REITs: Dual Asset Markets and “Arbitrage”

Dual asset markets are unique to real estate. When the assets are held by a real estate investment trust (REIT), properties trade in property markets while claims on cash flows from these assets trade in a public equity market. If the two parallel markets are in disagreement regarding the total market value of underlying assets, then REIT managers are faced with inter-market arbitrage opportunities. If a REIT’s shares trade at premium in the stock market relative to the net asset value (NAV) of the underlying assets, the arbitrage opportunity can be exploited by issuing new equity in the stock market and purchasing assets in the property market with the proceeds from new equity. If a REIT’s shares trade at a discount to NAV, the arbitrage opportunity is achieved by selling assets in the local property market and repurchasing shares of common equity. In this dissertation, I investigate whether REIT managers attempt to exploit such opportunities. Specifically, I identify whether share price premiums or discounts to NAV influence the propensity of REIT managers to purchase versus sell assets in the property market. In addition, I investigate whether the market-wide premiums to NAV influence the relative transaction prices paid for the property while carefully controlling for the sample selection issue in the analyses. Further, since this information is feasible to evaluate by analysts, I investigate how investors in the stock market react when REIT managers issue new equity during periods of premiums to NAV. The analyses use property level transaction data for commercial real estate asset values and stock price data for REITs

A bi-polymer micro one-way valve

Abstract We have developed an in-plane bi-polymer check-valve for controlling microfluidic flow and preventing contamination between solutions by utilizing the elastic force of a swollen hydrogel. The valve was created using microfluidic tectonics, a fabrication procedure that allows construction of microscale components and autonomous systems using liquid-phase photopolymerization and in situ fabrication. The valve is composed of rigid parts (poly isobornyl acrylate) that provide a base frame, and compliant parts (hydrogel) that seal off the channel. The rigid part was fabricated by filling a polycarbonate cartridge with the isobornyl acrylate based prepolymer followed by UV light exposure through a photomask forming a chamber. To obtain well-defined chamber walls, a double exposing method (first exposure under lower UV dosage, then second exposure after filling the formed channel with DI water) was applied. Next, the chamber was filled with the hydrogel prepolymer mixture and exposed to UV light through a valve mask to define the compliant component of the device, resulting in an in-plane bi-polymer structure. The valve is actively assembled in situ providing precise sealing using low resolution lithography fabrication methods. Valve performance can be adjusted by varying the device geometry. Due to its in-plane structure and in situ fabrication process, microfluidic devices incorporating microvalves can be designed and fabricated conveniently

Neuromodulatory state and sex specify alternative behaviors through antagonistic synaptic pathways in C. elegans

SUMMARY Pheromone responses are highly context dependent. For example, the C. elegans pheromone ascaroside C9 (ascr#3) is repulsive to wild-type hermaphrodites, attractive to wild-type males, and usually neutral to ''social'' hermaphrodites with reduced activity of the npr-1 neuropeptide receptor gene. We show here that these distinct behavioral responses arise from overlapping push-pull circuits driven by two classes of pheromone-sensing neurons. The ADL sensory neurons detect C9 and, in wild-type hermaphrodites, drive C9 repulsion through their chemical synapses. In npr-1 mutant hermaphrodites, C9 repulsion is reduced by the recruitment of a gap junction circuit that antagonizes ADL chemical synapses. In males, ADL sensory responses are diminished; in addition, a second pheromone-sensing neuron, ASK, antagonizes C9 repulsion. The additive effects of these antagonistic circuit elements generate attractive, repulsive, or neutral pheromone responses. Neuronal modulation by circuit state and sex, and flexibility in synaptic output pathways, may permit small circuits to maximize their adaptive behavioral outputs

Neurotransmitter-Induced Excitatory and Inhibitory Functions in Artificial Synapses

© 2022 Wiley-VCH GmbHNeurotransmitters control signal transmission in the nervous system. The signals of neuron cells can be excited or inhibited based on the types of neurotransmitters that are released from pre-synaptic neurons. The balance of the excitatory and inhibitory synaptic responses has important implications for the versatility, plasticity, and parallel computing characteristics of the nervous system. Emulating the excitatory–inhibitory balancing characteristics is one way to establish the versatility and plasticity characteristics of the brain. In this study, the authors develop artificial synapses to emulate the excitatory and inhibitory functions of biological synapses using electrochemical reactions between the channel and neurotransmitter solutions. The devices show excitatory and inhibitory characteristics depending on types of neurotransmitter solutions. The interaction between these two types of synaptic responses is employed for emulating the excitatory–inhibitory balance characteristics. The devices emulate the multifunctional characteristics of biological synapses, resulting in their potential for use in bio-realistic neuromorphic devices.11Nsciescopu

An efficient algorithm for the non-convex penalized multinomial logistic regression

In this paper, we introduce an efficient algorithm for the non-convex penalized multinomial logistic regression that can be uniformly applied to a class of non-convex penalties. The class includes most non-convex penalties such as the smoothly clipped absolute deviation, minimax concave and bridge penalties. The algorithm is developed based on the concave-convex procedure and modified local quadratic approximation algorithm. However, usual quadratic approximation may slow down computational speed since the dimension of the Hessian matrix depends on the number of categories of the output variable. For this issue, we use a uniform bound of the Hessian matrix in the quadratic approximation. The algorithm is available from the R package ncpen developed by the authors. Numerical studies via simulations and real data sets are provided for illustration

Interfacial Formation of Porous Membranes with Poly(ethylene glycol) in a Microfluidic Environment

ABSTRACT: In a microfluidic environment, the liquidliquid interface, formed by laminar flows of immiscible solutions, can be used to generate thin membranes via interfacial polymerization. Because these thin nylon membranes have a very small pore size or lack porosity entirely, their utilization in some biological applications is greatly limited. We introduce an in situ fabrication method using the interfacial reaction of a two-phase system to generate a porous nylon membrane. The membranes were characterized with scanning electron microscopy and fluorescent beads. Scanning electron microscopy micrographs verified the asymmetrical structure of the porous membrane, and the membrane pore sizes ranged from 0.1 to 1 lm

Liquid-Based Memory Devices for Next-Generation Computing

Liquid-based devices have emerged as bioinspired neuromorphic applications owing to their high ion-diffusion coefficients, diverse structures, and controllable ion-exchange reactions. By engineering and modifying liquid materials, multifunctional liquid-based computing devices have been developed for next-generation memory and neuromorphic devices. The unique properties of liquids make them feasible for memory functions and various synaptic applications, such as emulating synaptic plasticity, homeostasis, and action potentials. Utilizing liquids in computing devices provides a promising and versatile platform for high-performance memory devices and enables the emulation of bioinspired computing functions. In this Spotlight, we highlight recent advances in liquid-based memory devices and focus on synaptic applications. We then discuss possible array structures and scaling-down technologies for liquid-based devices. Finally, the challenges and future prospects of liquid-based devices are discussed.11Nsciescopu