Degradation legacy and current water levels as predictors of carbon emissions from two fen sites

Drainage-induced shifts in physicochemical peat properties are irreversible on a decadal time span. We investigated whether carbon emissions from fen peat can be estimated using two proxies: current water levels and peat properties (as affected by drainage history, i.e. degradation legacy). We collected bare peat monoliths from a long-term drained and an undrained fen. In a crossed design, half of the monoliths was kept wet and the other half was drained. Highest carbon dioxide (CO2) emissions came from the originally undrained peat under low water levels (607 mmol m-2 d-1). Overall, CO2 emissions were primarily determined by drainage history, with 141 % higher emissions from the originally undrained peat. In addition, low current water levels correlated with 42 % higher emissions. Highest methane (CH4) emissions were measured in the originally undrained peat under high water levels (123 mmol m-2 d-1). Overall, CH4 emissions were primarily determined by current water levels, with 430 % higher emissions under high water levels. In addition, the originally undrained peat had 180 % higher emissions. The lower C efflux from originally drained peat correlated with lower concentrations of methanogens and of easily-degradable carbon substrate (cellulose). We conclude that substrate limitation in long-term drained fens ensures low baseline carbon emissions, which provides opportunities for renewed carbon sequestration by rewetting

Robotic Habitat Technologies for Minimizing Crew Maintenance Requirements

NASA’s Lunar Gateway aims to be deployed later in the decade and will serve as an outpost orbiting the moon. This habitat will be utilized as a base for lunar operations as well as future missions to Mars. Unlike the International Space Station (ISS), which maintains three to six astronauts at any given time, the Lunar Gateway will be uncrewed for eleven months out of the year. Over 80% of crew time onboard the ISS is dedicated to logistics, repair, and maintenance, leaving minimal time for scientific research and experimentation. In order to maintain Gateway, robotic systems must be implemented to accomplish maintenance and operational tasks. This paper discusses our team’s proposed dexterous robotic system, which will address routine and contingency operational and maintenance tasks on Gateway. The project is experimentally-based, and split into three approaches: cataloging robotic capabilities via robot/taskboard interactions, logistics management of Cargo Transfer Bags (CTBs), and software development of an AprilTag situational development system. This research project utilizes the unique capabilities of the University of Maryland (UMD) Space Systems Laboratory (SSL), which houses various dexterous robotic manipulators, mock-ups of space habitats, and the Neutral Buoyancy Research Facility (NBRF), a 50-foot diameter, 25-foot deep water tank used to simulate microgravity conditions. By incorporating robotic systems into the architecture of the Lunar Gateway, it will allow for the lunar outpost to be continually operated and maintained while uncrewed, and will allow for astronauts, when present, to focus on maximizing scientific discoveries.NASA RASC-AL 202

Control of human adenovirus type 5 gene expression by cellular Daxx/ATRX chromatin-associated complexes

Death domain–associated protein (Daxx) cooperates with X-linked α-thalassaemia retardation syndrome protein (ATRX), a putative member of the sucrose non-fermentable 2 family of ATP-dependent chromatin-remodelling proteins, acting as the core ATPase subunit in this complex, whereas Daxx is the targeting factor, leading to histone deacetylase recruitment, H3.3 deposition and transcriptional repression of cellular promoters. Despite recent findings on the fundamental importance of chromatin modification in host-cell gene regulation, it remains unclear whether adenovirus type 5 (Ad5) transcription is regulated by cellular chromatin remodelling to allow efficient virus gene expression. Here, we focus on the repressive role of the Daxx/ATRX complex during Ad5 replication, which depends on intact protein–protein interaction, as negative regulation could be relieved with a Daxx mutant that is unable to interact with ATRX. To ensure efficient viral replication, Ad5 E1B-55K protein inhibits Daxx and targets ATRX for proteasomal degradation in cooperation with early region 4 open reading frame protein 6 and cellular components of a cullin-dependent E3-ubiquitin ligase. Our studies illustrate the importance and diversity of viral factors antagonizing Daxx/ATRX-mediated repression of viral gene expression and shed new light on the modulation of cellular chromatin remodelling factors by Ad5. We show for the first time that cellular Daxx/ATRX chromatin remodelling complexes play essential roles in Ad gene expression and illustrate the importance of early viral proteins to counteract cellular chromatin remodelling

Market integration, income inequality, and kinship system among the Mosuo of China.

Increased access to defensible material wealth is hypothesised to escalate inequality. Market integration, which creates novel opportunities in cash economies, provides a means of testing this hypothesis. Using demographic data collected from 505 households among the matrilineal and patrilineal Mosuo in 2017, we test whether market integration is associated with increased material wealth, whether increased material wealth is associated with wealth inequality, and whether being in a matrilineal vs. patrilineal kinship system alters the relationship between wealth and inequality. We find evidence that market integration, measured as distance to the nearest source of tourism and primary source of household income, is associated with increased household income and 'modern' asset value. Both village-level market integration and mean asset value were associated negatively, rather than positively, with inequality, contrary to predictions. Finally, income, modern wealth and inequality were higher in matrilineal communities that were located closer to the centre of tourism and where tourism has long provided a relatively stable source of income. However, we also observed exacerbated inequality with increasing farm animal value in patriliny. We conclude that the forces affecting wealth and inequality depend on local context and that the importance of local institutions is obscured by aggregate statistics drawn from modern nation states.NSF BCS 1461514 - National Science FoundationPublished versio

ROBOTIC TECHNOLOGIES FOR MINIMIZING CREW MAINTENANCE REQUIREMENTS IN SPACE HABITATS

Gemstone Team ASTROThe International Space Station (ISS) is crewed continuously by astronauts conducting scientifc research in microgravity. However, their work is not limited to scientifc research alone; in fact, logistics, maintenance, and repair tasks on the ISS require more than 80% of available crew time, severely limiting opportunities for performing scientifc experiments and technological development. NASA is planning a new project known as Gateway (also referred to as the Lunar Orbital Platform-Gateway). This station will orbit the Moon and be uncrewed for 11 months per year. Astronauts will only be present in the outpost for a limited period of time and will not always be available for continuous repairs and maintenance, as is required for Gateway to operate. Therefore, robotic system(s) are necessary to regularly accomplish these tasks both in the absence and presence of astronauts. Throughout this project, Team ASTRO (Assessment of Space Technologies for Robotic Operations) explored the feasibility of integrating dexterous robotic systems in space habitat architectures to perform routine and contingency operational and maintenance tasks. Ultimately, this allows for astronauts, when present, to focus on exploration and scientifc discoveries. The team conducted this research through three approaches: Gateway component analog taskboard development and end e˙ector assessment, Cargo Transfer Bag (CTB) manipulation and logistics, and AprilTag situational awareness simulation development. Based on analyses and experimental results gained from this research, the team found that robotic systems are feasible alternatives for space habitat operation. Team ASTRO also determined that AprilTags can be used for optimization of the Gateway design to facilitate uncrewed operations and robotic servicing to improve crew productivity when present

To Valhalla by horseback? : horse burial in Scandinavia during the Viking Age

Horse burial probably served several of the ideological functions. Indeed, if we take a cursory glance at horse burials in the archaeological record, it is clear from their marked variation that diverse rationales would have underlain them. Horses are found in both men’s and women’s graves, in both inhumation and cremation burials and in both flat ground and mound burials. In many instances their skeletons have been found fully intact in the grave, while on a more than few occasions they have been found decapitated. Simply stated, a monolithic rule for a horse burial during the Viking Age did not exist. Despite this, a few major trends present themselves in the archaeology. The most eye-catching of these trends is that of horses inhumed in ship burials. Horses and ships are regularly paired in the physical record, with roots reaching back to Bronze Age rock art, and appear together in the grave with exceptional frequency. Another trend that comes to light is the 10th century horseman burials which show up primarily in Denmark. These graves characteristically contain rich riding equipment that seems to reflect the emergence of a new type of political/military elite in Scandinavia. The last major group of horse burials I will discuss involves the well-known chamber-graves at Birka. These show a high degree of homogeneity, suggesting a well-organized military presence in the early Viking town. Of the archaeological analysis, the three above topics will receive the stallion’s share of the focus. To offer a more complete picture of the practice, however, I will do a case study on a particularly intriguing grave-find from Arninge in Sweden and, a bit further on, bring the horse burial evidence from Lindholm Høje in northern Denmark into our discussion as well