A short course in lunar geology for earth science instructors

A four-day short course in lunar geology was developed, leading to the publication of a primer in lunar geology. The course was offered to 22 sponsored participants (community college teachers) and to representatives from the Lunar Science Institute, Houston, Texas, and from the Educational Program Office of NASA-Ames, on April 25-28, 1974. A follow-up survey of the course participants was made in two steps: on the last day of the course, and one year later. In general, the participants felt that the course was well organized and that the speakers were effective. Most of the participants introduced some aspects of what they learned into their own teaching material. Finally, a well-panel display about 7 1/2 feet high and 16 feet long designed to acquaint the viewer with elementary facts of lunar geology was constructed and permanently installed at the Space Science Center of Foothill College

Application of the CINGEN program a thermal network data generator

The application of the CINGEN computer program and two of its supporting programs for the evaluation of structural and thermal performance of physical systems was described. The CINGEN program was written and implemented to avoid the duplication effort of performing a finite element approach for structural analysis and a finite differencing technique for thermal analysis, as well as the desire for a geometrical representation of the thermal model to reduce modeling errors. The program simplifies the thermal modeling process by performing all of the capacitance and conductance calculations normally done by the analyst. Each solid element is divided into five tetrahedrons, allowing the total volume to be calculated precisely. A sample problem was illustrated

Reframing Agribusiness: Moving from Farm to Market Centric

Agribusiness is moving from farm to market centric, where effective activities anticipate and respond to customers, markets, and the systems in which they function. This evolution requires a broader conceptualization and more accurate definition, to convey a more dynamic, systemic, and integrative discipline, which increasingly is committed to value creation and the sustainable orchestration of food, fiber, and renewable resources. We discuss the forces driving this shift to the market, offer a new and more representative definition of agribusiness, provide models to illustrate some of the most compelling trends, and articulate key elements and implications of those models.agribusiness definition, conceptual models, market centric, market systems, Agribusiness, Marketing, Production Economics,

The Mutual Interpretation of Active and Passive Microwave Sensor Outputs

Mutual interpretation of active and passive microwave sensor output

Coupled feedback loops maintain synaptic long-term potentiation: A computational model of PKMzeta synthesis and AMPA receptor trafficking

In long-term potentiation (LTP), one of the most studied types of neural plasticity, synaptic strength is persistently increased in response to stimulation. Although a number of different proteins have been implicated in the sub-cellular molecular processes underlying induction and maintenance of LTP, the precise mechanisms remain unknown. A particular challenge is to demonstrate that a proposed molecular mechanism can provide the level of stability needed to maintain memories for months or longer, in spite of the fact that many of the participating molecules have much shorter life spans. Here we present a computational model that combines simulations of several biochemical reactions that have been suggested in the LTP literature and show that the resulting system does exhibit the required stability. At the core of the model are two interlinked feedback loops of molecular reactions, one involving the atypical protein kinase PKM{\zeta} and its messenger RNA, the other involving PKM{\zeta} and GluA2-containing AMPA receptors. We demonstrate that robust bistability - stable equilibria both in the synapse's potentiated and unpotentiated states - can arise from a set of simple molecular reactions. The model is able to account for a wide range of empirical results, including induction and maintenance of late-phase LTP, cellular memory reconsolidation and the effects of different pharmaceutical interventions