10,776 research outputs found
NEPOTISM IN HONEY BEES, COMPUTER PROGRAMS AND SCIENTIFIC HYPOTHESES
Page et al. (1989) attempted to show that bees on queen cells preferentially reared their super sisters as replacement queens rather than half sisters. In support of their contention, they used computer simulation to model the biological system. We argue that the simulation did not accurately reflect the biological system in several important respects. We show that random data will produce the same kinds of statistical significance as the actual data
Gradient Flow Finite Element Discretizations with Energy-Based Adaptivity for the Gross-Pitaevskii Equation
We present an effective adaptive procedure for the numerical approximation of
the steady-state Gross-Pitaevskii equation. Our approach is solely based on
energy minimization, and consists of a combination of gradient flow iterations
and adaptive finite element mesh refinements. Numerical tests show that this
strategy is able to provide highly accurate results, with optimal convergence
rates with respect to the number of freedom
Perturbed cholesterol and vesicular trafficking associated with dengue blocking in Wolbachia-infected Aedes aegypti cells
Wolbachia are intracellular maternally inherited bacteria that can spread through insect populations and block virus transmission by mosquitoes, providing an important approach to dengue control. To better understand the mechanisms of virus inhibition, we here perform proteomic quantification of the effects of Wolbachia in Aedes aegypti mosquito cells and midgut. Perturbations are observed in vesicular trafficking, lipid metabolism and in the endoplasmic reticulum that could impact viral entry and replication. Wolbachia-infected cells display a differential cholesterol profile, including elevated levels of esterified cholesterol, that is consistent with perturbed intracellular cholesterol trafficking. Cyclodextrins have been shown to reverse lipid accumulation defects in cells with disrupted cholesterol homeostasis. Treatment of Wolbachia-infected Ae. aegypti cells with 2-hydroxypropyl-β-cyclodextrin restores dengue replication in Wolbachia-carrying cells, suggesting dengue is inhibited in Wolbachia-infected cells by localised cholesterol accumulation. These results demonstrate parallels between the cellular Wolbachia viral inhibition phenotype and lipid storage genetic disorders
Optimal simulation-based Bayesian decisions
We present a framework for the efficient computation of optimal Bayesian
decisions under intractable likelihoods, by learning a surrogate model for the
expected utility (or its distribution) as a function of the action and data
spaces. We leverage recent advances in simulation-based inference and Bayesian
optimization to develop active learning schemes to choose where in parameter
and action spaces to simulate. This allows us to learn the optimal action in as
few simulations as possible. The resulting framework is extremely simulation
efficient, typically requiring fewer model calls than the associated posterior
inference task alone, and a factor of more efficient than
Monte-Carlo based methods. Our framework opens up new capabilities for
performing Bayesian decision making, particularly in the previously challenging
regime where likelihoods are intractable, and simulations expensive.Comment: 12 pages, 4 figure
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