7,313 research outputs found

    Sensitivity to amplitude envelope rise time in infancy and vocabulary development at 3 years: A significant relationship.

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    Here we report, for the first time, a relationship between sensitivity to amplitude envelope rise time in infants and their later vocabulary development. Recent research in auditory neuroscience has revealed that amplitude envelope rise time plays a mechanistic role in speech encoding. Accordingly, individual differences in infant discrimination of amplitude envelope rise times could be expected to relate to individual differences in language acquisition. A group of 50 infants taking part in a longitudinal study contributed rise time discrimination thresholds when aged 7 and 10 months, and their vocabulary development was measured at 3 years. Experimental measures of phonological sensitivity were also administered at 3 years. Linear mixed effect models taking rise time sensitivity as the dependent variable, and controlling for non-verbal IQ, showed significant predictive effects for vocabulary at 3 years, but not for the phonological sensitivity measures. The significant longitudinal relationship between amplitude envelope rise time discrimination and vocabulary development suggests that early rise time discrimination abilities have an impact on speech processing by infants.Australian Research Counci

    Bionomics and taxonomy of leafhopper Sophonia orientalis (Homoptera: Cicadellidae), a Pacific pest species in the Macaronesian Archipelagos

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    The leafhopper Sophonia orientalis (Matsumura) (Homoptera: Cicadellidae) is native to Asia, but it has been recently introduced to the Hawaii Archipelago, CA and French Polynesia. Although this extremely polyphagous species is considered to be a threat to all native plants of Hawaii and to many economically important cropping cultures, its taxonomy remains obscure. Most literature referred to this species as Sophonia rufofascia (Kuoh & Kuoh), but recently it has been shown that previous records of this species correspond to S. orientalis. In this study, S. orientalis is recorded from northeastern Atlantic archipelagos of Madeira and Canaries, with the Þrst collection made in 2000 representing the Þrst record of this species for Macaronesia. Diagnosis of the species together with information on the karyotype and structure of testes and ovaries is given. The number of chromosomes is 2n 16 X0 (males) and 2n 16 XX (females), and each testis and ovaryis composed of six follicles and six ovarioles, respectively. In Madeira, S. orientalis was found on 28 plant species, including native and endemic plants, but it also was associated with important crops such as vineyards. The presence of adults and nymphs during most of the year suggests that this species has several annual generations. Owing to the suitable climate and the presence of a great number of host plants, its potential for detrimental effects to Madeira ecosystems is considered to be great, and the proximity of Madeira and Canary Islands to the European land mass suggests that this pest may spread.info:eu-repo/semantics/publishedVersio

    On Graph-Theoretic Identifications of Adinkras, Supersymmetry Representations and Superfields

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    In this paper we discuss off-shell representations of N-extended supersymmetry in one dimension, ie, N-extended supersymmetric quantum mechanics, and following earlier work on the subject codify them in terms of certain graphs, called Adinkras. This framework provides a method of generating all Adinkras with the same topology, and so also all the corresponding irreducible supersymmetric multiplets. We develop some graph theoretic techniques to understand these diagrams in terms of a relatively small amount of information, namely, at what heights various vertices of the graph should be "hung". We then show how Adinkras that are the graphs of N-dimensional cubes can be obtained as the Adinkra for superfields satisfying constraints that involve superderivatives. This dramatically widens the range of supermultiplets that can be described using the superspace formalism and organizes them. Other topologies for Adinkras are possible, and we show that it is reasonable that these are also the result of constraining superfields using superderivatives. The family of Adinkras with an N-cubical topology, and so also the sequence of corresponding irreducible supersymmetric multiplets, are arranged in a cyclical sequence called the main sequence. We produce the N=1 and N=2 main sequences in detail, and indicate some aspects of the situation for higher N.Comment: LaTeX, 58 pages, 52 illustrations in color; minor typos correcte

    On the Construction and the Structure of Off-Shell Supermultiplet Quotients

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    Recent efforts to classify representations of supersymmetry with no central charge have focused on supermultiplets that are aptly depicted by Adinkras, wherein every supersymmetry generator transforms each component field into precisely one other component field or its derivative. Herein, we study gauge-quotients of direct sums of Adinkras by a supersymmetric image of another Adinkra and thus solve a puzzle from Ref.[2]: The so-defined supermultiplets do not produce Adinkras but more general types of supermultiplets, each depicted as a connected network of Adinkras. Iterating this gauge-quotient construction then yields an indefinite sequence of ever larger supermultiplets, reminiscent of Weyl's construction that is known to produce all finite-dimensional unitary representations in Lie algebras.Comment: 20 pages, revised to clarify the problem addressed and solve

    Multiple Quantum NMR Dynamics in Dipolar Ordered Spin Systems

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    We investigate analytically and numerically the Multiple Quantum (MQ) NMR dynamics in systems of nuclear spins 1/2 coupled by the dipole-dipole interactions in the case of the dipolar ordered initial state. We suggest two different methods of MQ NMR. One of them is based on the measurement of the dipolar temperature in the quasi-equilibrium state which establishes after the time of order T2 after the MQ NMR experiment. The other method uses an additional resonance 45^0 -pulse after the preparation period of the standard MQ NMR experiment in solids. Many-spin clusters and correlations are created faster in such experiments than in the usual MQ NMR experiments and can be used for the investigation of many-spin dynamics of nuclear spins in solids.Comment: 11 pages, 3 figures. accepted for publication in Physical Review

    Twist Deformation of Rotationally Invariant Quantum Mechanics

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    Non-commutative Quantum Mechanics in 3D is investigated in the framework of the abelian Drinfeld twist which deforms a given Hopf algebra while preserving its Hopf algebra structure. Composite operators (of coordinates and momenta) entering the Hamiltonian have to be reinterpreted as primitive elements of a dynamical Lie algebra which could be either finite (for the harmonic oscillator) or infinite (in the general case). The deformed brackets of the deformed angular momenta close the so(3) algebra. On the other hand, undeformed rotationally invariant operators can become, under deformation, anomalous (the anomaly vanishes when the deformation parameter goes to zero). The deformed operators, Taylor-expanded in the deformation parameter, can be selected to minimize the anomaly. We present the deformations (and their anomalies) of undeformed rotationally-invariant operators corresponding to the harmonic oscillator (quadratic potential), the anharmonic oscillator (quartic potential) and the Coulomb potential.Comment: 20 page

    The problem of nutrition and the state of health of the population of the Ural region

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    The article shows that the structure of the overall incidence of the Ural region residents rank first disease of the respiratory system, the second - the blood system, the third - diseases of digestive organs, the fourth is a violation of the psyche. Important factors of their development are violations of quality foods that provoke the development of various diseasesВ статье показано, что в структуре общей заболеваемости жителей Уральского региона первое место занимают заболевания органов дыхания, второе – системы крови, третье – болезни органов пищеварения, четвертое – нарушения психики. Важными факторами их развития являются нарушения качества пищевых продуктов, провоцирующих развитие различных болезне

    Efficient production of polar molecular Bose-Einstein condensates via an all-optical R-type atom-molecule adiabatic passage

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    We propose a scheme of "RR-type" photoassociative adiabatic passage (PAP) to create polar molecular condensates from two different species of ultracold atoms. Due to the presence of a quasi-coherent population trapping state in the scheme, it is possible to associate atoms into molecules with a \textit{low-power} photoassociation (PA) laser. One remarkable advantage of our scheme is that a tunable atom-molecule coupling strength can be achieved by using a time-dependent PA field, which exhibits larger flexibility than using a tunable magnetic field. In addition, our results show that the PA intensity required in the "RR-type" PAP could be greatly reduced compared to that in a conventional "Λ\Lambda -type" one.Comment: 17 pages, 5 figures, to appear in New Journal of Physic
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