No description available.

The number of older adults is estimated to double from 52 million to 95 million by 2060. Approximately 80-85% of older adults are diagnosed with a chronic health condition. Many of these chronic health conditions are influenced by diet and exercise, suggesting improved diet and eating behaviors could improve health-related outcomes. One factor that might improve dietary habits in older adults is food-related inhibitory control. We tested whether food-related inhibitory control, using behavioral (response time, error rate) and scalp-recorded event-related potential (ERP; N2 and P3 components) measures of food-related inhibitory control differed between younger and older adults over age 55. Fifty-nine older adults (31 females [52.5%], Mage=64, SDage=7.5) and 114 younger adults (82 females [71.9%], Mage=20.8) completed two go/no-go tasks, one inhibiting to high-calorie stimuli and one inhibiting to low-calorie stimuli, while electroencephalogram (EEG) data were recorded. Older adults had slower overall response times than younger adults, but this was not specific to either food task. There was not a significant difference for accuracy between younger and older adults, but both groups' accuracy and response times were significantly improved during the high-calorie task than the low-calorie task. For both the N2 and P3 ERP components, younger adults had greater amplitude than older adults, but this effect was not food-specific, reflecting overall generalized lower inhibitory processing in older adults. Of note, P3 amplitude for the younger adults demonstrated a specific food-related effect (greater P3 amplitude for high-calorie no-go) that was not present for older adults. Findings support previous research demonstrating age related differences in inhibitory control though those differences may not be specific to inhibiting to high-calorie foods.

Many claim that, with regard to transportation infrastructure, only partnerships between public and private entities, which draw on the strengths of both, can achieve the goals of enhancing operational efficiency, increasing service delivery, improving asset maintenance, and stretching scarce federal, state, and local tax dollars. While some completed public-private partnership (P3) agreements on existing toll roads in the United States have seen a measure of success, others have raised critical questions pertaining to the true costs and benefits associated with these agreements for all stakeholders. Of particular concern is an apparent reliance on monetary calculations alone to determine toll road lump sum value. This primary focus on monetary considerations appears to neglect a number of non-monetary variables associated with potential costs and benefits. Four distinct groups of variables to consider in the decision process are presented in the dissertation: Monetary, Monetizable, Quantitative, and Qualitative. The last two groups represent variables of a non-monetary nature, which can reflect the much larger stewardship role that government plays in our society. The objectives of this research are twofold: to formulate a conceptual framework for a decision support system (DSS); and to propose an approach, including a set of analytical methods, that assesses the costs, benefits and other impacts associated with alternative P3 strategies. The primary user of the conceptual framework is identified as the public sector decision maker who has been asked to make recommendations regarding different strategies of toll road operation. Two analytical methods are presented. The first uses cash flow diagrams to calculate the net present value (NPV) for each of three core P3 strategies. The second, weighs the relative importance of quantitative and qualitative (non-monetizable) variables. When used as part of a sevenstep process, these two analytical methods help create a decision support system framework that provides stakeholders with a more complete analysis of the costs and benefits associated with the P3 toll road decision process.

Acute aerobic exercise exerts a small beneficial effect on cognition. Much of the research to date has focused on cognitive changes following a bout of exercise, while little is currently known about changes in cognitive performance during exercise. The limited research that has been conducted suggests either positive, negative, or no effects on cognitive performance during exercise. Thus, the primary purpose of this study was to examine the effects of low-intensity cycling on cognitive function in college-aged students, indexed by response accuracy, reaction time, P3 amplitude, and P3 latency. Twenty-seven (Mage = 22.9 ± 3.0 years old) college-aged individuals were counterbalanced into low-intensity exercise (EX) and seated control (SC) conditions. During each condition, participants completed a 10-minute resting baseline period, 20 minutes of either sustained cycling or seated rest, and a 20-minute recovery period. Primary outcomes were assessed at 10-minute intervals (5 blocks total) throughout each condition via a modified oddball task. Across time blocks, both conditions exhibited faster reaction times on frequent trials but reduced accuracy to rare trials, suggesting a speed-accuracy tradeoff. There were no differences between conditions in P3 latency whereas a significant reduction in P3 amplitude was observed during the 20-minute exercise period compared to the control condition. Taken together, the results suggest that exercise at lower doses may have minimal influence on behavioral outcomes of cognitive performance but may impact more basic measures of brain function. Information gathered from this study may aid in the development of appropriate exercise prescriptions for populations looking to specifically target cognitive function deficits.

No description available.

No description available.

Executive functions (EFs) are foundational skills that predict academic success and develop rapidly between 3-6 years of age. By kindergarten entry, low socioeconomic status (SES) children have worse EF compared to their high SES peers. However, the nature and origins of these emerging performance gaps have not been systematically assessed. Further, little is known about the neural underpinnings of behavioral EF differences. This project assessed behavioral and neural EF measures in a socioeconomically diverse sample of children aged 4.5 to 5.5 years (N=121). The aims were to examine (1) how SES relates to multiple dimensions of EF, (2) contextual factors that may buffer EF from the impact of SES, and (3) how SES relates to neural EF processing. In study 1, I hypothesized that lower SES children would have worse EF; would especially struggle on harder working memory trials; and would show a steeper decline in performance over time compared to higher SES peers. As hypothesized, lower SES related to overall poorer EF (inhibitory control and working memory tasks). Contrary to expectations, there were no SES differences on holding two items in working memory, but lower SES children had poorer accuracy than higher SES peers when asked to remember just one item. Further, all children’s accuracy declined over time, regardless of SES. Study 2 used a bioecological approach to assess factors that may buffer children from adverse consequences of SES on EF. As hypothesized, results suggest that neighborhood quality has a buffering effect, as there was no relation between SES and child EF in low chaos neighborhoods. In high chaos neighborhoods, lower SES related to poorer EF. Study 3 examined how specific aspects of SES related to electrophysiological EF processing. As hypothesized, on an inhibitory control task, higher household income related to larger P3b amplitudes, indexing inhibition and attention allocation processes. This suggests that children from higher income families may show more mature neural processing. Unexpectedly, parent education did not relate to P3b amplitudes. Taken together, results highlight the importance of using multi- method approaches at different levels of analysis to tease apart the complexity of SES-EF relations in early childhood.

Over roughly the last three decades, governments worldwide have implemented public private partnerships (P3s) to mobilize both private funds and public resources to develop transportation infrastructure, which has provided private entities contemporary opportunities to design, finance, construct, operate and maintain these important assets. Typically, P3s are large and complex undertakings that involve and impact many stakeholders, including public officials, financiers, builders, business owners and taxpaying citizens. Consequently, their efficacy depends – to a great extent – on how well they meet the interests of this array of stakeholders. Hence, effective assessment of P3s is crucial to determine whether these infrastructure initiatives and project outcomes satisfy these stakeholders' interests throughout a P3's life-cycle. Researchers and practitioners have considered various aspects of P3s when considering their performance. In general, the current research landscape related to P3 performance includes two major areas: (1) the identification and implementation of critical success factors (CSFs) and key performance indicators (KPIs), and (2) the development of frameworks that conceptualize approaches to measure P3 performance. Numerous studies have focused on CSFs that are the "ingredients" of effective P3s. More recent studies have emphasized KPIs that are metrics to assess them. Alternatively, some research has taken a life-cycle approach to propose approaches for P3 evaluation that are more comprehensive than assessments of P3 delivery time and cost. While this research has produced useful insights, limited emphasis has been placed on assessing P3 performance comprehensively and beyond the public and private sector dichotomy. Therefore, this research develops a framework that identifies and assesses key stakeholder interests in P3s as a means to characterize their performance. Subsequently, this framework was employed in a case study of four P3 projects to evaluate how well these cases met stakeholder expectations and ultimately performed. The research to develop the framework and conduct the case study was organized in three integrated studies. The first study employed a systematic literature review of CSFs and KPIs where the extant literature remains largely segmented and fragmented. Synthesis of the literature helped to identify and characterize various CSFs and KPIs and their current employment within the P3 performance domain. This led to the development of a CSF-KPI framework that integrates these factors and indicators throughout a P3 project's lifecycle. The outcome of the first study served as the foundation for the second study where the framework to assess stakeholders' interests was constructed. In this process, the second study followed a systematic approach by integrating key components to assess performance. The development process involved several key steps: (1) identification of the key stakeholders – specifically the state (elected bodies and executive agencies), investors (equity providers), producers (project service providers) and users/citizens (individuals or groups impacted by a project); (2) characterization of their principal interests; (3) selection of indicators of these interests; (4) linkage of the indicators with 11 performance dimensions ranging from project environment to revenue and operations; and (5) connection of the performance dimensions with four levels of performance: planning, project management, business, and future potential. The framework was demonstrated and substantiated using data from the I-495 Capital Beltway Express project. The application confirmed the replicability of the framework. The final study utilized the framework to evaluate P3s effectiveness in serving stakeholders goals and objectives. A multiple case study was conducted of four P3 highway projects in the United States: I-495 Capital Beltway Express, LBJ Expressway, SR 125 (South Bay Expressway), and SH 130 (5and6) to examine the extent that state, investor, producer, and user/citizen interests were fulfilled. Overall, I-495 and LBJ Expressway met stakeholder interests more effectively than SR 125 and SH 130 (5and6); these two cases had stronger planning, project management, and business performance. Notably, the I-495 case was an unsolicited (or market lead) proposal that followed a collaborative planning process to shape and define the project to meet mutual interests while the LBJ Expressway case utilized a competitive best-value procurement to generate an innovative technical solution that reduced the project's cost and footprint. Whereas SR 125 and SH 130 (5and6) experienced various issues that led to their bankruptcy; the new owners of both projects have taken steps to improve their outlook. Overall, the research deepens understanding of the factors that impact stakeholder interests and their expectations of P3s, presents a holistic framework for P3 assessments, and provides evidence of how well multiple P3s performed, moving beyond conceptual frameworks that are currently found in the literature. / Doctor of Philosophy / Public-Private Partnerships (P3s) have been adopted extensively to facilitate the development of transportation infrastructure. The need for more efficient and effective P3 projects makes performance assessment increasingly important, especially with respect to stakeholder interests and expectations. Also, effective and efficient assessment of P3 performance is crucial to determine whether this infrastructure development strategy meets owners and stakeholders needs throughout the P3 project lifecycle. The absence of an effective and comprehensive approach to evaluate P3 performance can result in reliance on anecdotal evidence, which may inaccurately portray the outcomes of these projects. While numerous studies have examined multiple facets of P3s over the last two decades, limited emphasis has been placed on comprehensively assessing their performance. Consequently, the purpose of this research is to advance the state of knowledge of P3 project performance in the transportation sector. To realize this purpose, this dissertation performed three integrated studies. The first study examined the current literature to identify factors that influence P3 outcomes and metrics that measure them. The second study developed a performance assessment framework, which captures various phases of a project's life cycle and considers the perspectives and objectives of the range of stakeholders involved in or impacted by P3s. Further, the framework was demonstrated and substantiated using data from the I-495 Capital Beltway Express project. Finally, the third study examined four cases in the US market – I-495, LBJ Expressway, SR 125 (South Bay Expressway), and SH 130 (5and6) – to examine to what extent state, investor, producer, and user/citizen interests were fulfilled. The case study illustrated that I-495 and LBJ Expressway met stakeholder interests more effectively than SR 125 and SH 130 (5and6); I-495 and LBJ Expressway fulfilled their implementation, financial and service expectations whereas SR 125 and SH 130 (5and6) experienced implementation issues and financial distress. Overall, these studies support improved understanding of the factors that impact stakeholder interests in P3s and provide evidence of how well four P3s projects performed over time.

Befunde zu Einflüssen genetischer Variation auf Temperamentsunterschiede und die Entwicklung psychiatrischer Störungen haben in den letzten Jahren bedeutende Beiträge zum eingehenderen Verständnis neurobiologischer Grundlagen von Verhaltensunterschieden geleistet. Eine der am eingehendsten untersuchten genetischen Variationen ist ein Polymorphismus des Dopamin-D4-Rezeptor-Gens (DRD4 Exon III). Nichtsdestoweniger ist seine funktionelle und verhaltenswirksame Rolle bisher weitgehend unklar: Zwar wurden bestimmte Varianten des Polymorphismus mit einer höheren Ausprägung in der Temperamentsdimension Novelty Seeking in Verbindung gebracht, Nachfolgeuntersuchungen erbrachten jedoch inkonsistente Resultate. Angesichts der methodischen und demografischen Heterogenität der einzelnen Studien war es das Anliegen zweier erster Studien der Dissertation, die Ursprungsbefunde möglichst exakt zu replizieren. Während in einer Voruntersuchung bei 136 Studierenden signifikant höhere Werte in Novelty Seeking bei Vorliegen des DRD4 Exon III 7-Repeat-Allels bzw. des 4/7-Genotyps festgestellt wurde, ergaben sich in Studie I, in der 276 Personen der selben Population mit der selben Methodik untersucht wurden, keinerlei Effekte des Polymorphismus. Auch anhand von Meta-Analysen ist gegenwärtig davon auszugehen, dass derzeit keine ausreichende empirische Grundlage für einen Haupteffekt von DRD4 Exon III auf Novelty Seeking vorliegt. Allerdings stellt ein einzelner Polymorphismus nur einen von vielen endogenen und exogenen Einflussfaktoren auf Temperamentsunterschiede dar, und inzwischen liegen auch Befunde zu Interaktionseffekten von DRD4 Exon III mit weiteren Polymorphismen vor. Derartigen Interaktionen wurde in Studie II nachgegangen, bei der für die Stichprobe aus Studie I zusätzlich zwei weitere genetische Polymorphismen genotypisiert wurden, die direkt oder indirekt die Dopamin-Funktion beeinflussen (COMT, 5-HTTLPR). In Studie II konnten die Ergebnisse einer vorhergehenden Arbeit repliziert werden, die einen Effekt des DRD4 Exon III 7-Repeat-Allels nur für bestimmte Genotyp-Gruppierungen der anderen beiden Polymorphismen zeigte. Zudem kann anhand der Befunde eine Abhängigkeit des Effektes von DRD4 Exon III von tonischen Dopamin-Niveaus vermutet werden. Ein neuerer Ansatz für die Aufklärung der funktionellen Rolle genetischer Variation geht davon aus, dass die relativ geringen Effekte von Polymorphismen auf endophänotypischer Ebene, also der Ebene etwa psychophysiologischer Maße wie dem EEG, möglicherweise besser erfassbar sind als auf Fragebogen-Ebene. Daher wurde in Studie III der Einfluss des DRD4 Exon III Polymorphismus auf einen Endophänotyp der Responsivität gegenüber Neuheit unter Berücksichtigung tonischer Dopamin-Niveaus untersucht. Als ein plausibler solcher Endophänotyp wurde die Novelty P3 des akustisch evozierten Potenzials im EEG in einer Stichprobe von 72 Personen im Hinblick auf ihre Modulation durch DRD4 Exon III untersucht. Tonische Dopamin-Niveaus wurden über die spontane Lidschlagrate als einem indirekten Indikator der Dopamin-Aktivität erhoben. Es zeigten sich keine Haupteffekte von DRD4 Exon III oder Lidschlagrate auf die akustisch evozierte Novelty P3. Es fand sich hingegen eine signifikante Interaktion der beiden Faktoren: Unter den Personen mit niedriger Lidschlagrate (=niedrigen tonischen Dopamin-Niveaus) zeigten Personen mit dem DRD4 Exon III 4/7-Genotyp eine signifikant höhere Novelty P3 in Antwort auf abweichende Reize als Personen mit dem 4/4-Genotyp. Dieses Ergebnis legt nahe, dass der Effekt von DRD4 Exon III auf die Verarbeitung abweichender Information von tonischen Dopamin-Niveaus abhängig ist. Insgesamt eröffnen die Resultate der Dissertation auch weiter gehende Erklärungsmöglichkeiten für Befunde etwa zu einer Assoziation von DRD4 Exon III mit Aufmerksamkeitsdefizit/Hyperaktivitätsstörung sowie für Zusammenhänge zwischen kognitiven, motivationalen und temperamentsmäßigen Verhaltenstendenzen.

Abstract To be able to acquire, produce, and comprehend language, precise central auditory processing (CAP), neural processes utilized for managing auditory input, is essential. However, the auditory environments are not always optimal for CAP because noise levels in children’s daily environments can be surprisingly high. In young children, CAP and its developmental trajectory as well as the influence of noise on it have scarcely been investigated. Event-related potentials (ERPs) offer promising means to study different stages of CAP in small children. Sound processing, preattentive auditory discrimination, and attention shifting processes can be addressed with obligatory responses, mismatch negativity (MMN), and novelty P3 of ERPs, respectively. In this thesis the developmental trajectory of CAP from 2 to 4 years of age as well as noise-induced changes on it, were investigated. In addition, the feasibility of the multi-feature paradigm with syllable stimuli and novel sounds in children was evaluated. To this end, obligatory responses (P1, N2, and N4) and MMNs for consonant, frequency, intensity, vowel, and vowel duration changes, as well as novelty P3 responses, were recorded in a silent condition and with babble noise using the multi-feature paradigm. The participants were voluntary, typically developing children. Significant P1, N2, N4, and MMN responses were elicited at both ages. Also a significant novelty P3, studied at the age of 2 years, was found. From 2 to 4 years, the P1 and N2 latencies shortened. The amplitudes of N2, N4, and MMNs increased and the increment was the largest at frontal electrode locations. During noise, P1 decreased, N2 increased, and the latency of N4 diminished as well as MMNs degraded. The noise-induced changes were largely similar at both ages. In conclusion, the multi-feature paradigm with five syllable deviant types and novel sounds was found to be an appropriate measure of CAP in toddlers. The changes in ERP morphology from 2 to 4 years of age suggest maturational changes in CAP. Noise degraded sound encoding, representation forming, and auditory discrimination. The children were similarly vulnerable to hampering effects of noise at both ages. Thus, noise might potentially harmfully influence language processing and thereby its acquisition in childhood. / Tiivistelmä Kielen omaksumiselle, tuottamiselle sekä ymmärtämiselle on tärkeää tarkka keskushermostollinen kuulotiedon käsittely eli ne hermostolliset prosessit, joita käytetään kuullun aineksen käsittelyyn. Kuunteluympäristöt eivät kuitenkaan aina ole optimaalisia kuulotiedon käsittelylle, sillä melutasot lasten elinympäristöissä voivat olla hyvinkin korkeita. Pienten lasten kuulotiedon käsittelyä, sen kehittymistä ja melun vaikutusta siihen on tutkittu vähän. Kuuloherätevasteet ovat toimiva tapa tarkastella pienten lasten kuulotiedon käsittelyä eri näkökulmista. Äänen käsittelyä, esitietoista kuuloerottelua ja tarkkaavuuden siirtymistä voidaan tarkastella obligatoristen vasteiden, poikkeavuusnegatiivisuuden ja novelty P3 -vasteiden avulla. Tässä väitöskirjassa tarkastellaan kuulotiedon käsittelyn kehittymistä kahden vuoden iästä neljän vuoden ikään sekä melun vaikutusta siihen. Lisäksi arvioidaan tavuärsykkeitä ja poikkeavia ääniä sisältävän monipiirreparadigman soveltuvuutta lapsitutkimuksiin. Tutkimuksissa rekisteröitiin monipiirreparadigman avulla obligatorisia vasteita (P1, N2 ja N4); konsonantin, taajuuden, intensiteetin, vokaalin ja vokaalin keston muutokselle syntyneitä MMN-vasteita sekä novelty P3 -vasteita hiljaisuudessa ja taustamelussa. Tutkimuksen osallistujat olivat vapaaehtoisia tyypillisesti kehittyviä lapsia. Molemmilla tutkimuskerroilla P1, N2, N4 ja MMN poikkesivat merkitsevästi nollatasosta samoin kuin kaksivuotiailta tutkittu novelty P3. Kahden vuoden iästä neljään vuoteen P1- ja N2-vasteiden latenssi lyheni sekä N2, N4 ja MMN vahvistuivat, muutoksen ollessa suurinta frontaalisilla elektrodeilla. Melun aikana P1 heikkeni, N2 vahvistui ja N4-vasteen latenssi lyhentyi. Lisäksi MMN-vaste heikkeni. Melun aiheuttamat muutokset olivat samankaltaisia sekä kahden että neljän vuoden iässä. Johtopäätöksenä voidaan todeta viittä eri tavuärsyketyyppiä ja yllättäviä ääniä sisältävän monipiirreparadigman olevan toimiva menetelmä taaperoiden kuulotiedon käsittelyn tutkimiseen. Kahden ja neljän ikävuoden välillä tapahtuvat muutokset vasteissa kuvastavat kehityksellisiä muutoksia kuulotiedon käsittelyssä. Melu heikentää äänitiedon peruskäsittelyä, edustumien muodostumista ja esitietoista kuuloerottelua. Lapset olivat lähes yhtä alttiita melun vaikutuksille sekä kahden että neljän vuoden iässä. Melu voi siis haitata kielen prosessointia ja sen omaksumista.