5,611 research outputs found
Preheating in Bubble Collisions
In a landscape with metastable minima, the bubbles will inevitably nucleate.
We show that during the bubbles collide, due to the dramatically oscillating of
the field at the collision region, the energy deposited in the bubble walls can
be efficiently released by the explosive production of the particles. In this
sense, the collision of bubbles is actually highly inelastic. The cosmological
implications of this result are discussed.Comment: 5 pages, 4 figs, discussion improved, refs. added, and Fig.3 revised,
to publish in PR
From the social learning theory to a social learning algorithm for global optimization
Traditionally, the Evolutionary Computation (EC) paradigm is inspired by Darwinian evolution or the swarm intelligence of animals. Bandura's Social Learning Theory pointed out that the social learning behavior of humans indicates a high level of intelligence in nature. We found that such intelligence of human society can be implemented by numerical computing and be utilized in computational algorithms for solving optimization problems. In this paper, we design a novel and generic optimization approach that mimics the social learning process of humans. Emulating the observational learning and reinforcement behaviors, a virtual society deployed in the algorithm seeks the strongest behavioral patterns with the best outcome. This corresponds to searching for the best solution in solving optimization problems. Experimental studies in this paper showed the appealing search behavior of this human intelligence-inspired approach, which can reach the global optimum even in ill conditions. The effectiveness and high efficiency of the proposed algorithm has further been verified by comparing to some representative EC algorithms and variants on a set of benchmarks
On echo intervals in gravitational wave echo analysis
Gravitational wave echoes, if they exist, could encode important information
of new physics from the strong gravity regime. Current echo searches usually
assume constant interval echoes (CIEs) a priori, although unequal interval
echoes (UIEs) are also possible. Despite of its simplicity, the using of CIE
templates need to be properly justified, especially given the high sensitivity
of future gravitational wave detectors. In this paper, we assess the necessity
of UIE templates in echo searches. By reconstructing injected UIE signals with
both CIE and UIE templates, we show that the CIE template may significantly
misinterpret the echo signals if the variation of the interval is greater than
the statistical errors of the interval, which is further confirmed by a
Bayesian analysis on model stelection. We also forecast the constraints on the
echo intervals given by future GW detectors such as Advanced LIGO and Einstein
Telescope.Comment: 7 pages,6 figures and 3 table
Reduced glutamine synthetase activity alters the fecundity of female Bactrocera dorsalis (Hendel)
Glutamine synthetase (GS) is a key enzyme in glutamine synthesis and is associated with multiple physiological processes in insects, such as embryonic development, heat shock response, and fecundity regulation. However, little is known about the influence of GS on female fecundity in the oriental fruit fly, Bactrocera dorsalis. Based on the cloning of BdGSs, mitochondrial BdGSm and cytoplasmic BdGSc, we determined their expressions in the tissues of adult B. dorsalis. BdGSm was highly expressed in the fat body, while BdGSc was highly expressed in the head and midgut. Gene silencing by RNA interference against two BdGSs isoforms suppressed target gene expression at the transcriptional level, leading to a reduced ovarian size and lower egg production. The specific inhibitor L-methionine S-sulfoximine suppressed enzyme activity, but only the gene expression of BdGSm was suppressed. A similar phenotype of delayed ovarian development occurred in the inhibitor bioassay. Significantly lower expression of vitellogenin and vitellogenin receptor was observed when GS enzyme activity was suppressed. These data illustrate the effects of two GS genes on adult fecundity by regulating vitellogenin synthesis in different ways
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