Showing papers by "Washington State University published in 2000"

Biotic invasions: causes, epidemiology, global consequences, and control

Abstract: Biotic invaders are species that establish a new range in which they proliferate, spread, and persist to the detriment of the environment. They are the most important ecological outcomes from the unprecedented alterations in the distribution of the earth's biota brought about largely through human transport and commerce. In a world without borders, few if any areas remain sheltered from these im- migrations. The fate of immigrants is decidedly mixed. Few survive the hazards of chronic and stochastic forces, and only a small fraction become naturalized. In turn, some naturalized species do become invasive. There are several potential reasons why some immigrant species prosper: some escape from the constraints of their native predators or parasites; others are aided by human-caused disturbance that disrupts native communities. Ironically, many biotic invasions are apparently facilitated by cultivation and husbandry, unintentional actions that foster immigrant populations until they are self-perpetuating and uncontrollable. Whatever the cause, biotic invaders can in many cases inflict enormous environmental damage: (1) Animal invaders can cause extinctions of vulnerable native species through predation, grazing, competition, and habitat alteration. (2) Plant invaders can completely alter the fire regime, nutrient cycling, hydrology, and energy budgets in a native ecosystem and can greatly diminish the abundance or survival of native species. (3) In agriculture, the principal pests of temperate crops are nonindigenous, and the combined expenses of pest control and crop losses constitute an onerous "tax" on food, fiber, and forage production. (4) The global cost of virulent plant and animal diseases caused by parasites transported to new ranges and presented with susceptible new hosts is currently incalculable. Identifying future invaders and taking effective steps to prevent their dispersal and establishment con- stitutes an enormous challenge to both conservation and international commerce. Detection and management when exclusion fails have proved daunting for varied reasons: (1) Efforts to identify general attributes of future invaders have often been inconclusive. (2) Predicting susceptible locales for future invasions seems even more problematic, given the enormous differences in the rates of arrival among potential invaders. (3) Eradication of an established invader is rare, and control efforts vary enormously in their efficacy. Successful control, however, depends more on commitment and continuing diligence than on the efficacy of specific tools themselves. (4) Control of biotic invasions is most effective when it employs a long-term, ecosystem- wide strategy rather than a tactical approach focused on battling individual invaders. (5) Prevention of invasions is much less costly than post-entry control. Revamping national and international quarantine laws by adopting a "guilty until proven innocent" approach would be a productive first step. Failure to address the issue of biotic invasions could effectively result in severe global consequences, including wholesale loss of agricultural, forestry, and fishery resources in some regions, disruption of the ecological processes that supply natural services on which human enterprise depends, and the creation of homogeneous, impoverished ecosystems composed of cosmopolitan species. Given their current scale, biotic invasions have taken their place alongside human-driven atmospheric and oceanic alterations as major agents of global change. Left unchecked, they will influence these other forces in profound but still unpredictable ways.

New Trends in Measuring Environmental Attitudes: Measuring Endorsement of the New Ecological Paradigm: A Revised NEP Scale

Abstract: Dunlap and Van Liere's New Environmental Paradigm (NEP) Scale, published in 1978, has become a widely used measure of proenvironmental orientation. This article develops a revised NEP Scale designed to improve upon the original one in several respects: (1) It taps a wider range of facets of an ecological worldview, (2) It offers a balanced set of pro- and anti-NEP items, and (3) It avoids outmoded terminology. The new scale, termed the New Ecological Paradigm Scale, consists of 15 items. Results of a 1990 Washington State survey suggest that the items can be treated as an internally consistent summated ratingscale and also indicate a modest growth in pro-NEP responses among Washington residents over the 14 years since the original study.

Identity theory and social identity theory

Abstract: In social psychology, we need to establish a general theory of the self which can attend to both macro and micro processes, and which avoids the redundancies of separate theories on different aspects of the self For this purpose, we present core components of identity theory and social identity theory and argue that although differences exist between the two theories, they are more differences in emphasis than in kind, and that linking the two theories can establish a more fully integrated view of the self The core components we examine include the different bases of identity (category/group or role) in each of the theories, identity salience and the activation of identities as discussed in the theories, and the cognitive and motivational processes that emerge from identities based on category/group and on role. By examining the self through the lens of both identity theory and social identity theory, we see how, in combination, they can move us toward a general theory of the self In contrast to Hogg and his colleagues (Hogg, Terry, and White 1995), we see substantial similarities and overlap between social identity theory and identity theory. We think that this overlap ultimately will cause these theories to be linked in fundamental ways, though we do not think that time has

The Past, Present, and Future of an Identity Theory*

Abstract: Among the many traditions of research on "identity," two somewhat different yet strongly related strands of identity theory have developed. The first, reflected in the work of Stryker and colleagues, focuses on the linkages of social structures with identities. The second, reflected in the work of Burke and colleagues, focuses on the internal process of self-verification. In the present paper we review each of these strands and then discuss ways in which the two relate to and complement one another Each provides a context for the other: the relation of social structures to identities influences the process of self-verification, while the process of self-verification creates and sustains social structures. The paper concludes with examples of potentially useful applications of identity theory to other arenas of social psychology, and with a discussion of challenges that identity theory must meet to provide a clear understanding of the relation between self and society. The language of "identity" is ubiquitous in contemporary social science, cutting across psychoanalysis, psychology, political science, sociology, and history. The common usage of the term identity, however, belies the considerable variability in both its conceptual meanings and its theoretical role. Even when consideration is restricted to sociology and social psychology, variation is still considerable.'

The role of genetic and genomic attributes in the success of polyploids

Abstract: In 1950, G. Ledyard Stebbins devoted two chapters of his book Variation and Evolution in Plants (Columbia Univ. Press, New York) to polyploidy, one on occurrence and nature and one on distribution and significance. Fifty years later, many of the questions Stebbins posed have not been answered, and many new questions have arisen. In this paper, we review some of the genetic attributes of polyploids that have been suggested to account for the tremendous success of polyploid plants. Based on a limited number of studies, we conclude: (i) Polyploids, both individuals and populations, generally maintain higher levels of heterozygosity than do their diploid progenitors. (ii) Polyploids exhibit less inbreeding depression than do their diploid parents and can therefore tolerate higher levels of selfing; polyploid ferns indeed have higher levels of selfing than do their diploid parents, but polyploid angiosperms do not differ in outcrossing rates from their diploid parents. (iii) Most polyploid species are polyphyletic, having formed recurrently from genetically different diploid parents. This mode of formation incorporates genetic diversity from multiple progenitor populations into the polyploid “species”; thus, genetic diversity in polyploid species is much higher than expected by models of polyploid formation involving a single origin. (iv) Genome rearrangement may be a common attribute of polyploids, based on evidence from genome in situ hybridization (GISH), restriction fragment length polymorphism (RFLP) analysis, and chromosome mapping. (v) Several groups of plants may be ancient polyploids, with large regions of homologous DNA. These duplicated genes and genomes can undergo divergent evolution and evolve new functions. These genetic and genomic attributes of polyploids may have both biochemical and ecological benefits that contribute to the success of polyploids in nature.

Isoprenoid biosynthesis: The evolution of two ancient and distinct pathways across genomes

Abstract: Isopentenyl diphosphate (IPP) is the central intermediate in the biosynthesis of isoprenoids, the most ancient and diverse class of natural products. Two distinct routes of IPP biosynthesis occur in nature: the mevalonate pathway and the recently discovered deoxyxylulose 5-phosphate (DXP) pathway. The evolutionary history of the enzymes involved in both routes and the phylogenetic distribution of their genes across genomes suggest that the mevalonate pathway is germane to archaebacteria, that the DXP pathway is germane to eubacteria, and that eukaryotes have inherited their genes for IPP biosynthesis from prokaryotes. The occurrence of genes specific to the DXP pathway is restricted to plastid-bearing eukaryotes, indicating that these genes were acquired from the cyanobacterial ancestor of plastids. However, the individual phylogenies of these genes, with only one exception, do not provide evidence for a specific affinity between the plant genes and their cyanobacterial homologues. The results suggest that lateral gene transfer between eubacteria subsequent to the origin of plastids has played a major role in the evolution of this pathway.

The Arabidopsis male-sterile mutant, opr3, lacks the 12-oxophytodienoic acid reductase required for jasmonate synthesis.

Abstract: Jasmonic acid (JA) and its precursor 12-oxophytodienoic acid (OPDA) act as plant growth regulators and mediate responses to environmental cues. To investigate the role of these oxylipins in anther and pollen development, we characterized a T-DNA-tagged, male-sterile mutant of Arabidopsis, opr3. The opr3 mutant plants are sterile but can be rendered fertile by exogenous JA but not by OPDA. Cloning of the mutant locus indicates that it encodes an isozyme of 12-oxophytodienoate reductase, designated OPR3. All of the defects in opr3 are alleviated by transformation of the mutant with an OPR3 cDNA. Our results indicate that JA and not OPDA is the signaling molecule that induces and coordinates the elongation of the anther filament, the opening of the stomium at anthesis, and the production of viable pollen. Just as importantly, our data demonstrate that OPR3 is the only isoform of OPR capable of reducing the correct stereoisomer of OPDA to produce JA required for male gametophyte development.

Randomized trial of intensive early intervention for children with pervasive developmental disorder.

Abstract: Young children with pervasive developmental disorder were randomly assigned to intensive treatment or parent training. The intensive treatment group (7 with autism, 8 with pervasive developmental disorder not otherwise specified—NOS) averaged 24.52 hours per week of individual treatment for one year, gradually reducing hours over the next 1 to 2 years. The parent training group (7 with autism, 6 with pervasive developmental disorder NOS) received 3 to 9 months of parent training. The groups appeared similar at intake on all measures; however, at follow-up the intensive treatment group outperformed the parent training group on measures of intelligence, visual-spatial skills, language, and academics, though not adaptive functioning or behavior problems. Children with pervasive developmental disorder NOS may have gained more than those with autism.

Passive transfer of colostral immunoglobulins in calves.

Abstract: Passive transfer of colostral immunoglobulins has long been accepted as imperative to optimal calf health Many factors, including timing of colostrum ingestion, the method and volume of colostrum administration, the immunoglobulin concentration of the colostrum ingested, and the age of the dam have been implicated in affecting the optimization of absorption The practice of colostrum pooling, the breed and presence of the dam, and the presence of respiratory acidosis in the calf also may affect passive transfer Various tests have been reported to accurately measure passive transfer status in neonatal calves The radial immunodiffusion and the enzyme-linked immunosorbent assay (ELISA) are the only tests that directly measure serum IgG concentration All other available tests including serum total solids by refractometry, sodium sulfite turbidity test, zinc sulfate turbidity test, serum gamma-glutamyl transferase activity, and whole blood glutaraldehyde gelation estimate serum IgG concentration based on concentration of total globulins or other proteins whose passive transfer is statistically associated with that of IgG This paper presents a comprehensive review of the literature of passive transfer in calves including factors that affect passive transfer status, testing modalities, effects of failure of passive transfer on baseline mortality, consequences of failure of passive transfer, and some treatment options Many previously accepted truisms regarding passive transfer in calves should be rejected based on the results of recent research

Patterns of genetic variation in rare and widespread plant congeners

Abstract: Rare species are typically considered to maintain low levels of genetic variation, and this view has been supported by several reviews of large numbers of isozyme studies. Although these reviews have provided valuable data on levels of variability in plant species in general, and rare species in particular, these broad overviews involve comparisons that may confound the effects of rarity with a multitude of other factors that affect genetic variability. Additionally, the statistical analyses employed assume the data to be independent, which is not the case for organisms that share a common phylogenetic history. As the role of evolutionary history and historical constraints has become better understood, more researchers have studied widespread congeners when investigating the genetic diversity of rare species in an effort to control for these effects. We summarize the available data from such studies, comparing for rare and widespread congeners (1) the levels of genetic variability at the population and species levels and (2) measures of population substructuring. At the population level, we summarized data for percentage polymorphic loci (%P(pop)), mean number of alleles per locus (A(pop)), and observed heterozygosity (H(o)). Species-level measures used were percentage polymorphic loci (%P(spp)), mean number of alleles per locus (A(spp)), and total genetic diversity (H(T)). Indices of population subdivision (either F(ST) or G(ST)) were also examined. Using Wilcoxon signed rank tests, we found significant, but small, differences between rare and widespread species for all diversity measures except H(T). However, there does not appear to be a difference between rare and widespread congeners in terms of how genetic variation is partitioned within and among populations. Levels of diversity, for all measures examined, between rare and widespread congeners are highly correlated.

Challenging global warming as a social problem: An analysis of the conservative movement's counter-claims

Abstract: The sociological literature on global environmental change emphasizes the processes by which the problem of global warming is socially constructed. However, the opposing efforts to construct the “non-problematicity” of global warming advanced by the conservative movement are largely ignored. Utilizing recent work on framing processes in the social movements literature and claims-making from the social problems literature, this paper analyzes the counter-claims promoted by the conservative movement between 1990 and 1997 as it mobilized to challenge the legitimacy of global warming as a social problem. A thematic content analysis of publications circulated on the web sites of prominent conservative think tanks reveals three major counter-claims. First, the movement criticized the evidentiary basis of global warming as weak, if not entirely wrong. Second, the movement argued that global warming will have substantial benefits if it occurs. Third, the movement warned that proposed action to ameliorate global warming would do more harm than good. In short, the conservative movement asserted that, while the science of global warming appears to be growing more and more uncertain, the harmful effects of global warming policy are becoming increasingly certain . In order to better understand the controversy over global warming, future research should pay attention to the influence of the conservative movement by identifying the crucial roles of conservative foundations, conservative think tanks, and sympathetic “skeptic” scientists in undermining the growing scientific consensus over the reality of global warming.

Intrinsic protein disorder in complete genomes.

Abstract: Intrinsic protein disorder refers to segments or to whole proteins that fail to fold completely on their own. Here we predicted disorder on protein sequences from 34 genomes, including 22 bacteria, 7 archaea, and 5 eucaryotes. Predicted disordered segments > or = 50, > or = 40, and > or = 30 in length were determined as well as proteins estimated to be wholly disordered. The five eucaryotes were separated from bacteria and archaea by having the highest percentages of sequences predicted to have disordered segments > or = 50 in length: from 25% for Plasmodium to 41% for Drosophila. Estimates of wholly disordered proteins in the bacteria ranged from 1% to 8%, averaging to 3 +/- 2%, estimates in various archaea ranged from 2 to 11%, plus an apparently anomalous 18%, averaging to 7 +/- 5% that drops to 5 +/- 3% if the high value is discarded. Estimates in the 5 eucarya ranged from 3 to 17%. The putative wholly disordered proteins were often ribosomal proteins, but in addition about equal numbers were of known and unknown function. Overall, intrinsic disorder appears to be a common, with eucaryotes perhaps having a higher percentage of native disorder than archaea or bacteria.

Cold comfort farm: the acclimation of plants to freezing temperatures.

Abstract: Plant acclimation to freezing temperatures is very complex. Many temperate plants increase in freezing tolerance upon exposure to a period of low but non-freezing temperatures, an adaptive process known as cold acclimation. This acclimation phenomenon has encouraged investigations of physiological, biochemical, and molecular changes that are associated with the development of freezing tolerance. Although many biochemical and gene-expression changes occur during cold acclimation, few have been unequivocally demonstrated to contribute to the development of freezing tolerance. However, in the last few years, exciting new progress has been made through the use of mutational analysis and molecular genetic approaches. We now recognize that several interacting signal pathways are activated to bring about cold acclimation and ensure the winter survival of plants. The challenge for the future is to understand these pathways at a mechanistic level. Facile map-based cloning in Arabidopsis and techniques (such as DNA micro-arrays) for transcript profiling will provide the tools needed for this task.

Influence of a Reflective Explicit Activity-based Approach on Elementary Teachers' Conceptions of Nature of Science.

Abstract: This study assessed the influence of a reflective, explicit, activity-based approach to nature of science (NOS) instruction undertaken in the context of an elementary science methods course on pre- service teachers' views of some aspects of NOS. These aspects included the empirical, tentative, subjec- tive (theory-laden), imaginative and creative, and social and cultural NOS. Two additional aspects were the distinction between observation and inference, and the functions of and relationship between scientif- ic theories and laws. Participants were 25 undergraduate and 25 graduate preservice elementary teachers enrolled in two sections of the investigated course. An open-ended NOS questionnaire coupled with indi- vidual interviews was used to assess participants' NOS views before and at the conclusion of the course. The majority of participants held naive views of the target NOS aspects at the beginning of the study. Dur- ing the first week of class, participants were engaged in specially designed activities that were coupled with explicit NOS instruction. Throughout the remainder of the course, participants were provided with structured opportunities to reflect on their views of the target NOS aspects. Postinstruction assessments in- dicated that participants made substantial gains in their views of some of the target NOS aspects. Less sub- stantial gains were evident in the case of the subjective, and social and cultural NOS. The results of the present study support the effectiveness of explicit, reflective NOS instruction. Such instruction, nonethe- less, might be rendered more effective when integrated within a conceptual change approach. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 295 -317, 2000.

Biogenic Hydrocarbons in the Atmospheric Boundary Layer: A Review

Abstract: Nonmethane hydrocarbons are ubiquitous trace atmospheric constituents yet they control the oxidation capacity of the atmosphere. Both anthropogenic and biogenic processes contribute to the release of hydrocarbons to the atmosphere. In this manuscript, the state of the science concerning biosynthesis, transport, and chemical transformation of hydrocarbons emitted by the terrestrial biosphere is reviewed. In particular, the focus is on isoprene, monoterpenes, and oxygen-ated hydrocarbons. The generated science during the last 10 years is reviewed to explain and quantify hydrocarbon emissions from vegetation and to discern impacts of biogenic hydrocarbons on local and regional atmospheric chemistry. Furthermore, the physiological and environmental processes controlling biosynthesis and production of hydrocarbon compounds are reported on. Many advances have been made on measurement and modeling approaches developed to quantify hydrocarbon emissions from leaves and forest ecosystems. A synthesis of the atmospheric chemistry of biogenic hydrocarbons and their role in the formation of oxidants and aerosols is presented. The integration of biogenic hydrocarbon kinetics and atmospheric physics into mathematical modeling systems is examined to assess the contribution of biogenic hydrocarbons to the formation of oxidants and aerosols, thereby allowing us to study their impacts on the earth's climate system and to develop strategies to reduce oxidant precursors in affected regions.

An investigation of factors that influence the management of knowledge in organizations

Abstract: Modern organizations are increasingly seen as knowledge-based enterprises in which proactive knowledge management is important for competitiveness. This paper introduces a descriptive framework for understanding factors that influence the success of knowledge management (KM) initiatives in an organization. It identifies three main classes of influencing factors (managerial, resource, and environmental) and characterizes the individual factors in each class. A Delphi process was used to develop and assess the framework. The Delphi panel was comprised of 31 recognized researchers and practitioners in the KM field. The resultant framework can be used by researchers for KM issue and hypothesis generation, by practitioners for benchmarking KM practices, and by educators for helping organize the study of KM.

Adoption of Internet shopping: the role of consumer innovativeness

Abstract: The projected sales potential for Internet commerce indicates that businesses must understand those consumer characteristics that will influence consumer adoption of this medium for shopping. An empirical study conducted here (n = 403) investigates the extent to which open‐processing (more general innovativeness) and domain‐specific innovativeness explain the conditions under which consumers move from general Internet usage to a product purchase via the Internet. The results of our study find that generally higher amounts of Internet use (for non‐shopping activities) are associated with an increased amount of Internet product purchases. Importantly, however, this relationship is moderated by domain‐specific but not general innovativeness. Implications for business practice and academic research are provided.

Computing contour trees in all dimensions

Abstract: We show that contour trees can be computed in all dimensions by a simple algorithm that merges two trees. Our algorithm extends, simplifies, and improves work of Tarasov and Vyalyi and of van Kreveld et al.

Moral Awareness in Business Organizations: Influences of Issue-Related and Social Context Factors

Abstract: Individuals' awarenessof moral issues is an important first step in the ethicaldecision-making process. Relying on research in social cognition andbusiness ethics, we hypothesized that moral awareness is influenced byissue-related factors (magnitude of consequences of the moral issueand issue framing in moral terms) and social contextrelated factors(competitive context and perceived social consensus that the issue isethically problematic). The hypotheses were tested in a fieldexperiment involving 291competitive intelligence practitioners.Results generally supported the hypotheses. Qualitative analysisyielded additional insights into the content of respondents' moralawareness.