HF coherent scatter radar observations of ionospheric convection during magnetospheric substorms

Observations of ionospheric convection have proven to be extremely valuable in understanding the interaction between the solar wind and the magnetosphere, particularly through the process of magnetic reconnection. In addition, the response of ionospheric convection to substorm activity can provide insight into the mechanisms associated with magnetospheric substorms. In this paper we review observations of ionospheric convection during all phases of the substorm made by HF coherent scatter radars such as those that form the Super Dual Auroral Radar Network (SuperDARN). By concentrating on HF coherent scatter radar observations we stress the importance of ion velocity measurements rather than the conductance controlled ionospheric electrojets. The observations reviewed in this paper demonstrate a number of key results. Following long periods of quiet magnetic activity usually associated with intervals of northward interplanetary magnetic field (IMF), the region of radai backscatter in the dusk local time sector moves equatorward. Based upon this motion of the radar backscatter and a model for the reconnection rate at the dayside magnetopause, it is possible to estimate the length of the reconnection line at the magnetopause, which is found to vary between 12 and 27 R_E. At expansion phase onset, the scatter can often be lost for short periods of time due to absorption of the HF radio wave. There is also evidence that convection vortices in the post noon local time sector relax at the time of expansion phase onset, which hints at a global response to the expansion phase onset. During the latter part of the expansion phase bursts of flow are seen to occur which have repetition rates similar to flux transfer events (FTEs) and current vortices similar to the ionospheric signatures of FTEs. HF coherent scatter radars also play a key role in multi-instrument studies of magnetospheric substorms, for example providing near continuous observations of the convection reversal boundary as a proxy for the polar cap boundary. The recovery phase is the least studied of the various phases but there are key observations of omega bands in the post midnight local time sector, which also hint at the expansion phase being a global phenomenon. The paper concludes with some suggestions of how HF coherent scatter radars will be used in future studies of convection during substorms

Doctor of Philosophy

dissertationIntegration of sensory inputs by the central nervous system (CNS) is necessary for adequate postural stability, but diminishes with age and is further impaired in Parkinson disease (PD). As a result, the CNS cannot appropriately weight sensory stimuli to facilitate postural responses to sudden changes in sensory input. Training the sensorimotor system to ignore or rapidly adapt to aberrant postural cues may improve postural control in PD. We evaluated the influence of acute and repeated exposure to galvanic vestibular stimulation (GVS) on postural responses during static and dynamic tasks to determine whether training improved these responses. We hypothesized that individuals with PD would demonstrate impaired postural recovery responses to acute GVS relative to healthy controls and that individuals with PD and healthy elders would demonstrate diminished adaptive responses to repeated GVS compared to young adults. Twelve individuals with PD (PD group), 15 healthy young adults (HY group), and 11 healthy elders (HE group) participated. Timing of GVS was randomly applied during each task. Fifteen acquisition and nine retention trials with GVS were compared to assess learning. The PD group took longer to stabilize their center of pressure (COP) in quiet stance following GVS acutely compared to controls. The PD and HE groups had lower sample entropy (SaEn) compared to the HY. Neither the PD nor HE groups demonstrated changes in SaEn or meaningful improvements in postural control during acquisition or retention. SaEn in the HY group acutely decreased and then increased at retention which coincided with a meaningful improvement in postural control. The PD group had impaired motor planning, postural preparation, and postural stability during a rise to toes task following acute GVS, but these constructs returned to baseline at later acquisition and retention time points. Controls suppressed GVS acutely Postural coordination decreased acutely in the PD group during tether release. This persisted and an adaptive trend in BOS transition was noted with repeated GVS exposure in this group. No changes were observed in the control groups. Taken together, these results demonstrated that acute GVS differentially affects postural control in individuals with PD. Our results support the hypothesis that reweighting of sensory stimuli is impaired in PD. We also show that individuals with PD are able to suppress attention to a vestibular illusion and demonstrate adaptive responses to a postural threat

Stakeholders’ Awareness and Acceptability of the Leyte Normal University’s Vision, Mission, Goal and Objectives

This study determines the awareness of the stakeholders on the vision, mission, goals, and objectives (VMGO) and how these are disseminated; evaluates the stakeholders’ understanding and acceptance of the VMGO. It uses a descriptive type of research using the survey approach, with a stakeholder survey questionnaire to gather data. Results show that the stakeholders are generally aware, understand and accept the VMGO. The study also reveals that the stakeholders generally perceive that the VMGO are clearly stated, consistent with each other, congruent to educational practices or activities, and attainable. It also shows that the internal stakeholders, especially the administrators and faculty members, are much aware, understand and accept the VMGO than the external stakeholders. The Vision, Mission, Goal and program objectives offered in the College of Arts and Sciences were highly acceptable to the various stakeholders of the University

Three essays on the household: time, money, and future time and money

textHow do time constraints affect household expenditures? How productive are household time expenditures, and how do spouses jointly make decisions over time activities? In this thesis I present three essays on the family, time, and household decision making. In the first essay, I ask: What is the time and goods cost of child? Understanding the substitution between time and market goods is increasingly important as incomes increase and available time does not. In this study, I estimate household demands for time and market goods used in caring for children. To construct a data set with time and market goods, I map information from the American Time Use Survey and the Current Population Survey into the Consumer Expenditure Interview Survey for single women and single women with one or two children. I also construct inter-area price indexes to obtain sufficient price variation for estimation. With these price measures and proxies for the value of single parent's time, I estimate household commodity input demands and the cost of a child, holding utility constant. I also report price, cross-price, and income elasticities for time and goods inputs into child care. In the second essay, I ask: What is the return to volunteering? A household's choice to donate time depends on the productivity of volunteering, yet measuring the productivity of volunteering is elusive because the productivity of volunteers is difficult to quantify. I use differences in student's test scores as a proxy for the productivity of classroom parent volunteers. After correcting for biases due to the endogeneity of volunteers, I found that volunteers increase their child's first grade reading test scores by 12 percent. In addition, teachers assign volunteer parent's children higher grades than non-volunteer parent's children. The final essay attempts to understand how couples make decisions. This is a joint work with my colleague, Jungmin Lee. Using individual bank account data from South Korea, where joint accounts are rare and the legal system emphasizes the individuality of financial transactions, we examine the distribution of financial resources between spouses within households. We find that each member's share of household savings depends on the balance of bargaining power. We also found that an increase in a wife's bargaining power increases total household savings. These findings deviate from the traditional unitary model of the household.Economic

Examining the technology acceptance model and its influence on individuals’ willingness to accept commercial wind farms

This study involved exploration of the acceptance of proposed commercial wind farm construction in rural township areas in the Thumb area of Michigan. The primary objective of the study was to conduct an exploratory analysis to gain an understanding of how residents perceive proposed wind farms in their own communities. This involved examining the influence of perceived usefulness and intent to use on individuals’ acceptance of wind farms in their communities. It also involved exploration of the extent to which personality factors, technophobia, and age moderate these relationships. The study had a cross-sectional research design and relied on a survey to collect data from a convenience sample of 163 individuals. The survey was exposed to people 4,522 times across all methods of promotion. Sampling targeted those who owned or rented property in Tuscola, Huron, and Sanilac Counties, which formed the focus of the study. Pearson’s correlation analysis revealed that independent variables corresponding to perceived usefulness, technophobia, environmental factors, and education were significantly correlated with the dependent variable corresponding to acceptance of wind farms. Independent variables corresponding to property ownership, gender, and age and the Big Five factors of Openness and Conscientiousness were not significantly correlated with the dependent variable. None of Openness, Conscientiousness, technophobia, or age moderated any of the correlations. These results may help guide leaders of municipalities and organizations proposing wind farms to improve communication of wind farm proposals to community member

Evidence for partial quenching of orbital angular momentum upon complex formation in the infrared spectrum of OH-acetylene

The entrance channel leading to the addition reaction between the hydroxyl radical and acetylene has been examined by spectroscopic characterization of the asymmetric CH stretching band of the π-hydrogen bonded OH-acetylene reactant complex. The infrared action spectrum observed at 3278.6 cm−1 (origin) consists of seven peaks of various intensities and widths, and is very different from those previously reported for closed-shell HF/HCl-acetylene complexes. The unusual spectrum arises from a partial quenching of the OH orbital angular momentum in the complex, which in turn is caused by a significant splitting of the OH monomer orbital degeneracy into 2A′ and 2A″ electronic states. The magnitude of the 2A′−2A″ splitting as well as the A rotational constant for the OH-acetylene complex are determined from the analysis of this b-type infrared band. The most populated OH product rotational state, jOH = 9/2, is consistent with intramolecular vibrational energy transfer to the ν2 C≡C stretching mode of the departing acetylene fragment. The lifting of the OH orbital degeneracy and partial quenching of its electronic orbital angular momentum indicate that the electronic changes accompanying the evolution of reactants into products have begun to occur in the reactant complex

Interhemispheric differences in the HF radar signature of the cusp region: A review through the study of a case example

This paper aims to provide a review of our understanding of the HF radar signatures of the cusp and transient magnetopause reconnection phenomena through the study of a case example. Two Super DARN radars observe the conjugate cusp regions during an interval of southward IMF. These observations allow us to determine several parameters relating to the electrodynamics of the magnetopause reconnection process, including the mean reconnection voltage and the reconnection electric fields and X-line lengths in the two hemispheres. In addition, we identify several differences between the radar and flow signatures observed in the two hemispheres, specifically that flux transfer event signatures are observed in the Northern Hemisphere but not the Southern Hemisphere, and that the azimuthal component of the flow excited by reconnection is much greater in the Southern Hemisphere than in the Northern Hemisphere. We finish our discussion by identifying remaining questions regarding the interpretation of HF radar observations of the cusp

Headspace Analysis of the Volatile Oils of Agastache

Equilibrium headspace analysis in combination with gas chromatographylmass spectroscopy was used to identify volatile compounds released by the inflorescences and leaves from individual plants of Agastache foeniculum, Agastache rugosa, and putative hybrids. Methylchavicol was the major constituent in most populations tested. The inflorescences produced from 2 to 6 times more volatiles per gram than did the leaves. A. rugosa produced more volatiles than did A. foeniculum and had less diversity in its volatile composition. The putative hybrid was intermediate between the two proposed parents. The headspace analysis technique gave values comparable to those of traditional volatile oil extraction methods

Inheritance Studies of Aromatic Compounds in Agastache foeniculum (Pursh) Kuntze

Genetic control of volatile oil production in Agastache foeniculum and, more specifically, of the production of myrcene, limonene, and methyl chavicol, three major components of its essential oils, was elucidated. Controlled crosses were made between individuals with different chemotypes, and F2 populations were analyzed for their composition of volatiles by using headspace gas chromatography. Total aromatic volatile emittance was found to be under polygenic control with additive gene effects for four of eight families studied, and each of the three major components was controlled by one to a few genes with recessive to additive effects. Evidence is also presented suggesting that population PI 561057 transmits a genetic factor or factors that suppress the overall production of the major volatile oil components

Identifying Genetic Markers and Their Role in Selecting Chemotypes in Perennial Lamiaceae

This is a report of research progress in this project through early 1995. The results of these initial experiments have led us to propose hypotheses about the patterns of inheritance of aromatic compounds in Agastache foeniculum. We are now testing those hypotheses with larger plant populations. On request, we will be pleased to provide readers with more up-to-date information as we complete the analyses of our ongoing experiments. Until such results are subject to scientific peer review, the data presented in the following report must be considered strictly preliminary