Purpose/Statement of Problem: Disorders of Consciousness (DoC) are a group of disorders encompassing Coma, Unresponsive Wakefulness Syndrome (UWS), and Minimally Conscious State. These disorders are characterized by altered or absent alertness and consciousness and inability to follow commands or participate in daily activities or function. DoC can be caused by a multitude of etiologies including trauma, stroke, tumors, metabolic disarray, and many others. Individuals with severe DoC are profoundly functionally and cognitively impaired, and frequently require extensive rehabilitation in order to return to their prior level of function. Additionally, a category has recently been discovered within the umbrella of DoC called Cognitive Motor Dissociation (CMD), in which individuals may show no outward signs of the ability to follow commands but can be seen to respond appropriately to commands when monitored by Electroencephalography (EEG). The current standard of rehabilitative care for individuals with severe DoC is minimal. There are no clear guidelines for rehabilitation of these individuals, particularly in the acute stage. Rehabilitation is often initiated once individuals are awake and able to follow commands, despite evidence that earlier intervention (particularly in the form of stimulation) may accelerate recovery. In this retrospective study, we had three primary aims and one case study. The first aim was to characterize the time frame in which a cohort of individuals with severe DoC received therapy and whether the timeframe in which they received therapy was appropriate. The second aim was to retrospectively determine which therapy and demographics factors could predict better short- and long-term outcomes. The third aim was to determine whether the presence of CMD had a mediating effect on therapy. Finally, the case study was intended to determine safety of a prospective study recruiting individuals extremely early after admission for a standardized stimulation intervention. Procedures and Methods: This study was a retrospective analysis of data from a cohort of individuals who were recruited to participate in multiple studies of consciousness in the neurological intensive care unit (NICU) in an academic medical center in New York City between 2014 and 2021, heretofore referred to as the parent study. All individuals had a severe DoC, were connected to EEG, had no previous history of brain injury, and were tested for presence of CMD. Charts were examined to determine whether individuals could have received therapy earlier. Regression modeling was used to determine the effect of various therapy factors (such as timing, volume, frequency, and therapy content) as well as demographics data on a variety of short term and long-term outcome measures. These outcome measures included scores on the Coma Recovery Scale-Revised, scores on the AM-PAC “6 Clicks” Basic Mobility and Daily Activity short forms, recovery of active participation in therapy, discharge destination, and Glasgow Outcomes Scale-Extended scores. Analyses were also performed on the individual effect of each therapy variable on the effect of CMD status, and on the overall effect of CMD status on outcomes. Results: Thirty-eight of the fifty eight (65.52%) individuals in this cohort who received therapy after the median day received for the cohort could have safely received therapy earlier in the form of a standardized stimulation protocol. Multiple therapy variables were implicated in both short- and long-term outcomes. More specifically, therapy frequency, therapy volume, CMD status, sitting at edge of bed, and age were all implicated in both short- and long-term outcomes. Therapy timing was not an independent predictor for any outcomes but was significantly associated with therapy frequency. Therapy frequency was an independent predictor of multiple outcomes including discharge destination, Basic Mobility scores, and GOS-E scores. Sitting at the edge of the bed was an independent predictor of Daily Activity Score, and all therapy variables except timing were independent predictors of change in Basic Mobility Score. CMD status had a modulatory effect on multiple therapy variables (variable based on outcome) and was an independent predictor of long-term outcomes. Conclusions: Individuals with severe DoC were an underserved population from a therapy perspective. With the current standard of care, individuals with severe DoC frequently overlooked in favor of those who are more able to participate in active therapy. Analyses performed in this study indicated that individuals with severe DoC could a.) safely receive therapy sooner, b.) benefit from increased therapy frequency and specific modes of therapy, c.) could make excellent functional progress and d.) might have performed better with therapy if they had CMD. These results indicate that individuals with severe DoC might benefit earlier and more consistent therapy to maximize their chances of functional recovery.

Network data, capturing the connections or interactions among subjects of interest, are widely used across numerous scientific disciplines. Recent years have seen a significant increase in time-varying network data, which record not only the number of interactions but also the precise timestamps when these events occur. These data call for novel analytical developments that specifically leverage the event time information. In this thesis, we propose frameworks for analyzing longitudinal/panel network data and continuous time network data. For the analysis of longitudinal network data, we introduce a semiparametric latent space model. The model consists of a static latent space component and a time-varying node-specific baseline component. We develop a semiparametric efficient score equation for the latent space parameter. Estimation is accomplished through a one-step update estimator and a suitably penalized maximum likelihood estimator. We derive oracle error bounds for both estimators and address identifiability concerns from a quotient manifold perspective. For analyzing continuous time network data, we introduce a Cox-type counting process latent space model. To accomodate the event history observations, each edge is modeled as a counting process, with intensity comprising three components: a time-dependent baseline function, an individual-level degree heterogeneity parameter, and a low-rank embedding for the interaction effects. A nuclear-norm penalized likelihood estimator is developed, and its oracle error bounds are established. Additionally, we discuss a several ongoing directions for this work.

Thesis advisor: Ina V. S. Mullis / TIMSS and PIRLS assess representative samples of students at regular intervals, measuring trends in student achievement and student contexts for learning. Because individual students are not tracked over time, analysis of international large-scale assessment data is usually conducted cross-sectionally. Gustafsson (2007) proposed examining the data longitudinally by analyzing relationships between country-level trends in background constructs and trends in student achievement. Through longitudinal analysis of international large-scale assessment data, it becomes possible to mitigate some of the confounding factors in the analysis. This dissertation extends this country-level approach to subpopulations within countries. Adapting a pseudo-panel approach from the econometrics literature (Deaton, 1985), the proposed approach creates subpopulations by grouping students based on demographic characteristics, such as gender or parental education. Following grouping, the subpopulations with the same demographic characteristics are linked across cycles and the aggregated subpopulation means are treated as panel data and analyzed through longitudinal data analysis techniques. As demonstrated herein the primary advantages of the subpopulation approach are that it allows for analysis of subgroup differences, and it captures within-country relationships in the data that are not possible to analyze at country level. Illustrative analysis examines the relationship between early literacy activities and PIRLS reading achievement using PIRLS 2001 and PIRLS 2011 data. Results from the subpopulation approach are compared with student-level and country-level cross-sectional results as well as country-level longitudinal results. In addition, within-country analysis examines the subpopulation-level relationship between early literacy activities and PIRLS reading achievement, multiple group analysis compares regression coefficient estimates between boys and girls and across parental education subgroups, and mediation analysis examines the extent that partaking in early literacy activities can explain differences between boys and girls in PIRLS reading achievement. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement and Evaluation.

In this dissertation, I examine individual decisions in occupational choice, labor supply, and health care utilization. Occupational choice decisions of female college graduates on whether to teach or not are analyzed to understand the role of fertility and relative wages using a panel estimation method. I also compare the behavioral changes in the labor force participation among teachers and non-teachers conditional on the presence of a new-born baby. Using the human capital model where a worker decides her hours of work responding to wages, and her human capital is accumulated proportional to her hours of work, I predict that the positive relationship between entry wages and post wages. Empirical evidence suggests that the shock in entry wages may be attributed to post wage differentials. I examine individuals?? choice of health insurance plan and utilization of health care services. Empirical evidence shows that there is favorable self-selection into health maintenance organizations (HMOs) plans and that HMO members use more of office-based and hospital outpatient services. It suggests ineffectiveness of HMO plans in reducing utilization.

In this dissertation, I examine individual decisions in occupational choice, labor supply, and health care utilization. Occupational choice decisions of female college graduates on whether to teach or not are analyzed to understand the role of fertility and relative wages using a panel estimation method. I also compare the behavioral changes in the labor force participation among teachers and non-teachers conditional on the presence of a new-born baby. Using the human capital model where a worker decides her hours of work responding to wages, and her human capital is accumulated proportional to her hours of work, I predict that the positive relationship between entry wages and post wages. Empirical evidence suggests that the shock in entry wages may be attributed to post wage differentials. I examine individuals?? choice of health insurance plan and utilization of health care services. Empirical evidence shows that there is favorable self-selection into health maintenance organizations (HMOs) plans and that HMO members use more of office-based and hospital outpatient services. It suggests ineffectiveness of HMO plans in reducing utilization.

Es wird untersucht, ob kritische Ereignisse (z. B. Arbeitslosigkeit) bzw. ein durch kritische Ereignisse ausgelöster finanzieller Schock die Überschuldungswahrscheinlichkeit privater Haushalte signifikant erhöhen (Schockthese). Weiters wird getestet, ob der Effekt kritischer Ereignisse durch kostensparende Handlungen abgeschwächt werden kann (Copingthese) bzw. von der finanziellen und sozialen Ausgangssituation beeinflusst ist (Vulnerabilitätsthese). Datengrundlage sind österreichische Befragungsdaten (ECHP 1995 bis 2001; EU-SILC 2004 bis 2008), auf Basis derer Panel-Regressionsmodelle geschätzt werden. Für die untersuchten kritischen Ereignisse kann kein direkter Effekt auf die Überschuldungswahrscheinlichkeit nachgewiesen werden; sehr wohl aber wirkt sich ein finanzieller Schock signifikant aus. Die Evidenz für eine Gültigkeit der Copingthese ist schwach, aber auch nach Kontrolle unbeobachteter, zeitkonstanter Faktoren stabil. Schätzungen zur Überprüfung der Vulnerabilitätsthese zeigen je nach verwendetem Vulnerabilitätsindikator unterschiedliche Ergebnisse. Die Befunde unterstreichen die Komplexität des Entstehungszusammenhanges: Überschuldung kann weder ausschließlich auf das Konsumverhalten bzw. Kosten-Nutzen-Erwägungen der Haushalte, noch ausschließlich auf exogene Schocks zurückgeführt werden.

Recent research into job insecurity (JI) features a greater tendency to undertake target group-specific investigations into the construct, in view of the growing diversity in the world of work. The present doctoral thesis focuses on a group that previous research into JI has so far failed to investigate fully, namely apprentices. The past disregard of this group is surprising, considering that young adults are at greater risk of unemployment than the average gainfully employed person (cf. de Witte, 2007). To meet the research objective of the present study, a JI tool validated by Staufenbiel et al. (2009), used to distinguish between four JI components within a 2*2 design, was modified for the target group of apprentices. In line with Borg and Elizur (1992), a differentiation was made between a cognitive and an affective JI component; furthermore, in line with Hellgren et al. (1999), quantitative JI involving the complete loss of employment was separated from qualitative JI, involving the aversive change of valued job features. In the first study, a survey was conducted amongst apprentices (a total of n = 392, from vocations requiring training in the areas of trade, crafts, industry and health care) at various vocational schools in the City of Osnabrück. Within the longitudinal design, potential antecedents and consequences of JI were gathered from these apprentices on two survey dates (T1: one year before completing the apprenticeship; T2: three to four months before completing the apprenticeship). Confirmatory analysis revealed the best fit for a two-factor model that differentiated between a cognitive and an affective JI component. Since qualitative items failed to be established on separate subcomponents within the structural analyses, as conceptually planned, these items were neglected, and further work was conducted using quantitative items only. The two-factorial structure of JI (cognitive versus affective) determined in the first study was replicated in the other two studies undertaken within the doctoral thesis. The longitudinal analyses conducted by structural equation modelling demonstrated that occupational self-efficacy and employability are the best predictors of cognitive and affective JI components, respectively. In the second study, an exhaustive survey was conducted amongst the apprentices of a large industrial group operating in the metal-working industry. These apprentices were practising various craft occupations that require training. In contrast to the preliminary study, the apprentices were at different stages of their apprenticeship at the time of the survey, enabling potential differences in levels of JI in the course of training to be determined. Furthermore, the second study focused solely on JI consequences. In addition to data provided by the apprentices, behavioural data such as absence data and the apprentices’ performance appraisals by their respective company trainer were also drawn on. The trajectory of JI in the course of the apprenticeship showed that JI was felt the least in the first year of training and the most in the penultimate year. In the third study, the focus on JI amongst apprentices was extended to the international context. To this end, around 100 wholesale trade apprentices were surveyed in each of three European countries that feature very different training systems, namely, Germany, the Netherlands and Spain. While vocational training in Germany is traditionally offered as a dual system in which apprentices attend vocational school and work at the company in roughly equal parts, practical elements are less predominant in the Netherlands and are substituted fully by full-time school education in Spain. In addition to demonstrating the psychometric adequacy of the JI tool, its metric measurement invariance for samples taken amongst apprentices from the three countries was also shown in the international comparative analyses. Furthermore, employability was established as the most significant predictor of both JI components in all three countries. All in all, the results of the doctoral thesis confirm that JI is a considerable stressor for apprentices in the national and international context. The doctoral thesis concludes with a summary of the topic’s relevance in international education policy in view of the prevailing sustained high youth unemployment. With regard to methodology, diary studies are recommended for future study designs to enable the better estimation of JI covariations over time.

Aim 1. Accelerated antiretroviral therapy (ART) initiation, including starting ART on the day of HIV diagnosis, has emerged to be one of the approaches to improve ART uptake by shortening or removing some preparatory steps before ART initiation. By doing so, accelerated ART initiation is thought to remove some structural barriers associated with ART initiation process. However, several concerns still need to be addressed, such as whether the expedited process would lead to adverse treatment outcomes after ART initiation. Searched strategy was developed using both MeSH and free text terms relevant to accelerated ART initiation (same-day, immediate, rapid). Exclusion criteria were studies that did not focus on HIV, did not involve HIV treatment, included individuals with HIV aged lower than 12, and contained non-human subjects. Additionally, we excluded articles that were case-reports, qualitative studies, systematic reviews, commentary, points of view, and conference presentations. Four electronic databases (PubMed, Embase, Web of Science, MEDLINE) were used to identify relevant studies published in English between January 2015 and December 2023. Outcomes were retention, viral suppression, pre-ART screening procedures, preferred baseline antiretroviral regimens, additional baseline medications, and adverse events after ART initiation. Two independent researchers were involved in the study selection process. Of 5,455 studies retrieved, 25 studies were included in the review (Cohen’s kappa: 0.88). Six studies reported findings from randomized controlled trials conducted in Lesotho (n=2), Haiti (n=1), South Africa (n=3), and Kenya (n=1), with one study conducted in both South Africa and Keya; 19 studies were observational cohort study from Ethiopia (n=4), West Africa (n=1), Italy (n=2), the United States (n=3), South Africa (n=3), Kenya (n=1), Rwanda (n=1), Sub-Saharan African region (n=1), the United Kingdom (n=1), Turkey (n=1), and China (n=1). The majority of the studies were conducted in urban areas (n=19). Of the 25 included studies, 19 had same-day ART initiation as the intervention or the exposure (three studies measured the time to ART initiation from the day of care engagement, and 16 studies measured it from the day of HIV diagnosis). There was heterogeneity in the pre-ART screening procedures, from relying on symptomatic screening and history assessment to using non-molecular rapid tests to help identify individuals with increased risk of clinical contraindications. Despite this, individuals with symptoms consistent with WHO stage 4 neurological diseases were not eligible for ART. Efavirenz-based ARV was the most regimen reported. The majority of PWH preferred to start ART within 7 days of HIV diagnosis or care engagement (range: 56.5%-86%). Our review suggested mixed results on retention in care and viral suppression after ART initiation, although many studies indicated potential benefits. Despite this, no study reported an association between clinical adverse events, including deaths, and accelerated ART initiation. Our review suggested that accelerated ART initiation can potentially increase ART uptake while not negatively impacting treatment outcomes in some settings. New tools in HIV treatment, such as safer drug regimens and injectable ART, may help improve PWH’s experience and reduce the burden associated with pill burden and frequent clinic visits. Aim 2. Accelerated antiretroviral therapy (ART) initiation has been proposed to address some structural barriers associated with the ART initiation process and improve ART uptake. Despite this, there has yet to be a consensus on how this approach should be implemented, especially concerning the clinical readiness screening procedures. While emerging literature has reported the clinical safety of accelerated ART, limited data are reported from Thailand. Given the heterogeneity of clinical profiles of people with HIV (PWH) in different regions, past studies may not be generalizable to Thailand. Additionally, as different screening procedures affect the time to ART initiation, we need to learn how these procedures impact treatment outcomes. Data were obtained from PWH from 10 ART facilities in six provinces (Chiang Rai, Chiang Mai, Chonburi, Ubon Ratchathani, Songkhla, and Bangkok) in Thailand between July 2017 and July 2019 and followed up until January 2021. All PWH registered in HIV care were included in the analysis, regardless of baseline clinical status. ART facilities were categorized into three models according to the hospital policy on pre-ART laboratory screening procedures: Model A did not consider any lab results at the initiation, Model B considered only CD4 count, and Model C considered other non-CD4 baseline laboratory results. Log-Poisson regression was used to assess the impact of hospital policies on adverse outcomes (deaths, ART discontinuation, loss to follow-up) at months three, six, 12, 18, and 24 after care engagement. Logistic regression was used to examine the impact of hospital policies on viral non-suppression (VNS, HIV-1 RNA>50 copies/mL) at months six, 12, and 18 after ART initiation. Multilevel mixed model was used to account for potential clustering within each hospital policy. Of 10,926 PWH in the dataset, 9,695 (88.7%) were included in this study. Among these, 68% (6,571/9,695), 13% (1,236/9,695), and 19% (1,888/9,695) were in Models A, B, and C, respectively. Both Models A and B had 2 ART facilities each, while Model C had 6 ART facilities. 54.2% (5,257/9,695) self-reported to be men who have sex with men, and the overall baseline median CD4 (IQR) was 168 (129-404) cells/mm3. Compared to Model A, the average risk ratio (95%CI) of adverse events at months three, six, 12, 18, and 24 for Model B was 1.14(1.08-1.20), 1.40(1.31-1.49), 1.19(1.10-1.27), 1.11(1.02-1.21), and 1.32(1.21-1.44), respectively, while it was 1.21(1.16-1.27), 1.76(1.67-1.85), 1.59(1.50-1.67), 1.81(1.71-1.90), and 1.98(1.88-2.10) for Model C, respectively. Of 9,695 PWH, 6,785 (70%) had a confirmed date of ART initiation; 37% (2,513/6,785), 34% (2,332/6,785), and 13% (851/6,785) PWH had information on viral load status at months six, 12, and 24 after ART initiation, respectively. Among these samples, compared to Model A, the average odds ratio (95%CI) of VNS for Model B at months six, 12, and 18 was 0.79(0.59-1.06), 1.06(0.71-1.55), and 1.47(0.49-3.58), respectively, while it was 1.01(0.77-1.32), 0.68(0.40-1.09), and 0.93(0.31-2.22) for Model C, respectively. ART facilities that considered CD4 or any other non-CD4 baseline laboratory results before starting ART had, on average, a higher likelihood of adverse outcomes after the initial care engagement visit and viral non-suppression after ART initiation than ART facilities that did not consider any baseline laboratory result. Aim 3. Clinical screening and psychosocial readiness assessments prior to antiretroviral therapy (ART) initiation are imperative to ensure clinical safety and ART adherence among people with HIV (PWH). However, multiple preparation steps and long wait times associated with ART initiation can contribute to HIV care disengagement and low ART uptake. To address some of the barriers associated with lengthy assessment process, accelerated ART initiation, an approach to start ART on or near the day of HIV diagnosis, has been proposed. Despite this, concerns with the expedited preparation process remain, especially with the PWH’s readiness to have optimal HIV care adherence. This study examined the impact of time to ART initiation on adverse outcomes after care engagement and viral non-suppression (VNS) after ART initiation among PWH in Thailand. Data were obtained from PWH from 10 ART facilities in 6 provinces (Chiang Rai, Chiang Mai, Chonburi, Ubon Ratchathani, Songkhla, and Bangkok) in Thailand between July 2017 and July 2019 and followed up until January 2021. PWH who tested negative for cryptococcal antigen test at baseline and had a confirmed date of ART initiation were included in the analysis and were categorized into three groups based on the time interval between care engagement (defined as the day that PWH first registered at an ART facility) and ART initiation: (1) same day (ART initiation upon the day of care engagement or same day), (2) 1-7 days, and (3) more than 7 days. Log-Poisson regression was used to assess the impact of time to ART initiation on adverse outcomes (deaths, ART discontinuation, and loss to follow-up) at months three, six, 12, 18, and 14 after care engagement. Logistic regression was used to examine the impact of time to ART initiation on VNS (HIV-1 RNA>50 copies/mL) after ART initiation at months six, 12, and 18 after ART initiation. Age, population, hospital policy on pre-ART screening procedures, and baseline CD4 were adjusted in the final models. Of 10,926 PWH in the dataset, 5,528 (50.6%) had complete information on the date of care engagement, negative results for the cryptococcal antigen test, and the date of ART initiation. Among these, 44.23% (2,445/5,528), 38.69% (2,139/5,528), and 17.08% (944/5,528) started ART on the day of, 1-7 days from, and more than 7 days from HIV care engagement visit, respectively. The median age (IQR) was 29 (24-36) and 61% (3,387/5,528) identified themselves as men who have sex with men. The baseline median CD4 (IQR) was 283 (162-412) cells/mm3. Compared to PWH who started ART on the day of HIV care engagement visit, the average risk ratio (RR) of adverse outcomes for those who started ART between 1-7 days at months three, six, 12, 18, and 24 was 0.73(0.60-0.89), 0.66(0.55-0.79), 0.74(0.63-0.86), 0.83(0.71-0.98), and 0.84(0.70-1.01), respectively, while it was 2.27(1.91-2.71), 2.16(1.85-2.52), 1.70(1.46-1.98), 1.93(1.65-2.25), and 2.83(2.44-3.30) for those who started ART more than 7 days, respectively. In the adjusted models, the associations from both groups became statistically non-significant, except for the more than 7 days at month 24 (adjusted RR:1.08; 95%CI:1.04-1.12). Of 5,528 PWH, 29% (1,616/55,28), 36% (1,967/5,528), and 14% (795/5,528) had information on viral load status at months six, 12, and 18 after ART initiation, respectively. Among these individuals, time to ART initiation was determined to have no impact on VNS in both crude and adjusted models. Accelerated ART initiation has the potential to improve ART uptake while maintaining optimal adherence to HIV care. However, HIV programs should recognize and respond to the diversity of needs among PWH to minimize adverse outcomes following ART initiation.

The present study aims to deliberate over a wider perspective on the topic of physical currency, assuming the global conversion to digital payment instruments affecting stakeholders at different scales alters number of aspects. The theoretical section discusses the process of transition to cashless society by identifying transformation stages and the barriers faced to undertake the shift. Subsequently, the links between factors as business environment, globalization, and shadow economy in relation to physical currency in circulation are examined by static and dynamic panel data analyses applying annual panel data for 70 countries for the period from 2013 to 2017. The conclusive inference is formulated based on outputs from the Blundell-Bond (1998) system GMM estimator. The empirical results provide significant evidence on negative relationship between business environment and physical currency in circulation and contrary positive link for shadow economy. Further, the greater impact of business environment on physical money among variables included, implies the promotion of electronic money solutions solely to be not sufficient to transit to cashless economy. We also construct transformation score ranking for the last five years to snap the transit stage among countries included in the study with...

Syftet med denna uppsats är att undersöka minimilöners effekter på ungdomssysselsättning inom Europeiska unionen (EU). De åldrar som undersöks är ungdomar (15–24), vilket vidare delas in i tonåringar (15–19) och unga vuxna (20–24). Som metod används panelregressioner med fasta effekter för 17 EU-medlemsländer (inklusive Storbritannien) med lagstadgade minimilöner under perioden 2000 till 2018. Vi finner att minimilöner har signifikanta negativa effekter på ungdomssysselsättning inom EU och att dessa effekter är mer kraftfulla för tonåringar än för unga vuxna. Med hänsyn till resultatet drar vi slutsatsen att minimilöner inom EU bör handskas med försiktighet eftersom de kan leda till mindre sysselsättning bland ungdomar. / The purpose of this thesis is to investigate the effects of minimum wages on youth employment in the European Union (EU). The main study group is youths between 15-24 which is then further divided into teenagers (15–19) and young adults (20-24). We employ panel regression methods with fixed effects for 17 EU countries (including the UK) that have statutory minimum wages during the period 2000 to 2018. We find that minimum wages have significant negative employment effects for youths in the EU and that the effects are stronger for teenagers compared to young adults. We reach a conclusion that minimum wage policies in EU countries should be handled with caution as they can lead to lower youth employment.