15,152 research outputs found
Project for the analysis of technology transfer Quarterly evaluation report, 1 Jan. - 31 Mar. 1969
Technology transfer analysis project studying nonspace applications of NASA and AEC generated technolog
Project for the analysis of technology transfer Quarterly report, 13 Jul. - 12 Oct. 1968
Statistical characteristics of transfer data bank users, and outline of technology transfer and utilization instruction cours
Gypsy moths and American dog ticks: Space partners
An experiment intended for the space shuttle and designed to investigate the effects of weightlessness and total darkness on gypsy moth eggs and engorged American dog ticks is described. The objectives are: (1) to reevaluate the effects of zero gravity on the termination of diapause/hibernation of embryonated gypsy moth eggs, (2) to determine the effect of zero gravity on the ovipositions and subsequent hatch from engorged female American dog ticks that have been induced to diapause in the laboratory, and (3) to determine whether morphological or biochemical changes occur in the insects under examination. Results will be compared with those from a similar experiment conducted on Skylab 4
Sequential primed kinases create a damage-responsive phosphodegron on Eco1.
Sister-chromatid cohesion is established during S phase when Eco1 acetylates cohesin. In budding yeast, Eco1 activity falls after S phase due to Cdk1-dependent phosphorylation, which triggers ubiquitination by SCF(Cdc4). We show here that Eco1 degradation requires the sequential actions of Cdk1 and two additional kinases, Cdc7-Dbf4 and the GSK-3 homolog Mck1. These kinases recognize motifs primed by previous phosphorylation, resulting in an ordered sequence of three phosphorylation events on Eco1. Only the latter two phosphorylation sites are spaced correctly to bind Cdc4, resulting in strict discrimination between phosphates added by Cdk1 and by Cdc7. Inhibition of Cdc7 by the DNA damage response prevents Eco1 destruction, allowing establishment of cohesion after S phase. This elaborate regulatory system, involving three independent kinases and stringent substrate selection by a ubiquitin ligase, enables robust control of cohesion establishment during normal growth and after stress
The Welfare Effects of Pfiesteria-Related Fish Kills in Seafood Markets: A Contingent Behavior Analysis
We use contingent behavior analysis to study the effects of Pfiesteria related fish kills on the demand for seafood in the Mid-Atlantic region. We use a phone-mail-phone survey to look at the effects of various information provision mechanisms used to ameliorate the effects of misinformation regarding fish kills. A set of demand difference models are estimated based on individual responses to multiple questions about seafood consumption with and without fish kills present and with various health risk information treatments. Random effects Tobit models are used to control for the panel nature of responses and natural censoring of the stated responses. We find that 1) Pfiesteria related fish kills have a significant negative effect on the demand for seafood, 2) seafood consumers are nonresponsive to expert risk information designed to reassure consumers that seafood is safe in the presence of a fish kill, and 3) a mandatory seafood inspection program completely eliminates avoidance costs incurred due to misinformation. We estimate that the aggregate avoidance costs incurred in the month immediately following a Pfiesteria related fish kill is 130 million.
Project for the analysis of technology transfer Quarterly evaluation report, 13 Oct. - 12 Dec. 1968
Technical support package usage documentation by technology transfer analysis projec
Impact of Seawall Type on Mollusc Size and Diversity in South Water Caye Belize: A Case Study
The size and diversity of molluscs on and in front of artificial and natural sea walls in the tropical rocky intertidal of South Water Caye, Belize were investigated with the intent of determining the suitability of artificial surfaces to replace natural seawalls. Four seawalls, three artificial and one natural, were observed over a period of eight days. Mollusc size did not change based on distance from the wall for any of the walls. However, there were some significant differences in the species and number of molluscs in front of each wall as well as on the walls themselves. Measures of species richness, the Shannon diversity index and Jaccardās index indicated that the natural wall species assemblage was quite different from that of the artificial walls. For the different types of artificial walls, it was clear that wall structure and age play a role in the number and diversity of molluscs on each wall. This case study has thus revealed that greater attention needs to be dedicated to the architecture and engineering of artificial seawalls in order to minimize their impact on the diversity of molluscs in the marine ecosystem
Using schedulers to test probabilistic distributed systems
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s00165-012-0244-5. Copyright Ā© 2012, British Computer Society.Formal methods are one of the most important approaches to increasing the confidence in the correctness of software systems. A formal specification can be used as an oracle in testing since one can determine whether an observed behaviour is allowed by the specification. This is an important feature of formal testing: behaviours of the system observed in testing are compared with the specification and ideally this comparison is automated. In this paper we study a formal testing framework to deal with systems that interact with their environment at physically distributed interfaces, called ports, and where choices between different possibilities are probabilistically quantified. Building on previous work, we introduce two families of schedulers to resolve nondeterministic choices among different actions of the system. The first type of schedulers, which we call global schedulers, resolves nondeterministic choices by representing the environment as a single global scheduler. The second type, which we call localised schedulers, models the environment as a set of schedulers with there being one scheduler for each port. We formally define the application of schedulers to systems and provide and study different implementation relations in this setting
Use of Gas Electron Multiplier (GEM) Detectors for an Advanced X-ray Monitor
We describe a concept for a NASA SMEX Mission in which Gas Electron
Multiplier (GEM) detectors, developed at CERN, are adapted for use in X-ray
astronomy. These detectors can be used to obtain moderately large detector area
and two-dimensional photon positions with sub mm accuracy in the range of 1.5
to 15 keV. We describe an application of GEMs with xenon gas, coded mask
cameras, and simple circuits for measuring event positions and for
anticoincidence rejection of particle events. The cameras are arranged to cover
most of the celestial sphere, providing high sensitivity and throughput for a
wide variety of cosmic explosions. At longer timescales, persistent X-ray
sources would be monitored with unprecedented levels of coverage. The
sensitivity to faint X-ray sources on a one-day timescale would be improved by
a factor of 6 over the capability of the RXTE All Sky Monitor.Comment: 10 pages, 5 figs., in X-Ray and Gamma Ray Instrumentation for
Astronomy XI, SPIE conference, San Diego, Aug. 200
Project for the analysis of technology transfer Quarterly report, 1 Apr. 1969 - 30 Jun. 1969
Patterns, statistical analyses, and case studies of transfer and utilization of NASA generated technolog
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