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Technological reading and writing tools can help students with dyslexia improve their writing, but students do not use reading and writing functions as much as expected. However, research addressing relevant technological functions is scarce. This study explored the needs of writers with dyslexia and how technological writing tools developed for three Nordic languages meet these needs. Snowball sampling was used to identify different technological features, spellchecker, word prediction, auto-correction, text-to-speech and speech-to-text functions available in nine widely used programmes were investigated. The results indicated that students with moderate spelling difficulties can now achieve accurate spellings using the most sophisticated spelling aids; however, most of these features require time and attention, and this can disturb writing fluency and hamper text production. The implication of this study is that the underlying conflict between spelling accuracy and writing fluency must be actively managed, which necessitates competence in the use of technological tools for both students and teachers in school. Also, further development of tools for scaffolding transcription must consider the dilemma of achieving both writing fluency and spelling accuracy. Further, the accuracy of the aid for students with severe spelling difficulties remains unclear and must be investigated.
Assuntos
Dislexia , Humanos , Dislexia/diagnóstico , Leitura , Redação , Estudantes , EscolaridadeRESUMO
FeSb2 exhibits a colossal Seebeck coefficient ( S ) and a record-breaking high thermoelectric power factor. It also has an atypical shift from diamagnetism to paramagnetism with increasing temperature, and the fine details of its electron correlation effects have been widely discussed. The extraordinary physical properties must be rooted in the nature of the chemical bonding, and indeed, the chemical bonding in this archetypical marcasite structure has been heavily debated on a theoretical basis since the 1960s. The two prevalent models for describing the bonding interactions in FeSb2 are based on either ligand-field stabilization of Fe or a network structure of Sb hosting Fe ions. However, neither model can account for the observed properties of FeSb2 . Herein, an experimental electron density study is reported, which is based on analysis of synchrotron X-ray diffraction data measured at 15â K on a minute single crystal to limit systematic errors. The analysis is supplemented with density functional theory calculations in the experimental geometry. The experimental data are at variance with both the additional single-electron Sb-Sb bond implied by the covalent model, and the large formal charge and expected d-orbital splitting advocated by the ionic model. The structure is best described as an extended covalent network in agreement with expectations based on electronegativity differences.
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Studies report that speech-to-text applications (STT) may support students with writing difficulties in text production. However, existing research is sparse, shows mixed results, and lacks information on STT interventions and their applicability in schools. Therefore, this study aimed to investigate whether a systematic and intensive assistive technology intervention focusing on STT can improve text production. A modified multiple-baseline across-subject design was used involving eight middle school students, four Norwegian and four Swedish. Their STT-produced narrative texts were collected during and after the intervention and the productivity, accuracy, and text quality were analysed. Keyboarding was the baseline control condition. The results demonstrated that seven of the eight students increased text productivity and that the proportion of word-level accuracy was maintained or improved. The use of punctuation progressed in participants with poor baseline skills. Most students' STT-produced texts had at least a similar ratio of meaningfulness and text quality as keyboarding. However, the magnitude of the changes and development patterns varied, with three students showing the most notable impacts. In conclusion, this study's intervention seemed beneficial in initially instructing STT, and the progress monitoring guided individually adapted future interventions such as balancing productivity and formal language aspects. Removing the spelling barrier with STT provided an opportunity for students to improve their higher-order skills, such as vocabulary diversity and overall text quality. Furthermore, visible progress, such as the ability to produce longer texts, might motivate continued STT usage. However, such development may not always be immediate.
Speech-to-text (STT) may be an effective tool for developing text production in students with severe reading and writing difficulties. For example, enhanced text length can provide teachers with more material for feedback, guiding students towards improved text production.Text-to-speech may further enhance the usefulness of STT in text production by facilitating the revision process through listening to produced sentences and texts.By continuously monitoring students' STT usage and text production, teachers can tailor the content for further interventions to address individual needs such as sentence construction and text planning.Early STT intervention seems beneficial, allowing more time to practise advanced skills in text production when bypassing spelling.
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Single crystal synchrotron X-ray diffraction measurements have been carried out on [Nd(DMF)(4)(H(2)O)(3)(µ-CN)Fe(CN)(5)]·H(2)O (DMF = dimethyl-formamide), 1; [Y(DMF)(4)(H(2)O)(3)(µ-CN)Fe(CN)(5)]·H(2)O, 2; [Ce(DMF)(4)(H(2)O)(3)(µ-CN)Fe(CN)(5)]·H(2)O, 3; [Sm(DMF)(4)(H(2)O)(3)(µ-CN)Fe(CN)(5)]·H(2)O, 4; [Tb(DMF)(4)(H(2)O)(3)(µ-CN)Fe(CN)(5)]·H(2)O, 5; [Yb(DMF)(4)(H(2)O)(3)(µ-CN)Fe(CN)(5)]·H(2)O, 6; and [Nd(DMF)(4)(H(2)O)(3)(µ-CN)Co(CN)(5)]·H(2)O, 7, at 15(2) K with and without UV illumination of the crystals. Significant changes in unit cell parameters are observed for all of the iron-containing complexes, while compound 7 shows no response to UV illumination. These results are consistent with previous results and are furthermore reproduced by powder synchrotron X-ray diffraction for compounds 1 and 7. Photoexcited crystal structures have been determined for 1-6 from refinements of two-conformer models, and excited state occupancies in the range 80-94% are found. Significant bond length changes are observed for the Fe-ligand bonds (up to 0.06 Å), the cyano bonds (up to 0.02 Å), and the lanthanide-ligand bonds (up to 0.1 Å). On the contrary, powder X-ray diffraction on the simple compound K(3)Fe(CN)(6), 8, upon UV illumination does not show any structural changes, suggesting that the photomagnetic effect requires the presence of both the transition metal and the lanthanide ion. Photomagnetic measurements show an increase in magnetization of the excited state of 1 of up to 3%, which is much diminished compared with previously published values of 45%. Furthermore, they show that the isostructural complex [La(DMF)(4)(H(2)O)(3)(µ-CN)Fe(CN)(5)]·H(2)O, 9, exhibits identical magnetic responses in the UV-induced excited crystal structure.
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Single-crystal X-ray diffraction measurements have been carried out on [Nd(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (1; dmf=dimethylformamide), [Nd(dmf)(4)(H(2)O)(3)(mu-CN)Co(CN)(5)].H(2)O (2), [La(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (3), [Gd(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (4), and [Y(dmf)(4)(H(2)O)(3)(mu-CN)Fe(CN)(5)].H(2)O (5), at 15(2) K with and without UV illumination of the crystals. Significant changes in unit-cell parameters were observed for all the iron-containing complexes, whereas 2 showed no response to UV illumination. Photoexcited crystal structures have been determined for 1, 3, and 4 based on refinements of two-conformer models, and excited-state occupancies of 78.6(1), 84(6), and 86.6(7)% were reached, respectively. Significant bond-length changes were observed for the Fe-ligand bonds (up to 0.19 A), the cyano bonds (up to 0.09 A), and the lanthanide-ligand bonds (up to 0.10 A). Ab initio theoretical calculations were carried out for the experimental ground-state geometry of 1 to understand the electronic structure changes upon UV illumination. The calculations suggest that UV illumination gives a charge transfer from the cyano groups on the iron atom to the lanthanide ion moiety, {Nd(dmf)(4)(H(2)O)(3)}, with a distance of approximately 6 A from the iron atom. The charge transfer is accompanied by a reorganization of the spin state on the {Fe(CN)(6)} complex, and a change in geometry that produces a metastable charge-transfer state with an increased number of unpaired electrons, thus accounting for the observed photomagnetic effect.
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X-ray vision: Single-crystal XRD experiments (see picture) reveal the excited-state structure of the photomagnetic heterobimetallic title complex. The system shows a decrease in all the iron-ligand bond lengths, suggesting that photoexcitation involves a ligand-to-metal charge transfer or a change in the superexchange coupling between the metal centers.
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Recently Henn & Meindl [Acta Cryst. (2010), A66, 676-684] examined the significance of Bragg diffraction data through the descriptor W = (I(1/2))/(σ(I)). In the Poisson limit for the intensity errors W equals unity, but any kind of data processing (background subtraction, integration, scaling, absorption correction, Lorentz and polarization correction etc.) introduces additional error as well as remaining systematic errors and thus the significance of processed Bragg diffraction data is expected to be below the Poisson limit (W(Bragg) < 1). Curiously, it was observed by Henn & Meindl for several data sets that W(Bragg) had values larger than one. In the present study this is shown to be an artefact due to the neglect of a data scale factor applied to the standard uncertainties, and corrected values of W(Bragg) applied to Bragg data on an absolute scale are presented, which are all smaller than unity. Furthermore, the error estimation models employed by two commonly used data-processing programs {SADABS (Bruker AXS Inc., Madison, Wisconsin, USA) and SORTAV [Blessing (1997). J. Appl. Cryst. 30, 421-426]} are examined. It is shown that the empirical error model in SADABS very significantly lowers the significance of the Bragg data and it also results in a very strange distributions of errors, as observed by Henn & Meindl. On the other hand, error estimation based on the variance of a population of abundant intensity data, as used in SORTAV, provides reasonable error estimates, which are only slightly less significant than the raw data. Given that modern area detectors make measurement of highly redundant data relatively straightforward, it is concluded that the latter is the best approach for processing of data.
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The excited state crystal structure of the ionic complex (Nd(DMA)(4)(H(2)O)(4)-Fe(CN)(6)·3H(2)O (DMA = dimethylacetamide) has been determined at 15 K upon UV illumination by single crystal X-ray diffraction. Significant structural changes are observed around the Fe site in the excited state. These changes are similar to those observed for a related molecular compound exhibiting photomagnetic properties.