316 research outputs found

    Personality Traits and Eating Habits in a Large Sample of Estonians

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    Indicators of the scientific impact of nations revisited

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    An improved Indicator of a Nation’s Scientific Impact (INSI), which, in addition to citation rates, takes into account how many research areas in which each nation has exceeded the entrance thresholds of the Essential Science Indicators (ESI, Clarivate Analytics), was proposed. This indicator provided a more realistic estimate of nations’ scientific impact, which was better predicted from the societal factors that are related to the quality of scientific output. The strongest predictor of countries’ scientific impact was good governance, while economic wealth and research and development expenditure played a relatively minor role in predicting research impact. We conclude that good governance is needed to create an environment, which can facilitate the translation of money invested into the production of high-impact scientific output

    A New Approach for Assessment of Mental Architecture: Repeated Tagging

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    A new approach to the study of a relatively neglected property of mental architecture—whether and when the already-processed elements are separated from the to-be-processed elements—is proposed. The process of numerical proportion discrimination between two sets of elements defined either by color or by orientation can be described as sampling with or without replacement (characterized by binomial or hypergeometric probability distributions respectively) depending on the possibility to tag an element once or repeatedly. All empirical psychometric functions were approximated by a theoretical model showing that the ability to keep track of the already tagged elements is not an inflexible part of the mental architecture but rather an individually variable strategy which also depends on conspicuity of perceptual attributes. Strong evidence is provided that in a considerable number of trials, observers tagged the same element repeatedly which can only be done serially at two separate time moments

    Intraindividual Variability and Temporal Stability of Mid-Sleep on Free and Workdays

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    People differ in their sleep timings that are often referred to as a chronotype and can be operationalized as mid-sleep (midpoint between sleep onset and wake-up). The aims of the present studies were to examine intraindividual variability and longer-term temporal stability of mid-sleep on free and workdays, while also considering the effect of age. We used data from a 2-week experience sampling study of British university students (Study 1) and from a panel study of Estonian adults who filled in the Munich Chronotype Questionnaire twice up to 5 years apart (Study 2). Results of Study 1 showed that roughly 50% of the variance in daily mid-sleep scores across the 14-day period was attributed to intraindividual variability as indicated by the intraclass correlation coefficient. However, when the effect of free versus workdays was considered, the intraindividual variability in daily mid-sleep across 2 weeks was 0.71 the size of the interindividual variability. In Study 2, mid-sleep on free and workdays showed good levels of temporal stability—the retest correlations of mid-sleep on free and workdays were 0.66 and 0.58 when measured twice over a period of 0-1 to 5 years. The retest stability of mid-sleep scores on both free and workdays sharply increased from young adulthood and reached their peak when participants were in late 40 to early 50 years of age, indicating that age influences the stability of mid-sleep. Future long-term longitudinal studies are necessary to explore how age-related life circumstances and other possible factors may influence the intraindividual variability and temporal stability of mid-sleep

    Site-Selective Excitation And Polarized Absorption Spectra Of Nd3+ In Sr-5(Po4)(3)F And Ca-5(Po4)(3)F

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    Polarized absorption and fluorescence spectra were analyzed to establish individual energy (Stark) levels of Nd3+ ions in host crystals of Sr-5(PO4)(3)F (SFAP) and Ca-5(PO4)(3)F (FAP). Site-selective excitation and fluorescence facilitated differentiation between Nd3+ ions in emitting sites-associated with 1.06 mu m stimulated emission, and nonemitting Nd3+ ions in other sites. Measurements were made on samples containing different concentrations of Nd3+ at 4 K and higher temperatures. Substitution of Nd3+ for Sr2+ or Ca2+ was accompanied by passive charge compensation during crystal growth. Crystal-field splitting calculations were performed according to site for Stark levels of Nd3+ ions identified spectroscopically. We obtained a final set of crystal-field parameters B-nm for Nd3+ ions in fluorescing sites with a rms, deviation of 7 cm(-1) (52 levels in Nd:SFAP) and 8 cm(-1) (59 levels in Nd:FAP). For one of the nonemitting sites in Nd:FAP we obtained a final set of B-nm parameters which gave a rms deviation of 6 cm(-1) between 46 experimental and calculated levels

    Temporal processes in prime–mask interaction: Assessing perceptual consequences of masked information

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    Visual backward masking is frequently used to study the temporal dynamics of visual perception. These dynamics may include the temporal features of conscious percepts, as suggested, for instance, by the asynchronous–updating model (Neumann, 1982) and perceptual–retouch theory ((Bachmann, 1994). These models predict that the perceptual latency of a visual backward mask is shorter than that of a like reference stimulus that was not preceded by a masked stimulus. The prediction has been confirmed by studies using temporal–order judgments: For certain asynchronies between mask and reference stimulus, temporal–order reversals are quite frequent (e.g. Scharlau, & Neumann, 2003a). However, it may be argued that these reversals were due to a response bias in favour of the mask rather than true temporal-perceptual effects. I introduce two measures for assessing latency effects that (1) are not prone to such a response bias, (2) allow to quantify the latency gain, and (3) extend the perceptual evidence from order reversals to duration/interval perception, that is, demonstrate that the perceived interval between a mask and a reference stimulus may be shortened as well as prolonged by the presence of a masked stimulus. Consequences for theories of visual masking such as asynchronous–updating, perceptual–retouch, and reentrant models are discussed

    The Role of Visual Information in Numerosity Estimation

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    Mainstream theory suggests that the approximate number system supports our non-symbolic number abilities (e.g. estimating or comparing different sets of items). It is argued that this system can extract number independently of the visual cues present in the stimulus (diameter, aggregate surface, etc.). However, in a recent report we argue that this might not be the case. We showed that participants combined information from different visual cues to derive their answers. While numerosity comparison requires a rough comparison of two sets of items (smaller versus larger), numerosity estimation requires a more precise mechanism. It could therefore be that numerosity estimation, in contrast to numerosity comparison, might rely on the approximate number system. To test this hypothesis, we conducted a numerosity estimation experiment. We controlled for the visual cues according to current standards: each single visual property was not informative about numerosity. Nevertheless, the results reveal that participants were influenced by the visual properties of the dot arrays. They gave a larger estimate when the dot arrays consisted of dots with, on average, a smaller diameter, aggregate surface or density but a larger convex hull. The reliance on visual cues to estimate numerosity suggests that the existence of an approximate number system that can extract numerosity independently of the visual cues is unlikely. Instead, we propose that humans estimate numerosity by weighing the different visual cues present in the stimuli

    Site-selective excitation and polarized absorption and emission spectra of trivalent thulium and erbium in strontium fluorapatite

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    Polarized fluorescence spectra produced by site-selective excitation, and conventional polarized absorption spectra were obtained for Tm3+ and Er3+ ions individually incorporated into single crystals of strontium fluorapatite, Sr-5(PO4)(3)F, also known as SFAP. Substitution of the trivalent rare earth ion for divalent strontium was achieved by passive charge compensation during Czochralski growth of the fluorapatite crystals. Spectra were obtained between 1780 and 345 nm at temperatures from 4 K to room temperature on crystals having the hexagonal structure [P6(3)/m(C-6h(2))]. The polarized fluorescence spectra due to transitions from multiplet manifolds of Tm3+(4f(12)), including D-1(2), (1)G(4), and H-3(4) to manifolds H-3(6) (the ground-state manifold), F-3(4), H-3(5), H-3(4), and F-3(3) were analyzed for the details of the crystal-field splitting of the manifolds. Fluorescence Lifetimes were measured for Tm3+ transitions from D-1(2), (1)G(4), and H-3(4) at room temperature and from (1)G(4) at 16 K. Results of the analysis indicate that the majority of Tm3+ ions occupy sites having C-s symmetry. A point-charge lattice-sum calculation was made in which the crystal-field components, A(nm), were determined assuming that trivalent thulium replaces divalent strontium in the metal site having C-s symmetry. Results support the conclusion that the nearest-neighbor fluoride (F-) is replaced by divalent oxygen (O2-), thus preserving overall charge neutrality and local symmetry. Crystal-field splitting calculations predict energy levels in agreement with results obtained from an analysis of the experimental data. By varying the crystal-field parameters, B-nm, we obtained a rms difference of 7 cm(-1) between 43 calculated and experimental Stark levels for Tm3+(4f(12)) in Tm:SFAP. Absorption and fluorescence spectra are also reported for Er3+ ions in Er:SFAP. Measurement of the temporal decay of the room temperature fluorescence from the I-4(11/2) and I-4(13/2) manifolds yielded fluorescence lifetimes of 230+/-20 mu s and 8.9+/-0.1 ms, respectively. The experimental Stark levels obtained from an analysis of the spectroscopic data were compared with a crystal-field splitting calculation. The initial set of B-nm parameters for Er3+(4f(11)) was established from the three-parameter theory and the final set of B-nm parameters obtained for Tm3+(4f(12)) in Tm:SFAP. The best overall agreement between calculated and experimental Stark levels is 8 cm(-1) for 48 Stark levels, representing 12 observed multiplet manifolds of Er3+(4f(11)) in Er:SFAP
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