Cannibalistic behaviour in the harpacticoid copepod Tigriopus fulvus

The results reported here demonstrate the existence of cannibalistic behaviour in laboratory-reared Tigriopus fulvus (Fischer, 1860) females towards first-stage non-related nauplii; mothers, sparing their own offspring, do not share this behaviour. The phenomenon is related to the probability of nauplius/female encounters. It is suggested that mother/offspring recognition is mediated by a chemical compound.     

Honeybee glucose oxidase—its expression in honeybee workers and comparative analyses of its content and H2O2-mediated antibacterial activity in natural honeys

Antibacterial properties of honey largely depend on the accumulation of hydrogen peroxide (H₂O₂), which is generated by glucose oxidase (GOX)-mediated conversion of glucose in diluted honey. However, honeys exhibit considerable variation in their antibacterial activity. Therefore, the aim of the study was to identify the mechanism behind the variation in this activity and in the H₂O₂ content in honeys associated with the role of GOX in this process. Immunoblots and in situ hybridization analyses demonstrated that gox is solely expressed in the hypopharyngeal glands of worker bees performing various tasks and not in other glands or tissues. Real-time PCR with reference genes selected for worker heads shows that the gox expression progressively increases with ageing of the youngest bees and nurses and reached the highest values in processor bees. Immunoblot analysis of honey samples revealed that GOX is a regular honey component but its content significantly varied among honeys. Neither botanical source nor geographical origin of honeys affected the level of GOX suggesting that some other factors such as honeybee nutrition and/or genetic/epigenetic factors may take part in the observed variation. A strong correlation was found between the content of GOX and the level of generated H₂O₂ in honeys except honeydew honeys. Total antibacterial activity of most honey samples against Pseudomonas aeruginosa isolate significantly correlated with the H₂O₂ content. These results demonstrate that the level of GOX can significantly affect the total antibacterial activity of honey. They also support an idea that breeding of novel honeybee lines expressing higher amounts of GOX could help to increase the antibacterial efficacy of the hypopharyngeal gland secretion that could have positive influence on a resistance of colonies against bacterial pathogens.     

Impact of air pollution on outdoor cultural heritage objects and decoding the role of particulate matter: a critical review

Environmental Science and Pollution Research - Atmospheric gases and particulate matter (PM) in contact with the material’s surface lead to chemical and physical changes, which in most cases...