A key to the families and genera of freshwater fishes of Tanzania

The purpose of this key is to facilitate rapid and accurate identification, in the field, for fisheries workers. It is therefore based as much as possible on external characters only and an attempt has been made to keep it simple and straight forward. The only real difficulty arises in clearly demarcating the numerous cichlid genera of the great lakes, despite the fact that these have been treated in separate sections for each lake. Moreover, it hasn't been possible to revise the key to the lake Nyasa genera (taken from Jackson, 1961) to any significant extent, my experience with L. Nyasa fishes being limited; also, a few new genera have been or are still in the process of being published and I unfortunately haven't had access to these papers. A short bibliography is appended covering the major publications relevant to the systematics of Tanzania freshwater fishes and the sources from which these keys have been drawn up.

Industrialization as a key element of sustainable product-service solutions

Product-service systems are seen by many authors to offer potential for significant sustainability benefit. Manufacturing companies are said to be essential to such a change through their influence over product performance and over the use and end-of-life stages. Yet linking these stages such that the producer is incentivized to improve the performance of later stages is still a challenge. This paper argues for placing the producer at the centre of a new arrangement: by seeking to utilize the producer's knowledge of designing and the knowledge of volume production, through creation of platforms, while cooperating closely with other actors. The paper describes three case studies that have used such an approach to design and implement new food production systems. Based on 12 months of action research observations, 10 participating organizations from the cases were studied, and the implemented solutions assessed for environmental, economic and social performance. The results demonstrate a high level of sustainability benefit is achievable using platforms and partners to design product-service systems, while highlighting that changes to production arrangements are necessary but not sufficient to improve whole life-cycle environmental performance of product-service systems, and that producers need to cooperate closely with other actors to achieve the claimed benefits.

Cold-gas chemical vapor deposition to identify the key precursor for rapidly growing vertically-aligned single-wall and few-wall carbon nanotubes from pyrolyzed ethanol

Vertically-aligned carbon nanotubes (VA-CNTs) were rapidly grown from ethanol and their chemistry has been studied using a "cold-gas" chemical vapor deposition (CVD) method. Ethanol vapor was preheated in a furnace, cooled down and then flowed over cobalt catalysts upon ribbon-shaped substrates at 800 °C, while keeping the gas unheated. CNTs were obtained from ethanol on a sub-micrometer scale without preheating, but on a millimeter scale with preheating at 1000 °C. Acetylene was predicted to be the direct precursor by gas chromatography and gas-phase kinetic simulation, and actually led to millimeter-tall VA-CNTs without preheating when fed with hydrogen and water. There was, however a difference in CNT structure, i.e. mainly few-wall tubes from pyrolyzed ethanol and mainly single-wall tubes for unheated acetylene, and the by-products from ethanol pyrolysis possibly caused this difference. The "cold-gas" CVD, in which the gas-phase and catalytic reactions are separately controlled, allowed us to further understand CNT growth. © 2012 Elsevier Ltd. All rights reserved.

Exploring key sustainable development themes through learning activities

The Masters programme in Engineering for Sustainable Development at Cambridge University explores a number of key themes, including dealing with: complexity, uncertainty, change, other disciplines, people, environmental limits, whole life costs, and trade-offs. This paper examines how these concepts are introduced and analyses the range of exercises and assignments which are designed to encourage students to test their own assumptions and abilities to develop competencies in these areas. Student performance against these tasks is discussed and student feedback is also presented, with a focus on how their awareness of the themes are met through a range of activities.

Exploring key sustainable development themes through learning activities

Purpose: The paper examines how a number of key themes are introduced in the Masters programme in Engineering for Sustainable Development at Cambridge University through student centred activities. These themes include dealing with complexity, uncertainty, change, other disciplines, people, environmental limits, whole life costs, and trade-offs. Design/methodology/approach: The range of exercises and assignments designed to encourage students to test their own assumptions and abilities to develop competencies in these areas are analysed by mapping the key themes onto the formal activities which all students undertake throughout the core MPhil programme. The paper reviews the range of these activities that are designed to help support the formal delivery of the taught programme. These include residential field courses, role plays, change challenges, games, systems thinking, multi criteria decision making, awareness of literature from other disciplines and consultancy projects. An axial coding approach to the analysis of routine feedback questionnaires drawn from recent years has been used to identify how student’s own awareness develops. Also results of two surveys are presented which tests the students’ perceptions about whether or not the course is providing learning environments to develop awareness and skills in these areas. Findings: Students generally perform well against these tasks with a significant feature being the mutual support they give to each other in their learning. The paper concludes that for students from an engineering background it is an holistic approach to delivering a new way of thinking through a combination of lectures, class activities, assignments, interactions between class members, and access to material elsewhere in the University that enables participants to develop their skills in each of the key themes. Originality /value: The paper provides a reflection on different pedagogical approaches to exploring key sustainable themes and reports students own perceptions of the value of these kinds of activities. Experiences are shared of running a range of diverse learning activities within a professional practice Masters programme.

Electronic and magnetic properties of Ti(2)O(3), Cr(2)O(3), and Fe(2)O(3) calculated by the screened exchange hybrid density functional.

The electronic and magnetic properties of the transition metal sesqui-oxides Cr(2)O(3), Ti(2)O(3), and Fe(2)O(3) have been calculated using the screened exchange (sX) hybrid density functional. This functional is found to give a band structure, bandgap, and magnetic moment in better agreement with experiment than the local density approximation (LDA) or the LDA+U methods. Ti(2)O(3) is found to be a spin-paired insulator with a bandgap of 0.22 eV in the Ti d orbitals. Cr(2)O(3) in its anti-ferromagnetic phase is an intermediate charge transfer Mott-Hubbard insulator with an indirect bandgap of 3.31 eV. Fe(2)O(3), with anti-ferromagnetic order, is found to be a wide bandgap charge transfer semiconductor with a 2.41 eV gap. Interestingly sX outperforms the HSE functional for the bandgaps of these oxides.

Optimized selection of key frames for monocular videogrammetric surveying of civil infrastructure

Videogrammetry is an inexpensive and easy-to-use technology for spatial 3D scene recovery. When applied to large scale civil infrastructure scenes, only a small percentage of the collected video frames are required to achieve robust results. However, choosing the right frames requires careful consideration. Videotaping a built infrastructure scene results in large video files filled with blurry, noisy, or redundant frames. This is due to frame rate to camera speed ratios that are often higher than necessary; camera and lens imperfections and limitations that result in imaging noise; and occasional jerky motions of the camera that result in motion blur; all of which can significantly affect the performance of the videogrammetric pipeline. To tackle these issues, this paper proposes a novel method for automating the selection of an optimized number of informative, high quality frames. According to this method, as the first step, blurred frames are removed using the thresholds determined based on a minimum level of frame quality required to obtain robust results. Then, an optimum number of key frames are selected from the remaining frames using the selection criteria devised by the authors. Experimental results show that the proposed method outperforms existing methods in terms of improved 3D reconstruction results, while maintaining the optimum number of extracted frames needed to generate high quality 3D point clouds.© 2012 Elsevier Ltd. All rights reserved.

Getting to zero: evidence-based healthcare risk management is key.

In this article we call for a new approach to patient safety improvement, one based on the emerging field of evidence-based healthcare risk management (EBHRM). We explore EBHRM in the broader context of the evidence-based healthcare movement, assess the benefits and challenges that might arise in adopting an evidence-based approach, and make recommendations for meeting those challenges and realizing the benefits of a more scientific approach.

Calculation of point defects in rutile TiO 2 by the screened-exchange hybrid functional

The formation energies of the oxygen vacancy and titanium interstitial in rutile TiO 2 were calculated by the screened-exchange (sX) hybrid density functional method, which gives a band gap of 3.1 eV, close to the experimental value. The oxygen vacancy gives rise to a gap state lying 0.7 eV below the conduction band edge, whose charge density is localized around the two of three Ti atoms next to the vacancy. The Ti interstitial (Ti int) generates four defect states in the gap, whose unpaired electrons lie on the interstitial and the adjacent Ti 3d orbitals. The formation energy for the neutral oxygen vacancy is 1.9 eV for the O-poor chemical potential. The neutral Ti interstitial has a lower formation energy than the O vacancy under O-poor conditions. This indicates that both the O vacancy and Ti int are relevant for oxygen deficiency in rutile TiO 2 but the O vacancy will dominate under O-rich conditions. This resolves questions about defect localization and defect predominance in the literature. © 2012 American Physical Society.