Observational Implications of Cosmological Event Horizons

In a universe dominated by a small cosmological constant or by eternal dark energy with equation of state w < -1/3, observers are surrounded by event horizons. The horizons limit how much of the universe the observers can ever access. We argue that this implies a bound N~60 on the number of e-folds of inflation that will ever be observable in our universe if the scale of the dark energy today is ~(10^{-3} eV)^4. This bound is independent of how long inflation lasted, or for how long we continue to observe the sky. The bound arises because the imprints of the inflationary perturbations thermalize during the late acceleration of the universe. They "inflate away" just like the initial inhomogeneities during ordinary inflation. Thus the current CMB data may be looking as far back in the history of the universe as will ever be possible, making our era a most opportune time to study cosmology.Comment: 10 pages, 3 figures; v2: few typos fixed, to appear in PL

LAND VALUE RESPONSE TO HIGHWAY INVESTMENTS: EVIDENCE FROM SUBURBAN COOK COUNTY 1943-1962

In this paper we investigate unimproved land in Cook County, Illinois to see if land values experienced changes due to highway construction in the 1950s. Theory suggests transportation investment should increase land values but assembling supportive data for analysis has been problematic . Previous case studies on the issue have proven contradictory. Our goal here is to illuminate the various influences on land values and to use appropriate methodologies to help clarify and confirm our observations. We utilize a two-way fixed effect event study model and we find evidence that land values increase in response to a highway being built in quarter sections within 0.5 miles of newly opened interstate sections. Our work sheds light on how land values responded to new transportation infrastructure and raises valuable questions for further research

A mathematical framework for operational fine tunings

In the framework of ontological models, the features of quantum mechanics that emerge as inherently nonclassical always involve properties that are fine tuned, i.e. properties that hold at the operational level but break at the ontological level (they only hold for fine tuned values of the ontic parameters). Famous examples of such features are contextuality and nonlocality. We here develop a precise theory-independent mathematical framework for characterizing operational fine tunings. These are distinct from causal fine tunings - already introduced by Wood and Spekkens in [NJP,17 033002(2015)] - as they do not involve any assumption on the underlying causal structure. We show how all the already known examples of operational fine tunings fit into our framework, we discuss possibly new fine tunings and we use the framework to shed new light on the relation between nonlocality and generalized contextuality, where the former can involve a causal fine tuning too, unlike the latter. The framework is also formulated in the language of category theory and functors.Comment: 26 pages, 6 figure

Decomposition numbers for weight 3 blocks of Iwahori--Hecke algebras of type B

Let B be a weight-$3$ block of an Iwahori--Hecke algebra of type B over any field. We develop the combinatorics of B to prove that the decomposition numbers for B are all 0 or 1

Cystic Lesions of the Aerodigestive Tract: Anatomic Relationships and Differential Diagnosis

This educational exhibit will discuss an anatomically based differential diagnosis for cystic lesions of the aerodigestive tract and present and an algorithmic, anatomically-based diagnostic approach for these cysts. Cystic lesions of the aerodigestive tract are common findings at MRI and CT neck imaging. The spectrum of aerodigestive tract cystic lesions is broad and their clinical significance is widely varied. Differentiation of these lesions based on anatomic relationships can be helpful in guiding management. Representative images were acquired from PACS and labeled to highlight anatomic relationships to aid in accurate diagnosis

Spike voltage topography in temporal lobe epilepsy

We investigated the voltage topography of interictal spikes in patients with temporal lobe epilepsy (TLE) to see whether topography was related to etiology for TLE. Adults with TLE, who had epilepsy surgery for drug-resistant seizures from 2011 until 2014 at Jefferson Comprehensive Epilepsy Center were selected. Two groups of patients were studied: patients with mesial temporal sclerosis (MTS) on MRI and those with other MRI findings. The voltage topography maps of the interictal spikes at the peak were created using BESA software. We classified the interictal spikes as polar, basal, lateral, or others. Thirty-four patients were studied, from which the characteristics of 340 spikes were investigated. The most common type of spike orientation was others (186 spikes; 54.7%), followed by lateral (146; 42.9%), polar (5; 1.5%), and basal (3; 0.9%). Characteristics of the voltage topography maps of the spikes between the two groups of patients were somewhat different. Five spikes in patients with MTS had polar orientation, but none of the spikes in patients with other MRI findings had polar orientation (odds ratio = 6.98, 95% confidence interval = 0.38 to 127.38; p = 0.07). Scalp topographic mapping of interictal spikes has the potential to offer different information than visual inspection alone. The present results do not allow an immediate clinical application of our findings; however, detecting a polar spike in a patient with TLE may increase the possibility of mesial temporal sclerosis as the underlying etiology

Session D, 2017 Third Place: The Effects of Sunscreen on Photosynthetic Filamentous Algae

Algae are photosynthetic, often single celled aquatic organisms which serve as one of the most basic prey organisms in a given ecosystem. They are susceptible to changes in the aquatic ecosystem, and when chemicals found in sunscreen are introduced, they may be affected. Based upon a previous study we hypothesize that filamentous algae will have a greater rate of photosynthesis in water where sunscreen is present as compared to water where sunscreen is not present due to the lack of UV light penetration. For this experiment, we collected algae from South Bay, and placed 4 mL samples into 118mL jars, with one control group and three experimental groups of varying sunscreen concentrate. The change in dissolved oxygen was recorded. We ran this test in outside conditions, and once under a UV and sun lamp. We then repeated the set of tests with less sunscreen to account for a potential error in light penetration, as well as a trial without UV to make sure it was in fact UV that impacted photosynthesis. Using ANOVA and Tukey statistical tests our results showed that our hypothesis was not supported, but there were other trends that were noticeable. This shows that sunscreen has a negative effect on algae photosynthesis

Boundaries of Universal Theories

Universal theories are a broad class of well-motivated microscopic dynamics of the electroweak sector that go beyond the Standard Model description. The long distance physics is described by electroweak parameters which correspond to local operators in the Effective Field Theory. We show how unitarity and analyticity constrain the space of parameters. In particular, the $W$ and $Y$ parameters are constrained to be positive and are necessarily the leading terms in the low energy expansion. We assess the impact of unitarity on the interpretation of Drell-Yan data. In passing, we uncover an unexpected Wilson coefficient transcendental cancellation at the $\mathcal{O}(<10^{-3})$ level.Comment: 15 pages, 3 figure

Reducing the Environmental Impact of Wireless Communication via Probabilistic Machine Learning

Machine learning methods are increasingly adopted in communications problems, particularly those arising in next generation wireless settings. Though seen as a key climate mitigation and societal adaptation enabler, communications related energy consumption is high and is expected to grow in future networks in spite of anticipated efficiency gains in 6G due to exponential communications traffic growth. To make meaningful climate mitigation impact in the communications sector, a mindset shift away from maximizing throughput at all cost and towards prioritizing energy efficiency is needed. Moreover, this must be adopted in both existing (without incurring further embodied carbon costs through equipment replacement) and future network infrastructure, given the long development time of mobile generations. To that end, we present summaries of two such problems, from both current and next generation network specifications, where probabilistic inference methods were used to great effect: using Bayesian parameter tuning we are able to safely reduce the energy consumption of existing hardware on a live communications network by $11\%$ whilst maintaining operator specified performance envelopes; through spatiotemporal Gaussian process surrogate modeling we reduce the overhead in a next generation hybrid beamforming system by over $60\%$, greatly improving the networks' ability to target highly mobile users such as autonomous vehicles. The Bayesian paradigm is itself helpful in terms of energy usage, since training a Bayesian optimization model can require much less computation than, say, training a deep neural network