bluuebunny/crossref_metadata_2025 huggingface dataset:
The effectiveness of two form‐focused tasks in advanced EFL pedagogy
Authors: Del Pilar García Mayo María
Published: March 2003

Recent research on second language pedagogy advocates the use of form‐focused tasks which require learners to produce output collaboratively. This article reports on the results of a study carried out with high‐intermediate/advanced EFL learners who completed two form‐focused tasks (a dictogloss and a text reconstruction) collaboratively. The learners’ interaction in both tasks was codified and language‐related episodes (LREs) identified. Results indicate that (i) learners’ attention to form was task‐dependent; (ii) the linguistic features of concern were those targeted by the tasks in the case of text‐reconstruction, and (iii) high‐intermediate/advanced learners provide no justification for most of the decisions concerning LREs. The results are considered in the light of current claims about the need for classroom teachers and researchers to carefully consider the choice of task and how learners interpret and complete it.
Genetic Algorithms for Solving a Class of Constrained Nonlinear Integer Programs
Authors: Sarker Ruhul , Runarsson Thomas , Newton Charles
Published: March 2003

We consider a class of constrained nonlinear integer programs, which arise in manufacturing batch‐sizing problems with multiple raw materials. In this paper, we investigate the use of genetic algorithms (GAs) for solving these models. Both binary and real coded genetic algorithms with six different penalty functions are developed. The real coded genetic algorithm works well for all six penalty functions compared to binary coding. A new method to calculate the penalty coefficient is also discussed. Numerical examples are provided and computational experiences are discussed.
A Parallel Genetic Algorithm for Solving the Container Loading Problem
Authors: Gehring Hermann , Bortfeldt Andreas
Published: March 2003

This paper presents a parallel genetic algorithm (PGA) for the container loading problem with a single container to be loaded. The emphasis is on the case of a strongly heterogeneous load. The PGA follows a migration model. Several separate sub‐populations are subjected to an evolutionary process independently of each other. At the same time the best individuals are exchanged between the sub‐populations. The evolution of the different sub‐populations is carried out on a corresponding number of LAN workstations. The quality of the PGA is demonstrated by an extensive comparative test including well‐known reference problems and loading procedures from other authors.
Persistent and Consistent Poverty in the 1994 and 1995 Waves of the European Community Household Panel Survey
Authors: Lyte Richard , Maître Bertrand , Nolan Brian , Whelan Christopher T.
Published: March 2003

This paper focuses on the mismatch between income and deprivation measures of poverty. Using the first two waves of the European Community Household Panel Survey, a measure of relative deprivation is constructed and the overlap between the relative income poor and relatively deprived is examined. There is very limited overlap with the lowest relative income threshold. The overlap increases as the income threshold is raised, but it remains true that less than half those below the 60 percent relative income line are among the most deprived. Relative deprivation is shown to be related to the persistence of income poverty, but also to a range of other resource and need factors. Income and deprivation measures each contain information that can profitably be employed to enhance our understanding of poverty and a range of other social phenomena. This is illustrated by the manner in which both income poverty and relative deprivation are associated with self‐reported difficulty making ends meet.
MEASURING THE NEW ECONOMY: AN INTERNATIONAL COMPARATIVE PERSPECTIVE
Authors: Van Ark Bart
Published: March 2003

The advances made in the production and use of information and communication technology (ICT) during the past decades may have potentially large effects for long term economic growth. Indeed the substantial acceleration in real GDP growth in many OECD countries, but in particular in the United States, during the second half of the 1990s has led to suggestions that a “new economy” has emerged. In this new economy the old economic rules were supposed to have become invalid. For example, traditional concerns about the limits of maximum production capacity might disappear as the marginal costs of producing ICT goods and services are virtually nil. Moreover, the trade‐off between inflation and unemployment could be reduced due to a more efficient inventory management.
Are ICT Spillovers Driving the New Economy?
Authors: Stiroh Kevin J.
Published: March 2003

Some observers have raised the possibility that production spillovers and network effects associated with information and communications technology (ICT) are an important part of the “New Economy.” Across U.S. manufacturing industries, however, ICT capital appears correlated with the acceleration of average labor productivity (ALP) growth as predicted by a standard production model, but not with total factor productivity (TFP) growth as these New Economy forces imply. Once one allows for productivity differences across industries, measured TFP growth is uncorrelated with all capital inputs, including ICT capital. This provides little evidence for a New Economy story of ICT‐related spillovers or network effects driving TFP growth throughout U.S. manufacturing.
Computerization and Structural Change
Authors: Wolff Edward N.
Published: March 2003

I develop three measures of structural change on the basis of U.S. data: changes in occupational composition, changes in input–output technical coefficients, and changes in capital coefficients. Using pooled cross‐section, time‐series data for 44 industries over the period from 1970 to 1990, I find that computer investment per worker has had a positive and significant effect on the degree of occupational change and changes in input and capital coefficients.
Market Efficiency, Bounded Rationality, and Supplemental Business Reporting Disclosures
Authors: Dietrich J. Richard , Kachelmeier Steven J. , Kleinmuntz Don N. , Linsmeier Thomas J.
Published: March 2003

The AICPA Special Committee on Financial Reporting has urged disclosure of relevant forward‐looking information on risks and opportunities to supplement conventional financial statements. We conduct a laboratory market experiment to assess the effects of such disclosures on capital allocation decisions. We develop two sets of competing hypotheses regarding how capital markets react to supplemental disclosures. One set is based on the assumption of semi‐strong market efficiency, while the other posits that the bounded rationality of individual traders leads to inefficient market prices. We find that explicit disclosure of management’s best estimate of an uncertain quantity improves market efficiency, even though this disclosure is redundant with information in financial statements. Second, we find disclosure of an upper bound of management’s estimate has the potential to bias security prices upward, while informationally equivalent disclosure of both upper and lower bounds removes this bias. These results suggest that experimental market reactions to these supplemental disclosures are inconsistent with market efficiency. Supplemental analyses of individuals’ price predictions and trading behavior support our conclusion that inefficiencies are at least partially attributable to individual information processing biases.
Cost‐System Choice and Incentives—Traditional vs. Activity‐Based Costing
Authors: Mishra Birendra , Vaysman Igor
Published: March 2003

We incorporate information and managerial incentives into the analysis of a common cost‐management tool—activity‐based costing (ABC). We study the choice of a costing system in a firm where the owners contract with a manager to use either a traditional or an ABC system and make production decisions. We show that, as commonly argued in managerial‐accounting literature, in a first‐best setting with no informational asymmetries the ABC system is always preferred to the traditional costing one. However, when the firm’s manager has relevant private information, the owners’ choice of a costing system is not as clear. We demonstrate that the firm earns higher expected profits under the ABC system when the uncertainty about the manager’s private information is high. Conversely, the firm's expected profit is higher under the traditional costing system when the uncertainty surrounding the manager’s private information is low because the gross benefits of better information provided by ABC are exceeded by the additional informational rents the owners must pay the manager under this system. Our results provide a formal explanation of the coexistence of traditional and ABC systems in practice.
Discussion of Valuation of Internet Stocks—An IPO Perspective
Authors: Berger Philip G.
Published: March 2003

The discussion reviews BMS’s analysis of how summary financial data from the IPO prospectus are associated with the IPO offer price and the initial market price. The authors focus on whether the value drivers associated with these prices differ between internet and non‐internet firms, and between the offer price and the day one ending price. They conclude that there are differences in the value drivers used to value Internet versus non‐Internet firms, and further differences in the value drivers used to arrive at the offer price and the day one ending price. The review raises several concerns about these conclusions. One concern is that the reader confronts a challenge in trying to interpret the differences between the value drivers affecting the offer price and the day one ending price. The review discusses two factors for the reader to consider before interpreting these differences. The review also critiques the paper’s avoidance of disaggregated financial statement information in the value driver analyses and details several research design concerns.
The Association Between Activity‐Based Costing and Manufacturing Performance
Authors: Ittner Christopher D. , Lanen William N. , Larcker David F.
Published: March 2003

This study examines the association between activity‐based costing and manufacturing performance. Results using a cross‐sectional sample of manufacturing plants indicates that extensive ABC use is associated with higher quality levels and greater improvements in cycle time and quality, and is indirectly associated with manufacturing cost reductions through quality and cycle time improvements. However, on average, extensive ABC use has no significant association with return on assets. Instead, we find weak evidence that the association between ABC and accounting profitability is contingent on the plant’s operational characteristics.
Why Press Coverage of a Client Influences the Audit Opinion
Authors: Joe Jennifer R.
Published: March 2003

In this study I use an experiment to examine why auditors are more likely to issue going–concern opinions when the client has been the subject of negative press coverage prior to the date of the audit opinion. I find no evidence that negative press coverage increases auditors’ perceptions of legal liability, as was suggested in the prior literature. I do find, however, that negative press coverage increases auditors’ perception of a client's bankruptcy probability and this, in turn, leads auditors to modify the audit opinion. Because the press coverage presented in this study provides no new information, the results suggest that auditors react too strongly to redundant information. This over–reaction can result in inefficient allocation of audit resources and can have deleterious affects on clients. Accordingly, policy makers, auditors and their clients might be interested in how auditors’ reliance on redundant information can be reduced.
The Impact of Affective Reactions on Risky Decision Making in Accounting Contexts
Authors: Moreno Kimberly , Kida Thomas , Smith James F.
Published: March 2003

In this study we examine whether managers’ affective reactions influence their risk–taking tendencies in capital budgeting decisions. Prior research on risky decision making indicates that decision makers are often risk averse when choosing among alternatives that yield potential gains, and risk taking when the alternatives yield losses. The results reported here indicate that negative or positive affective reactions can change this commonly found risky behavior. Managers were generally risk avoiding (taking) for gains (losses) in the absence of affective reactions, as predicted by prospect theory. However, when affect was present, they tended to reject investment alternatives that elicited negative affect and accept alternatives that elicited positive affect, resulting in risk taking (avoiding) in gain (loss) contexts. The results also indicate that affective reactions can influence managers to choose alternatives with lower economic value, suggesting that managers consider both financial data and affective reactions when evaluating the utility of a decision alternative. These findings point to the importance of considering affective reactions when attempting to understand and predict risky decision making in accounting contexts.
Asian Economic Integration and Stock Market Comovement
Authors: Johnson Robert , Soenen Luc
Published: March 2003

Using daily returns from 1988 to 1998, we investigate to what degree twelve equity markets in Asia are integrated with Japan's equity market and examine the factors that affect the level of economic integration. We find that the equity markets of Australia, China, Hong Kong, Malaysia, New Zealand, and Singapore are highly integrated with the stock market in Japan. There is also evidence that these Asian markets become more integrated over time, especially since 1994. A higher import share as well as a greater differential in inflation rates, real interest rates, and gross domestic product growth rates have negative effects on stock market comovements between country pairs. Conversely, increased export share by Asian economies to Japan and greater foreign direct investment from Japan to other Asian economies contribute to greater comovement.
Claims Auditing in Automobile Insurance: Fraud Detection and Deterrence Objectives
Authors: Tennyson Sharon , Salsas‐Forn Pau
Published: March 2003

Research on insurer management of opportunism in claiming has developed in two parallel literatures. One is a theoretical literature on insurance contracting that yields predictions about the nature of optimal auditing strategies for the deterrence of fraud. The other is a literature based upon statistical analysis of claims that yields empirical strategies for the detection of fraudulent claims. This article links the two literatures by providing an empirical assessment of insurers’ auditing practices in relation to theoretical predictions. The analysis makes use of a data set on the disposition of more than 1,000 randomly selected automobile personal injury protection claims settled in the state of Massachusetts. The findings of the article are consistent with the use of rational auditing strategies by insurers and with the use of audits for both deterrence and detection.
Black Youth Violence Has a Bad Rap
Authors: Mahiri Jabari , Conner Erin
Published: March 2003

This research elicited and assessed the perspectives on violence of 41 middle‐school students attending a unique school in a low‐income section of a large northern California city. Through participation in and observation of instruction and other school‐related activities, the researchers explored ways that these students experienced and reflected on violence in their lives and in popular culture. The researchers probed ways that these students' interpreted or reflected upon rap music and hip‐hop culture, particularly its representations of violence, crime, and sex. This research provided insights into what these youth thought about violence in their lives including its depictions in electronic media. Additionally, it revealed ways that they resisted and/or critiqued some negative images and influences of hip‐hop and rap.
Toward a sociocognitive approach to second Llanguage acquisition
Authors: Atkinson Dwight
Published: March 2003

This article develops the notion of a sociocognitive perspective on second language acquisition (SLA), proposed as an alternative to the cognitivism pervading the field. By sociocognitive, I mean a view of language and language acquisition as simultaneously occurring and interactively constructed both “in the head” and “in the world.”

First, I develop a view of language and its acquisition as social phenomena—as existing and taking place for the performance of action in the (socially‐mediated) world. Second, I describe the cognitive nature of language and its acquisition, focusing especially on recent developments in connectionism. Third, I introduce sociocognitive views of language and posit a social interpretation of connectionism as bridging the gap between cognition and social action. Fourth, I discuss sociocognitive perspectives on first language acquisition. Fifth, I describe the cognitivist biases of much SLA research, then suggest how sociocognitive approaches can help overcome them. I end by considering implications of the perspective I develop in this paper.
Growth in Precursor and Reading‐Related Skills: Do Low‐Achieving and IQ‐Discrepant Readers Develop Differently?
Authors: O’Malley Kimberly J. , Francis David J. , Foorman Barbara R. , Fletcher Jack M. , Swank Paul R.
Published: March 2003

Poor readers who met low achievement and IQ‐discrepancy definitions of reading disability were compared with nonimpaired readers on their development of eight precursor and reading‐related skills to evaluate developmental differences prior to students’ identification as reading disabled. Results indicated no evidence for differences between the two groups of poor readers in the development of the eight skills, with three exceptions. Students in the IQ‐discrepant group demonstrated greater growth in letter sound knowledge, greater mean performance in visual‐motor integration at the beginning of first grade, and greater deceleration in rapid naming of letters. When compared to the nonimpaired group, low‐achieving readers demonstrated poorer performance and development in all skills, while the IQ‐discrepant readers demonstrated poorer performance and development in phonemic awareness, rapid naming of letters and objects, spelling, and word reading. The largely null results for comparisons between the two groups of poor readers challenges the validity of the two‐group classification of reading disabilities based on IQ‐discrepancy.
Effects of Hand‐Drawn and Computer‐Generated Concept Mapping on the Expository Writing of Middle School Students with Learning Disabilities
Authors: Sturm Janet M. , Rankin‐Erickson Joan L.
Published: March 2003

The purpose of this study was to examine the effects of two forms of concept mapping, hand‐drawn and computer‐generated, on the descriptive essay writing of middle‐level students with learning disabilities. Twelve eighth‐grade students composed descriptive essays under three conditions: no‐map support, hand‐map support, and computer‐map support. The essays were compared on four measures: number of words, syntactic maturity, number of T‐units, and holistic writing scores. Writing attitude was also examined. Results showed that student descriptive essays produced in the hand‐ and computer‐mapping conditions demonstrated significant increases above baseline writing samples on number of words, number of T‐units, and holistic writing scores. Carry‐over effects were observed in the no‐mapping condition and provide an indication that students may have acquired writing skills that generalized into their essay writing when not using maps. Results showed that students’ attitudes toward writing were significantly more positive in the computer‐mapping condition when compared to no‐mapping and hand‐mapping conditions.
Supporting Inclusion Through Case‐Based Vignette Conversations
Authors: Cutter Jane , Palincsar Annemarie Sullivan , Magnusson Shirley J.
Published: March 2003

The trend toward the inclusion of students with special needs in classrooms in which there is ambitious instruction places complex and multiple demands on teachers. These challenges suggest the need for research investigating powerful ways of supporting teachers to critically reflect upon and revise their instructional practices. Using interactional ethnography, we report on the process and outcomes of engaging in conversations with teachers when the purpose of the conversation is to interpret and respond to vignettes characterizing the participation and learning of students with special needs. Specifically, we focus on how teachers' thinking about the use of small‐group work changed over the course of the conversations and led to modifications in teachers' practices relative to constituting and employing small‐group work in their classrooms.
Output–Purchase Funding and Budgeting Systems in the Public Sector
Authors: Robinson Marc
Published: March 2003

Output–purchase funding systems are systems in which payments made to service delivery agencies by government are an explicit function of quantities of outputs delivered by those agencies. This article considers the feasibility of such systems for the funding of tax–financed public services. It focuses on the implications of key characteristics of public sector outputs and specifically upon the prevalence of heterogeneous outputs, the predominance of services (as opposed to physical goods), and the presence of many “contingent capacity services.”
Welfare Reform, Mississippi Style: Temporary Assistance for Needy Families and the Search for Accountability
Authors: Breaux David A. , Duncan Christopher M. , Keller C. Denise , Morris John C.
Published: March 2003

Through an examination of the implementation of the 1996 Personal Responsibility and Work Opportunity Act in the state of Mississippi, we explore the adequacy of traditional two‐actor principal‐agent theory. Using this as our lens, we suggest that the choices made by Mississippi in the area of welfare reform to privatize much of the work and to add several layers to the existing principal‐agent relationship substantially reduced accountability and the effectiveness of the monitoring systems. We conclude that not only is traditional principal‐agent theory an insufficient tool for understanding the complex interrelationship between democratic actors in this particular case, the decisions of the state of Mississippi to complicate the principal‐actor relationship through privatization also undermined the reform effort itself in ways that may have general implications for other like‐minded efforts in other policy areas.

There are those who are undermining what we are trying to achieve ...

—Bud Henry, Director of Economic Assistance, Mississippi Department of Human Services
A Comparison of Disaster Paradigms: The Search for a Holistic Policy Guide
Authors: McEntire David A. , Fuller Christopher , Johnston Chad W. , Weber Richard
Published: March 2003

The following article discusses the current emphasis and attention being given to the future of emergency management, as well as theoretical constructs designed to guide research and help practitioners reduce disaster. It illustrates that while the disaster‐resistant community, disaster‐resilient community, and sustainable development/sustainable hazards mitigation concepts provide many unique advantages for disaster scholarship and management, they fail to sufficiently address the triggering agents, functional areas, actors, variables, and disciplines pertaining to calamitous events. In making this argument, the article asserts that any future paradigm and policy guide must be built on—yet go further than—comprehensive emergency management. The article also reviews and alters the concept of invulnerable development. Finally, the article presents “comprehensive vulnerability management” as a paradigm and suggests that it is better suited to guide scholarly and practitioner efforts to understand and reduce disasters than the aforementioned perspectives.
Keeping Public Officials Accountable through Dialogue: Resolving the Accountability Paradox
Authors: Roberts Nancy C.
Published: March 2003

How can public officials be held accountable, and yet avoid the paradoxes and pathologies of the current mechanisms of accountability? The answer, claims Harmon (1995), is dialogue. But what exactly is dialogue, and how is it created? More importantly, how can dialogue ensure accountability? To address these questions, I begin with a brief description of dialogue and its basic features, distinguishing it from other forms of communication. An example illustrates how dialogue occurs in actual practice. Not only does dialogue demonstrate the intelligent management of contradictory motives and forces, it also supports Harmon’s claim that it can resolve the accountability paradox and avoid the atrophy of personal responsibility and political authority. I suggest that dialogue’s advantage outweighs its cost as a mechanism of accountability under a particular set of conditions: when public officials confront “wicked problems” that defy definition and solution, and when traditional problem–solving methods have failed, thus preventing any one group from imposing its definition of the problem or its solutions on others.
The Odyssey of Senior Public Service: What Memoirs Can Teach Us
Authors: Dobel J. Patrick
Published: March 2003

This article examines the political, psychological, and moral challenges of senior public service in the executive office. The study uses memoirs published by members of the Clinton administration. The memoirs discuss the consistent background conditions of senior public service as the personality of the chief executive, the vagaries of election cycles, the tension between staff and agency executives, and the role of the media. Senior executives adopt a number of stances to address the tension between the realities of public service and the ideals they bring. The memoirs suggest several stances, such as politics as original sin, seduction, hard work and compromise, and game. The memoirs demonstrate the high cumulative cost that public service exacts on the health and personal lives of senior officials. Finally, the study reveals a number of consistent themes about how senior appointed public officials can navigate the dilemmas and challenges of senior public service at all levels of government.
Reorganizing for National Security and Homeland Security
Authors: Newmann William W.
Published: March 2003

This article considers the post–September 11 challenges faced by the U.S. national security machinery and analyzes the relationship between the new threat environment, the United States’s role in the world, and decision–making structure. Homeland security is defined as a subset of national security. The threat of foreign terrorist organizations acting on U.S. soil should be seen in the political context of the pursuit of U.S. national interests in an often anarchic world. Two models for homeland security organizational structures are considered: a departmental model and an interagency model. The interagency model, embodied in the Homeland Security Council, is a better fit given the nature of the threat, the crucial need for coordination, and the realities of governmental decision making. The organizational challenges that may complicate the government’s preparations, decisions, and implementation of a major homeland defense mission stem from three rivalries: executive–legislative, cabinet–staff, and Homeland Security Council–National Security Council.
Institutional Investors’ Preferences for REIT Stocks
Authors: Ciochetti Brian A. , Craft Timothy M. , Shilling James D.
Published: March 2003

This article investigates the determinants of real estate investment trusts (REIT) portfolio investment and institutional REIT ownership using multivariate Tobit regressions. We contend that many institutional investors take larger positions in more liquid assets like REIT stocks, as compared with private real estate equities, because of liquidity considerations. Consistent with this contention, we find that liquidity constraints are significantly related to REIT portfolio investment by institutional investors. We also find that institutional investors have different preferences for REIT stocks than do other investors; they generally prefer larger, more liquid REIT stocks.
The Heartland Responds to Terror: Volunteering After the Bombing of the Murrah Federal Building
Authors: St. John Craig , Fuchs Jesse
Published: March 2003

Objective. We examine volunteering to support the relief effort after the bombing of the Murrah Federal Building. We address two issues: (1) how widespread was volunteering and what forms did it take, and (2) does Wilson and Musick’s (1997a) “integrated theory of volunteer work” help to explain variation in volunteering in this disaster situation? Methods. We use data from the 1996 Oklahoma City Survey (OKC Survey). The 1996 OKC Survey is based on a random sample of the adult population of Oklahoma City and was administered 10 months after the bombing. Results. Nearly 75 percent of the sample respondents volunteered to support the relief effort in at least one way; giving money and donating nonprofessional goods or services were the two most prevalent volunteer activities. Socioeconomic status, knowing someone killed or injured in the bombing, belonging to voluntary organizations before the bombing, and being affiliated with a religious denomination were predictors of volunteering, depending on the type of volunteer activity considered. Conclusions. The magnitude of volunteering after the Murrah Building bombing was in line with volunteer efforts after other disasters. The integrated theory of volunteer work is a useful framework for studying volunteering after disasters.
Sociotropes, Systematic Bias, and Political Failure: Reflections on the Survey of Americans and Economists on the Economy
Authors: Caplan Bryan
Published: March 2003

Objectives. Economic models of politics typically make two assumptions about voters: first, their motives are egocentric, not sociotropic; second, their beliefs are rational, not subject to systematic bias. Political scientists have presented strong evidence against the first assumption (Mansbridge, 1990), but have become increasingly willing to accept the second (Page and Shapiro, 1992; Marcus and Hanson, 1993). This article tests these two assumptions, then explores the tests’ broader implications. Methods. I use the Survey of Americans and Economists on the Economy to test for egocentricity of motivation and rationality of belief. Results. Both standard assumptions fail for the case where the economic approach would seemingly be most relevant: economic beliefs. Conclusions. This is not necessarily cause for greater optimism about the efficiency of democracy: sociotropic voters with biased economic beliefs are more likely to produce severe political failures than are selfish voters with rational expectations.
One Person—No Vote; One Vote; Two Votes: Voting Methods, Ballot Types, and Undervote Frequency in the 2000 Presidential Election
Authors: Bullock, III Charles S. , Hood, III M. V.
Published: March 2003

Objectives. Political science long ignored the actual mechanics of voting—until the 2000 presidential contest. This research note offers a systematic empirical inquiry into the potential effects of various voting methods and electorate–specific variables on the rate at which citizens register a preference via the act of voting. Methods. Voting methods were analyzed in relation to the rate of undervotes recorded in Georgia’s 159 counties during the 2000 general election using a set of multivariate models. Results. Lever machines and fill in the oval optical scan ballots are associated with lower rates of undervoting. Counties with large numbers of new registrants, lower education levels, and a higher proportion of African–American voters were found to have higher error rates. Conclusions. The results of this study provide strong evidence that voting methods and ballot types, as well as electorate–specific characteristics, are key factors in determining the error rate associated with the process of voting at the county level.
Does Immigration Help or Harm Children’s Health? The Mayan Case
Authors: Smith Patricia K. , Bogin Barry , Varela–Silva M. Inês , Orden Bibiana , Loucky James
Published: March 2003

Objective. We explore how the health, as measured by physical growth, of children in Guatemalan Maya families is impacted by immigration to the United States. Methods. We analyze anthropometric data on Maya children in Guatemala and in the United States. In addition, we use survey data from the Maya–American children and their parents about lifestyle and SES to examine the factors associated with overweight and obesity. Results. The Maya–American children are on average 10 centimeters taller, indicating better health. However, nearly half the Maya–American children are overweight and 42 percent are obese. Children who report watching TV or playing computer games as one of their favorite leisure time activities face a higher chance of being overweight. Conclusion. Immigration from Guatemala to the United States improves the health of children in that they generally grow taller. However, immigration also raises the risk of weight problems, increasing the likelihood of health problems such as hypertension and diabetes.
Empirical Analysis of the Yield Curve: The Information in the Data Viewed through the Window of Cox, Ingersoll, and Ross
Authors: Lamoureux Christopher G. , Witte H. Douglas
Published: March 2003

This paper uses recent advances in Bayesian estimation methods to exploit fully and efficiently the time‐series and cross‐sectional empirical restrictions of the Cox, Ingersoll, and Ross model of the term structure. We examine the extent to which the cross‐sectional data (five different instruments) provide information about the model. We find that the time‐series restrictions of the two‐factor model are generally consistent with the data. However, the model's cross‐sectional restrictions are not. We show that adding a third factor produces a significant statistical improvement, but causes the average time‐series fit to the yields themselves to deteriorate.
CK2 Protein Kinase Is Stimulated and Redistributed by Functional Herpes Simplex Virus ICP27 Protein
Authors: Koffa Maria D. , Kean Joy , Zachos George , Rice Stephen A. , Clements J. Barklie
Published: March 2003

It has been shown previously (S. Wadd, H. Bryant, O. Filhol, J. E. Scott, T.-T. Hsieh, R. D. Everett, and J. B. Clements, J. Biol. Chem. 274:28991-28998, 2000) that ICP27, an essential and multifunctional herpes simplex virus type 1 (HSV-1) protein, interacts with CK2 and with heterogeneous ribonucleoprotein K (hnRNP K). CK2 is a pleiotropic and ubiquitous protein kinase, and the tetrameric holoenzyme consists of two catalytic α or α′ subunits and two regulatory β subunits. We show here that HSV-1 infection stimulates CK2 activity. CK2 stimulation occurs at early times after infection and correlates with redistribution of the holoenzyme from the nucleus to the cytoplasm. Both CK2 stimulation and redistribution require expression and cytoplasmic accumulation of ICP27. In HSV-1-infected cells, CK2 phosphorylates ICP27 and affects its cytoplasmic accumulation while it also phosphorylates hnRNP K, which is not ordinarily phosphorylated by this kinase, suggesting an alteration of hnRNP K activities. This is the first example of CK2 stimulation by a viral protein in vivo, and we propose that it might facilitate the HSV-1 lytic cycle by, for example, regulating trafficking of ICP27 protein and/or viral RNAs.
GENERALIZED NONCOMMUTATIVE SUPERALGEBRAS
Authors: ABBASPUR REZA
Published: March 2003

Using the notions of gauge symmetry and gauge connection on ordinary superspaces, we derive a class of generalized supertranslation algebras in the case of N = 1, D = 2 Euclidean superspace with a U(1) gauge group. This generalizes the ordinary algebra by inclusion of some additional bosonic and fermionic operators which are interpreted as the generators of the U(1) gauge symmetry on superspace. The generalized superalgebra closes only for very particular configurations of the gauge connection superfield. This provides a unified framework for a variety of generalizations of the ordinary superalgebra such as its central extension and its noncommutative deformation found in an earlier work.
REFLECTIONS ON AMPLITUDE ANALYSIS
Authors: Donnachie A.
Published: March 2003

The role of analyticity in partial wave analysis is emphasized and the concept of two-component duality is introduced and illustrated with examples from π N scattering. An intrinsic n-fold ambiguity in partial wave analysis is discussed in terms of Barrelet zeros and techniques for removing the ambiguities are outlined. The problems of resonance backgrounds are touched upon.
MODELING AND CHARACTERIZING DETERMINISTIC COMPONENT OF HEART RATE VARIABILITY BY CLUSTER-WEIGHTED FILTERING
Authors: HE ZHENYA , PEI WENJIANG , YANG LUXI , HULL STEPHEN S. , CHEUNG JOHN Y.
Published: March 2003

The control of heart rate is primarily due to the function of the human autonomic nervous system. This process is deterministic but highly nonlinear. Due to the rapid response of the central nervous system, the actual heart rate is adjusted on a beat-to-beat basis. In this study, we propose the use of the cluster-weighted filtering (CWF) method to model the underlying deterministic mechanism of the variation of heart intervals. On a gross scale, a Gaussian network is used for function approximation to model the overall complex nonlinear dynamics of heart rate variability. At the same time, a noise reduction strategy based on Bayesian theory is used to eliminate the effects of noise on a finer scale. The algorithm iteratively models the nonlinear dynamics and reduces the noise components simultaneously. The proposed algorithm has been applied to 19 real data sets selected for analysis. The system dynamics was modeled from the experimental data sets. Based on the criterion for reconstruction used in this letter, the results suggested that the underlying deterministic dynamics could be reconstructed. A number of additional tests such as surrogate data and the largest Lyapunov exponent analyses were also carried out. Results confirmed that heart rate variability is a highly nonlinear process. It is further observed that the underlying deterministic mechanism of cardiac dynamics is highly sensitive to the initial conditions.
COMBINATORIAL AUCTIONS MATHEMATICAL FORMULATIONS AND OPEN ISSUES
Authors: GAVISH BEZALEL
Published: March 2003

The widespread use of the Internet fostered the establishment of hundreds of sites that support on-line auctions of products and services, some of which also support combinatorial auctions. Finding the optimal combination of winning bids in combinatorial auctions is a difficult task. This paper presents the combinatorial auction problem, classifies combinatorial auctions by the different procedures used during the bidding process, presents some of the applications of combinatorial auctions, and develops mathematical models of combinatorial auctions. The mathematical models are used to identify some of the problem properties and prove that winner determination in combinatorial auctions has the same level of difficulty as solving the allocation problem facing an auctioneer. The paper concludes with the discussion on some of the complexities involved in combinatorial auctions.
Visually guided injection of identified reticulospinal neurons in zebrafish: A survey of spinal arborization patterns
Authors: Gahtan Ethan , O'Malley Donald M.
Published: March 2003

We report here the pattern of axonal branching for 11 descending cell types in the larval brainstem; eight of these cell types are individually identified neurons. Large numbers of brainstem neurons were retrogradely labeled in living larvae by injecting Texas‐red dextran into caudal spinal cord. Subsequently, in each larva a single identified cell was injected in vivo with Alexa 488 dextran, using fluorescence microscopy to guide the injection pipette to the targeted cell. The filling of cells via pressure pulses revealed distinct and often extensive spinal axon collaterals for the different cell types. Previous fills of the Mauthner cell had revealed short, knob‐like collaterals. In contrast, the two segmental homologs of the Mauthner cell, cells MiD2cm and MiD3cm, showed axon collaterals with extensive arbors recurring at regular intervals along nearly the full extent of spinal cord. Furthermore, the collaterals of MiD2cm crossed the midline at frequent intervals, yielding bilateral arbors that ran in the rostral‐caudal direction. Other medullary reticulospinal cells, as well as cells of the nucleus of the medial longitudinal fasciculus (nMLF), also exhibited extensive spinal collaterals, although the patterns differed for each cell type. For example, nMLF cells had extensive collaterals in caudal medulla and far‐rostral spinal cord, but these collaterals became sparse more caudally. Two cell types (CaD and RoL1) showed arbors projecting ventrally from a dorsally situated stem axon. Additional cell‐specific features that seemed likely to be of physiological significance were observed. The rostral‐caudal distribution of axon collaterals was of particular interest because of its implications for the descending control of the larva's locomotive repertoire. Because the same individual cell types can be identified from fish to fish, these anatomical observations can be directly linked to data obtained in other kinds of experiments. For example, 9 of the 11 cell types examined here have been shown to be active during escape behaviors. J. Comp. Neurol. 459:186–200, 2003. © 2003 Wiley‐Liss, Inc.
Efficient gene delivery into murine ovarian cells by intraovarian injection of plasmid DNA and subsequent in vivo electroporation
Authors: Sato Masahiro , Tanigawa Maya , Kikuchi Natsuko , Nakamura Shingo , Kimura Minoru
Published: March 2003

Summary: We describe the use of direct injection of circular plasmid DNA and subsequent in vivo electroporation (EP) for efficient gene delivery to the ovarian cells, including follicular cells and oocytes of mice. When Trypan blue (TB) was injected into the central portion of an ovary by a glass micropipette, rapid dispersion of TB to each preantral and antral follicle was observed. Injections of lacZ‐expressing plasmid DNA and subsequent in vivo EP resulted in transfection of follicles with efficiencies ranging from 8–60%, together with cells in the thecal portion of the ovary. Of the lacZ‐positive follicles, some oocytes were also positive for lacZ activity. These findings suggest that a solution introduced inside the ovary is rapidly dispersed to each follicle. With this technique, we expect great progress in genetic engineering in murine ovary. genesis 35:169–174, 2003. © 2003 Wiley‐Liss, Inc.
CD4 segregates into specific detergent‐resistant T‐cell membrane microdomains
Authors: Millán J. , Cerny J. , Horejsi V. , Alonso M.A.
Published: March 2003

In T cells, glycolipids, glycoproteins attached to the membrane via a glycosylphosphatidylinositol (GPI) anchor, and Src‐like tyrosine kinases are highly enriched in a membrane fraction resistant to solubilization by nonionic detergents. We have investigated the distribution of CD4 in T‐cell membranes and found that approximately 10% of the CD4 co‐receptor is associated with detergent‐insoluble membrane microdomains, whilst the remaining 90% is in soluble membranes. Moreover, approximately 60% of the “insoluble CD4” is present in membrane microdomains containing GPI‐anchored proteins and high glycolipid‐dependent kinase activity, whereas the remaining 40% displays no association with GPI‐anchored proteins and lacks glycolipid‐associated kinase activity. These results indicate that CD4 segregates at least into three different membrane microenvironments: 1) soluble membranes; 2) insoluble membrane microdomains containing GPI‐anchored proteins; and 3) insoluble membrane microdomains devoid of GPI‐anchored proteins. The level of CD4 in insoluble membranes was not modified upon triggering activation by T‐cell receptor‐crosslinking but detectable amounts of CD3 subunits were recruited into these specialized membranes under those conditions. The physical separation of CD4 into different membrane microenvironments raises the possibility of that some of the multiple functions of CD4 might segregate into distinct types of lipid microenvironment. The fact that components of T‐cell receptor/CD3 complex were recruited into insoluble membranes upon stimulation is consistent with the CD4 present in this membrane fraction might participate in T‐cell receptor‐triggered activation events.
HLA class I allele distributions in six Pacific/Asian populations: evidence of selection at the HLA‐A locus
Authors: Bugawan T.L. , Mack S.J. , Stoneking M. , Saha M. , Beck H.P. , Erlich H.A.
Published: March 2003

The distributions of HLA‐A alleles in six Pacific/Asian populations, Malay, Papua New Guinea (PNG) Highlands, two Indonesian groups, and two PNG Lowland groups, as well as the distribution of the HLA‐B alleles in the PNG Highlands population, were determined using polymerase chain reaction (PCR) immobilized sequence‐specific oligonucleotide (SSO) probe typing methods. The allele frequency distributions at the HLA class II loci, DRB1, DQB1 and DPB1 were also determined by PCR/SSO methods in an additional study of the same populations. In most of these populations, the HLA‐A*2402 allele was the most frequent, attaining a frequency of 0.78 in the PNG Highlands. A*1101 was the next most frequent allele, followed in frequency by the *3401 allele. The HLA‐B*1506, *4001, *5601 and *5602 alleles comprised 73% of the allele diversity at the B‐locus in the PNG Highlands. Two previously unreported HLA‐A alleles were identified in Indonesians and Malays, based on novel probe reactivity patterns. Cloning and sequencing identified these as A*1104 and *2410. Sequence comparisons show that these new alleles differ at codon 187 from their putative parental alleles (*1101 and *2403) by dinucleotide changes in the first two codon positions. These changes involve a Thr to Arg (CG to AC) and an Arg to Thr substitution (AC to CG) at position 187; residues at this position participate in pocket A of the peptide binding groove. Comparison of the HLA‐A allele frequency distributions indicate that Malays are the most diverse (heterozygosity (h)=0.88) and the PNG Highlanders are, by far, the least diverse (h=0.37) of the groups studied. However, the diversity of B‐locus alleles in the PNG Highlanders (h=0.91) was greater than that observed at the A‐locus of any of the populations reported here. The remarkably high allele frequency of A*2402 in the PNG Highlands could reflect founder effects and population bottlenecks, genetic drift, or positive directional selection. The distribution of the HLA‐B locus alleles and class II alleles, as well as mtDNA sequence data in the PNG Highlands indicates a reasonably high level of diversity at other loci, arguing that the high frequency of A*2402 cannot be attributed entirely to founder effects, bottlenecks, or drift and suggests the operation of positive selection for the A*2402 allele in this population Note.