Multielectron Ground State Electroluminescence

The ground state of a cavity-electron system in the ultrastrong coupling regime is characterized by the presence of virtual photons. If an electric current flows through this system, the modulation of the light-matter coupling induced by this non-equilibrium effect can induce an extra-cavity photon emission signal, even when electrons entering the cavity do not have enough energy to populate the excited states. We show that this ground-state electroluminescence, previously identified in a single-qubit system [Phys. Rev. Lett. 116, 113601 (2016)] can arise in a many-electron system. The collective enhancement of the light-matter coupling makes this effect, described beyond the rotating wave approximation, robust in the thermodynamic limit, allowing its observation in a broad range of physical systems, from a semiconductor heterostructure with flat-band dispersion to various implementations of the Dicke model.Comment: 32 pages (9+23), 9 figures (3+6

Characterizing The Patient Population With 30-Day Readmissions From COPD and Heart Failure

Under the Hospital Readmission Reduction Program (HRRP), hospitals with high readmission rates are penalized by reductions in Medicare reimbursements. In particular, Parkview Noble hospital has experienced high readmission rates for chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), and acute myocardial infarction (AMI). Parkview Noble’s combined 30-day readmission rates for these conditions is 18.19% compared to the national average of 15.86%. Objective: In order to effectively reduce the readmission rate for COPD and CHF patients at Parkview Noble, this study examined the socioeconomic and clinical factors that can be used to target this patient population for healthcare driven interventions. Design/Methods: Data was collected in the form of a retrospective chart review and phone interview of 260 patients. The data obtained was then analyzed using student t-test, chi-square test, and multi-variable regression to determine statistically promising variables. A linear regression using statistically promising variables was performed to obtained preliminary predictive algorithms for COPD and CHF readmission. The sensitivity and specificity of these equations was then plotted using various cut-off values to determine their practical effectiveness. Results: The statistical analysis determined four factors with strong predictive value including: past ED visits in the last 6 months (p=1.4E-6), past ED admissions in the last year (p=0.03), heart failure with coronary artery disease (p=0.05), and stage of COPD (p=0.06). The sensitivity and specificity plots suggest that it is possible to target 20% of readmission patients while still maintaining over 85% specificity. Conclusions: From this preliminary data it is seen that several variables have value in determining a patient’s likelihood of readmission. Using this data as a benchmark, this study will be expanded to include up to 1,028 more patients before a final predictive algorithm is computed and tested

The History and Risks of Reinforcement Learning and Human Feedback

Reinforcement learning from human feedback (RLHF) has emerged as a powerful technique to make large language models (LLMs) easier to use and more effective. A core piece of the RLHF process is the training and utilization of a model of human preferences that acts as a reward function for optimization. This approach, which operates at the intersection of many stakeholders and academic disciplines, remains poorly understood. RLHF reward models are often cited as being central to achieving performance, yet very few descriptors of capabilities, evaluations, training methods, or open-source models exist. Given this lack of information, further study and transparency is needed for learned RLHF reward models. In this paper, we illustrate the complex history of optimizing preferences, and articulate lines of inquiry to understand the sociotechnical context of reward models. In particular, we highlight the ontological differences between costs, rewards, and preferences at stake in RLHF's foundations, related methodological tensions, and possible research directions to improve general understanding of how reward models function.Comment: 14 pages, 3 figure

Pleasure, Leisure, or Vice? Public Morality in Imperial Cairo, 1882-1949

I investigate the social history of Egypt under British imperial occupation through the lens of morality in order to understand the contestation of cultural change and authority under empire. Points of cultural cleavage between European and local inhabitants in British-occupied Cairo included two customs, gambling and the consumption of intoxicants, which elicited sustained and dynamic reactions from observers of Egyptian society on the local and international level. I show that the presence of alcohol and gambling in public spaces in Cairo contributed directly to the politicization and selective criminalization of public morality. However, the meanings attributed to social practices relating to leisure were continually under negotiation and challenge as state authorities, British liberals, Egyptian reformers and religious leaders, foreign missionaries, and representatives of international temperance movements vied to impose their visions of morality upon Egyptian society

The Evolution of Man Towards Self Actualization

Thesis written by a student in the UNT Honors College discussing his evolution towards self-actualization via existentialism

Raman Spectroscopic and Quantum Chemical Investigation of the Pyridine-Borane Complex and the Effects of Dative Bonding on the Normal Modes of Pyridine

The pyridine-borane (PyBH3) complex was analyzed by Raman vibrational spectroscopy and density functional theory to elucidate its structural and vibrational properties and to compare these with those for neat pyridine (Py). The borane-nitrogen (BN) bond length, the BN dative bond stretching frequency, and the effects of dative-bonded complex formation on Py are presented. Rather than having a single isolated stretching motion, the complex exhibits multiple BN dative bond stretches that are coupled to Py\u27s vibrations. These modes exhibit large shifts that are higher in energy relative to neat Py, similar to previous observations of Py/water mixtures. However, significantly higher charge transfer was observed in the dative-bonded complex when compared to the hydrogen-bonded complex with water. A linear relationship between charge transfer and shifts to higher frequencies of pyridine\u27s vibrational modes agrees well with earlier observations. The present work is of interest to those seeking a stronger relationship between charge-transfer events and concomitant changes in molecular properties