Rotary-Wing Aeroelasticity: Current Status and Future Trends

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76177/1/AIAA-9022-592.pd

Hypolithic Microbial Community of Quartz Pavement in the High-Altitude Tundra of Central Tibet

The hypolithic microbial community associated with quartz pavement at a high-altitude tundra location in central Tibet is described. A small-scale ecological survey indicated that 36% of quartz rocks were colonized. Community profiling using terminal restriction fragment length polymorphism revealed no significant difference in community structure among a number of colonized rocks. Real-time quantitative PCR and phylogenetic analysis of environmental phylotypes obtained from clone libraries were used to elucidate community structure across all domains. The hypolithon was dominated by cyanobacterial phylotypes (73%) with relatively low frequencies of other bacterial phylotypes, largely represented by the chloroflexi, actinobacteria, and bacteriodetes. Unidentified crenarchaeal phylotypes accounted for 4% of recoverable phylotypes, while algae, fungi, and mosses were indicated by a small fraction of recoverable phylotypes

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

Aridity-induced limit to photosynthesis and primary production in the Atacama Desert

Identifying the dry limit to microbial photosynthesis contributes to our understanding of life in extreme environments and to the question of life, past or present, on Mars. Here we report on conditions in the Atacama Desert so dry that photoautotrophic microbes are virtually absent. Across a rainfall gradient, the fraction of translucent stones hosting cyanobacteria drops from 28% to 0.08% in the hyperarid core. The threshold for cyanobacterial survival correlates with mean rainfall of ≤5 mm/year, or 75 hours/yr of liquid water during light conditions suitable for photosynthesis. Across the gradient, cyanobacterial molecular diversity declines three-fold and organic carbon residence times increase by three orders of magnitude. The rare cyanobacteria in the core live slowly (3200 y turnover times) and survive in fertile refuges amidst an essentially abiotic landscape. Applied to Mars our results suggest that photosynthetic life is unlikely on the surface of that dry world

Utilization of a zero power reactor for examination of operator influence on reactor control

The reactor operator is an inseparable part of reactor safety and his actions influence the course of the reactor transients. Understanding the operator’s effect on reactor control thus contributes to the knowledge of the safe operation of nuclear reactors. Complementary to studies performed on simulators, or utilizing standard reactor or plant operational data, the dedicated experiments at research reactors can help to improve the insight into human aspects of reactor control. The potential of research reactors to study the human operator aspects of reactor control is broad; the related activities thus may also help to increase the utilization of research reactor facilities. The paper summarizes the considerations that had to be assessed during the implementation of such experiments at the VR-1 research reactor from the viewpoint of the reactor facility. Further, it recapitulates the activities that have been performed in this field at the VR-1 reactor in the collaboration of the Czech Technical University in Prague with the Defence Academy of the United Kingdom in the previous years