Showing papers by "Florida State University published in 2002"
TL;DR: This paper contributes by proposing and validating measures for a multidisciplinary, multidimensional model of trust in e-commerce, which shows that trust is indeed a multiddimensional concept.
Abstract: Evidence suggests that consumers often hesitate to transact with Web-based vendors because of uncertainty about vendor behavior or the perceived risk of having personal information stolen by hackers. Trust plays a central role in helping consumers overcome perceptions of risk and insecurity. Trust makes consumers comfortable sharing personal information, making purchases, and acting on Web vendor advice--behaviors essential to widespread adoption of e-commerce. Therefore, trust is critical to both researchers and practitioners. Prior research on e-commerce trust has used diverse, incomplete, and inconsistent definitions of trust, making it difficult to compare results across studies. This paper contributes by proposing and validating measures for a multidisciplinary, multidimensional model of trust in e-commerce. The model includes four high-level constructs--disposition to trust, institution-based trust, trusting beliefs, and trusting intentions--which are further delineated into 16 measurable, literature-grounded subconstructs. The psychometric properties of the measures are demonstrated through use of a hypothetical, legal advice Web site. The results show that trust is indeed a multidimensional concept. Proposed relationships among the trust constructs are tested (for internal nomological validity), as are relationships between the trust constructs and three other e-commerce constructs (for external nomological validity)--Web experience, personal innovativeness, and Web site quality. Suggestions for future research as well as implications for practice are discussed.
4,526 citations
TL;DR: In this article, the authors used the Total Ozone Mapping Spectrometer (TOMS) sensor on the Nimbus 7 satellite to map the global distribution of major atmospheric dust sources with the goal of identifying common environmental characteristics.
Abstract: [1] We use the Total Ozone Mapping Spectrometer (TOMS) sensor on the Nimbus 7 satellite to map the global distribution of major atmospheric dust sources with the goal of identifying common environmental characteristics The largest and most persistent sources are located in the Northern Hemisphere, mainly in a broad “dust belt” that extends from the west coast of North Africa, over the Middle East, Central and South Asia, to China There is remarkably little large-scale dust activity outside this region In particular, the Southern Hemisphere is devoid of major dust activity Dust sources, regardless of size or strength, can usually be associated with topographical lows located in arid regions with annual rainfall under 200–250 mm Although the source regions themselves are arid or hyperarid, the action of water is evident from the presence of ephemeral streams, rivers, lakes, and playas Most major sources have been intermittently flooded through the Quaternary as evidenced by deep alluvial deposits Many sources are associated with areas where human impacts are well documented, eg, the Caspian and Aral Seas, Tigris-Euphrates River Basin, southwestern North America, and the loess lands in China Nonetheless, the largest and most active sources are located in truly remote areas where there is little or no human activity Thus, on a global scale, dust mobilization appears to be dominated by natural sources Dust activity is extremely sensitive to many environmental parameters The identification of major sources will enable us to focus on critical regions and to characterize emission rates in response to environmental conditions With such knowledge we will be better able to improve global dust models and to assess the effects of climate change on emissions in the future It will also facilitate the interpretation of the paleoclimate record based on dust contained in ocean sediments and ice cores
2,653 citations
TL;DR: Findings provide prospective evidence to support the prediction that positive emotions initiate upward spirals toward enhanced emotional well-being.
Abstract: The broaden-and-build theory of positive emotions pre- dicts that positive emotions broaden the scopes of attention and cogni- tion, and, by consequence, initiate upward spirals toward increasing emotional well-being. The present study assessed this prediction by testing whether positive affect and broad-minded coping reciprocally and prospectively predict one another. One hundred thirty-eight col- lege students completed self-report measures of affect and coping at two assessment periods 5 weeks apart. As hypothesized, regression analyses showed that initial positive affect, but not negative affect, predicted improved broad-minded coping, and initial broad-minded coping predicted increased positive affect, but not reductions in nega- tive affect. Further mediational analyses showed that positive affect and broad-minded coping serially enhanced one another. These find- ings provide prospective evidence to support the prediction that posi- tive emotions initiate upward spirals toward enhanced emotional well- being. Implications for clinical practice and health promotion are dis- cussed. Positive emotions feel good. Plus, the balance of people's positive and negative emotions contributes to judgments of life satisfaction (Diener & Larsen, 1993). Are these the only reasons people should care about positive emotions? We think not. We propose that positive emotions not only feel good in the present, but also increase the likeli- hood that one will feel good in the future. That is, we suggest that pos- itive emotions trigger upward spirals toward enhanced emotional well- being. This prediction stems from a new perspective on positive emotions offered within Fredrickson's (1998, 2001) broaden-and-build theory . This model posits that, unlike negative emotions, which narrow people's thought-action repertoires (e.g., fight or flight), positive emo- tions broaden people's thought-action repertoires, encouraging them to discover novel lines of thought or action. Joy, for instance, creates the urge to play, interest creates the urge to explore, and so on. A key, incidental outcome of these broadened mind-sets is an increase in personal resources: As individuals discover new ideas and actions, they build their physical, intellectual, social, and psychological re- sources. Play, for instance, builds physical, socioemotional, and in- tellectual skills, and fuels brain development. Similarly, exploration increases knowledge and psychological complexity (Fredrickson, 1998, 2000).
2,294 citations
TL;DR: These factors, especially web site quality and reputation, are powerful levers that vendors can use to build consumer trust, in order to overcome the negative perceptions people often have about the safety of the web environment.
Abstract: This paper develops and tests a model of consumer trust in an electronic commerce vendor. Building consumer trust is a strategic imperative for web-based vendors because trust strongly influences consumer intentions to transact with unfamiliar vendors via the web. Trust allows consumers to overcome perceptions of risk and uncertainty, and to engage in the following three behaviors that are critical to the realization of a web-based vendor’s strategic objectives: following advice offered by the web vendor, sharing personal information with the vendor, and purchasing from the vendor’s web site. Trust in the vendor is defined as a multi-dimensional construct with two inter-related components—trusting beliefs (perceptions of the competence, benevolence, and integrity of the vendor), and trusting intentions—willingness to depend (that is, a decision to make oneself vulnerable to the vendor). Three factors are proposed for building consumer trust in the vendor: structural assurance (that is, consumer perceptions of the safety of the web environment), perceived web vendor reputation, and perceived web site quality. The model is tested in the context of a hypothetical web site offering legal advice. All three factors significantly influenced consumer trust in the web vendor. That is, these factors, especially web site quality and reputation, are powerful levers that vendors can use to build consumer trust, in order to overcome the negative perceptions people often have about the safety of the web environment. The study also demonstrates that perceived Internet risk negatively affects consumer intentions to transact with a web-based vendor. q 2002 Elsevier Science B.V. All rights reserved.
1,844 citations
TL;DR: The genome-wide program of gene expression during the cell division cycle in a human cancer cell line (HeLa) was characterized using cDNA microarrays to provide a comprehensive catalog of cell cycle regulated genes that can serve as a starting point for functional discovery.
Abstract: The genome-wide program of gene expression during the cell division cycle in a human cancer cell line (HeLa) was characterized using cDNA microarrays. Transcripts of >850 genes showed periodic variation during the cell cycle. Hierarchical clustering of the expression patterns revealed coexpressed groups of previously well-characterized genes involved in essential cell cycle processes such as DNA replication, chromosome segregation, and cell adhesion along with genes of uncharacterized function. Most of the genes whose expression had previously been reported to correlate with the proliferative state of tumors were found herein also to be periodically expressed during the HeLa cell cycle. However, some of the genes periodically expressed in the HeLa cell cycle do not have a consistent correlation with tumor proliferation. Cell cycle-regulated transcripts of genes involved in fundamental processes such as DNA replication and chromosome segregation seem to be more highly expressed in proliferative tumors simply because they contain more cycling cells. The data in this report provide a comprehensive catalog of cell cycle regulated genes that can serve as a starting point for functional discovery. The full dataset is available at http://genome-www.stanford.edu/Human-CellCycle/HeLa/.
1,525 citations
TL;DR: A multi-factor model of compassion fatigue is proposed that emphasizes the costs of caring, empathy, and emotional investment in helping the suffering and suggests that psychotherapists with chronic illness need to develop methods for both enhancing satisfaction and learning to separate from the work emotionally and physically in order to feel renewed.
Abstract: Psychotherapists who work with the chronic illness tend to disregard their own self-care needs when focusing on the needs of clients. The article discusses the concept of compassion fatigue, a form of caregiver burnout among psychotherapists and contrasts it with simple burnout and countertransference. It includes a multi-factor model of compassion fatigue that emphasizes the costs of caring, empathy, and emotional investment in helping the suffering. The model suggests that psychotherapists that limiting compassion stress, dealing with traumatic memories, and more effectively managing case loads are effective ways of avoiding compassion fatigue. The model also suggests that, to limit compassion stress, psychotherapists with chronic illness need to development methods for both enhancing satisfaction and learning to separate from the work emotionally and physically in order to feel renewed. A case study illustrates how to help someone with compassion fatigue.
1,231 citations
Book•
01 Jan 2002TL;DR: In this article, the authors present a self-contained treatment of polymer crystallization, focusing on the thermodynamics and physical properties that accompany the morphological and structural changes that occur when a collection of molecules of very high molecular weight are transformed from one state to another.
Abstract: First published in 2002, from an original 1964 edition, in the Crystallization of Polymers, 2nd edition Leo Mandelkern provides a self-contained treatment of polymer crystallization. All classes of macromolecules are included and the approach is through the basic disciplines of chemistry and physics. The book discusses the thermodynamics and physical properties that accompany the morphological and structural changes that occur when a collection of molecules of very high molecular weight are transformed from one state to another. Volume 1 is a presentation of the equilibrium concepts that serve as a basis for the subsequent volumes. In this volume the author shows that knowledge of the equilibrium requirements is vital to understanding all aspects of the polymer crystallization process, and the final state that eventually evolves. This book will be an invaluable reference work for all chemists, physicists and materials scientists who work in the area of polymer crystallization.
1,206 citations
TL;DR: In this article, the authors examined the ability of the performance-only measurement approach to capture the variance in consumers' overall perceptions of service quality across three studies and concluded that the results from these two studies lent strong support again for the superiority of the Performance-Only approach to the measurement of Service Quality.
918 citations
TL;DR: Using both a market-based and an accrual-based measure of conservatism, this article found that firms facing more severe conflicts over dividend policy tend to use more conservative accounting.
Abstract: Using both a market‐based and an accrual‐based measure of conservatism, we find that firms facing more severe conflicts over dividend policy tend to use more conservative accounting. Furthermore, we document that accounting conservatism is associated with a lower cost of debt after controlling for other determinants of firms' debt costs. Our collective evidence is consistent with the notion that accounting conservatism plays an important role in mitigating bondholder‐shareholder conflicts over dividend policy, and in reducing firms' debt costs.
887 citations
TL;DR: This quantitative study investigated the impact of seven factors related to school technology on five dependent measures in the areas of teacher skill (technology competency and technology integration), teacher morale, and perceived student learning (impact on student content acquisition and higher order thinking skills acquisition).
Abstract: Based on a comprehensive study of 94 classrooms from four states in different geographic regions of the country, this quantitative study investigated the impact of seven factors related to school technology (planning, leadership, curriculum alignment, professional development, technology use, teacher openness to change, and teacher non-school computer use) on five dependent measures in the areas of teacher skill (technology competency and technology integration), teacher morale, and perceived student learning (impact on student content acquisition and higher order thinking skills acquisition). Stepwise regression resulted in models to explain each of the five dependent measures. Teacher technology competency was predicted by teacher openness to change. Technology integration was predicted by teacher openness to change and the percentage of technology use with others. Teacher morale was predicted by professional development and constructivist use of technology. Technology impact on content acquisition was predicted by the strength of leadership, teacher openness to change, and negatively influenced by teacher non-school computer use. Technology impact on higher-order thinking skills was predicted by teacher openness to change, the constructivist use of technology, and negatively influenced by percentage of technology use where students work alone. Implications for the adoption and use of school technologies are discussed.
754 citations
TL;DR: This study models and tests relationships among dynamic, IT-specific individual differences, stable, situation-specific traits and stable, broad traits and suggests that computer anxiety mediates the influence of situation- specific traits on computer self-efficacy.
Abstract: To better understand how individual differences influence the use of information technology (IT), this study models and tests relationships among dynamic, IT-specific individual differences (i.e., computer self-efficacy and computer anxiety), stable, situation-specific traits (i.e., personal innovativeness in IT) and stable, broad traits (i.e., trait anxiety and negative affectivity). When compared to broad traits, the model suggests that situation-specific traits exert a more pervasive influence on IT situation-specific individual differences. Further, the model suggests that computer anxiety mediates the influence of situation-specific traits (i.e., personal innovativeness) on computer self-efficacy. Results provide support for many of the hypothesized relationships. From a theoretical perspective, the findings help to further our understanding of the nomological network among individual differences that lead to computer self-efficacy. From a practical perspective, the findings may help IT managers design training programs that more effectively increase the computer self-efficacy of users with different dispositional characteristics.
TL;DR: Responses were faster when the pictured object's shape matched the shape implied by the sentence than when there was a mismatch, supporting the hypothesis that perceptual symbols are routinely activated in language comprehension.
Abstract: We examined the prediction that people activate perceptual symbols during language comprehension. Subjects read sentences describing an animal or object in a certain location. The shape of the object or animal changed as a function of its location (e.g., eagle in the sky, eagle in a nest). However, this change was only implied by the sentences. After reading a sentence, subjects were presented with a line drawing of the object in question. They judged whether the object had been mentioned in the sentence (Experiment 1) or simply named the object (Experiment 2). In both cases, responses were faster when the pictured object's shape matched the shape implied by the sentence than when there was a mismatch. These results support the hypothesis that perceptual symbols are routinely activated in language comprehension.
TL;DR: High internal, low external participants exhibited lower levels of implicit race bias than did all other participants, and implications for the development of effective self-regulation of race bias are discussed.
Abstract: Three studies examined the moderating role of motivations to respond without prejudice (e.g., internal and external) in expressions of explicit and implicit race bias. In all studies, participants reported their explicit attitudes toward Blacks. Implicit measures consisted of a sequential priming task (Study 1) and the Implicit Association Test (Studies 2 and 3). Study 3 used a cognitive busyness manipulation to preclude effects of controlled processing on implicit responses. In each study, explicit race bias was moderated by internal motivation to respond without prejudice, whereas implicit race bias was moderated by the interaction of internal and external motivation to respond without prejudice. Specifically, high internal, low external participants exhibited lower levels of implicit race bias than did all other participants. Implications for the development of effective self-regulation of race bias are discussed.
TL;DR: The authors found that women who viewed the stereotypic commercials indicated less interest in educational/vocational options in which they were susceptible to stereotype threat (i.e., quantitative domains) and more interest in fields in which women were immune to stereotype threats (e.g., verbal domains), and women taking an aptitude test in Study 2 to avoid math items in favor of verbal items.
Abstract: Women in quantitative fields risk being personally reduced to negative stereotypes that allege a sex-based math inability. This situational predicament, termed stereotype threat, can undermine women’s performance and aspirations in all quantitative domains. Gender-stereotypic television commercials were employed in three studies to elicit the female stereotype among both men and women. Study 1 revealed that only women for whom the activated stereotype was self-relevant underperformed on a subsequent math test. Exposure to the stereotypic commercials led women taking an aptitude test in Study 2 to avoid math items in favor of verbal items. In Study 3, women who viewed the stereotypic commercials indicated less interest in educational/vocational options in which they were susceptible to stereotype threat (i.e., quantitative domains) and more interest in fields in which they were immune to stereotype threat (i.e., verbal domains).
TL;DR: In this paper, the authors provide practical advice about methods to prevent reading failure that is grounded in the new knowledge we have acquired about reading and learning to read over the past two decades.
TL;DR: In this paper, a worldwide compilation of observed SGD shows that groundwater seepage from the land to the ocean occurs in many environments along the world's continental margins, and SGD has a significant influence on the environmental condition of many nearshore marine environments and provides a strong motivation for improved assessments.
Abstract: Coastal hydrogeologists and oceanographers now recognize the potentially significant contribution that submarine groundwater discharge (SGD) could make to the coastal ocean. SGD may be both volumetrically and chemically important to coastal water and chemical budgets. A worldwide compilation of observed SGD shows that groundwater seepage from the land to the ocean occurs in many environments along the world’s continental margins. Further, SGD has a significant influence on the environmental condition of many nearshore marine environments and provides a strong motivation for improved assessments. Our review reveals a critical lack of data from coastal zones of almost all parts of the world, especially in South America, Africa and parts of Asia, making a comprehensive compilation incomplete. SGD should be paid more attention with regard to water and dissolved material budgets at the local and global scales. SGD intercomparison experiments and coastal typologies (classification) may enable evaluation of the accuracy of the SGD estimates and up-scaling of SGD to a global scale. Copyright 2002 John Wiley & Sons, Ltd.
TL;DR: Recent findings concerning the entrainment of clock gene expression in the central nervous system and in peripheral tissues by periodic food access are presented, and the implications of these findings for a better understanding of a circadian system that entrains to meals, rather than to light, are discussed.
Abstract: It is not surprising that limiting food access to a particular time of day has profound effects on the behavior and physiology of animals. It has been clear for some time that pre-meal behavioral activation, a rise in core temperature, elevated serum corticosterone, and an increase in duodenal disaccharidases are under circadian control and that the observed circadian properties are not abolished by lesions of the suprachiasmatic nucleus (SCN), but the search for the locus of a separate food-entrainable oscillator (FEO) has not been successful. The cloning of circadian clock genes and the discovery that these genes are expressed in many central nervous system structures outside the SCN and in peripheral tissues have led to new strategies for investigating potential loci of an FEO. Recent findings concerning the entrainment of clock gene expression in the central nervous system and in peripheral tissues by periodic food access are presented, and the implications of these findings for a better understanding of a circadian system that entrains to meals, rather than to light, are discussed.
TL;DR: The structure of the adeno-associated virus (AAV-2) has been determined to 3-Å resolution by x-ray crystallography and will guide rational engineering of vector capsids to tailor cellular targeting and to avoid immediate neutralization by an immune system sensitized by prior exposure to AAV.
Abstract: The structure of the adeno-associated virus (AAV-2) has been determined to 3-A resolution by x-ray crystallography AAV is being developed as a vector for gene therapy to treat diseases including hemophilia, cancer, and cystic fibrosis As in the distantly related autonomous parvoviruses, the capsid protein has a β-barrel fold, but long loops between the β-strands share little structural homology with other parvoviruses, leading to unique surface features Most prominent are groups of threefold-related peaks, each an intimate association of loops from two neighboring subunits Mutations affecting cell entry and receptor binding are clustered near the positively charged side of each peak, implicating the region in attachment to the cellular receptor, heparan sulfate proteoglycan Amino acids involved in antibody binding are in the same general vicinity The structure will guide rational engineering of vector capsids to tailor cellular targeting and to avoid immediate neutralization by an immune system sensitized by prior exposure to AAV
TL;DR: This article examined the relations of six different conceptualizations of the home literacy environment to oral language, phonological sensitivity, and early literacy development in a longitudinal sample of 115 preschoolers, and found that each of the conceptualizations was consistently related to the outcomes studied.
Abstract: The home literacy environment (HLE) is an important variable in the development of a number of developmental and educational outcomes; however, a number of questions concerning its conceptualization and relations to diverse outcomes are unanswered. This study examined the relations of six different conceptualizations of the HLE to oral language, phonological sensitivity, and early literacy development in a longitudinal sample of 115 preschoolers. Multiple regression and correlational analyses indicated that each of the HLE conceptualizations was consistently related to the outcomes studied. However, the magnitude of the relations varied considerably across outcomes and when other developmental predictors were taken into account. These results indicate that future examinations of the HLE and its role in the development of language and literacy skills need to take into account the manner in which the home environment is conceptualized.
El contexto de alfabetizacion del hogar (HLE) es una variable importante en el desarrollo de una cantidad de consecuencias evolutivas y educativas; sin embargo hay un gran numero de interrogantes sin respuesta referidos a su conceptualizacion y relaciones con los diversos efectos. Este estudio examino las relaciones de seis conceptualizaciones diferentes del HLE con el lenguaje oral, la sensibilidad fonologica y el desarrollo temprano de la lectoescritura en una muestra longitudinal de 115 ninos de Jardin. Los analisis de regresion multiple y correlacionales indicaron que cada una de las conceptualizaciones del HLE se relaciono consistentemente con los efectos estudiados. Sin embargo, la magnitud de las relaciones vario considerablemente segun los efectos, asi como tambien cuando se tuvieron en cuenta otros predictores evolutivos. Estos resultados indican que los estudios futuros sobre el HLE y su papel en el desarrollo de las habilidades de lenguaje y lectoescritura deben tomar en consideracion la forma en la que se conceptualiza el contexto del hogar.
Die hausliche Schreib- und Leseumgebung (HLE = Home Literacy Environment) ist ein wichtiger Faktor bei der Gestaltung einer Anzahl entwicklungsbedingter und erzieherischer Folgeergebnisse; dennoch bleiben viele Fragen in Bezug auf ihre Konzeptualisierung und Relationen zu verschiedenen Auswirkungen unbeantwortet. Diese Studie untersucht die Relationen von sechs verschiedenen Konzeptualisierungen der HLE zur gesprochenen Sprache, phonologischen Sensitivitat und fruher Schreib- und Leseentwicklungen in einem Langzeitbeispiel mit 115 Vorschulern. Mehrfachregression und Korrelationsanalysen zeigten, dass jede der HLE Konzeptualisierungen mit den untersuchten Ergebnissen ubereinstimmte. Jedoch variierte das Ausmas der Beziehungen betrachtlich quer durch die Ergebnisse und sobald andere Entwicklungseinflusse in Rechnung gezogen wurden. Diese Ergebnisse zeigen, das zukunftige Untersuchungen der HLE und deren Rolle in der Entwicklung von Sprache und Schreib- bzw. Lesefertigkeiten die Umstande in Rechnung ziehen mussen, in der die hausliche Umgebung konzeptualisiert ist.
L'environnement ecrit familial (EEF) est une variable importante du developpement de nombreux aspects du developpement et del'education toutefois, nombre de questions concernant sa conceptualisation et ses relations avec differents aspects demeurent sans reponses. Cette etude a porte sur les relations de six conceptualisations differentes de l'EEF sur le langage oral, la sensibilite phonologique, et les premiers developpements de la litteratie a l'aide d'un echantillon de 115 enfantsd'âge prescolaire suivis longitudinalement. Des analyses de regression multiple et des correlations ont montre que chacune des conceptualisations de l'EEF est fortement liee aux aspects etudies. Cependant, l'ampleur de ces relations varie considerablement d'un aspect a l'autre et quand d'autres predicteurs du developpement sont pris en consideration. Ces resultats montrent que les etudes ulterieures de l'EEF et de son role sur le developpement des competences en matiere de langage et de litteratie devront prendre en consideration la facon dont on conceptualise l'environnement familial.
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TL;DR: A review of the current state of observational, theoretical, and modeling knowledge of the midlatitude storm tracks of the Northern Hemisphere cool season can be found in this article, where the roles played by baroclinic processes, linear instability, downstream development, barotropic modulation, and diabatic heating are discussed.
Abstract: This paper reviews the current state of observational, theoretical, and modeling knowledge of the midlatitude storm tracks of the Northern Hemisphere cool season. Observed storm track structures and variations form the first part of the review. The climatological storm track structure is described, and the seasonal, interannual, and interdecadal storm track variations are discussed. In particular, the observation that the Pacific storm track exhibits a marked minimum during midwinter when the background baroclinicity is strongest, and a new finding that storm tracks exhibit notable variations in their intensity on decadal timescales, are highlighted as challenges that any comprehensive storm track theory or model has to be able to address. Physical processes important to storm track dynamics make up the second part of the review. The roles played by baroclinic processes, linear instability, downstream development, barotropic modulation, and diabatic heating are discussed. Understanding of these processes forms the core of our current theoretical knowledge of storm track dynamics, and provides a context within which both observational and modeling results can be interpreted. The eddy energy budget is presented to show that all of these processes are important in the maintenance of the storm tracks. The final part of the review deals with the ability to model storm tracks. The success as well as remaining problems in idealized storm track modeling, which is based on a linearized dynamical system, are discussed. Perhaps on a more pragmatic side, it is pointed out that while the current generation of atmospheric general circulation models faithfully reproduce the climatological storm track structure, and to a certain extent, the seasonal and ENSO-related interannual variations of storm tracks, in-depth comparisons between observed and modeled storm track variations are still lacking.
TL;DR: In this article, the authors examine the emergence of local cooperative institutions that resolve collective action problems involved in the management of natural resources, and demonstrate that watershed partnerships are most likely to emerge in watersheds confronting severe pollution problems associated with agricultural and urban runoff, with low levels of command and control enforcement, and containing the resources to offset transaction costs.
Abstract: This paper examines the emergence of local cooperative institutions--watershed partnerships-that resolve collective action problems involved in the management of natural resources. The political contracting approach to institutional supply suggests that watershed partnerships are more likely to emerge when potential benefits outweigh the transaction costs of developing and maintaining new institutions. We analyze the impact of social, political, economic, and ecological features of watersheds that affect benefits and transaction costs on the emergence of 958 watershed partnerships in the more than 2,100 watersheds in the United States. Our findings demonstrate that watershed partnerships are most likely to emerge in watersheds confronting severe pollution problems associated with agricultural and urban runoff, with low levels of command-and-control enforcement, and containing the resources to offset transaction costs.
TL;DR: The recent evolution of many vent and seep invertebrate species suggests that Cenozoic tectonic history and oceanic circulation patterns have been important in defining contemporary biogeographic patterns.
Abstract: Deep-sea hydrothermal vents and cold seeps are submarine springs where nutrient-rich fluids emanate from the sea floor. Vent and seep ecosystems occur in a variety of geological settings throughout the global ocean and support food webs based on chemoautotrophic primary production. Most vent and seep invertebrates arrive at suitable habitats as larvae dispersed by deep-ocean currents. The recent evolution of many vent and seep invertebrate species (<100 million years ago) suggests that Cenozoic tectonic history and oceanic circulation patterns have been important in defining contemporary biogeographic patterns.
TL;DR: In this article, two different forms of CZMs (exponential and bilinear) are used to evaluate the response of interfaces in titanium matrix composites reinforced by silicon carbide (SCS-6) fibers.
TL;DR: The Alliance Treaty Obligations and Provisions (ATOP) dataset as mentioned in this paper is a large-scale dataset of alliance formation data from the years 1815-1944, which covers the years of the First World War and reveals interesting trends in alliance politics.
Abstract: This article introduces the Alliance Treaty Obligations and Provisions (ATOP) dataset. We begin by describing the rationale for collecting the ATOP data, its scope, and some general coding rules for the project. Then we offer some descriptive statistics for phase one of the dataset, which covers the years 1815-1944, and reveal some interesting trends in alliance politics. Finally, we replicate a study of alliance formation originally conducted by Lai and Reiter (2000) to demonstrate the effect the use of ATOP data may have on past inferences about alliance politics.
01 Oct 2002
TL;DR: In this article, the authors present a self-contained treatment of polymer crystallization, focusing on the thermodynamics and physical properties that accompany the morphological and structural changes that occur when a collection of molecules of very high molecular weight are transformed from one state to another.
Abstract: First published in 2002, from an original 1964 edition, in the Crystallization of Polymers, 2nd edition Leo Mandelkern provides a self-contained treatment of polymer crystallization. All classes of macromolecules are included and the approach is through the basic disciplines of chemistry and physics. The book discusses the thermodynamics and physical properties that accompany the morphological and structural changes that occur when a collection of molecules of very high molecular weight are transformed from one state to another. Volume 1 is a presentation of the equilibrium concepts that serve as a basis for the subsequent volumes. In this volume the author shows that knowledge of the equilibrium requirements is vital to understanding all aspects of the polymer crystallization process, and the final state that eventually evolves. This book will be an invaluable reference work for all chemists, physicists and materials scientists who work in the area of polymer crystallization.
TL;DR: It is proposed that a new field, comparative quantitative genetics, has emerged and the strengths and weaknesses of the many statistical and conceptual approaches now being employed are compared.
Abstract: Quantitative genetics provides one of the most promising frameworks with which to unify the fields of macroevolution and microevolution. The genetic variance–covariance matrix ( G ) is crucial to quantitative genetic predictions about macroevolution. In spite of years of study, we still know little about how G evolves. Recent studies have been applying an increasingly phylogenetic perspective and more sophisticated statistical techniques to address G matrix evolution. We propose that a new field, comparative quantitative genetics, has emerged. Here we summarize what is known about several key questions in the field and compare the strengths and weaknesses of the many statistical and conceptual approaches now being employed. Past studies have made it clear that the key question is no longer whether G evolves but rather how fast and in what manner. We highlight the most promising future directions for this emerging field.
TL;DR: It is reported here that centrally and peripherally administered GLP-1R agonists dose-dependently increased blood pressure and heart rate and this suggests that the central GLp-1 system represents a regulator of sympathetic outflow leading to downstream activation of cardiovascular responses in vivo.
Abstract: Glucagon-like peptide-1 (GLP-1) released from the gut functions as an incretin that stimulates insulin secretion. GLP-1 is also a brain neuropeptide that controls feeding and drinking behavior and gastric emptying and elicits neuroendocrine responses including development of conditioned taste aversion. Although GLP-1 receptor (GLP-1R) agonists are under development for the treatment of diabetes, GLP-1 administration may increase blood pressure and heart rate in vivo. We report here that centrally and peripherally administered GLP-1R agonists dose-dependently increased blood pressure and heart rate. GLP-1R activation induced c-fos expression in the adrenal medulla and neurons in autonomic control sites in the rat brain, including medullary catecholamine neurons providing input to sympathetic preganglionic neurons. Furthermore, GLP-1R agonists rapidly activated tyrosine hydroxylase transcription in brainstem catecholamine neurons. These findings suggest that the central GLP-1 system represents a regulator of sympathetic outflow leading to downstream activation of cardiovascular responses in vivo.
TL;DR: In this article, the authors proposed a theory of the combined influence of corporate and endorser credibility, and found that the dual credibility model partially predicts and explains advertising effectiveness for these dual sources of credibility.
Abstract: This study proposes a theory of the combined influence of corporate and endorser credibility. Participants assessed the credibility of the companies and spokespersons as well as their attitudes toward the ads and brands, and their intent to purchase the advertised product. The covariance matrix was subjected to a path analysis. The model fit the data, and the findings corroborated prior research indicating that both types of source credibility have an impact on attitudes and purchase intentions albeit a differential one. The results suggest that the Dual Credibility Model partially predicts and explains advertising effectiveness for these dual sources of credibility.
TL;DR: Data demonstrate that IL-6 measured 6 h after injury accurately predicts mortality resulting from experimental sepsis, and this measurement may be determined quickly so that therapy may be targeted only to those individuals at significant risk of dying and initiated within sufficient time to be effective.
Abstract: Virtually of the all recent therapeutic interventions for treating sepsis have failed to improve survival. One potential explanation is that the heterogeneity of the immune response to the septic challenge is such that only a portion of the patients die as a result of excessive inflammation.
TL;DR: Overfishing can create trophic cascades in marine communities that cause similar declines in species richness, and the possible overexploitation of engineering species requires more attention because the consequences extend beyond their own decline to affect the rest of the ecosystem.
Abstract: Overfishing is a major environmental problem in the oceans. In addition to the direct loss of the exploited species, the very act of fishing, particularly with mobile bottom gear, destroys habitat and ultimately results in the loss of biodiversity. Furthermore, overfishing can create trophic cascades in marine communities that cause similar declines in species richness. These effects are compounded by indirect effects on habitat that occur through removal of ecological or ecosystem engineers. Mass removal of species that restructure the architecture of habitat and thus increase its complexity or influence the biogeochemistry of sediments could have devastating effects on local biodiversity and important water–sediment processes. The possible overexploitation of engineering species requires more attention because the consequences extend beyond their own decline to affect the rest of the ecosystem. This is particularly problematic in the deep ocean, where oil and gas exploration and fishing pressure are likely to increase.