Local well-posedness for membranes in the light cone gauge

In this paper we consider the classical initial value problem for the bosonic membrane in light cone gauge. A Hamiltonian reduction gives a system with one constraint, the area preserving constraint. The Hamiltonian evolution equations corresponding to this system, however, fail to be hyperbolic. Making use of the area preserving constraint, an equivalent system of evolution equations is found, which is hyperbolic and has a well-posed initial value problem. We are thus able to solve the initial value problem for the Hamiltonian evolution equations by means of this equivalent system. We furthermore obtain a blowup criterion for the membrane evolution equations, and show, making use of the constraint, that one may achieve improved regularity estimates.Comment: 29 page

Phase separation in the two-dimensional electron liquid in MOSFETs

We show that the existence of an intermediate phase between the Fermi liquid and the Wigner crystal phases is a generic property of the two-dimensional pure electron liqd in MOSFET's at zero temperature. The physical reason for the existence of these phases is a partial separation of the uniform phases. We discuss properties of these phases and a possible explanation of experimental results on transport properties of low density electron gas in Si MOSFET's. We also argue that in certain range of parameters the partial phase separation corresponds to a supersolid phas e discussed in [AndreevLifshitz].Comment: 11 pages, 3 figure

Manifestation of triplet superconductivity in superconductor-ferromagnet structures

We study proximity effects in a multilayered superconductor/ferromagnet (S/F) structure with arbitrary relative directions of the magnetization ${\bf M}$. If the magnetizations of different layers are collinear the superconducting condensate function induced in the F layers has only a singlet component and a triplet one with a zero projection of the total magnetic moment of the Cooper pairs on the ${\bf M}$ direction. In this case the condensate penetrates the F layers over a short length $\xi_J$ determined by the exchange energy $J$. If the magnetizations ${\bf M}$ are not collinear the triplet component has, in addition to the zero projection, the projections $\pm1$. The latter component is even in the momentum, odd in the Matsubara frequency and penetrates the F layers over a long distance that increases with decreasing temperature and does not depend on $J$ (spin-orbit interaction limits this length). If the thickness of the F layers is much larger than $\xi_J$, the Josephson coupling between neighboring S layers is provided only by the triplet component, so that a new type of superconductivity arises in the transverse direction of the structure. The Josephson critical current is positive (negative) for the case of a positive (negative) chirality of the vector ${\bf M}$. We demonstrate that this type of the triplet condensate can be detected also by measuring the density of states in F/S/F structures.Comment: 14 pages; 9 figures. Final version, to be published in Phys. Rev.

Home dialysis: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) controversies conference

Home dialysis modalities (home hemodialysis [HD] and peritoneal dialysis [PD]) are associated with greater patient autonomy and treatment satisfaction compared with in-center modalities, yet the level of home-dialysis use worldwide is low. Reasons for limited utilization are context-dependent, informed by local resources, dialysis costs, access to healthcare, health system policies, provider bias or preferences, cultural beliefs, individual lifestyle concerns, potential care-partner time, and financial burdens. In May 2021, KDIGO (Kidney Disease: Improving Global Outcomes) convened a controversies conference on home dialysis, focusing on how modality choice and distribution are determined and strategies to expand home-dialysis use. Participants recognized that expanding use of home dialysis within a given health system requires alignment of policy, fiscal resources, organizational structure, provider incentives, and accountability. Clinical outcomes across all dialysis modalities are largely similar, but for specific clinical measures, one modality may have advantages over another. Therefore, choice among available modalities is preference-sensitive, with consideration of quality of life, life goals, clinical characteristics, family or care-partner support, and living environment. Ideally, individuals, their care-partners, and their healthcare teams will employ shared decision-making in assessing initial and subsequent kidney failure treatment options. To meet this goal, iterative, high-quality education and support for healthcare professionals, patients, and care-partners are priorities. Everyone who faces dialysis should have access to home therapy. Facilitating universal access to home dialysis and expanding utilization requires alignment of policy considerations and resources at the dialysis-center level, with clear leadership from informed and motivated clinical teams

Health impact and cost-effectiveness of achieving the national salt and sugar reduction initiative voluntary sugar reduction targets in the united states: A microsimulation study

BACKGROUND: High intake of added sugar is linked to weight gain and cardiometabolic risk. In 2018, the US National Salt and Sugar Reduction Initiative proposed government-supported voluntary national sugar reduction targets. This intervention's potential effects and cost-effectiveness are unclear. METHODS: A validated microsimulation model, CVD-PREDICT (Cardiovascular Disease Policy Model for Risk, Events, Detection, Interventions, Costs, and Trends), coded in C++, was used to estimate incremental changes in type 2 diabetes, cardiovascular disease (CVD), quality-adjusted life-years (QALYs), costs, and cost-effectiveness of the US National Salt and Sugar Reduction Initiative policy. The model was run at the individual level, incorporating the annual probability of each person's transition between health statuses on the basis of risk factors. The model incorporated national demographic and dietary data from the National Health and Nutrition Examination Survey across 3 cycles (2011 through 2016), added sugar-related diseases from meta-analyses, and policy costs and health-related costs from established sources. A simulated nationally representative US population was created and followed until age 100 years or death, with 2019 as the year of intervention start. Findings were evaluated over 10 years and a lifetime from health care and societal perspectives. Uncertainty was evaluated in a 1-way analysis by assuming 50% industry compliance and probabilistic sensitivity analyses through a second-order Monte Carlo approach. Model outputs included averted diabetes cases, CVD events and CVD deaths, QALYs gained, and formal health care cost savings, stratified by age, race, income, and education. RESULTS: Achieving the US National Salt and Sugar Reduction Initiative sugar reduction targets could prevent 2.48 million CVD events, 0.49 million CVD deaths, and 0.75 million diabetes cases; gain 6.67 million QALYs; and save $160.88 billion net costs from a societal perspective over a lifetime. The policy became cost-effective (<150 000/QALYs) at 6 years, highly costeffective (<50 000/QALYs) at 7 years, and cost-saving at 9 years. Results were robust from a health care perspective, with lower (50%) industry compliance, and in probabilistic sensitivity analyses. The policy could also reduce disparities, with greatest estimated health gains per million adults among Black or Hispanic individuals, lower income, and less educated Americans. CONCLUSIONS: Implementing and achieving the US National Salt and Sugar Reduction Initiative sugar reformation targets could generate substantial health gains, equity gains, and cost savings. © 2021 American Heart Association, Inc

SimCommSys: taking the errors out of error‐correcting code simulations

In this study, we present SimCommSys, a simulator of communication systems that we are releasing under an open source license. The core of the project is a set of C + + libraries defining communication system components and a distributed Monte Carlo simulator. Of principal interest is the error-control coding component, where various kinds of binary and non-binary codes are implemented, including turbo, LDPC, repeat-accumulate and Reed–Solomon. The project also contains a number of ready-to-build binaries implementing various stages of the communication system (such as the encoder and decoder), a complete simulator and a system benchmark. Finally, SimCommSys also provides a number of shell and python scripts to encapsulate routine use cases. As long as the required components are already available in SimCommSys, the user may simulate complete communication systems of their own design without any additional programming. The strict separation of development (needed only to implement new components) and use (to simulate specific constructions) encourages reproducibility of experimental work and reduces the likelihood of error. Following an overview of the framework, we provide some examples of how to use the framework, including the implementation of a simple codec, the specification of communication systems and their simulation