Showing papers by "University of Windsor published in 2009"
TL;DR: Investigation of how the Five-Factor Model of personality relates to Facebook use indicated that personality factors were not as influential as previous literature would suggest, but a motivation to communicate was influential in terms of Facebook use.
1,679 citations
TL;DR: Results indicate some positive findings with respect to reporting practices including proposing multiple models a priori and near universal reporting of the chi-square significance test, but many deficiencies were found such as lack of information regarding missing data and assessment of normality.
Abstract: Reporting practices in 194 confirmatory factor analysis studies (1,409 factor models) published in American Psychological Association journals from 1998 to 2006 were reviewed and compared with established reporting guidelines. Three research questions were addressed: (a) how do actual reporting practices compare with published guidelines? (b) how do researchers report model fit in light of divergent perspectives on the use of ancillary fit indices (e.g., L.-T. Hu & P. M. Bentler, 1999; H. W. Marsh, K.-T., Hau, & Z. Wen, 2004)? and (c) are fit measures that support hypothesized models reported more often than fit measures that are less favorable? Results indicate some positive findings with respect to reporting practices including proposing multiple models a priori and near universal reporting of the chi-square significance test. However, many deficiencies were found such as lack of information regarding missing data and assessment of normality. Additionally, the authors found increases in reported values of some incremental fit statistics and no statistically significant evidence that researchers selectively report measures of fit that support their preferred model. Recommendations for reporting are summarized and a checklist is provided to help editors, reviewers, and authors improve reporting practices.
1,662 citations
TL;DR: The theoretical framework, interrater reliability, and preliminary concurrent validity for this new instrument, the Balance Evaluation Systems Test (BESTest), which aims to target 6 different balance control systems so that specific rehabilitation approaches can be designed for different balance deficits are presented.
Abstract: Background: Current clinical balance assessment tools do not aim to help therapists identify the underlying postural control systems responsible for poor functional balance. By identifying the disordered systems underlying balance control, therapists can direct specific types of intervention for different types of balance problems.
Objective: The goal of this study was to develop a clinical balance assessment tool that aims to target 6 different balance control systems so that specific rehabilitation approaches can be designed for different balance deficits. This article presents the theoretical framework, interrater reliability, and preliminary concurrent validity for this new instrument, the Balance Evaluation Systems Test (BESTest).
Design: The BESTest consists of 36 items, grouped into 6 systems: “Biomechanical Constraints,” “Stability Limits/Verticality,” “Anticipatory Postural Adjustments,” “Postural Responses,” “Sensory Orientation,” and “Stability in Gait.”
Methods: In 2 interrater trials, 22 subjects with and without balance disorders, ranging in age from 50 to 88 years, were rated concurrently on the BESTest by 19 therapists, students, and balance researchers. Concurrent validity was measured by correlation between the BESTest and balance confidence, as assessed with the Activities-specific Balance Confidence (ABC) Scale.
Results: Consistent with our theoretical framework, subjects with different diagnoses scored poorly on different sections of the BESTest. The intraclass correlation coefficient (ICC) for interrater reliability for the test as a whole was .91, with the 6 section ICCs ranging from .79 to .96. The Kendall coefficient of concordance among raters ranged from .46 to 1.00 for the 36 individual items. Concurrent validity of the correlation between the BESTest and the ABC Scale was r =.636, P <.01.
Limitations: Further testing is needed to determine whether: (1) the sections of the BESTest actually detect independent balance deficits, (2) other systems important for balance control should be added, and (3) a shorter version of the test is possible by eliminating redundant or insensitive items.
Conclusions: The BESTest is easy to learn to administer, with excellent reliability and very good validity. It is unique in allowing clinicians to determine the type of balance problems to direct specific treatments for their patients. By organizing clinical balance test items already in use, combined with new items not currently available, the BESTest is the most comprehensive clinical balance tool available and warrants further development.
821 citations
TL;DR: In this paper, a survey of this topic suggests that a desirable solution may be a single surface engineered coating that reduces the incidence of ice adhesion, insect fouling, and protects the blade surface from erosive deterioration.
Abstract: Wind turbine performance can be significantly reduced when the surface integrity of the turbine blades is compromised. Many frontier high-energy regions that are sought for wind farm development including Nordic, warm-humid, and desert-like environments often provide conditions detrimental to the surface of the turbine blade. In Nordic climates ice can form on the blades and the turbine structure itself through a variety of mechanisms. Initial ice adhesion may slightly modify the original aerodynamic profile of the blade; continued ice accretion can drastically affect the structural loading of the entire rotor leading to potentially dangerous situations. In warmer climates, a humid wind is desirable for its increased density; however, it can come at a price when the region supports large populations of insects. Insect collisions with the blades can foul blade surfaces leading to a marked increase in skin drag, reducing power production by as much as 50%. Finally, in more arid regions where there is no threat from ice or insects, high winds can carry soil particles eroded from the ground (abrasive particles). Particulate-laden winds effectively sand-blast the blade surfaces, and disrupt the original skin profile of the blade, again reducing its aerodynamic efficiency. While these problems are challenging, some mitigative measures presently exist and are discussed in the paper. Though, many of the current solutions to ice or insect fouling actually siphon power from the turbine itself to operate, or require that the turbine be stopped, in either case, profitability is diminished. Our survey of this topic in the course of our research suggests that a desirable solution may be a single surface engineered coating that reduces the incidence of ice adhesion, insect fouling, and protects the blade surface from erosive deterioration. Research directions that may lead to such a development are discussed herein.
488 citations
TL;DR: In this paper, the authors consider the tradeoff between connectivity and representation of coral reef biodiversity and provide general recommendations for the location, size and spacing of no-take reserves based on emerging data on larval dispersal in corals and reef fishes, and on considerations for maintaining genetic diversity.
Abstract: Networks of no-take reserves are important for protecting coral reef biodiversity from climate change and other human impacts. Ensuring that reserve populations are connected to each other and non-reserve populations by larval dispersal allows for recovery from disturbance and is a key aspect of resilience. In general, connectivity between reserves should increase as the distance between them decreases. However, enhancing connectivity may often tradeoff against a network’s ability to representatively sample the system’s natural variability. This “representation” objective is typically measured in terms of species richness or diversity of habitats, but has other important elements (e.g., minimizing the risk that multiple reserves will be impacted by catastrophic events). Such representation objectives tend to be better achieved as reserves become more widely spaced. Thus, optimizing the location, size and spacing of reserves requires both an understanding of larval dispersal and explicit consideration of how well the network represents the broader system; indeed the lack of an integrated theory for optimizing tradeoffs between connectivity and representation objectives has inhibited the incorporation of connectivity into reserve selection algorithms. This article addresses these issues by (1) updating general recommendations for the location, size and spacing of reserves based on emerging data on larval dispersal in corals and reef fishes, and on considerations for maintaining genetic diversity; (2) using a spatial analysis of the Great Barrier Reef Marine Park to examine potential tradeoffs between connectivity and representation of biodiversity and (3) describing a framework for incorporating environmental fluctuations into the conceptualization of the tradeoff between connectivity and representation, and that expresses both in a common, demographically meaningful currency, thus making optimization possible.
368 citations
TL;DR: In this paper, a conceptual model of the relationships between organizational and career factors and older workers' intention to remain with their organizations was tested through two studies with diverse samples, and they concluded that implementing training and development practices targeting older workers and tailored to their needs and providing interesting and challenging job assignments are important to perceptions of organizational support and career satisfaction and ultimately to the retention of older workers.
Abstract: Through two studies with diverse samples, we tested a conceptual model of the relationships between organizational and career factors and older workers' intention to remain with their organization. Perceived organizational support mediated the relationship between training and development practices, hierarchical, and job content plateauing and intention to remain. Career satisfaction mediated the relationship between perceived organizational support, job content plateauing, and intention to remain. We conclude that implementing training and development practices targeting older workers and tailored to their needs and providing interesting and challenging job assignments are important to perceptions of organizational support and career satisfaction and ultimately to the retention of older workers.
358 citations
TL;DR: An approach to multiattribute decision making with incomplete attribute weight information where individual assessments are provided as interval-valued intuitionistic fuzzy numbers (IVIFNs) is proposed by employing a series of optimization models.
300 citations
TL;DR: It is supported that shyness was significantly positively correlated with the time spent on Facebook and having favorable attitudes toward the social networking site, and shynesswas significantly negatively correlated withThe number of Facebook "Friends.
Abstract: Researchers have suggested that individual differences will help to determine which online communication tools appeal to and are used by different individuals. With respect to the domain of computer-mediated communication, shyness is a particular personality trait of interest, as forums provide opportunities for social interactions that shy individuals might otherwise avoid. The present study investigated the personality trait of shyness and its relation with certain features of an online communication tool (Facebook). We hypothesized that shyness would be significantly related to the quantity of time spent on Facebook, the number of contacts added to one's Facebook profile, and attitudes toward Facebook. Our findings supported that shyness was significantly positively correlated with the time spent on Facebook and having favorable attitudes toward the social networking site. Furthermore, shyness was significantly negatively correlated with the number of Facebook "Friends.'' Limitations of the present study and suggestions for future research are addressed.
299 citations
TL;DR: A checklist is provided as a guideline so that a network designer can choose an appropriate multipath routing protocol to meet the network's application objectives.
283 citations
TL;DR: Despite the vast amount of recent work on animal iridescence, a review reveals that many proposed functions of iridescent coloration remain virtually unexplored, and this area is clearly ripe for future research.
Abstract: In animals, iridescence is generated by the interaction of light with biological tissues that are nanostructured to produce thin films or diffraction gratings. Uniquely among animal visual signals, the study of iridescent coloration contributes to biological and physical sciences by enhancing our understanding of the evolution of communication strategies, and by providing insights into physical optics and inspiring biomimetic technologies useful to humans. Iridescent colours are found in a broad diversity of animal taxa ranging from diminutive marine copepods to terrestrial insects and birds. Iridescent coloration has received a surge of research interest of late, and studies have focused on both characterizing the nanostructures responsible for producing iridescence and identifying the behavioural functions of iridescent colours. In this paper, we begin with a brief description of colour production mechanisms in animals and provide a general overview of the taxonomic distribution of iridescent colours. We then highlight unique properties of iridescent signals and review the proposed functions of iridescent coloration, focusing, in particular, on the ways in which iridescent colours allow animals to communicate with conspecifics and avoid predators. We conclude with a brief overview of non-communicative functions of iridescence in animals. Despite the vast amount of recent work on animal iridescence, our review reveals that many proposed functions of iridescent coloration remain virtually unexplored, and this area is clearly ripe for future research.
276 citations
TL;DR: In this paper, a brief history of business games, the changing technology employed in the development and use of business game, changes in why business games are adopted and used and changes in how business game are administered, and the current state of business gaming.
Abstract: This article examines developments in business simulation gaming during the past 40 years. Covered in this article are a brief history of business games, the changing technology employed in the development and use of business games, changes in why business games are adopted and used, changes in how business games are administered, and the current state of business gaming. Readers interested in developments in other areas of simulation gaming (urban planning, social studies, ecology, economics, geography, health, etc.) are encouraged to look at other articles appearing during the 40th anniversary year of Simulation & Gaming and at the many fine articles that appeared in the silver anniversary issue of Simulation & Gaming (December 1995).
TL;DR: In this article, the authors compared emotional display rules of Canadian, US Americans, and Japanese across cultures regarding the specific emotion, the type of interaction partner, and gender, finding that Japanese display rules permit the expression of powerful (anger, contempt, and disgust) significantly less than those of the two North American samples.
Abstract: This study investigates emotional display rules for seven basic emotions. The main goal was to compare emotional display rules of Canadians, US Americans, and Japanese across as well as within cultures regarding the specific emotion, the type of interaction partner, and gender. A total of 835 university students participated in the study. The results indicate that Japanese display rules permit the expression of powerful (anger, contempt, and disgust) significantly less than those of the two North American samples. Japanese also think that they should express positive emotions (happiness, surprise) significantly less than the Canadian sample. Furthermore, Japanese varied the display rules for different interaction partners more than the two North American samples did only for powerful emotions. Gender differences were similar across all three cultural groups. Men expressed powerful emotions more than women and women expressed powerless emotions (sadness, fear) and happiness more than men. Depending on the type of emotion and interaction partner some shared display rules occurred across culture and gender. The implications of these findings are discussed in relation to cultural dimensions and other cultural characteristics.
01 Jun 2009
TL;DR: This paper has proposed an efficient solution, based on a genetic algorithm (GA), for scheduling the data gathering of relay nodes, which can significantly extend the lifetime of a relay node network.
Abstract: Higher power relay nodes can be used as cluster heads in two-tiered sensor networks to achieve improved network lifetime. The relay nodes may form a network among themselves to route data towards the base station. In this model, the lifetime of a network is determined mainly by the lifetimes of these relay nodes. An energy-aware communication strategy can greatly extend the lifetime of such networks. However, integer linear program (ILP) formulations for optimal, energy-aware routing quickly become computationally intractable and are not suitable for practical networks. In this paper, we have proposed an efficient solution, based on a genetic algorithm (GA), for scheduling the data gathering of relay nodes, which can significantly extend the lifetime of a relay node network. For smaller networks, where the global optimum can be determined, our GA based approach is always able to find the optimal solution. Furthermore, our algorithm can easily handle large networks, where it leads to significant improvements compared to traditional routing schemes.
TL;DR: Developing a psychometrically sound measure of cohesion for youth sport groups through focus groups, open-ended questionnaires, and a literature review is initiated.
Abstract: The purpose of the current study was to initiate the development of a psychometrically sound measure of cohesion for youth sport groups. A series of projects were undertaken in a four-phase research program. The initial phase was designed to garner an understanding of how youth sport group members perceived the concept of cohesion through focus groups (n = 56), open-ended questionnaires (n = 280), and a literature review. In Phase 2, information from the initial projects was used in the development of 142 potential items and content validity was assessed. In Phase 3, 227 participants completed a revised 87-item questionnaire. Principal components analyses further reduced the number of items to 17 and suggested a two-factor structure (i.e., task and social cohesion dimensions). Finally, support for the factorial validity of the resultant questionnaire was provided through confirmatory factor analyses with an independent sample (n = 352) in Phase 4. The final version of the questionnaire contains 16 items that assess task and social cohesion in addition to 2 negatively worded spurious items. Specific issues related to assessing youth perceptions of cohesion are discussed and future research directions are suggested.
TL;DR: In this article, a mathematical model to describe microgalvanic corrosion was proposed and the negative difference effect (NDE) behavior was discussed based on Tafel type kinetics and explained in a consistent manner.
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01 Jan 2009TL;DR: In this paper, the authors present an argumentation as reasoned dialogue with questions and answers in dialogue and arguments to emotion, bias, and fallacies, and personal attack in argumentation.
Abstract: 1. Argument as reasoned dialogue 2. Questions and answers in dialogue 3. Criticism of irrelevance 4. Appeals to emotion 5. Valid arguments 6. Personal attack in argumentation 7. Appeals to authority 8. Inductive errors, bias, and fallacies 9. Natural language argumentation.
TL;DR: In this article, the main focus of the progress report is recent advances in physisorption materials exhibiting higher heats of adsorption and better hydrogen adorption at room temperature based on exploiting the Kubas model.
Abstract: Hydrogen adsorption and storage using solid-state materials is an area of much current research interest, and one of the major stumbling blocks in realizing the hydrogen economy. However, no material yet researched comes close to reaching the DOE 2015 targets of 9 wt% and 80 kg m ―3 at this time. To increase the physisorption capacities of these materials, the heats of adsorption must be increased to ∼20 kJ mol ―1 . This can be accomplished by optimizing the material structure, creating more active species on the surface, or improving the interaction of the surface with hydrogen. The main focus of this progress report are recent advances in physisorption materials exhibiting higher heats of adsorption and better hydrogen adsorption at room temperature based on exploiting the Kubas model for hydrogen binding: (η 2 -H 2 )―metal interaction. Both computational approaches and synthetic achievements will be discussed. Materials exploiting the Kubas interaction represent a median on the continuum between metal hydrides and physisorption materials, and are becoming increasingly important as researchers learn more about their applications to hydrogen storage problems.
TL;DR: Results indicate that site-specific differences in recruitment patterns are more important in determining early benthic community structure and coral recruitment than are differences among substrate material, and suggest that gabbro should be used preferentially over concrete or sandstone where it is feasible, but that granite may be a suitable alternativeWhere it is the dominant stone.
TL;DR: The results indicate that large artificial reefs can support diverse and abundant coral and fish communities, however, these communities differ structurally and functionally from those in natural habitats, and they should not be considered as replacements for natural coral andFish communities.
Abstract: Artificial reefs are often promoted as mitigating human impacts in coastal ecosystems and enhancing fisheries; however, evidence supporting their benefits is equivocal. Such structures must be compared with natural reefs in order to assess their performance, but past comparisons typically examined artificial structures that were too small, or were immature, relative to the natural reefs. We compared coral and fish communities on two large (>400,000 m3) and mature (>25 year) artificial reefs with six natural coral patches. Coral cover was higher on artificial reefs (50%) than in natural habitats (31%), but natural coral patches contained higher species richness (29 vs. 20) and coral diversity (H′ = 2.3 vs. 1.8). Multivariate analyses indicated strong differences between coral communities in natural and artificial habitats. Fish communities were sampled seasonally for 1 year. Multivariate fish communities differed significantly among habitat types in the summer and fall, but converged in the winter and spring. Univariate analysis indicated that species richness and abundance were stable throughout the year on natural coral patches but increased significantly in the summer on artificial reefs compared with the winter and spring, explaining the multivariate changes in community structure. The increased summer abundance on artificial reefs was mainly due to adult immigration. Piscivores were much more abundant in the fall than in the winter or spring on artificial reefs, but had low and stable abundance throughout the year in natural habitats. It is likely that the decreased winter and spring abundance of fish on the artificial reefs resulted from both predation and emigration. These results indicate that large artificial reefs can support diverse and abundant coral and fish communities. However, these communities differ structurally and functionally from those in natural habitats, and they should not be considered as replacements for natural coral and fish communities.
01 Jan 2009
TL;DR: This chapter explains the role of proof burdens and standards in argumentation, illustrates them using legal procedures, and surveys the history of research on computational models of these concepts, including an original computational model which aims to integrate the features of these prior systems.
Abstract: This chapter explains the role of proof burdens and standards in argumentation, illustrates them using legal procedures, and surveys the history of research on computational models of these concepts It also presents an original computational model which aims to integrate the features of these prior systems The ‘mainstream’ conception of argumentation in the field of artificial intelligence is monological and deductive [6] Argumentation is viewed as taking place against the background of an inconsistent knowledge base, where the knowledge base is a set of propositions represented in some formal logic Argumentation in this conception is a method for deducing warranted propositions from an inconsistent knowledge base Which statements are warranted depends on attack relations among the arguments [10] which can be constructed from the knowledge base The notions of proof standards and burden of proof become relevant only when argumentation is viewed as a dialogical process for making justified decisions The input to the process is an initial claim or issue The goal of the process is to clarify and decide the issues, and produce a justification of the decision which can withstand a critical evaluation by a particular audience The role of the audience could be played by the respondent or a neutral-third party, depending on the type of dialogue The output of this process consists of: 1) a set of claims, 2) the decision to accept or reject each claim, 3) a theory of the generalizations of the domain and the facts of the particular case, and 4) a proof justifying the decision of each issues, showing how the decision is supported by the theory Notice that a theory or knowledge-base is part of the output of argumentation dialogues, not, as in the deductive conception, its input This is because, as has been
TL;DR: This paper focuses on the shift of emphasis from social to private responsibilities and raises new questions about the forces of private enterprise and market-based partnerships and based on extensive analysis of policy documents and public sector reform initiatives.
Abstract: In light of public sector reforms in Canada and elsewhere, this paper focuses on the shift of emphasis from social to private responsibilities and raises new questions about the forces of private enterprise and market-based partnerships Under neoliberal governmental agendas, privatizing responsibility links to three main developments: the reconsideration of the relations of public and private; the mobilization of responsible citizenship; and the formation of a cultural mentality of rule that works alongside these developments The research for this article is based on extensive analysis of policy documents and public sector reform initiatives, as well as interviews with Canadian federal public service employees
TL;DR: In this article, a frequency-stepped WURST-QCPMG pulse sequence was used to obtain ultra-wideline NMR spectra of quadrupolar nuclei.
TL;DR: In this article, the authors examined the effect of compensation committee quality on the association between CEO cash compensation and accounting earnings and the moderating effects of growth opportunities and earnings status using a sample of 812 US firms.
Abstract: Manuscript Type: Empirical
Research Question/Issue: We examine the effect of compensation committee quality on the association between CEO cash compensation and accounting earnings and the moderating effects of growth opportunities and earnings status.
Research Findings/Insights: Using a sample of 812 US firms, we find that CEO cash compensation is more positively associated with accounting earnings when firms have high compensation committee quality. We also find that the positive effect of compensation committee quality on the association between CEO cash compensation and accounting earnings is less for high growth firms or loss-making firms.
Theoretical Implications: We contribute to the agency-based research on CEO compensation by: 1) directly examining the impact of compensation committee quality on the sensitivity of CEO cash compensation to accounting earnings; 2) examining whether the role of compensation committee quality varies across firms; and 3) developing a broader and richer measure of compensation committee quality.
Practical Implications: Our findings imply that shareholders and directors should be concerned about the composition of compensation committees as we find that compensation committee quality varies depending on compensation committee size and other characteristics of the committee members. Our findings also imply that for compensation committee members, there are greater challenges in monitoring CEO compensation contracts for firms with high growth or that incur losses. Further, our findings imply that even when all compensation committees are regulated to be fully independent, there are still quality differences among these independent compensation committees.
TL;DR: The results indicate that manual scanning is best for studies requiring an accurate account of temporal patterns in call frequency and for those involving birds with low vocalization rates.
Abstract: Although offering many benefits over manual recording and survey techniques for avian field studies, automated sound recording systems produce large datasets that must be carefully examined to locate sounds of interest. We compared two methods for locating target sounds in continuous sound recordings: (1) a manual method using computer software to provide a visual representation of the recording as a sound spectrogram and (2) an automated method using sound analysis software preprogrammed to identify specific target sounds. For both methods, we examined the time required to process a 24-h recording, scanning accuracy, and scanning comprehensiveness using four different target sounds of Pileated Woodpeckers {Dryocopus pileatus), Pale billed Woodpeckers {Campephilus guatemalensis), and putative Ivory-billed Woodpeckers {Campehilusprincipalis). We collected recordings from the bottomland forests of Florida and the Neotropical dry forests of Costa Rica, and compared manual versus automated cross-correlation scanning techniques. The automated scanning method required less time to process sound recordings, but made more false positive identifications and was less comprehensive than the manual method, identifying significantly fewer target sounds. Although the automated scanning method offers a fast and economic alternative to traditional manual efforts, our results indicate that manual scanning is best for studies requiring an accurate account of temporal patterns in call frequency and for those involving birds with low vocalization rates.
01 Jan 2009
TL;DR: In this paper, the scope of manufacturing changeability is outlined, the objects of change are defined, the change enablers are introduced and discussed and the change management strategy is highlighted.
Abstract: Manufacturing has been experiencing dynamically changing environment that presents industrialists and academics with formidable challenges to adapt to these changes effectively and economically while maintaining a high level of responsiveness, agility and competitiveness. Advances in manufacturing technologies, equipment, systems and organizational strategies are helping manufacturers meet these challenges. The ability to change and effectively manage this change is a fundamental pre-requisite for surviving and prospering in this turbulent environment. Changeability is presented as an umbrella concept that encompasses many change enablers at various levels of an industrial company throughout the life cycle of the manufacturing system. In this introduction, the scope of manufacturing changeability is outlined, the objects of change are defined, the change enablers are introduced and discussed and the change management strategy is highlighted.
TL;DR: In this article, a four factor three level Box-Benkhen design (BBD) was developed to describe the photocatalytic degradation of phenol in an aqueous media, and four process variables under consideration in BBD model included titanium dioxide (TiO2) catalyst size, TiO2 concentration, dissolved oxygen (DO) concentration and phenol concentration.
TL;DR: In this paper, the authors examined whether the relationship between future firm performance and chief executive officer (CEO) stock option grants is affected by the quality of the compensation committee, which was measured using six committee characteristics.
Abstract: This paper examines whether the relationship between future firm performance and chief executive officer (CEO) stock option grants is affected by the quality of the compensation committee. Compensation committee quality is measured using six committee characteristics – the proportion of directors appointed during the tenure of the incumbent CEO, the proportion of directors with at least ten years’ board service, the proportion of directors who are CEOs at other companies, the aggregate shareholding of directors on the compensation committee, the proportion of directors with three or more additional board seats, and compensation committee size. We find that future firm performance is more positively associated with stock option grants as compensation committee quality increases.
TL;DR: Possible changes in food-web structure, evaluated through stable nitrogen isotopes (delta15N), may be influencing interpretations of contaminant trends in lake trout and are hypothesized to be partially responsible for the observed decrease in concentrations of BDEs 28, 47, 99, 100, 153, and 154 between 1998 and 2004.
Abstract: Concentrations of non-polybrominated diphenyl ether (PBDE) brominated (hexabromocyclododecane [HBCD], 1,2-bis[2,4,6-tribromophenoxy]ethane [BTBPE], and pentabromoethylbenzene [PEB]) and chlorinated (Dechlorane Plus [DP] as well as short- and medium-chain chlorinated paraffins [SCCP and MCCP, respectively]) flame retardants were evaluated in archived Lake Ontario, Canada, lake trout (Salvelinus namaycush) samples collected between 1979 and 2004. Polybrominated diphenyl ethers also were analyzed to provide a point of reference for comparison to previous studies. Concentrations of the dominant PBDE congeners (BDEs 28, 47, 99, 100, 153, and 154) increased significantly from 1979 until the mid-1990s, then either leveled off or decreased significantly between 1998 and 2004, a result that corresponds to those of previous studies. In contrast, BDE 209 increased approximately fourfold between 1998 and 2004. The temporal trends of the non-PBDE flame retardants varied, with sum (Σ) HBCD and DP showing significant overall decreases; BTBPE, ΣSCP, and ΣMCP showing parabolic trends; and PEB showing no overall change during the study period. Because many of the non-PBDE chemicals may be used as replacements for penta- and octa-BDE mixtures, these results will provide a baseline to evaluate future usage patterns. Possible changes in food-web structure, evaluated through stable nitrogen isotopes (δ15N), may be influencing our interpretations of contaminant trends in lake trout and are hypothesized to be partially responsible for the observed decrease in concentrations of BDEs 28, 47, 99, 100, 153, and 154 between 1998 and 2004. Retrospective analyses evaluating temporal trends in stable isotope values at the base of the food web, however, are recommended to test this hypothesis further.
TL;DR: This study investigates patterns of macroevolutionary processes, such as the emergence of species in a simulated ecosystem, and proposes a general framework for the study of specific ecological problems such as invasive species and species diversity patterns.
Abstract: We present an individual-based predator-prey model with, for the first time, each agent behavior being modeled by a fuzzy cognitive map (FCM), allowing the evolution of the agent behavior through the epochs of the simulation. The FCM enables the agent to evaluate its environment (e.g., distance to predator or prey, distance to potential breeding partner, distance to food, energy level) and its internal states (e.g., fear, hunger, curiosity), and to choose several possible actions such as evasion, eating, or breeding. The FCM of each individual is unique and is the result of the evolutionary process. The notion of species is also implemented in such a way that species emerge from the evolving population of agents. To our knowledge, our system is the only one that allows the modeling of links between behavior patterns and speciation. The simulation produces a lot of data, including number of individuals, level of energy by individual, choice of action, age of the individuals, and average FCM associated with each species. This study investigates patterns of macroevolutionary processes, such as the emergence of species in a simulated ecosystem, and proposes a general framework for the study of specific ecological problems such as invasive species and species diversity patterns. We present promising results showing coherent behaviors of the whole simulation with the emergence of strong correlation patterns also observed in existing ecosystems.
TL;DR: Results show that effective emotional processing was simultaneously associated with steady improvement according to the model as well as increased emotional range and good events were also shown to have progressively shortened emotional collapses, whereas the opposite was true for poor in-session events.
Abstract: The study of dynamic and nonlinear change has been a valuable development in psychotherapy process research. However, little advancement has been made in describing how moment-by-moment affective processes contribute to larger units of change. The purpose of this study was to examine observable moment-by-moment sequences in emotional processing as they occurred within productive sessions of experiential therapy. This article further tested A. Pascual-Leone and L. S. Greenberg's (2007) model of emotional processing through a reanalysis of their data sample of 34 sessions in which clients presented with global distress: 17 that ended in poor in-session events and 17 that ended in good in-session events. Current analyses used univariate and bootstrapping statistical methods to examine how dynamic temporal patterns in clients' emotion accumulated moment-by-moment to produce in-session gains in emotional processing. Results show that effective emotional processing was simultaneously associated with steady improvement according to the model as well as increased emotional range. Consequentially, good events were shown to occur in a 2-steps-forward, 1-step-back fashion. Finally, good events were also shown to have progressively shortened emotional collapses, whereas the opposite was true for poor in-session events.