Sub-series and sub-epochs are informal units and should continue to be omitted from the International Chronostratigraphic Chart

In June 2016 the Paleogene, Neogene, and Quaternary subcommissions (ISPS, SNS, SQS) of the International Commission on Stratigraphy (ICS) voted on whether to formalize sub-series and their geochronologic equiva-lents, sub-epochs. The vote required a 60 percent major-ity for the proposal to be forwarded to the ICS for further consideration. That majority was not achieved, albeit by a narrow margin, hence sub-series and sub-epochs are currently to be regarded as informal, and if used should carry a lower case modifier, as in lower Miocene and early Pleistocene. To accompany the vote, those who favoured continuation of informal usage were asked to prepare a short summary of the main arguments in support of their viewpoint, as were the proponents of the formalization case. Although this statement was not originally intended for publication, it is reproduced here at the request of the Former Chair of the ICS, so as to put it on record

Increasing sulfate levels show a differential impact on synthetic communities comprising different methanogens and a sulfate reducer

Methane producing microbial communities are of ecological and biotechnological interest. Syntrophic interactions among sulphate reducers and aceto/hydrogenotrophic and obligate hydrogenotrophic methanogens form a key component of these communities, yet, the impact of these different syntrophic routes on methane production and their stability against sulphate availability are not well understood. Here, we construct model synthetic communities using a sulphate reducer and two types of methanogens representing different methanogenesis routes. We find that tri-cultures with both routes increase methane production by almost two-fold compared to co-cultures, and are stable in the absence of sulphate. With increasing sulphate, system stability and productivity decreases, and does so faster in communities with aceto/hydrogenotrophic methanogens despite the continued presence of acetate. We show that this is due to a shift in these methanogens’ metabolism towards co-utilisation of hydrogen with acetate. These findings indicate the important role of hydrogen dynamics in the stability and productivity of syntrophic communities

Modularized Air-Launch with Virgin Orbit\u27s LauncherOne System: Responsive SmallSat Constellation Construction Measured in Hours, Not Months

As small satellites and the constellations they comprise have become increasingly prevalent, there has been greater interest in the value added by agile and responsive launch systems. Responsiveness, defined here as the ability of a launch vehicle to react quickly and positively to changing payload, customer, or situational constraints, is a capability that has largely been enabled by the rise of the smallsat launch industry and introduces a new set of considerations for smallsat mission stakeholders. This work examines the relative advantage of an air-launched small satellite launch vehicle network for rapid deployment of small satellite constellations, using Virgin Orbit’s LauncherOne system and three hypothetical constellation architectures. Using a combinatoric approach to analyze the possible launch manifests for hypothetical constellations, the impacts of geographic launch site positioning and launch vehicle recycle time on constellation injection time and thereby time-to-market for the constellation missions’ provided service are examined. It is demonstrated that the air launched architecture requires a third as many launch platforms at fewer activated spaceports than an equivalently performing fixed-site launch network, among other advantages. Gaps in the existing policy framework to support responsive launch as well as a plan for future work within this research area are then identified

Web-based virtual reference services: a panel discussion

pp. 63-6

Building a Global Launch Network: Extending the Reach of Dedicated Small Satellite Launch Using New, Data-Driven Spaceport Assessment Tools

The proliferation and sustained growth of small satellite architecture solutions, once an uncertain aspect of tomorrow’s space industry, are now largely perceived as a firm reality. Recent trends continue to show an increasing fraction of launch industry revenue being captured by small and dedicated launch vehicles, such as Virgin Orbit’s LauncherOne. Concurrently, another indicator of small satellite proliferation are recent announcements of increased rideshare opportunities by large launch vehicle operators. As numerous dedicated and rideshare launches emerge as solutions for small satellite customers, understanding the relative advantages and performance of these vehicles will be crucial to satisfy not only single launch, but broader architectural mission needs. Virgin Orbit and VOX Space have presented how a responsive air-launched architecture with multiple hosting spaceports and modularized systems at each can be leveraged to launch entire constellations within days. We have since continued to grow our spaceport network to support domestic and international mission planners that desire a launch vehicle that isn’t constrained to a permanent fixed site or departure corridor. Building upon that work, new analytical methods to analyze and communicate the advantages of air-launch from spaceports around the globe have been devised. Specifically we will quantitatively show how commercial and national security missions, especially in an era that require hybrid architectures, are improved with a geographically flexible and distributed launch capability. Tens of thousands of launches from unique sites are simulated to support various mission types. The result is an explicit evaluation of how the flexibility, ease-of-access, and unconstrained orbital inclination ranges of a global launch network can support hybrid system needs in ways that no other comparable launch system can, dedicated or otherwise

Energy storage for power flow management and voltage control on an 11 kV UK distribution network”.

ABSTRAC

Single cell fluorescence imaging of glycan uptake by intestinal bacteria

Microbes in the intestines of mammals degrade dietary glycans for energy and growth. The pathways required for polysaccharide utilization are functionally diverse; moreover, they are unequally dispersed between bacterial genomes. Hence, assigning metabolic phenotypes to genotypes remains a challenge in microbiome research. Here we demonstrate that glycan uptake in gut bacteria can be visualized with fluorescent glycan conjugates (FGCs) using epifluorescence microscopy. Yeast α-mannan and rhamnogalacturonan-II, two structurally distinct glycans from the cell walls of yeast and plants, respectively, were fluorescently labeled and fed to Bacteroides thetaiotaomicron VPI-5482. Wild-type cells rapidly consumed the FGCs and became fluorescent; whereas, strains that had deleted pathways for glycan degradation and transport were non-fluorescent. Uptake of FGCs, therefore, is direct evidence of genetic function and provides a direct method to assess specific glycan metabolism in intestinal bacteria at the single cell level.</p