Maintaining the Profitability of Gaming’s Premium Players

Purpose: This paper does not seek to condemn the use of incentives for high-end casino players. Rather, it is intended to illuminate common policies and practices that might require more measurement and consideration prior to being distributed. This paper also explores and examines existing literature and findings regarding the profitability of high-end casino players and offers guidelines for evaluating profitability. Statement of Objective: This paper targets existing policies and practices in the contemporary Las Vegas casino gaming business, separately examining the profitability of each incentive program or common practice. As a consolidated examination of such practices, this paper can serve as a reference for any casino executive interested in examining the profitability of his/her property’s incentives. Justification: In most destination markets, multiple casino properties compete for the same high-end casino players. At a time when profits are scarce, it is especially important to examine the viability and profitability of the incentives and promotions used to attract and retain premium action. The implications of this study are important to the gaming community because they expose and differentiate practices that have potentially negative consequences

Sauna Exposure Immediately Prior to Short-term Heat Acclimation Accelerates Phenotypic Adaptation in Females

Objectives: Investigate whether a sauna exposure prior to short-term heat acclimation (HA) accelerates phenotypic adaptation in females. Design: Randomised, repeated measures, cross-over trial. Methods: Nine females performed two 5-d HA interventions (controlled hyperthermia Tre ≥ 38.5°C), separated by 7-wk, during the follicular phase of the menstrual cycle confirmed by plasma concentrations of 17-β estradiol and progesterone. Prior to each 90-min HA session participants sat for 20-min in either a temperate environment (20°C, 40% RH; HAtemp) wearing shorts and sports bra or a hot environment (50°C, 30% RH) wearing a sauna suit to replicate sauna conditions (HAsauna). Participants performed a running heat tolerance test (RHTT) 24-hr pre and 24-hr post HA. Results: Mean heart rate (HR) (85±4 vs. 68±5 bpm, p≤0.001), sweat rate (0.4±0.2 vs. 0.0±0.0 L.hr-1, p≤0.001), and thermal sensation (6±0 vs. 5±1, p=0.050) were higher during the sauna compared to temperate exposure. Resting rectal temperature (Tre) (-0.28±0.16°C), peak Tre (-0.42±0.22°C), resting HR (-10±4 bpm), peak HR (-12±7 bpm), Tre at sweating onset (-0.29±0.17°C) (p≤0.001), thermal sensation (-0.5±0.5; p=0.002), and perceived exertion (-3±2; p≤0.001) reduced during the RHTT, following HAsauna; but not HAtemp. Plasma volume expansion was greater following HAsauna (HAsauna, 9±7%; HAtemp, 1±5%; p=0.013). Sweat rate (p≤0.001) increased and sweat NaCl (p=0.006) reduced during the RHTT following HAsauna and HAtemp. Conclusions: This novel strategy initiated HA with an attenuation of thermoregulatory, cardiovascular, and perceptual strain in females due to a measurably greater strain in the sauna compared to temperate exposure when adopted prior to STHA

Kirchhoff's Loop Law and the maximum entropy production principle

In contrast to the standard derivation of Kirchhoff's loop law, which invokes electric potential, we show, for the linear planar electric network in a stationary state at the fixed temperature,that loop law can be derived from the maximum entropy production principle. This means that the currents in network branches are distributed in such a way as to achieve the state of maximum entropy production.Comment: revtex4, 5 pages, 2 figure

Dynamical approach to the microcanonical ensemble

An analytical method to compute thermodynamic properties of a given Hamiltonian system is proposed. This method combines ideas of both dynamical systems and ensemble approaches to thermodynamics, providing de facto a possible alternative to traditional Ensemble methods. Thermodynamic properties are extracted from effective motion equations. These equations are obtained by introducing a general variational principle applied to an action averaged over a statistical ensemble of paths defined on the constant energy surface. The method is applied first to the one dimensional (\beta)-FPU chain and to the two dimensional lattice (\phi ^{4}) model. In both cases the method gives a good insight of some of their statistical and dynamical properties.Comment: 5 pages, 4 figures, RevTe

Perioperative complications among head and neck surgery patients with COVID-19

Background: Patients undergoing surgery for head and neck cancer (HNC) have potentially high perioperative complication rates. Recent studies indicate that preoperative COVID-19 infection poses increased risk for postoperative complications in other fields. However, to date, there has not been data showing the effect of COVID-19 on complication rates for HNC. Here, a large database was employed to assess if perioperative COVID-19 increased the risk of perioperative complications among those undergoing HNC surgery. Methods: A retrospective investigation was conducted using a multi-institutional research database. Subjects who underwent HNC surgery from January 2020 to September 2022 were identified using the International Classification of Diseases and Current Procedure Terminology codes. Thirty-day surgical and medical complications were assessed for those diagnosed with COVID-19 infection from 7 days before or after surgery compared to those who were COVID-19 negative. Cohorts were propensity scores matched by age, sex, and race. Results: Perioperative COVID-19 was present in n = 208 and absent in n = 15 158 subjects that underwent HNC surgery. For unmatched analyses, there was a statistically significant increased risk in the 30-day postoperative period in COVID-19-positive patients for the following surgical complications: surgical site fistula, free tissue transfer (FTT) complication, FTT failure, and death. Additionally, there was a statistically significant increased risk in the 30-day postoperative period in COVID-19-positive patients for the following medical complications: ventilator support, pneumonia, vasopressor, acute renal failure, and myocardial infarction. Conclusion: This large, retrospective populational study suggests HNC patients are at increased risk for death and several perioperative complications. This investigation is the first to address this clinical question

On the equilibria of finely discretized curves and surfaces

Our goal is to identify the type and number of static equilibrium points of solids arising from fine, equidistant $n$-discretrizations of smooth, convex surfaces. We assume uniform gravity and a frictionless, horizontal, planar support. We show that as $n$ approaches infinity these numbers fluctuate around specific values which we call the imaginary equilibrium indices associated with the approximated smooth surface. We derive simple formulae for these numbers in terms of the principal curvatures and the radial distances of the equilibrium points of the solid from its center of gravity. Our results are illustrated on a discretized ellipsoid and match well the observations on natural pebble surfaces.Comment: 21 pages, 2 figure

The Influence of the effect of solute on the thermodynamic driving force on grain refinement of Al alloys

Grain refinement is known to be strongly affected by the solute in cast alloys. Addition of some solute can reduce grain size considerably while others have a limited effect. This is usually attributed to the constitutional supercooling which is quantified by the growth restriction factor, Q. However, one factor that has not been considered is whether different solutes have differing effects on the thermodynamic driving force for solidification. This paper reveals that addition of solute reduces the driving force for solidification for a given undercooling, and that for a particular Q value, it is reduced more substantially when adding eutectic-forming solutes than peritectic-forming elements. Therefore, compared with the eutectic-forming solutes, addition of peritectic-forming solutes into Al alloys not only possesses a higher initial nucleation rate resulted from the larger thermodynamic driving force for solidification, but also promotes nucleation within the constitutionally supercooled zone during growth. As subsequent nucleation can occur at smaller constitutional supercoolings for peritectic-forming elements, a smaller grain size is thus produced. The very small constitutional supercooling required to trigger subsequent nucleation in alloys containing Ti is considered as a major contributor to its extraordinary grain refining efficiency in cast Al alloys even without the deliberate addition of inoculants.The Australian Research Council (ARC DP10955737)

Dimensionless cosmology

Although it is well known that any consideration of the variations of fundamental constants should be restricted to their dimensionless combinations, the literature on variations of the gravitational constant $G$ is entirely dimensionful. To illustrate applications of this to cosmology, we explicitly give a dimensionless version of the parameters of the standard cosmological model, and describe the physics of Big Bang Neucleosynthesis and recombination in a dimensionless manner. The issue that appears to have been missed in many studies is that in cosmology the strength of gravity is bound up in the cosmological equations, and the epoch at which we live is a crucial part of the model. We argue that it is useful to consider the hypothetical situation of communicating with another civilization (with entirely different units), comparing only dimensionless constants, in order to decide if we live in a Universe governed by precisely the same physical laws. In this thought experiment, we would also have to compare epochs, which can be defined by giving the value of any {\it one} of the evolving cosmological parameters. By setting things up carefully in this way one can avoid inconsistent results when considering variable constants, caused by effectively fixing more than one parameter today. We show examples of this effect by considering microwave background anisotropies, being careful to maintain dimensionlessness throughout. We present Fisher matrix calculations to estimate how well the fine structure constants for electromagnetism and gravity can be determined with future microwave background experiments. We highlight how one can be misled by simply adding $G$ to the usual cosmological parameter set

75th Anniversary of ‘Existence of Electromagnetic-Hydrodynamic Waves’

We have recently passed the 75th anniversary of one of the most important results in solar and space physics: Hannes Alfv\'en's discovery of Alfv\'en waves and the Alfv\'en speed. To celebrate the anniversary, this article recounts some major episodes in the history of MHD waves. Following an initially cool reception, Alfv\'en's ideas were propelled into the spotlight by Fermi's work on cosmic rays, the new mystery of coronal heating and, as scientific perception of interplanetary space shifted dramatically and the space race started, detection of Alfv\'en waves in the solar wind. From then on, interest in MHD waves boomed, laying the foundations for modern remote observations of MHD waves in the Sun, coronal seismology and some of today's leading theories of coronal heating and solar wind acceleration. In 1970, Alfv\'en received the Nobel Prize for his work in MHD, including these discoveries. The article concludes with some reflection about what the history implies about the way we do science, especially the advantages and pitfalls of idealised mathematical models.Comment: 10 pages, accepted by Solar Physic