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A Computerized Model Of Large-Scale Visual Interstellar Extinction, Jon Hakkila, Jeannette M. Myers, Brett J. Stidham, Dieter H. Hartmann Nov 1997

A Computerized Model Of Large-Scale Visual Interstellar Extinction, Jon Hakkila, Jeannette M. Myers, Brett J. Stidham, Dieter H. Hartmann

Publications

A numerical algorithm has been developed for calculating three-dimensional visual interstellar extinction and its error from inputs of Galactic longitude, Galactic latitude, and distance. The code sythesizes the results of several published studies and can be used both for making correction to individual observations and for correcting statisticlal samples. The studies have been modified to introduce a statistical extinction correction at large (poorly-sampled) distances, and to truncate values at the (assumed) edge of the Milky Way. When combined, the studies allow individual absorbing clouds in the interstellar medium to be indentified within 5 kpc. Several observational selection biases are noted …

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State Revenue: Projections To 2010, 1997 October 23, Holley Hewitt Ulbrich Oct 1997

State Revenue: Projections To 2010, 1997 October 23, Holley Hewitt Ulbrich

Publications

No abstract provided.

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Business Incentives: Projected Fiscal Costs, 1997 October 23, Daniel V. Rainey Oct 1997

Business Incentives: Projected Fiscal Costs, 1997 October 23, Daniel V. Rainey

Publications

No abstract provided.

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The Evolution Of Galactic Boron And The Production Site Of The Light Elements, D K. Duncan, F Primas, L M. Rebull, A M. Boesgaard, Constantine P. Deliyannis, L M. Hobbs, Jeremy R. King, S G. Ryan Oct 1997

The Evolution Of Galactic Boron And The Production Site Of The Light Elements, D K. Duncan, F Primas, L M. Rebull, A M. Boesgaard, Constantine P. Deliyannis, L M. Hobbs, Jeremy R. King, S G. Ryan

Publications

The Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST) has been used to obtain spectra of the 2500 Å region in eight stars with metallicities ranging from [Fe/H] = -0.4 to -3.0, including the most metal-poor star ever observed for boron. Spectrum synthesis utilizing latest Kurucz model atmospheres has been used to determine the B abundance for each star, with particular attention paid to the errors of each point, to permit judgment of the quality of the fit of models of Galactic chemical evolution. Previous observations were combined with new ones, bringing the number of stars analyzed …

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Retiree's Choice Of Community: The Importance Of Recreation And Parks, 1997 October, Kenneth F. Backman, Sheila J. Backman Oct 1997

Retiree's Choice Of Community: The Importance Of Recreation And Parks, 1997 October, Kenneth F. Backman, Sheila J. Backman

Publications

No abstract provided.

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Type X Silicon Carbide Presolar Grains: Type Ia Supernova Condensates?, Donald D. Clayton, David Arnett, Jave Kane, Bradley S. Meyer Sep 1997

Type X Silicon Carbide Presolar Grains: Type Ia Supernova Condensates?, Donald D. Clayton, David Arnett, Jave Kane, Bradley S. Meyer

Publications

In terms of nucleosynthesis issues alone, we demonstrate that the type X silicon carbide particles have chemical and isotopic compositions resembling those from explosive helium burning in 14N-rich matter. These particles are extracted chemically from meteorites and were once interstellar particles. They have already been identifed by their discoverers as supernova particles on the basis of their isotopic composi-tions, but we argue that they are from supernovae of Type Ia that explode with a cap of helium atop their CO structure. The relative abundances of the isotopes of C and Si and trace N, Mg, and Ca match those in …

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The Distance To The Hyades Cluster Based On Hubble Space Telescope Fine Guidance Sensor Parallaxes, W F. Van Altena, C.-L. Lu, J T. Lee, T M. Girard, X Guo, C P. Deliyannis, I Platais, V Kozhurina-Platais, B Mcarthur, Jeremy R. King Sep 1997

The Distance To The Hyades Cluster Based On Hubble Space Telescope Fine Guidance Sensor Parallaxes, W F. Van Altena, C.-L. Lu, J T. Lee, T M. Girard, X Guo, C P. Deliyannis, I Platais, V Kozhurina-Platais, B Mcarthur, Jeremy R. King

Publications

Trigonometric parallax observations made with the Hubble Space Telescope (HST) Fine Guidance Sensor (FGS) 3 of seven Hyades members in six fields of view have been analyzed along with their proper motions to determine the distance to the cluster. Knowledge of the convergent point and mean proper motion of the Hyades is critical to the derivation of the distance to the center of the cluster. Depending on the choice of the proper-motion system, the derived cluster center distance varies by 9%. Adopting a reference distance of 46.1 pc or m Ϫ M ϭ 3.32, which is derived from the ground-based …

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A Statistical Treatment Of The Gamma-Ray Burst "No Host Galaxy" Problem: I. Methodology, Dieter H. Hartmann, David L. Band Sep 1997

A Statistical Treatment Of The Gamma-Ray Burst "No Host Galaxy" Problem: I. Methodology, Dieter H. Hartmann, David L. Band

Publications

If gamma-ray bursts originate in galaxies at cosmological distances, the host galaxy should be detected if a burst error box is searched deep enough; are the host galaxies present? We present and implement a statistical methodology which evaluates whether the observed galaxy detections in a burst’s error box are consistent with the presence of the host galaxy, or whether all the detections can be attributed to unrelated background galaxies. This methodology requires the model-dependent distribution of host galaxy fluxes. While our methodology was derived for galaxies in burst error boxes, it can be applied to other candidate host objects (e.g., …

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Stellar Populations And The White Dwarf Mass Function: Connections To Supernova Ia Luminosities, Ted Von Hippel, G. D. Bothum, R. A. Schommer Sep 1997

Stellar Populations And The White Dwarf Mass Function: Connections To Supernova Ia Luminosities, Ted Von Hippel, G. D. Bothum, R. A. Schommer

Publications

We discuss the luminosity function of SNe Ia under the assumption that recent evidence for dispersion in this standard candle is related to variations in the white dwarf mass function (WDMF) in the host galaxies. We develop a simple parameterization of the WDMF as a function of age of a stellar population and apply this to galaxies of different morphological types. We show that this simplified model is consistent with the observed WDMF of Bergeron et al. (1992) for the solar neighborhood. Our simple models predict that WDMF variations can produce a range of more than 1.8 mag in MB(SN …

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Breakdown Of The Iron Passive Layer By Use Of The Scanning Electrochemical Microscope, David O. Wipf, John W. Still Aug 1997

Breakdown Of The Iron Passive Layer By Use Of The Scanning Electrochemical Microscope, David O. Wipf, John W. Still

Publications

The scanning electrochemical microscope (SECM) is used to generate localized corrosion at passivating iron surfaces by using the tip to generate Cl– ions. Use of the SECM allows the rapid establishment of a locally aggressive chemical environment at a pre-selected site on the iron surface. The susceptibility for passive-layer breakdown and corrosion initiation was examined as a function of the time between the start of the passive-layer growth and the formation of Cl- ions. The breakdown of the passive-layer was found to depend strongly on the passivation potential and the site of Cl- formation on the iron …

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Placing The Sun And Mainstream Sic Particles In Galactic Chemodynamic Evolution, Donald D. Clayton Jul 1997

Placing The Sun And Mainstream Sic Particles In Galactic Chemodynamic Evolution, Donald D. Clayton

Publications

This work continues to seek a possible paradigm for the existence of the mainstream of presolar SiC particles having 29Si 28Si and 30Si 28Si isotopic ratios larger than those found in solar material. The isotopic trend of the mainstream SiC presolar particles extracted from the meteorites and the isotopic composition of the Sun are both interpreted within a framework of Galactic evolution in which the stars diffuse substantial distances but the interstellar gas remains homogeneous at each value of Galactocentric radius. Viewed from the radial position of solar birth, which lies outside the bulk of the molecular-cloud scattering centers, the …

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Placing The Sun In Galactic Chemical Evolution: Mainstream Sic Particles, Donald D. Clayton, F X. Timmes Jul 1997

Placing The Sun In Galactic Chemical Evolution: Mainstream Sic Particles, Donald D. Clayton, F X. Timmes

Publications

We examine the consequences and implications of the possibilities that the best-fit m = 4/3 line of the silicon isotopic ratios measured in mainstream SiC grains is identical or parallel to the mean ISM evolution line of the silicon isotopes. Even though the mean ISM evolution proceeds along a line of unity slope when deviations are expressed in terms of the native representation (the mean ISM), the evolution line can become a slope 4/3 line in the solar representation, provided that the solar composition is displaced from the mean ISM evolution. During the course of this analysis, we introduce new …

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Midlands Institute For Non-Profit Management: Building A Solid Foundation, Center For Public Affairs Research (Cpar) Jul 1997

Midlands Institute For Non-Profit Management: Building A Solid Foundation, Center For Public Affairs Research (Cpar)

Publications

Agenda and material from the Midlands Institute for Non-Profit Management - Building a Solid Foundation Conference, July 7-11, 1997.

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Abundance Ratios In A Common Proper Motion Pair: Chemical Evidence Of Accreted Substructure In The Halo Field?, Jeremy R. King Jun 1997

Abundance Ratios In A Common Proper Motion Pair: Chemical Evidence Of Accreted Substructure In The Halo Field?, Jeremy R. King

Publications

Elemental abundances are presented for the metal-poor ([Fe/H] =-1.50) common proper motion pair HD 134439 and HD 134440. The abundances for the two stars are in very good agreement, with the neutral species showing only a small difference (˜0.05 dex) which is well within the statistical and Teff uncertainties. The essentially identical abundances, kinematics, and parallaxes of the two stars indicate that they share a common history. This history, however, appears to be different than other metal-poor stars. Suggestions, based on kinematic evidence, that these two-stars are representative of a distinct accretion event are corroborated by our abundance ratios, which …

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Numerical Simulations Of Gravity Waves Imaged Over Arecibo During The 10-Day January 1993 Campaign, Michael P. Hickey Ph.D., R. L. Walterscheid, Michael J. Taylor, William Ward, G. Schubert, Qihou Zhou, Francisco Garcia, Michael C. Kelly, G. G. Shepherd Jun 1997

Numerical Simulations Of Gravity Waves Imaged Over Arecibo During The 10-Day January 1993 Campaign, Michael P. Hickey Ph.D., R. L. Walterscheid, Michael J. Taylor, William Ward, G. Schubert, Qihou Zhou, Francisco Garcia, Michael C. Kelly, G. G. Shepherd

Publications

Recently, measurements were made of mesospheric gravity waves in the OI (5577 Å) nightglow observed from Arecibo, Puerto Rico, during January 1993 as part of a special 10-day campaign. Clear, monochromatic gravity waves were observed on several nights. By using a full-wave model that realistically includes the major physical processes in this region, we have simulated the propagation of two waves through the mesopause region and calculated the O(¹S) nightglow response to the waves. Mean winds derived from both UARS wind imaging interferometer (WINDII) and Arecibo incoherent scatter radar observations were employed in the computations as were the …

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The Circulating Processor Model Of Parallel Systems, Amy Apon, Lawrence Dowdy May 1997

The Circulating Processor Model Of Parallel Systems, Amy Apon, Lawrence Dowdy

Publications

This paper introduces the circulating processor model for parallel computer systems. The circulating processor model is a product form queuing network model where the processors are allowed to circulate between the parallel applications instead of the more traditional circulating task model. Certain behaviors of parallel systems are better captured using this new approach. The circulating processor model may be load dependent or load dependent. The load dependent circulating processor model is exact for systems which contain a single parallel application. An exact error is calculated for the load independent circulating processor model for systems which contain a single parallel application. …

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Lithium Abundances In The Solar Twins 16 Cyg A And B And The Solar Analog Alpha Cen A, Calibration Of The 6707 Angstrom Li Region Linelist, And Implications, Jeremy R. King, Constantine P. Deliyannis, Daniel D. Hiltgen, Alex Stephens, Katia Cunha, Ann Merchant Boesgaard May 1997

Lithium Abundances In The Solar Twins 16 Cyg A And B And The Solar Analog Alpha Cen A, Calibration Of The 6707 Angstrom Li Region Linelist, And Implications, Jeremy R. King, Constantine P. Deliyannis, Daniel D. Hiltgen, Alex Stephens, Katia Cunha, Ann Merchant Boesgaard

Publications

We present high resolution (R ˜45,000-70,000) and very high S/N (˜1,000) spectroscopy of the Li I 6707 Å region in each component of the binary solar twins 16 Cyg A and B, the solar analog alpha Cen A, and alpha Cen B. Spectra of 16 Cyg were obtained with the University of Hawai'i 2.2-m, McDonald Observatory 2.1-m, and Keck 10-m telescopes and have been independently reduced. Comparison of spectral synthesis and the 16 Cyg data, and corresponding similarly obtained solar data, yields 7Li abundances which show excellent concordance between the various data sets. Despite differing in Teff by only 35-40 …

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Constraints From 26al Measurements On The Galaxy's Recent Global Star Formation Rate And Core-Collapse Supernovae Rate, F. X. Timmes, R. Diehl, Dieter H. Hartmann Apr 1997

Constraints From 26al Measurements On The Galaxy's Recent Global Star Formation Rate And Core-Collapse Supernovae Rate, F. X. Timmes, R. Diehl, Dieter H. Hartmann

Publications

Gamma rays from the decay of 26Al o†er a stringent constraint on the GalaxyÏs global star formation rate over the past million years, supplementing other methods for quantifying the recent Galactic star formation rate, such as equivalent widths of Ha emission. Advantages and disadvantages of using 26Al gamma-ray measurements as a tracer of the massive star formation rate are analyzed. Estimates of the Galactic 26Al mass derived from COMPTEL measurements are coupled with a simple, analytical model of the 26Al injection rate from massive stars and restrict the GalaxyÏs recent star formation rate to 5^4 yr~1. In addition, we show …

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Uaa Student Showcase Journal: Recognizing Excellence (Spring 1997), N/A N/A Apr 1997

Uaa Student Showcase Journal: Recognizing Excellence (Spring 1997), N/A N/A

Publications

No abstract provided.

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The Larva, Pupa And Female Of Agapetus Jocassee Morse (Trichoptera: Glossosomatidae), Jason S. Craft, John C. Morse Apr 1997

The Larva, Pupa And Female Of Agapetus Jocassee Morse (Trichoptera: Glossosomatidae), Jason S. Craft, John C. Morse

Publications

Agapetus jocassee is a "Species of Concern" on the lists of the U.S.D.I. Fish and Wildlife Service because it is known from only three streams of the Lake Jocassee catchment in Oconee and Transylvania counties, South and North Carolina. To assist in solving identification problems and to contribute to knowledge of the distribution of this species, larvae and pupae of A. jocassee were collected from mountain streams in North and South Carolina, reared to adulthood and identified. The larva, pupa, and female of the species are described for the first time. Characters were found in those ontogenetic stages that distinguish …

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"Another Being We Have Created Called 'Us'": Point-Of-View, Melancholia, And The Joking Unconscious In The Bridges Of Madison County, Walter C. Metz Apr 1997

"Another Being We Have Created Called 'Us'": Point-Of-View, Melancholia, And The Joking Unconscious In The Bridges Of Madison County, Walter C. Metz

Publications

This essay reads Clint Eastwood's The Bridges of Madison County (1995) as a radical adaptation of Robert James Waller's novel. The piece uses three methods--close aesthetic analysis, Freudian melancholia theory, and Freudian joke theory--to unravel the films' deconstruction of Waller's lachrymose novel.

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"Keep The Coffee Hot, Hugo": Nuclear Trauma In Fritz Lang's The Big Heat (1953), Walter C. Metz Apr 1997

"Keep The Coffee Hot, Hugo": Nuclear Trauma In Fritz Lang's The Big Heat (1953), Walter C. Metz

Publications

This essay uses nuclear criticism, particularly Jacques Derrida's "No Apocalypse, Not Now" to read Fritz Lang's The Big Heat (1953) as a Cold War allegory concerned with the threat to civilization posed by atomic culture.

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Aboveground Production In Southeastern Floodplain Forests: A Test Of The Subsidy-Stress Hypothesis, William Conner, J Patrick Megonigal, Steven Kroeger, Rebecca R. Sharitz Mar 1997

Aboveground Production In Southeastern Floodplain Forests: A Test Of The Subsidy-Stress Hypothesis, William Conner, J Patrick Megonigal, Steven Kroeger, Rebecca R. Sharitz

Publications

It has been hypothesized that periodically flooded forests have higher rates of aboveground net primary production than upland forests and near-continuously flooded forests, but a competing hypothesis holds that the benefits of periodic inputs of nutrients and water may be diminished by stresses associated with anaerobic soils or drought. To test these hypotheses, we measured groundwater table depths and aboveground productivity in floodplain forests of South Carolina and Louisiana. We established paired plots on locally dry, intermediate, and wet topographic positions across three hydrologic transects in each state. These plots encompassed upland hardwood, bottomland hardwood, and cypress swamp forests. Measurements …

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Are Abell Clusters Correlated With Gamma-Ray Bursts?, Dieter H. Hartmann, K. Hurley, C. Kouveliotou, G. Fishman, J. Laros, T. Cline, M. Boer Feb 1997

Are Abell Clusters Correlated With Gamma-Ray Bursts?, Dieter H. Hartmann, K. Hurley, C. Kouveliotou, G. Fishman, J. Laros, T. Cline, M. Boer

Publications

A recent study has presented marginal statistical evidence that gamma-ray burst sources are correlated with Abell clusters, based on analyses of bursts in the BATSE 3B catalog. Using precise localization information from the 3rd Interplanetary Network, we have reanalyzed this possible correlation. We find that most of the Abell clusters which are in the relatively large 3B error circles are not in the much smaller IPN/BATSE error regions. We believe that this argues strongly against an Abell cluster–gamma–ray burst correlation.

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Technology And The Protection Of Intellectual Property, 1997 February, Clinton H. Whitehurst Jr. Feb 1997

Technology And The Protection Of Intellectual Property, 1997 February, Clinton H. Whitehurst Jr.

Publications

No abstract provided.

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Frequency Of Natural Hybridization Between Saugers And Walleyes In The Peoria Pool Of The Illinois River, As Determined By Morphological And Electrophoretic Criteria, Neil Billington, Ronald C. Brooks, Roy C. Heidinger Feb 1997

Frequency Of Natural Hybridization Between Saugers And Walleyes In The Peoria Pool Of The Illinois River, As Determined By Morphological And Electrophoretic Criteria, Neil Billington, Ronald C. Brooks, Roy C. Heidinger

Publications

External morphological characteristics and protein electrophoresis at two diagnostic loci were used to determine the proportion of 704 Stizostedion samples collected from the Peoria Pool of the Illinois River during March 1995 that were saugers S. canadense, walleyes S. vitreum, or their hybrids. Morphological analyses indicated that 616 (87.5%) fish were saugers, 58 (8.2%) were walleyes, and 30 (4.3%) were hybrids; electrophoretic analyses indicated that 625 (88.8%) fish were saugers, 50 (7.1%) were walleyes, and 29 (4.1%) were hybrids. Clear discrepancies between the morphological and electrophoretic analyses affected at least 43 (6.1%) fish. Only 2% of saugers were …

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High Levels Of A Major Histocompatibility Complex Ii-Self Peptide Complex On Dendritic Cells From The T Cell Areas Of Lymph Nodes, Kayo Inaba, Margit D. Witmer-Pack, Muneo M. Inaba Jan 1997

High Levels Of A Major Histocompatibility Complex Ii-Self Peptide Complex On Dendritic Cells From The T Cell Areas Of Lymph Nodes, Kayo Inaba, Margit D. Witmer-Pack, Muneo M. Inaba

Publications

T lymphocytes recirculate continually through the T cell areas of peripheral lymph nodes. During each passage, the T cells survey the surface of large dendritic cells (DCs), also known as interdigitating cells. However, these DCs have been difficult to release from the lymph node. By emphasizing the use of calcium-free media, as shown by Vremec et al. (Vremec, D., M. Zorbas, R. Scollay, D. J. Saunders, C.F. Ardavin, L. Wu, and K. Shortman. 1992. J. Exp. Med. 176:47-58.), we have been able to release and enrich DCs from the T cell areas. The DCs express the CD11c leukocyte integrin, the …

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Writing For Their Lives, John Strassburger Jan 1997

Writing For Their Lives, John Strassburger

Publications

This is the second in a series of occasional papers about the challenges confronting students and what Ursinus is doing to help them enter adult life.

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Whoever Heard Of Standardized Art? The Complexity Of Using Portfolios For Licensing Principals, Jane Clark Lindle Jan 1997

Whoever Heard Of Standardized Art? The Complexity Of Using Portfolios For Licensing Principals, Jane Clark Lindle

Publications

One dominant metaphor in the standards-based movement to "professionalize" teaching is that of art and artist. The images of "performance" and "portfolio" are constantly in use, and since these metaphors can lead to interesting insights, pushing them to their logical conclusions is the purpose of this paper. It draws on the extensive literature in art criticism and asks if a portfolio evaluation is an oxymoron. Portfolios have been suggested as desirable evaluation tools because they are open-ended and allow for individual interpretation and reflection. Evaluation, however, requires a common structure and externally imposed, standardized value judgments--conditions that are difficult to …

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Isotopic Carbon Abundances In M71, Michael M. Briley, Verne V. Smith, Jeremy R. King, David L. Lambert Jan 1997

Isotopic Carbon Abundances In M71, Michael M. Briley, Verne V. Smith, Jeremy R. King, David L. Lambert

Publications

High resolution echelle spectra of the 8005 Angstroms CN bands are presented for five bright giants in the globular cluster M71 (C1951 +186, NGC 6838). An analysis of the (13) CN feature included in this region confirms the results of \cite{briley94a}; that the M71 red giants evince low (12}C/({13)) C ratios and that these ratios are correlated with CN band strengths (CN-strong stars having lower (12}C/({13)) C ratios). This finding is consistent with the theory that the star-to-star CN band strength variations, as well as the oxygen and possibly sodium differences observed in M71, are related to the CN(O)-cycle of …

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