Showing papers by "Rutgers University published in 1998"

Natural history of cervicovaginal papillomavirus infection in young women

Abstract: Background Genital human papillomavirus (HPV) infection is highly prevalent in sexually active young women. However, precise risk factors for HPV infection and its incidence and duration are not well known. Methods We followed 608 college women at six-month intervals for three years. At each visit, we collected information about lifestyle and sexual behavior and obtained cervicovaginal-lavage samples for the detection of HPV DNA by polymerase chain reaction and Southern blot hybridization. Pap smears were obtained annually. Results The cumulative 36-month incidence of HPV infection was 43 percent (95 percent confidence interval, 36 to 49 percent). An increased risk of HPV infection was significantly associated with younger age, Hispanic ethnicity, black race, an increased number of vaginal-sex partners, high frequencies of vaginal sex and alcohol consumption, anal sex, and certain characteristics of partners (regular partners having an increased number of lifetime partners and not being in school). The me...

Noncommutative Geometry and Matrix Theory: Compactification on Tori

Abstract: We study toroidal compactification of Matrix theory, using ideas and results of non-commutative geometry. We generalize this to compactification on the noncommutative torus, explain the classification of these backgrounds, and argue that they correspond in supergravity to tori with constant background three-form tensor field. The paper includes an introduction for mathematicians to the IKKT formulation of Matrix theory and its relation to the BFSS Matrix theory.

Omental and subcutaneous adipose tissues of obese subjects release interleukin-6: depot difference and regulation by glucocorticoid.

Abstract: The purpose of this study was to determine whether human adipocytes from different depots of obese subjects produce interleukin-6 (IL-6) and whether IL-6 release is regulated by glucocorticoids. Fragments of omental and abdominal sc adipose tissue released immunodetectable IL-6 into the medium during acute incubations. Omental adipose tissue released 2-3 times more IL-6 than did sc adipose tissue. Isolated adipocytes prepared from these tissues also released IL-6 (omental > sc), but this accounted for only 10% of the total tissue release. Culture of adipose tissue fragments for 7 days with the glucocorticoid dexamethasone markedly suppressed IL-6 production. These data show for the first time that substantial quantities of IL-6 (up to 75 ng/mL) accumulate in the medium during incubations of both adipocytes and adipose tissue. Although little is known about the effects of IL-6 on adipose tissue, one action is a down-regulation of adipose tissue lipoprotein lipase. The regulated production of this multifunctional cytokine may modulate regional adipose tissue metabolism and may contribute to the recently reported correlation between serum IL-6 and the level of obesity.

Defense gene induction in tobacco by nitric oxide, cyclic GMP, and cyclic ADP-ribose

Abstract: Reactive oxygen species are believed to perform multiple roles during plant defense responses to microbial attack, acting in the initial defense and possibly as cellular signaling molecules. In animals, nitric oxide (NO) is an important redox-active signaling molecule. Here we show that infection of resistant, but not susceptible, tobacco with tobacco mosaic virus resulted in enhanced NO synthase (NOS) activity. Furthermore, administration of NO donors or recombinant mammalian NOS to tobacco plants or tobacco suspension cells triggered expression of the defense-related genes encoding pathogenesis-related 1 protein and phenylalanine ammonia lyase (PAL). These genes were also induced by cyclic GMP (cGMP) and cyclic ADP-ribose, two molecules that can serve as second messengers for NO signaling in mammals. Consistent with cGMP acting as a second messenger in tobacco, NO treatment induced dramatic and transient increases in endogenous cGMP levels. Furthermore, NO-induced activation of PAL was blocked by 6-anilino-5,8-quinolinedione and 1H-(1,2,4)-oxadiazole[4,3-a]quinoxalin-1-one, two inhibitors of guanylate cyclase. Although 6-anilino-5,8-quinolinedione fully blocked PAL activation, inhibition by 1H-(1,2,4)-oxadiazole[4,3-a]quinoxalin-1-one was not entirely complete, suggesting the existence of cGMP-independent, as well as cGMP-dependent, NO signaling. We conclude that several critical players of animal NO signaling are also operative in plants.

Self-promotion as a risk factor for women: the costs and benefits of counterstereotypical impression management.

Abstract: Three experiments tested and extended recent theory regarding motivational influences on impression formation (S. T. Fiske & S. L. Neuberg, 1990; J. L. Hilton & J. M. Darley, 1991) in the context of an impression management dilemma that women face: Self-promotion may be instrumental for managing a competent impression, yet women who self-promote may suffer social reprisals for violating gender prescriptions to be modest. Experiment 1 investigated the influence of perceivers' goals on processes that inhibit stereotypical thinking, and reactions to counterstereotypical behavior. Experiments 2-3 extended these findings by including male targets. For female targets, self-promotion led to higher competence ratings but incurred social attraction and hireability costs unless perceivers were outcome-dependent males. For male targets, self-effacement decreased competence and hireability ratings, though its effects on social attraction were inconsistent.

Elements of large-sample theory

Abstract: This introductory book on the most useful parts of large-sample theory is designed to be accessible to scientists outside statistics and certainly to master’s-level statistics students who ignore most of measure theory. According to the author, “the subject of this book, first-order large- sample theory, constitutes a coherent body of concepts and results that are central to both theoretical and applied statistics.” All of the other existing books published on the subject over the last 20 years, from Ibragimov and Has’minskii in 1979 to the most recent by Van der Waart in 1998 have a common prerequisite in mathematical sophistication (measure theory in particular) that do not make the concepts available to a wide audience.

Sodium Reduction and Weight Loss in the Treatment of Hypertension in Older Persons: A Randomized Controlled Trial of Nonpharmacologic Interventions in the Elderly (TONE)

Abstract: Context.—Nonpharmacologic interventions are frequently recommended for treatment of hypertension in the elderly, but there is a paucity of evidence from randomized controlled trials in support of this recommendation.Objective.—To determine whether weight loss or reduced sodium intake is effective in the treatment of older persons with hypertension.Design.—Randomized controlled trial.Participants.—A total of 875 men and women aged 60 to 80 years with systolic blood pressure lower than 145 mm Hg and diastolic blood pressure lower than 85 mm Hg while receiving treatment with a single antihypertensive medication.Setting.—Four academic health centers.Intervention.—The 585 obese participants were randomized to reduced sodium intake, weight loss, both, or usual care, and the 390 nonobese participants were randomized to reduced sodium intake or usual care. Withdrawal of antihypertensive medication was attempted after 3 months of intervention.Main Outcome Measure.—Diagnosis of high blood pressure at 1 or more follow-up visits, or treatment with antihypertensive medication, or a cardiovascular event during follow-up (range, 15-36 months; median, 29 months).Results.—The combined outcome measure was less frequent among those assigned vs not assigned to reduced sodium intake (relative hazard ratio, 0.69; 95% confidence interval [CI], 0.59-0.81; P<.001) and, in obese participants, among those assigned vs not assigned to weight loss (relative hazard ratio, 0.70; 95% CI, 0.57-0.87; P<.001). Relative to usual care, hazard ratios among the obese participants were 0.60 (95% CI, 0.45-0.80; P<.001) for reduced sodium intake alone, 0.64 (95% CI, 0.49-0.85; P=.002) for weight loss alone, and 0.47 (95% CI, 0.35-0.64; P<.001) for reduced sodium intake and weight loss combined. The frequency of cardiovascular events during follow-up was similar in each of the 6 treatment groups.Conclusion.—Reduced sodium intake and weight loss constitute a feasible, effective, and safe nonpharmacologic therapy of hypertension in older persons.

Recommendation as classification: using social and content-based information in recommendation

Abstract: Recommendation systems make suggestions about artifacts to a user. For instance, they may predict whether a user would be interested in seeing a particular movie. Social recomendation methods collect ratings of artifacts from many individuals, and use nearest-neighbor techniques to make recommendations to a user concerning new artifacts. However, these methods do not use the significant amount of other information that is often available about the nature of each artifact - such as cast lists o r movie reviews, for example. This paper presents an inductive learning approach to recommendation that is able to use both ratings information and other forms of information about each artifact in predicting user preferences. We show that our method outperforms an existing social-filtering method in the domain of movie recommendations on a dataset of more than 45,000 movie ratings collected from a community of over 250 users.

Concepts: Where Cognitive Science Went Wrong

Abstract: 1. Philosophical Introduction: The Background Theory. 2. Unphilosophical Introduction: What Concepts Have To Be. 3. The Demise of Definitions, Part I: The Linguist's Tale. 4. The Demise of Definitions, Part II: The Philosopher's Tale. 5. Prototypes and Compositionality. (Appendix 5A: Meaning Postulates. Appendix 5B: The 'Theory Theory' of Concepts.) 6. Innateness and Ontology, Part I: The Standard Argument. (Appendix 6A: Similarity.) 7. Innateness and Ontology, Part II: Intentional Laws and Natural Kinds. (Appendix 7A: Round Squares.) Bibliography Index

DNA sequence-dependent deformability deduced from protein–DNA crystal complexes

Abstract: The deformability of double helical DNA is critical for its packaging in the cell, recognition by other molecules, and transient opening during biochemically important processes. Here, a complete set of sequence-dependent empirical energy functions suitable for describing such behavior is extracted from the fluctuations and correlations of structural parameters in DNA–protein crystal complexes. These elastic functions provide useful stereochemical measures of the local base step movements operative in sequence-specific recognition and protein-induced deformations. In particular, the pyrimidine-purine dimers stand out as the most variable steps in the DNA–protein complexes, apparently acting as flexible “hinges” fitting the duplex to the protein surface. In addition to the angular parameters widely used to describe DNA deformations (i.e., the bend and twist angles), the translational parameters describing the displacements of base pairs along and across the helical axis are analyzed. The observed correlations of base pair bending and shearing motions are important for nonplanar folding of DNA in nucleosomes and other nucleoprotein complexes. The knowledge-based energies also offer realistic three-dimensional models for the study of long DNA polymers at the global level, incorporating structural features beyond the scope of conventional elastic rod treatments and adding a new dimension to literal analyses of genomic sequences.

Functional role of estrogen metabolism in target cells: review and perspectives.

Abstract: Cytochrome P450 enzymes that metabolize estrogens are expressed in the mammary gland, uterus, brain and other target tissues for estrogen action, and this results in the formation of hydroxylated estrogens in these tissues. Estradiol metabolites formed in target tissues at or near estrogen receptors may either be inactive or have important biological effects, and changes in the activities of estrogen-metabolizing enzymes in target tissues may profoundly influence estrogen action. Although some active estrogen metabolites exert hormonal effects in target tissues by interaction with the classical estrogen receptor, other metabolites appear to elicit unique biological responses that are not associated with activation of this receptor. Therefore, some of the many actions of estradiol may not be caused by estradiol per se, but may result from the formation of active estrogen metabolite(s) which function as local mediators or may activate their own unique receptors or effectors. This is an important area in need of more research. The present paper represents a review of the literature and perspectives by the authors on the functional role of estrogen metabolism in target tissues.

Social Origins of Civil Society: Explaining the Nonprofit Sector Cross-Nationally

Abstract: Recent research has usefully documented the contribution that nonprofit organizations make to “social capital” and to the economic and political development it seems to foster. Because of a gross lack of basic comparative data, however, the question of what it is that allows such organizations to develop remains far from settled. This article seeks to remedy this by testing five existing theories of the nonprofit sector against data assembled on eight countries as part of the Johns Hopkins Comparative Nonprofit Sector Project. The five theories are: (a) government failure/market failure theory; (b) supply-side theory; (c) trust theories; (d) welfare state theory; and (e) interdependence theory. The article finds none of these theories adequate to explain the variations among countries in either the size, the composition, or the financing of the nonprofit sector. On this basis it suggests a new theoretical approach to explaining patterns of nonprofit development among countries—the “social origins” approach—which focuses on broader social, political, and economic relationships. Using this theory, the article identifies four “routes” of third-sector development (the liberal, the social democratic, the corporatist, and the statist), each associated with a particular constellation of class relationships and pattern of state-society relations. The article then tests this theory against the eight-country data and finds that it helps make sense of anomalies left unexplained by the prevailing theories.

Shock graphs and shape matching

Abstract: We have been developing a theory for the generic representation of 2-D shape, where structural descriptions are derived from the shocks (singularities) of a curve evolution process, acting on bounding contours. We now apply the theory to the problem of shape matching. The shocks are organized into a directed, acyclic shock graph, and complexity is managed by attending to the most significant (central) shape components first. The space of all such graphs is highly structured and can be characterized by the rules of a shock graph grammar. The grammar permits a reduction of a shockgraph to a unique rooted shock tree. We introduce a novel tree matching algorithm which finds the best set of corresponding nodes between two shock trees in polynomial time. Using a diverse database of shapes, we demonstrate our system's performance under articulation, occlusion, and changes in viewpoint.

D-branes and the noncommutative torus

Abstract: We show that in certain superstring compactifications, gauge theories on noncommutative tori will naturally appear as D-brane world-volume theories. This gives strong evidence that they are well-defined quantum theories. It also gives a physical derivation of the identification proposed by Connes, Douglas and Schwarz of Matrix theory compactification on the noncommutative torus with M theory compactification with constant background three-form tensor field.

GABAergic Cells Are the Major Postsynaptic Targets of Mossy Fibers in the Rat Hippocampus

Abstract: Dentate granule cells communicate with their postsynaptic targets by three distinct terminal types. These include the large mossy terminals, filopodial extensions of the mossy terminals, and smaller en passant synaptic varicosities. We examined the postsynaptic targets of mossy fibers by combining in vivo intracellular labeling of granule cells, immunocytochemistry, and electron microscopy. Single granule cells formed large, complex “mossy” synapses on 11–15 CA3 pyramidal cells and 7–12 hilar mossy cells. In contrast, GABAergic interneurons, identified with immunostaining for substance P-receptor, parvalbumin, and mGluR1a-receptor, were selectively innervated by very thin (filopodial) extensions of the mossy terminals and by small en passant boutons in both the hilar and CA3 regions. These terminals formed single, often perforated, asymmetric synapses on the cell bodies, dendrites, and spines of GABAergic interneurons. The number of filopodial extensions and small terminals was 10 times larger than the number of mossy terminals. These findings show that in contrast to cortical pyramidal neurons, (1) granule cells developed distinct types of terminals to affect interneurons and pyramidal cells and (2) they innervated more inhibitory than excitatory cells. These findings may explain the physiological observations that increased activity of granule cells suppresses the overall excitability of the CA3 recurrent system and may form the structural basis of the target-dependent regulation of glutamate release in the mossy fiber system.

Stage theories of health behavior: conceptual and methodological issues.

Abstract: Despite growing interest in stage theories of health behavior, there is considerable confusion in the literature concerning the essential characteristics of stage theories and the manner in which such theories should be tested. In this article, the 4 key characteristics of a stage theory-a category system, an ordering of categories, similar barriers to change within categories, and different barriers to change between categories--are discussed in detail. Examples of stage models of health behavior also are described. Four major types of research designs that might be used for testing stage theories are examined, including examples from the empirical literature. The most commonly used design, which involves cross-sectional comparisons of people believed to be in different stages, is shown to have only limited value for testing whether behavior change follows a stage process.

How can Cooperation be Fostered? The Cultural Effects of Individualism-Collectivism

Abstract: Studies of cooperation are abundant in the social sciences, but organizational researchers are calling for integrating the numerous conceptions of cooperation and meeting the new challenges of cultural differences. In this article we develop a culturally contingent model of cooperation. We differentiate various mechanisms from cooperative behaviors and theorize about how culture affects behavioral cooperation through mechanism selection or modification. Delineating cultural effects, we derive patterned differences in the instrumental and expressive motives of individualists and collectivists and propose six culturally contrasting cooperation mechanisms. Finally, we discuss directions for future research and consider implications for practice.

Inhibition of growth and induction of apoptosis in human cancer cell lines by tea polyphenols.

Abstract: In order to study the biological activities of tea preparations and purified tea polyphenols, their growth inhibitory effects were investigated using four human cancer cell lines. Growth inhibition was measured by [3H]thymidine incorporation after 48 h of treatment. The green tea catechins (-)-epigallocatechin-3-gallate (EGCG) and (-)-epigallocatechin (EGC) displayed strong growth inhibitory effects against lung tumor cell lines H661 and H1299, with estimated IC50 values of 22 microM, but were less effective against lung cancer cell line H441 and colon cancer cell line HT-29 with IC50 values 2- to 3-fold higher. (-)-Epicatechin-3-gallate, had lower activities, and (-)-epicatechin was even less effective. Preparations of green tea polyphenols and theaflavins had higher activities than extracts of green tea and decaffeinated green tea. The results suggest that the growth inhibitory activity of tea extracts is caused by the activities of different tea polyphenols. Exposure of H661 cells to 30 microM EGCG, EGC or theaflavins for 24 h led to the induction of apoptosis as determined by an annexin V apoptosis assay, showing apoptosis indices of 23, 26 and 8%, respectively; with 100 microM of these compounds, the apoptosis indices were 82, 76 and 78%, respectively. Incubation of H661 cells with EGCG also induced a dose-dependent formation of H2O2. Addition of H2O2 to H661 cells caused apoptosis in a manner similar to that caused by EGCG. The EGCG-induced apoptosis in H661 cells was completely inhibited by exogenously added catalase (50 units/ml). These results suggest that tea polyphenol-induced production of H2O2 may mediate apoptosis and that this may contribute to the growth inhibitory activities of tea polyphenols in vitro.

Real life information retrieval: a study of user queries on the Web

Abstract: We analyzed transaction logs of a set of 51,473 queries posed by 18,113 users of Excite, a major Internet search service. We provide data on: (i) queries --- the number of search terms, and the use of logic and modifiers, (ii) sessions --- changes in queries during a session, number of pages viewed, and use of relevance feedback, and (iii) terms --- their rank/frequency distribution and the most highly used search terms. Common mistakes are also observed. Implications are discussed.

Self-regulation, health, and behavior: A perceptual-cognitive approach

Abstract: Self-regulation systems are designed to adapt to threats via coping procedures that make efficient use of resources based upon valid representations of the environment. We discuss two components of the common-sense model of health threats: illness representations (e.g., content and organization) and coping procedures (e.g., classes of procedure and their attributes - outcome expectancies, time-lines, dose-efficacy beliefs, etc.). Characteristics of each of these domains, and the connection between the two, are critical to understanding human adaptation to problems of physical health. Rather than posing a barrier to factors outside the person that control behavior, an emphasis on subjective construal involves a view of the person as an active problem-solver embedded in a bidirectional system of sensitivity and responsiveness vis a vis the social, physical, and institutional environments in which health threats occur and through which intervention efforts may be directed.