Feasibility study ASCS remote sensing/compliance determination system

A short-term technical study was performed by the MSC Earth Observations Division to determine the feasibility of the proposed Agricultural Stabilization and Conservation Service Automatic Remote Sensing/Compliance Determination System. For the study, the term automatic was interpreted as applying to an automated remote-sensing system that includes data acquisition, processing, and management

Calcium carbonate, opal, and quartz in Holocene pelagic sediments and the calcite compensation level in the South Atlantic Ocean

Calcium carbonate is the dominant component in the pelagic sediments of the South Atlantic; its distribution pattern can be explained by use of bottom-water circulation. Biogenous opal concentrations occur in two bands, near the Equator and around 50°S; these concentrations are associated with zones of high biological productivity in surface waters...

Nutrient Content of Runoff Water From Rice Fields

Current perception is that nutrient runoff from croplands is a significant contributor to poor water quality in some areas. While extensive research has been conducted to survey and ameliorate this problem for several upland crops, little work has been done to evaluate the problem with flooded rice (Oryza sativa, L.) soils. Since rice production utilizes a major portion of the total irrigation water usage for certain areas, it is important to understand the contribution of rice production to non-point source N and P in surface water. Several production fields were selected to evaluate the concentrations of nutrients in the floodwater at selected distances across the field, including inlet and exit. The fields were evaluated in either 1990, 1991, or 1992 and were managed by the individual rice producer. Water samples were collected from several locations within each field weekly following establishment of the permanent flood and analyzed for inorganic N (NH4-N, No3-N, and NO2-N) and soluble P. The N concentrations in the floodwater normally peaked following N fertilizer application but rapidly declined and remained below 1 mg N L-1. Water management resulted in some variation among locations with respect to the timing and magnitude of these peaks. The P concentrations were usually highest near the well and declined to less than 0.05 mg P L-1 as the water moved across the field. This was attributed to plant uptake, uptake by algae, and sediment deposition. The data indicates that rice fields have the potential to be utilized as a filtration system to reduce the nutrient load of irrigation water similar to constructed wetlands . Use of catfish pondwater, in comparison to well water, resulted in only slightly higher total N and total P levels with higher amounts of the nutrients in the organic form. Although the P levels were high enough to potentially contribute to eutrophication of surface water, the water exiting the field was lower than at the entry point irrespective of the source. Also, the total P (organic + inorganic) concentration was less than 0.05 mg P L- 1

Efficiency and Stability Issues in the Numerical Computation of Fourier Transforms and Convolutions on the 2-Sphere

Earlier work by Driscoll and Healy has produced an efficient algorithm for computing the Fourier transform of band-limited functions on the sphere. In this paper we present a greatly improved inverse transform, and consequent improved convolution algorithm for such functions. We also discuss implementational considerations and give heuristics for allowing reliable floating point implementations of a slightly modified algorithm at little cost in either theoretical or actual performance. This discussion is supplemented with numerical experiments from our implementation in C on a DecStation 5000. These results give strong indications that the algorithm is both reliable and efficient for a large range of useful problem sizes

Methods for comparative evaluation of propulsion system designs for supersonic aircraft

The propulsion system comparative evaluation study was conducted to define a rapid, approximate method for evaluating the effects of propulsion system changes for an advanced supersonic cruise airplane, and to verify the approximate method by comparing its mission performance results with those from a more detailed analysis. A table look up computer program was developed to determine nacelle drag increments for a range of parametric nacelle shapes and sizes. Aircraft sensitivities to propulsion parameters were defined. Nacelle shapes, installed weights, and installed performance was determined for four study engines selected from the NASA supersonic cruise aircraft research (SCAR) engine studies program. Both rapid evaluation method (using sensitivities) and traditional preliminary design methods were then used to assess the four engines. The method was found to compare well with the more detailed analyses

Sediment budget in a deep-sea core from the central equatorial Pacific

Stratigraphic, mineralogic, chemical, and geochronologic measurements on a core from 8°20\u27N, 153°W show that sediment has been accumulating at a rate of 160 g/cm2/106 years. Of this, 125 g is fresh Quaternary sediment while the remainder is lower and middle Tertiary material eroded from nearby outcrops...

Assessment of Keratitis Damage in an Age Dependent Mouse Model Using Analytical Software

Background: Streptococcus pneumoniae (pneumococcus) is a grampositive bacterium that is responsible for diseases such as, otitis media, conjunctivitis, bacterial keratitis, pneumonia, and meningitis. Bacterial keratitis is one of the most common after-effects of trauma to the eye. Some reports have shown the S. pneumoniae spreads through enzymes that are produced to digest the cornea, which in turn can causes blindness. There is a need for more improved measures that can reverse the detrimental effects of the bacteria. The long-term goal of this research is to better understand the complete role of S. pneumoniae and its components in bacterial keratitis to develop next generation therapies to prevent blindness. The purpose of this study is to develop alternative measures to evaluate damage associated with keratitis infection by use of computer applications. Methods: This study analyzed images of the established Keratitis pneumococcal mouse model. The eye images of mice 7-8-week-old and 9-month-old were collected. Additional images were taken on post-infection days one, three, five, and nine, revealing the progression of the infection. Results: The ImageJ Application provided more in depth review to determine the detrimental effects of S. pneumoniae. Through the software, a “Color Threshold” was created on every image to emphasize the area of damage caused by the bacteria. A scatter plot of every image created a map of the particles, and the diameter created a scale demonstrating the impact of keratitis. Data revealed that the most significant increase in infection occurs between Day 1 and 3 post-infection. Conclusions: The study has created a computer model to establish a baseline for the infection process of S. pneumoniae in the traditional mouse model. ImageJ has proven to be a useful tool to analyze the impact of disease on the murine model. Results from this study also provide evidence of the importance of early intervention in ocular disease

Fast Ensemble Smoothing

Smoothing is essential to many oceanographic, meteorological and hydrological applications. The interval smoothing problem updates all desired states within a time interval using all available observations. The fixed-lag smoothing problem updates only a fixed number of states prior to the observation at current time. The fixed-lag smoothing problem is, in general, thought to be computationally faster than a fixed-interval smoother, and can be an appropriate approximation for long interval-smoothing problems. In this paper, we use an ensemble-based approach to fixed-interval and fixed-lag smoothing, and synthesize two algorithms. The first algorithm produces a linear time solution to the interval smoothing problem with a fixed factor, and the second one produces a fixed-lag solution that is independent of the lag length. Identical-twin experiments conducted with the Lorenz-95 model show that for lag lengths approximately equal to the error doubling time, or for long intervals the proposed methods can provide significant computational savings. These results suggest that ensemble methods yield both fixed-interval and fixed-lag smoothing solutions that cost little additional effort over filtering and model propagation, in the sense that in practical ensemble application the additional increment is a small fraction of either filtering or model propagation costs. We also show that fixed-interval smoothing can perform as fast as fixed-lag smoothing and may be advantageous when memory is not an issue