177,121 research outputs found
Data for: History of carbonate ion concentration over the last 100 million years II: Revised calculations and new data
No full textZeebe R. E and Tyrrell, T. History of carbonate ion concentration over the last 100 million years II: Revised calculations and new data. Geochim. Cosmochim. Acta, 2019.ZT19.CO3.datSurface Carbonate Ion concentration (global)Columns:Age(Ma) [CO32-](mumol/kg)ZT19.GCRB.datSurface Carbonate Chemistry Reconstruction (GEOCARB scenario)Columns:Age(Ma) [CO32-](mumol/kg) pCO2(muatm) DIC(mmol/kg) TA(mmol/kg) pHZT19.Alkn.datSurface Carbonate Chemistry Reconstruction (Alkenone scenario)Columns:Age(Ma) [CO32-](mumol/kg) pCO2(muatm) DIC(mmol/kg) TA(mmol/kg) pHSurface Carbonate Chemistry Reconstruction (d11B-pH scenario)ZT19.d11B.datColumns:Age(Ma) [CO32-](mumol/kg) pCO2(muatm) DIC(mmol/kg) TA(mmol/kg) p
Data for: History of carbonate ion concentration over the last 100 million years II: Revised calculations and new data
No full textZeebe R. E and Tyrrell, T. History of carbonate ion concentration over the last 100 million years II: Revised calculations and new data. Geochim. Cosmochim. Acta, 2019.ZT19.CO3.datSurface Carbonate Ion concentration (global)Columns:Age(Ma) [CO32-](mumol/kg)ZT19.GCRB.datSurface Carbonate Chemistry Reconstruction (GEOCARB scenario)Columns:Age(Ma) [CO32-](mumol/kg) pCO2(muatm) DIC(mmol/kg) TA(mmol/kg) pHZT19.Alkn.datSurface Carbonate Chemistry Reconstruction (Alkenone scenario)Columns:Age(Ma) [CO32-](mumol/kg) pCO2(muatm) DIC(mmol/kg) TA(mmol/kg) pHSurface Carbonate Chemistry Reconstruction (d11B-pH scenario)ZT19.d11B.datColumns:Age(Ma) [CO32-](mumol/kg) pCO2(muatm) DIC(mmol/kg) TA(mmol/kg) pHTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Palaeoclimatology of the late Palaeocene to middle Eocene: geochemical records of stable and transient climate states
No full textThe late Palaeocene to late Eocene period of Earth's history is characterised by remarkable change. Temperate ice free poles at the beginning of this period gradually cooled until permanent ice formed on Antarctica around 33.5 million years before present (Ma) and sea ice formed in the Arctic. The intervening time was not stable and data, despite relatively low resolution, appear to show that the Eocene climate was dynamic. This period was the most recent time when atmospheric pCO2 concentrations were as high as predicted by models simulating the effects of anthropogenic fossil fuel burning on Earths' climate. The ability to understand the mechanisms of climate change in the Eocene will help to understand potential climate impacts in the future. This thesis examines 3 contrasting periods of climate change. Geochemical data indicate that a 3.5 million year period of high biogenic silica deposition during the Eocene was climatically relatively stable in the Arctic basin with only infrequent communication to the world's oceans outside. This period is correlated with high organic burial in the basin and global siliceous rich deposits which acted to gradually draw down pCO2. This period of `quiet' climate compares to two periods of warming where significant carbon isotope perturbations may indicate the forcing of the Earth's climate into an alternative quasi-stable state. The Palaeocene { Eocene Thermal Maximum (PETM) represents a significant input of exogenic carbon into the atmosphere over the course of several thousand years and significant warming of the Earth. Records of bulk carbonate isotopes from a section in NE Italy show several other Delta13C perturbations both before and after the PETM event, albeit a quarter to a half of the magnitude of the PETM, and having durations of only 40 { 60 thousand years (kyr). These events are thought to be the result of a re-arrangement of the internal carbon cycle of the Earth - atmosphere and may represent orbitally forced changes in deep water ocean ventilation similar to controls seen on modern day glacial { interglacial cycles. These rapid changes in the carbon cycle are shown to be inverse at the middle Eocene Climatic Optimum (MECO), where gradual warming over 400 kyr is ended abruptly by significant cooling. From the first marginal marine section of this event rapid organic carbon burial occurs over 50 { 100 kyr and is associated with previously unrecorded low oxygen bottom water conditions and high organic burial. We hypothesize that if this burial was extended over significant shelf areas then this could rapidly have returned the middle Eocene to the general cooling trend of the Eocene
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
The 405 kyr and 2.4 Myr eccentricity components in Cenozoic carbon isotope records
No full textCenozoic stable carbon (δ13C) and oxygen (δ18O) isotope ratios of deep-sea foraminiferal calcite co-vary with the 405kyr eccentricity cycle, suggesting a link between orbital forcing, the climate system, and the carbon cycle. Variations in δ18O are partly forced by ice-volume changes that have mostly occurred since the Oligocene. The cyclic δ13C–δ18O co-variations are found in both ice-free and glaciated climate states, however. Consequently, there should be a mechanism that forces the δ13C cycles independently of ice-dynamics. In search of this mechanism, we simulate the response of several key components of the carbon cycle to orbital forcing in the Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir model (LOSCAR). We force the model by changing the burial of organic carbon in the ocean with various astronomical solutions and noise, and study the response of the main carbon cycle tracers. Consistent with previous work, the simulations reveal that low frequency oscillations in the forcing are preferentially amplified relative to higher frequencies. However, while oceanic δ13C mainly varies with a 405kyr period in the model, the dynamics of dissolved inorganic carbon in the oceans and of atmospheric CO2 are dominated by the 2.4Myr cycle of eccentricity. This implies that the total ocean and atmosphere carbon inventory is strongly influenced by carbon cycle variability that exceeds the time scale of the 405kyr period (such as silicate weathering). To test the applicability of the model results, we assemble a long (~22Myr) δ13C and δ18O composite record spanning the Eocene to Miocene (34 to 12Ma) and perform spectral analysis to assess the presence of the 2.4Myr cycle. We find that, while the 2.4Myr cycle appears to be overshadowed by long-term changes in the composite record, it is is present as an amplitude modulator of the 405 and 100kyr eccentricity cycles
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Liftings for noncomplete probability spaces
No full textThe current state of knowledge concerning liftings for noncomplete probability spaces is discussed. This is a somewhat expanded version of the author's talk given at the 1991 Summer Conference on General Topology and Applications in Honor of Mary Ellen Rudin and Her Work.PT: S; CR: BURKE MR, IN PRESS P AM MATH S BURKE MR, 1991, ISRAEL J MATH, V73, P33 BURKE MR, 1992, ISRAEL J MATH, V79, P289 CARLSON T, THEOREM LIFTING CHRISTENSEN JPR, 1974, TOPOLOGY BOREL STRUC FREMLIN DH, 1989, HDB BOOLEAN ALGEBRAS, P877 INOESCUTULCEA A, 1966, 5TH P BERK S MATH ST, V2 IONESCUTULCEA A, 1967, CONTRIBUTIONS PROB 1, P63 IONESCUTULCEA A, 1969, TOPICS THEORY LIFTIN JECH TJ, 1978, SET THEORY JOHNSON RA, 1980, P AM MATH SOC, V80, P234 JUST W, IN PRESS T AM MATH S KUPKA J, 1983, INDIANA U MATH J, V32, P717 LOSERT V, 1983, LNM, V1080, P95 MAHARAM D, 1958, P AM MATH SOC, V9, P987 SHELAH S, 1983, ISRAEL J MATH, V45, P90 TALAGRAND M, 1982, P AM MATH SOC, V84, P379 VONNEUMANN J, 1931, CRELLES J MATH, V165, P109; NR: 18; TC: 0; J9: ANN N Y ACAD SCI; PG: 4; GA: BZ86BSource type: Electronic(1
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