Easier detection of invertebrate "identification-key characters" with light of different wavelengths

Evolutionary arms-races between avian brood parasites and their hosts have typically resulted in some spectacular adaptations, namely remarkable host ability to recognize and reject alien eggs and, in turn, sophisticated parasite egg mimicry. In a striking contrast to hosts sometimes rejecting even highly mimetic eggs, the same species typically fail to discriminate against highly dissimilar parasite chicks. Understanding of this enigma is still hampered by the rarity of empirical tests - and consequently evidence - for chick discrimination. Recent work on Australian host-parasite systems (Gerygone hosts vs. Chalcites parasites), increased not only the diversity of hosts showing chick discrimination, but also discovered an entirely novel host behavioural adaptation. The hosts do not desert parasite chicks (as in all previously reported empirical work) but physically remove living parasites from their nests. Here, I briefly discuss these exciting findings and put them in the context of recent empirical and theoretical work on parasite chick discrimination. Finally, I review factors responsible for a relatively slow progress in this research area and suggest most promising avenues for future research.     

Evaluation of a commercial E<Superscript>rns</Superscript>-capture ELISA for detection of BVDV in routine diagnostic cattle serum samples

Background  

Bovine viral diarrhoea virus (BVDV) is an important pathogen in cattle. The ability of the virus to cross the placenta during early pregnancy can result in the birth of persistently infected (PI) calves. These calves shed the virus during their entire lifespan and are the key transmitters of infection. Consequently, identification (and subsequent removal) of PI animals is necessary to rapidly clear infected herds from the virus. The objective of this study was to evaluate the suitability of a commercial E^rns-capture ELISA, in comparison to the indirect immunoperoxidase test (IPX), for routine diagnostic detection of BVDV within a control programme. In addition, the effect of passive immunity and heat-inactivation of the samples on the performance of the ELISA was studied.     

Gas chromatographic-mass spectrometric determination of total 4-heptanone,a new marker in diabetes mellitus

Total 4-heptanone is the sum of a β-oxocarboxylic acid, 2-ethyl-3oxohexanoic acid, and its decarboxylation product, 4-heptanone.The β-oxocarboxylic acid is found in serum and in urine, and is detected by gas chromatography-mass spectrometry in the form of its methyl ester or its O-methyloximated acid methyl ester. The ketone is detected within the profile of volatile metabolites in serum and in urine. However, the analytical procedure includes some ketone coming from in vitro decarboxylation.Total 4-heptanone is measured by gas chromatography-mass fragmentography. The method includes a quantitative transformation of the β-oxocarboxylic acid into the ketone. A comparative study with 270 patients with diabetes mellitus, 28 healthy individuals and 143 non-diabetic hospitalized patients showed that the urinary excretion of total 4-heptanone is increased in diabetes mellitus. The mean values are 1073 μg per 24 h for diabetics, compared with 207 μg per 24 h and 246 μg per 24 h for healthy individuals and non- diabetic patients, respectively. Diabetic ketoacidosis and fasting conditions decrease the total 4-heptanone.