Exploring NOy chemistry in levitated aqueous aerosol droplets

Chemistry of reactive nitrogen oxides, NOy, is crucial for our understanding of composition and properties of the Earth’s atmosphere. The proof-of-principle experiments demonstrated that we are able to study the atmospheric fate of nitrogen oxides that has significant impact on global climate and hydrological cycle, thus affecting the likelihood of local floods and acid rain

Non-universal Z' from SO(10) GUTs with vector-like family and the origin of neutrino masses

A $Z'$ gauge boson with mass around the (few) TeV scale is a popular example of physics beyond the Standard Model (SM) and can be a fascinating remnant of a Grand Unified Theory (GUT). Recently, $Z'$ models with non-universal couplings to the SM fermions due to extra vector-like states have received attention as potential explanations of the present $R_K$, $R_{K^{\ast}}$ anomalies; this includes GUT model proposals based on the $\mathrm{SO}(10)$ group. In this paper we further develop GUT models with a flavour non-universal low scale $Z'$ and clarify several outstanding issues within them. First, we successfully incorporate a realistic neutrino sector (with linear and/or inverse low scale seesaw mechanism), which was so far a missing ingredient. Second, we investigate in detail their compatibility with the $R_K$, $R_{K^{\ast}}$ anomalies; we find that the anomalies do not have a consistent explanation within such models. Third, we demonstrate that these models have other compelling phenomenological features; we study the correlations between the flavour violating processes of $\mu\to 3e$ and $\mu$-$e$ conversion in a muonic atom, showing how a GUT imprint could manifest itself in experiments.Comment: Revised version, published in NPB. New material, general conclusions unchanged. 30 pages, 4 figures, 2 table

Soft drinks consumption and child behaviour problems: the role of food insecurity and sleep patterns

Objective: To examine whether the association between soft drinks consumption and child behaviour problems differs by food security status and sleep patterns in young children. Design: Cross-sectional observational data from the Fragile Families and Child Wellbeing Study (FFCWS), which collected information on food insecurity, soft drinks consumption, sleep patterns and child behaviour problems. Bivariate and multivariate ordinary least-squares regression analyses predicting child behaviour problems and accounting for socio-economic factors and household characteristics were performed. Setting: Twenty urban cities in the USA with a population of 200 000 or more. Subjects: Parental interviews of 2829 children who were about 5 years old. Results: Soft drinks consumption was associated with aggressive behaviours, withdrawn and attention problems for children aged 5 years. However, the association differed by food security status. The association was mostly statistically insignificant among food-secure children after accounting for socio-economic and demographic characteristics. On the other hand, soft drinks consumption was associated with behaviour problems for food-insecure children even after accounting for these factors. However, after accounting for child sleep patterns, the association between soft drinks consumption and child behaviour problems became statistically insignificant for food-insecure children. Conclusions: The negative association between soft drinks consumption and child behaviour problems could be explained by sleep problems for food-insecure children. Since about 21% of households with children are food insecure, targeted efforts to reduce food insecurity would help improve dietary (reduce soft drinks consumption) and health behaviours (improve sleep) and reduce child behaviour problems

Explaining the Relationship between Paternal Incarceration and Family Well-Being: A Mediating Model Using Food Insecurity

This dissertation explores whether families of incarcerated fathers are more likely to experience food insecurity as a result of the conviction of the father. More specifically, I test whether food insecurity explains some of the devastating consequences of paternal incarceration on mothers and children. Because children of incarcerated fathers are at higher risk of following their fathers’ footsteps, this cycle of incarceration can be self-perpetuating. I try to determine how policy can be used to break this cycle. This dissertation examines the role of food insecurity in explaining the negative impact of paternal incarceration on the well-being of mothers and children. The United States has experienced a huge prison boom over the last 40 years. A growing proportion of the incarcerated population are parents. Children growing up with one or both parents missing tend to have long-lasting disadvantages. Previous studies have attempted to suggest a few mechanisms through which paternal incarceration has negative consequences for families but has not considered the role of food insecurity. I propose a theoretical framework to show that paternal incarceration negatively affects mothers and children through food insecurity. Using a longitudinal study of fragile families, I find that food insecurity explains some of the negative consequences of paternal incarceration on maternal depression. On the other hand, food insecurity plays no role in the effect of paternal incarceration on child behavior problems. The findings also cast doubt on whether paternal incarceration affects child well-being. The implications for policy are two-fold. First, reducing food insecurity would mitigate the negative effects of paternal incarceration on maternal depression. More research is needed in order to understand whether the negative effects of paternal incarceration on maternal well-being can be further mitigated. Second, prison reform would do little to reduce the behavior problems experienced by children of incarcerated fathers. Rather than incarceration, other factors contributing to social disadvantages could explain why children of incarcerated fathers have more behavior problems than other children

Disparities in access to preventive health care services among insured children in a cross sectional study

Children with insurance have better access to care and health outcomes if their parents also have insurance. However, little is known about whether the type of parental insurance matters. This study attempts to determine whether the type of parental insurance affects the access to health care services of children. I used data from the 2009–2013 Medical Expenditure Panel Survey and estimated multivariate logistic regressions (N=26,152). I estimated how family insurance coverage affects the probability that children have a usual source of care, well-child visits in the past year, unmet medical and prescription needs, less than 1 dental visit per year, and unmet dental needs. Children in families with mixed insurance (child publicly insured and parent privately insured) were less likely to have a well-child visit than children in privately insured families (odds ratio=0.86, 95% confidence interval 0.76–0.98). When restricting the sample to publicly insured children, children with privately insured parents were less likely to have a well-child visit (odds ratio=0.82, 95% confidence interval 0.73–0.92), less likely to have a usual source of care (odds ratio=0.79, 95% confidence interval 0.67–0.94), and more likely to have unmet dental needs (odds ratio=1.68, 95% confidence interval 1.10–2.58). Children in families with mixed insurance tend to fare poorly compared to children in publicly insured families. This may indicate that children in these families may be underinsured. Expanding parental eligibility for public insurance or subsidizing private insurance for children would potentially improve their access to preventive care

Disparities in access to preventive health care services among insured children in a cross sectional study

Children with insurance have better access to care and health outcomes if their parents also have insurance. However, little is known about whether the type of parental insurance matters. This study attempts to determine whether the type of parental insurance affects the access to health care services of children. I used data from the 2009–2013 Medical Expenditure Panel Survey and estimated multivariate logistic regressions (N=26,152). I estimated how family insurance coverage affects the probability that children have a usual source of care, well-child visits in the past year, unmet medical and prescription needs, less than 1 dental visit per year, and unmet dental needs. Children in families with mixed insurance (child publicly insured and parent privately insured) were less likely to have a well-child visit than children in privately insured families (odds ratio=0.86, 95% confidence interval 0.76–0.98). When restricting the sample to publicly insured children, children with privately insured parents were less likely to have a well-child visit (odds ratio=0.82, 95% confidence interval 0.73–0.92), less likely to have a usual source of care (odds ratio=0.79, 95% confidence interval 0.67–0.94), and more likely to have unmet dental needs (odds ratio=1.68, 95% confidence interval 1.10–2.58). Children in families with mixed insurance tend to fare poorly compared to children in publicly insured families. This may indicate that children in these families may be underinsured. Expanding parental eligibility for public insurance or subsidizing private insurance for children would potentially improve their access to preventive care

Food insecurity and housing instability in vulnerable families

Reducing the prevalence of household food insecurity has been a long-standing objective of the federal government. Previous research has found many negative consequences of food insecurity for families and households but has not examined its relationship with housing instability. Using longitudinal data from the Fragile Families and Child Wellbeing Study, difference-in-difference models show that food insecurity is associated with housing instability. The association remains statistically significant after accounting for potential selection and unobserved heterogeneity using propensity score matching and excluding households that experienced prior housing instability from the sample. Examining potential mediating factors, I find that material hardship explains about half of this association. These findings suggest that maintaining a strong social safety net would reduce the risk that families experience material hardship and housing instability, which may also reduce the risk of homelessness