192 research outputs found

    Treatment barriers, preferences and histories of individuals with symptoms of body dysmorphic disorder.

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    BackgroundIndividuals with mental health concerns face many barriers when accessing psychological treatment. Even when patients overcome these barriers, they often do not receive an evidence-based treatment. Although the current literature highlights these issues clearly across psychological disorders, the research is limited in relation to body dysmorphic disorder (BDD).AimThe aim of this study was to examine psychological treatment barriers, treatment delivery preferences and treatment histories of individuals with symptoms of BDD.MethodA total of 122 participants with clinically significant BDD symptoms (94% female; mean age = 34.19 years, SD = 10.86) completed the cross-sectional study.ResultsThe most frequently reported barriers to accessing psychological treatment for individuals with BDD symptoms were the cost of treatment (41%) and the belief that the symptoms did not warrant treatment (36%). Although 69% of treatment-seeking participants reported previously receiving cognitive behavioural therapy (CBT) for BDD, only 13% of participants appeared to receive best-practice CBT. The preferred modality of future psychological treatment delivery was face-to-face treatment with a therapist once a week (63%), rather than accelerated or remote treatment approaches.ConclusionsThe study suggests that there are significant barriers to accessing CBT for BDD. Reducing these barriers, as well as increasing consumer mental health literacy, is required to improve treatment access and treatment outcomes for individuals with BDD

    Quantum speedup for active learning agents

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    Can quantum mechanics help us in building intelligent robots and agents? One of the defining characteristics of intelligent behavior is the capacity to learn from experience. However, a major bottleneck for agents to learn in any real-life situation is the size and complexity of the corresponding task environment. Owing to, e.g., a large space of possible strategies, learning is typically slow. Even for a moderate task environment, it may simply take too long to rationally respond to a given situation. If the environment is impatient, allowing only a certain time for a response, an agent may then be unable to cope with the situation and to learn at all. Here we show that quantum physics can help and provide a significant speed-up for active learning as a genuine problem of artificial intelligence. We introduce a large class of quantum learning agents for which we show a quadratic boost in their active learning efficiency over their classical analogues. This result will be particularly relevant for applications involving complex task environments.Comment: Minor updates, 14 pages, 3 figure

    Growth of graph states in quantum networks

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    We propose a scheme to distribute graph states over quantum networks in the presence of noise in the channels and in the operations. The protocol can be implemented efficiently for large graph sates of arbitrary (complex) topology. We benchmark our scheme with two protocols where each connected component is prepared in a node belonging to the component and subsequently distributed via quantum repeaters to the remaining connected nodes. We show that the fidelity of the generated graphs can be written as the partition function of a classical Ising-type Hamiltonian. We give exact expressions of the fidelity of the linear cluster and results for its decay rate in random graphs with arbitrary (uncorrelated) degree distributions.Comment: 16 pages, 7 figure

    Identification of the water quality factors which prevent fingernail clams from recolonizing the Illinois River—phase III

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    TECHNICAL COMPLETION REPORT Project No. B-124-ILL Agreement No. 14-34-0001-0217The purpose of this research was to determine why fingernail clams have been unable to recolonize a 100-mile reach of the Illinois River where they were abundant prior to a die-off in the 1950's. Fingernail clams are major links in food chains leading from detritus and algae to higher level consumers valued by man, such as fish and water fowl. Three suspected toxicants and sediments from the reach where the die-off occurred were tested on intact fingernail clams (Musculium transversum) and gill preparations isolated from the clams. Concentrations of fluoride, lead and cadmium which caused a 50% reduction in the rate of beating of cilia on isolated clam gills, after 10 minutes of exposure (10-minute EC50), were 0.75, 0.02 and 0.06 mg/l , respectively. Mixtures of cadmium and fluoride were slightly more toxic to clam gills than predicted from results of bioassays with single toxicants. A fluoride concentration of 2.82 mg/l killed intact fingernail clams after eight weeks of exposure, while mortality in lesser concentrations and one higher concentration did not differ significantly from controls maintained in well water to which no fluoride had been added. Hence, the sub-lethal response exhibited by the gills is at least four times more sensitive than the lethal response. Maximum fluoride concentrations reported by the U.S. Geological Survey at two stations in the Illinois River ranged from .6 to .8 mg/l between 1979 and 1981, considerably below the concentrations which affected growth and survival of intact clams during 8-week exposures in our laboratory, but slightly above the level which affected isolated clam gills. A lead bioassay using intact clams was completed, but the results were ambiguous because concentration ranges in separate test chambers overlapped. In addition, insoluble lead precipitates accumulated in the test chambers, and the relative toxicity to clams of the soluble versus the insoluble lead was not determined. Until additional bioassays are completed, it is impossible to determine whether the maximum total lead concentrations of 0.40 mg/l which occurred in the Illinois River between 1979 and 1981 could have contributed to the failure of fingernail clams to recolonize the river. Fingernail clams exposed to sediments from lakes along the Illinois River suffered greater mortality after six weeks of exposure than clams exposed to sediment from the Mississippi River, although the differences were not statistically significant. The same sediments tested on clam gills produced statistically significant changes in ciliary beating rate and particle transport rates on the gills. Sediments from the upstream lakes cause a greater depression in the particle transport rate and ciliary beating rates than sediments from downstream lakes. In addition, sediments from the lake furthest upstream caused a drastic change from the normal metachronal beating pattern to an atypical synchronous pattern. The results with the gill assay suggest that sediments in the Illinois River contain unidentified toxic factors and that sediments in the upper river, closer to the metropolitan areas of Joliet and Chicago, are more toxic than sediments further downstream. These results should be confirmed by additional tests with intact clams, including field tests with caged organisms. Parallel chemical analyses and bioassays of extracts from the sediments should be performed to identify the toxic components.U.S. Department of the InteriorU.S. Geological SurveyOpe

    Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation

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    The so-called "polar catastrophe", a sudden electronic reconstruction taking place to compensate for the interfacial ionic polar discontinuity, is currently considered as a likely factor to explain the surprising conductivity of the interface between the insulators LaAlO3 and SrTiO3. We applied optical second harmonic generation, a technique that a priori can detect both mobile and localized interfacial electrons, to investigating the electronic polar reconstructions taking place at the interface. As the LaAlO3 film thickness is increased, we identify two abrupt electronic rearrangements: the first takes place at a thickness of 3 unit cells, in the insulating state; the second occurs at a thickness of 4-6 unit cells, i.e., just above the threshold for which the samples become conducting. Two possible physical scenarios behind these observations are proposed. The first is based on an electronic transfer into localized electronic states at the interface that acts as a precursor of the conductivity onset. In the second scenario, the signal variations are attributed to the strong ionic relaxations taking place in the LaAlO3 layer

    On the variability of HD 170699 - a possible COROT target

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    We present the analysis of the variability of HD 170699, a COROT star showing the characteristics of a non evolutionary Delta Scuti star with high rotational velocity. There is a clear period of 10.45 c/d with 5.29 mmag amplitude in the y filter. From the data, it can be seen that the star shows multi-periodicity and it is necessary to add more frequencies to adjust the observationsComment: To appear in RevMexAA(SC) in Proceedings of XII Reunion Regional Latinoamericana de la UAI held in Isla Margarita, Venezuela, October 22-26, 200

    Fluctuating-friction molecular motors

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    We show that the correlated stochastic fluctuation of the friction coefficient can give rise to long-range directional motion of a particle undergoing Brownian random walk in a constant periodic energy potential landscape. The occurrence of this motion requires the presence of two additional independent bodies interacting with the particle via friction and via the energy potential, respectively, which can move relative to each other. Such three-body system generalizes the classical Brownian ratchet mechanism, which requires only two interacting bodies. In particular, we describe a simple two-level model of fluctuating-friction molecular motor that can be solved analytically. In our previous work [M.K., L.M and D.P. 2000 J. Nonlinear Opt. Phys. Mater. vol. 9, 157] this model has been first applied to understanding the fundamental mechanism of the photoinduced reorientation of dye-doped liquid crystals. Applications of the same idea to other fields such as molecular biology and nanotechnology can however be envisioned. As an example, in this paper we work out a model of the actomyosin system based on the fluctuating-friction mechanism.Comment: to be published in J. Physics Condensed Matter (http://www.iop.org/Journals/JPhysCM

    The 2003-4 multisite photometric campaign for the Beta Cephei and eclipsing star 16 (EN) Lacertae with an Appendix on 2 Andromedae, the variable comparison star

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    A multisite photometric campaign for the Beta Cephei and eclipsing variable 16 Lacertae is reported. 749 h of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series photometry were obtained with ten telescopes during 185 nights. After removing the pulsation contribution, an attempt was made to solve the resulting eclipse light curve by means of the computer program EBOP. Although a unique solution was not obtained, the range of solutions could be constrained by comparing computed positions of the secondary component in the Hertzsprung-Russell diagram with evolutionary tracks. For three high-amplitude pulsation modes, the uvy and the Geneva UBG amplitude ratios are derived and compared with the theoretical ones for spherical-harmonic degrees l <= 4. The highest degree, l = 4, is shown to be incompatible with the observations. One mode is found to be radial, one is l = 1, while in the remaining case l = 2 or 3. The present multisite observations are combined with the archival photometry in order to investigate the long-term variation of the amplitudes and phases of the three high-amplitude pulsation modes. The radial mode shows a non-sinusoidal variation on a time-scale of 73 yr. The l = 1 mode is a triplet with unequal frequency spacing, giving rise to two beat-periods, 720.7 d and 29.1 yr. The amplitude and phase of the l = 2 or 3 mode vary on time-scales of 380.5 d and 43 yr. The light variation of 2 And, one of the comparison stars, is discussed in the Appendix.Comment: 18 pages, 19 figures, accepted for publication in MNRA

    Simple method for the characterization of intense Laguerre-Gauss vector vortex beams

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    We report on a method for the characterization of intense, structured optical fields through the analysis of the size and surface structures formed inside the annular ablation crater created on the target surface. In particular, we apply the technique to laser ablation of crystalline silicon induced by femtosecond vector vortex beams. We show that a rapid direct estimate of the beam waist parameter is obtained through a measure of the crater radii. The variation of the internal and external radii of the annular crater as a function of the laser pulse energy, at fixed number of pulses, provides another way to evaluate the beam spot size through numerical fitting of the obtained experimental data points. A reliable estimate of the spot size is of paramount importance to investigate pulsed laser-induced effects on the target material. Our experimental findings offer a facile way to characterize focused, high intensity complex optical vector beams which are more and more applied in laser-matter interaction experiments
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