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293 results on '"Lockhart, M."'

1. A 2 km-size asteroid challenging the rubble-pile spin barrier - a case for cohesion

Author

Polishook, D., Moskovitz, N., Binzel, R. P., Burt, B., DeMeo, F. E., Hinkle, M. L., Lockhart, M., Mommert, M., Person, M., Thirouin, A., Thomas, C. A., Trilling, D., Willman, M., and Aharonson, O.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The rubble pile spin barrier is an upper limit on the rotation rate of asteroids larger than ~200-300 m. Among thousands of asteroids with diameters larger than ~300 m, only a handful of asteroids are known to rotate faster than 2.0 h, all are in the sub-km range (<=0.6 km). Here we present photometric measurements suggesting that (60716) 2000 GD65, an S-complex, inner-main belt asteroid with a relatively large diameter of 2.3 +0.6-0.7 km, completes one rotation in 1.9529+-0.0002 h. Its unique diameter and rotation period allow us to examine scenarios about asteroid internal structure and evolution: a rubble pile bound only by gravity; a rubble-pile with strong cohesion; a monolithic structure; an asteroid experiencing mass shedding; an asteroid experiencing YORP spin-up/down; and an asteroid with a unique octahedron shape results with a four-peak lightcurve and a 3.9 h period. We find that the most likely scenario includes a lunar-like cohesion that can prevent (60716) 2000 GD65 from disrupting without requiring a monolithic structure or a unique shape. Due to the uniqueness of (60716) 2000 GD65, we suggest that most asteroids typically have smaller cohesion than that of lunar regolith., Comment: 16 pages, 8 figures, 3 tables

Published
2015
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2. Concept and optical design of the cross-disperser module for CRIRES+

Author

Oliva, E., Tozzi, A., Ferruzzi, D., Origlia, L., Hatzes, A., Follert, R., Loewinger, T., Piskunov, N., Heiter, U., Lockhart, M., Marquart, T., Stempels, E., Reiners, A., Anglada-Escude, G., Seemann, U., Dorn, R. J., Bristow, P., Baade, D., Delabre, B., Gojak, D., Grunhut, J., Klein, B., Hilker, M., Ives, D. J., Jung, Y., Kaeufl, H. U., Kerber, F., Lizon, J. L., Pasquini, L., Paufique, J., Pozna, E., Smette, A., Smoker, J., and Valenti, E.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

CRIRES, the ESO high resolution infrared spectrometer, is a unique instrument which allows astronomers to access a parameter space which up to now was largely uncharted. In its current setup, it consists of a single-order spectrograph providing long-slit, single-order spectroscopy with resolving power up to R=100,000 over a quite narrow spectral range. This has resulted in sub-optimal efficiency and use of telescope time for all the scientific programs requiring broad spectral coverage of compact objects (e.g. chemical abundances of stars and intergalactic medium, search and characterization of extra-solar planets). To overcome these limitations, a consortium was set-up for upgrading CRIRES to a cross-dispersed spectrometer, called CRIRES+. This paper presents the updated optical design of the crossdispersion module for CRIRES+. This new module can be mounted in place of the current pre-disperser unit. The new system yields a factor of >10 increase in simultaneous spectral coverage and maintains a quite long slit (10"), ideal for observations of extended sources and for precise sky-background subtraction., Comment: 14 pages, 9 figures, 22 tables. Presented at SPIE Astronomical Telescope + Instrumentation 2014 (Ground-based and Airbone Instrumentation for Astronomy 5, 9147-289). To be published in Proceeding of SPIE Volume 9147

Published
2014
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3. Multiple and Fast: The Accretion of Ordinary Chondrite Parent Bodies

Author

Vernazza, P., Zanda, B., Binzel, R. P., Hiroi, T., DeMeo, F. E., Birlan, M., Hewins, R., Ricci, L., Barge, P., and Lockhart, M.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Although petrologic, chemical and isotopic studies of ordinary chondrites and meteorites in general have largely helped establish a chronology of the earliest events of planetesimal formation and their evolution, there are several questions that cannot be resolved via laboratory measurements and/or experiments only. Here we propose rationale for several new constraints on the formation and evolution of ordinary chondrite parent bodies (and by extension most planetesimals) from newly available spectral measurements and mineralogical analysis of main belt S-type asteroids (83 objects) and unequilibrated ordinary chondrite meteorites (53 samples). Based on the latter, we suggest spectral data may be used to distinguish whether an ordinary chondrite was formed near the surface or in the interior of its parent body. If these constraints are correct, the suggested implications include that: i) large groups of compositionally similar asteroids are a natural outcome of planetesimal formation and, consequently, meteorites within a given class can originate from multiple parent bodies; ii) the surfaces of large (up to ~200km) S-type main-belt asteroids expose mostly the interiors of the primordial bodies, a likely consequence of impacts by small asteroids (D<10km) in the early solar system (Ciesla et al. 2013); iii) the duration of accretion of the H chondrite parent bodies was likely short (instantaneous or in less then ~10^5 yr but certainly not as long as 1 Myr); iv) LL-like bodies formed closer to the Sun than H-like bodies, a possible consequence of radial mixing and size sorting of chondrules in the protoplanetary disk prior to accretion., Comment: Accepted for publication in ApJ

Published
2014
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4. Spectral and Spin Measurement of Two Small and Fast-Rotating Near-Earth Asteroids

Author

Polishook, D., Binzel, R. P., Lockhart, M., DeMeo, F. E., Golisch, W., Bus, S. J., and Gulbis, A. A. S.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

In May 2012 two asteroids made near-miss "grazing" passes at distances of a few Earth-radii: 2012 KP24 passed at nine Earth-radii and 2012 KT42 at only three Earth-radii. The latter passed inside the orbital distance of geosynchronous satellites. From spectral and imaging measurements using NASA's 3-m Infrared Telescope Facility (IRTF), we deduce taxonomic, rotational, and physical properties. Their spectral characteristics are somewhat atypical among near-Earth asteroids: C-complex for 2012 KP24 and B-type for 2012 KT42, from which we interpret the albedos of both asteroids to be between 0.10 and 0.15 and effective diameters of 20+-2 and 6+-1 meters, respectively. Among B-type asteroids, the spectrum of 2012 KT42 is most similar to 3200 Phaethon and 4015 Wilson-Harrington. Not only are these among the smallest asteroids spectrally measured, we also find they are among the fastest-spinning: 2012 KP24 completes a rotation in 2.5008+-0.0006 minutes and 2012 KT42 rotates in 3.634+-0.001 minutes., Comment: 4 pages, 3 figures, accepted for publication in Icarus

Published
2012
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5. Ground-based multisite observations of two transits of HD 80606b

Author

Shporer, A., Winn, J. N., Dreizler, S., Colon, K. D., Wood-Vasey, W. M., Choi, P. I., Morley, C., Moutou, C., Welsh, W. F., Pollaco, D., Starkey, D., Adams, E., Barros, S. C. C., Bouchy, F., Cabrera-Lavers, A., Cerutti, S., Coban, L., Costello, K., Deeg, H., Diaz, R. F., Esquerdo, G. A., Fernandez, J., Fleming, S. W., Ford, E. B., Fulton, B. J., Good, M., Hebrard, G., Holman, M. J., Hunt, M., Kadakia, S., Lander, G., Lockhart, M., Mazeh, T., Morehead, R. C., Nelson, B. E., Nortmann, L., Reyes, F., Roebuck, E., Rudy, A. R., Ruth, R., Simpson, E., Vincent, C., Weaver, G., and Xie, J. -W.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present ground-based optical observations of the September 2009 and January 2010 transits of HD 80606b. Based on 3 partial light curves of the September 2009 event, we derive a midtransit time of T_c [HJD] = 2455099.196 +- 0.026, which is about 1 sigma away from the previously predicted time. We observed the January 2010 event from 9 different locations, with most phases of the transit being observed by at least 3 different teams. We determine a midtransit time of T_c [HJD] = 2455210.6502 +- 0.0064, which is within 1.3 sigma of the time derived from a Spitzer observation of the same event., Comment: Accepted to ApJ. Comments are most welcome. v2: added acknowledgments

Published
2010
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7. Adeno-associated virus 2 infection in children with non-A-E hepatitis

Author

Ho, A, Orton, R, Tayler, R, Asamaphan, P, Herder, V, Davis, C, Tong, L, Smollett, K, Manali, M, Allan, J, Rawlik, K, McDonald, SE, Vink, E, Pollock, L, Gannon, L, Evans, C, McMenamin, J, Roy, K, Marsh, K, Divala, T, Holden, MTG, Lockhart, M, Yirrell, D, Currie, S, O'Leary, M, Henderson, D, Shepherd, SJ, Jackson, C, Gunson, R, MacLean, A, McInnes, N, Bradley-Stewart, A, Battle, R, Hollenbach, JA, Henderson, P, Odam, M, Chikowore, P, Oosthuyzen, W, Chand, M, Hamilton, MS, Estrada-Rivadeneyra, D, Levin, M, Avramidis, N, Pairo-Castineira, E, Vitart, V, Wilkie, C, Palmarini, M, Ray, S, Wilkinson, J, Consortium, DIAMONDS, and Investigators, ISARIC4C

Abstract

An outbreak of acute hepatitis of unknown aetiology in children was reported in Scotland1 in April 2022 and has now been identified in 35 countries2. Several recent studies have suggested an association with human adenovirus with this outbreak, a virus not commonly associated with hepatitis. Here we report a detailed case-control investigation and find an association between adeno-associated virus 2 (AAV2) infection and host genetics in disease susceptibility. Using next-generation sequencing, PCR with reverse transcription, serology and in situ hybridization, we detected recent infection with AAV2 in plasma and liver samples in 26 out of 32 (81%) cases of hepatitis compared with 5 out of 74 (7%) of samples from unaffected individuals. Furthermore, AAV2 was detected within ballooned hepatocytes alongside a prominent T cell infiltrate in liver biopsy samples. In keeping with a CD4+ T-cell-mediated immune pathology, the human leukocyte antigen (HLA) class II HLA-DRB1*04:01 allele was identified in 25 out of 27 cases (93%) compared with a background frequency of 10 out of 64 (16%; P = 5.49 × 10-12). In summary, we report an outbreak of acute paediatric hepatitis associated with AAV2 infection (most likely acquired as a co-infection with human adenovirus that is usually required as a 'helper virus' to support AAV2 replication) and disease susceptibility related to HLA class II status.

Published
2023

11. Adeno-associated virus 2 infection in children with non-A–E hepatitis

Author

Ho A, Orton R, Tayler R, Asamaphan P, herder V, Davis C, Tong L, Smollett K, Manali M, Allen J, Rawlik K, McDonald SE, Vink E, Pollock L, Gannon L, Evans C, McMenamin J, Roy K, Marsh K, Divala T, Holden MTG, Lockhart M, Yirrell D, Currie S, O'Leary M, Henderson D, Shepherd SJ, Jackson C, Gunson R, MacLean A, McInnes N, Bradley-Stewart A, Battle R, Hollenbach J, Henderson P, Odam M, Chikowore P, Oosthuyzen W, Chand M, Hamilton MS, Estrada-Rivadeneyra D, Levin M, Avramidis N, Pairo-Castineira E, Vitart V, Wilkie C, Ray S, Emonts,M, Bell,A, Bell,K, Fabian,D, Isaacs,J, Lim,E, Shenton,G, Treloar,O, Van Der Veldon,F, DIAMONDS Consortium, ISARIC4C Investigators

Published
2023
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16. A Phase 2a Randomized, Double-Blind, Dose-Optimizing Study to Evaluate the Immunogenicity and Safety of a Bivalent DNA Vaccine for Hemorrhagic Fever with Renal Syndrome Delivered by Intramuscular Electroporation

Author

Hooper, Jay, primary, Paolino, K. M., additional, Mills, K., additional, Kwilas, S., additional, Josleyn, M., additional, Cohen, M., additional, Somerville, B., additional, Wisniewski, M., additional, Norris, S., additional, Hill, B., additional, Sanchez-Lockhart, M., additional, Hannaman, D., additional, and Schmaljohn, C. S., additional

Published
2020
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17. 15: Outcomes of the defining mechanisms of anterior vaginal wall descent trial

Author

Bowen, S.T., primary, Moalli, P., additional, Abramowitch, S., additional, Lockhart, M., additional, Meyn, L., additional, Nager, C., additional, Visco, A.G., additional, Richter, H.E., additional, Rardin, C., additional, Komesu, Y., additional, Harvie, H.S., additional, Paraiso, M.R., additional, Mazloomdoost, D., additional, Sridhar, A., additional, Gantz, M.G., additional, and PFDN, F., additional

Published
2020
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19. Size and albedo of Kuiper belt object 55636 from a stellar occultation

Author

Elliot, J. L., Person, M. J., Zuluaga, C. A., Bosh, A. S., Adams, E. R., Brothers, T. C., Gulbis, A. A. S., Levine, S. E., Lockhart, M., Zangari, A. M., Babcock, B. A., DuPré, K., Pasachoff, J. M., Souza, S. P., Rosing, W., Secrest, N., Bright, L., Dunham, E. W., Sheppard, S. S., Kakkala, M., Tilleman, T., Berger, B., Briggs, J. W., Jacobson, G., Valleli, P., Volz, B., Rapoport, S., Hart, R., Brucker, M., Michel, R., Mattingly, A., Zambrano-Marin, L., Meyer, A. W., Wolf, J., Ryan, E. V., Ryan, W. H., Morzinski, K., Grigsby, B., Brimacombe, J., Ragozzine, D., Montano, H. G., and Gilmore, A.

Published
2010
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21. An integrated national scale SARS-CoV-2 genomic surveillance network

Author

Aanensen, DM, Abudahab, K, Adams, A, Afifi, S, Alam, MT, Alderton, A, Alikhan, N-F, Allan, J, Almsaud, M, Alrezaihi, A, Alruwaili, M, Amato, R, Andersson, M, Angyal, A, Aranday-Cortes, E, Ariani, C, Armstrong, SD, Asamaphan, P, Attwood, S, Aydin, A, Badhan, A, Baker, D, Baker, P, Balcazar, CE, Ball, J, Barton, AE, Bashton, M, Baxter, L, Beale, M, Beaver, C, Beckett, A, Beer, R, Beggs, A, Bell, A, Bellis, KL, Bentley, EG, Berriman, M, Betteridge, E, Bibby, D, Bicknell, K, Birchley, A, Black, G, Blane, B, Bloomfield, S, Bolt, F, Bonsall, DG, Bosworth, A, Bourgeois, Y, Boyd, O, Bradshaw, D, Breuer, J, Bridgewater, H, Brooks, T, Broos, A, Brown, JR, Brown, RL, Brunker, K, Bucca, G, Buck, D, Bull, M, Butcher, E, Caddy, SL, Caller, LG, Cambell, S, Carlile, M, Carmichael, S, Carrilero, L, Castellano, S, Chaloner, J, Chand, M, Chapman, MR, Chappell, J, Charles, I, Chauhan, AJ, Chawla, A, Cheng, E, Churcher, CM, Clark, G, Clark, JJ, Collins, J, Colquhoun, R, Connor, TR, Constantinidou, C, Coombes, J, Corden, S, Cottrell, S, Cowell, A, Curran, MD, Curran, T, Dabrera, G, Danesh, J, Darby, AC, De Cesare, M, Martins, LDO, De Silva, TI, Debebe, B, Dervisevic, S, Dewar, RA, Dia, M, Dorman, M, Dougan, G, Dover, L, Downing, F, Drury, E, Du Plessis, L, Dyal, PL, Eccles, R, Edwards, S, Ellaby, N, Elliott, S, Eltringham, G, Elumogo, N, Essex, S, Evans, CM, Evans, J, Nascimento, FF, Fairley, DJ, Farr, B, Feltwell, T, Ferguson, N, Filipe, ADS, Findlay, J, Forrest, LM, Forrest, S, Foulser, L, Francois, S, Fraser, C, Frost, L, Gallagher, E, Gallagher, MD, Garcia-Dorival, I, Gaskin, A, Gatica-Wilcox, B, Gavriil, A, Geidelberg, L, Gemmell, M, Gerada, A, Gifford, L, Gilbert, L, Gilmore, P, Gilroy, R, Girgis, S, Glaysher, S, Golubchik, T, Goncalves, S, Goodfellow, I, Goodwin, S, Graham, C, Graham, L, Grammatopoulos, D, Green, A, Green, LR, Greenaway, J, Gregory, R, Groves, DC, Groves, N, Guest, M, Gunson, R, Haldenby, S, Hall, G, Hamilton, WL, Han, X, Harris, KA, Harrison, EM, Hartley, C, Herrera, C, Hesketh, A, Heyburn, D, Hill, V, Hiscox, JA, Holden, M, Holmes, A, Holmes, N, Holt, GS, Hopes, R, Hosmillo, M, Houldcroft, CJ, Howson-Wells, H, Hubb, J, Hughe, J, Hughes, M, Hutchings, S, Impey, R, Iturriza-Gomara, M, Jackson, A, Jackson, B, Jackson, DK, Jahun, AS, James, K, Jamrozy, D, Jeffries, A, Jesudason, N, John, M, Johnson, J, Johnson, KJ, Johnson, N, Johnston, I, Jones, B, Jones, R, Jones, S, Jorgensen, D, Kane, L, Kay, GL, Kay, S, Keatley, J-P, Keeley, AJ, Khakh, M, Khokhar, FA, Kitchen, C, Knight, B, Kolyva, A, Kraemer, M, Kristiansen, M, Kumziene-Summerhayes, S, Kwiatkowski, D, Lackenby, A, Langford, C, Lawniczak, M, Thanh, L-V, Lee, D, Letchford, L, Li, K, Li, L, Liggett, S, Lindsey, BB, Livett, R, Lloyd, A, Lo, S, Lockhart, M, Loh, J, Loman, NJ, Loose, M, Lucaci, A, Ludden, C, Luu, L, Lyons, RA, MacIntyre-Cockett, G, MacLean, A, Mair, D, Maksimovic, J, Manley, R, Manso, C, Manson, J, Martincorena, I, Masoli, J, Mather, AE, Mbisa, T, McCluggage, K, McClure, P, McCrone, JT, McDonald, S, McHugh, MP, McKenna, JM, McMinn, L, McMurray, C, Meadows, L, Menegazzo, M, Meredith, LW, Merrick, I, Mestek-Boukhibar, L, Miah, S, Michell, S, Michelsen, ML, Molnar, Z, Moore, C, Moore, N, Morgan, M, Morgan, S, Muddyman, D, Muir, DA, Muir, P, Myers, R, Nastouli, E, Naydenova, P, Nelson, A, Nelson, C, Nelson, R, Nicholls, S, Nichols, J, Niebel, M, Niola, P, Nomikou, K, O'Grady, J, O'Toole, AN, O'Toole, E, Olateju, C, Orton, RJ, Osman, H, Ott, S, Pacchiarini, N, Padgett, D, Page, AJ, Palmer, S, Panchbhaya, YN, Pandey, S, Park, N, Parker, MD, Parkhill, J, Parr, YA, Parsons, PJ, Partridge, DG, Patel, M, Patterson, S, Payne, B, Peacock, SJ, Penrice-Randal, R, Perry, M, Platt, S, Poplawski, R, Prakash, R, Prestwood, L, Price, A, Price, JR, Puethe, C, Pybus, O, Pymont, H, Quail, M, Quick, J, Raghwani, J, Ragonnet-Cronin, M, Rahman, S, Rainbow, L, Rajatileka, S, Rambaut, A, Ramsay, M, Randell, PA, Randle, NP, Raviprakash, V, Raza, M, Silva, PR, Rey, S, Richter, A, Robertson, DL, Robinson, TI, Robson, SC, Rooke, S, Rowan, A, Rowe, W, Roy, S, Rudder, S, Ruis, C, Sang, F, Scarlett, G, Schaefer, U, Scott, C, Scott, G, Sethi, D, Shaaban, S, Shah, R, Sharma, P, Shawli, GT, Shepherd, J, Sherriff, N, Shirley, L, Sillitoe, J, Simpson, DA, Singer, JB, Siveroni, I, Smith, C, Smith, CP, Smith, DL, Smith, N, Smith, W, Smith-Palmer, A, Smollett, K, Southgate, J, Spellman, K, Spencer-Chapman, M, Sridhar, S, Stanley, R, Stark, R, Stewart, JP, Stockton, J, Stuart, C, Studholme, D, Swainston, N, Swindells, E, Taha, Y, Tariq, MA, Taylor, B, Taylor, GP, Taylor, S, Taylor-Joyce, G, Tedim, AP, Temperton, B, Templeton, KE, Thomson, EC, Thomson, NM, Thornton, A, Thurston, S, Todd, J, Tong, L, Tonkin-Hill, G, Torok, ME, Trebes, A, Trotter, AJ, Tsoleridis, T, Tucker, RM, Tutill, HJ, Underwood, A, Unnikrishnan, M, Vamos, E, Vasylyeva, T, Vattipally, S, Victoria, A, Vipond, B, Volz, EM, Wain, J, Wang, D, Warwick-Dugdale, J, Wastnedge, E, Watkins, J, Watts, J, Webber, M, Weeks, S, Weldon, D, Whitehead, M, Williams, CA, Williams, C, Williams, D, Williams, R, Williams, TC, Wise, E, Wright, V, Wyles, MD, Wyllie, S, Yakovleva, A, Yasir, M, Yeats, C, Yew, WC, Young, GR, Yu, X, and Zarebski, A

Subjects
Microbiology (medical), Scale (ratio), SARS-CoV-2, viruses, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), COVID-19, COVID-19 Genomics UK (COG-UK) consortiumcontact@cogconsortium.uk, C500, Genome, Viral, Genomics, Biology, C700, Microbiology, Article, Infectious Diseases, Virology, Humans, Cartography
Abstract

The Coronavirus Disease 2019 (COVID-19) Genomics UK Consortium (COG-UK) was launched in March, 2020, with £20 million support from UK Research and Innovation, the UK Department of Health and Social Care, and Wellcome Trust. The goal of this consortium is to sequence severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for up to 230 000 patients, health-care workers, and other essential workers in the UK with COVID-19, which will help to enable the tracking of SARS-CoV-2 transmission, identify viral mutations, and integrate with health data to assess how the viral genome interacts with cofactors and consequences of COVID-19.

Published
2020

23. A 2km-size asteroid challenging the rubble-pile spin barrier – A case for cohesion

Author

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Binzel, Richard P, Burt, Brian, DeMeo, Francesca E, Person, Michael J, Polishook, D., Moskovitz, N., Hinkle, M.L., Lockhart, M., Mommert, M., Thirouin, A., Thomas, C.A., Trilling, D., Willman, M., Aharonson, O., Person, Michael J., Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Binzel, Richard P, Burt, Brian, DeMeo, Francesca E, Person, Michael J, Polishook, D., Moskovitz, N., Hinkle, M.L., Lockhart, M., Mommert, M., Thirouin, A., Thomas, C.A., Trilling, D., Willman, M., Aharonson, O., and Person, Michael J.

Abstract

The rubble pile spin barrier is an upper limit on the rotation rate of asteroids larger than ~200-300. m. Among thousands of asteroids with diameters larger than ~300. m, only a handful of asteroids are known to rotate faster than 2.0. h, all are in the sub-km range (≤0.6. km). Here we present photometric measurements suggesting that (60716) 2000 GD65, an S-complex, inner-main belt asteroid with a relatively large diameter of 2.3-0.7+0.6km, completes one rotation in 1.9529. ±. 0.0002. h. Its unique diameter and rotation period allow us to examine scenarios about asteroid internal structure and evolution: a rubble pile bound only by gravity; a rubble-pile with strong cohesion; a monolithic structure; an asteroid experiencing mass shedding; an asteroid experiencing YORP spin-up/down; and an asteroid with a unique octahedron shape results with a four-peak lightcurve and a 3.9. h period. We find that the most likely scenario includes a lunar-like cohesion that can prevent (60716) 2000 GD65 from disrupting without requiring a monolithic structure or a unique shape. Due to the uniqueness of (60716) 2000 GD65, we suggest that most asteroids typically have smaller cohesion than that of lunar regolith. Keywords: Asteroids; Asteroids, rotation; Rotational dynamics; Photometry, United States. National Aeronautics and Space Administration (Grant NNX12AL26G)

Published
2018

24. Virus genomes reveal factors that spread and sustained the Ebola epidemic

Author

Dudas, G. (Gytis), Carvalho, L.M. (Luiz Max), Bedford, T. (Trevor), Tatem, A.J. (Andrew J.), Baele, G. (Guy), Faria, R. (Rui), Park, D.J. (Daniel J.), Ladner, J.T. (Jason T.), Arias, A., Asogun, D. (Danny), Bielejec, F. (Filip), Caddy, S.L., Cotten, M. (Matthew), D'Ambrozio, J. (Jonathan), Dellicour, S. (Simon), Di Caro, A. (Antonino), Diclaro, J.W. (Joseph W.), Duraffour, S. (Sophie), Elmore, M.J. (Michael J.), Fakoli, L.S. (Lawrence S.), Faye, O. (Ousmane), Gilbert, M.L. (Merle L.), Gevao, S.M. (Sahr M.), Gire, S. (Stephen), Gladden-Young, A. (Adrianne), Gnirke, A. (Andreas), Goba, A. (Augustine), Grant, D.S. (Donald S.), Haagmans, B.L. (Bart), Hiscox, J.A. (Julian A.), Jah, U., Kugelman, J.R. (Jeffrey R.), Liu, D. (Di), Lu, J. (Jia), Malboeuf, C.M. (Christine M.), Mate, S. (Suzanne), Matthews, D.A. (David A.), Matranga, C.B. (Christian B.), Meredith, L.W. (Luke W.), Qu, J. (James), Quick, J. (Joshua), Pas, S.D. (Suzan), Phan, M.V.T. (My V. T.), Pollakis, G. (G.), Reusken, C.B.E.M. (Chantal), Sanchez-Lockhart, M. (Mariano), Schaffner, S.F. (Stephen F.), Schieffelin, J.S. (John S.), Sealfon, R.S. (Rachel S.), Simon-Loriere, E. (Etienne), Smits, S.L. (Saskia), Stoecker, K. (Kilian), Thorne, L. (Lucy), Tobin, E.A. (Ekaete Alice), Vandi, M.A. (Mohamed A.), Watson, S.J. (Simon J.), West, K. (Kendra), Whitmer, S. (Shannon), Wiley, M.R. (Michael R.), Winnicki, S.M. (Sarah M.), Wohl, S. (Shirlee), Wölfel, R. (Roman), Yozwiak, N.L. (Nathan L.), Andersen, K.G. (Kristian G.), Blyden, S.O. (Sylvia O.), Bolay, F. (Fatorma), Carroll, M.W. (Miles W.), Dahn, B. (Bernice), Diallo, B. (Boubacar), Formenty, P. (Pierre), Fraser, C. (Christophe), Gao, G.F. (George F.), Garry, R.F. (Robert F.), Goodfellow, I. (Ian), Günther, S. (Stephan), Happi, C.T. (Christian T.), Holmes, E.C. (Edward C.), Kargbo, B. (Brima), Keïta, S. (Sakoba), Kellam, P. (Paul), Koopmans D.V.M., M.P.G. (Marion), Kuhn, J.H. (Jens H.), Loman, N.J. (Nicholas J.), Magassouba, N. (N'Faly), Naidoo, D. (Dhamari), Nichol, S.T. (Stuart T.), Nyenswah, T. (Tolbert), Palacios, G. (Gustavo), Pybus, O. (Oliver), Sabeti, P.C. (Pardis C.), Sall, A. (Amadou), Ströher, U. (Ute), Wurie, I., Suchard, M.A. (Marc), Lemey, P. (Philippe), Rambaut, A. (Andrew), Dudas, G. (Gytis), Carvalho, L.M. (Luiz Max), Bedford, T. (Trevor), Tatem, A.J. (Andrew J.), Baele, G. (Guy), Faria, R. (Rui), Park, D.J. (Daniel J.), Ladner, J.T. (Jason T.), Arias, A., Asogun, D. (Danny), Bielejec, F. (Filip), Caddy, S.L., Cotten, M. (Matthew), D'Ambrozio, J. (Jonathan), Dellicour, S. (Simon), Di Caro, A. (Antonino), Diclaro, J.W. (Joseph W.), Duraffour, S. (Sophie), Elmore, M.J. (Michael J.), Fakoli, L.S. (Lawrence S.), Faye, O. (Ousmane), Gilbert, M.L. (Merle L.), Gevao, S.M. (Sahr M.), Gire, S. (Stephen), Gladden-Young, A. (Adrianne), Gnirke, A. (Andreas), Goba, A. (Augustine), Grant, D.S. (Donald S.), Haagmans, B.L. (Bart), Hiscox, J.A. (Julian A.), Jah, U., Kugelman, J.R. (Jeffrey R.), Liu, D. (Di), Lu, J. (Jia), Malboeuf, C.M. (Christine M.), Mate, S. (Suzanne), Matthews, D.A. (David A.), Matranga, C.B. (Christian B.), Meredith, L.W. (Luke W.), Qu, J. (James), Quick, J. (Joshua), Pas, S.D. (Suzan), Phan, M.V.T. (My V. T.), Pollakis, G. (G.), Reusken, C.B.E.M. (Chantal), Sanchez-Lockhart, M. (Mariano), Schaffner, S.F. (Stephen F.), Schieffelin, J.S. (John S.), Sealfon, R.S. (Rachel S.), Simon-Loriere, E. (Etienne), Smits, S.L. (Saskia), Stoecker, K. (Kilian), Thorne, L. (Lucy), Tobin, E.A. (Ekaete Alice), Vandi, M.A. (Mohamed A.), Watson, S.J. (Simon J.), West, K. (Kendra), Whitmer, S. (Shannon), Wiley, M.R. (Michael R.), Winnicki, S.M. (Sarah M.), Wohl, S. (Shirlee), Wölfel, R. (Roman), Yozwiak, N.L. (Nathan L.), Andersen, K.G. (Kristian G.), Blyden, S.O. (Sylvia O.), Bolay, F. (Fatorma), Carroll, M.W. (Miles W.), Dahn, B. (Bernice), Diallo, B. (Boubacar), Formenty, P. (Pierre), Fraser, C. (Christophe), Gao, G.F. (George F.), Garry, R.F. (Robert F.), Goodfellow, I. (Ian), Günther, S. (Stephan), Happi, C.T. (Christian T.), Holmes, E.C. (Edward C.), Kargbo, B. (Brima), Keïta, S. (Sakoba), Kellam, P. (Paul), Koopmans D.V.M., M.P.G. (Marion), Kuhn, J.H. (Jens H.), Loman, N.J. (Nicholas J.), Magassouba, N. (N'Faly), Naidoo, D. (Dhamari), Nichol, S.T. (Stuart T.), Nyenswah, T. (Tolbert), Palacios, G. (Gustavo), Pybus, O. (Oliver), Sabeti, P.C. (Pardis C.), Sall, A. (Amadou), Ströher, U. (Ute), Wurie, I., Suchard, M.A. (Marc), Lemey, P. (Philippe), and Rambaut, A. (Andrew)

Abstract

The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations. Despite attenuation of international dispersal after border closures, cross-border transmission had already sown the seeds for an international epidemic, rendering these measures ineffective at curbing the epidemic. We address why the epidemic did not spread into neighbouring countries, showing that these countries were susceptible to substantial outbreaks but at lower risk of introductions. Finally, we reveal that this large epidemic was a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help to inform interventions in future epidemics.

Published
2017
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25. Virus genomes reveal the factors that spread and sustained the West African Ebola epidemic

Author

Dudas, G, Carvalho, LM, Bedford, T, Tatem, A, Baele, G, Faria, N, Park, D, Ladner, J, Arias, A, Asogun, D, Bielejec, F, Caddy, S, Cotten, M, Dambrozio, J, Dellicour, S, Di Caro, A, Diclaro, J, Duraffour, S, Elmore, M, Fakoli, L, Gilbert, M, Gevao, S, Gire, S, Gladden-Young, A, Gnirke, A, Goba, A, Grant, D, Haagmans, B, Hiscox, J, Jah, U, Kargbo, B, Kugelman, J, Liu, D, Lu, J, Malboeuf, C, Mate, S, Matthews, D, Matranga, C, Meredith, L, Qu, J, Quick, J, Pas, S, Phan, MVT, Poliakis, G, Reusken, C, Sanchez-Lockhart, M, Schaffner, S, Schieffelin, J, Sealfon, R, Simon-Loriere, E, Smits, S, Stoecker, K, Thorne, L, Tobin, E, Vandi, M, Watson, S, West, K, Whitmer, S, Wiley, M, Winnicki, S, Wohl, S, Wölfel, R, Yozwiak, N, Andersen, K, Blyden, S, Bolay, F, Carroll, M, Dahn, B, Diallo, B, Formenty, P, Fraser, C, Gao, G, Garry, R, Goodfellow, I, Günther, S, Happi, C, Holmes, E, Kellam, P, Koopmans, MPG, Loman, N, Magassouba, N, Naidoo, D, Nichol, S, Nyenswah, T, Palacios, G, Pybus, O, Sabeti, P, Sall, A, Sakoba, K, Ströeher, U, Wurie, I, Suchard, M, Lemey, P, Rambaut, A, and Wellcome Trust

Subjects
viruses
Abstract

Summary The 2013-2016 epidemic of Ebola virus disease in West Africa was of unprecedented magnitude, duration and impact. Extensive collaborative sequencing projects have produced a large collection of over 1600 Ebola virus genomes, representing over 5% of known cases, unmatched for any single human epidemic. In this comprehensive analysis of this entire dataset, we reconstruct in detail the history of migration, proliferation and decline of Ebola virus throughout the region. We test the association of geography, climate, administrative boundaries, demography and culture with viral movement among 56 administrative regions. Our results show that during the outbreak viral lineages moved according to a classic ‘gravity’ model, with more intense migration between larger and more proximate population centers. Notably, we find that despite a strong attenuation of international dispersal after border closures, localized cross-border transmission beforehand had already set the seeds for an international epidemic, rendering these measures relatively ineffective in curbing the epidemic. We use this empirical evidence to address why the epidemic did not spread into neighboring countries, showing that although these regions were susceptible to developing significant outbreaks, they were also at lower risk of viral introductions. Finally, viral genome sequence data uniquely reveals this large epidemic to be a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help inform approaches to intervention in such epidemics in the future.

Published
2016

27. Constraints on planetesimal formation from asteroid compositions

Author

Vernazza, Pierre, Zanda, Brigitte, Binzel, Richard P., Hiroi, Takahiro, Demeo, Francesca E., Birlan, Mirel, Hewins, Roger H., Ricci, L., Barge, Pierre, Lockhart, M., Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Massachusetts Institute of Technology, Brown University, Rutgers University, California Institute of Technology, and Henry, Florence

Subjects
[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Ordinary chondrite meteorites (OCs) are by far the most abundant meteorites (80% of all falls). Their study along with that of other chondrite classes has provided numerous constraints on the formation and early evolution of the solar system, including a) the migration processes that occurred in the protoplanetary disk prior to primary accretion (i.e. planetesimal formation) and their associated timescales, b) the post- (and syn-) accretional heating events, and c) the collisional events that occurred since 4.6 Gyrs. Although petrologic, chemical and isotopic studies of OCs and meteorites in general have largely helped establish a chronology of the earliest events of planetesimal formation, there are several questions that cannot be resolved via laboratory measurements and/or experiments only. These include the formation location of the different classes of ordinary chondrites (and meteorites in general); the initial average size of their parent bodies; the amplitude of the bias in our collections with respect to the compositional distribution of OC-like material in the Asteroid Belt; the number of parent bodies for a given meteorite class (it is typically proposed that each meteorite class has only one parent body); the level of radial mixing experienced by parent bodies after their formation; and their accretion timescale. To investigate answers to these questions, we conducted an extensive spectroscopic survey of 83 main belt S-type asteroids and 5 S-type families as it was recently established unambiguously that these asteroids encompass the parent bodies of OCs. In parallel, we also obtained for the first time spectral measurements for a representative number (53) of unequilibrated ordinary chondrites (UOCs) as those were lacking in current databases (e.g. RELAB; http://www.planetary.brown.edu/relab/). We will present evidence for establishing several new constraints on the planetesimal formation process from our broadened spectral survey.

Published
2013

28. The effect of location and configuration on forearm and upper arm hemodialysis arteriovenous grafts

Author

Farber, Alik, primary, Tan, Tze-Woei, additional, Hu, Bo, additional, Dember, Laura M., additional, Beck, Gerald J., additional, Dixon, Bradley S., additional, Kusek, John W., additional, Feldman, Harold I., additional, Dember, L., additional, Kaufman, J., additional, Hawley, M., additional, Lauer, A., additional, LeSage, P., additional, Nathan, R., additional, Holmberg, E., additional, Braden, G., additional, Ryan, M., additional, Berkowitz, A., additional, Rahman, A., additional, Lucas, B., additional, Santos, R., additional, Reyes, B., additional, Greenberg, A., additional, Berkoben, M., additional, Kovalik, E., additional, Lawson, J., additional, Middleton, J., additional, Schwab, S., additional, Schumm, D., additional, Adams, S., additional, Gitter, K., additional, Cantaffa, T., additional, Quarles, A., additional, Work, J., additional, Rhodes, S., additional, Himmelfarb, J., additional, Whiting, J., additional, Kane, J., additional, Freedman, S., additional, Violette, R., additional, Cyr-Alves, H., additional, Garrison, K., additional, Martin, K., additional, Schmitz, P., additional, Jenkins, V., additional, Cotton, J., additional, Husband, E., additional, Allon, M., additional, Robbin, M., additional, Lockhart, M., additional, Casey, B., additional, Newsome, J., additional, Dixon, B., additional, Franzwa, B., additional, Hunsicker, L., additional, Hoballah, J., additional, Katz, D., additional, Sharp, W., additional, Kresowik, T., additional, Wu, Y., additional, Rayhill, S., additional, Pflederer, T., additional, DuPage, K., additional, Welch, K., additional, Darras, F., additional, Banqero, A., additional, Ketel, B., additional, Wounded Arrow, A., additional, Vazquez, M., additional, Davidson, I., additional, Toto, R., additional, Littmon, L., additional, Ying, C., additional, Lightfoot, T., additional, Quinones, H., additional, Saxena, R., additional, Clagett, P., additional, Valentine, J., additional, Dolmatch, B., additional, Thompson, J., additional, Fenves, A., additional, Pearl, G., additional, Ikizler, A., additional, Egbert, P., additional, McNeil, J., additional, Holmes, D., additional, Freiberger, W., additional, Delmez, J., additional, Windus, D., additional, Coyne, D., additional, Rothstein, M., additional, Shenoy, S., additional, Creaghan, R., additional, Lluka, B., additional, Kusek, J., additional, Meyers, C., additional, Feldman, H., additional, Beck, G., additional, Gassman, J., additional, Greene, T., additional, Hu, B., additional, Bi, S., additional, Liu, A., additional, Radeva, M., additional, Tuason, L., additional, Weiss, B., additional, Levin, N., additional, Besarab, A., additional, Chertow, G., additional, Diener-West, M., additional, Louis, T., additional, McClellan, W., additional, and Stehman-Breen, C., additional

Published
2015
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29. Wavelength calibration from 1-5 mu m for the CRIRES plus high-resolution spectrograph at the VLT

Author

Seemann, U., Anglada-Escude, G., Baade, D., Bristow, P., Dorn, R. J., Follert, R., Gojak, D., Grunhut, J., Hatzes, A. P., Heiter, Ulrike, Ives, D. J., Jeep, P., Jung, Y., Kaeufl, H. -U, Kerber, F., Klein, B., Lizon, J. -L, Lockhart, M., Loewinger, T., Marquart, Thomas, Oliva, E., Paufique, J., Piskunov, Nikolai, Pozna, E., Reiners, A., Smette, A., Smoker, J., Stempels, Eric, Valenti, E., Seemann, U., Anglada-Escude, G., Baade, D., Bristow, P., Dorn, R. J., Follert, R., Gojak, D., Grunhut, J., Hatzes, A. P., Heiter, Ulrike, Ives, D. J., Jeep, P., Jung, Y., Kaeufl, H. -U, Kerber, F., Klein, B., Lizon, J. -L, Lockhart, M., Loewinger, T., Marquart, Thomas, Oliva, E., Paufique, J., Piskunov, Nikolai, Pozna, E., Reiners, A., Smette, A., Smoker, J., Stempels, Eric, and Valenti, E.

Abstract

CRIRES at the VLT is one of the few adaptive optics enabled instruments that offer a resolving power of 10 5 from 1 - 5 mu m. An instrument upgrade (CRIRES+) is proposed to implement cross-dispersion capabilities, spectro-polarimetry modes, a new detector mosaic, and a new gas absorption cell. CRIRES+ will boost the simultaneous wavelength coverage of the current instrument (similar to lambda/70 in a single-order) by a factor of greater than or similar to 10 in the cross-dispersed configuration, while still retaining a 10 arcsec slit suitable for long-slit spectroscopy. CRIRES+ dramatically enhances the instrument's observing efficiency, and opens new scientific opportunities. These include high-precision radial-velocity studies on the 3m/s level to characterize extra-solar planets and their athmospheres, which demand for specialized, highly accurate wavelength calibration techniques. In this paper, we present a newly developed absorption gas-cell to enable high-precision wavelength calibration for CRIRES+. We also discuss the strategies and developments to cover the full operational spectral range (1-5 mu m), employing hollow-cathode emission lamps, Fabry-Perot etalons, and absorption gas-cells.

Published
2014
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30. Program and Algorithm Visualization in Engineering and Physics

Author

Bruce-Lockhart, M. Norvell, T.S. Cotronis, Y.

Subjects
ComputingMilieux_COMPUTERSANDEDUCATION
Abstract

We report here on our experiences using a program animation tool, the Teaching Machine, for program and algorithm visualization for engineering and physics students at two universities: Memorial University, where it has been used since 1999 for teaching engineering students, and the University of Athens, where it was adopted in 2005 to teach physics students. © 2007 Elsevier B.V. All rights reserved.

Published
2007

32. Wavelength calibration from 1-5μm for the CRIRES+ high-resolution spectrograph at the VLT

Author

Seemann, U., additional, Anglada-Escude, G., additional, Baade, D., additional, Bristow, P., additional, Dorn, R. J., additional, Follert, R., additional, Gojak, D., additional, Grunhut, J., additional, Hatzes, A. P., additional, Heiter, U., additional, Ives, D. J., additional, Jeep, P., additional, Jung, Y., additional, Käufl, H.-U., additional, Kerber, F., additional, Klein, B., additional, Lizon, J.-L., additional, Lockhart, M., additional, Löwinger, T., additional, Marquart, T., additional, Oliva, E., additional, Paufique, J., additional, Piskunov, N., additional, Pozna, E., additional, Reiners, A., additional, Smette, A., additional, Smoker, J., additional, Stempels, E., additional, and Valenti, E., additional

Published
2014
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33. Concept and optical design of the cross-disperser module for CRIRES+

Author

Oliva, E., additional, Tozzi, A., additional, Ferruzzi, D., additional, Origlia, L., additional, Hatzes, A., additional, Follert, R., additional, Löwinger, T., additional, Piskunov, N., additional, Heiter, U., additional, Lockhart, M., additional, Marquart, T., additional, Stempels, E., additional, Reiners, A., additional, Anglada-Escude, G., additional, Seemann, Ulf, additional, Dorn, R. J., additional, Bristow, P., additional, Baade, D., additional, Delabre, B., additional, Gojak, D., additional, Grunhut, J., additional, Klein, Barbara, additional, Hilker, M., additional, Ives, D. J., additional, Jung, Y., additional, Kaeufl, H.-U., additional, Kerber, F., additional, Lizon, J. L., additional, Pasquini, L., additional, Paufique, J., additional, Pozna, Eszter, additional, Smette, A., additional, Smoker, J., additional, and Valenti, E., additional

Published
2014
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34. CRIRES+: a cross-dispersed high-resolution infrared spectrograph for the ESO VLT

Author

Follert, R., additional, Dorn, R. J., additional, Oliva, E., additional, Lizon, J. L., additional, Hatzes, A., additional, Piskunov, N., additional, Reiners, A., additional, Seemann, U., additional, Stempels, E., additional, Heiter, U., additional, Marquart, T., additional, Lockhart, M., additional, Anglada-Escude, G., additional, Löwinger, T., additional, Baade, D., additional, Grunhut, J., additional, Bristow, P., additional, Klein, B., additional, Jung, Y., additional, Ives, D. J., additional, Kerber, F., additional, Pozna, E., additional, Paufique, J., additional, Kaeufl, H. U., additional, Origlia, L., additional, Valenti, E., additional, Gojak, D., additional, Hilker, M., additional, Pasquini, L., additional, Smette, A., additional, and Smoker, J., additional

Published
2014
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35. Detecting and measuring small numbers of viable Coxiella burnetii

Author

Lockhart, M., Islam, A., Graves, S., Fenwick, S., Stenos, J., Lockhart, M., Islam, A., Graves, S., Fenwick, S., and Stenos, J.

Abstract

Coxiella burnetii is an acidophilic, intracellular bacterium that causes the human disease Q fever. In some studies, it is important to distinguish between viable and nonviable C. burnetii. We compared four methods for detecting and measuring viable C. burnetii in biological samples as follows: growth in two different cell culture lines, infection of severe combined immunodeficient (SCID) mice (leading to death) and infection of SCID mice with detection of C. burnetii in their spleen (after euthanasia at day 50 postinfection). Two isolates of C. burnetii were used (Henzerling and Arandale). Our in-house qPCR assay for C. burnetii DNA was used as a control. SCID mouse inoculation was more sensitive than cell culture. The assay that detected C. burnetii in SCID mouse spleens was slightly more sensitive than SCID mice deaths alone. Approximately one viable C. burnetii cell could be detected by this method, making it suitable for determining the viability of C. burnetii in a sample.

Published
2012

36. Size and Albedo of Kuiper Belt Object 55636 from a Stellar Occultation

Author

NAVAL OBSERVATORY FLAGSTAFF AZ, Elliot, J. L., Person, M. J., Zuluaga, C. A., Bosh, A. S., Adams, E. R., Brothers, T. C., Gulbis, A. A., Levine, S. E., Lockhart, M., Zangari, A. M., NAVAL OBSERVATORY FLAGSTAFF AZ, Elliot, J. L., Person, M. J., Zuluaga, C. A., Bosh, A. S., Adams, E. R., Brothers, T. C., Gulbis, A. A., Levine, S. E., Lockhart, M., and Zangari, A. M.

Abstract

The Kuiper belt is a collection of small bodies (Kuiper belt objects, KBOs) that lie beyond the orbit of Neptune and which are believed to have formed contemporaneously with the planets. Their small size and great distance make them difficult to study. KBO 55636 (2002 TX300) is a member of the water-ice-rich Haumea KBO collisional family. The Haumea family are among the most highly reflective objects in the Solar System. Dynamical calculations indicate that the collision that created KBO 55636 occurred at least 1Gyr ago. Here we report observations of a multi-chord stellar occultation by KBO 55636, which occurred on 9 October 2009 UT. We find that it has a mean radius of 143+/-5km (assuming a circular solution). Allowing for possible elliptical shapes, we find a geometric albedo of in the V photometric band, which establishes that KBO 55636 is smaller than previously thought and that, like its parent body, it is highly reflective. The dynamical age implies either that KBO 55636 has an active resurfacing mechanism, or that fresh water-ice in the outer Solar System can persist for gigayear timescales., Published in the journal NATURE, v465 n17 p897-900, June 2010. The original document contains color images.

Published
2010

37. Size and albedo of Kuiper belt object 55636 from a stellar occultation

Author

Elliot, J, Person, M, Zuluaga, C. A., Bosh, A S, Adams, E. R., Brothers, T C, Gulbis, A. A. S., Levine, S, Lockhart, M, Zangari, A, Rapoport, Sharon, Elliot, J, Person, M, Zuluaga, C. A., Bosh, A S, Adams, E. R., Brothers, T C, Gulbis, A. A. S., Levine, S, Lockhart, M, Zangari, A, and Rapoport, Sharon

Abstract

The Kuiper belt is a collection of small bodies (Kuiper belt objects, KBOs) that lie beyond the orbit of Neptune and which are believed to have formed contemporaneously with the planets. Their small size and great distance make them difficult to study. KBO 55636 (2002 TX 300) is a member of the water-ice-rich Haumea KBO collisional family. The Haumea family are among the most highly reflective objects in the Solar System. Dynamical calculations indicate that the collision that created KBO 55636 occurred at least 1 Gyr ago. Here we report observations of a multi-chord stellar occultation by KBO 55636, which occurred on 9 October 2009 ut. We find that it has a mean radius of 143 Â ± 5 km (assuming a circular solution). Allowing for possible elliptical shapes, we find a geometric albedo of in the V photometric band, which establishes that KBO 55636 is smaller than previously thought and that, like its parent body, it is highly reflective. The dynamical age implies either that KBO 55636 has an active resurfacing mechanism, or that fresh water-ice in the outer Solar System can persist for gigayear timescales.

Published
2010

38. Signal Processing

Author

Bose, A. G., Bruce, J. D., Nelsen, D. E., Oppenheim, Alan V., Searle, Campbell L., Zimmermann, Henry J., Bruce-Lockhart, M. P., Bose, A. G., Bruce, J. D., Nelsen, D. E., Oppenheim, Alan V., Searle, Campbell L., Zimmermann, Henry J., and Bruce-Lockhart, M. P.

Abstract

Contains research objectives and reports on work completed and one research project., Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)

Published
2010

39. Signal Processing

Author

Kuleshov, V. N., Nelsen, D. E., Oppenheim, Alan V., Johnson, D. H., Bruce-Lockhart, M. P., Kuleshov, V. N., Nelsen, D. E., Oppenheim, Alan V., Johnson, D. H., and Bruce-Lockhart, M. P.

Abstract

Contains reports on three research projects., Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)

Published
2010

41. [Immunobiological characterization of murine LB leukemia and the LBC cell line]

Author

Se, Hajos, Mongini C, Waldner C, Sánchez Lockhart M, Mj, Gravisaco, Roig I, Fernańdez T, and Alvarez E

Subjects
Mice, Mice, Inbred BALB C, Leukemia, T-Lymphocytes, Animals, Cell Division, Cell Line
Abstract

LB leukemia is a nonimmunogenic T cell tumor which spontaneously arose in a BALB/c mouse; efforts to induce immunological rejection of the leukemic cells have always failed. The leukemic cells grow rapidly and progressively in the syngeneic host invading spleen, lymph nodes and liver. A cell line (LBC) was developed from the original tumor. Both the original tumor and the cell line have been characterized as expressing the Thy 1+, CD3-, CD25+, MHC class I+, class II-, CD4- (original tumor), CD4+ (cell line), CD8+, gp70-, J11d.2+ phenotypes. Immunization of syngeneic mice with irradiated LBC cells induced cytotoxic T lymphocytes as well as anti-LBC antibodies which reacted with components of 14, 16 and 27 kDa present on LB tumor cells, LBC cell line and normal thymocytes but not on normal lymph node cells. Immunization of syngeneic mice with LBC cells partially protected them against subsequent challenge with the original tumor cells. The effect of sera from tumor-bearing mice and the super-natants from short term cultures were studied on cell proliferation. An inhibitory activity was demonstrated in these fluids, which was abrogated by addition of exogenous IL-2. ELISA showed the presence of soluble IL-2R alpha chain both in the conditioned medium as well as in the serum, which was demonstrated to be responsible for the inhibitory activity. The soluble IL-2R was produced by LB leukemic cells and exerted the inhibitory activity blocking cell proliferation and modulating immune response by binding to free IL-2. Using reverse-transcription PCR, mRNA for IL-2 was found to be present in tumor cells. Our findings indicate that LB cell proliferation is mediated by an autocrine pathway involving endogenous IL-2 generation, despite the fact that these cells are not dependent on exogenous IL-2 to grow in culture. The relationship between tumorigenicity and expression of MHC class II was also investigated. In vitro treatment with IFN-gamma failed to induce the expression of class II antigens in LBC cell line. Therefore these cells were tri-transfected by a liposome-mediated protocol with 1-A alpha d, I-A beta d genes and pSV2neo. Cells were selected to grow in medium containing Genetecin (G418) and surviving transfectants were cloned. Three I-A+ clones were obtained (LBCT) and were used to induce a specific CTL response against tumor cells. Syngeneic mice inoculated with 10(3) LBCT cells failed to develop a tumor while the DT50 of mice injected with 10(6) LBCT cells was three times the value for mice injected with LBC cells (I-A-). It is suggested that neoexpression of MHC class II molecules enhances anti-tumor response by transforming tumor cells into professional antigen-presenting cells, which may be used to improve tumor-specific immunity in the autologous host.

Published
1996

46. GROUND-BASED MULTISITE OBSERVATIONS OF TWO TRANSITS OF HD 80606b

Author

Shporer, A., primary, Winn, J. N., additional, Dreizler, S., additional, Colón, K. D., additional, Wood-Vasey, W. M., additional, Choi, P. I., additional, Morley, C., additional, Moutou, C., additional, Welsh, W. F., additional, Pollaco, D., additional, Starkey, D., additional, Adams, E., additional, Barros, S. C. C., additional, Bouchy, F., additional, Cabrera-Lavers, A., additional, Cerutti, S., additional, Coban, L., additional, Costello, K., additional, Deeg, H., additional, Díaz, R. F., additional, Esquerdo, G. A., additional, Fernandez, J., additional, Fleming, S. W., additional, Ford, E. B., additional, Fulton, B. J., additional, Good, M., additional, Hébrard, G., additional, Holman, M. J., additional, Hunt, M., additional, Kadakia, S., additional, Lander, G., additional, Lockhart, M., additional, Mazeh, T., additional, Morehead, R. C., additional, Nelson, B. E., additional, Nortmann, L., additional, Reyes, F., additional, Roebuck, E., additional, Rudy, A. R., additional, Ruth, R., additional, Simpson, E., additional, Vincent, C., additional, Weaver, G., additional, and Xie, J.-W., additional

Published
2010
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