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207 results on '"Whitley, K"'

1. Shock-Driven Periodic Variability in a Low-Mass-Ratio Supermassive Black Hole Binary

Author

Whitley, K., Kuznetsova, A., Gültekin, K., and Ruszkowski, M.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We investigate the time-varying electromagnetic emission of a low-mass-ratio supermassive black hole binary (SMBHB) embedded in a circumprimary disk, with a particular interest in variability of shocks driven by the binary. We perform a 2D, locally isothermal hydrodynamics simulation of a SMBHB with mass ratio $q=0.01$ and separation $a=100\;R_g$, using a physically self-consistent steady disk model. We estimate the electromagnetic variability from the system by monitoring accretion onto the secondary and using an artificial viscosity scheme to capture shocks and monitor the energy dissipated. The SMBHB produces a wide, eccentric gap in the disk, previously only observed for larger mass ratios, which we attribute to our disk model being much thinner ($H/R\approx0.01$ near the secondary) than is typical of previous works. The eccentric gap drives periodic accretion onto the secondary SMBH on a timescale matching the orbital period of the binary, $t_{\rm{bin}}\approx0.1\;\rm{yr}$, implying that the variable accretion regime of the SMBHB parameter space extends to lower mass ratios than previously established. Shocks driven by the binary are periodic, with a period matching the orbital period, and the shocks are correlated with the accretion rate, with peaks in the shock luminosity lagging peaks in the accretion rate by $0.43\;t_{\rm{bin}}$. We propose that the correlation of these quantities represents a useful identifier of SMBHB candidates, via observations of correlated variability in X-ray and UV monitoring of AGN, rather than single-waveband periodicity alone., Comment: 12 pages, 8 figures, accepted by MNRAS

Published
2023

2. Cardiovascular Outcomes in GRADE (Glycemia Reduction Approaches in Type 2 Diabetes: A Comparative Effectiveness Study)

Author

Green, Jennifer B., Everett, Brendan M., Ghosh, Alokananda, Younes, Naji, Krause-Steinrauf, Heidi, Barzilay, Joshua, Desouza, Cyrus, Inzucchi, Silvio E., Pokharel, Yashashwi, Schade, David, Scrymgeour, Alexandra, Tan, Meng H., Utzschneider, Kristina M., Mudaliar, Sunder, Crandall, J.P., McKee, M.D., Behringer-Massera, S., Brown-Friday, J., Xhori, E., Ballentine-Cargill, K., Duran, S., Estrella, H., Gonzalez de la Torre, S., Lukin, J., Phillips, L.S., Burgess, E., Olson, D., Rhee, M., Wilson, P., Raines, T.S., Boers, J., Costello, J., Maher-Albertelli, M., Mungara, R., Savoye, L., White, C.A., Gullett, C., Holloway, L., Morehead, F., Person, S., Sibymon, M., Tanukonda, S., Adams, C., Ross, A., Balasubramanyam, A., Gaba, R., Gonzalez Hattery, E., Ideozu, A., Jimenez, J., Montes, G., Wright, C., Hollander, P., Roe, E., Jackson, A., Smiley, A., Burt, P., Estrada, L., Chionh, K., Ismail-Beigi, F., Falck-Ytter, C., Sayyed Kassem, L., Sood, A., Tiktin, M., Kulow, T., Newman, C., Stancil, K.A., Cramer, B., Iacoboni, J., Kononets, M.V., Sanders, C., Tucker, L., Werner, A., Maxwell, A., McPhee, G., Patel, C., Colosimo, L., Krol, A., Goland, R., Pring, J., Alfano, L., Kringas, P., Hausheer, C., Tejada, J., Gumpel, K., Kirpitch, A., Schneier, H., AbouAssi, H., Chatterjee, R., Feinglos, M.N., English Jones, J., Khan, S.A., Kimpel, J.B., Zimmer, R.P., Furst, M., Satterwhite, B.M., Thacker, C.R., Evans Kreider, K., Mariash, C.N., Mather, K.J., Ismail, H.M., Lteif, A., Mullen, M., Hamilton, T., Patel, N., Riera, G., Jackson, M., Pirics, V., Aguillar, D., Howard, D., Hurt, S., Bergenstal, R., Carlson, A., Martens, T., Johnson, M., Hill, R., Hyatt, J., Jensen, C., Madden, M., Martin, D., Willis, H., Konerza, W., Yang, S., Kleeberger, K., Passi, R., Fortmann, S., Herson, M., Mularski, K., Glauber, H., Prihoda, J., Ash, B., Carlson, C., Ramey, P.A., Schield, E., Torgrimson-Ojerio, B., Arnold, K., Kauffman, B., Panos, E., Sahnow, S., Bays, K., Berame, K., Cook, J., Ghioni, D., Gluth, J., Schell, K., Criscola, J., Friason, C., Jones, S., Nazarov, S., Rassouli, N., Puttnam, R., Ojoawo, B., Nelson, R., Curtis, M., Hollis, B., Sanders-Jones, C., Stokes, K., El-Haqq, Z., Kolli, A., Tran, T., Wexler, D., Larkin, M.E., Meigs, J., Chambers, B., Dushkin, A., Rocchio, G., Yepes, M., Steiner, B., Dulin, H., Cayford, M., Chu, K., DeManbey, A., Hillard, M., Martin, K., Thangthaeng, N., Gurry, L., Kochis, R., Raymond, E., Ripley, V., Stevens, C., Park, J., Aroda, V., Ghazi, A., Magee, M., Ressing, A., Loveland, A., Hamm, M., Hurtado, M., Kuhn, A., Leger, J., Manandhar, L., Mwicigi, F., Sanchez, O., Young, T., Garg, R., Lagari-Libhaber, V., Florez, H.J., Valencia, W.M., Marks, J., Casula, S., Oropesa-Gonzalez, L., Hue, L., Cuadot, A., Nieto-Martinez, R., Riccio Veliz, A.K., Gutt, M., Kendal, Y.J., Veciana, B., Ahmann, A., Aby-Daniel, D., Joarder, F., Morimoto, V., Sprague, C., Yamashita, D., Cady, N., Rivera-Eschright, N., Kirchhoff, P., Morales Gomez, B., Adducci, J., Goncharova, A., Hox, S.H., Petrovitch, H., Matwichyna, M., Jenkins, V., Broadwater, L., Ishii, R.R., Bermudez, N.O., Hsia, D.S., Cefalu, W.T., Greenway, F.L., Waguespack, C., King, E., Fry, G., Dragg, A., Gildersleeve, B., Arceneaux, J., Haynes, N., Thomassie, A., Pavlionis, M., Bourgeois, B., Hazlett, C., Henry, R., Boeder, S., Pettus, J., Diaz, E., Garcia-Acosta, D., Maggs, S., DeLue, C., Stallings, A., Castro, E., Hernandez, S., Krakoff, J., Curtis, J.M., Killean, T., Khalid, M., Joshevama, E., Diaz, E., Martin, D., Tsingine, K., Karshner, T., Albu, J., Pi-Sunyer, F.X., Frances, S., Maggio, C., Ellis, E., Bastawrose, J., Gong, X., Banerji, M.A., August, P., Lee, M., Lorber, D., Brown, N.M., Josephson, D.H., Thomas, L.L., Tsovian, M., Cherian, A., Jacobson, M.H., Mishko, M.M., Kirkman, M.S., Buse, J.B., Diner, J., Dostou, J., Machineni, S., Young, L., Bergamo, K., Goley, A., Kerr, J., Largay, J.F., Guarda, S., Cuffee, J., Culmer, D., Fraser, R., Almeida, H., Coffer, S., Debnam, E., Kiker, L., Morton, S., Josey, K., Fuller, G., Garvey, W.T., Cherrington, A.L., Dyer, D., Lawson, M.C.R., Griffith, O., Agne, A., McCullars, S., Cohen, R.M., Craig, J., Rogge, M.C., Burton, K., Kersey, K., Wilson, C., Lipp, S., Vonder Meulen, M.B., Adkins, C., Onadeko, T., Rasouli, N., Baker, C., Schroeder, E., Razzaghi, M., Lyon, C., Penaloza, R., Underkofler, C., Lorch, R., Douglass, S., Steiner, S., Sivitz, W.I., Cline, E., Knosp, L.K., McConnell, J., Lowe, T., Herman, W.H., Pop-Busui, R., Martin, C., Waltje, A., Katona, A., Goodhall, L., Eggleston, R., Kuo, S., Bojescu, S., Bule, S., Kessler, N., LaSalle, E., Whitley, K., Seaquist, E.R., Bantle, A., Harindhanavudhi, T., Kumar, A., Redmon, B., Bantle, J., Coe, M., Mech, M., Taddese, A., Lesne, L., Smith, S., Kuechenmeister, L., Shivaswamy, V., Burbach, S., Rodriguez, M.G., Seipel, K., Alfred, A., Morales, A.L., Eggert, J., Lord, G., Taylor, W., Tillson, R., Adolphe, A., Burge, M., Duran-Valdez, E., Martinez, J., Bancroft, A., Kunkel, S., Ali Jamaleddin Ahmad, F., Hernandez McGinnis, D., Pucchetti, B., Scripsick, E., Zamorano, A., DeFronzo, R.A., Cersosimo, E., Abdul-Ghani, M., Triplitt, C., Juarez, D., Mullen, M., Garza, R.I., Verastiqui, H., Wright, K., Puckett, C., Raskin, P., Rhee, C., Abraham, S., Jordan, L.F., Sao, S., Morton, L., Smith, O., Osornio Walker, L., Schnurr-Breen, L., Ayala, R., Kreymer, R.B., Sturgess, D., Kahn, S.E., Alarcon-Casas Wright, L., Boyko, E.J., Tsai, E.C., Trence, D.L., Trikudanathan, S., Fattaleh, B.N., Montgomery, B.K., Atkinson, K.M., Kozedub, A., Concepcion, T., Moak, C., Prikhodko, N., Rhothisen, S., Elasy, T.A., Martin, S., Shackelford, L., Goidel, R., Hinkle, N., Lovell, C., Myers, J., Lipps Hogan, J., McGill, J.B., Salam, M., Schweiger, T., Kissel, S., Recklein, C., Clifton, M.J., Tamborlane, W., Camp, A., Gulanski, B., Pham, K., Alguard, M., Gatcomb, P., Lessard, K., Perez, M., Iannone, L., Magenheimer, E., Montosa, A., Cefalu, W.T., Fradkin, J., Burch, H.B., Bremer, A.A., Nathan, D.M., Lachin, J.M., Buse, J.B., Kahn, S.E., Larkin, M.E., Tiktin, M., Wexler, D., Burch, H.B., Bremer, A.A., Lachin, J.M., Bebu, I., Butera, N., Buys, C.J., Fagan, A., Gao, Y., Gramzinski, M.R., Hall, S.D., Kazemi, E., Legowski, E., Liu, H., Suratt, C., Tripputi, M., Arey, A., Backman, M., Bethepu, J., Lund, C., Mangat Dhaliwal, P., McGee, P., Mesimer, E., Ngo, L., Steffes, M., Seegmiller, J., Saenger, A., Arends, V., Gabrielson, D., Conner, T., Warren, S., Day, J., Huminik, J., Soliman, E.Z., Zhang, Z.M., Campbell, C., Hu, J., Keasler, L., Hensley, S., Li, Y., Herman, W.H., Kuo, S., Martin, C., Waltje, A., Mihalcea, R., Min, D.J., Perez-Rosas, V., Prosser, L., Resnicow, K., Ye, W., Shao, H., Zhang, P., Luchsinger, J., Sanchez, D., Assuras, S., Groessl, E., Sakha, F., Chong, H., Hillery, N., Abdouch, I., Bahtiyar, G., Brantley, P., Broyles, F.E., Canaris, G., Copeland, P., Craine, J.J., Fein, W.L., Gliwa, A., Hope, L., Lee, M.S., Meiners, R., Meiners, V., O’Neal, H., Park, J.E., Sacerdote, A., Sledge Jr, E., Soni, L., Steppel-Reznik, J., and Turchin, A.

Published
2024
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4. Shock-driven periodic variability in a low-mass-ratio supermassive black hole binary.

Author

Whitley, K, Kuznetsova, A, Gültekin, K, and Ruszkowski, M

Subjects
*SUPERMASSIVE black holes, *BINARY black holes, *ECCENTRIC loads, *ACTIVE galactic nuclei, *ACCRETION (Astrophysics), *ECCENTRICS (Machinery), *HYDRODYNAMICS
Abstract

We investigate the time-varying electromagnetic emission of a low-mass-ratio supermassive black hole binary (SMBHB) embedded in a circumprimary disc, with a particular interest in variability of shocks driven by the binary. We perform a 2D, locally isothermal hydrodynamics simulation of an SMBHB with mass ratio q  = 0.01 and separation a  = 100  R g, using a physically self-consistent steady disc model. We estimate the electromagnetic variability from the system by monitoring accretion on to the secondary and using an artificial viscosity scheme to capture shocks and monitor the energy dissipated. The SMBHB produces a wide, eccentric gap in the disc, previously only observed for larger mass ratios, which we attribute to our disc model being much thinner (H / R ≈ 0.01 near the secondary) than is typical of previous works. The eccentric gap drives periodic accretion on to the secondary SMBH on a time-scale matching the orbital period of the binary, |$t_{\rm {bin}}\approx 0.1\,\,\rm {yr}$|⁠ , implying that the variable accretion regime of the SMBHB parameter space extends to lower mass ratios than previously established. Shocks driven by the binary are periodic, with a period matching the orbital period, and the shocks are correlated with the accretion rate, with peaks in the shock luminosity lagging peaks in the accretion rate by 0.43  t bin. We propose that the correlation of these quantities represents a useful identifier of SMBHB candidates, via observations of correlated variability in X-ray and ultraviolet monitoring of active galactic nuclei, rather than single-waveband periodicity alone. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Clinical and Metabolic Characterization of Adults With Type 2 Diabetes by Age in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE) Cohort

Author

Aroda, Vanita R., Krause-Steinrauf, Heidi, Kazemi, Erin J., Buse, John B., Gulanski, Barbara I., Florez, Hermes J., Ahmann, Andrew J., Loveland, Amy, Kuhn, Alexander, Lonier, Jacqueline Y., Wexler, Deborah J., Crandall, J.P., McKee, M.D., Behringer-Massera, S., Brown-Friday, J., Xhori, E., Ballentine-Cargill, K., Duran, S., Estrella, H., Gonzalez de la torre, S., Lukin, J., Phillips, L.S., Burgess, E., Olson, D., Rhee, M., Wilson, P., Raines, T.S., Boers, J., Costello, J., Maher-Albertelli, M., Mungara, R., Savoye, L., White, C.A., Gullett, C., Holloway, L., Morehead, F., Person, S., Sibymon, M., Tanukonda, S., Adams, C., Ross, A., Balasubramanyam, A., Gaba, R., Gonzalez Hattery, E., Ideozu, A., Jimenez, J., Montes, G., Wright, C., Hollander, P., Roe, E., Jackson, A., Smiley, A., Burt, P., Estrada, L., Chionh, K., Ismail-Beigi, F., Falck-Ytter, C., Sayyed Kassem, L., Sood, A., Tiktin, M., Kulow, T., Newman, C., Stancil, K.A., Cramer, B., Iacoboni, J., Kononets, M.V., Sanders, C., Tucker, L., Werner, A., Maxwell, A., McPhee, G., Patel, C., Colosimo, L., Krol, A., Goland, R., Pring, J., Alfano, L., Kringas, P., Hausheer, C., Tejada, J., Gumpel, K., Kirpitch, A., Schneier, H., Green, J.B., AbouAssi, H., Chatterjee, R., Feinglos, M.N., English Jones, J., Khan, S.A., Kimpel, J.B., Zimmer, R.P., Furst, M., Satterwhite, B.M., Thacker, C.R., Evans Kreider, K., Mariash, C.N., Mather, K.J., Ismail, H.M., Lteif, A., Mullen, M., Hamilton, T., Patel, N., Riera, G., Jackson, M., Pirics, V., Aguillar, D., Howard, D., Hurt, S., Bergenstal, R., Carlson, A., Martens, T., Johnson, M., Hill, R., Hyatt, J., Jensen, C., Madden, M., Martin, D., Willis, H., Konerza, W., Yang, S., Kleeberger, K., Passi, R., Fortmann, S., Herson, M., Mularski, K., Glauber, H., Prihoda, J., Ash, B., Carlson, C., Ramey, P.A., Schield, E., Torgrimson-Ojerio, B., Arnold, K., Kauffman, B., Panos, E., Sahnow, S., Bays, K., Berame, K., Cook, J., Ghioni, D., Gluth, J., Schell, K., Criscola, J., Friason, C., Jones, S., Nazarov, S., Barzilay, J., Rassouli, N., Puttnam, R., Ojoawo, B., Nelson, R., Curtis, M., Hollis, B., Sanders-Jones, C., Stokes, K., El-Haqq, Z., Kolli, A., Tran, T., Wexler, D., Larkin, M., Meigs, J., Chambers, B., Dushkin, A., Rocchio, G., Yepes, M., Steiner, B., Dulin, H., Cayford, M., Chu, K., DeManbey, A., Hillard, M., Martin, K., Thangthaeng, N., Gurry, L., Kochis, R., Raymond, E., Ripley, V., Stevens, C., Park, J., Aroda, V., Ghazi, A., Magee, M., Ressing, Ann, Loveland, A., Hamm, M., Hurtado, M., Kuhn, A., Leger, J., Manandhar, L., Sanchez, O., Young, T., Mofor, F., Garg, R., Lagari-Libhaber, V., Florez, H.J., Valencia, W.M., Marks, J., Casula, S., Oropesa-Gonzalez, L., Hue, L., Cuadot, A., Nieto-Martinez, R., Riccio Veliz, A.K., Gutt, M., Kendal, Y.J., Veciana, B., Ahmann, A., Aby-Daniel, D., Joarder, F., Morimoto, V., Sprague, C., Yamashita, D., Cady, N., Rivera-Eschright, N., Kirchhoff, P., Morales Gomez, B., Adducci, J., Goncharova, A., Hox, S.H., Petrovitch, H., Matwichyna, M., Jenkins, V., Broadwater, L., Ishii, R.R., Bermudez, N.O., Hsia, D.S., Cefalu, W.T., Greenway, F.L., Waguespack, C., King, E., Fry, G., Dragg, A., Gildersleeve, B., Arceneaux, J., Haynes, N., Thomassie, A., Pavlionis, M., Bourgeois, B., Hazlett, C., Mudaliar, S., Henry, R., Boeder, S., Pettus, J., Diaz, E., Garcia-Acosta, D., Maggs, S., DeLue, C., Stallings, A., Castro, E., Hernandez, S., Krakoff, J., Curtis, J.M., Killean, T., Khalid, M., Joshevama, E., Tsingine, K., Karshner, T., Albu, J., Pi-Sunyer, F.X., Frances, S., Maggio, C., Ellis, E., Bastawrose, J., Gong, X., Banerji, M.A., August, P., Lee, M., Lorber, D., Brown, N.M., Josephson, D.H., Thomas, L.L., Tsovian, M., Cherian, A., Jacobson, M.H., Mishko, M.M., Kirkman, M.S., Buse, J.B., Dostou, J., Machineni, S., Young, L., Bergamo, K., Goley, A., Kerr, J., Largay, J.F., Guarda, S., Cuffee, J., Culmer, D., Fraser, R., Almeida, H., Coffer, S., Debnam, E., Kiker, L., Morton, S., Josey, K., Fuller, G., Garvey, W.T., Cherrington, A.L., Dyer, D., Lawson, M.C.R., Griffith, O., Agne, A., McCullars, S., Cohen, R.M., Craig, J., Rogge, M.C., Burton, K., Kersey, K., Wilson, C., Lipp, S., Vonder Meulen, M.B., Adkins, C., Onadeko, T., Rasouli, N., Baker, C., Schroeder, E., Razzaghi, M., Lyon, C., Penaloza, R., Underkofler, C., Lorch, R., Douglass, S., Steiner, S., Sivitz, W.I., Cline, E., Knosp, L.K., McConnell, J., Lowe, T., Herman, W.H., Pop-Busui, R., Tan, M.H., Martin, C., Waltje, A., Katona, A., Goodhall, L., Eggleston, R., Kuo, S., Bojescu, S., Bule, S., Kessler, N., LaSalle, E., Whitley, K., Seaquist, E.R., Bantle, A., Harindhanavudhi, T., Kumar, A., Redmon, B., Bantle, J., Coe, M., Mech, M., Taddese, A., Lesne, L., Smith, S., Desouza, C., Kuechenmeister, L., Shivaswamy, V., Burbach, S., Rodriguez, M.G., Seipel, K., Alfred, A., Morales, A.L., Eggert, J., Lord, G., Taylor, W., Tillson, R., Schade, D.S., Adolphe, A., Burge, M., Duran-Valdez, E., Martinez, J., Bancroft, A., Kunkel, S., Ali Jamaleddin Ahmad, F., Hernandez McGinnis, D., Pucchetti, B., Scripsick, E., Zamorano, A., DeFronzo, R.A., Cersosimo, E., Abdul-Ghani, M., Triplitt, C., Juarez, D., Garza, R.I., Verastiqui, H., Wright, K., Puckett, C., Raskin, P., Rhee, C., Abraham, S., Jordan, L.F., Sao, S., Morton, L., Smith, O., Osornio Walker, L., Schnurr-Breen, L., Ayala, R., Kreymer, R.B., Sturgess, D., Utzschneider, K.M., Kahn, S.E., Alarcon-Casas, L., Wright, L., Boyko, E.J., Tsai, E.C., Trence, D.L., Trikudanathan, S., Fattaleh, B.N., Montgomery, B.K., Atkinson, K.M., Kozedub, A., Concepcion, T., Moak, C., Prikhodko, N., Rhothisen, S., Elasy, T.A., Martin, S., Shackelford, L., Goidel, R., Hinkle, N., Lovell, C., Myers, J., Lipps Hogan, J., McGill, J.B., Salam, M., Schweiger, T., Kissel, S., Recklein, C., Clifton, M.J., Tamborlane, W., Camp, A., Gulanski, B., Inzucchi, S.E., Pham, K., Alguard, M., Gatcomb, P., Lessard, K., Perez, M., Iannone, L., Magenheimer, E., Montosa, A., Burch, H.B., Bremer, A.A., Fradkin, J., Nathan, D.M., Lachin, J.M., Krause-Steinrauf, H., Younes, N., Backman, M., Bebu, I., Butera, N., Buys, C.J., Fagan Murphy, A., Gao, Y., Ghosh, A., Gramzinski, M.R., Kazemi, E., Hall, S.D., Legowski, E., Suratt, C., Tripputi, M., Arey, A., Bethepu, J., Lund, C., Mangat Dhaliwal, P., McGee, P., Mesimer, E., Ngo, L., Steffes, M., Seegmiller, J., Saenger, A., Arends, V., Gabrielson, D., Conner, T., Warren, S., Day, J., Huminik, J., Scrymgeour, A., Soliman, E.Z., Pokharel, Y., Zhang, Z.M., Campbell, C., Hu, J., Keasler, L., Hensley, S., Li, Y., Mihalcea, R., Min, D.J., Perez-Rosas, V., Prosser, L., Resnicow, K., Ye, W., Shao, H., Zhang, P., Luchsinger, J., Sanchez, D., Assuras, S., Groessl, E., Sakha, F., Chong, H., Hillery, N., Everett, B.M., Abdouch, I., Bahtiyar, G., Brantley, P., Broyles, F.E., Canaris, G., Copeland, P., Craine, J.J., Fein, W.L., Gliwa, A., Hope, L., Lee, M.S., Meiners, R., Meiners, V., O’Neal, H., Park, J.E., Sacerdote, A., Sledge, E., Soni, L., Steppel-Reznik, J., Turchin, A., Brooks-Worrell, B., Hampe, C.S., Newgard, C.B., Palmer, J.P., Shojaie, A., Higgins, J., Fischer, L., Golden, S., Gonzalez, J., Naik, A., Walker, E., Doner Lotenberg, L., Gallivan, J.M., Lim, J., and Tuncer, D.M.

Subjects
Clinical Care/Education/Nutrition/Psychosocial Research
Abstract

OBJECTIVE: Differences in type 2 diabetes phenotype by age are described, but it is not known whether these differences are seen in a more uniformly defined adult population at a common early stage of care. We sought to characterize age-related clinical and metabolic characteristics of adults with type 2 diabetes on metformin monotherapy, prior to treatment intensification. RESEARCH DESIGN AND METHODS: In the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE), participants were enrolled who had type 2 diabetes duration

Published
2022

12. Metatranscriptomic analysis of multiple environmental stresses identifies RAP2.4 gene associated with arabidopsis immunity to Botrytis cinerea

Author

Sham, A., Al-Ashram, H., Whitley, K., Iratni, R., El-Tarabily, K.A., AbuQamar, S.F., Sham, A., Al-Ashram, H., Whitley, K., Iratni, R., El-Tarabily, K.A., and AbuQamar, S.F.

Abstract

In this study, we aimed to identify common genetic components during stress response responsible for crosstalk among stresses, and to determine the role of differentially expressed genes in Arabidopsis-Botrytis cinerea interaction. Of 1,554 B. cinerea up-regulated genes, 24%, 1.4% and 14% were induced by biotic, abiotic and hormonal treatments, respectively. About 18%, 2.5% and 22% of B. cinerea down-regulated genes were also repressed by the same stress groups. Our transcriptomic analysis indicates that plant responses to all tested stresses can be mediated by commonly regulated genes; and protein-protein interaction network confirms the cross-interaction between proteins regulated by these genes. Upon challenges to individual or multiple stress(es), accumulation of signaling molecules (e.g. hormones) plays a major role in the activation of downstream defense responses. In silico gene analyses enabled us to assess the involvement of RAP2.4 (related to AP2.4) in plant immunity. Arabidopsis RAP2.4 was repressed by B. cinerea, and its mutants enhanced resistance to the same pathogen. To the best of our knowledge, this is the first report demonstrating the role of RAP2.4 in plant defense against B. cinerea. This research can provide a basis for breeding programs to increase tolerance and improve yield performance in crops.

Published
2019

15. Innovative Materials for Aircraft Morphing

Author

Simpson, J. O, Wise, S. A, Bryant, R. G, Cano, R. J, Gates, T. S, Hinkley, J. A, Rogowski, R. S, and Whitley, K. S

Subjects
Nonmetallic Materials
Abstract

Reported herein is an overview of the research being conducted within the Materials Division at NASA Langley Research Center on the development of smart material technologies for advanced airframe systems. The research is a part of the Aircraft Morphing Program which is a new six-year research program to develop smart components for self-adaptive airframe systems. The fundamental areas of materials research within the program are computational materials; advanced piezoelectric materials; advanced fiber optic sensing techniques; and fabrication of integrated composite structures. This paper presents a portion of the ongoing research in each of these areas of materials research.

Published
1997

16. Crosslinking-property relationships in PMR polyimide composites. I

Author

Pater, R. H, Whitley, K, Morgan, C, and Chang, A

Subjects
Composite Materials
Abstract

The effect of the crosslink density of the matrix on physical and mechanical properties of a graphite-fiber-reinforced PMR (for polymerization of monomer reactants) polyimide composites during isothermal aging was investigated in experiments where unidirectional composite specimens of Celion 6000/PMR-P1 were isothermally exposed at 288 C in air for various time periods up to 5000 hrs. It was found that, as the crosslink density increased, the glass transition temperature, density, and elevated-temperature interlaminar shear strength of a composite increased, while the initial moisture absorption and the coefficient of thermal expansion decreased. However, after reaching the highest possible matrix crosslink density, several of the composite properties began to deteriorate rapidly.

Published
1991
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17. Space Station Freedom environmental control and life support system phase 3 simplified integrated test detailed report

Author

Roberts, B. C, Carrasquillo, R. L, Dubiel, M. Y, Ogle, K. Y, Perry, J. L, and Whitley, K. M

Subjects
Spacecraft Design, Testing And Performance
Abstract

A description of the phase 3 simplified integrated test (SIT) conducted at the Marshall Space Flight Center (MSFC) Core Module Integration Facility (CMIF) in 1989 is presented. This was the first test in the phase 3 series integrated environmental control and life support systems (ECLSS) tests. The basic goal of the SIT was to achieve full integration of the baseline air revitalization (AR) subsystems for Space Station Freedom. Included is a description of the SIT configuration, a performance analysis of each subsystem, results from air and water sampling, and a discussion of lessons learned from the test. Also included is a full description of the preprototype ECLSS hardware used in the test.

Published
1990

22. Crosslinking-property relationships in PMR polyimide composites. I

Author

Pater, R. H, Whitley, K, Morgan, C, and Chang, A

Subjects
Composite Materials
Abstract

The thermooxidatively-induced crosslinking/ physical and mechanical property relationships of graphite fiber-reinforced PMR polyimide-matrix composites were studied during isothermal exposure of the composite specimens at 288 C in air for periods of up to 5000 hr. The crosslinking densities due to this treatment were estimated on the basis of the kinetic theory of rubber elasticity and shifts in the glass transition temperature T(g). Several linear relationships are noted between crosslink density and physical and mechanical properties: T(g), initial weight loss, and elevated temperature interlaminar shear strength increase with crosslink density, while initial moisture absorption decreases. After achieving the highest crosslink density, several of the composite properties begin to decrease from their maximum values.

Published
1987

23. A statistical study of large electric field events in the earth's magnetotail

Author

Levin, S, Whitley, K, and Mozer, F. S

Subjects
Geophysics
Abstract

A statistical study of large electric field events, measured on ISEE 1 at geocentric distances of 3 to 23 earth radii, has been performed in order to determine the occurrence frequency and spatial distribution of such events. Large electric fields were seen at all altitudes, with the lowest altitude events occurring on auroral field lines and the higher altitude events occurring on the high latitude boundary of the plasma sheet. The largest events had amplitudes that were approximately proportional to the square root of the local magnetic field strength, in agreement with expectations of a simple mapping model. The apparent concentration of big field events near local midnight is caused, at least in part, by a nonuniform frequency of satellite crossings through the plasma sheet boundary as a function of local time. Thus, the spatial distribution and amplitudes of the large field events are not inconsistent with the mapping of low-altitude electrostatic shocks to the plasma sheet boundary along equipotential magnetic field lines.

Published
1983

28. Innovative materials for aircraft morphing

Author

Harrison, Joycelyn S., primary, Wise, Stephanie A., additional, Bryant, Robert G., additional, Cano, Roberto J., additional, Gates, Thomas S., additional, Hinkley, Jeffrey A., additional, Rogowski, Robert S., additional, and Whitley, K. S., additional

Published
1998
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31. Magnetic resonance imaging in children with sickle cell disease--detecting alterations in the apparent diffusion coefficient in hips with avascular necrosis.

Author

Mackenzie JD, Hernandez A, Pena A, Ruppert K, Khrichenko D, Gonzalez L, Jawad AF, Wells L, Smith-Whitley K, Jaramillo D, Mackenzie, John D, Hernandez, Andrea, Pena, Andres, Ruppert, Kai, Khrichenko, Dmitry, Gonzalez, Leonardo, Jawad, Abbas F, Wells, Lawrence, Smith-Whitley, Kim, and Jaramillo, Diego

Abstract

Background: Avascular necrosis (AVN) is a common morbidity in children with sickle cell disease (SCD) that leads to pain and joint immobility. However, the diagnosis is often uncertain or delayed.Objective: To examine the ability of apparent diffusion coefficient (ADC) measurements on diffusion-weighted imaging to detect AVN in children with SCD.Materials and Methods: ADC values were calculated at the hips of normal children (n = 19) and children with SCD who were either asymptomatic with no known previous hip disease (n = 13) or presented for the first time with clinical symptoms of hip pathology (n = 12). ADC values were compared for differences among groups with and without AVN using non-parametric statistical methods.Results: The ADC values were elevated in the hips of children with AVN (median ADC = 1.57 × 10(-3) mm(2)/s [95% confidence interval = 0.86-2.10]) and differed significantly in pairwise comparisons (all P < 0.05) from normal children (0.74 [0.46-0.98]), asymptomatic children with SCD (0.55 [0.25-0.85]), and SCD children who had symptoms referable to their hips but did not show findings of hip AVN on conventional MRI or radiographs (0.46 [0.18-0.72]).Conclusion: Children with sickle cell disease have elevated apparent diffusion coefficient values in their affected hips on initial diagnosis of avascular necrosis. [ABSTRACT FROM AUTHOR]

Published
2012
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34. Parent factors and adolescent sickle cell disease: associations with patterns of health service use.

Author

Logan, D.E., Radcliffe, J., Smith-Whitley, K., Logan, Deirdre E, Radcliffe, Jerilynn, and Smith-Whitley, Kim

Subjects
SICKLE cell anemia, TEENAGERS, PARENTS, EDUCATION of parents, DECISION making, ECONOMIC aspects of diseases, HEALTH attitudes, MULTIVARIATE analysis, PARENT-child relationships, PSYCHOLOGY of parents, PSYCHOLOGY of children with disabilities, REGRESSION analysis, PSYCHOLOGICAL stress, MEDICAL care for teenagers
Abstract

Objective: To examine relationships among parent characteristics (parent-adolescent relationship, parents' illness knowledge, and parents' perceptions of illness-related burden) and use of routine and urgent health services among adolescents with sickle cell disease (SCD).Method: Seventy adolescents, ages 12-18, and their parents completed questionnaires assessing illness knowledge, perceptions of illness burden, parent-adolescent relationships, and adolescents' psychological functioning. Information about pain, routine services (i.e., care at home, clinic visits) and urgent service use (i.e., emergency department visits, hospitalizations) was obtained from parents and medical records.Results: After we controlled for disease severity and life events, parents' perception of more illness-related stress was the strongest predictor of both types of service use. Greater parental knowledge about SCD also related to higher frequency of routine service use. Disease severity was strongly associated with frequency of urgent service use.Conclusions: Both parent characteristics and disease severity were associated with patterns of service use. Enhancing aspects of parental functioning may help families make adaptive decisions regarding health care services for SCD pain management. [ABSTRACT FROM AUTHOR]

Published
2002
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36. Pneumococcal colonization in children with sickle cell disease

Author

Norris, C.F., Mahannah, S.R., Smith-Whitley, K., Ohene-Frempong, K., and McGowan, K.L.

Abstract

OBJECTIVE: The goals of this prospective study were to define the Streptococcus pneumoniae colonization rate in children with sickle cell disease (SCD) at the Children's Hospital of Philadelphia and to determine the serotype and antibiotic susceptibility of all isolates. METHODS: Children with SCD followed at the hospital were sampled for colonization with S. pneumoniae by means of a throat or nasopharyngeal swab on one or two occasions. Patient information was obtained when the specimen was collected. Specimens were isolated on gentamicin-blood agar plates and modified Avery broth. Antibiotic susceptibility was determined by a commercially available test (E-test). Isolates were serotyped with the use of type-specific antisera. The relationship between the data noted above and certain clinical parameters was examined. RESULTS: A total of 490 specimens were obtained from 278 patients. Twenty-eight patients had a culture positive for S. pneumoniae, resulting in an overall colonization rate of 10%. Thirty-three percent (11/33) of all isolates were resistant to penicillin-seven intermediately resistant and four highly resistant. Twelve percent of isolates were also resistant to cefotaxime. Eight different serotypes were identified; all but one are included in the current 23-valent pneumococcal vaccine. Penicillin prophylaxis did not increase the rate of colonization with resistant strains of pneumococcus. CONCLUSION: Our results do not support a change in the current use of penicillin prophylaxis nor in the acute management of the febrile child with SCD. (J Pediatr 1996;129:821-7)

Published
1996
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38. Innervation of vasculature and microvasculature of the human vagina by NOS and neuropeptide-containing nerves

Author

Charles H. V. Hoyle, Stones, Rw, Robson, T., Whitley, K., and Burnstock, G.

Subjects
Adult, Neurotransmitter Agents, Calcitonin Gene-Related Peptide, Microcirculation, Middle Aged, Substance P, Immunohistochemistry, Capillary Permeability, Vagina, Humans, Female, Neuropeptide Y, Neurons, Afferent, Nitric Oxide Synthase, Research Article, Aged, Vasoactive Intestinal Peptide
Abstract

The aims of the present study were to determine whether nerves that contain nitric oxide synthase (NOS), calcitonin gene-related peptide (CGRP) or substance P (SP) are present in the human vagina and, if so, to determine the pattern of innervation relative to that of other neurotransmitters, particularly vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Surgical specimens of vaginal tissue (n = 10) from pre- and postmenopausal women were fixed and processed for immunohistochemistry of peptides and NOS and for histochemistry of NADPH-diaphorase. SP-immunoreactive nerves were very sparse, being absent from 9 of the 10 tissue samples. For other peptides and NOS, the innervation of the deep arteries and veins was greater than that of blood vessels in the propria. Capillaries in the epithelial papillae also appeared to be innervated by nerves containing NOS, CGRP, NPY and VIP. Beneath the epithelium nerve fibres formed a subepithelial plexus; no nerve cell bodies were seen. The relative density of innervation by immunoreactive fibres was PGP-9.5 > NPY > VIP >> NOS > CGRP > SP. These results imply that nerves that utilise nitric oxide or NPY, VIP or CGRP as a neurotransmitter may play a role in controlling blood flow and capillary permeability in the human vagina. The origin and function of all these nerves is discussed.

41. Severe iron deficiency anemia in young children

Author

Kwiatkowski, J.L., West, T.B., Heidary, N., Smith-Whitley, K., and Cohen, A.R.

Abstract

We retrospectively characterized clinical features of 55 patients with severe nutritional iron deficiency anemia. Anemia was commonly discovered in the absence of related complaints. Forty percent of patients were of Southeast Asian ancestry. Most were treated successfully with iron therapy alone; 8 required transfusion. (J Pediatr 1999;135:514-6)

Published
1999
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43. Reader recommendation: Stoner.

Author

Whitley, K. B. (Ken)

Abstract

I have just finished reading Stoner, by John Williams -- a "hard" story, extremely well told. This book has led me to purchase "Butcher's Crossing" and "Augustus" (Winner of the National Book Award) also by John Williams. I am a happy camper. [ABSTRACT FROM AUTHOR]

Published
2014

44. Reader recommendation: Short Nights of the Shadow Catcher.

Author

Whitley, K. B. (Ken)

Abstract

I very recently finished reading Short Nights of the Shadow Catcher: The Epic Life and Immortal Photographs of Edward Curtis by Timothy Egan. This biography of a man obsessed tells not only the story of his life but perhaps more importantly the story of our treatment of the vanishing culture of the North American Indian. [ABSTRACT FROM AUTHOR]

Published
2014

46. Don't ignore the middle: Distinct mnemonic functions of intermediate hippocampus.

Author

Whitley K, Briggs SB, Sharma K, and Parent MB

Subjects
Animals, Male, Avoidance Learning physiology, Maze Learning physiology, Maze Learning drug effects, Rats, Long-Evans, Odorants, Rats, Hippocampus physiology, Memory physiology
Abstract

The dorsal region of the hippocampus (dHC) mediates many of the mnemonic functions traditionally associated with the hippocampus proper, such as spatial and episodic memory, whereas ventral hippocampus (vHC) has been extensively implicated in emotional memory and motivational processes. By contrast, the functions of the intermediate hippocampus (iHC) are far less understood. In this study, we aimed to investigate the mnemonic functions of iHC by reversibly inactivating iHC prior to testing memory in behavioral tasks dependent on the integrity of dHC, iHC, or vHC, namely, rapid place water maze, inhibitory avoidance, spontaneous alternation, and temporal ordering of odors. Given our previous findings showing that dHC and vHC are involved in mnemonic control of ingestive behavior, we also assessed the effects of iHC inactivation on sucrose intake. The results showed that pharmacological inhibition of iHC impairs rapid place water maze memory, which has been previously shown to be dependent on iHC but not dHC or vHC. iHC inactivation does not impact memory dependent on dHC (spontaneous alternation), vHC (temporal odor memory), or either dHC or vHC (inhibitory avoidance), and only modestly affects sucrose intake. These findings provide support for the involvement of iHC in mnemonic functions that are distinct from dHC and vHC and highlight the need to further advance our understanding of the functions of this hippocampal region that has been relatively understudied., (© 2024 Wiley Periodicals LLC.)

Published
2024
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47. The pervasive influence of systems of power on transition readiness for adult care in sickle cell disease: A qualitative study.

Author

Prussien KV, Faust HL, Crosby LE, Smith-Whitley K, Barakat LP, and Schwartz LA

Subjects
Humans, Male, Female, Adolescent, Adult, Young Adult, Focus Groups, Caregivers psychology, Follow-Up Studies, Anemia, Sickle Cell therapy, Anemia, Sickle Cell psychology, Transition to Adult Care, Qualitative Research
Abstract

Background: Adolescence and young adulthood are vulnerable developmental periods for individuals with sickle cell disease (SCD), particularly given the impact of social inequities, challenges with transitioning to adult healthcare services, and increased risk for morbidity and mortality. Systems of power, such as institutionalized and interpersonal manifestations of bias, could impact SCD transfer and engagement in adult care through their influence on healthcare transition readiness; yet research in this area is limited., Objective: To characterize how systems of power impact transition readiness factors described in the Social-ecological Model of AYA Readiness for Transition to Promote Health Equity (SMART-E) framework at the patient, caregiver, and practitioner levels., Methods: Pediatric adolescents and young adults (AYA), transferred AYA, caregivers, and practitioners participated in semi-structured focus groups and individual interviews examining health equity and systems of power during healthcare transition. Focus groups/interviews were transcribed and coded using a deductive approach via the updated SMART-E framework., Results: Ten pediatric AYA with SCD, nine transferred AYA with SCD, eight caregivers, and nine practitioners participated in a focus group or interview. Qualitative findings across reporters emphasize the impact of systems of power (e.g., racial bias and disease stigma) on knowledge, skills and self-efficacy, beliefs and expectations, goals and motivation, and emotions and psychosocial functioning at the patient, caregiver, and practitioner levels., Conclusion: Systems of power are prevalent with respect to transition barriers for AYA with SCD and their supports. Structural, institutional, and individual factors with potential to reduce the influence of systems of power should be further identified and targeted for intervention., (© 2024 Wiley Periodicals LLC.)

Published
2024
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48. Assessing multilevel barriers to hydroxyurea adherence in youth with sickle cell disease using pharmacy-based refill records.

Author

Smaldone A, Manwani D, Aygun B, Appiah-Kubi A, Smith-Whitley K, and Green NS

Subjects
Humans, Adolescent, Male, Child, Female, Drug Prescriptions statistics & numerical data, Hydroxyurea therapeutic use, Hydroxyurea administration & dosage, Anemia, Sickle Cell drug therapy, Medication Adherence statistics & numerical data, Antisickling Agents therapeutic use
Abstract

Background: Suboptimal medication adherence is common across youth with chronic health conditions and may contribute to health disparities and adverse health outcomes, especially in underserved communities., Methods: Using pharmacy prescription records and guided by the World Health Organization Multidimensional Adherence Model, we examined patient-, treatment-, and health system-related factors that may affect hydroxyurea adherence in 72 youth with sickle cell disease (SCD), 10-18 years who had participated in the multisite "Hydroxyurea Adherence for Personal Best in SCD" (HABIT) feasibility (6 months) and efficacy (12 months) trials. Pharmacy data were collected from the year prior to study entry through the duration of each trial. We also examined hydroxyurea dose at baseline, prescribing patterns (hydroxyurea formulation and dose prescribed), quantity of hydroxyurea dispensed, and number of daily capsules/tablets prescribed. Data were analyzed using descriptive statistics., Results: On average, youth were prescribed 1095 ± 402 mg hydroxyurea per day, requiring ingestion of 3 or more capsules for 39.4% of youth. Frequently identified potential barriers were complex medication regimens in which dose of hydroxyurea differed by day of week (47.2%); receipt of an inadequate (< 30 days) supply of hydroxyurea from the pharmacy ≥ 3 times during record collection period (29.2%); and prescription of hydroxyurea suspension suggesting problems swallowing capsules (22.2%). In this sample, most youth were exclusively prescribed 500 mg capsules (62.5%), which was associated with complex medication regimens (RR 3.0, 95% CI 1.4-6.7). Potential barriers were common, occurred at all levels and are potentially modifiable with targeted interventions at the treatment- and health system-related levels., (© 2024 Wiley Periodicals LLC.)

Published
2024
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49. Identification of genetic variants associated with clinical features of sickle cell disease.

Author

Tsukahara K, Chang X, Mentch F, Smith-Whitley K, Bhandari A, Norris C, Glessner JT, and Hakonarson H

Subjects
Humans, Male, Female, Adult, Phenotype, Genetic Predisposition to Disease, Adolescent, Fetal Hemoglobin genetics, Genotype, Acute Chest Syndrome genetics, Child, Young Adult, Genetic Variation, Anemia, Sickle Cell genetics, Genome-Wide Association Study, Polymorphism, Single Nucleotide, Quantitative Trait Loci
Abstract

Sickle cell disease (SCD) is an inherited blood disorder marked by homozygosity of hemoglobin S, which is a defective hemoglobin caused by a missense mutation in the β-globin gene. However, clinical phenotypes of SCD vary among patients. To investigate genetic variants associated with various clinical phenotypes of SCD, we genotyped DNA samples from 520 SCD subjects and used a genome-wide association study (GWAS) approach to identify genetic variants associated with phenotypic features of SCD. For HbF levels, the previously reported 2p16.1 locus (BCL11A) reached genome significance (rs1427407, P = 8.58 × 10 -10 ) in our GWAS as expected. In addition, we found a new genome-wide significance locus at 15q14 (rs8182015, P = 2.07 × 10 -8 ) near gene EMC7. GWAS of acute chest syndrome (ACS) detected a locus (rs79915189, P = 3.70 × 10 -8 ) near gene IDH2 at 15q26.1. The SNP, rs79915189, is also an expression quantitative trait locus (eQTL) of IDH2 in multiple tissues. For vasoocclusive episode (VOE), GWAS detected multiple significant signals at 2p25.1 (rs62118798, P = 4.27 × 10 -8 ), 15q26.1 (rs62020555, P = 2.04 × 10 -9 ) and 15q26.3 (rs117797325, P = 4.63 × 10 -8 ). Our findings provide novel insights into the genetic mechanisms of SCD suggesting that common genetic variants play an important role in the presentation of the clinical phenotypes of patients with SCD., (© 2024. The Author(s).)

Published
2024
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50. Investigating Professional Analyst Strategies in Immersive Space to Think.

Author

Davidson K, Lisle L, Tahmid IA, Whitley K, North C, and Bowman DA

Abstract

Existing research on sensemaking in immersive analytics systems primarily focuses on understanding how users complete analysis within these systems with quantitative and qualitative datasets. However, these user studies mainly concentrate on understanding analysis styles and methodologies from a predominantly novice user study population. While this approach provides excellent initial insights into what users may do within IA systems, it fails to address how professionals may utilize an immersive analytic system for analysis tasks. In our work, we build upon an existing immersive analytics concept - "Immersive Space to Think" to understand how professional user populations differ from novice users in immersive analytic system usage. We conducted a user study with 11 professional intelligence analysts who completed three analysis sessions each. Using our results from this study, we provide deep analysis into how professional users complete sensemaking within immersive analytic systems, compare our findings to previously published findings with a novice user population, and provide insights into how to develop better IA systems to support the professional analyst's strategies within these systems.

Published
2024
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