A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

In support of NASAs ongoing effort to bring supersonic commercial travel to the public, NASA Dryden Flight Research Center and NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response. Such tests will go towards building a dataset that governing agencies like the Federal Aviation Administration and International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. Until WSPR, there had never been an effort that studied the response of people in their own homes and performing daily activities to non-traditional, low sonic booms.WSPR was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle. Other partners included Gulfstream Aerospace Corporation, Pennsylvania State University, Tetra Tech, and Fidell Associates, Inc.A major objective of the effort included exposing a community with the sonic boom magnitudes and occurrences expected in high-air traffic regions with a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data was collected using multiple survey methods. The research focused on essential elements of community response testing including subject recruitment, survey methods, instrumentation systems, flight planning and operations, and data analysis methods.This paper focuses on NASAs role in the efforts logistics and operations including human response subject recruitment, the operational processes involved in implementing the surveys throughout the community, instrumentation systems, logistics, flight planning, and flight operations. Findings discussed in this paper include critical lessons learned in all of those areas. The paper also discusses flight operations results. Analysis of the accuracy and repeatability of planning and executing the unique aircraft maneuver used to generate low sonic booms concluded that the sonic booms had overpressures within 0.15 pounds-per-square-feet of the planned values for 76 of t he attempts. Similarly, 90 of the attempts to generate low sonic booms within the community were successful

Association of CD99 short and long forms with MHC class I, MHC class II and tetraspanin CD81 and recruitment into immunological synapses

<p>Abstract</p> <p>Background</p> <p>CD99, a leukocyte surface glycoprotein, is broadly expressed in many cell types. On the cell surface, CD99 is expressed as two distinct isoforms, a long form and a short form. CD99 has been demonstrated to play a key role in several biological processes, including the regulation of T cell activation. However, the molecular mechanisms by which CD99 participates in such processes are unclear. As CD99 contains a short cytoplasmic tail, it is unlikely that CD99 itself takes part in its multi-functions. Association of CD99 with other membrane proteins has been suggested to be necessary for exerting its functions.</p> <p>Results</p> <p>In this study, we analyzed the association of CD99 with other cell surface molecules involved in T cell activation. We demonstrate the association of MHC class I, MHC class II and tetraspanin CD81 with CD99 molecules on the cell surface. Association of CD99 with its partners was observed for both isoforms. In addition, we determined that CD99 is a lipid raft-associated membrane protein and is recruited into the immunologic synapse during T cell activation. The implication of CD99 on T cell activation was investigated. Inhibition of anti-CD3 induced T cell proliferation by an anti-CD99 monoclonal antibody was observed.</p> <p>Conclusions</p> <p>We provide evidence that CD99 directly interact and form the complex with the MHC class I and II, and tetraspanin CD81, and is functionally linked to the formation of the immunologic synapse. Upon T cell activation, CD99 engagement can inhibit T cell proliferation. We speculate that the CD99-MHC-CD81 complex is a tetraspanin web that plays an important role in T cell activation.</p

One, two, three phytoliths: assessing the minimum phytolith sum for archaeological studies

The number of phytolith studies has increased steadily in the last decades in palaeoecological as well as archaeological research, and phytolith analysis is currently recognised as a proper area of expertise within archaeobotany. This has led towards a strengthening in the standardisation of the different steps involved in analysis; e.g. sampling strategies, laboratory extraction or processing of plant material/soils for the creation of reference collections. In spite of this, counting procedures remain one of the areas that could be further developed. The aim of this paper is to assess representativeness of phytolith count size in archaeological samples and specifically to assess whether an increase in total number of individuals counted influences the number or distribution of morphotypes observed. Two statistical tests are performed to evaluate the representativeness of count size: phytolith sum variability analysis (PSVA) and morphotype accumulation curve (MAC). The analyses show the relationship among the number of counted phytoliths, the variability (that is, the number of different morphotypes identified) and the stabilisations of the MACs. Results allow us to support the standard count size in phytolith studies, which ranges from 250 to 300 particles. Together with a quick scan, this strategy should produce a precise and clear phytolith assemblage for archaeological studies.The author would like to acknowledge the directors of both sites El Mirón (L. Straus and M. González Morales) and La Bauma del Serrat del Pont (M. Saña and G. Alcalde) for their essential collaboration as well as to J. Elvira (Institute of Soil Science, Spanish National Research Council ICTJA-CSIC) for running the X-ray diffraction analyses.Peer reviewe