177,176 research outputs found
Extinction debt for plants and flower-visiting insects in landscapes with contrasting land use history
No full textAim Species are lost world-wide because of habitat destruction and fragmentation. Impacted communities can exhibit transient dynamics in response to such environmental changes, where slow extinctions and immigration delay the arrival to a new equilibrium. Life history traits such as generation time, resource use and dispersal capacity, as well as landscape history can be expected to affect possible extinction debt, but few have examined this for multiple taxa in the same study and particularly so for arthropods. The aim was to assess under which current and historical land use circumstances an extinction debt occurs for vascular plants and three insect taxa. Location South-eastern Sweden. Method We sampled current species richness of habitat specialist and generalist butterflies, bees, hoverflies, and vascular plants in 45 dry to mesic semi-natural grassland fragments of various size and degree of connectivity, and situated in landscapes with contrasting land use conversion history. Habitat loss was estimated in each landscape by comparing modern maps to ~45year old digitized aerial photographs. An extinction debt can be assumed if historical habitat size and connectivity better explain current species distribution than current habitat variables do. Results Bees responded rapidly to habitat loss possibly as a result of their primary nesting resource being destroyed. Interestingly, species richness of specialist plants was best explained by historical habitat connectivity, richness of hoverflies by historical habitat area, and richness of butterflies by both historical habitat area and connectivity, indicating extinction debt for these taxa. Habitat generalist butterflies and hoverflies, but not plants and bees, exhibited extinction debt mainly in relation to habitat area. No effect of landscape type was found on the observed extinction debt. Main conclusions Slow extinctions of persistent and long-lived plants might explain extinction debt for both plants and herbivorous insects linked to these plants.</p
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
Numerical identification of fast structural growth in stratified turbulence
No full textWe investigate a type of instability observed in the presence of two counter rotating vortex
columns in a highly stratfied
fluid, Fr < 1. This instability causes the vortex columns
to be bent and stretched out in the horizontal direction eventually leading to discrete
horizontal layers of vorticity. The instability is known as the zigzag instability and causes
exponential growth in total enstrophy which stops once viscous dissipation becomes im-
portant. We find that two counter rotating vortex columns with localised perturbations
applied parallel to the direction of propagation and offset from one another between the
two columns is an initial profile that is highly unstable to the zigzag instability leading
to exponential enstrophy growth faster than any prior numerical simulations have shown
however is consistent in timing with a previous experimental result. We show that the
zigzag instability that develops on these vortex columns provides a mechanism for energy
(kinetic and potential) to cascade from large scales to small scales
"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
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
Hansen, Lee (Lee R.). Union, non-union, and managerial pay plan state employees, 2008-2019
No full text1 online resource (2 pages)"July 1, 2021."Provides the number of union and non-union state employees in each of the last 14 years. Also provides the number of state employees paid under the state's managerial pay plan during each of those years. Updates OLR research report 2019-R-011
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