Influence of extraordinary floods on wildlife parasites: the case of gastrointestinal helminths and protozoa of wild canids from the Iberá Ecoregion, Argentina.

Parasites are natural components of ecosystems and play a significant role in the dynamics of wild animal populations. Although the environment of parasites is primarily defined by the host, most life cycles involve stages that must endure external conditions. Rainfall and flooding events are important factors that might influence the transport of parasitic stages, altering soil moisture levels, and resulting in a favorable environment for parasite survival and development. We assessed whether an extraordinary flood event modified the occurrence of gastrointestinal parasites (nematodes and protozoa) in wild canids in two protected areas in northern Argentina. From 2016 to 2018, we collected fecal samples of two fox species, Lycalopex gymnocercus and Cerdocyon thous, and examined the presence of nematodes and protozoa. We assessed changes in the occurrence of these parasites after a flood event, while adjusting for potential confounders (i.e., monthly average temperature, season, host species, site). In a second stage of the analysis, we evaluated whether part of the effect was caused by changes in soil moisture, by adding normalized difference water index as an independent variable. We found that the presence of nematodes in foxes was higher after flooding than before flooding, and this association was not explained by changes in the soil moisture. On the other hand, the flood event was not relevant for protozoa. Stronger and long-lasting flood events are expected due to the effect of global warming on El Niño events, and this may increase and intensify the spread of some parasites affecting wildlife, which could also be of public health concern.

Enhanced bacterial uptake and bactericidal properties of ofloxacin loaded on bioadhesive hydrogels against Pseudomonas aeruginosa.

Carbomer hydrogels 971pNf, 934pNf and 940Nf loaded with ofloxacin were characterized and their antimicrobial properties evaluated. bactericidal profiles show improved efficacy and prolonged activity exhibited by ofloxacin-containing hydrogels against Pseudomonas aeruginosa. Analysis of bactericidal index (BI) values after a short time of drug exposure confirms the higher potency of hydrogels compared with that of ofloxacin. Increased BI values observed after 24 h indicate prolonged action against the microorganisms evaluated. The bacterial uptake of ofloxacin from hydrogels was higher than that obtained with a solution of free ofloxacin in both fluoroquinolone-sensitive and -resistant P. aeruginosa. The improved uptake in fluoroquinolone-resistant isolates was correlated with the viscosity of hydrogels. The performance of hydrogels seems to be related to their bioadhesive properties that allow prolonged contact time and the release of an effective amount of drug close to bacterial cells. Hence, hydrogels could be used in the development of more effective formulations for topical administration of antibiotics. Improved performance of an old antibiotic can preserve the use of new generation fluoroquinolones.

Using cognitive learning theory to design effective on-line statistics tutorials.

Careful attention to principles of learning can improve the design of Web-based lessons and tutorials. Tutorials from the Web Interface for Statistics Education (WISE; http:¿wise.cgu.edu) demonstrate how specific principles can be integrated into Web design to enhance learning in two areas. First, the impact of students' poor self-regulation abilities on Web-based learning is considered. Second, evidence that specific types of visual presentations improve learning is discussed. Finally, the need for empirical evaluation is emphasized. Specific research and examples from the WISE project are used to illustrate each of these points.