209 research outputs found
ConfidentCare: A Clinical Decision Support System for Personalized Breast Cancer Screening
Breast cancer screening policies attempt to achieve timely diagnosis by the
regular screening of apparently healthy women. Various clinical decisions are
needed to manage the screening process; those include: selecting the screening
tests for a woman to take, interpreting the test outcomes, and deciding whether
or not a woman should be referred to a diagnostic test. Such decisions are
currently guided by clinical practice guidelines (CPGs), which represent a
one-size-fits-all approach that are designed to work well on average for a
population, without guaranteeing that it will work well uniformly over that
population. Since the risks and benefits of screening are functions of each
patients features, personalized screening policies that are tailored to the
features of individuals are needed in order to ensure that the right tests are
recommended to the right woman. In order to address this issue, we present
ConfidentCare: a computer-aided clinical decision support system that learns a
personalized screening policy from the electronic health record (EHR) data.
ConfidentCare operates by recognizing clusters of similar patients, and
learning the best screening policy to adopt for each cluster. A cluster of
patients is a set of patients with similar features (e.g. age, breast density,
family history, etc.), and the screening policy is a set of guidelines on what
actions to recommend for a woman given her features and screening test scores.
ConfidentCare algorithm ensures that the policy adopted for every cluster of
patients satisfies a predefined accuracy requirement with a high level of
confidence. We show that our algorithm outperforms the current CPGs in terms of
cost-efficiency and false positive rates
Boundary Effective Field Theory and Trans-Planckian Perturbations: Astrophysical Implications
We contrast two approaches to calculating trans-Planckian corrections to the
inflationary perturbation spectrum: the New Physics Hypersurface [NPH] model,
in which modes are normalized when their physical wavelength first exceeds a
critical value, and the Boundary Effective Field Theory [BEFT] approach, where
the initial conditions for all modes are set at the same time, and modified by
higher dimensional operators enumerated via an effective field theory
calculation. We show that these two approaches -- as currently implemented --
lead to radically different expectations for the trans-Planckian corrections to
the CMB and emphasize that in the BEFT formalism we expect the perturbation
spectrum to be dominated by quantum gravity corrections for all scales shorter
than some critical value. Conversely, in the NPH case the quantum effects only
dominate the longest modes that are typically much larger than the present
horizon size. Furthermore, the onset of the breakdown in the standard
inflationary perturbation calculation predicted by the BEFT formalism is likely
to be associated with a feature in the perturbation spectrum, and we discuss
the observational signatures of this feature in both CMB and large scale
structure observations. Finally, we discuss possible modifications to both
calculational frameworks that would resolve the contradictions identified here.Comment: Reworded commentary, reference added (v2) References added (v3
Contextual learning for unit commitment with renewable energy sources
In this paper, we study a unit commitment (UC) problem minimizing operating costs of the power system with renewable energy sources. We develop a contextual learning algorithm for UC (CLUC) which learns which UC schedule to choose based on the context information such as past load demand and weather condition. CLUC does not require any prior knowledge on the uncertainties such as the load demand and the renewable power outputs, and learns them over time using the context information. We characterize the performance of CLUC analytically, and prove its optimality in terms of the long-term average cost. Through the simulation results, we show the performance of CLUC and the effectiveness of utilizing the context information in the UC problem. © 2016 IEEE
Residential mobility and local housing-market differences
The authors extend previous literature on variations in mobility rates across local housing markets by examining the linkage of mobility rates at the household level to the structure of local housing markets. The results suggest that residential mobility rates differ widely across local housing markets, substantiating the view that residential relocation is intimately intertwined with conditions at the local level. Local housing-market conditions also have different effects on mobility rates for renters and owner-occupiers. The results suggest that variation in residential mobility rates across housing markets can be in part explained by level of urbanization, the tenure structure, the degree of government intervention, and the size of the housing market. Remarkably, these differences in local housing markets cannot be seen to be related to housing-market features only. The results suggest that these differences can also be attributed to the behavior or attitude of households with respect to housing
An M-theory solution generating technique and SL(2,R)
In this paper we generalize the O(p+1,p+1) solution generating technique
(this is a method used to deform Dp-branes by turning on a NS-NS B-field) to
M-theory, in order to be able to deform M5-brane supergravity solutions
directly in eleven dimensions, by turning on a non zero three form A. We find
that deforming the M5-brane, in some cases, corresponds to performing certain
SL(2,R) transformations of the Kahler structure parameter for the three-torus,
on which the M5-brane has been compactified. We show that this new M-theory
solution generating technique can be reduced to the O(p+1,p+1) solution
generating technique with p=4. Further, we find that it implies that the open
membrane metric and generalized noncommutativity parameter are manifestly
deformation independent for electric and light-like deformations. We also
generalize the O(p+1,p+1) method to the type IIA/B NS5-brane in order to be
able to deform NS5-branes with RR three and two forms, respectively. In the
type IIA case we use the newly obtained solution generating technique and
deformation independence to derive a covariant expression for an open D2-brane
coupling, relevant for OD2-theory.Comment: 24 pages, Latex. v2:Sections 3.2 and 3.3 improved. v3:Some
clarifications added. Version published in JHE
Mathematical modeling of plus-strand RNA virus replication to identify broad-spectrum antiviral treatment strategies
Plus-strand RNA viruses are the largest group of viruses. Many are human pathogens that inflict a socio-economic burden. Interestingly, plus-strand RNA viruses share remarkable similarities in their replication. A hallmark of plus-strand RNA viruses is the remodeling of intracellular membranes to establish replication organelles (so-called “replication factories”), which provide a protected environment for the replicase complex, consisting of the viral genome and proteins necessary for viral RNA synthesis. In the current study, we investigate pan-viral similarities and virus-specific differences in the life cycle of this highly relevant group of viruses. We first measured the kinetics of viral RNA, viral protein, and infectious virus particle production of hepatitis C virus (HCV), dengue virus (DENV), and coxsackievirus B3 (CVB3) in the immuno-compromised Huh7 cell line and thus without perturbations by an intrinsic immune response. Based on these measurements, we developed a detailed mathematical model of the replication of HCV, DENV, and CVB3 and showed that only small virus-specific changes in the model were necessary to describe the in vitro dynamics of the different viruses. Our model correctly predicted virus-specific mechanisms such as host cell translation shut off and different kinetics of replication organelles. Further, our model suggests that the ability to suppress or shut down host cell mRNA translation may be a key factor for in vitro replication efficiency, which may determine acute self-limited or chronic infection. We further analyzed potential broad-spectrum antiviral treatment options in silico and found that targeting viral RNA translation, such as polyprotein cleavage and viral RNA synthesis, may be the most promising drug targets for all plus-strand RNA viruses. Moreover, we found that targeting only the formation of replicase complexes did not stop the in vitro viral replication early in infection, while inhibiting intracellular trafficking processes may even lead to amplified viral growth. Molecular basis of virus replication, viral pathogenesis and antiviral strategie
Decoupling in an expanding universe: boundary RG-flow affects initial conditions for inflation
We study decoupling in FRW spacetimes, emphasizing a Lagrangian description
throughout. To account for the vacuum choice ambiguity in cosmological
settings, we introduce an arbitrary boundary action representing the initial
conditions. RG flow in these spacetimes naturally affects the boundary
interactions. As a consequence the boundary conditions are sensitive to
high-energy physics through irrelevant terms in the boundary action. Using
scalar field theory as an example, we derive the leading dimension four
irrelevant boundary operators. We discuss how the known vacuum choices, e.g.
the Bunch-Davies vacuum, appear in the Lagrangian description and square with
decoupling. For all choices of boundary conditions encoded by relevant boundary
operators, of which the known ones are a subset, backreaction is under control.
All, moreover, will generically feel the influence of high-energy physics
through irrelevant (dimension four) boundary corrections. Having established a
coherent effective field theory framework including the vacuum choice
ambiguity, we derive an explicit expression for the power spectrum of
inflationary density perturbations including the leading high energy
corrections. In accordance with the dimensionality of the leading irrelevant
operators, the effect of high energy physics is linearly proportional to the
Hubble radius H and the scale of new physics L= 1/M.Comment: LaTeX plus axodraw figures. v2: minor corrections; refs added. JHEP
style: 34 pages + 18 pages appendi
On isovector meson exchange currents in the Bethe-Salpeter approach
We investigate the nonrelativistic reduction of the Bethe-Salpeter amplitude
for the deuteron electrodisintegration near threshold energies. To this end,
two assumptions have been used in the calculations: 1) the static approximation
and 2) the one iteration approximation. Within these assumptions it is possible
to recover the nonrelativistic result including a systematic extension to
relativistic corrections. We find that the so-called pair current term can be
constructed from the -wave contribution of the deuteron Bethe-Salpeter
amplitude. The form factor that enters into the calculation of the pair current
is constrained by the manifestly gauge independent matrix elements.Comment: 15 pages, incl. 3 figures, to be published Phys. Rev.
Covariant description of inelastic electron--deuteron scattering:predictions of the relativistic impulse approximation
Using the covariant spectator theory and the transversity formalism, the
unpolarized, coincidence cross section for deuteron electrodisintegration,
, is studied. The relativistic kinematics are reviewed, and simple
theoretical formulae for the relativistic impulse approximation (RIA) are
derived and discussed. Numerical predictions for the scattering in the high
region obtained from the RIA and five other approximations are presented
and compared. We conclude that measurements of the unpolarized coincidence
cross section and the asymmetry , to an accuracy that will distinguish
between different theoretical models, is feasible over most of the wide
kinematic range accessible at Jefferson Lab.Comment: 54 pages and 24 figure
Artificial intelligence and machine learning algorithms for early detection of skin cancer in community and primary care settings : a systematic review
Acknowledgments This systematic review was funded by the National Institute for Health Research Policy Research Programme, conducted through the Policy Research Unit in Cancer Awareness, Screening, and Early Diagnosis (PR-PRU-1217–21601). The views expressed in this publication are those of the authors and not necessarily those of the National Health Service, the NIHR or the Department of Health and Social Care. The first author (OTJ) was also supported by the CanTest Collaborative funded by Cancer Research UK (C8640/A23385), of which FMW is Director, JE is an Associate Director, and NC is Research Fellow. During protocol development, this Review benefited from the advice of an international expert panel from the CanTest collaborative, including Willie Hamilton (University of Exeter, Exeter, UK), Greg Rubin (University of Newcastle, Newcastle, UK), Hardeep Singh (Baylor College of Medicine, Houston, TX, USA), and Niek de Wit (University Medical Center Utrecht, Utrecht, Netherlands). The research was also supported by a Cancer Research UK Cambridge Centre Clinical Research Fellowship for OTJ, and a National Health and Medical Research Council Investigator Fellowship (APP1195302) for JE. The funding sources had no role in the study design, data collection, data analysis, data interpretation, writing of the report, or in the decision to submit for publication. The authors would like to thank Isla Kuhn (Reader Services Librarian, University of Cambridge Medical Library, Cambridge, UK) for her help in developing the search strategy. We also thank Smiji Saji, who assisted with the early stages of the Review, Haruyuki Yanaoka, who assisted with the translation and assessment of papers that were written in Korean, and Steve Morris who assisted with the analysis of the data.Peer reviewedPublisher PD
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