209 research outputs found
Crossâ Network Directory Service: Infrastructure to enable collaborations across distributed research networks
IntroductionExisting largeâ scale distributed health data networks are disconnected even as they address related questions of healthcare research and public policy. This paper describes the design and implementation of a fully functional prototype openâ source tool, the Crossâ Network Directory Service (CNDS), which addresses much of what keeps distributed networks disconnected from each other.MethodsThe set of services needed to implement a Crossâ Directory Service was identified through engagement with stakeholders and workgroup members. CNDS was implemented using PCORnet and Sentinel network instances and tested by participating data partners.ResultsWeb services that enable the four major functional features of the service (registration, discovery, communication, and governance) were developed and placed into an openâ source repository. The services include a robust metadata model that is extensible to accommodate a virtually unlimited inventory of metadata fields, without requiring any further software development. The user interfaces are programmatically generated based on the contents of the metadata model.ConclusionThe CNDS pilot project gathered functional requirements from stakeholders and collaborating partners to build a software application to enable crossâ network data and resource sharing. The two partnersâ one from Sentinel and one from PCORnetâ tested the software. They successfully entered metadata about their organizations and data sources and then used the Discovery and Communication functionality to find data sources of interest and send a crossâ network query. The CNDS software can help integrate disparate health data networks by providing a mechanism for data partners to participate in multiple networks, share resources, and seamlessly send queries across those networks.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149237/1/lrh210187.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149237/2/lrh210187_am.pd
Relativistic Calculation of the Meson Spectrum: a Fully Covariant Treatment Versus Standard Treatments
A large number of treatments of the meson spectrum have been tried that
consider mesons as quark - anti quark bound states. Recently, we used
relativistic quantum "constraint" mechanics to introduce a fully covariant
treatment defined by two coupled Dirac equations. For field-theoretic
interactions, this procedure functions as a "quantum mechanical transform of
Bethe-Salpeter equation". Here, we test its spectral fits against those
provided by an assortment of models: Wisconsin model, Iowa State model,
Brayshaw model, and the popular semi-relativistic treatment of Godfrey and
Isgur. We find that the fit provided by the two-body Dirac model for the entire
meson spectrum competes with the best fits to partial spectra provided by the
others and does so with the smallest number of interaction functions without
additional cutoff parameters necessary to make other approaches numerically
tractable. We discuss the distinguishing features of our model that may account
for the relative overall success of its fits. Note especially that in our
approach for QCD, the resulting pion mass and associated Goldstone behavior
depend sensitively on the preservation of relativistic couplings that are
crucial for its success when solved nonperturbatively for the analogous
two-body bound-states of QED.Comment: 75 pages, 6 figures, revised content
UML Reflections
The UML shares with reflective architectures the idea that self-definition of languages and systems is a key principle for building and maintaining complex systems. The UML is now defined by a four-layer metalevel structure, enabling a flexible and extensible definition of models by metamodels, and even a self-description of the meta-metamodel (the MOF). This metalevel dimension of UML is currently restricted to structural reflection. But recently a new extension to the UML, called the Action Semantics (AS), has been proposed for standardization to the OMG. This paper explores how this proposed extension brings a behavioural reflection dimension to the UML. Indeed, we show that it is not only possible but quite e#ective to use the AS for manipulating UML models (including the AS metamodel). Besides elegant conceptual achievements, such as a metacircular definition of the AS, reflective modeling with the AS leverages on the UML metalevel architecture to provide the benefits of a reflective approach, in terms of separation of concerns, within a mainstream industrial context. A complete model can now be built as an ideal model representing the core concepts in the application, to which non-functional requirements are integrated as fully traceable transformations over this ideal model. For example, this approach paves the way for powerful UML-defined semantics-based model transformations such as refactoring, aspect weaving, application of design patterns or round-trip engineering
Adipose triglyceride lipase (ATGL) expression in human skeletal muscle is type I (oxidative) fiber specific
Accumulation of triacylglycerol (TAG) and lipid intermediates in skeletal muscle plays an important role in the etiology of insulin resistance and type 2 diabetes mellitus. Disturbances in skeletal muscle lipid turnover and lipolysis may contribute significantly to this. So far, knowledge on the regulation of muscle lipolysis is limited. Recently the identification of a new lipase was reported: adipose triglyceride lipase (ATGL). ATGL deficient animals show significant lipid accumulation in skeletal muscle, which may indicate that ATGL plays a pivotal role in skeletal muscle lipolysis. However, until now, it is still unknown whether ATGL protein is expressed in human skeletal muscle. Therefore, the aim of the present study was to investigate whether ATGL is expressed at the protein level in human skeletal muscle, and to examine whether its expression is fiber-type specific. To accomplish this, we established an imunohistochemical and immunofluorescent staining procedure to study ATGL protein expression in relation to fiber type in human vastus lateralis muscle of eight male subjects (BMI range: 21.0â34.5Â kg/m2 and age: 38â59Â years). In the present paper we report for the first time that ATGL protein is indeed expressed in human skeletal muscle. Moreover, ATGL is exclusively expressed in type I (oxidative) muscle fibers, suggesting a pivotal role for ATGL in intramuscular fatty acid handling, lipid storage and breakdown
Rigorous QCD-Potential for the -System at Threshold
Recent evidence for the top mass in the region of 160 for the first
time provides an opportunity to use the full power of relativistic quantum
field theoretical methods, available also for weakly bound systems. Because of
the large decay width \G of the top quark individual energy-levels in
"toponium" will be unobservable. However, the potential for the
system, based on a systematic expansion in powers of the strong coupling
constant \a_s can be rigorously derived from QCD and plays a central role in
the threshold region. It is essential that the neglect of nonperturbative
(confining) effects is fully justified here for the first time to a large
accuracy, also just {\it because} of the large \G. The different
contributions to that potential are computed from real level corrections near
the bound state poles of the -system which for \G \ne 0 move into
the unphysical sheet of the complex energy plane. Thus, in order to obtain the
different contributions to that potential we may use the level corrections at
that (complex) pole. Within the relevant level shifts we especially emphasize
the corrections of order O(\a_s^4 m_t) and numerically comparable ones to
that order also from electroweak interactions which may become important as
well.Comment: 36 pages (mailer uncorrupted version), TUW-94-1
Neurobiology of social behavior abnormalities in autism and Williams syndrome
Social behavior is a basic behavior mediated by multiple brain regions and neural circuits, and is crucial for the survival and development of animals and humans. Two neuropsychiatric disorders that have prominent social behavior abnormalities are autism spectrum disorders (ASD), which is characterized mainly by hyposociability, and Williams syndrome (WS), whose subjects exhibit hypersociability. Here we review the unique properties of social behavior in ASD and WS, and discuss the major theories in social behavior in the context of these disorders. We conclude with a discussion of the research questions needing further exploration to enhance our understanding of social behavior abnormalities
Organizing risk: organization and management theory for the risk society
Risk has become a crucial part of organizing, affecting a wide range of organizations in all sectors. We identify, review and integrate diverse literatures relevant to organizing risk, building on an existing framework that describes how risk is organized in three âmodesâ â prospectively, in real-time, and retrospectively. We then identify three critical issues in the existing literature: its fragmented nature; its neglect of the tensions associated with each of the modes; and its tendency to assume that the meaning of an object in relation to risk is singular and stable. We provide a series of new insights with regard to each of these issues. First, we develop the concept of a risk cycle that shows how organizations engage with all three modes and transition between them over time. Second, we explain why the tensions have been largely ignored and show how studies using a risk work perspective can provide further insights into them. Third, we develop the concept of risk translation to highlight the ways in the meanings of risks can be transformed and to identify the political consequences of such translations. We conclude the paper with a research agenda to elaborate these insights and ideas further
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