bluuebunny/crossref_metadata_2025 huggingface dataset:
Financing of wasteland afforestation in India
Authors: Balooni Kulbhushan , Singh Katar
Published: August 2003

India has vast tracts of wastelands, which have been lying barren for ages. Most such lands are physically suitable for growing trees and thus could be put to socially productive uses. However, although usually economically viable, afforestation requires massive initial investment, generally beyond the means of the landowners. Also, government budgetary allocations do not cover current needs. In this situation, institutional credit is required. The National Bank for Agriculture and Rural Development (NABARD) of India has recognized this need and has devised a number of different schemes to provide refinance facilities to individuals and organisations. Although the number of forestry schemes refinanced by NABARD has increased rapidly in the past, they currently constitute only about 1% of the total number of loans sanctioned, and only about 2% of NABARD's cumulative loan disbursement to date. In fact, since 1992, the share of afforestation schemes has declined. A number of factors have been identified as major constraints, including time‐consuming and complicated procedures for accessing land; restrictions on harvesting and selling trees; delays in sanctioning and disbursement of bank credit; non‐remunerative prices for tree products; and flawed public policies and programmes. This article argues that unless these constraints are overcome, NABARD will not be able to play an effective role in speeding up development programmes in the forestry sector. It further argues that most of the current constraints on institutional credit for wasteland afforestation can be removed or relaxed. Practical strategies are suggested to mobilize more funds and channel more institutional credit for wasteland afforestation in India.
Death for a Terrorist: Media Coverage of the McVeigh Execution as a Case Study in Interorganizational Partnering between the Public and Private Sectors
Authors: Smith Linda Wines , Roberts John W.
Published: August 2003

In June 2001, the Federal Bureau of Prisons helped to carry out the execution of Timothy McVeigh for his role in the infamous 1995 bombing of the Murrah Federal Building in Oklahoma City. The intense national and international media attention that the execution received was virtually unprecedented in the bureau's history, and it put the bureau in the difficult position of having to carry out two potentially conflicting responsibilities: facilitating coverage of the execution by hundreds of reporters, producers, and technicians, while maintaining the safety and security of the maximum security penitentiary in which the execution was held. Historically, the Bureau of Prisons has preferred to maintain a low media profile and had no experience managing a large‐scale media event. This article examines how the bureau met this challenge by forming a partnership with the news media through the creation of a Media Advisory Group. It analyzes the goals, functions, and achievements of the Media Advisory Group by employing the Dawes model of interorganizational relationships.
“Publics” Administration and the Ethics of Particularity
Authors: Brady F. Neil
Published: August 2003

Ethical orientations that emphasize universal duties, ideals, and values are well known to public administrators. We pay attention to principle, policy, ideals, shared goals, and the provision of a variety of commonly held values, such as clean air and water, mosquito abatement, and public recreation. The word “public” often seems to be a synonym for “universal.” However, this article explores particularity in ethics, especially as it applies to the life of the public servant. It identifies three distinct orientations that focus on the concrete—as opposed to the abstract—and it shows how the exceptional cases are not administrative problems; rather they provide a reality check for public administrators who suppose rules, plans, and programs to be their primary orientation toward the management of public concerns.
Assessing the Effects of Public Participation
Authors: Halvorsen Kathleen E.
Published: August 2003

This article presents the results of research designed to test participatory democracy assertions that high‐quality public participation can affect participants' beliefs in desirable ways. It examines the relationships between exposure to quality participation and participant beliefs about the trustworthiness and responsiveness of a public agency and the value of including different viewpoints in public meetings. After participation in quality project meetings, participants were significantly more likely to believe the agency was responsive to public concerns. The results indicate that some specific aspects of quality participation are positively associated with expectations about the agency's responsiveness and performance. Positive associations were also found with tolerance for differences of opinion. These results have important implications for public administrators and theorists of participatory democracy.
Public Leadership in Times of Crisis: Mission Impossible?
Authors: Boin Arjen , Hart Paul 't
Published: August 2003

Crisis management (prevention, preparedness, response, and reconstruction) is a tough task for political and bureaucratic leaders. This article documents the persistent tensions between the expectations and realities of crisis leadership. It explores the popular notion that crises provide key opportunities for reform. The very occurrence of a crisis is then thought to expose the status quo as problematic, making it easier to gain momentum for alternative policies and institutions. We argue that the opportunities for reform in the wake of crisis are smaller than often thought. The prime reason is that the requisites of crisis leadership are at odds with the requirements of effective reform.
Taxes, Subsidies, and Listeners Like You: Public Policy and Contributions to Public Radio
Authors: Brooks Arthur C.
Published: August 2003

Public radio in the United States receives both direct and indirect government funding. Direct subsidies come in the form of lump‐sum and matching grants, while indirect subsidies proceed from tax revenues forgone on tax‐deductible private donations. Each of these sources of government money affects charitable giving to public radio. This article estimates both of these effects, using data on 91 public radio stations in the United States during 1995. Data analysis shows that public funding to stations has a positive impact on private giving, but this impact rapidly decreases as the level of government subsidies increases. The analysis also indicates that increases in state tax rates correspond with significantly higher donation levels. This article explores the implications of these and other findings for policy makers, public administrators, and nonprofit managers.
An Analysis of Presidential Preferences in the Distribution of Empowerment Zones and Enterprise Communities
Authors: Wallace Marc A.
Published: August 2003

Critics regarded the selection of urban empowerment zones and enterprise communities by Secretary Cisneros in 1994 as sympathetic to President Clinton's considerations. However, the secretary countered that cities were chosen based on their ability to revitalize their communities successfully, as outlined in their applications. To determine whether the secretary responded to top‐down presidential preferences, data from the complete list of applications is used to test four hypotheses derived from principal—agent theory. The results of the logistic regression models do not validate the significance of the presidential variables (for instance, presidential support score for each city's congressional delegation, marginal districts, and 1992 state vote for President Clinton). Rather, many of the nonpresidential variables (community participation, size of the empowerment zone or enterprise community, and poverty) were significant in supporting the secretary's contention.
Environmental Justice and Information Technologies: Overcoming the Information‐Access Paradox in Urban Communities
Authors: Kellogg Wendy A. , Mathur Anjali
Published: August 2003

Scientific studies and resident testimony suggest that urban residents in low‐income and minority communities have been subject to an unequal burden of environmental pollution and inequitable environmental enforcement practices. A key component of the equitable development and implementation of environmental policies is the participation of citizens and community‐based organizations in the policy process. Such participation rests upon equitable access to agency‐generated environmental information and effective use of that information by citizens. This article focuses on the adoption of Internet technologies by environmental agencies as a mechanism for disseminating information and the implications for low‐income and minority residents in urban communities. A framework is developed to guide a programmatic response to overcome these implications. The results from several community‐based projects are described and analyzed for their capacity‐building effectiveness. Analysis of the projects indicates improvement in community capacity for information access and use, which bolstered community participation in the environmental decision‐making process.
Why Measure Performance? Different Purposes Require Different Measures
Authors: Behn Robert D.
Published: August 2003

Performance measurement is not an end in itself. So why should public managers measure performance? Because they may find such measures helpful in achieving eight specific managerial purposes. As part of their overall management strategy, public managers can use performance measures to evaluate, control, budget, motivate, promote, celebrate, learn, and improve. Unfortunately, no single performance measure is appropriate for all eight purposes. Consequently, public managers should not seek the one magic performance measure. Instead, they need to think seriously about the managerial purposes to which performance measurement might contribute and how they might deploy these measures. Only then can they select measures with the characteristics necessary to help achieve each purpose. Without at least a tentative theory about how performance measures can be employed to foster improvement (which is the core purpose behind the other seven), public managers will be unable to decide what should be measured.
Better than Raw: A Guide to Measuring Organizational Performance with Adjusted Performance Measures
Authors: Rubenstein Ross , Schwartz Amy Ellen , Stiefel Leanna
Published: August 2003

Like oysters on the half shell, some things are better when they're raw. In evaluating the performance of organizations and providing guidance for improving performance, however, raw performance measures, such as test scores or success rates, are often inferior to performance measures adjusted for client and environmental characteristics, or adjusted performance measures (APMs). Using examples from a variety of public services and data on public schools in Georgia, we compare the performance data generated by raw scores and by APMs. We conclude with guidance for constructing and using adjusted performance measures.
Credible Commitment and Council‐Manager Government: Implications for Policy Instrument Choices
Authors: Feiock Richard C. , Jeong Moon‐Gi , Kim Jaehoon
Published: August 2003

The credible constraint of morally hazardous or opportunistic behavior can enhance efficiency. This idea is applied to an examination of local government institutions to identify how council‐manager government constrains opportunism in economic development by substituting low‐power bureaucratic incentives for high‐power electoral incentives. A panel design isolates changes in the use of development strategies or instruments in 516 cities.

The central argument presented here is that the Progressive ideology of the separation of politics and administration, institutionalized in the council‐manager plan, allows administrators and elected officers to more easily resist opportunistic behavior. Economic and political forces have significant effects that are different for mayor‐council communities than for council‐manager communities. The influence of strategic planning is evident in council‐manager cities, but not in mayor‐council communities. Under council‐manager government, development is carried out in a discriminating manner, leading to lower levels of financial incentives but more loan and business‐attraction programs. In conclusion, the authors discuss how the career patterns of city managers are shaped by the incentive structures created by the council‐manager plan.
Ties That Do Not Bind: Musings on the Specious Relevance of Academic Research
Authors: Bolton Michael J. , Stolcis Gregory B.
Published: August 2003

This article discusses the lack of congruence between academic research and practice in the field of public administration. It argues that this disconnect can be traced to the ambiguous and conflicting goals and expectations of scholarly research: (1) the creation of theoretical versus pragmatic knowledge; (2) the use of data‐supported versus logic‐driven information; (3) the use of the scientific method versus case studies; (4) the prestige of academic‐oriented versus practitioner‐oriented journals; and (5) the pressures of academic tenure versus the need for organizational effectiveness. The article explores the state of academic research in other disciplines and offers five solutions to narrow the gap between the academy and the agency settings.
Public Administration in the Twenty‐First Century
Authors: Lynn, Jr. Laurence E.
Published: August 2003

Books reviewed in this article:

Donald F. Kettl, The Transformation of Governance: Public Administration for the Twenty‐First Century America

Lester M. Salamon (ed.), The Tools of Government: A Guide to the New Governance

H. George Frederickson and Kevin B. Smith, The Public Administration Theory Primer
Visualization and measurement of quantum rotational dynamics
Authors: Dimeo R. M.
Published: August 2003

An introduction to quantum rotational tunneling and libration is presented with an emphasis on obtaining a qualitative understanding of this phenomenon through visualization of the dynamics, simple approximations, and measurements. The tunneling and librational dynamics of small molecular rotors are discussed using a very simple model of the rotational potential. Numerical calculations of the evolution of probability packets are carried out for the low-lying states and the connection is made between the quantum and classical librational dynamics. Finally, we present measurements of these quantum rotations using inelastic neutron scattering and show in particular how neutron scattering measurements of the ground state tunnel splitting and first librational transition can be used to characterize the magnitude and shape of the potential hindering the motion of the rotor. Some conceptual and computational problems are included that are suitable for undergraduate students.
An extinction theorem for electromagnetic waves in a point dipole model
Authors: Berman David H.
Published: August 2003

A transfer matrix method is used to show that an electromagnetic wave in a cubic lattice of point dipoles propagates as if its wave speed has been reduced from c in vacuo to c/n, where n is the index of refraction, while in the interstices the wave speed is c. Because the lattice is not a continuum, there are evanescent waves between lattice planes. These waves ultimately give rise to the Lorentz–Lorenz result for n and produce rapid variations of the polarization in the first few lattice planes. These rapid variations indicate that there is an extinction length over which the external wave is converted to the internal wave propagating at the reduced speed. This length is the distance over which the local field assumes its bulk value. The possibility of an extinction length in recent work on the Ewald–Oseen theorem was missed because only continuum models were considered.
Apparatus to measure relativistic mass increase
Authors: Luetzelschwab John W.
Published: August 2003

An apparatus that uses readily available material to measure the relativistic mass increase of beta particles from a radioactive Tl204 source is described. Although the most accurate analysis uses curve fitting or a Kurie plot, students may just use the raw data and a simple calculation to verify the relativistic mass increase.
Derivation of relativistic corrections to bounded and unbounded motion in a weak gravitational field by integrating the equations of motion
Authors: Ovanesyan Grigory
Published: August 2003

The deviation of light by a star and the precession of the perihelion of a planetary orbit are usually derived by independent methods. In the present paper the equations of motion for weak gravitation are integrated approximately and both effects are derived simultaneously.
Watching a drunkard for 10 nights: A study of distributions of variances
Authors: Zia R. K. P. , Schmittmann B.
Published: August 2003

For any physical observable in statistical systems, the most frequently studied quantities are its average and standard deviation. Yet, its full distribution often carries extremely interesting information and can be invoked to put the properties of the individual moments into perspective. As an example, we consider a problem concerning simple random walks. When a drunk is observed over L nights, taking N steps per night, and the number of steps to the right is recorded for each night, an average and a variance based on these data can be calculated. When the variance is used to estimate p, the probability for the drunk to step right, complex values for p are frequently found. To put such obviously nonsensical results into context, we study the full probability distribution for the variance of the data string. We discuss the connection of our results to the problem of data binning and provide two other examples to demonstrate the importance of full distributions.
Thermodynamics of the harmonic oscillator: Wien’s displacement law and the Planck spectrum
Authors: Boyer Timothy H.
Published: August 2003

A thermodynamic analysis of the harmonic oscillator is presented. The motivation is provided by the blackbody radiation spectrum, because radiation modes take the harmonic-oscillator form. We use the behavior of a thermal harmonic oscillator system under a quasistatic change of oscillator frequency ω to show that the thermodynamic functions can all be derived from a single function of ω/T, analogous to Wien’s displacement theorem. The high- and low-frequency limits yield asymptotic forms involving the temperature T alone or frequency ω alone, corresponding to energy equipartition and zero-point energy. We suggest a natural interpolation between the limiting forms. The Planck spectrum with zero-point energy corresponds to the function satisfying the Wien displacement result which provides the smoothest possible interpolation between energy equipartition at low frequency and zero-point energy at high frequency.
Electrodynamics and elasticity
Authors: Dmitriyev Valery P.
Published: August 2003

We consider a Lorenz-like gauge theory with a second speed parameter that differs from the speed of light. This theory extends electrodynamics so that it has two speeds corresponding to the speeds of transverse and longitudinal waves in vacuum. The two-parameter extension of electrodynamics can be formally mapped onto the linear theory of elasticity. Because the case of equal speeds is not realized in an elastic medium, a compressible medium cannot model electromagnetism. In the Coulomb gauge electrodynamics can be formally mapped onto incompressible elasticity, which suggests that a linear-elastic incompressible medium can serve as a model of electromagnetism.
Dispersive properties of probability densities in quantum mechanics
Authors: Mita Katsunori
Published: August 2003

It is shown that the imaginary part of ψ*Pψ plays a crucial role in describing the dispersive properties of probability densities in quantum mechanics. The quantity Im(ψ*Pψ) is proportional to the dispersive velocity of the probability density and has the same form as the diffusion current. The dispersive velocity does not contribute to the expectation value of the momentum operator, but contributes to the expectation value of the kinetic energy operator. The interpretation of the dispersive velocity is given for the one-dimensional Gaussian wave packet, the stationary states of a particle in a one-dimensional box, and the stationary states of the hydrogen atom.
Shielding by perfect conductors: An alternative approach
Authors: Yoon Sung Hyun
Published: August 2003

Given conductors and charges outside the conductors, is the superposition of the electric potentials due to induced charges on the conductor surfaces and other charges constant in the conducting region? Although it is a natural question raised by students of electromagnetism, it does not seem to be addressed directly in textbooks. An identity that relates the potential due to the induced charge on a closed conductor surface to other potentials is useful for answering the question and also for making clearer the phenomenon of electrostatic shielding.
The magnetic field of an infinite solenoid
Authors: Espinosa Olivier , Slusarenko Viktor
Published: August 2003

We use the Biot–Savart law for filamentary currents to show that the magnetic field produced by an infinitely long straight strip of infinitesimal width carrying a uniform transverse surface current can be written in simple geometrical terms. We use this result to calculate the magnetic field of an infinite solenoid of arbitrary but uniform cross-sectional shape.
The potential, electric field and surface charges for a resistive long straight strip carrying a steady current
Authors: Hernandes J. A. , Assis A. K. T.
Published: August 2003

We consider a long resistive straight strip carrying a constant current and calculate the potential and electric field everywhere in space and the density of surface charges along the strip. We compare these calculations with experimental results.
Two magnets and a ball bearing: A simple demonstration of the method of images
Authors: Poon W. C. K.
Published: August 2003

Motivated by an observation of a popular children’s toy, I investigate the behavior of a bar magnet with a steel ball bearing held on one of its poles as it approaches another bar magnet. Mapping the problem onto electrostatics, I give an explanation of my observations based on the behavior of point charges near an isolated, uncharged sphere. This magnetic analog offers a simple demonstration of the familiar “method of images” in electrostatics.
Can a single bubble sink a ship?
Authors: May D. A. , Monaghan J. J.
Published: August 2003

We combine simple experiments and numerical simulations to study the effect of a large, single gas bubble rising underneath a floating body. Our motivation is the possible hazards arising from naturally occurring methane gas hydrates in the North Sea. For floating bodies that possess a hull length of similar scale to the bubble’s radius of curvature, we identify the conditions for the floating body to sink. Our experiments allow us to extend and benchmark numerical simulations using smoothed particle hydrodynamics. There is good agreement between the simulations and experiment.
Electrically induced magnetic fields; a consistent approach
Authors: Batell Brian , Ferstl Andrew
Published: August 2003

Electromagnetic radiation exists because changing magnetic fields induce changing electric fields and vice versa. This fact often appears inconsistent with the way some physics textbooks solve particular problems using Faraday’s law. These types of problems often ask students to find the induced electric field given a current that does not vary linearly with time. A typical example involves a long solenoid carrying a sinusoidal current. This problem is usually solved as an example or assigned as a homework exercise. The solution offered by many textbooks uses the approximation that the induced, changing electric field produces a negligible magnetic field, which is only valid at low frequencies. If this approximation is not explicitly acknowledged, then the solution appears inconsistent with the description of electromagnetic radiation. In other cases, when the problem is solved without this approximation, the electric and magnetic fields are derived from the vector potential. We present a detailed calculation of the electric and magnetic fields inside and outside the long solenoid without using the vector potential. We then offer a comparison of our solution and a solution given in an introductory textbook.
A dynamic new look at the lambda transition
Authors: Goodstein David , Chatto Andrew R.
Published: August 2003

We discuss aspects of the theory of critical phenomena and explore the superfluid transition in He4. We review some of the recent experimental and theoretical work on helium in nonequilibrium conditions and summarize some future space experiments that might shed light on disagreements between theory and experiment.
A simple approach to phase holography
Authors: Toal Vincent
Published: August 2003

A simple mathematical description of thick hologram recording and playback is given using a basic wave front representation. Results are obtained for amplitude and phase holography. This approach is very accessible to students and predicts the important results that are obtained in early and some more advanced holography experiments. The approach is also quite general and applies to transmission and reflection holography.
Sliding on the Surface of a Rough Sphere
Authors: Mungan Carl E.
Published: August 2003

A well-known textbook problem treats the motion of a particle sliding frictionlessly on the surface of a sphere. An interesting variation is to consider what happens when kinetic friction is present.1 This problem can be solved exactly.
The Vocabulary of Introductory Physics and Its Implications for Learning Physics
Authors: Itza-Ortiz Salomon F. , Rebello N. Sanjay , Zollman Dean A. , Rodriguez-Achach Manuel
Published: August 2003

In science new words might be “invented” to name or describe new processes, discoveries, or inventions. However, for the most part, the scientific vocabulary is formed from words we use throughout our lives in everyday language. When we begin studying science we learn new meanings of words we had previously used. Sometimes these new meanings may contradict everyday meanings or seem counterintuitive. We often learn words in association with objects and situations.1 Due to these associations that students bring to class, they may not interpret the physics meaning correctly. This misinterpretation of language leads students to confusion that is sometimes classified as a misconception.2–6 Research about the semantics used in physics textbooks7–9 and the meaning of words has been done,10–12 but the problem seems to go beyond semantics.8 The linguistic relativity hypothesis, sometimes referred to as the Sapir-Whorf hypothesis,1 says that “we see and hear and otherwise experience very largely as we do because the language habits of our community predispose certain choices of interpretation.” An upshot of this hypothesis is that language may not determine thought, but it certainly may influence thought.1 We have to make students conscious of the fact that though the words may remain the same, their everyday meaning is no longer a figure of speech, but a technical meaning (physics meaning). That is, we need to change the way students may “think” about words. In spite of the close relationship between language and thought, most research does not address the semantics used in physics textbooks7–9 and the meaning of words.10–12 This study, however, will address that relationship.
Maximizing Imparted Speed in Elastic Collisions
Authors: Fakhruddin Hasan
Published: August 2003

Consider a particle of mass M traveling with speed V and colliding head on with a stationary particle of smaller mass m (see Fig. 1). The ratio m/M = R. Let the collision be elastic. The speed v imparted to the second particle is given by1 v = 2M(m +M)V. This can be written as v = 2(1 + mM) V or v = 21 + R V. The imparted speed v approaches a maximum value of 2V as R → 0.2 Thus for the two-particle system, maximum speed imparted to m is 2V.
Reconsidering Archimedes' Principle
Authors: Bierman Jeffrey , Kincanon Eric
Published: August 2003

Archimedes' principle as stated originally by Archimedes and in modern texts can lead to an incorrect prediction if the submerged object is in contact with a solid surface. In this paper we look experimentally at a submerged object and show that though the theoretical explanations of the principle are valid, the statement of the principle needs clarification.
Fluid Flow with Logger Pro
Authors: Fairman Stephen J. , Johnson Joseph A. , Walkiewicz Thomas A.
Published: August 2003

Graphical analysis of experimental data that exhibit exponential behavior is typically postponed at many institutions until students are able to understand the theory underlying the concept of radioactive decay or of RC time constants in ac circuits. In 1960 Smithson and Pinkston1 described a laboratory exercise that uses the flow of water from a vertical column through a long horizontal capillary tube as a source of data that models radioactive decay. Many institutions have used this experiment simply as an early introduction to exponential behavior without reference to radioactive decay or ac circuits. Greenslade2 recently described a modification of this experiment to demonstrate the concept of secular equilibrium in radioactive decay. This paper presents results of similar experiments, but visual measurements are replaced in this work by data obtained with modern sensors interfaced to a computer. Experiments are described from simple exponential decay to an analogue of the complex interactions of three nuclides in a radioactive-series decay chain.
Devices to Illustrate Lissajous Figures
Authors: Greenslade Thomas B.
Published: August 2003

Longtime readers of The Physics Teacher will have noted my interest in oscillations and waves.1 In particular, Lissajous figures, which are the resultant of two simple harmonic motions at right angles to each other, have fascinated me since I first saw a device drawing them at Amherst College in 1957. In this paper I want to show some of the apparatus that has been developed to display Lissajous figures. There is more than antiquarian interest here; some of these can be reproduced fairly easily today.
Measuring Horsepower and Torque Curves of a Car
Authors: Buschert John Ross
Published: August 2003

We have developed a system to measure the motion of a car with very good precision. It requires a laptop computer and a standard sensor interface. The added parts are relatively simple and inexpensive, and can be connected to a variety of cars easily and quickly. Using this system, we are able to derive the horsepower and torque versus engine speed for any manual transmission car. Students enjoy the lab because it gives them an excuse to floor their car but it also produces remarkably good data.
Apparatus for Measuring Young's Modulus
Authors: Niculescu Adam , Shumaker Russell
Published: August 2003

This paper describes a simple and inexpensive apparatus that measures the modulus of elasticity for metallic wires.1 The apparatus has been designed so as to minimize the computations that in many instances prove to be a deterrent in the understanding of the physical concepts.
Beginning Your First Year
Authors: Novodvorsky Ingrid
Published: August 2003

This month's column was contributed by fellow teacher Ingrid Novodvorsky from the University of Arizona in Tucson. Her advice is timely for new teachers who will be entering the classroom for the first time this fall. I encourage other teachers to share their suggestions for managing the challenges that first-year instructors face.
Coral Reef Death During the 1997 Indian Ocean Dipole Linked to Indonesian Wildfires
Authors: Abram Nerilie J. , Gagan Michael K. , McCulloch Malcolm T. , Chappell John , Hantoro Wahyoe S.
Published: August 2003

Geochemical anomalies and growth discontinuities in
Porites
corals from western Sumatra, Indonesia, record unanticipated reef mortality during anomalous Indian Ocean Dipole upwelling and a giant red tide in 1997. Sea surface temperature reconstructions show that although some past upwelling events have been stronger, there were no analogous episodes of coral mortality during the past 7000 years, indicating that the 1997 red tide was highly unusual. We show that iron fertilization by the 1997 Indonesian wildfires was sufficient to produce the extraordinary red tide, leading to reef death by asphyxiation. These findings highlight tropical wildfires as an escalating threat to coastal marine ecosystems.
340,000-Year Centennial-Scale Marine Record of Southern Hemisphere Climatic Oscillation
Authors: Pahnke Katharina , Zahn Rainer , Elderfield Henry , Schulz Michael
Published: August 2003

In order to investigate rapid climatic changes at mid-southern latitudes, we have developed centennial-scale paleoceanographic records from the southwest Pacific that enable detailed comparison with Antarctic ice core records. These records suggest close coupling of mid-southern latitudes with Antarctic climate during deglacial and interglacial periods. Glacial sections display higher variability than is seen in Antarctic ice cores, which implies climatic decoupling between mid- and high southern latitudes due to enhanced circum-Antarctic circulation. Structural and temporal similarity with the Greenland ice core record is evident in glacial sections and suggests a degree of interhemispheric synchroneity not predicted from bipolar ice core correlations.
An Expanded Eukaryotic Genetic Code
Authors: Chin Jason W. , Cropp T. Ashton , Anderson J. Christopher , Mukherji Mridul , Zhang Zhiwen , Schultz Peter G.
Published: August 2003

We describe a general and rapid route for the addition of unnatural amino acids to the genetic code of
Saccharomyces cerevisiae
. Five amino acids have been incorporated into proteins efficiently and with high fidelity in response to the nonsense codon TAG. The side chains of these amino acids contain a keto group, which can be uniquely modified in vitro and in vivo with a wide range of chemical probes and reagents; a heavy atom–containing amino acid for structural studies; and photocrosslinkers for cellular studies of protein interactions. This methodology not only removes the constraints imposed by the genetic code on our ability to manipulate protein structure and function in yeast, it provides a gateway to the systematic expansion of the genetic codes of multicellular eukaryotes.
Tempo and Mode of Evolutionary Radiation in Iguanian Lizards
Authors: Harmon Luke J. , Schulte James A. , Larson Allan , Losos Jonathan B.
Published: August 2003

Identification of general properties of evolutionary radiations has been hindered by the lack of a general statistical and phylogenetic approach applicable across diverse taxa. We present a comparative analytical framework for examining phylogenetic patterns of diversification and morphological disparity with data from four iguanian-lizard taxa that exhibit substantially different patterns of evolution. Taxa whose diversification occurred disproportionately early in their evolutionary history partition more of their morphological disparity among, rather than within, subclades. This inverse relationship between timing of diversification and morphological disparity within subclades may be a general feature that transcends the historically contingent properties of different evolutionary radiations.
Climate Change, Human Impacts, and the Resilience of Coral Reefs
Authors: Hughes T. P. , Baird A. H. , Bellwood D. R. , Card M. , Connolly S. R. , Folke C. , Grosberg R. , Hoegh-Guldberg O. , Jackson J. B. C. , Kleypas J. , Lough J. M. , Marshall P. , Nyström M. , Palumbi S. R. , Pandolfi J. M. , Rosen B. , Roughgarden J.
Published: August 2003

The diversity, frequency, and scale of human impacts on coral reefs are increasing to the extent that reefs are threatened globally. Projected increases in carbon dioxide and temperature over the next 50 years exceed the conditions under which coral reefs have flourished over the past half-million years. However, reefs will change rather than disappear entirely, with some species already showing far greater tolerance to climate change and coral bleaching than others. International integration of management strategies that support reef resilience need to be vigorously implemented, and complemented by strong policy decisions to reduce the rate of global warming.
Ice Core Records of Atmospheric N
2
O Covering the Last 106,000 Years
Authors: Sowers Todd , Alley Richard B. , Jubenville Jennifer
Published: August 2003

Paleoatmospheric records of trace-gas concentrations recovered from ice cores provide important sources of information on many biogeochemical cycles involving carbon, nitrogen, and oxygen. Here, we present a 106,000-year record of atmospheric nitrous oxide (N
2
O) along with corresponding isotopic records spanning the last 30,000 years, which together suggest minimal changes in the ratio of marine to terrestrial N
2
O production. During the last glacial termination, both marine and oceanic N
2
O emissions increased by 40 ± 8%. We speculate that our records do not support those hypotheses that invoke enhanced export production to explain low carbon dioxide values during glacial periods.
Hirschsprung Disease Is Linked to Defects in Neural Crest Stem Cell Function
Authors: Iwashita Toshihide , Kruger Genevieve M. , Pardal Ricardo , Kiel Mark J. , Morrison Sean J.
Published: August 2003

Genes associated with Hirschsprung disease, a failure to form enteric ganglia in the hindgut, were highly up-regulated in gut neural crest stem cells relative to whole-fetus RNA. One of these genes, the glial cell line–derived neurotrophic factor (GDNF) receptor
Ret
, was necessary for neural crest stem cell migration in the gut. GDNF promoted the migration of neural crest stem cells in culture but did not affect their survival or proliferation. Gene expression profiling, combined with reverse genetics and analyses of stem cell function, suggests that Hirschsprung disease is caused by defects in neural crest stem cell function.
Global Trajectories of the Long-Term Decline of Coral Reef Ecosystems
Authors: Pandolfi John M. , Bradbury Roger H. , Sala Enric , Hughes Terence P. , Bjorndal Karen A. , Cooke Richard G. , McArdle Deborah , McClenachan Loren , Newman Marah J. H. , Paredes Gustavo , Warner Robert R. , Jackson Jeremy B. C.
Published: August 2003

Degradation of coral reef ecosystems began centuries ago, but there is no global summary of the magnitude of change. We compiled records, extending back thousands of years, of the status and trends of seven major guilds of carnivores, herbivores, and architectural species from 14 regions. Large animals declined before small animals and architectural species, and Atlantic reefs declined before reefs in the Red Sea and Australia, but the trajectories of decline were markedly similar worldwide. All reefs were substantially degraded long before outbreaks of coral disease and bleaching. Regardless of these new threats, reefs will not survive without immediate protection from human exploitation over large spatial scales.
SCNM1, a Putative RNA Splicing Factor That Modifies Disease Severity in Mice
Authors: Buchner David A. , Trudeau Michelle , Meisler Miriam H.
Published: August 2003

The severity of many inherited disorders is influenced by genetic background. We describe a modifier interaction in C57BL/6Jmice that converts a chronic movement disorder into a lethal neurological disease. The primary mutation (med
J
) changes a splice donor site of the sodium channel gene
Scn8a
(Na
v
1.6). The modifier mutation is characteristic of strain C57BL/6Jand introduces a nonsense codon into sodium channel modifier 1 (SCNM1), a zinc finger protein and a putative splice factor. An internally deleted SCNM1 protein is also predicted as a result of exon skipping associated with disruption of a consensus exonic splicing enhancer. The effect of the modifier mutation is to reduce the abundance of correctly spliced sodium channel transcripts below the threshold for survival. Our finding that genetic variation in a putative RNA splicing factor influences disease susceptibility in mice raises the possibility that a similar mechanism modifies the severity of human inherited disorders.
A Quantum Laser Pointer
Authors: Treps Nicolas , Grosse Nicolai , Bowen Warwick P. , Fabre Claude , Bachor Hans-A. , Lam Ping Koy
Published: August 2003

The measurement sensitivity of the pointing direction of a laser beam is ultimately limited by the quantum nature of light. To reduce this limit, we have experimentally produced a quantum laser pointer, a beam of light whose direction is measured with a precision greater than that possible for a usual laser beam. The laser pointer is generated by combining three different beams in three orthogonal transverse modes, two of them in a squeezed-vacuum state and one in an intense coherent field. The result provides a demonstration of multichannel spatial squeezing, along with its application to the improvement of beam positioning sensitivity and, more generally, to imaging.
A Possible Primordial Peptide Cycle
Authors: Huber Claudia , Eisenreich Wolfgang , Hecht Stefan , Wächtershäuser Günter
Published: August 2003

α-Amino acids can undergo peptide formation by activation with carbon monoxide (CO) under hot aqueous conditions in the presence of freshly coprecipitated colloidal (Fe,Ni)S. We now show that CO-driven peptide formation proceeds concomitantly with CO-driven, N-terminal peptide degradation by racemizing N-terminal hydantoin and urea derivatives to α-amino acids. This establishes a peptide cycle with closely related anabolic and catabolic segments. The hydantoin derivative is a purin-related heterocycle. The (Fe,Ni)S-dependent urea hydrolysis could have been the evolutionary precursor of the nickelenzyme urease. The results support the theory of a chemoautotrophic origin of life with a CO-driven, (Fe,Ni)S-dependent primordial metabolism.
Loss of a Callose Synthase Results in Salicylic Acid-Dependent Disease Resistance
Authors: Nishimura Marc T. , Stein Mónica , Hou Bi-Huei , Vogel John P. , Edwards Herb , Somerville Shauna C.
Published: August 2003

Plants attacked by pathogens rapidly deposit callose, a β-1,3-glucan, at wound sites. Traditionally, this deposition is thought to reinforce the cell wall and is regarded as a defense response. Surprisingly, here we found that
powdery mildew resistant 4
(
pmr4
), a mutant lacking pathogen-induced callose, became resistant to pathogens, rather than more susceptible. This resistance was due to mutation of a callose synthase, resulting in a loss of the induced callose response. Double-mutant analysis indicated that blocking the salicylic acid (SA) defense signaling pathway was sufficient to restore susceptibility to
pmr4
mutants. Thus, callose or callose synthase negatively regulates the SA pathway.
The Crucial 80% of Life's Epic
Authors: Narbonne Guy M.
Published: August 2003

Life on a Young Planet
The First Three Billion Years of Evolution on Earth. by Andrew H. Knoll. Princeton University Press, Princeton, NJ, 2003. 287 pp. $29.95. ISBN 0-691-00978-3.

Synthesizing findings from diverse disciplines and drawing on his own research experiences and travels, Knoll describes the course of life on Earth from its beginnings to the Cambrian.
Was Newton a Newtonian?
Authors: Fara Patricia
Published: August 2003

Isaac Newton
. by James Gleick. Pantheon Books, New York, 2003. 284 pp. $22.95, C$34.95. ISBN 0-375-42233-1. Fourth Estate (HarperCollins), London, September 2003. £15. ISBN 0-00-716317-7.

Gleick provides a concise, thematically oriented introduction to Newton's life and the broad scope of his researches.
Chimeric Influenza A Viruses with a Functional Influenza B Virus Neuraminidase or Hemagglutinin
Authors: Flandorfer Astrid , García-Sastre Adolfo , Basler Christopher F. , Palese Peter
Published: August 2003

Reassortment of influenza A and B viruses has never been observed in vivo or in vitro. Using reverse genetics techniques, we generated recombinant influenza A/WSN/33 (WSN) viruses carrying the neuraminidase (NA) of influenza B virus. Chimeric viruses expressing the full-length influenza B/Yamagata/16/88 virus NA grew to titers similar to that of wild-type influenza WSN virus. Recombinant viruses in which the cytoplasmic tail or the cytoplasmic tail and the transmembrane domain of the type B NA were replaced with those of the type A NA were impaired in tissue culture. This finding correlates with reduced NA content in virions. We also generated a recombinant influenza A virus expressing a chimeric hemagglutinin (HA) protein in which the ectodomain is derived from type B/Yamagata/16/88 virus HA, whereas both the cytoplasmic and the transmembrane domains are derived from type A/WSN virus HA. This A/B chimeric HA virus did not grow efficiently in MDCK cells. However, after serial passage we obtained a virus population that grew to titers as high as wild-type influenza A virus in MDCK cells. One amino acid change in position 545 (H545Y) was found to be responsible for the enhanced growth characteristics of the passaged virus. Taken together, we show here that the absence of reassortment between influenza viruses belonging to different A and B types is not due to spike glycoprotein incompatibility at the level of the full-length NA or of the HA ectodomain.
Targeting of the
Turnip Yellow Mosaic Virus
66K Replication Protein to the Chloroplast Envelope Is Mediated by the 140K Protein
Authors: Prod'homme Delphine , Jakubiec Anna , Tournier Vincent , Drugeon Gabrièle , Jupin Isabelle
Published: August 2003

Turnip yellow mosaic virus
(TYMV), a positive-strand RNA virus in the alphavirus-like superfamily, encodes two replication proteins, 140K and 66K, both being required for its RNA genome replication. The 140K protein contains domains indicative of methyltransferase, proteinase, and NTPase/helicase, and the 66K protein encompasses the RNA-dependent RNA polymerase domain. During viral infection, the 66K protein localizes to virus-induced chloroplastic membrane vesicles, which are closely associated with TYMV RNA replication. To investigate the determinants of its subcellular localization, the 66K protein was expressed in plant protoplasts from separate plasmids. Green fluorescent protein (GFP) fusion and immunofluorescence experiments demonstrated that the 66K protein displayed a cytoplasmic distribution when expressed individually but that it was relocated to the chloroplast periphery under conditions in which viral replication occurred. The 66K protein produced from an expression vector was functional in viral replication since it could transcomplement a defective replication template. Targeting of the 66K protein to the chloroplast envelope in the course of the viral infection appeared to be solely dependent on the expression of the 140K protein. Analysis of the subcellular localization of the 140K protein fused to GFP demonstrated that it is targeted to the chloroplast envelope in the absence of other viral factors and that it induces the clumping of the chloroplasts, one of the typical cytological effects of TYMV infection. These results suggests that the 140K protein is a key organizer of the assembly of the TYMV replication complexes and a major determinant for their chloroplastic localization and retention.