Spatio-temporal models for air pollution

Air pollution is the biggest environmental risk to global health and it is estimated that, globally, 7 million deaths can be attributed to air pollution each year \citep{WHO2018}. The World Bank estimates that, in 2016, the overall cost of ambient air pollution to the global economy was an estimated US \5.7 trillion or 4.4 per cent of global GDP \citep{worldbank}. A number of different air pollutants have been associated with adverse health effects, including fine particulate matter (PM_{2.5}$), nitrogen dioxide and ozone. In studies of the effects of air pollution, exposure information is often obtained from a fixed number of monitoring sites within the region of interest. However, an increasing number of models of air pollution are being used that provide estimates of concentrations. These are used to represent exposures at every location in a health study area, rather than just at a number of fixed measurement locations. Another use of modelling of air pollution is to provide short-term forecasts that can be used to inform the behaviour of vulnerable people. In this thesis, we develop statistical approaches to modelling, and forecasting, daily concentrations of$\mbox{PM}_{2.5}$in urban areas. We consider two different approaches, both in terms of model formulation and performing inference. The first approach is Dynamic Space-Time Models (DSTM). Under this framework, a \textit{data} model relates observations (measurements) to a \textit{process} model that specifies the dynamic evolution of the "true" underlying process. This approach is implemented using two different methods for estimation: methods of moments and expectation-maximisation. We also develop an approach using Bayesian Hierarchical Spatio-Temporal modelling (BHSTM). The inference is done using computational efficient methods for Bayesian inference (integrated nested Laplace approximations). This model allows predictions of daily PM$_{2.5}$over both space and time, which can be used to interpolate both past measurements and future predictions. Both approaches were implemented using data from Greater London, with their performance evaluated in terms of their ability to predict daily concentrations of PM$_{2.5}$over time at different measuring sites. Both methods were able to accurately predict future values of daily PM$_{2.5}$ at different locations, with one-day ahead predictions being more accurate than those used for longer periods, as might be expected. One of the major advantages of the BHSTM approach is that it provides a straightforward method for producing estimates of the uncertainty that is associated with predictions

The properties of attractors of canalyzing random Boolean networks

We study critical random Boolean networks with two inputs per node that contain only canalyzing functions. We present a phenomenological theory that explains how a frozen core of nodes that are frozen on all attractors arises. This theory leads to an intuitive understanding of the system's dynamics as it demonstrates the analogy between standard random Boolean networks and networks with canalyzing functions only. It reproduces correctly the scaling of the number of nonfrozen nodes with system size. We then investigate numerically attractor lengths and numbers, and explain the findings in terms of the properties of relevant components. In particular we show that canalyzing networks can contain very long attractors, albeit they occur less often than in standard networks.Comment: 9 pages, 8 figure

Eccentric binary black-hole mergers: The transition from inspiral to plunge in general relativity

We study the transition from inspiral to plunge in general relativity by computing gravitational waveforms of non-spinning, equal-mass black-hole binaries. We consider three sequences of simulations, starting with a quasi-circular inspiral completing 1.5, 2.3 and 9.6 orbits, respectively, prior to coalescence of the holes. For each sequence, the binding energy of the system is kept constant and the orbital angular momentum is progressively reduced, producing orbits of increasing eccentricity and eventually a head-on collision. We analyze in detail the radiation of energy and angular momentum in gravitational waves, the contribution of different multipolar components and the final spin of the remnant. We find that the motion transitions from inspiral to plunge when the orbital angular momentum L=L_crit is about 0.8M^2. For L<L_crit the radiated energy drops very rapidly. Orbits with L of about L_crit produce our largest dimensionless Kerr parameter for the remnant, j=J/M^2=0.724. Generalizing a model recently proposed by Buonanno, Kidder and Lehner to eccentric binaries, we conjecture that (1) j=0.724 is the maximal Kerr parameter that can be obtained by any merger of non-spinning holes, and (2) no binary merger (even if the binary members are extremal Kerr black holes with spins aligned to the orbital angular momentum, and the inspiral is highly eccentric) can violate the cosmic censorship conjecture.Comment: Added sequence of long inspirals to the study. To match published versio

Economic and social foundations of collective action : an inter-disciplinary institutional approach to Mexican dairy farmers

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on February 13, 2008)Thesis (Ph. D.) University of Missouri-Columbia 2007.This research uses an interdisciplinarian neo-institutional approach to examine formal and informal institutional factors that influence dairy farmers' ideas about participation in collective action in the "Altos Sur" region in Jalisco, Mexico. Data collected from face-to-face interviews of a sample of 100 dairy farmers was used to measure and analyze formal and informal factors that influence these dairy farmers' decisions about collective action; whether or not to join other dairy farmers to produce milk in a collective way. This research tests hypotheses not only on dairy farmers' perceptions of formal institutions such as the state, the market and the economic organization, but also on their perceptions of informal institutions such as bonding and bridging social capital which might have influenced them to participate in collective action. Results of this research indicate that these dairy farmers' motivations to go into entrepreneurial collective action were influenced by both formal and informal institutional perceptions. Perceptions of formal institutions that affected willingness to engage in collective action include views about government responsibilities and duties in the milk industry; perceptions of the functionality of an economic organization, and perceptions of market functionality. The surveys also show that farmers' perceptions of bonding social capital had a more significant influence than bridging social capital on whether or not they were encouraged to participate in collective action. These findings are discussed in relation to the larger issue of whether collective entrepreneurial action can mediate market failure that is exacerbated by globalization.Includes bibliographical reference

Collins functions for pions from SIDIS and new e+e- data: a first glance at their transverse momentum dependence

New data from Belle and BaBar Collaborations on azimuthal asymmetries, measured in e+e- annihilations into pion pairs at Q^2=112 GeV^2, allow to take the first, direct glance at the transverse momentum dependence of the Collins functions, in addition to their z dependence. These data, together with available Semi-Inclusive Deep Inelastic Scattering (SIDIS) data on the Collins asymmetry, are simultaneously analysed in the framework of the generalised parton model assuming two alternative Q^2 evolution schemes and exploiting two different parameterisations for the Collins functions. The corresponding results for the transversity distributions are presented. Analogous data, newly released by the BESIII Collaboration, on e+e- annihilations into pion pairs at the lower Q^2 of 13 GeV^2, offer the possibility to explore the sensitivity of these azimuthal correlations on transverse momentum dependent evolution effects.Comment: 20 pages, 15 figures, 4 table

Latino farmers and USDA agents talk about challenges to access and use of USDA programs

Presentation made at Latinos in the Heartland (11th : 2013 : Columbia, Mo.) and published in the annual conference proceedings.According to the U.S. Census of Agriculture, 25% of Missouri Latino farmers and rancher stopped farming and ranching operations from 2002 to 2007, even though the population of Latinos was increasing across the state. One possibility was that Latino farmers and ranchers were not effectively accessing USDA support programs. In order to better understand this dramatic decline in the number of Latino farmers and ranchers and to identify ways to improve access and use of USDA programs by Latino farmers and ranchers, 30 farmers and ranchers and five USDA agents were interviewed in southwest, Missouri. Factors such as cultural influence, English communication, insufficient network connections, poor business literacy and a lack of technical knowledge on farming and ranching, constrained the farmers and ranchers from maintaining a productive and sustainable relationship with the USDA. These factors were mentioned by all of the individuals interviewed. In addition, they agreed that one of the main challenges is to create a communication bridge that begins to explore and analyze Latino farmers and ranchers qualifications for access and use of USDA programs. This bridge may facilitate a better understanding of the need for Latino farmers and ranchers to access and use USDA programs, as well as improve their understanding of programs and services offered by the USDA. Improving relationships between Latino farmers and ranchers and USDA resource agencies can assist these producers with establishing and growing their enterprises, as well as influence the Latino farmers and ranchers socioeconomic integration into the broader community

Probing Trilinear Gauge Boson Interactions via Single Electroweak Gauge Boson Production at the LHC

We analyze the potential of the CERN Large Hadron Collider (LHC) to study anomalous trilinear vector-boson interactions W^+ W^- \gamma and W^+ W^- Z through the single production of electroweak gauge bosons via the weak boson fusion processes q q -> q q W (-> \ell^\pm \nu) and q q -> q q Z(-> \ell^+ \ell^-) with \ell = e or \mu. After a careful study of the standard model backgrounds, we show that the single production of electroweak bosons at the LHC can provide stringent tests on deviations of these vertices from the standard model prediction. In particular, we show that single gauge boson production exhibits a sensitivity to the couplings \Delta \kappa_{Z,\gamma} similar to that attainable from the analysis of electroweak boson pair production.Comment: 20 pages, 6 figure

Social power of preadolescent children on influence in their mothers’ purchasing behavior: initial study in Peruvian toy stores

Purpose: This paper aims to investigate the relationship between legitimate and expert social power types of preadolescent children on the influence perception in their mothers’ purchasing behavior in Peruvian toy stores. The literature review takes into consideration the concepts of social power and the influence on family behavior to then focus on social power within family behavior with the purpose of mainly developing four hypotheses regarding purchasing behavior. Design/methodology/approach: The methodology followed a non-experimental transversal correlational-causal design. A pilot sample size of 67 cases was used. The sample was based on an objective population of Peruvian mothers of families that live in northern Lima and that go to purchase toys to major shopping centers with their children aged 8-11 years. Findings: The results show that the expert social power, as well as the legitimate social power, has a strong relationship. In addition, both social powers have an impact on the influence perception in purchasing child-mother, but not on the influence perception in purchasing mother-child. Moreover, the test of moderation of the expenditure level on toy purchases did not have an effect on the context that was studied. Originality/value: The contribution shows that important changes are happening in the consumption behavior on the aspect of children influencing mothers, and that for Latin American contexts, the level of expenditure still does not crucially affect the causality demonstrated.Objetivo: Este trabajo tiene como objetivo investigar la relación entre tipos de poder social legítimo y experto de niños preadolescentes sobre la percepción de influencia en el comportamiento de compra de sus madres en las jugueterías peruanas. La revisión de la literatura toma en consideración los conceptos de poder social y la influencia en el comportamiento familiar para luego enfocarse en el poder social dentro del comportamiento familiar con el propósito de desarrollar principalmente cuatro hipótesis sobre el comportamiento adquisitivo. Diseño / metodología / enfoque: La metodología siguió un diseño correlacional-causal transversal no experimental. Se utilizó un tamaño de muestra piloto de 67 casos. La muestra se basó en una población objetiva de madres peruanas de familias que viven en el norte de Lima y que acuden a comprar juguetes a los principales centros comerciales con sus hijos de 8 a 11 años. Recomendaciones: Los resultados muestran que el poder social experto, así como el poder social legítimo, tienen una fuerte relación. Además, ambos poderes sociales inciden en la percepción de influencia en la compra hijo-madre, pero no en la percepción de influencia en la compra madre-hijo. Además, la prueba de moderación del nivel de gasto en compra de juguetes no tuvo efecto en el contexto estudiado. Originalidad / valor: El aporte muestra que se están produciendo cambios importantes en el comportamiento de consumo en el aspecto de los niños que influyen en las madres, y que para los contextos latinoamericanos, el nivel de gasto aún no afecta de manera crucial la causalidad demostrada