The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Risking the Wrist

Abstract: Background: Carpal tunnel syndrome (CTS) is now one of the most common workplace injuries, with nearly 50% of patients eventually requiring CTS release surgery as a permanent solution. With a concern of a younger incidence of CTS developing in a technology dependent society, some patients may fear even a minimal loss of function. To our knowledge there has been no study comparing forearm grip strength before symptoms develop to grip strength after the procedure has been performed. Objectives: The aim of this study was to determine if there was a significant change in strength of the flexor digitorum superficialis and profundus tendons before and after a carpal tunnel release procedure as a proxy for change in grip strength. Methodology: Four cadavers were selected based on thickness of flexor tendons and general composition; one cadaver was excluded due to inadequacy of tendon durability. The flexor digitorum superficialis and profundus of digits 2,3, and 4 were tested for strength at 0 and 15 degrees, before and after cutting of the flexor retinaculum. Strength was replicated by loading of the tendons with 2,4, and 6kg weights and measuring the voltage output on a Single Tract pressure sensor. Results: Over 60 points of data were collected across the four cadavers; however, a significance in pre- and post-retinaculum release trials was only achieved in the superficialis muscle of the 4th digit at a 4kg and 6 kg weight. The remaining results displayed no significant pattern or trend in regard to pre and post release strength. Conclusion: The evidence gathered in this experiment does not allow us to make an accurate conclusion due to its equivocal nature. Recommendation is for further testing to increase the data size, expansion to include soft cure cadavers, improve replication/isolation of mimicking the carpal tunnel release surgery, and reduce variability in the data collection. In evaluation of surgical treatment of CTS, our recommendation currently is to follow current surgical guidelines

Interactive effects of climate change and fungal communities on wood-derived carbon in forest soils

Although wood makes up the majority of forest biomass, the importance of wood contributions to stable soil carbon (C) pools is uncertain. Complex interactions among climate, soil physical properties, intrinsic properties of woody residues, and biological processes all exert dynamic controls over the stabilization, destabilization and transport of wood-derived C in soils. Many studies have demonstrated the strong physical controls on decomposition rates in soils, but little work has been done to relate these to changes in decomposer community composition and how this influences the fate of wood-derived C in soils. Here, we examine the effects of initial fungal inoculation, temperature, soil texture, Free Air CO2 Enrichment (FACE) wood type, and location of wood residue in the soil, with an experiment investigating the fate of wood-derived C from soils in the first two years following clear-cut harvest in aspen (Populus tremuloides Michx.) forests. We applied 13C-depleted aspen wood chips in 168 experimental plots across six sites in northern Michigan, USA, and tracked the depleted 13C signature through the mineral soil as DOC and from the soil surface as CO2. Wood residue location had the largest impact on soil CO2 efflux, with surface wood treatments having more than twice as much wood-derived soil CO2 efflux as buried wood treatments (1.20 g CO2 m−2 h−1 versus 0.49 g CO2 m−2 h−1, respectively; p \u3c 0.001). Initial fungal decomposers had a significant effect on DOC quantity and quality, with higher wood-derived DOC concentrations, levels of humification, and tannin content for white-rot treatments compared with brown-rot treatments. Buried chip treatments within open-top chambers had one-third higher wood-derived soil CO2 efflux than buried chips in ambient temperature treatments (p \u3c 0.002). FACE wood type also influenced soil C fluxes from the decomposing wood chips. The average wood-derived soil CO2 efflux and the average percentage of wood-derived soil CO2 efflux were significantly greater from wood grown under elevated CO2 than wood grown under elevated CO2 + O3 (p = 0.002 and p = 0.004, respectively). Furthermore, wood grown under elevated CO2 had increased DOC aromaticity relative to wood grown in ambient conditions. Taken together, these results show that wood-derived C sources and the decomposers that process them are significant determinants of C fluxes from and transformations within the soil following harvest in aspen forests

EKU R User Group

The Eastern Kentucky University R user group meets the last Thursday of every month during the Fall and Spring semesters. Everyone is welcome to join the group and attend the monthly meetings. Our purpose is to build a community of people interested in using the programming language R. The goal is to exchange ideas, collaborate, and provide support to one another. Participants at all levels of experience are welcome