Optimization of Electrode Configurations for Calibration-Free, Remote Sensing of Heavy Metals in Water Using Double-Potenital Step Anodic Coulometry

Many areas around the world are known and predicted to suffer from arsenic-contaminated drinking water resulting in elevated medical issues. Current arsenic detection techniques require that a sample be taken at the site, carried to the lab, and then tested by a skilled technician, which is not practical for remote, hard to reach places. In collaboration with researchers at the University of Louisville and the University of Kentucky, we are designing an electrochemical cell for a calibration-free detection technique that can be performed remotely, eliminating the need for on-site technicians, and helping to prevent chronic arsenic poisoning. A validated and patented device was developed at the University of Louisville as a proof of concept, but the cost, electrode fabrication, and complex assembly requirements limit commercial viability and motivate this work. We are targeting electrodes that can be inkjet printed directly onto a 3D-printed polymer electrochemical cell, simplifying the manufacturing processes and substantially decreasing the costs of the device. We began by investigating the impact of a membrane separating the counter electrode from the working electrode. Then the stability and electrochemical characteristics of inkjet printed gold electrodes on plastic was evaluated through cyclic voltammetry of ferricyanide and scanning electron microscopy

Social information processing in adolescence: Gender differences and associations with depressive symptoms

There is a sharp increase in depression in girls in mid-adolescence, but we do not understand why this occurs. Cognitive theories suggest that people with depression have more dysfunctional attitudes and negative biases in social information processing (perceiving, interpreting, and remembering their social environment). In my thesis, I tested the hypothesis that these negative cognitions contribute to the gender difference in depression during adolescence. I examined whether girls have more negative biases in social information processing and dysfunctional attitudes than boys, and whether biases are associated with depressive symptoms in early and mid-adolescence. I collected data from 331 young and 268 mid-adolescents (aged 11-13 and 13-15 years). In chapter 3, I tested whether learning about social evaluation differed across genders or age groups. I then developed and validated computational models of learning about social evaluation in chapter 4. In chapter 5, I tested whether recall biases were more negative in young and mid-adolescent girls and were associated with depressive symptoms. In these chapters, I found that negative biases in learning about social evaluation and recall were associated with increased depressive symptoms in young and mid-adolescents. There was no strong evidence for gender differences in social information processing. In chapter 6, I tested whether there were gender differences in different domains of dysfunctional attitudes. I found that perfectionism was associated with more severe depressive symptoms across adolescence and girls had higher perfectionism than boys in mid-adolescence. My findings suggest that social information processing is not more negatively biased in girls than boys during adolescence, although girls may have more perfectionism than boys. Negative biases in learning about social evaluation, recall of social evaluation, and perfectionism were associated with depressive symptoms from early adolescence. These negative biases may be a risk factor for depression and present a good candidate for future longitudinal studies

Making and Characterizing Semiconducting Polymer for Organic Electronics

Advances in organic electronics are limited by the need for materials that effectively conduct both electrons and ions while also meeting other design criteria (cheap, flexible, stable, etc.) Conducting polymers are exciting candidates for platforms requiring mixed ionic-electronic conduction as they have a wide range of possibilities due to the ability to synthetically control the monomer unit. However, it is difficult to predict how the monomer properties influence the polymer film properties. In order to make functional materials, we need to better understand how the properties of the monomer (size, shape, functional groups, frontier orbital energies) will influence the resulting polymer. In this work we describe the electropolymerization and electrodeposition of poly(3-dodecylthiophene) (P3DDT), building on similar examinations of poly(3-hexylthiophene). We show that P3DDT can be electropolymerized and electrodeposited onto an ITO substrate. Correlations between the charge passed during electrodeposition and the resulting film properties (amount of electroactive polymer and polymer film morphology) are discussed. The information gained from this work provides information necessary for the design of future functional materials

Arts, Culture & the Brain: A literature review and new epidemiological analyses

In this report, we provide an overview of the current evidence on the associations between arts and cultural engagement and the brain, and we also add to this evidence, conducting our own new analyses of cohort data

Propuesta de un Manual de Procedimientos de los Servicios Administrativos de la Facultad de Ciencias e Ingenierías, UNAN-Managua, durante el período de Agosto a Diciembre del año 2015

La Facultad de Ciencias e Ingenierías corresponde a una de las nueve facultades de UNAN-Managua que cumple con el propósito de formar profesionales en las áreas de las ciencias y las ingenierías con una concepción científica, tecnológica y humanista del mundo a través de un modelo de gestión educativo, científico y técnico apoyado por la Administración de Facultad que le permite desarrollar sus actividades en un marco de legalidad y concordancia de los ejes fundamentales a seguir por la Institución. Esta Administración da origen a los procesos de planificación, organización, dirección y control de los recursos físicos asignados y para los cuales, actualmente, no existe un manual de procedimientos que permita la consulta y verificación de los pasos a considerar para el desarrollo de las gestiones fundamentales lo que ha originado retrasos e incumplimientos en la forma y tiempo de los servicios administrativos que se ejecutan. Para dar solución a la problemática planteada se obtuvo información por medio de fuentes primarias así como la búsqueda y análisis de fuentes secundarias tales como las normas y leyes que rigen a la administración de los recursos del Estado. Estos resultados se procesaron a través de herramientas como: Análisis de entrevistas en Excel, la flujogramación de acuerdo la normativa ANSI en el programa Visio, estudio del entorno de la investigación a través del FODA, entre otros. Una vez aplicada la metodología y las técnicas anteriores se obtuvieron los siguientes resultados que corresponden a los objetivos específicos: la descripción de la estructura organizacional de la Facultad de Ciencias e Ingenierías y de la Administración, la identificación de los servicios administrativos de mayor demanda, el análisis comparativo de las normas y políticas aplicables y un Manual de Procedimientos que se deben llevar a cabo para el óptimo cumplimiento de los procesos

Behind anemone lines: determining the environmental drivers influencing lagoonal benthic communities, with special reference to the anemone Nematostella vectensis.

Climate change induced sea level rise and increase in associated storms is impacting the coastal zone worldwide. Lagoons are a transitional ecosystem on the coast that are threatened with habitat loss due to ingress of seawater, though conversely this also represents an opportunity for lagoon habitat creation. It is important to quantify the spatio-temporal trends of macrozoobenthic communities and abiotic factors to determine the ecological health of lagoon sites. Such information will ensure optimal and adaptive management of these rare and protected ecosystems. This thesis examines the spatial distribution of macrozoobenthic assemblages and the abiotic and biotic factors that may determine their abundance, richness and distribution at tidally restricted urban lagoon at Poole Park on the south coast of England. The macrozoobenthic assemblages were sampled using a suction corer during a spatially comprehensive survey in November 2017, in addition to aquatic and sediment variables such as salinity, temperature, organic matter content and silt content. Species richness and density were significantly lower in areas of high organic matter and silt content, indicative of hostile conditions. There were no correlations between pelagic fauna and macrozoobenthic fauna which suggests that top-down control of macrozoobenthic species is not significant enough to influence their distribution. Salinity and temperature were spatially homogenous but macrozoobenthic assemblages indicate longer term variability; the euryhaline annelid Hediste diversicolor dominates at sample sites adjacent to surface water outflow pipes. The non-native protected Starlet Sea Anemone Nematostella vectensis was also significantly negatively correlated with organic matter and silt content. It is known to be sensitive to hypoxic-sulfidic conditions associated with high organic matter sediments. The anemone’s indiscriminate and efficient method of prey capture in high macrozoobenthic densities may disproportionately affect prey species, limiting their availability to native predators and negatively affect higher trophic levels. The anemone’s effect on native communities should be subject to further study. This thesis will serve as a baseline to compare subsequent surveys to, particularly post dredging and island construction works planned to commence in Poole Park lagoon in the late autumn of 2018

Longitudinal Associations Between Arts Engagement and Flourishing in Young Adults: A Fixed Effects Analysis of the Panel Study of Income Dynamics

There is growing evidence on the impact of arts engagement on flourishing. However, social gradients in arts engagement and flourishing may have led to an overestimation of this impact, and there is a lack of longitudinal research in young people. We aimed to test the longitudinal associations between arts engagement and flourishing in emerging adults, accounting for observed and unobserved individual characteristics. We included 3,333 participants aged 18–28 from the Transition into Adulthood Supplement of the Panel Study of Income Dynamics. We measured flourishing across emotional, psychological, and social wellbeing, and frequency of engagement in artistic, musical, or theatrical organized activities, biennially 2005–2019. We analyzed data using fixed effects regression and Arellano-Bond methods to control for bidirectional relationships. Increases in arts engagement were associated with increases in flourishing, before and after adjusting for time-varying confounders. This relationship was driven by enhanced psychological and social wellbeing. After controlling for bidirectionality, increases in arts engagement predicted subsequent improvements in flourishing and social wellbeing. In sensitivity analyses, residential area was a moderator; arts engagement was only associated with increased flourishing in metropolitan (and not non-metropolitan) areas. Increases in arts engagement are associated with enhanced flourishing within individuals, and these associations hold across many subgroups of the population. Those in non-metropolitan areas may have fewer opportunities for arts engagement. Future work must consider how funding can be distributed to ensure that the arts are accessible across communities and geographical areas, providing all young people with opportunities to experience their potential benefits

Longitudinal associations between physical activity and other health behaviours during the COVID-19 pandemic: A fixed effects analysis

Background: Government enforced restrictions on movement during the COVID-19 pandemic are likely to have had profound impacts on the daily behaviours of many individuals, including physical activity (PA). Given the pre-pandemic evidence for associations between PA and other health behaviours, changes in PA during the pandemic may have been detrimental for other health behaviours. This study aimed to evaluate whether changes in PA during and after the first national lockdown in the United Kingdom (UK) were associated with concurrent changes in other health behaviours, namely alcohol consumption, sleep, nutrition quality, diet quantity and sedentary time. / Methods: Data were derived from the UCL COVID-19 Social Study. The analytical sample consisted of 52,784 adults followed weekly across 22 weeks of the pandemic from 23rd March to 23rd August 2020. Data were analysed using fixed effects regression. / Results: There was significant within-individual variation in both PA and other health behaviours throughout the study period. Increased PA was positively associated with improved sleep and nutrition quality. However, increases in PA also showed modest associations with increased alcohol consumption and sedentary time. / Conclusion: Our findings indicate that, whilst the first wave of COVID-19 restrictions were in place, increases in PA were associated with improved sleep and better diet. Encouraging people to engage in PA may therefore lead to positive change in other health behaviours in times of adversity. However, increases in PA were also associated with more engagement in the negative health behaviours of alcohol consumption and sedentary time. These associations could be a result of increases in available leisure time for many people during COVID-19 restrictions and require further investigation to inform future public health guidance

Cross-sectional and longitudinal associations between arts engagement, loneliness, and social support in adolescence

PURPOSE: Although arts engagement holds promise for reducing loneliness and enhancing social support, previous research has focussed on older adults. We investigated whether arts engagement was associated with loneliness and social support during adolescence. METHODS: We included 11,780 adolescents aged 11–21 years from the National Longitudinal Study of Adolescent to Adult Health, a nationally representative cohort study. We measured whether adolescents engaged in school-based arts activities (band, book club, chorus, choir, cheerleading, dance, drama club, newspaper, orchestra) at wave one (1994–1995). Loneliness and perceived social support from peers were measured at waves one and two (1996). We used logistic regression to test whether arts engagement was associated with concurrent and subsequent loneliness and social support. RESULTS: Arts engagement was not associated with concurrent or subsequent loneliness. Compared to not engaging, doing one or more school-based arts activities was associated with 59% higher odds of high social support concurrently (odds ratio [OR] = 1.59, 95% CI = 1.32–1.91). However, this cross-sectional association was attenuated after adjusting for demographic, socioeconomic, and health-related covariates (adjusted OR [AOR] = 1.16, 95% CI = 0.95–1.42). In contrast, doing arts activities was associated with 28% higher odds of reporting high social support one year later (AOR = 1.28, 95% CI = 1.03–1.59), independent of covariates and previous social support. CONCLUSIONS: Extracurricular arts activities are associated with increased odds of reporting good subsequent social support from peers. This may be because they provide opportunities for social engagement, developing friendships, and building a sense of community. Exploring these associations in more detail should be a priority, enabling better understanding of this strategy for enhancing social ties during adolescence

Amplified Concern for Social Risk in Adolescence: Development and Validation of a New Measure.

In adolescence, there is a heightened propensity to take health risks such as smoking, drinking or driving too fast. Another facet of risk taking, social risk, has largely been neglected. A social risk can be defined as any decision or action that could lead to an individual being excluded by their peers, such as appearing different to one's friends. In the current study, we developed and validated a measure of concern for health and social risk for use in individuals of 11 years and over (N = 1399). Concerns for both health and social risk declined with age, challenging the commonly held stereotype that adolescents are less worried about engaging in risk behaviours, compared with adults. The rate of decline was steeper for social versus health risk behaviours, suggesting that adolescence is a period of heightened concern for social risk. We validated our measure against measures of rejection sensitivity, depression and risk-taking behaviour. Greater concern for social risk was associated with increased sensitivity to rejection and greater depressed mood, and this association was stronger for adolescents compared with adults. We conclude that social risks should be incorporated into future models of risk-taking behaviour, especially when they are pitted against health risks