5 research outputs found

    Reading and visual word recognition ability in semantic dementia is not predicted by semantic performance

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    This paper describes longitudinal testing of two Semantic Dementia (SD) cases. It is common for patients with SD to present with deficits in reading aloud irregular words (i.e. surface dyslexia), and in lexical decision. Theorists from the connectionist tradition (e.g. Woollams et al., 2007) argue that in SD cases with concurrent surface dyslexia, the deterioration of irregular word reading and recognition performance is related to the extent of the deterioration of the semantic system. The Dual Route Cascaded model (DRC; Coltheart et al., 2001) makes no such prediction. We examined this issue using a battery of cognitive tests and two structural scans undertaken at different points in each cases time course. Across both cases, our behavioural testing found little evidence of a key putative link between semantic impairment and the decline of irregular word reading or lexical decision. In addition, our neuroimaging analyses suggested that it may be the emergence of atrophy to key neural regions both inside and outside the anterior temporal lobes that may best capture the emergence of impairments of irregular word reading, and implicated inferior temporal cortex in surface dyslexia

    Spelling-to-sound correspondences affect acronym recognition processes

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    A large body of research has examined the factors which affect the speed with which words are recognised in lexical decision tasks. Nothing has yet been reported concerning the important factors in differentiating acronyms (e.g. BBC, HIV, NASA) from non-words. It appears that this task poses little problem for skilled readers, in spite of the fact that acronyms have uncommon, even illegal, spellings in English. We used regression techniques to examine the role of a number of lexical and non-lexical variables known to be important in word processing in relation to lexical decision for acronym targets. Findings indicated that acronym recognition is affected by age of acquisition and imageability. In a departure from findings in word recognition,acronym recognition was not affected by frequency. Lexical decision responses for acronyms were also affected by the relationship between spelling and sound - a pattern not usually observed in word recognition. We argue that the complexity of acronym recognition means that the process draws phonological information in addition to semantics

    Tex19.1 Promotes Spo11-Dependent Meiotic Recombination in Mouse Spermatocytes

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    Meiosis relies on the SPO11 endonuclease to generate the recombinogenic DNA double strand breaks (DSBs) required for homologous chromosome synapsis and segregation. The number of meiotic DSBs needs to be sufficient to allow chromosomes to search for and find their homologs, but not excessive to the point of causing genome instability. Here we report that the mammal-specific gene Tex19.1 promotes Spo11-dependent recombination in mouse spermatocytes. We show that the chromosome asynapsis previously reported in Tex19.1-/- spermatocytes is preceded by reduced numbers of recombination foci in leptotene and zygotene. Tex19.1 is required for normal levels of early Spo11-dependent recombination foci during leptotene, but not for upstream events such as MEI4 foci formation or accumulation of H3K4me3 at recombination hotspots. Furthermore, we show that mice carrying mutations in Ubr2, which encodes an E3 ubiquitin ligase that interacts with TEX19.1, phenocopy the Tex19.1-/- recombination defects. These data suggest that Tex19.1 and Ubr2 are required for mouse spermatocytes to accumulate sufficient Spo11-dependent recombination to ensure that the homology search is consistently successful, and reveal a hitherto unknown genetic pathway promoting meiotic recombination in mammals

    Drivers of training and talent development: insights from oil and gas MNCs in Nigeria

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    The paper examines the main drivers, nature and extent of employee training in oil and gas (O&G) multinational companies (MNCs). Using insights from 16 managers in Nigeria O&G industry, we identified three broad levels of factors driving the training provisions and talent development decisions. The study further develops an integrated model of direct and moderating factors of training. The findings suggest that government regulations, health and safety concerns, industry-education outreach programmes and the general level of industry tend to trigger proactive measures in developing relevant training programmes. Moreover, the findings demonstrate that organizations’ strategies, policies, health and safety concerns and technological changes also influence training decision-making. The practical implications of the study as well as implications for training and development research are discussed
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