Spinning Charged Solutions in 2+1 Dimensional Einstein-Maxwell-Dilaton Gravity

We report a new class of rotating charged solutions in 2+1 dimensions. These solutions are obtained for Einstein-Maxwell gravity coupled to a dilaton field with selfdual electromagnetic fields. The mass and the angular momentum of these solutions computed at spatial infinity are finite. The class of solutions considered here have naked singularities and are asymptotically flat.Comment: 10 pages, LaTe

A protocol for custom CRISPR Cas9 donor vector construction to truncate genes in mammalian cells using pcDNA3 backbone

Background Clustered regularly interspaced short palindromic repeat (CRISPR) RNA-guided adaptive immune systems are found in prokaryotes to defend cells from foreign DNA. CRISPR Cas9 systems have been modified and employed as genome editing tools in wide ranging organisms. Here, we provide a detailed protocol to truncate genes in mammalian cells using CRISPR Cas9 editing. We describe custom donor vector construction using Gibson assembly with the commonly utilized pcDNA3 vector as the backbone. Results We describe a step-by-step method to truncate genes of interest in mammalian cell lines using custom-made donor vectors. Our method employs 2 guide RNAs, mutant Cas9D10A nickase (Cas9 = CRISPR associated sequence 9), and a custom-made donor vector for homologous recombination to precisely truncate a gene of interest with a selectable neomycin resistance cassette (NPTII: Neomycin Phosphotransferase II). We provide a detailed protocol on how to design and construct a custom donor vector using Gibson assembly (and the commonly utilized pcDNA3 vector as the backbone) allowing researchers to obtain specific gene modifications of interest (gene truncation, gene deletion, epitope tagging or knock-in mutation). Selection of mutants in mammalian cell lines with G418 (Geneticin) combined with several screening methods: western blot analysis, polymerase chain reaction, and Sanger sequencing resulted in streamlined mutant isolation. Proof of principle experiments were done in several mammalian cell lines. Conclusions Here we describe a detailed protocol to employ CRISPR Cas9 genome editing to truncate genes of interest using the commonly employed expression vector pcDNA3 as the backbone for the donor vector. Providing a detailed protocol for custom donor vector design and construction will enable researchers to develop unique genome editing tools. To date, detailed protocols for CRISPR Cas9 custom donor vector construction are limited (Lee et al. in Sci Rep 5:8572, 2015; Ma et al. in Sci Rep 4:4489, 2014). Custom donor vectors are commercially available, but can be expensive. Our goal is to share this protocol to aid researchers in performing genetic investigations that require custom donor vectors for specialized applications (specific gene truncations, knock-in mutations, and epitope tagging applications)

ESTELL: A Quasi-Toroidally Symmetric Stellarator

International audienceThis work presents the physics design for a simple quasi-axially symmetric stellarator. A plasma configuration described by a modest number of Fourier coefficients was found to establish this symmetry with good accuracy. The low rotational transform results in a relatively simple coil set exhibiting low curvatures and comfortable clearance between adjacent coils. As another consequence, the maximum achievable plasma pressure will be limited to about 0.5%. An experiment along the lines proposed would allow an exploration of the confinement properties of a quasi-axially symmetric configuration