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Experimental Simulation of Volatile Organic Contributions to Planetary Atmospheres and Surfaces
We present the results of a new simulation of the atmospheric entry heating experienced by extraterrestrial dust particles, quantifying their volatile loss into the early Earth atmosphere and characterising their organic volatile components
Enantioselective Organocatalytic Intramolecular Diels−Alder Reactions. The Asymmetric Synthesis of Solanapyrone D
The first direct enantioselective organocatalytic intramolecular Diels−Alder reaction has been accomplished. The use of iminium catalysis has provided a new catalytic strategy for the enantioselective [4 + 2] cycloisomerization of a wide variety of tethered diene-enal systems. The use of imidazolidinones 1 and 2 as the asymmetric catalysts has been found to mediate the enantioselective construction of [4.4.0] and [4.3.0] ring systems. Application of this methodology to the highly efficient asymmetric synthesis of the marine metabolite solanpyrone D has also been accomplished. A diverse spectrum of aldehyde substrates can also be accommodated in this new organocatalytic transformation. Importantly, this technology has been utilized to execute the first enantioselective, catalytic Type II IMDA reaction
Passive Wireless SAW Sensors for IVHM
NASA aeronautical programs require integrated vehicle health monitoring (IVHM) to ensure the safety of the crew and the vehicles. Future IVHM sensors need to be small, light weight, inexpensive, and wireless. Surface acoustic wave (SAW) technology meets all of these constraints. In addition it operates in harsh environments and over wide temperature ranges, and it is inherently radiation hardened. This paper presents a survey of research opportunities for universities and industry to develop new sensors that address anticipated IVHM needs for aerospace vehicles. Potential applications of passive wireless SAW sensors from ground testing to high altitude aircraft operations are presented, along with some of the challenges and issues of the technology
Enantioselective Organocatalytic Intramolecular Diels-Alder Reactions. The Asymmetric Synthesis of Solanapyrone D
Insomnia and Mild Cognitive Impairment
Insomnia is a common problem in older people, especially in patients with mild cognitive impairment (MCI) whose circadian rhythm is often compromised. Insomnia exerts such a toll on caregivers that it is frequently the primary reason for seeking to institutionalize their loved ones. Three different types of insomnia are recognized: sleep-onset or initial insomnia, sleep maintenance or middle insomnia, and early morning awakening or late insomnia. Nocturnal hypoglycemia, as a cause of middle insomnia, is the main focus of this case study. Other types of insomnia are also briefly reviewed. The management of insomnia is then discussed including sleep hygiene, the usefulness and potential drawbacks of dietary supplements, nonprescription over-the-counter preparations and prescription hypnotics. Sleep architecture is then briefly reviewed, emphasizing the importance of its integrity and the role of each sleep stage
Oral Microbiome Diversity in Chimpanzees from Gombe National Park
Historic calcified dental plaque (dental calculus) can provide a unique perspective into the health status of past human populations but currently no studies have focused on the oral microbial ecosystem of other primates, including our closest relatives, within the hominids. Here we use ancient DNA extraction methods, shotgun library preparation, and next generation Illumina sequencing to examine oral microbiota from 19 dental calculus samples recovered from wild chimpanzees (Pan troglodytes schweinfurthii) who died in Gombe National Park, Tanzania. The resulting sequences were trimmed for quality, analyzed using MALT, MEGAN, and alignment scripts, and integrated with previously published dental calculus microbiome data. We report significant differences in oral microbiome phyla between chimpanzees and anatomically modern humans (AMH), with chimpanzees possessing a greater abundance of Bacteroidetes and Fusobacteria, and AMH showing higher Firmicutes and Proteobacteria. Our results suggest that by using an enterotype clustering method, results cluster largely based on host species. These clusters are driven by Porphyromonas and Fusobacterium genera in chimpanzees and Haemophilus and Streptococcus in AMH. Additionally, we compare a nearly complete Porphyromonas gingivalis genome to previously published genomes recovered from human gingiva to gain perspective on evolutionary relationships across host species. Finally, using shotgun sequence data we assessed indicators of diet from DNA in calculus and suggest exercising caution when making assertions related to host lifestyle. These results showcase core differences between host species and stress the importance of continued sequencing of nonhuman primate microbiomes in order to fully understand the complexity of their oral ecologies
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