785 research outputs found
A Large Scale Computer-Based Educational System For The Seventies
A computer-based education system in use at the University of Illinois is described. Based on many years of teaching experience with this system and on several technological breakthroughs, a design for a large scale computer-based education system capable of serving up to 4,000 student terminals is presented. Working prototypes of a student console and a data distribution system are described. Finally, a cost estimate of the system is presented
Seeding Cover Crops in Kentucky
The most common reason for seeding a cover crop is to establish cover onto a tilled area following harvest of the previous crop, or onto a disturbed area for a critical seeding , as soon as possible after tillage or disturbance. The reason for establishing the cover crop is to stabilize the exposed surface of bare soil to prevent erosion
SIMSAFADIM-CLASTIC : a new approach to mathematical 3D forward simulation modelling for terrigenous and carbonate marine sedimentation
Most sedimentary modelling programs developed in recent years focus on either terrigenous or carbonate marine sedimentation. Nevertheless, only a few programs have attempted to consider mixed terrigenous-carbonate sedimentation, and most of these are two-dimensional, which is a major restriction since geological processes take place in 3D. This paper presents the basic concepts of a new 3D mathematical forward simulation model for clastic sediments, which was developed from SIMSAFADIM, a previous 3D carbonate sedimentation model. The new extended model, SIMSAFADIM-CLASTIC, simulates processes of autochthonous marine carbonate production and accumulation, together with clastic transport and sedimentation in three dimensions of both carbonate and terrigenous sediments. Other models and modelling strategies may also provide realistic and efficient tools for prediction of stratigraphic architecture and facies distribution of sedimentary deposits. However, SIMSAFADIM-CLASTIC becomes an innovative model that attempts to simulate different sediment types using a process-based approach, therefore being a useful tool for 3D prediction of stratigraphic architecture and facies distribution in sedimentary basins. This model is applied to the neogene Vallès-Penedès half-graben (western Mediterranean, NE Spain) to show the capacity of the program when applied to a realistic geologic situation involving interactions between terrigenous clastics and carbonate sediments
What Happened with No-Till in 1988
No-till (NT) received some bad publicity in 1988 in Kentucky and throughout the Midwest,especially during the early part of last summer\u27s drought. Some farmers found that corn yields were lower with NT than with conventional tillage (CT). However, others observed that the NT corn recovered faster and grew better than CT corn following the rains. Data from Kentucky and Nebraska tend to support this latter observation
Online and Off-Label: Closing the Regulatory Gap in Online Direct-to-Consumer Drug Promotion and Prescribing
The advent of telemedicine led to an evolution in healthcare delivery, making it possible for healthcare professionals to provide remote patient care, thus minimizing or eliminating the need for the patient to visit a physician’s office. Recently, online telemedicine has gained significant popularity, especially in light of the COVID-19 pandemic. This Comment focuses upon online direct-to-consumer telemedicine platforms and their modern usage as one-stop-shops for acquisition of medical advice and medication. Specifically, this Comment explores prescription promotion and prescribing as done through these platforms with a special examination of off-label prescriptions. Several modern online direct-to-consumer telemedicine platforms offer prescription medications directly to the patients who visit their websites. The platforms advertise these prescriptions on both their individual websites as well as through social media. Some of the medications offered and promoted by these platforms are not FDA approved for the conditions that they are advertised to treat. This Comment explores regulations and liability considerations surrounding prescription advertising and prescribing, specifically as they relate to online direct-to-consumer telemedicine platforms. Because these platforms claim to be neither medical providers, pharmaceutical companies, nor online pharmacies, they fall into a regulatory gap. This Comment concludes by suggesting that federal legislation or regulations should be promulgated accordingly to bridge this gap, particularly given increased dependence upon these platforms in light of the COVID-19 pandemic
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Evaluation of the Performance Characteristics of the Lightning Imaging Sensor
The Lightning Imaging Sensor (LIS) that was on board the Tropical Rainfall Measuring Mission (TRMM) satellite captured optical emissions produced by lightning. In this work, we quantify and evaluate the LIS performance characteristics at both the pixel level of LIS events and contiguous clusters of events known as groups during a recent 2-yr period. Differences in the detection threshold among the four quadrants in the LIS pixel array produce small but meaningful differences in their optical characteristics. In particular, one LIS quadrant (Q1, X >= 64; Y >= 64) detects 15%-20% more lightning events than the others because of a lower detection threshold. Sensitivity decreases radially from the center of the LIS array to the edges because of sensor optics. The observed falloff behavior is larger on orbit than was measured during the prelaunch laboratory calibration and is likely linked to changes in cloud scattering pathlength with instrument viewing angle. Also, a two-season comparison with the U.S. National Lightning Detection Network (NLDN) has uncovered a 5-7-km north-south LIS location offset that changes sign because of periodic TRMM yaw maneuvers. LIS groups and flashes that had any temporally and spatially corresponding NLDN reports (i.e., NLDN reported the radio signals from the same group and/or from other groups in the same flash) tended to be spatially larger and last longer (only for flashes) than the overall population of groups/flashes.NASA [80MSFC17M0022]; NASA ROSES-2014 program [NNH14ZDA001N-WEATHER]6 month embargo; published online: 6 June 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Multipattern Consensus Regions in Multiple Aligned Protein Sequences and Their Segmentation
<p/> <p>Decomposing a biological sequence into its functional regions is an important prerequisite to understand the molecule. Using the multiple alignments of the sequences, we evaluate a segmentation based on the type of statistical variation pattern from each of the aligned sites. To describe such a more general pattern, we introduce multipattern consensus regions as segmented regions based on conserved as well as interdependent patterns. Thus the proposed consensus region considers patterns that are statistically significant and extends a local neighborhood. To show its relevance in protein sequence analysis, a cancer suppressor gene called p53 is examined. The results show significant associations between the detected regions and tendency of mutations, location on the 3D structure, and cancer hereditable factors that can be inferred from human twin studies.</p
Analysis of Free Energy Signals Arising from Nucleotide Hybridization Between rRNA and mRNA Sequences during Translation in Eubacteria
A decoding algorithm is tested that mechanistically models the progressive alignments that arise as the mRNA moves past the rRNA tail during translation elongation. Each of these alignments provides an opportunity for hybridization between the single-stranded, 3′-terminal nucleotides of the 16S rRNA and the spatially accessible window of mRNA sequence, from which a free energy value can be calculated. Using this algorithm we show that a periodic, energetic pattern of frequency 1/3 is revealed. This periodic signal exists in the majority of coding regions of eubacterial genes, but not in the non-coding regions encoding the 16S and 23S rRNAs. Signal analysis reveals that the population of coding regions of each bacterial species has a mean phase that is correlated in a statistically significant way with species (G + C) content. These results suggest that the periodic signal could function as a synchronization signal for the maintenance of reading frame and that codon usage provides a mechanism for manipulation of signal phase
Effect of Tillage Tools on Improving Corn Yields from a Compacted Soil
An experiment was conducted on a 2-5% sloping Mercer silt loam soil on a farm in Bourbon/Harrison Counties where very poor corn was grown in 1984 because of soil compaction and drought. Soil test levels of the experimental area were: pH 4.8. and 99, 316, 2070. and 120 lbs/A of P, K, Ca, and Mg, respectively. Examination of the field showed that the compacted zone occurred uniformly in the 0-5 inch surface layer of soil. Cause of this compacted layer was thought to be due to excessive disk tillage in prior years when preparing the field for tobacco production and to winter grazing of a wheat cover crop. The objective of the experiment was to evaluate the influence of fall or spring plowing with a paraplow. chisel plow, or moldboard plow on plowsole bulk density and corn production
Simulating the Water Requirements and Economic Feasibility of Corn in the Midwest
An evaluation of the economics of supplemental irrigation when using a surface water supply must be site specific in order to account for variations in soil moisture holding capacity, watershed area supplying the runoff, climatic conditions, and proposed irrigation management procedures.
With the use of farm specific simulation models to determine grain yields, availability of irrigation water, and economic expenditures involved in irrigation, an economic evaluation of supplemental irrigation can be performed, In the model presented in this report, the Duncan SIMAIZ model is used to predict grain yields using long-term daily weather information. SIMAIZ also determines irrigation water demand for the crop. The Haan Water Yield Model is used to predict flow into a reservoir using the same weather information. By knowing daily water flow into a reservoir and water demand for irrigation, a reservoir size is determined which will supply water at all times for the study period. Simulations are then run by incrementally reducing, by volume, the size of this reservoir, thus limiting the availability of irrigation water, and resulting in reduced irrigated yields.
An economic evaluation is performed for each reservoir size. Costs and benefits included are: initial cost of constructing the reservoir, yearly reservoir maintenance cost, yearly irrigation costs of operation, and additional income resulting from the increase in grain yields. After the project life has been assumed, the model determines the capital available for investing in an irrigation system for a given year and reservoir size. By ranking these values, a probability distribution is obtained indicating the probability of making money in any given year. By using the Central Limit Theorem, these results are converted to the probability of making money over the life of the system.
A sensitivity analysis examines the sensitivity of capital available for investment in an irrigation system to select input variation. The results indicate that great care should be exercised when assigning values to some inputs, while for others, a reasonable estimate is adequate.
This model can be used as a tool for evaluating which irrigation practices, if any, are economically feasible. An example of its use is shown
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