How well do we know the Martian abundances of highly volatile elements

The table is given that summarizes four models based on observations and gives some reasonable inferences of each for Martian volatiles. The table columns give: (1) the volatile assumptions of the model; (2) the inferred Martian volatile concentrations relative to earth; (3) the N/36 Ar and C/36 Ar ratios; (4) the percentage of Martian degassing inferred by the model, and 5 and 6) the equivalent global column heights of liquid water and solid CaCO3 over the entire surface of Mars that would be formed from the model quantities of degassed volatiles

Ar-39-Ar-40 of achondrites: Evidence for a lunar-like cataclysm

The observation that the K-Ar, Pb-Pb, and Rb-Sr ages of a significant number of lunar highland rocks were reset in the interval of 4.1-3.8 Ga ago led to the concept of a cataclysmic bombardment of the moon during this period. An important consideration for understanding the early bombardment history of the solar system, including the moon, is whether evidence also exists in meteorites for resetting of radiometric ages by cataclysmic bombardment of their parent bodies. A comparison of Ar-39-Ar-40 ages of achondritic meteorites with ages of lunar highland rocks should help elucidate the nature of the early bombardment of the solar system. We are participating in various consortia studies of primarily Antarctic eucrites and howardites for which we measured Ar-39-Ar-40 ages of various clasts and matrix samples. The results of these studies are presented

Sustainable Agriculture Bibliography

An annotated bibliography related to the sustainability of biotechnology and pharmaceutical technologies used in modern agriculture

Monopoly, Regulation, and Innovation

Recently the Justice department has started investigations into alleged anti-trust violations by Monsanto. This has helped fuel a lot of already hyped discontent with one of the world’s leaders in innovative solutions for sustainable agriculture. This article discusses how the regulatory environment could possibly have contributed to more concentration and power in the biotech industry. Increasing regulation would likely have the opposite effect of creating a level playing field in the agriculture industry. From AgWeb, March 27,2010 http://www.agweb.com/blog/Economic_Sense_190/Monopoly_Regulation__and_Innovation_10771

Why Study Applied/Agricultural Economics

Agricultural Economics is a very applied field covering many topics beyond those stereotypically thought of as pertaining to agriculture. These may include finance and risk management, environmental and natural resource economics, game theory, or public policy analysis to name a few

Mathematical Themes in Economics, Machine Learning, and Bioinformatics

Graduate students in economics are often introduced to some very useful mathematical tools that many outside the discipline may not associate with training in economics. This essay looks at some of these tools and concepts, including constrained optimization, separating hyperplanes, supporting hyperplanes, and ‘duality.’ Applications of these tools are explored including topics from machine learning and bioinformatics

Autour d'une mosaïque médiévale de la Grande Mosquée de Damas

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Empirical Methods for Predicting Student Retention- A Summary from the Literature

The vast majority of the literature related to the empirical estimation of retention models includes a discussion of the theoretical retention framework established by Bean, Braxton, Tinto, Pascarella, Terenzini and others (see Bean, 1980; Bean, 2000; Braxton, 2000; Braxton et al, 2004; Chapman and Pascarella, 1983; Pascarell and Ternzini, 1978; St. John and Cabrera, 2000; Tinto, 1975) This body of research provides a starting point for the consideration of which explanatory variables to include in any model specification, as well as identifying possible data sources. The literature separates itself into two major camps including research related to the hypothesis testing and the confirmation or empirical validation of theoretical retention models (Herzog, 2005; Ronco and Cahill, 2006; Stratton et al 2008) vs. research specifically focused on the development of applied predictive models (Miller, 2007; Miller & Herreid, 2008; Herzog, 2006; Dey & Astin, 1993; Delen 2010; Yu et al, 2010). Literature indicates that data mining or algorithmic approaches to prediction can provide superior results vis-à-vis traditional statistical modeling approaches (Delen et al, 2004; Sharda and Delen, 2006; Delen et al, 2007; Kiang 2007; Li et al 2009). However, little research in higher education has focused on the employment of data mining methods for predicting retention (Herzog, 2006)

Using R

R is a statistical programming language with a command line interface that is becoming more and more popular every day. I have used R for data visualization, data mining/machine learning, as well as social network analysis. Initially embraced largely in academia, R is becoming the software of choice in various corporate settings

Designerly Ways of Reading: Insights From Reader Response in Drama for Enriching the A in Language Arts

In this interpretive case study of reader response in drama, a drama troupe is the context for illuminating how young actors read in designerly ways; that is, how their reading processes facilitated constructive, solution-focused thinking in their development of characterizations. By examining the nature of reader response in the drama troupe, I hope to help educators understand how design thinking occurred as an aesthetic reading practice and consider ways in which design thinking can be cultivated in the language arts classroom. I argue that design thinking inspires the young to engage the imagination, practice teamwork, and take risks as they work to make their visions real. Perhaps most importantly, I contend that design thinking can help prepare the young for facing complex and highly ambiguous problems characteristic of 21st century participatory cultures