1,540 research outputs found
Direct and long-lasting effects elicited by repeated drug administration on 50-kHz ultrasonic vocalizations are regulated differently: Implications for the study of the affective properties of drugs of abuse
Several studies suggest that 50-kHz ultrasonic vocalizations (USVs) may indicate a positive affective state in rats, and these vocalizations are increasingly being used to investigate the properties of psychoactive drugs. Previous studies, however, have focused on dopaminergic psychostimulants and morphine, whereas little is known about how other drugs modulate 50-kHz USVs. To further elucidate the neuropharmacology of 50-kHz USVs, the present study characterized the direct and long-lasting effects of different drugs of abuse, by measuring the number of 50-kHz USVs and their 'trill' subtype emitted by adult male rats. Rats received repeated administrations of amphetamine (2 mg/kg, i.p.), 3,4-methylenedioxymethamphetamine (MDMA, 7.5 mg/kg, i.p.), morphine (7.5 mg/kg, s.c.), or nicotine (0.4 mg/kg, s.c.), on either consecutive or alternate days (five administrations in total) in a novel environment. Seven days later, rats were re-exposed to the drug-paired environment, subjected to USVs recording, and then challenged with the same drug. Finally, 7 d after the challenge, rats were repeatedly exposed to the drug-paired environment and vocalizations were measured. Amphetamine was the only drug to stimulate 50-kHz USVs and 'trill' subtype emission during administration and challenge. Conversely, all rats emitted 50-kHz USVs when re-exposed to the test cage, and this effect was most marked in morphine-treated rats, and less evident in nicotine-treated rats. This study demonstrates that the direct and long-lasting effects of drugs on 50-kHz USVs are regulated differently, providing a better understanding of the usefulness of these vocalizations in the study of psychoactive drugs
Stable non-BPS D-branes of type I
We review the boundary state description of the non-BPS D-branes in the type
I string theory and show that the only stable configurations are the D-particle
and the D-instanton. We also compute the gauge and gravitational interactions
of the non-BPS D-particles and compare them with the interactions of the dual
non-BPS particles of the heterotic string finding complete agreement. In this
way we provide further dynamical evidence of the heterotic/type I duality.Comment: 8 pages, 1 figure.eps, JHEP.cls, talk given by A. Lerda at the TMR
Conference "Quantum aspects of gauge theories, supersymmetry and
unification", Paris, September 199
Modular anomaly equation, heat kernel and S-duality in N=2 theories
We investigate epsilon-deformed N=2 superconformal gauge theories in four
dimensions, focusing on the N=2* and Nf=4 SU(2) cases. We show how the modular
anomaly equation obeyed by the deformed prepotential can be efficiently used to
derive its non-perturbative expression starting from the perturbative one. We
also show that the modular anomaly equation implies that S-duality is
implemented by means of an exact Fourier transform even for arbitrary values of
the deformation parameters, and then we argue that it is possible,
perturbatively in the deformation, to choose appropriate variables such that it
reduces to a Legendre transform.Comment: 30 pages, LeTeX2e. V2: references added, appendix B expanded, a few
typos correcte
Anyonic Realization of the Quantum Affine Lie Superalgebra U_q(A(M,N)^{(1)})
We give a realization of the quantum affine Lie superalgebras U_q(A(M,N))^(1)
in terms of anyons defined on a one or two-dimensional lattice, the deformation
parameter q being related to the statistical parameter of the anyons by q
= exp(i\pi\nu). The construction uses anyons contructed from usual fermionic
oscillators and deformed bosonic oscillators. As a byproduct, realization
deformed in any sector of the quantum superalgebras U_q(A(M,N)) is obtained.Comment: 14p LaTeX Document (should be run twice
Flight flexibility in strategic traffic planning: visualisation and mitigation use case
The concept of strategic traffic planning that takes into account changing airspace configurations, their capacity, and allows the quantification of flight flexibility is presented in this paper: the visualization of the results and an example of possible use. The concept is implemented through two deterministic optimization models. Here, we focus on the output of the models, which identifies the departure times, trajectories, flight flexibility and the list of saturated sector-hours throughout the day, based on the configurations used during the day. In order to make the output understandable to various stakeholders, we use a visualization tool and a set of performance indicators. The information on the saturated sectors, and their impact on flexibility (criticality index) is taken as an input in the example of mitigation action application by Air Navigation Service Providers, aimed at improving the situation. A mitigation strategy of increasing capacity of saturated airspace is implemented, and results show that the improvements in flexibility can be achieved
Anyonic Realization of the Quantum Affine Lie Algebra U_q(A_N)
We give a realization of quantum affine Lie algebra in
terms of anyons defined on a two-dimensional lattice, the deformation parameter
being related to the statistical parameter of the anyons by . In the limit of the deformation parameter going to one we recover
the Feingold-Frenkel fermionic construction of undeformed affine Lie algebra.Comment: 13p LaTeX Document (should be run twice
Non-perturbative aspects of gauge/gravity duality
Recently we provided a microscopic derivation of the exact supergravity profile for the twisted scalar field emitted by systems of fractional D3-branes at a Z2 orbifold singularity. In this contribution we focus on a set-up supporting an N = 2 SYM theory with SU(2) gauge group and Nf=4. We take into account the tower of D-instanton corrections to the source terms for the twisted scalar and find that its profile can be expressed in terms of the chiral ring elements of the gauge theory. We show how the twisted scalar, which at the perturbative level represents the gravity counterpart of the gauge coupling, at the non-perturbative level is related to the effective gauge coupling in an interestingly modified way
No habitat preference in mixed meadows and rocky bottoms for Mediterranean Labridae and Sparidae fish species
Fish species composition, abundance, diversity and niche breadth of Mediterranean littoral communities have been assessed for two types of habitat: rocky bottoms and mixed meadows of Posidonia oceanica (L.) Delile, 1813 and rocks. Labridae and Sparidae species have been considered to test differences in abundances between both habitats by means of underwater visual census. Data obtained suggests that these fish assemblages are very similar, and there are no significant differences in the niche breadth of both habitats. Differences in physical structure of the habitats are not enough to produce differences in the fish assemblages observed. A high fishing pressure in the study area may be removing the predator fish species, and consequently determining the species composition and abundance for rocky bottoms.Se ha estudiado la composición específica, la abundancia, la diversidad y la amplitud de nicho de dos comunidades ícticas mediterráneas mediante censos visuales en dos tipos de hábitat: fondos rocosos y fondos mixtos de Posidonia oceanica (L.) Delile, 1813 y roca. Se han observado especies de lábridos y espáridos y no se han encontrado diferencias significativas en las variables analizadas de estas comunidades en ambos hábitats. Las diferencias en la estructura física de los dos tipos de hábitat no son suficientes para justificar la aparición de variaciones significativas en las comunidades ícticas estudiadas. Un factor condicionante puede ser la elevada tasa de presión pesquera, que elimina las especies depredadoras y determinaría la composición específica y la abundancia de peces en los fondos rocosos.Instituto Español de Oceanografí
XRSpotlight: Example-based Programming of XR Interactions using a Rule-based Approach
Research on enabling novice AR/VR developers has emphasized the need to lower the technical barriers to entry. This is often achieved by providing new authoring tools that provide simpler means to implement XR interactions through abstraction. However, novices are then bound by the ceiling of each tool and may not form the correct mental model of how interactions are implemented. We present XRSpotlight, a system that supports novices by curating a list of the XR interactions defined in a Unity scene and presenting them as rules in natural language. Our approach is based on a model abstraction that unifies existing XR toolkit implementations. Using our model, XRSpotlight can find incomplete specifications of interactions, suggest similar interactions, and copy-paste interactions from examples using different toolkits. We assess the validity of our model with professional VR developers and demonstrate that XRSpotlight helps novices understand how XR interactions are implemented in examples and apply this knowledge in their projects
Stable non-BPS D-branes in Type I string theory
We use the boundary state formalism to study, from the closed string point of
view, superpositions of branes and anti-branes which are relevant in some
non-perturbative string dualities. Treating the tachyon instability of these
systems as proposed by A. Sen, we show how to incorporate the effects of the
tachyon condensation directly in the boundary state. In this way we manage to
show explicitly that the D1 -- anti-D1 pair of Type I is a stable non-BPS
D-particle, and compute its mass. We also generalize this construction to
describe other non-BPS D-branes of Type I. By requiring the absence of tachyons
in the open string spectrum, we find which configurations are stable and
compute their tensions. Our classification is in complete agreement with the
results recently obtained using the K-theory of space-time.Comment: 31 pages, plain LaTeX, final version to be published in Nucl. Phys.
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