Two Lithotectonic Boundaries In Western North Carolina: Geologic Interpretation of A Region Surrounding Sylva, Jackson County

Understanding the geology of any region begins with the construction of high-quality geologic maps. As maps for a specific region are revised in greater detail, geologic understanding is improved. This study involved detailed geologic mapping (at the scale of 1 : 24,000) of a portion of the southern Appalachian Blue Ridge that was previously only mapped by reconnaissance. It is hoped that the research herein will add to the present understanding of the Blue Ridge province and of the entire Appalachian orogenic belt. During the course of field mapping, three lithotectonic units were divided, each separated from the others by a major fault. Unit 1, located in the northwesternmost portion of the study area, is part of the Great Smoky Group and is comprised of feldspathic metaquartzite and metagraywacke interlayered with subordinate aluminous schist. Unit 1 is bounded on the south by the Hayesville fault. Unit 2 occurs immediately south of the Hayesville fault and is composed of feldspathic metagraywacke, biotite gneiss, and interlayered amphibolite. This sequence is correlated with the Tallulah Falls Formation. In addition, Unit 2 contains large masses of amphibolite and ultramafic rock that are not considered part of the Tallulah Falls stratigraphic sequence. Unit 3 is the southeastemmost unit and consists of an assemblage of aluminous metagraywacke, feldspathic metaquartzite, aluminous schist, and interlayered amphibolite. These rocks are correlated with the Otto Formation which has been mapped directly along strike to the southwest. A small ultramafic body is also present in Unit 3. Unit 3 is separated from Unit 2 by the Soque River fault. Unit 2 is the hanging wall for both the Hayesville and Soque River faults. The study area is structurally complex. Structural and metamorphic evidence indicates that all lithotectonic units were juxtaposed prior to the onset of metamorphism and early-stage deformation. Six separate fold generations have been recognized. Early-stage folding (F1 and F2) are isoclinal flowage folds, each of which involved transposition of a preexisting layering and development of a regionally penetrative foliation. The dominant foliation now present in the study area was designated S2 because F2 folds fold a preexisting foliation. Intermediate-stage folds are tight, passive flow to flexural flow folds. Intermediate-stage fold geometries indicate that rheologic contrasts developed and affected fold mechanics as the rocks cooled. Late-stage folds are open flexural flow and flesural slip buckle folds indicating that the rocks behave more rigidly and had cooled still further. Late stage deformation is responsible for the development of the Webster-Addie dome , a prominent doubly-plunging antiform in the study area. A window through Unit 2, exposing the underlying rocks of Unit 3, has developed in the core of the Webster-Addie dome. One major regional metamorphism affected the rocks in the study area is associated with the Taconic orogeny. Rocks in this study area underwent medium-pressure facies series metamorphism, ultimately attaining kyanite-sillimanite grade in the amphibolite facies. The sillimanite isograd has been domed in the study area exposing higher pressure (kyanite grade) rocks in the center. Textural relationships indicate that garnet growth continued well after the regional metamorphic peak. Thermobarometric calculations based on mineral equilibria indicate that perhaps closure temperatures varied between pelites, gneisses, and amphibolites. Maximum conditions for metamorphism (recorded by rocks with the highest closure temperature) were approximately 725°C and 9 kb. Metamorphic conditions recorded by rocks with the lowest closure temperature were 550°C and 5.5 kb. Retrograde metamorphism (chlorite-biotite zone) is evident in some samples and may be associated with Acadian regional metamorphism. The geochemistry of amphibolites occurring in Units 2 and 3 indicates that they were mafic igneous rocks prior to metamorphic recrystallization. Trace element abundances indicate that amphibolites originated as ocean floor basalts. This suggests that Units 2 and 3 were deposited in a tectonic regime in which lavas from a depleted mantle source could be tapped and emplaced without significant crustal contamination

Irish-Soviet diplomatic and friendship relations, 1919-80

This thesis offers a contribution to Irish historiography with a study of Ireland’s diplomatic and friendship relations with the Soviet Union in the ‘short Soviet twentiethcentury’. To date no such study has been produced. The study has as its central focus developments surrounding the establishment of formal diplomatic relations between the two states in 1973, and considers aspects of how those relations evolved down to 1980. To provide an understanding of the legacy of relations prior to formalisation of relations, the study commences with a survey of the principal diplomatic contacts from 1919 to 1972, including those that took place in America between representatives of the nascent Irish republic and Soviet Russia during the revolutionary period of 1919-21, contacts between the Irish Free State and the Soviet Union at the League of Nations in the mid- 1930s, and between the Republic of Ireland and the Soviet Union at the United Nations from 1955 to 1972. It proceeds to examine in more detail events surrounding the establishment of formal diplomatic relations in 1973, and experiences during the first six years at the Irish embassy to Moscow, and at the Soviet embassy to Dublin. To gain insights from a wider societal perspective with oral and private archival evidence, an account of the Ireland-U.S.S.R. Society – a unique friendship organisation located at a conjunction of informational, cultural, academic, trade union and tourist affairs in Irish- Soviet relations – is next presented. The final two areas of study draw upon archival records of the Irish Department of Foreign Affairs for the years 1974-80, which have only recently been made available at the National Archives of Ireland. Drawing in the main on the central registry series of files containing political reports sent to Dublin by Ireland’s first ambassador to Moscow, Dr Edward Brennan, the penultimate focus is upon the ‘island of Ireland’ elements of those reports. Lastly, the thesis discusses Ireland’s second relationship with the Soviet Union, as mediated through European Political Cooperation (E.P.C.), a parallel framework of the European Economic Community. This discussion is principally facilitated by the records of Ireland’s involvement in a confidential subgroup of E.P.C. – the Eastern Europe Working Group – which was dedicated to an ongoing compilation of studies of the Soviet Union and its fellow member states of COMECON

A Micro-level Analysis of Recent Increases in Labor Force Participation among Older Workers

Aggregate data reveal a sizable increase in labor force participation rates since 2000 among workers on the cusp of retirement, reverting back to levels for older men not seen since the 1970s. These aggregate numbers are useful in that they document overall trends, but they lack the ability to identify the reasons behind workers’ decisions. The Health and Retirement Study (HRS) spans the last dozen years from 1992 to 2004, includes two cohorts of retirees, and provides micro-level data regarding these recent trends. Moreover, the HRS contains information on older Americans and the types of jobs they are taking (full-time versus part-time, self-employed versus wage-and-salary, low-paying versus high-paying, blue collar versus white collar, etc.). This study capitalizes on the richness of the HRS data and explores labor force determinants and outcomes of older Americans, with an emphasis on retirees' choices in recent years. We present a cross-sectional and longitudinal description of the financial, health, and employment situation of older Americans. We then explore retirement determinants using a multinomial approach to model gradual retirement and a two-step approach to model the work-leisure and hours intensity decisions of older workers. Evidence suggests that the majority of older Americans retire gradually, in stages, and that younger retirees continue to respond to financial incentives just as their predecessors did. In addition, recent macro-level changes appear to have blurred the distinction between younger and middle-aged retirees.Economics of Aging, Partial Retirement, Gradual Retirement

An Update on Bridge Jobs: The HRS War Babies

Are today’s youngest retirees following in the footsteps of their older peers with respect to gradual retirement? Recent evidence from the Health and Retirement Study (HRS) suggests that most older Americans with full-time career jobs later in life transitioned to another job prior to complete labor force withdrawal. This paper explores the retirement patterns of a younger cohort of individuals from the HRS known as the “War Babies.” These survey respondents were born between 1942 and 1947 and were 57 to 62 years of age at the time of their fourth bi-annual HRS interview in 2004. We compare the War Babies to an older cohort of HRS respondents and find that, for the most part, the War Babies have followed the gradual-retirement trends of their slightly older predecessors. Traditional one-time, permanent retirements appear to be fading, a sign that the impact of changes in the retirement income landscape since the 1980s continues to unfold.Economics of Aging, Partial Retirement, Gradual Retirement

The Role of Re-entry in the Retirement Process

To what extent do older Americans re-enter the labor force after an initial exit and what drives these “unretirement” decisions? Retirement for most older Americans with full-time career jobs is not a one-time, permanent event. Labor force exit is more likely to be a process. Prior studies have found that between one half and two thirds of career workers take at least one other job before exiting from the labor force completely. The transitional nature of retirement may be even more pronounced when considering the impact of re-entry. This paper examines the extent to which older Americans with career jobs re-entered the labor force. The analysis is based on data from the Health and Retirement Study (HRS), an ongoing, longitudinal survey of older Americans that began in 1992. We examined the retirement patterns of a subset of 5,617 HRS respondents who were on a full-time career job at the time of the first interview. Logistic regression was used to explore determinants of re-entry among those who initially exited the labor force. We found that approximately 15 percent of older Americans with career jobs returned to the labor force after initially exiting. Respondents were more likely to re-enter if they were younger, were in better health, or had a defined-contribution pension plan. This research provides empirical evidence of how older Americans are utilizing bridge jobs as they transition from career employment, and that re-entry may be an important part of the work experience of older Americans.Economics of Aging, Partial Retirement, Bridge Jobs, Gradual Retirement

Production of single-domain magnetite throughout life by sockeye salmon, Oncorhynchus nerka

Although single-domain particles of biogenic magnetite have been found in different species of pelagic fishes, nothing is known about when it is synthesized, or about whether the time during life when it is produced is correlated with the development of responses to magnetic field stimuli. We have investigated production of biogenic magnetite suitable for use in magnetoreception in different life stages of the sockeye salmon, Oncorhynchus nerka (Walbaum). Sockeye salmon were chosen because responses in orientation arenas to magnetic field stimuli have been demonstrated in both fry and smolt stages of this species. We found significant quantities of single-domain magnetite in connective tissue from the ethmoid region of the skull of adult (4-year-old) sockeye salmon. The ontogenetic study revealed an orderly increase in the amount of magnetic material in the same region of the skull but not in other tissues of sockeye salmon fry, yearlings and smolts. The physical properties of this material closely matched those of magnetite particles extracted from the ethmoid tissue of the adult fish. We suggest that single-domain magnetite particles suitable for use in magnetoreception are produced throughout life in the ethmoid region of the skull in sockeye salmon. Based on theoretical calculations, we conclude that there are enough particles present in the skulls of the fry to mediate their responses to magnetic field direction. By the smolt stage, the amount of magnetite present in the front of the skull is sufficient to provide the fish with a magnetoreceptor capable of detecting small changes in the intensity of the geomagnetic field. Other tissues of the salmon, such as the eye and skin, often contained ferromagnetic material, although the magnetizations of these tissues were usually more variable than in the ethmoid tissue. These deposits of unidentified magnetic material, some of which may be magnetite, appear almost exclusively in adults and so would not be useful in magnetoreception by young fish. We suggest that tissue from within the ethmoid region of the skull in pelagic fishes is the only site yet identified where magnetite suitable for use in magnetoreception is concentrated

Self-Employment Transitions among Older American Workers with Career Jobs

What role does self-employment play in the retirement process? Older Americans are staying in the labor force longer than prior trends would have predicted and many change jobs later in life. These job transitions are often within the same occupation or across occupations within wage-and-salary employment. The transition can also be out of wage-and-salary work and into self employment. Indeed, national statistics show that self employment becomes more prevalent with age, partly because self employment provides older workers with opportunities not found in traditional wage-and-salary jobs, such as flexibility in hours worked and independence. This paper analyzes transitions into and out of self employment among older workers who have had career jobs. We utilize the Health and Retirement Study, a nationally-representative dataset of older Americans, to investigate the prevalence of self employment among older workers who made a job transition later in life and to explore the factors that determine the choice of wage-and-salary employment or self employment. We find that post-career transitions into and out of self employment are common and that health status, career occupation, and financial variables are important determinants of these transitions. As older Americans and the country as a whole face financial strains in retirement income in the years ahead, self employment may be a vital part of the pro-work solution.Retirement, Retirement Transitions, Self Employment

Bayesian modeling of pilot belief and visual misperception in helicopter overland navigation

This paper aims to provide a framework to model human belief and misperception in helicopter overland navigation. Helicopter overland navigation is known to be a challenging cognitive task, and understanding the cognitive processes associated with it is non-trivial. Twelve military personnel participated in the study and statistical analysis showed that their gaze parameters can be predicted by their level of expertise. Some pilots showed common visual misperception during the navigation task, which can be explained by the following errors: 1) confusion between inference and evidence, 2) incorrect mutually exclusive assumptions on the data, and 3) biased sampling. Simulation results on two cases observed in the experiments are given. Quantitative differences in dynamic perceptions between a Bayesian agent and misperceiving humans are presented with the suggested modeling framework