden)

    P. Subrahmanyam

    2005-11-01

    Full Text Available Recently, there has been a renewal of interest in the study of the effects of solar weather events on the ionization redistribution and irregularity generation. The observed changes at low and equatorial latitudes are rather complex and are noted to be a function of location, the time of the storm onset and its intensity, and various other characteristics of the geomagnetic storms triggered by solar weather events. At these latitudes, the effects of geomagnetic storms are basically due to (a direct penetration of the magnetospheric electric fields to low latitudes, (b development of disturbance dynamo, (c changes in atmospheric neutral winds at ionospheric level and (d changes in neutral composition triggered by the storm time atmospheric heating.

    In the present study an attempt is made to further understand some of the observed storm time effects in terms of storm time changes in zonal electric fields and meridional neutral winds. For this purpose, observations made by the Retarding Potential Analyzer (RPA payload on board the Indian satellite SROSS-C2 are examined for four prominent geomagnetic storm events that occurred during the high solar activity period of 1997-2000. Available simultaneous observations, from the GPS satellite network, are also used. The daytime passes of SROSS-C2 have been selected to examine the redistribution of ionization in the equatorial ionization anomaly (EIA region. In general, EIA is observed to be weakened 12-24 h after the main phase onset (MPO of the storm. The storm time behaviour inferred by SROSS-C2 and the GPS satellite network during the geomagnetic storm of 13 November 1998, for which simultaneous observations are available, is found to be consistent. Storm time changes in the delay of received GPS signals are noted to be ~1-3 m, which is a significant component of the total delay observed on a quiet day.

    An attempt is made to identify and

  13. 利用GPS数据研究低纬度环球剪切带的活动性%AN ANALYSIS OF FAULT ACTIVITY IN SHEAR ZONE AT LOW LATITUDES FROM GPS MEASUREMENTS

    Institute of Scientific and Technical Information of China (English)

    朱泽; 孟国杰

    2012-01-01

    Global Positioning System (GPS) measure campaign in shear zone at low-latitudes was conducted in 1991 and 2003, for quantifying the present-day major faults' activity. The results are as follow,the north Antolia fault , Jiali fault, Sagaing fault and Sumatra fault are right lateral motion, the rates are(13.7±0. 6),(5.8±0.5) (7.1 ± 1.0) , (12.7 ±0.2) and(25. 4 ± 0. 5 ) mm/a respectively; while the Sorong fault and Guatemala fault are left lateral motion , the rates are 29.2 ±1.8),(14. 1 ±1.0) mm/a, respectively . Besides, Sumatra fault and Jiali fault also show strong squeezing, (18.5 ±1.0), (15.2±0.6) mm / a, respectively, while Sorong fault show powerful pull, reached to:(10.7±l.l) mm / a. Overall, the shear activity dominats in the shear zone at low-latitudes.%利用GPS速度研究了低纬度环球剪切带主要断裂的活动性,结果显示:北安纳托利亚断裂、北高加索断裂、嘉黎断裂、实皆断裂以及苏门答腊断裂均表现为右旋走滑特征,滑动速率分别为13.7±0.6、5.8±0.5、7.1±1.0、12.7±0.2和25.4±0.5 mm/a;索龙断裂和危地马拉断裂呈现左旋走滑特征,滑动速率分别为29.2±1.8、14.1±1.0 mm/a;嘉黎断裂和苏门答腊断裂表现出强挤压性,挤压量分别为18.5±1.0、15.2±0.6mm/a;索龙断裂表现出强拉张性,拉张量为10.7±1.1 mm/a.低纬度剪切带总体上表现出较强的活动性并以剪切活动为主.

  14. 国外低纬高原地区农业发展对云南的启示研究%Implications of Agricultural Development in Foreign Low Latitude Plateau Regions for Yunan Province

    Institute of Scientific and Technical Information of China (English)

    罗雁; 杨妍; 陈蕊; 武卫; 钱敏; 陈良正; 李学林

    2013-01-01

    The climatic characteristics of foreign low latitude plateau regions were introduced.Then,the experience and lessons of major foreign low latitude plateau countries in developing modem agriculture were analyzed,including Indian three times agricultural revolution and agricultural informationization development,application of agricultural biotechnology in Brazil,trade liberalization and economic de-agriculture of Mexico,and Argentina,Saudi Arabia and South Africa attach great importance to developing modern agriculture relying on science and technology and pay close attention to resource conservation and environmental protection.Combining natural and social resource characteristics of Yunnan plateau agriculture,pertinent implications and recommendations for modem agricultural development in Yunnan were put forward.Specifically,these include strengthening agricultural sci-tech research and development,and population and application; transforming agricultural development model; enhancing agricultural resource conservation and environmental protection; accelerating developing mountain organic ecological agricultural and autumn agriculture; reinforcing urban and rural integration to develop plateau characteristic agriculture on the basis of local actual conditions.%介绍了低纬高原地区气候特点,分析了国外低纬高原地区主要国家发展现代农业的经验和教训,如印度农业的“三大革命”和农业信息化发展;巴西农业生物技术的应用;墨西哥“贸易自由化”与经济“去农业化”使其农业丧失比较优势;阿根廷、沙特阿拉伯、南非等国家十分重视依靠科技发展现代农业,重视资源节约和环境保护.结合云南高原农业自然和社会资源条件特点,有针对性地提出了云南高原特色现代农业发展的启示建议:应加强农业科技研发和推广应用,努力转变农业发展方式;强化农业资源节约和环境保护,加快发展山区有机生态农

  15. Low Latitude Aeronomy Study in Africa

    Science.gov (United States)

    2016-02-09

    was acquired and an aluminum base plate was attached to the optical dome for mounting on the top of the house for the instrument. The dome was...Preparation in Ivory Coast NCAR also worked closely with our Ivory Coast colleagues to make the necessary preparation for the site. An optical dome ...constructed a new hut to house the FPI with their funding (Figure 2). Figure 2. The hut (under construction earlier in 2015) in Korhogo Ivory

  16. Geomagnetic activity control on VHF scintillations over an Indian low latitude station, Waltair (17.7°N, 83.3°E, 20°N dip)

    Indian Academy of Sciences (India)

    D S V V D Prasad; P V S Rama Rao; G Uma; S Gopi Krishna; K Venkateswarlu

    2005-08-01

    Using the data of amplitude scintillations recorded at 244MHz from the geostationary satellite, FLEETSAT (73°E) at a low latitude station, Waltair (17.7°N, 83.3°E, 20°N dip), during the increasing sunspot activity period of 1997-2000, the effect of the geomagnetic storms on the occurrence of ionospheric scintillations has been studied. A total of 60 SC storms studied during this period, following the Aarons' criterion, reveals that the local time of onset of the recovery phase of the geomagnetic storms play an important role in the generation or inhibition of the ionospheric irregularities. Out of the 60 storms studied, nearly 60 to 70% satisfied the categories I, II and III of Aarons' criteria. However, in the remaining 30 to 40% of the cases, no consistent results were observed. Thus, there is a necessity for further investigation of the effect of geomagnetic storms on ionospheric irregularities, particularly with reference to the altitude variations of the F-layer (h'F) relating to the changes in the local electric fields.

  17. Diagnóstico molecular da talassemia ALFA+ (DELEÇÃO -3.7) em indivíduos com microcitose e/ou hipocromia

    OpenAIRE

    Bezerra, Christiane Medeiros

    2009-01-01

    A talassemia alfa, uma das doenças monogênicas mais comuns no mundo, resulta de um desequilíbrio na síntese das cadeias alfa da hemoglobina devido, principalmente, à deleção de um ou ambos os genes da globina alfa, sendo a deleção - a mais freqüente. A talassemia alfa, juntamente com a deficiência de ferro e a talassemia beta, representa uma importante causa de microcitose e hipocromia. Com o objetivo de diagnosticar e verificar a prevalência da talassemia alfa (-3.7) em indivíduos co...

  18. Diagnóstico molecular da talassemia ALFA+ (DELEÇÃO -3.7) em indivíduos com microcitose e/ou hipocromia

    OpenAIRE

    Bezerra, Christiane Medeiros

    2009-01-01

    A talassemia alfa, uma das doenças monogênicas mais comuns no mundo, resulta de um desequilíbrio na síntese das cadeias alfa da hemoglobina devido, principalmente, à deleção de um ou ambos os genes da globina alfa, sendo a deleção - a mais freqüente. A talassemia alfa, juntamente com a deficiência de ferro e a talassemia beta, representa uma importante causa de microcitose e hipocromia. Com o objetivo de diagnosticar e verificar a prevalência da talassemia alfa (-3.7) em indivíduos co...

  19. The Synchrony and Diachrony of Bosnian-Croatian-Serbian Adjectival Long-Form Allomorphy (ALFA)

    Science.gov (United States)

    Pennington, James Joshua

    2010-01-01

    In Bosnian-Croatian-Serbian (BCS), the gentive (G) and dative/locative (DL) cases exhibit adjectival long-form allomorphy (ALFA). The genitive -"og" -"oga" and the DL -"om" -"ome" -"omu" stand in free variation, inasmuch as when one form is substituted for another the truth value of an utterance…

  20. High antibody titer in an adult with Pompe disease affects treatment with alglucosidase alfa.

    Science.gov (United States)

    de Vries, Juna M; van der Beek, Nadine A M E; Kroos, Marian A; Ozkan, Lale; van Doorn, Pieter A; Richards, Susan M; Sung, Crystal C C; Brugma, Jan-Dietert C; Zandbergen, Adrienne A M; van der Ploeg, Ans T; Reuser, Arnold J J

    2010-12-01

    Clinical trials have demonstrated beneficial effects of enzyme replacement therapy (ERT) with alglucosidase alfa in infants, children and adults with Pompe disease. Recent studies have shown that high antibody titers can occur in patients receiving ERT and counteract the effect of treatment. This particularly occurs in those patients with classic-infantile Pompe disease that do not produce any endogenous acid α-glucosidase (CRIM-negative). It is still unclear to what extent antibody formation affects the outcome of ERT in adults with residual enzyme activity. We present the case of a patient with adult-onset Pompe disease. He was diagnosed at the age of 39years by enzymatic testing (10.7% residual activity in fibroblasts) and DNA analysis (genotype: c.-32-13T>G/p.Trp516X). Infusion-associated reactions occurred during ERT and the patient's disease progressed. Concurrently, the antibody titer rose to a similarly high level as reported for some CRIM-negative patients with classic-infantile Pompe disease. Using newly developed immunologic-assays we could calculate that approximately 40% of the administered alglucosidase alfa was captured by circulating antibodies. Further, we could demonstrate that uptake of alglucosidase alfa by cultured fibroblasts was inhibited by admixture of the patient's serum. This case demonstrates that also patients with an appreciable amount of properly folded and catalytically active endogenous acid α-glucosidase can develop antibodies against alglucosidase alfa that affect the response to ERT.

  1. A Trial of Darbepoetin Alfa in Type 2 Diabetes and Chronic Kidney Disease

    NARCIS (Netherlands)

    Pfeffer, Marc A.; Burdmann, Emmanuel A.; Chen, Chao-Yin; Cooper, Mark E.; de Zeeuw, Dick; Eckardt, Kai-Uwe; Feyzi, Jan M.; Ivanovich, Peter; Kewalramani, Reshma; Levey, Andrew S.; Lewis, Eldrin F.; McGill, Janet B.; McMurray, John J. V.; Parfrey, Patrick; Parving, Hans-Henrik; Remuzzi, Giuseppe; Singh, Ajay K.; Solomon, Scott D.; Toto, Robert

    2009-01-01

    BACKGROUND Anemia is associated with an increased risk of cardiovascular and renal events among patients with type 2 diabetes and chronic kidney disease. Although darbepoetin alfa can effectively increase hemoglobin levels, its effect on clinical outcomes in these patients has not been adequately te

  2. Artur Gas, editor de Josep Pla: breu història d'Ediciones Alfa

    OpenAIRE

    Pla, Xavier

    1997-01-01

    Repàs de la trajectòria professional com a editor, començant com a editor de caire socialista i acabant col·laborant amb la dictadura de Primo de Rivera. Es fa especial menció al seu paper com a editor de Josep Pla i a la seva editorial, Ediciones Alfa

  3. Spotlight on taliglucerase alfa in the treatment of pediatric patients with type 1 Gaucher disease

    Directory of Open Access Journals (Sweden)

    Gupta P

    2017-06-01

    Full Text Available Punita Gupta,1 Gregory M Pastores2 1Division of Genetics, Department of Pediatrics, St. Joseph’s Children’s Hospital, Paterson, New Jersey, USA; 2National Center for Inherited Metabolic Disorders, Mater Misericordiae University Hospital, University College Dublin, Dublin, Ireland Abstract: Gaucher disease (GD is a heritable storage disorder caused by functional defects of the lysosomal acid β-glucosidase and the accumulation of glucosylceramide within macrophages, resulting in multiple organ dysfunction. There are three commercially available enzyme replacement therapy (ERT products for the treatment of GD type 1 (GD1: imiglucerase, velaglucerase alfa, and taliglucerase alfa. Imiglucerase and velaglucerase alfa are produced in different mammalian cell systems; imiglucerase requires postproduction deglycosylation to expose terminal α-mannose residues, which are required for mannose receptor-mediated uptake by target macrophages. These steps are critical to the success of ERT for the treatment of visceral and hematologic manifestations of GD. Taliglucerase alfa is the first US Food and Drug Administration-approved plant-cell-expressed recombinant human protein, using carrot root cell cultures. Furthermore, it does not require postproduction glycosidic modifications. It is indicated for treatment of adults with GD1 in the US, Israel, Australia, Canada, Chile, Brazil, and other countries, and it is additionally approved for the treatment of pediatric patients in the US, Australia, and Canada and for the treatment of hematologic manifestations in pediatric patients with Type 3 GD in Canada and other countries. Our review focuses on the role of taliglucerase alfa in the pediatric population. A literature search through PubMed (from 1995 up till November 2016 of English language articles was performed with the following terms: Gaucher disease, lysosomal storage disease, taliglucerase. Secondary and tertiary references were obtained by reviewing

  4. Drotrecogin alfa (activated in severe sepsis: a systematic review and new cost-effectiveness analysis

    Directory of Open Access Journals (Sweden)

    Brophy James M

    2007-06-01

    Full Text Available Abstract Background Activated drotrecogin alfa (human activated protein C, rhAPC, is produced by recombinant DNA technology, and purports to improve clinical outcomes by counteracting the inflammatory and thrombotic consequences of severe sepsis. Controversy exists around the clinical benefits of this drug and an updated economic study that considers this variability is needed. Methods A systematic literature review was performed using Medline, Embase and the International Network of Agencies for Health Technology Assessment (INAHTA databases to determine efficacy, safety and previous economic studies. Our economic model was populated with systematic estimates of these parameters and with population life tables for longer term survival information. Monte Carlo simulations were used to estimate the incremental cost-effectiveness ratios (ICERs and variance for the decision analytic models. Results Two randomized clinical trials (RCTS of drotrecogin alfa in adults with severe sepsis and 8 previous economic studies were identified. Although associated with statistical heterogeneity, a pooled analysis of the RCTs did not show a statistically significant 28-day mortality benefit for drotrecogin alfa compared to placebo either for all patients (RR: 0.93, 95% CI: 0.69, 1.26 or those at highest risk as measured by APACHE II ≥ 25 (RR: 0.90, 95% CI: 0.54, 1.49. Our economic analysis based on the totality of the available clinical evidence suggests that the cost-effectiveness of drotrecogin alfa is uncertain ( Conclusion The evidence supporting the clinical and economic attractiveness of drotrecogin alfa is not conclusive and further research appears to be indicated.

  5. Long-term effect of epoetin alfa on clinical and biochemical markers in friedreich ataxia.

    Science.gov (United States)

    Saccà, Francesco; Puorro, Giorgia; Marsili, Angela; Antenora, Antonella; Pane, Chiara; Casali, Carlo; Marcotulli, Christian; Defazio, Giovanni; Liuzzi, Daniele; Tatillo, Chiara; Cambriglia, Donata Maria; Schiano di Cola, Giuseppe; Giuliani, Luigi; Guardasole, Vincenzo; Salzano, Andrea; Ruvolo, Antonio; De Rosa, Anna; Cittadini, Antonio; De Michele, Giuseppe; Filla, Alessandro

    2016-05-01

    Friedreich ataxia is an autosomal recessive disease with no available therapy. Clinical trials with erythropoietin in Friedreich ataxia patients have yielded conflicting results, and the long-term effect of the drug remains unknown. We designed a double-blind, placebo-controlled, multicenter trial to test the efficacy of epoetin alfa on 56 patients with Friedreich ataxia. The primary endpoint of the study was the effect of epoetin alfa on peak oxygen uptake (VO2 max) at the cardiopulmonary exercise test. Secondary endpoints were frataxin levels in peripheral blood mononuclear cells, improvement in echocardiography findings, vascular reactivity, neurological progression, upper limb dexterity, safety, and quality of life. Epoetin alfa or placebo (1:1 ratio) was administered subcutaneously at a dose of 1200 IU/Kg of body weight every 12 weeks for 48 weeks. A total of 56 patients were randomized; 27 completed the study in the active treatment group, and 26 completed the study in the placebo group[KG1]. VO2 max was not modified after treatment (0.01 [-0.04 to 0.05]; P = .749), as well as most of the secondary endpoint measures, including frataxin. The 9-hole peg test showed a significant amelioration in the treatment group (-17.24 sec. [-31.5 to -3.0]; P = .018). The treatment was safe and well tolerated. Although results are not in favor of an effect of epoetin alfa in Friedreich ataxia, this is the largest trial testing its effect. It is still possible that epoetin alfa may show some symptomatic effect on upper-limb performance. This study provides class I evidence that erythropoietin does not ameliorate VO2 max in patients with Friedreich ataxia. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  6. Diagnotistic analysis and numerical simulation of severe convection on February 28,2008 in low - latitude plateau%2008年"2.28"低纬高原强对流成因诊断与数值模拟

    Institute of Scientific and Technical Information of China (English)

    尤红; 肖子牛; 艾永智

    2011-01-01

    Using the convention observed data,the NCEP1° × 1° grid point material, the mesoscale numerical model WRF, the severe convection in low - latitude plateau on February 28,2008 has been diagnotistic analysed and numerical simulated. The result shows that the severe convection, which occurred under the Spring low temperature, freezing calamity and potential stability condition,cause include strong vertical wind shear, wet low level, adequate vapor served and severe lift movement. In this extremely convection process, severe convection result in the rapid release of strong absolute baroclinic instability, which happen about the wet lingua of low level. The negative twenty degree Celsius layer over hailstorm, thunderstorm snow region on 450 hPa level, the temperature gradient between zero and negative twenty degree celsius of hailstorm is bigger than the thunderstorm snow' s, the saturated vapor location of hailstorm is higher. Vertical dry potential vorticity ( PV) takes on the characteristic of the upper troposphere high PV of strong dry and cold northwest air tends downwards to the low - level and low - latitude, which join with the worm, wet southwest jet on middle and low - level. The WRF simulation scheme in the test has good simulated capability, the case that strong vertical wind shear can cause sever convection under potential stability condition are well validated, the simulation results by WRF meso - scale numerical model such as horizontal wind,lifted condensation level and max convective available potential energy can well indicate the occurrence and kind of strong convection in Yunnan.%利用常规观测、NCEP1°×1°再分析资料和中尺度WRF模式,对低纬高原云南2008年"2.28"强对流进行成因诊断和数值模拟研究,结果表明:此次复杂强对流在春季低温冷冻灾害和位势稳定背景下,由强垂直风切变、低层潮湿和足够水汽供应以及强抬升机制共同作用造成.过程中,强对流由强斜压不稳

  7. A comparative study of night-time enhancement of TEC at a low latitude station on storm and quiet nights including the local time, seasonal and solar activity dependence

    Directory of Open Access Journals (Sweden)

    K. Unnikrishnan

    Full Text Available The main characteristics of night-time enhancements in TEC during magnetic storms are compared with those during quiet nights for different seasons and solar activity conditions at Palehua, a low latitude station during the period 1980–1989. We find that the mean amplitude has both a seasonal and solar activity dependence: in winter, the values are higher for weak storms as compared to those during quiet nights and increase with an increase in solar activity. In summer, the mean amplitude values during weak storms and quiet nights are almost equal. But during equinox, the mean amplitude values for quiet nights are greater than those during weak storms. The mean half-amplitude duration is higher during weak storms as compared to that during quiet nights in summer. However, during winter and equinox, the durations are almost equal for both quiet and weak storm nights. For the mean half-amplitude duration, the quiet night values for all the seasons and equinoctial weak storm values increase with an increase in solar activity. The occurrence frequency (in percent of TEC enhancement during weak storms is greater than during quiet nights for all seasons. The mean amplitude, the mean half-amplitude duration and the occurrence frequency (in percent of TEC enhancement values are higher during major storms as compared to those during quiet nights. The above parameters have their highest values during pre-midnight hours. From the data analysed, this behaviour is true in the case of major storms also.

    Key words. Ionosphere (ionospheric disturbances; plasma convection Magnetospheric physics (storms and substorms

  8. Comportamiento de glicinina, beta-conglicinina y alfa-amilasa en semillas de soja deterioradas y no deterioradas

    National Research Council Canada - National Science Library

    Salinas, Adriana Rita; Yoldjian, Ana Maria; Dietrich, María Lucrecia; Craviotto, Roque Mario; Bisaro, Vilma

    2002-01-01

    El objetivo del trabajo fue estudiar el comportamiento de glicinina y beta-conglicinina y la actividad de alfa-amilasa en semillas deterioradas y no deterioradas de 10 cultivares de soja [Glycine max (L.) Merr...

  9. Stroke in patients with type 2 diabetes mellitus, chronic kidney disease, and anemia treated with Darbepoetin Alfa

    DEFF Research Database (Denmark)

    Skali, Hicham; Parving, Hans-Henrik; Parfrey, Patrick S

    2011-01-01

    More strokes were observed in the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT) among patients assigned to darbepoetin alfa. We sought to identify baseline characteristics and postrandomization factors that might explain this association....

  10. Darbepoietin-alfa has comparable erythropoietic stimulatory effects to recombinant erythropoietin whilst preserving the bone marrow microenvironment.

    Science.gov (United States)

    Dewamitta, Sita R; Russell, Megan R; Nandurkar, Harshal; Walkley, Carl R

    2013-05-01

    Erythropoiesis stimulating agents are widely used for the treatment of anemia. Recently, we reported erythroid expansion with impaired B lymphopoiesis and loss of trabecular bone in C57BL/6 mice following ten days of treatment with low-dose short acting recombinant human erythropoietin. We have assessed erythropoietin against longer-acting darbepoietin-alfa at a comparable erythroid stimulatory dosage regime. Darbepoietin-alfa and erythropoietin induced similar in vivo erythropoietic expansion. Both agents induced an expansion of the colony-forming unit-erythroid populations. However, unlike erythropoietin, darbepoietin-alfa did not impair bone marrow B lymphopoiesis. Strikingly the bone loss observed with erythropoietin was not apparent following darbepoietin-alfa treatment. This analysis demonstrates that whilst darbepoietin-alfa has similar in vivo erythropoietic potency to erythropoietin, it preserves the bone marrow microenvironment. Thus erythropoietin and darbepoietin-alfa manifest different action showing that erythropoiesis stimulating agents have differential non-erythroid effects dependent on their duration of action.

  11. A Study of Diffractive Scattering with the ATLAS and ALFA Experiment

    CERN Document Server

    Lind, Alexander Pedersen

    This thesis presents a study of diffractive scattering of high-energy protons. Hadronic diffraction is not well-understood and many alternative approaches exist. The Monte Carlo event generator Pythia 8 follows a Pomeron-based approach, where the invariant mass of the diffractive system and the squared momentum transfer $t$ of the system is set up according to a phenomenological Pomeron flux parameterization, which is parameterized by the super-critical Pomeron trajectory, $\\alpha(t) = 1 + \\varepsilon + \\alpha' t$, where the intercept parameter $\\varepsilon$ and the slope parameter $\\alpha'$ can be tuned by the user. A fast detector response simulation of the ALFA and ATLAS detectors has been developed in the Rivet toolkit for the purposes of this thesis. The developed simulation framework is able to handle the beam transport of diffractively scattered protons as well as impose the kinematic acceptance of the ALFA detector which was found to be approximately $\\xi \\lesssim 0.22$, with a pseudorapidity coverag...

  12. Deficiência de alfa-1 antitripsina: diagnóstico e tratamento

    OpenAIRE

    2008-01-01

    A deficiência de alfa-1 antitripsina é um distúrbio genético de descoberta recente e que ocorre com freqüência comparável à da fibrose cística. Resulta de diferentes mutações no gene SERPINA1 e tem diversas implicações clínicas. A alfa-1 antitripsina é produzida principalmente no fígado e atua como uma antiprotease. Tem como principal função inativar a elastase neutrofílica, impedindo a ocorrência de dano tecidual. A mutação mais freqüentemente relacionada à doença clínica é o alelo Z, que de...

  13. Development of a detector (ALFA) to measure the absolute LHC luminosity at ATLAS

    CERN Document Server

    Mapelli, A; Ask, S; Barrillon, P; Blanchot, G; Blin, S; Braem, André; Cheiklali, C; de La Taille, C; Di Girolamo, B; Efthymiopoulos, I; Faustino, J; Fournier, D; Franz, S; Grafström, P; Gurriana, L; Haguenauer, M; Hedberg, V; Heller, M; Hoffmann, S; Iwanski, W; Joram, C; Kocnar, A; Lavigne, B; Lundberg, B; Maio, A; Maneira, M J P; Marques, C; Mjörnmark, U; Conde-Muíño, P; Puzo, P; Rijssenbeeck, M; Santos, J P; Saraiva, J G; Seguin-Moreau, N; Soares, S; Stenzel, H; Thioye, M; Valladolid-Gallego, E; Vorobel, V; 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications

    2008-01-01

    The ATLAS collaboration plans to determine the absolute luminosity of the CERN LHC at Interaction Point 1 by measuring the trajectory of protons elastically scattered at very small angles ($\\mu rad$). A scintillating fibre tracker system called ALFA (Absolute Luminosity For ATLAS) is proposed for this measurement. Detector modules will be placed above and below the LHC beam axis in roman pot units at a distance of 240 m on each side of the ATLAS interaction point. They allow the detectors to approach the beam axis to millimeter distance. Overlap detectors also based on the scintillating fibre technology, will measure the precise relative position of the two detector modules. Results obtained during beam tests at DESY and at CERN validate the detectors design and demonstrate the achievable resolution. We also report about radiation hardness studies of the scintillating fibres to estimate the lifetime of the ALFA system at different operating conditions of the LHC.

  14. The efficacy and safety of double (cepeginterferon alfa-2b and ribavirin and triple (simeprevir, cepeginterferon alfa 2b and ribavirin treatment regimens in chronic hepatitis C patients. The experience of everyday clinical practice

    Directory of Open Access Journals (Sweden)

    N. P. Blokhina

    2016-01-01

    Full Text Available The objective. To evaluate the efficacy, safety and tolerability of double (cepeginterferon alfa-2b and ribavirin and triple (simeprevir, cepeginterferon alfa 2b and ribavirin treatment regimens in chronic hepatitis C patients in everyday clinical practice of the Hepatology Center in Clinical Infectious Diseases Hospital in Moscow.Materials and methods. From 2013 to 2015 a total of 289 patients with chronic hepatitis C received antiviral therapy with cepeginterferon alfa 2b. 267 patients received combination of cepeginterferon alfa 2b and ribavirin. 22 patients received triple antiviral therapy with simeprevir, cepeginterferon alfa 2b and ribavirin. Treatment efficacy was assessed by the rate of sustained virologic response on 12/24 week after completion of antiviral therapy (SVR 12/24. In safety analysis all 289 patients were included. All cases of deterioration of the patient’s condition and laboratory abnormalities were registered throughout the treatment period and follow up.Results. 267 patients (74,5%, n=199, with 2/3 genotype, 25,5%, n = 68, with 1 genotype received cepeginterferon alfa 2b 1,5 µg/kg/week and ribavirin 800-1400 daily (weight based. 22 patients with genotype 1 (the majority of them had advanced fibrosis (F3-F4 underwent triple therapy with simeprevir 150 mg once daily in combination with cepeginterferon alfa 2b 1,5 µg/kg/week and ribavirin 800-1400 mg daily (weight based for 12 weeks, followed by cepeginterferon alfa 2b/ ribavirin therapy for 12-36 weeks. SVR was observed in 85,6% (n=113 of genotype 2/3 infected patients and in 64,6% (n=31 of genotype 1 infected patients. Among patients with mild or moderate fibrosis SVR rate was 90,7% in genotype 2/3 patients and 75% in genotype 1 patients. 21 patient completed the course of triple therapy. SVR was observed in 71,4% (n=15 of patients. Registered adverse reactions were common for interferon/ribavirin based therapy. In most cases adverse events were moderate and matched

  15. The ALFA Zone of Avoidance Survey: Results from the Precursor Observations

    CERN Document Server

    Springob, C M; Catinella, B; Day, F; Minchin, R; Momjian, E; Koribalski, B; Masters, K L; Müller, E; Pantoja, C; Putman, M; Rosenberg, J L; Schneider, S; Staveley-Smith, L

    2007-01-01

    The Arecibo L-band Feed Array Zone of Avoidance Survey (ALFA ZOA) will map 1350-1800 square degrees at low Galactic latitude, providing HI spectra for galaxies in regions of the sky where our knowledge of local large scale structure remains incomplete, owing to obscuration from dust and high stellar confusion near the Galactic plane. Because of these effects, a substantial fraction of the galaxies detected in the survey will have no optical or infrared counterparts. However, near infrared follow up observations of ALFA ZOA sources found in regions of lowest obscuration could reveal whether some of these sources could be objects in which little or no star formation has taken place ("dark galaxies"). We present here the results of ALFA ZOA precursor observations on two patches of sky totaling 140 square degrees (near l=40 degrees, and l=192 degrees). We have measured HI parameters for detections from these observations, and cross-correlated with the NASA/IPAC Extragalactic Database (NED). A significant fraction...

  16. The Arecibo Legacy Fast ALFA Survey: II. Results of Precursor Observations

    CERN Document Server

    Giovanelli, R; Kent, B R; Perillat, P; Catinella, B; Hoffman, G L; Momjian, E; Rosenberg, J L; Saintonge, A; Spekkens, K; Stierwalt, S; Brosch, N; Masters, K L; Springob, C M; Karachentsev, I D; Karachentseva, V E; Koopmann, R A; Müller, E; Van Driel, W; Van Zee, L; Giovanelli, Riccardo; Haynes, Martha P.; Kent, Brian R.; Perillat, Philip; Catinella, Barbara; Momjian, Emmanuel; Rosenberg, Jessica L.; Saintonge, Amelie; Spekkens, Kristine; Stierwalt, Sabrina; Brosch, Noah; Masters, Karen L.; Springob, Christopher M.; Karachentsev, Igor D.; Karachentseva, Valentina E.; Koopmann, Rebecca A.; Muller, Erik; Driel, Wim van; Zee, Liese van

    2005-01-01

    In preparation for the full Arecibo Legacy Fast ALFA extragalactic HI survey, precursor observations were carried out in Aug--Sep 2004 with the 7-beam Arecibo L-band feed array (ALFA) receiver system and the WAPP spectral processors. While these observations were geared mainly at testing and debugging survey strategy, hardware and software, approximately 36 hours of telescope time yielded science--quality data. From those observations, an initial list of 730 tentative detections of varying degree of reliability was extracted. Ninety--eight high signal-to-noise candidates were deemed to be bona fide HI line detections. To test our ability to discriminate cosmic signals from RFI and noise, 165 candidates ranging in reliability likelihood were re--observed with the single beam L--band wide system at Arecibo in Jan--Feb 2005. Of those, 41% were confirmed as real. We present the results of both the ALFA and single beam observations for the sample of 166 confirmed HI sources, as well as our assessment of their opti...

  17. Preparation And Properties Of Bionanocomposite Films Reinforced With Nanocellulose Isolated From Moroccan Alfa Fibres

    Directory of Open Access Journals (Sweden)

    Youssef Benyoussif

    2015-09-01

    Full Text Available Nanocellulose (NC were extracted from the Moroccan Alfa plant (Stipa tenacissima L. and characterised. These Alfa cellulosic nanoparticles were used as reinforcing phase to prepare bionanocomposite films using carboxymethyl cellulose as matrix. These films were obtained by the casting/evaporation method. The crystallinity of NC was analysed by X-ray diffraction, the dimension of NC by atomic force microscopy, molecular interactions due to incorporation of NC in carboxymethyl cellulose (CMC matrix were supported by Fourier transforms infrared (FTIR spectroscopy. The properties of the ensuing bionanocomposite films were investigated using tensile tests, water vapour permeability (WVP study and thermogravimetric analysis. With the progress of purification treatment of cellulose, the crystallinity is improved compared to the untreated fibres; this can be explained by the disappearance of the amorphous areas in cellulose chain of the plant. Consequently, the tensile modulus and tensile strength of CMC film increased by 60 and 47%, respectively, in the bionanocomposite films with 10 wt% of NC, and decrease by 8.6% for WVP with the same content of NC. The NC obtained from the Moroccan Alfa fibres can be used as a reinforcing agent for the preparation of bionanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials.

  18. Features of 3–7-day planetary-wave-type oscillations in F-layer vertical drift and equatorial spread F observed over two low-latitude stations in China

    Directory of Open Access Journals (Sweden)

    Z. Zhu

    2017-06-01

    characteristics. The results highlight the role of planetary-wave-type oscillations in the initiation and development of ESF in the Chinese low-latitude region.

  19. A remarkable sea-level drop and relevant biotic responses across the Guadalupian-Lopingian (Permian) boundary in low-latitude mid-Panthalassa: Irreversible changes recorded in accreted paleo-atoll limestones in Akasaka and Ishiyama, Japan

    Science.gov (United States)

    Kofukuda, Daisuke; Isozaki, Yukio; Igo, Hisayoshi

    2014-03-01

    , in accordance with the contemporary sea-level curve based on continental shelf records, indicates that a remarkable sea-level drop has occurred globally during the latest Capitanian. This further suggests that a cool climate likely has appeared even in the low-latitude domains in Panthalassa to cause the decline of the Middle Permian shallow-water protists/animals that adapted to warmer seawater. The Wuchiapingian biota first appeared immediately after this erosional episode, i.e., during the onset of warming after the G-LB.

  20. Long term low latitude and high elevation cosmogenic 3He production rate inferred from a 107 ka-old lava flow in northern Chile; 22°S-3400 m a.s.l.

    Science.gov (United States)

    Delunel, Romain; Blard, Pierre-Henri; Martin, Léo C. P.; Nomade, Sébastien; Schlunegger, Fritz

    2016-07-01

    Available geological calibration sites used to estimate the rate at which cosmogenic 3He is produced at the Earth's surface are mostly clustered in medium to high latitudes. Moreover, most of them have exposure histories shorter than tens of thousands of years. This lack of sites prevents a qualitative assessment of available production models used to convert cosmogenic 3He concentrations into exposure ages and/or denudation rates. It thus limits our ability to take into account the atmospheric, geomagnetic and solar modulation conditions that might have affected the production of cosmogenic nuclides in the past for longer exposure histories and in low latitude regions. We present the cosmogenic 3He production rate inferred from a new geological calibration site located in northern Chile. Five samples were collected on the surface of the largest and best-preserved lava flow of the San Pedro volcano (21.934°S-68.510°W-3390 m a.s.l.), which displays pristine crease-structure features. 40Ar/39Ar dating yields a reliable plateau age of 107 ± 12 ka for the eruption of this lava flow. Eight pyroxene aliquots separated from the surface samples yield a weighted average cosmogenic 3He concentration of 99.3 ± 1.2 Mat g-1 from which a local cosmogenic 3He production rate of 928 ± 101 at g-1 yr-1 is calculated. The local production rate is then scaled to a sea level high latitude (SLHL) reference position using different combinations of geographic spatialization schemes, atmosphere models and geomagnetic field reconstructions, yielding SLHL production rates between 103 ± 11 and 130 ± 14 at g-1 yr-1 consistent with the most recent estimates available from the literature. Finally, we use the same scaling frameworks to re-evaluate the mean global-scale cosmogenic 3He production rate in olivine and pyroxene minerals at 120 ± 16 at g-1 yr-1 from the compilation of previously published calibration datasets.

  1. A randomized controlled clinical study of lower-dose peginterferon alfa-2b in combination with ribavirin in the treatment of chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    罗端德

    2006-01-01

    Objective To compare the efficacy and safety of lower-dose peginterferon alfa-2b plus ribavirin versus standard interferon alfa-2b plus ribavirin for treatment of chronic hepatitis C in China. Methods 192 patients with chronic hepatitis C were assigned peginterferon alfa-2b 0.5μg/kg each week plus ribavirin 750~1050 mg/d or standard interferon alfa-2b 3 MIU TIW plus ribavirin 750~1050 mg/d for 48-week treatment and 24-week fellow

  2. The large scale dust distribution in the inner galaxy

    Science.gov (United States)

    Hauser, M. G.; Dwek, E.; Gezari, D.; Silverberg, R.; Kelsall, T.; Stier, M.; Cheung, L.

    1983-01-01

    Initial results are presented from a new large-scale survey of the first quadrant of the galactic plane at wavelengths of 160, 260, and 300 microns. The submillimeter wavelength emission, interpreted as thermal radiation by dust grains, reveals an optically thin disk of angular width about 0.09 deg (FWHM) with a mean dust temperature of 23 K and significant variation of the dust mass column density. Comparison of the dust column density with the gas column density inferred from CO survey data shows a striking spatial correlation. The mean luminosity per hydrogen atom is found to be 2.5 x 10 to the -30th W/H, implying a radiant energy density in the vicinity of the dust an order of magnitude larger than in the solar neighborhood. The data favor dust in molecular clouds as the dominant submillimeter radiation source.

  3. Observation of Planetary Wave Disturbances and Their Influence on Spread F in Low Latitude Region of China%中国低纬地区行星波扰动观测及其对SF的影响

    Institute of Scientific and Technical Information of China (English)

    朱正平; 高紫枫; 罗伟华

    2016-01-01

    To study the modulation mechanism of traveling planetary wave ionospheric disturbances ( TPWIDs) on F layer during pre-reversal enhancement ( PRE) and its effect on the formation and development of spread F ( SF) , in this paper, the characteristics of planetary wave disturbance is analyzed during the high SF season in china′s low latitude region, and the influence of TPWIDs phase on the formation and development of SF is investigated by the method that TPWIDs are used to refer to oscillation of the true height, which is the day-to-day variability and one of the ionosphere characteristic parameters obtained from ionogram observed by Digital Portable Sounder 4d(DPS-4D) ionosonde at sanya in 2012. The results show that TPWIDs-type oscillations controlling the strength of the electric field during PRE, therefore, slowly push the F layer height up and down according to the TPWIDs phase in the geomagnetic quiet period. the occurrence of SF is strongly controlled by the change of post-sunset F layer height and the altitude of 250 km may be a threshold at sanya, so when the the electric PRE causes the F layer bottom side to reach heights above 250 km, it is conducive to generate SF. Also during equinox ( March, April, September and October) the onset time of SF is modulated by the TPWIDs phase in such way that, when the phase greater, SF occurs earlier and when the phase smaller, SF occurs later or no SF.%为研究在日落后反转增强( PRE)期间行进式行星波电离层扰动( TPWIDs)对F层的调制机制以及对扩展F(SF)形成和发展的作用,利用三亚地区DPS-4D数字测高仪2012年探测的34080张数字频高图数据,获取了电离层特性参数-真高,以真高的逐日变化表征行进式行星波扰动,分析了中国低纬地区SF高发季节中行星波扰动特性,并研究了行星波扰动时的不同相位对SF产生和发展的影响。结果表明:地磁平静时期,在PRE期间,TPWID行星波扰动调制着PRE时期

  4. The Hybridization Effect Analysis between Potato Cultures in Low-Latitude Plateau of Lijiang%丽江低纬高原马铃薯的杂交效应分析

    Institute of Scientific and Technical Information of China (English)

    张浩; 杨继先; 和光宇; 王绍林; 和平根; 和国钧; 和忠

    2011-01-01

    With the highly heterozygous autotetraploid genetic background of potato cultures, directional breeding of a new potato variety is rather difficult.If, after the hybridization effect and the combining ability of potatoes are estimated, breeding of new potato varieties also has some rules to follow.The 93 crosses from the hybrid population of 15 potato parents planted in low-latitude plateau of Lijiang were analyzed.The results showed that the average irregular fruit rate (IFR) was 32.06% with 621 setting- flowers and 1937 pollinated flowers.There were 60 of 93 crosses to set fruits; 'Lishu6', 'GD2', 'Lishu7', 'Mira', 'NinglangA' and 'ZHXW' were suitable as female parents, and CIP004, CIP005, 'AWYY', 'GD1' and 'LSYY' were suitable as male parents.'GD2' and 'Lishu7' as male parents were no offspring, belonging to male sterility type.The flower setting percentage of 'NinglangA' as male parent was just 2%.The 19 crosses over 70% of the irregular-fruit-rate (IFR) are more from combinations of Yunnan potato landraces and CIP potato germplasms.%马铃薯高度杂合的同源四倍体遗传背景使马铃薯新品种选育的预见性较差,但对大量亲本杂交效果及其配合力的评价仍使马铃薯育种工作有一定的规律性可循.在低纬高原条件下杂交15份马铃薯亲本,配制93份杂交组合,授粉花朵1937朵,坐果621朵,平均坐果率32.06%,共计60个杂交组合坐果结实.适合做母本的品种有:'丽薯6号'、'高淀2'、'丽薯7号'、'米拉'、'宁蒗A'、'转心乌'等,CIP004、CIP005、'阿乌洋芋'、'高淀1'、'老鼠洋芋'等则适合做父本;'高淀2'和'丽薯7号'做父本完全不结实,'宁蒗A'做父本的结实率也仅有2%,均属雄性不育类型.在坐果率超过70%的19个组合中,云南地方种和CIP亲本的杂交组合居多.

  5. Raytracing of extreamely low frequency waves radiated from ionospheric artificial modulation at low latitude%低纬电离层人工调制所激发的ELF波射线追踪

    Institute of Scientific and Technical Information of China (English)

    汪枫; 赵正予; 常珊珊; 倪彬彬; 顾旭东

    2012-01-01

    通过大功率极低频(ELF)/甚低频(VLF)高频调幅波能有效地扰动低电离层电流,形成等效的ELF/VLF电离层虚拟天线,辐射ELFNLF波,所辐射出的低频信号能够传播进入到磁层,对其传播特性的研究对于理解辐射带高能电子沉降具有重要意义.本文基于磁层射线追踪理论,通过数值模拟得到在低纬地区所激发出的ELF波在磁层中的射线路径,并对其特征进行分析.数值模拟结果表明,从低纬激发的ELF波在南北半球来回弹跳,并逐渐传播到更远处,对于不同频率的ELF波,频率越高,传播距离越近,频率越低,传播距离越远,在传播过程中,ELF波会逐渐倾向于在一个固定的磁层区域附近来回反射,在此过程中波法向角也逐渐变为90°,射线方向倾向于沿着背景磁场方向传播.%Powerful high-frequency radio waves modulated at extremely low frequency (ELF) and very low frequency (VLF) can efficiently modify the lower ionospheric current which can act as an equivalent ionospheri'c antenna for the generation of ELF/VLF wave and these signals can propagate into the magnetosphere and the investigation of the propagation properties is of significance for understanding of radiation belt energetic electrons precipitation. In this paper, based on the raytracing theory, the ray paths of ELF waves in the magnetosphere are obtained using numerical modeling and the properties are analyzed. The results shows that the ELF waves generated from the low latitude reflect between the southern and northern hemisphere and propagate to the farther place gradually. For the signals with different frequencies, the higher their frequencies, the shorter their propagation distances are, the lower their frequencies, the longer their propagtion distances are. In the process, ELF waves tend to reflect near a fixed region. The normal angel increases to 90° gradually and ray direction tends to

  6. Diversidade alfa e beta no cerrado sensu strictu da Chapada Pratinha, Brasil Alfa and Beta diversity in the cerrado sensu stricto

    Directory of Open Access Journals (Sweden)

    Maria Cristina Felfili

    2001-08-01

    Full Text Available O bioma cerrado possui uma das mais ricas floras dentre as savanas mundiais com mais de 6000 espécies, abrange uma vasta extensão territorial, contém as três maiores bacias hidrográficas sul americanas, e se destaca pela elevada biodiversidade. O objetivo deste trabalho, que faz parte do Projeto Biogeografia do Bioma Cerrado, foi analisar as diversidades alfa e beta em comunidades de cerrado sensu stricto. Foram amostrados o Parque Nacional de Brasília, a Estação Ecológica de Águas Emendadas, a Area de Proteção Ambiental (APA Gama-Cabeça de Veado, Silvânia-GO, Paracatu-MG e Patrocínio-MG. A amostragem foi aleatória com 10 parcelas de 20x50m em cada área de estudo. Foram incluídas plantas lenhosas, exceto lianas, que tivessem no mínimo 5cm de diâmetro. Foi calculada a diversidade alfa pelo teste de Shannon & Wienner e o de Simpson. A diversidade beta foi calculada pelo índice de Whittaker que mede a mudança ou taxa de substituição na composição de espécies de um local para outro. Foi efetuada a curva espécie-área para as 60 parcelas amostradas e efetuada a classificação por TWINSPAN. O cerrado sensu stricto da Chapada Pratinha pode ser diferenciado em duas zonas fitogeográficas: Distrito Federal-Silvânia e Paracatu-Patrocínio. Estas coincidem com um zoneamento por sistemas de terra que classifica a primeira zona como terras altas em contraposição à segunda.The cerrado flora is one of the richest among the world's savannas with more than 6000 species. The cerrado covers a large territory, contains the three most important hydrographycal basins in South America and a high diversity. The objective of this work, that is part of the project Biogeography of the Cerrado Biome, was to analyse alfa and beta diversity in the cerrado sensu stricto. The sampled places were: Brasília National Park -- DF, Águas Emendadas Ecological Station -- DF, Environmentally protected Area of Gama-Cabeça de Veado -- DF, Silv

  7. Interferón alfa-2b tópico como primera opción en las neoplasias intraepiteliales corneoconjuntivales Topical interferon alfa-2b for primary treatment of conjunctiva-cornea intraepithelial neoplasia

    Directory of Open Access Journals (Sweden)

    M. Pérez de Arcelus

    2012-04-01

    Full Text Available Se describen dos casos de neoplasia intraepitlelial corneo-conjuntival (CIN tratados con interferón alfa-2b (IFN alfa-2b tópico como primera elección. El tratamiento clásico de los CIN ha sido tradicionalmente la resección completa con márgenes de seguridad seguida de crioterapia en el lecho quirúrgico. No obstante, y puesto que la tasa de recidivas puede alcanzar el 50% han sido propuestos coadyuvantes como la mitomicina C y el 5 fluoracilo, con el consiguiente riesgo de toxicidad corneal y límbica. El IFN alfa-2b presenta una eficacia similar a la cirugía en la erradicación completa de la masa tumoral como primera opción, con escasos efectos secundarios y nulo potencial carcinogénico, incluso en casos de recurrencia a terapia con mitomicina C, lesiones quirúrgicas residuales y formas difusas.We describe two cases of conjunctival-cornea intraepithelial neoplasia (CIN, treated with topical IFN alfa 2b. The traditional treatment for CIN is surgical excision usually with adjunctive cryotherapy. However, residual tumour may remain, which can lead to recurrence rates of more than 50%. 5-Fluorouracil, mitomicyn C and interferon alfa 2b are new pharmacological agents that have proved their efficacy in the treatment of CIN. As side effects are common, we present IFN alfa 2b as a single therapeutic agent as an effective and optimal treatment for presumed recurrent corneal and conjunctival intraepithelial neoplasia. It offers the benefits of topical therapy and avoids the risks of surgical or other interventions - specifically, ocular surface toxicity, cicatricial conjunctival changes, and limbal stem cell deficiency.

  8. Prospective surveillance study of haemophilia A patients switching from moroctocog alfa or other factor VIII products to moroctocog alfa albumin-free cell culture (AF-CC) in usual care settings.

    Science.gov (United States)

    Parra Lopez, Rafael; Nemes, Laszlo; Jimenez-Yuste, Victor; Rusen, Luminita; Cid, Ana R; Charnigo, Robert J; Baumann, James A; Smith, Lynne; Korth-Bradley, Joan M; Rendo, Pablo

    2015-10-01

    This prospective, open-label, postauthorisation safety surveillance study assessed clinically significant inhibitor development in patients with severe haemophilia A transitioning from moroctocog alfa or other factor VIII (FVIII) replacement products to reformulated moroctocog alfa (AF-CC). Males aged ≥ 12 years with severe haemophilia A (FVIII:C) 150 exposure days (EDs) to recombinant or plasma-derived FVIII products, and no detectable inhibitor at screening were enrolled. Primary end point was the incidence of clinically significant FVIII inhibitor development. Secondary end points included annualised bleeding rate (ABR), less-than-expected therapeutic effect (LETE), and FVIII recovery. Patients were assigned to one of two cohorts based on whether they were transitioning to moroctocog alfa (AF-CC) from moroctocog alfa (cohort 1; n=146) or from another recombinant or plasma-derived FVIII product (cohort 2; n=62). Mean number of EDs on study was 94 (range, 1-139). Six positive FVIII inhibitor results, as determined by local laboratories, were reported in four patients; none were confirmed by a central laboratory, no inhibitor-related clinical manifestations were reported, and all anti-FVIII antibody assays were negative. Median ABRs were 23.4 and 3.4 in patients categorised at baseline as following on-demand and prophylactic regimens, respectively; 86.5% of bleeding episodes resolved after one infusion. LETE incidence was 0.06% and 0.19% in the on-demand and prophylaxis settings, respectively. FVIII recovery remained constant throughout the study. No new safety concerns were identified. This study found no increased risk of clinically significant FVIII inhibitor development in patients transitioning from moroctocog alfa or other FVIII replacement products to moroctocog alfa (AF-CC).

  9. Homeopathic dilutions of TNF-alfa in psoriasis and rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Ioana Cridon

    2012-09-01

    Full Text Available Aim: Clinical and biological studies in the past years underlined the proinflammatory action of the citokine Tumoral Necrosis Factor in the pathophysiolology of psoriasis, psoriatic arthritis, rheumatoid arthritis. Knowing that the high dilution of substances can have an inverted effect, our hypotesis was that dillution made of TNF-alfa can decrease the clinical manifestation of such diseases. Materials and method: We included as a pilot group 10 patients presented in Lotus Life Integrative Medicine Center or Profamilia Medical Center Iasi with psoriasis and rheumatoid arthritis previously diagnosed by specialists, under speciality treatment with insufficient results and patients who deliberately expressed their preference for alternative treatment. We decided to exclude the patients which during the study could present aggravation of symptoms. The treatment protocol consisted in the administration under the tongue of the dilution of TNF-alfa 9CH in liquid form, 12 drops twice a day for at least 3 months. This was prepared diluting from Guna TNF-alfa 4CH in distiled water, completing with 30% of alcohol in the last solution. Patients under other medications continued to take their previous treatment unchanged. We called the patients for follow-up after 3 months. We took the written consent from the patients and the approval of the Ethical Committee of the University of Medicine and Pharmacy "Gr. T. Popa" of Iasi. Results: To analize the results we followed the subjective evolution of the patients, the total surface and thickness of eruptions in psoriasis patients and the pain intensity and stiffness in arthritis patients. Under this conditions, all the patients showed amelioration, with 2 out of 6 psoriasis patients showing complete clearance of eruptions. No patient reported adverse reactions during the treatment Conclusions: Even though the group of patients was small and not appropriate for statistical data the presence of a clinical

  10. Expressão local do fator de necrose tumoral alfa na ruptura prematura de membranas

    OpenAIRE

    Roveran,Valquíria; SILVA, Maria Antonieta Longo Galvão; Yamano,Lucia; Rodrigues,Lilian de Paiva; Vasquez,Mônica Lopez; Piato, Sebastião

    2009-01-01

    OBJETIVO: comparar a expressão do fator de necrose tumoral alfa (TNF-α) em membranas ovulares com ruptura prematura (RPM) e com ruptura oportuna das mesmas; verificar a associação entre a expressão do TNF-α em membranas ovulares e o grau de corioamnionite das mesmas e correlacionar a expressão do TNF-α e o tempo de ruptura das membranas. MÉTODOS: foram analisadas as membranas ovulares de 31 parturientes com RPM, com idade gestacional acima de 34 semanas, e de 14 parturientes co...

  11. Factor de necrosis tumoral alfa en una población infanto-juvenil con sobrepeso

    OpenAIRE

    Teresita del R. Carrizo; Elba I. Díaz; María S. Velarde; María M. Prado; María C. Bazán; Abregú, Adela V.

    2013-01-01

    El sobrepeso infantil está asociado a sobrepeso/obesidad en la edad adulta. El tejido adiposo en obesos produce una cantidad incrementada de citoquinas proinflamatorias como el factor de necrosis tumoral alfa (TNF-a), ejerciendo un efecto deletéreo sobre la función vascular. El objetivo de este trabajo fue evaluar niveles de TNF-a en una población infantojuvenil con sobrepeso y su relación con otras variables. Se estudiaron 30 niños con sobrepeso (12 varones) de edades entre 8-13 años, se mid...

  12. Interferón alfa-2b tópico como primera opción en las neoplasias intraepiteliales corneoconjuntivales Topical interferon alfa-2b for primary treatment of conjunctiva-cornea intraepithelial neoplasia

    OpenAIRE

    M. Pérez de Arcelus; Aranguren, M.; J. Andonegui

    2012-01-01

    Se describen dos casos de neoplasia intraepitlelial corneo-conjuntival (CIN) tratados con interferón alfa-2b (IFN alfa-2b) tópico como primera elección. El tratamiento clásico de los CIN ha sido tradicionalmente la resección completa con márgenes de seguridad seguida de crioterapia en el lecho quirúrgico. No obstante, y puesto que la tasa de recidivas puede alcanzar el 50% han sido propuestos coadyuvantes como la mitomicina C y el 5 fluoracilo, con el consiguiente riesgo de toxicidad corneal ...

  13. Corifollitropin alfa followed by rFSH in a GnRH antagonist protocol for poor ovarian responder patients

    DEFF Research Database (Denmark)

    Polyzos, Nikolaos P; Devos, Michel; Humaidan, Peter;

    2013-01-01

    OBJECTIVE: To identify whether women with poor ovarian response may benefit from treatment with corifollitropin alfa in a GnRH antagonist protocol. DESIGN: Retrospective pilot study. SETTING: University-based tertiary care center. PATIENT(S): Poor ovarian responders fulfilling the Bologna criteria...... developed by European Society for Human Reproduction and Embryology Consensus Group. INTERVENTION(S): Corifollitropin alfa (150 μg) followed by 300 IU rFSH in a GnRH antagonist protocol. MAIN OUTCOME MEASURE(S): Endocrinologic profile and ongoing pregnancy rates. RESULT(S): Among 43 women treated...... compared with a cohort of patients treated during 2011 with the standard protocol for poor responders in our center (short agonist-hMG) (7% vs. 6.3%). CONCLUSION(S): Treatment of poor ovarian responders, as described by the Bologna criteria, with corifollitropin alfa in a GnRH antagonist protocol results...

  14. Mapping Hydrogen in the Galaxy, Galactic Halo, and Local Group with ALFA: The GALFA-HI Survey Starting with TOGS

    CERN Document Server

    Gibson, S J; Heiles, C; Korpela, E J; Peek, J E G; Putman, M E; Stanimirović, S

    2008-01-01

    Radio observations of gas in the Milky Way and Local Group are vital for understanding how galaxies function as systems. The unique sensitivity of Arecibo's 305m dish, coupled with the 7-beam Arecibo L-Band Feed Array (ALFA), provides an unparalleled tool for investigating the full range of interstellar phenomena traced by the HI 21cm line. The GALFA (Galactic ALFA) HI Survey is mapping the entire Arecibo sky over a velocity range of -700 to +700 km/s with 0.2 km/s velocity channels and an angular resolution of 3.4 arcminutes. We present highlights from the TOGS (Turn on GALFA Survey) portion of GALFA-HI, which is covering thousands of square degrees in commensal drift scan observations with the ALFALFA and AGES extragalactic ALFA surveys. This work is supported in part by the National Astronomy and Ionosphere Center, operated by Cornell University under cooperative agreement with the National Science Foundation.

  15. GSI Helmholz Centre for Heavy Ion Research - ALFA: Next generation concurrent framework for ALICE and FAIR experiments

    CERN Document Server

    CERN. Geneva

    2015-01-01

    FAIR is a new, unique international accelerator facility for the research with antiprotons and ions. It is being built at the GSI Darmstadt in Hesse, Germany. The commonalities between the ALICE and FAIR experiments and their computing requirements led to the development of a common software framework in an experiment independent way; ALFA (ALICE-FAIR framework). ALFA is designed for high quality parallel data processing and reconstruction on heterogeneous computing systems. It provides a data transport layer and the capability to coordinate multiple data processing components. ALFA is a flexible, elastic system which balances reliability and ease of development with performance by using a message based multi-processing in addition to multi-threading. The framework allows for usage of heterogeneous computing architectures by offloading (portions of code are accelerated on the device) or natively (where the full program is executed on the device ).

  16. Adjuvant therapy with pegylated interferon alfa-2b versus observation alone in resected stage III melanoma: final results of EORTC 18991, a randomised phase III trial.

    NARCIS (Netherlands)

    Eggermont, A.M.; Suciu, S.; Santinami, M.; Testori, A.; Kruit, W.H.; Marsden, J.; Punt, C.J.A.; Sales, F.; Gore, M.; Mackie, R.; Kusic, Z.; Dummer, R.; Hauschild, A.; Musat, E.; Spatz, A.; Keilholz, U.

    2008-01-01

    BACKGROUND: Any benefit of adjuvant interferon alfa-2b for melanoma could depend on dose and duration of treatment. Our aim was to determine whether pegylated interferon alfa-2b can facilitate prolonged exposure while maintaining tolerability. METHODS: 1256 patients with resected stage III melanoma

  17. Home infusion program for Fabry disease: experience with agalsidase alfa in Argentina Programa de infusión domiciliaria para la enfermedad de Fabry: experiencia con agalsidasa alfa en la Argentina

    Directory of Open Access Journals (Sweden)

    Isaac Kisinovsky

    2013-02-01

    Full Text Available Fabry disease is an X-linked lysosomal storage disorder caused by inherited deficiency of the enzyme α-galactosidase A. Enzyme replacement treatment using agalsidase alfa significantly reduces pain, improves cardiac function and quality of life, and slows renal deterioration. Nevertheless, it is a life-long treatment which requires regular intravenous infusions and entails a great burden for patients. Our objective was to evaluate retrospectively the safety and tolerability of the home infusion of agalsidase alfa in patients with Fabry disease in Argentina. We evaluated all the patients with Fabry disease who received home infusion with agalsidase alfa 0.2 mg/kg between January 2005 and June 2011. The program included 87 patients; 51 males (mean age: 30 years and 36 females (mean age: 34 years. A total of 5229 infusions (mean: 59 per patient; range: 1-150 were administered. A total of 5 adverse reactions were seen in 5 patients (5.7% of patients and 0.9% of the total number of infusions. All were mild in severity and resolved by reducing the rate of infusion and by using antihistaminics. All these 5 patients were positive for IgG antibodies, but none of them presented IgE antibodies and none suffered an anaphylactic shock. In our group 18 patients were switched from agalsidase beta to agalsidase alfa without complications. Home infusion with agalsidase alfa is safe, well tolerated and is associated to high compliance.La enfermedad de Fabry es un trastorno de almacenamiento lisosomal hereditario ligado al cromosoma X ocasionado por el déficit de la enzima alfa galactosidasa A. La terapia de reemplazo enzimático utilizando agalsidasa alfa reduce significativamente el dolor, mejora la función cardíaca y la calidad de vida y enlentece el deterioro renal. Sin embargo, es un tratamiento de por vida que requiere infusiones intravenosas regulares y supone una gran carga para los pacientes. Nuestro objetivo fue evaluar retrospectivamente la

  18. Side effects in melanoma patients receiving adjuvant interferon alfa-2b therapy: a nurse's perspective.

    Science.gov (United States)

    Rubin, Krista M; Vona, Karen; Madden, Kathleen; McGettigan, Suzanne; Braun, Ilana M

    2012-08-01

    The aim of this review was to examine the toxicity profile of adjuvant interferon (IFN) alfa-2b in melanoma patients from a nursing perspective and to summarize practical information to guide the effective management of common IFN toxicities to improve patient comfort. This is a narrative summary of both research and review articles identified by searching PubMed, National Cancer Institute, and American Cancer Society websites. It also assesses recognized guidelines on the management of adjuvant IFN toxicity relevant to nurses who are caring for patients receiving adjuvant IFN therapy. Adjuvant high-dose IFN alfa-2b (HDI) as compared with observation significantly prolongs relapse-free survival in patients with melanoma at high risk for recurrence after surgical resection; however, treatment compliance and patient quality of life can be compromised by its toxicity profile. HDI toxicities affect a number of organ systems and the majority of patients will experience some side effects. Common toxicities such as flu-like symptoms, fatigue, anorexia, neuropsychiatric symptoms, and laboratory abnormalities are discussed, along with both pharmacological and nonpharmacological management strategies. The considerable side effects of HDI can be managed using established strategies. Oncology nurses play a significant role in the management of patients with melanoma receiving adjuvant HDI, and their prompt recognition of side effects, together with an understanding of effective pharmacological and nonpharmacological interventions, will improve patient comfort; this has the potential to positively influence treatment adherence and completion of the recommended treatment course.

  19. FTIR spectroscopy and X-ray powder diffraction characterization of microcrystalline cellulose obtained from alfa fibers

    Directory of Open Access Journals (Sweden)

    Trache D.

    2013-07-01

    Full Text Available Many cereal straws have been used as raw materials for the preparation of microcrystalline cellulose (MCC. These raw materials were gradually replaced with wood products; nevertheless about 10% of the world overall pulp production is obtained from non-wood raw material. The main interest in pulp made from straw is that it provides excellent fibres for different industries with special properties, and that it is the major available source of fibrous raw material in some geographical areas. The aim of the present work was to characterize microcrystalline cellulose prepared from alfa fibers using the hydrolysis process. The products obtained are characterized with FTIR spectroscopy and X-ray powder diffraction. As a result, FTIR spectroscopy is an appropriate technique for studying changes occurred by any chemical treatment. The spectrum of alfa grass stems shows the presence of lignin and hemicelluloses. However, the cellulose spectrum indicates that the extraction of lignin and hemicellulose was effective. The X-ray analysis indicates that the microcrystalline cellulose is more crystalline than the source material.

  20. De-squeeze the beams: the TOTEM and ATLAS/ALFA experiments

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

    A special week-long proton–proton run with larger beam sizes at the interaction point is intended to probe the p-p elastic scattering regime at small angles.   Nicola Turini, deputy spokesperson for TOTEM, in front of one of the experiment’s ‘Roman Pot’ detectors in the LHC tunnel. (Photo: Maximilien Brice/CERN) Usually, the motto of the LHC is “maximum luminosity”. But for a few days per year, the LHC ignores its motto to run at very low luminosity for the forward experiments. This week, the LHC will provide the TOTEM and ATLAS/ALFA experiments with data for a broad physics programme. The TOTEM experiment at Point 5 and the ATLAS/ALFA experiment at Point 1 study the elastic scattering of protons, which are not observable in normal operation runs. In the elastic scattering process, the two protons survive their encounter intact and only change directions by exchanging momentum. To allow this special run, the operators play with the so-c...

  1. Drotrecogin alfa (activated)...a sad final fizzle to a roller-coaster party.

    Science.gov (United States)

    Angus, Derek C

    2012-02-06

    Following the failure of PROWESS-SHOCK to demonstrate efficacy, Eli Lilly and Company withdrew drotrecogin alfa (activated) from the worldwide market. Drotrecogin was initially approved after the original trial, PROWESS, was stopped early for overwhelming efficacy. These events prompt consideration of both the initial approval decision and the later decision to withdraw. It is regrettable that the initial decision was made largely on a single trial that was stopped early. However, the decision to approve was within the bounds of normal regulatory practice and was made by many approval bodies around the world. Furthermore, the overall withdrawal rate of approved drugs remains very low. The decision to withdraw was a voluntary decision by Eli Lilly and Company and likely reflected key business considerations. Drotrecogin does have important biologic effects, and it is probable that we do not know how best to select patients who would benefit. Overall, there may still be a small advantage to drotrecogin alfa, even used non-selectively, but the costs of determining such an effect with adequate certainty are likely prohibitive, and the point is now moot. In the future, we should consider ways to make clinical trials easier and quicker so that more information can be available in a timely manner when considering regulatory approval. At the same time, more sophisticated selection of patients seems key if we are to most wisely test agents designed to manipulate the septic host response.

  2. Papel de la IL-6 y TNF-alfa en la enfermedad periodontal

    Directory of Open Access Journals (Sweden)

    A. Carrillo de Albornoz Sainz

    Full Text Available La periodontitis se inicia por una serie de patógenos que inducen una cascada inflamatoria que estimula la destrucción de los tejidos mediada por el huésped. Están implicados un gran número de mediadores inflamatorios, entre los que destacan IL-6 y TNF-alfa. La IL-6 es una citoquina pleiotrópica de compleja actividad biológica, cuya función principal vinculada a la periodontitis es la inducción de la reabsorción ósea. TNF-alfa es una citoquina proinflamatoria cuya función más destacada es el reclutamiento y estimulación de neutrófilos y monocitos. Su papel en la periodontitis es diverso, ya que promueve tanto la inflamación, como la pérdida ósea y la destrucción del tejido conectivo, a la vez que limita la capacidad de reparación del periodonto.

  3. Mango resistance to fruit flies. II - resistance of the alfa cultivar

    Energy Technology Data Exchange (ETDEWEB)

    Rossetto, C.J.; Bortoletto, N., E-mail: rossetto@iac.sp.gov.b [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Votuporanga, SP (Brazil). Polo Regional do Noroeste Paulista; Walder, J.M.M.; Mastrangelo, T. de A., E-mail: jmwalder@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Carvalho, C.R.L.; Castro, J.V. de, E-mail: climonta@iac.sp.gov.b, E-mail: josalba@iac.sp.gov.b [Instituto Agronomico de Campinas, SP (Brazil); Pinto, A.C. de Q. [EMBRAPA, Brasilia, DF (Brazil); Cortelazzo, A.L., E-mail: angelo@unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Biologia

    2006-07-01

    The percentage of infested mango fruits of five selected mango varieties was evaluated during three years under field conditions. Three varieties with field resistance to fruit flies had less then 10% of fruits infested. Tommy Atkins, the susceptible commercial check, had 42,9% and the susceptible check had 98.9 % of infested fruits. The three field resistant varieties plus the susceptible commercial check, Tommy Atkins, were further tested in laboratory, under caged conditions, with artificial infestation of Anastrepha obliqua. The attempts of oviposition and the number of pupae developed from each fruit were evaluated. Under caged conditions, the cultivar Alfa maintained its field resistance and Espada Stahl and IAC 111 lost the field resistance and were as susceptible as Tommy Atkins. The attempts of oviposition were positively and highly correlated with the number of pupae developed in the fruits. Non preference for oviposition was confirmed as the main mechanism of resistance of mango fruits to fruit flies. In the absence of a more susceptible variety (no choice test) the cultivar Alfa has kept the resistance (author)

  4. Interferon alfa-2a versus combination therapy with interferon alfa-2a, interleukin-2, and fluorouracil in patients with untreated metastatic renal cell carcinoma (MRC RE04/EORTC GU 30012): an open-label randomised trial.

    NARCIS (Netherlands)

    Gore, M.E.; Griffin, C.L.; Hancock, B.; Patel, P.M.; Pyle, L.; Aitchison, M.; James, N.; Oliver, R.T.D.; Mardiak, J.; Hussain, T.; Sylvester, R.; Parmar, M.K.; Royston, P.; Mulders, P.F.A.

    2010-01-01

    BACKGROUND: In metastatic renal cell carcinoma combinations of interferon alfa-2a, interleukin-2, and fluorouracil produce higher response rates and longer progression-free survival than do single agents. We aimed to compare overall survival in patients receiving combination treatment or interferon

  5. Interferon alfa-2a versus combination therapy with interferon alfa-2a, interleukin-2, and fluorouracil in patients with untreated metastatic renal cell carcinoma (MRC RE04/EORTC GU 30012): an open-label randomised trial.

    NARCIS (Netherlands)

    Gore, M.E.; Griffin, C.L.; Hancock, B.; Patel, P.M.; Pyle, L.; Aitchison, M.; James, N.; Oliver, R.T.D.; Mardiak, J.; Hussain, T.; Sylvester, R.; Parmar, M.K.; Royston, P.; Mulders, P.F.A.

    2010-01-01

    BACKGROUND: In metastatic renal cell carcinoma combinations of interferon alfa-2a, interleukin-2, and fluorouracil produce higher response rates and longer progression-free survival than do single agents. We aimed to compare overall survival in patients receiving combination treatment or interferon

  6. The Arecibo Legacy Fast ALFA Survey : X. The HI Mass Function and Omega_HI From the 40% ALFALFA Survey

    NARCIS (Netherlands)

    Martin, Ann M.; Papastergis, Emmanouil; Giovanelli, Riccardo; Haynes, Martha P.; Springob, Christopher M.; Stierwalt, Sabrina

    2010-01-01

    The Arecibo Legacy Fast ALFA (ALFALFA) survey has completed source extraction for 40% of its total sky area, resulting in the largest sample of HI-selected galaxies to date. We measure the HI mass function from a sample of 10,119 galaxies with 6.2

  7. Accurate Learning with Few Atlases (ALFA): an algorithm for MRI neonatal brain extraction and comparison with 11 publicly available methods

    Science.gov (United States)

    Serag, Ahmed; Blesa, Manuel; Moore, Emma J.; Pataky, Rozalia; Sparrow, Sarah A.; Wilkinson, A. G.; MacNaught, Gillian; Semple, Scott I.; Boardman, James P.

    2016-03-01

    Accurate whole-brain segmentation, or brain extraction, of magnetic resonance imaging (MRI) is a critical first step in most neuroimage analysis pipelines. The majority of brain extraction algorithms have been developed and evaluated for adult data and their validity for neonatal brain extraction, which presents age-specific challenges for this task, has not been established. We developed a novel method for brain extraction of multi-modal neonatal brain MR images, named ALFA (Accurate Learning with Few Atlases). The method uses a new sparsity-based atlas selection strategy that requires a very limited number of atlases ‘uniformly’ distributed in the low-dimensional data space, combined with a machine learning based label fusion technique. The performance of the method for brain extraction from multi-modal data of 50 newborns is evaluated and compared with results obtained using eleven publicly available brain extraction methods. ALFA outperformed the eleven compared methods providing robust and accurate brain extraction results across different modalities. As ALFA can learn from partially labelled datasets, it can be used to segment large-scale datasets efficiently. ALFA could also be applied to other imaging modalities and other stages across the life course.

  8. Daclatasvir plus peginterferon alfa and ribavirin for treatment-naive chronic hepatitis C genotype 1 or 4 infection

    DEFF Research Database (Denmark)

    Hézode, Christophe; Hirschfield, Gideon M; Ghesquiere, Wayne

    2015-01-01

    OBJECTIVE: To evaluate the safety and efficacy of daclatasvir, an HCV NS5A inhibitor with pangenotypic activity, administered with peginterferon-alfa-2a/ribavirin. DESIGN: In this Phase 2b double-blind, placebo-controlled study, treatment-naive adults with HCV genotype 1 (N=365) or 4 (N=30) infec...

  9. Il trattamento di pazienti con sepsi grave mediante drotrecogin alfa: una valutazione economica con riferimento all’Italia

    Directory of Open Access Journals (Sweden)

    Carlo Lucioni

    2002-09-01

    Full Text Available Sepsis can be defined as a spectrum of clinical conditions caused by the immune response of a host to infection or trauma and characterized by systemic inflammation and coagulation. Particularly in elderly, immunocompromised and critically ill patients, sepsis is a major cause of morbidity and mortality in intensive care units (ICUs worldwide. In the US, sepsis is the leading cause of death in noncoronary ICU patients. Drotrecogin alfa, or recombinant human activated protein C, has antithrombotic, antiinflammatory, and profibrinolytic properties. Recently in a phase III trial (PROWESS, Drotrecogin alfa demonstrated significantly reduced mortality in severe sepsis patients at 28 days. In this trial important value factors for the assessment of costs and outcomes of severe sepsis were also considered. The purpose of the present study is to determine the economic burden of the treatment with Drotrecogin alfa, according to a cost-effectiveness analysis based on the data of the PROWESS trial. The study has been adapted to the italian health environment. As regards to the costs per surviving patient and costs per QALY (Quality Adjusted Life Year, the predicted cost-effectiveness ratio of drotrecogin alfa in severe sepsis patients is much lower than the standard values considered as acceptable in the international litterature.

  10. Comprehensive safety analysis of concomitant drotrecogin alfa (activated) and prophylactic heparin use in patients with severe sepsis

    NARCIS (Netherlands)

    M. Levy; M. Levi; M.D. Williams; M. Antonelli; D. Wang; M.A. Mignini

    2009-01-01

    Purpose: The safety of using heparin concomitantly with drotrecogin alfa (activated) {DrotAA} was explored in the XPRESS study. No heparin effect on mortality was observed. Safety results from that study are explored in more detail. Methods: A randomized, double-blind trial of prophylactic heparin v

  11. The Arecibo Legacy Fast ALFA Survey : X. The HI Mass Function and Omega_HI From the 40% ALFALFA Survey

    NARCIS (Netherlands)

    Martin, Ann M.; Papastergis, Emmanouil; Giovanelli, Riccardo; Haynes, Martha P.; Springob, Christopher M.; Stierwalt, Sabrina

    2010-01-01

    The Arecibo Legacy Fast ALFA (ALFALFA) survey has completed source extraction for 40% of its total sky area, resulting in the largest sample of HI-selected galaxies to date. We measure the HI mass function from a sample of 10,119 galaxies with 6.2

  12. Benefit of adjuvant interferon alfa-2b (IFN-α) therapy in melanoma patients with high serum MMP-8 levels

    DEFF Research Database (Denmark)

    Vihinen, Pia; Tervahartiala, Taina; Sorsa, Timo

    2015-01-01

    Matrix metalloproteinases (MMPs) are important enzymes in tissue turnover and various inflammatory processes. In this study, it was evaluated whether serum MMP-8 can predict the response to adjuvant interferon alfa-2b (IFN-α) therapy in patients with operated high-risk cutaneous melanoma. Pre...

  13. Molecular design and downstream processing of turoctocog alfa (NovoEight), a B-domain truncated factor VIII molecule.

    Science.gov (United States)

    Ahmadian, Haleh; Hansen, Ernst B; Faber, Johan H; Sejergaard, Lars; Karlsson, Johan; Bolt, Gert; Hansen, Jens J; Thim, Lars

    2016-07-01

    Turoctocog alfa (NovoEight) is a third-generation recombinant factor VIII (rFVIII) with a truncated B-domain that is manufactured in Chinese hamster ovary cells. No human or animal-derived materials are used in the process. The aim of this study is to describe the molecular design and purification process for turoctocog alfa. A five-step purification process is applied to turoctocog alfa: protein capture on mixed-mode resin; immunoaffinity chromatography using a unique, recombinantly produced anti-FVIII mAb; anion exchange chromatography; nanofiltration and size exclusion chromatography. This process enabled reduction of impurities such as host cell proteins (HCPs) and high molecular weight proteins (HMWPs) to a very low level. The immunoaffinity step is very important for the removal of FVIII-related degradation products. Manufacturing scale data shown in this article confirmed the robustness of the purification process and a reliable and consistent reduction of the impurities. The contribution of each step to the final product purity is described and shown for three manufacturing batches. Turoctocog alfa, a third-generation B-domain truncated rFVIII product is manufactured in Chinese hamster ovary cells without the use of animal or human-derived proteins. The five-step purification process results in a homogenous, highly purified rFVIII product.

  14. alfa-Deuterium kinetic isotope effects in reactions of methyllithium. Is better aggregation the cause of lower reactivity?

    DEFF Research Database (Denmark)

    Holm, Torkil

    1996-01-01

    The value of kH/kD for alfa deuterium kinetic isotope effects for the reaction of methyllithium and methylmagnesium iodid with a series of substrates are consistently ca. 10-15 % higher for the lithium reagent. This may indicate a pre-equilibrium...

  15. Randomized, controlled, open-label, non-inferiority study of the CONSORT algorithm for individualized dosing of follitropin alfa

    NARCIS (Netherlands)

    Olivennes, F.; Trew, G.; Borini, A.; Broekmans, F.; Arriagada, P.; Warne, D. W.; Howles, C. M.

    2015-01-01

    In this randomized, controlled, open-label, phase IV study, ovarian response after a follitropin alfa starting dose determined by the CONSORT calculator was compared with a standard dose (150 IU). Normo-ovulatory women (aged 18-34 years) eligible for assisted reproductive techniques were recruited (

  16. Dificuldades na identificação laboratorial da talassemia alfa Difficulty on laboratory identification of alpha thalassemia

    Directory of Open Access Journals (Sweden)

    Karlla Greick Batista Dias-Penna

    2010-04-01

    Full Text Available Introdução: Talassemia alfa é uma síndrome associada à redução da síntese de cadeias de globina do tipo alfa. A gravidade das manifestações clínicas está relacionada com a quantidade de globinas produzida e a estabilidade das cadeias beta presentes em excesso. A talassemia alfa mínima resulta da deleção de apenas um dos quatro genes a (-α/αα. Clinicamente apresenta anemia leve com microcitose ou ausência de anemia, sendo o diagnóstico realizado por meio de visualização da hemoglobina (Hb H por eletroforese alcalina em acetato de celulose ou por identificação de inclusões celulares de Hb H coradas pelo azul de crezil brilhante. Objetivo: Avaliar portadores de talassemia alfa e seus respectivos progenitores, correlacionando perfil hematológico e presença de Hb H, utilizando procedimentos laboratoriais clássicos em três diferentes amostragens. Discussão e conclusão: Os dados obtidos mostram que a presença de Hb H, indicativo de talassemia alfa, pode não ser confirmada em uma análise posterior. Entre os fatores que podem influenciar no não aparecimento de Hb H em pessoa comprovadamente com talassemia alfa está a deficiência de ferro. A talassemia alfa está associada a defeitos envolvendo os genes codificadores da cadeia alfa, mas também pode estar relacionada com desbalanciamento temporário na expressão dos genes globina, diminuição de alfa ou aumento de beta, o que poderia explicar o aparecimento de tetrâmeros de cadeia beta (Hb H, sugerindo diagnóstico de talassemia alfa mínima.Introduction: Alpha thalassemia is a syndrome with associated with the reduction of alpha globin chain synthesis. The severity of clinical manifestations is related to the amount of globins produced and the stability of beta chains that are present in excess. Alpha thalassemia minor is caused by the deletion of one of the four genes a (-α/αα. Clinically, it presents mild anemia with microcytosis or absence of anemia. The

  17. Pegylated interferon alfa-2b plus ribavirin for treatment of chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    PN; Rao; Abraham; Koshy; Jacob; Philip; Narayanan; Premaletha; Joy; Varghese; Krishnasamy; Narayanasamy; Samir; Mohindra; Nitin; Vikas; Pai; Manoj; Kumar; Agarwal; Ashokna; Konar; Hasmukh; B; Vora

    2014-01-01

    AIM: To study the safety and efficacy of pegylated interferon alfa-2b, indigenously developed in India, plus ribavirin in treatment of hepatitis C virus(HCV). METHODS: One-hundred HCV patients were enrolled in an open-label, multicenter trial. Patients were treated with pegylated interferon alfa-2b 1.5 μg/kg per week subcutaneously plus oral ribavirin 800 mg/d for patients with genotypes 2 and 3 for 24 wk. The same dose of peginterferon plus weight-based ribavirin(800 mg/d for ≤ 65 kg; 1000 mg/d for > 65-85 kg; 1200 mg/d for > 85-105 kg; 1400 mg/d for > 105 kg body weight) was administered for 48 wk for patients with genotypes 1 and 4. Serological and biochemical responses of patients were assessed.RESULTS: Eighty-two patients(35 in genotypes 1 and 4 and 47 in 2 and 3), completed the study. In genotype 1, 25.9% of patients achieved rapid virologic response(RVR): while the figures were 74.1% for early virologic response(EVR) and 44.4% for sustained virologic response(SVR). For genotypes 2 and 3, all patients bar one belonged to genotype 3, and of those, 71.4%, 87.5%, and 64.3% achieved RVR, EVR, and SVR, respectively. In genotype 4, 58.8%, 88.2%, and 52.9% of patients achieved RVR, EVR, and SVR, respectively. The majority of patients attained normal levels of alanine aminotransferase by 4-12 wk of therapy. Most patients showed a good tolerance for the treatment, although mild-to-moderate adverse events were exhibited; only two patients discontinued the study medication due to serious adverse events(SAEs). Eleven SAEs were observed in nine patients; however, only four SAEs were related to study medication.CONCLUSION: Peginterferon alfa-2b, which was developed in India, in combination with ribavirin, is a safe and effective drug in the treatment of HCV.

  18. The ATLAS Forward Detectors - LUCID, ALFA and AFP: Past, Present and Future

    CERN Document Server

    Caforio, D; The ATLAS collaboration

    2013-01-01

    LUCID is a gas Cerenkov detector deployed near to the beam‐pipe at 17 m either side of the ATLAS Intersection point. The LUCID detector ‐ when calibrated via a Van der Meer scan – is now measuring absolute luminosity on a bunch‐by‐bunch basis. It is now measuring integrated luminosity up to high luminosity with a precision of around 3%. The technical challenges that had to faced to make this measurement as well as upgrade plans for LUCID will be presented. In addition to LUCID, we will discuss that ALFA detector (Absolute Luminosity for ATLAS) and its status as well as the progress on the ATLAS Forward Protons project (AFP) that plans to deploy detectors to tag and measure, with 3‐D silicon detectors, both protons in exclusive central diffractive processes.

  19. HI Clouds detected towards Virgo with the Arecibo Legacy Fast ALFA Survey

    CERN Document Server

    Kent, Brian R

    2007-01-01

    The Arecibo Legacy Fast ALFA survey is in the process of yielding a complete HI dataset of the Virgo Cluster and its environs (Giovanelli et al. 2007, Kent et al., in preparation). Assuming a distance to Virgo of 16.7 Mpc, the minimum detectable HI mass by ALFALFA is of order 2 x 10^7 Msun. A number of the HI detections appear to have interesting properties. Some appear associated with, but offset from, low surface brightness optical counterparts; others, at larger spatial offsets, may be tidally related to optical counterparts. Yet another class includes detections which are not identifiable with any optical counterparts. We present the ALFALFA results on these objects in the Virgo region, as well as followup aperture synthesis observations obtained with the VLA.

  20. A trial of darbepoetin alfa in type 2 diabetes and chronic kidney disease

    DEFF Research Database (Denmark)

    Pfeffer, Marc A; Burdmann, Emmanuel A; Chen, Chao-Yin

    2009-01-01

    BACKGROUND: Anemia is associated with an increased risk of cardiovascular and renal events among patients with type 2 diabetes and chronic kidney disease. Although darbepoetin alfa can effectively increase hemoglobin levels, its effect on clinical outcomes in these patients has not been adequately...... level was less than 9.0 g per deciliter. The primary end points were the composite outcomes of death or a cardiovascular event (nonfatal myocardial infarction, congestive heart failure, stroke, or hospitalization for myocardial ischemia) and of death or end-stage renal disease. RESULTS: Death......, and moderate anemia who were not undergoing dialysis did not reduce the risk of either of the two primary composite outcomes (either death or a cardiovascular event or death or a renal event) and was associated with an increased risk of stroke. For many persons involved in clinical decision making, this risk...

  1. ALGLUCOSIDASE ALFA — A NEW STAGE IN THE THERAPY OF INFANTILE POMPE DISEASE

    Directory of Open Access Journals (Sweden)

    E. N. Basargina

    2014-01-01

    Full Text Available Pompe disease is a rare severe hereditary disease caused by excessive glycogen storage in organs and target tissues due to the acid α-glucosidase gene mutation. Infantile and adult Pompe disease is characterized by involvement of cardiovascular, respiratory and muscular systems in the pathological process. The only specific method of treating Pompe disease is enzyme replacement therapy (intravenous administration of recombinant human acid glucosidase, the effectiveness whereof depends on the time the therapy started. Since such a therapy was introduced into practice, Pompe disease mortality decreased by 79%. 6 children with infantile Pompe disease were observed and treated at the cardiovascular care unit of the Scientific Center of Children’s Health in 2011‑2014. The article presents a clinical case demonstrating capabilities of diagnosing infantile Pompe disease in Russia and effective application of alglucosidase alfa in 4-month-old child. 

  2. Analise dos alelos S e Z da alfa 1 antitripsina em uma amostra de pacientes fibrocisticos

    OpenAIRE

    2002-01-01

    A fibrose cística é uma alteração genética que cursa principalmente com manifestações pulmonares e pancreáticas. A correlação genótipo-fenótipo da fibrose cística é motivo de árduos estudos. Somente a correlação com a insuficiência pancreática foi encontrada. Percebeu-se, também, que o curso e a severidade da manifestação pulmonar não estão correlacionados com o genótipo CFTR. A alfaI antitripsina inibe as proteases que desencadeiam as reações inflamatórias do plasma. Seu papel inibitório mai...

  3. Arecibo Pulsar Survey Using ALFA. III. Probing Radio Pulsar Intermittency and Transients

    CERN Document Server

    Deneva, J S; McLaughlin, M A; Nice, D J; Lorimer, D R; Crawford, F; Bhat, N D R; Camilo, F; Champion, D J; Freire, P C C; Edel, S; Kondratiev, V I; Hessels, J W T; Jenet, F A; Kasian, L; Kaspi, V M; Krämer, M; Lazarus, P; Van Leeuwen, J; Ransom, S M; Stairs, I H; Stappers, B W; Brazier, A; Venkataraman, A; Zollweg, J A

    2008-01-01

    We present radio transient search algorithms, results, and statistics from the ongoing Arecibo Pulsar ALFA (PALFA) Survey of the Galactic plane. We have discovered seven objects by detecting isolated dispersed pulses and one of the new discoveries has a duty cycle of 0.01%, the smallest known. The impact of selection effects on the detectability and classification of intermittent sources is discussed, and the relative efficiencies of periodicity vs. single pulse searches are compared for various pulsar classes. We find that scintillation, off-axis detection and few rotation periods within an observation may misrepresent normal periodic pulsars as intermittent sources. Finally, we derive constraints on transient pulse rate and flux density from the PALFA survey parameters and results.

  4. Efficacy and safety of peginterferon alfa-2a and ribavirin treatment of chronic hepatitis C in the Republic of Serbia

    Directory of Open Access Journals (Sweden)

    Božić Milena

    2012-01-01

    Full Text Available Introduction. Hepatitis C virus (HCV infection is one of the main causes of chronic liver disease worldwide. Pegylated interferon alfa-2a or 2b (PEG IFN alfa-2a or 2b and ribavirin (RBV represent a standard treatment of chronic hepatitis C (CHC. Sustained virological response (SVR, defined as continued undetectable HCV RNA 24 weeks after completion of treatment, is universally considered as an indicator of treatment efficacy. Objective. The aim of this study was to determine efficacy and safety of PEG IFN alfa-2a and RBV treatment in patients with CHC in Serbia. Methods. One hundred seventy-six patients with CHC were included in this multicenter trial from 8 reference centers in Serbia. The patients were treated with standard PEG IFN alfa- 2a and RBV protocol. We performed the following virological testing: anti-HCV (ELISA, HCV RNK (quantitative PCR, HCV genotype (type-specific PCR, HBsAg, anti-HBs, anti-HBc and anti-HIV (ELISA. Histological activity and the degree of fibrosis were determined according to the Metavir scoring system. Potential predictors for achieving SVR were evaluated using multivariable logistic regression analysis. Results. Of the treated patients with CHC 65.9% were male, and 60.2% of them aged over 40 years. Of the treated patients 68.2% had infection over 5 years, 63% had HCV RNA >400.000 IU/mL, 76.1% had HCV G1/4, and 60.1% had a mild to moderate liver fibrosis. SVR was achieved in 78.9% of patients (G1/4 79.1%; G2/3 78.1%. The factors that indicated a poorer efficacy of the treatment were age >40 (p<0.05, high basal viremia (p=0.013, and the reduction of PEG IFN alfa-2a and RBV doses, with interruption of therapy (p<0.001. Of the treated patients 45.9% had adverse affects (G1/4 50.8%; G2/3 29.7%. Conclusion. Treatment of CHC with PEG IFN alfa-2a and RBV was efficient in 78.9% of patients. The safety profile of therapy was satisfactory. Longer therapy increases the possibility of the development of adverse affects. No

  5. Propiedades electrofisiológicas de las variantes normales de actividad alfa en el continuo vigilia-sueño

    Directory of Open Access Journals (Sweden)

    José Luis Cantero

    2001-01-01

    Full Text Available El estudio de los ritmos cerebrales puede ser abordado mediante el análisis de sus propiedades electrofisiológicas usando técnicas de EEG cuantitativo. En aquellos casos donde una misma actividad aparece espontáneamente en diferentes estados de activación cerebral, el estudio de estas propiedades ayudaría a establecer diferencias funcionales asociadas a cada uno de estos estados. El presente trabajo revisa aquellos estudios que han determinado las propiedades electrofisiológicas de las diferentes variantes normales de alfa que aparecen en el continuo vigilia-sueño, más concretamente en vigilia relajada, somnolencia y durante la fase REM del sueño. Los resultados indican que cada variante normal de alfa, aun mostrando una distribución topográfica similar en cada uno de los estados cerebrales, presenta características diferenciales atendiendo a su composición espectral, relaciones funcionales entre regiones corticales, y micro-estados cerebrales subyacentes. De acuerdo con estos hallazgos, cada variante de alfa desempeñaría diferentes funciones cerebrales. El ritmo alfa de vigilia parece ser el resultado de una máxima sincronización neuronal como consecuencia de la ausencia de procesamiento sensorial, mientras que la presencia de actividad alfa durante la somnolencia estaría más asociada al procesamiento de las imágenes hipnagógicas que ocurren al comienzo del sueño. Los brotes de alfa de REM, sin embargo, constituirían un punto de contacto entre el cerebro dormido y el ambiente externo. Esta caracterización electrofisiológica encuentra su campo de aplicación más directo en el diseño de algoritmos para clasificar el sueño de forma automática, así como en el diagnóstico y evaluación de determinadas patologías donde pudieran verse afectados los mecanismos cerebrales de generación de esta actividad a lo largo del continuo vigilia-sueño.

  6. A Randomized Study of Peginterferon Lambda-1a Compared to Peginterferon Alfa-2a in Combination with Ribavirin and Telaprevir in Patients with Genotype-1 Chronic Hepatitis C

    Science.gov (United States)

    Flisiak, Robert; Shiffman, Mitchell; Arenas, Juan; Cheinquer, Hugo; Nikitin, Igor; Dong, Yuping; Rana, Khurram; Srinivasan, Subasree

    2016-01-01

    Background A randomized, double-blind, multinational, phase 3 study was conducted comparing the efficacy and safety of peginterferon lambda-1a (Lambda)/ribavirin (RBV)/telaprevir (TVR) vs. peginterferon alfa-2a (Alfa)/RBV/TVR in patients with chronic hepatitis C virus (HCV) genotype-1 (GT-1) infection. Methods Patients (treatment-naïve or relapsers on prior Alfa/RBV treatment) were randomly assigned in a 2:1 ratio to receive Lambda/RBV/TVR or Alfa/RBV/TVR. Total duration of treatment was either 24 or 48 weeks (response-guided treatment), with TVR administered for the first 12 weeks. The primary endpoint was the proportion of patients who achieved a sustained virologic response at post treatment week 12 (SVR12), which was tested for noninferiority of Lambda/RBV/TVR. Results A total of 838 patients were enrolled, and 617 were treated; 411 and 206 patients received Lambda/RBV/TVR and Alfa/RBV/TVR, respectively. The majority of patients were treatment-naïve, with HCV GT-1b and a high baseline viral load (≥800,000 IU/mL). Less than 10% of patients had cirrhosis (Lambda, 7.5%; Alfa, 6.8%). Lambda/RBV/TVR did not meet the criterion for noninferiority (lower bound of the treatment difference interval was -12.3%); the SVR12 in all patients (modified intent-to-treat) was 76.2% in the Lambda arm and 82.0% in the Alfa arm. Overall, the frequency of adverse events in each arm was comparable (Lambda, 91.7%; Alfa, 97.1%). As expected based on the safety profile of the 2 interferons, there were more hepatobiliary events observed in the Lambda arm and more hematologic events in the Alfa arm. Conclusions In this comparison of Lambda/RBV/TVR and Alfa/RBV/TVR in patients who were treatment-naïve or had relapsed on prior Alfa/RBV treatment, Lambda failed to demonstrate noninferiority based on SVR12 results. Treatment with Lambda/RBV/TVR was associated with a higher incidence of relapse. More patients discontinued Lambda/RBV/TVR treatment during the first 4 weeks of study treatment

  7. Pegylated Interferon Alfa-2b Monotherapy and Pegylated Interferon Alfa-2b plus Lamivudine Combination Therapy for Patients with Hepatitis B Virus E Antigen-Negative Chronic Hepatitis B▿

    Science.gov (United States)

    Kaymakoglu, Sabahattin; Oguz, Dilek; Gur, Gurden; Gurel, Selim; Tankurt, Ethem; Ersöz, Galip; Ozenirler, Seren; Kalayci, Cem; Poturoglu, Sule; Cakaloglu, Yılmaz; Okten, Atilla

    2007-01-01

    Forty-eight hepatitis B virus (HBV) E antigen-negative chronic hepatitis B patients received pegylated interferon alfa-2b either alone or with lamivudine for 48 weeks and were followed for an additional 24 weeks. At the end of follow-up, virological response rates (HBV DNA levels of <400 copies/ml) were similar in the monotherapy (24%) and combination therapy (26%) groups. PMID:17517832

  8. Evaluation of the efficacy and safety of three dosing regimens of agalsidase alfa enzyme replacement therapy was underpowered

    Directory of Open Access Journals (Sweden)

    Ortiz A

    2015-11-01

    Full Text Available Alberto Ortiz,1,2 Maria Dolores Sanchez-Niño1,2 1Department of Nephrology, IIS-Fundacion Jimenez Diaz, School of Medicine, Universidad Autónoma de Madrid, 2Department of Nephrology, Instituto Reina Sofia de Investigación Nefrológica, Madrid, Spain We read with interest the report by Goláň et al on the “Evaluation of the efficacy and safety of three dosing regimens of agalsidase alfa enzyme replacement therapy in adults with Fabry disease”.1 Based on the reported results, the authors conclude that no efficacy or safety differences were found when the approved every-other-week (EOW dosage of agalsidase alfa was increased to weekly administration. However, the key question is whether the study, as designed and performed, could have had a different outcome. View original article by Goláň et al.

  9. Deficiência de alfa-1-antitripsina na doença pulmonar obstrutiva crónica

    OpenAIRE

    2009-01-01

    Introdução – A deficiência de alfa-1-antitripsina é uma das alterações genéticas graves encontradas por todo o mundo. Porém, permanece subdiagnosticada, apesar da forte predisposição à doença pulmonar obstrutiva crónica que condiciona. Objectivos – Os objectivos deste artigo de revisão incluem o estudo e avaliação das implicações da deficiência de alfa-1-antitripsina em indivíduos com doença pulmonar obstrutiva crónica, a apresentação dos esquemas de diagnóstico e terapêuticos mais utiliza...

  10. Efek Pemberian Seduhan Teh Hijau terhadap Gelombang Alfa Otak pada Mahasiswa Tingkat Akhir Fakultas Kedokteran Universitas Islam Bandung

    Directory of Open Access Journals (Sweden)

    Helga Marwa Afifah

    2015-09-01

    Full Text Available Abstrak Teh merupakan bahan alam yang sudah dikenal memiliki banyak manfaat salah satunya sebagai zat relaksan. Sifat relaksan diperoleh dari kandungan senyawa pada teh terutama teh hijau yaitu L-teanin yang memicu peningkatan aktivitas gamma-aminobutyric acid (GABA, produksi serotonin dan dopamin, serta menghambat kerja glutamat. Efek keseluruhan L-teanin pada otak memicu seseorang menjadi rileks, kondisi rileks dapat dinilai dari aktivitas gelombang alfa otak. Tujuan penelitian ini menilai efek pemberian seduhan teh hijau terhadap gelombang alfa otak pada mahasiswa tingkat akhir Fakultas Kedokteran Unisba. Penelitian menggunakan metode eksperimental, melalui dua kali perekaman gelombang alfa otak sebelum dan setelah pemberian seduhan teh hijau yang mengandung 50 mg L-teanin dengan menggunakan brain wave sensors. Hasil penelitian dianalisis melalui Uji Wilcoxon. Penelitian dilakukan di Fakultas Kedokteran Unisba pada bulan April–Mei 2014. Sampel yang digunakan adalah mahasiswa tingkat akhir Fakultas Kedokteran Unisba yaitu sebanyak 30 orang, terdiri atas 13 laki-laki dan 17 perempuan. Hasil penelitian menunjukkan bahwa pada 28 dari 30 orang memperlihatkan peningkatan gelombang alfa otak setelah pemberian seduhan teh hijau dan hanya 2 orang yang memperlihatkan gelombang alfa otak yang lebih rendah. Hasil Uji Wilcoxon menunjukkan nilai signifikansi <0,001. Berdasarkan hasil penelitian, dapat disimpulkan bahwa pemberian seduhan teh hijau memiliki efek meningkatkan gelombang alfa otak pada mahasiswa tingkat akhir Fakultas Kedokteran Unisba. Hal ini dapat disebabkan karena aktivitas L-teanin dalam teh hijau yang dapat memicu aktivitas GABA, serotonin, dan dopamin serta menghambat kerja glutamat sehingga memicu kondisi relaksasi yang dinilai dalam gelombang alfa otak. Kata kunci: Gelombang alfa otak, L-teanin, teh, teh hijau   The Effect of Green Tea to Alpha Brain Waves of Final Students of Faculty of Medicine Universitas Islam Bandung Abstract

  11. Fe3O4/Au magnetic nanoparticle amplification strategies for ultrasensitive electrochemical immunoassay of alfa-fetoprotein

    Directory of Open Access Journals (Sweden)

    Gan N

    2011-12-01

    Full Text Available Ning Gan1*, Haijuan Jin1*, Tianhua Li1, Lei Zheng21The State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering, Ningbo University, Ningbo, 2Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China *Both authors contributed equally to this workBackground: The purpose of this study was to devise a novel electrochemical immunosensor for ultrasensitive detection of alfa-fetoprotein based on Fe3O4/Au nanoparticles as a carrier using a multienzyme amplification strategy.Methods and results: Greatly enhanced sensitivity was achieved using bioconjugates containing horseradish peroxidase (HRP and a secondary antibody (Ab2 linked to Fe3O4/Au nanoparticles (Fe3O4/Au-HRP-Ab2 at a high HRP/Ab2 ratio. After a sandwich immunoreaction, the Fe3O4/Au-HRP-Ab2 captured on the electrode surface produced an amplified electrocatalytic response by reduction of enzymatically oxidized hydroquinone in the presence of hydrogen peroxide. The high content of HRP in the Fe3O4/Au-HRP-Ab2 could greatly amplify the electrochemical signal. Under optimal conditions, the reduction current increased with increasing alfa-fetoprotein concentration in the sample, and exhibited a dynamic range of 0.005–10 ng/mL with a detection limit of 3 pg/mL.Conclusion: The amplified immunoassay developed in this work shows good precision, acceptable stability, and reproducibility, and can be used for detection of alfa-fetoprotein in real samples, so provides a potential alternative tool for detection of protein in the laboratory. Furthermore, this immunosensor could be regenerated by simply using an external magnetic field.Keywords: Fe3O4/Au nanoparticles, alfa-fetoprotein, sandwich immunoassay, electrochemical immunosensor

  12. Surface displaced alfa-enolase of Lactobacillus plantarum is a fibronectin binding protein

    Science.gov (United States)

    Castaldo, Cristiana; Vastano, Valeria; Siciliano, Rosa Anna; Candela, Marco; Vici, Manuela; Muscariello, Lidia; Marasco, Rosangela; Sacco, Margherita

    2009-01-01

    Background Lactic acid bacteria of the genus Lactobacillus and Bifidobacterium are one of the most important health promoting groups of the human intestinal microbiota. Their protective role within the gut consists in out competing invading pathogens for ecological niches and metabolic substrates. Among the features necessary to provide health benefits, commensal microorganisms must have the ability to adhere to human intestinal cells and consequently to colonize the gut. Studies on mechanisms mediating adhesion of lactobacilli to human intestinal cells showed that factors involved in the interaction vary mostly among different species and strains, mainly regarding interaction between bacterial adhesins and extracellular matrix or mucus proteins. We have investigated the adhesive properties of Lactobacillus plantarum, a member of the human microbiota of healthy individuals. Results We show the identification of a Lactobacillus plantarum LM3 cell surface protein (48 kDa), which specifically binds to human fibronectin (Fn), an extracellular matrix protein. By means of mass spectrometric analysis this protein was identified as the product of the L. plantarum enoA1 gene, coding the EnoA1 alfa-enolase. Surface localization of EnoA1 was proved by immune electron microscopy. In the mutant strain LM3-CC1, carrying the enoA1 null mutation, the 48 kDa adhesin was not anymore detectable neither by anti-enolase Western blot nor by Fn-overlay immunoblotting assay. Moreover, by an adhesion assay we show that LM3-CC1 cells bind to fibronectin-coated surfaces less efficiently than wild type cells, thus demonstrating the significance of the surface displaced EnoA1 protein for the L. plantarum LM3 adhesion to fibronectin. Conclusion Adhesion to host tissues represents a crucial early step in the colonization process of either pathogens or commensal bacteria. We demonstrated the involvement of the L. plantarum Eno A1 alfa-enolase in Fn-binding, by studying LM3 and LM3-CC1 surface

  13. Detection of DNA-recombinant human epoetin-alfa as a pharmacological ergogenic aid.

    Science.gov (United States)

    Wilber, Randall L

    2002-01-01

    The use of DNA-recombinant human epoetin-alfa (rhEPO) as a pharmacological ergogenic aid for the enhancement of aerobic performance is estimated to be practised by at least 3 to 7% of elite endurance sport athletes. rhEPO is synthesised from Chinese hamster ovary cells, and is nearly identical biochemically and immunologically to endogenous epoetin-alfa (EPO). In a clinical setting, rhEPO is used to stimulate erythrocyte production in patients with end-stage renal disease and anaemia. A limited number of human studies have suggested that rhEPO provides a significant erythropoietic and ergogenic benefit in trained individuals as evidenced by increments in haemoglobin, haematocrit, maximal oxygen uptake (VO2max) and exercise endurance time. The purpose of this review is to summarise the various technologies and methodologies currently available for the detection of illicit use of rhEPO in athletes. The International Olympic Committee (IOC) banned the use of rhEPO as an ergogenic aid in 1990. Since then a number of methods have been proposed as potential techniques for detecting the illegal use of rhEPO. Most of these techniques use indirect markers to detect rhEPO in blood samples. These indirect markers include macrocytic hypochromatic erythrocytes and serum soluble transferrin receptor (sTfr) concentration. Another indirect technique uses a combination of 5 markers of enhanced erythropoiesis (haematocrit, reticulocyte haematocrit, percentage of macrocytic red blood cells, serum EPO, sTfr) to detect rhEPO. The electrophoretic mobility technique provides a direct measurement of urine and serum levels of rhEPO, and is based on the principle that the rhEPO molecule is less negatively charged versus the endogenous EPO molecule. Isoelectric patterning/focusing has emerged recently as a potential method for the direct analysis of rhEPO in urine. Among these various methodologies, the indirect technique that utilises multiple markers of enhanced erythropoiesis appears to

  14. The oxidation of methionine-54 of epoetinum alfa does not affect molecular structure or stability, but does decrease biological activity.

    Science.gov (United States)

    Labrenz, Steven R; Calmann, Melissa A; Heavner, George A; Tolman, Glen

    2008-01-01

    Erythropoietin therapy is used to treat severe anemia in renal failure and chemotherapy patients. One of these therapies based on recombinant human erythropoietin is marketed under the trade name of EPREX and utilizes epoetinum alfa as the active pharmaceutical ingredient. The effect of oxidation of methionine-54 on the structure and stability of the erythropoietin molecule has not been directly tested. We have observed partial and full chemical oxidation of methionine-54 to methionine-54 sulfoxide, accomplished using tert-Butylhydroperoxide and hydrogen peroxide, respectively. A blue shift in the fluorescence center of spectral mass wavelength was observed as a linear response to the level of methionine sulfoxide in the epoetinum alfa molecule, presumably arising from a local change in the environment near tryptophan-51, as supported by potassium iodide quenching studies. Circular dichroism studies demonstrated no change in the folded structure of the molecule with methionine oxidation. The thermal unfolding profiles of partial and completely oxidized epoetinum alfa overlap, with a T(m) of 49.5 degrees C across all levels of methionine sulfoxide content. When the protein was tested for activity, a decrease in biological activity was observed, correlating with methionine sulfoxide levels. An allosteric effect between Met54, Trp51, and residues involved in receptor binding is proposed. These results indicate that methionine oxidation has no effect on the folded structure and global thermodynamic stability of the recombinant human erythropoietin molecule. Oxidation can affect potency, but only at levels significantly in excess of those seen in EPREX.

  15. [TNF-alfa (-857C/T) polymorphism in open angle glaucoma in Romania -- results of a pilot study].

    Science.gov (United States)

    Simionescu, Ruxandra; Voinea, Liliana; Cornăţeanu, Roxana Sfrenţ

    2013-01-01

    Primary open angle glaucoma is a progressive optic neuropathy with multiple causative factors including genetic immune disregulation. TNF-alfa has pro-apoptotic effects on the retinal ganglion cells, thus being directly involved in the neurodegeneration of the optic nerve head. Our purpose was to investigate the influence on susceptibility and/or clinical and characteristics of TNF-alfa promoter polymorphism -857 C/T in Romanian patients diagnosed with POAG. We assessed 159 Romanian subjects, 61 diagnosed with glaucoma (F/M 39/22) and 98 healthy unrelated matched controls-HC for the polymorphism -857 C/T, genotyped by Real Time PCR (Taqman SNP Genotyping Assay C_2215707_10, Applied Biosystems, USA). The diagnosis and the staging of the disease in the POAG group were assessed using the current guidelines. Association tests for the SNP were performed using SPSS 11.2 (Fisher test) and p values < or = 0.05 were considered significant. The Hardy-Weinberg equilibrium assessed using Chi-square test was respected in both studied groups- POAG and HC (p = 0.000009 and respectively p = 0.04771). There was no association found between the frequencies of alleles between studied groups (CC/CT/TT= 0.81/0.09/0.08 respectively 0.70/0.23/0.06). TNF-alfa promoter polymorphism -857 C/T doesn't seem to influence the susceptibility to POAG and the results should be confirmed on larger cohorts.

  16. Assessment of Lifespan Functioning Attainment (ALFA) scale: A quantitative interview for self-reported current and functional decline in schizophrenia.

    Science.gov (United States)

    Joseph, Jamie; Kremen, William S; Glatt, Stephen J; Franz, Carol E; Chandler, Sharon D; Liu, Xiaohua; Johnson, Barbara K; Tsuang, Ming T; Twamley, Elizabeth W

    2015-06-01

    Schizophrenia has been characterized as a disorder with poor outcomes across various functional domains, especially social and occupational functioning. Although these outcomes have been investigated based on patients' current functioning, few studies have considered the assessment of functional outcomes across the lifespan in schizophrenia. We developed a novel and brief scale of adulthood lifespan functioning, the Assessment of Lifespan Functioning Attainment (ALFA). We assessed current functioning and percentage of pre- and post-psychosis onset engagement for five functional domains including paid employment, living independently, romantic partnerships, close friendships, and recreational engagement with others. Pre-to post-psychosis functional decline was observed for all domains, with paid employment having the greatest decline (d = 2.68) and living independently having the least decline (d = .59). Our exploratory factor analysis suggests that a single factor accounted for the most variance in Pre-Psychosis Functioning in ALFA domains. Two factors explain the majority of variance in Post-Psychosis Functioning and Pre-to-Post Psychosis Decline: a sociability factor (close friendships and recreational engagement with others) and an independence factor (paid employment, living independently, romantic relationships). To our knowledge, this is the first study to report on a self-reported quantitative assessment of adult lifespan functioning in schizophrenia. The ALFA scale may be a useful tool for future research on functional outcomes in schizophrenia.

  17. Tungsten-induced denaturation and aggregation of epoetin alfa during primary packaging as a cause of immunogenicity.

    Science.gov (United States)

    Seidl, Andreas; Hainzl, Otmar; Richter, Marleen; Fischer, Robert; Böhm, Stephan; Deutel, Britta; Hartinger, Martin; Windisch, Jörg; Casadevall, Nicole; London, Gerard Michel; Macdougall, Iain

    2012-06-01

    Following two cases of neutralizing antibodies to epoetin alfa in an investigational clinical study, a small number of individual syringes of two drug product batches were found to contain unusually high levels of aggregation at the end of the clinical trial. We undertook an extensive analytical approach to determine the root-cause of the increased aggregation in the affected batches. Soluble tungsten was found in the syringes, most likely derived from the pins used to manufacture the syringes. Spiking of epoetin alfa with sodium polytungstate or an extract of tungsten pins used to manufacture the syringes induced the formation of aggregates, both dimers that appeared to be covalently linked by disulphide bonds as well as higher-order aggregates. Sodium polytungstate had also a strong denaturing effect on the protein. We propose tungsten-mediated unfolding and aggregation of epoetin alfa in pre-filled syringes as a potential root cause for increased immunogenicity. This finding may be more broadly applicable to this and other classes of therapeutic proteins.

  18. Pharmacokinetics of Novel Plant Cell-Expressed Taliglucerase Alfa in Adult and Pediatric Patients with Gaucher Disease.

    Directory of Open Access Journals (Sweden)

    Richat Abbas

    Full Text Available Taliglucerase alfa is a beta-glucocerebrosidase enzyme replacement therapy approved in the United States, Israel, and other countries for treatment of Type 1 Gaucher disease in adults, and is the first approved plant cell--expressed recombinant protein. In this report, taliglucerase alfa pharmacokinetics were assessed in adult and pediatric patients with Gaucher disease from separate multicenter trials of 30 Units/kg and 60 Units/kg doses infused every 2 weeks. Serial blood samples were obtained from adult patients following single-dose administration on day 1 (n = 26 and multiple doses at week 38 (n = 29, and from pediatric patients following administration of multiple doses of taliglucerase alfa for 10-27 months (n = 10. In both adult and pediatric patients, maximum plasma concentration (Cmax, area under the plasma concentration-time curve from time zero to last measureable concentration (AUC0-t, and from time zero to infinity (AUC0-∞ were higher after 60 Units/kg dose than 30 Units/kg dose. No tendency for accumulation or change in taliglucerase alfa pharmacokinetic parameters over time from day 1 to week 38 was observed with repeated doses of 30 or 60 Units/kg in adults. After multiple doses, mean (range dose-normalized pharmacokinetic parameters were similar for adult versus pediatric patients receiving 60 Units/kg: Cmax expressed in ng/mL/mg was 42.4 (14.5-95.4 in adults and 46.6 (34.4-68.4 in pediatric patients, AUC0 t expressed in ng • h/mL/mg was 63.4 (26.3-156 in adults and 63.9 (39.8-85.1 in pediatric patients, t1/2 expressed in minutes was 34.8 (11.3-104 in adults and 31.5 (18.0-42.9 in pediatric patients and total body clearance expressed in L/h was 19.9 (6.25-37.9 in adults and 17.0 (11.7-24.9 in pediatric patients. These pharmacokinetic data extend the findings of taliglucerase alfa in adult and pediatric patients.ClinicalTrials.gov. NCT00376168 (in adults; NCT01411228 (in children.

  19. NGC 4254: An Act of Harassment Uncovered by the Arecibo Legacy Fast ALFA Survey

    CERN Document Server

    Haynes, Martha P; Kent, Brian R

    2007-01-01

    We present an HI map constructed from the Arecibo Legacy Fast ALFA (ALFALFA) survey of the surroundings of the strongly asymmetric Virgo cluster Sc galaxy NGC 4254. Noted previously for its lopsided appearance, rich interstellar medium, and extradisk HI emission, NGC 4254 is believed to be entering the Virgo environment for the first time and at high speed. The ALFALFA map clearly shows a long HI tail extending ~250 kpc northward from the galaxy. Embedded as one condensation within this HI structure is the object previously identified as a "dark galaxy": Virgo HI21 (Davies et al. 2004). A body of evidence including its location within and velocity with respect to the cluster and the appearance and kinematics of its strong spiral pattern, extra-disk HI and lengthy HI tail is consistent with a picture of "galaxy harassment" as proposed by Moore et al. (1996a,b; 1998). The smoothly varying radial velocity field along the tail as it emerges from NGC 4254 can be used as a timing tool, if interpreted as resulting f...

  20. Optically Unseen HI Detections towards the Virgo Cluster detected in the Arecibo Legacy Fast ALFA Survey

    CERN Document Server

    Kent, Brian R; Haynes, Martha P; Saintonge, Amelie; Stierwalt, Sabrina; Balonek, Thomas; Brosch, Noah; Catinella, Barbara; Koopmann, Rebecca A; Momjian, Emmanuel; Spekkens, Kristine

    2007-01-01

    We report the discovery by the Arecibo Legacy Fast ALFA (ALFALFA) survey of eight HI features not coincident with stellar counterparts in the Virgo Cluster region. All of the HI clouds have cz < 3000 km/s and, if at the Virgo distance, HI masses between 1.9 x 10**7 and 1.1 x 10**9 solar masses. Four of the eight objects were reported or hinted at by previous studies and "rediscovered" by ALFALFA. While some clouds appear to be associated with optical galaxies in their vicinity, others show no clear association with a stellar counterpart. Two of them are embedded in relatively dense regions of the cluster and are associated with M49 and M86; they were previously known. The others are mostly located in peripheral regions of the cluster. Especially notable are a concentration of objects towards the so-called M cloud, 3 to 5 degrees to the NW of M87, and a complex of several clouds projected roughly halfway between M87 and M49. The object referred to as VIRGOHI21 and proposed to be a "dark galaxy" is also dete...

  1. The Arecibo Legacy Fast ALFA Survey: VI. Second HI Source Catalog of the Virgo Cluster Region

    CERN Document Server

    Kent, Brian R; Haynes, Martha P; Martin, Ann M; Saintonge, Amélie; Stierwalt, Sabrina; Balonek, Thomas J; Brosch, Noah; Koopmann, Rebecca A

    2008-01-01

    We present the third installment of HI sources extracted from the Arecibo Legacy Fast ALFA extragalactic survey. This dataset continues the work of the Virgo ALFALFA catalog. The catalogs and spectra published here consist of data obtained during the 2005 and 2006 observing sessions of the survey. The catalog consists of 578 HI detections within the range 11h 36m 6.5; (b) high velocity clouds in the Milky Way or its periphery; and (c) signals of lower S/N which coincide spatially with an optical object and known redshift. 75% of the sources are newly published HI detections. Of particular note is a complex of HI clouds projected between M87 and M49 that do not coincide with any optical counterparts. Candidate objects without optical counterparts are few. The median redshift for this sample is 6500 km/s and the cz distribution exhibits the local large scale structure consisting of Virgo and the background void and the A1367-Coma supercluster regime at cz_sun ~7000 km/s. Position corrections for telescope poin...

  2. Alglucosidase alfa: Long term use in the treatment of patients with Pompe disease

    Directory of Open Access Journals (Sweden)

    Michael Beck

    2009-09-01

    Full Text Available Michael BeckChildren’s Hospital, University of Mainz, Mainz, GermanyAbstract: Pompe disease is a lysosomal storage disorder characterized by muscle weakness and cardiomyopathy. It shows a broad variability regarding the clinical severity as well as the age of onset. In the past, two different recombinant enzyme preparations have been developed for the treatment of Pompe patients: α-glucosidase, produced in rabbit milk, and α-glucosidase, produced in Chinese hamster ovary (CHO cell lines. The CHO enzyme received marketing approval in 2006 after it was proven to be effective in ameliorating muscle strength and improving heart function. The other has not been approved. The clinical efficacy of this enzyme preparation could be confirmed by several clinical trials in patients with different age of onset and disease severity. Enzyme replacement therapy, however, has its limitations due to unsatisfactory access of recombinant α-glucosidase to the muscle cells and due to the formation of antibodies. To overcome these therapeutic restraints, the development of a more effective enzyme preparation may become necessary.Keywords: alglucosidase alfa, alpha glucosidase, Pompe disease, enzyme replacement therapy, glycogen storage disorder type II, acid maltase deficiency

  3. Profile of alglucosidase alfa in the treatment of Pompe disease: safety, efficacy, and patient acceptability

    Directory of Open Access Journals (Sweden)

    Schneider I

    2016-01-01

    Full Text Available Ilka Schneider, Stephan Zierz Department of Neurology, Martin Luther University Halle-Wittenberg, Halle (Saale, Germany Abstract: Pompe disease, also referred to as glycogenosis type II, is a rare, autosomal recessive disorder that results from the deficiency of the glycogen-degrading enzyme acid α-glucosidase. The classical form presents shortly after birth with muscle hypotonia, cardiac, and respiratory failure resulting in a fatal outcome. The late onset of Pompe disease has a very variable onset and disease presentation that often causes a delayed diagnosis. Until now enzyme replacement therapy with alglucosidase alfa is the only causative therapy option for Pompe patients that can slow down disease progression. However, uncertainty remains about the efficacy regarding survival and quality of life in Pompe patients under this very cost-intensive treatment. This paper provides a systematic review of the literature stressing different aspects of enzyme replacement therapy in infantile and late onset Pompe patients. Keywords: lysosomal storage disease, glycogenosis type II, acid maltase deficiency, IOPD, LOPD, enzyme replacement therapy

  4. [PROWESS, ENHANCE and ADDRESS: clinical implications for the treatment with drotrecogin alfa (activated)].

    Science.gov (United States)

    Cobas Meyer, M; Langenfeld, H; Rossaint, R; Sablotzki, A

    2006-06-01

    Drotrecogin alfa (activated) (DrotAA) represents a therapeutic advance in the treatment of severe sepsis. In the pivotal PROWESS trial DrotAA had demonstrated a significant decrease in 28-day mortality, most evident in the subgroup of patients at higher risk of death. Thus, DrotAA was licensed throughout Europe for treatment of adult patients with severe sepsis with multiple organ failure when added to best standard care. The ADDRESS trial was mandated by the FDA to investigate prospectively the treatment effect of DrotAA in patients at low risk of death, e.g. single organ failure. The trial was prematurely stopped due to futility, because no reduction in mortality was observed in this non-indicated patient population. The ENHANCE open-label trial enrolled similar patients to the PROWESS trial and the observed 28-day mortality was consistent with the results seen in the PROWESS trial. Survival rates for patients receiving DrotAA early within 24 h from the first sepsis-induced organ dysfunction were significantly higher than in patients treated later. In this overview we will discuss the results of the ENHANCE and ADDRESS trials in the context of the PROWESS study and clinical implications for the treatment with DrotAA.

  5. Reversing anticoagulant effects of novel oral anticoagulants: role of ciraparantag, andexanet alfa, and idarucizumab

    Directory of Open Access Journals (Sweden)

    Hu TY

    2016-02-01

    Full Text Available Tiffany Y Hu,1 Vaibhav R Vaidya,2 Samuel J Asirvatham2,31Mayo Medical School, 2Division of Cardiovascular Diseases, Department of Internal Medicine, 3Department of Pediatrics and Adolescent Medicine, Mayo Clinic, Rochester, MN, USAAbstract: Novel oral anticoagulants (NOACs are increasingly used in clinical practice, but lack of commercially available reversal agents is a major barrier for mainstream use of these therapies. Specific antidotes to NOACs are under development. Idarucizumab (aDabi-Fab, BI 655075 is a novel humanized mouse monoclonal antibody that binds dabigatran and reverses its anticoagulant effect. In a recent Phase III study (Reversal Effects of Idarucizumab on Active Dabigatran, a 5 g intravenous infusion of idarucizumab resulted in the normalization of dilute thrombin time in 98% and 93% of the two groups studied, with normalization of ecarin-clotting time in 89% and 88% patients. Two other antidotes, andexanet alfa (PRT064445 and ciraparantag (PER977 are also under development for reversal of NOACs. In this review, we discuss commonly encountered management issues with NOACs such as periprocedural management, laboratory monitoring of anticoagulation, and management of bleeding. We review currently available data regarding specific antidotes to NOACs with respect to pharmacology and clinical trials.Keywords: novel oral anticoagulant, dabigatran, idarucizumab, reversal

  6. Effect of wool and thermo-binder fibers on adhesion of alfa fibers in polyester composite

    Science.gov (United States)

    Omri, Med. Amin; Triki, A.; Guicha, M.; Hassen, Med. Ben; Arous, M.; Ahmed El Hamzaoui, H.; Bulou, A.

    2013-12-01

    Dielectric study was investigated in order to probe the interfacial region fibers/matrix of the polyester composite reinforced with alfa/wool/thermo-binder fibers. Dielectric spectra were measured in the frequency range from 10-1 Hz to 106 Hz, and temperature interval from 40 °C to 150 °C. This study revealed the presence of two dielectric relaxations in the composite. While the first one was attributed to the α mode relaxation associated with the glass transition of the matrix, the second was associated with the conductivity resulting from the carriers' charges diffusion noted for high temperature above glass transition and low frequencies. As this study did not show the presence of the interfacial polarization effect in the composite, it was accomplished with the vibrational study using the FT-IR and Raman techniques. A great compatibility between fibers and matrix was proven by a less hydrophilic character of the reinforcement giving rise to additional valence vibrations from wool fibers and hydrogen bonds.

  7. Arecibo Pulsar Survey Using ALFA. III. Precursor Survey and Population Synthesis

    CERN Document Server

    Swiggum, J K; McLaughlin, M A; Bates, S D; Champion, D J; Ransom, S M; Lazarus, P; Brazier, A; Hessels, J W T; Nice, D J; Ellis, J; Senty, T R; Allen, B; Bhat, N D R; Bogdanov, S; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J S; Freire, P C C; Jenet, F A; Karako-Argaman, C; Kaspi, V M; Knispel, B; Lee, K J; Van Leeuwen, J; Lynch, R; Lyne, A G; Scholz, P; Siemens, X; Stairs, I H; Stappers, B W; Stovall, K; Venkataraman, A; Zhu, W W

    2014-01-01

    The Pulsar Arecibo L-band Feed Array (PALFA) Survey uses the ALFA 7-beam receiver to search both inner and outer Galactic sectors visible from Arecibo ($32^{\\circ}\\lesssim \\ell \\lesssim 77^{\\circ}$ and $168^{\\circ}\\lesssim \\ell \\lesssim 214^{\\circ}$) close to the Galactic plane ($|b|\\lesssim5^{\\circ}$) for pulsars. In this paper we detail a precursor survey of this region with PALFA, which observed a subset of the full region (slightly more restrictive in $\\ell$ and $|b|\\lesssim1^{\\circ}$) and detected 45 pulsars. For both Galactic millisecond and normal pulsar populations, we compare the survey's detections with simulations to model these populations and, in particular, to estimate the number of observable pulsars in the Galaxy. We place 95\\% confidence intervals of 82,000 to 143,000 on the number of detectable normal pulsars and 9,000 to 100,000 on the number of detectable millisecond pulsars in the Galactic disk. These are consistent with previous estimates. Given the most likely population size in each ca...

  8. LHC Report: special run with de-squeezed beams for ATLAS/ALFA and TOTEM

    CERN Multimedia

    Helmut Burkhardt for the LHC team

    2015-01-01

    The main high-luminosity proton-proton run of the LHC is complemented by one week per year of special proton-proton runs. The special runs are performed with larger beam sizes at the interaction points to allow the forward physics experiments, TOTEM and ATLAS/ALFA, the chance to make precise measurements of protons as they emerge from collisions at small angles.   In standard high-luminosity operation, the beams are squeezed to give small beam sizes at the interaction points to maximise the collision rates. The “squeeze” takes place at top energy and the beam size at the centre of ATLAS (IP1) and CMS (IP5) is reduced from 66 micrometres at the top of the ramp to 18 micrometres before colliding beams are established. Protons that avoid the fate of an inelastic collision but yet still interact – in elastic or diffractive events – are scattered and emerge in the forward direction. The reduction in beam size has a side effect of increasing the an...

  9. Peg-Interferon Alfa 2-b Related Cellulitis in a 40 Years Man

    Directory of Open Access Journals (Sweden)

    Shahnaaz Sali

    2016-01-01

    Full Text Available Background: Pegylated interferon and ribavirin are currently one of the accepted treatment for chronic Hepatitis C. Dermatologic complications of interferon have been reported, but to date a few cases of bacterial cellulitis; a rare and severe complication, have been published. Cellulitis is a common infectious process affecting the skin and subcutaneous tissues which results in significant morbidity and holds considerable healthcare costs.Cases Report: Herein, we report a case of chronic hepatitis C genotype 1a who was on medication since 8 weeks prior to developing leg cellulitis, an uncommon pegylated interferon injection site. Considering no other possible risk factors were found to be in favor of bacterial cellulitis, our case is unique in its kind. Some reports reveal necrotizing vasculitis as basis for cutaneous lesions, which could be due to the high concentrations of drug at the injection site, a toxic effect of the diluents, or an immunological reaction.Conclusion: According to the latter mechanism patients could develop bacterial cellulitis in their different organs. Conclusively, we propose the hypothesis of a possible association between cellulitis to occur at any site as the complication of pegylated interferon Alfa 2b and would highlight the role of a careful skin examination that could be an asset in preventing local skin infections.

  10. Autoantibodies to alfa-fodrin in patients with Hashimoto thyroiditis and Sjögren's syndrome: possible markers for a common secretory disorder.

    Science.gov (United States)

    Szanto, Antonia; Csipo, Istvan; Horvath, Ildiko; Biro, Edit; Szodoray, Peter; Zeher, Margit

    2008-09-01

    Presence of autoantibodies to alfa-fodrin was investigated in patients with Sjögren's syndrome (n = 61), Hashimoto thyroiditis (n = 27), Sjögren's syndrome associated with Hashimoto thyroiditis (n = 31) and in healthy persons (n = 77). In each group, level of alfa-fodrin antibodies was higher than in the controls. There was no significant difference in their presence either between patients with Hashimoto thyroiditis with or without Sjögren's syndrome, or-in IgA isotype-between Sjögren's and Hashimoto thyroiditis patients. Correlation was found between the level of IgG alfa-fodrin and anti-thyroglobulin antibodies. Based on these findings, fodrin can be associated with both endocrine and exocrine glandular secretion. Antibodies to alfa-fodrin might have a role in the pathogenesis of Hashimoto thyroiditis concerning the "final common effectory pathway", secretion. Alfa-fodrin antibodies can be good markers of secretory disorders. Assessment of these autoantibodies might help the diagnosis and follow-up of patients with impaired secretory capability of not only autoimmune origin.

  11. Análise comparativa do controle interno no contas a receber e a pagar nas empresas Beta Ltda e Alfa Ltda = A comparative internal control analysis of receivable and payable accounts in Beta and Alfa Ltd Companies

    Directory of Open Access Journals (Sweden)

    Cleyton de Oliveira Ritta

    2010-07-01

    Full Text Available A necessidade constante de um excelente desempenho empresarial leva à busca da qualidade e confiabilidade da informação para o auxílio na tomada de decisão. Neste contexto, a auditoria contábil tem um papel importante na análise das práticas administrativas adotadas pelas entidades. Desse modo, o objetivo deste artigo é comparar a estruturação dos controles internos no contas a receber e a pagar nas empresas Beta Ltda, a qual não contrata serviços de auditoria externa, e Alfa Ltda, que os contrata. Este estudo caracteriza-se como de caso comparativo de caráter descritivo por meio de questionário e entrevista. Os resultados apontam que a empresa Alfa Ltda tem melhores níveis de controle interno e, consequentemente, está menos exposta a erros e fraudes. Desse modo, entende-se que os seviços de auditoria atuam como um instrumento de auxílio para minimização dos riscos operacionais e servem de alerta aos gestores quanto à eficiência das transações. Contudo, percebe-se que a qualidade dos controles internos nas organizações depende diretamente da utilização de procedimentos de monitoramento.The constant need for excellent business performance triggers the quest for information quality and reliability to help in decision making. Considering this context, accounting auditing plays an important role in the analysis of administrative practices adopted by entities. Thus, the objective of this article is to compare the structure of the internal controls for receivable and payable accounts in Beta Ltd companies, which do not contract external auditing services, and Alfa Ltd, which does. This study is a descriptive comparative case study, carried out through questionnaire and interview. The results have showed that Alfa Ltd has better internal control levels and consequently is less exposed to errors and fraud. This way, auditing services are seen as auxiliary instruments to minimize operational risks and serve to alert

  12. CHANGES IN TUMOR NECROSIS FACTOR ALFA DURING TREATMENT OF PATIENTS WITH MULTIPLE SCLEROSIS BY TRANSIMMUNIZATION METHOD

    Directory of Open Access Journals (Sweden)

    A. V. Kil'dyushevskiy

    2016-01-01

    Full Text Available Background: Despite the availability of a  large number of treatments for multiple sclerosis with various targets, these treatments are not always effective. According to the literature, experimental studies have shown a  significant decrease in tumor necrosis factor alfa (TNF-α with the use of extracorporeal photochemotherapy. Aim: To assess changes in TNF-α in patients with multiple sclerosis during treatment with transimmunization. Materials and methods: The study recruited 13 adult patients with multiple sclerosis. Serum TNF-α was measured by immunochemiluminescence analysis (IMMULITE 1000, Siemens. The patients were treated by transimmunization, i.e. a  modified photopheresis. Two hours before the procedure, Ammifurin (8-methoxypsoralene was administered to all the patients, then their mononuclear cells were isolated under PBSC protocol with Haemonetics MCS+ cell separator. Thereafter, mononuclear cells were irradiated with ultraviolet for 90  minutes and incubated for 20 hours at 37 °С. The next day the cells were re-infused to the patients. The procedure was performed 2  times per week for 6  months, then once per 4  months. Results: Before transimmunization, mean TNF-α level in adult patients with multiple sclerosis was 9.958±0.812  pg/mL (normal, below 8.1 pg/mL. After transimmunization, its level was 6.992±0.367  pg/mL (р<0.05. Conclusion: Ultraviolet irradiation of peripheral blood monocytes with their subsequent incubation (transimmunization led to a 30% decrease of serum TNF-α in patients with multiple sclerosis. This indicates a suppressive effect of transimmunization on TNF-α. Hence, in patients with multiple sclerosis transimmunization exerts an anti-inflammatory effect.

  13. Direct site-specific glycoform identification and quantitative comparison of glycoprotein therapeutics: imiglucerase and velaglucerase alfa.

    Science.gov (United States)

    Ye, Hongping; Hill, John; Gucinski, Ashley C; Boyne, Michael T; Buhse, Lucinda F

    2015-03-01

    Gaucher disease, the most common lysosomal metabolic disorder, can be treated with enzyme replacement therapy (ERT). Recombinant human glucocerebrosidase imiglucerase (Cerezyme(®)), produced in Chinese hamster ovary cells, has been used for ERT of Gaucher disease for 20 years. Another recombinant glucocerebrosidase velaglucerase alfa (VPRIV), expressed in a human fibroblast cell line, was approved by the US Food and Drug Administration in 2010. The amino acid sequence difference at residue 495 of these two products is well documented. The overall N-linked qualitative glycan composition of these two products has also been reported previously. Herein, employing our recently developed approach utilizing isobaric tandem mass tag (TMT) labeling and an LTQ Orbitrap XL electron transfer dissociation (ETD) hybrid mass spectrometer, the site-specific glycoforms of these products were identified with ETD and collision-induced dissociation (CID) spectra. The quantitative comparison of site-specific glycans was achieved utilizing higher-energy collisional dissociation (HCD) spectra with a NanoMate used as both a fraction collector and a sample introduction device. From the trypsin-digested mixture of these two products, over 90 glycopeptides were identified by accurate mass matching. In addition to those previously reported, additional glycopeptides were detected with moderate abundance. The relative amount of each glycoform at a specific glycosylation site was determined based on reporter signal intensities of the TMT labeling reagents. This is the first report of site-specific simultaneous qualitative and quantitative comparison of glycoforms for Cerezyme(®) and VPRIV. The results demonstrate that this method could be utilized for biosimilarity determination and counterfeit identification of glycoproteins.

  14. Effects of alfa-hydroxy-isocaproic acid on body composition, DOMS and performance in athletes

    Directory of Open Access Journals (Sweden)

    Karila Tuomo AM

    2010-01-01

    Full Text Available Abstract Background Alfa-Hydroxy-isocaproic acid (HICA is an end product of leucine metabolism in human tissues such as muscle and connective tissue. According to the clinical and experimental studies, HICA can be considered as an anti-catabolic substance. The present study investigated the effects of HICA supplementation on body composition, delayed onset of muscle soreness (DOMS and physical performance of athletes during a training period. Methods Fifteen healthy male soccer players (age 22.1+/-3.9 yr volunteered for the 4-week double-blind study during an intensive training period. The subjects in the group HICA (n = 8 received 583 mg of sodium salt of HICA (corresponding 500 mg of HICA mixed with liquid three times a day for 4 weeks, and those in the group PLACEBO (n = 7 received 650 mg of maltodextrin mixed with liquid three times a day for the same period. According to a weekly training schedule, they practiced soccer 3 - 4 times a week, had strength training 1 - 2 times a week, and had one soccer game during the study. The subjects were required to keep diaries on training, nutrition, and symptoms of DOMS. Body composition was evaluated with a dual-energy X-ray absorptiometry (DXA before and after the 4-week period. Muscle strength and running velocity were measured with field tests. Results As compared to placebo, the HICA supplementation increased significantly body weight (p th week of the treatment (p Conclusion Already a 4-week HICA supplementation of 1.5 g a day leads to small increases in muscle mass during an intensive training period in soccer athletes.

  15. Low-latitude Ionospheric Research using the CIRCE Mission

    Science.gov (United States)

    Dymond, K.; Nicholas, A. C.; Budzien, S. A.; Stephan, A. W.

    2016-12-01

    The Coordinated Ionospheric Reconstruction Cubesat Experiment (CIRCE) is a dual-satellite mission consisting of two 6U CubeSats actively maintaining a lead-follow configuration in the same orbit with a launch planned for the 2018-2019 time frame. These nano-satellites will each feature two 1U ultraviolet photometers, observing the 135.6 nm emission of atomic oxygen at nighttime. The primary objective is to characterize the two-dimensional distribution of electrons in the Equatorial Ionization Anomaly (EIA). The methodology used to reconstruct the nighttime ionosphere employs continuous UV photometry from four distinct viewing angles in combination with an additional data source, such as in situ plasma density measurements or a wide-band beacon data, with advanced image space reconstruction algorithm tomography techniques. The COSMIC/FORMOSAT-3 (CF3) constellation featured six Tiny Ionospheric Photometers, a compact UV sensor design which served as the pathfinder for the CIRCE instruments. The TIP instruments on the CF3 satellites demonstrated detection of ionospheric bubbles before they had penetrated the peak of the F-region ionosphere. We present our mission concept, simulations illustrating the imaging capability of the sensor suite, and a range of science questions addressable using such a system.

  16. Thermospheric zonal temperature gradients observed at low latitudes

    Directory of Open Access Journals (Sweden)

    P. R. Fagundes

    Full Text Available Fabry-Perot interferometer (FPI measurements of thermospheric temperatures from the Doppler widths of the OI 630 nm nightglow emission line have been carried out at Cachoeira Paulista (23° S, 45° W, 16° S dip latitude, Brazil. The east-west components of the thermospheric temperatures obtained on 73 nights during the period from 1988 to 1992, primarily under quiet geomagnetic conditions, were analyzed and are presented in this paper. It was observed that on 67% of these nights, the temperatures in both the east and west sectors presented similar values and nocturnal variations. However, during 33% of the nights, the observed temperatures in the west sector were usually higher than those observed in the east sector, with zonal temperature gradients in the range of 100 K to 600 K, over about an 800 km horizontal distance. Also, in some cases, the observed temperatures in the east and west sectors show different nocturnal variations. One of the possible sources considered for the observed zonal temperature gradients is the influence of gravity wave dissipation effects due to waves that propagate from lower altitudes to thermospheric heights. The observed zonal temperature gradients could also be produced by orographic gravity waves originated away, over the Andes Cordillera in the Pacific Sector, or by dissipation of orographic gravity waves generated over the Mantiqueira Mountains in the Atlantic sector by tropospheric disturbances (fronts and/or subtropical jet streams.

    Key words. Atmospheric composition and structure (air-glow and aurora; thermosphere - composition and chemistry Ionosphere (equatorial ionosphere

  17. Seasonal variabilities of low-latitude mesospheric winds

    Directory of Open Access Journals (Sweden)

    R. Rajaram

    Full Text Available Observations of mesospheric winds over a period of four years with the partial reflection radar at Tirunelveli (8.7°N, 77.8°E, India, are presented in this study. The emphasis is on describing seasonal variabilities in mean zonal and meridional winds in the altitude region 70–98 km. The meridional winds exhibit overall transequatorial flow associated with differential heating in the Northern and Southern Hemispheres. At lower altitudes (70–80 km the mean zonal winds reveal easterly flow during summer and westerly flow during winter, as expected from a circulation driven by solar forcing. In the higher altitude regime (80–98 km and at all altitudes during equinox periods, the mean zonal flow is subjected to the semi-annual oscillation (SAO. The interannual variability detected in the occurrence of SAO over Tirunelveli has also been observed in the data sets obtained from the recent UARS satellite mission. Harmonic analysis results over a period of two years indicate the presence of long-period oscillations in the mean zonal wind at specific harmonic periods near 240, 150 and 120 days. Results presented in this study are discussed in the context of current understanding of equatorial wave propagation.

    Key words. Meteorological and atmospheric dynamics · General circulation · Middle atmosphere dynamics · waves and tides.

  18. Statistical Evaluation of Forecasts Over the Low-Latitudes.

    Science.gov (United States)

    1985-08-01

    o o .x 1. Introduction .. . ........ .. .- 2. The Models . . . . . . . . . . . ... ... 4 2.1 Filtered barotropic modelo . ....... ... 4 2.1.1...boundaries, producing a continuity of the analysis in a cyclic Ct 7 sense . The north and south bounderies were treated differently. The initial

  19. Low-latitude ice cores and freshwater availability

    Science.gov (United States)

    Kehrwald, Natalie Marie

    2009-12-01

    Recent retreat of Tibetan Plateau glaciers affects at least half a billion people. Himalayan glaciers seasonally release meltwater into tributaries of the Indus, Ganges, and Brahmaputra Rivers and supply freshwater necessary to support agricultural and economic practices. Tibetan Plateau glaciers are retreating more rapidly than mountain glaciers elsewhere in the world, and this retreat is accelerating. The Naimona'nyi (30°27'N; 81°91'E, 6050 m a.s.l), Guliya (35°17'N; 81°29'E, 6710 m a.s.l.) and Dasuopu (28°23'N; 85°43'E, 7200 m a.s.l.) ice cores place this recent retreat into a longer time perspective through quantifying climate parameters such as past temperature, aridity, and atmospheric chemistry. Naimona'nyi has not accumulated mass since at least 1950, as evidenced by the virtual lack of radiogenic isotopes (36Cl, 3 H, and beta radioactivity) present in the ice core. These isotopes were produced by U.S. and Soviet atmospheric thermonuclear bomb tests conducted in the 1950s and 1960s and provide independent dating horizons for the ice cores. Lead-210 dates imply that the uppermost preserved glacial ice on Naimona'nyi formed during the 1940s. While this is the highest documented glacial thinning in the world other glaciers at elevations similar to that of Naimona'nyi, such as Kilimanjaro (3°4'S; 37°21'E, 5893 m a.s.l.), are also losing mass at their summits. The global scope of high-elevation glacial thinning suggests that ablation on the Earth's highest ice fields may be more prevalent as global mean temperatures continue to increase. Glacial thinning has not been taken into account in future projections of regional freshwater availability, and the net mass loss indicates that Himalayan glaciers currently store less freshwater than assumed in models. The acceleration of Tibetan Plateau glacial retreat has been hypothesized to be due in part to deposition of black carbon (BC) from biomass burning on to ice fields, thereby lowering the reflectivity of the glacier surface and melting the upper ice. The application of a novel technique of measuring and radiocarbon-dating ultra-small samples (Precambrian black shale in the Lesser Himalaya provide a natural source material which may be operationally defined as black carbon and which may incorporate radiocarbon-dead sediments into the bulk 14C measurements, yet as the mean 14C age is ˜10 ka, modern BC from biomass burning must also be incorporated into the ice core record. While the uppermost sample (5 m) contains 38% BC, 210 Pb dates show that this depth corresponds to an age before 1850 AD, or before the regional Industrial Revolution. As BC is a hydrophobic substance, the BC is unlikely to have migrated through the firn and glacial ice. Therefore, the high-elevation thinning on Naimona'nyi appears to be a response to increased temperatures rather than primarily driven by changes in surface albedo. This technique was applied to the annually-dated ice core from the accumulating summit of the Quleccaya ice cap, Peru (13'56'S; 70°50'W; 5670 m a.s.l.). A marked increase in modern BC and TOC was measured since 1880 AD. No increase in radiocarbon-dead (> 60,000 ka) BC or TOC was noted, suggesting that the source of the carbon was from biomass burning, with a possible contribution of Amazon slash and burn clearing, rather than the input of fossil fuel combustion. The age of the BC and TOC is thousands of years older than the age of the surrounding ice, and should not be used to date the ice core. Although Naimona'nyi provides challenges for constructing an ice core chronology due to its lack of independent horizons such as volcanic activity, methane gas measurements, 14C dates, 3H, 36Cl, or beta radioactivity, the oxygen isotopic record can be correlated with the neighboring Dasuopu and Guliya ice cores. Naimona'nyi contains a pronounced positive ˜10‰ shift in delta18O in the basal 37 m of the core which mimics similar isotopic shifts in regional speleothems, lacustrian sediments, and planktonic foraminifera proxy records. This distinct shift is attributed to ampl

  20. Letter to the Editor: Geomagnetic storm effects at low latitudes

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    Full Text Available The geomagnetic horizontal (H field from the chain of nine observatories in India are used to study the storm-time and disturbance daily variations. The peak decrease in storm-time variation in H showed significant enhancements at the equatorial electrojet stations over and above the normally expected decrease due to the ring current effects corrected for geomagnetic latitudes. The disturbance daily variation of H at equatorial stations showed a large decrease around midday hours over and above the usual dawn-maximum and dusk-minimum seen at any mid-latitude stations around the world. These slow and persistent additional decreases of H of disturbance daily variation at equatorial latitudes could be the effect of a westward electric field due to the Disturbance Ionospheric dynamo coupled with abnormally large electrical conductivities in the E region over the equator.Key words. Ionosphere (electric fields and currents · Magnetospheric physics (electric fields; storms and substorms

  1. A Semi-Empirical Low-Latitude Ionospheric Model

    Science.gov (United States)

    1988-10-06

    the atmosphere, P., a value of marca incoherent scatter radar observations reported 5.5 x 10- s ’ represents solar cycle maximum con- by Fejer et al...bottomside components of the overall profiles with N(h) = N ex [c -:. - e)] good results. It was decided, therefore, to define a (h- h...) "generalized" or

  2. Jellyfish Patch Detecting Using Low Latitude Remote Sensing System

    Science.gov (United States)

    Lee, J. S.; Jo, Y. H.

    2015-12-01

    Jellyfish can be asexual and sexual reproduction depending on the environment, and it has excellent environmental adaptability and reproduction than other sea creatures. If the marine environment become worse, jellyfish can take advantage in the competition for survival. Marine environmental changes caused by rapid climate change, dyke construction and land reclamation will increase the amount of jellyfish and as a result can lead to a various social and economic problems. In this study, jellyfish were observed in coastal area using a low-altitude Helikite remote sensing system for the first time. Helikite is a type of helium balloon plus a kite that can get the data with optical sensors for the desired spatial resolutions by adjusting the altitudes. In addition, it has an advantage that can monitor any objects for a long time at one place as long as the electric power and helium last. In this study, we observed the jellyfish patches using a digital camera in the Chesapeake Bay and estimate populations and size of jellyfish patches through image processing. Research results suggests that we can have long-term real-time observations for not only jellyfish, but also other harmful marine creatures.

  3. VHF radar observations of gravity waves at a low latitude

    Directory of Open Access Journals (Sweden)

    G. Dutta

    Full Text Available Wind observations made at Gadanki (13.5°N by using Indian MST Radar for few days in September, October, December 1995 and January, 1996 have been analyzed to study gravity wave activity in the troposphere and lower stratosphere. Horizontal wind variances have been computed for gravity waves of period (2-6 h from the power spectral density (PSD spectrum. Exponential curves of the form eZ/H have been fitted by least squares technique to these variance values to obtain height variations of the irregular winds upto the height of about 15 km, where Z is the height in kilometers. The value of H, the scale height, as determined from curve fitting is found to be less than the theoretical value of scale height of neutral atmosphere in this region, implying that the waves are gaining energy during their passage in the troposphere. In other words, it indicates that the sources of gravity waves are present in the troposphere. The energy densities of gravity wave fluctuations have been computed. Polynomial fits to the observed values show that wave energy density increases in the troposphere, its source region, and then decreases in the lower stratosphere.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; turbulence; waves and tides

  4. Projected beam irradiation at low latitudes using Meteonorm database

    DEFF Research Database (Denmark)

    Hatwaambo, Sylvester; Perers, Bengt; Karlsson, Björn

    2009-01-01

    by a collector provided the projection angle lies within the acceptance angle. The Meteonorm method of calculating solar radiation on any arbitrary oriented surface uses the globally simulated meteorological databases. Meteonorm has become a valuable too for estimating solar radiation where measured solar...

  5. Low latitude electron temperature observed by the CHAMP satellite

    DEFF Research Database (Denmark)

    Stolle, Claudia; Truhlik, V.; Richards, P.;

    2012-01-01

    km, although this was not predicted by earlier models. The temperature peaks coincides with the density peaks and are increased during high solar flux. Even more extended possibilities in investigating the ionosphere/thermosphere system are expected from the ESA Swarm satellite constellation mission...

  6. Mucoproteína versus alfa-1-glicoproteína ácida: o que quantificar?

    Directory of Open Access Journals (Sweden)

    Picheth Geraldo

    2002-01-01

    Full Text Available A quantificação sérica da alfa-1-glicoproteína (GPA ácida é útil no diagnóstico e no acompanhamento dos processos agudos resultantes de múltiplas causas. Esta proteína também pode ser estimada pela quantificação da mucoproteína (Muco, ensaio que reflete as glicoproteínas com elevado teor de açúcar, entre as quais a GPA é majoritária. O objetivo deste trabalho é verificar a correlação e a performance analítica das determinações de mucoproteína (Muco e alfa-1-glicoproteína ácida (GPA, propondo uma equação de regressão linear. Amostras de soros de 540 pacientes, com idades entre 10 e 79 anos (média de 34,6, predominando mulheres (71,3%, foram analisadas simultaneamente para Muco (Winzler, manual com reagentes próprios e GPA (imunoturbidimetria automatizada, Roche; Cobas mira. A análise de regressão, fixando a Muco como variável dependente, apresentou Muco (mg/dl em tirosina = 0,031 x GPA (mg/dl + 0,8 (r = 0,91; e, fixando o intercepto em zero, Muco = 0,039 x GPA (r = 0,98. A imprecisão interensaio foi de 23,4% e 5,2% (coeficiente de variação, respectivamente, para Muco e GPA. Conclusão: a elevada variabilidade analítica da quantificação da mucoproteína pelo método de Winzler recomenda que este ensaio seja substituído pela dosagem da alfa-1-glicoproteína ácida. Quando necessário, recomendamos estimar a mucoproteína, quantificando a alfa-1-glicoproteína ácida com ensaios de mesmo desempenho que o do utilizado neste trabalho, e usar a equação de regressão AGP (mg/dl x 0,039 = Muco (mg/dl em tirosina.

  7. Factor de necrosis tumoral alfa en pacientes con preeclampsia a término y pretérmino

    Directory of Open Access Journals (Sweden)

    Eduardo Reyna Villasmil

    2012-07-01

    Full Text Available El objetivo de la investigación fue identificar y comparar las concentraciones de factor de necrosis tumoral alfa en pacientes con preeclampsia a término y pre-término. Se seleccionó un total de 50 pacientes. Se incluyeron a 20 pacientes preeclámpticas pre-término (grupo A y 30 preeclámpticas a término (grupo B. Las muestras de sangre para la determinación de factor de necrosis tumoral alfa se recolectaron en todas las pacientes antes del parto e inmediatamente después del diagnóstico de preeclampsia. No se encontraron diferencias significativas con relación a la edad materna e Índice de masa corporal al momento de la toma de la muestra. Se observaron diferencias estadísticamente significativas entre los grupos con respecto a la edad gestacional (p < 0,0001. El valor promedio de la presión arterial sistólica en el grupo A fue de 149,4 ± 11,3 mmHg mientras que en las pacientes del grupo B fue de 148,1 ± 12,3 mmHg (p = 0,7071 y el valor promedio de presión arterial diastólica en el grupo A fue de 103,8 ± 8,6 mmHg y en el grupo B fue de 102,7 ± 7,9 mmHg (p = 0,6436. Las concentraciones de factor de necrosis tumoral alfa fueron similares en el grupo de preeclámpticas pre-término (98,2 ± 45,1 pg/mL comparado con el grupo de preeclámpticas a término (96,6 ± 48,7 pg/mL; p = 0,9072. Al realizar la correlación entre los valores de factor de necrosis tumoral alfa con los valores de presión arterial se observó que no existía correlación con la presión arterial sistólica (r = 0,129; p = 0,374 ni con la de presión arterial diastólica (r = 0,158, p = 0,273. Se concluye que las concentraciones sanguíneas del factor de necrosis tumoral alfa resultaron similares en las pacientes preeclámpticas con embarazo pretérmino y a término. La correlación de las concentraciones de factor de necrosis tumoral alfa con los valores de presión arterial sistólica y diastólica resultó no significativa. Palabras clave:Factor de

  8. Onset of Type 1 Diabetes Mellitus During Pegylated-interferon Alfa and Ribavirin Therapy for Chronic Hepatitis C Virus Infection

    Science.gov (United States)

    Ranganathan, Raghini; Janarthanan, Krishnaveni; Rajasekaran, Senthilkumar

    2012-01-01

    A 16-year-old female was treated with pegylated-interferon (PEG-IFN) alfa (a)-2b and ribavirin combination therapy for chronic hepatitis C virus (HCV) infection. She attained rapid virological response. She presented with diabetic ketoacidosis after 41 weeks of therapy. Anti-glutamic acid decarboxylase antibodies and islet cell antibodies were negative. Her fasting serum C-peptide level was <0.1 ng/mL, and the treatment course was completed. This case underlines the importance of periodic plasma glucose monitoring in patients during and after PEG-IFN and ribavirin therapy. PMID:25755410

  9. AlphaCI: un programa de cálculo de intervalos de confianza para el coeficiente alfa de Cronbach

    OpenAIRE

    Rubén Ledesma

    2004-01-01

    El coeficiente alfa de Cronbach es el modo más habitual de estimar la fiabilidad de pruebas basadas en Teoría Clásica de los Test. En dicha estimación, los investigadores usualmente omiten informar intervalos de confianza para el coeficiente, un aspecto no solo recomendado por los especialistas, sino también requerido explícitamente en las normas editoriales de algunas revistas especializadas. Esta situación puede atribuirse a que los métodos de estimación de intervalos de confianza son poco ...

  10. Tratamento de reposição na deficiência de alfa-1-antitripsina em doentes com enfisema pulmonar

    OpenAIRE

    2013-01-01

    A doença pulmonar obstrutiva crónica é uma das principais causas de incapacidade respiratória e a quarta causa de morte em todo o Mundo, sendo mais frequente no sexo masculino. A exposição ao fumo do tabaco é considerada o principal fator de risco ambiental, no entanto, existem outros fatores igualmente importantes como, por exemplo, a deficiência de alfa-1-antitripsina, a única desordem genética conhecida associada a esta patologia até aos dias de hoje. Esta enzima é maioritariamente produzi...

  11. Guillain-Barre syndrome associated with peginterferon alfa-2a for chronic hepatitis C: A case report

    Science.gov (United States)

    Niazi, Mumtaz A; Azhar, Ashaur; Tufail, Kashif; Feyssa, Eyob L; Penny, Stephen F; McGregory, Marlene; Araya, Victor; Ortiz, Jorge A

    2010-01-01

    The recommended therapy for chronic hepatitis C (CHC) infection is the combination of a Pegylated interferon and Ribavirin. Almost all such patients on combination therapy experience one or more adverse events during the course of treatment. Significant neurological side effects are rare. A few cases of Bell’s Palsy, chronic inflammatory demyelinating polyneuropathy and even one case of acute demyelinating polyneuropathy with atypical features for Guillain-Barre syndrome (GBS) associated with Interferon therapy have been reported but no report of GBS with typical features has been published. We present a case report of typical GBS associated with Peginterferon alfa-2a and Ribavirin used for treatment of CHC infection. PMID:21160989

  12. Secondary bronchiolitis obliterans organizing pneumonia during treatment of chronic hepatitis C: role of pegylated interferon alfa-2a

    Directory of Open Access Journals (Sweden)

    Ronaldo Soares Martins

    2012-10-01

    Full Text Available The treatment of chronic hepatitis C has frequent side effects such as cytopenias and neuropsychiatric symptoms. However, pulmonary toxicity associated with interferon is rarely described. This paper describes the clinical case of a 67-year-old female patient with chronic hepatitis C who presented an acute onset of dry cough, dyspnoea, and fever 36 weeks after the use of pegylated interferon alfa-2a and ribavirin. The lung biopsy confirmed the diagnosis of a bronchiolitis obliterans organizing pneumonia (BOOP. Corticotherapy was initiated, with clinical and radiological improvement. This paper aims to advise physicians to this occasional, though severe, adverse event related to hepatitis C virus (HCV treatment.

  13. Comportamiento de glicinina, beta-conglicinina y alfa-amilasa en semillas de soja deterioradas y no deterioradas

    OpenAIRE

    2002-01-01

    El objetivo del trabajo fue estudiar el comportamiento de glicinina y beta-conglicinina y la actividad de alfa-amilasa en semillas deterioradas y no deterioradas de 10 cultivares de soja [Glycine max (L.) Merr.]. Las semillas se sometieron a dos tratamientos: deterioradas por envejecimiento acelerado y no deterioradas. Se determinó la presencia de las proteínas de reserva a partir de semillas con 0, 3 y 8 días de germinadas por electroforesis en geles de poliacrilamida (SDS-PAGE). La activida...

  14. A double-blind, non-inferiority RCT comparing corifollitropin alfa and recombinant FSH during the first seven days of ovarian stimulation using a GnRH antagonist protocol

    NARCIS (Netherlands)

    Devroey, P.; Boostanfar, R.; Koper, N. P.; Mannaerts, B. M. J. L.; IJzerman-Boon, P. C.; Fauser, B. C. J. M.

    2009-01-01

    Corifollitropin alfa, a fusion protein lacking LH activity, has a longer elimination half-life and extended time to peak levels than recombinant FSH (rFSH). A single injection of corifollitropin alfa may replace seven daily gonadotrophin injections during the first week of ovarian stimulation. In th

  15. Results from a large multinational clinical trial (guardian™3) using prophylactic treatment with turoctocog alfa in paediatric patients with severe haemophilia A: safety, efficacy and pharmacokinetics.

    Science.gov (United States)

    Kulkarni, R; Karim, F A; Glamocanin, S; Janic, D; Vdovin, V; Ozelo, M; Rageliene, L; Carboni, E; Laguna, P; Dobaczewski, G; Seremetis, S; Lindblom, A; Santagostino, E

    2013-09-01

    Recombinant factor VIII (rFVIII) products provide a safe and efficacious replacement therapy for prophylaxis and treatment of bleeding episodes in patients with severe haemophilia A. This multinational, open-label, non-controlled trial investigated the safety, efficacy and pharmacokinetics (PK) of turoctocog alfa, a new rFVIII product, in a paediatric population. The primary objective was to evaluate safety. A total of 31 younger children (0-5 years) and 32 older children (6-11 years), with ≥ 50 exposure days to any factor VIII (FVIII) product and no history of inhibitors, received prophylaxis with turoctocog alfa (25-50 IU kg(-1) every second day or 25-60 IU kg(-1) three times weekly). PK assessments of turoctocog alfa and the patients' previous FVIII product were performed in 28 patients. Mean exposure to turoctocog alfa was 60 exposure days per patient. This corresponds to approximately 4.5 months in the trial. None of the patients developed inhibitors (≥ 0.6 BU) and no safety concerns were raised. A total of 120 bleeding episodes (95%) were controlled with 1-2 infusions of turoctocog alfa. Based on patient reports, the success rate (defined as 'excellent' or 'good' haemostatic response) for treatment of bleeding episodes was 92%. Overall, the median annualized bleeding rate was 3.0 (interquartile range: 8.5) bleeds patient(-1) year(-1) . PK parameters were comparable between the two age groups. In conclusion, the present large global clinical trial showed that turoctocog alfa was safe, effective in treatment of bleeding episodes and had a prophylactic effect in paediatric patients. © 2013 John Wiley & Sons Ltd.

  16. Efficacy of corifollitropin alfa followed by recombinant follicle-stimulating hormone in a gonadotropin-releasing hormone antagonist protocol for Korean women undergoing assisted reproduction.

    Science.gov (United States)

    Park, Hyo Young; Lee, Min Young; Jeong, Hyo Young; Rho, Yong Sook; Song, Sang Jin; Choi, Bum-Chae

    2015-06-01

    To evaluate the effect of a gonadotropin-releasing hormone (GnRH) antagonist protocol using corifollitropin alfa in women undergoing assisted reproduction. Six hundred and eighty-six in vitro fertilization-embryo transfer (IVF)/intracytoplasmic sperm injection (ICSI) cycles were analyzed. In 113 cycles, folliculogenesis was induced with corifollitropin alfa and recombinant follicle stimulating hormone (rFSH), and premature luteinizing hormone (LH) surges were prevented with a GnRH antagonist. In the control group (573 cycles), premature LH surges were prevented with GnRH agonist injection from the midluteal phase of the preceding cycle, and ovarian stimulation was started with rFSH. The treatment duration, quality of oocytes and embryos, number of embryo transfer (ET) cancelled cycles, risk of ovarian hyperstimulation syndrome (OHSS), and the chemical pregnancy rate were evaluated in the two ovarian stimulation protocols. There were no significant differences in age and infertility factors between treatment groups. The treatment duration was shorter in the corifollitropin alfa group than in the control group. Although not statistically significant, the mean numbers of matured (86.8% vs. 85.1%) and fertilized oocytes (84.2% vs. 83.1%), good embryos (62.4% vs. 60.3%), and chemical pregnancy rates (47.2% vs. 46.8%) were slightly higher in the corifollitropin alfa group than in the control group. In contrast, rates of ET cancelled cycles and the OHSS risk were slightly lower in the corifollitropin alfa group (6.2% and 2.7%) than in the control group (8.2% and 3.5%), although these differences were also not statistically significant. Although no significant differences were observed, the use of corifollitropin alfa seems to offer some advantages to patients because of its short treatment duration, safety, lower ET cancellation rate and reduced risk of OHSS.

  17. Informe sobre el Proyecto Alfa Biblioteca de Babel: ¿Un atajo para la administración de bibliotecas universitarias? Biblioteca de Babel Alfa Project Report: A shortcut for the academic libraries management?

    Directory of Open Access Journals (Sweden)

    Liliana Laura Rega

    2006-12-01

    Full Text Available El Proyecto Alfa Biblioteca de Babel que reúne bibliotecas universitarias de América Latina y Europa comenzó en marzo de 2005 y prevé su conclusión en marzo de 2007. El presente trabajo intenta describir los objetivos y los resultados esperados, e informa las actividades realizadas por la Red Biblioteca de Babel. Finalmente se analizan las propuestas del proyecto en cuanto al rol de las bibliotecas universitarias, y su relación con la innovación en las prácticas pedagógicas.Biblioteca de Babel Alfa Project that assembles academic libraries from Latin America and Europe was approved on March, 2005 and its conclusion is foreseen on March, 2007. This article attempts to describe the aims and the expected results, and reports the activities of the Biblioteca de Babel Network. Finally it analizes the proposals of the project about the role of academic libraries and their relationship with innovations in pedagogical practices.

  18. Diagnóstico molecular da talassemia alfa+ (deleção–a3.7) em indivíduos com microcitose e/ou hipocromia atendidos no Hemocentro Dalton Barbosa Cunha em Natal, Rio Grande do Norte

    OpenAIRE

    Bezerra, Christiane Medeiros

    2009-01-01

    A talassemia alfa, uma das doenças monogênicas mais comuns no mundo, resulta de um desequilíbrio na síntese das cadeias alfa da hemoglobina devido, principalmente, à deleção de um ou ambos os genes da globina alfa, sendo a deleção -α3.7 a mais freqüente. A talassemia alfa, juntamente com a deficiência de ferro e a talassemia beta, representa uma importante causa de microcitose e hipocromia. Com o objetivo de diagnosticar e verificar a prevalência da talassemia alfa (-α3.7) em indivíduos com m...

  19. Diagnóstico molecular da talassemia alfa+ (deleção–a3.7) em indivíduos com microcitose e/ou hipocromia atendidos no Hemocentro Dalton Barbosa Cunha em Natal, Rio Grande do Norte

    OpenAIRE

    Bezerra, Christiane Medeiros

    2009-01-01

    A talassemia alfa, uma das doenças monogênicas mais comuns no mundo, resulta de um desequilíbrio na síntese das cadeias alfa da hemoglobina devido, principalmente, à deleção de um ou ambos os genes da globina alfa, sendo a deleção -α3.7 a mais freqüente. A talassemia alfa, juntamente com a deficiência de ferro e a talassemia beta, representa uma importante causa de microcitose e hipocromia. Com o objetivo de diagnosticar e verificar a prevalência da talassemia alfa (-α3.7) em indivíduos com m...

  20. The influence of a polymorphism in the gene encoding angiotensin converting enzyme (ACE on treatment outcomes in late-onset Pompe patients receiving alglucosidase alfa

    Directory of Open Access Journals (Sweden)

    Rena C. Baek

    2016-09-01

    Full Text Available Correlations between angiotensin-converting enzyme (ACE genotype (I/I, I/D, D/D, disease severity at baseline and response to enzyme replacement therapy (ERT were assessed in the Pompe disease Late-Onset Treatment Study (LOTS. No correlations were observed between ACE genotype and disease severity at baseline. However, D/D patients appeared to have a reduced response to alglucosidase alfa treatment than I/I or I/D patients, suggesting that ACE polymorphisms may influence the response to alglucosidase alfa treatment and warrants further investigation.

  1. Evidencia de la eficacia de los fármacos anti-TNF Alfa en el tratamiento de la espondilitis anquilosante

    OpenAIRE

    Montilla Salas, Juan Manuel

    2011-01-01

    OBJETIVO Establecer la evidencia de los estudios clínicos sobre la eficacia de las terapias anti-TNF alfa para el tratamiento de la espondilitis anquilosante (EA). MÉTODOS Se realizó una búsqueda con los diferentes fármacos anti-NTF alfa actualmente utilizados en terapia de la espondilitis anquilosante (Infiximab, Etanercept y Adalimumab). La revisión bibliográfica se realizó en Medline, Embase y la librería Cochrane para los estudios controlados y randomizados publicados hasta 1-enero-2005. ...

  2. Associação entre deficiência de alfa-1-antitripsina e a gravidade da fibrose cística

    OpenAIRE

    2005-01-01

    OBJETIVO: Verificar a distribuição dos genótipos da alfa-1-antitripsina e correlacionar com a gravidade da doença pulmonar em pacientes fibrocísticos. MÉTODO: Estudo clínico-laboratorial de corte transversal, com 70 pacientes fibrocísticos do Hospital Universitário da UNICAMP. Os fibrocísticos tiveram diagnóstico confirmado clínica e laboratorialmente. A gravidade da fibrose cística foi avaliada pelo escore de Shwachman. Todos os pacientes foram analisados para os alelos S e Z de alfa-1-antit...

  3. Uso de la tierra y diversidades alfa, beta y gamma de diplópodos en la cuenca del río Otún, Colombia

    OpenAIRE

    2010-01-01

    Objetivo: Determinar la relación entre los cambios promovidos por la intervención humana en ecosistemas y grosistemas y la diversidad alfa, beta y gamma de Diplopoda de la cuenca media del río Otún. Materiales y métodos: Se utilizó un diseño sistemático estratificado con la selección de siete ventanas y 16 puntos de muestreo. Se separaron los diplópodos en familias y morfotipos para calcular la diversidad alfa, beta y gamma relacionada con la heterogeneidad de usos del terreno. Resultados: Se...

  4. Factor de necrosis tumoral alfa en una población infanto-juvenil con sobrepeso

    Directory of Open Access Journals (Sweden)

    Teresita del R. Carrizo

    2013-08-01

    Full Text Available El sobrepeso infantil está asociado a sobrepeso/obesidad en la edad adulta. El tejido adiposo en obesos produce una cantidad incrementada de citoquinas proinflamatorias como el factor de necrosis tumoral alfa (TNF-a, ejerciendo un efecto deletéreo sobre la función vascular. El objetivo de este trabajo fue evaluar niveles de TNF-a en una población infantojuvenil con sobrepeso y su relación con otras variables. Se estudiaron 30 niños con sobrepeso (12 varones de edades entre 8-13 años, se midió circunferencia de cintura (CC e índice de masa corporal (IMC y fueron comparados con 20 controles de edad y sexo semejantes. Se consideró criterio de inclusión un IMC = 85 < 95 percentilo para edad y sexo. En ambos grupos se determinó: glucemia en ayunas (método glucosa oxidasa, insulina plasmática (ECLIA, fibrinógeno (Fg, método de Clauss, proteína C reactiva ultrasensible (uPCR, método inmunoturbidimétrico, TNF-a (ELISA, perfil lipídico (métodos enzimáticos, eritrosedimentación y se calculó el índice HOMA. Los datos se expresaron como mediana y rango intercuartil y con el coeficiente de Spearman se investigaron las correlaciones entre variables, considerándose significativo un p < 0.05. Los niveles de TNF-a fueron mayores en los sujetos con sobrepeso [15.4 (13.2-24.0 vs. 12.7 (11.2-14.8 pg/ml; p = 0.028]. También resultaron más elevados los valores de Fg, insulina plasmática, índice HOMA, uPCR y triglicéridos. El TNF-a se correlacionó con la CC (r = 0.654; p = 0.021. Los niveles elevados de TNF-a, uPCR y Fg encontrados confirman un estado proinflamatorio asociado a obesidad abdominal en la población estudiada.

  5. Estimadores de consistencia interna en las investigaciones en salud: el uso del coeficiente alfa

    Directory of Open Access Journals (Sweden)

    Franciele Cascaes da Silva

    Full Text Available La producción académica ha aumentado en el área de la salud, exigiendo cada vez más calidad en las publicaciones de gran impacto. Una de las formas de considerar la calidad es por medio de procedimientos que aumentan la consistencia del análisis de los datos, como la confiabilidad, que dependiendo del tipo de datos, puede ser evaluada por diferentes coeficientes, en especial el coeficiente alfa. Basados en lo anterior, la presente revisión reúne sistemáticamente artículos científicos producidos en los últimos cinco años, que de manera metodológica hicieron uso psicométrico del coeficiente α como un estimador de consistencia interna y de confiabilidad en procesos de construcción, adaptación y validación de instrumentos. La identificación de los estudios fue realizada sistemáticamente en las bases de datos Biomed Central Journals, Google Scholar, Web of Science, Wiley Online Library, Medline via Pubmed, Scielo, Scopus, Journals@Ovid, BMJ y Springer por medio del Portal de Periódicos CAPES, utilizando criterios de inclusión y exclusión. El análisis de los datos fue realizado por medio de triangulación, análisis de contenido y análisis descriptivo. Se obtuvo que la mayoría de los estudios fueron realizados principalmente en Irán (f=3, España (f=2 y Brasil (f=2, estos estudios tuvieron como objetivo testar las propiedades psicométricas de instrumentos, siendo que ocho estudios utilizaron el coeficiente α para evaluar la confiabilidad y nueve para evaluar la consistencia interna. Todos los estudios fueron clasificados como investigaciones metodológicas al analizar sus objetivos. Adicionalmente, cuatro estudios también fueron clasificados como correlacionales y uno como descriptivo-correlacional. Se puede concluir que a pesar de que el coeficiente α es ampliamente utilizado como uno de los principales parámetros para la evaluación de consistencia interna de instrumentos de medición del tipo cuestionario en el

  6. Estimadores de consistencia interna en las investigaciones en salud: el uso del coeficiente alfa

    Directory of Open Access Journals (Sweden)

    Franciele Cascaes da Silva

    2015-01-01

    Full Text Available La producción académica ha aumentado en el área de la salud, exigiendo cada vez más calidad en las publicaciones de gran impacto. Una de las formas de considerar la calidad es por medio de procedimientos que aumentan la consistencia del análisis de los datos, como la confiabilidad, que dependiendo del tipo de datos, puede ser evaluada por diferentes coeficientes, en especial el coeficiente alfa. Basados en lo anterior, la presente revisión reúne sistemáticamente artículos científicos producidos en los últimos cinco años, que de manera metodológica hicieron uso psicométrico del coeficiente α como un estimador de consistencia interna y de confiabilidad en procesos de construcción, adaptación y validación de instrumentos. La identificación de los estudios fue realizada sistemáticamente en las bases de datos Biomed Central Journals, Google Scholar, Web of Science, Wiley Online Library, Medline via Pubmed, Scielo, Scopus, Journals@Ovid, BMJ y Springer por medio del Portal de Periódicos CAPES, utilizando criterios de inclusión y exclusión. El análisis de los datos fue realizado por medio de triangulación, análisis de contenido y análisis descriptivo. Se obtuvo que la mayoría de los estudios fueron realizados principalmente en Irán (f=3, España (f=2 y Brasil (f=2, estos estudios tuvieron como objetivo testar las propiedades psicométricas de instrumentos, siendo que ocho estudios utilizaron el coeficiente α para evaluar la confiabilidad y nueve para evaluar la consistencia interna. Todos los estudios fueron clasificados como investigaciones metodológicas al analizar sus objetivos. Adicionalmente, cuatro estudios también fueron clasificados como correlacionales y uno como descriptivo-correlacional. Se puede concluir que a pesar de que el coeficiente α es ampliamente utilizado como uno de los principales parámetros para la evaluación de consistencia interna de instrumentos de medición del tipo cuestionario en el

  7. Arecibo pulsar survey using ALFA. III. Precursor survey and population synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Swiggum, J. K.; Lorimer, D. R.; McLaughlin, M. A.; Bates, S. D.; Senty, T. R. [Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506 (United States); Champion, D. J.; Lazarus, P. [Max-Planck-Institut für Radioastronomie, D-53121 Bonn (Germany); Ransom, S. M. [NRAO, Charlottesville, VA 22903 (United States); Brazier, A.; Chatterjee, S.; Cordes, J. M. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Hessels, J. W. T. [ASTRON, Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Nice, D. J. [Department of Physics, Lafayette College, Easton, PA 18042 (United States); Ellis, J.; Allen, B. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee WI 53211 (United States); Bhat, N. D. R. [Center for Astrophysics and Supercomputing, Swinburne University, Hawthorn, Victoria 3122 (Australia); Bogdanov, S.; Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Crawford, F. [Department of Physics and Astronomy, Franklin and Marshall College, Lancaster, PA 17604-3003 (United States); Deneva, J. S. [Arecibo Observatory, HC3 Box 53995, Arecibo, PR 00612 (United States); and others

    2014-06-01

    The Pulsar Arecibo L-band Feed Array (PALFA) Survey uses the ALFA 7-beam receiver to search both inner and outer Galactic sectors visible from Arecibo (32° ≲ ℓ ≲ 77° and 168° ≲ ℓ ≲ 214°) close to the Galactic plane (|b| ≲ 5°) for pulsars. The PALFA survey is sensitive to sources fainter and more distant than have previously been seen because of Arecibo's unrivaled sensitivity. In this paper we detail a precursor survey of this region with PALFA, which observed a subset of the full region (slightly more restrictive in ℓ and |b| ≲ 1°) and detected 45 pulsars. Detections included 1 known millisecond pulsar and 11 previously unknown, long-period pulsars. In the surveyed part of the sky that overlaps with the Parkes Multibeam Pulsar Survey (36° ≲ ℓ ≲ 50°), PALFA is probing deeper than the Parkes survey, with four discoveries in this region. For both Galactic millisecond and normal pulsar populations, we compare the survey's detections with simulations to model these populations and, in particular, to estimate the number of observable pulsars in the Galaxy. We place 95% confidence intervals of 82,000 to 143,000 on the number of detectable normal pulsars and 9000 to 100,000 on the number of detectable millisecond pulsars in the Galactic disk. These are consistent with previous estimates. Given the most likely population size in each case (107,000 and 15,000 for normal and millisecond pulsars, respectively), we extend survey detection simulations to predict that, when complete, the full PALFA survey should have detected 1000{sub −230}{sup +330} normal pulsars and 30{sub −20}{sup +200} millisecond pulsars. Identical estimation techniques predict that 490{sub −115}{sup +160} normal pulsars and 12{sub −5}{sup +70} millisecond pulsars would be detected by the beginning of 2014; at the time, the PALFA survey had detected 283 normal pulsars and 31 millisecond pulsars, respectively. We attribute the deficiency in normal pulsar

  8. Alfa247®: Un modelo de aprendizaje diferenciado para la enseñanza del Nordic Walking

    Directory of Open Access Journals (Sweden)

    Rodolfo Iván Martínez Lemos

    2010-03-01

    Full Text Available La técnica alfa y el método de los 7 pasos constituyen un modelo de aprendizaje diferenciado para la enseñanza del Nordic Walking (NW. NW consiste en caminar con bastones especialmente diseñados y utilizando una técnica precisa que moviliza una gran parte de la masa muscular total y tiene efectos beneficiosos probados sobre la salud. Alfa247® hace posible que cualquier persona, con independencia de su nivel de habilidad o condición física, pueda familiarizarse y aprender la técnica de caminar con bastones. Este nuevo concepto de movimiento saludable está todavía dando sus primeros pasos en España y es probable que en un futuro próximo pueda jugar un papel importante dentro del currículo de la Educación Física Escolar, como ya ha hecho en otros países del entorno.

  9. Baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF)

    Science.gov (United States)

    McMurray, John J.V.; Anand, Inder S.; Diaz, Rafael; Maggioni, Aldo P.; O'Connor, Christopher; Pfeffer, Marc A.; Solomon, Scott D.; Tendera, Michal; van Veldhuisen, Dirk J.; Albizem, Moetaz; Cheng, Sunfa; Scarlata, Debra; Swedberg, Karl; Young, James B.; Amuchastegui, M.; Belziti, C.; Bluguermann, J.; Caccavo, M.; Cartasegna, L.; Colque, R.; Cuneo, C.; Fernandez, A.; Gabito, A.; Goicochea, R.; Gonzalez, M.; Gorosito, V.; Grinfeld, L.; Hominal, M.; Kevorkian, R.; Litvak Bruno, M.; Llanos, J.; Mackinnon, I.; Manuale, O.; Marzetti, E.; Nul, D.; Perna, E.; Riccitelli, M.; Sanchez, A.; Santos, D.; Schygiel, P.; Toblli, J.; Vogel, D.; Aggarwal, A.; Amerena, J.; De Looze, F.; Fletcher, P.; Hare, D.; Ireland, M.; Krum, H.; Lattimore, J.; Marwick, T.; Sindone, A.; Thompson, P.; Waites, J.; Altenberger, J.; Ebner, C.; Lenz, K.; Pacher, R.; Poelzl, G.; Charlier, F.; de Ceuninck, M.; De Keulenaer, G.; Dendale, P.; Maréchal, P.; Mullens, W.; Thoeng, J.; Vanderheyden, M.; Vanhaecke, J.; Weytjens, C.; Wollaert, B.; Albuquerque, D.; Almeida, D.; Aspe y Rosas, J.; Bocchi, E.; Bordignon, S.; Clausell, N.; Kaiser, S.; Leaes, P.; Martins Alves, S.; Montera, M.; Moura, L.; Pereira de Castro, R.; Rassi, S.; Reis, A.; Saraiva, J.; Simões, M.; Souza Neto, J.; Teixeira, M.; Benov, H.; Chompalova, B.; Donova, T.; Georgiev, P.; Gotchev, D.; Goudev, A.; Grigorov, M.; Guenova, D.; Hergeldjieva, V.; Ivanov, D.; Kostova, E.; Manolova, A.; Marchev, S.; Nikolov, F.; Popov, A.; Raev, D.; Tzekova, M.; Czarnecki, W.; Giannetti, N.; Haddad, H.; Heath, J.; Huynh, T.; Lepage, S.; Liu, P.; Lonn, E.; Ma, P.; Manyari, D.; Moe, G.; Parker, J.; Pesant, Y.; Rajda, M.; Ricci, J.; Roth, S.; Sestier, F.; Sluzar, V.; Sussex, B.; Vizel, S.; Antezana, G.; Bugueno, C.; Castro, P.; Conejeros, C.; Manriquez, L.; Martinez, D.; Potthoff, S.; Stockins, B.; Vukasovic, J.; Gregor, P.; Herold, M.; Jerabek, O.; Jirmar, R.; Kuchar, R.; Linhart, A.; Podzemska, B.; Soucek, M.; Spac, J.; Spacek, R.; Vodnansky, P.; Bronnum-Schou, J.; Clemmensen, K.; Egstrup, K.; Jensen, G.; Kjoller-Hansen, L.; Kober, L.; Markenvard, J.; Rokkedal, J.; Skagen, K.; Torp-Pedersen, C.; Tuxen, C.; Videbak, L.; Laks, T.; Vahula, V.; Harjola, V.; Kettunen, R.; Kotila, M.; Bauer, F.; Cohen Solal, A.; Coisne, D.; Davy, J.; De Groote, P.; Dos Santos, P.; Funck, F.; Galinier, M.; Gibelin, P.; Isnard, R.; Neuder, Y.; Roul, G.; Sabatier, R.; Trochu, J.; Anker, S.; Denny, S.; Dreykluft, T.; Flesch, M.; Genth-Zotz, S.; Hambrecht, R.; Hein, J.; Jeserich, M.; John, M.; Kreider-Stempfle, H.; Laufs, U.; Muellerleile, K.; Natour, M.; Sandri, M.; Schäufele, T.; von Hodenberg, E.; Weyland, K.; Winkelmann, B.; Tse, H.; Yan, B.; Barsi, B.; Csikasz, J.; Dezsi, C.; Edes, I.; Forster, T.; Karpati, P.; Kerekes, C.; Kis, E.; Kosa, I.; Lupkovics, G.; Nagy, A.; Preda, I.; Ronaszeki, A.; Tomcsanyi, J.; Zamolyi, K.; Agarwal, D.; Bahl, V.; Bordoloi, A.; Chockalingam, K.; Chopda, M.; Chopra, V.; Dugal, J.; Ghaisas, N.; Ghosh, S.; Grant, P.; Hiremath, S.; Iyengar, S.; Jagadeesa Subramania, B.; Jain, P.; Joshi, A.; Khan, A.; Mullasari, A.; Naik, S.; Oomman, A.; Pai, V.; Pareppally Gopal, R.; Parikh, K.; Patel, T.; Prakash, V.; Sastry, B.; Sathe, S.; Sinha, N.; Srikanthan, V.; Subburamakrishnan, P.; Thacker, H.; Wander, G.; Admon, D.; Katz, A.; Klainman, E.; Lewis, B.; Marmor, A.; Moriel, M.; Mosseri, M.; Shotan, A.; Weinstein, J.; Zimlichman, R.; Agostoni, P.; Albanese, M.; Alunni, G.; Bini, R.; Boccanelli, A.; Bolognese, L.; Campana, C.; Carbonieri, E.; Carpino, C.; Checco, L.; Cosmi, F.; D'Angelo, G.; De Cristofaro, M.; Floresta, A.; Fucili, A.; Galvani, M.; Ivleva, A.; Marra, S.; Musca, G.; Peccerillo, N.; Perrone Filardi, P.; Picchio, E.; Russo, T.; Scelsi, L.; Senni, M.; Tavazzi, L.; Erglis, A.; Jasinkevica, I.; Kakurina, N.; Veze, I.; Volans, E.; Bagdonas, A.; Berukstis, E.; Celutkiene, J.; Dambrauskaite, A.; Jarasuniene, D.; Luksiene, D.; Rudys, A.; Sakalyte, G.; Sliaziene, S.; Aguilar-Romero, R.; Cardona-Muñoz, E.; Castro-Jimenez, J.; Chavez-Herrera, J.; Chuquiure Valenzuela, E.; De la Pena, G.; Herrera, E.; Leiva-Pons, J.; Lopez Alvarado, A.; Mendez Machado, G.; Ramos-Lopez, G.; Basart, D.; Buijs, E.; Cornel, J.; de Leeuw, M.; Dijkgraaf, R.; Dunselman, P.; Freericks, M.; Hamraoui, K.; Lenderlink, T.; Linssen, G.; Lodewick, P.; Lodewijks, C.; Lok, D.; Nierop, P.; Ronner, E.; Somsen, A.; van Dantzig, J.; van der Burgh, P.; van Kempen, L.; van Vlies, B.; Voors, A.; Wardeh, A.; Willems, F.; Dickstein, K.; Gundersen, T.; Hole, T.; Thalamus, J.; Westheim, A.; Dabrowski, M.; Gorski, J.; Korewicki, J.; Kuc, K.; Miekus, P.; Musial, W.; Niegowska, J.; Piotrowski, W.; Podolec, P.; Polonski, L.; Ponikowski, P.; Rynkiewicz, A.; Szelemej, R.; Trusz-Gluza, M.; Ujda, M.; Wojciechowski, D; Wysokinski, A.; Camacho, A.; Fonseca, C.; Monteiro, P.; Apetrei, E.; Bruckner, I.; Carasca, E.; Coman, I.; Datcu, M.; Dragulescu, S.; Ionescu, P.; Iordachescu-Petica, D.; Manitiu, I.; Popa, V.; Pop-Moldovan, A.; Radoi, M.; Stamate, S.; Tomescu, M.; Vita, I.; Aroutiounov, G.; Ballyuzek, M.; Bart, B.; Churina, S.; Glezer, M.; Goloshchekin, B.; Ivleva, A.; Kobalava, Z.; Kostenko, V.; Lopatin, Y.; Martynov, A.; Orlov, V.; Semernin, E.; Shogenov, Z.; Sidorenko, B.; Skvortsov, A.; Storzhakov, G.; Sulimov, V.; Talibov, O.; Tereshenko, S.; Tsyrline, V.; Zadionchenko, V.; Zateyshchikov, D.; Dzupina, A.; Hranai, M.; Kmec, J.; Micko, K.; Murin, J.; Pella, D.; Sojka, G.; Spisak, V.; Vahala, P.; Vinanska, D.; Badat, A.; Bayat, J.; Dawood, S.; Delport, E.; Ellis, G.; Garda, R.; Klug, E.; Mabin, T.; Naidoo, D.; Pretorius, M.; Ranjith, N.; Van Zyl, L.; Weich, H.; Anguita, M.; Berrazueta, J.; Bruguera i Cortada, J.; de Teresa, E.; Gómez Sánchez, M.; González Juanatey, J.; Gonzalez-Maqueda, I.; Jordana, R.; Lupon, J.; Manzano, L.; Pascual Figal, D.; Pulpón, L.; Recio, J.; Ridocci Soriano, F.; Rodríguez Lambert, J.; Roig Minguell, E.; Roig Minguell, E.; Romero, J.; Valdovinos, P.; Klintberg, L.; Kronvall, T.; Lycksell, M.; Morner, S.; Rydberg, E.; Swedberg, K.; Timberg, I.; Wikstrom, G.; Moccetti, T.4; Ashok, J.; Banerjee, P.; Carr-White, G.; Cleland, J.; Connolly, E.; Francis, M.; Greenbaum, R.; Kadr, H.; Lindsay, S.; McMurray, J.; Megarry, S.; Memon, A.; Murdoch, D.; Senior, R.; Squire, I.; Tan, L.; Witte, K.; Adams, K.; Adamson, P.; Adler, A.; Altschul, L.; Altschuller, A.; Amirani, H.; Anand, I.; Andreou, C.; Ansari, M.; Antonishen, M.; Banchs, H.; Banerjee, S.; Banish, D.; Bank, A.; Barbagelata, A.; Barnard, D.; Bellinger, R.; Benn, A.; Berk, M.; Berry, B.; Bethala, V.; Bilazarian, S.; Bisognano, J.; Bleyer, F.; Blum, M.; Boehmer, J.; Bouchard, A.; Boyle, A.; Bozkurt, B.; Brown, C.; Burlew, B.; Burnham, K.; Butler, J.; Call, J.; Cambier, P.; Cappola, T.; Carlson, R.; Chandler, B.; Chandra, R.; Chandraratna, P.; Chernick, R.; Colan, D.; Colfer, H.; Colucci, W.; Connelly, T.; Costantini, O.; Dadkhah, S.; Dauber, I.; Davis, J.; Davis, S.; Denning, S.; Drazner, M.; Dunlap, S.; Egbujiobi, L.; Elkayam, U.; Elliott, J.; El-Shahawy, M.; Essandoh, L.; Ewald, G.; Fang, J.; Farhoud, H.; Felker, G.; Fernandez, J.; Festin, R.; Fishbein, G.; Florea, V.; Flores, E.; Floro, J.; Gabris, M.; Garg, M.; Gatewood, R.; Geller, M.; Ghali, J.; Ghumman, W.; Gibbs, G.; Gillespie, E.; Gilmore, R.; Gogia, H.; Goldberg, L.; Gradus-Pizlo, I.; Grainger, T.; Gudmundsson, G.; Gunawardena, D.; Gupta, D.; Hack, T.; Hall, S.; Hamroff, G.; Hankins, S.; Hanna, M.; Hargrove, J.; Haught, W.; Hauptman, P.; Hazelrigg, M.; Herzog, C.; Heywood, J.; Hill, T.; Hilton, T.; Hirsch, H.; Hunter, J.; Ibrahim, H.; Imburgia, M.; Iteld, B.; Jackson, B.; Jaffrani, N.; Jain, D.; Jain, A.; James, M.; Jimenez, J.; Johnson, E.; Kale, P.; Kaneshige, A.; Kapadia, S.; Karia, D.; Karlsberg, R.; Katholi, R.; Kerut, E.; Khoury, W.; Kipperman, R.; Klapholz, M.; Kosinski, E.; Kozinn, M.; Kraus, D.; Krueger, S.; Krum, H.; Kumar, S.; Lader, E.; Lee, C.; Levy, W.; Lewis, E.; Light-McGroary, K.; Loh, I.; Lombardi, W.; Machado, C.; Maislos, F.; Mancini, D.; Markus, T.; Mather, P.; McCants, K.; McGrew, F.; McLaurin, B.; McMillan, E.; McNamara, D.; Meyer, T.; Meymandi, S.; Miller, A.; Minami, E.; Modi, M.; Mody, F.; Mohanty, P.; Moscoso, R.; Moskowitz, R.; Moustafa, M.; Mullen, M.; Naz, T.; Noonan, T.; O'Brien, T.; Oellerich, W.; Oren, R.; Pamboukian, S.; Pereira, N.; Pitt, W.; Porter, C.; Prabhu, S.; Promisloff, S.; Ratkovec, R.; Richardson, R.; Ross, A.; Saleh, N.; Saltzberg, M.; Sarkar, S.; Schmedtje, J.; Schneider, R.; Schuyler, G.; Shanes, J.; Sharma, A.; Siegel, C.; Siegel, R.; Silber, D.; Singh, V.; Singh, N.; Singh, J.; Sklar, J.; Small, R.; Smith, A.; Smith, E.; Smith, E.; Smull, D.; Sotolongo, R.; Staniloae, C.; Stapleton, D.; Steele, P.; Stehlik, J.; Stein, M.; Tang, W.; Thadani, U.; Torre-Amoine, G.; Trichon, B.; Tsai, C.; Tummala, R.; Van Bakel, A.; Vicari, R.; Vijay, N.; Vijayaraghavan, K.; Vittorio, T.; Vossler, M.; Wagoner, L.; Wallis, D.; Ward, N.; Widmer, M.; Wight, J.; Wilkins, C.; Williams, C.; Williams, G.; Winchester, M.; Winkel, E.; Wittmer, B.; Wood, D.; Wormer, D.; Wright, R.; Xu, Z.; Yasin, M.; Zolty, R.

    2013-01-01

    Aims This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes. Methods and results Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate <60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L. Conclusion The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity. PMID:23329651

  10. Pegylated interferon alfa-2b alone or in combination with lamivudine for HBeAg-positive chronic hepatitis B : a randomised trial

    NARCIS (Netherlands)

    Janssen, Harry L A; van Zonneveld, Monika; Senturk, Hakan; Zeuzem, Stefan; Akarca, Ulus S; Cakaloglu, Yilmaz; Simon, Christopher; So, Thomas M K; Gerken, Guido; de Man, Robert A; Niesters, Hubert G M; Zondervan, Pieter; Hansen, Bettina; Schalm, Solko W

    2005-01-01

    BACKGROUND: Treatment of HBeAg-positive patients with chronic hepatitis B is not effective in most. A combination of immunomodulatory pegylated interferon alfa-2b and antiviral lamivudine might improve the rate of sustained response. METHODS: 307 HBeAg-positive patients with chronic hepatitis B were

  11. Alfa Laval to meet the ballast water challenge%阿法拉伐应对压载水的挑战

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Alfa Laval, the market leader in separation, heat transfer and freshwater generation, is widening its offering of solutions for environmental protection. The company hereby announces that a potent technology for dealing with unwanted organisms in ballast water will be commercially available as early as 2006.

  12. Effectiveness of interferon alfa on incidence of hepatocellular carcinoma and decompensation in cirrhosis type C. European Concerted Action on Viral Hepatitis (EUROHEP)

    DEFF Research Database (Denmark)

    Fattovich, G; Giustina, G; Degos, F

    1997-01-01

    The role of interferon alfa treatment in improving morbidity endpoints in patients with chronic hepatitis C infection is currently under debate. The aim of this study was to evaluate the effectiveness of interferon in preventing hepatocellular carcinoma and decompensation in cirrhosis type C....

  13. Long-term results of the randomized phase III trial EORTC 18991 of adjuvant therapy with pegylated interferon alfa-2b versus observation in resected stage III melanoma

    NARCIS (Netherlands)

    A.M.M. Eggermont (Alexander); S. Suciu (Stefan); A. Testori (Alessandro); M. Santinami (Mario); W.H.J. Kruit (Wim); J. Marsden; C.J.A. Punt (Cornelis); F. Salès (François); R. Dummer (Reinhard); C. Robert (Caroline); D. Schadendorf (Dirk); P. Patel (Poulam); G. de Schaetzen (Gaetan); A. Spatz (Alan); U. Keilholz (Ulrich)

    2012-01-01

    textabstractPurpose: Adjuvant pegylated interferon alfa-2b (PEG-IFN-α-2b) was approved for treatment of resected stage III melanoma in 2011. Here, we present long-term follow-up results of this pivotal trial. Patients and Methods: In all, 1,256 patients with resected stage III melanoma were randomly

  14. Prospective exploratory muscle biopsy, imaging, and functional assessment in patients with late-onset Pompe disease treated with alglucosidase alfa: The EMBASSY Study

    NARCIS (Netherlands)

    A.T. van der Ploeg (Ans); Carlier, P.G. (Pierre G.); Carlier, R.-Y. (Robert-Yves); Kissel, J.T. (John T.); B. Schoser; Wenninger, S. (Stephan); Pestronk, A. (Alan); Barohn, R.J. (Richard J.); Dimachkie, M.M. (Mazen M.); Goker-Alpan, O. (Ozlem); Mozaffar, T. (Tahseen); Pena, L.D.M. (Loren D.M.); Simmons, Z. (Zachary); V. Straub; Guglieri, M. (Michela); Young, P. (Peter); Boentert, M. (Matthias); Baudin, P.-Y. (Pierre-Yves); S.C.A. Wens (Stephan); Shafi, R. (Raheel); Bjartmar, C. (Carl); B. Thurberg

    2016-01-01

    textabstractBackground Late-onset Pompe disease is characterized by progressive skeletal myopathy followed by respiratory muscle weakness, typically leading to loss of ambulation and respiratory failure. In this population, enzyme replacement therapy (ERT) with alglucosidase alfa has been shown to

  15. Stability is maintained in adults with Gaucher disease type 1 switched from velaglucerase alfa to eliglustat or imiglucerase: A sub-analysis of the eliglustat ENCORE trial.

    Science.gov (United States)

    Pleat, Rebecca; Cox, Timothy M; Burrow, T Andrew; Giraldo, Pilar; Goker-Alpan, Ozlem; Rosenbloom, Barry E; Croal, Laura R; Underhill, Lisa H; Gaemers, Sebastiaan J M; Peterschmitt, M Judith

    2016-12-01

    Gaucher disease type 1 is an autosomal recessive disorder caused by deficient activity of the lysosomal enzyme acid β-glucosidase resulting in accumulation of glucosylceramide and clinical manifestations of anemia, thrombocytopenia, hepatosplenomegaly, and skeletal disease. The historic standard of care is intravenous recombinant enzyme therapy with imiglucerase. Eliglustat, an oral substrate reduction therapy, is a first-line treatment for adults with Gaucher disease type 1 who have a compatible CYP2D6-metabolizer phenotype (≈ 95% of patients). The 12-month ENCORE trial (NCT00943111) found eliglustat non-inferior to imiglucerase in maintaining stability in adult Gaucher patients previously stabilized after ≥ 3 years of enzyme therapy (imiglucerase or velaglucerase alfa). This post-hoc analysis examined safety and efficacy in the 30 ENCORE patients who were receiving velaglucerase alfa at study entry and were randomized to eliglustat (n = 22) or imiglucerase (n = 8). Efficacy and safety in velaglucerase alfa-transitioned patients were consistent with the full ENCORE trial population; 90% of patients switched to eliglustat and 88% of patients switched to imiglucerase met the composite endpoint (stable hemoglobin concentration, platelet count, spleen volume, and liver volume). Clinical stability was maintained for 12 months in Gaucher disease type 1 patients in the ENCORE trial who switched from velaglucerase alfa to either eliglustat or imiglucerase.

  16. Hemoglobinas AS/alfa talassemia: importância diagnóstica Hemoglobins AS/alpha thalassemia: diagnostic importance

    Directory of Open Access Journals (Sweden)

    Renata Tomé-Alves

    2000-12-01

    Full Text Available Portadores de traço falciforme (hemoglobina AS associados a talassemia alfa apresentam alterações na morfologia dos eritrócitos, normalmente ausentes nos heterozigotos para esta variante de hemoglobina. A interação entre hemoglobina S e talassemia alfa tem sido descrita como um dos fatores responsáveis pela melhora no quadro clínico de portadores homozigotos de hemoglobina S (anemia falciforme, diminuindo os episódios de crises de falcização. Os mecanismos genéticos desta influência são avaliados em análises moleculares dos genes da globina humana. Com o objetivo de verificar a presença de talassemia alfa em portadores de hemoglobina S em heterozigose, com presença de anemia, encaminhados ao Laboratório de Hemoglobinas do Departamento de Biologia da UNESP, de São José do Rio Preto, analisamos 1.002 amostras de sangue com traço falciforme, no período de 1990 a 1998. As amostras foram colhidas com EDTA como anticoagulante, após prévia autorização dos portadores. Para o diagnóstico laboratorial as amostras de sangue foram submetidas a procedimentos eletroforéticos em pH alcalino e ácido e pesquisa citológica de hemoglobina H. Os procedimentos eletroforéticos confirmaram a presença de hemoglobina AS. A pesquisa citológica evidenciou a presença de talassemia alfa. Deste total analisado, 16 (1,59 % amostras de sangue apresentaram a associação entre hemoglobina AS e alfa talassemia, sendo que duas eram de indivíduos de uma mesma família. Os resultados obtidos nos direcionaram a sugerir aos laboratórios de rotina que realizem a pesquisa de alfa talassemia entre os portadores de hemoglobina AS, com presença de anemia, para verificar a interação com talassemia alfa, fornecendo assim aos portadores informação importante sobre seu perfil hematológico.Sickle Cell disease is a generic term for a group of genetic disorders characterized by the predominance of hemoglobin S. These disorders include Sickle Cell anemia

  17. An open-label clinical trial to investigate the efficacy and safety of corifollitropin alfa combined with hCG in adult men with hypogonadotropic hypogonadism.

    Science.gov (United States)

    Nieschlag, Eberhard; Bouloux, Pierre-Marc G; Stegmann, Barbara J; Shankar, R Ravi; Guan, Yanfen; Tzontcheva, Anjela; McCrary Sisk, Christine; Behre, Hermann M

    2017-03-07

    Hypogonadotropic hypogonadism (HH) in men results in insufficient testicular function and deficiencies in testosterone and spermatogenesis. Combinations of human chorionic gonadotropin (hCG) and recombinant follicle-stimulating hormone (recFSH) have been successful in the treatment of HH. Corifollitropin alfa is a long-acting FSH-analog with demonstrated action in women seeking infertility care. The aim of this study was to investigate the efficacy and safety of corifollitropin alfa combined with hCG to increase testicular volume and induce spermatogenesis in men with HH. This was a Phase III, multi-center, open-label, single-arm trial of corifollitropin alfa in azoospermic men aged 18 to 50 years with HH. After 16 weeks of pretreatment of 23 subjects with hCG alone, 18 subjects with normalized testosterone (T) levels who remained azoospermic entered the 52-week combined treatment phase with hCG twice-weekly and 150 μg corifollitropin alfa every other week. The increase in testicular volume (primary efficacy endpoint) and induction of spermatogenesis resulting in a sperm count ≥1 × 10(6)/mL (key secondary efficacy endpoint) during 52 weeks of combined treatment were assessed. Safety was evaluated by the presence of anti-corifollitropin alfa antibodies and the occurrence of adverse events (AEs). Mean (±SD) testicular volume increased from 8.6 (±6.09) mL to 17.8 (±8.93) mL (geometric mean fold increase, 2.30 [95% CI: 2.03, 2.62]); 14 (77.8%) subjects reached a sperm count ≥1 × 10(6)/mL. No subject developed confirmed anti-corifollitropin alfa antibodies during the trial. Treatment was generally well tolerated. Corifollitropin alfa 150 μg administrated every other week combined with twice-weekly hCG for 52 weeks increased testicular volume significantly, and induced spermatogenesis in >75% of men with HH who had remained azoospermic after hCG treatment alone. ClinicalTrials.gov: NCT01709331 .

  18. O uso da drotrecogina alfa ativada na prática clínica e as atuais evidências Drotrecogin alfa activated in clinical practice and the current evidences

    Directory of Open Access Journals (Sweden)

    Márcio Soares

    2008-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O debate sobre a segurança e eficácia da drotrecogina alfa (DrotAA encontra-se na ordem do dia, principalmente, em função dos resultados negativos observados em ensaios clínicos subseqüentes ao PROWESS e do impacto econômico no sistema de saúde relacionado ao custo elevado do fármaco. O objetivo deste estudo foi rever os principais estudos sobre a utilização da DrotAA em pacientes com sepse grave, com ênfase nas questões ligadas a sua eficácia e segurança. CONTEÚDO: Foram selecionados artigos sobre a utilização da DrotAA em pacientes com sepse publicados nos últimos dez anos no MedLine. Os seguintes unitermos foram utilizados: activated protein C; drotrecogin alfa; sepsis; septic shock; Xigris®. Estudos referenciados nos artigos selecionados na busca também foram utilizados. CONCLUSÕES: As taxas de letalidades e as complicações hemorrágicas associadas com o uso do fármaco foram maiores em grandes estudos observacionais do que aquelas descritas previamente nos ensaios clínicos. A luz dos resultados atualmente disponíveis, o uso da DrotAA deve ser reconsiderado até que novos ensaios clínicos possam subsidiar com informações adicionais sobre eficácia, segurança e na identificação dos subgrupos de pacientes com sepse grave que porventura possam ter benefício com o uso deste medicamento. A DrotAA deve servir de exemplo para que haja maior cautela com a rápida transposição de evidências ainda em construção para recomendações e diretrizes de tratamento de pacientes com sepse grave.BACKGROUND AND OBJECTIVES: The debate on efficacy and patient safety related to the use of drotrecogin alfa (DrotAA is timely, principally due to the negative results observed in clinical studies performed after the PROWESS study, and the economic cost-related impact of the drug on the healthcare system. The aim of this study was to review the main studies on the use of DrotAA in patients with severe

  19. Diversidad alfa y beta de la comunidad de reptiles en el complejo cenagoso de Zapatosa, Colombia

    Directory of Open Access Journals (Sweden)

    Guido Fabián Medina-Rangel

    2011-06-01

    Full Text Available La diversidad es una propiedad de las comunidades, permite describir, caracterizar y entender el funcionamiento de los ecosistemas. Para estudiar la riqueza, abundancia y el recambio de especies de reptiles entre hábitats circundantes al complejo cenagoso de Zapatosa, se realizaron cuatro salidas de campo (noviembre de 2006 y octubre de 2007. Se invirtieron 640h/hombre de muestreo repartido en cinco tipos de hábitat: bosque casmófito, bosque seco, bosque de ribera, palmar y sabana arbolada. Se encontraron 847 individuos de 48 especies, la familia más rica fue Colubridae, se registraron cinco especies endémicas y ocho con algún grado de amenaza en conservación a nivel nacional. El hábitat más diverso fue el bosque de ribera. La representatividad del muestreo en total y para cada hábitat fue superior al 80%, con excepción del palmar (Alfa and beta diversity of reptilian assemblages in Zapatosa wetland complex, Colombia. Diversity is a property of community that can described, characterized, and understood according to the functioning of ecosystems. To study the richness and local abundance and species replacement between habitats around the Zapatosa’s wetland complex (El Cesar Department, I carried out four field trips between November of 2006 and October of 2007. A total of 640 sampling hours/man analyzed five habitat types chasmophyte forest, dry forest, riparian forest, palm-grove and tree-lined savanna; with the exception of the palm-grove sampled at its 75%, the others were sampled up to their 80%. I found 847 reptiles that were distributed in 48 species. The group with the highest number of species was Colubridae with 14, followed by Gekkonidae with five. Five endemic species and eight with some conservation threat grade at a national level a re reported. The riparian forest was the richest and most abundant habitat with 34 species and 196 individuals. For each habitat, Colubridae had the highest number of species, followed by

  20. Estudios sobre alfa-amilasa en saliva como marcador de estrés en la especie humana y otras especies animales= Studies on salivary alpha-amylase as a maker of stress in human and different animal species

    OpenAIRE

    Fuentes Rubio, María

    2014-01-01

    OBJETIVOS 1. Evaluar el uso de la alfa amilasa salivar como marcador de estrés usando técnicas tradicionales (ensayos enzimáticos) en humana, usando como modelo experimental a estudiantes de veterinaria que tenían que realizar una presentación oral de un trabajo en lengua extranjera. 2. Evaluar el uso de la alfa amilasa salivar como marcador de estrés usando técnicas tradicionales (ensayos enzimáticos) en cerdos. 3. Implementar nuevos enfoques para la medición de la alfa-amilasa e...

  1. Long-term endurance and safety of elosulfase alfa enzyme replacement therapy in patients with Morquio A syndrome.

    Science.gov (United States)

    Hendriksz, Christian J; Parini, Rossella; AlSayed, Moeenaldeen D; Raiman, Julian; Giugliani, Roberto; Solano Villarreal, Martha L; Mitchell, John J; Burton, Barbara K; Guelbert, Norberto; Stewart, Fiona; Hughes, Derralynn A; Berger, Kenneth I; Slasor, Peter; Matousek, Robert; Jurecki, Elaina; Shaywitz, Adam J; Harmatz, Paul R

    2016-09-01

    Long-term efficacy and safety of elosulfase alfa enzyme replacement therapy were evaluated in Morquio A patients over 96weeks (reaching 120weeks in total from pre-treatment baseline) in an open-label, multi-center, phase III extension study. During this extension of a 24-week placebo-controlled phase III study, all patients initially received 2.0mg/kg elosulfase alfa either weekly or every other week, prior to establishment of 2.0mg/kg/week as the recommended dose, at which point all patients received weekly treatment. Efficacy measures were compared to baseline of the initial 24-week study, enabling analyses of changes over 120weeks. In addition to performing analyses for the entire intent-to-treat (ITT) population (N=173), analyses were also performed for a modified per-protocol (MPP) population (N=124), which excluded patients who had orthopedic surgery during the extension study or were non-compliant with the study protocol (as determined by ≥20% missed infusions). Six-minute walk test (6MWT) was the primary efficacy measure; three-minute stair climb test (3MSCT) and normalized urine keratan sulfate (uKS) were secondary efficacy measures. Mean (SE) change from baseline to Week 120 in 6MWT distance was 32.0 (11.3)m and 39.9 (10.1)m for patients receiving elosulfase alfa at 2.0mg/kg/week throughout the study (N=56) and 15.1 (7.1)m and 31.7 (6.8)m in all patients combined, regardless of dosing regimen, for the ITT and MPP populations, respectively. Further analyses revealed that durability of 6MWT improvements was not impacted by baseline 6MWT distance, use of a walking aid, or age. Mean (SE) change at Week 120 in the 3MSCT was 5.5 (1.9) and 6.7 (2.0)stairs/min for patients receiving elosulfase alfa at 2.0mg/kg/week throughout the study and 4.3 (1.2) and 6.8 (1.3)stairs/min in all patients combined, regardless of dosing regimen, for the ITT and MPP populations, respectively Across all patients, mean (SE) change at Week 120 in normalized uKS was -59.4 (1.8)% and

  2. Enzyme Replacement Therapy With Elosulfase Alfa Decreases Storage of Glycosaminoglycan in White Blood Cells of Patients With Morquio A Syndrome

    Directory of Open Access Journals (Sweden)

    Guilherme Baldo PhD

    2015-02-01

    Full Text Available Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome is a lysosomal storage disorder caused by a deficient N-acetylgalactosamine-6-sulfate sulfatase activity, leading to cellular storage of undegraded keratan sulfate. Recently enzyme replacement therapy (ERT was approved for MPS IVA, but some of ERT effects are still unknown. In the present study, we aimed to evaluate the efficacy of elosulfase alfa upon glycosaminoglycan (GAG storage in peripheral blood white blood cells of patients with MPS IVA treated for 6 months, comparing samples from patients who received weekly infusions of enzyme (ERT-W versus infusions every other week (ERT-EOW versus placebo. A significant reduction in GAG storage was observed in both ERT-treated groups, with weekly ERT showing slightly better performance than ERT-EOW.

  3. Systemic lupus erythematosus following virological response to peginterferon alfa-2b in a transplanted patient with chronic hepatitis C recurrence

    Institute of Scientific and Technical Information of China (English)

    Francesca Lodato; Giuseppe Mazzella; Maria Rosa Tamé; Antonio Colecchia; Chiara Racchini; Francesco Azzaroli; Antonia D'Errico; Silvia Casanova; Antonio Pinna; Enrico Roda

    2006-01-01

    Autoimmune manifestations are common both in patients chronically infected by hepatitis C virus, and in patients transplanted for non-autoimmune diseases. A correlation between interferon based treatment and autoimmune diseases or the development of autoantibodies is well established in non-transplanted patients, but few data are available about transplanted patients. It is unclear whether interferon may increase the incidence of acute cellular rejection and there are few reports on the development of atypical autoimmune manifestations during post-liver transplantation interferon or pegylated interferon treatment. We describe a case of systemic lupus erythematosus following treatment with pegylated interferon alfa-2b in a transplanted patient with recurrence of chronic hepatitis C. Our experience suggest that pegylated interferon may induce autoimmune diseases in the immunosuppressed host, different from acute cellular rejection and call for a great attention to possible autoimmune disorders development during interferon based treatments in liver transplanted patients.

  4. Deficiência de alfa-1 antitripsina: diagnóstico e tratamento Alpha-1 antitrypsin deficiency: diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    Aquiles A Camelier

    2008-07-01

    Full Text Available A deficiência de alfa-1 antitripsina é um distúrbio genético de descoberta recente e que ocorre com freqüência comparável à da fibrose cística. Resulta de diferentes mutações no gene SERPINA1 e tem diversas implicações clínicas. A alfa-1 antitripsina é produzida principalmente no fígado e atua como uma antiprotease. Tem como principal função inativar a elastase neutrofílica, impedindo a ocorrência de dano tecidual. A mutação mais freqüentemente relacionada à doença clínica é o alelo Z, que determina polimerização e acúmulo dentro dos hepatócitos. O acúmulo e a conseqüente redução dos níveis séricos de alfa-1 antitripsina determinam, respectivamente, doença hepática e pulmonar, sendo que esta se manifesta principalmente sob a forma de enfisema de aparecimento precoce, habitualmente com predomínio basal. O diagnóstico envolve a detecção de níveis séricos reduzidos de alfa-1 antitripsina e a confirmação fenotípica. Além do tratamento usual para doença pulmonar obstrutiva crônica, existe atualmente uma terapia específica com infusão de concentrados de alfa-1 antitripsina. Essa terapia de reposição, aparentemente segura, ainda não teve a eficácia clínica definitivamente comprovada, e o custo-efetividade também é um tema controverso e ainda pouco abordado. Apesar da sua importância, não existem dados epidemiológicos brasileiros a respeito da prevalência da doença ou da freqüência de ocorrência dos alelos deficientes. O subdiagnóstico também tem sido uma importante limitação tanto para o estudo da doença quanto para o tratamento adequado dos pacientes. Espera-se que a criação do Registro Internacional de Alfa-1 venha a resolver essas e outras importantes questões.Alpha-1 antitrypsin deficiency is a recently identified genetic disease that occurs almost as frequently as cystic fibrosis. It is caused by various mutations in the SERPINA1 gene, and has numerous clinical

  5. Daclatasvir vs telaprevir plus peginterferon alfa/ribavirin for hepatitis C virus genotype 1

    Science.gov (United States)

    Jacobson, Ira; Zeuzem, Stefan; Flisiak, Robert; Knysz, Brygida; Lueth, Stefan; Zarebska-Michaluk, Dorota; Janczewska, Ewa; Ferenci, Peter; Diago, Moises; Zignego, Anna Linda; Safadi, Rifaat; Baruch, Yaacov; Abdurakhmanov, Dzhamal; Shafran, Stephen; Thabut, Dominique; Bruck, Rafael; Gadano, Adrian; Thompson, Alexander James; Kopit, Justin; McPhee, Fiona; Michener, Tracy; Hughes, Eric A; Yin, Philip D; Noviello, Stephanie

    2016-01-01

    AIM: To evaluate daclatasvir vs telaprevir, each combined with peginterferon alfa-2a/ribavirin (pegIFN/RBV), in treatment-naive hepatitis C virus (HCV) genotype (GT) 1-infected patients. METHODS: In this phase 3, randomized, open-label, noninferiority study, 602 patients were randomly assigned (2:1) to daclatasvir vs telaprevir, stratified by IL28B rs12979860 host genotype (CC vs non-CC), cirrhosis status (compensated cirrhosis vs no cirrhosis), and HCV GT1 subtype (GT1a vs GT1b). Patients were selected by study inclusion criteria from a total of 793 enrolled patients. Patients received daclatasvir 60 mg once daily or telaprevir 750 mg 3 times daily plus pegIFN/RBV. Daclatasvir recipients received 24 wk of daclatasvir plus pegIFN/RBV; those without an extended rapid virologic response (eRVR; undetectable HCV-RNA at weeks 4 and 12) received an additional 24 wk of pegIFN/RBV. Telaprevir-treated patients received 12 wk of telaprevir plus pegIFN/RBV followed by 12 (with eRVR) or 36 (no eRVR) wk of pegIFN/RBV. The primary objective was to compare for noninferiority of sustained virologic response rates at posttreatment week 12 (SVR12) in GT1b-infected patients. Key secondary objectives were to demonstrate that the rates of anemia (hemoglobin < 10 g/dL) and rash-related events, through week 12, were lower with daclatasvir + pegIFN/RBV than with telaprevir + pegIFN/RBV among GT1b-infected patients. Resistance testing was performed using population-based sequencing of the NS5A region for all patients at baseline, and for patients with virologic failure or relapse and HCV-RNA ≥ 1000 IU/mL, to investigate any link between NS5A polymorphisms associated with daclatasvir resistance and virologic outcome. RESULTS: Patient demographics and disease characteristics were generally balanced across treatment arms; however, there was a higher proportion of black/African Americans in the daclatasvir groups (6.0% and 8.2% in the GT1b and GT1a groups, respectively) than in the

  6. Cost-effectiveness analysis of adding low dose ribavirin to peginterferon alfa-2a for treatment of chronic hepatitis C infected thalassemia major patients in iran.

    Science.gov (United States)

    Mehrazmay, Alireza; Alavian, Seyed Moayed; Moradi-Lakeh, Maziar; Mokhtari Payam, Mahdi; Hashemi-Meshkini, Amir; Behnava, Bita; Miri, Seyyed Mohammad; Karimi Elizee, Pegah; Tabatabaee, Seyed Vahid; Keshvari, Maryam; Bagheri Lankarani, Kamran

    2013-01-01

    The prevalence of hepatitis C in Iran is 1% and 18% in general population and thalassemia patients respectively. The cost effectiveness analysis of adding Ribavirin to Peginterferon alfa-2a (PEG IFN alfa-2a) as a combination treatment strategy of chronic hepatitis C in thalassemia patients in comparison with monotherapy could help clinicians and policy makers to provide the best treatment for the patients. In this study we aimed to assess whether adding Ribavirin to PEG IFN alfa-2a is a cost effective strategy in different genotypes and different subgroups of 280 patients with chronic hepatitis C infection from the perspective of society in Iranian setting. A cost effectiveness analysis including all costs and outcomes of treatments for chronic hepatitis C infected thalassemia major patients was conducted. We constructed a decision tree of treatment course in which a hypothetical cohort of 100 patients received "PEG IFN alfa-2a" or "Peg IFN alfa-2a plus Ribavirin." The cost analysis was based on cost data for 2008 and we used 9300 Iranian Rials (IR Rial) as exchange rate declared by the Iranian Central Bank on that time to calculating costs by US Dollar (USD). To evaluate whether a strategy is cost effective, one time and three times of GDP per capita were used as threshold based on recommendation of the World Health Organization. The Incremental Cost Effectiveness Ratio (ICER) for combination therapy in genotype-1 and genotypes non-1 subgroups was 2,673 and 19,211 US dollars (USD) per one Sustain Virological Response (SVR), respectively. In low viral load and high viral load subgroups, the ICER was 5,233 and 14,976 USD per SVR, respectively. The calculated ICER for combination therapy in subgroup of patients with previously resistant to monotherapy was 13,006 USD per SVR. Combination therapy in previously resistant patients to combination therapy was a dominant strategy. Adding low dose of Ribavirin to PEG IFN alfa-2a for treatment of chronic hepatitis C patients

  7. Health-related quality of life in patients with high-risk melanoma randomised in the Nordic phase 3 trial with adjuvant intermediate-dose interferon alfa-2b

    DEFF Research Database (Denmark)

    Brandberg, Y; Aamdal, S; Bastholt, Lars;

    2012-01-01

    To compare health-related quality of life (HRQoL) and side-effects in patients with high-risk melanoma participating in a randomised phase III trial of adjuvant interferon alfa-2b (IFN).......To compare health-related quality of life (HRQoL) and side-effects in patients with high-risk melanoma participating in a randomised phase III trial of adjuvant interferon alfa-2b (IFN)....

  8. Assessment of the Results of the Multicenter Randomized Acute Leukemia French Association (ALFA) 9803 Trial%法国急性白血病协会(ALFA)9803多中心随机临床试验结果的评价

    Institute of Scientific and Technical Information of China (English)

    江滨; 凌伟

    2009-01-01

    @@ 1文献来源 Gardin C, Turlure P, Fagot T, et al. Postremission treatment of elderly patients with acute myeloid leukemia in first complete remission after intensive induction chemotherapy: Results of the multicenter randomized Acute Leukemia French Association (ALFA) 9803 trial [J]. Blood, 2007, 109(12) : 5129-5135.

  9. Peginterferon alpha-2a is associated with higher sustained virological response than peginterferon alfa-2b in chronic hepatitis C: systematic review of randomized trials

    DEFF Research Database (Denmark)

    Awad, Tahany; Thorlund, Kristian; Hauser, Goran;

    2010-01-01

    A combination of weekly pegylated interferon (peginterferon) alpha and daily ribavirin represents the standard of care for the treatment of chronic hepatitis C according to current guidelines. It is not established which of the two licensed products (peginterferon alpha-2a or peginterferon alfa-2b......) is most effective. We performed a systematic review of head-to-head randomized trials to assess the benefits and harms of the two treatments. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and LILACS through July 2009. Using standardized forms, two reviewers independently......-2a is associated with higher SVR than peginterferon alfa-2b. However, the paucity of evidence on adverse events curbs the decision to definitively recommend one peginterferon over the other, because any potential benefit must outweigh the risk of harm....

  10. Elementos regulatórios responsáveis pelo controle da estabilidade do mRNA de alfa tubulina de Trypanosoma cruzi

    OpenAIRE

    Patricia Rosa de Araujo

    2007-01-01

    Um mecanismo de auto-regulação dos mRNAs de alfa e beta tubulina em Trypanosoma cruzi afeta a meia vida desses transcritos ao longo do ciclo de vida do parasita. Enquanto epimastigotas apresentam altos níveis dos mRNAs de tubulina, um excesso da proteína não polimerizada em amastigotas está relacionada com o decréscimo dos níveis dos seus mRNAs. Esta diminuição não é resultado de mudanças na transcrição e sim devido a redução da meia vida dos mRNAs de alfa e beta tubulina. Através do tratamen...

  11. The Holocene Climate Linkage between Low Latitude Area and North Atlantic:Case study on element and element ratios of Huguangyan Maar lake%全新世低纬地区古环境演化与北大西洋之间的联系——以湖光岩玛珥湖元素和元素比值记录为例

    Institute of Scientific and Technical Information of China (English)

    吴旭东; 沈吉; 汪勇

    2011-01-01

    Holocene paleoenvironment evolution history of the Huguangyan area,paleoenvironment revolution at Huguangyan area since 11 000 cal a BP can be divided into four stages: stage Ⅰ,11 000~7 800 cal a BP,the climate was warm and wet;stage Ⅱ,7 800~5 600 cal a BP,the climate became cold and dry rapidly;stage Ⅲ,5 600~2 000 cal a BP,it was relative warm and wet,but not as warm as early Holocene;stage Ⅳ,2 000 cal a BP as yet,the climate became dry gradually.The results show that early Holocene is the Holocene optimum,the climate became relatively dry since the mid Holocene.This pattern is consistent with pollen record also from Huguangyan maar lake and other records from low latitude area of the northern hemisphere,which indicates the global nature of the orbital forcing of the Holocene monsoon.There are affiliations and differences between cold events reflected by Huguangyan Maar lake sediment and North Atlantic ice-rafted debris,which suggests that climate shift at low latitude area has certain linkage with North Atlantic area.Low latitude processes,such as monsoon and ENSO,are influencing factors that affected Holocene evolution at Huguangyan area.Holocene paleoenvironment evolution at low latitude is the result of superposition of low latitude processes and high latitude processes,which makes the mechanism of climate change at low latitude area more complicated.%通过湖光岩玛珥湖沉积物高分辨率的Fe/Mn比值、Rb/Sr比值、Sr元素强度和550℃烧失量的研究,重建了湖光岩地区全新世以来的古环境演化历史,即:早全新世是气候适宜期,气候温暖湿润,中、晚全新世开始气候逐渐干旱化。这种气候演化模式体现了全新世季风演化的全球性。湖光岩玛珥湖沉积物反映的全新世以来的冷暖变化事件与北大西洋浮冰碎屑记录之间既存在联系又存在差异。这说明在全新世背景下,低纬地区的古气候演化与北大西洋存在一定程度的联系。低纬地区

  12. Impact of elosulfase alfa in patients with morquio A syndrome who have limited ambulation: An open‐label, phase 2 study

    Science.gov (United States)

    Mengel, Eugen; Geberhiwot, Tarekegn; Muschol, Nicole; Hendriksz, Christian J.; Burton, Barbara K.; Jameson, Elisabeth; Berger, Kenneth I.; Jester, Andrea; Treadwell, Marsha; Sisic, Zlatko; Decker, Celeste

    2016-01-01

    Efficacy and safety of elosulfase alfa enzyme replacement therapy (ERT) were assessed in an open‐label, phase 2, multi‐national study in Morquio A patients aged ≥5 years unable to walk ≥30 meters in the 6‐min walk test. Patients received elosulfase alfa 2.0 mg/kg/week intravenously for 48 weeks. Efficacy measures were functional dexterity, pinch/grip strength, mobility in a modified timed 25‐foot walk, pain, quality of life, respiratory function, and urine keratan sulfate (KS). Safety/tolerability was also assessed. Fifteen patients received elosulfase alfa, three patients discontinued ERT due to adverse events (two were grade 3 drug‐related adverse events, the other was not drug‐related), and two patients missed >20% of planned infusions; 10 completed treatment through 48 weeks and received ≥80% of planned infusions (Modified Per Protocol [MPP] population). The study population had more advanced disease than that enrolled in other trials. From baseline to week 48, MPP data showed biochemical efficacy (urine KS decreased 52.4%). The remaining efficacy results were highly variable due to challenges in test execution because of severe skeletal and joint abnormalities, small sample sizes, and clinical heterogeneity among patients. Eight patients showed improvements in one or more outcome measures; several patients indicated improvements not captured by the study assessments (e.g., increased energy, functional ability). The nature of adverse events was similar to other elosulfase alfa studies. This study illustrates the considerable challenges in objectively measuring impact of ERT in very disabled Morquio A patients and highlights the need to examine results on an individual basis. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc. PMID:27774754

  13. Impact of elosulfase alfa in patients with morquio A syndrome who have limited ambulation: An open-label, phase 2 study.

    Science.gov (United States)

    Harmatz, Paul R; Mengel, Eugen; Geberhiwot, Tarekegn; Muschol, Nicole; Hendriksz, Christian J; Burton, Barbara K; Jameson, Elisabeth; Berger, Kenneth I; Jester, Andrea; Treadwell, Marsha; Sisic, Zlatko; Decker, Celeste

    2017-02-01

    Efficacy and safety of elosulfase alfa enzyme replacement therapy (ERT) were assessed in an open-label, phase 2, multi-national study in Morquio A patients aged ≥5 years unable to walk ≥30 meters in the 6-min walk test. Patients received elosulfase alfa 2.0 mg/kg/week intravenously for 48 weeks. Efficacy measures were functional dexterity, pinch/grip strength, mobility in a modified timed 25-foot walk, pain, quality of life, respiratory function, and urine keratan sulfate (KS). Safety/tolerability was also assessed. Fifteen patients received elosulfase alfa, three patients discontinued ERT due to adverse events (two were grade 3 drug-related adverse events, the other was not drug-related), and two patients missed >20% of planned infusions; 10 completed treatment through 48 weeks and received ≥80% of planned infusions (Modified Per Protocol [MPP] population). The study population had more advanced disease than that enrolled in other trials. From baseline to week 48, MPP data showed biochemical efficacy (urine KS decreased 52.4%). The remaining efficacy results were highly variable due to challenges in test execution because of severe skeletal and joint abnormalities, small sample sizes, and clinical heterogeneity among patients. Eight patients showed improvements in one or more outcome measures; several patients indicated improvements not captured by the study assessments (e.g., increased energy, functional ability). The nature of adverse events was similar to other elosulfase alfa studies. This study illustrates the considerable challenges in objectively measuring impact of ERT in very disabled Morquio A patients and highlights the need to examine results on an individual basis. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.

  14. A cost-effectiveness evaluation comparing originator follitropin alfa to the biosimilar for the treatment of infertility

    Directory of Open Access Journals (Sweden)

    Gizzo S

    2016-12-01

    Full Text Available Salvatore Gizzo,1 Juan A Garcia-Velasco,2 Franca Heiman,3 Claudio Ripellino,3 Klaus Bühler4 1Department of Woman and Child Health, University of Padua, Padua, Italy; 2Department of Obstetrics and Gynecology, Rey Juan Carlos University Madrid, Madrid, Spain; 3IMS Health Information Solutions Italy Srl, Milan, Italy; 4Centre for Gynaecology, Endocrinology, and Reproductive Medicine, Ulm and Stuttgart, Germany Objectives: To perform a cost-effectiveness evaluation comparing the originator follitropin alfa (Gonal-f® to the biosimilar (Bemfola® in the Italian and Spanish contexts, with an assessment of the German and UK backgrounds. Methods: Starting from the study by Rettenbacher et al, a cost-effectiveness model was developed in the Italian and Spanish contexts. Clinical data on subjects, doses of gonadotropin, pregnancies, live-born children, and ovarian hyperstimulation syndrome were used to feed the model. Costs related to drugs, hospitalizations, specialist visits, and examinations were retrieved from Italian and Spanish tariffs. Gonadotropin acquisition costs for Germany and the UK were also taken into account to expand the economical assessment to the other countries. The evaluation was done based on the National Health Service perspective. Sensitivity analyses, both univariate and probabilistic, as long as scenario analyses, tested the robustness of the model. Results: Originator follicle-stimulating hormone (FSH costs were €3,663 and €6,387 in Italy and Spain, respectively, whereas biosimilar FSH costs were €3,483 and €6,342. The efficacy was found to be 0.52 for the originator and 0.47 for the biosimilar. The average cost per live birth was estimated to be €7,044 and €12,283 for the originator FSH and €7,411 and €13,494 for the biosimilar for Italy and Spain, respectively. Furthermore, the originator FSH generated an incremental cost-effectiveness ratio of €3,600 for Italy and €900 for Spain compared to the

  15. Influence of wool and thermo-binder fibers relative fractions on the adhesion of non-woven Alfa fibers reinforced unsaturated polyester hybrid composites

    Science.gov (United States)

    Amin Omri, Med; Triki, A.; Ben Hassen, Med; Arous, M.; Bulou, A.

    2016-10-01

    Alfa/wool/thermo-binder fibers hybrid composites were investigated in order to analyze adhesion state. Bearing in mind the chemical structure of wool and thermo-binder fibers, this study revealed a good compatibility between the reinforcement and the matrix. Dielectric measurements revealed the presence of two dielectric relaxations in the composite. The first relaxation was attributed to the α mode relaxation and the second one was associated with the conductivity noted for high temperature. This study allowed the analysis of the interfacial polarization effect using the Havrilliak-Negami model in the electric modulus formalism. The lowness of this relaxation intensity revealed a good adhesion of the fibers in the matrix. Differential Scanning Calorimetry (DSC) showed a slow decrease of the Tg glass transition temperature compared to the matrix, which could be explained by the existence of interactions between the fibers and the matrix. Vibrational analysis, based on FTIR measurements, showed a less hydrophilic character of Alfa fibers owing to a basic dissociation that occurs between the wool fibers and the water molecules associated with Alfa fibers. Furthermore, adhesion mechanism in the composite material was established by covalent and hydrogen bonds. Tensile testing performed on this composite confirmed that such adhesion was improved by increasing the thermo-binder fibers relative fraction.

  16. Antibodies that neutralize cellular uptake of elosulfase alfa are not associated with reduced efficacy or pharmacodynamic effect in individuals with Morquio A syndrome.

    Science.gov (United States)

    Melton, Andrew C; Soon, Russell K; Tompkins, Troy; Long, Brian; Schweighardt, Becky; Qi, Yulan; Vitelli, Catherine; Bagri, Anil; Decker, Celeste; O'Neill, Charles A; Zoog, Stephen J; Jesaitis, Lynne

    2017-01-01

    Many enzyme replacement therapies (ERTs) for lysosomal storage disorders use the cell-surface cation-independent mannose-6 phosphate receptor (CI-M6PR) to deliver ERTs to the lysosome. However, neutralizing antibodies (NAb) may interfere with this process. We previously reported that most individuals with Morquio A who received elosulfase alfa in the phase 3 MOR-004 trial tested positive for NAbs capable of interfering with binding to CI-M6PR ectodomain in an ELISA-based assay. However, no correlation was detected between NAb occurrence and clinical efficacy or pharmacodynamics. To quantify and better characterize the impact of NAbs, we developed a functional cell-based flow cytometry assay with a titer step that detects antibodies capable of interfering with elosulfase alfa uptake. Serum samples collected during the MOR-004 trial were tested and titers were determined. Consistent with earlier findings on NAb positivity, no correlations were observed between NAb titers and the clinical outcomes of elosulfase alfa-treated individuals with Morquio A.

  17. The efficacy and safety of adjuvant interferon-alfa therapy in the evolving treatment landscape for resected high-risk melanoma.

    Science.gov (United States)

    Trinh, Van Anh; Zobniw, Chrystia; Hwu, Wen-Jen

    2017-08-01

    Patients with resected stage II or III melanoma are at high risk of recurrence, with 5-year mortality rate of 40-60%. Adjuvant interferon-alfa has demonstrated a small RFS and OS benefit versus observation in this patient population. However, the adjuvant treatment landscape is evolving rapidly. Areas covered: This review aims to summarize the safety and efficacy profiles of adjuvant IFNα/PEG-IFNα, revisit the controversy surrounding its application, and reappraise its position in the rapidly changing treatment landscape of resected melanoma. A literature search using PubMed database was undertaken using search words melanoma, interferon-alfa, pegylated interferon-alfa, adjuvant therapy. Expert opinion: Currently, there is no international consensus regarding the optimal dosing schedule for adjuvant IFNα, but HD IFNα-2b remains the most widely used regimen. The AEs of HD IFNα-2b are substantial; however, toxicity management experience amassed over the past 2 decades has significantly improved safety. Many exciting studies are ongoing to examine the roles of immune checkpoint inhibitors and BRAF-targeted therapies in the adjuvant setting and will further delineate the role of adjuvant IFNα.

  18. Uso tópico do inteferon alfa-2b para neoplasia escamosa da superficie ocular em um caso de paciente com xeroderma pigmentoso

    Directory of Open Access Journals (Sweden)

    Nayara Queiroz Cardoso Pinto

    Full Text Available Resumo Relato de um caso clínico de Xeroderma Pigmentoso com carcinoma espinocelular de conjuntiva bilateral que apresentou regressão importante das dimensões tumorais com o uso de Interferon alfa-2b tópico. Relato de caso: Paciente feminina com Xeroderma Pigmentoso em estágio avançado, com ausência de pele sadia, tendo sido submetida a cerca de 60 exéreses de lesões de pele malignas. A paciente compareceu com tumoração conjuntival em ambos os olhos, correspondendo a carcinoma espinocelular de conjuntiva e neoplasia intraepitelial de conjuntiva em olho esquerdo. Devido as dificuldades cirúrgicas, alta taxa de recidiva e elevada probabilidade de formação de simbléfaro foi-se iniciado terapêutica com Interferon alfa-2beta 1.000.000 unidades tópico, obtendo-se bons resultados com importante regressão do tamanho da lesão e resolução dos sintomas. Conclusão: O uso tópico de interferon alfa-2beta em neoplasia escamosa de conjuntiva, mostrou-se uma boa opção terapêutica em situações de elevado risco cirúrgico e de complicações pós operatórias.

  19. 亚印太交汇区低纬上空不同层次大气臭氧的时空变化分析%Characteristics of temporal - spatial vertical distribution of atmospheric ozone over the low - latitude region of the joining area of Asia and Indian - Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    李琼; 郭世昌; 刘煜; 吕达仁; 段雪梅; 苏锦兰; 李慧晶

    2011-01-01

    利用ECMWF 195709~200208共45 a的多层臭氧质量混合比月平均资料,详细分析了亚印太交汇区(AIPO)低纬地带上空平流层、对流层各层次上臭氧浓度的分布特征.结果表明:①区域上空对流层、平流层及臭氧总量大尺度特征均显著,纬度带分布特征明显;②对流层和平流层臭氧各个季节变化趋势相反,平流层臭氧和臭氧总量各个季节变化趋势一致;同一层次夏季臭氧浓度变化趋势与其他3个季节变化趋势相反;③区域上空20~3 hPa是臭氧浓度的高值区,50~30 hPa臭氧平均变化幅度最大;④对流层臭氧距平变化在整个高度上较为一致,正、负距平随季节绕赤道做南、北半球摆动,且存在季节性突变;⑤赤道上空有明显从平流层上层随季节逐渐往较低层传播的臭氧正负距平现象.%Based on the multi - layered ozone mass mixing ratio monthly mean data derived from ECMWF during the periods of 195709—200208 , the distribution characteristics of stratosphere and troposphere atmospheric ozone concentration at all levels over the low - latitude region of the joining area of Asia and Indian - Pacific Ocean ( AIPO) , have been analyzed in detail. The results showed that: ①The tropospheric, stratospheric and total ozone over the region all reflect significant large - scale features with obvious latitude - belt distribution characteristic ; ② The variation trends of tropospheric and stratospheric ozone in all seasons are reverse, while stratospheric and total ozone are consistent. The ozone trend in summer is contrary to other three seasons at the same level; ③The vertical variation range of the high ozone concentration and the averaged ozone maximum are respectively exist in the 3-20 hPa and 50-30 hPa over the equator region;④ At the different levels, the anomaly change of tropospheric ozone is consistent. And the positive and negative anomalies demonstrate a southern -northern hemisphere

  20. 色谱分析条件对低纬度痕量长链烯酮温度指标应用可靠性的影响%CHROMATOGRAPHIC QUALIFICATIONS AND THEIR EFFECTS ON RELIABILITY OF LOW-LATITUDE TRACE LONG-CHAIN ALKENONE AS A TEMPERATURE INDICATOR

    Institute of Scientific and Technical Information of China (English)

    南青云; 李铁刚; 陈金霞; 孙晗杰

    2012-01-01

    Two main chromatographic qualifications, programmed temperature mode and carrier gas flow rate, were investigated for the analysis of trace alkenone from low-latitude continental shelf samples. The separability, test precision and repeatability under various gas chromatographic (GC) analytical circumstances were discussed. Our results show that chromatographic qualifications have great impacts on the a-nalysis of those trace alkenone. Traditional high GC programmed temperature ramps (PTR), which are adequate for ocean sediment samples, were confirmed no longer applicable for the analysis of the shelf samples highly diluted by terrigenous debris. Excellent separabilities for C37: x (C37:2 & C37:3) and the homolog compounds were obtained under Low PTR condition (1. 3℃/min at high temperature stage) , even for the samples in which the C37: 3alkenone content is extremely low (lng/g dry sediment, calculated sea surface temperature is near to 27 ℃). Furthermore, the test precision and repeatability are much better under low PTR. Our results also indicate that perfect separabilities and test precision are likely to be obtained under low carrier gas flow rate for those shelf sediment samples with low trace alkenone content.%通过对气相色谱仪分析低纬陆架痕量长链烯酮过程中的升温速率和栽气流速两个主要条件进行了探讨,对比了不同的程序升温速率和不同栽气流量条件下烯酮的分离效果和检测精确度及重现性.研究发现色谱分析条件对低纬度痕量长链烯酮的分析有显著的影响.当前广泛适用于中低纬度开放大洋沉积物样品的较高的程序升温方法难以对低纬度高陆源物质冲淡作用影响下的陆架海沉积物样品进行有效的分离分析.在接近UK37指标适用温度上限且C37∶3烯酮含量极低的情况下(1 ng/g干样,计算温度接近27℃),采用较低的程序升温速率分离C37∶3和C37∶2及后续化合物有利于获得良好的分离

  1. A HIGH-RESOLUTION PALYNOLOGICAL RECORD AND ITS PALEOENVIRONMENTAL INTERPRETATION IN THE LOW LATITUDE OF SOUTH CHINA SEA SINCE LAST DEGLACIATION%南海低纬地区末次冰消期以来高分辨率孢粉记录及古环境

    Institute of Scientific and Technical Information of China (English)

    张玉兰; 贾丽; 李珍; 戴璐

    2011-01-01

    根据南海低纬地区SA09-090孔高分辨率的孢粉记录,从下至上划分了4个孢粉组合带,依据孢粉成分的变化,重建了15 000 aBP以来的植被和气候变化历史.研究结果发现:冰消期早期(15.0~12.5 kaBP)研究区花粉主要来自当地出露的陆架,揭示出出露的陆架植被以热带低山雨林和低地雨林为主.海滨地区生长着茂盛的红树林,当时气温比现在低一些,但无明显变干现象.冰消期后期(12.5~10 kaBP)植被中低山雨林花粉增多,红树植物花粉减少,这说明此时海平面上升,气温也回升,花粉源区变远.全新世时(10 kaBP至今),花粉主要来源于婆罗洲和周围岛屿,植被以低山雨林和海滨红树植物为主,但花粉浓度大幅降低,只有冰消期早期的几分之一和十几分之一,这种花粉浓度降低说明海平面继续上升,研究区距离花粉源区越来越远.全新世中期时为热、湿的气候环境,后期与现今相近.%In accordance with the high resolution pollen record of the Core SA09-090,which was located in the low latitude of the South China Sea,four pollen zones have been distinguished in an ascending order. Inferred from the pollen composition in each zone, the history of vegetation evolution and climate change since 15 000 aBP was reconstructed. The research result shows that at the early stage of Last deglaciation(15.0 ~12. 5 kaBP), the pollen in the research area mainly came from the emerged continental shelf. The vegetation was mainly composed of tropical low-mountain and lowland rainforests. Mangroves bloomed on the coastal area. The temperature was a little lower than that of today, but there was no clear evidence of aridity. At the late stage of Last deglaciation(12.5~10 kaBP) ,the amount of pollen from lowland rainforest increased,and the amount of pollen from mangroves decreased. It indicates a sea level rise at that period,and the temperature rose too. The pollen source area was far away. At the

  2. 南海低纬地区15kaBP以来高分辨率孢粉记录及植被、气候演变%High-resolution palynological record and evolution of vegetation and climate in the low latitude of the South China Sea since 15 kaBP

    Institute of Scientific and Technical Information of China (English)

    张玉兰; 彭学超; 赵晶

    2011-01-01

    本文依据南海低纬地区SA09-090孔高分辨率的孢粉记录,从下至上划分了4个孢粉组合带,从孢粉成分的变化,重建了15kaBP以来的植被和气候变化历史.研究结果发现:15.0-12.5kaBP期间研究区花粉主要来自当地出露的陆架,揭示出出露的陆架植被类型是以热带低山雨林和低地雨林为主.海滨地区生长着茂盛的红树林,当时气温比现在低一些,但无明显变干现象.12-10kaBP期间植被中低山雨林花粉增多,红树植物花粉减少,这说明此时海平面上升,气温也回升,花粉源区变远.全新世时(10kaBP至今),花粉主要来源于加里曼丹岛和周围岛屿,植被以低山雨林和海滨红树植物为主,但花粉浓度大幅降低,这种花粉浓度降低说明海平面继续上升,研究区距离花粉源区越来越远.全新世中期时为热、湿的气候环境,后期与现今相近.%Based on the high resolution pollen record at the Core SA09-090, which was in the low latitude of the South China Sea, four pollen zones are distinguished in an ascending order. According to the pollen composition in each zone, the vegeta-tion evolution and climate change since lSkaBP is reconstructed. The research shows that at the stage of 15.0-12.5kaBP, the pollen in the research area mainly came from the continental shelf when it was above the sea level. This indicates that the vegetation on the continental shelf that was above the sea level was mainly tropical low-mountain rainforest and lowland rainforest. Many mangroves lived in the coastal area. The temperature was a little lower than today's, but there was no clear evidence of aridity. At the stage of 12-10kaBP, the amount of pollen from lowland rainforest increased, and the amount of pollen from the mangroves decreased. This indicates that the sea level rose in that period, and the temperature rose, too. The pollen source became far away. At the Holocene (10kaBP to now), the pollen mainly came from Borneo and the

  3. AlphaCI: un programa de cálculo de intervalos de confianza para el coeficiente alfa de Cronbach

    Directory of Open Access Journals (Sweden)

    Rubén Ledesma

    Full Text Available El coeficiente alfa de Cronbach es el modo más habitual de estimar la fiabilidad de pruebas basadas en Teoría Clásica de los Test. En dicha estimación, los investigadores usualmente omiten informar intervalos de confianza para el coeficiente, un aspecto no solo recomendado por los especialistas, sino también requerido explícitamente en las normas editoriales de algunas revistas especializadas. Esta situación puede atribuirse a que los métodos de estimación de intervalos de confianza son poco conocidos, además de no estar disponibles al usuario en los programas estadísticos más populares. Así, en este trabajo se presenta un programa desarrollado dentro del sistema estadístico ViSta que permite calcular intervalos de confianza basados en el enfoque clásico y mediante la técnica bootstrap. Se espera promover la inclusión de intervalos de confianza para medidas de fiabilidad, facilitando el acceso a las herramientas necesarias para su aplicación. El programa es gratuito y puede obtenerse enviando un mail de solicitud al autor del trabajo.

  4. Um imunoensaio rápido para a detecção de alfa-trembolona em urina bovina

    Directory of Open Access Journals (Sweden)

    Keila Maria Roncato Duarte

    2006-12-01

    Full Text Available O Brasil está entre os países que mantêm o uso de anabolizantes proibido, o que gera dificuldades muito grandes no monitoramento destas substâncias, uma vez que possui o maior rebanho bovino. Contudo, diversas substâncias são largamente utilizadas, entre as quais o acetato de trembolona. Com o consentimento do Ministério da Agricultura, Pecuária e Abastecimento, foram produzidos anticorpos policlonais para um teste baseado em ELISA ("enzyme linked immunosorbent assay" capazes de detectar acetato de trembolona na urina de bovinos tratados com trembolona. O teste apresentou baixo custo e de fácil execução para a detecção de alfa-trembolone, o principal metabólito na absorção do acetato de trembolona, liberado na urina dos animais. Os resultados foram similares aos obtidos com o "kit" comercial usado pelo Ministério da Agricultura, Pecuária e Abastecimento do Brasil.

  5. Comparing effects of Beractant and Poractant alfa in decreasing mortality rate due to respiratory distress syndrome in premature infants

    Directory of Open Access Journals (Sweden)

    Saeidi R

    2011-02-01

    Full Text Available "nBackground: Exogenous natural and synthetic surfactants is a rescue treatment for respiratory distress syndrome (RDS. The goals of the study were to compare the clinical response and side-effects of two frequently used surfactants, poractant alfa (Curosurf and beractant (Survanta, for the treatment of respiratory distress syndrome in preterm infants."n "nMethods: This clinical trial study was performed during a two-year period in the Neonatal Intensive Care Unit of Ghaem Hospital in Mashhad, Iran. Sample size calculated by a 95% confidence and power of 80, included 104 premature neonates, 74 in survanta and 30 in curosurf groups. The level of statistical significance was considered to be < 0.05."n "nResults: There were no statistically significant differences between the infants treated by survanta or cursurf groups regarding their mean gestational age (30.58 Vs. 29.00 weeks and birth weight (1388 Vs. 1330 g, (p=0.3 There were also no significant differences between the two groups regarding incidences of broncho- pulmonary dysplasia (BPD (40.5% Vs. 40%, intraventricular hemorrhage (IVH grades III/IV (13.5% Vs. 13.3%, pneumothorax (both 20%, patent ductus arteriosus (PDA (28/3% Vs. 20% or death (28% Vs. 26.6% on the 28th day postpartum."n "nConclusion: This study showed that survanta and curosurf had similar therapeutic effects in the treatment of neonatal respiratory distress syndrome.

  6. THE INFLUENCE OF ASOCIATED SUPPLEMENT OF ALFA AMYLASE AND XYLANASE ON THE RHEOLOGY OF DOUGH CONCEARNING ITS CONSTITOGRAPHICAL PARAMETERS

    Directory of Open Access Journals (Sweden)

    RODICA CHEREJI

    2013-07-01

    Full Text Available In this paper we determined the influence of associated supplement of alfa amylase and xylanase on the rheology of dough concearning its constitographical parameters : maximum pressure (Pr max, (mb and the absorbed water (Wa, %. The analysis on the consistograph were conducted for constant hydration at the consistency of 500 UF. Determinations were made on 4 types of flour and optimal dosages were found for each enzyme, after which we prepared the optimal dosage of the enzymes in the compund for flour F1 and F2 : P1-840000 U. SKB/100 kg flour +8100 U. FXU /100 kg flour, P2-840000 U. SKB/100 kg flour+16200 U. FXU, /100 kg flour , P3-840000 U. SKB/100 kg flour+24300 U. FXU/100 kg flour , and for F3 and F4 thus: P1-280000 U. SKB/100 kg flour +8100 U. FXU /100 kg flour, P2- 280000 U. SKB/100 kg flour+16200 U. FXU/100 kg flour, P3-280000 U. SKB/100 kg flour+24300 U. FXU/100 kg flour. Fungous α-amylase and xylanase were used in these concentrations to establish which one is more apropriate to be added in flour to obtain superior quality of bread: finer texture of the crumb, prolongation of the freashness of the bread, improvind the colour and flavour, emproving the slicing ability.

  7. Diferencias entre coeficientes alfa de Cronbach, con muestras y partes pequeñas: un programa VB

    Directory of Open Access Journals (Sweden)

    César Merino-Soto

    Full Text Available Se presenta un programa informático escrito en VB 6.0, para calcular la diferencia entre coeficientes de consistencia interna (alfa de Cronbach, obtenidos en muestras pequeñas independientes y/o con instrumentos que poseen un número también pequeño de partes o ítems. La comparación de coeficientes de fiabilidad permite identificar posibles diferencias en el tamaño del error de medición en los instrumentos comparados; esta metodología usa el enfoque de prueba de hipótesis, probando la hipótesis nula de igualdad de los coeficientes. Esta condición tiende a ser frecuente en la práctica clínica entre psicólogos y profesiones aliadas, e inclusive en las fases de construcción de instrumentos de medición, por ejemplo en muestras piloto. La técnica aplicada proviene del trabajo de Feldt y Kim (2006, y ofrece una viable e interesante propuesta metodológica que expande el análisis de la fiabilidad de instrumentos de medición psicológicos y educativos. Se presenta las características de su uso, y se discuten las condiciones apropiadas de aplicación.

  8. Study of forward elastic $pp$ scattering at $\\sqrt{s}=8\\text{ TeV}$ with the ALFA detector

    CERN Document Server

    Stark, Simon Holm; Hansen, Jørgen Beck

    The elastic $pp$ scattering data analyzed in this thesis was taken at the LHC with the ALFA detector at $\\sqrt{s}=8\\text{ TeV}$ with a $\\beta^*=1\\text{ km}$ collision optics which gave access to the Coulomb-Nuclear-Interference region. An improved procedure was used to fit the observed number of elastic events as a function of the four-momentum transfer with a simulation based on theoretical expectations including experimental effects. The data can not exclude any of the investigated parametrizations for the modulus of the nuclear amplitude. The fit results for the total $pp$ cross section, $\\sigma_\\text{tot}$, and the ratio of the real to imaginary forward elastic scattering amplitude, $\\rho$, are: \\begin{align*} \\sigma_\\text{tot} &= 99.1\\pm 0.3 \\text{ (stat.)}\\pm1.6\\text{ (syst.)} \\text{ mb}\\;,\\\\ \\rho &= 0.166\\pm0.017\\text{ (stat.)}\\pm0.019\\text{ (syst.)}\\;, \\end{align*} which are in agreement with previous measurements. As part of the analysis, the detector distance to the beam was determined with ...

  9. Proton-Proton Central Exclusive Pion Production at $\\sqrt{13}$ TeV with the ALFA and ATLAS Detector

    CERN Document Server

    Bols, Emil Sorensen

    The cross section for proton-proton central exclusive dipion production, $pp\\rightarrow p + \\pi^+ \\pi^- + p$, has been measured at the center of mass energy $\\sqrt{s}=13\\mathrm{TeV}$, where double Pomeron exchange is expected to dominate. The LHC was used to create the central diffractive events, and all the final state particles were measured using the ATLAS and ALFA detector. After correcting for detector inefficiencies and proton acceptance using the Donnachie-Landshoff model with $\\alpha'=0.126\\mathrm{GeV}^{-2}$ and $\\epsilon=0.085$, the cross section was found to be: \\begin{equation} \\sigma_{pp\\rightarrow p+\\pi^+\\pi^-+p}=18.754\\pm0.048(\\mathrm{stat}.)\\pm0.770(\\mathrm{syst}.)\\mu\\mathrm{b} , \\quad |\\eta_{\\pi}| 100\\mathrm{MeV} \\end{equation} The invariant mass spectrum of the pions has been analyzed in order to extract the widths and masses of the $f_0(500)$, $f_0(980)$, $f_2(1275)$ and $f_0(1500)$ mesons. A correlation between the two outgoing protons has been observed, which is not in agreement with Pom...

  10. Lichen Planus Induced by Pegylated Interferon Alfa-2a Therapy in a Patient Monitored for Delta Hepatitis

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    Safak Kaya

    2015-01-01

    Full Text Available Interferons are used for treatment of chronic hepatitis B. They can induce or exacerbate some skin disorders, such as lichen planus. In this study, as we know, we presented the first case developing lichen planus while receiving interferon treatment due to delta hepatitis. A 31-year-old male patient presented to our outpatient clinic with HBsAg positivity. With his analyses, HBV DNA was negative, anti-delta total was positive, ALT was 72 U/L (upper limit 41 U/L, and platelet was 119 000/mm3. He was therefore started on subcutaneous pegylated interferon alfa-2a therapy at 180 mcg/week for delta hepatitis. At month 4 of therapy, the patient developed diffuse eroded lace-like lesions in oral mucosa, white plaques on lips, and itchy papular lesions in the hands and feet. Lichen planus was considered by the dermatology clinic and topical treatment (mometasone furoate was given. The lesions persisted at month 5 of therapy and biopsy samples were obtained from oral mucosal lesions and interferon dose was reduced to 135 mcg/week. Biopsy demonstrated nonkeratinized stratified squamous epithelium; epithelial acanthosis, spongiosis, and apoptotic bodies were observed in the epidermis and therefore lichen planus was considered. At month 6 of therapy, lesions did not improve and even progressed and interferon treatment was therefore discontinued.

  11. Unidades fototérmicas e temperatura-base inferior de frutos de Mangueira Alfa, na Baixada Cuiabana Photothermal units and lower base temperature for alfa mango fruit on the Baixada Cuiabana

    Directory of Open Access Journals (Sweden)

    Marcelo Paes de Barros

    2010-06-01

    Full Text Available O objetivo deste trabalho foi determinar a temperatura-base inferior (Tb a partir da unidade fototérmica (UF para o cultivo experimental de manga Alfa sob condições de cerrado. Foram utilizados dados diários da temperatura do ar disponibilizados pela Estação Agrometeorológica Padre Ricardo Remetter, localizada em Santo Antônio do Leverger-MT (15,8° S e 56,1° W, 140 m, e avaliação sensorial do estádio de maturação dos frutos de manga. A Tb foi determinada pelo método da menor variabilidade das unidades fototérmicas (UF acumuladas do período da floração à colheita dos frutos, variabilidade avaliada pelo coeficiente de variação (cv simulado para diferentes valores da Tb. De julho a novembro de 2007, em três plantas de um pomar demonstrativo irrigado, foram identificados 82 frutos para o acompanhamento do crescimento e maturação. Entre esses frutos, em meados de dezembro de 2007, foi possível identificar 13 frutos que atingiram a maturidade fisiológica, após um período médio de observação de 112 dias. Para exigência fototérmica de 1.878.166,1 UF, encontrou-se Tb de 10 °C, valor consistente com os apresentados na literatura para a cultivar de manga, o que comprova a eficiência do método que combina a ação da temperatura e do fotoperíodo sobre a maturação dos frutos e que confere um caráter mais racional que o método tradicional da soma térmica.In this study was to determine the lower base temperature (Tb for Alfa mango fruit, using the photothermal units (PTU method in cerrado conditions. The meteorological data for the study were acquired from "Padre Ricardo Remetter" meteorological station located at Santo Antonio do Leverger, MT, Brazil (15,8° S and 56,1° W, 140 m, and the fruit data was acquired by sensorial evaluation of mango fruit maturation state. The Tb was determined by less variability of the coefficient of variation (cv method applied to the PTU sum, from flowering to harvest, simulated for

  12. The GeV Excess Shining Through: Background Systematics for the Inner Galaxy Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Calore, Francesca; Cholis, Ilias; Weniger, Christoph

    2015-02-10

    Recently, a spatially extended excess of gamma rays collected by the Fermi-LAT from the inner region of the Milky Way has been detected by different groups and with increasingly sophisticated techniques. Yet, any final conclusion about the morphology and spectral properties of such an extended diffuse emission are subject to a number of potentially critical uncertainties, related to the high density of cosmic rays, gas, magnetic fields and abundance of point sources. We will present a thorough study of the systematic uncertainties related to the modelling of diffuse background and to the propagation of cosmic rays in the inner part of our Galaxy. We will test a large set of models for the Galactic diffuse emission, generated by varying the propagation parameters within extreme conditions. By using those models in the fit of Fermi-LAT data as Galactic foreground, we will show that the gamma-ray excess survives and we will quantify the uncertainties on the excess emission morphology and energy spectrum.

  13. APOGEE Chemical Abundances of Globular Cluster Giants in the Inner Galaxy

    CERN Document Server

    Schiavon, Ricardo P; Frinchaboy, Peter M; Zasowski, Gail; Meszaros, Szabolcs; Garcia-Hernandez, D A; Cohen, Roger E; Tang, Baitian; Villanova, Sandro; Geisler, Douglas; Beers, Timothy C; Fernandez-Trincado, J G; Perez, Ana E Garcia; Lucatello, Sara; Majewski, Steven R; Martell, Sarah L; O'Connell, Robert W; Prieto, Carlos Allende; Bizyaev, Dmitry; Carrera, Ricardo; Lane, Richard R; Malanushenko, Elena; Malanushenko, Viktor; Munoz, Ricardo R; Nitschelm, Christian; Oravetz, Daniel; Pan, Kaike; Roman-Lopes, Alexandre; Schultheis, Matthias; Simmons, Audrey

    2016-01-01

    We report chemical abundances obtained by SDSS-III/APOGEE for giant stars in five globular clusters located within 2.2 kpc of the Galactic centre. We detect the presence of multiple stellar populations in four of those clusters (NGC 6553, NGC 6528, Terzan 5, and Palomar 6) and find strong evidence for their presence in NGC 6522. All clusters present a significant spread in the abundances of N, C, Na, and Al, with the usual correlations and anti-correlations between various abundances seen in other globular clusters. Our results provide important quantitative constraints on theoretical models for self-enrichment of globular clusters, by testing their predictions for the dependence of yields of elements such as Na, N, C, and Al on metallicity. They also confirm that, under the assumption that field N-rich stars originate from globular cluster destruction, they can be used as tracers of their parental systems in the high- metallicity regime.

  14. The Initial Mass Function of the Inner Galaxy Measured from OGLE-III Microlensing Timescales

    Science.gov (United States)

    Wegg, Christopher; Gerhard, Ortwin; Portail, Matthieu

    2017-07-01

    We use the timescale distribution of ˜3000 microlensing events measured by the OGLE-III survey, together with accurate new made-to-measure dynamical models of the Galactic bulge/bar region, to measure the IMF in the inner Milky Way. The timescale of each event depends on the mass of the lensing object, together with the relative distances and velocities of the lens and source. The dynamical model statistically provides these distances and velocities, allowing us to constrain the lens mass function, and thereby infer the IMF. Parameterizing the IMF as a broken power-law, we find slopes in the main-sequence {α }{ms}=1.31+/- 0.10{| }{stat}+/- 0.10{| }{sys}, and brown dwarf region {α }{bd}=-0.7+/- 0.9{| }{stat}+/- 0.8{| }{sys}, where we use a fiducial 50% binary fraction, and the systematic uncertainty covers the range of binary fractions 0%-100%. Similarly, for a log-normal IMF we conclude {M}c=(0.17+/- 0.02{| }{stat}+/- 0.01{| }{sys}) {\\text{}}{M}⊙ and {σ }m=0.49+/- 0.07{| }{stat}+/- 0.06{| }{sys}. These values are very similar to a Kroupa or Chabrier IMF, respectively, showing that the IMF in the bulge is indistinguishable from that measured locally, despite the lenses lying in the inner Milky Way where the stars are mostly ˜10 Gyr old and formed on a fast α-element enhanced timescale. This therefore constrains models of IMF variation that depend on the properties of the collapsing gas cloud.

  15. Milky Way Kinematics. II. A uniform inner Galaxy HI terminal velocity curve

    CERN Document Server

    McClure-Griffiths, N M

    2016-01-01

    Using atomic hydrogen (HI) data from the VLA Galactic Plane Survey we measure the HI terminal velocity as a function of longitude for the first quadrant of the Milky Way. We use these data, together with our previous work on the fourth Galactic quadrant, to produce a densely sampled, uniformly measured, rotation curve of the Northern and Southern Milky Way between $3~{\\rm kpc} < R < 8~{\\rm kpc}$. We determine a new joint rotation curve fit for the first and fourth quadrants, which is consistent with the fit we published in McClure-Griffiths \\& Dickey (2007) and can be used for estimating kinematic distances interior to the solar circle. Structure in the rotation curves is now exquisitely well defined, showing significant velocity structure on lengths of $\\sim 200$ pc, which is much greater than the spatial resolution of the rotation curve. Furthermore, the shape of the rotation curves for the first and fourth quadrants, even after subtraction of a circular rotation fit shows a surprising degree of c...

  16. ATLASGAL - Kinematic distances and the dense gas mass distribution of the inner Galaxy

    CERN Document Server

    Wienen, M; Menten, K M; Urquhart, J S; Csengeri, T; Walmsley, C M; Bontemps, S; Russeil, D; Bronfman, L; Koribalski, B S; Schuller, F

    2015-01-01

    The formation of high mass stars and clusters occurs in giant molecular clouds. Objects in evolved stages of massive star formation such as protostars, hot molecular cores, and ultracompact HII regions have been studied in more detail than earlier, colder objects. With this in mind, the APEX Telescope Large Area Survey of the whole inner Galactic plane at 870 micron (ATLASGAL) has been carried out to provide a global view of cold dust and star formation at submillimetre wavelengths. To derive kinematic distances to a large sample of ATLASGAL clumps we divided them into groups of sources, which are located close together, mostly within a radius of 2 pc, and have velocities in a similar range with a median velocity dispersion of ~ 1 km/s. Using NH3, N2H+ and CS velocities we calculate near and far kinematic distances to 296 groups of ATLASGAL sources in the first quadrant and 393 groups in the fourth quadrant. We analyse HI self-absorption and HI absorption to resolve the kinematic distance ambiguity. We obtain...

  17. Major structures of the inner Galaxy delineated by 6.7-GHz methanol masers

    CERN Document Server

    Green, J A; McClure-Griffiths, N M; Avison, A; Breen, S L; Burton, M G; Ellingsen, S P; Fuller, G A; Gray, M D; Pestalozzi, M; Thompson, M A; Voronkov, M A

    2011-01-01

    We explore the longitude-velocity distribution of 6.7-GHz methanol masers in the context of the inner structure of our Galaxy. We analyse the correlation in velocities within this distribution and identify density enhancements indicating large-scale regions of enhanced star formation. These are interpreted as the starting points of the spiral arms and the interaction of the Galactic bar with the 3-kpc arms. The methanol masers support the presence of a long thin bar with a 45 degree orientation. Signatures of the full 3-kpc arm structure are seen, including a prominent tangent at approximately -22 degrees Galactic longitude. We compare this distribution with existing models of the gas dynamics of our Galaxy. The 3-kpc arm structure appears likely to correspond to the radius of corotation resonance of the bar, with the bar on its inner surface and the starting points of the spiral arms on its outer surface.

  18. Tracing major structures of the inner Galaxy with 6.7-GHz methanol masers

    Directory of Open Access Journals (Sweden)

    Pestalozzi M.

    2012-02-01

    Full Text Available Through analysis of correlations within the longitude-velocity distribution of 6.7-GHz methanol masers, we identify density enhancements indicative of large-scale regions of enhanced star formation. In the context of the inner structure of our Galaxy these are interpreted as the starting points of the spiral arms and the interaction of the long Galactic bar with the 3–kpc arms. Signatures of a continuous 3–kpc arm structure are seen including a prominent tangent at –22° Galactic longitude.

  19. Management of anaemia in oncohaematological patients treated with biosimilar epoetin alfa: results of an Italian observational, retrospective study

    Science.gov (United States)

    Rosti, Giovanni; Petrini, Mario; Bosi, Alberto; Galieni, Piero; Bernardi, Daniele; Giglio, Gianfranco; Dorotea, Laura; Falini, Brunangelo; Scelzi, Elvira; Veltri, Enzo; Castelli, Roberto; Longagnani, Chiara; Raggi, Tommaso; Simonetti, Federico

    2016-01-01

    Background: Many patients with solid tumours or nonmyeloid haematopoietic tumours develop symptomatic anaemia, which has a major impact on quality of life (QoL). The efficacy of erythropoiesis-stimulating agents (ESAs) in improving QoL and reducing blood transfusions has been widely demonstrated. Binocrit® (biosimilar epoetin alfa) is an ESA indicated in the European Union for treating chemotherapy-induced anaemia. The aim of this study was to investigate the effect of Binocrit® on haemoglobin (Hb) levels in anaemic cancer patients in Italian clinical practice. Methods: The ANEMONE study was a national, longitudinal, retrospective, multicentre observational study. Patients had to be 18 years or older, with a solid tumour or non-Hodgkin’s lymphoma, Hodgkin’s disease or multiple myeloma, receiving chemotherapy, and treated with Binocrit® to manage chemotherapy-induced anaemia. The primary outcomes were the proportion of patients with a Hb increase ⩾1 g/dl during the first 4 weeks and with a Hb increase ⩾2 g/dl during the first 12 weeks. Results: A total of 245 patients were enrolled and 215 patients were evaluable for statistical analysis. In the first 4 weeks, 49.3% of patients showed an increase in Hb of ⩾1 g/dl: 45.5% in patients with solid tumours and 52.1% in patients with haematological malignancies. In the first 12 weeks, 51.6% of patients showed an increase in Hb of ⩾2 g/dl (48.4% solid tumours, 54.2% haematological diseases). Treatment with Binocrit® was well tolerated. Conclusions: These results confirm the effectiveness and safety of Binocrit® for chemotherapy-induced anaemia in routine practice in patients with solid tumours, lymphoma and myeloma. PMID:28203295

  20. Diversidad alfa y beta de los artrópodos en diferentes ambientes del Parque Nacional Los Cardones, Salta (Argentina

    Directory of Open Access Journals (Sweden)

    María Belén Cava

    2013-12-01

    Full Text Available El Parque Nacional Los Cardones ubicado en la provincia de Salta protege las ecorregiones de Puna, Monte y Pastizal Altoandino Nublado de la Yungas. Nuestro objetivo es evaluar la diversidad alfa y beta de artrópodos en las ecorregiones del Parque. Se muestrearon tres sitios en cada ecorregión utilizando Pit-fall y G-Vac. Se calcularon estimadores no paramétricos de riqueza de especies, la diversidad entre ecorregiones se comparó a través de los “perfiles de diversidad” y “números efectivos de especies”, se analizó el recambio de especies y la complementariedad entre las ecorregiones y sitios de una misma ecorregión. Se registraron 469 spp/morfoespecies, la diversidad en el Parque fue alta, siendo mayor en los Pastizal Altoandino Nublado, y la más baja en la Puna. El inventario llegó al 81% de completitud. El recambio de especies entre ecorregiones fue alto, de esa manera los diferentes ambientes del Parque contribuyen a conservar la diversidad regional de artrópodos. Las ensambles de artrópodos en sitios de una misma ecorregión mostraron mayor similitud entre sí que con sitios más distantes. Se pudo reconocer tres grupos de artrópodos (arañas, dípteros e himenópteros que son diversos y abundantes, los que podrían ser utilizados en futuros estudios como grupos focales.

  1. Therapeutic and routine prophylactic properties of rFactor VIII Fc (efraloctocog alfa, Eloctate®) in hemophilia A

    Science.gov (United States)

    Chowdary, Pratima; Fosbury, Emma; Riddell, Anne; Mathias, Mary

    2016-01-01

    rFVIIIFc (efraloctocog alfa, Eloctate®) is an extended half-life (EHL) factor VIII licensed for use in patients with hemophilia A for prophylaxis and treatment of bleeding and surgical episodes. Pharmacokinetic studies in adults have shown a mean 1.5-fold increase in half-life compared to full-length factor VIII. When compared to adults, the half-life is decreased by 8% in adolescents between 12 and 17 years, by 18% in children 6 to <12 years, and by 33% in children between the ages of 2 and <6 years. There is a considerable interindividual variation in the prolongation of the half-life particularly in children and across the age groups, the range extending from no increase to a 2.5-fold increase. In addition to age, von willebrand factor (VWF) antigen level has demonstrated a significant impact on rFVIIIFc half-life, with higher VWF levels associated with greater prolongation of half-life. The pivotal and pediatric clinical trials have demonstrated the efficacy and safety of rFVIIIFc for use in regular prophylaxis and in management of bleeds and surgery. In these studies, just under half the participants showed a zero annualized bleed rate (ABR), and the median ABR (1.6 in the pivotal study for the individualized prophylaxis arm) showed a further decrease in the extension study. On average, the patients required fewer infusions (reduced by at least a third), and the mean weekly consumption seems to be in keeping with standard recombinant factor VIII. EHL rFVIIIFc has made decreased infusion frequency a possibility. However, the interindividual variability in dose and infusion frequency highlights the need for a personalized approach based on individual patient’s half-life and/or response to treatment. PMID:27695377

  2. Co-treatment with pegylated interferon alfa-2a and entecavir for hepatitis D: a randomized trial

    Institute of Scientific and Technical Information of China (English)

    Zaigham; Abbas; Mohammad; Sadik; Memon; Muhammad; Amir; Umer; Minaam; Abbas; Lubna; Shazi

    2016-01-01

    AIM: To investigate the efficacy of pegylated interferon alfa(PEG-IFNα) therapy with and without entecavir in patients with chronic hepatitis D. METHODS: Forty hepatitis D virus(HDV) RNA positive patients were randomized to receive either PEG-IFNα-2a 180 μg weekly in combination with entecavir 0.5 mg daily(n = 21) or PEG-IFNα alone(n =19). Patients who failed to show 2 log reduction in HDV RNA level at 24 wk of treatment, or had detectable HDV RNA at 48 wk of therapy were considered as treatment failure. Treatment was continued for 72 wk in the rest of the patients. All the patients were followed for 24 wk post treatment. Intention to treat analysis was performed.RESULTS: The mean age of the patients was 26.7 ± 6.8 years, 31 were male. Two log reduction in HDV RNA levels at 24 wk of therapy was achieved in 9(43%) patients receiving combination therapy and 12(63%) patients receiving PEG-IFNα alone(P = 0.199). Decline in hepatitis B surface antigen(HBs Ag) levels was insignificant. At the end of treatment, HDV RNA was negative in 8 patients(38%) receiving combination therapy and 10 patients(53%) receiving PEG-IFNα-2a alone. Virological response persisted in 7(33%) and 8(42%) patients, respectively at the end of the 24 wk follow-up period. One responder patient in the combination arm lost HBs Ag and became hepatitis B surface antibody positive. Six out of 14 baseline hepatitis B e antigen reactive patients seroconverted and four of these seroconverted patients had persistent HDV RNA clearance.CONCLUSION: Administration of PEG-IFNα-2a with or without entecavir, resulted in persistent HDV RNA clearance in 37% of patients. The addition of entecavir did not improve the overall response.

  3. Clinical Experience of Interferon Alfa-2a Treatment for Refractory Uveitis in Behçet's Disease.

    Science.gov (United States)

    Park, Ji-Youn; Chung, Yoo-Ri; Lee, Kihwang; Song, Ji Hun; Lee, Eun-So

    2015-07-01

    Behçet's disease (BD) involves multisystem vasculitis of unknown origin. Ocular manifestations of BD mostly include bilateral panuveitis and retinal vasculitis, which are very challenging to treat. Interferon alfa-2a (IFN) has been recently introduced for treating refractory Behçet uveitis, mainly in Germany and Turkey. Nonetheless, there is so far no consensus about the ideal treatment regimen of IFN for Behçet uveitis. We report our experience of IFN treatment in five Korean BD patients with refractory uveitis. All patients complained of oral ulcers; one patient had a positive pathergy test and 2 showed the presence of HLA-B51. Immunosuppressive agents used prior to IFN treatment included cyclosporine and methotrexate. The IFN treatment was commenced with a dose of 6-9 MIU/day for 7 days, adjusted according to individual ocular manifestations, tapered down to 3 MIU three times in a week, and then discontinued. All patients showed positive response to IFN treatment; 50% of them showed complete response without additional major ocular inflammation during the follow-up period. Other BD symptoms also improved after IFN treatment in most cases. After treatment, the relapse rate and the required dose of oral corticosteroid were decreased in most cases, showing a significant steroid-sparing effect. However, the visual acuity was not improved in most cases due to irreversible macular sequelae. Despite the small sample size of this study, we suggest that, in Korean patients, IFN is an effective treatment modality for BD uveitis as was observed in German and Turkish patients.

  4. 低纬西太平洋末次冰期以来海洋孢粉记录对海平面变化的不同响应%THE DIFFERENT RESPONSE OF MARINE POLLEN RECORDS TO THE SEA LEVEL CHANGE IN THE LOW LATITUDE WEST PACIFIC SINCE THE LAST GLACIAL PERIOD

    Institute of Scientific and Technical Information of China (English)

    边叶萍; 李家彪; 翦知湣; 初凤友; 翁成郁; Kuhnt Wolfgang

    2012-01-01

    通过对菲律宾南部MD06-3075和婆罗洲东北部MD98-2178两个深海钻孔的孢粉分析,结合氧同位素记录以及西太平洋地区已有的孢粉记录,得到末次冰期研究区域海洋孢粉中的红树林花粉和蕨类孢子含量比间冰期时要低,特别是在末次冰盛期.这可能体现了冰期时海平面较低,湿度较低等环境和气候条件.同时,西太平洋一系列海洋孢粉记录的对比发现,南海南部陆坡地区冰期时的红树林含量仍然较高,巽他陆架等地区冰期时的蕨类孢子含量则表现为明显高值.这些记录的差异可能说明了由于不同地区的地形分布特征不同,在冰期海平面下降时,导致陆架出露的幅度存在明显的差异.如果陆架较宽,则海平面波动会显著改变植被分布范围和孢粉传播距离等,从而对孢粉数据的气候、环境指示意义产生影响.因此,海洋孢粉数据解释时需要结合多种沉积记录指标以及地球物理调查等,提高海平面变化以及相应的沉积环境演化对孢粉搬运沉积的了解程度,增强海洋孢粉中古气候、古环境信息的有效提取.%The climate change in the low latitude area since the last glacial is one of the most hotspot for Quaternary climate research. Meanwhile,the tropical vegetation has a good correspondence with tropical climate change,and it is one of the major factors controlling the climate modeling as well as the environment prediction. But marine pollen record, which was used to reconstruct the history of climate and environment change, reflects not only vegetation state of source area,but also the changes in pollen deposition. The sea-level change would influence the deposition pattern of the marine pollen, especially the mangrove pollen and fern spore, which will make the interpretation of the sedimentation records produce a great deviation with the actual climate and environment condition. It is thus essential to understand the relationship

  5. Peginterferon alfa-2a is associated with elevations in alanine aminotransferase at the end of treatment in chronic hepatitis C patients with sustained virologic response.

    Directory of Open Access Journals (Sweden)

    Chih-Wei Tseng

    Full Text Available The purpose of this study was to investigate the incidence and demographic/clinical factors of alanine aminotransferase (ALT abnormalities at the end of treatment (EOT in chronic hepatitis C (CHC patients with sustained virologic response (SVR.Seven hundred naïve CHC patients who underwent combination treatment between January 2003 and December 2010 were included in the study. The patients with SVR and serum ALT>upper limit of normal (ULN at the EOT were further analyzed. The effects of clinical characteristics, treatment regimen, and virologic variables were evaluated by logistic regression. Of the 700 included patients, 488 (69.7% achieved an SVR after treatment, and 235 (33.6% had serum ALT levels>ULN at the EOT. Of those 488 patients, 137 (28.1% had abnormal ALT values at the EOT. A multivariate analysis showed that the occurrence of ALT abnormalities at the EOT was significantly associated with pegylated interferon (PEG-IFN alfa-2a (odds ratio [OR], 2.24; 95% confidence interval [CI], 1.45-3.45; P<0.001, baseline fatty liver (OR, 1.76; 95% CI, 1.16-2.76; P = 0.007, and baseline liver cirrhosis (OR, 2.35; 95% CI, 1.35-4.09; P = 0.002.Use of PEG-IFN-alfa-2a, fatty liver, and cirrhosis are important factors associated with EOT-ALT abnormality in CHC patients receiving combination therapy that achieve an SVR. PEG-IFN-alfa-2a-related EOT-ALT elevation will become normal at the end of follow-up, but fatty liver and cirrhosis-related ALT elevation will not be resolved.

  6. Safety and physiological effects of two different doses of elosulfase alfa in patients with morquio a syndrome: A randomized, double-blind, pilot study.

    Science.gov (United States)

    Burton, Barbara K; Berger, Kenneth I; Lewis, Gregory D; Tarnopolsky, Mark; Treadwell, Marsha; Mitchell, John J; Muschol, Nicole; Jones, Simon A; Sutton, V Reid; Pastores, Gregory M; Lau, Heather; Sparkes, Rebecca; Genter, Fred; Shaywitz, Adam J; Harmatz, Paul

    2015-10-01

    The primary treatment outcomes of a phase 2, randomized, double-blind, pilot study evaluating safety, physiological, and pharmacological effects of elosulfase alfa in patients with Morquio A syndrome are herewith presented. Patients aged ≥7 years and able to walk ≥200 m in the 6-min walk test (6MWT) were randomized to elosulfase alfa 2.0 or 4.0 mg/kg/week for 27 weeks. The primary objective was to evaluate the safety of both doses. Secondary objectives were to evaluate effects on endurance (6MWT and 3-min stair climb test [3MSCT]), exercise capacity (cardio-pulmonary exercise test [CPET]), respiratory function, muscle strength, cardiac function, pain, and urine keratan sulfate (uKS) levels, and to determine pharmacokinetic parameters. Twenty-five patients were enrolled (15 randomized to 2.0 mg/kg/week and 10 to 4.0 mg/kg/week). No new or unexpected safety signals were observed. After 24 weeks, there were no improvements versus baseline in the 6MWT, yet numerical improvements were seen in the 3MSCT with 4.0 mg/kg/week. uKS and pharmacokinetic data suggested no linear relationship over the 2.0-4.0 mg/kg dose range. Overall, an abnormal exercise capacity (evaluated in 10 and 5 patients in the 2.0 and 4.0 mg/kg/week groups, respectively), impaired muscle strength, and considerable pain were observed at baseline, and there were trends towards improvements in all domains after treatment. In conclusion, preliminary data of this small study in a Morquio A population with relatively good endurance confirmed the acceptable safety profile of elosulfase alfa and showed a trend of increased exercise capacity and muscle strength and decreased pain.

  7. An Alpha spectrometer for measuring radon daughter individual activity concentration; Spettrometro Alfa per la misura delle concentrazioni individuali in attivita' della progenie del radon

    Energy Technology Data Exchange (ETDEWEB)

    Berico, M.; Formignani, M. [ENEA, Div. Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche E. Clementel, Bologna (Italy); Mariotti, F. [Bologna Univ., Bologna (Italy). Dipt. di Fisica

    2001-07-01

    In the frame of the program of the Institute for Radiation Protection of ENEA, related to the evaluation of dose from radon and thoron progeny, an alpha spectrometer for the continuous air monitoring (CAM type) of radon and thoron has been realized. The constructive characteristics of the device are here presented together with energy and efficiency calibration. The device allows, by means of a screen type diffusion battery and a filter, to determinate the single radioactivity of each radionuclide of the progeny selecting them in relation to their diffusive behaviour (dichotomous particle size selection). The three-count filter method has been employed to measure the concentrations of {sup 218}Po, {sup 214}Pb and {sup 214}Bi in air. Radon and thoron effective doses using a dosimetric, instead of an epidemiologic approach, will be then evaluated. [Italian] Presso l'Istituto per la Radioprotezione, nell'ambito del programma di valutazione di dose da radon e' stato progettato e realizzato uno spettrometro alfa per il monitoraggio continuo in aria (CAM) della progenie del radon e del toron. Le caratteristiche costruttive dello strumento permettono, tramite l'utilizzo di batterie a diffusione a reti, di determinare l'attivita' individuale della progenie per diverse dimensioni granulometriche in particolare per la frazione attaccata e non al particolato amosferico con un taglio granulometrico di qualche nanometro. E' stato inoltre applicato un metodo spettrometrico a tre conteggi per il calcolo delle concentrazioni individuali della progenie del radon, {sup 218}Po, {sup 214}Pb and {sup 214}Bi, effettuando un conteggio alfa di {sup 218}Po e due conteggi alfa di {sup 214}Po. Tale informazione consentira' una valutazione della dose di radon utilizzando il modello dosimetrico in alternativa a quello epidemiologico.

  8. Conocimiento del déficit Alfa1-antitripsina y de la discinesia ciliar primaria por estudiantes de medicina y profesionales sanitarios

    OpenAIRE

    Requena Fernández, MªÁngeles

    2015-01-01

    El déficit de alfa-1-antitripsina (DAAT) y la discinesia ciliar primaria (DCP), se engloban dentro de las enfermedades raras, siendo sin embargo trastornos genéticos y hereditarios con una prevalencia nada desdeñable. En ellas, el infradiagnóstico y el retraso diagnóstico son una constante y característica común. Dado que una de las posibles causas de este problema puede ser el bajo grado de conocimiento de ambas enfermedades por parte de los profesionales que atienden a este tipo de pac...

  9. Long-term outcome of hepatitis B e antigen-positive patients with compensated cirrhosis treated with interferon alfa. European Concerted Action on Viral Hepatitis (EUROHEP)

    DEFF Research Database (Denmark)

    Fattovich, G; Giustina, G; Realdi, G;

    1997-01-01

    The aim of this study was to evaluate whether interferon alfa (IFN-alpha) treatment-associated virological and biochemical remission improves survival in a cohort of 90 white patients with compensated cirrhosis caused by hepatitis B (Child A) followed for a mean period of 7 years. Inclusion...... criteria were biopsy-proven cirrhosis, hepatitis B e antigen (HBeAg) positivity, abnormal serum aminotransferase levels, exclusion of hepatitis delta virus, and absence of complications of cirrhosis. Of the 40 IFN-treated patients, 27 (67%) showed sustained HBeAg loss with alanine aminotransferase (ALT...

  10. Conocimiento del déficit Alfa1-antitripsina y de la discinesia ciliar primaria por estudiantes de medicina y profesionales sanitarios

    OpenAIRE

    Requena Fernández, MªÁngeles

    2015-01-01

    El déficit de alfa-1-antitripsina (DAAT) y la discinesia ciliar primaria (DCP), se engloban dentro de las enfermedades raras, siendo sin embargo trastornos genéticos y hereditarios con una prevalencia nada desdeñable. En ellas, el infradiagnóstico y el retraso diagnóstico son una constante y característica común. Dado que una de las posibles causas de este problema puede ser el bajo grado de conocimiento de ambas enfermedades por parte de los profesionales que atienden a este tipo de pac...

  11. Estudio de la utilidad clínica del perfil de estrés oxidativo en pacientes con déficit de alfa-1 antitripsina

    OpenAIRE

    Castillo Corullón, Silvia

    2016-01-01

    Introducción: Investigaciones recientes en modelos animales sugieren la participación del estrés oxidativo y el daño de oxidativo en la patogénesis del déficit de alfa 1 antitripsina (DAAT). Sin embargo, no hay datos disponibles sobre el estado de estrés oxidativo y la actividad de los enzimas antioxidantes en estos pacientes. Se sabe que el estrés oxidativo está implicado en la patogénesis de enfermedades en otros organismos (aterosclesosis, enfermedades neurodegenerativas, diabetes mel...

  12. Terapia combinada de criocirugía e interferón alfa-2b humano recombinante en el condiloma acuminado

    OpenAIRE

    Alfonso Trujillo , Israel

    2015-01-01

    Las continuas recidivas de lcondiloma acuminado hace necesario la búsqueda constante de alternativas terapéuticas. Para evaluar la eficacia terapéutica y seguridad del interferón alfa-2b asociado a criocirugía en el condiloma acuminado fue realizado un ensayo cl