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We investigate the effect of large magnetic fields on the (2+1)-dimensional reduced-magnetohydrodynamical expansion of hot and dense nuclear matter produced in √sNN=200 GeV Au+Au collisions. For the sake of simplicity, we consider the case where the magnetic field points in the direction perpendicular to the reaction plane. We also consider this field to be external, with energy density parametrized as a two-dimensional Gaussian. The width of the Gaussian along the directions orthogonal to the beam axis varies with the centrality of the collision. The dependence of the magnetic field on proper time (τ) for the case of zero electrical conductivity of the QGP is parametrized following Deng et al. [Phys. Rev. C 85, 044907 (2012)], and for finite electrical conductivity following Tuchin [Phys. Rev. C 88, 024911 (2013)]. We solve the equations of motion of ideal hydrodynamics for such an external magnetic field. For collisions with nonzero impact parameter we observe considerable changes in the evolution of the momentum eccentricities of the fireball when comparing the case when the magnetic field decays in a conducting QGP medium and when no magnetic field is present. The elliptic-flow coefficient v2 of π- is shown to increase in the presence of an external magnetic field and the increment in v2 is found to depend on the evolution and the initial magnitude of the magnetic field. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "The high cost of prescription drugs in the U.S.: Origins and prospects for reform," by A. S. Kesselheim and colleagues in a 2016 issue.

The recently proposed connection between the Lorentz invariance of stability and the speed of signal propagation has been tested for a first-order relativistic dissipative hydrodynamic theory. The fact that the stability situation in different reference frames agrees with each other only as long as the signal propagation respects causality, has been explicitly established for the theory, which is microscopically derived from the covariant kinetic equation in general hydrodynamic frames with arbitrary momentum-dependent interactions. [ABSTRACT FROM AUTHOR]

Fluctuations in the initial transverse energy-density distribution lead to anisotropic flows as observed in central high-energy heavy-ion collisions. Studies of longitudinal fluctuations of the anisotropic flows can shed further light on the initial conditions and dynamical evolution of the hot quark-gluon matter in these collisions. Correlations between anisotropic flows with varying pseudorapidity gaps in Pb + Pb collisions at the CERN Large Hadron Collider are investigated using both an event-by-event (3 + 1)-dimensional ideal hydrodynamical model with fluctuating initial conditions and a multiphase transport (AMPT) Monte Carlo model for high-energy heavyion collisions. Anisotropic flows at different pseudorapidities are found to become significantly decorrelated with increasing pseudorapidity gaps due to longitudinal fluctuations in the initial states of heavy-ion collisions. The longitudinal correlation of the elliptic flow shows a strong centrality dependence while the correlation of the triangular flow is independent of the centrality. Longitudinal fluctuations as a source of the decorrelation are further shown to consist of a twist or gradual rotation in flow angles between the forward and backward direction and additional fluctuations on top of the twist. Within the AMPT model, longitudinal correlations of anisotropic flows are also found to depend on the value of partonic cross sections. The implications of constraining the initial conditions and shear viscosity to entropy density ratio of the partonic matter in high-energy heavy-ion collisions are also discussed. [ABSTRACT FROM AUTHOR]

Centrality dependence of charged particles multiplicity, transverse momentum spectra, and integrated and differential elliptic flow in √sNN = 200 GeV Au+Au collisions are analyzed using event-by-event ideal hydrodynamics. The Monte Carlo Glauber model of initial condition, constrained to reproduce experimental charged particle's multiplicity in 0%-10% Au+Au collisions, reasonably well reproduces all the experimental observables, e.g., centrality dependence of charged particle multiplicity, and integrated and differential elliptic flow. Model predictions for higher flow harmonics, v3, v4, however, overestimate the experimental data, more in the peripheral collisions than in the central collisions. Correlation between initial (spatial) asymmetry measures and flow coefficients are also studied. With the exception of the elliptic flow, for all the higher flow coefficients (vn,n = 3-5), correlation is reduced with collision centrality. In peripheral collisions, higher flow coefficients are only weakly correlated to the asymmetry measures. Elliptic flow, however, remains strongly correlated with initial eccentricity in all the collision centralities. [ABSTRACT FROM AUTHOR]

We derive the relativistic non-resistive, viscous second-order magnetohydrodynamic equations for the dissipative quantities using the relaxation time approximation. The Boltzmann equation is solved for a system of particles and antiparticles using Chapman-Enskog like gradient expansion of the single-particle distribution function truncated at second order. In the first order, the transport coefficients are independent of the magnetic field. In the second-order, new transport coefficients that couple magnetic field and the dissipative quantities appear which are different from those obtained in the 14-moment approximation [1] in the presence of a magnetic field. However, in the limit of the weak magnetic field, the form of these equations are identical to the 14-moment approximation albeit with different values of these coefficients. We also derive the anisotropic transport coefficients in the Navier-Stokes limit. [ABSTRACT FROM AUTHOR]

We investigate the decorrelation of 2nd and 3rd order anisotropic flow for charged particles in two different pseudo rapidity ( η ) windows by varying the pseudo rapidity gap, in an event-by-event (3+1)D ideal hydrodynamic model, with fluctuating initial conditions from A Multi-Phase Transport (AMPT) model. We visualize the parton distribution at initial state for Pb+Pb collisions at LHC and Au+Au collisions at RHIC, and demonstrate the longitudinal fluctuations originating from the asymmetry between forward and backward going participants, the fluctuations of the string length and the fluctuations due to finite number of partons at different beam energies. The decorrelation of anisotropic flow of final hadrons with large η gaps is found to originate from the spatial decorrelation along the longitudinal direction in the AMPT initial conditions through hydrodynamic evolution. The agreement between our results and recent CMS data in most centralities suggests that the string-like mechanism of initial parton production in AMPT model captures the initial longitudinal fluctuation that is responsible for the measured decorrelation of anisotropic flow in Pb+Pb collisions at LHC. Our predictions for Au+Au collisions at the highest RHIC energy show stronger longitudinal decorrelation than at LHC, indicating larger longitudinal fluctuations at lower beam energies. [ABSTRACT FROM AUTHOR]

We have calculated the temperature dependence of shear η and bulk ζ viscosities of quark matter due to quark-meson fluctuations. The quark thermal width originating from quantum fluctuations of quark-π and quark-σ loops at finite temperature is calculated with the formalism of real-time thermal field theory. Temperature-dependent constituent-quark and meson masses and quark-meson couplings are obtained in the Nambu-Jona-Lasinio model. We found a nontrivial influence of the temperature-dependent masses and couplings on the Landau-cut structure of the quark self-energy. Our results for the ratios η/s and ζ/s, where s is the entropy density (also determined in the Nambu-Jona-Lasinio model in the quasiparticle approximation), are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η/s has a minimum very close to the quantum lower bound, η/s=1/4π. [ABSTRACT FROM AUTHOR]

We investigate the causality and the stability of the relativistic viscous non-resistive magneto-hydrodynamics in the framework of the Israel-Stewart (IS) second-order theory, and also within a modified IS theory which incorporates the effect of magnetic fields in the relaxation equations of the viscous stress. We compute the dispersion relation by perturbing the fluid variables around their equilibrium values. In the ideal magnetohydrodynamics limit, the linear dispersion relation yields the well-known propagating modes: the Alfvén and the magneto-sonic modes. In the presence of bulk viscous pressure, the causality bound is found to be independent of the magnitude of the magnetic field. The same bound also remains true, when we take the full non-linear form of the equation using the method of characteristics. In the presence of shear viscous pressure, the causality bound is independent of the magnitude of the magnetic field for the two magneto-sonic modes. The causality bound for the shear-Alfvén modes, however, depends both on the magnitude and the direction of the propagation. For modified IS theory in the presence of shear viscosity, new non-hydrodynamic modes emerge but the asymptotic causality condition is the same as that of IS. In summary, although the magnetic field does influence the wave propagation in the fluid, the study of the stability and asymptotic causality conditions in the fluid rest frame shows that the fluid remains stable and causal given that they obey certain asymptotic causality condition. [ABSTRACT FROM AUTHOR]

The prevailing economic paradigm, characterized by free market thinking and individualistic cultural narratives, has deeply influenced contemporary society in recent decades, including health in the United States. This paradigm, far from being natural, is iteratively intertwined with politics, social group stratification, and norms, together shaping what is known as political economy. The consequences are starkly evident in health, with millions of lives prematurely lost annually in the United States. Drawing on economic re-thinking happening in fields like climate and law, we argue for a new "common sense" towards a health-focused political economy. Central to this proposed shift is action in 3 interconnected areas: capital, care, and culture. Re-orienting capital to prioritize longer-term investments, such as in public options for health care and baby bonds, can promote health and affirmatively include historically marginalized groups. Recognizing that caregiving is economically valuable and necessary for health, approaches like local cadres of community health workers across the United States would be part of building robust caregiving infrastructures. Advancing momentum in these directions, in turn, will require displacing dominant cultural narratives. As the health arena pursues change in the face of real obstacles, recent efforts reinvigorating industrial policy and addressing concentrated market power can serve as inspiration., Competing Interests: Conflicts of interest Please see ICMJE form(s) for author conflicts of interest. These have been provided as supplementary materials., (© The Author(s) 2024. Published by Oxford University Press on behalf of Project HOPE - The People-To-People Health Foundation, Inc.)

Background: Patients face well documented problems accessing methadone from opioid treatment programs (OTPs) in the U.S., yet addressing these barriers has proven difficult due in part to the sheer number of actors governing treatment, including state authorities. Changes in federal methadone regulations during COVID-19 offer an opportunity to study the timing and extent of U.S. state opioid treatment authority (SOTA) adoption of policies expanding take home dosing for methadone treatment since March 2020., Methods: We completed a policy scan between February 23 and May 2, 2023 on state adoption and subsequent rescinding of federal regulatory exemptions for expanded take-home dosing. This scan involved three components: a policy survey of SOTAs, a freedom of information act (FOIA) request of SAMHSA, and outreach to members of National Survivors Union (NSU)'s methadone work group., Results: Of the 39 of 50 (78 %) SOTAs that responded, only 2 states (HI and MT) indicated that they never adopted federal exemptions for expanded take-home dosing. Of the 37 adopting states, all adopted the exemptions within the first month after the agency's announcement. Additionally, four SOTAs (OH, IN, FL, MS) indicated that their state subsequently rescinded expanded take-home dosing for methadone., Conclusions: Among responding states, regulations expanding take-home dosing appear to have been adopted by U.S. SOTAs in a widespread and rapid manner at the start of the COVID-19 pandemic, but some states have begun to rescind such policies. Our findings suggest that state regulators can rapidly modify OTP regulations in response to federal policy changes. SOTA policies are likely to become critical factors in the adoption of methadone treatment innovations if new federal regulatory flexibilities become permanent., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

The case of clinical trials for convalescent plasma during COVID-19 illustrates important lessons for realizing public sector approaches to biomedical research and development. These lessons, centering on mission, transparency, and spillover effects, can be translated to wider efforts to develop a "public option" for clinical trials.

Background and Objectives: Scholarship is recognized as a challenge in many family medicine residency programs. Among evaluations of scholarship curricula, few describe resident experiences of such interventions. To bridge this gap in knowledge, we measured resident confidence, satisfaction, and participation before and after implementing a new scholarship curriculum., Methods: The redesigned curriculum included a structured project timeline, resident research in progress meetings, faculty mentorship, scholarly skills workshops, and mentored journal clubs. We conducted a curriculum evaluation via surveys of residents prior to implementation and after years 1 and 2, measuring satisfaction with the scholarly environment and opportunities, and confidence and participation in specific scholarly activities using Likert scales from 1 (least confidence) to 5., Results: Compared to baseline (n=28), after 2 years (n=27) of the curriculum, residents reported increased mean confidence in critical appraisal of scientific articles (2.6±1.1 to 3.3±0.7, P=.007), carrying out a scholarly project (2.5±0.8 to 3.4±1.0, P=.005), and writing an abstract (3.0±0.8 to 3.8±0.7, P=.002). As compared to the first year, more residents in the second year participated in quality improvement projects (7.1% vs 29.6%, P=.031) and wrote conference abstracts (10.7% vs 37.0%, P=.022). Over the same period, those very satisfied with the scholarly environment increased from 0 (0%) to 8 (29.6%, P=.017). The June 2020 survey identified increased interest in scholarship because of the antiracism movement (51.9%) and COVID-19 pandemic (40.7%)., Conclusions: Implementation of a redesigned scholarship curriculum was associated with increases in family medicine resident scholarship confidence and satisfaction.