Evaluation of Skylab EREP data for land resource management

There are no author-identified significant results in this report

Application of Earth Resources Technology Satellite data to urban development and regional planning: Test site - County of Los Angeles

There are no author-identified significant results in this report

Application of ERTS-1 data to integrated state planning in the state of Maryland

There are no author-identified significant results in this report

The effect of increased channel interaction on speech perception with cochlear implants.

Cochlear implants (CIs) are neuroprostheses that partially restore hearing for people with severe-to-profound hearing loss. While CIs can provide good speech perception in quiet listening situations for many, they fail to do so in environments with interfering sounds for most listeners. Previous research suggests that this is due to detrimental interaction effects between CI electrode channels, limiting their function to convey frequency-specific information, but evidence is still scarce. In this study, an experimental manipulation called spectral blurring was used to increase channel interaction in CI listeners using Advanced Bionics devices with HiFocus 1J and MS electrode arrays to directly investigate its causal effect on speech perception. Instead of using a single electrode per channel as in standard CI processing, spectral blurring used up to 6 electrodes per channel simultaneously to increase the overlap between adjacent frequency channels as would occur in cases with severe channel interaction. Results demonstrated that this manipulation significantly degraded CI speech perception in quiet by 15% and speech reception thresholds in babble noise by 5 dB when all channels were blurred by a factor of 6. Importantly, when channel interaction was increased just on a subset of electrodes, speech scores were mostly unaffected and were only significantly degraded when the 5 most apical channels were blurred. These apical channels convey information up to 1 kHz at the apical end of the electrode array and are typically located at angular insertion depths of about 250 up to 500°. These results confirm and extend earlier findings indicating that CI speech perception may not benefit from deactivating individual channels along the array and that efforts should instead be directed towards reducing channel interaction per se and in particular for the most-apical electrodes. Hereby, causal methods such as spectral blurring could be used in future research to control channel interaction effects within listeners for evaluating compensation strategies

Effect on Antibiotics in High Fiber Diets on Performance of Growing-finishing Pigs

The majority of the pigs in the Upper Midwest are fed a corn-soybean meal base diet. However, alternative feed ingredients are widely used in some regions. The lower performance, daily gain and efficiency of gain that is sometimes observed when other ingredients are used is often associated with higher fiber content of the diet. The pig has little ability to utilize fibrous materials in the stomach and small intestine where most digestion of feed and absorption of nutrients take place. Microorganisms present in the cecum and large intestine do break down fiber to usable products, but it is assumed that relatively small amounts of these products are absorbed. The effect that antibiotics have on fiber utilization and microbial digestion in the lower digestive tract is largely unknown. The experiment reported herein was designed to evaluate pig performance as affected by fiber level, source of fiber and presence of antibiotics

The Effect of Selenium on Pigs of Different Hair Color

It has been suggested that levels of certain trace elements in hair may be associated with the dietary intake of the element. High levels of selenium in the diet have been shown to increase hair selenium in swine and also in cattle. The possibility that the degree of selenium toxicity is related to hair color has been proposed for cattle, horses and swine. This study was conducted to determine if storage of selenium in the hair of pigs varied with their color and also to determine if hair color was related to degree of selenium toxicity

Effect of Sodium Selenite Levels on Tissue and Blood Composition and Performance of Growing-Finishing Swine

A second trial was conducted to further study the problem of selenium toxicity. In this experiment, sodium selenite was utilized as the selenium source. The FDA has approved sodium selenite and sodium selenate supplementation of pig starter diets up to a level of .3 parts per million (ppm) of selenium. The study reported herein was conducted to determine the effect of sodium selenite levels on tissue and blood composition and performance of growing-finishing swine

Effect of Varying Dietary Selenium Levels on Tissue Composition, Blood Composition and Performance of Growing Swine Fed Seleniferous Grains

It is established that selenium is an essential micronutrient as well as a natural toxicant for domestic livestock. However, reports of selenium toxicosis in swine are limited and not well documented. The level at which selenium becomes toxic to swine is thought to be about 8 ppm. This value was derived from the initial selenium research of the 1930\u27s, with considerable extrapolation from other species used in this determination. Since that time, diet composition has become much more complex, nutrient level of diets has increased and feed additives are commonly used. It is not known what effect these factors or other nutritional interrelationships may have on the level at which selenium becomes toxic. Due to the variability of selenium content in feedstuffs and because selenium is now approved as a feed additive, it is important to better define the level at which selenium becomes toxic to swine. This research was conducted to determine the effect of varying dietary selenium levels on tissue and blood composition and performance of growing swine fed seleniferous grains

The effect of increased channel interaction on speech perception with cochlear implants.

Cochlear implants (CIs) are neuroprostheses that partially restore hearing for people with severe-to-profound hearing loss. While CIs can provide good speech perception in quiet listening situations for many, they fail to do so in environments with interfering sounds for most listeners. Previous research suggests that this is due to detrimental interaction effects between CI electrode channels, limiting their function to convey frequency-specific information, but evidence is still scarce. In this study, an experimental manipulation called spectral blurring was used to increase channel interaction in CI listeners using Advanced Bionics devices with HiFocus 1J and MS electrode arrays to directly investigate its causal effect on speech perception. Instead of using a single electrode per channel as in standard CI processing, spectral blurring used up to 6 electrodes per channel simultaneously to increase the overlap between adjacent frequency channels as would occur in cases with severe channel interaction. Results demonstrated that this manipulation significantly degraded CI speech perception in quiet by 15% and speech reception thresholds in babble noise by 5 dB when all channels were blurred by a factor of 6. Importantly, when channel interaction was increased just on a subset of electrodes, speech scores were mostly unaffected and were only significantly degraded when the 5 most apical channels were blurred. These apical channels convey information up to 1 kHz at the apical end of the electrode array and are typically located at angular insertion depths of about 250 up to 500°. These results confirm and extend earlier findings indicating that CI speech perception may not benefit from deactivating individual channels along the array and that efforts should instead be directed towards reducing channel interaction per se and in particular for the most-apical electrodes. Hereby, causal methods such as spectral blurring could be used in future research to control channel interaction effects within listeners for evaluating compensation strategies

Selenium Toxicity in Growing Swine

The Food and Drug Administration has approved sodium selenite and sodium selenate as supplements to pig starter diets up to a level of .3 parts per million (ppm) of selenium. In view of this, the potential exists for selenium poisoning to occur through accidental contamination, incorrect mixing or incorrect formulation of the diet. However, little research has been conducted to determine the maximum level of dietary selenium that could be tolerated without affecting pig performance. The objectives of this study were to establish the level at which selenium becomes toxic to growing swine and to determine which of the parameters evaluated is the best indication of chronic selenium poisoning