787 research outputs found

    Fluctuations in Chemical Gelation

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    We study a chemical gelation model in two dimensions which includes both monomer aggregations and bond fluctuations. Our numerical simulation shows that a sol-gel transition occurs when an initial monomer concentration is above a critical concentration. Fractal aggregates grow until the sol-gel transition occurs. After the gelation, however, bond fluctuations break the fractal structure and a novel inhomogeneous gel fibre network appears instead. A pore size distribution of the inhomogeneous structure shows the existence of hierarchical structures in the gel phase. It is also found that slow dynamics appear near the critical concentration.Comment: 6 pages, 10figure

    Structure and Thermodynamics of the Mixed Alkali Alanates

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    The thermodynamics and structural properties of the hexahydride alanates (M2M'AlH6) with the elpasolite structure have been investigated. A series of mixed alkali alanates (Na2LiAlH6, K2LiAlH6 and K2NaAlH6) were synthesized and found to reversibly absorb and desorb hydrogen without the need for a catalyst. Pressure-composition isotherms were measured to investigate the thermodynamics of the absorption and desorption reactions with hydrogen. Isotherms for catalyzed (4 mol% TiCl3) and uncatalyzed Na2LiAlH6 exhibited an increase in kinetics, but no change in the bulk thermodynamics with the addition of a dopant. A structural analysis using synchrotron x-ray diffraction showed that these compounds favor the Fm-3m space group with the smaller ion (M') occupying an octahedral site. These results demonstrate that appropriate cation substitutions can be used to stabilize or destabilize the material and may provide an avenue to improving the unfavorable thermodynamics of a number of materials with promising gravimetric hydrogen densities.Comment: 6 pages, 7 figures,3 tables, submitted to PR

    ISML: an interface specification meta-language

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    In this paper we present an abstract metaphor model situated within a model-based user interface framework. The inclusion of metaphors in graphical user interfaces is a well established, but mostly craft-based strategy to design. A substantial body of notations and tools can be found within the model-based user interface design literature, however an explicit treatment of metaphor and its mappings to other design views has yet to be addressed. We introduce the Interface Specification Meta-Language (ISML) framework and demonstrate its use in comparing the semantic and syntactic features of an interactive system. Challenges facing this research are outlined and further work proposed

    Infant motor behaviour and functional and cognitive outcome at school-age:A follow-up study in very high-risk children

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    BACKGROUND: The Infant Motor Profile (IMP) is an appropriate tool to assess and monitor infant motor behaviour over time. Infants at very high risk (VHR) due to a lesion of the brain generally show impaired motor development. They may grow into or out of their neurodevelopmental deficit. AIMS: Evaluate associations between IMP-trajectories, summarised by IMP-scores in early infancy and rates of change, and functional and cognitive outcome at school-age in VHR-children. STUDY DESIGN: Longitudinal study. SUBJECTS: 31 VHR-children, mainly due to a brain lesion, who had multiple IMP-assessments during infancy, were re-assessed at 7-10 years (school-age). OUTCOME MEASURES: Functional outcome was assessed with the Vineland-II, cognition with RAKIT 2. Associations between IMP-trajectories and outcome were tested by multivariable linear regression analyses. RESULTS: When corrected for sex, maternal education and follow-up age, initial scores of total IMP, variation and performance domains, as well as their rates of change were associated with better functional outcome (unstandardised coefficients [95% CI]): 36.44 [19.60-53.28], 33.46 [17.43-49.49], 16.52 [7.58-25.46], and 513.15 [262.51-763.79], 356.70 [148.24-565.15], and 269 [130.57-407.43], respectively. Positive rates of change in variation scores were associated with better cognition at school-age: 34.81 [16.58-53.03]. CONCLUSION: Our study indicated that in VHR-children IMP-trajectories were associated with functional outcome at school-age, and to a minor extent also with cognition. Initial IMP-scores presumably reflect the effect of an early brain lesion on brain functioning, whereas IMP rate of change reflects whether infants are able to grow into or out of their initial neurodevelopmental deficit

    Perception of Nuclear Energy and Coal in France and the Netherlands

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    This study focuses on the perception of large scale application of nuclear energy and coal in the Netherlands and France. The application of these energy-sources and the risks and benefits are judged differently by various group in society. In Europe, France has the highest density of nuclear power plants and the Netherlands has one of the lowest. In both countries scientists and social scientists completed a questionnaire assessing the perception of the large scale application of both energy sources. Furthermore, a number of variables relating to the socio cultural and political circumstances were measured. The results indicate that the French had a higher risk perception and a more negative attitude toward nuclear power than the Dutch. But they also assess the benefits of the use of nuclear power to be higher. Explanations for these differences are discussed

    Role of eisosomes in the necrotrophic fungus Alternaria brassicicola

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    lternaria brassicicola is a fungal necrotroph responsible for the Brassicaceae dark spot disease. This fungus is a seed-borne pathogen that only affects the aerial parts of host plants causing great damages with major incidence on yield and product quality. Its transmission to seed is a major component of pathogen fitness promoting the dispersal and long-term survival of the fungus. Recently, we showed that several eisosomal protein encoding genes were overexpressed when germinated spores of A.brassicicola were exposed to osmotic and hydric stresses, which are the main constraints encountered by the fungus during the seed colonization process. MCC/eisosomes are membrane microdomains whose function is still unclear. They have been proposed to participate in the plasma membrane function by regulating the homeostasis of lipids and would promote the recruitment of specific proteins and their subsequent protection from endocytosis. Here, we deciphered the potential involvement of eisosome in pathogenicity using a reverse genetic approach by generating and characterizing mutants deficient for key eisosomal proteinencoding genes (?pil1, ?nce102, ?lsp1 and ?pil1?lsp1). In parallel, these proteins have been fused to GFP to monitor their cellular location during the plant infection and following the exposure to stresses. Depending on the mutants, the leaf and silique colonization processes were impaired by comparison to the wild-type. We also showed a strong impact of MCC/eisosome proteinmutations on the generation of appressoria-like structures

    Development of muscle tone impairments in high-risk infants:Associations with cerebral palsy and cystic periventricular leukomalacia

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    AIM: To assess the prevalence and development of muscle tone impairments in infants at high risk of developmental disorders, and their associations with cerebral palsy (CP) and cystic periventricular leukomalacia (cPVL). METHOD: Longitudinal exploration of muscle tone in 39 infants at high risk of CP (LEARN2MOVE 0-2 project) mostly due to an early lesion of the brain. Muscle tone was assessed ā‰„4 times between 0 and 21 months corrected age (CA) with the Touwen Infant Neurological Examination. Diagnosis of CP was determined at 21 months CA. Neonatal neuro-imaging was available. Developmental trajectories were calculated using generalized linear mixed effect models. RESULTS: Infants showed atypical muscle tone in three or four body parts in 93% (172/185) of the assessments. The most prevalent muscle tone pattern was hypotonia of neck and trunk with hypertonia of the limbs (28%). From 7 months CA onwards hypertonia of the arms was associated with CP. Asymmetric arm tone during infancy was associated with unilateral CP. At 18-21 months CA ankle hypertonia was associated with CP at 21 months; leg hypertonia in infancy was not associated with CP. Leg hypertonia was associated with cPVL, regardless of age. INTERPRETATION: High-risk infants due to an early lesion of the brain often present with muscle tone impairment. In these infants, hypertonia and asymmetric muscle tone of the arms were from 7 months onwards associated with the diagnosis of CP at 21 months; hypertonia of the legs was not

    Phase Diagram of the 1D Anderson Lattice

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    We map out the phase diagram of the one--dimensional Anderson lattice by studying the ground state magnetization as a function of band--filling using the density matrix renormalization group technique. For strong coupling, we find that the quarter--filled system has an S=0 ground state with strong antiferromagnetic correlations. As additional electrons are put in, we find first a ferromagnetic phase, as reported by M\"{o}ller and W\"{o}lfle, and then a phase in which the ground state has total spin S=0S=0. Within this S=0S=0 phase, we find RKKY oscillations in the spin--spin correlation functions.Comment: REVTEX manuscript with 5 Postcript figures included in uu file. Submitted to Phys. Rev.

    LEARN2MOVE 0-2 years, a randomized early intervention trial for infants at very high risk of cerebral palsy:neuromotor, cognitive, and behavioral outcome

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    Contains fulltext : 229748.pdf (Publisherā€™s version ) (Open Access)Purpose: Evidence for efficacy of early intervention in infants at high risk of cerebral palsy (CP) is limited. We compared outcome of infants at very high risk of CP after receiving the family centered program COPing with and CAring for infants with special needs (COPCA) or typical infant physiotherapy.Materials and methods: Forty-three infants were randomly assigned before the corrected age of 9ā€‰months to 1 year of COPCA (nā€‰=ā€‰23) or typical infant physiotherapy (nā€‰=ā€‰20). Neuromotor development, cognition, and behavior was assessed until 21ā€‰months corrected age. Video-recorded physiotherapy sessions were quantitatively analyzed for further process analyses. Outcome was evaluated with nonparametric tests and linear mixed effect models.Results: During and after the interventions, infant outcome in both intervention groups was similar [primary outcome Infant Motor Profile: COPCA 82 (69-94), typical infant physiotherapy 81 (69-89); Hodges Lehman estimate of the difference 0 (confidence interval -5;4)]. Outcome was not associated with contents of intervention.Conclusions: One year of COPCA and 1Ā year of typical infant physiotherapy in infants at high risk of CP resulted in similar neurodevelopmental outcomes. It is conceivable that combinations of active ingredients from different approaches are needed for effective early intervention.IMPLICATIONS FOR REHABILITATIONFor infants at very high risk of cerebral palsy, 1Ā year of intervention with the family-centred programme Coping with and Caring for infants with special needs resulted in similar infant outcome as 1 year of typical infant physiotherapy.Infant's neuromotor, cognitive, and behavioural outcome was not associated with specific interventional elements, implying that the various elements may have a similar effect on developmental outcome.We suggest that a specific mix of ingredients of different approaches may work best, resulting in comprehensive care including both infant and family needs
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