Methanotrophy, Methylotrophy, the Human Body and Disease

Methylotrophic Bacteria use one-carbon (C1) compounds as their carbon source. They have been known to be associated to the human body for almost 20 years as part of the normal flora and were identified as pathogens in the early 1990s in end-stage HIV patients and chemotherapy patients. In this chapter, I look at C1 compounds in the human body and exposure from the environment and then consider Methylobacterium spp. and Methylorubrum spp. in terms of infections, its role in breast and bowel cancers; Methylococcus capsulatus and its role in inflammatory bowel disease, and Brevibacterium casei and Hyphomicrobium sulfonivorans as part of the normal human flora. I also consider the abundance of methylotrophs from the Actinobacteria being identified in human studies and the potential bias of the ionic strength of culture media and the needs for future work. Within the scope of future work, I consider the need for the urgent assessment of the pathogenic, oncogenic, mutagenic and teratogenic potential of Methylobacterium spp. and Methylorubrum spp. and the need to handle them at higher containment levels until more data are available

Southwest Norway at the Pleistocene/ Holocene Transition: Landscape Development, Colonization, Site Types, Settlement Patterns

This is an electronic version of an article published in the Norwegian Archaeological Review© 2003 Copyright Taylor & Francis; Norwegian Archaeological Review is available online at http://www.tandfonline.com/doi/abs/10.1080/00293650307293.This article contributes a western Norwegian perspective to the ongoing debate on the timing and nature of the earliest colonization of northern Europe. Despite there being a theoretical possibility of Late Glacial settlement, currently available data indicate a populating of the area around the termination of the Pleistocene ca. 10,000 (uncalibrated) yr BP. The earliest radiocarbon date in southwest Norway so far, 9750 BP, is only a terminus ante quem. Environmental, economic, technological and social factors involved as a result of the colonization process are discussed briefly, and trends in the archaeological record are emphasized and commented on. The economy reflected by the first complete annual subsistence patterns is interpreted as having been logistically mobile, highly adaptive and generally of opportunistic character. Particular attention is paid to Early Preboreal coastal and inland settlement of the ‘Boknafjord’ and ‘Myrvatn/Fløyrlivatn’ groups, the latter characterized by well-preserved site structures such as tent rings and hearths providing high-resolution radiocarbon dates and palaeobotanical evidence

Population connectivity: dam migration mitigations and contemporary site fidelity in arctic char

Background: Animal feeding and spawning migrations may be limited by physical barriers and behavioral interactions. Dam constructions (e. g. hydropower) commonly include gateways for fish migrations to sustain ecological connectivity. Relative genetic impacts of fish passage devices versus natural processes (e. g. hybrid inferiority) are, however, rarely studied. We examined genetic (i.e. microsatellite) population connectivity of highly migrating lake-dwelling Arctic char (Salvelinus alpinus), introduced 20 generations ago, across and within two subalpine lakes separated by a dam with a subterranean tunnel and spill gates after 7 generations. Due to water flow regime, the time window for fish migration is highly restricted. Results: Char populations, with similar genetic structuring and diversity observed across and within lakes, were admixed across the dam with fishways during feeding. For spawning, however, statistically significant, but very low population differentiation (theta; 0.002 - 0.013) was found in nine out of ten reproductive site comparisons, reflecting interactions between extensive migration (mean first generation (F(0)) = 10.8%) and initial site fidelity. Simulations indicated that genetic drift among relatively small effective populations (mean N(e) = 62) may have caused the observed contemporary differentiation. Novel Bayesian analyses indicated mean contributions of 71% F(0) population hybrids in spawning populations, of which 76% had maternal or paternal native origin. Conclusions: Ecological connectivity between lakes separated by a dam has been retained through construction of fishways for feeding migration. Considerable survival and homing to ancestral spawning sites in hybrid progeny was documented. Population differentiation despite preceding admixture is likely caused by contemporary reduced reproductive fitness of population hybrids. The study documents the beginning stages of population divergence among spatial aggregations with recent common ancestry. Full article available at http://www.biomedcentral.com/1471-2148/11/20