Development of techniques for producing static strata maps and development of photointerpretation methods based on multitemporal LANDSAT data

The progress of research conducted in support of the Large Area Crop Inventory Experiment (LACIE) is documented. Specific tasks include (1) evaluation of the static stratification procedure and modification of that procedure if warranted, and (2) the development of alternative photointerpretative techniques to the present LACIE procedures for the identification and selection of training fields (areas)

Application of remote sensing to selected problems within the state of California

There are no author-identified significant results in this report

Application of remote sensing to selected problems within the state of California

There are no author-identified signficant results in this report

Development of techniques for producing static strata maps and development of photointerpretive methods based on multitemporal LANDSAT data

Progress in the evaluation of the static stratification procedure and the development of alternative photointerpretive techniques to the present LACIE procedure for the identification of training fields is reported. Statistically significant signature controlling variables were defined for use in refining the stratification procedure. A subset of the 1973-74 Kansas LACIE segments for wheat was analyzed

Gaussian approximations for stochastic systems with delay: chemical Langevin equation and application to a Brusselator system

We present a heuristic derivation of Gaussian approximations for stochastic chemical reaction systems with distributed delay. In particular we derive the corresponding chemical Langevin equation. Due to the non-Markovian character of the underlying dynamics these equations are integro-differential equations, and the noise in the Gaussian approximation is coloured. Following on from the chemical Langevin equation a further reduction leads to the linear-noise approximation. We apply the formalism to a delay variant of the celebrated Brusselator model, and show how it can be used to characterise noise-driven quasi-cycles, as well as noise-triggered spiking. We find surprisingly intricate dependence of the typical frequency of quasi-cycles on the delay period.Comment: 14 pages, 9 figure

CEO Compensation Structure following Succession: Evidence of Optimal Incentives with Career Concerns

To motivate managers to pursue shareholder interests, boards may design management compensation packages to reward managers for good firm performance. However, note that when CEOs are far from retirement, they have career concerns. In these cases, Gibbons and Murphy argue that it may not be optimal for their current compensation to be too dependent on firm performance. Testing this proposition, we find that abnormal returns are negatively related to the percentage of performance-based pay of newly hired CEOs when companies announce CEO successions. Since these newly hired CEOs are likely some distance from retirement, we interpret these results as being consistent with Gibbons and Murphy; it may be better to allow newly hired CEOs to be paid in human capital increases from the managerial labor market than to have their current pay too closely related to performance

Trace Metals Levels in Inorganic Fertilizers Commercially Available in Nigeria

Aims: To investigate the concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), vanadium (V) and zinc (Zn) in commercially available inorganic fertilizers (calcium superphosphate and urea). Place and Duration of Study: Urea and superphosphate fertilizers were purchased from a local market in Uyo, Southern Nigeria. Methodology: A total of twenty seven fertilizer samples were randomly taken representing triplicate samples from three urea and six superphosphate original fertilizer bags. Each sample were digested and extracted using the ethylenediamine tetraacetic acid (EDTA) extraction technique. The elemental analysis was performed using an inductively coupled plasma atomic emission spectrophotometer (ICP-AES) (Optima 3000 – Perkin Elmer). Results: The analyses indicated the presence of trace metals in commercially available fertilizers sold in Nigeria. Cadmium was found in comparatively high concentrations. Zinc was found present in relatively high concentrations in both urea and phosphate fertilizer samples but As was found in low concentration. By comparison, the superphosphat

Analytical Relevance of Trace Metal Speciation in Environmental and Biophysicochemical Systems

This article presents a review of the analytical relevance of trace metal speciation analysis, which must be considered in environmental and biophysicochemical systems for reliable and efficient assessment and monitoring of trace metals. Examples are given of methodological approaches used for speciation analysis. An overview of speciation analysis in sediments, aquatic ecosystems and agrosystems is also presented

Step Position Distributions and the Pairwise Einstein Model for Steps on Crystal Surfaces

The Pairwise Einstein Model (PEM) of steps not only justifies the use of the Generalized Wigner Distribution (GWD) for Terrace Width Distributions (TWDs), it also predicts a specific form for the Step Position Distribution (SPD), i.e., the probability density function for the fluctuations of a step about its average position. The predicted form of the SPD is well approximated by a Gaussian with a finite variance. However, the variance of the SPD measured from either real surfaces or Monte Carlo simulations depends on $\Delta y$, the length of step over which it is calculated, with the measured variance diverging in the limit $\Delta y \to \infty$. As a result, a length scale $L_{\rm W}$ can be defined as the value of $\Delta y$ at which the measured and theoretical SPDs agree. Monte Carlo simulations of the terrace-step-kink model indicate that $L_{\rm W} \approx 14.2 \xi_Q$, where $\xi_Q$ is the correlation length in the direction parallel to the steps, independent of the strength of the step-step repulsion. $L_{\rm W}$ can also be understood as the length over which a {\em single} terrace must be sampled for the TWD to bear a "reasonable" resemblence to the GWD.Comment: 4 pages, 3 figure