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Sample records for lambda orionis cluster

  1. The Lambda Orionis association. [star cluster anomalies

    NASA Technical Reports Server (NTRS)

    Murdin, P.; Penston, M. V.

    1977-01-01

    The Lambda Orionis association has the photometric properties of a typical young cluster with an age of about 4 million yr. Its distance is 400 + or - 40 pc. Attention is drawn to the lack of a dense molecular cloud and associated infrared sources in this young grouping

  2. SPITZER OBSERVATIONS OF THE {lambda} ORIONIS CLUSTER. II. DISKS AROUND SOLAR-TYPE AND LOW-MASS STARS

    SciTech Connect

    Hernandez, Jesus; Morales-Calderon, Maria; Calvet, Nuria; Hartmann, L.; Muzerolle, J.; Gutermuth, R.; Luhman, K. L.; Stauffer, J. E-mail: muzerol@stsci.ed

    2010-10-20

    We present IRAC/MIPS Spitzer Space Telescope observations of the solar-type and the low-mass stellar population of the young ({approx}5 Myr) {lambda} Orionis cluster. Combining optical and Two Micron All Sky Survey photometry, we identify 436 stars as probable members of the cluster. Given the distance (450 pc) and the age of the cluster, our sample ranges in mass from 2 M{sub sun} to objects below the substellar limit. With the addition of the Spitzer mid-infrared data, we have identified 49 stars bearing disks in the stellar cluster. Using spectral energy distribution slopes, we place objects in several classes: non-excess stars (diskless), stars with optically thick disks, stars with 'evolved disks' (with smaller excesses than optically thick disk systems), and 'transitional disk' candidates (in which the inner disk is partially or fully cleared). The disk fraction depends on the stellar mass, ranging from {approx}6% for K-type stars (R{sub C} - J < 2) to {approx}27% for stars with spectral-type M5 or later (R{sub C} - J>4). We confirm the dependence of disk fraction on stellar mass in this age range found in other studies. Regarding clustering levels, the overall fraction of disks in the {lambda} Orionis cluster is similar to those reported in other stellar groups with ages normally quoted as {approx}5 Myr.

  3. SPITZER OBSERVATIONS OF THE lambda ORIONIS CLUSTER. I. THE FREQUENCY OF YOUNG DEBRIS DISKS AT 5 Myr

    SciTech Connect

    Hernandez, Jesus; Calvet, Nuria; Hartmann, L.; Muzerolle, J.; Gutermuth, R.; Stauffer, J.

    2009-12-10

    We present IRAC/MIPS Spitzer observations of intermediate-mass stars in the 5 Myr old lambda Orionis cluster. In a representative sample of stars earlier than F5 (29 stars), we find a population of nine stars with varying degree of moderate 24 mum excess comparable to those produced by debris disks in older stellar groups. As expected in debris disks systems, those stars do not exhibit emission lines in their optical spectra. We also include in our study the star HD 245185, a known Herbig Ae object which displays excesses in all Spitzer bands and shows emission lines in its spectrum. We compare the disk population in the lambda Orionis cluster with the disk census in other stellar groups studied using similar methods to detect and characterize their disks and spanning a range of ages from 3 Myr to 10 Myr. We find that for stellar groups of 5 Myr or older the observed disk frequency in intermediate-mass stars (with spectral types from late B to early F) is higher than in low-mass stars (with spectral types K and M). This is in contradiction with the observed trend for primordial disk evolution, in which stars with higher stellar masses dissipate their primordial disks faster. At 3 Myr, the observed disk frequency in intermediate-mass stars is still lower than for low-mass stars indicating that second generation dusty disks start to dominate the disk population at 5 Myr for intermediate-mass stars. This result agrees with recent models of evolution of solids in the region of the disk where icy objects form (>30 AU), which suggest that at 5-10 Myr collisions start to produce large amount of dust during the transition from runaway to oligarchic growth (reaching sizes of approx500 km) and then dust production peaks at 10-30 Myr, when objects reach their maximum size (>=1000 km).

  4. First results from XILO: XMM-Newton Investigations in the Lambda Orionis star forming region

    NASA Astrophysics Data System (ADS)

    Stelzer, B.; Barrado y Navascues, D.; Huelamo, N.; Morales-Calderon, M.; Bayo, A.

    2010-11-01

    The λ Orionis star formation region (1-6 Myr, 400 pc) is a complex of star-forming clouds surrounded by a molecular ring with ~ 5° radius which was probably formed by a supernova explosion (Dolan & Mathieu 2002). For a complete picture of star formation, believed to be determined by the supernova blast, the large-scale distribution of the pre-main sequence population in λ Ori needs to be examined. We have embarked on a multi-wavelength study (XMM-Newton/X-ray, CFHT/optical, Spitzer/IR) of selected areas within this intriguing star-forming complex that enables us to identify young stars and brown dwarfs. Our study comprises various areas within the cloud complex as shown in Fig.1. This data set is among the most extended X-ray surveys carried out with XMM-Newton in a coherent star-forming environment. The XMM-Newton observations combined with optical and IR data reveal the low-mass stellar population down to ~ 0.4 M⊙. For this mass-limited sample, our preliminary analysis confirms the anomalously low disk-fraction of the central star cluster Coll 69, the Eastern extension of its low-mass population pointing towards B 35, and the concentration of young stars in front of B 35. The analysis of the ‘on-cloud field' of B 35 (white in the figure) will show if the cloud is currently forming stars. This will be crucial for determining the star-forming history in the whole λ Ori region.

  5. IS THE DUST CLOUD AROUND LAMBDA ORIONIS A RING OR A SHELL, OR BOTH?

    SciTech Connect

    Lee, Dukhang; Seon, Kwang-Il; Jo, Young-Soo

    2015-06-20

    The dust cloud around λ Orionis is observed to be circularly symmetric with a large angular extent (≈8°). However, whether the three-dimensional (3D) structure of the cloud is shell- or ring-like has not yet been fully resolved. We study the 3D structure using a new approach that combines a 3D Monte Carlo radiative transfer model for ultraviolet (UV) scattered light and an inverse Abel transform, which gives a detailed 3D radial density profile from a two-dimensional column density map of a spherically symmetric cloud. By comparing the radiative transfer models for a spherical shell cloud and that for a ring cloud, we find that only the shell model can reproduce the radial profile of the scattered UV light, observed using the S2/68 UV observation, suggesting a dust shell structure. However, the inverse Abel transform applied to the column density data from the Pan-STARRS1 dust reddening map results in negative values at a certain radius range of the density profile, indicating the existence of additional, non-spherical clouds near the nebular boundary. The additional cloud component is assumed to be of toroidal ring shape; we subtracted from the column density to obtain a positive, radial density profile using the inverse Abel transform. The resulting density structure, composed of a toroidal ring and a spherical shell, is also found to give a good fit to the UV scattered light profile. We therefore conclude that the cloud around λ Ori is composed of both ring and shell structures.

  6. A spectroscopic census in young stellar regions: the σ Orionis cluster

    SciTech Connect

    Hernández, Jesús; Perez, Alice; Hernan, Ramírez; Calvet, Nuria; Hartmann, Lee; Briceño, Cesar; Olguin, Lorenzo; Contreras, Maria E.; Allen, Lori; Espaillat, Catherine

    2014-10-10

    We present a spectroscopic survey of the stellar population of the σ Orionis cluster. We have obtained spectral types for 340 stars. Spectroscopic data for spectral typing come from several spectrographs with similar spectroscopic coverage and resolution. More than half of the stars in our sample are members confirmed by the presence of lithium in absorption, strong Hα in emission or weak gravity-sensitive features. In addition, we have obtained high-resolution (R ∼ 34,000) spectra in the Hα region for 169 stars in the region. Radial velocities were calculated from this data set. The radial velocity distribution for members of the cluster is in agreement with previous work. Analysis of the profile of the Hα line and infrared observations reveals two binary systems or fast rotators that mimic the Hα width expected in stars with accretion disks. On the other hand, there are stars with optically thick disks and narrow Hα profiles not expected in stars with accretion disks. This contribution constitutes the largest homogeneous spectroscopic data set of the σ Orionis cluster to date.

  7. A SCUBA-2 850-micron Survey of Circumstellar Disks in the λ Orionis Cluster

    NASA Astrophysics Data System (ADS)

    Ansdell, Megan; Williams, Jonathan P.; Cieza, Lucas A.

    2015-06-01

    We present results from an 850 μm survey of the ˜5 Myr old λ Orionis star-forming region. We used the SCUBA-2 camera on the James Clerk Maxwell Telescope to survey a ˜0.°5-diameter circular region containing 36 (out of 59) cluster members with infrared excesses indicative of circumstellar disks. We detected only one object at \\gt 3σ significance, the Herbig Ae star HD 245185, with a flux density of ˜74 mJy beam-1 corresponding to a dust mass of ˜150 {M}\\oplus . Stacking the individually undetected sources did not produce a significant mean signal but gives an upper limit on the average dust mass for λ Orionis disks of ˜3 {M}\\oplus . Our follow-up observations of HD 245185 with the Submillimeter Array found weak CO 2-1 line emission with an integrated flux of ˜170 mJy km s-1 but no 13CO or C18O isotopologue emission at 30 mJy km s-1 sensitivity, suggesting a gas mass of ≲ 1 M{}{Jup}. The implied gas-to-dust ratio is thus ≳ 50 times lower than the canonical interstellar medium value, setting HD 245185 apart from other Herbig Ae disks of similar age, which have been found to be gas rich; as HD 245185 also shows signs of accretion, we may be catching it in the final phases of disk clearing. Our study of the λ Orionis cluster places quantitative constraints on planet formation timescales, indicating that at ˜5 Myr the average disk no longer has sufficient dust and gas to form giant planets and perhaps even super-Earths; the bulk material has been mostly dispersed or is locked in pebbles/planetesimals larger than a few mm in size.

  8. Search and characterization of T-type planetary mass candidates in the σ Orionis cluster

    NASA Astrophysics Data System (ADS)

    Peña Ramírez, K.; Zapatero Osorio, M. R.; Béjar, V. J. S.; Rebolo, R.; Bihain, G.

    2011-08-01

    Context. The proper characterization of the least massive population of the young σ Orionis star cluster is required to understand the form of the cluster mass function and its impact on our comprehension of the substellar formation processes. S Ori 70 (T5.5 ± 1) and 73, two T-type cluster member candidates, are likely to have masses between 3 and 7 MJup if their age is 3 Myr. It awaits confirmation whether S Ori 73 has a methane atmosphere. Aims: We aim to: i) confirm the presence of methane absorption in S Ori 73 by performing methane imaging; ii) study S Ori 70 and 73 cluster membership via photometric colors and accurate proper motion analysis; and iii) perform a new search to identify additional T-type σ Orionis member candidates. Methods: We obtained HAWK-I (VLT) J, H, and CH4off photometry of an area of 119.15 arcmin2 in σ Orionis down to Jcomp = 21.7 and Hcomp = 21 mag. S Ori 70 and 73 are contained in the explored area. Near-infrared data were complemented with optical photometry using images acquired with OSIRIS (GTC) and VISTA as part of the VISTA Orion survey. Color-magnitude and color-color diagrams were constructed to characterize S Ori 70 and 73 photometrically, and to identify new objects with methane absorption and masses below 7 MJup. We derived proper motions by comparing of the new HAWK-I and VISTA images with published near-infrared data taken 3.4 - 7.9 yr ago. Results.S Ori 73 has a red H - CH4off color indicating methane absorption in the H-band and a spectral type of T4 ± 1. S Ori 70 displays a redder methane color than S Ori 73 in agreement with its latter spectral classification. Our proper motion measurements (μα cos δ = 26.7 ± 6.1, μδ = 21.3 ± 6.1 mas yr-1 for S Ori 70, and μα cos δ = 46.7 ± 4.9, μδ = -6.3 ± 4.7 mas yr-1 for S Ori 73) are larger than the motion of σ Orionis, rendering S Ori 70 and 73 cluster membership uncertain. From our survey, we identified one new photometric candidate with J = 21.69 ± 0.12 mag

  9. Discovery of young, isolated planetary mass objects in the final sigma Orionis star cluster.

    PubMed

    Zapatero Osorio, M R; Béjar, V J; Martín, E L; Rebolo, R; Barrado y Navascués, D; Bailer-Jones, C A; Mundt, R

    2000-10-06

    We present the discovery by optical and near-infrared imaging of an extremely red, low-luminosity population of isolated objects in the young, nearby stellar cluster around the multiple, massive star final sigma Orionis. The proximity (352 parsecs), youth (1 million to 5 million years), and low internal extinction make this cluster an ideal site to explore the substellar domain from the hydrogen mass limit down to a few Jupiter masses. Optical and near-infrared low-resolution spectroscopy of three of these objects confirms the very cool spectral energy distribution (atmospheric effective temperatures of 1700 to 2200 kelvin) expected for cluster members with masses in the range 5 to 15 times that of Jupiter. Like the planets of the solar system, these objects are unable to sustain stable nuclear burning in their interiors, but in contrast they are not bound to stars. This new kind of isolated giant planet, which apparently forms on time scales of less than a few million years, offers a challenge to our understanding of the formation processes of planetary mass objects.

  10. Are isolated planetary-mass objects really isolated?. A brown dwarf-exoplanet system candidate in the σ Orionis cluster

    NASA Astrophysics Data System (ADS)

    Caballero, J. A.; Martín, E. L.; Dobbie, P. D.; Barrado Y Navascués, D.

    2006-12-01

    Context: .Free-floating planetary-mass objects have masses below the deuterium burning mass limit at about 13 Jupiter masses, and have mostly been found in very young open clusters. Their origin and relationship to stars and brown dwarfs are still a mystery. Aims: .The recent detection by direct imaging of three giant planets at wide separation (50-250 AU) from their primaries has raised the question about the true "isolation" of planetary-mass objects in clusters. Our goal was to test the possibility that some free-floating planetary-mass objects could in fact be part of wide planetary systems. Methods: .We searched in the literature for stellar and brown-dwarf candidates members of the σ Orionis cluster (~3 Ma, ~360 pc) at small angular separations from published candidate planetary-mass objects. We found one candidate planetary system composed of an X-ray source, SE 70, and a planetary-mass object, S Ori 68, separated by only 4.6 arcsec. In order to assess the cluster membership of the X-ray source, we obtained mid-resolution optical spectroscopy using ISIS on the William Herschel Telescope. We also compiled additional data on the target from available astronomical catalogues. Results: .We have found that SE 70 follows the spectrophotometric sequence of the cluster and displays spectroscopic features of youth, such as lithium in absorption and chromospheric Hα emission. The radial velocity is consistent with cluster membership. Hence, SE 70 is very probably a member of the σ Orionis cluster. The projected physical separation between SE 70 and S Ori 68 is 1700~± 300 AU at the distance of the cluster. If a common proper motion is confirmed in the near future, the system would be composed of an M5-6 brown dwarf with an estimated mass of ~45 M_Jup and an L5 ± 2 giant planet with an estimated mass of ~5 M_Jup. It would be the widest and one of the lowest-mass planetary systems known so far.

  11. Comparison of Cluster Lensing Profiles with Lambda CDM Predictions

    SciTech Connect

    Broadhurst, Tom; Umetsu, Keiichi; Medezinski, Elinor; Oguri, Masamune; Rephaeli, Yoel; /Tel Aviv U. /San Diego, CASS

    2008-05-21

    We derive lens distortion and magnification profiles of four well known clusters observed with Subaru. Each cluster is very well fitted by the general form predicted for Cold Dark Matter (CDM) dominated halos, with good consistency found between the independent distortion and magnification measurements. The inferred level of mass concentration is surprisingly high, 8 < c{sub vir} < 15 ( = 10.39 {+-} 0.91), compared to the relatively shallow profiles predicted by the {Lambda}CDM model, c{sub vir} = 5.06 {+-} 1.10 (for = 1.25 x 10{sup 15} M{sub {circle_dot}}/h). This represents a 4{sigma} discrepancy, and includes the relatively modest effects of projection bias and profile evolution derived from N-body simulations, which oppose each other with little residual effect. In the context of CDM based cosmologies, this discrepancy implies some modification of the widely assumed spectrum of initial density perturbations, so clusters collapse earlier (z {ge} 1) than predicted (z < 0.5) when the Universe was correspondingly denser.

  12. SHAPES OF GAS, GRAVITATIONAL POTENTIAL, AND DARK MATTER IN {Lambda}CDM CLUSTERS

    SciTech Connect

    Lau, Erwin T.; Kravtsov, Andrey V.; Nagai, Daisuke; Zentner, Andrew R.

    2011-06-20

    We present analysis of the three-dimensional shape of intracluster gas in clusters formed in cosmological simulations of the {Lambda}CDM cosmology and compare it to the shape of dark matter distribution and the shape of the overall isopotential surfaces. We find that in simulations with radiative cooling, star formation, and stellar feedback (CSF), intracluster gas outside the cluster core (r {approx}> 0.1r{sub 500}) is more spherical compared to non-radiative (NR) simulations, while in the core the gas in the CSF runs is more triaxial and has a distinctly oblate shape. The latter reflects the ongoing cooling of gas, which settles into a thick oblate ellipsoid as it loses thermal energy. The shape of the gas in the inner regions of clusters can therefore be a useful diagnostic of gas cooling. We find that gas traces the shape of the underlying potential rather well outside the core, as expected in hydrostatic equilibrium. At smaller radii, however, the gas and potential shapes differ significantly. In the CSF runs, the difference reflects the fact that gas is partly rotationally supported. Interestingly, we find that in NR simulations the difference between gas and potential shape at small radii is due to random gas motions, which make the gas distribution more spherical than the equipotential surfaces. Finally, we use mock Chandra X-ray maps to show that the differences in shapes observed in a three-dimensional distribution of gas are discernible in the ellipticity of X-ray isophotes. Contrasting the ellipticities measured in simulated clusters against observations can therefore constrain the amount of cooling in the intracluster medium and the presence of random gas motions in cluster cores.

  13. Young stars and brown dwarfs surrounding Alnilam (ɛ Orionis) and Mintaka (δ Orionis)

    NASA Astrophysics Data System (ADS)

    Caballero, J. A.; Solano, E.

    2008-07-01

    Aims: We look for new regions to search for substellar objects. Methods: Two circular areas, 45 arcmin-radius each, centred on the young massive star systems Alnilam and Mintaka in the Orion Belt, were explored. The regions are very young (less than 10 Ma), have low extinction, and are neighbours to σ Orionis (~3 Ma), a young open cluster very rich in brown dwarfs and planetary-mass objects. We used Virtual Observatory tools, the astro-photometric Tycho-2, DENIS and 2MASS catalogues, 10 control fields at similar galactic latitudes, as well as X-ray, mid-infrared, and spectroscopic data from the literature. Results: We compiled exhaustive lists of known young stars and new candidate members in the Ori OB1b association and of fore- and background sources. A total of 136 stars display features of extreme youth, like early spectral types, lithium in absorption, or mid-infrared flux excess. Other two young brown dwarf and 289 star candidates have been identified from an optical/near-infrared colour-magnitude diagram. We list another 74 known objects that might belong to the association. This catalogue can serve as input for characterising the stellar and high-mass substellar populations in the Orion Belt. Finally, we investigated the surface densities and radial distributions of young objects surrounding Alnilam and Mintaka and compared them with those in the σ Orionis cluster. We report on a new open cluster centred on Mintaka. Conclusions: Both regions can be analogues to the σ Orionis cluster, but more massive, more extended, slightly older, and less radially concentrated. Tables A.1 to A.18 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/485/931

  14. Lithium and Hα in stars and brown dwarfs of sigma Orionis.

    NASA Astrophysics Data System (ADS)

    Zapatero Osorio, M. R.; Béjar, V. J. S.; Pavlenko, Ya.; Rebolo, R.; Allende Prieto, C.; Martín, E. L.; García López, R. J.

    2002-03-01

    We present intermediate- and low-resolution optical spectra around Hα and Li I lambda 6708 Åfor a sample of 25 low mass stars and 2 brown dwarfs with confirmed membership in the pre-main sequence stellar sigma Orionis cluster. Our observations are intended to investigate the age of the cluster. The spectral types derived for our target sample are found to be in the range K6-M8.5, which corresponds to a mass interval of roughly 1.2-0.02 Msun on the basis of state-of-the-art evolutionary models. Radial velocities (except for one object) are found to be consistent with membership in the Orion complex. All cluster members show considerable Hα emission and the Li I resonance doublet in absorption, which is typical of very young ages. We find that our pseudo-equivalent widths of Hα and Li I (measured relative to the observed local pseudo-continuum formed by molecular absorptions) appear rather dispersed (and intense in the case of Hα ) for objects cooler than M3.5 spectral class, occurring at the approximate mass where low mass stars are expected to become fully convective. The least massive brown dwarf in our sample, S Ori 45 (M8.5, ~ 0.02 Msun), displays variable Hα emission and a radial velocity that differs from the cluster mean velocity. Tentative detection of forbidden lines in emission indicates that this brown dwarf may be accreting mass from a surrounding disk. We also present recent computations of Li I lambda 6708 Åcurves of growth for low gravities and for the temperature interval (about 4000-2600 K) of our sample. The comparison of our observations to these computations allows us to infer that no lithium depletion has yet taken place in sigma Orionis, and that the observed pseudo-equivalent widths are consistent with a cluster initial lithium abundance close to the cosmic value. Hence, the upper limit to the sigma Orionis cluster age can be set at 8 Myr, with a most likely value around 2-4 Myr. Based on observations made with the following telescopes

  15. Protoplanetary Formation and the FU Orionis Outburst

    NASA Technical Reports Server (NTRS)

    Bodenheimer, P. H.

    1996-01-01

    The following three publications which reference the above grant from the NASA Origins of Solar Systems program are attached and form the final technical report for this project. The research involved comparisons of the spectral energy distributions of FU Orionis objects with theoretical models and associated studies of the structure of the outbursting accretion disks, as well as related studies on the effects of magnetic fields in disks, which will lead in the future to models of FU Orionis outbursts which include the effects of magnetic fields. The project was renewed under a new grant NAGW-4456, entitled 'Effects of FU Orionis Outbursts on Protoplanetary Disks'. Work now being prepared for publication deals more specifically with the issue of the effects of the outbursts on protoplanetary formation. Models of the spectral energy distribution of FU Orionis stars. A simple model of a buoyant magnetic dynamo in accretion disks and a numerical study of magnetic buoyancy in an accretion disk have been submitted.

  16. Galaxy pairs and clusters in a lambda CDM universe: Bridging observation and simulation

    NASA Astrophysics Data System (ADS)

    Berrier, Joel Craig

    2008-06-01

    I use computer simulations to examine the evolution of close galaxy pair counts and the formation of galaxy clusters. I show that the evolution of the close pair fraction is much weaker than the strong evolution in the dark matter halo merger rate. I continue with a discussion of how galaxy cluster-sized dark matter halos are assembled. This result, contrary to some expectations, shows that galaxy clusters in simulations are built from field halos instead of groups. I conclude by presenting preliminary results of a method to determine the pair fraction of galaxies at z=3 and apply it to a spectroscopic sample of LBGs. I show that the pair fraction is a factor of ~ 4 higher at z ~ 3 compared to local galaxy samples with similar number densities.

  17. Triple immunoglobulin gene knockout transchromosomic cattle: bovine lambda cluster deletion and its effect on fully human polyclonal antibody production.

    PubMed

    Matsushita, Hiroaki; Sano, Akiko; Wu, Hua; Jiao, Jin-An; Kasinathan, Poothappillai; Sullivan, Eddie J; Wang, Zhongde; Kuroiwa, Yoshimi

    2014-01-01

    Towards the goal of producing fully human polyclonal antibodies (hpAbs or hIgGs) in transchromosomic (Tc) cattle, we previously reported that Tc cattle carrying a human artificial chromosome (HAC) comprising the entire unrearranged human immunoglobulin (Ig) heavy-chain (hIGH), kappa-chain (hIGK), and lambda-chain (hIGL) germline loci produced physiological levels of hIgGs when both of the bovine immunoglobulin mu heavy-chains, bIGHM and bIGHML1, were homozygously inactivated (bIGHM-/-, bIGHML1-/-; double knockouts or DKO). However, because endogenous bovine immunoglobulin light chain loci are still intact, the light chains are produced both from the hIGK and hIGL genomic loci on the HAC and from the endogenous bovine kappa-chain (bIGK) and lambda-chain (bIGL) genomic loci, resulting in the production of fully hIgGs (both Ig heavy-chains and light-chains are of human origin: hIgG/hIgκ or hIgG/hIgλ) and chimeric hIgGs (Ig heavy-chains are of human origin while the Ig light-chains are of bovine origin: hIgG/bIgκ or hIgG/bIgλ). To improve fully hIgG production in Tc cattle, we here report the deletion of the entire bIGL joining (J) and constant (C) gene cluster (bIGLJ1-IGLC1 to bIGLJ5-IGLC5) by employing Cre/loxP mediated site-specific chromosome recombination and the production of triple knockout (bIGHM-/-, bIGHML1-/- and bIGL-/-; TKO) Tc cattle. We further demonstrate that bIGL cluster deletion greatly improves fully hIgGs production in the sera of TKO Tc cattle, with 51.3% fully hIgGs (hIgG/hIgκ plus hIgG/hIgλ).

  18. Accretion disc flows around FU Orionis stars

    NASA Technical Reports Server (NTRS)

    Clarke, C. J.; Lin, D. N. C.; Papaloizou, J. C. B.

    1989-01-01

    The accretion disk model of FU Orionis systems in outburst is investigated by examining the time-dependent behavior of a disk around a low-mass protostar that accretes at 0.00001-0.0001 solar masses/yr. It is found that the disk may be stabilized against the thermal ionization instability by the effect of advective heat transport and that it may therefore exist in the quasi-steady-state observed in post-outburst FU Orionis systems. The disk models are used to discuss the cosmochemical consequences of possible FU Ori events during the evolution of the primordial solar nebula.

  19. X-ray clusters in a cold dark matter + lambda universe: A direct, large-scale, high-resolution, hydrodynamic simulation

    NASA Technical Reports Server (NTRS)

    Cen, Renyue; Ostriker, Jeremiah P.

    1994-01-01

    A new, three-dimensional, shock-capturing, hydrodynamic code is utilized to determine the distribution of hot gas in a cold dark matter (CDM) + lambda model universe. Periodic boundary conditions are assumed: a box with size 85/h Mpc, having cell size 0.31/h Mpc, is followed in a simulation with 270(exp 3) = 10(exp 7.3) cells. We adopt omega = 0.45, lambda = 0.55, h identically equal to H/100 km/s/Mpc = 0.6, and then, from the cosmic background explorer (COBE) and light element nucleosynthesis, sigma(sub 8) = 0.77, omega(sub b) = 0.043. We identify the X-ray emitting clusters in the simulation box, compute the luminosity function at several wavelength bands, the temperature function and estimated sizes, as well as the evolution of these quantities with redshift. This open model succeeds in matching local observations of clusters in contrast to the standard omega = 1, CDM model, which fails. It predicts an order of magnitude decline in the number density of bright (h nu = 2-10 keV) clusters from z = 0 to z = 2 in contrast to a slight increase in the number density for standard omega = 1, CDM model. This COBE-normalized CDM + lambda model produces approximately the same number of X-ray clusters having L(sub x) greater than 10(exp 43) erg/s as observed. The background radiation field at 1 keV due to clusters is approximately the observed background which, after correction for numerical effects, again indicates that the model is consistent with observations.

  20. Circumstellar Disks in FU Orionis Stars

    NASA Astrophysics Data System (ADS)

    Rodón, J. A.; Gómez, M.

    As an advance of the Master Thesis Project of Mr. Javier A. Rodón we show the observed SEDs of the FU Orionis objects V1057 Cyg, V1647 Ori and V346 Nor, and we present models of them, made whit the Monte Carlo code developed by Dr. Barbara Whitney. With these models we have determined the physical and geometrical parameters of the disks, confronting them with the canonical parameters asigned to the T Tauri objects. FULL TEXT IN SPANISH

  1. FU Orionis Outbursts and the Solar Nebula

    NASA Technical Reports Server (NTRS)

    Bell, Robbins; Young, Rich (Technical Monitor)

    1998-01-01

    Protostellar systems are variable on many timescales. The FU Orionis outburst is one of the most drastic forms of variability known to occur in low mass stellar systems. During a typical outburst lasting several decades, system luminosities may be a hundred times what is normal of the quiescent state. FU Orionis outburst events are believed to have significant impacts on the thermal structure of the protosolar nebula. Their existence has been utilized to explain features in the meteoritic record from thermally induced homogenization to chondrule formation. Recent numerical models have shown the viability of the hypothesis that the radiation observed during outburst is emitted by a luminous circumstellar disk transporting mass at a thousand times the quiescent rate. We will begin by describing what is known about the FU Orionis outburst phenomenon from recent observations and theory. We will discuss evidence that suggests that outburst radiation is emitted by a circumstellar disk rather than by the star and will briefly describe the thermal instability as a mechanism for outburst. Additional information is contained in the original extended abstract.

  2. Lightest Double-Lambda Hypernucleus

    NASA Astrophysics Data System (ADS)

    Nakaichi-Maeda, S.; Akaishi, Y.

    1990-12-01

    A variational calculation for (4) _{Lambda Lambda}H is made by employing the phenomenological N Lambda and Lambda Lambda potentials derived recently. It is shown that the binding of (4) _{Lambda Lambda}H below the Lambda+(3}_{Lambda) H threshold is consistent with the (6) _{Lambda Lambda}He data, and also with the (10) _{Lambda Lambda}Be data when repulsive alpha alpha Lambda and alpha Lambda Lambda three-body forces are considered.

  3. Molecular epidemiology of Escherichia coli O157:H7 strains by bacteriophage lambda restriction fragment length polymorphism analysis: application to a multistate foodborne outbreak and a day-care center cluster.

    PubMed Central

    Samadpour, M; Grimm, L M; Desai, B; Alfi, D; Ongerth, J E; Tarr, P I

    1993-01-01

    Genomic DNAs prepared from 168 isolates of Escherichia coli O157:H7 were analyzed for restriction fragment length polymorphisms on Southern blots probed with bacteriophage lambda DNA. The isolates analyzed included strains from a recent large multistate outbreak of E. coli O157:H7 infection associated with consumption of poorly cooked beef in restaurants, a day-care center cluster, and temporally and geographically unrelated isolates. E. coli O157:H7 isolates recovered from the incriminated meat and from 61 (96.8%) of 63 patients from Washington and Nevada possessed identical lambda restriction fragment length patterns. The lambda restriction fragment length polymorphisms observed in 11 (91.7%) of 12 day-care center patients were identical, but they differed from that of the strain associated with the multistate outbreak. E. coli O157:H7 from 42 patients temporally or geographically unrelated to either cluster of infection possessed unique and different lambda restriction fragment length patterns, except for paired isolates from three separate clusters of infection. These data demonstrate that the hybridization of DNA digests of E. coli O157:H7 with radiolabelled bacteriophage lambda DNA can be a useful, stable, and discriminatory epidemiologic tool for analyzing the linkage between strains of E. coli O157:H7. Images PMID:7905882

  4. The Evolution of FU Orionis Disks

    NASA Astrophysics Data System (ADS)

    Green, Joel D.

    2016-06-01

    Do protoplanetary disks undergo regular (or irregular) bursts of accretion? FU Orionis objects (FUors) are the strongest direct evidence for episodic accretion in low mass young stellar objects. FUors exhibit rapid changes in disk chemistry, both because they are temporarily bright IR sources relative to their core mass, and vary on day, month, year, and decade timescales. With improved spatial and spectral resolution from FORCAST, and a ten year time baseline compared with Spitzer-IRS data, we can observe and constrain the properties of silicate dust, and disk profiles, as they are altered by the outburst. We also consider the occurrence of binarity and whether any connection exists between multiplicity and evidence of recent outburst behavior.

  5. Binding energy of (Lambda)He-7 and test of charge symmetry breaking in the Lambda N interaction potential

    SciTech Connect

    Hashimoto, O; Honda, D; Kaneta, M; Kato, F; Kawama, D; Maruyama, N; Matsumura, A; Nakamura, S N; Nomura, H; Nonaka, K; Ohtani, A; Okayasu, Y; Osaka, M; Oyamada, M; Sumihama, M; Tamura, H; Baker, O K; Cole, L; Christy, M; Gueye, P; Keppel, C; Tang, L; Yuan, L; Acha, A; Baturin, P; Boeglin, W; Kramer, L; Markowitz, P; Pamela, P; Perez, N; Raue, B; Reinhold, J; Rivera, R; Kato, S; Sato, Y; Takahashi, T; Daniel, A; Hungerford, Ed V; Ispiryan, M; Kalantarians, N; Lan, K J; Li, Y; Miyoshi, T; Randeniya, S; Rodriguez, V M; Bosted, P; Carlini, R; Ent, R; Fenker, H; Gaskell, D; Jones, M; Mack, D; Roche, J; Smith, G; Tvaskis, V; Vulcan, W; Wood, S; Yan, C; Asaturyan, A; Asaturyan, R; Egiyan, K; Mkrtchyan, H; Margaryan, A; Navasardyan, T; Tadevosyan, V; Zamkochian, S; Hu, B; Song, Y; Luo, W; Androic, D; Furic, M; Petkovic, T; Seva, T; Ahmidouch, A; Danagoulian, S; Gasparian, A; Halkyard, R; Johnson, K; Simicevic, N; Wells, S; Niculescu, G; Niculescu, M I; Gan, L; Benmokhtar, F; Horn, T; Elassar, M; Gibson, E F

    2011-09-01

    The binding energy of 7LambdaHe has been obtained for the first time with reaction spectroscopy using the (e, e'K+) reaction at Jefferson Lab's Hall C. A comparison among the binding energies of the A = 7 T = l iso-triplet hypernuclei, 7LambdaHe, 7LambdaLi*and 7LambdaBe, is made and possible charge symmetry breaking (CSB) in the LambdaN potential is discussed. For 7LambdaHe and 7LambdaBe, the shifts in binding energies are opposite to those predicted by a recent cluster model calculation, which assumes that the unexplained part of the binding energy difference between 4LambdaH and 4LambdaHe, is due to the CSB of the LambdaN potential. Further examination of CSB in light hypernuclear systems is required both experimentally and theoretically.

  6. Spectroscopic Assessment of WISE-based Young Stellar Object Selection Near λ and σ Orionis

    NASA Astrophysics Data System (ADS)

    Koenig, Xavier; Hillenbrand, Lynne A.; Padgett, Deborah L.; DeFelippis, Daniel

    2015-10-01

    We have conducted a sensitive search down to the hydrogen burning limit for unextincted stars over ∼200 square degrees around Lambda Orionis and 20 square degrees around Sigma Orionis using the methodology of Koenig & Leisawitz. From WISE and 2MASS data we identify 544 and 418 candidate young stellar objects (YSOs) in the vicinity of λ and σ respectively. Based on our followup spectroscopy for some candidates and the existing literature for others, we found that ∼80% of the K14-selected candidates are probable or likely members of the Orion star-forming region. The yield from the photometric selection criteria shows that WISE sources with {K}S-w3\\gt 1.5 mag and KS between 10 and 12 mag are most likely to show spectroscopic signs of youth, while WISE sources with {K}S-w3 > 4 mag and {K}S\\gt 12 were often active galactic nuclei when followed up spectroscopically. The population of candidate YSOs traces known areas of active star formation, with a few new “hot spots” of activity near Lynds 1588 and 1589 and a more dispersed population of YSOs in the northern half of the H ii region bubble around σ and ɛ Ori. A minimal spanning tree analysis of the two regions to identify stellar groupings finds that roughly two-thirds of the YSO candidates in each region belong to groups of 5 or more members. The population of stars selected by WISE outside the MST groupings also contains spectroscopically verified YSOs, with a local stellar density as low as 0.5 stars per square degree.

  7. MULTIWAVELENGTH OBSERVATIONS OF V2775 Ori, AN OUTBURSTING PROTOSTAR IN L 1641: EXPLORING THE EDGE OF THE FU ORIONIS REGIME

    SciTech Connect

    Fischer, William J.; Megeath, S. Thomas; Kounkel, Marina; Tobin, John J.; Stutz, Amelia M.; Henning, Thomas; Ali, Babar; Stanke, Thomas; Osorio, Mayra; Wilson, T. L.

    2012-09-01

    Individual outbursting young stars are important laboratories for studying the physics of episodic accretion and the extent to which this phenomenon can explain the luminosity distribution of protostars. We present new and archival data for V2775 Ori (HOPS 223), a protostar in the L 1641 region of the Orion molecular clouds that was discovered by Caratti o Garatti et al. to have recently undergone an order-of-magnitude increase in luminosity. Our near-infrared spectra of the source have strong blueshifted He I {lambda}10830 absorption, strong H{sub 2}O and CO absorption, and no H I emission, all typical of FU Orionis sources. With data from the Infrared Telescope Facility, the Two Micron All Sky Survey, the Hubble Space Telescope, Spitzer, the Wide-field Infrared Survey Explorer, Herschel, and the Atacama Pathfinder Experiment that span from 1 to 70 {mu}m pre-outburst and from 1 to 870 {mu}m post-outburst, we estimate that the outburst began between 2005 April and 2007 March. We also model the pre- and post-outburst spectral energy distributions of the source, finding it to be in the late stages of accreting its envelope with a disk-to-star accretion rate that increased from {approx}2 Multiplication-Sign 10{sup -6} M{sub Sun} yr{sup -1} to {approx}10{sup -5} M{sub Sun} yr{sup -1} during the outburst. The post-outburst luminosity at the epoch of the FU Orionis-like near-IR spectra is 28 L{sub Sun }, making V2775 Ori the least luminous documented FU Orionis outburster with a protostellar envelope. The existence of low-luminosity outbursts supports the notion that a range of episiodic accretion phenomena can partially explain the observed spread in protostellar luminosities.

  8. Lambda Vision

    NASA Astrophysics Data System (ADS)

    Czajkowski, Michael

    2014-06-01

    There is an explosion in the quantity and quality of IMINT data being captured in Intelligence Surveillance and Reconnaissance (ISR) today. While automated exploitation techniques involving computer vision are arriving, only a few architectures can manage both the storage and bandwidth of large volumes of IMINT data and also present results to analysts quickly. Lockheed Martin Advanced Technology Laboratories (ATL) has been actively researching in the area of applying Big Data cloud computing techniques to computer vision applications. This paper presents the results of this work in adopting a Lambda Architecture to process and disseminate IMINT data using computer vision algorithms. The approach embodies an end-to-end solution by processing IMINT data from sensors to serving information products quickly to analysts, independent of the size of the data. The solution lies in dividing up the architecture into a speed layer for low-latent processing and a batch layer for higher quality answers at the expense of time, but in a robust and fault-tolerant way. This approach was evaluated using a large corpus of IMINT data collected by a C-130 Shadow Harvest sensor over Afghanistan from 2010 through 2012. The evaluation data corpus included full motion video from both narrow and wide area field-of-views. The evaluation was done on a scaled-out cloud infrastructure that is similar in composition to those found in the Intelligence Community. The paper shows experimental results to prove the scalability of the architecture and precision of its results using a computer vision algorithm designed to identify man-made objects in sparse data terrain.

  9. X-RAY VARIABILITY OF {sigma} ORIONIS YOUNG STARS AS OBSERVED WITH ROSAT

    SciTech Connect

    Caballero, J. A.; Lopez-Santiago, J.; De Castro, E.; Cornide, M.

    2009-06-15

    We used the Aladin Virtual Observatory tool and High Resolution Imager ROSAT archival data to search for X-ray variability in scale of days in 23 young stars in the {sigma} Orionis cluster and a background galaxy. Five stars displayed unambiguous flares and had probabilities p {sub var}>> 99% of being actual variables. Two of the detected flares were violent and long lasting, with maximum duration of six days and amplitude of eight times above the quiescent level. We classified another four stars as possible X-ray variables, including the binary system formed by the B2Vp star {sigma} Ori E and its close late-type companion. This makes a minimum frequency of high-amplitude X-ray variability in excess of a day of 39% among {sigma} Orionis stars. The incidence of this kind of X-ray variability seems to be lower among classical T Tauri stars with mid-infrared flux excesses than among fast-rotating, disk-less young stars.

  10. Orbits, Distance, and Stellar Masses of the Massive Triple Star σ Orionis

    NASA Astrophysics Data System (ADS)

    Schaefer, G. H.; Hummel, C. A.; Gies, D. R.; Zavala, R. T.; Monnier, J. D.; Walter, F. M.; Turner, N. H.; Baron, F.; ten Brummelaar, T.; Che, X.; Farrington, C. D.; Kraus, S.; Sturmann, J.; Sturmann, L.

    2016-12-01

    We present interferometric observations of the σ Orionis triple system using the CHARA Array, NPOI, and VLTI. Using these measurements, we spatially resolve the orbit of the close spectroscopic binary (Aa,Ab) for the first time and present a revised orbit for the wide pair (A,B). Combining the visual orbits with previously published radial velocity measurements and new radial velocities measured at CTIO, we derive dynamical masses for the three massive stars in the system of {M}{Aa} = 16.99 ± 0.20 {M}⊙ , {M}{Ab} = 12.81 ± 0.18 {M}⊙ , and {M}{{B}} = 11.5 ± 1.2 {M}⊙ . The inner and outer orbits in the triple are not coplanar, with a relative inclination of 120^\\circ -127^\\circ . The orbital parallax provides a precise distance of 387.5 ± 1.3 pc to the system. This is a significant improvement over previous estimates of the distance to the young σ Orionis cluster.

  11. Radio continuum from FU Orionis stars

    SciTech Connect

    Rodriguez, L.F.; Hartmann, L.W.; Chavira, E. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA Instituto Nacional de Astrofisica, Optica y Electronica, Puebla )

    1990-12-01

    Using the very large array a sensitive search is conducted for 3.6-cm continuum emission toward four FU Orionis objects: FU Ori, V1515 Cyg, V1057 Cyg, and Elias 1-12. V1057 Cyg and Elias 1-12 at the level of about 0.1 mJy is detected. The association of radio continuum emission with these FU Ori objects strengthens a possible relation between FU Ori stars and objects like L 1551 IRS 5 and Z CMa that are also sources of radio continuum emission and have been proposed as post-FU Ori objects. Whether the radio continuum emission is caused by free-free emission from ionized ejecta or if it is optically thin emission from a dusty disk is discussed. It was determined that, in the archives of the Tonantzintla Observatory, a plate taken in 1957 does not show Elias 1-12. This result significantly narrows the time range for the epoch of the outburst of this source to between 1957 and 1965. 38 refs.

  12. The Evolution of FU Orionis Disks

    NASA Astrophysics Data System (ADS)

    Green, Joel

    2015-10-01

    Mid-IR dust features occasionally vary dramatically in T Tauri stars, but are typically consistent over multiple epochs. Most T Tauri silicate features indicate both grain growth and high crystallinity fractions. In contrast, outbursting sources (FUors) exhibit some grain growth but pristine silicate emission features, hinting at modification of their protoplanetary disk chemistry, with resulting implications for planet formation. FUors are the best candidates to observe rapid changes in disks, both because they are unusually bright IR sources relative to their core mass, and vary on day, month, year, and decadal timescales. With improved spatial and spectral resolution from FORCAST, we can combine with Spitzer-IRS to observe and constrain the properties of silicate dust, and disk profiles, as they are altered by the outburst. We propose to observe five FU Orionis objects (FU Ori, V1057 Cyg, V1515 Cyg, V1735 Cyg, and V2775 Ori) in order to determine whether the outburst influences the dust feature or in- stead highlights a larger dust radius where processing has not yet occurred. This sample includes every FUor observed with Spitzer-IRS in 2005-8 that is detectable with FORCAST at sufficient S/N to sample the silicate feature. They represent a spread of FUor subtypes, and have declined in overall brightness at different rates, providing several different case studies. Their bright continuum provides the perfect opportunity for FORCAST spectroscopy, with a 7-10 year baseline to probe changes in their mid-IR properties. This will be the first mid-IR spectroscopic variability study of multi-year processes in FUors, producing calibrated spectra at better spectral and spatial resolution than previous epoch Spitzer-IRS data. We will search for changes in crystallinity fraction, grain growth, and continuum. We expect to observe signposts of dust processing and evolution providing time constraints on disk evolution, and input to planet formation models.

  13. VARIABILITY IN OPTICAL SPECTRA OF {epsilon} ORIONIS

    SciTech Connect

    Thompson, Gregory B.; Morrison, Nancy D. E-mail: nmorris@utnet.utoledo.edu

    2013-04-15

    We present the results of a time series analysis of 130 echelle spectra of {epsilon} Ori (B0 Ia), acquired over seven observing seasons between 1998 and 2006 at Ritter Observatory. The equivalent widths of H{alpha} (net) and He I {lambda}5876 were measured and radial velocities were obtained from the central absorption of He I {lambda}5876. Temporal variance spectra (TVS) revealed significant wind variability in both H{alpha} and He I {lambda}5876. The He I TVS have a double-peaked profile consistent with radial velocity oscillations. A periodicity search was carried out on the equivalent width and radial velocity data, as well as on wavelength-binned spectra. This analysis has revealed several periods in the variability with timescales of two to seven days. Many of these periods exhibit sinusoidal modulation in the associated phase diagrams. Several of these periods were present in both H{alpha} and He I, indicating a possible connection between the wind and the photosphere. Due to the harmonic nature of these periods, stellar pulsations may be the origin of some of the observed variability. Periods on the order of the rotational period were also detected in the He I line in the 1998-1999 season and in both lines during the 2004-2005 season. These periods may indicate rotational modulation due to structure in the wind.

  14. The low-mass star and sub-stellar populations of the 25 Orionis group

    NASA Astrophysics Data System (ADS)

    Downes, Juan José; Briceño, César; Mateu, Cecilia; Hernández, Jesús; Vivas, Anna Katherina; Calvet, Nuria; Hartmann, Lee; Petr-Gotzens, Monika G.; Allen, Lori

    2014-10-01

    We present the results of a survey of the low-mass star and brown dwarf population of the 25 Orionis group. Using optical photometry from the CIDA (Centro de Investigaciones de Astronomía `Francisco J. Duarte', Mérida, Venezuela) Deep Survey of Orion, near-IR photometry from the Visible and Infrared Survey Telescope for Astronomy and low-resolution spectroscopy obtained with Hectospec at the MMT telescope, we selected 1246 photometric candidates to low-mass stars and brown dwarfs with estimated masses within 0.02 ≲ M/M⊙ ≲ 0.8 and spectroscopically confirmed a sample of 77 low-mass stars as new members of the cluster with a mean age of ˜7 Myr. We have obtained a system initial mass function of the group that can be well described by either a Kroupa power-law function with indices α3 = -1.73 ± 0.31 and α2 = 0.68 ± 0.41 in the mass ranges 0.03 ≤ M/M⊙ ≤ 0.08 and 0.08 ≤ M/M⊙ ≤ 0.5, respectively, or a Scalo lognormal function with coefficients m_c=0.21^{+0.02}_{-0.02} and σ = 0.36 ± 0.03 in the mass range 0.03 ≤ M/M⊙ ≤ 0.8. From the analysis of the spatial distribution of this numerous candidate sample, we have confirmed the east-west elongation of the 25 Orionis group observed in previous works, and rule out a possible southern extension of the group. We find that the spatial distributions of low-mass stars and brown dwarfs in 25 Orionis are statistically indistinguishable. Finally, we found that the fraction of brown dwarfs showing IR excesses is higher than for low-mass stars, supporting the scenario in which the evolution of circumstellar discs around the least massive objects could be more prolonged.

  15. Is HL Tauri and FU Orionis system in quiescence?

    NASA Technical Reports Server (NTRS)

    Lin, D. N. C.; Hayashi, M.; Bell, K. R.; Ohashi, N.

    1994-01-01

    A recent Nobeyama map of HL Tau reveals that gas is infalling in a flattened region approximately 1400 AU around the central star. The apparent motion of the gas provides the necessary condition for the formation of a Keplerian disk with a radius comparable to the size of the primordial solar nebula. The inferred mass infall rate onto the disk is approximately equal to 5 x 10(exp -6) solar mass/yr, which greatly exceeds the maximum estimate of the accretion rate onto the central star (approximately 7 x 10(exp -7) solar mass/yr). Consequently, mass must currently be accumulating in the disk. The estimated age and disk mass of HL Tau suggest that the accumulated matter has been flushed repeatedly on a timescale less than 10(exp 4) yr. Based on the similarites between their evolution patterns, we propose that HL Tau is an FU Orionis system in quiescence. In addition to HL Tau, 14 out of 86 pre-main-sequence stars in the Taurus-Auriga dark clouds have infrared luminosities much greater than their otherwise normal extinction-corrected stellar luminosities. These sources also tend to have flat spectra which may be due to the reprocessing of radiation by dusty, flattened, collapsing envelopes with infall rates a few 10(exp -6) solar mass/yr. Such rates are much larger than estimated central accretion rates for these systems, which suggests that mass must also be accumulating in these disks. If these sources are FU Orionis stars in quiescence, similar to HL Tau, their age and relative abundance imply that the FU Orionis phase occurs over a timescale of approixmately 10(exp 5) yr, and the quiescent phase between each outburst lasts approximately 10(exp 3) =10(exp 4) yr. These inferred properties are compatible with the scenario that FU Orionis outbursts are regulated by a thermal instability in the inner region of the disk.

  16. Amorphous alumina in the extended atmosphere of α Orionis

    NASA Astrophysics Data System (ADS)

    Verhoelst, T.; Decin, L.; van Malderen, R.; Hony, S.; Cami, J.; Eriksson, K.; Perrin, G.; Deroo, P.; Vandenbussche, B.; Waters, L. B. F. M.

    2006-02-01

    In this paper we study the extended atmosphere of the late-type supergiant α Orionis. Infrared spectroscopy of red supergiants reveals strong molecular bands, some of which do not originate in the photosphere but in a cooler layer of molecular material above it. Lately, these layers have been spatially resolved by near and mid-IR interferometry. In this paper, we try to reconcile the IR interferometric and ISO-SWS spectroscopic results on α Orionis with a thorough modelling of the photosphere, molecular layer(s) and dust shell. From the ISO and near-IR interferometric observations, we find that α Orionis has only a very low density water layer close above the photosphere. However, mid-IR interferometric observations and a narrow-slit N-band spectrum suggest much larger extra-photospheric opacity close to the photosphere at those wavelengths, even when taking into account the detached dust shell. We argue that this cannot be due to the water layer, and that another source of mid-IR opacity must be present. We show that this opacity source is probably neither molecular nor chromospheric. Rather, we present amorphous alumina (Al2O3) as the best candidate and discuss this hypothesis in the framework of dust-condensation scenarios.

  17. The Mid-infrared Evolution of the FU Orionis Disk

    NASA Astrophysics Data System (ADS)

    Green, Joel D.; Jones, Olivia C.; Keller, Luke D.; Poteet, Charles A.; Yang, Yao-Lun; Fischer, William J.; Evans, Neal J., II; Sargent, Benjamin A.; Rebull, Luisa M.

    2016-11-01

    We present new SOFIA-FORCAST observations obtained in 2016 February of the archetypal outbursting low-mass young stellar object FU Orionis, and we compare the continuum, solid-state, and gas properties with mid-infrared data obtained at the same wavelengths in 2004 with Spitzer-IRS. In this study, we conduct the first mid-infrared spectroscopic comparison of an FUor over a long time period. Over a 12-year period, UBVR monitoring indicates that FU Orionis has continued its steady decrease in overall brightness by ˜14%. We find that this decrease in luminosity occurs only at wavelengths ≲20 μm. In particular, the continuum shortward of the silicate emission complex at 10 μm exhibits a ˜12% (˜3σ) drop in flux density but no apparent change in slope; both the Spitzer and SOFIA spectra are consistent with a 7200 K blackbody. Additionally, the detection of water absorption is consistent with the Spitzer spectrum. The silicate emission feature at 10 μm continues to be consistent with unprocessed grains, unchanged over 12 years. We conclude that either the accretion rate in FU Orionis has decreased by ˜12-14% over this time baseline or the inner disk has cooled, but the accretion disk remains in a superheated state outside the innermost region.

  18. The Impact of FU Orionis Outbursts and the Solar Nebula

    NASA Technical Reports Server (NTRS)

    Bell, Robbins; Young, Richard E. (Technical Monitor)

    1998-01-01

    Protostellar systems are variable on many timescales. One of the most dramatic forms of variability known to occur in low mass stellar systems is the FU Orionis outburst (Herbig 1977). Throughout a typical outburst lasting several decades, system luminosities may be a hundred times what is typical of the quiesent state. FU Orionis outburst events are thought to have significant impact on the thermal structure of the protosolar nebula; their existence has been used to explain features in the meteoritic record from thermally induced homogenization to the formation of chondrules. Until recently, the magnitude of the likely effect from such outbursts has been largely speculative due to the lack of a detailed understanding of the outburst mechanism. Recent numerical models (Bell\\& Lin 1994) have demonstrated the viability of the observational hypothesis (Hartmann\\& Kenyon 1985) that the radiation observed during outburst is emitted by a luminous circumstellar disk transporting mass at a thousand times the quiesent rate. Light curves and color and line width evolution observed in FU Orionis systems are naturally explained by time dependent outbursting model disks (Bell et al. 1995). The radial temperature structure and shape of the disk during outburst derived from these models may be used to calculate the outburst's expected impact on primitive material at various radii throughout the disk. In this review, we will begin by discussing what is known about the FU Orionis outburst phenomenon from recent observations and theory including statistically deduced outburst timescales and observed peak temperatures. Unless covered by another author, we will discuss the evidence which suggests that outburst radiation is emitted by a circumstellar disk rather than by the star and will briefly review the thermal instability as a mechanism for outburst. We will then report on recent work which investigates the likely heating of solar nebula material due to FU Orionis outbursts

  19. What does the free space Lambda Lambda interaction predict for Lambda Lambda hypernuclei?

    PubMed

    Albertus, C; Amaro, J E; Nieves, J

    2002-07-15

    Data on LambdaLambda hypernuclei provide a unique method to learn details about the strangeness S = -2 sector of the baryon-baryon interaction. From the free space Bonn-Jülich potentials, determined from data on baryon-baryon scattering in the S = 0,-1 channels, we construct an interaction in the S = -2 sector to describe the experimentally known LambdaLambda hypernuclei. After including short-range (Jastrow) and RPA correlations, we find masses for these LambdaLambda hypernuclei in a reasonable agreement with data, taking into account theoretical and experimental uncertainties. Thus, we provide a natural extension, at low energies, of the Bonn-Jülich one-boson exchange potentials to the S = -2 channel.

  20. A quark model of {bar {Lambda}}{Lambda} production in {bar p}p interactions

    SciTech Connect

    Alberg, M.A. |; Henley, E.M.; Wilets, L.; Kunz, P.D.

    1993-12-31

    A quark model which includes both scalar and vector contributions to the reaction mechanism (SV quark model) is used in a DWBA calculation of {anti {Lambda}}{Lambda} production in {bar p}p interactions. Total and differential cross-sections, polarizations, depolarizations, and spin-correlation coefficients are computed for laboratory momenta from threshold to 1695 MeV/c. The free parameters of the calculation are the scalar and vector strengths, a quark cluster size parameter, and the parameters of the unknown {anti {Lambda}}{Lambda} potentials. Good agreement with experiment is found for constructive interference of the scalar and vector terms, and for {anti {Lambda}}{Lambda} potentials which differ from those suggested by several authors on the basis of SU(3) arguments. The fit to the data is better than that obtained by other quark models, which use only scalar or vector annihilation terms. The agreement with experiment is also better than that found in meson-exchange models. The recent suggestion [1] that measurement of the depolarization parameter D{sub nn} can be used to discriminate between meson-exchange and quark models is examined in detail. We conclude that a measurement of D{sub nn} will provide a test of which of these models, as presently constructed, is the more appropriate description of strangeness production in the {bar p}p {yields} {anti {Lambda}}{Lambda} reaction.

  1. BF Orionis - Evidence for an infalling circumstellar envelope

    NASA Technical Reports Server (NTRS)

    Welty, Alan D.; Barden, Samuel C.; Huenemoerder, David P.; Ramsey, Lawrence W.

    1992-01-01

    Analysis of the optical magnitudes and Balmer lines of the Herbig Ae/Be star BF Orionis confirm that the object is an early to mid A-type star, but appears to be below the zero-age main sequence. Enhanced metal-line strengths (once thought to link BF Ori with the Am stars), line asymmetries, and radial velocities are shown to be signatures of an infalling circumstellar envelope. The possibility that BF Ori has a late-type companion is examined, and it is concluded that it does not.

  2. Somatic mutation in constant regions of mouse lambda 1 light chains.

    PubMed Central

    Motoyama, N; Okada, H; Azuma, T

    1991-01-01

    To study the distribution of somatic mutation, we determined nucleotide sequences of rearranged lambda 1-chain genomic DNA from four hybridomas obtained from C57BL/6 mice that had been immunized with (4-hydroxy-3-nitrophenyl)acetyl-conjugated chicken gamma globulin. In total, 114 nucleotide substitutions were observed, with neither insertion nor deletion. Sixty-one mutations occurred in the variable-joining region genes (V lambda 1-J lambda 1) and 49 in joining-constant (J lambda 1-C lambda 1) introns. Although frequency decreased with distance from the V lambda 1-J lambda 1 coding region, somatic mutations occurred in the entire J lambda 1-C lambda 1 intron and even in the C lambda 1 region. We found four nucleotide substitutions in C lambda 1 genes, all of which were replacement mutations. Therefore, the mechanism responsible for somatic mutation is operative into the C lambda 1 exons. Nucleotide sequences of rearranged but inactive lambda 2-chain genes from two hybridomas were also examined and compared with those of lambda 1-chain genes. The clustering of replacement mutations in complementarity-determining regions in the inactive lambda 2-chain genes similar to the active lambda 1-chain genes suggested a mechanism that induces somatic mutation preferentially in this region even in the absence of antigenic selection. PMID:1910169

  3. V346 Normae: first post-outburst observations of an FU Orionis star

    NASA Astrophysics Data System (ADS)

    Kraus, S.; Caratti o Garatti, A.; Garcia-Lopez, R.; Kreplin, A.; Aarnio, A.; Monnier, J. D.; Naylor, T.; Weigelt, G.

    2016-10-01

    During their formation phase, stars gain most of their mass in violent episodic accretion events, such as observed in FU Orionis (FUor) and EXor stars. V346 Normae is a well-studied FUor that underwent a strong outburst beginning around 1980. Here, we report on photometric and spectroscopic observations, which show that the visual/near-infrared brightness has decreased dramatically between the 1990s and 2010 (ΔR ≈ 10.9 mag, ΔJ ≈ 7.8 mag and ΔK ≈ 5.8 mag). The spectral properties of this fading event cannot be explained by variable extinction alone, but indicate a drop in accretion rate by two to three orders of magnitude. This is the first time that a member of the FUor class has been observed to switch to a very low accretion phase. Remarkably, in the last few years (2011-2015) V346 Nor has brightened again at all near-infrared wavelengths, indicating the onset of a new outburst event. The observed behaviour might be consistent with the clustered luminosity bursts that have been predicted by recent gravitational instability and fragmentation models for the early stages of protostellar evolution. Given V346 Nor's unique characteristics (concerning outburst duration, repetition frequency and spectroscopic diagnostics), our results also highlight the need to revisit the FUor/EXor classification scheme.

  4. Measurement of the Lambda b lifetime in the exclusive decay Lambda b --> J/psi Lambda.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Jesus, A C S Assis; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K; Chan, K M; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J M; Kalk, J R; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lam, D; Lammers, S; Landsberg, G; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, L; Li, Q Z; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; O'dell, V; O'neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Otero Y Garzón, G J; Owen, M; Padley, P; Pangilinan, M; Panikashvili, N; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Pompos, A; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schliephake, T; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, R P; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Tanasijczuk, A; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; van Eijk, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, C; Yu, J; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G

    2007-10-05

    We have measured the Lambda b lifetime using the exclusive decay Lambda b --> J/psi Lambda, based on 1.2 fb(-1) of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda b decays, where the J/psi and Lambda are identified via the decays J/psi --> mu+ mu- and Lambda --> ppi, we measured the Lambda b lifetime to be tau(Lambda b)=1.218 (+0.130)/(-0.115) (stat) +/- 0.042(syst) ps. We also measured the B0 lifetime in the decay B0 --> J/psi(mu+ mu-)K(0)/(S)(pi+ pi-) to be tau(B0)=1.501 (+0.078)/(-0.074) (stat) +/- 0.050(syst) ps, yielding a lifetime ratio of tau(Lambda b)/tau(B0)=0.811 (+0.096)/(-0.087) (stat) +/- 0.034(syst).

  5. Life of Lambda

    ERIC Educational Resources Information Center

    Futhey, Tracy

    2005-01-01

    In this column, the author discusses the four key questions related to the National LambdaRail (NLR) networking technology. NLR uses Dense Wave Division Multiplexing (DWDM) to enable multiple networks to coexist on a national fiber footprint, and is owned and operated not by carriers, but by the research and education community. The NLR Board…

  6. Highly efficient tabletop x-ray laser at {lambda}=41.8 nm in Pd-like xenon pumped by optical-field ionization in a cluster jet

    SciTech Connect

    Ivanova, E. P.

    2011-10-15

    The atomic-kinetic calculations of gain at 41.8 nm in Pd-like xenon are performed. The interpretation of known experiments has proved that x-ray laser in Pd-like xenon is feasible in the extremely wide range of atomic densities: 10{sup 17}{<=}[Xe{sup 8+}]{<=} 3 x 10{sup 19} cm{sup -3}. This result is due to the large cross sections (and rates) of level excitations in Pd-like xenon by electron impact. We propose a highly efficient tabletop x-ray laser pumped by optical-field ionization in a xenon cluster jet. The efficiency of {approx}0.5% is possible with a pump laser pulse energy of {>=}0.001 J and an intensity of {approx}10{sup 16} W/cm{sup 2}.

  7. AN X-RAY SURVEY OF THE YOUNG STELLAR POPULATION OF THE LYNDS 1641 AND IOTA ORIONIS REGIONS

    SciTech Connect

    Pillitteri, I.; Wolk, S. J.; Myers, P.; Walter, F.; Megeath, S. T.; Allen, L.; Bally, J.; Gagne, M.; Gutermuth, R. A.; Hartman, L.; Micela, G.; Sciortino, S.; Oliveira, J. M.; Rebull, L.; Stauffer, J.

    2013-05-10

    We present an XMM-Newton survey of the part of the Orion A cloud south of the Orion Nebula. This survey includes the Lynds 1641 (L1641) dark cloud, a region of the Orion A cloud with very few massive stars and hence a relatively low ambient UV flux, and the region around the O9 III star {iota} Orionis. In addition to proprietary data, we used archival XMM data of the Orion Nebula Cluster (ONC) to extend our analysis to a major fraction of the Orion A cloud. We have detected 1060 X-ray sources in L1641 and the {iota} Ori region. About 94% of the sources have Two Micron All Sky Survey and Spitzer counterparts, 204 and 23 being Class II and Class I or protostar objects, respectively. In addition, we have identified 489 X-ray sources as counterparts to Class III candidates, given they are bright in X-rays and appear as normal photospheres at mid-IR wavelengths. The remaining 205 X-ray sources are likely distant active galactic nuclei or other galactic sources not related to Orion A. We find that Class III candidates appear more concentrated in two main clusters in L1641. The first cluster of Class III stars is found toward the northern part of L1641, concentrated around {iota} Ori. The stars in this cluster are more evolved than those in the Orion Nebula. We estimate a distance of 300-320 pc for this cluster showing that it is in the foreground of the Orion A cloud. Another cluster rich in Class III stars is located in L1641 South and appears to be a slightly older cluster embedded in the Orion A cloud. Furthermore, other evolved Class III stars are found north of the ONC toward NGC 1977.

  8. High Cadence Time-Series Photometry of V1647 Orionis

    NASA Astrophysics Data System (ADS)

    Bastien, Fabienne A.; Stassun, K. G.; Weintraub, D. A.

    2010-01-01

    We present high cadence time-series photometry of the 2003-2004 and 2008-2009 FUor/EXor outbursts of V1647 Orionis, the star illuminating McNeil's Nebula. The first dataset was taken as the object was most steeply increasing in brightness while the second was presumably taken after its luminosity had plateaued. We detect two significant periods in our 2003 lightcurve superimposed on a flicker-noise spectrum, while the power spectrum of our 2009 lightcurve is devoid of significant structure. We find that neither of these periods can be attributed to the star's rotation. The dominant period is 4.3d, and we find that it may be akin to the dwarf-nova oscillations observed around cataclysmic variable stars. This 4.3d period would suggest that the inner edge of the star's Keplerian accretion disk was located 2.5 stellar radii away from the star before its luminosity had reached its peak and that, considered together with the flickering, the stellar magnetosphere was interacting with the disk during this phase of the outburst. The second period of 0.13d is consistent with the star's theoretical radial pulsation timescale, and, given that this period is not detected in 2009, we propose that the very high accretion rate at the time of our 2003 observations induced short-term radial pulsations in the star.

  9. X-ray Variability in the Hot Supergiant zgr Orionis.

    PubMed

    Berghöfer, T W; Schmitt, J H

    1994-09-16

    Hot massive stars represent only a small fraction of the stellar population of the galaxy, but their enormous luminosities make them visible over large distances. Therefore, they are ideal standard candles, used to determine distances of near galaxies. Their mass loss due to supersonic winds driven by radiation pressure contributes significantly to the interstellar medium and thus to the chemical evolution of galaxies. All hot stars are soft x-ray sources; in contrast to the sun with its highly variable x-ray flux, long time scale x-ray variability is not common among hot stars. An analysis is presented here of an unusual increase in x-ray flux observed with the roentgen observatory satellite during a period of 2 days for the hot supergiant zeta Orionis, the only episode of x-ray variability that has been found in a hot star. These observations provide the most direct evidence so far for the scenario of shock-heated gas in the winds of hot stars.

  10. Very low-luminosity Class I/flat outflow sources in σ Orionis

    NASA Astrophysics Data System (ADS)

    Riaz, B.; Thompson, M.; Whelan, E. T.; Lodieu, N.

    2015-01-01

    We present an optical to submillimetre multiwavelength study of two very low-luminosity Class I/flat systems, Mayrit 1701117 and Mayrit 1082188, in the σ Orionis cluster. We performed moderate-resolution (R ˜ 1000) optical (˜0.4-0.9 μm) spectroscopy with the Cassegrain Twin Spectrograph (TWIN) spectrograph at the Calar Alto 3.5-m telescope. The spectra for both sources show prominent emission in accretion- and outflow-associated lines. The mean accretion rate measured from multiple line diagnostics is 6.4 × 10-10 M⊙ yr-1 for Mayrit 1701117 and 2.5 × 10-10 M⊙ yr-1 for Mayrit 1082188. The outflow mass-loss rates for the two systems are similar and estimated to be ˜1 × 10-9 M⊙ yr-1. The activity rates are within the range observed for low-mass Class I protostars. We obtained submillimetre continuum observations with the Submillimetre Common-User Bolometer Array (SCUBA-2) bolometer at the James Clerk Maxwell Telescope. Both objects are detected at a ≥5σ level in the SCUBA-2 850-μm band. The bolometric luminosity of the targets as measured from the observed spectral energy distribution over ˜0.8-850 μm is 0.18 ± 0.04 L⊙ for Mayrit 1701117 and 0.16 ± 0.03 L⊙ for Mayrit 1082188 and is in the very low mass range. The total dust+gas mass derived from submillimetre fluxes is ˜36 MJup and ˜22 MJup for Mayrit 1701117 and Mayrit 1082188, respectively. There is the possibility that some of the envelope material might be dissipated by the strong outflows driven by these sources, resulting in a final mass of the system close to or below the substellar limit.

  11. Study of the ^7_{Lambda}He hypernucleus in formalism of the Faddeev equations

    SciTech Connect

    Igor Filikhin; Vladimir M. Suslov; Branislav Vlahovic

    2006-02-01

    P-shell A = 7 hypernuclei are considered in the cluster {sub {Lambda}}{sup 5}He + N + N model. The folding procedure are applied to construct the {sub {Lambda}}{sup 5}He-N interaction. We use the OBE simulating NSC97f potential for {Lambda}N interaction and various phenomenological potentials for {alpha}{Lambda} interaction. Configuration space Faddeev calculations are performed for hyperon binding energy of the {sub {Lambda}}{sup 7}He(1/2{sup +}) and {sub {lambda}}{sup 7}Li(1/2{sup +} and 3/2{sup +}, T=0) nuclei. Predicted value for B{sub {Lambda}}({sub {Lambda}}{sup 7}He) is 5.35 MeV. This value is obtained when the {sup {Lambda}}{sup 6}He(2{sup -}) excitation energy is equal 0.26 MeV by the adjustment of pair {sub {Lambda}}{sup 5}He-N effective potential to reproduce the experimental value of the {sub {Lambda}}{sup 7}Li(3/2{sup +}) excitation energy. Our results are compared with those of E. Hiyama et al.

  12. Effects of FU Orionis Outbursts on Protoplanetary Disks

    NASA Technical Reports Server (NTRS)

    Bodenheimer, Peter

    1997-01-01

    In the early stages of work under this grant, we developed simulations to match the light curves of the three best studied systems: FU Ori, V1515 Cyg, & V1057 Cyg (Bell et al. 1995). We compared the details of model results to observations to test the validity of the thermal ionization instability model for outburst. In this paper, we were able to answer several of the key objections to the accretion disk outburst model for the FU Orionis phenomenon (eg. Herbig 1989). The declines in line width and reddening observed in V1057 Cyg following peak light had been used as arguments against the disk instability model. We showed these effects to be natural consequences of the slow outward progression and limited radial excursion of the ionization front during outburst. By the end of the grant period, we had begun combining the inner and outer disk models to derive the radiation expected in the planet forming region of the disk. A crucial step in this was the development of a radiative transfer model of the complete inner and outer disk system (Turner, Bodenheimer, & Bell 1997). In this work, wavelength dependent opacities were used to synthesize images and spectral energy distributions of FU Ori objects. New detailed opacities provided by Alexander (1995) allowed the resolution of coarse features such as silicate emission lines. Data for the fits were taken from the time dependent simulations in Bell et al. (1995) to which was added the effect of disk to disk or "self"-reprocessing which accounts for the illumination of the outer disk by the inner disk (Bell 1998). Through the course of work on this grant we have made considerable progress in computing detailed models of both the active outburst region of the disk and the outer quiescent disk. We have begun an investigation into the effects of a cocooning envelope. Direct comparisons with observations lend confidence that the basic underlying assumptions of the outburst model are reasonable. We are now ready to build upon

  13. Variability at the Edge: Optical Near/IR Rapid-cadence Monitoring of Newly Outbursting FU Orionis Object HBC 722

    NASA Astrophysics Data System (ADS)

    Green, Joel D.; Robertson, Paul; Baek, Giseon; Pooley, David; Pak, Soojong; Im, Myungshin; Lee, Jeong-Eun; Jeon, Yiseul; Choi, Changsu; Meschiari, Stefano

    2013-02-01

    We present the detection of day-timescale periodic variability in the r-band lightcurve of newly outbursting FU Orionis-type object HBC 722, taken from >42 nights of observation with the CQUEAN instrument on the McDonald Observatory 2.1 m telescope. The optical/near-IR lightcurve of HBC 722 shows a complex array of periodic variability, clustering around 5.8-day (0.044 mag amplitude) and 1.28-day (0.016 mag amplitude) periods, after removal of overall baseline variation. We attribute the unusual number of comparable strength signals to a phenomenon related to the temporary increase in accretion rate associated with FUors. We consider semi-random "flickering," magnetic braking/field compression and rotational asymmetries in the disk instability region as potential sources of variability. Assuming that the 5.8-day period is due to stellar rotation and the 1.28-day period is indicative of Keplerian rotation at the inner radius of the accretion disk (at 2 R sstarf), we derive a B-field strength of 2.2-2.7 kG, slightly larger than typical T Tauri stars. If instead the 5.8-day signal is from a disk asymmetry, the instability region has an outer radius of 5.4 R sstarf, consistent with models of FUor disks. Further exploration of the time domain in this complicated source and related objects will be key to understanding accretion processes.

  14. VARIABILITY AT THE EDGE: OPTICAL NEAR/IR RAPID-CADENCE MONITORING OF NEWLY OUTBURSTING FU ORIONIS OBJECT HBC 722

    SciTech Connect

    Green, Joel D.; Robertson, Paul; Pak, Soojong; Meschiari, Stefano; Baek, Giseon; Lee, Jeong-Eun; Pooley, David; Im, Myungshin; Jeon, Yiseul; Choi, Changsu

    2013-02-10

    We present the detection of day-timescale periodic variability in the r-band lightcurve of newly outbursting FU Orionis-type object HBC 722, taken from >42 nights of observation with the CQUEAN instrument on the McDonald Observatory 2.1 m telescope. The optical/near-IR lightcurve of HBC 722 shows a complex array of periodic variability, clustering around 5.8-day (0.044 mag amplitude) and 1.28-day (0.016 mag amplitude) periods, after removal of overall baseline variation. We attribute the unusual number of comparable strength signals to a phenomenon related to the temporary increase in accretion rate associated with FUors. We consider semi-random 'flickering', magnetic braking/field compression and rotational asymmetries in the disk instability region as potential sources of variability. Assuming that the 5.8-day period is due to stellar rotation and the 1.28-day period is indicative of Keplerian rotation at the inner radius of the accretion disk (at 2 R {sub *}), we derive a B-field strength of 2.2-2.7 kG, slightly larger than typical T Tauri stars. If instead the 5.8-day signal is from a disk asymmetry, the instability region has an outer radius of 5.4 R {sub *}, consistent with models of FUor disks. Further exploration of the time domain in this complicated source and related objects will be key to understanding accretion processes.

  15. {Lambda} single-particle energies

    SciTech Connect

    Bodmer, A.R.; Usmani, Q.N.; Sami, M.

    1995-08-01

    We are continuing our work on the {Lambda} hyperon single-particle (s.p.) energies and their interpretation in terms of the basic {Lambda}-nuclear interactions. In particular we are interpreting the results obtained by S.C. Pieper, A. Usmani and Q.N. Usmani. We obtain about 30 MeV for the repulsive contribution of the three-body {Lambda}NN forces in nuclear matter. We are able to exclude purely {open_quotes}dispersive{close_quotes} {Lambda}NN forces. We are investigating the mix of dispersive and two-pion-exchange {Lambda}NN forces which provide a fit to the s.p. data. For interactions, which provide a fit to the s.p. data, the {Lambda} binding energy as a function of the nuclear matter density shows characteristic saturation features with a maximum at a density not very different from that of normal nuclear matter. We obtain a more precise measure of the space-exchange part of the {Lambda}-nuclear force than was previously available, corresponding to an exchange parameter {approx_equal} 0.32. The space-exchange force is rather directly related to the effective mass of a {Lambda} in the nuclear medium and turns out to be about 70% of its free mass. As a result, we also obtain a much better value for the p-state {Lambda}-nucleus potential which is about 40% of the s-state potential. The A binding to nuclear matter is determined to be {approx_equal} 28 MeV.

  16. 25 Orionis: A Kinematically Distinct 10 Myr Old Group in Orion OB1a

    NASA Astrophysics Data System (ADS)

    Briceño, César; Hartmann, Lee; Hernández, Jesús; Calvet, Nuria; Vivas, A. Katherina; Furesz, Gabor; Szentgyorgyi, Andrew

    2007-06-01

    We report here on the photometric and kinematic properties of a well-defined group of nearly 200 low-mass pre-main-sequence stars, concentrated within ~1° of the early-B star 25 Ori, in the Orion OB1a subassociation. We refer to this stellar aggregate as the 25 Orionis group. The group also harbors the Herbig Ae/Be star V346 Ori and a dozen other early-type stars with photometry, parallaxes, and some with IR excess emission, indicative of group membership. The number of high- and low-mass stars is in agreement with expectations from a standard initial mass function. The velocity distribution for the low-mass stars shows a narrow peak at 19.7 km s-1, offset ~-10 km s-1 from the velocity characterizing the younger stars of the Ori OB1b subassociation, and -4 km s-1 from the velocity of widely spread young stars of the Ori OB1a population; this result provides new and compelling evidence that the 25 Ori group is a distinct kinematic entity, and that considerable space and velocity structure is present in the Ori OB1a subassociation. The low-mass members follow a well-defined band in the color-magnitude diagram, consistent with an isochronal age of ~7-10 Myr. The ~2 time drop in the overall Li I equivalent widths and accretion fraction between the younger Ori OB1b and the 25 Ori group is consistent with the latter being significantly older. In a simple-minded kinematic evolution scenario, the 25 Ori group may represent the evolved counterpart of the younger σ Ori cluster. The 25 Ori stellar aggregate is the most populous ~10 Myr sample yet known within 500 pc, setting it as an excellent laboratory to study the evolution of solar-like stars and protoplanetary disks. Based on observations obtained at the Llano del Hato National Astronomical Observatory of Venezuela, operated by CIDA for the Ministerio de Ciencia y Tecnología the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona; and the Fred Lawrence Whipple Observatory of

  17. Chromosomal orientation of the lambda light chain locus: V lambda is proximal to C lambda in 22q11.

    PubMed Central

    Emanuel, B S; Cannizzaro, L A; Magrath, I; Tsujimoto, Y; Nowell, P C; Croce, C M

    1985-01-01

    We have demonstrated that the chromosomal breakpoint at 22q11 of a Burkitt lymphoma cell line (PA682) with an 8;22 translocation interrupts the variable region of the lambda light chain locus. In these cells, all of the C lambda and some V lambda sequences translocate to the 8q+ chromosome whereas some V lambda sequences remain on the 22q-. These results indicate that the lambda light chain locus on the long arm of chromosome 22 is oriented such that V lambda is proximal to C lambda. Images PMID:3923432

  18. X-RAY EMISSION FROM THE FU ORIONIS STAR V1735 CYGNI

    SciTech Connect

    Skinner, Stephen L.; Sokal, Kimberly R.; Guedel, Manuel; Briggs, Kevin R.

    2009-05-01

    The variable star V1735 Cyg (=Elias 1-12) lies in the IC 5146 dark cloud and is a member of the class of FU Orionis objects whose dramatic optical brightenings are thought to be linked to episodic accretion. We report the first X-ray detections of V1735 Cyg and a deeply embedded class I protostar lying 24'' to its northeast. X-ray spectra obtained with EPIC on XMM-Newton reveal very high-temperature plasma (kT > 5 keV) in both objects, but no large flares. Such hard X-ray emission is not anticipated from accretion shocks and is a signature of magnetic processes. We place these new results into the context of what is presently known about the X-ray properties of FU Orionis stars and other accreting young stellar objects.

  19. A THIRD MASSIVE STAR COMPONENT IN THE {sigma} ORIONIS AB SYSTEM

    SciTech Connect

    Simon-Diaz, S.; Caballero, J. A.; Lorenzo, J.

    2011-11-20

    We report on the detection of a third massive star component in the {sigma} Orionis AB system, traditionally considered as a binary system. The system has been monitored by the IACOB Spectroscopic Survey of Northern Massive Stars program, obtaining 23 high-resolution FIES-NOT spectra with a time span of {approx}2.5 years. The analysis of the radial velocity curves of the two spectroscopic components observed in the spectra has allowed us to obtain the orbital parameters of the system, resulting in a high eccentric orbit (e {approx} 0.78) with an orbital period of 143.5 {+-} 0.5 days. This result implies the actual presence of three stars in the {sigma} Orionis AB system when combined with previous results obtained from the study of the astrometric orbit (with an estimated period of {approx}157 years).

  20. Zeeman effect in the X-ray star candidates HD 77581 and theta super 2 Orionis.

    NASA Technical Reports Server (NTRS)

    Kemp, J. C.; Wolstencroft, R. D.

    1973-01-01

    The discovery of Zeeman effects is reported in HD 77581 and theta super 2 Orionis, optical candidates for the X-ray sources Vela XR-1 and 2U 0525-06, respectively. The maximum longitudinal magnetic fields recorded were -10,000 G in HD 77581 and +1500 G in theta super 2 Ori. Various polarimetric data are also given, including evidence for a variable linear polarization in HD 77581.

  1. Human lambda light-chain constant region gene CMor lambda: the primary structure of lambda VI Bence Jones protein Mor.

    PubMed Central

    Frangione, B; Moloshok, T; Prelli, F; Solomon, A

    1985-01-01

    Serologic, structural, and genetic analyses have shown that the constant (C) region of human kappa light chains is encoded by a single gene, whereas that of lambda chains is encoded by multiple genes. We have determined the complete C region amino acid sequence of two monoclonal lambda VI light chains, Bence Jones proteins Sut and Mor. The C region of lambda chains Sut and Mor consists of 105 residues, as is characteristic for human lambda light chains, of which 102 are identical in sequence. Protein Sut has the C region sequence associated with the C lambda isotype Mcg-, Kern-, Oz+ and represents a product of the C lambda 3 (Kern-, Oz+) gene. Protein Mor has a C region sequence associated with Mcg-, Kern-, and Oz- proteins but differs from protein Sut by the presence of three amino acid interchanges at positions 168, 176, and 194. These substitutions distinguish protein Mor from lambda chains encoded by the C lambda 1 (Mcg+), C lambda 2 (Kern-, Oz-), and C lambda 3 (Kern-, Oz+) genes and provide further evidence for polymorphism of the human C lambda genome. The gene encoding the C region sequence of lambda chain Mor is designated CMor lambda. PMID:3923477

  2. Isolation and characterization of lambda pleu bacteriophages.

    PubMed

    Davis, M G; Calvo, J M

    1977-02-01

    In the Escherichia coli lysogen HfrH73 described by Shimada et al. (1973), none of the enzymes coded for by the leucine operon is synthesized due to an insertion of phage lambda into cistron leuA. The orientation of lambda in the chromosome is ara leuDCB lambda JAN leuA. After heat induction of the lysogen, plaque-forming transducing phages of two types are formed at low frequency. One type (e.g., lambda pleu9) transduces leuD, leuC, and leuB strains to prototrophy. The other type (e.g., lambda pleu 13) transduces leuA strains to prototrophy. lambda pleu 13 forms lysogens at low frequency (about 0.2%) by integration into the leucine operon. These lysogens are unstable, segregating phage-sensitive clones at high frequency (about 1%). Phages carrying different portions of the leucine operon were formed by aberrant excision after heat induction of strain CV437 (leuA371 lambda pleu13). A phage carrying the entire leucine operon (lambda K2) was constructed by a cross between lambda pleu9 and lambda pleu13. An analysis of leucine-forming enzyme levels in strains lysogenized with lambdaK2 indicated that leuO and leuP are present and functional in lambda K2. leu-specific messenger ribonucleic acid from E. coli hybridizes to the heavy (r) strand of lambdaK2. The leucine operon of lambda G4 pleuABCD (an S7 derivative of lambda K2) exists intact on a 7.3 x 10(6)-dalton fragment (lambdaG4EcoRI-B) generated by cleavage with endonuclease EcoRI. Heteroduplexes formed between lambda G4 and lambda show a 5.4 x 10(6)-dalton piece of bacterial deoxyribonucleic acid (DNA) replacing a 4.5 x 10(6)-dalton piece of lambda DNA starting at 0.46 fractional unit on the map of lambda. Fragment lambda G4EcoRI-B has about 0.6 x 10(6) daltons of lambda DNA from the b2 region at one end and about 1.4 x 10(6) daltons of lambda DNA from the int region at the other end.

  3. AN ANALYSIS OF THE ENVIRONMENTS OF FU ORIONIS OBJECTS WITH HERSCHEL

    SciTech Connect

    Green, Joel D.; Evans, Neal J. II; Merello, Manuel; Kospal, Agnes; Herczeg, Gregory; Quanz, Sascha P.; Henning, Thomas; Bouwman, Jeroen; Van Kempen, Tim A.; Lee, Jeong-Eun; Dunham, Michael M.; Meeus, Gwendolyn; Chen, Jo-hsin; Guedel, Manuel; Liebhart, Armin; Skinner, Stephen L.

    2013-08-01

    We present Herschel-HIFI, SPIRE, and PACS 50-670 {mu}m imaging and spectroscopy of six FU Orionis-type objects and candidates (FU Orionis, V1735 Cyg, V1515 Cyg, V1057 Cyg, V1331 Cyg, and HBC 722), ranging in outburst date from 1936 to 2010, from the 'FOOSH' (FU Orionis Objects Surveyed with Herschel) program, as well as ancillary results from Spitzer Infrared Spectrograph and the Caltech Submillimeter Observatory. In their system properties (L{sub bol}, T{sub bol}, and line emission), we find that FUors are in a variety of evolutionary states. Additionally, some FUors have features of both Class I and II sources: warm continuum consistent with Class II sources, but rotational line emission typical of Class I, far higher than Class II sources of similar mass/luminosity. Combining several classification techniques, we find an evolutionary sequence consistent with previous mid-IR indicators. We detect [O I] in every source at luminosities consistent with Class 0/I protostars, much greater than in Class II disks. We detect transitions of {sup 13}CO (J{sub up} of 5-8) around two sources (V1735 Cyg and HBC 722) but attribute them to nearby protostars. Of the remaining sources, three (FU Ori, V1515 Cyg, and V1331 Cyg) exhibit only low-lying CO, but one (V1057 Cyg) shows CO up to J = 23 {yields} 22 and evidence for H{sub 2}O and OH emission, at strengths typical of protostars rather than T Tauri stars. Rotational temperatures for 'cool' CO components range from 20 to 81 K, for {approx} 10{sup 50} total CO molecules. We detect [C I] and [N II] primarily as diffuse emission.

  4. An Analysis of the Environments of FU Orionis Objects with Herschel

    NASA Astrophysics Data System (ADS)

    Green, Joel D.; Evans, Neal J., II; Kóspál, Ágnes; Herczeg, Gregory; Quanz, Sascha P.; Henning, Thomas; van Kempen, Tim A.; Lee, Jeong-Eun; Dunham, Michael M.; Meeus, Gwendolyn; Bouwman, Jeroen; Chen, Jo-hsin; Güdel, Manuel; Skinner, Stephen L.; Liebhart, Armin; Merello, Manuel

    2013-08-01

    We present Herschel-HIFI, SPIRE, and PACS 50-670 μm imaging and spectroscopy of six FU Orionis-type objects and candidates (FU Orionis, V1735 Cyg, V1515 Cyg, V1057 Cyg, V1331 Cyg, and HBC 722), ranging in outburst date from 1936 to 2010, from the "FOOSH" (FU Orionis Objects Surveyed with Herschel) program, as well as ancillary results from Spitzer Infrared Spectrograph and the Caltech Submillimeter Observatory. In their system properties (L bol, T bol, and line emission), we find that FUors are in a variety of evolutionary states. Additionally, some FUors have features of both Class I and II sources: warm continuum consistent with Class II sources, but rotational line emission typical of Class I, far higher than Class II sources of similar mass/luminosity. Combining several classification techniques, we find an evolutionary sequence consistent with previous mid-IR indicators. We detect [O I] in every source at luminosities consistent with Class 0/I protostars, much greater than in Class II disks. We detect transitions of 13CO (J up of 5-8) around two sources (V1735 Cyg and HBC 722) but attribute them to nearby protostars. Of the remaining sources, three (FU Ori, V1515 Cyg, and V1331 Cyg) exhibit only low-lying CO, but one (V1057 Cyg) shows CO up to J = 23 → 22 and evidence for H2O and OH emission, at strengths typical of protostars rather than T Tauri stars. Rotational temperatures for "cool" CO components range from 20 to 81 K, for ~ 1050 total CO molecules. We detect [C I] and [N II] primarily as diffuse emission. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  5. {lambda}NN Three-Body Force due to Coherent {lambda}-{sigma} Coupling

    SciTech Connect

    Akaishi, Yoshinori; Myint, Khin Swe

    2008-04-29

    The overbinding problem of {sub {lambda}}{sup 5}He is solved by introducing a concept of coherent {lambda}-{sigma} coupling which is equivalent to a {lambda}NN three-body force. This three-body force is coherently enhanced in the 0{sup +} states of {sub {lambda}}{sup 4}H and {sub {lambda}}{sup 4}He. The 0{sup +}-1{sup +} splitting in these hypernuclei is mainly due to coherent {lambda}-{sigma} coupling and partly due to the {lambda}N spin-spin interaction. A {lambda}NN three-body potential is derived from the coupled-channel treatment. The origin of the repulsive and attractive nature of the three-body force is discussed. Coherent {lambda}-{sigma} coupling becomes more important in neutron-rich hypernuclei and especially in neutron-star matter at high densities. The possible existence of ''hyperheavy hydrogen'', {sub {lambda}}{sup 6}H, is suggested.

  6. Photoproduction of the Lambda*(1520) Hyperon

    SciTech Connect

    Z. W. Zhao, H. Y. Lu, L. Graham, K. Park, R. W. Gothe

    2010-08-01

    The photoproduction of the Lambda*(1520) on both the proton and neutron have been studied by using the CLAS eg3 run data set. The reactions are gammad-->K+Lambda*(n) and gammad-->K0Lambda*(p) with Lambda*-->pK-. Preliminary total and differential cross sections have been extracted in the photon energy region 1.75 GeVLambda*(1520) on the neutron is reported, and we will extend the results on the proton to higher energies than in previous studies.

  7. On the Periodic X-Ray Emission from the O7 V Star theta 1 Orionis C

    NASA Astrophysics Data System (ADS)

    Babel, Jacques; Montmerle, Thierry

    1997-08-01

    The O7 V star θ1 Orionis C was very recently found to present a strong periodic variation of the X-ray emission (Gagné et al. 1997) that is in agreement with the period determined from the variability of spectral lines (Stahl et al. 1996). The authors suggested that the variations are caused by an oblique magnetic rotator with a large-scale magnetic field modulating the wind. We present here the hypothesis of a dipolar magnetic field embedded in the radiation-driven wind of θ1 Orionis C and analyze the X-ray data in the framework of the magnetically confined wind shock (MCWS) model (Babel & Montmerle 1997). We find that both the ROSAT HRI count rate and the periodic variability of θ1 Orionis C are quantitatively reproduced by the model, provided that the field has an intensity at the stellar surface of B* ~= 300 G. The variability is caused in large part by the circumstellar cooling disk predicted by the MCWS model. These results give strong support to a magnetic origin for the variability of θ1 Orionis C and render this star the best candidate for a high-mass analog to magnetic Bp stars.

  8. Measurement of the Lambda(b) lifetime in the exclusive decay Lambda(b) ---> J / psi Lambda

    SciTech Connect

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao Paulo, IFT /Alberta U. /Simon Fraser U. /York U., Canada /McGill U. /Hefei, CUST /Andes U., Bogota /Charles U.

    2007-04-01

    We have measured the {lambda}{sub b} lifetime using the exclusive decay {lambda}{sub b}{yields}J/{psi}{lambda}, based on 1.2 fb{sup -1} of data collected with the D0 detector during 2002-2006. From 171 reconstructed {lambda}{sub b} decays, where the J/{psi} and {lambda} are identified via the decays J/{psi}{yields}{mu}{sup +}{mu}{sup -} and {lambda}{yields}p{pi}, we measured the {lambda}{sub b} lifetime to be {tau}({lambda}{sub b})=1.218{sub -0.115}{sup +0.130}(stat){+-}0.042(syst) ps. We also measured the B{sup 0} lifetime in the decay B{sup 0}{yields}J/{psi}({mu}{sup +}{mu}{sup -})K{sub S}{sup 0}({pi}{sup +}{pi}{sup -}) to be {tau}(B{sup 0})=1.501{sub -0.074}{sup +0.078}(stat){+-}0.050(syst) ps, yielding a lifetime ratio of {tau}({lambda}{sub b})/{tau}(B{sup 0})=0.811{sub -0.087}{sup +0.096}(stat){+-}0.034(syst = )

  9. Variational Monte Carlo calculations for the binding energy of sub. Lambda. Lambda. sup 31 Si

    SciTech Connect

    Ahsan, M.H. ); Kaykobad, M. ); Ali, S. )

    1991-01-01

    The binding energy of the {Lambda}{Lambda} hypernucleus {sub {Lambda}{Lambda}}{sup 31}Si has been calculated variationally with a {sup 28}Si+{ital n}+{Lambda}+{Lambda} four-body model. The integrations have been carried out with the help of a Monte Carlo technique. Three different types of {Lambda}-{Lambda} and {Lambda}-{ital N} potentials have been used. {ital n}-{sup 28}Si and {Lambda}-{sup 28}Si potentials have been generated by folding the {ital N}-{ital N} and {Lambda}-{ital N} potentials into the harmonic-oscillator shell-model density distribution of {sup 28}Si. The calculated values of the binding energy for the three different potentials are 40.19, 46.30, and 39.90 MeV. These values are compared with the reported experimental value of 38.2{plus minus}6.3 MeV. The dependence of the binding energy on the depth of the {Lambda}-{Lambda} interaction has also been investigated.

  10. VizieR Online Data Catalog: Interferometry and spectroscopy of sigma Orionis (Schaefer+, 2016)

    NASA Astrophysics Data System (ADS)

    Schaefer, G. H.; Hummel, C. A.; Gies, D. R.; Zavala, R. T.; Monnier, J. D.; Walter, F. M.; Turner, N. H.; Baron, F.; Ten Brummelaar, T.; Che, X.; Farrington, C. D.; Kraus, S.; Sturmann, J.; Sturmann, L.

    2017-03-01

    Interferometric data on the σ Orionis triple system were collected between 2010 and 2013 at the CHARA Array located on Mount Wilson, California. The array has six 1m telescopes arranged in a Y configuration with baselines ranging from 34 to 331m. here are two telescopes in each arm, labeled as E (East), W (West), and S (South). We used the Michigan Infrared Combiner (MIRC) to combine the light from three to six telescopes simultaneously. All data were collected after the photometric channels were installed in MIRC; the photometric channels measure the amount of light received from each telescope during the observations to improve the calibration. We used the low spectral resolution prism (R~42) to disperse the fringes across eight spectral channels in the H band (λ=1.5-1.8μm). Navy Prototype Optical Interferometer (NPOI) observations of σ Orionis were collected over a period from 2000 to 2013. Initially, the observations were obtained with the 3-beam combiner, and then, starting in 2002, with the 6-beam hybrid combiner. The NPOI beam combiners disperse the light and record the visibility spectra from 550 to 850 nm in 16 spectral channels. In total, some 59 nights of observations were executed, of which 26 nights were of good quality. The calibrators were selected from a list of single stars maintained at NPOI with diameters estimated from V and (V-K) using the surface brightness relation published by Mozurkewich et al. 2003AJ....126.2502M and van Belle et al. 2009MNRAS.394.1925V. The information for all of the calibrators is given in Table5. We obtained new spectroscopic radial velocity measurements of σ Orionis Aa,Ab using the 1.5m telescope at Cerro Tololo Inter-American Observatory (CTIO). We obtained 40 observations on 29 nights using the Fiber Echelle (FE) Spectrograph (http://www.ctio.noao.edu/~atokovin/echelle/FECH-overview.html) (R=25000, λ=4800-7000Å) between UT 2008 September 23 and 2009 February 21. Additional observations were obtained using the

  11. Measurement of the forward-backward asymmetry of $\\Lambda$ and $\\bar{\\Lambda}$ production in $p \\bar{p}$ collisions

    SciTech Connect

    Abazov, Victor Mukhamedovich

    2016-02-09

    Here, we study $\\Lambda$ and $\\bar{\\Lambda}$ production asymmetries in $p \\bar{p} \\rightarrow \\Lambda (\\bar{\\Lambda}) X$, $p \\bar{p} \\rightarrow J/\\psi \\Lambda (\\bar{\\Lambda}) X$, and $p \\bar{p} \\rightarrow \\mu^\\pm \\Lambda (\\bar{\\Lambda}) X$ events recorded by the D0 detector at the Fermilab Tevatron collider at $\\sqrt{s} = 1.96$ TeV. We find an excess of $\\Lambda$'s ($\\bar{\\Lambda}$'s) produced in the proton (antiproton) direction. This forward-backward asymmetry is measured as a function of rapidity. We confirm that the $\\bar{\\Lambda}/\\Lambda$ production ratio, measured by several experiments with various targets and a wide range of energies, is a universal function of "rapidity loss", i.e., the rapidity difference of the beam proton and the lambda.

  12. Measurement of the forward-backward asymmetry of $$\\Lambda$$ and $$\\bar{\\Lambda}$$ production in $$p \\bar{p}$$ collisions

    DOE PAGES

    Abazov, Victor Mukhamedovich

    2016-02-09

    Here, we studymore » $$\\Lambda$$ and $$\\bar{\\Lambda}$$ production asymmetries in $$p \\bar{p} \\rightarrow \\Lambda (\\bar{\\Lambda}) X$$, $$p \\bar{p} \\rightarrow J/\\psi \\Lambda (\\bar{\\Lambda}) X$$, and $$p \\bar{p} \\rightarrow \\mu^\\pm \\Lambda (\\bar{\\Lambda}) X$$ events recorded by the D0 detector at the Fermilab Tevatron collider at $$\\sqrt{s} = 1.96$$ TeV. We find an excess of $$\\Lambda$$'s ($$\\bar{\\Lambda}$$'s) produced in the proton (antiproton) direction. This forward-backward asymmetry is measured as a function of rapidity. We confirm that the $$\\bar{\\Lambda}/\\Lambda$$ production ratio, measured by several experiments with various targets and a wide range of energies, is a universal function of "rapidity loss", i.e., the rapidity difference of the beam proton and the lambda.« less

  13. Study of Lambda+(c) Cabibbo favored decays containing a Lambda baryon in the final state

    SciTech Connect

    Link, J.M.; Yager, P.M.; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; Agostino, L.; Cinquini, L.; Cumalat, J.P.; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN, Pavia /Rio de Janeiro, Pont. U. Catol. /Puerto Rico U., Mayaguez /South Carolina U. /Tennessee U. /Vanderbilt U. /Wisconsin U., Madison

    2005-05-01

    Using data from the FOCUS experiment (FNAL-E831), they study the decay of {Lambda}{sub c}{sup +} baryons into final states contain a {Lambda} hyperon. The branching fractions of {Lambda}{sub c}{sup +} into {Lambda}{pi}{sup +}, {Lambda}{pi}{sup +}{pi}{sup +}{pi}{sup -} and {Lambda}{bar K}{sup 0}K{sup +} relative to that into pK{sup -} {pi}{sup +} are measured to be 0.217 {+-} 0.013 {+-} 0.020, 0.508 {+-} 0.024 {+-} 0.024 and 0.142 {+-} 0.018 {+-} 0.022, respectively. New measurements are also reported. Further, an analysis of the subresonant structure for the {Lambda}{sub c}{sup +} {yields} {Lambda}{pi}{sup +}{pi}{sup +}{pi}{sup -} decay mode is presented.

  14. Mass loss from pre-main-sequence accretion disks. I - The accelerating wind of FU Orionis

    NASA Technical Reports Server (NTRS)

    Calvet, Nuria; Hartmann, Lee; Kenyon, Scott J.

    1993-01-01

    We present evidence that the wind of the pre-main-sequence object FU Orionis arises from the surface of the luminous accretion disk. A disk wind model calculated assuming radiative equilibrium explains the differential behavior of the observed asymmetric absorption-line profiles. The model predicts that strong lines should be asymmetric and blueshifted, while weak lines should be symmetric and double-peaked due to disk rotation, in agreement with observations. We propose that many blueshifted 'shell' absorption features are not produced in a true shell of material, but rather form in a differentially expanding wind that is rapidly rotating. The inference of rapid rotation supports the proposal that pre-main-sequence disk winds are rotationally driven.

  15. Cold CO Gas in the Envelopes of FU Orionis-type Young Eruptive Stars

    NASA Astrophysics Data System (ADS)

    Kóspál, Á.; Ábrahám, P.; Csengeri, T.; Henning, Th.; Moór, A.; Güsten, R.

    2017-02-01

    FU Orionis-type objects (FUors) are young stellar objects experiencing large optical outbursts due to highly enhanced accretion from the circumstellar disk onto the star. FUors are often surrounded by massive envelopes, which play a significant role in the outburst mechanism. Conversely, the subsequent eruptions might gradually clear up the obscuring envelope material and drive the protostar on its way to become a disk-only T Tauri star. Here we present an APEX 12CO and 13CO survey of eight southern and equatorial FUors. We measure the mass of the gaseous material surrounding our targets, locate the source of the CO emission, and derive physical parameters for the envelopes and outflows, where detected. Our results support the evolutionary scenario where FUors represent a transition phase from envelope-surrounded protostars to classical T Tauri stars.

  16. High Speed Optical Photometry of V1055 Orionis (=4U 0614+091)

    NASA Astrophysics Data System (ADS)

    Lopez, Isaac; Mason, P. A.; Robinson, E. L.

    2013-01-01

    V1055 Orionis (=4U 0614+091) is thought to be an ultra-compact binary containing a neutron star primary with a white dwarf companion. High-speed (10s) broad-band optical observations using the McDonald Observatory, 2.1m, Otto Struve Telescope were obtained on 13 nights in 2010, 2011, and 2012. The nightly mean brightness remained quite stable over the dataset. The light curve is dominated by complex oscillatory behavior reminiscent of the beating of hidden frequencies. A variety of photometric periods have been previously reported and none are found to be coherent periods in our dataset. Rather, a given night exhibits short lived quasi-periodic variations covering a variety of timescales, especially 10-40 min and even as long as two hours. This short period variability combined with recent spectroscopic abundance studies suggests that the likely donor in this binary is a white dwarf.

  17. Recent developments in Lambda networking

    NASA Astrophysics Data System (ADS)

    de Laat, C.; Grosso, P.

    About 6 years ago the first baby-steps were made on opening up dark fiber and DWDM infrastructure for direct use by ISP's after the transformation of the old style Telecom sector into a market driven business. Since then Lambda workshops, community groups like GLIF and a number of experiments have led to many implementations of hybrid national research and education networks and lightpath-based circuit exchanges as pioneered by SURFnet in GigaPort and NetherLight in collaboration with StarLight in Chicago and Canarie in Canada. This article looks back on those developments, describes some current open issues and research developments and proposes a concept of terabit networking.

  18. Chebyshev acceleration for lambda mode calculations

    SciTech Connect

    Belchior, A. Jr.; Moreira, J.M.L. )

    1992-01-01

    Coordenadoria para Projetos Especals (COPESP) has been making an effort to develop a power distribution mapping system utilizing self-powered neutron detectors. The scheme adopted to estimate the power distribution is based on an expansion of lambda modes for a given reactor state. Two-dimensional lambda modes were obtained previously with a modified version of the CITATION code. The method was based on the orthogonality properties of the lambda modes. Several modes could be obtained, but the convergence was slow because of the lack of an appropriate accelerating scheme in the CITATION code for calculating lambda modes. This work presents the acceleration scheme implemented into the CITATION code to obtain lambda modes.

  19. Bacteriophage lambda: early pioneer and still relevant

    PubMed Central

    Casjens, Sherwood R.; Hendrix, Roger W.

    2015-01-01

    Molecular genetic research on bacteriophage lambda carried out during its golden age from the mid 1950's to mid 1980's was critically important in the attainment of our current understanding of the sophisticated and complex mechanisms by which the expression of genes is controlled, of DNA virus assembly and of the molecular nature of lysogeny. The development of molecular cloning techniques, ironically instigated largely by phage lambda researchers, allowed many phage workers to switch their efforts to other biological systems. Nonetheless, since that time the ongoing study of lambda and its relatives have continued to give important new insights. In this review we give some relevant early history and describe recent developments in understanding the molecular biology of lambda's life cycle. PMID:25742714

  20. {lambda}0 Polarization in Exclusive pp Reactions

    SciTech Connect

    Felix, J.

    2006-09-25

    Among all properties of baryons, the polarization they acquire when created from unpolarized p-nucleus collisions is the most recent discovered one; so far, the origin of this polarization remains unexplained in spite of the experimental evidences accumulated in the past thirty years. Up to these days, {lambda}0 is the most studied baryon for polarization, due to it is very easy to produce {lambda}0's at the energies of the principal high energy physics accelerators of the world. This article is a review of the experimental experience accumulated on the polarization of {lambda}0 in unpolarized exclusive pp collisions as function of xF, PT, and M({lambda}0K+) in the past fifteen years here at the Instituto de Fisica, Universidad de Guanajuato, inside Fermilab e690 and Brookhaven National Laboratory e766 collaborations.

  1. Bacteriophage lambda: Early pioneer and still relevant.

    PubMed

    Casjens, Sherwood R; Hendrix, Roger W

    2015-05-01

    Molecular genetic research on bacteriophage lambda carried out during its golden age from the mid-1950s to mid-1980s was critically important in the attainment of our current understanding of the sophisticated and complex mechanisms by which the expression of genes is controlled, of DNA virus assembly and of the molecular nature of lysogeny. The development of molecular cloning techniques, ironically instigated largely by phage lambda researchers, allowed many phage workers to switch their efforts to other biological systems. Nonetheless, since that time the ongoing study of lambda and its relatives has continued to give important new insights. In this review we give some relevant early history and describe recent developments in understanding the molecular biology of lambda's life cycle.

  2. Calculation of two-dimensional lambda modes

    SciTech Connect

    Belchior, A. Jr. ); Moreira, J.M.L. )

    1991-01-01

    A system for on-line monitoring of power distribution in small reactors (known as MAP) is under development at COPESP-IPEN. Signals of self-powered neutron detectors are input to a program that estimates the power distribution as an expansion of lambda modes. The modal coefficients are obtained from a least-mean-squares technique adequate for real-time analysis. Three-dimensional lambda modes are synthesized out of one- and two-dimensional lambda modes. As a part of this project, a modification of a computer code was carried out in order to obtain the lambda modes. The results of this effort are summarized. The lambda modes are the solutions of the time-independent multigroup neutron diffusion equation, an eigenvalue equation. Normally, the computer codes produce the fundamental mode corresponding to the largest eigenvalue; their respective interpretations are neutron flux distribution and effective multiplication factor. For calculating higher order lambda modes it is usually necessary to eliminate the contribution of the lower modes from the fission source.

  3. Studying the disk of the outbursting new FU Orionis object 2MASSJ0659

    NASA Astrophysics Data System (ADS)

    Eisloeffel, Jochen

    2015-10-01

    A new outbursting young stellar object of the rare FU Orionis type -- 2MASSJ06593158-0405277 -- was discovered in Nov 2014. These objects represent the extreme case of the episodic accretion during the star formation process, with accretion rates rising by factors of 100 to 1000 up to 10^-4 M_sun/yr, leading to a brightening of the source by more than a factor 100 in the optical within several months. With a DDT proposal for FORCAST and FIFI-LS we were able to obtain MIR and FIR photometry of the object in Jan/Feb 2015, while the outburst was still on its rise. This is the first time that MIR and FIR photometry are available for such a source from before the outburst (WISE, AKARI) and during the rising burst. FU Ori objects then typically take decades for a very slow decline from their maximum brightness back to the original state. Therefore we are requesting to repeat our FORCAST and FIFI-LS observations (45 min each) now to derive the spectral energy distribution of the source, while it should be in its maximum state. This constitutes an unprecedented dataset to learn more about where in the circumstellar disk such a burst starts, how it is triggered, and what its implications for planet formation may be.

  4. VV Orionis - A well-behaved early-type eclipsing binary system

    NASA Astrophysics Data System (ADS)

    Chambliss, C. R.

    1984-02-01

    VV Orionis is a detached eclipsing binary system consisting of stars of spectral types B1 V and B4 V with a period of 1.4854 d. There is also a third component whose orbital period about the eclipsing pair is about 120 days. Recently, there have been several new photoelectric and spectroscopic investigations of this system, and the results of these are compared. VV Ori A appears to be of normal size and mass for its spectral class, but VV Ori B seems to be somewhat smaller than would be expected for a normal B4 V star. Linear limb-darkening coefficients are derived for VV Ori A and are in good agreement with theory. This system is of particular importance, because it is only one of very few early-type systems for which reliable limb-darkening coefficients can be expected to be obtained. The contribution of the light of the third component to the system has also been determined, and it appears most likely that VV Ori C is a star of spectral type A3 V.

  5. OT1_jgreen02_2: FOOSH: FU Orionis Objects Surveyed with Herschel

    NASA Astrophysics Data System (ADS)

    Green, J.

    2010-07-01

    We propose to utilize the unprecedented spatial resolution and sensitivity of Herschel at far-infrared and submm wavelengths to observe nearly all known FU Orionis objects, the dramatic result of burst accretion events in protostellar disks. The known FUors represent a vital window into a key process of star formation rather than a rare and peculiar event in the lives of a few stars. In addition, FUors provide a natural laboratory that probes the effect on enhanced heating on disk composition and structure. Our objectives are to (1) Study the structure of known envelopes and constrain the amount of remnant envelope material around the remainder; (2) characterize the physical and chemical properties of the disks and envelope, the parameters that set the initial conditions for planet formation in T Tauri disks; (3) observe solid-state, atomic, and molecular spectral features toward FUors in order to determine the effects of increased luminosity on mineralogy, disk chemistry, and envelope material. In order to do this we will use all three instruments onboard Herschel, providing a comprehensive survey of FUors.

  6. Dust and gas in FU Orionis objects: FORCAST spectroscopy of outbursting young stars

    NASA Astrophysics Data System (ADS)

    Green, Joel

    2013-10-01

    Mid-IR dust features occasionally vary dramatically in T Tauri stars, but are typically consistent over multiple epochs. Most T Tauri silicate features indicate both grain growth and high crystallinity fractions. In contrast, outbursting sources (FUors) exhibit some grain growth but pristine silicate emission features. We propose to observe four classical FU Orionis objects (FU Ori, V1057 Cyg, V1515 Cyg, V1735 Cyg) in order to determine whether the outburst influences the dust feature or instead highlights a larger dust radius where processing has not yet occurred. These sources were all observed with Spitzer-IRS in 2005-6, and have declined in overall brightness at different rates, providing several different case studies. Their bright continuum (1-6 Jy) over the 5-40 um range provides the perfect opportunity to observe them with FORCAST spectroscopy, with a 7 year baseline to probe changes in their mid-IR properties. This will be the first mid-IR variability study of FUors.

  7. CONSTRAINING MASS RATIO AND EXTINCTION IN THE FU ORIONIS BINARY SYSTEM WITH INFRARED INTEGRAL FIELD SPECTROSCOPY

    SciTech Connect

    Pueyo, Laurent; Hillenbrand, Lynne; Hinkley, Sasha; Dekany, Richard; Roberts, Jenny; Vasisht, Gautam; Roberts, Lewis C. Jr.; Shao, Mike; Burruss, Rick; Cady, Eric; Oppenheimer, Ben R.; Brenner, Douglas; Zimmerman, Neil; Monnier, John D.; Crepp, Justin; Parry, Ian; Beichman, Charles; Soummer, Remi

    2012-09-20

    We report low-resolution near-infrared spectroscopic observations of the eruptive star FU Orionis using the Integral Field Spectrograph (IFS) Project 1640 installed at the Palomar Hale telescope. This work focuses on elucidating the nature of the faint source, located 0.''5 south of FU Ori, and identified in 2003 as FU Ori S. We first use our observations in conjunction with published data to demonstrate that the two stars are indeed physically associated and form a true binary pair. We then proceed to extract J- and H-band spectro-photometry using the damped LOCI algorithm, a reduction method tailored for high contrast science with IFS. This is the first communication reporting the high accuracy of this technique, pioneered by the Project 1640 team, on a faint astronomical source. We use our low-resolution near-infrared spectrum in conjunction with 10.2 {mu}m interferometric data to constrain the infrared excess of FU Ori S. We then focus on estimating the bulk physical properties of FU Ori S. Our models lead to estimates of an object heavily reddened, A{sub V} = 8-12, with an effective temperature of {approx}4000-6500 K. Finally, we put these results in the context of the FU Ori N-S system and argue that our analysis provides evidence that FU Ori S might be the more massive component of this binary system.

  8. FU Orionis outbursts, preferential recondensation of water ice, and the formation of giant planets

    NASA Astrophysics Data System (ADS)

    Hubbard, Alexander

    2017-02-01

    Ices, including water ice, prefer to recondense on to preexisting nuclei rather than spontaneously forming grains from a cloud of vapour. Interestingly, different potential recondensation nuclei have very different propensities to actually nucleate water ice at the temperatures associated with freeze-out in protoplanetary discs. Therefore, if a region in a disc is warmed and then recooled, water vapour should not be expected to refreeze evenly on to all available grains. Instead, it will preferentially recondense on to the most favorable grains. When the recooling is slow enough, only the most favorable grains will nucleate ice, allowing them to recondense thick ice mantles. We quantify the conditions for preferential recondensation to rapidly create pebble-sized grains in protoplanetary discs and show that FU Orionis type outbursts have the appropriate cooling rates to drive pebble creation in a band about 5 au wide outside of the quiescent frost line from approximately Jupiter's orbit to Saturn's (about -10 au). Those pebbles could be of the appropriate size to proceed to planetesimal formation via the Streaming Instability, or to contribute to the growth of planetesimals through pebble accretion. We suggest that this phenomenon contributed to the formation of the gas giants in our own Solar system.

  9. A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. IV. A Multiwavelength, Non-LTE Spectroscopic Analysis

    NASA Astrophysics Data System (ADS)

    Shenar, T.; Oskinova, L.; Hamann, W.-R.; Corcoran, M. F.; Moffat, A. F. J.; Pablo, H.; Richardson, N. D.; Waldron, W. L.; Huenemoerder, D. P.; Maíz Apellániz, J.; Nichols, J. S.; Todt, H.; Nazé, Y.; Hoffman, J. L.; Pollock, A. M. T.; Negueruela, I.

    2015-08-01

    Eclipsing systems of massive stars allow one to explore the properties of their components in great detail. We perform a multi-wavelength, non-LTE analysis of the three components of the massive multiple system δ Ori A, focusing on the fundamental stellar properties, stellar winds, and X-ray characteristics of the system. The primary’s distance-independent parameters turn out to be characteristic for its spectral type (O9.5 II), but usage of the Hipparcos parallax yields surprisingly low values for the mass, radius, and luminosity. Consistent values follow only if δ Ori lies at about twice the Hipparcos distance, in the vicinity of the σ-Orionis cluster. The primary and tertiary dominate the spectrum and leave the secondary only marginally detectable. We estimate the V-band magnitude difference between primary and secondary to be {{Δ }}V≈ 2\\buildrel{{m}}\\over{.} 8. The inferred parameters suggest that the secondary is an early B-type dwarf (≈B1 V), while the tertiary is an early B-type subgiant (≈B0 IV). We find evidence for rapid turbulent velocities (˜200 km s-1) and wind inhomogeneities, partially optically thick, in the primary’s wind. The bulk of the X-ray emission likely emerges from the primary’s stellar wind ({log}{L}{{X}}/{L}{Bol}≈ -6.85), initiating close to the stellar surface at {R}0˜ 1.1 {R}*. Accounting for clumping, the mass-loss rate of the primary is found to be {log}\\dot{M}≈ -6.4 ({M}⊙ {{yr}}-1), which agrees with hydrodynamic predictions, and provides a consistent picture along the X-ray, UV, optical, and radio spectral domains.

  10. Preparation and assay of phage lambda.

    PubMed

    Dale, J W; Greenaway, P J

    1985-01-01

    Lambda, a temperate bacteriophage of E. coli, has two alternative modes of replication in sensitive cells, known as the lytic and lysogenic cycles. In the lytic cycle, after the lambda DNA enters the cells, various phage functions are expressed that result in the production of a large number of mature phage particles and cell lysis. In the lysogenic mode, which normally occurs in only a small proportion of the infected cells, the phage forms a more or less stable relationship with the host bacterium; this stable state is known as lysogeny. In a lysogenic cell, phage DNA is normally incorporated into the chromosomal DNA via specific attachment sites on both the phage DNA and the host chromosome. Replication of lambda DNA then occurs only during replication of the host chromosome, and the phage genome is inherited by each daughter cell at cell division. The phage is maintained in this prophage state through the action of a repressor protein, coded for by the phage gene cl. This repressor protein turns off the expression of virtually the whole of the lambda genome. If the repressor is inactivated, the expression of phage genes is initiated. This leads to the excision of lambda DNA from the host chromosome and entry into the lytic cycle. The balance between the lytic and lysogenic modes of replication is a delicate and complex one in which a key factor is the concentration of the cl gene product. Some of the many sources of further information about the basic biology of lambda phage are listed in the references to this chapter.

  11. Lambda Exonuclease Digestion of CGG Trinucleotide Repeats

    PubMed Central

    Conroy, R.S.; Koretsky, A.P.; Moreland, J.

    2011-01-01

    Fragile X syndrome and other triplet repeat diseases are characterized by an elongation of a repeating DNA triplet. The ensemble-averaged lambda exonuclease digestion rate of different substrates, including one with an elongated FMR1 gene containing 120 CGG repeats, was measured using absorption and fluorescence spectroscopy. Using magnetic tweezers sequence-dependent digestion rates and pausing was measured for individual lambda exonucleases. Within the triplet repeats a lower average and narrower distribution of rates and a higher frequency of pausing was observed. PMID:19562332

  12. CHANDRA REVEALS VARIABLE MULTI-COMPONENT X-RAY EMISSION FROM FU ORIONIS

    SciTech Connect

    Skinner, Stephen L.; Guedel, Manuel; Briggs, Kevin R.; Lamzin, Sergei A.

    2010-10-20

    FU Orionis is the prototype of a class of eruptive young stars ('FUors') characterized by strong optical outbursts. We recently completed an exploratory survey of FUors using XMM-Newton to determine their X-ray properties, about which little was previously known. The prototype FU Ori and V1735 Cyg were detected. The X-ray spectrum of FU Ori was found to be unusual, consisting of a cool moderately absorbed component plus a hotter component viewed through an absorption column density that is an order of magnitude higher. We present here a sensitive (99 ks) follow-up X-ray observation of FU Ori obtained at higher angular resolution with Chandra ACIS-S. The unusual multi-component spectrum is confirmed. The hot component is centered on FU Ori and dominates the emission above 2 keV. It is variable (a signature of magnetic activity) and is probably coronal emission originating close to FU Ori's surface viewed through cool gas in FU Ori's strong wind or accretion stream. In contrast, the X-ray centroid of the soft emission below 2 keV is offset 0.''20 to the southeast of FU Ori, toward the near-IR companion (FU Ori S). This offset amounts to slightly less than half the separation between the two stars. The most likely explanation for the offset is that the companion contributes significantly to the softer X-ray emission below 2 keV (and weakly above 2 keV). The superimposed X-ray contributions from FU Ori and the companion resolve the paradox posed by XMM-Newton of an apparently single X-ray source viewed through two different absorption columns.

  13. ELLIPSOIDAL VARIABLE V1197 ORIONIS: ABSOLUTE LIGHT-VELOCITY ANALYSIS FOR KNOWN DISTANCE

    SciTech Connect

    Wilson, R. E.; Chochol, D.; KomzIk, R.; Van Hamme, W.; Pribulla, T.; Volkov, I.

    2009-09-01

    V1197 Orionis light curves from a long-term observing program for red giant binaries show ellipsoidal variation of small amplitude in the V and R{sub C} bands, although not clearly in U and B. Eclipses are not detected. All four bands show large irregular intrinsic variations, including fleeting quasi-periodicities identified by power spectra, that degrade analysis and may be caused by dynamical tides generated by orbital eccentricity. To deal with the absence of eclipses and consequent lack of astrophysical and geometrical information, direct use is made of the Hipparcos parallax distance while the V and R{sub C} light curves and (older) radial velocity curves are analyzed simultaneously in terms of absolute flux. The red giant's temperature is estimated from new spectra. This type of analysis, called Inverse Distance Estimation for brevity, is new and can also be applied to other ellipsoidal variables. Advantages gained by utilization of definite distance and temperature are discussed in regard to how radius, fractional lobe filling, and mass ratio information are expressed in the observations. The advantages were tested in solutions of noisy synthetic data. Also discussed and tested by simulations are ideas on the optimal number of light curves to be solved simultaneously under various conditions. The dim companion has not been observed or discussed in the literature but most solutions find its mass to be well below that of the red giant. Solutions show red giant masses that are too low for evolution to the red giant stage within the age of the Galaxy, although that result is probably an artifact of the intrinsic brightness fluctuations.

  14. Long-term evolution of FU Orionis objects at infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Ábrahám, P.; Kóspál, Á.; Csizmadia, Sz.; Kun, M.; Moór, A.; Prusti, T.

    2004-12-01

    We investigate the brightness evolution of seven FU Orionis systems in the 1-100 μm wavelength range using data from the Infrared Space Observatory (ISO). The ISO measurements were supplemented by 2MASS and MSX observations performed in the same years as the ISO mission (1995-98). The spectral energy distributions (SEDs) based on these data points were compared with earlier ones derived from the IRAS photometry as well as from ground-based observations carried out around the epoch 1983. In three cases (Z CMa, Parsamian 21, V1331 Cyg) no difference between the two epochs was seen within the measurement uncertainties. V1057 Cyg, V1515 Cyg and V1735 Cyg have become fainter at near-infrared wavelengths while V346 Nor has become slightly brighter. V1057 Cyg exhibits a similar flux change in the mid-infrared. At λ≥ 60 μm most of the sources remained constant; only V346 Nor seems to fade. Our data on the long-term evolution of V1057 Cyg agree with the model predictions of Kenyon & Hartmann (\\cite{Kenyonh91}) and Turner et al. (\\cite{Turner97}) at near- and mid-infrared wavelengths, but disagree at λ>25 μm. We discuss if this observational result at far-infrared wavelengths could be understood in the framework of the existing models. Based on observations with ISO, an ESA project with instruments funded by ESA member states (especially the PI countries France, Germany, the Netherlands and the United Kingdom) with participation of ISAS and NASA.

  15. Catching the next bright outbursting FU Orionis object on the rise

    NASA Astrophysics Data System (ADS)

    Eisloeffel, Jochen

    2015-10-01

    Outbursting young stellar object of the rare FU Orionis type represent the extreme case of the episodic accretion during the star formation process, with accretion rates rising by factors of 100 to 1000 up to 10^-4 M_sun/yr, leading to a brightening of the source by more than a factor 100 in the optical within several months. With a DDT proposal for FORCAST and FIFI-LS we were able to obtain MIR and FIR photometry of the newly discovered outbursting FUor 2MASSJ0659-04 in Jan/Feb 2015, while the outburst was still on its rise. This was the first time that MIR and FIR photometry were available for such a source from before the outburst (WISE, AKARI) and during the rising burst. FU Ori objects then typically take decades for a very slow decline from their maximum brightness back to the original state. With the sensitive infrared sky surveys at hand nowadays it is very likely that also for future bright FUors pre-outburst data will be available, which are allowing us to follow the changes of the circumstellar disk through the burst. Here we are requesting Target-of-Opportunity observations for the next bright outbursting FUor with FORCAST and FIFI-LS observations (1h each) while the outburst is on its rise. With these data we will derive the spectral energy distribution of the source. This constitutes an excellent dataset to learn more about where in the circumstellar disk such a burst starts, how it is triggered, and what its implications for planet formation may be.

  16. Chandra Reveals Variable Multi-component X-ray Emission From FU Orionis

    NASA Astrophysics Data System (ADS)

    Skinner, Stephen L.; Güdel, Manuel; Briggs, Kevin R.; Lamzin, Sergei A.

    2010-10-01

    FU Orionis is the prototype of a class of eruptive young stars ("FUors") characterized by strong optical outbursts. We recently completed an exploratory survey of FUors using XMM-Newton to determine their X-ray properties, about which little was previously known. The prototype FU Ori and V1735 Cyg were detected. The X-ray spectrum of FU Ori was found to be unusual, consisting of a cool moderately absorbed component plus a hotter component viewed through an absorption column density that is an order of magnitude higher. We present here a sensitive (99 ks) follow-up X-ray observation of FU Ori obtained at higher angular resolution with Chandra ACIS-S. The unusual multi-component spectrum is confirmed. The hot component is centered on FU Ori and dominates the emission above 2 keV. It is variable (a signature of magnetic activity) and is probably coronal emission originating close to FU Ori's surface viewed through cool gas in FU Ori's strong wind or accretion stream. In contrast, the X-ray centroid of the soft emission below 2 keV is offset 0farcs20 to the southeast of FU Ori, toward the near-IR companion (FU Ori S). This offset amounts to slightly less than half the separation between the two stars. The most likely explanation for the offset is that the companion contributes significantly to the softer X-ray emission below 2 keV (and weakly above 2 keV). The superimposed X-ray contributions from FU Ori and the companion resolve the paradox posed by XMM-Newton of an apparently single X-ray source viewed through two different absorption columns.

  17. Spectral Energy Distribution Analysis of Class I and Class II FU Orionis Stars

    NASA Astrophysics Data System (ADS)

    Gramajo, Luciana V.; Rodón, Javier A.; Gómez, Mercedes

    2014-06-01

    FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ~80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ~10-7 M ⊙ yr-1 versus ~10-5 M ⊙ yr-1 for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (~70%) have envelope mass accretion rates above 10-7 M ⊙ yr-1. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.

  18. Photometric behaviour of the FU Orionis type star, V1057 Cygni, during the last 25 years

    NASA Astrophysics Data System (ADS)

    Kopatskaya, E. N.; Kolotilov, E. A.; Arkharov, A. A.

    2013-09-01

    The FU Orionis type of variable star (FUor), V1057 Cygni, underwent a nova-like outburst in 1969-1970. Among the FUors, V1057 Cyg is notable for having the most dramatic post-maximum decrease in brightness. Thus, photometric monitoring of this object is important for interpretations of the cause of this event. Here, we study the behaviour of V1057 Cyg over the last 25 years on the basis of our optical and infrared observations. The optical and near-infrared observations of V1057 Cyg started in 1974, and we present all our data (up to the end of 2011), including 1085 and 167 nights of optical and infrared photometry, respectively. The UBVRIJHKLM light curves for 1985-2011 show that despite the increased photometric activity, after a rapid decrease in brightness in the mid-1990s, the average level of brightness remained practically constant. After the object becomes fainter than V ≈ 11.5 mag, a swerve appears in the track of the colour-magnitude diagram. The light variability shows a different periodicity in different spectral regions. We have discovered a period of 1631 ± 60 d in the BVR bands (1995-2011) and 523 ± 40 d in the RIJHK bands (2002-2011) with amplitudes of 0.5-0.3 mag. The 523-d period is presumably correlated with the changes in the radial velocity of an emission component in Li I. We conclude that the observed properties of the FUor star V1057 Cyg are in accordance with current models of FUors involving binary or multiple systems.

  19. Ellipsoidal Variable V1197 Orionis: Absolute Light-Velocity Analysis for Known Distance

    NASA Astrophysics Data System (ADS)

    Wilson, R. E.; Chochol, D.; Komžík, R.; Van Hamme, W.; Pribulla, T.; Volkov, I.

    2009-09-01

    V1197 Orionis light curves from a long-term observing program for red giant binaries show ellipsoidal variation of small amplitude in the V and RC bands, although not clearly in U and B. Eclipses are not detected. All four bands show large irregular intrinsic variations, including fleeting quasi-periodicities identified by power spectra, that degrade analysis and may be caused by dynamical tides generated by orbital eccentricity. To deal with the absence of eclipses and consequent lack of astrophysical and geometrical information, direct use is made of the Hipparcos parallax distance while the V and RC light curves and (older) radial velocity curves are analyzed simultaneously in terms of absolute flux. The red giant's temperature is estimated from new spectra. This type of analysis, called Inverse Distance Estimation for brevity, is new and can also be applied to other ellipsoidal variables. Advantages gained by utilization of definite distance and temperature are discussed in regard to how radius, fractional lobe filling, and mass ratio information are expressed in the observations. The advantages were tested in solutions of noisy synthetic data. Also discussed and tested by simulations are ideas on the optimal number of light curves to be solved simultaneously under various conditions. The dim companion has not been observed or discussed in the literature but most solutions find its mass to be well below that of the red giant. Solutions show red giant masses that are too low for evolution to the red giant stage within the age of the Galaxy, although that result is probably an artifact of the intrinsic brightness fluctuations.

  20. The X-ray spectrum of δ Orionis observed by LETGS aboard Chandra

    NASA Astrophysics Data System (ADS)

    Raassen, A. J. J.; Pollock, A. M. T.

    2013-02-01

    Aims: We analyze the high-resolution X-ray spectrum of the supergiant O-star δ Orionis (O9.5II) with line ratios of He-like ions and a thermal plasma model, and we examine its variability. Methods: The O-supergiant δ Ori was observed in the wavelength range 5-175 Å by the X-ray detector HRC-S in combination with the grating LETG aboard Chandra. We studied the He-like ions in combination with the UV-radiation field to determine local plasma temperatures and to establish the distance of the X-ray emitting ions to the stellar surface. We measured individual lines by means of Gaussian profiles, folded through the response matrix, to obtain wavelengths, line fluxes, half widths at half maximum (HWHM) and line shifts to characterize the plasma. We consider multitemperature models in collisional ionization equilibrium (CIE) to determine temperatures, emission measures, and abundances. Results: Analysis of the He-like triplets extended to N vi and C v implies ionization stratification with the hottest plasma to be found within a few stellar radii 3 R∗ (Mg xi) and the coolest farther out, far beyond the acceleration zone, up to 49 R∗ (N vi) and 75 R∗ (C v). The observed temperatures cover a range from about 0.1 to 0.7 keV, i.e., 1-8 MK. The X-ray luminosity (Lx) is ~1.5 × 1032 erg/s in the range from 0.07 to 3 keV covered by LETGS. Velocity widths of about 1040 km s-1 have been determined.

  1. THE CONTINUING OUTBURST OF V1647 ORIONIS: WINTER/SPRING 2011 OBSERVATIONS

    SciTech Connect

    Aspin, Colin

    2011-10-15

    We present optical and near-IR observations of the young eruptive variable star V1647 Orionis which illuminates McNeil's Nebula. In late 2003, V1647 Ori was observed to brighten by around 5 mag to r' = 17.7. In early 2006 the star faded back to its quiescent brightness of r' {approx} 23, however in mid-2008 it brightened yet again by {approx}5 mag. Our new observations, taken in early 2011, show V1647 Ori to be in an elevated photometric state with an optical brightness similar to the value found at the start of the 2003 and 2008 outbursts. Optical images taken between 2008 and 2011 suggest that the star has remained in outburst from mid-2008 to the present. H{alpha} and the far-red Ca II triplet lines remain in emission with H{alpha} possessing a significant P Cygni profile. A self-consistent study of the accretion luminosity and rate using data taken in 2004, 2007, 2008, and 2011 indicates that when bright, V1647 Ori has values of 16 {+-} 2 L{sub sun} and (4 {+-} 2) x 10{sup -6} M{sub sun} yr{sup -1}, respectively. We support the premise that the accretion luminosity and rate both declined by a factor of 2-3 during the 5 mag fading in 2007. However, a significant part of the fading was due to either variable extinction or dust reformation. We discuss these new observations in relation to previous published data and the classification schemes for young eruptive variables.

  2. Hypertriton and light nuclei production at Lambda-production subthreshold energy in heavy-ion collisions

    SciTech Connect

    Zhang, S.; Zu, Z.; Chen, J.H., Ma, Y.G., Cai, X-Z, Ma, G.L., Zhong, C.

    2011-08-01

    High-energy heavy-ion collisions produce abundant hyperons and nucleons. A dynamical coalescence model coupled with the ART model is employed to study the production probabilities of light clusters, deuteron (d), triton (t), helion ({sup 3}He), and hypertriton ({sub {Lambda}}{sup 3}H) at subthreshold energy of Aproduction ({approx} 1 GeV per nucleon). We study the dependence on the reaction system size of the coalescence penalty factor per additional nucleon and entropy per nucleon. The Strangeness Population Factor (S{sub 3} = {sup 3}{sub {Lambda}}H/({sup 3}He x {Lambda}/p)) shows an extra suppression of hypertriton comparing to light clusters of the same mass number. This model predicts a hypertriton production cross-section of a few {mu}b in {sup 36}Ar+{sup 36}Ar, {sup 40}Ca+{sup 40}Ca and {sup 56}Ni+{sup 56}Ni in 1 A GeV reactions. The production rate is as high as a few hypertritons per million collisions, which shows that the fixed-target heavy-ion collisions at CSR (Lanzhou/China) at {Lambda} subthreshold energy are suitable for breaking new ground in hypernuclear physics.

  3. Lambda Station: On-demand flow based routing for data intensive Grid applications over multitopology networks

    SciTech Connect

    Bobyshev, A.; Crawford, M.; DeMar, P.; Grigaliunas, V.; Grigoriev, M.; Moibenko, A.; Petravick, D.; Rechenmacher, R.; Newman, H.; Bunn, J.; Van Lingen, F.; Nae, D.; Ravot, S.; Steenberg, C.; Su, X.; Thomas, M.; Xia, Y.; /Caltech

    2006-08-01

    Lambda Station is an ongoing project of Fermi National Accelerator Laboratory and the California Institute of Technology. The goal of this project is to design, develop and deploy network services for path selection, admission control and flow based forwarding of traffic among data-intensive Grid applications such as are used in High Energy Physics and other communities. Lambda Station deals with the last-mile problem in local area networks, connecting production clusters through a rich array of wide area networks. Selective forwarding of traffic is controlled dynamically at the demand of applications. This paper introduces the motivation of this project, design principles and current status. Integration of Lambda Station client API with the essential Grid middleware such as the dCache/SRM Storage Resource Manager is also described. Finally, the results of applying Lambda Station services to development and production clusters at Fermilab and Caltech over advanced networks such as DOE's UltraScience Net and NSF's UltraLight is covered.

  4. Three-dimensional implicit lambda methods

    NASA Technical Reports Server (NTRS)

    Napolitano, M.; Dadone, A.

    1983-01-01

    This paper derives the three dimensional lambda-formulation equations for a general orthogonal curvilinear coordinate system and provides various block-explicit and block-implicit methods for solving them, numerically. Three model problems, characterized by subsonic, supersonic and transonic flow conditions, are used to assess the reliability and compare the efficiency of the proposed methods.

  5. Very low-luminosity Class I/Flat outflow sources in sigma Orionis: Clues to alternative formation mechanisms for very low-mass stars

    NASA Astrophysics Data System (ADS)

    Riaz, Basmah; Whelan, E.; Thompson, M.; Vorobyov, E.; Lodieu, N.

    2015-01-01

    We present an optical through sub-millimetre multi-wavelength study of two very low-luminosity Class I/Flat systems, Mayrit 1701117 and Mayrit 1082188, in the sigma Orionis cluster. We performed moderate resolution (R 1000) optical ( 0.4-0.9mu) spectroscopy with the TWIN spectrograph at the Calar Alto 3.5-m telescope. The spectra for both sources show prominent emission in accretion- and outflow-associated lines. The mean accretion rate measured from multiple line diagnostics is 6.4x10^{-10} Msun/yr for Mayrit 1701117, and 2.5x10^{-10} Msun/yr for Mayrit 1082188. The outflow mass loss rates for the two systems are similar and estimated to be 1x10^{-9} Msun/yr. The activity rates are within the range observed for low-mass Class I protostars. We obtained sub-millimetre continuum observations with the Submillimetre Common-User Bolometer Array (SCUBA-2) bolometer at the James Clerk Maxwell Telescope. Both objects are detected at a >5-sigma level in the SCUBA-2 850mu band. The bolometric luminosity of the targets as measured from the observed spectral energy distribution over 0.8-850mu is 0.18+/-0.04 Lsun for Mayrit 1701117, and 0.16+/-0.03 Lsun for Mayrit 1082188, and is in the very low-mass range. The total dust+gas mass derived from sub-millimetre fluxes is 36 M_Jup and 22 M_Jup for Mayrit 1701117 and Mayrit 1082188, respectively. There is the possibility that some of the envelope material might be dissipated by the strong outflows driven by these sources, resulting in a final mass of the system close to or below the sub-stellar limit. Given the membership of these objects in a relatively evolved cluster of 3 Myr of age, we consider an alternate formation mechanism in the context of the `hybrid' model of disk fragmentation, followed by ejection of a gaseous clump.

  6. GALAXY CLUSTER BULK FLOWS AND COLLISION VELOCITIES IN QUMOND

    SciTech Connect

    Katz, Harley; McGaugh, Stacy; Teuben, Peter; Angus, G. W. E-mail: stacy.mcgaugh@case.edu E-mail: angus.gz@gmail.com

    2013-07-20

    We examine the formation of clusters of galaxies in numerical simulations of a QUMOND cosmogony with massive sterile neutrinos. Clusters formed in these exploratory simulations develop higher velocities than those found in {Lambda}CDM simulations. The bulk motions of clusters attain {approx}1000 km s{sup -1} by low redshift, comparable to observations whereas {Lambda}CDM simulated clusters tend to fall short. Similarly, high pairwise velocities are common in cluster-cluster collisions like the Bullet Cluster. There is also a propensity for the most massive clusters to be larger in QUMOND and to appear earlier than in {Lambda}CDM, potentially providing an explanation for ''pink elephants'' like El Gordo. However, it is not obvious that the cluster mass function can be recovered.

  7. The Hyperon {Lambda}(1405) in p+p reactions

    SciTech Connect

    Siebenson, Johannes

    2011-10-21

    We present an analysis of the hyperon {Lambda}(1405) for p+p reactions at 3.5 GeV kinetic beam energy. The data were taken with the High Acceptance Di-Electron Spectrometer (HADES). A {Lambda}(1405) signal could be reconstructed in both charged decay channels ({Lambda}(1405){yields}{Sigma}{sup {+-}}{pi}{sup {+-}}).

  8. Measurement of the Branching Fraction and Lambda-bar Polarization in B0 -> Lambda-par p pi-

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2009-08-03

    We present a measurement of the B{sup 0} {yields} {bar {Lambda}}p{pi}{sup -} branching fraction performed using the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} collider. Based on a sample of 467 x 10{sup 6} B{bar B} pairs we measure {Beta}(B{sup 0} {yields} {bar {Lambda}}p{pi}{sup -}) [3.07 {+-} 0.31(stat.) {+-} 0.23(syst.)] x 10{sup -6}. The measured differential spectrum as a function of the dibaryon invariant mass m({bar {Lambda}}p) shows a near-threshold enhancement similar to that observed in other baryonic B decays. We study the {bar {Lambda}} polarization as a function of {bar {Lambda}} energy in the B{sup 0} rest frame (E*{sub {bar {Lambda}}}) and compare it with theoretical expectations of fully longitudinally right-polarized {bar {Lambda}} at large E*{sub {bar {Lambda}}}.

  9. Study of the decay asymmetry parameter and CP violation parameter in the Lambda(c)+ ---> Lambda pi+ decay

    SciTech Connect

    Link, J.M.; Yager, P.M.; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; Agostino, L.; Cinquini, L.; Cumalat, J.P.; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN, Pavia /Rio de Janeiro, Pont. U. Catol. /Puerto Rico U., Mayaguez /South Carolina U. /Tennessee U. /Vanderbilt U. /Wisconsin U., Madison

    2005-09-01

    Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter a{sub {Lambda}{sub c}} in {Lambda}{sub c}{sup +} {yields} {Lambda}{pi}{sup +} decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter {Alpha} {triple_bond} a{sub {Lambda}{sub c}} + a{sub {ovr {Lambda}{sub c}}}/a{sub {Lambda}{sub c}} - a{sub {ovr {Lambda}{sub c}}}. We obtain a{sub {Lambda}{sub c}} = -0.78 {+-} 0.16 {+-} 0.13 and {Alpha} = -0.07 {+-} 0.19 {+-} 0.12 where errors are statistical and systematic.

  10. The Evolution of the FU Orionis Disk, and the Seeds of Planet Formation

    NASA Astrophysics Data System (ADS)

    Green, Joel D.

    2016-10-01

    Young stars form new planetary systems during the collapse of a giant cloud of gas and dust. Tiny dust particles and gas parcels collide and stick together, growing slowly into planetary cores and then full-size planets. But is this process a steady and slow one, or are there bumps in the road to planet construction? In 1936, the young star FU Orionis (FU Ori) became 100 times brighter in only a few short months. Although astronomers didn't realize at the time, FU Ori was undergoing a "burst" of accretion -- instead of a slow trickle of material falling into the central star, nearly 20 Jupiters worth of material have fallen in and burned since 1936. This sustained flow is a large fraction of the entire measureable disk mass (both gas and dust) surrounding FU Ori. FU Ori has slowly faded over the past 80 years, reducing by approximately 1 mag. in B. But what changes did this increased brightness wreak upon FU Ori's disk, and what implications would it have for any planets that might have formed or form later? Unlike most observed young stars, FU Ori and its (~ 10) brethren with similar behavior show no evidence of crystalline dust grains like forsterite (peridot), and the temperatures at an Earth-equivalent distance would have risen from room temperature to a scalding 1000 degrees Kelvin.Our study with SOFIA/FORCAST, in comparison with our previous study with Spitzer/IRS, provides the first multi-epoch infrared spectroscopic study of an FUor, as it appeared in 2004 and 2016. First, the continuum (the energy emitted by viscous heating in the disk) has decreased by 13% but is still fit by a 7200 K blackbody at 13% less strength; second, the heating source behind disk's atmosphere (similar to a stellar atmosphere, as the superheated inner disk is at the same temperature as a typical star) has also decreased, exciting less high temperature water vapor. This change has not completely propagated to the rest of the disk. The silicate dust remains unchanged. We conclude

  11. Are the outflows in FU Orionis systems driven by the stellar magnetic field?

    NASA Astrophysics Data System (ADS)

    Königl, Arieh; Romanova, Marina M.; Lovelace, Richard V. E.

    2011-09-01

    FU Orionis (FUOR) outbursts are major optical brightening episodes in low-mass protostars that evidently correspond to rapid mass accretion events in the innermost region of a protostellar disc. The outbursts are accompanied by strong outflows, with the inferred mass outflow rates reaching ˜10 per cent of the mass inflow rates. Shu et al. proposed that the outflows represent accreted disc material that is driven centrifugally from the spun-up surface layers of the protostar by the stellar magnetic field. This model was critiqued by Calvet et al., who argued that it cannot reproduce the photospheric absorption-line shifts observed in the prototype object FU Ori. Calvet et al. proposed that the wind is launched, instead, from the surface of the disc on scales of a few stellar radii by a non-stellar magnetic field. In this paper we present results from numerical simulations of disc accretion on to a slowly rotating star with an aligned magnetic dipole moment that gives rise to a kilogauss-strength surface field. We demonstrate that, for parameters appropriate to FU Ori, such a system can develop a strong, collimated disc outflow of the type previously identified by Romanova et al. in simulations of protostars with low and moderate accretion rates. At the high accretion rate that characterizes the FUOR outburst phase, the radius rm at which the disc is truncated by the stellar magnetic field moves much closer to the stellar surface, but the basic properties of the outflow, which is launched from the vicinity of rm along opened-up stellar magnetic field lines, remain the same. These properties are distinct from those of the X-celerator (or the closely related X-wind) mechanism proposed by Shu et al. - in particular, the outflow is driven from the start by the magnetic pressure gradient force, not centrifugally, and it is more strongly collimated. We show that the simulated outflow can in principle account for the main observed characteristics of FUOR winds, including

  12. Millimeter interferometric observations of FU Orionis-type objects in Cygnus

    NASA Astrophysics Data System (ADS)

    Kóspál, Á.

    2011-11-01

    Context. FU Orionis-type objects (FUors) are low-mass young eruptive stars that probably represent an evolutionary phase characterized by episodic periods of increased accretion rate from the circumstellar disk to the star. Theory predicts that a circumstellar envelope, the source of continuous mass infall onto the disk, is necessary for triggering such accretion bursts. Aims: We intend to study the spatial and velocity structure of circumstellar envelopes around FUors by means of molecular line observations at millimeter wavelengths. We target three prototypical FUors, as well as an object possibly in a pre-outburst state. Methods: We present archival PdBI interferometric observations of the J = 1-0 line of 13CO at 110.2 GHz. For three of our targets, these represent the first millimeter interferometric observations. The data allow study of the molecular environment of the objects with a spatial resolution of a thousand AU and a velocity resolution of 0.2 km s-1. Results: Strong, narrow 13CO(1-0) line emission is detected from all sources. The emission is spatially resolved in all cases, with deconvolved sizes of a few thousand AUs. For V1057 Cyg and V1331 Cyg, the emitting area is rather compact, suggesting that the origin of the emission is a circumstellar envelope surrounding the central star. For V1735 Cyg, the 13CO emission is offset from the stellar position, indicating that the source of this emission may be a small foreground cloud, also responsible for the high reddening of the central star. The 13CO emission towards V1515 Cyg is the most extended in the sample, and it apparently coincides with the ring-like optical reflection nebula associated with V1515 Cyg. Conclusions: We suggest that millimeter interferometric observations are indispensable for a complete understanding of the circumstellar environment of FUors. Any theory of the FUor phenomenon that interprets the geometry of the circumstellar structure and its evolution using single

  13. The {Lambda}(1405) in Full QCD

    SciTech Connect

    Menadue, Benjamin J.; Kamleh, Waseem; Leinweber, Derek B.; Mahbub, M. Selim

    2011-12-14

    At 1405.1 MeV, the lowest-lying negative-parity state of the {Lambda} baryon lies surprising low. Indeed, this is lower than the lowest negative-parity state of the nucleon, even though the {Lambda}(1405) possesses a valence strange quark. However, previous Lattice QCD studies have been unable to identify such a low-lying state. Using the PACS-CS (2+1)-flavour full-QCD ensembles, available through the ILDG, we utilise a variational analysis with source and sink smearing to isolate this elusive state. We find three low-lying odd-parity states, and for the first time reproduce the correct level ordering with respect to the nearby scattering thresholds.

  14. The lambda point experiment in microgravity

    NASA Technical Reports Server (NTRS)

    Lipa, J. A.

    1988-01-01

    The motivation and potential for performing very high resolution measurements of the heat capacity singularity at the lambda point of helium in microgravity conditions was briefly discussed. It is clear that tests extending deep into the asymptotic region can be performed, where the theoretical predictions take on their simplest form. This advantageous situation should lead to a major improvement in the understanding of the range of applicability of current theoretical ideas in this field. The lambda transition holds out the prospect of giving the maximum advance of any system, and with the application of cryogenic techniques, the potential of this system can be realized. The technology for the initial experiments is already developed, and results could be obtained in 1990.

  15. Overview of the Lambda-* Performance Reasoning Frameworks

    DTIC Science & Technology

    2009-02-01

    to check the satisfaction of these kinds of quality requirements have existed for several years, they are still not widely used because typical...sporadic server algorithm [Sprunt 1989]. The Lambda-* reasoning frameworks make the use of existing and new analysis theories (e.g., GRMA and the theory...sink pins within the same response can be ready to execute at the same time, they must have different priorities. These constraints exist for very

  16. Regulation of replication of lambda phage and lambda plasmid DNAs at low temperature.

    PubMed

    Gabig, M; Obuchowski, M; Srutkowska, S; Wegrzyn, G

    1998-06-01

    It was previously demonstrated that while lysogenic development of bacteriophage lambda in Escherichia coli proceeds normally at low temperature (20-25 degrees C), lytic development is blocked under these conditions owing to the increased stability of the phage CII protein. This effect was proposed to be responsible for the increased stimulation of the pE promoter, which interferes with expression of the replication genes, leading to inhibition of phage DNA synthesis. Here we demonstrate that the burst size of phage lambda cIb2, which is incapable of lysogenic development, increases gradually over the temperature range from 20 to 37 degrees C, while no phage progeny are observed at 20 degrees C. Contrary to previous reports, it is possible to demonstrate that pE promoter activation by CII may be more efficient at lower temperature. Using density-shift experiments, we found that phage DNA replication is completely blocked at 20 degrees C. Phage growth was also inhibited in cells overexpressing cII, which confirms that CII is responsible for inhibition of phage DNA replication. Unexpectedly, we found that replication of plasmids derived from bacteriophage lambda is neither inhibited at 20 degrees C nor in cells overexpressing cII. We propose a model to explanation the differences in replication observed between lambda phage and lambda plasmid DNA at low temperature.

  17. Differential Photoproduction Cross Sections of the Sigma0(1385), Lambda(1405), and Lambda(1520)

    SciTech Connect

    Moriya, Kei; Schumacher, Reinhard A.

    2013-10-01

    We report the exclusive photoproduction cross sections for the Sigma(1385), Lambda(1405), and Lambda(1520) in the reactions gamma + p -> K+ + Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective Lagrangian approach and fitted to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Lambda(1405) region are strikingly different for the Sigma+pi-, Sigma0 pi0, and Sigma- pi+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.

  18. Modelado de las Distribuciones Espectrales de Energía de tres nuevas estrellas jóvenes de tipo FU Orionis

    NASA Astrophysics Data System (ADS)

    Gramajo, L. V.; Rodón, J.; Gómez, M.; Whitney, B.

    In this work we present the modeling of the spectral energy distributions (SEDs) of three protostellar objects of the FU Orionis type, for which an outburst was observed in the last two years. We applied the code developed by Whitney et al. (ApJ 591, 1049, 2003) to model the SEDs. We derived physical and geometric parameters for each object, which agree with those previously obtained for other FU Orionis type stars. Furthermore, the three objects were studied in their stages of high and low activity. Our results suggest that the disk plays a key role in the outburst event, which is reflected in an increase of at least one order of magnitude of the mass accretion rate from the disk to the central object, with respect to the low activity period. FULL TEXT IN SPANISH

  19. A white dwarf companion to the main-sequence star 4 Omicron(1) Orionis and the binary hypothesis for the origin of peculiar red giants

    NASA Technical Reports Server (NTRS)

    Ake, Thomas B.; Johnson, Hollis R.

    1988-01-01

    Ultraviolet spectra of the peculiar red giants (PRGs) called MS stars are investigated, and the discovery of a white dwarf (WD) companion to the MS star 4 Omicron(1) Orionis is reported. The observations and data analysis are discussed and compared with those for field WDs in order to derive parameters for the WD and the luminosity of the primary. Detection limits for the other MS stars investigated are derived, and the binary hypothesis for PRGs is reviewed.

  20. Measurement of the Lambda0b lifetime in the decay lambda0b--> J/psiLambda0 with the D0 detector.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Agelou, M; Agram, J-L; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Anderson, S; Andrieu, B; Arnoud, Y; Askew, A; Asman, B; Atramentov, O; Autermann, C; Avila, C; Badaud, F; Baden, A; Baldin, B; Balm, P W; Banerjee, S; Barberis, E; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beauceron, S; Begel, M; Bellavance, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Blumenschein, U; Boehnlein, A; Boeriu, O; Bolton, T A; Borcherding, F; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burnett, T H; Busato, E; Butler, J M; Bystricky, J; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Chevalier, L; Cho, D K; Choi, S; Christiansen, T; Christofek, L; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Coss, J; Cothenet, A; Cousinou, M-C; Crépé-Renaudin, S; Cristetiu, M; Cummings, M A C; Cutts, D; da Motta, H; Davies, B; Davies, G; Davis, G A; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Dean, S; Déliot, F; Delsart, P A; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doidge, M; Dong, H; Doulas, S; Duflot, L; Dugad, S R; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Eltzroth, J T; Elvira, V D; Eno, S; Ermolov, P; Eroshin, O V; Estrada, J; Evans, D; Evans, H; Evdokimov, A; Evdokimov, V N; Fast, J; Fatakia, S N; Feligioni, L; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Freeman, W; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gardner, J; Gavrilov, V; Gay, P; Gelé, D; Gelhaus, R; Genser, K; Gerber, C E; Gershtein, Y; Ginther, G; Golling, T; Gómez, B; Gounder, K; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Gris, Ph; Grivaz, J-F; Groer, L; Grünendahl, S; Grünewald, M W; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Hagopian, S; Hall, I; Hall, R E; Han, C; Han, L; Hanagaki, K; Harder, K; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Houben, P; Hu, Y; Huang, J; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jenkins, A; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jonsson, P; Jöstlein, H; Juste, A; Kado, M M; Käfer, D; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J; Karmanov, D; Kasper, J; Kau, D; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A; Kharzheev, Y M; Kim, K H; Klima, B; Klute, M; Kohli, J M; Kopal, M; Korablev, V M; Kotcher, J; Kothari, B; Koubarovsky, A; Kozelov, A V; Kozminski, J; Krzywdzinski, S; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kurca, T; Lager, S; Lahrichi, N; Landsberg, G; Lazoflores, J; Le Bihan, A-C; Lebrun, P; Lee, S W; Lee, W M; Leflat, A; Lehner, F; Leonidopoulos, C; Lewis, P; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J; Lipaev, V V; Lipton, R; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Lubatti, H J; Lueking, L; Lynker, M; Lyon, A L; Maciel, A K A; Madaras, R J; Mättig, P; Magerkurth, A; Magnan, A-M; Makovec, N; Mal, P K; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martens, M; Mattingly, S E K; Mayorov, A A; McCarthy, R; McCroskey, R; Meder, D; Melanson, H L; Melnitchouk, A; Merkin, M; Merritt, K W; Meyer, A; Miettinen, H; Mihalcea, D; Mitrevski, J; Mokhov, N; Molina, J; Mondal, N K; Montgomery, H E; Moore, R W; Muanza, G S; Mulders, M; Mutaf, Y D; Nagy, E; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neustroev, P; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; Nurse, E; O'dell, V; O'Neil, D C; Oguri, V; Oliveira, N; Oshima, N; Otero Y Garzón, G J; Padley, P; Parashar, N; Park, J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Perea, P M; Perez, E; Peters, O; Pétroff, P; Petteni, M; Phaf, L; Piegaia, R; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pope, B G; da Silva, W L Prado; Prosper, H B; Protopopescu, S; Przybycien, M B; Qian, J; Quadt, A; Quinn, B; Rani, K J; Rapidis, P A; Ratoff, P N; Reay, N W; Reucroft, S; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Royon, C; Rubinov, P; Ruchti, R; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Schellman, H; Schieferdecker, P; Schmitt, C; Schukin, A A; Schwartzman, A; Schwienhorst, R; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shephard, W D; Shpakov, D; Sidwell, R A; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smith, R P; Smolek, K; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Song, Y; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stanton, N R; Stark, J; Steele, J; Steinbrück, G; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tamburello, P; Taylor, W; Telford, P; Temple, J; Tentindo-Repond, S; Thomas, E; Thooris, B; Tomoto, M; Toole, T; Torborg, J; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vlimant, J-R; Von Toerne, E; Vreeswijk, M; Vu Anh, T; Wahl, H D; Walker, R; Wang, L; Wang, Z-M; Warchol, J; Warsinsky, M; Watts, G; Wayne, M; Weber, M; Weerts, H; Wegner, M; Wermes, N; White, A; White, V; Whiteson, D; Wicke, D; Wijngaarden, D A; Wilson, G W; Wimpenny, S J; Wittlin, J; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Xu, Q; Xuan, N; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yen, Y; Yip, K; Youn, S W; Yu, J; Yurkewicz, A; Zabi, A; Zatserklyaniy, A; Zdrazil, M; Zeitnitz, C; Zhang, D; Zhang, X; Zhao, T; Zhao, Z; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zitoun, R; Zutshi, V; Zverev, E G; Zylberstejn, A

    2005-03-18

    We present measurements of the Lambda(0)(b) lifetime in the exclusive decay channel Lambda(0)(b)--> J/psiLambda(0), with J/psi--> mu(+)mu(-) and Lambda(0)--> ppi(-), the B0 lifetime in the decay B0-->J/psiK(0)(S) with J/psi--> mu(+)mu(-) and K(0)(S)-->pi(+)pi(-), and the ratio of these lifetimes. The analysis is based on approximately 250 pb(-1) of data recorded with the D0 detector in pp collisions at sqrt[s] = 1.96 TeV. The Lambda(0)(b) lifetime is determined to be tau(Lambda(0)(b)) = 1.22(+0.22)(-0.18)(stat) +/- 0.04(syst) ps, the B0 lifetime tau(B0) = 1.40(+0.11)(-0.10)(stat) +/- 0.03(syst) ps, and the ratio tau(Lambda(0)(b))/tau(B0) = 0.87(+0.17)(-0.14)(stat) +/- 0.03(syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda(0)(b) lifetime based on a fully reconstructed decay channel.

  1. The evolution of groups and clusters

    NASA Astrophysics Data System (ADS)

    Gottlöber, S.; Klypin, A.; Kravtsov, A. V.; Turchaninov, V.

    Using high resolution N -body simulations we study the formation and evolution of clusters and groups in a &Lambda CDM cosmological model. Groups of galaxies already form before z = 4. Merging of groups and accretion leads to cluster formation at z <&sim2. Some of the groups merge into large isolated halos.

  2. Remarks on the generalized Tukey's lambda family of distributions

    SciTech Connect

    Lam, H.; Bowman, K.O.; Shenton, L.R.

    1980-01-01

    The family of curves generated by the mapping of the uniform density F/sup -1/(lambda) = ..cap alpha.. + ..beta..(lambda/sup ..gamma..delta/ - (1-lambda)/sup ..gamma../)/..gamma.., 0 < lambda < 1, is considered. Primary interest is the application of the above density to approximating theoretical distribution functions of test statistics such as S.D., skewness, and kurtosis under non-normality. Moments are straight forward to evaluate in terms of gamma functions, or polygamma functions in special cases. 1 figure, 8 tables. (RWR)

  3. Charge-symmetry breaking {Lambda}-nucleon interaction

    SciTech Connect

    Bodmer, A.R.; Murali, M.; Usmani, Q.N.

    1995-08-01

    Some time ago we showed that the charge-symmetry-breaking interaction, as obtained from the mass four hypernuclei ({sub {Lambda}}{sup 4}H, {sub {Lambda}}{sup 4}He), was spin-independent; a result which cannot be understood with the conventional meson-exchange models. The calculations of ({sub {Lambda}}{sup 4}H, {sub {Lambda}}{sup 4}He) are currently being extended to include noncentral nuclear and hypernuclear forces which could modify this result. At a more fundamental level we intend to study quark-structure contributions to the charge-symmetry-breaking interaction.

  4. Microscopic theory of the lambda transition

    SciTech Connect

    Toyoda, T.

    1982-06-01

    Starting with a microscopic hamiltonian for a many-boson system with a hardcore interaction, the grand potential of the system, which contains the order-parameter of the lambda transition as one of the thermodynamical variables, is derived by making use of the finite temperature loop expansion. The divergence difficulty caused by the hardcore interaction is circumvented by the conventional field theoretic perturbation renormalization such that the chemical potential is renormalized instead of the conventional mass renormalization. The grand potential obtained consists of the superfluid part and the finite temperature elementary excitation part. The elementary excitation energy spectrum shows the Goldstone boson mode, namely, the photon, for the zero external field. A non-vanishing external field destroys such a Goldstone boson mode by causing an energy gap at zero momentum. The chemical potential and the critical temperature are also obtained for the weak coupling case. It is shown how the Bose-Einstein condensation is affected by the hardcore interaction.

  5. Lambda-instability of Keplerian orbits

    NASA Astrophysics Data System (ADS)

    Dumin, Yurii

    Although the Lambda-term is commonly recognized to be of crucial importance for the large-scale (cosmological) dynamics, its influence can be appreciable also at much less scales, particularly, for the long-term evolution of Keplerian orbits. Such effects were studied in the recent years in a number of papers, e.g. [1, 2]; however this was done only under the assumption of static de Sitter asymptotics at infinity. A more realistic treatment of this problem should be based, evidently, on the nonstationary Friedmann-Robertson-Walker asymptotics, which is commonly accepted in modern cosmology; and such an approach was outlined in our earlier paper [3]. The present report is devoted to the results of numerical integration of the equations of motion of a test particle experiencing a gravitational field of the massive central body against the Lambda-background. Apart from the tiny secular effect of Hubble type, which is naturally expected and was already discussed before [4], we have found a strong instability, which can develop at certain values of the orbital parameters. The growth rate of this instability is much larger than the typical Hubble velocity, and it can eventually lead to disruption of the Keplerian orbit and injection of the test particle with a considerable velocity. From our point of view, the revealed phenomenon may have important astrophysical applications, particularly, for explanation of the very fast proper motions of some stars, anomalous interstellar separation in multiple systems, etc. References: 1. A. Balaguera-Antolínez, C.G. Böhmer, M. Nowakowski. Class. Quant. Grav., v.23, p.485 (2006). 2. V. Kagramanova, J. Kunz, C Lämmerzahl. Phys. Lett. B, v.634, p.465 (2006). 3. Yu.V. Dumin. Phys. Rev. Lett., v.98, p.059001 (2007). 4. Yu.V. Dumin. Proc. 11th Marcel Grossmann Meeting on General Relativity (World Sci., Singapore, 2008), p.1752.

  6. Correlation between UV dose requirement for lambda bacteriophage induction and lambda repressor concentration.

    PubMed Central

    Baluch, J; Sussman, R

    1978-01-01

    Escherichia coli K-12 wild type and a uvrA mutant derivative were used to construct isogenic strains bearing one, two, three, or more phage lambda cI genomes and containing increasing concentration of lambda repressor as measured by in vitro operator DNA-binding assays. The survival and phage induction in response to UV irradiation were determined. In both strains, dose-response relationships were obtained as a function of the cellular repressor concentration. The uvrA lysogens required one-tenth the UV fluence of the wild-type counterparts for induction. Lysogenic strains containing plasmids that overproduce the lambdaind+ repressor and the same lysogens with plasmids overproducing the lambdaind- repressor displayed the same survival curves as the nonlysogenic parental strain; however, only the former produced infectious centers (at a frequency of 2 x 10(-3) to 5 x 10(-4) in response to radiation. PMID:353300

  7. High Resolution Spectroscopy of 16N_Lambda by Electroproduction

    SciTech Connect

    Cusanno, Francesco; Urciuoli, Guido; Acha Quimper, Armando; Ambrozewicz, Pawel; Aniol, Konrad; Baturin, Pavlo; Bertin, Pierre; Benaoum, Hachemi; Blomqvist, Ingvar; Boeglin, Werner; Breuer, Herbert; Brindza, Paul; Bydzovsky, Petr; Camsonne, Alexandre; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Cisbani, Evaristo; Colilli, Stefano; Coman, Luminita; Craver, Brandon; de Cataldo, Giacinto; De Jager, Cornelis; De Leo, Raffaele; Deur, Alexandre; Ferdi, Catherine; Feuerbach, Robert; Folts, Edward; Frullani, Salvatore; Garibaldi, Franco; Gayou, Olivier; Giuliani, Fausto; Gomez, Javier; Gricia, Massimo; Hansen, Jens-Ole; Hayes, David; Higinbotham, Douglas; Holmstrom, Timothy; Hyde, Charles; Ibrahim, Hassan; Iodice, Mauro; Jiang, Xiaodong; Kaufman, Lisa; Kino, Kouichi; Kross, Brian; Lagamba, Luigi; LeRose, John; Lindgren, Richard; Lucentini, Maurizio; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Meziani, Zein-Eddine; McCormick, Kathy; Michaels, Robert; Millener, D.; Miyoshi, Toshinobu; Moffit, Bryan; Monaghan, Peter; Moteabbed, Maryam; Munoz Camacho, Carlos; Nanda, Sirish; Nappi, E.; Nelyubin, Vladimir; Norum, Blaine; Okasyasu, Y.; Paschke, Kent; Perdrisat, Charles; Piasetzky, Eliazer; Punjabi, Vina; Qiang, Yi; Raue, Brian; Reimer, Paul; Reinhold, Joerg; Reitz, Bodo; Roche, Rikki; Rodriguez, Victor; Saha, Arunava; Santavenere, Fabio; Sarty, Adam; Segal, John; Shahinyan, Albert; Singh, Jaideep; Sirca, Simon; Snyder, Ryan; Solvignon, Patricia; Sotona, M.; Sotona, Miloslav; Sotona, M.; Sotona, Miloslav; Sotona, M.; Sotona, Miloslav; Sotona, M.; Sotona, Miloslav; Subedi, Ramesh; Sulkosky, Vince; Sulkosky, Vincent; Sulkosky, Vince; Sulkosky, Vincent; Suzuki, Tomokazu; Ueno, Hiroaki; Ulmer, Paul; Veneroni, P.P.; Voutier, Eric; Wojtsekhowski, Bogdan; Zeng, X.; Zorn, Carl

    2009-01-01

    An experimental study of the 16O(e, e'K+)16N_Lambda reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e, e'K+)Lambda,Sigma_0 exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76 ± 0.16 MeV was obtained for 16N_Lambda with better precision than previous measurements on the mirror hypernucleus 16O_Lambda. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p1/2 and p3/2 hole states of the 15N core nucleus.

  8. Phillips' Lambda function: Data summary and physical model

    NASA Astrophysics Data System (ADS)

    Irisov, V.; Plant, W.

    2016-03-01

    Measurements of Phillips' Lambda function describing the average length of breakers on the ocean per unit area at speed cb are summarized. An expression is developed that fits these data within reasonable bounds. A physical model for the Lambda function is derived based on the assumption that breaking occurs when the surface steepness exceeds a threshold value. The energy contained in the breaking region is related to the fifth power of the breaker speed, as Phillips showed, and from this the probability of finding a breaker with a speed cb may be determined from a simulation of the long-wave surface based on a linear superposition of Fourier components. This probability is directly related to the Lambda function so that a form for this function can be determined. The Lambda function so determined agrees in both shape and intensity with the fit to the measured Lambda functions.

  9. Tertiary structure of human {Lambda}6 light chains.

    SciTech Connect

    Pokkuluri, P. R.; Solomon, A.; Weiss, D. T.; Stevens, F. J.; Schiffer, M.; Center for Mechanistic Biology and Biotechnology; Univ. of Tennessee Medical Center /Graduate School of Medicine

    1999-01-01

    AL amyloidosis is a disease process characterized by the pathologic deposition of monoclonal light chains in tissue. To date, only limited information has been obtained on the molecular features that render such light chains amyloidogenic. Although protein products of the major human V kappa and V lambda gene families have been identified in AL deposits, one particular subgroup--lambda 6--has been found to be preferentially associated with this disease. Notably, the variable region of lambda 6 proteins (V lambda 6) has distinctive primary structural features including the presence in the third framework region (FR3) of two additional amino acid residues that distinguish members of this subgroup from other types of light chains. However, the structural consequences of these alterations have not been elucidated. To determine if lambda 6 proteins possess unique tertiary structural features, as compared to light chains of other V lambda subgroups, we have obtained x-ray diffraction data on crystals prepared from two recombinant V lambda 6 molecules. These components, isolated from a bacterial expression system, were generated from lambda 6-related cDNAs cloned from bone marrow-derived plasma cells from a patient (Wil) who had documented AL amyloidosis and another (Jto) with multiple myeloma and tubular cast nephropathy, but no evident fibrillar deposits. The x-ray crystallographic analyses revealed that the two-residue insertion located between positions 68 and 69 (not between 66 and 67 as previously surmised) extended an existing loop region that effectively increased the surface area adjacent to the first complementarity determining region (CDR1). Further, an unusual interaction between the Arg 25 and Phe 2 residues commonly found in lambda 6 molecules was noted. However, the structures of V lambda 6 Wil and Jto also differed from each other, as evidenced by the presence in the latter of certain ionic and hydrophobic interactions that we posit increased protein

  10. Measurement of the production fraction times branching fraction $\\boldsymbol{ f(b\\to\\Lambda_{b})\\cdot \\mathcal{B}(\\Lambda_{b}\\to J/\\psi \\Lambda)}$

    SciTech Connect

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; Alverson, George O.; Alves, Gilvan Augusto; Ancu, Lucian Stefan; /Nijmegen U. /Fermilab

    2011-05-01

    The {Lambda}{sub b}(udb) baryon is observed in the decay {Lambda}{sub b} {yields} J/{psi}{Lambda} using 6.1 fb{sup -1} of p{bar p} collisions collected with the D0 detector at {radical}s = 1.96 TeV. The production fraction multiplied by the branching fraction for this decay relative to that for the decay B{sup 0} {yields} J/{psi}K{sub s}{sup 0} is measured to be 0.345 {+-} 0.034 (stat.) {+-} 0.033 (syst.) {+-} 0.003 (PDG). Using the world average value of f(b {yields} B{sup 0}) {center_dot} {Beta}(B{sup 0} {yields} J/{psi}K{sub s}{sup 0}) = (1.74 {+-} 0.08) x 10{sup -5}, they obtain f(b {yields} {Lambda}{sub b}) {center_dot} {Beta}({Lambda}{sub b} {yields} J/{psi}{Lambda}) = (6.01 {+-} 0.60 (stat.) {+-} 0.58 (syst.) {+-} 0.28 (PDG)) x 10{sup -5}. This measurement represents an improvement in precision by about a factor of three with respect to the current world average.

  11. Atmospheric Phase Correction Using CARMA-PACS: High Angular Resolution Observations of the FU Orionis Star PP 13S*

    NASA Astrophysics Data System (ADS)

    Pérez, Laura M.; Lamb, James W.; Woody, David P.; Carpenter, John M.; Zauderer, B. Ashley; Isella, Andrea; Bock, Douglas C.; Bolatto, Alberto D.; Carlstrom, John; Culverhouse, Thomas L.; Joy, Marshall; Kwon, Woojin; Leitch, Erik M.; Marrone, Daniel P.; Muchovej, Stephen J.; Plambeck, Richard L.; Scott, Stephen L.; Teuben, Peter J.; Wright, Melvyn C. H.

    2010-11-01

    We present 0farcs15 resolution observations of the 227 GHz continuum emission from the circumstellar disk around the FU Orionis star PP 13S*. The data were obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) Paired Antenna Calibration System (C-PACS), which measures and corrects the atmospheric delay fluctuations on the longest baselines of the array in order to improve the sensitivity and angular resolution of the observations. A description of the C-PACS technique and the data reduction procedures are presented. C-PACS was applied to CARMA observations of PP 13S*, which led to a factor of 1.6 increase in the observed peak flux of the source, a 36% reduction in the noise of the image, and a 52% decrease in the measured size of the source major axis. The calibrated complex visibilities were fitted with a theoretical disk model to constrain the disk surface density. The total disk mass from the best-fit model corresponds to 0.06 M sun, which is larger than the median mass of a disk around a classical T Tauri star. The disk is optically thick at a wavelength of 1.3 mm for orbital radii less than 48 AU. At larger radii, the inferred surface density of the PP 13S* disk is an order of magnitude lower than that needed to develop a gravitational instability.

  12. ATMOSPHERIC PHASE CORRECTION USING CARMA-PACS: HIGH ANGULAR RESOLUTION OBSERVATIONS OF THE FU ORIONIS STAR PP 13S*

    SciTech Connect

    Perez, Laura M.; Carpenter, John M.; Isella, Andrea; Lamb, James W.; Woody, David P.; Leitch, Erik M.; Muchovej, Stephen J.; Scott, Stephen L.; Zauderer, B. Ashley; Bolatto, Alberto D.; Teuben, Peter J.; Bock, Douglas C.; Carlstrom, John; Culverhouse, Thomas L.; Marrone, Daniel P.; Joy, Marshall; Kwon, Woojin; Plambeck, Richard L.; Wright, Melvyn C. H.

    2010-11-20

    We present 0.''15 resolution observations of the 227 GHz continuum emission from the circumstellar disk around the FU Orionis star PP 13S*. The data were obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) Paired Antenna Calibration System (C-PACS), which measures and corrects the atmospheric delay fluctuations on the longest baselines of the array in order to improve the sensitivity and angular resolution of the observations. A description of the C-PACS technique and the data reduction procedures are presented. C-PACS was applied to CARMA observations of PP 13S*, which led to a factor of 1.6 increase in the observed peak flux of the source, a 36% reduction in the noise of the image, and a 52% decrease in the measured size of the source major axis. The calibrated complex visibilities were fitted with a theoretical disk model to constrain the disk surface density. The total disk mass from the best-fit model corresponds to 0.06 M{sub sun}, which is larger than the median mass of a disk around a classical T Tauri star. The disk is optically thick at a wavelength of 1.3 mm for orbital radii less than 48 AU. At larger radii, the inferred surface density of the PP 13S* disk is an order of magnitude lower than that needed to develop a gravitational instability.

  13. Exclusive semileptonic decays of {lambda}{sub b}{yields}{lambda}l{sup +}l{sup -} in supersymmetric theories

    SciTech Connect

    Aslam, M. Jamil; Wang Yuming; Lue Caidian

    2008-12-01

    The weak decays of {lambda}{sub b}{yields}{lambda}l{sup +}l{sup -} (l=e, {mu}) are investigated in the minimal supersymmetric standard model (MSSM) and also in supersymmetric (SUSY) SO(10) grand unified models. In the MSSM special attention is paid to the neutral Higgs bosons (NHBs) as they make quite a large contribution in exclusive B{yields}X{sub s}l{sup +}l{sup -} decays at large tan{beta} regions of parameter space of SUSY models, since part of SUSY contributions is proportional to tan{sup 3}{beta}. The analysis of decay rate, forward-backward asymmetries, lepton polarization asymmetries, and the polarization asymmetries of the {lambda} baryon in {lambda}{sub b}{yields}{lambda}l{sup +}l{sup -} show that the values of these physical observables are greatly modified by the effects of NHBs. In the SUSY SO(10) grand unified theory model, the new physics contribution comes from the operators which are induced by the NHBs' penguins and also from the operators having chirality opposite to that of the corresponding standard model (SM) operators. SUSY SO(10) effects show up only in the decay {lambda}{sub b}{yields}{lambda}+{tau}{sup +}{tau}{sup -} where the longitudinal and transverse lepton polarization asymmetries deviate significantly from the SM value while the effects in the decay rate, forward-backward asymmetries, and polarization asymmetries of final state {lambda} baryon are very mild. The transverse lepton polarization asymmetry in {lambda}{sub b}{yields}{lambda}+{tau}{sup +}{tau}{sup -} is almost zero in the SM and in the MSSM model. However, it can reach to -0.1 in the SUSY SO(10) grand unified theory model and could be seen at the future colliders; hence this asymmetry observable will provide us useful information to probe new physics and discriminate between different models.

  14. The Structure and Function of the DNA from Bacteriophage Lambda

    PubMed Central

    Hogness, David S.

    1966-01-01

    The position and orientation of genes in lambda and lambda dg DNA are described. The position of six genes located in the right half of isolated lambda DNA was found to be -(N, iλ)--O-P---Q-R-(right end of DNA), which is their order on the genetic map of the vegetative phage. The order of the three genes of the galactose operon (k, t, and e) located in the left half of lambda dg DNA was found to be (left end of DNA)----k-t-e-, consistent with Campbell's model (5) for the formation of this variant. Gene orientation, defined as the direction of transcription along the DNA, is inferred to be from right to left for the galactose operon in lambda dg DNA. The strand of lambda DNA which functions as template in transcription of N, an "early" gene required for normal replication of lambda DNA, was determined as a first step in ascertaining the orientation of this gene. The method includes isolation of each strand, formation of each of two heteroduplex molecules consisting of one strand from wild-type and one from an N mutant) and comparison of their N activities. The second step, which consists of ascertaining the 5'-to-3' direction of each strand, is discussed, as is a determination of the orientation of gene R. PMID:5967430

  15. Hepatopancreatic intoxication of lambda cyhalothrin insecticide on albino rats

    PubMed Central

    Elhalwagy, Manal EA; Abd-Alrahman, Sherif H; Nahas, AA; Ziada, Reem M; Mohamady, Aziza H

    2015-01-01

    Background: Despite the known adverse effects of lambda cyhalothrin insecticide, little is known about its hepatopancreatic intoxication effects. The present study was carried out to elucidate sub-chronic effect of Karat 2.5% EC formulation of lambda cyhalothrin on male albino rats. Methods: To explore the effects of exposure to lambda cyhalothrin on rats and its mechanism, low (1/40 of LD50, 5 mg/kg/day) and high dose (1/4 of LD50, 50 mg/kg/day) lambda cyhalothrin were applied to rats via drinking water for 3 months. Blood samples were collected monthly, and the animals were dissected for liver and pancreas’s examination at the end of the experiment. Lambda cyhalothrin administration was associated with the elevation in lipid peroxidation marker, malondialdehyde (MDA), reduction in SH-protein a major marker for antioxidant, as well as basel paraoxonase (PON) in both treated groups throughout the experimental periods. Results: In addition, significant elevations in liver enzymes alanin amino transferase, (ALT), and aspartate amino transferase (AST), as well as plasma acetylcholinesterase (AChE) and glucose level. While, significant reduction in insulin level through the experimental periods. Results of histopathological and histochemical studies showed that lambda cyhalothrin exposure induces liver and pancreatic tissues damage and depletion in glycogen content was pronounced in liver of both treated groups. Conclusions: In conclusion subchronic intoxication with lambda cyhalothrin formulation induced remarkable changes in the examined parameters. PMID:26221269

  16. The control of lambda DNA terminase synthesis.

    PubMed Central

    Murialdo, H; Davidson, A; Chow, S; Gold, M

    1987-01-01

    Nu1 and A, the genes coding for bacteriophage lambda DNA terminase, rank among the most poorly translated genes expressed in E. coli. To understand the reason for this low level of translation the genes were cloned into plasmids and their expression measured. In addition, the wild type DNA sequences immediately preceding the genes were reduced and modified. It was found that the elements that control translation are contained in the 100 base pairs upstream from the initiation codon. Interchanging these upstream sequences with those of an efficiently translated gene dramatically increased the translation of terminase subunits. It seems unlikely that the rare codons present in the genes, and any feature of their mRNA secondary structure play a role in the control of their translation. The elimination of cos from plasmids containing Nu1 and A also resulted in an increase in terminase production. This result suggests a role for cos in the control of late gene expression. The terminase subunit overproducer strains are potentially very useful for the design of improved DNA packaging and cosmid mapping techniques. Images PMID:3029667

  17. Lambda Probe Measurements of Laboratory Spheromaks

    NASA Astrophysics Data System (ADS)

    Jorne, E.; Bellan, P. M.; Hsu, S. C.; Moynihan, C.

    2003-10-01

    A combined current and magnetic probe (lambda probe) has been constructed and is being tested for the purpose of investigating the behavior of spheromaks formed by the Caltech planar spheromak gun. The probe consists of a 1.5cm diameter, 52 turn Rogowski coil and a single loop magnetic coil, housed in a ceramic shell attached to a 95cm long hollow, steel shaft. A high voltage power supply was used to test the probe's ability to measure pulsed currents with submicrosecond rise times. A calibrated current pulse was provided by a 1μF capacitor discharged by a krytron switch to a low inductance circuit. Magnetic calibration was obtained by using the capacitor bank to power a 16cm diameter Helmholtz coil. Both magnetic and current calibration were in good agreement with estimates based on geometry. An existing steel shaft will be replaced by a ceramic shaft in order to minimize undesired effects on the plasma by a conductor. Once sealed with epoxy, the probe will be ready for insertion into the vacuum chamber and used to measure the magnetic field and parallel current during spheromak formation.

  18. Observation of the Baryonic B decay B0bar to Lambda_c^+ anti-Lambda K-

    SciTech Connect

    Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U., Comp. Sci. Dept. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /INFN, Milan /Milan U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /INFN, Naples /Naples U. /INFN, Naples /Naples U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /Padua U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /INFN, Padua /INFN, Padua /Padua U. /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /Sassari U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-11-08

    The authors report the observation of the baryonic B decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +} {bar {Lambda}}K{sup -} with a significance larger than 7 standard deviations based on 471 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. They measure the branching fraction for the decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +} {bar {Lambda}}K{sup -} to be (3.8 {+-} 0.8{sub stat} {+-} 0.2{sub sys} {+-} 1.0 {sub {Lambda}{sub c}{sup +}}) x 10{sup -5}. The uncertainties are statistical, systematic, and due to the uncertainty in the {Lambda}{sub c}{sup +} branching fraction. They find that the {Lambda}{sub c}{sup +} K{sup -} invariant mass distribution shows an enhancement above 3.5 GeV/c{sup 2}.

  19. Suppression of the {Lambda}-{Sigma} coupling in nuclear matter

    SciTech Connect

    Bodmer, A.R.; Usmani, Q.N.

    1995-08-01

    We initiated a study of the modification of the coupling of the {Lambda}N to the {Sigma}N channel in nuclear matter with the Fermi hypernetted-chain variational approach. This modification of the {Lambda}N-{Sigma}N coupling is a central problem in hypernuclear physics and is related closely to the strongly repulsive three-body forces which are needed to account for hypernuclear binding energies. All earlier calculations have only considered this problem in the so-called G-matrix approximation which neglects important higher-order effects. An important result of this work will be a better understanding of the density dependence of {Lambda} binding in nuclear matter, which can then be tested in the calculation of the {Lambda} single-particle energies.

  20. The head protein D of bacterial virus lambda is related to eukaryotic chromosomal proteins.

    PubMed Central

    Witkiewicz, H; Schweiger, M

    1982-01-01

    Bacteriophage lambda structural head protein D has physiochemical properties in common with eukaryotic chromosomal proteins. It has a low affinity for hydroxylapatite, it is heat stable and acid soluble. Moreover, it cross-reacts immunologically with histones H2A and H2B. The deduced primary structure of the D protein shows striking homology to calf chromosomal high mobility group HMG-14 protein. There are two clusters of four ( LSAK , ASDE ) and one of three (APA) identical amino acid residues. Additionally the cluster ETK of protein D occurs three times in HMG-14 and 14 single identical residues are present. A mechanism for an alternative to a nucleosomal mode of nuclear DNA condensation and a possible function of HMG proteins are discussed. Images Fig. 1. Fig. 2. Fig. 3. PMID:6233140

  1. RESOLVING THE GAP AND AU-SCALE ASYMMETRIES IN THE PRE-TRANSITIONAL DISK OF V1247 ORIONIS

    SciTech Connect

    Kraus, Stefan; Espaillat, Catherine; Wilner, David J.; Ireland, Michael J.; Sitko, Michael L.; Swearingen, Jeremy R.; Werren, Chelsea; Monnier, John D.; Calvet, Nuria; Grady, Carol A.; Harries, Tim J.; Hoenig, Sebastian F.; Russell, Ray W.

    2013-05-01

    Pre-transitional disks are protoplanetary disks with a gapped disk structure, potentially indicating the presence of young planets in these systems. In order to explore the structure of these objects and their gap-opening mechanism, we observed the pre-transitional disk V1247 Orionis using the Very Large Telescope Interferometer, the Keck Interferometer, Keck-II, Gemini South, and IRTF. This allows us to spatially resolve the AU-scale disk structure from near- to mid-infrared wavelengths (1.5-13 {mu}m), tracing material at different temperatures and over a wide range of stellocentric radii. Our observations reveal a narrow, optically thick inner-disk component (located at 0.18 AU from the star) that is separated from the optically thick outer disk (radii {approx}> 46 AU), providing unambiguous evidence for the existence of a gap in this pre-transitional disk. Surprisingly, we find that the gap region is filled with significant amounts of optically thin material with a carbon-dominated dust mineralogy. The presence of this optically thin gap material cannot be deduced solely from the spectral energy distribution, yet it is the dominant contributor at mid-infrared wavelengths. Furthermore, using Keck/NIRC2 aperture masking observations in the H, K', and L' bands, we detect asymmetries in the brightness distribution on scales of {approx}15-40 AU, i.e., within the gap region. The detected asymmetries are highly significant, yet their amplitude and direction changes with wavelength, which is not consistent with a companion interpretation but indicates an inhomogeneous distribution of the gap material. We interpret this as strong evidence for the presence of complex density structures, possibly reflecting the dynamical interaction of the disk material with sub-stellar mass bodies that are responsible for the gap clearing.

  2. ClpP/ClpX-mediated degradation of the bacteriophage lambda O protein and regulation of lambda phage and lambda plasmid replication.

    PubMed

    Wegrzyn, A; Czyz, A; Gabig, M; Wegrzyn, G

    2000-01-01

    The O protein is a replication initiator that binds to the orilambda region and promotes assembly of the bacteriophage lambda replication complex. This protein, although protected from proteases by other elements of the replication complex, in a free form is rapidly degraded in the host, Escherichia coli, by the ClpP/ClpX protease. Nevertheless, the physiological role of this rapid degradation remains unclear. Here we demonstrate that the copy number of plasmids derived from bacteriophage lambda is significantly higher in wild-type cells growing in rich media than in slowly growing bacteria. However, lambda plasmid copy number in bacteria devoid of the ClpP/ClpX protease was not dependent on the bacterial growth rate and in all minimal media tested was comparable to that observed in wildtype cells growing in a rich medium. Contrary to lambda plasmid replication, the efficiency of lytic growth of bacteriophage lambda was found to be dependent on the host growth rate in both wild-type bacteria and clpP and clpX mutants. The activities of two major lambda promoters operating during the lytic development, p(R) and p(L), were found to be slightly dependent on the host growth rate. However, when p(R) activity was significantly decreased in the dnaA mutant, production of phage progeny was completely abolished at low growth rates. These results indicate that the O protein (whose level in E. coli cells depends on the activity of ClpP/ClpX protease) is a major limiting factor in the regulation of lambda plasmid replication at low bacterial growth rates. However, this protein seems to be only one of the limiting factors in the bacteriophage lambda lytic development under poor growth conditions of host cells. Therefore, it seems that the role of the rapid ClpP/ClpX-mediated proteolysis of the O protein is to decrease the efficiency of early DNA replication of the phage in slowly growing host cells.

  3. Optically active zwitterionic lambda(5)Si,lambda(5)Si'-disilicates: syntheses, crystal structures, and behavior in aqueous solution.

    PubMed

    Theis, Bastian; Burschka, Christian; Tacke, Reinhold

    2008-01-01

    The zwitterionic lambda(5)Si,lambda(5)Si'-disilicates 1-8 were synthesized and characterized by solid-state and solution NMR spectroscopy. In addition, compounds 26 H(2)O, 32 CH(3)CN, 45/2 CH(3)CN, 6CH(3)OH, 7, and 8CH(3)OHCH(3)CN were studied by single-crystal X-ray diffraction. The optically active (Delta,Delta,R,R,R,R)-configured compounds 1-8 contain two pentacoordinate (formally negatively charged) silicon atoms and two tetracoordinate (formally positively charged) nitrogen atoms. One (ammonio)alkyl group is bound to each of the two silicon centers, and two tetradentate (R,R)-tartrato(4-) ligands bridge the silicon atoms. Although these lambda(5)Si,lambda(5)Si'-disilicates contain SiO(4)C skeletons, some of them display a remarkable stability in aqueous solution as shown by NMR spectroscopy and ESI mass spectrometry.

  4. Formation of oligomeric structures from plasmid DNA carrying cos lambda that is packaged into bacteriophage lambda heads.

    PubMed Central

    Miwa, T; Matsubara, K

    1983-01-01

    Plasmids that carry cos lambda, the region necessary for lambda phage packaging and that are as small as four kilobases in size can be packaged into lambda phage heads in head-to-tail tandem oligomeric structures. Multimeric oligomers as large as undecamers have been detected. Oligomer formation depends upon the products of red and gam of lambda, and the general recombination occurs between different plasmids that share homologous DNA regions. The packaging efficiency of plasmids depends on its copy number in cells and its genome size. Upon injection into a cell, the DNA establishes itself as a plasmid in a tandem structure. When such a plasmid in a high oligomeric structure is used as the source of packaging DNA, the packaging efficiency of the plasmids is elevated. The oligomers are stable in recA cells, whereas they drift toward lower oligomers in recA+ cells. Images PMID:6217189

  5. Non-LTE radiative transfer with lambda-acceleration - Convergence properties using exact full and diagonal lambda-operators

    NASA Technical Reports Server (NTRS)

    Macfarlane, J. J.

    1992-01-01

    We investigate the convergence properties of Lambda-acceleration methods for non-LTE radiative transfer problems in planar and spherical geometry. Matrix elements of the 'exact' A-operator are used to accelerate convergence to a solution in which both the radiative transfer and atomic rate equations are simultaneously satisfied. Convergence properties of two-level and multilevel atomic systems are investigated for methods using: (1) the complete Lambda-operator, and (2) the diagonal of the Lambda-operator. We find that the convergence properties for the method utilizing the complete Lambda-operator are significantly better than those of the diagonal Lambda-operator method, often reducing the number of iterations needed for convergence by a factor of between two and seven. However, the overall computational time required for large scale calculations - that is, those with many atomic levels and spatial zones - is typically a factor of a few larger for the complete Lambda-operator method, suggesting that the approach should be best applied to problems in which convergence is especially difficult.

  6. DYNAMICS OF PLANETARY SYSTEMS IN STAR CLUSTERS

    SciTech Connect

    Spurzem, R.; Giersz, M.; Heggie, D. C.; Lin, D. N. C.

    2009-05-20

    At least 10%-15% of nearby Sunlike stars have known Jupiter-mass planets. In contrast, very few planets are found in mature open and globular clusters such as the Hyades and 47 Tuc. We explore here the possibility that this dichotomy is due to the postformation disruption of planetary systems associated with the stellar encounters in long-lived clusters. One supporting piece of evidence for this scenario is the discovery of freely floating low-mass objects in star forming regions. We use two independent numerical approaches, a hybrid Monte Carlo and a direct N-body method, to simulate the impact of the encounters. We show that the results of numerical simulations are in reasonable agreement with analytical determinations in the adiabatic and impulsive limits. They indicate that distant stellar encounters generally do not significantly modify the compact and nearly circular orbits. However, moderately close stellar encounters, which are likely to occur in dense clusters, can excite planets' orbital eccentricity and induce dynamical instability in systems that are closely packed with multiple planets. The disruption of planetary systems occurs primarily through occasional nearly parabolic, nonadiabatic encounters, though eccentricity of the planets evolves through repeated hyperbolic adiabatic encounters that accumulate small-amplitude changes. The detached planets are generally retained by the potential of their host clusters as free floaters in young stellar clusters such as {sigma} Orionis. We compute effective cross sections for the dissolution of planetary systems and show that, for all initial eccentricities, dissolution occurs on timescales that are longer than the dispersion of small stellar associations, but shorter than the age of typical open and globular clusters. Although it is much more difficult to disrupt short-period planets, close encounters can excite modest eccentricity among them, such that subsequent tidal dissipation leads to orbital decay

  7. Interferon Lambda: Modulating Immunity in Infectious Diseases

    PubMed Central

    Syedbasha, Mohammedyaseen; Egli, Adrian

    2017-01-01

    Interferon lambdas (IFN-λs; IFNL1-4) modulate immunity in the context of infections and autoimmune diseases, through a network of induced genes. IFN-λs act by binding to the heterodimeric IFN-λ receptor (IFNLR), activating a STAT phosphorylation-dependent signaling cascade. Thereby hundreds of IFN-stimulated genes are induced, which modulate various immune functions via complex forward and feedback loops. When compared to the well-characterized IFN-α signaling cascade, three important differences have been discovered. First, the IFNLR is not ubiquitously expressed: in particular, immune cells show significant variation in the expression levels of and susceptibilities to IFN-λs. Second, the binding affinities of individual IFN-λs to the IFNLR varies greatly and are generally lower compared to the binding affinities of IFN-α to its receptor. Finally, genetic variation in the form of a series of single-nucleotide polymorphisms (SNPs) linked to genes involved in the IFN-λ signaling cascade has been described and associated with the clinical course and treatment outcomes of hepatitis B and C virus infection. The clinical impact of IFN-λ signaling and the SNP variations may, however, reach far beyond viral hepatitis. Recent publications show important roles for IFN-λs in a broad range of viral infections such as human T-cell leukemia type-1 virus, rotaviruses, and influenza virus. IFN-λ also potentially modulates the course of bacterial colonization and infections as shown for Staphylococcus aureus and Mycobacterium tuberculosis. Although the immunological processes involved in controlling viral and bacterial infections are distinct, IFN-λs may interfere at various levels: as an innate immune cytokine with direct antiviral effects; or as a modulator of IFN-α-induced signaling via the suppressor of cytokine signaling 1 and the ubiquitin-specific peptidase 18 inhibitory feedback loops. In addition, the modulation of adaptive immune functions via macrophage and

  8. [Study of the antigenic structure of human immunoglobulin lambda-chain using monoclonal antibodies].

    PubMed

    Arsen'eva, E L; Bogacheva, G T; Solomon, A; Weiss, D; Ibragimov, A R; Rokhlin, O V

    1990-01-01

    Nine monoclonals against human Ig lambda chains were produced, 4 antibodies react with C-domain, 5--with V-domain of the lambda chain. Anti-C lambda domain antibodies recognize not less than 3 epitopes and one of them is expressed only on the isolated chain. Anti-V lambda antibodies bind both isolated lambda chain and intact IgG, IgM, IgA. Four epitopes are expressed by few lambda Bence Jones proteins of the III subgroup, the immunogen possessing the same isotype. The 4 mentioned epitopes represent private idiotypic determinants. The epitope 3E10 is characteristic of 50% Bence Jones proteins of the II and III V lambda-subgroups thus representing a common idiotypic determinant. Using anti-V lambda antibodies germ line variability of V lambda III proteins was analysed and the similarity of antigenic structure of normal and myeloma human Ig lambda chains was demonstrated.

  9. Measurement of the branching fraction ${\\mathcal{B}}(\\Lambda^0_b\\rightarrow \\Lambda^+_c\\pi^-\\pi^+\\pi^-)$ at CDF

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2011-12-01

    We report an analysis of the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} decay in a data sample collected by the CDF II detector at the Fermilab Tevatron corresponding to 2.4 fb{sup -1} of integrated luminosity. We reconstruct the currently largest samples of the decay modes {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2595){sup +}{pi}{sup -} (with {Lambda}{sub c}(2595){sup +} {yields} {Lambda}{sub c}{sup +}{pi}{sup +}{pi}{sup -}), {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2625){sup +}{pi}{sup -} (with {Lambda}{sub c}(2625){sup +} {yields} {Lambda}{sub c}{sup +}{pi}{sup +}{pi}{sup -}), {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455){sup ++}{pi}{sup -}{pi}{sup -} (with {Sigma}{sub c}(2455){sup ++} {yields} {Lambda}{sub c}{sup +}{pi}{sup +}), and {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455)0{pi}{sup +}{pi}{sup -} (with {Sigma}{sub c}(2455)0 {yields} {Lambda}{sub c}{sup +}{pi}{sup -}) and measure the branching fractions relative to the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} branching fraction. We measure the ratio {Beta}({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})/ {Beta}({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -})=3.04 {+-} 0.33(stat){sub -0.55}{sup +0.70}(syst) which is used to derive {Beta}({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})=(26.8{sub -11.2}{sup +11.9}) x 10{sup -3}.

  10. Measurement of the Lambda b0 lifetime in Lambda b0-->J/psi Lambda 0 in pp collisions at square root s=1.96 TeV.

    PubMed

    Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; DaRonco, S; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Labarga, L; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nahn, S; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prokoshin, F; Pronko, A; Proudfoot, J; Ptochos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-03-23

    We report a measurement of the Lambda b0 lifetime in the exclusive decay Lambda b0-->J/psi Lambda 0 in pp collisions at square root s=1.96 TeV using an integrated luminosity of 1.0 fb-1 of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, we measure tau(Lambda b0)=1.593(-0.078)(+0.083)(stat)+/-0.033(syst) ps. This is the single most precise measurement of tau(Lambda b0) and is 3.2sigma higher than the current world average.

  11. First observation and measurement of the resonant structure of the lambda_b->lambda_c pi-pi+pi- decay mode

    SciTech Connect

    Azzurri, P.; Barria, P.; Ciocci, M.A.; Donati, S.; Vataga, E.

    2009-12-01

    The authors present the first observation of the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} decay using data from an integrated luminosity of approximately 2.4 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. They also present the first observation of the resonant decays {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455){sup 0} {pi}{sup +}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, {Lambda}{sub b}{sup 0} {yields} {Sigma}{sub c}(2455){sup ++}{pi}{sup -}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2595){sup +}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}(2625){sup +}{pi}{sup -} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, and measure their relative branching ratios.

  12. Posttranscriptional control of bacteriophage lambda gene expression from a site distal to the gene.

    PubMed Central

    Guarneros, G; Montañez, C; Hernandez, T; Court, D

    1982-01-01

    The bacteriophage lambda int gene product, integrase, recombines the phage DNA with the host DNA at specific sites on each to accomplish lysogeny. The int gene is transcribed from two promoters, PL and PI, each regulated positively by lambda proteins. The expression of integrase is also controlled from a site, sib, in the b region of the phage genome. This is a unique regulatory site because it is located distal to the structural gene in relation to the promoters. The expression of int from the PL promoter is inhibited when sib is present. This effect appears to be specific for PL because sib does not cause inhibition of PI-dependent int synthesis. lambda mutants that contain alterations in the site have been isolated. Sequence analyses of the mutations reveal single base changes, spanning 37 base pairs (bp) in the b region, some 240 bp beyond the int gene. Another mutant, hef13, which has a phenotype similar to that of sib, introduces a nucleotide change within the same 37-bp region. The sib and hef mutations cluster within a region of dyad symmetry. Regulation of int synthesis by sib occurs after transcription of the int gene. There is no difference in the rate of PL-promoted int mRNA synthesis in either sib+ or sib- phage infections, yet int mRNA is less stable in the sib+ infection. Because RNase III host mutants are defective in sib regulation, processing of the PL mRNA at sib by this endoribonuclease may cause int mRNA decay and decrease int synthesis. PMID:6281759

  13. The large amplitude outburst of the young star HBC 722 in NGC 7000/IC 5070, a new FU Orionis candidate

    NASA Astrophysics Data System (ADS)

    Semkov, E. H.; Peneva, S. P.; Munari, U.; Milani, A.; Valisa, P.

    2010-11-01

    Context. The investigations of the photometric and spectral variability of PMS stars are essential to a better understanding of the early phases of stellar evolution. We are carrying out a photometric monitoring program of some fields of active star formation. One of our targets is the dark cloud region between the bright nebulae NGC 7000 and IC 5070. Aims: We report the discovery of a large amplitude outburst from the young star HBC 722 (LkHα 188 G4) located in the region of NGC 7000/IC 5070. On the basis of photometric and spectroscopic observations, we argue that this outburst is of the FU Orionis type. Methods: We gathered photometric and spectroscopic observations of the object both in the pre-outburst state and during a phase of increase in its brightness. The photometric BVRI data (Johnson-Cousins system) that we present were collected from April 2009 to September 2010. To facilitate transformation from instrumental measurements to the standard system, fifteen comparison stars in the field of HBC 722 were calibrated in the BVRI bands. Optical spectra of HBC 722 were obtained with the 1.3-m telescope of Skinakas Observatory (Crete, Greece) and the 0.6-m telescope of Schiaparelli Observatory in Varese (Italy). Results: The pre-outburst photometric and spectroscopic observations of HBC 722 show both low amplitude photometric variations and an emission-line spectrum typical of T Tau stars. The observed outburst started before May 2010 and reached its maximum brightness in September 2010, with a recorded ΔV ~ 4.7m amplitude. Simultaneously with the increase in brightness the color indices changed significantly and the star became appreciably bluer. The light curve of HBC 722 during the period of rise in brightness is similar to the light curves of the classical FUors - FU Ori and V1057 Cyg. The spectral observations during the time of increase in brightness showed significant changes in both the profiles and intensity of the spectral lines. Only Hα remained in

  14. Characterization of a lymphoblastoid line deleted for lambda immunoglobulin genes

    SciTech Connect

    Hough, C.A., White, B.N., Holden, J.A.

    1995-04-01

    While characterizing the cat eye syndrome (CES) supernumerary chromosome for the presence of {lambda} immunoglobulin gene region sequences, a lymphoblastoid cell line from one CES patient was identified in which there was selection of cells deleted from some IGLC and IGLV genes. Two distinct deletions, one on each chromosome 22, were identified, presumably arising from independent somatic recombination events occurring during B-lymphocyte differentiation. The extent of the deleted regions was determined using probes from the various IGLV subgroups and they each covered at least 82 kilobases. The precise definition of the deletions was not possible because of conservation of some restriction sites in the IGLV region. The cell line was used to map putative IGLV genes within the recombinant phage {lambda}V{lambda}135 to the distal part of the IGLV gene region. 35 refs., 4 figs.

  15. Prediction of narrow N* and {Lambda}* with hidden charm

    SciTech Connect

    Wu Jiajun; Molina, R.; Oset, E.; Zou, B. S.

    2011-10-24

    The interaction between various charmed mesons and charmed baryons, such as D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled channel unitary approach with the local hidden gauge formalism. Six narrow N* and {Lambda}* resonances are dynamically generated with mass above 4 GeV and width smaller than 100 MeV. These predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks. We make estimates of production cross sections of these predicted resonances in p-barp collisions for PANDA at the forthcoming FAIR facility.

  16. Persistence behaviour of thiamethoxam and lambda cyhalothrin in transplanted paddy.

    PubMed

    Barik, Suhrid Ranjan; Ganguly, Pritam; Kunda, Samir Kumar; Kole, Ramen Kumar; Bhattacharyya, Anjan

    2010-10-01

    A field study was conducted in Pre-Kharif season 2007 on paddy to determine the persistence of thiamethoxam (12.6%) and lambda cyhalothrin (9.4%) [in a 'Readymix' formulation Alika 247 ZC], following the application of 33 g. a.i. ha⁻¹ (T₁) and 66 g. a.i. ha⁻¹ (T₂). Spraying of insecticide was done during milking stage of the crop (63 days after transplantation). Thiamethoxam and lambda cyhalothrin residues were estimated by HPLC and GLC respectively. The half-life values were 5.2-5.8 and 4.8 days for thiamethoxam and lambda cyhalothrin respectively. No residue was detected in the harvested paddy, straw, grain, and soil samples.

  17. Observational constraints on late-time {lambda}(t) cosmology

    SciTech Connect

    Carneiro, S.; Pigozzo, C.; Dantas, M. A.; Alcaniz, J. S.

    2008-04-15

    The cosmological constant {lambda}, i.e., the energy density stored in the true vacuum state of all existing fields in the Universe, is the simplest and the most natural possibility to describe the current cosmic acceleration. However, despite its observational successes, such a possibility exacerbates the well-known {lambda} problem, requiring a natural explanation for its small, but nonzero, value. In this paper we study cosmological consequences of a scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, {lambda}{proportional_to}H. We test the viability of this scenario and study a possible way to distinguish it from the current standard cosmological model by using recent observations of type Ia supernova (Supernova Legacy Survey Collaboration), measurements of the baryonic acoustic oscillation from the Sloan Digital Sky Survey, and the position of the first peak of the cosmic microwave background angular spectrum from the three-year Wilkinson Microwave Anisotropy Probe.

  18. Measurement of Lambda and Lambda(macro) particles in Au+Au collisions at the square root of S(NN) = 130 GeV.

    PubMed

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; el-Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H-A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kotchetkov, D; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Pal, D; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; Van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S; Zhou, S

    2002-08-26

    We present results on the measurement of Lambda and Lambda(macro) production in Au+Au collisions at square root of (S (NN) = 130 GeV with the PHENIX detector at the Relativistic Heavy Ion Collider. The transverse momentum spectra were measured for minimum bias and for the 5% most central events. The Lambda;/Lambda ratios are constant as a function of p(T) and the number of participants. The measured net Lambda density is significantly larger than predicted by models based on hadronic strings (e.g., HIJING) but in approximate agreement with models which include the gluon-junction mechanism.

  19. Midrapidity Lambda and Lambda(macro) production in Au+Au collisions at the square root of [s(NN)]=130 GeV.

    PubMed

    Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Deng, W S; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; de Toledo, A Szanto; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

    2002-08-26

    We report the first measurement of strange (Lambda) and antistrange (Lambda macro) baryon production from square root of [s(NN)]=130 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Rapidity density and transverse mass distributions at midrapidity are presented as a function of centrality. The yield of Lambda and Lambda; hyperons is found to be approximately proportional to the number of negative hadrons. The production of Lambda; hyperons relative to negative hadrons increases very rapidly with transverse momentum. The magnitude of the increase cannot be described by existing hadronic string fragmentation models alone.

  20. The algebraic theory of latent projectors in lambda matrices

    NASA Technical Reports Server (NTRS)

    Denman, E. D.; Leyva-Ramos, J.; Jeon, G. J.

    1981-01-01

    Multivariable systems such as a finite-element model of vibrating structures, control systems, and large-scale systems are often formulated in terms of differential equations which give rise to lambda matrices. The present investigation is concerned with the formulation of the algebraic theory of lambda matrices and the relationship of latent roots, latent vectors, and latent projectors to the eigenvalues, eigenvectors, and eigenprojectors of the companion form. The chain rule for latent projectors and eigenprojectors for the repeated latent root or eigenvalues is given.

  1. Properties of the Lambda(1670)(1-)/2 resonance.

    PubMed

    Manley, D M; Abaev, V V; Allgower, C E; Bekrenev, V; Briscoe, W J; Clajus, M; Comfort, J R; Craig, K; Grosnick, D; Isenhower, D; Knecht, N; Koetke, D D; Kulbardis, A A; Kozlenko, N G; Kruglov, S; Lolos, G; Lopatin, I V; Manweiler, R; Marusić, A; McDonald, S; Nefkens, B M K; Olmsted, J; Papandreou, Z; Peaslee, D C; Phaisangittisakul, N; Prakhov, S; Price, J W; Ramirez, A F; Sadler, M; Shafi, A; Spinka, H; Stanislaus, T D S; Starostin, A; Staudenmaier, H M; Strakovsky, I I; Supek, I; Tippens, W B

    2002-01-07

    Recently the Crystal Ball Collaboration measured precise new data for the near-threshold reaction K(-)p-->etaLambda, which is dominated by formation of the Lambda(1670)1 / 2(-). In this Letter, we present results of a unitary, multichannel analysis that incorporates the new Crystal Ball data. For our preferred fit, we obtain mass M = 1673+/-2 MeV, width Gamma = 23+/-6 MeV, and elasticity x = 0.37+/-0.07. This elasticity is significantly larger than previously recognized. Resonance parameters of our preferred fit are in striking agreement with the quark-model predictions of Koniuk and Isgur.

  2. Observation of. lambda. -hypernuclei in the reaction /sup 12/C(. pi. /sup +/,K/sup +/)/sub. lambda. //sup 12/C

    SciTech Connect

    Milner, E.C.

    1985-12-01

    The observation of ..lambda..-hypernuclear levels in /sub ..lambda..//sup 12/C by associated production through the (..pi../sup +/,K/sup +/) reaction is reported. Spectrometers used in the measurements are discussed. The /sub ..lambda..//sup 12/C excitation energy spectra were recorded at laboratory scattering angles of 5.6/sup 0/, 10.3/sup 0/, and 15.2/sup 0/. The spectra show two major peaks - one attributed to the ground state, and one about 11 MeV higher in excitation. The peak near 11 MeV excitation energy is believed to be almost entirely composed of a multiplet of three J/sup ..pi../ = 2/sup +/ states. Relativistic DWBA calculations imply support for the expectation that higher spin states are preferentially populated in the (..pi../sup +/,K/sup +/) reaction, compared to the (K/sup -/,..pi../sup -/) reaction in which lower spin states are excited. 29 refs., 40 figs.

  3. X-Ray Flare Characteristics in lambda Eridani

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.

    1997-01-01

    This proposal was for a joint X-ray/ultraviolet/ground-based study of the abnormal Be star lambda Eri, which has previously shown evidence of X-ray flaring from ROSAT observations in 1991. The X-ray component consisted of observations from both the ASCA and ROSAT satellites.

  4. X-Ray Flare Characteristics in Lambda Eridani

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.

    1997-01-01

    This proposal was for a joint X-ray/ultraviolet/ground-based study of the abnormal Be star lambda Eri, which has previously shown evidence of X-ray flaring from ROSAT observations in 1991. The X-ray component consisted of observations from both the ASCA and ROSAT satellites.

  5. Organization, complexity and allelic diversity of the porcine (Sus scrofa domestica) immunoglobulin lambda locus.

    PubMed

    Schwartz, John C; Lefranc, Marie-Paule; Murtaugh, Michael P

    2012-05-01

    We have characterized the organization, complexity, and expression of the porcine (Sus scrofa domestica) immunoglobulin lambda (IGL) light chain locus, which accounts for about half of antibody light chain usage in swine, yet is nearly totally unknown. Twenty-two IGL variable (IGLV) genes were identified that belong to seven subgroups. Nine genes appear to be functional. Eight possess stop codons, frameshifts, or both, and one is missing the V-EXON. Two additional genes are missing an essential cysteine residue and are classified as ORF (open reading frame). The IGLV genes are organized in two distinct clusters, a constant (C)-proximal cluster dominated by genes similar to the human IGLV3 subgroup, and a C-distal cluster dominated by genes most similar to the human IGLV8 and IGLV5 subgroups. Phylogenetic analysis reveals that the porcine IGLV8 subgroup genes have recently expanded, suggesting a particularly effective role in immunity to porcine-specific pathogens. Moreover, expression of IGLV genes is nearly exclusively restricted to the IGLV3 and IGLV8 genes. The constant locus comprises three tandem cassettes comprised of a joining (IGLJ) gene and a constant (IGLC) gene, whereas a fourth downstream IGLJ gene has no corresponding associated IGLC gene. Comparison of individual BACs generated from the same individual revealed polymorphisms in IGLC2 and several IGLV genes, indicating that allelic variation in IGLV further expands the porcine antibody light chain repertoire.

  6. Approaches for the direct estimation of lambda, and demographic contributions to lambda, using capture-recapture data

    USGS Publications Warehouse

    Nichols, J.D.; Hines, J.E.

    2002-01-01

    We first consider the estimation of the finite rate of population increase or population growth rate, lambda sub i, using capture-recapture data from open populations. We review estimation and modelling of lambda sub i under three main approaches to modelling open-population data: the classic approach of Jolly (1965) and Seber (1965), the superpopulation approach of Crosbie & Manly (1985) and Schwarz & Arnason (1996), and the temporal symmetry approach of Pradel (1996). Next, we consider the contributions of different demographic components to lambda sub i using a probabilistic approach based on the composition of the population at time i + 1 (Nichols et al., 2000b). The parameters of interest are identical to the seniority parameters, gamma sub i, of Pradel (1996). We review estimation of gamma sub i under the classic, superpopulation, and temporal symmetry approaches. We then compare these direct estimation approaches for lambda sub i and gamma sub i with analogues computed using projection matrix asymptotics. We also discuss various extensions of the estimation approaches to multistate applications and to joint likelihoods involving multiple data types.

  7. Cluster Headache

    MedlinePlus

    Cluster headache Overview By Mayo Clinic Staff Cluster headaches, which occur in cyclical patterns or clusters, are one of the most painful types of headache. A cluster headache commonly awakens you ...

  8. {lambda}{sup 0} Polarization in pp{yields}p{lambda}{sup 0}K{sup +} at 800 GeV/c

    SciTech Connect

    Valencia, E.; Felix, J.; Reyes, M. A.; Wang, M. H. L. S.; Berisso, M. C.; Kreisler, M. N.; Lee, S.; Markianos, K.; Wesson, D.; Christian, D. C.; Gottschalk, E.; Gutierrez, G.; Wehmann, A.; Gara, A.; Knapp, B. C.; Hartouni, E. P.

    2008-07-02

    We determined {lambda}{sup 0} polarization as function of X{sub F}, P{sub T}, M{sub X}, and E{sub {lambda}}, with respect to the normal of the following two different production planes: The first one defined by the momentum of the 800 GeV/c proton beam and the moment of {lambda}{sup 0}; the second one, by the momentum of the transferred object and the momentum of {lambda}{sup 0}, from the sample created in the FNAL E690 experiment. We present results, compare and discuss them.

  9. The lambda-scheme method applied to Stirling engines

    NASA Astrophysics Data System (ADS)

    Franco, R.

    1985-12-01

    An integration method of the motion equations is the so-called 'lambda-scheme': such a method suggests that, in the numerical procedure of the approximation of the derivatives in space with finite differences, the physical domains of dependence have to be correctly taken into account, according to the wave propagation through the flow. In the lambda-scheme method, the codes are simple, the computing time is kept very low, while accuracy (second-order in space and time) of the results is very satisfactory. As a matter of fact, the simulation model here discussed leads to a deeper analysis and a closer prediction of Stirling engine performances. As a first approach, a feasibility analysis is carried out for an expansion space-heat exchanger flow duty simulation.

  10. Efficient epitope mapping by bacteriophage {lambda} surface display

    SciTech Connect

    Kuwabara, I.; Maruyama, H.; Zuberi, R.I.

    1997-01-01

    A bacteriophage {lambda} surface expression system, {lambda}foo, was used for epitope mapping of human galectin-3. We constructed random epitope and peptide libraries and compared their efficiencies in the mapping. The galectin-3 cDNA was randomly digested by DNase I to make random epitope libraries. The libraries were screened by affinity selection using a microtiter plate coated with monoclonal antibodies. Direct DNA sequencing of the selected clones defined two distinct epitope sites consisting of nine and 11 amino-acid residues. Affinity selection of random peptide libraries recovered a number of sequences that were similar to each other but distinct from the galectin-3 sequence. These results demonstrate that a single affinity selection of epitope libraries with antibodies is able to define an epitope determinant as small as nine residues long and is more efficient in epitope mapping than random peptide libraries. 25 refs., 4 figs., 1 tab.

  11. Optical-SZE Scaling Relations for DES Optically Selected Clusters within the SPT-SZ Survey

    SciTech Connect

    Saro, A.; et al.

    2016-05-27

    We study the Sunyaev-Zel'dovich effect (SZE) signature in South Pole Telescope (SPT) data for an ensemble of 719 optically identified galaxy clusters selected from 124.6 deg$^2$ of the Dark Energy Survey (DES) science verification data, detecting a stacked SZE signal down to richness $\\lambda\\sim20$. The SZE signature is measured using matched-filtered maps of the 2500 deg$^2$ SPT-SZ survey at the positions of the DES clusters, and the degeneracy between SZE observable and matched-filter size is broken by adopting as priors SZE and optical mass-observable relations that are either calibrated using SPT selected clusters or through the Arnaud et al. (2010, A10) X-ray analysis. We measure the SPT signal to noise $\\zeta$-$\\lambda$, relation and two integrated Compton-$y$ $Y_\\textrm{500}$-$\\lambda$ relations for the DES-selected clusters and compare these to model expectations accounting for the SZE-optical center offset distribution. For clusters with $\\lambda > 80$, the two SPT calibrated scaling relations are consistent with the measurements, while for the A10-calibrated relation the measured SZE signal is smaller by a factor of $0.61 \\pm 0.12$ compared to the prediction. For clusters at $20 < \\lambda < 80$, the measured SZE signal is smaller by a factor of $\\sim$0.20-0.80 (between 2.3 and 10~$\\sigma$ significance) compared to the prediction, with the SPT calibrated scaling relations and larger $\\lambda$ clusters showing generally better agreement. We quantify the required corrections to achieve consistency, showing that there is a richness dependent bias that can be explained by some combination of contamination of the observables and biases in the estimated masses. We discuss possible physical effects, as contamination from line-of-sight projections or from point sources, larger offsets in the SZE-optical centering or larger scatter in the $\\lambda$-mass relation at lower richnesses.

  12. Characterization of SAL605 negative resist at {lambda}=13 nm

    SciTech Connect

    La Fontaine, B.; Ciarlo, D.; Gaines, D.P.; Kania, D.R.

    1996-05-24

    We have characterized the response of the negative resist SAL605 in the extreme ultraviolet ({lambda}=13 nm). The sensitivity was found to be {approx}1 mJ/cm{sup 3} for all conditions studied. We have identified processing conditions leading to high ({gamma}{gt}4) contrast. The resist response was modeled using Prolith/2 and the development parameters were obtained from the exposure curves.

  13. Lambda modes of the neutron diffusion equation in hexagonal geometry

    SciTech Connect

    Barrachina, T.; Ginestar, D.; Verdu, G.

    2006-07-01

    A nodal collocation method is proposed to compute the dominant Lambda modes of nuclear reactor core with a hexagonal geometry. This method is based on a triangular mesh and assumes that the neutronic flux can be approximated as a finite expansion in terms of Dubiner's polynomials. The method transforms the initial differential eigenvalue problem into a generalized algebraic one, from which the dominant modes of the reactor can be computed. The performance of the method is tested with two benchmark problems. (authors)

  14. An investigation of the {anti p}p {yields} {anti {Lambda}} {Lambda} and {anti p}p {yields} {anti {Sigma}}{sup 0} {Lambda} + c.c. reactions near threshold

    SciTech Connect

    Tayloe, R.; PS185 Collaboration

    1995-12-31

    Experiment PS 185 studies the production of antihyperon-hyperon pairs in antiproton-proton collisions at LEAR in the near-threshold energy region. The {ital {anti p} p} {r_arrow} {anti {Lambda}}{Lambda} reaction has been thoroughly studied by PS185 and many high-quality data have been reported. New results, including total and differential cross sections along with spin observables, are presented here for the channels {ital {anti p} p} {r_arrow} {anti {Lambda}}{Lambda} and {ital {anti p}p} {r_arrow} {anti {Sigma}}{sup 0}{Lambda} + c.c at incident lab antiproton momenta of 1.726 and 1. 771 GeV/c. The data from the relatively unstudied and complementary {ital {anti p}p} {r_arrow} {anti {Sigma}}{sup 0}{Lambda} + c.c channel is compared to that from {ital {anti p}p} {r_arrow} {anti {Lambda}}{Lambda} at similar energies above the reaction threshold.

  15. Measurement of sigma Lambda b0/sigma B0 x B(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-) in pp collisions at square root s=1.96 TeV.

    PubMed

    Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; DaRonco, S; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Le, Y; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tseng, J; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-03-23

    We present the first observation of the baryon decay Lambda b0-->Lambda c+pi- followed by Lambda c+-->pK-pi+ in 106 pb-1 pp collisions at square root s=1.96 TeV in the CDF experiment. In order to reduce systematic error, the measured rate for Lambda b0 decay is normalized to the kinematically similar meson decay B0-->D+pi- followed by D+-->pi+K-pi+. We report the ratio of production cross sections (sigma) times the ratio of branching fractions (B) for the momentum region integrated above pT>6 GeV/c and pseudorapidity range |eta|<1.3: sigma(pp-->Lambda b0X)/sigma(pp-->B0X)xB(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-)=0.82+/-0.08(stat)+/-0.11(syst)+/-0.22[B(Lambda c+-->pK-pi+)].

  16. ({lambda}, p) Spectrum Analysis in p+A Interactions at 10 GeV/c

    SciTech Connect

    Aslanyan, P. Zh.; Emelyanenko, V. N.

    2007-06-13

    Experimental data from the 2m propane bubble chamber have been analyzed for exotic baryon states search. A number of peculiarities were found in the effective mass spectra of: {lambda}{pi}+({sigma}*+(1382),PDG), {lambda}p and {lambda}pp subsystems. A few events detected on the photographs of the propane bubble chamber exposed to a 10 GeV/c proton beam, were interpreted as S=-2 H0 light(lambda}{lambda})) and heavy H0,+. New event, detected on the photographs of the propane bubble chamber was interpreted as heavy H+(2488) dibaryon by two weak decay channels of K-pp or {sigma}+p{pi}-.

  17. Measurement of the Lambda0(b) Lifetime in Lambda0(b) ---> J/psi Lambda0 in p anti-p Collisions at s**(1/2) = 1.96-TeV

    SciTech Connect

    Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

    2006-09-01

    The authors report a measurement of the {Lambda}{sub b}{sup 0} lifetime in the exclusive decay {Lambda}{sub b}{sup 0} {yields} J/{psi}{Lambda}{sup 0} in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 1.0 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, they measure {tau}({Lambda}{sub b}{sup 0}) = 1.593{sub -0.078}{sup +0.083}(stat.) {+-} 0.033(syst.) ps. This is the single most precise measurement of {tau}({Lambda}{sub b}{sup 0}) and is 3.2 {sigma} higher than the current world average.

  18. Study of inclusive. Lambda. production in e sup + e minus annihilations at 29 GeV

    SciTech Connect

    Geld, T.L.; Neal, H.; Akerlof, C.; Chapman, J.; Errede, D.; Ken, M.T.; Kesten, P.; Meyer, D.I.; Nitz, D.; Thun, R.; Tschirhart, R. ); Abachi, S.; Derrick, M.; Kooijman, P.; Musgrave, B.; Price, L.; Repond, J.; Sugano, K. ); Blockus, D.; Brabson, B.B.; Brom, J.; Jung, C.; Ogren, H.; Rust, D.R.; Snyder, A. ); Cork, B. ); Baringer, P.; Bylsma, B.G.; Debonte, R.; Low, E.H.; McIlwain, R.L.; Miller, D.H.; Ng, C.R.; Rangan, K.; Shibata, E. )

    1992-06-01

    Cross sections are presented for the inclusive production of {Lambda} hyperons in electron-positron annihilations at {radical}{ital s} =29 GeV based on the full 291-pb{sup {minus}1} sample of data taken in the High Resolution Spectrometer experiment at the SLAC {ital e}{sup +}{ital e}{minus} storage ring PEP. These results, and the associated correlation analyses, are consistent with the Lund model predictions with the strange diquark suppression ratio {delta} fixed at 0.59{plus minus}0.10{plus minus}0.18, as compared to the standard Lund value of 0.32. The {Lambda} multiplicity has been found to be 0.182{plus minus}0.020 per event. The opposite-strangeness multiplicity {l angle}{ital n}{sub {Lambda}}{Lambda}{bar a}{r angle} has been measured to be 0.046{plus minus}0.020, whereas the like-strangeness multiplicity {l angle}{ital n}{sub {Lambda}{Lambda}}+{bar {Lambda}}{bar {Lambda}}{r angle} is 0.009{plus minus}0.028. A strong correlation is found between {Lambda}'s and {bar {Lambda}} 's; when one is found in an event, the other is found in the same event with a probability that exceeds 50%.

  19. The role of template superhelicity in the initiation of bacteriophage lambda DNA replication.

    PubMed Central

    Alfano, C; McMacken, R

    1988-01-01

    The prepriming steps in the initiation of bacteriophage lambda DNA replication depend on the action of the lambda O and P proteins and on the DnaB helicase, single-stranded DNA binding protein (SSB), and DnaJ and DnaK heat shock proteins of the E. coli host. The binding of multiple copies of the lambda O protein to the phage replication origin (ori lambda) initiates the ordered assembly of a series of nucleoprotein structures that form at ori lambda prior to DNA unwinding, priming and DNA synthesis steps. Since the initiation of lambda DNA replication is known to occur only on supercoiled templates in vivo and in vitro, we examined how the early steps in lambda DNA replication are influenced by superhelical tension. All initiation complexes formed prior to helicase-mediated DNA-unwinding form with high efficiency on relaxed ori lambda DNA. Nonetheless, the DNA templates in these structures must be negatively supertwisted before they can be replicated. Once DNA helicase unwinding is initiated at ori lambda, however, later steps in lambda DNA replication proceed efficiently in the absence of superhelical tension. We conclude that supercoiling is required during the initiation of lambda DNA replication to facilitate entry of a DNA helicase, presumably the DnaB protein, between the DNA strands. Images PMID:2847118

  20. Search for CP violation in charged-Xi and Lambda hyperon decays

    SciTech Connect

    Holmstrom, T.; Leros, N.; Burnstein, R.A.; Chakravorty, A.; Chan, A.; Chen, Y.C.; Choong, W.S.; Clark, K.; Dukes, E.C.; Durandet, C.; Felix, J.; Fu, Y.; Gidal, G.; Gu, P.; Gustafson, H.R.; Ho, C.; Huang, M.; James, C.; Jenkins, C.M.; Jones, T.; Kaplan, D.M.; /Virginia U. /Lausanne U. /Taiwan, Inst. Phys. /UC, Berkeley /Fermilab /Guanajuato U. /IIT, Chicago /Lausanne U. /LBL, Berkeley /Michigan U. /South Alabama U. /Virginia U.

    2004-12-01

    The authors have compared the p and {bar p} angular distributions in 117 million {Xi}{sup -} {yields} {Lambda}{pi}{sup -} {yields} p{pi}{sup -}{pi}{sup -} and 41 million {Xi}{sup +} {yields} {bar {Lambda}}{pi}{sup +} {yields} {bar p}{pi}{sup +}{pi}{sup +} decays using a subset of the data from the HyperCP experiment (ES71) at Fermilab. They find no evidence of CP violation, with the direct-CP-violating parameter A{sub {Xi}{Lambda}} {triple_bond} (a{sub {Xi}}a{sub {Lambda}} - {bar a}{sub {Xi}}{bar a}{sub {Lambda}})/(a{sub {Xi}}a{sub {Lambda}} + {bar a}{sub {Xi}}{bar a}{sub {Lambda}}) = [0.0 {+-} 5.1(stat) {+-} 4.4(syst)] x 10{sup -4}.

  1. Confronting dark energy models using galaxy cluster number counts

    SciTech Connect

    Basilakos, S.; Plionis, M.; Lima, J. A. S.

    2010-10-15

    The mass function of cluster-size halos and their redshift distribution are computed for 12 distinct accelerating cosmological scenarios and confronted to the predictions of the conventional flat {Lambda}CDM model. The comparison with {Lambda}CDM is performed by a two-step process. First, we determine the free parameters of all models through a joint analysis involving the latest cosmological data, using supernovae type Ia, the cosmic microwave background shift parameter, and baryon acoustic oscillations. Apart from a braneworld inspired cosmology, it is found that the derived Hubble relation of the remaining models reproduces the {Lambda}CDM results approximately with the same degree of statistical confidence. Second, in order to attempt to distinguish the different dark energy models from the expectations of {Lambda}CDM, we analyze the predicted cluster-size halo redshift distribution on the basis of two future cluster surveys: (i) an X-ray survey based on the eROSITA satellite, and (ii) a Sunayev-Zeldovich survey based on the South Pole Telescope. As a result, we find that the predictions of 8 out of 12 dark energy models can be clearly distinguished from the {Lambda}CDM cosmology, while the predictions of 4 models are statistically equivalent to those of the {Lambda}CDM model, as far as the expected cluster mass function and redshift distribution are concerned. The present analysis suggests that such a technique appears to be very competitive to independent tests probing the late time evolution of the Universe and the associated dark energy effects.

  2. Utilizing Synthetic Spectra to Refine Lambda Boo Stars' UV Classification Criteria

    NASA Astrophysics Data System (ADS)

    Cheng, Kwang-Ping; Neff, James E.; Johnson, Dustin; Tarbell, Erik; Romo, Christopher; Steele, Patricia; Gray, Richard O.; Corbally, Christopher J.

    2016-01-01

    Lambda Boo-type stars are a group of late B to early F-type Population I dwarfs that show deficiencies of iron-peak elements (up to 2 dex), but their C, N, O, and S abundances are near solar. This stellar class has recently regained the spotlight because of the directly-imaged planets around a confirmed Lambda Boo star, HR 8799, and a suggested Lambda Boo star Beta Pictoris. The discovery of a giant asteroid belt around Vega, another possible Lambda Boo star, also suggests hidden planets. This possible link between Lambda Boo stars and planet-bearing stars motivates us to study Lambda Boo stars systematically. Since the peculiar nature of the prototype Lambda Bootis was first noticed in 1943, Lambda Boo candidates published in the literature have been selected using widely different criteria. The Lambda Boo label has been applied to almost any peculiar A-type stars that do not fit elsewhere. In order to determine the origin of Lambda Boo stars' unique abundance pattern and to better discriminate between theories explaining the Lambda Boo phenomenon, a consistent working definition of Lambda Boo stars is needed. We have re-evaluated all published Lambda Boo candidates and their available ultraviolet and visible spectra. Using observed and synthetic spectra, we explored the classification of Lambda Boo stars and developed quantitative criteria that discriminate metal-poor stars from bona fide Lambda Boo stars. With model spectra, we demonstrated that the (C I 1657 Angstrom)/ (Al II 1671 Angstrom) line ratio is the best single criterion to distinguish between Lambda Boo stars and metal weak stars, and that one cannot use a single C I/Al II cut-off value as a Lambda Boo classification criterion. The C I/Al II cut-off value is a function of a star's effective temperature and metallicity. Using these stricter Lambda Boo classification criteria, we concluded that neither Beta Pictoris nor Vega should be classified as Lambda Boo stars.

  3. Lambda Hyperon and Anti-Lambda Hyperon Production in Proton-Antiproton Collisions at SQRT.S = 1.8 Tev

    NASA Astrophysics Data System (ADS)

    Wesson, Dennis Keith

    1990-01-01

    The characteristics of Lambda and |Lambda production have been studied from data obtained from p p collisions at sqrt{rm s} = 1.8 TeV during the first running period of experiment E735 from January to May of 1987. The experiment was conducted at the Fermi National Laboratory Tevatron collider. Five million triggers from an integrated luminosity of about 1over 3 nb^{ -1} were written to tape during this initial run of E735. Using a magnetic spectrometer arm a sample of 413 Lambda's + = Lambda's were found in these events. The transverse momentum spectrum, the ratio Lambda/(all charged particles) and the ratio Lambda/proton were studied from this sample. These were compared to the findings at lower energies and also to the results of a Monte Carlo program from another experiment. The average transverse momentum was found to be 0.77 +/- 0.06 +/- 0.08, an increase of about 24% from the value found at sqrt{rm s} = 540 GeV (CERN SPS) and an increase of about 55% from sqrt{rm s} = 53 GeV (CERN ISR). The Lambda/(all charged particle) ratio was also found to increase from 0.009 +/- 0.001 at sqrt{rm s} = 53 GeV (CERN ISR) and 0.019 +/- 0.004 at sqrt{rm s} = 540 GeV (CERN SPS), to 0.026 +/- 0.002 +/- 0.004 at our energy of sqrt{rm s} = 1.8 TeV. The lambda/proton ratio was found to be 0.38 +/- 0.03 +/- 0.06. This ratio shows no increase from lower energies. The lambda/proton ratio was used to find the strangeness suppression factor (lambda) from the quark combinatoric model of hadron production. We obtain a value lambda = 0.34 +/- 0.05 in agreement with the values found at lower energies. The increase in the ratio lambda/all charged particles as a function of center of mass energy is not inconsistent with the formation of quark-gluon plasma. However, the constant ratio of lambda/proton production is not expected in quark-gluon plasma production. Moreover, our data seem to agree with the UA5 Monte Carlo data, which does not include quark-gluon plasma production. Based on Lambda

  4. Longitudinal Spin Transfer to Lambda and Anti-Lambda Hyperons Produced in Polarized Proton-Proton Collisions at Center of Mass Energy = 200 GeV

    NASA Astrophysics Data System (ADS)

    Cendejas, Ramon

    Studies on the spin structure of the proton have been an active area of research; after the EMC experiment and subsequent experiments found that only about 30% of the total proton spin is carried by quark spins. The Relativistic Heavy Ion Collider (RHIC) is the world's first and only polarized proton collider. The Solenoidal Tracker At RHIC (STAR) has full azimuthal acceptance and is ideally suited to advance studies of the proton spin. The longitudinal spin transfer, DLL, of lambda and anti-lambda hyperons in longitudinally polarized proton-proton collisions is sensitive to quark and anti-quark polarization in the polarized proton; as well as to polarized fragmentation; and has been proposed as a possible probe of (anti-)strange quark polarization. The STAR collaboration has previously reported an initial proof-of-concept measurement of DLL of lambda and anti-lambda hyperons from a data sample obtained at sqr(s)=200 GeV in 2005. The data correspond to an integrated luminosity of 2 pb- with 50% beam polarization. Considerably larger data samples corresponding to 6.5 pb- and 25 pb- with beam polarizations of 57% at sqr(s)=200 GeV were obtained in 2006 and 2009 using an upgraded instrument. Improvements were made on the analysis procedure to reduce background contribution to the lambda + anti-lambda measurements. These new measurements of DLL form the main topic of this dissertation. The sample of hyperons residing within a jet that triggered the experiment are classified as near-side hyperons, and are analyzed separately from an away-side sample that has similar precision. In addition to DLL, the double longitudinal spin asymmetry, A LL, for the production of lambda and anti-lambda hyperons has been extracted. The dependences of DLL on pseudo-rapidity, pT , and the fragmentation ratio, z, are studied. The stated DLL from lambda and anti-lambda each disfavor one of the published model predictions for DLL for a combined lambda and anti-lambda sample, and are

  5. UTILIZING SYNTHETIC UV SPECTRA TO EXPLORE THE PHYSICAL BASIS FOR THE CLASSIFICATION OF LAMBDA BOÖTIS STARS

    SciTech Connect

    Cheng, Kwang-Ping; Johnson, Dustin M.; Tarbell, Erik S.; Romo, Christopher A.; Prabhaker, Arvind; Neff, James E.; Steele, Patricia A.; Gray, Richard O.; Corbally, Christopher J.

    2016-04-15

    Lambda Boo-type stars are a group of late B to early F-type Population I dwarfs that show mild to extreme deficiencies of iron-peak elements (up to 2 dex), but their C, N, O, and S abundances are near solar. This intriguing stellar class has recently regained the spotlight because of the directly imaged planets around a confirmed Lambda Boo star, HR 8799, and a suggested Lambda Boo star, Beta Pictoris. The discovery of a giant asteroid belt around Vega, another possible Lambda Boo star, also suggests hidden planets. The possible link between Lambda Boo stars and planet-bearing stars motivates us to study Lambda Boo stars systematically. Since the peculiar nature of the prototype Lambda Boötis was first noticed in 1943, Lambda Boo candidates published in the literature have been selected using widely different criteria. In order to determine the origin of Lambda Boo stars’ unique abundance pattern and to better discriminate between theories explaining the Lambda Boo phenomenon, a consistent working definition of Lambda Boo stars is needed. We have re-evaluated all published Lambda Boo candidates and their available ultraviolet and visible spectra. In this paper, using observed and synthetic spectra, we explore the physical basis for the classification of Lambda Boo stars, and develop quantitative criteria that discriminate metal-poor stars from bona fide Lambda Boo stars. Based on these stricter Lambda Boo classification criteria, we conclude that neither Beta Pictoris nor Vega should be classified as Lambda Boo stars.

  6. Utilizing Synthetic UV Spectra to Explore the Physical Basis for the Classification of Lambda Boötis Stars

    NASA Astrophysics Data System (ADS)

    Cheng, Kwang-Ping; Neff, James E.; Johnson, Dustin M.; Tarbell, Erik S.; Romo, Christopher A.; Prabhaker, Arvind; Steele, Patricia A.; Gray, Richard O.; Corbally, Christopher J.

    2016-04-01

    Lambda Boo-type stars are a group of late B to early F-type Population I dwarfs that show mild to extreme deficiencies of iron-peak elements (up to 2 dex), but their C, N, O, and S abundances are near solar. This intriguing stellar class has recently regained the spotlight because of the directly imaged planets around a confirmed Lambda Boo star, HR 8799, and a suggested Lambda Boo star, Beta Pictoris. The discovery of a giant asteroid belt around Vega, another possible Lambda Boo star, also suggests hidden planets. The possible link between Lambda Boo stars and planet-bearing stars motivates us to study Lambda Boo stars systematically. Since the peculiar nature of the prototype Lambda Boötis was first noticed in 1943, Lambda Boo candidates published in the literature have been selected using widely different criteria. In order to determine the origin of Lambda Boo stars’ unique abundance pattern and to better discriminate between theories explaining the Lambda Boo phenomenon, a consistent working definition of Lambda Boo stars is needed. We have re-evaluated all published Lambda Boo candidates and their available ultraviolet and visible spectra. In this paper, using observed and synthetic spectra, we explore the physical basis for the classification of Lambda Boo stars, and develop quantitative criteria that discriminate metal-poor stars from bona fide Lambda Boo stars. Based on these stricter Lambda Boo classification criteria, we conclude that neither Beta Pictoris nor Vega should be classified as Lambda Boo stars.

  7. Lambda bacteriophage-mediated transduction of ColE1 deoxyribonucleic acid having a lambda bacteriophage-cohesive end site: selection of packageable-length deoxyribonucleic acid.

    PubMed Central

    Umene, K; Shimada, K; Tsuzuki, T; Mori, R; Takagi, Y

    1979-01-01

    An in vitro recombinant ColE1-cos lambda deoxyribonucleic acid (DNA) molecule, pKY96, has 70% of the length of lambda phage DNA. The process of lambda phage-mediated transduction of pKY96 generated a small amount of transducing phage particles containing ColE1-cos lambda DNA molecules of 80 or 101% of the length of lambda phage DNA, in addition to those containing original pKY96 DNA molecules. The newly isolated larger plasmid DNAs were transduced 100 times more efficiently than pKY96 DNA. Their structures were compared with that of a prototype pKY96 DNA, and the mechanism of the formation of these molecules is discussed. Images PMID:158007

  8. CLUSTER CHEMISTRY

    SciTech Connect

    Muetterties, Earl L.

    1980-05-01

    Metal cluster chemistry is one of the most rapidly developing areas of inorganic and organometallic chemistry. Prior to 1960 only a few metal clusters were well characterized. However, shortly after the early development of boron cluster chemistry, the field of metal cluster chemistry began to grow at a very rapid rate and a structural and a qualitative theoretical understanding of clusters came quickly. Analyzed here is the chemistry and the general significance of clusters with particular emphasis on the cluster research within my group. The importance of coordinately unsaturated, very reactive metal clusters is the major subject of discussion.

  9. The cluster distribution as a test of dark matter models - I. Clustering properties

    NASA Astrophysics Data System (ADS)

    Borgani, Stefano; Plionis, Manolis; Coles, Peter; Moscardini, Lauro

    1995-12-01

    We present extended simulations of the large-scale distribution of galaxy clusters in several dark matter models, using an optimized version of the truncated Zel'dovich approximation (TZA). In order to test the reliability of our simulations, we compare them with N-body-based cluster simulations. We find that the TZA provides a very accurate description of the cluster distribution as long as fluctuations on the cluster mass-scale are in the mildly non-linear regime (sigma_8<~1). The low computational cost of this simulation technique allows us to run a large ensemble of 50 realizations for each model, so we are able to quantify accurately the effects of cosmic variance. Six different dark matter models are studied in this work: standard CDM (SCDM), tilted CDM (TCDM) with primordial spectral index n=0.7, cold+hot DM (CHDM) with Omega_hot=0.3, low Hubble constant (h=0.3) CDM (LOWH), and two spatially flat low-density CDM models with Omega_0=0.2 and Omega_Lambda=0.8, having two different normalizations, sigma_8=0.8 (LambdaCDM_1) and sigma_8=1.3 (LambdaCDM_2). We compare the cluster simulations with an extended redshift sample of Abell/ACO clusters, using various statistical measures, such as the integral of the two-point correlation function, J_3, and the probability density function (pdf). We find that the models that best reproduce the clustering of the Abell/ACO cluster sample are the CHDM and the LambdaCDM_1 models. The LambdaCDM_2 model is too strongly clustered, and this clustering is probably overestimated in our simulations as a result of the large sigma_8-value of this model. All of the other models are ruled out at a high confidence level. The pdfs of all models are well approximated by a lognormal distribution, consistent with similar findings for Abell/ACO clusters. The low-order moments of all the pdfs are found to obey a variance-skewness relation of the form gamma~=S_3sigma^4, with S_3~=1.9, independent of the primordial spectral shape and consistent

  10. Inhibitory effect of tocotrienol on eukaryotic DNA polymerase {lambda} and angiogenesis

    SciTech Connect

    Mizushina, Yoshiyuki . E-mail: mizushin@nutr.kobegakuin.ac.jp; Nakagawa, Kiyotaka; Shibata, Akira; Awata, Yasutoshi; Kuriyama, Isoko; Shimazaki, Noriko; Koiwai, Osamu; Uchiyama, Yukinobu; Sakaguchi, Kengo; Miyazawa, Teruo; Yoshida, Hiromi

    2006-01-20

    Tocotrienols, vitamin E compounds that have an unsaturated side chain with three double bonds, selectively inhibited the activity of mammalian DNA polymerase {lambda} (pol {lambda}) in vitro. These compounds did not influence the activities of replicative pols such as {alpha}, {delta}, and {epsilon}, or even the activity of pol {beta} which is thought to have a very similar three-dimensional structure to the pol {beta}-like region of pol {lambda}. Since {delta}-tocotrienol had the strongest inhibitory effect among the four ({alpha}- to {delta}-) tocotrienols, the isomer's structure might be an important factor in the inhibition of pol {lambda}. The inhibitory effect of {delta}-tocotrienol on both intact pol {lambda} (residues 1-575) and a truncated pol {lambda} lacking the N-terminal BRCA1 C-terminus (BRCT) domain (residues 133-575, del-1 pol {lambda}) was dose-dependent, with 50% inhibition observed at a concentration of 18.4 and 90.1 {mu}M, respectively. However, del-2 pol {lambda} (residues 245-575) containing the C-terminal pol {beta}-like region was unaffected. Tocotrienols also inhibited the proliferation of and formation of tubes by bovine aortic endothelial cells, with {delta}-tocotrienol having the greatest effect. These results indicated that tocotrienols targeted both pol {lambda} and angiogenesis as anti-cancer agents. The relationship between the inhibition of pol {lambda} and anti-angiogenesis by {delta}-tocotrienol was discussed.

  11. {Lambda}CDM universe in f(R) gravity

    SciTech Connect

    Dunsby, Peter K. S.; Elizalde, Emilio; Saez-Gomez, Diego; Goswami, Rituparno; Odintsov, Sergei

    2010-07-15

    Several different explicit reconstructions of f(R) gravity are obtained from the background Friedmann-Laimatre-Robertson-Walker expansion history. It is shown that the only theory whose Lagrangian is a simple function of the Ricci scalar R, that admits an exact {Lambda}CDM expansion history, is standard general relativity with a positive cosmological constant and the only way to obtain this behavior of the scale factor for more general functions of R is to add additional degrees of freedom to the matter sector.

  12. Radiative decays of the Sigma0(1385) and Lambda(1520) hyperons

    SciTech Connect

    Simon Taylor; Gordon Mutchler; CLAS Collaboration

    2005-03-01

    The electromagnetic decays of the {Sigma}{sup 0}(1385) and {Lambda}(1520) hyperons were studied in photon-induced reactions {gamma} p {yields} K{sup +} {Lambda}(1116){gamma} in the CLAS detector at the Thomas Jefferson National Accelerator Facility. We report the first observation of the radiative decay of the {Sigma}{sup 0}(1385) and a measurement of the {Lambda}(1520) radiative decay width. For the {Sigma}{sup 0}(1385) {yields} {Lambda}(1116){gamma} transition, we measured a partial width of 479 {+-} 120(stat){sub -100}{sup +81}(sys) keV, larger than all of the existing model predictions. For the {Lambda}(1520) {yields} {Lambda}(1116){gamma} transition, we obtained a partial width of 167 {+-} 43(stat){sub -12}{sup +26}(sys) keV.

  13. ON THE COMPLETENESS AND QUASIPOWER BASIS PROPERTY OF SYSTEMS \\{z^nf(\\lambda_nz)\\}

    NASA Astrophysics Data System (ADS)

    Oskolkov, V. A.

    1990-02-01

    This paper discusses questions of completeness and the quasipower property in spaces A_R of systems of functions \\{z^nf(\\lambda_nz)\\} under some natural conditions on the Taylor coefficients of the function f(z), assumed regular in a disk \\vert z\\vert. The complex numbers \\lambda_n ( n=0,1,\\dots) are subject to the condition \\vert\\lambda_n\\vert\\leqslant1. Bibliography: 8 titles.

  14. ASTEROSEISMOLOGICAL MODELING OF THE MULTIPERIODIC {lambda} BOOTIS STAR 29 CYGNI

    SciTech Connect

    Casas, R.; Moya, A.; Martin-Ruiz, S.; Amado, P. J.; Garrido, R.; Suarez, J. C.; Rodriguez-Lopez, C

    2009-05-20

    The present work focuses on the discussion of the {lambda} Bootis nature of the multiperiodic {delta} Scuti star HD 192640 (29 Cyg), through a comprehensive asteroseismic modeling. Some of the most recent asteroseismic tools are used to check whether the observed low metallicity is internal, i.e., intrinsic, present throughout the star, or due to superficial processes as accretion, diffusive settling, radiative levitation, mass loss, etc. The modeling method uses some of the most recent tools, including: (1) effects of rotation on equilibrium models, on the adiabatic oscillation spectrum, and its influence in multicolor observables, (2) nonadiabatic stability of radial and nonradial modes, (3) inclusion of the atmosphere-pulsation interaction for a more accurate multicolor mode identification, and (4) ratio between radial modes n = 4 and n = 5 in the framework of Petersen diagrams. The analysis performed reveals that the models fulfilling all the constraints are those in the middle of the main sequence (MS), with subsolar metallicity, except some other unlikely possibilities. Therefore, this study does not support the idea of the {lambda} Bootis stars being zero-age MS or pre-MS stars interacting with their primordial cloud of gas and dust, but suggest the explanation of their nature as submetallic MS objects. Nevertheless, more accurate multicolor photometric observations are required for a more conclusive study using the procedure presented here, since the observational errors are too large for a definitive rejection of any of the possible explanations.

  15. Detection of single lambda DNA fragments by flow cytometry

    SciTech Connect

    Johnson, M.E.; Goodwin, P.M.; Ambrose, W.P.; Martin, J.C.; Marrone, B.L.; Keller, R.A. )

    1993-01-01

    The authors have demonstrated flow cytometric detection and sizing of single pieces of fluorescently stained lambda DNA (48.5 kb) and individual Kpn I restriction fragments of lambda DNA at 17.05 kb and 29.95 kb. DNA fragments were stained stoichiometrically with an intercalating dye such that the fluorescence from each fragment was directly proportional to fragment length. Laser powers range from 10 to 100 mW and transit times through the focused laser beam were several milliseconds. Measurements were made using time-resolved single photon counting of the detected fluorescence emission from individual stained DNA fragments. Samples were analyzed at rates of about 50 fragments per second. The measured fluorescence intensities are linearly correlated with DNA fragment length over the range measured. Detection sensitivity and resolution needed for analysis of small pieces of DNA are discussed and a comparison of single photon counting measurements of DNA fragments to measurements using more conventional flow cytometers is made. Applications of this methodology to DNA sizing and DNA fingerprinting are discussed.

  16. Degradation of lambda-carrageenan by Pseudoalteromonas carrageenovora lambda-carrageenase: a new family of glycoside hydrolases unrelated to kappa- and iota-carrageenases.

    PubMed

    Guibet, Marion; Colin, Sébastien; Barbeyron, Tristan; Genicot, Sabine; Kloareg, Bernard; Michel, Gurvan; Helbert, William

    2007-05-15

    Carrageenans are sulfated galactans found in the cell walls of red seaweeds. They are classified according to the number and the position of sulfate ester groups. lambda-Carrageenan is the most sulfated carrageenan and carries at least three sulfates per disaccharide unit. The sole known depolymerizing enzyme of lambda-carrageenan, the lambda-carrageenase from Pseudoalteromonas carrageenovora, has been purified, cloned and sequenced. Sequence analyses have revealed that the lambda-carrageenase, referred to as CglA, is the first member of a new family of GHs (glycoside hydrolases), which is unrelated to families GH16, that contains kappa-carrageenases, and GH82, that contains iota-carrageenases. This large enzyme (105 kDa) features a low-complexity region, suggesting the presence of a linker connecting at least two independent modules. The N-terminal region is predicted to fold as a beta-propeller. The main degradation products have been purified and characterized as neo-lambda-carratetraose [DP (degree of polymerization) 4] and neo-lambda-carrahexaose (DP6), indicating that CglA hydrolyses the beta-(1-->4) linkage of lambda-carrageenan. LC-MALLS (liquid chromatography-multi-angle laser light scattering) and (1)H-NMR monitoring of the enzymatic degradation of lambda-carrageenan indicate that CglA proceeds according to an endolytic mode of action and a mechanism of inversion of the anomeric configuration. Using 2-aminoacridone-labelled neo-lambda-carrabiose oligosaccharides, in the present study we demonstrate that the active site of CglA comprises at least 8 subsites (-4 to +4) and that a DP6 oligosaccharide binds in the subsites -4 to +2 and can be hydrolysed into DP4 and DP2.

  17. Circular dimers of a lambda DNA in infected, nonlysogenic Escherichia coli.

    PubMed

    Freifelder, D; Baran, N; Folkmanis, A; Freifelder, D L

    1977-09-01

    Covalently closed circular dimers of phage lambda DNA have been found in Escherichia coli infected with lambda. These dimers can be formed by either the lambda Red or Int systems, by a nonrecombinational replicative mechanism requiring the activity of the lambda O and P genes or by joining of the cohesive ends. Dimers mediated by the E. coli Rec system have not been observed. Those formed by the Int system often result from recombination between different DNA molecules; however, the Red-mediated dimers may be a result of replicative extension of a single DNA molecule. Trimers have also been observed but studied only briefly.

  18. Direct and general selection for lysogens of Escherichia coli by phage lambda recombinant clones.

    PubMed

    Henry, M F; Cronan, J E

    1991-06-01

    We report a simple in vivo technique for introducing an antibiotic resistance marker into phage lambda. This technique could be used for direct selection of lysogens harboring recombinant phages from the Kohara lambda bank (a collection of ordered lambda clones carrying Escherichia coli DNA segments). The two-step method uses homologous recombination and lambda DNA packaging to replace the nonessential lambda DNA lying between the lysis genes and the right cohesive (cos) end with the neomycin phosphotransferase (npt) gene from Tn903. This occurs during lytic growth of the phage on a plasmid-containing host strain. Neomycin-resistant (npt+) recombinant phages are then selected from the lysates containing the progeny phage by transduction of a polA1 lambda lysogenic host strain to neomycin resistance. We have tested this method with two different Kohara lambda phage clones; in both cases, neomycin resistance cotransduced with the auxotrophic marker carried by the lambda clone, indicating complete genetic linkage. Linkage was verified by restriction mapping of purified DNA from a recombinant phage clone. We also demonstrate that insertion of the npt+ recombinant phages into the lambda prophage can be readily distinguished from insertion into bacterial chromosomal sequences.

  19. Measurement of the Lambda_b Lifetime in Lambda_b -> Lambda_c+ pi- Decays in p-pbar Collisions at sqrt(s) = 1.96 TeV

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2009-12-01

    We report a measurement of the lifetime of the {Lambda}{sub b}{sup 0} baryon in decays to the {Lambda}{sub c}{sup +} {pi}{sup -} final state in a sample corresponding to 1.1 fb{sup -1} collected in p{bar p} collisions at {radical}s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed {Lambda}{sub b}{sup 0} events we measure {tau}({Lambda}{sub b}{sup 0}) = 1.401 {+-} 0.046 (stat) {+-} 0.035 (syst) ps (corresponding to c{tau}({Lambda}{sub b}{sup 0}) = 420.1 {+-} 13.7 (stat) {+-} 10.6 (syst) {micro}m, where c is the speed of light). The ratio of this result and the world average B{sup 0} lifetime yields {tau}({Lambda}{sub b}{sup 0})/{tau}(B{sup 0}) = 0.918 {+-} 0.038 (stat and syst), in good agreement with recent theoretical predictions.

  20. OT1_hmaness_1: Planets, Debris Disks, and the Lambda Bootis Stars

    NASA Astrophysics Data System (ADS)

    Maness, H.

    2010-07-01

    We propose to explore the link between lambda Bootis stars, debris disks, and planetesimal formation and evolution. The lambda Boo stars are a rare type of peculiar A star (2%), which are Population 1 and metal poor. Planet bearing systems and debris disk stars appear unusually well represented in the lambda Boo class: for example, beta Pic, Vega, and HR 8799 are all lambda Boo candidates. A small sample of 14 lambda Boo stars observed by Spitzer suggests an occurrence of infrared excess approaching 100%. Only two lambda Boo stars are included in the DEBRIS/DUNES Herschel key program debris disk surveys. We will use PACS/Herschel to make sensitive, high-resolution maps of 27 new lambda Boo stars. Like DEBRIS/DUNES, we will reach the stellar photosphere for all targets, enabling a measurement of the true rate of excess infrared emission among lambda Boo stars compared to normal A stars. The depletion pattern of heavy elements in the atmospheres of lambda Boo stars suggests they may have accreted gas from which dust grains have condensed and been removed: this gas may be circumstellar gas that has formed planetesimals or dusty interstellar gas. While the circumstellar disk scenario predicts sizes of a few hundred AU, the cloud accretion scenario predicts 1000-2000 AU bow structures oriented in the direction of the relative motion of the cloud and star. With target distances of < 140 pc, these bow structures are expected to be resolved for all targets. These will be the first mid-infrared observations of lambda Boo stars outside of the low density Local Bubble: if interstellar medium interactions dominate the lambda Boo phenomenon then systematic variations in excess strength and morphology may occur with distance.

  1. Longitudinal Spin Transfer to Lambda and Lambda bar Hyperons in Polarized Proton-Proton Collisions at sqrt s = 200 GeV

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hypersons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at RHIC. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {bar {Lambda}} hyperons with <{eta}> = 0.5 and = 3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  2. [A case of lambda-expressing pulmonary MALT lymphoma with dual clonal rearrangements of kappa and lambda immunoglobulin light chain gene].

    PubMed

    Oh, Hye Ryong; Lee, Mi Ja; Park, Geon; Moon, Dae Soo; Park, Young Jin; Jang, Sook Jin

    2009-06-01

    A 70-yr-old woman was hospitalized with a history of dry cough. Bronchial endoscopy and transbronchial lung biopsy were performed. However, the findings of histopathology and immunohistochemistry were not sufficient to decide whether the lesion was benign or malignant, because of the presence of crush artifacts in the biopsy specimens. We performed B-cell clonality studies using BIOMED-2 multiplex PCR (InVivoScribe Technologies, USA) to detect clonal rearrangements in the immunoglobulin gene. The results of multiplex PCR showed clonal rearrangements of both kappa and lambda immunoglobulin light chain genes. The findings of immunochemistry revealed that the lesion expressed lambda light chain, but not kappa light chain. Based on the clinical, pathologic, and molecular findings, this case was diagnosed as pulmonary MALT lymphoma. We report the first case in Korea of lambda-expressing MALT lymphoma that is shown to have dual clonal rearrangements of kappa and lambda immunoglobulin light chain gene by multiplex PCR.

  3. AL amyloidosis with IgD-lambda monoclonal gammopathy and lambda-type Bence-Jones protein: successful treatment by autologous stem cell transplantation.

    PubMed

    Sakurai-Chin, Chanhyok; Ubara, Yoshifumi; Suwabe, Tatsuya; Hoshino, Junichi; Yonaha, Tomoki; Hasegawa, Eiko; Sumida, Keiichi; Hiramatsu, Rikako; Yamanouchi, Masayuki; Hayami, Noriko; Yamauchi, Junji; Tominaga, Naoyuki; Sawa, Naoki; Takemoto, Fumi; Masuoka, Kazuhiro; Takaichi, Kenmei; Oohashi, Kenichi

    2010-10-01

    A 45-year-old Japanese woman had been diagnosed with monoclonal gammopathy of undetermined significance (MGUS) featuring urinary Bence-Jones protein of the lambda type (BJP-lambda) for 11 years. She then developed eyelid purpura, dyspnea, and flank pain. Abdominal CT scans revealed renal infarction. Biopsy of the kidney, heart, jejunum, and skin demonstrated amyloid deposits in the vessel walls, but not in the glomeruli. She was diagnosed as having AL amyloidosis with IgD-lambda monoclonal gammopathy and BJP-lambda. Autologous stem cell transplantation (SCT) was done after chemotherapy with vincristine, daunorubicin, dexamethasone (VAD), and high-dose melphalan (HDM). This reduced the IgD level from 156 to 0.1 mg/dL, along with the disappearance of BJP, despite cerebral infarction during chemotherapy. We recommend SCT for patients with IgD-associated AL amyloidosis.

  4. Vortex Loops at the Superfluid Lambda Transition: An Exact Theory?

    NASA Technical Reports Server (NTRS)

    Williams, Gary A.

    2003-01-01

    A vortex-loop theory of the superfluid lambda transition has been developed over the last decade, with many results in agreement with experiments. It is a very simple theory, consisting of just three basic equations. When it was first proposed the main uncertainty in the theory was the use Flory scaling to find the fractal dimension of the random-walking vortex loops. Recent developments in high-resolution Monte Carlo simulations have now made it possible to verify the accuracy of this Flory-scaling assumption. Although the loop theory is not yet rigorously proven to be exact, the Monte Carlo results show at the least that it is an extremely good approximation. Recent loop calculations of the critical Casimir effect in helium films in the superfluid phase T < Tc will be compared with similar perturbative RG calculations in the normal phase T > Tc; the two calculations are found to match very nicely right at Tc.

  5. The Ba II [lambda]4554 resonance line and solar granulation

    NASA Astrophysics Data System (ADS)

    Olshevsky, V. L.; Shchukina, N. G.

    We present the results of an investigation of the impact of NLTE effects and of granulation inhomogeneities on the solar Ba II [lambda]4554 Å line. Our analysis is based on both the classical one-dimensional (1D) solar atmosphere models and on the new generation of three-dimensional (3D) hydrodynamical models. We show that NLTE and 3D effects have to be taken into account for reliable diagnostics of the solar atmosphere using this line. We analyse the influence of different parameters on the line shape. It turns out to be most sensitive to collisional broadening and barium abundance. Uncertainties in the oscillator strength, micro- and macroturbulence (in 1D-case) have a secondary importance. We have derived the barium abundance assuming NLTE. We find ABa = 2.16 in good agreement with the recent result of Asplund et al. (2005).

  6. Spectral diagnostics of high energy emission in lambda Eri

    NASA Technical Reports Server (NTRS)

    Smith, Myron

    1995-01-01

    Multi-line observations of the optical spectrum of lambda Eri demonstrates that rapidly varying, low-velocity emissions occur in several He I lines even when H alpha shows no emission. A peculiar aspect of the He I emissions is that the ratio 5876/6678 is = 1. A theory of helium line formation generally admits two common emission mechanisms. The first is recombination/cascades, which is well known to give a ratio of greater than or equal to 3. The second is a non-LTE effect that occurs in hot (O-type) photospheres when resonance He I 584 radiation becomes transparent and drives single lines along into the emission. To accommodate a ratio of 5876/6678 = 1 may require that both processes sometimes operate at the same time, presumably in separate localities near the surface of this star.

  7. A Lambda 1400 spectrophotometric census of the Orion belt region

    NASA Technical Reports Server (NTRS)

    Brown, Douglas N.; Shore, Steven N.

    1986-01-01

    Low dispersion IUE spectrophotometry were used to generate a pair of photometric indices which measure the strength of the broad continuum absorption feature at 1400 A, likely an autoionizing transition of Si II. Calibration of the indices as identifiers of silicon overabundance is based on measurements of 25 IUE spectral standards and a sample of O8-A0 IV-V stars, 18 of them silicon stars. The correlations of delta alpha 1400 with delta alpha 5200 and delta (VI-G) support the association of the lambda 5200 feature with silicon. Using this technique, a magnitude limited survey of 28 B-stars in sub-groups b1, b2 and b3 of the Orion OB1 association was conducted. Two previously unrecognized candidate (perhaps weakly overabundant) silicon stars, HD 37187 and BD - 0 deg 984 are identified.

  8. Directed evolution of nucleotide-based libraries using lambda exonuclease.

    PubMed

    Lim, Bee Nar; Choong, Yee Siew; Ismail, Asma; Glökler, Jörn; Konthur, Zoltán; Lim, Theam Soon

    2012-12-01

    Directed evolution of nucleotide libraries using recombination or mutagenesis is an important technique for customizing catalytic or biophysical traits of proteins. Conventional directed evolution methods, however, suffer from cumbersome digestion and ligation steps. Here, we describe a simple method to increase nucleotide diversity using single-stranded DNA (ssDNA) as a starting template. An initial PCR amplification using phosphorylated primers with overlapping regions followed by treatment with lambda exonuclease generates ssDNA templates that can then be annealed via the overlap regions. Double-stranded DNA (dsDNA) is then generated through extension with Klenow fragment. To demonstrate the applicability of this methodology for directed evolution of nucleotide libraries, we generated both gene shuffled and regional mutagenesis synthetic antibody libraries with titers of 2×108 and 6×107, respectively. We conclude that our method is an efficient and convenient approach to generate diversity in nucleic acid based libraries, especially recombinant antibody libraries.

  9. Cluster headache

    MedlinePlus

    Histamine headache; Headache - histamine; Migrainous neuralgia; Headache - cluster; Horton's headache; Vascular headache - cluster ... be related to the body's sudden release of histamine (chemical in the body released during an allergic ...

  10. Genomic variation in the porcine immunoglobulin lambda variable region.

    PubMed

    Guo, Xi; Schwartz, John C; Murtaugh, Michael P

    2016-04-01

    Production of a vast antibody repertoire is essential for the protection against pathogens. Variable region germline complexity contributes to repertoire diversity and is a standard feature of mammalian immunoglobulin loci, but functional V region genes are limited in swine. For example, the porcine lambda light chain locus is composed of 23 variable (V) genes and 4 joining (J) genes, but only 10 or 11 V and 2 J genes are functional. Allelic variation in V and J may increase overall diversity within a population, yet lead to repertoire holes in individuals lacking key alleles. Previous studies focused on heavy chain genetic variation, thus light chain allelic diversity is not known. We characterized allelic variation of the porcine immunoglobulin lambda variable (IGLV) region genes. All intact IGLV genes in 81 pigs were amplified, sequenced, and analyzed to determine their allelic variation and functionality. We observed mutational variation across the entire length of the IGLV genes, in both framework and complementarity determining regions (CDRs). Three recombination hotspot motifs were also identified suggesting that non-allelic homologous recombination is an evolutionarily alternative mechanism for generating germline antibody diversity. Functional alleles were greatest in the most highly expressed families, IGLV3 and IGLV8. At the population level, allelic variation appears to help maintain the potential for broad antibody repertoire diversity in spite of reduced gene segment choices and limited germline sequence modification. The trade-off may be a reduction in repertoire diversity within individuals that could result in an increased variation in immunity to infectious disease and response to vaccination.

  11. Genomic variation in the porcine immunoglobulin lambda variable region

    PubMed Central

    Guo, Xi; Schwartz, John C.; Murtaugh, Michael P.

    2016-01-01

    Production of a vast antibody repertoire is essential for protection against pathogens. Variable region germline complexity contributes to repertoire diversity and is a standard feature of mammalian immunoglobulin loci, but functional V region genes are limited in swine. For example, the porcine lambda light chain locus is composed of 23 variable (V) genes and 4 joining (J) genes, but only 10 or 11 V and 2 J genes are functional. Allelic variation in V and J may increase overall diversity within a population, yet lead to repertoire holes in individuals lacking key alleles. Previous studies focused on heavy chain genetic variation, thus light chain allelic diversity is not known. We characterized allelic variation of the porcine immunoglobulin lambda variable (IGLV) region genes. All intact IGLV genes in 81 pigs were amplified, sequenced, and analyzed to determine their allelic variation and functionality. We observed mutational variation across the entire length of the IGLV genes, in both framework and complementarity determining regions (CDRs). Three recombination hotspots were also identified, suggesting that non-allelic homologous recombination is an evolutionarily alternative mechanism for generating germline antibody diversity. Functional alleles were greatest in the most highly expressed families, IGLV3 and IGLV8. At the population level, allelic variation appears to help maintain the potential for broad antibody repertoire diversity in spite of reduced gene segment choices and limited germline sequence modification. The trade-off may be a reduction in repertoire diversity within individuals that could result in increased variation in immunity to infectious disease and response to vaccination. PMID:26791019

  12. Polarization of Lambda0 and anti-Lambda0 inclusively produced by 610-GeV/c Sigma- and 525-GeV/c proton beams

    SciTech Connect

    Sanchez-Lopez, J.L.; Nelson, K.D.; Engelfried, J.; Akgun, U.; Alkhazov, G.; Amaro-Reyes, J.; Atamantchouk, A.G.; Ayan, A.S.; Balatz, M.Y.; Blanco-Covarrubias, A.; Bondar, N.F.; /Ball State U. /Bogazici U. /Carnegie Mellon U. /Rio de Janeiro, CBPF /Fermilab /Serpukhov, IHEP /Beijing, Inst. High Energy Phys. /Moscow, ITEP /Heidelberg, Max Planck Inst. /Moscow State U. /St. Petersburg, INP

    2007-06-01

    We have measured the polarization of {Lambda}{sup 0} and {bar {Lambda}{sup 0}} inclusively produced by 610 GeV/c {Sigma}{sup -} and 525 GeV/c proton beams in the experiment SELEX during the 1996/7 fixed target run at Fermilab. The polarization was measured as a function of the {Lambda} longitudinal momentum fraction x{sub F} and transverse momentum p{sub t}. For the {Lambda}{sup 0} produced by {Sigma}{sup -} the polarization is increasing with x{sub F} , from slightly negative at x{sub F} {approx} 0 to about 15% at large x{sub F} ; it shows a non-monotonic behavior as a function of p{sub t}. For the proton beam, the {Lambda}{sup 0} polarization is negative and decreasing as a function of x{sub F} and p{sub t}. The {bar {Lambda}{sup 0}} polarization is compatible with 0 for both beam particles over the full kinematic range. The target dependence was examined but no statistically significant difference was found.

  13. LambdaStation: Exploiting Advance Networks In Data Intensive High Energy Physics Applications

    SciTech Connect

    Harvey B. Newman

    2009-09-11

    Lambda Station software implements selective, dynamic, secure path control between local storage & analysis facilities, and high bandwidth, wide-area networks (WANs). It is intended to facilitate use of desirable, alternate wide area network paths which may only be intermittently available, or subject to policies that restrict usage to specified traffic. Lambda Station clients gain awareness of potential alternate network paths via Clarens-based web services, including path characteristics such as bandwidth and availability. If alternate path setup is requested and granted, Lambda Station will configure the local network infrastructure to properly forward designated data flows via the alternate path. A fully functional implementation of Lambda Station, capable of dynamic alternate WAN path setup and teardown, has been successfully developed. A limited Lambda Station-awareness capability within the Storage Resource Manager (SRM) product has been developed. Lambda Station has been successfully tested in a number of venues, including Super Computing 2008. LambdaStation software, developed by the Fermilab team, enables dynamic allocation of alternate network paths for high impact traffic and to forward designated flows across LAN. It negotiates with reservation and provisioning systems of WAN control planes, be it based on SONET channels, demand tunnels, or dynamic circuit networks. It creates End-To-End circuit between single hosts, computer farms or networks with predictable performance characteristics, preserving QoS if supported in LAN and WAN and tied security policy allowing only specific traffic to be forwarded or received through created path. Lambda Station project also explores Network Awareness capabilities.

  14. The risk of renal disease is increased in lambda myeloma with bone marrow amyloid deposits

    PubMed Central

    Kozlowski, Piotr; Montgomery, Scott; Befekadu, Rahel; Hahn-Strömberg, Victoria

    2017-01-01

    Background Light chain amyloidosis (AL) is a rare deposition disease and is present in 10–15% of patients with myeloma (MM). In contrast to symptomatic AL in MM, presence of bone marrow (BM) amyloid deposits (AD) in MM is not connected to kidney damage. Renal AD but not BM-AD occur mostly in MM with lambda paraprotein (lambda MM). Methods We investigated amyloid presence in BM clots taken at diagnosis in 84 patients with symptomatic MM and compared disease characteristics in MM with kappa paraprotein (kappa MM)/lambda MM with and without BM-AD. Results Lambda MM with BM-AD was compared with kappa MM without BM-AD, kappa MM with BM-AD, and lambda MM without BM-AD: lambda MM with BM-AD patients had a significantly higher mean creatinine level (4.23 mg/dL vs 1.69, 1.14, and 1.28 mg/dL, respectively) and a higher proportion presented with severe kidney failure (6/11 [55%] vs 6/32 [19%], 1/22 [5%], and 3/19 [16%], respectively). Proteinuria was more common in lambda MM with BM-AD patients compared with kappa MM without BM-AD patients (8/11 [73%] vs 5/32 [16%], respectively). Conclusion Kidney damage was more common in lambda MM with BM-AD indicating presence of renal AD. PMID:28293126

  15. Meaningful Clusters

    SciTech Connect

    Sanfilippo, Antonio P.; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2004-05-26

    We present an approach to the disambiguation of cluster labels that capitalizes on the notion of semantic similarity to assign WordNet senses to cluster labels. The approach provides interesting insights on how document clustering can provide the basis for developing a novel approach to word sense disambiguation.

  16. Cosmology with EMSS Clusters of Galaxies

    NASA Technical Reports Server (NTRS)

    Donahue, Megan; Voit, G. Mark

    1999-01-01

    We use ASCA observations of the Extended Medium Sensitivity Survey sample of clusters of galaxies to construct the first z = 0.5 - 0.8 cluster temperature function. This distant cluster temperature function, when compared to local z approximately 0 and to a similar moderate redshift (z = 0.3 - 0.4) temperature function strongly constrains the matter density of the universe. Best fits to the distributions of temperatures and redshifts of these cluster samples results in Omega(sub M) = 0.45 +/- 0.1 if Lambda = 0 and Omega = 0.27 +/- 0.1 if Lambda + Omega(sub M) = 1. The uncertainties are 1sigma statistical. We examine the systematics of our approach and find that systematics, stemming mainly from model assumptions and not measurement errors, are about the same size as the statistical uncertainty +/- 0.1. In this poster proceedings, we clarify the issue of a8 as reported in our paper Donahue & Voit (1999), since this was a matter of discussion at the meeting.

  17. Measurement of the Branching Ratio Lambda_c+ -> p pi+ pi-

    SciTech Connect

    Lopez-Hinojosa, Guillermo; /San Luis Potosi U.

    2008-03-01

    The confirmation of the Cabibbo-suppressed charm baryon decay mode {Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -} is reported. All data analyzed are from SELEX, a fixed target experiment at Fermilab that took data during 1996 and 1997, mainly with a 600 GeV/c {Sigma}{sup -} beam. The branching ratio of the Cabibbo-suppressed decay mode {Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -} relative to the Cabibbo-favored mode {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +} is measured to be: {Gamma}({Lambda}{sub c}{sup +} {yields} p{pi}{sup +}{pi}{sup -})/{Gamma}({Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +}) = 0.103 {+-} 0.022.

  18. About the Clusters Program

    EPA Pesticide Factsheets

    The Environmental Technology Innovation Clusters Program advises cluster organizations, encourages collaboration between clusters, tracks U.S. environmental technology clusters, and connects EPA programs to cluster needs.

  19. Penetration depth lambda(T) of YBa2Cu3O(7-delta) films determined from the kinetic inductance

    NASA Astrophysics Data System (ADS)

    Lee, Juyoung; Lemberger, Thomas R.

    1993-05-01

    We examine the temperature dependence of the magnetic penetration depth lambda(T) of YBa2Cu3O(7-delta), determined from the kinetic inductance of a film patterned into a long meander line. This technique has sufficient sensitivity to study lambda(T) to lower temperatures than have been examined previously. A numerical model which includes both the magnetic and kinetic inductances of the samples extracts lambda(T) from the measured voltage. In reasonable agreement with other measurements, lambda(0) about 2100 A is deduced from fitting lambda(0)-squared/lambda(T)-squared to the function 1 - (T/Tc)-squared for T/Tc greater than 0.4. We find lambda(T)/lambda(0) - 1 is proportional to (T/Tc)-squared for T/Tc between 0.06 and 0.4.

  20. MEASURING THE ULTIMATE HALO MASS OF GALAXY CLUSTERS: REDSHIFTS AND MASS PROFILES FROM THE HECTOSPEC CLUSTER SURVEY (HeCS)

    SciTech Connect

    Rines, Kenneth; Geller, Margaret J.; Kurtz, Michael J.; Diaferio, Antonaldo E-mail: diaferio@ph.unito.it

    2013-04-10

    The infall regions of galaxy clusters represent the largest gravitationally bound structures in a {Lambda}CDM universe. Measuring cluster mass profiles into the infall regions provides an estimate of the ultimate mass of these halos. We use the caustic technique to measure cluster mass profiles from galaxy redshifts obtained with the Hectospec Cluster Survey (HeCS), an extensive spectroscopic survey of galaxy clusters with MMT/Hectospec. We survey 58 clusters selected by X-ray flux at 0.1 < z < 0.3. The survey includes 22,680 unique MMT/Hectospec redshifts for individual galaxies; 10,145 of these galaxies are cluster members. For each cluster, we acquired high signal-to-noise spectra for {approx}200 cluster members and a comparable number of foreground/background galaxies. The cluster members trace out infall patterns around the clusters. The members define a very narrow red sequence. We demonstrate that the determination of velocity dispersion is insensitive to the inclusion of bluer members (a small fraction of the cluster population). We apply the caustic technique to define membership and estimate the mass profiles to large radii. The ultimate halo mass of clusters (the mass that remains bound in the far future of a {Lambda}CDM universe) is on average (1.99 {+-} 0.11)M{sub 200}, a new observational cosmological test in essential agreement with simulations. Summed profiles binned in M{sub 200} and in L{sub X} demonstrate that the predicted Navarro-Frenk-White form of the density profile is a remarkably good representation of the data in agreement with weak lensing results extending to large radius. The concentration of these summed profiles is also consistent with theoretical predictions.

  1. Data Clustering

    NASA Astrophysics Data System (ADS)

    Wagstaff, Kiri L.

    2012-03-01

    On obtaining a new data set, the researcher is immediately faced with the challenge of obtaining a high-level understanding from the observations. What does a typical item look like? What are the dominant trends? How many distinct groups are included in the data set, and how is each one characterized? Which observable values are common, and which rarely occur? Which items stand out as anomalies or outliers from the rest of the data? This challenge is exacerbated by the steady growth in data set size [11] as new instruments push into new frontiers of parameter space, via improvements in temporal, spatial, and spectral resolution, or by the desire to "fuse" observations from different modalities and instruments into a larger-picture understanding of the same underlying phenomenon. Data clustering algorithms provide a variety of solutions for this task. They can generate summaries, locate outliers, compress data, identify dense or sparse regions of feature space, and build data models. It is useful to note up front that "clusters" in this context refer to groups of items within some descriptive feature space, not (necessarily) to "galaxy clusters" which are dense regions in physical space. The goal of this chapter is to survey a variety of data clustering methods, with an eye toward their applicability to astronomical data analysis. In addition to improving the individual researcher’s understanding of a given data set, clustering has led directly to scientific advances, such as the discovery of new subclasses of stars [14] and gamma-ray bursts (GRBs) [38]. All clustering algorithms seek to identify groups within a data set that reflect some observed, quantifiable structure. Clustering is traditionally an unsupervised approach to data analysis, in the sense that it operates without any direct guidance about which items should be assigned to which clusters. There has been a recent trend in the clustering literature toward supporting semisupervised or constrained

  2. Searches for the baryon- and lepton-number violating decays $B^0\\rightarrow\\Lambda_c^ \\ell^-$, $B^-\\rightarrow\\Lambda\\ell^-$, and $B^-\\rightarrow\\bar{\\Lambda}\\ell^-$

    SciTech Connect

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Koch, H.; Schroeder, T.; /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Milan U. /Milan U. /Milan U. /Milan U. /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-06-22

    Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either {Lambda}{sub c} or {Lambda} and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range (3.2 - 520) x 10{sup -8} are set on the branching fractions at the 90% confidence level.

  3. Observation of the baryonic B-decay B0bar -> LambdaC antiproton K- pi

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2009-10-20

    The authors report the observation of the baryonic B-decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}K{sup -}{pi}{sup +}, excluding contributions from the decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar {Lambda}}K{sup -}. Using a data sample of 467 million B{bar B} pairs collected with the BABAR detector at the PEP-II storage ring at SLAC, the measured branching fraction is (4.33 {+-} 0.82){sub stat} {+-} 0.33{sub syst} {+-} 1.13{sub {Lambda}{sub c}{sup +}} x 10{sup -5}. In addition they find evidence for the resonant decay {bar B}{sup 0} {yields} {Sigma}{sub c}(2455){sup ++}{bar p}K{sup -} and determine its branching fraction to be (1.11 {+-} 0.30{sub stat} {+-} 0.09{sub syst} {+-} 0.29{sub {Lambda}{sub c}{sup +}}) x 10{sup -5}. The errors are statistical, systematic, and due to the uncertainty in the {Lambda}{sub c}{sup +} branching fraction. For the resonant decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}{bar K}*{sup 0} we obtain an upper limit of 2.42 x 10{sup -5} at 90% confidence level.

  4. {lambda}{sup 0} Polarization in Exclusive pp Reactions From the FNAL e690 Experiment

    SciTech Connect

    Felix, J.; Berisso, M. C.; Christian, D. C.; Gottschalk, E. E.; Gutierrez, G.; Wang, M. H. L. S.; Wehmann, A.; Gara, A.; Hartouni, E. P.; Knapp, B. C.; Kreisler, M. N.; Lee, S.; Markianos, K.; Moreno, G.; Reyes, M. A.; Wesson, D.

    2009-04-20

    It is an experimental evidence that all baryons are created polarized from unpolarized p-nucleus collisions. So far, the origin of this polarization remains unexplained in spite of the experimental evidences accumulated in the past thirty years. Up to these days, {lambda}{sup 0} is the most studied baryon for polarization, for it is copiously produced in p--nucleus collisions at the energies of the principal high energy physics accelerators of the world. This paper is an overview of the experimental evidences accumulated on the polarization of {lambda}{sup 0} from unpolarized exclusive pp collisions as function of x{sub F}, P{sub T}, and M({lambda}{sup 0}K{sup +}) in the past fifteen years inside Fermilab e690 experiment, in the particular reactions pp{yields}p{lambda}{sup 0}K{sup 0}{pi}{sup +}, pp{yields}pp{lambda}{sup 0}{lambda}{sup -0}, pp{yields}p{lambda}{sup 0}K{sup +}, produced at 800 GeV.

  5. Characterization of a labile naloxone binding site (lambda site) in rat brain.

    PubMed

    Grevel, J; Yu, V; Sadée, W

    1985-05-01

    A high-affinity binding site selective for naloxone and other 4,5-epoxymorphinans (lambda site) has been previously described in rat brain. Following homogenization of freshly dissected brain, the lambda sites convert from a high-affinity to a low-affinity state. When measured with [3H]naloxone, the decay is very rapid at 20 degrees C (t 1/2 less than 2 min), whereas it is progressively slowed at lower temperatures. Proteinase inhibitors, antoxidants, and sulfhydryl group-protecting agents failed to prevent this conversion. Kinetic measurements of mu and lambda binding at varying temperatures demonstrated that the decrease in lambda binding does not coincide with the concurrent increase in mu binding and that the loss of high-affinity lambda binding at 20 degrees C can be partially restored when the temperature is lowered to 0 degrees C. The low-affinity state of the lambda site is rather stable in the Tris buffer homogenates and is susceptible to digestion by a protease. The (-)-isomer of WIN 44,441, a benzomorphan drug, binds to lambda sites with moderate affinity (dissociation constant, KD = 63 nM), whereas the (+)-isomer does not (KD greater than 10,000 nM), thus establishing stereoselectivity of the binding process. Neither the high-affinity nor the low-affinity state of lambda binding is significantly affected by the presence of 100 mM sodium chloride or 50 microM Gpp(NH)p, (a GTP analog), which is in contrast to the dramatic effect of these agents on the established opioid receptor system. Naltrexone, naloxone, nalorphine, and morphine (in this order of decreasing potency) bind to the lambda site in vivo in intact rat brain over dosage ranges that are commonly employed in pharmacological studies.

  6. The holin of bacteriophage lambda forms rings with large diameter.

    PubMed

    Savva, Christos G; Dewey, Jill S; Deaton, John; White, Rebecca L; Struck, Douglas K; Holzenburg, Andreas; Young, Rye

    2008-08-01

    Holins control the length of the infection cycle of tailed phages (the Caudovirales) by oligomerizing to form lethal holes in the cytoplasmic membrane at a time dictated by their primary structure. Nothing is currently known about the physical basis of their oligomerization or the structure of the oligomers formed by any known holin. Here we use electron microscopy and single-particle analysis to characterize structures formed by the bacteriophage lambda holin (S105) in vitro. In non-ionic or mild zwitterionic detergents, purified S105, but not the lysis-defective variant S105A52V, forms rings of at least two size classes, the most common having inner and outer diameters of 8.5 and 23 nm respectively, and containing approximately 72 S105 monomers. The height of these rings, 4 nm, closely matches the thickness of the lipid bilayer. The central channel is of unprecedented size for channels formed by integral membrane proteins, consistent with the non-specific nature of holin-mediated membrane permeabilization. S105 present in detergent-solubilized rings and in inverted membrane vesicles showed similar sensitivities to proteolysis and cysteine-specific modification, suggesting that the rings are representative of the lethal holes formed by S105 to terminate the infection cycle and initiate lysis.

  7. High accuracy heat capacity measurements through the lambda transition of helium with very high temperature resolution

    NASA Technical Reports Server (NTRS)

    Fairbanks, W. M.; Lipa, J. A.

    1984-01-01

    A measurement of the heat capacity singularity of helium at the lambda transition was performed with the aim of improving tests of the Renormalization Group (RG) predictions for the static thermodynamic behavior near the singularity. The goal was to approach as closely as possible to the lambda-point while making heat capacity measurements of high accuracy. To do this, a new temperature sensor capable of unprecedented resolution near the lambda-point, and two thermal control systems were used. A short description of the theoretical background and motivation is given. The initial apparatus and results are also described.

  8. Ghost-gluon running coupling, power corrections, and the determination of {lambda}{sub MS}

    SciTech Connect

    Boucaud, Ph.; Leroy, J. P.; Le Yaouanc, A.; Micheli, J.; Pene, O.; De Soto, F.; Rodriguez-Quintero, J.

    2009-01-01

    We compute a formula including operator-product expansion power corrections to describe the running of a QCD coupling nonperturbatively defined through the ghost and gluon dressing functions. This turns out to be rather accurate. We propose the 'plateau' procedure to compute {lambda}{sub MS} from the lattice computation of the running coupling constant. We show a good agreement between the different methods which have been used to estimate {lambda}{sub MS}{sup N{sub f}}{sup =0}. We argue that {lambda}{sub MS} or the strong coupling constant computed with different lattice spacings may be used to estimate the lattice spacing ratio.

  9. Experimental Investigation Into the Aerodynamic Ground Effect of a Tailless Chevron and Lambda-shaped UCAVs

    DTIC Science & Technology

    2006-03-01

    58 Figure 39: Lambda UCAV Model and Wind Tunnel in Gridgen ..…… ………....……..60 Figure 40: Lambda UCAV Model’s...created in this study and converted it to an IGES file. The IGES file was then used in Gridgen to build a grid that was used in Fluent solver...and wind tunnel in Gridgen (28). Figure 39: Lambda UCAV model and windtunnel in Gridgen at 8 degrees AOA (28) The FLUENT solver’s resuting OGE CL

  10. High Resolution Spectroscopy of {sub {lambda}}{sup 12}B by Electroproduction

    SciTech Connect

    Iodice, M.; Cusanno, F.; Urciuoli, G. M.; Acha, A.; Ambrozewicz, P.; Coman, L.; Markowitz, P.; Moteabbed, M.; Raue, B.; Reinhold, J.; Aniol, K. A.; Margaziotis, D. J.; Baturin, P.; Jiang, X.; McCormick, K.; Bertin, P. Y.; Camsonne, A.; Ferdi, C.; Blomqvist, K. I.

    2007-08-03

    An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a {sup 12}C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring imaging Cherenkov detector were added to the hall A standard equipment. An unprecedented energy resolution of less than 700 keV FWHM has been achieved. Thus, the observed {sub {lambda}}{sup 12}B spectrum shows for the first time identifiable strength in the core-excited region between the ground-state s-wave {lambda} peak and the 11 MeV p-wave {lambda} peak.

  11. Determination of the {ital b}{r_arrow}{ital c} handedness using nonleptonic {Lambda}{sub {ital c}} decays

    SciTech Connect

    Koenig, B.; Koerner, J.G.; Kraemer, M.

    1994-03-01

    We consider possibilities to determine the handedness of {ital b}{r_arrow}{ital c} current transitions using semileptonic baryonic {Lambda}{sub {ital b}}{r_arrow}{Lambda}{sub {ital c}} transitions. We propose to analyze the longitudinal polarization of the daughter baryon {Lambda}{sub {ital c}} by using momentum-spin correlation measurements in the form of forward-backward (FB) asymmetry measures involving its nonleptonic decay products. We use an explicit form factor model to determine the longitudinal polarization of {Lambda}{sub {ital c}} in the semileptonic decay {Lambda}{sub {ital b}}{r_arrow}{Lambda}{sub {ital c}}+{ital l}{sup {minus}}+{bar {nu}}{sub {ital l}}. The mean longitudinal polarization of {Lambda}{sub {ital c}} is negative (positive) for left-chiral (right-chiral) {ital b}{r_arrow}{ital c} current transitions. The frame-dependent longitudinal polarization of {Lambda}{sub {ital c}} is large ({congruent}80%) in the {Lambda}{sub {ital b}} rest frame and somewhat smaller (30%--40%) in the lab frame when the {Lambda}{sub {ital b}}`s are produced on the {ital Z}{sup 0} peak. We suggest to use nonleptonic decay modes of {Lambda}{sub {ital c}} to analyze its polarization and thereby to determine the chirality of the {ital b}{r_arrow}{ital c} transition. Since {Lambda}{sub {ital b}}`s produced on the {ital Z}{sup 0} are expected to be polarized we discuss issues of the polarization transfer in {Lambda}{sub {ital b}}{r_arrow}{Lambda}{sub {ital c}} transitions. We also investigate the {ital p}{sub {perpendicular}}- and {ital p}-cut sensitivity of our predictions for the polarization of {Lambda}{sub {ital c}}.

  12. Constraints on the Energy Content of the Universe from a Combination of Galaxy Cluster Observables

    NASA Technical Reports Server (NTRS)

    Molnar, Sandor M.; Haiman, Zoltan; Birkinshaw, Mark; Mushotzky, Richard F.

    2003-01-01

    We demonstrate that constraints on cosmological parameters from the distribution of clusters as a function of redshift (dN/dz) are complementary to accurate angular diameter distance (D(sub A)) measurements to clusters, and their combination significantly tightens constraints on the energy density content of the Universe. The number counts can be obtained from X-ray and/or SZ (Sunyaev-Ze'dovich effect) surveys, and the angular diameter distances can be determined from deep observations of the intra-cluster gas using their thermal bremsstrahlung X-ray emission and the SZ effect. We combine constraints from simulated cluster number counts expected from a 12 deg(sup 2) SZ cluster survey and constraints from simulated angular diameter distance measurements based on the X-ray/SZ method assuming a statistical accuracy of 10% in the angular diameter distance determination of 100 clusters with redshifts less than 1.5. We find that Omega(sub m), can be determined within about 25%, Omega(sub lambda) within 20% and w within 16%. We show that combined dN/dz+(sub lambda) constraints can be used to constrain the different energy densities in the Universe even in the presence of a few percent redshift dependent systematic error in D(sub lambda). We also address the question of how best to select clusters of galaxies for accurate diameter distance determinations. We show that the joint dN/dz+ D(lambda) constraints on cosmological parameters for a fixed target accuracy in the energy density parameters are optimized by selecting clusters with redshift upper cut-offs in the range 0.55 approx. less than 1. Subject headings: cosmological parameters - cosmology: theory - galaxies:clusters: general

  13. Testing the renormalisation group theory of cooperative transitions at the lambda point of helium

    NASA Technical Reports Server (NTRS)

    Lipa, J. A.; Li, Q.; Chui, T. C. P.; Marek, D.

    1988-01-01

    The status of high resolution tests of the renormalization group theory of cooperative phase transitions performed near the lambda point of helium is described. The prospects for performing improved tests in space are discussed.

  14. Evidence for B Semileptonic Decays into the Lambda_c Charm Baryon

    SciTech Connect

    Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Lopez, L.; Palano, Antimo; Pappagallo, M.; Eigen, G.; Stugu, Bjarne; Sun, L.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Cahn, Robert N.; Jacobsen, R.G.; /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Banca di Roma /Frascati /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2008-11-05

    We present the first evidence for B semileptonic decays into the charmed baryon {Lambda}{sub c}{sup +} based on 420 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We measure the relative branching fraction {Beta}({bar B} {yields} {Lambda}{sub c}{sup +} X{ell}{sup -}{bar {nu}}{sub {ell}})/{Beta}({bar B} {yields} {Lambda}{sub c}{sup +}/{bar {Lambda}}{sub c}{sup -}X) = (3.2 {+-} 0.9{sub stat.} {+-} 0.9{sub syst.})%. The significance of the signal including the systematic uncertainty is 4.9 standard deviations.

  15. Absence of lambda immunoglobulin sequences on the supernumerary chromosome of the "cat eye" syndrome.

    PubMed

    Hough, C A; White, B N; Holden, J J

    1995-09-11

    The supernumerary bisatellited chromosome causing the "cat eye" syndrome (CES) is of chromosome 22 origin and consists of an inverted duplication of the 22pter-->22q11.2 region. To determine the extent of involvement of band q11.2 on the bisatellited chromosome, copy number assessment of sequences homologous to cloned lambda immunoglobulin (lambda Ig) gene region probes was carried out on DNA from individuals with CES using densitometric analysis of Southern blots. None of the 10 lambda Ig sequences studied was found in increased copy number in DNA from any of the 10 CES individuals tested, indicating that these sequences are not present on the supernumerary chromosome. The breakpoints involved in the generation of the bisatellited supernumerary chromosome associated with CES are therefore proximal to the lambda Ig gene region.

  16. Electromagnetic Decay of the $\\Sigma^{0}(1385)$ to $\\Lambda\\gamma$

    SciTech Connect

    Keller, Dustin; Adhikari, Krishna; Adikaram-Mudiyanselage, Dasuni; Aghasyan, Mher; Amaryan, Moscov; Baghdasaryan, Hovhannes; Ball, J P; Ball, Jacques; Battaglieri, Marco; Batourine, V; Bedlinskiy, Ivan; Bennett, Robert; Biselli, Angela; Branford, Derek; Briscoe, Wilbert; Brooks, William; Burkert, Volker; Careccia, Sharon; Carman, Daniel; Casey, Liam; Cole, Philip; Contalbrigo, Marco; Crede, Volker; D'Angelo, Annalisa; Daniel, AJI; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Deur, Alexandre; Dey, Biplap; Dickson, Richard; Djalali, Chaden; Doughty, David; Dupre, Raphael; Egiyan, Hovanes; El Alaoui, Ahmed; Elfassi, Lamiaa; Eugenio, Paul; Fedotov, Gleb; Fegan, Stuart; Forest, Tony; Gabrielyan, Marianna; Gavalian, Gagik; Gevorgyan, Nerses; Giovanetti, Kevin; Girod, Francois-Xavier; Gohn, Wesley; Golovach, Evgeny; Gothe, Ralf; Graham, Lewis; Guidal, Michel; Guegan, Baptiste; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Holtrop, Maurik; Ilieva, Yordanka; Ireland, David; Isupov, Evgeny; Jawalkar, Sucheta; Jenkins, David; Jo, Hyon-Suk; Joo, Kyungseon; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Andrey; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Konczykowski, Piotr; Kubarovsky, Valery; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lu, Haiyun; MacGregor, Ian; Markov, Nikolai; McAndrew, Josephine; KcKinnon, Bryan; Meyer, Curtis; Micherdzinska, Anna; Mirazita, Marco; Mokeev, Viktor; Moreno, Brahim; Moriya, Kei; Morrison, Brian; Moutarde, Herve; Munevar Espitia, Edwin; Nadel-Turonski, Pawel; Ni, Andrey; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Osipenko, Mikhail; Ostrovidov, Alexander; Paremuzyan, Rafayel; Park, Kijun; Park, Sungkyun; Pasyuk, Eugene; Pasyuk, Evgueni; Pereira, Sergio; Pappalardo, Luciano; Pisano, Silvia; Pogorelko, Oleg; Pozdnyakov, Sergey; Price, John; Procureur, Sebastien; Protopopescu, Dan; Raue, Brian; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Saini, Mukesh; Salgado, Carlos; Schott, Diane; Schumacher, Reinhard; Seder, Erin; Seraydaryan, Heghine; Sharabian, Youri; Smith, Elton; Smith, Gregory; Sober, Daniel; Stepanyan, Stepan; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tang, Wei; Taylor, Charles; Vernarsky, Brian; Vineyard, Michael; Voutier, Eric; Weinstein, Lawrence; Watts, Daniel; Wood, Michael; Zachariou, Nicholas; Zana, Lorenzo; Zhao, Bo; Zhao, Zhiwen

    2011-04-01

    The electromagnetic decay $\\Sigma^0(1385) \\to \\Lambda \\gamma$ was studied using the CLAS detector at the Thomas Jefferson National Accelerator Facility. A real photon beam with a maximum energy of 3.8 GeV was incident on a proton target, producing an exclusive final state of $K^+\\Sigma^{*0}$. We report the decay widths ratio $\\Sigma^0(1385) \\to \\Lambda\\gamma$/ $\\Sigma^0(1385) \\to \\Lambda\\pi^0$ = $1.42 \\pm 0.12(\\text{stat})_{-0.07}^{+0.11}(\\text{sys})$%. This ratio is larger than most theoretical predictions by factors ranging from 1.5-3, but is consistent with the only other experimental measurement. From the reported ratio we calculate the partial width and electromagnetic transition magnetic moment for $\\Sigma^0(1385) \\to \\Lambda\\gamma$.

  17. The First Generation of Stars in Lambda-CDM Cosmology

    SciTech Connect

    Gao, Liang; Abel, T.; Frenk, C.S.; Jenkins, A.; Springel, V.; Yoshida, N.; /Nagoya U.

    2006-10-10

    We have performed a large set of high-resolution cosmological simulations using smoothed particle hydrodynamics (SPH) to study the formation of the first luminous objects in the {Lambda}CDM cosmology. We follow the collapse of primordial gas clouds in eight early structures and document the scatter in the properties of the first star-forming clouds. Our first objects span formation redshifts from z {approx} 10 to z {approx} 50 and cover an order of magnitude in halo mass. We find that the physical properties of the central star-forming clouds are very similar in all of the simulated objects despite significant differences in formation redshift and environment. This suggests that the formation path of the first stars is largely independent of the collapse redshift; the physical properties of the clouds have little correlation with spin, mass, or assembly history of the host halo. The collapse of proto-stellar objects at higher redshifts progresses much more rapidly due to the higher densities, which accelerates the formation of molecular hydrogen, enhances initial cooling and shortens the dynamical timescales. The mass of the star-forming clouds cover a broad range, from a few hundred to a few thousand solar masses, and exhibit various morphologies: some have disk-like structures which are nearly rotational supported; others form flattened spheroids; still others form bars. All of them develop a single protostellar ''seed'' which does not fragment into multiple objects up to the moment that the central gas becomes optically thick to H{sub 2} cooling lines. At this time, the instantaneous mass accretion rate onto the centre varies significantly from object to object, with disk-like structures having the smallest mass accretion rates. The formation epoch and properties of the star-forming clouds are sensitive to the values of cosmological parameters.

  18. Analysis techniques for the {Lambda}(1405) in p+p reactions

    SciTech Connect

    Siebenson, Johannes

    2010-12-28

    We present an analysis of the {Lambda}(1405){yields}{Sigma}{sup {+-}}{pi}{sup {+-}} decay in p+p reactions at 3.5 GeV kinetic beam energy. The data were taken with the High Acceptance Di-Electron Spectrometer (HADES). The extraction of the {Lambda}(1405) signal was achieved by an effective background suppression combined with a quantitatively precise determination and identification of the remaining background sources. The different techniques, used for this analysis, are presented in this work.

  19. FY04 IRAD-funded GSFC Lambda Network (L-Net) Web Pages and Related Presentations

    NASA Technical Reports Server (NTRS)

    Gary, J. Patrick

    2005-01-01

    This presentation discusses the advances in Networking Technology combining the Global Lambda Integrated Facility (GLIF) cooperation with the National Lambda Rail (NLR) implementation. It also focuses on New NASA science needing Gigbit per second networks (Gbps) with coordinated Earth Observing Program, hurricane predictions, global aerosols, remote viewing and manipulation of large Earth Science Data Sets, integration of laser and radar topographic data with land cover data.

  20. A SURVEY FOR PLANETARY NEBULAE IN M31 GLOBULAR CLUSTERS

    SciTech Connect

    Jacoby, George H.; De Marco, Orsola; Lee, Myung Gyoon; Herrmann, Kimberly A.; Hwang, Ho Seong; Davies, James E.; Kaplan, Evan E-mail: rbc@astro.psu.edu E-mail: mglee@astrog.snu.ac.kr E-mail: hhwang@cfa.harvard.edu E-mail: evanskaplan@gmail.com

    2013-05-20

    We report the results of an [O III] {lambda}5007 spectroscopic survey for planetary nebulae (PNe) located within the star clusters of M31. By examining R {approx} 5000 spectra taken with the WIYN+Hydra spectrograph, we identify 3 PN candidates in a sample of 274 likely globular clusters, 2 candidates in objects which may be globular clusters, and 5 candidates in a set of 85 younger systems. The possible PNe are all faint, between {approx}2.5 and {approx}6.8 mag down the PN luminosity function, and, partly as a consequence of our selection criteria, have high excitation, with [O III] {lambda}5007 to H{beta} ratios ranging from 2 to {approx}> 12. We discuss the individual candidates, their likelihood of cluster membership, and the possibility that they were formed via binary interactions within the clusters. Our data are consistent with the suggestion that PN formation within globular clusters correlates with binary encounter frequency, though, due to the small numbers and large uncertainties in the candidate list, this study does not provide sufficient evidence to confirm the hypothesis.

  1. VLT Spectroscopy of the Sgr A* Stellar Cluster

    NASA Astrophysics Data System (ADS)

    Eckart, A.; Ott, T.; Genzel, R.

    1999-12-01

    We have obtained new near-infrared observations of the central stellar cluster of our Galaxy carried out with the infrared spectrometer ISAAC at the ESO VLT and the MPE speckle camera SHARP at the ESO NTT. With ISAAC we used a spectral resolution of lambda/Delta lambda ~ 3500 on the 2.058 micron He I, 2.165 micron Br-gamma emission lines, and 2.29 micron CO bandhead absorption line. The data demonstrate clearly that there is no strong CO bandhead absorption originating in the northern part (S1/S2 area) of the central stellar cluster at the position of Sgr A*. This makes it likely that the K ~ 14.5 fast moving objects are O9 - B0.5 stars with masses of 15 to 20 Msun. Weak CO bandhead absorption in the southern part of the cluster (S10/S11 area) could be due to contributions from neighbouring stars. We have also detected Br-gamma and He I line emission at the position of the central stellar cluster which could be associated with the 'mini-spiral' rather than with the Sgr A* cluster itself. At the NTT we obtained another epoch to measure the proper motion structure and variability of sources in the central stellar cluster (see Ott, Eckart, Genzel 1999). The changes of source positions are consistent with the proper motion velocities derived from earlier epochs.

  2. EVIDENCE FOR RAPID REDSHIFT EVOLUTION OF STRONG CLUSTER COOLING FLOWS

    SciTech Connect

    Samuele, R.; McNamara, B. R.; Vikhlinin, A.; Mullis, C. R.

    2011-04-10

    We present equivalent widths of the [O II]{lambda}3727 and H{alpha} nebular emission lines for 77 brightest cluster galaxies (BCGs) selected from the 160 Square Degree ROSAT X-ray survey. We find no [O II]{lambda}3727 or H{alpha} emission stronger than -15 A or -5 A, respectively, in any BCG. The corresponding emission-line luminosities lie below L {approx} 6 x 10{sup 40} erg s{sup -1}, which is a factor of 30 below that of NGC 1275 in the Perseus Cluster. A comparison to the detection frequency of nebular emission in BCGs at z {approx}< 0.35 drawn from the Brightest Cluster Survey indicates that we should have detected roughly one dozen emission-line galaxies, assuming that the two surveys are selecting similar clusters in the X-ray luminosity range 10{sup 42} erg s{sup -1} to 5 x 10{sup 44} erg s{sup -1}. The absence of luminous nebular emission (i.e., Perseus-like systems) in our sample is consistent with an increase in the number density of strong cooling flow (cooling core) clusters between z = 0.5 and today. The decline in their numbers at higher redshift could be due to cluster mergers and heating by active galactic nuclei.

  3. Quintuplet Cluster

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Penetrating 25,000 light-years of obscuring dust and myriad stars, NASA's Hubble Space Telescope has provided the clearest view yet of one of the largest young clusters of stars inside our Milky Way galaxy, located less than 100 light-years from the very center of the Galaxy. Having the equivalent mass greater than 10,000 stars like our sun, the monster cluster is ten times larger than typical young star clusters scattered throughout our Milky Way. It is destined to be ripped apart in just a few million years by gravitational tidal forces in the galaxy's core. But in its brief lifetime it shines more brightly than any other star cluster in the Galaxy. Quintuplet Cluster is 4 million years old. It has stars on the verge of blowing up as supernovae. It is the home of the brightest star seen in the galaxy, called the Pistol star. This image was taken in infrared light by Hubble's NICMOS camera in September 1997. The false colors correspond to infrared wavelengths. The galactic center stars are white, the red stars are enshrouded in dust or behind dust, and the blue stars are foreground stars between us and the Milky Way's center. The cluster is hidden from direct view behind black dust clouds in the constellation Sagittarius. If the cluster could be seen from earth it would appear to the naked eye as a 3rd magnitude star, 1/6th of a full moon's diameter apart.

  4. Isolation and characterization of mutations in the bacteriophage lambda terminase genes.

    PubMed Central

    Davidson, A; Yau, P; Murialdo, H; Gold, M

    1991-01-01

    The terminase enzyme of bacteriophage lambda is a hetero-oligomeric protein which catalyzes the site-specific endonucleolytic cleavage of lambda DNA and its packaging into phage proheads; it is composed of the products of the lambda Nul and A genes. We have developed a simple method to select mutations in the terminase genes carried on a high-copy-number plasmid, based on the ability of wild-type terminase to kill recA strains of Escherichia coli. Sixty-three different spontaneous mutations and 13 linker insertion mutations were isolated by this method and analyzed. Extracts of cells transformed by mutant plasmids displayed variable degrees of reduction in the activity of one or both terminase subunits as assayed by in vitro lambda DNA packaging. A method of genetically mapping plasmid-borne mutations in the A gene by measuring their ability to rescue various lambda Aam phages showed that the A mutations were fairly evenly distributed across the gene. Mutant A genes were also subcloned into overproducing plasmid constructs, and it was determined that more than half of them directed the synthesis of normal amounts of full-length A protein. Three of the A gene mutants displayed dramatically reduced in vitro packaging activity only when immature (uncut) lambda DNA was used as the substrate; therefore, these mutations may lie in the endonuclease domain of terminase. Interestingly, the putative endonuclease mutations mapped in two distinct locations in the A gene separated by a least 400 bp. Images PMID:1830578

  5. Modified van Vaals-Bergman coaxial cable coil (lambda coil) for high-field imaging.

    PubMed

    Matsuzawa, H; Nakada, T

    1996-03-01

    An easily constructed, low-capacitive coupling volume coil based on the van Vaals-Bergman coaxial cable coil for high field imaging is described. The coil (designated "lambda coil") was constructed using two 5/4 length 50 omega coaxial cables matched to a 50 omega transmission line with LC bridge balun. The standing wave on the single 5/4 lambda length coaxial cable provides two points of current maxima in oppositional direction. Therefore, the four current elements necessary for effective B1 field generation can be obtained by two 5/4 lambda length coaxial cables arranged analogous to 1/2 lambda T-antenna. Capacitive coupling between the coil elements and conductive samples (i.e. animals) is minimized by simply retaining the shield of the coaxial cable for the area of voltage maxima. The lambda coil exhibited excellent performance as a volume coil with a high quality factor and highly homogeneous rf fields. Because of its dramatically simple architecture and excellent performance, the lambda coil configuration appears to be an economical alternative to the original van Vaals-Bergman design, especially for research facilities with a high field magnet and limited bore space.

  6. The Voronoi Tessellation cluster finder in 2+1 dimensions

    SciTech Connect

    Soares-Santos, Marcelle; de Carvalho, Reinaldo R.; Annis, James; Gal, Roy R.; La Barbera, Francesco; Lopes, Paulo A.A.; Wechsler, Risa H.; Busha, Michael T.; Gerke, Brian F.; /SLAC /KIPAC, Menlo Park

    2010-11-01

    We present a detailed description of the Voronoi Tessellation (VT) cluster finder algorithm in 2+1 dimensions, which improves on past implementations of this technique. The need for cluster finder algorithms able to produce reliable cluster catalogs up to redshift 1 or beyond and down to 10{sup 13.5} solar masses is paramount especially in light of upcoming surveys aiming at cosmological constraints from galaxy cluster number counts. We build the VT in photometric redshift shells and use the two-point correlation function of the galaxies in the field to both determine the density threshold for detection of cluster candidates and to establish their significance. This allows us to detect clusters in a self-consistent way without any assumptions about their astrophysical properties. We apply the VT to mock catalogs which extend to redshift 1.4 reproducing the {Lambda}CDM cosmology and the clustering properties observed in the Sloan Digital Sky Survey data. An objective estimate of the cluster selection function in terms of the completeness and purity as a function of mass and redshift is as important as having a reliable cluster finder. We measure these quantities by matching the VT cluster catalog with the mock truth table. We show that the VT can produce a cluster catalog with completeness and purity >80% for the redshift range up to {approx}1 and mass range down to {approx}10{sup 13.5} solar masses.

  7. Spitzer Clusters

    NASA Astrophysics Data System (ADS)

    Krick, Kessica

    This proposal is a specific response to the strategic goal of NASA's research program to "discover how the universe works and explore how the universe evolved into its present form." Towards this goal, we propose to mine the Spitzer archive for all observations of galaxy groups and clusters for the purpose of studying galaxy evolution in clusters, contamination rates for Sunyaev Zeldovich cluster surveys, and to provide a database of Spitzer observed clusters to the broader community. Funding from this proposal will go towards two years of support for a Postdoc to do this work. After searching the Spitzer Heritage Archive, we have found 194 unique galaxy groups and clusters that have data from both the Infrared array camera (IRAC; Fazio et al. 2004) at 3.6 - 8 microns and the multiband imaging photometer for Spitzer (MIPS; Rieke et al. 2004) at 24microns. This large sample will add value beyond the individual datasets because it will be a larger sample of IR clusters than ever before and will have sufficient diversity in mass, redshift, and dynamical state to allow us to differentiate amongst the effects of these cluster properties. An infrared sample is important because it is unaffected by dust extinction while at the same time is an excellent measure of both stellar mass (IRAC wavelengths) and star formation rate (MIPS wavelengths). Additionally, IRAC can be used to differentiate star forming galaxies (SFG) from active galactic nuclei (AGN), due to their different spectral shapes in this wavelength regime. Specifically, we intend to identify SFG and AGN in galaxy groups and clusters. Groups and clusters differ from the field because the galaxy densities are higher, there is a large potential well due mainly to the mass of the dark matter, and there is hot X-ray gas (the intracluster medium; ICM). We will examine the impact of these differences in environment on galaxy formation by comparing cluster properties of AGN and SFG to those in the field. Also, we will

  8. Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Miller, Christopher J. Miller

    2012-03-01

    There are many examples of clustering in astronomy. Stars in our own galaxy are often seen as being gravitationally bound into tight globular or open clusters. The Solar System's Trojan asteroids cluster at the gravitational Langrangian in front of Jupiter’s orbit. On the largest of scales, we find gravitationally bound clusters of galaxies, the Virgo cluster (in the constellation of Virgo at a distance of ˜50 million light years) being a prime nearby example. The Virgo cluster subtends an angle of nearly 8◦ on the sky and is known to contain over a thousand member galaxies. Galaxy clusters play an important role in our understanding of theUniverse. Clusters exist at peaks in the three-dimensional large-scale matter density field. Their sky (2D) locations are easy to detect in astronomical imaging data and their mean galaxy redshifts (redshift is related to the third spatial dimension: distance) are often better (spectroscopically) and cheaper (photometrically) when compared with the entire galaxy population in large sky surveys. Photometric redshift (z) [Photometric techniques use the broad band filter magnitudes of a galaxy to estimate the redshift. Spectroscopic techniques use the galaxy spectra and emission/absorption line features to measure the redshift] determinations of galaxies within clusters are accurate to better than delta_z = 0.05 [7] and when studied as a cluster population, the central galaxies form a line in color-magnitude space (called the the E/S0 ridgeline and visible in Figure 16.3) that contains galaxies with similar stellar populations [15]. The shape of this E/S0 ridgeline enables astronomers to measure the cluster redshift to within delta_z = 0.01 [23]. The most accurate cluster redshift determinations come from spectroscopy of the member galaxies, where only a fraction of the members need to be spectroscopically observed [25,42] to get an accurate redshift to the whole system. If light traces mass in the Universe, then the locations

  9. Star clusters

    NASA Astrophysics Data System (ADS)

    Labhardt, Lukas; Binggeli, Bruno

    Star clusters are at the heart of astronomy, being key objects for our understanding of stellar evolution and galactic structure. Observations with the Hubble Space Telescope and other modern equipment have revealed fascinating new facts about these galactic building blocks. This book provides two comprehensive and up-to-date, pedagogically designed reviews on star clusters by two well-known experts in the field. Bruce Carney presents our current knowledge of the relative and absolute ages of globular clusters and the chemical history of our Galaxy. Bill Harris addresses globular clusters in external galaxies and their use as tracers of galaxy formation and cosmic distance indicators. The book is written for graduate students as well as professionals in astronomy and astrophysics.

  10. Occupational Clusters.

    ERIC Educational Resources Information Center

    Pottawattamie County School System, Council Bluffs, IA.

    The 15 occupational clusters (transportation, fine arts and humanities, communications and media, personal service occupations, construction, hospitality and recreation, health occupations, marine science occupations, consumer and homemaking-related occupations, agribusiness and natural resources, environment, public service, business and office…

  11. Cluster generator

    DOEpatents

    Donchev, Todor I.; Petrov, Ivan G.

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  12. Galaxy formation in Lambda greater than 0 Friedmann models: Consequences for the number counts versus redshift test

    NASA Technical Reports Server (NTRS)

    Martel, Hugo

    1994-01-01

    We study the effect of the cosmological constant Lambda on galaxy formation using a simple spherical top-hat overdensity model. We consider models with Omega(sub 0) = 0.2, lambda(sub 0) = 0, and Omega(sub 0) = 0.2, lambda(sub 0) = 0.8 (where Omega(sub 0) is the density parameter, and lambda(sub 0) identically equal Lambda/3 H(sub 0 exp 2) where H(sub 0) is the Hubble constant). We adjust the initial power spectrum amplitude so that both models reproduce the same large-scale structures. The galaxy formation era in the lambda(sub 0) = 0 model occurs early (z approximately 6) and is very short, whereas in the lambda(sub 0) = 0.8 model the galaxy formation era starts later (z approximately 4), and last much longer, possibly all the way to the present. Consequently, galaxies at low redshift (z less than 1) are significantly more evolved in the lambda(sub 0) = 0 model than in the lambda(sub 0) = 0.8 model. This result implies that previous attempts to determine Lambda using the number counts versus redshift test are probably unreliable.

  13. Significant Differences in Physicochemical Properties of Human Immunoglobulin Kappa and Lambda CDR3 Regions.

    PubMed

    Townsend, Catherine L; Laffy, Julie M J; Wu, Yu-Chang Bryan; Silva O'Hare, Joselli; Martin, Victoria; Kipling, David; Fraternali, Franca; Dunn-Walters, Deborah K

    2016-01-01

    Antibody variable regions are composed of a heavy and a light chain, and in humans, there are two light chain isotypes: kappa and lambda. Despite their importance in receptor editing, the light chain is often overlooked in the antibody literature, with the focus being on the heavy chain complementarity-determining region (CDR)-H3 region. In this paper, we set out to investigate the physicochemical and structural differences between human kappa and lambda light chain CDR regions. We constructed a dataset containing over 29,000 light chain variable region sequences from IgM-transcribing, newly formed B cells isolated from human bone marrow and peripheral blood. We also used a published human naïve dataset to investigate the CDR-H3 properties of heavy chains paired with kappa and lambda light chains and probed the Protein Data Bank to investigate the structural differences between kappa and lambda antibody CDR regions. We found that kappa and lambda light chains have very different CDR physicochemical and structural properties, whereas the heavy chains with which they are paired do not differ significantly. We also observed that the mean CDR3 N nucleotide addition in the kappa, lambda, and heavy chain gene rearrangements are correlated within donors but can differ between donors. This indicates that terminal deoxynucleotidyl transferase may work with differing efficiencies between different people but the same efficiency in the different classes of immunoglobulin chain within one person. We have observed large differences in the physicochemical and structural properties of kappa and lambda light chain CDR regions. This may reflect different roles in the humoral immune response.

  14. RAMAN SCATTERED He II {lambda}4332 IN THE SYMBIOTIC STAR V1016 CYGNI

    SciTech Connect

    Lee, Hee-Won

    2012-05-10

    Raman scattering of He II line photons with atomic hydrogen is important in studying the mass loss processes in many symbiotic stars and a number of young planetary nebulae. We calculate the scattering cross sections and branching ratios associated with the Raman scattered He II {lambda}4332 feature formed through inelastic scattering of He II {lambda}949 with a hydrogen atom. At the line center of He II {lambda}949, the total scattering cross section is computed to be {sigma}{sub tot} = 2.5 Multiplication-Sign 10{sup -22} cm{sup 2}, and the branching ratio into the level 2s is 0.12. We also present a high-resolution spectrum of the symbiotic star V1016 Cygni obtained with the 1.8 m telescope at Mt. Bohyun to investigate the Raman scattering origin of the broad feature blueward of He II {lambda}4338. Based on the atomic calculation, we perform Monte Carlo calculations for the line formation. The scattering region is assumed to be a part of a uniform spherical shell that subtends a solid angle {Delta}{Omega} = {pi} steradian with a neutral column density N{sub HI} = 1.0 x 10{sup 21} cm{sup -2}. By adding a far-UV continuum around He II {lambda}949 normalized by the equivalent width of He II {lambda}949 to be 2.3 Angstrom-Sign , we obtain a good fit for both the Raman scattered He II {lambda}4332 and the broad wings around H{gamma}. Our analysis of the Raman feature blueward of H{gamma} in V1016 Cyg is consistent with the previous study of the Raman features blueward of H{alpha} and H{beta} by Jung and Lee.

  15. Regulation of the switch from early to late bacteriophage lambda DNA replication.

    PubMed

    Baranska, S; Gabig, M; Wegrzyn, A; Konopa, G; Herman-Antosiewicz, A; Hernandez, P; Schvartzman, J B; Helinski, D R; Wegrzyn, G

    2001-03-01

    There are two modes of bacteriophage lambda DNA replication following infection of its host, Escherichia coli. Early after infection, replication occurs according to the theta (theta or circle-to-circle) mode, and is later switched to the sigma (sigma or rolling-circle) mode. It is not known how this switch, occurring at a specific time in the infection cycle, is regulated. Here it is demonstrated that in wild-type cells the replication starting from orilambda proceeds both bidirectionally and unidirectionally, whereas in bacteria devoid of a functional DnaA protein, replication from orilambda is predominantly unidirectional. The regulation of directionality of replication from orilambda is mediated by positive control of lambda p(R) promoter activity by DnaA, since the mode of replication of an artificial lambda replicon bearing the p(tet) promoter instead of p(R) was found to be independent of DnaA function. These findings and results of density-shift experiments suggest that in dnaA mutants infected with lambda, phage DNA replication proceeds predominantly according to the unidirectional theta mechanism and is switched early after infection to the sigma mode. It is proposed that in wild-type E. coli cells infected with lambda, phage DNA replication proceeds according to a bidirectional theta mechanism early after infection due to efficient transcriptional activation of orilambda, stimulated by the host DnaA protein. After a few rounds of this type of replication, the resulting increased copy number of lambda genomic DNA may cause a depletion of free DnaA protein because of its interaction with the multiple DnaA-binding sites in lambda DNA. It is proposed that this may lead to inefficient transcriptional activation of orilambda resulting in unidirectional theta replication followed by sigma type replication.

  16. Significant Differences in Physicochemical Properties of Human Immunoglobulin Kappa and Lambda CDR3 Regions

    PubMed Central

    Townsend, Catherine L.; Laffy, Julie M. J.; Wu, Yu-Chang Bryan; Silva O’Hare, Joselli; Martin, Victoria; Kipling, David; Fraternali, Franca; Dunn-Walters, Deborah K.

    2016-01-01

    Antibody variable regions are composed of a heavy and a light chain, and in humans, there are two light chain isotypes: kappa and lambda. Despite their importance in receptor editing, the light chain is often overlooked in the antibody literature, with the focus being on the heavy chain complementarity-determining region (CDR)-H3 region. In this paper, we set out to investigate the physicochemical and structural differences between human kappa and lambda light chain CDR regions. We constructed a dataset containing over 29,000 light chain variable region sequences from IgM-transcribing, newly formed B cells isolated from human bone marrow and peripheral blood. We also used a published human naïve dataset to investigate the CDR-H3 properties of heavy chains paired with kappa and lambda light chains and probed the Protein Data Bank to investigate the structural differences between kappa and lambda antibody CDR regions. We found that kappa and lambda light chains have very different CDR physicochemical and structural properties, whereas the heavy chains with which they are paired do not differ significantly. We also observed that the mean CDR3 N nucleotide addition in the kappa, lambda, and heavy chain gene rearrangements are correlated within donors but can differ between donors. This indicates that terminal deoxynucleotidyl transferase may work with differing efficiencies between different people but the same efficiency in the different classes of immunoglobulin chain within one person. We have observed large differences in the physicochemical and structural properties of kappa and lambda light chain CDR regions. This may reflect different roles in the humoral immune response. PMID:27729912

  17. The C4 clustering algorithm: Clusters of galaxies in the Sloan Digital Sky Survey

    SciTech Connect

    Miller, Christopher J.; Nichol, Robert; Reichart, Dan; Wechsler, Risa H.; Evrard, August; Annis, James; McKay, Timothy; Bahcall, Neta; Bernardi, Mariangela; Boehringer, Hans; Connolly, Andrew; Goto, Tomo; Kniazev, Alexie; Lamb, Donald; Postman, Marc; Schneider, Donald; Sheth, Ravi; Voges, Wolfgang; /Cerro-Tololo InterAmerican Obs. /Portsmouth U., ICG /North Carolina U. /Chicago U., Astron. Astrophys. Ctr. /Chicago U., EFI /Michigan U. /Fermilab /Princeton U. Observ. /Garching, Max Planck Inst., MPE /Pittsburgh U. /Tokyo U., ICRR /Baltimore, Space Telescope Sci. /Penn State U. /Chicago U. /Stavropol, Astrophys. Observ. /Heidelberg, Max Planck Inst. Astron. /INI, SAO

    2005-03-01

    We present the ''C4 Cluster Catalog'', a new sample of 748 clusters of galaxies identified in the spectroscopic sample of the Second Data Release (DR2) of the Sloan Digital Sky Survey (SDSS). The C4 cluster-finding algorithm identifies clusters as overdensities in a seven-dimensional position and color space, thus minimizing projection effects that have plagued previous optical cluster selection. The present C4 catalog covers {approx}2600 square degrees of sky and ranges in redshift from z = 0.02 to z = 0.17. The mean cluster membership is 36 galaxies (with redshifts) brighter than r = 17.7, but the catalog includes a range of systems, from groups containing 10 members to massive clusters with over 200 cluster members with redshifts. The catalog provides a large number of measured cluster properties including sky location, mean redshift, galaxy membership, summed r-band optical luminosity (L{sub r}), velocity dispersion, as well as quantitative measures of substructure and the surrounding large-scale environment. We use new, multi-color mock SDSS galaxy catalogs, empirically constructed from the {Lambda}CDM Hubble Volume (HV) Sky Survey output, to investigate the sensitivity of the C4 catalog to the various algorithm parameters (detection threshold, choice of passbands and search aperture), as well as to quantify the purity and completeness of the C4 cluster catalog. These mock catalogs indicate that the C4 catalog is {approx_equal}90% complete and 95% pure above M{sub 200} = 1 x 10{sup 14} h{sup -1}M{sub {circle_dot}} and within 0.03 {le} z {le} 0.12. Using the SDSS DR2 data, we show that the C4 algorithm finds 98% of X-ray identified clusters and 90% of Abell clusters within 0.03 {le} z {le} 0.12. Using the mock galaxy catalogs and the full HV dark matter simulations, we show that the L{sub r} of a cluster is a more robust estimator of the halo mass (M{sub 200}) than the galaxy line-of-sight velocity dispersion or the richness of the cluster. However, if we

  18. FUSE Observations of Warm Gas in the Cooling Flow Clusters A1795 and A2597

    NASA Technical Reports Server (NTRS)

    Oegerle, W. R.; Cowie, L.; Davidsen, A.; Hu, E.; Hutchings, J.; Murphy, E.; Sembach, K.; Woodgate, B.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    We present far-ultraviolet spectroscopy of the cores of the massive cooling flow clusters Abell 1795 and 2597 obtained with FUSE. As the intracluster gas cools through 3 x 10(exp 5)K, it should emit strongly in the O VI lambda(lambda)1032,1038 resonance lines. We report the detection of O VI (lambda)1032 emission in A2597, with a line flux of 1.35 +/- 0.35 x 10(exp -15) erg/sq cm s, as well as detection of emission from C III (lambda)977. A marginal detection of C III (lambda)977 emission is also reported for A1795. These observations provide evidence for a direct link between the hot (10(exp 7) K) cooling flow gas and the cool (10(exp 4) K) gas in the optical emission line filaments. Assuming simple cooling flow models, the O VI line flux in A2597 corresponds to a mass deposition rate of approx. 40 solar mass /yr within the central 36 kpc. Emission from O VI (lambda)1032 was not detected in A1795, with an upper limit of 1.5 x 10(exp -15) erg/sq cm s, corresponding to a limit on the mass cooling flow rate of M(28 kpc) less than 28M solar mass/ yr. We have considered several explanations for the lack of detection of O VI emission in A1795 and the weaker than expected flux in A2597, including extinction by dust in the outer cluster, and quenching of thermal conduction by magnetic fields. We conclude that a turbulent mixing model, with some dust extinction, could explain our O VI results while also accounting for the puzzling lack of emission by Fe(sub XVII) in cluster cooling flows.

  19. VLA observations of radio sources in interacting galaxy pairs in poor clusters

    NASA Technical Reports Server (NTRS)

    Batuski, David J.; Hanisch, Robert J.; Burns, Jack O.

    1992-01-01

    Observations of 16 radio sources in interacting galaxies in 14 poor clusters were made using the Very Large Array in the B configuration at lambda of 6 and 2 cm. These sources had been unresolved in earlier observations at lambda of 21 cm, and were chosen as a sample to determine which of three models for radio source formation actually pertains in interacting galaxies. From the analysis of this sample, the starburst model appears most successful, but the 'central monster' model could pertain in some cases.

  20. Evolution of star clusters in a cosmological tidal field

    NASA Astrophysics Data System (ADS)

    Rieder, Steven; Ishiyama, Tomoaki; Langelaan, Paul; Makino, Junichiro; McMillan, Stephen L. W.; Portegies Zwart, Simon

    2013-12-01

    We present a method to couple N-body star cluster simulations to a cosmological tidal field, using AMUSE (Astrophysical Multipurpose Software Environment). We apply this method to star clusters embedded in the CosmoGrid dark matter only Lambda cold dark matter simulation. Our star clusters are born at z = 10 (corresponding to an age of the universe of about 500 Myr) by selecting a dark matter particle and initializing a star cluster with 32 000 stars on its location. We then follow the dynamical evolution of the star cluster within the cosmological environment. We compare the evolution of star clusters in two Milky Way size haloes with a different accretion history. The mass-loss of the star clusters is continuous irrespective of the tidal history of the host halo, but major merger events tend to increase the rate of mass-loss. From the selected two dark matter haloes, the halo that experienced the larger number of mergers tends to drive a smaller mass-loss rate from the embedded star clusters, even though the final masses of both haloes are similar. We identify two families of star clusters: native clusters, which become part of the main halo before its final major merger event, and the immigrant clusters, which are accreted upon or after this event; native clusters tend to evaporate more quickly than immigrant clusters. Accounting for the evolution of the dark matter halo causes immigrant star clusters to retain more mass than when the z = 0 tidal field is taken as a static potential. The reason for this is the weaker tidal field experienced by immigrant star clusters before merging with the larger dark matter halo.

  1. Rifampin-stimulated uv resistance of phage lambda on Escherichia coli K12

    SciTech Connect

    Bronner, C.E.; Fluke, D.J.; Pollard, E.C.

    1983-01-01

    The plaque survival of uv-irradiated phage lambda on excision-proficient E.coli strain AB1157 is greater if the host cells are exposed to rifampin for 10 minutes prior to infection. This repair is accompanied by little or no clear-plaque mutagenesis. Host cells uv-irradiated and incubated for 30 minutes in growth medium prior to treatment with rifampin show some Weigle-reactivation in addition to the repair stimulated by rifampin. Some clear-plaque Weigle-mutagenesis is also observed in the presence of rifampin: however, the amount is less than that seen in the absence of rifampin treatment. In contrast, the uv sensitivity of lambda on strain AB1886, an excision-repair deficient mutant, is unchanged by pre-treating the cells with rifampin, and no Weigle-reactivation is observed. These results suggest that repair of lambda on unirradiated cells in the presence of rifampin is an excision-dependent, error-free phenomenon. Since initiation of replication of lambda DNA requires RNA polymerase, and since rifampin blocks transcription by that polymerase, the effect of rifampin on the survival of lambda may be to delay phage replication, thereby allowing more time for excision repair to operate. 6 figures.

  2. The Protein Interaction Network of Bacteriophage Lambda with Its Host, Escherichia coli

    PubMed Central

    Blasche, Sonja; Wuchty, Stefan; Rajagopala, Seesandra V.

    2013-01-01

    Although most of the 73 open reading frames (ORFs) in bacteriophage λ have been investigated intensively, the function of many genes in host-phage interactions remains poorly understood. Using yeast two-hybrid screens of all lambda ORFs for interactions with its host Escherichia coli, we determined a raw data set of 631 host-phage interactions resulting in a set of 62 high-confidence interactions after multiple rounds of retesting. These links suggest novel regulatory interactions between the E. coli transcriptional network and lambda proteins. Targeted host proteins and genes required for lambda infection are enriched among highly connected proteins, suggesting that bacteriophages resemble interaction patterns of human viruses. Lambda tail proteins interact with both bacterial fimbrial proteins and E. coli proteins homologous to other phage proteins. Lambda appears to dramatically differ from other phages, such as T7, because of its unusually large number of modified and processed proteins, which reduces the number of host-virus interactions detectable by yeast two-hybrid screens. PMID:24049175

  3. Lambda Station: Alternate network path forwarding for production SciDAC applications

    SciTech Connect

    Grigoriev, Maxim; Bobyshev, Andrey; Crawford, Matt; DeMar, Phil; Grigaliunas, Vyto; Moibenko, Alexander; Petravick, Don; Newman, Harvey; Steenberg, Conrad; Thomas, Michael; /Caltech

    2007-09-01

    The LHC era will start very soon, creating immense data volumes capable of demanding allocation of an entire network circuit for task-driven applications. Circuit-based alternate network paths are one solution to meeting the LHC high bandwidth network requirements. The Lambda Station project is aimed at addressing growing requirements for dynamic allocation of alternate network paths. Lambda Station facilitates the rerouting of designated traffic through site LAN infrastructure onto so-called 'high-impact' wide-area networks. The prototype Lambda Station developed with Service Oriented Architecture (SOA) approach in mind will be presented. Lambda Station has been successfully integrated into the production version of the Storage Resource Manager (SRM), and deployed at US CMS Tier1 center at Fermilab, as well as at US-CMS Tier-2 site at Caltech. This paper will discuss experiences using the prototype system with production SciDAC applications for data movement between Fermilab and Caltech. The architecture and design principles of the production version Lambda Station software, currently being implemented as Java based web services, will also be presented in this paper.

  4. Experiments with the High Resolution Kaon Spectrometer at Jlab Hall C and the New Spectroscopy of ^12_Lambda B Hypernuclei

    SciTech Connect

    Tang, Liguang; Chen, Chunhua; Gogami, Toshiyuki; Kawama, Daisuke; Han, Yuncheng; Yuan, Lulin; Matsumura, Akihiko; Okayasu, Yuichi; Seva, Tomislav; Rodriguez, Victor; Baturin, Pavlo; Acha Quimper, Armando; Achenbach, Carsten; Ahmidouch, Abdellah; Albayrak, Ibrahim; Androic, Darko; Asaturyan, Arshak; Asaturyan, Razmik; Ates, Ozgur; Badui, Rafael; Baker, Oliver; Benmokhtar, Fatiha; Boeglin, Werner; Bono, Jason; Bosted, Peter; Brash, Edward; Carter, Philip; Carlini, Roger; Chiba, Atsushi; Christy, Michael; Cole, Leon; Dalton, Mark; Danagoulian, Samuel; Daniel, Aji; De Leo, Raffaele; Dharmawardane, Kahanawita; Doi, Daisuke; Egiyan, Kim; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Fujii, Yu; Furic, Miroslav; Gabrielyan, Marianna; Gan, Liping; Garibaldi, Franco; Gaskell, David; Gasparian, Ashot; Gibson, Edward; Gueye, Paul; Hashimoto, Osamu; Honda, D; Horn, Tanja; Hu, Bitao; Hungerford, Ed; Jayalath, Chandana; Jones, Mark; Johnston, Kathleen; Kalantarians, Narbe; Kanda, Hiroki; Kaneta, M; Kato, F; Kato, Seigo; Kawai, Masaharu; Keppel, Cynthia; Khanal, Hari; Kohl, M; Kramer, Laird; Lan, Kejian; Li, Ya; Habarakada Liyanage, Anusha; Luo, Wei; Mack, David; Maeda, Kazushige; Malace, Simona; Margaryan, Amur; Marikyan, Gagik; Markowitz, Pete; Maruta, Tomofumi; Maruyama, Nayuta; Maxwell, Victor; Millener, David; Miyoshi, Toshinobu; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Motoba, Toshio; Nagao, Sho; Nakamura, Satoshi; Narayan, Amrendra; Neville, Casey; Niculescu, Gabriel; Niculescu, Maria; Nunez, Angel; Nuruzzaman, nfn; Nomura, Hiroshi; Nonaka, Kenichi; Ohtani, Atsushi; Oyamada, Masamichi; Perez, Naipy; Petkovic, Tomislav; Pochodzalla, J; Qiu, Xiyu; Randeniya, Kapugodage; Raue, Brian; Reinhold, Joerg; Rivera, R; Roche, Julie; Samanta, Chhanda; Sato, Yoshinori; Sawatzky, Bradley; Segbefia, Edwin; Schott, Diane; Shichijo, Ayako; Simicevic, Neven; Smith, Gregory; Song, Yushou; Sumihama, Mizuki; Tadevosyan, Vardan; Takahashi, Toshiyuki; Taniya, Naotaka; Tsukada, Kyo; Tvaskis, Vladas; Veilleux, Micah; Vulcan, William; Wells, Steven; Wesselmann, Frank; Wood, Stephen; Yamamoto, Taku; Yan, Chen; Ye, Z; Yokota, Kosuke; Zhamkochyan, Simon; Zhu, Lingyan

    2014-09-01

    Since the pioneering experiment, E89-009 studying hypernuclear spectroscopy using the $(e,e^{\\prime}K^+)$ reaction was completed, two additional experiments, E01-011 and E05-115, were performed at Jefferson Lab. These later experiments used a modified experimental design, the "Tilt Method", to dramatically suppress the large electromagnetic background, and allowed for a substantial increase in luminosity. Additionally, a new kaon spectrometer, HKS (E01-011), a new electron spectrometer, HES, and a new splitting magnet were added to produce precision, high-resolution hypernuclear spectroscopy. These two experiments, E01-011 and E05-115, resulted in two new data sets, producing sub-MeV energy resolution in the spectra of ${}^{7}_{\\Lambda}\\text{He}$, ${}^{12}_{\\Lambda}\\text{B}$ and ${}^{28}_{\\Lambda} \\text{Al}$ and ${}^{7}_{\\Lambda}\\text{He}$, ${}^{10}_{\\Lambda}\\text{Be}$, ${}^{12}_{\\Lambda}\\text{B}$ and ${}^{52}_{\\Lambda}\\text{V}$. All three experiments obtained a ${}^{12}_{\\Lambda}\\text{B}$, spectrum, which is the most characteristic $p$-shell hypernucleus and is commonly used for calibration. Independent analyses of these different experiments demonstrate excellent consistency and provide the clearest level structure to date of this hypernucleus as produced by the $(e,e^{\\prime}K^+)$ reaction. This paper presents details of these experiments, and the extraction and analysis of the observed ${}^{12}_{\\Lambda}\\text{B}$ spectrum.

  5. Quartz Microbalance Study of 400-angstrom Thick Films near the lambda Point

    NASA Technical Reports Server (NTRS)

    Chan, Moses H. W.

    2003-01-01

    In a recent measurement we observed the thinning of an adsorbed helium film induced by the confinement of critical fluctuations a few millikelvin below the lambda point. A capacitor set-up was used to measure this Casimir effect. In this poster we will present our measurement of an adsorbed helium film of 400 angstroms near the lambda point with a quartz microbalance. For films this thick, we must take into account the non-linear dynamics of the shear waves in the fluid. In spite of the added complications, we were able to confirm the thinning of the film due to the Casimir effect and the onset of the superfluid transition. In addition, we observe a sharp anomaly at the bulk lambda point, most likely related to critical dissipation of the first sound. This work is carried out in collaboration with Rafael Garcia, Stephen Jordon and John Lazzaretti. This work is funded by NASA's Office of Biological and Physical Research under grant.

  6. The experimental determination of C lambda using an absorbed dose calorimeter.

    PubMed

    Williams, P C

    1980-01-01

    The absorbed dose conversion factors, C lambda, were introduced, by Greene and Massey, as an interim measure until a primary standard for high energy photon dosimetry could be established. The theoretical basis of these factors has been discussed extensively and a more rigorous definition has emerged. Experiments have been carried out to determine the values of C lambda, for a Tufnol walled, Baldwin-Farmer ionisation chamber over a range of energies from cobalt-60 to 12 MV. The experimental results, based on measurements with a calorimeter, presented here support the more rigorous definition but it is shown that the values obtained depend, to a small extent, on the assumptions made about the detailed construction of the ionisation chamber for which C lambda is measured.

  7. Observation of the Helium 7 {Lambda} hypernucleus by the (e,e'K+) reaction

    SciTech Connect

    Nakamura, Satoshi; Okayasu, Yuichi; Seva, Tomislav; Rodriguez, Victor; Baturin, Pavlo; Yuan, Lulin; Acha Quimper, Armando; Ahmidouch, Abdellah; Androic, Darko; Asaturyan, Arshak; Asaturyan, Razmik; Baker, Oliver; Benmokhtar, Fatiha; Boeglin, Wener; Bosted, Peter; Carlini, Roger; Chen, Chunhua; Christy, Michael; Cole, Leon; Danagoulian, Samuel; Daniel, Aji; Dharmawardane, Kahanawita; Egiyan, Kim; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Fujii, Yu; Furic, Miroslav; Gan, Liping; Gaskell, David; Gasparian, Ashot; Gibson, Edward; Toshiyuki, Gogami; Gueye, Paul; Han, Yuncheng; Hashimoto, Osamu; Hiyama, E; Honda, D; Horn, Tanja; Hu, Bitao; Hungerford, Ed; Jayalath, Chandana; Jones, Mark; Johnston, Kathleen; Kalantarians, Narbe; Kanda, Hiroki; Kaneta, M; Kato, Seigo; Kato, Shigeki; Kawama, Daisuke; Keppel, Cynthia; Kramer, Laird; Lan, Kejian; Luo, Wei; Mack, David; Maeda, Kazushige; Malace, Simona; Margaryan, Amur; Marikyan, Gagik; Markowitz, Pete; Maruta, Tomofumi; Maruyama, Nayuta; Miyoshi, Toshinuobu; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Nagao, Sho; Navasardyan, Tigran; Niculescu, Gabriel; Niculescu, Maria-Ioana; Nonaka, Kenichi; Ohtani, Atsushi; Oyamada, Masamichi; Perez, Naipy; Petkovic, Tomislav; Randeniya, Kapugodage; Raue, Brian; Reinhold, Joerg; Rivera Castillo, Roberto; Roche, Julie; Sato, Yoshinori; Segbefia, Edwin; Simicevic, Neven; Smith, Gregory; Song, Yushou; Sumihama, Mizuki; Tadevosyan, Vardan; Takahashi, Toshiyuki; Tang, Liguang; Tsukada, Kyo; Tvaskis, Vladas; Vulcan, William; Wells, Steven; Wood, Stephen; Yan, Chen; Zhamkochyan, Simon

    2013-01-01

    An experiment with a newly developed high-resolution kaon spectrometer (HKS) and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab (JLab). The ground state of a neutron-rich hypernucleus, He 7 {Lambda}, was observed for the first time with the (e,e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The He 7 {Lambda} binding energy supplies the last missing information of the A=7, T=1 hypernuclear iso-triplet, providing a new input for the charge symmetry breaking (CSB) effect of {Lambda} N potential.

  8. {lambda}NN and {sigma}NN systems at threshold. II. The effect of D waves

    SciTech Connect

    Garcilazo, H.; Valcarce, A.; Fernandez-Carames, T.

    2007-09-15

    Using the two-body interactions obtained from a chiral constituent quark model, we study all {lambda}NN and {sigma}NN states with I=0,1,2 and J=1/2,3/2 at threshold, taking into account all three-body configurations with S and D wave components. We constrain further the limits for the {lambda}N spin-triplet scattering length a{sub 1/2,1}. Using the hypertriton binding energy, we find a narrow interval for the possible values of the {lambda}N spin-singlet scattering length a{sub 1/2,0}. We find that the {sigma}NN system has a quasibound state in the (I,J)=(1,1/2) channel very near threshold with a width of about 2.1 MeV.

  9. Correlated Leading Baryon-antibaryon Production in e+e- to ccbar to Lambda_c+ antiLambda_c- X

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G. /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-08-22

    We present a study of 649 {+-} 35 e{sup +}e{sup -} {yields} c{bar c} events produced at {radical}s {approx} 10.6 GeV containing both a {Lambda}{sub c}{sup +} baryon and a {bar {Lambda}}{sub c}{sup -} antibaryon. The number observed is roughly four times that expected if the leading charmed hadron types are uncorrelated, confirming an observation by the CLEO Collaboration. We find a 2-jet topology in these events but very few additional baryons, demonstrating that the primary c and {bar c} are predominantly contained in a correlated baryon-antibaryon system. In addition to the charmed baryons we observe on average 2.6 {+-} 0.2 charged intermediate mesons, predominantly pions, carrying 65% of the remaining energy.

  10. Azimuthal anisotropy of K(0)(S) and Lambda+Lambda production at midrapidity from Au+Au collisions at sqrt[s(NN)]=130 GeV.

    PubMed

    Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Deng, W S; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

    2002-09-23

    We report STAR results on the azimuthal anisotropy parameter v(2) for strange particles K(0)(S), Lambda, and Lambda at midrapidity in Au+Au collisions at sqrt[s(NN)]=130 GeV at the Relativistic Heavy Ion Collider. The value of v(2) as a function of transverse momentum, p(t), of the produced particle and collision centrality is presented for both particles up to p(t) approximately 3.0 GeV/c. A strong p(t) dependence in v(2) is observed up to 2.0 GeV/c. The v(2) measurement is compared with hydrodynamic model calculations. The physics implications of the p(t) integrated v(2) magnitude as a function of particle mass are also discussed.

  11. Convergence and shear statistics in galaxy clusters as a result of Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Poplavsky, Alexander

    2016-03-01

    In this paper the influence of galaxy cluster halo environment on the deflection properties of its galaxies is investigated. For this purpose circular and elliptical projected cluster haloes obeying Einasto density profiles are modelled in the \\varLambdaCDM cosmological model. By Monte-Carlo simulations external shear and convergence are calculated for random positions of a test galaxy within its cluster. Throughout the simulations the total virial mass, profile concentration and slope parameters are varied both for cluster and its galaxies. The cluster is composed of smooth matter distribution (intergalactic gas and dark matter) and randomly placed galaxies. As a result of multiple simulation runs robust statistical estimations of external shear and convergence are derived for variable cluster characteristics and its redshift. In addition, the models for external shear and convergence are applied for the galaxy lens seen through the cluster IRC-0218.

  12. Phenotyping polyclonal kappa and lambda light chain molecular mass distributions in patient serum using mass spectrometry.

    PubMed

    Barnidge, David R; Dasari, Surendra; Ramirez-Alvarado, Marina; Fontan, Adrian; Willrich, Maria A V; Tschumper, Renee C; Jelinek, Diane F; Snyder, Melissa R; Dispenzieri, Angela; Katzmann, Jerry A; Murray, David L

    2014-11-07

    We previously described a microLC-ESI-Q-TOF MS method for identifying monoclonal immunoglobulins in serum and then tracking them over time using their accurate molecular mass. Here we demonstrate how the same methodology can be used to identify and characterize polyclonal immunoglobulins in serum. We establish that two molecular mass distributions observed by microLC-ESI-Q-TOF MS are from polyclonal kappa and lambda light chains using a combination of theoretical molecular masses from gene sequence data and the analysis of commercially available purified polyclonal IgG kappa and IgG lambda from normal human serum. A linear regression comparison of kappa/lambda ratios for 74 serum samples (25 hypergammaglobulinemia, 24 hypogammaglobulinemia, 25 normal) determined by microflowLC-ESI-Q-TOF MS and immunonephelometry had a slope of 1.37 and a correlation coefficient of 0.639. In addition to providing kappa/lambda ratios, the same microLC-ESI-Q-TOF MS analysis can determine the molecular mass for oligoclonal light chains observed above the polyclonal background in patient samples. In 2 patients with immune disorders and hypergammaglobulinemia, we observed a skewed polyclonal molecular mass distribution which translated into biased kappa/lambda ratios. Mass spectrometry provides a rapid and simple way to combine the polyclonal kappa/lambda light chain abundance ratios with the identification of dominant monoclonal as well as oligoclonal light chain immunoglobulins. We anticipate that this approach to evaluating immunoglobulin light chains will lead to improved understanding of immune deficiencies, autoimmune diseases, and antibody responses.

  13. Dissipation kinetics and assessment of processing factor for chlorpyrifos and lambda-cyhalothrin in cardamom.

    PubMed

    George, Thomas; Beevi, S Naseema; Xavier, George; Kumar, N Pratheesh; George, Jayesh

    2013-06-01

    The dissipation kinetics and method for estimation of residues of chlorpyrifos and lambda-cyhalothrin in cardamom were studied and developed. The limit of detection and limit of quantitation arrived for the compounds were 0.01 and 0.025 μg g(-1), respectively. Gas chromatographic response of chlorpyrifos and lambda-cyhalothrin residues was linear in the range of 0.01-0.50 μg g(-1) and the mean recovery obtained was 97.3 % for chlorpyrifos and 98.9 % for lambda-cyhalothrin with satisfactory relative standard deviation values. The mean initial residues of chlorpyrifos applied at a concentration of 0.05 % in cardamom was 2.5 μg g(-1) and the residue was 8.1 μg g(-1) after processing, with a processing factor of 3.24, while lambda-cyhalothrin when applied at 0.0025 % resulted in initial residues of 1.63 μg g(-1) that magnified to 4.86 μg g(-1) on curing, with a processing factor of 2.98. The half-life of chlorpyrifos was in the range of 5.1-5.24 days while that of lambda-cyhalothrin was in the range of 4.40-4.55 days. The processing factor arrived at in the above experiment lead to the conclusion that the residues of chlorpyrifos got magnified to 3.24-3.68 times and that of lambda-cyhalothrin got magnified to 2.98-3.46 times of initial residues, consequent to loss of weight due to dehydration during curing.

  14. Fate of the insecticide lambda-cyhalothrin in ditch enclosures differing in vegetation density.

    PubMed

    Leistra, Minze; Zweers, Anton J; Warinton, Jacqui S; Crum, Steven J H; Hand, Laurence H; Beltman, Wim H J; Maund, Stephen J

    2004-01-01

    Use of the insecticide lambda-cyhalothrin in agriculture may result in the contamination of water bodies, for example by spray drift. Therefore, the possible exposure of aquatic organisms to this insecticide needs to be evaluated. The exposure of the organisms may be reduced by the strong sorption of the insecticide to organic materials and its susceptibility to hydrolysis at the high pH values in the natural range. In experiments done in May and August, formulated lambda-cyhalothrin was mixed with the water body of enclosures in experimental ditches containing a bottom layer and macrophytes (at different densities) or phytoplankton. Concentrations of lambda-cyhalothrin in the water body and in the sediment layer, and contents in the plant compartment, were measured by gas-liquid chromatography at various times up to 1 week after application. Various water quality parameters were also measured. Concentrations of lambda-cyhalothrin decreased rapidly in the water column: 1 day after application, 24-40% of the dose remained in the water, and by 3 days it had declined to 1.8-6.5%. At the highest plant density, lambda-cyhalothrin residue in the plant compartment reached a maximum of 50% of the dose after 1 day; at intermediate and low plant densities, this maximum was only 3-11% of the dose (after 1-2 days). The percentage of the insecticide in the ditch sediment was 12% or less of the dose and tended to be lower at higher plant densities. Alkaline hydrolysis in the water near the surface of macrophytes and phytoplankton is considered to be the main dissipation process for lambda-cyhalothrin.

  15. Excess production of phage lambda delayed early proteins under conditions supporting high Escherichia coli growth rates.

    PubMed

    Gabig, M; Obuchowski, M; Wegrzyn, A; Szalewska-Pałasz, A; Thomas, M S; Wegrzyn, G

    1998-08-01

    Bacteriophage lambda is unable to lysogenize Escherichia coli hosts harbouring the rpoA341 mutation due to a drastic reduction in transcription from CII-activated lysogenic promoters (pE, pI and paQ). In addition, the level of early transcripts involved in the lytic pathway of lambda development is also decreased in this genetic background due to impaired N-dependent antitermination. Here, it is demonstrated that despite the reduced level of early lytic pL- and pR-derived transcripts, lytic growth of bacteriophage lambda is not affected in rich media. The level of the late lytic, pR-derived transcripts also remains unaffected by the rpoA341 mutation under these conditions. However, it was found that whilst there is no significant difference in the phage burst size in rpoA+ and rpoA341 hosts growing in rich media, phage lambda is not able to produce progeny in the rpoA341 mutant growing in minimal medium, in contrast to otherwise isogenic rpoA+ bacteria. Provision of an excess of the phage replication proteins O and P in trans or overproduction of the antitermination protein N restore the ability of phage lambda to produce progeny in the rpoA341 mutant under the latter conditions. These results suggest that in rich media phage lambda produces some early proteins in excess of that needed for its effective propagation and indicate that replication proteins may be limiting factors for phage lytic growth in poor media.

  16. Rocket spectroscopy of zeta Orionis.

    NASA Technical Reports Server (NTRS)

    Smith, A. M.

    1972-01-01

    Analysis of a spectrum of zeta Ori extending from 922 to 1453 A with approximately 0.8 A resolution recorded at rocket altitudes. All lines used in existing models of stellar atmospheres appear in the recorded spectrum with the exception of those masked by telluric N2 or strong P Cygni-type profiles and by an O V line at 1371.29 A. Fifteen multiplets of subordinate lines have been reliably identified, indicating an approximate range of excitation from 0 to 50 eV. Transitions in C III (1176 A), N III (991 A), N V (1239, 1243 A), O VI (1032, 1038 A), Si IV (1394, 1403 A), S IV (1063, 1074 A), and S VI (933, 944 A) have been observed as P Cygni-type profiles presumably arising in a circumstellar envelope. The degree of ionization, transitions present, and mean radial velocities are all consistent with viewing the envelope as a hot (about 100,000 K), rarefied plasma in which collisional ionization is important. Interstellar lines in C I (1277, 1280 A), C II (1036, 1334 A), N I (1134-1135 A), N I (1200-1201 A), N II (1084-1086 A), O I (1302, 1305 A), Si II (1190, 1193 A), Si II (1260 A), and Si II (1304 A) have been definitely identified. Other transitions in Ar II, S I, C I, and Fe II are tentatively identified. The equivalent width of the L alpha line is found to be 10.4 plus or minus 1.6 A, corresponding to a columnar density of 2.0 plus or minus 0.7 x 10 to the 20th per cu cm.

  17. Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated?

    SciTech Connect

    Oguri, Masamune; Hennawi, Joseph F.; Gladders, Michael D.; Dahle, Haakon; Natarajan, Priyamvada; Dalal, Neal; Koester, Benjamin P.; Sharon, Keren; Bayliss, Matthew

    2009-01-29

    We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed strong lens modeling with weak lensing shear measured from deep Subaru Suprime-cam images. Weak lensing signals are detected at high significance for all four clusters, whose redshifts range from z = 0.28 to 0.64. We demonstrate that adding strong lensing information with known arc redshifts significantly improves constraints on the mass density profile, compared to those obtained from weak lensing alone. While the mass profiles are well fitted by the universal form predicted in N-body simulations of the {Lambda}-dominated cold dark matter model, all four clusters appear to be slightly more centrally concentrated (the concentration parameters c{sub vir} {approx} 8) than theoretical predictions, even after accounting for the bias toward higher concentrations inherent in lensing selected samples. Our results are consistent with previous studies which similarly detected a concentration excess, and increases the total number of clusters studied with the combined strong and weak lensing technique to ten. Combining our sample with previous work, we find that clusters with larger Einstein radii are more anomalously concentrated. We also present a detailed model of the lensing cluster Abell 1703 with constraints from multiple image families, and find the dark matter inner density profile to be cuspy with the slope consistent with -1, in agreement with expectations.

  18. Specific Heat of Helium at Constant Volume along the Lambda Line

    SciTech Connect

    Lipa, J. A.; Nissen, J. A.; Avaloff, D.; Wang, Suwen

    2006-09-07

    We report new measurements of the constant-volume specific heat of helium along the lambda line from 0.15 to 24.4 bars. The pressure in the cell was also recorded as a function of temperature using a gauge with a superconducting readout. This data can be used to convert the results to the constant-pressure specific heat along isobars. The constant-volume data compare well with earlier results and extend the temperature range of the measurements much closer to the lambda line. A preliminary conversion to Cp(T,P) indicates good agreement with universality.

  19. Solution of the symmetric eigenproblem AX=lambda BX by delayed division

    NASA Technical Reports Server (NTRS)

    Thurston, G. A.; Bains, N. J. C.

    1986-01-01

    Delayed division is an iterative method for solving the linear eigenvalue problem AX = lambda BX for a limited number of small eigenvalues and their corresponding eigenvectors. The distinctive feature of the method is the reduction of the problem to an approximate triangular form by systematically dropping quadratic terms in the eigenvalue lambda. The report describes the pivoting strategy in the reduction and the method for preserving symmetry in submatrices at each reduction step. Along with the approximate triangular reduction, the report extends some techniques used in the method of inverse subspace iteration. Examples are included for problems of varying complexity.

  20. Structure of Lambda(1405) and threshold behavior of pi Sigma scattering

    SciTech Connect

    Yoichi Ikeda, Tesuo Hyodo, Daisuke Jido, Hiroyuki Kamano, Toru Sato, Koichi Yazaki

    2011-01-01

    The scattering length and effective range of the pi-Sigma channel are studied in order to characterize the strangeness S = -1 meson-baryon scattering and the Lambda (1405) resonance. We examine various off-shell dependence of the amplitude in dynamical chiral models to evaluate the threshold quantities with the constraint at the KN threshold. We find that the pi-Sigma threshold parameters are important to the structure of the Lambda (1405) resonance and provide further constraints on the subthreshold extrapolation of the KN interaction.

  1. Branching ratios from B{sub s} and {Lambda}{sub b}{sup 0}

    SciTech Connect

    Matthew S. Martin

    2004-05-28

    CDF Run II relative branching ratio measurements for 65 pb{sup -1} of data in the channels B{sub s} {yields} D{sub s}{sup {-+}}{pi}{sup {-+}}, {Lambda} {sub b}{sup 0} {yields} {Lambda}{sub c}{sup {+-}}{pi}{sup {-+}} and B {yields} h{sup +}h{sup -} are presented. Further, an observation of B{sub s} {yields} K{sup {+-}} K{sup {-+}} and a measurement of A{sub CP} are presented.

  2. Formation of Primordial Stars in a Lambda-CDM Universe

    SciTech Connect

    Yoshida, Naoki; Omukai, Kazuyuki; Hernquist, Lars; Abel, Tom; /KIPAC, Menlo Park

    2006-06-09

    Primordial stars are formed from a chemically pristine gas consisting of hydrogen and helium. They are believed to have been born at some early epoch in the history of the Universe and to have enriched the interstellar medium with synthesized heavy elements before the emergence of ordinary stellar populations. We study the formation of the first generation of stars in the standard cold dark matter model. We follow the gravitational collapse and thermal evolution of primordial gas clouds within early cosmic structures using very high-resolution, cosmological hydrodynamic simulations. Our simulation achieves a dynamic range of {approx} 10{sup 10} in length scale. With accurate treatment of atomic and molecular physics, it allows us to study the chemo-thermal evolution of primordial gas clouds to densities up to {rho} {approx} 2 x 10{sup -8}g cm{sup -3} (n{sub H} {approx} 10{sup 16}cm{sup -3}) without assuming any a priori equation of state; a six orders of magnitudes improvement over previous three-dimensional calculations. We implement an extensive chemistry network for hydrogen, helium and deuterium. All the relevant atomic and molecular cooling and heating processes, including cooling by collision-induced continuum emission, are implemented. For calculating optically thick H{sub 2} cooling at high densities, we use the Sobolev method (Sobolev 1960) and evaluate the molecular line opacities for a few hundred lines. We validate the accuracy of the method by performing a spherical collapse test and comparing the results with those of accurate one-dimensional calculations that treat the line radiative transfer problem in a fully self-consistent manner. We then perform a cosmological simulation adopting the standard {Lambda}CDM model. Dense gas clumps are formed at the centers of low mass ({approx} 10{sup 5-6}M{sub {circle_dot}}) dark matter halos at redshifts z {approx} 20, and they collapse gravitationally when the cloud mass exceeds a few hundred solar masses. To

  3. Hematogones With Lambda Light Chain Restriction in a 4-Year-Old Boy With Burkitt Lymphoma: A Potential Diagnostic Pitfall.

    PubMed

    Guillory, Tesha; Li, Shiyong; Bergsagel, Daniel J; Weinzierl, Elizabeth; Bunting, Silvia T

    2016-05-01

    Hematogones are immature normal B cell precursors with a characteristic immunophenotype profile on flow cytometry that typically do not express surface immunoglobulin light chains. In this report, we describe a case in which the hematogones exhibit light chain restriction. Our patient was a 4-year-old boy with a complicated medical history involving treatment for a presumed bilateral Wilms tumor of the kidney that on later resection was diagnosed as Burkitt lymphoma. Flow cytometry analysis of his bone marrow revealed a small distinct population of cells expressing dim cluster of differentiation (CD)10, CD19, CD22, CD38, dim CD58, human leukocyte antigen-D related (HLA-DR), and dim CD45, which are characteristic of hematogones. These cells, however, demonstrated dim surface immunoglobulin lambda light-chain restriction. Molecular study results for immunoglobulin heavy and kappa light-chain gene rearrangements were negative. We present this case to raise awareness of the potential pitfalls of working up bone marrow for involvement by B cell lymphoproliferative disorder.

  4. Cluster bulleticity

    NASA Astrophysics Data System (ADS)

    Massey, Richard; Kitching, Thomas; Nagai, Daisuke

    2011-05-01

    The unique properties of dark matter are revealed during collisions between clusters of galaxies, such as the bullet cluster (1E 0657-56) and baby bullet (MACS J0025-12). These systems provide evidence for an additional, invisible mass in the separation between the distributions of their total mass, measured via gravitational lensing, and their ordinary 'baryonic' matter, measured via its X-ray emission. Unfortunately, the information available from these systems is limited by their rarity. Constraints on the properties of dark matter, such as its interaction cross-section, are therefore restricted by uncertainties in the individual systems' impact velocity, impact parameter and orientation with respect to the line of sight. Here we develop a complementary, statistical measurement in which every piece of substructure falling into every massive cluster is treated as a bullet. We define 'bulleticity' as the mean separation between dark matter and ordinary matter, and we measure the signal in hydrodynamical simulations. The phase space of substructure orbits also exhibits symmetries that provide an equivalent control test. Any detection of bulleticity in real data would indicate a difference in the interaction cross-sections of baryonic and dark matter that may rule out hypotheses of non-particulate dark matter that are otherwise able to model individual systems. A subsequent measurement of bulleticity could constrain the dark matter cross-section. Even with conservative estimates, the existing Hubble Space Telescope archive should yield an independent constraint tighter than that from the bullet cluster. This technique is then trivially extendable to and benefits enormously from larger, future surveys.

  5. Further observations of the lambda 10830 He line in stars and their significance as a measure of stellar activity

    NASA Technical Reports Server (NTRS)

    Zirin, H.

    1975-01-01

    Measurements of the lambda 1030 He line in 198 stars are given along with data on other features in that spectral range. Nearly 80% of all G and K stars show some lambda 10830; of these, half are variable and 1/4 show emission. It was confirmed that lambda 10830 is not found in M stars, is weak in F stars, and is particularly strong in close binaries. The line is found in emission in extremely late M and S stars, along with P gamma, but P gamma is not in emission in G and K stars with lambda 10830 emissions. Variable He emission and Ti I emission are found in the RV Tauri variables R Scuti and U Mon. In R Aqr the Fe XIII coronal line lambda 10747 and a line at lambda 11012 which may be singlet He or La II are found, as well as lambda 10830 and P gamma. The nature of coronas or hot chromospheres in the various stars is discussed. It was concluded that the lambda 10830 intensity must be more or less proportional to the energy deposited in the chromosphere corona by non-thermal processes.

  6. Embryonic stem cell gene targeting using bacteriophage lambda vectors generated by phage-plasmid recombination.

    PubMed Central

    Tsuzuki, T; Rancourt, D E

    1998-01-01

    Targeted mutagenesis is an extremely useful experimental approach in molecular medicine, allowing the generation of specialized animals that are mutant for any gene of interest. Currently the rate determining step in any gene targeting experiment is construction of the targeting vector (TV). In order to streamline gene targeting methods and avoid problems encountered with plasmid TVs, we describe the direct application of lambda phage in targeted mutagenesis. The recombination-proficient phage vector lambda2TK permits generation of TVs by conventional restriction-ligation or recombination-mediated methods. The resulting lambdaTV DNA can then be cleaved with restriction endonucleases to release the bacteriophage arms and can subsequently be electroporated directly into ES cells to yield gene targets. We demonstrate that in vivo phage-plasmid recombination can be used to introduce neo and lacZ - neo mutations into precise positions within a lambda2TK subclone via double crossover recombination. We describe two methods for eliminating single crossover recombinants, spi selection and size restriction, both of which result in phage TVs bearing double crossover insertions. Thus TVs can be easily and quickly generated in bacteriophage without plasmid subcloning and with little genomic sequence or restriction site information. PMID:9461458

  7. Effects of lambda-cyhalothrin on mosquito larvae and predatory aquatic insects.

    PubMed

    Lawler, Sharon P; Dritz, Deborah A; Christiansen, Julie A; Cornel, Anthony J

    2007-03-01

    Agricultural insecticides can affect mosquito production in rice fields by controlling mosquitoes, disrupting biological control or contributing to selection of insecticide resistance. The duration of insecticidal activity of the pyrethroid lambda-cyhalothrin was quantified on predatory insects in rice fields and on three kinds of mosquito larva: a pyrethroid-susceptible strain of Culex tarsalis Coquillet, a pyrethroid-resistant strain of Cx pipiens L. (sensu lato) and non-resistant Cx pipiens s.l. Lambda-cyhalothrin killed most caged, susceptible mosquitoes for up to 21 days. It killed fewer resistant Cx pipiens s.l., but suppressed their survival for over a week. Lambda-cyhalothrin suppressed field populations of predatory insects through day 29. Agricultural use of lambda-cyhalothrin can provide incidental mosquito control. However, the pyrethroid persisted in sediment and gradually decreased in activity, which could contribute to selection of pyrethroid-resistant mosquitoes. Because caged mosquitoes showed good survival before predators recovered, disruption of biological control is possible. It is therefore advisable for growers and mosquito control agencies to communicate about pesticide use.

  8. Structural and dynamical aspects of avoided-crossing resonances in a three-level {Lambda} system

    SciTech Connect

    Lizuain, I.; Echanobe, J.; Ruschhaupt, A.; Muga, J. G.; Steck, D. A.

    2010-12-15

    In a recent publication [Phys. Rev. A 79, 065602 (2009)], it was shown that an avoided-crossing resonance can be defined according to level-structural or dynamical criteria. We propose an experiment to observe the difference between the two definitions in a three-level {Lambda} system using microwave fields coupling hyperfine magnetic sublevels in alkali-metal atoms.

  9. Bone marrow lambda-type light chain crystalline structures associated with multiple myeloma.

    PubMed

    Schvartz, H; Bonhomme, P; Caulet, S; Beorchia, A; Patey, M; Caulet, T

    1985-01-01

    A 58-year-old man showed bone marrow crystalline structures associated with a lambda light chain producing multiple myeloma. Analysis and processing of electron images clearly displayed the periodic structure of the crystals. Immunochemistry suggested that they contained the whole or a fragmented constant portion of immunoglobulin.

  10. Hydroponic Uptake of Atrazine and Lambda-cyhalothrin in Aquatic Macrophytes

    NASA Astrophysics Data System (ADS)

    Bouldin, J. L.; Farris, J. L.; Moore, M. T.; Smith, S.; Cooper, C. M.

    2005-05-01

    Phytoremediation encompasses an array of plant-associated processes known to mitigate contaminants from soil, sediment, and water. Modification of pesticides associated with agricultural runoff includes processes directly associated with aquatic macrophytes in addition to soil geochemical modifications and associated rhizospheric degradation. Remediation attributes of two vegetative species common to agricultural drainages in the Mississippi Delta, USA, were assessed using atrazine and lambda-cyhalothrin. Concentrations used in 8-d hydroponic exposures were calculated using recommended field applications and a 5% runoff model from a 0.65-cm rainfall event on a 2.02-ha field. While greater atrazine uptake was measured in Juncus effusus, greater lambda-cyhalothrin uptake occurred in Ludwigia peploides. Maximum pesticide uptake was reached within 48 h for each exposure and subsequent translocation of pesticides to upper plant biomass occurred in macrophytes exposed to atrazine. Sequestration of 98.2% of lambda-cyhalothrin in roots of L. peploides was measured after 8 d. Translocation of lambda-cyhalothrin in J. effusus resulted in 25.4% of pesticide uptake partitioned to upper plant biomass. These individual macrophyte remediation studies measured species- and pesticide-specific uptake rates, indicating that the seasonality of pesticide applications and macrophyte emergence might interact strongly to enhance mitigation capabilities in edge-of-field conveyance structures.

  11. Low-lying {Lambda} baryons with spin 1/2 in two-flavor lattice QCD

    SciTech Connect

    Takahashi, Toru T.; Oka, Makoto

    2010-02-01

    Low-lying {Lambda} baryons with spin 1/2 are analyzed in full (unquenched) lattice QCD. We construct 2x2 cross correlators from flavor SU(3) octet and singlet baryon operators, and diagonalize them so as to extract information of two low-lying states for each parity. The two-flavor CP-PACS gauge configurations are used, which are generated in the renormalization-group improved gauge action and the O(a)-improved quark action. Three different {beta}'s, {beta}=1.80, 1.95, and 2.10, are employed, whose corresponding lattice spacings are a=0.2150, 0.1555, and 0.1076 fm. For each cutoff, we use four hopping parameters, ({kappa}{sub val},{kappa}{sub sea}), which correspond to the pion masses ranging about from 500 MeV to 1.1 GeV. Results indicate that there are two negative-parity {Lambda} states nearly degenerate at around 1.6 GeV, while no state as low as {Lambda}(1405) is observed. By decomposing the flavor components of each state, we find that the lowest (1st-excited) negative-parity state is dominated by flavor-singlet (flavor-octet) component. We also discuss meson-baryon components of each state, which has drawn considerable attention in the context of multiquark pictures of {Lambda}(1405).

  12. Backbone dynamics of the monomeric lambda repressor denatured state ensemble under nondenaturing conditions.

    PubMed

    Chugha, Preeti; Oas, Terrence G

    2007-02-06

    Oxidizing two native methionine residues predominantly populates the denatured state of monomeric lambda repressor (MetO-lambdaLS) under nondenaturing conditions. NMR was used to characterize the secondary structure and dynamics of MetO-lambdaLS in standard phosphate buffer. 13Calpha and 1Halpha chemical shift indices reveal a region of significant helicity between residues 9 and 29. This helical content is further supported by the observation of medium-range amide NOEs. The remaining residues do not exhibit significant helicity as determined by NMR. We determined 15N relaxation parameters for 64 of 85 residues at 600 and 800 MHz. There are two distinct regions of reduced flexibility, residues 8-32 in the N-terminal third and residues 50-83 in the C-terminal third. The middle third, residues 33-50, has greater flexibility. We have analyzed the amplitude of the backbone motions in terms of the physical properties of the amino acids and conclude that conformational restriction of the backbone MetO-lambdaLS is due to nascent helix formation in the region corresponding to native helix 1. The bulkiness of amino acid residues in the C-terminal third leads to the potential for hydrophobic interactions, which is suggested by chemical exchange detected by the difference in spectral density J(0) at the two static magnetic fields. The more flexible middle region is the result of a predominance of small side chains in this region.

  13. The HKS experiment on Lambda--hypernuclear spectroscopy via electroproduction at JLab

    SciTech Connect

    Tang, Liguang; Yuan, Lulin; Acha Quimper, Armando; Ahmidouch, Abdellah; Androic, Darko; Asaturyan, Arshak; Asaturyan, Razmik; Baker, O.; Baturin, Pavlo; Benmokhtar, Fatiha; Bosted, Peter; Carlini, Roger; Chen, X.; Christy, Michael; Cole, Leon; Danagoulian, Samuel; Daniel, AJI; Dharmawardane, Kahanawita; Egiyan, Kim; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Fujii, Yu; Furic, Miroslav; Gan, Liping; Gaskell, David; Gasparian, Ashot; Gibson, Edward; Gueye, Paul; Halkyard, Rebekah; Hashimoto, Osamu; Hashimoto, Osamu; Honda, D.; Horn, Tanja; Hu, Bitao; Hu, S.; Hungerford, Ed; Ispiryan, Mikayel; Johnston, Kathleen; Jones, Mark; Kalantarians, Narbe; Kaneta, M.; Kato, F.; Kato, Seigo; Kawama, Daisuke; Keppel, Cynthia; Li, Y.; Luo, Wei; Mack, David; Margaryan, Amur; Marikyan, Gagik; Maruyama, Nayuta; Matsumura, Akihiko; Miyoshi, Toshinobu; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Nakamura, Satoshi; Navasardyan, Tigran; Niculescu, Gabriel; Niculescu, Maria-Ioana; Nomura, Hiroshi; Nonaka, Kenichi; Ohtani, Atsushi; Okayasu, Yuichi; Pamela, Priscilla; Perez, Naipy; Petkovic, Tomislav; Randeniya, Kapugodage; Reinhold, Joerg; Rivera Castillo, Roberto; Roche, Julie; Rodriguez, Victor; Sato, Yoshinori; Seva, Tomislav; Simicevic, Neven; Smith, Gregory; Sumihama, Mizuki; Song, Yujun; Tadevosyan, Vardan; Takahashi, Toshiyuki; Tamura, Hirokazu; Tvaskis, Vladas; Vulcan, William; Wang, B.; Wells, Stephen; Wood, Stephen; Yan, Chen; Zamkochian, S.

    2008-06-01

    The HKS (Jlab E01-011) experiment on spectroscopy of Lambda-hypernuclei using (e,e'K+) reaction was successfully carried out in 2005. This paper gives a brief description of the experiment and its technique and shows some of the preliminary spectra that are still under analysis.

  14. Radiative Corrections to Asymmetry Parameter in the {Omega}{sup -{yields}{Lambda}}+K{sup -} Decay

    SciTech Connect

    Queijeiro, A.

    2010-07-29

    We compute the radiative corrections, to first order in the fine structure constant {alpha}, to the asymmetry parameter {alpha}{sub {Omega}}of the {Omega}{sup -{yields}{Lambda}}+K{sup -} decay. We use previous results where Sirlin's procedure is used to separate the radiative corrections into two parts, one independent model contribution and a model dependent one.

  15. Measurement of sigma(Lambda(b)0) / sigma(anti-B 0) x B(Lambda0(b) ---> Lambda+(c) pi-) / B(anti-B0 ---> D+ pi-) in p anti-p collisions at S**(1/2) = 1.96-TeV

    SciTech Connect

    Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, Anthony A.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

    2006-01-01

    The authors present the first observation of the baryon decay {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +} {pi}{sup -} followed by {Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +} in 106 pb{sup -1} p{bar p} collisions at {radical}s = 1.96 TeV in the CDF experiment. IN order to reduce systematic error, the measured rate for {Lambda}{sub b}{sup 0} decay is normalized to the kinematically similar meson decay {bar B}{sup 0} {yields} D{sup +}{pi}{sup -} followed by D{sup +} {yields} {pi}{sup +}K{sup -}{pi}{sup +}. They report the ratio of production cross sections ({sigma}) times the ratio of branching fractions ({Beta}) for the momentum region integrated above p{sub T} > 6 GeV/c and pseudorapidity range |{eta}| < 1.3: {sigma}(p{bar p} {yields} {Lambda}{sub b}{sup 0}X)/{sigma}(p{bar p} {yields} {bar B}{sup 0} X) x {Beta}({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -})/{Beta}({bar B}{sup 0} {yields} D{sup +}{pi}{sup -}) = 0.82 {+-} 0.08(stat) {+-} 0.11(syst) {+-} 0.22 ({Beta}({Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +})).

  16. SPATIALLY RESOLVED SPECTROSCOPY OF THE GLOBULAR CLUSTER RZ 2109 AND THE NATURE OF ITS BLACK HOLE

    SciTech Connect

    Peacock, Mark B.; Zepf, Stephen E.; Kundu, Arunav; Maccarone, Thomas J.; Rhode, Katherine L.; Salzer, John J.; Waters, Christopher Z.; Ciardullo, Robin; Gronwall, Caryl; Stern, Daniel

    2012-11-10

    We present optical Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) spectroscopy of RZ 2109, a globular cluster (GC) in the elliptical galaxy NGC 4472. This GC is notable for hosting an ultraluminous X-ray source as well as associated strong and broad [O III] {lambda}{lambda}4959, 5007 emission. We show that the HST/STIS spectroscopy spatially resolves the [O III] emission in RZ 2109. While we are unable to make a precise determination of the morphology of the emission-line nebula, the best-fitting models all require that the [O III] {lambda}5007 emission has a half-light radius in the range 3-7 pc. The extended nature of the [O III] {lambda}5007 emission is inconsistent with published models that invoke an intermediate-mass black hole origin. It is also inconsistent with the ionization of ejecta from a nova in the cluster. The spatial scale of the nebula could be produced via the photoionization of a strong wind driven from a stellar mass black hole accreting at roughly its Eddington rate.

  17. Functional humanization of an anti-CD16 Fab fragment: obstacles of switching from murine {lambda} to human {lambda} or {kappa} light chains.

    PubMed

    Schlapschy, Martin; Fogarasi, Marton; Gruber, Helga; Gresch, Oliver; Schäfer, Claudia; Aguib, Yasmine; Skerra, Arne

    2009-03-01

    An alphaCD30xalphaCD16 bispecific monoclonal antibody (MAb) was previously shown to induce remission of Hodgkin's disease refractory to chemo- and radiotherapy through specific activation of natural killer (NK) cells, but the appearance of a human anti-mouse antibody (HAMA) response prevented its use for prolonged therapy. Here, we describe an effort to humanize the Fab arm directed against FcgammaRIII (CD16), which-in context with the previously humanized CD30 Fab fragment-provides the necessary component for the design of a clinically useful bispecific antibody. Thus, the CDRs of the anti-CD16 mouse IgG1/lambda MAb A9 were grafted onto human Ig sequences. In a first attempt, the murine V(lambda) domain was converted to a humanized lambda chain, which led, however, to complete loss of antigen-binding activity and extremely poor folding efficiency upon periplasmic expression in Escherichia coli. Hence, its CDRs were transplanted onto a human kappa light chain in a second attempt, which resulted in a functional recombinant Fab fragment, yet with 100-fold decreased antigen affinity. In the next step, an in vitro affinity maturation was performed, wherein random mutations were introduced into the humanized V(H) and V(kappa) domains through error-prone PCR, followed by a filter sandwich colony screening assay for increased binding activity towards the bacterially produced extracellular CD16 fragment. Finally, an optimized Fab fragment was obtained, which carries nine additional amino acid exchanges and exhibits an affinity that is within a factor of 2 identical to that of the original murine A9 Fab fragment. The resulting humanized Fab fragment was fully functional with respect to binding of the recombinant CD16 antigen in enzyme-linked immunosorbent assay and in cytofluorimetry with CD16-positive granulocytes, thus providing a promising starting point for the preparation of a fully human bispecific antibody that permits the therapeutic recruitment of NK cells.

  18. Dynamic processes in Be star atmospheres. 2: He I 2P-nD line formation in lambda Eridani (outburst)

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.; Hubeny, Ivan; Lanz, Thierry; Meylan, Thomas

    1994-01-01

    The He I lambda 6678 line of early Be stars generally shows violet (V) and red (R) emission whenever hydrogen alpha emission is present, but its use as a diagnostic has been handicapped by a poor understanding of the processes that drive it into emission. In an attempt to address this problem we obtained three series of eschelle spectra of the first two members of the singlet and triplet 2P-nD series of lambda Eri (B2e) during 1992 November 3-5 at Kitt Peak. During these observations lambda 6678 showed substantial emission variability in both the wings and central profile, providing an opportunity to compare its behavior with that of the lambda 4922, lambda 5876, and lambda 4471 lines. We found that the responses of the lines were different in several respects. Whereas the emissions in the V wings of all four lines scaled together, the R wing of the lambda 4922 line invariably responded with increased absorption whenever the R wing of lambda 6678 line showed increased emission. These same trends occurred within the central photospheric profiles. The R-wing behavior shows that much, but not all of the emission in lambda 6678 is caused by matter projected against the stellar disk. The excitation temperatures of the neighboring 2(sup 1) P transitions, lambda 6678 and lambda 4922 must be greater than and less than the photospheric continuum temperature, respectively. We have investigated departures from local thermodynamic equilibrium (LTE) for the He I spectrum in a variety of ad hoc, perturbed model atmospheres. We have found only one way to cause the source function of lambda 6678 to increase so strongly, namely, by increasing the atmospheric temperature in the line formation region to 30,000 - 40,000 K. This effect was discovered by Auer and Mihalas for O3-O4 atmospheric models, but it has not been applied to active B stars. Our models suggest that lambda 6678 emission in Be stars can be used as a sensitive monitor of localized hot spots on these stars' surfaces

  19. UBVR{sub c} I{sub c} ANALYSIS OF THE RECENTLY DISCOVERED TOTALLY ECLIPSING EXTREME MASS RATIO BINARY V1853 ORIONIS, AND A STATISTICAL LOOK AT 25 OTHER EXTREME MASS RATIO SOLAR-TYPE CONTACT BINARIES

    SciTech Connect

    Samec, R. G.; Labadorf, C. M.; Hawkins, N. C.; Faulkner, D. R.; Van Hamme, W.

    2011-10-15

    We present precision CCD light curves, a period study, photometrically derived standard magnitudes, and a five-color simultaneous Wilson code solution of the totally eclipsing, yet shallow amplitude (A{sub v} {approx} 0.4 mag) eclipsing, binary V1853 Orionis. It is determined to be an extreme mass ratio, q = 0.20, W-type W UMa overcontact binary. From our standard star observations, we find that the variable is a late-type F spectral-type dwarf, with a secondary component of about 0.24 solar masses (stellar type M5V). Its long eclipse duration (41 minutes) as compared to its period, 0.383 days, attests to the small relative size of the secondary. Furthermore, it has reached a Roche lobe fill-out of {approx}50% of its outer critical lobe as it approaches its final stages of binary star evolution, that of a fast spinning single star. Finally, a summary of about 25 extreme mass ratio solar-type binaries is given.

  20. X-Ray Flare Characteristics in the B2e Star Lambda Eridani (ROSAT)

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.

    1997-01-01

    We document the results of a simultaneous wavelength monitoring on the B2e star (lambda) Eri. This campaign was carried out from ground stations and with the ROSAT, ASCA, IUE, and Voyager 2 space platforms during a week in February-March 1995; a smaller follow-up was conducted in September 1995. During the first of these intervals (lambda) Eri exhibited extraordinary wind and disk-ejection activity. The ROSAT/HRI X-ray light curves showed no large flares such as the one the ROSAT/PSCA observed in 1991. However, possible low level fluctuations in the February-March ROSAT data occurred at the same time as unusual activity in H(alpha) He I (lambda)6678, He II (lambda)1640, and the C IV doublet. For example, the hydrogen and helium lines exhibited an emission in the blue half of their profiles, probably lasting several hours. The C IV lines showed a strong high-velocity Discrete Absorption Component (DAC) accompanied by unusually strong absorption at lower velocities. The helium line activity suggests that a mass ejection occurred at the base of the wind while the strong C III (Voyager) and C IV (IUE) lines implies that shock interactions occurred in the wind flow. It is not clear that the X-ray elevations are directly related to the strong C IV absorptions because the former changed on a much more rapid timescale than absorptions in the C IV lines. Within hours of the mild X-ray flux variations found by ROSAT on February 28, the Voyager UVS observed a "ringing" that decayed over three 3-hr. cycles. The amplitude of these fluctuations was strong (50%) at (lambda)(lambda)950-1100, decreased rapidly with wavelength, and faded to nondetection longward of (lambda)1300. Various considerations indicate that these continuum variations were not due to an instrumental pathology in the UVS. Rather, they appear to be due to a time-dependent flux deficit in the (lambda)(lambda)950-1250 region. We outline a scenario in which a dense plasma structure over the star's surface is

  1. Detection of kappa and lambda light chain monoclonal proteins in human serum: automated immunoassay versus immunofixation electrophoresis.

    PubMed

    Jaskowski, Troy D; Litwin, Christine M; Hill, Harry R

    2006-02-01

    Recently, turbidimetric immunoassays for detecting and quantifying kappa and lambda free light chains (FLC) have become available and are promoted as being more sensitive than immunofixation electrophoresis (IFE) in detecting FLC monoclonal proteins. In this study, we assessed the ability of these turbidimetric assays to detect serum monoclonal proteins involving both free and heavy-chain-bound kappa and lambda light chains compared to standard immunofixation electrophoresis. Sera demonstrating a restricted band of protein migration (other than a definite M spike) by serum protein electrophoresis (SPE), which may represent early monoclonal proteins, were also examined. When compared to IFE, percent agreement, sensitivity, and specificity for the kappa-FLC and lambda-FLC were 94.6, 72.9, and 99.5% and 98.5, 91.4, and 99.7%, respectively, in detecting monoclonal proteins involving free and heavy-chain-bound light chains. The majority of sera (73.7%) demonstrating a restricted band of protein migration on SPE demonstrated abnormal IFE patterns suggestive of multiple myeloma or monoclonal gammopathy of unknown significance, but gave normal kappa/lambda FLC ratios using the turbidimetric immunoassays. In conclusion, the kappa and lambda FLC assays are significantly less sensitive (72.9 to 91.4%) than IFE, but specific in detecting serum monoclonal proteins. Moreover, the kappa/lambda ratio has little value in routine screening since the majority of sera with abnormal IFE patterns had normal kappa/lambda FLC ratios.

  2. {Lambda}-p femtoscopy in collisions of Ar+KCl at 1.76A GeV

    SciTech Connect

    Agakishiev, G.; Destefanis, M.; Gilardi, C.; Kirschner, D.; Kuehn, W.; Lange, J. S.; Metag, V.; Mishra, D.; Pechenova, O.; Spataro, S.; Spruck, B.; Balanda, A.; Dybczak, A.; Michalska, B.; Otwinowski, J.; Przygoda, W.; Salabura, P.; Trebacz, R.; Wisniowski, M.; Wojcik, T.

    2010-08-15

    Results on {Lambda}p femtoscopy are reported at the lowest energy so far. At a beam energy of 1.76A GeV, the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. A high-statistics and high-purity {Lambda} sample was collected, allowing for the investigation of {Lambda}p correlations at low relative momenta. The experimental correlation function is compared to corresponding model calculations allowing the determination of the space-time extent of the {Lambda}p emission source. The {Lambda}p source radius is found to be slightly smaller than the pp correlation radius for a similar collision system. The present {Lambda}p radius is significantly smaller than that found for Au+Au/Pb+Pb collisions in the AGS, SPS, and RHIC energy domains but larger than that observed for electroproduction from He. Taking into account all available data, we find the {Lambda}p source radius to increase almost linearly with the number of participants to the power of one-third.

  3. FORMING REALISTIC LATE-TYPE SPIRALS IN A {Lambda}CDM UNIVERSE: THE ERIS SIMULATION

    SciTech Connect

    Guedes, Javiera; Madau, Piero; Callegari, Simone; Mayer, Lucio

    2011-12-01

    Simulations of the formation of late-type spiral galaxies in a cold dark matter ({Lambda}CDM) universe have traditionally failed to yield realistic candidates. Here we report a new cosmological N-body/smooth particle hydrodynamic simulation of extreme dynamic range in which a close analog of a Milky Way disk galaxy arises naturally. Named 'Eris', the simulation follows the assembly of a galaxy halo of mass M{sub vir} = 7.9 Multiplication-Sign 10{sup 11} M{sub Sun} with a total of N = 18.6 million particles (gas + dark matter + stars) within the final virial radius, and a force resolution of 120 pc. It includes radiative cooling, heating from a cosmic UV field and supernova explosions (blastwave feedback), a star formation recipe based on a high gas density threshold (n{sub SF} = 5 atoms cm{sup -3} rather than the canonical n{sub SF} = 0.1 atoms cm{sup -3}), and neglects any feedback from an active galactic nucleus. Artificial images are generated to correctly compare simulations with observations. At the present epoch, the simulated galaxy has an extended rotationally supported disk with a radial scale length R{sub d} = 2.5 kpc, a gently falling rotation curve with circular velocity at 2.2 disk scale lengths of V{sub 2.2} = 214 km s{sup -1}, an i-band bulge-to-disk ratio B/D = 0.35, and a baryonic mass fraction within the virial radius that is 30% below the cosmic value. The disk is thin, has a typical H I-to-stellar mass ratio, is forming stars in the region of the {Sigma}{sub SFR}-{Sigma}{sub HI} plane occupied by spiral galaxies, and falls on the photometric Tully-Fisher and the stellar-mass-halo-virial-mass relations. Hot (T > 3 Multiplication-Sign 10{sup 5} K) X-ray luminous halo gas makes up only 26% of the universal baryon fraction and follows a 'flattened' density profile {proportional_to}r{sup -1.13} out to r = 100 kpc. Eris appears then to be the first cosmological hydrodynamic simulation in which the galaxy structural properties, the mass budget in the

  4. Hymenoic acid, a novel specific inhibitor of human DNA polymerase lambda from a fungus of Hymenochaetaceae sp.

    PubMed

    Nishida, Masayuki; Ida, Noriko; Horio, Mao; Takeuchi, Toshifumi; Kamisuki, Shinji; Murata, Hiroshi; Kuramochi, Kouji; Sugawara, Fumio; Yoshida, Hiromi; Mizushina, Yoshiyuki

    2008-05-01

    Hymenoic acid (1) is a natural compound isolated from cultures of a fungus, Hymenochaetaceae sp., and this structure was determined by spectroscopic analyses. Compound 1 is a novel sesquiterpene, trans-4-[(1'E,5'S)-5'-carboxy-1'-methyl-1'-hexenyl]cyclohexanecarboxylic acid. This compound selectively inhibited the activity of human DNA polymerase lambda (pol lambda) in vitro, and 50% inhibition was observed at a concentration of 91.7microM. Compound 1 did not influence the activities of the other seven mammalian pols (i.e., pols alpha, gamma, delta, epsilon, eta, iota, and kappa), but also showed no effect even on the activity of pol beta, which is thought to have a very similar three-dimensional structure to the pol beta-like region of pol lambda. This compound also did not inhibit the activities of prokaryotic pols and other DNA metabolic enzymes tested. These results suggested that compound 1 could be a selective inhibitor of eukaryotic pol lambda. This compound had no inhibitory activities against two N-terminal truncated pol lambda, del-1 pol lambda (lacking nuclear localization signal (NLS), BRCA1 C-terminus (BRCT) domain [residues 133-575]), and del-2 pol lambda (lacking NLS, BRCT, domain and proline-rich region [residues 245-575]). The compound 1-induced inhibition of intact pol lambda activity was non-competitive with respect to both the DNA template-primer and the dNTP substrate. On the basis of these results, the pol lambda inhibitory mechanism of compound 1 is discussed.

  5. The Extended Globular Cluster System of NGC3923

    NASA Astrophysics Data System (ADS)

    Ahumada, Tomás; Miller, Bryan; Candlish, Graeme; McGaugh, Stacy S.; Mihos, Chris; Smith, Rory; Puzia, Thomas H.; Taylor, Matthew

    2017-01-01

    In the LambdaCMD paradigm of galaxy formation galaxy halos and their globular clusters systems build up over time by the accretion of small satellites. We can learn about this process in detail by observing systems with ongoing accretion events and comparing the data with simulations. Elliptical shell galaxies are systems that are thought to be due to ongoing or recent minor mergers. We present preliminary results of an investigation of the entire globular cluster system of the shell galaxy NGC3923 from deep DECam g and i-band imaging. Cluster candidates are selected using Principal Component Analysis of Sextractor/PSFEx parameters. We will present the 2D and radial distributions of the globular cluster candidates out to a projected radius of about 130kpc, or 26Re, making this one of the most extended cluster systems studied. We find that the bluer globular cluster candidates have a shallower radial distribution than the red cluster candidates, in agreement with many previous studies.

  6. Probing the dark energy with quasar clustering.

    PubMed

    Calvão, M O; de Mello Neto, J R T; Waga, I

    2002-03-04

    We show through Monte Carlo simulations that the Alcock-Paczyński test, as applied to quasar clustering, is a powerful tool to probe the cosmological density and equation of state parameters Omega(m0), Omega(x0), and w. By taking into account the effect of peculiar velocities upon the correlation function we obtain for the Two-Degree Field QSO Redshift Survey the predicted confidence contours for the cosmological constant (w = -1) and spatially flat (Omega(m0)+Omega(x0) = 1) cases. For w = -1, the test is especially sensitive to the difference Omega(m0)-Omega(Lambda0), thus being ideal to combine with cosmic microwave background results. For the flat case, it is competitive with future supernova and galaxy number count tests, besides being complementary to them.

  7. Rate of degradation of lambda-cyhalothrin and methomyl in grapes (Vitis vinifera L.).

    PubMed

    Banerjee, Kaushik; Upadhyay, Ajay Kumar; Adsule, Pandurang G; Patil, Sangram H; Oulkar, Dasharath P; Jadhav, Deepak R

    2006-10-01

    Rates of degradation of lambda-cyhalothrin and methomyl residues in grape are reported. The dissipation behavior of both insecticides followed first-order rate kinetics with similar patterns at standard and double-dose applications. Residues of lambda-cyhalothrin were lost with pre-harvest intervals (PHI) of 12.0-12.5 and 15.0-15.5 days, corresponding to the applications at 25 and 50 g a.i. ha-1, respectively. In the case of methomyl, residues were lost with PHI of 55.0 and 61.0 days, following applications at 1 and 2 kg a.i. ha-1, respectively. The PHI, recommended on the basis of the experimental results, was shown to be effective in minimizing residue load of these insecticides below their maximum residue limits (MRLs) in vineyard samples.

  8. Second order gravitational effects on CMB temperature anisotropy in {lambda} dominated flat universes

    SciTech Connect

    Tomita, Kenji; Inoue, Kaiki Taro

    2008-05-15

    We study second order gravitational effects of local inhomogeneities on the cosmic microwave background radiation in flat universes with matter and a cosmological constant {lambda}. We find that the general relativistic correction to the Newtonian approximation is negligible at second order provided that the size of the inhomogeneous region is sufficiently smaller than the horizon scale. For a spherically symmetric top-hat type quasilinear perturbation, the first order temperature fluctuation corresponding to the linear integrated Sachs-Wolfe effect is enhanced (suppressed) by the second order one for a compensated void (lump). As a function of redshift of the local inhomogeneity, the second order temperature fluctuations due to evolution of the gravitational potential have a peak before the matter-{lambda} equality epoch for a fixed comoving size and a density contrast. The second order gravitational effects from local quasilinear inhomogeneities at a redshift z{approx}1 may significantly affect the cosmic microwave background.

  9. Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS

    SciTech Connect

    Silvia Niccolai; Marco Mirazita; Patrizia Rossi; Nathan Baltzell; Daniel Carman; Kenneth Hicks; Bryan McKinnon; Tsutomu Mibe; Stepan Stepanyan; David Tedeschi; Gary Adams; Pawel Ambrozewicz; Sergio Pereira; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; H. Bagdasaryan; Nathan Baillie; Jacques Ball; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; S.L. Careccia; Bryan Carnahan; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; V. Crede; John Cummings; Natalya Dashyan; Pavel Degtiarenko; Rita De Masi; Airton Deppman; Enzo De Sanctis; Alexandre Deur; Raffaella De Vita; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; L. El Fassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Kenneth Livingston; H. Lu; Marion MacCormick; Nikolai Markov; Bernhard Mecking; Jonathan Mellor; Joseph Melone; Mac Mestayer; Curtis Meyer; Konstantin Mikhaylov; Ralph Minehart; Rory Miskimen; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Gordon Mutchler; Pawel Nadel-Turonski; James Napolitano; Rakhsha Nasseripour; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Jorge De Olivei Echeimberg; Mikhail Osipenko; Alexander Ostrovidov; K. Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; Barry Preedom; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Stepan Stepanyan; Burnham Stokes; Paul Stoler; Igor Strakovski; Steffen Strauch; Mauro Taiuti; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2006-04-26

    For the first time, the reaction gamma d -> Lambda n K+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Lab, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant mass distribution. The upper limit on the gamma d -> Lambda Theta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.

  10. Cloning of the lambda resistant genes from Brevibacterium albidum and Proteus vulgaris into Escherichia coli.

    PubMed

    Chae, K S; Yoo, O J

    1986-11-14

    Genes from Proteus vulgaris ATCC13315 and Brevibacterium albidum ATCC15831 were introduced into Escherichia coli, which rendered the host resistant to coliphage lambda. The clones transformed by any one of the two recombinant plasmids, pRMG101 or pRMG216, were totally resistant against the infection of virulent lambda and N4, but sensitive to ø80, T4 and T7. However, when maltose transport systems of the clones were induced by maltose, the clones were no more resistant to the phage: thus, this phenotype was thought to be due to the inhibition of phage adsorption onto the cell surface. The gene product was shown by SDS-PAGE of membrane protein-enriched extract of the clone. Molecular weight as measured was about 40,000 dalton, which coincide with that inferred from the nucleotide sequences.

  11. Disappearance of Roton Propagation in Superfluid {sup 4}He at T{sub {lambda}}

    SciTech Connect

    Svensson, E.C.; Montfrooij, W.; de Schepper, I.M.

    1996-11-01

    Using neutron scattering, we determine the dynamic structure factor {ital S}({ital q},{nu}) of liquid {sup 4}He for the roton wave number {ital q}=2.0{sup {minus}1} as a function of frequency {nu} at constant density 0.1715 gcm{sup {minus}3} and for ten temperatures in the range 1.08{le}{ital T}{le}2.00 K, primarily near the superfluid transition temperature {ital T}{sub {lambda}}=1.9202 K. The {lambda} transition is marked by a complete softening of the roton mode and a rapid decrease in lifetime. This change is continuous with temperature, and we find no evidence for a new mode appearing as one enters the superfluid phase, as has been proposed on the basis of theoretical considerations. {copyright} {ital 1996 The American Physical Society.}

  12. HE I lambda4922 in B stars: Comparison of theory and observations

    SciTech Connect

    Heasley, J.N.; Wolfe, S.C.

    1981-05-01

    Profiles of the He I lambda4922 line have been observed in 15 B-type stars with an unintensified Reticon detector on the coude spectrograph of the University of Hawaii's 2.2 m telescope on Mauna Kea. The observations are compared with the theoretical line profiles computed by Mihalas, Barnard, Cooper, and Smith, who used an improved line broadening theory. The results show that the computed profiles reproduce the core and red wing of the stellar profiles, but the forbidden component in the blue wing of the line is deeper and broader than the theoretical predictions. Photographic H..cap alpha.. line profiles have been obtained for three of our program stars, and for this sample we find that the Balmer line, He I lambda4922, and Stroemgren photometric colors yield a consistent set of atmospheric parameters.

  13. K{sup 0} and {lambda} production in Ni+Ni collisions near threshold

    SciTech Connect

    Merschmeyer, M.; Herrmann, N.; Benabderrahmane, M. L.; Cordier, E.; Mangiarotti, A.; Pelte, D.; Xiao, Z. G.; Lopez, X.; Andronic, A.; Hartmann, O. N.; Hildenbrand, K. D.; Koczon, P.; Leifels, Y.; Reisdorf, W.; Schuettauf, A.; Bastid, N.; Crochet, P.; Barret, V.; Dupieux, P.

    2007-08-15

    New results concerning the production of neutral strange particles, K{sup 0} and {lambda} in Ni+Ni collisions at 1.93A GeV, measured with the FOPI detector at GSI Darmstadt, are presented. Rapidity density distributions and Boltzmann slope parameter distributions are measured in nearly the full phase space of the reaction. The observables are compared to existing K{sup +} and proton data. While the K{sup 0} data agree with previously reported K{sup +} measurements, the {lambda} distributions show a different behavior relative to that of protons. The strangeness balance and the production yield per participating nucleon as a function of the centrality of the reaction are discussed, for the first time at GSI Schwerionen Synchrotron (SIS) energies.

  14. Finite-geometry specific-heat scaling function near the lambda transition

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, S.; Bhattacharjee, J. K.

    1998-07-01

    Using a technique due to Nicoll for studying the wave-number dependent specific heat in the bulk geometry, we calculate for temperatures above the lambda point the two-loop specific-heat scaling function for the parallel plate geometry with Dirichlet boundary conditions. We work with the logarithmic specific heat for simplicity, since for the actual superfluid transition the exponent α is very close to zero. The agreement with the recent data is exhibited.

  15. Photospheric Activity in Selected Be STARS: lambda Eri and gamma Cas

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.

    1994-01-01

    Recent observations of rapid variations in optical He I lines, X-rays, and FUV wavelengths in the prototypical classical Be stars lambda Eri and star gamma Cas hint that the violent processes occur on the surfaces of these stars almost all the time. We suggest that of these phenomena show greater similarities with magnetic flaring than any other process through to occur on stars.

  16. Deposition of kappa and lambda light chains in amyloid filaments of dialysis-related amyloidosis.

    PubMed

    Brancaccio, D; Ghiggeri, G M; Braidotti, P; Garberi, A; Gallieni, M; Bellotti, V; Zoni, U; Gusmano, R; Coggi, G

    1995-10-01

    beta 2-Microglobulin (beta 2m) is considered to be the amyloidogenic precursor in dialysis-related amyloidosis, although the implication of other relevant cofactors in the pathogenesis of this disease has also been hypothesized. It is conceivable that substances found in amyloid deposits might represent something more than simple codeposition, possibly playing a pathogenic role in amyloidogenesis. Along these lines, a detailed analysis of the protein composition of amyloid fibrils purified from synovial material surgically obtained from nine patients on long-term dialysis was carried out. By the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, several other protein components, in addition to beta 2m, were found. These were characterized by NH2 amino-terminal sequencing and immunoblotting. In fibrils obtained by water extraction, which fulfill the electron microscopy criteria of highly pure amyloid material, polyclonal kappa and lambda light chains were detected with a concentration of 15 micrograms/mL in the water extraction material; the beta 2m concentration was 200 micrograms/mL. Light microscopy immunohistochemistry was performed on samples from five patients. Amyloid deposits reacted with anti-beta 2m, and anti-light (kappa, lambda), chain antibodies. The immunoreaction of amyloid filaments to anti-beta 2m, anti-lambda, and anti-kappa light chain antibodies was also tested by electron microscopy by use of the immunogold staining procedure. Amyloid filaments were labeled by the three antibodies and showed a different intensity of immunostaining apparently related to their different aggregation pattern. These observations demonstrate that polyclonal immunoglobulin light chains (kappa and lambda) are not contaminants but, together with beta 2m, represent a major constituent of amyloid deposits in dialysis-related osteoarticular amyloidosis, thus indicating their possible role in amyloidogenesis.

  17. An analysis of the openehr archetype semantics based on a typed lambda theory.

    PubMed

    Tatsukawa, Akimichi; Shinohara, Emiko Y; Kawazoe, Yoshimasa; Imai, Takeshi; Ohe, Kazuhiko

    2013-01-01

    The openEHR has adopted the dual model architecture consisting of Reference Model and Archetype. The specification, however, lacks formal definitions of archetype semantics, so that its behaviors have remained ambiguous. The objective of this poster is to analyze semantics of the openEHR archetypes: its variance and mutability. We use a typed lambda calculus as an analyzing tool. As a result, we have reached the conclusion that archetypes should be 1) covariant and 2) immutable schema.

  18. Diquarks and the semileptonic decay of {lambda}{sub b} in the hybrid scheme

    SciTech Connect

    Guo Peng; Ke Hongwei; Li Xueqian; Lue Caidian; Wang Yuming

    2007-03-01

    In this work we use the heavy-quark-light-diquark picture to study the semileptonic decay {lambda}{sub b}{yields}{lambda}{sub c}+l+{nu}{sub l} in the so-called hybrid scheme. Namely, we apply the heavy quark effective theory (HQET) for larger q{sup 2} (corresponding to small recoil), which is the invariant mass square of l+{nu}, whereas the perturbative QCD approach for smaller q{sup 2} to calculate the form factors. The turning point where we require the form factors derived in the two approaches to be connected, is chosen near {rho}{sub cut}=1.1. It is noted that the kinematic parameter {rho} which is usually adopted in the perturbative QCD approach, is in fact exactly the same as the recoil factor {omega}=v{center_dot}v{sup '} used in HQET where v, v{sup '} are the four velocities of {lambda}{sub b} and {lambda}{sub c} respectively. We find that the final result is not very sensitive to the choice, so that it is relatively reliable. Moreover, we apply a proper numerical program within a small range around {rho}{sub cut} to make the connection sufficiently smooth and we parametrize the form factor by fitting the curve gained in the hybrid scheme. The expression and involved parameters can be compared with the ones gained by fitting the experimental data. In this scheme the end-point singularities do not appear at all. The calculated value is satisfactorily consistent with the data which is recently measured by the DELPHI collaboration within 2 standard deviations.

  19. Electroproduction of strangeness on (Lambda)H-3,4 bound states on helium

    SciTech Connect

    F. Dohrmann; D. Abbott; A. Ahmidouch; P. Ambrozewicz; C. S. Armstrong; J. Arrington; R. Asaturyan; K. Assamagan; S. Avery; K. Bailey; S. Beedoe; H. Bitao; H. Breuer; D. S. Brown; R. Carlini; J. Cha; N. Chant; E. Christy; A. Cochran; L. Cole; G. Collins; C. Cothran; J. Crowder; W. J. Cummings; S. Danagoulian; F. Duncan; J. Dunne; D. Dutta; T. Eden; M. Elaasar; R. Ent; L. Ewell; H. Fenker; H. T. Fortune; Y. Fujii; L. Gan; H. Gao; K. Garrow; D. F. Geesaman; P. Gueye; K. Gustafsson; K. Hafidi; J. O. Hansen; W. Hinton; H. E. Jackson; H. Juengst; C. Keppel; A. Klein; D. Koltenuk; Y. Liang; J. H. Liu; A. Lung; D. Mack; R. Madey; P. Markowitz; C. J. Martoff; D. Meekins; J. Mitchell; T. Miyoshi; H. Mkrtchyan; R. Mohring; S. K. Mtingwa; B. Mueller; T. G. O'Neill; G. Niculescu; I. Niculescu; D. Potterveld; J. W. Price; B. A. Raue; P. E. Reimer; J. Reinhold; J. Roche; P. Roos; M. Sarsour; Y. Sato; G. Savage; R. Sawafta; R. E. Segel; A. Yu. Semenov; S. Stepanyan; V. Tadevosian; S. Tajima; L. Tang; B. Terburg; A. Uzzle; S. Wood; H. Yamaguchi; C. Yan; C. Yan; L. Yuan; M. Zeier; B. Zeidman; B. Zihlmann

    2005-05-01

    The A(e,eK+)X reaction has been investigated at Jefferson Laboratory. Data were taken for Q{sup 2} approx. 0.35 GeV{sup 2} at a beam energy of 3.245 GeV for 1H,3He and 4He targets. Evidence for Lambda-hypernuclear bound states is seen for 3,4He targets. This is the first time that the electroproduction of these hypernuclei has been observed.

  20. Topological relationship of prophage lambda to the bacterial chromosome in lysogenic cells.

    PubMed

    Freifelder, D; Meselson, M

    1970-01-01

    X irradiation converts bacterial sex factor DNA covalent circles to more slowly sedimenting forms according to first order kinetics. The rate of conversion is greater for sex factors carrying lambda prophage than it is for nonlysogenized sex factors. The magnitude of the difference and the absence of covalent circular DNA from the product show that the prophage DNA is linearly inserted into the sex factor, as predicted by Campbell's model for lysogenization.

  1. Measurement of the $\\Sigma \\pi$ photoproduction line shapes near the $\\Lambda(1405)$

    SciTech Connect

    Moriya, K; Adhikari, K P; Adikaram, D; Aghasyan, M; Anderson, M D; Anefalos Pereira, S; Ball, J; Baltzell, N A; Battaglieri, M; Batourine, V; Bedlinskiy, I; Bellis, M; Biselli, A S; Bono, J; Boiarinov, S; Briscoe, W J; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Cole, P L; Collins, P; Crede, V; D'Angelo, A; Dashyan, N; De Sanctis, E; De Vita, R; Deur, A; Dey, B; Djalali, C; Doughty, R; Dupre, R; Egiyan, H; El Fassi, L; Eugenio, P; Fedotov, G; Fegan, S; Fersch, R; Fleming, J A; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Griffioen, K A; Guidal, M; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Heddle, D; Hicks, K; Ho, D; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jo, H S; Keller, D; Khandaker, M; Khertarpal, P; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, A; Kubarovsky, V; Kuleshov, S V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, I.J. D; Markov, N; Mayer, M; McCracken, M; McKinnon, B; Mestayer, M D; Meyer, C A; Mirazita, M; Mineeva, T; Mokeev, V; Montgomery, R A; Munevar, E; Munoz Camacho, C; Nadel-Turonski, P; Nasseripour, R; Nepali, C S; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L L; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Phelps, E; Phillips, J J; Pisano, S; Pivnyuk, N; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Rimal, D; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Sabatio, F; Saini, M S; Salgado, C; Schott, D; Seder, E; Seraydaryan, H; Sharabian, Y G; Smith, E S; Smith, G D; Sober, D I; Stepanyan, S S; Stepanyan, S; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tang, W; Taylor, S; Taylor, C E; Tian, Ye; Tkachenko, S; Torayev, B; Ungaro, M; Vernarsky, B; Vlassov, A V; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Weygand, D P

    2013-03-01

    The reaction {gamma} + p -> K{sup +} + {Sigma} + {p}i was used to determine the invariant mass distributions or "line shapes" of the {Sigma}{sup +} {pi}{sup -}, {Sigma}{sup -} {pi}{sup +} and {Sigma}{sup 0} {pi}{sup 0} final states, from threshold at 1328 MeV/c^2 through the mass range of the {Lambda}(1405) and the {Lambda}(1520). The measurements were made with the CLAS system at Jefferson Lab using tagged real photons, for center-of-mass energies 1.95 < W < 2.85 GeV. The three mass distributions differ strongly in the vicinity of the I=0 {Lambda}(1405), indicating the presence of substantial I=1 strength in the reaction. Background contributions to the data from the {Sigma}{sup 0}(1385) and from K* {Sigma} production were studied and shown to have negligible influence. To separate the isospin amplitudes, Breit-Wigner model fits were made that included channel-coupling distortions due to the Nkbar threshold. A best fit to all the data was obtained after including a phenomenological I=1, J{sup P} = 1/2{sup -} amplitude with a centroid at 1394\\pm20 MeV/c^2 and a second I=1 amplitude at 1413\\pm10 MeV/c^2. The centroid of the I=0 {Lambda}(1405) strength was found at the {Sigma} {pi} threshold, with the observed shape determined largely by channel-coupling, leading to an apparent overall peak near 1405 MeV/c^2.

  2. Observation of the decay B0bar -> LambdaC antiproton pi0

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Frascati /INFN, Genoa /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /INFN, Pisa /Princeton U. /Frascati /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2010-08-26

    In a sample of 467 million B{bar B} pairs collected with the BABAR detector at the PEP-II collider at SLAC we have observed the decay {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup 0} and measured the branching fraction to be (1.94 {+-} 0.17 {+-} 0.14 {+-} 0.50) x 10{sup -4}, where the uncertainties are statistical, systematic, and the uncertainty on the {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +} branching fraction, respectively. We determine an upper limit of 1.5 x 10{sup -6} at 90% C.L. for the product branching fraction {Beta}({bar B}{sup 0} {yields} {Sigma}{sub c}{sup +}(2455){bar p}) x {Beta}({Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +}). Furthermore, we observe an enhancement at the threshold of the invariant mass of the baryon-antibaryon pair.

  3. Theory of sub-Doppler cooling of three-level {Lambda} atoms in standing light waves

    SciTech Connect

    Kosachev, D.V.; Rozhdestvenskii, Yu.V.

    1994-12-01

    A general theory of cooling of three-level {Lambda} atoms in two standing light waves between which there is a relative spatial phase shift is presented for arbitrary ratios of the intensity and detuning. It is shown that in the case of equal detuning of the light waves, deep (sub-Doppler) cooling of three-level atoms occurs for any values of the spatial phase shift. For zero spatial phase shift, the atoms are strongly cooled due to coherent population trapping in the given atom-field interaction scheme. On the other hand, for the case of different frequency detunings, sub-Doppler cooling of {Lambda} atoms is possible only with a nonzero relative phase shift; it is shown that this is associated with the so-called {open_quotes}Sisyphus{close_quotes} cooling mechanism. The authors underscore that in their scheme neither a polarization gradient of the exciting waves nor a magnetic field is required to achieve this type of cooling pattern; two standing waves acting on different transitions of a {Lambda} atom are sufficient. 13 refs., 10 figs.

  4. High-speed readout of high-Z pixel detectors with the LAMBDA detector

    NASA Astrophysics Data System (ADS)

    Pennicard, D.; Smoljanin, S.; Sheviakov, I.; Xia, Q.; Rothkirch, A.; Yu, Y.; Struth, B.; Hirsemann, H.; Graafsma, H.

    2014-12-01

    High-frame-rate X-ray pixel detectors make it possible to perform time-resolved experiments at synchrotron beamlines, and to make better use of these sources by shortening experiment times. LAMBDA is a photon-counting hybrid pixel detector based on the Medipix3 chip, designed to combine a small pixel size of 55 μm, a large tileable module design, high speed, and compatibility with ``high-Z'' sensors for hard X-ray detection. This technical paper focuses on LAMBDA's high-speed-readout functionality, which allows a frame rate of 2000 frames per second with no deadtime between successive images. This takes advantage of the Medipix3 chip's ``continuous read-write'' function and highly parallelised readout. The readout electronics serialise this data and send it back to a server PC over two 10 Gigabit Ethernet links. The server PC controls the detector and receives, processes and stores the data using software designed for the Tango control system. As a demonstration of high-speed readout of a high-Z sensor, a GaAs LAMBDA detector was used to make a high-speed X-ray video of a computer fan.

  5. Hierarchy of N-point functions in the {Lambda}CDM and ReBEL cosmologies

    SciTech Connect

    Hellwing, Wojciech A.; Juszkiewicz, Roman; Weygaert, Rien van de

    2010-11-15

    In this work we investigate higher-order statistics for the {Lambda}CDM and ReBEL scalar-interacting dark matter models by analyzing 180h{sup -1} Mpc dark matter N-body simulation ensembles. The N-point correlation functions and the related hierarchical amplitudes, such as skewness and kurtosis, are computed using the counts-in-cells method. Our studies demonstrate that the hierarchical amplitudes S{sub n} of the scalar-interacting dark matter model significantly deviate from the values in the {Lambda}CDM cosmology on scales comparable and smaller than the screening length r{sub s} of a given scalar-interacting model. The corresponding additional forces that enhance the total attractive force exerted on dark matter particles at galaxy scales lower the values of the hierarchical amplitudes S{sub n}. We conclude that hypothetical additional exotic interactions in the dark matter sector should leave detectable markers in the higher-order correlation statistics of the density field. We focused in detail on the redshift evolution of the dark matter field's skewness and kurtosis. From this investigation we find that the deviations from the canonical {Lambda}CDM model introduced by the presence of the 'fifth' force attain a maximum value at redshifts 0.5

  6. Efficacy of alpha-cypermethrin and lambda-cyhalothrin applications to prevent Aedes breeding in tires.

    PubMed

    Pettit, William J; Whelan, Peter I; McDonnell, Joseph; Jacups, Susan P

    2010-12-01

    The efficacy of alpha-cypermethrin (Cyperthor) and lambda-cyhalothrin (Demand) to prevent mosquito larval colonization of water-containing receptacles was investigated using 2 differing applications in disused car tires in Darwin, Australia. Insecticide treatments were applied uniformly to the inside surfaces of 2 categories of tires: 1) dry tires that were partially filled with water 24 h after spraying and 2) wet tires partially filled with water prior to spraying. All mosquito larvae, pupae, and dead adults were collected from the treatment and control tires weekly over the 24-wk study period and were later identified to species in the laboratory. Control tires were colonized by Aedes notoscriptus in wk 2 and by Culex quinquefasciatus in wk 4. Aedes notoscriptus failed to colonize any alpha-cypermethrin-treated tires until wk 22 and did not colonize any lambda-cyhalothrin-treated tires during the 24-wk trial. Culex quinquefasciatus colonized alpha-cypermethrin and lambda-cyhalothrin-treated tires from wk 11 and wk 15, respectively. These results indicate both insecticides using either application method can prevent colonization of Ae. notoscriptus for at least 20 wk and demonstrate great potential for the prevention of breeding in receptacles for other receptacle-breeding Aedes species, such as the dengue vectors, Ae. aegypti and Ae. albopictus.

  7. Differential cross sections for gamma + p --> K^+ + Y for Lambda and Sigma^0 hyperons

    SciTech Connect

    R. Bradford; R.A. Schumacher; J.W.C. McNabb; L. Todor; et. Al.

    2005-09-29

    High-statistics cross sections for the reactions {gamma} + p {yields} K{sup +} + {Lambda} and {gamma} + p {yields} K{sup +} + {Sigma}{sup 0} have been measured using CLAS at Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85 < cos {theta}{sub K{sup +}}{sup c.m.} < +0.95. In the K{sup +}{Lambda} channel we confirm a resonance-like structure near W=1.9 GeV at backward kaon angles. The position and width of this structure change with angle, indicating that more than one resonance is likely playing a role. The K{sup +} {Lambda} channel at forward angles and all energies is well described by a t-channel scaling characteristic of Regge exchange, while the same scaling applied to the K{sup +} {Sigma}{sup 0} channel is less successful. Several existing theoretical models are compared to the data, but none provide a good representation of the results.

  8. Cluster headache

    PubMed Central

    Leroux, Elizabeth; Ducros, Anne

    2008-01-01

    Cluster headache (CH) is a primary headache disease characterized by recurrent short-lasting attacks (15 to 180 minutes) of excruciating unilateral periorbital pain accompanied by ipsilateral autonomic signs (lacrimation, nasal congestion, ptosis, miosis, lid edema, redness of the eye). It affects young adults, predominantly males. Prevalence is estimated at 0.5–1.0/1,000. CH has a circannual and circadian periodicity, attacks being clustered (hence the name) in bouts that can occur during specific months of the year. Alcohol is the only dietary trigger of CH, strong odors (mainly solvents and cigarette smoke) and napping may also trigger CH attacks. During bouts, attacks may happen at precise hours, especially during the night. During the attacks, patients tend to be restless. CH may be episodic or chronic, depending on the presence of remission periods. CH is associated with trigeminovascular activation and neuroendocrine and vegetative disturbances, however, the precise cautive mechanisms remain unknown. Involvement of the hypothalamus (a structure regulating endocrine function and sleep-wake rhythms) has been confirmed, explaining, at least in part, the cyclic aspects of CH. The disease is familial in about 10% of cases. Genetic factors play a role in CH susceptibility, and a causative role has been suggested for the hypocretin receptor gene. Diagnosis is clinical. Differential diagnoses include other primary headache diseases such as migraine, paroxysmal hemicrania and SUNCT syndrome. At present, there is no curative treatment. There are efficient treatments to shorten the painful attacks (acute treatments) and to reduce the number of daily attacks (prophylactic treatments). Acute treatment is based on subcutaneous administration of sumatriptan and high-flow oxygen. Verapamil, lithium, methysergide, prednisone, greater occipital nerve blocks and topiramate may be used for prophylaxis. In refractory cases, deep-brain stimulation of the hypothalamus and

  9. Formation of Cluster Complexes by Cluster-Cluster-Collisions

    NASA Astrophysics Data System (ADS)

    Ichihashi, Masahiko; Odaka, Hideho

    2015-03-01

    Multi-element clusters are interested in their chemical and physical properties, and it is expected that they are utilized as catalysts, for example. Their properties critically depend on the size, composition and atomic ordering, and it should be important to adjust the above parameters for their functionality. One of the ways to form a multi-element cluster is to employ a low-energy collision between clusters. Here, we show characteristic results obtained in the collision between a neutral Ar cluster and a size-selected Co cluster ion. Low-energy collision experiment was accomplished by using a newly developed merging-beam apparatus. Cobalt cluster ions were produced by laser ablation, and mass-selected. On the other hand, argon clusters were prepared by the supersonic expansion of Ar gas. Both cluster beams were merged together in an ion guide, and ionic cluster complexes were mass-analyzed. In the collision of Co2+ and ArN, Co2Arn+ (n = 1 - 30) were observed, and the total intensity of Co2Arn+ (n >= 1) is inversely proportional to the relative velocity between Co2+ and ArN. This suggests that the charge-induced dipole interaction between Co2+ and a neutral Ar cluster is dominant in the formation of the cluster complex, Co2+Arn.

  10. Measurement of the Branching Fractions of the Decays \\bar{B}^0 to Lambda_c^+ \\bar{p} and B^- to Lambda_c^+ \\bar{p} pi^-

    SciTech Connect

    Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G.S.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U., EKP /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Stony Brook /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U.

    2006-12-06

    The authors present studies of two-body and three-body charmed baryonic B decays in a sample of 232 million B{bar B} pairs collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring. The branching fractions of the decays {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p} and B{sup -} {yields} {Lambda}{sub c}{sup +} {bar p}{pi}{sup -} are measured to be (2.15 {+-} 0.36 {+-} 0.13 {+-} 0.56) x 10{sup -5} and (3.53 {+-} 0.18 {+-} 0.31 {+-} 0.92) x 10{sup -4}, respectively. The uncertainties quoted are statistical, systematic, and from the {Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +} branching fraction. They observe a baryon-antibaryon threshold enhancement in the {Lambda}{sub c}{sup +}{bar p} invariant mass spectrum of the three-body mode and measure the ratio of the branching fractions to be {Beta}(B{sup -} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup -})/{Beta}({bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}) = 16.4 {+-} 2.9 {+-} 1.4. These results are preliminary.

  11. Absence of {lambda} immunoglobulin sequences on the supernumerary chromosome of the {open_quotes}cat eye{close_quotes} syndrome

    SciTech Connect

    Hough, C.A.; White, B.N.; Holden, J.J.A.

    1995-09-11

    The supernumerary bisatellited chromosome causing the {open_quotes}cat eye{close_quotes} syndrome (CES) is of chromosome 22 origin and consists of an inverted duplication of the 22pter{r_arrow}22q11.2 region. To determine the extent of involvement of band q11.2 on the bisatellited chromosome, copy number assessment of sequences homologous to cloned {lambda} immunoglobulin ({lambda} Ig) gene region probes was carried out on DNA from individuals with CES using densitometric analysis of Southern blots. None of the 10 {lambda} Ig sequences studied was found in increased copy number in DNA from any of the 10 CES individuals tested, indicating that these sequences are not present on the supernumerary chromosome. The breakpoints involved in the generation of the bisatellited supernumerary chromosome associated with CES are therefore proximal to the {lambda} Ig gene region. 20 refs., 1 fig., 3 tabs.

  12. Utilizing Synthetic Visible Spectra to Explore the Physical Basis for the Classification of Lambda Boötis Stars

    NASA Astrophysics Data System (ADS)

    Cheng, Kwang-Ping; Neff, James E.; Johnson, Dustin M.; Tarbell, Erik S.; Romo, Christopher A.; Gray, Richard O.; Corbally, Christopher J.

    2017-01-01

    Since the peculiar nature of Lambda Boötis was first noticed in 1943, the Lambda Boo stars have been recognized as a group of peculiar A-type stars. They are Population I dwarfs that show deficiencies of iron-peak elements (up to 2 dex), but have near-solar C, N, O, and S abundances. In a previous paper, we used both observed and synthetic ultraviolet spectra to demonstrate that the C i 1657 Å/Al ii 1671 Å equivalent width ratio can help distinguish between Lambda Boo stars and other metal-weak stars hotter than 8000 K. In this paper, using observed and synthetic visible (4000–6800 Å) spectra, we demonstrate that the C i 5052.17 Å/Mg ii 4481 Å equivalent width ratio can be used as a quantitative diagnostic for cooler Lambda Boo stars.

  13. Rearrangement of mouse immunoglobulin kappa deleting element recombining sequence promotes immune tolerance and lambda B cell production.

    PubMed

    Vela, José Luis; Aït-Azzouzene, Djemel; Duong, Bao Hoa; Ota, Takayuki; Nemazee, David

    2008-02-01

    The recombining sequence (RS) of mouse and its human equivalent, the immunoglobulin (Ig) kappa deleting element (IGKDE), are sequences found at the 3' end of the Ig kappa locus (Igk) that rearrange to inactivate Igk in developing B cells. RS recombination correlates with Ig lambda (Iglambda) light (L) chain expression and likely plays a role in receptor editing by eliminating Igk genes encoding autoantibodies. A mouse strain was generated in which the recombination signal of RS was removed, blocking RS-mediated Igk inactivation. In RS mutant mice, receptor editing and self-tolerance were impaired, in some cases leading to autoantibody formation. Surprisingly, mutant mice also made fewer B cells expressing lambda chain, whereas lambda versus kappa isotype exclusion was only modestly affected. These results provide insight into the mechanism of L chain isotype exclusion and indicate that RS has a physiological role in promoting the formation of lambda L chain-expressing B cells.

  14. Measuring the scatter in the cluster optical richness-mass relation with machine learning

    NASA Astrophysics Data System (ADS)

    Boada, Steven Alvaro

    developed previously, we present a pilot survey with integral field spectroscopy of ten galaxy clusters optically selected from the Sloan Digital Sky Survey's DR8 at z = 0.2 - 0.3. Eight of the clusters are rich (lambda > 60) systems with total inferred masses (1.58 -17.37) x1014 M (M 200c), and two are poor (lambda < 15) systems with inferred total masses ˜ 0.5 x 1014 M? (M200c ). We use the Mitchell Spectrograph, (formerly the VIRUS-P spectrograph, a prototype of the HETDEX VIRUS instrument) located on the McDonald Observatory 2.7m telescope, to measure spectroscopic redshifts and line-of-sight velocities of the galaxies in and around each cluster, determine cluster membership and derive LOSVDs. We test both a LOSVD-cluster mass scaling relation and a machine learning based approach to infer total cluster mass. After comparing the cluster mass estimates to the literature, we use these independent cluster mass measurements to estimate the absolute cluster mass scale, and intrinsic scatter in the optical richness-mass relationship. We measure the intrinsic scatter in richness at fixed cluster mass to be sigmaM/lambda = 0.27 +/- 0.07 dex in excellent agreement with previous estimates of sigmaM/lambda ˜ 0.2 - 0.3 dex. We discuss the importance of the data used to train the machine learning methods and suggest various strategies to import the accuracy of the bias (offset) and scatter in the optical richness-cluster mass relation. This demonstrates the power of blind spectroscopic surveys such as HETDEX to provide robust cluster mass estimates which can aid in the determination of cosmological parameters and help to calibrate the observable-mass relation for future photometric large area-sky surveys.

  15. An X-ray Luminous, Distant (z=0.78) Cluster of Galaxies

    NASA Technical Reports Server (NTRS)

    Donahue, Megan

    2001-01-01

    This granted funded ASCA studies of the most X-ray luminous clusters of galaxies in the Extended Medium Sensitivity Survey. These studies leveraged further observations with Chandra and sparked a new collaboration between the PI and John Carlstrom's Sunyaev-Zel'dovich team. The major scientific results due largely or in part from these observations: the first z=0.5-0.8 cluster temperature function, constraints on cluster evolution which showed definitively that the density of the universe divided by the critical density, Omega-m, could not be 1.0, constraints on cluster evolution limiting Omega_m to 0.2-0.5, independent of lambda, the first detections of intracluster iron in a z>0.6 cluster of galaxies. These results are independent of the supernova and cosmological microwave background results, and provide independent constraint on cosmological parameters.

  16. On the theoretical link between LLL-reduction and Lambda-decorrelation

    NASA Astrophysics Data System (ADS)

    Lannes, A.

    2013-04-01

    The LLL algorithm, introduced by Lenstra et al. (Math Ann 261:515-534, 1982), plays a key role in many fields of applied mathematics. In particular, it is used as an effective numerical tool for preconditioning the integer least-squares problems arising in high-precision geodetic positioning and Global Navigation Satellite Systems (GNSS). In 1992, Teunissen developed a method for solving these nearest-lattice point (NLP) problems. This method is referred to as Lambda (for Least-squares AMBiguity Decorrelation Adjustment). The preconditioning stage of Lambda corresponds to its decorrelation algorithm. From an epistemological point of view, the latter was devised through an innovative statistical approach completely independent of the LLL algorithm. Recent papers pointed out some similarities between the LLL algorithm and the Lambda-decorrelation algorithm. We try to clarify this point in the paper. We first introduce a parameter measuring the orthogonality defect of the integer basis in which the NLP problem is solved, the LLL-reduced basis of the LLL algorithm, or the Λ -basis of the Lambda method. With regard to this problem, the potential qualities of these bases can then be compared. The Λ -basis is built by working at the level of the variance-covariance matrix of the float solution, while the LLL-reduced basis is built by working at the level of its inverse. As a general rule, the orthogonality defect of the Λ -basis is greater than that of the corresponding LLL-reduced basis; these bases are however very close to one another. To specify this tight relationship, we present a method that provides the dual LLL-reduced basis of a given Λ -basis. As a consequence of this basic link, all the recent developments made on the LLL algorithm can be applied to the Lambda-decorrelation algorithm. This point is illustrated in a concrete manner: we present a parallel Λ -type decorrelation algorithm derived from the parallel LLL algorithm of Luo and Qiao (Proceedings of

  17. NE VIII lambda 774 and time variable associated absorption in the QSO UM 675

    NASA Technical Reports Server (NTRS)

    Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.

    1995-01-01

    We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the z(sub a) approximately equal z(sub e) absorption system of the z(sub e) = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at z(sub a) = 2.1340 (shifted approximately 1500 km/s from z(sub e) strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other z(sub a) approximately equal z(sub e) absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 10(exp 18)/sq cm in the low-ionization gas to approximately 10(exp 20)/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link z(sub a) approximately equal to z(sub e) systems with X-ray 'wamr absorbers. We show that the

  18. Quantitative Analysis of the Stability of Lysogenic State in Phage lambda

    NASA Astrophysics Data System (ADS)

    Ao, Ping

    2004-03-01

    Based on the recently developed dynamical structure theory for complex networks and the seminal work of Shea and Ackers in the 1980's, we formulate a transparent and concise mathematical framework for the gene regulatory network controlling phage lambda life cycles, which naturally includes the stochastic effect. The dynamical structure theory states that the dynamics of a complex network is determined by its four elementary components: The dissipation (analogous to degradation) and stochastic force, the driving force determined by a potential and the transverse force. The potential may be interpreted as a landscape for the phage development in terms of attractive basins, saddle points, peaks and valleys. The dissipation gives rise to the adaptivity of the phage in the landscape defined by the potential: The phage always has the tendency to approach the bottom of the nearby attractive basin. The stochastic fluctuation gives the phage the ability to search around the potential landscape by passing through saddle points. With molecular parameters in our model fixed primarily by the experimental data on wild type phage and supplemented by data on one mutant, our calculated results on mutants agree quantitatively with the available experimental observations on other mutants for protein number, lysogenization frequency, lysis frequency in lysogen culture. The calculation reproduces the observed robustness of the phage lambda genetic switch. This is the first mathematical description which successfully represents such a wide variety of major experimental phenomena. Specifically we find: 1) The explanation for both the stability and the efficiency of phage lambda switch is the exponential dependence of saddle point crossing rate on potential barrier height, a result of the stochastic motion in a landscape; 2) The positive feedback of CI transcription, enhanced by the CI dimer cooperative binding, is the key to the robustness of the phage lambda genetic switch against

  19. NE VIII lambda 774 and time variable associated absorption in the QSO UM 675

    NASA Astrophysics Data System (ADS)

    Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.

    1995-04-01

    We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the za approximately equal ze absorption system of the ze = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at za = 2.1340 (shifted approximately 1500 km/s from ze strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other za approximately equal ze absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 1018/sq cm in the low-ionization gas to approximately 1020/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link za approximately equal to ze systems with X-ray 'wamr absorbers. We show that the Ne VIII absorbing gas would itself produce measurable warm

  20. Narrow structure in {Lambda}d scattering near the {Sigma} threshold ({sub {Sigma}}{sup 3}He states)

    SciTech Connect

    Gibson, B.F.; Afnan, I.R.

    1991-12-31

    A separable-potential, Faddeev-type calculation of {Lambda}-deuteron scattering near the threshold for {Sigma} production is shown to produce structure (a resonance peak) in the cross section which lies below the {Sigma} threshold for two different YN ({Lambda}N-{Sigma}N coupled-channel) potential models. In one case the {Sigma}NN eigenvalue corresponds to a pole which lies below threshold (bound) and in the second case the poles lies above the threshold.

  1. Science Archives in the 21st Century: A NASA LAMBDA Report

    NASA Technical Reports Server (NTRS)

    Butterworth, P.; Greason, M.

    2007-01-01

    Lambda is a thematic data center that focuses on serving the cosmic microwave background (CMB) research community. LAMBDA is an active archive for NASA's Cosmic Background Explorer (COBE) and Wilkinson Microwave Anisotropy Probe (WMAP) mission data sets. In addition, LAMBDA provides analysis software, on-line tools, relevant ancillary data and important web links. LAMBDA also tries to preserve the most important ground-based and suborbital CMB data sets. CMB data is unlike other astrophysical data, consisting of intrinsically diffuse surface brightness photometry with a signal contrast of the order 1 part in 100,000 relative to the uniform background. Because of the extremely faint signal levels, the signal-to-noise ratio is relatively low and detailed instrument-specific knowledge of the data is essential. While the number of data sets being produced is not especially large, those data sets are becoming large and complex. That tendency will increase when the many polarization experiments currently being deployed begin producing data. The LAMBDA experience supports many aspects of the NASA data archive model developed informally over the last ten years-that small focused data centers are often more effective than larger more ambitious collections, for example; that data centers are usually best run by active scientists; that it can be particularly advantageous if those scientists are leaders in the use of the archived data sets; etc. LAMBDA has done some things so well that they might provide lessons for other archives. A lot of effort has been devoted to developing a simple and consistent interface to data sets, for example; and serving all the documentation required via simple 'more' pages and longer explanatory supplements. Many of the problems faced by LAMBDA will also not surprise anyone trying to manage other space science data. These range from persuading mission scientists to provide their data as quickly as possible, to dealing with a high volume of

  2. SEARCHING FOR COOLING SIGNATURES IN STRONG LENSING GALAXY CLUSTERS: EVIDENCE AGAINST BARYONS SHAPING THE MATTER DISTRIBUTION IN CLUSTER CORES

    SciTech Connect

    Blanchard, Peter K.; Bayliss, Matthew B.; McDonald, Michael; Dahle, Hakon; Gladders, Michael D.; Sharon, Keren; Mushotzky, Richard

    2013-07-20

    The process by which the mass density profile of certain galaxy clusters becomes centrally concentrated enough to produce high strong lensing (SL) cross-sections is not well understood. It has been suggested that the baryonic condensation of the intracluster medium (ICM) due to cooling may drag dark matter to the cores and thus steepen the profile. In this work, we search for evidence of ongoing ICM cooling in the first large, well-defined sample of SL selected galaxy clusters in the range 0.1 < z < 0.6. Based on known correlations between the ICM cooling rate and both optical emission line luminosity and star formation, we measure, for a sample of 89 SL clusters, the fraction of clusters that have [O II]{lambda}{lambda}3727 emission in their brightest cluster galaxy (BCG). We find that the fraction of line-emitting BCGs is constant as a function of redshift for z > 0.2 and shows no statistically significant deviation from the total cluster population. Specific star formation rates, as traced by the strength of the 4000 A break, D{sub 4000}, are also consistent with the general cluster population. Finally, we use optical imaging of the SL clusters to measure the angular separation, R{sub arc}, between the arc and the center of mass of each lensing cluster in our sample and test for evidence of changing [O II] emission and D{sub 4000} as a function of R{sub arc}, a proxy observable for SL cross-sections. D{sub 4000} is constant with all values of R{sub arc}, and the [O II] emission fractions show no dependence on R{sub arc} for R{sub arc} > 10'' and only very marginal evidence of increased weak [O II] emission for systems with R{sub arc} < 10''. These results argue against the ability of baryonic cooling associated with cool core activity in the cores of galaxy clusters to strongly modify the underlying dark matter potential, leading to an increase in SL cross-sections.

  3. The criteria weight determination of factors impacting the melt flow index of degradable plastics using Lambda-Max method

    NASA Astrophysics Data System (ADS)

    Dom, Rosma Mohd; Saadon, Nurul Adzlyana; Mohamad, Daud

    2013-09-01

    Three common methods of determining criteria weights using the Analytic Hierarchy Process (AHP) are extent analysis, logarithmic least square method (LLSM) and Lambda-Max. Lambda-Max criteria weights determination method uses pair wise comparison of criteria considered. Studies have shown that Lambda-Max is a preferred criteria weight determination method since it involves lesser computation with consistent results of precise criteria weights generated. In this paper the criteria weights of four factors impacting the Melt Flow Index of degradable plastics are calculated using Lambda-Max method. The input factors (criteria) are the percentages by mass of polyethylene, oil palm biomass, palm olein and starch used in the formulation of degradable plastics. The criteria weights are calculated using Lambda-Max based on input given by four experts. The finding indicates the feasibility of using Lambda-Max method in criteria weight determination for determining the impact of four factors in the formulation of degradable plastics as reflected by the consistency control index value calculated.

  4. Cosmological Constraints from the SDSS maxBCG Cluster Catalog

    SciTech Connect

    Rozo, Eduardo; Wechsler, Risa H.; Rykoff, Eli S.; Annis, James T.; Becker, Matthew R.; Evrard, August E.; Frieman, Joshua A.; Hansen, Sarah M.; Hao, Jia; Johnston, David E.; Koester, Benjamin P.; McKay, Timothy A.; Sheldon, Erin S.; Weinberg, David H.; /CCAPP /Ohio State U.

    2009-08-03

    We use the abundance and weak lensing mass measurements of the SDSS maxBCG cluster catalog to simultaneously constrain cosmology and the richness-mass relation of the clusters. Assuming a flat {Lambda}CDM cosmology, we find {sigma}{sub 8}({Omega}{sub m}/0.25){sup 0.41} = 0.832 {+-} 0.033 after marginalization over all systematics. In common with previous studies, our error budget is dominated by systematic uncertainties, the primary two being the absolute mass scale of the weak lensing masses of the maxBCG clusters, and uncertainty in the scatter of the richness-mass relation. Our constraints are fully consistent with the WMAP five-year data, and in a joint analysis we find {sigma}{sub 8} = 0.807 {+-} 0.020 and {Omega}{sub m} = 0.265 {+-} 0.016, an improvement of nearly a factor of two relative to WMAP5 alone. Our results are also in excellent agreement with and comparable in precision to the latest cosmological constraints from X-ray cluster abundances. The remarkable consistency among these results demonstrates that cluster abundance constraints are not only tight but also robust, and highlight the power of optically-selected cluster samples to produce precision constraints on cosmological parameters.

  5. THE SLOAN BRIGHT ARCS SURVEY: TEN STRONG GRAVITATIONAL LENSING CLUSTERS AND EVIDENCE OF OVERCONCENTRATION

    SciTech Connect

    Wiesner, Matthew P.; Lin, Huan; Allam, Sahar S.; Annis, James; Buckley-Geer, Elizabeth J.; Diehl, H. Thomas; Kubik, Donna; Kubo, Jeffrey M.; Tucker, Douglas

    2012-12-10

    We describe 10 strong lensing galaxy clusters of redshift 0.26 {<=} z {<=} 0.56 that were found in the Sloan Digital Sky Survey. We present measurements of richness (N{sub 200}), mass (M{sub 200}), and velocity dispersion for the clusters. We find that in order to use the mass-richness relation from Johnston et al., which was established at mean redshift of 0.25, it is necessary to scale measured richness values up by 1.47. Using this scaling, we find richness values for these clusters to be in the range of 22 {<=} N{sub 200} {<=} 317 and mass values to be in the range of 1 Multiplication-Sign 10{sup 14} h {sup -1} M{sub Sun} {<=} M{sub 200} {<=} 30 Multiplication-Sign 10{sup 14} h {sup -1} M{sub Sun }. We also present measurements of Einstein radius, mass, and velocity dispersion for the lensing systems. The Einstein radii ({theta}{sub E}) are all relatively small, with 5.''4 {<=} {theta}{sub E} {<=} 13''. Finally, we consider if there is evidence that our clusters are more concentrated than {Lambda}CDM would predict. We find that six of our clusters do not show evidence of overconcentration, while four of our clusters do. We note a correlation between overconcentration and mass, as the four clusters showing evidence of overconcentration are all lower-mass clusters. For the four lowest mass clusters the average value of the concentration parameter c{sub 200} is 11.6, while for the six higher-mass clusters the average value of c{sub 200} is 4.4. {Lambda}CDM would place c{sub 200} between 3.4 and 5.7.

  6. Is it possible to observationally distinguish adiabatic quartessence from {lambda}CDM?

    SciTech Connect

    Amendola, L.; Reis, R. R. R.; Waga, I.

    2006-09-15

    The equation of state (EOS) in quartessence models interpolates between two stages: p{approx_equal}0 at high energy densities and p{approx_equal}-{rho} at small ones. In the quartessence models analyzed up to now, the EOS is convex, implying increasing adiabatic sound speed (c{sub s}{sup 2}) as the energy density decreases in an expanding universe. A nonnegligible c{sub s}{sup 2} at recent times is the source of the matter power spectrum problem that plagued all convex (nonsilent) quartessence models. Viability for these cosmologies is only possible in the limit of almost perfect mimicry to {lambda}CDM. In this work we investigate if similarity to {lambda}CDM is also required in the class of quartessence models whose EOS changes concavity as the Universe evolves. We focus our analysis in the simple case in which the EOS has a steplike shape, such that at very early times p{approx_equal}0, and at late times p{approx_equal}const<0. For this class of models a nonnegligible c{sub s}{sup 2} is a transient phenomenon and could be relevant only at a more early epoch. We show that agreement with a large set of cosmological data requires that the transition between these two asymptotic states would have occurred at high redshift (z{sub t} > or approx. 38). This leads us to conjecture that the cosmic expansion history of any successful nonsilent quartessence is (practically) identical to the {lambda}CDM one.

  7. The effect of confinement on liquid helium near the lambda line

    SciTech Connect

    Larson, M.E.

    1993-12-31

    This thesis is the compilation of several projects relevant to the behavior of confined liquid helium near the {lambda}-line. The first project described is the development of two new high resolution thermometers optimized for specific heat studies of helium confined in pores. One of the thermometers is a superconductive transition thermometer (STT). The STT has a temperature resolution of about 5nK. The other high resolution thermometer described is a magnetic susceptibility thermometer. This thermometer measures the magnetization of copper ammonium bromide (CAB) using a SQUID magnetometer. The CAB thermometer has an observed sensitivity of about 20nK. Suggestions for improvements in both thermometers are made. Simulation work on the temperature profile of a thermal conductivity cell near T{lambda} is described. The simulations are compared with the experimental results, and a careful study of the stability of the numerics is described. The study of helium confined into pores and films is described next. Both previous theoretical and experimental work on finite size effects in liquid helium are described. The geometry provided by glass capillary arrays is analyzed to determine what would be observed when the specific heat of helium confined to the arrays is measured. Finally, I describe my measurements of the isobaric thermal expansion coefficient {beta}{sub P} of 4He confined in an aerogel for several isobars along the {lambda}-line. {beta}{sub P} is an asymptotically linear function of C{sub P} near the superfluid transition temperature {Tc}. Therefore, fits to power laws in t {triple_bond} T/{Tc} - 1 give the specific heat exponents {alpha} and {alpha}{prime} and amplitude ratio A{prime}/A. Such fits gave different exponents {alpha} {approx} -0.6 and {alpha}{prime} {approx} -1.0 above and below {Tc}.

  8. Synthesis of two-dimensional human walking: a test of the lambda-model.

    PubMed

    Günther, Michael; Ruder, Hanns

    2003-08-01

    To test the lambda-model version of the equilibrium point hypothesis both for feasibility and validity with respect to the control of terrestrial locomotion, we developed a two-dimensional, eleven-segment musculoskeletal model of the human body including 14 muscle-tendon complexes per leg, three-segment feet, and a physiologically based model of foot-ground interaction. Human walking was synthesized by numerical integration of the coupled muscle-tendon and rigid body dynamics. To this end a control algorithm based on the lambda-model was implemented in the model providing muscle stimulation patterns that guaranteed dynamically stable walking including a balanced trunk. Thus, the timing of the movement is not preset by a central pattern generator but emerges from the interaction of the musculoskeletal system with the control algorithm. The control parameters were found in a trial-and-error approach. The feedforward part of the control scheme consists of just two target configurations each of which is composed of a set of one nominal length per muscle (lambda-model). Variation of gravity reveals that (1) the synthesized walking patterns are close to ballistic walking and (2) this muscularly induced natural walking can only be initiated and maintained in the range between about a tenth and three times earth-bound gravity. Our walking patterns are robust both against parameter variations and shuffling of the swing leg. We discuss our model with respect to gravity scaling, speed control, feedback delay, and the terms "equilibrium point hypothesis" and "central pattern generator."

  9. Neutral kaon and lambda production in electron-positron annihilation at 29 GeV and the Z boson resonance

    SciTech Connect

    Fordham, C.S.

    1990-10-01

    The production of K{sup 0} and {Lambda} in the hadronization of q{bar q} events from e{sup +}e{sup {minus}} collisions at 29 GeV and the Z{sup 0} resonance is studied using the Mark II detector as upgraded for running at the Stanford Linear Collider. Hadronization processes cannot presently be calculated with Quantum Chromodynamics; instead, hadronization models must be used in comparisons with data. In these models, hadronization occurs at local energy scales of a few GeV, a level at which small differences in quark and diquark mass significantly affect the production of particles such as K{sup 0} and {Lambda}, the lightest neutral meson and baryon containing strange quarks. Their production and behavior in hadronic events is a test for the accuracy of our understanding of hadronization. Two-charged- particle decays of the K{sup 0} and {Lambda} are isolated within the hadronic event sample. The resulting distribution of K{sup 0} and {Lambda} are corrected for inefficiencies and generalized to include all K{sup 0} and {Lambda}. Various kinematic distributions of the strange particles are examined. These distributions include the momentum and scaled momentum of the particles. The kinematics of the particles with respect to the original quark direction are examined through the distributions of rapidity and momentum transverse to the thrust both in and out of the event plane. The dependence of K{sup 0} and {Lambda} production on the sphericity of the hadronic events is also examined. All these distributions show that the behavior of K{sup 0} and {Lambda} in hadronic events is consistent with the hadronization models.

  10. The pharmacokinetics of peginterferon lambda-1a following single dose administration to subjects with impaired renal function

    PubMed Central

    Hruska, Matthew W; Adamczyk, Robert; Colston, Elizabeth; Hesney, Michael; Stonier, Michele; Myler, Heather; Bertz, Richard

    2015-01-01

    Aims This open label study was conducted to assess the effect of renal impairment (RI) on the pharmacokinetics (PK) of peginterferon lambda-1a (Lambda). Methods Subjects (age 18–75 years, BMI 18–35 kg m–2) were enrolled into one of five renal function groups: normal (n = 12), mild RI (n = 8), moderate RI (n = 8), severe RI (n = 7), end-stage renal disease (ESRD, n = 8) based on estimated glomerular filtration rate (eGFR) calculated using the Modification of Diet in Renal Disease (MDRD) equation. Subjects received a single dose of Lambda (180 µg) subcutaneously on day 1 followed by PK serum sample collections through day 29. Safety, tolerability and immunogenicity data were collected through day 43. PK parameters were estimated and summarized by group. Geometric mean ratios (GMR) and 90% confidence intervals (CIs) were calculated between normal and RI groups. Results With decreasing eGFR, Lambda exposure (Cmax, AUC) increased while apparent clearance (CL/F) and apparent volume of distribution (V/F) decreased. Relative to subjects with normal renal function (geometric mean AUC = 99.5 ng ml–1 h), Lambda exposure estimates (AUC) were slightly increased in the mild RI group (geometric mean [90% CI]: 1.20 [0.82, 1.77]) and greater in the moderate (1.95 [1.35, 2.83]), severe RI (1.95 [1.30, 2.93]) and ESRD (1.88 [1.30, 2.73]) groups. Lambda was generally well tolerated. Conclusions The results demonstrated that RI reduces the clearance of Lambda and suggests that dose modifications may not be required in patients with mild RI but may be required in patients with moderate to severe RI or ESRD. PMID:25807956

  11. Lambda light chain myeloma presenting as nodular hepatic lesion: a clinical rarity.

    PubMed

    Pal, Santanu; Chattopadhyay, Bitoti; Chatterjee, Atri; Bhattacharya, Biswamit

    2014-01-01

    We report a case of a 63-year-old lady presenting with pain in the right hypochondrium, jaundice, anorexia, and firm tender hepatomegaly with remarkably high serum alkaline phosphatase. Abdominal ultrasonography revealed a hypoechoic solid space-occupying lesion in right lobe of liver which was cytologically diagnosed as hepatic plasmacytoma. Serum and urine immunofixation electrophoresis, serum free light chain ratio, and bone marrow examination further confirmed the presence of lambda light chain multiple myeloma in the background. The patient achieved complete remission after four cycles of induction therapy with thalidomide and dexamethasone protocol and consolidated with further four cycles of the same regimen.

  12. Systemic lambda light-chain deposition presenting with predominant cardiac involvement.

    PubMed Central

    Garton, M. J.; Walton, S.; Ewen, S. W.

    1993-01-01

    An 82 year old woman with suspected Bence Jones myeloma developed intractable fluid retention presumed secondary to cardiac failure. In addition she experienced angina pectoris, and required permanent cardiac pacing for symptomatic sinus bradycardia. Postmortem studies revealed prominent myocardial and renal deposits of lambda light-chains which were Congo Red negative, and had a non-fibrillar ultrastructure. Non-amyloidotic light-chain deposition is uncommon, and a rare cause of cardiac disease. Previous work regarding possible pathogenetic mechanisms, clinical and laboratory features and treatment is reviewed. Images Figure 1 Figure 2 Figure 3 PMID:8415352

  13. Plasmonic transmission lines: from micro to nano scale with lambda/4 impedance matching.

    PubMed

    Ginzburg, Pavel; Orenstein, Meir

    2007-05-28

    The downscaling of conventional RF transmission lines methodologies to subwavelength plasmonic circuits is discussed and demonstrated for a lambda/4 transformer impedance matching. The nano-size transformer, matching between 0.5mum and 50nm wide plasmonic transmission lines, enhances the coupling efficiency by more than 285% compared to the direct ("end fire") coupling - i.e. harvesting more than 86% of total incident power. The influence of the transverse resonances induced by the metal claddings of the input transmission line on the light harvesting is discussed as well.

  14. Simultaneous presentation of kappa-restricted chronic lymphocytic leukemia and lambda light chain AL amyloidosis.

    PubMed

    von Keudell, Gottfried; Sanchorawala, Vaishali; O'Hara, Carl; C Seldin, David; Sloan, J Mark

    2014-06-01

    We report on a 58-year-old man who presented with simultaneous kappa-restricted chronic lymphocytic leukemia (CLL) and a lambda-restricted plasma cell dyscrasia causing AL amyloidosis involving the kidney and GI tract. While monoclonal immunoglobulins occasionally produced by CLL has previously been implicated in AL amyloidosis, this is the first case of AL amyloidosis resulting from a distinct plasma cell dyscrasia that is not clonally related to the concurrent CLL. Appropriate treatment depended on detailed pathologic diagnosis of both disease processes.

  15. K{Lambda}(1405) configuration of the KK-barN system

    SciTech Connect

    Martinez Torres, A.; Jido, D.

    2010-09-15

    We study the K{Lambda}(1405) configuration of the KK-barN system by considering K{pi}{Sigma} as a coupled channel. We solve the Faddeev equations for these systems and find confirmation of the existence of a new N{sup *} resonance around 1920 MeV, with J{sup {pi}=}1/2{sup +} predicted in a single-channel potential model and also found in a Faddeev calculation as an a{sub 0}(980)N state, with the a{sub 0}(980) generated in the KK-bar, {pi}{eta} interaction.

  16. Refractive index measured by laser beam displacement at {lambda}=1064 nm for solvents and deuterated solvents

    SciTech Connect

    Shelton, David P.

    2011-07-20

    The refractive index of a liquid is determined with 0.0003 accuracy from measurements of laser beam displacement by a liquid-filled standard 10 mm spectrophotometer cell. The apparatus and methods are described and the results of measurements at {lambda}=1064 nm and T=25.0 deg. C for 30 solvents and deuterated solvents are presented. Several sources of potential systematic errors as large as 0.003 are identified, the most important being the curvature of the liquid cell windows. The measurements are analyzed accounting for the significant imperfections of the apparatus.

  17. Electromagnetic Productions of K{lambda} and K{sigma} on the Nucleons

    SciTech Connect

    Mart, T.

    2008-10-13

    We review the progress and problems in the electromagnetic production of K{lambda} on the nucleon. The problem of the data discrepancy in this channel as well as the corresponding physics consequence are highlighted. We also discuss the effect of the new beam-recoil polarization data C{sub x} and C{sub z} on our analysis. For this purpose we use the isobar model Kaon-Maid and a recent multipoles model that can describe recent experimental data. We also present a new multipoles model for the K{sigma} channels to complete our analysis.

  18. Prediction of Narrow N* and {Lambda}* Resonances with Hidden Charm above 4 GeV

    SciTech Connect

    Wu Jiajun; Molina, R.; Oset, E.; Zou, B. S.

    2010-12-03

    The interaction between various charmed mesons and charmed baryons is studied within the framework of the coupled-channel unitary approach with the local hidden gauge formalism. Several meson-baryon dynamically generated narrow N{sup *} and {Lambda}{sup *} resonances with hidden charm are predicted with mass above 4 GeV and width smaller than 100 MeV. The predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks and can be looked for in the forthcoming PANDA/FAIR experiments.

  19. Additional atmospheric opacity measurements at lambda = 1.1 mm from Mauna Kea Observatory, Hawaii

    NASA Technical Reports Server (NTRS)

    Parrish, A.; De Zafra, R. L.; Barrett, J. W.; Solomon, P.; Connor, B.

    1987-01-01

    Atmospheric opacity values in the zenith direction are given for a wavelength of 1.1 mm (278 GHz) at the summit of Mauna Kea in the Hawaiian Islands. A total of 75 days is covered during the period 1983-1986. Observations were made on a quasi-continuous basis, with opacity measured every 20 minutes around the clock for significant periods of time. A conversion from opacity at lambda = 1.1 mm to the equivalent precipitable water vapor column is given from the measurements of Zammit and Ade (1981), from which opacities at other wavelengths may be derived.

  20. The global lambda visualization facility: An international ultra-high-definition wide-area visualization collaboratory

    USGS Publications Warehouse

    Leigh, J.; Renambot, L.; Johnson, Aaron H.; Jeong, B.; Jagodic, R.; Schwarz, N.; Svistula, D.; Singh, R.; Aguilera, J.; Wang, X.; Vishwanath, V.; Lopez, B.; Sandin, D.; Peterka, T.; Girado, J.; Kooima, R.; Ge, J.; Long, L.; Verlo, A.; DeFanti, T.A.; Brown, M.; Cox, D.; Patterson, R.; Dorn, P.; Wefel, P.; Levy, S.; Talandis, J.; Reitzer, J.; Prudhomme, T.; Coffin, T.; Davis, B.; Wielinga, P.; Stolk, B.; Bum, Koo G.; Kim, J.; Han, S.; Corrie, B.; Zimmerman, T.; Boulanger, P.; Garcia, M.

    2006-01-01

    The research outlined in this paper marks an initial global cooperative effort between visualization and collaboration researchers to build a persistent virtual visualization facility linked by ultra-high-speed optical networks. The goal is to enable the comprehensive and synergistic research and development of the necessary hardware, software and interaction techniques to realize the next generation of end-user tools for scientists to collaborate on the global Lambda Grid. This paper outlines some of the visualization research projects that were demonstrated at the iGrid 2005 workshop in San Diego, California.

  1. PWA prospects for K+Lambda and K+Sigma^0 photoproduction

    SciTech Connect

    Biplab Dey, Michael E. McCracken, Curtis A. Meyer

    2012-04-01

    We present a status update on the CMU group PWA efforts in the strangeness (K{sup +}{Lambda}/K{sup +}{Sigma}{sup 0}) sector. The bulk of the currently available data comes from recently published CLAS g11a results, with extensive polarization data expected soon from the CLAS g8 and g9 set of experiments. We give a brief description of issues pertaining to different sign conventions for the polarization observables in the literature, and normalization discrepancies between the CLAS-g11a results and older high energy data from SLAC/CEA/DESY that used an untagged photon beam.

  2. Detecting non-Abelian geometric phases with three-level {Lambda} systems

    SciTech Connect

    Du Yanxiong; Xue Zhengyuan; Zhang Xinding; Yan Hui

    2011-09-15

    We show that a non-Abelian gauge potential in two nearly degenerated dressed states may be induced by two laser beams interacting with a three-level {Lambda} atomic system. We demonstrate that the populations of the atomic states at the end of a composed path formed by two closed loops are dependent on the order of those two loops, showing an unambiguous signature of the non-Abelian geometric phase. Through numerical calculations, we show that the non-Abelian feature of the geometric phases can be tested under realistic conditions.

  3. B, Lambda{sub b} and charm results from the Tevatron

    SciTech Connect

    F. Azfar

    2003-09-18

    Recent results on B{sub d}, B{sub u}{sup {+-}}, B{sub s}, {Lambda}{sub b} and Charm hadrons are reported from {approx} 75 pb{sup -1} and {approx} 40 pb{sup -1} of data accumulated at the upgraded CDF and D0 experiments at the Fermilab Tevatron {bar p}-p collider, during Run-II. These include lifetime and mass measurements of B and Charm hadrons, searches for rare decays in charm and B hadrons and CP-violation in Charm decays. Results relevant to CP-violation in B-decays are also reported.

  4. Cosmological study with galaxy clusters detected by the Sunyaev-Zel'dovich effect

    NASA Astrophysics Data System (ADS)

    Mak, Suet-Ying

    In this work, we present various studies to forecast the power of the galaxy clusters detected by the Sunyaev-Zel'dovich (SZ) effect in constraining cosmological models. The SZ effect is regarded as one of the new and promising technique to identify and study cluster physics. With the latest data being released in recent years from the SZ telescopes, it is essential to explore their potentials in providing cosmological information and investigate their relative strengths with respect to galaxy cluster data from X-ray and optical, as well as other cosmological probes such as Cosmic Microwave Background (CMB). One of the topics regard resolving the debate on the existence of an anomalous large scale bulk flow as measured from the kinetic SZ signal of galaxy clusters in the WMAP CMB data. We predict that if such measurement is done with the latest CMB data from the Planck satellite, the sensitivity will be improved by a factor of >5 and thus be able to provide an independent view of its existence. As it turns out, the Planck data, when using the technique developed in this work, find that the observed bulk flow amplitude is consistent with those expected from the LambdaCDM, which is in clear contradiction to the previous claim of a significant bulk flow detection in the WMAP data. We also forecast on the capability of the ongoing and future cluster surveys identified through thermal SZ (tSZ) in constraining three extended models to the LambdaCDM model: modified gravity f( R) model, primordial non-Gaussianity of density perturbation, and the presence of massive neutrinos. We do so by employing their effects on the cluster number count and power spectrum and using Fisher Matrix analysis to estimate the errors on the model parameters. We find that SZ cluster surveys can provide vital complementary information to those expected from non-cluster probes. Our results therefore give the confidence for pursuing these extended cosmological models with SZ clusters.

  5. PREFACE: Nuclear Cluster Conference; Cluster'07

    NASA Astrophysics Data System (ADS)

    Freer, Martin

    2008-05-01

    The Cluster Conference is a long-running conference series dating back to the 1960's, the first being initiated by Wildermuth in Bochum, Germany, in 1969. The most recent meeting was held in Nara, Japan, in 2003, and in 2007 the 9th Cluster Conference was held in Stratford-upon-Avon, UK. As the name suggests the town of Stratford lies upon the River Avon, and shortly before the conference, due to unprecedented rainfall in the area (approximately 10 cm within half a day), lay in the River Avon! Stratford is the birthplace of the `Bard of Avon' William Shakespeare, and this formed an intriguing conference backdrop. The meeting was attended by some 90 delegates and the programme contained 65 70 oral presentations, and was opened by a historical perspective presented by Professor Brink (Oxford) and closed by Professor Horiuchi (RCNP) with an overview of the conference and future perspectives. In between, the conference covered aspects of clustering in exotic nuclei (both neutron and proton-rich), molecular structures in which valence neutrons are exchanged between cluster cores, condensates in nuclei, neutron-clusters, superheavy nuclei, clusters in nuclear astrophysical processes and exotic cluster decays such as 2p and ternary cluster decay. The field of nuclear clustering has become strongly influenced by the physics of radioactive beam facilities (reflected in the programme), and by the excitement that clustering may have an important impact on the structure of nuclei at the neutron drip-line. It was clear that since Nara the field had progressed substantially and that new themes had emerged and others had crystallized. Two particular topics resonated strongly condensates and nuclear molecules. These topics are thus likely to be central in the next cluster conference which will be held in 2011 in the Hungarian city of Debrechen. Martin Freer Participants and Cluster'07

  6. Investigations of potential bias in the estimation of lambda using Pradel's (1996) model for capture-recapture data

    USGS Publications Warehouse

    Hines, J.E.; Nichols, J.D.

    2002-01-01

    Pradel's (1996) temporal symmetry model permitting direct estimation and modelling of population growth rate, lambda sub i provides a potentially useful tool for the study of population dynamics using marked animals. Because of its recent publication date, the approach has not seen much use, and there have been virtually no investigations directed at robustness of the resulting estimators. Here we consider several potential sources of bias, all motivated by specific uses of this estimation approach. We consider sampling situations in which the study area expands with time and present an analytic expression for the bias in lambda hat sub i. We next consider trap response in capture probabilities and heterogeneous capture probabilities and compute large-sample and simulation-based approximations of resulting bias in lambda hat sub i. These approximations indicate that trap response is an especially important assumption violation that can produce substantial bias. Finally, we consider losses on capture and emphasize the importance of selecting the estimator for lambda sub i that is appropriate to the question being addressed. For studies based on only sighting and resighting data, Pradel's (1996) lambda hat prime sub i is the appropriate estimator.

  7. Construction and characterization of plasmid and lambda phage vector systems for study of transcriptional control in Escherichia coli.

    PubMed

    Hirano, M; Shigesada, K; Imai, M

    1987-01-01

    We constructed a family of lambda phage and plasmid vectors which facilitate cloning and quantitative analysis of transcriptional regulator in both single and multiple copies. Their expression system was modified from the ara-trp-lac fusion operon of plasmid pMC81 [Casadaban and Cohen, J. Mol. Biol. 138 (1980) 179-207], which is designed to assay both promoters and terminators with a single vehicle. To eliminate transcriptional and translational polar effects liable to occur in the original fusion operon upon insertion of a foreign nucleotide sequence, intracistronic Rho-dependent terminators, that are present within the trpB gene and distal to the cloning site were deleted, and DNA spacers containing stop codons were introduced immediately before and after the cloning site. In analysis of the cloned trp regulatory region, the lambda phage system faithfully reproduced the tight regulation by tryptophan characteristic to the natural trp operon on the E. coli chromosome, whereas the plasmid counterpart exhibited a substantially relaxed response. Comparative studies on the relative strengths of various promoters and terminators have further demonstrated that the lambda phage vector system permits accurate assays of exceptionally strong promoters like Ptrp and lambda pL without disturbing the bacterial growth, while being sensitive enough for detecting low-level transcription under the control of weak promoters or potent terminators. Cloning with the lambda phage vector can be greatly facilitated by transferring the target regulatory site precloned with the plasmid onto the phage genome through in vivo recombination.

  8. Spectral enhancement of proteins: biological incorporation and fluorescence characterization of 5-hydroxytryptophan in bacteriophage lambda cI repressor.

    PubMed Central

    Ross, J B; Senear, D F; Waxman, E; Kombo, B B; Rusinova, E; Huang, Y T; Laws, W R; Hasselbacher, C A

    1992-01-01

    We have used a tryptophan-requiring Escherichia coli auxotroph to replace the three tryptophan residues of lambda cI repressor with 5-hydroxy-L-tryptophan (5-OHTrp). By using a nonleaky promoter, we have achieved > 95% replacement of tryptophan in the repressor. We show that the absorbance and fluorescence properties of 5-OHTrp-lambda cI are clearly distinct from lambda cI repressor and that the fluorescence of 5-OHTrp-lambda cI repressor can be observed selectively in the presence of exogenous tryptophan. We also show that the 5-OHTrp-lambda cI repressor functional properties, as assessed by measurement of binding constants for self-association and for association to operator DNA, and structural properties, as assessed by fluorescence, are indistinguishable from the native repressor. Based on these results, we anticipate that the availability of spectrally enhanced proteins will significantly enhance the utility of both fluorescence and phosphorescence spectroscopies to study protein structure and function in complex interacting systems. PMID:1465434

  9. Spherically symmetric solutions, Newton's Law, and the infrared limit {lambda}{yields}1 in covariant Horava-Lifshitz gravity

    SciTech Connect

    Alexandre, Jean; Pasipoularides, Pavlos

    2011-10-15

    In this note we examine whether spherically symmetric solutions in covariant Horava-Lifshitz gravity can reproduce Newton's Law in the IR limit {lambda}{yields}1. We adopt the position that the auxiliary field A is independent of the space-time metric [J. Alexandre and P. Pasipoularides, Phys. Rev. D 83, 084030 (2011).][J. Greenwald, V. H. Satheeshkumar, and A. Wang, J. Cosmol. Astropart. Phys. 12 (2010) 007.], and we assume, as in [A. M. da Silva, Classical Quantum Gravity 28, 055011 (2011).], that {lambda} is a running coupling constant. We show that under these assumptions, spherically symmetric solutions fail to restore the standard Newtonian physics in the IR limit {lambda}{yields}1, unless {lambda} does not run, and has the fixed value {lambda}=1. Finally, we comment on the Horava and Melby-Thompson approach [P. Horava and C. M. Melby-Thompson, Phys. Rev. D 82, 064027 (2010).] in which A is assumed as a part of the space-time metric in the IR.

  10. The photodetected function of silicon photoelectronic lambda negative resistance transistor (PLBT)

    NASA Astrophysics Data System (ADS)

    Zhang, Shi-lin; Zhang, Bo; Guo, Wei-lian; Mao, Lu-hong; Zhang, Pei-ning

    2005-01-01

    In this paper, the photo-detected and controlled functions based on silicon photo-electronic Lambda transistor (PLBT) are reported. PLBT is composed of a npn vertical bipolar transistor as main device and a enhancement-mode MOSFET transistor as feedback device which connected in parallel across the base and collector terminals of bipolar transistor. Photo-electronic-lambda bipolar transistor (PLBT) is one important member of Si-photo electronic negative resistance devices. It has wide applications in photo-electronic coupler, light detector, light sensor and other photo-electronic circuit modules, which is significant for the further study of photo-electronic devices and circuits. When the Si-photo-electronic negative transistor device works as a load, it has two stable output states (bistability characteristics) with the change of the input light signals. Using the photo-bistable and self-locking characteristics of the PLBT, a photo-controlled Bistable Logic Circuit Element has been set up successfully. Through detail studying and analyzing to the operation feature and load feature of the photo-controlled bistable circuit, the nonlinear characteristic of the circuit is demonstrated. Furthermore the applications of this circuit element have been studied and verified.

  11. An analytical ultracentrifugation based study on the conformation of lambda carrageenan in aqueous solution.

    PubMed

    Almutairi, Fahad M; Adams, Gary G; Kök, Mehmet S; Lawson, Christopher J; Gahler, Roland; Wood, Simon; Foster, Timothy J; Rowe, Arthur J; Harding, Stephen E

    2013-08-14

    The conformation and heterogeneity of lambda-carrageenan, a sulphonated galactan from red seaweed, solubilised in aqueous solvent with the assistance of microwave irradiation, has been assessed by a combination of analytical ultracentrifugation, size-exclusion chromatography, light scattering and capillary viscometry. Preparations appeared generally unimodal on the basis of sedimentation coefficient distributions from sedimentation velocity although at the highest concentrations a shoulder appears with a sedimentation coefficient approximately 1.1 times greater than that of the main component. Even under conditions commensurate with charge suppression simple linear regression was insufficient to represent non-ideal concentration dependence and the extraction of the Grálen concentration dependence parameter ks. A more general fitting algorithm was therefore employed. Mark-Houwink-Kuhn-Sakurada analysis of the change in intrinsic viscosity [η] with molecular weight, together with the Wales-van Holde ratio (combination of ks with [η]) point to an extended flexible conformation for lambda-carrageenan in the (weight average) molecular weight range Mw=340,000-870,000g/mol. The origin of the larger sedimentation coefficient component appearing at the higher concentrations is considered.

  12. Monoclonal immunoglobulin M lambda coagulation inhibitor with phospholipid specificity. Mechanism of a lupus anticoagulant.

    PubMed Central

    Thiagarajan, P; Shapiro, S S; De Marco, L

    1980-01-01

    Prolongation of all phospholipid-dependent coagulation tests was found in a patient with macroglobulinemia, despite absence of bleeding manifestations. The purified monoclonal IgM lambda protein and its Fabmu tryptic fragment induced similar changes in normal plasma. Patient IgM and Fabmu completely inhibited Ca++-dependent binding of radiolabeled prothrombin and Factor X to mixed phospholipid micelles. The patient's IgM lambda paraprotein reacted with phosphatidylserine and, to a lesser extent, with phosphatidylinositol and phosphatidic acid, but not with phosphatidylcholine or phosphatidylethanolamine. Prior incubation of phospholipid with patient Fabmu blocked the positive reactions. Substitution of washed platelets for phospholipid led to normalization of patient coagulation tests and corrected all abnormalities produced in normal plasma by patient IgM. Furthermore, binding of 125I-Factor Xa to thrombin-treated platelets was entirely normal in the presence of patient IgM. These studies support the concept that platelets, rather than phospholipid micelles, are the primary locus of prothrombin and Factor X activation in normal hemostasis. Images PMID:6772673

  13. Solar cycle dependence of the sun's radius at lambda = 525.0 nm

    NASA Technical Reports Server (NTRS)

    Ulrich, Roger K.; Bertello, L.

    1995-01-01

    The Mount Wilson (California) synoptic program of solar magnetic observations scans the solar disk between 1 and 20 times per day. As part of this program, the radius is determined as an average distance between the image center and the point where the intensity in the FeI line at lambda = 525.0 nm drops to 25 percent of its value at the disk's center. The data base of information was analyzed and corrected for effects such as scattered light and atmospheric reflection. The solar variability and the measurement techniques are described. The observation data sets, the corrections made to the data, and the observed variations, are discussed. It is stated that similar spectral lines at lambda = 525.0 nm, which are common in the solar spectrum, probably exhibit similar radius changes. All portions of the sun are weighted equally so that it is concluded that, within spectral lines, the radiating area of the sun is increased at the solar maximum.

  14. Reliability analysis of repairable systems using Petri nets and vague Lambda-Tau methodology.

    PubMed

    Garg, Harish

    2013-01-01

    The main objective of the paper is to developed a methodology, named as vague Lambda-Tau, for reliability analysis of repairable systems. Petri net tool is applied to represent the asynchronous and concurrent processing of the system instead of fault tree analysis. To enhance the relevance of the reliability study, vague set theory is used for representing the failure rate and repair times instead of classical(crisp) or fuzzy set theory because vague sets are characterized by a truth membership function and false membership functions (non-membership functions) so that sum of both values is less than 1. The proposed methodology involves qualitative modeling using PN and quantitative analysis using Lambda-Tau method of solution with the basic events represented by intuitionistic fuzzy numbers of triangular membership functions. Sensitivity analysis has also been performed and the effects on system MTBF are addressed. The methodology improves the shortcomings of the existing probabilistic approaches and gives a better understanding of the system behavior through its graphical representation. The washing unit of a paper mill situated in a northern part of India, producing approximately 200 ton of paper per day, has been considered to demonstrate the proposed approach. The results may be helpful for the plant personnel for analyzing the systems' behavior and to improve their performance by adopting suitable maintenance strategies.

  15. A CI-Independent Form of Replicative Inhibition: Turn Off of Early Replication of Bacteriophage Lambda

    PubMed Central

    Hayes, Sidney; Horbay, Monique A.; Hayes, Connie

    2012-01-01

    Several earlier studies have described an unusual exclusion phenotype exhibited by cells with plasmids carrying a portion of the replication region of phage lambda. Cells exhibiting this inhibition phenotype (IP) prevent the plating of homo-immune and hybrid hetero-immune lambdoid phages. We have attempted to define aspects of IP, and show that it is directed to repλ phages. IP was observed in cells with plasmids containing a λ DNA fragment including oop, encoding a short OOP micro RNA, and part of the lambda origin of replication, oriλ, defined by iteron sequences ITN1-4 and an adjacent high AT-rich sequence. Transcription of the intact oop sequence from its promoter, pO is required for IP, as are iterons ITN3–4, but not the high AT-rich portion of oriλ. The results suggest that IP silencing is directed to theta mode replication initiation from an infecting repλ genome, or an induced repλ prophage. Phage mutations suppressing IP, i.e., Sip, map within, or adjacent to cro or in O, or both. Our results for plasmid based IP suggest the hypothesis that there is a natural mechanism for silencing early theta-mode replication initiation, i.e. the buildup of λ genomes with oop+ oriλ+ sequence. PMID:22590552

  16. HEATING OF THE MAGNETIC CHROMOSPHERE: OBSERVATIONAL CONSTRAINTS FROM Ca II {lambda}8542 SPECTRA

    SciTech Connect

    De la Cruz Rodriguez, J.; De Pontieu, B.; Carlsson, M.; Rouppe van der Voort, L. H. M.

    2013-02-10

    The heating of the Sun's chromosphere remains poorly understood. While progress has been made on understanding what drives the quiet-Sun internetwork chromosphere, chromospheric heating in strong magnetic field regions continues to present a difficult challenge, mostly because of a lack of observational constraints. We use high-resolution spectropolarimetric data from the Swedish 1 m Solar Telescope to identify the location and spatio-temporal properties of heating in the magnetic chromosphere. In particular, we report the existence of raised-core spectral line profiles in the Ca II {lambda}8542 line. These profiles are characterized by the absence of an absorption line core, showing a quasi-flat profile between {lambda} Almost-Equal-To {+-}0.5 A, and are abundant close to magnetic bright points and plage. Comparison with three-dimensional MHD simulations indicates that such profiles occur when the line of sight goes through an ''elevated temperature canopy'' associated with the expansion with height of the magnetic field of flux concentrations. This temperature canopy in the simulations is caused by ohmic dissipation where there are strong magnetic field gradients. The raised-core profiles are thus indicators of locations of increased chromospheric heating. We characterize the location and temporal and spatial properties of such profiles in our observations, thus providing much stricter constraints on theoretical models of chromospheric heating mechanisms than before.

  17. Three-dimensional theory of quantum memories based on {Lambda}-type atomic ensembles

    SciTech Connect

    Zeuthen, Emil; Grodecka-Grad, Anna; Soerensen, Anders S.

    2011-10-15

    We develop a three-dimensional theory for quantum memories based on light storage in ensembles of {Lambda}-type atoms, where two long-lived atomic ground states are employed. We consider light storage in an ensemble of finite spatial extent and we show that within the paraxial approximation the Fresnel number of the atomic ensemble and the optical depth are the only important physical parameters determining the quality of the quantum memory. We analyze the influence of these parameters on the storage of light followed by either forward or backward read-out from the quantum memory. We show that for small Fresnel numbers the forward memory provides higher efficiencies, whereas for large Fresnel numbers the backward memory is advantageous. The optimal light modes to store in the memory are presented together with the corresponding spin waves and outcoming light modes. We show that for high optical depths such {Lambda}-type atomic ensembles allow for highly efficient backward and forward memories even for small Fresnel numbers F(greater-or-similar sign)0.1.

  18. Tuning the phase sensitivity of a double-lambda system with a static magnetic field.

    PubMed

    Xu, Xiwei; Shen, Shuo; Xiao, Yanhong

    2013-05-20

    We study the effect of a DC magnetic field on the phase sensitivity of a double-lambda system coupled by two laser fields, a probe and a pump. It is demonstrated that the gain and the refractive index of the probe can be controlled by either the magnetic field or the relative phase between the two laser fields. More interestingly, when the system reduces to a single-lambda system, turning on the magnetic field transforms the system from a phase-insensitive process to a phase-sensitive one. In the pulsed-probe regime, we observed switching between slow and fast light when the magnetic field or the relative phase was adjusted. Experiments using a coated 87Rb vapor cell produced results in good agreement with our numerical simulation. This work provides a novel and simple means to manipulate phase sensitive electromagnetically-induced-transparency or four-wave mixing, and could be useful for applications in quantum optics, nonlinear optics and magnetometery based on such systems.

  19. The 24 GHz measurements of 2.2 lambda conical horn antennas illuminating a conducting sheet

    NASA Technical Reports Server (NTRS)

    Cross, A. E.; Marshall, R. E.; Hearn, C. P.; Neece, R. T.

    1993-01-01

    Monostatic reflection-coefficient magnitude, absolute value of Gamma, measurements occurring between a radiating horn and a metal reflecting plate are presented for a family of three 2.2 lambda diameter conical horn antennas. The three horns have different aperture phase deviations: 6 deg, 22.5 deg, and 125 deg. Measurements of the magnitude of absolute value of Gamma as a function of horn-plate separation (d) extend from an effective antenna aperture short (d = O) to beyond the far-field boundary (d = 2D(sup 2)/lambda, where D is the antenna diameter). Measurement data are presented with various physical environments for each of the horns. Measured scalar data are compared with theoretical data from two models, a numerical model for a circular waveguide aperture in a ground plane and a scalar diffraction theory model. This work was conducted in support of the development effort for a spaceborne multifrequency microwave reflectometer designed to accurately determine the distance from a space vehicle's surface to a reflecting plasma boundary. The metal reflecting plate was used to simulate the RF reflectivity of a critically dense plasma. The resulting configuration, a ground plane mounted aperture facing a reflecting plane in close proximity, produces a strong interaction between the ground plane and the reflecting plate, especially at integral half-wavelength separations. The transition coefficient is characterized by large amplitude variations.

  20. Stability of CII is a key element in the cold stress response of bacteriophage lambda infection.

    PubMed Central

    Obuchowski, M; Shotland, Y; Koby, S; Giladi, H; Gabig, M; Wegrzyn, G; Oppenheim, A B

    1997-01-01

    Bacteria are known to adapt to environmental changes such as temperature fluctuations. It was found that temperature affects the lysis-lysogeny decision of lambda such that at body temperature (37 degrees C) the phage can select between the lytic and lysogenic pathways, while at ambient temperature (20 degrees C) the lytic pathway is blocked. This temperature-dependent discriminatory developmental pathway is governed mainly by the phage CII activity as a transcriptional activator. Mutations in cII or point mutations at the pRE promoter lead to an over-1,000-fold increase in mature-phage production at low temperature while mutations in cI cause a smaller increase in phage production. Interference with CII activity can restore lytic growth at low temperature. We found that at low temperature the stability of CII in vivo is greatly increased. It was also found that phage DNA replication is blocked at 20 degrees C but can be restored by supplying O and P in trans. It is proposed that CII hampers transcription of the rightward pR promoter, thus reducing the levels of the lambda O and P proteins, which are necessary for phage DNA replication. Our results implicate CII itself or host proteins affecting CII stability as a "molecular thermometer". PMID:9324241

  1. Stability of CII is a key element in the cold stress response of bacteriophage lambda infection.

    PubMed

    Obuchowski, M; Shotland, Y; Koby, S; Giladi, H; Gabig, M; Wegrzyn, G; Oppenheim, A B

    1997-10-01

    Bacteria are known to adapt to environmental changes such as temperature fluctuations. It was found that temperature affects the lysis-lysogeny decision of lambda such that at body temperature (37 degrees C) the phage can select between the lytic and lysogenic pathways, while at ambient temperature (20 degrees C) the lytic pathway is blocked. This temperature-dependent discriminatory developmental pathway is governed mainly by the phage CII activity as a transcriptional activator. Mutations in cII or point mutations at the pRE promoter lead to an over-1,000-fold increase in mature-phage production at low temperature while mutations in cI cause a smaller increase in phage production. Interference with CII activity can restore lytic growth at low temperature. We found that at low temperature the stability of CII in vivo is greatly increased. It was also found that phage DNA replication is blocked at 20 degrees C but can be restored by supplying O and P in trans. It is proposed that CII hampers transcription of the rightward pR promoter, thus reducing the levels of the lambda O and P proteins, which are necessary for phage DNA replication. Our results implicate CII itself or host proteins affecting CII stability as a "molecular thermometer".

  2. Heat capacity and thermal relaxation of bulk helium very near the lambda point

    NASA Technical Reports Server (NTRS)

    Lipa, John A.; Swanson, D. R.; Nissen, J. A.; Chui, T. C. P.

    1994-01-01

    In October 1992 a low temperature experiment was flown on the Space Shuttle in low Earth orbit. The objective of the mission was to measure the heat capacity and thermal conductivity of helium very close to the lambda point with the smearing effect of gravity removed. We report preliminary results from the experiment, and compare them with related measurements performed on the ground. The sample was s sphere of helium 3.5 cm in diameter contained within a copper calorimeter of vey high thermal conductivity. The calorimeter was attached to a pair of high resolution paramagnetic salt thermometers with noise levels in the 10(exp -10) K range and suspended from a high stability thermal isolation system. During the mission we found that the resolution of the thermometers was degraded somewhat due to the impact of charged particles. This effect limited the useful resolution of the measurements to about two nanokelvins from the lambda point. The results reported here are limited to about ten nanokelvins from the transition.

  3. Cell-type preference of immunoglobulin kappa and lambda gene promoters.

    PubMed Central

    Picard, D; Schaffner, W

    1985-01-01

    Immunoglobulin gene constant regions are known to be associated with strictly tissue-specific enhancer elements. Until recently the promoter of the variable region, which becomes linked to the constant region by somatic rearrangement, could have been viewed as a passive recipient of the enhancer stimulus. Here we show that the promoters of the immunoglobulin kappa and lambda light chain genes are approximately 20-30 times more active in lymphoid cells than in non-lymphoid cells. To avoid the problem of differential mRNA stability upon transfection of immunoglobulin genes into non-lymphoid cells we have constructed chimeric genes. All kappa mRNA sequences were progressively deleted to fuse the kappa gene promoter to a globin gene coding body. A similar chimeric gene was constructed with the promoter of the lambda gene. The cell-type preference of the promoter may be exploited during B-lymphocyte differentiation to regulate the immunoglobulin gene promoter independently from the enhancer. Images Fig. 2. Fig. 4. Fig. 5. Fig. 6. PMID:2998757

  4. Processing of Escherichia coli 16S rRNA with bacteriophage lambda leader sequences.

    PubMed Central

    Krych, M; Sirdeshmukh, R; Gourse, R; Schlessinger, D

    1987-01-01

    To test whether any specific 5' precursor sequences are required for the processing of pre-16S rRNA, constructs were studied in which large parts of the 5' leader sequence were replaced by the coliphage lambda pL promoter and adjacent sequences. Unexpectedly, few full-length transcripts of the rRNA were detected after the pL promoter was induced, implying that either transcription was poor or most of the rRNA chains with lambda leader sequences were unstable. Nevertheless, sufficient transcription occurred to permit the detection of processing by S1 nuclease analysis. RNA transcripts in which 2/3 of the normal rRNA leader was deleted (from the promoter up to the normal RNase III cleavage site) were processed to form the normal 5' terminus. Thus, most of the double-stranded stem that forms from sequences bracketing wild-type 16S pre-rRNA is apparently not required for proper processing; the expression of such modified transcripts, however, must be increased before the efficiency of processing of the 16S rRNA formed can be assessed. Images PMID:2445728

  5. NO Detection by Pulsed Polarization of Lambda Probes–Influence of the Reference Atmosphere

    PubMed Central

    Fischer, Sabine; Schönauer-Kamin, Daniela; Pohle, Roland; Fleischer, Maximilian; Moos, Ralf

    2013-01-01

    The pulsed polarization measurement technique using conventional thimble type lambda probes is suitable for low ppm NOx detection in exhaust gas applications. To evaluate the underlying sensor mechanism, the unknown influence of the reference atmosphere on the NO sensing behavior is investigated in this study. Besides answering questions with respect to the underlying principle, this investigation can resolve the main question of whether a simplified sensor element without reference may be also suitable for NO sensing using the pulsed polarization measurement technique. With an adequate sensor setup, the reference atmosphere of the thimble type lambda probe is changed completely after a certain diffusion time. Thus, the sensor response regarding NO is compared with and without different gas atmospheres on both electrodes. It is shown that there is still a very good NO sensitivity even without reference air, although the NO response is reduced due to non-existing overlying mixed potential type voltage, which is otherwise caused by different atmospheres on both electrodes. Considering these results, we see an opportunity to simplify the standard NOx sensor design by omitting the reference electrode.

  6. Observation of Mollow Triplets with Tunable Interactions in Double Lambda Systems of Individual Hole Spins

    NASA Astrophysics Data System (ADS)

    Lagoudakis, K. G.; Fischer, K. A.; Sarmiento, T.; McMahon, P. L.; Radulaski, M.; Zhang, J. L.; Kelaita, Y.; Dory, C.; Müller, K.; Vučković, J.

    2017-01-01

    Although individual spins in quantum dots have been studied extensively as qubits, their investigation under strong resonant driving in the scope of accessing Mollow physics is still an open question. Here, we have grown high quality positively charged quantum dots embedded in a planar microcavity that enable enhanced light-matter interactions. Under a strong magnetic field in the Voigt configuration, individual positively charged quantum dots provide a double lambda level structure. Using a combination of above-band and resonant excitation, we observe the formation of Mollow triplets on all optical transitions. We find that when the strong resonant drive power is used to tune the Mollow-triplet lines through each other, we observe anticrossings. We also demonstrate that the interaction that gives rise to the anticrossings can be controlled in strength by tuning the polarization of the resonant laser drive. Quantum-optical modeling of our system fully captures the experimentally observed spectra and provides insight on the complicated level structure that results from the strong driving of the double lambda system.

  7. Measurements of the branching fractions for B{sub (s)}{yields}D{sub (s)}{pi}{pi}{pi} and {Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{pi}{pi}

    SciTech Connect

    Aaij, R.; Bauer, Th.; Beuzekom, M. van; Carvalho Akiba, K.; Coco, V.; van Eijk, D.; Farinelli, C.; Heijne, V.; Hulsbergen, W.; Jans, E.; Jansen, F.; Koppenburg, P.; Kozlinskiy, A.; van Leerdam, J.; Merk, M.; Mous, I.; Oggero, S.; Pellegrino, A.; du Pree, T.; Storaci, B.

    2011-11-01

    Branching fractions of the decays H{sub b}{yields}H{sub c}{pi}{sup -}{pi}{sup +}{pi}{sup -} relative to H{sub b}{yields}H{sub c}{pi}{sup -} are presented, where H{sub b} (H{sub c}) represents B{sup 0} (D{sup +}), B{sup -} (D{sup 0}), B{sub s}{sup 0} (D{sub s}{sup +}), and {Lambda}{sub b}{sup 0} ({Lambda}{sub c}{sup +}). The measurements are performed with the LHCb detector using 35 pb{sup -1} of data collected at {radical}(s)=7 TeV. The ratios of branching fractions are measured to be [B(B{sup 0}{yields}D{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})]/[B(B{sup 0}{yields}D{sup +}{pi}{sup -})]=2.38{+-}0.11{+-}0.21, [B(B{sup -}{yields}D{sup 0}{pi}{sup -}{pi}{sup +}{pi}{sup -})]/[B(B{sup -}{yields}D{sup 0}{pi}{sup -})]= 1.27{+-}0.06{+-}0.11, [B(B{sub s}{sup 0}{yields}D{sub s}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})]/[B(B{sub s}{sup 0}{yields}D{sub s}{sup +}{pi}{sup -})]=2.01{+-}0.37{+-}0.20, [B({Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{sup -} {pi}{sup +}{pi}{sup -})]/[B({Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{sup -})]=1.43{+-}0.16{+-}0.13 We also report measurements of partial decay rates of these decays to excited charm hadrons. These results are of comparable or higher precision than existing measurements.

  8. Angular Distributions for 3,4 Lambda H Bound States in the 3,4 He(e,e'K+) reaction

    SciTech Connect

    Dohrmann, Frank; Ahmidouch, Abdellah; Armstrong, Christopher; Arrington, John; Asaturyan, Razmik; Avery, Steven; Bailey, Kevin; Hu, Bitao; Breuer, Herbert; Brown, Daniel; Carlini, Roger; Cha, Jinseok; Chant, Nicholas; Christy, Michael; Cochran, Anthony; Cole, Leon; Crowder, J.; Danagoulian, Samuel; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Fujii, Yu; Gan, Liping; Garrow, Kenneth; Gueye, Paul; Hafidi, Kawtar; Hinton, Wendy; Juengst, Henry; Keppel, Cynthia; Liang, Yongguang; Liu, Jinghua; Lung, Allison; Mack, David; Markowitz, Pete; Mitchell, Joseph; Miyoshi, Toshinobu; Mkrtchyan, Hamlet; Mtingwa, Sekazi; Mueller, Robert; Niculescu, Gabriel; Niculescu, Maria-Ioana; Potterveld, David; Raue, Brian; Reimer, Paul; Reinhold, Joerg; Roche, Julie; Sarsour, Murad; Sato, Yoshinori; Segel, Ralph; Semenov, Andrei; Stepanyan, Samuel; Tadevosyan, Vardan; Tajima, Shigeyuki; Tang, Liguang; Uzzle, Alicia; Wood, Stephen; Yamaguchi, Hiroshi; Yan, Chen; Yuan, Lulin; Zeidman, Benjamin; Zeier, Markus; Zihlmann, Benedikt

    2004-12-01

    The 3Lambda H and 4Lambda H hypernuclear bound states have been observed for the first time in kaon electroproduction on 3,4He targets. The production cross sections have been determined at Q**2= 0.35 GeV**2 and W= 1.91 GeV. For either hypernucleus the nuclear form factor is determined by comparing the angular distribution of the 3,4He(e,e'K+)3,4Lambda H processes to the elementary cross section 1H(e,e'K+) Lambda on the free proton, measured during the same experiment.

  9. Cluster Physics with Merging Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Molnar, Sandor

    Collisions between galaxy clusters provide a unique opportunity to study matter in a parameter space which cannot be explored in our laboratories on Earth. In the standard ΛCDM model, where the total density is dominated by the cosmological constant (Λ) and the matter density by cold dark matter (CDM), structure formation is hierarchical, and clusters grow mostly by merging. Mergers of two massive clusters are the most energetic events in the universe after the Big Bang, hence they provide a unique laboratory to study cluster physics. The two main mass components in clusters behave differently during collisions: the dark matter is nearly collisionless, responding only to gravity, while the gas is subject to pressure forces and dissipation, and shocks and turbulence are developed during collisions. In the present contribution we review the different methods used to derive the physical properties of merging clusters. Different physical processes leave their signatures on different wavelengths, thus our review is based on a multifrequency analysis. In principle, the best way to analyze multifrequency observations of merging clusters is to model them using N-body/HYDRO numerical simulations. We discuss the results of such detailed analyses. New high spatial and spectral resolution ground and space based telescopes will come online in the near future. Motivated by these new opportunities, we briefly discuss methods which will be feasible in the near future in studying merging clusters.

  10. Search for Bbar to Lambda_c+ X l- nu Decays in Events with a Fully Reconstructed B Meson

    SciTech Connect

    Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Tanabe, T.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2012-04-19

    We present a search for semileptonic B decays to the charmed baryon {Lambda}{sub c}{sup +} based on 420 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. By fully reconstructing the recoiling B in a hadronic decay mode, we reduce non-B backgrounds and determine the flavor of the signal B. We statistically correct the flavor for the effect of the B{sup 0} mixing. We obtain a 90% confidence level upper limit of {Beta}({bar B} {yields} {Lambda}{sub c}{sup +} X{ell}{sup -} {bar {nu}}{sub {ell}})/{Beta}({bar B} {yields} {Lambda}{sub c}{sup +} X) < 3.5%.

  11. Phylogeny, genomic organization and expression of lambda and kappa immunoglobulin light chain genes in a reptile, Anolis carolinensis.

    PubMed

    Wu, Qian; Wei, Zhiguo; Yang, Zhi; Wang, Tao; Ren, Liming; Hu, Xiaoxiang; Meng, Qingyong; Guo, Ying; Zhu, Qinghong; Robert, Jacques; Hammarström, Lennart; Li, Ning; Zhao, Yaofeng

    2010-05-01

    The reptiles are the last major taxon of jawed vertebrates in which immunoglobulin light chain isotypes have not been well characterized. Using the recently released genome sequencing data, we show in this study that the reptile Anolis carolinensis expresses both lambda and kappa light chain genes. The genomic organization of both gene loci is structurally similar to their respective counterparts in mammals. The identified lambda locus contains three constant region genes each preceded by a joining gene segment, and a total of 37 variable gene segments. In contrast, the kappa locus contains only a single constant region gene, and two joining gene segments with a single family of 14 variable gene segments located upstream. Analysis of junctions of the recombined VJ transcripts reveals a paucity of N and P nucleotides in both expressed lambda and kappa sequences. These results help us to understand the generation of the immunoglobulin repertoire in reptiles and immunoglobulin evolution in vertebrates.

  12. Dissipation kinetics of alpha-cypermethrin and lambda-cyhalothrin residues in aboveground part of white mustard (Sinapis alba L.).

    PubMed

    Słowik-Borowiec, Magdalena

    2016-09-01

    Dissipation of simultaneously applied insecticides alpha-cypermethrin and lambda-cyhalothrin was studied in a minor crop, aboveground part of white mustard (Sinapis alba L.). A validated gas chromatographic method (GC-ECD/NPD) was used to determine insecticide residues. Analytical performances were very satisfactory, with expanded uncertainties not higher than 14% (coverage factor k = 2, confidence level 95%). Dissipation of alpha-cypermethrin and lambda-cyhalothrin in white mustard followed first-order kinetics (R(2) between 0.953 and 0.995), with half-lives of 3.1-4.6 and 2.9-3.7 days respectively. Based on the results of this two-year study and the relevant residue regulation, alpha-cypermethrin and lambda-cyhalothrin treatments can be considered safe for crop protection, feeding animals and the environment.

  13. Dynamically generated N* and {Lambda}* resonances in the hidden charm sector around 4.3 GeV

    SciTech Connect

    Wu Jiajun; Molina, R.; Oset, E.; Zou, B. S.

    2011-07-15

    The interactions of D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled-channel unitary approach with the local hidden gauge formalism. A series of meson-baryon dynamically generated relatively narrow N* and {Lambda}* resonances are predicted around 4.3 GeV in the hidden charm sector. We make estimates of production cross sections of these predicted resonances in p-barp collisions for the experiment of antiproton annihilation at Darmstadt (PANDA) at the forthcoming GSI Facility for Antiproton and Ion Research (FAIR) facility.

  14. Toward a bacterial genome technology: integration of the Escherichia coli prophage lambda genome into the Bacillus subtilis 168 chromosome.

    PubMed

    Itaya, M

    1995-07-22

    A novel approach to the cloning large DNAs in the Bacillus subtilis chromosome was examined. An Escherichia coli prophage lambda DNA (48.5 kb) was assembled in the chromosome of B. subtilis. The lambda DNA was first subcloned in four segments, having partially overlapping regions. Assembly of the complete prophage was achieved by successive transformation using three discrete DNA integration modes: overlap-elongation, Campbell-type integration, and gap-filling. In the B. subtilis chromosome, DNA was elongated, using contiguous DNA segments, via overlap-elongation. Jumping from one end of a contiguous DNA stretch to another segment was achieved by Campbell-type integration. The remaining gap was sealed by gap-filling. The incorporated lambda DNA thus assembled was stably replicated as part of the 4188 kb B. subtilis chromosome under non-selective conditions. The present method can be used to accommodate larger DNAs in the B. subtilis chromosome and possible applications of this technique are discussed.

  15. Gold-bismuth clusters.

    PubMed

    Martínez, Ana

    2014-08-07

    Metal clusters have interesting characteristics, such as the relationship between properties and size of the cluster. This is not always apparent, so theoretical studies can provide relevant information. In this report, optimized structures and electron donor-acceptor properties of AunBim clusters are reported (n + m = 2-7, 20). Density functional theory calculations were performed to obtain optimized structures. The ground states of gold clusters formed with up to seven atoms are planar. The presence of Bi modifies the structure, and the clusters become 3-D. Several optimized geometries have at least one Bi atom bonded to gold or bismuth atoms and form structures similar to NH3. This fragment is also present in clusters with 20 atoms, where the formation of Au3Bi stabilizes the structures. Bismuth clusters are better electron donors and worse electron acceptors than gold clusters. Mixed clusters fall in between these two extremes. The presence of Bi atoms in gold clusters modifies the electron donor-acceptor properties of the clusters, but there is no correlation between the number of Bi atoms present in the cluster and the capacity for donating electrons. The effect of planarity in Au19Bi clusters is the same as that in Au20 clusters. The properties of pure gold clusters are certainly interesting, but clusters formed by Bi and Au are more important because the introduction of different atoms modifies the geometry, the stability, and consequently the physical and chemical properties. Apparently, the presence of Bi may increase the reactivity of gold clusters, but further studies are necessary to corroborate this hypothesis.

  16. Nuclear Clusters in Astrophysics

    NASA Astrophysics Data System (ADS)

    Kubono, S.; Binh, Dam N.; Hayakawa, S.; Hashimoto, H.; Kahl, D.; Wakabayashi, Y.; Yamaguchi, H.; Teranishi, T.; Iwasa, N.; Komatsubara, T.; Kato, S.; Khiem, Le H.

    2010-03-01

    The role of nuclear clustering is discussed for nucleosynthesis in stellar evolution with Cluster Nucleosynthesis Diagram (CND) proposed before. Special emphasis is placed on α-induced stellar reactions together with molecular states for O and C burning.

  17. Matlab Cluster Ensemble Toolbox

    SciTech Connect

    Sapio, Vincent De; Kegelmeyer, Philip

    2009-04-27

    This is a Matlab toolbox for investigating the application of cluster ensembles to data classification, with the objective of improving the accuracy and/or speed of clustering. The toolbox divides the cluster ensemble problem into four areas, providing functionality for each. These include, (1) synthetic data generation, (2) clustering to generate individual data partitions and similarity matrices, (3) consensus function generation and final clustering to generate ensemble data partitioning, and (4) implementation of accuracy metrics. With regard to data generation, Gaussian data of arbitrary dimension can be generated. The kcenters algorithm can then be used to generate individual data partitions by either, (a) subsampling the data and clustering each subsample, or by (b) randomly initializing the algorithm and generating a clustering for each initialization. In either case an overall similarity matrix can be computed using a consensus function operating on the individual similarity matrices. A final clustering can be performed and performance metrics are provided for evaluation purposes.

  18. Dynamic Processes in Be Star Atmospheres.. 6; Simultaneous X-Ray, Ultraviolet, and Optical Variations in lambda Eridani

    NASA Technical Reports Server (NTRS)

    Smith, Myron A.; Murakami, T.; Ezuka, H.; Anandarao, B. G.; Chakraborty, A.; Corcoran, M. F.; Hirata, R.

    1995-01-01

    This report describes a joint X ray/ultraviolet/ground based study of the abnormal Be star lambda Eri which has previously shown evidence of X ray flaring from Rosat observations in 1991. The 1991 flare event caught the astronomical hot star community by surprise because x ray flares have not been observed from other single B-type stars, before or since. Both optical (H-alpha) and UV/Voyager observations provide evidence for transient heating events near the surface of lambda Eri.

  19. [Pathophysiology of cluster headache].

    PubMed

    Donnet, Anne

    2015-11-01

    The aetiology of cluster headache is partially unknown. Three areas are involved in the pathogenesis of cluster headache: the trigeminal nociceptive pathways, the autonomic system and the hypothalamus. The cluster headache attack involves activation of the trigeminal autonomic reflex. A dysfunction located in posterior hypothalamic gray matter is probably pivotal in the process. There is a probable association between smoke exposure, a possible genetic predisposition and the development of cluster headache.

  20. Spectroscopic studies and structure of 3-methoxy-2 -[(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde

    SciTech Connect

    Oezay, H.; Yildiz, M.; Uenver, H.; Durlu, T. N.

    2013-01-15

    The compound called 3-methoxy-2- [(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, {sup 1}H NMR, {sup 13}C NMR, {sup 31}P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) A, R{sub 1} = 0.0390 and wR{sub 2} = 0.1074 [I > 2{sigma}(I)], respectively.

  1. Clustering algorithm studies

    NASA Astrophysics Data System (ADS)

    Graf, Norman A.

    2001-07-01

    An object-oriented framework for undertaking clustering algorithm studies has been developed. We present here the definitions for the abstract Cells and Clusters as well as the interface for the algorithm. We intend to use this framework to investigate the interplay between various clustering algorithms and the resulting jet reconstruction efficiency and energy resolutions to assist in the design of the calorimeter detector.

  2. Homologous overexpression of a lipase from Burkholderia cepacia using the lambda Red recombinase system.

    PubMed

    Jia, Bin; Yang, Jiang-Ke; Liu, Wen-Shan; Li, Xu; Yan, Yun-Jun

    2010-04-01

    Red recombinase system of the lambda phage is widely used for recombination of short linear DNA fragments and genome. Using this system, we obtained T7 RNA polymerase (RNAP) substitution mutants in Burkholderia cepacia. To test the expression abilities of the T7 mutants, four different lipase expression vectors were transformed and the lipase activity of these recombinants was evaluated. Our results suggest that 500 nt homology between the unit and the genome is sufficient to generate mutations and this strategy enables the rapid establishment of mutant strains with efficiencies of 85%. After expression and purification, the highest purified lipase activity obtained was 3,990 U/l, nearly triple that of the wild-type organism.

  3. An Escherichia coli gene required for bacteriophage P2-lambda interference.

    PubMed Central

    Ghisotti, D; Zangrossi, S; Sironi, G

    1983-01-01

    The gene old of bacteriophage P2 is known to (i) cause interference with phage lambda growth; (ii) kill recB- mutants of Escherichia coli after P2 infection; and (iii) determine increased sensitivity of P2 lysogenic cells to X-ray irradiation. In all of these phenomena, inhibition of protein synthesis occurs. We have isolated bacterial mutants, named pin (P2 interference), able to suppress all of the above-mentioned phenomena caused by the old+ gene product and the concurrent protein synthesis inhibition. Pin mutations are recessive, map at 12 min on the E. coli map, and identify a new gene. Satellite bacteriophage P4 does not plate on pin-3 mutant strains and causes cell lethality and protein synthesis inhibition in such mutants. P4 mutants able to grow on pin-3 strains have been isolated. PMID:6355505

  4. Analysis of the velocity law in the wind of the Be star Lambda Pavonis

    NASA Technical Reports Server (NTRS)

    Chen, Haiqi; Ringuelet, Adela; Sahade, Jorge; Kondo, Yoji

    1989-01-01

    This paper reanalyzes the IUE spectra of Lambda Pavonis secured in 1982 (Sahade et al.). It is found that the profiles of the broad UV lines are either rotationally broadened or nonrotationally broadened and that the rotationally broadened profiles can be sorted out in two groups characterized by rotational velocity values of 170 km/s and of 210 km/s, respectively. From the analysis of the rotational and of the radial velocities it is possible to distinguish two regions in the extended atmosphere of the star, namely, a region which is rotating and a region which is expanding. In the rotating region, the radial velocities are about zero, and the rotational velocity increases from 170 km/s to 250 km/s. In the expanding region, the rotational energy dissipates, the wind is accelerated to a maximum of -155 km/s, and farther out it decelerates.

  5. Coherent manipulation of noise-protected superconducting artificial atoms in the Lambda scheme

    NASA Astrophysics Data System (ADS)

    Di Stefano, P. G.; Paladino, E.; Pope, T. J.; Falci, G.

    2016-05-01

    We propose a protocol for the manipulation of a three-level artificial atom in Lambda (Λ ) configuration. It allows faithful, selective and robust population transfer analogous to stimulated Raman adiabatic passage (Λ -STIRAP), in last-generation superconducting artificial atoms, where protection from noise implies the absence of a direct pump coupling. It combines the use of a two-photon pump pulse with suitable advanced control, operated by a slow modulation of the phase of the external fields, leveraging on the stability of semiclassical microwave drives. This protocol is a building block for manipulation of microwave photons in complex quantum architectures. Its demonstration would be a benchmark for the implementation of a class of multilevel advanced control procedures for quantum computation and microwave quantum photonics in systems based on artificial atoms.

  6. Line shape of a transition between two levels in a three-level {Lambda} configuration

    SciTech Connect

    Han, Hyok Sang; Jeong, Ji Eun; Cho, D.

    2011-09-15

    We report on our study of the line shape of a transition between two levels in a three-level {Lambda} configuration. By using Poisson statistics under the assumption that the atom stays in a two-level steady state before it is optically pumped to the reservoir state, we arrive at a simple analytic expression for the line shape of a three-level atom. This expression reveals a new type of saturation in the time domain, which is conceptually different from that of power-broadening in a two-level atom. It can also be used as a basis for more complicated situations of Doppler-broadened gaseous samples or pump-and-probe spectroscopy. We tested the theory experimentally in an ideal situation of slow pulsed {sup 85}Rb atoms and found excellent agreement. Application to measurements of a branching ratio or a Franck-Condon factor of a diatomic molecule is discussed.

  7. Properties of the Resonance Lambda(1520) as seen in the Forward Electroproduction at JLab Hall A

    SciTech Connect

    I.I. Strakovsky, Y. Qiang, Ya.I. Azimov, W.J. Briscoe, H. Gao, D.W. Higinbotham, V.V. Nelyubin

    2011-10-01

    High-resolution spectrometer measurements of the reaction H(e,e' K+)X at small Q2 are used to extract the mass and width of the Lambda(1520). We investigate dependence of the resonance parameters on different parametrizations of the background and the resonance peak itself. Our final values for the Breit-Wigner parameters are M=1520.4+-0.6(stat)+-1.5(syst) MeV and Gamma=18.6+-1.9(stat)+-1(syst) MeV. The width appears to be more sensitive to the assumptions than the mass. We also estimate, for the first time, the pole position for this resonance and find that both the pole mass and width seem to be smaller than their Breit-Wigner values.

  8. Study of Flow of Superfluid He-II Very Near Tau(sub lambda)

    NASA Technical Reports Server (NTRS)

    Mukharsky, Yury; Sukhatme, Kalyani; Pearson, David; Chui, Talso

    1999-01-01

    We report here, preliminary data from an experiment studying flow of superfluid helium through a slit orifice (of sub-micron width) very close to T(sub lambda). Critical supercurrent (I(sub c)) data is obtained from a step function drive to the diaphragm in a Helmholtz resonator cell. The superfluid density (rho(sub s)) data can be obtained from the resonant frequency of the Helmholtz oscillator, as determined by transfer function of the resonator or from the free ringing after the step function excitation. Preliminary data shows that I(sub c) is proportional to (rho(sub s))(exp 1.27) and rho(sub s)) is proportional to tau(exp 0.73), where tau is the reduced temperature. However, the magnitude of I(sub c) is much larger than expected, indicating a possible parallel flow path. Further investigations are in progress. Keywords: superfluid; hydrodynamics; critical exponent

  9. Methionine oxidation of monomeric lambda repressor: the denatured state ensemble under nondenaturing conditions.

    PubMed

    Chugha, Preeti; Sage, Harvey J; Oas, Terrence G

    2006-03-01

    Although poorly understood, the properties of the denatured state ensemble are critical to the thermodynamics and the kinetics of protein folding. The most relevant conformations to cellular protein folding are the ones populated under physiological conditions. To avoid the problem of low expression that is seen with unstable variants, we used methionine oxidation to destabilize monomeric lambda repressor and predominantly populate the denatured state under nondenaturing buffer conditions. The denatured ensemble populated under these conditions comprises conformations that are compact. Analytical ultracentrifugation sedimentation velocity experiments indicate a small increase in Stokes radius over that of the native state. A significant degree of alpha-helical structure in these conformations is detected by far-UV circular dichroism, and some tertiary interactions are suggested by near-UV circular dichroism. The characteristics of the denatured state populated by methionine oxidation in nondenaturing buffer are very different from those found in chemical denaturant.

  10. Isospin Decomposition of the Photoproduced Sigma pi System Near the Lambda(1405)

    SciTech Connect

    Schumacher, Reinhard A.; Moriya, Kei

    2013-09-01

    Recent experimental results for the reaction \\gamma + p \\to K^+ + \\Sigma + \\pi\\ from CLAS at Jefferson Lab are discussed. It was found that the mass distributions or "line shapes" of the three charge combinations \\Sigma^+ \\pi^-, \\Sigma^0 \\pi^0 and \\Sigma^- \\pi^+ differ significantly. Our results show that the \\Lambda(1405), as the I=0 constituent of the reaction, must be accompanied by an I > 0 component. We discuss phenomenological fits to the data to test the possible forms and magnitudes of these amplitudes. A two-amplitude I=0 fit of Breit-Wigner form to the \\Sigma^0\\pi^0 channel alone works quite well. The addition of a single I=1 amplitude works fairly well to model all the line shapes simultaneously.

  11. Experimental transport studies of yttrium barium copper oxide and lambda-DNA

    NASA Astrophysics Data System (ADS)

    Zhang, Yuexing

    This dissertation consists of two parts. In Part I, we focus on the quasi-particle transport properties in the high temperature superconductor YBa2Cu3O7-delta (YBCO), probed by the thermal Hall conductivity (kappa xy). The thermal Hall conductivity selectively reflects the transport behaviors of the charge carriers. By measuring kappaxy in the normal state YBCO, we established a new method to determine the Wiedemann-Franz (WF) ratio in cuprates. We determined the Hall-channel WF ratio kappa xy/sigmaxyT in Cu and YBCO. In the latter, we uncovered a T-linear dependence and suppression of the Hallchannel WF ratio. The suppression of the Hall-channel WF ratio in systems with predominant electron-electron scattering will be discussed. Thermal transport behaviors of the quasi-particles in the mixed state were studied by measuring kappaxx and kappa xy in a high-purity YBCO crystal. From the field-dependence of the thermal conductivity kappaxx, we separated the quasi particle contribution (kappae) from the phonon background. In the Hall channel, we observed that the (weak-field) kappa xy increased 103-fold between T c (90 K) and 30 K, implying a 100-fold enhancement of the quasi-particle lifetime. We found that kappaxy exhibited a specific scaling behavior below ˜30 K. The implication of the scaling behavior will be discussed. In Part II, we describe an experiment on determining the electrical conductivity of the bacteriophage lambda-DNA, an issue currently under intense debate. We covalently bonded the DNA to Au electrodes by incorporating thiol modified dTTP into the 'sticky' ends of the lambda-DNA. Two-probe measurements on such molecules provided a lower bound for the resistivity rho > 10 6 mum at bias potentials up to 20 V, in conflict with recent claims of moderate to high conductivity. We stress the importance of eliminating salt residues in these measurements.

  12. The Amazing COS FUV (1320 - 1460 A) Spectrum of (lambda) Vel (K4Ib-II)

    NASA Technical Reports Server (NTRS)

    Carpenter, Kenneth

    2010-01-01

    The FUV spectrum (1320-1460 A) of the K4 lb-11 supergiant (lambda) Vel was observed with the Cosmic Origins Spectrograph (COS) on HST, as part of the Ayres and Redfield Cycle 17 SNAP program "SNAPing Coronal Iron". This spectrum covers a region not previously recorded in (lambda) Vel at high resolution and, in a mere 20 minutes of exposure, reveals a treasure trove of information. It shows a wide variety of strong emission lines, superposed on a bright continuum, with contributions from both atomic and molecular species. Multiple absorptions, including numerous Ni II and Fe II lines, are visible over this continuum, which is likely generated in the chromosphere of the star. Evidence of the stellar wind is seen in the P Cygni profiles of the CII lines near 1335 A and the results of fluorescence processes are visible throughout the region. The spectrum has remarkable similarities to that of (alpha) Boo (K1.5 III), but significant differences as well, including substantial FUV continuum emission, reminiscent of the M2 Iab supergiant (alpha) Ori, but minus the CO fundamental absorption bands seen in the spectrum of the latter star. However, fluoresced CO emission is present, as in the K-giant stars (alpha) Boo and (alpha) Tau (K5 III). The presence of hot plasma in the atmosphere of the star, indicated by previous GHRS observations of Si III] and C III] lines near 1900 A and FUSE observations of O VI 1032 A, is further confirmed by the detection in this COS spectrum of the Si IV UV 1 lines near 1400 A, though both lines are contaminated by overlying fluorescent H2 emission. We present the details of this spectrum, in comparison with stars of similar temperature or luminosity and discuss the implications for the structure of, and the radiative processes active in, the outer atmospheres of these stars.

  13. Light element non-LTE abundances of lambda Bootis stars. II. Nitrogen and sulphur

    NASA Astrophysics Data System (ADS)

    Kamp, I.; Iliev, I. Kh.; Paunzen, E.; Pintado, O. I.; Solano, E.; Barzova, I. S.

    2001-09-01

    One of the main characteristics proclaimed for the group of the lambda Bootis stars is the apparent solar abundance of the light elements C, N, O and S. The typical abundance pattern is completed by the strong underabundances of the Fe-peak elements. In the first paper of this series, we have shown that carbon is less abundant than oxygen but both elements are still significantly more abundant than Fe-peak elements. The mean abundances, based on a detailed non-LTE investigation, were found -0.37 dex and -0.07 dex, respectively. As a further step, we now present non-LTE abundances of nitrogen and sulphur for thirteen members of the lambda Bootis group based on several spectral lines between 8590 Å, and 8750 Å. Furthermore, LTE abundances for calcium in the same spectral range were derived and compared with values from the literature. Similar to the mean abundances of carbon and oxygen, nearly solar values were found (-0.30 dex for nitrogen and -0.11 dex for sulphur) for our sample of program stars. Among our sample, one previously undetected binary system (HD 64491) was identified. From a statistical point of view, the abundances of the light elements range from slightly overabundant to moderately underabundant compared to the Sun. However, the individual objects always exhibit a similiar pattern, with the Fe-peak elements being significantly more underabundant than the light elements. No correlation of the derived abundances with astrophysical parameters such as the effective temperature, surface gravity or projected rotational velocity was found. Furthermore, the abundances of the light elements do not allow us to discriminate between any proposed theory. Based on observations obtained at BNAO Rozhen and Complejo Astronómico el Leoncito (CASLEO), operated under the agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba y San Juan.

  14. Immature surface Ig+ B cells can continue to rearrange kappa and lambda L chain gene loci

    PubMed Central

    1993-01-01

    Pro and pre B cells possess the long-term capacity to proliferate in vitro on stromal cells and interleukin 7 (IL-7) and can differentiate to surface immunoglobulin (sIg+) cells upon removal of IL-7 from the cultures. A key event in this differentiation is the extensive cell loss due to apoptosis. Because the proto-oncogene bcl-2 can promote cell survival, we established pre-B cell lines from E mu-bcl-2 transgenic mice. These pre-B cells have the same properties as those derived from non-bcl-2 transgenic mice except that they do not die by apoptosis. This allowed us to study the fate of newly formed B cells in vitro for a longer period of time. Here we show that early during the differentiation of pre-B cells, upregulation of RAG-1 and RAG-2 expression go hand in hand with rearrangements of the Ig gene loci. Moreover, the newly formed sIg+ B cells continue to express RAG-1 and RAG-2 and continue to rearrange L chain gene loci, even in the absence of proliferation, in an orderly fashion, so that kappa L+ sIg+ cells can become lambda L+ sIg+ or sIg- cells, whereas lambda L+ sIg+ cells can become sIg-, but not kappa L+ sIg+ cells. Thus, deposition of a complete Ig molecule on the surface of a B cell does not automatically stop the Ig-rearrangement machinery. PMID:8376934

  15. Interferon lambda genotype and low serum LDL cholesterol levels in patients with chronic hepatitis C infection

    PubMed Central

    Li, Josephine H.; Lao, Xiang Qian; Tillmann, Hans L.; Rowell, Jennifer; Patel, Keyur; Thompson, Alexander; Suchindran, Sunil; Muir, Andrew J.; Guyton, John R.; Gardner, Stephen D.; McHutchison, John G.; McCarthy, Jeanette J.

    2010-01-01

    Background Recently, genetic polymorphisms occurring in the interferon lambda gene region were associated with response to interferon-based treatment of hepatitis C infection. Both infection with the hepatitis C virus and interferon therapy are associated with decreased serum cholesterol and high cholesterol has been associated with increased likelihood to respond to interferon. We sought to determine if the interferon lambda gene variant was also associated with serum lipid levels in chronic hepatitis C patients. We compared genotypes of the rs12979860 polymorphism, located proximal to the IL28 gene, with serum lipid and apolipoprotein levels in 746 subjects with chronic HCV infection, not currently undergoing treatment, using multivariable analysis of variance. Results Levels of total cholesterol (p=6.0×10-4), apolipoprotein B (p=1.3×10-6) and low density lipoprotein (LDL) cholesterol (p=8.9×10-10) were significantly higher in subjects carrying the rs12979860 CC ‘responder’ genotype compared to those with the CT or TT genotype. Levels of triglycerides (p=0.03), apolipoprotein A-I (p=0.06) and apolipoprotein E (p=0.01) were slightly lower in the rs12979860 CC genotype group, while levels of high density lipoprotein cholesterol (p=0.78) and apolipoprotein C-III (p=0.74) did not vary by rs12979860 genotype. Conclusions Our results suggest that low levels of LDL cholesterol in chronic hepatitis C patients may be a marker of host endogenous interferon response to hepatitis C and that subjects with the rs12979860 CC ‘responder’ genotype may have a lower endogenous interferon response to the virus. PMID:20235331

  16. Human placenta: relative content of antibodies of different classes and subclasses (IgG1-IgG4) containing lambda- and kappa-light chains and chimeric lambda-kappa-immunoglobulins.

    PubMed

    Lekchnov, Evgenii A; Sedykh, Sergey E; Dmitrenok, Pavel S; Buneva, Valentina N; Nevinsky, Georgy A

    2015-06-01

    The specific organ placenta is much more than a filter: it is an organ that protects, feeds and regulates the growth of the embryo. Affinity chromatography, ELISA, SDS-PAGE and matrix-assisted laser desorption ionization mass spectrometry were used. Using 10 intact human placentas deprived of blood, a quantitative analysis of average relative content [% of total immunoglobulins (Igs)] was carried out for the first time: (92.7), IgA (2.4), IgM (2.5), kappa-antibodies (51.4), lambda-antibodies (48.6), IgG1 (47.0), IgG2 (39.5), IgG3 (8.8) and IgG4 (4.3). It was shown for the first time that placenta contains sIgA (2.5%). In the classic paradigm, Igs represent products of clonal B-cell populations, each producing antibodies recognizing a single antigen. There is a common belief that IgGs in mammalian biological fluids are monovalent molecules having stable structures and two identical antigen-binding sites. However, similarly to human milk Igs, placenta antibodies undergo extensive half-molecule exchange and the IgG pool consists of 43.5 ± 15.0% kappa-kappa-IgGs and 41.6 ± 17.0% lambda-lambda-IgGs, while 15.0 ± 4.0% of the IgGs contained both kappa- and lambda-light chains. Kappa-kappa-IgGs and lambda-lambda-IgGs contained, respectively (%): IgG1 (47.7 and 34.4), IgG2 (36.3 and 44.5), IgG3 (7.4 and 11.8) and IgG4 (7.5 and 9.1), while chimeric kappa-lambda-IgGs consisted of (%): 43.5 IgG1, 41.0 IgG2, 5.6 IgG3 and 7.9 IgG4. Our data are indicative of the possibility of half-molecule exchange between placenta IgGs of various subclasses, raised against different antigens, which explains a very well-known polyspecificity and cross-reactivity of different human IgGs.

  17. A new clustering strategy

    NASA Astrophysics Data System (ADS)

    Feng, Jian-xin; Tang, Jia-fu; Wang, Guang-xing

    2007-04-01

    On the basis of the analysis of clustering algorithm that had been proposed for MANET, a novel clustering strategy was proposed in this paper. With the trust defined by statistical hypothesis in probability theory and the cluster head selected by node trust and node mobility, this strategy can realize the function of the malicious nodes detection which was neglected by other clustering algorithms and overcome the deficiency of being incapable of implementing the relative mobility metric of corresponding nodes in the MOBIC algorithm caused by the fact that the receiving power of two consecutive HELLO packet cannot be measured. It's an effective solution to cluster MANET securely.

  18. Star cluster dynamics.

    PubMed

    Vesperini, Enrico

    2010-02-28

    Dynamical evolution plays a key role in shaping the current properties of star clusters and star cluster systems. A detailed understanding of the effects of evolutionary processes is essential to be able to disentangle the properties that result from dynamical evolution from those imprinted at the time of cluster formation. In this review, I focus my attention on globular clusters, and review the main physical ingredients driving their early and long-term evolution, describe the possible evolutionary routes and show how cluster structure and stellar content are affected by dynamical evolution.

  19. Gene targeting in the Ig kappa locus: efficient generation of lambda chain-expressing B cells, independent of gene rearrangements in Ig kappa.

    PubMed Central

    Zou, Y R; Takeda, S; Rajewsky, K

    1993-01-01

    The production of lambda chain-expressing B cells was studied in mice in which either the gene encoding the constant region of the kappa chain (C kappa) or the intron enhancer in the Ig kappa locus was inactivated by insertion of a neomycin resistance gene. The two mutants have similar phenotypes: in heterozygous mutant mice the fraction of lambda chain-bearing B cells is twice that in the wildtype. Homozygous mutants produce approximately 7 times more lambda-expressing B cells (and about 2.3 times fewer total B cells) in the bone marrow than their normal counterparts, suggesting that B cell progenitors can differentiate into either kappa- or lambda-producing cells and do the latter in the mutants. Whereas gene rearrangements in the Ig kappa locus are blocked in the case of enhancer inactivation, they still occur in that of the C kappa mutant, although in this mutant RS rearrangement is lower than in the wildtype. This indicates that gene rearrangements in the Ig lambda locus can occur in the absence of a putative positive signal resulting from gene rearrangements in Ig kappa, including RS recombination. Complementing these results, we also present data indicating that in normal B cell development kappa chain rearrangement can be preceded by lambda chain rearrangement and that the frequency of kappa/lambda double producers is small and insufficient to explain the massive production of lambda chain-expressing B cells in the mutants. Images PMID:8458339

  20. It's Not the Book, It's Not the Author, It's the Award: The Lambda Literary Award and the Case for Strategic Essentialism

    ERIC Educational Resources Information Center

    Crisp, Thomas

    2011-01-01

    On September 16, 2009, the Lambda Literary Foundation (LLF) released a statement revising their eligibility guidelines for the Lambda Literary Award, the most prestigious citation offered for LGBT books and authors. This criteria, which demands that an author must self-identify as a member of the LGBT family of writers, has been met with…

  1. Lethal Effects of Lambda-Cyhalothrin and Demand® CS on Asian Longhorned Beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae): Implications for Population Suppression, Tree Protection, Eradication and Containment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the 24h contact toxicity of lambda-cyhalothrin for adult Asian longhorned beetle, Anoplophora glabripennis Motschulsky, using topical application. Results showed that beetles are sensitive to lambda-cyhalothrin: the LD50 and LD90 were 0.13639 and 0.78461µg/beetle, respectively. Residual...

  2. Unconventional methods for clustering

    NASA Astrophysics Data System (ADS)

    Kotyrba, Martin

    2016-06-01

    Cluster analysis or clustering is a task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense or another) to each other than to those in other groups (clusters). It is the main task of exploratory data mining and a common technique for statistical data analysis used in many fields, including machine learning, pattern recognition, image analysis, information retrieval, and bioinformatics. The topic of this paper is one of the modern methods of clustering namely SOM (Self Organising Map). The paper describes the theory needed to understand the principle of clustering and descriptions of algorithm used with clustering in our experiments.

  3. Galaxy clusters and cold dark matter - A low-density unbiased universe?

    NASA Technical Reports Server (NTRS)

    Bahcall, Neta A.; Cen, Renyue

    1992-01-01

    Large-scale simulations of a universe dominated by cold dark matter (CDM) are tested against two fundamental properties of clusters of galaxies: the cluster mass function and the cluster correlation function. We find that standard biased CDM models are inconsistent with these observations for any bias parameter b. A low-density, low-bias CDM-type model, with or without a cosmological constant, appears to be consistent with both the cluster mass function and the cluster correlations. The low-density model agrees well with the observed correlation function of the Abell, Automatic Plate Measuring Facility (APM), and Edinburgh-Durham cluster catalogs. The model is in excellent agreement with the observed dependence of the correlation strength on cluster mean separation, reproducing the measured universal dimensionless cluster correlation. The low-density model is also consistent with other large-scale structure observations, including the APM angular galaxy-correlations, and for lambda = 1-Omega with the COBE results of the microwave background radiation fluctuations.

  4. Spectroscopic investigation of Lambda hypernuclei in the wide mass region using the (e, e-prime K+) reaction

    SciTech Connect

    Satoshi N. Nakamura

    2011-09-01

    The third generation spectroscopic study of {Lambda} hypernuclei using (e,e'K{sup +}) reaction (JLab E05-115) was performed at JLab Hall-C in 2009. The experiment introduced the newly developed high-resolution electron spectrometer (HES) with the existing high-resolution kaon spectrometer (HKS). Experimental configuration, conditions, spectrometer designs and current status of analysis are presented.

  5. Influence of selected water quality characteristics on the toxicity of lambda-cyhalothrin and gamma-cyhalothrin to Hyalella azteca

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to assess the influence of suspended solids, dissolved organic carbon, and phytoplankton (as chlorophyll a) water quality characteristics on lambda-cyhalothrin and gamma-cyhalothrin aqueous toxicity to Hyalella azteca using natural water from 12 ponds and lakes in Mississipp...

  6. Influence of the germline sequence on the thermodynamic stability and fibrillogenicity of human lambda 6 light chains.

    PubMed

    del Pozo Yauner, Luis; Ortiz, Ernesto; Sánchez, Rosalba; Sánchez-López, Rosana; Güereca, Leopoldo; Murphy, Charles L; Allen, Amy; Wall, Jonathan S; Fernández-Velasco, D Alejandro; Solomon, Alan; Becerril, Baltazar

    2008-08-01

    Light chain-associated amyloidosis is a fatal disease characterized by the aggregation and pathologic deposition of monoclonal light chain-related fragments as amyloid fibrils in organs or tissues throughout the body. Notably, it has been observed that proteins encoded by the lambda variable light chain (V(L)) gene segment 6a are invariably associated with amyloid deposition; however, the contribution of the gene to this phenomenon has not been established. In this regard, we have determined the thermodynamic stability and kinetics of in vitro fibrillogenesis of a recombinant (r) V(L) protein, designated 6aJL2, which contains the predicted sequences encoded by the 6a and JL2 germline genes. Additionally, we studied a 6a mutant (6aJL2-Arg25Gly), that is present in approximately 25% of all amyloid-associated lambda6 light chains. Remarkably, the wild-type 6aJL2 protein was more stable than were all known amyloidogenic kappa and lambda light chains for which stability parameters are available; more importantly, it was even more so (and less fibrillogenic) than the only clinically proven nonamyloidogenic lambda6 protein, Jto. Conversely, the mutated 6aJL2-R25G molecule was considerably less stable and more fibrillogenic than was the native 6aJL2. Our data indicate that the propensity of lambda6 light chains to form amyloid can not be attributed to thermodynamic instability of the germline-encoded Vlambda6 domain, but rather, is dependent on sequence alterations that render such proteins amyloidogenic.

  7. Fuzzy Subspace Clustering

    NASA Astrophysics Data System (ADS)

    Borgelt, Christian

    In clustering we often face the situation that only a subset of the available attributes is relevant for forming clusters, even though this may not be known beforehand. In such cases it is desirable to have a clustering algorithm that automatically weights attributes or even selects a proper subset. In this paper I study such an approach for fuzzy clustering, which is based on the idea to transfer an alternative to the fuzzifier (Klawonn and Höppner, What is fuzzy about fuzzy clustering? Understanding and improving the concept of the fuzzifier, In: Proc. 5th Int. Symp. on Intelligent Data Analysis, 254-264, Springer, Berlin, 2003) to attribute weighting fuzzy clustering (Keller and Klawonn, Int J Uncertain Fuzziness Knowl Based Syst 8:735-746, 2000). In addition, by reformulating Gustafson-Kessel fuzzy clustering, a scheme for weighting and selecting principal axes can be obtained. While in Borgelt (Feature weighting and feature selection in fuzzy clustering, In: Proc. 17th IEEE Int. Conf. on Fuzzy Systems, IEEE Press, Piscataway, NJ, 2008) I already presented such an approach for a global selection of attributes and principal axes, this paper extends it to a cluster-specific selection, thus arriving at a fuzzy subspace clustering algorithm (Parsons, Haque, and Liu, 2004).

  8. Alkali Metal Cluster Theory.

    NASA Astrophysics Data System (ADS)

    Chen, Jian

    Available from UMI in association with The British Library. Requires signed TDF. In this thesis, we apply the tight-binding Hubbard model to alkali metal clusters with Hartree-Fock self-consistent methods and perturbation methods for the numerical calculations. We have studied the relation between the equilibrium structures and the range of the hopping matrix elements in the Hubbard Hamiltonian. The results show that the structures are not sensitive to the interaction range but are determined by the number of valence electrons each atom has. Inertia tensors are used to analyse the symmetries of the clusters. The principal axes of the clusters are determined and they are the axes of rotational symmetries of clusters if the clusters have any. The eigenvalues of inertia tensors which are the indication of the deformation of clusters are compared between our model and the ellipsoidal jellium model. The agreement is good for large clusters. At a finite temperature, the thermal motion fluctuates the structures. We defined a fluctuation function with the distance matrix of a cluster. The fluctuation has been studied with the Monte-Carlo simulation method. Our studies show that the clusters remain in the solid state when temperature is low. The small values of fluctuation functions indicates the thermal vibration of atoms around their equilibrium positions. If the temperature is high, the atoms are delocalized. The cluster melts and enters the liquid region. The cluster melting is simulated by the Monte-Carlo simulation with the fluctuation function we defined. Energy levels of clusters are calculated from the Hubbard model. Ionization potentials and magic numbers are also obtained from these energy levels. The results confirm that the Hubbard model is a good approximation for a small cluster. The excitation energy is presented by the difference between the original level and excited level, and the electron-hole interactions. We also have studied cooling of clusters

  9. Multistep Ionization of Argon Clusters in Intense Femtosecond Extreme Ultraviolet Pulses

    SciTech Connect

    Bostedt, C.; Thomas, H.; Hoener, M.; Eremina, E.; Fennel, T.; Meiwes-Broer, K.-H.; Wabnitz, H.; Kuhlmann, M.; Ploenjes, E.; Tiedtke, K.; Treusch, R.; Feldhaus, J.; Castro, A. R. B. de; Moeller, T.

    2008-04-04

    The interaction of intense extreme ultraviolet femtosecond laser pulses ({lambda}=32.8 nm) from the FLASH free electron laser (FEL) with clusters has been investigated by means of photoelectron spectroscopy and modeled by Monte Carlo simulations. For laser intensities up to 5x10{sup 13} W/cm{sup 2}, we find that the cluster ionization process is a sequence of direct electron emission events in a developing Coulomb field. A nanoplasma is formed only at the highest investigated power densities where ionization is frustrated due to the deep cluster potential. In contrast with earlier studies in the IR and vacuum ultraviolet spectral regime, we find no evidence for electron emission from plasma heating processes.

  10. Generation of strongly coupled Xe cluster nanoplasmas by low intensive soft x-ray laser irradiation

    SciTech Connect

    Namba, S.; Hasegawa, N.; Kishimoto, M.; Nishikino, M.; Kawachi, T.

    2012-07-11

    A seeding gas jet including Xe clusters was irradiated with a laser-driven plasma soft x-ray laser pulse ({lambda}=13.9 nm, {approx}7 ps, {<=}5 Multiplication-Sign 10{sup 9} W/cm{sup 2}), where the laser photon energy is high enough to ionize 4d core electrons. In order to clarify how the innershell ionization followed by the Auger electron emission is affected under the intense laser irradiation, the electron energy distribution was measured. Photoelectron spectra showed that the peak position attributed to 4d hole shifted to lower energy and the spectral width was broadened with increasing cluster size. Moreover, the energy distribution exhibited that a strongly coupled cluster nanoplasma with several eV was generated.

  11. Information-based clustering

    PubMed Central

    Slonim, Noam; Atwal, Gurinder Singh; Tkačik, Gašper; Bialek, William

    2005-01-01

    In an age of increasingly large data sets, investigators in many different disciplines have turned to clustering as a tool for data analysis and exploration. Existing clustering methods, however, typically depend on several nontrivial assumptions about the structure of data. Here, we reformulate the clustering problem from an information theoretic perspective that avoids many of these assumptions. In particular, our formulation obviates the need for defining a cluster “prototype,” does not require an a priori similarity metric, is invariant to changes in the representation of the data, and naturally captures nonlinear relations. We apply this approach to different domains and find that it consistently produces clusters that are more coherent than those extracted by existing algorithms. Finally, our approach provides a way of clustering based on collective notions of similarity rather than the traditional pairwise measures. PMID:16352721

  12. Clusters of galaxies

    NASA Astrophysics Data System (ADS)

    Vikhlinin, A. A.; Kravtsov, A. V.; Markevich, M. L.; Sunyaev, R. A.; Churazov, E. M.

    2014-04-01

    Galaxy clusters are formed via nonlinear growth of primordial density fluctuations and are the most massive gravitationally bound objects in the present Universe. Their number density at different epochs and their properties depend strongly on the properties of dark matter and dark energy, making clusters a powerful tool for observational cosmology. Observations of the hot gas filling the gravitational potential well of a cluster allows studying gasdynamic and plasma effects and the effect of supermassive black holes on the heating and cooling of gas on cluster scales. The work of Yakov Borisovich Zeldovich has had a profound impact on virtually all cosmological and astrophysical studies of galaxy clusters, introducing concepts such as the Harrison-Zeldovich spectrum, the Zeldovich approximation, baryon acoustic peaks, and the Sunyaev-Zeldovich effect. Here, we review the most basic properties of clusters and their role in modern astrophysics and cosmology.

  13. Chemistry Within Molecular Clusters

    DTIC Science & Technology

    1990-01-01

    DME )nCH3OCH 2 +). We speculate that this is due to the fragments being consumed by an ion-molecule reaction within the cluster. One likely candidate is...the ion-molecule reaction of the fragment cations with a neutral DME , within the bulk cluster to form a trimethyloxonlum cation intermediate. This...the observed products. We therefore speculate that the DME cluster reactions leading to the same products, should involve the same mechanism found to

  14. Chemistry Within Molecular Clusters

    DTIC Science & Technology

    1992-06-01

    and ( DME ).CH 3OCH2+). We speculate that this is due to the fragments being consumed by an ion-molecule reaction within the cluster. A likely candidate...is the ion-molecule reaction of the fragment cations with a neutral DME within the bulk cluster, to form a trimethyloxonium cation intermediate...a trimethyloxonium intermediate as the common intermediate for the observed products. We therefore speculate that the DME cluster reactions leading to

  15. Cluster State Quantum Computation

    DTIC Science & Technology

    2014-02-01

    nearest neighbor cluster state has been shown to be a universal resource for MBQC thus we can say our quantum computer is universal. We note that...CLUSTER STATE QUANTUM COMPUTATION FEBRUARY 2014 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED STINFO COPY AIR FORCE...TITLE AND SUBTITLE CLUSTER STATE QUANTUM COMPUTATION 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER 62788F 6

  16. Chemical Reactions in Clusters

    DTIC Science & Technology

    1992-11-04

    NH 3)n, n _> 4, clusters has been attributed to the (solvated) naphtholate anion.3a A single picosecond decay measurement has been reported which...vibrational energy in the cluster Sl state. The data are summarized in Table I. A model to explain these decay results can be constructed based on a proton...11 TITLE (Include Security Classification) Chemical Reactions in Clusters 12 PERSONAL AUTHOR(S) Elliot R. Bernstein 13a TYPE OF REPORT 13b TIME COVERED

  17. Star Clusters within FIRE

    NASA Astrophysics Data System (ADS)

    Perez, Adrianna; Moreno, Jorge; Naiman, Jill; Ramirez-Ruiz, Enrico; Hopkins, Philip F.

    2017-01-01

    In this work, we analyze the environments surrounding star clusters of simulated merging galaxies. Our framework employs Feedback In Realistic Environments (FIRE) model (Hopkins et al., 2014). The FIRE project is a high resolution cosmological simulation that resolves star forming regions and incorporates stellar feedback in a physically realistic way. The project focuses on analyzing the properties of the star clusters formed in merging galaxies. The locations of these star clusters are identified with astrodendro.py, a publicly available dendrogram algorithm. Once star cluster properties are extracted, they will be used to create a sub-grid (smaller than the resolution scale of FIRE) of gas confinement in these clusters. Then, we can examine how the star clusters interact with these available gas reservoirs (either by accreting this mass or blowing it out via feedback), which will determine many properties of the cluster (star formation history, compact object accretion, etc). These simulations will further our understanding of star formation within stellar clusters during galaxy evolution. In the future, we aim to enhance sub-grid prescriptions for feedback specific to processes within star clusters; such as, interaction with stellar winds and gas accretion onto black holes and neutron stars.

  18. Melting of nickel clusters

    SciTech Connect

    Garzon, I.L.; Jellinek, J.

    1991-12-31

    The meltinglike phenomenon in Ni{sub n}, n = 19,20,55, clusters is studied using microcanonical molecular dynamics simulations. The interaction between the atoms in the clusters is modelled by a size-dependent Gupta-like potential that incorporates many-body effects. The clusters display the ``usual`` stages in their meltinglike transition, which characterize also Lennard-Jones (e.g., noble gas) and ionic clusters. In addition, Ni{sub 20} passes through a so-called premelting stage found earlier also for Ni{sub 14}. 11 ref., 3 figs.

  19. Melting of nickel clusters

    SciTech Connect

    Garzon, I.L. . Inst. de Fisica); Jellinek, J. )

    1991-01-01

    The meltinglike phenomenon in Ni{sub n}, n = 19,20,55, clusters is studied using microcanonical molecular dynamics simulations. The interaction between the atoms in the clusters is modelled by a size-dependent Gupta-like potential that incorporates many-body effects. The clusters display the usual'' stages in their meltinglike transition, which characterize also Lennard-Jones (e.g., noble gas) and ionic clusters. In addition, Ni{sub 20} passes through a so-called premelting stage found earlier also for Ni{sub 14}. 11 ref., 3 figs.

  20. Mini-clusters

    NASA Technical Reports Server (NTRS)

    Chinellato, J. A.; Dobrigkeit, C.; Bellandifilho, J.; Lattes, C. M. G.; Menon, M. J.; Navia, C. E.; Pamilaju, A.; Sawayanagi, K.; Shibuya, E. H.; Turtelli, A., Jr.

    1985-01-01

    Experimental results of mini-clusters observed in Chacaltaya emulsion chamber no.19 are summarized. The study was made on 54 single core shower upper and 91 shower clusters of E(gamma) 10 TeV from 30 families which are visible energy greater than 80 TeV and penetrate through both upper and lower detectors of the two-story chamber. The association of hadrons in mini-cluster is made clear from their penetrative nature and microscopic observation of shower continuation in lower chamber. Small P sub t (gamma) of hadrons in mini-clusters remained in puzzle.

  1. Clustering versus non-clustering phase synchronizations

    SciTech Connect

    Liu, Shuai; Zhan, Meng

    2014-03-15

    Clustering phase synchronization (CPS) is a common scenario to the global phase synchronization of coupled dynamical systems. In this work, a novel scenario, the non-clustering phase synchronization (NPS), is reported. It is found that coupled systems do not transit to the global synchronization until a certain sufficiently large coupling is attained, and there is no clustering prior to the global synchronization. To reveal the relationship between CPS and NPS, we further analyze the noise effect on coupled phase oscillators and find that the coupled oscillator system can change from CPS to NPS with the increase of noise intensity or system disorder. These findings are expected to shed light on the mechanism of various intriguing self-organized behaviors in coupled systems.

  2. Varying alpha/lambda in NLC Structures--BNS Damping and Emittance Growth(LCC-0063)

    SciTech Connect

    Stupakov, G

    2003-12-03

    In this note we consider the effect of the varying the iris opening {alpha} in the NLC structures on the beam dynamics and the RF efficiency in the linac. The most important consequence of the variation of the iris openings is the change of the longitudinal and transverse wakefields. Wake as a function of parameter {alpha} for the NLC structures has been previously calculated by K. Bane. Here we will use his result for the scalings of the longitudinal wake w{sub l} and transverse wake w{sub t} with the geometrical dimensions of the structure: w{sub l}(s) = Z{sub 0}c/{pi}{alpha}{sup 2} e{radical}(s/s{sub 0}), dw{sub t}(s)/ds = 2Z{sub 0}c/{pi}{alpha}{sup 4} e{sup -} {radical}(s/s{sub 1}) where for the scaling parameters s{sub 0} and s{sub 1} we have s{sub 0} = 0.41 a{sup 1.8}g{sup 1.6}/L{sup 2.4}, s{sub 1} = ({alpha}[m]){sup 1.96}, with g being the distance between the irises (gap) and L - the cell period (equal to the gap plus the iris thickness). The above formulas were derived assuming 2{pi}/3 phase advance between the structure cells. The wakefields were calculated assuming g = 7.09 mm and L = 8.75 mm and four different ratios of {alpha}/{lambda} = 0.18, 0.17, 0.16, 0.15 ({lambda} = 2.62 cm corresponding to the frequency 11.424 GHz). The plots of the longitudinal and transverse wakes are shown in Fig. 1 and 2. The beams dynamics in the NLC lattice (linac.cd1.1.trans) was simulated using the LIAR code for the nominal case with the following parameters: initial beam energy--10 GeV, final beam energy--500 GeV, number of particles in the bunch--10{sup 10}, normalized vertical beam emittance at the entrance to the linac--3 {center_dot} 10{sup -8} m, and the rms bunch length--150 {micro}m.

  3. Galaxy Cluster Gas Mass Fractions From Sunyaev-Zeldovich Effect Measurements: Constraints on Omega(M)

    NASA Technical Reports Server (NTRS)

    Grego, Laura; Carlstrom, John E.; Reese, Erik D.; Holder, Gilbert P.; Holzapfel, William L.; Joy, Marshall K.; Mohr, Joseph J.; Patel, Sandeep

    2001-01-01

    Using sensitive centimeter-wave receivers mounted on the Owens Valley Radio Observatory and Berkeley-Illinois-Maryland-Association millimeter arrays, we have obtained interferometric measurements of the Sunyaev-Zeldovich(SZ) effect toward massive galaxy clusters. We use the SZ data to determine the pressure distribution of the cluster gas and, in combination with published X-ray temperatures, to infer the gas mass and total gravitational mass of 18 clusters. The gas mass fraction, f(g), is calculated for each cluster and is extrapolated to the fiducial radius r(500) using the results of numerical simulations. The mean f(g) within r(500) is 0.081(+ 0.009 / - 0.011) per h(100) (statistical uncertainty at 68% confidence level, assuming Omega(M) = 0.3, Omega(Lambda) = 0.7). We discuss possible sources of systematic errors in the mean f(sub g) measurement. We derive an upper limit for Omega(M) from this sample under the assumption that the mass composition of clusters within r(500) reflects the universal mass composition: Omega(M)h is less than or equal to Omega(B)/f(g). The gas mass fractions depend on cosmology through the angular diameter distance and the r(500) correction factors. For a flat universe (Omega(Lambda) is identical with 1 - Omega(M)) and h = 0.7, we find the measured gas mass fractions are consistent with Omega(M) is less than 0.40, at 68% confidence. Including estimates of the baryons contained in galaxies and the baryons which failed to become bound during the cluster formation process, we find Omega(M) is approximately equal to 0.25.

  4. Weak-lensing Mass Calibration of RedMaPPer Galaxy Clusters in Dark Energy Survey Science Verification Data

    SciTech Connect

    Melchior, P.; et al.

    2016-10-21

    We use weak-lensing shear measurements to determine the mean mass of optically selected galaxy clusters in Dark Energy Survey Science Verification data. In a blinded analysis, we split the sample of more than 8,000 redMaPPer clusters into 15 subsets, spanning ranges in the richness parameter $5 \\leq \\lambda \\leq 180$ and redshift $0.2 \\leq z \\leq 0.8$, and fit the averaged mass density contrast profiles with a model that accounts for seven distinct sources of systematic uncertainty: shear measurement and photometric redshift errors; cluster-member contamination; miscentering; deviations from the NFW halo profile; halo triaxiality; and line-of-sight projections. We combine the inferred cluster masses to estimate the joint scaling relation between mass, richness and redshift, $\\mathcal{M}(\\lambda,z) \\varpropto M_0 \\lambda^{F} (1+z)^{G}$. We find $M_0 \\equiv \\langle M_{200\\mathrm{m}}\\,|\\,\\lambda=30,z=0.5\\rangle=\\left[ 2.35 \\pm 0.22\\ \\rm{(stat)} \\pm 0.12\\ \\rm{(sys)} \\right] \\cdot 10^{14}\\ M_\\odot$, with $F = 1.12\\,\\pm\\,0.20\\ \\rm{(stat)}\\, \\pm\\, 0.06\\ \\rm{(sys)}$ and $G = 0.18\\,\\pm\\, 0.75\\ \\rm{(stat)}\\, \\pm\\, 0.24\\ \\rm{(sys)}$. The amplitude of the mass-richness relation is in excellent agreement with the weak-lensing calibration of redMaPPer clusters in SDSS by Simet et al. (2016) and with the Saro et al. (2015) calibration based on abundance matching of SPT-detected clusters. Our results extend the redshift range over which the mass-richness relation of redMaPPer clusters has been calibrated with weak lensing from $z\\leq 0.3$ to $z\\leq0.8$. Calibration uncertainties of shear measurements and photometric redshift estimates dominate our systematic error budget and require substantial improvements for forthcoming studies.

  5. A modified recombineering protocol for the genetic manipulation of gene clusters in Aspergillus fumigatus.

    PubMed

    Alcazar-Fuoli, Laura; Cairns, Timothy; Lopez, Jordi F; Zonja, Bozo; Pérez, Sandra; Barceló, Damià; Igarashi, Yasuhiro; Bowyer, Paul; Bignell, Elaine

    2014-01-01

    Genomic analyses of fungal genome structure have revealed the presence of physically-linked groups of genes, termed gene clusters, where collective functionality of encoded gene products serves a common biosynthetic purpose. In multiple fungal pathogens of humans and plants gene clusters have been shown to encode pathways for biosynthesis of secondary metabolites including metabolites required for pathogenicity. In the major mould pathogen of humans Aspergillus fumigatus, multiple clusters of co-ordinately upregulated genes were identified as having heightened transcript abundances, relative to laboratory cultured equivalents, during the early stages of murine infection. The aim of this study was to develop and optimise a methodology for manipulation of gene cluster architecture, thereby providing the means to assess their relevance to fungal pathogenicity. To this end we adapted a recombineering methodology which exploits lambda phage-mediated recombination of DNA in bacteria, for the generation of gene cluster deletion cassettes. By exploiting a pre-existing bacterial artificial chromosome (BAC) library of A. fumigatus genomic clones we were able to implement single or multiple intra-cluster gene replacement events at both subtelomeric and telomere distal chromosomal locations, in both wild type and highly recombinogenic A. fumigatus isolates. We then applied the methodology to address the boundaries of a gene cluster producing a nematocidal secondary metabolite, pseurotin A, and to address the role of this secondary metabolite in insect and mammalian responses to A. fumigatus challenge.

  6. A Modified Recombineering Protocol for the Genetic Manipulation of Gene Clusters in Aspergillus fumigatus

    PubMed Central

    Alcazar-Fuoli, Laura; Cairns, Timothy; Lopez, Jordi F.; Zonja, Bozo; Pérez, Sandra; Barceló, Damià; Igarashi, Yasuhiro; Bowyer, Paul; Bignell, Elaine

    2014-01-01

    Genomic analyses of fungal genome structure have revealed the presence of physically-linked groups of genes, termed gene clusters, where collective functionality of encoded gene products serves a common biosynthetic purpose. In multiple fungal pathogens of humans and plants gene clusters have been shown to encode pathways for biosynthesis of secondary metabolites including metabolites required for pathogenicity. In the major mould pathogen of humans Aspergillus fumigatus, multiple clusters of co-ordinately upregulated genes were identified as having heightened transcript abundances, relative to laboratory cultured equivalents, during the early stages of murine infection. The aim of this study was to develop and optimise a methodology for manipulation of gene cluster architecture, thereby providing the means to assess their relevance to fungal pathogenicity. To this end we adapted a recombineering methodology which exploits lambda phage-mediated recombination of DNA in bacteria, for the generation of gene cluster deletion cassettes. By exploiting a pre-existing bacterial artificial chromosome (BAC) library of A. fumigatus genomic clones we were able to implement single or multiple intra-cluster gene replacement events at both subtelomeric and telomere distal chromosomal locations, in both wild type and highly recombinogenic A. fumigatus isolates. We then applied the methodology to address the boundaries of a gene cluster producing a nematocidal secondary metabolite, pseurotin A, and to address the role of this secondary metabolite in insect and mammalian responses to A. fumigatus challenge. PMID:25372385

  7. A nonparametric clustering technique which estimates the number of clusters

    NASA Technical Reports Server (NTRS)

    Ramey, D. B.

    1983-01-01

    In applications of cluster analysis, one usually needs to determine the number of clusters, K, and the assignment of observations to each cluster. A clustering technique based on recursive application of a multivariate test of bimodality which automatically estimates both K and the cluster assignments is presented.

  8. Galaxy clustering constraints on deviations from Newtonian gravity at cosmological scales

    SciTech Connect

    Shirata, Akihito; Shiromizu, Tetsuya; Yoshida, Naoki; Suto, Yasushi

    2005-03-15

    In spite of the growing observational evidence for dark matter and dark energy in the universe, their physical nature is largely unknown. In fact, several authors have proposed modifications of Newton's law of gravity at cosmological scales to account for the apparent acceleration of the cosmic expansion. Inspired by such suggestions, we attempt to constrain possible deviations from Newtonian gravity by means of the clustering of SDSS (Sloan Digital Sky Survey) galaxies. To be specific, we assume a simple modification of Newton's law with an additional Yukawa-type term characterized by the amplitude {alpha} and the length scale {lambda}. Adopting spatially-flat universes dominated by cold dark matter and/or dark energy, we solve a linear perturbation equation for the growth of density fluctuations. In particular, we find an exact analytic solution for the Einstein-de Sitter case. Following the Peacock-Dodds prescription, we compute the nonlinear power spectra of mass fluctuations, perform a statistical comparison with the SDSS galaxy data, and derive constraints in the {alpha}-{lambda} plane; for instance, we obtain the constraints of -0.5<{alpha}<0.6 and -0.8<{alpha}<0.9 (99.7% confidence level) for {lambda}=5h{sup -1} Mpc and 10h{sup -1} Mpc, respectively. We also discuss several future possibilities for improving our analysis.

  9. SPT-CL J2040–4451: An SZ-selected galaxy cluster at x=1.478 with significant ongoing star formation

    SciTech Connect

    Bayliss, M. B.; Ashby, M. L. N.; Ruel, J.; Brodwin, M.; Aird, K. A.; Bautz, M. W.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dobbs, M. A.; Dudley, J. P.; Foley, R. J.; Forman, W. R.; George, E. M.; Gettings, D.; Gladders, M. D.; Gonzalez, A. H.; de Haan, T.; Halverson, N. W.; High, F. W.; Holder, G. P.; Holzapfel, W. L.; Hoover, S.; Hrubes, J. D.; Jones, C.; Joy, M.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; Mawatari, K.; McDonald, M.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Miller, E. D.; Mocanu, L.; Mohr, J. J.; Montroy, T. E.; Murray, S. S.; Padin, S.; Plagge, T.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Song, J.; Stalder, B.; Šuhada, R.; Spieler, H. G.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K.; Stubbs, C. W.; van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.

    2014-09-18

    SPT-CL J2040-4451-spectroscopically confirmed at z = 1.478-is the highest-redshift galaxy cluster yet discovered via the Sunyaev-Zel'dovich effect. SPT-CL J2040-4451 was a candidate galaxy cluster identified in the first 720 deg(2) of the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey, and has been confirmed in follow-up imaging and spectroscopy. From multi-object spectroscopy with Magellan-I/Baade+ IMACS we measure spectroscopic redshifts for 15 cluster member galaxies, all of which have strong [O Pi]lambda lambda 3727 emission. SPT-CL J2040-4451 has an SZ-measured mass of M-500,(SZ) = 3.2 ± 0.8 x 1014M(circle dot) h(-1) 70, corresponding to M-200,M- (SZ) = 5.8 ± 1.4 x 1014M(circle dot) h(70-)(1.) The velocity dispersion measured entirely from blue star-forming members is sv = 1500 ± 520 km s-1. The prevalence of star-forming cluster members (galaxies with > 1.5M(circle dot) yr-1 implies that this massive, high-redshift cluster is experiencing a phase of active star formation, and supports recent results showing a marked increase in star formation occurring in galaxy clusters at z greater than or similar to 1.4. We also compute the probability of finding a cluster as rare as this in the SPT-SZ survey to be > 99%, indicating that its discovery is not in tension with the concordance Lambda CDM cosmological model.

  10. An improved recombineering approach by adding RecA to lambda Red recombination.

    PubMed

    Wang, Junping; Sarov, Mihail; Rientjes, Jeanette; Fu, Jun; Hollak, Heike; Kranz, Harald; Xie, Wei; Stewart, A Francis; Zhang, Youming

    2006-01-01

    Recombineering is the use of homologous recombination in Escherichia coli for DNA engineering. Of several approaches, use of the lambda phage Red operon is emerging as the most reliable and flexible. The Red operon includes three components: Redalpha, a 5' to 3' exonuclease, Redbeta, an annealing protein, and Redgamma, an inhibitor of the major E. coli exonuclease and recombination complex, RecBCD. Most E. coli cloning hosts are recA deficient to eliminate recombination and therefore enhance the stability of cloned DNAs. However, loss of RecA also impairs general cellular integrity. Here we report that transient RecA co-expression enhances the total number of successful recombinations in bacterial artificial chromosomes (BACs), mostly because the E. coli host is more able to survive the stresses of DNA transformation procedures. We combined this practical improvement with the advantages of a temperature-sensitive version of the low copy pSC101 plasmid to develop a protocol that is convenient and more efficient than any recombineering procedure, for use of either double- or single-stranded DNA, published to date.

  11. Application of LAMBDA Method to the Calculation of Slant Path Wet Vapor Content of GPS Signals

    NASA Astrophysics Data System (ADS)

    Huang, Shan-Qi; Wang, Jie-Xian; Wang, Xiao-Ya; Chen, Jun-Ping

    2009-10-01

    With the improvement of the GPS data processing techniques and calculating accuracy, the GPS has been increasingly and widely applied to atmospheric science. In the research on GPS meteorology the slant path wet vapor content (SWV) is one of the significant parameters. In the light of the problem of poorer real time, which existed in the method proposed by Song Shuli et al. in 2004, for directly calculating the SWV by means of the precise ephemeris, IGS clock error and observed value of the LC combination after the cycle skip processing, the LAMBDA method which has more mature application to the city virtual reference station (VRS) is applied to the problem of the processing of ambiguity search. Through the trial calculation of data, it is tested and verified that the method is feasible and there is a better uniformity when the calculated result is projected into the zenith direction. The atmospheric delay in the vertical direction obtained by using this method is compared with the result of the GAMIT or the BERNESE, with the result showing that the accuracy of the coincidence of the result of the method with that of the BERNESE is generally smaller than 1.5 cm and the accuracy of the coincidence of the result of the method with that of the GAMIT is generally smaller than 10 cm.

  12. The application of the LAMBDA method in the estimation of the GPS slant wet vapour

    NASA Astrophysics Data System (ADS)

    Huang, S. Q.; Wang, J. X.; Wang, X. Y.; Chen, J. P.

    2009-01-01

    By far, the technology of GPS data processing has been improved well and the accuracy of this processing has increased greatly. So, GPS has been applied in meteorology widely.The SWV (Slant Wet Vapour) is a very important parameter in the GPS meteorology. In 2004, Song Shuli had advanced a SWV estimation method which used the precision orbit of JPL, IGS clock and the LC observations without cycle-slip. But this method is bad in real-time character. LAMBDA method, which is working well in the VRS (Virtual Reference Station) /COORS, is used in the ambiguity estimation. The method was proved by some true data calculation. The ZTD(Zenith Time Delay), which is calculated by projecting SWD (Slant Wet Delay) to zenith direction, has good coherence. Compairing the ZTD with the results of GAMIT and BERNESE, the deviation between our result and the GAMIT one is commonly little than 3cm, and the BERNESE one is commonly little than 1.5cm.

  13. Revisiting Bistability in the Lysis/Lysogeny Circuit of Bacteriophage Lambda

    PubMed Central

    Bednarz, Michael; Halliday, Jennifer A.; Herman, Christophe; Golding, Ido

    2014-01-01

    The lysis/lysogeny switch of bacteriophage lambda serves as a paradigm for binary cell fate decision, long-term maintenance of cellular state and stimulus-triggered switching between states. In the literature, the system is often referred to as “bistable.” However, it remains unclear whether this term provides an accurate description or is instead a misnomer. Here we address this question directly. We first quantify transcriptional regulation governing lysogenic maintenance using a single-cell fluorescence reporter. We then use the single-cell data to derive a stochastic theoretical model for the underlying regulatory network. We use the model to predict the steady states of the system and then validate these predictions experimentally. Specifically, a regime of bistability, and the resulting hysteretic behavior, are observed. Beyond the steady states, the theoretical model successfully predicts the kinetics of switching from lysogeny to lysis. Our results show how the physics-inspired concept of bistability can be reliably used to describe cellular phenotype, and how an experimentally-calibrated theoretical model can have accurate predictive power for cell-state switching. PMID:24963924

  14. First Measurement of Transferred Polarization in the Exclusive e p --> e' K+ Lambda Reaction

    SciTech Connect

    Daniel S. Carman; Et. Al.

    2003-04-04

    The first measurements of the transferred polarization for the exclusive {rvec e}p {yields} e{prime}K{sup +}{rvec {Lambda}} reaction have been performed in Hall B at the Thomas Jefferson National Accelerator Facility using the CLAS spectrometer. A 2.567 GeV electron beam was used to measure the hyperon polarization over a range of Q{sup 2} from 0.3 to 1.5 (GeV/c){sup 2}, W from 1.6 to 2.15 GeV, and over the full center-of-mass angular range of the K{sup +} meson. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. A non-relativistic quark model interpretation of our data suggests that the s{bar s} quark pair is produced with spins predominantly anti-aligned. Implications for the validity of the widely used {sup 3}P{sub o} quark-pair creation operator are discussed.

  15. Queering the politics of lambda picture book finalists: challenging creeping neoliberalism through curricular innovations.

    PubMed

    Shimanoff, Susan B; Elia, John P; Yep, Gust A

    2012-01-01

    In many instances, adults serve as gatekeepers for what books children are permitted to explore. Unfortunately, this means that most children have limited access to picture books with lesbian, gay, bisexual, transgender, and queer (LGBTQ) characters. In this article, we use queer pedagogy and observations about neoliberalism to provide a qualitative analysis of LGBTQ characters in picture books which were finalists for a Lambda Literary Award during 2000-2005. We examined the ways in which LGBTQ identities and relationships are negotiated and how sexual prejudice is treated. While it is improbable that the books we analyze would be embraced by proponents of neoliberalism, we also briefly consider some ways in which they may be inadvertently consistent with that perspective. The article closes with recommendations regarding discussion questions, additional readings, and educational activities aimed at guiding children, and adults, to appreciate a diversity of multidimensional identities and family structures, to develop strategies to respond constructively to emotional and physical violence, and to promote the public wellbeing. We hope that this analysis will lead to more frequent, productive, and expansive discussions of this literature among adults and children.

  16. Lambda-Chain Production in Human Lymphoblast-Mouse Fibroblast Hybrids

    PubMed Central

    Orkin, Stuart H.; Buchanan, Philip D.; Yount, William J.; Reisner, Howard; Littlefield, John W.

    1973-01-01

    Mutant human lymphoblast cells deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) activity were hybridized with thymidine kinase (EC 2.7.1.21)-deficient mouse fibroblasts. Hybrid cells were readily selected, as both parental lines were nonreverting and eliminated by hypoxanthine-amethopterinthymidine medium. Human lambda (λ) chain was the only immunoglobulin chain produced by the lymphoblast parent, as determined by immunofluorescent techniques. Two independent hybrid clones chosen for detailed study synthesized human λ chain, and continued to do so after prolonged culture. As in both parental lines, no human immunoglobulin heavy chains, complements C3 or C4, or α1-antitrypsin, or mouse immunoglobulin chains or complement C5 were detectable in the hybrids. Selection against thymidine kinase-containing hybrid cells with 5-bromodeoxyuridine did not eliminate positive λ-chain reactivity, suggesting that the kinase and λ-chain loci are not linked. The continued production of an immunoglobulin chain by human lymphoblast-mouse fibroblast hybrids contrasts with the extinction of other differentiated functions in several hybrid systems, and indicates that gene localization and linkage analysis for human immunoglobulin chains should be feasible with this system. Images PMID:4599625

  17. Genetic Analysis of the Lambda Spanins Rz and Rz1: Identification of Functional Domains

    PubMed Central

    Cahill, Jesse; Rajaure, Manoj; O’Leary, Chandler; Sloan, Jordan; Marrufo, Armando; Holt, Ashley; Kulkarni, Aneesha; Hernandez, Oscar; Young, Ry

    2016-01-01

    Coliphage lambda proteins Rz and Rz1 are the inner membrane and outer membrane subunits of the spanin complex—a heterotetramer that bridges the periplasm and is essential for the disruption of the outer membrane during phage lysis. Recent evidence suggests the spanin complex functions by fusing the inner and outer membrane. Here, we use a genetics approach to investigate and characterize determinants of spanin function. Because Rz1 is entirely embedded in the +1 reading frame of Rz, the genes were disembedded before using random mutagenesis to construct a library of lysis-defective alleles for both genes. Surprisingly, most of the lysis-defective missense mutants exhibited normal accumulation or localization in vivo, and also were found to be normal for complex formation in vitro. Analysis of the distribution and nature of single missense mutations revealed subdomains that resemble key motifs in established membrane-fusion systems, i.e., two coiled-coil domains in Rz, a proline-rich region of Rz1, and flexible linkers in both proteins. When coding sequences are aligned respective to the embedded genetic architecture of Rz1 within Rz, genetically silent domains of Rz1 correspond to mutationally sensitive domains in Rz, and vice versa, suggesting that the modular structure of the two subunits facilitated the evolutionary compression that resulted in the unique embedded gene architecture. PMID:28040784

  18. DM/DE revealed: The physical origin of Lambda-CDM

    NASA Astrophysics Data System (ADS)

    Beichler, James

    2009-10-01

    In the past few decades two new `crises' affecting fundamental physics have emerged in the observation of phenomena that indicate the existence of Dark Matter and Dark Energy. These are not problems which can be solved by quantum theory or particles, but rather problems that are related to gravity theory as expressed by the general theory of relativity. Numerous ideas and hypotheses have been suggested to explain these new problematic phenomena, but no particular hypothesis or resulting model has proven satisfactory. No model yet proposed seems to be able to explain either DM and DE or both even though theoretical physicists generally agree that the two should have a single common explanation. There is, however, one relatively unknown exception that can explain both DM and DE without any additional hypotheses and this model explains the physical origins of the Lambda-CDM term that others have already proposed adding to general relativity. Yet this new model is not without consequences for the rest of physics and science: Accepting this new model would mean acknowledging the existence of a higher space-like dimension in addition to our normal four-dimensions of space-time.

  19. L-moments and TL-moments of the generalized lambda distribution

    USGS Publications Warehouse

    Asquith, W.H.

    2007-01-01

    The 4-parameter generalized lambda distribution (GLD) is a flexible distribution capable of mimicking the shapes of many distributions and data samples including those with heavy tails. The method of L-moments and the recently developed method of trimmed L-moments (TL-moments) are attractive techniques for parameter estimation for heavy-tailed distributions for which the L- and TL-moments have been defined. Analytical solutions for the first five L- and TL-moments in terms of GLD parameters are derived. Unfortunately, numerical methods are needed to compute the parameters from the L- or TL-moments. Algorithms are suggested for parameter estimation. Application of the GLD using both L- and TL-moment parameter estimates from example data is demonstrated, and comparison of the L-moment fit of the 4-parameter kappa distribution is made. A small simulation study of the 98th percentile (far-right tail) is conducted for a heavy-tail GLD with high-outlier contamination. The simulations show, with respect to estimation of the 98th-percent quantile, that TL-moments are less biased (more robost) in the presence of high-outlier contamination. However, the robustness comes at the expense of considerably more sampling variability. ?? 2006 Elsevier B.V. All rights reserved.

  20. Dengue virus infection induces interferon-lambda1 to facilitate cell migration

    PubMed Central

    Hsu, Yu-Lin; Wang, Mei-Yi; Ho, Ling-Jun; Lai, Jenn-Haung

    2016-01-01

    A marked increase in the rate of dengue virus (DENV) infection has resulted in more than 212 deaths in Taiwan since the beginning of 2015, mostly from fatal outcomes such as dengue hemorrhagic fever and dengue shock syndrome. The pathogenic mechanisms of these fatal manifestations are poorly understood. Cytokines induce an overwhelming immune reaction and thus have crucial roles. Interferon-lambda (IFN-λ), a newly identified IFN subtype, has antiviral effects, but its immunologic effects in DENV infection have not been investigated. In the present study, we show that DENV infection preferentially induced production of IFN-λ1 in human dendritic cells (DCs) and human lung epithelial cells. Virus nonstructural 1 (NS1) glycoprotein was responsible for the effect. DENV-induced production of IFN-λ1 was dependent on signaling pathways involving toll-like receptor (TLR)-3, interferon regulation factor (IRF)-3, and nuclear factor-kappaB (NF-κB). Blocking interaction between IFN-λ1 and its receptor IFN-λR1 through siRNA interference reduced DENV-induced DC migration towards the chemoattractants CCL19 and CCL21, by inhibiting CCR7 expression. Furthermore, IFN-λ1 itself induced CCR7 expression and DC migration. Our study presents the first evidence of the mechanisms and effects of IFN-λ1 induction in DENV-infected DCs and highlights the role of this cytokine in the immunopathogenesis of DENV infection. PMID:27456172

  1. Comparison of antiviral activity of lambda-interferons against HIV replication in macrophages.

    PubMed

    Wang, Yizhong; Li, Jieliang; Wang, Xu; Zhou, Yu; Zhang, Ting; Ho, Wenzhe

    2015-03-01

    Lambda-interferons (IFN-λs) have been demonstrated as having the ability to inhibit HIV replication in macrophages. However, specific differences in signaling transduction and anti-HIV activity in macrophages between different IFN-λs are unclear. Here, we showed that although all 3 members of (IFN-λ1, λ2, and λ3) IFN-λ family induced the expression of a number of genes of janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway in monocyte-derived macrophages, IFN-λ1 or IFN-λ3 induced higher levels of antiviral IFN-stimulated genes (ISGs) expression than did IFN-λ2. In addition, IFN-λ1 or IFN-λ3 induced higher levels of several pattern recognition receptors (PPRs) than did IFN-λ2. Incubation of IFN-λs with HIV-infected macrophages showed that IFN-λ1 or IFN-λ3 is more potent in anti-HIV activity than IFN-λ2. We also showed that IFN-λ treatment before HIV infection was more potent in HIV inhibition than that after HIV infection. Further investigations showed that the inductions of ISGs and PPRs expression by IFN-λs were largely compromised by HIV infection. These findings provide further experimental evidence that IFN-λs have therapeutic potential in treatment of HIV infection.

  2. A collaborative network middleware project by Lambda Station, TeraPaths, and Phoebus

    SciTech Connect

    Bobyshev, A.; Bradley, S.; Crawford, M.; DeMar, P.; Katramatos, D.; Shroff, K.; Swany, M.; Yu, D.; /Brookhaven

    2010-01-01

    The TeraPaths, Lambda Station, and Phoebus projects, funded by the US Department of Energy, have successfully developed network middleware services that establish on-demand and manage true end-to-end, Quality-of-Service (QoS) aware, virtual network paths across multiple administrative network domains, select network paths and gracefully reroute traffic over these dynamic paths, and streamline traffic between packet and circuit networks using transparent gateways. These services improve network QoS and performance for applications, playing a critical role in the effective use of emerging dynamic circuit network services. They provide interfaces to applications, such as dCache SRM, translate network service requests into network device configurations, and coordinate with each other to setup up end-to-end network paths. The End Site Control Plane Subsystem (ESCPS) builds upon the success of the three projects by combining their individual capabilities into the next generation of network middleware. ESCPS addresses challenges such as cross-domain control plane signalling and interoperability, authentication and authorization in a Grid environment, topology discovery, and dynamic status tracking. The new network middleware will take full advantage of the perfSONAR monitoring infrastructure and the Inter-Domain Control plane efforts and will be deployed and fully vetted in the Large Hadron Collider data movement environment.

  3. The Escherichia coli RNA polymerase alpha subunit and transcriptional activation by bacteriophage lambda CII protein.

    PubMed

    Gabig, M; Obuchowski, M; Ciesielska, A; Latała, B; Wegrzyn, A; Thomas, M S; Wegrzyn, G

    1998-01-01

    Bacteriophage lambda is not able to lysogenise the Escherichia coli rpoA341 mutant. This mutation causes a single amino acid substitution Lys271Glu in the C-terminal domain of the RNA polymerase alpha subunit (alphaCTD). Our previous studies indicated that the impaired lysogenisation of the rpoA341 host is due to a defect in transcriptional activation by the phage CII protein and suggested a role for alphaCTD in this process. Here we used a series of truncation and point mutants in the rpoA gene placed on a plasmid to investigate the process of transcriptional activation by the cII gene product. Our results indicate that amino-acid residues 265, 268 and 271 in the a subunit may play an important role in the CII-mediated activation of the pE promoter (most probably residue 271) or may be involved in putative interactions between alphaCTD and an UP-like element near pE (most probably residues 265 and 268). Measurement of the activity of pE-lacZ, pI-lacZ and p(aQ)-lacZ fusions in the rpoA+ and rpoA341 hosts demonstrated that the mechanism of activation of these CII-dependent promoters may be in each case different.

  4. Hydrodynamic and electrophoretic fingerprinting in the pH, p[lambda] domain

    SciTech Connect

    Prescott, J.H.

    1992-01-01

    A new technique, hydrodynamic fingerprinting, is presented for the characterization and study of colloidal dispersions on the basis of their hydrodynamic behavior. In the hydrodynamic fingerprint the hydrodynamic size as measured by photon correlation spectroscopy is presented as a function of two colloidal state variables simultaneously. There is an acid-base variable, pH, and a conductivity variable, p[lambda]. Hydrodynamic fingerprinting is applied to four polymer latexes, two polystyrene latexes, one with a sulfate surface and one with a carboxyl surface, and two methyl maehacrylate-ethyl acrylate latexes, one of which contains 2% acrylic acid. It is shown that hydrodynamic fingerprinting can be used to study colloidal stability, expandable properties of colloids, time effects in colloidal solutions, and the surface chemistry of the colloid-solution interface. A combinatorial hydrodynamic-electrokinetic fingerprinting analysis of the acid copolymer latex is also presented. This approach can be used to gain insight into ambiguous electrokinetic behavior, and to study the surface charge characteristics of colloidal dispersions.

  5. Identification of human antibody fragment clones specific for tetanus toxoid in a bacteriophage. lambda. immunoexpression library

    SciTech Connect

    Mullinax, R.L.; Gross, E.A.; Amberg, J.R.; Hogrefe, H.H.; Kubitz, M.M.; Greener, A.; Alting-Mees, M.; Ardourel, D.; Short, J.M.; Sorge, J.A. ); Hay, B.N.; Shopes, B. )

    1990-10-01

    The authors have applied a molecular biology approach to the identification of human monoclonal antibodies. Human peripheral blood lymphocyte mRNA was converted to cDNA and a select subset was amplified by the polymerase chain reaction. These products, containing coding sequences for numerous immunoglobulin heavy- and {kappa} light-chain variable and constant region domains, were inserted into modified bacteriophase {lambda} expression vectors and introduced into Escherichia coli by infection to yield a combinatorial immunoexpression library. Clones with binding activity to tetanus toxoid were identified by filter hybridization with radiolabeled antigen and appeared at a frequency of 0.2{percent} in the library. These human antigen binding fragments, consisting of a heavy-chain fragment covalently linked to a light chain, displayed high affinity of binding to tetanus toxoid with equilibrium constants in the nanomolar range but did not cross-react with other proteins tested. They estimate that this human immunoexpression library contains 20,000 clones with high affinity and specificity to our chosen antigen.

  6. Steplike Intensity Threshold Behavior of Extreme Ionization in Laser-Driven Xenon Clusters

    SciTech Connect

    Doeppner, T.; Mueller, J. P.; Przystawik, A.; Goede, S.; Tiggesbaeumker, J.; Meiwes-Broer, K.-H.; Varin, C.; Ramunno, L.; Brabec, T.; Fennel, T.

    2010-07-30

    The generation of highly charged Xe{sup q+} ions up to q=24 is observed in Xe clusters embedded in helium nanodroplets and exposed to intense femtosecond laser pulses ({lambda}=800 nm). Laser intensity resolved measurements show that the high-q ion generation starts at an unexpectedly low threshold intensity of about 10{sup 14} W/cm{sup 2}. Above threshold, the Xe ion charge spectrum saturates quickly and changes only weakly for higher laser intensities. Good agreement between these observations and a molecular dynamics analysis allows us to identify the mechanisms responsible for the highly charged ion production and the surprising intensity threshold behavior of the ionization process.

  7. Photoionization of molecular clusters

    NASA Astrophysics Data System (ADS)

    Andres, R. P.; Calo, J. M.

    1981-12-01

    An experimental apparatus consisting of a novel multiple expansion cluster source coupled with a molecular beam system and photoionization mass spectrometer has been designed and constructed. This apparatus has been thoroughly tested and preliminary measurements of the growth kinetics of water clusters and the photoionization cross section of the water dimer have been carried out.

  8. Probability and Cancer Clusters

    ERIC Educational Resources Information Center

    Hamilton-Keene, Rachael; Lenard, Christoper T.; Mills, Terry M.

    2009-01-01

    Recently there have been several news items about possible cancer clusters in the Australian media. The term "cancer cluster" is used when an unusually large number of people in one geographic area, often a workplace, are diagnosed with cancer in a short space of time. In this paper the authors explore this important health issue using…

  9. Coma cluster of galaxies

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Atlas Image mosaic, covering 34' x 34' on the sky, of the Coma cluster, aka Abell 1656. This is a particularly rich cluster of individual galaxies (over 1000 members), most prominently the two giant ellipticals, NGC 4874 (right) and NGC 4889 (left). The remaining members are mostly smaller ellipticals, but spiral galaxies are also evident in the 2MASS image. The cluster is seen toward the constellation Coma Berenices, but is actually at a distance of about 100 Mpc (330 million light years, or a redshift of 0.023) from us. At this distance, the cluster is in what is known as the 'Hubble flow,' or the overall expansion of the Universe. As such, astronomers can measure the Hubble Constant, or the universal expansion rate, based on the distance to this cluster. Large, rich clusters, such as Coma, allow astronomers to measure the 'missing mass,' i.e., the matter in the cluster that we cannot see, since it gravitationally influences the motions of the member galaxies within the cluster. The near-infrared maps the overall luminous mass content of the member galaxies, since the light at these wavelengths is dominated by the more numerous older stellar populations. Galaxies, as seen by 2MASS, look fairly smooth and homogeneous, as can be seen from the Hubble 'tuning fork' diagram of near-infrared galaxy morphology. Image mosaic by S. Van Dyk (IPAC).

  10. Mixed-Initiative Clustering

    ERIC Educational Resources Information Center

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  11. Cluster Guide. Accounting Occupations.

    ERIC Educational Resources Information Center

    Beaverton School District 48, OR.

    Based on a recent task inventory of key occupations in the accounting cluster taken in the Portland, Oregon, area, this curriculum guide is intended to assist administrators and teachers in the design and implementation of high school accounting cluster programs. The guide is divided into four major sections: program organization and…

  12. Marketing Occupations. Cluster Guide.

    ERIC Educational Resources Information Center

    Oregon State Dept. of Education, Salem.

    This cluster guide, which is designed to show teachers what specific knowledge and skills qualify high school students for entry-level employment (or postsecondary training) in marketing occupations, is organized into three sections: (1) cluster organization and implementation, (2) instructional emphasis areas, and (3) assessment. The first…

  13. Ultrametric Hierarchical Clustering Algorithms.

    ERIC Educational Resources Information Center

    Milligan, Glenn W.

    1979-01-01

    Johnson has shown that the single linkage and complete linkage hierarchical clustering algorithms induce a metric on the data known as the ultrametric. Johnson's proof is extended to four other common clustering algorithms. Two additional methods also produce hierarchical structures which can violate the ultrametric inequality. (Author/CTM)

  14. [Cluster headache differential diagnosis].

    PubMed

    Guégan-Massardier, Evelyne; Laubier, Cécile

    2015-11-01

    Cluster headache is characterized by disabling stereotyped headache. Early diagnosis allows appropriate treatment, unfortunately diagnostic errors are frequent. The main differential diagnoses are other primary or essential headaches. Migraine, more frequent and whose diagnosis is carried by excess, trigeminal neuralgia or other trigemino-autonomic cephalgia. Vascular or tumoral underlying condition can mimic cluster headache, neck and brain imaging is recommended, ideally MRI.

  15. Targeting Clusters, Achieving Excellence.

    ERIC Educational Resources Information Center

    Rosenfeld, Stuart; Jacobs, Jim; Liston, Cynthia

    2003-01-01

    Suggests that groups, or clusters, of industries form partnerships with community colleges in order to positively impact economic development. Asserts that a cluster-oriented community college system requires innovation, specialized resources and expertise, knowledge of trends, and links to industry. Offers suggestions for developing such a…

  16. Multiple frame cluster tracking

    NASA Astrophysics Data System (ADS)

    Gadaleta, Sabino; Klusman, Mike; Poore, Aubrey; Slocumb, Benjamin J.

    2002-08-01

    Tracking large number of closely spaced objects is a challenging problem for any tracking system. In missile defense systems, countermeasures in the form of debris, chaff, spent fuel, and balloons can overwhelm tracking systems that track only individual objects. Thus, tracking these groups or clusters of objects followed by transitions to individual object tracking (if and when individual objects separate from the groups) is a necessary capability for a robust and real-time tracking system. The objectives of this paper are to describe the group tracking problem in the context of multiple frame target tracking and to formulate a general assignment problem for the multiple frame cluster/group tracking problem. The proposed approach forms multiple clustering hypotheses on each frame of data and base individual frame clustering decisions on the information from multiple frames of data in much the same way that MFA or MHT work for individual object tracking. The formulation of the assignment problem for resolved object tracking and candidate clustering methods for use in multiple frame cluster tracking are briefly reviewed. Then, three different formulations are presented for the combination of multiple clustering hypotheses on each frame of data and the multiple frame assignments of clusters between frames.

  17. Brightest Cluster Galaxy Identification

    NASA Astrophysics Data System (ADS)

    Leisman, Luke; Haarsma, D. B.; Sebald, D. A.; ACCEPT Team

    2011-01-01

    Brightest cluster galaxies (BCGs) play an important role in several fields of astronomical research. The literature includes many different methods and criteria for identifying the BCG in the cluster, such as choosing the brightest galaxy, the galaxy nearest the X-ray peak, or the galaxy with the most extended profile. Here we examine a sample of 75 clusters from the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT) and the Sloan Digital Sky Survey (SDSS), measuring masked magnitudes and profiles for BCG candidates in each cluster. We first identified galaxies by hand; in 15% of clusters at least one team member selected a different galaxy than the others.We also applied 6 other identification methods to the ACCEPT sample; in 30% of clusters at least one of these methods selected a different galaxy than the other methods. We then developed an algorithm that weighs brightness, profile, and proximity to the X-ray peak and centroid. This algorithm incorporates the advantages of by-hand identification (weighing multiple properties) and automated selection (repeatable and consistent). The BCG population chosen by the algorithm is more uniform in its properties than populations selected by other methods, particularly in the relation between absolute magnitude (a proxy for galaxy mass) and average gas temperature (a proxy for cluster mass). This work supported by a Barry M. Goldwater Scholarship and a Sid Jansma Summer Research Fellowship.

  18. Hybridization schemes for clusters

    NASA Astrophysics Data System (ADS)

    Wales, David J.

    The concept of an optimum hybridization scheme for cluster compounds is developed with particular reference to electron counting. The prediction of electron counts for clusters and the interpretation of the bonding is shown to depend critically upon the presumed hybridization pattern of the cluster vertex atoms. This fact has not been properly appreciated in previous work, particularly in applications of Stone's tensor surface harmonic (TSH) theory, but is found to be a useful tool when dealt with directly. A quantitative definition is suggested for the optimum cluster hybridization pattern based directly upon the ease of interpretation of the molecular orbitals, and results are given for a range of species. The relationship of this scheme to the detailed cluster geometry is described using Löwdin's partitioned perturbation theory, and the success and range of application of TSH theory are discussed.

  19. Cool Cluster Correctly Correlated

    SciTech Connect

    Varganov, Sergey Aleksandrovich

    2005-01-01

    Atomic clusters are unique objects, which occupy an intermediate position between atoms and condensed matter systems. For a long time it was thought that physical and chemical properties of atomic dusters monotonically change with increasing size of the cluster from a single atom to a condensed matter system. However, recently it has become clear that many properties of atomic clusters can change drastically with the size of the clusters. Because physical and chemical properties of clusters can be adjusted simply by changing the cluster's size, different applications of atomic clusters were proposed. One example is the catalytic activity of clusters of specific sizes in different chemical reactions. Another example is a potential application of atomic clusters in microelectronics, where their band gaps can be adjusted by simply changing cluster sizes. In recent years significant advances in experimental techniques allow one to synthesize and study atomic clusters of specified sizes. However, the interpretation of the results is often difficult. The theoretical methods are frequently used to help in interpretation of complex experimental data. Most of the theoretical approaches have been based on empirical or semiempirical methods. These methods allow one to study large and small dusters using the same approximations. However, since empirical and semiempirical methods rely on simple models with many parameters, it is often difficult to estimate the quantitative and even qualitative accuracy of the results. On the other hand, because of significant advances in quantum chemical methods and computer capabilities, it is now possible to do high quality ab-initio calculations not only on systems of few atoms but on clusters of practical interest as well. In addition to accurate results for specific clusters, such methods can be used for benchmarking of different empirical and semiempirical approaches. The atomic clusters studied in this work contain from a few atoms to

  20. Effects of tidal gravitational fields in clustering dark energy models

    NASA Astrophysics Data System (ADS)

    Pace, Francesco; Reischke, Robert; Meyer, Sven; Schäfer, Björn Malte

    2017-04-01

    We extend a previous work by Reischke et al. by studying the effects of tidal shear on clustering dark energy models within the framework of the extended spherical collapse model and using the Zel'dovich approximation. As in previous works on clustering dark energy, we assumed a vanishing effective sound speed describing the perturbations in dark energy models. To be self-consistent, our treatment is valid only on linear scales since we do not intend to introduce any heuristic models. This approach makes the linear overdensity δc mass dependent and similarly to the case of smooth dark energy, its effects are predominant at small masses and redshifts. Tidal shear has effects of the order of per cent or less, regardless of the model and preserves a well-known feature of clustering dark energy: When dark energy perturbations are included, the models resemble better the Lambda cold dark matter evolution of perturbations. We also showed that effects on the comoving number density of haloes are small and qualitatively and quantitatively in agreement with what were previously found for smooth dark energy models.

  1. Galaxy cluster's rotation

    NASA Astrophysics Data System (ADS)

    Manolopoulou, M.; Plionis, M.

    2017-03-01

    We study the possible rotation of cluster galaxies, developing, testing, and applying a novel algorithm which identifies rotation, if such does exist, as well as its rotational centre, its axis orientation, rotational velocity amplitude, and, finally, the clockwise or counterclockwise direction of rotation on the plane of the sky. To validate our algorithms we construct realistic Monte Carlo mock rotating clusters and confirm that our method provides robust indications of rotation. We then apply our methodology on a sample of Abell clusters with z ≲ 0.1 with member galaxies selected from the Sloan Digital Sky Survey DR10 spectroscopic data base. After excluding a number of substructured clusters, which could provide erroneous indications of rotation, and taking into account the expected fraction of misidentified coherent substructure velocities for rotation, provided by our Monte Carlo simulation analysis, we find that ∼23 per cent of our clusters are rotating under a set of strict criteria. Loosening the strictness of the criteria, on the expense of introducing spurious rotation indications, we find this fraction increasing to ∼28 per cent. We correlate our rotation indicators with the cluster dynamical state, provided either by their Bautz-Morgan type or by their X-ray isophotal shape and find for those clusters showing rotation within 1.5 h^{-1}_{70} Mpc that the significance of their rotation is related to the dynamically younger phases of cluster formation but after the initial anisotropic accretion and merging has been completed. Finally, finding rotational modes in galaxy clusters could lead to the necessity of correcting the dynamical cluster mass calculations.

  2. Quantum-state storage and processing for polarization qubits in an inhomogeneously broadened {Lambda}-type three-level medium

    SciTech Connect

    Viscor, D.; Ferraro, A.; Mompart, J.; Ahufinger, V.; Loiko, Yu.

    2011-10-15

    We address the propagation of a single-photon pulse with two polarization components, i.e., a polarization qubit, in an inhomogeneously broadened ''phaseonium''{Lambda}-type three-level medium. We combine some of the nontrivial propagation effects characteristic for this kind of coherently prepared systems and the controlled reversible inhomogeneous broadening technique to propose several quantum information-processing applications, such as a protocol for polarization qubit filtering and sieving as well as a tunable polarization beam splitter. Moreover, we show that by imposing a spatial variation of the atomic coherence phase, an efficient quantum memory for the incident polarization qubit can be also implemented in {Lambda}-type three-level systems.

  3. Differences in potential for amino acid change after mutation reveals distinct strategies for kappa and lambda light-chain variation.

    PubMed

    Hershberg, Uri; Shlomchik, Mark J

    2006-10-24

    B cells generate varied yet functional clones under high rates of mutation of their V genes. It has been proposed that as a result of the opposing demands of diversification and preservation of integrity, the V genes of heavy and light chains have evolved to overexpress codons prone to amino acid change in their complementarity determining regions (CDR) compared with the framework (FW) regions. We have analyzed the germ-line V genes of heavy and light chains (both kappa and lambda), comparing codons of CDR and FW of the germ-line V regions both to each other and to control regions. We found that in both germ-line heavy chains and lambda chains, CDR codons are prone to replacement mutations, whereas in the FW, the opposite is true. Furthermore, the difference between CDR and FW in heavy chains and lambda chains is based on codons that are prone to nonconservative changes of amino acid. In contrast, in germ-line kappa chains, the codons in both CDR and FW are more prone to replacement mutations. We also demonstrated that negative selection during immune responses is more sensitive to nonconservative amino acid substitutions than overall amino acid change, demonstrating the applicability of our analysis to real-time process of selection in the immune system. The differences in germ-line kappa and lambda light chains' potential reaction to mutation suggests that via these two differently evolved light-chain types, the B cell repertoire encompasses two different strategies to balance diversity and stability in an immune response.

  4. Quasifree Lambda, Sigma^0, and Sigma^- electroproduction from 1,2H, 3,4He, and Carbon

    SciTech Connect

    F. Dohrmann; A. Ahmidouch; C.S. Armstrong; J. Arrington; R. Asaturyan; S. Avery; K. Bailey; H. Bitao; H. Breuer; D.S. Brown; R. Carlini; J. Cha; N. Chant; E. Christy; A. Cochran; L. Cole; J. Crowder; S. Danagoulian; M. Elaasar; R. Ent; H. Fenker; Y. Fujii; L. Gan; K. Garrow; D.F. Geesaman; P. Gueye; K. Hafidi; W. Hinton; H. Juengst; C. Keppel; Y. Liang; J.H. Liu; A. Lung; D. Mack; P. Markowitz; J. Mitchell; T. Miyoshi; H. Mkrtchyan; S.K. Mtingwa; B. Mueller; G. Niculescu; I. Niculescu; D. Potterveld; B.A. Raue; P.E. Reimer; J. Reinhold; J. Roche; M. Sarsour; Y. Sato; R.E. Segel; A. Semenov; S. Stepanyan; V. Tadevosyan; S. Tajima; L. Tang; A. Uzzle; S. Wood; H. Yamaguchi; C. Yan; L. Yuan; B. Zeidman; M. Zeier; B. Zihlmann

    2007-07-30

    Kaon electroproduction from light nuclei and hydrogen, using 1H, 2H, 3He, 4He, and Carbon targets has been measured at Jefferson Laboratory. The quasifree angular distributions of Lambda and Sigma hyperons were determined at Q^2= 0.35(GeV/c)^2 and W= 1.91GeV. Electroproduction on hydrogen was measured at the same kinematics for reference.

  5. Production of protons and LAMBDA's in e/sup +/e/sup -/ jets from jet calculus and the recombination model

    SciTech Connect

    Migneron, R.; Jones, L.M.; Lassila, K.E.

    1982-11-01

    We compute the expected yields of protons and LAMBDA's in e/sup +/e/sup -/ annihilation, using the Konishi-Ukawa-Veneziano jet calculus and the recombination model. Our results have many features in common with the data, including their approximate size. We derive a differential equation for baryon production, and show that the terms we have calculated are one of three physically different contributions.

  6. Characterization of the 2',3' cyclic phosphodiesterase activities of Clostridium thermocellum polynucleotide kinase-phosphatase and bacteriophage lambda phosphatase.

    PubMed

    Keppetipola, Niroshika; Shuman, Stewart

    2007-01-01

    Clostridium thermocellum polynucleotide kinase-phosphatase (CthPnkp) catalyzes 5' and 3' end-healing reactions that prepare broken RNA termini for sealing by RNA ligase. The central phosphatase domain of CthPnkp belongs to the dinuclear metallophosphoesterase superfamily exemplified by bacteriophage lambda phosphatase (lambda-Pase). CthPnkp is a Ni(2+)/Mn(2+)-dependent phosphodiesterase-monoesterase, active on nucleotide and non-nucleotide substrates, that can be transformed toward narrower metal and substrate specificities via mutations of the active site. Here we characterize the Mn(2+)-dependent 2',3' cyclic nucleotide phosphodiesterase activity of CthPnkp, the reaction most relevant to RNA repair pathways. We find that CthPnkp prefers a 2',3' cyclic phosphate to a 3',5' cyclic phosphate. A single H189D mutation imposes strict specificity for a 2',3' cyclic phosphate, which is cleaved to form a single 2'-NMP product. Analysis of the cyclic phosphodiesterase activities of mutated CthPnkp enzymes illuminates the active site and the structural features that affect substrate affinity and k(cat). We also characterize a previously unrecognized phosphodiesterase activity of lambda-Pase, which catalyzes hydrolysis of bis-p-nitrophenyl phosphate. lambda-Pase also has cyclic phosphodiesterase activity with nucleoside 2',3' cyclic phosphates, which it hydrolyzes to yield a mixture of 2'-NMP and 3'-NMP products. We discuss our results in light of available structural and functional data for other phosphodiesterase members of the binuclear metallophosphoesterase family and draw inferences about how differences in active site composition influence catalytic repertoire.

  7. Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture

    DOEpatents

    Sanfilippo, Antonio; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2009-12-22

    Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture are described. In one aspect, a document clustering method includes providing a document set comprising a plurality of documents, providing a cluster comprising a subset