6 research outputs found
Gauge Structure of Vacuum String Field Theory
We study the gauge structure of vacuum string field theory expanded around
the D-brane solution, namely, the gauge transformation and the transversality
condition of the massless vector fluctuation mode. We find that the gauge
transformation on massless vector field is induced as an anomaly; an infinity
multiplied by an infinitesimal factor. The infinity comes from the singularity
at the edge of the eigenvalue distribution of the Neumann matrix, while the
infinitesimal factor from the violation of the equation of motion of the
fluctuation modes due to the regularization for the infinity. However, the
transversality condition cannot be obtained even if we take into account the
anomaly contribution.Comment: 19 pages, LaTeX2
Correlation functions in a c=1 boundary conformal field theory
We obtain exact results for correlation functions of primary operators in the
two-dimensional conformal field theory of a scalar field interacting with a
critical periodic boundary potential. Amplitudes involving arbitrary bulk
discrete primary fields are given in terms of SU(2) rotation coefficients while
boundary amplitudes involving discrete boundary fields are independent of the
boundary interaction. Mixed amplitudes involving both bulk and boundary
discrete fields can also be obtained explicitly. Two- and three-point boundary
amplitudes involving fields at generic momentum are determined, up to
multiplicative constants, by the band spectrum in the open-string sector of the
theory.Comment: 33 pages, 6 figure
Higher Level Open String States from Vacuum String Field Theory
We construct massive open string states around a classical solution in the
oscillator formulation of Vacuum String Field Theory. In order for the correct
mass spectrum to be reproduced, the projection operators onto the modes of the
left- and right-half of the string must have an anomalous eigenvalue 1/2, and
the massive states are constructed using the corresponding eigenvector. We
analyze numerically the projection operators by regularizing them to finite
size matrices and confirm that they indeed have eigenvalue 1/2. Beside the
desired massive states, we have spurious massive as well as massless states,
which are infinitely degenerate. We show that these unwanted states can be
gauged away.Comment: 16 pages, no figures, LaTeX, v2:minor correction
Crypthophilic Acids A, B, And C: Resin Glycosides From Aerial Parts Of Scrophularia Crypthophila
The water-soluble part of the methanolic extract from the aerial parts of Scrophularia crypthophila, through chromatographic methods, yielded three new resin glycosides, crypthophilic acids A-C (1-3). Compounds 1-3 are tetraglycosides of (+)-3S,12S-dihydroxypalmitic acid. The structures of these and 10 known compounds were elucidated by spectroscopic and chemical means. All natural resin glycosides known so far have been obtained from Convolvulaceae plants; this is the first report of such glycosides from another, taxonomically unrelated family (Scrophulariaceae).Wo
Clinical Information Systems – Seen through the Ethics Lens
Objective: The more people there are who use clinical information systems (CIS) beyond their traditional intramural confines, the more promising the benefits are, and the more daunting the risks will be. This review thus explores the areas of ethical debates prompted by CIS conceptualized as smart systems reaching out to patients and citizens. Furthermore, it investigates the ethical competencies and education needed to use these systems appropriately.
Methods: A literature review covering ethics topics in combination with clinical and health information systems, clinical decision support, health information exchange, and various mobile devices and media was performed searching the MEDLINE database for articles from 2016 to 2019 with a focus on 2018 and 2019. A second search combined these keywords with education.
Results: By far, most of the discourses were dominated by privacy, confidentiality, and informed consent issues. Intertwined with confidentiality and clear boundaries, the provider-patient relationship has gained much attention. The opacity of algorithms and the lack of explicability of the results pose a further challenge. The necessity of sociotechnical ethics education was underpinned in many studies including advocating education for providers and patients alike. However, only a few publications expanded on ethical competencies. In the publications found, empirical research designs were employed to capture the stakeholders’ attitudes, but not to evaluate specific implementations.
Conclusion: Despite the broad discourses, ethical values have not yet found their firm place in empirically rigorous health technology evaluation studies. Similarly, sociotechnical ethics competencies obviously need detailed specifications. These two gaps set the stage for further research at the junction of clinical information systems and ethics