Longitudinal Genetic Analysis of Plasma Lipids

The consensus from published studies is that plasma lipids are each influenced by genetic factors, and that this contributes to genetic variation in risk of cardiovascular disease. Heritability estimates for lipids and lipoproteins are in the range .48 to .87, when measured once per study participant. However, this ignores the confounding effects of biological variation measurement error and ageing, and a truer assessment of genetic effects on cardiovascular risk may be obtained from analysis of longitudinal twin or family data. We have analyzed information on plasma high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, and triglycerides, from 415 adult twins who provided blood on two to five occasions over 10 to 17 years. Multivariate modeling of genetic and environmental contributions to variation within and across occasions was used to assess the extent to which genetic and environmental factors have long-term effects on plasma lipids. Results indicated that more than one genetic factor influenced HDL and LDL components of cholesterol, and triglycerides over time in all studies. Nonshared environmental factors did not have significant long-term effects except for HDL. We conclude that when heritability of lipid risk factors is estimated on only one occasion, the existence of biological variation and measurement errors leads to underestimation of the importance of genetic factors as a cause of variation in long-term risk within the population. In addition our data suggest that different genes may affect the risk profile at different ages.

Predictors and outcomes of early motherhood in the Australian Longitudinal Study on Women's Health

Early motherhood is identified as a social problem, and having children at an early age is assumed to lead to psychological distress, welfare dependence and socioeconomic disadvantage. Analysis of responses from 9,689 young participants in the Australian Longitudinal Study on Women's Health was used to examine predictors and outcomes of early motherhood in Australia. Survey 1 (1996, aged 18 - 23) and Survey 2 (2000, aged 22 - 27), were used to categorize women as Childless, Existing Mothers (before Survey 1) and New Mothers (became mothers before Survey 2). Multivariate logistic regressions provided comparisons on sociodemographics, gynaecological variables, psychological wellbeing and health behaviours. Survey 1 data show that Existing Mothers experience socioeconomic disadvantages and unhealthy lifestyles. However, those who will go on to become mothers earlier than their peers already experience similar disadvantages. Further, the Survey 2 data show that, when these pre-existing disadvantages are controlled for, the additional deficits experienced by early mothers are relatively minor. Social disadvantage predisposes women to become mothers early, and to adopt unhealthy behaviours. However, young Australian women cope well with the challenges of early motherhood. In the longer term, unhealthy lifestyles and low education may lead to ill health and disadvantage, but early motherhood is not the initiator of this trajectory.

Quality improvement in professional local government services : a longitudinal study

This sustained longitudinal study, carried out in a single local authority, investigates the implementation of a Total Quality Management (TQM) philosophy in professional local government services. At the start of this research, a large majority of what was written about TQM was polemical and based on limited empirical evidence. This thesis seeks to provide a significant and important piece of work, making a considerable contribution to the current state of knowledge in this area. Teams from four professional services within a single local authority participated in this research, providing the main evidence on how the quality management agenda in a local authority can be successfully implemented. To supplement this rich source of data, various other sources and methods of data collection have been used: 1) Interviews were carried out with senior managers from within the authority; 2) Customer focus groups and questionnaires were used; 3) Interviews were carried out with other organisations, all of which were proponents of a TQM philosophy. A number of tools have been developed to assist in gathering data: 1) The CSFs (critical success factors) benchmarking tool; 2) Five Stages of Quality Improvement Model. A Best Practice Quality Improvement Model, arising from an analysis of the literature and the researcher's own experience is proposed and tested. From the results a number of significant conclusions have been drawn relating to: 1) Triggers for change; 2) Resistance of local government professionals to change 3) Critical success factors and barriers to quality improvement in professional local government services; 4) The problems associated with participant observation and other methodological issues used.

A longitudinal study of Chinese managerial behaviour:an inside view of decision-making under the economic reform

This research compared decision making processes in six Chinese state-owned enterprises during the period 1985 to 1988. The research objectives were: a) To examine changes in the managerial behaviour over a period of 1985 to 1988 with a focus on decision-making; b) Through this examination, to throw light on the means by which government policies on economic reform were implemented at the enterprise level; c) To illustrate problems encountered in the decentralization programme which was a major part of China's economic reform. The research was conducted by means of intensive interviews with more than eighty managers and a survey of documents relating to specific decisions. A total of sixty cases of decision-making were selected from five decision topics: purchasing of inputs, pricing of outputs, recruitment of labour, organizational change and innovation, which occurred in 1985 (or before) and in 1988/89. Data from the interviews were used to investigate environmental conditions, relations between the enterprise and its higher authority, interactions between management and the party system, the role of information, and effectiveness of regulations and government policies on enterprise management. The analysis of the data indicates that the decision processes in the different enterprises have some similarities in regard to actor involvement, the flow of decision activities, interactions with the authorities, information usage and the effect of regulations. Comparison of the same or similar decision contents over time indicates that the achievement of decentralization varied according to the topic of decision. Managerial authority was delegated to enterprises when the authorities relaxed their control over resource allocation. When acquisition of necessary resources is dependent upon the planning system or the decision matter is sensitive, because it involves change to the institutional framework (e.g. the Party), then a high degree of centralization was retained, resulting in a marginal change in managerial behaviour. The economic reform failed to increase decision efficiency and effectiveness of decision-making. The prevailing institutional frameworks were regarded as negative to the change. The research argues that the decision process is likely to be more contingent on the decision content than the organization. Three types of decision process have been conceptualized, each of them related to a certain type of decision content. This argument gives attention to the perspectives of institution and power in a way which facilitates an elaboration of organizational analysis. The problems encountered in the reform of China's industrial enterprises are identified and discussed. General recommendations for policies of further reform are offered, based on the analysis of decision process and managerial behaviour.

The role of self-regulation in developing leaders:a longitudinal field experiment

A longitudinal field experiment examined a leader self-regulation intervention in teams engaged in a Business Strategy Module (BSM) of a University course. The BSM, which is an integral part of the degree programme, involved teams of four or five individuals, under the direction of a leader, working on a (simulated) car manufacturing task over a period of 24. weeks. Various aspects of team performance contributed towards module assessment. All leaders received multi-source feedback of leader task-relevant capabilities (from the leader, followers and module tutor). Leaders were randomly allocated into a self-regulation intervention (15 leaders, 46 followers) or control (25 leaders, 109 followers) conditions. The intervention, which was run by an independent coach, was designed to improve leaders' use of self-regulatory processes to aid the development of task-relevant leadership competencies. Survey data was collected from the leaders and followers (on three occasions: pre- and two post-test intervention), team financial performance (three occasions: post-test) and a final team report (post-test). The leader self-regulation intervention led to increased followers' ratings of leader's effectiveness, higher team financial performance and higher final team grade compared to the control (non-intervention) condition. Furthermore, the benefits of the self-regulation intervention were mediated by leaders' attaining task-relevant competencies. © 2013.

Sustaining local manufacturing: a longitudinal study of Swedish companies

This paper reports an investigation of local sustainable production in Sweden aimed at exploring the factors contributing to survival and competitiveness of manufacturing. Eight companies were studied on two occasions 30 years apart; in 1980 and 2010. To provide a valid longitudinal, perspective a common format for data collection was used. As a framework for data collection and analysis the DRAMA methodology was employed (Bennett and Forrester, 1990). There are a number of results reported in detail concerning long term competitiveness and sustainability of manufacturing companies.

Study of the longitudinal distribution of power generated in a random distributed feedback Raman fibre laser with unidirectional pumping

The longitudinal distribution of the Stokes-component power in a Raman fibre laser with a random distributed feedback and unidirectional pumping is measured. The fibre parameters (linear loss and Rayleigh backscattering coefficient) are calculated based on the distributions obtained. A numerical model is developed to describe the lasing power distribution. The simulation results are in good agreement with the experimental data. © 2012 Kvantovaya Elektronika and Turpion Ltd.

Effective forms of market orientation across the business cycle:a longitudinal analysis of business-to-business firms

Macroeconomic developments, such as the business cycle, have a remarkable influence on firms and their performance. In business-to-business (B-to-B) markets characterized by a strong emphasis on long-term customer relationships, market orientation (MO) provides a particularly important safeguard for firms against fluctuating market forces. Using panel data from an economic upturn and downturn, we examine the effectiveness of different forms of MO (i.e., customer orientation, competitor orientation, interfunctional coordination, and their combinations) on firm performance in B-to-B firms. Our findings suggest that the impact of MO increases especially during a downturn, with interfunctional coordination clearly boosting firm performance and, conversely, competitor orientation becoming even detrimental. The findings further indicate that both the role of MO and its most effective forms vary across industry sectors, MO having a particularly strong impact on performance among B-to-B service firms. The findings of our study provide guidelines for executives to better manage performance across the business cycle and tailor their investments in MO more effectively, according to the firm's specific industry sector.

Novel ageing-biomarker discovery using data-intensive technologies

Ageing is accompanied by many visible characteristics. Other biological and physiological markers are also well-described e.g. loss of circulating sex hormones and increased inflammatory cytokines. Biomarkers for healthy ageing studies are presently predicated on existing knowledge of ageing traits. The increasing availability of data-intensive methods enables deep-analysis of biological samples for novel biomarkers. We have adopted two discrete approaches in MARK-AGE Work Package 7 for biomarker discovery; (1) microarray analyses and/or proteomics in cell systems e.g. endothelial progenitor cells or T cell ageing including a stress model; and (2) investigation of cellular material and plasma directly from tightly-defined proband subsets of different ages using proteomic, transcriptomic and miR array. The first approach provided longitudinal insight into endothelial progenitor and T cell ageing.This review describes the strategy and use of hypothesis-free, data-intensive approaches to explore cellular proteins, miR, mRNA and plasma proteins as healthy ageing biomarkers, using ageing models and directly within samples from adults of different ages. It considers the challenges associated with integrating multiple models and pilot studies as rational biomarkers for a large cohort study. From this approach, a number of high-throughput methods were developed to evaluate novel, putative biomarkers of ageing in the MARK-AGE cohort.

The effectiveness of workplace coaching:A meta-analysis of learning and performance outcomes; scale development; theoretical model of individual differences and longitudinal study

The extant literature on workplace coaching is characterised by a lack of theoretical and empirical understanding regarding the effectiveness of coaching as a learning and development tool; the types of outcomes one can expect from coaching; the tools that can be used to measure coaching outcomes; the underlying processes that explain why and how coaching works and the factors that may impact on coaching effectiveness. This thesis sought to address these substantial gaps in the literature with three linked studies. Firstly, a meta-analysis of workplace coaching effectiveness (k = 17), synthesizing the existing research was presented. A framework of coaching outcomes was developed and utilised to code the studies. Analysis indicated that coaching had positive effects on all outcomes. Next, the framework of outcomes was utilised as the deductive start-point to the development of the scale measuring perceived coaching effectiveness. Utilising a multi-stage approach (n = 201), the analysis indicated that perceived coaching effectiveness may be organised into a six factor structure: career clarity; team performance; work well-being; performance; planning and organizing and personal effectiveness and adaptability. The final study was a longitudinal field experiment to test a theoretical model of individual differences and coaching effectiveness developed in this thesis. An organizational sample of 84 employees each participated in a coaching intervention, completed self-report surveys, and had their job performance rated by peers, direct reports and supervisors (a total of 352 employees provided data on participant performance). The results demonstrate that compared to a control group, the coaching intervention generated a number of positive outcomes. The analysis indicated that coachees’ enthusiasm, intellect and orderliness influenced the impact of coaching on outcomes. Mediation analysis suggested that mastery goal orientation, performance goal orientation and approach motivation in the form of behavioural activation system (BAS) drive, were significant mediators between personality and outcomes. Overall, the findings of this thesis make an original contribution to the understanding of the types of outcomes that can be expected from coaching, and the magnitude of impact coaching has on outcomes. The thesis also provides a tool for reliably measuring coaching effectiveness and a theoretical model to understand the influence of coachee individual differences on coaching outcomes.

Longitudinal effects of family factors on alcohol use and alcohol-related problems among males from pre-adolescence to adulthood

The goal of this study was to examine the longitudinal effects of five family factors on alcohol use among adolescent males. The family factors included familism (family pride, loyalty, and cohesion), parent derogation (being put down by parents), parent/child communication, family alcohol problems and family drug problems. The study focused on the effects of the family factors reported by a sample of 451 White-non-Hispanic and African American males during early and mid-adolescence on (1) the intensity of alcohol use in mid-adolescence, and (2) the number of problems associated with alcohol use during the transition to young adulthood. The study also explored racial differences in the effects of the family factors. The data for this study were derived from a two-phase longitudinal epidemiologic cohort study of male and female adolescents enrolled in middle schools in Miami, FL. Data were collected at four points between 1990 and 2001. Linear and logistical regressions were used to analyze the effects of the family variables on the dependent variables. ^ The results of the analyses indicated that all of the family variables except family drug problems were statistically significant predictors of the level of alcohol use and alcohol-related problems. Familism had a moderate influence on both of the dependent variables at all data points, while parent derogation, parent/child communication and family alcohol problems were weak predictors. While the family factors varied by race, their impact on the dependent variables did not vary substantially. ^ This study had methodological shortcomings related to measurement and design that may have contributed to the weak influence of the variables. Future studies should explore possible mediating effects of these variables, and should employ more sensitive measures that are culturally appropriate. The results suggest that, since early family factors have long-term effects on children's substance-using behaviors, the family environment should be addressed in prevention and intervention efforts. ^

Step and flash imprint lithography: Fabrication of patterned media for extremely high density magnetic data storage devices

Currently the data storage industry is facing huge challenges with respect to the conventional method of recording data known as longitudinal magnetic recording. This technology is fast approaching a fundamental physical limit, known as the superparamagnetic limit. A unique way of deferring the superparamagnetic limit incorporates the patterning of magnetic media. This method exploits the use of lithography tools to predetermine the areal density. Various nanofabrication schemes are employed to pattern the magnetic material are Focus Ion Beam (FIB), E-beam Lithography (EBL), UV-Optical Lithography (UVL), Self-assembled Media Synthesis and Nanoimprint Lithography (NIL). Although there are many challenges to manufacturing patterned media, the large potential gains offered in terms of areal density make it one of the most promising new technologies on the horizon for future hard disk drives. Thus, this dissertation contributes to the development of future alternative data storage devices and deferring the superparamagnetic limit by designing and characterizing patterned magnetic media using a novel nanoimprint replication process called "Step and Flash Imprint lithography". As opposed to hot embossing and other high temperature-low pressure processes, SFIL can be performed at low pressure and room temperature. Initial experiments carried out, consisted of process flow design for the patterned structures on sputtered Ni-Fe thin films. The main one being the defectivity analysis for the SFIL process conducted by fabricating and testing devices of varying feature sizes (50 nm to 1 μm) and inspecting them optically as well as testing them electrically. Once the SFIL process was optimized, a number of Ni-Fe coated wafers were imprinted with a template having the patterned topography. A minimum feature size of 40 nm was obtained with varying pitch (1:1, 1:1.5, 1:2, and 1:3). The Characterization steps involved extensive SEM study at each processing step as well as Atomic Force Microscopy (AFM) and Magnetic Force Microscopy (MFM) analysis.

The longitudinal influence of physical activity on adolescent alcohol use

The purpose of this research was to explore the influence of physical activity on depressive symptomatology and adolescent alcohol use during an underexplored transition from middle school to high school. The study initiative is supported by the fact that research has shown a unique and simultaneous decrease in physical activity (CDC, 2010), increase in depressive symptomatology (SAMHSA, 2010) and increase in alcohol use (USDHHS, 2011) during middle adolescence. A risk and resilience framework was used in efforts to conceptualize how these variables may be inter-related. Data from waves I and II of the National Longitudinal Study of Adolescent Health (Add Health, Bearman et al., 1997; Udry, 1997) was used (N = 2,054; aged 13–15 years). The sample was ethnically and racially diverse (58.2% White, 24% African American, 11.7% Hispanic, and 6.1% other). Structural equation models were developed to test the potential influence physical activity has on adolescent alcohol use (e.g., frequency of alcohol use and binge alcohol use) and whether any of the relationship was mediated by depressive symptomatology or varied as a function of gender. Results demonstrated that there was a significant influence of structured physical activity (e.g., sports) on adolescent alcohol use. However, contrary to the proposed hypothesis, engaging in structured physical activity appeared to contribute to greater binge drinking among adolescents. Instead of demonstrating a protective feature, the findings suggest that engaging in structured physical activity places adolescents at risk for binge drinking. Furthermore, no significant relationships, positive or negative, were found for the influence of physical activity (structured and unstructured) on frequency of alcohol use. The findings regarding mediation revealed binge drinking as a mediator between physical activity (structured) and depressive symptomatology. These findings provide support for research, practice, and policy initiatives focused on developing a more comprehensive understanding of alcohol use drinking behaviors, physical activity involvement, and depressive symptomatology among adolescents, which this study demonstrates are all associated with one another. Results represent an initial step toward evaluating these relationships at a much younger age.

A longitudinal exploration of the relationship between oral reading fluency and reading comprehension achievement among a sample of diverse young learners

Exploring the relationship between early oral reading fluency ability and reading comprehension achievement among an ethnically and racially diverse sample of young learners from low-income families, attending elementary school within a large public school district in southeast Florida is the purpose of this longitudinal study. Although many studies have been conducted to address the relationship between oral reading fluency ability and reading comprehension achievement, most of the existing research failed either to disaggregate the data by demographic subgroups or secure a large enough sample of students to adequately represent the diverse subgroups. The research questions that guided this study were: (a) To what extent does early oral reading fluency ability measured in first, second, or third grade correlate with reading comprehension achievement in third grade? (b) To what extent does the relationship of early oral reading fluency ability and reading comprehension achievement vary by demographic subgroup membership (i.e., gender, race/ethnicity, socioeconomic status) among a diverse sample of students? A predictive research design using archived secondary data was employed in this nonexperimental quantitative methods study of 1,663 third grade students who attended a cohort of 25 Reading First funded schools. The data analyzed derived from the Dynamic Indicators of Basic Early Literacy Skills Oral Reading Fluency (DIBELS ORF) measure administered in first, second, and third grades and the Florida Comprehensive Assessment Test of the Sunshine State Standards (FCAT-SSS) Reading administered in third grade. Linear regression analyses between each of the oral reading fluency and reading comprehension measures produced significant positive correlations. Hierarchical regression analyses supported the predictive potential of all three oral reading fluency ability measures toward reading comprehension achievement, with the first grade oral reading fluency ability measure explaining the most significant variance in third grade reading comprehension achievement. Male students produced significant overall differences in variance when compared to female students as did the Other student subgroup (i.e., Asian, Multiracial, and Native American) when compared to Black, White, and Hispanic students. No significant differences in variance were produced between students from low and moderate socioeconomic families. These findings are vital toward adding to the literature of diverse young learners.

Three essays on a longitudinal analysis of business start-ups using the Kauffman Firm Survey

This dissertation focused on the longitudinal analysis of business start-ups using three waves of data from the Kauffman Firm Survey. ^ The first essay used the data from years 2004-2008, and examined the simultaneous relationship between a firm's capital structure, human resource policies, and its impact on the level of innovation. The firm leverage was calculated as, debt divided by total financial resources. Index of employee well-being was determined by a set of nine dichotomous questions asked in the survey. A negative binomial fixed effects model was used to analyze the effect of employee well-being and leverage on the count data of patents and copyrights, which were used as a proxy for innovation. The paper demonstrated that employee well-being positively affects the firm's innovation, while a higher leverage ratio had a negative impact on the innovation. No significant relation was found between leverage and employee well-being.^ The second essay used the data from years 2004-2009, and inquired whether a higher entrepreneurial speed of learning is desirable, and whether there is a linkage between the speed of learning and growth rate of the firm. The change in the speed of learning was measured using a pooled OLS estimator in repeated cross-sections. There was evidence of a declining speed of learning over time, and it was concluded that a higher speed of learning is not necessarily a good thing, because speed of learning is contingent on the entrepreneur's initial knowledge, and the precision of the signals he receives from the market. Also, there was no reason to expect speed of learning to be related to the growth of the firm in one direction over another.^ The third essay used the data from years 2004-2010, and determined the timing of diversification activities by the business start-ups. It captured when a start-up diversified for the first time, and explored the association between an early diversification strategy adopted by a firm, and its survival rate. A semi-parametric Cox proportional hazard model was used to examine the survival pattern. The results demonstrated that firms diversifying at an early stage in their lives show a higher survival rate; however, this effect fades over time.^