3,732 research outputs found
Biological control of taro scarab beetle (Papuanauninodis Coleoptera: Scarabaeidae) instars via Scoliid and Voria Tachinidae parasitoid wasps
Scoliid and Voria Tachinidae parasitoid wasps are shown to be able to control the population of the Taro Scarab beetle (Papuanauninodis, Coleoptera: Scarabaeidae) larvae using a newly created continuous-time simulation model based on non-linear ordinary differential equations that track the populations of the beetle’s life cycle stages: egg, larva, pupa, adult and the populations of the two parasitoid wasps. Due to the fact that the scarab beetles are, relatively speaking, long lived it is challenging to drive down the adult population below the environmental carrying capacity. Mortality and predator/prey capture rates are modelled using the Weibull and Pascal probability distribution functions, respectively. We suggest the use of a virus or fungi to drive down the population of the adult beetles, the ambition being to avoid the use of pesticides so as to produce higher quality food that doesn’t damage human health via chemical residues
Poisson statistics of PageRank probabilities of Twitter and Wikipedia networks
We use the methods of quantum chaos and Random Matrix Theory for analysis of
statistical fluctuations of PageRank probabilities in directed networks. In
this approach the effective energy levels are given by a logarithm of PageRank
probability at a given node. After the standard energy level unfolding
procedure we establish that the nearest spacing distribution of PageRank
probabilities is described by the Poisson law typical for integrable quantum
systems. Our studies are done for the Twitter network and three networks of
Wikipedia editions in English, French and German. We argue that due to absence
of level repulsion the PageRank order of nearby nodes can be easily
interchanged. The obtained Poisson law implies that the nearby PageRank
probabilities fluctuate as random independent variables.Comment: 4 pages, 4 figures http://www.quantware.ups-tlse.fr
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