2,580 research outputs found
Cooperative Online Learning: Keeping your Neighbors Updated
We study an asynchronous online learning setting with a network of agents. At
each time step, some of the agents are activated, requested to make a
prediction, and pay the corresponding loss. The loss function is then revealed
to these agents and also to their neighbors in the network. Our results
characterize how much knowing the network structure affects the regret as a
function of the model of agent activations. When activations are stochastic,
the optimal regret (up to constant factors) is shown to be of order
, where is the horizon and is the independence
number of the network. We prove that the upper bound is achieved even when
agents have no information about the network structure. When activations are
adversarial the situation changes dramatically: if agents ignore the network
structure, a lower bound on the regret can be proven, showing that
learning is impossible. However, when agents can choose to ignore some of their
neighbors based on the knowledge of the network structure, we prove a
sublinear regret bound, where is the clique-covering number of the network
Comparison of parametric, orthogonal, and spline functions to model individual lactation curves for milk yield in Canadian Holsteins
Test day records for milk yield of 57,390 first lactation Canadian Holsteins were analyzed with a linear model that included the fixed effects of herd-test date and days in milk (DIM) interval nested within age and calving season.
Residuals from this model were analyzed as a new variable and fitted with a five parameter model, fourth-order Legendre polynomials, with linear, quadratic and cubic spline models with three knots. The fit of the models was
rather poor, with about 30%-40% of the curves showing an adjusted R-square lower than 0.20 across all models. Results underline a great difficulty in modelling individual deviations around the mean curve for milk yield. However, the Ali and Schaeffer (5 parameter) model and
the fourth-order Legendre polynomials were able to detect two basic shapes of individual deviations among the mean curve. Quadratic and, especially, cubic spline functions had better fitting performances but a poor predictive
ability due to their great flexibility that results
in an abrupt change of the estimated curve when data are missing. Parametric and orthogonal polynomials seem to be robust and affordable under this standpoint
Chromaticity dependence of the transverse effective impedance in the CERN Proton Synchrotron
The current knowledge of the transverse beam coupling impedance of the CERN Proton Synchrotron (PS) has been established with beam-based measurements at different energies. The transverse coherent tune shift as a function of the beam intensity has been measured in order to evaluate the total effective imaginary part of the transverse impedance in the accelerator at the energies of 7, 13 and 25 GeV. Measurements have been performed changing the vertical chromaticity
for each vertical tune scan with intensity. The data analysis revealed an increase of impedance with chromaticity for all the considered energies. The transverse impedance
can be compared with the previously evaluated theoretical impedance budget taking into account the individual contribution of several machine devices
Anomalous lack of decoherence of the Macroscopic Quantum Superpositions based on phase-covariant Quantum Cloning
We show that all Macroscopic Quantum Superpositions (MQS) based on
phase-covariant quantum cloning are characterized by an anomalous high
resilence to the de-coherence processes. The analysis supports the results of
recent MQS experiments and leads to conceive a useful conjecture regarding the
realization of complex decoherence - free structures for quantum information,
such as the quantum computer.Comment: 4 pages, 3 figure
Quantum Metric Unveils Defect Freezing in Non-Hermitian Systems
Non-Hermiticity in quantum Hamiltonians leads to nonunitary time evolution
and possibly complex energy eigenvalues, which can lead to a rich phenomenology
with no Hermitian counterpart. In this work, we study the dynamics of an
exactly solvable non-Hermitian system, hosting both -symmetric
and -broken modes subject to a linear quench. Employing a fully
consistent framework, in which the Hilbert space is endowed with a nontrivial
dynamical metric, we analyze the dynamics of the generated defects. In contrast
to Hermitian systems, our study reveals that PT -broken time evolution leads to
defect freezing and hence the violation of adiabaticity. This physics
necessitates the so-called metric framework, as it is missed by the oft used
approach of normalizing quantities by the time-dependent norm of the state. Our
results are relevant for a wide class of experimental systems.Comment: Main text: 7 pages and 3 figure
Faricimab for the Treatment of Diabetic Macular Edema and Neovascular Age-Related Macular Degeneration.
Nowadays; intravitreal anti-vascular endothelial growth factor (VEGF) drugs are considered the first-line therapeutic strategy for treating macular exudative diseases; including wet age-related macular degeneration (w-AMD) and diabetic macular edema (DME). Despite the important clinical achievements obtained by anti-VEGF drugs in the management of w-AMD and DME; some limits still remain; including high treatment burden; the presence of unsatisfactory results in a certain percentage of patients and long-term visual acuity decline due to complications such as macular atrophy and fibrosis. Targeting the angiopoietin/Tie (Ang/Tie) pathway beyond the VEGF pathway may be a possible therapeutic strategy; which may has the potential to solve some of the previous mentioned challenges. Faricimab is a new; bispecific antibody targeting both VEGF-A and the Ang-Tie/pathway. It was approved by FDA and; more recently; by EMA for treating w-AMD and DME. Results from phase III trials TENAYA and LUCERNE (w-AMD) and RHINE and YOSEMITE (DME) have shown the potential of faricimab to maintain clinical efficacy with more prolonged treatment regimens compared to aflibercept (12 or 16 weeks) with a a good safety profile
Fit of different functions to the individual deviations in random regression test day models for milk yield in dairy cattle
The shape of individual deviations of milk yield for dairy cattle from the fixed part of a random
regression test day model (RRTDM) was investigated. Data were 53,217 TD records for milk yield of 6,229 first lactation
Canadian Holsteins in Ontario. Data were fitted with a model that included the fixed effects of herd-testdate,
DIM interval nested within age and season of calving. Residuals of the model were then fitted with the following
functions: Ali and Schaeffer 5 parameter model, fourth-order Legendre Polynomials, and cubic spline with
three, four or five knots. Result confirm the great variability of shape that can be found when individual lactation
are modeled. Cubic splines gave better fitting pe4rformances although together with a marked tendency to yield
aberrant estimates at the edge of the lactation trajectory
Percutaneous radiofrequency ablation of HCC: reduced ablation duration and increased ablation size using single, internally cooled electrodes with an optimized pulsing algorithm
Purpose To assess the use of optimized radiofrequency (RF) to achieve larger, spherical ablation volumes with short application duration for hepatocellular carcinoma (HCC). Materials and methods Twenty-two patients (M:F = 17:5, median age 69.6 year, range 63–88) with 28 HCCs due to HCV + liver cirrhosis underwent RFA. 20/28 (71.4%) were tumors ≤3cm diameter, and 8/28 (28.6%) ranged from 3.2 to 4.2 cm. RF was applied using up to 2500mA via an optimized pulsing algorithm with real-time ultrasound monitoring to detect hyperechogenic changes. Single insertions of an internally cooled electrode were performed using exposed tips of 2 or 3 cm for 13 HCCs and 4 cm for 15 HCCs. All patients were followed-up for a minimum of 5 years with contrast-enhanced computed tomography (CECT). Results Technical success was achieved without adverse events in all cases. The mean ablation time was 8.5 ± 2.6 min. In 21/28 (75%), ablation duration ranged from 3 to 9 min, with 12 min duration applied in only 7/28 (25%). Mean coagulation diameters were 2.4 ± 0.14, 3.3 ± 0.62, and 4.4 ± 1.0, for 2, 3 and 4 cm electrodes, respectively (p 3 cm tumors developed local progression. One patient had multifocal disease with no local progression. Conclusion Efficient delivery of RF energy can considerably decrease the ablation time in many instances while achieving larger, relatively spherical, and reproducible areas of ablation with extremely low rates of local tumor progression and adverse events
Enabling protein-hosted organocatalytic transformations
In this review, the development of organocatalytic artificial enzymes will be discussed. This area of protein engineering research has underlying importance, as it enhances the biocompatibility of organocatalysis for applications in chemical and synthetic biology research whilst expanding the catalytic repertoire of enzymes. The approaches towards the preparation of organocatalytic artificial enzymes, techniques used to improve their performance (selectivity and reactivity) as well as examples of their applications are presented. Challenges and opportunities are also discussed
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