8 research outputs found
Creation of a bovine herpes virus 1 (BoHV-1) quantitative particle standard by transmission electron microscopy and comparison with established standards for use in real-time PCR
No full textInternational audienceStandards are pivotal for pathogen quantification by real-time PCR (qPCR); however, the creation of a complete and universally applicable virus particle standard is challenging. In the present study a procedure based on purification of bovine herpes virus type 1 (BoHV-1) and subsequent quantification by transmission electron microscopy (TEM) is described. Accompanying quantitative quality controls of the TEM preparation procedure using qPCR yielded recovery rates of more than 95% of the BoHV-1 virus particles on the grid used for virus counting, which was attributed to pre-treatment of the grid with 5% bovine albumin. To compare the value of the new virus particle standard for use in qPCR, virus counter based quantification and established pure DNA standards represented by a plasmid and an oligonucleotide were included. It could be shown that the numbers of virus particles, plasmid and oligonucleotide equivalents were within one log10 range determined on the basis of standard curves indicating that different approaches provide comparable quantitative values. However, only virus particles represent a complete, universally applicable quantitative virus standard that meets the high requirements of an RNA and DNA virus gold standard. In contrast, standards based on pure DNA have to be considered as substandard due to limited applications.(C) 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved
Card-image public access catalogues (CIPACs) : Issues concerned with their planning and implementation
No full textThis article identifies and discusses the issues and problems that need to be considered in the process of planning and implementing card-image public access catalogues (CIPACs). CIPACs are online library catalogues based on databases of digitised catalogue cards with more or less sophisticated mechanisms for browsing or searching. Solutions of this kind have been implemented by a number of libraries in various countries since the mid-1990s, mainly as inexpensive alternatives to full retrospective conversion of their old catalogues. Based upon a questionnaire and relevant literature, the article looks at the following aspects: cost, conversion speed, universal access, saving of space, preservational aspects, software selection, preparing the card catalogue for conversion, scanning and quality control, image standards, optical character recognition, manual and intellectual input, technological aspects, administrative tools, organisational aspects, peculiarities of old catalogues, presentation of CIPACs to the users, and life expectancy of card-image catalogues
Improvement of a diagnostic procedure in surveillance of the listed fish diseases IHN and VHS
No full textPoult Enteritis and Mortality Syndrome in Turkey Poults: Causes, Diagnosis and Preventive Measures
No full textPoult enteritis and mortality syndrome (PEMS) is one of the most significant problem affecting turkeys and continues to cause severe economic losses worldwide. Although the specific causes of PEMS remains unknown, this syndrome might involve an interaction between several causative agents such as enteropathogenic viruses (coronaviruses, rotavirus, astroviruses and adenoviruses) and bacteria and protozoa. Non-infectious causes such as feed and management are also interconnected factors. However, it is difficult to determine the specific cause of enteric disorders under field conditions. Additionally, similarities of clinical signs and lesions hamper the accurate diagnosis. The purpose of the present review is to discuss in detail the main viral possible causative agents of PEMS and challenges in diagnosis and control
The optimization of oil operation for a dry low NOx gas turbine combustor
No full textAs the market for Gas Turbines becomes more aggressive, and the legislation for emissions more stringent, manufacturers are looking for better ways of becoming competitive. One competitive criteria is the ability to create robust low emission burners. While it is relatively easy to design a premixed burner for natural gas operation, the process involved in producing a reliable Low NOx burner for oil is considerably more complicated. Within the bounds of the given burner geometry, this works surrounds the optimisation of the premix oil mixture in preparation for Gas Turbine combustion, in able to achieve a Dry Low NOx performance with values less than 25ppm.The main development included the use of numerical methods involving CFD codes to vary different nozzle parameters and operating conditions. The author defined the critical parameters for the nozzle design operating in such a burner, and suggested a new type of nozzle. This nozzle was designed and modelled, and proved to be the optimal solution providing the lowest emissions for a Dry oil burner available in the power generation business
