Volume Elasticity Research Articles

Regulated Revenues and Hospital Behavior: Evidence from a Medicare Overhaul

Abstract We study a 2008 policy reform in which Medicare revised its hospital payment system to better reflect patients’ severity of illness. We construct a simulated instrument that predicts a hospital’s policy-induced change in reimbursement using pre-reform patients and postreform rules. The reform led to large persistent changes in Medicare payment rates across hospitals. Hospitals that faced larger gains in Medicare reimbursement increased the volume of Medicare patients they treated. The estimates imply a volume elasticity of 1.2. To accommodate greater volume, hospitals increased nurse employment, but also lowered length of stay.

Carbon nanotube reinforced FeMoO4 nanorods as a high-performance anode for sodium-ion batteries

Iron molybdate (FeMoO4) nanostructures show great promise as a superior anode for sodium-ion batteries. However, its use in practical application is hampered by its poor electronic conductivity, large volume changes and sluggish reaction kinetics. Herein, we have developed an interconnected network of multiwall carbon nanotube (CNT) and FeMoO4 (FMO) by a simple one-step hydrothermal method. As well as providing efficient channels for charge transfer and diffusion, highly conductive CNTs also have a degree of volume elasticity and excellent electrical conductivity to ensure migration of sodium ions, enabling both fast kinetics and long-term stability. As a result, the FMO@CNT anode delivers a high reversible capacity of 485 mA h g−1 at 0.05 A/g and very long cycling stability with a capacity of 75 mA h g−1 after 1000 cycles at 1 A/g. Furthermore, by combining the ex-situ X-ray diffraction, ex situ X-ray photoelectron spectroscopy and cyclic voltammetry results, sodium ion storage mechanism of the FMO@CNT electrode obeys a conversion mechanism. The results of this work provide a better understanding on the sodium ion storage mechanism of binary metal oxides.

Effects of the intramolecular structural change on the superconducting phase of the TMTTF systems

The tetramethyltetrathiafulvalene (TMTTF) system is one of the key materials to reveal mechanisms for unconventional superconductivity which is driven by electronic correlation. Recent experimental studies show that only the SbF6 salt, which exhibit the strongest charge order among the PF6 and AsF6 and SbF6 salts have anomalously high superconducting phase transition pressure for the insulating-superconducting phase and superconducting-metallic phase transitions. To investigate the relationship between the superconductivity and the strength of the charge order of these salts, we constructed an extended Hubbard model with the periodic boundary condition that takes into account the site-deformation potential driven by the intramolecular structural change which causes the nonuniform charge order. The superconductivity was examined by the Drude weight and the charge gap obtained by exact diagonalization. It was found that site-deformation potentials driven by the intramolecular conformational change, even small changes, move the insulator-superconductor transition point to higher pressure, i.e. too large transfer integrals. Without the site-deformation potentials, the transfer integral at the transition point is too small as compared with those values deduced from the first-principles calculations at the structures under atmospheric pressure and it is difficult to reproduce the transition.

Can we detect regional differences in econometric analyses of the Norwegian timber supply?

Forestry and forest industries are important for regional income and employment in Norway as well as in most North European countries, but few studies exist about factors affecting the timber supply at regional level. The main objective of this study is to estimate aggregated regional timber supply elasticities for six regions in Norway. Thereby we also test for regional differences, focusing on wood prices, standing stock volume and interest rate as explanatory variables. We have used three different statistical models (fixed and random effects panel models and first difference models) on regional data from the Norwegian forest inventory on standing volume and official statistics on harvested volumes, interest rate and prices of sawlogs and pulpwood for the period 1996–2016. Statistically significant different price elasticities are found in 12 out of total 15 pairs of regions. The price elasticity was lower and the volume elasticity higher in the western region compared to the other regions. The first difference models are best with respect to specification tests. The use of region specific price elasticities gives slightly better fit for the panel data models than using a uniform price parameter. The results show that the econometric specification influence the parameter values, and it is thus complicated to directly compare results in different timber supply studies. Regional differences in timber supply are important to consider.

To pool or not to pool? Security design in OTC markets

We study security issuers’ decisions on whether to pool assets when facing counterparties endowed with market power, as is common in over-the-counter markets. Our analysis reveals how buyers’ market power may render the pooling of assets suboptimal — both privately and socially — in particular, when the potential gains from trade are large. Pooling assets then reduces the elasticity of trade volume in the relevant part of the payoff distribution, exacerbating the inefficient rationing associated with the exercise of buyers’ market power. Our analysis provides insight on the determinants of asset-backed securities issuance, including regulatory reforms affecting financial institutions’ liquidity.

Porous carbon assisted carbon nanotubes supporting Fe3O4 nanoparticles for improved lithium storage

Herein, to efficiently improve the lithium storage of Fe3O4 nanoparticles, a distinctive porous carbon (PC) assisted carbon nanotubes (CNTs) supporting architecture has been designed and fabricated successfully. The Fe3O4 nanoparticles are deposited on the surface of CNTs and then covered by an extra PC. In such a designed architecture, highly conductive and robust CNTs can not only improve the conductivity but also boost the structure of the as-fabricated Fe3O4-based composite (CNTs@Fe3O4@PC). In particular, the foam-like PC has a certain level of volume elasticity and open tunnel-like structure to better anchor the Fe3O4 nanoparticles on the surface of CNTs and facilitate the transfer of electrons and ions, therefore guaranteeing the fast kinetics and long-term stability. The results show that the capacitive contribution is predominant in lithium storage of the CNTs@Fe3O4@PC electrode. Consequently, the as-fabricated CNTs@Fe3O4@PC shows high capacity, good rate capability, and long life, displaying 766 and 572 mAh g-1 after 400 and 700 cycles at 200 and even 1000 mA g-1, respectively. Thus outstanding performance makes the CNTs@Fe3O4@PC have great potential to be advanced lithium-ion battery anode materials. Furthermore, this strategy can be extended to other nanostructured metal oxide anodes, such as CoO, SnO2, and Bi2O3 nanomaterials.

Carbon-Reinforced Nb2CTx MXene/MoS2 Nanosheets as a Superior Rate and High-Capacity Anode for Sodium-Ion Batteries.

Sodium-ion batteries operating at room temperature have emerged as a generation of energy storage devices to replace lithium-ion batteries; however, they are limited by a lack of anode materials with both an adequate lifespan and excellent rate capability. To address this issue, we developed Nb2CTx MXene-framework MoS2 nanosheets coated with carbon (Nb2CTx@MoS2@C) and constructed a robust three-dimensional cross-linked structure. In such a design, highly conductive Nb2CTx MXene nanosheets prevent the restacking of MoS2 sheets and provide efficient channels for charge transfer and diffusion. Additionally, the hierarchical carbon coating has a certain level of volume elasticity and excellent electrical conductivity to guarantee the intercalation of sodium ions, facilitating both fast kinetics and long-term stability. As a result, the Nb2CTx@MoS2@C anode delivers an ultrahigh reversible capacity of 530 mA h g-1 at 0.1 A g-1 after 200 cycles and very long cycling stability with a capacity of 403 mA h g-1 and only 0.01% degradation per cycle for 2000 cycles at 1.0 A g-1. Moreover, this anode has an outstanding capacity retention rate of approximately 88.4% from 0.1 to 1 A g-1 in regard to rate performance. Most importantly, the Nb2CTx@MoS2@C anode can realize a quick charge and discharge at current densities of 20 or even 40 A g-1 with capacities of 340 and 260 mAh g-1, respectively, which will increase the number of practical applications for sodium-ion batteries.

Regulated Revenues and Hospital Behavior: Evidence from a Medicare Overhaul

We study a 2008 policy reform in which Medicare revised its hospital payment system to better reflect patients’ severity of illness. We construct a simulated instrument that predicts a hospital’s policy-induced change in reimbursement using pre-reform patients and post-reform rules. The reform led to large persistent changes in Medicare payment rates across hospitals. Hospitals that faced larger gains in Medicare reimbursement increased the volume of Medicare patients they treated. The estimates imply a volume elasticity of approximately unity. To accommodate greater volume, hospitals increased nurse employment, but also lowered length of stay, with ambiguous effects on quality.

Abstract 13565: Superoxide Dismutase-loaded Nanoparticles Attenuate Myocardial Ischemia-Reperfusion Injury and Protect Against Chronic Adverse Ventricular Remodeling

Introduction: Revascularization relieves myocardial ischemia but induces additional reperfusion injury by oxidative stress. Superoxide dismutase (SOD) is a potent antioxidant with preclinical promise in reducing reperfusion injury but is not well retained within the myocardium. Hypothesis: Use of SOD-encapsulated nanoparticles (NP-SOD) will improve SOD retention and preserve cardiac function in a rat model of myocardial ischemia-reperfusion (I/R) injury. Methods: Ischemia was maintained for 60 minutes via occlusion of the left anterior descending artery (LAD). Immediately prior to reperfusion, intramyocardial injections of NP-SOD, free SOD or phosphate buffered saline (PBS) were administered along the border of ischemic myocardium. Acute injury was assessed 3 hours post-reperfusion (n=8 per group), and chronic injury at 4 weeks (n=12). Hemodynamics were measured by echocardiography and pressure-volume loops. Acute and chronic injury were examined histologically. Protein isolates at 3 hours measured mediators of cell-death. Intramyocardial enzyme retention analysis was performed by injecting NP or free fluorescent-tagged SOD and explanting hearts for imaging at 0, 24 and 72 hours (n=4 per group). Results: Intramyocardial SOD retention was 25% greater in NP-SOD than free SOD at 24 hours (p<0.01) and 78% greater at 72 hours (p<0.01). NP-SOD exhibited improved ventricular function by ejection fraction at 4 weeks (64%) compared to free SOD (51%; p<0.01) and PBS (43%; p<0.01). Cardiac output, stroke volume and end-systolic elastance were greater in NP-SOD. Histology at 28 days demonstrated 54% less macroscopic fibrosis and 85% less microscopic collagen deposition in NP-SOD compared to PBS, and 33/79% compared to free SOD (all p<0.05). Quantifying RIPK3 protein levels in ‘at risk’ myocardium at 3 hours demonstrated 2.5-fold reduced upstream necrosome activation. Conclusions: NP-SOD provides prolonged enzyme retention within the myocardium. Intramyocardial NP-SOD administration prior to reperfusion attenuates acute myocardial injury and protects against chronic adverse ventricular remodeling. SOD acts by downregulating necrosis. These findings suggest potential for NP-SOD based therapy in mitigating myocardial I/R injury.

The Renminbi as a Trading Currency: Evidence from Selected Countries Participating in the Belt and Road Initiative

AbstractThis paper investigates the effects of the renminbi (RMB) exchange rate on trade prices and volumes in selected Belt and Road Initiative (BRI) countries in comparison with the effects of the US dollar. The stylized facts show that the RMB is underused in bilateral trade with selected BRI countries where intermediate goods dominate. By estimating the level of exchange rate pass‐through and trade volume elasticity, we find that the RMB is significantly correlated with the volume of imports in the sample countries, predicted by the producer currency pricing (PCP) paradigm. We also regroup intermediate and final goods between China and the BRI countries. The evidence shows that dollar fluctuation affects export volumes, reflecting the role of the US as a final goods destination, whereas the RMB exerts a significant impact on the volume of intermediate goods imported from China to the sample countries due to China's important position in global value chains.

Loan guarantees and credit supply

The efficiency of federal lending guarantees depends on whether guarantees increase lending supply or simply act as a subsidy to lenders. We use notches in the guarantee rate schedule for Small Business Administration (SBA) loans to estimate the elasticity of bank lending volume to loan guarantees. We show significant bunching in the loan distribution on the side of the size threshold that carries a more generous loan guarantee. The excess mass implies that increasing guarantee generosity by one percentage point of loan principal would increase per-loan lending volume by $19,000. Excess mass increases in periods with guarantee generosity, and placebo results indicate that the effect disappears when the guarantee notch is eliminated.

Impactos do amido resistente e da enzima transglutaminase nas características tecnológicas de espaguete

O uso de amido resistente em novos produtos vem aumentando devido aos benefícios à saúde associado ao consumo de fibras. Entretanto, sua utilização em produtos, como massas alimentícias, é limitada por enfraquecer a rede de glúten. Uma possibilidade para solucionar este problema é a adição da enzima transglutaminase. O objetivo deste estudo foi avaliar a influência da adição de amido resistente (AR) e de transglutaminase (TG) nas características de cozimento, textura, cor e na solubilidade de proteínas de espaguete, através de um delineamento composto central rotacional de duas variáveis independentes (x1 = AR, 0 a 20 %; x2 = TG, 0,2 a 1,0 %). As principais variáveis dependentes estudadas foram: amido resistente, cor instrumental, características de cozimento e de textura e solubilidade de proteínas. Através da Metodologia de Superfície de Resposta analisou-se os resultados que demonstraram que AR e TG apresentaram influência na qualidade dos produtos, sendo estatisticamente significativas (p<0,10) para cor, tempo ótimo de cozimento, aumento de peso, aumento de volume, elasticidade e teor de amido resistente. A luminosidade (L*) foi maior com o aumento de AR e TG. Maiores teores de AR diminuem o tempo de cozimento e a elasticidade. Dentre as variáveis independentes, AR apresentou maior efeito sobre as variáveis dependentes estudadas. O ponto otimizado (0,70 de desejabilidade) necessita do uso de 18,65 % de amido resistente, resultando em um espaguete com apelo de fonte de fibra alimentar, pois contêm mais de 2,5 g de fibra alimentar, por porção, no produto pronto para o consumo.

Modeling Tourism Demand of Iran and Selected Countries (Application of ARDL Method)

Today, the tourism industry is one of the most influential industries in the economies of societies, especially in countries seeking a substitute for the export of single-product resources. Having a young population seeking job and great tourism attractions in the region and the world, Iran is in a good place in terms of tourist attraction. Despite the favorable conditions, its status is not favorable in comparison to similar countries. Accordingly, the present study aims to analyze the main determinants of international tourism demand of Iran by examining the current and desirable situation during the period of 1991-2018. Also, it aims to estimate the function of tourism demand in Iran in this time period using the ARDL method. The results of the present study show that the variables of national income of the origin countries (tourist sender), the volume of trade between Iran and other countries, security, as well as the ratio of consumer price index in Iran to consumer price index in origin countries are the most important determinant indicators of Iran’s international tourism demand in the short and long term, respectively. In addition, the negative elasticity of security and price index and the positive elasticity of national income and trade volume, as well as the positive coefficient of the number of tourists in the previous period indicate the effect of these indicators in this study. Keywords: Tourism demand, ARDL, demand determinants.

Autoaugmentation mastopexy using the double-flap technique

Breast drooping usually results from two concomitant factors: breast parenchymal involution, which leads to volume loss, altogether with a progressive laxity of the skin envelope which becomes inelastic and flabby (means so loose). The authors propose a double-flap technique which includes transposition of inferiorly based dermoglandular tissue underneath a superiorly based flap to achieve a central projection and upper fullness altogether with raising the inframammary crease. From May 2016 to November 2018, 25 patients underwent a double-flap autoaugmentation mammoplasty performed by the authors. Ages ranged from 25 to 45 years. All patients were nonsmokers and had body mass indexes (BMI) of less than 30. The mean follow-up period was 18 months All cases have had grade III breast ptosis with a broad-base, flappy breasts with deficient central projection. All patients aimed at having an augmented, elevated breast without insertion of a silicon implant. A total of 23 cases showed a significant improvement in breast contour and central projection, with overall satisfaction to both patient and surgeon. Two cases progressed to an implant augmentation subsequent to the mastopexy. One patient had postoperative seroma that were managed with frequent aspirations. The nipple areola complex (NAC) wounds passed smoothly in all cases without any complications regarding the vascularity or wound infection. The double-flap autoaugmentation mastopexy is a method of breast reshaping that adopts a concept of glandular rearrangement. In properly selected patients with adequate breast volume and moderate skin elasticity, with mild to moderate ptosis, who refuse a prosthetic implant insertion, this procedure safely and adequately restores the youthful conical breast appearance. Level of evidence: Level IV, therapeutic study.

The Impact of PM10 Levels on Pedestrian Volume: Findings from Streets in Seoul, South Korea.

Although many studies have revealed that both air quality and walking activity are dominant contributors to public health, little is known about the relationship between them. Moreover, previous studies on this subject have given little consideration to the day-to-day atmospheric conditions and floating populations of surrounding areas even though most pedestrian count surveys are not conducted on a single day. Against this backdrop, using the 2015 Pedestrian Volume Survey data and quasi-real-time weather, air quality, and transit ridership data in Seoul, this study investigates the relationship between particulate matter (PM)10 and pedestrian street volumes empirically. The regression results suggest that PM10 concentration determines people’s intention to walk and affects the volume of street-level pedestrians. The three regression models, which adopted different spatial aggregation units of air quality, demonstrated that PM10 elasticity of pedestrian volume is the largest in the borough-level (the smallest spatial unit of air quality alert) model. This means that people react to the most accurate information they can access, implying that air quality information should be provided in smaller spatial units for public health. Thus, strengthening air quality warning standards of PM is an effective measure for enhancing public health.

The price elasticity of parking: A meta-analysis

The effect of parking fees on parking demand has been investigated in many different contexts, applying a wide variety of study designs. Research that brings together the knowledge derived in these studies systematically, however, is scarce. We conduct a meta-analysis of parking price elasticities based on 50 studies. Using seemingly unrelated regression models we account for the interdependence between the price elasticity of occupancy (EPO), dwell time (EPD), and volume (EPV). We show that estimates of parking elasticities based on stated preference (SP) data lead to different managerial and policy insights than estimates based on revealed preference (RP) data. Given a large amount of reported and unreported variation between the existing studies on parking price elasticities, we provide concrete recommendations for future studies that should warrant a higher degree of comparability and coherence in research design, conduction, and reporting.

Loan Guarantees and Credit Supply

The efficiency of federal lending guarantees depends on whether guarantees increase lending supply, or simply act as a subsidy to lenders. We use notches in the guarantee rate schedule for loans backed by the Small Business Administration to estimate the elasticity of bank lending volume to loan guarantees. We document significant bunching in the loan distribution on the side of the size threshold that carries a more generous loan guarantee. The excess mass implies that increasing guarantee generosity by 1 percentage point of loan principal would increase per-loan lending volume by $19,000. Bank lending is responsive both in the crosssection and in the time-series - excess mass increases with the guarantee discontinuity, and placebo results indicate that the effect disappears when the guarantee notch is eliminated.

Laws of volume elasticity in physical processes of the effect of T, P, H parameters on the lattice modifications, phase transitions, conductivity and magnetism

Analysis of the experimental results allows to single out the law of bulk elasticity that implies that the structural binding energy is formed by physical and chemical methods and transformed into elastic stresses that control lattice changes, formation of phase transitions, resistivity and magnetism in the course of physical processes under the effect of parameters. The laws of volume thermo-, baro-and magnetoelasticity are the determining factors in lattice modifications in the structure sites together with the composition variation.

The Effect of Retail Distribution on Sales of Alcoholic Beverages

We use monthly sales of all wines, beer, and spirits sold between 2006 and 2011 by Sweden’s retail monopoly on alcohol to estimate the causal effect of retail distribution on market share by volume at the product level. Products are defined at the level of the stock-keeping unit. Two institutional features are key to identifying the causal effect: First, the monopolist uses four levels of retail distribution; a change in retail distribution is therefore associated with a discrete shift in the number of stores that carry a product in a given month. Second, the retailer is legally bound and monitored by the European Union to ensure that it acts in a non-discriminatory manner with all its suppliers. These features allow us to rule out many possible confounding factors in estimating the effect of distribution on sales volume. We find large and statistically significant effects from changes in retail distribution on market share by volume across all levels of retail distribution. The associated volume elasticity of retail distribution is convex; the wider the retail distribution the greater the marginal volume increase from further widening. In this market, wider distribution means reaching stores with successively smaller assortment. Our results indicate that the smaller assortment in smaller stores, coupled with a low resistance to compromise, is the main reason for the convex pattern. In other words, convexity appears to be generated by products achieving “a larger share of a smaller pie” as retail distribution expands. Data are available at https://doi.org/10.1287/mksc.2017.1038 .

Evaluation of Antivascular Combretastatin A4 P Efficacy Using Supersonic Shear Imaging Technique of Ectopic Colon Carcinoma CT26

A recent ultrasound imaging technique—shear wave elastography—showed its ability to image and quantify the mechanical properties of biological tissues, such as prostate or liver tissues. In the present study this technique was used to evaluate the relationship among tumor growth, stiffness and reduction of treatment with combretastatin (CA4 P) in allografted colon tumor CT26 in mice. During 12 d, CT26 tumor growth (n = 52) was imaged by ultrasound, and shear modulus was quantified, showing a good correlation between tumor volume and stiffness (r = 0.59). The treatment was initiated at d 12 and monitored every d during 4 d. Following the treatment, the tumor volume had decreased, while the elasticity of the tumor volume remained steady throughout the treatment. After segmentation using the shear modulus map, a detailed analysis showed a decrease in the stiffness after treatment. This reduction in the mechanical properties was shown to correlate with tissue reorganization, particularly, fibrosis and necrosis, assessed by histology.