Healthy or Not: A Way to Predict Ecosystem Health in GitHub

With the development of open source community, through the interaction of developers, the collaborative development of software, and the sharing of software tools, the formation of open source software ecosystem has matured. Natural ecosystems provide ecological services on which human beings depend. Maintaining a healthy natural ecosystem is a necessity for the sustainable development of mankind. Similarly, maintaining a healthy ecosystem of open source software is also a prerequisite for the sustainable development of open source communities, such as GitHub. This paper takes GitHub as an example to analyze the health condition of open source ecosystem and, also, it is a research area in Symmetry. Firstly, the paper presents the healthy definition of GitHub open source ecosystem health and, then, according to the main components of natural ecosystem health, the paper proposes the health indicators and health indicators evaluation method. Based on the above, the GitHub ecosystem health prediction method is proposed. By analyzing the projects and data collected in GitHub, it is found that, using the proposed evaluation indicators and method, we can analyze the healthy development trend of the GitHub ecosystem and contribute to the stability of ecosystem development

RNA interference technology's research progress in the treatment of retinal disease

RNA interference exists widely in animals, which can induce specific genetic sequence to silence by double-stranded RNA molecules at the mRNA level. As a kind of new methods of blocking gene expression, RNA interference technology has become increasingly mature and perfect, it has opened up a new approach of gene therapy. RNA interference can effectively prevent the formation of new vessels in retina, restrain the occurrence and development of the proliferative vitreous retinopathy, and induce apoptosis of retinoblastoma cells. The research progress of the RNA interference in the above retinopathy was summarized in this review

Observation of Landau level-like quantizations at 77 K along a strained-induced graphene ridge

Recent studies show that the electronic structures of graphene can be modified by strain and it was predicted that strain in graphene can induce peaks in the local density of states (LDOS) mimicking Landau levels (LLs) generated in the presence of a large magnetic field. Here we report scanning tunnelling spectroscopy (STS) observation of nine strain-induced peaks in LDOS at 77 K along a graphene ridge created when the graphene layer was cleaved from a sample of highly oriented pyrolytic graphite (HOPG). The energies of these peaks follow the progression of LLs of massless 'Dirac fermions' (DFs) in a magnetic field of 230 T. The results presented here suggest a possible route to realize zero-field quantum Hall-like effects at 77 K

[2,9-Bis(3,5-dimethyl-1H-pyrazol-1-yl-κN 2)-1,10-phenanthroline-κ2 N,N′]bis­(thio­cyanato-κN)cadmium(II)

In the title complex, [Cd(NCS)2(C22H20N6)], the CdII ion is in a CdN6 coordination geometry which is inter­mediate between octa­hedral and trigonal–prismatic. The dihedral angles formed between the mean planes of the pyrazole rings and the phenanthroline system are 15.74 (15) and 16.30 (13)°. In the crystal, there is a π–π stacking inter­action involving two symmetry-related pyrazole rings, with a centroid–centroid distance of 3.664 (3) Å. In addition, there is a relatively short inter­molecular contact between C atoms [C⋯C = 3.399 (6) Å] involving symmetry-related pyridine rings along the a axis

Quantum Transports in Two-Dimensions with Long Range Hopping: Shielding, Localization and the Extended Isolated State

We investigate the effects of disorder and shielding on quantum transports in a two dimensional system with all-to-all long range hopping. In the weak disorder, cooperative shielding manifests itself as perfect conducting channels identical to those of the short range model, as if the long range hopping does not exist. With increasing disorder, the average and fluctuation of conductance are larger than those in the short range model, since the shielding is effectively broken and therefore long range hopping starts to take effect. Over several orders of disorder strength (until $\sim 10^4$ times of nearest hopping), although the wavefunctions are not fully extended, they are also robustly prevented from being completely localized into a single site. Each wavefunction has several localization centers around the whole sample, thus leading to a fractal dimension remarkably smaller than 2 and also remarkably larger than 0, exhibiting a hybrid feature of localization and delocalization. The size scaling shows that for sufficiently large size and disorder strength, the conductance tends to saturate to a fixed value with the scaling function $\beta\sim 0$, which is also a marginal phase between the typical metal ($\beta>0$) and insulating phase ($\beta<0$). The all-to-all coupling expels one isolated but extended state far out of the band, whose transport is extremely robust against disorder due to absence of backscattering. The bond current picture of this isolated state shows a quantum version of short circuit through long hopping.Comment: 15 pages, 8 figure