Different Contexts, Different Risk Preferences?

We examine the stability of risk preferences across contexts involving different stakes. Using data on households\u27 deductible choices in three property insurance coverages and their limit choices in two liability insurance coverages, we assess the stability across the five contexts in the ordinal ranking of the households\u27 willingness to bear risk. We find evidence of stability across contexts involving stakes of the same magnitude, but not across contexts involving stakes of very different magnitudes. Our results appear to be robust to heterogeneity in wealth and access to credit, complicating seemingly ready explanations

Unsupervised Discovery of Parts, Structure, and Dynamics

Humans easily recognize object parts and their hierarchical structure by watching how they move; they can then predict how each part moves in the future. In this paper, we propose a novel formulation that simultaneously learns a hierarchical, disentangled object representation and a dynamics model for object parts from unlabeled videos. Our Parts, Structure, and Dynamics (PSD) model learns to, first, recognize the object parts via a layered image representation; second, predict hierarchy via a structural descriptor that composes low-level concepts into a hierarchical structure; and third, model the system dynamics by predicting the future. Experiments on multiple real and synthetic datasets demonstrate that our PSD model works well on all three tasks: segmenting object parts, building their hierarchical structure, and capturing their motion distributions.Comment: ICLR 2019. The first two authors contributed equally to this wor

Flow-based assembly of nucleic acid-loaded polymer nanoparticles

Since the development of messenger RNA (mRNA)-based SARS-CoV-2 (COVID-19) vaccines, there is increased public awareness of the importance of nanoparticles, in this case lipid nanoparticles, to ensure safe delivery of an active compound. To ensure the formation of high-quality nanoparticles with reproducible results, these lipid nanoparticles are assembled with the nucleic acid drug using flow-based devices. Although flow assembly using lipid nanoparticles for nucleic acid delivery is well described in the literature, only a few examples use polymers. This is surprising because the field of polymers for nucleic acid delivery is substantial as hundreds of polymers for nucleic acid delivery have been reported in the literature. In this review, we discuss several aspects of flow-based assembly of nucleic acid-loaded polymer nanoparticles. Initially, we introduce the concept of chip-based or capillary-based systems that can be either used as single-phase or multiphase systems. Initially, researchers have to choose the type of mixing, which can be active or passive. The type of flow, laminar or turbulent, also significantly affects the quality of the nanoparticles. We then present the type of polymers that have so far been assembled with mRNA, small interfering RNA (siRNA) or plasmid DNA (pDNA) using flow devices. We discuss effects such as flow rate, concentration and polymer lengths on the outcome. To conclude, we highlight how flow assembly is an excellent way to generate well-defined nanoparticles including polyplexes in a reproducible manner

Metabolite concentrations, fluxes and free energies imply efficient enzyme usage.

In metabolism, available free energy is limited and must be divided across pathway steps to maintain a negative ΔG throughout. For each reaction, ΔG is log proportional both to a concentration ratio (reaction quotient to equilibrium constant) and to a flux ratio (backward to forward flux). Here we use isotope labeling to measure absolute metabolite concentrations and fluxes in Escherichia coli, yeast and a mammalian cell line. We then integrate this information to obtain a unified set of concentrations and ΔG for each organism. In glycolysis, we find that free energy is partitioned so as to mitigate unproductive backward fluxes associated with ΔG near zero. Across metabolism, we observe that absolute metabolite concentrations and ΔG are substantially conserved and that most substrate (but not inhibitor) concentrations exceed the associated enzyme binding site dissociation constant (Km or Ki). The observed conservation of metabolite concentrations is consistent with an evolutionary drive to utilize enzymes efficiently given thermodynamic and osmotic constraints

Theories of Naval Blockades and Their Application in the Twenty-First Century

Technological advancements in weapon systems, platforms, and communications raise questions about the continuing relevance of blockade strategies and tactics that were developed during previous eras of naval warfare. If modern navies are using a centuries-old strategy, to what extent do the old rules still apply

Design of Residential Hydrogen Fueling System in UB Bodine Hall

Pollution and emission from the burning fossil fuel already became a serious environmental issue. To solve this problem, more and more green energy or renewable energy has been used into and impact onto modern society. For instance, solar energy, hydrogen, and wind turbine gradually play an important role in manufactory industry. Using hydrogen fueling system for the residential is good for environments, because the students whose live in dormitory have their own cars. If those cars are hydrogen car, they can use the fueling system to supply the hydrogen to the cars. They do not have to go the hydrogen gas station to gas the hydrogen. And using hydrogen is more eco friendly than using the burning fossil. This design is to produce hydrogen for the hydrogen cars belonged to the residents of Bodine Hall, a dormitory at the UB, through a solar energy powered system. In this design, a Proton-Exchange-Membrane (PEM) eletrolyzer is used as a hydrogen generator, solar panels are used to convert solar energy to electricity for electrolyzer, and a hydrogen compressor system is used to compress hydrogen and store it