Light depolarization based on dispersion degree of polarization.

The dispersion degree of polarization, a new definition of the depolarization degree of partially polarized beams, is first proposed, to the best of our knowledge, to measure the performance of fiber depolarizers. First, the description of the polarization based on the Poincaré sphere is introduced. Then, the modified Delaunay triangulation algorithm is introduced, and the calculation formula of the dispersion degree of polarization is given based on this algorithm. The experimental device was set up, and the dispersion degree of polarization of the depolarized light after the fiber depolarizer was measured to be 47.3%. The components and proportions of polarization in the depolarized light were also obtained. Compared with the degree of polarization, the dispersion degree of polarization can quantitatively analyze the light polarization evaluation in the time dimension and provide a numerical reference for improving the depolarizer, thus increasing the fiber sensor's accuracy.

Culture shapes spontaneous brain dynamics - Shared versus idiosyncratic neural features among Chinese versus Canadian subjects.

Environmental factors, such as culture, are known to shape individual variation in brain activity including spontaneous activity, but less is known about their population-level effects. Eastern and Western cultures differ strongly in their cultural norms about relationships between individuals. For example, the collectivism, interdependence and tightness of Eastern cultures relative to the individualism, independence and looseness of Western cultures, promote interpersonal connectedness and coordination. Do such cultural contexts therefore influence the group-level variability of their cultural members' spontaneous brain activity? Using novel methods adapted from studies of inter-subject neural synchrony, we compare the group-level variability of resting state EEG dynamics in Chinese and Canadian samples. We observe that Chinese subjects show significantly higher inter-subject correlation and lower inter-subject distance in their EEG power spectra than Canadian subjects, as well as lower variability in theta power and alpha peak frequency. We demonstrate, for the first time, different relationships among subjects' resting state brain dynamics in Chinese and Canadian samples. These results point to more idiosyncratic neural dynamics among Canadian participants, compared with more shared neural features in Chinese participants.

Comparative analysis of codon usage patterns in chloroplast genomes of five Miscanthus species and related species.

Miscanthus is not only a perennial fiber biomass crop, but also valuable breeding resource for its low-nutrient requirements, photosynthetic efficiency and strong adaptability to environment. In the present study, the codon usage patterns of five different Miscanthus plants and other two related species were systematically analyzed. The results indicated that the cp genomes of the seven representative species were preference to A/T bases and A/T-ending codons. In addition, 21 common high-frequency codons and 4-11 optimal codons were detected in the seven chloroplast genomes. The results of ENc-plot, PR2-plot and neutrality analysis revealed the codon usage patterns of the seven chloroplast genomes are influenced by multiple factors, in which nature selection is the main influencing factor. Comparative analysis of the codon usage frequencies between the seven representative species and four model organisms suggested that Arabidopsis thaliana, Populus trichocarpa and Saccharomyces cerevisiae could be considered as preferential appropriate exogenous expression receptors. These results might not only provide important reference information for evolutionary analysis, but also shed light on the way to improve the expression efficiency of exogenous gene in transgenic research based on codon optimization.

A mixed ploidy natural population of Amorphophallus muelleri provides an opportunity to trace the evolution of Amorphophallus karyotype.

Amorphophallus, a perennial herb belongs to the family Araceae, and is widely distributed in Asia and Africa. As an agricultural crop, it has been cultivated and consumed for ~2000 years in China. Previous studies have found that there are chromosome number and ploidy changes in this genus, but there are a few reports on the evolution of different karyotypes. For this study, we collected 37 samples of a wild population of Amorphophallus muelleri from Myanmar and analysed their karyotypes. The karyotype analysis showed that it is a population with mixed chromosome numbers and ploidy, with four karyotypes of 2n = 24, 26, 28 and 39. Combining the results of this study with previous literature, we speculate that karyotypes with 2n = 26 may be the common ancestor, and further the other three karyotypes were evolved from this by various ways. As far as we know, this is the first attempt to put forward the hypothesis of the evolution of those four karyotypes together. On the other hand, by using inter-simple sequence repeat marker-based unweighted pair group method with arithmetic mean cluster analysis, we found that these individuals of four karyotypes can be divided into four corresponding categories, indicating that they have been differentiated at the genome, providing a theoretical basis for future use of these wild germplasm resources.