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We examined the effects of a morphological awareness (MA) training program on the enhancement of word and pseudo-word reading and phonological awareness in Arabic-speaking children with dyslexia. We compared two groups of children with dyslexia from Grade 3, an experimental group (n = 12; mean age = 112.4 months) with a control group (n = 13; mean age = 111.61 months). The training program focused on morphological analysis, derivational morphology and inflexional morphology. Results revealed that the experimental group outperformed controls on all post-training measures for MA, reading words and pseudo-words as well as phonological awareness. Also, the post-training measures were better achieved in the experimental group than pre-training ones, which confirm the efficacy of the morphological training program. We discuss these findings in light of the relationship between morphological awareness and word reading and phonological awareness, and the Arabic orthographic features as a morphological based language.

Although the link between developmental dyslexia and visual-spatial deficit has been recurrently highlighted, the relationship between visual-spatial abilities and reading performance is still a controversial issue, considering the orthographic variability of the language being learned. This study aimed to examine whether visuo-spatial abilities (i.e. attention, short-term memory, and relations) contribute significantly to predicting word and pseudo-word reading independently of phonological awareness in Arabic speaking children in grades 4 and 5. An inter-groups comparison between two groups of readers comprising typical readers (n = 44) and children with dyslexia (n = 32). All participants were tested in phonological (phonological awareness) and visuo-spatial measures (visual short-term memory test, visuo-spatial attention, and visuo-spatial relations). Results showed that typical readers outperformed the group of dyslexics in all the phonological and visuo-spatial measures. Visuo-spatial abilities were also a contributing factor in predicting word reading after controlling for phonological awareness, age, and non-verbal reasoning. Findings indicate that vowelised word reading in Arabic is heavily underpinned by phonological awareness and visuo-spatial abilities, found to be impaired in a group with dyslexia. Findings are viewed in the frame that reveals the integrated roles of phonological awareness and visual and spatial abilities in reading development.

We examined the effects of a combined phonological and print intervention program on the enhancement of phonological awareness, text reading accuracy and comprehension in fourth grade Arabic-speaking children with severe difficulties in reading accuracy (dyslexia) and reading comprehension. We compared an experimental group (n = 22; mean age = 122.9 months) to a control group (n = 22; mean age = 124.65 months). The training program focused on two domains: phonological awareness and print knowledge. The results showed that the experimental group performed better in the post and follow-up assessments than in the baseline assessment on phonological awareness, reading accuracy, and comprehension. We discuss findings indicating the positive impact of phonological awareness and print knowledge on reading development in terms of decoding and comprehension abilities.

We report the results of three tasks of two-dimensional pictures, letters and symbols mental rotation (MR) among 9-11 years aged Arabic readers with dyslexia, in order to examine a potential stimulus type effect on MR ability in terms of accuracy and speed. Results showed that readers with dyslexia (n = 32) performed significantly lower and were slower than typical readers (n = 44) in the three MR tasks. Furthermore, 'group' and 'type of stimuli' effects were obtained for accuracy and speed of MR implementation, indicating impaired visual spatial orientation processing in children with dyslexia. Furthermore, repeated measures of ANOVA showed that letter MR is significantly slower than pictures and symbols in dyslexic group but no difference in terms of accuracy. These results are interpreted as support for the notion of linguistic based mental rotation impairment in developmental dyslexia, without being restricted to orthographic material.

We predicted that Arabic-speaking children with specific learning disabilities in reading (dyslexia) and spelling (in writing) benefit from a visuomotor-based intervention programme for the development of letter knowledge and the improvement of word and pseudo-word decoding as well as spelling (dictation). It was predicted that the mediation of visuomotor training should be effective since the characteristics of Arabic script require such high-level functioning for the development of literacy skills. Participants (n = 20) were randomly divided in two groups, an experimental group (n = 10; mean age =125.50 months ± 3.24) and a control group (n = 10; mean age = 124.10 months ± 3.31). Results revealed that the post-intervention measures were better achieved in the experimental group than pre-intervention ones, which confirms the efficacy of this visuomotor intervention programme.

In this study, we conducted a lexical decision test using masked priming paradigm to examine the morphological and orthographic priming effects in word recognition. Morphologically related word pairs can be derivational, sharing the same root or not (pseudo derivational). However, the orthographically related pairs share the same letters in different positions. Two groups of native Arabic-speaking children (N = 57) from grade 4 and 5 participated in this study: typical readers (n = 39) and dyslexic readers (n = 18). To examine whether a potential morphological priming effect is driven by semantic or orthographic properties of shared morphemes, we compared prime-target pairs with derivation morphology and pseudo-derivation word related pairs. Between groups comparisons showed that a priming effect occurred only in typical readers. Comparisons between conditions revealed that a priming effect only occurred for accuracy in derivational morphology. No priming effect occurred in reaction times (RTs) between groups or conditions. These results provide evidence for root-based word recognition in Arabic children and give support to semantically rather than orthographically driven lexical access.

We examined the effects of an adaptive phonological training program on the enhancement of 3 processing abilities--namely, phonological awareness, rapid automatized naming, and phonological short-term memory--as well as word and pseudoword reading in Arabic-speaking children with dyslexia. We compared an experimental group (n = 20; mean age = 122.9 months) to a control group (n = 20; mean age = 124.65 months) from Grades 4 and 5. The phonological training program focused on the mental representation of phonemes, their identity, and their positions in words. The experimental group outperformed controls on all posttraining measures for reading words and pseudowords as well as phonological processing components. We discuss findings indicating a strong relationship between phonological processing and reading efficiency in terms of reading-related skills gained through training.

Background: Understanding stand dynamics is essential for predicting future wood supply and associated ecosystem services for sustainable forest management. The dynamics of natural stands can be characterized by agedependent growth and yield models. However, dynamics in managed stands appear somewhat different from that of natural stands, especially with difficulties in explaining the phenomenon of post-thinning overcompensation, based upon some long-term observations. Though overcompensation is an ideal outcome for the forest sector, it had been largely treated as an outlier and thus ignored or dismissed as "out-of-the-ordinary". Methodology: We developed a life history theory-based, state-dependent model of Tree Adaptive Growth (TAG) to investigate this phenomenon and verified that overcompensation should be a common outcome in postthinning forest stands when the stand growth over time is sigmoid shaped. TAG posits that individual trees will invest proportionately more into growth following thinning because it is evolutionarily adaptive to do so. Results: Our investigation of the model's behavior unearthed diverse stand growth patterns similar to that which is observed in the empirical datasets and predicted by a statistics-based Tree's Compensatory Growth (TreeCG) model. Conclusion: A simple, theory-driven, analytical model, TAG, can reproduce the diverse growth patterns in post-thinning stands and thus assist addressing silviculture-related issues. The model can be applied to various jurisdictions even without detailed regional growth and yield relationships and is capable of incorporating the effects of other time sensitive factors like fertilization, pruning, and climate change. [ABSTRACT FROM AUTHOR]

This study explored the role and extent of the involvement of morphological awareness (MA) in contrast to rapid automatized naming (RAN) in word reading and comprehension of Arabic as a morphologically based orthography. We gave measures of word reading, reading comprehension, MA, and RAN in addition to a nonverbal mental ability test to 3 groups of readers: a group with dyslexia (n = 20) from the 6th grade compared to a group of normal readers matched in age (n = 20) and a younger reader group from the 4th grade (n = 18). Results indicated that RAN was a significant predictor of word reading and reading comprehension, whereas MA explained only the variance in reading comprehension. We conclude that RAN and MA have important roles in predicting reading skills, and we suggest that they should be included more frequently in assessments and instruction.

DST is a gene whose alternative splicing yields epithelial, neuronal, and muscular isoforms. The autosomal recessive Dstdt (dystonia musculorum) spontaneous mouse mutation causes degeneration of spinocerebellar tracts as well as peripheral sensory nerves, dorsal root ganglia, and cranial nerve ganglia. In addition to Dstdt mutants, axonopathy and neurofilament accumulation in perikarya are features of two other murine lines with spontaneous Dst mutations, targeted Dst knockout mice, DstTg4 transgenic mice carrying two deleted Dst exons, DstGt mice with trapped actin-binding domain-containing isoforms, and conditional Schwann cell-specific Dst knockout mice. As a result of nerve damage, Dstdt mutants display dystonia and ataxia, as seen in several genetically modified models and their motor coordination deficits have been quantified along with the spontaneous Dst nonsense mutant, the conditional Schwann cell-specific Dst knockout, the conditional DstGt mutant, and the Dst-b isoform specific Dst mutant. Recent findings in humans have associated DST mutations of the Dst-b isoform with hereditary sensory and autonomic neuropathies type 6 (HSAN-VI). These data should further encourage the development of genetic techniques to treat or prevent ataxic and dystonic symptoms. [ABSTRACT FROM AUTHOR]