4,116 research outputs found
Quantum correlations in a cluster-like system
We discuss a cluster-like 1D system with triplet interaction. We study the
topological properties of this system. We find that the degeneracy depends on
the topology of the system, and well protected against external local
perturbations. All these facts show that the system is topologically ordered.
We also find a string order parameter to characterize the quantum phase
transition. Besides, we investigate two-site correlations including
entanglement, quantum discord and mutual information. We study the different
divergency behaviour of the correlations. The quantum correlation decays
exponentially in both topological and magnetic phases, and diverges in reversed
power law at the critical point. And we find that in TQPT systems, the global
difference of topology induced by dimension can be reflected in local quantum
correlations.Comment: 7 pages, 6 figure
A Study on the Design Thinking and Drawing of the Concept Development
This study was aim to examine the cognitive progress of graphic design involved in concept development. The results show that: (1) Cognitive progress can be observed from the design thinking and drawing patterns that emerge in designing works. The thinking activity was distinguished into general, experiential and evaluating thoughts, whereas drawing activity was categorized into graphic drawing and word description. (2) On the whole, more time was spent on general thought, less on experiential thought, and the least on evaluating thought. (3) There were three stages of concept development. General thought occurs more frequent in the initial stage while picture sketch takes place more frequent in the middle and final stages. In the other words, the process of the concept development was filled up via the concepts formed at first stage and translated into idea sketches at the next two stages
Factors affecting synonymous codon usage of housekeeping genes in Drosophila melanogaster
Housekeeping genes (HK genes) are required for cell survival and the maintenance of basic cellular functions. The investigation of factors affecting codon usage patterns in HK genes of insects can help in understanding the molecular evolution of insects and aid the development of insect pest management strategies. In this study, we employed bioinformatics approaches to analyze the codon usage bias (CUB) of HK genes in the insect model organism, Drosophila melanogaster. A comparison of CUB between 1107 HK genes and 1084 high tissue specificity genes suggested that HK genes have higher CUB in D. melanogaster. In addition, we found that CUB inversely correlates with the non-synonymous substitution rate of HK genes. Therefore, we attempted to identify the factors that potentially influence the codon usage pattern of HK genes. Our results suggest that mutation pressure and natural selection highly correlate with CUB in the HK genes of D. melanogaster and that two topological properties of HK proteins (proportion of protein interacting length and protein connectivity) also correlate with CUB in the HK genes of D. melanogaster. This study provides insight into CUB in the HK genes of D. melanogaster, and the results can support future investigations of potential applications in agricultural and biomedical field
Dimethyl 3,5-diethyl-1H-pyrrole-2,4-dicarboxylÂate
The title pyrrole derivative, C12H17NO4, consists of a pyrrole ring with two diagonally attached methÂoxyÂcarbonyl groups and two diagonally attached ethyl groups. The two carbonyl groups are approximately in the same plane as the pyrrole ring, making dihedral angles of 3.50 (19) and 6.70 (19)°. In the crystal, adjacent molÂecules are assembled into dimers in a head-to-head mode by pairs of interÂmolecular N—H⋯O hydrogen bonds
Survive the north: transplantation for conservation of mangrove forests requires consideration of influences of low temperature, mating system and their joint effects on effective size of the reforested populations
Mangrove forests, which occur in the intertidal regions of tropical and sub-tropical zones, have high ecological and economic values. They have rapidly reduced over the past decades due to various reasons. Reforestation is a common strategy for the conservation of mangroves, but information on the renewal capacity and viability of these artificial mangrove populations is still lacking. Here, we estimated the effective population size (NE) of an artificial population of Kandelia obovata (Rhizophoraceae) and explored the effects of intrinsic and extrinsic factors on changes in NE to evaluate population viability and develop appropriate management strategies for mangrove forests. This population consisted of three ecologically and genetically differentiated groups that had experienced a major low-temperature event during the winter of 2015–2016 and varied in cold resistance. We first detected population bottlenecks and estimated contemporary values of NE for different groups using microsatellite data. Next, we performed paternity analyses for seedlings and propagules to explore variations in the reproductive success of individuals within the three groups before and after the low-temperature event. Lastly, we simulated four scenarios to characterize the effects of low temperature, mating system, and variance in reproductive success on changes in NE in a hypothetical metapopulation based on empirical estimates. Our results show that groups with moderate or poor cold resistance experienced local bottlenecks, and shifts in effective breeders occurred following the low-temperature event, which indicates that low temperature has an effect on not only population size but also reproductive success. Furthermore, our simulations revealed that changes in NE are jointly affected by reproductive success, mating system, and environmental conditions. These findings enhance our understanding of the multiple factors that affect NE, and provide key information that will aid the reforestation and management of mangrove forests, especially when they are introduced to high-latitude areas
- …