130,405 research outputs found
Conformal variations and quantum fluctuations in discrete gravity
No full textAfter an overview of variational principles for discrete gravity, and on the basis of the approach to conformal transformations in a simplicial PL setting proposed by Luo and Glickenstein, we present at a heuristic level an improved scheme for addressing the gravitational (Euclidean) path integral and geometrodynamics
Dacus (Psilodacus) merzi White
No full textDacus (Psilodacus) merzi White Dacus (Psilodacus) merzi White, 2006: 132 Material. KENYA: 2 males, 1 female, Mt. Elgon Lodge, 1 – 6.xi. 1983, A. Freidberg (TAU) Remarks. White (2006) described this species from a single male which had an almost complete (c. 90 %) covering of microtrichia in cell c. These males are similar but the female has a considerably reduced covering of microtrichia in cell c (around 75 %) and will erroneously run to D. herensis Munro, 1984 using the key provided by White (2006) (corrected in revised key). The known males, including the holotype, all have a large inverted-V mark on the face, just below the antennal insertions. In the female this is reduced to a pair of very small dark marks.Published as part of White, Ian M. & Goodger, Kim F. M., 2009, African Dacus (Diptera: Tephritidae); New Species and Data, with Particular Reference to the Tel Aviv University Collection, pp. 1-49 in Zootaxa 2127 on page 42, DOI: 10.5281/zenodo.27492
Normal matrix models and orthogonal polynomials for a class of potentials with discrete rotational symmetries
Get PDFIn this thesis we are going to study normal random matrix models which generalize naturally the polynomially perturbed Ginibre ensamble, focusing in particular on their eigenvalue distribution and on the asymptotics of the associated orthogonal polynomials. \\
The main result we are going to present are the following:
\begin{itemize}
\item we describe the explicit derivation of the equilibrium measure for a class of potentials with discrete rotational symmetries, namely of the form
\item We obtain the strong asymptotics for the orthogonal polynomials associated to the weight
and we will show how the density of their zeroes is related to the eigenvalue distribution of the corresponding matrix model;
\item We show how the conformal maps used to describe the support of the equilibrium measure for polynomial perturbation of the potential lead to a natural generalization of the concept of polynomial curves introduced in by Elbau.
\end{itemize
Parallelomma merzi OZEROV 2011
No full textParallelomma merzi OZEROV, 2011a D i s t r i b u t i o n: Thailand, Vietnam (OZEROV & KRIVOSHEINA 2011a). C o m m e n t: MERZ (2006: 224) cited one male of Parallelomma sp. from MHNG as "...first genus of this family recorded from Thailand ". This specimen was later described by OZEROV & KRIVOSHEINA (2011a) as a new species.Published as part of V, Marco, 2021, Annotated supplements to catalogues of the family Scathophagidae (Diptera) in the world, with new taxonomic data, notes on some species and new list of species, pp. 1267-1306 in Linzer biologische Beiträge 52 (2) on page 1274, DOI: 10.5281/zenodo.503898
Rhagoletis merzi Korneyev & Smith & Hulbert & Frey & Korneyev 2022, sp. n.
No full textRhagoletis merzi sp. n. (figs 1, c; 7–8) urn:lsid:zoobank.org:act: ADCCE1F4-7DB8-4EB6-9B5C-339A7F8F6ED9 Rhagoletis batava: Merz, 1994: 108 (misidentification); Rhagoletis flavigenualis: V. Korneyev in: Merz, 2006: 8 (misidentification); Rhagoletis sp. near flavigenualis: Korneyev et al., 2018 a: 466. T y p e m a t e r i a l. Holotype Ơ: Switzerland: Visperterminen, VS, 1400 m, 26.07.1990 (Merz) (MNHG ENTO 00012822) (MHNG). Paratypes: Switzerland: 1 ♀, Visperterminen, h = 1400 m, 17.07.1995 (Merz) (MNHG ENTO 00012824); Visperterminen, VS, 1400 m: 1 Ơ, 18.07.1993 (Merz) (MNHG ENTO 0001825); 1 Ơ, idem, 1520 m, 20.07.1993 Wald (Merz) (MNHG ENTO 0001828); 1 Ơ, idem, 17.07.1995 (Merz) (MNHG ENTO 0001823); 1 Ơ, Visperterminen, Kreuz, h = 1500 m, 21.07.2004 (Merz) (MNHG ENTO 0001827) (MHNG); Visperterminen, [Kreuz,] h = 1300–1900 m [swept from Juniperus sabina], 21.07.2004, 1 Ơ, 1 ♀ (S. & V. Korneyev) (SIZK). N o n - t y p e s p e c i m e n s. Switzerland: Visperterminen, h = 1300–1900 m, reared from Juniperus sabina fleshy cones, 3 puparia [used for DNA extraction completely], 17.10.2016 (J. Smith). D i a g n o s i s. Rhagoletis merzi is similar to all other species having the wing pattern with four dark bands, apical band joined to subapical band and separated by a crescent hyaline area from the costal vein anteroapically. It is most similar to, and in fact to our knowledge morphologically indistinguishable from, the Nearctic R. juniperina. Both species have the occiput widely black or brown on the upper 1/3, wing bands uniformly brown to blackish, mid and hind femora black, male lateral surstylus with the posterior lobe relatively short, 0.6–0.75 times as long as surstylus basal of prensisetae (fig. 8, b), and female spermathecae large, 0.09 mm in diameter, with short neck (fig. 2, f). We recognize R. merzi as a distinct species from R. juniperina based on the significant genetic distance between their COI sequences (K2P = 0.071). Rhagoletis merzi is also very similar to the Central Asian R. mongolica and R. scutellata (both known only from their holotypes, not examined for potential genitalic differences) in general appearance, including the wing pattern and having the occiput widely black on the upper 1/3. Rhagoletis mongolica is also associated with J. sabina, like R. merzi, whereas the host for R. scutellata is unknown. Rhagoletis merzi differs from R. mongolica by having black rather than yellow femora and from R. scutellata by abdominal tergites 2–4 having whitish or yellowish posterior margins and the basicostal cell brownish (in R. scutellata, basicostal cell entirely hyaline and abdominal tergites uniformly black or brown). This species readily differs from the West Palearctic R. flavigenualis and R. zernyi by having the widely black or brown median occipital sclerite, black mid and hind femora, and uniformly brown wing bands (in R. flavigenualis and R. zernyi median occipital sclerite and all femora uniformly yellow (very rarely only hind femur partly brown), and the wing bands at least partly yellow with brownish borders; R. zernyi differs also by having the discal and subapical bands widely fused). The genetic distance between R. merzi and R. flavigenualis is also significant (K2P = 0.063 –0.066). Rhagoletis merzi is similar to the Palearctic species R. bagheera and R. batava, and the Nearctic R. bushi in having the wing bands uniformly brown to blackish, and mid and hind femora black, differing from them by having the male lateral surstylus with the posterior lobe conspicuously shorter, 0.6–0.75 times as long as the surstylus basal of the prensisetae (fig. 8, b) vs. 1.3–1.4 times as long as the surstylus basal of the prensisetae in R. bagheera (fig. 3, c) and R. batava (fig. 6, a), and female spermathecae larger, 0.09 mm in diameter, with a short neck (fig. 2, f) vs. 0.02–0.03 mm in diameter, with the neck longer than the spermatheca itself in R. bagheera and R. batava. Rhagoletis merzi also has a different host plant, Juniperus sabina L., vs. Hippophae rhamnoides (Elaeagnaceae) for R. batava and Rhamnus palasii (Rhamnaceae) for R. bagheera. The genetic distance between R. merzi and R. batava is K2P = 0.064 –0.068, and between R. merzi and R. bushi K2P = 0.078 –0.079. D e s c r i p t i o n. Head. Orange-yellow, ocellar triangle, ventral part of median occipital sclerite and often occiput lateral of it black or brown. Antennal arista pubescent. Setae black except postocellar, posterior genal, and some occipital setae white. Paravertical seta short, about as long as black acuminate postocular setae. — Thorax. Scutum black, yellowish setulose, with microtrichia pattern with two pairs of partly fused matte grayish vittae separated by subshining darker areas.Postpronotal lobe and notopleural stripe creamy white to yellow; scutellum pale yellow, black on anterior margin dorsally and laterally. All thoracic setae black; basal scutellar seta inserted into black area. Halter yellow to creamy white. — Legs. Fore coxa yellow, mid and hind coxae black or brown; fore and mid trochanters yellow; hind trochanter brown or black; fore femur yellow anteroventrally, black posterodorsally; mid and hind femora black except apices yellow; hind femur somewhat thickened in male, with 2–3 longer subapical anterodorsal and 2–3 longer subapical anteroventral setae; tibiae and tarsi yellow (fig. 7). — Wing (fig. 1, c). 2.3 times as long as wide, with pattern consisting of basicostal cell with brownish tinge and four dark brown bands; subbasal band from humeral crossvein over basal half of costal cell through cells br, bm and cua (= anal cell auctt.) slightly into cell cup, discal band from pterostigma over crossvein r-m to posterior margin between veins M 4 (= CuA 1) and CuA + CuP (= CuA 1 +A 1), subapical band from middle of cell r 1 over crossvein dm-m (= dm-cu) and apical band from middle of cell r 1 into apex of cell m 4; discal band separated from both subbasal and subapical bands (figs. 1, c; 7, a) or at most narrowly fused with subapical band at posterior margin (fig. 7, c); subapical and subapical bands fused in cells r 1 and r 2+3; apical band separated from costa between apex of cell r 1 and vein M 1; no intercalary band; vein R 4+5 dorsally with 1 seta at node. — Abdomen. All segments mostly black, posterior margin of tergites 2–4 in male, and 2–5 in female narrowly creamy yellow (figs. 9, b, d). Oviscape shining black, as long as tergite 5; setae and setulae black. — G e n i t a l i a. M a l e. Epandrium black. Proctiger as long as epandrium (fig. 10, b). Surstylus dark yellow, lateral susrtylus with posterior lobe short, 0.6–0.75 times as long as surstylus basal of prensisetae (fig. 9, b). Phallus with moderately large glans (fig. 8, c) having membranous, narrow, finger-like apicodorsal process, large prepuce with smooth walls, and acrophallus with pair of semitubular filaments, very similar to that of R. bagheera (Richter & Kandybina, 1997: fig. 5), R. flavigenualis (fig. 6, c) and R. juniperina (Bush, 1966: fig. 125); preglans short and simple, without eversible caecum. Female. Eversible membrane with two pairs of taeniae 0.5 × as long as membrane itself, ventral side of membrane with scales of different size, medial ones larger than lateral ones and moderately pointed (fig. 9, g). Two globular spermathecae, 0.09 mm in diameter, with long scale-like papillae on surface (fig. 9, f). Aculeus brown, 5.5 × as long as wide, with acute apex (figs. 9, d–e). Measurements. Body length Ơ = 3.8–4.2 mm; wing length Ơ = 4.1–4.2 mm. Body length ♀ = 4.0– 4.4 mm; wing length Ơ = 3.0, wing length ♀ = 3.6 mm, costal cell length = 0.9; aculeus length = 0.85 mm; aculeus length /costal cell length = 0.9. Host plant. Juniperus sabina L. The pupae for DNA analysis were reared from the same plants and in the same locality as the type specimens were swept. D i s t r i b u t i o n. Switzerland. E t y m o l o g y. This species is named in honor of the eminent Swiss dipterist Dr.Bernhard Merz, who collected most of the type specimens, in recognition of his contributions to the study of fruit flies. Remarks. Kandybina (1977) reported specimens of “ R. mongolica ” with entirely black femora and partly black tibiae reared from Juniperus sabina in Kyrgyzstan, which need re-examination to determine whether they are conspecific with R. merzi.Published as part of Korneyev, S. V., Smith, J. J., Hulbert, D. L., Frey, J. E. & Korneyev, V. A., 2022, A New Species Of Rhagoletis (Diptera, Tephritidae) From Switzerland, With Discussion Of Its Relationships Within The Genus, pp. 1-20 in Zoodiversity 56 (1) on pages 12-15, DOI: 10.15407/zoo2022.01.001, http://zenodo.org/record/645614
Orthogonal Polynomials for a Class of Measures with Discrete Rotational Symmetries in the Complex Plane
Get PDFWe obtain the strong asymptotics of polynomials pn(λ), λ ∈ C, orthogonal with respect to measures in the complex plane of the forme−N(|λ|2s−tλs−tλs)dA(λ),where s is a positive integer, t is a complex parameter and dA stands for the area measure in the plane. Such problem has its origin from normal matrix models. We study the asymptotic behaviour of pn(λ) in the limit n, N → ∞ in such a way that n/N → T constant. Such asymptotic behaviour has two distinguished regimes according to the topology of the limiting support of the eigenvalues distribution of the normal matrix model. If 0 < |t| 2 < T /s, the eigenvalue distribution support is a simply connected compact set of the complex plane, while for |t| 2 > T /s the eigenvalue distribution supportconsists of s connected components. Correspondingly the support of the limiting zero distribution of the orthogonal polynomials consists of a closed contour contained in each connected component. Our asymptotic analysis is obtained by reducing the planar orthogonality conditions of the polynomialsto an equivalent contour integral orthogonality conditions. The strong asymptotics for the orthogonal polynomials is obtained from the corresponding Riemann–Hilbert problem by the Deift– Zhou nonlinear steepest descent method
MeSH term explosion and author rank improve expert recommendations
Get PDFInformation 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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"
Get PDFBoth 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.
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