The present work consists of an investigation on the first physical-mathematical theories applied to the study of the artificial flight with airplanes, and in particular the treatment of the problem of longitudinal stability. The minimally analytical-formal contributions of G. Cayley, A. Pénaud, O. Lilienthal, A. Zahm and the W. & O. Wright brothers are analyzed. The mathematically stronger publications of N. E. Zhukowsky, H. Bryan, F. Ferber, F. W. Lanchester, R. Soreau, P. Painlevé, G. de Bothezat and T. Von Kármán & E. Trefftz, are also studied. Also included is the study of the eminently informative contribution of E. A. Duchêne. The period analyzed covers from 1799 to 1913. / El presente trabajo consiste en una investigación crítico-histórica sobre las primeras teorías físico-matemáticas aplicadas al estudio del vuelo artificial con aeroplanos, y particularmente el tratamiento del problema de la estabilidad longitudinal. Se analizan las aportaciones mínimamente analítico-formales de G. Cayley, A. Pénaud, O. Lilienthal, A. Zahm y los hermanos W. & O. Wright. Se estudian también las publicaciones matemáticamente más sólidas de N. E. Zhukowsky, H. G. Bryan, F. Ferber, F. W. Lanchester, R. Soreau, P. Painlevé, G. de Bothezat y T. Von Kármán & E. Trefftz. Se incluye también el estudio de la aportación eminentemente divulgativa de E. A. Duchêne. El período analizado abarca desde 1799 hasta 1913. / El present treball consisteix en una investigació sobre les primeres teories físico-matemàtiques aplicades a l'estudi del vol artificial amb aeroplans, i particularment el tractament del problema de l'estabilitat longitudinal. S'analitzen les aportacions mínimament analítico-formals de G. Cayley, A. Pénaud, O. Lilienthal, A. Zahm i els germans W. & O. Wright. S'estudien també les publicacions matemàticament més sòlides de N.E. Zhukowsky, H.G. Bryan, F. Ferber, F.W. Lanchester, R.Soreau, P. Painlevé, G. de Bothezat y T. Von Kárman & E. Trefftz. S'inclou també l'estudi de l'aportació eminentment divulgativa d' E.A. Duchêne. El periode analitzat abarca des de 1799 fins 1913. / Magraner Rullan, JP. (2017). Análisis crítico-histórico de las teorías pioneras sobre la estabilidad longitudinal de los aviones (1799-1913) [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90542

Adolescence is a critical developmental period characterized by neurobiological changes and exposure to novel experiences. According to the Center for Disease Control, approximately 70% of adolescent deaths in the United States are due to risky behaviors such as reckless driving and risky sexual behavior (Kann et al., 2016). In order to better understand what drives adolescent risk-taking, the current studies utilized an interdisciplinary approach, which combined behavioral economic models and functional magnetic resonance imaging (fMRI) to understand neurobehavioral mechanisms of risky choice. The focus of the current studies is to investigate the extent to which neurobehavioral mechanisms of risky choice change across adolescence, and to identify individual differences that explain real-world risky behavior. In Study 1, we show that behavioral sensitivity to risk and neural correlates of risk processing change across a critical period of adolescence. Importantly, our results indicate that individual differences in neural, not behavioral risk sensitivity are predictive of future engagement in health risk behaviors. In Study 2, we examined the relation between inter-individual differences in adolescent expectations of valued rewards and self-reported risky behavior using an adapted behavioral economic model. Implications and future directions for adolescent risky decision-making are discussed. / Ph. D. / According to the Center for Disease Control, approximately 70% of adolescent deaths in the United States are due to risky behaviors such as reckless driving and risky sexual behavior (Kann et al., 2016). In order to prevent and reduce such risk-taking behavior during adolescence, it is essential to improve our current understanding of the mechanisms contributing to risky decision-making. One promising mechanism that may be critical in guiding adolescents either toward or away from risky behavior is the extent to which adolescents are sensitive to the risk or likelihood of receiving potential rewarding outcomes. To this end, the current work leveraged the used of a longitudinal design with an interdisciplinary approach that combined the use of behavioral economic models, functional magnetic resonance imaging (fMRI), and developmental psychological theory to better understand how adolescents develop risk sensitivity at both the behavioral and neural levels. Importantly, our results in Study 1 indicated that individual differences in neural, not behavioral risk sensitivity are predictive of future engagement in health risk behaviors. In Study 2, we used an adapted behavioral economic model to identify individual differences in adolescent expectations of valued rewards, and assess the relation of these differences to self-reported risky behavior. This research illuminates the critical role that neurobehavioral risk sensitivity might play during risky decision-making, which may have implications for the prevention and amelioration of adverse health risk behaviors.

During the COVID-19 pandemic, highly efficacious vaccines were developed to help stop the spread of SARS-CoV-2. The adenoviral vector-based vaccines have caused a rare but serious adverse side effect known as vaccine-induced immune thrombotic thrombocytopenia (VITT). VITT occurs 5 to 30 days after vaccine administration and is characterized by thrombocytopenia and thrombosis. VITT is caused by antibodies against platelet factor 4 (PF4), forming immune complexes that cause platelet activation. This study aims to deepen our understanding of VITT antibody characteristics by investigating anti-PF4 antibody class and subclass distribution, anti-PF4 antibody persistence, and anti-PF4 memory B cell presence in VITT patients. This will improve our understanding of VITT, and disorders caused by anti-PF4 antibodies (anti-PF4 disorders) overall. We hypothesize that anti-PF4 memory B cells cause the persistence and circulation of pathogenic anti-PF4 autoantibodies, but these antibodies change over time, losing their ability to activate platelets and cause thrombosis in VITT patients. We found that IgG is the main antibody class and IgG1 and IgG2 are the main antibody subclasses in VITT, but more work is needed to understand the roles of these antibodies. We also observe that VITT patients continue to produce platelet-activating anti-PF4 antibodies years after VITT diagnosis. These patients have not experienced any recurrent thrombosis or thrombocytopenia, possibly because they have remained on treatment and physicians remain unsure what would happen should they be taken off treatment. We could not definitively detect circulating anti-PF4 memory B cells in VITT patients, so it remains unknown whether immune memory cells play a role in keeping these antibodies around. There is a need to continue to monitor these patients to understand the long-term impacts of this disorder. This work will improve the treatment of patients suffering from anti-PF4 disorders and improve future vaccine safety and efficacy. / Thesis / Master of Health Sciences (MSc) / Vaccine-induced immune thrombotic thrombocytopenia (VITT) is caused by antibodies that bind to platelet factor 4 (PF4), reducing the number of platelets (thrombocytopenia) and forming deadly blood clots (thrombosis) within the body. Not much is known about the characteristics of VITT antibodies, so this study aims to improve understanding of VITT and anti-PF4 disorders. We found that 2 main types of antibodies were produced in VITT, but their roles remain unknown. We also monitored patients over a median of 715 days and found that some patients continued to produce VITT antibodies that can activate platelets, but we were unable to detect the cells that produce these antibodies long-term. These patients have not had recurrent thrombocytopenia or thrombosis possibly because they remain on treatment. Further monitoring and research are needed to improve our understanding of anti-PF4 disorders and provide better care for VITT patients.

Intelligent Transportation Systems (ITS), which uses modem electronics and communications technology to guide or control the operation of vehicles holds great promise for increasing the capacity of existing roads. reducing congestion and accident losses, and contributing to the ease and convenience of travel. The most sophisticated of all the ITS technologies that may ultimately yield the largest benefits is the Automated Highway Systems (AHS). The AHS approach to enhance the performance of our highways is to apply automation techniques to vehicles and roadways to increase the capacity and efficiency of existing facilities, while retaining the advantages of individual mobility. The idea is to have a system with instrumented highways and vehicles which allows the automation of the driving function. The overall objective of this research study involves the modeling and analysis of an AHS system, using a simulation tool specifically developed for this purpose. A multi-layer control system architecture that conforms to the one developed at the University of California, Berkeley, provides a framework for the micro and macroscopic modeling of the system. The focus of the system modeling is towards the lower layers of this control system architecture, involving a comprehensive modeling of the regulation and physical layers and a simple, yet realistic modeling of the functionalities of the link layer. The regulation and physical layer design incorporates a complete power train modeling of the vehicle that includes one-wheel rotational dynamics, linear vehicle dynamics, engine dynamics and actuator dynamics. / Master of Science

The purpose of the following study was to advance the science of leadership emergence by taking a process-oriented approach to understand the dyadic micro-level interacts that underlie the emergence of leader-follower relationship. While most leadership emergence research focuses mainly on attributes, behaviors, or perceptions of individuals and neglects the multi-level, temporal and contextual of the emergence leaders, this study focuses on dyads' attributes, behaviors and perceptions and considers the teams, over time, and in situ. Individuals worked together in teams over the course of four weeks to accomplish a task, and their verbal interactions were recorded and coded. Attributes of dyads and dyadic perceptions of leader-follower relationship emergence were collected. Results showed dyads that were more similar in leadership self-efficacy were more likely to engage in symmetrical types of interactions. Furthermore, the more dyads engaged in such symmetrical exchanges, the more likely they were to both see each other as leaders, than to both not see each as leaders. Contrary to expectations, no significant results were found for the effect of dyadic dissimilarity on dyadic interactions, or for the effect of complementary interactions of leader-follower relationship emergence. Implications of these findings are discussed. / Ph. D. / The purpose of this dissertation was to better understand how and why leaders and followers emerge in groups based on how they communicate with each other and what characteristics they possess. Most related research focuses mainly on the characteristics that a single person who emerges as a leader or follower posses. What makes this study unique is that the focus is not exclusively on the individual, but rather is on a pair of individuals and not just their characteristics but also their forms of communication they engage in. In addition, the pair is studied in a group, over time and in a quasi-naturalistic environment to better include temporal and contextual factors. Participants worked together in teams over the course of four weeks to accomplish a task, and they were audio recorded as they worked together. Characteristics of the pairs were measured, as was whether a leader-follower relationship formed between the pair. Results showed pairs who were more similar in the their own abilities to lead (leadership self-efficacy) were more likely to engage in a particular type of communication pattern (symmetry). Furthermore, pairs who engaged in these types of communication patterns (symmetry) were more likely to both see each other as leaders, than to both not see each as leaders. Contrary to expectations, no significant relationships were found between dissimilar pairs and patterns of communication. Implications of these findings are discussed.

No

Yes / Late life involves a variety of different challenges to well-being. This study extends and qualifies propositions drawn from the paradox of well-being in aging using 15-year longitudinal data on depressive symptoms from old and very old participants in the Australian Longitudinal Study of Ageing (Baseline N 2,087; Mage 78.69 years; range: 65–103 years; 49.40% women). We first examined age-related trajectories in depressive symptoms from young-old to oldest-old, taking into account (changes in) relevant correlates, pathology, and mortality; and, second, we investigated gender differences in these trajectories. Results revealed that age-related trajectories of depressive symptoms were predictive of mortality hazards. The unique predictive effects of both level of, and change in, depressive symptoms were independent of one another and held after taking into account education as well as changes in marital status, living arrangements, cognitive function, and illness burden. In addition, results indicated that depressive symptoms were elevated among participants suffering from arthritis, and increased with age more markedly in men than in women. In particular, the significant Age Gender interaction indicated that the gender gap in depressive symptoms reduced from young-old to old-old and reversed in very old age when men showed more depressive symptoms than women. Qualifying the paradox of well-being in aging, findings demonstrated that depressive symptoms increased from young-old to oldest-old and suggest that age-, pathology-, and mortality-related changes should be examined in concert to advance our understanding of individual differences in depressive symptom trajectories in late life.

The linear variable stability Transfer Function Simulation Model (TFSM), inspired by the United States Air Force's NF-16D Variable stability In-flight Simulator Test Aircraft (VISTA) and created by Henrik Pettersson, can simulate any desired aircraft. The TFSM represents a non-linear aircraft model with its stability parameters - a collection of gain constants, time constants, damping ratios, and natural frequencies. Stability parameters for aircraft generally fall into two uncoupled modes: longitudinal and lateral-directional. Unfortunately, flight tests using the TFSM exhibited undesired lateral-directional coupling in the longitudinal responses. An S-turn maneuver, formation flight test, and an uncontrolled simulation with an initial bank angle of 60 degrees were the foundation for the investigation to pinpoint the TFSM's errors. The flight tests and subsequent analysis showed that although this model is highly versatile, it has three fundamental problems. First, the original creation of the TFSM incorrectly assumed that the time rate of change for the pitch angle (in the local-horizontal reference frame) is equal to the body-axis pitch-rate for all flight conditions. Second, the TFSM's dynamics do not contain gravity terms. Third, the TFSM cannot generate the angular rates needed in a turn. Integrating the aircraft's pitch, roll, and yaw angles with the equations of motion for aircraft fixed the first problem. Unfortunately, resolving this issue only intensified the second two problems. The results from this thesis show that the last two problems are part of the TFSM and cannot be fixed explicitly. / Master of Science

No / This paper discusses the aspect of student support that emerged as a key component of a longitudinal study into the experiences of nurses studying through open learning in the UK. Students engaged in this study were mature learners who were practicing nurses and predominantly, but not exclusively, women. Participants perceived entering higher education as a considerable challenge.

Yes / There is a major need for longitudinal research examining the experiences of people with dementia and their primary carers, as relatively little is known about how the factors associated with capability to ‘live well’ vary over time. The main aim of the IDEAL-2 study is to investigate how and why, over time, people with dementia and their primary carers might vary in their capability to live well with dementia, whilst exploring both their use of health and care services and their unmet needs. IDEAL-2 will build on the Improving the experience of Dementia and Enhancing Active Life (IDEAL) cohort of 1547 people (who, at recruitment between July 2014 and July 2016, had mild-to-moderate dementia), and their 1283 primary carers in Great Britain. The existing cohort will be enriched with additional participants with mild-to-moderate dementia (and their primary carers where available and willing) from the following groups: people with rarer forms of dementia, and/or those who are ≥90 years or < 65 years of age at time of recruitment. We will assess the primary outcome, capability to live well with dementia, and the factors influencing it using questionnaires at yearly intervals for 3 years. Additionally, we will seek to link the cohort data with administrative data to obtain information about health service use. Some participants will be invited for in-depth face-to-face interviews. The cohort study will be supplemented by linked research focusing on: the co-production of new measures of living well; including the perspectives of people with advanced dementia living in residential care settings; including people with dementia from black, Asian, and minority ethnic groups; and understanding the experience of people living with undiagnosed dementia. IDEAL-2 will provide evidence about the key indicators of, and factors associated with, living well over the course of dementia and how these differ for particular subgroups. It will tell us which combinations of services and support are most beneficial and cost-effective. Moreover, the IDEAL-2 study will gather evidence from underresearched groups of people with dementia, who are likely to have their own distinct perceptions of living well. / Alzheimer’s Society (grant number 348 (AS-PR2–16-001)). The University of Exeter is the sponsor of this study.