bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoasymmetric Synthesis of [Co(edta)]− from Co(II) Salt and L4edta (L=H+ or Na+), Using a Chiral Cu(I) Complex
Authors: Sakaki Shigeyoshi , Horita Rikihisa , Kuraki Koichi , Hamada Taisuke
Published: September 2003

[Co(edta)]− was photochemically synthesized from CoX2 (X=NO3− or OAc−) and L4edta (L=H+ or Na+) with a chiral Cu(I) complex, under irradiation of near UV light (350–370 nm). Λ–[Co(edta)]− was produced in excess (7% e.e.) from Co(OAc)2 and H4edta, while Δ–[Co(edta)]− was produced in excess (7% e.e.) from Co(OAc)2 and Na4edta. When Co(NO3)2 was used, Λ–[Co(edta)]− was yielded from either H4edta or Na4edta.
New Aspect of Methanesulfonyl Chloride: Unusual Deoxygenations of Pyridine N-Oxides with methanesulfonyl Chloride and Triethylamine
Authors: Morimoto Yoshiki , Kurihara Hajime , Yokoe Chiho , Kinoshita Takamasa
Published: September 2003

Treatment of several pyridine N-oxides with an excess of methanesulfonyl chloride and triethylamine brought about a deoxygenation reaction to give efficiently the corresponding reduction products without chlorination of the pyridine nucleus.
Determination of Relative and Absolute Stereochemistry of Cephalosporolide D and Its Enantioselective Total Synthesis
Authors: Shiina Isamu , Fukuda Yoshio , Ishii Toshihiro , Fujisawa Hidehiko , Mukaiyama Teruaki
Published: September 2003

An efficient method for the synthesis of (−)-cephalosporolide D was established via successive enantioselective aldol reaction and effective construction of 8-membered ring lactone moiety.
Calix[4]arene Derivative Bearing π-Coordinate Substituents as Neutral Carrier for Silver Ion Sensors
Authors: Kimura Keiichi , Tatsumi Kenta , Yajima Setsuko , Miyake Saori , Sakamoto Hidefumi , Yokoyama Masaaki
Published: September 2003

Calix[4]arene tetra(allyl ether) 1 was applied as a neutral carrier of silver ion sensors, which exhibited an excellent silver ion selectivity against sodium ion, while calix[4]arene tetra(allyl ester) 2 possesses only poor silver ion selectivity with severe sodium ion interference.
Synthesis and Anion Binding Ability of Metacyclophane-Based Cyclic Thioureas
Authors: Tobe Yoshito , Sasaki Shin-ichi , Mizuno Masaaki , Naemura Koichiro
Published: September 2003

Cyclophanes having two thiourea groups were synthesized and their anion binding ability was examined by titration method using 1H-NMR spectroscopy. Strong and selective anion binding of the preorganized cyclic receptors was observed in the general order of H2PO4− > CH3COO− > Cl− > HSO4− > Br−.
Epoxidation of Olefins with H2O2 Catalyzed by an Electronegatively-Substituted Iron Porphyrin Complex in Aprotic Solvent
Authors: Lee Yoon Jung , Goh Yeong Mee , Han So-Yeop , Kim Cheal , Nam Wonwoo
Published: September 2003

Catalytic epoxidation of olefins by hydrogen peroxide in the presence of an electronegatively-substituted iron porphyrin complex yielded epoxide products in acetonitrile solution. An iron(III) hydroperoxide porphyrin complex was proposed as a reactive intermediate responsible for the olefin epoxidations.
Compressibility and Volume Changes of Lysozyme due to Inhibitor Binding
Authors: Gekko Kunihiko , Yamagami Keigo
Published: September 2003

The adiabatic compressibility and partial specific volume of hen egg-white lysozyme, which were determined by the sound velocity and density measurements at 25 °C, decreased by addition of its inhibitors, N-acetyl-D-glucosamine oligomers, in the order of monomer > dimer > trimer. This result demonstrates that the inhibitor binding induces the atomic packing in the cleft of the active site to diminish the structural fluctuation of the protein.
Oxygen Reduction Characteristics on Pyrolytic Graphite Electrodes Modified with Electro-polymerized Salen Compounds
Authors: Okada Tatsuhiro , Katou Kihoko , Hirose Takuji , Yuasa Makoto , Sekine Isao
Published: September 2003

Electro-polymerized cobalt salen compounds on pyrolytic graphite electrodes were first tested as oxygen reduction catalysts in aqueous solutions of various pH. From electrochemical measurements it was revealed that although in acidic media the catalyst performance deteriorated, the performance in neutral and basic media was relatively good as compared to that of platinum, the best catalyst for this reaction.
Mechanism and Potential Energy Surface for Photoisomerization of Stilbene in Zeolite Nanospace
Authors: Kuriyama Yasunao , Takeya Haruhiko , Oishi Shigero , Kojima Masanobu
Published: September 2003

The photoisomerization of cis- and trans-stilbenes adsorbed in zeolite supercage was studied by means of Raman spectroscopy for in situ analysis of the isomer ratio in the photostationary state. It was found that the isomerization proceeds mainly through the singlet excited states for NaY and triplet excited states for KY, and also a new potential energy surface for the photoisomerization was proposed.
4,4′-(Trimethylene)bis(2,6-di-t-butylphenoxy) Diradical: An Application of the Sequential Redox-Solid State Photolysis (SRSSP) Method
Authors: Nakatuji Koji , Oda Masaji , Kozaki Masatoshi , Morimoto Yoshiki , Okada Keiji
Published: September 2003

The oxidation of 4,4′-(trimethylene)bis(2,6-di-t-butylphenol) with lead dioxide underwent intramolecular cyclization at the 4,4′-positions to give a dispiro-compound. Irradiation of the dispiro-compound in a methylcyclohexane matrix at −150 °C produced 4,4′-(trimethylene)bis(2,6-di-t-butylphenoxy) diradical which has a stable triplet state.
Helical Stereoregular Artificial Glycoconjugate Polymers Based on Poly(phenylacetylene) Backbone: Synthesis and Molecular Recognition with Lectin
Authors: Matsuura Kazunori , Furuno Shin-ichi , Kobayashi Kazukiyo
Published: September 2003

Stereoregular poly(phenylacetylene)s bearing pendant lactose and cellobiose moiety were synthesized by polymerization of β-N-glycosylated 4-ethynylbenzamides with [Rh(nbd)Cl]2 (nbd=norbornadiene) as initiator. The glycoconjugate polymer possessed alternating double bond backbone with cis-transoidal regioregularity and helical conformation. Inhibition assay of hemagglutination revealed that galactose-specific lectin efficiently bound to the stereoregular helical glycopolymer bearing lactose, but the binding was not so strong as that of the corresponding flexible glycoconjugate polystyrene.
In Situ Infrared Spectroscopic Studies of Adsorption of Lactic Acid and Related Compounds on the TiO2 and CdS Semiconductor Photocatalyst Surfaces from Aqueous Solutions
Authors: Awatani Tadashi , Dobson Kevin D , McQuillan A James , Ohtani Bunsho , Uosaki Kohei
Published: September 2003

In situ attenuated total reflectance infrared (ATR-IR) spectroscopy has been used to determine the structure of adsorbed lactic acid (LA) compounds on the surfaces of titanium dioxide (TiO2) and cadmium sulfide (CdS) photocatalysts. LA was found to chelate onto the TiO2 in a b identate fashion, while in the CdS case, LA was adsorbed electrostatically as the lactate ion. These differing surface interactions are likely to determine the selectivity in the photo-products of LA.
Optically Active Tetrapyrazinoporphyrazines and Their Circular Dichroism in Monomeric and Dimeric Forms
Authors: Kobayashi Nagao , Nevin W Andrew
Published: September 2003

Metal-free and copper derivatives of tetrapyrazinoporphyrazines containing four (1R)-(−)- or (1S)-(+)-camphor units have been synthesized and their circular dichroism (CD) has been studied: in monomeric state, R and S isomers showed mainly positive and negative CD signs, respectively, while CD pattern in a cofacial dimeric state suggested that R and S isomers stack in left- and right-handed helix, respectively.
Change in Activity of Alumina by Calcination Temperature for Selective Reduction of Nitrogen Monoxide with Ethene in Excess Oxygen
Authors: Okazaki Noriyasu , Okuda Yukie , Yamamoto Yoshitaka , Tada Akio
Published: September 2003

Mostly, the activities for NO+C2H4+O2 and its related reactions decreased with increasing calcination temperature. In NO2+C2H4, N2 was selectively formed over alumina calcined at 800 °C, while over alumina calcined at the other temperatures, not only N2 but also NO was formed. Taking into account the temperature window as well, the most advantageous calcination temperature of alumina is 800 °C as a catalyst for NO+C2H4+O2.
Detection of Zinc(II) Ion by Using Self-Oscillation of the Electrical Potential across the Water-Oil-Water Liquid Membrane
Authors: Yoshidome Toshifumi , Higashi Toshifumi , Mitsushio Masaru , Kamata Satsuo
Published: September 2003

Oscillation of an electrical potential across a water-oil-water liquid membrane was measured in the presence of metal ion in one of the aqueous phases and a ligand in the organic phase, which likely forms a complex with Zn2+. By use of the formation of the complex around the interface, Zn2+ was detected through the measurement of the oscillation mode.
Photodegradation of Malachite Green in the Presence of Fe3+/H2O2 under Visible Irradiation
Authors: Wu Kaique , Zhang Tianyong , Zhao Jincai , Hidaka Hisao
Published: September 2003

The photodegradation of malachite green (MG) in the presence of Fe3+ and H2O2 under visible light irradiation (λ > 450 nm) is reported in comparison with that in the dark. It was found that the visible irradiation can accelerate significantly the Fenton degradation of dyes, which provides possibly a preferable approach for the treatment of dye pollutants in wastewater.
Photochemical Generation of Nitric Oxide from 3,4-Bis-2′-chlorophenylfuroxan
Authors: Hwang Kwang-Jin , Kim Sung Ki , Shim Sang Chul
Published: September 2003

Photolysis of 3,4-bis-2′-chlorophenylfuroxan generated nitric oxide and bis-2-chlorophenylacetylene in 17% yield. This is the first example of the photochemical generation of the nitric oxide from the furoxan.
Two-dimensional Molecular Motions of Guanidinium Ions Confined in the Interlayer Space of Tetrasilicicfluormica
Authors: Yamauchi Miho , Ishimaru Shin’ichi , Ikeda Ryuichi
Published: September 2003

Dynamic behavior of guanidinium ions with the planar structure in the two-dimensional interlayer space of tetrasilicicfluormica was investigated by the solid NMR method. Above 300 K, guanidinium ions were found to perform the two-dimensional self-diffusion with their molecular plane parallel to the clay layers.
The Misallocation of Housing Under Rent Control
Authors: Glaeser Edward L , Luttmer Erzo F. P
Published: September 2003

The standard analysis of price controls assumes that goods are efficiently allocated, even when there are shortages. But if shortages mean that goods are randomly allocated across the consumers that want them, the welfare costs from misallocation may be greater than the undersupply costs. We develop a framework to empirically test for misallocation. The methodology compares consumption patterns for demographic subgroups in rent-controlled and free-market places. We find that in New York City, which is rent-controlled, an economically and statistically significant fraction of apartments appears to be misallocated across demographic subgroups.
Social Security Investment in Equities
Authors: Diamond Peter , Geanakoplos John
Published: September 2003

This paper explores the general-equilibrium impact of social security portfolio diversification into private securities, either through the trust fund or private accounts. The analysis depends critically on heterogeneities in saving, production, assets, and taxes. Limited diversification weakly increases interest rates, reduces the expected return on short-term investment (and the equity premium), decreases safe investment, increases risky investment, and increases a suitably weighted social welfare function. However, the effects on aggregate investment, long-term capital values, and the utility of young savers hinges on assumptions about technology. Aggregate investment and long-term asset values can move in opposite directions.
On the Evolution of the Firm Size Distribution: Facts and Theory
Authors: Cabral Luís M. B , Mata José
Published: September 2003

Using a comprehensive data set of Portuguese manufacturing firms, we show that the firm size distribution is significantly right-skewed, evolving over time toward a lognormal distribution. We also show that selection accounts for very little of this evolution. Instead, we propose a simple theory based on financing constraints. A calibrated version of our model does a good job at explaining the evolution of the firm size distribution.
Inequality and Growth: Why Differential Fertility Matters
Authors: de la Croix David , Doepke Matthias
Published: September 2003

We develop a new theoretical link between inequality and growth. In our model, fertility and education decisions are interdependent. Poor parents decide to have many children and invest little in education. A mean-preserving spread in the income distribution increases the fertility differential between the rich and the poor, which implies that more weight gets placed on families who provide little education. Consequently, an increase in inequality lowers average education and, therefore, growth. We find that this fertility-differential effect accounts for most of the empirical relationship between inequality and growth.
Interpreting Aggregate Wage Growth: The Role of Labor Market Participation
Authors: Blundell Richard , Reed Howard , Stoker Thomas M
Published: September 2003

A new and easily implementable framework for the empirical analysis of the relationship between aggregate and individual wages is developed. Aggregate real wages are shown to contain three important bias terms: one associated with the dispersion of individual wages, a second deriving from compositional changes in the (selected) sample of workers, and a third reflecting the distribution of working hours. Their importance for interpreting the path of aggregate wages and of the returns to education for recent experience in Britain is highlighted. A close correspondence between the estimated biases and the patterns of differences shown by aggregate wages is established.
Can Mandated Political Representation Increase Policy Influence for Disadvantaged Minorities? Theory and Evidence from India
Authors: Pande Rohini
Published: September 2003

A basic premise of representative democracy is that all those subject to policy should have a voice in its making. However, policies enacted by electorally accountable governments often fail to reflect the interests of disadvantaged minorities. This paper exploits the institutional features of political reservation, as practiced in Indian states, to examine the role of mandated political representation in providing disadvantaged groups influence over policy-making. I find that political reservation has increased transfers to groups which benefit from the mandate. This finding also suggests that complete policy commitment may be absent in democracies, as is found in this case.
Are Mergers Beneficial to Consumers? Evidence from the Market for Bank Deposits
Authors: Focarelli Dario , Panetta Fabio
Published: September 2003

The general conclusion of the empirical literature is that in-market consolidation generates adverse price changes, harming consumers. Previous studies, however, look only at the short-run pricing impact of consolidation, ignoring effects that take longer to materialize. Using a database that includes detailed information on the deposit rates of individual banks in local markets for different categories of depositors, we investigate the long-run price effects of mergers. We find strong evidence that, although consolidation does generate adverse price changes, these are temporary. In the long run, efficiency gains dominate over the market power effect, leading to more favorable prices for consumers.
To Float or to Fix: Evidence on the Impact of Exchange Rate Regimes on Growth
Authors: Levy-Yeyati Eduardo , Sturzenegger Federico
Published: September 2003

We study the relationship between exchange rate regimes and economic growth for a sample of 183 countries over the post-Bretton Woods period, using a new de facto classification of regimes based on the actual behavior of the relevant macroeconomic variables. In contrast with previous studies, we find that, for developing countries, less flexible exchange rate regimes are associated with slower growth, as well as with greater output volatility. For industrial countries, regimes do not appear to have any significant impact on growth. The results are robust to endogeneity corrections and a number of alternative specifications borrowed from the growth literature.
Network Effects, Congestion Externalities, and Air Traffic Delays: Or Why Not All Delays Are Evil
Authors: Mayer Christopher , Sinai Todd
Published: September 2003

We examine two factors that explain air traffic congestion: network benefits due to hubbing and congestion externalities. While both factors impact congestion, we find that the hubbing effect dominates empirically. Hub carriers incur most of the additional travel time from hubbing, primarily because they cluster their flights in short time spans to provide passengers as many potential connections as possible with a minimum of waiting time. Non-hub flights at the same hub airports operate with minimal additional travel time. These results suggest that an optimal congestion tax might have a relatively small impact on flight patterns at hub airports.
International Business Cycles: World, Region, and Country-Specific Factors
Authors: Kose M. Ayhan , Otrok Christopher , Whiteman Charles H
Published: September 2003

The paper investigates the common dynamic properties of business-cycle fluctuations across countries, regions, and the world. We employ a Bayesian dynamic latent factor model to estimate common components in macroeconomic aggregates (output, consumption, and investment) in a 60-country sample covering seven regions of the world. The results indicate that a common world factor is an important source of volatility for aggregates in most countries, providing evidence for a world business cycle. We find that region-specific factors play only a minor role in explaining fluctuations in economic activity. We also document similarities and differences across regions, countries, and aggregates.
Technological Change and the Stock Market
Authors: Laitner John , Stolyarov Dmitriy
Published: September 2003

Tobin's average q has usually been well above 1, but fell below 1 during 1974 – 1984. Our model explains this pattern and reconciles it with unchanging aggregate investment. The stock market value in the numerator of q reflects ownership of physical capital and knowledge, but the denominator measures just physical capital. Therefore, q is usually above 1. Periodic arrivals of important new technologies, such as the microprocessor in the 1970's, suddenly render old knowledge and capital obsolete, causing the stock market to drop. National accounts measures of physical capital miss this rapid obsolescence. Then q appears to drop below 1.
Plants and Productivity in International Trade
Authors: Bernard Andrew B , Eaton Jonathan , Jensen J. Bradford , Kortum Samuel
Published: September 2003

We reconcile trade theory with plant-level export behavior, extending the Ricardian model to accommodate many countries, geographic barriers, and imperfect competition. Our model captures qualitatively basic facts about U.S. plants: (i) productivity dispersion, (ii) higher productivity among exporters, (iii) the small fraction who export, (iv) the small fraction earned from exports among exporting plants, and (v) the size advantage of exporters. Fitting the model to bilateral trade among the United States and 46 major trade partners, we examine the impact of globalization and dollar appreciation on productivity, plant entry and exit, and labor turnover in U.S. manufacturing.
The Economic Significance of National Border Effects
Authors: Evans Carolyn L
Published: September 2003

To address the economic significance of national border effects, this paper provides evidence on two fundamental questions: (1) Do large border effects arise because of high perceived-price wedges between foreign and domestic products, or because imports and domestic goods are very close substitutes?; and (2) If price wedges are important, do they reflect distortionary barriers to trade or do they arise from nondistortionary factors, such as differences in transactions costs or product characteristics? I conclude that, while border effects may imply barriers, welfare costs, and a role for policy, distortions are probably not as substantial as initial border results suggested.
Is the Threat of Reemployment Services More Effective Than the Services Themselves? Evidence from Random Assignment in the UI System
Authors: Black Dan A , Smith Jeffrey A , Berger Mark C , Noel Brett J
Published: September 2003

We examine the effect of the Worker Profiling and Reemployment Services system. This program “profiles” Unemployment Insurance (UI) claimants to determine their probability of benefit exhaustion and then provides mandatory employment and training services to claimants with high predicted probabilities. Using a unique experimental design, we estimate that the program reduces mean weeks of UI benefit receipt by about 2.2 weeks, reduces mean UI benefits received by about $143, and increases subsequent earnings by over $1,050. Most of the effect results from a sharp increase in early UI exits in the treatment group relative to the control group.
Information, Decisions, and Productivity: On-Board Computers and Capacity Utilization in Trucking
Authors: Hubbard Thomas N
Published: September 2003

Productivity reflects not only how efficiently inputs are transformed into outputs, but also how well information is applied to resource allocation decisions. This paper examines how information technology has affected capacity utilization in the trucking industry. Estimates for 1997 indicate that advanced on-board computers (OBCs) have increased capacity utilization among adopting trucks by 13 percent. These increases are higher than for 1992, suggesting lags in the returns to adoption, and are highly skewed across hauls. The 1997 estimates imply that OBCs have enabled 3-percent higher capacity utilization in the industry, which translates to billions of dollars of annual benefits.
Halving Global Poverty
Authors: Besley Timothy , Burgess Robin
Published: September 2003

The Millennium Development Goals—global targets that the world's leaders set at the Millennium Summit in September 2000—are an ambitious agenda for reducing poverty. As a central plank, these goals include halving the proportion of people living below a dollar a day from around 30 percent of the developing world’s population in 1990 to 15 percent by 2015—a reduction in the absolute number of poor of around one billion. This paper examines what economic research can tell us about how to fulfill these goals. It begins by discussing poverty trends on a global scale—where the poor are located in the world and how their numbers have been changing over time. It then discusses the relationship of economic growth and income distribution to poverty reduction. Finally, it suggests an evidence-based agenda for poverty reduction in the developing world.
Can Foreign Aid Buy Growth?
Authors: Easterly William
Published: September 2003

The widely publicized finding that “aid promotes growth in a good policy environment” is not robust to the inclusion of new data or alternative definitions of “aid,” “policy” or “growth.” The idea that “aid buys growth” is on shaky ground theoretically and empirically. It doesn’t help that aid agencies face poor incentives to deliver results and underinvest in enforcing aid conditions and performing scientific evaluations. Aid should set more modest goals, like helping some of the people some of the time, rather than trying to be the catalyst for societywide transformation.
The Trouble with Stock Options
Authors: Hall Brian J , Murphy Kevin J
Published: September 2003

The benefits of stock options are often not large enough to offset the inefficiency implied by the large divergence between the cost of options to companies and the value of options to risk-averse, undiversified executives and employees. Moreover, the benefits of options can often be achieved more effectively and economically through other means. Why are options so prevalent? Several explanations include changes in corporate governance, reporting requirements, taxes, the bull market and managerial rent-seeking. We offer an alternative hypothesis: boards and managers incorrectly perceive stock options to be inexpensive because options create no accounting charge and require no cash outlay.
Executive Compensation as an Agency Problem
Authors: Bebchuk Lucian Arye , Fried Jesse M
Published: September 2003

This paper provides an overview of the main theoretical elements and empirical underpinnings of a “managerial power” approach to executive compensation. Under this approach, the design of executive compensation is viewed not only as an instrument for addressing the agency problem between managers and shareholders but also as part of the agency problem itself. Boards of publicly traded companies with dispersed ownership, we argue, cannot be expected to bargain at arm's length with managers. As a result, managers wield substantial influence over their own pay arrangements, and they have an interest in reducing the saliency of the amount of their pay and the extent to which that pay is decoupled from managers' performance. We show that the managerial power approach can explain many features of the executive compensation landscape, including ones that many researchers have long viewed as puzzling. Among other things, we discuss option plan design, stealth compensation, executive loans, payments to departing executives, retirement benefits, the use of compensation consultants, and the observed relationship between CEO power and pay. We also explain how managerial influence might lead to substantially inefficient arrangements that produce weak or even perverse incentives.
Why Have Americans Become More Obese?
Authors: Cutler David M , Glaeser Edward L , Shapiro Jesse M
Published: September 2003

Americans have become considerably more obese over the past 25 years. This increase is primarily the result of consuming more calories. The increase in food consumption is itself the result of technological innovations which made it possible for food to be mass prepared far from the point of consumption, and consumed with lower time costs of preparation and cleaning. Price changes are normally beneficial, but may not be if people have self-control problems. This applies to some, but not most, of the population.
The Negative Income Tax and the Evolution of U.S. Welfare Policy
Authors: Moffitt Robert A
Published: September 2003

The negative income tax proposed by Milton Friedman represents one of the fundamental ideas of modern welfare policy. However, the academic literature has raised two difficulties with it, one challenging its purported work incentives and the other suggesting the possible superiority of work requirements. In addition, work requirement approaches have gained ground in actual U.S. welfare policy over the last 30 years and the number of different programs has proliferated, another development counter to the negative income tax. On the other hand, the Earned Income Tax Credit has produced a negative-income-tax-like program on a vast scale.
The Economics and Law of Sexual Harassment in the Workplace
Authors: Basu Kaushik
Published: September 2003

Suppose a firm has a widespread reputation for sexually harassing its employees. When a person signs up to work for such a firm, it would appear that both the firm and the worker are better off by virtue of the ‘exchange’. Is there a case then for government to ban sexual harassment in the workplace? Starting from this question, this paper constructs an argument for legislative intervention. This ‘economic approach’ is applied to other labor market practices and is used to evaluate and critique the current law concerning sexual harassment in the U.S. and other nations.
In Honor of Matthew Rabin: Winner of the John Bates Clark Medal
Authors: Camerer Colin , Thaler Richard H
Published: September 2003

Matthew Rabin's Clark medal honors his abilities to digest huge amounts of nuanced psychology, create simple models capturing that psychology, and do behavioral economics with those models. After warming up by solving hard problems in modeling pre-game communication, his behavioral career began with a seminal paper on reciprocity. He also created models of “present-bias” in time discounting, and derived some surprises from them, and implications (e.g., deadlinesetting and sin taxes). Matthew has also studied quasi-Bayesian models of judgment biases (confirmation and overgeneralization from small samples), overprojection of current feelings into the future, and how moral rules differ from moral tastes.
Retrospectives: Who Invented Instrumental Variable Regression?
Authors: Stock James H , Trebbi Francesco
Published: September 2003

The instrumental variables estimator first appeared explicitly in Appendix B of The Tariff on Animal and Vegetable Oils by Philip G. Wright (1928). It has been suggested that this appendix was written by Philip's son Sewall Wright, then already an important genetic statistician. To find out who wrote Appendix B, we use stylometric statistics to compare it to other texts known to have been written solely by the father and son. The sharp results are consistent with contextual and historical evidence on the authorship of Appendix B and on the origination of the idea of IV estimation.
Recommendations for Further Reading
Authors: Saffran Bernard
Published: September 2003

This section will list readings that may be especially useful to teachers of undergraduate economics, as well as other articles that are of broader cultural interest. In general, the articles chosen will be expository or integrative and not focus on original research. If you write or read an appropriate article, please send a copy of the article (and possibly a few sentences describing it) to Bernard Saffran, c/o Journal of Economic Perspectives, Department of Economics, Swarthmore College, 19081.
Comments
Authors: Tullock Gordon , Michaelowa Axel
Published: September 2003

To be considered for publication in the Comments section, letters should be relatively short—generally fewer than 1,000 words—and should be sent to the journal offices at the address appearing inside the front cover. The editors will choose which letters will be published. All published letters will be subject to editing for style and length.
From frogs’ legs to pieds-noirs and beyond: some aspects of cochlear implantation
Authors: Graham John M.
Published: September 2003

The 2002 Graham Fraser Memorial Lecture deals first with the French origins of cochlear implantation in Paris in the 1950s and the role of André Djourno and Charles Eyriès. Following this work in Paris Dr William House in Los Angeles continued work on cochlear implants and, subsequently, experimental implant programmes were started in California, Paris, Vienna and Melbourne.

The next section of this lecture covers the experimental work of Galvani in establishing the role of electricity in physiology. The results of his first experiments were published in 1791, the year that Mondini produced the first account of a cochlear malformation in a congenitally deaf child.

At around the same time sign language for congenitally deaf children was being developed for the first time in Paris by Epée and the first disputes occurred between oralists and those who promoted signing for the education of congenitally deaf children.

In a present day cochlear implant programme good results from implanting congenitally deaf children at an early age and implanting adults who have become profoundly deaf are now taken for granted. We do have much to learn, however, from more complex implant candidates and some examples of such candidates are presented.

Lastly, looking to the future, the use of PET scanning to try and gain information about how the brain handles the information provided to it by a cochlear implant is described.
Nasal snuff: historical review and health related aspects
Authors: Sapundzhiev Nikolay , Werner Jochen Alfred
Published: September 2003

With cigarette smoking declining in the modern world, the tobacco industry has to look for other products that can keep the old customers and attract new ones. Different forms of smokeless tobacco are currently massively promoted and are gaining in importance. Dry nasal snuff – the oldest known form of tobacco in Europe – is one of them. The health risks associated with it are different to those attributed to smoking and oral wet snuff. The nicotine contained leads to dependency. Its resorption rate is similar to that of smoking, so it could be seen as an adequate substitutional therapy. The risk for cardiovascular diseases is lower, compared to that for smokers. Chronic abuse leads to morphological and functional changes in the nasal mucosa. Although it contains substances that are potentially carcinogenic, at present, there is no firm evidence, relating the use of nasal snuff to a higher incidence of head and neck or other malignancies.
High resolution computed tomography and magnetic resonance imaging in the pre-operative assessment of cochlear implant patients
Authors: Gleeson T. G. , Lacy P. D. , Bresnihan M. , Gaffney R. , Brennan P. , Viani L.
Published: September 2003

Optimal imaging protocols for cochlear implantation have yet to be determined. Pre-operative computed tomography (CT) and magnetic resonance image (MRI) scans are used to assess cochlear anatomy and patency, to delineate surgical access, and to aid in choice of side for implantation. However, opinion still differs as to which modality provides more information in pre-operative assessment, or if, indeed, a combination of the two is superior.

The first 88 patients on the Irish National Cochlear Implant Programme (NCIP) were retrospectively studied to determine the accuracy of pre-operative CT and MRI in predicting abnormalities at the time of surgery. Correlation with surgical findings was determined in three separate groups of patients (those who had CT only, those who had MRI only, and those who had both CT and MRI performed).

Of the 24 patients that had both CT and MRI performed, both modalities had a 79 per cent correlation with surgical findings. CT and MRI reports concurred in 75 per cent of cases. Specificity and negative predictive value were high (86 per cent and 90 per cent, respectively). CT alone (47 cases) correlated with surgery in 39 cases (83 per cent); MRI alone (17 cases) correlated in 15 cases (88 per cent).

The findings of this study suggest that CT and MRI are effective at predicting normal inner ear anatomy, and thus at predicting the patient and the cochlea most suitable for implantation. Both modalities are useful in determining the side of implantation, thus avoiding potential surgical difficulties in cases of unilateral abnormalities. There was no significant difference between the ability of MRI and CT to detect abnormalities at the time of surgery. In this series the combination of CT and MRI has not been shown to be superior to either modality used alone, although anecdotal evidence to the contrary was noted.
Methodology for studying the effects of topically applied ear drops on otoacoustic emissions in guinea pigs
Authors: Migirov Lela , Himmelfarb Mordechay
Published: September 2003

Testing of otoacoustic emissions (OAE) has been successfully applied to study outer hair cell function. We used this methodology to evaluate and compare the effect of topically applied normal saline, and gentamicin- and ciprofloxacin-containing drops into the middle ear of guinea pigs. All three solutions similarly decreased the distortion product OAE (DPOAE) and all three caused an inflammatory reaction in the guinea pig’s middle-ear. OAE failed to detect adequately the ototoxicity of topically administered drops in this animal model because the opening of the bulla affected DPOAE, and both inflamed middle-ear mucosa and osteoneogenesis caused a decrease in DPOAE amplitude.

This is the first report examining the influence of topically used otic drops on inner ear function as demonstrated by OAE.
Effect of topically applied povidone-iodine on transient evoked otoacoustic emissions in guinea pigs
Authors: Yagiz Recep , Tas Abdullah , Uzun Cem , Adali Mustafa Kemal , Koten Muhsin , Karasalihoglu Ahmet Rifat
Published: September 2003

The possible cochlear toxicity of topically applied povidone-iodine solution was investigated in guinea pigs by measuring transiently evoked otoacoustic emissions (TEOAEs). Seven adult pigmented guinea pigs (14 ears) with a normal acoustic pinna reflex were used. After the baseline TEOAE measurements, 0.1mL of povidone-iodine solution was applied transtympanically into the middle ear in the study group. Saline solution and gentamicin were used as negative and positive control, respectively. TEOAE measurements were repeated on the 10th day, and four weeks after the first application. Tympanometric measurements were also carried out for both ears of all animals at the end of the study. Responses in all ears, which had povidone-iodine applied to them, disappeared in a way similar to those recorded in gentamicin-treated ears. Tympanometric measurements at the end of the study showed ’type A’ tympanograms in all ears of all animals. The present study showed that povidone-iodine could have a cochleotoxic effect in guinea pigs. A study in humans with TEOAE before and after middle-ear surgery, where povidone-iodine can reach into the middle-ear cavity, may be useful for evaluating this result for clinical practice.
Increased post-operative haemorrhage seen in adult coblation tonsillectomy
Authors: Noon A. P. , Hargreaves S.
Published: September 2003

Coblation is a new soft tissue surgical technique that is being used for tonsillectomy. Published results show a significant decrease in the amount of post-operative pain experienced y patients undergoing coblation tonsillectomy. There has been no published work to date on the incidence of post-operative haemorrhage. From August 2001 to November 2002 one surgeon performed 36 coblation tonsillectomies on adults. On another list he performed 29 by his standard method of dissection and bipolar coagulation. Retrospective analysis found a significant increase in the secondary haemorrhage rate in adult patients undergoing coblation tonsillectomy (22.2 vs. 3.4 per cent). At our department coblation tonsillectomy has been abandoned until further work into its safety has been published.
Does synchronous nasal surgery increase the risk of post-operative haemorrhage in adult patients undergoing tonsillectomy?
Authors: Murray D. P. , El-Hakim H. , Ahsan F. , Nunez D. A.
Published: September 2003

Otolaryngologists occasionally perform simultaneous procedures on their patients, the indication being co-existent pathology. This is not a universally accepted practice as some feel that the post-operative morbidity is increased in such patients.

Tonsillectomy is a common otolaryngological procedure and the main life-threatening complication, haemorrhage is easily identifiable. This study compares the incidence of post-operative haemorrhage requiring admission in patients undergoing tonsillectomy alone with that in patients undergoing tonsillectomy and nasal surgery.

A retrospective study was undertaken of all adult patients undergoing tonsillectomy alone or tonsillectomy and synchronous nasal surgery in Aberdeen Royal Infirmary.

Seventy-one patients (34 male) with a mean age of 23 years underwent tonsillectomy and synchronous nasal surgery over a nine-year period 1991–1999. The commonest nasal procedure was reduction of the inferior turbinates (in 48 cases). Three hundred and ninety-eight patients (131 male) with a mean age of 23 years underwent tonsillectomy alone over a nine-month period, July 1998 to April 1999.

The incidence of post-tonsillectomy haemorrhage in the synchronous nasal surgery group was 12.7 per cent (9 out of 71) compared with four per cent (16 out of 398) in the tonsillectomy alone group (p <0.01, Chi-squared test). There was no difference in hospital stay between the two groups (mean two days).

Synchronous nasal surgery increases the incidence of post-tonsillectomy haemorrhage.
Management of thyroglossal tract disease after failed Sistrunk’s procedure
Authors: Patel N. N. , Hartley B. E. J. , Howard D. J.
Published: September 2003

Sistrunk’s procedure for thyroglossal duct remnants has a very high success rate, there remains the occasional patient, however, that will have recurrent disease despite a competently performed operation. Applied anatomy and embryology proffer a solution to this problem. Extending the Sistrunk operation, with an anterior wide local excision remaining within normal tissue, enables removal of the entire thyroglossal tract remnant.

A retrospective case note review was conducted to study our experience using this extended procedure to treat patients with thyroglossal tract disease that had recurred after a previous Sistrunk’s operation.

Six patients aged from five to 33 years were included in the study. There was one recurrence and the complication rate was comparable to the standard operation.

It was concluded that a wide local excision is a valuable extension of the Sistrunk operation for the management of recurrent disease.
Treatment of primary mucosal head and neck squamous cell carcinoma using photodynamic therapy: results after 25 treated cases
Authors: Dilkes M. G. , Benjamin E. , Ovaisi S. , Banerjee A. S.
Published: September 2003

The use of photodynamic therapy for the treatment of malignant and non-malignant conditions is increasing. This paper demonstrates the efficacy of a second-generation photosensitizer, Foscan®, in the primary treatment of a wide range of mucosal head and neck squamous cell carcinomas. Tumours ranged in stage from T1 to T3. A complete response to primary treatment was seen in 19/21 patients (90 per cent). In laryngeal cancer recurrent after radical radiotherapy, one out of four patients treated obtained a complete response (25 per cent). Six patients (24 per cent) required surgery after photodynamic therapy, for local recurrence or dysplasia. Mean follow up was for 27.3 months (standard deviation 20.6 months).
Technique for secondary tracheo-oesophageal puncture in difficult necks
Authors: Sharma R. K. , Rogers M. , Thind J. , Mabley A. T. W.
Published: September 2003

A secondary tracheo-oesophageal puncture is required for voice restoration post-laryngectomy either for reasons of closure of the primary fistula or as a planned secondary procedure. A method of doing this safely is described using an endotracheal tube and a flexible nasopharyngoscope in especially difficult cases.
Medical treatment of nasal squamous papilloma with imiquimod cream
Authors: Caversaccio Marco , Aebi Stefan
Published: September 2003

Warts are common lesions. The prevalence and incidence of squamous papilloma of the nasal vestibulum are not known, and it is not certain how often human papilloma viruses are involved. Numerous medical or surgical treatment modalities have been reported in the literature with variable, sometimes unsatisfactory results. Imiquimod cream is a topically applied immunomodulator. It is used for warts and other skin tumours on different locations of the body. We report results of six patients treated with imiquimod five per cent cream for nasal squamous papilloma.
New sinus culture applicator (Yariktas applicator)
Authors: Yariktas Murat , Doner Fehmi , Demirci Mustafa , Dogru Harun
Published: September 2003

Identification of the pathogen is crucial for the selection of an appropriate antibiotic in the management of sinusitis. We describe an original instrument that provides contamination-free culture from the sinus in endoscopic sinus surgery.
Atypical keratosis obturans
Authors: Persaud Ricardo , Chatrath Paul , Cheesman Anthony
Published: September 2003

Keratosis obturans is a rare condition characterized by the accumulation of desquamated keratin material in the bony portion of the external auditory canal. Classically, it is reported to present with severe otalgia, conductive deafness and global widening of the canal. A case of keratosis obturans is described in which the principal symptom was a metallic taste and the main finding was extensive erosion of the hypotympanum with exposure of the facial nerve and the annulus of the tympanic membrane. This presenting symptom and resorption pattern are atypical of keratosis obturans and have not been documented previously.
Supratentorial arachnoid cyst mimicking a Ménière’s disease attack
Authors: Buongiorno Giuseppe , Ricca Giovanni
Published: September 2003

Arachnoid cysts (AC) often present with symptoms depending on their anatomical location within the skull; while supratentorial cysts grow causing relatively few symptoms, infratentorial ones may impair liquor circulation at the level of the fourth ventricle, giving rise to intracranial hypertension, or may stretch the complex nerve network in the cerebello-pontine angle. We report the singular clinical history of a 54-year-old male, who suddenly began to feel dizzy while sitting at his workplace, complaining of left tinnitus and aural fullness, in a classic clinical picture of Ménière’s disease. The anomalous findings at otoneurological examination (markedly the left deviation at the Fukuda test) made a magnetic resonance image (MRI) scan mandatory and a huge AC was found in the left fronto-parietal lobe. The mass provoked an evident clockwise rotation of the brainstem that we suppose to be the cause of acoustico-facial bundle stretching explaining the vestibular symptomatology.
Salivary duct carcinoma of submandibular gland with trigeminal nerve invasion to intracranium
Authors: Li Chia-Hug , Su Chih-Ying , Chien Chih-Yen , Hwang Chung-Feng , Huang Hsiu-Yu
Published: September 2003

Salivary duct carcinoma is a rare and invasive malignant tumour with rapid distant metastasis and dismal prognosis. Clinically, perineural invasion of the salivary duct carcinoma is commonly noted. Here, we present a case of salivary duct carcinoma of submandibular gland origin with perineural invasion of the trigeminal nerve proximal to the intracranium, that was well demonstrated by a magnetic resonance image (MRI) and was consistent with the clinical presentation. This case received radical resection and radiotherapy with inclusion of the skull base within the field. There was no tumour recurrence and distant metastasis 24 months post-operatively.
Intramuscular capillary hamartoma of the tongue
Authors: Gillett D. , Fahmy F. , Eveson J. W. , Shotton J. C.
Published: September 2003

Intramuscular vascular lesions in the tongue are rare and are usually the capillary form of haemangioma. A case is described of a lingual mass that resembled intramuscular haemangioma but had unique histological features that do not appear to have been described previously. The term intramuscular capillary hamartoma is suggested to describe it.
Ewings’ sarcoma of the mandible
Authors: Quesada Juan L. , Alcalde Juan M. , Espinosa Juan M. , García-Tapia Rafael
Published: September 2003

Ewings’ sarcoma involving the facial bones is rare although it is the second most frequent bone malignancy. For the diagnosis a biopsy is needed. Currently the treatment is the combination of chemotherapy and radiotherapy with surgery indicated in only a few instances. We report a case of Ewing’s sarcoma of the mandible and describe its clinicopathologic features and the treatment of this disease.
Benign ectopic submandibular thyroid with a normotopic multinodular goitre
Authors: Mace A.T.M. , McLaughlin I. , Gibson I.W. , Clark L. J.
Published: September 2003

Ectopic submandibular thyroid tissue is a rare entity and poses difficult diagnostic and management problems. The first case of ectopic submandibular thyroid with a normotopic multinodular goitre is presented