1,333 research outputs found
Robotic assisted Laparoscopic partial Nephrectomy for suspected Renal Cell Carcinoma: Retrospective review of surgical outcomes of 35 Cases
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Effective Conformal Theory and the Flat-Space Limit of AdS
We develop the idea of an effective conformal theory describing the low-lying
spectrum of the dilatation operator in a CFT. Such an effective theory is
useful when the spectrum contains a hierarchy in the dimension of operators,
and a small parameter whose role is similar to that of 1/N in a large N gauge
theory. These criteria insure that there is a regime where the dilatation
operator is modified perturbatively. Global AdS is the natural framework for
perturbations of the dilatation operator respecting conformal invariance, much
as Minkowski space naturally describes Lorentz invariant perturbations of the
Hamiltonian. Assuming that the lowest-dimension single-trace operator is a
scalar, O, we consider the anomalous dimensions, gamma(n,l), of the
double-trace operators of the form O (del^2)^n (del)^l O. Purely from the CFT
we find that perturbative unitarity places a bound on these dimensions of
|gamma(n,l)|<4. Non-renormalizable AdS interactions lead to violations of the
bound at large values of n. We also consider the case that these interactions
are generated by integrating out a heavy scalar field in AdS. We show that the
presence of the heavy field "unitarizes" the growth in the anomalous
dimensions, and leads to a resonance-like behavior in gamma(n,l) when n is
close to the dimension of the CFT operator dual to the heavy field. Finally, we
demonstrate that bulk flat-space S-matrix elements can be extracted from the
large n behavior of the anomalous dimensions. This leads to a direct connection
between the spectrum of anomalous dimensions in d-dimensional CFTs and
flat-space S-matrix elements in d+1 dimensions. We comment on the emergence of
flat-space locality from the CFT perspective.Comment: 46 pages, 2 figures. v2: JHEP published versio
Predictors of failed attendances in a multi-specialty outpatient centre using electronic databases.
BACKGROUND: Failure to keep outpatient medical appointments results in inefficiencies and costs. The objective of this study is to show the factors in an existing electronic database that affect failed appointments and to develop a predictive probability model to increase the effectiveness of interventions. METHODS: A retrospective study was conducted on outpatient clinic attendances at Tan Tock Seng Hospital, Singapore from 2000 to 2004. 22864 patients were randomly sampled for analysis. The outcome measure was failed outpatient appointments according to each patient's latest appointment. RESULTS: Failures comprised of 21% of all appointments and 39% when using the patients' latest appointment. Using odds ratios from the mutliple logistic regression analysis, age group (0.75 to 0.84 for groups above 40 years compared to below 20 years), race (1.48 for Malays, 1.61 for Indians compared to Chinese), days from scheduling to appointment (2.38 for more than 21 days compared to less than 7 days), previous failed appointments (1.79 for more than 60% failures and 4.38 for no previous appointments, compared with less than 20% failures), provision of cell phone number (0.10 for providing numbers compared to otherwise) and distance from hospital (1.14 for more than 14 km compared to less than 6 km) were significantly associated with failed appointments. The predicted probability model's diagnostic accuracy to predict failures is more than 80%. CONCLUSION: A few key variables have shown to adequately account for and predict failed appointments using existing electronic databases. These can be used to develop integrative technological solutions in the outpatient clinic
Unnatural Origin of Fermion Masses for Technicolor
We explore the scenario in which the breaking of the electroweak symmetry is
due to the simultaneous presence and interplay of a dynamical sector and an
unnatural elementary Higgs. We introduce a low energy effective Lagrangian and
constrain the various couplings via direct search limits and electroweak and
flavor precision tests. We find that the model we study is a viable model of
dynamical breaking of the electroweak symmetry.Comment: 20 pages, 7 eps figure
Sialic acid changes in Dalton's lymphoma-bearing mice after cyclophosphamide and cisplatin treatment
A Prospective Nested Case-Control Study of Dengue in Infants: Rethinking and Refining the Antibody-Dependent Enhancement Dengue Hemorrhagic Fever Model
Analyses of a prospective case-control study of infant dengue by Daniel Libraty and colleagues casts doubt on the antibody-dependent enhancement model for dengue hemorrhagic fever
Information and Discriminability as Measures of Reliability of Sensory Coding
Response variability is a fundamental issue in neural coding because it limits all information processing. The reliability of neuronal coding is quantified by various approaches in different studies. In most cases it is largely unclear to what extent the conclusions depend on the applied reliability measure, making a comparison across studies almost impossible. We demonstrate that different reliability measures can lead to very different conclusions even if applied to the same set of data: in particular, we applied information theoretical measures (Shannon information capacity and Kullback-Leibler divergence) as well as a discrimination measure derived from signal-detection theory to the responses of blowfly photoreceptors which represent a well established model system for sensory information processing. We stimulated the photoreceptors with white noise modulated light intensity fluctuations of different contrasts. Surprisingly, the signal-detection approach leads to a safe discrimination of the photoreceptor response even when the response signal-to-noise ratio (SNR) is well below unity whereas Shannon information capacity and also Kullback-Leibler divergence indicate a very low performance. Applying different measures, can, therefore, lead to very different interpretations concerning the system's coding performance. As a consequence of the lower sensitivity compared to the signal-detection approach, the information theoretical measures overestimate internal noise sources and underestimate the importance of photon shot noise. We stress that none of the used measures and, most likely no other measure alone, allows for an unbiased estimation of a neuron's coding properties. Therefore the applied measure needs to be selected with respect to the scientific question and the analyzed neuron's functional context
Estimating Dengue Transmission Intensity from Case-Notification Data from Multiple Countries
Despite being the most widely distributed mosquito-borne viral infection, estimates of dengue transmission intensity and associated burden remain ambiguous. With advances in the development of novel control measures, obtaining robust estimates of average dengue transmission intensity is key for assessing the burden of disease and the likely impact of interventions.We estimated the force of infection (λ) and corresponding basic reproduction numbers (R0) by fitting catalytic models to age-stratified incidence data identified from the literature. We compared estimates derived from incidence and seroprevalence data and assessed the level of under-reporting of dengue disease. In addition, we estimated the relative contribution of primary to quaternary infections to the observed burden of dengue disease incidence. The majority of R0 estimates ranged from one to five and the force of infection estimates from incidence data were consistent with those previously estimated from seroprevalence data. The baseline reporting rate (or the probability of detecting a secondary infection) was generally low (<25%) and varied within and between countries.As expected, estimates varied widely across and within countries, highlighting the spatio-temporally heterogeneous nature of dengue transmission. Although seroprevalence data provide the maximum information, the incidence models presented in this paper provide a method for estimating dengue transmission intensity from age-stratified incidence data, which will be an important consideration in areas where seroprevalence data are not available
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