2,123 research outputs found

    A hybrid keyboard-guitar interface using capacitive touch sensing and physical modeling

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    This paper was presented at the 9th Sound and Music Computing Conference, Copenhagen, Denmark.This paper presents a hybrid interface based on a touch- sensing keyboard which gives detailed expressive control over a physically-modeled guitar. Physical modeling al- lows realistic guitar synthesis incorporating many expres- sive dimensions commonly employed by guitarists, includ- ing pluck strength and location, plectrum type, hand damp- ing and string bending. Often, when a physical model is used in performance, most control dimensions go unused when the interface fails to provide a way to intuitively con- trol them. Techniques as foundational as strumming lack a natural analog on the MIDI keyboard, and few digital controllers provide the independent control of pitch, vol- ume and timbre that even novice guitarists achieve. Our interface combines gestural aspects of keyboard and guitar playing. Most dimensions of guitar technique are control- lable polyphonically, some of them continuously within each note. Mappings are evaluated in a user study of key- boardists and guitarists, and the results demonstrate its playa- bility by performers of both instruments

    The systematic position of Plagiochila moritziana, P. trichostoma and P. deflexa based on ITS sequence variation of nuclear ribosomal DNA, morphology, and lipophilic secondary metabolites

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    According to phylogenetic analyses of nrDNA ITS1 and ITS2 sequences (including the 5.8S unit) the Neotropical Plagiochila moritziana, P. rutilans var. rutilans, P. rutilans var. standleyi, P. trichostoma (= P. permista, syn. nov.), and P. subtrinitensis form a monophyletic lineage and are placed in P. sect. Rutilantes; all five taxa lack a ca 20 base pair sequence that is present in all the taxa of the other Plagiochila sections investigated. The Central American P. subtrinitensis is treated as a synonym of the Hawaiian endemic P. deflexa. Plagiochila moritziana is excluded from sect. Fuscoluteae and reduced to a variety of P. rutilans; P. sect. Permistae is treated as a synonym of P. sect. Rutilantes. The sporophytes of P. trichostoma and P. deflexa are described for the first time. Fresh material of P. rutilans var. moritziana exhibits a distinct odor of peppermint caused by the presence of several menthane monoterpenoids, principally pulegone. The Central American P. rutilans var. standleyi is reported from Ecuador, new to South America. Lectotypes are designated for P. rutilans var. moritziana, P. subtrinitensis, and P. trichostoma

    Susceptibility of the sod webworm \u3ci\u3ePediasia trisecta\u3c/i\u3e to biological control agents

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    Homeowners in Tennessee have observed complete destruction of their lawns by the sod webworm a few months after applying an insecticide to control sod webworms or white grubs. The reason for this increase rather than a decrease in the webworm population is not perfectly understood. We believe, however, that the natural enemies of the webworm may be reduced to such low population levels that they exert very little control on the webworm. Thus, once the natural enemies are destroyed in a lawn, it may require several months or even years for them to increase to a population level necessary to exert a satisfactory control on the webworms. In the absence of their natural enemies, which serve to control their population, the webworms, because of their high reproductive potential, increase rapidly and lawn destruction follows. Insecticides which cause an increase of webworm numbers are the chlorinated hydrocarbons such as dieldrin and chlordane. These are excellent insecticides for the control of soil insects such as white grubs which feed on grass roots but have not been satisfactory in webworm control in Tennessee. Insecticides that are recommended by the Institute of Agriculture for webworm control (Sevin and Diazinon) have not been implicated in causing webworm increases, but they probably do have an adverse effect on the natural enemy population. There is also a possibility that webworms may develop resistance to these chemieaIs. In addition, these chemicals have the disadvantage of having to be applied every 3 weeks during the summer because of their short activity period. Because of the above-mentioned disadvantages of chemicals, we are searching for new means of sod webworm control. Biological control, which involves the dissemination of large numbers of parasites, predators, and/or insect pathogens, may offer promise in sod webworm control. We have conducted preliminary studies utilizing biological control agents which are non-toxic to humans, birds, wildlife, and fish. Some of these agents are so specific as to insects attacked that certain ones can be selected that destroy the target insect pest but leave unharmed other insects and mites which are predators and parasites. Biological control agents cause no phytotoxicity at high rates as some insecticides do. Insect pathogens, which were the subject of this study, are manufactured in various formulations such as wettable powders, dusts, baits, and aqueous suspensions, and can be applied with the same equipment as insecticides. Costs for those whi

    Influence of adatom interactions on second layer nucleation

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    We develop a theory for the inclusion of adatom interactions in second layer nucleation occurring in epitaxial growth. The interactions considered are due to ring barriers between pairs of adatoms and binding energies of unstable clusters. The theory is based on a master equation, which describes the time development of microscopic states that are specified by cluster configurations on top of an island. The transition rates are derived by scaling arguments and tested against kinetic Monte-Carlo simulations. As an application we reanalyze experiments to determine the step edge barrier for Ag/Pt(111).Comment: 4 pages, 4 figure

    Exact transmission moments in one-dimensional weak localization and single-parameter scaling

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    We obtain for the first time the expressions for the mean and the variance of the transmission coefficient for an Anderson chain in the weak localization regime, using exact expansions of the complex transmission- and reflection coefficients to fourth order in the weakly disordered site energies. These results confirm the validity of single-parameter scaling theory in a domain where the higher transmission cumulants may be neglected. We compare our results with earlier results for transmission cumulants in the weak localization domain based on the phase randomization hypothesis

    Nitrogênio e potássio na produtividade da bananeira cultivar thap maeo.

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    O experimento foi realizado em Latossolo Amarelo distrófico da Amazônia Central e teve por objetivo verificar o efeito de doses nitrogênio e de potássio (K2O) sobre a produtividade e a e estado nutricional da bananeira cultivar Thap Maeo (Musa spp. - AAB). O delineamento experimental utilizado foi o de blocos casualizados em esquema fatorial (3 x 4), com os seguintes tratamentos: três doses de N (0, 267 e 534 kg ha-1 ciclo - fonte: uréia) e quatro doses de K2O (200, 800, 1600 e 2400 kg ha-1 ciclo ? fonte: cloreto de potássio), com três repetições e dois ciclos. Os resultados mostraram que o aumento das doses de N até 534 kg ha-1 reduziu a produtividade. No segundo ciclo houve interação significativa entre as doses de N e de K2O, sendo a maior produção obtida com aplicação de 1600 kg ha-1 de K2O

    Conductance and localization in disordered wires: role of evanescent states

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    This paper extends an earlier analytical scattering matrix treatment of conductance and localization in coupled two- and three Anderson chain systems for weak disorder when evanescent states are present at the Fermi level. Such states exist typically when the interchain coupling exceeds the width of propagating energy bands associated with the various transverse eigenvalues of the coupled tight-binding systems. We calculate reflection- and transmission coefficients in cases where, besides propagating states, one or two evanescent states are available at the Fermi level for elastic scattering of electrons by the disordered systems. We observe important qualitative changes in these coefficients and in the related localization lengths due to ineffectiveness of the evanescent modes for transmission and reflection in the various scattering channels. In particular, the localization lengths are generally significantly larger than the values obtained when evanescent modes are absent. Effects associated with disorder mediated coupling between propagating and evanescent modes are shown to be suppressed by quantum interference effects, in lowest order for weak disorder

    Efeito da relação magnésio e zinco sobre o teor de nutrientes nos grãos de quatro cultivares de soja.

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    O objetivo deste trabalho foi estudar o efeito da interação magnésio e zinco sobre o teor de nutrientes nos grãos de quatro cultivares de soja. Os experimentos foram conduzidos em solução nutritiva em condições de casa de vegetação do Centro de Energia Nuclear na Agricultura (CENA/USP). O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 2x4, com três repetições. Os tratamentos foram constituídos por duas doses de Mg (0,1 e 1,0 mmol L -1), aplicadas na forma de MgSO 4 e quatro doses de Zn (O, 1, e 5 mol L-1) aplicadas na forma de ZnSO4.7H2O, Foram utilizadas as cultivares IAC15-1 (semi-tardia), , IAC 17 (precoce), FT Estrela (precoce) e DM Nobre (tardia). Verificou-se que Independentemente dos tratamentos e das cultivares, os teores de K (17,73 9 kg-1), S (1,0 9 kg'1), Cu (10,8 mg kg-1) e Fe (139,4 mg kg-1) não .foram afetados pela relação magnésio e zinco, o mesmo não ocorreu com os teores deP, Ca, Mg, Ni e Zn. No caso de P, os teores ficaram aquém dos níveis considerados sdequados (0,87 9 kg-1 na DM Nobre a 1,57 kg:1 na IAC 15-1), possivelmente, qevido ao efeito de inibição na competitiva causado pelo aumento da concentração de Zn na solução. Observou-se também, que mesmo sendo o Ca' e Zn cátions bivalentes, houve nas duas concentrações de Mg, exceto na cultivar DM Nobre na concentração 0,1 mmol L-1 de Mg e Zn.aumento significativo na concentração de Ga em função das doses de Zn. Com relação aos Mg e Zn, os teores nos grãos variaram de 0,9 9 kg:1 a 1,2 9 kg'1 e 35,2 mg kg-1 a 44,5 mg kg-1, estaQdo os mesmos, diretamente rel,acionados com o aumento da concentração do nutriente na solução. Os teores de Ni diminuíram significativamente nas cultivares IAC 17 na dose 0,1 mmol L -1 de Mg e na cultivar DM Nobre na dose 1,0 mmol L'1 de Mg em função das doses de Zn, enquanto que na FT Estrela este efeito foi quadrático e positivo, ficando os teores do mesmo dentro da faixa de 1,5 mg, kg-1 a 2,8 mg kg-1, ind'ependentemente das doses de Mg eZn

    Mutation of L-2,3-diaminopropionic acid synthase genes blocks staphyloferrin B synthesis in Staphylococcus aureus

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    BACKGROUND: Staphylococcus aureus synthesizes two siderophores, staphyloferrin A and staphyloferrin B, that promote iron-restricted growth. Previous work on the biosynthesis of staphyloferrin B has focused on the role of the synthetase enzymes, encoded from within the sbnA-I operon, which build the siderophore from the precursor molecules citrate, alpha-ketoglutarate and L-2,3-diaminopropionic acid. However, no information yet exists on several other enzymes, expressed from the biosynthetic cluster, that are thought to be involved in the synthesis of the precursors (or synthetase substrates) themselves. RESULTS: Using mutants carrying insertions in sbnA and sbnB, we show that these two genes are essential for the synthesis of staphyloferrin B, and that supplementation of the growth medium with L-2,3-diaminopropionic acid can bypass the block in staphyloferrin B synthesis displayed by the mutants. Several mechanisms are proposed for how the enzymes SbnA, with similarity to cysteine synthase enzymes, and SbnB, with similarity to amino acid dehydrogenases and ornithine cyclodeaminases, function together in the synthesis of this unusual nonproteinogenic amino acid L-2,3-diaminopropionic acid. CONCLUSIONS: Mutation of either sbnA or sbnB result in abrogation of synthesis of staphyloferrin B, a siderophore that contributes to iron-restricted growth of S. aureus. The loss of staphyloferrin B synthesis is due to an inability to synthesize the unusual amino acid L-2,3-diaminopropionic acid which is an important, iron-liganding component of the siderophore structure. It is proposed that SbnA and SbnB function together as an L-Dap synthase in the S. aureus cell

    Natural enemies of rice leaf folder Cnaphalocrocis medinalis (Guenée) —a critical review

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    A chronological review of the biological control agents of rice leaf folder, Cnaphafalocrocis medinalis Guenée, including the stage of host attacked in different countries, their activity and suggestions for future. The rice leaf folder, Cnaphalocrocis medinalis Guenée, which was a pest of minor importance till the last decade, recently has assumed major importance in many rice ecosystem of Asia, the South Pacific Islands, Hawaii and Australia (Hirao, 1982). Increasingly frequent outbreaks of this pest (Table I) in recent years have been attributed to the introduction of modern rice technologies, namely: Continuous and overlapping cropping (Rajamma and Das, 1969); introduction of broad leaf dwarf, high tillering. fertilizer responsive susceptible rice varieties (Gargav and Katiyar, 1971; Dorge et al., 1972; Patel, 1975) and increased use of nitrogenous fertilizers (Michael Raj and Morachan, 1973; Chandragiri et al., 1974; Subraiah and Morachan, 1974; Dhaliwal et al., 1979; Chantaraprapha el al., 1980; Miynhara, 1981). In addition shading which causes the rice plants to grow tall with reduced silica content may make plants more susceptible (Chelliah, 1983). However, no detailed information is available as to how these factors bring about favourable conditions for larval growth and survival and or cause enhanced fecundity of the adults
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