Managing the Release of Emerging Agricultural Contaminants into the Environment

Recently there has been an increased interest regarding the environmental fate of veterinary medicines, however it is apparent that variability and knowledge gaps exist within the literature. The presented doctoral thesis employed novel, practical, and thorough experimental and analytical techniques to bridge these knowledge gaps but also to contribute towards a more robust and harmonised risk assessment. Reported veterinary medicine half-lives in animal manures are highly variable, this indicates that current exposure assessments are inaccurate, consequently predicted soil concentrations maybe under or overestimated. Manure properties are highly heterogenic and the current guidance permits the use of just one manure per animal type. Therefore, an experiment was designed to investigate whether commonly reported pig slurry pH’s and anaerobic redox potentials are contributing towards variable degradation rates. The results demonstrate these parameters to have a significant and compound specific effect on degradation rates. Therefore, to conduct accurate and realistic environmental fate assessments manure degradation studies should encompass numerous manures with differing properties. A semi-field experiment which evaluated the transfer of veterinary medicines under varying application techniques was conducted where eight veterinary medicines were identified to be transported to receiving waters. Incorporating slurries into soils and injection were identified to substantially reduce the transport of veterinary medicines over that of broadcast. A year-long field monitoring study was conducted to evaluate the fate of veterinary medicines at the farm scale and validate the modelling suite FOCUS_PEARL. Antibiotics recently utilized at the farm were detected in slurries, soils, and groundwaters. Antibiotics were observed to persist within groundwaters throughout the study, however, there was little compelling evidence to link this to their presence in slurries or soils. Moreover, the modelled predictions were observed to surpass that of the concentrations detected in groundwater

Interdisciplinarity in the Age of the Triple Helix: a Film Practitioner's Perspective

This integrative chapter contextualises my research including articles I have published as well as one of the creative artefacts developed from it, the feature film The Knife That Killed Me. I review my work considering the ways in which technology, industry methods and academic practice have evolved as well as how attitudes to interdisciplinarity have changed, linking these to Etzkowitz and Leydesdorff’s ‘Triple Helix’ model (1995). I explore my own experiences and observations of opportunities and challenges that have been posed by the intersection of different stakeholder needs and expectations, both from industry and academic perspectives, and argue that my work provides novel examples of the applicability of the ‘Triple Helix’ to the creative industries. The chapter concludes with a reflection on the evolution and direction of my work, the relevance of the ‘Triple Helix’ to creative practice, and ways in which this relationship could be investigated further

The Prose Storyboard Language: A Tool for Annotating and Directing Movies: (Version 2.0, Revised and Illustrated Edition)

International audienceThe prose storyboard language is a formal language for describing movies shot by shot, where each shot is described with a unique sentence. The language uses a simple syntax and limited vocabulary borrowed from working practices in traditional movie-making and is intended to be readable both by machines and humans. The language has been designed over the last ten years to serve as a high-level user interface for intelligent cinematography and editing systems. In this new paper, we present the latest evolution of the language, and the results of an extensive annotation exercise showing the benefits of the language in the task of annotating the sophisticated cinematography and film editing of classic movies

Spatiotemporal distribution of the anti-diabetic drug, metformin, in the lower Columbia River and its effect on phytoplankton growth

Water quality impacts both human and ecosystem health. Many pharmaceuticals and personal care products are considered contaminants of emerging concern (CEC) due to their bioactive properties. Among these, metformin—the most commonly prescribed drug for treatment of type 2 diabetes—has been reported at high concentrations (μg L⁻¹) in stream, lake, and estuary surface waters in the United States. However, a propensity for broad-scale CEC surveys has prevented seasonal and spatial monitoring of metformin in river systems. Moreover, the effect of metformin in river food webs remains poorly explored, despite its known action on conserved eukaryotic enzymes (AMPK/SnRK1/SNF1). This project comprised the first spatiotemporal characterization of metformin in a high-discharge river system and examined the effects of metformin on aquatic primary producers. Monthly water samples were taken at eight year-round sites and five additional summer-sites in the lower Columbia River from October 2016-September 2017. Metformin and its breakdown product, guanylurea, were determined from water samples using direct injection with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Laboratory toxicity assays using PAM fluorometry and environmentally or sewage relevant doses (50-500 μg L⁻¹) probed for effects of metformin on photosynthetic efficiency in green algae (Chlorella vulgaris) and diatom (Thalassiosira weissflogii) cultures. Metformin and guanylurea were successfully detected and quantified in the lower Columbia River (METAVG = 67.4 ng L⁻¹, GUANAVG = 32.6 ng L⁻¹). High variation in metformin concentrations was only partially explained by seasonal river discharge and riverine sources; but possible sorption effects suggested additional physicochemical influence. Metformin effects on algae depended on exposure time, dose, and species, with reduced photosynthetic efficiency of C. vulgaris cultures within 24 h of high dose exposure (500 μg L⁻¹), and within 72 h of sewage effluent-equivalent exposure (50 μg L⁻¹). Overall, these results are consistent with the expected behavior of a polar basic cation species in a high-flow river system and a SnRK1-activator in algae. This study illustrates the importance of investigating individual CECs in water systems in order to elucidate fine-scale processes governing distributions, behavior, and, ultimately, environmental risk

Computational Multimedia for Video Self Modeling

Video self modeling (VSM) is a behavioral intervention technique in which a learner models a target behavior by watching a video of oneself. This is the idea behind the psychological theory of self-efficacy - you can learn or model to perform certain tasks because you see yourself doing it, which provides the most ideal form of behavior modeling. The effectiveness of VSM has been demonstrated for many different types of disabilities and behavioral problems ranging from stuttering, inappropriate social behaviors, autism, selective mutism to sports training. However, there is an inherent difficulty associated with the production of VSM material. Prolonged and persistent video recording is required to capture the rare, if not existed at all, snippets that can be used to string together in forming novel video sequences of the target skill. To solve this problem, in this dissertation, we use computational multimedia techniques to facilitate the creation of synthetic visual content for self-modeling that can be used by a learner and his/her therapist with a minimum amount of training data. There are three major technical contributions in my research. First, I developed an Adaptive Video Re-sampling algorithm to synthesize realistic lip-synchronized video with minimal motion jitter. Second, to denoise and complete the depth map captured by structure-light sensing systems, I introduced a layer based probabilistic model to account for various types of uncertainties in the depth measurement. Third, I developed a simple and robust bundle-adjustment based framework for calibrating a network of multiple wide baseline RGB and depth cameras

Videos in Context for Telecommunication and Spatial Browsing

The research presented in this thesis explores the use of videos embedded in panoramic imagery to transmit spatial and temporal information describing remote environments and their dynamics. Virtual environments (VEs) through which users can explore remote locations are rapidly emerging as a popular medium of presence and remote collaboration. However, capturing visual representation of locations to be used in VEs is usually a tedious process that requires either manual modelling of environments or the employment of specific hardware. Capturing environment dynamics is not straightforward either, and it is usually performed through specific tracking hardware. Similarly, browsing large unstructured video-collections with available tools is difficult, as the abundance of spatial and temporal information makes them hard to comprehend. At the same time, on a spectrum between 3D VEs and 2D images, panoramas lie in between, as they offer the same 2D images accessibility while preserving 3D virtual environments surrounding representation. For this reason, panoramas are an attractive basis for videoconferencing and browsing tools as they can relate several videos temporally and spatially. This research explores methods to acquire, fuse, render and stream data coming from heterogeneous cameras, with the help of panoramic imagery. Three distinct but interrelated questions are addressed. First, the thesis considers how spatially localised video can be used to increase the spatial information transmitted during video mediated communication, and if this improves quality of communication. Second, the research asks whether videos in panoramic context can be used to convey spatial and temporal information of a remote place and the dynamics within, and if this improves users' performance in tasks that require spatio-temporal thinking. Finally, the thesis considers whether there is an impact of display type on reasoning about events within videos in panoramic context. These research questions were investigated over three experiments, covering scenarios common to computer-supported cooperative work and video browsing. To support the investigation, two distinct video+context systems were developed. The first telecommunication experiment compared our videos in context interface with fully-panoramic video and conventional webcam video conferencing in an object placement scenario. The second experiment investigated the impact of videos in panoramic context on quality of spatio-temporal thinking during localization tasks. To support the experiment, a novel interface to video-collection in panoramic context was developed and compared with common video-browsing tools. The final experimental study investigated the impact of display type on reasoning about events. The study explored three adaptations of our video-collection interface to three display types. The overall conclusion is that videos in panoramic context offer a valid solution to spatio-temporal exploration of remote locations. Our approach presents a richer visual representation in terms of space and time than standard tools, showing that providing panoramic contexts to video collections makes spatio-temporal tasks easier. To this end, videos in context are suitable alternative to more difficult, and often expensive solutions. These findings are beneficial to many applications, including teleconferencing, virtual tourism and remote assistance

EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2013. Scientific Opinion on the public health hazards to be covered by inspection of meat (bovine animals).

A risk ranking process identified Salmonella spp. and pathogenic verocytotoxin-producing Escherichia coli (VTEC) as current high-priority biological hazards for meat inspection of bovine animals. As these hazards are not detected by traditional meat inspection, a meat safety assurance system for the farm-to-chilled carcass continuum using a risk-based approach was proposed. Key elements of the system are risk-categorisation of slaughter animals for high-priority biological hazards based on improved food chain information, as well as risk-categorisation of slaughterhouses according to their capability to control those hazards. Omission of palpation and incision during post-mortem inspection for animals subjected to routine slaughter may decrease spreading and cross-contamination with the high-priority biological hazards. For chemical hazards, dioxins and dioxin-like polychlorinated biphenyls were ranked as being of high potential concern; all other substances were ranked as of medium or lower concern. Monitoring programmes for chemical hazards should be more flexible and based on the risk of occurrence, taking into account the completeness and quality of the food chain information supplied and the ranking of chemical substances, which should be regularly updated to include new hazards. Control programmes across the food chain, national residue control programmes, feed control and monitoring of environmental contaminants should be better integrated. Meat inspection is a valuable tool for surveillance and monitoring of animal health and welfare conditions. Omission of palpation and incision would reduce detection effectiveness for bovine tuberculosis and would have a negative impact on the overall surveillance system especially in officially tuberculosis free countries. The detection effectiveness for bovine cysticercosis, already low with the current meat inspection system, would result in a further decrease, if palpation and incision are removed. Extended use of food chain information could compensate for some, but not all, the information on animal health and welfare lost if only visual post-mortem inspection is applied

Avaliação dos efeitos de químicos usados na aquacultura

Doutoramento em BiologiaAquaculture provides food and income for millions of families worldwide being an activity with a high growth rate and with a strong potential for further expansion. Both producers and consumers are interested in a sustainable model of aquaculture development covering social, economic and environmental aspects. Such model implies to cope with the environmental impacts generated by aquacultures. The main objective of this work was to evaluate the use of chemicals applied in aquaculture farms and their harmful effects to aquatic organisms. Since more than 80% of global production of aquatic organisms is concentrated in Southwest Asia, special attention was given to the aquaculture in this region, particularly Thailand. Three different types of aquaculture scenarios were studied: shrimp farms and tilapia farms in cages and in earth ponds. Surveys and monitoring campaigns were conducted in several farms and the fate, use and application patterns of chemicals were identified. In cage farms the results indicated overuse/misuse of antibiotics, in shrimp farms the major group of chemicals used were disinfectants whereas in earth pond farms 1,7α-methyltestosterone (MT) was the most used. The results from the monitoring campaigns showed that the excessive use of chemicals was correlated to contamination of the surrounding environment namely with the antibiotics oxytetracycline (OTC) and enrofloxacin (ENR) in the cage farms, and with MT in the earth pond farms. In the laboratory, ecotoxicity assays were performed with antibiotics, disinfectants and pesticides using organisms belonging to different trophic levels. The disinfectants benzalkonium chloride (BKC), chlorhexidine gluconate (ChD) and glutaraldehyde (GA) were tested. BKC and ChD demonstrated to be very toxic to primary and secondary consumers. Moreover, an approach based on the species sensitivity distributions (SSD) was used to estimate the hazardous concentrations for 5 and 50 % of the species after BKC and GA exposure highlighting the sensitivity of primary producers to BKC exposure (HC5 = 10.8 μg/l). In the case of GA, different trophic levels showed similar sensitivities and a general HC5 = 300 μg/l was obtained. Additionally, a probabilistic environmental risk assessment was performed indicating a PAF (potentially affected fraction) of species > 5% for adverse effects of BKC in effluents and surface water. Concerning pesticides, both trichlorfon (TCF) and ivermectin (IVM) were studied. TCF showed to be extremely toxic to daphnids (48h- LC50 = 0.29 μg/l) and affected the acetilcolinesterase activity in D. magna and D rerio. IVM showed to be acutely toxic to D. rerio life stages (96h-LC50 = 18.5 μg/l for juveniles) and affected their development and biomarkers. In chronic exposures, IVM led to changes in the behaviour and growth of D. rerio juveniles (21d-LOEC 5% em efluentes e águas superficiais. Os pesticidas estudados foram o trichlorfon (TCF) e a ivermectina (IVM). O TCF foi extremamente tóxico para dafnídeos (48h-LC50 = 0,29 μg/l) e afectou também a actividade de acetilcolinesterase em D. magna e D. rerio. A IVM foi tóxica para adultos, juvenis e embriões de D. rerio (96h- CL50 = 18,5 μg/l para os juvenis) afectando o seu desenvolvimento e actividade de biomarcadores. Em exposições crónicas, IVM causou alterações no comportamento e crescimento em D. rerio juvenis (21d-LOEC <0,25 μg/l). Os antibióticos amoxicilina e OTC apresentam baixa toxidade para os organismos aquáticos, mas ambos induziram enzimas relacionadas estresse oxidativo em adultos e embriões de D. rerio. Em geral, a maioria dos químicos testados apresentaram toxicidade para algum grupo de organismo da cadeia trófica ou tiveram efeito a nível de parâmetros sub-letais, sendo portanto recomendados estudos de exposição crónica para que se possa refinar a avaliação de risco ambiental destes compostos. Os efeitos letais e sub-letais observados nos organismos não-alvo sugerem que pode haver uma perda da biodiversidade nos ecossistemas aquáticos, e assim, comprometer os serviços prestados pelos ecossistemas num futuro próximo. Sendo o sucesso da aquacultura dependente directo destes serviços (por exemplo, água de alta qualidade), há uma necessidade urgente de medidas de controlo/educação, tanto no uso de produtos químicos na aquacultura e monitoramento/mitigação dos impactos negativos destes nos ecossistemas naturais

Prevalence and antibiotic susceptibility of Listeria monocytogenes isolated from broiler chickens within Durban, South Africa.

Master of Science in Life Sciences. University of KwaZulu-Natal, Durban, 2016.Abstract available in PDF file