Antimutagenic systems based on chitosan conjugates with plant antioxidants

It was shown using various methods that the radical scavenging and radical scavenging activities of chitosan conjugates with phenolic antioxidants of plant origin significantly exceed the corresponding values of their low molecular weight analogs (gallic and syringic acids, quercetin and dihydroquercetin). Cytogenetic analysis of human peripheral blood lymphocytes demonstrated that the conjugates showed pronounced antimutagenic efficiency when the cells were γ-irradiated in vitro at a dose of 2 Gy.     

Trainmasters or Easyjet pilots? Historical production,labor organizing,and the Spanish engine drivers’ union

This article presents an analysis of the relationship between historical memory and the emergence and reproduction of a specific model of unionism. I argue that in order to understand the militant particularism of the Spanish engine drivers, we need to look at the historical representations that it is embedded in. Recourse to a generational framework makes possible the sustained presentation of the union as a case of successful workers’ organizing, in spite of evidence to the contrary. The historical ethnographic analysis of SEMAF, the Spanish engine drivers’ union, contributes to the analysis of historical memory within the contemporary anthropology of class. The article contributes to theoretical debates in the anthropology of class by reclaiming Michel Trouillot’s conceptualization of the historical process. Two aspects of Trouillot’s work are singled out: his dynamic understanding of the process of historical production and the corollary formulation of the overlapping capacities in which people participate in it (as agents, actors, and subjects) and his emphasis on the importance of expanding scholarly views of the field of historical production.     

2',3'-Dideoxy-3'-aminonucleoside 5'-triphosphates inhibit the repair of DNA in rat liver chromatin

2',3'-Dideoxy-3'-aminonucleoside 5'-triphosphates are shown to be strong inhibitors of repair DNA synthesis in gamma-irradiated rat liver chromatin. The activity of these compounds is comparable with that of the most effective inhibitor of the DNA polymerase beta-catalyzed repair DNA synthesis.     

Critical threshold meal size and molt initiation in Rhodnius prolixus

The molting process and body growth in Rhodnius prolixus (Hemiptera: Reduviidae) (Ståhl, 1859) are significantly influenced by the availability and quality of food. Based on the body weight of each stage, the present study provides estimates of a potential critical weight threshold required for molt initiation in R. prolixus. In addition, a new measure given by the area under the weight curve is proposed, which encapsulates both body weight and time. It is shown that this measure is consistent with the data, and allows the estimation of a pre‐refractory period (i.e. the time interval between the moment at which the critical weight threshold is reached and the moment when no further meals are accepted). The present analysis estimates the critical weight threshold as 1.6, 5.3, 12.9, 42.0 and 97.0 mg for stages 1–5, respectively, whereas the values of the area under the curve threshold as 5, 16, 31.2, 159.7 and 329.9 mg days for stages 1–5, respectively. The results of the present study confirm the existence of a weight‐dependent mechanism for the initiation of molting in R. prolixus.     

Autonomy,productiveness, and community: the rise of inequality in an Amazonian society

In Amazonian societies, autonomy is said to be a core value motivating egalitarian politics. This article shows how the quest for autonomy and productiveness presently sets in motion processes that encroach upon these very values. Among the Shuar of Amazonian Ecuador, the realization of autonomy and productiveness increasingly depends on the capture of state resources. Shuar interact with the local state as members of relatively recent sedentary communities and through the mediation of elected leaders. In these processes, ‘community’ itself is transformed: being a channel to regenerate domestic livelihoods, it also becomes an end in itself, giving rise to new economistic attitudes while legitimizing inequalities between commoners and leaders. The article suggests that the pursuit of autonomy and productiveness within a process of village formation is central to the transformation of egalitarianism that occurs when small-scale Amazonian polities engage with nation-state politics.     

Are offspring begging levels exaggerated beyond the parental optimum? Evidence from a bidirectional selection experiment

Parental care involves elaborate behavioural interactions between parents and their offspring, with offspring stimulating their parents via begging to provision resources. Thus, begging has direct fitness benefits as it enhances offspring growth and survival. It is nevertheless subject to a complex evolutionary trajectory, because begging may serve as a means for the offspring to manipulate parents in the context of evolutionary conflicts of interest. Furthermore, it has been hypothesized that begging is coadapted and potentially genetically correlated with parental care traits as a result of social selection. Further experiments on the causal processes that shape the evolution of begging are therefore essential. We applied bidirectional artificial selection on begging behaviour, using canaries (Serinus canaria) as a model species. We measured the response to selection, the consequences for offspring development, changes in parental care traits, here the rate of parental provisioning, as well as the effects on reproductive success. After three generations of selection, offspring differed in begging behaviour according to our artificial selection regime: nestlings of the high begging line begged significantly more than nestlings of the low begging line. Intriguingly, begging less benefitted the nestlings, as reflected by on average significantly higher growth rates, and increased reproductive success in terms of a higher number of fledglings in the low selected line. Begging could thus represent an exaggerated trait, possibly because parent–offspring conflict enhanced the selection on begging. We did not find evidence that we co‐selected on parental provisioning, which may be due to the lack of power, but may also suggest that the evolution of begging is probably not constrained by a genetic correlation between parental provisioning and offspring begging.