A model for estimating time-variant rainfall infiltration as a function of antecedent surface moisture and hydrologic soil type

Recent research indicates that the use of remote sensing techniques for the measurement of near surface soil moisture could be practical in the not too distant future. Other research shows that infiltration rates, especially for average or frequent rainfall events, are extremely sensitive to the proper definition and consideration of the role of the soil moisture at the beginning of the rainfall. Thus, it is important that an easy to use, but theoretically sound, rainfall infiltration model be available if the anticipated remotely sensed soil moisture data is to be optimally utilized for hydrologic simulation. A series of numerical experiments with the Richards' equation for an array of conditions anticipated in watershed hydrology were used to develop functional relationships that describe temporal infiltration rates as a function of soil type and initial moisture conditions

Definition and testing of the hydrologic component of the pilot land data system

The specific aim was to develop within the Pilot Land Data System (PLDS) software design environment, an easily implementable and user friendly geometric correction procedure to readily enable the georeferencing of imagery data from the Advanced Very High Resolution Radiometer (AVHRR) onboard the NOAA series spacecraft. A software subsystem was developed within the guidelines set by the PLDS development environment utilizing NASA Goddard Space Flight Center (GSFC) Image Analysis Facility's (IAF's) Land Analysis Software (LAS) coding standards. The IAS current program development environment, the Transportable Applications Executive (TAE), operates under a VAX VMS operating system and was used as the user interface. A brief overview of the ICARUS algorithm that was implemented in the set of functions developed, is provided. The functional specifications decription is provided, and a list of the individual programs and directory names containing the source and executables installed in the IAF system are listed. A user guide is provided for the LAS system documentation format for the three functions developed

The ecosystem and evolutionary contexts of allelopathy

Plants can release chemicals into the environment that suppress the growth and establishment of other plants in their vicinity, a process known as ‘allelopathy’. However, chemicals with allelopathic functions have other ecological roles, such as plant defense, nutrient chelation, and regulation of soil biota in ways that affect decomposition and soil fertility. These ecosystem-scale roles of allelopathic chemicals can augment, attenuate or modify their community-scale functions. In this review we explore allelopathy in the context of ecosystem properties, and through its role in exotic invasions consider how evolution might affect the intensity and importance of allelopathic interactions

Merging LANDSAT Derived Land Covers into Quad-referenced Geographic Information Systems

An approach for merging multiscene LANDSAT data bases into existing geographic information systems having 5-second or smaller cells is described. The approach uses the output from the State of Maryland's UNIVAC 1180-based LANDSAT classification program ASTEP (Algorithm Simulation Test and Evaluation) developed by NASA. The structure of the technique was designed to address the problems that emerged as part of the LANDSAT classification of the 64,000 square mile Chesapeake water shed involving twelve scenes. The removal of overlap among adjacent scenes, the crossreferencing of ground control points, and the isolation of the appropriate pixels from the LANDSAT data base for subsequent positioning into a file containing ancillary data referenced to a specific USGS 7 1/2 minute quadrangle sheet are described. Examples illustrate the clustering of classified LANDSAT pixels to define the dominant land use for each of 8,100 cells within a series of quadrangle sheets distributed over the State of Maryland. The approach uses a hard copy terminal tied to an ASTEP algorithm through telephone lines. A coordinate digitizing board for inputing the position of ground control points is also valuable, although manual measurements are possible. The approach is quite efficient and should be especially attractive for use on regional scale studies

An Implementation Strategy For Developing Interdisciplinary Professional Skills Within The Accounting Curriculum

Accounting students are aware of the increasing demand generated from the use of Enterprise Resource Planning (ERP) systems within the world’s major companies. This paper describes the use of this technology within an undergraduate accounting curriculum. The objective is to teach business processes and integration issues. Students simulated a manufacturing ERP implementation by organizing themselves as an implementation team, developing an implementation plan, designing a simple product and product structures, populating the master records, and executing a system walk-through. Students also script core business processes and develop a demonstration of their implementation system for interested parties in the business school. The paper evaluates the implementation project and offers suggestions for enhancing the benefits capable from such pedagogy

Star Enterprises Inc: Getting Control of Your Fixed Assets

Investment in fixed assets constitutes the largest part of the asset side of the balance sheet. This paper looks at the processes to create, purchase, manage, and evaluate the value and effectiveness of fixed assets using an SAP R/3 Resource Planning System. The case can be used to discuss a variety of issues associated with Asset accounting. This case is appropriate for an undergraduate course in accounting informational systems and/or intermediate accounting. The case does require access to an SAP R/3 server, and some knowledge of how to navigate the SAP R/3 system. The scenario uses the current version (ECC6.0) of SAP available to members of the SAP University Alliance

Novel Weapons: Invasive Success and the Evolution of Increased Competitive Ability

When introduced to new habitats by humans, some plant species become much more dominant. This is primarily attributed to escape from specialist consumers. Release from these specialist enemies is also thought by some to lead to the evolution of increased competitive ability, driven by a decrease in the plant\u27s resource allocation to consumer defense and an increase in allocation to size or fecundity. Here, we discuss a new theory for invasive success – the “novel weapons hypothesis”. We propose that some invaders transform because they possess novel biochemical weapons that function as unusually powerful allelopathic agents, or as mediators of new plant–soil microbial interactions. Root exudates that are relatively ineffective against their natural neighbors because of adaptation, may be highly inhibitory to newly encountered plants in invaded communities. In other words, the novel weapons of some plant invaders provide them with an advantage that may arise from differences in the regional coevolutionary trajectories of plant communities. Furthermore, the selective advantage of possessing a novel weapon may result in rapid evolution of that weapon – for example, the production of greater quantities of allelopathic or antimicrobial root exudates. Direct selection of competitive traits provides an alternative to the “grow versus defend” trade-offs that underpin the theory of the evolution of increased competitive ability. Read More: http://www.esajournals.org/doi/abs/10.1890/1540-9295(2004)002%5B0436%3ANWISAT%5D2.0.CO%3B