Central Banks' Asset Purchase Programs, Asset Distributions, and Endogenous Market Segmentation

This paper investigates the effects of open-market operations on the distributions of assets and prices. It offers a theoretical framework to incorporate multiple asset holdings in a tractable heterogeneous-agent model. This model features competitive search, which produces distributions of money and bond holdings as well as price dispersion among submarkets. At a high enough bond supply, the equilibrium shows segmentation in the asset market; only households with good income shocks participate in the bond market. Segmentation in the asset market is generated endogenously without assuming any rigidities or frictions in the asset market. Numerical exercises show that when the asset market is segmented, the central bank can improve welfare by purchasing bonds and supplying money

Open-Market Operations, Asset Distributions, and Endogenous Market Segmentation

This paper investigates the long-run effects of open-market operations on the distributions of assets and prices in the economy. It offers a theoretical framework to incorporate multiple asset holdings in a tractable heterogeneous-agent model, in which the central bank implements policies by changing the supply of nominal bond and money. This model features competitive search, which produces distributions of money and bond holdings as well as price dispersion among submarkets. At a high enough bond supply, the equilibrium shows segmentation in the asset market; only households with good income shocks participate in the bond market. When deciding whether to participate in the asset market, households compare liquidity services provided by money with returns on bond. Segmentation in the asset market is generated endogenously without assuming any rigidities or frictions in the asset market. In an equilibrium with a segmented asset market, open-market operations affect households’ participation decisions and, therefore, have real effects on the distribution of assets and prices in the economy. Numerical exercises show that the central bank can improve welfare by purchasing bonds and supplying money when the asset market is segmented

Central Banks' Asset Purchase Programs, Asset Distributions, and Endogenous Market Segmentation

This paper investigates the effects of open-market operations on the distributions of assets and prices. It offers a theoretical framework to incorporate multiple asset holdings in a tractable heterogeneous-agent model. This model features competitive search, which produces distributions of money and bond holdings as well as price dispersion among submarkets. At a high enough bond supply, the equilibrium shows segmentation in the asset market; only households with good income shocks participate in the bond market. Segmentation in the asset market is generated endogenously without assuming any rigidities or frictions in the asset market. Numerical exercises show that when the asset market is segmented, the central bank can improve welfare by purchasing bonds and supplying money

Liquidity Effects of Central Banks' Asset Purchase Programs

I construct a model of the monetary economy, in which different assets provide liquidity services. Assets differ in terms of the liquidity services they provide, and money is the most liquid asset. The central bank can implement policies by changing the relative supply of money and other assets. I show that the central bank can change the overall liquidity and welfare of the economy by changing the relative supply of assets with different liquidity characteristics. A liquidity trap exists away from the Friedman rule that has a positive real interest rate; the central bank's asset purchase/sale programs may be ineffective in instances of low enough inflation rates. My model also enables me to study the welfare effects of a restriction on trade with government bonds

Applications of Medicinal Herbs and Essential Oils in Food Safety

In the last few years, more and more studies on the biological properties of essential oils (EOs) especially antimicrobial and antioxidant properties in vitro and food model have been published in all parts of the world. But so far no comprehensive reports of these studies have been reported in food model from Iran. The focus of this overview lies in the using of EOs from some indigenous medicinal plants of Iran (including Mentha longifolia, Cuminum cyminum, Teucrium polium, Pimpinella anisum and Allium ascalonicum) in probiotic dairy products (especially cheese, yoghurt and Aryan) in recent years. Recently, consumers have developed an ever-increasing interest in natural products as alternatives for artificial additives or pharmacologically relevant agents. Among them, EOs have gained great popularity in the food, cosmetic as well as pharmaceutical industries. Despite the reportedly strong antimicrobial activity of EOs against food-borne pathogens and spoilage microorganisms, their practical application as preservatives is currently limited owing to the undesirable flavour changes they cause in food products. Nonetheless, more studies are necessary to the applicability of various EOs on other food models in Iran and other countries

Possible income misstatement on mortgage loan applications: Evidence from the Canadian housing market

We construct a measure of possible income misstatement (PIM) for first-time homebuyers by quantifying the gap between growth in incomes reported on mortgage applications and growth in incomes reported on tax files from 2004 to 2014 in Canada. Using a two-stage least square framework to correct for the endogenous nature of house prices and PIM, we find robust evidence that part of the observed dispersion in PIM is caused by house price variation. This suggests borrowers have greater incentive to misstate income in high-priced markets. We report evidence that markets with a tendency for income misstatement also had higher default rates

Effect of Packaging Material on Color Properties of Catsup Tomato Sauce

Catsup and tomato sauce products currently are one of the most popular and commercially available table sauces particularly consumed by young people and families around the world in recent decades. In this study colorimetric properties of catsup sauce samples including L*, a* and b* values in different packaging materials including PP, PE, PET, Glass and Sachet have been investigated during and after 180 days storage time at 22̊ C (environmental temperature). Hunter Lab system has been used to evaluate the color values of sauce samples. According to obtained results of experimental measurements and sensory evaluations, PP and PE packaging materials affected significantly color properties of catsup sauce samples during and after the storage time that it because of interaction between packaging material and lycopene components in catsup sauce samples. Finally, According to consumer prefers to darker tomato and catsup sauce products, PP and PE are not suitable for packaging of catsup sauce production

Lead concentration in the muscles of slaughtered buffalos in northwest regions of Iran

Background: The topic of food safety has become a major public health issue worldwide. Over recent decades, the growing concern for food safety has brought about greater research regarding the risks associated with the consumption of produce that has been contaminated by pesticides, heavy metals and/or toxins. Objective: The study was conducted to determine the concentration of Pb in the muscle of buffalos slaughtered in the northwest regions of Iran (Ardabil, Urmia and Tabriz cities). Methods: The present was a descriptive cross-sectional study in the northwest regions of Iran during 2013 to 2014. A total of 30 muscle samples from individual buffalos were analyzed for Pb concentrations using Atomic Absorption Spectrophotometer (ASS). Statistical analysis was performed using SPSS 17.0. All results were computed as mean standard deviation and subjected to one-way analysis of variance to establish whether the differences in Pb concentrations in meat samples from different cities were significant or not. The Statistical significance was determined at p<0.05. Results: The results showed that the mean concentration of Pb in muscle samples were measured 0.043±0.035 ppm. The highest Pb concentration (0.11 ppm) was detected in the buffalo muscle samples from Urmia city. In total, 25 muscle samples (80.33%) were contaminated with Pb and concentration of Pb in 3.33% of contaminated samples exceeded the permissible limits advised by the European Commission (EC) (0.1 ppm). Conclusion: We recommend identifying Pb sources in order to eliminate or control Pb contamination of food, and monitor environmental exposures and hazards to prevent lead poisoning

Management of Hospital Infection Control in Iran: A Need for Implementation of Multidisciplinary Approach

AbstractNosocomial, or hospital-acquired, infections are considered the most common complications affecting hospitalized patients. According to results obtained from studies conducted in the Children Medical Center Hospital, a teaching children's hospital and a tertiary care referral unit in Tehran, Iran, improvements in infection control practices in our hospital seem necessary. The aim of this study was to identify risk management and review potential hospital hazards that may pose a threat to the health as well as safety and welfare of patients in an Iranian referral hospital. Barriers to compliance and poor design of facilities, impractical guidelines and policies, lack of a framework for risk management, failure to apply behavioral-change theory, and insufficient obligation and enforcement by infection control personnel highlight the need of management systems in infection control in our hospital. In addition, surveillance and early reporting of infections, evaluation of risk-based interventions, and production of evidence-based guidelines in our country are recommended

Data Driven Control of Vagus Nerve Stimulation for the Cardiovascular System: An in Silico Computational Study

Vagus nerve stimulation is an emerging therapy that seeks to offset pathological conditions by electrically stimulating the vagus nerve through cuff electrodes, where an electrical pulse is defined by several parameters such as pulse amplitude, pulse width, and pulse frequency. Currently, vagus nerve stimulation is under investigation for the treatment of heart failure, cardiac arrhythmia and hypertension. Through several clinical trials that sought to assess vagus nerve stimulation for the treatment of heart failure, stimulation parameters were determined heuristically and the results were inconclusive, which has led to the suggestion of using a closed-loop approach to optimize the stimulation parameters. A recent investigation has demonstrated highly specific control of cardiovascular physiology by selectively activating different fibers in the vagus nerve. When multiple locations and multiple stimulation parameters are considered for optimization, the design of closed-loop control becomes considerably more challenging. To address this challenge, we investigated a data-driven control scheme for both modeling and controlling the rat cardiovascular system. Using an existing in silico physiological model of a rat heart to generate synthetic input-output data, we trained a long short-term memory network (LSTM) to map the effect of stimulation on the heart rate and blood pressure. The trained LSTM was utilized in a model predictive control framework to optimize the vagus nerve stimulation parameters for set point tracking of the heart rate and the blood pressure in closed-loop simulations. Additionally, we altered the underlying in silico physiological model to consider intra-patient variability, and diseased dynamics from increased sympathetic tone in designing closed-loop VNS strategies. Throughout the different simulation scenarios, we leveraged the design of the controller to demonstrate alternative clinical objectives. Our results show that the controller can optimize stimulation parameters to achieve set-point tracking with nominal offset while remaining computationally efficient. Furthermore, we show a controller formulation that compensates for mismatch due to intra-patient variabilty, and diseased dynamics. This study demonstrates the first application and a proof-of-concept for using a purely data-driven approach for the optimization of vagus nerve stimulation parameters in closed-loop control of the cardiovascular system