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

Post-mortem volatiles of vertebrate tissue

Volatile emission during vertebrate decay is a complex process that is understood incompletely. It depends on many factors. The main factor is the metabolism of the microbial species present inside and on the vertebrate. In this review, we combine the results from studies on volatile organic compounds (VOCs) detected during this decay process and those on the biochemical formation of VOCs in order to improve our understanding of the decay process. Micro-organisms are the main producers of VOCs, which are by- or end-products of microbial metabolism. Many microbes are already present inside and on a vertebrate, and these can initiate microbial decay. In addition, micro-organisms from the environment colonize the cadaver. The composition of microbial communities is complex, and communities of different species interact with each other in succession. In comparison to the complexity of the decay process, the resulting volatile pattern does show some consistency. Therefore, the possibility of an existence of a time-dependent core volatile pattern, which could be used for applications in areas such as forensics or food science, is discussed. Possible microbial interactions that might alter the process of decay are highlighted

Force Generation Profiles of Para-Nordic Sit-Skiers Representing Different Physical Impairments

Purpose To biomechanically profile force generation connected to the complex role of the trunk in double poling in a representative sample of Para-Nordic sit-skiers. Methods Twelve male World Cup Para-Nordic sit-skiers (sport classes: LW10–12) were skiing on flat snow terrain at submaximal speed of 4.5 m/s (~ 73% maximum speed). 2D video (50 Hz) and pole force analyses (1000 Hz) were performed synchronously, examining angle, force and cycle characteristics to analyse the role of the trunk in generating propulsion. Results LW10–11.5 skiers lost between 21% and 4% propulsive force versus LW12 athletes only due to different geometrics of the trunk and pole angle at an equal axial pole force. While LW10–11 skiers indicated trunk extension or position maintenance during pole thrust, LW11.5–12 skiers showed strong trunk flexion combined with smaller pole angles to the ground. Hence, LW11.5–12 skiers could create larger propulsive forces and therefore greater cycle lengths at lower cycle rates at the same speed. Maximum speed increased from LW10 to LW12 and was significantly correlated to trunk flexion range of motion (r = 0.63) and cycle length (r = 0.59). Trunk flexion ROM showed a significant relationship to the impulse of propulsive force (r = 0.63) and pole angle to the ground (r = − 0.76) (all P < 0.05). Conclusion The impact of impairment on the force production profiles and its physiological-biomechanical consequences need further investigation also in other terrains and at wider spectrums of skiing speeds. The evident problem of low numbers of LW10–11 skiers in World Cup needs creative future solutions for research