2,177 research outputs found
Globalization of Distinguished Supercuspidal Representations of GL(n)
No full textAn irreducible supercuspidal representation of = GL(n, ), where is a nonarchimedean local field of characteristic zero, is said to be “distinguished” by a subgroup of and a quasicharacter of if Hom(, ) ≠ 0. There is a suitable global analogue of this notion for an irreducible, automorphic, cuspidal representation associated to GL(n). Under certain general hypotheses, it is shown in this paper that every distinguished, irreducible, supercuspidal representation may be realized as a local component of a distinguished, irreducible automorphic, cuspidal representation. Applications to the theory of distinguished supercuspidal representations are provided
Restriction of Representations of GL (n + 1, ℂ) to GL (n, ℂ) and Action of the Lie Overalgebra
No full textConsider a restriction of an irreducible finite dimensional holomorphic representation of GL(n+1,C) to the subgroup GL(n,C). We write explicitly formulas for generators of the Lie algebra gl(n+1) in the direct sum of representations of GL(n,C). Nontrivial generators act as differential-difference operators, the differential part has order n − 1, the difference part acts on the space of parameters (highest weights) of representations. We also formulate a conjecture about unitary principal series of GL(n,C).© The Author(s) 201
The Balanced Voronoi Formulas for
No full textAbstract
In this article, we show how the Voronoi summation formula of [13] can be rewritten to incorporate hyper-Kloosterman sums of various dimensions on both sides. This generalizes a formula for with ordinary Kloosterman sums on both sides that was used in [1] to prove nonvanishing of GL(4) -functions by GL(2)-twists, and later by the second-named author in [16].</jats:p
Bethe Vectors for Composite Models with gl(2|1) and gl(1|2) Supersymmetry
No full textSupersymmetric composite generalized quantum integrable models solvable by the algebraic Bethe ansatz are studied. Using a coproduct in the bialgebra of monodromy matrix elements and their action on Bethe vectors, formulas for Bethe vectors in the composite models with supersymmetry based on the super-Yangians Y[gl(2|1)] and Y[gl(1|2)] are derived.The author wants to express his gratitude to N.A. Slavnov for the proposal to investigate this
topic and discussions. He thanks also to S. Pakuliak for discussions and to A.P. Isaev and
C. Burd´ık for their support. The work of the author has been supported by the Grant Agency ˇ
of the Czech Technical University in Prague, grant No. SGS15/215/OHK4/3T/14, and by the
Grant of the Plenipotentiary of the Czech Republic at JINR, Dubna
Combinatorial results on (1,2,1,2)-avoiding -orbit closures on
No full text35 pages, 18 figuresInternational audienceUsing recent results of the second author which explicitly identify the "-avoiding" -orbit closures on the flag manifold as certain Richardson varieties, we give combinatorial criteria for determining smoothness, lci-ness, and Gorensteinness of such orbit closures. (In the case of smoothness, this gives a new proof of a theorem of W.M. McGovern.) Going a step further, we also describe a straightforward way to compute the singular locus, the non-lci locus, and the non-Gorenstein locus of any such orbit closure. We then describe a manifestly positive combinatorial formula for the Kazhdan-Lusztig-Vogan polynomial in the case where corresponds to the trivial local system on a -avoiding orbit closure and corresponds to the trivial local system on any orbit contained in . This combines the aforementioned result of the second author, results of A. Knutson, the first author, and A. Yong, and a formula of Lascoux and Sch\"{u}tzenberger which computes the ordinary (type ) Kazhdan-Lusztig polynomial whenever is cograssmannian
Gephyrocapsa huxleyi (Emiliania huxleyi) as a model system for coccolithophore biology
No full textCoccolithophores are the most abundant calcifying organisms in modern oceans and are important primary producers in many marine ecosystems. Their ability to generate a cellular covering of calcium carbonate plates (coccoliths) plays a major role in marine biogeochemistry and the global carbon cycle. Coccolithophores also play an important role in sulfur cycling through the production of the climate-active gas dimethyl sulfide. The primary model organism for coccolithophore research is Emiliania huxleyi, now named Gephyrocapsa huxleyi. G. huxleyi has a cosmopolitan distribution, occupying coastal and oceanic environments across the globe, and is the most abundant coccolithophore in modern oceans. Research in G. huxleyi has identified many aspects of coccolithophore biology, from cell biology to ecological interactions. In this perspective, we summarize the key advances made using G. huxleyi and examine the emerging tools for research in this model organism. We discuss the key steps that need to be taken by the research community to advance G. huxleyi as a model organism and the suitability of other species as models for specific aspects of coccolithophore biology
The E10 Wheeler-DeWitt operator at low levels
No full textWe consider the Wheeler-DeWitt operator associated with the bosonic part of the Hamiltonian of D=11 supergravity in a formulation with only the spatial components of the three-form and six-form fields, and compare it with the E10 Casimir operator at low levels, to show that these two operators precisely match modulo spatial gradients up to and including gl(10) level two. The uniqueness of the E10 Casimir operator eliminates all ordering ambiguities in the quantum Hamiltonian, at least up to the level considered. Beyond level three the two operators are expected to start to differ from each other, as they do so for the classical expressions. We then consider truncations of the E10 Wheeler-DeWitt operator for various finite-dimensional subgroups of E10 in order to exhibit the automorphic properties of the associated wave functions and to show that physically sensible wave functions generically vanish at the cosmological singularity, thus providing new and more sophisticated examples of DeWitt's proposed mechanism for singularity resolution in quantum gravity. Our construction provides novel perspectives on several unresolved conceptual issues with the Wheeler-DeWitt equation, such as the question of observables in quantum gravity, or the issue of emergent space and time in a purely algebraic framework. We also highlight remaining open questions of the E10 framework
Lachnomyrmex scrobiculatus Wheeler 1910
No full textLachnomyrmex scrobiculatus Wheeler, 1910 Figures 16, 19 Lachnomyrmex scrobiculatus Wheeler, 1910: 263, fig. 3. Syntypes, GUATEMALA: Alta Vera Paz: Trece Aguas, Cacao, 24.iii. 1906, E.A. Schwarz & H.S. Barber cols, no. 21059 (1 worker) [MCZC] (examined by images); same data; no. 13199 (1 worker) [USNM] (examined); same locality; 29.iii. 1906, E.A. Schwarz & H.S. Barber col., no code data (1 worker) [AMNH] (examined); same locality, 4.iv. 1906, E.A. Schwarz & H.S. Barber cols, no. 13199 (1 worker, here designated lectotype in order to improve nomenclatural stability) [USNM] (examined); same locality, 25.iv. 1906, E.A. Schwarz & H.S. Barber cols, no. 13199 (1 gyne) [USNM] (examined); same locality, 26.iv. 1906, E.A. Schwarz & H.S. Barber cols, no. 13199 (1 worker) [USNM] (examined); same data (1 worker) not located; Gotwald 1969: 106 (mouthparts). Worker diagnosis. Body densely covered by continuous irregular rugae; metanotal groove obsolete; teeth of propodeal lobes widen basally; petiolar node subtriangular; dorsum of postpetiole convex and strongly rugose; first tergite of gaster entirely covered by long flexuous hairs. Lectotype measurements. HL 0.65; HW 0.61; ML 0.17; SL 0.38; EL 0.12; WL 0.75; PSL 0.19; PL 0.33; PPL 0.16; GL 0.80; TL 2.86; CI 95; SI 61; OI 19. Worker measurements (n= 18). HL 0.60–0.66; HW 0.58–0.65; ML 0.17–0.22; SL 0.36–0.40; EL 0.12– 0.15; WL 0.69–0.76; PSL 0.14–0.19; PL 0.27–0.33; PPL 0.14–0.18; GL 0.74–0.87; TL 2.80–2.99; CI 95–100; SI 58–64; OI 19–24. Gyne measurements (n= 5). HL 0.66–0.68; HW 0.65–0.66; ML 0.22–0.24; SL 0.38–0.42; EL 0.16–0.19; WL 0.87–0.88; PSL 0.17–0.20; PL 0.31–0.33; PPL 0.17–0.20; GL 0.96–1.10; TL 3.23–3.36; CI 96–99; SI 57–65; OI 24–29. Worker description. Color dark brown to black, with appendages lighter. Body densely covered by vermiculate and somewhat thick rugae, transverse on anterior portion of pronotum, grading to longitudinal on rest of promesonotum, metapleura and lateral faces of propodeum; rugae somewhat longer and longitudinal on head dorsum and relatively sparser on metapleura and lateral faces of propodeum; mandibles with short striae restricted to the most basal portion; in dorsal view, metanotal area with long transversal rugae extending laterally towards metapleura; petiole and postpetiole irregularly rugose. Abundant pilosity, except by dorsal surface of propodeum; petiolar node, dorsum of postpetiole and first gastral tergite covered by long flexuous hairs; pilosity on first tergite of gaster concentrated at the most dorsal portion. Head usually slightly longer than broad, with vertexal margin minimally convex; frontal lobes relatively well developed and laterally rounded; eyes with about six facets on maximum diameter. Promesonotum moderately convex in profile; metanotal groove obsolete; propodeal spines straight; teeth of propodeal lobes well developed and considerably swollen basally, reaching propodeal spines half-length. Petiolar node elevated and subtriangular, in lateral view; postpetiole strongly convex and with a discrete anteroventral projection. Gyne. Similar to worker; body pilosity considerably denser; eyes with about 12 facets at greatest diameter; wings with the basic pattern of venation for the genus; petiolar peduncle somewhat elongate; petiolar node faintly lower than in the conspecific worker. Etymology. The species name refers to the presence of the deep antennal scrobes, observed by Wheeler (1910) in the original description of Lachnomyrmex. Comments. This species is uniquely characterized by the pattern of sculpturation, absence of an impressed metanotal groove, and the presence of the small subpostpetiolar process. Gynes are somewhat more generalized morphologically (see comments under L. pilosus). In the description of the Lachnomyrmex sting apparatus (Kugler 1978), the author identifies the examined species as closely related to L. scrobiculatus. However, we have not examined this material, and thus it was not possible to confirm Kugler´s identification. Lachnomyrmex scrobiculatus is a relatively common species occurring from southern Mexico (Chiapas) throughout continental Central America to southern Panama. Workers and gynes occur in samples of sifted leaf litter from the forest floor in different elevations (100–1100m). Michael Kaspari collected a specimen at a barley bait in the La Selva successional plots, Costa Rica (Longino 2007). Additional material examined. BELIZE: El Cayo: Caves Branch, viii. 1972, S. Peck & J. Peck col. (5 workers) [MZSP]; COSTA RICA: Alajuela: Casa Eladio, Río Penas Blancas, 2.iii. 2004, J.T. Longino col., no. INBIOCRI000005395 (1 worker) [INBC]; Río San Lorencito, 1990, P. Hammond col. (6 workers) [BMNH]; same data (1 worker) [MZSP]; Guanacaste: Estr. Pitilla, 9km S Sta. Cecília, i. 1991, I Curso Microhym., nos. INBIOCRI000305058/ INBIOCRI000384713 (2 workers) [INBC]; same locality, 3–18.x. 1991, P. Ríos col., no. INBIOCRI000377966 (1 worker) [INBC]; Pitilla Field Station, 2.v. 1995, R. Anderson col., no. 17722 (7 workers and 3 gynes) [WPMC]; same data (2 workers and 1 gyne) [MZSP]; same locality, 14.ii. 1996, R. Anderson col., nos. 17739 / 17741 (3 workers) [WPMC]; Limón: P.N. Tortuguero, Cerro Tortuguero, ii. 1993, R. Delgado col., nos. INBIOCRI001289301/INBIOCRI001289339 (2 workers and 1 gyne) [INBC]; same data, INBIOCRI001289337 (1 worker) [MZSP]; Puntarenas: Península Osa, Aenn. Fund. Neotrop., 23.vi. 1997, R. Anderson col., nos. 18686 / 18687 (1 worker and 1 gyne) [WPMC]; Cerro Helado, 15km NE Rincón, 24.vi. 1997, R. Anderson col., no. 18689 (1 gyne) [WPMC]; PANAMA: Canal Zone: Barro Colorado Island, 1976, S. Levings col. (1 worker) [MIZA].Published as part of Feitosa, Rodrigo M. & Brandão, Carlos Roberto F., 2008, A taxonomic revision of the Neotropical myrmicine ant genus Lachnomyrmex Wheeler (Hymenoptera: Formicidae), pp. 1-49 in Zootaxa 1890 on pages 40-41, DOI: 10.5281/zenodo.18430
Compartmentalized Calcium Signaling in Cilia Regulates Intraflagellar Transport
No full textIntraflagellar transport (IFT) underpins many of the important cellular roles of cilia and flagella in signaling and motility [1,2,3,4]. The microtubule motors kinesin-2 and cytoplasmic dynein 1b drive IFT particles (protein complexes carrying ciliary component proteins) along the axoneme to facilitate the assembly and maintenance of cilia. IFT is regulated primarily by cargo loading onto the IFT particles, although evidence suggests that IFT particles also exhibit differential rates of movement [5,6,7]. Here we demonstrate that intraflagellar Ca2+ elevations act to directly regulate the movement of IFT particles. IFT-driven movement of adherent flagella membrane glycoproteins in the model alga Chlamydomonas enables flagella-mediated gliding motility [8,9,10]. We find that surface contact promotes the localized accumulation of IFT particles in Chlamydomonas flagella. Highly compartmentalized intraflagellar Ca2+ elevations initiate retrograde transport of paused IFT particles to modulate their accumulation. Gliding motility induces mechanosensitive intraflagellar Ca2+ elevations in trailing (dragging) flagella only, acting to specifically clear the accumulated microtubule motors from individual flagella and prevent a futile tug-of-war. Our results demonstrate that compartmentalized intraciliary Ca2+ signaling can regulate the movement of IFT particles and is therefore likely to play a central role in directing the movement and distribution of many ciliary proteins
The Acquisition of Grey Literature in Developing Countries
No full textGL constitutes an important information collection in research and university libraries. Despite its eminent value and importance to both scholars and scientists, the procurement of these collection poses serious problems to information professionals. These problems are particularly serious in he third world where bibliographic control activities have yet to catch up with the developed world. This project will therefore attempt to analyse the practice and problems associated with the procurement of this collection in the developing world. The aims and objectives are: to examine the procurement of GL in developing countries; to critically examine the various acquisition methods employed in the procurement of the collection; to analyse the problems experienced in their procurement; to propose solutions to the stated problems. The author hopes to base his study on the following research methodologies. Literature Review: Will be made to scan all documentary information related to the above subject. Much information is anticipated from journal articles, conference papers and to a limited extent, books. Interview: The author hopes to interview a number of people on the subject in Kenya. Among them will be information professionals in university and research libraries; and researchers and scholars who by nature of their programmes use unpublished literature. For information professionals outside Kenya, the author hopes to write to a selected few to seek their views on specific issues. Author's Experience: The author also hopes to draw on his considerable experience as an acquisition librarian in special and research libraries in the third world. The conclusion will be based on the research findings. The research will no doubt highlight the problems existing in the area of GL acquisition and their possible solutions.Includes: Conference preprint, Pratt student commentaryXAInternationa
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