19,568 research outputs found

    Greater priming for previously distracting information in young than older adults when suppression is ruled out

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    The use of previously distracting information on memory tests with indirect instructions is usually age-equivalent, while young adults typically show greater explicit memory for such information. This could reflect qualitatively distinct initial processing (encoding) of distracting information by younger and older adults, but could also be caused by greater suppression of such information by younger adults on tasks with indirect instructions. In Experiment 1, young and older adults read stories containing distracting words, which they ignored, before studying a list of words containing previously distracting items for a free recall task. Half the participants were informed of the presence of previously distracting items in the study list prior to recall (direct instruction), and half were not (indirect instruction). Recall of previously distracting words was age-equivalent in the indirect condition, but young adults recalled more distracting words in the direct condition. In Experiment 2, participants performed the continuous identification with recognition task, which captures a measure of perceptual priming and recognition on each trial, and is immune to suppression. Priming and recognition of previously distracting words was greater in younger than older adults, suggesting that the young engage in more successful suppression of previously distracting information on tasks in which its relevance is not overtly signaled

    The Planck Surveyor mission: astrophysical prospects

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    Although the Planck Surveyor mission is optimized to map the cosmic microwave background anisotropies, it will also provide extremely valuable information on astrophysical phenomena. We review our present understanding of Galactic and extragalactic foregrounds relevant to the mission and discuss on one side, Planck's impact on the study of their properties and, on the other side, to what extent foreground contamination may affect Planck's ability to accurately determine cosmological parameters. Planck's multifrequency surveys will be unique in their coverage of large areas of the sky (actually, of the full sky); this will extend by two or more orders of magnitude the flux density interval over which mm/sub-mm counts of extragalactic sources can be determined by instruments already available (like SCUBA) or planned for the next decade (like the LSA-MMA or the space mission FIRST), which go much deeper but over very limited areas. Planck will thus provide essential complementary information on the epoch-dependent luminosity functions. Bright radio sources will be studied over a poorly explored frequency range where spectral signatures, essential to understand the physical processes that are going on, show up. The Sunyaev-Zeldovich effect, with its extremely rich information content, will be observed in the direction of a large number of rich clusters of Galaxies. Thanks again to its all sky coverage, Planck will provide unique information on the structure and on the emission properties of the interstellar medium in the Galaxy. At the same time, the foregrounds are unlikely to substantially limit Planck's ability to measure the cosmological signals. Even measurements of polarization of the primordial Cosmic Microwave background fluctuations appear to be feasible.Comment: 20 pages, Latex (use aipproc2.sty, aipproc2.cls, epsfig.sty), 10 PostScript figures; invited review talk, Proc. of the Conference: "3 K Cosmology", Roma, Italy, 5-10 October 1998, AIP Conference Proc, in press Note: Figures 6 and 7 have been replaced by new and correct version

    Infrared Quasi Fixed Points and Mass Predictions in the MSSM II: Large tan(beta) Scenario

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    We consider the infrared quasi fixed point solutions of the renormalization group equations for the Yukawa couplings and soft supersymmetry breaking parameters in the MSSM in the \underline{large tanβ\tan\beta} regime. The existence of IR quasi fixed points together with the values of gauge couplings, third generation quarks, lepton and Z-boson masses allows one to predict masses of the Higgs bosons and SUSY particles as functions of the only free parameter, m1/2m_{1/2}, or the gluino mass. The lightest Higgs boson mass for MSUSY1M_{SUSY} \approx 1 TeV is found to be mh=128.20.47.1±5m_h=128.2-0.4-7.1 \pm 5 GeV for μ>0\mu>0 and mh=120.60.13.8±5m_h=120.6-0.1-3.8 \pm 5 GeV for μ<0\mu<0.Comment: 15 pages, LateX file with 4 eps figures, corrected numbers, new column in table, last versio

    The Energy-Momentum Tensor in Fulling-Rindler Vacuum

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    The energy density in Fulling-Rindler vacuum, which is known to be negative "everywhere" is shown to be positive and singular on the horizons in such a fashion as to guarantee the positivity of the total energy. The mechanism of compensation is displayed in detail.Comment: 9 pages, ULB-TH-15/9

    From spinning to non-spinning cosmic string spacetimes

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    We analyse the properties of a fluid generating a spinning cosmic string spacetime with flat limiting cases corresponding to a constant angular momentum in the infinite past and static configuration in the infinite future. The spontaneous loss of angular momentum of a spinning cosmic string due to particle emission is discussed. The rate of particle production between the spinning and non-spinning cosmic string spacetimes is calculated.Comment: 11 pages, 1 figure, LaTeX To appear in Class. Quantum Gra

    Share of nations in 37 international public health journals : an equity and diversity perspective towards health research capacity building.

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    Background: This paper contributes to further exploration of inequity in access to health research capacity development by examining the representation of different nations in international public health journals. It also aims to examine the degree of diversity that exists in these journals.Methods: This study is a descriptive survey. It was done with objective sampling on 37 ISI health journals on October of 2008.The number and nationality of people in different editorial positions of the journals was identified. The second analy­sis involved recalculating the numbers obtained for each nation to the population size of nations per million inhabitants. In order to better compare countries in terms of presence in editorial team of the journals, a ‘public health editor equity gap ratio' (PHEEGR) was developed.Results: Low income countries have occupied none of the leadership positions of chief editor or associate /assistant chief editors and middle income countries at maximum shared less than 5 percent. The PHEEGR gap in access to the different editorial positions between highest to the lowest representation of countries was 16/1 for chief editors, 12/1 for associate editors , 335/1 for editorial boards and 202/1 for associate editorial boards. However, after normalizing the data to the country's population, the gap increased significantly.Conclusion: There is an imbalance and possibly even inequity in the composition of editorial boards and offices of interna­tional health journals that should be paid significant attention. This can contribute to fill the equity gap exists between health in developing and developed countries

    Developing an applied model for making decisions towards the end of life about care for someone with dementia

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    BACKGROUND: Many people with dementia reach the end-of-life without an advance care plan. Many are not ready to have conversations about end-of-life, and decision-making is left to their families and professionals when they no longer have capacity. Carers may benefit from further support with decision-making. To develop this support, it is important to understand the decision-making process. AIM: Explore with family carers and people living with dementia the decision-making process and factors that influence decision-making in dementia end of life care, to produce a model of decision-making in the context of dementia end-of-life care. METHODS: Semi-structured interviews with 21 family carers and 11 people with dementia in England (2018–2019) from memory clinics, general practice and carer organisations. Interviews were analysed using thematic analysis and findings were mapped onto the Interprofessional Shared Decision Making model, refined to produce a modified model of decision-making in dementia. RESULTS: Participants described five key decisions towards the end-of-life as examples of decision making. We used these experiences to produce a modified model of decision-making in dementia end-of-life-care. The model considers the contextual factors that influence the decision-making process, including: personal preferences; advance care planning and Lasting Power of Attorney; capacity and health and wellbeing of the person with dementia; support from others and clarity of roles. The decision-making process consists of seven inter-linked stages: 1) identifying the decision maker or team; 2) sharing and exchanging information; 3) clarifying values and preferences; 4) managing and considering emotions; 5) considering the feasibility of options; 6) balancing preferred choice and the actual choice; and 7) implementation and reflecting on outcomes. CONCLUSIONS: The modified model breaks down the decision-making process and attempts to simplify the process while capturing the subtle nuances of decision making. It provides a framework for conversations and supporting decisions by carers

    The origin of very wide binary systems

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    The majority of stars in the Galactic field and halo are part of binary or multiple systems. A significant fraction of these systems have orbital separations in excess of thousands of astronomical units, and systems wider than a parsec have been identified in the Galactic halo. These binary systems cannot have formed through the 'normal' star-formation process, nor by capture processes in the Galactic field. We propose that these wide systems were formed during the dissolution phase of young star clusters. We test this hypothesis using N-body simulations of evolving star clusters and find wide binary fractions of 1-30%, depending on initial conditions. Moreover, given that most stars form as part of a binary system, our theory predicts that a large fraction of the known wide 'binaries' are, in fact, multiple systems.Comment: 4 pages, 1 figure, to appear in the proceedings of IAU Symposium 266, eds. R. de Grijs & J.R.D. Lepin

    Further Discoveries of 12CO in Low Surface Brightness Galaxies

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    Using the IRAM 30m telescope we have obtained seven new, deep CO J(1-0) and J(2-1) observations of low surface brightness (LSB) galaxies. Five of the galaxies have no CO detected to extremely low limits (0.1-0.4 K km/s at J(1-0)), while two of the galaxies, UGC 01922 and UGC 12289, have clear detections in both line transitions. When these observations are combined with all previous CO observations taken of LSB systems, we compile a total of 34 observations, in which only 3 galaxies have had detections of their molecular gas. Comparing the LSB galaxies with and without CO detections to a sample of high surface brightness (HSB) galaxies with CO observations indicates that it is primarily the low density of baryonic matter within LSB galaxies which is causing their low CO fluxes. Finally, we note that one of the massive LSB galaxies studied in this project, UGC 06968 (a Malin-1 `cousin'), has upper limits placed on both M_H2 and M_H2/M_HI which are 10-20 times lower than the lowest values found for any galaxy (LSB or HSB) with similar global properties. This may be due to an extremely low temperature and metallicity within UGC 06968, or simply due to the CO distribution within the galaxy being too diffuse to be detected by the IRAM beam.Comment: 18 pages, 8 figures, 4 tables. Accepted by Ap

    Derivative spectroscopy and the continuous relaxation spectrum

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    Derivative spectroscopy is conventionally understood to be a collection of techniques for extracting fine structure from spectroscopic data by means of numerical differentiation. In this paper we extend the conventional interpretation of derivative spectroscopy with a view to recovering the continuous relaxation spectrum of a viscoelastic material from oscillatory shear data. To achieve this, the term “spectroscopic data” is allowed to include spectral data which have been severely broadened by the action of a strong low-pass filter. Consequently, a higher order of differentiation than is usually encountered in conventional derivative spectroscopy is required. However, by establishing a link between derivative spectroscopy and wavelet decomposition, high-order differentiation of oscillatory shear data can be achieved using specially constructed wavelet smoothing. This method of recovery is justified when the reciprocal of the Fourier transform of the filter function (convolution kernel) is an entire function, and is particularly powerful when the associated Maclaurin series converges rapidly. All derivatives are expressed algebraically in terms of scaling functions and wavelets of different scales, and the recovered relaxation spectrum is expressible in analytic form. An important feature of the method is that it facilitates local recovery of the spectrum, and is therefore appropriate for real scenarios where the oscillatory shear data is only available for a finite range of frequencies. We validate the method using synthetic data, but also demonstrate its use on real experimental data
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