611 research outputs found
Containerless preparation of advanced optical glasses: Experiment 77F095
Containerless processing of optical glasses was studied in preparation for space shuttle MEA flight experiments. Ground based investigation, experiment/hardware coordination activities and development of flight experiment and sample characterization plans were investigated. In the ground based investigation over 100 candidate glass materials for space processing were screened and promising compositions were identified. The system of Nb2O5-TiO2-CaO was found to be very rich with containerless glass compositions and as extensive number of the oxides combinations were tried resulting in a glass formation ternary phase diagram. The frequent occurrence of glass formation by containerless processing among the compositions for which no glass formations were previously reported indicated the possibility and an advantage of containerless processing in a terrestrial environment
A reference architecture for multi-level SLA management
There is a global trend towards service-orientation, both for organizing business interactions but also in modern IT architectures. At the business-level, service industries are becoming the dominating sector in which solutions are flexibly composed out of networked services. At the IT level, the paradigms of Service-Oriented Architecture and Cloud Computing realize service-orientation for both software and infrastructure services. Again, flexible composition across different layers is a major advantage of this paradigm. Service Level Agreements (SLA) are a common approach for specifying the exact conditions under which services are to be delivered and, thus, are a prerequisite for supporting the flexible trading of services. However, typical SLAs are just specified at a single layer and do not allow service providers to manage their service stack accordingly. They have no insight on how SLAs at one layer translate to metrics or parameters at the various lower layers of the service stack.
In this paper, we present a reference architecture for a multi-level SLA management framework. We discuss the fundamental concepts and detail the main architectural components and interfaces. Furthermore, we show how the framework can be flexibly used for different industrial scenarios
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Social anxiety in adult males with autism spectrum disorders
Background: Psychiatric conditions, notably anxiety, commonly co-occur with autism spectrum disorders (ASD). Method: This study investigated self-reported behavioural, cognitive and affective symptoms of social anxiety (SA) in 50 adult males with ASD. Associations between SA, core ASD symptoms and facets of neuropsychological functioning were also examined. Results: Twenty-six participants (52%) endorsed levels of SA that exceeded the suggested caseness threshold for social anxiety disorder. Categorical and dimensional data analyses indicated that there were no relationships between SA symptoms, present-state or childhood ASD symptom-severity, or measures of socio-emotional processing in this sample. Conclusions: Study findings suggest that severity of SA is not merely a reflection of ASD symptom-severity. Further research is needed to ascertain the prevalence of SA in adult ASD epidemiological samples, and identify causal and maintaining mechanisms for these co-morbid symptoms
Spatial interactions in agent-based modeling
Agent Based Modeling (ABM) has become a widespread approach to model complex
interactions. In this chapter after briefly summarizing some features of ABM
the different approaches in modeling spatial interactions are discussed.
It is stressed that agents can interact either indirectly through a shared
environment and/or directly with each other. In such an approach, higher-order
variables such as commodity prices, population dynamics or even institutions,
are not exogenously specified but instead are seen as the results of
interactions. It is highlighted in the chapter that the understanding of
patterns emerging from such spatial interaction between agents is a key problem
as much as their description through analytical or simulation means.
The chapter reviews different approaches for modeling agents' behavior,
taking into account either explicit spatial (lattice based) structures or
networks. Some emphasis is placed on recent ABM as applied to the description
of the dynamics of the geographical distribution of economic activities, - out
of equilibrium. The Eurace@Unibi Model, an agent-based macroeconomic model with
spatial structure, is used to illustrate the potential of such an approach for
spatial policy analysis.Comment: 26 pages, 5 figures, 105 references; a chapter prepared for the book
"Complexity and Geographical Economics - Topics and Tools", P. Commendatore,
S.S. Kayam and I. Kubin, Eds. (Springer, in press, 2014
Simple mindreading abilities predict complex theory of mind: developmental delay in autism spectrum disorders
Theory of Mind (ToM) is impaired in individuals with Autism Spectrum Disorders (ASD). The aims of this study were to: i) examine the developmental trajectories of ToM abilities in two different mentalizing tasks in children with ASD compared to TD children; and ii) to assess if a ToM simple test known as Eyes-test could predict performance on the more advanced ToM task, i.e. Comic Strip test. Based on a sample of 37 children with ASD and 55 TD children, our results revealed slower development at varying rates in all ToM measures in children with ASD, with delayed onset compared to TD children. These results could stimulate new treatments for social abilities, which would lessen the social deficit in ASD
Methylomic analysis of monozygotic twins discordant for autism spectrum disorder and related behavioural traits
Autism spectrum disorder (ASD) defines a group of common, complex neurodevelopmental disorders. Although the aetiology of ASD has a strong genetic component, there is considerable monozygotic (MZ) twin discordance indicating a role for non-genetic factors. Because MZ twins share an identical DNA sequence, disease-discordant MZ twin pairs provide an ideal model for examining the contribution of environmentally driven epigenetic factors in disease. We performed a genome-wide analysis of DNA methylation in a sample of 50 MZ twin pairs (100 individuals) sampled from a representative population cohort that included twins discordant and concordant for ASD, ASD-associated traits and no autistic phenotype. Within-twin and between-group analyses identified numerous differentially methylated regions associated with ASD. In addition, we report significant correlations between DNA methylation and quantitatively measured autistic trait scores across our sample cohort. This study represents the first systematic epigenomic analyses of MZ twins discordant for ASD and implicates a role for altered DNA methylation in autism
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