The production and characterisation of an antibody to detect the coccidiostat toltrazuril and its metabolite ponazuril.

The production of an antibody to detect toltrazuril or its metabolite ponazuril is complicated due to structural constraints of conjugating these coccidiostats to a carrier protein. Therefore a search was carried out for a compound that shared a common substructure to use as an antigen mimic. The chosen compound, trifluoraminoether, was conjugated to two carrier proteins (HSA and BTG) and used in the immunisation of six rabbits. Two immunogen doses (1 mg and 0.1 mg) were also used. All six rabbits produced an immunological response to the hapten regardless of the carrier protein or immunogen dose used. The most sensitive polyclonal antibody produced, designated R609, was subsequently characterised. This antiserum exhibited an IC50 of 18 ng ml-1 using a competitive ELISA format. Cross reactivity studies show that this serum is specific for toltrazuril and its metabolites (toltrazuril sulfoxide and toltrazuril sulfone) but does not cross-react with other coccidiostats such as halofuginone, nitroimidazoles or nicarbazin. This is the first reported production of an antibody capable of specifically binding toltrazuril and ponazuril.

Comparison of genetic and morphological methods to detect the presence of American lobsters, Homarus americanus H. Milne Edwards, 1837 (Astacidea: Nephropidae) in Norwegian waters

American lobsters (Homarus americanus H. Milne Edwards, 1837) are imported live to Europe and should according regulations be kept in land-based tanks until sold. In spite of the strict regulations aimed specifically at preventing the introduction of this species into the NE Atlantic, several specimens of H. americanus have been captured in the wild, especially in Oslofjord, Norway since 1999. One of the great concerns is interbreeding between the introduced American species and the local European lobster, H. gammarus (Linnaeus, 1758). For this reason an awareness campaign was launched in 2000 focusing on morphologically "unusual" lobsters caught in local waters. Morphological characters have been based on colour and sub-ventral spines on the rostrum. Two samples of H. americanus were used for comparisons, as well as samples of European lobster from Oslofjord collected in 1992. Previous genetic analyses (allozymes, mtDNA and microsatellite DNA) have demonstrated that the American lobster is distinct from its European counterpart, with several additional alleles at many loci in addition to different allelic frequency distribution of alleles of "shared" alleles. During the present study, thirteen microsatellite loci were tested in the initial screening, and the three most discriminating loci (Hgam98, Hgam197b and Hgam47b) were used in a detailed comparison between the two species. A total of 45 unusual lobsters were reported captured from Ålesund (west) to Oslofjord (southeast) from 2001 to 2005 and these were analysed for the three microsatellite loci. Nine specimens were identified as American lobsters. Comparisons between morphological and genetic characteristics revealed that morphological differences are not reliable in discrimination the two species, or to identify hybrids. Further, some loci display almost no overlapping in allele frequency distribution for the reference samples analysed, thus providing a reliable tool to identify hybrids.

Improved reliability in diagnosing faults using multivariate statistics

This paper analyses multivariate statistical techniques for identifying and isolating abnormal process behaviour. These techniques include contribution charts and variable reconstructions that relate to the application of principal component analysis (PCA). The analysis reveals firstly that contribution charts produce variable contributions which are linearly dependent and may lead to an incorrect diagnosis, if the number of principal components retained is close to the number of recorded process variables. The analysis secondly yields that variable reconstruction affects the geometry of the PCA decomposition. The paper further introduces an improved variable reconstruction method for identifying multiple sensor and process faults and for isolating their influence upon the recorded process variables. It is shown that this can accommodate the effect of reconstruction, i.e. changes in the covariance matrix of the sensor readings and correctly re-defining the PCA-based monitoring statistics and their confidence limits. (c) 2006 Elsevier Ltd. All rights reserved.

Development of a novel DNA microarray to detect bacterial pathogens in patients with chronic obstructive pulmonary disease (COPD)

A novel microarray was constructed with DNA PCR product probes targeting species specific functional genes of nine clinically significant respiratory pathogens, including the Gram-positive organisms (Streptococcus pneumoniae, Streptococcus pyogenes), the Gram-negative organisms (Chlamydia pneumoniae, Coxiella burnetii Haemophilus spp., Legionella pneumophila, Moraxella catarrhalis, and Pseudomonas aeruginosa), as well as the atypical bacterium, Mycoplasma pneumoniae. In a "proof-of-concept" evaluation of the developed microarray, the microarray was compared with real-time PCR from 14 sputum specimens from COPD patients. All of the samples positive for bacterial species in real-time PCR were also positive for the same bacterial species using the microarray. This study shows that a microarray using PCR probes is a potentially useful method to monitor the populations of bacteria in respiratory specimens and can be tailored to specific clinical needs such as respiratory infections of particular patient populations, including patients with cystic fibrosis and bronchiectasis. (C) 2010 Elsevier B.V. All rights reserved.

Decoupled-DFIG fault ride-through strategy for enhanced stability performance during grid faults

This paper proposes a decoupled fault ride-through strategy for a doubly fed induction generator (DFIG) to enhance network stability during grid disturbances. The decoupled operation proposes that a DFIG operates as an induction generator (IG) with the converter unit acting as a reactive power source during a fault condition. The transition power characteristics of the DFIG have been analyzed to derive the capability of the proposed strategy under various system conditions. The optimal crowbar resistance is obtained to exploit the maximum power capability from the DFIG during decoupled operation. The methods have been established to ensure proper coordination between the IG mode and reactive power compensation from the grid-side converter during decoupled operation. The viability and benefits of the proposed strategy are demonstrated using different test network structures and different wind penetration levels. Control performance has been benchmarked against existing grid code standards and commercial wind generator systems, based on the optimal network support required (i.e., voltage or frequency) by the system operator from a wind farm installed at a particular location.

The appraisal of an automated multi-immunoaffinity chromatography system to detect anabolic agents in bile and urine

Screening for residues of anabolic steroids frequently requires extraction from tissues and fluids before analysis. Chemical procedures for these extractions can be complicated, expensive to perform and not ideal for the simultaneous extraction of analytes with different solubilities. Extraction by multi-immunoaffinity chromatography (MIAC) may be used as an alternative. Samples are passed through a column containing a range of antibodies immobilized on an inert support. The desired analytes are bound to their respective antibodies, washed and then eluted by a suitable solvent. The purified extracts can then be incorporated into the analytical tests, The analytes that can be extracted presently are alpha-nortestosterone, zeranol, trenbolone, diethylstilboestrol, boldenone and dexamethasone. Manually, the MIAC procedure is limited to about six columns per operator but bq automating the process using a robotic sample processor (RSP), 48 columns can be run simultaneously during the day or night. The RSP has also been adapted to transfer extracts and reagents on to ELISA plates. The automated system has proved to be a robust and reliable means of screening large numbers of samples for anabolic agents with minimal manual input

Combining biomarker screening and mass-spectrometric analysis to detect hormone abuse in cattle

Since the introduction of the European ban on hormones in 1989, its implementation has proved to be an enormous challenge to regulatory authorities, because the great economic benefits that result from illegal misuse of growth promoters in animal production encourage their continued use. In efforts to challenge black-market trade in hormones, there have been many analytical advances. Recently, both effect-based bioanalysis for screening to target illegal misuse and improved mass-spectrometry-based confirmatory analysis have greatly increased the likelihood of detecting hormone abuse. This review outlines analytical methods currently used for detecting hormone abuse and presents advances in new approaches based on biological determinants that may complement these techniques in the future. (C) 2009 Elsevier Ltd. All rights reserved.