Intervention for a lexical reading and spelling difficulty in two Greek-speaking primary age children

An intervention study was carried out with two nine-year-old Greek-speaking dyslexic children. Both children were slow in reading single words and text and had difficulty in spelling irregularly spelled words. One child was also poor in non-word reading. Intervention focused on spelling in a whole-word training using a flashcard technique that had previously been found to be effective with English-speaking children. Post-intervention assessments conducted immediately at the end of the intervention, one month later and then five months later showed a significant improvement in spelling of treated words that was sustained over time. In addition, both children showed generalisation of improvement to untrained words and an increase in scores in a standardised spelling assessment. The findings support the effectiveness of theoretically based targeted intervention for literacy difficulties

Intervention for a visual attention span processing deficit in a Greek-speaking child with slow reading speed

We present the case of TN, aged 9;11, a monolingual Greek-speaking girl with accurate but slow word and non-word reading. Neuropsychological assessment revealed a selective deficit in visual attention span (VAS) tasks. TN had previously taken part in a spelling intervention targeting whole word processing and, although her spelling improved, at the end of the programme, her reading remained slow. In the present study, we assessed TN in a lexical decision task with semantic primes, and she showed reduced semantic priming in relation to typically developing readers. TN took part in an intervention aimed at mitigating the VAS processing deficit and similar to a programme previously conducted with a twelve- year-old Greek-speaking boy, RF (Niolaki & Masterson, 2013). Post-test results for TN revealed a significant improvement in letter report ability, as well as a reduction in word reading latencies; semantic facilitation was also observed in the priming task following the intervention, although pre- and post-intervention differences were not significant. The results indicate, in line with previous research, an association between visual attention span and reading speed

Greek-spelling predictors; an investigation of literacy- and cognitive-related factors

Greek spelling has been less explored than reading, and studies looking at predictors have primarily focused on phonological ability (PA) and rapid automatised naming (RAN). Few studies have been conducted on visual attention span (VAS), although there is growing acknowledgement that spelling involves processes other than phonological ones. We investigated single-word spelling accuracy cross-sectionally with 145 students attending Grades 1–7 in Greece. We conducted regression analyses for the beginner and more advanced spellers separately. We found that only PA was a significant predictor for the beginner spellers after controlling for reading speed and chronological age. For the more advanced spellers, VAS and RAN were significant predictors in addition to PA. The outcome suggests that as the children gain more spelling experience, phonological and visual processes are important. Analyses of the effects on spelling accuracy of the item-related variables printed word frequency and phoneme-grapheme probability supported those obtained from the child-related analyses. The educational implications of the findings are discussed

What spelling errors can tell us about the development of processes involved in children’s spelling

Introduction: Spelling is an essential foundation for reading and writing. However, many children leave school with spelling difficulties. By understanding the processes children use when they spell, we can intervene with appropriate instruction tailored to their needs. Methods: Our study aimed to identify key processes (lexical-semantic and phonological) by using a spelling assessment that distinguishes different printed letter strings/word types (regular and irregular words, and pseudowords). Misspellings in the test from 641 pupils in Reception Year to Year 6 were scored using alternatives to binary correct versus incorrect scoring systems. The measures looked at phonological plausibility, phoneme representations and letter distance. These have been used successfully in the past but not with a spelling test that distinguishes irregularly spelled words from regular words and pseudowords. Results: The findings suggest that children in primary school rely on both lexical-semantic and phonological processes to spell all types of letter string, but this varies depending on the level of spelling experience (younger Foundation/Key stage 1 and older Key stage 2). Although children in younger year groups seemed to rely more on phonics, based on the strongest correlation coefficients for all word types, with further spelling experience, lexical processes seemed to be more evident, depending on the type of word examined. Discussion: The findings have implications for the way we teach and assess spelling and could prove to be valuable for educators

What spelling errors can tell us about the development of processes involved in children's spelling

Spelling is an essential foundation for reading and writing. However, many children leave school with spelling difficulties. By understanding the processes children use when they spell, we can intervene with appropriate instruction tailored to their needs. Our study aimed to identify key processes (lexical-semantic and phonological) by using a spelling assessment that distinguishes different printed letter strings/word types (regular and irregular words, and pseudowords). Misspellings in the test from 641 pupils in Reception Year to Year 6 were scored using alternatives to binary correct versus incorrect scoring systems. The measures looked at phonological plausibility, phoneme representations and letter distance. These have been used successfully in the past but not with a spelling test that distinguishes irregularly spelled words from regular words and pseudowords. The findings suggest that children in primary school rely on both lexical-semantic and phonological processes to spell all types of letter string, but this varies depending on the level of spelling experience (younger Foundation/Key stage 1 and older Key stage 2). Although children in younger year groups seemed to rely more on phonics, based on the strongest correlation coefficients for all word types, with further spelling experience, lexical processes seemed to be more evident, depending on the type of word examined. The findings have implications for the way we teach and assess spelling and could prove to be valuable for educators

Persistence within dendritic cells marks an antifungal evasion and dissemination strategy of Aspergillus terreus

Aspergillus terreus is an airborne human fungal pathogen causing life-threatening invasive aspergillosis in immunocompromised patients. In contrast to Aspergillus fumigatus, A. terreus infections are associated with high dissemination rates and poor response to antifungal treatment. Here, we compared the interaction of conidia from both fungal species with MUTZ-3-derived dendritic cells (DCs). After phagocytosis, A. fumigatus conidia rapidly escaped from DCs, whereas A. terreus conidia remained persisting with long-term survival. Escape from DCs was independent from DHN-melanin, as A. terreus conidia expressing wA showed no increased intracellular germination. Within DCs A. terreus conidia were protected from antifungals, whereas A. fumigatus conidia were efficiently cleared. Furthermore, while A. fumigatus conidia triggered expression of DC activation markers such as CD80, CD83, CD54, MHCII and CCR7, persistent A. terreus conidia were significantly less immunogenic. Moreover, DCs confronted with A. terreus conidia neither produced pro-inflammatory nor T-cell stimulating cytokines. However, TNF-α addition resulted in activation of DCs and provoked the expression of migration markers without inactivating intracellular A. terreus conidia. Therefore, persistence within DCs and possibly within other immune cells might contribute to the low response of A. terreus infections to antifungal treatment and could be responsible for its high dissemination rates

Modeling allosteric signal propagation using protein structure networks

Allosteric communication in proteins can be induced by the binding of effective ligands, mutations or covalent modifications that regulate a site distant from the perturbed region. To understand allosteric regulation, it is important to identify the remote sites that are affected by the perturbation-induced signals and how these allosteric perturbations are transmitted within the protein structure. In this study, by constructing a protein structure network and modeling signal transmission with a Markov random walk, we developed a method to estimate the signal propagation and the resulting effects. In our model, the global perturbation effects from a particular signal initiation site were estimated by calculating the expected visiting time (EVT), which describes the signal-induced effects caused by signal transmission through all possible routes. We hypothesized that the residues with high EVT values play important roles in allosteric signaling. We applied our model to two protein structures as examples, and verified the validity of our model using various types of experimental data. We also found that the hot spots in protein binding interfaces have significantly high EVT values, which suggests that they play roles in mediating signal communication between protein domains

Novel Cβ–Cγ Bond Cleavages of Tryptophan-Containing Peptide Radical Cations

In this study, we observed unprecedented cleavages of the Cβ–Cγ bonds of tryptophan residue side chains in a series of hydrogen-deficient tryptophan-containing peptide radical cations (M•+) during low-energy collision-induced dissociation (CID). We used CID experiments and theoretical density functional theory (DFT) calculations to study the mechanism of this bond cleavage, which forms [M – 116]+ ions. The formation of an α-carbon radical intermediate at the tryptophan residue for the subsequent Cβ–Cγ bond cleavage is analogous to that occurring at leucine residues, producing the same product ions; this hypothesis was supported by the identical product ion spectra of [LGGGH – 43]+ and [WGGGH – 116]+, obtained from the CID of [LGGGH]•+ and [WGGGH]•+, respectively. Elimination of the neutral 116-Da radical requires inevitable dehydrogenation of the indole nitrogen atom, leaving the radical centered formally on the indole nitrogen atom ([Ind]•-2), in agreement with the CID data for [WGGGH]•+ and [W1-CH3GGGH]•+; replacing the tryptophan residue with a 1-methyltryptophan residue results in a change of the base peak from that arising from a neutral radical loss (116 Da) to that arising from a molecule loss (131 Da), both originating from Cβ–Cγ bond cleavage. Hydrogen atom transfer or proton transfer to the γ-carbon atom of the tryptophan residue weakens the Cβ–Cγ bond and, therefore, decreases the dissociation energy barrier dramatically

Spelling improvement through letter-sound and whole-word training in two multilingual Greek- and English- speaking children

Case studies of two children with spelling difficulty are reported. LK was multilingual and ED bilingual. A training programme that targeted phonic decoding (or sublexical) spelling processes was conducted with both children. Immediate and delayed post-training assessments showed improvement in spelling nonwords for LK but not for ED. Training that targeted whole word (or lexical) spelling processes was then conducted with ED. Improvement in spelling of irregular words (a marker for lexical spelling processes) was observed. Research into literacy difficulties with multilingual children is sparse, although multilingualism is increasingly widespread. Up to now theoretically based training studies have focused on monolingual children and results were promising. The present findings indicate that theoretically based training programmes for literacy difficulties can also be effective for multilingual children