The Means to Ending ENDS: Electronic Nicotine Delivery Systems and America’s Youth

Electronic Nicotine Delivery Systems (ENDS) have risen in prominence amongst smokers and non-smokers as a way to inhale nicotine since their introduction to the United States in 2006. Often sold in a variety of mouth-watering flavors, ENDS are extremely enticing to both adolescents and adults. Though they are marketed as a safer alternative to combustible cigarettes, these devices have created a growing public health epidemic of nicotine addiction among adolescent users. Ultimately acknowledging the issue in 2020, the Food & Drug Administration (FDA) released guidelines to the nicotine industry and banned the sale of certain flavored ENDS. However, this flavor ban is not as extensive as other state and local laws, as it leaves open loopholes for the industry. Therefore, this paper proposes that the FDA, in its official rulemaking capacity, creates a regulation that prohibits the sale of all flavored ENDS (including menthol flavors) in all forms (including disposable and tank-systems)

A Fractured Legacy: The Governance, Goals, and Guides of the Hartford Park System

Since its inception in 1853, the Hartford Park System has been a crucial asset to the City of Hartford. The purpose of this thesis is to answer a set of questions about the history and future of Hartford’s parks. How has history shaped the current system of 37 parks that can be found in Hartford today? How important is the park system to the City of Hartford? Who are the most important stakeholders within the park system and what goals do they have? How can the goals created by relevant park stakeholders be consolidated into realistic goals for the City of Hartford? In order to answer these questions, I move from a macro level of analysis of the City of Hartford to a micro level of analysis of relevant stakeholders within the Hartford Park System. I provide a unique overview of the history of the Hartford Park System, an analysis of relevant literature on urban parks, a quantitative analysis of fiscal reports, in depth interviews of relevant stakeholders, and finally a qualitative analysis of master plans. Though the system of governance is complex and often mired in opposing goals, I ultimately offer a list of six goals that the City of Hartford has already made and should continue to strive towards in order to improve the maintenance and recreational capabilities of the Hartford Park System

Forecasting constraints from the cosmic microwave background on eternal inflation

We forecast the ability of cosmic microwave background (CMB) temperature and polarization datasets to constrain theories of eternal inflation using cosmic bubble collisions. Using the Fisher matrix formalism, we determine both the overall detectability of bubble collisions and the constraints achievable on the fundamental parameters describing the underlying theory. The CMB signatures considered are based on state-of-the-art numerical relativistic simulations of the bubble collision spacetime, evolved using the full temperature and polarization transfer functions. Comparing a theoretical cosmic-variance-limited experiment to the WMAP and Planck satellites, we find that there is no improvement to be gained from future temperature data, that adding polarization improves detectability by approximately 30%, and that cosmic-variance-limited polarization data offer only marginal improvements over Planck. The fundamental parameter constraints achievable depend on the precise values of the tensor-to-scalar ratio and energy density in (negative) spatial curvature. For a tensor-to-scalar ratio of $0.1$ and spatial curvature at the level of $10^{-4}$, using cosmic-variance-limited data it is possible to measure the width of the potential barrier separating the inflating false vacuum from the true vacuum down to $M_{\rm Pl}/500$, and the initial proper distance between colliding bubbles to a factor $\pi/2$ of the false vacuum horizon size (at three sigma). We conclude that very near-future data will have the final word on bubble collisions in the CMB.Comment: 14 pages, 6 figure

First Observational Tests of Eternal Inflation

The eternal inflation scenario predicts that our observable Universe resides inside a single bubble embedded in a vast inflating multiverse. We present the first observational tests of eternal inflation, performing a search for cosmological signatures of collisions with other bubble universes in cosmic microwave background data from the WMAP satellite. We conclude that the WMAP 7-year data do not warrant augmenting the cold dark matter model with a cosmological constant with bubble collisions, constraining the average number of detectable bubble collisions on the full sky N̅ _s<1.6 at 68% C.L. Data from the Planck satellite can be used to more definitively test the bubble-collision hypothesis

MHF1–2/CENP-S-X performs distinct roles in centromere metabolism and genetic recombination

Peer reviewedPublisher PD

SINCERE: Supervised Information Noise-Contrastive Estimation REvisited

The information noise-contrastive estimation (InfoNCE) loss function provides the basis of many self-supervised deep learning methods due to its strong empirical results and theoretic motivation. Previous work suggests a supervised contrastive (SupCon) loss to extend InfoNCE to learn from available class labels. This SupCon loss has been widely-used due to reports of good empirical performance. However, in this work we suggest that the specific SupCon loss formulated by prior work has questionable theoretic justification, because it can encourage images from the same class to repel one another in the learned embedding space. This problematic behavior gets worse as the number of inputs sharing one class label increases. We propose the Supervised InfoNCE REvisited (SINCERE) loss as a remedy. SINCERE is a theoretically justified solution for a supervised extension of InfoNCE that never causes images from the same class to repel one another. We further show that minimizing our new loss is equivalent to maximizing a bound on the KL divergence between class conditional embedding distributions. We compare SINCERE and SupCon losses in terms of learning trajectories during pretraining and in ultimate linear classifier performance after finetuning. Our proposed SINCERE loss better separates embeddings from different classes during pretraining while delivering competitive accuracy

A robust constraint on cosmic textures from the cosmic microwave background

Fluctuations in the cosmic microwave background (CMB) contain information which has been pivotal in establishing the current cosmological model. These data can also be used to test well-motivated additions to this model, such as cosmic textures. Textures are a type of topological defect that can be produced during a cosmological phase transition in the early universe, and which leave characteristic hot and cold spots in the CMB. We apply Bayesian methods to carry out a rigorous test of the texture hypothesis, using full-sky data from the Wilkinson Microwave Anisotropy Probe. We conclude that current data do not warrant augmenting the standard cosmological model with textures. We rule out at 95% confidence models that predict more than 6 detectable cosmic textures on the full sky.Comment: 5 pages, 2 figures. v2: replaced with version accepted by PRL (minor amendments to reduce length and address referee comments