131,071 research outputs found
Raman cross section for the pentagonal-pinch mode in buckminsterfullerene C-60
No full textThe Raman cross section for the pentagonal pinch mode of C-60 at 1469 cm(-1) has been determined at a laser excitation wavelength lambda(L) = 752.5 nm. The experimental value, d sigma/d Omega = (2.09 +/- 0.29) x 10(-29) cm(2)/sr, is found to be in good agreement with predictions from an ab initio calculation based on density functional perturbation theory. A simple bond polarizability model with parameters obtained from hydrocarbon Raman measurements yields Raman intensities in C-60 within one order of magnitude of the experimental data
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
FIGURE 3. Speleonectes emersoni n in Speleonectes emersoni, a new species of Remipedia (Crustacea) from the Dominican Republic
No full textFIGURE 3. Speleonectes emersoni n. sp. from Dominican Republic, 12.5 mm holotype. A, frontal filaments (scale bar = 0.05 mm). B, antennule (scale bar = 0.3 mm). C, antenna. D, left mandible with enlarged lacinia mobilis and incisor process. E, enlarged incisor process (left) and lacinia mobilis (right) of right mandible. Scale bars C and D = 0.1 mm.Published as part of Lorentzen, Dörte, Koenemann, Stefan & Iliffe, Thomas M., 2007, Speleonectes emersoni, a new species of Remipedia (Crustacea) from the Dominican Republic, pp. 61-68 in Zootaxa 1543 on page 65, DOI: 10.5281/zenodo.17794
Speleonectes emersoni Lorentzen, Koenemann & Iliffe, 2007, new species
No full textSpeleonectes emersoni new species (Figs. 1–4) Type locality. Cueva Los Jardines Orientales, south coast near Santo Domingo, Dominican Republic. Material examined. Holotype (deposited at Biozentrum Grindel und Zoologisches Museum, Hamburg; catalogue number K - 41270) (12.5 mm, 21 trunk segments), five paratypes (9.5 mm, 19 trunk segments; 10.5 mm, 20 trunk segments; 11 mm, 20 trunk segments; 11 mm, 20 trunk segments; 11.5 mm, 20 trunk segments; all in research collection of SK) from Cueva Los Jardines Orientales. One paratype (10 mm, 20 trunk segments) from Cueva Taina. Specimens were collected on May 1, 2005 (Cueva Taina) and May 5, 2005 (Cueva Los Jardines Orientales) at or below the halocline in 15–37 m depth by Thomas Iliffe. The holotype and one paratype (whole specimens) are preserved in alcohol; two paratypes were dissected and preserved in glycerine; three paratypes were used for molecular analyses. Etymology. The epithet emersoni is in honor of the biologist Michael James Emerson (8 May 1954 – 22 March 1990). Michael worked as a research assistant on the “Remipede Project” at the San Diego Natural History Museum from 1982 to 1990. His experience as a skillful scientific illustrator and attentive observer resulted in several publications that set benchmarks in the systematics of Remipedia. Diagnosis. A small-sized, slender species, up to 12.5 mm, adult specimens composed of 19–21 segments; pleural tergites weakly developed, with rounded lateral margins in anterior part of trunk, becoming slightly pointed in posterior trunk; dorsal ramus of antennule 11 -segmented, ventral ramus with 6 segments; arcshaped, horseshoe-like claw of maxilla and maxilliped composed of 7–10 denticles; anal segment longer than wide; caudal rami approximately as long as anal segment. Description. Based on holotype and paratypes. Body slender with a maximum length of 12.5 mm and 21 trunk segments (Fig. 1). Pleural tergites narrow, with rounded distolateral corners on trunk segments 1–7 (Figs. 1, 2 A), becoming slightly acuminate in posterior part of trunk, tergite on first trunk segment reduced. Sternal bars sublinear and isomorphic. Male gonopores on trunk limb 14 cylindrical, with rounded pointed lobes (Fig. 2 B). Head shield subrectangular, tapering at anterior end, approximately as long as trunk segments 1–3 (Fig. 2 A). Frontal filaments with relatively short distomedial processes, extending beyond tip of main filament (Fig. 3 A). Antennule (Fig. 3 B): Peduncle with small bulbus bearing relatively few aesthetascs. Dorsal flagellum 11 - segmented, almost twice as long as head shield, reaching 9 % of length of body. Ventral flagellum with 6 segments, nearly half as long as dorsal flagellum, as long as head shield. Antenna (Fig. 3 C): Proximal segment of protopod with 2 marginal setae; distal segment with 4 marginal setae. Exopod longer and wider than adjacent distal segment of protopod, bearing 18–20 long setae. Endopod bent in a semicircular arc; first two proximal segments with 5–6 and 4–5 setae, respectively; distal segment with about 15 setae arranged in two rows composed of 9 and 5–6 setae. All setae faintly plumose. Mandible (Fig. 3 D, E): Right incisor process and lacinia mobilis with three large denticles. Left incisor process with four large denticles; left lacinia mobilis crescent-shaped, apical margin serrate. Molar process prominent. Maxillule (Fig. 4 A, D, E): Segment 1 with slender endite, distal margin terminating in 4 long stout setae (one of which prominent) and about 3 simple setae. Endite of second segment long and broad, with 2 setae at inner proximal margin; 6 stout, relatively large setae (all of which simple, except one setulose seta (Fig. 4 E)) and 5–6 fine setae arranged in a second row on distomedial and -lateral margins and two long setae on distolateral margin. Segment 3 short; endite tapering, slightly rounded, bearing 2 long, robust setulose setae and 1 simple seta. Segment 4 (lacertus) subtriangular, with obliquely expanded medial margin; proximal corner bearing 2 long, robust setae (Fig. 4 D) and 4–5 simple setae. Segment 5 as long as lacertus, but narrower, with a cluster of distomedial setae. Sixth segment equipped with separate clusters of long and shorter setae on distal margins. Claw slender, well-developed (Fig. 4 A). Maxilla (Fig. 4 B): First endite of segment 1 bearing 2 short apical stout setae. Endites 2 and 3 of first segment each with 1 prominent apical stout seta accompanied by 2–4 short setae on subapical margins. Endite of segment 2 equipped with a single, short stout seta and a few long setae. Segment 3 (lacertus) slightly pearshaped, medial margin bearing 4–6 long and short setae. Segment 4 shorter than segment 3; distomedial margin rounded, with a cluster of 2–3 setae. Segment 5 shorter than segment 4, subquadrangular; distomedial corner with a cluster of 5 long and shorter setae. Segment 6 nearly as long as segment 5, with a row of about 7 setae along distomedial margin and a row of about 6 setae on distoposterior margin. Arc-shaped, horseshoetype claw serrated, composed of 7–10 small denticles flanked by 2 stronger, separate denticles. All setae simple. Maxilliped (Fig. 4 C, F): Distinctly longer than maxillule, slender. Segments 1 and 2 bearing a few long medial setae. Segment 3 rather long, with 4 long setae. Segments 4–6 gradually decreasing in length; fourth segment with a row of 4 medial setae. Segment 5 with distomedial margin slightly expanded bearing 2 long setae. Segment 6 bearing 2 setae on distomedial margin. Segment 7 subquadrangular, with a row of about 6 long and shorter setae at distomedial margin. Eighth segment approximately as long as segment 7, equipped with a row of about 13 setae at distomedial margin and 7 short setae on distolateral margin. Claw subequal to that of maxilla (Fig. 4 F). All setae simple. Trunk appendages (Fig. 2 B, D): Segment 1 of exopod equipped with 3–6 long setae and up to 2 serrate stout setae on distolateral corner. Segment 2 with setae on lateral and medial margins, and 3–4 serrate stout setae on distolateral corner. Segment 3 ovate, bearing 14–17 long marginal setae. Endopod slightly shorter and narrower than exopod; distribution of long plumose setae like those on exopod, with the following exceptions: basal segment naked; segment 3 with 2 serrate stout setae on distolateral corner and 1 serrate stout setae on distomedial corner; segment 4 with 10–12 setae (Fig. 2 B). All setae plumose. Anal segment (Fig. 2 C): 1.2 times longer than wide; caudal rami about 1.1 times longer than anal segment, bearing a few very fine setae along margins and about 3 fine, apical setae.Published as part of Lorentzen, Dörte, Koenemann, Stefan & Iliffe, Thomas M., 2007, Speleonectes emersoni, a new species of Remipedia (Crustacea) from the Dominican Republic, pp. 61-68 in Zootaxa 1543 on pages 62-67, DOI: 10.5281/zenodo.17794
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
"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.
Raman cross section for the pentagonal-pinch mode in buckminsterfullerene C-60
No full textThe Raman cross section for the pentagonal pinch mode of C-60 at 1469 cm(-1) has been determined at a laser excitation wavelength lambda(L) = 752.5 nm. The experimental value, d sigma/d Omega = (2.09 +/- 0.29) x 10(-29) cm(2)/sr, is found to be in good agreement with predictions from an ab initio calculation based on density functional perturbation theory. A simple bond polarizability model with parameters obtained from hydrocarbon Raman measurements yields Raman intensities in C-60 within one order of magnitude of the experimental data
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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
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