The Effect of Varying Distances from the Wind Turbine on Meat Quality of Growing-Finishing Pigs

This study was conducted to assess the effect of rearing pigs at three different distances from a wind turbine (50, 500 and 1000 m) on the physicochemical properties and fatty acid composition of loin and neck muscles. The experiment was carried out on 30 growing-finishing pigs, derived from Polish Landrace × Polish Large White sows mated to a Duroc × Pietrain boar. The results obtained during the noise measurement showed that the highest level of noise in the audible and infrasound range was recorded 50 m from the wind turbine. Rearing pigs in close proximity to the wind turbine (50 m) resulted in decreased muscle pH, total heme pigments and heme iron as well as reduced content of C18:3n-3 fatty acid in the loin muscle. Loins of pigs reared 50 m from the wind turbine were characterized by significantly lower iron content (6.7 ppm g-1) compared to the loins of pigs reared 500 and 1000 m from the wind turbine (10.0-10.5 ppm g-1). The concentration of α-linolenic acid (C18:3n-3) in loin and neck muscles decreased as the distance from the wind turbine increased. Avoiding noise-induced stress is important not only for maintaining meat quality but also for improving animal welfare.

Fluorescence quenching and kinetic studies of conformational changes induced by DNA and cAMP binding to cAMP receptor protein from Escherichia coli

Cyclic AMP receptor protein (CRP) regulates the expression of more then 100 genes in Escherichia coli. It is known that the allosteric activation of CRP by cAMP involves a long-distance signal transmission from the N-terminal cAMP-binding domain to the C-terminal domain of CRP responsible for the interactions with specific sequences of DNA. In this report we have used a CRP mutant containing a single Trp13 located in the N-terminal domain of the protein. We applied the iodide and acrylamide fluorescence quenching method in order to study how different DNA sequences and cAMP binding induce the conformational changes in the CRP molecule. The results presented provide evidence for the occurrence of a long-distance conformational signal transduction within the protein from the C-terminal DNA-binding domain to the N-terminal domain of CRP. This conformational signal transmission depends on the promoter sequence. We also used the stopped-flow and Forster resonance energy transfer between labeled Cys178 of CRP and fluorescently labeled DNA sequences to study the kinetics of DNA-CRP interactions. The results thus obtained lead to the conclusion that CRP can exist in several conformational states and that their distribution is affected by binding of both the cAMP and of specific DNA sequences.