The experimental transmission of various mycoplasmas of feline origin to domestic cats (Felis catus)

Mycoplasma felis and M. gatae recovered from domestic cats, M. arginini from a cheetah, an unidentified glucose-fermenting mycoplasma from a lion, and M. pulmonis from a rat were inoculated into specific pathogen free (SPF) kittens by the oral, ocular and nasal routes. During the 21-day experimental period a persistent infection was established in a proportion of the kittens challenged with M. felis, M. gatae and M. arginini. The mycoplasma isolated from the lion created a transitory infection in one kitten, but M. pulmonis could not be recovered even 24 hr after inoculation. None of the organisms investigated showed any pathological effect. The implications of this work in relation to the host-specificity and pathogenicity of the feline mycoplasmas are discussed. Résumé. On a inoculé à des chatons axéniques par les voies orales, oculaires et nasales, un Myco-plasmafelis et un M. gatae recueillis de chats domestiques, un M. arginini recueilli d'un guépard, un mycoplasme non identifié à glucose fermentant recueilli d'un lion et un M. pulmonis recueilli d'un rat. Durant la période expérimentale de 21 jours, on a établi une infection persistante dans une proportion des chatons soumis aux tests de Mycoplasma felis, de M. gatae et de M. agrinini. Le mycoplasma isolé recueilli du lion a créé une infection transitoire chez un chaton, mais le M. pulmonis n'a pu être recueilli, même 24 heures après l'inoculation. Aucun des organismes sous investigation n'a montré d'effets pathologiques. On a discuté des implications de ce travail en relation avec la spécifité d'hôtes et la pathogénicité de mycoplasmes félins. Zusammenfassung. Mycoplasma felis und M. gatae von Hauskatzen erlangt, M. arginini von einem Tschita, ein unidentifiziertes Glukose-fermentierendes Mycoplasma von einem Löwen, und M. pulmonis von einer Ratte wurden in keimfreie (SPF) junge Katzen geimpft, auf oralem, Augen- und Nasenweg. Während der 21 tägigen Versuchsperiode wurde eine anhaltende Infektion in den Katzen festgestellt, die dem M. felis, M. gatae und dem M. agrinini ausgesetzt waren. Das Mycoplasma von dem Löwen abgesondert, verursachte eine vorübergehende Infektion eines Kätzchens, aber M. pulmonis konnte selbst 24 Stunden nach der Impfung nicht gefunden werden. Keines der untersuchten Organismen zeigte irgendwelche pathologischen Effekte. Die Folgerungen dieser Arbeit im Verhältnis zu der Gast-Spezifität und Pathogenizität des Katzen-mycoplasmas sind diskutiert.     

Measurement of superoxide dismutase, diamine oxidase and caeruloplasmin oxidase in the blood of thoroughbreds

Methods were developed for the measurement of superoxide dismutase (SOD), diamine oxidase (DAO) and caeruloplasmin oxidase in the blood of thoroughbred horses. These enzymes were measured in 178 normal thoroughbreds stabled throughout the United Kingdom. The relationships between the activities of SOD, DAO and caeruloplasmin oxidase and the blood concentrations of their associated trace metals (copper, zinc and manganese) were studied in 52 of the thoroughbreds. Trace metals were measured by electrothermal atomic absorption spectrophotometry. No relationships were found between the activities of erythrocyte SOD and serum/whole blood copper, zinc and manganese, or serum DAO and serum copper or zinc concentrations. Caeruloplasmin oxidase in equine blood was found to be correlated to serum copper concentration, r = 0.695 (P less than 0.001) over the normal range. Samples from thoroughbreds with trace metal deficiency or toxicity were not available for study. The observed normal ranges for the activity of these enzymes are as follows: SOD: 50 to 200 units per ml whole blood between 5 and 95 percentiles; DAO: 0.1 to 28.5 units per litre (means = 14.8, SD 7.1) and caeruloplasmin oxidase; 11.6 to 35.8 units per ml (means = 23.7, SD 6.0). For numerical simplicity, the activity of DAO is given in units per litre, compared to units per ml for caeruloplasmin oxidase and SOD.     

Isolation of Leptospira interrogans serovars tarassovi and pomona from dogs

Extract

This communication reports the isolation of Leptospira inter-rogans serovars tarassovi and pomona from dogs in New Zealand.     

Environment. Biodiversity update--progress in taxonomy

Taxonomy and systematics underpin our ability to conserve and benefit from biodiversity in sustainable ways as envisaged under the Convention on Biological Diversity (CBD). Despite progress in phylogenetics towards reconstructing the "Tree of Life" and in biodiversity informatics, the fundamental documentation of species necessary to complete the inventory of life has lagged behind. It is argued that this reflects a lack of appreciation of the role played by species-level taxonomic information in underpinning conservation and sustainable use and under investment in the relevant institutions at the expense of supporting the centralised financial mechanism of the CBD.     

欧洲精细农业的发展

精细农业是基于农田空间与时间信息的变量农作管理来增加经济收入和减少环境影响。在一系列管理体系内,通过采用适当的技术可实现这个目的。工程技术提供了工具及其使用的管理决策。精细农业应用这些新技术来减少对单位面积农田的经营成本,从农场到农田,甚至田间。农场管理相对     

Low expression of nicotinic acetylcholine receptor subunit Mdα2 in neonicotinoid‐resistant strains of Musca domestica L.

BACKGROUND: Neonicotinoid action as well as resistance involves interaction with nicotinic acetylcholine receptors (nAChRs). In the housefly, neonicotinoid resistance also involves cytochrome P450, as indicated by bioassay with synergist as well as altered expression. In bioassay, synergism was only partial and indicated possible target‐site resistance. The nAChR α2 subunit is important in neonicotinoid toxicity to insects, and gene expression of the Mdα2 subunit was investigated in field populations and laboratory strains of neonicotinoid‐resistant and insecticide‐susceptible houseflies, Musca domestica L. The genomic sequence covering exon III–VII of Mdα2 was analysed for mutations. RESULTS: Gene expression profiling of Mdα2 revealed notable differences between neonicotinoid‐resistant and insecticide‐susceptible houseflies. On average, the neonicotinoid‐resistant field population 766b and the imidacloprid selected strain 791imi had 60% lower copy numbers of Mdα2 compared with the susceptible reference strain. Sequencing of exon III–VII of the Mdα2, encoding acetylcholine binding‐site regions and three out of four transmembrane domains, did not reveal any mutations explaining the increased neonicotinoid tolerance in the strains examined. CONCLUSION: Previous discoveries and the results of this study suggest that the neonicotinoid resistance mechanism in Danish houseflies involves both cytochrome P450 monooxygenase‐mediated detoxification and reduced expression of the nAChR subunit α2. Copyright © 2010 Society of Chemical Industry     

Differences in blood supply to the cerebral cortex between sheep and calves during slaughter

Using methylene blue boli, injected via an intracardiac catheter, the blood supply to the brain in two one- to 10-day-old calves and three adult sheep was studied during and after severance of the common carotid arteries and jugular veins. Passage of dye through cerebral vessels could not be observed in the exposed cerebrum of sheep after bilateral severance of major blood vessels. When vessels were severed on one side only, the passage of dye was noted for at least 53 seconds. In calves, after bilateral severance, sequential boli of dye could be detected passing through the cerebral vessels for more than 100 seconds. These results provide an explanation and support for the belief that there are major differences in the onset of insensibility between sheep and calves subsequent to severance of the common carotid arteries and jugular veins. The differences in blood supply to the brain which were demonstrated could be accounted for by differences in the blood supply to the brain by the vertebral artery in sheep and cattle. The effects of slaughter on the blood supply to the eye are discussed as a possible explanation of the disparity between results of studies in this general field which have used retinal responses in their investigations and those which have not.     

Economics of robots and automation in field crop production

Precision Agriculture - This study reviewed research published after 1990 on the economics of agricultural mechatronic automation and robotics, and identified research gaps. A systematic search was...