bluuebunny/crossref_metadata_2025_split huggingface dataset:
GENETICS OF CAMPYLOBACTER AND HELICOBACTER
Authors: Taylor Diane E. 
Published: July 2003

This article reviews the current state of genetic analysis of Campylobacter and Helicobacter. Chromosomal genes cloned from Campylobacter and Helicobacter species are listed along with the method used to identify the cloned gene. Campylobacter plasmid genes that have been cloned and expressed in Escherichia coli and that specify resistance to tetracycline, kanamycin, or chloramphenicol are presented. This review also examines our current knowledge of genetic exchange in Campylobacter, including conjugative plasmid transfer, natural transformation, electrotransformation, and bacteriophage transduction. In Helicobacter, natural transformation has been described and both plasmids and bacteriophages have been observed. Plasmid cloning vectors have been constructed for Campylobacter. Available vectors are discussed and restriction maps of some useful vectors that we have constructed are included. The genome sizes of C. jejuni and C. coli are approximately 1.7 megabases (Mb), whereas the genome size of H. pylori ranges from l.60 to l.73 Mb. The positions of various genes on the C. jejuni and C. coli genome maps have been determined using both homologous and heterologous DNA probes. Genomic maps of these organisms are presented.
Some Spectroscopic Reminiscences
Authors: Klemperer William 
Published: July 2003

We review a number of essentially spectroscopic problems in this personal account. The structure of high-temperature species remains a topic of considerable broad interest. The binary fluorides of essentially every element are stable as the isolated gas-phase molecular species. As such they provide a means of comparing bonding with the entire periodic table. The structural characterization of the binary fluorides, although still incomplete, has provided a considerable insight into a variety of bonding types. The formation of molecules in the interstellar medium has been a model for abiotic synthesis of complex species. A kinetic model based upon ion­molecule reactions as the predominant reaction class appears to fit many of the observations, such as the polyatomic ion HCO+. The high abundance of carbon-chain compounds is attributed to the efficient formation of C+ by the reaction CO+He+ →C+ +O+He. The spectroscopic characterization of weakly bonded species has led to a detailed knowledge of intermolecular potentials. The dynamics of molecular complexes has been frequently novel. In particular the concurrent breaking and making of weak bonds is observed in many species
External Infrared Reflection Absorption Spectrometry of Monolayer Films at the Air-Water Interface
Authors: Mendelsohn Richard , Brauner Joseph W. , Gericke Arne 
Published: July 2003

The theory and practice of external infrared reflection absorption spectrometry (IRRAS) as applied to monomolecular films at the air-water interface are reviewed. The observed IR frequencies for films of amphiphilic species provide information about the conformational states of the hydrocarbon chains and the hydrogen bonding and ionization states of the polar head groups, under conditions of controlled surface pressure. Determination of molecular orientation is also feasible and requires detailed consideration of the reflection-absorption properties of the three­ phase (air-monolayer-water) system. Current theoretical approaches are described. Applications of IRRAS to the study of single- and double-chain amphiphiles and proteins are reviewed, and initial excursions into biochemistry (interfacial enzyme catalysis) and physiology (pulmonary surfactant function) are reported.
Rhapsody in Science
Authors: Scholander P. F. 
Published: July 2003

Dear readers, I find it quite shocking to have reached a stage in life when I am supposed to be retrospective. Like a vulgar streaker I shall expose myself in the limelight. I frequently ask myself how has it been possible to live such an exciting and happy life being such an irregular and irresponsible person? My Norwegian mother was an accomplished pianist. I have just noticed in her copy of Speemans' encyclopedia, Goldenes Buch der Musik (1909), that she underlined the following advice to prospective musicians (which in my opinion applies to scientists as well): “Only such a person can I advise to become an artist, who from pure love of art itself, through internal urge and need—unconcerned about spectacular successes—desires to devote his life to it and therein to find his fulfillment and his happiness.”
Absorption and Translocation of Plant Regulators
Authors: van Overbeek J. 
Published: July 2003

Naturally-occurring auxins, of which indoleacetic acid is the best known example, have a striking apex-to-base polar transport. This may have led to the belief that all plant regulators have a rather specific mode of absorption and of transport. However, since plant regulators now (5) include a wide variety of organic compounds this seems most unlikely. Many of the phenomena which are involved in the absorption and translocation of regulators in plants are well known. However, a unified picture seems lacking. It is a rather new field, which one will not find discussed in standard texts of plant physiology. The significance of this subject is more than academic. In recent years sprays have been applied to plants for a multitude of practical purposes (106a). New techniques have helped in the understanding of the principles of absorption and translocation. Enzymatic digestion is used for the isolation of the plant cuticle, a principal barrier through which materials must pass. Electron microscopy is showing its detailed structure. Radioactive tracers and chromatography have been useful in the microanalysis of materials, revealing their distribution on and in the plant. The author has attempted to outline the broad principles involved.
Training in Work Organizations
Authors: Goldstein Irwin L. 
Published: July 2003

This review examines issues and topics concerning systematic modes of instruction designed to produce environments that shape behavior to satisfy stated objectives. Training here is defined as the acquisition of skills, concepts, or attitudes that results in improved performance in an on-the-job environment. Even a cursory inspection of this review displays the diverse nature of literature in this field which includes such topics as: need assessment techniques, evaluation methodology, and particular modes of instruction; in addition, there are topics with social and political implications such as training for second careers and training hard-core unemployed youth. This is the first examination of the topic in this series since J. P. Campbell's (1971) review. Computer searches covering the period since his review produced over 3000 references from the Educational Resources Information Center and Psychological Abstracts bibliographic data bases. The resulting eye strain was partially alleviated by a set of informal decision rules which helped determine the materials read and considered for this review. First, consistent with the definition of training, the selection process emphasized topics related to systematic instruction designed to produce transfer in work organizations. Thus, topics that emphasized the development of basic principles in learning (e.g. massed vs spaced learning) were excluded unless the research was directly relevant to an instructional program for training purposes. Also, topics such as organization development which have implications for quality of work life and institutional effectiveness that extend beyond the considerations of most training programs were excluded as a separate topic. However, there is an attempt to describe relevant literature from a wide variety of disciplines which touch on many important developments. Therefore, this review examines discussions on such topics as criterion development, found in the educational psychology literature; need assessment methodology, developed in vocational education; and instructional systems approaches, evaluated in military environments. This review also attempts to conceptualize training issues broadly. It would have been possible to complete this article by examining only the different types of training approaches utilized. However, such an approach would have excluded many important issues that should affect our understanding of training as a system within a work organization. For example, it is possible to consider training as part of the socialization process. Also, it is important to consider training and its evaluation as an intervention which affects the lives of people in work organizations. This review attempts to provide such a perspective as well as examine the more traditional topics.
Workers' Compensation in the United States: High Costs, Low Benefits
Authors: Boden L. I. 
Published: July 2003

Studies suggest that income replacement is low for many workers with serious occupational injuries and illnesses. This review discusses three areas that hold promise for raising benefits to workers while reducing workers' compensation costs to employers: improving safety, containing medical costs, and reducing litigation. In theory, workers' compensation increases the costs to employers of injuries and so provides incentives to improve safety. Yet, taken as a whole, research does not provide convincing evidence that workers' compensation reduces injury rates. Moreover, unlike safety and health regulation, workers' compensation focuses the attention of employers on individual workers. High costs may lead employers to discourage claims and litigate when claims are filed. Controlling medical costs can reduce workers' compensation costs. Most studies, however, have focused on costs and have not addressed the effectiveness of medical care or patient satisfaction. Research also has shown that workers' compensation systems can reduce the need for litigation. Without litigation, benefits can be delivered more quickly and at lower costs.
Urban Poverty
Authors: Wilson William Julius , Aponte Robert 
Published: July 2003

This chapter is a state of the art review of the research and theoretical writing on urban poverty. We reveal that there has been an ebb and flow in the study of urban poverty in America. The social reform movement of early twentieth century, responding to the dislocation that accompanied rapid industrialization, prompted a number of descriptive and muckraking studies of poverty in urban areas. At roughly the same time, sociologists at the University of Chicago conducted a prodigious volume of research on urban life, including a number of ethnographic studies on poverty that were far more analytical and systematic than those of the social reformers. However, by the late 1930s scholarly research on urban poverty was on the wane, only to be revived again in the 1960s following the rediscovery of poverty and the emergence of the Great Society program. We point out that the subject of urban poverty and the structure of the family has drawn considerable attention from researchers since the mid-1960s and has helped to raise the level of national interest in the problems of the inner city and the crystallization of a sizable ghetto underclass. It is emphasized, however, that with the emergence of longitudinal data sets many assumptions about the intergenerational transmission of poverty and persistent poverty in the inner city have been challenged. We furthermore maintain that research on urban poverty and migration has raised questions and generated new insights on the contribution of the urban migrant to the current problems of innercity poverty and social dislocations; and that several recent studies, possibly representing a trend in urban poverty research, have provided significant insights on the relationship between poverty and welfare dependency. However, we point out that since the results of the public policy research are so mixed, it would be risky to draw policy recommendations from them. On the other hand, the most recent studies of the effects of the Reagan budget cuts (the Omnibus Budget Reconciliation Act of 1981) on the working poor are clear and consistent: they reveal the nature of the federal government's dramatic retreat from the Great Society programs of the 1960s.
Childhood in Sociodemographic Perspective
Authors: Hernandez Donald J. 
Published: July 2003

This article reviews the emerging sociodemographic literature on the relationships linking children and their families, by focusing on four topics: (a) the short-term implications for children of parents' family behavior, (b) the short-term implications for parents of the number and ages, or spacing, of their children, (c) the long-term implications of childhood family experiences for subsequent adult behavior, and (d) the probable family circumstances of children in the future. Studies of how parents influence children found (a) that increases in illegitimate fertility and divorce led to a large rise in the proportion of children living in one-parent families, usually with the mother, and in stepfamilies, (b) that children in families maintained by mothers, but not in stepfamilies, experience numerous social, economic, and psychological disadvantages, (c) that, contrary to the popular stereotype, white children in families maintained by mothers are more likely than black children in such families either to be living with or to receive financial assistance from extended family members, and (d) declining fertility and birth cohort size may have led to reductions in the welfare of children compared to the welfare of the elderly during the last 20 years. Studies of how children influence parents found that the presence of at least one child probably reduced marital satisfaction; the presence of a small number of children, especially preschool children, deters parental divorce; children reduce remarriage probabilities for young mothers, but increase them for older mothers; and at least the first and second child probably reduce family income and savings. Studies of how childhood experiences affect individuals in adulthood find that divorce of one's parents reduces one's own marriage probabilities and increases one's own divorce probabilities; childhood stepfamilies have little effect on adult circumstances; contrary to the popular stereotype, children without siblings are not disadvantaged compared to other children; an increasing number of siblings leads to reduced educational attainments, and increasing educational mobility among men with small or medium numbers of siblings accounts for the increase observed for all men during this century. Recent projections suggest that 50-75% of the 1980 birth cohort may live in a one-parent family during childhood, with a range of 40-70% for whites and a range of 85-95% for blacks.
On Discovering and Teaching Sociology: A Memoir
Authors: Riesman David 
Published: July 2003

The focus of the article is on the author's experience as learner and teacher. The task of preparing law students for their professional life is compared to that of teaching undergraduates who, in the uniquely strenuous College of the University of Chicago, are interested in books and ideas and are not immediately job-driven. Whereas in the law school setting the author, like other law professors, worked alone, in the College he worked with a staff of colleagues who shared in the choice of readings and in lectures to the entire student body—altogether, in the author's view, a more demanding task for the teacher. Graduate education in sociology is again different: the student is an apprentice professional, but there is no clear road toward professional practice; the faculty member as mentor on the dissertation helps pilot the apprentice through the cross-currents of conflict in the field and in the particular department. Teaching undergraduates in Harvard College, the author reports, involved tasks different from those faced in the College of the University of Chicago. Rather than working, as at Chicago, with a staff of presumptive equals, at Harvard the author recruited advanced graduate students and junior (and on occasion, senior) faculty whom he treated as colleagues, but whom Harvard undergraduates tended to deprecate as mere “section men,” i.e. teaching assistants. The author details efforts to overcome what was 30 years ago the fabled yet quite real pose of “Harvard indifference” a lack of engagement with subject matter and with noncelebrity faculty. The Harvard colleague group worked to get students to do small pieces of fieldwork, not merely as exercises, but out of interest in a topic and an idea. When with the rise of a radical student-faculty “movement” many undergraduates became less “cool,” the problems of teaching subtly changed. Always, the author notes, teaching is contextual and often needs to work against the prevailing tide.
Globalization and the Governance of Biotechnology
Authors: Newell Peter 
Published: July 2003

This article focuses on the disjuncture between the regulatory problems generated by the rapid development of, and subsequent trade in crop “genetically modified organisms” (GMOs), and the ability of existing international governance mechanisms to manage the associated human and ecological risks. The article assesses how the globalization of economic activity is reconfiguring patterns of production, investment, regulation and political authority as they relate to the governance of biotechnology. It is argued that our collective ability to provide social and environmental protection from GMO-related risks must be understood in relation to the global economic processes which create the technology and influence the policy processes set up to manage it. This requires an enhanced understanding of the reciprocal relationships between intra- and inter-firm decision-making and global decision-making.
Liquid‐crystalline copolyester/clay nanocomposites
Authors: Zhang Guangli , Jiang Cuihong , Su Chenyu , Zhang Hongzhi 
Published: July 2003

AbstractA series of novel polymer–clay nanocomposites, that is, liquid‐crystalline copolyester/montmorillonite (MMT) nanocomposites, were synthesized by the intercalation polycondensation of terephthalic acid, p‐acetoxy benzoic acid, and 1,2‐diacetoxy benzene in the presence of different organically modified montmorillonites (OMt's). The OMt's were prepared by the ion exchange of MMT with octadecylamine hydrochloride, p‐aminobenzoic acid hydrochloride, or lysine hydrochloride. X‐ray diffraction and transmission electron microscopy studies indicated that the inorganic cations in the MMT interlayers were already exchanged by organic onium ions and that the OMt intercalated with p‐aminobenzoic acid or lysine was good for obtaining more delaminated clay nanocomposites. The glass‐transition temperature and modulus of the nanocomposites increased compared with those of the pure polymer, whereas the isotropic temperature decreased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3155–3159, 2003
Adsorption mechanism of surfactants on nonwoven fabrics
Authors: Cai Bing , Zheng Qing‐Kang , Li Rui‐Xia , Wu Da‐Cheng 
Published: July 2003

AbstractFor improved surface properties, nonwoven fabrics of polypropylene and poly(ethylene terephthalate) were treated with several kinds of surfactants, including anionic, cationic, and nonionic types. The adsorption isotherms of the anionic, cationic, and nonionic surfactants on the nonwoven fabrics were different. The adsorption isotherm of the cationic surfactant (dodecyl dimethylbenzyl/ammonium chloride) exhibited a maximum. The adsorption isotherm of the anionic surfactant (sodium dodecylbenzene sulfonate) was in the shape of the fifth Brunauer adsorption isotherm, and that of the nonionic surfactant (alkylphenol/ethylene oxide condensate) was similar to the fourth Brunauer adsorption isotherm. The time of the adsorption equilibrium was constant for the same types of adsorbate and adsorbent, and it was not related to the initial concentration. The specific surface resistance of the nonwoven fabrics decreased substantially after the adsorption of ionic surfactants. The nonwoven fabrics with the surfactants were characterized with scanning electron microscopy and X‐ray photoelectron spectroscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3210–3215, 2003
Carboxymethylation of Cassia tora gum
Authors: Sharma Brij Raj , Kumar Vineet , Soni P. L. , Sharma Pradeep 
Published: July 2003

AbstractThe preparation of carboxymethyl (CM)–Cassia tora gum (CTG) with monochloroacetic acid and sodium hydroxide was investigated under different reaction conditions. The carboxymethylation reaction was studied with respect to the degree of substitution of CM–CTG. The variables studied were the concentration of reactants, methanol–water ratio (solvent), reaction time, and reaction temperature. Carboxymethylation of CTG increased its solubility in cold water and the stability of its paste to microorganisms. Regardless of the degree of substitution of these products, their aqueous solutions were characterized by non‐Newtonian pseudoplastic behavior. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3216–3219, 2003
A kinetics model for interphase formation in thermosetting matrix composites
Authors: Yang F. , Pitchumani R. 
Published: July 2003

AbstractDuring the cure of thermosetting polymer composites, the presence of reinforcing fibers significantly alters the resin composition in the vicinity of the fiber surface via several microscale processes, forming an interphase region with different chemical and physical properties from the bulk resin. The interphase composition is an important parameter that determines the micromechanical properties of the composite. Interphase development during processing is a result of the mass‐transport processes of adsorption, desorption, and diffusion near the fiber surface, which are accompanied by simultaneous cure reactions between the resin components. Due to complexities of the molecular‐level mechanisms near the fiber surface, few studies have been carried out on the prediction of the interphase evolution as function of the process parameters. To address this void, a kinetics model was developed in this study to describe the coupled mass‐transfer and reaction processes leading to interphase formation. The parameters of the model were determined for an aluminum fiber/diglycidyl ether of bisphenol‐A/bis(p‐aminocyclohexyl)methane resin system from available experimental data in the literature. Parametric studies are presented to show the effects of different governing mechanisms on the formation of the interphase region for a general fiber–resin system. The interphase structure obtained from the model may be used as input data for the prediction of the overall composite properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3220–3236, 2003
Deformation and fracture of Mg(OH)2‐filled polyolefin composites under tensile stress
Authors: Zhu Song , Zhang Yong , Zhang Yinxi 
Published: July 2003

AbstractThe tensile behavior of high‐density polyethylene (HDPE), polypropylene (PP), and linear low‐density polyethylene composites containing a titanate coupling agent and silicone‐oil‐treated magnesium hydroxide [Mg(OH)2] was studied. The increase in the extent of the ultimate elongation of the composites was affected by the yield stress and the strain‐hardening tendency of the polymer matrix in the composites. Ethylene–propylene–diene rubber and octane–ethylene copolymer were introduced to adjust the yield stress of PP and HDPE. Although the ultimate elongation of PP/elastomer and HDPE/elastomer blends was higher than that of virgin PP or HDPE, the ultimate elongation of the filled composites dropped at a high content of Mg(OH)2. Scanning electron microscopy showed that the difference in the uniformity of the interface exfoliation decreased with the yield stress of the matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3248–3255, 2003