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This thesis uses the exclamation point to represent a way of thinking and working methodology. The exclamation point in mathematics represents a factorial function, an operation for determining all possible orders of a set. Colloquially, the meaning of the exclamation point relies entirely on context. Within a yellow triangle, it means caution or danger, but at the end of a sentence delivering good news, it means excitement. In the context of this thesis, the exclamation point represents enthusiastically and exhaustively reordering objects, words, and processes to highlight shifting meaning

Cultivating Desired Behaviour: Policy Teaching Via Environment-Dynamics Tweaks

In this paper we study, for the first time explicitly, the implications of endowing an interested party (i.e. a teacher) with the ability to modify the underlying dynamics of the environment, in order to encourage an agent to learn to follow a specific policy. We introduce a cost function which can be used by the teacher to balance the modifications it makes to the underlying environment dynamics, with the learner's performance compared to some ideal, desired, policy. We formulate teacher's problem of determining optimal environment changes as a planning and control problem, and empirically validate the effectiveness of our model

Sustainability through Urban Gardening

Three visions of attaining sustainability through urban gardening – at the individual, community, and city level – are explored visually by MacEwan University Design Studies students–Molly Kassian, Nick Larson, and Sherece Burma–in their final project for Visual Communications Photography (VCPH) 340, Documentary Photography. This article emphasizes the process through which these students decided upon their project, located and interviewed their subjects, and created their visual composition. It also outlines the students’ increased awareness of, interest in, and ease with which urbanites and suburbanites can find or grow their own food

Constraining the Environment of CH+ Formation with CH3+ Observations

The formation of CH+ in the interstellar medium has long been an outstanding problem in chemical models. In order to probe the physical conditions of the ISM in which CH+ forms, we propose the use of CH3+ observations. The pathway to forming CH3+ begins with CH+, and a steady state analysis of CH3+ and the reaction intermediary CH2+ results in a relationship between the CH+ and CH3+ abundances. This relationship depends on the molecular hydrogen fraction, f_H2, and gas temperature, T, so observations of CH+ and CH3+ can be used to infer the properties of the gas in which both species reside. We present observations of both molecules along the diffuse cloud sight line toward Cyg OB2 No. 12. Using our computed column densities and upper limits, we put constraints on the f_H2 vs. T parameter space in which CH+ and CH3+ form. We find that average, static, diffuse molecular cloud conditions (i.e. f_H2>0.2, T~60 K) are excluded by our analysis. However, current theory suggests that non-equilibrium effects drive the reaction C+ + H_2 --> CH+ + H, endothermic by 4640 K. If we consider a higher effective temperature due to collisions between neutrals and accelerated ions, the CH3+ partition function predicts that the overall population will be spread out into several excited rotational levels. As a result, observations of more CH3+ transitions with higher signal-to-noise ratios are necessary to place any constraints on models where magnetic acceleration of ions drives the formation of CH+.Comment: 7 pages, 3 figures, 2 tables, accepted for publication in Ap

The Genetic Structure of American Black Bear Populations in the Southern Rocky Mountains

Large and wide-ranging carnivores typically display genetic connectivity across their distributional range. American black bears (Ursus americanus) are vagile carnivores and habitat generalists. However, they are strongly associated with forested habitats; consequently, habitat patchiness and fragmentation have the potential to drive connectivity and the resultant structure between black bear subpopulations. Our analysis of genetic structure of black bears in the southern Rocky Mountains of Wyoming and Colorado (n = 296) revealed two discrete populations: bears in northern Wyoming were distinct (FST = 0.217) from bears in southern Wyoming and Colorado, despite higher densities of anthropogenic development within Colorado. The differentiation we observed indicates that bears in Wyoming originated from two different clades with structure driven by the pattern of contiguous forest, rather than the simple distance between populations. We posit that forested habitat and competitive interactions with brown bears reinforced patterns of genetic structure resulting from historic colonization. Our work suggests that forested habitat is an important force structuring populations in the southern Rocky Mountains, even for populations of highly vagile carnivores

Renewable Energy with Photovoltaic Systems

In view of the perceived depletion of energy sources from fossil fuels, this project undertook a comprehensive evaluation of various alternative energy technologies. Special emphasis was placed on the potential of solar energy and its future development. In particular, we determined when and under what circumstances it will be economically feasible to install solar arrays on a house in Worcester, MA as the primary source of electrical energy

The State of Vaccine Confidence 2016: Global Insights Through a 67-Country Survey.

BACKGROUND: Public trust in immunization is an increasingly important global health issue. Losses in confidence in vaccines and immunization programmes can lead to vaccine reluctance and refusal, risking disease outbreaks and challenging immunization goals in high- and low-income settings. National and international immunization stakeholders have called for better monitoring of vaccine confidence to identify emerging concerns before they evolve into vaccine confidence crises. METHODS: We perform a large-scale, data-driven study on worldwide attitudes to immunizations. This survey - which we believe represents the largest survey on confidence in immunization to date - examines perceptions of vaccine importance, safety, effectiveness, and religious compatibility among 65,819 individuals across 67 countries. Hierarchical models are employed to probe relationships between individual- and country-level socio-economic factors and vaccine attitudes obtained through the four-question, Likert-scale survey. FINDINGS: Overall sentiment towards vaccinations is positive across all 67 countries, however there is wide variability between countries and across world regions. Vaccine-safety related sentiment is particularly negative in the European region, which has seven of the ten least confident countries, with 41% of respondents in France and 36% of respondents in Bosnia & Herzegovina reporting that they disagree that vaccines are safe (compared to a global average of 13%). The oldest age group (65+) and Roman Catholics (amongst all faiths surveyed) are associated with positive views on vaccine sentiment, while the Western Pacific region reported the highest level of religious incompatibility with vaccines. Countries with high levels of schooling and good access to health services are associated with lower rates of positive sentiment, pointing to an emerging inverse relationship between vaccine sentiments and socio-economic status. CONCLUSIONS: Regular monitoring of vaccine attitudes - coupled with monitoring of local immunization rates - at the national and sub-national levels can identify populations with declining confidence and acceptance. These populations should be prioritized to further investigate the drivers of negative sentiment and to inform appropriate interventions to prevent adverse public health outcomes

The Central Region of Barred Galaxies: Molecular Environment, Starbursts, and Secular Evolution

Despite compelling evidence that stellar bars drive gas into the inner 1--2 kpc or circumnuclear (CN) region of galaxies, there are few large, high resolution studies of the CN molecular gas and star formation (SF). We study a sample of local barred non-starbursts and starbursts with high-resolution CO, optical, Ha, RC, Br-gamma, and HST data, and find the following. (1) The inner kpc of bars differs markedly the outer disk and hosts molecular gas surface densities Sigma-gas-m of 500-3500 Msun pc-2, gas mass fractions of 10--30 %, and epicyclic frequencies of several 100--1000 km s-1 kpc-1.Consequently, gravitational instabilities can only set in at high gas densities and grow on a short timescale (few Myr). This high density, short timescale, `burst' mode may explain why powerful starbursts tend to be in the CN region of galaxies. (2) We suggest that the variety in CO morphologies is due to different stages of bar-driven inflow. At late stages, most of the CN gas is inside the outer inner Lindblad resonance (OILR), and has predominantly circular motions. Across the sample, we find bar pattern speeds with upper limits of 43 to 115 km s-1 kpc-1 and OILR radii of > 500 pc. (3) Barred starbursts and non-starbursts have CN SFRs of 3--11 and 0.1--2 Msun yr-1, despite similar CN gas mass. Sigma-gas-m in the starbursts is larger (1000--3500 Msun pc-2) and close to the Toomre critical density over a large region. (4) Molecular gas makes up 10%--30% of the CN dynamical mass (6--30 x 10^9 Msun).In the starbursts, it fuels CN SFRs of 3--11 Msun yr-1, building young, massive, high V/sigma components. We present evidence for such a pseudo-bulge in NGC 3351. Implications for secular evolution along the Hubble sequence are discussed.Comment: Accepted by the Astrophysical Journal. Paper length reduced to fit within APJ page limits. Version of paper with high resolution figures is at http://www.as.utexas.edu/~sj/papers/ms-hires-sj05a.ps.g

Dynamically Driven Evolution of the Interstellar Medium in M51

We report the highest-fidelity observations of the spiral galaxy M51 in CO emission, revealing the evolution of giant molecular clouds (GMCs) vis-a-vis the large-scale galactic structure and dynamics. The most massive GMCs (so-called GMAs) are first assembled and then broken up as the gas flow through the spiral arms. The GMAs and their H2 molecules are not fully dissociated into atomic gas as predicted in stellar feedback scenarios, but are fragmented into smaller GMCs upon leaving the spiral arms. The remnants of GMAs are detected as the chains of GMCs that emerge from the spiral arms into interarm regions. The kinematic shear within the spiral arms is sufficient to unbind the GMAs against self-gravity. We conclude that the evolution of GMCs is driven by large-scale galactic dynamics --their coagulation into GMAs is due to spiral arm streaming motions upon entering the arms, followed by fragmentation due to shear as they leave the arms on the downstream side. In M51, the majority of the gas remains molecular from arm entry through the inter-arm region and into the next spiral arm passage.Comment: 6 pages, including 3 figures. Accepted, ApJ