Differences in the flight initiation distance near expressways and in open farmland in wintering Common Buzzards (Buteo buteo)

The development of road networks has given rise to man-made wildlife habitats. Birds of prey use roadsides and highway infrastructure as attractive foraging sites. In order to measure reactions to human disturbance, the flight initiation distance (FID) of Common Buzzards (Buteo buteo) foraging on expressways and in open farmland was investigated. The GLM model showed that FID was affected by habitat types, distance from the nearest building and distance from the nearest tree. Common Buzzards have a shorter FID on expressway than in farmland. The distance from the nearest building and the distance from the nearest tree were positively correlated with FID. Our results confirmed the behavioural plasticity of these birds and may provide a theoretical basis for measures aimed at reducing the risk of collisions with moving road vehicles

Use of magnetic nanoparticles as a drug delivery system to improve chlorhexidine antimicrobial activity

Grażyna Tokajuk,1,2 Katarzyna Niemirowicz,1 Piotr Deptuła,1,3 Ewelina Piktel,1 Mateusz Cieśluk,1 Agnieszka Z Wilczewska,4 Jan R Dąbrowski,3 Robert Bucki1 1Department of Microbiological and Nanobiomedical Engineering, Medical University of Białystok, 2Department of Intergrated Dentistry, Medical University of Białystok, 3Department of Materials and Biomedical Engineering, Białystok University of Technology, 4Institute of Chemistry, University of Białystok, Białystok, Poland Abstract: Nanotechnology offers new tools for developing therapies to prevent and treat oral infections, particularly biofilm-dependent disorders, such as dental plaques and endodontic and periodontal diseases. Chlorhexidine (CHX) is a well-characterized antiseptic agent used in dentistry with broad spectrum activity. However, its application is limited due to inactivation in body fluid and cytotoxicity toward human cells, particularly at high concentrations. To overcome these limitations, we synthesized nanosystems composed of aminosilane-coated magnetic nanoparticles functionalized with chlorhexidine (MNP@CHX). In the presence of human saliva, MNPs@CHX displayed significantly greater bactericidal and fungicidal activity against planktonic and biofilm-forming microorganisms than free CHX. In addition, CHX attached to MNPs has an increased ability to restrict the growth of mixed-species biofilms compared to free CHX. The observed depolarization of mitochondria in fungal cells treated with MNP@CHX suggests that induction of oxidative stress and oxidation of fungal structures may be a part of the mechanism responsible for pathogen killing. Nanoparticles functionalized by CHX did not affect host cell proliferation or their ability to release the proinflammatory cytokine, IL-8. The use of MNPs as a carrier of CHX has great potential for the development of antiseptic nanosystems. Keywords: chlorhexidine, magnetic nanoparticles, antimicrobial properties, anti-biofil