bluuebunny/crossref_metadata_2025 huggingface dataset:
Bridging the Gap between Locking Compressive Plate, Skin Grafting and Rehabilitation for Tibia Fracture: A Case Report
Authors: Narang Simran , Phansopkar Pratik , Vaidya Laukik , Chitale Neha , Bawiskar Dushyant
Published: July 2021

Introduction: Road traffic accidents (RTA) have remained an ongoing endemic problem over the years and a serious economic and medical-social burden for many countries around the world. Among the most complex and frequent fractures inside the joint is tibial plateau fractures. Such fractures are linked to adverse results, because of reasons such as the damage of cartilage but also soft tissue envelopes, complications like compartment syndrome, postoperative infection, knee dysfunction or rigidity, or even post-traumatic osteoarthritis.

Case Description: An 18-year-old young girl complaining of pain and inability to perform activities of daily living was referred to physiotherapy after being operated with external fixator (LCP) and skin grafting. Locking compressive plate was placed at lateral side of leg with 2 nails near head of fibula and 2 nails near lateral malleolus. Grafted skin was seen at anterior aspect of knee and anterior to medial aspect to leg. Patient was mostly suffering from pain in right leg and knee with intensity 7/10 at rest and 9/10 slight movement and swelling over right lower limb and patient complained of limited mobility and unable to walk.

Discussion: The significance of early mobilisation and range of knee joint motion exercises has been apparent in literature in the past 40 years. From low-intensity activities to progressive strengthening and partial to complete weight with walkers, recovery objectives were devised. Good grafting rates can be achieved with fast ambulation leading low extremity skin grafting operations, which runs counter to conventional lessons in post-operative skin grafting after lower extremity
Community-Acquired Methicillin-Resistant Staphylococcus Aureus an Important Enemy against us; Why Investigation of Their Main Toxins Reveals Contradictory Data
Authors: Alnomasy Sultan F.
Published: July 2021

Community-Acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) strains are serious human pathogens because of their micro floral abilities; resistance to clinically important antibiotics and ability to evade the host immune defences. Panton–Valentine leucocidin (PVL) and Phenol-soluble modulins (PSMs) are the main important virulence factors of CA-MRSA. The aim of this work was to provide an explanation on why there are contradictory findings in studies of PVL and PSMs. Several factors such as differences in growth media or in injection mode, species-specific interaction, contamination in culture supernatants, the concentration of toxin, and exposure time that have an effect on conducting of these studies were discussed in this paper.
Comparison of the dosimetric accuracy of proton breast treatment plans delivered with SGRT and CBCT setups
Authors: MacFarlane Michael J. , Jiang Kai , Mundis Michelle , Nichols Elizabeth , Gopal Arun , Chen Shifeng , Biswal Nrusingh C.
Published: July 2021

Purpose

To compare the dosimetric accuracy of surface‐guided radiation therapy (SGRT) and cone‐beam computed tomography (CBCT) setups in proton breast treatment plans.

Methods

Data from 30 patients were retrospectively analyzed in this IRB‐approved study. Patients were prescribed 4256–5040 cGy in 16–28 fractions. CBCT and AlignRT (SGRT; Vision RT Ltd.) were used for treatment setup during the first three fractions, then daily AlignRT and weekly CBCT thereafter. Each patient underwent a quality assurance CT (QA‐CT) scan midway through the treatment course to assess anatomical and dosimetric changes. To emulate the SGRT and CBCT setups during treatment, the planning CT and QA‐CT images were registered in two ways: (1) by registering the volume within the CTs covered by the CBCT field of view; and (2) by contouring and registering the surface surveyed by the AlignRT system. The original plan was copied onto these two datasets and the dose was recalculated. The clinical treatment volume (CTV): V95%; heart: V25Gy, V15Gy, and mean dose; and ipsilateral lung: V20Gy, V10Gy, and V5Gy, were recorded. Multi and univariate analyses of variance were performed to assess the differences in dose metric values between the planning CT and the SGRT and CBCT setups.

Results

The CTV V95% and lung V20Gy, V10Gy, and V5Gy dose metrics were all significantly (p < 0.01) lower on the QA‐CT in both the CBCT and SGRT setup. The differences were not clinically significant and were, on average, 1.4–1.6% lower for CTV V95% and 1.8%–6.0% lower for the lung dose metrics. When comparing the lung and CTV V95% dose metrics between the CBCT and SGRT setups, no significant difference was observed. This indicates that the SGRT setup provides similar dosimetric accuracy as CBCT.

Conclusion

This study supports the daily use of SGRT systems for the accurate dose delivery of proton breast treatment plans.
Scalable Thermal Masking Technique for Postprocessing of Flexible Electronics
Authors: Kashyap Varun , Mosadegh Bobak , Dunham Simon
Published: July 2021

Flexible electronics have found a wide variety of applications, especially in biomedical engineering, where their intrinsic safety and conformability provide for configurations of sensors and actuators that can accommodate complex anatomies and movement. Current scalable techniques in the manufacture of flexible electronics are limited by the challenges of working with novel, intrinsically stretchable materials, or using cost‐intensive clean room fabrication techniques needed to create strain accommodating geometries. Recently, a technique that allows for scalable postprocessing of flexible printed circuit boards (flex PCBs) to convert them to stretchable configurations is described. Herein, a mechanism for understanding this process based on a thermal masking phenomenon is described. Thermal simulation provides an understanding of the phenomenon and various aspects of the process. Copper traces are modeled along with Kapton insulating layer on ANSYS workbench and a Gaussian waveform is introduced to simulate a laser beam. An inhouse laser cutter is used to calibrate the simulations and an accurate predictive model is used to determine working conditions, resolution, and other parameters that affect the standardized usage of this process for various thicknesses of copper and Kapton that can be produced by most mass manufacturers. This process provides a path for cost‐effective manufacture of stretchable electronics.
Ir(III)‐Catalyzed and Ag2O‐Promoted C−H/C−H Cross‐Coupling/Intramolecular Cyclization of Ketene Dithioacetals with Benzothiophene
Authors: Chen Jinkang , Yin Chuanliu , Zhou Jian , Yu Chuanming
Published: July 2021

A tandem Ir(III)‐catalyzed and Ag2O‐promoted cross‐dehydrogenative coupling (CDC)/ intramolecular cyclization of ketene dithioacetals with benzothiophene derivatives was developed, affording a series of sulfur‐containing cyclization compounds. Mechanistic investigation demonstrated a radical process may be involving intramolecular cyclization. This tandem reaction described herein could be carried out with a broad range of substrates and wide functional group tolerance.

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Maintenance of basic endotracheal intubation skills with direct or video‐assisted laryngoscopy: A randomized crossover follow‐up study in inexperienced operators
Authors: Ghotbaldinian Ehsan , Dehdari Navid , Åkeson Jonas
Published: July 2021

Background

Laryngoscopy is a difficult skill to acquire and maintain and even more so by less frequent users. Numerous studies have compared limitations of direct laryngoscopic (DL) and video‐assisted laryngoscopic (VL) techniques for endotracheal intubation in different scenarios, but individual retention over time of intubation skills with either technique has, to our knowledge, never been reported. The primary aim of this study was to evaluate to what extent recently acquired basic skills of endotracheal intubation, based on DL or VL, are being maintained over time by inexperienced operators.

Methods

This randomized crossover follow‐up study was designed to compare endotracheal intubation with direct (McIntosh blade) versus video‐assisted (hyperangulated blade) laryngoscopy by 20 undergraduate medical students in identical manikins three months after brief basic intubation training with no further intubation practice.

Results

No significant differences in skills retention were found between DL and VL regarding the time for successful intubation or number of adverse events. However, the first intubation was significantly slower regardless of the technique compared with the last one three months earlier. Furthermore, DL was slower and associated with more incidents of esophageal intubation and dental manipulation than was VL.

Conclusions

Although basic intubation skills seem to be similarly well maintained over time regardless of the laryngoscopic technique, endotracheal intubation with VL by inexperienced operators is faster and associated with fewer adverse events than is DL after a three‐month period with no further intubation training.
Development of a continuous evaporation system for an API solution stream prior to crystallization
Authors: Roche Phillip , Jones Roderick C. , Glennon Brian , Donnellan Philip
Published: July 2021

A bubble column was investigated as a method to achieve a desired and controllable rate of evaporation of a pharmaceutical solution. Applying a thermodynamic model to predict the rate of evaporation, all predicted values were observed to have accuracies within the bounds of instrumentation errors (<5% absolute). The developed model accounted for the measured effect of reduced vapor pressure, caused by the dissolved solids as a function of their concentration. A general method to obtain accurate measurement of this effect is introduced and applied, improving the accuracy of model predictions. Consistent and repeatable evaporation rates ranging from 0.7 to 6.9 g/min were achieved experimentally, and errors between predicted rates and observed ranged from 0.219% to 4.19% absolute. This demonstrates a controllable and flexible method for the evaporation of process streams which can be compared to harsher conventional methods such as boiling. The column was configured in a continuous mode and coupled to a downstream crystallizer (MSMPR). Using the column as a controllable concentrator, the concentration of a dilute feed stream of paracetamol in methanol was increased in a single equilibrium stage. The column demonstrated the ability to concentrate the solution in flow by 179%, delivering a flow of 2 ml/min of concentrated liquor to the MSMPR. The MSMPR achieved steady‐state of control, measured by offline dissolved concentration analysis and particle count by FBRM in situ, highlighting the applicablity of the column to perform reliably in a continuous tandem.
Antiaromatic 1,5‐Diaza‐s‐indacenes
Authors: Hanida Kensuke , Kim Jinseok , Fukui Norihito , Tsutsui Yusuke , Seki Shu , Kim Dongho , Shinokubo Hiroshi
Published: July 2021

s‐Indacene is a classical non‐alternant hydrocarbon that contains 12 π‐electrons in a cyclic π‐conjugation system. Herein, we report its nitrogen‐doped analogue, 1,5‐diaza‐s‐indacene. 1,5‐Diaza‐s‐indacenes were readily prepared from commercially available 2,5‐dichlorobenzene‐1,4‐diamine through a two‐step transformation consisting of a palladium‐catalyzed Larock cyclization with diaryl acetylenes followed by hydrogen abstraction. The thus obtained 1,5‐diaza‐s‐indacenes exhibited distinct antiaromaticity, as manifested in clear bond‐length alternation, a forbidden HOMO–LUMO transition, and a paratropic ring current. As compared to the parent s‐indacene, the 1,5‐diaza‐s‐indacenes showed higher electron‐accepting ability owing to the presence of imine‐type nitrogen atoms. The 1,5‐diaza‐s‐indacene core is effectively conjugated with the peripheral aryl groups, which enables fine‐tuning of the absorption spectra and redox properties. The two possible localized forms of 1,5‐diaza‐s‐indacene were compared in terms of their energetic aspects.
Design and synthesis of HFCA‐based plasticizers with asymmetrical alkyl chains for poly(vinyl chloride)
Authors: Hao Yanying , Wang Guyue , Shui Xiaoxue , Tian Anping , Yang Yong , Zhu Jin
Published: July 2021

A series of bio‐based diester plasticizers with various alkyl chain asymmetry and the same molecular weight were designed and synthesized, using renewable 5‐hydroxymethyl‐2‐furancarboxylic acid (HFCA) as the raw material. The chemical structures of the HFCA‐based plasticizers were characterized by Fourier transform infrared and nuclear magnetic resonance (1H NMR and 13C NMR). Besides, the influence of alkyl chain asymmetry on plasticization properties of the HFCA‐based plasticizers in poly(vinyl chloride) (PVC) blends was also investigated. It was found that increasing the alkyl chain asymmetry of the diester plasticizer and keeping the molecular weight unchanged simultaneously could further improve its plasticizing efficiency, without sacrificing its volatility resistance and exudation resistance. The results showed that this study provided a new approach for further optimizing the overall properties of the asymmetric diester plasticizers.
Avoiding High‐Pressure Problem for Modified RNA‐attached Polystyrene Support by Pre‐Swelling Using Toluene in the Oligonucleotide Synthesis
Authors: Kim Sung Won , Cho Yang Il , Jung Kyeong Eun
Published: July 2021

This study describes a method to avoid the high‐pressure problem caused by swelling during the detritylation step in oligonucleotide solid‐phase synthesis using a modified RNA‐attached polystyrene support. The high‐pressure problem originated from the fast flow rate of the reagent and swelling of the solid support was solved by the addition of a pre‐swelling step using toluene before the detritylation step. Through this method, 20‐mer modified RNA/DNA oligonucleotide was synthesized at 3.0 mmol scale without pressure problems with 2′‐methoxy uridine polystyrene support, which has a loading capacity of 354 μmol/g. It was confirmed HPLC purity was improved 1.6% and impurities related to depurination were decreased 0.7% in LC–MS through the application of the pre‐swelling step. This approach has potential additional advantages like shortening detritylation times, hence helping overall cycle time and increasing the support amount in the column which leads to higher throughput.
In‐Fjord Substitution in Expanded Helicenes: Effects of the Insert on the Inversion Barrier and Helical Pitch
Authors: Suárez‐Pantiga Samuel , Redero Pablo , Aniban Xaiza , Simon Martin , Golz Christopher , Mata Ricardo A. , Alcarazo Manuel
Published: July 2021

A series of expanded helicenes of different sizes and shapes incorporating phenyl‐ and biphenyl‐substituents at the deepest part of their fjord have been synthesized via sequential Au‐catalyzed hydroarylation of appropriately designed diynes, and their racemization barriers have been calculated employing electronic structure methods. These show that the overall profile of the inversions (energies, number of transition states and intermediates, and their relative position) is intensively affected by the interplay of steric and attractive London dispersion interactions. Hence, in‐fjord substitution constitutes an additional tool to handle the mechanical properties in helicenes of uncommonly large diameter. The photochemical characterization of the newly prepared helical structures is also reported.
Online‐Partikelmessung im Reingas zu Beginn der kuchenbildenden Staubabscheidung mit Nadelfilzen in der Gasreinigung
Authors: Zhang Qian
Published: July 2021

Die Partikelabscheidung aus Gasen mit filternden Abscheidern lässt sich in zwei Gruppen einteilen: die Tiefen‐ und die Oberflächenfiltration. Ein neues, unbelegtes Filtermedium für die Oberflächenfiltration startet jedoch immer mit einer Tiefenfiltrationsphase im Filtermedium. Die Umwandlung einer Tiefenfiltration in die Oberflächenfiltration geschieht durch eine Clogging‐Phase, in der sich die Filtrationskinetik über einen gewissen Zeitraum ändert. Dieser Beitrag präsentiert theoretische Überlegungen über eine neue Definition für den Beginn der kuchenbildenden Staubabscheidung im Hinblick auf die Partikelabscheidung und eine entsprechende experimentelle Untersuchung mit Nadelfilzen zur Filtrationskinetik zu Beginn der kuchenbildenden Staubabscheidung, die im Sinne der Oberflächenfiltration grundlegende Bedeutung hat.
Chain‐Elongated Ionic Liquid Electrolytes for Low Self‐Discharge All‐Solid‐State Supercapacitors at High Temperature
Authors: Zhao Haibo , Zhang Haitao , Wang Zixing , Jiang Xinglin , Xie Yanting , Xu Zhong , Wang Yuchen , Yang Weiqing
Published: July 2021

High power and good stability enable supercapacitors to work efficiently at high temperatures. However, the high‐temperature‐induced excessive ion transfer of the electrolyte would lead to severe self‐discharge behavior, which has often been overlooked but can be highly detrimental. In this study, solid electrolytes consisting of poly(ethylene oxide) (PEO), bentonite clay, and ionic liquids (IL)‐PEO‐clay@[EMIM][BF4] (PCE), PEO‐clay@[BMIM][BF4] (PCB), and PEO‐clay@[HMIM][BF4] (PCH) lead to dramatic decreases in self‐discharge when used in all‐solid‐state supercapacitors at high temperature of 70 °C, which correlate with chain elongation (i. e., [EMIM+]<[BMIM+]<[HMIM+]). Benefiting from both cation adsorption and high‐temperature stabilization by bentonite clay, PCH‐based supercapacitors (IL=[HMIM][BF4]) deliver an extremely low self‐discharge rate, with only a 30.7 % voltage drop over 10 h at 70 °C (44.5 % for 38 h), which is much lower than that of traditional liquid supercapacitors (63.7 % drop over 10 h at 70 °C). This improvement in high‐temperature self‐discharge behavior is found to be from the decrease in diffusion‐controlled faradaic process. Based on the longer‐chain [HMIM+], soft‐packaged supercapacitors exhibit a low self‐discharge rate and work consistently at 70 °C. This chain‐elongation strategy provides a new possibility for the suppression of self‐discharge behavior in supercapacitors and further aids long‐term energy storage by supercapacitors at high temperatures.
Advanced nonlinear equalizer for Filter Bank Multicarrier‐based Long Reach‐Passive Optical Network system
Authors: L Jerart Julus , D Manimegalai , C Asha Beaula , J Joshan Athanesious , A Andrew Roobert
Published: July 2021

The performance of the intensity‐modulated Filter Bank Multicarrier (FBMC) system using direct detection with advanced nonlinear equalizer in Long Reach‐Passive Optical Network (LR‐PON) is presented in this paper. First, the performance of the FBMC system and its nonlinearity in the channel are analyzed. We introduce two nonlinear equalizers, namely, Artificial Neural Networks–Nonlinear Feed‐Forward Equalizer (ANN‐NFFE) and Deep Neural Network–Nonlinear Equalizer (DNN‐NLE). Both the equalizers can mitigate the nonlinearities in the signal. Also, the impact of the system in downlink is analyzed using simulation by varying the data rates for various fiber lengths. The FBMC using SMT provides better spectral efficiency. The performance of both equalizers is compared. The addition of the DNN‐NLE equalizer provides a better OSNR, good accuracy, and better BER compared with ANN‐NFFE.
Metal Cation‐Modified Graphene Oxide as Precursor for Advanced Materials: Thin Films of Graphene/Prussian Blue Analogues
Authors: Ferreira Caroline Mariano , Ramos Maria Karolina , Zarbin Aldo J. G.
Published: July 2021

This work reports a simple, direct, and easy route to prepare thin films between graphene‐like materials and two hexacyanometallates, based on metal cation modification in graphene oxide (GO) thin films obtained by the liquid/liquid interfacial route. The reaction between GO and Cu2+ or Fe3+ ions in aqueous solution yields GO/Cu2+ or GO/Fe3+, and the nature of the interactions between the GO and the metal cations were demonstrated by FT‐IR. GO/Cu2+ and GO/Fe3+can be chemically reduced to reduced graphene oxide/metal nanoparticles (rGO/Cu or rGO/Fe) thin films. Both GO/metal cation or rGO/metal nanoparticles thin films were used as working electrodes for electrodeposition of their respective hexacyanometallates (Prussian blue, PB, and its copper analogue, Cu‐PBA) based on a heterogeneous reaction between ferricyanide ions in the electrolyte solution and the metallic species in the electrode. The PB and Cu‐PBA formation in all electrodes was confirmed by Raman spectroscopy, X‐ray diffraction, cyclic voltammetry, and scanning electron microscopy, characterized as well‐defined nanometric cubes homogeneously dispersed over the rGO sheets.
Iron Pentazolate Complex: Isoelectronic Species of Ferrocene but with a Planer Structure
Authors: He Xiaohui , Zhang Tiantian , Zhang Quan , Cheng Longjiu , Zhang Jianguo , Wang Kun
Published: July 2021

Energetic pentazolate compound generally releases extremely large energy in the explosion and generates environment‐friendly nitrogen as the main product. Cyclo‐N5− as the mono‐dentate ligand always forms planer structure by σ‐type bonds between center metal cation and ligands in most of the metal pentazolate complexes based on the corresponding XRD results, which is completely different from the well‐known perpendicular structure of ferrocene with the η5‐π‐bonds, although it is known for us that cyclo‐N5− is isoelectronic species of the pentadienide anion C5H5−. In order to understand the differences between the planer Fe(N5)2 and ‘sandwich‐like’ Fe(η5‐C5H5)2, here we design Fe(η5‐N5)2 with η5‐π‐bonds as the possible isomer of the planer Fe(N5)2. Besides the mono‐dentate planer Fe(N5)2, Cyclo‐N5− is possibly as a bidentate ligand to coordinate with Fe2+ to form η2‐σ‐bond. Therefore, the three isomers of Fe(N5)2 and its isoelectronic Fe(η5‐C5H5)2 are compared including their structures of ligands, bonding structures, coordinative pathways and reactivity in the decompositions by applying the DFT and CPMD calculation. The results indicate the formation of σ‐type Fe−N bonds between Fe2+ and mono‐dentate cyclo‐N5− is the most favored.
Spinal beta‐amyloid1‐42 acts as an endogenous analgesic peptide in CCI‐induced neuropathic pain
Authors: Cui Dong , Li Ze‐Hua. , Li Cheng , Qiu Chengjie , Ma Pingchuan , Wu Mingzheng , Song Xue‐Jun
Published: July 2021

Background

The mechanism for reduced pain sensitivity associated with Alzheimer’s disease (AD) has not been illustrated. We hypothesize that amyloid beta 1–42 (Aβ1–42) in the spinal cord acts as an endogenous analgesic peptide to suppress pain induced by nerve injury.

Methods

We used chronic constriction injury of the sciatic nerve (CCI) to produce neuropathic pain in Sprague‐Dawley rats. Enzyme‐linked immunosorbent assay (ELISA) and immunohistochemistry were used to determine the level of Aβ1–42, the expression of Wnt3a/5b and glial activation in the spinal cord. Western blotting was used to determine the expression of interleukins, the phosphorylation of NR2B and ERK1/2, and the nuclear accumulation of transcriptional factors YAP/TAZ. Thermal hyperalgesia and mechanical allodynia were assessed after CCI and pharmacological manipulations through intrathecal administration.

Results

Nerve injury increases spinal level of Aβ1–42, while intrathecal administration of MK‐8931 reduces the level of Aβ1–42 and facilitates mechanical allodynia. Intrathecal administration of Aβ1–42 suppresses pain behaviors in the early and late phases of neuropathy. Spinal administration of Aβ1–42 regulates the expression of interleukins, reducing glial activation and phosphorylation of NR2B and ERK1/2 in the spinal cord of CCI rats. Furthermore, intrathecal administration of Aβ1–42 decreases Wnt5b expression and suppresses the nuclear accumulation of YAP and TAZ. Blocking the interaction between Aβ1–42 and Frizzled receptors by cSP5 reverses the analgesic effects of Aβ1–42.

Conclusions

These findings suggest that spinal Aβ1–42 acts as an endogenous analgesic peptide through regulating cytokines and Wnt pathways. This study may provide a potential target for the development of novel analgesic peptides.

Significance

This study provides an explanation of reduced pain sensitivity associated with Alzheimer’s disease. Furthermore, our findings propose a possible physiological function of beta‐amyloid1–42 to regulate pain. This study may provide a potential target for the development of novel analgesics based on an existing endogenous peptide.
Boronic Acid‐containing Stimuli‐responsive Polymers Modified Nanopores for Label‐free Dual‐signal‐output Detection of Glucose
Authors: Zheng Tingting , Zhu Yujie , Zhu Anwei
Published: July 2021

Herein, a dual‐signal‐output glass nanopore system was developed for sensing glucose. Upon binding glucose, the boronic acid‐containing stimuli‐responsive polymer underwent a wettability switch and pKa shift. When the polymer was immobilized on the inner wall of nanopore, the nanopore offered a sensitive method for evaluating glucose by ion rectification. Besides, due to the electrostatic assembly of cationic pyrene onto the glucose‐bound anionic polymer, the pyrene excimer emission was observed. By separating the substrate binding and fluorescence reporting process, this work avoided the fluorescence labeling of the target and nanopore, thus simplifying the design of dual‐signal‐output nanopore for potential point‐of‐care test.
Condition‐dependent structural collapse in the intrinsically disordered N‐terminal domain of prion protein
Authors: Chen Eric H.‐L. , Lin Kuei‐Ming , Sang Jason C. , Ho Meng‐Ru , Lee Chih‐Hsuan , Shih Orion , Su Chun‐Jen , Yeh Yi‐Qi , Jeng U‐Ser , Chen Rita P.‐Y.
Published: July 2021

Prion protein is composed of a structure‐unsolved N‐terminal domain and a globular C‐terminal domain. Under limited trypsin digestion, mouse recombinant prion protein can be cleaved into two parts at residue Lys105. Here, we termed these two fragments as the N‐domain (sequence 23–105) and the C‐domain (sequence 106–230). In this study, the structural properties of the N‐domain, the C‐domain, and the full‐length protein were explored using small‐angle X‐ray scattering, analytical ultracentrifugation, circular dichroism spectroscopy, and the 8‐anilino‐1‐naphthalenesulfonic acid binding assay. The conformation and size of the prion protein were found to change sensitively under the solvent conditions. The positive residues in the sequence 23–99 of the N‐domain were found to be responsible for the enhanced flexibility with the salt concentration reduced below 5 mM. The C‐domain containing a hydrophobic patch tends to unfold and aggregate during a salt‐induced structural collapse. The N‐domain collapsed together with the C‐domain at pH 5.2, whereas it collapsed independently at pH 4.2. The positively charged cluster (sequence 100–105) in the N‐domain contributed to protecting the exposed hydrophobic surface of the C‐domain.
Expense Preference Behavior and Contract‐Management: Evidence from U.S. Hospitals
Authors: Dor Avi , Duffy Sarah , Wong Herbert
Published: July 2021

This paper reports on a study of expense preference behavior in a conditional sample of hospitals (before and after adoption of contract‐management arrangements) using an extension of Mester's (1989) test. To identify expense preference parameters, input demand equations are considered in addition to the cost function and are estimated jointly with the cost function as a system of nonlinear equations. Based on this test, contract managers do not appear to be cost minimizers, although they tend to exhibit lower expense preference behavior than salaried managers. The importance of our results, however, goes beyond a single industry because we have shown that estimates of expense preference depend critically upon the particular input demand being studied. Studies that hitherto have relied on single input demand equations or on the cost function alone may have to be reinterpreted in this light.
Children as Income‐Producing Assets: The Case of Teen Illegitimacy and Government Transfers
Authors: Clarke George R. G. , Strauss Robert P.
Published: July 2021

This paper develops a classical model of the teen fertility decision in the presence of public income transfers. The theoretical model predicts that welfare payments will encourage fertility, holding constant other economic opportunities, and that better economic opportunities will discourage fertility. Considering the possible simultaneity of illegitimacy rates and benefit levels, due to the collective choice process, we confirm the theoretical model's predictions with state‐level data from 1980 through 1990. We find that including fixed effects in the regression to control for unobserved differences between states does not sufficiently control for endogeneity. After controlling for endogeneity, real welfare benefits are strongly and robustly related to teen illegitimacy. The point estimates of the elasticity with respect to changes in the illegitimacy rate are around +1.3 for white teens and +2.1 for black teens. Real wages for women with a high school education or less are negatively related to teen illegitimacy for white teens, with an elasticity of around ‐0.4. Finally, male wages appear to have little effect on the illegitimacy rate for white teens but appear negatively correlated with the illegitimacy rate for black teens in some model specifications.
Investment During the Great Depression: Uncertainty and the Role of the Smoot‐Hawley Tariff
Authors: Archibald Robert B. , Feldman David H.
Published: July 2021

The political process that led to the Smoot‐Hawley tariff likely generated significant business uncertainty. Recent investment theory suggests that increased cash‐flow uncertainty can depress investment. We use cross‐sectional net investment data to estimate an investment model augmented by two measures of international exposure (imported inputs and export markets). The exposure variables allow us to test whether trade regime uncertainty played a significant macroeconomic role in the early years of the Great Depression. International exposure proves important in explaining investment behavior at the start of the downturn (1929) but not in later years (1930‐1933).
Rational Partisan Theory: Empirical Evidence for the United States
Authors: Carlsen Fredrik
Published: July 2021

This paper presents two tests of the rational partisan theory (RPT) of business cycles. First, I develop and test an RPT model in which wage contracts are staggered and overlapping. Bureau of Labor Statistics (BLS) data on the density and duration of wage contracts and estimates of the incumbent party's election‐win probability are employed to calibrate partisan intervention variables entered in output growth regressions. Next, I perform a more “flexible” test of the RPT by comparing partisan output growth differences after elections in which the outcome was relatively surprising with partisan output growth differences after elections in which the outcome was widely anticipated. The two approaches produce the same conclusion: The RPT is not supported by the data.
Effects of U.S. Trade Remedy Law Enforcement under Uncertainty: The Case of Steel
Authors: Chung Jae W.
Published: July 2021

This paper investigates the impact of U.S. trade remedy law enforcement on import penetration of foreign‐manufactured steel into the U.S. steel market. Given the quasi‐judicial process for implementation of the two provisions relevant to U.S. steel imports, section 701 (countervailing duty) and section 731 (antidumping duty), I derive the probability‐augmented model to be used as the theoretical basis for the research. The results obtained in this paper indicate that the trade remedy policy was effective. However, the elasticity‐measured degree of effectiveness was small.
Instability of Equilibria in Experimental Markets: Upward‐Sloping Demands, Externalities, and Fad‐Like Incentives
Authors: Plott Charles R. , Smith Jared
Published: July 2021

The objective of the paper is to study markets in which the value of the activity to any one person increases with the level with which the activity is undertaken by others. The general interpretation could be fads, mimicking behavior, or some sort of belief formation process in which the beliefs or expectations of agents about some underlying state of nature are influenced by the buying behavior of other agents. The result is to create a market that can be modeled as having an upward‐sloping market demand curve. The questions posed are (i) in the fad‐like environment, does the classical concept of equilibrium (as an equating of market demand and market supply) accurately predict market behavior; (ii) can both stable and unstable equilibria be observed; and (iii) which of the two classical concepts of stability best describes the conditions under which instability is observed? Under the conditions of a fad‐like demand side externality in a market organized by the multiple unit double auction (MUDA), market equilibration occurs at a point where demand equals supply. The disequilibrium behavior follows the dynamics of the Marshallian model of dynamics, as opposed to the Walrasian model. These results confirm and extend the major findings of Plott and George who studied a similar environment with a downward‐sloping supply.
Loan Pushing and Triadic Relations
Authors: Deshpande Ashwini
Published: July 2021

This paper is an attempt to define and explore the phenomenon of loan pushing in international lending in the 1970s. The earliest descriptions of loan pushing are anecdotal; this paper surveys the various facets that emerge from these anecdotes and suggests a possible definition that serves as the basis for a theoretical model. This model, inspired by the confessions of a banker, explores a triadic relationship between a corporation in the lender country, the lender bank, and a borrower in a developing country and suggests that a rational, profit maximizing commercial bank could end up pushing loans on to the borrower. Changes in international commercial banking in the 1970s that facilitated this type of loan pushing are discussed next. To the extent that the loan pushing doctrine is valid, it implies that the commercial banks were at least as responsible for the massive lending boom of the 1970s as the borrowers and should have been made to bear the cost of adjustment as well.
A Positive Model of Reserve Requirements and Interest on Reserves: A Clearinghouse Interpretation of the Federal Reserve System
Authors: Toma Mark
Published: July 2021

This paper develops a positive model of reserve requirements and interest on reserves, based on the observation that Congress exempted the Fed from a legal restriction that had prevented private clearinghouses from issuing their own currency. Eliminating the restriction provided the Fed with a source of revenue that could be used to finance general government outlays and to pay implicit interest on reserves. The model implies that the government's financing requirements help explain reserve requirement movements and that interest rates on reserves vary with market loan rates. Cointegration, error‐correction, and Granger‐causality tests provide supporting evidence.
Input Decisions and Price‐Quality Schedules
Authors: Hennessy David A.
Published: July 2021

Often, a single production process gives rise to a mass distribution of quality levels. If prices vary with quality, then input use is determined by interactions between the production‐quality‐input use relationship and the price‐quality relationship. Using dominance methods, I investigate how price‐quality schedules affect optimal input choices. Integral and differential conditions on changes in schedules are found that, together with conditions on the quality‐conditioned technology, are sufficient to determine changes in the intensity of input use.
A Generalized Distance Function and the Analysis of Production Efficiency
Authors: Chavas Jean‐Paul , Cox Thomas L.
Published: July 2021

A generalization of Shephard's distance functions is proposed, extending the usefulness of distance functions in economic analysis. Applications to efficiency measurements and productivity analysis are presented. New indexes of productivity and technical, allocative, and scale efficiency are proposed and analyzed. Interpretation of these indexes in terms of ray‐average cost, ray‐average revenue, and cost‐to‐revenue ratio is discussed.
Employment Uncertainty and the Incidence of Job Loss in Transition Economies: The Case for Central Europe
Authors: Herzog Henry W.
Published: July 2021

A shared concern among Central European countries is the significant social cost imposed by market‐oriented reforms. Although a growing body of literature has addressed the incidence of such reforms on unemployment distribution and duration, little is known of the actual transitions of workers from employment to unemployment and specifically the dynamics of transition‐induced job loss. This study examines such transitions in the Czech and Slovak Republics, Poland, and Slovenia within econometric models whereby voluntary and involuntary employment separations are jointly determined. In this regard, employment reductions triggered by demand‐driven reforms are accommodated at the industry and the occupation level by redundancies as well as voluntary quits in anticipation of redundancy. In addition, employed workers within the models consider the “costs” of job loss (likelihood of long‐term unemployment) while both shirking, and thus risking dismissal, and contemplating quitting. Estimates on personal characteristic variables in the involuntary and voluntary separation equations provide important new information on the incidence of job loss in Central European transition economies and specifically how such loss likely varies by gender, age, marital status, and completed education. Particular attention is devoted to gender differentials.
The Determinants of Hispanic Representation in Municipal Government
Authors: Sass Tim R.
Published: July 2021

In recent years Voting Rights Act cases brought by Hispanic litigants challenging local election systems have proliferated. This article analyzes the effects of election systems and demographic factors on the electoral success of Hispanics in municipal elections. Ability to speak English well and educational attainment of non‐Hispanics are important factors that boost Hispanic representation. On average district elections enhance Hispanic representation, though the impact of district elections varies directly with the level of residential segregation. Although some Blacks may support Hispanic candidates, I do not find any significant effects of increases in Black population on the electoral success of Hispanics.
Pricing Liquid Petroleum Gas in Mexico
Authors: Brito Dagobert L. , Littlejohn William Laney , Rosellón Juan
Published: July 2021

This paper considers the regulation of pricing of liquid petroleum gas in Mexico. We construct a model that incorporates all information essential to the pricing question and derive relationships that should hold between prices in Mexico and prices in world markets. Prices in Mexico can be tied to the readily observable prices in the United States by a netback rule. However, this rule can lead to incentives to increase the price of domestic liquid petroleum gas by diverting production from the regulated market.
Committee Decision Making: The Multicategory Case
Authors: Britto Ronald
Published: July 2021

If a committee of n members is asked to make a decision to accept or reject a proposal and each committee member summarizes his/her assessment of the proposal by selecting one of several options (like “highly recommend,” “recommend,” etc.), how are these to be aggregated so as to come up with an overall recommendation? I show, on the assumption that the judgements of the individual committee members are statistically independent, that this is to be done by weighting the numbers of members selecting each option by some suitable weights; if the resulting number is larger than some benchmark number, the proposal is accepted, and otherwise rejected.
Exploring Economic Models Using Excel
Authors: Cahill Miles , Kosicki George
Published: July 2021

This paper applies spreadsheet software to intermediate‐level consumer theory concepts. Spreadsheets help make the concepts more accessible while allowing students to explore the ideas in more depth. Areas of application are utility functions, income and substitution effects, price indices, measures of welfare change, and the optimal saving rate. We chose the examples to stimulate awareness and discussion of the many classroom uses for four important Excel spreadsheet tools: three‐dimensional (3‐D) graphs, iteration, Goal Seek, and Solver.
Reserve Banks, the Discount Rate Recommendation, and FOMC Policy
Authors: Tootell Geoffrey M. B.
Published: July 2021

In the United States, private citizens play little direct role in policymaking. The directors of the boards of the regional Federal Reserve banks are an apparent exception to this rule. These directors recommend changes in the discount rate, although the Board of Governors decides whether to act on the recommendations. These directors would have greater influence if they affected the FOMC votes of their district bank presidents. This paper shows that the FOMC votes of the regional bank presidents are strongly correlated with the discount rate recommendation of their bank's board. Several alternative explanations for the correlation are then examined.
Right‐to‐Work Laws: New Evidence from the Stock Market
Authors: Abraham Steven E. , Voost Paula B.
Published: July 2021

This article is an empirical examination of whether or not stockholder wealth rises in response to passage of a right‐to‐work law—a state law banning union security clauses from collective bargaining agreements. Stockholder wealth rose when Louisiana passed such a law in 1976 and when Idaho did so in 1985‐1986. Presumably this occurred because investors anticipated higher future profits with weaker labor unions or a lower probability of future organization. This is new evidence that such laws are more than symbolic: They hamper labor unions.
Do Business Cycles Affect State Appropriations to Higher Education?
Authors: Humphreys Brad R.
Published: July 2021

Spending on higher education constitutes an important and increasing portion of state government spending and a major source of operating funds at public institutions of higher education. Anecdotal evidence suggests that state appropriations are subject to cyclical variation. An analysis of state appropriations to higher education, enrollment in two‐ and four‐year public colleges and universities, and state‐specific measures of the business cycle for all 50 states over the period 1969‐1994 shows that state appropriations to higher education are highly sensitive to changes in the business cycle. A 1% change in real per capita income was, on average, associated with a 1.39% change in real state appropriations per full‐time equivalent student enrolled. This implied decline in state government funding, coupled with the increase in enrollment in higher education during recessions reported by Betts and McFarland (1995), suggest that public institutions of higher education may experience fiscal stress during economic downturns. These results also suggest that state legislators and education policymakers should reconsider their higher education funding policies during recessions in order to allow public colleges and universities to provide dislocated workers with access to quality education and training during these periods.
Decentralization and Transfer Pricing Under Oligopoly
Authors: Zhao Laixun
Published: July 2021

This paper presents a simple model of a partially decentralized multinational firm (MNF) in competition with a rival firm. It is shown that transfer pricing can be used as a rent‐shifting device by the MNF to compete with the rival. This arises because the MNF headquarters uses the transfer price to manage different subsidiaries. The specific value of the transfer price chosen by the MNF depends on whether the rival firm produces the intermediate good, the final good, or both and whether the rival is integrated or not. In particular, both decentralization and competition with a fully integrated rival result in lower transfer prices.
Minimum Wages and the Card‐Krueger Paradox
Authors: Shepherd A. Ross
Published: July 2021

An apparent paradox perceived by Card and Krueger concerning the relationship between minimum wages, employment, and output prices is resolved by revisiting the economics of minimum wages to show that under monopsonistic conditions in the labor market and competitive price‐taking in the market for output, increases in both firm‐level and industry employment are compatible with increases in output prices.
On the Fairness Literature: Comment
Authors: Berliant Marcus , Dunz Karl , Thomson William
Published: July 2021

We offer a guide to the recent literature on the problem of fair allocation, and we present various concepts that have been developed in this literature and the various economic environments in the context of which they have been analyzed.
Network Externalities and the Overprovision of Quality by a Monopolist
Authors: Lambertini Luca , Orsini Raimondello
Published: July 2021

We investigate the behavior of a monopolist supplying a vertically differentiated good with network externalities. Assuming a convex unit cost of quality improvements, we show that the presence of network externalities may yield oversupply of quality compared with the social optimum, when partial market coverage emerges at equilibrium. Overall, the incentive to expand output increases in the extent of network externalities, thereby partially counterbalancing the social damage produced by the quality distortion.
Alcohol Availability and Crime: Evidence from Census Tract Data
Authors: Gyimah‐Brempong Kwabena
Published: July 2021

Using census tract data from the city of Detroit and a reduced‐form crime equation, this article finds that alcohol availability is positively and significantly related to total, property, and violent crime rates and homicides. The elasticity of crime rates with respect to alcohol availability calculated in this study are 0.92, 0.82, 0.87, and 0.12 for total crime, violent crime, property crime, and homicide, respectively. These elasticities do not change qualitatively across estimation methods for the various measures of crime rates. I find that ordinary least squares estimates impart a downward bias to the effects alcohol availability has on crime rates. Failure to account for the endogeneity of alcohol outlets will therefore result in an underestimate of crime elasticities with respect to alcohol availability. The estimates imply that reducing alcohol availability may decrease crime rates and improve social welfare.
Injury‐Based Protection with Auditing under Imperfect Information
Authors: Kohler Philippe , Moore Michael O.
Published: July 2021

We analyze optimal protection when a benevolent government must maintain nonnegative domestic profits and when the domestic import‐competing firm has private information about its costs. A costly audit mechanism can deter strategic manipulation of this private information. We show that a high penalty/low probability of investigation is optimal when the shadow price of the firm profit is low compared with the audit cost. A low penalty/high probability of investigation is optimal when there is a low investigation cost and a high shadow price of firm profit. In this latter case, the trade authority obtains truthful announcements by directly auditing the firm.