60 research outputs found
A Microscopic Derivation of the SO(5)-Symmetric Landau-Ginzburg Potential
We construct a microscopic model of electron interactions which gives rise to
both superconductivity and antiferromagnetism, and which admits an approximate
SO(5) symmetry that relates these two phases. The symmetry can be exact, or it
may exist only in the long-wavelength limit, depending on the detailed form of
the interactions. We compute the macroscopic Landau-Ginzburg free energy for
this model as a function of temperature and doping, by explicitly integrating
out the fermions. We find that the resulting phase diagram can resemble that
observed for the cuprates, with the antiferromagnetism realized as a spin
density wave, whose wavelength might be incommensurate with the lattice spacing
away from half filling.Comment: 29 pp., plain TeX, 7 figures, uses macros.tex (included) and
epsf.tex; added subject clas
Incidentalomas during imaging for primary hyperparathyroidismâincidence and clinical outcomes
Background: Imaging for pre-operative localisation of parathyroid glands in primary hyperparathyroidism is now
routine. This has led to the detection of incidental lesions (incidentalomas) in other organs, the nature of which is
not well characterised.
The aim of this study was to determine the incidence, characteristics and outcomes in patients who had incidental
findings on parathyroid imaging.
Methods: Records of patients who underwent imaging for primary hyperparathyroidism over 2 years were reviewed
to identify incidental lesions detected on parathyroid imaging. Patients with persistent or renal hyperparathyroidism
were excluded. Details on the management of detected incidentalomas were obtained from patient records.
Results: Incidentalomas were identified in 17 of 170 patients (10 %) undergoing parathyroid imaging. Incidentalomas
included thyroid (n = 11), breast (n = 3), lateral compartment of the neck (n = 1), lung (n = 1) and clavicle (n = 1). However,
no disease of clinical significance needing treatment was detected on further investigation.
Conclusions: Although a significant proportion of patients undergoing parathyroid imaging had incidental lesions
detected, these seem to be of little clinical significance. The morbidity and cost of further interventions on these
incidentalomas need to be weighed against the benefits of routine imaging in improving outcomes of first-time
surgery in patients with primary hyperparathyroidism.
Keywords: Parathyroid gland, Primary hyperparathyroidism, Imaging, Incidentaloma
Environmental sensing and response genes in cnidaria : the chemical defensome in the sea anemone Nematostella vectensis
Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Cell Biology and Toxicology 24 (2008): 483-502, doi:10.1007/s10565-008-9107-5.The starlet sea anemone Nematostella vectensis has been recently established as a
new model system for the study of the evolution of developmental processes, as cnidaria
occupy a key evolutionary position at the base of the bilateria. Cnidaria play important
roles in estuarine and reef communities, but are exposed to many environmental stressors.
Here I describe the genetic components of a âchemical defensomeâ in the genome of
N. vectensis, and review cnidarian molecular toxicology. Gene families that defend
against chemical stressors and the transcription factors that regulate these genes have
been termed a âchemical defensome,â and include the cytochromes P450 and other
oxidases, various conjugating enyzymes, the ATP-dependent efflux transporters,
oxidative detoxification proteins, as well as various transcription factors. These genes
account for about 1% (266/27200) of the predicted genes in the sea anemone genome,
similar to the proportion observed in tunicates and humans, but lower than that observed
in sea urchins. While there are comparable numbers of stress-response genes, the stress
sensor genes appear to be reduced in N. vectensis relative to many model protostomes
and deuterostomes. Cnidarian toxicology is understudied, especially given the important
ecological roles of many cnidarian species. New genomic resources should stimulate the
study of chemical stress sensing and response mechanisms in cnidaria, and allow us to
further illuminate the evolution of chemical defense gene networks.WHOI Ocean Life Institute and NIH R01-ES01591
Decentralized Algorithm for Randomized Task Allocation in Fog Computing Systems
Fog computing is identified as a key enablerfor using various emerging applications by battery poweredand computationally constrained devices. In this paper, weconsider devices that aim at improving their performanceby choosing to offload their computational tasks to nearbydevices or to a cloud server. We develop a game theoreticalmodel of the problem, and we use variational inequalitytheory to compute an equilibrium task allocation in staticmixed strategies. Based on the computed equilibrium strategy,we develop a decentralized algorithm for allocating thecomputational tasks among nearby devices and the cloudserver. We use extensive simulations to provide insight intothe performance of the proposed algorithm, and we compareits performance with the performance of a myopic bestresponse algorithm that requires global knowledge of thesystem state. Despite the fact that the proposed algorithmrelies on average system parameters only, our results showthat it provides good system performance close to that of themyopic best response algorithm.QC 20180518</p
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