768 research outputs found
Rubble Pile Characterization Model
Rubble piles created following the collapse of a building in a combat situation can significantly impact mission accomplishment, particularly in the area of movement and maneuver. Rubble characteristics must be known, for example, in order to predict the ability of a vehicle to override the collateral damage from weapon effects in urban areas. Two types of models are developed: a first-order model and a first-principles-based model. In both models, we assume complete rubblization of the building and develop a rubble profile model using the size and composition of the collapsed structure to predict the rubble volume. In both cases, this profile model includes the size of the footprint area surrounding the original building assuming that the rubble is free to expand horizontally as well as the resulting height of such a rubble pile. Empirical data is now needed to verify the predictive capabilities of these models
Patterns and rates of exonic de novo mutations in autism spectrum disorders
Autism spectrum disorders (ASD) are believed to have genetic and environmental origins, yet in only a modest fraction of individuals can specific causes be identified1,2. To identify further genetic risk factors, we assess the role of de novo mutations in ASD by sequencing the exomes of ASD cases and their parents (n= 175 trios). Fewer than half of the cases (46.3%) carry a missense or nonsense de novo variant and the overall rate of mutation is only modestly higher than the expected rate. In contrast, there is significantly enriched connectivity among the proteins encoded by genes harboring de novo missense or nonsense mutations, and excess connectivity to prior ASD genes of major effect, suggesting a subset of observed events are relevant to ASD risk. The small increase in rate of de novo events, when taken together with the connections among the proteins themselves and to ASD, are consistent with an important but limited role for de novo point mutations, similar to that documented for de novo copy number variants. Genetic models incorporating these data suggest that the majority of observed de novo events are unconnected to ASD, those that do confer risk are distributed across many genes and are incompletely penetrant (i.e., not necessarily causal). Our results support polygenic models in which spontaneous coding mutations in any of a large number of genes increases risk by 5 to 20-fold. Despite the challenge posed by such models, results from de novo events and a large parallel case-control study provide strong evidence in favor of CHD8 and KATNAL2 as genuine autism risk factors
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 .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the 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
Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo
Meeting Abstracts: Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo Clearwater Beach, FL, USA. 9-11 June 201
030 - Braden Dale Beckstrom
The large range of reported values of life-cycle assessments (LCA) and techno-economic assessments (TEA) in the algal biofuels research field is concerning. This wide range of results creates difficulties when attempting to directly compare different processes and technologies across publications. This project attempts to rectify this difficulty by unifying the diverse methods of reporting results within this research sector. A harmonization of life-cycle assessments was completed for 20 published journal articles. Harmonization included the standardization of units to MJ/kg algae for Net Energy Ratio (NER) and gCO2-eq/kg algae for Global Warming Potential (GWP), results to a growth rate of 25 g/m2/day, and a Well-to-wheels (WTW) system boundary. Implementation of these standardized assumptions and system metrics produced a significant decrease in the range of reported values for both the NER (the energy input required to produce 1 MJ of fuel output) and GWP (g CO2-equivalent / MJfuel). Similarly, 22 models were developed from 9 publications and harmonized by TEA methodology and growth rates, using the standard assumptions from the Bioenergy Technologies Office (BETO). A second TEA harmonization examining only downstream conversion technologies was performed by standardizing the cost of algal biomass. TEA results suggest that future economic modeling efforts should include a BETO assumptions baseline case for better comparisons to other published work. Additionally, a productivity of 25 g/m2/day is a suitable baseline yield for analysis, as higher productivities result in diminishing returns for TEA results, but lower productivities skew the results significantly. Finally, harmonizing algal biomass cost for input into downstream conversion technology evaluations allows for more effective cross-technology comparisons by significantly reducing the range of results. Harmonization work like this effort can help more effectively determine which production pathways and technologies have the best future potential
International Governance of Autonomous Military Robots
New technologies have always been a critical component of military strategy and preparedness. One new technology on the not-too-distant technological horizon is lethal autonomous robotics, which would consist of robotic weapons capable of exerting lethal force without human control or intervention. There are a number of operational and tactical factors that create incentives for the development of such lethal systems as the next step in the current development, deployment and use of autonomous systems in military forces. Yet, such robotic systems would raise a number of potential operational, policy, ethical and legal issues. This article summarizes the current status and incentives for the development of lethal autonomous robots, discusses some of the issues that would be raised by such systems, and calls for a national and international dialogue on appropriate governance of such systems before they are deployed. The article reviews potential modes of governance, ranging from ethical principles implemented through modifications or refinements of national policies, to changes in the law of war and rules of engagement, to international treaties or agreements, or to a variety of other “soft law” governance mechanisms
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