118,075 research outputs found
Helobdella eriensis Saglam & Kutschera & Saunders & Saidel & Balombini & Shain 2018, n. sp.
No full textHelobdella eriensis n. sp. (FPWS 2-Farm Pond) (Figs. 2 D-7D) (Holotype: ANSP GI 19494) (LSID: urn:lsid:zoobank.org:act:91CD93B2-3B58-42C9-B640-9C92FD8827CC)— Dorsal body light to yellowish-grey, sometimes with greenish tint. Ventral same as H. serendipitious n. sp. Total of 67 annul; I, II, III uniannulate, IV, V biannulate, VI-XXIII triannulate, XXV biannulate, XXVI-XXVII uniannulate. One pair of small, elliptical eyes clearly separated on segment III (Fig. 7D). Male and female gonopores between XI a2/a3 (24th/25th annuli) and XIa3/XIIa1 (25th/26th annuli), respectively; clitellum between XI-XIIth segments. Six pairs of testisacs intersegmentally arranged, located as in H. modesta. Ejaculatory bulbs similar to H. stagnalis, Ovisacs in XII segment large, connected with long and curled common oviduct. Oviduct shorter than ovisac (Figs. 2D, 4D). Six pairs of crop caeca, 6th directed backwards and short extending up to fourth intestinal caecum. Four pairs of intestinal caecum, first three curved slightly upward and fourth curved downward. Rectum is long with twisted “S” shape (Figs. 3D, 5D).Published as part of Saglam, Naim, Kutschera, Ulrich, Saunders, Ralph, Saidel, William M., Balombini, Katherine L. W. & Shain, Daniel H., 2018, Phylogenetic and morphological resolution of the Helobdella stagnalis species-complex (Annelida: Clitellata: Hirudinea), pp. 61-86 in Zootaxa 4403 (1) on page 70, DOI: 10.11646/zootaxa.4403.1.3, http://zenodo.org/record/121223
Helobdella serendipitious Saglam & Kutschera & Saunders & Saidel & Balombini & Shain 2018, n. sp.
No full textHelobdella serendipitious n. sp. (Figs. 2C – 7C) (Holotype: ANSP GI 19495) (LSID: urn:lsid:zoobank.org:act:D2A31CAB-F69D-413A-AD52-1497 EB146753)— Adult 11.2–20.3 mm long, 4.5–5.2 mm wide, width of anterior sucker 1.2–2.4 mm, width of posterior sucker 2.0– 3.6 mm. Dorsal body light to yellowish-grey, sometimes with greenish tint. Ventral color containing mixed translucent creamy and browngreenish spots. Total of 66 annuli; I, II, III uniannulate, IV, V biannulate, VI-XXIII triannulate, XXIV biannulate XXV-XXVII uniannulate. One pair of large circular eyes clearly separated on segment III (Fig. 7C). Gonopores located between XI a1/a2 (23th/24th annulus) and XI a2/a3 (24th/25th annulus), respectively. Clitellum on 11th segment. Six pairs of ovoidal, irregular and amorphous testisacs inter-segmentally arranged on XII/XIII–XVII/ XVIII. Ejaculatory bulbs moderately longer, elongated ellipsoid, lying at much lower level by the sides of the atrium, connected by slender ejaculatory ducts with sharp turn backwards into atrium in XI. Ovisacs large, connected with long and curled common oviduct. Length of ovisacs and oviduct almost equal. Ovisac and oviduct 2/3 the length of vas deferens (Figs. 2C, 4C). Crop caeca comprising six unbranched pairs. Four pairs thick intestinal caecum curved downward in first and fourth pairs. Rectum short, “S” shaped and similar to that of H. stagnalis. (Figs. 3C, 5C).Published as part of Saglam, Naim, Kutschera, Ulrich, Saunders, Ralph, Saidel, William M., Balombini, Katherine L. W. & Shain, Daniel H., 2018, Phylogenetic and morphological resolution of the Helobdella stagnalis species-complex (Annelida: Clitellata: Hirudinea), pp. 61-86 in Zootaxa 4403 (1) on page 70, DOI: 10.11646/zootaxa.4403.1.3, http://zenodo.org/record/121223
Helobdella echoensis Saglam & Kutschera & Saunders & Saidel & Balombini & Shain 2018, n. sp.
No full textHelobdella echoensis n. sp. (York, PA) (Figs. 2E – 7E) (Holotype: ANSP GI 19496) (LSID: urn:lsid:zoobank.org:act: F55674 B 6-1767-4 F64-ABEF-0347122944E0) —Dorsal body light to yellowish-grey, sometimes with a greenish tint. Black dots on dorsal surface. Ventral coloration and annuli numbers same as H. serendipitious n. sp. One pair of eyes close to each other on segment III (Fig. 7E). Male and female gonopores in position similar to H. serendipitious n. sp. Six pairs of testisacs intersegmentally arranged from XII/XIII to XVII/ XVIII; shape similar to H. stagnalis but smaller. Ejaculatory bulbs (atrial cornua) moderately longer, ovoidcylindrical, lying at a much lower level by the sides of the atrium, connected by slender ejaculatory ducts with sharp turn backwards into atrium in XIth segment. Ovisacs large, connected with long and curled common oviduct. Oviduct length almost equal to ovisacs (Figs. 2E, 4E). Six pairs crop caeca, 6th directed backwards and short, extending up to fourth intestinal caecum. Four pairs intestinal caecum, first two pairs slightly curved upward, third pair flat and last pair curved downward. Rectum short, “S” shaped, similar H. stagnalis (Figs. 3E, 5E). The dorsal nuchal scute of H. stagnalis from Europe has been depicted in a SEM-micrograph by Sawyer (1986, p. 538). Additional SEM identified differences in scute morphology and position between species (Fig. 8). Specifically, the s cute of Helobdella spp. ranged from rhomboidal to hexagonal, settled on the12th and extending to the 13th annulus The H. modesta scute was square-shaped, settled on the 12th annulus (on the VII-a1) and sometimes extending up to half the 13th annulus (Fig. 6B). The H. serendipitious scute was pentagonal, settled in the dorsal surface of segment VII-a2 (on annulus 12) (Fig. 6C). The Helobdella eriensis n. sp. (Farm Pond) scute was similar to H. serendipitious n. sp. but settled in the 12th and up to all of 13th annulus (Fig. 6D). The Helobdella echoensis n. sp. (York, PA) was similar to H. serendipitious n. sp. but mushroom shaped (Fig. 5E).Published as part of Saglam, Naim, Kutschera, Ulrich, Saunders, Ralph, Saidel, William M., Balombini, Katherine L. W. & Shain, Daniel H., 2018, Phylogenetic and morphological resolution of the Helobdella stagnalis species-complex (Annelida: Clitellata: Hirudinea), pp. 61-86 in Zootaxa 4403 (1) on page 71, DOI: 10.11646/zootaxa.4403.1.3, http://zenodo.org/record/121223
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
ALGAAS HBV performance in frequency tripling at 255 GHZ
No full textThis paper presents a novel method to investigate the efficiency of a tripler with a HBV diode based on Al0.7Ga0.3As/GaAs. The HBV diodes with different mesa diameters have been fabricated and their DC characteristics have been measured. These characteristics are used by a combined genetic algorithm/harmonic balance simulator to calculate the optimum impedances and output powers at the frequency of 255 GHz. A comparison of the conversion efficiencies are presented for the different structures
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
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
A novel evolutionary approach for the analysis and optimization of THz nonlinear circuits
No full textLetter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
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
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