Nonlinear stabilitty for steady vortex pairs

In this article, we prove nonlinear orbital stability for steadily translating vortex pairs, a family of nonlinear waves that are exact solutions of the incompressible, two-dimensional Euler equations. We use an adaptation of Kelvin's variational principle, maximizing kinetic energy penalised by a multiple of momentum among mirror-symmetric isovortical rearrangements. This formulation has the advantage that the functional to be maximized and the constraint set are both invariant under the flow of the time-dependent Euler equations, and this observation is used strongly in the analysis. Previous work on existence yields a wide class of examples to which our result applies.Comment: 25 page

Effect Of Post Type And Restorative Techniques On The Strain And Fracture Resistance Of Flared Incisor Roots

Restoring flared endodontically treated teeth continues to be a challenge for clinicians. This study evaluated the effect of post types and restorative techniques on the strain, fracture resistance, and fracture mode of incisors with weakened roots. One hundred five endodontically treated bovine incisors roots (15 mm) were divided into 7 groups (n=15). The two control groups were (C) intact roots restored with Cpc (cast posts and core) or Gfp (glass fiber posts). The five experimental groups were (F) flared roots restored with GfpAp (Gfp associated with accessory glass fiber posts), GfpRc (anatomic Gfp, relined with composite resin), and GfpRcAp (anatomized Gfp with resin and accessory glass fiber posts). All teeth were restored with metal crowns. Mechanical fatigue was performed with 3x10 5/50 N. Specimens were loaded at 45°, and the strain values (μS) were obtained on root buccal and proximal surfaces. Following that, the fracture resistance (N) was measured. One-way ANOVA and Tukey's HSD tests (α=0.05) were applied, and failure mode was checked. No significant difference in strain values among the groups was found. Cpc presented lower fracture resistance and more catastrophic failures in flared roots. Gfp associated with composite resin or accessory glass fiber posts seems to be an effective method to improve the biomechanical behavior of flared roots.223230237Coelho, C.S., Biffi, J.C., Silva, G.R., Abrahão, A., Campos, R.E., Soares, C.J., Finite element analysis of weakened roots restored with composite resin and posts (2009) Dent Mater J, 28, pp. 671-678Teixeira, C.S., Silva-Sousa, Y.T., Sousa-Neto, M.D., Bond strength of fiber posts to weakened roots after resin restoration with different light-curing times (2009) J Endod, 35, pp. 1034-1039Zogheib, L.V., Pereira, J.R., do Valle, A.L., de Oliveira, J.A., Pegoraro, L.F., Fracture resistance of weakened roots restored with composite resin and glass fiber post (2008) Braz Dent J, 19, pp. 329-333Marchi, G.M., Mitsui, F.H., Cavalcanti, A.N., Effect of remaining dentine structure and thermal-mechanical aging on the fracture resistance of bovine roots with different post and core systems (2008) Int Endod J, 41, pp. 969-976da Silveira, T.C., Santos, F.M.C., Silva-Sousa, Y.T., de Sousa-Neto, M.D., Interfacial evaluation of experimentally weakened roots restored with adhesive materials and fibre posts: An SEM analysis (2008) J Dent, 36, pp. 672-682Moosavi, H., Maleknejad, F., Kimyai, S., Fracture resistance of endodontically-treated teeth restored using three root- reinforcement methods (2008) J Contemp Dent Pract, 9, pp. 30-37Bonfante, G., Kaizer, O.B., Pegoraro, L.F., do Valle, A.L., Fracture strength of teeth with flared root canals restored with glass fibre posts (2007) Int Dent J, 57, pp. 153-160Santos, A.F., Meira, J.B., Tanaka, C.B., Xavier, T.A., Ballester, R.Y., Lima, R.G., Can fiber posts increase root stresses and reduce fracture? (2010) J Dent Res, 89, pp. 587-591da Silva, N.R., Raposo, L.H., Versluis, A., Fernandes-Neto, A.J., Soares, C.J., The effect of post, core, crown type, and ferrule presence on the biomechanical behavior of endodontically treated bovine anterior teeth (2010) J Prosthet Dent, 104, pp. 306-317Silva, N.R., Castro, C.G., Santos-Filho, P.C., Silva, G.R., Campos, R.E., Soares, P.V., Influence of different post design and composition on stress distribution in maxillary central incisor: Finite element analysis (2009) Indian J Dent Res, 20, pp. 153-158Santos-Filho, P.C., Castro, C.G., Silva, G.R., Campos, R.E., Soares, C.J., Effects of post system and length on the strain and fracture resistance of root filled bovine teeth (2008) Int Endod J, 41, pp. 493-501Soares, C.J., Castro, C.G., Santos, F.P.C., Soares, P.V., Magalhaes, D., Martins, L.R., Two-dimensional FEA of dowels of different compositions and external surface configurations (2009) J Prosthodont, 18, pp. 36-42Macedo, V.C., de Faria, S.A.L., Martins, L.R., Effect of cement type, relining procedure, and length of cementation on pull-out bond strength of fiber posts (2010) J Endod, 36, pp. 1543-1546Leitune, V.C., Collares, F.M., Werner, S.S.M., Influence of chlorhexidine application at longitudinal push-out bond strength of fiber posts (2010) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 110, pp. 77-81Novais, V.R., Quagliatto, P.S., Bona, A.D., Correr-Sobrinho, L., Soares, C.J., Flexural modulus, flexural strength, and stiffness of fiber-reinforced posts (2009) Indian J Dent Res, 20, pp. 277-281Marchi, G.M., Paulillo, L.A., Pimenta, L.A., de Lima, F.A., Effect of different filling materials in combination with intraradicular posts on the resistance to fracture of weakened roots (2003) J Oral Rehabil, 30, pp. 623-629Soares, C.J., Pizi, E.C., Fonseca, R.B., Martins, L.R., Influence of root embedment material and periodontal ligament simulation on fracture resistance tests (2005) Braz Oral Res, 19, pp. 11-16Huysmans, M.C., Peters, M.C., van der Varst, P.G., Plasschaert, A.J., Failure behaviour of fatigue-tested post and cores (1993) Int Endod J, 26, pp. 294-300Soares, P.V., Santos-Filho, P.C., Gomide, H.A., Araujo, C.A., Martins, L.R., Soares, C.J., Influence of restorative technique on the biomechanical behavior of endodontically treated maxillary premolars. Part II: Strain measurement and stress distribution (2008) J Prosthet Dent, 99, pp. 114-122Kishen, A., Kumar, G.V., Chen, N.N., Stress-strain response in human dentine: Rethinking fracture predilection in post-core restored teeth (2004) Dent Traumatol, 20, pp. 90-10

Number-phase entropic uncertainty relations and Wigner functions for solvable quantum systems with discrete spectra

In this letter, the number-phase entropic uncertainty relation and the number-phase Wigner function of generalized coherent states associated to a few solvable quantum systems with nondegenerate spectra are studied. We also investigate time evolution of number-phase entropic uncertainty and Wigner function of the considered physical systems with the help of temporally stable Gazeau-Klauder coherent states.Comment: 10 pages, 9 figures; To appear in Phys Lett A 200

Description Of The Hemipenial Morphology Of Tupinambis Quadrilineatus Manzani And Abe, 1997 (squamata, Teiidae) And New Records From Piauí, Brazil

Few data are available on the morphology of the hemipenis of teiid lizards, especially those of the recentlydefined genus Tupinambis, a widely-distributed group of large-bodied lizards. This study provides an illustrated description of the hemipenis of Tupinambis quadrilineatus, which is similar to that of other representatives of the Tupinambinae subfamily. New records of the species from the state of Piauí, in northeastern Brazil, are also presented. © Marcélia Basto da Silva et al.3616172Avila-Pires, T.C.S., (1995) Lizards of Brazilian Amazonia (Reptilia: Squamata), p. 706. , Zoologische VerhandelingenBarreto, L., Arzabe, C., Lima, Y.C.C., Herpetofauna da região de Balsas (2007) Cerrado Norte do Brasil, pp. 221-229. , In: Barreto L (Ed), USEB, PelotasBöhme, W., Zur Genitalmorphologie der Sauria: Funktionelle und stammesgeschichtliche Aspekte (1988) Bonner Zoologische Monographien, 27, pp. 1-176Colli, G.R., Péres Jr., A.K., Cunha, H.J., A new species of Tupinambis (Squamata: Teiidae) from Central Brazil, with an analysis of morphological and genetic variation in the genus (1998) Herpetologica, 54 (4), pp. 477-492Cope, E.D., On the hemipenes of the Sauria (1896) Proceedings of the Academy of Natural Sciences of Philadelphia, 48, pp. 461-467Costa, H.C., São Pedro, V.A., Péres, A.K., Feio, N.R., Reptilia, Squamata, Teiidae, Tupinambis longilineus: Distribution extension (2008) Check List, 4, pp. 267-268Dal Vechio, F., Recoder, R., Rodrigues, M.T., Zaher, H., The herpetofauna of the Estação Ecológica de Uruçuí-Una, state of Piauí, Brazil (2013) Papéis Avulsos de Zoologia, 53 (16), pp. 225-243. , doi: 10.1590/S0031-10492013001600001Dowling, H.G., Duellman, W.E., (1978) Systematic Herpetology: A Synopsis of Families and Higher Categories, p. 118. , HISS Publications, New YorkFerreira, L.V., Pereira, J.L.G., Avila-Pires, T.C.S., Chaves, P.P., Cunha, D.A., Furtado, C.S., Primeira ocorrência de Tupinambis quadrilineatus Manzani, Abe, 1997 (Squamata: Teiidae) no bioma Amazônia (2009) Boletim do Museu Paraense Emílio Goeldi Ciências Naturais, 4 (3), pp. 355-361Fitzgerald, L.A., Cook, J.A., Aquino, A.J., Molecular phylogenetics and conservation of Tupinambis (Sauria: Teiidae) (1999) Copeia, pp. 894-905. , doi: 10.2307/1447965Guimarães, T.C.S., Figueiredo, G.B., Salmito, W.E., Geographic distribution: Tupinambis quadrilineatus (2007) Herpetological Review, 38 (3), pp. 353-354Harvey, M.B., Ugueto, G.N., Gutberlet, R.L., Review of Teiid Morphology with a Revised Taxonomy and Phylogeny of the Teiidae (Lepidosauria: Squamata) (2012) Zootaxa, pp. 1-156. , http://zoobank.org/References/457C2AD0-E5CF-4A41-B6CB-11722700BC5FLangstroth, R.P., Adiciones probables y confirmadas para la saurofauna boliviana (2005) Kempffiana, 1 (1), pp. 101-128Levington, A.E., McDiarmid, R., Moody, S., Nickerson, M., Rosado, J., Sokol, O., Voris, H., Museum acronyms (1980) Second edition, Herpetological Review, 11, pp. 93-102Lima, A.C., Pimenta, F.E., Reptilia, Squamata, Teiidae, Tupinambis longilineus: Distribution extension (2008) Check List, 4, pp. 240-243Manzani, P.R., Abe, A., A new species of Tupinambis Daudin, 1802 (Squamata: Teiidae) from Brazil (1997) Boletim do Museu Nacional, Nova Série, Zoologia, 382, pp. 1-10Manzani, P.R., Abe, A., Sobre dois novos métodos de preparação de hemipênis de serpentes (1988) Memórias do Instituto Butantan, 50 (1), pp. 15-20Manzani, P.R., Abe, A.S., A new species of Tupinambis Daudin, 1803 from southeastern Brazil (Squamata, Teiidae) (2002) Arquivos do Museu Nacional, Rio de Janeiro, 60, pp. 295-302Mesquita, D.O., Colli, G.R., França, F.G.R., Vitt, L.J., Ecology of a Cerrado lizard assemblage in the Jalapão region of Brazil (2006) Copeia 2006, (3), pp. 460-471. , doi: 10.1643/0045-8511(2006)2006[460:EOACLA]2.0.CO;2Moreira, L.A., Fenolio, D.B., Silva, H.L.R., Silva Jr., N.J., A preliminary list of the Herpetofauna from termite mounds of the cerrado in the Upper Tocantins river valley (2009) Papéis Avulsos de Zoologia, 49 (15), pp. 183-189. , http://www.scielo.br/scielo.php?pid=S0031-10492009001500001&script=sci_arttextMyers, C.H., Williams, E.E., McDiarmid, R.W., A new anoline lizard (Phenacosaurus) from the highland of Cerro de la Neblina, Southern Venezuela (1993) American Museum Novitates 3070, pp. 1-15Pesantes, O.S., A method for preparing the hemipenis of preserved snakes (1994) Journal of Herpetology, 28, pp. 93-95. , doi: 10.2307/1564686Recoder, R., Nogueira, C., Composição e diversidade de répteis na região sul do Parque Nacional Grande Sertão Veredas, Brasil Central (2007) Biota Neotropica, 7 (3), pp. 267-278. , doi: 10.1590/S1676-06032007000300029Recoder, R.S., Junior, M.T., Camacho, A., Nunes, P.M.S., Mott, T., Valdujo, P.H., Ghellere, J.M., Rodrigues, M.T., Répteis da Estação Ecológica Serra Geral do Tocantins, Brasil Central (2011) Biota Neotropica, 11 (1), pp. 263-282. , doi: 10.1590/S1676-06032011000100026Savage, J.M., On terminology for the description of the hemipenis of squamate reptiles (1997) Herpetological Journal, 7, pp. 23-25. , doi: 10.1590/S1984-46702011000400005Silva Jr., N.J., Silva, H.L.R., Rodrigues, M.T., Valle, N.C.U., Costa, M.C., Castro, S.P., Linder, E.T., Sites Jr., J.W., A fauna de vertebrados do vale do alto rio Tocantins em áreas de usinas hidrelétricas (2005) Estudos, 32, pp. 57-101Silveira, A.L., Reptilia, Squamata, Teiidae, Tupinambis quadrilineatus: Distribution extension and geographic distribution map (2009) Check List, 5 (3), pp. 442-445Taylor, J.F., Genus Tupinambis, Tegus (2003) Reptilia, 27, pp. 43-49Vitt, L.J., Cadwell, J.P., Colli, G.R., Garda, A.A., Mesquita, D.O., França, F.G.R., Shepard, D.B., Silva, V.N., Uma atualização do guia fotográfico dos répteis e anfíbios da região do Jalapão no Cerrado brasileiro (2005) Special Publications in Herpetology, San Noble Oklahoma Museum of Nature History, 2, pp. 1-24Werneck, F.P., Colli, G.R., The lizard assemblage from seasonally dry tropical forest enclaves in the Cerrado biome, Brazil, and its association with the pleistocenic arc (2006) Journal of Biogeography, 33, pp. 1983-1992. , doi: 10.1111/j.1365-2699.2006.01553.xZaher, H., Prudente, A.L.C., Hemipenis of Siphlophis (Serpentes, Xenodontinae) and Techniques of Hemipenial Preparation in Snakes: A Response to Dowling (2003) Herpetological Review, 34, pp. 302-30

Deep Inelastic Scattering and Gauge/String Duality

We study deep inelastic scattering in gauge theories which have dual string descriptions. As a function of $gN$ we find a transition. For small $gN$, the dominant operators in the OPE are the usual ones, of approximate twist two, corresponding to scattering from weakly interacting partons. For large $gN$, double-trace operators dominate, corresponding to scattering from entire hadrons (either the original `valence' hadron or part of a hadron cloud.) At large $gN$ we calculate the structure functions. As a function of Bjorken $x$ there are three regimes: $x$ of order one, where the scattering produces only supergravity states; $x$ small, where excited strings are produced; and, $x$ exponentially small, where the excited strings are comparable in size to the AdS space. The last regime requires in principle a full string calculation in curved spacetime, but the effect of string growth can be simply obtained from the world-sheet renormalization group.Comment: 52 pages, 10 figure

Generation of two-mode nonclassical states and a quantum phase gate operation in trapped ion cavity QED

We propose a scheme to generate nonclassical states of a quantum system, which is composed of the one-dimensional trapped ion motion and a single cavity field mode. We show that two-mode SU(2) Schr\"odinger-cat states, entangled coherent states, two-mode squeezed vacuum states and their superposition can be generated. If the vibration mode and the cavity mode are used to represent separately a qubit, a quantum phase gate can be implemented.Comment: to appear in PR

Soils, Geoenvironments and Ecosystem Services of a Protected Area in Western Brazilian Amazonia

Abstract The Serra do Divisor National Park (SDNP) in the Westernmost Brazilian Amazonia possesses unique Mountain landscapes of sub-andean nature, with high geo-biodiversity and pristine environments, with a potential high contribution in ecosystems services. We studied and mapped the basic geo-environmental units of the main sector of the Park, evaluating soil carbon stocks as a key ecosystem service provided by the Protected Area. For the identification, characterization and mapping of the geoenvironmental units, we integrated pedological, geomorphological and vegetation data obtained by local soil survey and field campaigns, as well as secondary data. Eight geoenvironmental units were identified and mapped, distributed in three main compartments: the Serra do Divisor (SD) the upper Moa River and the medium Moa River. This region presents similar environments to the sub-Andean region, notably the Ceja Forest at the top surface of the SD. Soils at the SD have high organic carbon accumulation, with close association with the nutrient-poor, quartz-rich rocks, and shows organic matter illuviation indicating active podzolization. The SDNP encompasses important ecosystems and services linked with high geo-biodiversity, and high soil carbon stocks, representing a new frontier for scientific research in the only area of transitional sub-andean forested landscape in Brazil