Showing papers by "Pennsylvania State University published in 2000"
Donald G. York1, Jennifer Adelman2, John E. Anderson2, Scott F. Anderson3 +148 more•Institutions (29)
TL;DR: The Sloan Digital Sky Survey (SDSS) as discussed by the authors provides the data to support detailed investigations of the distribution of luminous and non-luminous matter in the universe: a photometrically and astrometrically calibrated digital imaging survey of π sr above about Galactic latitude 30° in five broad optical bands to a depth of g' ~ 23 mag.
Abstract: The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of the distribution of luminous and nonluminous matter in the universe: a photometrically and astrometrically calibrated digital imaging survey of π sr above about Galactic latitude 30° in five broad optical bands to a depth of g' ~ 23 mag, and a spectroscopic survey of the approximately 106 brightest galaxies and 105 brightest quasars found in the photometric object catalog produced by the imaging survey. This paper summarizes the observational parameters and data products of the SDSS and serves as an introduction to extensive technical on-line documentation.
9,835 citations
TL;DR: A new greedy alignment algorithm is introduced with particularly good performance and it is shown that it computes the same alignment as does a certain dynamic programming algorithm, while executing over 10 times faster on appropriate data.
Abstract: For aligning DNA sequences that differ only by sequencing errors, or by equivalent errors from other sources, a greedy algorithm can be much faster than traditional dynamic programming approaches and yet produce an alignment that is guaranteed to be theoretically optimal. We introduce a new greedy alignment algorithm with particularly good performance and show that it computes the same alignment as does a certain dynamic programming algorithm, while executing over 10 times faster on appropriate data. An implementation of this algorithm is currently used in a program that assembles the UniGene database at the National Center for Biotechnology Information.
4,628 citations
TL;DR: It is proposed that, behaviorally, females' responses to stress are more marked by a pattern of "tend-and-befriend," and neuroendocrine evidence from animal and human studies suggests that oxytocin, in conjunction with female reproductive hormones and endogenous opioid peptide mechanisms, may be at its core.
Abstract: The human stress response has been characterized, both physiologically and behaviorally, as "fight-or-flight." Although fight-or-flight may characterize the primary physiological responses to stress for both males and females, we propose that, behaviorally, females' responses are more marked by a pattern of "tend-and-befriend." Tending involves nurturant activities designed to protect the self and offspring that promote safety and reduce distress; befriending is the creation and maintenance of social networks that may aid in this process. The biobehavioral mechanism that underlies the tend-and-befriend pattern appears to draw on the attachment-caregiving system, and neuroendocrine evidence from animal and human studies suggests that oxytocin, in conjunction with female reproductive hormones and endogenous opioid peptide mechanisms, may be at its core. This previously unexplored stress regulatory system has manifold implications for the study of stress.
2,588 citations
TL;DR: This article summarized and organized the empirical literature on the consequences of divorce for adults and children, and drew on research in the 1990s to answer five questions: How do individuals from married and divorced families differ in well-being? Do these differences reflect a temporary crisis to which most people gradually adapt or stable life strains that persist more or less indefinitely? What factors mediate the effects of divorce on individual adjustment? And finally, what are the moderators (protective factors) that account for individual variability in adjustment to divorce?
Abstract: I use a divorce-stress-adjustment perspective to summarize and organize the empirical literature on the consequences of divorce for adults and children. My review draws on research in the 1990s to answer five questions: How do individuals from married and divorced families differ in well-being? Are these differences due to divorce or to selection? Do these differences reflect a temporary crisis to which most people gradually adapt or stable life strains that persist more or less indefinitely? What factors mediate the effects of divorce on individual adjustment? And finally, what are the moderators (protective factors) that account for individual variability in adjustment to divorce? In general, the accumulated research suggests that marital dissolution has the potential to create considerable turmoil in people's lives. But people vary greatly in their reactions. Divorce benefits some individuals, leads others to experience temporary decrements in well-being, and forces others on a downward trajectory from which they might never recover fully. Understanding the contingencies under which divorce leads to these diverse outcomes is a priority for future research.
2,560 citations
TL;DR: In this article, the authors used spectro- photometrically monitored Palomar-Green quasars in order to obtain mea- surements of their emission lines and investigate the relationship between quasar luminosity, central black hole mass, and broad emission-line regions (BLRs) size in AGNs.
Abstract: Correlated variations in the line and continuum emission from active galactic nuclei (AGNs) can be used to determine the size and geometry of the broad emission-line regions (BLRs). We have spectro- photometrically monitored a well-de—ned sample of 28 Palomar-Green quasars in order to obtain mea- surements of their BLRs and to investigate the relationships between quasar luminosity, central black hole mass, and BLR size in AGNs. Spectrophotometry was obtained every 1¨4 months for 7.5 yr, yield- ing 20¨70 observing epochs per object. Both the continuum and emission-line —uxes of all of the quasars were observed to change during the duration of the observing program. Seventeen of the 28 objects were observed with adequate sampling independent observing epochs) to search for correlated variations (Z20 between the Balmer emission lines and the continuum —ux. For each of these 17 objects, a signi—cant correlation was observed, with the Balmer-line variations lagging those of the continuum by D100 days (rest frame). Our work increases the available luminosity range for studying the size-mass-luminosity relations in AGNs by 2 orders of magnitude and doubles the number of objects suitable for such studies. Combining our results with comparable published data available for Seyfert 1 galaxies, we —nd the BLR size scales with the rest-frame 5100 luminosity as L0.70B0.03. This determination of the scaling of the Ae size of the BLR as a function of luminosity is signi—cantly diUerent from those previously published and suggests that the eUective ionization parameter in AGNs may be a decreasing function of luminosity. We are also able to constrain, subject to our assumption that gravity dominates the motions of the BLR gas, the scaling relationship between the mass of the central black holes and the luminosity in AGNs. We —nd that the central mass scales with 5100 luminosity as M P L0.5B0.1. This is inconsistent with all Ae AGNs having optical luminosity that is a constant fraction of the Eddington luminosity. Subject headings: galaxies: activequasars: emission linesquasars: general
2,119 citations
TL;DR: A recent review examines the field of leadership development through three contextual lenses: (1) understanding the difference between leader development and leadership development ( conceptual context); (2) reviewing how state-of-the-art development is being conducted in the context of ongoing organizational work ( practice context); and (3) summarizing previous research that has implications for leadership development as mentioned in this paper.
Abstract: Interest in leadership development is strong, especially among practitioners Nonetheless, there is conceptual confusion regarding distinctions between leader and leadership development, as well as disconnection between the practice of leadership development and its scientific foundation The present review examines the field of leadership development through three contextual lenses: (1) understanding the difference between leader development and leadership development ( conceptual context); (2) reviewing how state-of-the-art development is being conducted in the context of ongoing organizational work ( practice context); and (3) summarizing previous research that has implications for leadership development ( research context) The overall purpose is to bridge the practice and science of leadership development by showing the importance of building both human and social capital in organizations Specific practices that are reviewed include 360-degree feedback and executive coaching, mentoring and networking, and job assignments and action learning Practices and research are framed in terms of a general need to link leader development, which is primarily based on enhancing human capital, with leadership development that emphasizes the creation of social capital in organizations
2,049 citations
TL;DR: In this paper, the authors argue that organizational identity is a relatively fluid and unstable concept, and instead of destabilizing an organization, this instability in identity is actually adaptive in accomplishing change.
Abstract: Organizational identity usually is portrayed as that which is core, distinctive, and enduring about the character of an organization. We argue that because of the reciprocal interrelationships between identity and image, organizational identity, rather than enduring, is better viewed as a relatively fluid and unstable concept. We further argue that instead of destabilizing an organization, this instability in identity is actually adaptive in accomplishing change. The analysis leads to some provocative, but nonetheless constructive, implications for theory, research, and practice.
1,912 citations
08 Nov 2000
TL;DR: A taxonomy of fixation identification algorithms is proposed that classifies algorithms in terms of how they utilize spatial and temporal information in eye-tracking protocols in order to evaluate and compare these algorithms with respect to a number of qualitative characteristics.
Abstract: The process of fixation identification—separating and labeling fixations and saccades in eye-tracking protocols—is an essential part of eye-movement data analysis and can have a dramatic impact on higher-level analyses. However, algorithms for performing fixation identification are often described informally and rarely compared in a meaningful way. In this paper we propose a taxonomy of fixation identification algorithms that classifies algorithms in terms of how they utilize spatial and temporal information in eye-tracking protocols. Using this taxonomy, we describe five algorithms that are representative of different classes in the taxonomy and are based on commonly employed techniques. We then evaluate and compare these algorithms with respect to a number of qualitative characteristics. The results of these comparisons offer interesting implications for the use of the various algorithms in future work.
1,809 citations
TL;DR: A phylogenetic approach to recognize fungal species based on concordance of multiple gene genealogies is compared to those based on morphology and reproductive behavior.
1,691 citations
TL;DR: The results suggested that this questionnaire derives the two predicted factors (cognitively based credibility and relatively more affectively based expectancy) and that these factors are stable across different populations.
1,621 citations
TL;DR: Critical roles for IL-15 in the development of specific lymphoid lineages are revealed and the ability to rescue lymphoid defects inIL-15−/− mice by IL- 15 administration represents a powerful means by which to further elucidate the biological roles of this cytokine.
Abstract: C57BL/6 mice genetically deficient in interleukin 15 (IL-15−/− mice) were generated by gene targeting. IL-15−/− mice displayed marked reductions in numbers of thymic and peripheral natural killer (NK) T cells, memory phenotype CD8+ T cells, and distinct subpopulations of intestinal intraepithelial lymphocytes (IELs). The reduction but not absence of these populations in IL-15−/− mice likely reflects an important role for IL-15 for expansion and/or survival of these cells. IL-15−/− mice lacked NK cells, as assessed by both immunophenotyping and functional criteria, indicating an obligate role for IL-15 in the development and functional maturation of NK cells. Specific defects associated with IL-15 deficiency were reversed by in vivo administration of exogenous IL-15. Despite their immunological defects, IL-15−/− mice remained healthy when maintained under specific pathogen-free conditions. However, IL-15−/− mice are likely to have compromised host defense responses to various pathogens, as they were unable to mount a protective response to challenge with vaccinia virus. These data reveal critical roles for IL-15 in the development of specific lymphoid lineages. Moreover, the ability to rescue lymphoid defects in IL-15−/− mice by IL-15 administration represents a powerful means by which to further elucidate the biological roles of this cytokine.
TL;DR: It is shown that pVHL, through its β-domain, binds directly to hypoxia-inducible factor (HIF), thereby targeting HIF for ubiquitination in an α-domain-dependent manner, the first function to be ascribed to the pV HL β- domain.
Abstract: von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome that is characterized by the development of multiple vascular tumors and is caused by inactivation of the von Hippel-Lindau protein (pVHL). Here we show that pVHL, through its beta-domain, binds directly to hypoxia-inducible factor (HIF), thereby targeting HIF for ubiquitination in an alpha-domain-dependent manner. This is the first function to be ascribed to the pVHL beta-domain. Furthermore, we provide the first direct evidence that pVHL has a function analogous to that of an F-box protein, namely, to recruit substrates to a ubiquitination machine. These results strengthen the link between overaccumulation of HIF and development of VHL disease.
TL;DR: In this paper, the authors present guidelines for reducing the risk of cardiovascular disease by dietary and other lifestyle practices, which place increased emphasis on foods and an overall eating pattern and the need for all Americans to achieve and maintain a healthy body weight.
Abstract: This document presents guidelines for reducing the risk of cardiovascular disease by dietary and other lifestyle practices. Since the previous publication of these guidelines by the American Heart Association,1 the overall approach has been modified to emphasize their relation to specific goals that the AHA considers of greatest importance for lowering the risk of heart disease and stroke. The revised guidelines place increased emphasis on foods and an overall eating pattern and the need for all Americans to achieve and maintain a healthy body weight (Table⇓).
View this table:
Table 1.
Summary of Dietary Guidelines
The major guidelines are designed for the general population and collectively replace the “Step 1” designation used for earlier AHA population-wide dietary recommendations. More individualized approaches involving medical nutrition therapy for specific subgroups (for example, those with lipid disorders, diabetes, and preexisting cardiovascular disease) replace the previous “Step 2” diet for higher-risk individuals.
The major emphasis for weight management should be on avoidance of excess total energy intake and a regular pattern of physical activity. Fat intake of ≤30% of total energy is recommended to assist in limiting consumption of total energy as well as saturated fat. The guidelines continue to advocate a population-wide limitation of dietary saturated fat to <10% of energy and cholesterol to <300 mg/d. Specific intakes for individuals should be based on cholesterol and lipoprotein levels and the presence of existing heart disease, diabetes, and other risk factors. Because of increased evidence for the cardiovascular benefits of fish (particularly fatty fish), consumption of at least 2 fish servings per week is now recommended. Finally, recent studies support a major benefit on blood pressure of consuming vegetables, fruits, and low-fat dairy products, as well as limiting salt intake (<6 grams per day) and alcohol (no more than 2 drinks per day for men and …
TL;DR: In this paper, the mechanism of flammability reduction of polypropylene-graft-maleic anhydride and polystyrene−layered-silicate nanocomposites using montmorillonite and fluorohectorite was investigated.
Abstract: Our continuing study of the mechanism of flammability reduction of polymer−layered-silicate nanocomposites has yielded results for polypropylene-graft-maleic anhydride and polystyrene−layered-silicate nanocomposites using montmorillonite and fluorohectorite. Cone calorimetry was used to measure the heat release rate and other flammability properties of the nanocomposites, under well-controlled combustion conditions. Both the polymer−layered-silicate nanocomposites and the combustion residues were studied by transmission electron microscopy and X-ray diffraction. We have found evidence for a common mechanism of flammability reduction. We also found that the type of layered silicate, nanodispersion, and processing degradation have an influence on the flammability reduction.
TL;DR: A failure analysis was conducted, identifying trends among user mistakes, and a summary of findings and a discussion of the implications of these findings were concluded.
Abstract: We analyzed transaction logs containing 51,473 queries posed by 18,113 users of Excite, a major Internet search service. We provide data on: (i) sessions — changes in queries during a session, number of pages viewed, and use of relevance feedback; (ii) queries — the number of search terms, and the use of logic and modifiers; and (iii) terms — their rank/frequency distribution and the most highly used search terms. We then shift the focus of analysis from the query to the user to gain insight to the characteristics of the Web user. With these characteristics as a basis, we then conducted a failure analysis, identifying trends among user mistakes. We conclude with a summary of findings and a discussion of the implications of these findings. # 2000 Elsevier Science Ltd. All rights reserved.
TL;DR: The recent explosion of gene sequences and expression data has given new hints of additional biological functions for expansin, which unlocks the network of wall polysaccharides, permitting turgor-driven cell enlargement.
Abstract: Plant cell walls are the starting materials for many commercial products, from lumber, paper and textiles to thickeners, films and explosives. The cell wall is secreted by each cell in the plant body, forming a thin fibreglass-like network with remarkable strength and flexibility. During growth, plant cells secrete a protein called expansin, which unlocks the network of wall polysaccharides, permitting turgor-driven cell enlargement. Germinating grass pollen also secretes an unusual expansin that loosens maternal cell walls to aid penetration of the stigma by the pollen tube. Expansin's action has puzzling implications for plant cell-wall structure. The recent explosion of gene sequences and expression data has given new hints of additional biological functions for expansins.
TL;DR: The transition to adulthood has become a thriving area of research in life course studies as mentioned in this paper and a review is organized around two of the field's emerging themes: increasing variability in pathways to adult roles through historical time and a heightened sensitivity to transition behaviors as developmental processes.
Abstract: The transition to adulthood has become a thriving area of research in life course studies. This review is organized around two of the field's emerging themes. The first theme is the increasing variability in pathways to adult roles through historical time. The second theme is a heightened sensitivity to transition behaviors as developmental processes. Accounts of such processes typically examine the active efforts of young people to shape their biographies or the socially structured opportunities and limitations that define pathways into adulthood. By joining these concepts, I suggest new lines of inquiry that focus on the interplay between agency and social structures in the shaping of lives.
TL;DR: A review of recent research (1988 to 1998) on gender differences in environmental attitudes and behaviors found that, contrary to past inconsistencies, a clearer picture has emerged: women report stronger environmental attitudes than men as mentioned in this paper.
Abstract: A review of recent research (1988 to 1998) on gender differences in environmental attitudes and behaviors found that, contrary to past inconsistencies, a clearer picture has emerged: Women report stronger environmental attitudes and behaviors than men. Additional evidence of gender differences in environmental attitudes and behaviors was also supported across age (Study 1) and across 14 countries (Study 2). As a single variable, the effect of gender on proenvironmental behavior was consistently stronger than on environmental attitudes. Explanations for gender differences in environmentalism were examined in Study 3. It was found that compared to males, females had higher levels of socialization to be other oriented and socially responsible. Implications for theory, social action, and policy are discussed.
TL;DR: PipMaker is appropriate for comparing genomic sequences from any two related species, although the types of information that can be inferred depend on the level of conservation and the time and divergence rate since the separation of the species.
Abstract: PipMaker (http://bio.cse.psu.edu) is a World-Wide Web site for comparing two long DNA sequences to identify conserved segments and for producing informative, high-resolution displays of the resulting alignments. One display is a percent identity plot (pip), which shows both the position in one sequence and the degree of similarity for each aligning segment between the two sequences in a compact and easily understandable form. Positions along the horizontal axis can be labeled with features such as exons of genes and repetitive elements, and colors can be used to clarify and enhance the display. The web site also provides a plot of the locations of those segments in both species (similar to a dot plot). PipMaker is appropriate for comparing genomic sequences from any two related species, although the types of information that can be inferred (e.g., protein-coding regions and cis-regulatory elements) depend on the level of conservation and the time and divergence rate since the separation of the species. Gene regulatory elements are often detectable as similar, noncoding sequences in species that diverged as much as 100-300 million years ago, such as humans and mice, Caenorhabditis elegans and C. briggsae, or Escherichia coli and Salmonella spp. PipMaker supports analysis of unfinished or "working draft" sequences by permitting one of the two sequences to be in unoriented and unordered contigs.
TL;DR: There is a strong independent association among sleep apnea, visceral obesity, insulin resistance and hypercytokinemia, which may contribute to the pathological manifestations and somatic sequelae of this condition.
Abstract: Sleep apnea and associated daytime sleepiness and fatigue are common manifestations of mainly obese middle-aged men. The onset of sleep apnea peaks in middle age, and its morbid and mortal sequelae include complications from accidents and cardiovascular events. The pathophysiology of sleep apnea remains obscure. The purpose of this study was to test three separate, albeit closely related, hypotheses. 1) Does sleep apnea contribute to the previously reported changes of plasma cytokine (tumor necrosis factor-alpha and interleukin-6) and leptin levels independently of obesity? 2) Among obese patients, is it generalized or visceral obesity that predisposes to sleep apnea? 3) Is apnea a factor independent from obesity in the development of insulin resistance? Obese middle-aged men with sleep apnea were first compared with nonapneic age- and body mass index (BMI)-matched obese and age-matched lean men. All subjects were monitored in the sleep laboratory for 4 consecutive nights. We obtained simultaneous indexes of sleep, sleep stages, and sleep apnea, including apnea/hypopnea index and percent minimum oxygen saturation. The sleep apneic men had higher plasma concentrations of the adipose tissue-derived hormone, leptin, and of the inflammatory, fatigue-causing, and insulin resistance-producing cytokines tumor necrosis factor-alpha and interleukin-6 than nonapneic obese men, who had intermediate values, or lean men, who had the lowest values. Because these findings suggested that sleep apneics might have a higher degree of insulin resistance than the BMI-matched controls, we studied groups of sleep-apneic obese and age- and BMI-matched nonapneic controls in whom we obtained computed tomographic scan measures of total, sc, and visceral abdominal fat, and additional biochemical indexes of insulin resistance, including fasting plasma glucose and insulin. The sleep apnea patients had a significantly greater amount of visceral fat compared to obese controls (<0.05) and indexes of sleep disordered breathing were positively correlated with visceral fat, but not with BMI or total or sc fat. Furthermore, the biochemical data confirmed a higher degree of insulin resistance in the group of apneics than in BMI-matched nonapneic controls. We conclude that there is a strong independent association among sleep apnea, visceral obesity, insulin resistance and hypercytokinemia, which may contribute to the pathological manifestations and somatic sequelae of this condition.
TL;DR: In this article, the use of regression models based on the Poisson distribution was introduced as a tool for resolving common problems in analyzing aggregate crime rates, when the population size of an aggregate unit is small relative to the offense rate, crime rates must be computed from a small number of offenses.
Abstract: This article introduces the use of regression models based on the Poisson distribution as a tool for resolving common problems in analyzing aggregate crime rates. When the population size of an aggregate unit is small relative to the offense rate, crime rates must be computed from a small number of offenses. Such data are ill-suited to least-squares analysis. Poisson-based regression models of counts of offenses are preferable because they are built on assumptions about error distributions that are consistent with the nature of event counts. A simple elaboration transforms the Poisson model of offense counts to a model of per capita offense rates. To demonstrate the use and advantages of this method, this article presents analyses of juvenile arrest rates for robbery in 264 nonmetropolitan counties in four states. The negative binomial variant of Poisson regression effectively resolved difficulties that arise in ordinary least-squares analyses.
TL;DR: The overall approach has been modified to emphasize their relation to specific goals that the AHA considers of greatest importance for lowering the risk of heart disease and stroke and increased emphasis on foods and an overall eating pattern.
Abstract: This document presents guidelines for reducing the risk of cardiovascular disease by dietary and other lifestyle practices. Since the previous publication of these guidelines by the American Heart Association,1 the overall approach has been modified to emphasize their relation to specific goals that the AHA considers of greatest importance for lowering the risk of heart disease and stroke. The revised guidelines place increased emphasis on foods and an overall eating pattern and the need for all Americans to achieve and maintain a healthy body weight (Table⇓).
View this table:
Table 1.
Summary of Dietary Guidelines
The major guidelines are designed for the general population and collectively replace the “Step 1” designation used for earlier AHA population-wide dietary recommendations. More individualized approaches involving medical nutrition therapy for specific subgroups (for example, those with lipid disorders, diabetes, and preexisting cardiovascular disease) replace the previous “Step 2” diet for higher-risk individuals.
The major emphasis for weight management should be on avoidance of excess total energy intake and a regular pattern of physical activity. Fat intake of ≤30% of total energy is recommended to assist in limiting consumption of total energy as well as saturated fat. The guidelines continue to advocate a population-wide limitation of dietary saturated fat to <10% of energy and cholesterol to <300 mg/d. Specific intakes for individuals should be based on cholesterol and lipoprotein levels and the presence of existing heart disease, diabetes, and other risk factors. Because of increased evidence for the cardiovascular benefits of fish (particularly fatty fish), consumption of at least 2 fish servings per week is now recommended. Finally, recent studies support a major benefit on blood pressure of consuming vegetables, fruits, and low-fat dairy products, as well as limiting salt intake (<6 grams per day) and alcohol (no more than 2 drinks per day for men and …
TL;DR: The development of a measure of coping and involuntary stress responses in adolescence is described and correlations with both adolescents' and parents' reports of internalizing and externalizing symptoms were consistent with hypotheses.
Abstract: The development of a measure of coping and involuntary stress responses in adolescence is described. The Responses to Stress Questionnaire (RSQ) reflects a conceptual model that includes volitional coping efforts and involuntary responses to specific stressful events or specified domains of stress. The psychometric characteristics of the RSQ were examined across 4 domains of stress in 3 samples of adolescents and parent reports obtained in 2 samples. The factor structure of the RSQ was tested and replicated with an adequate degree of fit using confirmatory factor analysis across 3 stressors in 2 samples. Internal consistency and retest reliability for the 5 factors were adequate to excellent. Concurrent validity was established through correlations with another measure of coping, heart rate reactivity, and correlations of self- and parent-reports. Significant correlations with both adolescents' and parents' reports of internalizing and externalizing symptoms were consistent with hypotheses.
TL;DR: A review of the literature on the relationship between the father-child relationship and children's well-being and development can be found in this article, with an eye toward prominent theoretical, methodological, and substantive issues.
Abstract: Throughout the 1990s, scholars interested in fatherhood have generated a voluminous, rich, and diverse body of work. We selectively review this literature with an eye toward prominent theoretical, methodological, and substantive issues. This burgeoning literature, complemented by social policy makers' heightened interest in fathers and families, focuses on fatherhood in at least 4 key ways. First, theorists have studied fatherhood as a cultural representation that is expressed through different sociocultural processes and embedded in a larger ecological context. Second, researchers have conceptualized and examined the diverse forms of fatherhood and father involvement. Third, attempts have been made to identify the linkages between dimensions of the father-child relationship and developmental outcomes among children and fathers. Fourth, scholars have explored the father identity as part of a reciprocal process negotiated by men, children, mothers, and other interested parties. Our review highlights research that examines the relationships between dimensions of the father-child relationship and children's well-being and development. We conclude by discussing promising avenues of scholarship for the next generation of research on fatherhood.
TL;DR: In this paper, the perovskite structure is used to illustrate the relationship of structure to composition, and the history of the fundamental science of structure-to-composition is described.
Abstract: Starting with the history of the fundamental science of the relation of structure to composition delineated completely by Goldschmidt, we use the perovskite structure to illustrate the enormous pow...
TL;DR: Alternative strategies, such as food enrichment and the use of biotechnology to manipulate the EPA and DHA as well as ALA contents of the food supply, will become increasingly important in increasing n-3 fatty acid intake in the US population.
TL;DR: In this article, the authors employ a Bayesian dynamic latent factor model to estimate common components in main macroeconomic aggregates (output, consumption and investment) in a sixty-country sample covering seven regions of the world.
Abstract: The paper investigates the common dynamic properties of business cycle fluctuations across countries, regions and the world. We employ a Bayesian dynamic latent factor model to estimate common components in main macroeconomic aggregates (output, consumption and investment) in a sixty-country sample covering seven regions of the world. In particular, we simultaneously estimate (i) a dynamic factor common to all aggregates/regions/countries (the world factor); (ii) a set of 7 regional dynamic factors common across aggregates within a region; (iii) 60 country factors to capture dynamic comovement across aggregates within each country; (iv) and a component for each aggregate that captures idiosyncratic dynamics. We decompose the volatility in each aggregate into the fraction due to the world, region, country, and idiosyncratic components. The results indicate that the world factor is an important source of volatility for aggregates in most countries, providing evidence for a world business cycle. We find that the region-specific factor plays only a minor role in explaining fluctuations in economic activity. While the world and regional factors together account for a larger share of fluctuations in output than in consumption, the country factor along with the idiosyncratic factor play a much larger role in explaining investment dynamics. We also compare and contrast how the three aggregates in each country relate to the world, region and country factors, and document similarities and differences across regions, countries and aggregates. We link the empirical results to the economic structure of the countries in the sample.
Proceedings Article•
01 Jan 2000TL;DR: It is shown that nets with excess capacity generalize well when trained with backprop and early stopping, and that conjugate gradient can yield worse generalization because it overfits regions of low non-linearity when learning to fit regions of high non- linearity.
Abstract: The conventional wisdom is that backprop nets with excess hidden units generalize poorly. We show that nets with excess capacity generalize well when trained with backprop and early stopping. Experiments suggest two reasons for this: 1) Overfitting can vary significantly in different regions of the model. Excess capacity allows better fit to regions of high non-linearity, and backprop often avoids overfitting the regions of low non-linearity. 2) Regardless of size, nets learn task subcomponents in similar sequence. Big nets pass through stages similar to those learned by smaller nets. Early stopping can stop training the large net when it generalizes comparably to a smaller net. We also show that conjugate gradient can yield worse generalization because it overfits regions of low non-linearity when learning to fit regions of high non-linearity.
TL;DR: In this paper, an electric-field assisted assembly technique was used to position individual nanowires suspended in a dielectric medium between two electrodes defined lithographically on a SiO2 substrate.
Abstract: This letter describes an electric-field assisted assembly technique used to position individual nanowires suspended in a dielectric medium between two electrodes defined lithographically on a SiO2 substrate. During the assembly process, the forces that induce alignment are a result of nanowire polarization in the applied alternating electric field. This alignment approach has facilitated rapid electrical characterization of 350- and 70-nm-diameter Au nanowires, which had room-temperature resistivities of approximately 2.9 and 4.5×10−6 Ω cm.
TL;DR: In this paper, the authors investigate whether brand names are more valuable online or in traditional supermarkets and whether the increasing availability of comparative price information online makes consumers more price-sensitive, and find that brand names become more important online in some categories but not in others depending on the extent of information available to consumers.