A Non-linearity Correction Method for Fast Digital Multi-Channel Analyzers

AbstractFast digital multi-channel analyzers (FDMCA) which based on flash ADCs have been intensively used recently. The FDMCA is different from traditional MCAs which based on Wilkinson ADCs. The non-linearity, including the integral non-linearity (INL) and differential non-linearity (DNL), mainly arising from flash ADCs, degrade the accuracy of fast digital MCAs. To improve the non-linearity of FDMCA, a practical off-line correction method has been proposed in this paper. The non-linearity features of the FDMCA system is obtained by a special measurement previously. In light of that the non-linearity of a system is inherent; the non-linearity can be eliminated by comparing the data between the general measurement and the special one

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

CAT Computer Aided Design for Technical Systems - ein Werkzeug im Verbundvorhaben PROSYT CAT-Abschlussbericht

Within the framework of the project documented here, a portable program system including design and system tools was developed, which can be implemented for small applications on high-performance personal computers (performance classes CADMUS 9000, INTEL 86/300 or similar) and for major applications on a terminal or workstation network, supported by a data processing center, if required. The core of this system is represented by a tool frame system consisting of a powerful interactive system (text + graphics), a retrieval system, a universal data keeping system and the Project Advisor. In most cases existing tools will be ''hooked'' into this tool frame. In exceptional cases non-available tools were developed or existing tools were extended in a way desired by users. (orig./RHM)Im Rahmen des dokumentierten Vorhabens wurde ein portables Programmsystem, mit Entwurfs- und Systemproduktionswerkzeugen entwickelt, das fuer kleine Anwendungen auf leistungsfaehigen Personal-Computern (Leistungsklassen CADMUS 9000, INTEL 86/300 o.ae.), fuer grosse Anwendungen auf einem gegebenenfalls durch ein Rechenzentrum gestuetztes Terminal- oder Arbeitsplatzrechnernetz implementiert werden kann. Der Kern des Systems stellt ein Werkzeugrahmensystem dar, bestehend aus einem leistungsfaehigen Dialogsystem (Text + Grafik), einem Auskunftsystem, einem universellen Datenhaltungssystem und dem Projekt-Advisor. In diesen Werkzeugrahmen wurden vornehmlich existierende Werkzeuge ''eingehaengt''. In Ausnahmefaellen wurden fehlende Werkzeuge entwickelt, bzw. bestehende Werkzeuge in von den Anwendern gewuenschter Weise erweitert. (orig./RHM)SIGLEAvailable from TIB Hannover: F94B0292 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman