bluuebunny/crossref_metadata_2025 huggingface dataset:
Graphene with Covalently Grafted Amino Acid as a Route Toward Eco‐Friendly and Sustainable Supercapacitors
Authors: Vermisoglou Eleni C. , Jakubec Petr , Bakandritsos Aristides , Kupka Vojtěch , Pykal Martin , Šedajová Veronika , Vlček Jakub , Tomanec Ondřej , Scheibe Magdalena , Zbořil Radek , Otyepka Michal
Published: July 2021

Eco‐friendly, electrochemically active electrode materials based on covalent graphene derivatives offer enormous potential for energy storage applications. However, covalent grafting of functional groups onto the graphene surface is challenging due to its low reactivity. Here, fluorographene chemistry was employed to graft an arginine moiety via its guanidine group homogeneously on both sides of graphene. By tuning the reaction conditions and adding a non‐toxic pore‐forming agent, an optimum degree of functionalization and hierarchical porosity was achieved in the material. This tripled the specific surface area and yielded a high capacitance value of approximately 390 F g−1 at a current density of 0.25 A g−1. The applicability of the electrode material was investigated under typical operating conditions by testing an assembled supercapacitor device for up to 30000 charging/discharging cycles, revealing capacitance retention of 82.3 %. This work enables the preparation of graphene derivatives with covalently grafted amino acids for technologically important applications, such as supercapacitor‐based energy storage.
Valorization of Small Alkanes by Biocatalytic Oxyfunctionalization
Authors: Mahor Durga , Cong Zhiqi , Weissenborn Martin J. , Hollmann Frank , Zhang Wuyuan
Published: July 2021

The oxidation of alkanes into valuable chemical products is a vital reaction in organic synthesis. This reaction, however, is challenging, owing to the inertness of C−H bonds. Transition metal catalysts for C−H functionalization are frequently explored. Despite chemical alternatives, nature has also evolved powerful oxidative enzymes (e. g., methane monooxygenases, cytochrome P450 oxygenases, peroxygenases) that are capable of transforming C−H bonds under very mild conditions, with only the use of molecular oxygen or hydrogen peroxide as electron acceptors. Although progress in alkane oxidation has been reviewed extensively, little attention has been paid to small alkane oxidation. The latter holds great potential for the manufacture of chemicals. This Minireview provides a concise overview of the most relevant enzyme classes capable of small alkanes (C<6) oxyfunctionalization, describes the essentials of the catalytic mechanisms, and critically outlines the current state‐of‐the‐art in preparative applications.
Current advances in digital cognitive assessment for preclinical Alzheimer's disease
Authors: Öhman Fredrik , Hassenstab Jason , Berron David , Schöll Michael , Papp Kathryn V.
Published: July 2021

There is a pressing need to capture and track subtle cognitive change at the preclinical stage of Alzheimer's disease (AD) rapidly, cost‐effectively, and with high sensitivity. Concurrently, the landscape of digital cognitive assessment is rapidly evolving as technology advances, older adult tech‐adoption increases, and external events (i.e., COVID‐19) necessitate remote digital assessment. Here, we provide a snapshot review of the current state of digital cognitive assessment for preclinical AD including different device platforms/assessment approaches, levels of validation, and implementation challenges. We focus on articles, grants, and recent conference proceedings specifically querying the relationship between digital cognitive assessments and established biomarkers for preclinical AD (e.g., amyloid beta and tau) in clinically normal (CN) individuals. Several digital assessments were identified across platforms (e.g., digital pens, smartphones). Digital assessments varied by intended setting (e.g., remote vs. in‐clinic), level of supervision (e.g., self vs. supervised), and device origin (personal vs. study‐provided). At least 11 publications characterize digital cognitive assessment against AD biomarkers among CN. First available data demonstrate promising validity of this approach against both conventional assessment methods (moderate to large effect sizes) and relevant biomarkers (predominantly weak to moderate effect sizes). We discuss levels of validation and issues relating to usability, data quality, data protection, and attrition. While still in its infancy, digital cognitive assessment, especially when administered remotely, will undoubtedly play a major future role in screening for and tracking preclinical AD.
The effects of lower body compression on left ventricular rotational mechanics in lymphoedema (from the MAGYAR‐Path Study)
Authors: Nemes Attila , Kormányos Árpád , Domsik Péter , Kalapos Anita , Kemény Lajos , Szolnoky Győző
Published: July 2021

Aims

Lower body half compression of bilateral secondary leg lymphoedema (LE) without relevant cardiac insufficiency gives rise to whether external leg compression may influence left ventricular (LV) function. Patients with LE were subjected to baseline two‐dimensional transthoracic echocardiography (2DTTE) for general assessment then three‐dimensional speckle‐tracking echocardiography (3DSTE) before and 1 h after lower body half external compression for LV torsion analysis.

Methods and results

Baseline 2DTTE was performed in the cohort of 25 LE patients, and the results were compared with those of age‐ and gender‐matched 52 healthy controls (mean age: 47.8 ± 12.8 vs. 40.7 ± 14.0 years, 24 women/1 man vs. 49 women/3 men, respectively). 3DSTE was conducted for the assessment of LV rotational mechanics where apical (AR), and basal rotations (BR) were measured before and 1 h after the use of compression class 2 (ccl 2) flat‐knitted medical compression pantyhoses (pressure range: 23–32 mmHg). 2DTTE showed significantly larger LV end‐diastolic volume and ejection fraction among LE patients compared with control subjects (108.3 ± 20.1 vs. 98.5 ± 21.7 mL, 69.8 ± 4.8 vs. 65.5 ± 4.3%, respectively) and notably smaller LV end‐systolic diameter and posterior wall thickness (28.9 ± 3.5 vs. 31.2 ± 3.4 mm, 8.1 ± 1.0 vs. 9.0 ± 1.7 mm, respectively). The results of 20 patients with LE were considered in 3DSTE examinations due to the drop‐out of five probands with technical failures. The data of four LE patients showing significant LV rotational abnormalities were managed separately, and the rotational parameters of the remaining sixteen patients did not differ significantly from those of matched controls except significant reduction of LV BR following the application of medical compression stockings (MCS) (−2.70 ± 1.26 degrees after 1 h use of pantyhose in patient group vs. −4.28 ± 2.18 degrees of the control group; P < 0.05).

Conclusions

The application of compression pantyhoses moderately but significantly decreased LV BR without a remarkable impact on twisting mechanism in LE patients in the absence of LV rotational abnormalities.
Alkali Metallosilicates: Synthesis, Structure and Evaluation in the ROP of ϵ‐Caprolactone
Authors: Pérez‐Pérez Jovana , Hernández‐Balderas Uvaldo , Martínez‐Otero Diego , Moya‐Cabrera Mónica , Jancik Vojtech
Published: July 2021

A series of metallosilicate complexes (tBuO)2(RO)SiOM (R=tBu, iPr, Et, Me; M=Li, Na, K) were prepared from tailor‐made silanols. The complexes show different degree of association and feature heterocubane, double‐heterocubane or hexagonal prism framework in solid state while ESI‐MS shows fragmentation of the oligomers. The steric hindrance around the silicon atom has a direct influence over the association of the alkali derivatives, and the size of the alkali metal influences the shape of the MxOx core. These compounds were studied as initiators in the ROP of ϵ‐caprolactone, varying temperature, reaction‐time, monomer/initiator ratio, metal center variation and association degree. The best results were achieved with [{(tBuO)3SiO}4Li4] (1) producing an almost quantitive yield of polycaprolactone (97 %, Mn=35 kg mol−1, Mw/Mn=1.72).
Hydrogen‐Bonding Interactions of Methylated Adenine Derivatives
Authors: Osifová Zuzana , Socha Ondřej , Mužíková Čechová Lucie , Šála Michal , Janeba Zlatko , Dračínský Martin
Published: July 2021

Hydrogen bonding between nucleobases is a crucial noncovalent interaction for the life on Earth. Apart from Watson‐Crick binding, Hoogsteen pairing has been found in many structures of nucleic acids. Methylation of nucleic acids (NAs) is a post‐replication or post‐transcription mechanism that can modulate the structure and function of a NA without changing its sequence. Methylation of adenine at the N6 position to form m6A is one of the most important and common epigenetic markers. This paper describes an investigation of intermolecular H‐bonding interactions of methylated derivatives of adenine with its complementary partner, thymine. Adenine derivatives with (di)methylamino groups in positions 2 or 6 have been prepared and their interactions with a thymine derivative have been studied by NMR spectroscopy and DFT calculations. It has been found that Hoogsteen pairing is preferred for adenine derivatives, which offer two hydrogen‐bond sites on both Watson‐Crick and Hoogsteen sides of the molecule. Methylation of the N6 position leads to further stabilization of the Hoogsteen pair.
Modulatory role of the orexin system in stress‐induced analgesia: Involvement of the ventral tegmental area
Authors: Askari Kobra , Oryan Shahrbanoo , Eidi Akram , Zaringhalam Jalal , Haghparast Abbas
Published: July 2021

Background

Exposure to stressful experiences is often accompanied by suppressing pain perception, referred to as stress‐induced analgesia. The neuropeptides orexins are essential in regulating the mechanism that responds to stressful and painful stimuli. Meanwhile, the ventral tegmental area (VTA), as a part of descending pain inhibitory system, responds to noxious stimuli. This study aimed to investigate the role of intra‐VTA administration of orexin receptor antagonists on stress‐induced antinociceptive responses in the animal model of acute pain.

Method

Ninety‐three adult Wistar rats weighing 230–250 g were unilaterally implanted by a cannulae above the VTA. Animals were pretreated with different doses (1, 3, 10 and 30 nM/0.3 μl) of SB334867 as the orexin‐1 receptor antagonist and TCS OX2 29 as the orexin‐2 receptor antagonist into the VTA, just 5 min before 6 min exposure to forced swim stress (FSS). Nociceptive threshold was measured using the tail‐flick test as a model of acute pain.

Results

The results showed that exposure to FSS could significantly increase analgesic responses. Moreover, intra‐VTA administration of SB334768 and TCS OX2 29 blocked the antinociceptive effect of FSS in the tail‐flick test.

Conclusion

The findings suggest that OX1 and OX2 receptors in the VTA might modulate the antinociceptive behaviours induced by FSS in part.

Significance

Acute exposure to physical stress suppresses pain‐related behaviors in the animal model of acute pain. Blockade of the OX1 and OX2 receptors in the VTA attenuates antinociceptive responses induced by FSS. The contribution of the OX2 receptors in the VTA is more predominant than OX1 receptors in stress‐induced analgesia.
Phantom limb pain after unilateral arm amputation is associated with decreased heat pain thresholds in the face
Authors: Fuchs Xaver , Diers Martin , Trojan Jörg , Kirsch Pinar , Milde Christopher , Bekrater‐Bodmann Robin , Rance Mariela , Foell Jens , Andoh Jamila , Becker Susanne , Flor Herta
Published: July 2021

Background

The mechanisms underlying chronic phantom limb pain (PLP) are complex and insufficiently understood. Altered sensory thresholds are often associated with chronic pain but quantitative sensory testing (QST) in PLP has so far been inconclusive due to large methodological variation between studies and small sample sizes.

Methods

In this study, we applied QST in 37 unilateral upper‐limb amputees (23 with and 14 without PLP) and 19 healthy controls. We assessed heat pain (HPT), pressure pain, warmth detection and two‐point discrimination thresholds at the residual limb, a homologous point and the thenar of the intact limb as well as both corners of the mouth.

Results

We did not find significant differences in any of the thresholds between the groups. However, PLP intensity was negatively associated with HPT at all measured body sites except for the residual limb, indicating lower pain thresholds with higher PLP levels. Correlations between HPT and PLP were strongest in the contralateral face (r = −0.65,p < 0.001). Facial HPT were specifically associated with PLP, independent of residual limb pain (RLP) and various other covariates. HPT at the residual limb, however, were significantly associated with RLP, but not with PLP.

Conclusion

We conclude that the association between PLP and, especially facial, HPT could be related to central mechanisms.

Significance

Phantom limb pain (PLP) is still poorly understood. We show that PLP intensity is associated with lower heat pain thresholds, especially in the face. This finding could be related to central nervous changes in PLP.
Direct and Delayed Mortality of Ceriodaphnia dubia and Rainbow Trout Following Time-Varying Acute Exposures to Zinc
Authors: Mebane Christopher A. , Ivey Christopher D. , Wang Ning , Steevens Jeffery A. , Cleveland Danielle , Elias Michael C. , Justice James R. , Gallagher Kathryn , Brent Robert N.
Published: July 2021

The potential for delayed mortality following short-term episodic pollution events was evaluated by exposing cladocerans (Ceriodaphnia dubia) and rainbow trout (Oncorhynchus mykiss) to zinc (Zn) in various 1- to 48-h and 1- to 96-h exposures, respectively, followed by transferring the exposed organisms to clean water for up to 47 h for C. dubia and up to 95 h for trout for additional observation. For C. dubia, 1-h exposures of up to 3790 µg Zn/L never resulted in mortality during the actual Zn exposures, but by 48 h, a 1-h exposure to 114 µg/L, a concentration similar to the present US national water quality acute criterion for the test water conditions, ultimately killed 70% of C. dubia. With C. dubia, the speed of action of Zn toxicity was faster for intermediate concentrations than for the highest concentrations tested. For rainbow trout, pronounced delayed mortalities by 96 h only occurred following ≥8-h exposures. For both species, ultimate mortalities from Zn exposures ≤8 h mostly presented as delayed mortalities, whereas for exposures ≥24 h, almost all ultimate mortalities presented during the actual exposure periods. With Zn, risks of delayed mortality following exposures to all concentrations tested were much greater for the more sensitive, small-bodied invertebrate (C. dubia) than for the less sensitive, larger-bodied fish (rainbow trout). These results, along with previous studies, show that delayed mortality is an important consideration in evaluating risks to aquatic organisms from brief, episodic exposures to some substances. Environ Toxicol Chem 2021;40:2484–2498. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Abstract

Rainbow trout could withstand extreme Zn pulses of 1 to 3 h, with few subsequent deaths. Few Ceriodaphnia dubia died during 1- to 3-h Zn pulses, but after 48 h, most were dead. Time to effects decreased as expected as rainbow trout were exposed to increasing Zn concentrations. Not so with C. dubia: time to effects was fastest in intermediate Zn exposures, with longer survivals in higher Zn exposures.
The Impact of Disturbed Soil Structure on the Degradation of 2 Fungicides Under Constant and Variable Moisture
Authors: Hand Laurence H. , Marshall Samantha J. , Dougan Christine , Nichols Carol , Kende Aniko , Ritz Karl , Oliver Robin G.
Published: July 2021

Degradation of agrochemicals in soil is frequently faster under field conditions than in laboratory studies. Field studies are carried out on relatively undisturbed soil, whereas laboratory studies typically use sieved soil, which can have a significant impact on the physical and microbial nature of the soil and may contribute to differences in degradation between laboratory and field studies. A laboratory study was therefore conducted to determine the importance of soil structure and variable soil moisture on the degradation of 2 fungicides (azoxystrobin and paclobutrazol) that show significant differences between laboratory and field degradation rates in regulatory studies. Degradation rates were measured in undisturbed cores of a sandy clay loam soil (under constant or variable moisture contents) and in sieved soil. For azoxystrobin, degradation rates under all conditions were similar (median degradation time [DegT50] 34–37 d). However, for paclobutrazol, degradation was significantly faster in undisturbed cores (DegT50 255 d in sieved soil and 63 d in undisturbed cores). Varying the moisture content did not further enhance degradation of either fungicide. Further examination into the impact of soil structure on paclobutrazol degradation, comparing undisturbed and sieved/repacked cores, revealed that the impact of sieving could not be mitigated by repacking the soil to a realistic bulk density. Examination of fungal and bacterial community structure using automated ribosomal spacer analysis showed significant initial differences between sieved/repacked and intact soil cores, although such differences were reduced at the end of the study (70 d). The present study demonstrates that disruption of soil structure significantly impacts microbial community structure, and for some compounds this may explain the differences between laboratory and field degradation rates. Environ Toxicol Chem 2021;40:2715–2725. © 2021 SETAC

Abstract

Investigation of the impact of retention of soil structure on the degradation rates of azoxystrobin and paclobutrazol.
Sublethal Effect Concentrations for Nonpolar Narcosis in the Zebrafish Embryo
Authors: Massei Riccardo , Knapen Dries , Covaci Adrian , Blust Ronny , Mayer Philipp , Vergauwen Lucia
Published: July 2021

Nonpolar narcosis, also known as baseline toxicity, has been described as the minimal toxicity that an organic chemical may elicit based on its lipophilicity. Although lethal effects of narcosis-inducing chemicals (NICs) have been thoroughly investigated, knowledge of sublethal effects is still very limited. We investigated the effects of 3 well-known NICs (phenanthrene, 1,3,5-trichlorobenzene, and pentachlorobenzene) on a variety of organismal endpoints (malformations, swim bladder inflation, respiration, heart rate, swimming activity, and turning angles), which can be plausibly linked to narcosis in zebrafish embryos. Baseline toxicity recorded as mortality is typically observed in similar exposure ranges in a wide variety of species including fish, corresponding to a chemical activity range between 0.01 and 0.1. In the present study, we found that sublethal effects occurred at concentrations approximately 5 times below lethal concentrations. Altered swimming activity and impaired swim bladder inflation were the most sensitive endpoints occurring at exposure levels below the generally accepted threshold for baseline toxicity for 2 out of 3 compounds. Overall, most effective exposure levels across the sublethal endpoints and compounds did fall within the range typically associated with baseline toxicity, and deviations were generally limited to a factor 10. Although there could be benefit in adding sublethal endpoints to toxicity tests, such as the fish embryo acute toxicity (FET) test, based on the present sublethal endpoints and available evidence from our and other studies, the underestimation of toxicity as a result of the sole assessment of mortality as an endpoint in an FET test may be limited for narcosis. Environ Toxicol Chem 2021;40:2802–2812. © 2021 SETAC
Microencapsulation of Lactobacillus acidophilus LA‐5 and Bifidobacterium animalis BB‐12 in pectin and sodium alginate: A comparative study on viability, stability, and structure
Authors: Motalebi Moghanjougi Zahra , Rezazadeh Bari Mahmoud , Alizadeh Khaledabad Mohammad , Amiri Saber , Almasi Hadi
Published: July 2021

The present study aimed at examining whether the microencapsulation of Lactobacillus acidophilus LA‐5 and Bifidobacterium animalis BB‐12 inside hydrogels could prolong their survival in freeze‐drying conditions, stored at 4℃ and in the gastrointestinal medium. Microencapsulation was performed by emulsion with a syringe, while sodium alginate and high methoxyl pectin were used as a carrier material. A relatively high efficiency of encapsulation was obtained (>92%). Z‐Average and pdI in samples were not significant (p < .05). In different treatments, changes in the number of bacteria after freeze‐drying, 30 days of storage, and gastrointestinal conditions, compared to each other, were significant (p < .05). However, the survival rate after a reduction during storage was higher than 106 cfu/g, indicating the suitability of the microencapsulation process. The surface of microcapsules observed by a scanning electron microscope (SEM) confirmed the success of encapsulation. Finally, a lower decrease in the count of microencapsulated was observed in comparison to the free cells.
COVID‐19 and the Uncovering of Health Care Disparities in the United States, United Kingdom and Canada: Call to Action
Authors: Ala Aftab , Wilder Julius , Jonassaint Naudia L. , Coffin Carla S. , Brady Carla , Reynolds Andrew , Schilsky Michael L.
Published: July 2021

The coronavirus disease 2019 (COVID‐19) pandemic created a crisis that disproportionately affected populations already disadvantaged with respect to access to health care systems and adequate medical care and treatments. Understanding how and where health care disparities are most widespread is an important starting point for exploring opportunities to mitigate such disparities, especially within our patient population with liver disease. In a webinar in LiverLearning, we discussed the impact of the pandemic on the United States, United Kingdom and Canada, highlighting the disproportionate effects on infection rates and death for certain ethnic minorities, those socioeconomically disadvantaged and living in higher density areas, and those working in health care and other essential jobs. We set forth a “call to action” for members of the American Association for the Study of Liver Diseases and the larger community of providers of liver disease care to generate viable solutions to improve access to care and vaccination rates of our patients against COVID‐19, and in general help reduce health care disparities and improve the health of disadvantaged populations within their communities. Solutions will likely involve personalized interventions and messaging for communities that honor local leaders and embrace the diverse needs and different cultural sensitivities of our unique patient populations.
Rethinking health services operations to embrace patient experience of healthcare journey
Authors: Mahdavi Mahdi , Doshmangir Leila , Jaafaripooyan Ebrahim
Published: July 2021

Patient experience is assumed pivotal for improving health services operations. The patient experience of healthcare services in Iran has been mostly assessed through the satisfaction and quality of single services or activities at individual providers, clinical departments, or health facilities. However, given the rise of chronic and multi‐morbid conditions, health services for these conditions consist of several activities and interactions through a journey that patients take in the health system. To fill in this gap, we propose focusing on the assessment of patient experience on the patient journey through the health system. We advocate that there is much potential for improving the patient experience by rethinking the operations management of health services to embrace the patient experience of the healthcare journey. Rethinking health operations management may include an exhaustive list of interventions. Concisely, at the strategic level, policy‐makers while understanding the need for shifting towards the patient experience, make sure that operational level management is experience oriented. This would be pursued through a strategic approach to patient experience, reconsidering qualifications for operational management, and benchmarking to identify and share best practices. Lessons learnt from previous quality improvement programmes are also considered as a capacity to establish the experience orientation.
Dumping on Free Trade: The U.S. Import Trade Laws
Authors: Stiglitz Joseph E.
Published: July 2021

The passage of the Uruguay Round implementing legislation represents a natural opportunity to review the policy goals of the U.S. import trade laws, to assess how well current laws achieve those objectives, and to explore possible reforms. I argue that there is a variety of policy concerns justifying a circumscribed set of import trade statuses. The relevant U.S. laws, however, have largely become divorced from such national welfare considerations and are now too often a mechanism for furtive protectionism. The Uruguay Round effected some (marginal) improvements but left the fundamental structure of the laws unchanged. I discuss possible reforms in the final section of the paper.
Scissors or Horizon: Neoclassical Debates about Returns to Scale, Costs, and Long‐Run Supply, 1926‐1942
Authors: Aslanbeigui Nahid , Naples Michele I.
Published: July 2021

Modern treatment of long‐run (U‐shaped) cost curves developed from reactions to Sraffa's criticisms of Marshall. He argued that internal (dis)economies were incompatible with partial‐equilibrium analysis under perfect competition. Pigou concurred and drew L‐shaped cost curves; Viner realized that this made firm size indeterminate and industry output volatile. Using Austin and Joan Robinson's analyses, Stigler justified rising costs/supply, determinacy, and stability by irrational entrepreneurs enduring coordination failure and by factor price changes. We conclude that consistency requires constant costs but firm employment, output, and factor incomes remain theoretically indeterminate. It becomes likely that large firms will undermine perfect competition.
Quality Expectations, Reputation, and Price
Authors: Landon Stuart , Smith Constance E.
Published: July 2021

Although the theoretical literature on firm reputation is well developed, few empirical studies exist that quantify the importance of reputation effects. This paper estimates the impact on price of current product quality and reputation using data from the market for Bordeaux wine. A model is proposed in which price is a function of current quality and expected quality, where the latter depends on reputation. Equations determining price and expected quality are estimated jointly. The empirical findings show that the price premium associated with a better reputation far exceeds that associated with improvements in current quality. The impact of reputation on price is disaggregated into individual firm and collective (or group) reputation effects, and the significance and magnitude of these effects are compared. The results indicate that both types of reputation are important, and that in general, the market values collective reputation indicators only to the extent that they are useful predictors of product quality.
Fiscal Policy in a Growth Model with Both Altruistic and Nonaltruistic Agents
Authors: Michel Philippe , Pestieau Pierre
Published: July 2021

This paper examines the long‐run behavior of an overlapping generations model with a population consisting of altruistic and nonaltruistic agents. It also studies the effect of fiscal policy on aggregate capital accumulation and on the welfare of both types of agents. It shows that an increase in the relative number of nonaltruists is Pareto‐improving in the steady state. It also shows that the introduction of public debt or unfunded social security has no effect on the long‐run equilibrium but implies a transfer of resources from the nonaltruistic to the altruistic agents. Finally, it indicates that inheritance taxation hurts not only the altruists but also the nonaltruists.
Political Business Cycles and Endogenous Elections
Authors: Heckelman Jac C. , Berument Hakan
Published: July 2021

Empirical research of political business cycles (PBCs) may suffer from endogeneity bias when incumbent governments have discretion to call for an early election. Using an instrumental variable (IV) routine on data from Japan and the U.K., we find strong evidence to support the notion that election timing is a function of the economy rather than the macroeconomy being driven by elections as assumed in PBC. In single‐equation regressions, no evidence of political cycles are found, but Hausman tests suggest elections are endogenous in our regressions. A monetary cycle in Japan and an inflation cycle in the U.K. are uncovered through IV estimation.
The Two Faces of Adam Smith
Authors: Smith Vernon L.
Published: July 2021

Adam Smith's two major works are based on apparently contradictory themes in human nature: noncooperative self‐interest and other‐regarding sympathy. These views are not contradictory if we distinguish impersonal market exchange and personal exchange. Noncooperative behavior in the former maximizes the gains from exchange, the basis of specialization and wealth creation. Cooperative behavior in personal exchange is based on reciprocity—trading gifts, favors, and assistance across time—which maximizes the gains from social exchange. That people can be both cooperative and noncooperative is corroborated in laboratory experiments and is postulated to stem from a self‐interested propensity for exchange in markets and friendships.
Racial Earnings Disparities and Family Structure
Authors: Darity William A. , Myers Samuel L. , Chung Chanjin
Published: July 2021

One explanation for the widening of racial earnings gaps among family heads during the 1980s is that black families were increasingly headed by females during that period. This explanation is tested using data on black and white family heads in 1976 and 1985 from the Institute for Research on Poverty's Current Population Survey. Log‐earnings equations, corrected for selection bias and for the endogeneity of labor force participation, are estimated for blacks and whites in 1976 and 1985. If the impact of rising female‐family headship on labor force participation is ignored, one finds support for the family structure explanation. But support for alternative explanations is also found. There are substantial impacts of within‐race gender discrimination and of market racial discrimination. When the endogeneity of family structure is taken into account, further support is found for the view that endowment differences only explain a modest portion of the rising gap in earnings between black and white family heads.
The Effect of Separation Bonuses on Voluntary Quits: Evidence from the Military's Downsizing
Authors: Mehay Stephen L. , Hogan Paul F.
Published: July 2021

This paper analyzes the decision of mid‐career personnel to voluntarily leave the U.S. military in response to a financial incentive program. A model of the separation decision is tested using data on Navy and Air Force enlisted personnel who were targeted for the buyout in 1992. Two alternative estimates are provided, one from a fixed effects model and one from a structural, annualized cost of leaving model. Our basic results indicate the financial incentive had a modest effect in inducing additional quits. The impact of the separation bonus, however, was much larger for occupations facing a threat of involuntary layoff.
Taxation, Fines, and Producer Liability Rules: Efficiency and Market Structure Implications
Authors: Hamilton Stephen F.
Published: July 2021

This paper analyzes the comparative efficiency of producer liability rules and regulatory policy in short‐run and long‐run competitive equilibria with endogenous product safety. Pigouvian taxes on output and safety provision fail to achieve the long‐run social optimum. An appropriately designed policy involving fines on accidents and subsidies on safety provision achieves efficiency; however, the optimal policy may involve the taxation, not the subsidization, of product safety. Tort liability also leads to efficient outcomes but may be associated with perverse structural changes. For example, increased liability exposure may induce de novo entry in hazardous sectors, even with fully capitalized firms.
Part‐Whole Bias in Contingent Valuation: Will Scope Effects Be Detected with Inexpensive Survey Methods?
Authors: Whitehead John C. , Haab Timothy C. , Huang Ju‐Chin
Published: July 2021

The purpose of this paper is to test for scope effects with the contingent valuation method. We use data from a telephone survey focusing on water quality improvements in the Albemarle and Pamlico Sounds in North Carolina. We find that the willingness to pay estimates are sensitive to the scope of the policy. These results suggest that the use of inexpensive survey methods may not be the cause of the failure to detect scope effects in some recent contingent valuation studies.
The Leverage Theory of Tying Revisited: Evidence from Newspaper Advertising
Authors: Slade Margaret E.
Published: July 2021

Data from the Canadian newspaper‐advertising industry is used to assess the private profitability of tying in a market where the standard efficiency motives (e.g., price discrimination, cost saving, and quality control) are unlikely to apply. The empirical assessment is based on a model of leveraging in which suppliers of the tied good are paid a commission rather than a fee for service. This model demonstrates that tying is profitable under a wide range of circumstances. Furthermore, it is found that, with newspapers, tying and monopoly power go hand in hand.
Discrimination by Gender and Disability Status: Do Worker Perceptions Match Statistical Measures?
Authors: Hallock Kevin F. , Hendricks Wallace , Broadbent Emer
Published: July 2021

We explore whether perceptions of discrimination are related to ordinary statistical measures. The majority of disabled respondents report feeling some discrimination due to their disability, the majority of women feel some discrimination because of their gender, and a surprising number of men also report some discrimination. We do not find a strong link between perceptions of discrimination and measured discrimination perhaps because those who perceive discrimination feel that it occurs along other dimensions than pay. However, we do find a connection between whether a person feels his or her income is inadequate and measured discrimination for all groups studied.
Switching Costs in the Wholesale Distribution of Cigarettes
Authors: Elzinga Kenneth G. , Mills David E.
Published: July 2021

Recent theories of price wars triggered by entry assign a critical role to switching costs in explaining price and output changes. Earlier, Elzinga and Mills (1998) showed that actual switching patterns following an episode of new entry in an industry are driven by the fact that buyers have different switching costs. The current paper draws on transaction‐specific price and shipments data surrounding the 1984‐1985 price war in generic cigarettes to explore the size and determinants of switching costs among wholesale cigarette distributors. Results show that switching costs vary across firms and are nontrivial in magnitude. Several implications of the findings are discussed.
Are the Roots of the ModernLex MercatoriaReally Medieval?
Authors: Volckart Oliver , Mangels Antje
Published: July 2021

This article analyzes how trade was conducted between the tenth and thirteenth centuries. We claim that, as most exchange was simultaneous, differences between law codes did not pose a substantial problem and that mercantile guilds developed not to provide institutions comparable to the modernlex mercatoria, but rather to supply physical security. The development of nonsimultaneous exchange was made possible predominantly by the emergence of urban autonomy and urban law applicable to all merchants trading within town, so it appears that the importance of universally accepted commercial institutions in the Middle Ages has hitherto been vastly overrated.
An Equilibrium Theory of Wage and Employment Cyclicality by Gender and by Industry
Authors: Shin Donggyun
Published: July 2021

This paper presents an equilibrium theory that accounts for how cyclical patterns of employment and real wages vary between genders and across industries. Workers' self‐selection of industrial sectors, gender differences in comparative advantage among sectors, sector‐nonneutral shocks, and resulting mobility of workers across sectors play the key roles in explaining wage and employment cyclicality by gender and by industry. Numerical simulations demonstrate that reasonable parameter values exist under which the current model accords with several stylized facts. These parameter values are characterized most importantly by men's comparative advantage in the sector subject to larger cyclical demand shocks.
Training, Wages, and the Human Capital Model
Authors: Veum Jonathan R.
Published: July 2021

Using recent data from the National Longitudinal Survey of Youth, this study examines the predictions of the human capital model concerning the relationship between training, starting wages, and wage growth. As implied by the model, training, particularly employer‐financed training, is positively related to wage growth. Company‐financed training also appears to be portable across jobs or to have a general component. In addition, there is some evidence that workers pay for initial training through a reduced starting wage. The results provide partial support for the human capital model.
Minimum Wages, On‐the‐Job Training, and Wage Growth
Authors: Grossberg Adam J. , Sicilian Paul
Published: July 2021

Using data from the Employment Opportunities Pilot Project, we examine the relationships between minimum wages, wage growth, and on‐the‐job training. We find that minimum wage jobs exhibit less wage growth than other jobs, particularly for men. We find no evidence, however, of a unique minimum wage effect on training opportunities. We conclude that indirect methods of proxying training with wage growth can be misleading as they fail to distinguish whether the reduced wage growth of workers on minimum wage jobs results from their receiving less training than other workers or whether it is strictly a result of the wage determination process.
Teaching Economics with Classroom Experiments: A Symposium
Authors: Holt Charles A.
Published: July 2021

Classroom experiments are effective because students are placed directly into the economic environments being studied. The papers in this special section span diverse applications, for example, speculation and multiple markets, coordination and voting games, and a simple macroeconomy. All experiments can be run with simple props, such as ordinary playing cards. After participating, students bring firsthand experience to the discussion to enhance the effectiveness of the Socratic method. In small classes, these exercises also enable bright undergraduates to run the experiments on their own classmates and to lead the ensuing discussions, creating a special teaching/learning environment.
Agendas and Strategic Voting
Authors: Holt Charles A. , Anderson Lisa R.
Published: July 2021

This paper describes a simple classroom experiment in which students decide which projects to fund on the basis of majority voting. Several agendas are used to generate a voting cycle and an inefficiently high level of public spending. Classroom discussion allows students to discover for themselves how to manipulate outcomes through agenda design and strategic voting. The exercise leads naturally to a discussion of political institutions and the size of government.

Use: This experiment can be used in introductory and public economics classes to teach concepts of voting cycles and inefficiencies in public choice.

Time required: Twenty minutes for reading instructions and taking votes and 15 minutes for discussion.

Materials: A printout of the instructions for each participant and one deck of ordinary playing cards for each group of seven voters.
Coordination
Authors: Capra C. Monica , Holt Charles A.
Published: July 2021

Many economic games have multiple equilibria, some of which are better than others for everyone involved. Such coordination games are of special interest to economists because they raise the possibility that a group of individuals or even a whole economy might become mired in an unfavorable situation. This paper explains how to use playing cards in the classroom to implement an economic game with multiple, Pareto‐ranked equilibria. Discussion can focus on policies and institutions that promote coordination on better outcomes.

Use: This experiment can be used in introductory economics to teach concepts of team production and coordination and in intermediate microeconomics to teach game‐theoretic concepts of Nash equilibrium and Pareto optimality.

Time required: Five minutes for reading instructions, 20 minutes for decision making, and about 15 minutes for discussion.

Materials: You will need one or more decks of playing cards, each deck accommodating 26 people. One copy of the instructions should be made for each person. Payment to a randomly selected individual is optional and will require about a dollar or two.
Broadcast Advertising and U.S. Demand for Alcoholic Beverages
Authors: Nelson Jon P.
Published: July 2021

Quarterly data for 1977‐1994 on alcohol consumption and advertising are used to estimate a differential demand system, including explanatory variables for broadcast advertising and print advertising. The model explains the growth rate of per capita consumption dependent on explanatory variables for prices, real income, demographic changes, and real advertising by media and beverage. Empirical results also are reported for total consumption of pure alcohol. The results for the three beverages and total alcohol indicate that advertising has little or no effect on demand. The empirical evidence thus supports the notion that regardless of media, advertising affects mainly brand shares.
The Impact of Regulation on Technical Change
Authors: Granderson Gerald
Published: July 2021

This paper examines the impact of regulation on a firm's choice of innovations and on the rate of technical change. Using a 1977‐1987 panel of 20 U.S. interstate natural gas pipeline companies, I find that regulation led firms to adopt a technology that augmented (i) noncapital more than capital and (ii) noncapital more than the technology the standard (unregulated) firm would have adopted. I also find that, while technical regress occurred over the sample period, regulation led to a small decline in the rate of technical change and a small increase in production cost on average.
The Austrian Search for Realistic Foundations
Authors: Caplan Bryan
Published: July 2021

Self‐designated Austrian economists have two different views of modern neoclassical economics. Some, such as F. A. Hayek, take issue with certain aspects of neoclassical economics without disputing its fundamentals. Others, most notably Ludwig von Mises and Murray Rothbard, explicitly reject the foundations of neoclassical consumer and welfare theory and construct a systematic alternative. This paper analyzes the most distinctive features of the Mises‐Rothbard alternative to the neoclassical paradigm; it also considers related positions defended by Israel Kirzner. I argue that their effort to rebuild economics on nonneoclassical foundations fails and that their critique of neoclassical foundations is wrong or strongly overstated.
Persistence in International Inflation Rates
Authors: Baum Christopher F. , Barkoulas John T. , Caglayan Mustafa
Published: July 2021

We test for fractional dynamics in inflation rates based on the consumer price index (CPI) for 27 countries and inflation rates based on the wholesale price index (WPI) for 22 countries. The fractional differencing parameter is estimated using semiparametric and approximate maximum likelihood methods. Significant evidence of fractional dynamics with long‐memory features is found in both CPI‐ and WPI‐based inflation rates for industrial as well as developing countries. Implications of the findings are considered, and sources of long memory are hypothesized.
Mitigating Agency Problems by Advertising, with Special Reference to Managed Health Care
Authors: Rubin Paul H. , Schrag Joel L.
Published: July 2021

An agency conflict arises when consumers rely on middlemen for product recommendations. Although consumers want the middlemen to recommend the most suitable product, the middlemen may earn a higher profit if the consumer buys another product. One setting where this conflict arises is the managed health care market. Managed health care providers have an incentive to spend too little on prescription drugs. We investigate whether pharmaceutical manufacturers can use advertising to mitigate this agency conflict. Although advertising may induce health care providers to offer socially efficient medications, drug companies may not choose the socially efficient level of advertising. It will also pay for drug companies to inform consumers if they will not benefit from some drug, as this will increase the price that those who will benefit will be willing to pay.
International Trade and the Accumulation of Human Capital
Authors: Owen Ann L.
Published: July 2021

Changes in the terms of trade affect both the incentives and the ability of individuals to purchase education in a credit‐constrained economy. A model is developed that shows how individual decision‐making is affected in a small economy when it opens up to trade. Empirical results indicate that credit constraints are an important factor influencing school enrollment rates, particularly in low income countries. As a result, countries with low human capital stocks tend to increase their accumulation of human capital with increased trade. The response in high income countries is more muted.
Exchange Rate Volatility and International Trade
Authors: Broil Udo , Eckwert Bernhard
Published: July 2021

The purpose of this note is to show that a positive effect of exchange rate volatility on export production has a theoretical basis. The key to this claim is that, as the exchange rate volatility increases, so does the value of the real option to export to the world market. Higher volatility increases the potential gains from trade. This may explain part of the mixed empirical findings regarding the effects of exchange rate risk on international trade.
Beer Taxation and Alcohol‐Related Traffic Fatalities
Authors: Mast Brent D. , Benson Bruce L. , Rasmussen David W.
Published: July 2021

Most studies of alcohol‐related traffic fatalities find beer taxes to be an important policy variable. This is surprising since beer taxes only have a small impact on consumption and heavy drinkers are the least responsive to prices. This study shows that the tax relationship is not robust across data periods and that it reflects missing variable biases. While lack of control for law enforcement effort does not appear to bias tax coefficients, failure to include determinants of alcohol consumption other than taxes and drinking age and/or factors that simultaneously determine drinking behavior and political support for alcohol taxes apparently do.
Who Loses HOPE? Attrition from Georgia's College Scholarship Program
Authors: Dee Thomas S. , Jackson Linda A.
Published: July 2021

Georgia's lottery‐funded HOPE Scholarship program provides free tuition to in‐state students who can maintain a B average at state universities. However, roughly half of HOPE Scholars lose their support after their freshman year. This study employs student‐level administrative data to identify the observed characteristics that systematically relate to scholarship attrition. Conditional on measures of student ability, there are not statistically significant differences between white, black, and Hispanic students. However, there are dramatic differences across academic disciplines. Students majoring in science, engineering, and computing are 21 to 51 percent more likely to lose their HOPE Scholarships than students in other disciplines.