Expression, purification and characterisation of recombinant Escherichia coli derived chicken interleukin-12

Zoonotic viruses, such as H5N1 Avian Influenza, pose major threats to both animals and humans, and with this in mind there is a need for the development of new anti-viral strategies. The cytokine interleukin-12 (IL-12) is known to play a pivotal regulatory role in the anti-viral response due to its role in the induction of the key anti-viral cytokine IFN-gamma. Therefore, strategies which provide a means for the production of therapeutic quantities of IL-12 may be of major benefit. Here we describe the development of biologically active Escherichia coli (E. coli) derived chicken IL-12 (ChIL-12). The single chain ChIL-12 gene was cloned into the pET32b expression vector, transformed into the BL-21 E. coli strain and expression induced with IPTG. Over expressed protein was solubilised with zwittergent detergent and isolated utilising Nickel ion affinity chromatography. Biological activity was determined as ChIL-12 stimulated proliferation of pre-treated T-cells in vitro. This study is the first example of a biologically active E. coli derived IL-12 from a non-mammalian vertebrate subsequently providing a means for testing the anti-viral therapeutic potential of ChIL-12 in an in vivo model.     

Implications of using small meshed gillnets for the sustainability of fish populations: a theoretical exploration based on three case studies

The study explores the impacts of varying gillnet mesh size and fishing level on yield per recruit (Y/R), escapement spawning stock (ESS) and mega‐spawners (MS) of three widely distributed freshwater fishery target species. Y/R is maximised when the optimal length of capture (L_cap) is above the size of maturity (L₅₀). However, the unimodal shape of gillnet selectivity results in lower impacts to ESS and MS with both smaller and larger mesh sizes. Under conditions of moderate exploitation, the fraction of MS was significantly larger if small meshed gillnets were used. This is due to the relatively smaller cumulative vulnerability from small mesh sizes through time, as they target a smaller size range of fish, which also grow more quickly through the vulnerable window due to higher growth rates. Therefore, unlike trawls and beach seines, which select all size classes beyond the minimum length of capture (L_c), small meshed gillnets are not necessarily destructive and may rather promote sustained production by allowing a higher proportion of the spawning biomass to remain in the stock. The work also helps to explain the observation of sustained fish production in many developing countries despite the persistent use of gillnets of small mesh size that target small, under‐sized individuals.     

Antinociceptive and side-effects of hydromorphone after subcutaneous administration in cats

The subcutaneous (SC) route is often chosen for drug administration in cats because it is easier to perform than intravenous (IV) injection and is perceived as less painful than intramuscular (IM) injection. However, little is known of how the route of administration influences the pharmacodynamics of drugs. This study measured the changes in skin temperature and thermal threshold (TT) and recorded the side-effects after SC injection of 0.1mg/kg of hydromorphone in six cats. Time to peak TT was 105min. Skin temperature was elevated at 15min and between 45 and 360min. Five cats vomited and two exhibited marked dysphoria. Compared to previously published studies of IV and IM administration of hydromorphone, the SC route results in a slower onset of peak effect, a shorter duration of antinociception and is associated with more undesirable side-effects. As with IV and IM injections, SC administration of hydromorphone at 0.1mg/kg is associated with a significant elevation in skin temperature. Overall, the SC route appears to have the least utility.     

Comparative assessment of food web structure and fisheries productivity of three reservoirs in Ghana

Three Ghanaian reservoirs (Tono, Bontanga and Golinga) were compared through a food web modelling approach (Ecopath with Ecosim) to assess production characteristics and food web structures. The lakes differ in size and morphology, generating specific conditions for fish growth and production. While the two top fishery target species were Sarotherodon galilaeus (L.) and Oreochromis niloticus (L.) in all reservoirs, the mean trophic level of the catch was lowest in the largest and deepest reservoir (Tono) due to higher trophic level species occupying less accessible deep “refuge” habitats. The smallest lake had the highest fish production under optimal conditions of water supply (17.1 compared with 15.5 and 10.1 t/km²/year for lakes Bontanga and Tono), but it appears to be most vulnerable under conditions of drought. For the planning and construction of adequately sized reservoirs used for fishery and irrigation purposes, the water budget (ratio of inflow and evaporation) needs to be estimated.     

Mit neuen Verfahren gegen Fruchtwickler in Kleingartenanlagen

The availability of pesticides in private gardens is limited by local law in the State of Baden-Württemberg in south-west Germany. Only 26 insecticides, fungicides and molluscicides are permitted. Hence, only pesticides such as Bacillus thuringiensis, Granulosis Virus, pyrethrum or the pheromone mating disruption method (PMDM) can be used for moth control in apple. The use of beneficials like Trichogramma sp. or Chrysoperla carnea is not limited. PMDM had not been previ-ously investigated in allotments until the experiments reported here were carried out in 1998 and 1999. In these experiments, PMDM was compared with the use of the egg parasites, Trichogramma dendrolimi and T. cacoeciae. The observations were done in 102 allotments, each of about 300 m². The gardeners are members of a special club for the allotments and they often organize the bulk acquisition of plants or fertilizers for the club. Sometimes the club obtains plant protection products when something has to be done in all allotments. The codling moth and the plum fruit moth are important pests in these allotments.In 1997, attacks of codling moth were generally low throughout the southern Germany. This was reflected in the allotments where there was less than one per cent fruit damage with PMDM or the egg parasites the following year. During 1999, the attacks were generally much higher resulting in a higher use of insecticides in commercial German orchards. In the allotments, about six to eight per cent of fruits were damaged by the codling moth in both experimental treatments.The results indicate that PMDM can be successful in allotments and is equally as effective as the use of egg-parasites. But further experiments are required.