6,372 research outputs found
Cluster decomposition, T-duality, and gerby CFT's
In this paper we study CFT's associated to gerbes. These theories suffer from
a lack of cluster decomposition, but this problem can be resolved: the CFT's
are the same as CFT's for disconnected targets. Such theories also lack cluster
decomposition, but in that form, the lack is manifestly not very problematic.
In particular, we shall see that this matching of CFT's, this duality between
noneffective gaugings and sigma models on disconnected targets, is a worldsheet
duality related to T-duality. We perform a wide variety of tests of this claim,
ranging from checking partition functions at arbitrary genus to D-branes to
mirror symmetry. We also discuss a number of applications of these results,
including predictions for quantum cohomology and Gromov-Witten theory and
additional physical understanding of the geometric Langlands program.Comment: 61 pages, LaTeX; v2,3: typos fixed; v4: writing improved in several
sections; v5: typos fixe
Chromospheric Inversions of a Micro-flaring Region
We use spectropolarimetric observations of the Ca II 8542~\AA\ line, taken
from the Swedish 1-m Solar Telescope (SST), in an attempt to recover dynamic
activity in a micro-flaring region near a sunspot via inversions. These
inversions show localized mean temperature enhancements of 1000~K in the
chromosphere and upper photosphere, along with co-spatial bi-directional
Doppler shifting of 5 - 10 km s. This heating also extends along a
nearby chromospheric fibril, co-spatial to 10 - 15 km s down-flows.
Strong magnetic flux cancellation is also apparent in one of the footpoints,
concentrated in the chromosphere. This event more closely resembles that of an
Ellerman Bomb (EB), though placed slightly higher in the atmosphere than is
typically observed.Comment: 9 pages, 9 figures, accepted in ApJ. Movies are stored here:
https://star.pst.qub.ac.uk/webdav/public/areid/Microflare
Measurement of miniband parameters of a doped superlattice by photoluminescence in high magnetic fields
We have studied a 50/50\AA superlattice of GaAs/AlGaAs
composition, modulation-doped with Si, to produce
cm electrons per superlattice period. The modulation-doping was tailored
to avoid the formation of Tamm states, and photoluminescence due to interband
transitions from extended superlattice states was detected. By studying the
effects of a quantizing magnetic field on the superlattice photoluminescence,
the miniband energy width, the reduced effective mass of the electron-hole
pair, and the band gap renormalization could be deduced.Comment: minor typing errors (minus sign in eq. (5)
Characterization of microbial population of “Alheira” (a traditional Portuguese fermented sausage) by PCR-DGGE and traditional cultural microbiological methods
This study evaluates the microbial ecology of ‘Alheira’ by traditional
microbiological analysis and a PCR-denaturing gradient gel electrophoresis
(DGGE) protocol.
Methods and Results: Total microbial DNA from ‘Alheiras’ was extracted
directly from the products and subjected to PCR using Eubacterial primers for
16S rDNA. The amplicons were separated by DGGE. The results demonstrated
that different products of the same batch display identical profiles, whereas
products from different batches of the same producer could display different
DGGE profiles. ‘Alheiras’ from different producers were distinguishable based
on the respective DGGE profiles. The obtained sequences from prevalent
phylotypes affiliated with order Lactobacillales and order Bacillales and class
Gammaproteobacteria. The same samples were subjected to traditional microbiological
analysis. In both methods, lactic acid bacteria were dominant and were
present together with other organisms, mainly members of the family Micrococcaceae.
Conclusions: The approach explored in this study allowed the description of
the microbial community present in ‘Alheira’ in particular the diversity of lactic
acid bacteria.
Significance and Impact of the Study: This can be useful for the microbiological
characterization of traditional products in order to develop new methods of
quality control capable of supporting a standardization of the processes, while
preserving their typical traits
"Very urgent" kidney transplantation: results from one center.
Transplant Proc. 2003 May;35(3):1066.
"Very urgent" kidney transplantation: results from one center.
Costa S, Ventura A, Costa T, Martins L, Henriques A, Sarmento A.
Nephrology Department, Hospital de Santo António, 4050 Porto, Portugal.
PMID: 12947858 [PubMed - indexed for MEDLINE
DeepCare: A Deep Dynamic Memory Model for Predictive Medicine
Personalized predictive medicine necessitates the modeling of patient illness
and care processes, which inherently have long-term temporal dependencies.
Healthcare observations, recorded in electronic medical records, are episodic
and irregular in time. We introduce DeepCare, an end-to-end deep dynamic neural
network that reads medical records, stores previous illness history, infers
current illness states and predicts future medical outcomes. At the data level,
DeepCare represents care episodes as vectors in space, models patient health
state trajectories through explicit memory of historical records. Built on Long
Short-Term Memory (LSTM), DeepCare introduces time parameterizations to handle
irregular timed events by moderating the forgetting and consolidation of memory
cells. DeepCare also incorporates medical interventions that change the course
of illness and shape future medical risk. Moving up to the health state level,
historical and present health states are then aggregated through multiscale
temporal pooling, before passing through a neural network that estimates future
outcomes. We demonstrate the efficacy of DeepCare for disease progression
modeling, intervention recommendation, and future risk prediction. On two
important cohorts with heavy social and economic burden -- diabetes and mental
health -- the results show improved modeling and risk prediction accuracy.Comment: Accepted at JBI under the new name: "Predicting healthcare
trajectories from medical records: A deep learning approach
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