Internal and External Fluctuation Activated Non-equilibrium Reactive Rate Process

The activated rate process for non-equilibrium open systems is studied taking into account both internal and external noise fluctuations in a unified way. The probability of a particle diffusing passing over the saddle point and the rate constant together with the effective transmission coefficient are calculated via the method of reactive flux. We find that the complexity of internal noise is always harmful to the diffusion of particles. However the external modulation may be beneficial to the rate process.Comment: 10 pages, 1 figure (containing 2 subgraphs). arXiv admin note: text overlap with arXiv:cond-mat/9911028 by other author

The Diverse Structure and Organization of U.S. Beef Cow-Calf Farms

Beef cow-calf production in the United States is widespread, occurring in every State. Nearly 765,000 farms, about 35 percent of the 2.2 million farms in the United States, had a beef cow inventory in 2007. Most of these were small, part-time operations. About a third of farms that raise beef animals had a beef cow inventory of less than 10 cows, more than half had fewer than 20 cows, and nearly 80 percent had fewer than 50 cows. In this study, ERS uses data from USDA’s 2008 Agricultural Resource Management Survey for U.S. beef cow-calf operations to examine the structure, costs, and characteristics of beef cow-calf producers. Many small operations are “rural residence farms” that specialize in beef cow-calf production, but their income from off-farm sources exceeds that from the farm. Most beef cow-calf production occurs on large farms, but cow-calf production is not the primary enterprise on many of these farms. Findings suggest that operators of beef cow-calf farms have a diverse set of goals for the cattle enterprise.Beef cow-calf production, farm income, animal traceability, Agricultural Resource Management Survey (ARMS), National Animal Identification System (NAIS), Agribusiness, Agricultural and Food Policy, Farm Management, Livestock Production/Industries,

Beef Cow-Calf Producer Participation in the National Animal Identification System

Farm Management, Livestock Production/Industries, Production Economics,

Ice Sheets and Ice Streams: Thoughts on the Cordilleran Ice Sheet Symposium

This paper comments on preconceptions about what is meant by the terms "Cordilleran Ice Sheet" and "ice stream". Contemporary Antarctic ice streams are described. The Laurentian Channel and throughs crossing the continental ice shelf between Vancouver and Queens Charlotte Islands are suggested as candidates for the tracks of past ice streams.On discute ici de préconceptions sur la signification des termes « Inlandsis de la Cordillère » et « courant glaciaire ». On décrit d'abord les courants glaciaires contemporains de l'Antarctique. On désigne ensuite le chenal laurentien et les dépressions qui traversent le plateau continental entre Vancouver et l'archipel de la Reine-Charlotte comme des endroits susceptibles d'avoir été, dans le passé, la voie de courants glaciaires

Derived Demand for Cattle Feeding Inputs

Derived demand relationships among four weight categories of feeder cattle entering Texas feedlots and feed were examined using a Generalized McFadden dual cost function specified as an error correction model. Relationships among own- and cross-price elasticities provide evidence for at least two cattle feeding enterprises, feeding lightweight feeder cattle (calves) and feeding heavier cattle. These results indicate systematic differences in demand relationships among the different weight classes, providing explanation and insight into mixed results from earlier studies. Seasonality differed across weight categories, providing additional support for multiple cattle feeding enterprises. A third step was added to the Engle-Granger two-step estimation procedure to incorporate information provided in the second step.Research Methods/ Statistical Methods,

Derived Demand for Cattle Feeding Inputs

Derived demand relationships among four weight categories of feeder cattle entering Texas feedlots and their feed consumed are examined using a generalized McFadden dual cost function. Results demonstrate systematic differences in demand relationships among different weight categories. Positive cross-price elasticities among the three heaviest weight categories are consistent with input substitution among weight categories and consistent with objective functions associated with optimal placement weight. Anomalies in the form of negative cross-price elasticities between weight categories provide evidence for an alternative objective function associated with longer term feeding of light-weight feeder cattle. Results also demonstrate seasonality differences across weight categories.cattle feeding, derived demand, elasticity, feeder cattle, generalized McFadden cost function, Agribusiness, Demand and Price Analysis, Livestock Production/Industries,

The Development of the WISE (Writing to Inspire Successful Education) Writing Mentoring Program: A University-School Collaboration

Abstract This paper describes the development of a service learning writing mentoring program designed to close the achievement gap in writing proficiency for economically disadvantaged seventh grade students. Compared to writing mentoring studies found in the published literature, this program has three distinguishing components. First, it focused on economically disadvantaged middle school students. Second, it provided writing mentoring through a university-school partnership in which college students provided the intervention in collaboration with a seventh-grade teacher. Third, the program used technology to facilitate the mentoring process. Over the course of an academic year, mentors created videos with feedback on 19 writing assignments. The writing mentoring program was associated with a four-fold increase in the percentage of students who were graded as ‘proficient’ on a state standardized writing exam. These results suggest that semi-virtual, intensive writing mentoring and individualized feedback from college students can close the achievement gap and improve the quality of middle level education provided to economically disadvantaged students