10,631 research outputs found

    How to Use Sigstore without Sigstore

    Get PDF
    Sigstore is a Linux Foundation project aiming to become the new standard for signing software artifacts. It consists of a free certificate authority called Fulcio, a tamper-resistant public log called Rekor, and an optional federated OIDC identity provider called Dex, where Rekor also acts as the timestamping service. Several command line interfaces (CLIs), written in different languages, are available to interact with it for signing software artifacts. Ironically, we will show in this paper the design of Sigstore eliminates the need of Sigstore, i.e., the key components mentioned above are inessential. Specifically, we will first show how to remove the dependency on Fulcio from existing CLIs while keeping the CLIs work. Next, we will show how to remove the dependency on Rekor from the CLIs. Last, we will explain why relying on Dex, an optional black box with too much power, should be avoided. As none of Fulcio, Rekor, and Dex is essential to making existing CLIs work, we conclude that they are unnecessary trusted third parties which the open source community should avoid employing. Instead, existing CLIs can be easily adapted to remove the dependency on them while providing the same functionality and user experience. The design of Sigstore is an example of solving a problem with a method which requires the solution as the input

    cis-Tetra­aqua­bis­{5-[4-(1H-imidazol-1-yl-κN 3)phen­yl]tetra­zolido}manganese(II) dihydrate

    Get PDF
    In the title compound, [Mn(C10H7N6)2(H2O)4]·2H2O, the complex unit comprises an Mn2+ ion, coordinated by two imidazole N atoms from cis-related monodentate 5-[4-(imidazol-1-yl)phen­yl]tetra­zolide ligands and four water mol­ecules, together with two water mol­ecules of solvation. The Mn2+ ion lies on a twofold rotation axis and has a slightly distorted octa­hedral geometry. The mol­ecules are connected by O—H⋯N and O—H⋯O hydrogen bonds involving both coordinated and solvent water mol­ecules, generating a three-dimensional structure. Two C atoms of the imidazole ring of the ligand are each disordered over two sites with occupancy factors of 0.75 and 0.25

    Efficient nitrogen-vacancy centers' fluorescence excitation and collection from micrometer-sized diamond by a tapered optical fiber

    Full text link
    Efficiently excite nitrogen-vacancy (NV) centers in diamond and collect their fluorescence significantly benefit the fiber-optic-based NV sensors. Here, using a tapered optical fiber (TOF) tip, we significantly improve the efficiency of the laser excitation and fluorescence collection of the NV, thus enhance the sensitivity of the fiber-optic based micron-sized diamond magnetic sensor. Numerical calculation shows that the TOF tip delivers a high numerical aperture (NA) and has a high fluorescence excitation and collection efficiency. Experiments demonstrate that using such TOF tip can obtain up to over 7-fold the fluorescence excitation efficiency and over15-fold the fluorescence collection efficiency of a flat-ended (non-TOF) fiber. Such fluorescence collection enhances the sensitivity of the optical fiber-based diamond NV magnetometer, thus extending its potential application region.Comment: 11 pages, 13 figure

    VNTRDB: a bacterial variable number tandem repeat locus database

    Get PDF
    Variable number tandem repeat-PCR (VNTR-PCR) is a novel method developed for molecular typing of microorganisms. This method has proven useful in epidemiological studies in medical microbiology. Although hundreds of bacterial genomes have been sequenced, variable number tandem repeats (TRs) derived from comparative genome analyses are scarce. This may hamper their application to the surveillance of bacteria in molecular epidemiology. Here, we present a freely accessible variable number tandem repeat database (VNTRDB) that is intended to be a resource for helping in the discovery of putatively polymorphic tandem repeat loci and to aid with assay design by providing the flanking sequences that can be used in subsequent PCR primer design. In order to reveal possible polymorphism, each TR locus was obtained by comparing the sequences between different sets of bacterial genera, species or strains. Through this comparison, TRs which are unique to a genus can also be identified. Moreover, a visualization tool is provided to ensure that the copy number and locus length of repeats are correct. The VNTRDB is available at
    • …
    corecore