bluuebunny/crossref_metadata_2025 huggingface dataset:
The Value and Ownership of Intangible Capital
Authors: Eisfeldt Andrea L. , Papanikolaou Dimitris
Published: May 2014

Intangible capital which relies on essential human inputs, or 'organization capital,' presents a unique challenge for measurement. Organization capital cannot be fully owned by firms' financiers, because it is partly embodied in key labor inputs. Instead, cash flows must be shared with key talent and thus neither book nor market values will fully capture its value. Measurement of organization capital requires a model featuring these unique property rights. We use accounting data along with a simple example of such a model to measure the fraction of the US capital stock which is missing from book and market values.
Estimation of an Education Production Function under Random Assignment with Selection
Authors: Choi Eleanor Jawon , Moon Hyungsik Roger , Ridder Geert
Published: May 2014

This paper estimates an education production function using data on the College Scholastic Ability Test score and high school characteristics from Seoul, Korea, where, on entering high school, students are randomly assigned to schools within each school district. We derive a school production function by aggregating the individuals' potential outcomes under the random assignment and no cohort effect assumption. We find that the school production function coefficients differ between districts and that the single-sex school effect estimate is much larger than that found in previous studies.
Gender and Business Outcomes of Black and Hispanic New Entrepreneurs in the United States
Authors: Mora Marie T. , Dávila Alberto
Published: May 2014

In light of the growing numbers of women of color in the entrepreneurial sector in the United States, employing public-use microdata from the 2007 Survey of Business Owners, this study finds that new firms owned by black and Hispanic women were more likely to cease operations than those owned by their male counterparts or by non-Hispanic whites, even when controlling for other owner- and firm-level characteristics and labor market conditions. These differences occurred despite the existence of public programs designed to help female and minority entrepreneurs, raising the question of efficiency of the current policy infrastructure in the United States.
Entrepreneurial Innovation: Killer Apps in the iPhone Ecosystem
Authors: Yin Pai-Ling , Davis Jason P. , Muzyrya Yulia
Published: May 2014

The mobile applications (apps) industry has exhibited rapid entry and growth in the midst of a recession. Using unique data from the iPhone application ecosystem, we examine how the development of 'killer apps' (apps appearing in the top grossing rank) varies by market and app characteristics. We find that previous app experience and no updating increase the likelihood of becoming a killer game app, while more updates increase the likelihood of becoming a non-game killer app. Development opportunities, level of competition, and demand preferences are possible drivers of the opposing innovation process results in game and non-game markets.
Learning From the Doers: Developing Country Lessons for Advanced Economy Growth
Authors: Chari Anusha , Henry Peter Blair
Published: May 2014

From 1980 to 1992, emerging and developing countries grew by 3.4 percent per year. Their annual rate of growth increased to 5.4 percent between 1993 and 2012. No such increase occurred for advanced nations, whose average growth from 1980 to 2012 was roughly constant (excluding the impact of the 2008-2009 Recession). Developing nations turned themselves around by embracing discipline-sustained commitment to a pragmatic and flexible growth strategy. Three illustrations of discipline through the lens of trade, fiscal, and debt reforms in the developing world offer relevant, practical lessons for recovery in advanced economies and continued catch-up growth in developing nations.
Inflation Persistence, the NAIRU, and the Great Recession
Authors: Watson Mark W.
Published: May 2014

The rate of inflation fell far less over the period 2007-2013 than in the period 1979-1985 despite similar large increases in the unemployment rate. This paper asks why. Possible explanations include a change in the persistence of inflation, changes in NAIRU, and other shocks. A change in the persistence of inflation, with inflation more anchored in the period 2007-2013 than in the period 1979-1985, is found to be important. The level and change in the NAIRU cannot be precisely estimated, but the data suggest an increase of nearly 1 percentage point since 2007.
Missing Gains from Trade?
Authors: Melitz Marc J. , Redding Stephen J.
Published: May 2014

In a class of trade models which satisfy a constant elasticity gravity equation, the welfare gains from trade can be computed using the open economy domestic trade share and a constant trade elasticity. The measured welfare gains from trade from this quantitative approach are typically relatively modest. In this paper, we suggest a channel for welfare gains that this quantitative approach typically abstracts from: trade-induced changes in domestic productivity. Using a model of sequential production, in which trade induces a reorganization of production that raises domestic productivity, we show that the welfare gains from trade can become arbitrarily large.
Disability Insurance and Health Insurance Reform: Evidence from Massachusetts
Authors: Maestas Nicole , Mullen Kathleen J. , Strand Alexander
Published: May 2014

As health insurance becomes available outside of the employment relationship as a result of the Affordable Care Act (ACA), the cost of applying for Social Security Disability Insurance (SSDI)—potentially going without health insurance coverage during a waiting period totaling 29 months from disability onset —will decline for many people with employer-sponsored health insurance. At the same time, the value of SSDI and Supplemental Security Income (SSI) participation will decline for individuals who otherwise lacked access to health insurance. We study the 2006 Massachusetts health insurance reform to estimate the potential effects of the ACA on SSDI and SSI applications.
The Natural Rate of Interest and Its Usefulness for Monetary Policy
Authors: Barsky Robert , Justiniano Alejandro , Melosi Leonardo
Published: May 2014

We estimate a state-of-the-art DSGE model to study the natural rate of interest in the United States over the last 20 years. The natural rate is highly procyclical, and fell substantially below zero in each of the last three recessions. Although the drop was of comparable magnitude across the three recessions, the decline was considerably more persistent in the Great Recession. We discuss the usefulness and limitations, particularly due to the zero lower bound, of the natural rate for the conduct of monetary policy.
Are Female Supervisors More Female-Friendly?
Authors: Bednar Steven , Gicheva Dora
Published: May 2014

We introduce the idea that easily inferable demographic characteristics such as gender may not be sufficient to define type in the supervisor-employee mentoring relationship. We use longitudinal data on athletic directors at NCAA Division I programs to identify through observed mobility the propensity of top-level administrators to hire and retain female head coaches, above and beyond an organization's culture. We show that supervisor gender appears to be unrelated to female friendliness in this setting. Overall, our findings indicate that more focus should be placed on the more complex manager type defined by attitudes in addition to attributes.
Race and Marriage in the Labor Market: A Discrimination Correspondence Study in a Developing Country
Authors: Arceo-Gomez Eva O. , Campos-Vazquez Raymundo M.
Published: May 2014

In Mexico, as in most Latin American countries with indigenous populations, it is commonly believed that European phenotypes are preferred to mestizo or indigenous phenotypes. However, it is hard to test for such racial biases in the labor market using official statistics since race can only be inferred from native language. The experiment consisted on sending fictitious curriculums responding to job advertisements with randomized information of the applicants. The resumes included photographs representing three distinct phenotypes: Caucasian, mestizo, and indigenous. We find that indigenous looking females are discriminated against, but the effect is not present for males.
Ability-Tracking, Instructional Time, and Better Pedagogy: The Effect of Double-Dose Algebra on Student Achievement
Authors: Cortes Kalena E. , Goodman Joshua S.
Published: May 2014

This paper provides new evidence on tracking by studying an innovative curriculum implemented by Chicago Public Schools (CPS). In 2003, CPS enacted a double-dose algebra policy requiring 9th grade students with 8th grade math scores below the national median to take two periods of algebra instead of one. This policy led schools to sort students into algebra classes by math ability, so that tracking increased in all algebra classes. We show that double-dosed students are exposed to a much lower-skilled group of peers in their algebra classes but nonetheless benefit substantially from the additional instructional time and improved pedagogy.
Using School Choice Lotteries to Test Measures of School Effectiveness
Authors: Deming David J.
Published: May 2014

Value-added models (VAMs) are increasingly used to measure school effectiveness. Yet, random variation in school attendance is necessary to test the validity of VAMs and to guide the selection of models for measuring causal effects of schools. In this paper, I use random assignment from a public school choice lottery to test the predictive power of VAM specifications. In VAMs with minimal controls and two or more years of prior data, I fail to reject the hypothesis that school effects are unbiased. Overall, many commonly used VAMs are accurate predictors of student achievement gains.
Mechanism Design in Large Games: Incentives and Privacy
Authors: Kearns Michael , Pai Mallesh M. , Roth Aaron , Ullman Jonathan
Published: May 2014

We study the design of mechanisms satisfying a novel desideratum: privacy. This requires the mechanism not reveal 'much' about any agent's type to other agents. We propose the notion of joint differential privacy: a variant of differential privacy used in the privacy literature. We show by construction that mechanisms satisfying our desiderata exist when there are a large number of players, and any player's action affects any other's payoff by at most a small amount. Our results imply that in large economies, privacy concerns of agents can be accommodated at no additional 'cost' to standard incentive concerns.
The Future of US Economic Growth
Authors: Fernald John G. , Jones Charles I.
Published: May 2014

Modern growth theory suggests that more than three-quarters of growth since 1950 reflects rising educational attainment and research intensity. As these transition dynamics fade, US economic growth is likely to slow at some point. However, the rise of China, India, and other emerging economies may allow another few decades of rapid growth in world researchers. Finally, and more speculatively, the shape of the idea production function introduces a fundamental uncertainty into the future of growth. For example, the possibility that artificial intelligence will allow machines to replace workers to some extent could lead to higher growth in the future.
The VCG Auction in Theory and Practice
Authors: Varian Hal R. , Harris Christopher
Published: May 2014

We describe two auction forms for search engine advertising and present two simple theoretical results concerning i) the estimation of click-through rates and ii) how to adjust the auctions for broad match search. We also describe some of the practical issues involved in implementing a VCG auction.
Market Design and the Evolution of the Combinatorial Clock Auction
Authors: Ausubel Lawrence M. , Baranov Oleg V.
Published: May 2014

The Combinatorial Clock Auction (CCA) is an important recent innovation in auction design which has been adopted for many spectrum auctions worldwide. Since its inception, the CCA has been in almost continual evolution. We begin by reviewing some important changes which have already occurred. Despite these enhancements, we observe that the performance of the CCA is still limited by weak activity rules, suboptimal price feedback, and a missing-bid problem. We then describe further evolutionary changes, including new activity rules, new approaches to pricing, and an integration of non-mutually-exclusive bids, which will help to address these issues.
Costly Persuasion
Authors: Gentzkow Matthew , Kamenica Emir
Published: May 2014

We study the design of informational environments in settings where generating information is costly. We assume that the cost of a signal is proportional to the expected reduction in uncertainty. We show that Kamenica & Gentzkow's (2011) concavification approach to characterizing optimal signals extends to these settings.
Interim Bayesian Persuasion: First Steps
Authors: Perez-Richet Eduardo
Published: May 2014

This paper makes a first attempt at building a theory of interim Bayesian persuasion. I work in a minimalist model where a low or high type sender seeks validation from a receiver who is willing to validate high types exclusively. After learning her type, the sender chooses a complete conditional information structure for the receiver from a possibly restricted feasible set. I suggest a solution to this game that takes into account the signaling potential of the sender's choice.
Stochastic Choice: An Optimizing Neuroeconomic Model
Authors: Woodford Michael
Published: May 2014

A model is proposed in which stochastic choice results from noise in cognitive processing rather than random variation in preferences. The mental process used to make a choice is nonetheless optimal, subject to a constraint on available information-processing capacity that is motivated by neurophysiological evidence. The optimal information-constrained model is found to offer a better fit to experimental data on choice frequencies and reaction times than either a purely mechanical process model of choice (the drift-diffusion model) or an optimizing model with fewer constraints on feasible choice processes (the rational inattention model).
Equalizing Superstars: The Internet and the Democratization of Education
Authors: Acemoglu Daron , Laibson David , List John A.
Published: May 2014

Internet-based educational resources are proliferating rapidly. One concern associated with these (potentially transformative) technological changes is that they will be disequalizing—as many technologies of the last several decades have been—creating superstar teachers and a winner-take-all education system. These important concerns notwithstanding, we contend that a major impact of web-based educational technologies will be the democratization of education: educational resources will be more equally distributed, and lower-skilled teachers will benefit. At the root of our results is the observation that skilled lecturers can only exploit their comparative advantage if other teachers complement those lectures with face-to-face instruction. This complementarity will increase the quantity and quality of face-to-face teaching services, potentially increasing the marginal product and wages of lower-skill teachers.
Fat Tails and the Social Cost of Carbon
Authors: Weitzman Martin L.
Published: May 2014

At high enough greenhouse gas concentrations, climate change might conceivably cause catastrophic damages with small but non-negligible probabilities. If the bad tail of climate damages is sufficiently fat, and if the coefficient of relative risk aversion is greater than one, the catastrophe-reducing insurance aspect of mitigation investments could in theory have a strong influence on raising the social cost of carbon. In this paper I exposit the influence of fat tails on climate change economics in a simple stark formulation focused on the social cost of carbon. I then attempt to place the basic underlying issues within a balanced perspective.
The Costs and Consequences of Clean Air Act Regulation of CO2from Power Plants
Authors: Burtraw Dallas , Linn Josh , Palmer Karen , Paul Anthony
Published: May 2014

US climate policy is unfolding under the Clean Air Act. Mobile source and construction permitting regulations are in place. Most important, EPA and the states will determine the form and stringency of the regulations for power plants. Various approaches would create an implicit price on emitting greenhouse gases and create valuable assets that would be distributed differently among electricity producers, consumers, and the government. We compare a tradable performance standard with several cap-and-trade policies. Distributing asset values to fossil-fueled producers and consumers has small effects on average electricity prices but imposes greater social cost than a revenue-raising policy.
Why Has US Policy Uncertainty Risen Since 1960?
Authors: Baker Scott R. , Bloom Nicholas , Canes-Wrone Brandice , Davis Steven J. , Rodden Jonathan
Published: May 2014

We consider two classes of explanations for the rise in policy-related economic uncertainty in the United States since 1960. The first stresses growth in government spending, taxes, and regulation. A second stresses increased political polarization and its implications for the policymaking process and policy choices.
Tax Policy Issues in Designing a Carbon Tax
Authors: Marron Donald B. , Toder Eric J.
Published: May 2014

A carbon tax is a promising tool for discouraging the greenhouse gas emissions that cause climate change. In principle, a well-designed tax could reduce the risk of climate change, minimize the cost of emissions reductions, encourage innovation in low-carbon technologies, and raise new public revenue. But designing a real-world carbon tax poses significant challenges. We analyze those challenges from a public finance perspective, emphasizing three tax policy design issues: setting the tax rate, collecting the tax, and using the resulting revenue. The benefits of a carbon tax will depend on how policymakers address those issues.
How Effective are US Renewable Energy Subsidies in Cutting Greenhouse Gases?
Authors: Murray Brian C. , Cropper Maureen L. , de la Chesnaye Francisco C. , Reilly John M.
Published: May 2014

The federal tax code provides preferential treatment for the production and use of renewable energy. We report estimates of the subsidies' effects on greenhouse gases (GHG) emissions developed in a recent National Research Council (NRC) Report. Due to lack of estimates of the impact of tax provisions on GHG emissions, new modeling studies were commissioned. The studies found, at best, a small impact of subsidies in reducing GHG emissions; in some cases, emissions increased. The NRC report also identified the need to capture the complex interactions among subsidies, pre-existing regulations, and commodity markets.
Why Is Housing Finance Still Stuck in Such a Primitive Stage?
Authors: Shiller Robert J.
Published: May 2014

The institutions for financing owner-occupied housing have not progressed as they should, and the financial innovation that has followed the financial crisis of 2007-2009 has not been focused on improving the risk management of individual homeowners. This paper lists a number of barriers to housing finance innovation, and in light of these barriers, the problems of some major innovations of the past and future: self-amortizing mortgages, price-level adjusted mortgages (PLAMs), shared appreciation mortgages (SAMs), housing partnerships, and continuous workout mortgages (CWMs).
Renegotiation Policies in Sovereign Defaults
Authors: Arellano Cristina , Bai Yan
Published: May 2014

This paper studies an optimal renegotiation protocol designed by a benevolent planner when two countries renegotiate with the same lender. The solution calls for recoveries that induce each country to default or repay, trading off the deadweight costs and the redistribution benefits of default independently of the other country. This outcome contrasts with a decentralized bargaining solution where default in one country increases the likelihood of default in the second country because recoveries are lower when both countries renegotiate. The paper suggests that policies geared at designing renegotiation processes that treat countries in isolation can prevent contagion of debt crises.
Effect of Added Wheat Flour on Retardation of Retrogradation in Garaetteok
Authors: Kim Hee-Sun , Kim Kyung-Mi , Han Gwi-Jung , Lee Hyeon-Gyu , Kim Myung-Hwan
Published: May 2014

This study was performed to analyze the degree in the reduction of retrogradation in Garaetteok during 3 days at 4℃ with the addition of 0.8% wheat flour. The water holding capacity of the control (CO) and Garaetteok with 0.8% wheat flour added (TR) after storage for 3 days was 45.8% and 76.0% respectively compared with that in the initial storage stage. The water solubility of TR showed higher values than that of CO throughout the storage period, and the difference between CO and TR increased as the storage period increased. For the X-ray diffraction (XRD) pattern, CO showed an A-type pattern and the peak was sharp with the peak size increasing as the storage period increased, whereas TR showed a single peak throughout the storage period. Enthalpy changes (ΔE) by differential scanning calorimeter (DSC) of CO and TR after storage for 3 days were 851.8 and 16.1 J/kg respectively with hardness of 96.3 and 4.0 N respectively, which were significantly different at the 0.1% level.
Physicochemical Properties of Puffed Rice Snack Using Alkali-cooked Brown Rice
Authors: Jeon Hye-Ri , Choi Eun-Hee , Lee Si-Yeon , Park Jun-Kyu , Yoo Young-Mi , Jo Eun-Kyong , Lee Jae-Kwon
Published: May 2014

Physicochemical and sensory properties of puffed rice snack containing various levels (0%, 50%, 100%) of alkalicooked brown rice were examined. To prepare alkali-cooked rice, brown rice was cooked in boiling 2% Ca(OH)2 solution for 5 min, steeped for 3 h, and dried at 50℃ for 18 h. Alkali-cooked rice showed a higher degree of expansion than that of untreated rice after puffing. Although moisture content, enzyme susceptible starch (ESS), and density of puffed rice snack decreased with increasing amounts of the alkali-cooked rice replacement, calcium content increased because of the absorption of calcium during alkaline processing. The puffed rice snack had a darker color as the level of replacement with alkali-cooked rice increased. A sensory test revealed that puffed rice snack replaced with 50% of alkali-cooked rice had no significant differences in color and sensory attributes from those of the control. These results indicate that fortification of calcium could be achieved by partial replacement of alkalicooked rice without any detrimental effects on the quality of puffed rice snack.
Nitrate Nitrogen Reduction Technology for Safe Groundwater Drinking
Authors: Choi Kyeong-Ok , Seo Seok Jin , Ko Sanghoon
Published: May 2014

Excessive nitrate content in drinking groundwater is one of the sources of nitrate-nitrogen that threatens human health all over the world. Nitrate-nitrogen reduction technology is categorized into membrane filtration, electro-dialysis, ion exchange, adsorption, chemical methods, and biological methods according to the principle of elimination from water. In particular, an adsorption technique is the most popular and common process because of its cost effectiveness, convenience, and effective adsorption. In this review, the application of conventional adsorbents used to reduce nitrate-nitrogen from drinking water is discussed and novel technologies on nitrate-nitrogen removal are introduced. Furthermore, the recent development of novel nitrate-nitrogen adsorbents from biopolymers such as chitosan and agricultural and industrial byproducts is reviewed.
Characteristics of Makgeolli Sul-dut by Pre-treatment of Rice and Koji
Authors: Lee Jin-Ho , Kim Gye-Won , Shim Jae-Yong
Published: May 2014

This study aimed to evaluate the fermentation profile, organic acid composition, and volatile flavor components in the meshes of Sul-dut prepared using different pre-treatment methods of rice (Godubap, Baeksulgi, and Ikbanjuk) and different fermentation agents (Nuruk and Ipguk). Among the three pre-treatment methods used, Ikbanjuk produced the lowest alcohol content (12.2% for Nuruk and 12.6% for Ipguk) and the titratable acidity of the different fermentation profiles seemed to be related to the degree of gelatinization during the pre-treatment of rice. The degree of gelatinizaion for Godubab and Baeksulgi was 100%, while that for Ikbanjuk was only 62.5%. Generally, titratable acidity was higher in the Ipguk group compared with the Nuruk group regardless of the pre-treatment method. Citric acid was the major organic acid in the Ipguk group, while lactic acid was the major organic acid in the Nuruk group. In particular, Ikbanjuk produced the largest amount of lactic acid in Nuruk. Volatile flavor components of Sul-dut were largely dependent on the fermentation agents and were less affected by the pre-treatment method.
Effect of Temperature of Steamed Rice Powder at Addition of Wheat Flour on Quality Characteristics of Injeolmi
Authors: Kim Hee-Sun , Han Gwi-Jung , Kim Kyung-Mi , Lee Hyeon-Gyu , Kim Myung-Hwan
Published: May 2014

This study was to investigate the effects of differences in the temperature of steamed rice powder at the addition of wheat flour on the quality characteristics of Injeolmi after storage for 7 days at 4℃. The L values in color of the control and with 75℃ and 95℃ treatments decreased after storage whereas that of the 55℃ treatment increased from 94.24 to 96.07. The amylose content of the control increased from 4.13% to 12.43%, while that of the 55℃, 75℃, and 95℃ treatments increased from 5.10%, 5.28%, and 5.14% to 20.43%, 19.8%, and 19.34% respectively. Hardness of the 55℃, 75℃, and 95℃ treatments after storage increased by 109.2%, 2,023.2%, and 2,886.5% respectively compared with that at the initial storage stage. Hardness of the 55℃ treatment after storage was 3.17% compared with that of the control, which shows that the 55℃ treatment significantly reduced retrogradation in Injeolmi during storage. Total aerobic bacteria content of the control and the 55℃ treatment was 3.55 and 3.98 log CFU/g respectively, which were slightly higher numbers than those of the 75℃ (3.62 log CFU/g) and 95℃ (3.30 log CFU/g) treatments after storage for 7 days at 4℃.
Do We Now Know What Inappropriate Laboratory Utilization Is?
Authors: Hauser Ronald G. , Shirts Brian H.
Published: May 2014

Objectives:

Many nonpathologists and some pathologists consider utilization review essential to laboratory quality improvement, but (1) confusion surrounding the definition of “appropriate” laboratory utilization, (2) the reliance on manual chart review, and (3) a lack of leadership have contributed to its unstandardized implementation. How the solutions to these barriers have evolved since the 1950s is described.

Methods:

A systematic literature review is used.

Results:

Current literature largely defines inappropriate laboratory utilization as any test order in violation of a guideline produced by a government or professional society. Audits performed without manual chart review (ie, database query) have dramatically increased since the mid-1990s. Most utilization audits do not involve any author with a pathology or laboratory medicine affiliation.

Conclusions:

Literature consensus defining “inappropriate” utilization combined with the adoption of database technology has removed key obstacles to utilization reviews. Leadership is needed to unify and benchmark laboratory utilization.
Sustainability, new economics and policy: Greening pathway for the auto industry
Authors: Hwang Kwangseon
Published: May 2014

There have been several arguments from scholars on the question of how we can attain sustainable development (SD). The aim of the article is to explore realistic policies and programmes for achieving sustainable auto manufacturing with a question of ‘how do we manufacture vehicles in a way that is sustainable?’ To discuss how we can achieve sustainable auto manufacturing, I draw on a framework consisting of four innovations–technological, organizational, institutional and social change–and three sustainability pillars–economic development, the environment and employment. All four kinds of innovation need to receive attention in a coordinated manner and careful government policies are needed, thereby reaching a certain sustainability goal.
Singularities on the base of a Fano type fibration
Authors: Birkar Caucher
Published: May 2014

Let

f
:
X
→
Z

${f\colon X\rightarrow Z}$

be a Mori fibre space. McKernan conjectured that the
singularities of Z are bounded in terms of the singularities of X. Shokurov independently
proposed a more general conjecture in the
setting of pairs: let (X,B) be a pair with klt singularities
and

f
:
X
→
Z

${f\colon X\rightarrow Z}$

be a contraction such that

K
X

+
B

∼
ℝ

0
/
Z

$K_X+B\sim _\mathbb {R}0/Z$

and
that the general fibres of f are Fano type varieties; adjunction for fibre spaces produces a
discriminant divisor BZ
and a moduli divisor MZ
on Z.
It is then conjectured that the singularities of

(
Z
,

B
Z

+

M
Z

)

${(Z,B_Z+M_Z)}$

are bounded in terms of the
singularities of (X,B). We prove Shokurov's conjecture when

(
F
,
Supp

B
F

)

${(F,\operatorname{Supp}B_F)}$

belongs
to a bounded family where F is a general fibre of f and

K
F

+

B
F

=

(

K
X

+
B
)

|

F

${K_F+B_F=(K_X+B)|_F}$

.
Slow relaxation mode of sodium lignosulfonate in saline solutions
Authors: Qian Yong , Deng Yonghong , Qiu Xueqing , Lou Hongming , Pang Yuxia
Published: May 2014

Sodium lignosulfonate (NaLS) was dissolved in saline solutions, and the dissolving process was examined by a combination of static and dynamic light scattering. When NaLS was dissolved in 1.2 mol l-1 NaCl solution for 24 h and filtered through a 0.45 μm syringe filter, only a fast relaxation mode was observed, which was attributed to the co-diffusion of NaLS molecular ions and counterions. When the concentration of NaCl was below 1.2 mol l-1 or the dissolving time was <24 h, an additional slow relaxation mode (SRM) appeared due to hindered motions of electrostatically interacting chains. Without filtering or filtering followed by rising temperature to 38°C, SRM appeared due to aggregation, which occurred at a position similar to that caused by electrostatic interaction. For poly(sodium styrenesulfonate) (NaPSS) and modified bamboo lignin derivate with open polyelectrolyte structures, 0.1 mol l-1 NaCl was enough to inhibit the electrostatic interaction. For NaLS with a closed polyelectrolyte structure, the SRM could not be removed until the concentration of NaCl reached 1.2 mol l-1. Above observations give insights for the first time into the relationship between the SRM caused by electrostatically interacting chains and the diffusion mode due to NaLS aggregation, and the influence of the closed polyelectrolyte structure on the SRM.
Assessment of Quality Attributes of Banana Slices Dried by Different Drying Methods
Authors: Pirnazari Kianoosh , Esehaghbeygi Ali , Sadeghi Morteza
Published: May 2014

In the present study, banana slices were dried and compared using electrohydrodynamic (EHD) drying method at 4.5, 6.5, and 8.5 kV/cm; oven at 50, 60, and 70°C; and hot-air drying at 50, 60, and 70°C at a constant air velocity of 1.5 m/s. ANOVA showed that drying method had a significant effect on drying time, rehydration capacity, shrinkage, color features (L*, a*, b*, and ∆E), and consumed energy. The values of consuming energy for EHD at 8.5 kV/cm, oven, and hot-air drying at 70°C were 2.99, 20.9, and 81.7 kJ/g run on full capacity of each dryer, respectively. Oven drying led to a greater color change than did hot-air. No significant difference was observed between the color change feature ∆E for EHD and hot-air dried samples in the orthogonal contrast analysis. The falling rate period for EHD moisture movement showed that diffusion was describing the moisture gradients and the internal moisture transfer was dominant. EHD is not fast; however, its advantages like less energy needed, lower shrinkage, and great rehydration capacity make it a good choice for combining with other convection drying methods.
Inverse free boundary problems for a generally degenerate parabolic equation
Authors: Huzyk Nadiya
Published: May 2014

In a free boundary domain we consider inverse problems for determination
a time-dependent coefficient at the first derivative of an unknown function in a generally
degenerate parabolic equation with different overdetermination conditions. There are established conditions of existence and
uniqueness of the classical solutions to the named problems in the case of the weak degeneration.
Racial/ethnic differences in the birth prevalence of congenital anomalies in the United States
Authors: Egbe Alexander , Lee Simon , Ho Deborah , Uppu Santosh , Srivastava Shubhika
Published: May 2014

Objectives: This work aimed to analyze a single large representative population to determine racial/ethnic differences in the prevalence of congenital anomalies (CA).

Design: This is a population-based comprehensive analysis of racial/ethnic differences in the prevalence of CA diagnoses. We reviewed all live births in the 2008 Nationwide Inpatient Sample (NIS) database and determined the birth prevalence of 55 selected CA diagnoses in Caucasians. We then calculated the relative risk of these CA diagnoses in African American, Hispanics, and Asians relative to Caucasians.

Result: Overall CA prevalence was 29.2 per 1000 in a cohort of 1,048,252 live births, of which 51% were Caucasians. Compared with Caucasians, risk of overall CA was lower in African Americans (RR=0.9, CI: 0.8–0.9) and Hispanics (RR=0.9, CI: 0.8–0.9). Risk of overall CA was similar in Caucasians and Asians. Relative to the Caucasians, African Americans had lower risk of cardiac, genitourinary, and craniofacial CA but higher risk of musculoskeletal anomalies. Hispanics had lower risk of genitourinary and gastrointestinal CA. Asians had higher risk of craniofacial and musculoskeletal CA.

Conclusions: Observed racial/ethnic differences in risk of CA may be related to genetic susceptibilities, cultural or social differences that could modify exposures, or many potential combinations between susceptibilities and exposures.
S100A1 is released from ischemic cardiomyocytes and signals myocardial damage via Toll‐like receptor 4
Authors: Rohde David , Schön Christoph , Boerries Melanie , Didrihsone Ieva , Ritterhoff Julia , Kubatzky Katharina F , Völkers Mirko , Herzog Nicole , Mähler Mona , Tsoporis James N , Parker Thomas G , Linke Björn , Giannitsis Evangelos , Gao Erhe , Peppel Karsten , Katus Hugo A , Most Patrick
Published: May 2014

Members of the S100 protein family have been reported to function as endogenous danger signals (alarmins) playing an active role in tissue inflammation and repair when released from necrotic cells. Here, we investigated the role of S100A1, the S100 isoform with highest abundance in cardiomyocytes, when released from damaged cardiomyocytes during myocardial infarction (MI). Patients with acute MI showed significantly increased S100A1 serum levels. Experimental MI in mice induced comparable S100A1 release. S100A1 internalization was observed in cardiac fibroblasts (CFs) adjacent to damaged cardiomyocytes. In vitro analyses revealed exclusive S100A1 endocytosis by CFs, followed by Toll‐like receptor 4 (TLR4)‐dependent activation of MAP kinases and NF‐κB. CFs exposed to S100A1 assumed an immunomodulatory and anti‐fibrotic phenotype characterized i.e. by enhanced intercellular adhesion molecule‐1 (ICAM1) and decreased collagen levels. In mice, intracardiac S100A1 injection recapitulated these transcriptional changes. Moreover, antibody‐mediated neutralization of S100A1 enlarged infarct size and worsened left ventricular functional performance post‐MI. Our study demonstrates alarmin properties for S100A1 from necrotic cardiomyocytes. However, the potentially beneficial role of extracellular S100A1 in MI‐related inflammation and repair warrants further investigation.
Bypassing the Requirement for an Essential MYST Acetyltransferase
Authors: Torres-Machorro Ana Lilia , Pillus Lorraine
Published: May 2014

Histone acetylation is a key regulatory feature for chromatin that is established by opposing enzymatic activities of lysine acetyltransferases (KATs/HATs) and deacetylases (KDACs/HDACs). Esa1, like its human homolog Tip60, is an essential MYST family enzyme that acetylates histones H4 and H2A and other nonhistone substrates. Here we report that the essential requirement for ESA1 in Saccharomyces cerevisiae can be bypassed upon loss of Sds3, a noncatalytic subunit of the Rpd3L deacetylase complex. By studying the esa1∆ sds3∆ strain, we conclude that the essential function of Esa1 is in promoting the cellular balance of acetylation. We demonstrate this by fine-tuning acetylation through modulation of HDACs and the histone tails themselves. Functional interactions between Esa1 and HDACs of class I, class II, and the Sirtuin family define specific roles of these opposing activities in cellular viability, fitness, and response to stress. The fact that both increased and decreased expression of the ESA1 homolog TIP60 has cancer associations in humans underscores just how important the balance of its activity is likely to be for human well-being.
Structural features and dopant gradients in Mg2SnXSi1-X ternary compounds
Authors: Hatzikraniotis E. , Polymeris G.S. , Lioutas C.B. , Burkov A. , Stefanaki E-C. , Samunin A. , Isachenko G. , Fedorov M.I. , Paraskevopoulos K.M.
Published: May 2014

In the present work, a comparative study is attempted, dealing with the influence of the grain size distribution on the microstructure and the free carrier concentration in Mg2SnXSi1-X (x=0.2) ternary compounds doped with Sb. Structural in-homogeneities were monitored by using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) as well as Fourier transform infrared spectroscopy (FTIR) in the reflectivity mode.
Behaviour of clay-fouled ballast under cyclic loading
Authors: TENNAKOON N. , INDRARATNA B.
Published: May 2014

Expansion of the rail network in congested coastal Australia compels track construction on soft clayey subgrade, including fine-grained estuarine soils. In such low-lying areas, where the water table is close to the ground surface, the saturated soft subgrade is often subjected to pumping (mud slurry) under the application of cyclic wheel loads, thereby causing fouling of the overlying ballast. This technical note presents the results of a series of large-scale, drained, cyclic, triaxial tests conducted on clay-fouled ballast. The impact of fouling on the stress–strain behaviour, resilient modulus and degradation of ballast is discussed.
Clinical Outcomes Following Regenerative Therapy of Non‐Contained Intrabony Defects Using a Deproteinized Bovine Bone Mineral Combined With Either Enamel Matrix Derivative or Collagen Membrane
Authors: Iorio‐Siciliano Vincenzo , Andreuccetti Gianmaria , Blasi Andrea , Matarasso Marco , Sculean Anton , Salvi Giovanni E.
Published: May 2014

Background: The purpose of this study is to compare clinical outcomes in the treatment of deep non‐contained intrabony defects (i.e., with ≥70% 1‐wall component and a residual 2‐ to 3‐wall component in the most apical part) using deproteinized bovine bone mineral (DBBM) combined with either enamel matrix protein derivative (EMD) or collagen membrane (CM).

Methods: Forty patients with multiple intrabony defects were enrolled. Only one non‐contained defect per patient with an intrabony depth ≥3 mm located in the interproximal area of single‐ and multirooted teeth was randomly assigned to the treatment with either EMD + DBBM (test: n = 20) or CM + DBBM (control: n = 20). At baseline and after 12 months, clinical parameters including probing depth (PD) and clinical attachment level (CAL) were recorded. The primary outcome variable was the change in CAL between baseline and 12 months.

Results: At baseline, the intrabony component of the defects amounted to 6.1 ± 1.9 mm for EMD + DBBM and 6.0 ± 1.9 mm for CM + DBBM sites (P = 0.81). The mean CAL gain at sites treated with EMD + DBBM was not statistically significantly different (P = 0.82) compared with CM + DBBM (3.8 ± 1.5 versus 3.7 ± 1.2 mm). No statistically significant difference (P = 0.62) was observed comparing the frequency of CAL gain ≥4 mm between EMD + DBBM (60%) and CM + DBBM (50%) or comparing the frequency of residual PD ≥6 mm between EMD + DBBM (5%) and CM + DBBM (15%) (P = 0.21).

Conclusion: Within the limitations of the present study, regenerative therapy using either EMD + DBBM or CM + DBBM yielded comparable clinical outcomes in deep non‐contained intrabony defects after 12 months.
Evaluation of Efficacy of Chlorhexidine Intracanal Medicament on the Periodontal Healing of Concomitant Endodontic‐Periodontal Lesions Without Communication: An Interventional Study
Authors: Raheja Jyoti , Tewari Sanjay , Tewari Shikha , Duhan Jigyasa
Published: May 2014

Background: Treatment of concomitant endodontic‐periodontal lesions remains a challenge in clinical practice and requires effective endodontic and regenerative periodontal therapy. Among other factors, cross seeding and recolonization of flora may affect the outcome of periodontal therapy. Intracanal medicaments have been shown to exert antimicrobial activity on the external root surface, and local delivery of antimicrobials has been suggested to be a complementary approach in the management of periodontitis. Therefore, the objective of this study is to determine the influence of chlorhexidine (CHX) intracanal medicament on the clinical outcomes of therapy.

Methods: Thirty‐one patients were divided into two treatment groups: 1) open flap debridement (OFD) in endodontically treated teeth (control); and 2) OFD in endodontically treated teeth with CHX placed in the coronal space (test). The clinical variables evaluated were probing depth (PD), clinical attachment level (CAL), and percentage of sites with PD ≥5 mm. Reevaluation was performed at 3 and 6 months post‐surgery.

Results: Both treatments resulted in improvement in all the clinical variables evaluated. Postoperative measurements from test and control groups showed reductions in mean PD of 2.22 ± 1.27 and 0.91 ± 0.81 mm, mean CAL gains of 2.16 ± 1.12 and 0.60 ± 0.93 mm, and 43.33% ± 31.37% and 17.71% ± 14.23% reduction in sites with PD ≥5 mm. Significantly more PD reduction, CAL gain, and percentage reduction in sites with PD ≥5 mm were observed in the test group at 6 months (P <0.05).

Conclusion: CHX may be used as an effective intracanal medicament for promoting periodontal healing in concomitant endodontic‐periodontal lesions.
Short‐Term Effects of Non‐Surgical Periodontal Treatment on the Gingival Crevicular Fluid Cytokine Profiles in Sites With Induced Periodontal Defects: A Study on Dogs With and Without Streptozotocin‐Induced Diabetes
Authors: Javed Fawad , Al‐Daghri Nasser M. , Wang Hom‐Lay , Wang Cun Yu , Al‐Hezaimi Khalid
Published: May 2014

Background: The aim of this study is to assess the short‐term effects of non‐surgical periodontal therapy (NSPT) on the gingival crevicular fluid (GCF) cytokine profile in sites with standardized periodontal bony defects in beagle dogs with and without diabetes.

Methods: Four beagle dogs with streptozotocin (STZ)‐induced diabetes and four healthy dogs were included. Fasting blood glucose levels were measured using a glucometer. In all animals, a 3‐walled bony defect was created on the mesial surface of the second premolar and first molar in all quadrants. After 12 weeks, all animals underwent weekly NSPT for 3 weeks. Baseline and post‐NSPT GCF samples were collected, and levels of interleukin (IL)‐1, IL‐1β, IL‐6, IL‐8, and tumor necrosis factor (TNF)‐α were measured using enzyme‐linked immunosorbent assay. Statistical analyses were performed using a software program, and P values <0.05 were considered statistically significant.

Results: Mean fasting blood glucose levels were significantly higher in dogs with induced diabetes than those without diabetes (P <0.01). At baseline, mean IL‐6 (P <0.01) and IL‐8 (P <0.05) levels were higher in dogs with diabetes than those without diabetes. A significant reduction in levels of IL‐1, IL‐1β, IL‐6, IL‐8, and TNF‐α was noted in dogs without diabetes 1 week after NSPT. However, this significant reduction (P <0.05) only appeared 2 weeks after NSPT in dogs with diabetes.

Conclusions: NSPT reduces GCF levels of proinflammatory cytokines in dogs with and without STZ‐induced diabetes; however, chronic hyperglycemia seems to retard the effect of NSPT on GCF cytokine concentration.
On the Temporal Fidelity of Nonlinear Inverse Reconstructions for Real- Time MRI – The Motion Challenge
Authors: Frahm Jens , Schätz Sebastian , Untenberger Markus , Zhang Shuo , Voit Dirk , Merboldt K. Dietmar , Sohns Jan M. , Lotz Joachim , Uecker Martin
Published: May 2014

Purpose:

To evaluate the temporal accuracy of a self-consistent nonlinear inverse reconstruction method
(NLINV) for real-time MRI using highly undersampled radial gradient-echo sequences and to present an open source
framework for the motion assessment of real-time MRI methods.

Methods:

Serial image reconstructions by NLINV combine a joint estimation of individual frames and corresponding coil
sensitivities with temporal regularization to a preceding frame. The temporal fidelity of the method was determined with a
phantom consisting of water-filled tubes rotating at defined angular velocity. The conditions tested correspond to real-time
cardiac MRI using SSFP contrast at 1.5 T (40 ms resolution) and T1 contrast at 3.0 T (33 ms and 18 ms resolution).
In addition, the performance of a post-processing temporal median filter was evaluated.

Results:

NLINV reconstructions without temporal filtering yield accurate estimations as long as the speed of a small
moving object corresponds to a spatial displacement during the acquisition of a single frame which is smaller than the
object itself. Faster movements may lead to geometric distortions. For small objects moving at high velocity, a median
filter may severely compromise the spatiotemporal accuracy.

Conclusion:

NLINV reconstructions offer excellent temporal fidelity as long as the image acquisition time is short enough
to adequately sample (“freeze”) the object movement. Temporal filtering should be applied with caution. The motion
framework emerges as a valuable tool for the evaluation of real-time MRI methods.