Readmission rates in not-for-profit vs. proprietary hospitals before and after the hospital readmission reduction program implementation.

BACKGROUND: The Patient Protection and Affordable Care Act established the Hospital Readmission Reduction Program (HRRP) to penalize hospitals with excessive 30-day hospital readmissions of Medicare enrollees for specific conditions. This policy was aimed at increasing the quality of care delivered to patients and decreasing the amount of money paid for potentially preventable hospital readmissions. While it has been established that the number of 30-day hospital readmissions decreased after program implementation, it is unknown whether this effect occurred equally between not-for-profit and proprietary hospitals. The aim of this study was to determine whether or not the HRRP decreased readmission rates equally between not-for-profit and proprietary hospitals between 2010 and 2012. METHODS: Data on readmissions came from the Dartmouth Atlas and hospital ownership data came from the Centers for Medicare and Medicaid Services. Data were joined using the Medicare provider number. Using a difference-in-differences approach, bivariate and regression analyses were conducted to compare readmission rates between not-for-profit and proprietary hospitals between 2010 and 2012 and were adjusted for hospital characteristics. RESULTS: In 2010, prior to program implementation, unadjusted readmission rates for proprietary and not-for-profit hospitals were 16.16% and 15.78%, respectively. In 2012, following program implementation, 30-day readmission rates dropped to 15.76% and 15.29% for proprietary and not-for-profit hospitals. The data suggest that the implementation of the Hospital Readmission Reduction Program had similar effects on not-for-profit and proprietary hospitals with respect to readmission rates, even after adjusting for confounders. CONCLUSIONS: Although not-for-profit hospitals had lower 30-day readmission rates than proprietary hospitals in both 2010 and 2012, they both decreased after the implementation of the HRRP and the decreases were not statistically significantly different. Thus, this study suggests that the Hospital Readmission Reduction Program was equally effective in reducing readmission rates, despite ownership status

Thermodynamics of third order Lovelock anti-de Sitter black holes revisited

We compute the mass and the temperature of third order Lovelock black holes with negative Gauss-Bonnet coefficient $\alpha_2<0$ in anti-de Sitter space and perform the stability analysis of topological black holes. When $k=-1$, the third order Lovelock black holes are thermodynamically stable for the whole range $r_+$. When $k=1$, we found that the black hole has an intermediate unstable phase for $D=7$. In eight dimensional spacetimes, however, a new phase of thermodynamically unstable small black holes appears if the coefficient $\tilde{\alpha}$ is under a critical value. For $D\geq 9$, black holes have similar the distributions of thermodynamically stable regions to the case where the coefficient $\tilde{\alpha}$ is under a critical value for $D=8$. It is worth to mention that all the thermodynamic and conserved quantities of the black holes with flat horizon don't depend on the Lovelock coefficients and are the same as those of black holes in general gravity.Comment: 15 pages, 22 figure

Exact Gravitational Quasinormal Frequencies of Topological Black Holes

We compute the exact gravitational quasinormal frequencies for massless topological black holes in d-dimensional anti-de Sitter space. Using the gauge invariant formalism for gravitational perturbations derived by Kodama and Ishibashi, we show that in all cases the scalar, vector, and tensor modes can be reduced to a simple scalar field equation. This equation is exactly solvable in terms of hypergeometric functions, thus allowing an exact analytic determination of the gravitational quasinormal frequencies.Comment: 14 pages, Latex; v2 additional reference

Stability of Topological Black Holes

We explore the classical stability of topological black holes in d-dimensional anti-de Sitter spacetime, where the horizon is an Einstein manifold of negative curvature. According to the gauge invariant formalism of Ishibashi and Kodama, gravitational perturbations are classified as being of scalar, vector, or tensor type, depending on their transformation properties with respect to the horizon manifold. For the massless black hole, we show that the perturbation equations for all modes can be reduced to a simple scalar field equation. This equation is exactly solvable in terms of hypergeometric functions, thus allowing an exact analytic determination of potential gravitational instabilities. We establish a necessary and sufficient condition for stability, in terms of the eigenvalues $\lambda$ of the Lichnerowicz operator on the horizon manifold, namely $\lambda \geq -4(d-2)$. For the case of negative mass black holes, we show that a sufficient condition for stability is given by $\lambda \geq -2(d-3)$.Comment: 20 pages, Latex, v2 refined analysis of boundary conditions in dimensions 4,5,6, additional reference

Gaze in a real-world social interaction: A dual eye-tracking study

People communicate using verbal and non-verbal cues, including gaze cues. Gaze allocation can be influenced by social factors; however, most research on gaze cueing has not considered these factors. The presence of social roles was manipulated in a natural, everyday collaborative task while eye movements were measured. In pairs, participants worked together to make a cake. Half of the pairs were given roles (“Chef” or “Gatherer”) and the other half were not. Across all participants we found, contrary to the results of static-image experiments, that participants spent very little time looking at each other, challenging the generalisability of the conclusions from lab-based paradigms. However, participants were more likely than not to look at their partner when receiving an instruction, highlighting the typical coordination of gaze cues and verbal communication in natural interactions. The mean duration of instances in which the partners looked at each other (partner gaze) was longer in the roles condition, and these participants were quicker to align their gaze with their partners (shared gaze). In addition, we found some indication that when hearing spoken instructions, listeners in the roles condition looked at the speaker more than listeners in the no roles condition. We conclude that social context can affect our gaze behaviour during a social interaction

Gauge fixing and Gribov copies in pure Yang-Mills on a circle

%In order to understand how gauge fixing can be affected on the %lattice, we first study a simple model of pure Yang-mills theory on a %cylindrical spacetime [$SU(N)$ on $S^1 \times$ {\bf R}] where the %gauge fixed subspace is explicitly displayed. On the way, we find that %different gauge fixing procedures lead to different Hamiltonians and %spectra, which however coincide under a shift of states. The lattice %version of the model is compared and lattice gauge fixing issues are %discussed. (---TALK GIVEN AT LATTICE 92---AMSTERDAM, 15 SEPT. 92)Comment: 4 pages + 1 PostScript figure (appended), UVA-ITFA-92-34/ETH-IPS-92-22. --just archiving published versio

Use of Markov Chains to Design an Agent Bidding Strategy for Continuous Double Auctions

As computational agents are developed for increasingly complicated e-commerce applications, the complexity of the decisions they face demands advances in artificial intelligence techniques. For example, an agent representing a seller in an auction should try to maximize the seller's profit by reasoning about a variety of possibly uncertain pieces of information, such as the maximum prices various buyers might be willing to pay, the possible prices being offered by competing sellers, the rules by which the auction operates, the dynamic arrival and matching of offers to buy and sell, and so on. A naive application of multiagent reasoning techniques would require the seller's agent to explicitly model all of the other agents through an extended time horizon, rendering the problem intractable for many realistically-sized problems. We have instead devised a new strategy that an agent can use to determine its bid price based on a more tractable Markov chain model of the auction process. We have experimentally identified the conditions under which our new strategy works well, as well as how well it works in comparison to the optimal performance the agent could have achieved had it known the future. Our results show that our new strategy in general performs well, outperforming other tractable heuristic strategies in a majority of experiments, and is particularly effective in a 'seller?s market', where many buy offers are available

Are we missing the target? Are we aiming too low? What are the aerobic exercise prescriptions and their effects on markers of cardiovascular health and systemic inflammation in patients with knee osteoarthritis? A systematic review and meta-analysis

Objectives We systemically reviewed published studies that evaluated aerobic exercise interventions in patients with knee osteoarthritis (OA) to: (1) report the frequency, intensity, type and time (FITT) of exercise prescriptions and (2) quantify the changes in markers of cardiovascular health and systemic inflammation. Data sources PubMed, CINAHL, Scopus; inception to January 2019. Eligibility criteria Randomised clinical trials (RCT), cohort studies, case series. Design We summarised exercise prescriptions for all studies and calculated effect sizes with 95% CIs for between-group (RCTs that compared exercise and control groups) and within-group (pre-post exercise) differences in aerobic capacity (VO2), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and inflammatory markers (interleukin-6 (IL-6), tumour necrosis factor-alpha). We pooled results where possible using random effects models. Results Interventions from 49 studies were summarised; 8% (4/49) met all FITT guidelines; 16% (8/49) met all or most FITT guidelines. Fourteen studies (10 RCTs) reported at least one marker of cardiovascular health or systemic inflammation. Mean differences (95% CI) indicated a small to moderate increase in VO2(0.84 mL/min/kg; 95% CI 0.37 to 1.31), decrease in HR (-3.56 beats per minute; 95% CI -5.60 to -1.52) and DBP (-4.10 mm Hg; 95% CI -4.82 to -3.38) and no change in SBP (-0.36 mm Hg; 95% CI -3.88 to 3.16) and IL-6 (0.37 pg/mL; 95% CI -0.11 to 0.85). Within-group differences were also small to moderate. Conclusions In studies of aerobic exercise in patients with knee OA, very few interventions met guideline-recommended dose; there were small to moderate changes in markers of cardiovascular health and no decrease in markers of systemic inflammation. These findings question whether aerobic exercise is being used to its full potential in patients with knee OA. PROSPERO registration number CRD42018087859

Quasinormal Modes and Black Hole Quantum Mechanics in 2+1 Dimensions

We explore the relationship between classical quasinormal mode frequencies and black hole quantum mechanics in 2+1 dimensions. Following a suggestion of Hod, we identify the real part of the quasinormal frequencies with the fundamental quanta of black hole mass and angular momentum. We find that this identification leads to the correct quantum behavior of the asymptotic symmetry algebra, and thus of the dual conformal field theory. Finally, we suggest a further connection between quasinormal mode frequencies and the spectrum of a set of nearly degenerate ground states whose multiplicity may be responsible for the Bekenstein-Hawking entropy.Comment: 8 pages, LaTeX; references added and corrected, introduction and conclusion slightly expande

Area Spectrum of Extremal Reissner-Nordstr\"om Black Holes from Quasi-normal Modes

Using the quasi-normal modes frequency of extremal Reissner-Nordstr\"om black holes, we obtain area spectrum for these type of black holes. We show that the area and entropy black hole horizon are equally spaced. Our results for the spacing of the area spectrum differ from that of schwarzschild black holes.Comment: 6 pages, no figure, accepted for publication in Phys. Rev.