DNA barcoding to confirm morphological traits and determine relative abundance of burrowing mayfly species in western Lake Erie

Burrowing mayfly species of the genus Hexagenia are well known indicators of environmental health in lakes and rivers. Two species, H. limbata and H. rigida, are indistinguishable as nymphs and as adult females. Our objectives were to develop a genetic technique to distinguish between the two species and identify morphological features that separate cryptic nymphs and adult females. Fifty nymphs were collected before emergence from 10 sites throughout the western basin of Lake Erie in 2004 and 2005. Using known specimens of adult aerial male H. limbata and H. rigida, we used the mitochondrial cytochrome c oxidase subunit 1 (COI) gene to identify a 16 base pair (bp) difference between species. DNA sequencing confirmed correct species identification based on differences in abdominal pigmentation patterns on adult female imagos in 19 of 20 cases; the lone exception was a female with very faint pigmentation. Pigmentation patterns between species were consistent on nymphs, subimagos and imagos of both sexes. Populations of both species are panmictic across the western basin of Lake Erie, but H. limbata is the numerically dominant species, representing 70 to 100% of nymphs at sites in both years. A separate lineage of H limbata was discovered in the samples. The ability to distinguish nymphs of the two species will aid in developing more sensitive ecosystem indicators.     

Extracting local mechanical properties of steel bars by means of instrumented flat indentation

The evaluation of local mechanical properties of metal parts can be used for the prediction of forming and cutting forces during the following working stages. In order to show the feasibility of using indentation tests for work-piece characterization, C40 steel disks were cut from an extruded bar and machined by facing operation under different conditions. Indentation tests were carried out with 1 mm and 2 mm diameter indenters made of tungsten carbide; yield strength and indentation pressure values were extracted along the diameter of each disk. For the first time, indentation results were used to extract local mechanical properties of steel bars as a function of their process conditions: it was observed that small pins gave information on the effect of the machining process whereas large pins were more suitable to evaluate work-piece bulk properties.     

The effects of hot isostatic pressing (HIP) and solubilization heat treatment on the density,mechanical properties,and microstructure of austenitic stainless steel parts produced by selective laser melting (SLM)

Despite ongoing optimization, selective laser melting (SLM) technology still cannot guarantee the production of completely defect-free components. This wor     

From outpost to outback: project career paths in Australia

With the growth in project management as a form of work organisation in many sectors of the economy has come the significant rise in the number of project managers and project team members. This change in work organisation brings issues in forging career paths and determining career support in work situations that are often dynamic, short lived and intense. In the relatively small but substantially robust Australian economy, a unique labour market and the tyranny of distance bring their own difficulties. Innovative and collaborative project structures and increasing prevalence of contract work provide both challenges and opportunities for new career pathways in many industries. A growing percentage of Australia's workforce is employed in project-based or project-oriented organisations, leading to the claim that Australia is a project-based economy. This provided a context for our research into the career paths and the issues of career management for project managers working in a project based economy. Using in-depth interviews with project managers from three industry areas we found generational and gender differences in experiences of work, workplace support and mentoring for career development. For a continued strong performance in this economy, organisations that employ project personnel will need to consider how they will ensure the supply of high quality project professionals into the future.     

Vibration-based crack prediction on a beam model using hybrid butterfly optimization algorithm with artificial neural network

Vibration-based damage detection methods have become widely used because of their advantages over traditional methods. This paper presents a new approach to identify the crack depth in steel beam structures based on vibration analysis using the Finite Element Method (FEM) and Artificial Neural Network (ANN) combined with Butterfly Optimization Algorithm (BOA). ANN is quite successful in such identification issues, but it has some limitations, such as reduction of error after system training is complete, which means the output does not provide optimal results. This paper improves ANN training after introducing BOA as a hybrid model (BOA-ANN). Natural frequencies are used as input parameters and crack depth as output. The data are collected from improved FEM using simulation tools (ABAQUS) based on different crack depths and locations as the first stage. Next, data are collected from experimental analysis of cracked beams based on different crack depths and locations to test the reliability of the presented technique. The proposed approach, compared to other methods, can predict crack depth with improved accuracy.     

Assessing the aggregation behaviour of iron oxide nanoparticles under relevant environmental conditions using a multi-method approach

Iron nanoparticles are becoming increasingly popular for the treatment of contaminated soil and groundwater; however, their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Assessing their stability under environmental conditions is crucial for determining their environmental fate. A multi-method approach (including different size-measurement techniques and the DLVO theory) was used to thoroughly characterise the behaviour of iron oxide nanoparticles (Fe₂O₃NPs) under environmentally relevant conditions. Although recent studies have demonstrated the importance of using a multi-method approach when characterising nanoparticles, the majority of current studies continue to use a single-method approach.Under some soil conditions (i.e. pH 7, 10 mM NaCl and 2 mM CaCl₂) and increasing particle concentration, Fe₂O₃NPs underwent extensive aggregation to form large aggregates (>1 μm). Coating the nanoparticles with dissolved organic matter (DOM) was investigated as an alternative “green” solution to overcoming the aggregation issue instead of using the more commonly proposed polyelectrolytes. At high concentrations, DOM effectively covered the surface of the Fe₂O₃NPs, thereby conferring negative surface charge on the particles across a wide range of pH values. This provided electrostatic stabilisation and considerably reduced the particle aggregation effect. DOM-coated Fe₂O₃NPs also proved to be more stable under high ionic strength conditions. The presence of CaCl₂, however, even at low concentrations, induced the aggregation of DOM-coated Fe₂O₃NPs, mainly via charge neutralisation and bridging. This has significant implications in regards to the reactivity and fate of these materials in the environment.     

Immune parameters in female workers exposed to urban pollutants

Urban outside workers, such as traffic police, are daily exposed to air pollutants and psychosocial stressors: for these workers, the working environment corresponds to the living environment of the general population. Studies in the literature have shown that immune parameters could be affected by chronic exposure to various chemical pollutants. The aim of this study is to evaluate whether occupational exposure to urban pollutants can cause alterations in NK, IL-2, IFN-gamma and C3 plasma levels in female traffic police compared to a control group. After excluding subjects with the principal confounding factors, 86 female traffic police and 87 controls were matched by age, years of police work and habitual alcohol consumption. The distribution of NK values in female traffic police and controls was significantly different (p=0.000); NK values above the upper limit of the normal laboratory range were observed in 23 female traffic police and in 2 controls (p=0.000). IL-2 mean levels were higher in traffic police compared to controls, but the difference was not significant. The mean and the distribution of IFN-gamma values in female traffic police and controls were not different. C3 mean levels were higher in female traffic police versus controls, but the difference was not significant. Considering that the subjects with the principal confounding factors were excluded from the study and that female traffic police and controls were matched by the above-mentioned variables, our results suggest that chronic occupational exposure to low doses of chemical stressors, which may interact with and add to psychosocial ones, can affect both innate and adaptative immunity.     

How to get residents/owners in housing cooperatives to agree on sustainable renovation

What factors increase the chance that residents/owners in housing cooperatives agree on sustainable energy efficient renovation? Based on 30 qualitative interviews with professional advisors in cooperative housing associations and chairman/board and residents in three chosen case studies, an analysis of opportunities and barriers for making a common decision on renovation is performed. Success criteria and barriers are found on the societal level as well as on the organizational/individual level. The barriers and success criteria identified on the societal level are: knowledge level on energy-efficient renovation among relevant actors, owner structure of the housing cooperative, and existing regulations and incentives. On the organizational and individual level, the following categories influencing renovation processes were identified: the time frame and organization of the process, understanding the residents` needs, economy, the information given, and the existence of available exemplary projects and role models. Based on the results of the study, ten guidelines that contribute to more successful decision making processes and increase the chances of sustainable energy efficient renovation in housing cooperatives are presented.     

Long-term effects of sexual victimization in childhood: An attributional approach.

Explored the relation between childhood sexual victimization experience and adult functioning in 103 women (aged 18–56 yrs) who were victimized as children or adolescents and 88 women (aged 18–57 yrs) who were not victimized, who served as controls. Members of both groups completed a questionnaire about their present social, psychological, and sexual functioning; measures included the Beck Depression Inventory, SCL-90, Texas Social Behavior Inventory, Attributional Style Questionnaire, Rotter's Internal–External Locus of Control Scale, and the Marlowe-Crowne Social Desirability Scale. Victimized Ss differed significantly from nonvictims on measures of (a) childhood family and social experiences; (b) adult attributional style; and (c) levels of depression, psychological distress, self-esteem, and sexual problems. Results suggest that the sexually victimized Ss' adult functioning was related most strongly to their attributional style for bad events. Perception of the victimization experience and quality of social support were important factors related to adult functioning. Possible implications for treating women who are experiencing problems related to childhood sexual victimization experiences are discussed. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)