Search

Your search keyword '"Wagner, S. M."' showing total 44 results
Start Over Author "Wagner, S. M."
44 results on '"Wagner, S. M."'

1. Flaring activity from magnetic reconnection in BL Lacertae

Author

Agarwal, S., Banerjee, B., Shukla, A., Roy, J., Acharya, S., Vaidya, B., Chitnis, V. R., Wagner, S. M., Mannheim, K., and Branchesi, M.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The evolution of the spectral energy distribution during flares constrains models of particle acceleration in blazar jets. The archetypical blazar BL Lac provided a unique opportunity to study spectral variations during an extended strong flaring episode from 2020-2021. During its brightest $\gamma$-ray state, the observed flux (0.1-300 GeV) reached up to $2.15\,\times\,10^{-5}\,\rm{ph\,cm^{-2}\,s^{-1}}$, with sub-hour scale variability. The synchrotron hump extended into the X-ray regime showing a minute-scale flare with an associated peak shift of inverse-Compton hump in gamma-rays. In shock acceleration models, a high Doppler factor value $>$100 is required to explain the observed rapid variability, change of state, and $\gamma$-ray peak shift. Assuming particle acceleration in mini-jets produced by magnetic reconnection during flares, on the other hand, alleviates the constraint on required bulk Doppler factor. In such jet-in-jet models, observed spectral shift to higher energies (towards TeV regime) and simultaneous rapid variability arises from the accidental alignment of a magnetic plasmoid with the direction of the line of sight. We infer a magnetic field of $\sim0.6\,\rm{G}$ in a reconnection region located at the edge of BLR ($\sim0.02\,\rm{pc}$). The scenario is further supported by log-normal flux distribution arising from merging of plasmoids in reconnection region., Comment: 6 pages, 3 figures, 1 table, Accepted for publication in MNRAS-L

Published
2023
Full Text
View/download PDF

2. Testing two-component models on very-high-energy gamma-ray emitting BL Lac objects

Author

MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Baack, D., Babić, A., Banerjee, B., de Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Espiñeira, E. Do Souto, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Fraga, B. Machado de Oliveira, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Nievas-Rosillo, M., Arcaro, C., Ammando, F. D', de Palma, F., Hodges, M., Hovatta, T., Kiehlmann, S., Max-Moerbeck, W., Readhead, A. C. S., Reeves, R., Takalo, L., Reinthal, R., Jormanainen, J., Wierda, F., Wagner, S. M., Berdyugin, A., Nabizadeh, A., Sheshvan, N. Talebpour, Oksanen, A., Bachev, R., Strigachev, A., and Kehusmaa, P.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Context. It has become evident that one-zone synchrotron self-Compton models are not always adequate for very-high-energy (VHE) gamma-ray emitting blazars. While two-component models are performing better, they are difficult to constrain due to the large number of free parameters. Aims. In this work, we make a first attempt to take into account the observational constraints from Very Long Baseline Interferometry (VLBI) data, long-term light curves (radio, optical, and X-rays) and optical polarisation to limit the parameter space for a two-component model and test if it can still reproduce the observed spectral energy distribution (SED) of the blazars. Methods. We selected five TeV BL Lac objects based on the availability of VHE gamma-ray and optical polarisation data. We collected constraints for the jet parameters from VLBI observations. We evaluated the contributions of the two components to the optical flux by means of decomposition of long-term radio and optical light curves as well as modeling of the optical polarisation variability of the objects. We selected eight epochs for these five objects, based on the variability observed at VHE gamma rays, for which we constructed the SEDs that we then modeled with a two-component model. Results. We found parameter sets which can reproduce the broadband SED of the sources in the framework of two-component models considering all available observational constraints from VLBI observations. Moreover, the constraints obtained from the long-term behavior of the sources in the lower energy bands could be used to determine the region where the emission in each band originates. Finally, we attempted to use optical polarisation data to shed new light on the behavior of the two components in the optical band. Our observationally constrained two zone model allows explanation of the entire SED from radio to VHE with two co-located emission regions.

Published
2020
Full Text
View/download PDF

6. Testing two-component models on very high-energy gamma-ray-emitting BL Lac objects

Author

Acciari, V. A. (V. A.), Ansoldi, S. (S.), Antonelli, L. A. (L. A.), Engels, A. A. (A. Arbet), Baack, D. (D.), Babic, A. (A.), Banerjee, B. (B.), de Almeida, U. B. (U. Barres), Barrio, J. A. (J. A.), Gonzalez, J. B. (J. Becerra), Bednarek, W. (W.), Bellizzi, L. (L.), Bernardini, E. (E.), Berti, A. (A.), Besenrieder, J. (J.), Bhattacharyya, W. (W.), Bigongiari, C. (C.), Biland, A. (A.), Blanch, O. (O.), Bonnoli, G. (G.), Bosnjak, Z. (Z.), Busetto, G. (G.), Carosi, R. (R.), Ceribella, G. (G.), Cerruti, M. (M.), Chai, Y. (Y.), Chilingarian, A. (A.), Cikota, S. (S.), Colak, S. M. (S. M.), Colin, U. (U.), Colombo, E. (E.), Contreras, J. L. (J. L.), Cortina, J. (J.), Covino, S. (S.), D'Amico, G. (G.), D'Elia, V. (V), Da Vela, P. (P.), Dazzi, F. (F.), De Angelis, A. (A.), De Lotto, B. (B.), Delfino, M. (M.), Delgado, J. (J.), Depaoli, D. (D.), Di Pierro, F. (F.), Di Venere, L. (L.), Espineira, E. D. (E. Do Souto), Prester, D. D. (D. Dominis), Donini, A. (A.), Dorner, D. (D.), Doro, M. (M.), Elsaesser, D. (D.), Ramazani, V. F. (V. Fallah), Fattorini, A. (A.), Ferrara, G. (G.), Foffano, L. (L.), Fonseca, M. V. (M., V), Font, L. (L.), Fruck, C. (C.), Fukami, S. (S.), Lopez, R. J. (R. J. Garcia), Garczarczyk, M. (M.), Gasparyan, S. (S.), Gaug, M. (M.), Giglietto, N. (N.), Giordano, F. (F.), Gliwny, P. (P.), Godinovic, N. (N.), Green, D. (D.), Hadasch, D. (D.), Hahn, A. (A.), Herrera, J. (J.), Hoang, J. (J.), Hrupec, D. (D.), Huetten, M. (M.), Inada, T. (T.), Inoue, S. (S.), Ishio, K. (K.), Iwamura, Y. (Y.), Jouvin, L. (L.), Kajiwara, Y. (Y.), Karjalainen, M. (M.), Kerszberg, D. (D.), Kobayashi, Y. (Y.), Kubo, H. (H.), Kushida, J. (J.), Lamastra, A. (A.), Lelas, D. (D.), Leone, F. (F.), Lindfors, E. (E.), Lombardi, S. (S.), Longo, F. (F.), Lopez, M. (M.), Lopez-Coto, R. (R.), Lopez-Oramas, A. (A.), Loporchio, S. (S.), Fraga, B. M. (B. Machado de Oliveira), Maggio, C. (C.), Majumdar, P. (P.), Makariev, M. (M.), Mallamaci, M. (M.), Maneva, G. (G.), Manganaro, M. (M.), Mannheim, K. (K.), Maraschi, L. (L.), Mariotti, M. (M.), Martinez, M. (M.), Mazin, D. (D.), Mender, S. (S.), Micanovic, S. (S.), Miceli, D. (D.), Miener, T. (T.), Minev, M. (M.), Miranda, J. M. (J. M.), Mirzoyan, R. (R.), Molina, E. (E.), Moralejo, A. (A.), Morcuende, D. (D.), Moreno, V. (V), Moretti, E. (E.), Munar-Adrover, P. (P.), Neustroev, V. (V), Nigro, C. (C.), Nilsson, K. (K.), Ninci, D. (D.), Nishijima, K. (K.), Noda, K. (K.), Nogues, L. (L.), Nozaki, S. (S.), Ohtani, Y. (Y.), Oka, T. (T.), Otero-Santos, J. (J.), Palatiello, M. (M.), Paneque, D. (D.), Paoletti, R. (R.), Paredes, J. M. (J. M.), Pavletic, L. (L.), Penil, P. (P.), Peresano, M. (M.), Persic, M. (M.), Moroni, P. G. (P. G. Prada), Prandini, E. (E.), Puljak, I. (I), Rhode, W. (W.), Ribo, M. (M.), Rico, J. (J.), Righi, C. (C.), Rugliancich, A. (A.), Saha, L. (L.), Sahakyan, N. (N.), Saito, T. (T.), Sakurai, S. (S.), Satalecka, K. (K.), Schleicher, B. (B.), Schmidt, K. (K.), Schweizer, T. (T.), Sitarek, J. (J.), Snidaric, I. (I), Sobczynska, D. (D.), Spolon, A. (A.), Stamerra, A. (A.), Strom, D. (D.), Strzys, M. (M.), Suda, Y. (Y.), Suric, T. (T.), Takahashi, M. (M.), Tavecchio, F. (F.), Temnikov, P. (P.), Terzic, T. (T.), Teshima, M. (M.), Torres-Alba, N. (N.), Tosti, L. (L.), van Scherpenberg, J. (J.), Vanzo, G. (G.), Acosta, M. V. (M. Vazquez), Ventura, S. (S.), Verguilov, V. (V.), Vigorito, C. F. (C. F.), Vitale, V. (V.), Vovk, I. (I), Will, M. (M.), Zaric, D. (D.), Nievas-Rosillo, M. (M.), Arcaro, C. (C.), D'Ammando, F. (F.), de Palma, F. (F.), Hodges, M. (M.), Hovatta, T. (T.), Kiehlmann, S. (S.), Max-Moerbeck, W. (W.), Readhead, A. C. (A. C. S.), Reeves, R. (R.), Takalo, L. (L.), Reinthal, R. (R.), Jormanainen, J. (J.), Wierda, F. (F.), Wagner, S. M. (S. M.), Berdyugin, A. (A.), Nabizadeh, A. (A.), Sheshvan, N. T. (N. Talebpour), Oksanen, A. (A.), Bachev, R. (R.), Strigachev, A. (A.), Kehusmaa, P. (P.), Acciari, V. A. (V. A.), Ansoldi, S. (S.), Antonelli, L. A. (L. A.), Engels, A. A. (A. Arbet), Baack, D. (D.), Babic, A. (A.), Banerjee, B. (B.), de Almeida, U. B. (U. Barres), Barrio, J. A. (J. A.), Gonzalez, J. B. (J. Becerra), Bednarek, W. (W.), Bellizzi, L. (L.), Bernardini, E. (E.), Berti, A. (A.), Besenrieder, J. (J.), Bhattacharyya, W. (W.), Bigongiari, C. (C.), Biland, A. (A.), Blanch, O. (O.), Bonnoli, G. (G.), Bosnjak, Z. (Z.), Busetto, G. (G.), Carosi, R. (R.), Ceribella, G. (G.), Cerruti, M. (M.), Chai, Y. (Y.), Chilingarian, A. (A.), Cikota, S. (S.), Colak, S. M. (S. M.), Colin, U. (U.), Colombo, E. (E.), Contreras, J. L. (J. L.), Cortina, J. (J.), Covino, S. (S.), D'Amico, G. (G.), D'Elia, V. (V), Da Vela, P. (P.), Dazzi, F. (F.), De Angelis, A. (A.), De Lotto, B. (B.), Delfino, M. (M.), Delgado, J. (J.), Depaoli, D. (D.), Di Pierro, F. (F.), Di Venere, L. (L.), Espineira, E. D. (E. Do Souto), Prester, D. D. (D. Dominis), Donini, A. (A.), Dorner, D. (D.), Doro, M. (M.), Elsaesser, D. (D.), Ramazani, V. F. (V. Fallah), Fattorini, A. (A.), Ferrara, G. (G.), Foffano, L. (L.), Fonseca, M. V. (M., V), Font, L. (L.), Fruck, C. (C.), Fukami, S. (S.), Lopez, R. J. (R. J. Garcia), Garczarczyk, M. (M.), Gasparyan, S. (S.), Gaug, M. (M.), Giglietto, N. (N.), Giordano, F. (F.), Gliwny, P. (P.), Godinovic, N. (N.), Green, D. (D.), Hadasch, D. (D.), Hahn, A. (A.), Herrera, J. (J.), Hoang, J. (J.), Hrupec, D. (D.), Huetten, M. (M.), Inada, T. (T.), Inoue, S. (S.), Ishio, K. (K.), Iwamura, Y. (Y.), Jouvin, L. (L.), Kajiwara, Y. (Y.), Karjalainen, M. (M.), Kerszberg, D. (D.), Kobayashi, Y. (Y.), Kubo, H. (H.), Kushida, J. (J.), Lamastra, A. (A.), Lelas, D. (D.), Leone, F. (F.), Lindfors, E. (E.), Lombardi, S. (S.), Longo, F. (F.), Lopez, M. (M.), Lopez-Coto, R. (R.), Lopez-Oramas, A. (A.), Loporchio, S. (S.), Fraga, B. M. (B. Machado de Oliveira), Maggio, C. (C.), Majumdar, P. (P.), Makariev, M. (M.), Mallamaci, M. (M.), Maneva, G. (G.), Manganaro, M. (M.), Mannheim, K. (K.), Maraschi, L. (L.), Mariotti, M. (M.), Martinez, M. (M.), Mazin, D. (D.), Mender, S. (S.), Micanovic, S. (S.), Miceli, D. (D.), Miener, T. (T.), Minev, M. (M.), Miranda, J. M. (J. M.), Mirzoyan, R. (R.), Molina, E. (E.), Moralejo, A. (A.), Morcuende, D. (D.), Moreno, V. (V), Moretti, E. (E.), Munar-Adrover, P. (P.), Neustroev, V. (V), Nigro, C. (C.), Nilsson, K. (K.), Ninci, D. (D.), Nishijima, K. (K.), Noda, K. (K.), Nogues, L. (L.), Nozaki, S. (S.), Ohtani, Y. (Y.), Oka, T. (T.), Otero-Santos, J. (J.), Palatiello, M. (M.), Paneque, D. (D.), Paoletti, R. (R.), Paredes, J. M. (J. M.), Pavletic, L. (L.), Penil, P. (P.), Peresano, M. (M.), Persic, M. (M.), Moroni, P. G. (P. G. Prada), Prandini, E. (E.), Puljak, I. (I), Rhode, W. (W.), Ribo, M. (M.), Rico, J. (J.), Righi, C. (C.), Rugliancich, A. (A.), Saha, L. (L.), Sahakyan, N. (N.), Saito, T. (T.), Sakurai, S. (S.), Satalecka, K. (K.), Schleicher, B. (B.), Schmidt, K. (K.), Schweizer, T. (T.), Sitarek, J. (J.), Snidaric, I. (I), Sobczynska, D. (D.), Spolon, A. (A.), Stamerra, A. (A.), Strom, D. (D.), Strzys, M. (M.), Suda, Y. (Y.), Suric, T. (T.), Takahashi, M. (M.), Tavecchio, F. (F.), Temnikov, P. (P.), Terzic, T. (T.), Teshima, M. (M.), Torres-Alba, N. (N.), Tosti, L. (L.), van Scherpenberg, J. (J.), Vanzo, G. (G.), Acosta, M. V. (M. Vazquez), Ventura, S. (S.), Verguilov, V. (V.), Vigorito, C. F. (C. F.), Vitale, V. (V.), Vovk, I. (I), Will, M. (M.), Zaric, D. (D.), Nievas-Rosillo, M. (M.), Arcaro, C. (C.), D'Ammando, F. (F.), de Palma, F. (F.), Hodges, M. (M.), Hovatta, T. (T.), Kiehlmann, S. (S.), Max-Moerbeck, W. (W.), Readhead, A. C. (A. C. S.), Reeves, R. (R.), Takalo, L. (L.), Reinthal, R. (R.), Jormanainen, J. (J.), Wierda, F. (F.), Wagner, S. M. (S. M.), Berdyugin, A. (A.), Nabizadeh, A. (A.), Sheshvan, N. T. (N. Talebpour), Oksanen, A. (A.), Bachev, R. (R.), Strigachev, A. (A.), and Kehusmaa, P. (P.)

Abstract

Context: It has become evident that one-zone synchrotron self-Compton models are not always adequate for very high-energy (VHE) gamma-ray-emitting blazars. While two-component models perform better, they are difficult to constrain due to the large number of free parameters. Aims: In this work, we make a first attempt at taking into account the observational constraints from very long baseline interferometry (VLBI) data, long-term light curves (radio, optical, and X-rays), and optical polarisation to limit the parameter space for a two-component model and test whether or not it can still reproduce the observed spectral energy distribution (SED) of the blazars. Methods: We selected five TeV BL Lac objects based on the availability of VHE gamma-ray and optical polarisation data. We collected constraints for the jet parameters from VLBI observations. We evaluated the contributions of the two components to the optical flux by means of decomposition of long-term radio and optical light curves as well as modelling of the optical polarisation variability of the objects. We selected eight epochs for these five objects based on the variability observed at VHE gamma rays, for which we constructed the SEDs that we then modelled with a two-component model. Results: We found parameter sets which can reproduce the broadband SED of the sources in the framework of two-component models considering all available observational constraints from VLBI observations. Moreover, the constraints obtained from the long-term behaviour of the sources in the lower energy bands could be used to determine the region where the emission in each band originates. Finally, we attempt to use optical polarisation data to shed new light on the behaviour of the two components in the optical band. Our observationally constrained two-component model allows explanation of the entire SED from radio to VHE with two co-located emission regions.

Published
2020

8. Nutzenbewertung eines routinemäßigen Infektiositäts-Screenings vor elektiven orthopädischen Operationen

Author

Weber, P., Eberle, J., Schrimpf, F., Jansson, V., and Huber-Wagner, S.-M.

Subjects
ddc: 610, 610 Medical sciences, Medicine
Abstract

Fragestellung: Durch das Tragen von Schutzbrillen und Signalhandschuhen wird versucht bei der Operation eines bekannt infektiösen Patienten das Übertragungsrisiko für bestimmte Viren (HBV, HCV und HIV) durch eine Nadelstich- oder Schnittverletzung zu minimieren. In elektiven Fäch[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie; 75. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 97. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 52. Tagung des Berufsverbandes der Fachärzte für Orthopädie

Published
2011

10. Market Entry and Competitive Strategies in the German B2B Parcel Market

Author

Dietl, H M, Lang, M, Lutzenberger, M, Wagner, S M, University of Zurich, Crew, M A, Kleindorfer, P R, and Dietl, H M

Subjects
2000 General Economics, Econometrics and Finance, 10004 Department of Business Administration, 1400 General Business, Management and Accounting, 3300 General Social Sciences, 330 Economics
Published
2009

11. Trends und Chancen der Europäischen Automobilindustrie

Author

Boutellier, Roman, Wagner, Stephan M, Boutellier, R ( Roman ), Wagner, S M ( Stephan M ), Schulze, Anja; https://orcid.org/0000-0002-7693-2467, Boutellier, Roman, Wagner, Stephan M, Boutellier, R ( Roman ), Wagner, S M ( Stephan M ), and Schulze, Anja; https://orcid.org/0000-0002-7693-2467

Published
2011

12. Market Entry and Competitive Strategies in the German B2B Parcel Market

Author

Crew, M A, Kleindorfer, P R, Crew, M A ( M A ), Kleindorfer, P R ( P R ), Dietl, H M; https://orcid.org/0000-0003-3134-6891, Lang, M; https://orcid.org/0000-0002-6837-790X, Lutzenberger, M, Wagner, S M, Crew, M A, Kleindorfer, P R, Crew, M A ( M A ), Kleindorfer, P R ( P R ), Dietl, H M; https://orcid.org/0000-0003-3134-6891, Lang, M; https://orcid.org/0000-0002-6837-790X, Lutzenberger, M, and Wagner, S M

Published
2009

19. A case study-based analysis of spare parts management in the engineering industry.

Author

Wagner, S. M. and Lindemann, E.

Subjects
SUPPLY chains, INDUSTRIAL procurement, PHYSICAL distribution of goods, SUPPLY & demand, BUSINESS logistics, INDUSTRIAL management, PRODUCTION management (Manufacturing), PRODUCTION planning, PRODUCTION methods
Abstract

Eroding margins for primary products have redirected many firms' attention to the highly profitable spare parts business. These firms push for increased sales and more efficient spare parts supply chains. However, previous research in spare parts supply chain management has principally been limited to planning and operational aspects such as the determination of spare parts inventory levels and re-order policies. Taking the sellers' perspective in the supply chain, the primary objective of the case study research presented in this article is to better understand the problems that engineering companies encounter and approaches that they adopt in their spare parts supply chains. The initial proposition, that engineering companies need to, and are eager to, adopt supply chain management practices in their spare parts businesses in order to capture revenue and profit potential, is supported. Among the key areas for improvement are the formulation of spare parts strategies, a better understanding of the installed base, and top management support for the spare parts business. [ABSTRACT FROM AUTHOR]

Published
2008
Full Text
View/download PDF

20. Intraoperative endoscopic localization of jejunal angiodysplasia as a source of massive rectal bleeding.

Author

Steele, John, Cardwell, Robert, Wagner, Steven, Merrick, Hollis, Steele, J T, Cardwell, R J, Wagner, S M, and Merrick, H W

Abstract

Gastrointestinal bleeding from an unknown source presents a difficult diagnostic problem. Despite the number of diagnostic tests available, there are occasions when gastrointestinal bleeding requires operative intervention without preoperative localization of the bleeding site. This situation was encountered in the case described, in which a preoperative bleeding scan could only suggest that the small bowel in the left upper quadrant was the source of the bleeding. Intraoperative small-bowel endoscopy was important in confirming the diagnosis. [ABSTRACT FROM AUTHOR]

Published
1989
Full Text
View/download PDF

22. Testing two-component models on very-high-energy gamma-ray emitting BL Lac objects

Author

Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babić, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Z., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, Markus, Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Nievas-Rosillo, M., Arcaro, C., D' Ammando, F., De Palma, F., Hodges, M., Hovatta, T., Kiehlmann, S., Max-Moerbeck, W., Readhead, A. C. S., Reeves, R., Takalo, L., Reinthal, R., Jormanainen, J., Wierda, F., Wagner, S. M., Berdyugin, A., Nabizadeh, A., Talebpour Sheshvan, N., Oksanen, A., Bachev, R., Strigachev, A., and Kehusmaa, P.

Subjects
7. Clean energy
Abstract

Astronomy and astrophysics 640, A132 - (2020). doi:10.1051/0004-6361/202037811, Context. It has become evident that one-zone synchrotron self-Compton models are not always adequate for very-high-energy (VHE) gamma-ray emitting blazars. While two-component models are performing better, they are difficult to constrain due to the large number of free parameters. Aims. In this work, we make a first attempt to take into account the observational constraints from Very Long Baseline Interferometry (VLBI) data, long-term light curves (radio, optical, and X-rays) and optical polarisation to limit the parameter space for a two-component model and test if it can still reproduce the observed spectral energy distribution (SED) of the blazars. Methods. We selected five TeV BL Lac objects based on the availability of VHE gamma-ray and optical polarisation data. We collected constraints for the jet parameters from VLBI observations. We evaluated the contributions of the two components to the optical flux by means of decomposition of long-term radio and optical light curves as well as modeling of the optical polarisation variability of the objects. We selected eight epochs for these five objects, based on the variability observed at VHE gamma rays, for which we constructed the SEDs that we then modeled with a two-component model. Results. We found parameter sets which can reproduce the broadband SED of the sources in the framework of two-component models considering all available observational constraints from VLBI observations. Moreover, the constraints obtained from the long-term behavior of the sources in the lower energy bands could be used to determine the region where the emission in each band originates. Finally, we attempted to use optical polarisation data to shed new light on the behavior of the two components in the optical band. Our observationally constrained two zone model allows explanation of the entire SED from radio to VHE with two co-located emission regions., Published by EDP Sciences, Les Ulis

28. Testing two-component models on very high-energy gamma-ray-emitting BL Lac objects

Author

Razmik Mirzoyan, D. Ninci, Susumu Inoue, Dorota Sobczyńska, V. Verguilov, Chiara Righi, J. van Scherpenberg, I. Šnidarić, John Hoang, Y. Chai, Stefano Covino, A. Babić, F. Di Pierro, D. Strom, Jose Luis Contreras, Petar Temnikov, Elisa Bernardini, C. Arcaro, Y. Iwamura, Ž. Bošnjak, Juan Cortina, Andrei Berdyugin, Bernd Schleicher, L. Jouvin, M. Makariev, Massimo Persic, P. Peñil, Markus Garczarczyk, Antonio Stamerra, J. Becerra González, F. de Palma, A. Arbet Engels, F. Leone, B. Machado de Oliveira Fraga, L. Nogués, Juan Abel Barrio, Sebastian Kiehlmann, A. Rugliancich, Marina Manganaro, S. Ansoldi, J. Rico, Anthony C. S. Readhead, M. Palatiello, H. Kubo, M. Karjalainen, Vitaly Neustroev, Laura Maraschi, Pawel Gliwny, Tomohiro Inada, N. Godinović, Giacomo Bonnoli, L. Bellizzi, Narek Sahakyan, M. Vazquez Acosta, Nicola Giglietto, P. G. Prada Moroni, K. Mannheim, M. Takahashi, Luca Tosti, S. Loporchio, D. Dominis Prester, Miguel Nievas-rosillo, Francesco Giordano, U. Barres de Almeida, C. Nigro, Valerio D'Elia, J. Otero-Santos, M. I. Martínez, Francesco Dazzi, Simone Mender, Alessia Spolon, G. Maneva, D. Hadasch, Elina Lindfors, Konstancja Satalecka, Luca Foffano, R. J. García López, Jenni Jormanainen, Michele Doro, A. Hahn, Takeshi Oka, Rumen Bachev, Kyoshi Nishijima, Daniel Mazin, A. Berti, A. Donini, B. Banerjee, T. Schweizer, Kari Nilsson, K. Noda, Armin Nabizadeh, G. Busetto, Shunsuke Sakurai, Daniel Kerszberg, M. Will, S. Gasparyan, A. Lamastra, M. Delfino, P. Munar-Adrover, A. López-Oramas, V. Fallah Ramazani, Carlo Vigorito, L. Saha, M. Mariotti, Walter Max-Moerbeck, N. Torres-Albà, Sarah M. Wagner, David Paneque, A. Biland, F. D' Ammando, Anton Strigachev, J. Besenrieder, M. Hütten, I. Vovk, C. Maggio, Arto Oksanen, L. Pavletić, D. Elsaesser, Matteo Cerruti, S. Fukami, Christian Fruck, U. Colin, David A. Green, D. Lelas, Kazuma Ishio, V. A. Acciari, W. Bhattacharyya, Yosuke Kobayashi, A. Fattorini, R. Reinthal, D. Zarić, Seiya Nozaki, E. Do Souto Espiñeira, Tomislav Terzić, Y. Kajiwara, Julian Sitarek, A. De Angelis, D. Miceli, M. V. Fonseca, W. Rhode, Francesco Longo, S. Lombardi, B. De Lotto, Roberto Carosi, Elisa Prandini, Sofia Ventura, D. Morcuende, N. Talebpour Sheshvan, W. Bednarek, Saša Mićanović, M. Minev, Riccardo Paoletti, M. Teshima, S. M. Colak, Markus Gaug, M. Peresano, Yoshiki Ohtani, Jordi Delgado, J. Kushida, P. Kehusmaa, Oscar Blanch, Ashot Chilingarian, D. Dorner, L. A. Antonelli, L. O. Takalo, V. Moreno, Giacomo D'Amico, S. Cikota, Kevin Schmidt, Y. Suda, Talvikki Hovatta, Fabrizio Tavecchio, Rodrigo Reeves, Eduardo Colombo, Ll. Font, M. Hodges, G. Ferrara, Dario Hrupec, M. A. Lopez, G. Ceribella, J. M. Paredes, Ciro Bigongiari, M. Mallamaci, R. López-Coto, Abelardo Moralejo, E. Moretti, D. Depaoli, Edgar Molina, G. Vanzo, T. Saito, P. Majumdar, Jose Carlos Herrera, F. Wierda, M. Strzys, L. Di Venere, Vincenzo Vitale, Dominik Baack, Jose Miguel Miranda, Tjark Miener, T. Surić, P. Da Vela, M. Ribó, I. Puljak, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Baack, D., Babic, A., Banerjee, B., Barres De Almeida, U., Barrio, J. A., Becerra Gonzalez, J., Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bosnjak, A., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espineira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Garcia Lopez, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinovic, N., Green, D., Hadasch, D., Hahn, A., Herrera, J., Hoang, J., Hrupec, D., Hutten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., Lopez, M., Lopez-Coto, R., Lopez-Oramas, A., Loporchio, S., MacHado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martinez, M., Mazin, D., Mender, S., Micanovic, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogues, L., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletic, L., Penil, P., Peresano, M., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Rhode, W., Ribo, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Snidaric, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Suric, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzic, T., Teshima, M., Torres-Alba, N., Tosti, L., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zaric, D., Nievas-Rosillo, M., Arcaro, C., D' Ammando, F., De Palma, F., Hodges, M., Hovatta, T., Kiehlmann, S., Max-Moerbeck, W., Readhead, A. C. S., Reeves, R., Takalo, L., Reinthal, R., Jormanainen, J., Wierda, F., Wagner, S. M., Berdyugin, A., Nabizadeh, A., Talebpour Sheshvan, N., Oksanen, A., Bachev, R., Strigachev, A., Kehusmaa, P., 30588766 - Arcaro, Cornelia, Academy of Finland, Ministerio de Economía y Competitividad (España), Swiss National Science Foundation, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Japan Society for the Promotion of Science, Metsähovi Radio Observatory, Aalto-yliopisto, and Aalto University

Subjects
galaxies [Gamma rays], Astronomical databases: miscellaneous, BL Lacertae objects: general, Galaxies: Active, Galaxies: jets, Gamma rays: galaxies, Radiation mechanisms: non-Thermal, SHEATH POLARIZATION STRUCTURES, Astrophysics, Parameter space, galaxies: active, galaxies: jets, astronomical databases: miscellaneous, radiation mechanisms: non-thermal, gamma rays: galaxies, 01 natural sciences, jet [Galaxies], non-Thermal [Radiation mechanisms], 010303 astronomy & astrophysics, LACERTAE OBJECTS, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, TEV BLAZARS, CROSS-CORRELATIONS, galaxie [Gamma rays], 1ES 1959+650, Gamma ray, Active [Galaxies], miscellaneous [Astronomical databases], Spectral energy distribution, Física nuclear, RELATIVISTIC JETS, Astrophysics - High Energy Astrophysical Phenomena, ACTIVE GALACTIC NUCLEI, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, GeneralLiterature_MISCELLANEOUS, 0103 physical sciences, Very-long-baseline interferometry, Blazar, MULTIWAVELENGTH OBSERVATIONS, 010308 nuclear & particles physics, general [BL Lacertae objects], ComputingMilieux_PERSONALCOMPUTING, Astronomy and Astrophysics, Light curve, Space and Planetary Science, X-RAY, ddc:520, jets [Galaxies], miscellaneou [Astronomical databases], COMPLETE SAMPLE, Free parameter
Abstract

MAGIC Collaboration: et al., [Context]: It has become evident that one-zone synchrotron self-Compton models are not always adequate for very high-energy (VHE) gamma-ray-emitting blazars. While two-component models perform better, they are difficult to constrain due to the large number of free parameters., [Aims]: In this work, we make a first attempt at taking into account the observational constraints from very long baseline interferometry (VLBI) data, long-term light curves (radio, optical, and X-rays), and optical polarisation to limit the parameter space for a two-component model and test whether or not it can still reproduce the observed spectral energy distribution (SED) of the blazars., [Methods]: We selected five TeV BL Lac objects based on the availability of VHE gamma-ray and optical polarisation data. We collected constraints for the jet parameters from VLBI observations. We evaluated the contributions of the two components to the optical flux by means of decomposition of long-term radio and optical light curves as well as modelling of the optical polarisation variability of the objects. We selected eight epochs for these five objects based on the variability observed at VHE gamma rays, for which we constructed the SEDs that we then modelled with a two-component model., [Results]: We found parameter sets which can reproduce the broadband SED of the sources in the framework of two-component models considering all available observational constraints from VLBI observations. Moreover, the constraints obtained from the long-term behaviour of the sources in the lower energy bands could be used to determine the region where the emission in each band originates. Finally, we attempt to use optical polarisation data to shed new light on the behaviour of the two components in the optical band. Our observationally constrained two-component model allows explanation of the entire SED from radio to VHE with two co-located emission regions., VFR and EL were supported by Academy of Finland projects 317636 and 320045. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish MINECO (FPA2017-87859-P, FPA2017-85668-P, FPA2017-82729-C6-2-R, FPA2017-82729-C6-6-R, FPA2017-82729-C6-5-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2017-87055-C2-2-P, FPA2017-90566-REDC); the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-268/16.12.2019 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2016-0588 and SEV2015-0548, the Unidad de Excelencia “María de Maeztu” MDM-2014-0369 and the “la Caixa” Foundation (fellowship LCF/BQ/PI18/11630012), by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq and FAPERJ.

Published
2020

29. Ropeginterferon alfa-2b for the treatment of patients with polycythemia vera.

Author

Wagner SM, Melchardt T, and Greil R

Subjects
Humans, Hydroxyurea, Interferon alpha-2 administration & dosage, Interferon-alpha administration & dosage, Polyethylene Glycols administration & dosage, Recombinant Proteins administration & dosage, Recombinant Proteins therapeutic use, Interferon alpha-2 therapeutic use, Interferon-alpha therapeutic use, Polycythemia Vera drug therapy, Polyethylene Glycols therapeutic use
Abstract

Ropeginterferon alfa-2b is a novel mono-PEGylated alfa interferon. It is the first interferon approved for the treatment of patients with polycythemia vera (PV) and the first and only approved treatment for PV independent of previous hydroxyurea exposure. In contrast to other interferons, the drug has to be subcutaneously injected every 2 weeks only, with intervals of 4 weeks being possible after prolonged use. It is generally well tolerated and can lead to deep molecular responses. In this article, we provide a review of available preclinical and clinical data of ropeginterferon alfa-2b leading to its E.U. approval and give an outlook on future clinical trials involving this drug., (Copyright 2020 Clarivate Analytics.)

Published
2020
Full Text
View/download PDF

30. Diagnosis and pre-operative management of multiple injured patients with explorative laparotomy because of blunt abdominal trauma.

Author

Heyn J, Ladurner R, Ozimek A, Bürklein D, Huber-Wagner SM, Hallfeldt KK, and Mussack T

Subjects
Abdominal Injuries surgery, Adult, Emergency Medical Services, Humans, Middle Aged, Multiple Trauma diagnostic imaging, Multiple Trauma surgery, Predictive Value of Tests, Preoperative Care, Registries, Sensitivity and Specificity, Ultrasonography, Wounds, Nonpenetrating surgery, Abdominal Injuries diagnostic imaging, Laparotomy, Tomography, X-Ray Computed, Wounds, Nonpenetrating diagnostic imaging
Abstract

Introduction: In trauma patients, injury of solid abdominal organs secondary to blunt trauma is a major source of morbidity and mortality. Different diagnostic options such as FAST sonography or CT scan have been described., Methods: Our trauma registry was used to identify multiple injured patients with blunt abdominal trauma during 2001 to 2006. Patient demographics, diagnostic and operative findings, treatment, complications, length of stay and mortality were reviewed., Results: Of 438 multiple injured patients, 58 patients were diagnosed with blunt abdominal trauma. During examination, free fluid or organ injury could be seen in 72.4% during sonography and in 84.3% of the patients who received CT scan, giving a sensitivity of 92% for initial FAST Sonography. Nevertheless, CT scan showed a higher sensitivity in detecting bowel (84%) or mesenteric (75%) injuries, if compared to FAST. 30 (51.7%) of the 58 patients had to undergo laparotomy because of blunt abdominal trauma, giving a laparotomy rate of 6.8% because of blunt abdominal trauma in multiple injured patients., Conclusion: Sonography is the method of choice for initial screening and CT scan in detecting bowel or mesenteric injuries. A large intraperitoneal fluid accumulation during initial sonography in combination with unstable vital signs should lead to an immediate exploratory laparotomy.

Published
2008

34. [1-year follow-up of traumatic pacemaker electrodes].

Author

Wagner SM, Lawo T, Lang V, Barmeyer J, Bolz A, and Schaldach M

Subjects
Equipment Design, Follow-Up Studies, Fractals, Humans, Signal Processing, Computer-Assisted instrumentation, Telemetry instrumentation, Electrocardiography instrumentation, Electrodes, Implanted, Pacemaker, Artificial
Published
1998
Full Text
View/download PDF

35. Predicting rodent carcinogenicity from mutagenic potency measured in the Ames Salmonella assay.

Author

Fetterman BA, Kim BS, Margolin BH, Schildcrout JS, Smith MG, Wagner SM, and Zeiger E

Subjects
Animals, Humans, Mutagenicity Tests, Rodentia, Carcinogenicity Tests methods, Mutagens toxicity, Salmonella typhimurium genetics
Abstract

Many in vitro tests have been developed to identify chemicals that can damage cellular DNA or cause mutations, and secondarily to identify potential carcinogens. The test receiving by far the most use and attention has been the Salmonella (SAL) mutagenesis test developed by Ames and colleagues [(1973): Proc Natl Acad Sci USA 70:2281-2285; (1975): Mutat Res 31:347-364], because of its initial promise of high qualitative (YES/NO) predictivity for cancer in rodents and, by extension, in humans. In addition to the initial reports of high qualitative predictivity, there was also an early report by Meselson and Russell [in Hiatt HH et al (1977): "Origins of Human Cancer, Book C: Human Risk Assessment," pp 1473-1481] of a quantitative relationship between mutagenic potency measured in SAL and carcinogenic potency measured in rodents, for a small number of chemicals. However, other reports using larger numbers of chemicals have found only very weak correlations. The primary purpose of this study was to determine whether mutagenic potency, as measured in a number of different ways, could be used to improve predictivity of carcinogenicity, either qualitatively or quantitatively. To this end, eight measures of SAL mutagenic potency were used. This study firmly establishes that the predictive relationship between mutagenic potency in SAL and rodent carcinogenicity is, at best, weak. When predicting qualitative carcinogenicity, only qualitative mutagenicity is useful; none of the quantitative measures of potency considered improves the carcinogenicity prediction. In fact, when qualitative mutagenicity is forced out of the model, the quantitative measures are still not predictive of carcinogenicity. When predicting quantitative carcinogenicity, several possible methods were considered for summarizing potency over all experiments; however, in all cases, the relationship between mutagenic potency predictors and quantitative carcinogenicity is very weak.

Published
1997
Full Text
View/download PDF

36. A matter of semantics.

Author

Wagner SM

Subjects
Hospital Bed Capacity, 100 to 299, Humans, Semantics, Texas, United States, Diagnosis, Insurance, Insurance Claim Reporting, Patient Discharge economics
Published
1982

40. Effects of caffeine and coffee on fluid transport in the small intestine.

Author

Wagner SM, Mekhjian HS, Caldwell JH, and Thomas FB

Subjects
Adult, Biological Transport drug effects, Body Water metabolism, Female, Humans, Intestinal Absorption drug effects, Intestine, Small metabolism, Male, Sodium metabolism, Stimulation, Chemical, Caffeine pharmacology, Coffee, Intestine, Small drug effects
Abstract

Although caffeine is known to stimulate small intestinal water secretion in man, no available studies have examined the effect of coffee on small intestinal fluid transport. We have studied the effect of both coffee and caffeine on jejunal sodium and water transport by the triple lumen intestinal perfusion technique. Both caffeine and coffee solutions had equivalent caffeine concentrations, approximating the caffeine concentration in one cup of coffee. Control and coffee perfusion resulted in net absorption of 0.9 +/- 0.2 and 1.1 +/- 0.3 ml per min per 30 cm, respectively, whereas caffeine perfusion resulted in net water secretion of 2.4 +/- 0.4 ml per min per 30 cm (P less than 0.02). Net sodium absorption was observed with control and coffee solutions with a mean absorption of 190 +/- 32 and 184 +/- 40 muEq per min per 30 cm, respectively. Net sodium secretion of 334 +/- 25 muEq er min per 30 cm was observed during caffeine perfusion (P less than 0.02). We conclude that coffee perfusion has no significant effect on sodium and water transport in the jejunum in spite of the marked secretory effects of caffeine solutions. The results of this study yield further support to the suggestion that the effects of caffeine may not be similar to the effects of caffeine-containing compounds such as coffee.

Published
1978

41. Giving credit where money is due. How to get a charge out of patients.

Author

Wagner SM

Subjects
Income, United States, Accounting methods, Financial Management methods, Financial Management, Hospital methods, Patient Credit and Collection methods
Abstract

It took a while, but hospitals are finally catching on to what major retailers discovered more than 30 years ago: Americans love to charge. When presented with a bill for socks at Bloomingdale's or lunch at Lutece, they pull out the plastic. Now, many can do roughly the same thing when presented with a hospital bill for treatment of a herniated disk. To shore up financial reserves, reduce bad debt, and increase cash flow, hospitals are turning to revolving consumer credit plans to help patients pay the self-pay portions of their hospital bills. Consumers like it because it gives them an affordable monthly payment over a long term, a good credit report reference, and a means to satisfy the self-pay obligation in a dignified, responsible way. And it seems to be working. A study of a 43-hospital chain that used a revolving charge plan for patients for a 23-month period showed that finance charges to patients more than covered the cost of the program; bad debts for receivables financed were cut to 29 percent, a 44.2 percent reduction; and consumers accepted the program because it was familiar, legal, binding, and, most important, affordable.

Published
1989

42. Pancreatography after recovery from massive pancreatic necrosis.

Author

Howard JM and Wagner SM

Subjects
Acute Disease, Adipose Tissue pathology, Adult, Aged, Aged, 80 and over, Cholangiopancreatography, Endoscopic Retrograde, Debridement, Diagnosis, Differential, Female, Humans, Male, Middle Aged, Necrosis, Pancreatectomy, Pancreatic Ducts pathology, Pancreatitis diagnostic imaging, Pancreatitis surgery, Reoperation, Retroperitoneal Space, Time Factors, Pancreatic Ducts diagnostic imaging, Pancreatitis pathology
Abstract

Massive retroperitoneal necrosis may follow life-threatening acute pancreatitis. At delayed operation, the surgeon may not be able to delineate dead pancreas from dead adipose tissue. The question arises: has "gloved hand" debridement resulted in pancreatectomy? The histologists report only "necrotic debris, of uncertain origin." To obtain objective data, pancreatography was performed in 13 patients, 10 weeks to 23 months after onset of massive pancreatic necrosis. Each patient had required delayed laparotomy for debridement and external drainage at some earlier stage of their illness. Pancreatography was correlated with the clinical assessment of diabetes and steatorrhea. Except in specific cases involving internal fistulae, pancreatography has not been previously reported in such patients. The results demonstrate that the main pancreatic duct usually maintained its normal length and configuration. Necrosis or stricture of the main duct, if it occurred, was more likely to be followed by diabetes. Steatorrhea was clinically detected in a single patient only. The necrotic tissue, up to several kilograms in wet weight, is largely dead adipose tissue. The pancreas, especially its head, is resistant to necrosis, much more resistant than is the retroperitoneal fat.

Published
1989
Full Text
View/download PDF

43. Enhancement of filterability of sickle cells by cyanate: an effect independent of oxygen saturation.

Author

Wagner SM, Bishop J, Flanigan PW, Bromberg PA, and Balcerzak SP

Subjects
Adenosine Triphosphate biosynthesis, Anemia, Sickle Cell drug therapy, Anemia, Sickle Cell pathology, Cyanates therapeutic use, Diphosphoglyceric Acids biosynthesis, Erythrocytes analysis, Erythrocytes metabolism, Filtration, Hemoglobin, Sickle, Humans, Urea, Anemia, Sickle Cell blood, Cyanates pharmacology, Erythrocytes drug effects, Oxygen blood
Abstract

Filterability and morphology of cyanate-treated sickle cells were compared to those of untreated cells at equal oxygen saturations to determine whether carbamylation inhibited sickling by an effect other than by its alteration of the oxygen dissociation curve. Morphology of treated and untreated cells was not significantly different at all levels of oxygen saturation examined. Filterability, on the other hand, was improved significantly by carbamylation. This latter finding indicates that carbamylation enhances deformability of sickle cells by a mechanism(s) in addition to its effect on red cell oxygen saturation. This mechanism(s) may account for the clinical benefit of cyanate therapy with doses which do not significantly affect the oxygen dissociation curve.

Published
1975

Catalog

Books, media, physical & digital resources
See catalog results