Sensitivity of marine microalgae to copper: the effect of biotic factors on copper adsorption and toxicity

Microalgae are sensitive indicators of environmental change and, as the basis of most freshwater and marine ecosystems, are widely used in the assessment of risk and development of environmental regulations for metals. However, interspecies differences in sensitivity to metals are not well understood. The relationship between metal-algal cell binding and copper sensitivity of marine microalgae was investigated using a series of 72-h growth-rate inhibition bioassays and short-term (1-h) uptake studies. A range of marine algae from different taxonomic groups were screened to determine whether copper adsorption to the cell membrane was influenced by biotic factors, such as the ultrastructure of cell walls and cell size. Minutocellus polymorphus was the most sensitive species to copper and Dunaliella tertiolecta the least sensitive, with 72-h IC50 values (concentration to inhibit growth-rate by 50%) of 0.6 and 530 microg Cu/L, respectively. Copper solution-cell partition coefficients at equilibrium (K(d)) were calculated for six species of algae on a per cell and surface area basis. The largest and smallest cells had the lowest and highest K(d) values, respectively (on a surface area basis), with a general (non-linear) trend of decreasing K(d) with increasing cell surface area (p=0.026), however, no relationship was found between K(d) and copper sensitivity, nor cell size and copper sensitivity. Interspecies differences in copper sensitivity were not related to cell size, cell wall type, taxonomic group or K(d) values. The differences in sensitivity may be due to differences in uptake rates across the plasma membrane, in internal binding mechanisms and/or detoxification mechanisms between the different microalgal species.     

Conceptualizing ‘the Urban’ Through the Lens of Durban,South Africa

Contemporary urban theory raises many questions about how ‘the urban’ is being conceptualized in a fast changing world that is approaching an urban epoch. Evolving debates about what it means to be urban, including the similarities and differences between so-called northern and southern cities, the future of cities, the way to manage and sustain cities, and cities’ relationships to the new Urban Agenda and the Sustainable Development Goals, reveal the need for urban theory that can explain and provide insights into contemporary urban governance, processes, and outcomes. This special issue uses Durban as a lens to provide insight into the changing nature of cities in the Global South and Africa in particular, which encapsulate and reflect both formality and informality; tradition and modernity; uneven and unequal growth and social transformation; environmental crises and ‘resilience and sustainability’. This paper reflects on the dominant processes shaping the development of the city, revealing the challenges, tensions, and opportunities that emerge as the city assembles new ways of being urban, through the rationalities, knowledge, experiences, practices and actions of the state, citizens, and the private sector.     

Les défis diagnostiques posés par l'évaluation clinique des allégations de sévices sexuels concernant des enfants.

Knowledge and expertise acquired in clinical and empirical psychology are increasingly requested by social and judicial authorities when confronted with allegations of sexual abuse on children. In view of this increased demand, various evaluation methods and techniques have been developed, some for which the measurement value and conceptual relevance have not been demonstrated. The article brings us up to date on evaluation methods pertaining to allegations of sexual abuse on children and suggests a practical framework that takes into account recognized clinical principles and recent research results in this field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of instruction and verbalization in improving performance on complex search tasks

This paper examines methods of improving human search performance on a diagnostic task where it does not help to provide computer suggestions about the next enquiry to make. In three experiments it was found (a) that verbal instruction in optimal procedures was ineffective in changing actual performance, although it changed answers to verbal tests of knowledge; (b) that requiring people to say aloud the reasons for each action was ineffective in changing either performance or verbal tests of knowledge; but if people were given both verbal instructions and the requirement to justify each action aloud, performance was improved; (c) this successful training method changed performance not merely on the specific task that was trained, but also on a superficially different search task in which the same general procedures were optimal. These findings suggest that human decision processes change if key information is temporarily activated at the time it is needed, but not if it is merely learned at an irrelevant time. Such a process also explains the beneficial effect of interfaces that provide explanation or the results of inference at key points in the task.     

The structure of expressed emotion: A three-construct representation.

Confirmatory factor analysis was used to explore a 3-factor model of expressed emotion (Criticism, Emotional Overinvolvement, and Positivity) in a sample of 104 outpatients with agoraphobia or obsessive-compulsive disorder and 104 relatives of these patients. Multiple methods of measurement included the Camberwell Family Interview, observation of verbal and nonverbal behaviors during patient–relative problem-solving interactions, and ratings of relatives' behavior made by patients and by relatives. The convergent validity of the 3 individual constructs was demonstrated through single-factor models fitted to Criticism, Positivity, and Emotional Overinvolvement measures. A 3-factor model was then estimated and determined to provide adequate fit to the data, thus demonstrating the distinctiveness of the constructs. Criticism and Positivity were strongly and negatively correlated, whereas Emotional Overinvolvement bore little relationship to the other 2 factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expressed emotion and behavior therapy outcome: A prospective study with obsessive–compulsive and agoraphobic outpatients.

The relationship of expressed emotion (EE) to behavior therapy outcome for obsessive-compulsive disorder (n?=?60) and panic disorder with agoraphobia (n&=?41) was investigated. Relatives' emotional overinvolvement and hostility predicted higher rates of treatment dropout. Higher hostility, as assessed by the Camberwell Family Interview (CFI), was related to poorer outcome for target ratings and for the Social Adjustment Scale; higher perceived criticism was also predictive of worse response on target ratings. In contrast, nonhostile criticism on the CFI was associated with better outcome on the behavioral avoidance test. In general, the relationship of EE to outcome was not moderated by type of relative, diagnosis, amount of contact with the relative, or use of psychotropic medication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nephrotoxic Potential of Putative 3,5-Dichloroaniline (3,5-DCA) Metabolites and Biotransformation of 3,5-DCA in Isolated Kidney Cells from Fischer 344 Rats

The current study was designed to explore the in vitro nephrotoxic potential of four 3,5-dichloroaniline (3,5-DCA) metabolites (3,5-dichloroacetanilide, 3,5-DCAA; 3,5-dichlorophenylhydroxylamine, 3,5-DCPHA; 2-amino-4,6-dichlorophenol, 2-A-4,6-DCP; 3,5-dichloronitrobenzene, 3,5-DCNB) and to determine the renal metabolism of 3,5-DCA in vitro. In cytotoxicity testing, isolated kidney cells (IKC) from male Fischer 344 rats (~4 million/mL, 3 mL) were exposed to a metabolite (0–1.5 mM; up to 90 min) or vehicle. Of these metabolites, 3,5-DCPHA was the most potent nephrotoxicant, with 3,5-DCNB intermediate in nephrotoxic potential. 2-A-4,6-DCP and 3,5-DCAA were not cytotoxic. In separate experiments, 3,5-DCNB cytotoxicity was reduced by pretreating IKC with antioxidants and cytochrome P450, flavin monooxygenase and peroxidase inhibitors, while 3,5-DCPHA cytotoxicity was attenuated by two nucleophilic antioxidants (glutathione and N-acetyl-L-cysteine). Incubation of IKC with 3,5-DCA (0.5–1.0 mM, 90 min) produced only 3,5-DCAA and 3,5-DCNB as detectable metabolites. These data suggest that 3,5-DCNB and 3,5-DCPHA are potential nephrotoxic metabolites and may contribute to 3,5-DCA induced nephrotoxicity in vivo. In addition, the kidney can bioactivate 3,5-DCNB to toxic metabolites, and 3,5-DCPHA appears to generate reactive metabolites to contribute to 3,5-DCA nephrotoxicity. In vitro, N-oxidation of 3,5-DCA appears to be the primary mechanism of bioactivation of 3,5-DCA to nephrotoxic metabolites.     

The influence of color on student emotion,heart rate,and performance in learning environments

In this study, six colors (vivid red, vivid blue, vivid yellow, pale red, pale blue, and pale yellow^?) were manipulated in a simulated study environment to determine their effects on university students' learning performance, emotions, and heart rate. It was hypothesized that learning, physiological and emotional states would be affected by different colors in private study spaces. A total of 24 undergraduate and postgraduate students participated in this study. The dependent variables were reading task performance, emotional responses, and changes in heart rate. The results showed that, although participants assessed the situation as relaxed, calm, and pleasant in the pale color conditions, reading scores were significantly higher in the vivid color conditions. Heart rates were significantly affected by hue; they increased in the red and yellow conditions. In addition, the results suggested that, regardless of the degree of whiteness, the hue had a significant impact on participants' emotions; blue increased relaxation and calmness feelings of participants compared to the other colors. Implications of these findings and suggestions for further research are discussed. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 196–205, 2016     

Metal Injection Molding of PH 13-8 Mo Stainless Steel

Powder metal injection molding has been used for fabrication of near net shape parts from a number of ferrous alloys including carbonyl steels and stainless steels in the 3XX series and PH 17-4. However, no work has been performed to-date on the metal injection molding of PH 13-8 Mo. Because of a special application, this alloy was injection molded and debound using two different methods. Mechanical properties and micro structural analysis of PH 13-8 Mo parts formed using metal injection molding are presented. Differences in mechanical properties, heat treatment response, and microstructure were observed between the different methods used to make the parts.     

Status of Quality Management practices in manufacturing SMEs: a comparative study between Australia and the UK

This study is aimed to assess and compare the status of quality management (QM) practices in the manufacturing small and medium-sized enterprises (SMEs) in Australia and the UK, and to develop better insights into the use of and benefits from such QM practices. Furthermore, the intention was to identify the trends for adoption of advanced QM practices such as Lean and Six Sigma. A similar survey instrument was designed and tested in the two countries and data were analysed using SPSS and excel worksheet. The findings confirm that the adoption of Six Sigma is quite slow in Australian and the UK SMEs. ISO 9000 is the most popular QM initiatives in SMEs followed by the recent trend to implement Lean for streamlining business processes. Leadership is critical to the success of any QM practices such as Lean and Six Sigma. Networking with government bodies and academic institutions, and fact-based decision-making emerged as the two new critical success factors for implementing QM in SMEs. Significant improvement in performance metrics was observed in the UK SMEs after implementation of quality initiatives, though similar result was not replicated in the Australian sample.