Muscarinic acetylcholine receptor down-regulation limits the extent of inhibition of cell cycle progression in Chinese hamster ovary cells.

Cellular desensitization is believed to be important for growth control but direct evidence is lacking. In the current study we compared effects of wild-type and down-regulation-resistant mutant m3 muscarinic receptors on Chinese hamster ovary (CHO-K1) cell desensitization, proliferation, and transformation. We found that down-regulation of m3 muscarinic acetylcholine receptors was the principal mechanism of desensitization of receptor-activated inositol phosphate phospholipid hydrolysis in these cells. Activation of wild-type and mutant receptors inhibited anchorage-independent growth as assayed by colony formation in agar. However, the potency for inhibition of anchorage-independent growth was greater for cells expressing the mutant receptor. Activation of either receptor also initially inhibited anchorage-dependent cell proliferation in randomly growing populations. Rates of DNA synthesis and cell division were profoundly reduced by carbachol in cells expressing either receptor at early time points. Analysis of cell cycle parameters indicated that cell cycle progression was inhibited at transitions from G1 to S and G2/M to G1 phases. However, mutant receptor effects on anchorage-dependent growth were sustained, whereas wild-type receptor effects were transient. Thus, receptor down-regulation restored cell cycle progression. In contrast, activation of either receptor blocked entry into the cell cycle from quiescence, and this response was not reduced by receptor down-regulation. Therefore, activation of m3 muscarinic acetylcholine receptors inhibited CHO cell anchorage-dependent and -independent growth. In anchored cells carbachol inhibited the cell cycle at three distinct points. Inhibitions at two of these points were eliminated by wild-type receptor down-regulation while the other was not. These results directly demonstrate that desensitization mechanisms can act as principal determinants of cellular growth responses.

Illinois Phosphorus Effluent Limits: Minimizing the Impacts Through the Use of Non-point Controls at the Springbrook Water Reclamation Center in Naperville, Illinois

Phosphorus pollution is a major concern in Illinois. Excessive amounts of phosphorus can be detrimental to water bodies. To help control phosphorus, the Illinois Pollution Control Board has proposed phosphorus limits on wastewater treatment facility discharges. If enacted, these limits will have negative impacts on the Springbrook Water Reclamation Center in Naperville, Illinois. To minimize these impacts, Naperville can utilize various non-point controls recommended in this paper to decrease the amount of phosphorus entering into the DuPage River and the Springbrook Water Reclamation Center. While these controls will not reduce levels low enough to totally satisfy limits on phosphorus discharges, they will significantly reduce the treatment costs Naperville will need to expend to meet them and be more environmentally effective.

Broadening the Scope of Ethnic Identity: A Social Sustainability Solution for Pan African Communities through Ethnically Relevant Educational Programming

This conceptual study explores ethnic identity development theory in order to argue that ethnic identity development education is a means of developing broad senses of community in the African Diaspora that expand beyond a tribal, local, familial level. This study suggests that the broadening of community understanding would contribute to establishing social sustainability on regional, national and international levels within the Pan African community. Establishing such social sustainability would have direct effects on the areas of economic and environmental sustainability. One of the goals of this project is to offer suggestions for ethnically relevant education that can develop social sustainability in several places throughout the Diaspora, such as in Nigeria where ethnic conflicts are a contemporary concern.

Environmental health, indigenous identity, cultural representations and the production of ecological consciousness in Northern Ontario

The primary goal of this research is to document local perspectives by presenting a set of commentaries and meanings, in the form of narratives, related to environmental health conceptions on an Oji-Cree reserve in Northeastern Ontario, Canada. Through an ethnographic case study, this research explores how the modern-day production of a sociocentric and ecocentric self, as ethnic marker and moral category, is contributing to environmental/community health and well-being on Native reserves. Cultural representations of personhood and community based on the Medicine Wheel model, as a cognitive model, create an ontological paradigm that promotes a holistic foundation for human behaviour and interaction, as well as healthy, sustainable communities.

A highly resistive layer within the crust of X-ray pulsars limits their spin periods

The lack of isolated X-ray pulsars with spin periods longer than 12 s raises the question of where the population of evolved high-magnetic-field neutron stars has gone. Unlike canonical radiopulsars, X-ray pulsars are not subject to physical limits to the emission mechanism nor observational biases against the detection of sources with longer periods. Here we show that a highly resistive layer in the innermost part of the crust of neutron stars naturally limits the spin period to a maximum value of about 10–20 s. This highly resistive layer is expected if the inner crust is amorphous and heterogeneous in nuclear charge, possibly owing to the existence of a nuclear ‘pasta’ phase. Our findings suggest that the maximum period of isolated X-ray pulsars may be the first observational evidence for an amorphous inner crust, whose properties can be further constrained by future X-ray timing missions combined with more detailed models.