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Articles tagged: configuration files
Mascot security – guest users and administrators
Mascot Security is a role-based access system that allows administrators to control different aspects of privacy and priority access. It integrates with authentication systems like Microsoft Active Directory (AD) and various single sign-on systems. It can also be configured for a core lab, where search results can be shared with collaborators without them having access to the results of other groups. [...]
Get better HCD results by matching internal fragments
Mascot ships with several instrument definitions, which define the fragment ion series used for matching and scoring. All of them enable b ions and most enable y ions, and a few like ETD-TRAP also enable c and z+1. Mascot can also match internal fragments, which are formed by double backbone cleavage, a combination of a/b type and y type. Of [...]
Get more search speed with SplitNumberOfQueries
Mascot Server has several parameters and options that have an effect on database search duration. One of them is SplitNumberOfQueries, which specifies how many queries (MS/MS spectra) are searched at a time. The default is 1000 queries, which is reasonable, but like all defaults, it isn’t optimal. On most hardware, increasing it to 2000 will yield an immediate 10-20% performance [...]
NCBI nr tips
NCBI nr is the comprehensive database of non-identical protein sequences compiled by the National Center for Biotechnology Information. The database is available in Mascot Server as the NCBIprot predefined definition. If possible, nr should be used as the database of last resort due to its huge size. The January 2021 version contains 338 million protein sequences and the FASTA file [...]
Single sign-on (SSO) and Mascot
Mascot Server has a role-based security system called Mascot Security. Common use cases are restricting access to configuration files or specific sequence databases, or imposing limits on search size or duration for specific users or groups. These were discussed in earlier blog articles Mascot Security: priority settings and Mascot Security: privacy settings. Mascot Security isn’t designed to have super secure [...]
The minutiae of database management
The two major inputs into a database search are sequence databases and mass spectrometry data. Management of the databases in Mascot Server has evolved and improved over the years and newer versions. There are still a few issues that come up regularly and I am going to cover them in this article. Common error messages When you activate a new [...]
Disaster recovery
There are a number of potential issues that can cause your Mascot Server or other computer infrastructure to stop working. In the worst case, you may need to do a full recovery from backups. This can be an involved procedure, but it is straightforward as long as you have backed up key configuration and data files. For disk or storage [...]
Is your database search reproducible?
A lot has been written about the reproducibility of shotgun proteomics workflows, as well as controlling measurement variability between instruments and laboratories. An equally important factor is data analysis transparency and reproducibility, which is gaining increasing visibility. This boils down to two essentials: recording all software parameters used, and ensuring the software produces the same output given the same input [...]
Spring clean your mascot.dat
Updates to Mascot 2.5 will be going out shortly. When an existing installation is updated, settings in the options section of mascot.dat are only modified by the installer in exceptional cases. The assumption is that any changes have been made with good reason and should be honoured. The down-side of this approach is that values may be persisted that are [...]
Peak list arcana*
This article addresses some aspects of how the information in a peak list is used by Mascot, what is not used, and how the peak list is processed prior to a search. These things are all in the manual, but can be difficult to find, short of reading it from cover to cover. Fragment charge is not used in the [...]