BackgroundExtremely low-frequency (50 Hz) electromagnetic field (ELF-EMF) is produced by electric power transmission lines and electronic devices of everyday use. Some phenomena are proposed as “first effects” of ELF-EMF: the discrete changes in the membrane potential and the increase of the calcium channel activity as well as the intracellular concentration of Ca2+. Interaction of the scorpion alpha toxin with the sodium channel depends on the orientation of the charges and may be perturbed by changes in the membrane polarization. The toxin induces overexcitability in the nervous system and an increase in the neurotransmitters released with different consequences, mainly the paralysis of muscles. We assumed that the exposure to ELF-EMF 0.7 mT will change the effects of the insect selective scorpion alpha toxin (recombinant LqhαIT from Leiurus quinquestriatus hebraeus) at the level of the cercal nerve function, the synaptic transmission and on the level of entire insect organism. Taking into account the compensatory mechanisms in organisms, we tested in addition ten times higher ELF-EMF on whole insects.MethodsExperiments were performed in vivo on cockroaches (Periplaneta americana) and in vitro – on isolated cockroach abdominal nerve cord with cerci. In biotests, the effects of LqhαIT (10−8 M) were estimated on the basis of the insect ability to turn back from dorsal to ventral side. Three groups were compared: the control one and the two exposed to ELF-EMF – 0.7 and 7 mT. Bioelectrical activity of the cercal nerve and of the connective nerve that leaves the terminal abdominal ganglion was recorded using extracellular electrodes. LqhαIT (5 × 10−8 M) induced modifications of neuronal activity that were observed in the control cockroach preparations and in the ones exposed to ELF-EMF (0.7 mT). The exposure to ELF-EMF was carried out using coils with a size appropriate to the examined objects.ResultsThe exposure to ELF-EMF (0.7 mT) modified the effects of LqhαIT (5 × 10−8 M) on activity of the cercal nerve and of the connective nerve. We observed a decrease of the toxin effect on the cercal nerve activity, but the toxic effect of LqhαIT on the connective nerve was increased. Biotests showed that toxicity of LqhαIT (10−8 M) on cockroaches was reduced by the exposure to ELF-EMF (0.7 and 7 mT).ConclusionsThe exposure to 50 Hz ELF-EMF modified the mode of action of the anti-insect scorpion alpha toxin LqhαIT at cellular level of the cockroach nervous system and in biotests. Toxin appeared as a usefull tool in distinguishing between the primary and the secondary effects of ELF-EMF.
This paper will discuss the Wiindigo, a cannibalistic character among some Indigenous peoples of North America. Illustrated through the Anishinaabeg and Oji-Cree, two Algonquin-speaking Indigenous groups, the Wiindigo serves as a personification of fear and hunger, and alludes to the cultural heritage elements of the boreal forest food system as well as the differing legal systems in Canada. In examining the Wiindigo from the Indigenous cultural and historical perspectives related to the author by several knowledge-holders, as well as from EuroCanadian popular culture representations, the paper illustrates the importance of the Wiindigo to Anishinaabe and Oji-Cree world views, customary governance, and contemporary lived experience.
This article outlines Poplar River First Nation's attempt to designate their traditional trapline territory as part of the UN Educational, Scientific and Cultural Organization's world heritage site nomination called Pimachiowin Aki. Along with other neighbouring Anishinaabeg First Nations involved in this First Nation-led project, Poplar River is using the global infrastructure to meet local needs. Their endeavour to establish permanent protection of their lands so that continuity of cultural practices ensues is a reconceptualization of the meaning of development. In spite of its small population, this Indigenous community's attempt to stand up against non-renewable resource exploitation of their lands carries great weight in Manitoba, and already their unique narrative has captured the attention of Canada and the world.
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