bluuebunny/crossref_metadata_2025 huggingface dataset:
rRNA TRANSCRIPTION AND GROWTH RATE–DEPENDENT REGULATION OF RIBOSOME SYNTHESIS IN ESCHERICHIA COLI
Authors: Gourse Richard L. , Gaal Tamas , Bartlett Michael S. , Appleman J. Alex , Ross Wilma
Published: July 2002

The synthesis of ribosomal RNA is the rate-limiting step in ribosome synthesis in bacteria. There are multiple mechanisms that determine the rate of rRNA synthesis.Ribosomal RNA promoter sequences have evolved for exceptional strength and for regulation in response to nutritional conditions and amino acid availibility. Strength derives in part from an extended RNA polymerase (RNAP) recognition region involving at least two RNAP subunits, in part from activation by a transcription factor and in part from modification of the transcript by a system that prevents premature termination. Regulation derives from at least two mechanistically distinct systems, growth rate–dependent control and stringent control. The mechanisms contributing to rRNA transcription work together and compensate for one another when individual systems are rendered inoperative.
REGULATION OF MILK LIPID SECRETION AND COMPOSITION
Authors: Neville Margaret C. , Picciano Mary Frances
Published: July 2002

▪ Abstract  Triacylglycerols make up 98% of the lipid content of milk, ranging in different species from 0 to 50% of the total milk volume. The fatty aid composition of the triacylglycerols depends on the species, the dietary fatty acid composition, and the carbohydrate-to-lipid ratio of the diet. The rate of lipid synthesis in the lactating mammary gland depends on the stage of mammary development and is decreased by fasting and starvation in ruminants and rodents but not in species that fast during lactation, such as seals and hibernating bears. Regulatory agents include insulin, prolactin, and non-esterified fatty acids. Dietary trans fatty acids may depress milk lipid synthesis under certain conditions. Evidence is presented that fatty acids may play a major regulatory role in acute changes in de novo mammary fatty acid synthesis, acting primarily on the activity of acetyl coenzyme A carboxylase.
ENVIRONMENT AND CONTAMINANTS IN TRADITIONAL FOOD SYSTEMS OF NORTHERN INDIGENOUS PEOPLES
Authors: Kuhnlein H. V. , Chan H. M.
Published: July 2002

Traditional food resources of indigenous peoples are now recognized as containing a variety of environmental contaminants which reach food species through local or long-range transport avenues. In this chapter we review the published reports of contaminants contained in traditional food in northern North America and Europe as organochlorines, heavy metals, and radionuclides. Usually, multiple contaminants are contained in the same food species. Measurement of dietary exposure to these environmental contaminants is reviewed, as are major issues of risk assessment, evaluation, and management. The dilemma faced by indigenous peoples in weighing the multiple nutritional and socioeconomic benefits of traditional food use against risk of contaminants in culturally important food resources is described.
DIETARY CONJUGATED LINOLEIC ACID IN HEALTH: Physiological Effects and Mechanisms of Action
Authors: Belury Martha A.
Published: July 2002

▪ Abstract  Conjugated linoleic acid (CLA) is a group of polyunsaturated fatty acids found in beef, lamb, and dairy products that exist as positional and stereo-isomers of octadecadienoate (18:2). Over the past two decades numerous health benefits have been attributed to CLA in experimental animal models including actions to reduce carcinogenesis, atherosclerosis, onset of diabetes, and body fat mass. The accumulation of CLA isomers and several elongated/desaturated and β-oxidation metabolites have been found in tissues of animals fed diets with CLA. Molecular mechanisms of action appear to include modulation of eicosanoid formation as well as regulation of the expression of genes coding for enzymes known to modulate macronutrient metabolism. This review focuses on health benefits, metabolism, and potential mechanisms of action of CLA and postulates the implications regarding dietary CLA for human health.
NEW EPR METHODS FOR INVESTIGATING PHOTOPROCESSES WITH PARAMAGNETIC INTERMEDIATES
Authors: Stehlik Dietmar , Möbius Klaus
Published: July 2002

▪ Abstract  Some of the significant advances in time-resolved multifrequency electron paramagnetic resonance (EPR) methods are reviewed, with the explicit focus on studies of light-driven processes and photoreactions in real time. Prominent examples are excited state electron transfer reactions with transient charge-separated radical pairs playing a central role. Paramagnetic intermediates and products are key functional states; thus EPR is the method of choice for their characterization. Photogenerated spin polarization and coherences as process-inherent features add the practical advantage of compensation in the trade-off between sensitivity and time resolution. Additionally, they provide detailed structural and dynamic information on the photoreactive system. Significance and specificity of the results achieved for charge separation in photosynthetic reaction centers and donor-acceptor model complexes indicate highly promising perspectives in photochemical research.
SPECTROSCOPY ANDHOTELECTRONRELAXATIONDYNAMICS INSEMICONDUCTORQUANTUMWELLS ANDQUANTUMDOTS
Authors: Nozik Arthur J
Published: July 2002

▪ Abstract  Photoexcitation of a semiconductor with photons above the semiconductor band gap creates electrons and holes that are out of equilibrium. The rates at which the photogenerated charge carriers return to equilibrium via thermalization through carrier scattering, cooling by phonon emission, and radiative and nonradiative recombination are important issues. The relaxation processes can be greatly affected by quantization effects that arise when the carriers are confined to regions of space that are small compared with their deBroglie wavelength or the Bohr radius of bulk excitons. The effects of size quantization in semiconductor quantum wells (carrier confinement in one dimension) and quantum dots (carrier confinement in three dimensions) on the respective carrier relaxation processes are reviewed, with emphasis on electron cooling dynamics. The implications of these effects for applications involving radiant energy conversion are also discussed.
MECHANOSENSITIVE CHANNELS OFESCHERICHIA COLI:The MscL Gene, Protein, and Activities
Authors: Sukharev Sergei I. , Blount Paul , Martinac Boris , Kung and Ching
Published: July 2002

▪ Abstract  Although mechanosensory responses are ubiquitous and diverse, the molecular bases of mechanosensation in most cases remain mysterious.MscL, a mechano-sensitive channel of large conductance of Escherichia coli and its bacterial homologues are the first and currently only channel molecules shown to directly sense mechanical stretch of the membrane. In response to the tension conveyed via the lipid bilayer, MscL increases its open probability by several orders of magnitude. In the present review we describe the identification, cloning, and first sets of biophysical and structural data on this simplest mechanosensory molecule. We discovered a 2.5-ns mechanosensitive conductance in giant E. coli spheroplasts. Using chromatographies to enrich the target and patch clamp to assay the channel activity in liposome-reconstituted fractions, we identified the MscL protein and cloned the mscL gene. MscL comprises 136 amino acid residues (15 kDa), with two highly hydrophobic regions, and resides in the inner membrane of the bacterium. PhoA-fusion experiments indicate that the protein spans the membrane twice with both termini in the cytoplasm. Spectroscopic techniques show that it is highly helical. Expression of MscL tandems and covalent cross-linking suggest that the active channel complex is a homo-hexamer. We have identified several residues, which when deleted or substituted, affect channel kinetics or mechanosensitivity. Although unique when discovered, highly conserved MscL homologues in both gram-negative and gram-positive bacteria have been found, suggesting their ubiquitous importance among bacteria.
THE PHYSIOLOGY OF PARATHYROID HORMONE-RELATED PROTEIN: An Emerging Role as a Developmental Factor
Authors: Wysolmerski J. J. , Stewart A. F.
Published: July 2002

▪ Abstract  Parathyroid hormone-related protein (PTHrP) is the agent responsible for humoral hypercalcemia of malignancy. Its pathogenic role in this syndrome is well established, and attention has focused in recent years on the elucidation of the roles played by PTHrP in normal developmental and adult physiology. This review focuses on studies of the past two years: (a) elucidation of the posttranslational processing pattern of PTHrP, the mechanisms of action of the various secretory forms of PTHrP, the role of PTHrP as an intracrine regulator of cell growth and cell death; (b) the emergence of PTHrP as a critical developmental factor in the mammary gland, epidermis, and the skeleton; and (c) the advances in understanding of the roles of PTHrP in the regulation of pancreatic islet mass, vascular smooth muscle tone and proliferation, and materno-fetal calcium transfer across the placenta.
Intracellular Ca2+ and Cl– Channel Activation in Secretory Cells
Authors: Kidd J. F. , Thorn P.
Published: July 2002

▪ Abstract  Molecular and functional evidence indicates that a variety of Ca2+dependent chloride (Cl(Ca)) channels are involved in fluid secretion from secretory epithelial cells in different tissues and species. Most Cl(Ca) channels so far characterized have an I− permeability greater than Cl−, and most are sensitive to 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS). Whole-cell Cl(Ca) currents show outward rectification. Single-channel current voltage relationships are linear with conductances ranging from 2 to 30 pS. Some Cl(Ca) channels are blocked by Ca2+-calmodulin-dependent protein kinase (CAMKII) inhibitors. Others, such as the Cl(Ca) channels of parotid and submandibular acinar cells, appear to be directly regulated by Ca2+. In native cells, the Cl(Ca) channels are located on the apical plasma membrane and activated by localized mechanisms of Ca2+ release. This positioning allows the Cl(Ca) channel to respond specifically to localized Ca2+ signals that do not invade other regions of the cell. The Cl(Ca) follows the rising phase of the Ca2+ signal, but in the falling phase hysteresis occurs where the Cl(Ca) current decays more rapidly than the underlying Ca2+. The future elucidation of the identity and mechanisms of regulation of Cl(Ca) channels will be critical to our understanding of stimulus-secretion coupling.
Chloride Secretion by the Intestinal Epithelium: Molecular Basis and Regulatory Aspects
Authors: Barrett Kim E. , Keely Stephen J.
Published: July 2002

▪ Abstract  Chloride secretion is the major determinant of mucosal hydration thoughout the gastrointestinal tract, and chloride transport is also pivotal in the regulation of fluid secretion by organs that drain into the intestine. Moreover, there are pathological consequences if chloride secretion is either reduced or increased such as in cystic fibrosis and secretory diarrhea, respectively. With the molecular cloning of many of the proteins and regulatory factors that make up the chloride secretory mechanism, there have been significant advances in our understanding of this process at the cellular level. Similarly, emerging data have clarified the intercellular relationships that govern the extent of chloride secretion. The goal of our article is to review this area of investigation, with an emphasis on recent developments and their implications for the physiology and pathophysiology of chloride transport.
Endogenous Timekeepers in Photosynthetic Organisms
Authors: Johnson Carl Hirschie
Published: July 2002

▪ Abstract  Circadian and photoperiodic timing mechanisms were first described in photosynthetic organisms. These organisms depend upon sunlight for their energy, so adaptation to daily and seasonal fluctuations in light must have generated a strong selective pressure. Studies of the endogenous timekeepers of photosynthetic organisms provide evidence for both a fitness advantage and for selective pressures involved in early evolution of circadian clocks. Photoperiodic timing mechanisms in plants appear to use their circadian timers as the ruler by which the day/night length is measured. As in animals, the overall clock system in plants appears to be complex; the system includes multiple oscillators, several input pathways, and a myriad of outputs. Genes have now been isolated from plants that are likely to encode components of the central clockwork or at least that act very close to the central mechanism. Genetic and biochemical analyses of the central clockwork of a photosynthetic organism are most highly advanced in cyanobacteria, where a cluster of clock genes and interacting factors have been characterized.
THETHREEDSOFPCR-BASEDGENOMICANALYSISOFPHYTOBACTERIA: Diversity, Detection, and Disease Diagnosis
Authors: Louws FJ , Rademaker JLW , de Bruijn FJ
Published: July 2002

▪ Abstract  The advent of molecular biology in general and the polymerase chain reaction in particular have greatly facilitated genomic analyses of microorganisms, provide enhanced capability to characterize and classify strains, and facilitate research to assess the genetic diversity of populations. The diversity of large populations can be assessed in a relatively efficient manner using rep-PCR-, AFLP-, and AP-PCR/RAPD-based genomic fingerprinting methods, especially when combined with computer-assisted pattern analysis. Genetic diversity maps provide a framework to understand the taxonomy, population structure, and dynamics of phytobacteria and provide a high-resolution framework to devise sensitive, specific, and rapid methods for pathogen detection, plant disease diagnosis, as well as management of disease risk. A variety of PCR-based fingerprinting protocols such as rDNA-based PCR, ITS-PCR, ARDRA, T-RFLPs, and tRNA-PCR have been devised, and numerous innovative approaches using specific primers have been adopted to enhance both the detection and identification of phytobacteria. PCR-based protocols, combined with computer-based analysis, have provided novel fundamental knowledge of the ecology and population dynamics of bacterial pathogens, and present exciting new opportunities for basic and applied studies in plant pathology.
New Frontiers in the Study of Dispersal and Spatial Analysis of Epidemics Caused by Species in the GenusPhytophthora
Authors: Ristaino Jean Beagle , Gumpertz Marcia L.
Published: July 2002

Diseases caused by species in the genus Phytophthora are responsible for significant economic losses on a wide range of host plants. Spatial pattern is one of the most characteristic ecological properties of a species, and reflects environmental and genetic heterogeneity and reproductive population growth acting on the processes of reproduction, dispersal, and mortality. Species of Phytophthora can be dispersed either in soil, via surface water movement down rows, from rain splash dispersal, by air, or via movement by humans or invertebrate activity. Dispersal results in patchiness in patterns of disease or inoculum in soil. In this chapter we discuss the mechanisms of dispersal of members of this important genus and describe several methods that can be used to statistically analyze data for which spatial coordinates are known. The methods include testing spatial autocorrelation for binary data or continuous data, semivariograms, and regression models for spatial data. The goal of spatial pattern analysis is to gain an understanding of the mechanisms of dispersal of propagules and to sort out the physical and biological factors that are important for spread of plant pathogens and ultimately, for disease management.
Ending Revolutions and Building New Governments
Authors: Stinchcombe Arthur L.
Published: July 2002

Revolutions may be defined as periods in which the rate of change of power positions of factions, social groups, or armed bodies changes rapidly and unpredictably. Revolutions then come to an end to the degree that political uncertainty is reduced by building enough bargains into a political structure that can maintain those bargains. The paper summarizes what we know about the structures that can produce such decreases in uncertainty: conservative authoritarianism, independence, occupation government, totalitarianism, democracy, and caudillismo. The essay describes these governmental types by how they increase certainty of power distributions in the short and medium run and so bring revolutions to an end.
Toward a Fourth Generation of Revolutionary Theory
Authors: Goldstone Jack A.
Published: July 2002

Third-generation theories of revolution pointed to the structural vulnerabilities of regimes as the basic causes of revolutions. In the last decade, critics of structural theories have argued for the need to incorporate leadership, ideology, and processes of identification with revolutionary movements as key elements in the production of revolution. Analyses of revolutions in developing countries and in communist regimes have further argued for incorporating these factors and for the inadequacy of structural theories to account for these events. Rather than try to develop a list of the “causes” of revolutions, it may be more fruitful for the fourth generation of revolutionary theory to treat revolutions as emergent phenomena, and to start by focusing on factors that cement regime stability. Weakness in those factors then opens the way for revolutionary leadership, ideology, and identification, along with structural factors such as international pressure and elite conflicts, to create revolutions.
FORECASTING FORPOLICYMAKING IN THEPOST–COLDWARPERIOD
Authors: Feder Stanley A.
Published: July 2002

▪ Abstract  Political science has given policy makers many useful methods and models for understanding continuities in the world. The utility of many models that were specified with statistical analysis is likely to be undermined as relations among variables change. Today, globalization, the rapid diffusion of technology, the internet, nongovernment organizations, environmental stresses, and population growth and migration present policy makers with unfamiliar challenges. To keep from being surprised, policy makers need methods that indicate possible outcomes but do not specify probabilities, which can be misleading. Instead, policy makers should have analytic methods that warn of discontinuities and illuminate the forces and processes shaping events. Methods based on or compatible with complexity theory seem promising. I describe two methods that can meet the needs of policy makers: Bueno de Mesquita's political expected utility models and multiple scenario analysis. But methods or theories alone will not keep policy makers from being surprised by future developments. It will also be crucial to ask the right questions.
ORIGINS AND EARLY DEVELOPMENT OF PERCEPTION, ACTION, AND REPRESENTATION
Authors: Bertenthal Bennett I.
Published: July 2002

▪ Abstract  Research relevant to the origins and early development of two functionally dissociable perceptual systems is summarized. One system is concerned with the perceptual control and guidance of actions, the other with the perception and recognition of objects and events. Perceptually controlled actions function in real time and are modularly organized. Infants perceive where they are and what they are doing. By contrast, research on object recognition suggests that even young infants represent some of the defining features and physical constraints that specify the identity and continuity of objects. Different factors contribute to developmental changes within the two systems; it is difficult to generalize from one response system to another; and neither perception, action, nor representation qualifies as ontogenetically privileged. All three processes develop from birth as a function of intrinsic processing constraints and experience.
DISCOURSE COMPREHENSION
Authors: Graesser Arthur C. , Millis Keith K. , Zwaan Rolf A.
Published: July 2002

▪ Abstract  The field of discourse processing has dissected many of the levels of representation that are constructed when individuals read or listen to connected discourse. These levels include the surface code, the propositional textbase, the referential situation model, the communication context, and the discourse genre. Discourse psychologists have developed models that specify how these levels are mentally represented and how they are dynamically built during comprehension. This chapter focuses on the meaning representations that are constructed when adults read written text, such as literary stories, technical expository text, and experimenter-generated “textoids.” Recent psychological models have attempted to account for the identification of referents of referring expressions (e.g. which person in the text does she refer to), the connection of explicit text segments, the establishment of local and global coherence, and the encoding of knowledge-based inferences.
SOCIAL CONSTRUCTIVIST PERSPECTIVES ON TEACHING AND LEARNING
Authors: Palincsar A. Sullivan
Published: July 2002

▪ Abstract  Social constructivist perspectives focus on the interdependence of social and individual processes in the co-construction of knowledge. After the impetus for understanding the influence of social and cultural factors on cognition is reviewed, mechanisms hypothesized to account for learning from this perspective are identified, drawing from Piagetian and Vygotskian accounts. The empirical research reviewed illustrates (a) the application of institutional analyses to investigate schooling as a cultural process, (b) the application of interpersonal analyses to examine how interactions promote cognition and learning, and (c) discursive analyses examining and manipulating the patterns and opportunities in instructional conversation. The review concludes with a discussion of the application of this perspective to selected contemporary issues, including: acquiring expertise across domains, assessment, educational equity, and educational reform.
PSYCHOPATHOLOGY: Description and Classification
Authors: Nathan P. E. , Langenbucher J. W.
Published: July 2002

▪ Abstract  DSM-IV's strong empirical base has yielded an instrument with good to excellent reliability and improved validity. Diagnostic reliability depends on both the clarity and validity of diagnostic criteria and the changeability of disorders over time: The reliability of schizophrenic spectrum disorders, personality disorders, and some childhood and adolescent disorders remains problematic. Findings on diagnostic validity appear paradoxical: Attempts to validate schizophrenic spectrum disorders with neurobiological and genetic-familial validators have been only modestly successful, whereas the tripartite personality trait model has differentiated a range of depressive and anxiety disorders. Research on comorbidity has identified several highly comorbid disorders (substance-related disorders, personality disorders, depression, and anxiety) as well as some adverse consequences of comorbidity. The advantages of dimensional approaches to diagnosis have largely been demonstrated conceptually; ultimate conclusions about the strengths and weaknesses of dimensional and syndromal methods await substantial additional empirical research.
Goal Theory, Motivation, and School Achievement: An Integrative Review
Authors: Covington Martin V.
Published: July 2002

The purpose of this review is to document the directions and recent progress in our understanding of the motivational dynamics of school achievement. Based on the accumulating research it is concluded that the quality of student learning as well as the will to continue learning depends closely on an interaction between the kinds of social and academic goals students bring to the classroom, the motivating properties of these goals and prevailing classroom reward structures. Implications for school reform that follow uniquely from a motivational and goal-theory perspective are also explored.
Cultural Psychopathology: Uncovering the Social World of Mental Illness
Authors: López Steven Regeser , Guarnaccia Peter J.
Published: July 2002

We review cultural psychopathology research since Kleinman’s (1988) important review with the goals of updating past reviews, evaluating current conceptualizations and methods, and identifying emerging substantive trends. Conceptual advances are noted, particularly developments in the definition of culture and the examination of both culture-specific and cultural-general processes. The contributions of the Culture and Diagnosis Task Force for DSM-IV and the World Mental Health Report are reviewed and contrasted. Selected research on anxiety, schizophrenia, and childhood disorders is examined, with particular attention given to the study of ataque de nervios, social factors affecting the course of schizophrenia, and cross-national differences in internalizing and externalizing problems in children. Within the last ten years, cultural psychopathology research has become a significant force. Its focus on the social world holds promise to make significant inroads in reducing suffering and improving people’s everyday lives.
Social Cognition: Thinking Categorically about Others
Authors: Macrae C. Neil , Bodenhausen Galen V.
Published: July 2002

In attempting to make sense of other people, perceivers regularly construct and use categorical representations to simplify and streamline the person perception process. Noting the importance of categorical thinking in everyday life, our emphasis in this chapter is on the cognitive dynamics of categorical social perception. In reviewing current research on this topic, three specific issues are addressed: (a) When are social categories activated by perceivers, (b) what are the typical consequences of category activation, and (c) can perceivers control the influence and expression of categorical thinking? Throughout the chapter, we consider how integrative models of cognitive functioning may inform our understanding of categorical social perception.
Reframing Women's Risk: Social Inequalities and HIV Infection
Authors: Zierler Sally , Krieger Nancy
Published: July 2002

▪ Abstract  Social inequalities lie at the heart of risk of HIV infection among women in the United States. As of December, 1995, 71,818 US women had developed AIDS-defining diagnoses. These women have been disproportionately poor, African-American, and Latina. Their neighborhoods have been burdened by poverty, racism, crack cocaine, heroin, and violence. To explain which women are at risk and why, this article reviews the epidemiology of HIV and AIDS among women in light of four conceptual frameworks linking health and social justice: feminism, social production of disease/political economy of health, ecosocial, and human rights. The article applies these alternative theories to describe sociopolitical contexts for AIDS' emergence and spread in the United States, and reviews evidence linking inequalities of class, race/ethnicity, gender, and sexuality, as well as strategies of resistance to these inequalities, to the distribution of HIV among women.
SUCCESSFUL BEHAVIORAL INTERVENTIONS TO PREVENT CANCER: The Example of Skin Cancer
Authors: Baum A. , Cohen L.
Published: July 2002

▪ Abstract  Important behavioral sources of risk for cancer have been identified and programs to reduce this risk have been initiated. The most heavily studied behavioral risk is tobacco use, but considerable attention has also gone to prevention of skin cancer by modifying sun exposure. Research has shown a strong link between sun exposure and skin cancer, and opportunities to prevent this cancer by changing behavior should be effective. Unlike unmodifiable sources of risk, sun exposure should be modifiable through behavioral intervention. This review considers research in this expanding area, concentrating on predictors of sun protective behaviors, modification of sun exposure, and surveillance for early signs of cancer. The elements of behavior change programs that contribute to successful intervention as well as barriers to successful behavior change and future directions for this effort are considered.
IMPLICATIONS OF THE RESULTS OF COMMUNITY INTERVENTION TRIALS
Authors: Sorensen Glorian , Emmons Karen , Hunt Mary Kay , Johnston Douglas
Published: July 2002

▪ Abstract  This paper examines the results of population-level interventions conducted in three settings: entire communities, worksites, and schools. Four major conclusions are discussed: (a) Directions for the next generation of community-based interventions include targeting multiple levels of influence; addressing social inequalities in disease risk; involving communities in program planning and implementation; incorporating approaches for “tailoring” interventions; and utilizing rigorous process evaluation. (b) In addition to randomized controlled trials, it is time to use the full range of research phases available, from hypothesis generation and methods development to dissemination research. (c) The public health research agenda may have contributed to observed secular trends by placing behavioral risk factors on the social and media agendas. (d) The magnitude of the results of community intervention trials must be judged according to their potential public health or population-level effects. Small changes at the individual level may result in large benefits at the population level.
Looking Back on “Causal Thinking in the Health Sciences”
Authors: Kaufman J. S. , Poole C.
Published: July 2002

▪ Abstract  It has now been over a quarter of a century since the publication of Mervyn Susser's Causal Thinking in the Health Sciences (1973, Oxford University Press), the first book-length treatment of causal reasoning and inference in our field. Major contributions of this work were its holistic focus on the origins of health outcomes in the context of ecologic systems and its invigoration of the literature on causal criteria in epidemiology. Although a recent resurgence of interest in social context has revivified many points made by Susser, a formal basis for causal analysis consistent with this ecologic perspective has failed to emerge in public health research. Susser's discussion of causal criteria, on the other hand, helped spur a vigorous dialogue that has persisted unabated to the present day. Although the basic outline of the criteria has evolved little, their applications, interrelations, and relative contributions to causal judgments have been the subject of continued and sometimes contentious debate.
Causal Effects in Clinical and Epidemiological Studies Via Potential Outcomes: Concepts and Analytical Approaches
Authors: Little Roderick J. , Rubin Donald B.
Published: July 2002

▪ Abstract  A central problem in public health studies is how to make inferences about the causal effects of treatments or agents. In this article we review an approach to making such inferences via potential outcomes. In this approach, the causal effect is defined as a comparison of results from two or more alternative treatments, with only one of the results actually observed. We discuss the application of this approach to a number of data collection designs and associated problems commonly encountered in clinical research and epidemiology. Topics considered include the fundamental role of the assignment mechanism, in particular the importance of randomization as an unconfounded method of assignment; randomization-based and model-based methods of statistical inference for causal effects; methods for handling noncompliance and missing data; and methods for limiting bias in the analysis of observational data, including propensity score matching and sensitivity analysis.
Assessment in Long-Term Care
Authors: Kane R. L. , Kane R. A.
Published: July 2002

▪ Abstract  Long-term care has begun to rely heavily on assessment as a basis for determining eligibility and payment for services, as well as for planning needed care. Mandated assessments have been introduced into nursing homes and will soon be required for home health care and rehabilitation. Many states use a formal structured assessment process to establish clients' eligibility for institutional or community-based care. The common feature of such assessment is attention to physical functioning, but other domains are also relevant, including affect, social function, cognition, pain and discomfort, and satisfaction. Taken together, this cluster is often referred to as quality of life. While some measures attempt to infer this information from clients' behavior, it is best obtained directly from clients' responses whenever possible. The other major component of a long term care assessment relates to obtaining information on clients' preferences and values. These data are important both for weighting the individual components of an assessment and for directly addressing preferences about the care and lifestyle available.
Assessing Change with Longitudinal and Clustered Binary Data
Authors: Neuhaus John M
Published: July 2002

▪ Abstract  Investigators often gather repeated measures on study subjects to directly measure how a subject's response changes with changes in explanatory variables. This paper focuses on several statistical issues related to assessing change with longitudinal and clustered binary data. Many popular approaches for analyzing repeated binary outcomes measure cross-sectional or between-subject, rather than within-subject, effects of covariates. The class of models known as cluster specific measures within-subject effects of covariates on responses but are subject to additional statistical complications. It is useful to decompose covariates into between- and within-cluster components. This paper describes several approaches that yield consistent estimates of the within-subject covariate effects of interest. Example data from three studies illustrate the results.
Thinking Outside the Box: Recent Advances in the Analysis and Presentation of Uncertainty in Cost-Effectiveness Studies
Authors: Briggs Andrew H. , O'Brien Bernie J. , Blackhouse Gordon
Published: July 2002

▪ Abstract  As many more clinical trials collect economic information within their study design, so health economics analysts are increasingly working with patient-level data on both costs and effects. In this paper, we review recent advances in the use of statistical methods for economic analysis of information collected alongside clinical trials. In particular, we focus on the handling and presentation of uncertainty, including the importance of estimation rather than hypothesis testing, the use of the net-benefit statistic, and the presentation of cost-effectiveness acceptability curves. We also discuss the appropriate sample size calculations for cost-effectiveness analysis at the design stage of a study. Finally, we outline some of the challenges for future research in this area—particularly in relation to the appropriate use of Bayesian methods and methods for analyzing costs that are typically skewed and often incomplete.
Modeling the Relationships Between Macro Forms of Social Control
Authors: Liska Allen E
Published: July 2002

The last decade has witnessed a plethora of macro studies of various forms of social control ranging from lynching to hospitalization. Unfortunately, these specific areas of research tend to be isolated from each other and do not constitute a recognizable literature. This paper shifts the focus of study from substantive forms of social control to theoretical issues that cut across them. One such issue is the relationship between forms of social control. First, the paper explicates this issue. Second, the paper reviews and critiques three specific research literatures on the relationships between various forms of social control that are isolated from each other although they bear on the same theoretical questions. Third, the paper argues that bivariate relationships between forms of social control are not meaningful theoretically in that they are not clearly derived from general theories of social control. Fourth, the paper argues that we should focus on the causal processes and structures that underlie the relationships between forms of social control and explicate their implications for these relationships.
WHAT HAS HAPPENED TO THE US LABOR MOVEMENT? Union Decline and Renewal
Authors: Clawson Dan , Clawson Mary Ann
Published: July 2002

▪ Abstract  For many years, US trade unions declined in union density, organizing capacity, level of strike activity, and political effectiveness. Labor's decline is variously attributed to demographic factors, inaction by unions themselves, the state and legal system, globalization, neoliberalism, and the employer offensive that ended a labor-capital accord. The AFL-CIO New Voice leadership elected in 1995, headed by John Sweeney, seeks to reverse these trends and transform the labor movement. Innovative organizing, emphasizing the use of rank-and-file intensive tactics, substantially increases union success; variants include union building, immigrant organizing, feminist approaches, and industry-wide non–National Labor Relations Board (or nonboard) organizing. The labor movement must also deal with participatory management or employee involvement programs, while experimenting with new forms, including occupational unionism, community organizing, and strengthened alliances with other social movements.
Prejudice, Politics, and Public Opinion: Understanding the Sources of Racial Policy Attitudes
Authors: Krysan Maria
Published: July 2002

This review examines the intersection of prejudice, politics, and public opinion. It focuses specifically on research that seeks to understand the sources of attitudes toward policies intended to benefit African Americans and other racial/ethnic minorities by ensuring equal treatment, providing opportunity enhancement, or striving for equal outcomes. After a review of the main patterns of white and African-American public opinion on this topic, three central theoretical interpretations of racial policy attitudes—new racism, politics and nonracial principles and values, and group conflict theories—are described and compared. The empirical evidence for each approach is assessed. Finally, directions of research that pursue a more complex view of racial policy attitudes are introduced. These include efforts to incorporate insights across theoretical domains as well as correcting an overemphasis on cognitive issues to the exclusion of affect. In addition, gaps in our understanding of “non-white” attitudes, nonprejudiced respondents, nonracial policies, and non-Americans are identified as potentially fertile ground for future research aimed at understanding the complexity of racial policy attitudes and what these can reveal about contemporary US race relations.
Social Psychology of Identities
Authors: Howard Judith A.
Published: July 2002

In this chapter I review the social psychological underpinnings of identity, emphasizing social cognitive and symbolic interactionist perspectives and research, and I turn then to key themes of current work on identity—social psychological, sociological, and interdisciplinary. I emphasize the social bases of identity, particularly identities based on ethnicity, race, sexuality, gender, class, age, and (dis)ability, both separately and as they intersect. I also take up identities based on space, both geographic and virtual. I discuss struggles over identities, organized by social inequalities, nationalisms, and social movements. I conclude by discussing postmodernist conceptions of identities as fluid, multidimensional, personalized social constructions that reflect sociohistorical contexts, approaches remarkably consistent with recent empirical social psychological research, and I argue explicitly for a politicized social psychology of identities that brings together the structures of everyday lives and the sociocultural realities in which those lives are lived.

“Identity … is a concept that neither imprisons (as does much in sociology) nor detaches (as does much in philosophy and psychology) persons from their social and symbolic universes, [so] it has over the years retained a generic force that few concepts in our field have.” ( Davis 1991 :105)

“[I]dentity is never a priori, nor a finished product; it is only ever the problematic process of access to an image of totality.” ( Bhabha 1994 :51)
Sport and Society
Authors: Washington Robert E. , Karen David
Published: July 2002

▪ Abstract  Despite its economic and cultural centrality, sport is a relatively neglected and undertheorized area of sociological research. In this review, we examine sports' articulation with stratification issues, especially race, class, and gender. In addition, we look at how the media and processes of globalization have affected sports. We suggest that sports and cultural sociologists need to attend more closely to how leisure products and practices are produced and distributed and how they intersect with educational, political, and cultural institutions. We propose the work of Bourdieu and the new institutionalism to undergird future research.
Intracranial Venous Hemodynamics Is a Factor Related to a Favorable Outcome in Cerebral Venous Thrombosis
Authors: Stolz Erwin , Gerriets Tibo , Bödeker Rolf H. , Hügens-Penzel Monika , Kaps Manfred
Published: July 2002

Background

—

In recent studies, coma, cerebral hemorrhage, older age, and infectious origin have been identified as prognostic factors in cerebral venous thrombosis (CVT). However, no studies of the prognosis of CVT have evaluated hemodynamic factors. However, it is conceivable that the presence or absence and the efficiency of venous collaterals, as well as recanalization, may have an impact on brain tissue damage and hence on the prognosis of acute CVT.

Methods

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Twenty-six patients with acute CVT (mean age, 40±15 years) were recruited prospectively. All patients were treated with intravenous heparin, followed by oral anticoagulation for 12 months, except for 2 patients who were lost to follow-up after hospital discharge. Neurological deficits were graded on the National Institute of Health Stroke Scale on admission, at hospital discharge, and at 90±14 days after admission. The functional clinical outcome was graded on the modified Rankin Scale on day 90 after admission. All patients received a venous transcranial duplex sonography (TCCS) on admission and were followed up in case of a pathological result until normalization was recorded (mean follow-up, 316±395 days; range, 13 to 1180 days).

Results

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Initial TCCS was pathological in 18 of 26 patients (69%). Four distinct venous drainage types were identified: increased drainage to the cavernous sinus and to the deep cerebral veins, flow reversal in the basal veins, and either compensatory increased or reversed flow in the transverse sinus. Initially normal venous TCCS or normalized TCCS within 90 days was significantly related to favorable outcome.

Conclusions

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TCCS can be used to evaluate venous drainage patterns in acute CVT. Furthermore, initially normal and normalization of initially pathological venous TCCS within 90 days is related to a favorable outcome in this disease.
Stroke in Lund-Orup, Sweden
Authors: Hallström Björn , Norrving Bo , Lindgren Arne
Published: July 2002

Background and Purpose

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Several studies report declining early stroke case fatality, but the findings are not consistent across geographic areas. Corresponding changes in long-term survival are less well documented. We recently reported increased stroke incidence among patients aged <75 years and stable incidence among older persons. We now report temporal trends for early and late case fatality among patients with stroke onset during 1983–1985 and 1993– 1995.

Methods

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Patients living within the Lund-Orup, Sweden, hospital district and fulfilling the diagnostic criteria for first-ever stroke during 1983–1985 (n=998) and 1993–1995 (n=1318) were followed up concerning survival status at 28 days, 1 year, and 3 years. Age and sex adjustments were performed. The possible influence of Oxfordshire Community Stroke Project (OCSP) stroke subtypes on survival was also analyzed.

Results

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Overall survival improved between the study periods (Cox proportional hazards regression: hazard ratio, 0.84; 95% confidence limits, 0.75 to 0.94;
P
=0.0019). The 28-day case fatality was 15% for stroke patients from both study periods. One-year case fatality was 31% for 1983–1985 patients and 27% for 1993–1995 patients. The corresponding figures at 3 years were 44% and 40%, respectively. In the group aged <75 years, there were no significant changes in overall survival, but survival improved significantly among patients aged ≥75 years beyond 28 days after stroke onset. OCSP stroke subtype was an independent predictor of death (
P
<0.0001).

Conclusions

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The recently observed increase in stroke incidence among patients aged <75 years was not accompanied by changing survival in that age group. However, among patients aged ≥75 years, survival improved beyond 28 days after stroke. The causes of this change in survival are unknown but may be related to improved long-term care of elderly stroke patients.
Bargaining, Enforcement, and Multilateral Sanctions: When Is Cooperation Counterproductive?
Authors: Drezner Daniel W.
Published: July 2002

Scholars and policymakers generally assume that multilateral cooperation is a necessary condition for economic sanctions to be of any use. However, previous statistical tests of this assumption have shown that sanctions are more successful with lower levels of cooperation. This puzzle calls into question established theories of economic statecraft as well as theories of international cooperation. In this article I test possible explanations for the ineffectiveness of multilateral cooperation on sanctions events using James Fearon's (1998) breakdown of cooperation into bargaining and enforcement phases as a framework for discussion The empirical results show that when multilateral economic sanctions fail, their failure is due to enforcement, not bargaining problems Without the support of an international organization, cooperating states backslide from promises of cooperation Backsliding occurs because of domestic political pressures and uncertainty about the intentions of the other sanctioning countries; backsliding causes an initial burst of cooperative behavior to decay over time. Without institutional support, cooperation is worse than useless—it is counterproductive. This result suggests that international cooperation is a more fragile equilibrium than previously thought but undercuts realist arguments that international organizations are unimportant.
The Territorial Integrity Norm: International Boundaries and the Use of Force
Authors: Zacher Mark W.
Published: July 2002

Scholars and observers of the international system often comment on the decreasing importance of international boundaries as a result of the growth of international economic and social exchanges, economic liberalization, and international regimes. They generally fail to note, however, that coercive territorial revisionism has markedly declined over the past half century—a phenomenon that indicates that in certain ways states attach greater importance to boundaries in our present era. In this article I first trace states' beliefs and practices concerning the use of force to alter boundaries from the birth of the Westphalian order in the seventeenth century through the end of World War II. I then focus on the increasing acceptance of the norm against coercive territorial revisionism since 1945. Finally, I analyze those instrumental and ideational factors that have influenced the strengthening of the norm among both Western and developing countries.