bluuebunny/crossref_metadata_2025 huggingface dataset:
Models and Data on Plant-Enemy Coevolution
Authors: Bergelson Joy , Dwyer Greg , Emerson J. J.
Published: July 2002

▪ Abstract  Although coevolution is complicated, in that the interacting species evolve in response to each other, such evolutionary dynamics are amenable to mathematical modeling. In this article, we briefly review models and data on coevolution between plants and the pathogens and herbivores that attack them. We focus on “arms races,” in which trait values in the plant and its enemies escalate to more and more extreme values. Untested key assumptions in many of the models are the relationships between costs and benefits of resistance in the plant and the level of resistance, as well as how costs of virulence or detoxification ability in the enemy change with levels of these traits. A preliminary assessment of these assumptions finds only mixed support for the models. What is needed are models that are more closely tailored to particular plant-enemy interactions, as well as experiments that are expressly designed to test existing models.
Molecular Mechanisms of Lymphocyte-Mediated Cytotoxicity and Their Role in Immunological Protection and Pathogenesis In Vivo
Authors: Kägi David , Ledermann Birgit , Bürki Kurt , Zinkernagel Rolf M. , Hengartner Hans
Published: July 2002

Studies with perforin-deficient mice have demonstrated that two independent mechanisms account for T cell–mediated cytotoxicity: A main pathway is mediated by the secretion of the pore-forming protein perforin by the cytotoxic T cell, whereas an alternative nonsecretory pathway relies on the interaction of the Fas ligand that is upregulated during T cell activation with the apoptosis-inducing Fas molecule on the target cell. NK cells use the former pathway exclusively. The protective role of the perforin-dependent pathway has been shown for infection with the noncytopathic lymphocytic choriomeningitis virus, for infection with Listeria monocytogenes, and for the elimination of tumor cells by T cells and NK cells. In contrast, perforin-dependent cytotoxicity is not involved in protection against the cytopathic vaccinia virus and vesicular stomatitis virus. LCMV-induced immunopathology and autoimmune diabetes have been found to require perforin-expression. A contribution of perforin-dependent cytotoxicity to the rejection of MHC class I–disparate heart grafts has also been observed. Its absence is efficiently compensated in rejection of fully allogeneic organ or skin grafts. So far, evidence for a role of Fas-dependent cytotoxicity as a T cell effector mechanism in vivo is lacking. Current data suggest that the main function of Fas may be in regulation of the immune response and apparently less at the level of an effector mechanism in host defense. Further analysis is necessary, however, to settle this point finally.
THE STRUCTURAL BASIS OF T CELL ACTIVATION BY SUPERANTIGENS
Authors: Li Hongmin , Llera Andrea , Malchiodi Emilio L. , Mariuzza Roy A.
Published: July 2002

▪ Abstract  Superantigens (SAGs) are a class of immunostimulatory and disease-causing proteins of bacterial or viral origin with the ability to activate large fractions (5–20%) of the T cell population. Activation requires simultaneous interaction of the SAG with the Vβ domain of the T cell receptor (TCR) and with major histocompatibility complex (MHC) class II molecules on the surface of an antigen-presenting cell. Recent advances in knowledge of the three-dimensional structure of bacterial SAGs, and of their complexes with MHC class II molecules and the TCR β chain, provide a framework for understanding the molecular basis of T cell activation by these potent mitogens. These structures along with those of TCR-peptide/MHC complexes reveal how SAGs circumvent the normal mechanism for T cell activation by peptide/MHC and how they stimulate T cells expressing TCR β chains from a number of different families, resulting in polyclonal T cell activation. The crystal structures also provide insights into the basis for the specificity of different SAGs for particular TCR β chains, and for the observed influence of the TCR α chain on SAG reactivity. These studies open the way to the design of SAG variants with altered binding properties for TCR and MHC for use as tools in dissecting structure-activity relationships in this system.
SCIENCE AND TECHNOLOGY OF HIGH-TEMPERATURE SUPERCONDUCTING FILMS
Authors: Norton D. P.
Published: July 2002

▪ Abstract  The field of high-temperature superconducting thin films is reviewed, focusing on the synthesis and properties of materials that are most promising for device applications. Current materials issues that are important for emerging device applications of oxide superconducting films are discussed, with emphasis on the growth, characterization, and use of epitaxial films. The status of specific superconducting device technologies is briefly reviewed.
IC-Compatible Polysilicon Surface Micromachining
Authors: Sniegowski J. J. , de Boer M. P.
Published: July 2002

▪ Abstract  Polysilicon surface micromachining is advancing significantly and many new applications are moving beyond the prototyping phase. Recent technical successes are leading to excitement concerning various uses of devices in optical, wireless, sensor, and many other areas. Incorporation of state-of-the-art integrated circuit (IC) fabrication methods, such as planarization by chemical mechanical polishing (CMP), has enabled extension to a five-level technology. This has opened significant design space, especially for microactuator applications. Recent advancement of in situ microdiagnostics for materials and surface properties has enhanced our understanding of device reliability and performance and will allow devices to operate near well-known materials limits. New IC-compatible materials will further enhance the capabilities of microsystems in terms of performance, reliability, and operation in harsh environments.
Intestinal Transplantation
Authors: Tzakis Andreas G. , Todo Satoru , Starzl, M.D. Thomas E.
Published: July 2002

Intestinal transplantation is often the only alternative form of treatment for patients dependent on total parenteral nutrition for survival. Although a limited number of intestinal transplantations have been performed, results with FK 506 immunosuppression are comparable to those for other organ transplants. The impact of successful intestinal transplantation on gastroenterology will likely be similar to the impact of kidney and liver transplantation on nephrology and hepatology.
USE OF INTRAVENOUS IMMUNOGLOBULIN TO PREVENT OR TREAT INFECTIONS IN PERSONS WITH IMMUNE DEFICIENCY
Authors: Lee, PhD, CStat Martin L. , Gale, MD, PhD Robert Peter , Yap, MD Peng Lee
Published: July 2002

▪ Abstract  Intravenous immunoglobulin (IVIG) concentrates were originally developed as replacement therapy for individuals with primary deficiencies of the immune system. However, in various well-designed, controlled clinical trials, the ability of IVIG to prevent and possibly treat infections in patients with secondary immune deficiencies has also been considered. In this review, we briefly consider these different applications and suggest whether the data are sufficient to employ IVIG in these clinical settings.
Xenotransplantation: Problems and Prospects
Authors: Bach Fritz H.
Published: July 2002

Research in xenotransplantation has increased enormously in the last eight years. As the shortage of allogeneic organs has intensified, the possibility of using organs from pigs has become more attractive. Current data suggest that hyperacute rejection can be overcome in a clinically acceptable manner. However, additional likely rejection factors, probably related to endothelial cell activation, are being identified that likely lead to delayed xenograft rejection, a phenomenon that can occur in the absence of T lymphocytes. Reviewed here are various genetic engineering approaches that might help overcome these rejection factors, resulting eventually in a multi-transgene donor pig. Other concerns and current controversies in the field are also discussed.
Pathophysiology of Atrial Flutter
Authors: Daoud Emile G. , Morady Fred
Published: July 2002

Atrial flutter is a macroreentrant tachyarrhythmia most often contained within the right atrium. Typical atrial flutter is defined on an electrocardiogram by the classic “sawtooth” pattern of flutter waves with negative polarity in leads II, III, and aVF. In contrast to atrial fibrillation, which is sustained by multiple reentrant wavelets defined by anatomic and/or functional barriers, typical atrial flutter is sustained by a single reentrant circuit defined by anatomical barriers. The isthmus of atrial tissue bordered by the inferior vena cava and the tricuspid annulus forms a critical zone of slow conduction in the reentry circuit of atrial flutter. The goal of radiofrequency catheter ablation is to create a line of conduction block across this isthmus. This line of block interrupts the flutter circuit and often provides long-term freedom from recurrence.
Streptococcal Toxic Shock Syndrome Associated with Necrotizing Fasciitis
Authors: Stevens Dennis L.
Published: July 2002

Streptococcal toxic shock syndrome (strep TSS) with associated necrotizing fasciitis is a rapidly progressive process that kills 30–60% of patients in 72– 96 h. Violaceous bullae, hypotension, fever, and evidence of organ failure are late clinical manifestations. Thus, the challenge to clinicians is to make an early diagnosis and to intervene with aggressive fluid replacement, emergent surgical debridement, and general supportive measures. Superantigens such as pyrogenic exotoxin A interact with monocytes and T lymphocytes in unique ways, resulting in T-cell proliferation and watershed production of monokines (e.g. tumor necrosis factor α, interleukin 1, interleukin 6), and lymphokines (e.g. tumor necrosis factor β, interleukin 2, and gamma-interferon). Penicillin, though efficacious in mild Streptococcus pyogenes infection, is less effective in severe infections because of its short postantibiotic effect, inoculum effect, and reduced activity against stationary-phase organisms. Emerging treatments for strep TSS include clindamycin and intravenous gamma-globulin.
The Marfan Syndrome
Authors: Pyeritz Reed E.
Published: July 2002

▪ Abstract  The Marfan syndrome (MFS), initially described just over 100 years ago, was among the first conditions classified as a heritable disorder of connective tissue. MFS lies at one end of a phenotypic continuum, with people in the general population who have one or another of the features of MFS at the other end, and those with a variety of other conditions in between. Diagnosis of MFS and these other conditions remains based on clinical features. Mutations in FBN1, the gene that encodes fibrillin-1, are responsible for MFS and (in a few patients) other disorders in the continuum. In addition to skeletal, ocular, and cardiovascular features, patients with MFS have involvement of the skin, integument, lungs, and muscle tissue. Over the past 30 years, evolution of aggressive medical and surgical management of the cardiovascular problems, especially mitral valve prolapse, aortic dilatation, and aortic dissection, has resulted in considerable improvement in life expectancy.
COULOMB EXCITATION AT INTERMEDIATE ENERGIES
Authors: Glasmacher T.
Published: July 2002

▪ Abstract  The experimental technique of intermediate-energy Coulomb excitation allows for in-beam γ-ray spectroscopy of β-unstable nuclei far from stability with low beam intensities. Measurements of excitation energies and electric multipole moments in neutron-rich nuclei in the π(sd) shell have provided experimental data that can be compared to shell-model and microscopic calculations, extending our knowledge of the evolution of nuclear shells as the nuclear driplines are approached.
INCLUSIVE JET AND DIJET PRODUCTION AT THE TEVATRON
Authors: Blazey Gerald C. , Flaugher Brenna L.
Published: July 2002

▪ Abstract  High-energy jet distributions measured since 1992 at the Fermilab Tevatron proton-antiproton collider are presented and compared with theoretical predictions. The statistical uncertainties on these measurements are significantly reduced relative to previous results. The systematic uncertainties are comparable in size to the uncertainty in the theoretical predictions. Although some discrepancies between theory and measurements are noted, the inclusive jet and dijet cross sections can be described by quantum chromodynamics. Prospects for reducing the uncertainty in the theoretical predictions by incorporating Tevatron measurements into the proton parton distributions are discussed. Dijet distributions, in excellent agreement with quantum chromodynamics, set a 2.5-TeV limit on the mass scale of quark constituents.
NUCLEARASTROPHYSICSMEASUREMENTS WITHRADIOACTIVEBEAMS
Authors: Smith Michael S. , Rehm K. Ernst
Published: July 2002

▪ Abstract  Radioactive nuclei play an important role in a diverse range of astrophysical phenomena including the early universe, the sun, red giant stars, nova explosions, X-ray bursts, supernova explosions, and supermassive stars. Measurements of reactions with beams of short-lived radioactive nuclei can, for the first time, probe the nuclear reactions occurring in these cosmic phenomena. This article describes the astrophysical motivation for experiments with radioactive beams, the techniques to produce these beams and perform astrophysically relevant measurements, results from recent experiments, and plans for future facilities.
NUTRITIONAL PROPERTIES AND SIGNIFICANCE OF VITAMIN GLYCOSIDES
Authors: Gregory III Jesse F.
Published: July 2002

▪ Abstract  Glycosylated forms of pyridoxine, vitamin D, niacin, pantothenate, and riboflavin exist in nature, whereas glycosides of retinol and ascorbic acid are products of in vitro transglycosidation. β-Glucosides of pyridoxine (a) are prevalent in plant-derived foods, (b) contribute to human nutrition as partially available sources of vitamin B6, (c) undergo partial hydrolysis by a novel mammalian cytosolic β-glucosidase, and (d) exert a weak antagonistic effect on the utilization of free pyridoxine. Niacin exists in grains as complexed forms with low bioavailability, whereas vitamin D glycosides are toxic components of certain calcinogenic plants of importance in animal health. Glycosides of pantothenate and riboflavin appear to be minor products of mammalian metabolism. Glycosylation of retinol or other hydrophobic alcohols may facilitate glycolipid turnover, whereas a stable ascorbyl glucoside may have nutritional applications. Glycosylation of vitamins exerts widely ranging chemical and biological effects, with great nutritional and metabolic significance.
FEMTOSECOND DYNAMICS OF ELECTRONS ON SURFACES AND AT INTERFACES
Authors: Harris C. B. , Ge N.-H. , Lingle R. L. , McNeill J. D. , Wong C. M.
Published: July 2002

▪ Abstract  Two-photon photoemission is a promising new technique that has been developed for the study of electron dynamics at interfaces. A femtosecond laser is used to both create an excited electronic distribution at the surface and eject the distribution for subsequent energy analysis. Time- and momentum-resolved two-photon photoemission spectra as a function of layer thickness fully determine the conduction band dynamics at the interface. Earlier clean surface studies showed how excited electron lifetimes are affected by the crystal band structure and vacuum image potential. Recent studies of various insulator/metal interfaces show that the dynamics of excess electrons are largely determined by the electron affinity of the adsorbate. In general, electron dynamics at the interface are influenced by the substrate and adlayer band structures, dielectric screening, and polaron formation in the two-dimensional overlayer lattice.
ULTRAFASTSPECTROSCOPY OFSHOCKWAVES INMOLECULARMATERIALS
Authors: Dlott Dana D.
Published: July 2002

▪ Abstract  Recent progress in combining the techniques of time-resolved molecular spectroscopy with shock compression science is reviewed. Shock wave spectroscopy probes the response of molecules to high-speed, large-amplitude mechanical transients and is an important way of studying physical chemical phenomena that involve large-amplitude displacements. A brief discussion of the continuum model for shock compression and a molecular model for the shock front is presented. Methods for generating and detecting shock effects are reviewed. Several applications of shock spectroscopy are reviewed, including high explosives, the nanoshock technique that uses ultrafast lasers, and shock compression of biological molecules.
The Dynamics of Noble Gas—Halogen Molecules and Clusters
Authors: Rohrbacher Andreas , Halberstadt Nadine , Janda Kenneth C.
Published: July 2002

The vibrational relaxation of noble gas–halogen van der Waals clusters has been fertile territory for the development of experimental and theoretical tools for state-to-state dynamics studies. Proceeding through the various combinations of noble gas atoms and halogen molecules, one goes from “simple” direct vibrational predissociation, through sequential relaxation pathways, to the statistical intramolecular vibrational relaxation limit. In some cases the vibrational processes dominate, in others electronically nonadiabatic processes, including chemical reactions, interfere. Thus the noble gas–halogen species provide test cases for most of the dynamical processes available to more “normal” molecules. This review discusses the current state-of-the-art for such studies and points to important problems that remain to be solved.
REACTIONS ANDTHERMOCHEMISTRY OFSMALLTRANSITIONMETALCLUSTERIONS
Authors: Armentrout PB
Published: July 2002

▪ Abstract  This review discusses the reactivities and thermodynamics of small-size-specific transition metal clusters and focuses on thermodynamic information, which has not been comprehensively discussed before. Because of this focus, guided-ion-beam mass spectrometry was used to acquire much of the data. The details of this technique and the associated data analysis methods are provided. Results on the stabilities of bare transition metal clusters are provided for neutral, cationic, and anionic species. Implications for the electronic and geometrical structures are discussed, as well as the extrapolation of these values to bulk phase behavior. Detailed results for reactions of transition metal clusters with D2and the oxygen donors O2and CO2are reviewed. Available bond energies between size-specific clusters and one D atom and one and two O atoms are compiled, and their implications are evaluated and favorably compared with bulk phase analogs. Several additional thermodynamic studies of various cluster systems are also discussed.
SODIUM-COUPLED TRANSPORTERS FOR KREBS CYCLE INTERMEDIATES
Authors: Pajor Ana M.
Published: July 2002

▪ Abstract  Krebs cycle intermediates such as succinate, citrate, and α-ketoglutarate are transferred across plasma membranes of cells by secondary active transporters that couple the downhill movement of sodium to the concentrative uptake of substrate. Several transporters have been identified in isolated membrane vesicles and cells based on their functional properties, suggesting the existence of at least three or more Na+/dicarboxylate cotransporter proteins in a given species. Recently, several cDNAs, called NaDC-1, coding for the low-affinity Na+/dicarboxylate cotransporters have been isolated from rabbit, human, and rat kidney. The Na+/dicarboxylate cotransporters are part of a distinct gene family that includes the renal and intestinal Na+/sulfate cotransporters. Other members of this family include a Na+- and Li+-dependent dicarboxylate transporter from Xenopus intestine and a putative Na+/dicarboxylate cotransporter from rat intestine. The current model of secondary structure in NaDC-1 contains 11 transmembrane domains and an extracellular N-glycosylated carboxy terminus.
Maintaining the Stability of Neural Function: A Homeostatic Hypothesis
Authors: Davis Graeme W , Bezprozvanny Ilya
Published: July 2002

▪ Abstract  The precise regulation of neural excitability is essential for proper nerve cell, neural circuit, and nervous system function. During postembryonic development and throughout life, neurons are challenged with perturbations that can alter excitability, including changes in cell size, innervation, and synaptic input. Numerous experiments demonstrate that neurons are able to compensate for these types of perturbation and maintain appropriate levels of excitation. The mechanisms of compensation are diverse, including regulated changes to synaptic size, synaptic strength, and ion channel function in the plasma membrane. These data are evidence for homeostatic regulatory systems that control neural excitability. A model of neural homeostasis suggests that information about cell activity, cell size, and innervation is fed into a system of cellular monitors. Intracellular- and intercellular-signaling systems transduce this information into regulated changes in synaptic and ion channel function. This review discusses evidence for such a model of homeostatic regulation in the nervous system.
G Proteins and Olfactory Signal Transduction
Authors: Ronnett Gabriele V. , Moon Cheil
Published: July 2002

▪ Abstract  The olfactory system sits at the interface of the environment and the nervous system and is responsible for correctly coding sensory information from thousands of odorous stimuli. Many theories existed regarding the signal transduction mechanism that mediates this difficult task. The discovery that odorant transduction utilizes a unique variation (a novel family of G protein–coupled receptors) based upon a very common theme (the G protein–coupled adenylyl cyclase cascade) to accomplish its vital task emphasized the power and versatility of this motif. We now must understand the downstream consequences of this cascade that regulates multiple second messengers and perhaps even gene transcription in response to the initial interaction of ligand with G protein–coupled receptor.
PRESENTATION OF HETEROLOGOUS PEPTIDES ON PLANT VIRUSES: Genetics, Structure, and Function
Authors: Johnson J. , Lin T. , Lomonossoff G.
Published: July 2002

Capsid proteins of a number of plant viruses are permissive to genetic modifications in which foreign polypeptides are inserted in exposed loops or at their C termini. Plant viruses with these genetic alterations often grow at wild-type levels, providing gram quantities of modified viruses. Presented polypeptides studied most extensively correspond to antigenic epitopes of animal viruses and in some cases appropriately altered plant viruses generate neutralizing antibodies to the cognate animal virus when the plant virus is used as a vaccine. Structure-based analyses of these animal-plant virus chimeras have led to rational alterations to the presentation in efforts to increase the efficacy of the presented peptide.
GENETICS AND PHYSIOLOGY OF AFLATOXIN BIOSYNTHESIS
Authors: Payne G. A. , Brown M. P.
Published: July 2002

▪ Abstract  Aflatoxins are the most thoroughly studied mycotoxins. Elegant early research on the biosynthetic scheme of the pathway has allowed a molecular characterization of aflatoxin biosynthesis and its regulation. Genetic studies on aflatoxin biosynthesis in Aspergillus flavus and A. parasiticus, and sterigmatocystin biosynthesis in A. nidulans, led to the cloning of 17 genes responsible for 12 enzymatic conversions in the AF/ST pathways. Pathway-specific regulation is by a Zn(II)2Cys6 DNA-binding protein that regulates the transcription of all pathway genes. Less is known about the global factors that regulate aflatoxin biosynthesis, but there is a clear link between development and aflatoxin biosynthesis. There is also a large body of information on physiological factors involved in aflatoxin biosynthesis, but it has been difficult to understand their role in the regulation of this pathway. This chapter discusses current knowledge on the molecular biology and genetics of the pathway, and provides a summary of the physiological factors known to influence aflatoxin formation.
COMMON MECHANISMS FOR PATHOGENS OF PLANTS AND ANIMALS
Authors: Cao Hui , Baldini Regina L. , Rahme Laurence G.
Published: July 2002

▪ Abstract  The vast evolutionary gulf between plants and animals—in terms of structure, composition, and many environmental factors—would seem to preclude the possibility that these organisms could act as receptive hosts to the same microorganism. However, some pathogens are capable of establishing themselves and thriving in members of both the plant and animal kingdoms. The identification of functionally conserved virulence mechanisms required to infect hosts of divergent evolutionary origins demonstrates the remarkable conservation in some of the underlying virulence mechanisms of pathogenesis and is changing researchers' thinking about the evolution of microbial pathogenesis.
Political Consequences of Minority Group Formation
Authors: Hechter M. , Okamoto D.
Published: July 2002

Given the global trend of increasing ethnocultural diversity and the outbreak of nationalist movements based on cultural, linguistic, and territorial identities, this review focuses on social and political mechanisms that lead to the emergence of minority group collective action. This kind of collective action is seen as a function of three necessary conditions: the formation of distinctive social identities, the overcoming of free riding, and the development of institutional structures promoting the demand for greater autonomy. The article examines the debates, theories, and empirical evidence concerning these three conditions. We conclude by noting that the most important impediment to progress in this field is the relative paucity of historical and cross-national databases that are required to test many of the theories in the literature.
TIME-SERIES–CROSS-SECTIONDATA: What Have We Learned in the Past Few Years?
Authors: Beck Nathaniel
Published: July 2002

▪ Abstract  This article treats the analysis of “time-series–cross-section” (TSCS) data, which has become popular in the empirical analysis of comparative politics and international relations (IR). Such data consist of repeated observations on a series of fixed (nonsampled) units, where the units are of interest in themselves. An example of TSCS data is the post–World War II annual observations on the political economy of OECD nations. TSCS data are also becoming more common in IR studies that use the “dyad-year” design; such data are often complicated by a binary dependent variable (the presence or absence of dyadic conflict). Among the issues considered here are estimation and specification. I argue that treating TSCS issues as an estimation nuisance is old-fashioned; those wishing to pursue this approach should use ordinary least squares with panel correct standard errors rather than generalized least squares. A modern approach models dynamics via a lagged dependent variable or a single equation error correction model. Other modern issues involve the modeling of spatial impacts (geography) and heterogeneity. The binary dependent variable common in IR can be handled by treating the TSCS data as event history data.
VIACRATICAMERICA:Plessyon Foot v.Brownon Wheels
Authors: Rae Douglas W.
Published: July 2002

▪ Abstract  The United States has undergone a profound spatial reorganization over the course of the twentieth century, and it influences the working of democratic and judicial institutions profoundly. The critical feature is differential access to transportation and place, and the major instrument is of course the automobile. Other technologies—the AC electric grid most fundamental among them—have allowed a finer and finer sorting of the population into relatively homogeneous income strata. The failure of Brown v. Board of Education (1954) is a leading example of this phenomenon. The trivialization of local politics—when resources are separated from needs in a region—is another.
HUMAN ABILITIES
Authors: Sternberg Robert J. , Kaufman James C.
Published: July 2002

▪ Abstract  This chapter reviews recent literature, primarily from the 1990s, on human abilities. The review opens with a consideration of the question of what intelligence is, and then considers some of the major definitions of intelligence, as well as implicit theories of intelligence around the world. Next, the chapter considers cognitive approaches to intelligence, and then biological approaches. It proceeds to psychometric or traditional approaches to intelligence, and then to broad, recent approaches.

The different approaches raise somewhat different questions, and hence produce somewhat different answers. They have in common, however, the attempt to understand what kinds of mechanisms lead some people to adapt to, select, and shape environments in ways that match particularly well the demands of those environments.
ON KNOWING A WORD
Authors: Miller George A.
Published: July 2002

▪ Abstract  A person who knows a word knows much more than its meaning and pronunciation. The contexts in which a word can be used to express a particular meaning are a critical component of word knowledge. The ability to exploit context in order to determine meaning and resolve potential ambiguities is not a uniquely linguistic ability, but it is dramatically illustrated in the ease with which native speakers are able to identify the intended meanings of common polysemous words.
SOMESTHESIS
Authors: Craig James C. , Rollman Gary B.
Published: July 2002

▪ Abstract  In this review we focus on the perceptual and psychophysical aspects of somesthesis, although some information on neurophysiological aspects will be included as well; we look primarily at studies that have appeared since 1988. In the section on touch, we cover peripheral sensory mechanisms and several topics related to spatial and temporal pattern perception, specifically measures of spatial sensitivity, texture perception with particular emphasis on perceived roughness, complex spatial-temporal patterns, and the use of touch as a possible channel of communication. Other topics under this section include the effects of attention on processing tactile stimuli, cortical mechanisms, and the effects of aging on sensitivity. We also deal with thermal sensitivity and some aspects of haptics and kinesthesis. In the section on pain, we review work on the gate-control theory, sensory fibers, and higher neural organization. In addition, studies on central neurochemical effects and psychophysics of pain are examined.
TRUST AND DISTRUST IN ORGANIZATIONS: Emerging Perspectives, Enduring Questions
Authors: Kramer Roderick M.
Published: July 2002

▪ Abstract  Scholarly interest in the study of trust and distrust in organizations has grown dramatically over the past five years. This interest has been fueled, at least in part, by accumulating evidence that trust has a number of important benefits for organizations and their members. A primary aim of this review is to assess the state of this rapidly growing literature. The review examines recent progress in conceptualizing trust and distrust in organizational theory, and also summarizes evidence regarding the myriad benefits of trust within organizational systems. The review also describes different forms of trust found in organizations, and the antecedent conditions that produce them. Although the benefits of trust are well-documented, creating and sustaining trust is often difficult. Accordingly, the chapter concludes by examining some of the psychological, social, and institutional barriers to the production of trust.
The Development of Visual Attention in Infancy
Authors: Colombo John
Published: July 2002

▪ Abstract  Over the past decade, the study of attention in infancy has seen dramatic progress. This review delineates four attentional functions (alertness, spatial orienting, attention to object features, and endogenous attention) that are relevant to infancy and uses these functions as a framework for summarizing the developmental course of attention in infancy. Rudimentary forms of various attentional functions are present at birth, but each of the functions exhibits different and apparently dissociable periods of postnatal change during the first years of life. The role of attention in development should therefore be considered in the context of interaction among different systems at different levels of maturity during the first years of life.
The Effects of Poverty on Child Health and Development
Authors: Aber J. Lawrence , Bennett Neil G. , Conley Dalton C. , Li Jiali
Published: July 2002

Poverty has been shown to negatively influence child health and development along a number of dimensions. For example, poverty–net of a variety of potentially confounding factors—is associated with increased neonatal and post-neonatal mortality rates, greater risk of injuries resulting from accidents or physical abuse/neglect, higher risk for asthma, and lower developmental scores in a range of tests at multiple ages.

Despite the extensive literature available that addresses the relationship between poverty and child health and development, as yet there is no consensus on how poverty should be operationalized to reflect its dynamic nature. Perhaps more important is the lack of agreement on the set of controls that should be included in the modeling of this relationship in order to determine the “true” or net effect of poverty, independent of its cofactors. In this paper, we suggest a general model that should be adhered to when investigating the effects of poverty on children. We propose a standard set of controls and various measures of poverty that should be incorporated in any study, when possible.
Social Dilemmas: The Anatomy of Cooperation
Authors: Kollock Peter
Published: July 2002

The study of social dilemmas is the study of the tension between individual and collective rationality. In a social dilemma, individually reasonable behavior leads to a situation in which everyone is worse off. The first part of this review is a discussion of categories of social dilemmas and how they are modeled. The key two-person social dilemmas (Prisoner's Dilemma, Assurance, Chicken) and multiple-person social dilemmas (public goods dilemmas and commons dilemmas) are examined. The second part is an extended treatment of possible solutions for social dilemmas. These solutions are organized into three broad categories based on whether the solutions assume egoistic actors and whether the structure of the situation can be changed: Motivational solutions assume actors are not completely egoistic and so give some weight to the outcomes of their partners. Strategic solutions assume egoistic actors, and neither of these categories of solutions involve changing the fundamental structure of the situation. Solutions that do involve changing the rules of the game are considered in the section on structural solutions. I conclude the review with a discussion of current research and directions for future work.
INEQUALITY IN EARNINGS AT THE CLOSE OF THE TWENTIETH CENTURY
Authors: Morris Martina , Western Bruce
Published: July 2002

▪ Abstract  Median income in the United States has fallen and the distribution of income has grown markedly more unequal over the past three decades, reversing a general pattern of earnings growth and equalization dating back to 1929. Median trends were not the same for all groups—women's earnings generally increased—but the growth in earnings inequality has been experienced by all groups. Even white men employed full-time, year-round—traditionally the most privileged and secure group—could not escape wage stagnation and polarization. These patterns suggest research questions that go beyond conventional sociological interest in racial and gender wage gaps, refocusing attention on more general changes in labor market dynamics. The debates over the origins of the rise in US inequality cover a wide range of issues that can be roughly grouped into four categories: the changing demographics of the labor force, the impact of economic restructuring, the role of political context and institutions, and the dynamics of globalization. We review the empirical literature here, and challenge the field of sociology to reconstruct its research agenda on stratification and inequality.
Closing the “Great Divide”: New Social Theory on Society and Nature
Authors: Goldman Michael , A. Schurman Rachel
Published: July 2002

Twenty years ago, two environmental sociologists made a bold call for a paradigmatic shift in the discipline of sociology—namely, one that would bring nature into the center of sociological inquiry and recognize the inseparability of nature and society. In this essay, we review recent scholarship that seeks to meet this challenge. The respective strands of this literature come from the margins of environmental sociology and border on other arenas of social theory production, including neo-Marxism, political ecology, materialist feminism, and social studies of science. Bringing together scholars from sociology, anthropology, geography, and history, each of these strands offers what we consider the most innovative new work trying to move sociology beyond the nature/society divide.
Impact of Myocardial Ischemia and Reperfusion on Ventricular Defibrillation Patterns, Energy Requirements, and Detection of Recovery
Authors: Qin Hao , Walcott Gregory P. , Killingsworth Cheryl R. , Rollins Dennis L. , Smith William M. , Ideker Raymond E.
Published: July 2002

Background—Shocks that have defibrillated spontaneous ventricular fibrillation (VF) during acute ischemia or reperfusion may seem to have failed if VF recurs before the ECG amplifier recovers after shock. This could explain why the defibrillation threshold (DFT) for spontaneous VF appears markedly higher than for electrically induced VF.

Methods and Results—The DFT for electrically induced VF (E-DFT) was determined in 15 pigs before ischemia, followed by left anterior ascending or left circumflex artery occlusion. VF was electrically induced 20 minutes after occlusion, followed 5 minutes later by reperfusion. Whether spontaneous or electrically induced, VF during occlusion or reperfusion was treated with up to 3 shocks at 1.5×E-DFT. If all 3 shocks failed, shock strength was increased. Thirty minutes after reperfusion, the other artery was occluded and the protocol was repeated. Defibrillation was considered successful if postshock sinus/idioventricular rhythm was present for ≥30 seconds. VF recurring within 30 seconds after the shock was considered immediate or delayed if the first postshock activation complex in a rapidly restored ECG recording was VF or sinus/idioventricular rhythm, respectively. Defibrillation efficacy at 1.5×E-DFT was significantly higher for electrically induced ischemic VF (76%) than for spontaneous VF (31%). The incidence of delayed recurrence after electrically induced nonischemic (3%) or ischemic (20%) VF was significantly lower than after spontaneous VF (75%). Mean VF recurrence time after spontaneous VF was 4.6±5.3 seconds.

Conclusions—Spontaneous VF can be halted by a shock but then quickly restart before a standard ECG amplifier has recovered from postshock saturation, making it appear that the shock failed.
Beneficial Effects of Long-Term Use of the Antioxidant Probucol in Heart Failure in the Rat
Authors: Sia Ying Tung , Lapointe Nathalie , Parker Thomas G. , Tsoporis James N. , Deschepper Christian F. , Calderone Angelino , Pourdjabbar A. , Jasmin J.F. , Sarrazin J.F. , Liu Peter , Adam Albert , Butany Jagdish , Rouleau Jean L.
Published: July 2002

Background

—

Congestive heart failure (CHF) is a disease that is characterized by progressive left ventricular (LV) dysfunction and dilatation. Oxidative stress is thought to contribute to the progression of CHF, and antioxidants have been shown to have beneficial effects when started early after myocardial infarction (MI). In this study, we tested whether the powerful antioxidant probucol would attenuate progression of CHF once it was established after MI in the rat.

Methods and Results

—

Ligation of a coronary artery was used to create an MI in rats (n=266). Survivors were then randomized 20 days after MI to either probucol 61 mg · kg
−1
· d
−1
or vehicle and followed up for a total of 100 days after MI. Studies of cardiac hemodynamics, LV remodeling, cardiac apoptosis and morphology, systemic neurohumoral activation, oxidative stress, and renal function were then evaluated. Probucol improved LV function (LV maximum rate of pressure rise from 3103 to 4250 mm Hg/s,
P
<0.05, and LV end-diastolic pressure decrease from 28 to 24 mm Hg,
P
<0.05), reduced pulmonary weights, prevented right ventricular systolic hypertension, and preserved renal function compared with vehicle. Probucol also prevented LV dilatation, prevented wall thinning (1.70 versus 1.42 mm,
P
<0.05), reduced cardiac fibrosis and cardiac apoptosis, attenuated increased myocardial cell cross-sectional area, and increased scar thickness.

Conclusions

—

In chronic CHF, probucol exerts multiple beneficial morphological effects that result in better LV remodeling and function, reduced neurohumoral activation, and preserved renal function.
Heart Rate
Authors: Lantelme Pierre , Mestre Christine , Lievre Michel , Gressard Alain , Milon Hugues
Published: July 2002

Arterial stiffness is a strong determinant of cardiovascular risk. Pulse wave velocity (PWV) is an index of arterial stiffness, and its prognostic value has been repeatedly emphasized. The purpose of the present study was to assess the effect of heart rate (HR) on PWV. Twenty-two subjects with a mean age of 77.8±8.4 (SD) years and permanent cardiac pacing were studied. In each subject, PWV was measured at 5 different pacing frequencies in the same session (60, 70, 80, 90, 100 bpm), the order of the various frequencies being randomly determined. Furthermore, to test the reproducibility, a repeat measurement of PWV was obtained in one randomly selected frequency. Blood pressure (BP) was measured by conventional means at each pacing frequency. PWV appeared fairly reproducible because no significant difference was disclosed between the 2 measurements obtained at the same HR level (
P
=0.5) and both measurements were strongly correlated (
r
=0.87,
P
<0.001). No significant BP variation was observed during pacing. There was a highly significant effect of HR on PWV estimated by a one-way, within-subjects analysis of variance (
P
=0.01). This study demonstrates that HR is an important factor in the intraindividual variation of PWV in elderly subjects. This raises methodological concern about the measurement of this parameter. Standardizing PWV for HR level seems mandatory if one wants to interpret PWV changes in clinical trials or in the follow-up of patients.
Lacunar Stroke Is the Major Cause of Progressive Motor Deficits
Authors: Steinke Wolfgang , Ley Stephan C.
Published: July 2002

Background and Purpose

—

Severe motor deficits are the predominant cause of long-term disability in stroke patients. In particular, progressive hemiparesis in the initial stage after stroke onset is frequently devastating. Therefore, we attempted to define the population at risk with respect to the presumed pathogenesis.

Methods

—

Among 941 stroke patients hospitalized during a 3-year period, 92 patients (41 men, 51 women; mean age, 68 years) had a severe motor deficit (<25 of 42 points on the 7 motor items of the European Stroke Scale) resulting from brain infarcts. Risk factors, neurological examinations, comprehensive diagnostic tests, and therapy were documented. The study population was separated into patients with (group A) and without (group B) progressive motor deficits. Progression was defined as a further decrease of at least 5 points on the initial European Stroke Scale motor score during the first 5 days after stroke onset.

Results

—

Of the 92 patients, 23.9% had significant worsening of motor function with a decrease in the mean European Stroke Scale motor score from 20.3 to 12.9 points (
P
<0.01). Infarcts in group A patients were subcortical in 59.1%, whereas most infarcts were cortical in group B (61.4%,
P
<0.05). Progressive hemiparesis was also significantly associated with lacunar stroke (group A:, 59.1%; group B, 24.3%;
P
<0.01). With regard to risk factors, diagnostic studies, and neuroimaging, small-vessel disease was the predominant presumed cause of stroke in group A (63.6%,
P
<0.01), whereas infarcts in group B patients were frequently caused by embolism from cardiac or undetermined sources (61.4%,
P
<0.01). Prevalence of high-grade carotid stenosis was not significantly different between groups A and B; however, subtotal stenoses and complete internal carotid artery occlusions were found only among patients without progressive motor deficits.

Conclusions

—

Lacunar stroke caused by small-vessel disease is the major cause of progressive motor deficits, probably because of stepwise occlusion of the branches of small penetrating arteries.
Rationality in International Relations
Authors: Kahler Miles
Published: July 2002

Rationalist models have faced four persistent sets of critics as the research program of international relations has evolved. Under neorealism's structural constraints of international competition and selection, agents' rationality may appear superfluous. Psychological critics have presented neither a single theoretical alternative to rational choice nor contingent hypotheses that specify when psychological distortions of rational decision making are most likely. Both rational choice and psychological approaches must construct models of action for social entities that aggregate individuals. The rationality and individualism of beliefs is questioned by theorists who stress culture, identity, and norms as independent sources of action. Careful stipulation of scope, acknowledgment of methodological shortcomings, and precise definition of differences can serve to bridge the theoretical divide between rational choice models and their critics. Problem-centered research provides a level playing field on which theoretical competition can be established.
Brain Activities in a Skilled versus a Novice Artist: An fMRI Study
Authors: Solso Robert L.
Published: July 2002

Functional Magnetic Reso-nance Imaging (fMRI) scans of a skilled portrait artist and of a non-artist were made as each drew a series of faces. There was a dis-cernible increase in blood flow in the right-posterior parietal region of the brain for both the artist and non-artist during the task, a site normally associated with facial per-ception and processing. However, the level of activation appeared lower in the expert than in the nov-ice, suggesting that a skilled artist may process facial information more efficiently. In addition, the skilled artist showed greater acti-vation in the right frontal area of the brain than did the novice, which the author posits indicates that such an artist uses “higher-or-der” cognitive functions, such as the formation of associations and planning motor movements, when viewing and drawing a face.
A Compression-based Algorithm for Chinese Word Segmentation
Authors: Teahan W. J. , Wen Yingying , McNab Rodger , Witten Ian H.
Published: July 2002

Chinese is written without using spaces or other word delimiters. Although a text may be thought of as a corresponding sequence of words, there is considerable ambiguity in the placement of boundaries. Interpreting a text as a sequence of words is beneficial for some information retrieval and storage tasks: for example, full-text search, word-based compression, and keyphrase extraction. We describe a scheme that infers appropriate positions for word boundaries using an adaptive language model that is standard in text compression. It is trained on a corpus of presegmented text, and when applied to new text, interpolates word boundaries so as to maximize the compression obtained. This simple and general method performs well with respect to specialized schemes for Chinese language segmentation.