Analysis of behavioral changes of zebrafish (Danio rerio) in response to formaldehyde using Self-organizing map and a hidden Markov model

Two computational methods were applied to classification of movement patterns of zebrafish (Danio rerio) to elucidate Markov processes in behavioral changes before and after treatment of formaldehyde (0.1 mg/L) in semi-natural conditions. The complex data of the movement tracks were initially classified by the Self-organizing map (SOM) to present different behavioral states of test individuals. Transition probabilities between behavioral states were further evaluated to fit Markov processes by using the hidden Markov model (HMM). Emission transition probability was also obtained from the observed variables (i.e., speed) for training with the HMM. Experimental transition and emission probability matrices were successfully estimated with the HMM for recognizing sequences of behavioral states with accuracy rates in acceptable ranges at central and boundary zones before (77.3-81.2%) and after (70.1-76.5%) treatment. A heuristic algorithm and a Markov model were efficiently combined to analyze movement patterns and could be a means of in situ behavioral monitoring tool.     

Breaking barriers for a bio-based economy: Interactive reflection on monitoring water quality

In a transition to a bio-based economy new ways of monitoring waste-streams and water quality can then contribute to sustainable production processes. As niche innovation, new ways of monitoring face systemic barriers. The present article examines how barriers to change manifest in discursive practices with differing normative attachments and implications. A frame analysis revealed two competing frames: (1) the dominant ‘norm water’ frame in which thresholds of chemical compounds are used to set policy targets; and (2) the contesting ‘living water’ frame, which entails innovative continuous monitoring tools that take into account the ecological effects of chemical compounds. We introduce the concept of interactive reflectivity, as a discursive tool, to collaboratively visualize, scrutinize and overcome discursive barriers to innovations. The stakeholder dialogue shows how systemic barriers are uttered discursively in niches – or other forms of responsible research and innovation – and may hinder change even at the niche-level.     

The transition in Dutch water management

Over the past decades, the Dutch people have been confronted with severe water-related problems, which are the result of an unsustainable water system, arising from human interventions in the physical infrastructure of the water system and the water management style. The claims of housing, industry, infrastructure and agriculture have resulted in increasing pressure on the water system. The continuous subsidence of soil and climate change has put pressure on the land. Hence, the nature and magnitude of water-related problems have changed. Longitudinal research of relevant national policy documents reveals that the water management regime has changed its water management style over the past 30 years from a technocratic scientific style towards an integral and participatory style. We have investigated if the historical development in Dutch Water management can be characterized as a transition. Based on longitudinal research through an integrated systems analysis, document research and expert interviews, we have reconstructed the historical narrative by using the transition concepts of multi-level and multi-phase. This research indicates that the shift in Dutch Water management can be characterized as a transition. This transition is currently in the take-off stage and near the acceleration stage. This is a crucial stage as long as the considerable gap between the strategic macro-vision and the practical implementation at the micro-level remains. As long as these levels are not compatible (modulation), the transition will not be completed successfully. Transition management as multi-level governance model should therefore be adopted to facilitate the modulation.     

氯氟烃及其替代物

近年来,臭氧衰竭比原先预料的更严重,对人类健康和环境构成了严重威胁。“蒙特利尔议定书”和“大气清洁法案”要求2000年要完全清除致臭氧衰竭物质——氯氟烃(CFCs)的生产和使用。目前,世界各地积极开发CFCs的替代物,以加速转换。虽然已开发的氧氯氟烃(HCFCs)、氢氟烃(HFCs)等替代物与CFCs相比还有一定缺点,但最终一定会实现替代转换。     

Insights into reactive oxygen species formation induced by water-soluble organic compounds and transition metals using spectroscopic method

Ambient particulate matter (PM) can cause adverse health effects via their ability to produce Reactive Oxygen Species (ROS). Water-Soluble Organic Compounds (WSOCs), a complex mixture of organic compounds which usually coexist with Transition Metals (TMs) in PM, have been found to contribute to ROS formation. However, the interaction between WSOCs and TMs and its effect on ROS generation are still unknown. In this study, we examined the ROS concentrations of V, Zn, Suwannee River Fulvic Acid (SRFA), Suwannee River Humic Acid (SRHA) and the mixtures of V/Zn and SRFA/SRHA by using a cell-free 2′,7′-Dichlorodihydrofluorescein (DCFH) assay. The results showed that V or Zn synergistically promoted ROS generated by SRFA, but had an antagonistic effect on ROS generated by SRHA. Fluorescence quenching experiments indicated that V and Zn were more prone to form stable complexes with aromatic humic acid-like component (C1) and fulvic acid-like component (C3) in SRFA and SRHA. Results suggested that the underlying mechanism involving the fulvic acid-like component in SRFA more tending to complex with TMs to facilitate ROS generation through π electron transfer. Our work showed that the complexing ability and complexing stability of atmospheric PM organics with metals could significantly affect ROS generation. It is recommended that the research deploying multiple analytical methods to quantify the impact of PM components on public health and environment is needed in the future.     

Assessing diversity and inclusivity within the Transition movement: an urban case study

The Transition movement has experienced remarkable growth in its first decade, yet there remains considerable doubt about its ability to appeal to a diverse audience. To date, few studies have explicitly examined diversity of participation in the movement. Addressing this gap in the literature, a case study is presented of Transition Town Tooting (TTT). Results from a mixed methods approach comprising semi-structured interviews, participant observation, and a quantitative survey indicate that the demographic profiles of TTT participants do not represent the diversity of the Tooting population. This disparity is exacerbated by TTT’s ‘passive’ approach to inclusivity within the core group. Reflecting upon the implications for Transition’s goal of local resilience, it is suggested that, particularly within dense urban communities, initiatives may have more potential for engaging diverse voices through a local ‘brokering’ role between various subcommunities.     

Electro-Fenton degradation of cationic red X-GRL using an activated carbon fiber cathode

We reported the study of the degradation of the azo dye cationic red X-GRL by the electro-Fenton process using an activated carbon fiber cathode. The electrogeneration of hydrogen peroxide in solution using different material cathodes fed with air was investigated, and the results revealed that the activated carbon fiber cathode was more effective compared to the graphite cathode. The decolorization and mineralization of cationic red X-GRL were also determined. The effect of the operating parameters, such as the initial Fe²⁺ concentration, temperature and initial dye concentration, was investigated. The optimum Fe²⁺ catalyst concentration values for the degradation of cationic red X-GRL was found to be 5 mM. The rate of decolorization and mineralization of dye could be accelerated by increasing the temperature. In addition, the decolorization and total organic carbon (TOC) removal efficiency decreased with the increasing initial dye concentration, while the TOC removal increased. Two different transition metal ions (Cu²⁺ and Mn²⁺) were applied as substitutes for ferrous sulfate for evaluating catalytic effect. The results indicated that Cu²⁺ and Mn²⁺ were more effective than Fe²⁺ in catalyzing the degradation of the dye.     

Sustainable growth: Compatibility between a plausible growth criterion and the initial state

There is a large body of research devoted to understanding sustainable growth in resource-based economies. Some of this research cannot be applied to real economies directly because the initial states of real economies do not match the initial states assumed in the models. Using a model of theDasgupta–Heal–Solow–Stiglitz variety the paper shows that inconsistency between assumed and actual initial states can lead to a less desirable, in particular, a Pareto inferior path of consumption per capita. The paper also presents a methodology for constructing transition paths from an imperfect initial state to an initial state compatible with the standard steady state consumption path.     

The emergence of the transition movement in Canada: success and impact through the eyes of initiative leaders

ABSTRACT

Originating in the UK in 2006, the Transition movement is oriented to local grassroots citizen-led efforts that prepare for and support a societal energy transition to a low-carbon future in response to climate change, peak oil, ecological degradation, and economic instability. Overlapping significantly with relocalization, degrowth/slow growth, local food, and related movements, and based on permaculture principles and a distributed network model, it embraces the opportunity to turn crisis into an opportunity to build more resilient, convivial, and vibrant local communities, declaring that “if it’s not fun, it’s not sustainable”. The Transition approach has spread rapidly around the world, including initiatives in over 100 communities and cities in Canada. This paper reports on the methods and results of a Canadian community-based research study aimed at understanding how and where the movement has taken root across the country, what Transition practice looks like, challenges and opportunities encountered, and lessons learned that could be applied within the movement and by others interested in the role of citizen-led initiatives for sustainability transition. Utilising a practice theory lens, drawing on an extensive web-scan of the movement’s online presence, a survey and interviews with initiative (co)founders, an e-survey of Transition members/participants, regional “structured story-dialogue” workshops, and key informant interviews, and informed by input from a Movement Advisory Group, we describe the research process and explore what success and impact mean to those most active in the movement.     

Towards phosphorus sustainability in North America: A model for transformational change

Global food production and security rely heavily on finite reserves of newly mined phosphate for fertilizers. However, systemic inefficiencies result in the deposition in aquatic ecosystems of much of the phosphorus mined for food production causing costly eutrophication problems that damage aquatic ecosystems and human health. The Sustainable Phosphorus Alliance (SPA, formerly named North American Partnership for Phosphorus Sustainability) was created to implement sustainable phosphorus solutions through active engagement of stakeholders in both the private and public sectors. This paper describes a conceptual model of transformative change to a sustainable phosphorus system for the North American region. The model emerged from discussions at a series of formal and informal meetings held in conjunction with a ‘Future of Phosphorus’ event (National Science Foundation’s Phosphorus Sustainability Research Coordination Network) and an inaugural SPA Board meeting. Model development drew on the multi-level perspective of socio-technical transitions to develop a series of pathways to a transformed phosphorus system. The uses of the model and transition pathways are discussed in terms of their potential to form an important first step towards the development of a regional vision for improved phosphorus sustainability. The process provides an example of how research in sustainability science can contribute to action on environmental improvement.