100 research outputs found
Rogue Trends in Sovereign Debt: Argentina, Vulture Funds, and Pari Passu Under New York Law
Higher-Dimensional Black Holes: Hidden Symmetries and Separation of Variables
In this paper, we discuss hidden symmetries in rotating black hole
spacetimes. We start with an extended introduction which mainly summarizes
results on hidden symmetries in four dimensions and introduces Killing and
Killing-Yano tensors, objects responsible for hidden symmetries. We also
demonstrate how starting with a principal CKY tensor (that is a closed
non-degenerate conformal Killing-Yano 2-form) in 4D flat spacetime one can
"generate" 4D Kerr-NUT-(A)dS solution and its hidden symmetries. After this we
consider higher-dimensional Kerr-NUT-(A)dS metrics and demonstrate that they
possess a principal CKY tensor which allows one to generate the whole tower of
Killing-Yano and Killing tensors. These symmetries imply complete integrability
of geodesic equations and complete separation of variables for the
Hamilton-Jacobi, Klein-Gordon, and Dirac equations in the general
Kerr-NUT-(A)dS metrics.Comment: 33 pages, no figures, updated references and corrected typo
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Holistic Health Status Questionnaire: developing a measure from a Hong Kong Chinese population
The Head-On Collision of Gasperini and the Derailment of Erie: Exposing the Futility of the Accommodation Doctrine
The Admissibility of Hearsay Evidence in New York State Sex Offender Civil Commitment Hearings After <i>State v. Floyd Y.</i>: Finding a Balance Between Promoting the General Welfare of Sexual Assault Victims and Providing Due Process of Law
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