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3. Exoplanet X-ray irradiation and evaporation rates with eROSITA

Author

Foster, G., Poppenhaeger, K., Ilic, N., and Schwope, A.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract

High-energy irradiation is a driver for atmospheric evaporation and mass loss in exoplanets. This work is based on data from eROSITA, the soft X-ray instrument aboard SRG (Spectrum Roentgen Gamma) mission, as well as archival data from other missions, we aim to characterise the high-energy environment of known exoplanets and estimate their mass loss rates. We use X-ray source catalogues from eROSITA, XMM-Newton, Chandra and ROSAT to derive X-ray luminosities of exoplanet host stars in the 0.2-2 keV energy band with an underlying coronal, i.e. optically thin thermal spectrum. We present a catalogue of stellar X-ray and EUV luminosities, exoplanetary X-ray and EUV irradiation fluxes and estimated mass loss rates for a total of 287 exoplanets, 96 among them being characterised for the first time from new eROSITA detections. We identify 14 first time X-ray detections of transiting exoplanets that are subject to irradiation levels known to cause observable evaporation signatures in other exoplanets, which makes them suitable targets for follow-up observations., Comment: 13 pages, 11 figures. To appear on A&A, Special Issue: The Early Data Release of eROSITA and Mikhail Pavlinsky ART-XC on the SRG Mission. Electronic data table will be made available on VizieR

Published
2021
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4. Direct-acting antiviral therapies for hepatitis C infection: global registration, reimbursement, and restrictions

Author

Sargsyants, N., Suleymanova, L., Salkic, N., Simonova, M., Nemeth-Blazic, T., Mravcik, V., Kivimets, K., Salupere, R., Butsashvili, M., Soselia, G., Makara, M., Tolmane, I., Jancorienė, L., Stratulat, S., Flisiak, R., Gheorghe, L., Cernat, R., Lakhov, A., Stanevich, O., Jarcuska, P., Peck-Radosavljevic, M., Robaeys, G., Øvrehus, A., Foster, G., Sutinen, J., Farkkila, M., Rautiainen, H., Vuoti, S., Nikolova, D., Pawlotsky, J.M., Rockstroh, J., Sypsa, V., Papatheodoridis, G., Olafsson, S., Feeney, E., Teti, E., Seguin-Devaux, C., Pocock, J., Reiff, S., McDougall, N., Van der Valk, M., Dalgard, O., Tato Marinho, R., Dillon, J., Peters, E., Bojovic, K., Matičič, M., Kåberg, M., Bruggmann, P., Healy, B., Chong, V.H., Yi, S., Tucker, J., Pasaribu, L.R., Tanaka, J., Ashley, E.A., Abu Hassan, M.R., Mohammed, N.S., Chan, H.K., Gidaagaya, S., Kyi, K.P., Hyung Joon, K., Chin, B., Baladjay, P.C., Kao, J.H., Wansom, T., da Cruz, B., Flower, B., Ehsan, E., Al Mahtab, M., Khandu, L., Bhadoria, A.S., Alavi, M., KC, P., Hamid, S., Biryukov, S., Alymbaeva, D., Alaei, A., Bakieva, S., Flichman, D., Carmo, R.F., Valdez, E., Cortes, C.P., Contreras, F., Teran, E., Velez-Moller, P., Jagnarine, T., Mills, M., Goodman-Meza, D., Sánchez, J., Montenegro-Idrogo, J.J., Lugo Canales, A.M., Davy, J., Alexander, A., Gerona, S., Perazzo, R., Balak, D., Kelly-Hanku, A., Fineanganofo, A., Gane, E., Raymond, N., Debzi, N., Sridharan, K., Waked, I., Turner, D., Shibolet, O., Al Muzaini, A., El Nakib, M., Sheriff, D.S., Brahni, T., Essayagh, T., Essayagh, S., Hjaija, D., Al-Naamani, K., Sanai, F.M., Pasquale, H., Bedri, S., Chakroun, M., Ghrabi, A., Akarca, U.S., Falcao, V., Edmond Gbedo, S., Ouoba, S., Nyabenda, F., Rocher Mbella, M., Mahamat Moussa, A., Youssouf, T., Boniface, Y., Akilimali Shindano, T., Hamida, M.E., Mongo, A., Mapapa, C., Desalegn, H., Embinga, E.L.A., Ndow, G., Nartey, Y., Cisse, M., Djalo, M.A., Mugambi, M., Nyakowa, M., Jeuronlon, M.K., Ngoma, J., Manitrala Ramanampamonjy, R., Naik, K., Soyjaudah, M.D., Filipe, E., Nnakelu, E., Serumondo, J., Mbodj, M., Patino, M., Aalto, M.K., Waweru, P., Dagnra, A., Ocama, P., Maghimbi, A., Hamooya, B.M., Katsidzira, L., Rios, C., Thormann, M., Al Marzooqi, N., Al Rand, H.M., Francois, K., Hamoudi, W., Alkharty, M., Skripo, O., Uka, T., Marshall, Alison D, Willing, Alex R, Kairouz, Abe, Cunningham, Evan B, Wheeler, Alice, O’Brien, Nicholas, Perera, Vidura, Ward, John W, Hiebert, Lindsey, Degenhardt, Louisa, Hajarizadeh, Behzad, Colledge, Samantha, Hickman, Matthew, Jawad, Danielle, Lazarus, Jeffrey V, Matthews, Gail V, Scheibe, Andrew, Vickerman, Peter, Dore, Gregory J, and Grebely, Jason

Published
2024
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6. Adjusted estimate of the prevalence of hepatitis delta virus in 25 countries and territories

Author

Razavi-Shearer, D., Child, H., Razavi-Shearer, K., Voeller, A., Razavi, H., Buti, M., Tacke, F., Terrault, N., Zeuzem, S., Abbas, Z., Aghemo, A., Akarca, U.S., Al Masri, N., Alalwan, A., Blomé, M. Alanko, Jerkeman, A., Aleman, S., Kamal, H., Alghamdi, A., Alghamdi, M., Alghamdi, S., Al-Hamoudi, W., Ali, E., Aljumah, A., Altraif, I., Amarsanaa, J., Asselah, T., Baatarkhuu, O., Babameto, A., Ben-Ari, Z., Berg, T., Biondi, M., Braga, W., Brandão-Mello, C., Brown, R., Brunetto, M., Cabezas, J., Cardoso, M., Martins, A., Chan, H.L.Y., Cheinquer, H., Chen, C.-J., Yang, H.-I., Chen, P.-J., Chien, C.-H., Chuang, W.-L., Garza, L. Cisneros, Coco, B., Coffin, C., Coppola, N., Cornberg, M., Craxi, A., Crespo, J., Cuko, L., De Ledinghen, V., Duberg, A.-S., Etzion, O., Ferraz, M.L., Ferreira, P., Forns, X., Foster, G., Fung, J., Gaeta, G., García-Samaniego, J., Genov, J., Gheorghe, L., Gholam, P., Gish, R., Glenn, J., Hamid, S., Hercun, J., Hsu, Y.-C., Hu, C.-C., Huang, J.-F., Idilman, R., Jafri, W., Janjua, N., Jelev, D., Jia, J., Kåberg, M., Kaita, K., Kao, J.-H., Khan, A., Kim, D.Y., Kondili, L., Lagging, M., Lampertico, P., Lázaro, P., Lazarus, J.V., Lee, M.-H., Lim, Y.-S., Lobato, C., Macedo, G., Marinho, R., Marotta, P., Mendes-Correa, M.C., Méndez-Sánchez, N., Navas, M.-C., Ning, Q., Örmeci, N., Orrego, M., Osiowy, C., Pan, C., Pessoa, M., Piracha, Z., Pop, C., Qureshi, H., Raimondo, G., Ramji, A., Ribeiro, S., Ríos-Hincapié, C., Rodríguez, M., Rosenberg, W., Roulot, D., Ryder, S., Saeed, U., Safadi, R., Shouval, D., Sanai, F., Sanchez-Avila, J.F., Santantonio, T., Sarrazin, C., Seto, W.-K., Simonova, M., Tanaka, J., Tergast, T., Tsendsuren, O., Valente, C., Villalobos-Salcedo, J.M., Waheed, Y., Wong, G., Wong, V., Yip, T., Wu, J.-C., Yu, M.-L., Yuen, M.-F., Yurdaydin, C., and Zuckerman, E.

Published
2024
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8. Fast algorithms to approximate the position-dependent point spread function responses in radio interferometric wide-field imaging

Author

Atemkeng, M., Smirnov, O., Tasse, C., Foster, G., and Makhathini, S.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The desire for wide-field of view, large fractional bandwidth, high sensitivity, high spectral and temporal resolution has driven radio interferometry to the point of big data revolution where the data is represented in at least three dimensions with an axis for spectral windows, baselines, sources, etc; where each axis has its own set of sub-dimensions. The cost associated with storing and handling these data is very large, and therefore several techniques to compress interferometric data and/or speed up processing have been investigated. Unfortunately, averaging-based methods for visibility data compression are detrimental to the data fidelity, since the point spread function (PSF) is position-dependent, i.e. distorted and attenuated as a function of distance from the phase centre. The position dependence of the PSF becomes more severe, requiring more PSF computations for wide-field imaging. Deconvolution algorithms must take the distortion into account in the major and minor cycles to properly subtract the PSF and recover the fidelity of the image. This approach is expensive in computation since at each deconvolution iteration a distorted PSF must be computed. We present two algorithms that approximate these position-dependent PSFs with fewer computations. The first algorithm approximates the position-dependent PSFs in the $uv$-plane and the second algorithm approximates the position-dependent PSFs in the image-plane. The proposed algorithms are validated using simulated data from the MeerKAT telescope., Comment: 13 PAGES

Published
2020
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9. The corona of GJ 1151 in the context of star-planet interaction

Author

Foster, G., Poppenhaeger, K., Alvarado-Gómez, J. D., and Schmitt, J. H. M. M.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The low-mass star GJ 1151 has been reported to display variable low-frequency radio emission, which has been interpreted as a signpost of coronal star-planet interactions with an unseen exoplanet. Here we report the first X-ray detection of GJ 1151's corona based on XMM-Newton data. We find that the star displays a small flare during the X-ray observation. Averaged over the observation, we detect the star with a low coronal temperature of 1.6~MK and an X-ray luminosity of $L_X = 5.5\times 10^{26}$\,erg/s. During the quiescent time periods excluding the flare, the star remains undetected with an upper limit of $L_{X,\,qui} \leq 3.7\times 10^{26}$\,erg/s. This is compatible with the coronal assumptions used in a recently published model for a star-planet interaction origin of the observed radio signals from this star.

Published
2020
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10. Initial results from a realtime FRB search with the GBT

Author

Agarwal, Devansh, Lorimer, D. R., Surnis, M. P., Pei, X., Karastergiou, A., Golpayegani, G., Werthimer, D., Cobb, J., McLaughlin, M. A., White, S., Armour, W., MacMahon, D. H. E., Siemion, A. P. V., and Foster, G.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We present the data analysis pipeline, commissioning observations and initial results from the GREENBURST fast radio burst (FRB) detection system on the Robert C. Byrd Green Bank Telescope (GBT) previously described by Surnis et al. which uses the 21~cm receiver observing commensally with other projects. The pipeline makes use of a state-of-the-art deep learning classifier to winnow down the very large number of false positive single-pulse candidates that mostly result from radio frequency interference. In our observations totalling 156.5 days so far, we have detected individual pulses from 20 known radio pulsars which provide an excellent verification of the system performance. We also demonstrate, through blind injection analyses, that our pipeline is complete down to a signal-to-noise threshold of 12. Depending on the observing mode, this translates to peak flux sensitivities in the range 0.14--0.89~Jy. Although no FRBs have been detected to date, we have used our results to update the analysis of Lawrence et al. to constrain the FRB all-sky rate to be $1140^{+200}_{-180}$ per day above a peak flux density of 1~Jy. We also constrain the source count index $\alpha=0.83\pm0.06$ which indicates that the source count distribution is substantially flatter than expected from a Euclidean distribution of standard candles (where $\alpha=1.5$). We discuss this result in the context of the FRB redshift and luminosity distributions. Finally, we make predictions for detection rates with GREENBURST, as well as other ongoing and planned FRB experiments., Comment: 9 pages, 7 figures, submitted to MNRAS

Published
2020
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11. A Fast Radio Burst with frequency-dependent polarization detected during Breakthrough Listen observations

Author

Price, D. C., Foster, G., Geyer, M., van Straten, W., Gajjar, V., Hellbourg, G., Karastergiou, A., Keane, E. F., Siemion, A. P. V., Arcavi, I., Bhat, R., Caleb, M., Chang, S-W., Croft, S., DeBoer, D., de Pater, I., Drew, J., Enriquez, J. E., Farah, W., Gizani, N., Green, J. A., Isaacson, H., Hickish, J., Jameson, A., Lebofsky, M., MacMahon, D. H. E., Möller, A., Onken, C. A., Petroff, E., Werthimer, D., Wolf, C., Worden, S. P., and Zhang, Y. G.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Here, we report on the detection and verification of Fast Radio Burst FRB 180301, which occurred on UTC 2018 March 1 during the Breakthrough Listen observations with the Parkes telescope. Full-polarization voltage data of the detection were captured--a first for non-repeating FRBs--allowing for coherent de-dispersion and additional verification tests. The coherently de-dispersed dynamic spectrum of FRB 180301 shows complex, polarized frequency structure over a small fractional bandwidth. As FRB 180301 was detected close to the geosynchronous satellite band during a time of known 1-2 GHz satellite transmissions, we consider whether the burst was due to radio interference emitted or reflected from an orbiting object. Based on the preponderance of our verification tests, we find that FRB 180301 is likely of astrophysical origin, but caution that anthropogenic sources cannot conclusively be ruled out., Comment: Submitted to MNRAS

Published
2019
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14. Highest-frequency detection of FRB 121102 at 4-8 GHz using the Breakthrough Listen Digital Backend at the Green Bank Telescope

Author

Gajjar, V., Siemion, A. P. V., Price, D. C., Law, C. J., Michilli, D., Hessels, J. W. T., Chatterjee, S., Archibald, A. M., Bower, G. C., Brinkman, C., Burke-Spolaor, S., Cordes, J. M., Croft, S., Enriquez, J. Emilio, Foster, G., Gizani, N., Hellbourg, G., Isaacson, H., Kaspi, V. M., Lazio, T. J. W., Lebofsky, M., Lynch, R. S., MacMahon, D., McLaughlin, M. A., Ransom, S. M., Scholz, P., Seymour, A., Spitler, L. G., Tendulkar, S. P., Werthimer, D., and Zhang, Y. G.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report the first detections of the repeating fast radio burst source FRB 121102 above 5.2 GHz. Observations were performed using the 4$-$8 GHz receiver of the Robert C. Byrd Green Bank Telescope with the Breakthrough Listen digital backend. We present the spectral, temporal and polarization properties of 21 bursts detected within the first 60 minutes of a total 6-hour observations. These observations comprise the highest burst density yet reported in the literature, with 18 bursts being detected in the first 30 minutes. A few bursts clearly show temporal sub-structures with distinct spectral properties. These sub-structures superimpose to provide enhanced peak signal-to-noise ratio at higher trial dispersion measures. Broad features occur in $\sim 1$ GHz wide subbands that typically differ in peak frequency between bursts within the band. Finer-scale structures ($\sim 10-50$ MHz) within these bursts are consistent with that expected from Galactic diffractive interstellar scintillation. The bursts exhibit nearly 100% linear polarization, and a large average rotation measure of 9.359$\pm$0.012 $\times$ 10$^{\rm 4}$ rad m$^{\rm -2}$ (in the observer's frame). No circular polarization was found for any burst. We measure an approximately constant polarization position angle in the 13 brightest bursts. The peak flux densities of the reported bursts have average values (0.2$\pm$0.1 Jy), similar to those seen at lower frequencies ($<3$ GHz), while the average burst widths (0.64$\pm$0.46 ms) are relatively narrower., Comment: Accepted for publication in ApJ

Published
2018
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15. Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

Author

Camilo, F., Scholz, P., Serylak, M., Buchner, S., Merryfield, M., Kaspi, V. M., Archibald, R. F., Bailes, M., Jameson, A., van Straten, W., Sarkissian, J., Reynolds, J. E., Johnston, S., Hobbs, G., Abbott, T. D., Adam, R. M., Adams, G. B., Alberts, T., Andreas, R., Asad, K. M. B., Baker, D. E., Baloyi, T., Bauermeister, E. F., Baxana, T., Bennett, T. G. H., Bernardi, G., Booisen, D., Booth, R. S., Botha, D. H., Boyana, L., Brederode, L. R. S., Burger, J. P., Cheetham, T., Conradie, J., Conradie, J. P., Davidson, D. B., de Bruin, G., de Swardt, B., de Villiers, C., de Villiers, D. I. L., de Villiers, M. S., de Villiers, W., de Waal, C., Dikgale, M. A., Toit, G. du, Toit, L. J. du, Esterhuyse, S. W. P., Fanaroff, B., Fataar, S., Foley, A. R., Foster, G., Fourie, D., Gamatham, R., Gatsi, T., Geschke, R., Goedhart, S., Grobler, T. L., Gumede, S. C., Hlakola, M. J., Hokwana, A., Hoorn, D. H., Horn, D., Horrell, J., Hugo, B., Isaacson, A., Jacobs, O., van Rensburg, J. P. Jansen, Jonas, J. L., Jordaan, B., Joubert, A., Joubert, F., Jozsa, G. I. G., Julie, R., Julius, C. C., Kapp, F., Karastergiou, A., Karels, F., Kariseb, M., Karuppusamy, R., Kasper, V., Knox-Davies, E. C., Koch, D., Kotze, P. P. A., Krebs, A., Kriek, N., Kriel, H., Kusel, T., Lamoor, S., Lehmensiek, R., Liebenberg, D., Liebenberg, I., Lord, R. T., Lunsky, B., Mabombo, N., Macdonald, T., Macfarlane, P., Madisa, K., Mafhungo, L., Magnus, L. G., Magozore, C., Mahgoub, O., Main, J. P. L., Makhathini, S., Malan, J. A., Malgas, P., Manley, J. R., Manzini, M., Marais, L., Marais, N., Marais, S. J., Maree, M., Martens, A., Matshawule, S. D., Matthysen, N., Mauch, T., Nally, L. D. Mc, Merry, B., Millenaar, R. P., Mjikelo, C., Mkhabela, N., Mnyandu, N., Moeng, I. T., Mokone, O. J., Monama, T. E., Montshiwa, K., Moss, V., Mphego, M., New, W., Ngcebetsha, B., Ngoasheng, K., Niehaus, H., Ntuli, P., Nzama, A., Obies, F., Obrocka, M., Ockards, M. T., Olyn, C., Oozeer, N., Otto, A. J., Padayachee, Y., Passmoor, S., Patel, A. A., Paula, S., Peens-Hough, A., Pholoholo, B., Prozesky, P., Rakoma, S., Ramaila, A. J. T., Rammala, I., Ramudzuli, Z. R., Rasivhaga, M., Ratcliffe, S., Reader, H. C., Renil, R., Richter, L., Robyntjies, A., Rosekrans, D., Rust, A., Salie, S., Sambu, N., Schollar, C. T. G., Schwardt, L., Seranyane, S., Sethosa, G., Sharpe, C., Siebrits, R., Sirothia, S. K., Slabber, M. J., Smirnov, O., Smith, S., Sofeya, L., Songqumase, N., Spann, R., Stappers, B., Steyn, D., Steyn, T. J., Strong, R., Struthers, A., Stuart, C., Sunnylall, P., Swart, P. S., Taljaard, B., Tasse, C., Taylor, G., Theron, I. P., Thondikulam, V., Thorat, K., Tiplady, A., Toruvanda, O., van Aardt, J., van Balla, T., Heever, L. van den, van der Byl, A., van der Merwe, C., van der Merwe, P., van Niekerk, P. C., van Rooyen, R., van Staden, J. P., van Tonder, V., van Wyk, R., Wait, I., Walker, A. L., Wallace, B., Welz, M., Williams, L. P., Xaia, B., Young, N., and Zitha, S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation., Comment: Published in ApJ (2018 April 5); 13 pages, 4 figures

Published
2018
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16. Baseline-dependent sampling and windowing for radio interferometry: data compression, field-of-interest shaping and outer field suppression

Author

Atemkeng, M., Smirnov, O., Tasse, C., Foster, G., Keimpema, A., Paragi, Z., and Jonas, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Traditional radio interferometric correlators produce regular-gridded samples of the true $uv$-distribution by averaging the signal over constant, discrete time-frequency intervals. This regular sampling and averaging then translate to be irregular-gridded samples in the $uv$-space, and results in a baseline-length-dependent loss of amplitude and phase coherence, which is dependent on the distance from the image phase centre. The effect is often referred to as "decorrelation" in the $uv$-space, which is equivalent in the source domain to "smearing". This work discusses and implements a regular-gridded sampling scheme in the $uv$-space (baseline-dependent sampling) and windowing that allow for data compression, field-of-interest shaping and source suppression. The baseline-dependent sampling requires irregular-gridded sampling in the time-frequency space i.e. the time-frequency interval becomes baseline-dependent. Analytic models and simulations are used to show that decorrelation remains constant across all the baselines when applying baseline-dependent sampling and windowing. Simulations using MeerKAT telescope and the European Very Long Baseline Interferometry Network show that both data compression, field-of-interest shaping and outer field-of-interest suppression are achieved.

Published
2018
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19. Constraining Polarized Foregrounds for EOR Experiments II: Polarization Leakage Simulations in the Avoidance Scheme

Author

Nunhokee, C. D., Bernardi, G., Kohn, S. A., Aguirre, J. E., Thyagarajan, N., Dillon, J. S., Foster, G., Grobler, T. L., Martinot, J. Z. E., and Parsons, A. R.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

A critical challenge in the observation of the redshifted 21-cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21-cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. (2012). We construct polarized sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of polarized point sources is expected to be higher than diffuse Galactic polarization at any $k$ mode for a 30~m reference baseline. For the same reference baseline, a foreground-free window at $k > 0.3 \, h$~Mpc$^{-1}$ can be defined in terms of leakage from diffuse Galactic polarization even under the most pessimistic assumptions. If measurements of polarized foreground power spectra or a model of polarized foregrounds are given, our method is able to predict the polarization leakage in actual 21-cm observations, potentially enabling its statistical subtraction from the measured 21-cm power spectrum., Comment: 11 pages, 10 figures, ApJ accepted

Published
2017
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20. Bayesian Errors‐in‐Variables Estimation of Specific Climate Sensitivity.

Author

Heslop, D., Rohling, E. J., Foster, G. L., and Yu, J.

Subjects
CLIMATE change, EOCENE Epoch, GLOBAL warming, GEOLOGICAL time scales, SURFACE temperature, ATMOSPHERIC carbon dioxide
Abstract

Estimation of climate sensitivity is fundamental to assessing how global climate will warm as atmospheric CO2 ${\mathrm{C}\mathrm{O}}_{2}$ concentration increases. Geological archives of environmental change provide insights into Earth's past climate, but the incomplete nature of paleoclimate reconstructions and their inherent uncertainties make estimation of climate sensitivity challenging. Thus, quantifying climate sensitivity and assessing how it changed through geological time requires statistical frameworks that can handle data uncertainties in a principled fashion. Here we demonstrate some of the hurdles to estimating climate sensitivity, with a focus on current statistical techniques that may underestimate both climate sensitivity and its associated uncertainty. To solve these issues, we present a Bayesian error‐in‐variables regression model, which can yield estimates of climate sensitivity without bias. The regression model is flexible and can account for data point uncertainties with a known parametric form. The utility of this approach is demonstrated by estimating specific climate sensitivity with uncertainty for the Eocene. Plain Language Summary: As atmospheric CO2 ${\mathrm{C}\mathrm{O}}_{2}$ increases due to human activities, the Earth will warm. But how much warming can be expected? Climate sensitivity describes how much global average surface temperature will warm with a given increase in atmospheric CO2 ${\mathrm{C}\mathrm{O}}_{2}$. While this is a simple definition, estimating climate sensitivity is difficult because Earth's climate system is complex with a number of poorly understood interacting parts. One approach to estimating climate sensitivity is to quantify how Earth's climate changed as a result of variations in atmospheric CO2 ${\mathrm{C}\mathrm{O}}_{2}$ through geological time. This information is invaluable, but it is patchy and has large uncertainties that make estimating climate sensitivity challenging. In particular, existing statistical techniques may underestimate climate sensitivity and, thus, underestimate future warming. In this paper we present an alternative approach to determining climate sensitivity that overcomes the underestimation problem and demonstrate its performance using geological data from the Eocene epoch. Key Points: We demonstrate that regression‐based estimates of specific climate sensitivity may be biased toward zero because of data uncertaintiesA Bayesian error‐in‐variables approach is developed that accounts for data uncertainties in regression‐based climate sensitivity estimatesEocene specific climate sensitivity is estimated to demonstrate the utility of Bayesian error‐in‐variables regression [ABSTRACT FROM AUTHOR]

Published
2024
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22. Highest Frequency Detection of FRB 121102 at 4–8 GHz Using the Breakthrough Listen Digital Backend at the Green Bank Telescope

Author

Gajjar, V, Siemion, APV, Price, DC, Law, CJ, Michilli, D, Hessels, JWT, Chatterjee, S, Archibald, AM, Bower, GC, Brinkman, C, Burke-Spolaor, S, Cordes, JM, Croft, S, Enriquez, J Emilio, Foster, G, Gizani, N, Hellbourg, G, Isaacson, H, Kaspi, VM, Lazio, TJW, Lebofsky, M, Lynch, RS, MacMahon, D, McLaughlin, MA, Ransom, SM, Scholz, P, Seymour, A, Spitler, LG, Tendulkar, SP, Werthimer, D, and Zhang, YG

Subjects
radio continuum: stars, stars: neutron, supernovae: general, astro-ph.HE, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

We report the first detections of the repeating fast radio burst source FRB 121102 above 5.2 GHz. Observations were performed using the 4-8 GHz receiver of the Robert C. Byrd Green Bank Telescope with the Breakthrough Listen digital backend. We present the spectral, temporal, and polarization properties of 21 bursts detected within the first 60 minutes of a total of 6 hr of observations. These observations comprise the highest burst density yet reported in the literature, with 18 bursts being detected in the first 30 minutes. A few bursts clearly show temporal sub-structure with distinct spectral properties. These sub-structures superimpose to provide an enhanced peak signal-to-noise ratio at higher trial dispersion measures. Broad features occur in ∼1 GHz wide subbands that typically differ in peak frequency between bursts within the band. Finer-scale structures (∼10-50 MHz) within these bursts are consistent with the structure expected from Galactic diffractive interstellar scintillation. The bursts exhibit nearly 100% linear polarization, and a large average rotation measure of 9.359 ± 0.012 ×104 rad m-2 (in the observer's frame). No circular polarization was found for any burst. We measure an approximately constant polarization position angle in the 13 brightest bursts. The peak flux densities of the reported bursts have average values (0.2 ± 0.1 Jy) similar to those seen at lower frequencies (

Published
2018

23. Towards a Theatre for Gamers : a new paradigm of practice in contemporary live performance as a response to games and interactivity in digital media and performance culture

Author

Foster, G. H.

Subjects
700
Abstract

How can game design, in terms of its concepts, theories, technologies and notions of play, be applied to the design of live performance and engage the new game playing audience within contemporary society? To investigate this I have carried out a practice-as-research project within an ethnographic framework and informed by action research methodologies. This study has created a practical and theoretical framework (expressed as approaches) for the application of gaming methodologies for use in the devising of contemporary performance. A Theatre for Gamers has been developed upon three pillars, which are inspired from gaming culture and practice: Agency, Interactivity and Play. Jacques Rancière (2007) has suggested the concept of emancipating the spectator and my research links this argument to concepts of agency and argues that games have the potential to address part of this concern. My research develops understandings of interactivity in performance by applying game-based notions of ergodic and cyber text (Espen Aarseth, 1997) to the field of live performance. It also draws upon fundamental game design principles, such as interactive feedback loops and story-worlds, as presented by Eric Zimmerman (2003) and Chris Crawford (2012), amongst other game theorists/designers. A Theatre for Gamers acknowledges play as a cultural form (Huizinga, 1938) and introduces understandings of contemporary gaming culture, such as McGonigal’s four gamer qualities (2011), into live performance. Several shifts in the approach to live performance for gamers emerge through this research. The focus of activity now centres on the audience and offers them deep interactivity by repositioning them into the roles of players. Performance practitioners become facilitators for live experiences and no longer assume authority over linear, direct storytelling or traditional performance. The process of storytelling focuses more on creating story-worlds, as opposed to story lines (Crawford, 2012), which encourage a more systemic approach to the development of performance and aims to encourage emergent behaviours and narrative.

Published
2017

24. Fano q-reversal in topological insulator Bi2Se3

Author

Dordevic, S. V., Foster, G. M., Wolf, M. S., Stojilovic, N., Lei, H., Petrovic, C., Chen, Z., Li, Z. Q., and Tung, L. C.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We studied magneto-optical response of a canonical topological insulator Bi$_2$Se$_3$ with the goal of addressing a controversial issue of electron-phonon coupling. Magnetic-field induced modifications of reflectance are very pronounced in the infrared part of the spectrum, indicating strong electron-phonon coupling. This coupling causes an asymmetric line-shape of the 60 cm$^{-1}$ phonon mode, and is analyzed within the Fano formalism. The analysis reveals that the Fano asymmetry parameter (q) changes sign when the cyclotron resonance is degenerate with the phonon mode. To the best of our knowledge this is the first example of magnetic field driven q-reversal.

Published
2016
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25. Using baseline-dependent window functions for data compression and field-of-interest shaping in radio interferometry

Author

Atemkeng, M. T., Smirnov, O. M., Tasse, C., Foster, G., and Jonas, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

In radio interferometry, observed visibilities are intrinsically sampled at some interval in time and frequency. Modern interferometers are capable of producing data at very high time and frequency resolution; practical limits on storage and computation costs require that some form of data compression be imposed. The traditional form of compression is a simple averaging of the visibilities over coarser time and frequency bins. This has an undesired side effect: the resulting averaged visibilities "decorrelate", and do so differently depending on the baseline length and averaging interval. This translates into a non-trivial signature in the image domain known as "smearing", which manifests itself as an attenuation in amplitude towards off-centre sources. With the increasing fields of view and/or longer baselines employed in modern and future instruments, the trade-off between data rate and smearing becomes increasingly unfavourable. In this work we investigate alternative approaches to low-loss data compression. We show that averaging of the visibility data can be treated as a form of convolution by a boxcar-like window function, and that by employing alternative baseline-dependent window functions a more optimal interferometer smearing response may be induced. In particular, we show improved amplitude response over a chosen field of interest, and better attenuation of sources outside the field of interest. The main cost of this technique is a reduction in nominal sensitivity; we investigate the smearing vs. sensitivity trade-off, and show that in certain regimes a favourable compromise can be achieved. We show the application of this technique to simulated data from the Karl G. Jansky Very Large Array (VLA) and the European Very-long-baseline interferometry Network (EVN).

Published
2016
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26. The Electronics and Data Acquisition System for the DarkSide-50 Veto Detectors

Author

Agnes, P., Agostino, L., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Arisaka, K., Back, H. O., Baldin, B., Biery, K., Bonfini, G., Bossa, M., Bottino, B., Brigatti, A., Brodsky, J., Budano, F., Bussino, S., Cadeddu, M., Cadoni, M., Calaprice, F., Canci, N., Candela, A., Cao, H., Cariello, M., Carlini, M., Catalanotti, S., Cavalcante, P., Chepurnov, A., Cocco, A. G., Covone, G., Crippa, L., D'Angelo, D., D'Incecco, M., Davini, S., De Cecco, S., De Deo, M., De Vincenzi, M., Derbin, A., Devoto, A., Di Eusanio, F., Di Pietro, G., Edkins, E., Empl, A., Fan, A., Fiorillo, G., Fomenko, K., Foster, G., Franco, D., Gabriele, F., Galbiati, C., Giganti, C., Goretti, A. M., Granato, F., Grandi, L., Gromov, M., Guan, M., Guardincerri, Y., Hackett, B. R., Herner, K. R., Hungerford, E. V., Ianni, Aldo, Ianni, Andrea, James, I., Jollet, C., Keeter, K., Kendziora, C. L., Kobychev, V., Koh, G., Korablev, D., Korga, G., Kubankin, A., Li, X., Lissia, M., Lombardi, P., Luitz, S., Ma, Y., Machulin, I. N., Mandarano, A., Mari, S. M., Maricic, J., Marini, L., Martoff, C. J., Meregaglia, A., Meyers, P. D., Miletic, T., Milincic, R., Montanari, D., Monte, A., Montuschi, M., Monzani, M. E., Mosteiro, P., Mount, B. J., Muratova, V. N., Musico, P., Napolitano, J., Nelson, A., Odrowski, S., Orsini, M., Ortica, F., Pagani, L., Pallavicini, M., Pantic, E., Parmeggiano, S., Pelczar, K., Pelliccia, N., Pocar, A., Pordes, S., Pugachev, D. A., Qian, H., Randle, K., Ranucci, G., Razeto, A., Reinhold, B., Renshaw, A. L., Riffard, Q., Romani, A., Rossi, B., Rossi, N., Rountree, S. D., Sablone, D., Saggese, P., Saldanha, R., Sands, W., Sangiorgio, S., Savarese, C., Segreto, E., Semenov, D. A., Shields, E., Singh, P. N., Skorokhvatov, M. D., Smirnov, O., Sotnikov, A., Stanford, C., Suvorov, Y., Tartaglia, R., Tatarowicz, J., Testera, G., Tonazzo, A., Trinchese, P., Unzhakov, E. V., Vishneva, A., Vogelaar, R. B., Wada, M., Walker, S., Wang, H., Wang, Y., Watson, A. W., Westerdale, S., Wilhelmi, J., Wojcik, M. M., Xiang, X., Xu, J., Yang, C., Yoo, J., Zavatarelli, S., Zec, A., Zhong, W., Zhu, C., and Zuzel, G.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

DarkSide-50 is a detector for dark matter candidates in the form of weakly interacting massive particles (WIMPs). It utilizes a liquid argon time projection chamber (LAr TPC) for the inner main detector. The TPC is surrounded by a liquid scintillator veto (LSV) and a water Cherenkov veto detector (WCV). The LSV and WCV, both instrumented with PMTs, act as the neutron and cosmogenic muon veto detectors for DarkSide-50. This paper describes the electronics and data acquisition system used for these two detectors.

Published
2016
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27. The veto system of the DarkSide-50 experiment

Author

The DarkSide Collaboration, Agnes, P., Agostino, L., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Arisaka, K., Back, H. O., Baldin, B., Biery, K., Bonfini, G., Bossa, M., Bottino, B., Brigatti, A., Brodsky, J., Budano, F., Bussino, S., Cadeddu, M., Cadonati, L., Cadoni, M., Calaprice, F., Canci, N., Candela, A., Cao, H., Cariello, M., Carlini, M., Catalanotti, S., Cavalcante, P., Chepurnov, A., Cocco, A. G., Covone, G., Crippa, L., D'Angelo, D., D'Incecco, M., Davini, S., De Cecco, S., De Deo, M., De Vincenzi, M., Derbin, A., Devoto, A., Di Eusanio, F., Di Pietro, G., Edkins, E., Empl, A., Fan, A., Fiorillo, G., Fomenko, K., Foster, G., Franco, D., Gabriele, F., Galbiati, C., Giganti, C., Goretti, A. M., Granato, F., Grandi, L., Gromov, M., Guan, M., Guardincerri, Y., Hackett, B. R., Herner, K. R., Hungerford, E. V., Ianni, Aldo, Ianni, Andrea, James, I., Johnson, T., Jollet, C., Keeter, K., Kendziora, C. L., Kobychev, V., Koh, G., Korablev, D., Korga, G., Kubankin, A., Li, X., Lissia, M., Lombardi, P., Luitz, S., Ma, Y., Machulin, I. N., Mandarano, A., Mari, S. M., Maricic, J., Marini, L., Martoff, C. J., Meregaglia, A., Meyers, P. D., Miletic, T., Milincic, R., Montanari, D., Monte, A., Montuschi, M., Monzani, M. E., Mosteiro, P., Mount, B. J., Muratova, V. N., Musico, P., Napolitano, J., Nelson, A., Odrowski, S., Orsini, M., Ortica, F., Pagani, L., Pallavicini, M., Pantic, E., Parmeggiano, S., Pelczar, K., Pelliccia, N., Perasso, S., Pocar, A., Pordes, S., Pugachev, D. A., Qian, H., Randle, K., Ranucci, G., Razeto, A., Reinhold, B., Renshaw, A. L., Romani, A., Rossi, B., Rossi, N., Rountree, S. D., Sablone, D., Saggese, P., Saldanha, R., Sands, W., Sangiorgio, S., Savarese, C., Segreto, E., Semenov, D. A., Shields, E., Singh, P. N., Skorokhvatov, M. D., Smirnov, O., Sotnikov, A., Stanford, C., Suvorov, Y., Tartaglia, R., Tatarowicz, J., Testera, G., Tonazzo, A., Trinchese, P., Unzhakov, E. V., Vishneva, A., Vogelaar, B., Wada, M., Walker, S., Wang, H., Wang, Y., Watson, A. W., Westerdale, S., Wilhelmi, J., Wojcik, M. M., Xiang, X., Xu, J., Yang, C., Yoo, J., Zavatarelli, S., Zec, A., Zhong, W., Zhu, C., and Zuzel, G.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Nuclear recoil events produced by neutron scatters form one of the most important classes of background in WIMP direct detection experiments, as they may produce nuclear recoils that look exactly like WIMP interactions. In DarkSide-50, we both actively suppress and measure the rate of neutron-induced background events using our neutron veto, composed of a boron-loaded liquid scintillator detector within a water Cherenkov detector. This paper is devoted to the description of the neutron veto system of DarkSide-50, including the detector structure, the fundamentals of event reconstruction and data analysis, and basic performance parameters.

Published
2015
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28. Spatial and Temporal Patterns in Petrogenic Organic Carbon Mobilization During the Paleocene-Eocene Thermal Maximum

Author

Hollingsworth, E. H., Elling, F. J., Badger, M. P.S., Pancost, R. D., Dickson, A. J., Rees-Owen, R. L., Papadomanolaki, N. M., Pearson, A., Sluijs, A., Freeman, K. H., Baczynski, A. A., Foster, G. L., Whiteside, J. H., Inglis, G. N., Hollingsworth, E. H., Elling, F. J., Badger, M. P.S., Pancost, R. D., Dickson, A. J., Rees-Owen, R. L., Papadomanolaki, N. M., Pearson, A., Sluijs, A., Freeman, K. H., Baczynski, A. A., Foster, G. L., Whiteside, J. H., and Inglis, G. N.

Abstract

The Paleocene-Eocene Thermal Maximum (PETM) was a transient global warming event and is recognized in the geologic record by a prolonged negative carbon isotope excursion (CIE). The onset of the CIE was due to a rapid influx of 13C-depleted carbon into the ocean-atmosphere system. However, the mechanisms required to sustain the negative CIE remains unclear. Enhanced mobilization and oxidation of petrogenic organic carbon (OCpetro) has been invoked to explain elevated atmospheric carbon dioxide concentrations after the onset of the CIE. However, existing evidence is limited to the mid-latitudes and subtropics. Here, we determine whether: (a) enhanced mobilization and subsequent burial of OCpetro in marine sediments was a global phenomenon; and (b) whether it occurred throughout the PETM. To achieve this, we utilize a lipid biomarker approach to trace and quantify OCpetro burial in a global compilation of PETM-aged shallow marine sites (n = 7, including five new sites). Our results confirm that OCpetro mass accumulation rates (MARs) increased within the subtropics and mid-latitudes during the PETM, consistent with evidence of higher physical erosion rates and intense episodic rainfall events. High-latitude sites do not exhibit drastic changes in the source of organic carbon during the PETM and OCpetro MARs increase slightly or remain stable, perhaps due a more stable hydrological regime. Crucially, we also demonstrate that OCpetro MARs remained elevated during the recovery phase of the PETM. Although OCpetro oxidation was likely an important positive feedback mechanism throughout the PETM, we show that this feedback was both spatially and temporally variable.

Published
2024

29. Unintended consequences of school accountability reforms: Public versus private schools

Author

Coelli, M, Foster, G, Coelli, M, and Foster, G

Abstract

In this paper, we show that the public provision of information on Australian schools’ average national test score outcomes via the My School website, launched in 2010, resulted in poorly performing schools testing fewer students in subsequent years. This increased non-participation in testing was driven primarily by formal parental withdrawal, and poorly performing students were much more likely to be withdrawn from testing. This phenomenon is consistent with schools attempting to ‘game’ the system to improve published test scores. We also provide weaker evidence that withdrawal responded more strongly to initial poor performance in independent private schools than in government schools.

Published
2024

30. Spatial and Temporal Patterns in Petrogenic Organic Carbon Mobilization During the Paleocene-Eocene Thermal Maximum

Author

IVAU: Instituut voor Aardwetenschappen Utrecht, Geochemistry, Marine palynology and palaeoceanography, Hollingsworth, E. H., Elling, F. J., Badger, M. P.S., Pancost, R. D., Dickson, A. J., Rees-Owen, R. L., Papadomanolaki, N. M., Pearson, A., Sluijs, A., Freeman, K. H., Baczynski, A. A., Foster, G. L., Whiteside, J. H., Inglis, G. N., IVAU: Instituut voor Aardwetenschappen Utrecht, Geochemistry, Marine palynology and palaeoceanography, Hollingsworth, E. H., Elling, F. J., Badger, M. P.S., Pancost, R. D., Dickson, A. J., Rees-Owen, R. L., Papadomanolaki, N. M., Pearson, A., Sluijs, A., Freeman, K. H., Baczynski, A. A., Foster, G. L., Whiteside, J. H., and Inglis, G. N.

Published
2024

32. Direct-acting antiviral therapies for hepatitis C infection: global registration, reimbursement, and restrictions

Author

Marshall, Alison D, primary, Willing, Alex R, additional, Kairouz, Abe, additional, Cunningham, Evan B, additional, Wheeler, Alice, additional, O’Brien, Nicholas, additional, Perera, Vidura, additional, Ward, John W, additional, Hiebert, Lindsey, additional, Degenhardt, Louisa, additional, Hajarizadeh, Behzad, additional, Colledge, Samantha, additional, Hickman, Matthew, additional, Jawad, Danielle, additional, Lazarus, Jeffrey V, additional, Matthews, Gail V, additional, Scheibe, Andrew, additional, Vickerman, Peter, additional, Dore, Gregory J, additional, Grebely, Jason, additional, Sargsyants, N., additional, Suleymanova, L., additional, Salkic, N., additional, Simonova, M., additional, Nemeth-Blazic, T., additional, Mravcik, V., additional, Kivimets, K., additional, Salupere, R., additional, Butsashvili, M., additional, Soselia, G., additional, Makara, M., additional, Tolmane, I., additional, Jancorienė, L., additional, Stratulat, S., additional, Flisiak, R., additional, Gheorghe, L., additional, Cernat, R., additional, Lakhov, A., additional, Stanevich, O., additional, Jarcuska, P., additional, Peck-Radosavljevic, M., additional, Robaeys, G., additional, Øvrehus, A., additional, Foster, G., additional, Sutinen, J., additional, Farkkila, M., additional, Rautiainen, H., additional, Vuoti, S., additional, Nikolova, D., additional, Pawlotsky, J.M., additional, Rockstroh, J., additional, Sypsa, V., additional, Papatheodoridis, G., additional, Olafsson, S., additional, Feeney, E., additional, Teti, E., additional, Seguin-Devaux, C., additional, Pocock, J., additional, Reiff, S., additional, McDougall, N., additional, Van der Valk, M., additional, Dalgard, O., additional, Tato Marinho, R., additional, Dillon, J., additional, Peters, E., additional, Bojovic, K., additional, Matičič, M., additional, Kåberg, M., additional, Bruggmann, P., additional, Healy, B., additional, Chong, V.H., additional, Yi, S., additional, Tucker, J., additional, Pasaribu, L.R., additional, Tanaka, J., additional, Ashley, E.A., additional, Abu Hassan, M.R., additional, Mohammed, N.S., additional, Chan, H.K., additional, Gidaagaya, S., additional, Kyi, K.P., additional, Hyung Joon, K., additional, Chin, B., additional, Baladjay, P.C., additional, Kao, J.H., additional, Wansom, T., additional, da Cruz, B., additional, Flower, B., additional, Ehsan, E., additional, Al Mahtab, M., additional, Khandu, L., additional, Bhadoria, A.S., additional, Alavi, M., additional, KC, P., additional, Hamid, S., additional, Biryukov, S., additional, Alymbaeva, D., additional, Alaei, A., additional, Bakieva, S., additional, Flichman, D., additional, Carmo, R.F., additional, Valdez, E., additional, Cortes, C.P., additional, Contreras, F., additional, Teran, E., additional, Velez-Moller, P., additional, Jagnarine, T., additional, Mills, M., additional, Goodman-Meza, D., additional, Sánchez, J., additional, Montenegro-Idrogo, J.J., additional, Lugo Canales, A.M., additional, Davy, J., additional, Alexander, A., additional, Gerona, S., additional, Perazzo, R., additional, Balak, D., additional, Kelly-Hanku, A., additional, Fineanganofo, A., additional, Gane, E., additional, Raymond, N., additional, Debzi, N., additional, Sridharan, K., additional, Waked, I., additional, Turner, D., additional, Shibolet, O., additional, Al Muzaini, A., additional, El Nakib, M., additional, Sheriff, D.S., additional, Brahni, T., additional, Essayagh, T., additional, Essayagh, S., additional, Hjaija, D., additional, Al-Naamani, K., additional, Sanai, F.M., additional, Pasquale, H., additional, Bedri, S., additional, Chakroun, M., additional, Ghrabi, A., additional, Akarca, U.S., additional, Falcao, V., additional, Edmond Gbedo, S., additional, Ouoba, S., additional, Nyabenda, F., additional, Rocher Mbella, M., additional, Mahamat Moussa, A., additional, Youssouf, T., additional, Boniface, Y., additional, Akilimali Shindano, T., additional, Hamida, M.E., additional, Mongo, A., additional, Mapapa, C., additional, Desalegn, H., additional, Embinga, E.L.A., additional, Ndow, G., additional, Nartey, Y., additional, Cisse, M., additional, Djalo, M.A., additional, Mugambi, M., additional, Nyakowa, M., additional, Jeuronlon, M.K., additional, Ngoma, J., additional, Manitrala Ramanampamonjy, R., additional, Naik, K., additional, Soyjaudah, M.D., additional, Filipe, E., additional, Nnakelu, E., additional, Serumondo, J., additional, Mbodj, M., additional, Patino, M., additional, Aalto, M.K., additional, Waweru, P., additional, Dagnra, A., additional, Ocama, P., additional, Maghimbi, A., additional, Hamooya, B.M., additional, Katsidzira, L., additional, Rios, C., additional, Thormann, M., additional, Al Marzooqi, N., additional, Al Rand, H.M., additional, Francois, K., additional, Hamoudi, W., additional, Alkharty, M., additional, Skripo, O., additional, and Uka, T., additional

Published
2024
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33. Spatial and Temporal Patterns in Petrogenic Organic Carbon Mobilization During the Paleocene‐Eocene Thermal Maximum

Author

Hollingsworth, E. H., primary, Elling, F. J., additional, Badger, M. P. S., additional, Pancost, R. D., additional, Dickson, A. J., additional, Rees‐Owen, R. L., additional, Papadomanolaki, N. M., additional, Pearson, A., additional, Sluijs, A., additional, Freeman, K. H., additional, Baczynski, A. A., additional, Foster, G. L., additional, Whiteside, J. H., additional, and Inglis, G. N., additional

Published
2024
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35. The adjusted prevalence of hepatitis delta virus (HDV) in 25 countries and territories

Author

Razavi-Shearer, D., primary, Child, H., additional, Razavi-Shearer, K., additional, Voeller, A., additional, Razavi, H., additional, Buti, M., additional, Tacke, F., additional, Terrault, N., additional, Zeuzem, S., additional, Abbas, Z., additional, Aghemo, A., additional, Akarca, U.S., additional, Al Masri, N., additional, Alalwan, A., additional, Blomé, M Alanko, additional, Jerkeman, A., additional, Aleman, S., additional, Kamal, H., additional, Alghamdi, A., additional, Alghamdi, M., additional, Alghamdi, S., additional, Al-Hamoudi, W., additional, Ali, E., additional, Aljumah, A., additional, Altraif, I., additional, Amarsanaa, J., additional, Asselah, T., additional, Baatarkhuu, O., additional, Babameto, A., additional, Ben-Ari, Z., additional, Berg, T., additional, Biondi, M., additional, Braga, W., additional, Brandão-Mello, C., additional, Brown, R., additional, Brunetto, M., additional, Cabezas, J., additional, Cardoso, M., additional, Martins, A., additional, Chan, H.L.Y., additional, Cheinquer, H., additional, Chen, C.-J., additional, Yang, H.-I., additional, Chen, P.-J., additional, Chien, C.-H., additional, Chuang, W.-L., additional, Garza, L Cisneros, additional, Coco, B., additional, Coffin, C., additional, Coppola, N., additional, Cornberg, M., additional, Craxi, A., additional, Crespo, J., additional, Cuko, L., additional, De Ledinghen, V., additional, Duberg, A.-S., additional, Etzion, O., additional, Ferraz, M.L., additional, Ferreira, P., additional, Forns, X., additional, Foster, G., additional, Fung, J., additional, Gaeta, G., additional, García-Samaniego, J., additional, Genov, J., additional, Gheorghe, L., additional, Gholam, P., additional, Gish, R., additional, Glenn, J., additional, Hamid, S., additional, Hercun, J., additional, Hsu, Y.-C., additional, Hu, C.-C., additional, Huang, J.-F., additional, Idilman, R., additional, Jafri, W., additional, Janjua, N., additional, Jelev, D., additional, Jia, J., additional, Kåberg, M., additional, Kaita, K., additional, Kao, J.-H., additional, Khan, A., additional, Kim, D.Y., additional, Kondili, L., additional, Lagging, M., additional, Lampertico, P., additional, Lázaro, P., additional, Lazarus, J.V., additional, Lee, M.-H., additional, Lim, Y.-S., additional, Lobato, C., additional, Macedo, G., additional, Marinho, R., additional, Marotta, P., additional, Mendes-Correa, M.C., additional, Méndez-Sánchez, N., additional, Navas, M.-C., additional, Ning, Q., additional, Örmeci, N., additional, Orrego, M., additional, Osiowy, C., additional, Pan, C., additional, Pessoa, M., additional, Piracha, Z., additional, Pop, C., additional, Qureshi, H., additional, Raimondo, G., additional, Ramji, A., additional, Ribeiro, S., additional, Ríos-Hincapié, C., additional, Rodríguez, M., additional, Rosenberg, W., additional, Roulot, D., additional, Ryder, S., additional, Saeed, U., additional, Safadi, R., additional, Shouval, D., additional, Sanai, F., additional, Sanchez-Avila, J.F., additional, Santantonio, T., additional, Sarrazin, C., additional, Seto, W.-K., additional, Simonova, M., additional, Tanaka, J., additional, Tergast, T., additional, Tsendsuren, O., additional, Valente, C., additional, Villalobos-Salcedo, J.M., additional, Waheed, Y., additional, Wong, G., additional, Wong, V., additional, Yip, T., additional, Wu, J.-C., additional, Yu, M.-L., additional, Yuen, M.-F., additional, Yurdaydin, C., additional, and Zuckerman, E., additional

Published
2023
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38. Emergence of cabbage root flies from puparia collected throughout northern Europe

Author

Finch, S., primary, Bromand, B., additional, Brunel, E., additional, Bues, M., additional, Collier, R.H., additional, Dunne, R., additional, Foster, G., additional, Freuler, J., additional, Hommes, M., additional, Van Keymeulen, M., additional, Mowat, D.J., additional, Pelerents, C., additional, Skinner, G., additional, Städler, E., additional, and Theunissen, J., additional

Published
2020
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39. A Search for SS Cyg Outburst Predictors

Author

Price, A., Henden, A. A., Foster, G., Petriew, V., Huziak, R., James, R., Koppelman, M. D., Blackwell, J., Boyd, D., Brady, S., Cook, Lewis M., Crawford, T., Dillon, B., Gary, B. L., Goff, B., Graham, K., Holland, K., Jones, J., Miles, R., Starkey, D., Robinson, S., Vanmunster, T., and Walker, G.

Subjects
Astrophysics
Abstract

We report null results on a two year photometric search for outburst predictors in SS Cyg. Observations in Johnson V and Cousins I were obtained almost daily for multiple hours per night for two observing seasons. The accumulated data are put through various statistical and visual analysis techniques but fails to detect any outburst predictors. However, analysis of 102 years of AAVSO archival visual data led to the detection of a correlation between a long term quasi-periodic feature at around 1,000-2,000 days in length and an increase in outburst rate., Comment: Accepted in PASP, December 2007

Published
2007

40. Search for First-Generation Scalar Leptoquarks in $\bm{p \bar{p}}$ collisions at $\sqrt{s}$=1.96 TeV

Author

The CDF Collaboration, Acosta, D., 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., Arisawa, T., Arguin, J-F., Artikov, A., Ashmanskas, W., Attal, A., Azfar, F., Azzi-Bacchetta, P., Bacchetta, N., Bachacou, H., Badgett, W., Barbaro-Galtieri, A., Barker, G. J., Barnes, V. E., Barnett, B. A., Baroiant, S., Bauer, G., Bedeschi, F., Behari, S., Belforte, S., Bellettini, G., Bellinger, J., Belloni, A., Ben-Haim, E., Benjamin, D., Beretvas, A., Berry, T., Bhatti, A., Binkley, M., Bisello, D., Bishai, M., Blair, R. E., Blocker, C., Bloom, K., Blumenfeld, B., Bocci, A., Bodek, A., Bolla, G., Bolshov, A., Bortoletto, D., Boudreau, J., Bourov, S., Brau, B., Bromberg, C., Brubaker, E., Budagov, J., Budd, H. S., Burkett, K., Busetto, G., Bussey, P., Byrum, K. L., Cabrera, S., Campanelli, M., Campbell, M., Canelli, F., Canepa, A., Casarsa, M., Carlsmith, D., Carosi, R., Carron, S., Cavalli-Sforza, M., Castro, A., Catastini, P., Cauz, D., Cerri, A., Cerrito, L., Chapman, J., Chen, Y. C., Chertok, M., Chiarelli, G., Chlachidze, G., Chlebana, F., Cho, I., Cho, K., Chokheli, D., Chou, J. P., Chuang, S., Chung, K., Chung, W-H., Chung, Y. S., Cijliak, M., Ciobanu, C. I., Ciocci, M. A., Clark, A. G., Clark, D., Coca, M., Connolly, A., Convery, M., Conway, J., Cooper, B., Copic, K., Cordelli, M., Cortiana, G., Cranshaw, J., Cuevas, J., Cruz, A., Culbertson, R., Currat, C., Cyr, D., Dagenhart, D., DaRonco, S., D'Auria, S., deBarbaro, P., DeCecco, S., Deisher, A., DeLentdecker, G., Dell'Orso, M., Demers, S., Demortier, L., Deninno, M., DePedis, D., Derwent, P. F., Devlin, T., Dionisi, C., Dittmann, J. R., DiTuro, P., Dörr, C., Dominguez, A., Donati, S., Donega, M., Donini, J., D'Onofrio, M., Dorigo, T., Ebina, K., Efron, J., Ehlers, J., Erbacher, R., Erdmann, M., 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. D., Flanagan, G., Flores-Castillo, L. R., Foland, A., Forrester, S., Foster, G. W., Franklin, M., Freeman, J. C., Fujii, Y., Furic, I., Gajjar, A., Gallinaro, M., Galyardt, J., Garcia-Sciveres, M., Garfinkel, A. F., Gay, C., Gerberich, H., Gerdes, D. W., Gerchtein, E., Giagu, S., Giannetti, P., Gibson, A., Gibson, K., Ginsburg, C., Giolo, K., Giordani, M., Giunta, M., Giurgiu, G., Glagolev, V., Glenzinski, D., Gold, M., Goldschmidt, N., Goldstein, D., Goldstein, J., Gomez, G., Gomez-Ceballos, G., Goncharov, M., González, O., Gorelov, I., Goshaw, A. T., Gotra, Y., Goulianos, K., Gresele, A., Griffiths, M., Grosso-Pilcher, C., Grundler, U., GuimaraesdaCosta, J., Haber, C., Hahn, K., Hahn, S. R., Halkiadakis, E., Hamilton, A., Han, B-Y., Handler, R., Happacher, F., Hara, K., Hare, M., Harr, R. F., Harris, R. M., Hartmann, F., Hatakeyama, K., Hauser, J., Hays, C., Hayward, H., Heinemann, B., Heinrich, J., Hennecke, M., Herndon, M., Hill, C., Hirschbuehl, D., Hocker, A., Hoffman, K. D., Holloway, A., Hou, S., Houlden, M. A., Huffman, B. T., Huang, Y., Hughes, R. E., Huston, J., Ikado, K., Incandela, J., Introzzi, G., Iori, M., Ishizawa, Y., Issever, C., Ivanov, A., Iwata, Y., Iyutin, B., James, E., Jang, D., Jayatilaka, B., Jeans, D., Jensen, H., Jeon, E. J., Jones, M., Joo, K. K., Jun, S. Y., Junk, T., Kamon, T., Kang, J., KaragozUnel, M., 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, M. S., Kim, S. B., Kim, S. H., Kim, Y. K., Kirby, M., Kirsch, L., Klimenko, S., Klute, M., Knuteson, B., Ko, B. R., Kobayashi, H., Kong, D. J., Kondo, K., Konigsberg, J., Kordas, K., Korn, A., Korytov, A., Kotwal, A. V., Kovalev, A., Kraus, J., Kravchenko, I., Kreymer, A., Kroll, J., Kruse, M., Krutelyov, V., Kuhlmann, S. E., Kwang, S., Laasanen, A. T., Lai, S., Lami, S., Lammel, S., Lancaster, M., Lander, R., Lannon, K., Lath, A., Latino, G., Lazzizzera, I., Lecci, C., LeCompte, T., Lee, J., Lee, S. W., Lefèvre, R., Leonardo, N., Leone, S., Levy, S., Lewis, J. D., Li, K., Lin, C., Lin, C. S., Lindgren, M., Lipeles, E., Liss, T. M., Lister, A., Litvintsev, D. O., Liu, T., Liu, Y., 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., MacQueen, D., Madrak, R., Maeshima, K., Maksimovic, P., Manca, G., Margaroli, F., Marginean, R., Marino, C., Martin, A., Martin, M., Martin, V., Martínez, M., Maruyama, T., Matsunaga, H., Mattson, M., Mazzanti, P., McFarland, K. S., McGivern, D., McIntyre, P. M., McNamara, P., McNulty, R., Mehta, A., Menzemer, S., Menzione, A., Merkel, P., Mesropian, C., Messina, A., Miao, T., Miladinovic, N., Miles, J., Miller, L., Miller, R., Miller, J. S., Mills, C., Miquel, R., Miscetti, S., Mitselmakher, G., Miyamoto, A., Moggi, N., Mohr, B., Moore, R., Morello, M., MovillaFernandez, P. A., Muelmenstaedt, J., Mukherjee, A., Mulhearn, M., Muller, T., Mumford, R., Munar, A., Murat, P., Nachtman, J., Nahn, S., Nakano, I., Napier, A., Napora, R., Naumov, D., Necula, V., Nielsen, J., Nelson, T., Neu, C., Neubauer, M. S., Nigmanov, T., Nodulman, L., Norniella, O., Ogawa, T., Oh, S. H., Oh, Y. D., Ohsugi, T., Okusawa, T., Oldeman, R., Orava, R., Orejudos, W., Osterberg, K., Pagliarone, C., Palencia, E., Paoletti, R., Papadimitriou, V., Paramonov, A. A., Pashapour, S., Patrick, J., Pauletta, G., Paulini, M., Paus, C., Pellett, D., Penzo, A., Phillips, T. J., Piacentino, G., Piedra, J., Pitts, K. T., Plager, C., Pondrom, L., Pope, G., Portell, X., Poukhov, O., Pounder, N., Prakoshyn, F., Pronko, A., Proudfoot, J., Ptohos, F., Punzi, G., Rademacker, J., Rahaman, M. A., Rakitine, A., Rappoccio, S., Ratnikov, F., Ray, H., Reisert, B., Rekovic, V., Renton, P., Rescigno, M., Rimondi, F., Rinnert, K., Ristori, L., Robertson, W. J., Robson, A., Rodrigo, T., Rolli, S., Roser, R., Rossin, R., Rott, C., Russ, J., Rusu, V., Ruiz, A., Ryan, D., Saarikko, H., Sabik, S., Safonov, A., Denis, R. St., Sakumoto, W. K., Salamanna, G., Saltzberg, D., Sanchez, C., Santi, L., Sarkar, S., Sato, K., Savard, P., Savoy-Navarro, A., 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., Semeria, F., Sexton-Kennedy, L., Sfiligoi, I., Shapiro, M. D., Shears, T., Shepard, P. F., Sherman, D., Shimojima, M., Shochet, M., Shon, Y., Shreyber, I., Sidoti, A., Sill, A., Sinervo, P., Sisakyan, A., Sjolin, J., Skiba, A., Slaughter, A. J., Sliwa, K., Smirnov, D., Smith, J. R., Snider, F. D., Snihur, R., Soderberg, M., Soha, A., Somalwar, S. V., Spalding, J., Spezziga, M., Spinella, F., Squillacioti, P., Stadie, H., Stanitzki, M., Stelzer, B., Stelzer-Chilton, O., Stentz, D., Strologas, J., Stuart, D., Suh, J. S., Sukhanov, A., Sumorok, K., Sun, H., Suzuki, T., Taffard, A., Tafirout, R., Takano, H., Takashima, R., Takeuchi, Y., Takikawa, K., Tanaka, M., Tanaka, R., Tanimoto, N., Tecchio, M., Teng, P. K., Terashi, K., Tesarek, R. J., Tether, S., Thom, J., Thompson, A. S., Thomson, E., Tipton, P., Tiwari, V., Tkaczyk, S., Toback, D., Tollefson, K., Tomura, T., Tonelli, D., Tönnesmann, M., Torre, S., Torretta, D., Tourneur, S., Trischuk, W., Tsuchiya, R., Tsuno, S., Tsybychev, D., Turini, N., Ukegawa, F., Unverhau, T., Uozumi, S., Usynin, D., Vacavant, L., Vaiciulis, A., Varganov, A., VejcikIII, S., Velev, G., Veszpremi, V., Veramendi, G., Vickey, T., Vidal, R., Vila, I., Vilar, R., Vollrath, I., Volobouev, I., vonderMey, M., Wagner, P., Wagner, R. G., Wagner, R. L., Wagner, W., Wallny, R., Walter, T., Wan, Z., Wang, M. J., Wang, S. M., Warburton, A., Ward, B., Waschke, S., Waters, D., Watts, T., Weber, M., WesterIII, W. C., Whitehouse, B., Whiteson, D., Wicklund, A. B., Wicklund, E., Williams, H. H., Wilson, P., Winer, B. L., Wittich, P., Wolbers, S., Wolfe, C., Wolter, M., Worcester, M., Worm, S., Wright, T., Wu, X., Würthwein, F., Wyatt, A., Yagil, A., Yamashita, T., Yamamoto, K., Yamaoka, J., Yang, C., Yang, U. K., Yao, W., Yeh, G. P., Yoh, J., Yorita, K., Yoshida, T., Yu, I., Yu, S., Yun, J. C., Zanello, L., Zanetti, A., Zaw, I., Zetti, F., Zhou, J., and Zucchelli, S.

Subjects
High Energy Physics - Experiment
Abstract

We report on a search for pair production of first-generation scalar leptoquarks ($LQ$) in $p \bar{p}$ collisions at $\sqrt{s}$=1.96 TeV using an integrated luminosity of 203 $pb^{-1}$ collected at the Fermilab Tevatron collider by the CDF experiment. We observe no evidence for $LQ$ production in the topologies arising from $LQ \bar{LQ} \to eqeq$ and $LQ \bar{LQ} \to eq \nu q$, and derive 95% C.L. upper limits on the $LQ$ production cross section. %as a function of $\beta$, where $\beta$ is the branching fraction for $LQ \to eq$. The results are combined with those obtained from a separately reported CDF search in the topology arising from $LQ\bar{LQ} \to \nu q \nu q$ and 95% C.L. lower limits on the LQ mass as a function of $\beta = BR(LQ \to eq) $ are derived. The limits are 236, 205 and 145 GeV/c$^2$ for $\beta$ = 1, $\beta$ = 0.5 and $\beta$ = 0.1, respectively., Comment: submitted to PRL

Published
2005
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41. Comparison of Three-jet Events in Proton-Antiproton Collisions at Center-of-mass Energy 1.8 TeV to Predictions from a Next-to-leading Order QCD Calculation

Author

Acosta, D., Affolder, T., Albrow, M. G., Ambrose, D., Amidei, D., Anikeev, K., Antos, J., Apollinari, G., Arisawa, T., Artikov, A., Ashmanskas, W., Azfar, F., Azzi-Bacchetta, P., Bacchetta, N., Bachacou, H., Badgett, W., Barbaro-Galtieri, A., Barnes, V. E., Barnett, B. A., Baroiant, S., Barone, M., Bauer, G., Bedeschi, F., Behari, S., Belforte, S., Bell, W. H., Bellettini, G., Bellinger, J., Benjamin, D., Beretvas, A., Bhatti, A., Binkley, M., Bisello, D., Bishai, M., Blair, R. E., Blocker, C., Bloom, K., Blumenfeld, B., Bocci, A., Bodek, A., Bolla, G., Bolshov, A., Bortoletto, D., Boudreau, J., Bromberg, C., Brubaker, E., Budagov, J., Budd, H. S., Burkett, K., Busetto, G., Byrum, K. L., Cabrera, S., Campbell, M., Carithers, W., Carlsmith, D., Castro, A., Cauz, D., Cerri, A., Cerrito, L., Chapman, J., Chen, C., Chen, Y. C., Chertok, M., Chiarelli, G., Chlachidze, G., Chlebana, F., Chu, M. L., Chung, J. Y., Chung, W. -H., Chung, Y. S., Ciobanu, C. I., Clark, A. G., Coca, M., Connolly, A., Convery, M., Conway, J., Cordelli, M., Cranshaw, J., Culbertson, R., Dagenhart, D., D'Auria, S., de Barbaro, P., De Cecco, S., Dell'Agnello, S., Dell'Orso, M., Demers, S., Demortier, L., Deninno, M., De Pedis, D., Derwent, P. F., Dionisi, C., Dittmann, J. R., Dominguez, A., Donati, S., D'Onofrio, M., Dorigo, T., Eddy, N., Erbacher, R., Errede, D., Errede, S., Eusebi, R., Farrington, S., Feild, R. G., Fernandez, J. P., Ferretti, C., Field, R. D., Fiori, I., Flaugher, B., Flores-Castillo, L. R., Foster, G. W., Franklin, M., Friedman, J., Furic, I., Gallinaro, M., Garfinkel, A. F., Gay, C., Gerdes, D. W., Gerstein, E., Giagu, S., Giannetti, P., Giolo, K., Giordani, M., Giromini, P., Glagolev, V., Glenzinski, D., Gold, M., Goldschmidt, N., Goldstein, J., Gomez, G., Goncharov, M., Gorelov, I., Goshaw, A. T., Gotra, Y., Goulianos, K., Gresele, A., Grosso-Pilcher, C., Guenther, M., da Costa, J. Guimaraes, Haber, C., Hahn, S. R., Halkiadakis, E., Handler, R., Happacher, F., Hara, K., Harris, R. M., Hartmann, F., Hatakeyama, K., Hauser, J., Heinrich, J., Hennecke, M., Herndon, M., Hill, C., Hocker, A., Hoffman, K. D., Hou, S., Huffman, B. T., Hughes, R., Huston, J., Issever, C., Incandela, J., Introzzi, G., Iori, M., Ivanov, A., Iwata, Y., Iyutin, B., James, E., Jones, M., Kamon, T., Kang, J., Unel, M. Karagoz, Kartal, S., Kasha, H., Kato, Y., Kennedy, R. D., Kephart, R., Kilminster, B., Kim, D. H., Kim, H. S., Kim, M. J., Kim, S. B., Kim, S. H., Kim, T. H., Kim, Y. K., Kirby, M., Kirsch, L., Klimenko, S., Koehn, P., Kondo, K., Konigsberg, J., Korn, A., Korytov, A., Kroll, J., Kruse, M., Krutelyov, V., Kuhlmann, S. E., Kuznetsova, N., Laasanen, A. T., Lami, S., Lammel, S., Lancaster, J., Lannon, K., Lancaster, M., Lander, R., Lath, A., Latino, G., LeCompte, T., Le, Y., Lee, J., Lee, S. W., Leonardo, N., Leone, S., Lewis, J. D., Li, K., Lin, C. S., Lindgren, M., Liss, T. M., Liu, T., Litvintsev, D. O., Lockyer, N. S., Loginov, A., Loreti, M., Lucchesi, D., Lukens, P., Lyons, L., Lys, J., Madrak, R., Maeshima, K., Maksimovic, P., Malferrari, L., Mangano, M., Manca, G., Mariotti, M., Martin, M., Martin, A., Martin, V., Martinez, M., Mazzanti, P., McFarland, K. S., McIntyre, P., Menguzzato, M., Menzione, A., Merkel, P., Mesropian, C., Meyer, A., Miao, T., Miller, R., Miller, J. S., Miscetti, S., Mitselmakher, G., Moggi, N., Moore, R., Moulik, T., Mulhearn, M., Mukherjee, A., Muller, T., Munar, A., Murat, P., Nachtman, J., Nahn, S., Nakano, I., Napora, R., Niell, F., Nelson, C., Nelson, T., Neu, C., Neubauer, M. S., Newman-Holmes, C., Nigmanov, T., Nodulman, L., Oh, S. H., Oh, Y. D., Ohsugi, T., Okusawa, T., Orejudos, W., Pagliarone, C., Palmonari, F., Paoletti, R., Papadimitriou, V., Patrick, J., Pauletta, G., Paulini, M., Pauly, T., Paus, C., Pellett, D., Penzo, A., Phillips, T. J., Piacentino, G., Piedra, J., Pitts, K. T., Pompos, A., Pondrom, L., Pope, G., Pratt, T., Prokoshin, F., Proudfoot, J., Ptohos, F., Poukhov, O., Punzi, G., Rademacker, J., Rakitine, A., Ratnikov, F., Ray, H., Reichold, A., Renton, P., Rescigno, M., Rimondi, F., Ristori, L., Robertson, W. J., Rodrigo, T., Rolli, S., Rosenson, L., Roser, R., Rossin, R., Rott, C., Roy, A., Ruiz, A., Ryan, D., Safonov, A., Denis, R. St., Sakumoto, W. K., Saltzberg, D., Sanchez, C., Sansoni, A., Santi, L., Sarkar, S., Savard, P., Savoy-Navarro, A., Schlabach, P., Schmidt, E. E., Schmidt, M. P., Schmitt, M., Scodellaro, L., Scribano, A., Sedov, A., Seidel, S., Seiya, Y., Semenov, A., Semeria, F., Shapiro, M. D., Shepard, P. F., Shibayama, T., Shimojima, M., Shochet, M., Sidoti, A., Sill, A., Sinervo, P., Slaughter, A. J., Sliwa, K., Snider, F. D., Snihur, R., Spezziga, M., Spinella, F., Spiropulu, M., Spiegel, L., Stefanini, A., Strologas, J., Stuart, D., Sukhanov, A., Sumorok, K., Suzuki, T., Takashima, R., Takikawa, K., Tanaka, M., Tecchio, M., Tesarek, R. J., Teng, P. K., Terashi, K., Tether, S., Thom, J., Thomas, T. L., Thompson, A. S., Thomson, E., Tipton, P., Tkaczyk, S., Toback, D., Tollefson, K., Tonelli, D., Toennesmann, M., Toyoda, H., Trischuk, W., Tseng, J., Tsybychev, D., Turini, N., Ukegawa, F., Unverhau, T., Vaiciulis, T., Varganov, A., Vataga, E., Vejcik III, S., Velev, G., Veramendi, G., Vidal, R., Vila, I., Vilar, R., Volobouev, I., von der Mey, M., Wagner, R. G., Wagner, R. L., Wagner, W., Wan, Z., Wang, C., Wang, M. J., Wang, S. M., Ward, B., Waschke, S., Waters, D., Watts, T., Weber, M., Wester III, W. C., Whitehouse, B., Wicklund, A. B., Wicklund, E., and Williams, H. H.

Subjects
High Energy Physics - Experiment
Abstract

The properties of three-jet events with total transverse energy greater than 320 GeV and individual jet energy greater than 20 GeV have been analyzed and compared to absolute predictions from a next-to-leading order (NLO) perturbative QCD calculation. These data, of integrated luminosity 86 pb^-1, were recorded by the CDF Experiment for proton-antiproton collisions at sqrt{s}=1.8 TeV. This study tests a model of higher order QCD processes that result in gluon emission and can be used to estimate the magnitude of the contribution of processes higher than NLO. The total cross section is measured to be 466 +/- 3(stat.)^{+207}_{-70}(syst.) pb. The differential cross section is furthermore measured for all kinematically accessible regions of the Dalitz plane, including those for which the theoretical prediction is unreliable. While the measured cross section is consistent with the theoretical prediction in magnitude, the two differ somewhat in shape in the Dalitz plane.

Published
2004
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43. Sensitive Absolute Gravity Gradiometry Using Atom Interferometry

Author

McGuirk, J. M., Foster, G. T., Fixler, J. B., Snadden, M. J., and Kasevich, M. A.

Subjects
Physics - Atomic Physics
Abstract

We report the demonstration of a sensitive absolute gravity gradiometer based on light-pulse atom interference techniques. The gradiometer consists of two absolute accelerometers operated in a differential mode. We report a differential acceleration sensitivity of 4e-9 g/Hz^(1/2) and an inferred differential acceleration accuracy of less than 1e-9 g. This corresponds to a gravity gradient sensitivity of 4 E/Hz^(1/2) [1 E = 1e-9 s^(-2)] and an accuracy of better than 1 E for a 10 m separation between accelerometers. We demonstrate that the instrument can be used to detect nearby masses in a vibrationally noisy environment and characterize instrument sensitivity to spurious acceleration and rotation noise., Comment: 15 pages, 11 figures zipped into one file, submitted to Phys. Rev. A

Published
2001
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44. The Variability of R,N,C Stars from HIPPARCOS and AAVSO Data

Author

Grenon, M., Mattei, J. A., Eyer, L., and Foster, G.

Subjects
Astrophysics
Abstract

Accurate photometry was obtained for all programme stars during the 3.3-year HIPPARCOS mission. The final observing programme included several hundred Mirae (M), semiregular (SR) long-period and irregular (L) variables. A detailed calibration of the aging of the optics allowed the evaluation of very precise magnitudes over the whole range of star colours. Since the time coverage of the satellite observations was not sufficient to describe the behaviour of M, SR, or L type variables, smooth curves were fitted statistically to the dense AAVSO observations. These curves were then transformed to the HIPPARCOS system in order to complement the HIPPARCOS photometry and thus produce precise light curves with fuller time coverage, for a set of several hundred late-type variables, including most Carbon stars brighter than V = 12.4 at minimum luminosity. A preliminary discussion of the behaviour of C stars, as observed from the space in the broad Hp band, is given., Comment: 8 pages, 6 figures, IAU Symposium 177, published in "The carbon star phenomenon", RF. Wing ed., Kluwer, 2000

Published
2001

45. Intracellular distribution and infection dynamics of virulent and attenuated Salmonella enterica serovar Typhimurium strains in vivo

Author

Foster, G. L.

Subjects
616.9
Abstract

I have demonstrated that the net growth rate of the virulent S. enterica serovar Typhimurium C5 strain can be increased by the presence of the attenuated aroA S. Typhimurium SL3261 vaccine strain in the same tissue. The growth acceleration is dependent upon the release of the immunosuppressive cytokine IL-10. This work illustrates that IL-10 production in response to S. enterica requires TLR4 and occurs via signalling pathways involving both TRIF and MyD88 adaptor molecules. Acceleration of the growth of C5 Salmonella does not require simultaneous co-injection of the attenuated bacteria. This indicates that intravenous administration of an S. enterica vaccine strain could potentially exacerbate an established infection with wild-type bacteria. These data could also suggest that the severity of an infection with a virulent S. enterica strain can be increased by the prior administration of a live attenuated vaccine strain. Secondly, the bacterial distribution of Salmonella enterica within host cells was investigated to try to understand the role of host and bacterial mechanisms in determining bacterial load per host cell. During infections of hosts lacking components of the innate immune system it was found that the bacteria had an increased net growth rate and increased numbers of bacteria per cell; this is in qualitative agreement with the current model of Salmonella in vivo distribution. Temperature sensitive SPI-1 and SPI-2 Salmonella mutants were used to examine the role of bacterial effectors and division in determining bacterial distribution within host cells. This thesis shows that temperature sensitive Salmonella that are unable to replicate at host body temperature reach lower bacterial numbers per host cell. The SPI-2 mutant exhibited a surprising distribution within the host, reaching very high bacterial loads in non-nucleated micro colonies. SPI-2 effectors may promote host cell lysis in vivo.

Published
2008

49. Mode switching in the nearby Mira-like variable R Doradus

Author

Bedding, T. R., Zijlstra, A. A., Jones, A., and Foster, G.

Subjects
Astrophysics
Abstract

We discuss visual observations spanning nearly 70 years of the nearby semiregular variable R Doradus. Using wavelet analysis, we show that the star switches back and forth between two pulsation modes having periods of 332 days and about 175 days, the latter with much smaller amplitude. Comparison with model calculations suggests that the two modes are the first and third radial overtone, with the physical diameter of the star making fundamental mode pulsation unlikely. The mode changes occur on a timescale of about 1000 d, which is too rapid be related to a change in the overall thermal structure of the star and may instead be related to weak chaos. The Hipparcos distance to R Dor is 62.4 +/- 2.8 pc which, taken with its dominant 332-day period, places it exactly on the period-luminosity relation of Miras in the Large Magellanic Cloud. Our results imply first overtone pulsation for all Miras which fall on the P-L relation. We argue that semiregular variables with long periods may largely be a subset of Miras and should be included in studies of Mira behaviour. The semiregulars may contain the immediate evolutionary Mira progenitors, or stars may alternate between periods of semiregular and Mira behaviour., Comment: 12 pages, latex with figures, accepted by MNRAS

Published
1998
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50. Long-term safety follow-up of an anterior chamber angle-supported phakic intraocular lens

Author

Demong, Thaddeus, Rabinovitch, Theodore, Pop, Mihai, Roy, Francis, Holland, Simon, Schweitzer, Cedric, Cochener, Beatrice, Malecaze, Francois, Schmickler, Stefani, Knorz, Michael, Bellucci, Roberto, Gomes, Miguel, Alió, Jorge, Kloess, Price M., Maxwell, Andrew, Salz, James J., Foster, G., Kraff, Colman, Stahl, Jason, Holland, Edward, Grosinger, Les D., Pepose, Jay, Lane, Stephen S., Wong, Michael Y., Schultze, Robert, Dupps, William, Nutaitis, Matthew, Thompson, Vance, Horn, Jeffrey, Whitsett, Jeffrey, Hu, Jerry, Lehmann, Robert, Vukich, John, Kohnen, Thomas, LaFontaine, Laura, and Andrew, Russell

Published
2017
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