131,399 research outputs found
Identifying developmental coordination disorder: MOQ-T validity as a fast screening instrument based on teachers' ratings and its relationship with praxic and visuospatial working memory deficits.
No full textThe present study was devoted to test the validity of the Italian adaptation of the Motor Observation Questionnaire for Teachers (MOQ-T, Schoemaker, Flapper, Reinders-Messelink, & De Kloet, 2008) as a fast screening instrument, based on teachers' ratings, for detecting developmental coordination disorders symptoms and to study its relationship with praxic and visuospatial working memory deficits. In a first study on a large sample of children, we assessed the reliability and structure of the Italian adaptation of the MOQ-T. Results showed a good reliability of the questionnaire and a hierarchical structure with two first-order factors (reflecting motor and handwriting skills), which are influenced by a second-order factor (general motor function) at the top. In a second study, we looked at the external validity of the MOQ-T and found that children with symptoms of Developmental Coordination Disorder (children with high scores on the MOQ-T) also had difficulty reproducing gestures, either imitating others or in response to verbal prompts. Our results also showed that children with high MOQ-T scores had visuospatial WM impairments. The theoretical and clinical implications of these findings are discussed
Manuscripten van H.J. Schoemaker uit de periode 1946-1971: Deel D: Golven van het wateroppervlak
No full textD1: Golven van het wateroppervlak, grondformules in eerste benadering (1956) D2: Golfvervorming door wind; overzicht van de ontwikkelingen tot 1955 (1955) D3: Second-order effects in progressinve surface waves (1961) D4: Golven in stromend water (1960) D5: Diffractie (1950) D6: Investigations of the reflection of waves (1949)Hydraulic EngineeringCivil Engineering and Geoscience
Italian adaptation of the MOQ-T as a fast screening instrument based on teachers' ratings for identifying developmental coordination disorder symptoms
No full textThe present study was designed to collect data on the Italian adaptation of the Motor Observation Questionnaire for Teachers (MOQ-T, Schoemaker, Flapper, Reinders-Messelink, & De Kloet, 2008). We provide data for 2nd, 3rd, 4th and 5th grades, in some cases distinguishing males from females. On the basis of the present and previous evidence (Giofrè et al., 2014) the MOQ-T appears a valid and a fast screening instrument for detecting developmental coordination disorders (DCD) symptoms (on the basis of teachers' ratings) in children and can be very important as a first step in the process for diagnosing DCD
Vibrational relaxation of the F center in NaI and NaBr
No full textHigh-resolution Raman measurements have been performed to study the coupling of lattice modes to the F center in NaBr and NaI. In both cases, a prominent line near or in the region of the energy gap between the acoustic and optical phonon bands dominates the Raman spectrum. Its linewidth was measured and extrapolated to 0 K it turned out to be about 3 and 0.5 cm-1, respectively, for NaBr and NaI. These values are related to the lifetime of the local vibrational excitations, showing a relatively fast vibrational relaxation. Calculating the nonradiative transition probability during the vibrational relaxation in the electronic excited state, the efficiency of reaching the relaxed excited state (RES) of the F center is analyzed. The calculations show that, if the experimental value of the vibrational lifetime is used, the model predicts a high probability of reaching the RES in the case of NaBr. In the case of NaI the prediction strongly depends on the choice of the electronic matrix element for the interstate nonradiative transition. By comparison with similar cases of vibronic transition matrix elements reported in the literature, the efficiency of reaching the RES in NaI is expected in the range 0.05 to 1. © 1994 The American Physical Society
Radiationless electronic relaxation of the F center in NaI
No full textThe temperature dependence of the ground-state recovery of the F-center in NaI after optical excitations is studied with a pump-probe laser technique. At 10 K the lifetime of the relaxed excited state (tens of ns) is identified together with a much smaller 10 ps contribution possibly related to the Dexter-Klick-Russell cross-over process. © 1994
Evidence for the crossover process after optical excitation of the F center in NaI
No full textGround-state recovery measurements on the F center in NaI were performed with time resolutions of both 7 ps and 200 fs. The measurements confirm the expectation of an electronic relaxation with a decay time of the order of tens of nanoseconds, which can be associated with a nonradiative transition from the relaxed excited state (RES) at low temperatures. Different from the case of NaBr, the decay channel related to the recapture of conduction electrons cannot clearly be distinguished. This is possibly related to the fact that the available time delay is considerably shorter than the ground-state recovery in the temperature range in which the dominant contribution changes from the component related to the RES lifetime to the retrapping component. Measurements of the ground-state recovery with a 200-fs time resolution show that a very fast relaxation component is present for the F center in NaI. It possesses a time constant of 9 ps at low temperature and its relative contribution with respect to the total induced transparency signal is roughly 33%. The temperature dependence of its time constant follows closely the vibrational lifetime derived from linewidth measurements of the resonant Raman spectrum. This feature is expected for the contribution to the induced transparency arising from an electronic transition during vibrational relaxation, the so-called crossover process. © 1994 The American Physical Society
Relaxation and transfer processes of perturbed and unperturbed F centers studied with picosecond optical pulses.
No full textNonradiative relaxation and ionization of the F center in NaBr studied with picosecond optical pulses
No full textWith a picosecond pump-probe laser technique the recovery of the ground-state population after optical excitation of the F center in NaBr is studied. Two decay components are observed, the fastest one dominating at low temperatures. Its time constant is interpreted as the lifetime of the relaxed excited state and is established to be 61 ns at 10 K. This value is perfectly consistent with the experimental emission efficiency and the expected radiative lifetime, provided that the nonradiative transition to the ground state is assumed to occur after the relaxed excited state is reached. Within the same assumptions a nonradiative lifetime of 27 ns at zero temperature is predicted for the F center in NaI. A theoretical expression for vibronic tunneling to the ground state from a thermalized excited state is applied to the F center in alkali halides and is shown to agree equally well with the experimental emission efficiencies as the Dexter-Klick-Russell criterion. The same expression also accounts for the strong temperature dependence of the nonradiative relaxation process observed in NaBr below 100 K. At higher temperatures an accurate analysis of the radiationless transition rate is encumbered by the influence of ionization on the lifetime of the excited state. The relative contribution of the second, much slower decay component increases rapidly above 70 K and is related to retrapping of electrons released by ionization of F and F centers. © 1992 The American Physical Society
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
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