The activities of total superoxide dismutase (Tot-SOD), manganese-containing superoxide dismutase (Mn-SOD), copper zinc containing superoxide dismutase (Cu/Zn-SOD) and catalase (CAT) protein concentration, as well as protein and SOD electrophoretic profiles in the liver and muscle of barbel (Barbus barbus) and its intestinal parasite Pomphoryinchus laevis from the river Danube, within the suburban area of Belgrade, Serbia (the stretch between Višnjica and Grocka) in spring and summer were investigated. Specific activities of Tot-SOD, Mn-SOD, Cu/Zn-SOD were higher in spring, while specific CAT activity was higher in summer in all investigated samples. Temperature influence on the antioxidant defense enzymes in barbel tissue and in its intestinal parasite Pomphoryinchus laevis, as well as seasonal patterns, are evident. Our work represents the first study of SOD and CAT activities in the barbel and its intestinal parasites and shows that barbel and acanthocephalans are very useful for biomonitoring studies in aquatic ecosystems

This paper focuses on Sen?s concept of contrapreferential choice. Sen has developed this concept in order to overcome weaknesses of the rational choice theory. According to rational choice theory a decision-maker can be always seen as someone who maximises utility, and each choice he makes as the one that brings to him the highest level of personal wellbeing. Sen argues that in some situations we chose alternatives that bring us lower level of wellbeing than we could achieve if we had chosen some other alternative available to us. This happens when we base our decisions on moral principles, when we act out of duty. Sen calls such action a commitment-based action. When we act out of commitment we actually neglect our preferences and thus we make a contrapreferential choice, as Sen argues. This paper shows that, contrary to Sen, a commitment-based action can be explained within the framework of rational choice theory. However, when each choice we make can be explained within the framework of rational choice theory, when in everything we do maximisation principle can be loaded, then the variety of our motives and traits is lost, and the explanatory power of the rational choice theory is questionable. [Projekat Ministarstva nauke Republike Srbije, br. 47009: Evropske integracije i drustveno-ekonomske promene privrede Srbije na putu ka EU) i br. 179015: Izazovi i perspektive strukturnih promena u Srbiji: Strateski pravci ekonomskog razvoja i uskladjivanje sa zahtevima EU]

The aim of this study was to investigate the activity of oxidative stress biomarkers (total superoxide dismutase - Tot SOD; and copper and zinc-containing superoxide dismutase - CuZn SOD; manganese-containing superoxide dismutase - Mn SOD; catalase - CAT; glutathione peroxidase - GSH-Px; and glutathione reductase - GR), as well as the biotransformation phase II enzyme glutathione-S-transferase (GST), in the white muscle of red mullet (Mullus barbatus L.) at Platamuni (PL) and Valdanos (VAL) in the Adriatic Sea during the winter and spring seasons. The obtained results show both site and seasonal influences on the investigated parameters, with lower enzyme activities at VAL than at PL and in spring than in winter

This paper discusses the relations between three forms of altruism: behavioural, evolutionary and motivational. Altruism in a behavioural sense is an act that benefits another person. It can range from volunteering to a charity and helping a neighbour, to giving money to a non-profit organisation or donating blood. People often dedicate their material and nonmaterial resources for the benefit of others to gain psychological, social and material benefits for themselves. Thus, their altruistic acts are driven by egoistic motivation. Also, the final goal of an altruistic act may be the increase in the welfare of a group or adherence to a certain moral principle or a social norm. However, at least sometimes, the welfare of others is the ultimate goal of our actions, when our altruistic acts are performed from altruistic motivation. In evolutionary sense, altruism means the sacrifice of reproductive success for the benefit of other organisms. According to evolutionary theories, behaviour which promotes the reproductive success of the receiver at the cost of the actor is favoured by natural selection, because it is either beneficial for the altruist in the long run, or for his genes, or for the group he belongs to. However, altruism among people emerges as a distinctly human combination of innate and learned behaviours. Not only do we benefit the members of our own group, but we are capable of transcending our tribalistic instincts and putting the benefit of strangers at our own personal expense as our ultimate goal.

Metal pollution of the aquatic environment is of global concern because metals are ubiquitous and can be accumulated in natural habitats as well as in organisms through the food chain. Accumulated metals are capable of inducing toxicity in living organisms, altering their reproductive success, behavior, immune response and biochemical processes. We examined the correlation between the concentrations of 9 metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in the whole body of the river snail Viviparus acerosus, river water and sediment from three Serbian rivers with different levels of metal pollution, the Danube, Tisa and Velika Morava. Data about water quality showed that the concentrations of As, Cr, Fe and Ni were highest in the water of the Danube and of Cu, Mn and Zn in the water of the Velika Morava River. The concentrations of As and Mn were highest in the Danube River sediment, of Cd, Cu, Fe, Pb and Zn in the Tisa and of Cr and Ni in the sediment of the Velika Morava. The concentrations of all of the examined metals, except for Cu, were highest in snails from the Velika Morava. Correspondence analysis showed stronger correlations between metal concentrations in snails and the river sediment than between snails and river water. Several correlations between metal concentrations in snails and river sediment and water were established by Pearson's correlation test. The concentrations of metals in snail bodies were affected to a greater extent by the river sediment than by the river-water metal content. We conclude that V. acerosus has great potential as a bioindicator species of metal pollution in freshwater basins.