Organic bioelectronics develops electronic devices at the interface with living systems using organic electronic materials. These devices can identify various chemical species and regulate the operation of individual cells, tissues, or organs. A famous organic bioelectronic device is the organic electrochemical transistor (OECT), a highly versatile circuit component that has been used in applications spanning from biosensing to neuromorphic computing. OECTs can be operated in aqueous electrolytes and use organic mixed ionic-electronic conductors (OMIECs) in their channel (and sometimes as gate electrode coating) that can transport electronic and ionic charges, making them ideal for bridging biological systems and silicon-based electronic devices. Electron-transporting (n-type) OMIEC materials have received particular attention because high-performance n-type OECTs can be used to build inverters, sensors, and complementary amplifiers. However, electron transport in an aqueous and ambient environment under the application of electrical fields is a complex phenomenon that requires in situ investigation techniques. Understanding how films operate in such media can allow to construct novel sensors and eliminate the loss processes. This Ph.D. dissertation focuses on the impact of the environment, specifically oxygen, and light, on the performance of n-type OECTs and shows how to use this knowledge to develop OECT-based glucose sensors and photodetectors. Chapter 1 introduces the mixed charge transport phenomenon in conjugated polymers and how to use it in OECT operation. OECT fabrication and various designs are described, setting the ground for the sensors we will show in the following chapters. The experimental procedures used to evaluate the critical figures of merit of the materials and the transistor performance are described in detail. Chapter 2 introduces how OECTs can be used to transduce biochemical binding events. When employing the OECT platform for biochemical sensing, it is essential to differentiate between the faradaic, capacitive, and potentiometric contributions to the sensor response. Understanding the underlying mechanisms is critical for optimizing performance. This chapter explains these different sensing mechanisms with literature examples. Chapter 3 compiles all experimental details relevant to the investigations presented in Chapters 4 and 5. Chapter 4 investigates the working mechanism of a novel n-type OECT-based glucose sensor relying on an enzymatic reaction. This chapter shows the oxygen reaction reactions and the importance of monitoring contact potentials during device operation to understand how detection occurs. The work unveils the role of the oxygen sensitivity of the n-type material on the sensor operation and suggests paths to improve performance. Chapter 5 explores the interactions of light with n-type OMIECs and how to utilize them to build water-compatible phototransistors. The first part of the chapter involves a characterization of the light/matter interplay of an n-type film and a demonstration of how to use it to build a photoelectrochemical transistor. The second part of the chapter expands this work to other n-type materials and assesses their light sensitivity, building a relationship between material property and device performance. Since most detection events lead to a change in the surface of materials, techniques that monitor surface roughness and profile changes in situ can be useful. Chapter 6 describes an atomic force microscopy (AFM) setup that can be used to investigate binding events and electrochemical doping and de-doping dynamics of OMIEC films. This chapter is intended to assist researchers in developing in-operando AFM procedures studying OMIEC films.

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With the advent of the personal computer, mechanistic nutrient uptake models have become widely used as research and teaching tools in plant and soil science. Three models NST 3.0, SSAND, and PCATS have evolved to represent the current state of the art. There are two major categories of mechanistic models, transient state models with numerical solutions and steady state models. NST 3.0 belongs to the former model type, while SSAND and PCATS belong to the latter. NST 3.0 has been used extensively in crop research but has not been used with woody species. Only a few studies using SSAND and PCATS are available. To better understand the similarities and differences of these three models, it would be useful to compare model predictions with experimental observations using multiple datasets from the literature to represent various situations for woody species. Therefore, the objectives of this study are to: (i) compare the predictions of uptake by the NST 3.0, SSAND, and PCATS models for a suite of nutrients against experimentally measured values, (ii) compare the behavior of the three models using a one dimensional sensitivity analysis; and (iii) compare and contrast the behavior of NST 3.0 and SSAND using a multiple dimensional sensitivity analysis approach. Predictions of nutrient uptake by the three models when run with a common data set were diverse, indicating a need for a reexamination of model structure. The failure of many of the predictions to match observations indicates the need for further studies which produce representative datasets so that the predictive accuracy of each model can be evaluated. Both types of sensitivity analyses suggest that the effect of soil moisture on simulation can be influential when nutrient concentration in the soil solution (CLi) is low. One dimensional sensitivity analysis also revealed that Imax negatively influenced the uptake estimates from the SSAND and PCATS models. Further analysis indicates that this counter intuitive response of Imax is probably related to low soil nutrient supply. The predictions of SSAND under low-nutrient-supply scenarios are generally lower than those of NST 3.0. We suspect that both of these results are artifacts of the steady state models and further studies to improve them, such as incorporating important rhizospheric effects, are needed if they are to be used successfully for the longer growth periods and lower soil nutrient supply situations more typical of woody species. / Master of Science

In order to achieve global carbon reduction targets, buildings must be designed to be energy efficient. Building performance simulation methods, together with sensitivity analysis and evolutionary optimization methods, can be used to generate design solution and performance information that can be used in identifying energy and cost efficient design solutions. Sensitivity analysis is used to identify the design variables that have the greatest impacts on the design objectives and constraints. Multi-objective evolutionary optimization is used to find a Pareto set of design solutions that optimize the conflicting design objectives while satisfying the design constraints; building design being an inherently multi-objective process. For instance, there is commonly a desire to minimise both the building energy demand and capital cost while maintaining thermal comfort. Sensitivity analysis has previously been coupled with a model-based optimization in order to reduce the computational effort of running a robust optimization and in order to provide an insight into the solution sensitivities in the neighbourhood of each optimum solution. However, there has been little research conducted to explore the extent to which the solutions found from a building design optimization can be used for a global or local sensitivity analysis, or the extent to which the local sensitivities differ from the global sensitivities. It has also been common for the sensitivity analysis to be conducted using continuous variables, whereas building optimization problems are more typically formulated using a mixture of discretized-continuous variables (with physical meaning) and categorical variables (without physical meaning). This thesis investigates three main questions; the form of global sensitivity analysis most appropriate for use with problems having mixed discretised-continuous and categorical variables; the extent to which samples taken from an optimization run can be used in a global sensitivity analysis, the optimization process causing these solutions to be biased; and the extent to which global and local sensitivities are different. The experiments conducted in this research are based on the mid-floor of a commercial office building having 5 zones, and which is located in Birmingham, UK. The optimization and sensitivity analysis problems are formulated with 16 design variables, including orientation, heating and cooling setpoints, window-to-wall ratios, start and stop time, and construction types. The design objectives are the minimisation of both energy demand and capital cost, with solution infeasibility being a function of occupant thermal comfort. It is concluded that a robust global sensitivity analysis can be achieved using stepwise regression with the use of bidirectional elimination, rank transformation of the variables and BIC (Bayesian information criterion). It is concluded that, when the optimization is based on a genetic algorithm, that solutions taken from the start of the optimization process can be reliably used in a global sensitivity analysis, and therefore, there is no need to generate a separate set of random samples for use in the sensitivity analysis. The extent to which the convergence of the variables during the optimization can be used as a proxy for the variable sensitivities has also been investigated. It is concluded that it is not possible to identify the relative importance of variables through the optimization, even though the most important variable exhibited fast and stable convergence. Finally, it is concluded that differences exist in the variable rankings resulting from the global and local sensitivity methods, although the top-ranked solutions from each approach tend to be the same. It also concluded that the sensitivity of the objectives and constraints to all variables is obtainable through a local sensitivity analysis, but that a global sensitivity analysis is only likely to identify the most important variables. The repeatability of these conclusions has been investigated and confirmed by applying the methods to the example design problem with the building being located in four different climates (Birmingham, UK; San Francisco, US; and Chicago, US).

Hur föräldrar samspelar med barn kan ha stor påverkan på barnets språkliga och kommunikativa utveckling. Föräldrasensitivitet och mind-mindedness är två mått som mäter föräldrars samspel. Föräldrasensitivitet mäter förälderns förmåga att uppfatta och tolka barnets signaler och mind-mindedness innefattar förälderns användande av ord som handlar om barnets mentala processer. Dessa mentaliseringsyttranden kan vara intonade eller icke-intonade utifrån situationen och barnets sinnesstämning. I vilken grad föräldrars mind-mindedness och föräldrasensitivitet påverkar olika delar av den kommunikativa utvecklingen är till stora delar fortfarande okänt. Syftet med föreliggande studie var att undersöka om föräldrasensitivitet och föräldrars mind-mindedness korrelerar med kommunikativa förmågor, om mind-mindedness och föräldrasensitivitet korrelerar med varandra samt om några könsskillnader förelåg. Materialet bestod av 35 inspelade förälder-barndyader som observerats när barnen var ca 16 månader. För att mäta föräldrasensitivitet användes lyhördhetsskalan ”Lyhördhet eller icke-lyhördhet för barnets signaler”. För att mäta mind-mindedness kodades förälder-barndyaderna samt föräldrabeskrivningar utifrån manualen för mind-mindedness av Meins och Fernyhough (2010). De kommunikativa förmågorna mättes dels genom the Swedish Early Communicative Development Inventories och dels genom the Early Social Communication Scales. Resultatet visade att det förelåg samband mellan föräldrasensitivitet och kommunikativa förmågor. Såväl språkförståelse, kommunikativa gester samt delad uppmärksamhet korrelerade med föräldrasensitivitet. Beträffande föräldrars mind-mindedness, konstaterades ett samband mellan en hög andel icke-intonade mentaliseringsyttranden och bristande förmåga till delad uppmärksamhet. Vidare framkom samband mellan mind-mindedness och föräldrasensitivitet: en förälder med hög föräldrasensitivitet använde fler intonade mentaliseringsyttranden än en förälder med låg föräldrasensitivitet. Ett motsvarande omvänt samband uppstod mellan icke-intonade mentaliseringsyttranden och en låg nivå av föräldrasensitivitet, där en icke-lyhörd förälder använde fler icke-intonade mentaliseringsyttranden. Slutligen upptäcktes en könsskillnad som innebar att föräldrar använder fler icke-intonade mentaliseringsyttranden till pojkar än till flickor. / The way a parent interacts with his or her child can have a great effect on communication and language development of the child. Maternal sensitivity and mind-mindedness are two measures used for parent-child interplay. Maternal sensitivity measures the parent’s ability to accurately perceive and interpret the child’s cues while mind-mindedness involves the parent’s use of words and comments regarding the child’s internal state. These comments can be classified as appropriate or non-attuned regarding the situation and the child’s state of mind. To what extent mind-mindedness and maternal sensitivity affect different parts of the child’s communicative development is still mainly unknown. The purpose of the present study was to investigate if maternal sensitivity and mind-mindedness co-vary with communicative abilities, if mind-mindedness and maternal sensitivity co-vary with each other, and finally, if any gender differences was present. The material of the study consisted of 35 videotaped parent-child interactions, which were observed when the children were 16 months of age. To measure maternal sensitivity, the sensitivity scale were used, “Sensitivity vs. Insensitivity to the Baby's Signals”. To measure mind-mindedness, parent-child interplay and parental interviews were coded. The child’s communicative abilities were assessed with the Swedish Early Communicative Development Inventories and with the Early Social Communication Scales. The result showed a correlation between maternal sensitivity and language comprehension, communicative gestures and joint attention. A relationship was found between mind-mindedness and parents’ using more non-attuned mental comments and children’s decreasing ability to respond to joint attention. The results also demonstrated that a sensitive parent uses more appropriate mental comments than a parent who was insensitive. A reversed relationship was found between non-attuned mental comments and a low level of maternal sensitivity, where the insensitive parent used more non-attuned mental comments. Finally, a difference in gender was found, where parents use more non-attuned comments to boys than to girls. / FAS dnr 2008-0875

Thesis (doctoral)--Technische Universiteit Eindhoven, 1999. / Originally published: Knegsel : HV Press, 1999. Includes bibliographical references and index. Online version available. http://dx.doi.org/10.1117/3.353254

Thesis (doctoral)--Technische Universiteit Eindhoven, 1999. / Originally published: Knegsel : HV Press, 1999. Includes bibliographical references and index.

A baby’s early experiences have a crucial effect on their later development and adjustment. Early maternal sensitivity is a concept which has been associated with a crucial influence on these later child outcomes, including behavioural outcomes. Results from large longitudinal population based studies have provided conflicting evidence in relation to early maternal sensitivity, particularly sensitivity to non-distress, and later child behaviour and a need for further research in this area exists. The current study investigated early maternal sensitivity and its association with later child behaviour in a UK based population sample using data from the Avon Longitudinal Study of Parents and Children (ALSPAC). The study used a subsample of 766 mother-infant pairs who had data on observed maternal responsiveness at 12 months and on child behavioural difficulties derived from the Revised Rutter Parent Scale for Preschool Children at 42 months. Data for a number of potentially confounding variables, including maternal and child-based variables were also included in the analysis. Hypotheses were tested regarding an association between lower maternal responsiveness and higher child behavioural difficulties as well as regarding associations with further behavioural subscales of the Rutter scale, including a prosocial behaviour subscale. Results were analysed using a linear regression model with adjustments for groups of confounding variables. There was no evidence to support a relationship between lower maternal responsiveness and higher behavioural difficulties at 42 months although there was suggestion of a trend in the expected direction. Similar results were found for the subscales of the Rutter scale. The conclusion is that maternal sensitivity measured in this way does not have a strong relationship with child behaviour. One interpretation of these results is that there is a need to distinguish between maternal sensitivity to non-distress and to distress and ensure that the appropriate aspect of maternal sensitivity in relation to child behavioural outcomes is assessed. Limitations of the study are discussed and the effects of potential improvements are considered.

The relationship between maternal sensitivity (MS) and child outcomes has been examined by earlier research. There is some evidence that MS plays a role in shaping temperament development in early childhood. Child temperament outcomes are a significant predictor for functioning in later life. The study is based on 952 mother-infant pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC). MS was observed at 12-months and temperament at 24-months. Linear regression was used to investigate the association between MS and temperament, adjusting for a range of confounders (temperament at 6 months, gender, SES, maternal mental health, maternal preconceptions of her child, parental conflict, gestation and maternal age). Multiple imputation was used to account for attrition. Mother-child interactions rated as “cool/moderate” were associated with more difficult temperament on the dimensions of “approach” (Coef 0.35, CI 0.09, 0.60),“rhythmicity”(Coef 0.43, CI 0.19, 0.68) and “adaptability” (Coef 0.24, CI 0.00, 0.49). The associations remained after adjusting for confounders in the imputed data set. There is evidence that maternal warmth may be influential in the development of child temperament, particularly positive affect, sociability and affect regulation. Further research is needed to replicate these findings.