286 research outputs found

    Bonding in MgSi and AlMgSi Compounds Relevant to AlMgSi Alloys

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    The bonding and stability of MgSi and AlMgSi compounds relevant to AlMgSi alloys is investigated with the use of (L)APW+(lo) DFT calculations. We show that the β\beta and β\beta'' phases found in the precipitation sequence are characterised by the presence of covalent bonds between Si-Si nearest neighbour pairs and covalent/ionic bonds between Mg-Si nearest neighbour pairs. We then investigate the stability of two recently discovered precipitate phases, U1 and U2, both containing Al in addition to Mg and Si. We show that both phases are characterised by tightly bound Al-Si networks, made possible by a transfer of charge from the Mg atoms.Comment: 11 pages, 30 figures, submitted to Phys. Rev.

    Downregulation of chloroplast protease AtDeg5 leads to changes in chronological progression of ontogenetic stages, leaf morphology and chloroplast ultrastructure in Arabidopsis

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    The chloroplast protein AtDeg5 is a serine-type protease peripherally attached to thylakoid membrane at its lumenal side. Since reliable data regarding the role of AtDeg5 in controlling the course of growth and developmental processes are extremely limited, two independent T-DNA insertional lines with different extent of AtDeg5 reduction were prepared and ontogenesis stage-based analysis performed. Both mutant lines displayed a compensatory overaccumulation of AtDeg8. The repression of AtDeg5 protease altered a range of phenotypic features in at least one of the mutants, with the most prominent being changes in chronological progression of development and growth of individual rosette leaves, flower production and silique ripening as well as in the area of fully expanded leaves and chloroplast ultrastructure. By analyzing the results of parallel-mutant screening we conclude that AtDeg8 overdose may rescue 23% of AtDeg5 deficiency with regard to some AtDeg5-controlled traits; alternatively AtDeg5 may have catalytic sites in excess so that these traits might remain unaltered when AtDeg5 pool is reduced by 23%. For some other AtDeg5-dependent traits the absence of excessive amount of AtDeg5 catalytic sites, lack of AtDeg5 dosage effect and inability of AtDeg8 to compensate deficiency or absence of AtDeg5 occurred

    Multimodal stimulus coding by a gustatory sensory neuron in Drosophila larvae.

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    Accurate perception of taste information is crucial for animal survival. In adult Drosophila, gustatory receptor neurons (GRNs) perceive chemical stimuli of one specific gustatory modality associated with a stereotyped behavioural response, such as aversion or attraction. We show that GRNs of Drosophila larvae employ a surprisingly different mode of gustatory information coding. Using a novel method for calcium imaging in the larval gustatory system, we identify a multimodal GRN that responds to chemicals of different taste modalities with opposing valence, such as sweet sucrose and bitter denatonium, reliant on different sensory receptors. This multimodal neuron is essential for bitter compound avoidance, and its artificial activation is sufficient to mediate aversion. However, the neuron is also essential for the integration of taste blends. Our findings support a model for taste coding in larvae, in which distinct receptor proteins mediate different responses within the same, multimodal GRN

    Developing Feasible and Effective School-Based Interventions for Children With ASD: A Case Study of the Iterative Development Process

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    Despite an emphasis on identifying evidence-based practices among researchers and using evidence-based practices among professionals in the field of education, there are still problems with uptake and implementation in real-world settings. This lack of diffusion of practices is evident in educational programming for children with autism spectrum disorder (ASD). One solution is to use an iterative process to develop interventions in which researchers work in collaboration with the end users to test and refine interventions. However, there are very few guidelines for developing feasible and effective interventions through these iterative processes. This article provides a description of the iterative process used to develop the Advancing Social-Communication and Play (ASAP) intervention, a supplemental program designed for public preschool classrooms serving students with ASD, and examples of how data from the sequence of iterative design studies shaped the intervention development. The research team offers guidelines for other researchers looking to engage in intervention development using an iterative process in the context of partnerships with end users, including suggestions for planning and executing an intervention development grant

    Communicative Gesture Use in Infants With and Without Autism: A Retrospective Home Video Study

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    Compare gesture use in infants with autism to infants with other developmental disabilities (DD) or typical development (TD)

    Children with autism deserve evidence-based intervention

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    The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Jennifer J Couper and Amanda J Sampso

    Contribution to the understanding of tribological properties of graphite intercalation compounds with metal chloride

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    Intrinsic tribological properties of lamellar compounds are usually attributed to the presence of van der Waals gaps in their structure through which interlayer interactions are weak. The controlled variation of the distances and interactions between graphene layers by intercalation of electrophilic species in graphite is used in order to explore more deeply the friction reduction properties of low-dimensional compounds. Three graphite intercalation compounds with antimony pentachloride, iron trichloride and aluminium trichloride are studied. Their tribological properties are correlated to their structural parameters, and the interlayer interactions are deduced from ab initio bands structure calculations

    The relationship between sensory sensitivity and autistic traits in the general population.

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    Individuals with Autism Spectrum Disorders (ASDs) tend to have sensory processing difficulties (Baranek et al. in J Child Psychol Psychiatry 47:591–601, 2006). These difficulties include over- and under-responsiveness to sensory stimuli, and problems modulating sensory input (Ben-Sasson et al. in J Autism Dev Disorders 39:1–11, 2009). As those with ASD exist at the extreme end of a continuum of autistic traits that is also evident in the general population, we investigated the link between ASD and sensory sensitivity in the general population by administering two questionnaires online to 212 adult participants. Results showed a highly significant positive correlation (r = .775, p < .001) between number of autistic traits and the frequency of sensory processing problems. These data suggest a strong link between sensory processing and autistic traits in the general population, which in turn potentially implicates sensory processing problems in social interaction difficulties
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