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1

Intensity of melanin-based color and risk of predation in the Barn Swallow Hirundo rustica

100%
Galvan I., Nielsen J. T., Moller A. P.
Acta Ornithologica
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2014
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tom 49
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nr 1
Predators are supposed to exert strong selection pressures on their prey, especially when phenotypic traits such as secondary sexual characters promote mating success at the expense of costs in terms of natural selection. Signaling theory predicts that individuals of superior phenotypic quality will enjoy an advantage in term of mating success, but also in term of natural selection, if such individuals are in prime condition both before and after development of exaggerated secondary sexual characters. We tested this prediction in the Barn Swallow Hirundo rustica being preyed upon by the Eurasian Sparrowhawk Accipiter nisus, using extensive samples of feathers from prey and non-prey. We measured tail length and coloration of outermost tail feathers in the black area of the proximal and distal part of tail feathers, but also the white spot of the tail feathers. Prey had significantly less dark distal, but not proximal parts of their tails, while there was no difference in coloration of the white spot between prey and non-prey. Prey had significantly paler tail feathers than non-prey, especially among long-tailed individuals. These results suggest that Barn Swallows with long tails that fail to deposit large amounts of melanin in their tail feathers run an elevated risk of predation.
2
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Studies of acrylamide level in coffee and coffee substitutes: influence of raw material and manufacturing conditions

84%
Mojska H., Gielecinska I.
Roczniki Państwowego Zakładu Higieny
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2013
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tom 64
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nr 3
Background. Many animal studies have shown that acrylamide is both neurotoxic and carcinogenic. The first reports of acrylamide actually having been found in foodstuffs were published in 2002 by the Swedish National Food Agency in conjunction with scientists from the University of Stockholm. It has since been demonstrated that acrylamide arises in foodstuffs by the Maillard reaction, ie. between free asparagine and reducing sugars at temperatures >120°C. Coffee in fact, forms one of the principal dietary sources of acrylamide, where it is normally drunk in large quantities throughout many countries worldwide that includes Poland. Thus, it constitutes a major dietary component in a wide range of population groups, mainly ranging from late adolescents to the elderly. Objectives. To determine the acrylamide level in commercial samples of roasted and instant coffee and in coffee substitutes by LC-MS/MS method. The influence of coffee species and colour intensity of coffee on acrylamide level was also detailed. Materials and methods. A total of 42 samples of coffee were analysed which included 28 that were ground roasted coffee, 11 instant coffees and 3 coffee substitutes (grain coffee). Analytical separation of acrylamide from coffee was performed by liquid chromatography followed by tandem mass spectrometry (LC-MS/MS). To evaluate the colour intensity of ground roasted coffee and instant coffee we used method of arranging (sequence). Results. The highest mean acrylamide concentrations were found in coffee substitutes (818 pg/kg) followed by instant coffee (358 pg/kg) and then roasted coffee (179 pg/kg). One single cup of coffee (160 ml) delivered on average from 0.45 pg acrylamide in roasted coffee to3.21 pg in coffee substitutes. There were no significant differences in acrylamide level between the coffee species ie. Arabica vs Robusta or a mixture thereof. The various methods of coffee manufacture also showed no differences in acrylamide (ie. freeze-dried coffee vs agglomerated coffee). A significant negative correlation was observed between acrylamide levels and the intensity of colour in roasted coffee; this was not the case however for instant coffee. Conclusions. It was demonstrated that roasting process had the most significant effect on acrylamide levels in natural coffee, however there were no relationships found with coffee species. Due to the high acrylamide levels demonstrated in coffee substitutes, recommended amounts should be defined and manufacturers should be obliged to reduce such levels in these products.
3

Wplyw syntetycznych ksantofili na cechy jakosciowe jaj indyczych

43%
Strusinska D., Iwanska S., Jankowski J., Opalka A.
Acta Academiae Agriculturae ac Technicae Olstenensis. Zootechnica
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1997
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tom 47
95-105
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