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203 results on '"Ryder, H"'

1. Infrared Colors of Small Serendipitously-Found Asteroids in the UKIRT Hemisphere Survey

Author

Morrison, Samantha G., Strauss, Ryder H., Trilling, David E., López-Oquendo, Andy J., Bruursema, Justice, and Vrba, Frederick J.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The UKIRT Hemisphere Survey covers the northern sky in the infrared from 0-60 degrees declination. Current data releases include both J and K bands, with H-band data forthcoming. Here we present a novel pipeline to recover asteroids from this survey data. We recover 26,138 reliable observations, corresponding to 23,399 unique asteroids, from these public data. We measure J-K colors for 601 asteroids. Our survey extends about two magnitudes deeper than 2MASS. We find that our small inner main belt objects are less red than larger inner belt objects, perhaps because smaller asteroids are collisionally younger, with surfaces that have been less affected by space weathering. In the middle and outer main belt, we find our small asteroids to be redder than larger objects in their same orbits, possibly due to observational bias or a disproportionate population of very red objects among these smaller asteroids. Future work on this project includes extracting moving object measurements from H and Y band data when it becomes available., Comment: 15 pages, 10 figures

Published
2024

2. Jupiter Co-Orbital Comet P/2023 V6 (PANSTARRS): Orbital History and Modern Activity State

Author

Kareta, Theodore, Noonan, John W., Volk, Kathryn, Strauss, Ryder H., and Trilling, David

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The discovery of the transient Jupiter co-orbital comet P/2019 LD2 (ATLAS) drew significant interest. Not only will LD2 transition between being a Centaur and a Jupiter Family Comet (JFC) in 2063, the first time this process can be observed as it happens, it is also very active for its large heliocentric distance. We present observations and orbital integrations of the newly discovered transient Jupiter co-orbital comet P/2023 V6 (PANSTARRS), the second such object known. Despite similar modern orbits, V6 is significantly (15 times) less active than LD2 and most JFCs as determined via Afrho measurements at the same heliocentric distance. We find V6 is co-orbital between 2020 and 2044, twice the duration of LD2, but it will not become a JFC soon. We interpret these differences in activity as evolutionary, with V6 having lost a significant fraction of its near-surface ice compared to LD2 by previously being warmer. While V6's pre-encounter orbit was somewhat warmer than LD2's, future thermal modeling will be needed to understand if this can explain their differences or if a more significant difference further into the past is required. This is more evidence that LD2 is a pristine and ice-rich object, and thus it may display very strong activity when it becomes a JFC. We sue the differences between V6 and LD2 to discuss the interpretation of cometary activity at large heliocentric distances as well as the small end of the crater record of the Galilean Satellites. Continuing observations of both objects are highly encouraged., Comment: Accepted for publication in the Astrophysical Journal: Letters on April 11, 2024. Four figures, fifteen pages

Published
2024

3. Exoplanet Analog Observations of Earth from Galileo Disk-integrated Photometry

Author

Strauss, Ryder H., Robinson, Tyler D., Trilling, David E., Cummings, Ryan, and Smith, Christopher J.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Galileo spacecraft had distant encounters with Earth in 1990 and 1992. Limited Solid State Imager (SSI) data acquired during these encounters has been previously presented, but the majority of the data from these Earth flybys have not been presented in the literature. Observations of Earth taken from afar are both rare and directly relevant to the development of any future exo-Earth direct imaging mission. Here we present a pipeline that vets, calibrates, and measures the disk-integrated brightness of the Earth, in multiple filters, from the complete SSI data sets from both the 1990 and 1992 Galileo flybys. The result is over 1500 usable photometric measurements for Earth as an analog for an exoplanet. The 1990 data set includes full rotational lightcurves in six bandpasses spanning the optical range. The 1992 data set is more limited, with lightcurves only spanning 14 hr. Time-averaged photometry for both encounters is presented while variability and color are discussed relative to findings from NASA's EPOXI mission (which also provided photometric lighturves for Earth). The new Galileo/SSI data are used to further validate the Virtual Planetary Laboratory 3D spectral Earth model, which often serves as a stand-in for true disk-integrated observations of our planet. The revived Galileo/SSI data for Earth is a testament to the ability of NASA's Planetary Data System to maintain data over decades-long timescales. The disk-integrated products derived from these data add to a very short list of calibrated and published whole-disk observations of the Pale Blue Dot.

Published
2024
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4. The Sizes and Albedos of Centaurs 2014 YY $_{49}$ and 2013 NL $_{24}$ from Stellar Occultation Measurements by RECON

Author

Strauss, Ryder H., Leiva, Rodrigo, Keller, John M., Wilde, Elizabeth, Buie, Marc W., Weryk, Robert J., Kavelaars, JJ, Bridges, Terry, Wasserman, Lawrence H., Trilling, David E., Ainsworth, Deanna, Anthony, Seth, Baker, Robert, Bardecker, Jerry, Bean Jr., James K, Bock, Stephen, Chase, Stefani, Dean, Bryan, Frei, Chessa, George, Tony, Gill, Harnoorat, Gimple, H. Wm., Givot, Rima, Hopfe, Samuel E., Cota Jr., Juan M., Kehrli, Matthew, King, Rebekah, Haley, Sean L., Lara, Charisma, Lund, Nels, Mattes, Martin L., McCandless, Keitha, McCrystal, Delsie, McRae, Josh, Melgarejo, Leonardo Emmanuel Rodriguez, Mendoza, Paola, Miller, Alexandra, Norfolk, Ian R., Palmquist, Bruce, Reaves, Robert D., Rivard, Megan L, von Schalscha, Michael, Schar, Ramsey, Stoffel, Timothy J, Swanson, Diana J., Thompson, Doug, Wise, J. A., Woods, Levi, and Yang, Yuehai

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

In 2019, the Research and Education Collaborative Occultation Network (RECON) obtained multiple-chord occultation measurements of two centaur objects: 2014 YY$_{49}$ on 2019 January 28 and 2013 NL$_{24}$ on 2019 September 4. RECON is a citizen-science telescope network designed to observe high-uncertainty occultations by outer solar system objects. Adopting circular models for the object profiles, we derive a radius $r=16^{+2}_{-1}$km and a geometric albedo $p_V=0.13^{+0.015}_{-0.024}$ for 2014 YY$_{49}$, and a radius $r=66 ^{+5}_{-5}$km and geometric albedo $p_V = 0.045^{+0.006}_{-0.008}$ for 2013 NL$_{24}$. To the precision of these measurements, no atmosphere or rings are detected for either object. The two objects measured here are among the smallest distant objects measured with the stellar occultation technique. In addition to these geometric constraints, the occultation measurements provide astrometric constraints for these two centaurs at a higher precision than has been feasible by direct imaging. To supplement the occultation results, we also present an analysis of color photometry from the Pan-STARRS surveys to constrain the rotational light curve amplitudes and spectral colors of these two centaurs. We recommend that future work focus on photometry to more deliberately constrain the objects' colors and light curve amplitudes, and on follow-on occultation efforts informed by this astrometry.

Published
2021
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5. Jupiter Co-Orbital Comet P/2023 V6 (PANSTARRS): Orbital History and Modern Activity State

Author

Theodore Kareta, John W. Noonan, Kathryn Volk, Ryder H. Strauss, and David Trilling

Subjects
Comets, Comet dynamics, Centaur group, Astrophysics, QB460-466
Abstract

The discovery of the transient Jupiter co-orbital comet P/2019 LD2 (ATLAS) drew significant interest. Not only will LD2 transition between being a Centaur and a Jupiter-family comet (JFC) in 2063, the first time this process can be observed as it happens, it is also very active for its large heliocentric distance. We present observations and orbital integrations of the newly discovered transient Jupiter co-orbital comet P/2023 V6 (PANSTARRS), the second such object known. Despite similar modern orbits, V6 is significantly (15×) less active than LD2 and most JFCs as determined via Af ρ measurements at the same R _H . We find that V6 is co-orbital between 2020 and 2044, twice the duration of LD2, but it will not become a JFC soon. We interpret these differences in activity as evolutionary, with V6 having lost a significant fraction of its near-surface ice compared to LD2 by previously being warmer. While V6's pre-encounter orbit was somewhat warmer than LD2's, future thermal modeling will be needed to understand if this can explain their differences or if a more significant difference further into the past is required. This is more evidence that LD2 is a pristine and ice-rich object, and thus it may display very strong activity when it becomes a JFC. We use the differences between V6 and LD2 to discuss the interpretation of cometary activity at large heliocentric distances as well as the small end of the cratering record of the Galilean satellites. Continuing observations of both objects are highly encouraged.

Published
2024
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6. Infrared Colors of Small Serendipitously Found Asteroids in the UKIRT Hemisphere Survey

Author

Samantha G. Morrison, Ryder H. Strauss, David E. Trilling, Andy J. López-Oquendo, Justice Bruursema, and Frederick J. Vrba

Subjects
Asteroids, Sky surveys, Near infrared astronomy, Main belt asteroids, Astronomy, QB1-991
Abstract

The UKIRT Hemisphere Survey covers the northern sky in the infrared from 0° to 60° decl. Current data releases include both J and K bands, with H -band data forthcoming. Here, we present a novel pipeline to recover asteroids from this survey data. We recover 26,138 reliable observations, corresponding to 23,399 unique asteroids, from these public data. We measure J – K colors for 601 asteroids. Our survey extends about 2 mag deeper than the Two-Micron All-Sky Survey. We find that our small inner main belt objects are less red than larger inner belt objects, perhaps because smaller asteroids are collisionally younger, with surfaces that have been less affected by space weathering. In the middle and outer main belts, we find our small asteroids to be redder than larger objects in their same orbits, possibly due to observational bias or a disproportionate population of very red objects among these smaller asteroids. Future work on this project includes extracting moving object measurements from H- and Y- band data when it becomes available.

Published
2024
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10. Mutants and SU(3)_q invariants

Author

Morton, H. R. and Ryder, H. J.

Subjects
Mathematics - Geometric Topology, Mathematics - Quantum Algebra, 57M25, 17B37, 22E47
Abstract

Details of quantum knot invariant calculations using a specific SU(3)_q-module are given which distinguish the Conway and Kinoshita-Teresaka pair of mutant knots. Features of Kuperberg's skein-theoretic techniques for SU(3)_q invariants in the context of mutant knots are also discussed., Comment: 17 pages. Published copy, also available at http://www.maths.warwick.ac.uk/gt/GTMon1/paper18.abs.html

Published
1998

11. Size and Shape of (11351) Leucus from Five Occultations

Author

Buie, Marc W., primary, Keeney, Brian A., additional, Strauss, Ryder H., additional, Blank, Ted E., additional, Moore, John G., additional, Porter, Simon B., additional, Wasserman, Lawrence H., additional, Weryk, Robert J., additional, Levison, Harold F., additional, Olkin, Catherine B., additional, Leiva, Rodrigo, additional, Bardecker, Jerry E., additional, Brown, Michael E, additional, Brown, Lilah B, additional, Collins, Michael P., additional, Davidson, Hugh M., additional, Dunham, David W., additional, Dunham, Joan B., additional, Eaccarino, John A., additional, Finley, Tiffany J., additional, Fuller, Lindsay, additional, Garcia, Maria L., additional, George, Tony, additional, Getrost, Kai, additional, Gialluca, Megan, T., additional, Givot, Rima M., additional, Gupton, David, additional, Hanna, William H., additional, Hergenrother, Carl William, additional, Hernandez, Yamir, additional, Hill, Bryan, additional, Hinton, P. C., additional, Holt, Timothy R., additional, Howell, Robert R, additional, Jewell, Jack Lee, additional, Kamin, Roxanne L., additional, Kammer, Joshua A., additional, Kareta, Theodore, additional, Kayl, Gregory J., additional, Keller, John M., additional, Kenyon, David A., additional, Kester, Scott R., additional, Kidd, John N., additional, Lauer, Tod R., additional, Leung, Cecilia W. S., additional, Lorusso, Zoey R., additional, Lundgren, Christopher B., additional, Magana, Lizeth O., additional, Maley, Paul D., additional, Marchis, Franck, additional, Marcialis, Robert L., additional, McCandless, Andrew E., additional, McCrystal, Delsie Joy, additional, McGraw, Allison Marie, additional, Miller, Kelly E., additional, Mueller, Beatrice E. A., additional, Noonan, J. W., additional, Olsen, Aart M., additional, Patton, Alexander R., additional, O’Conner Peluso, Daniel, additional, Person, Michael J., additional, Rigby, James G., additional, Rolfsmeier, Alex D, additional, Salmon, Julien J., additional, Samaniego, Joseph, additional, Sawyer, R. P., additional, Schulz, David M., additional, Skrutskie, Michael F, additional, Smith, Rose J. C., additional, Spencer, John R., additional, Springmann, Alessondra, additional, Stanbridge, Dale R., additional, Stoffel, Timothy J, additional, Tamblyn, Peter, additional, Tobias, Bryan, additional, Verbiscer, Anne J., additional, von Schalscha, Michael P., additional, Werts, Holly, additional, and Zhang, Qicheng, additional

Published
2021
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12. The sizes and albedos of Centaurs 2014 YY₄₉ and 2013 NL₂₄ from stellar occultation measurements by RECON

Author

Strauss, Ryder H., Leiva, Rodrigo, Keller, John M., Wilde, Elizabeth, Buie, Marc W., Weryk, Robert J., Kavelaars, JJ, Bridges, Terry, Wasserman, Lawrence H., Trilling, David E., Ainsworth, Deanna, Anthony, Seth, Baker, Robert, Bardecker, Jerry, Bean, James K, Bock, Stephen, Chase, Stefani, Dean, Bryan, Frei, Chessa, George, Tony, Gill, Harnoorat, Gimple, H. Wm., Givot, Rima, Hopfe, Samuel E., Cota, Juan M., Kehrli, Matthew, King, Rebekah, L. Haley, Sean, Lara, Charisma, Lund, Nels, Mattes, Martin L., McCandless, Keitha, McCrystal, Delsie, McRae, Josh, Rodriguez Melgarejo, Leonardo Emmanuel, Mendoza, Paola, Miller, Alexandra, Norfolk, Ian R., Palmquist, Bruce, Reaves, Robert D., Rivard, Megan L, von Schalscha, Michael, Schar, Ramsey, Stoffel, Timothy J, Swanson, Diana J., Thompson, Doug, Wise, J. A., Woods, Levi, and Yang, Yuehai

Subjects
stellar occultation, Centaur group
Abstract

In 2019, the Research and Education Collaborative Occultation Network (RECON) obtained multiple-chord occultation measurements of two Centaur objects: 2014 YY49 on 2019 January 28 and 2013 NL24 on 2019 September 4. RECON is a citizen-science telescope network designed to observe high-uncertainty occultations by outer solar system objects. Adopting circular models for the object profiles, we derive a radius r=16⁺²₋₁ km and a geometric albedo Pᵥ = 0.13⁺⁰.⁰¹⁵₋₀.₀₂₅ for 2014 YY49 and a radius r = 66⁺⁵₋₅ km and a geometric albedo Pᵥ = 0.045⁺⁰.⁰⁰⁶₋₀.₀₀₈ for 2013 NL₂₄. To the precision of these measurements, no atmosphere or rings are detected for either object. The two objects measured here are among the smallest distant objects measured with the stellar occultation technique. In addition to these geometric constraints, the occultation measurements provide astrometric constraints for these two Centaurs at a higher precision than has been feasible by direct imaging. To supplement the occultation results, we also present an analysis of color photometry from the Pan-STARRS surveys to constrain the rotational light curve amplitudes and spectral colors of these two Centaurs. We recommend that future work focus on photometry to more deliberately constrain the objects' colors and light curve amplitudes and on follow-on occultation efforts informed by this astrometry.

Published
2021

13. The Sizes and Albedos of Centaurs 2014 YY49 and 2013 NL24 from Stellar Occultation Measurements by RECON

Author

Strauss, Ryder H., primary, Leiva, Rodrigo, additional, Keller, John M., additional, Wilde, Elizabeth, additional, Buie, Marc W., additional, Weryk, Robert J., additional, Kavelaars, JJ, additional, Bridges, Terry, additional, Wasserman, Lawrence H., additional, Trilling, David E., additional, Ainsworth, Deanna, additional, Anthony, Seth, additional, Baker, Robert, additional, Bardecker, Jerry, additional, Bean, James K, additional, Bock, Stephen, additional, Chase, Stefani, additional, Dean, Bryan, additional, Frei, Chessa, additional, George, Tony, additional, Gill, Harnoorat, additional, Gimple, H. Wm., additional, Givot, Rima, additional, Hopfe, Samuel E., additional, Cota, Juan M., additional, Kehrli, Matthew, additional, King, Rebekah, additional, L. Haley, Sean, additional, Lara, Charisma, additional, Lund, Nels, additional, Mattes, Martin L., additional, McCandless, Keitha, additional, McCrystal, Delsie, additional, McRae, Josh, additional, Rodriguez Melgarejo, Leonardo Emmanuel, additional, Mendoza, Paola, additional, Miller, Alexandra, additional, Norfolk, Ian R., additional, Palmquist, Bruce, additional, Reaves, Robert D., additional, Rivard, Megan L, additional, von Schalscha, Michael, additional, Schar, Ramsey, additional, Stoffel, Timothy J, additional, Swanson, Diana J., additional, Thompson, Doug, additional, Wise, J. A., additional, Woods, Levi, additional, and Yang, Yuehai, additional

Published
2021
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16. The Sizes and Albedos of Centaurs 2014 YY49 and 2013 NL24 from Stellar Occultation Measurements by RECON.

Author

Strauss, Ryder H., Leiva, Rodrigo, Keller, John M., Wilde, Elizabeth, Buie, Marc W., Weryk, Robert J., Kavelaars, J. J., Bridges, Terry, Wasserman, Lawrence H., Trilling, David E., Ainsworth, Deanna, Anthony, Seth, Baker, Robert, Bardecker, Jerry, Bean Jr., James K., Bock, Stephen, Chase, Stefani, Dean, Bryan, Frei, Chessa, and George, Tony

Published
2021
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22. The effects of alcohol intoxication on accuracy and the confidence-accuracy relationship in photographic simultaneous lineups

Author

Flowe, H.D, Colloff, M.F, Karagolu, N, Zelek, K, Ryder, H, Humphries, Joyce, Takarangi, M.K.T, Flowe, H.D, Colloff, M.F, Karagolu, N, Zelek, K, Ryder, H, Humphries, Joyce, and Takarangi, M.K.T

Abstract

Acute alcohol intoxication during encoding can impair subsequent identification accuracy, but results across studies have been inconsistent, with studies often finding no effect. Little is also known about how alcohol intoxication affects the identification confidence-accuracy relationship. We randomly assigned women (n=153) to consume alcohol (dosed to achieve a 0.08% BAC) or tonic water, controlling for alcohol expectancy. Women then participated in an interactive hypothetical sexual assault scenario and, twenty-four hours or seven days later, attempted to identify the assailant from a perpetrator present or a perpetrator absent simultaneous lineup and reported their decision confidence. Overall, levels of identification accuracy were similar across the alcohol and tonic water groups. However, women who had consumed tonic water as opposed to alcohol identified the assailant with higher confidence on average. Further, calibration analyses suggested confidence is predictive of accuracy regardless of alcohol consumption. The theoretical and applied implications of our results are discussed.

Published
2017

23. Looking bad: Inferring criminality after 100 ms.

Author

Klatt, T, Maltby, J.J, Humphries, Joyce, Smailes, H.L, Ryder, H, Phelps, M, Flowe, H.D, Klatt, T, Maltby, J.J, Humphries, Joyce, Smailes, H.L, Ryder, H, Phelps, M, and Flowe, H.D

Abstract

Research finds we make spontaneous trait inferences from facial appearance, even after brief exposures to a face (i.e., ≤ 100 ms). We examined spontaneous impressions of criminality from facial appearance, testing whether these impressions persist after repeated presentation (i.e., one to three exposures) and increased exposure duration (100, 500, or 1000 ms) to the face. Judgement confidence and response times were recorded. Other participants viewed the faces for an unlimited period of time, rating trustworthiness dominance, and criminal appearance. We found evidence that participants spontaneously make criminal appearance attributions. These inferences persisted with repeated presentation and increased exposure duration, were related to trustworthiness and dominance ratings, and were made with high confidence. Implications are discussed.

Published
2016

24. Future performance in footracing.

Author

Ryder, Henry W., Carr, Harry Jay, Herget, Paul, Ryder, H W, Carr, H J, and Herget, P

Subjects
RUNNING, ATHLETES, PHYSICAL fitness, SPORTS, SPORTS sciences
Abstract

The article reports that running records are still far below the physiological limits of man. The limitations are due to psychological factors. Good runners do not push their limits. They are contented with setting a record or winning a medal. Almost all athletes are satisfied with breaking records.

Published
1976
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25. Gasanalytische Arbeiten

Author

Griffiths, E., Lundergardh, H., Hopfield, J. J., Welton, J. A., Perquin, J. N. J., Kling, K., Suchowiak, I., Hardebeck, Vilbrandt, F. C., Chamberlin, D. S., Newitt, D. M., Yant, W. P., Frey, F. E., Chatterji, N. G., Finch, G. J., Green, G. M., Tauch, E. J., Frederick, R. C., Lorah, J. R., Williams, K. T., Thompson, T. G., Dunoyer, L., Damfil, G. P., Wagstaff, J. E. P., Hoffmann, F. G., Tropsch, H., Wolf, O., Krause, Ryder, H. M., Shikata, K., Tausz, J., Jungmann, K., Bonte, J., Bamberger, M., Naussbaum, J., Froy, F. E., Wüster, A., Piwowarsky, E., and Rassfeld, P.

Published
1928
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26. The impact of beliefs about face recognition ability on memory retrieval processes in young and older adults

Author

Humphries, J E, Flowe, H D, Hall, L C, Williams, L C, Ryder, H L, Humphries, J E, Flowe, H D, Hall, L C, Williams, L C, and Ryder, H L

Abstract

This study examined whether beliefs about face recognition ability differentially influence memory retrieval in older compared to young adults. Participants evaluated their ability to recognise faces and were also given information about their ability to perceive and recognise faces. The information was ostensibly based on an objective measure of their ability, but in actuality, participants had been randomly assigned the information they received (high ability, low ability or no information control). Following this information, face recognition accuracy for a set of previously studied faces was measured using a remember–know memory paradigm. Older adults rated their ability to recognise faces as poorer compared to young adults. Additionally, negative information about face recognition ability improved only older adults’ ability to recognise a previously seen face. Older adults were also found to engage in more familiarity than item-specific processing than young adults, but information about their face recognition ability did not affect face processing style. The role that older adults’ memory beliefs have in the meta-cognitive strategies they employ is discussed.

Published
2015

27. The Shape of Space, 2d ed

Author

Ryder, H.

Subjects
The Shape of Space, 2d Ed (Book) -- Book reviews, Books -- Book reviews, Physics
Published
1996

29. Thrombin inhibitors based on ketone derivatives of arginine and lysine

Author

M. Szelke, A. C. Teger-Nilsson, Ryder H, B. Atrash, E. Gyzander, and D. M. Jones

Subjects
Ketone, Arginine, Isostere, Stereochemistry, Thrombin Time, Lysine, Molecular Sequence Data, Tripeptide, Thrombin time, Biochemistry, Antithrombins, Mass Spectrometry, Thrombin, medicine, Humans, Amino Acid Sequence, chemistry.chemical_classification, medicine.diagnostic_test, Molecular Structure, Chemistry, Anticoagulants, Esters, Ketones, Models, Chemical, Molecular Medicine, Oligopeptides, medicine.drug, Discovery and development of direct thrombin inhibitors
Abstract

Much attention is currently focused on inhibitors of thrombin as potential anticoagulants. We have previously reported thrombin inhibitors based on fragments of fibrinogen containing a ketomethylene isostere at P1-P'1. We now expand on these early findings by reporting on tripeptide based inhibitors of thrombin containing arginine or lysine ketones at the C-terminus. A large variety of such ketones have been studied and compared in their ability to increase the thrombin time in human plasma. In the case of arginine or lysine ketones the order of activity (i.e. decreasing IC50 TT) was: alkyl ketonesbeta-ketoestersdifluoro beta-ketoamidesalkyloxymethyl ketonesfluoroketones. Lysine analogues were generally found to be ca. ten-fold less active than their arginine counterparts. However, in the case of alpha-ketoesters the lysine derivatives were superior to all the types of arginine ketones studied (including the arginine alpha-keto ester derived thrombin inhibitor). A mechanistic explanation of the relative inactivity of the arginine alpha-keto ester derivative is proposed. All the highly electrophilic ketones were found to be slow-binding with thrombin.

Published
1995

38. Leukaemia near La Hague nuclear plant

Author

Clavel, J., primary, Hemon, D., additional, Law, G., additional, Roman, E., additional, Wakeford, R., additional, Barton, C., additional, Ryder, H., additional, Hesse-Honegger, C., additional, and Viel, J.-F., additional

Published
1997
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39. ChemInform Abstract: (3R)‐N‐(1‐(tert‐Butylcarbonylmethyl)‐2,3‐dihydro‐2‐oxo‐5‐(2‐pyridyl)‐ 1H‐1,4‐benzodiazepin‐3‐yl)‐N′‐(3(methylamino)phenyl)urea (YF476): A Potent and Orally Active Gastrin/CCK‐B Antagonist.

Author

SEMPLE, G., primary, RYDER, H., additional, ROOKER, D. P., additional, BATT, A. R., additional, KENDRICK, D. A., additional, SZELKE, M., additional, OHTA, M., additional, SATOH, M., additional, NISHIDA, A., additional, AKUZAWA, S., additional, and MIYATA, K., additional

Published
1997
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44. Scripture Inspiration and Modern Biblical Criticism

Author

Ryder, H. I. D., Ryder, H. I. D., Ryder, H. I. D., and Ryder, H. I. D.

Abstract

Catholic world. / Volume 56, Issue 336, Page(s) 742-754, (dlps) volume: bac8387.0056.336, (dlps) article: bac8387.0056.336:2, http://quod.lib.umich.edu/t/text/accesspolicy.html

46. Computer-Assisted Comparison of the Structural and Electronic Dispositions of Ebastine and Terfenadine.

Author

Segarra, V., López, M., Ryder, H., Palacios, J.M., and Roberts, D.J.

Subjects
ANTIHISTAMINES, PHARMACOLOGY
Abstract

Objective: Ebastine and terfenadine are both marketed nonsedating H histamine receptor antagonists. Although apparently similar in chemical structure, the compounds have different pharmacological profiles, particularly with respect to cardiac effects. These effects are consistently observed in a wide range of experimental models with terfenadine, but not with ebastine, despite the fact that the latter is more potent as an antihistamine. The objective of this study was to provide a structural basis to explain such differences. Design: A complete computer-assisted conformational and electronic characterisation was made for both drugs. Results: The preferred 3-dimensional spatial orientations were found to be different, as were the molecular locations of the highest occupied and lowest unoccupied molecular orbitals. Furthermore, for terfenadine, additional points of interaction as a hydrogen bond donor were found, which were not evident in ebastine or other noncardiotoxic antihistamines. These extra points of interaction were also found in other compounds that have shown cardiac effects similar to those of terfenadine. [ABSTRACT FROM AUTHOR]

Published
1999
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49. Synthesis and Structure−Activity Relationships of Novel Histamine H<INF>1</INF> Antagonists:  Indolylpiperidinyl Benzoic Acid Derivatives

Author

Fonquerna, S., Miralpeix, M., Pages, L., Puig, C., Cardus, A., Anton, F., Cardenas, A., Vilella, D., Aparici, M., Calaf, E., Prieto, J., Gras, J., Huerta, J. M., Warrellow, G., Beleta, J., and Ryder, H.

Abstract

A series of indolylpiperidinyl derivatives were prepared and evaluated for their activity as histamine H1 antagonists. Structure−activity relationship studies were directed toward improving in vivo activity and pharmacokinetic profile of our first lead (1). Substitution of fluorine in position 6 on the indolyl ring led to higher in vivo activity in the inhibition of histamine-induced cutaneous vascular permeability assay but lower selectivity toward 5HT2 receptor. Extensive optimization was carried out within this series and a number of histamine H1 antagonists showing potency and long duration of action in vivo and low brain penetration or cardiotoxic potential were identified. Within this novel series, indolylpiperidines 15, 20, 48, 51 and 52 exhibited a long half-life in rat and have been selected for further preclinical evaluation.

Published
2004

50. Synthesis and Biological Evaluation of 2-Phenylpyran-4-ones:  A New Class of Orally Active Cyclooxygenase-2 Inhibitors

Author

Caturla, F., Jimenez, J.-M., Godessart, N., Amat, M., Cardenas, A., Soca, L., Beleta, J., Ryder, H., and Crespo, M. I.

Abstract

A series of 2-phenylpyran-4-ones were prepared and evaluated for their ability to inhibit cyclooxygenase-2 (COX-2). Extensive structure−activity relationship work was carried out within this series, and a number of potent and selective COX-2 inhibitors were identified. Compounds having a p-methylsulfone group at the 2-phenyl ring showed the best COX-2 inhibitory activity. The introduction of a substituted phenoxy ring at position 3 enhanced both the in vitro and in vivo activity within the series. A selected group of 3-phenoxypyran-4-ones exhibited excellent activity in an experimental model of pyresis. The in vivo antiinflammatory activity of these compounds was confirmed with the evaluation of their antiarthritic and analgesic effectiveness. Moreover, their pharmacokinetic profile in rats is compatible with a once a day administration by oral route in humans. Within this novel series, compounds 21, 31, 34, and 35 have been selected for further preclinical and clinical evaluation.

Published
2004

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