Shuffled frog-leaping algorithm (SFLA) has long been considered as new evolutionary algorithm of group evolution, and has a high computing performance and excellent ability for global search. Knapsack problem is a typical NP-complete problem. For the discrete search space, this paper presents the improved SFLA (ISFLA), and solves the knapsack problem by using the algorithm. Experimental results...

Molecular breeding via DNA shuffling can direct the evolution of viruses with desired traits. By using a positive-strand RNA virus, porcine reproductive and respiratory syndrome virus (PRRSV), as a model, rapid attenuation of the virus was achieved in this study by DNA shuffling of the viral envelope genes from multiple strains. The GP5 envelope genes of 7 genetically divergent PRRSV strains an...

BACKGROUND AND PURPOSE Transcranial Doppler may be used to detect spontaneous cerebral emboli (SCE), but this information will only identify at-risk patients if these individuals are consistently identified over time. We investigated the consistency of SCE production in patients with symptomatic carotid disease. METHODS Transcranial Doppler signals from the ipsilateral middle cerebral artery ...

human language, over its evolutionary history, has emerged as one of the fundamental defining characteristic of the modern man. however, this milestone evolutionary process through natural selection has not left any ’linguistic fossils’ that may enable us to trace back the actual course of development of language and its establishment in human societies. lacking analytical tools to fathom the cr...

The first step in the dynamic modelling of pesticides is a reliable hydrodynamic model. SWAT (Soil and Water Assessment Tool) calculates both the dynamic hydrological response and the associated diffuse pesticide supply towards surface waters. In this study, we focus on the hydrodynamic part. First, an intensive data collection for the Nil-catchment was performed. During model set-up, a reducti...

The reaction of Re2(CO)10 with the 2-arylazopyridine ligand, L [L NC5H4–N N–C6H4(R), R H, o-Me/Cl, m-Me/Cl] in dry THF under a dinitrogen atmosphere afforded a metal–metal bonded product of the type (L)(CO)3Re –Re (CO)3(L) 1. On a silica gel column and in the presence of chlorinated solvents (CHCl3 or CH2Cl2) the complex 1 transformed into a mononuclear complex of composition Re(L)(CO)3Cl 2, wh...

Sister chromatid exchange (SCE) can occur by several recombination mechanisms, including those directly initiated by double-strand breaks (DSBs), such as gap repair and break-induced replication (BIR), and those initiated when DNA polymerases stall, such as template switching. To elucidate SCE recombination mechanisms, we determined whether spontaneous and DNA damage-associated SCE requires spe...

Polycomb group (PcG) proteins repress homeotic genes and other developmental regulatory genes in cells where these genes must remain inactive during development. In Drosophila and in vertebrates, PcG proteins exist in two distinct multiprotein complexes, the Esc/Eed-E(z) complex and PRC1. Drosophila PRC1 contains Polycomb, Posterior sexcombs and Polyhomeotic, the products of three PcG genes tha...