Joana Almeida

Photodynamic inactivation of multidrug-resistant bacteria in hospital wastewaters: influence of residual antibiotics

One environmental concern related to hospital effluents is discharge of them without preliminary treatment. Antimicrobial photodynamic inactivation (PDI) may represent an alternative to the traditional expensive, unsafe and not always effective disinfection methods. The main goal of this work was to assess the efficiency of PDI on clinical multidrug-resistant (MDR) bacteria in hospital wastewaters in order to evaluate its potential use in treating hospital effluents. The efficiency of PDI was assessed using a cationic porphyrin as the photosensitizer (PS), four MDR bacteria either in phosphate buffered saline or in filtrated hospital wastewaters. The synergistic effect of PDI and antibiotics (ampicillin and chloramphenicol) was also evaluated, as well as the effect of the surfactant sodium dodecyl sulfate (SDS). The results show the efficient inactivation of MDR bacteria in PBS (reduction of 6-8 log after 270 min of irradiation at 40 W m(-2) with 5.0 μM of PS). In wastewater, the inactivation of the four MDR bacteria was again efficient and the decrease in bacterial survival starts even sooner. A faster decrease in bacterial survival occurred when PDI was combined with the addition of antibiotics, at sub-inhibitory and inhibitory concentrations, but the SDS did not affect the PDI efficiency. It can be concluded that PDI has potential to be an effective alternative for the inactivation of MDR bacteria in hospital wastewaters and that the presence of antibiotics may enhance its effectiveness.

Enhancing the intercultural effectiveness of exchange programmes: formal and non-formal educational interventions

Abstract This paper examines how the addition of intercultural interventions carried out throughout European credit-bearing exchange programmes can enhance sojourners’ development of intercultural competencies, and it explores how both formal and non-formal pedagogical interventions may be designed and implemented. Such interventions were conducted at a Portuguese university with 31 sojourners throughout one academic year, and their impact was assessed using a mixed methods research design. Sojourners included incoming students of the exchange programmes Campus Europae and Erasmus, as well as highly skilled immigrants. Findings confirm the positive impact of interventions on the development of intercultural competencies and, in turn, their contribution to internationalisation efforts. Implications for further research suggest a need to increase interventions and to develop a systematic approach for fostering intercultural competencies throughout the study abroad cycle.

Internationalization at home: time for review and development?

ABSTRACT Internationalization is a key contemporary debate within Higher Education (HE). Many universities worldwide proclaim their ‘international’ status, citing quantitative indicators, particularly international student and staff recruitment and outbound student mobility data to illustrate this. In this paper, we focus on the non-mobile majority of the academic community. We foreground internationalization at home (IaH) and the underlying social, academic and intercultural learning benefits of an internationalized university experience. We explore how IaH is understood and operationalized in two universities in the United Kingdom and Portugal via a multiple case study. Qualitative data from 12 stakeholder interviews are analysed, generating five themes about operational understandings and practices of IaH. Findings identify relevant explanatory factors that may assist other institutions to understand, enact and communicate about IaH. We highlight the need for further empirical research to provide insights into how this key dimension of internationalization is being operationalized across other European HE institutions.

Major, minor, trace and rare earth elements in sediments of the Bijagós archipelago, Guinea-Bissau

Sixty sediment samples from four sites in the Bijagós archipelago were characterized for fine fraction, loss on ignition, major, minor and trace elemental composition (Al, Fe, Ca, Mg, Ti, P, Zr, Mn, Cr, Sr, Ba, B, V, Li, Zn, Ni, Pb, As, Co, U, Cu, Cs and Cd), and the elements of the La-Lu series. Element concentrations were largely explained by the Al content and the proportion of fine fraction content, with the exception of Ca and Sr. Sediments showed enhanced Ti, U, Cr, As and Cd concentrations with respect to estimated upper crust values, most likely mirroring a regional signature. Rare earth elements were in deficit relatively to the North American Shale Composite (NASC), mainly in coarser material. No pronounced Ce-anomaly was observed, while Eu-anomalies were positive in most analyzed sediments.

Simultaneous removal of trace elements from contaminated waters by living Ulva lactuca

This work shows the capabilities of living seaweed, Ulva lactuca, to remove As, Cd, Pb, Cu, Cr, Hg, Mn and Ni from contaminated waters. Experiments were performed with three algal doses (1.5, 3.0 and 6.0 g L-1, FW), two ionic strengths (salinity 15 and 35), and trace element concentrations corresponding to the maximum allowed values in wastewaters. The highest removals were obtained with the algal dose of 6 g L-1, with efficiencies varying between 48% for As and 98% for Hg, after 24 to 72 h. Salinity showed no effect on the removal efficiency. Overall, Elovich model was the best in describing the kinetics of the process, except for Hg, where pseudo-second-order model performed better. The use of extractions with EDTA (0.001, 0.01 to 0.1 mol L-1) has clarified that most of the Hg (≈98%) and Cr (≈80%) crossed the macroalgae walls, while Ni, Cd and As were retained at the surface (between 60 and 80%). These results support the hypothesis that macroalgae-based technologies may be a viable, cost-effective, and greener option to reduce the rejection of priority hazardous substances in contaminated waters.