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Articles 4501 - 4530 of 5031

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Changing The River’S Course: Western Water Policy Reform, David H. Getches Jan 1996

Changing The River’S Course: Western Water Policy Reform, David H. Getches

Publications

Throughout the history of the West, water law and policy have had a profound influence on the environment of the region. Power production, agricultural irrigation, and economic expansion of the Columbia River Basin have depended upon the institutions of water policy, including the prior appropriation doctrine and major water development in the form of large dams and diversions. This has rendered the river incapable of sustaining the rich salmon populations that once were the mainstay of Northwest Indian culture and supported a major fishing industry. Professor Getches concludes that traditional instruments of water policy in the West--the beneficial use requirement …

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The Relationship Between The Soil Seed Bank And Above-Ground Vegetation Of A Coastal Barrier Island, Paul B. Looney, David J. Gibson Dec 1995

The Relationship Between The Soil Seed Bank And Above-Ground Vegetation Of A Coastal Barrier Island, Paul B. Looney, David J. Gibson

Publications

The germinable soil seed bank is described from a coastal barrier island off the northwest coast of Florida, USA. Soil samples collected from seven vegetation types, recently deposited dredge spoil and unvegetated areas in autumn 1990 and spring 1991 were placed out in greenhouse trays. 110 taxa germinated from the samples with the largest number (41) being C3 perennial dicots. The largest number of taxa germinated from dry (57) and wet (54) swales, the fewest (one species: Heterotheca subaxillaris) from strand. Similarity of seed bank densities to above-ground species cover was low (Jaccard’s Index = 0.36), not different between …

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Reviewed Work(S): Antonio Skármeta And The Post Boom By Donald Shaw, Salvador Oropesa Nov 1995

Reviewed Work(S): Antonio Skármeta And The Post Boom By Donald Shaw, Salvador Oropesa

Publications

No abstract provided.

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Evidence Of Higher Primordial Lithium From Keck Observations Of M92, Constantine P. Deliyannis, Ann Merchant Boesgaard, Jeremy R. King Oct 1995

Evidence Of Higher Primordial Lithium From Keck Observations Of M92, Constantine P. Deliyannis, Ann Merchant Boesgaard, Jeremy R. King

Publications

Knowledge of the primordial lithium abundance (Lip) tests and constrains models of big bang nucleosynthesis and may have implications for dark matter and the laws of physics. An apparent small dispersion in the Li abundances of field halo dwarfs had been predicted to result from differences in the Li depletion of models with rotationally induced mixing, and would imply a higher Lip than is observed today in these stars. However, this dispersion could also be explained by differential Galactic Li enrichment (from lower Lip) coupled with a halo age spread and/or incomplete mixing. To differentiate between these possibilities, we have …

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A New Interpretation Of 26al In Meteoritic Inclusions, Donald D. Clayton, Liping Jin Oct 1995

A New Interpretation Of 26al In Meteoritic Inclusions, Donald D. Clayton, Liping Jin

Publications

We suggest that the large 26Al/27Al ϭ 5 ϫ 10Ϫ5 abundance ratio found in calcium-aluminum–rich inclusions (CAIs) in meteorites is produced by energetic particle irradiation in the early solar system but only in a thin (0.2 g cmϪ2) skin of the solar preplanetary disk that stops the energetic particles. Buildup of that 26Al concentration happens only during the quiescent, or passive, phase of the solar disk, after accretion and associated turbulence has ceased. We propose that CAIs also originate in the form of fine Al-rich dust within a coronal-type environment atop the disk. In this model only the CAIs among …

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Gamma Rays, Cosmic Rays, And Extinct Radioactivity In Molecular Clouds, Liping Jin, Donald D. Clayton Oct 1995

Gamma Rays, Cosmic Rays, And Extinct Radioactivity In Molecular Clouds, Liping Jin, Donald D. Clayton

Publications

No abstract provided.

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Limited Wars, Civilian Casualties, And Who Must Decide, 1995 September 26, Clinton H. Whitehurst Jr. Sep 1995

Limited Wars, Civilian Casualties, And Who Must Decide, 1995 September 26, Clinton H. Whitehurst Jr.

Publications

No abstract provided.

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"The Sacred Rights Of The Weak": Pain, Sympathy, And The Culture Of Individual Rights In Antebellum America, Elizabeth B. Clark Sep 1995

"The Sacred Rights Of The Weak": Pain, Sympathy, And The Culture Of Individual Rights In Antebellum America, Elizabeth B. Clark

Publications

In 1835 an antislavery sympathizer leaving a lecture by Theodore Dwight Weld went home to dream that she was transported above the world; looking down at the United States, she saw "multitudes of sable figures, bending beneath a scorching sun -- their backs lacerated by the whip -- scourged, maimed, loaded with irons -- subject to every insult -- and exposed to every gust of unbridled passions." The dreamer, a Mrs. Sturges, drew from many discourses in describing her lengthy dream, but the fundamental trope of her visionary narrative was the story of the suffering slave, a trope that in …

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New Sources For The Hot Oxygen Geocorona: Solar Cycle, Seasonal, Latitudinal, And Diurnal Variations, Michael P. Hickey Ph.D., P. G. Richards, D. G. Torr Sep 1995

New Sources For The Hot Oxygen Geocorona: Solar Cycle, Seasonal, Latitudinal, And Diurnal Variations, Michael P. Hickey Ph.D., P. G. Richards, D. G. Torr

Publications

This paper demonstrates the variability of thermospheric sources of hot oxygen atoms. Numerical calculations were performed for day and night, high and low solar activity, summer and winter, and low- and middle-latitude conditions. Under most conditions, reactions involving metastable species are more important hot O sources than previously considered dissociative recombination of O2+ and NO+. All the hot O sources are an order of magnitude lower at midnight than at noon. At night, dissociative recombination of O2+and NO+ are the most important sources. Quenching of vibrationally excited N2 (N2*) by O is the most important metastable source at night. Above …

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Carbon And Nitrogen Isotopes In Type Ii Supernova Diamonds, Donald D. Clayton, B S. Meyer, Chris Sanderson, Sara S. Russell, C T. Pillinger Jul 1995

Carbon And Nitrogen Isotopes In Type Ii Supernova Diamonds, Donald D. Clayton, B S. Meyer, Chris Sanderson, Sara S. Russell, C T. Pillinger

Publications

We construct a model for the origin of the abundant nanometer diamonds found in meteorites. We interpret them as interstellar particles that were grown during the expansions of supernova interiors. The physical setting and the chemical-vapor-deposition process that we describe present clear reasons both for the small sizes (nm) of the diamonds and for their mean isotopic composition being not greatly different from solar. To delineate the isotopic requirements for collections of diamonds (which are too small for analysis individually) we present measurements of carbon and nitrogen isotopes obtained by stepped combustion of diamond collections. Our model for the growth …

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The Effects Of Pure Density Evolution On The Brightness Distribution Of Cosmological Gammy-Ray Bursts, J. M. Horack, A. G. Emslie, Dieter H. Hartmann Jul 1995

The Effects Of Pure Density Evolution On The Brightness Distribution Of Cosmological Gammy-Ray Bursts, J. M. Horack, A. G. Emslie, Dieter H. Hartmann

Publications

In this work, we explore the effects of burst rate denisty evolution on the observed brightness distribution of cosmological gamma-ray bursts. Although the brightness distribution of gamma-ray bursts observed by the BATSE experiment has been shown to be consisitent with a nonevoloving soruce population observed to redshifts of order unity, evolution of some form is likely to be present in the gamma-ray bursts. Additionally nonevolving models place significant constraints on the range of observed burst luminosities, which are relaxed if evolution of the burst population is present. In this paper, three analytic forms of density evolution are examined. In general, …

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Massive Supernovae, Orion Gamma Rays, And The Formation Of The Solar System, Donald D. Clayton, A.G.W. Cameron, P. Hoflich, P C. Myers Jul 1995

Massive Supernovae, Orion Gamma Rays, And The Formation Of The Solar System, Donald D. Clayton, A.G.W. Cameron, P. Hoflich, P C. Myers

Publications

We discuss the source of the enhanced carbon and oxygen low-energy cosmic-ray flux in the Orion star-forming region and attribute it to the acceleration of the surface layers of a massive supernova, probably of Type Ib. The gamma rays from Orion are produced by that fast CO ejecta. In this model there would be few Orion-like gamma-ray sources in the Galaxy at any one time. We also postulate that a massive supernova produced the short-lived extinct radioactivities injected into the molecular cloud core that produced the solar system. We find that relative to 26Al the other short-lived extinct radioactivities are …

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Deep Optical Counterpart Searches Of Gamma-Ray Burst Localizations, Frederick J. Vrba, Dieter H. Hartmann, Mark C. Jennings Jun 1995

Deep Optical Counterpart Searches Of Gamma-Ray Burst Localizations, Frederick J. Vrba, Dieter H. Hartmann, Mark C. Jennings

Publications

We report the results of a 5 year CCD imaging program of small gamma-ray burst (GRB) error boxes from the First Interplanetary Network and an optical transient field. The fields include GBS 0010 - 16, GBS 0552-08, GBS 1028 + 46, GBS 1205 + 23, GBS 1412 + 79, OTS 1809 + 31, GBS 2006 - 22, and GBS 2252 - 03. A total of 274 hours of open shutter time was used to obtain multiple UBVI-filtered frames covering an area approximately twice that of the 99% confidence localizations. For 2070 objects in these fileds above the survey detection limit …

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Cgro/Osse Observations Of The Cassiopeia A Supernova Remnant, Lih-Sin The, M D. Leising, Donald D. Clayton, W N. Johnson, R L. Kinzer, J D. Kurfess, M S. Strickman, G V. Jung, D A. Grabelsky, W R. Purcell May 1995

Cgro/Osse Observations Of The Cassiopeia A Supernova Remnant, Lih-Sin The, M D. Leising, Donald D. Clayton, W N. Johnson, R L. Kinzer, J D. Kurfess, M S. Strickman, G V. Jung, D A. Grabelsky, W R. Purcell

Publications

Cas A, the youngest known supernova remnant in the Galaxy and a strong radio and Xray source, was observed by OSSE July 16 - August 6, 1992. Its close distance (¸ 3 kpc) and its young age (¸ 300 yrs) make Cas A the best candidate among known supernova remnants for detecting 44 Ti fl-ray lines. We find no evidence of emission at 67.9 keV, 78.4 keV, or 1.157 MeV, the three strongest 44 Ti decay lines. From simultaneous fits to the three lines our 99% confidence upper limit to the flux in each line is 5.5Theta10 Gamma5 fl cm …

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Uaa Student Showcase Journal: Recognizing Excellence (Spring 1995), N/A N/A Apr 1995

Uaa Student Showcase Journal: Recognizing Excellence (Spring 1995), N/A N/A

Publications

No abstract provided.

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26al And 60fe From Supernova Explosions, F. X. Timmes, S. E. Woosley, Dieter H. Hartmann, R. D. Hoffman, T. A. Weaver, F. Matteucci Apr 1995

26al And 60fe From Supernova Explosions, F. X. Timmes, S. E. Woosley, Dieter H. Hartmann, R. D. Hoffman, T. A. Weaver, F. Matteucci

Publications

Using recently calcualted yields from Type II supernovae, along with models for chemical evolution and the distribution of mass in the interstellar medium, the current abundances and spatial distribution of mass in the interstellar medium, the current abundances and spatial distributions of two key gamma-ray radiactivites, 26Al and 60Fe, and determined. The estimated steady state production rates are 2.0±1.0 M☉ Myr^-1 for 26Al and 0.75±0.4 M☉ Myr^-1 for 60 Fe. This corresponds to 2.2±1.1 M☉ of 26Al and 1.7±0.9 M☉ of 60Fe in the present interstellar medium. Sources of uncertainty are discussed, one of the more important being the current …

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Fetching The Jingle Along: Mark Twain's Slovenly Peter, Susanna Ashton Apr 1995

Fetching The Jingle Along: Mark Twain's Slovenly Peter, Susanna Ashton

Publications

No abstract provided.

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Do Gamma-Ray Burst Sources Repeat?, Charles A. Meegan, Dieter H. Hartmann, J. J. Brainerd, Michael S. Briggs, William S. Pacicsas, William S. Pacicsas, Geofrey Pendleton, Chryssa Kouveliotou, Gerald Fishman, George Blumenthal Mar 1995

Do Gamma-Ray Burst Sources Repeat?, Charles A. Meegan, Dieter H. Hartmann, J. J. Brainerd, Michael S. Briggs, William S. Pacicsas, William S. Pacicsas, Geofrey Pendleton, Chryssa Kouveliotou, Gerald Fishman, George Blumenthal

Publications

The demonstration of repeated gamma-ray bursts from an individual sourch would severely constrain burst source models. Recent reports (Quashnock & Lamb 1993; Wang & Lingenfelter 1993) of evidence for repetition in the first BATSE burst catalog have generated renewed interest in this issue. Here, we analyze the angular distribution of 585 bursts of the second BATSE catalog (Meegan et al. 1994). We search for evidence of burst recurrence using the nearest and farthest neighbor statistic and the two-point angular correlation function. We find the data to be consistent with the hypothesis that burst sources do not repeat; however, a repeater …

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Batse Observations Of The Large-Scale Isotropy Of Gamma-Ray Bursts, Dieter H. Hartmann, Michael S. Briggs, William S. Paciesas, Geoffrey N. Pendleton, Charles A. Meegan, Gerald J. Fishman, John M. Horack, Martin N. Brock, Chryssa Kouveliotou, Jon Hakkila Mar 1995

Batse Observations Of The Large-Scale Isotropy Of Gamma-Ray Bursts, Dieter H. Hartmann, Michael S. Briggs, William S. Paciesas, Geoffrey N. Pendleton, Charles A. Meegan, Gerald J. Fishman, John M. Horack, Martin N. Brock, Chryssa Kouveliotou, Jon Hakkila

Publications

We use dipole and quadrupole statistics to test the large-scale isotropy of the first 1005 gamma-ray bursts observed by the Burst and Transient Source Experiment (BATSE). In addition to the entire sample of 1005 gamma-ray bursts, many subsets are examined. We use a variety of dipole and quadrupole statistics to search for Galactic and other predicted anisotropies and for anisotropies in a coordinate-system independent manner. We find the gamma-ray burst locations to be consistent with isotropy, e.g., for the total sample the observed Galactic dipole moment cosθ differs from the value predicted for isotropy by 0.9σ and the observed Galactic …

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Western Australia's Place In A Global Economy: A Logistics Point Of View, 1995 February 21, Clinton H. Whitehurst Jr. Feb 1995

Western Australia's Place In A Global Economy: A Logistics Point Of View, 1995 February 21, Clinton H. Whitehurst Jr.

Publications

No abstract provided.

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Parallel Analysis: A Method For Determining Significant Principal Components, Scott B. Franklin, David J. Gibson, Philip A. Robertson, John T. Pohlmann, James S. Fralish Feb 1995

Parallel Analysis: A Method For Determining Significant Principal Components, Scott B. Franklin, David J. Gibson, Philip A. Robertson, John T. Pohlmann, James S. Fralish

Publications

Numerous ecological studies use Principal Components Analysis (PCA) for exploratory analysis and data reduction. Determination of the number of components to retain is the most crucial problem confronting the researcher when using PCA. An incorrect choice may lead to the underextraction of components, but commonly results in overextraction. Of several methods proposed to determine the significance of principal components, Parallel Analysis (PA) has proven consistently accurate in determining the threshold for significant components, variable loadings, and analytical statistics when decomposing a correlation matrix. In this procedure, eigenvalues from a data set prior to rotation are compared with those from a …

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The Ss William Lawrence: The Builders, Owners And Wrecking Account, Lynn Harris Feb 1995

The Ss William Lawrence: The Builders, Owners And Wrecking Account, Lynn Harris

Publications

This 30 page document presents information regarding the shipbuilder and ownership of the SS William Lawrence and newspaper reports of its wrecking.

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Four Cases Of Acoustic Neuromas With Normal Hearing, Michael Valente, Judy Peterin, Joel Goebel, J. Gail Neely Jan 1995

Four Cases Of Acoustic Neuromas With Normal Hearing, Michael Valente, Judy Peterin, Joel Goebel, J. Gail Neely

Publications

No abstract provided.

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The Endoeytie Activity Of Dendritic Cells, Ralph M. Steinman, Joel A. Swanson Jan 1995

The Endoeytie Activity Of Dendritic Cells, Ralph M. Steinman, Joel A. Swanson

Publications

[No abstract available]

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Low Levels Of Hiv-1 Infection In Cutaneous Dendritic Cells Promote Extensive Viral Replication Upon Binding To Memory Cd4+ T Cells, Melissa Pope, Stuart Gezelter, Nancy Gallo Jan 1995

Low Levels Of Hiv-1 Infection In Cutaneous Dendritic Cells Promote Extensive Viral Replication Upon Binding To Memory Cd4+ T Cells, Melissa Pope, Stuart Gezelter, Nancy Gallo

Publications

Earlier work has identified a cell population that replicates HIV-1 in the absence ofstandard T cell stimuli. The system consists of dendritic cells and memory T lymphocytes that emigrate from organ cultures of human skin and together support a productive infection with HIV-1. These emigrants resemble cells that can be found in mucous membranes and that normally traffic in afferent lymph. Here, we report that a low level of infection in the dendritic cell can initiate extensive HIV-1 replication in cocultures with T cells. First we extended our earlier work to larger skin specimens from cadavers. As long as the …

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Both Dendritic Cells And Memory T Lymphocytes Emigrate From Organ Cultures Of Human Skin And Form Distinctive Dendritic-T-Cell Conjugates, Melissa Pope, Michael G.H. Betjes, Haideh Hirman Jan 1995

Both Dendritic Cells And Memory T Lymphocytes Emigrate From Organ Cultures Of Human Skin And Form Distinctive Dendritic-T-Cell Conjugates, Melissa Pope, Michael G.H. Betjes, Haideh Hirman

Publications

Prior studies of mouse skin in organ culture have shown that dendritic cells selectively emigrate from the explants over 1-3 d. This emigration may model the movements of dendritic cells that can occur in situ, as in transplantation and contact sensitivity. In this study, we cultured explants of normal human skin that had been removed with a dermatome. Dendritic cells with characteristic morphology and mixed leukocyte response-stimulatory activity emigrated. The dendritic cells had the expected phenotype, e.g., rich in major histocompatibility complex class II and accessory molecules such as B7-1, intercellular adhesion molecule-1, and leukocyte function-associated antigen-3. Small lymphocytes also …

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Recognition Of Speech In Noise With Hearing Aids Using Dual Microphones, Michael Valente, David Fabry, Lisa G. Potts Jan 1995

Recognition Of Speech In Noise With Hearing Aids Using Dual Microphones, Michael Valente, David Fabry, Lisa G. Potts

Publications

No abstract provided.

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Stellar Oxygen Abundances. Iv: Systematic Effects On Oxygen Abundances Derived From The 6300 A (O I) And 7774 A O I Lines, Jeremy R. King, Ann Merchant Boesgaard Jan 1995

Stellar Oxygen Abundances. Iv: Systematic Effects On Oxygen Abundances Derived From The 6300 A (O I) And 7774 A O I Lines, Jeremy R. King, Ann Merchant Boesgaard

Publications

We consider potential systematic effects on oxygen abundances derived from the 6300 A (OI) line and the 7774 A OI triplet. Our solar intensity spectra of the 7774 A triplet confirm previous results which indicate a discrepancy between the observed equivalent widths of Altrock (1968) and the values predicted by Local Thermodynamic Equilibrium (LTE) and recent NLTE models. However, this disagreement (at low micron(s)) does not seem to affect the solar O abundance as derived from flux spectra. We derive O abundances for a selection of relatively metal-rich F and G dwarfs from both the 6300 A (OI) line and …

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Rethinking Ancestors In Africa, John C. Mccall Jan 1995

Rethinking Ancestors In Africa, John C. Mccall

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No abstract provided.

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Journal Of The Community Development Society Vol. 26, No. 02, Center For Public Affairs Research (Cpar) Jan 1995

Journal Of The Community Development Society Vol. 26, No. 02, Center For Public Affairs Research (Cpar)

Publications

An important function of the Journal of the Community Development Society is to report on research conducted in the field of community development. In particular the research that we report in this journal should have research questions that pertain to the theory and practice of purposive community change. One of the more critical tasks of journal editors, then, is to ensure that proposed articles in fact have appropriate, clear, and relevant research questions. A research question, however, is a multi-faceted creature. As many of us recall from our introductory courses in research methods, there are actually three types of research …

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