TECHNOLOGICAL ADVANCES IN AGRICULTURAL ECONOMICS CURRICULA

The potential use of computers and electronic technology have created considerable interest among educators in agricultural economics. This paper provides an overview of the use of electronic technology within agricultural economics curricula; examines areas in which technological development offers promise and examines issues associated with adoption of the technology.Agricultural economics curricula, Computers, Multimedia, Technological adoption, Teaching/Communication/Extension/Profession,

RAM-Efficient External Memory Sorting

In recent years a large number of problems have been considered in external memory models of computation, where the complexity measure is the number of blocks of data that are moved between slow external memory and fast internal memory (also called I/Os). In practice, however, internal memory time often dominates the total running time once I/O-efficiency has been obtained. In this paper we study algorithms for fundamental problems that are simultaneously I/O-efficient and internal memory efficient in the RAM model of computation.Comment: To appear in Proceedings of ISAAC 2013, getting the Best Paper Awar

3+1 Approach to the Long Wavelength Iteration Scheme

Large-scale inhomogeneities and anisotropies are modeled using the Long Wavelength Iteration Scheme. In this scheme solutions are obtained as expansions in spatial gradients, which are taken to be small. It is shown that the choice of foliation for spacetime can make the iteration scheme more effective in two respects: (i) the shift vector can be chosen so as to dilute the effect of anisotropy on the late-time value of the extrinsic curvature of the spacelike hypersurfaces of the foliation; and (ii) pure gauge solutions present in a similar calculation using the synchronous gauge vanish when the spacelike hypersurfaces have extrinsic curvature with constant trace. We furthermore verify the main conclusion of the synchronous gauge calculation which is large-scale inhomogeneity decays if the matter--considered to be that of a perfect-fluid with a barotropic equation of state--violates the strong-energy condition. Finally, we obtain the solution for the lapse function and discuss its late-time behaviour. It is found that the lapse function is well-behaved when the matter violates the strong energy condition.Comment: 21 pages, TeX file, already publishe

pH electrode performance under automated management conditions

pH is frequently measured in laboratories, but to have confidence in the results it is necessary to know that it was measured properly. For an electrode to give accurate results it must be treated well and calibrated correctly. In this paper, an automated system for pH measurement is described; the system uses the operational pH scale and calibrates using two or three buffer solutions, taking proper account of the effects of temperature on the system. The system can be programmed with standard methods and procedures to ensure that the electrode gives the best possible performance. Calibrations and measurements within the system are reproducible, and the automated system is more robust than the manual pH meter, and requires less operator time

Semantic effects in sentence recall: The contribution of immediate vs delayed recall in language assessment

Sentence recall is increasingly used to assess language. It is widely debated what the task is actually testing, but one rarely explored aspect is the contribution of semantics to sentence recall. The few studies that have examined the role of semantics in sentence recall have employed an 'intrusion paradigm', following Potter and Lombardi (1990), and their paradigm relies on interference errors with conclusions based on an analysis of error patterns. We have instead manipulated the semantic plausibility of whole sentences to investigate the effects of semantics on immediate and delayed sentence recall. In Study 1, adults recalled semantically plausible and implausible sentences either immediately or after distracter tasks varying in lexical retrieval demands (backward counting and picture naming). Results revealed significant effects of plausibility, delay, and a significant interaction indicating increasing reliance on semantics as the demands of the distracter tasks increased. Study 2, conducted with 6-year-old children, employed delay conditions that were modified to avoid floor effects (delay with silence and forward counting) and a similar pattern of results emerged. This novel methodology provided robust evidence showing the effectiveness of delayed recall in the assessment of semantics and the effectiveness of immediate recall in the assessment of morphosyntax. The findings from our study clarify the linguistic mechanisms involved in immediate and delayed sentence recall, with implications for the use of recall tasks in language assessment. Learning outcomes: The reader will be able to: (i) understand the difference between immediate and delayed sentence recall and different types of distractors, (ii) understand the utility of immediate and delayed recall sentence recall in language assessment, (iii) discuss suitability of delayed recall for the assessment of semantics

Collapse of a Circular Loop of Cosmic String

We study the collapse of a circular loop of cosmic string. The gravitational field of the string is treated using the weak field approximation. The gravitational radiation from the loop is evaluated numerically. The memtric of the loop near the point of collapse is found analytically.Comment: 15 page