Low-mass star-forming regions have a lifetime which is greater than their dynamical time and must therefore be, in an average sense, in mechanical equilibrium. The work presented here proposes that an equilibrium exists between the self-gravity, gas pressure, and the magnetic field and the waves it supports. Specifically the equilibrium in the direction perpendicular to the ordered magnetic field is given by the Lorentz force, while that parallel to the field is given by an Alfvén wave pressure force. The work detailed in this thesis models a low-mass star-forming region as a one-dimensional gas slab with a magnetic field lying perpendicular to the layer. Analytical, self-consistent models are formulated to study the equilibrium parallel to the background magnetic field. It is found that both short-wavelength (modelled using the WKB approximation) and large-amplitude, long-wavelength Alfvén waves can provide the necessary support parallel to the magnetic field, generating model cloud thicknesses that are consistent with the observations. The effect of damping by the linear process of ion-neutral friction is considered. It is found that the damping of the waves is not a necessary condition for the support of the cloud although it is an advantage. The possible sources of these waves are discussed. The Alfvén waves are also found to make an important contribution to the heating of a low-mass star-forming region. By modelling the dominant heating and cooling mechanisms in a molecular cloud, it is discovered that a cloud supported against its self-gravity by short-wavelength Alfvén waves will be hotter at its outer edge than in the central regions. These models successfully describe a low-mass star-forming region in equilibrium between its self-gravity, the gas pressure and an Alfvén wave pressure force. The question of the stability of such an equilibrium is considered, specifically that of an isothermal gas slab supported by short-wavelength Alfvén waves. The initial results suggest that the presence of a magnetic field and its associated Alfvén waves have a stabilising effect on the layer, and encourage further consideration of the role of Alfvén waves in low-mass star-forming regions.

The central problem of this study was to identify and compare the basic sex bias beliefs of (1) male and female postsecondary occupational educators; (2) post-secondary occupational educators teaching in male-oriented, nonsex-oriented, and female-oriented programs; and (3) postsecondary occupational educators teaching in small, medium, and large campuses. A secondary problem was to determine (1) if there was a relationship between the biographical variables (sex, age, educational level [highest degree earned], years of teaching experience, and years of occupational experience) and the identified basic sex bias beliefs of post-secondary occupational educators; and (2) if there were differences in the identified basic sex bias beliefs of postsecondary occupational educators who teach in programs of varying sex orientation (male-oriented, nonsex-oriented, and female-oriented) and who teach in campuses of varying sizes (small, medium, and large). The research procedures used in this study consisted of five steps. These steps were: (1) reviewing the literature for basic sex bias beliefs; (2) developing, validating, and pilot testing the instrument; (3) collecting data; (4) analyzing the data; and (5) interpreting and reporting the data. The instrument used to collect data was developed in a scale format by the researcher, and contains a total of 30 items. Eleven of these items measure general sex bias and 19 measure same sex bias/opposite sex bias. A random sample of postsecondary occupational educators (417) from USOE Region Three (Delaware, Maryland, Pennsylvania, Virginia, West Virginia, and the District of Columbia) were potential respondents in this study. The analysis of data consisted of (1) descriptive statistics to provide a respondent profile; (2) descriptive statistics to identify and compare the basic beliefs; and (3) statistical tests of the research questions (Multivariate Analysis of Variance and Pearson correlations). / Ed. D.

The problem of this study was twofold. The first problem was to determine whether differences existed between elementary teachers, elementary principals, secondary teachers, secondary principals, and central office administrators in tenns of their perceptions as to the effectiveness of selected personnel services in the Kanawha County School System. The second problem was to determine the relationship between selected personal characteristics of elementary teachers, elementary principals, secondary teachers, secondary principals, and central office administrators in the Kanawha County School System and their perceptions of the effectiveness of selected personnel services. A questionnaire on selected personnel services was developed from the relevant literature and national standards adopted by the American Association ot School Personnel Administration. The statistical procedures used on the responses to the questions were frequency, distribution, percentage, chi square, mean, and the Pearson Product Moment Correlation Coefficient. A series of tables was developed to present the data collected from the responses. The results of the first part of the study indicated that differences existed in the perceptions of the effectiveness of selected personnel services by the five groups surveyed. The differences were particularly noted between teachers and administrators in the area of personnel administration entitled conditions of service. The second part of the study revealed that no significant relationship existed between selected personal characteristics of the five groups surveyed and their perceptions of the effectiveness of selected personnel services. / Doctor of Education

In this study a linear spent fuel storage model is developed to identify cost-effective spent nuclear fuel storage strategies. The purpose of this model is to provide guidelines for the implementation of the optimal time-dependent spent fuel storage capacity expansion in view of the current economic and regulatory environment which has resulted in phase-out of the closed nuclear fuel cycle. Management alternatives of the spent fuel storage backlog, which is created by mismatch between spent fuel generation rate and spent fuel disposition capability, are represented by aggregate decision variables which describe the time dependent on-reactor-site and off-site spent fuel storage capacity additions, and the amount of spent fuel transferred to off-site storage facilities. Principal constraints of the model assure determination of cost optimal spent fuel storage expansion strategies, while spent fuel storage requirements are met at all times. A detailed physical and economic analysis of the essential components of the spent fuel storage problem, which precedes the model development, assures its realism. The effects of technological limitations on the on-site spent fuel storage expansion and timing of reinitiation of the spent fuel reprocessing on optimal spent fuel storage capacity expansion are investigated. The principal results of this study indicate that a) expansion of storage capacity beyond that of currently planned facilities is necessary, and b) economics of the post-reactor fuel cycle is extremely sensitive to the timing of reinitiation of spent fuel reprocessing. Postponement of reprocessing beyond mid-1982 may result in net negative economic liability of the back end of the nuclear fuel cycle. / Ph. D.

The purpose of this study was to investigate the usefulness and practicality of the hybrid load flow program. After the load flow program was defined, the desirability for rapid solution times in certain applications was explained. An analog model of an electric power system was developed. This model included representations of transmission lines, buses, loads and generations. When the hybrid load flow was implemented, the results indicated that the algorithm was very useful in terms of speed and accuracy. An algorithm for determining the impedance matrix of the power system network was developed using the hybrid computer. When implemented, it proved helpful in improving the accuracy of the hybrid load flow. Application of the hybrid computer for use in an optimal load flow problem was also investigated. An algorithm for the economic dispatch problem was developed. Finally, conclusions were made about the applicability of the hybrid load flow to the electric power industry and recommendations were presented for further research. / Master of Science

Research was conducted to determine relationships among nutrients in corn plants on soils with high yield potentials, to study the suitability of soil tests for estimation of micronutrient concentrations in plants, and to determine if B fertilization affects corn grain yields on selected Virginia soils. Fifty-three field sites were selected in 15 counties throughout Virginia for evaluation of nutrient interactions in plant tissue and micronutrient soil tests. The majority of the soils under study had high yield potentials as attested by the average corn grain yield of 8743 kg/ha. Boron application did not increase corn grain yield in field experiments on five soils. Concentrations of B, Ca, Cu, Fe, K, Mg, Mn, N, P, S, and Zn in the earleaf at the early silk growth stage were determined to assess the nutrient status of corn plants. The experimental data indicated that nutrient concentrations were too low to provide adequate amounts to corn plants on many sites. Corn plants on all of the sites were below the reported critical level of 0.26% S in the earleaf at the early silk growth stage. It was concluded that this critical level may be too high for S deficiency symptoms of corn plants. The negative relationship between concentrations of Ca and K in whole corn plants was attributed to high plant available K in soil which decreases Ca uptake by corn plants. A positive correlation between N and Zn in the sixth leaf tissue was attributed to higher Zn availability as N fertilization decreased soil pH levels. High amounts of soil P which had low soil Zn levels probably caused the inverse relationship between P and Zn in the sixth leaf tissue. Increases in availability of both Cu and Fe at lower pH levels may be responsible for the positive correlation between these micronutrients in the earleaf tissue. Multiple correlation analyses completed between ppm Mn in tissue and dilute HCl-H₂SO₄ extractable soil Mn, pH and organic matter content indicated coefficients of determinations of 0.993 and 0.990 for the 0-20.3- and 0-40.6-cm soil depths, respectively. These data suggest that the Mn test may be a good indicator of available soil Mn to corn plants. Hot water soluble B, soil pH and organic matter content did not give a good indication of B concentrations in corn plants. Extractable Zn by the EDTA-(NH₄)₂CO₃ procedure, soil pH and organic matter content accounted for 84.1% of the variation in Zn concentration in the earleaf of plants at the early silking stage. / Master of Science

M.S.

Biological activity of IL-2 and IL-7 in vivo is significantly increased when complexed with some of the respective anti-cytokine mAb. Different immune cell subsets can be preferentially stimulated depending on the anti-IL-2 mAb used to complex IL-2. IL-2/anti-IL-2 mAb S4B6 immunocomplexes (IL-2/S4B6) induce preferential expansion of CD122high cells whereas IL-2/anti-IL-2 mAb JES6-1 immunocomplexes (IL-2/JES6-1) highly selectively stimulate CD25high cells in mice. Similarly, IL-7/anti-IL-7 mAb M25 immunocomplexes (IL-7/M25) possess higher stimulatory activity for both naïve and memory CD8+ T cells in vivo in comparison to free IL-7. CTLA-4 and PD-1 molecules are inhibitory receptors which negatively regulate proliferation, survival and effector functions of T cells. Blocking antibodies against these molecules represent promising immunotherapeutic tool for treatment of malignant diseases. We examined possible synergism of IL-2/S4B6 and αCTLA-4 plus αPD-1 mAbs in tumor-bearing mice. We found that the expansion of recently activated CD8+ T cells driven by IL-2/S4B6 was further augmented by αCTLA-4 plus αPD-1 mAbs. However, these two immunotherapeutic approaches did not show synergistic antitumor activity in any mouse tumor model tested. Next, we showed that IL-7/M25 possessed higher biological activity...

Both traffic congestion and road accidents impose a burden on society, and it is therefore important for transport policy makers to reduce their impact. An ideal scenario would be that traffic congestion and accidents are reduced simultaneously, however, this may not be possible since it has been speculated that increased traffic congestion may be beneficial in terms of road safety. This is based on the premise that there would be fewer fatal accidents and the accidents that occurred would tend to be less severe due to the low average speed when congestion is present. If this is confirmed then it poses a potential dilemma for transport policy makers: the benefit of reducing congestion might be off-set by more severe accidents. It is therefore important to fully understand the relationship between traffic congestion and road accidents while controlling for other factors affecting road traffic accidents. The relationship between traffic congestion and road accidents appears to be an under researched area. Previous studies often lack a suitable congestion measurement and an appropriate econometric model using real-world data. This thesis aims to explore the relationship between traffic congestion and road accidents by using an econometric and GIS approach. The analysis is based on the data from the M25 motorway and its surrounding major roads for the period 2003-2007. A series of econometric models have been employed to investigate the effect of traffic congestion on both accident frequency (such as classical Negative Binomial and Bayesian spatial models) and accident severity (such as ordered logit and mixed logit models). The Bayesian spatial model and the mixed logit model are the best models estimated for accident frequency and accident severity analyses respectively. The model estimation results suggest that traffic congestion is positively associated with the frequency of fatal and serious injury accidents and negatively (i.e. inversely) associated with the severity of accidents that have occurred. Traffic congestion is found to have little impact on the frequency of slight injury accidents. Other contributing factors have also been controlled for and produced results consistent with previous studies. It is concluded that traffic congestion overall has a negative impact on road safety. This may be partially due to higher speed variance among vehicles within and between lanes and erratic driving behaviour in the presence of congestion. The results indicate that mobility and safety can be improved simultaneously, and therefore there is significant additional benefit of reducing traffic congestion in terms of road safety. Several policy implications have been identified in order to optimise the traffic flow and improve driving behaviour, which would be beneficial to both congestion and accident reduction. This includes: reinforcing electronic warning signs and the Active Traffic Management, enforcing average speed on a stretch of a roadway and introducing minimum speed limits in the UK. This thesis contributes to knowledge in terms of the relationship between traffic congestion and road accidents, showing that mobility and safety can be improved simultaneously. A new hypothesis is proposed that traffic congestion on major roads may increase the occurrence of serious injury accidents. This thesis also proposes a new map-matching technique so as to assign accidents to the correct road segments, and shows how a two-stage modelling process which combines both accident frequency and severity models can be used in site ranking with the objective of identifying hazardous accident hotspots for further safety examination and treatment.

In this thesis, I examine the nature and role of persuasion in Roman politics in the period immediately following the assassination of Caesar on the Ides of March 44 B.C. until the capture of the city of Rome by his heir Octavianus in August 43 B.C. The purpose of my thesis is to assess the extent to which persuasion played a critical role in political interactions and in the decision-making processes of those involved during this crucial period in Roman history. I do this by means of a careful discussion and analysis of a variety of different types of political interactions, both public and private. As regards the means of persuasion, I concentrate on the role and use of oratory in these political interactions. Consequently, my thesis owes much in terms of approach to the work of Millar (1998) and, more recently, Morstein-Marx (2004) on placing oratory at the centre of our understanding of how politics functioned in practice in the late Roman republic. Their studies, however, focus on the potential extent and significance of mass participation in the late Roman republican political system, and on the contio as the key locus of political interaction. In my thesis, I contribute to improving our new way of understanding late Roman republican politics by taking a broader approach that incorporates other types of political interactions in which oratory played a significant role. I also examine oratory as but one of a variety of means of persuasion in Roman political interactions. Finally, in analyzing politics and persuasion in the period immediately after Caesar’s assassination, I am examining not only a crucial period in Roman history, but one which is perhaps the best documented from the ancient world. The relative richness of contemporary evidence for this period calls out for the sort of close reading of sources and detailed analysis that I provide in my thesis that enables a better understanding of how politics actually played out in the late Roman republic.