NASA Marshall Impact Testing Facility Capabilities Applicable to Lunar Dust Work

The Impact Testing Facility at Marshall Space Flight Center has several guns that would be of use in studying impact phenomena with respect to lunar dust. These include both ballistic guns, using compressed gas and powder charges, and hypervelocity guns, either light gas guns or an exploding wire gun. In addition, a plasma drag accelerator expected to reach 20 km/s for small particles is under development. Velocity determination and impact event recording are done using ultra-high-speed cameras. Simulation analysis is also available using the SPHC hydrocode

Thirty-eight years of CO<sub>2</sub> fertilization has outpaced growing aridity to drive greening of Australian woody ecosystems

Climate change is projected to increase the imbalance between the supply (precipitation) and atmospheric demand for water (i.e., increased potential evapotranspiration), stressing plants in water-limited environments. Plants may be able to offset increasing aridity because rising CO2 increases water use efficiency. CO2 fertilization has also been cited as one of the drivers of the widespread "greening" phenomenon. However, attributing the size of this CO2 fertilization effect is complicated, due in part to a lack of long-term vegetation monitoring and interannual- to decadalscale climate variability. In this study we asked the question of how much CO2 has contributed towards greening. We focused our analysis on a broad aridity gradient spanning eastern Australia's woody ecosystems. Next we analyzed 38 years of satellite remote sensing estimates of vegetation greenness (normalized difference vegetation index, NDVI) to examine the role of CO2 in ameliorating climate change impacts. Multiple statistical techniques were applied to separate the CO2-attributable effects on greening from the changes in water supply and atmospheric aridity. Widespread vegetation greening occurred despite a warming climate, increases in vapor pressure deficit, and repeated record-breaking droughts and heat waves. Between 1982-2019 we found that NDVI increased (median 11.3 %) across 90.5 % of the woody regions. After masking disturbance effects (e.g., fire), we statistically estimated an 11.7 % increase in NDVI attributable to CO2, broadly consistent with a hypothesized theoretical expectation of an 8.6 % increase in water use efficiency due to rising CO2. In contrast to reports of a weakening CO2 fertilization effect, we found no consistent temporal change in the CO2 effect. We conclude rising CO2 has mitigated the effects of increasing aridity, repeated record-breaking droughts, and record-breaking heat waves in eastern Australia. However, we were unable to determine whether trees or grasses were the primary beneficiary of the CO2-induced change in water use efficiency, which has implications for projecting future ecosystem resilience. A more complete understanding of how CO2-induced changes in water use efficiency affect trees and non-tree vegetation is needed

Palaeomagnetic and synchrotron analysis of \u3e1.95 Ma fossil-bearing palaeokarst at Haasgat, South Africa

Palaeomagnetic analysis indicates that Haasgat, a fossil-bearing palaeocave in the Gauteng Province of South Africa, is dominated by reversed magnetic polarity in its oldest, deepest layers and normal polarity in the younger layers. The presence of in-situ Equus specimens suggests an age of less than ~2.3 Ma, while morphological analysis of faunal specimens from the ex-situ assemblage suggests an age greater than 1.8 Ma. Given this faunal age constraint, the older reversed polarity sections most likely date to the beginning of the Matuyama Chron (2.58–1.95 Ma), while the younger normal polarity deposits likely date to the very beginning of the Olduvai Sub-Chron (1.95–1.78 Ma). The occurrence of a magnetic reversal from reversed to normal polarity recorded in the sequence indicates the deposits of the Bridge Section date to ~1.95 Ma. All the in-situ fossil deposits that have been noted are older than the 1.95 Ma reversal, but younger than 2.3 Ma. Haasgat therefore dates to an interesting time period in South African human evolution that saw the last occurrence of two australopith species at ~2.05–2.02 Ma (Sts5 Australopithecus africanus from Sterkfontein Member 4) to ~1.98 Ma ( Australopithecus sediba from Malapa) and the first occurrence of early Homo (Sk847), Paranthropus and the Oldowan within Swartkrans Member 1 between ~2.0 Ma and ~1.8 Ma

NASA 26 GHz Polar Subnet in 2020+

The next generation Earth observing satellites will face challenges in supporting high rate space communications from the increasingly sophisticated instruments. Emerging applications will need space-to-ground links with data rates forecasted to be in the 1-20 Gbps range. To meet these challenges, NASA is designing and integrating a 26 GHz Polar Subnet to support space communication needs in 2020 and beyond. This paper describes the current effort of the Space Communications and Navigation Program's Near Earth Network (NEN), managed out of Goddard Space Flight Facility (GSFC), to deploy a 26 GHz Polar Subnet including the implementation, topology, capabilities, architecture design, operations and key design trades

Rapid and accurate broadband absorption cross-section measurement of human bodies in a reverberation chamber

A measurement methodology for polarization and angle of incidence averaged electromagnetic absorption cross-section using a reverberation chamber is presented. The method is optimized for simultaneous rapid and accurate determination of average absorption cross-section over the frequency range 1–15 GHz, making it suitable for use in human absorption and exposure studies. The typical measurement time of the subject is about 8 min with a corresponding statistical uncertainty of about 3% in the measured absorption cross-section. The method is validated by comparing measurements on a spherical phantom with Mie series calculations. The efficacy of the method is demonstrated with measurements of the posture dependence of the absorption cross-section of a human subject and an investigation of the effects of clothing on the measured absorption which are important considerations for the practical design of experiments for studies on human subjects

Abstracts

The following publications are abstracts by the mentionned authors;A Preliminary Study of an attempt to Introduce PGCE D&T Students to Designing and the Teaching of Designing in the Secondary School - Abstract by David Barlex and Marion RutlandRemembering the C in D&T: Gendered Perceptions of Creativity and Design & Technology - Abstract by David SpendloveInnovation in Design and Technology: the Polymer Acoustic Guitar and the Case for Relegation of 'The Design Process' - Abstract by Dr Eddie NormanThe Introduction of Practical Craft Skills into the Scottish Technology Curriculum: A New Beginning or the Beginning of the End - Abstract by John DakersMaking Progress? A Discussion of the Concept of Progress in Relation to Design and Technology Education - Abstract by Steve KeirlGlobalisation of the Go: Implications for Design and Technology Education @ 2003 - Abstract by Steve KeirlThe Wow Factor - Textiles gets a Boost with CAD in the UK and Australia - Abstract by Rose Sinclair and Louise DuvernetInteraction, Dialogue and a Creative Spirit of Inquiry - Abstract by J. W. HamiltonTechnology Students' Views of Intelligence and the Implications for Classroom Practice - Abstract by Wendy J. DowIs there a Core of D&T Knowledge? - Abstract by Tim LewisDeyond Pro/DESKTOP Computer Aided Design (CAD): the Transfer of CAD-based Design Modelling Skills from Schools to Higher Education - Abstract by Tony Hodgson and Clare Allsop'It aint what you do it's the way that you do it' - Abstract by Tony Lawler and Martin HowlettThe Presentation of Systems Thinking in Support Materials for Secondary Design & Technology Pupils: A Review - Abstract by Torben SteegValuing Progression in Design and Technology Education - Abstract by Mike MartinElectronic Portfolios for Design and Technology. What if...? - Abstract by Andy MitchellGifted and Talented Pupils in Design and Technology at Key Stage Three - Abstract by Christine Arthingto

Risk algorithm using serial biomarker measurements doubles the number of screen-detected cancers compared with a single-threshold rule in the United Kingdom collaborative trial of ovarian cancer screening

PURPOSE: Cancer screening strategies have commonly adopted single-biomarker thresholds to identify abnormality. We investigated the impact of serial biomarker change interpreted through a risk algorithm on cancer detection rates. PATIENTS AND METHODS: In the United Kingdom Collaborative Trial of Ovarian Cancer Screening, 46,237 women, age 50 years or older underwent incidence screening by using the multimodal strategy (MMS) in which annual serum cancer antigen 125 (CA-125) was interpreted with the risk of ovarian cancer algorithm (ROCA). Women were triaged by the ROCA: normal risk, returned to annual screening; intermediate risk, repeat CA-125; and elevated risk, repeat CA-125 and transvaginal ultrasound. Women with persistently increased risk were clinically evaluated. All participants were followed through national cancer and/or death registries. Performance characteristics of a single-threshold rule and the ROCA were compared by using receiver operating characteristic curves. RESULTS: After 296,911 women-years of annual incidence screening, 640 women underwent surgery. Of those, 133 had primary invasive epithelial ovarian or tubal cancers (iEOCs). In all, 22 interval iEOCs occurred within 1 year of screening, of which one was detected by ROCA but was managed conservatively after clinical assessment. The sensitivity and specificity of MMS for detection of iEOCs were 85.8% (95% CI, 79.3% to 90.9%) and 99.8% (95% CI, 99.8% to 99.8%), respectively, with 4.8 surgeries per iEOC. ROCA alone detected 87.1% (135 of 155) of the iEOCs. Using fixed CA-125 cutoffs at the last annual screen of more than 35, more than 30, and more than 22 U/mL would have identified 41.3% (64 of 155), 48.4% (75 of 155), and 66.5% (103 of 155), respectively. The area under the curve for ROCA (0.915) was significantly (P = .0027) higher than that for a single-threshold rule (0.869). CONCLUSION: Screening by using ROCA doubled the number of screen-detected iEOCs compared with a fixed cutoff. In the context of cancer screening, reliance on predefined single-threshold rules may result in biomarkers of value being discarded