Genetically determined differences in antibacterial activity of macrophages are expressed in the environment in which the macrophage precursors mature

Genetically determined enhanced resistance of C57BL-derived mouse strains to infection with Listeria monocytogenes can be attributed to a superior antibacterial activity of effector macrophages, regulated by a single, autosomal, dominant, gene. The present experiments investigated the phenotypic expression of this gene in the macrophage response. Radiation bone marrow chimeras between H-2 compatible B10.A/SgSn (Listeria-resistant) and A/J (Listeria-sensitive) mouse strains were infected with Listeria and their anti-listerial resistance measured. B10.A/SgSn hosts showed enhanced resistance as compared to A/J hosts, regardless of the genotype of the donor bone marrow used to reconstitute the chimeric hosts. The level of enhanced antibacterial activity of macrophages in the resistant strain is therefore determined by the genotype of the host, not of the macrophage precursor. Thus, the macrophage response to Listeria is expressed phenotypically at the level of environmental factors in the host that regulate monocyte/macrophage proliferation and/or differentiation rather than being expressed as an inherent property of the macrophage per se.     

A COMPARISON OF SOME CYCLOHEXAMINE BASED DRUG COMBINATIONS FOR CHEMICAL RESTRAINT OF SOUTHERN ELEPHANT SEALS (MIROUNGA LEONINA)

This study compared the effects of drug combinations commonly used for chemical restraint of southern elephant seals. The combinations were: ketamine and diazepam, ketamine and midazolam, ketamine and xylazine, and tiletamine and zolazepam. The main aims were to gather basic information regarding the response of the animals to the different combinations, and to determine which were most useful for routine chemical restraint. All drug combinations could be used safely although apnea and whole-body shaking occurred with each. There were significant differences in several of the responses measured. Poor muscle relaxation and prolonged apnea were associated with ketamine and diazepam use. Animals given ketamine and xylatine were more depressed, took longer to recover, had a higher incidence of thermoregulatory problems, and lower heart rate than after other combinations. Ketamine and midazolam and tiletamine and zolazepam produced fewer complications than the other drug combinations, and tiletamine and zolazepam showed greater predictability of response and ease of use, making it preferable for use by people with little experience in anesthesia of elephant seals.     

A new stochastic dynamic tool to improve the accuracy of mortality estimates for bats killed at wind farms

Although generally considered environmentally friendly, wind power has been associated with extensive mortality of birds and bats. In this perspective, there is a need for reliable estimates of fatalities at wind farms, where the heterogeneity of the basic information, used among environmental assessment studies, is unlikely to support an accurate universal estimation method. We tested the applicability of the Stochastic Dynamic Methodology (StDM) to estimate bat fatalities, based on multifactorial cause–effect relationships (by integrating multi-model inference statistical analysis and dynamic modelling) between mortality estimates, detected fatalities and the selected key-components of the reality, such as the real number of bat mortalities simulated, the rate of carcasses removal, the searcher efficiency, the monitoring periodicity and the number of turbines for different realistic scenarios associated with particular wind farm conditions. Although some existing mortality estimators are considered accurate, the choice of a given universal formula for all mortality assessments, based on deterministic parameters and assumptions, may originate unsuspected errors. Therefore, we propose a flexible dynamic modelling framework, the StDM estimator, where the obtained algorithms are adaptable to the universe of application intended. The StDM estimator takes into account random, non-constant and scenario dependent parameters, providing bias-corrected estimates. The StDM estimator was applied for the European wind farm context and validated in the most cases tested, through the confrontation with independent data. Overall, this approach is considered a valuable tool to improve the quality of mortality estimates at onshore wind facilities, within the local, environmental and methodological gradients (including the cases where no mortality is detected), namely in the scope of environmental impact assessments and general ecological monitoring programmes.