Leveraging Local Distributions in Mendelian Randomization: Uncertain Opinions are Invalid

Mendelian randomization (MR) considers using genetic variants as instrumental variables (IVs) to infer causal effects in observational studies. However, the validity of causal inference in MR can be compromised when the IVs are potentially invalid. In this work, we propose a new method, MR-Local, to infer the causal effect in the existence of possibly invalid IVs. By leveraging the distribution of ratio estimates around the true causal effect, MR-Local selects the cluster of ratio estimates with the least uncertainty and performs causal inference within it. We establish the asymptotic normality of our estimator in the two-sample summary-data setting under either the plurality rule or the balanced pleiotropy assumption. Extensive simulations and analyses of real datasets demonstrate the reliability of our approach

Emerging applications of integrated optical microcombs for analogue RF and microwave photonic signal processing

We review new applications of integrated microcombs in RF and microwave photonic systems. We demonstrate a wide range of powerful functions including a photonic intensity high order and fractional differentiators, optical true time delays, advanced filters, RF channelizer and other functions, based on a Kerr optical comb generated by a compact integrated microring resonator, or microcomb. The microcomb is CMOS compatible and contains a large number of comb lines, which can serve as a high performance multiwavelength source for the transversal filter, thus greatly reduce the cost, size, and complexity of the system. The operation principle of these functions is theoretically analyzed, and experimental demonstrations are presented.Comment: 16 pages, 8 figures, 136 References. Photonics West 2018 invited paper, expanded version. arXiv admin note: substantial text overlap with arXiv:1710.00678, arXiv:1710.0861

Liquid-Liquid Phase Separation in an Elastic Network

Living and engineered systems rely on the stable coexistence of two interspersed liquid phases. Yet surface tension drives their complete separation. Here we show that stable droplets of uniform and tuneable size can be produced through arrested phase separation in an elastic matrix. Starting with an elastic polymer network swollen by a solvent mixture, we change the temperature or composition to drive demixing. Droplets nucleate and grow to a stable size that is tuneable by the network cross-linking density, the cooling rate, and the composition of the solvent mixture. We discuss thermodynamic and mechanical constraints on the process. In particular, we show that the threshold for macroscopic phase separation is altered by the elasticity of the polymer network, and we highlight the role of internuclear correlations in determining the droplet size and polydispersity. This phenomenon has potential applications ranging from colloid synthesis and structural colour to phase separation in biological cells.Comment: 6 figure

Sustainable Supply Chain Management with NGOs, NPOs, and Charity Organizations: A Systematic Review and Research Agenda

With the gradually increased awareness of sustainability development, external organizations, including non-governmental organizations (NGOs), non-profit organizations (NPOs), and charity organizations, play an increasingly crucial role in sustainable supply chain management (SSCM). The participation of external organizations not only helps the firms to improve reputation, but also regulates and improves their SSCM. Based on this motivation, we identify the major research domains and examine each domain's evolution by using the objective review methods, including Citation Network Analysis and Main Path Analysis in this literature review paper. Five research domains are recognized, namely, “sustainable supply chain framework design”, “supply chain coordination/collaboration”, “closed-loop supply chain”, “regulation”, and “subsidy and donation”. We review the most influential papers in each research domain to show the evolution of these studies. Based on our review findings, we successfully propose four future research agendas with eight specific issues and innovatively establish a new research framework. The outputs of this review paper can guide the researchers on future search topics and contribute to the development of SSCM with the consideration of organizations.</p

Towards Accelerating High-Order Stencils on Modern GPUs and Emerging Architectures with a Portable Framework

PDE discretization schemes yielding stencil-like computing patterns are commonly used for seismic modeling, weather forecast, and other scientific applications. Achieving HPC-level stencil computations on one architecture is challenging, porting to other architectures without sacrificing performance requires significant effort, especially in this golden age of many distinctive architectures. To help developers achieve performance, portability, and productivity with stencil computations, we developed StencilPy. With StencilPy, developers write stencil computations in a high-level domain-specific language, which promotes productivity, while its backends generate efficient code for existing and emerging architectures, including NVIDIA, AMD, and Intel GPUs, A64FX, and STX. StencilPy demonstrates promising performance results on par with hand-written code, maintains cross-architectural performance portability, and enhances productivity. Its modular design enables easy configuration, customization, and extension. A 25-point star-shaped stencil written in StencilPy is one-quarter of the length of a hand-crafted CUDA code and achieves similar performance on an NVIDIA H100 GPU