Large space antenna technology applied to radar-imaging, rain-rate measurements, and ocean wind sensing

During the last decade, the utility of spaceborne microwave remote sensing systems for ocean windspeed measurement, ocean wave imaging and sea ice studies was demonstrated. Development of large space antennas offers some interesting possibilities for rain rate measurements, ocean and ice studies, and radar imaging. The joint use of active and passive sensors using the 15 m antenna for ocean, ice, and soil moisture studies; rain rate measurements; and radar imaging is considered. Verification of the frequency agile rain radar concept with Shuttle offers the possibility of much needed rain rate statistics over the ocean

A numerical procedure for recovering true scattering coefficients from measurements with wide-beam antennas

A numerical procedure for estimating the true scattering coefficient, sigma(sup 0), from measurements made using wide-beam antennas. The use of wide-beam antennas results in an inaccurate estimate of sigma(sup 0) if the narrow-beam approximation is used in the retrieval process for sigma(sup 0). To reduce this error, a correction procedure was proposed that estimates the error resulting from the narrow-beam approximation and uses the error to obtain a more accurate estimate of sigma(sup 0). An exponential model was assumed to take into account the variation of sigma(sup 0) with incidence angles, and the model parameters are estimated from measured data. Based on the model and knowledge of the antenna pattern, the procedure calculates the error due to the narrow-beam approximation. The procedure is shown to provide a significant improvement in estimation of sigma(sup 0) obtained with wide-beam antennas. The proposed procedure is also shown insensitive to the assumed sigma(sup 0) model

Phytochemical Investigation of Psychoactive Medicinal Plants for the Treatment of Neurological Disorders

Neurological disorders include disorders such as migraine, tension-type headaches, Parkinson’s disease (PD), epilepsy, dementia, and Alzheimer’s disease (AD). Globally, PD is the second most comneurodegenerative disorder following AD. In developed countries, PD affects 1% of all population over 60 years of age. The prevalence of PD is increasing over the years and is expected to double by 2030. It is proposed that combination of dopaminergic drugs with monoamine oxidase B (MAO-B) inhibitors, anticholinergics, catechol-O-methyl transferase inhibitors, and other non-dopaminergic drugs can better alleviate levodopa-induced motor complications along with better control of motor symptoms. MAO-B inhibitors play a significant role in dopamine (DA) metabolism and can be used as monotherapy in the early stages of PD, or in combination with levodopa. Currently, there are only three MAO-B inhibitors that are approved by Food and Drug Administration (FDA): selegiline, rasagiline, and safinamide. Hence, there is the need to discover potent and selective MAO-B inhibitors for effective treatment of PD. About 60% of the marketed drugs today are either natural products or derivatives that are inspired from natural products. We studied plants with extensive traditional use in CNS-related disorders, in which the chloroform extract of C. urticifolia exhibited potent inhibition of MAO-A and -B. Calea urticifolia (Asteraceae) commonly known as “Juanislama” is native to the Central America. Bioassay-guided fractionation has been implemented for the isolation of the secondary metabolites from C. urticifolia. From the bioactive fraction, acacetin and a series of sesquiterpenes were isolated; acacetin was found to be the bioactive compound. A series of acacetin analogs were designed with the aid of computational docking studies, to improve their selectivity towards MAO-B. The structures of the isolated compounds were determined on the basis of HR-MS and 1D- and 2D-NMR studies; configurations were partly established by ECD calculations. Monoamine oxidase assays were performed on the extracts, fractions, and purified compounds. Molecular modeling and molecular dynamic studies were used to predict the binding modes on the active sites of the MAO isoenzymes

Evaluating a Personal Stress Monitoring System

Now-a-days, Life is generally much more stressful than in the past. Stress is the word that we use when we feel that we are overloaded mentally in our thoughts and wonder whether we can really cope with those placed upon us. Sometimes, stress gets us going and they are good for us but at other times, it could be the cause to undermine both our mental and physical health. The way we respond to a challenge can be considered as a kind of stress. Part of our response to a challenge is physiological and affects our own physical state. When we are faced with a challenge or a threat, our body releases some resources to protect us against them - either to get away as fast as we can, or to fight against them. This fight-or-flight response is our body\u27s sympathetic nervous system reacting to a stressful event. During this response, our body produces larger quantities of the chemicals such as cortisol, adrenaline and noradrenaline, which triggers a higher heart rate, heightened muscle preparedness, sweating, and alertness. All these factors help us to protect ourselves in a dangerous or challenging situation. But based on the frequency of stress facing by a person, these changes may affect his or her health negatively. In order to evaluate an individual\u27s stress, I worked on this thesis in developing a personal stress monitoring system to capture the stress undergoing by an individual in his or her daily life

The Design and Implementation of a Yield Monitor for Sweetpotatoes

A study of the soil characteristics, weather conditions, and effect of management skills on the yield of the agricultural crop requires site-specific details, which involves large amount of labor and resources, compared to the traditional whole field based analysis. This thesis discusses the design and implemention of yield monitor for sweetpotatoes grown in heavy clay soil. A data acquisition system is built and image segmentation algorithms are implemented. The system performed with an R-Square value of 0.80 in estimating the yield. The other main contribution of this thesis is to investigate the effectiveness of statistical methods and neural networks to correlate image-based size and shape to the grade and weight of the sweetpotatoes. An R-Square value of 0.88 and 0.63 are obtained for weight and grade estimations respectively using neural networks. This performance is better compared to statistical methods with an R-Square value of 0.84 weight analysis and 0.61 in grade estimation

Harm Perceptions of Secondhand Aerosol Exposure and Opinions About Acceptability and ECIG Use Inside of Vehicles Among ECIG Users

Significance: Limited research has examined electronic cigarette (ECIG) secondhand aerosol (SHA) exposure. Initial research shows ECIG SHA exposure may be associated with negative health effects, but many ECIG users associate little harm with SHA exposure and may be more likely to engage in ECIG use in indoor settings, such as inside of vehicles. This study’s purpose was to examine the association between harm perceptions of ECIG SHA and ECIG use inside of vehicles behaviors and perceptions. Methods: Current (past 30-day) adult ECIG users in the US (n=1002; mean age=32.8; 50.4% women) completed an online survey examining harm perceptions of ECIG SHA (“no harm�, “little harm�, “some harm�, “a lot of harm�), opinions about acceptability of ECIG use inside of vehicles in the presence of others(“always allowed� or “be allowed under some conditions�, “never be allowed�), and ECIG use behaviors inside of vehicles (“always�, “sometimes�, “rarely�, “never�). Descriptive statistics and chi-square tests were conducted to examine associations between variables. Results: Most participants (78.3%) who owned a vehicle reported ECIG use inside their vehicle “almost always� or “sometimes.� Participants perceived ECIG SHA exposure was associated with “little harm� (34.6%) or “some harm� (36.5%), and few (8.6%) associated “a lot of harm.� Over three-quarters (79.2%) reported ECIG use inside vehicles when adults were present and 36.6% reported ECIG use when children were present. Most (89.5%) stated that ECIG use should be allowed in the presence of other adults and 39.9% reported ECIG use should be allowed with children present. ECIG users who associated no or little harm with ECIG SHA exposure were more likely to report ECIG use inside of vehicles, ECIG use inside of vehicles when adults or children were present, and to perceive ECIG use inside of vehicles when adults or children were present was acceptable (ps<0.05). Conclusion: In this study, lower harm perception of ECIG SHA exposure was associated with increased ECIG use inside of vehicles. Future research should assess the impact of increasing harm perceptions of SHA on indoor ECIG use behaviors