Volatile chemicals from leaf litter are associated with invasiveness of a neotropical weed in Asia

Some invasive plant species appear to strongly suppress neighbors in their nonnative ranges but much less so in their native range. We found that in the field in its native range in Mexico, the presence of Ageratina adenophora, an aggressive Neotropical invader, was correlated with higher plant species richness than found in surrounding plant communities where this species was absent, suggesting facilitation. However, in two nonnative ranges, China and India, A. adenophora canopies were correlated with much lower species richness than the surrounding communities, suggesting inhibition. Volatile organic compound (VOC) signals may contribute to this striking biogeographical difference and the invasive success of A. adenophora. In controlled experiments volatiles from A. adenophora litter caused higher mortality of species native to India and China, but not of species native to Mexico. The effects of A. adenophora VOCs on seedling germination and growth did not differ between species from the native range and species from the nonnative ranges of the invader. Litter from A. adenophora plants from nonnative populations also produced VOCs that differed quantitatively in the concentrations of some chemicals than litter from native populations, but there were no chemicals unique to one region. Biogeographic differences in the concentrations of some volatile compounds between ranges suggest that A. adenophora may be experiencing selection on biochemical composition in its nonnative ranges.     

Beliefs about ‘improvability’ of career‐relevant skills: relevance to job/task analysis,competency modelling,and learning orientation

Based on data obtained from three samples of participants from both a work organization and a college setting, this paper addressed two major research objectives relevant to organizational behavior and applied psychology. First, we wanted to explore the nature of implicit theory of skill malleability in more detail than has been done before. This was done by drawing on KSAO dimensions from the task/job analysis literature, and examining linkages among: (a) task/job analysis; (b) implicit theories; and (c) competency modelling (an area in which there has been little empirical research). The studies found multiple factors of beliefs about KSAO improvability and showed a clear ordering of improvability beliefs (from most to least improvable) that follow predictions made in the Iceberg model of competencies. The present studies also found relationships between perceptions of KSAO importance and KSAO improvability, as well as evidence that this relationship is stronger for people who have been in a role/job longer, having had greater opportunity to observe critical KSAOs improve over time. A second major objective of the research was to explore improvability beliefs within a nomological network that would help to further establish the construct validity of the beliefs within the learning/development area. Using structural modelling, the improvability beliefs were tied to learning‐oriented concepts including self‐efficacy for learning and development, tendency to compare oneself to others when learning, as well as learning‐oriented attitudes and behaviors. The potential practical value of improvability beliefs is discussed, as are suggestions for future research. Copyright © 2003 John Wiley & Sons, Ltd.     

Computer-based training for food services workers at a hospital

INTRODUCTION: Interactive computer-based safety instruction (CBI) was given to 73 workers in the food services department of an urban hospital. RESULTS: Post-test accuracy (95%) improved significantly (p < or = 0.0001) from the pre-test (74.5 %), d = 1.09. Generalization was confirmed by increased accuracy in answering questions, posed on-the-job, that required application of knowledge to the work setting (from 46% to 79%; p < 0.0001). Problematic kitchen conditions such as puddles increased slightly after training, but adjustment for increasing production/workload revealed an overall post-training decline in problems from 0.58 to 0.32 (p = 0.0001, d = 0.89). Work practice improvement was seen in 79% of workers (p < 0.0001, d = 1.00). Effect sizes (d) of knowledge, location, and work practice improvements are large and demonstrate that the benefits of CBI extend to the workplace floor. Further, the decrease between knowledge and behavior change (d = 0.09-0.2) is less than reported following other forms of training.     

A longitudinal analysis of the impact of workplace empowerment on work satisfaction

A longitudinal predictive design was used to test a model linking changes in structural and psychological empowerment to changes in job satisfaction. Structural equation modeling analyses revealed a good fit of the data from 185 randomly selected staff nurses to the hypothesized model. Changes in perceived structural empowerment had direct effects on changes in psychological empowerment and job satisfaction. Changes in psychological empowerment did not explain additional variance in job satisfaction beyond that explained by structural empowerment. The results suggest that fostering environments that enhance perceptions of empowerment can have enduring positive effects on employees. Copyright © 2004 John Wiley & Sons, Ltd.     

‘A system that works for the sea’? Exploring Stakeholder Engagement in Marine Spatial Planning

This paper aims to contribute to the current debate on Marine Spatial Planning (MSP) by exploring the issue of stakeholder engagement. MSP is an emergent policy field that is subject to an increasing body of research, yet the role, scope and nature of participatory engagement within the process remains a neglected topic. This paper briefly reviews the nature of the ‘marine problem’, to which MSP is seen to be the response and describes the emergence of MSP policy in the UK with specific emphasis on participatory aspects. Drawing on the experience of terrestrial planning it discusses the potential benefits of stakeholder engagement in MSP and highlights some of the key issues that need to be taken into account when shaping stakeholder input into the process. It then goes on to describe the findings from a series of interviews with key stakeholders in the Irish Sea Region, which suggest that we need to develop a more critical and deeper understanding of how various interests frame the ‘marine problem’, and how they see their role in shaping the form of the MSP process. This highlights the importance of encouraging stakeholder involvement in MSP, the need to develop a shared vision of a ‘sea interest’. Priorities are then set for research to support this important policy agenda.     

Copper toxicity to Lemna minor modelled using humic acid as a surrogate for the plant root

Humic acids are chemically analogous to plant root cell walls in that their surface sites are principally comprised of carboxylic and phenolic acids which bind both metals and protons. Based on this analogy, we developed a biotic-ligand type of model to predict Cu toxicity to Lemna minor, using particulate humic acid (HA(part)) of the Windermere Humic Aqueous Model (WHAM), and 7d static-renewal exposures with five surface waters and one nutrient media which varied in DOC (1-10 mg L(-1)), pH (6.9-8.7), and water hardness (35-236 mg equivalent CaCO(3)L(-1)). Although the range of waters tested resulted in a 36-fold variation in 50% inhibitory concentration (IC50) values, the calculated concentration of Cu bound to HA(part) using this framework was highly correlated with pooled percent net root elongation (%NRE) (R(2)=0.95). Ten and fifty percent IC values based on [Cu-HA(part)] were additionally within a factor of ±1.5 and ±1.4, respectively, inclusive of 95% confidence limits. This model construct, which defines the free metal ion and the first hydrolysis product (but not metal carbonate complexes) as being bioavailable, provides an alternative means of defining the binding surface in bioavailability models, whereby a heterogeneous mixture of ligands collectively influence root-metal sorption and toxicity.     

Characterization and identification of trends in average ambient ozone and fine particulate matter levels through trajectory cluster analysis in eastern Canada

In many locations in Eastern Canada, ambient levels of fine particulate matter (PM,25) and surface ozone (O3) depend on airflow direction and synoptic scale meteorological conditions. In this study, a cluster analysis was performed on 10 yr (1994-2003) of back-trajectory data for 11 locations in Eastern Canada, resulting in the identification of 10 unique back-trajectory clusters (or airflows) for each location. The airflows were then used to characterize and identify spatial and temporal trends in the daily maximum 8-hr average O3 (dmax 8-hr O3) and the daily average PM2.5 levels. Results showed that airflows from the southwest passing over Michigan and Southern Ontario were associated, on average, with the highest O3 levels at most locations in Eastern Canada. For PM2.5, the highest levels occurred with airflows from the Eastern Ohio River Valley. At major urban locations in Ontario and Quebec, the warm season mean (May to September) dmax 8-hr O3 and the annual mean PM2.5 were, on average, 12 parts per billion and 7.6 microg/m3 higher, respectively, than airflows from the north. Elevated levels of O3 and PM2.5 also occurred under light airflows, and, on average, the levels under light airflows were higher than their nonlight counterparts. At several locations in Canada, including Toronto, Montreal, Quebec City, and Kejimkujik, the annual warm season mean dmax 8-hr O3 experienced a statistically significant (95% confidence) increasing trend over the 10-yr period. When airflow direction was considered, a number of locations experienced statistically significant upward trends in O3 for airflow from the north and northwest. Several locations also showed significant upward trends associated with airflow from the southwest passing over Michigan and Southwestern Ontario. Although there are no statistically significant downward trends, airflows from the southwest have shown a reduction in O3 levels in Southwestern Ontario in more recent years.